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Sample records for high accuracy reference

  1. High Accuracy Reference Network (HARN), Points generated from coordinates supplied by NGS, Published in 1993, MARIS.

    Data.gov (United States)

    NSGIC GIS Inventory (aka Ramona) — This High Accuracy Reference Network (HARN) dataset, was produced all or in part from Field Survey/GPS information as of 1993. It is described as 'Points generated...

  2. Data supporting the high-accuracy haplotype imputation using unphased genotype data as the references

    Directory of Open Access Journals (Sweden)

    Wenzhi Li

    2016-09-01

    Full Text Available The data presented in this article is related to the research article entitled “High-accuracy haplotype imputation using unphased genotype data as the references” which reports the unphased genotype data can be used as reference for haplotyping imputation [1]. This article reports different implementation generation pipeline, the results of performance comparison between different implementations (A, B, and C and between HiFi and three major imputation software tools. Our data showed that the performances of these three implementations are similar on accuracy, in which the accuracy of implementation-B is slightly but consistently higher than A and C. HiFi performed better on haplotype imputation accuracy and three other software performed slightly better on genotype imputation accuracy. These data may provide a strategy for choosing optimal phasing pipeline and software for different studies.

  3. High accuracy Primary Reference gas Mixtures for high-impact greenhouse gases

    Science.gov (United States)

    Nieuwenkamp, Gerard; Zalewska, Ewelina; Pearce-Hill, Ruth; Brewer, Paul; Resner, Kate; Mace, Tatiana; Tarhan, Tanil; Zellweger, Christophe; Mohn, Joachim

    2017-04-01

    Climate change, due to increased man-made emissions of greenhouse gases, poses one of the greatest risks to society worldwide. High-impact greenhouse gases (CO2, CH4 and N2O) and indirect drivers for global warming (e.g. CO) are measured by the global monitoring stations for greenhouse gases, operated and organized by the World Meteorological Organization (WMO). Reference gases for the calibration of analyzers have to meet very challenging low level of measurement uncertainty to comply with the Data Quality Objectives (DQOs) set by the WMO. Within the framework of the European Metrology Research Programme (EMRP), a project to improve the metrology for high-impact greenhouse gases was granted (HIGHGAS, June 2014-May 2017). As a result of the HIGHGAS project, primary reference gas mixtures in cylinders for ambient levels of CO2, CH4, N2O and CO in air have been prepared with unprecedented low uncertainties, typically 3-10 times lower than usually previously achieved by the NMIs. To accomplish these low uncertainties in the reference standards, a number of preparation and analysis steps have been studied and improved. The purity analysis of the parent gases had to be performed with lower detection limits than previously achievable. E.g., to achieve an uncertainty of 2•10-9 mol/mol (absolute) on the amount fraction for N2O, the detection limit for the N2O analysis in the parent gases has to be in the sub nmol/mol domain. Results of an OPO-CRDS analyzer set-up in the 5µm wavelength domain, with a 200•10-12 mol/mol detection limit for N2O, will be presented. The adsorption effects of greenhouse gas components at cylinder surfaces are critical, and have been studied for different cylinder passivation techniques. Results of a two-year stability study will be presented. The fit-for-purpose of the reference materials was studied for possible variation on isotopic composition between the reference material and the sample. Measurement results for a suit of CO2 in air

  4. High Accuracy Reference Network (HARN), Published in 2000, 1:600 (1in=50ft) scale, Brown County, WI.

    Data.gov (United States)

    NSGIC GIS Inventory (aka Ramona) — This High Accuracy Reference Network (HARN) dataset, published at 1:600 (1in=50ft) scale, was produced all or in part from Field Survey/GPS information as of 2000....

  5. High-Accuracy HLA Type Inference from Whole-Genome Sequencing Data Using Population Reference Graphs.

    Directory of Open Access Journals (Sweden)

    Alexander T Dilthey

    2016-10-01

    Full Text Available Genetic variation at the Human Leucocyte Antigen (HLA genes is associated with many autoimmune and infectious disease phenotypes, is an important element of the immunological distinction between self and non-self, and shapes immune epitope repertoires. Determining the allelic state of the HLA genes (HLA typing as a by-product of standard whole-genome sequencing data would therefore be highly desirable and enable the immunogenetic characterization of samples in currently ongoing population sequencing projects. Extensive hyperpolymorphism and sequence similarity between the HLA genes, however, pose problems for accurate read mapping and make HLA type inference from whole-genome sequencing data a challenging problem. We describe how to address these challenges in a Population Reference Graph (PRG framework. First, we construct a PRG for 46 (mostly HLA genes and pseudogenes, their genomic context and their characterized sequence variants, integrating a database of over 10,000 known allele sequences. Second, we present a sequence-to-PRG paired-end read mapping algorithm that enables accurate read mapping for the HLA genes. Third, we infer the most likely pair of underlying alleles at G group resolution from the IMGT/HLA database at each locus, employing a simple likelihood framework. We show that HLA*PRG, our algorithm, outperforms existing methods by a wide margin. We evaluate HLA*PRG on six classical class I and class II HLA genes (HLA-A, -B, -C, -DQA1, -DQB1, -DRB1 and on a set of 14 samples (3 samples with 2 x 100bp, 11 samples with 2 x 250bp Illumina HiSeq data. Of 158 alleles tested, we correctly infer 157 alleles (99.4%. We also identify and re-type two erroneous alleles in the original validation data. We conclude that HLA*PRG for the first time achieves accuracies comparable to gold-standard reference methods from standard whole-genome sequencing data, though high computational demands (currently ~30-250 CPU hours per sample remain a

  6. High-Accuracy HLA Type Inference from Whole-Genome Sequencing Data Using Population Reference Graphs.

    Science.gov (United States)

    Dilthey, Alexander T; Gourraud, Pierre-Antoine; Mentzer, Alexander J; Cereb, Nezih; Iqbal, Zamin; McVean, Gil

    2016-10-01

    Genetic variation at the Human Leucocyte Antigen (HLA) genes is associated with many autoimmune and infectious disease phenotypes, is an important element of the immunological distinction between self and non-self, and shapes immune epitope repertoires. Determining the allelic state of the HLA genes (HLA typing) as a by-product of standard whole-genome sequencing data would therefore be highly desirable and enable the immunogenetic characterization of samples in currently ongoing population sequencing projects. Extensive hyperpolymorphism and sequence similarity between the HLA genes, however, pose problems for accurate read mapping and make HLA type inference from whole-genome sequencing data a challenging problem. We describe how to address these challenges in a Population Reference Graph (PRG) framework. First, we construct a PRG for 46 (mostly HLA) genes and pseudogenes, their genomic context and their characterized sequence variants, integrating a database of over 10,000 known allele sequences. Second, we present a sequence-to-PRG paired-end read mapping algorithm that enables accurate read mapping for the HLA genes. Third, we infer the most likely pair of underlying alleles at G group resolution from the IMGT/HLA database at each locus, employing a simple likelihood framework. We show that HLA*PRG, our algorithm, outperforms existing methods by a wide margin. We evaluate HLA*PRG on six classical class I and class II HLA genes (HLA-A, -B, -C, -DQA1, -DQB1, -DRB1) and on a set of 14 samples (3 samples with 2 x 100bp, 11 samples with 2 x 250bp Illumina HiSeq data). Of 158 alleles tested, we correctly infer 157 alleles (99.4%). We also identify and re-type two erroneous alleles in the original validation data. We conclude that HLA*PRG for the first time achieves accuracies comparable to gold-standard reference methods from standard whole-genome sequencing data, though high computational demands (currently ~30-250 CPU hours per sample) remain a significant

  7. Radiometric inter-sensor cross-calibration uncertainty using a traceable high accuracy reference hyperspectral imager

    Science.gov (United States)

    Gorroño, Javier; Banks, Andrew C.; Fox, Nigel P.; Underwood, Craig

    2017-08-01

    Optical earth observation (EO) satellite sensors generally suffer from drifts and biases relative to their pre-launch calibration, caused by launch and/or time in the space environment. This places a severe limitation on the fundamental reliability and accuracy that can be assigned to satellite derived information, and is particularly critical for long time base studies for climate change and enabling interoperability and Analysis Ready Data. The proposed TRUTHS (Traceable Radiometry Underpinning Terrestrial and Helio-Studies) mission is explicitly designed to address this issue through re-calibrating itself directly to a primary standard of the international system of units (SI) in-orbit and then through the extension of this SI-traceability to other sensors through in-flight cross-calibration using a selection of Committee on Earth Observation Satellites (CEOS) recommended test sites. Where the characteristics of the sensor under test allows, this will result in a significant improvement in accuracy. This paper describes a set of tools, algorithms and methodologies that have been developed and used in order to estimate the radiometric uncertainty achievable for an indicative target sensor through in-flight cross-calibration using a well-calibrated hyperspectral SI-traceable reference sensor with observational characteristics such as TRUTHS. In this study, Multi-Spectral Imager (MSI) of Sentinel-2 and Landsat-8 Operational Land Imager (OLI) is evaluated as an example, however the analysis is readily translatable to larger-footprint sensors such as Sentinel-3 Ocean and Land Colour Instrument (OLCI) and Visible Infrared Imaging Radiometer Suite (VIIRS). This study considers the criticality of the instrumental and observational characteristics on pixel level reflectance factors, within a defined spatial region of interest (ROI) within the target site. It quantifies the main uncertainty contributors in the spectral, spatial, and temporal domains. The resultant tool

  8. High-accuracy reference standards for two-photon absorption in the 680-1050 nm wavelength range.

    Science.gov (United States)

    de Reguardati, Sophie; Pahapill, Juri; Mikhailov, Alexander; Stepanenko, Yuriy; Rebane, Aleksander

    2016-04-18

    Degenerate two-photon absorption (2PA) of a series of organic fluorophores is measured using femtosecond fluorescence excitation method in the wavelength range, λ2PA = 680-1050 nm, and ~100 MHz pulse repetition rate. The function of relative 2PA spectral shape is obtained with estimated accuracy 5%, and the absolute 2PA cross section is measured at selected wavelengths with the accuracy 8%. Significant improvement of the accuracy is achieved by means of rigorous evaluation of the quadratic dependence of the fluorescence signal on the incident photon flux in the whole wavelength range, by comparing results obtained from two independent experiments, as well as due to meticulous evaluation of critical experimental parameters, including the excitation spatial- and temporal pulse shape, laser power and sample geometry. Application of the reference standards in nonlinear transmittance measurements is discussed.

  9. Accuracy of References in Five Entomology Journals.

    Science.gov (United States)

    Kristof, Cynthia

    ln this paper, the bibliographical references in five core entomology journals are examined for citation accuracy in order to determine if the error rates are similar. Every reference printed in each journal's first issue of 1992 was examined, and these were compared to the original (cited) publications, if possible, in order to determine the…

  10. On combining reference data to improve imputation accuracy.

    Directory of Open Access Journals (Sweden)

    Jun Chen

    Full Text Available Genotype imputation is an important tool in human genetics studies, which uses reference sets with known genotypes and prior knowledge on linkage disequilibrium and recombination rates to infer un-typed alleles for human genetic variations at a low cost. The reference sets used by current imputation approaches are based on HapMap data, and/or based on recently available next-generation sequencing (NGS data such as data generated by the 1000 Genomes Project. However, with different coverage and call rates for different NGS data sets, how to integrate NGS data sets of different accuracy as well as previously available reference data as references in imputation is not an easy task and has not been systematically investigated. In this study, we performed a comprehensive assessment of three strategies on using NGS data and previously available reference data in genotype imputation for both simulated data and empirical data, in order to obtain guidelines for optimal reference set construction. Briefly, we considered three strategies: strategy 1 uses one NGS data as a reference; strategy 2 imputes samples by using multiple individual data sets of different accuracy as independent references and then combines the imputed samples with samples based on the high accuracy reference selected when overlapping occurs; and strategy 3 combines multiple available data sets as a single reference after imputing each other. We used three software (MACH, IMPUTE2 and BEAGLE for assessing the performances of these three strategies. Our results show that strategy 2 and strategy 3 have higher imputation accuracy than strategy 1. Particularly, strategy 2 is the best strategy across all the conditions that we have investigated, producing the best accuracy of imputation for rare variant. Our study is helpful in guiding application of imputation methods in next generation association analyses.

  11. Reference List Accuracy in Social Work Journals

    Science.gov (United States)

    Spivey, Christina A.; Wilks, Scott E.

    2004-01-01

    This exploratory study investigated the rate of citation errors in the reference lists of five social work journals. High error rates have been found in journals in fields such as medicine and psychology but have not yet been investigated in social work journals. A stratified, computer-generated random sample was selected (N = 500, 100 per…

  12. High-accuracy imputation for HLA class I and II genes based on high-resolution SNP data of population-specific references.

    Science.gov (United States)

    Khor, S-S; Yang, W; Kawashima, M; Kamitsuji, S; Zheng, X; Nishida, N; Sawai, H; Toyoda, H; Miyagawa, T; Honda, M; Kamatani, N; Tokunaga, K

    2015-12-01

    Statistical imputation of classical human leukocyte antigen (HLA) alleles is becoming an indispensable tool for fine-mappings of disease association signals from case-control genome-wide association studies. However, most currently available HLA imputation tools are based on European reference populations and are not suitable for direct application to non-European populations. Among the HLA imputation tools, The HIBAG R package is a flexible HLA imputation tool that is equipped with a wide range of population-based classifiers; moreover, HIBAG R enables individual researchers to build custom classifiers. Here, two data sets, each comprising data from healthy Japanese individuals of difference sample sizes, were used to build custom classifiers. HLA imputation accuracy in five HLA classes (HLA-A, HLA-B, HLA-DRB1, HLA-DQB1 and HLA-DPB1) increased from the 82.5-98.8% obtained with the original HIBAG references to 95.2-99.5% with our custom classifiers. A call threshold (CT) of 0.4 is recommended for our Japanese classifiers; in contrast, HIBAG references recommend a CT of 0.5. Finally, our classifiers could be used to identify the risk haplotypes for Japanese narcolepsy with cataplexy, HLA-DRB1*15:01 and HLA-DQB1*06:02, with 100% and 99.7% accuracy, respectively; therefore, these classifiers can be used to supplement the current lack of HLA genotyping data in widely available genome-wide association study data sets.

  13. High Accuracy Reference Network (HARN), We use the HARN that the State of WIsconsin Department of Transportation installed in 2005., Published in 2005, 1:600 (1in=50ft) scale, Lafayette County Land Records.

    Data.gov (United States)

    NSGIC GIS Inventory (aka Ramona) — This High Accuracy Reference Network (HARN) dataset, published at 1:600 (1in=50ft) scale, was produced all or in part from Field Survey/GPS information as of 2005....

  14. Spectral responsivity calibration of the reference radiation thermometer at KRISS by using a super-continuum laser-based high-accuracy monochromatic source

    Science.gov (United States)

    Yoo, Yong Shim; Kim, Gun Jung; Park, Seongchong; Lee, Dong-Hoon; Kim, Bong-Hak

    2016-12-01

    We report on the calibration of the relative spectral responsivity of the reference radiation thermometer, model LP4, which is used for the experimental realisation of the international temperature scale of 1990 above 960 °C at the Korea Research Institute of Standards and Science. The relative spectral responsivity of LP4 is measured by using a monochromatic source consisting of a super-continuum laser and a double-grating monochromator. By monitoring the wavelength of the output beam directly with a calibrated wavelength-meter, we achieved a high-accuracy measurement of spectral responsivity with a maximum wavelength error of less than 3 pm, a narrow spectral bandwidth of less than 0.4 nm, and a high dynamic range over 8 decades. We evaluated the contributions of various uncertainty components of the spectral responsivity measurement to the uncertainty of the temperature scale based on a practical estimation approach, which numerically calculates the maximal effects of the variations of each component. As a result, we evaluate the uncertainty contribution from the spectral responsivity measurement to the temperature scale to be less than 64 mK (k  =  1) in a range from 660 °C to 2749 °C for the LP4 with a filter at 650 nm.

  15. Accuracy of References in Ten Library Science Journals.

    Science.gov (United States)

    Pope, Nancy N.

    1992-01-01

    A study of 100 article citations from 11 library science journals showed only 45 article citations that were completely free of errors, while 11 had major errors--i.e., errors preventing or hindering location of the reference--and the remaining 44 had minor errors. Citation accuracy in library science journals appears similar to accuracy in other…

  16. Accuracy of references in Internet Journal of Medical Update

    Directory of Open Access Journals (Sweden)

    Prakash Adhikari

    2011-07-01

    Full Text Available This study was done to observe the accuracy of references in articles published in Internet Journal of Medical Update (IJMU. Sixty references were randomly selected from IJMU (Volume 5, Number 2, July 2010, Volume 4, Number 2, July 2009 and Volume 4, Number 1, January 2009. The instructions for authors of this journal were looked carefully. All the references were compared with the original for accuracy, using the following six elements: authors name; journal name as per Index Medicus; year; volume; and page numbers. References were considered incorrect if there was an error in any of these six elements. Statistical analysis was done by using frequency and percentage. Ten percent references in Internet Journal of Medical Update were inaccurate. Most common errors were author’s name and title of the article. Author’s names were found to be incorrect in 5.0% references while title of the article was found to be incorrect in 3.3%. Least common error was found in writing the journal name (either incorrect abbreviations or incorrect instructions or punctuation errors in (1.7%. Inaccuracies of references are also found in the Internet Journal of Medical Update. The majority of errors in IJMU are avoidable. So, the authors, editors and the reviewers have to check for any errors seriously before publication in the journal.

  17. Bias due to composite reference standards in diagnostic accuracy studies.

    Science.gov (United States)

    Schiller, Ian; van Smeden, Maarten; Hadgu, Alula; Libman, Michael; Reitsma, Johannes B; Dendukuri, Nandini

    2016-04-30

    Composite reference standards (CRSs) have been advocated in diagnostic accuracy studies in the absence of a perfect reference standard. The rationale is that combining results of multiple imperfect tests leads to a more accurate reference than any one test in isolation. Focusing on a CRS that classifies subjects as disease positive if at least one component test is positive, we derive algebraic expressions for sensitivity and specificity of this CRS, sensitivity and specificity of a new (index) test compared with this CRS, as well as the CRS-based prevalence. We use as a motivating example the problem of evaluating a new test for Chlamydia trachomatis, an asymptomatic disease for which no gold-standard test exists. As the number of component tests increases, sensitivity of this CRS increases at the expense specificity, unless all tests have perfect specificity. Therefore, such a CRS can lead to significantly biased accuracy estimates of the index test. The bias depends on disease prevalence and accuracy of the CRS. Further, conditional dependence between the CRS and index test can lead to over-estimation of index test accuracy estimates. This commonly-used CRS combines results from multiple imperfect tests in a way that ignores information and therefore is not guaranteed to improve over a single imperfect reference unless each component test has perfect specificity, and the CRS is conditionally independent of the index test. When these conditions are not met, as in the case of C. trachomatis testing, more realistic statistical models should be researched instead of relying on such CRSs.

  18. High accuracy flexural hinge development

    Science.gov (United States)

    Santos, I.; Ortiz de Zárate, I.; Migliorero, G.

    2005-07-01

    This document provides a synthesis of the technical results obtained in the frame of the HAFHA (High Accuracy Flexural Hinge Assembly) development performed by SENER (in charge of design, development, manufacturing and testing at component and mechanism levels) with EADS Astrium as subcontractor (in charge of doing an inventory of candidate applications among existing and emerging projects, establishing the requirements and perform system level testing) under ESA contract. The purpose of this project has been to develop a competitive technology for a flexural pivot, usuable in highly accurate and dynamic pointing/scanning mechanisms. Compared with other solutions (e.g. magnetic or ball bearing technologies) flexural hinges are the appropriate technology for guiding with accuracy a mobile payload over a limited angular ranges around one rotation axes.

  19. The upgraded PTB 600 m baseline: a high-accuracy reference for the calibration and the development of long distance measurement devices

    Science.gov (United States)

    Pollinger, Florian; Meyer, Tobias; Beyer, Jens; Doloca, Nicolae R.; Schellin, Wolfgang; Niemeier, Wolfgang; Jokela, Jorma; Häkli, Pasi; Abou-Zeid, Ahmed; Meiners-Hagen, Karl

    2012-09-01

    The calibration and verification of high-precision electronic distance meters (EDMs) requires well-characterized and calibrated geodetic baselines. As the length measurements are performed typically over several hundred metres in air, a thorough understanding of the environmental conditions is necessary. In the course of a major refurbishment, the 600 m baseline of the Physikalisch-Technische Bundesanstalt at Braunschweig, Germany, was equipped with a dense environmental sensor network. This paper presents the characterization of this novel reference baseline, including the calibration of the inter-pillar distances, and identifies the major sources of uncertainty for such a length standard. A preliminary expanded standard uncertainty (k = 2) of U ( l ) _{k=2}=\\sqrt{( 6.2 \\times 10^{-4} \\: m )^2 + ( 7.6 \\times 10^{-7} \\, l )^2} is deduced for single-slope distance comparisons on the baseline. In the course of a full calibration, the additive constant cEDM of an EDM can currently be determined with an expanded uncertainty of U(cEDM)k = 2 = 6.1 × 10-5 m, and its scale correction sEDM with an expanded uncertainty of U(sEDM)k = 2 = 8.2 × 10-7. As an example, a femtosecond laser-based distance measurement over 600 m on this baseline is presented.

  20. AN ASSESSMENT OF CITIZEN CONTRIBUTED GROUND REFERENCE DATA FOR LAND COVER MAP ACCURACY ASSESSMENT

    Directory of Open Access Journals (Sweden)

    G. M. Foody

    2015-08-01

    Full Text Available It is now widely accepted that an accuracy assessment should be part of a thematic mapping programme. Authoritative good or best practices for accuracy assessment have been defined but are often impractical to implement. Key reasons for this situation are linked to the ground reference data used in the accuracy assessment. Typically, it is a challenge to acquire a large sample of high quality reference cases in accordance to desired sampling designs specified as conforming to good practice and the data collected are normally to some degree imperfect limiting their value to an accuracy assessment which implicitly assumes the use of a gold standard reference. Citizen sensors have great potential to aid aspects of accuracy assessment. In particular, they may be able to act as a source of ground reference data that may, for example, reduce sample size problems but concerns with data quality remain. The relative strengths and limitations of citizen contributed data for accuracy assessment are reviewed in the context of the authoritative good practices defined for studies of land cover by remote sensing. The article will highlight some of the ways that citizen contributed data have been used in accuracy assessment as well as some of the problems that require further attention, and indicate some of the potential ways forward in the future.

  1. Accuracy Assessment of Mobile Mapping Point Clouds Using the Existing Environment as Terrestrial Reference

    Science.gov (United States)

    Hofmann, S.; Brenner, C.

    2016-06-01

    Mobile mapping data is widely used in various applications, what makes it especially important for data users to get a statistically verified quality statement on the geometric accuracy of the acquired point clouds or its processed products. The accuracy of point clouds can be divided into an absolute and a relative quality, where the absolute quality describes the position of the point cloud in a world coordinate system such as WGS84 or UTM, whereas the relative accuracy describes the accuracy within the point cloud itself. Furthermore, the quality of processed products such as segmented features depends on the global accuracy of the point cloud but mainly on the quality of the processing steps. Several data sources with different characteristics and quality can be thought of as potential reference data, such as cadastral maps, orthophoto, artificial control objects or terrestrial surveys using a total station. In this work a test field in a selected residential area was acquired as reference data in a terrestrial survey using a total station. In order to reach high accuracy the stationing of the total station was based on a newly made geodetic network with a local accuracy of less than 3 mm. The global position of the network was determined using a long time GNSS survey reaching an accuracy of 8 mm. Based on this geodetic network a 3D test field with facades and street profiles was measured with a total station, each point with a two-dimensional position and altitude. In addition, the surface of poles of street lights, traffic signs and trees was acquired using the scanning mode of the total station. Comparing this reference data to the acquired mobile mapping point clouds of several measurement campaigns a detailed quality statement on the accuracy of the point cloud data is made. Additionally, the advantages and disadvantages of the described reference data source concerning availability, cost, accuracy and applicability are discussed.

  2. High Accuracy Reference Network (HARN), Closed survey control network (between Order C class 1 and B depending on length of baseline) of 98 monumented points in Scott County - adjustment performed in NAD 1983/1996 HARN (conus), Published in 2005, Scott County.

    Data.gov (United States)

    NSGIC GIS Inventory (aka Ramona) — This High Accuracy Reference Network (HARN) dataset, was produced all or in part from Field Survey/GPS information as of 2005. It is described as 'Closed survey...

  3. Calibration of Robot Reference Frames for Enhanced Robot Positioning Accuracy

    OpenAIRE

    Cheng, Frank Shaopeng

    2008-01-01

    This chapter discussed the importance and methods of conducting robot workcell calibration for enhancing the accuracy of the robot TCP positions in industrial robot applications. It shows that the robot frame transformations define the robot geometric parameters such as joint position variables, link dimensions, and joint offsets in an industrial robot system. The D-H representation allows the robot designer to model the robot motion geometry with the four standard D-H parameters. The robot k...

  4. Calibration of Robot Reference Frames for Enhanced Robot Positioning Accuracy

    OpenAIRE

    Cheng, Frank Shaopeng

    2008-01-01

    This chapter discussed the importance and methods of conducting robot workcell calibration for enhancing the accuracy of the robot TCP positions in industrial robot applications. It shows that the robot frame transformations define the robot geometric parameters such as joint position variables, link dimensions, and joint offsets in an industrial robot system. The D-H representation allows the robot designer to model the robot motion geometry with the four standard D-H parameters. The robot k...

  5. CO2, CO, and CH4 measurements from tall towers in the NOAA Earth System Research Laboratory's Global Greenhouse Gas Reference Network: instrumentation, uncertainty analysis, and recommendations for future high-accuracy greenhouse gas monitoring efforts

    Science.gov (United States)

    Andrews, A. E.; Kofler, J. D.; Trudeau, M. E.; Williams, J. C.; Neff, D. H.; Masarie, K. A.; Chao, D. Y.; Kitzis, D. R.; Novelli, P. C.; Zhao, C. L.; Dlugokencky, E. J.; Lang, P. M.; Crotwell, M. J.; Fischer, M. L.; Parker, M. J.; Lee, J. T.; Baumann, D. D.; Desai, A. R.; Stanier, C. O.; De Wekker, S. F. J.; Wolfe, D. E.; Munger, J. W.; Tans, P. P.

    2014-02-01

    A reliable and precise in situ CO2 and CO analysis system has been developed and deployed at eight sites in the NOAA Earth System Research Laboratory's (ESRL) Global Greenhouse Gas Reference Network. The network uses very tall (> 300 m) television and radio transmitter towers that provide a convenient platform for mid-boundary-layer trace-gas sampling. Each analyzer has three sample inlets for profile sampling, and a complete vertical profile is obtained every 15 min. The instrument suite at one site has been augmented with a cavity ring-down spectrometer for measuring CO2 and CH4. The long-term stability of the systems in the field is typically better than 0.1 ppm for CO2, 6 ppb for CO, and 0.5 ppb for CH4, as determined from repeated standard gas measurements. The instrumentation is fully automated and includes sensors for measuring a variety of status parameters, such as temperatures, pressures, and flow rates, that are inputs for automated alerts and quality control algorithms. Detailed and time-dependent uncertainty estimates have been constructed for all of the gases, and the uncertainty framework could be readily adapted to other species or analysis systems. The design emphasizes use of off-the-shelf parts and modularity to facilitate network operations and ease of maintenance. The systems report high-quality data with > 93% uptime. Recurrent problems and limitations of the current system are discussed along with general recommendations for high-accuracy trace-gas monitoring. The network is a key component of the North American Carbon Program and a useful model for future research-grade operational greenhouse gas monitoring efforts.

  6. A multi breed reference improves genotype imputation accuracy in Nordic Red cattle

    DEFF Research Database (Denmark)

    Brøndum, Rasmus Froberg; Ma, Peipei; Lund, Mogens Sandø;

    2012-01-01

    612,615 SNPs on chromosome 1-29 remained for analysis. Validation was done by masking markers in true HD data and imputing them using Beagle v. 3.3 and a reference group of either national Red, combined Red or combined Red and Holstein bulls. Results show a decrease in allele error rate from 2.64, 1......The objective of this study was to investigate if a multi breed reference would improve genotype imputation accuracy from 50K to high density (HD) single nucleotide polymorphism (SNP) marker data in Nordic Red Dairy Cattle, compared to using only a single breed reference, and to check.......39 and 0.87 percent to 1.75, 0.59 and 0.54 percent for respectively Danish, Swedish and Fi nnish Red when going from single national reference to a combined Red reference. The larger error rate in the Danish population was caused by a subgroup of 10 animals showing a large proportion of Holstein genetics...

  7. A multi breed reference improves genotype imputation accuracy in Nordic Red cattle

    DEFF Research Database (Denmark)

    Brøndum, Rasmus Froberg; Ma, Peipei; Lund, Mogens Sandø;

    612,615 SNPs on chromosome 1-29 remained for analysis. Validation was done by masking markers in true HD data and imputing them using Beagle v. 3.3 and a reference group of either national Red, combined Red or combined Red and Holstein bulls. Results show a decrease in allele error rate from 2.64, 1......The objective of this study was to investigate if a multi breed reference would improve genotype imputation accuracy from 50K to high density (HD) single nucleotide polymorphism (SNP) marker data in Nordic Red Dairy Cattle, compared to using only a single breed reference, and to check.......39 and 0.87 percent to 1.75, 0.59 and 0.54 percent for respectively Danish, Swedish and Fi nnish Red when going from single national reference to a combined Red reference. The larger error rate in the Danish population was caused by a subgroup of 10 animals showing a large proportion of Holstein genetics...

  8. A review of solutions for diagnostic accuracy studies with an imperfect or missing reference standard

    NARCIS (Netherlands)

    J.B. Reitsma; A.W.S. Rutjes; K.S. Khan; A. Coomarasamy; P.M. Bossuyt

    2009-01-01

    Objective: In diagnostic accuracy studies, the reference standard may be imperfect or not available in all patients. We systematically reviewed the proposed solutions for these situations and generated methodological guidance. Study Design and Setting: Review of methodological articles. Results: We

  9. High Accuracy Imaging Polarimetry with NICMOS

    CERN Document Server

    Batcheldor, D; Hines, D C; Schmidt, G D; Axon, D J; Robinson, A; Sparks, W; Tadhunter, C

    2008-01-01

    The ability of NICMOS to perform high accuracy polarimetry is currently hampered by an uncalibrated residual instrumental polarization at a level of 1.2-1.5%. To better quantify and characterize this residual we obtained observations of three polarimetric standard stars at three separate space-craft roll angles. Combined with archival data, these observations were used to characterize the residual instrumental polarization to enable NICMOS to reach its full polarimetric potential. Using these data, we calculate values of the parallel transmission coefficients that reproduce the ground-based results for the polarimetric standards. The uncertainties associated with the parallel transmission coefficients, a result of the photometric repeatability of the observations, dominate the accuracy of p and theta. However, the new coefficients now enable imaging polarimetry of targets with p~1.0% at an accuracy of +/-0.6% and +/-15 degrees.

  10. Orthorectification of KOMPSAT Optical Images Using Various Ground Reference Data and Accuracy Assessment

    Directory of Open Access Journals (Sweden)

    Kwangjae Lee

    2017-01-01

    Full Text Available Along with the appearance of high resolution satellite images, image correction using Rational Polynomial Coefficients (RPCs has become common. Location accuracy of Korea Multipurpose Satellite (KOMPSAT standard images is still not adequate, so, in order to leverage the KOMPSAT images for applications such as mapping and change detection, it is necessary to orthorectify the images. In this study, using updated RPCs, we performed orthorectification of KOMPSAT-2, KOMPSAT-3, and KOMPSAT-3A images using various data. Through this study, we discovered that the orthorectification result using precise Ground Control Points (GCPs and Digital Elevation Model (DEM is the best, but it was found that the correction results through image matching are also excellent. In particular, it was confirmed that orthoimages with a planimetric accuracy around 3 m (Root Mean Square Error (RMSE can be generated by using well-known matching algorithms with open data such as OpenStreetMap (OSM and Shuttle Radar Topography Mission (SRTM DEM, which can be acquired by anyone. Although the accuracy was low in some mountainous terrain, it was confirmed that it could be used for generating KOMPSAT orthoimages using open data. This paper describes the results for orthorectifying high resolution KOMPSAT optical images using various reference data.

  11. High accuracy FIONA-AFM hybrid imaging.

    Science.gov (United States)

    Fronczek, D N; Quammen, C; Wang, H; Kisker, C; Superfine, R; Taylor, R; Erie, D A; Tessmer, I

    2011-04-01

    Multi-protein complexes are ubiquitous and play essential roles in many biological mechanisms. Single molecule imaging techniques such as electron microscopy (EM) and atomic force microscopy (AFM) are powerful methods for characterizing the structural properties of multi-protein and multi-protein-DNA complexes. However, a significant limitation to these techniques is the ability to distinguish different proteins from one another. Here, we combine high resolution fluorescence microscopy and AFM (FIONA-AFM) to allow the identification of different proteins in such complexes. Using quantum dots as fiducial markers in addition to fluorescently labeled proteins, we are able to align fluorescence and AFM information to ≥8nm accuracy. This accuracy is sufficient to identify individual fluorescently labeled proteins in most multi-protein complexes. We investigate the limitations of localization precision and accuracy in fluorescence and AFM images separately and their effects on the overall registration accuracy of FIONA-AFM hybrid images. This combination of the two orthogonal techniques (FIONA and AFM) opens a wide spectrum of possible applications to the study of protein interactions, because AFM can yield high resolution (5-10nm) information about the conformational properties of multi-protein complexes and the fluorescence can indicate spatial relationships of the proteins in the complexes.

  12. High Accuracy Transistor Compact Model Calibrations

    Energy Technology Data Exchange (ETDEWEB)

    Hembree, Charles E. [Sandia National Laboratories (SNL-NM), Albuquerque, NM (United States); Mar, Alan [Sandia National Laboratories (SNL-NM), Albuquerque, NM (United States); Robertson, Perry J. [Sandia National Laboratories (SNL-NM), Albuquerque, NM (United States)

    2015-09-01

    Typically, transistors are modeled by the application of calibrated nominal and range models. These models consists of differing parameter values that describe the location and the upper and lower limits of a distribution of some transistor characteristic such as current capacity. Correspond- ingly, when using this approach, high degrees of accuracy of the transistor models are not expected since the set of models is a surrogate for a statistical description of the devices. The use of these types of models describes expected performances considering the extremes of process or transistor deviations. In contrast, circuits that have very stringent accuracy requirements require modeling techniques with higher accuracy. Since these accurate models have low error in transistor descriptions, these models can be used to describe part to part variations as well as an accurate description of a single circuit instance. Thus, models that meet these stipulations also enable the calculation of quantifi- cation of margins with respect to a functional threshold and uncertainties in these margins. Given this need, new model high accuracy calibration techniques for bipolar junction transis- tors have been developed and are described in this report.

  13. A high-accuracy bandgap reference source used for curvature compensation of ADC%一种应用于ADC带曲率补偿的高精度带隙基准源

    Institute of Scientific and Technical Information of China (English)

    朱晓宇; 居水荣

    2015-01-01

    设计了一种应用于工作电压为1.8 V的流水型模数转换器(ADC)的带隙基准源。与传统电流模式带隙基准源不同,该带隙基准源采用曲率补偿技术,降低了温度系数,提高了精度。分析提高电源抑制比的方法,设计低压共源共栅电流镜偏置的折叠式共源共栅运放,提高了带隙基准源的电源抑制比。采用CSMC 0.18μm CMOS工艺,获得了900 mV的带隙基准, Spectre仿真结果表明,带隙基准源正常启动,在-40~125℃温度范围内温度系数低至3 ppm/℃,低频时的电源抑制比达89 dB。%A high⁃accuracy bandgap reference source used for curvature compensation of 1.8 V pipeline ADC was designed. Different from traditional current⁃mode bandgap reference source,the curvature compensation technology was adopted in this bandgap reference source,which reduced low temperature coefficient and improved precision. The methods to improve PSRR are analyzed in this paper. A folded cascode amplifier with the bias of high⁃swing cascode current mirrors was designed,which im⁃proved PSRR of bandgap reference source. Based on the CSMC 0.18 μm CMOS process,the bandgap reference gains an output voltage of 900 mV. Simulation results indicate that the circuit can start up normally,the temperature coefficient is 3 ppm/℃ be⁃tween -40 ℃ and 125 ℃ and the PSRR is 89 dB at low frequency.

  14. High accuracy 3-D laser radar

    DEFF Research Database (Denmark)

    Busck, Jens; Heiselberg, Henning

    2004-01-01

    We have developed a mono-static staring 3-D laser radar based on gated viewing with range accuracy below 1 m at 10 m and 1 cm at 100. We use a high sensitivity, fast, intensified CCD camera, and a Nd:Yag passively Q-switched 32.4 kHz pulsed green laser at 532 nm. The CCD has 752x582 pixels. Camera...

  15. Computing High Accuracy Power Spectra with Pico

    CERN Document Server

    Fendt, William A

    2007-01-01

    This paper presents the second release of Pico (Parameters for the Impatient COsmologist). Pico is a general purpose machine learning code which we have applied to computing the CMB power spectra and the WMAP likelihood. For this release, we have made improvements to the algorithm as well as the data sets used to train Pico, leading to a significant improvement in accuracy. For the 9 parameter nonflat case presented here Pico can on average compute the TT, TE and EE spectra to better than 1% of cosmic standard deviation for nearly all $\\ell$ values over a large region of parameter space. Performing a cosmological parameter analysis of current CMB and large scale structure data, we show that these power spectra give very accurate 1 and 2 dimensional parameter posteriors. We have extended Pico to allow computation of the tensor power spectrum and the matter transfer function. Pico runs about 1500 times faster than CAMB at the default accuracy and about 250,000 times faster at high accuracy. Training Pico can be...

  16. Influence of spatial temperature distribution on high accuracy interferometric metrology

    Science.gov (United States)

    Gu, Yongqiang; Miao, Erlong; Yan, Feng; Zhang, Jian; Yang, Huaijiang

    2010-10-01

    We calculate the influence of temperature change on the refractive index of air, establish a model of air temperature distribution and analyze the effect of different temperature distribution on the high accuracy interferometric metrology. First, a revised Edlen formula is employed to acquire the relation between temperature and refractive index of air, followed by introducing the fixed temperature gradient distribution among the spatial grid within the optical cavity between the reference flat and the test flat of the Fizeau interferometer, accompanied by a temperature change random function within each grid. Finally, all the rays through the air layer with different incident angles are traced by Matlab program in order to obtain the final output position, angle and OPD for each ray. The influence of different temperature distribution and the length of the optical cavity in on the testing accuracy can be analyzed through the RMS value that results from repeatable rays tracing. As a result, the horizontal distribution (vertical to optical axis) has a large effect on the testing accuracy. Thus, to realize the high accuracy figure metrology, the horizontal distribution of temperature must be rigorously controlled as well as to shorten the length of the optical cavity to a large extent. The results from our simulation are of great significant for the accuracy analysis of interferometric testing and the research of manufacturing a interferometer.

  17. Fast and High Accuracy Wire Scanner

    CERN Document Server

    Koujili, M; Koopman, J; Ramos, D; Sapinski, M; De Freitas, J; Ait Amira, Y; Djerdir, A

    2009-01-01

    Scanning of a high intensity particle beam imposes challenging requirements on a Wire Scanner system. It is expected to reach a scanning speed of 20 m.s-1 with a position accuracy of the order of 1 μm. In addition a timing accuracy better than 1 millisecond is needed. The adopted solution consists of a fork holding a wire rotating by a maximum of 200°. Fork, rotor and angular position sensor are mounted on the same axis and located in a chamber connected to the beam vacuum. The requirements imply the design of a system with extremely low vibration, vacuum compatibility, radiation and temperature tolerance. The adopted solution consists of a rotary brushless synchronous motor with the permanent magnet rotor installed inside of the vacuum chamber and the stator installed outside. The accurate position sensor will be mounted on the rotary shaft inside of the vacuum chamber, has to resist a bake-out temperature of 200°C and ionizing radiation up to a dozen of kGy/year. A digital feedback controller allows maxi...

  18. High accuracy 3-D laser radar

    DEFF Research Database (Denmark)

    Busck, Jens; Heiselberg, Henning

    2004-01-01

    We have developed a mono-static staring 3-D laser radar based on gated viewing with range accuracy below 1 m at 10 m and 1 cm at 100. We use a high sensitivity, fast, intensified CCD camera, and a Nd:Yag passively Q-switched 32.4 kHz pulsed green laser at 532 nm. The CCD has 752x582 pixels. Camera...... shutter is controlled in steps of 100 ps. Camera delay is controlled in steps of 100 ps. Each laser pulse triggers the camera delay and shutter. A 3-D image is constructed from a sequence of 50-100 2-D reflectivity images, where each frame integrates about 700 laser pulses on the CCD. In 50 Hz video mode...

  19. Novel method for high accuracy figure measurement of optical flat

    Science.gov (United States)

    E, Kewei; Li, Dahai; Yang, Lijie; Guo, Guangrao; Li, Mengyang; Wang, Xuemin; Zhang, Tao; Xiong, Zhao

    2017-01-01

    Phase Measuring Deflectometry (PMD) is a non-contact, high dynamic-range and full-field metrology which becomes a serious competitor to interferometry. However, the accuracy of deflectometry metrology is strongly influenced by the level of the calibrations, including test geometry, imaging pin-hole camera and digital display. In this paper, we propose a novel method that can measure optical flat surface figure to a high accuracy. We first calibrate the camera using a checker pattern shown on a LCD display at six different orientations, and the last orientation is aligned at the same position as the test optical flat. By using this method, lens distortions and the mapping relationship between the CCD pixels and the subaperture coordinates on the test optical flat can be determined at the same time. To further reduce the influence of the calibration errors on measurements, a reference optical flat with a high quality surface is measured, and then the system errors in our PMD setup can be eliminated by subtracting the figure of the reference flat from the figure of the test flat. Although any expensive coordinates measuring machine, such as laser tracker and coordinates measuring machine are not applied in our measurement, our experimental results of optical flat figure from low to high order aberrations still show a good agreement with that from the Fizeau interferometer.

  20. The use of low density high accuracy (LDHA) data for correction of high density low accuracy (HDLA) point cloud

    Science.gov (United States)

    Rak, Michal Bartosz; Wozniak, Adam; Mayer, J. R. R.

    2016-06-01

    Coordinate measuring techniques rely on computer processing of coordinate values of points gathered from physical surfaces using contact or non-contact methods. Contact measurements are characterized by low density and high accuracy. On the other hand optical methods gather high density data of the whole object in a short time but with accuracy at least one order of magnitude lower than for contact measurements. Thus the drawback of contact methods is low density of data, while for non-contact methods it is low accuracy. In this paper a method for fusion of data from two measurements of fundamentally different nature: high density low accuracy (HDLA) and low density high accuracy (LDHA) is presented to overcome the limitations of both measuring methods. In the proposed method the concept of virtual markers is used to find a representation of pairs of corresponding characteristic points in both sets of data. In each pair the coordinates of the point from contact measurements is treated as a reference for the corresponding point from non-contact measurement. Transformation enabling displacement of characteristic points from optical measurement to their match from contact measurements is determined and applied to the whole point cloud. The efficiency of the proposed algorithm was evaluated by comparison with data from a coordinate measuring machine (CMM). Three surfaces were used for this evaluation: plane, turbine blade and engine cover. For the planar surface the achieved improvement was of around 200 μm. Similar results were obtained for the turbine blade but for the engine cover the improvement was smaller. For both freeform surfaces the improvement was higher for raw data than for data after creation of mesh of triangles.

  1. High-accuracy determination for optical indicatrix rotation in ferroelectric DTGS

    OpenAIRE

    O.S.Kushnir; O.A.Bevz; O.G.Vlokh

    2000-01-01

    Optical indicatrix rotation in deuterated ferroelectric triglycine sulphate is studied with the high-accuracy null-polarimetric technique. The behaviour of the effect in ferroelectric phase is referred to quadratic spontaneous electrooptics.

  2. Intonation in unaccompanied singing: accuracy, drift, and a model of reference pitch memory.

    Science.gov (United States)

    Mauch, Matthias; Frieler, Klaus; Dixon, Simon

    2014-07-01

    This paper presents a study on intonation and intonation drift in unaccompanied singing, and proposes a simple model of reference pitch memory that accounts for many of the effects observed. Singing experiments were conducted with 24 singers of varying ability under three conditions (Normal, Masked, Imagined). Over the duration of a recording, ∼50 s, a median absolute intonation drift of 11 cents was observed. While smaller than the median note error (19 cents), drift was significant in 22% of recordings. Drift magnitude did not correlate with other measures of singing accuracy, singing experience, or the presence of conditions tested. Furthermore, it is shown that neither a static intonation memory model nor a memoryless interval-based intonation model can account for the accuracy and drift behavior observed. The proposed causal model provides a better explanation as it treats the reference pitch as a changing latent variable.

  3. A SINGLE STEP SCHEME WITH HIGH ACCURACY FOR PARABOLIC PROBLEM

    Institute of Scientific and Technical Information of China (English)

    陈传淼; 胡志刚

    2001-01-01

    A single step scheme with high accuracy for solving parabolic problem is proposed. It is shown that this scheme possesses good stability and fourth order accuracy with respect to both time and space variables, which are superconvergent.

  4. Accuracy of ELISA detection methods for gluten and reference materials: a realistic assessment.

    Science.gov (United States)

    Diaz-Amigo, Carmen; Popping, Bert

    2013-06-19

    The determination of prolamins by ELISA and subsequent conversion of the resulting concentration to gluten content in food appears to be a comparatively simple and straightforward process with which many laboratories have years-long experience. At the end of the process, a value of gluten, expressed in mg/kg or ppm, is obtained. This value often is the basis for the decision if a product can be labeled gluten-free or not. On the basis of currently available scientific information, the accuracy of the obtained values with commonly used commercial ELISA kits has to be questioned. Although recently several multilaboratory studies have been conducted in an attempt to emphasize and ensure the accuracy of the results, data suggest that it was the precision of these assays, not the accuracy, that was confirmed because some of the underlying assumptions for calculating the gluten content lack scientific data support as well as appropriate reference materials for comparison. This paper discusses the issues of gluten determination and quantification with respect to antibody specificity, extraction procedures, reference materials, and their commutability.

  5. A Multilaboratory Comparison of Calibration Accuracy and the Performance of External References in Analytical Ultracentrifugation

    Science.gov (United States)

    Zhao, Huaying; Ghirlando, Rodolfo; Alfonso, Carlos; Arisaka, Fumio; Attali, Ilan; Bain, David L.; Bakhtina, Marina M.; Becker, Donald F.; Bedwell, Gregory J.; Bekdemir, Ahmet; Besong, Tabot M. D.; Birck, Catherine; Brautigam, Chad A.; Brennerman, William; Byron, Olwyn; Bzowska, Agnieszka; Chaires, Jonathan B.; Chaton, Catherine T.; Cölfen, Helmut; Connaghan, Keith D.; Crowley, Kimberly A.; Curth, Ute; Daviter, Tina; Dean, William L.; Díez, Ana I.; Ebel, Christine; Eckert, Debra M.; Eisele, Leslie E.; Eisenstein, Edward; England, Patrick; Escalante, Carlos; Fagan, Jeffrey A.; Fairman, Robert; Finn, Ron M.; Fischle, Wolfgang; de la Torre, José García; Gor, Jayesh; Gustafsson, Henning; Hall, Damien; Harding, Stephen E.; Cifre, José G. Hernández; Herr, Andrew B.; Howell, Elizabeth E.; Isaac, Richard S.; Jao, Shu-Chuan; Jose, Davis; Kim, Soon-Jong; Kokona, Bashkim; Kornblatt, Jack A.; Kosek, Dalibor; Krayukhina, Elena; Krzizike, Daniel; Kusznir, Eric A.; Kwon, Hyewon; Larson, Adam; Laue, Thomas M.; Le Roy, Aline; Leech, Andrew P.; Lilie, Hauke; Luger, Karolin; Luque-Ortega, Juan R.; Ma, Jia; May, Carrie A.; Maynard, Ernest L.; Modrak-Wojcik, Anna; Mok, Yee-Foong; Mücke, Norbert; Nagel-Steger, Luitgard; Narlikar, Geeta J.; Noda, Masanori; Nourse, Amanda; Obsil, Tomas; Park, Chad K.; Park, Jin-Ku; Pawelek, Peter D.; Perdue, Erby E.; Perkins, Stephen J.; Perugini, Matthew A.; Peterson, Craig L.; Peverelli, Martin G.; Piszczek, Grzegorz; Prag, Gali; Prevelige, Peter E.; Raynal, Bertrand D. E.; Rezabkova, Lenka; Richter, Klaus; Ringel, Alison E.; Rosenberg, Rose; Rowe, Arthur J.; Rufer, Arne C.; Scott, David J.; Seravalli, Javier G.; Solovyova, Alexandra S.; Song, Renjie; Staunton, David; Stoddard, Caitlin; Stott, Katherine; Strauss, Holger M.; Streicher, Werner W.; Sumida, John P.; Swygert, Sarah G.; Szczepanowski, Roman H.; Tessmer, Ingrid; Toth, Ronald T.; Tripathy, Ashutosh; Uchiyama, Susumu; Uebel, Stephan F. W.; Unzai, Satoru; Gruber, Anna Vitlin; von Hippel, Peter H.; Wandrey, Christine; Wang, Szu-Huan; Weitzel, Steven E.; Wielgus-Kutrowska, Beata; Wolberger, Cynthia; Wolff, Martin; Wright, Edward; Wu, Yu-Sung; Wubben, Jacinta M.; Schuck, Peter

    2015-01-01

    Analytical ultracentrifugation (AUC) is a first principles based method to determine absolute sedimentation coefficients and buoyant molar masses of macromolecules and their complexes, reporting on their size and shape in free solution. The purpose of this multi-laboratory study was to establish the precision and accuracy of basic data dimensions in AUC and validate previously proposed calibration techniques. Three kits of AUC cell assemblies containing radial and temperature calibration tools and a bovine serum albumin (BSA) reference sample were shared among 67 laboratories, generating 129 comprehensive data sets. These allowed for an assessment of many parameters of instrument performance, including accuracy of the reported scan time after the start of centrifugation, the accuracy of the temperature calibration, and the accuracy of the radial magnification. The range of sedimentation coefficients obtained for BSA monomer in different instruments and using different optical systems was from 3.655 S to 4.949 S, with a mean and standard deviation of (4.304 ± 0.188) S (4.4%). After the combined application of correction factors derived from the external calibration references for elapsed time, scan velocity, temperature, and radial magnification, the range of s-values was reduced 7-fold with a mean of 4.325 S and a 6-fold reduced standard deviation of ± 0.030 S (0.7%). In addition, the large data set provided an opportunity to determine the instrument-to-instrument variation of the absolute radial positions reported in the scan files, the precision of photometric or refractometric signal magnitudes, and the precision of the calculated apparent molar mass of BSA monomer and the fraction of BSA dimers. These results highlight the necessity and effectiveness of independent calibration of basic AUC data dimensions for reliable quantitative studies. PMID:25997164

  6. A multilaboratory comparison of calibration accuracy and the performance of external references in analytical ultracentrifugation.

    Directory of Open Access Journals (Sweden)

    Huaying Zhao

    Full Text Available Analytical ultracentrifugation (AUC is a first principles based method to determine absolute sedimentation coefficients and buoyant molar masses of macromolecules and their complexes, reporting on their size and shape in free solution. The purpose of this multi-laboratory study was to establish the precision and accuracy of basic data dimensions in AUC and validate previously proposed calibration techniques. Three kits of AUC cell assemblies containing radial and temperature calibration tools and a bovine serum albumin (BSA reference sample were shared among 67 laboratories, generating 129 comprehensive data sets. These allowed for an assessment of many parameters of instrument performance, including accuracy of the reported scan time after the start of centrifugation, the accuracy of the temperature calibration, and the accuracy of the radial magnification. The range of sedimentation coefficients obtained for BSA monomer in different instruments and using different optical systems was from 3.655 S to 4.949 S, with a mean and standard deviation of (4.304 ± 0.188 S (4.4%. After the combined application of correction factors derived from the external calibration references for elapsed time, scan velocity, temperature, and radial magnification, the range of s-values was reduced 7-fold with a mean of 4.325 S and a 6-fold reduced standard deviation of ± 0.030 S (0.7%. In addition, the large data set provided an opportunity to determine the instrument-to-instrument variation of the absolute radial positions reported in the scan files, the precision of photometric or refractometric signal magnitudes, and the precision of the calculated apparent molar mass of BSA monomer and the fraction of BSA dimers. These results highlight the necessity and effectiveness of independent calibration of basic AUC data dimensions for reliable quantitative studies.

  7. A Multilaboratory Comparison of Calibration Accuracy and the Performance of External References in Analytical Ultracentrifugation

    KAUST Repository

    Zhao, Huaying

    2015-05-21

    Analytical ultracentrifugation (AUC) is a first principles based method to determine absolute sedimentation coefficients and buoyant molar masses of macromolecules and their complexes, reporting on their size and shape in free solution. The purpose of this multi-laboratory study was to establish the precision and accuracy of basic data dimensions in AUC and validate previously proposed calibration techniques. Three kits of AUC cell assemblies containing radial and temperature calibration tools and a bovine serum albumin (BSA) reference sample were shared among 67 laboratories, generating 129 comprehensive data sets. These allowed for an assessment of many parameters of instrument performance, including accuracy of the reported scan time after the start of centrifugation, the accuracy of the temperature calibration, and the accuracy of the radial magnification. The range of sedimentation coefficients obtained for BSA monomer in different instruments and using different optical systems was from 3.655 S to 4.949 S, with a mean and standard deviation of (4.304 ± 0.188) S (4.4%). After the combined application of correction factors derived from the external calibration references for elapsed time, scan velocity, temperature, and radial magnification, the range of s-values was reduced 7-fold with a mean of 4.325 S and a 6-fold reduced standard deviation of ± 0.030 S (0.7%). In addition, the large data set provided an opportunity to determine the instrument-to-instrument variation of the absolute radial positions reported in the scan files, the precision of photometric or refractometric signal magnitudes, and the precision of the calculated apparent molar mass of BSA monomer and the fraction of BSA dimers. These results highlight the necessity and effectiveness of independent calibration of basic AUC data dimensions for reliable quantitative studies.

  8. Methodology for high accuracy contact angle measurement.

    Science.gov (United States)

    Kalantarian, A; David, R; Neumann, A W

    2009-12-15

    A new version of axisymmetric drop shape analysis (ADSA) called ADSA-NA (ADSA-no apex) was developed for measuring interfacial properties for drop configurations without an apex. ADSA-NA facilitates contact angle measurements on drops with a capillary protruding into the drop. Thus a much simpler experimental setup, not involving formation of a complete drop from below through a hole in the test surface, may be used. The contact angles of long-chained alkanes on a commercial fluoropolymer, Teflon AF 1600, were measured using the new method. A new numerical scheme was incorporated into the image processing to improve the location of the contact points of the liquid meniscus with the solid substrate to subpixel resolution. The images acquired in the experiments were also analyzed by a different drop shape technique called theoretical image fitting analysis-axisymmetric interfaces (TIFA-AI). The results were compared with literature values obtained by means of the standard ADSA for sessile drops with the apex. Comparison of the results from ADSA-NA with those from TIFA-AI and ADSA reveals that, with different numerical strategies and experimental setups, contact angles can be measured with an accuracy of less than 0.2 degrees. Contact angles and surface tensions measured from drops with no apex, i.e., by means of ADSA-NA and TIFA-AI, were considerably less scattered than those from complete drops with apex. ADSA-NA was also used to explore sources of improvement in contact angle resolution. It was found that using an accurate value of surface tension as an input enhances the accuracy of contact angle measurements.

  9. A reference dataset for deformable image registration spatial accuracy evaluation using the COPDgene study archive.

    Science.gov (United States)

    Castillo, Richard; Castillo, Edward; Fuentes, David; Ahmad, Moiz; Wood, Abbie M; Ludwig, Michelle S; Guerrero, Thomas

    2013-05-07

    Landmark point-pairs provide a strategy to assess deformable image registration (DIR) accuracy in terms of the spatial registration of the underlying anatomy depicted in medical images. In this study, we propose to augment a publicly available database (www.dir-lab.com) of medical images with large sets of manually identified anatomic feature pairs between breath-hold computed tomography (BH-CT) images for DIR spatial accuracy evaluation. Ten BH-CT image pairs were randomly selected from the COPDgene study cases. Each patient had received CT imaging of the entire thorax in the supine position at one-fourth dose normal expiration and maximum effort full dose inspiration. Using dedicated in-house software, an imaging expert manually identified large sets of anatomic feature pairs between images. Estimates of inter- and intra-observer spatial variation in feature localization were determined by repeat measurements of multiple observers over subsets of randomly selected features. 7298 anatomic landmark features were manually paired between the 10 sets of images. Quantity of feature pairs per case ranged from 447 to 1172. Average 3D Euclidean landmark displacements varied substantially among cases, ranging from 12.29 (SD: 6.39) to 30.90 (SD: 14.05) mm. Repeat registration of uniformly sampled subsets of 150 landmarks for each case yielded estimates of observer localization error, which ranged in average from 0.58 (SD: 0.87) to 1.06 (SD: 2.38) mm for each case. The additions to the online web database (www.dir-lab.com) described in this work will broaden the applicability of the reference data, providing a freely available common dataset for targeted critical evaluation of DIR spatial accuracy performance in multiple clinical settings. Estimates of observer variance in feature localization suggest consistent spatial accuracy for all observers across both four-dimensional CT and COPDgene patient cohorts.

  10. High accuracy GNSS based navigation in GEO

    Science.gov (United States)

    Capuano, Vincenzo; Shehaj, Endrit; Blunt, Paul; Botteron, Cyril; Farine, Pierre-André

    2017-07-01

    Although significant improvements in efficiency and performance of communication satellites have been achieved in the past decades, it is expected that the demand for new platforms in Geostationary Orbit (GEO) and for the On-Orbit Servicing (OOS) on the existing ones will continue to rise. Indeed, the GEO orbit is used for many applications including direct broadcast as well as communications. At the same time, Global Navigation Satellites System (GNSS), originally designed for land, maritime and air applications, has been successfully used as navigation system in Low Earth Orbit (LEO) and its further utilization for navigation of geosynchronous satellites becomes a viable alternative offering many advantages over present ground based methods. Following our previous studies of GNSS signal characteristics in Medium Earth Orbit (MEO), GEO and beyond, in this research we specifically investigate the processing of different GNSS signals, with the goal to determine the best navigation performance they can provide in a GEO mission. Firstly, a detailed selection among different GNSS signals and different combinations of them is discussed, taking into consideration the L1 and L5 frequency bands, and the GPS and Galileo constellations. Then, the implementation of an Orbital Filter is summarized, which adaptively fuses the GN1SS observations with an accurate orbital forces model. Finally, simulation tests of the navigation performance achievable by processing the selected combination of GNSS signals are carried out. The results obtained show an achievable positioning accuracy of less than one meter. In addition, hardware-in-the-loop tests are presented using a COTS receiver connected to our GNSS Spirent simulator, in order to collect real-time hardware-in-the-loop observations and process them by the proposed navigation module.

  11. Compact, High Accuracy CO2 Monitor Project

    Data.gov (United States)

    National Aeronautics and Space Administration — This Small Business Innovative Research Phase II proposal seeks to develop a low cost, robust, highly precise and accurate CO2 monitoring system. This system will...

  12. Compact, High Accuracy CO2 Monitor Project

    Data.gov (United States)

    National Aeronautics and Space Administration — This Small Business Innovative Research Phase I proposal seeks to develop a low cost, robust, highly precise and accurate CO2 monitoring system. This system will...

  13. High speed high dynamic range high accuracy measurement system

    Energy Technology Data Exchange (ETDEWEB)

    Deibele, Craig E.; Curry, Douglas E.; Dickson, Richard W.; Xie, Zaipeng

    2016-11-29

    A measuring system includes an input that emulates a bandpass filter with no signal reflections. A directional coupler connected to the input passes the filtered input to electrically isolated measuring circuits. Each of the measuring circuits includes an amplifier that amplifies the signal through logarithmic functions. The output of the measuring system is an accurate high dynamic range measurement.

  14. Improving Inverse Dynamics Accuracy in a Planar Walking Model Based on Stable Reference Point

    Directory of Open Access Journals (Sweden)

    Alaa Abdulrahman

    2014-01-01

    Full Text Available Physiologically and biomechanically, the human body represents a complicated system with an abundance of degrees of freedom (DOF. When developing mathematical representations of the body, a researcher has to decide on how many of those DOF to include in the model. Though accuracy can be enhanced at the cost of complexity by including more DOF, their necessity must be rigorously examined. In this study a planar seven-segment human body walking model with single DOF joints was developed. A reference point was added to the model to track the body’s global position while moving. Due to the kinematic instability of the pelvis, the top of the head was selected as the reference point, which also assimilates the vestibular sensor position. Inverse dynamics methods were used to formulate and solve the equations of motion based on Newton-Euler formulae. The torques and ground reaction forces generated by the planar model during a regular gait cycle were compared with similar results from a more complex three-dimensional OpenSim model with muscles, which resulted in correlation errors in the range of 0.9–0.98. The close comparison between the two torque outputs supports the use of planar models in gait studies.

  15. Researches on High Accuracy Prediction Methods of Earth Orientation Parameters

    Science.gov (United States)

    Xu, X. Q.

    2015-09-01

    The Earth rotation reflects the coupling process among the solid Earth, atmosphere, oceans, mantle, and core of the Earth on multiple spatial and temporal scales. The Earth rotation can be described by the Earth's orientation parameters, which are abbreviated as EOP (mainly including two polar motion components PM_X and PM_Y, and variation in the length of day ΔLOD). The EOP is crucial in the transformation between the terrestrial and celestial reference systems, and has important applications in many areas such as the deep space exploration, satellite precise orbit determination, and astrogeodynamics. However, the EOP products obtained by the space geodetic technologies generally delay by several days to two weeks. The growing demands for modern space navigation make high-accuracy EOP prediction be a worthy topic. This thesis is composed of the following three aspects, for the purpose of improving the EOP forecast accuracy. (1) We analyze the relation between the length of the basic data series and the EOP forecast accuracy, and compare the EOP prediction accuracy for the linear autoregressive (AR) model and the nonlinear artificial neural network (ANN) method by performing the least squares (LS) extrapolations. The results show that the high precision forecast of EOP can be realized by appropriate selection of the basic data series length according to the required time span of EOP prediction: for short-term prediction, the basic data series should be shorter, while for the long-term prediction, the series should be longer. The analysis also showed that the LS+AR model is more suitable for the short-term forecasts, while the LS+ANN model shows the advantages in the medium- and long-term forecasts. (2) We develop for the first time a new method which combines the autoregressive model and Kalman filter (AR+Kalman) in short-term EOP prediction. The equations of observation and state are established using the EOP series and the autoregressive coefficients

  16. High accuracy in silico sulfotransferase models.

    Science.gov (United States)

    Cook, Ian; Wang, Ting; Falany, Charles N; Leyh, Thomas S

    2013-11-29

    Predicting enzymatic behavior in silico is an integral part of our efforts to understand biology. Hundreds of millions of compounds lie in targeted in silico libraries waiting for their metabolic potential to be discovered. In silico "enzymes" capable of accurately determining whether compounds can inhibit or react is often the missing piece in this endeavor. This problem has now been solved for the cytosolic sulfotransferases (SULTs). SULTs regulate the bioactivities of thousands of compounds--endogenous metabolites, drugs and other xenobiotics--by transferring the sulfuryl moiety (SO3) from 3'-phosphoadenosine 5'-phosphosulfate to the hydroxyls and primary amines of these acceptors. SULT1A1 and 2A1 catalyze the majority of sulfation that occurs during human Phase II metabolism. Here, recent insights into the structure and dynamics of SULT binding and reactivity are incorporated into in silico models of 1A1 and 2A1 that are used to identify substrates and inhibitors in a structurally diverse set of 1,455 high value compounds: the FDA-approved small molecule drugs. The SULT1A1 models predict 76 substrates. Of these, 53 were known substrates. Of the remaining 23, 21 were tested, and all were sulfated. The SULT2A1 models predict 22 substrates, 14 of which are known substrates. Of the remaining 8, 4 were tested, and all are substrates. The models proved to be 100% accurate in identifying substrates and made no false predictions at Kd thresholds of 100 μM. In total, 23 "new" drug substrates were identified, and new linkages to drug inhibitors are predicted. It now appears to be possible to accurately predict Phase II sulfonation in silico.

  17. High accuracy & long timescale light curves

    Directory of Open Access Journals (Sweden)

    Hodgkin S.

    2013-04-01

    Full Text Available We present a theoretical analysis of the optical light curves (LCs for short-period high-mass transiting extrasolar planet systems. Our method considers the primary transit, the secondary eclipse, and the overall phase shape of the LC between the occultations. Phase variations arise from (i reflected and thermally emitted light by the planet, (ii the ellipsoidal shape of the star due to the gravitational pull of the planet, and (iii the Doppler shift of the stellar light as the star orbits the center of mass of the system. Our full model of the out-of-eclipse variations contains information about the planetary mass, orbital eccentricity, the orientation of periastron and the planet's albedo. For a range of hypothetical systems we demonstrate that the ellipsoidal variations (ii. can be large enough to be distinguished from the remaining components and that this effect can be used to constrain the planet's mass. As an example we presend KOI-13b (candidate exoplanet system included in the September 2011 Kepler data release. The Kepler light curve shows both primary and secondary eclipses, as well as significant out-of-eclipse light curve variations. We model the relative contributions from (i thermal emission from the companion, (ii planetary reflected light, (iii doppler beaming, and (iv ellipsoidal variations in the host-star arising from the tidal distortion of the host star by its companion. Our analysis, based on the light curve alone, enables us to constrain the mass of the KOI-13.01 companion to be MC = 8.3 ± 1.25 MJ and thus demonstrates that the transiting companion is a planet. The teqnique is useful for current and future space missions such as Kepler and PLATO.

  18. A high-accuracy DCO with hybrid architecture

    Science.gov (United States)

    Sun, Yapeng; Zhao, Huidong; Qiao, Shushan; Hei, Yong; Zhang, Fuhai

    2017-07-01

    In this paper, a novel hybrid digital-controlled oscillator (DCO) is proposed, which is used to improve the accuracy of the all-digital clock generator without reference source. The DCO with hybrid architecture consists of two parts: DCO_high and DCO_low. The DCO_high decides the coarse output frequency of DCO, and adopts the cascade structure to decrease the area. The DCO_low adopts the chain structure with three-state buffer, and decides the fine output frequency of DCO. Compared with traditional cascade DCO, the proposed hybrid DCO features higher precision with less inherent delay. Therefore the clock generator can tolerate process, voltage and temperature (PVT) variation and meet the needs of different conditions. The DCO is designed in SMIC 180 nm CMOS process with 0.021 mm2 chip area. The output frequency is adjusted from 15-120 MHz. The frequency error is less than 0.83% at 25 MHz with 1.6-1.8 V supply voltage and 0-80 °C temperature variations in TT, FF, SS corners. Project supported by the National Natural Science Foundation of China (Nos. 61306025, 61474135).

  19. High accuracy autonomous navigation using the global positioning system (GPS)

    Science.gov (United States)

    Truong, Son H.; Hart, Roger C.; Shoan, Wendy C.; Wood, Terri; Long, Anne C.; Oza, Dipak H.; Lee, Taesul

    1997-01-01

    The application of global positioning system (GPS) technology to the improvement of the accuracy and economy of spacecraft navigation, is reported. High-accuracy autonomous navigation algorithms are currently being qualified in conjunction with the GPS attitude determination flyer (GADFLY) experiment for the small satellite technology initiative Lewis spacecraft. Preflight performance assessments indicated that these algorithms are able to provide a real time total position accuracy of better than 10 m and a velocity accuracy of better than 0.01 m/s, with selective availability at typical levels. It is expected that the position accuracy will be increased to 2 m if corrections are provided by the GPS wide area augmentation system.

  20. Systematic Calibration for Ultra-High Accuracy Inertial Measurement Units.

    Science.gov (United States)

    Cai, Qingzhong; Yang, Gongliu; Song, Ningfang; Liu, Yiliang

    2016-06-22

    An inertial navigation system (INS) has been widely used in challenging GPS environments. With the rapid development of modern physics, an atomic gyroscope will come into use in the near future with a predicted accuracy of 5 × 10(-6)°/h or better. However, existing calibration methods and devices can not satisfy the accuracy requirements of future ultra-high accuracy inertial sensors. In this paper, an improved calibration model is established by introducing gyro g-sensitivity errors, accelerometer cross-coupling errors and lever arm errors. A systematic calibration method is proposed based on a 51-state Kalman filter and smoother. Simulation results show that the proposed calibration method can realize the estimation of all the parameters using a common dual-axis turntable. Laboratory and sailing tests prove that the position accuracy in a five-day inertial navigation can be improved about 8% by the proposed calibration method. The accuracy can be improved at least 20% when the position accuracy of the atomic gyro INS can reach a level of 0.1 nautical miles/5 d. Compared with the existing calibration methods, the proposed method, with more error sources and high order small error parameters calibrated for ultra-high accuracy inertial measurement units (IMUs) using common turntables, has a great application potential in future atomic gyro INSs.

  1. Systematic Calibration for Ultra-High Accuracy Inertial Measurement Units

    Directory of Open Access Journals (Sweden)

    Qingzhong Cai

    2016-06-01

    Full Text Available An inertial navigation system (INS has been widely used in challenging GPS environments. With the rapid development of modern physics, an atomic gyroscope will come into use in the near future with a predicted accuracy of 5 × 10−6°/h or better. However, existing calibration methods and devices can not satisfy the accuracy requirements of future ultra-high accuracy inertial sensors. In this paper, an improved calibration model is established by introducing gyro g-sensitivity errors, accelerometer cross-coupling errors and lever arm errors. A systematic calibration method is proposed based on a 51-state Kalman filter and smoother. Simulation results show that the proposed calibration method can realize the estimation of all the parameters using a common dual-axis turntable. Laboratory and sailing tests prove that the position accuracy in a five-day inertial navigation can be improved about 8% by the proposed calibration method. The accuracy can be improved at least 20% when the position accuracy of the atomic gyro INS can reach a level of 0.1 nautical miles/5 d. Compared with the existing calibration methods, the proposed method, with more error sources and high order small error parameters calibrated for ultra-high accuracy inertial measurement units (IMUs using common turntables, has a great application potential in future atomic gyro INSs.

  2. Graphite thermal expansion reference for high temperature

    Science.gov (United States)

    Gaal, P. S.

    1974-01-01

    The design requirements of the aerospace and high-temperature nuclear reactor industries necessitate reliable thermal expansion data for graphite and other carbonaceous materials. The feasibility of an acceptable reference for calibration of expansion measuring systems that operate in carbon-rich atmospheres at temperatures ranging to 2500 C is the prime subject of this work. Present-day graphite technology provides acceptable materials for stable, reproducible references, as reflected by some of the candidate materials. The repeatability for a single specimen in a given expansion measuring system was found to be plus or minus 1%, while the combined results of several tests made on a number of samples fell within a plus or minus 2.5% band.

  3. Effect of predictor traits on accuracy of genomic breeding values for feed intake based on a limited cow reference population.

    Science.gov (United States)

    Pszczola, M; Veerkamp, R F; de Haas, Y; Wall, E; Strabel, T; Calus, M P L

    2013-11-01

    The genomic breeding value accuracy of scarcely recorded traits is low because of the limited number of phenotypic observations. One solution to increase the breeding value accuracy is to use predictor traits. This study investigated the impact of recording additional phenotypic observations for predictor traits on reference and evaluated animals on the genomic breeding value accuracy for a scarcely recorded trait. The scarcely recorded trait was dry matter intake (DMI, n = 869) and the predictor traits were fat-protein-corrected milk (FPCM, n = 1520) and live weight (LW, n = 1309). All phenotyped animals were genotyped and originated from research farms in Ireland, the United Kingdom and the Netherlands. Multi-trait REML was used to simultaneously estimate variance components and breeding values for DMI using available predictors. In addition, analyses using only pedigree relationships were performed. Breeding value accuracy was assessed through cross-validation (CV) and prediction error variance (PEV). CV groups (n = 7) were defined by splitting animals across genetic lines and management groups within country. With no additional traits recorded for the evaluated animals, both CV- and PEV-based accuracies for DMI were substantially higher for genomic than for pedigree analyses (CV: max. 0.26 for pedigree and 0.33 for genomic analyses; PEV: max. 0.45 and 0.52, respectively). With additional traits available, the differences between pedigree and genomic accuracies diminished. With additional recording for FPCM, pedigree accuracies increased from 0.26 to 0.47 for CV and from 0.45 to 0.48 for PEV. Genomic accuracies increased from 0.33 to 0.50 for CV and from 0.52 to 0.53 for PEV. With additional recording for LW instead of FPCM, pedigree accuracies increased to 0.54 for CV and to 0.61 for PEV. Genomic accuracies increased to 0.57 for CV and to 0.60 for PEV. With both FPCM and LW available for evaluated animals, accuracy was highest (0.62 for CV and 0.61 for PEV in

  4. Dynamic PL&T using Two Reference Nodes Equipped with Steered Directional Antenna for Significant PL&T Accuracy

    CERN Document Server

    Shakhakarmi, Niraj

    2012-01-01

    Dynamic Position Location and Tracking (PL&T) is proposed deploying the integrated approach of zone finding and triangulation using two friendly nodes equipped with Steered Directional Antenna (DA) in Mobile Ad hoc Networks (MANET). This approach allows the system to use only two references instead of a typical 3 references for a straight triangulation. Moreover, the performance of the proposed algorithm with references using directional antennas shows significant improvement over triangulation using references with Omnidirectional antennas as the beam power is concentrated. However, dynamic switching of reference nodes is frequently required as the target moves outside the predicted zone. This paper presents a better tracking accuracy in using proposed dynamic PL&T as compared to other PL&T techniques. The multipath fading is also addressed with the use of KV transform coding technique which uses forward error correction and sample interleaving achieves greater than 90% tracking accuracy with BER...

  5. MRI screening for silicone breast implant rupture: accuracy, inter- and intraobserver variability using explantation results as reference standard

    Energy Technology Data Exchange (ETDEWEB)

    Maijers, M.C.; Ritt, M.J.P.F. [VU University Medical Centre, Department of Plastic, Reconstructive and Hand Surgery, De Boelelaan 1117, PO Box 7057, Amsterdam (Netherlands); Niessen, F.B. [VU University Medical Centre, Department of Plastic, Reconstructive and Hand Surgery, De Boelelaan 1117, PO Box 7057, Amsterdam (Netherlands); Jan van Goyen Clinic, Department of Plastic Surgery, Amsterdam (Netherlands); Veldhuizen, J.F.H. [MRI Centre, Amsterdam (Netherlands); Manoliu, R.A. [MRI Centre, Amsterdam (Netherlands); VU University Medical Centre, Department of Radiology, Amsterdam (Netherlands)

    2014-06-15

    The recall of Poly Implant Prothese (PIP) silicone breast implants in 2010 resulted in large numbers of asymptomatic women with implants who underwent magnetic resonance imaging (MRI) screening. This study's aim was to assess the accuracy and interobserver variability of MRI screening in the detection of rupture and extracapsular silicone leakage. A prospective study included 107 women with 214 PIP implants who underwent explantation preceded by MRI. In 2013, two radiologists blinded for previous MRI findings or outcome at surgery, independently re-evaluated all MRI examinations. A structured protocol described the MRI findings. The ex vivo findings served as reference standard. In 208 of the 214 explanted prostheses, radiologists agreed independently about the condition of the implants. In five of the six cases they disagreed (2.6 %), but subsequently reached consensus. A sensitivity of 93 %, specificity of 93 %, positive predictive value of 77 % and negative predictive value of 98 % was found. The interobserver agreement was excellent (kappa value of 0.92). MRI has a high accuracy in diagnosing rupture in silicone breast implants. Considering the high kappa value of interobserver agreement, MRI appears to be a consistent diagnostic test. A simple, uniform classification, may improve communication between radiologist and plastic surgeon. (orig.)

  6. A 1-V 15 μW High-Accuracy Temperature Switch

    NARCIS (Netherlands)

    Schinkel, D.; Boer, de R.P.; Annema, A.J.; Tuijl, van A.J.M.

    2004-01-01

    A CMOS temperature switch with uncalibrated high accuracy is presented. The circuit is based on the classical CMOS bandgap reference structure, using parasitic PNPs and a PTAT multiplier. The circuit was designed in a standard digital 0.18 m CMOS process. The temperature switch has an in-designed hy

  7. The effect of pattern overlap on the accuracy of high resolution electron backscatter diffraction measurements

    Energy Technology Data Exchange (ETDEWEB)

    Tong, Vivian, E-mail: v.tong13@imperial.ac.uk [Department of Materials, Imperial College London, Prince Consort Road, London SW7 2AZ (United Kingdom); Jiang, Jun [Department of Materials, Imperial College London, Prince Consort Road, London SW7 2AZ (United Kingdom); Wilkinson, Angus J. [Department of Materials, University of Oxford, Parks Road, Oxford OX1 3PH (United Kingdom); Britton, T. Ben [Department of Materials, Imperial College London, Prince Consort Road, London SW7 2AZ (United Kingdom)

    2015-08-15

    High resolution, cross-correlation-based, electron backscatter diffraction (EBSD) measures the variation of elastic strains and lattice rotations from a reference state. Regions near grain boundaries are often of interest but overlap of patterns from the two grains could reduce accuracy of the cross-correlation analysis. To explore this concern, patterns from the interior of two grains have been mixed to simulate the interaction volume crossing a grain boundary so that the effect on the accuracy of the cross correlation results can be tested. It was found that the accuracy of HR-EBSD strain measurements performed in a FEG-SEM on zirconium remains good until the incident beam is less than 18 nm from a grain boundary. A simulated microstructure was used to measure how often pattern overlap occurs at any given EBSD step size, and a simple relation was found linking the probability of overlap with step size. - Highlights: • Pattern overlap occurs at grain boundaries and reduces HR-EBSD accuracy. • A test is devised to measure the accuracy of HR-EBSD in the presence of overlap. • High pass filters can sometimes, but not generally, improve HR-EBSD measurements. • Accuracy of HR-EBSD remains high until the reference pattern intensity is <72%. • 9% of points near a grain boundary will have significant error for 200nm step size in Zircaloy-4.

  8. High Accuracy Wavelength Calibration For A Scanning Visible Spectrometer

    Energy Technology Data Exchange (ETDEWEB)

    Filippo Scotti and Ronald Bell

    2010-07-29

    Spectroscopic applications for plasma velocity measurements often require wavelength accuracies ≤ 0.2Â. An automated calibration for a scanning spectrometer has been developed to achieve a high wavelength accuracy overr the visible spectrum, stable over time and environmental conditions, without the need to recalibrate after each grating movement. The method fits all relevant spectrometer paraameters using multiple calibration spectra. With a steping-motor controlled sine-drive, accuracies of ~0.025 Â have been demonstrated. With the addition of high resolution (0.075 aresec) optical encoder on the grading stage, greater precision (~0.005 Â) is possible, allowing absolute velocity measurements with ~0.3 km/s. This level of precision requires monitoring of atmospheric temperature and pressure and of grating bulk temperature to correct for changes in the refractive index of air and the groove density, respectively.

  9. DIPSY, a low-cost GPS application with high accuracy

    NARCIS (Netherlands)

    Heijden, W.F.M. van der

    1998-01-01

    To improve the control of unmanned aircraft flying out of visual range, the controller needs to be provided with realtime information about the position and behaviour of the drone during the flight. The position of the drone has to be presented with a relative high accuracy to obtain accurate flight

  10. DIPSY, a low-cost GPS application with high accuracy

    NARCIS (Netherlands)

    Heijden, W.F.M. van der

    1999-01-01

    To improve the control of unmanned aircraft flying out of visual range, the controller needs to be provided with real-time information about the position and behaviour of the drone during the flight. The position of the drone has to be presented with a relative high accuracy to obtain accurate lligh

  11. DIPSY, a low-cost GPS application with high accuracy

    NARCIS (Netherlands)

    Heijden, W.F.M. van der

    1999-01-01

    To improve the control of unmanned aircraft flying out of visual range, the controller needs to be provided with real-time information about the position and behaviour of the drone during the flight. The position of the drone has to be presented with a relative high accuracy to obtain accurate lligh

  12. DIPSY, a low-cost GPS application with high accuracy

    NARCIS (Netherlands)

    Heijden, W.F.M. van der

    1998-01-01

    To improve the control of unmanned aircraft flying out of visual range, the controller needs to be provided with realtime information about the position and behaviour of the drone during the flight. The position of the drone has to be presented with a relative high accuracy to obtain accurate flight

  13. DIPSY, a low-cost GPS application with high accuracy

    NARCIS (Netherlands)

    Heijden, W.F.M. van der

    1999-01-01

    To improve the control of unmanned aircraft flying out of visual range, the controller needs to be provided with real-time information about the position and behaviour of the drone during the flight. The position of the drone has to be presented with a relative high accuracy to obtain accurate

  14. Effectiveness of a reference accuracy strategy for peer-reviewed journal articles.

    Science.gov (United States)

    Speck, Kirsten E; St Pierre Schneider, Barbara

    2013-01-01

    Dissemination of information through peer-reviewed journal articles is an important requirement of success in academia. Despite the importance of publishing articles, about 25% to 45% of articles published in nursing journals have at least 1 reference error in the reference list. The authors discuss the implementation and outcomes of an internal copyeditor strategy aimed at reducing reference inaccuracy in faculty-authored journal articles.

  15. Reference List Accuracy in Social Work Journals: A Follow-Up Analysis

    Science.gov (United States)

    Mitchell-Williams, Missy T.; Skipper, Antonius D.; Alexander, Marvin C.; Wilks, Scott E.

    2017-01-01

    Purpose: Following up an "Research on Social Work Practice" article published a decade ago, this study aimed to examine reference error rates among five, widely circulated social work journals. Methods: A stratified random sample of references was selected from the year 2013 (N = 500, 100/journal). Each was verified against the original…

  16. Compensation of motion error in a high accuracy AFM

    Science.gov (United States)

    Cui, Yuguo; Arai, Yoshikazu; He, Gaofa; Asai, Takemi; Gao, Wei

    2008-10-01

    An atomic force microscope (AFM) system is used for large-area measurement with a spiral scanning strategy, which is composed of an air slide, an air spindle and a probe unit. The motion error which is brought from the air slide and the air spindle will increase with the increasing of the measurement area. Then the measurement accuracy will decrease. In order to achieve a high speed and high accuracy measurement, the probe scans along X-direction with constant height mode driven by the air slide, and at the same time, based on the change way of the motion error, it moves along Zdirection conducted by piezoactuator. According to the above method of error compensation, the profile measurement experiment of a micro-structured surface has been carried out. The experimental result shows that this method is effective for eliminating motion error, and it can achieve high speed and precision measurement of micro-structured surface.

  17. Accuracy Enhancement of Inertial Sensors Utilizing High Resolution Spectral Analysis

    Directory of Open Access Journals (Sweden)

    Michael Korenberg

    2012-08-01

    Full Text Available In both military and civilian applications, the inertial navigation system (INS and the global positioning system (GPS are two complementary technologies that can be integrated to provide reliable positioning and navigation information for land vehicles. The accuracy enhancement of INS sensors and the integration of INS with GPS are the subjects of widespread research. Wavelet de-noising of INS sensors has had limited success in removing the long-term (low-frequency inertial sensor errors. The primary objective of this research is to develop a novel inertial sensor accuracy enhancement technique that can remove both short-term and long-term error components from inertial sensor measurements prior to INS mechanization and INS/GPS integration. A high resolution spectral analysis technique called the fast orthogonal search (FOS algorithm is used to accurately model the low frequency range of the spectrum, which includes the vehicle motion dynamics and inertial sensor errors. FOS models the spectral components with the most energy first and uses an adaptive threshold to stop adding frequency terms when fitting a term does not reduce the mean squared error more than fitting white noise. The proposed method was developed, tested and validated through road test experiments involving both low-end tactical grade and low cost MEMS-based inertial systems. The results demonstrate that in most cases the position accuracy during GPS outages using FOS de-noised data is superior to the position accuracy using wavelet de-noising.

  18. Why is a high accuracy needed in dosimetry. [Radiotherapy

    Energy Technology Data Exchange (ETDEWEB)

    Lanzl, L.H.

    1976-01-01

    Dose and exposure intercomparisons on a national or international basis have become an important component of quality assurance in the practice of good radiotherapy. A high degree of accuracy of ..gamma.. and x radiation dosimetry is essential in our international society, where medical information is so readily exchanged and used. The value of accurate dosimetry lies mainly in the avoidance of complications in normal tissue and an optimal degree of tumor control.

  19. Navigation message designing with high accuracy for NAV

    Institute of Scientific and Technical Information of China (English)

    Wang Luxiao; Huang Zhigang; Zhao Yun

    2014-01-01

    Navigation message designing with high accuracy guarantee is the key to efficient navi-gation message distribution in the global navigation satellite system (GNSS). Developing high accu-racy-aware navigation message designing algorithms is an important topic. This paper investigates the high-accuracy navigation message designing problem with the message structure unchanged. The contributions made in this paper include a heuristic that employs the concept of the estimated range deviation (ERD) to improve the existing well-known navigation message on L1 frequency (NAV) of global positioning system (GPS) for good accuracy service; a numerical analysis approximation method (NAAM) to evaluate the range error due to truncation (RET) of different navigation messages; and a basic positioning parameters designing algorithm in the limited space allocation. Based on the predicted ultra-rapid data from the ultra-rapid data from the international GPS service for geodynamic (IGU), ERDs are generated in real time for error correction. Simulations show that the algorithms developed in this paper are general and flexible, and thus are applicable to NAV improvement and other navigation message designs.

  20. High Accuracy, Miniature Pressure Sensor for Very High Temperatures Project

    Data.gov (United States)

    National Aeronautics and Space Administration — SiWave proposes to develop a compact, low-cost MEMS-based pressure sensor for very high temperatures and low pressures in hypersonic wind tunnels. Most currently...

  1. A Meta-Analysis of Typhoid Diagnostic Accuracy Studies: A Recommendation to Adopt a Standardized Composite Reference.

    Directory of Open Access Journals (Sweden)

    Helen L Storey

    Full Text Available Novel typhoid diagnostics currently under development have the potential to improve clinical care, surveillance, and the disease burden estimates that support vaccine introduction. Blood culture is most often used as the reference method to evaluate the accuracy of new typhoid tests; however, it is recognized to be an imperfect gold standard. If no single gold standard test exists, use of a composite reference standard (CRS can improve estimation of diagnostic accuracy. Numerous studies have used a CRS to evaluate new typhoid diagnostics; however, there is no consensus on an appropriate CRS. In order to evaluate existing tests for use as a reference test or inclusion in a CRS, we performed a systematic review of the typhoid literature to include all index/reference test combinations observed. We described the landscape of comparisons performed, showed results of a meta-analysis on the accuracy of the more common combinations, and evaluated sources of variability based on study quality. This wide-ranging meta-analysis suggests that no single test has sufficiently good performance but some existing diagnostics may be useful as part of a CRS. Additionally, based on findings from the meta-analysis and a constructed numerical example demonstrating the use of CRS, we proposed necessary criteria and potential components of a typhoid CRS to guide future recommendations. Agreement and adoption by all investigators of a standardized CRS is requisite, and would improve comparison of new diagnostics across independent studies, leading to the identification of a better reference test and improved confidence in prevalence estimates.

  2. Study on High Accuracy Topographic Mapping via UAV-based Images

    Science.gov (United States)

    Chi, Yun-Yao; Lee, Ya-Fen; Tsai, Shang-En

    2016-10-01

    Unmanned aerial vehicle (UAV) provides a promising tool for the acquisition of such multi-temporal aerial stereo photos and high-resolution digital surface models. Recently, the flight of UAVs operates with high degrees of autonomy by the global position system and onboard digit camera and computer. The UAV-based mapping can be obtained faster and cheaper, but its accuracy is anxious. This paper aims to identify the integration ability of high accuracy topographic map via the image of quad-rotors UAV and ground control points (GCPs). The living survey data is collected in the Errn river basins area in Tainan, Taiwan. The high accuracy UAV-based topographic in the study area is calibrated by the local coordinate of GCPs using the total station with the accuracy less than 1/2000. The comparison results show the accuracy of UAV-based topographic is accepted by overlapping. The results can be a reference for the practice works of mapping survey in earth.

  3. High Accuracy Monocular SFM and Scale Correction for Autonomous Driving.

    Science.gov (United States)

    Song, Shiyu; Chandraker, Manmohan; Guest, Clark C

    2016-04-01

    We present a real-time monocular visual odometry system that achieves high accuracy in real-world autonomous driving applications. First, we demonstrate robust monocular SFM that exploits multithreading to handle driving scenes with large motions and rapidly changing imagery. To correct for scale drift, we use known height of the camera from the ground plane. Our second contribution is a novel data-driven mechanism for cue combination that allows highly accurate ground plane estimation by adapting observation covariances of multiple cues, such as sparse feature matching and dense inter-frame stereo, based on their relative confidences inferred from visual data on a per-frame basis. Finally, we demonstrate extensive benchmark performance and comparisons on the challenging KITTI dataset, achieving accuracy comparable to stereo and exceeding prior monocular systems. Our SFM system is optimized to output pose within 50 ms in the worst case, while average case operation is over 30 fps. Our framework also significantly boosts the accuracy of applications like object localization that rely on the ground plane.

  4. Accuracy of the International Terrestrial Reference Frame origin and Earth expansion

    NARCIS (Netherlands)

    Wu, X.; Collilieux, X.; Altamimi, Z.; Vermeersen, L.L.A.; Gross, R.S.; Fukumori, I.

    2011-01-01

    The International Terrestrial Reference Frame (ITRF) is a fundamental datum for high‐precision orbit tracking, navigation, and global change monitoring. Accurately realizing and maintaining ITRF origin at the mean Earth system center of mass (CM) is critical to surface and spacecraft based geodetic

  5. Navigation Facility for High Accuracy Offline Trajectory and Attitude Estimation in Airborne Applications

    Directory of Open Access Journals (Sweden)

    A. Renga

    2013-01-01

    Full Text Available The paper focuses on a navigation facility, relying on commercial-off-the-shelf (COTS technology, developed to generate high-accuracy attitude and trajectory measurements in postprocessing. Target performance is cm-level positioning with tenth of degree attitude accuracy. The facility is based on the concept of GPS-aided inertial navigation but comprises carrier-phase differential GPS (CDGPS processing and attitude estimation based on multiantenna GPS configurations. Expected applications of the system include: (a performance assessment of integrated navigation systems, developed for general aviation aircraft and medium size unmanned aircraft systems (UAS; (b generation of reference measurements to evaluate the flight performance of airborne sensors (e.g., radar or laser; and (c generation of reference trajectory and attitude for improving imaging quality of airborne remote sensing data. The paper describes system architecture, selected algorithms for data processing and integration, and theoretical performance evaluation. Experimental results are also presented confirming the effectiveness of the implemented approach.

  6. High accuracy and visibility-consistent dense multiview stereo.

    Science.gov (United States)

    Vu, Hoang-Hiep; Labatut, Patrick; Pons, Jean-Philippe; Keriven, Renaud

    2012-05-01

    Since the initial comparison of Seitz et al., the accuracy of dense multiview stereovision methods has been increasing steadily. A number of limitations, however, make most of these methods not suitable to outdoor scenes taken under uncontrolled imaging conditions. The present work consists of a complete dense multiview stereo pipeline which circumvents these limitations, being able to handle large-scale scenes without sacrificing accuracy. Highly detailed reconstructions are produced within very reasonable time thanks to two key stages in our pipeline: a minimum s-t cut optimization over an adaptive domain that robustly and efficiently filters a quasidense point cloud from outliers and reconstructs an initial surface by integrating visibility constraints, followed by a mesh-based variational refinement that captures small details, smartly handling photo-consistency, regularization, and adaptive resolution. The pipeline has been tested over a wide range of scenes: from classic compact objects taken in a laboratory setting, to outdoor architectural scenes, landscapes, and cultural heritage sites. The accuracy of its reconstructions has also been measured on the dense multiview benchmark proposed by Strecha et al., showing the results to compare more than favorably with the current state-of-the-art methods.

  7. High Accuracy Near-infrared Imaging Polarimetry with NICMOS

    CERN Document Server

    Batcheldor, D; Hines, D C; Schmidt, G D; Axon, D J; Robinson, A; Sparks, W; Tadhunter, C

    2008-01-01

    The findings of a nine orbit calibration plan carried out during HST Cycle 15, to fully determine the NICMOS camera 2 (2.0 micron) polarization calibration to high accuracy, are reported. Recently Ueta et al. and Batcheldor et al. have suggested that NICMOS possesses a residual instrumental polarization at a level of 1.2-1.5%. This would completely inhibit the data reduction in a number of GO programs, and hamper the ability of the instrument to perform high accuracy polarimetry. We obtained polarimetric calibration observations of three polarimetric standards at three spacecraft roll angles separated by ~60deg. Combined with archival data, these observations were used to characterize the residual instrumental polarization in order for NICMOS to reach its full potential of accurate imaging polarimetry at p~1%. Using these data, we place an 0.6% upper limit on the instrumental polarization and calculate values of the parallel transmission coefficients that reproduce the ground-based results for the polarimetri...

  8. High-accuracy mass spectrometry for fundamental studies.

    Science.gov (United States)

    Kluge, H-Jürgen

    2010-01-01

    Mass spectrometry for fundamental studies in metrology and atomic, nuclear and particle physics requires extreme sensitivity and efficiency as well as ultimate resolving power and accuracy. An overview will be given on the global status of high-accuracy mass spectrometry for fundamental physics and metrology. Three quite different examples of modern mass spectrometric experiments in physics are presented: (i) the retardation spectrometer KATRIN at the Forschungszentrum Karlsruhe, employing electrostatic filtering in combination with magnetic-adiabatic collimation-the biggest mass spectrometer for determining the smallest mass, i.e. the mass of the electron anti-neutrino, (ii) the Experimental Cooler-Storage Ring at GSI-a mass spectrometer of medium size, relative to other accelerators, for determining medium-heavy masses and (iii) the Penning trap facility, SHIPTRAP, at GSI-the smallest mass spectrometer for determining the heaviest masses, those of super-heavy elements. Finally, a short view into the future will address the GSI project HITRAP at GSI for fundamental studies with highly-charged ions.

  9. Researching the technology of high-accuracy camshaft measurement

    Science.gov (United States)

    Chen, Wei; Chen, Yong-Le; Wang, Hong; Liao, Hai-Yang

    1996-10-01

    This paper states the cam's data processing algorithm in detail in high accurate camshaft measurement system. It contains: 1) using minimum error of curve symmetry to seek the center position of the key slot; 2) Calculating the minimum error by cam's curve in theory to search top area; 3) According to cam's tolerance E(i) function and minimum angle error at cam top, seeking the best position of cam top and getting the best angle value and error curve. The algorithm is suitable for measuring all kinds of symmetry or asymmetry cam, and plain push-rod or spherical push-rod cam, for example, bus camshaft, car camshaft, motor camshaft, etc. Using the algorithm, high accuracy measurement can be achieved.

  10. Read-only high accuracy volume holographic optical correlator

    Science.gov (United States)

    Zhao, Tian; Li, Jingming; Cao, Liangcai; He, Qingsheng; Jin, Guofan

    2011-10-01

    A read-only volume holographic correlator (VHC) is proposed. After the recording of all of the correlation database pages by angular multiplexing, a stand-alone read-only high accuracy VHC will be separated from the VHC recording facilities which include the high-power laser and the angular multiplexing system. The stand-alone VHC has its own low power readout laser and very compact and simple structure. Since there are two lasers that are employed for recording and readout, respectively, the optical alignment tolerance of the laser illumination on the SLM is very sensitive. The twodimensional angular tolerance is analyzed based on the theoretical model of the volume holographic correlator. The experimental demonstration of the proposed read-only VHC is introduced and discussed.

  11. Spatial augmented reality based high accuracy human face projection

    Science.gov (United States)

    Li, Dong; Xie, Jinghui; Li, Yufeng; Weng, Dongdong; Liu, Yue

    2015-08-01

    This paper discusses the imaging principles and the technical difficulties of spatial augmented reality based human face projection. A novel geometry correction method is proposed to realize fast, high-accuracy face model projection. Using a depth camera to reconstruct the projected object, the relative position from the rendered model to the projector can be accessed and the initial projection image is generated. Then the projected image is distorted by using Bezier interpolation to guarantee that the projected texture matches with the object surface. The proposed method is under a simple process flow and can achieve high perception registration of virtual and real object. In addition, this method has a good performance in the condition that the reconstructed model is not exactly same with the rendered virtual model which extends its application area in the spatial augmented reality based human face projection.

  12. Primary care REFerral for EchocaRdiogram (REFER) in heart failure: a diagnostic accuracy study

    Science.gov (United States)

    Taylor, Clare J; Roalfe, Andrea K; Iles, Rachel; Hobbs, FD Richard; Barton, P; Deeks, J; McCahon, D; Cowie, MR; Sutton, G; Davis, RC; Mant, J; McDonagh, T; Tait, L

    2017-01-01

    Background Symptoms of breathlessness, fatigue, and ankle swelling are common in general practice but deciding which patients are likely to have heart failure is challenging. Aim To evaluate the performance of a clinical decision rule (CDR), with or without N-Terminal pro-B type natriuretic peptide (NT-proBNP) assay, for identifying heart failure. Design and setting Prospective, observational, diagnostic validation study of patients aged >55 years, presenting with shortness of breath, lethargy, or ankle oedema, from 28 general practices in England. Method The outcome was test performance of the CDR and natriuretic peptide test in determining a diagnosis of heart failure. The reference standard was an expert consensus panel of three cardiologists. Results Three hundred and four participants were recruited, with 104 (34.2%; 95% confidence interval [CI] = 28.9 to 39.8) having a confirmed diagnosis of heart failure. The CDR+NT-proBNP had a sensitivity of 90.4% (95% CI = 83.0 to 95.3) and specificity 45.5% (95% CI = 38.5 to 52.7). NT-proBNP level alone with a cut-off need to be revised. PMID:27919937

  13. Diagnostic accuracy of MRI in adults with suspect brachial plexus lesions: A multicentre retrospective study with surgical findings and clinical follow-up as reference standard

    Energy Technology Data Exchange (ETDEWEB)

    Tagliafico, Alberto, E-mail: alberto.tagliafico@unige.it [Institute of Anatomy, Department of Experimental Medicine, University of Genoa, Largo Rosanna Benzi 8, 16132 Genoa (Italy); Succio, Giulia; Serafini, Giovanni [Department of Radiology, Santa Corona Hospital, Pietra Ligure, Italy via XXV Aprile, 38- Pietra Ligure, 17027 Savona (Italy); Martinoli, Carlo [Radiology Department, DISC, Università di Genova, Largo Rosanna Benzi 8, 16138 Genova (Italy)

    2012-10-15

    Objective: To evaluate brachial plexus MRI accuracy with surgical findings and clinical follow-up as reference standard in a large multicentre study. Materials and methods: The research was approved by the Institutional Review Boards, and all patients provided their written informed consent. A multicentre retrospective trial that included three centres was performed between March 2006 and April 2011. A total of 157 patients (men/women: 81/76; age range, 18–84 years) were evaluated: surgical findings and clinical follow-up of at least 12 months were used as the reference standard. MR imaging was performed with different equipment at 1.5 T and 3.0 T. The patient group was divided in five subgroups: mass lesion, traumatic injury, entrapment syndromes, post-treatment evaluation, and other. Sensitivity, specificity with 95% confidence intervals (CIs), positive predictive value (PPV), pre-test-probability (the prevalence), negative predictive value (NPV), pre- and post-test odds (OR), likelihood ratio for positive results (LH+), likelihood ratio for negative results (LH−), accuracy and post-test probability (post-P) were reported on a per-patient basis. Results: The overall sensitivity and specificity with 95% CIs were: 0.810/0.914; (0.697–0.904). Overall PPV, pre-test probability, NPV, LH+, LH−, and accuracy: 0.823, 0.331, 0.905, 9.432, 0.210, 0.878. Conclusions: The overall diagnostic accuracy of brachial plexus MRI calculated on a per-patient base is relatively high. The specificity of brachial plexus MRI in patients suspected of having a space-occupying mass is very high. The sensitivity is also high, but there are false-positive interpretations as well.

  14. A high precision high PSRR bandgap reference with thermal hysteresis protection

    Energy Technology Data Exchange (ETDEWEB)

    Yang Yintang; Li Yani; Zhu Zhangming, E-mail: yanili@mail.xidian.edu.c [Key Laboratory of Wide Band-Gap Semiconductor Materials and Devices of the Ministry of Education, Institute of Microelectronics, Xidian University, Xi' an 710071 (China)

    2010-09-15

    To meet the accuracy requirement for the bandgap voltage reference by the increasing data conversion precision of integrated circuits, a high-order curvature-compensated bandgap voltage reference is presented employing the characteristic of bipolar transistor current gain exponentially changing with temperature variations. In addition, an over-temperature protection circuit with a thermal hysteresis function to prevent thermal oscillation is proposed. Based on the CSMC 0.5 {mu}m 20 V BCD process, the designed circuit is implemented; the active die area is 0.17 x 0.20 mm{sup 2}. Simulation and testing results show that the temperature coefficient is 13.7ppm/K with temperature ranging from -40 to 150 {sup 0}C, the power supply rejection ratio is -98.2 dB, the line regulation is 0.3 mV/V, and the power consumption is only 0.38 mW. The proposed bandgap voltage reference has good characteristics such as small area, low power consumption, good temperature stability, high power supply rejection ratio, as well as low line regulation. This circuit can effectively prevent thermal oscillation and is suitable for on-chip voltage reference in high precision analog, digital and mixed systems. (semiconductor integrated circuits)

  15. SEMICONDUCTOR INTEGRATED CIRCUITS: A high precision high PSRR bandgap reference with thermal hysteresis protection

    Science.gov (United States)

    Yintang, Yang; Yani, Li; Zhangming, Zhu

    2010-09-01

    To meet the accuracy requirement for the bandgap voltage reference by the increasing data conversion precision of integrated circuits, a high-order curvature-compensated bandgap voltage reference is presented employing the characteristic of bipolar transistor current gain exponentially changing with temperature variations. In addition, an over-temperature protection circuit with a thermal hysteresis function to prevent thermal oscillation is proposed. Based on the CSMC 0.5 μm 20 V BCD process, the designed circuit is implemented; the active die area is 0.17 × 0.20 mm2. Simulation and testing results show that the temperature coefficient is 13.7ppm/K with temperature ranging from -40 to 150 °C, the power supply rejection ratio is -98.2 dB, the line regulation is 0.3 mV/V, and the power consumption is only 0.38 mW. The proposed bandgap voltage reference has good characteristics such as small area, low power consumption, good temperature stability, high power supply rejection ratio, as well as low line regulation. This circuit can effectively prevent thermal oscillation and is suitable for on-chip voltage reference in high precision analog, digital and mixed systems.

  16. Literature survey of high-impact journals revealed reporting weaknesses in abstracts of diagnostic accuracy studies.

    Science.gov (United States)

    Korevaar, Daniël A; Cohen, Jérémie F; Hooft, Lotty; Bossuyt, Patrick M M

    2015-06-01

    Informative journal abstracts are crucial for the identification and initial appraisal of studies. We aimed to evaluate the informativeness of abstracts of diagnostic accuracy studies. PubMed was searched for reports of studies that had evaluated the diagnostic accuracy of a test against a clinical reference standard, published in 12 high-impact journals in 2012. Two reviewers independently evaluated the information contained in included abstracts using 21 items deemed important based on published guidance for adequate reporting and study quality assessment. We included 103 abstracts. Crucial information on study population, setting, patient sampling, and blinding as well as confidence intervals around accuracy estimates were reported in items per abstract was 10.1 of 21 (standard deviation 2.2). The mean number of reported items was significantly lower for multiple-gate (case-control type) studies, in reports in specialty journals, and for studies with smaller sample sizes and lower abstract word counts. No significant differences were found between studies evaluating different types of tests. Many abstracts of diagnostic accuracy study reports in high-impact journals are insufficiently informative. Developing guidelines for such abstracts could help the transparency and completeness of reporting. Copyright © 2015 Elsevier Inc. All rights reserved.

  17. Correlation Analysis Combined with a Floating Reference Measurement to Improve the Prediction Accuracy of Glucose in Scattering Media.

    Science.gov (United States)

    Min, Xiaolin; Liu, Rong; Fu, Bo; Xu, Kexin

    2017-09-01

    Noninvasive sensing of blood glucose based on near-infrared (NIR) spectroscopy is a research hotspot in the biomedical field. However, its accuracy is severely limited by the weak specific signal of glucose and the strong background variations caused by other constituents in the blood, the measuring instrument, and the environment. In this paper, special source-detector distances, defined as the floating reference position, are used to conduct relative measurements and correct for background variations. These floating reference positions are chosen so that the diffuse reflectance is not sensitive to the change in glucose concentration due to the combined effects of absorption and scattering. Nine 10% intralipid samples with glucose concentrations in the range of 1000-5000 mg dL(-1) at an interval of 500 mg dL(-1) were prepared. Using a custom-built, continuously moving, spatially resolving, double-fiber measurement system with a superluminescent diode (SLD) as the light source, the diffuse reflectance of intralipid samples containing glucose under different source-detector distances (0.2-5 mm, with intervals of 0.2 mm) were collected. Then, a correlation analysis between the spectra and the glucose concentration was carried out to determine the floating reference position and the optimal measuring position. The signal in the floating reference position was used to correct the background variation because it contains the same systematic drift and interference as the signal in the optimal measuring position. The results showed that the correlation between the diffuse reflectance and the glucose concentration was increased significantly compared with traditional correction by subtracting the nearest spectrum of pure 10% intralipid solution. The correlation between the diffuse reflectance and the concentration of glucose is significantly increased, which indicated that the combination of the correlation analysis and a floating reference is able to eliminate

  18. High accuracy mantle convection simulation through modern numerical methods

    KAUST Repository

    Kronbichler, Martin

    2012-08-21

    Numerical simulation of the processes in the Earth\\'s mantle is a key piece in understanding its dynamics, composition, history and interaction with the lithosphere and the Earth\\'s core. However, doing so presents many practical difficulties related to the numerical methods that can accurately represent these processes at relevant scales. This paper presents an overview of the state of the art in algorithms for high-Rayleigh number flows such as those in the Earth\\'s mantle, and discusses their implementation in the Open Source code Aspect (Advanced Solver for Problems in Earth\\'s ConvecTion). Specifically, we show how an interconnected set of methods for adaptive mesh refinement (AMR), higher order spatial and temporal discretizations, advection stabilization and efficient linear solvers can provide high accuracy at a numerical cost unachievable with traditional methods, and how these methods can be designed in a way so that they scale to large numbers of processors on compute clusters. Aspect relies on the numerical software packages deal.II and Trilinos, enabling us to focus on high level code and keeping our implementation compact. We present results from validation tests using widely used benchmarks for our code, as well as scaling results from parallel runs. © 2012 The Authors Geophysical Journal International © 2012 RAS.

  19. Computing the Free Energy Barriers for Less by Sampling with a Coarse Reference Potential while Retaining Accuracy of the Target Fine Model.

    Science.gov (United States)

    Plotnikov, Nikolay V

    2014-08-12

    Proposed in this contribution is a protocol for calculating fine-physics (e.g., ab initio QM/MM) free-energy surfaces at a high level of accuracy locally (e.g., only at reactants and at the transition state for computing the activation barrier) from targeted fine-physics sampling and extensive exploratory coarse-physics sampling. The full free-energy surface is still computed but at a lower level of accuracy from coarse-physics sampling. The method is analytically derived in terms of the umbrella sampling and the free-energy perturbation methods which are combined with the thermodynamic cycle and the targeted sampling strategy of the paradynamics approach. The algorithm starts by computing low-accuracy fine-physics free-energy surfaces from the coarse-physics sampling in order to identify the reaction path and to select regions for targeted sampling. Thus, the algorithm does not rely on the coarse-physics minimum free-energy reaction path. Next, segments of high-accuracy free-energy surface are computed locally at selected regions from the targeted fine-physics sampling and are positioned relative to the coarse-physics free-energy shifts. The positioning is done by averaging the free-energy perturbations computed with multistep linear response approximation method. This method is analytically shown to provide results of the thermodynamic integration and the free-energy interpolation methods, while being extremely simple in implementation. Incorporating the metadynamics sampling to the algorithm is also briefly outlined. The application is demonstrated by calculating the B3LYP//6-31G*/MM free-energy barrier for an enzymatic reaction using a semiempirical PM6/MM reference potential. These modifications allow computing the activation free energies at a significantly reduced computational cost but at the same level of accuracy compared to computing full potential of mean force.

  20. Monitoring techniques for high accuracy interference fit assembly processes

    Science.gov (United States)

    Liuti, A.; Vedugo, F. Rodriguez; Paone, N.; Ungaro, C.

    2016-06-01

    In the automotive industry, there are many assembly processes that require a high geometric accuracy, in the micrometer range; generally open-loop controllers cannot meet these requirements. This results in an increased defect rate and high production costs. This paper presents an experimental study of interference fit process, aimed to evaluate the aspects which have the most impact on the uncertainty in the final positioning. The press-fitting process considered, consists in a press machine operating with a piezoelectric actuator to press a plug into a sleeve. Plug and sleeve are designed and machined to obtain a known interference fit. Differential displacement and velocity measurements of the plug with respect to the sleeve are measured by a fiber optic differential laser Doppler vibrometer. Different driving signals of the piezo actuator allow to have an insight into the differences between a linear and a pulsating press action. The paper highlights how the press-fit assembly process is characterized by two main phases: the first is an elastic deformation of the plug and sleeve, which produces a reversible displacement, the second is a sliding of the plug with respect to the sleeve, which results in an irreversible displacement and finally realizes the assembly. The simultaneous measurements of the displacement and the force have permitted to define characteristic features in the signal useful to identify the start of the irreversible movement. These indicators could be used to develop a control logic in a press assembly process.

  1. High-accuracy Subdaily ERPs from the IGS

    Science.gov (United States)

    Ray, J. R.; Griffiths, J.

    2012-04-01

    Since November 2000 the International GNSS Service (IGS) has published Ultra-rapid (IGU) products for near real-time (RT) and true real-time applications. They include satellite orbits and clocks, as well as Earth rotation parameters (ERPs) for a sliding 48-hr period. The first day of each update is based on the most recent GPS and GLONASS observational data from the IGS hourly tracking network. At the time of release, these observed products have an initial latency of 3 hr. The second day of each update consists of predictions. So the predictions between about 3 and 9 hr into the second half are relevant for true RT uses. Originally updated twice daily, the IGU products since April 2004 have been issued every 6 hr, at 3, 9, 15, and 21 UTC. Up to seven Analysis Centers (ACs) contribute to the IGU combinations. Two sets of ERPs are published with each IGU update, observed values at the middle epoch of the first half and predicted values at the middle epoch of the second half. The latency of the near RT ERPs is 15 hr while the predicted ERPs, based on projections of each AC's most recent determinations, are issued 9 hr ahead of their reference epoch. While IGU ERPs are issued every 6 hr, each set represents an integrated estimate over the surrounding 24 hr. So successive values are temporally correlated with about 75% of the data being common; this fact should be taken into account in user assimilations. To evaluate the accuracy of these near RT and predicted ERPs, they have been compared to the IGS Final ERPs, available about 11 to 17 d after data collection. The IGU products improved dramatically in the earlier years but since about 2008.0 the performance has been stable and excellent. During the last three years, RMS differences for the observed IGU ERPs have been about 0.036 mas and 0.0101 ms for each polar motion component and LOD respectively. (The internal precision of the reference IGS ERPs over the same period is about 0.016 mas for polar motion and 0

  2. Determination of UAV position using high accuracy navigation platform

    Directory of Open Access Journals (Sweden)

    Ireneusz Kubicki

    2016-07-01

    Full Text Available The choice of navigation system for mini UAV is very important because of its application and exploitation, particularly when the installed on it a synthetic aperture radar requires highly precise information about an object’s position. The presented exemplary solution of such a system draws attention to the possible problems associated with the use of appropriate technology, sensors, and devices or with a complete navigation system. The position and spatial orientation errors of the measurement platform influence on the obtained SAR imaging. Both, turbulences and maneuvers performed during flight cause the changes in the position of the airborne object resulting in deterioration or lack of images from SAR. Consequently, it is necessary to perform operations for reducing or eliminating the impact of the sensors’ errors on the UAV position accuracy. You need to look for compromise solutions between newer better technologies and in the field of software. Keywords: navigation systems, unmanned aerial vehicles, sensors integration

  3. An administrative data validation study of the accuracy of algorithms for identifying rheumatoid arthritis: the influence of the reference standard on algorithm performance.

    Science.gov (United States)

    Widdifield, Jessica; Bombardier, Claire; Bernatsky, Sasha; Paterson, J Michael; Green, Diane; Young, Jacqueline; Ivers, Noah; Butt, Debra A; Jaakkimainen, R Liisa; Thorne, J Carter; Tu, Karen

    2014-06-23

    We have previously validated administrative data algorithms to identify patients with rheumatoid arthritis (RA) using rheumatology clinic records as the reference standard. Here we reassessed the accuracy of the algorithms using primary care records as the reference standard. We performed a retrospective chart abstraction study using a random sample of 7500 adult patients under the care of 83 family physicians contributing to the Electronic Medical Record Administrative data Linked Database (EMRALD) in Ontario, Canada. Using physician-reported diagnoses as the reference standard, we computed and compared the sensitivity, specificity, and predictive values for over 100 administrative data algorithms for RA case ascertainment. We identified 69 patients with RA for a lifetime RA prevalence of 0.9%. All algorithms had excellent specificity (>97%). However, sensitivity varied (75-90%) among physician billing algorithms. Despite the low prevalence of RA, most algorithms had adequate positive predictive value (PPV; 51-83%). The algorithm of "[1 hospitalization RA diagnosis code] or [3 physician RA diagnosis codes with ≥1 by a specialist over 2 years]" had a sensitivity of 78% (95% CI 69-88), specificity of 100% (95% CI 100-100), PPV of 78% (95% CI 69-88) and NPV of 100% (95% CI 100-100). Administrative data algorithms for detecting RA patients achieved a high degree of accuracy amongst the general population. However, results varied slightly from our previous report, which can be attributed to differences in the reference standards with respect to disease prevalence, spectrum of disease, and type of comparator group.

  4. Impacts of both reference population size and inclusion of a residual polygenic effect on the accuracy of genomic prediction

    Directory of Open Access Journals (Sweden)

    Rensing Stephan

    2011-05-01

    Full Text Available Abstract Background The purpose of this work was to study the impact of both the size of genomic reference populations and the inclusion of a residual polygenic effect on dairy cattle genetic evaluations enhanced with genomic information. Methods Direct genomic values were estimated for German Holstein cattle with a genomic BLUP model including a residual polygenic effect. A total of 17,429 genotyped Holstein bulls were evaluated using the phenotypes of 44 traits. The Interbull genomic validation test was implemented to investigate how the inclusion of a residual polygenic effect impacted genomic estimated breeding values. Results As the number of reference bulls increased, both the variance of the estimates of single nucleotide polymorphism effects and the reliability of the direct genomic values of selection candidates increased. Fitting a residual polygenic effect in the model resulted in less biased genome-enhanced breeding values and decreased the correlation between direct genomic values and estimated breeding values of sires in the reference population. Conclusions Genetic evaluation of dairy cattle enhanced with genomic information is highly effective in increasing reliability, as well as using large genomic reference populations. We found that fitting a residual polygenic effect reduced the bias in genome-enhanced breeding values, decreased the correlation between direct genomic values and sire's estimated breeding values and made genome-enhanced breeding values more consistent in mean and variance as is the case for pedigree-based estimated breeding values.

  5. Key technologies for high-accuracy large mesh antenna reflectors

    Science.gov (United States)

    Meguro, Akira; Harada, Satoshi; Watanabe, Mitsunobu

    2003-12-01

    Nippon Telephone and Telegram Corporation (NTT) continues to develop the modular mesh-type deployable antenna. Antenna diameter can be changed from 5 m to about 20 m by changing the number of modules used with surface accuracy better than 2.4 mm RMS (including all error factors) with sufficient deployment reliability. Key technologies are the antenna's structural design, the deployment mechanism, the design tool, the analysis tool, and modularized testing/evaluation methods. This paper describes our beam steering mechanism. Tests show that it yields a beam pointing accuracy of better than 0.1°. Based on the S-band modular mesh antenna reflector, the surface accuracy degradation factors that must be considered in designing the new antenna are partially identified. The influence of modular connection errors on surface accuracy is quantitatively estimated. Our analysis tool SPADE is extended to include the addition of joint gaps. The addition of gaps allows non-linear vibration characteristics due to gapping in deployment hinges to be calculated. We intend to design a new type of mesh antenna reflector. Our new goal is an antenna for Ku or Ka band satellite communication. For this mission, the surface shape must be 5 times more accurate than is required for an S-band antenna.

  6. High Accuracy and Real-Time Gated Viewing Laser Radar

    Institute of Scientific and Technical Information of China (English)

    Dong Li; Hua-Jun Yang; Shan-Pei Zhou

    2011-01-01

    A gated viewing laser radar has an excellent performance in underwater low light level imaging,and it also provides a viable solution to inhibit backscattering.In this paper,a gated viewing imaging system according to the demand for real-time imaging is presented,and then the simulation is used to analyze the performance of the real-time gated viewing system.The range accuracy performance is limited by the slice number,the width of gate,the delay time step,the initial delay time,as well as the system noise and atmospheric turbulence.The simulation results indicate that the highest range accuracy can be achieved when the system works with the optimal parameters.Finally,how to choose the optimal parameters has been researched.

  7. High Accuracy Attitude Control of a Spacecraft Using Feedback Linearization

    Science.gov (United States)

    1992-05-01

    and Spacecraft Body from Gyro Measurements ......... .................................. 119 D.2 An Approximation to Exact Linearization using IPSRU...31 2-4 Attitude Determination and Control System Architecture ................. 33 3-1 Exact Linearization Using Nonlinear Feedback...though basic techniques were adapted from recent references on the use of exact linearization (such as [8] and [27]), the specific control approach

  8. High Accuracy Thermal Expansion Measurement at Cryogenic Temperatures

    Science.gov (United States)

    Tucker, Jim; Despit, Gregory; Stallcup, Michael; Presson, Joan; Nein, Max

    2003-01-01

    A new, interferometer-based system for measuring thermal expansion to an absolute accuracy of 20 ppb or better at cryogenic temperatures has been developed. Data from NIST Copper SRM 736 measured from room temperature to 15 K will be presented along with data from many other materials including beryllium, ULE, Zerodur, and composite materials. Particular attention will be given to a study by the Space Optics Manufacturing Technology Center (SOMTC) investigating the variability of ULE and beryllium materials used in the AMSD program Approximately 20 samples of each material, tested from room temperature to below 30 K are compared as a function of billet location.

  9. High-Accuracy Programmable Timing Generator with Wide-Range Tuning Capability

    Directory of Open Access Journals (Sweden)

    Ting-Li Chu

    2013-01-01

    Full Text Available In this paper, a high-accuracy programmable timing generator with wide-range tuning capability is proposed. With the aid of dual delay-locked loop (DLL, both of the coarse- and fine-tuning mechanisms are operated in precise closed-loop scheme to lessen the effects of the ambient variations. The timing generator can provide sub-gate resolution and instantaneous switching capability. The circuit is implemented and simulated in TSMC 0.18 μm 1P6M technology. The test chip area occupies 1.9 mm2. The reference clock cycle can be divided into 128 bins by interpolation to obtain 14 ps resolution with the clock rate at 550 MHz. The INL and DNL are within −0.21~+0.78 and −0.27~+0.43 LSB, respectively.

  10. Design of a high linearity and high gain accuracy analog baseband circuit for DAB receiver

    Science.gov (United States)

    Li, Ma; Zhigong, Wang; Jian, Xu; Yiqiang, Wu; Junliang, Wang; Mi, Tian; Jianping, Chen

    2015-02-01

    An analog baseband circuit of high linearity and high gain accuracy for a digital audio broadcasting receiver is implemented in a 0.18-μm RFCMOS process. The circuit comprises a 3rd-order active-RC complex filter (CF) and a programmable gain amplifier (PGA). An automatic tuning circuit is also designed to tune the CF's pass band. Instead of the class-A fully differential operational amplifier (FDOPA) adopted in the conventional CF and PGA design, a class-AB FDOPA is specially employed in this circuit to achieve a higher linearity and gain accuracy for its large current swing capability with lower static current consumption. In the PGA circuit, a novel DC offset cancellation technique based on the MOS resistor is introduced to reduce the settling time significantly. A reformative switching network is proposed, which can eliminate the switch resistor's influence on the gain accuracy of the PGA. The measurement result shows the gain range of the circuit is 10-50 dB with a 1-dB step size, and the gain accuracy is less than ±0.3 dB. The OIP3 is 23.3 dBm at the gain of 10 dB. Simulation results show that the settling time is reduced from 100 to 1 ms. The image band rejection is about 40 dB. It only draws 4.5 mA current from a 1.8 V supply voltage.

  11. Frequency Comparison of Two High-Accuracy Al+ Optical Clocks

    CERN Document Server

    Chou, C -W; Koelemeij, J C J; Wineland, D J; Rosenband, T

    2009-01-01

    We have constructed an optical clock with a fractional frequency inaccuracy of 8.6e-18, based on quantum logic spectroscopy of an Al+ ion. A simultaneously trapped Mg+ ion serves to sympathetically laser-cool the Al+ ion and detect its quantum state. The frequency of the 1S0->3P0 clock transition is compared to that of a previously constructed Al+ optical clock with a statistical measurement uncertainty of 7.0e-18. The two clocks exhibit a relative stability of 2.8e-15/ sqrt(tau), and a fractional frequency difference of -1.8e-17, consistent with the accuracy limit of the older clock.

  12. Frequency Comparison of Two High-Accuracy Al+ Optical Clocks

    Science.gov (United States)

    Chou, C. W.; Hume, D. B.; Koelemeij, J. C. J.; Wineland, D. J.; Rosenband, T.

    2010-02-01

    We have constructed an optical clock with a fractional frequency inaccuracy of 8.6×10-18, based on quantum logic spectroscopy of an Al+ ion. A simultaneously trapped Mg+ ion serves to sympathetically laser cool the Al+ ion and detect its quantum state. The frequency of the S01↔P03 clock transition is compared to that of a previously constructed Al+ optical clock with a statistical measurement uncertainty of 7.0×10-18. The two clocks exhibit a relative stability of 2.8×10-15τ-1/2, and a fractional frequency difference of -1.8×10-17, consistent with the accuracy limit of the older clock.

  13. SpaceNav - A high accuracy navigation system for space applications

    Science.gov (United States)

    Evers, H.-H.

    The technology of the SpaceNav-system is based on research performed by the Institute of Flight Guidance and Control at the Technical University of Braunschweig, Germany. In 1989 this institute gave the worlds first public demonstration of a fully automatic landing of an aircraft, using inertial and satellite informations exclusively. The SpaceNav device components are: Acceleration-/Gyro Sensor Package; Global Positioning System (GPS) Receiver/optional more than one; Time Reference Unit; CPU; Telemetry (optional); and Differential GPS (DGPS) Receiver (optional). The coupling of GPS receivers with inertial sensors provides an extremely accurate navigation data set in real time applications even in phases with high dynamic conditions. The update rate of this navigation information is up to 100 Hz with the same accuracy in 3D-position, velocity, acceleration, attitude and time. SpaceNav is an integrated navigation system, which operates according to the principle of combining the longterm stability and accuracy of GPS, and the high level of dynamic precision of conventional inertial navigation system (INS) strapdown systems. The system's design allows other aiding sensors e.g. GLONASS satellite navigation system, distance measuring equipment (DME), altimeter (radar and/or barometric), flux valve etc. to be connected, in order to increase the redundancy of the system. The advantage of such an upgraded system is the availability of more sensor information than necessary for a navigation solution. The resulting redundancy in range measurement allows real-time detection and identification of sensor signals that are incompatible with the other information. As a result you get Receiver Autonomous Integrity Monitoring (RAIM) as described in 'A Multi-Sensor Approach to Assuring GPS Integrity', presented by Alison Brown in the March/April 1990 issue of 'GPS World'. In this paper the author presents information about the principles of the Satellite Navigation System GPS, and

  14. Accuracy of a Low Priced Liquid-Based Method for Cervical Cytology in 632 Women Referred for Colposcopy After a Positive Pap Smear

    NARCIS (Netherlands)

    van Hemel, B. M.; Buikema, H. J.; Groen, H.; Suurmeijer, A. J. H.

    2009-01-01

    The aim of this quality controlling study was to determine the accuracy of liquid-based cytology (LBC) with the Turbitec (R) cytocentrifuge technique. Cervical smears of 632 Women, Who were referred to our CIN outpatient department, after at least two smears with ASCUS or higher were evaluated and c

  15. Accuracy of a Low Priced Liquid-Based Method for Cervical Cytology in 632 Women Referred for Colposcopy After a Positive Pap Smear

    NARCIS (Netherlands)

    van Hemel, B. M.; Buikema, H. J.; Groen, H.; Suurmeijer, A. J. H.

    2009-01-01

    The aim of this quality controlling study was to determine the accuracy of liquid-based cytology (LBC) with the Turbitec (R) cytocentrifuge technique. Cervical smears of 632 Women, Who were referred to our CIN outpatient department, after at least two smears with ASCUS or higher were evaluated and c

  16. Accuracy of the high-throughput amplicon sequencing to identify species within the genus Aspergillus.

    Science.gov (United States)

    Lee, Seungeun; Yamamoto, Naomichi

    2015-12-01

    This study characterized the accuracy of high-throughput amplicon sequencing to identify species within the genus Aspergillus. To this end, we sequenced the internal transcribed spacer 1 (ITS1), β-tubulin (BenA), and calmodulin (CaM) gene encoding sequences as DNA markers from eight reference Aspergillus strains with known identities using 300-bp sequencing on the Illumina MiSeq platform, and compared them with the BLASTn outputs. The identifications with the sequences longer than 250 bp were accurate at the section rank, with some ambiguities observed at the species rank due to mostly cross detection of sibling species. Additionally, in silico analysis was performed to predict the identification accuracy for all species in the genus Aspergillus, where 107, 210, and 187 species were predicted to be identifiable down to the species rank based on ITS1, BenA, and CaM, respectively. Finally, air filter samples were analysed to quantify the relative abundances of Aspergillus species in outdoor air. The results were reproducible across biological duplicates both at the species and section ranks, but not strongly correlated between ITS1 and BenA, suggesting the Aspergillus detection can be taxonomically biased depending on the selection of the DNA markers and/or primers.

  17. Sensitivity analysis for high accuracy proximity effect correction

    Science.gov (United States)

    Thrun, Xaver; Browning, Clyde; Choi, Kang-Hoon; Figueiro, Thiago; Hohle, Christoph; Saib, Mohamed; Schiavone, Patrick; Bartha, Johann W.

    2015-10-01

    A sensitivity analysis (SA) algorithm was developed and tested to comprehend the influences of different test pattern sets on the calibration of a point spread function (PSF) model with complementary approaches. Variance-based SA is the method of choice. It allows attributing the variance of the output of a model to the sum of variance of each input of the model and their correlated factors.1 The objective of this development is increasing the accuracy of the resolved PSF model in the complementary technique through the optimization of test pattern sets. Inscale® from Aselta Nanographics is used to prepare the various pattern sets and to check the consequences of development. Fraunhofer IPMS-CNT exposed the prepared data and observed those to visualize the link of sensitivities between the PSF parameters and the test pattern. First, the SA can assess the influence of test pattern sets for the determination of PSF parameters, such as which PSF parameter is affected on the employments of certain pattern. Secondly, throughout the evaluation, the SA enhances the precision of PSF through the optimization of test patterns. Finally, the developed algorithm is able to appraise what ranges of proximity effect correction is crucial on which portion of a real application pattern in the electron beam exposure.

  18. High accuracy molecular line lists for exoplanetary atmospheres

    Science.gov (United States)

    Barber, R. J.; Tennyson, J.

    2008-09-01

    Water, carbon monoxide, methane and ammonia are major constituents exoplanetary atmospheres. Measurements of the relative abundances of these species are capable of yielding information about physical conditions, including: temperature, pressure, thermal profile and metallicity. Modern observational techniques and instrumentation mean that in principle, we now have the capability to detect these molecules in the emission and absorption spectra of transiting exoplanets. However, in order to be able to interpret these data, robust atmospheric models and complete and accurate molecular line lists are required. Our team at UCL is a world leader in the computation of molecular spectroscopic line lists. The BT2 water line list [1], which contains over 500 million transitions, was used in the first secure detection of H2O in the atmosphere of a transiting exoplanet [2]. We are currently computing a line list for NH3, which is a considerably more difficult task as the molecule has nine degrees of internal freedom (H2O has six). In this paper, we will discuss the ab initio computation of ro-vibrational molecular spectra and their application in exoplanetary studies. References [1] Barber R. J., Tennyson J., Harris G. J., Tolchenov R., 2006, MNRAS, 368, 1087 [2] Tinetti G. et al., 2007, Nature, 448, 169

  19. Distributed High Accuracy Peer-to-Peer Localization in Mobile Multipath Environments

    CERN Document Server

    Ekambaram, Venkatesan

    2010-01-01

    In this paper we consider the problem of high accuracy localization of mobile nodes in a multipath-rich environment where sub-meter accuracies are required. We employ a peer to peer framework where the vehicles/nodes can get pairwise multipath-degraded ranging estimates in local neighborhoods together with a fixed number of anchor nodes. The challenge is to overcome the multipath-barrier with redundancy in order to provide the desired accuracies especially under severe multipath conditions when the fraction of received signals corrupted by multipath is dominating. We invoke a message passing analytical framework based on particle filtering and reveal its high accuracy localization promise through simulations.

  20. A study for high accuracy real-time 3D ultrasonic location system.

    Science.gov (United States)

    Zhou, Ping; Ha, Zhang; Zhou, Kangyuan

    2006-12-22

    We discussed a high accuracy real-time 3D ultrasonic location system in this article. The signal received was sampled after it passed the TGC and the logarithmic amplifier. Inside the DSP, we used the dynamic threshold tracing technique to improve the accuracy. The result was processed with Weighted Arithmetic Average. By testing the 40 kHz 3D location system, we have arrived at the accuracy of 1 cm.

  1. Generation of remotely sensed reference data using low altitude, high spatial resolution hyperspectral imagery

    Science.gov (United States)

    Williams, McKay D.; van Aardt, Jan; Kerekes, John P.

    2016-05-01

    Exploitation of imaging spectroscopy (hyperspectral) data using classification and spectral unmixing algorithms is a major research area in remote sensing, with reference data required to assess algorithm performance. However, we are limited by our inability to generate rapid, accurate, and consistent reference data, thus making quantitative algorithm analysis difficult. As a result, many investigators present either limited quantitative results, use synthetic imagery, or provide qualitative results using real imagery. Existing reference data typically classify large swaths of imagery pixel-by-pixel, per cover type. While this type of mapping provides a first order understanding of scene composition, it is not detailed enough to include complexities such as mixed pixels, intra-end-member variability, and scene anomalies. The creation of more detailed ground reference data based on field work, on the other hand, is complicated by the spatial scale of common hyperspectral data sets. This research presents a solution to this challenge via classification of low altitude, high spatial resolution (1m GSD) National Ecological Observatory Network (NEON) hyperspectral imagery, on a pixel-by-pixel basis, to produce sub-pixel reference data for high altitude, lower spatial resolution (15m GSD) AVIRIS imagery. This classification is performed using traditional classification techniques, augmented by (0.3m GSD) NEON RGB data. This paper provides a methodology for generating large scale, sub-pixel reference data for AVIRIS imagery using NEON imagery. It also addresses challenges related to the fusion of multiple remote sensing modalities (e.g., different sensors, sensor look angles, spatial registration, varying scene illumination, etc.). A new algorithm for spatial registration of hyperspectral imagery with disparate resolutions is presented. Several versions of reference data results are compared to each other and to direct spectral unmixing of AVIRIS data. Initial results are

  2. Accuracy of Handheld Blood Glucose Meters at High Altitude

    NARCIS (Netherlands)

    de Mol, Pieter; Krabbe, Hans G.; de Vries, Suzanna T.; Fokkert, Marion J.; Dikkeschei, Bert D.; Rienks, Rienk; Bilo, Karin M.; Bilo, Henk J. G.

    2010-01-01

    Background: Due to increasing numbers of people with diabetes taking part in extreme sports (e. g., high-altitude trekking), reliable handheld blood glucose meters (BGMs) are necessary. Accurate blood glucose measurement under extreme conditions is paramount for safe recreation at altitude. Prior st

  3. Development of high accuracy and resolution geoid and gravity maps

    Science.gov (United States)

    Gaposchkin, E. M.

    1986-01-01

    Precision satellite to satellite tracking can be used to obtain high precision and resolution maps of the geoid. A method is demonstrated to use data in a limited region to map the geopotential at the satellite altitude. An inverse method is used to downward continue the potential to the Earth surface. The method is designed for both satellites in the same low orbit.

  4. Accuracy of Answers Provided by Digital/Face-to-Face Reference Services in Japanese Public Libraries and Q & A Sites

    Science.gov (United States)

    Tsuji, Keita; To, Haruna; Hara, Atsuyuki

    2011-01-01

    We asked the same 60 questions using DRS (digital reference services) in Japanese public libraries, face-to-face reference services and Q & A (question and answer) sites. It was found that: (1) The correct answer ratio of DRS is higher than that of Q & A sites; (2) DRS takes longer to provide answers as compared to Q & A sites; and (3)…

  5. Salivary cortisol and cortisone by LC-MS/MS: validation, reference intervals and diagnostic accuracy in Cushing's syndrome.

    Science.gov (United States)

    Antonelli, Giorgia; Ceccato, Filippo; Artusi, Carlo; Marinova, Mariela; Plebani, Mario

    2015-12-07

    The Endocrine Society recommends late-night salivary cortisol (LNS-F) as a first-line screening test for Cushing's syndrome (CS). In the parotid gland, 11β-hydroxysteroid dehydrogenase type 2 inactivates cortisol (F) to cortisone (E), a known source of interference in the more frequently used immunoassays. A highly specific method is mandatory in determining salivary F and E: it is widely accepted that liquid chromatography-tandem mass spectrometry (LC-MS/MS) is the best available technique for this purpose. A LC-MS/MS method with SPE of saliva samples was developed and validated. Appropriate awakening and bedtime reference ranges were established. The diagnostic performance for F, E and the ratio at bedtime was evaluated in 25 cases of CS. The method was linear, with up to 55.4 nmol/L and 51.0 nmol/L, LLOQ of 0.51 nmol/L and 0.55 nmol/L, for F and E, respectively. Within-run and between-run imprecisions were <10% for both analytes. No ion suppression was observed. A cut-off of 2.4 nmol/L for LNS-F yielded a sensitivity of 100% and a specificity of 98% in the diagnosis of CS. The analytical performance of this method justifies its introduction into clinical practice, thus allowing clinicians the opportunity to further investigate CS and other endocrine diseases. Copyright © 2015 Elsevier B.V. All rights reserved.

  6. High accuracy magnetic field sensors with wide operation temperature range

    Science.gov (United States)

    Vasil'evskii, I. S.; Vinichenko, A. N.; Rubakin, D. I.; Bolshakova, I. A.; Kargin, N. I.

    2016-10-01

    n+InAs(Si) epitaxial thin films heavily doped by silicon and Hall effect magnetic field sensors based on this structures have been fabricated and studied. We have demonstrated the successful formation of highly doped InAs thin films (∼100 nm) with the different intermediate layer arrangement and appropriate electron mobility values. Hall sensors performance parameters have been measured in wide temperature range. Obtained sensitivity varied from 1 to 40 Ω/T, while the best linearity and lower temperature coefficient have been found in the higher doped samples with lower electron mobility. We attribute this to the electron system degeneracy and decreased phonon contribution to electron mobility and resistance.

  7. A High Accuracy Method for Semi-supervised Information Extraction

    Energy Technology Data Exchange (ETDEWEB)

    Tratz, Stephen C.; Sanfilippo, Antonio P.

    2007-04-22

    Customization to specific domains of dis-course and/or user requirements is one of the greatest challenges for today’s Information Extraction (IE) systems. While demonstrably effective, both rule-based and supervised machine learning approaches to IE customization pose too high a burden on the user. Semi-supervised learning approaches may in principle offer a more resource effective solution but are still insufficiently accurate to grant realistic application. We demonstrate that this limitation can be overcome by integrating fully-supervised learning techniques within a semi-supervised IE approach, without increasing resource requirements.

  8. Accuracy of Acuros XB and AAA dose calculation for small fields with reference to RapidArc stereotactic treatments

    Energy Technology Data Exchange (ETDEWEB)

    Fogliata, Antonella; Nicolini, Giorgia; Clivio, Alessandro; Vanetti, Eugenio; Cozzi, Luca [Oncology Institute of Southern Switzerland, Medical Physics Unit, CH-6500 Bellinzona (Switzerland)

    2011-11-15

    Purpose: To assess the accuracy against measurements of two photon dose calculation algorithms (Acuros XB and the Anisotropic Analytical algorithm AAA) for small fields usable in stereotactic treatments with particular focus on RapidArc. Methods: Acuros XB and AAA were configured for stereotactic use. Baseline accuracy was assessed on small jaw-collimated open fields for different values for the spot sizes parameter in the beam data: 0.0, 0.5, 1, and 2 mm. Data were calculated with a grid of 1 x 1 mm{sup 2}. Investigated fields were: 3 x 3, 2 x 2, 1 x 1, and 0.8 x 0.8 cm{sup 2} with a 6 MV photon beam generated from a Clinac2100iX (Varian, Palo Alto, CA). Profiles, PDD, and output factors were measured in water with a PTW diamond detector (detector size: 4 mm{sup 2}, thickness 0.4 mm) and compared to calculations. Four RapidArc test plans were optimized, calculated and delivered with jaw settings J3 x 3, J2 x 2, and J1 x 1 cm{sup 2}, the last was optimized twice to generate high (H) and low (L) modulation patterns. Each plan consisted of one partial arc (gantry 110 deg. to 250 deg.), and collimator 45 deg. Dose to isocenter was measured in a PTW Octavius phantom and compared to calculations. 2D measurements were performed by means of portal dosimetry with the GLAaS method developed at authors' institute. Analysis was performed with gamma pass-fail test with 3% dose difference and 2 mm distance to agreement thresholds. Results: Open square fields: penumbrae from open field profiles were in good agreement with diamond measurements for 1 mm spot size setting for Acuros XB, and between 0.5 and 1 mm for AAA. Maximum MU difference between calculations and measurements was 1.7% for Acuros XB (0.2% for fields greater than 1 x 1 cm{sup 2}) with 0.5 or 1 mm spot size. Agreement for AAA was within 0.7% (2.8%) for 0.5 (1 mm) spot size. RapidArc plans: doses were evaluated in a 4 mm diameter structure at isocenter and computed values differed from measurements by 0.0, -0

  9. Accuracy of Acuros XB and AAA dose calculation for small fields with reference to RapidArc(®) stereotactic treatments.

    Science.gov (United States)

    Fogliata, Antonella; Nicolini, Giorgia; Clivio, Alessandro; Vanetti, Eugenio; Cozzi, Luca

    2011-11-01

    To assess the accuracy against measurements of two photon dose calculation algorithms (Acuros XB and the Anisotropic Analytical algorithm AAA) for small fields usable in stereotactic treatments with particular focus on RapidArc(®). Acuros XB and AAA were configured for stereotactic use. Baseline accuracy was assessed on small jaw-collimated open fields for different values for the spot sizes parameter in the beam data: 0.0, 0.5, 1, and 2 mm. Data were calculated with a grid of 1 × 1 mm(2). Investigated fields were: 3 × 3, 2 × 2, 1 × 1, and 0.8 × 0.8 cm(2) with a 6 MV photon beam generated from a Clinac2100iX (Varian, Palo Alto, CA). Profiles, PDD, and output factors were measured in water with a PTW diamond detector (detector size: 4 mm(2), thickness 0.4 mm) and compared to calculations. Four RapidArc test plans were optimized, calculated and delivered with jaw settings J3 × 3, J2 × 2, and J1 × 1 cm(2), the last was optimized twice to generate high (H) and low (L) modulation patterns. Each plan consisted of one partial arc (gantry 110° to 250°), and collimator 45°. Dose to isocenter was measured in a PTW Octavius phantom and compared to calculations. 2D measurements were performed by means of portal dosimetry with the GLAaS method developed at authors' institute. Analysis was performed with gamma pass-fail test with 3% dose difference and 2 mm distance to agreement thresholds. Open square fields: penumbrae from open field profiles were in good agreement with diamond measurements for 1 mm spot size setting for Acuros XB, and between 0.5 and 1 mm for AAA. Maximum MU difference between calculations and measurements was 1.7% for Acuros XB (0.2% for fields greater than 1 × 1 cm(2)) with 0.5 or 1 mm spot size. Agreement for AAA was within 0.7% (2.8%) for 0.5 (1 mm) spot size. RapidArc plans: doses were evaluated in a 4 mm diameter structure at isocenter and computed values differed from measurements by 0.0, -0.2, 5.5, and

  10. A New CMOS Current Reference with High Order Temperature Compensation

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    A new high order CMOS temperature compensated current reference is proposed in this paper, which is accomplished by two first order temperature compensation current references. The novel circuit exploits the temperature characteristics of integrated-circuit resistors and gate-source voltage of MOS transistors working in weak inversion. The proposed circuit, designed with a 0.6 (m standard CMOS technology, gives a good temperature coefficient of 31ppm/℃ [(50~100℃] at a 1.8 V supply, and also achieves line regulation of 0.01%/V and (120 dB PSR at 1 MHz. Comparing with other presented work, the proposed circuit shows better temperature coefficient and Line regulation.

  11. Traffic Sign Recognition with High Accuracy Using Mixture of Experts

    Directory of Open Access Journals (Sweden)

    Reza Azad

    2014-06-01

    Full Text Available Traffic signs provide the driver various information for safe and efficient navigation. Automatic recognition of traffic signs is, therefore, important for automated driving or driver assistance systems.In this paper, a new and efficient traffic sign recognition system based on extracting diverse feature set, and applying mixture of experts'architecture on the extracted featuresis proposed.In the result part, the proposed approach is evaluated on the German traffic sign recognition and Grigorescu traffic signsbenchmark and high recognition rate is achieved.Comparison with some of the most related methods indicates that the proposed novel model yields excellent recognition rate in traffic sign recognition that is the recognition rate of 99.94% for the training set and 98.50% for the test set.In addition, experimental results have demonstrated our method robust in successful recognition of traffic signs even with variant lighting.

  12. Gated viewing and high-accuracy three-dimensional laser radar

    DEFF Research Database (Denmark)

    Busck, Jens; Heiselberg, Henning

    2004-01-01

    We have developed a fast and high-accuracy three-dimensional (3-D) imaging laser radar that can achieve better than 1 mm range accuracy for half a million pixels in less than 1 s. Our technique is based on range-gating segmentation. We combine the advantages of gated viewing with our new fast...

  13. Gated viewing and high-accuracy three-dimensional laser radar

    DEFF Research Database (Denmark)

    Busck, Jens; Heiselberg, Henning

    2004-01-01

    We have developed a fast and high-accuracy three-dimensional (3-D) imaging laser radar that can achieve better than 1 mm range accuracy for half a million pixels in less than 1 s. Our technique is based on range-gating segmentation. We combine the advantages of gated viewing with our new fast...

  14. A High-Throughput, High-Accuracy System-Level Simulation Framework for System on Chips

    Directory of Open Access Journals (Sweden)

    Guanyi Sun

    2011-01-01

    Full Text Available Today's System-on-Chips (SoCs design is extremely challenging because it involves complicated design tradeoffs and heterogeneous design expertise. To explore the large solution space, system architects have to rely on system-level simulators to identify an optimized SoC architecture. In this paper, we propose a system-level simulation framework, System Performance Simulation Implementation Mechanism, or SPSIM. Based on SystemC TLM2.0, the framework consists of an executable SoC model, a simulation tool chain, and a modeling methodology. Compared with the large body of existing research in this area, this work is aimed at delivering a high simulation throughput and, at the same time, guaranteeing a high accuracy on real industrial applications. Integrating the leading TLM techniques, our simulator can attain a simulation speed that is not slower than that of the hardware execution by a factor of 35 on a set of real-world applications. SPSIM incorporates effective timing models, which can achieve a high accuracy after hardware-based calibration. Experimental results on a set of mobile applications proved that the difference between the simulated and measured results of timing performance is within 10%, which in the past can only be attained by cycle-accurate models.

  15. The accuracy of QCD perturbation theory at high energies

    CERN Document Server

    Dalla Brida, Mattia; Korzec, Tomasz; Ramos, Alberto; Sint, Stefan; Sommer, Rainer

    2016-01-01

    We discuss the determination of the strong coupling $\\alpha_\\mathrm{\\overline{MS}}^{}(m_\\mathrm{Z})$ or equivalently the QCD $\\Lambda$-parameter. Its determination requires the use of perturbation theory in $\\alpha_s(\\mu)$ in some scheme, $s$, and at some energy scale $\\mu$. The higher the scale $\\mu$ the more accurate perturbation theory becomes, owing to asymptotic freedom. As one step in our computation of the $\\Lambda$-parameter in three-flavor QCD, we perform lattice computations in a scheme which allows us to non-perturbatively reach very high energies, corresponding to $\\alpha_s = 0.1$ and below. We find that perturbation theory is very accurate there, yielding a three percent error in the $\\Lambda$-parameter, while data around $\\alpha_s \\approx 0.2$ is clearly insufficient to quote such a precision. It is important to realize that these findings are expected to be generic, as our scheme has advantageous properties regarding the applicability of perturbation theory.

  16. High Precision UTDR Measurements by Sonic Velocity Compensation with Reference Transducer

    Directory of Open Access Journals (Sweden)

    Sam Stade

    2014-07-01

    Full Text Available An ultrasonic sensor design with sonic velocity compensation is developed to improve the accuracy of distance measurement in membrane modules. High accuracy real-time distance measurements are needed in membrane fouling and compaction studies. The benefits of the sonic velocity compensation with a reference transducer are compared to the sonic velocity calculated with the measured temperature and pressure using the model by Belogol’skii, Sekoyan et al. In the experiments the temperature was changed from 25 to 60 °C at pressures of 0.1, 0.3 and 0.5 MPa. The set measurement distance was 17.8 mm. Distance measurements with sonic velocity compensation were over ten times more accurate than the ones calculated based on the model. Using the reference transducer measured sonic velocity, the standard deviations for the distance measurements varied from 0.6 to 2.0 µm, while using the calculated sonic velocity the standard deviations were 21–39 µm. In industrial liquors, not only the temperature and the pressure, which were studied in this paper, but also the properties of the filtered solution, such as solute concentration, density, viscosity, etc., may vary greatly, leading to inaccuracy in the use of the Belogol’skii, Sekoyan et al. model. Therefore, calibration of the sonic velocity with reference transducers is needed for accurate distance measurements.

  17. Methodology of High Accuracy and Resolution 3D Geological Model Generation and Application

    Institute of Scientific and Technical Information of China (English)

    吴键; 曹代勇; 邓爱居; 李东津; 蒋涛; 翟光华

    2004-01-01

    By generating a high accuracy and high resolution geological model in Liuchu oil field, the technique of geological modeling is expanded and involved in primary geological study, making the sand bodies and reservoir be easily described in detail. The 3D visualization and 3D interactive editing of geological structure model are the key for modeling procedure. And a high accuracy and resolution geological model has been well applied in optimizing the production scheme.

  18. Evaluation of the quantitative accuracy of 3D reconstruction of edentulous jaw models with jaw relation based on reference point system alignment.

    Directory of Open Access Journals (Sweden)

    Weiwei Li

    Full Text Available OBJECTIVES: To apply contact measurement and reference point system (RPS alignment techniques to establish a method for 3D reconstruction of the edentulous jaw models with centric relation and to quantitatively evaluate its accuracy. METHODS: Upper and lower edentulous jaw models were clinically prepared, 10 pairs of resin cylinders with same size were adhered to axial surfaces of upper and lower models. The occlusal bases and the upper and lower jaw models were installed in the centric relation position. Faro Edge 1.8m was used to directly obtain center points of the base surface of the cylinders (contact method. Activity 880 dental scanner was used to obtain 3D data of the cylinders and the center points were fitted (fitting method. 3 pairs of center points were used to align the virtual model to centric relation. An observation coordinate system was interactively established. The straight-line distances in the X (horizontal left/right, Y (horizontal anterior/posterior, and Z (vertical between the remaining 7 pairs of center points derived from contact method and fitting method were measured respectively and analyzed using a paired t-test. RESULTS: The differences of the straight-line distances of the remaining 7 pairs of center points between the two methods were X: 0.074 ± 0.107 mm, Y: 0.168 ± 0.176 mm, and Z: -0.003± 0.155 mm. The results of paired t-test were X and Z: p >0.05, Y: p <0.05. CONCLUSION: By using contact measurement and the reference point system alignment technique, highly accurate reconstruction of the vertical distance and centric relation of a digital edentulous jaw model can be achieved, which meets the design and manufacturing requirements of the complete dentures. The error of horizontal anterior/posterior jaw relation was relatively large.

  19. High-speed, high-accuracy large range 3D measurement

    Science.gov (United States)

    An, Yatong; Zhang, Song

    2017-05-01

    This paper presents such a high-speed, high-accuracy structured light technique that could achieve large range 3D shape measurement. The enabling method is our recently proposed system calibration that splits the calibration process into two stages. Specifically, we calibrate the intrinsic parameters at a near position with a regular size yet precisely fabricated calibration target, and then calibrate the extrinsic parameters with the assistance of an additional large range yet low accuracy low cost 3D scanner (i.e., Kinect). We developed a system that achieved 500 Hz with a resolution 2304 × 1400. The field of view (FOV) of our structured light system is 0.9 m(W) × 1.4 m(H) × 0.8 m(D). Our experimental data demonstrated that such a large range structured light system can achieve an mean error of 0.13 mm with a standard deviation of 1.18 mm by measuring a 304.8 mm diameter sphere. We further experimentally demonstrated that proposed method can simultaneously measure multiple objects or large dynamically changing objects.

  20. High accuracy and transferability of a neural network potential through charge equilibration for calcium fluoride

    Science.gov (United States)

    Faraji, Somayeh; Ghasemi, S. Alireza; Rostami, Samare; Rasoulkhani, Robabe; Schaefer, Bastian; Goedecker, Stefan; Amsler, Maximilian

    2017-03-01

    We investigate the accuracy and transferability of a recently developed high-dimensional neural network (NN) method for calcium fluoride, fitted to a database of ab initio density functional theory (DFT) calculations based on the Perdew-Burke-Ernzerhof (PBE) exchange correlation functional. We call the method charge equilibration via neural network technique (CENT). Although the fitting database contains only clusters (i.e., nonperiodic structures), the NN scheme accurately describes a variety of bulk properties. In contrast to other available empirical methods the CENT potential has a much simpler functional form, nevertheless it correctly reproduces the PBE energetics of various crystalline phases both at ambient and high pressure. Surface energies and structures as well as dynamical properties derived from phonon calculations are also in good agreement with PBE results. Overall, the difference between the values obtained by the CENT potential and the PBE reference values is less than or equal to the difference between the values of local density approximation (LDA) and Born-Mayer-Huggins (BMH) with those calculated by the PBE exchange correlation functional.

  1. State of the art in high accuracy high detail DTMs derived from ALS

    Science.gov (United States)

    Pfeifer, N.; Briese, C.; Mandlburger, G.; Höfle, B.; Ressl, C.

    2009-04-01

    High-resolution Digital Terrain Models (DTMs) representing the bare Earth are a fundamental input for various applications in geomorphology. Airborne laser scanning (ALS) is established as a standard tool for deriving DTMs over large areas with unprecedented accuracy. Due to advances in sensor technology and in processing algorithms in the recent years the obtainable accuracy is still increasing. Accuracy is understood as the deviation from the elevation at one specified point to its true value. These advances may lead to a more efficient data acquisition, if reduced accuracy is targeted, but also allow data acquisition schemes with more detail becoming visible, i.e. small features of the relief. For the latter a high internal precision, i.e. repeatability, is necessary. The essential advances in the technologies are improvements in ranging through the introduction of full-waveform (FWF) laser scanning and rigorous models of strip adjustment. In FWF laser scanning the time-dependent strength of the backscattered signal is recorded. This is opposed to the analogue processing of the incoming energy and storage of one arrival time of discrete-return systems. In a simple one-echo situation, the arrival time corresponds to the maximum of the waveform. By applying a decomposition of the full waveform into single echoes, which are transformed copies of the emitted signal, it is possible to retrieve more echoes per shot. Additionally, if echoes of individual scatterers are overlapping, FWF sensors might be able to separate them, whereas discrete return systems might rather only be able to derive one collective arrival time. Finally, the overlay of two echoes does not have the maxima at the same positions as the individual echoes. Additionally, the pulse repetition rate of laser scanners has increased, which allows higher point densities and therefore higher richness of detail. These advances in data acquisition increase the precision within one ALS strip. Deficiencies in

  2. Bayesian meta-analysis of test accuracy in the absence of a perfect reference test applied to bone scintigraphy for the diagnosis of complex regional pain syndrome.

    Science.gov (United States)

    Held, Ulrike; Brunner, Florian; Steurer, Johann; Wertli, Maria M

    2015-11-01

    There is conflicting evidence about the accuracy of bone scintigraphy (BS) for the diagnosis of complex regional pain syndrome 1 (CRPS 1). In a meta-analysis of diagnostic studies, the evaluation of test accuracy is impeded by the use of different imperfect reference tests. The aim of our study is to summarize sensitivity and specificity of BS for CRPS 1 and to identify factors to explain heterogeneity. We use a hierarchical Bayesian approach to model test accuracy and threshold, and we present different models accounting for the imperfect nature of the reference tests, and assuming conditional dependence between BS and the reference test results. Further, we include disease duration as explanatory variable in the model. The models are compared using summary ROC curves and the deviance information criterion (DIC). Our results show that those models which account for different imperfect reference tests with conditional dependence and inclusion of the covariate are the ones with the smallest DIC. The sensitivity of BS was 0.87 (95% credible interval 0.73-0.97) and the overall specificity was 0.87 (0.73-0.95) in the model with the smallest DIC, in which missing values of the covariate are imputed within the Bayesian framework. The estimated effect of duration of symptoms on the threshold parameter was 0.17 (-0.25 to 0.57). We demonstrate that the Bayesian models presented in this paper are useful to address typical problems occurring in meta-analysis of diagnostic studies, including conditional dependence between index test and reference test, as well as missing values in the study-specific covariates.

  3. High-accuracy interferometric measurements of flatness and parallelism of a step gauge

    CSIR Research Space (South Africa)

    Kruger, OA

    2001-01-01

    Full Text Available for the calibration of step gauges to a high accuracy. A system was also developed for interferometric measurements of the flatness and parallelism of gauge block faces for use in uncertainty calculations....

  4. High PSRR bandgap reference used in boost circuit

    Science.gov (United States)

    Li, Yi; Duan, Baoxing; Wang, Yong; Yang, Yintang

    2017-03-01

    Based on pre-regulated voltage structure, a voltage bandgap reference with high power supply rejection ratio (PSRR) is presented in this paper. A pre-regulated voltage structure is used in the circuit to achieve isolating the supply voltage of the bandgap core circuit from VDD to reach a high PSRR. The circuit was designed and simulated in 0.35um BCD technology. The results show the output voltage variation versus temperature (-50°C -100°C) is 8.8 ppm/°C, bandgap reference voltage is 1.236V, current consumption is 30.3 µA. Noise is 53.54 µV/Hz-1/2 at 1Hz. PSRR is -91dB at low frequency, -90.3dB at 1 kHz and -30.3dB at 1MHz. thus, the circuit maintains a good performance in PSRR through a broad frequency.

  5. High Flux Isotope Reactor cold neutron source reference design concept

    Energy Technology Data Exchange (ETDEWEB)

    Selby, D.L.; Lucas, A.T.; Hyman, C.R. [and others

    1998-05-01

    In February 1995, Oak Ridge National Laboratory`s (ORNL`s) deputy director formed a group to examine the need for upgrades to the High Flux Isotope Reactor (HFIR) system in light of the cancellation of the Advanced neutron Source Project. One of the major findings of this study was that there was an immediate need for the installation of a cold neutron source facility in the HFIR complex. In May 1995, a team was formed to examine the feasibility of retrofitting a liquid hydrogen (LH{sub 2}) cold source facility into an existing HFIR beam tube. The results of this feasibility study indicated that the most practical location for such a cold source was the HB-4 beam tube. This location provides a potential flux environment higher than the Institut Laue-Langevin (ILL) vertical cold source and maximizes the space available for a future cold neutron guide hall expansion. It was determined that this cold neutron beam would be comparable, in cold neutron brightness, to the best facilities in the world, and a decision was made to complete a preconceptual design study with the intention of proceeding with an activity to install a working LH{sub 2} cold source in the HFIR HB-4 beam tube. During the development of the reference design the liquid hydrogen concept was changed to a supercritical hydrogen system for a number of reasons. This report documents the reference supercritical hydrogen design and its performance. The cold source project has been divided into four phases: (1) preconceptual, (2) conceptual design and testing, (3) detailed design and procurement, and (4) installation and operation. This report marks the conclusion of the conceptual design phase and establishes the baseline reference concept.

  6. Rapid, high-accuracy detection of strabismus and amblyopia using the pediatric vision scanner.

    Science.gov (United States)

    Loudon, Sjoukje E; Rook, Caitlin A; Nassif, Deborah S; Piskun, Nadya V; Hunter, David G

    2011-07-07

    Purpose. The Pediatric Vision Scanner (PVS) detects strabismus by identifying ocular fixation in both eyes simultaneously. This study was undertaken to assess the ability of the PVS to identify patients with amblyopia or strabismus, particularly anisometropic amblyopia with no measurable strabismus. Methods. The PVS test, administered from 40 cm and requiring 2.5 seconds of attention, generated a binocularity score (BIN, 0%-100%). We tested 154 patients and 48 controls between the ages of 2 and 18 years. BIN scores of amblyopic children and controls were measured, and 21 children received sequential PVS measurements to detect any changes in BIN resulting from amblyopia treatment. Results. With the pass/refer threshold set at BIN 60%, sensitivity and specificity were 96% for the detection of amblyopia or strabismus. Assuming a 5% prevalence of amblyopia or strabismus, the inferred positive and negative predictive values of the PVS were 56% and 100%, respectively. Fixation accuracy was significantly reduced in amblyopic eyes. In anisometropic amblyopia patients treated successfully, the BIN improved to 100%. Conclusions. The PVS identified children with amblyopia or strabismus with high sensitivity and specificity, while successful treatment restored normal BIN scores in amblyopic patients without strabismus. The results support the hypothesis that the PVS detects strabismus and amblyopia directly. Future strategies for screening by nonspecialists may thus be based on diagnostic detection of amblyopia and strabismus rather than the estimation of risk factors, allowing for rapid, accurate identification of children with amblyopia early in life when it is most amenable to treatment.

  7. High-Order Kinetic Relaxation Schemes as High-Accuracy Poisson Solvers

    CERN Document Server

    Mendoza, M; Herrmann, H J

    2015-01-01

    We present a new approach to find accurate solutions to the Poisson equation, as obtained from the steady-state limit of a diffusion equation with strong source terms. For this purpose, we start from Boltzmann's kinetic theory and investigate the influence of higher order terms on the resulting macroscopic equations. By performing an appropriate expansion of the equilibrium distribution, we provide a method to remove the unnecessary terms up to a desired order and show that it is possible to find, with high level of accuracy, the steady-state solution of the diffusion equation for sizeable Knudsen numbers. In order to test our kinetic approach, we discretise the Boltzmann equation and solve the Poisson equation, spending up to six order of magnitude less computational time for a given precision than standard lattice Boltzmann methods.

  8. High-Performance Optical Frequency References for Space

    Science.gov (United States)

    Schuldt, Thilo; Döringshoff, Klaus; Milke, Alexander; Sanjuan, Josep; Gohlke, Martin; Kovalchuk, Evgeny V.; Gürlebeck, Norman; Peters, Achim; Braxmaier, Claus

    2016-06-01

    A variety of future space missions rely on the availability of high-performance optical clocks with applications in fundamental physics, geoscience, Earth observation and navigation and ranging. Examples are the gravitational wave detector eLISA (evolved Laser Interferometer Space Antenna), the Earth gravity mission NGGM (Next Generation Gravity Mission) and missions, dedicated to tests of Special Relativity, e.g. by performing a Kennedy- Thorndike experiment testing the boost dependence of the speed of light. In this context we developed optical frequency references based on Doppler-free spectroscopy of molecular iodine; compactness and mechanical and thermal stability are main design criteria. With a setup on engineering model (EM) level we demonstrated a frequency stability of about 2·10-14 at an integration time of 1 s and below 6·10-15 at integration times between 100s and 1000s, determined from a beat-note measurement with a cavity stabilized laser where a linear drift was removed from the data. A cavity-based frequency reference with focus on improved long-term frequency stability is currently under development. A specific sixfold thermal shield design based on analytical methods and numerical calculations is presented.

  9. High precision optomechanical assembly using threads as mechanical reference

    Science.gov (United States)

    Lamontagne, Frédéric; Desnoyers, Nichola; Bergeron, Guy; Cantin, Mario

    2016-09-01

    A convenient method to assemble optomechanical components is to use threaded interface. For example, lenses are often secured inside barrels using threaded rings. In other cases, multiple optical sub-assemblies such as lens barrels can be threaded to each other. Threads have the advantage to provide a simple assembly method, to be easy to manufacture, and to offer a compact mechanical design. On the other hand, threads are not considered to provide accurate centering between parts because of the assembly clearance between the inner and outer threads. For that reason, threads are often used in conjunction with precision cylindrical surfaces to limit the radial clearance between the parts to be centered. Therefore, tight manufacturing tolerances are needed on these pilot diameters, which affect the cost of the optical assembly. This paper presents a new optomechanical approach that uses threads as mechanical reference. This innovative method relies on geometric principles to auto-center parts to each other with a very low centering error that is usually less than 5 μm. The method allows to auto-center an optical group in a main barrel, to perform an axial adjustment of an optical group inside a main barrel, and to perform stacking of multiple barrels. In conjunction with the lens auto-centering method that also used threads as a mechanical reference, this novel solution opens new possibilities to realize a variety of different high precision optomechanical assemblies at lower cost.

  10. Use of Reference Ear Plug to improve accuracy of lateral cephalograms generated from cone-beam computed tomography scans

    OpenAIRE

    Hwang, Hyeon-Shik; Lee, Kyung-Min; Uhm, Gi-Soo; Cho, Jin-Hyoung; McNamara, James A.

    2013-01-01

    Objective The purpose of this study was to evaluate the effectiveness of the use of Reference Ear Plug (REP) during cone-beam computed tomography (CBCT) scan for the generation of lateral cephalograms from CBCT scan data. Methods Two CBCT scans were obtained from 33 adults. One CBCT scan was acquired using conventional methods, and the other scan was acquired with the use of REP. Virtual lateral cephalograms created from each CBCT image were traced and compared with tracings of the real cepha...

  11. Highly charged ions as a basis of optical atomic clockwork of exceptional accuracy.

    Science.gov (United States)

    Derevianko, Andrei; Dzuba, V A; Flambaum, V V

    2012-11-02

    We propose a novel class of atomic clocks based on highly charged ions. We consider highly forbidden laser-accessible transitions within the 4f(12) ground-state configurations of highly charged ions. Our evaluation of systematic effects demonstrates that these transitions may be used for building exceptionally accurate atomic clocks which may compete in accuracy with recently proposed nuclear clocks.

  12. Accuracy of potentiometric oxygen sensors with Bi/Bi{sub 2}O{sub 3} reference electrode for use in liquid LBE

    Energy Technology Data Exchange (ETDEWEB)

    Lim, J., E-mail: jlim@sckcen.be [Belgian Nuclear Research Centre (SCK-CEN), Boeretang 200, B-2400 Mol (Belgium); Marieen, A.; Rosseel, K.; Aerts, A.; Van den Bosch, J. [Belgian Nuclear Research Centre (SCK-CEN), Boeretang 200, B-2400 Mol (Belgium)

    2012-10-15

    Potentiometric oxygen sensors fabricated with yttria partially stabilized zirconia (YPSZ) and a Bi/Bi{sub 2}O{sub 3} reference electrode were tested in oxygen saturated lead-bismuth eutectic (LBE) and oxygen saturated tin (Sn), respectively, in order to estimate the accuracy of the oxygen sensors prior to applying them to R and D work for MYRRHA. The accuracy of these sensors was estimated in the temperature range of 673-733 K by measuring the electromotive force (emf) of eight sensors. The standard deviation on the measured emf data was about 0.79 mV in the case of oxygen saturated LBE and was about 1.25 mV in the case of oxygen saturated Sn. These values result in a standard deviation of 4% on the oxygen concentration in LBE which is calculated from the measured emf.

  13. Development of an automatic calibration device for high-accuracy low temperature thermometers

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    Based on the analysis and investigation of calibration systems for high-accuracy low temperature thermometers,a new facility for automatic calibration of high-accuracy low temperature thermometers was developed.Continuous calibration for multiple points can be made automatically with this device.According to the thermophysical characteristics of the constant-temperature block in this device,segmented Fuzzy-PID (proportional-integral-differential) algorithm was applied.The experimental results showed that the temperature fluctuation was smaller than ±0.005 K in 30 min.Therefore,this new device can fully meet the calibration requirement of high-precision low temperature thermometers.

  14. Effects of the composition of standard reference material on the accuracy of determinations of {sup 210}Pb and {sup 137}Cs in soils with gamma spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Li, Y., E-mail: yongli32@hotmail.co [State Key Laboratory of Dryland Farming and Soil Erosion in the Loess Plateau, Institute of Soil and Water Conservation, CAS and MWR, Yangling 712100 (China); Institute of Environment and Sustainable Development in Agriculture, CAAS, No. 12 Zhongguancun South Street, Beijing 100081 (China); Geng, X.C.; Yu, H.Q. [Institute of Environment and Sustainable Development in Agriculture, CAAS, No. 12 Zhongguancun South Street, Beijing 100081 (China); Wan, G.J. [State Key Laboratory of Environmental Geochemistry, Institute of Geochemistry, Chinese Academy of Sciences, Guiyang (China)

    2011-02-15

    The effect of the composition of the used standard reference material (SRM) on results of determination of fallout radionuclides in soil samples was studied. Using five soil types as SRMs, we measured the specific activity of {sup 210}Pb and {sup 137}Cs in six target samples of Chestnut soil. It was observed that the determination of the {sup 210}Pb activity in the samples depended on the chemical composition of SRMs used to create the efficiency curves. Thus, using SRMs similar in chemical composition to the target samples should improve accuracy in the determination of {sup 210}Pb in environmental samples.

  15. Limited level of accuracy provided by available rapid diagnosis tests for malaria enhances the need for PCR-based reference laboratories.

    Science.gov (United States)

    Rubio, J M; Buhigas, I; Subirats, M; Baquero, M; Puente, S; Benito, A

    2001-07-01

    The rise of imported malaria cases and the high fatality rate in Europe make the search for new and easy diagnostic methods necessary. Rapid diagnosis tests (RDTs) are, in part, developed to cover the lack of diagnosis experience. Unfortunately, our data suggest that the accuracy of RDTs is insufficient and could increase the number of incorrect malaria diagnoses.

  16. Very high-accuracy calibration of radiation pattern and gain of a near-field probe

    DEFF Research Database (Denmark)

    Pivnenko, Sergey; Nielsen, Jeppe Majlund; Breinbjerg, Olav

    2014-01-01

    In this paper, very high-accuracy calibration of the radiation pattern and gain of a near-field probe is described. An open-ended waveguide near-field probe has been used in a recent measurement of the C-band Synthetic Aperture Radar (SAR) Antenna Subsystem for the Sentinel 1 mission of the Europ......In this paper, very high-accuracy calibration of the radiation pattern and gain of a near-field probe is described. An open-ended waveguide near-field probe has been used in a recent measurement of the C-band Synthetic Aperture Radar (SAR) Antenna Subsystem for the Sentinel 1 mission...

  17. Bayesian modeling and inference for diagnostic accuracy and probability of disease based on multiple diagnostic biomarkers with and without a perfect reference standard.

    Science.gov (United States)

    Jafarzadeh, S Reza; Johnson, Wesley O; Gardner, Ian A

    2016-03-15

    The area under the receiver operating characteristic (ROC) curve (AUC) is used as a performance metric for quantitative tests. Although multiple biomarkers may be available for diagnostic or screening purposes, diagnostic accuracy is often assessed individually rather than in combination. In this paper, we consider the interesting problem of combining multiple biomarkers for use in a single diagnostic criterion with the goal of improving the diagnostic accuracy above that of an individual biomarker. The diagnostic criterion created from multiple biomarkers is based on the predictive probability of disease, conditional on given multiple biomarker outcomes. If the computed predictive probability exceeds a specified cutoff, the corresponding subject is allocated as 'diseased'. This defines a standard diagnostic criterion that has its own ROC curve, namely, the combined ROC (cROC). The AUC metric for cROC, namely, the combined AUC (cAUC), is used to compare the predictive criterion based on multiple biomarkers to one based on fewer biomarkers. A multivariate random-effects model is proposed for modeling multiple normally distributed dependent scores. Bayesian methods for estimating ROC curves and corresponding (marginal) AUCs are developed when a perfect reference standard is not available. In addition, cAUCs are computed to compare the accuracy of different combinations of biomarkers for diagnosis. The methods are evaluated using simulations and are applied to data for Johne's disease (paratuberculosis) in cattle.

  18. [Study on high accuracy detection of multi-component gas in oil-immerse power transformer].

    Science.gov (United States)

    Fan, Jie; Chen, Xiao; Huang, Qi-Feng; Zhou, Yu; Chen, Gang

    2013-12-01

    In order to solve the problem of low accuracy and mutual interference in multi-component gas detection, a kind of multi-component gas detection network with high accuracy was designed. A semiconductor laser with narrow bandwidth was utilized as light source and a novel long-path gas cell was also used in this system. By taking the single sine signal to modulate the spectrum of laser and using space division multiplexing (SDM) and time division multiplexing (TDM) technique, the detection of multi-component gas was achieved. The experiments indicate that the linearity relevance coefficient is 0. 99 and the measurement relative error is less than 4%. The system dynamic response time is less than 15 s, by filling a volume of multi-component gas into the gas cell gradually. The system has advantages of high accuracy and quick response, which can be used in the fault gas on-line monitoring for power transformers in real time.

  19. High-Accuracy Tracking Using Ultrawideband Signals for Enhanced Safety of Cyclists

    Directory of Open Access Journals (Sweden)

    Davide Dardari

    2017-01-01

    Full Text Available In this paper, an ultrawideband localization system to improve the cyclists’ safety is presented. The architectural solutions proposed consist of tags placed on bikes, whose positions have to be estimated, and anchors, acting as reference nodes, located at intersections and/or on vehicles. The peculiarities of the localization system in terms of accuracy and cost enable its adoption with enhanced risk assessment units situated on the infrastructure/vehicle, depending on the architecture chosen, as well as real-time warning to the road users. Experimental results reveal that the localization error, in both static and dynamic conditions, is below 50 cm in most of the cases.

  20. Analysis of Accuracy of a High-speed Mobile Platform Control System

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    The efficient manufacture technique involves a high-speed control of platform mobile system. A linear acutor is presented in this paper. The linear acutor is constructed as a linear stepper motor. However, to sustain both high accuracy and high speed for the position and speed control, A single-stack computer system is constructed and a special control algorithm is prescribed to controled the linear actuator continuously. In this paper, the nonlinear errors resulted from the magnetic saturation and the h...

  1. High-accuracy C-14 measurements for atmospheric CO2 samples by AMS

    NARCIS (Netherlands)

    Meijer, H.A.J.; Pertuisot, M.H.; van der Plicht, J.

    2006-01-01

    In this paper, we investigate how to achieve high-accuracy radiocarbon measurements by accelerator mass spectrometry (ANIS) and present measurement series (performed on archived CO2) of (CO2)-C-14 between 1985 and 1991 for Point Barrow (Alaska) and the South Pole. We report in detail the measurement

  2. Further results on the operation of high-accuracy drift chambers

    NARCIS (Netherlands)

    Breskin, A.; Charpak, G.; Gabioud, B.; Sauli, F.; Trautner, N.

    Optimization of the working parameters in the drift chambers with adjustable electric fields permits stable operation and high accuracies. Full saturation of the drift velocity leads to remarkable improvements, namely a very linear space-time correlation for perpendicular tracks, and simple

  3. From journal to headline: the accuracy of climate science news in Danish high quality newspapers

    DEFF Research Database (Denmark)

    Vestergård, Gunver Lystbæk

    2011-01-01

    analysis to examine the accuracy of Danish high quality newspapers in quoting scientific publications from 1997 to 2009. Out of 88 articles, 46 contained inaccuracies though the majority was found to be insignificant and random. The study concludes that Danish broadsheet newspapers are ‘moderately...

  4. From journal to headline: the accuracy of climate science news in Danish high quality newspapers

    DEFF Research Database (Denmark)

    Vestergård, Gunver Lystbæk

    2011-01-01

    analysis to examine the accuracy of Danish high quality newspapers in quoting scientific publications from 1997 to 2009. Out of 88 articles, 46 contained inaccuracies though the majority was found to be insignificant and random. The study concludes that Danish broadsheet newspapers are ‘moderately...

  5. The research of digital circuit system for high accuracy CCD of portable Raman spectrometer

    Science.gov (United States)

    Yin, Yu; Cui, Yongsheng; Zhang, Xiuda; Yan, Huimin

    2013-08-01

    The Raman spectrum technology is widely used for it can identify various types of molecular structure and material. The portable Raman spectrometer has become a hot direction of the spectrometer development nowadays for its convenience in handheld operation and real-time detection which is superior to traditional Raman spectrometer with heavy weight and bulky size. But there is still a gap for its measurement sensitivity between portable and traditional devices. However, portable Raman Spectrometer with Shell-Isolated Nanoparticle-Enhanced Raman Spectroscopy (SHINERS) technology can enhance the Raman signal significantly by several orders of magnitude, giving consideration in both measurement sensitivity and mobility. This paper proposed a design and implementation of driver and digital circuit for high accuracy CCD sensor, which is core part of portable spectrometer. The main target of the whole design is to reduce the dark current generation rate and increase signal sensitivity during the long integration time, and in the weak signal environment. In this case, we use back-thinned CCD image sensor from Hamamatsu Corporation with high sensitivity, low noise and large dynamic range. In order to maximize this CCD sensor's performance and minimize the whole size of the device simultaneously to achieve the project indicators, we delicately designed a peripheral circuit for the CCD sensor. The design is mainly composed with multi-voltage circuit, sequential generation circuit, driving circuit and A/D transition parts. As the most important power supply circuit, the multi-voltage circuits with 12 independent voltages are designed with reference power supply IC and set to specified voltage value by the amplifier making up the low-pass filter, which allows the user to obtain a highly stable and accurate voltage with low noise. What's more, to make our design easy to debug, CPLD is selected to generate sequential signal. The A/D converter chip consists of a correlated

  6. Surgical accuracy in high tibial osteotomy: coronal equivalence of computer navigation and gap measurement.

    Science.gov (United States)

    Schröter, S; Ihle, C; Elson, D W; Döbele, S; Stöckle, U; Ateschrang, A

    2016-11-01

    Medial opening wedge high tibial osteotomy (MOW HTO) is now a successful operation with a range of indications, requiring an individualised approach to the choice of intended correction. This manuscript introduces the concept of surgical accuracy as the absolute deviation of the achieved correction from the intended correction, where small values represent greater accuracy. Surgical accuracy is compared in a randomised controlled trial (RCT) between gap measurement and computer navigation groups. This was a prospective RCT conducted over 3 years of 120 consecutive patients with varus malalignment and medial compartment osteoarthritis, who underwent MOW HTO. All procedures were planned with digital software. Patients were randomly assigned into gap measurement or computer navigation groups. Coronal plane alignment was judged using the mechanical tibiofemoral angle (mTFA), before and after surgery. Absolute (positive) values were calculated for surgical accuracy in each individual case. There was no significant difference in the mean intended correction between groups. The achieved mTFA revealed a small under-correction in both groups. This was attributed to a failure to account for saw blade thickness (gap measurement) and over-compensation for weight bearing (computer navigation). Surgical accuracy was 1.7° ± 1.2° (gap measurement) compared to 2.1° ± 1.4° (computer navigation) without statistical significance. The difference in tibial slope increases of 2.7° ± 3.9° (gap measurement) and 2.1° ± 3.9° (computer navigation) had statistical significance (P osteotomy for individual cases. This work is clinically relevant because coronal surgical accuracy was not superior in either group. Therefore, the increased expense and surgical time associated with navigated MOW HTO is not supported, because meticulously conducted gap measurement yields equivalent surgical accuracy. I.

  7. A high-accuracy surgical augmented reality system using enhanced integral videography image overlay.

    Science.gov (United States)

    Zhang, Xinran; Chen, Guowen; Liao, Hongen

    2015-01-01

    Image guided surgery has been used in clinic to improve the surgery safety and accuracy. Augmented reality (AR) technique, which can provide intuitive image guidance, has been greatly evolved these years. As one promising approach of surgical AR systems, integral videography (IV) autostereoscopic image overlay has achieved accurate fusion of full parallax guidance into surgical scene. This paper describes an image enhanced high-accuracy IV overlay system. A flexible optical image enhancement system (IES) is designed to increase the resolution and quality of IV image. Furthermore, we introduce a novel IV rendering algorithm to promote the spatial accuracy with the consideration of distortion introduced by micro lens array. Preliminary experiments validated that the image accuracy and resolution are improved with the proposed methods. The resolution of the IV image could be promoted to 1 mm for a micro lens array with pitch of 2.32 mm and IES magnification value of 0.5. The relative deviation of accuracy in depth and lateral directions are -4.68 ± 0.83% and -9.01 ± 0.42%.

  8. Horizontal Positional Accuracy of Google Earth's High-Resolution Imagery Archive.

    Science.gov (United States)

    Potere, David

    2008-12-08

    Google Earth now hosts high-resolution imagery that spans twenty percent of the Earth's landmass and more than a third of the human population. This contemporary highresolution archive represents a significant, rapidly expanding, cost-free and largely unexploited resource for scientific inquiry. To increase the scientific utility of this archive, we address horizontal positional accuracy (georegistration) by comparing Google Earth with Landsat GeoCover scenes over a global sample of 436 control points located in 109 cities worldwide. Landsat GeoCover is an orthorectified product with known absolute positional accuracy of less than 50 meters root-mean-squared error (RMSE). Relative to Landsat GeoCover, the 436 Google Earth control points have a positional accuracy of 39.7 meters RMSE (error magnitudes range from 0.4 to 171.6 meters). The control points derived from satellite imagery have an accuracy of 22.8 meters RMSE, which is significantly more accurate than the 48 control-points based on aerial photography (41.3 meters RMSE; t-test p-value Google Earth highresolution imagery has a horizontal positional accuracy that is sufficient for assessing moderate-resolution remote sensing products across most of the world's peri-urban areas.

  9. Determining dynamical parameters of the Milky Way Galaxy based on high-accuracy radio astrometry

    Science.gov (United States)

    Honma, Mareki; Nagayama, Takumi; Sakai, Nobuyuki

    2015-08-01

    In this paper we evaluate how the dynamical structure of the Galaxy can be constrained by high-accuracy VLBI (Very Long Baseline Interferometry) astrometry such as VERA (VLBI Exploration of Radio Astrometry). We generate simulated samples of maser sources which follow the gas motion caused by a spiral or bar potential, with their distribution similar to those currently observed with VERA and VLBA (Very Long Baseline Array). We apply the Markov chain Monte Carlo analyses to the simulated sample sources to determine the dynamical parameter of the models. We show that one can successfully determine the initial model parameters if astrometric results are obtained for a few hundred sources with currently achieved astrometric accuracy. If astrometric data are available from 500 sources, the expected accuracy of R0 and Θ0 is ˜ 1% or higher, and parameters related to the spiral structure can be constrained by an error of 10% or with higher accuracy. We also show that the parameter determination accuracy is basically independent of the locations of resonances such as corotation and/or inner/outer Lindblad resonances. We also discuss the possibility of model selection based on the Bayesian information criterion (BIC), and demonstrate that BIC can be used to discriminate different dynamical models of the Galaxy.

  10. Two-step Structural Design of Mesh Antennas for High Beam Pointing Accuracy

    Science.gov (United States)

    Zhang, Shuxin; Du, Jingli; Wang, Wei; Zhang, Xinghua; Zong, Yali

    2017-05-01

    A well-designed reflector surface with high beam pointing accuracy in electromagnetic performance is of practical significance to the space application of cable mesh reflector antennas. As for space requirements, circular polarizations are widely used in spaceborne antennas, which usually lead to a beam shift for offset reflectors and influence the beam pointing accuracy. A two-step structural design procedure is proposed to overcome the beam squint phenomenon for high beam pointing accuracy design of circularly polarized offset cable mesh reflectors. A simple structural optimal design and an integrated structural electromagnetic optimization are combined to alleviate the beam squint effect of circular polarizations. It is implemented by cable pretension design and adjustment to shape the offset cable mesh surface. Besides, in order to increase the efficiency of integrated optimization, an update Broyden-Fletcher-Goldfarb-Shanno (BFGS) Hessian matrix is employed in the optimization iteration with sequential quadratic programming. A circularly polarized offset cable mesh reflector is utilized to show the feasibility and effectiveness of the proposed procedure. A high beam pointing accuracy in order of 0.0001º of electromagnetic performance is achieved.

  11. The accuracy of the lateral vertebral notch-referred pedicle screw insertion technique in subaxial cervical spine: a human cadaver study.

    Science.gov (United States)

    Luo, Jiaquan; Wu, Chunyang; Huang, Zhongren; Pan, Zhimin; Li, Zhiyun; Zhong, Junlong; Chen, Yiwei; Han, Zhimin; Cao, Kai

    2017-04-01

    This is a cadaver specimen study to confirm new pedicle screw (PS) entry point and trajectory for subaxial cervical PS insertion. To assess the accuracy of the lateral vertebral notch-referred PS insertion technique in subaxial cervical spine in cadaver cervical spine. Reported morphometric landmarks used to guide the surgeon in PS insertion show significant variability. In the previous study, we proposed a new technique (as called "notch-referred" technique) primarily based on coronal multiplane reconstruction images (CMRI) and cortical integrity after PS insertion in cadavers. However, the PS position in cadaveric cervical segment was not confirmed radiologically. Therefore, the difference between the pedicle trajectory and the PS trajectory using the notch-referred technique needs to be illuminated. Twelve cadaveric cervical spines were conducted with PS insertion using the lateral vertebral notch-referred technique. The guideline for entry point and trajectory for each vertebra was established based on the morphometric data from our previous study. After 3.5-mm diameter screw insertion, each vertebra was dissected and inspected for pedicle trajectory by CT scan. The pedicle trajectory and PS trajectory were measured and compared in axial plane. The perforation rate was assessed radiologically and was graded from ideal to unacceptable: Grade 0 = screw in pedicle; Grade I = perforation of pedicle wall less than one-fourth of the screw diameter; Grade II = perforation more than one-fourth of the screw diameter but less than one-second; Grade III = perforation more than one-second outside of the screw diameter. In addition, pedicle width between the acceptable and unacceptable screws was compared. A total of 120 pedicle screws were inserted. The perforation rate of pedicle screws was 78.3% in grade 0 (excellent PS position), 10.0% in grade I (good PS position), 8.3% in grade II (fair PS position), and 3.3% in grade III (poor PS position). The

  12. The Impact of Ionospheric Disturbances on High Accuracy Positioning in Brazil

    Science.gov (United States)

    Yang, L.; Park, J.; Susnik, A.; Aquino, M. H.; Dodson, A.

    2013-12-01

    High positioning accuracy is a key requirement to a number of applications with a high economic impact, such as precision agriculture, surveying, geodesy, land management, off-shore operations. Global Navigation Satellite Systems (GNSS) carrier phase measurement based techniques, such as Real Time Kinematic (RTK), Network-RTK (NRTK) and Precise Point Positioning (PPP), have played an important role in providing centimetre-level positioning accuracy, and become the core of the above applications. However these techniques are especially sensitive to ionospheric perturbations, in particular scintillation. Brazil sits in one of the most affected regions of the Earth and can be regarded as a test-bed for scenarios of the severe ionospheric condition. Over the Brazilian territory, the ionosphere behaves in a considerably unpredictable way and scintillation activity is very prominent, occurring especially after sunset hours. NRTK services may not be able to provide satisfactory accuracy, or even continuous positioning during strong scintillation periods. CALIBRA (Countering GNSS high Accuracy applications Limitations due to Ionospheric disturbances in BRAzil) started in late 2012 and is a project funded by the GSA (European GNSS Agency) and the European Commission under the Framework Program 7 to deliver improvements on carrier phase based high accuracy algorithms and their implementation in GNSS receivers, aiming to counter the adverse ionospheric effects over Brazil. As the first stage of this project, the ionospheric disturbances, which affect the applications of RTK, NRTK or PPP, are characterized. Typical problems include degraded positioning accuracy, difficulties in ambiguity fixing, NRTK network interpolation errors, long PPP convergence time etc. It will identify how GNSS observables and existing algorithms are degraded by ionosphere related phenomena, evaluating the impact on positioning techniques in terms of accuracy, integrity and availability. Through the

  13. a Study on Producing Highly Reliabile Reference Data Sets for Global Land Cover Validation

    Science.gov (United States)

    Soyama, N.; Muramatsu, K.; Daigo, M.; Ochiai, F.; Fujiwara, N.

    2016-06-01

    Validating the accuracy of land cover products using a reliable reference dataset is an important task. A reliable reference dataset is produced with information derived from ground truth data. Recently, the amount of ground truth data derived from information collected by volunteers has been increasing globally. The acquisition of volunteer-based reference data demonstrates great potential. However information given by volunteers is limited useful vegetation information to produce a complete reference dataset based on the plant functional type (PFT) with five specialized forest classes. In this study, we examined the availability and applicability of FLUXNET information to produce reference data with higher levels of reliability. FLUXNET information was useful especially for forest classes for interpretation in comparison with the reference dataset using information given by volunteers.

  14. Hybrid head-tracker being examined for the high-accuracy attack rotorcraft market

    Science.gov (United States)

    Blanton, Buddy

    2002-08-01

    The need for the helmet-mounted display (HMD) to present flight, navigation, and weapon information in the pilot's line-of-sight has continued to rise as helicopter missions increase in complexity. To obtain spatial correlation of the direction of the head line-of-sight and pilotage imagery generated from helicopter-mounted sensors, it is necessary to slave the sensors to the head motion. To accomplish this task, a head-tracking system (HTS) must be incorporated into the HMD. There are a variety of techniques that could be applied for locating the position and attitude of a helmet-mounted display. Regardless of the technology, an HTS must provide defined measurements of accuracy. System parameters include motion box size, angular range, pointing angle accuracy, pointing angle resolution, update rate, and slew rate. This paper focuses on a hybrid tracker implementation in which a combination of optical and inertial tracking using strap-down gyros is preferred. Specifically, this tracker implementation is being examined for the high-accuracy attack rotorcraft market which requires a high degree of accuracy. The performance and resultant cost of the tracker components are determined by the specific needs of the intended application. The paper will also indicate how the various requirements drive the cost, configuration, and performance of the resultant hybrid head-tracker.

  15. About accuracy of the discrimination parameter estimation for the dual high-energy method

    Science.gov (United States)

    Osipov, S. P.; Chakhlov, S. V.; Osipov, O. S.; Shtein, A. M.; Strugovtsev, D. V.

    2015-04-01

    A set of the mathematical formulas to estimate the accuracy of discrimination parameters for two implementations of the dual high energy method - by the effective atomic number and by the level lines is given. The hardware parameters which influenced on the accuracy of the discrimination parameters are stated. The recommendations to form the structure of the high energy X-ray radiation impulses are formulated. To prove the applicability of the proposed procedure there were calculated the statistical errors of the discrimination parameters for the cargo inspection system of the Tomsk polytechnic university on base of the portable betatron MIB-9. The comparison of the experimental estimations and the theoretical ones of the discrimination parameter errors was carried out. It proved the practical applicability of the algorithm to estimate the discrimination parameter errors for the dual high energy method.

  16. High accuracy digital aging monitor based on PLL-VCO circuit

    Science.gov (United States)

    Yuejun, Zhang; Zhidi, Jiang; Pengjun, Wang; Xuelong, Zhang

    2015-01-01

    As the manufacturing process is scaled down to the nanoscale, the aging phenomenon significantly affects the reliability and lifetime of integrated circuits. Consequently, the precise measurement of digital CMOS aging is a key aspect of nanoscale aging tolerant circuit design. This paper proposes a high accuracy digital aging monitor using phase-locked loop and voltage-controlled oscillator (PLL-VCO) circuit. The proposed monitor eliminates the circuit self-aging effect for the characteristic of PLL, whose frequency has no relationship with circuit aging phenomenon. The PLL-VCO monitor is implemented in TSMC low power 65 nm CMOS technology, and its area occupies 303.28 × 298.94 μm2. After accelerating aging tests, the experimental results show that PLL-VCO monitor improves accuracy about high temperature by 2.4% and high voltage by 18.7%.

  17. High accuracy acoustic relative humidity measurement in duct flow with air.

    Science.gov (United States)

    van Schaik, Wilhelm; Grooten, Mart; Wernaart, Twan; van der Geld, Cees

    2010-01-01

    An acoustic relative humidity sensor for air-steam mixtures in duct flow is designed and tested. Theory, construction, calibration, considerations on dynamic response and results are presented. The measurement device is capable of measuring line averaged values of gas velocity, temperature and relative humidity (RH) instantaneously, by applying two ultrasonic transducers and an array of four temperature sensors. Measurement ranges are: gas velocity of 0-12 m/s with an error of ± 0.13 m/s, temperature 0-100 °C with an error of ± 0.07 °C and relative humidity 0-100% with accuracy better than 2 % RH above 50 °C. Main advantage over conventional humidity sensors is the high sensitivity at high RH at temperatures exceeding 50 °C, with accuracy increasing with increasing temperature. The sensors are non-intrusive and resist highly humid environments.

  18. Accuracy of a low priced liquid-based method for cervical cytology in 632 women referred for colposcopy after a positive Pap smear.

    Science.gov (United States)

    van Hemel, B M; Buikema, H J; Groen, H; Suurmeijer, A J H

    2009-08-01

    The aim of this quality controlling study was to determine the accuracy of liquid-based cytology (LBC) with the Turbitec cytocentrifuge technique. Cervical smears of 632 women, who were referred to our CIN outpatient department, after at least two smears with ASCUS or higher were evaluated and compared with the histological outcome. In 592 cases the smears revealed abnormalities of squamous epithelium, and in 40 cases the abnormalities of glandular epithelium. In the group of squamous epithelium abnormalities, the sensitivity for LSIL was 39.7% and the specificity was 89.2%; for the LSIL+ group, these values were 89.4% and 91.4%, respectively. For HSIL the sensitivity was 68.3% and the specificity 92.8%, for the HSIL+ group 82.3% and 92.3%, respectively. The ASCUS rate was low (2.4%). The Turbitec cytocentrifuge method was proved to be a very good LBC method for cervical smears. Because of a comparable accuracy together with a lower price, this LBC method outweighs commercial alternatives.

  19. High Mass Accuracy and High Mass Resolving Power FT-ICR Secondary Ion Mass Spectrometry for Biological Tissue Imaging

    CERN Document Server

    Smith, Donald F; Leach, Franklin E; Robinson, Errol W; Paša-Tolić, Ljiljana; Heeren, Ron M A

    2013-01-01

    Biological tissue imaging by secondary ion mass spectrometry has seen rapid development with the commercial availability of polyatomic primary ion sources. Endogenous lipids and other small bio-molecules can now be routinely mapped on the sub-micrometer scale. Such experiments are typically performed on time-of-flight mass spectrometers for high sensitivity and high repetition rate imaging. However, such mass analyzers lack the mass resolving power to ensure separation of isobaric ions and the mass accuracy for elemental formula assignment based on exact mass measurement. We have recently reported a secondary ion mass spectrometer with the combination of a C60 primary ion gun with a Fourier transform ion cyclotron resonance mass spectrometer (FT-ICR MS) for high mass resolving power, high mass measurement accuracy and tandem mass spectrometry capabilities. In this work, high specificity and high sensitivity secondary ion FT-ICR MS was applied to chemical imaging of biological tissue. An entire rat brain tissu...

  20. Results of error correction techniques applied on two high accuracy coordinate measuring machines

    Energy Technology Data Exchange (ETDEWEB)

    Pace, C.; Doiron, T.; Stieren, D.; Borchardt, B.; Veale, R. (Sandia National Labs., Albuquerque, NM (USA); National Inst. of Standards and Technology, Gaithersburg, MD (USA))

    1990-01-01

    The Primary Standards Laboratory at Sandia National Laboratories (SNL) and the Precision Engineering Division at the National Institute of Standards and Technology (NIST) are in the process of implementing software error correction on two nearly identical high-accuracy coordinate measuring machines (CMMs). Both machines are Moore Special Tool Company M-48 CMMs which are fitted with laser positioning transducers. Although both machines were manufactured to high tolerance levels, the overall volumetric accuracy was insufficient for calibrating standards to the levels both laboratories require. The error mapping procedure was developed at NIST in the mid 1970's on an earlier but similar model. The error mapping procedure was originally very complicated and did not make any assumptions about the rigidness of the machine as it moved, each of the possible error motions was measured at each point of the error map independently. A simpler mapping procedure was developed during the early 1980's which assumed rigid body motion of the machine. This method has been used to calibrate lower accuracy machines with a high degree of success and similar software correction schemes have been implemented by many CMM manufacturers. The rigid body model has not yet been used on highly repeatable CMMs such as the M48. In this report we present early mapping data for the two M48 CMMs. The SNL CMM was manufactured in 1985 and has been in service for approximately four years, whereas the NIST CMM was delivered in early 1989. 4 refs., 5 figs.

  1. A three axis turntable's online initial state measurement method based on the high-accuracy laser gyro SINS

    Science.gov (United States)

    Gao, Chunfeng; Wei, Guo; Wang, Qi; Xiong, Zhenyu; Wang, Qun; Long, Xingwu

    2016-10-01

    As an indispensable equipment in inertial technology tests, the three-axis turntable is widely used in the calibration of various types inertial navigation systems (INS). In order to ensure the calibration accuracy of INS, we need to accurately measure the initial state of the turntable. However, the traditional measuring method needs a lot of exterior equipment (such as level instrument, north seeker, autocollimator, etc.), and the test processing is complex, low efficiency. Therefore, it is relatively difficult for the inertial measurement equipment manufacturers to realize the self-inspection of the turntable. Owing to the high precision attitude information provided by the laser gyro strapdown inertial navigation system (SINS) after fine alignment, we can use it as the attitude reference of initial state measurement of three-axis turntable. For the principle that the fixed rotation vector increment is not affected by measuring point, we use the laser gyro INS and the encoder of the turntable to provide the attitudes of turntable mounting plat. Through this way, the high accuracy measurement of perpendicularity error and initial attitude of the three-axis turntable has been achieved.

  2. RNA secondary structure modeling at consistent high accuracy using differential SHAPE.

    Science.gov (United States)

    Rice, Greggory M; Leonard, Christopher W; Weeks, Kevin M

    2014-06-01

    RNA secondary structure modeling is a challenging problem, and recent successes have raised the standards for accuracy, consistency, and tractability. Large increases in accuracy have been achieved by including data on reactivity toward chemical probes: Incorporation of 1M7 SHAPE reactivity data into an mfold-class algorithm results in median accuracies for base pair prediction that exceed 90%. However, a few RNA structures are modeled with significantly lower accuracy. Here, we show that incorporating differential reactivities from the NMIA and 1M6 reagents--which detect noncanonical and tertiary interactions--into prediction algorithms results in highly accurate secondary structure models for RNAs that were previously shown to be difficult to model. For these RNAs, 93% of accepted canonical base pairs were recovered in SHAPE-directed models. Discrepancies between accepted and modeled structures were small and appear to reflect genuine structural differences. Three-reagent SHAPE-directed modeling scales concisely to structurally complex RNAs to resolve the in-solution secondary structure analysis problem for many classes of RNA.

  3. A fast and high accuracy numerical simulation algorithm of the polymer spherulite at the mesoscale Level

    Science.gov (United States)

    Liu, Yongzhi; Geng, Tie; (Tom Turng, Lih-Sheng; Liu, Chuntai; Cao, Wei; Shen, Changyu

    2017-09-01

    In the multiscale numerical simulation of polymer crystallization during the processing period, flow and temperature of the polymer melt are simulated on the macroscale level, while nucleation and growth of the spherulite are simulated at the mesoscale level. As a part of the multiscale simulation, the meso-simulation requires a fast solving speed because the meso-simulation software must be run several times in every macro-element at each macro-step. Meanwhile, the accuracy of the calculation results is also very important. It is known that the simulation geometry of crystallization includes planar (2D) and three-dimensional space (3D). The 3D calculations are more accurate but more expensive because of the long CPU time consumed. On the contrary, 2D calculations are always much faster but lower in accuracy. To reach the desirable speed and high accuracy at the same time, an algorithm is presented, in which the Delesse law coupled with the Monte Carlo method and pixel method are employed to simulate the nucleation, growth, and impingement of the polymer spherulite at the mesoscale level. Based on this algorithm, a software is developed with the Visual C++ language, and its numerical examples’ results prove that the solving speed of this algorithm is as fast as the 2D classical simulation and the calculation accuracy is at the same level as the 3D simulation.

  4. High Accuracy Gravitational Waveforms from Black Hole Binary Inspirals Using OpenCL

    CERN Document Server

    McKennon, Justin; Khanna, Gaurav

    2012-01-01

    There is a strong need for high-accuracy and efficient modeling of extreme-mass-ratio binary black hole systems because these are strong sources of gravitational waves that would be detected by future observatories. In this article, we present sample results from our Teukolsky EMRI code: a time-domain Teukolsky equation solver (a linear, hyperbolic, partial differential equation solver using finite-differencing), that takes advantage of several mathematical and computational enhancements to efficiently generate long-duration and high-accuracy EMRI waveforms. We emphasize here the computational advances made in the context of this code. Currently there is considerable interest in making use of many-core processor architectures, such as Nvidia and AMD graphics processing units (GPUs) for scientific computing. Our code uses the Open Computing Language (OpenCL) for taking advantage of the massive parallelism offered by modern GPU architectures. We present the performance of our Teukolsky EMRI code on multiple mod...

  5. Cavity ring-down technique for measurement of reflectivity of high reflectivity mirrors with high accuracy

    Indian Academy of Sciences (India)

    G Sridhar; Sandeep K Agarwalla; Sunita Singh; L M Gantayet

    2010-12-01

    A simple, accurate and reliable method for measuring the reflectivity of laser-grade mirrors ( > 99.5 %) based on cavity ring-down (CRD) technique has been success-fully demonstrated in our laboratory using a pulsed Nd:YAG laser. A fast photomultiplier tube with an oscilloscope was used to detect and analyse the CRD signal. The cavity decay times were measured for three cavities formed by a combination of three mirror pairs. The absolute reflectivities 1, 2, 3 were determined to be 99.94%, 99.63%, 99.52% at normal incidence. The reflectivity of mirrors is measured to an accuracy of 0.01%.

  6. A Smart High Accuracy Silicon Piezoresistive Pressure Sensor Temperature Compensation System

    Directory of Open Access Journals (Sweden)

    Guanwu Zhou

    2014-07-01

    Full Text Available Theoretical analysis in this paper indicates that the accuracy of a silicon piezoresistive pressure sensor is mainly affected by thermal drift, and varies nonlinearly with the temperature. Here, a smart temperature compensation system to reduce its effect on accuracy is proposed. Firstly, an effective conditioning circuit for signal processing and data acquisition is designed. The hardware to implement the system is fabricated. Then, a program is developed on LabVIEW which incorporates an extreme learning machine (ELM as the calibration algorithm for the pressure drift. The implementation of the algorithm was ported to a micro-control unit (MCU after calibration in the computer. Practical pressure measurement experiments are carried out to verify the system’s performance. The temperature compensation is solved in the interval from −40 to 85 °C. The compensated sensor is aimed at providing pressure measurement in oil-gas pipelines. Compared with other algorithms, ELM acquires higher accuracy and is more suitable for batch compensation because of its higher generalization and faster learning speed. The accuracy, linearity, zero temperature coefficient and sensitivity temperature coefficient of the tested sensor are 2.57% FS, 2.49% FS, 8.1 × 10−5/°C and 29.5 × 10−5/°C before compensation, and are improved to 0.13%FS, 0.15%FS, 1.17 × 10−5/°C and 2.1 × 10−5/°C respectively, after compensation. The experimental results demonstrate that the proposed system is valid for the temperature compensation and high accuracy requirement of the sensor.

  7. High Mass Accuracy and High Mass Resolving Power FT-ICR Secondary Ion Mass Spectrometry for Biological Tissue Imaging

    Energy Technology Data Exchange (ETDEWEB)

    Smith, Donald F.; Kiss, Andras; Leach, Franklin E.; Robinson, Errol W.; Pasa-Tolic, Ljiljana; Heeren, Ronald M.

    2013-07-01

    Biological tissue imaging by secondary ion mass spectrometry has seen rapid development with the commercial availability of polyatomic primary ion sources. Endogenous lipids and other small bio-molecules can now be routinely mapped on the micrometer scale. Such experiments are typically performed on time-of-flight mass spectrometers for high sensitivity and high repetition rate imaging. However, such mass analyzers lack the mass resolving power to ensure separation of isobaric ions and the mass accuracy for exact mass elemental formula assignment. We have recently reported a secondary ion mass spectrometer with the combination of a C60 primary ion gun with a Fourier transform ion cyclotron resonance mass spectrometer (FT-ICR MS) for high mass resolving power, high mass measurement accuracy and tandem mass spectrometry capabilities. In this work, high specificity and high sensitivity secondary ion FT-ICR MS was applied to chemical imaging of biological tissue. An entire rat brain tissue was measured with 150 μm spatial resolution (75 μm primary ion spot size) with mass resolving power (m/Δm50%) of 67,500 (at m/z 750) and root-mean-square measurement accuracy less than two parts-per-million for intact phospholipids, small molecules and fragments. For the first time, ultra-high mass resolving power SIMS has been demonstrated, with m/Δm50% > 3,000,000. Higher spatial resolution capabilities of the platform were tested at a spatial resolution of 20 μm. The results represent order of magnitude improvements in mass resolving power and mass measurement accuracy for SIMS imaging and the promise of the platform for ultra-high mass resolving power and high spatial resolution imaging.

  8. Accuracy of GPS devices for measuring high-intensity running in field-based team sports.

    Science.gov (United States)

    Rampinini, E; Alberti, G; Fiorenza, M; Riggio, M; Sassi, R; Borges, T O; Coutts, A J

    2015-01-01

    We compared the accuracy of 2 GPS systems with different sampling rates for the determination of distances covered at high-speed and metabolic power derived from a combination of running speed and acceleration. 8 participants performed 56 bouts of shuttle intermittent running wearing 2 portable GPS devices (SPI-Pro, GPS-5 Hz and MinimaxX, GPS-10 Hz). The GPS systems were compared with a radar system as a criterion measure. The variables investigated were: total distance (TD), high-speed distance (HSR>4.17 m·s(-1)), very high-speed distance (VHSR>5.56 m·s(-1)), mean power (Pmean), high metabolic power (HMP>20 W·kg(-1)) and very high metabolic power (VHMP>25 W·kg(-1)). GPS-5 Hz had low error for TD (2.8%) and Pmean (4.5%), while the errors for the other variables ranged from moderate to high (7.5-23.2%). GPS-10 Hz demonstrated a low error for TD (1.9%), HSR (4.7%), Pmean (2.4%) and HMP (4.5%), whereas the errors for VHSR (10.5%) and VHMP (6.2%) were moderate. In general, GPS accuracy increased with a higher sampling rate, but decreased with increasing speed of movement. Both systems could be used for calculating TD and Pmean, but they cannot be used interchangeably. Only GPS-10 Hz demonstrated a sufficient level of accuracy for quantifying distance covered at higher speeds or time spent at very high power. © Georg Thieme Verlag KG Stuttgart · New York.

  9. Making high-accuracy null depth measurements for the LBTI exozodi survey

    Science.gov (United States)

    Mennesson, Bertrand; Defrère, Denis; Nowak, Matthias; Hinz, Philip; Millan-Gabet, Rafael; Absil, Olivier; Bailey, Vanessa; Bryden, Geoffrey; Danchi, William; Kennedy, Grant M.; Marion, Lindsay; Roberge, Aki; Serabyn, Eugene; Skemer, Andy J.; Stapelfeldt, Karl; Weinberger, Alycia J.; Wyatt, Mark

    2016-08-01

    The characterization of exozodiacal light emission is both important for the understanding of planetary systems evolution and for the preparation of future space missions aiming to characterize low mass planets in the habitable zone of nearby main sequence stars. The Large Binocular Telescope Interferometer (LBTI) exozodi survey aims at providing a ten-fold improvement over current state of the art, measuring dust emission levels down to a typical accuracy of 12 zodis per star, for a representative ensemble of 30+ high priority targets. Such measurements promise to yield a final accuracy of about 2 zodis on the median exozodi level of the targets sample. Reaching a 1 σ measurement uncertainty of 12 zodis per star corresponds to measuring interferometric cancellation ("null") levels, i.e visibilities at the few 100 ppm uncertainty level. We discuss here the challenges posed by making such high accuracy mid-infrared visibility measurements from the ground and present the methodology we developed for achieving current best levels of 500 ppm or so. We also discuss current limitations and plans for enhanced exozodi observations over the next few years at LBTI.

  10. Optical System Error Analysis and Calibration Method of High-Accuracy Star Trackers

    Directory of Open Access Journals (Sweden)

    Zheng You

    2013-04-01

    Full Text Available The star tracker is a high-accuracy attitude measurement device widely used in spacecraft. Its performance depends largely on the precision of the optical system parameters. Therefore, the analysis of the optical system parameter errors and a precise calibration model are crucial to the accuracy of the star tracker. Research in this field is relatively lacking a systematic and universal analysis up to now. This paper proposes in detail an approach for the synthetic error analysis of the star tracker, without the complicated theoretical derivation. This approach can determine the error propagation relationship of the star tracker, and can build intuitively and systematically an error model. The analysis results can be used as a foundation and a guide for the optical design, calibration, and compensation of the star tracker. A calibration experiment is designed and conducted. Excellent calibration results are achieved based on the calibration model. To summarize, the error analysis approach and the calibration method are proved to be adequate and precise, and could provide an important guarantee for the design, manufacture, and measurement of high-accuracy star trackers.

  11. High Accuracy Attitude Control System Design for Satellite with Flexible Appendages

    Directory of Open Access Journals (Sweden)

    Wenya Zhou

    2014-01-01

    Full Text Available In order to realize the high accuracy attitude control of satellite with flexible appendages, attitude control system consisting of the controller and structural filter was designed. When the low order vibration frequency of flexible appendages is approximating the bandwidth of attitude control system, the vibration signal will enter the control system through measurement device to bring impact on the accuracy or even the stability. In order to reduce the impact of vibration of appendages on the attitude control system, the structural filter is designed in terms of rejecting the vibration of flexible appendages. Considering the potential problem of in-orbit frequency variation of the flexible appendages, the design method for the adaptive notch filter is proposed based on the in-orbit identification technology. Finally, the simulation results are given to demonstrate the feasibility and effectiveness of the proposed design techniques.

  12. High-accuracy determination of the neutron flux at n{sub T}OF

    Energy Technology Data Exchange (ETDEWEB)

    Barbagallo, M.; Colonna, N.; Mastromarco, M.; Meaze, M.; Tagliente, G.; Variale, V. [Sezione di Bari, INFN, Bari (Italy); Guerrero, C.; Andriamonje, S.; Boccone, V.; Brugger, M.; Calviani, M.; Cerutti, F.; Chin, M.; Ferrari, A.; Kadi, Y.; Losito, R.; Versaci, R.; Vlachoudis, V. [European Organization for Nuclear Research (CERN), Geneva (Switzerland); Tsinganis, A. [European Organization for Nuclear Research (CERN), Geneva (Switzerland); National Technical University of Athens (NTUA), Athens (Greece); Tarrio, D.; Duran, I.; Leal-Cidoncha, E.; Paradela, C. [Universidade de Santiago de Compostela, Santiago (Spain); Altstadt, S.; Goebel, K.; Langer, C.; Reifarth, R.; Schmidt, S.; Weigand, M. [Johann-Wolfgang-Goethe Universitaet, Frankfurt (Germany); Andrzejewski, J.; Marganiec, J.; Perkowski, J. [Uniwersytet Lodzki, Lodz (Poland); Audouin, L.; Leong, L.S.; Tassan-Got, L. [Centre National de la Recherche Scientifique/IN2P3 - IPN, Orsay (France); Becares, V.; Cano-Ott, D.; Garcia, A.R.; Gonzalez-Romero, E.; Martinez, T.; Mendoza, E. [Centro de Investigaciones Energeticas Medioambientales y Tecnologicas (CIEMAT), Madrid (Spain); Becvar, F.; Krticka, M.; Kroll, J.; Valenta, S. [Charles University, Prague (Czech Republic); Belloni, F.; Fraval, K.; Gunsing, F.; Lampoudis, C.; Papaevangelou, T. [Commissariata l' Energie Atomique (CEA) Saclay - Irfu, Gif-sur-Yvette (France); Berthoumieux, E.; Chiaveri, E. [European Organization for Nuclear Research (CERN), Geneva (Switzerland); Commissariata l' Energie Atomique (CEA) Saclay - Irfu, Gif-sur-Yvette (France); Billowes, J.; Ware, T.; Wright, T. [University of Manchester, Manchester (United Kingdom); Bosnar, D.; Zugec, P. [University of Zagreb, Department of Physics, Faculty of Science, Zagreb (Croatia); Calvino, F.; Cortes, G.; Gomez-Hornillos, M.B.; Riego, A. [Universitat Politecnica de Catalunya, Barcelona (Spain); Carrapico, C.; Goncalves, I.F.; Sarmento, R.; Vaz, P. [Universidade Tecnica de Lisboa, Instituto Tecnologico e Nuclear, Instituto Superior Tecnico, Lisboa (Portugal); Cortes-Giraldo, M.A.; Praena, J.; Quesada, J.M.; Sabate-Gilarte, M. [Universidad de Sevilla, Sevilla (Spain); Diakaki, M.; Karadimos, D.; Kokkoris, M.; Vlastou, R. [National Technical University of Athens (NTUA), Athens (Greece); Domingo-Pardo, C.; Giubrone, G.; Tain, J.L. [CSIC-Universidad de Valencia, Instituto de Fisica Corpuscular, Valencia (Spain); Dressler, R.; Kivel, N.; Schumann, D.; Steinegger, P. [Paul Scherrer Institut, Villigen PSI (Switzerland); Dzysiuk, N.; Mastinu, P.F. [Laboratori Nazionali di Legnaro, INFN, Rome (Italy); Eleftheriadis, C.; Manousos, A. [Aristotle University of Thessaloniki, Thessaloniki (Greece); Ganesan, S.; Gurusamy, P.; Saxena, A. [Bhabha Atomic Research Centre (BARC), Mumbai (IN); Griesmayer, E.; Jericha, E.; Leeb, H. [Technische Universitaet Wien, Atominstitut, Wien (AT); Hernandez-Prieto, A. [European Organization for Nuclear Research (CERN), Geneva (CH); Universitat Politecnica de Catalunya, Barcelona (ES); Jenkins, D.G.; Vermeulen, M.J. [University of York, Heslington, York (GB); Kaeppeler, F. [Institut fuer Kernphysik, Karlsruhe Institute of Technology, Campus Nord, Karlsruhe (DE); Koehler, P. [Oak Ridge National Laboratory (ORNL), Oak Ridge (US); Lederer, C. [Johann-Wolfgang-Goethe Universitaet, Frankfurt (DE); University of Vienna, Faculty of Physics, Vienna (AT); Massimi, C.; Mingrone, F.; Vannini, G. [Universita di Bologna (IT); INFN, Sezione di Bologna, Dipartimento di Fisica, Bologna (IT); Mengoni, A.; Ventura, A. [Agenzia nazionale per le nuove tecnologie, l' energia e lo sviluppo economico sostenibile (ENEA), Bologna (IT); Milazzo, P.M. [Sezione di Trieste, INFN, Trieste (IT); Mirea, M. [Horia Hulubei National Institute of Physics and Nuclear Engineering - IFIN HH, Bucharest - Magurele (RO); Mondalaers, W.; Plompen, A.; Schillebeeckx, P. [Institute for Reference Materials and Measurements, European Commission JRC, Geel (BE); Pavlik, A.; Wallner, A. [University of Vienna, Faculty of Physics, Vienna (AT); Rauscher, T. [University of Basel, Department of Physics and Astronomy, Basel (CH); Roman, F. [European Organization for Nuclear Research (CERN), Geneva (CH); Horia Hulubei National Institute of Physics and Nuclear Engineering - IFIN HH, Bucharest - Magurele (RO); Rubbia, C. [European Organization for Nuclear Research (CERN), Geneva (CH); Laboratori Nazionali del Gran Sasso dell' INFN, Assergi (AQ) (IT); Weiss, C. [European Organization for Nuclear Research (CERN), Geneva (CH); Johann-Wolfgang-Goethe Universitaet, Frankfurt (DE)

    2013-12-15

    The neutron flux of the n{sub T}OF facility at CERN was measured, after installation of the new spallation target, with four different systems based on three neutron-converting reactions, which represent accepted cross sections standards in different energy regions. A careful comparison and combination of the different measurements allowed us to reach an unprecedented accuracy on the energy dependence of the neutron flux in the very wide range (thermal to 1 GeV) that characterizes the n{sub T}OF neutron beam. This is a pre-requisite for the high accuracy of cross section measurements at n{sub T}OF. An unexpected anomaly in the neutron-induced fission cross section of {sup 235}U is observed in the energy region between 10 and 30keV, hinting at a possible overestimation of this important cross section, well above currently assigned uncertainties. (orig.)

  13. Study of efficient high-power, high-energy neutral beams for the Reference Mirror Reactor

    Energy Technology Data Exchange (ETDEWEB)

    Fink, J.H.; Barr, W.L.; Hamilton, G.W.

    1976-11-11

    An injector design for the Reference Mirror Reactor is described which uses negative ions created by charge-exchange in a cesium vapor cell and neutralized by photodetachment. Some of the innovations discussed include a continuously operating cathode for an LBL/LLL ion source, a negative ion beam line with cooled grids, a high voltage accelerator configuration with insulators shielded from the neutron and gamma flux, and cryopanels which continuously cycle between pumping and outgassing modes.

  14. Increasing the Accuracy in the Measurement of the Minor Isotopes of Uranium: Care in Selection of Reference Materials, Baselines and Detector Calibration

    Science.gov (United States)

    Poths, J.; Koepf, A.; Boulyga, S. F.

    2008-12-01

    The minor isotopes of uranium (U-233, U-234, U-236) are increasingly useful for tracing a variety of processes: movement of anthropogenic nuclides in the environment (ref 1), sources of uranium ores (ref 2), and nuclear material attribution (ref 3). We report on improved accuracy for U-234/238 and U-236/238 by supplementing total evaporation protocol TIMS measurement on Faraday detectors (ref 4)with multiplier measurement for the minor isotopes. Measurement of small signals on Faraday detectors alone is limited by noise floors of the amplifiers and accurate measurement of the baseline offsets. The combined detector approach improves the reproducibility to better than ±1% (relative) for the U-234/238 at natural abundance, and yields a detection limit for U-236/U-238 of <0.2 ppm. We have quantified contribution of different factors to the uncertainties associated with these peak jumping measurement on a single detector, with an aim of further improvement. The uncertainties in the certified values for U-234 and U-236 in the uranium standard NBS U005, if used for mass bias correction, dominates the uncertainty in their isotopic ratio measurements. Software limitations in baseline measurement drives the detection limit for the U-236/U-238 ratio. This is a topic for discussion with the instrument manufacturers. Finally, deviation from linearity of the response of the electron multiplier with count rate limits the accuracy and reproducibility of these minor isotope measurements. References: (1) P. Steier et al(2008) Nuc Inst Meth(B), 266, 2246-2250. (2) E. Keegan et al (2008) Appl Geochem 23, 765-777. (3) K. Mayer et al (1998) IAEA-CN-98/11, in Advances in Destructive and Non-destructive Analysis for Environmental Monitoring and Nuclear Forensics. (4) S. Richter and S. Goldberg(2003) Int J Mass Spectrom, 229, 181-197.

  15. High-temperature potentiometric oxygen sensor with internal reference

    Energy Technology Data Exchange (ETDEWEB)

    Routbort, Jules L. (Hinsdale, IL); Singh, Dileep (Naperville, IL); Dutta, Prabir K. (Worthington, OH); Ramasamy, Ramamoorthy (North Royalton, OH); Spirig, John V. (Columbus, OH); Akbar, Sheikh (Hilliard, OH)

    2011-11-15

    A compact oxygen sensor is provided, comprising a mixture of metal and metal oxide an enclosure containing said mixture, said enclosure capable of isolating said mixture from an environment external of said enclosure, and a first wire having a first end residing within the enclosure and having a second end exposed to the environment. Also provided is a method for the fabrication of an oxygen sensor, the method comprising confining a metal-metal oxide solid mixture to a container which consists of a single material permeable to oxygen ions, supplying an electrical conductor having a first end and a second end, whereby the first end resides inside the container as a reference (PO.sub.2).sup.ref, and the second end resides outside the container in the atmosphere where oxygen partial pressure (PO.sub.2).sup.ext is to be measured, and sealing the container with additional single material such that grain boundary sliding occurs between grains of the single material and grains of the additional single material.

  16. The accuracy of 3D image navigation with a cutaneously fixed dynamic reference frame in minimally invasive transforaminal lumbar interbody fusion.

    Science.gov (United States)

    Cho, Ji Young; Chan, Chee Keong; Lee, Sang-Ho; Lee, Ho-Yeon

    2012-01-01

    In contrast to preoperative image-based 3D navigation systems, which require surgeon-dependent registration, an intraoperative cone-beam computed tomography (cb-CT) image-based 3D navigation system allows automatic registration during the acquisition of 3D images intraoperatively. Thus, the need for spinal exposure for point matching is obviated, making a cb-CT image-based navigation system ideal for use in minimally invasive spinal procedures. Conventionally, the dynamic reference frame (DRF) is mounted to an adjacent spinous process or iliac bone through a separate incision. However, the close proximity of the DRF to the surgical area may result in its interfering with the surgical procedure or causing streak artifacts on the navigation images. Cutaneous placement of the DRF overlying the sacral hiatus is one possible solution to these problems, but such a placement does not provide a solid bony fixation point and is distant from the surgical area, both of which factors may hinder the accuracy of the navigation. The purpose of this study was to evaluate the accuracy of a novel idea for DRF placement in a series of mini-open transforaminal lumbar interbody fusion (TLIF) procedures performed with intraoperative cb-CT image-based 3D navigation. From June 2009 to December 2009, 20 patients underwent mini-open TLIF for a total 82 pedicle screws placed in the lumbar spine with cutaneous placement of the DRF overlying the sacral hiatus. The pedicle screws were inserted under navigational guidance using cb-CT data acquired intraoperatively with a Medtronic O-arm. Screw positions were subsequently checked with a final intraoperative cb-CT scan. Nineteen patients underwent single-level fusion (8 at L4-5, 6 at L5-S1, 4 at L3-4, and 1 at L2-3) and one patient underwent two-level fusion (from L3-5). There were 4 (4.9%) pedicle perforations greater than 2 mm out of the 82 pedicle screw insertions in the 20 patients. Two of these breached screws were repositioned and

  17. High Sensitivity Optomechanical Reference Accelerometer over 10 kHz

    Science.gov (United States)

    2014-06-05

    characterizing fast mechanical dynamics and piezo -electric devices, but typically not both. Yet extremely high resolution maintained over large...applying a ringdown technique in vacuum. To this end, we used a piezo -shaker to excite the oscillator at its resonance frequency and measured the...exponential decay response. The resonance peak was determined by spectral analysis and then honed in by a high resolution function generator driving the piezo

  18. High-Accuracy Elevation Data at Large Scales from Airborne Single-Pass SAR Interferometry

    Directory of Open Access Journals (Sweden)

    Guy Jean-Pierre Schumann

    2016-01-01

    Full Text Available Digital elevation models (DEMs are essential data sets for disaster risk management and humanitarian relief services as well as many environmental process models. At present, on the hand, globally available DEMs only meet the basic requirements and for many services and modeling studies are not of high enough spatial resolution and lack accuracy in the vertical. On the other hand, LiDAR-DEMs are of very high spatial resolution and great vertical accuracy but acquisition operations can be very costly for spatial scales larger than a couple of hundred square km and also have severe limitations in wetland areas and under cloudy and rainy conditions. The ideal situation would thus be to have a DEM technology that allows larger spatial coverage than LiDAR but without compromising resolution and vertical accuracy and still performing under some adverse weather conditions and at a reasonable cost. In this paper, we present a novel single pass In-SAR technology for airborne vehicles that is cost-effective and can generate DEMs with a vertical error of around 0.3 m for an average spatial resolution of 3 m. To demonstrate this capability, we compare a sample single-pass In-SAR Ka-band DEM of the California Central Valley from the NASA/JPL airborne GLISTIN-A to a high-resolution LiDAR DEM. We also perform a simple sensitivity analysis to floodplain inundation. Based on the findings of our analysis, we argue that this type of technology can and should be used to replace large regions of globally available lower resolution DEMs, particularly in coastal, delta and floodplain areas where a high number of assets, habitats and lives are at risk from natural disasters. We conclude with a discussion on requirements, advantages and caveats in terms of instrument and data processing.

  19. High-Accuracy Elevation Data at Large Scales from Airborne Single-Pass SAR Interferometry

    Science.gov (United States)

    Schumann, Guy; Moller, Delwyn; Mentgen, Felix

    2015-12-01

    Digital elevation models (DEMs) are essential data sets for disaster risk management and humanitarian relief services as well as many environmental process models. At present, on the hand, globally available DEMs only meet the basic requirements and for many services and modeling studies are not of high enough spatial resolution and lack accuracy in the vertical. On the other hand, LiDAR-DEMs are of very high spatial resolution and great vertical accuracy but acquisition operations can be very costly for spatial scales larger than a couple of hundred square km and also have severe limitations in wetland areas and under cloudy and rainy conditions. The ideal situation would thus be to have a DEM technology that allows larger spatial coverage than LiDAR but without compromising resolution and vertical accuracy and still performing under some adverse weather conditions and at a reasonable cost. In this paper, we present a novel single pass In-SAR technology for airborne vehicles that is cost-effective and can generate DEMs with a vertical error of around 0.3 m for an average spatial resolution of 3 m. To demonstrate this capability, we compare a sample single-pass In-SAR Ka-band DEM of the California Central Valley from the NASA/JPL airborne GLISTIN-A to a high-resolution LiDAR DEM. We also perform a simple sensitivity analysis to floodplain inundation. Based on the findings of our analysis, we argue that this type of technology can and should be used to replace large regions of globally available lower resolution DEMs, particularly in coastal, delta and floodplain areas where a high number of assets, habitats and lives are at risk from natural disasters. We conclude with a discussion on requirements, advantages and caveats in terms of instrument and data processing.

  20. SNP-based non-invasive prenatal testing detects sex chromosome aneuploidies with high accuracy

    Science.gov (United States)

    Samango-Sprouse, Carole; Banjevic, Milena; Ryan, Allison; Sigurjonsson, Styrmir; Zimmermann, Bernhard; Hill, Matthew; Hall, Megan P.; Westemeyer, Margaret; Saucier, Jennifer; Demko, Zachary; Rabinowitz, Matthew

    2013-01-01

    Objective To develop a single nucleotide polymorphism- and informatics-based non-invasive prenatal test that detects sex chromosome aneuploidies early in pregnancy. Methods Fifteen aneuploid samples, including thirteen 45,X, two 47,XXY, and one 47,XYY, along with 185 euploid controls, were analyzed. Cell-free DNA was isolated from maternal plasma, amplified in a single multiplex PCR assay that targeted 19,488 polymorphic loci covering chromosomes 13, 18, 21, X, and Y, and sequenced. Sequencing results were analyzed using a Bayesian-based maximum likelihood statistical method to determine copy number of interrogated chromosomes, calculating sample-specific accuracies. Results Of the samples that passed a stringent quality control metric (93%), the algorithm correctly identified copy number at all five chromosomes in all 187 samples, for 934/935 correct calls as early as 9.4 weeks of gestation. We detected 45,X with 91.7% sensitivity (CI: 61.5-99.8%) and 100% specificity (CI: 97.9-100%), and 47,XXY and 47,XYY. The average calculated accuracy was 99.78%. Conclusion This method non-invasively detected 45,X, 47,XXY, and 47,XYY fetuses from cfDNA isolated from maternal plasma with high calculated accuracies, and thus offers a non-invasive method with the potential to function as a routine screen allowing for early prenatal detection of rarely diagnosed yet commonly occurring sex aneuploidies. PMID:23712453

  1. High-accuracy defect sizing for nozzle attachment welds using asymmetric TOFD

    Energy Technology Data Exchange (ETDEWEB)

    Bloodworth, T. [AEA Technology, Risley (United Kingdom)

    1999-09-01

    Inspection procedures for the detection, characterisation and high-accuracy sizing of defects in nozzle attachment welds in a Swedish BWR have been developed. These welds are set-on nozzle-to-pipe attachment welds between the main recirculation pipe and related piping systems. The nozzles and the main recirculation pipe are made of ferritic steel with austenitic stainless steel cladding on the inner surface. The overall wall thickness of the nozzle is 30 mm. The inspection uses an automated pulse-echo technique for the detection and length sizing of defects. Software for the display of complex geometry ultrasonic data is used to assist in data analysis. An unorthodox automated ultrasonic TOFD technique is used to measure the through-wall height of defects. This technique deploys probes on both the nozzle and main pipe surfaces. The TOFD data for this complex geometry are analysed using the CGTOFD software, to locate the origin of defect edge signals. The Qualification detection criterion for this inspection is the detection of defects 6 mm x 18 mm (height x length) or greater. The required length measurement accuracy is {+-}14 mm and the required through-wall height measurement accuracy is {+-}2.3 mm. This last requirement is very demanding. The inspection procedures for detection and sizing passed Procedure Qualification when measured against the above criteria on an `open` test specimen. Data collection and analysis personnel have subsequently passed Personnel Qualification using `blind` specimens. (Author)

  2. Uncertainty and target accuracy studies for the very high temperature reactor(VHTR) physics parameters.

    Energy Technology Data Exchange (ETDEWEB)

    Taiwo, T. A.; Palmiotti, G.; Aliberti, G.; Salvatores, M.; Kim, T.K.

    2005-09-16

    The potential impact of nuclear data uncertainties on a number of performance parameters (core and fuel cycle) of the prismatic block-type Very High Temperature Reactor (VHTR) has been evaluated and results are presented in this report. An uncertainty analysis has been performed, based on sensitivity theory, which underlines what cross-sections, what energy range and what isotopes are responsible for the most significant uncertainties. In order to give guidelines on priorities for new evaluations or validation experiments, required accuracies on specific nuclear data have been derived, accounting for target accuracies on major design parameters. Results of an extensive analysis indicate only a limited number of relevant parameters do not meet the target accuracies assumed in this work; this does not imply that the existing nuclear cross-section data cannot be used for the feasibility and pre-conceptual assessments of the VHTR. However, the results obtained depend on the uncertainty data used, and it is suggested to focus some future evaluation work on the production of consistent, as far as possible complete and user oriented covariance data.

  3. High accuracy measurements of magnetic field integrals for the european XFEL undulator systems

    Science.gov (United States)

    Wolff-Fabris, Frederik; Viehweger, Marc; Li, Yuhui; Pflüger, Joachim

    2016-10-01

    Two high accuracy moving wire (MW) measurement systems based on stretched wire technique were built for the European XFEL (XFEL.EU). They were dedicated to monitor, tune and improve the magnetic field integrals properties during the serial production of the undulator segments, phase shifters and air coil correctors for XFEL.EU. For the magnetic tuning of phase shifters and the calibration of the air coils correctors a short portable MW measurement bench was built to measure first field integrals in short devices with magnetic length of less than about 300 mm and with an ultimate accuracy much better than 1 G cm (0.001 T mm). A long MW measurement setup was dedicated to obtain the total first and second field integrals on the 5-meters long undulator segments with accuracy of about 4 G cm (0.004 T mm) and 2000 G cm2 (20 T mm2) for the 1st and 2nd field integrals, respectively. Using these data a method was developed to compute the proper corrections for the air coils correctors used at both extremities so that zero first and second field integrals for an undulator segment are obtained. It is demonstrated that charging air coils correctors with these corrections results in near zero effect to the electron trajectory in the undulator systems and consequently no negative impact on the self-amplified spontaneous emission (SASE) process should occur.

  4. Accuracy assessment of high frequency 3D ultrasound for digital impression-taking of prepared teeth

    Science.gov (United States)

    Heger, Stefan; Vollborn, Thorsten; Tinschert, Joachim; Wolfart, Stefan; Radermacher, Klaus

    2013-03-01

    Silicone based impression-taking of prepared teeth followed by plaster casting is well-established but potentially less reliable, error-prone and inefficient, particularly in combination with emerging techniques like computer aided design and manufacturing (CAD/CAM) of dental prosthesis. Intra-oral optical scanners for digital impression-taking have been introduced but until now some drawbacks still exist. Because optical waves can hardly penetrate liquids or soft-tissues, sub-gingival preparations still need to be uncovered invasively prior to scanning. High frequency ultrasound (HFUS) based micro-scanning has been recently investigated as an alternative to optical intra-oral scanning. Ultrasound is less sensitive against oral fluids and in principal able to penetrate gingiva without invasively exposing of sub-gingival preparations. Nevertheless, spatial resolution as well as digitization accuracy of an ultrasound based micro-scanning system remains a critical parameter because the ultrasound wavelength in water-like media such as gingiva is typically smaller than that of optical waves. In this contribution, the in-vitro accuracy of ultrasound based micro-scanning for tooth geometry reconstruction is being investigated and compared to its extra-oral optical counterpart. In order to increase the spatial resolution of the system, 2nd harmonic frequencies from a mechanically driven focused single element transducer were separated and corresponding 3D surface models were calculated for both fundamentals and 2nd harmonics. Measurements on phantoms, model teeth and human teeth were carried out for evaluation of spatial resolution and surface detection accuracy. Comparison of optical and ultrasound digital impression taking indicate that, in terms of accuracy, ultrasound based tooth digitization can be an alternative for optical impression-taking.

  5. A Quick Reference on High Anion Gap Metabolic Acidosis.

    Science.gov (United States)

    Funes, Silvia; de Morais, Helio Autran

    2017-03-01

    High anion gap (AG) metabolic acidoses can be identified by a decrease in pH, decrease in HCO3(-) or base excess, and an increased AG. The AG represents the difference between unmeasured cations and unmeasured anions; it increases secondary to the accumulation of anions other than bicarbonate and chloride. The most common causes of high AG acidosis are renal failure, diabetic ketoacidosis, and lactic acidosis. Severe increases in concentration of phosphorus can cause hyperphosphatemic acidosis. Copyright © 2016 Elsevier Inc. All rights reserved.

  6. A High-Performance Operational Amplifier for High-Speed High-Accuracy Switch-Capacitor Cells

    Institute of Scientific and Technical Information of China (English)

    Qi Fan; Ning Ning; Qi Yu; Da Chen

    2007-01-01

    A highspeed highaccuracy fully differenttial operational amplifier (opamp) is realized based on noMillercapacitor feedforward (NMCF) compensation scheme. In order to achieve a good phase margin, the NMCF compensation scheme uses the positive phase shift of lefthalfplane (LHP) zero caused by the feedforward path to counteract the negative phase shift of the nondominant pole. Compared to traditional Miller compensation method, the opamp obtains high gain and wide band synchronously without the polesplitting effect while saves significant chip area due to the absence of the Miller capacitor. Simulated by the 0.35 μm CMOS RF technology, the result shows that the openloop gain of the opamp is 118 dB with the unity gainbandwidth (UGBW)of 1 GHz, and the phase margin is 61°while the settling time is 5.8 ns when achieving 0.01% accuracy. The opamp is especially suitable for the frontend sample/hold (S/H)cell and the multiplying D/A converter(MDAC) module of the highspeed highresolution pipelined A/D converters(ADCs).

  7. Ultra-high accuracy optical testing: creating diffraction-limitedshort-wavelength optical systems

    Energy Technology Data Exchange (ETDEWEB)

    Goldberg, Kenneth A.; Naulleau, Patrick P.; Rekawa, Senajith B.; Denham, Paul E.; Liddle, J. Alexander; Gullikson, Eric M.; Jackson, KeithH.; Anderson, Erik H.; Taylor, John S.; Sommargren, Gary E.; Chapman,Henry N.; Phillion, Donald W.; Johnson, Michael; Barty, Anton; Soufli,Regina; Spiller, Eberhard A.; Walton, Christopher C.; Bajt, Sasa

    2005-08-03

    Since 1993, research in the fabrication of extreme ultraviolet (EUV) optical imaging systems, conducted at Lawrence Berkeley National Laboratory (LBNL) and Lawrence Livermore National Laboratory (LLNL), has produced the highest resolution optical systems ever made. We have pioneered the development of ultra-high-accuracy optical testing and alignment methods, working at extreme ultraviolet wavelengths, and pushing wavefront-measuring interferometry into the 2-20-nm wavelength range (60-600 eV). These coherent measurement techniques, including lateral shearing interferometry and phase-shifting point-diffraction interferometry (PS/PDI) have achieved RMS wavefront measurement accuracies of 0.5-1-{angstrom} and better for primary aberration terms, enabling the creation of diffraction-limited EUV optics. The measurement accuracy is established using careful null-testing procedures, and has been verified repeatedly through high-resolution imaging. We believe these methods are broadly applicable to the advancement of short-wavelength optical systems including space telescopes, microscope objectives, projection lenses, synchrotron beamline optics, diffractive and holographic optics, and more. Measurements have been performed on a tunable undulator beamline at LBNL's Advanced Light Source (ALS), optimized for high coherent flux; although many of these techniques should be adaptable to alternative ultraviolet, EUV, and soft x-ray light sources. To date, we have measured nine prototype all-reflective EUV optical systems with NA values between 0.08 and 0.30 (f/6.25 to f/1.67). These projection-imaging lenses were created for the semiconductor industry's advanced research in EUV photolithography, a technology slated for introduction in 2009-13. This paper reviews the methods used and our program's accomplishments to date.

  8. High Accuracy, Two-Dimensional Read-Out in Multiwire Proportional Chambers

    Science.gov (United States)

    Charpak, G.; Sauli, F.

    1973-02-14

    In most applications of proportional chambers, especially in high-energy physics, separate chambers are used for measuring different coordinates. In general one coordinate is obtained by recording the pulses from the anode wires around which avalanches have grown. Several methods have been imagined for obtaining the position of an avalanche along a wire. In this article a method is proposed which leads to the same range of accuracies and may be preferred in some cases. The problem of accurate measurements for large-size chamber is also discussed.

  9. High-accuracy thickness measurement of a transparent plate with the heterodyne central fringe identification technique

    Energy Technology Data Exchange (ETDEWEB)

    Wu, Wang-Tsung; Hsieh, Hung-Chih; Chang, Wei-Yao; Chen, Yen-Liang; Su, Der-Chin

    2011-07-20

    In a modified Twyman-Green interferometer, the optical path variation is measured with the heterodyne central fringe identification technique, as the light beam is focused by a displaced microscopic objective on the front/rear surface of the test transparent plate. The optical path length variation is then measured similarly after the test plate is removed. The geometrical thickness of the test plate can be calculated under the consideration of dispersion effect. This method has a wide measurable range and a high accuracy in the measurable range.

  10. A small and high accuracy gyro stabilization electro-optical platform

    Science.gov (United States)

    Qiu, Haitao; Han, Yonggen; Lv, Yanhong

    2008-10-01

    A high accuracy line-of-sight (LOS) Stabilization system based on digital control technology was designed. The current feedback closed-loop system was introduced which uses the CCD graphic and resolver to constitute the position closed-loop and uses the optic fiber gyro to constitute the rate closed-loop. In order to realize zero steady-state error of angular output in counteracting disturbance from carrier, a PII2 (proportional-integral-double integral) control scheme is proposed. The hardware configuration and software system is presented. Experimental results show that the system has perfect dynamic and static performance and the technical requirements were satisfied.

  11. High Accuracy Three-dimensional Simulation of Micro Injection Moulded Parts

    DEFF Research Database (Denmark)

    Tosello, Guido; Costa, F. S.; Hansen, Hans Nørgaard

    2011-01-01

    Micro injection moulding (μIM) is the key replication technology for high precision manufacturing of polymer micro products. Data analysis and simulations on micro-moulding experiments have been conducted during the present validation study. Detailed information about the μIM process was gathered...... and used to establish a reliable simulation methodology suitable for μIM parts. Various Simulation set-up parameters that have been considered in order to improve the simulation accuracy: injection speed profile, melt and mould temperatures, 3D mesh, material rheology, inertia effect and shrinkage...

  12. High-accuracy mass determination of unstable nuclei with a Penning trap mass spectrometer

    CERN Multimedia

    2002-01-01

    The mass of a nucleus is its most fundamental property. A systematic study of nuclear masses as a function of neutron and proton number allows the observation of collective and single-particle effects in nuclear structure. Accurate mass data are the most basic test of nuclear models and are essential for their improvement. This is especially important for the astrophysical study of nuclear synthesis. In order to achieve the required high accuracy, the mass of ions captured in a Penning trap is determined via their cyclotron frequency $ \

  13. An angle encoder for super-high resolution and super-high accuracy using SelfA

    Science.gov (United States)

    Watanabe, Tsukasa; Kon, Masahito; Nabeshima, Nobuo; Taniguchi, Kayoko

    2014-06-01

    Angular measurement technology at high resolution for applications such as in hard disk drive manufacturing machines, precision measurement equipment and aspherical process machines requires a rotary encoder with high accuracy, high resolution and high response speed. However, a rotary encoder has angular deviation factors during operation due to scale error or installation error. It has been assumed to be impossible to achieve accuracy below 0.1″ in angular measurement or control after the installation onto the rotating axis. Self-calibration (Lu and Trumper 2007 CIRP Ann. 56 499; Kim et al 2011 Proc. MacroScale; Probst 2008 Meas. Sci. Technol. 19 015101; Probst et al Meas. Sci. Technol. 9 1059; Tadashi and Makoto 1993 J. Robot. Mechatronics 5 448; Ralf et al 2006 Meas. Sci. Technol. 17 2811) and cross-calibration (Probst et al 1998 Meas. Sci. Technol. 9 1059; Just et al 2009 Precis. Eng. 33 530; Burnashev 2013 Quantum Electron. 43 130) technologies for a rotary encoder have been actively discussed on the basis of the principle of circular closure. This discussion prompted the development of rotary tables which achieve reliable and high accuracy angular verification. We apply these technologies for the development of a rotary encoder not only to meet the requirement of super-high accuracy but also to meet that of super-high resolution. This paper presents the development of an encoder with 221 = 2097 152 resolutions per rotation (360°), that is, corresponding to a 0.62″ signal period, achieved by the combination of a laser rotary encoder supplied by Magnescale Co., Ltd and a self-calibratable encoder (SelfA) supplied by The National Institute of Advanced Industrial Science & Technology (AIST). In addition, this paper introduces the development of a rotary encoder to guarantee ±0.03″ accuracy at any point of the interpolated signal, with respect to the encoder at the minimum resolution of 233, that is, corresponding to a 0.0015″ signal period after

  14. High-accuracy current sensing circuit with current compensation technique for buck-boost converter

    Science.gov (United States)

    Rao, Yuan; Deng, Wan-Ling; Huang, Jun-Kai

    2015-03-01

    A novel on-chip current sensing circuit with current compensation technique suitable for buck-boost converter is presented in this article. The proposed technique can sense the full-range inductor current with high accuracy and high speed. It is mainly based on matched current mirror and does not require a large proportion of aspect ratio between the powerFET and the senseFET, thus it reduces the complexity of circuit design and the layout mismatch issue without decreasing the power efficiency. The circuit is fabricated with TSMC 0.25 µm 2P5M mixed-signal process. Simulation results show that the buck-boost converter can be operated at 200 kHz to 4 MHz switching frequency with an input voltage from 2.8 to 4.7 V. The output voltage is 3.6 V, and the maximum accuracy for both high and low side sensing current reaches 99% within the load current ranging from 200 to 600 mA.

  15. Simple high-accuracy resolution program for convective modelling of discontinuities

    Science.gov (United States)

    Leonard, B. P.

    1988-01-01

    For steady multidimensional convection, the Quadratic Upstream Interpolation for Convective Kinematics (QUICK) scheme has several attractive properties. However, for highly convective simulation of step profiles, QUICK produces unphysical overshoots and a few oscillations, and this may cause serious problems in nonlinear flows. Fortunately, it is possible to modify the convective flux by writing the normalized convected control-volume face value as a function of the normalized adjacent upstream node value, developing criteria for monotonic resolution without sacrificing formal accuracy. This results in a nonlinear functional relationship between the normalized variables, whereas standard methods are all linear in this sense. The resulting Simple High Accuracy Resolution Program (SHARP) can be applied to steady multidimensional flows containing thin shear or mixing layers, shock waves, and other frontal phenomena. This represents a significant advance in modeling highly convective flows of engineering and geophysical importance. SHARP is based on an explicit, conservative, control-volume flux formation, equally applicable to one, two, or three dimensional elliptic, parabolic, hyperbolic, or mixed-flow regimes. Results are given for the bench-mark purely convective first-order results and the nonmonotonic predictions of second- and third-order upwinding.

  16. High-accuracy optimal finite-thrust trajectories for Moon escape

    Science.gov (United States)

    Shen, Hong-Xin; Casalino, Lorenzo

    2017-02-01

    The optimization problem of fuel-optimal trajectories from a low circular Moon orbit to a target hyperbolic excess velocity vector using finite-thrust propulsion is solved. The ability to obtain the most accurate satisfaction of necessary optimality conditions in a high-accuracy dynamic model is the main motivation of the current study. The solutions allow attaining anytime-return Earth-interface conditions from a low lunar orbit. Gravitational effects of the Sun, Earth, and Moon are included throughout the entire trajectory. Severe constraints on the fuel budget combined with high-accuracy demands on the endpoint conditions necessitate a high-fidelity solution to the trajectory optimization problem and JPL DE405 ephemeris model is used to determine the perturbing bodies' positions. The optimization problem is solved using an indirect method. The optimality of the solution is verified by an application of Pontryagin's maximum principle. More accurate and fuel-efficient trajectories are found for the same mission objectives and constraints published in other research, emphasizing the advantages of this technique. It is also shown that the thrust structure consists of three finite burns. In contrast to previous research, no singular arc is required in the optimal solutions, and all the controls appear bang-bang.

  17. Emergency positioning system accuracy with infrared LEDs in high-security facilities

    Science.gov (United States)

    Knoch, Sierra N.; Nelson, Charles; Walker, Owens

    2017-05-01

    Instantaneous personnel location presents a challenge in Department of Defense applications where high levels of security restrict real-time tracking of crew members. During emergency situations, command and control requires immediate accountability of all personnel. Current radio frequency (RF) based indoor positioning systems can be unsuitable due to RF leakage and electromagnetic interference with sensitively calibrated machinery on variable platforms like ships, submarines and high-security facilities. Infrared light provide a possible solution to this problem. This paper proposes and evaluates an indoor line-of-sight positioning system that is comprised of IR and high-sensitivity CMOS camera receivers. In this system the movement of the LEDs is captured by the camera, uploaded and analyzed; the highest point of power is located and plotted to create a blueprint of crewmember location. Results provided evaluate accuracy as a function of both wavelength and environmental conditions. Research will further evaluate the accuracy of the LED transmitter and CMOS camera receiver system. Transmissions in both the 780 and 850nm IR are analyzed.

  18. High-Accuracy Methods for Numerical Flow Analysis Using Adaptive Non-Linear Wavelets

    Science.gov (United States)

    2012-08-01

    to the research by Bacry, Mallat and Papanicolaou [10] or Holmström and Walden [11], AWGM solves PDE problems in a wavelet coefficient space. It is...of the threshold value, these variations are discarded and restricted by multiplying the weighting factor . This process can especially contribute the...weighting factor . This restriction technique enhances the convergence rate of steady state calculations. References [1] Harten A., “High

  19. High accuracy genotyping directly from genomic DNA using a rolling circle amplification based assay

    Directory of Open Access Journals (Sweden)

    Du Yuefen

    2003-05-01

    Full Text Available Abstract Background Rolling circle amplification of ligated probes is a simple and sensitive means for genotyping directly from genomic DNA. SNPs and mutations are interrogated with open circle probes (OCP that can be circularized by DNA ligase when the probe matches the genotype. An amplified detection signal is generated by exponential rolling circle amplification (ERCA of the circularized probe. The low cost and scalability of ligation/ERCA genotyping makes it ideally suited for automated, high throughput methods. Results A retrospective study using human genomic DNA samples of known genotype was performed for four different clinically relevant mutations: Factor V Leiden, Factor II prothrombin, and two hemochromatosis mutations, C282Y and H63D. Greater than 99% accuracy was obtained genotyping genomic DNA samples from hundreds of different individuals. The combined process of ligation/ERCA was performed in a single tube and produced fluorescent signal directly from genomic DNA in less than an hour. In each assay, the probes for both normal and mutant alleles were combined in a single reaction. Multiple ERCA primers combined with a quenched-peptide nucleic acid (Q-PNA fluorescent detection system greatly accellerated the appearance of signal. Probes designed with hairpin structures reduced misamplification. Genotyping accuracy was identical from either purified genomic DNA or genomic DNA generated using whole genome amplification (WGA. Fluorescent signal output was measured in real time and as an end point. Conclusions Combining the optimal elements for ligation/ERCA genotyping has resulted in a highly accurate single tube assay for genotyping directly from genomic DNA samples. Accuracy exceeded 99 % for four probe sets targeting clinically relevant mutations. No genotypes were called incorrectly using either genomic DNA or whole genome amplified sample.

  20. Discovery and validation of urine markers of acute pediatric appendicitis using high accuracy mass spectrometry

    Science.gov (United States)

    Kentsis, Alex; Lin, Yin Yin; Kurek, Kyle; Calicchio, Monica; Wang, Yan Yan; Monigatti, Flavio; Campagne, Fabien; Lee, Richard; Horwitz, Bruce; Steen, Hanno; Bachur, Richard

    2015-01-01

    Study Objective Molecular definition of disease has been changing all aspects of medical practice, from diagnosis and screening to understanding and treatment. Acute appendicitis is among many human conditions that are complicated by the heterogeneity of clinical presentation and shortage of diagnostic markers. Here, we sought to profile the urine of patients with appendicitis with the goal of identifying new diagnostic markers. Methods Candidate markers were identified from the urine of children with histologically proven appendicitis by using high accuracy mass spectrometry proteome profiling. These systemic and local markers were used to assess the probability of appendicitis in a blinded, prospective study of children being evaluated for acute abdominal pain in our emergency department. Tests of performance of the markers were evaluated against the pathologic diagnosis and histologic grade of appendicitis. Results Test performance of 57 identified candidate markers was studied in 67 patients, with median age of 11 years, 37% of whom had appendicitis. Several exhibited favorable diagnostic performance, including calgranulin A (S100-A8), α-1-acid glycoprotein 1 (orosomucoid), and leucine-rich α-2-glycoprotein (LRG), with the ROC AUC and values of 0.84 (95 % CI 0.72-0.95), 0.84 (0.72-0.95), and 0.97 (0.93-1.0), respectively. LRG was enriched in diseased appendices and its abundance correlated with severity of appendicitis. Conclusions High accuracy mass spectrometry urine proteome profiling allowed identification of diagnostic markers of acute appendicitis. Usage of LRG and other identified biomarkers may improve the diagnostic accuracy of clinical evaluations of appendicitis. PMID:19556024

  1. Perturbational treatment of spin-orbit coupling for generally applicable high-level multi-reference methods

    CERN Document Server

    Mai, Sebastian; Plasser, Felix; Marquetand, Philipp; Lischka, Hans; González, Leticia

    2016-01-01

    An efficient perturbational treatment of spin-orbit coupling within the framework of high-level multi-reference techniques has been implemented in the most recent version of the COLUMBUS quantum chemistry package, extending the existing fully variational two-component (2c) multi-reference configuration interaction singles and doubles (MRCISD) method. The proposed scheme follows related implementations of quasi-degenerate perturbation theory (QDPT) model space techniques. Our model space is built either from uncontracted, large-scale scalar relativistic MRCISD wavefunctions or based on the scalar-relativistic solutions of the linear-response-theory-based multi-configurational averaged quadratic coupled cluster method (LRT-MRAQCC). The latter approach allows for a consistent, approximatively size-consistent and size-extensive treatment of spin-orbit coupling. The approach is described in detail and compared to a number of related techniques. The inherent accuracy of the QDPT approach is validated by comparing c...

  2. Development of C-reactive protein certified reference material NMIJ CRM 6201-b: optimization of a hydrolysis process to improve the accuracy of amino acid analysis.

    Science.gov (United States)

    Kato, Megumi; Kinumi, Tomoya; Yoshioka, Mariko; Goto, Mari; Fujii, Shin-Ichiro; Takatsu, Akiko

    2015-04-01

    To standardize C-reactive protein (CRP) assays, the National Metrology Institute of Japan (NMIJ) has developed a C-reactive protein solution certified reference material, CRM 6201-b, which is intended for use as a primary reference material to enable the SI-traceable measurement of CRP. This study describes the development process of CRM 6201-b. As a candidate material of the CRM, recombinant human CRP solution was selected because of its higher purity and homogeneity than the purified material from human serum. Gel filtration chromatography was used to examine the homogeneity and stability of the present CRM. The total protein concentration of CRP in the present CRM was determined by amino acid analysis coupled to isotope-dilution mass spectrometry (IDMS-AAA). To improve the accuracy of IDMS-AAA, we optimized the hydrolysis process by examining the effect of parameters such as the volume of protein samples taken for hydrolysis, the procedure of sample preparation prior to the hydrolysis, hydrolysis temperature, and hydrolysis time. Under optimized conditions, we conducted two independent approaches in which the following independent hydrolysis and liquid chromatography-isotope dilution mass spectrometry (LC-IDMS) were combined: one was vapor-phase acid hydrolysis (130 °C, 24 h) and hydrophilic interaction liquid chromatography-mass spectrometry (HILIC-MS) method, and the other was microwave-assisted liquid-phase acid hydrolysis (150 °C, 3 h) and pre-column derivatization liquid chromatography-tandem mass spectrometry (LC-MS/MS) method. The quantitative values of the two different amino acid analyses were in agreement within their uncertainties. The certified value was the weighted mean of the results of the two methods. Uncertainties from the value-assignment method, between-method variance, homogeneity, long-term stability, and short-term stability were taken into account in evaluating the uncertainty for a certified value. The certified value and the

  3. High accuracy of family history of melanoma in Danish melanoma cases

    DEFF Research Database (Denmark)

    Wadt, Karin A W; Drzewiecki, Krzysztof T; Gerdes, Anne-Marie

    2015-01-01

    The incidence of melanoma in Denmark has immensely increased over the last 10 years making Denmark a high risk country for melanoma. In the last two decades multiple public campaigns have sought to increase the awareness of melanoma. Family history of melanoma is a known major risk factor...... but previous studies have shown that self-reported family history of melanoma is highly inaccurate. These studies are 15 years old and we wanted to examine if a higher awareness of melanoma has increased the accuracy of self-reported family history of melanoma. We examined the family history of 181 melanoma...... probands who reported 199 cases of melanoma in relatives, of which 135 cases where in first degree relatives. We confirmed the diagnosis of melanoma in 77% of all relatives, and in 83% of first degree relatives. In 181 probands we validated the negative family history of melanoma in 748 first degree...

  4. High Accuracy mass Measurement of the very Short-Lived Halo Nuclide $^{11}$Li

    CERN Multimedia

    Le scornet, G

    2002-01-01

    The archetypal halo nuclide $^{11}$Li has now attracted a wealth of experimental and theoretical attention. The most outstanding property of this nuclide, its extended radius that makes it as big as $^{48}$Ca, is highly dependent on the binding energy of the two neutrons forming the halo. New generation experiments using radioactive beams with elastic proton scattering, knock-out and transfer reactions, together with $\\textit{ab initio}$ calculations require the tightening of the constraint on the binding energy. Good metrology also requires confirmation of the sole existing precision result to guard against a possible systematic deviation (or mistake). We propose a high accuracy mass determintation of $^{11}$Li, a particularly challenging task due to its very short half-life of 8.6 ms, but one perfectly suiting the MISTRAL spectrometer, now commissioned at ISOLDE. We request 15 shifts of beam time.

  5. Arithmetic Accuracy in Children From High- and Low-Income Schools

    Directory of Open Access Journals (Sweden)

    Elida V. Laski

    2016-04-01

    Full Text Available This study investigated income group differences in kindergartners’ and first graders’ (N = 161 arithmetic by examining the link between accuracy and strategy use on simple and complex addition problems. Low-income children were substantially less accurate than high-income children, in terms of both percentage of correctly solved problems and the magnitude of errors, with low-income first graders being less accurate than high-income kindergartners. Higher-income children were more likely to use sophisticated mental strategies than their lower-income peers, who used predominantly inefficient counting or inappropriate strategies. Importantly, this difference in strategies mediated the relation between income group and addition. Examining underlying strategies has implications for understanding income group differences in arithmetic and potential means of remedying it via instruction.

  6. High Accuracy Liquid Propellant Slosh Predictions Using an Integrated CFD and Controls Analysis Interface

    Science.gov (United States)

    Marsell, Brandon; Griffin, David; Schallhorn, Dr. Paul; Roth, Jacob

    2012-01-01

    Coupling computational fluid dynamics (CFD) with a controls analysis tool elegantly allows for high accuracy predictions of the interaction between sloshing liquid propellants and th e control system of a launch vehicle. Instead of relying on mechanical analogs which are not valid during aU stages of flight, this method allows for a direct link between the vehicle dynamic environments calculated by the solver in the controls analysis tool to the fluid flow equations solved by the CFD code. This paper describes such a coupling methodology, presents the results of a series of test cases, and compares said results against equivalent results from extensively validated tools. The coupling methodology, described herein, has proven to be highly accurate in a variety of different cases.

  7. Integrated CFD and Controls Analysis Interface for High Accuracy Liquid Propellant Slosh Predictions

    Science.gov (United States)

    Marsell, Brandon; Griffin, David; Schallhorn, Paul; Roth, Jacob

    2012-01-01

    Coupling computational fluid dynamics (CFD) with a controls analysis tool elegantly allows for high accuracy predictions of the interaction between sloshing liquid propellants and the control system of a launch vehicle. Instead of relying on mechanical analogs which are n0t va lid during all stages of flight, this method allows for a direct link between the vehicle dynamic environments calculated by the solver in the controls analysis tool to the fluid now equations solved by the CFD code. This paper describes such a coupling methodology, presents the results of a series of test cases, and compares said results against equivalent results from extensively validated tools. The coupling methodology, described herein, has proven to be highly accurate in a variety of different cases.

  8. Using Mobile Laser Scanning Data for Features Extraction of High Accuracy Driving Maps

    Science.gov (United States)

    Yang, Bisheng; Liu, Yuan; Liang, Fuxun; Dong, Zhen

    2016-06-01

    High Accuracy Driving Maps (HADMs) are the core component of Intelligent Drive Assistant Systems (IDAS), which can effectively reduce the traffic accidents due to human error and provide more comfortable driving experiences. Vehicle-based mobile laser scanning (MLS) systems provide an efficient solution to rapidly capture three-dimensional (3D) point clouds of road environments with high flexibility and precision. This paper proposes a novel method to extract road features (e.g., road surfaces, road boundaries, road markings, buildings, guardrails, street lamps, traffic signs, roadside-trees, power lines, vehicles and so on) for HADMs in highway environment. Quantitative evaluations show that the proposed algorithm attains an average precision and recall in terms of 90.6% and 91.2% in extracting road features. Results demonstrate the efficiencies and feasibilities of the proposed method for extraction of road features for HADMs.

  9. Initial development of high-accuracy CFRP panel for DATE5 antenna

    Science.gov (United States)

    Qian, Yuan; Lou, Zheng; Hao, Xufeng; Zhu, Jing; Cheng, Jingquan; Wang, Hairen; Zuo, Yingxi; Yang, Ji

    2016-07-01

    DATE5 antenna, which is a 5m telescope for terahertz exploration, will be sited at Dome A, Antarctica. It is necessary to keep high surface accuracy of the primary reflector panels so that high observing efficiency can be achieved. In antenna field, carbon fiber reinforced composite (CFRP) sandwich panels are widely used as these panels are light in weight, high in strength, low in thermal expansion, and cheap in mass fabrication. In DATE5 project, CFRP panels are important panel candidates. In the design study phase, a CFRP prototype panel of 1-meter size is initially developed for the verification purpose. This paper introduces the material arrangement in the sandwich panel, measured performance of this testing sandwich structure samples, and together with the panel forming process. For anti-icing in the South Pole region, a special CFRP heating film is embedded in the front skin of sandwich panel. The properties of some types of basic building materials are tested. Base on the results, the deformation of prototype panel with different sandwich structures and skin layers are simulated and a best structural concept is selected. The panel mold used is a high accuracy one with a surface rms error of 1.4 μm. Prototype panels are replicated from the mold. Room temperature curing resin is used to reduce the thermal deformation in the resin transfer process. In the curing, vacuum negative pressure technology is also used to increase the volume content of carbon fiber. After the measurement of the three coordinate measure machine (CMM), a prototype CFRP panel of 5.1 μm rms surface error is developed initially.

  10. Usability and accuracy of high-resolution detectors for daily quality assurance for robotic radiosurgery

    Directory of Open Access Journals (Sweden)

    Loutfi-Krauss Britta

    2017-09-01

    Full Text Available For daily CyberKnife QA a Winston-Lutz-Test (Automated-Quality-Assurance, AQA is used to determine sub-millimeter deviations in beam delivery accuracy. This test is performed using gafchromic film, an extensive and user-dependent method requiring the use of disposables. We therefore analyzed the usability and accuracy of high-resolution detector arrays. We analyzed a liquid-filled ionization-chamber array (Octavius 1000SRS, PTW, Germany, which has a central resolution of 2.5mm. To test sufficient sensitivity, beam profiles with robot shifts of 0.1mm along the arrays' axes were measured. The detected deviation between the shifted and central profile were compared to the real robot's position. We then compared the results to the SRS-Profiler (SunNuclear, USA with 4.0mm resolution and to the Nonius (QUART, Germany, a single-line diode detector with 2.8mm resolution. Finally, AQA variance and usability were analyzed performing a number of AQA tests over time, which required the use of specially designed fixtures for each array, and the results were compared to film. Concerning sensitivity, the 1000SRS detected the beam profile shifts with a maximum difference of 0.11mm (mean deviation = 0.03mm compared to the actual robot shift. The Nonius and SRS-Profiler showed differences of up to 0.15mm and 0.69mm with mean deviation of 0.05mm and 0.18mm, respectively. Analyzing the variation of AQA results over time, the 1000SRS showed a comparable standard deviation to film (0.26mm vs. 0.18mm. The SRS-Profiler and the Nonius showed a standard deviation of 0.16mm and 0.24mm, respectively. The 1000SRS seems to provide equivalent accuracy and sensitivity to the gold standard film when performing daily AQA tests. Compared to other detectors in our study the sensitivity as well as the accuracy of the 1000SRS appears to be superior and more user-friendly. Furthermore, no significant modification of the standard AQA procedure is required when introducing 1000SRS for

  11. PACMAN Project: A New Solution for the High-accuracy Alignment of Accelerator Components

    CERN Document Server

    Mainaud Durand, Helene; Buzio, Marco; Caiazza, Domenico; Catalán Lasheras, Nuria; Cherif, Ahmed; Doytchinov, Iordan; Fuchs, Jean-Frederic; Gaddi, Andrea; Galindo Munoz, Natalia; Gayde, Jean-Christophe; Kamugasa, Solomon; Modena, Michele; Novotny, Peter; Russenschuck, Stephan; Sanz, Claude; Severino, Giordana; Tshilumba, David; Vlachakis, Vasileios; Wendt, Manfred; Zorzetti, Silvia

    2016-01-01

    The beam alignment requirements for the next generation of lepton colliders have become increasingly challenging. As an example, the alignment requirements for the three major collider components of the CLIC linear collider are as follows. Before the first beam circulates, the Beam Position Monitors (BPM), Accelerating Structures (AS)and quadrupoles will have to be aligned up to 10 μm w.r.t. a straight line over 200 m long segments, along the 20 km of linacs. PACMAN is a study on Particle Accelerator Components' Metrology and Alignment to the Nanometre scale. It is an Innovative Doctoral Program, funded by the EU and hosted by CERN, providing high quality training to 10 Early Stage Researchers working towards a PhD thesis. The technical aim of the project is to improve the alignment accuracy of the CLIC components by developing new methods and tools addressing several steps of alignment simultaneously, to gain time and accuracy. The tools and methods developed will be validated on a test bench. This paper pr...

  12. An output amplitude configurable wideband automatic gain control with high gain step accuracy

    Institute of Scientific and Technical Information of China (English)

    何晓丰; 莫太山; 马成炎; 叶甜春

    2012-01-01

    An output amplitude configurable wideband automatic gain control (AGC) with high gain step accuracy for the GNSS receiver is presented.The amplitude of an AGC is configurable in order to cooperate with baseband chips to achieve interference suppression and be compatible with different full range ADCs.And what's more,the gain-boosting technology is introduced and the circuit is improved to increase the step accuracy.A zero,which is composed by the source feedback resistance and the source capacity,is introduced to compensate for the pole.The AGC is fabricated in a 0.18 μm CMOS process.The AGC shows a 62 dB gain control range by 1 dB each step with a gain error of less than 0.2 dB.The AGC provides 3 dB bandwidth larger than 80 MHz and the overall power consumption is less than 1.8 mA,and the die area is 800 × 300μm2.

  13. Real-Time and High-Accuracy Arctangent Computation Using CORDIC and Fast Magnitude Estimation

    Directory of Open Access Journals (Sweden)

    Luca Pilato

    2017-03-01

    Full Text Available This paper presents an improved VLSI (Very Large Scale of Integration architecture for real-time and high-accuracy computation of trigonometric functions with fixed-point arithmetic, particularly arctangent using CORDIC (Coordinate Rotation Digital Computer and fast magnitude estimation. The standard CORDIC implementation suffers of a loss of accuracy when the magnitude of the input vector becomes small. Using a fast magnitude estimator before running the standard algorithm, a pre-processing magnification is implemented, shifting the input coordinates by a proper factor. The entire architecture does not use a multiplier, it uses only shift and add primitives as the original CORDIC, and it does not change the data path precision of the CORDIC core. A bit-true case study is presented showing a reduction of the maximum phase error from 414 LSB (angle error of 0.6355 rad to 4 LSB (angle error of 0.0061 rad, with small overheads of complexity and speed. Implementation of the new architecture in 0.18 µm CMOS technology allows for real-time and low-power processing of CORDIC and arctangent, which are key functions in many embedded DSP systems. The proposed macrocell has been verified by integration in a system-on-chip, called SENSASIP (Sensor Application Specific Instruction-set Processor, for position sensor signal processing in automotive measurement applications.

  14. High Accuracy Mass Measurement of the Dripline Nuclides $^{12,14}$Be

    CERN Multimedia

    2002-01-01

    State-of-the art, three-body nuclear models that describe halo nuclides require the binding energy of the halo neutron(s) as a critical input parameter. In the case of $^{14}$Be, the uncertainty of this quantity is currently far too large (130 keV), inhibiting efforts at detailed theoretical description. A high accuracy, direct mass deterlnination of $^{14}$Be (as well as $^{12}$Be to obtain the two-neutron separation energy) is therefore required. The measurement can be performed with the MISTRAL spectrometer, which is presently the only possible solution due to required accuracy (10 keV) and short half-life (4.5 ms). Having achieved a 5 keV uncertainty for the mass of $^{11}$Li (8.6 ms), MISTRAL has proved the feasibility of such measurements. Since the current ISOLDE production rate of $^{14}$Be is only about 10/s, the installation of a beam cooler is underway in order to improve MISTRAL transmission. The projected improvement of an order of magnitude (in each transverse direction) will make this measureme...

  15. Combined Scintigraphy and Tumor Marker Analysis Predicts Unfavorable Histopathology of Neuroblastic Tumors with High Accuracy.

    Directory of Open Access Journals (Sweden)

    Wolfgang Peter Fendler

    Full Text Available Our aim was to improve the prediction of unfavorable histopathology (UH in neuroblastic tumors through combined imaging and biochemical parameters.123I-MIBG SPECT and MRI was performed before surgical resection or biopsy in 47 consecutive pediatric patients with neuroblastic tumor. Semi-quantitative tumor-to-liver count-rate ratio (TLCRR, MRI tumor size and margins, urine catecholamine and NSE blood levels of neuron specific enolase (NSE were recorded. Accuracy of single and combined variables for prediction of UH was tested by ROC analysis with Bonferroni correction.34 of 47 patients had UH based on the International Neuroblastoma Pathology Classification (INPC. TLCRR and serum NSE both predicted UH with moderate accuracy. Optimal cut-off for TLCRR was 2.0, resulting in 68% sensitivity and 100% specificity (AUC-ROC 0.86, p < 0.001. Optimal cut-off for NSE was 25.8 ng/ml, resulting in 74% sensitivity and 85% specificity (AUC-ROC 0.81, p = 0.001. Combination of TLCRR/NSE criteria reduced false negative findings from 11/9 to only five, with improved sensitivity and specificity of 85% (AUC-ROC 0.85, p < 0.001.Strong 123I-MIBG uptake and high serum level of NSE were each predictive of UH. Combined analysis of both parameters improved the prediction of UH in patients with neuroblastic tumor. MRI parameters and urine catecholamine levels did not predict UH.

  16. High-accuracy same-beam VLBI observations using Shanghai and Urumqi telescopes

    Institute of Scientific and Technical Information of China (English)

    KIKUCHI; Fuyuhiko; KAMATA; Shun’ichi; MATSUMOTO; Koji; HANADA; Hideo

    2009-01-01

    The same-beam VLBI observations of Rstar and Vstar,which were two small satellites of Japanese lunar mission,SELENE,were successfully performed by using Shanghai and Urumqi 25-m telescopes. When the separation angle between Rstar and Vstar was less than 0.1 deg,the differential phase delay of the X-band signals between Rstar and Vstar on Shanghai-Urumqi baseline was obtained with a very small error of 0.15 mm rms,which was reduced by 1-2 order compared with the former VLBI results. When the separation angle was less than 0.56 deg,the differential phase delay of the S-band signals was also obtained with a very small error of several mm rms. The orbit determination for Rstar and Vstar was performed,and the accuracy was improved to a level of several meters by using VLBI and Doppler data. The high-accuracy same-beam differential VLBI technique is very useful in orbit determination for a spacecraft,and will be used in orbit determination for Mars missions of China Yinghuo-1 and Russia Phobos-grunt.

  17. High-accuracy same-beam VLBI observations using Shanghai and Urumqi telescopes

    Institute of Scientific and Technical Information of China (English)

    LIU QingHui; PING JingSong; FAN QingYuan; XIA Bo; AN Tao; QIAN ZhiHan; YANG WenJun; ZHANG Hua; WANG Zhen; WANG Na; SHI Xian; KIKUCHI Fuyuhiko; HUANG Qian; KAMATA Shun'ichi; MATSUMOTO Koji; HANADA Hideo; HONG XiaoYu; YU AiLi

    2009-01-01

    The same-beam VLBI observations of Rstar and Vstar, which were two small satellites of Japanese lunar mission, SELENE, were successfully performed by using Shanghai and Urumqi 25-m telescopes.When the separation angle between Rstar and Vstar was less than 0.1 deg, the differential phase delay of the X-band signals between Rstar and Vstar on Shanghai-Urumqi baseline was obtained with a very small error of 0.15 mm rms, which was reduced by 1-2 order compared with the former VLBI results.When the separation angle was less than 0.56 deg, the differential phase delay of the S-band signals was also obtained with a very small error of several mm rms. The orbit determination for Rstar and Vstar was performed, and the accuracy was improved to a level of several meters by using VLBI and Doppler data. The high-accuracy same-beam differential VLBI technique is very useful in orbit determination for a spacecraft, and will be used in orbit determination for Mars missions of China Yinghuo-1 and Russia Phobos-grunt.

  18. Reducing Systematic Centroid Errors Induced by Fiber Optic Faceplates in Intensified High-Accuracy Star Trackers

    Science.gov (United States)

    Xiong, Kun; Jiang, Jie

    2015-01-01

    Compared with traditional star trackers, intensified high-accuracy star trackers equipped with an image intensifier exhibit overwhelmingly superior dynamic performance. However, the multiple-fiber-optic faceplate structure in the image intensifier complicates the optoelectronic detecting system of star trackers and may cause considerable systematic centroid errors and poor attitude accuracy. All the sources of systematic centroid errors related to fiber optic faceplates (FOFPs) throughout the detection process of the optoelectronic system were analyzed. Based on the general expression of the systematic centroid error deduced in the frequency domain and the FOFP modulation transfer function, an accurate expression that described the systematic centroid error of FOFPs was obtained. Furthermore, reduction of the systematic error between the optical lens and the input FOFP of the intensifier, the one among multiple FOFPs and the one between the output FOFP of the intensifier and the imaging chip of the detecting system were discussed. Two important parametric constraints were acquired from the analysis. The correctness of the analysis on the optoelectronic detecting system was demonstrated through simulation and experiment. PMID:26016920

  19. Research on the classification result and accuracy of building windows in high resolution satellite images: take the typical rural buildings in Guangxi, China, as an example

    Science.gov (United States)

    Li, Baishou; Gao, Yujiu

    2015-12-01

    The information extracted from the high spatial resolution remote sensing images has become one of the important data sources of the GIS large scale spatial database updating. The realization of the building information monitoring using the high resolution remote sensing, building small scale information extracting and its quality analyzing has become an important precondition for the applying of the high-resolution satellite image information, because of the large amount of regional high spatial resolution satellite image data. In this paper, a clustering segmentation classification evaluation method for the high resolution satellite images of the typical rural buildings is proposed based on the traditional KMeans clustering algorithm. The factors of separability and building density were used for describing image classification characteristics of clustering window. The sensitivity of the factors influenced the clustering result was studied from the perspective of the separability between high image itself target and background spectrum. This study showed that the number of the sample contents is the important influencing factor to the clustering accuracy and performance, the pixel ratio of the objects in images and the separation factor can be used to determine the specific impact of cluster-window subsets on the clustering accuracy, and the count of window target pixels (Nw) does not alone affect clustering accuracy. The result can provide effective research reference for the quality assessment of the segmentation and classification of high spatial resolution remote sensing images.

  20. Swing arm profilometer: high accuracy testing for large reaction-bonded silicon carbide optics with a capacitive probe

    Science.gov (United States)

    Xiong, Ling; Luo, Xiao; Hu, Hai-xiang; Zhang, Zhi-yu; Zhang, Feng; Zheng, Li-gong; Zhang, Xue-jun

    2017-08-01

    A feasible way to improve the manufacturing efficiency of large reaction-bonded silicon carbide optics is to increase the processing accuracy in the ground stage before polishing, which requires high accuracy metrology. A swing arm profilometer (SAP) has been used to measure large optics during the ground stage. A method has been developed for improving the measurement accuracy of SAP using a capacitive probe and implementing calibrations. The experimental result compared with the interferometer test shows the accuracy of 0.068 μm in root-mean-square (RMS) and maps in 37 low-order Zernike terms show accuracy of 0.048 μm RMS, which shows a powerful capability to provide a major input in high-precision grinding.

  1. [Diagnostic accuracy of the immersion high-frequency B-scan ultrasonography in chemical injured eyes].

    Science.gov (United States)

    Yang, Qinghua; Chen, Bing; Wang, Liqiang; Li, Zhaohui; Huang, Yifei

    2014-08-01

    To investigate the diagnostic accuracy of the immersion high-frequency B-scan ultrasonography, a noninvasive preoperative diagnosis method, in observing the anterior segment in chemical injured eyes. It was a retrospective study. Sixty-three ocular chemical injury patients (63 eyes), who accepted the keratoplasty or the artificial cornea transplant in PLA General Hospital from May 2011 to May 2013, were included in this study. All the injured eyes were examined by ultrasound bio-microscopy (UBM) and immersion high-frequency B-scan ultrasonography, respectively. The images were analyzed and the results were compared with the intraoperative findings. The observation of lens was the main parameter. All the 63 patients were examined with the UBM and the immersion high-frequency B-scan ultrasonography before the surgery. The findings of the cornea, anterior chamber angle, iris from UBM were consistent with those from the immersion high-frequency B-scan ultrasonography. As for the lens observation, in 32 eyes in which the lens were not detected by UBM, the lens were not detected in only 16 eyes, while 3 eyes with normal lens and 13 eyes with lens pacifications (1 eye with pyknotic lens) by immersion high-frequency B-scan ultrasonography. In 17 eyes in which the lens were found normal by UBM, there were only 14 eyes with normal lens and the rest 3 eyes' lens were found intumescent by immersion high-frequency B-scan ultrasonography. In 6 eyes in which lens were detected with suspicious by UBM, 2 eyes' lens were pyknotic and 4 eyes' lens were intumescent or clouded by immersion high-frequency B-scan ultrasonography. The findings of immersion high-frequency B-scan ultrasonography were highly consistent with the intraoperative findings. The lens could be observed accurately by immersion high-frequency B-scan ultrasonography in chemical injured eyes.

  2. High-accuracy infra-red thermography method using reflective marker arrays

    Science.gov (United States)

    Kirollos, Benjamin; Povey, Thomas

    2017-09-01

    In this paper, we describe a new method for high-accuracy infra-red (IR) thermography measurements in situations with significant spatial variation in reflected radiation from the surroundings, or significant spatial variation in surface emissivity due to viewing angle non-uniformity across the field of view. The method employs a reflective marker array (RMA) on the target surface—typically, high emissivity circular dots—and an integrated image analysis algorithm designed to require minimal human input. The new technique has two particular advantages which make it suited to high-accuracy measurements in demanding environments: (i) it allows the reflected radiation component to be calculated directly, in situ, and as a function of position, overcoming a key problem in measurement environments with non-uniform and unsteady stray radiation from the surroundings; (ii) using image analysis of the marker array (via apparent aspect ratio of the circular reflective markers), the local viewing angle of the target surface can be estimated, allowing corrections for angular variation of local emissivity to be performed without prior knowledge of the geometry. A third advantage of the technique is that allows for simple focus-stacking algorithms due to increased image entropy. The reflective marker array method is demonstrated for an isothermal, hemispherical object exposed to an external IR source arranged to give a significant non-uniform reflected radiation term. This is an example of a challenging environment, both because of the significant non-uniform reflected radiation term, and also the significant variation in target emissivity due to surface angle variation. We demonstrate that the new RMA IR technique leads to significantly lower error in evaluated surface temperature than conventional IR techniques. The method is applicable to any complex radiative environment.

  3. Astronomical calibration of 40Ar/39Ar reference minerals using high-precision, multi-collector (ARGUSVI) mass spectrometry

    Science.gov (United States)

    Phillips, D.; Matchan, E. L.; Honda, M.; Kuiper, K. F.

    2017-01-01

    The new generation of multi-collector mass spectrometers (e.g. ARGUSVI) permit ultra-high precision (1%) in 40K decay constants and the ages of natural reference minerals that form the basis of the technique. For example, reported ages for widely used 40Ar/39Ar reference materials, such as the ca. 28 Ma Fish Canyon Tuff sanidine (FCTs) and the ca. 1.2 Ma Alder Creek Rhyolite sanidine (ACRs), vary by >1%. Recent attempts to independently calibrate these reference minerals have focused on K-Ar analyses of the same minerals and inter-comparisons with astronomically tuned tephras in sedimentary sequences and U-Pb zircon ages from volcanic rocks. Most of these studies used older generation (effectively single-collector) mass spectrometers that employed peak-jumping analytical methods to acquire 40Ar/39Ar data. In this study, we reassess the inter-calibration and ages of commonly used 40Ar/39Ar reference minerals Fish Canyon Tuff sanidine (FCTs), Alder Creek Rhyolite sanidine (ACRs) and Mount Dromedary biotite (MD2b; equivalent to GA-1550 biotite), relative to the astronomically tuned age of A1 Tephra sanidine (A1Ts), Faneromeni section, Crete (Rivera et al., 2011), using a multi-collector ARGUSVI mass spectrometer. These analyses confirm the exceptional precision capability (0.1% in the 40Ar/39Ar ages of reference minerals without consideration of recoil artefacts, thus limiting the benefits of high precision multi-collector analyses. Significant improvement to the accuracy of the 40Ar/39Ar method (<0.1%) will require further inter-laboratory 40Ar/39Ar studies utilizing multi-collector mass spectrometry, additional constraints on recoil 39ArK loss from reference minerals, further resolution of discrepancies between astronomically tuned sedimentary successions and refinement of the 238U/206Pb zircon age cross-calibration approach.

  4. Design and calibration of a high-sensitivity and high-accuracy polarimeter based on liquid crystal variable retarders

    Science.gov (United States)

    Guo, Jing; Ren, De-Qing; Liu, Cheng-Chao; Zhu, Yong-Tian; Dou, Jiang-Pei; Zhang, Xi; Beck, Christian

    2017-01-01

    Polarimetry plays an important role in the measurement of solar magnetic fields. We developed a high-sensitivity and high-accuracy polarimeter (HHP) based on nematic liquid crystal variable retarders (LCVRs), which has a compact setup and no mechanical moving parts. The system design and calibration methods are discussed in detail. The azimuth error of the transmission axis of the polarizer as well as the fast axes of the two LCVRs and the quarter-wave plate were determined using dedicated procedures. Linearly and circularly polarized light were employed to evaluate the performance of the HHP. The experimental results indicate that a polarimetric sensitivity of better than \\[5.7 × {10 - 3}\\] can be achieved by using a single short-exposure image, while an accuracy on the order of 10‑5 can be reached by using a large number of short-exposure images. This makes the HHP a high-performance system that can be used with a ground-based solar telescope for high-precision solar magnetic field investigations.

  5. Very Low Power, Low Voltage, High Accuracy, and High Performance Current Mirror

    Institute of Scientific and Technical Information of China (English)

    Hassan Faraji Baghtash; Khalil Monfaredi; Ahmad Ayatollahi

    2011-01-01

    A novel low power and low voltage current mirror with a very low current copy error is presented and the principle of its operation is discussed.In this circuit,the gain boosting regulated cascode scheme is used to improve the output resistance,while using inverter as an amplifier.The simulation results with HSPICE in TSMC 0.18 μm CMOS technology are given,which verify the high performance of the proposed structure.Simulation results show an input resistance of 0.014 Ω and an output resistance of 3 GΩ.The current copy error is favorable as low as 0.002% together with an input (the minimum input voltage of vin,min~ 0.24 V) and an output (the minimum output voltage of vout,min~ 0.16 V) compliances while working with the 1 V power supply and the 50 μA input current.The current copy error is near zero at the input current of 27 μA.It consumes only 76 μW and introduces a very low output offset current of 50 pA.

  6. ADFE METHOD WITH HIGH ACCURACY FOR NONLINEAR PARABOLIC INTEGRO-DIFFERENTIAL SYSTEM WITH NONLINEAR BOUNDARY CONDITIONS

    Institute of Scientific and Technical Information of China (English)

    崔霞

    2002-01-01

    Alternating direction finite element (ADFE) scheme for d-dimensional nonlinear system of parabolic integro-differential equations is studied. By using a local approximation based on patches of finite elements to treat the capacity term qi(u), decomposition of the coefficient matrix is realized; by using alternating direction, the multi-dimensional problem is reduced to a family of single space variable problems, calculation work is simplified; by using finite element method, high accuracy for space variant is kept; by using inductive hypothesis reasoning, the difficulty coming from the nonlinearity of the coefficients and boundary conditions is treated; by introducing Ritz-Volterra projection, the difficulty coming from the memory term is solved. Finally, by using various techniques for priori estimate for differential equations, the unique resolvability and convergence properties for both FE and ADFE schemes are rigorously demonstrated, and optimal H1 and L2norm space estimates and O((△t)2) estimate for time variant are obtained.

  7. SLSTR: a high accuracy dual scan temperature radiometer for sea and land surface monitoring from space

    Science.gov (United States)

    Coppo, P.; Ricciarelli, B.; Brandani, F.; Delderfield, J.; Ferlet, M.; Mutlow, C.; Munro, G.; Nightingale, T.; Smith, D.; Bianchi, S.; Nicol, P.; Kirschstein, S.; Hennig, T.; Engel, W.; Frerick, J.; Nieke, J.

    2010-10-01

    SLSTR is a high accuracy infrared radiometer which will be embarked in the Earth low-orbit Sentinel 3 operational GMES mission. SLSTR is an improved version of the previous AATSR and ATSR-1/2 instruments which have flown respectively on Envisat and ERS-1/2 ESA missions. SLSTR will provide data continuity with respect to these previous missions but with a substantial improvement due to its higher swaths (750 km in dual view and 1400 km in single view) which should permit global coverage of SST and LST measurements (at 1 km of spatial resolution in IR channels) with daily revisit time, useful for climatological and meteorological applications. Two more SWIR channels and a higher spatial resolution in the VIS/SWIR channels (0.5 km) are also implemented for a better clouds/aerosols screening. Two further additional channels for global scale fire monitoring are present at the same time as the other nominal channels.

  8. Study on Calibration System for Electronic Transformers Based on High-Accuracy PCI Card

    Directory of Open Access Journals (Sweden)

    Mingzhu Zhang

    2013-03-01

    Full Text Available With preliminary applying of Electronic Transformer (ET based on IEC 61850 standards in power grid, the calibrations of tested transformers have attracted extensive research attention. This study proposes a novel Calibration System of ET (CSET based on high-accuracy card. Data acquisition of ET and Standard Trans-former (ST is gotten by optic Ethernet and PCI-4462 data acquisition card, respectively. Meanwhile, the synchronized sampling between ET and ST is completed on the optic/electronic pulse signal of PCI synchronization card. The signals processing and human interface are realized by Labview software. The system proposed in the study is feasible for calibrating Electronic Voltage/Current Transformers (EVT/ECT of different voltage classes. System tests show that the precision of the system can get to 0.2°.

  9. Study on Calibration System for Electronic Transformers Based on High-Accuracy PCI Card

    Directory of Open Access Journals (Sweden)

    Mingzhu Zhang

    2013-05-01

    Full Text Available With preliminary applying of Electronic Transformer (ET based on IEC 61850 standards in power grid, the calibration of tested transformers has attracted extensive research attention. This study proposes a novel Calibration System of ET (CSET based on high-accuracy card. Data acquisition of ET and standard trans-former (ST is gotten by optic Ethernet and PCI-4462 data acquisition card, respectively. Meanwhile, the synchronized sampling between ET and ST is completed on the optic/electronic pulse signal of PCI synchronization card. The signals processing and human interface are realized by Lab view software. The system proposed in the study is feasible for calibrating Electronic Voltage/Current Transformers (EVT/ECT of different voltage classes. System tests show that the precision of the system can get to 0.2°.

  10. Well-posedness of the difference schemes of the high order of accuracy for elliptic equations

    Directory of Open Access Journals (Sweden)

    2006-01-01

    Full Text Available It is well known the differential equation − u ″ ( t +Au( t =f( t ( −∞high order of accuracy two-step difference schemes generated by an exact difference scheme or by Taylor's decomposition on three points for the approximate solutions of this differential equation. The well-posedness of these difference schemes in the difference analogy of the smooth functions is obtained. The exact almost coercive inequality for solutions in C( τ,E of these difference schemes is established.

  11. High-accuracy measurement of the magnetic moment anomaly of the electron bound in hydrogenlike carbon.

    Science.gov (United States)

    Häffner, H; Beier, T; Hermanspahn, N; Kluge, H J; Quint, W; Stahl, S; Verdú, J; Werth, G

    2000-12-18

    We present a new experimental value for the magnetic moment of the electron bound in hydrogenlike carbon (12C5+): g(exp) = 2.001 041 596 (5). This is the most precise determination of an atomic g(J) factor so far. The experiment was carried out on a single 12C5+ ion stored in a Penning trap. The high accuracy was made possible by spatially separating the induction of spin flips and the analysis of the spin direction. The current theoretical value amounts to g(th) = 2.001 041 591 (7). Together experiment and theory test the bound-state QED contributions to the g(J) factor of a bound electron to a precision of 1%.

  12. Computer-aided diagnosis of breast MRI with high accuracy optical flow estimation

    Science.gov (United States)

    Meyer-Baese, Anke; Barbu, Adrian; Lobbes, Marc; Hoffmann, Sebastian; Burgeth, Bernhard; Kleefeld, Andreas; Meyer-Bäse, Uwe

    2015-05-01

    Non-mass enhancing lesions represent a challenge for the radiological reading. They are not well-defined in both morphology (geometric shape) and kinetics (temporal enhancement) and pose a problem to lesion detection and classification. To enhance the discriminative properties of an automated radiological workflow, the correct preprocessing steps need to be taken. In an usual computer-aided diagnosis (CAD) system, motion compensation plays an important role. To this end, we employ a new high accuracy optical flow based motion compensation algorithm with robustification variants. An automated computer-aided diagnosis system evaluates the atypical behavior of these lesions, and additionally considers the impact of non-rigid motion compensation on a correct diagnosis.

  13. High Accuracy Speed-fed Grating Angular Acceleration Measurement System Based on FPGA

    Directory of Open Access Journals (Sweden)

    Hao Zhao

    2012-09-01

    Full Text Available Shaft angular acceleration is one of the most important parameter of rotary machines, the error of angular acceleration increased when the shaft speed up. For this problem, a new high accuracy angular acceleration measurement system is presented, the principle of measurement is self-regulating the period of speed sampling signal according to the proportion of the shaft speed up. This measurement system combined FPGA and SCM, the speed of shaft is received by the timer of SCM responding the interrupts of FPGA, and then set the parameter of frequency divider in FPGA, so as to make the period of speed sampling consistent with the proportion of the speed up. This measurement system could overcome the error when system speed up according to the experiment.

  14. High-accuracy approximation of high-rank derivatives: isotropic finite differences based on lattice-Boltzmann stencils.

    Science.gov (United States)

    Mattila, Keijo Kalervo; Hegele Júnior, Luiz Adolfo; Philippi, Paulo Cesar

    2014-01-01

    We propose isotropic finite differences for high-accuracy approximation of high-rank derivatives. These finite differences are based on direct application of lattice-Boltzmann stencils. The presented finite-difference expressions are valid in any dimension, particularly in two and three dimensions, and any lattice-Boltzmann stencil isotropic enough can be utilized. A theoretical basis for the proposed utilization of lattice-Boltzmann stencils in the approximation of high-rank derivatives is established. In particular, the isotropy and accuracy properties of the proposed approximations are derived directly from this basis. Furthermore, in this formal development, we extend the theory of Hermite polynomial tensors in the case of discrete spaces and present expressions for the discrete inner products between monomials and Hermite polynomial tensors. In addition, we prove an equivalency between two approaches for constructing lattice-Boltzmann stencils. For the numerical verification of the presented finite differences, we introduce 5th-, 6th-, and 8th-order two-dimensional lattice-Boltzmann stencils.

  15. Study of high-altitude radar altimeter model accuracy and SITAN performance using HAAFT data

    Energy Technology Data Exchange (ETDEWEB)

    Shieves, T.C.; Callahan, M.W.

    1979-07-01

    Radar altimetry data, inertial navigation data, and scoring data were collected under the HAAFT program by Martin Marietta Corporation for the United States Air Force over several areas in the western United States at altitudes ranging from 3 to 20 km. The study reported here uses the HAAFT data in conjunction with Defense Mapping Agency (DMA) topographic data to evaluate the accuracy of a high-altitude pulsed-radar altimeter model and the resulting performance of the terrain-aided guidance concept SITAN. Previous SITAN flight tests at low altitudes (less than 1500 m AGL) have demonstrated 6-20 m CEP. The high-altitude flight test data analyzed herein show a SITAN CEP of 120 m. The radar altimeter model was required to achieve this performance includes the effects of the internal track loop, AGC loop, antenna beamwidth, and the terrain radar cross section and provided a factor of 6 improvement over simple nadir ground clearance for rough terrain. It is postulated that high-altitude CEP could be reduced to 50 m or less if an altimeter were designed specifically for high-altitude terrain sensing.

  16. TECHNOLOGICAL PROVISION OF ACCURACY AND QUALITY PARAMETERS OF INTRICATE PROFILE PARTS AT HIGH-SPEED MULTI-COORDINATE MACHINING

    Directory of Open Access Journals (Sweden)

    V. K. Sheleg

    2009-01-01

    Full Text Available The paper considers requirements to CAM-systems for provision of high-speed multi-coordinate milling, principles of generation and recommendations on trajectory programming for high-speed machining, influence of vibration and balancing of the technological system on parameters of  the machining accuracy, characteristics of a cutting tool, types of tool coatings that is rather actual for improvement of accuracy and quality of intricate profile parts.

  17. Cost-effective improvements of a rotating platform by integration of a high-accuracy inclinometer and encoders for attitude evaluation

    Science.gov (United States)

    Wen, Chenyang; He, Shengyang; Bu, Changgen; Hu, Peida

    2017-01-01

    Attitude heading reference systems (AHRSs) based on micro-electromechanical system (MEMS) inertial sensors are widely used because of their low cost, light weight, and low power. However, low-cost AHRSs suffer from large inertial sensor errors. Therefore, experimental performance evaluation of MEMS-based AHRSs after system implementation is necessary. High-accuracy turntables can be used to verify the performance of MEMS-based AHRSs indoors, but they are expensive and unsuitable for outdoor tests. This study developed a low-cost two-axis rotating platform for indoor and outdoor attitude determination. A high-accuracy inclinometer and encoders were integrated into the platform to improve the achievable attitude test accuracy. An attitude error compensation method was proposed to calibrate the initial attitude errors caused by the movements and misalignment angles of the platform. The proposed attitude error determination method was examined through rotating experiments, which showed that the standard deviations of the pitch and roll errors were 0.050° and 0.090°, respectively. The pitch and roll errors both decreased to 0.024° when the proposed attitude error determination method was used. This decrease validates the effectiveness of the compensation method. Experimental results demonstrated that the integration of the inclinometer and encoders improved the performance of the low-cost, two-axis, rotating platform in terms of attitude accuracy.

  18. DESIGN OF A CMOS BANDGAP REFERENCE WITH LOWTEMPERATURE COEFFICIENT AND HIGH POWER SUPPLY REJECTION PERFORMANCE

    OpenAIRE

    Abhisek Dey; Tarun Kanti Bhattacharyya

    2011-01-01

    A high precision temperature compensated CMOS bandgap reference is presented. The proposed circuit employs current-mode architecture that improves the temperature stability of the output reference voltage as well as the power supply rejection when compared to the conventional voltage-mode band gap reference.Using only first order compensation the new architecture can generate an output reference voltage of 550 mV with a peak-to-peak variation of 400μV over a wide temperature range from -25oC ...

  19. Path Generation for High-Performance Motion of ROVs Based on a Reference Model

    Directory of Open Access Journals (Sweden)

    Daniel de A. Fernandes

    2015-04-01

    Full Text Available This paper deals with the generation of sufficiently smooth position, velocity, and acceleration references for guiding the motion of an ROV along purposefully defined curvature-continuous paths in automated missions. The references are meant to be employed in high-performance trajectory tracking and dynamic positioning applications. The path planning problem is not in the scope of this work. A reference model that synthesises references concerning a single Degree-of-Freedom (DoF motion is initially described. Then, the use of the synthesised references as the parametrisation for other references concerning multiple DoF motion along curvature-continuous paths is exploited. Results from computer simulations and full-scale sea trials, both based on the NTNU's ROV Minerva, are presented and discussed.

  20. Integrative fitting of absorption line profiles with high accuracy, robustness, and speed

    Science.gov (United States)

    Skrotzki, Julian; Habig, Jan Christoph; Ebert, Volker

    2014-08-01

    The principle of the integrative evaluation of absorption line profiles relies on the numeric integration of absorption line signals to retrieve absorber concentrations, e.g., of trace gases. Thus, it is a fast and robust technique. However, previous implementations of the integrative evaluation principle showed shortcomings in terms of accuracy and the lack of a fit quality indicator. This has motivated the development of an advanced integrative (AI) fitting algorithm. The AI fitting algorithm retains the advantages of previous integrative implementations—robustness and speed—and is able to achieve high accuracy by introduction of a novel iterative fitting process. A comparison of the AI fitting algorithm with the widely used Levenberg-Marquardt (LM) fitting algorithm indicates that the AI algorithm has advantages in terms of robustness due to its independence from appropriately chosen start values for the initialization of the fitting process. In addition, the AI fitting algorithm shows speed advantages typically resulting in a factor of three to four shorter computational times on a standard personal computer. The LM algorithm on the other hand retains advantages in terms of a much higher flexibility, as the AI fitting algorithm is restricted to the evaluation of single absorption lines with precomputed line width. Comparing both fitting algorithms for the specific application of in situ laser hygrometry at 1,370 nm using direct tunable diode laser absorption spectroscopy (TDLAS) suggests that the accuracy of the AI algorithm is equivalent to that of the LM algorithm. For example, a signal-to-noise ratio of 80 and better typically yields a deviation of TDLAS hygrometry at the aerosol and cloud chamber aerosol interactions and dynamics in the atmosphere (AIDA)—a unique large-scale facility to study atmospheric processes. The robustness of the AI fitting algorithm has been validated for typical AIDA conditions encompassing strong transmission fluctuations

  1. Improved photomask accuracy with a high-productivity DUV laser pattern generator

    Science.gov (United States)

    Öström, Thomas; Måhlén, Jonas; Karawajczyk, Andrzej; Rosling, Mats; Carlqvist, Per; Askebjer, Per; Karlin, Tord; Sallander, Jesper; Österberg, Anders

    2006-10-01

    A strategy for sub-100 nm technology nodes is to maximize the use of high-speed deep-UV laser pattern generators, reserving e-beam tools for the most critical photomask layers. With a 248 nm excimer laser and 0.82 NA projection optics, the Sigma7500 increases the application space of laser pattern generators. A programmable spatial light modulator (SLM) is imaged with partially coherent optics to compose the photomask pattern. Image profiles are enhanced with phase shifting in the pattern generator, and features below 200 nm are reliably printed. The Sigma7500 extends the SLM-based architecture with improvements to CD uniformity and placement accuracy, resulting from an error budget-based methodology. Among these improvements is a stiffer focus stage design with digital servos, resulting in improved focus stability. Tighter climate controls and improved dose control reduce drift during mask patterning. As a result, global composite CD uniformity below 5 nm (3σ) has been demonstrated, with placement accuracy below 10 nm (3σ) across the mask. Self-calibration methods are used to optimize and monitor system performance, reducing the need to print test plates. The SLM calibration camera views programmed test patterns, making it possible to evaluate image metrics such as CD uniformity and line edge roughness. The camera is also used to characterize image placement over the optical field. A feature called ProcessEqualizer TM has been developed to correct long-range CD errors arising from process effects on production photomasks. Mask data is sized in real time to compensate for pattern-dependent errors related to local pattern density, as well as for systematic pattern-independent errors such as radial CD signatures. Corrections are made in the pixel domain in the advanced adjustments processor, which also performs global biasing, stamp distortion compensation, and corner enhancement. In the Sigma7500, the mask pattern is imaged with full edge addressability in each

  2. A new device for liver cancer biomarker detection with high accuracy

    Directory of Open Access Journals (Sweden)

    Shuaipeng Wang

    2015-06-01

    Full Text Available A novel cantilever array-based bio-sensor was batch-fabricated with IC compatible MEMS technology for precise liver cancer bio-marker detection. A micro-cavity was designed in the free end of the cantilever for local antibody-immobilization, thus adsorption of the cancer biomarker is localized in the micro-cavity, and the adsorption-induced k variation can be dramatically reduced with comparison to that caused by adsorption of the whole lever. The cantilever is pizeoelectrically driven into vibration which is pizeoresistively sensed by Wheatstone bridge. These structural features offer several advantages: high sensitivity, high throughput, high mass detection accuracy, and small volume. In addition, an analytical model has been established to eliminate the effect of adsorption-induced lever stiffness change and has been applied to precise mass detection of cancer biomarker AFP, the detected AFP antigen mass (7.6 pg/ml is quite close to the calculated one (5.5 pg/ml, two orders of magnitude better than the value by the fully antibody-immobilized cantilever sensor. These approaches will promote real application of the cantilever sensors in early diagnosis of cancer.

  3. High Accuracy Decoding of Dynamical Motion from a Large Retinal Population.

    Directory of Open Access Journals (Sweden)

    Olivier Marre

    2015-07-01

    Full Text Available Motion tracking is a challenge the visual system has to solve by reading out the retinal population. It is still unclear how the information from different neurons can be combined together to estimate the position of an object. Here we recorded a large population of ganglion cells in a dense patch of salamander and guinea pig retinas while displaying a bar moving diffusively. We show that the bar's position can be reconstructed from retinal activity with a precision in the hyperacuity regime using a linear decoder acting on 100+ cells. We then took advantage of this unprecedented precision to explore the spatial structure of the retina's population code. The classical view would have suggested that the firing rates of the cells form a moving hill of activity tracking the bar's position. Instead, we found that most ganglion cells in the salamander fired sparsely and idiosyncratically, so that their neural image did not track the bar. Furthermore, ganglion cell activity spanned an area much larger than predicted by their receptive fields, with cells coding for motion far in their surround. As a result, population redundancy was high, and we could find multiple, disjoint subsets of neurons that encoded the trajectory with high precision. This organization allows for diverse collections of ganglion cells to represent high-accuracy motion information in a form easily read out by downstream neural circuits.

  4. High accuracy and precision micro injection moulding of thermoplastic elastomers micro ring production

    DEFF Research Database (Denmark)

    Calaon, Matteo; Tosello, Guido; Elsborg, René

    2016-01-01

    of using tool geometries as reference calibrated artefacts to establish effective process technology development and control. The results allow identifying the correct process windows for optimal part quality reducing product dimensional variation in the micrometer dimensional range. The proposed......The mass-replication nature of the process calls for fast monitoring of process parameters and product geometrical characteristics. In this direction, the present study addresses the possibility to develop a micro manufacturing platform for micro assembly injection moulding with real-time process/product...... monitoring and metrology. The study represent a new concept yet to be developed with great potential for high precision mass-manufacturing of highly functional 3D multi-material (i.e. including metal/soft polymer) micro components. The activities related to HINMICO project objectives proves the importance...

  5. High Accuracy Potential Energy Surface, Dipole Moment Surface, Rovibrational Energies and Line List Calculations for ^{14}NH_3

    Science.gov (United States)

    Coles, Phillip; Yurchenko, Sergei N.; Polyansky, Oleg; Kyuberis, Aleksandra; Ovsyannikov, Roman I.; Zobov, Nikolay Fedorovich; Tennyson, Jonathan

    2017-06-01

    We present a new spectroscopic potential energy surface (PES) for ^{14}NH_3, produced by refining a high accuracy ab initio PES to experimental energy levels taken predominantly from MARVEL. The PES reproduces 1722 matched J=0-8 experimental energies with a root-mean-square error of 0.035 cm-1 under 6000 cm^{-1} and 0.059 under 7200 cm^{-1}. In conjunction with a new DMS calculated using multi reference configuration interaction (MRCI) and H=aug-cc-pVQZ, N=aug-cc-pWCVQZ basis sets, an infrared (IR) line list has been computed which is suitable for use up to 2000 K. The line list is used to assign experimental lines in the 7500 - 10,500 cm^{-1} region and previously unassigned lines in HITRAN in the 6000-7000 cm^{-1} region. Oleg L. Polyansky, Roman I. Ovsyannikov, Aleksandra A. Kyuberis, Lorenzo Lodi, Jonathan Tennyson, Andrey Yachmenev, Sergei N. Yurchenko, Nikolai F. Zobov, J. Mol. Spec., 327 (2016) 21-30 Afaf R. Al Derzia, Tibor Furtenbacher, Jonathan Tennyson, Sergei N. Yurchenko, Attila G. Császár, J. Quant. Spectrosc. Rad. Trans., 161 (2015) 117-130

  6. Model Accuracy Comparison for High Resolution Insar Coherence Statistics Over Urban Areas

    Science.gov (United States)

    Zhang, Yue; Fu, Kun; Sun, Xian; Xu, Guangluan; Wang, Hongqi

    2016-06-01

    The interferometric coherence map derived from the cross-correlation of two complex registered synthetic aperture radar (SAR) images is the reflection of imaged targets. In many applications, it can act as an independent information source, or give additional information complementary to the intensity image. Specially, the statistical properties of the coherence are of great importance in land cover classification, segmentation and change detection. However, compared to the amount of work on the statistical characters of SAR intensity, there are quite fewer researches on interferometric SAR (InSAR) coherence statistics. And to our knowledge, all of the existing work that focuses on InSAR coherence statistics, models the coherence with Gaussian distribution with no discrimination on data resolutions or scene types. But the properties of coherence may be different for different data resolutions and scene types. In this paper, we investigate on the coherence statistics for high resolution data over urban areas, by making a comparison of the accuracy of several typical statistical models. Four typical land classes including buildings, trees, shadow and roads are selected as the representatives of urban areas. Firstly, several regions are selected from the coherence map manually and labelled with their corresponding classes respectively. Then we try to model the statistics of the pixel coherence for each type of region, with different models including Gaussian, Rayleigh, Weibull, Beta and Nakagami. Finally, we evaluate the model accuracy for each type of region. The experiments on TanDEM-X data show that the Beta model has a better performance than other distributions.

  7. 10 kHz accuracy of an optical frequency reference based on (12)C2H2-filled large-core kagome photonic crystal fibers.

    Science.gov (United States)

    Knabe, Kevin; Wu, Shun; Lim, Jinkang; Tillman, Karl A; Light, Philip S; Couny, Francois; Wheeler, Natalie; Thapa, Rajesh; Jones, Andrew M; Nicholson, Jeffrey W; Washburn, Brian R; Benabid, Fetah; Corwin, Kristan L

    2009-08-31

    Saturated absorption spectroscopy reveals the narrowest features so far in molecular gas-filled hollow-core photonic crystal fiber. The 48-68 mum core diameter of the kagome-structured fiber used here allows for 8 MHz full-width half-maximum sub-Doppler features, and its wavelength-insensitive transmission is suitable for high-accuracy frequency measurements. A fiber laser is locked to the (12)C2H2 nu(1); + nu(3) P(13) transition inside kagome fiber, and compared with frequency combs based on both a carbon nanotube fiber laser and a Cr:forsterite laser, each of which are referenced to a GPS-disciplined Rb oscillator. The absolute frequency of the measured line center agrees with those measured in power build-up cavities to within 9.3 kHz (1 sigma error), and the fractional frequency instability is less than 1.2 x 10(-11) at 1 s averaging time.

  8. Prioritizing spatial accuracy in high-resolution fMRI data using multivariate feature weight mapping

    Directory of Open Access Journals (Sweden)

    Johannes eStelzer

    2014-04-01

    Full Text Available Although ultra-high-field fMRI at field strengths of 7T or above provides substantial gains in BOLD contrast-to-noise ratio, when very high-resolution fMRI is required such gains are inevitably reduced. The improvement in sensitivity provided by multivariate analysis techniques, as compared with univariate methods, then becomes especially welcome. Information mapping approaches are commonly used, such as the searchlight technique, which take into account the spatially distributed patterns of activation in order to predict stimulus conditions. However, the popular searchlight decoding technique, in particular, has been found to be prone to spatial inaccuracies. For instance, the spatial extent of informative areas is generally exaggerated, and their spatial configuration is distorted. We propose the combination of a nonparametric and permutation-based statistical framework with linear classifiers. We term this new combined method Feature Weight Mapping (FWM. The main goal of the proposed method is to map the specific contribution of each voxel to the classification decision while including a correction for the multiple comparisons problem. Next, we compare this new method to the searchlight approach using a simulation and ultra-high-field 7T experimental data. We found that the searchlight method led to spatial inaccuracies that are especially noticeable in high-resolution fMRI data. In contrast, FWM was more spatially precise, revealing both informative anatomical structures as well as the direction by which voxels contribute to the classification. By maximizing the spatial accuracy of ultra-high-field fMRI results, global multivariate methods provide a substantial improvement for characterizing structure-function relationships.

  9. High-resolution CT of nontuberculous mycobacterium infection in adult CF patients: diagnostic accuracy

    Energy Technology Data Exchange (ETDEWEB)

    McEvoy, Sinead; Lavelle, Lisa; Kilcoyne, Aoife; McCarthy, Colin; Dodd, Jonathan D. [St. Vincent' s University Hospital, Department of Radiology, Dublin (Ireland); DeJong, Pim A. [University Medical Center Utrecht, Department of Radiology, Utrecht (Netherlands); Loeve, Martine; Tiddens, Harm A.W.M. [Erasmus MC-Sophia Children' s Hospital, Department of Radiology, Department of Pediatric Pulmonology and Allergology, Rotterdam (Netherlands); McKone, Edward; Gallagher, Charles G. [St. Vincent' s University Hospital, Department of Respiratory Medicine and National Referral Centre for Adult Cystic Fibrosis, Dublin (Ireland)

    2012-12-15

    To determine the diagnostic accuracy of high-resolution computed tomography (HRCT) for the detection of nontuberculous mycobacterium infection (NTM) in adult cystic fibrosis (CF) patients. Twenty-seven CF patients with sputum-culture-proven NTM (NTM+) underwent HRCT. An age, gender and spirometrically matched group of 27 CF patients without NTM (NTM-) was included as controls. Images were randomly and blindly analysed by two readers in consensus and scored using a modified Bhalla scoring system. Significant differences were seen between NTM (+) and NTM (-) patients in the severity of the bronchiectasis subscore [45 % (1.8/4) vs. 35 % (1.4/4), P = 0.029], collapse/consolidation subscore [33 % (1.3/3) vs. 15 % (0.6/3)], tree-in-bud/centrilobular nodules subscore [43 % (1.7/3) vs. 25 % (1.0/3), P = 0.002] and the total CT score [56 % (18.4/33) vs. 46 % (15.2/33), P = 0.002]. Binary logistic regression revealed BMI, peribronchial thickening, collapse/consolidation and tree-in-bud/centrilobular nodules to be predictors of NTM status (R{sup 2} = 0.43). Receiver-operator curve analysis of the regression model showed an area under the curve of 0.89, P < 0.0001. In adults with CF, seven or more bronchopulmonary segments showing tree-in-bud/centrilobular nodules on HRCT is highly suggestive of NTM colonisation. (orig.)

  10. Rigorous Training of Dogs Leads to High Accuracy in Human Scent Matching-To-Sample Performance.

    Directory of Open Access Journals (Sweden)

    Sophie Marchal

    Full Text Available Human scent identification is based on a matching-to-sample task in which trained dogs are required to compare a scent sample collected from an object found at a crime scene to that of a suspect. Based on dogs' greater olfactory ability to detect and process odours, this method has been used in forensic investigations to identify the odour of a suspect at a crime scene. The excellent reliability and reproducibility of the method largely depend on rigor in dog training. The present study describes the various steps of training that lead to high sensitivity scores, with dogs matching samples with 90% efficiency when the complexity of the scents presented during the task in the sample is similar to that presented in the in lineups, and specificity reaching a ceiling, with no false alarms in human scent matching-to-sample tasks. This high level of accuracy ensures reliable results in judicial human scent identification tests. Also, our data should convince law enforcement authorities to use these results as official forensic evidence when dogs are trained appropriately.

  11. High accuracy jog CD control on OPC pattern by advanced laser writer Sigma7500

    Science.gov (United States)

    Chin, Tomas; Wu, Wen-Bin; Shih, Chiang-Lin

    2008-10-01

    With the progress of mask writer technology, 50 KV electron beam writers always perform with better pattern fidelity and critical dimension (CD) control than traditional laser raster-scan writers because laser spot size is confined by the laser longer wavelength relative to electron beam. As far as Optical Proximity Correction (OPC) pattern fidelity is concerned, critical masks with OPC process have to choose Variable-Shape-Beam (VSB) electron beam writer presently. However, the over-aggressive OPC fragmentation induces data volume abrupt explosion, longer writing time, higher mask cost and even mask quality degradation 1. Micronic Sigma7500 laser writer introduces a novel imaging system combining partial coherent light and DUV spatial light modulation (SLM) to generate a high-quality pattern image 2. The benefit of raster-scan laser writer is high throughput with consistent writing time regardless of pattern geometry, complexity and data size. However, pattern CD accuracy still needs improvement. This study is to evaluate jog CD control capability of Sigma7500 on OPC typical line-and-space test patterns with different orientations of 0°, 90°, 45° and 135°. In addition, mask CD uniformity and OPC jog height linearity will also be demonstrated.

  12. High-Accuracy Ring Laser Gyroscopes: Earth Rotation Rate and Relativistic Effects

    Science.gov (United States)

    Beverini, N.; Di Virgilio, A.; Belfi, J.; Ortolan, A.; Schreiber, K. U.; Gebauer, A.; Klügel, T.

    2016-06-01

    The Gross Ring G is a square ring laser gyroscope, built as a monolithic Zerodur structure with 4 m length on all sides. It has demonstrated that a large ring laser provides a sensitivity high enough to measure the rotational rate of the Earth with a high precision of ΔΩE GINGER project is intending to take this level of sensitivity further and to improve the accuracy and the long-term stability. A monolithic structure similar to the G ring laser is not available for GINGER. Therefore the preliminary goal is the demonstration of the feasibility of a larger gyroscope structure, where the mechanical stability is obtained through an active control of the geometry. A prototype moderate size gyroscope (GP-2) has been set up in Pisa in order to test this active control of the ring geometry, while a second structure (GINGERino) has been installed inside the Gran Sasso underground laboratory in order to investigate the properties of a deep underground laboratory in view of an installation of a future GINGER apparatus. The preliminary data on these two latter instruments are presented.

  13. Spline-based high-accuracy piecewise-polynomial phase-to-sinusoid amplitude converters.

    Science.gov (United States)

    Petrinović, Davor; Brezović, Marko

    2011-04-01

    We propose a method for direct digital frequency synthesis (DDS) using a cubic spline piecewise-polynomial model for a phase-to-sinusoid amplitude converter (PSAC). This method offers maximum smoothness of the output signal. Closed-form expressions for the cubic polynomial coefficients are derived in the spectral domain and the performance analysis of the model is given in the time and frequency domains. We derive the closed-form performance bounds of such DDS using conventional metrics: rms and maximum absolute errors (MAE) and maximum spurious free dynamic range (SFDR) measured in the discrete time domain. The main advantages of the proposed PSAC are its simplicity, analytical tractability, and inherent numerical stability for high table resolutions. Detailed guidelines for a fixed-point implementation are given, based on the algebraic analysis of all quantization effects. The results are verified on 81 PSAC configurations with the output resolutions from 5 to 41 bits by using a bit-exact simulation. The VHDL implementation of a high-accuracy DDS based on the proposed PSAC with 28-bit input phase word and 32-bit output value achieves SFDR of its digital output signal between 180 and 207 dB, with a signal-to-noise ratio of 192 dB. Its implementation requires only one 18 kB block RAM and three 18-bit embedded multipliers in a typical field-programmable gate array (FPGA) device.

  14. High-Accuracy, Compact Scanning Method and Circuit for Resistive Sensor Arrays

    Directory of Open Access Journals (Sweden)

    Jong-Seok Kim

    2016-01-01

    Full Text Available The zero-potential scanning circuit is widely used as read-out circuit for resistive sensor arrays because it removes a well known problem: crosstalk current. The zero-potential scanning circuit can be divided into two groups based on type of row drivers. One type is a row driver using digital buffers. It can be easily implemented because of its simple structure, but we found that it can cause a large read-out error which originates from on-resistance of the digital buffers used in the row driver. The other type is a row driver composed of operational amplifiers. It, very accurately, reads the sensor resistance, but it uses a large number of operational amplifiers to drive rows of the sensor array; therefore, it severely increases the power consumption, cost, and system complexity. To resolve the inaccuracy or high complexity problems founded in those previous circuits, we propose a new row driver which uses only one operational amplifier to drive all rows of a sensor array with high accuracy. The measurement results with the proposed circuit to drive a 4 × 4 resistor array show that the maximum error is only 0.1% which is remarkably reduced from 30.7% of the previous counterpart.

  15. Theory of Relativistic Reference Frames for High-Precision Astrometric Space Missions

    CERN Document Server

    Kopeikin, S M

    2000-01-01

    Recent modern space missions deliver invaluable information about origin of our universe, physical processes in the vicinity of black holes and other exotic astrophysical objects, stellar dynamics of our galaxy, etc. On the other hand, space astrometric missions make it possible to determine with unparalleled precision distances to stars and cosmological objects as well as their physical characteristics and positions on the celestial sphere. Permanently growing accuracy of space astronomical observations and the urgent need for adequate data processing algorithms require corresponding development of an adequate theory of reference frames along with unambiguous description of propagation of light rays from a source of light to observer. Such a theory must be based on the Einstein's general relativity and account for numerous relativistic effects both in the solar system and outside of its boundary. The main features of the relativistic theory of reference frames are presented in this work. A hierarchy of the f...

  16. Assessing the Accuracy of Sentinel-3 SLSTR Sea-Surface Temperature Retrievals Using High Accuracy Infrared Radiiometers on Ships of Opportunity

    Science.gov (United States)

    Minnett, P. J.; Izaguirre, M. A.; Szcszodrak, M.; Williams, E.; Reynolds, R. M.

    2015-12-01

    The assessment of errors and uncertainties in satellite-derived SSTs can be achieved by comparisons with independent measurements of skin SST of high accuracy. Such validation measurements are provided by well-calibrated infrared radiometers mounted on ships. The second generation of Marine-Atmospheric Emitted Radiance Interferometers (M-AERIs) have recently been developed and two are now deployed on cruise ships of Royal Caribbean Cruise Lines that operate in the Caribbean Sea, North Atlantic and Mediterranean Sea. In addition, two Infrared SST Autonomous Radiometers (ISARs) are mounted alternately on a vehicle transporter of NYK Lines that crosses the Pacific Ocean between Japan and the USA. Both M-AERIs and ISARs are self-calibrating radiometers having two internal blackbody cavities to provide at-sea calibration of the measured radiances, and the accuracy of the internal calibration is periodically determined by measurements of a NIST-traceable blackbody cavity in the laboratory. This provides SI-traceability for the at-sea measurements. It is anticipated that these sensors will be deployed during the next several years and will be available for the validation of the SLSTRs on Sentinel-3a and -3b.

  17. Accuracy of the field triage protocol in selecting severely injured patients after high energy trauma.

    Science.gov (United States)

    van Laarhoven, J J E M; Lansink, K W W; van Heijl, M; Lichtveld, R A; Leenen, L P H

    2014-05-01

    For optimal treatment of trauma patients it is of great importance to identify patients who are at risk for severe injuries. The Dutch field triage protocol for trauma patients, the LPA (National Protocol of Ambulance Services), is designed to get the right patient, in the right time, to the right hospital. Purpose of this study was to determine diagnostic accuracy and compliance of this triage protocol. Triage criteria were categorised into physiological condition (P), mechanism of trauma (M) and injury type (I). A retrospective analysis of prospectively collected data of all high-energy trauma patients from 2008 to 2011 in the region Central Netherlands is performed. Diagnostic parameters (sensitivity, specificity, negative predictive value, positive predictive value) of the field triage protocol for selecting severely injured patients were calculated including rates of under- and overtriage. Undertriage was defined as the proportion of severely injured patients (Injury Severity Score (ISS)≥16) who were transported to a level two or three trauma care centre. Overtriage was defined as the proportion of non-severely injured patients (ISSprotocol was 89.1% (95% confidence interval (CI) 84.4-92.6) and 60.5% (95% CI 57.9-63.1), respectively. The overall rate of undertriage was 10.9% (95%CI 7.4-15.7) and the overall rate of overtriage was 39.5% (95%CI 36.9-42.1). These rates were 16.5% and 37.7%, respectively for patients with M+I-P-. Compliance to the triage protocol for patients with M+I-P- was 78.7%. Furthermore, compliance in patients with either a positive I+ or positive P+ was 91.2%. The overall rate of undertriage (10.8%) was mainly influenced by a high rate of undertriage in the group of patients with only a positive mechanism criterion, therefore showing low diagnostic accuracy in selecting severely injured patients. As a consequence these patients with severe injury are undetected using the current triage protocol. As it has been shown that severely injured

  18. High-PSRR High-Order Curvature-Compensated CMOS Bandgap Voltage Reference

    Institute of Scientific and Technical Information of China (English)

    Qianneng Zhou; Yunsong Li; Jinzhao Lin; Hongjuan Li; Yu Pang; Wei Luo

    2015-01-01

    A high⁃PSRR high⁃order curvature⁃compensated CMOS bandgap voltage reference (BGR), which has the performances of high power supply rejection ratio ( PSRR) and low temperature coefficient, is designed in SMIC 0�18 μm CMOS process. Compared to the conventional curvature⁃compensated BGR which adopted a piecewise⁃linear current, the temperature characterize of the proposed BGR is effectively improved by adopting two kinds of current including a piecewise⁃linear current and a current proportional 1�5 party to the absolute temperature T. By adopting a low dropout ( LDO) regulator whose output voltage is the operating supply voltage of the proposed BGR core circuit instead of power supply voltage VDD , the proposed BGR with LDO regulator achieves a well PSRR performance than the BGR without LDO regulator. Simulation results show that the proposed BGR with LDO regulator achieves a temperature coefficient of 2�1 × 10-6/℃ with a 1�8 V power supply voltage and a line regulation of 4�9 μV/V at 27 ℃. The proposed BGR with LDO regulator at 10 Hz, 100 Hz, 1 kHz, 10 kHz and 100 kHz have the PSRR of -106�388, -106�388, -106�38, -105�93 and-88�67 dB respectively.

  19. Comparative analysis of the processing accuracy of high strength metal sheets by AWJ, laser and plasma

    Science.gov (United States)

    Radu, M. C.; Schnakovszky, C.; Herghelegiu, E.; Tampu, N. C.; Zichil, V.

    2016-08-01

    Experimental tests were carried out on two high-strength steel materials (Ramor 400 and Ramor 550). Quantification of the dimensional accuracy was achieved by measuring the deviations from some geometric parameters of part (two lengths and two radii). It was found that in case of Ramor 400 steel, at the jet inlet, the deviations from the part radii are quite small for all the three analysed processes. Instead for the linear dimensions, the deviations are small only in case of laser cutting. At the jet outlet, the deviations raised in small amount compared to those obtained at the jet inlet for both materials as well as for all the three processes. Related to Ramor 550 steel, at the jet inlet the deviations from the part radii are very small in case of AWJ and laser cutting but larger in case of plasma cutting. At the jet outlet, the deviations from the part radii are very small for all processes; in case of linear dimensions, there was obtained very small deviations only in the case of laser processing, the other two processes leading to very large deviations.

  20. Accuracy of Intraocular Lens Power Calculation Formulas for Highly Myopic Eyes

    Science.gov (United States)

    Zhang, Yichi; Liang, Xiao Ying; Liu, Shu; Lee, Jacky W. Y.; Bhaskar, Srinivasan; Lam, Dennis S. C.

    2016-01-01

    Purpose. To evaluate and compare the accuracy of different intraocular lens (IOL) power calculation formulas for eyes with an axial length (AL) greater than 26.00 mm. Methods. This study reviewed 407 eyes of 219 patients with AL longer than 26.0 mm. The refractive prediction errors of IOL power calculation formulas (SRK/T, Haigis, Holladay, Hoffer Q, and Barrett Universal II) using User Group for Laser Interference Biometry (ULIB) constants were evaluated and compared. Results. One hundred seventy-one eyes were enrolled. The Barrett Universal II formula had the lowest mean absolute error (MAE) and SRK/T and Haigis had similar MAE, and the statistical highest MAE were seen with the Holladay and Hoffer Q formulas. The interquartile range of the Barrett Universal II formula was also the lowest among all the formulas. The Barrett Universal II formulas yielded the highest percentage of eyes within ±1.0 D and ±0.5 D of the target refraction in this study (97.24% and 79.56%, resp.). Conclusions. Barrett Universal II formula produced the lowest predictive error and the least variable predictive error compared with the SRK/T, Haigis, Holladay, and Hoffer Q formulas. For high myopic eyes, the Barrett Universal II formula may be a more suitable choice. PMID:27119018

  1. Accuracy of Intraocular Lens Power Calculation Formulas for Highly Myopic Eyes

    Directory of Open Access Journals (Sweden)

    Yichi Zhang

    2016-01-01

    Full Text Available Purpose. To evaluate and compare the accuracy of different intraocular lens (IOL power calculation formulas for eyes with an axial length (AL greater than 26.00 mm. Methods. This study reviewed 407 eyes of 219 patients with AL longer than 26.0 mm. The refractive prediction errors of IOL power calculation formulas (SRK/T, Haigis, Holladay, Hoffer Q, and Barrett Universal II using User Group for Laser Interference Biometry (ULIB constants were evaluated and compared. Results. One hundred seventy-one eyes were enrolled. The Barrett Universal II formula had the lowest mean absolute error (MAE and SRK/T and Haigis had similar MAE, and the statistical highest MAE were seen with the Holladay and Hoffer Q formulas. The interquartile range of the Barrett Universal II formula was also the lowest among all the formulas. The Barrett Universal II formulas yielded the highest percentage of eyes within ±1.0 D and ±0.5 D of the target refraction in this study (97.24% and 79.56%, resp.. Conclusions. Barrett Universal II formula produced the lowest predictive error and the least variable predictive error compared with the SRK/T, Haigis, Holladay, and Hoffer Q formulas. For high myopic eyes, the Barrett Universal II formula may be a more suitable choice.

  2. A high accuracy broadband measurement system for time resolved complex bioimpedance measurements.

    Science.gov (United States)

    Kaufmann, S; Malhotra, A; Ardelt, G; Ryschka, M

    2014-06-01

    Bioimpedance measurements are useful tools in biomedical engineering and life science. Bioimpedance is the electrical impedance of living tissue and can be used in the analysis of various physiological parameters. Bioimpedance is commonly measured by injecting a small well known alternating current via surface electrodes into an object under test and measuring the resultant surface voltages. It is non-invasive, painless and has no known hazards. This work presents a field programmable gate array based high accuracy broadband bioimpedance measurement system for time resolved bioimpedance measurements. The system is able to measure magnitude and phase of complex impedances under test in a frequency range of about 10-500 kHz with excitation currents from 10 µA to 5 mA. The overall measurement uncertainties stay below 1% for the impedance magnitude and below 0.5° for the phase in most measurement ranges. Furthermore, the described system has a sample rate of up to 3840 impedance spectra per second. The performance of the bioimpedance measurement system is demonstrated with a resistor based system calibration and with measurements on biological samples.

  3. GRACE Data-based High Accuracy Global Static Earth's Gravity Field Model

    Directory of Open Access Journals (Sweden)

    CHEN Qiujie

    2016-04-01

    Full Text Available To recover the highly accurate static earth's gravity field by using GRACE satellite data is one of the hot topics in geodesy. Since linearization errors of dynamic approach quickly increase when extending satellite arc length, we established a modified dynamic approach for processing GRACE orbit and range-rate measurements in this paper, which treated orbit observations of the twin GRACE satellites as approximate values for linearization. Using the GRACE data spanning the period Jan. 2003 to Dec. 2010, containing satellite attitudes, orbits, range-rate, and non-conservative forces, we developed two global static gravity field models. One is the unconstrained solution called Tongji-Dyn01s complete to degree and order 180; the other one is the Tongji-Dyn01k model computed by using Kaula constraint. The comparisons between our models and those latest GRACE-only models (including the AIUB-GRACE03, the GGM05S, the ITSG-Grace2014k and the Tongji-GRACE01 published by different international groups, and the external validations with marine gravity anomalies from DTU13 product and height anomalies from GPS/levelling data, were performed in this study. The results demonstrate that the Tongji-Dyn01s has the same accuracy level with those of the latest GRACE-only models, while the Tongji-Dyn01k model is closer to the EIGEN6C2 than the other GRACE-only models as a whole.

  4. High Accuracy Extraction of Respiratory Sinus Arrhythmia with Statistical Processing using Normal Distribution

    Science.gov (United States)

    Numata, Takashi; Ogawa, Yutaro; Yoshida, Lui; Kotani, Kiyoshi; Jimbo, Yasuhiko

    The autonomic nervous system is important in maintaining homeostasis by mediating the opposing effects of the sympathetic and parasympathetic nervous activity on organs. Although it is known that the amplitude of RSA (Respiratory Sinus Arrhythmia) is an index of parasympathetic nervous activity, it is difficult to estimate that activity in real-time in everyday situations. It is partly caused by body motions and extrasystoles. Also, automatic recognition of the R-wave on electrocardiograms is required for real-time analysis of RSA amplitude, there is an unresolved problem of false recognition of the R-wave. In this paper, we propose a method to evaluate the amplitude of RSA accurately using statistical processing with probabilistic models. Then, we estimate parasympathetic nervous activity during body motion and isometric exercise to examine the validity of the method. As a result, using the proposed method, we demonstrate that the amplitude of RSA can be extracted with false recognition of the R-wave. In addition, an appropriate threshold for the estimate is one or five percent because waveforms of RSA amplitude do not follow the abrupt changes of the parasympathetic nervous activity evoked by isometric exercise with the threshold at ten percent. Furthermore, the method using normal distribution is found to be more appropriate than that of chi-square distribution for statistical processing. Therefore, we expect that the proposed method can evaluate parasympathetic nervous activity with high accuracy in everyday situations.

  5. Raman spectroscopic determination of the molecular constants of the hydrogen isotopologues with high accuracy

    Energy Technology Data Exchange (ETDEWEB)

    Krasch, Bennet; Mirz, Sebastian; Groessle, Robin [Karlsruhe Institute of Technology KIT (Germany). Institute for Technical Physics (ITEP), Tritium Laboratory Karlsruhe (TLK); Collaboration: KATRIN-Collaboration

    2016-07-01

    The interest in the thermodynamic properties of gases as the chemical equilibrium is faced by the challenge of time-consuming and technical extensive experimental setups. One possible solution is the derivation of these properties from the molecular constants. The rotational and vibrational movement of diatomic molecules, as the hydrogen isotopologues, is described by the concept of the rotational anharmonic oscillator. The molecular constants are the free parameters of this concept. Molecular constants themselves can be determined by measuring the line position of rotational and/or rotational transitions e.g. with Raman spectroscopy for hydrogen as it has been done since several years. In this contribution a Raman method was development to measure the molecular constant of the hydrogen isotopologues with high accuracy to obtain reliable results. But not only the method was development but also a complete measurement uncertainty budget was set up. The uncertainty budget contains all possible sources for uncertainties from the measurement period or the analysis process as well the contribution of each single uncertainty. The method and the uncertainty budget were exemplary tested on Deuterium.

  6. Fast-type high-accuracy universal polarimeter using charge-coupled device spectrometer

    Directory of Open Access Journals (Sweden)

    Akifumi Takanabe

    2017-02-01

    Full Text Available A fast, high-accuracy universal polarimeter was developed using a charge-coupled device (CCD spectrometer (CCD-HAUP, to carry out simultaneous optical anisotropic (linear birefringence, LB; linear dichroism, LD and chiroptical (circular birefringence, CB; circular dichroism, CD measurements on single crystals without any pretreatment, in the visible region between 400–680 nm. The principle of the HAUP method is to measure the intensities of emergent light passing through a polarizer, a crystal sample, and then an analyzer, as the azimuth angles of the polarizer and analyzer are independently altered. The CCD-HAUP has the unique feature that white transmitted light intensity can be measured using a CCD spectrometer, compared with the generalized HAUP (G-HAUP system in which monochromatic transmitted light is measured using a photomultiplier. The CCD-HAUP measurements across the entire wavelength region are completed within the G-HAUP measurement time for a single wavelength. The CCD-HAUP drastically reduces the measurement time for a dataset to only 1.5 h, from the 24 h required for the G-HAUP system. LB, LD, CB, and CD measurements of single crystals of α-quartz and enantiomeric photomechanical salicylidenephenylethylamines before, during, and after ultraviolet light irradiation show results comparable to those obtained using the G-HAUP system. The newly developed system is very effective for samples susceptible to degradation induced by external stimuli, such as light and heat.

  7. Statistical downscaling of precipitation using local regression and high accuracy surface modeling method

    Science.gov (United States)

    Zhao, Na; Yue, Tianxiang; Zhou, Xun; Zhao, Mingwei; Liu, Yu; Du, Zhengping; Zhang, Lili

    2017-07-01

    Downscaling precipitation is required in local scale climate impact studies. In this paper, a statistical downscaling scheme was presented with a combination of geographically weighted regression (GWR) model and a recently developed method, high accuracy surface modeling method (HASM). This proposed method was compared with another downscaling method using the Coupled Model Intercomparison Project Phase 5 (CMIP5) database and ground-based data from 732 stations across China for the period 1976-2005. The residual which was produced by GWR was modified by comparing different interpolators including HASM, Kriging, inverse distance weighted method (IDW), and Spline. The spatial downscaling from 1° to 1-km grids for period 1976-2005 and future scenarios was achieved by using the proposed downscaling method. The prediction accuracy was assessed at two separate validation sites throughout China and Jiangxi Province on both annual and seasonal scales, with the root mean square error (RMSE), mean relative error (MRE), and mean absolute error (MAE). The results indicate that the developed model in this study outperforms the method that builds transfer function using the gauge values. There is a large improvement in the results when using a residual correction with meteorological station observations. In comparison with other three classical interpolators, HASM shows better performance in modifying the residual produced by local regression method. The success of the developed technique lies in the effective use of the datasets and the modification process of the residual by using HASM. The results from the future climate scenarios show that precipitation exhibits overall increasing trend from T1 (2011-2040) to T2 (2041-2070) and T2 to T3 (2071-2100) in RCP2.6, RCP4.5, and RCP8.5 emission scenarios. The most significant increase occurs in RCP8.5 from T2 to T3, while the lowest increase is found in RCP2.6 from T2 to T3, increased by 47.11 and 2.12 mm, respectively.

  8. Statistical downscaling of precipitation using local regression and high accuracy surface modeling method

    Science.gov (United States)

    Zhao, Na; Yue, Tianxiang; Zhou, Xun; Zhao, Mingwei; Liu, Yu; Du, Zhengping; Zhang, Lili

    2016-03-01

    Downscaling precipitation is required in local scale climate impact studies. In this paper, a statistical downscaling scheme was presented with a combination of geographically weighted regression (GWR) model and a recently developed method, high accuracy surface modeling method (HASM). This proposed method was compared with another downscaling method using the Coupled Model Intercomparison Project Phase 5 (CMIP5) database and ground-based data from 732 stations across China for the period 1976-2005. The residual which was produced by GWR was modified by comparing different interpolators including HASM, Kriging, inverse distance weighted method (IDW), and Spline. The spatial downscaling from 1° to 1-km grids for period 1976-2005 and future scenarios was achieved by using the proposed downscaling method. The prediction accuracy was assessed at two separate validation sites throughout China and Jiangxi Province on both annual and seasonal scales, with the root mean square error (RMSE), mean relative error (MRE), and mean absolute error (MAE). The results indicate that the developed model in this study outperforms the method that builds transfer function using the gauge values. There is a large improvement in the results when using a residual correction with meteorological station observations. In comparison with other three classical interpolators, HASM shows better performance in modifying the residual produced by local regression method. The success of the developed technique lies in the effective use of the datasets and the modification process of the residual by using HASM. The results from the future climate scenarios show that precipitation exhibits overall increasing trend from T1 (2011-2040) to T2 (2041-2070) and T2 to T3 (2071-2100) in RCP2.6, RCP4.5, and RCP8.5 emission scenarios. The most significant increase occurs in RCP8.5 from T2 to T3, while the lowest increase is found in RCP2.6 from T2 to T3, increased by 47.11 and 2.12 mm, respectively.

  9. Optimal Cutoff and Accuracy of an IgM Enzyme-Linked Immunosorbent Assay for Diagnosis of Acute Scrub Typhus in Northern Thailand: an Alternative Reference Method to the IgM Immunofluorescence Assay

    Science.gov (United States)

    Blacksell, Stuart D.; Tanganuchitcharnchai, Ampai; Jintaworn, Suthatip; Kantipong, Pacharee; Richards, Allen L.; Day, Nicholas P. J.

    2016-01-01

    The enzyme-linked immunosorbent assay (ELISA) has been proposed as an alternative serologic diagnostic test to the indirect immunofluorescence assay (IFA) for scrub typhus. Here, we systematically determine the optimal sample dilution and cutoff optical density (OD) and estimate the accuracy of IgM ELISA using Bayesian latent class models (LCMs). Data from 135 patients with undifferentiated fever were reevaluated using Bayesian LCMs. Every patient was evaluated for the presence of an eschar and tested with a blood culture for Orientia tsutsugamushi, three different PCR assays, and an IgM IFA. The IgM ELISA was performed for every sample at sample dilutions from 1:100 to 1:102,400 using crude whole-cell antigens of the Karp, Kato, and Gilliam strains of O. tsutsugamushi developed by the Naval Medical Research Center. We used Bayesian LCMs to generate unbiased receiver operating characteristic curves and found that the sample dilution of 1:400 was optimal for the IgM ELISA. With the optimal cutoff OD of 1.474 at a sample dilution of 1:400, the IgM ELISA had a sensitivity of 85.7% (95% credible interval [CrI], 77.4% to 86.7%) and a specificity of 98.1% (95% CrI, 97.2% to 100%) using paired samples. For the ELISA, the OD could be determined objectively and quickly, in contrast to the reading of IFA slides, which was both subjective and labor-intensive. The IgM ELISA for scrub typhus has high diagnostic accuracy and is less subjective than the IgM IFA. We suggest that the IgM ELISA may be used as an alternative reference test to the IgM IFA for the serological diagnosis of scrub typhus. PMID:27008880

  10. Optimal Cutoff and Accuracy of an IgM Enzyme-Linked Immunosorbent Assay for Diagnosis of Acute Scrub Typhus in Northern Thailand: an Alternative Reference Method to the IgM Immunofluorescence Assay.

    Science.gov (United States)

    Blacksell, Stuart D; Lim, Cherry; Tanganuchitcharnchai, Ampai; Jintaworn, Suthatip; Kantipong, Pacharee; Richards, Allen L; Paris, Daniel H; Limmathurotsakul, Direk; Day, Nicholas P J

    2016-06-01

    The enzyme-linked immunosorbent assay (ELISA) has been proposed as an alternative serologic diagnostic test to the indirect immunofluorescence assay (IFA) for scrub typhus. Here, we systematically determine the optimal sample dilution and cutoff optical density (OD) and estimate the accuracy of IgM ELISA using Bayesian latent class models (LCMs). Data from 135 patients with undifferentiated fever were reevaluated using Bayesian LCMs. Every patient was evaluated for the presence of an eschar and tested with a blood culture for Orientia tsutsugamushi, three different PCR assays, and an IgM IFA. The IgM ELISA was performed for every sample at sample dilutions from 1:100 to 1:102,400 using crude whole-cell antigens of the Karp, Kato, and Gilliam strains of O. tsutsugamushi developed by the Naval Medical Research Center. We used Bayesian LCMs to generate unbiased receiver operating characteristic curves and found that the sample dilution of 1:400 was optimal for the IgM ELISA. With the optimal cutoff OD of 1.474 at a sample dilution of 1:400, the IgM ELISA had a sensitivity of 85.7% (95% credible interval [CrI], 77.4% to 86.7%) and a specificity of 98.1% (95% CrI, 97.2% to 100%) using paired samples. For the ELISA, the OD could be determined objectively and quickly, in contrast to the reading of IFA slides, which was both subjective and labor-intensive. The IgM ELISA for scrub typhus has high diagnostic accuracy and is less subjective than the IgM IFA. We suggest that the IgM ELISA may be used as an alternative reference test to the IgM IFA for the serological diagnosis of scrub typhus.

  11. High-accuracy 2D digital image correlation measurements using low-cost imaging lenses: implementation of a generalized compensation method

    Science.gov (United States)

    Pan, Bing; Yu, Liping; Wu, Dafang

    2014-02-01

    The ideal pinhole imaging model commonly assumed for an ordinary two-dimensional digital image correlation (2D-DIC) system is neither perfect nor stable because of the existence of small out-of-plane motion of the test sample surface that occurred after loading, small out-of-plane motion of the sensor target due to temperature variation of a camera and unavoidable geometric distortion of an imaging lens. In certain cases, these disadvantages can lead to significant errors in the measured displacements and strains. Although a high-quality bilateral telecentric lens has been strongly recommended to be used in the 2D-DIC system as an essential optical component to achieve high-accuracy measurement, it is not generally applicable due to its fixed field of view, limited depth of focus and high cost. To minimize the errors associated with the imperfectness and instability of a common 2D-DIC system using a low-cost imaging lens, a generalized compensation method using a non-deformable reference sample is proposed in this work. With the proposed method, the displacement of the reference sample rigidly attached behind the test sample is first measured using 2D-DIC, and then it is fitted using a parametric model. The fitted parametric model is then used to correct the displacements of the deformed sample to remove the influences of these unfavorable factors. The validity of the proposed compensation method is first verified using out-of-plane translation, out-of-plane rotation, in-plane translation tests and their combinations. Uniaxial tensile tests of an aluminum specimen were also performed to quantitatively examine the strain accuracy of the proposed compensation method. Experiments show that the proposed compensation method is an easy-to-implement yet effective technique for achieving high-accuracy deformation measurement using an ordinary 2D-DIC system.

  12. Results of the LIRES Round Robin test on high temperature reference electrodes for LWR applications

    Energy Technology Data Exchange (ETDEWEB)

    Bosch, R.W. [SCK.CEN, Nuclear Research Centre Belgium, Boeretang 200, B-2400 Mol (Belgium); Nagy, G. [Magyar Tudomanyos Akademia KFKI Atomenergia Kutatointezet, AEKI, Konkoly Thege ut 29-33, 1121 Budapest (Hungary); Feron, D. [CEA Saclay, 91191 Gif-Sur-Yvette Cedex (France); Navas, M. [CIEMAT, Edificio 30, Dpto. Fision Nuclear, Avda. Complutense 22, 28040 Madrid, (Spain); Bogaerts, W. [KU Leuven, Kasteelpark Arenberg 31, B-3001 Leuven (Belgium); Karnik, D. [Nuclear Research Institute, NRI, Rez (Czech Republic); Dorsch, T. [Framatone ANP, Inc., Charlotte, North Carolina (United States); Molander, A. [Studsvik AB SE-611 82 Nykoeping (Sweden); Maekelae, K. [Materials and Structural Integrity, VTT Technical Research Centre of Finland, Kemistintie 3, P.O. Box 1704, FIN-02044 VTT (Finland)

    2004-07-01

    A European sponsored research project has been started on 1 October 2000 to develop high temperature reference electrodes that can be used for in-core electrochemical measurements in Light Water Reactors (LWR's). This LIRES-project (Development of Light Water Reactor Reference Electrodes) consists of 9 partners (SCK-CEN, AEKI, CEA, CIEMAT, KU Leuven, NRI Rez, Framatone ANP, Studsvik Nuclear and VTT) and will last for four years. The main objective of this LIRES project is to develop a reference electrode, which is robust enough to be used inside a LWR. Emphasize is put on the radiation hardness of both the mechanical design of the electrode as the proper functioning of the electrode. A four steps development trajectory is foreseen: (1) To set a testing standard for a Round Robin, (2) To develop different reference electrodes, (3) To perform a Round Robin test of these reference electrodes followed by selection of the best reference electrode(s), (4) To perform irradiation tests under appropriate LWR conditions in a Material Test Reactor (MTR). Four different high temperature reference electrodes have been developed and are being tested in a Round Robin test. These electrodes are: A Ceramic Membrane Electrode (CME), a Rhodium electrode, an external Ag/AgCl electrode and a Palladium electrode. The presentation will focus on the results obtained with the Round Robin test. (authors)

  13. Geometric Accuracy Investigations of SEVIRI High Resolution Visible (HRV) Level 1.5 Imagery

    National Research Council Canada - National Science Library

    Sultan Kocaman Aksakal

    2013-01-01

    .... In a joint project between the Swiss GCOS Office and ETH Zurich, geometric accuracy and temporal stability of 1-km resolution HRV channel imagery of SEVIRI have been evaluated over Switzerland...

  14. The regulatory benefits of high levels of affect perception accuracy: a process analysis of reactions to stressors in daily life.

    Science.gov (United States)

    Robinson, Michael D; Moeller, Sara K; Buchholz, Maria M; Boyd, Ryan L; Troop-Gordon, Wendy

    2012-08-01

    Individuals attuned to affective signals from the environment may possess an advantage in the emotion-regulation realm. In two studies (total n = 151), individual differences in affective perception accuracy were assessed in an objective, performance-based manner. Subsequently, the same individuals completed daily diary protocols in which daily stressor levels were reported as well as problematic states shown to be stress-reactive in previous studies. In both studies, individual differences in affect perception accuracy interacted with daily stressor levels to predict the problematic outcomes. Daily stressors precipitated problematic reactions--whether depressive feelings (study 1) or somatic symptoms (study 2)--at low levels of affect perception accuracy, but did not do so at high levels of affect perception accuracy. The findings support a regulatory view of such perceptual abilities. Implications for understanding emotion regulation processes, emotional intelligence, and individual differences in reactivity are discussed.

  15. [Accuracy of liquid-based cytology in diagnosis of high-grade squamous cervical intraepithelial neoplasia].

    Science.gov (United States)

    Li, Min; Mei, Ping; Luo, Dong-lan; Wang, Xiao-bing; Liu, Yan-hui

    2012-04-01

    To investigate factors affecting the diagnostic accuracy of cervical liquid-based cytology for high-grade squamous intraepithelial lesion (HSIL). A retrospective evaluation of cytological and histological slides was performed in 415 patients who had cytological HSIL between 2007 and 2010. Among 42 209 cases screened by ThinPrep liquid-based cytology, 415 cases (1.0%) of HSIL were eventually identified. The mean age of HSIL patients was 41.6 years, and 30-49 years were the most common age group. Among 415 cases, 325 patients had available histological diagnosis as follows: 23 (7.1%) negative, 22 (6.8%) CIN1/HPV, 223 (68.6%) CIN2/CIN3, and 57 (17.5%) squamous cell carcinoma (SCC). The positive predictive values of HSIL to predict CIN2 (or higher grade of dysplasia) and CIN1 were 86.2% (280/325) and 92.9% (302/325), respectively. Inadequate biopsy, reactive glandular cells, islet atrophy, chemo/radiotherapy and others were responsible for the cytologically false-positive diagnosis. Fifty-seven (17.5%) cases of HSIL had a histological diagnosis of SCC. The possible causes of misdiagnosis were social factors, under-recognized cytological features of poorly-differentiated SCC and absence of typical diagnostic features in cytology slides. Cytology of HSIL has a high positive predictive value for the presence of CIN2/CIN3 and SCC. Cytologists and gynecologists should be aware of the diagnostic pitfalls that may lead to the discrepancy between cytology and histology.

  16. Achieving numerical accuracy and high performance using recursive tile LU factorization with partial pivoting

    KAUST Repository

    Dongarra, Jack

    2013-09-18

    The LU factorization is an important numerical algorithm for solving systems of linear equations in science and engineering and is a characteristic of many dense linear algebra computations. For example, it has become the de facto numerical algorithm implemented within the LINPACK benchmark to rank the most powerful supercomputers in the world, collected by the TOP500 website. Multicore processors continue to present challenges to the development of fast and robust numerical software due to the increasing levels of hardware parallelism and widening gap between core and memory speeds. In this context, the difficulty in developing new algorithms for the scientific community resides in the combination of two goals: achieving high performance while maintaining the accuracy of the numerical algorithm. This paper proposes a new approach for computing the LU factorization in parallel on multicore architectures, which not only improves the overall performance but also sustains the numerical quality of the standard LU factorization algorithm with partial pivoting. While the update of the trailing submatrix is computationally intensive and highly parallel, the inherently problematic portion of the LU factorization is the panel factorization due to its memory-bound characteristic as well as the atomicity of selecting the appropriate pivots. Our approach uses a parallel fine-grained recursive formulation of the panel factorization step and implements the update of the trailing submatrix with the tile algorithm. Based on conflict-free partitioning of the data and lockless synchronization mechanisms, our implementation lets the overall computation flow naturally without contention. The dynamic runtime system called QUARK is then able to schedule tasks with heterogeneous granularities and to transparently introduce algorithmic lookahead. The performance results of our implementation are competitive compared to the currently available software packages and libraries. For example

  17. Direct Georeferencing : a New Standard in Photogrammetry for High Accuracy Mapping

    Science.gov (United States)

    Rizaldy, A.; Firdaus, W.

    2012-07-01

    Direct georeferencing is a new method in photogrammetry, especially in the digital camera era. Theoretically, this method does not require ground control points (GCP) and the Aerial Triangulation (AT), to process aerial photography into ground coordinates. Compared with the old method, this method has three main advantages: faster data processing, simple workflow and less expensive project, at the same accuracy. Direct georeferencing using two devices, GPS and IMU. GPS recording the camera coordinates (X, Y, Z), and IMU recording the camera orientation (omega, phi, kappa). Both parameters merged into Exterior Orientation (EO) parameter. This parameters required for next steps in the photogrammetric projects, such as stereocompilation, DSM generation, orthorectification and mosaic. Accuracy of this method was tested on topographic map project in Medan, Indonesia. Large-format digital camera Ultracam X from Vexcel is used, while the GPS / IMU is IGI AeroControl. 19 Independent Check Point (ICP) were used to determine the accuracy. Horizontal accuracy is 0.356 meters and vertical accuracy is 0.483 meters. Data with this accuracy can be used for 1:2.500 map scale project.

  18. HIGH ACCURACY FINITE VOLUME ELEMENT METHOD FOR TWO-POINT BOUNDARY VALUE PROBLEM OF SECOND ORDER ORDINARY DIFFERENTIAL EQUATIONS

    Institute of Scientific and Technical Information of China (English)

    王同科

    2002-01-01

    In this paper, a high accuracy finite volume element method is presented for two-point boundary value problem of second order ordinary differential equation, which differs fromthe high order generalized difference methods. It is proved that the method has optimal order er-ror estimate O(h3) in H1 norm. Finally, two examples show that the method is effective.

  19. Numerical simulation for accuracy of velocity analysis in small-scale high-resolution marine multichannel seismic technology

    Science.gov (United States)

    Luo, Di; Cai, Feng; Wu, Zhiqiang

    2017-06-01

    When used with large energy sparkers, marine multichannel small-scale high-resolution seismic detection technology has a high resolution, high-detection precision, a wide applicable range, and is very flexible. Positive results have been achieved in submarine geological research, particularly in the investigation of marine gas hydrates. However, the amount of traveltime difference information is reduced for the velocity analysis under conditions of a shorter spread length, thus leading to poorer focusing of the velocity spectrum energy group and a lower accuracy of the velocity analysis. It is thus currently debatable whether the velocity analysis accuracy of short-arrangement multichannel seismic detection technology is able to meet the requirements of practical application in natural gas hydrate exploration. Therefore, in this study the bottom boundary of gas hydrates (Bottom Simulating Reflector, BSR) is used to conduct numerical simulation to discuss the accuracy of the velocity analysis related to such technology. Results show that a higher dominant frequency and smaller sampling interval are not only able to improve the seismic resolution, but they also compensate for the defects of the short-arrangement, thereby improving the accuracy of the velocity analysis. In conclusion, the accuracy of the velocity analysis in this small-scale, high-resolution, multi-channel seismic detection technology meets the requirements of natural gas hydrate exploration.

  20. Towards Building Reliable, High-Accuracy Solar Irradiance Database For Arid Climates

    Science.gov (United States)

    Munawwar, S.; Ghedira, H.

    2012-12-01

    Middle East's growing interest in renewable energy has led to increased activity in solar technology development with the recent commissioning of several utility-scale solar power projects and many other commercial installations across the Arabian Peninsula. The region, lying in a virtually rainless sunny belt with a typical daily average solar radiation exceeding 6 kWh/m2, is also one of the most promising candidates for solar energy deployment. However, it is not the availability of resource, but its characterization and reasonably accurate assessment that determines the application potential. Solar irradiance, magnitude and variability inclusive, is the key input in assessing the economic feasibility of a solar system. The accuracy of such data is of critical importance for realistic on-site performance estimates. This contribution aims to identify the key stages in developing a robust solar database for desert climate by focusing on the challenges that an arid environment presents to parameterization of solar irradiance attenuating factors. Adjustments are proposed based on the currently available resource assessment tools to produce high quality data for assessing bankability. Establishing and maintaining ground solar irradiance measurements is an expensive affair and fairly limited in time (recently operational) and space (fewer sites) in the Gulf region. Developers within solar technology industry, therefore, rely on solar radiation models and satellite-derived data for prompt resource assessment needs. It is imperative that such estimation tools are as accurate as possible. While purely empirical models have been widely researched and validated in the Arabian Peninsula's solar modeling history, they are known to be intrinsically site-specific. A primal step to modeling is an in-depth understanding of the region's climate, identifying the key players attenuating radiation and their appropriate characterization to determine solar irradiance. Physical approach

  1. Finite-element solution of the coupled-channel Schrödinger equation using high-order accuracy approximations

    Science.gov (United States)

    Abrashkevich, A. G.; Abrashkevich, D. G.; Kaschiev, M. S.; Puzynin, I. V.

    1995-01-01

    The finite element method (FEM) is applied to solve the bound state (Sturm-Liouville) problem for systems of ordinary linear second-order differential equations. The convergence, accuracy and the range of applicability of the high-order FEM approximations (up to tenth order) are studied systematically on the basis of numerical experiments for a wide set of quantum-mechanical problems. The analytical and tabular forms of giving the coefficients of differential equations are considered. The Dirichlet and Neumann boundary conditions are discussed. It is shown that the use of the FEM high-order accuracy approximations considerably increases the accuracy of the FE solutions with substantial reduction of the requirements on the computational resources. The results of the FEM calculations for various quantum-mechanical problems dealing with different types of potentials used in atomic and molecular calculations (including the hydrogen atom in a homogeneous magnetic field) are shown to be well converged and highly accurate.

  2. Automated, high accuracy classification of Parkinsonian disorders: a pattern recognition approach.

    Directory of Open Access Journals (Sweden)

    Andre F Marquand

    Full Text Available Progressive supranuclear palsy (PSP, multiple system atrophy (MSA and idiopathic Parkinson's disease (IPD can be clinically indistinguishable, especially in the early stages, despite distinct patterns of molecular pathology. Structural neuroimaging holds promise for providing objective biomarkers for discriminating these diseases at the single subject level but all studies to date have reported incomplete separation of disease groups. In this study, we employed multi-class pattern recognition to assess the value of anatomical patterns derived from a widely available structural neuroimaging sequence for automated classification of these disorders. To achieve this, 17 patients with PSP, 14 with IPD and 19 with MSA were scanned using structural MRI along with 19 healthy controls (HCs. An advanced probabilistic pattern recognition approach was employed to evaluate the diagnostic value of several pre-defined anatomical patterns for discriminating the disorders, including: (i a subcortical motor network; (ii each of its component regions and (iii the whole brain. All disease groups could be discriminated simultaneously with high accuracy using the subcortical motor network. The region providing the most accurate predictions overall was the midbrain/brainstem, which discriminated all disease groups from one another and from HCs. The subcortical network also produced more accurate predictions than the whole brain and all of its constituent regions. PSP was accurately predicted from the midbrain/brainstem, cerebellum and all basal ganglia compartments; MSA from the midbrain/brainstem and cerebellum and IPD from the midbrain/brainstem only. This study demonstrates that automated analysis of structural MRI can accurately predict diagnosis in individual patients with Parkinsonian disorders, and identifies distinct patterns of regional atrophy particularly useful for this process.

  3. Functional knowledge transfer for high-accuracy prediction of under-studied biological processes.

    Directory of Open Access Journals (Sweden)

    Christopher Y Park

    Full Text Available A key challenge in genetics is identifying the functional roles of genes in pathways. Numerous functional genomics techniques (e.g. machine learning that predict protein function have been developed to address this question. These methods generally build from existing annotations of genes to pathways and thus are often unable to identify additional genes participating in processes that are not already well studied. Many of these processes are well studied in some organism, but not necessarily in an investigator's organism of interest. Sequence-based search methods (e.g. BLAST have been used to transfer such annotation information between organisms. We demonstrate that functional genomics can complement traditional sequence similarity to improve the transfer of gene annotations between organisms. Our method transfers annotations only when functionally appropriate as determined by genomic data and can be used with any prediction algorithm to combine transferred gene function knowledge with organism-specific high-throughput data to enable accurate function prediction. We show that diverse state-of-art machine learning algorithms leveraging functional knowledge transfer (FKT dramatically improve their accuracy in predicting gene-pathway membership, particularly for processes with little experimental knowledge in an organism. We also show that our method compares favorably to annotation transfer by sequence similarity. Next, we deploy FKT with state-of-the-art SVM classifier to predict novel genes to 11,000 biological processes across six diverse organisms and expand the coverage of accurate function predictions to processes that are often ignored because of a dearth of annotated genes in an organism. Finally, we perform in vivo experimental investigation in Danio rerio and confirm the regulatory role of our top predicted novel gene, wnt5b, in leftward cell migration during heart development. FKT is immediately applicable to many bioinformatics

  4. Autotaxin activity has a high accuracy to diagnose intrahepatic cholestasis of pregnancy.

    Science.gov (United States)

    Kremer, Andreas E; Bolier, Ruth; Dixon, Peter H; Geenes, Victoria; Chambers, Jenny; Tolenaars, Dagmar; Ris-Stalpers, Carrie; Kaess, Bernhard M; Rust, Christian; van der Post, Joris A; Williamson, Catherine; Beuers, Ulrich; Oude Elferink, Ronald P J

    2015-04-01

    Intrahepatic cholestasis of pregnancy (ICP) is defined by pruritus, elevated total fasting serum bile salts (TBS) and transaminases, and an increased risk of adverse fetal outcome. An accurate diagnostic marker is needed. Increased serum autotaxin correlates with cholestasis-associated pruritus. We aimed at unraveling the diagnostic accuracy of autotaxin in ICP. Serum samples and placental tissue were collected from 44 women with uncomplicated pregnancies and 105 with pruritus and/or elevated serum transaminases. Autotaxin serum levels were quantified enzymatically and by Western blotting, autotaxin gene expression by quantitative PCR. Serum autotaxin was increased in ICP (mean ± SD: 43.5 ± 18.2 nmol ml(-1)min(-1), n=55, ppregnancy (16.8 ± 6.7 nmol ml(-1)min(-1), n=33), pre-eclampsia complicated by HELLP-syndrome (16.8 ± 8.9 nmol ml(-1)min(-1), n=17), and pregnant controls (19.6 ± 5.7 nmol ml(-1)min(-1), n=44). Longitudinal analysis during pregnancy revealed a marked rise in serum autotaxin with onset of ICP-related pruritus. Serum autotaxin was increased in women taking oral contraceptives. Increased serum autotaxin during ICP was not associated with increased autotaxin mRNA in placenta. With a cut-off value of 27.0 nmol ml(-1)min(-1), autotaxin had an excellent sensitivity and specificity in distinguishing ICP from other pruritic disorders or pre-eclampsia/HELLP-syndrome. Serum autotaxin displayed no circadian rhythm and was not influenced by food intake. Increased serum autotaxin activity represents a highly sensitive, specific and robust diagnostic marker of ICP, distinguishing ICP from other pruritic disorders of pregnancy and pregnancy-related liver diseases. Pregnancy and oral contraception increase serum autotaxin to a much lesser extent than ICP. Copyright © 2014 European Association for the Study of the Liver. Published by Elsevier B.V. All rights reserved.

  5. High accuracy solution of bi-directional wave propagation in continuum mechanics

    Science.gov (United States)

    Mulloth, Akhil; Sawant, Nilesh; Haider, Ijlal; Sharma, Nidhi; Sengupta, Tapan K.

    2015-10-01

    Solution of partial differential equations by numerical method is strongly affected due to numerical errors, which are caused mainly by deviation of numerical dispersion relation from the physical dispersion relation. To quantify and control such errors and obtain high accuracy solutions, we consider a class of problems which involve second derivative of unknowns with respect to time. Here, we analyse numerical metrics such as the numerical group velocity, numerical phase speed and the numerical amplification factor for different methods in solving the model bi-directional wave equation (BDWE). Such equations can be solved directly, for example, by Runge-Kutta-Nyström (RKN) method. Alternatively, the governing equation can be converted to a set of first order in time equations and then using four-stage fourth order Runge-Kutta (RK4) method for time integration. Spatial discretisation considered are the classical second and fourth order central difference schemes, along with Lele's central compact scheme for evaluating second derivatives. In another version, we have used Lele's scheme for evaluating first derivatives twice to obtain the second derivative. As BDWE represents non-dissipative, non-dispersive dynamics, we also consider the canonical problem of linearised rotating shallow water equation (LRSWE) in a new formulation involving second order derivative in time, which represents dispersive waves along with a stationary mode. The computations of LRSWE with RK4 and RKN methods for temporal discretisation and Lele's compact schemes for spatial discretisation are compared with computations performed with RK4 method for time discretisation and staggered compact scheme (SCS) for spatial discretisation by treating it as a set of three equations as reported in Rajpoot et al. (2012) [1].

  6. In-depth, high-accuracy proteomics of sea urchin tooth organic matrix

    Directory of Open Access Journals (Sweden)

    Mann Matthias

    2008-12-01

    Full Text Available Abstract Background The organic matrix contained in biominerals plays an important role in regulating mineralization and in determining biomineral properties. However, most components of biomineral matrices remain unknown at present. In sea urchin tooth, which is an important model for developmental biology and biomineralization, only few matrix components have been identified. The recent publication of the Strongylocentrotus purpuratus genome sequence rendered possible not only the identification of genes potentially coding for matrix proteins, but also the direct identification of proteins contained in matrices of skeletal elements by in-depth, high-accuracy proteomic analysis. Results We identified 138 proteins in the matrix of tooth powder. Only 56 of these proteins were previously identified in the matrices of test (shell and spine. Among the novel components was an interesting group of five proteins containing alanine- and proline-rich neutral or basic motifs separated by acidic glycine-rich motifs. In addition, four of the five proteins contained either one or two predicted Kazal protease inhibitor domains. The major components of tooth matrix were however largely identical to the set of spicule matrix proteins and MSP130-related proteins identified in test (shell and spine matrix. Comparison of the matrices of crushed teeth to intact teeth revealed a marked dilution of known intracrystalline matrix proteins and a concomitant increase in some intracellular proteins. Conclusion This report presents the most comprehensive list of sea urchin tooth matrix proteins available at present. The complex mixture of proteins identified may reflect many different aspects of the mineralization process. A comparison between intact tooth matrix, presumably containing odontoblast remnants, and crushed tooth matrix served to differentiate between matrix components and possible contributions of cellular remnants. Because LC-MS/MS-based methods directly

  7. High accuracy of arterial spin labeling perfusion imaging in differentiation of pilomyxoid from pilocytic astrocytoma

    Energy Technology Data Exchange (ETDEWEB)

    Nabavizadeh, S.A.; Assadsangabi, R.; Hajmomenian, M.; Vossough, A. [Perelman School of Medicine of the University of Pennsylvania, Department of Radiology, Children' s Hospital of Philadelphia, Philadelphia, PA (United States); Santi, M. [Perelman School of Medicine of the University of Pennsylvania, Department of Pathology, Children' s Hospital of Philadelphia, Philadelphia, PA (United States)

    2015-05-01

    Pilomyxoid astrocytoma (PMA) is a relatively new tumor entity which has been added to the 2007 WHO Classification of tumors of the central nervous system. The goal of this study is to utilize arterial spin labeling (ASL) perfusion imaging to differentiate PMA from pilocytic astrocytoma (PA). Pulsed ASL and conventional MRI sequences of patients with PMA and PA in the past 5 years were retrospectively evaluated. Patients with history of radiation or treatment with anti-angiogenic drugs were excluded. A total of 24 patients (9 PMA, 15 PA) were included. There were statistically significant differences between PMA and PA in mean tumor/gray matter (GM) cerebral blood flow (CBF) ratios (1.3 vs 0.4, p < 0.001) and maximum tumor/GM CBF ratio (2.3 vs 1, p < 0.001). Area under the receiver operating characteristic (ROC) curves for differentiation of PMA from PA was 0.91 using mean tumor CBF, 0.95 using mean tumor/GM CBF ratios, and 0.89 using maximum tumor/GM CBF. Using a threshold value of 0.91, the mean tumor/GM CBF ratio was able to diagnose PMA with 77 % sensitivity, 100 % specificity, and a threshold value of 0.7, provided 88 % sensitivity and 86 % specificity. There was no statistically significant difference between the two tumors in enhancement pattern (p = 0.33), internal architecture (p = 0.15), or apparent diffusion coefficient (ADC) values (p = 0.07). ASL imaging has high accuracy in differentiating PMA from PA. The result of this study may have important applications in prognostication and treatment planning especially in patients with less accessible tumors such as hypothalamic-chiasmatic gliomas. (orig.)

  8. High Resolution Ice Surface of the Ross Ice Shelf: Accuracy and Links to Basal Processes

    Science.gov (United States)

    Starke, S. E.

    2015-12-01

    We use airborne laser altimetry data from IcePod and IceBridge to map the surface across the Ross Ice Shelf in Antarctica. Laser altimetry and radar data is analyzed from the IcePod 2014 and 2015 field campaigns as well as IceBridge 2013. Icepod is a multi sensor suite that includes ice penetrating radars, a swath scanning laser, visible and IR cameras as well as GPS mounted on a LC-130. Using shallow ice radar data from both IcePod and IceBridge we identify the base of the ice shelf. Across the shelf we observe distinct areas of high reflectivity in the radar data suggesting basal crevassing. In some regions, the basal reflector is not well defined. Laser altimetry profiles correlate surface morphology with features at the base including basal crevasses and marine ice formed by freezing on to the base of the ice shelf. Building Digital Elevation Models (DEMs) from the laser altimetry data, we investigate the relationship between the surface expressions of these ice shelf dynamics including thickness changes, potential sites of marine ice at the base and basal morphology in regions where a well defined basal reflector does not exist in the radar profiles. We present accuracy of the IcePod laser altimetry dataset using ground control points and GPS grids from Greenland and Antarctica as well as Photogrammetric DEMs. Our laser altimetry analysis resolves sub-meter surface features which, combined with coincident radar, provides a link between basal processes and their surface expressions.

  9. On the isolation of elemental carbon for micro-molar 14C accelerator mass spectrometry; evaluation of alternative isolation procedures, and accuracy assurance using a hybrid isotopic particulate carbon reference material

    OpenAIRE

    Currie, L A; Kessler,J.D.

    2005-01-01

    International audience; The primary objective of the research reported here has been the development of an hybrid reference material (RM) to serve as a test of accuracy for elemental carbon (EC) isotopic (14C) speciation measurements. Such measurements are critically important for the quantitative apportionment of fossil and biomass sources of ''soot'' (EC), the tracer of fire that has profound effects on health, atmospheric visibility, and climate. Previous studies of 14C-EC measurement qual...

  10. High-Accuracy Multi-Sensor Geolocation Technology to Support Geophysical Data Collection at MEC Sites

    Science.gov (United States)

    2010-07-01

    Landau, H., Pagels, C., and Wagner, B., (2000): Multi-Base RTK ositioning Using Virtual Reference Stations, ION GPS, 19–22 September 2000, Salt...Lake City, UT, pp. 123–131. 17. Wanninger, L. (2002): Virtual Reference Stations for Centimeter-Level Kinematic Positioning. ION GPS 2002, September 24

  11. High-accuracy acoustic detection of nonclassical component of material nonlinearity.

    Science.gov (United States)

    Haupert, Sylvain; Renaud, Guillaume; Rivière, Jacques; Talmant, Maryline; Johnson, Paul A; Laugier, Pascal

    2011-11-01

    The aim is to assess the nonclassical component of material nonlinearity in several classes of materials with weak, intermediate, and high nonlinear properties. In this contribution, an optimized nonlinear resonant ultrasound spectroscopy (NRUS) measuring and data processing protocol applied to small samples is described. The protocol is used to overcome the effects of environmental condition changes that take place during an experiment, and that may mask the intrinsic nonlinearity. External temperature fluctuation is identified as a primary source of measurement contamination. For instance, a variation of 0.1 °C produced a frequency variation of 0.01%, which is similar to the expected nonlinear frequency shift for weakly nonlinear materials. In order to overcome environmental effects, the reference frequency measurements are repeated before each excitation level and then used to compute nonlinear parameters. Using this approach, relative resonant frequency shifts of 10(-5) can be measured, which is below the limit of 10(-4) often considered as the limit of NRUS sensitivity under common experimental conditions. Due to enhanced sensitivity resulting from the correction procedure applied in this work, nonclassical nonlinearity in materials that before have been assumed to only be classically nonlinear in past work (steel, brass, and aluminum) is reported.

  12. High-accuracy local positioning network for the alignment of the Mu2e experiment.

    Energy Technology Data Exchange (ETDEWEB)

    Hejdukova, Jana B. [Czech Technical Univ., Prague (Czech Republic)

    2017-06-01

    This Diploma thesis describes the establishment of a high-precision local positioning network and accelerator alignment for the Mu2e physics experiment. The process of establishing new network consists of few steps: design of the network, pre-analysis, installation works, measurements of the network and making adjustments. Adjustments were performed using two approaches. First is a geodetic approach of taking into account the Earth’s curvature and the metrological approach of a pure 3D Cartesian system on the other side. The comparison of those two approaches is performed and evaluated in the results and compared with expected differences. The effect of the Earth’s curvature was found to be significant for this kind of network and should not be neglected. The measurements were obtained with Absolute Tracker AT401, leveling instrument Leica DNA03 and gyrotheodolite DMT Gyromat 2000. The coordinates of the points of the reference network were determined by the Least Square Meth od and the overall view is attached as Annexes.

  13. Millimeter-Wave Airborne Interferometry for High-accuracy Topography Mapping

    Science.gov (United States)

    Moller, D.; Hensley, S.; Wu, X.; Rodriguez, E.

    2011-12-01

    sensor geometry, bandwidth and number of channels needed for SWOT cal/val cannot be met within the framework of GLISTIN-A or a similar interface to UAVSAR. To address SWOT's cal/val requirements, the Ka-band SWOT Phenomenology Airborne Radar (KaSPAR) builds upon GLISTIN-A heritage and is the primary payload of the AirSWOT program. KaSPAR is a unique system with multiple temporal and cross-track baselines to fully characterize the scattering and statistics expected from SWOT, provide data for developing classification algorithms, and understanding instrument performance over the vast variety of scenes that SWOT will encounter. Furthermore a >5km swath high-accuracy WSE mapping capability provides the framework to translate traditional point or profile measurements to the spatial framework that SWOT will measure. Specific measurements from the integrated AirSWOT assembly are 1) WSE maps over a 5km swath with <3cm mean error at 100m x 100m postings (for ocean surface at 6m/s wind speed), 2) 2-D slope maps derived from WSE maps and 3) shoreline delineation at 10m resolution. These measurements will be made at resolutions exceeding that of SWOT to better characterize corrections for the spaceborne sensor.

  14. HIGH-ACCURACY BAND TO BAND REGISTRATION METHOD FOR MULTI-SPECTRAL IMAGES OF HJ-1A/B

    Institute of Scientific and Technical Information of China (English)

    Lu Hao; Liu Tuanjie; Zhao Haiqing

    2012-01-01

    Band-to-band registration accuracy is an important parameter of multispectral data.A novel band-to-band registration approach with high precision is proposed for the multi-spectral images of HJ-1A/B.Firstly,the main causes resulted in misregistration are analyzed,and a high-order polynomial model is proposed.Secondly,a phase fringe filtering technique is employed to Phase Correlation Method based on Singular Value Decomposition (SVD-PCM) for reducing the noise in phase difference matrix.Then,experiments are carried out to build nonlinear registration models,and images of green band and red band are aligned to blue band with an accuracy of 0.1 pixels,while near infrared band with an accuracy of 0.2 pixels.

  15. Accuracy analysis of continuous deformation monitoring using BeiDou Navigation Satellite System at middle and high latitudes in China

    Science.gov (United States)

    Jiang, Weiping; Xi, Ruijie; Chen, Hua; Xiao, Yugang

    2017-02-01

    As BeiDou Navigation Satellite System (BDS) has been operational in the whole Asia-Pacific region, it means a new GNSS system with a different satellite orbit structure will become available for deformation monitoring in the future. Conversely, GNSS deformation monitoring data are always processed with a regular interval to form displacement time series for deformation analysis, where the interval can neither be too long from the time perspective nor too short from the precision of determined displacements angle. In this paper, two experimental platforms were designed, with one being at mid-latitude and another at higher latitude in China. BDS data processing software was also developed for investigating the accuracy of continuous deformation monitoring using current in-orbit BDS satellites. Data over 20 days at both platforms were obtained and were processed every 2, 4 and 6 h to generate 3 displacement time series for comparison. The results show that with the current in-orbit BDS satellites, in the mid-latitude area it is easy to achieve accuracy of 1 mm in horizontal component and 2-3 mm in vertical component; the accuracy could be further improved to approximately 1 mm in both horizontal and vertical directions when combined BDS/GPS measurements are employed. At higher latitude, however, the results are not as good as expected due to poor satellite geometry, even the 6 h solutions could only achieve accuracy of 4-6 and 6-10 mm in horizontal and vertical components, respectively, which implies that it may not be applicable to very high-precision deformation monitoring at high latitude using the current BDS. With the integration of BDS and GPS observations, however, in 4-h session, the accuracy can achieve 2 mm in horizontal component and 4 mm in vertical component, which would be an optimal choice for high-accuracy structural deformation monitoring at high latitude.

  16. Spectroscopy of H3+ based on a new high-accuracy global potential energy surface.

    Science.gov (United States)

    Polyansky, Oleg L; Alijah, Alexander; Zobov, Nikolai F; Mizus, Irina I; Ovsyannikov, Roman I; Tennyson, Jonathan; Lodi, Lorenzo; Szidarovszky, Tamás; Császár, Attila G

    2012-11-13

    The molecular ion H(3)(+) is the simplest polyatomic and poly-electronic molecular system, and its spectrum constitutes an important benchmark for which precise answers can be obtained ab initio from the equations of quantum mechanics. Significant progress in the computation of the ro-vibrational spectrum of H(3)(+) is discussed. A new, global potential energy surface (PES) based on ab initio points computed with an average accuracy of 0.01 cm(-1) relative to the non-relativistic limit has recently been constructed. An analytical representation of these points is provided, exhibiting a standard deviation of 0.097 cm(-1). Problems with earlier fits are discussed. The new PES is used for the computation of transition frequencies. Recently measured lines at visible wavelengths combined with previously determined infrared ro-vibrational data show that an accuracy of the order of 0.1 cm(-1) is achieved by these computations. In order to achieve this degree of accuracy, relativistic, adiabatic and non-adiabatic effects must be properly accounted for. The accuracy of these calculations facilitates the reassignment of some measured lines, further reducing the standard deviation between experiment and theory.

  17. Analysis of the plasmodium falciparum proteome by high-accuracy mass spectrometry

    DEFF Research Database (Denmark)

    Lasonder, Edwin; Ishihama, Yasushi; Andersen, Jens S;

    2002-01-01

    -accuracy (average deviation less than 0.02 Da at 1,000 Da) mass spectrometric proteome analysis of selected stages of the human malaria parasite Plasmodium falciparum. The analysis revealed 1,289 proteins of which 714 proteins were identified in asexual blood stages, 931 in gametocytes and 645 in gametes. The last...

  18. Literature survey of high-impact journals revealed reporting weaknesses in abstracts of diagnostic accuracy studies

    NARCIS (Netherlands)

    Korevaar, Daniël A; Cohen, Jérémie F; Hooft, Lotty; Bossuyt, Patrick M M

    2015-01-01

    OBJECTIVES: Informative journal abstracts are crucial for the identification and initial appraisal of studies. We aimed to evaluate the informativeness of abstracts of diagnostic accuracy studies. STUDY DESIGN AND SETTING: PubMed was searched for reports of studies that had evaluated the diagnostic

  19. The effect of moderate and high-intensity fatigue on groundstroke accuracy in expert and non-expert tennis players.

    Science.gov (United States)

    Lyons, Mark; Al-Nakeeb, Yahya; Hankey, Joanne; Nevill, Alan

    2013-01-01

    Exploring the effects of fatigue on skilled performance in tennis presents a significant challenge to the researcher with respect to ecological validity. This study examined the effects of moderate and high-intensity fatigue on groundstroke accuracy in expert and non-expert tennis players. The research also explored whether the effects of fatigue are the same regardless of gender and player's achievement motivation characteristics. 13 expert (7 male, 6 female) and 17 non-expert (13 male, 4 female) tennis players participated in the study. Groundstroke accuracy was assessed using the modified Loughborough Tennis Skills Test. Fatigue was induced using the Loughborough Intermittent Tennis Test with moderate (70%) and high-intensities (90%) set as a percentage of peak heart rate (attained during a tennis-specific maximal hitting sprint test). Ratings of perceived exertion were used as an adjunct to the monitoring of heart rate. Achievement goal indicators for each player were assessed using the 2 x 2 Achievement Goals Questionnaire for Sport in an effort to examine if this personality characteristic provides insight into how players perform under moderate and high-intensity fatigue conditions. A series of mixed ANOVA's revealed significant fatigue effects on groundstroke accuracy regardless of expertise. The expert players however, maintained better groundstroke accuracy across all conditions compared to the novice players. Nevertheless, in both groups, performance following high-intensity fatigue deteriorated compared to performance at rest and performance while moderately fatigued. Groundstroke accuracy under moderate levels of fatigue was equivalent to that at rest. Fatigue effects were also similar regardless of gender. No fatigue by expertise, or fatigue by gender interactions were found. Fatigue effects were also equivalent regardless of player's achievement goal indicators. Future research is required to explore the effects of fatigue on performance in tennis

  20. High-accuracy real-time automatic thresholding for centroid tracker

    Science.gov (United States)

    Zhang, Ye; Wang, Yanjie

    2006-01-01

    Many of the video image trackers today use the centroid as the tracking point. In engineering, a target's centroid is computed from a binary image to reduce the processing time. Hence thresholding of gray level image to binary image is a decisive step in centroid tracking. How to choose the feat thresholds in clutter is still an intractability problem unsolved today. This paper introduces a high-accuracy real-time automatic thresholding method for centroid tracker. It works well for variety types of target tracking in clutter. The core of this method is to get the entire information contained in the histogram, such as the number of the peaks, their height, position and other properties in the histogram. Combine with this histogram analysis; we can get several key pairs of peaks which can include the target and the background around it and use the method of Otsu to get intensity thresholds from them. According to the thresholds, we can gain the binary image and get the centroid from it. To track the target, the paper also suggests subjoining an eyeshot-window, just like our eyes focus on a target, we will not miss it unless it is out of our eyeshot, the impression will help us to extract the target in clutter and track it and we will wait its emergence since it has been covered. To obtain the impression, the paper offers a idea comes from the method of Snakes; it give a great help for us to get a glancing size, so that we can compare the size of the object in the current frame with the former. If the change is little, we consider the object has been tracked well. Otherwise, if the change is bigger than usual, we should analyze the inflection in the histogram to find out what happened to the object. In general, what we have to do is turning the analysis into codes for the tracker to determine a feat threshold. The paper will show the steps in detail. The paper also discusses the hardware architecture which can meet the speed requirement.

  1. High-accuracy, high-resolution gravity profiles from 2 years of the Geosat Exact Repeat Mission

    Science.gov (United States)

    Sandwell, David T.; Mcadoo, David C.

    1990-01-01

    Satellite altimeter data from the first 44 repeat cycles (2 years) of the Geosat Exact Repeat Mission (EWRM) were averaged to improve accuracy, resolution and coverage of the marine gravity field. Individual 17-day repeat cycles were first edited and differentiated, resulting in the along-track vertical deflection (i.e., gravity disturbance). To increase the signal-to-noise ratio, 44 of these cycles were then averaged to form a single highly accurate vertical deflection profile. The largest contribution to the vertical deflection error is short-wavelength altimeter noise and longer-wavelength oceanographic variability; the combined noise level is typically 6 microrad. Both types of noise are reduced by averaging many repeat cycles. Over most ocean areas the uncertainty of the average profile is less than 1 microrad which corresponds to 1 mgal of along-track gravity disturbance. However, in areas of seasonal ice coverage, its uncertainty can exceed 5 microrad. To assess the resolution of individual and average Geosat gravity profiles, the cross-spectral analysis technique was applied to repeat profiles. Individual Geosat repeat cycles are coherent (greater than 0.5) for wavelengths greater than about 30 km and become increasingly incoherent at shorter wavelengths.

  2. The Effects of Individual or Group Guidelines on the Calibration Accuracy and Achievement of High School Biology Students

    Science.gov (United States)

    Bol, Linda; Hacker, Douglas J.; Walck, Camilla C.; Nunnery, John A.

    2012-01-01

    A 2 x 2 factorial design was employed in a quasi-experiment to investigate the effects of guidelines in group or individual settings on the calibration accuracy and achievement of 82 high school biology students. Significant main effects indicated that calibration practice with guidelines and practice in group settings increased prediction and…

  3. Accuracy of High-Resolution MRI with Lumen Distention in Rectal Cancer Staging and Circumferential Margin Involvement Prediction

    Energy Technology Data Exchange (ETDEWEB)

    Iannicelli, Elsa; Di Renzo, Sara [Radiology Institute, Faculty of Medicine and Psychology, University of Rome, Sapienza, Sant' Andrea Hospital, Rome 00189 (Italy); Department of Surgical and Medical Sciences and Translational Medicine, Faculty of Medicine and Psychology, University of Rome, Sapienza, Sant' Andrea Hospital, Rome 00189 (Italy); Ferri, Mario [Department of Surgical and Medical Sciences and Translational Medicine, Faculty of Medicine and Psychology, University of Rome, Sapienza, Sant' Andrea Hospital, Rome 00189 (Italy); Pilozzi, Emanuela [Department of Clinical and Molecular Sciences, Faculty of Medicine and Psychology, University of Rome, Sapienza, Sant' Andrea Hospital, Rome 00189 (Italy); Di Girolamo, Marco; Sapori, Alessandra [Radiology Institute, Faculty of Medicine and Psychology, University of Rome, Sapienza, Sant' Andrea Hospital, Rome 00189 (Italy); Department of Surgical and Medical Sciences and Translational Medicine, Faculty of Medicine and Psychology, University of Rome, Sapienza, Sant' Andrea Hospital, Rome 00189 (Italy); Ziparo, Vincenzo [Department of Surgical and Medical Sciences and Translational Medicine, Faculty of Medicine and Psychology, University of Rome, Sapienza, Sant' Andrea Hospital, Rome 00189 (Italy); David, Vincenzo [Radiology Institute, Faculty of Medicine and Psychology, University of Rome, Sapienza, Sant' Andrea Hospital, Rome 00189 (Italy); Department of Surgical and Medical Sciences and Translational Medicine, Faculty of Medicine and Psychology, University of Rome, Sapienza, Sant' Andrea Hospital, Rome 00189 (Italy)

    2014-07-01

    To evaluate the accuracy of magnetic resonance imaging (MRI) with lumen distention for rectal cancer staging and circumferential resection margin (CRM) involvement prediction. Seventy-three patients with primary rectal cancer underwent high-resolution MRI with a phased-array coil performed using 60-80 mL room air rectal distention, 1-3 weeks before surgery. MRI results were compared to postoperative histopathological findings. The overall MRI T staging accuracy was calculated. CRM involvement prediction and the N staging, the accuracy, sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) were assessed for each T stage. The agreement between MRI and histological results was assessed using weighted-kappa statistics. The overall MRI accuracy for T staging was 93.6% (k = 0.85). The accuracy, sensitivity, specificity, PPV and NPV for each T stage were as follows: 91.8%, 86.2%, 95.5%, 92.6% and 91.3% for the group ≤ T2; 90.4%, 94.6%, 86.1%, 87.5% and 94% for T3; 98,6%, 85.7%, 100%, 100% and 98.5% for T4, respectively. The predictive CRM accuracy was 94.5% (k = 0.86); the sensitivity, specificity, PPV and NPV were 89.5%, 96.3%, 89.5%, and 96.3% respectively. The N staging accuracy was 68.49% (k = 0.4). MRI performed with rectal lumen distention has proved to be an effective technique both for rectal cancer staging and involved CRM predicting.

  4. Real-time displacement measurement with large range and high accuracy using sinusoidal phase modulating laser diode interferometer

    Institute of Scientific and Technical Information of China (English)

    Guotian He; Xiangzhao Wang; Aijun Zeng; Feng Tang; Bingjie Huang

    2007-01-01

    To resolve the conflict of large measurement range and high accuracy in the existing real-time displacement measurement laser diode (LD) interferometers, a novel real-time displacement measurement LD interferometry is proposed and its measurement principle is analyzed. By use of a new phase demodulation algorithm and a new phase compensation lgorithm of real-time phase unwrapping, the measurement accuracy is improved, and the measurement range is enlarged to a few wavelengths. In experiments, the peak-to-peak amplitude of the speaker vibration was 2361.7 nm, and the repeatability was 2.56 nm. The measurement time was less than 26μs.

  5. A survey of reference electrodes for high temperature waters; Oeversikt av referenselektroder i hoegtemperaturvatten

    Energy Technology Data Exchange (ETDEWEB)

    Molander, A.; Eriksson, Sture; Pein, K. [Studsvik Nuclear, Nykoeping (Sweden)

    2000-11-01

    In nuclear power plants, corrosion potential measurements are used to follow the conditions for different corrosion types in reactor systems, particularly IGSCC in BWRs. The goal of this work has been to give a survey of reference electrodes for high temperature water, both those that are used for nuclear environments and those that are judged to possible future development. The reference electrodes that are used today in nuclear power plants for corrosion potential measurements are of three types. Silver chloride electrodes, membrane electrodes and platinum electrodes (hydrogen electrodes). The principals for their function is described as well as the conversion of measured potentials to the SHE scale (Standard Hydrogen Electrode). Silver chloride electrodes consist of an inner reference system of silver chloride in equilibrium with a chloride solution. The silver chloride electrode is the most common reference electrode and can be used in several different systems. Platinum electrodes are usually more robust and are particularly suitable to use in BWR environment to follow the hydrogen dosage, but have limitations at low and no hydrogen dosage. Ceramic membrane electrodes can be with different types of internal reference system. They were originally developed for pH measurements in high temperature water. If pH is constant, the membrane electrode can be used as reference electrode. A survey of ceramic reference electrodes for high temperature water is given. A ceramic membrane of the type used works as an oxygen conductor, so the potential and pH in surrounding medium is in equilibrium with the internal reference system. A survey of the lately development of electrodes is presented in order to explain why the different types of electrodes are developed as well as to give a background to the possibilities and limitations with the different electrodes. Possibilities of future development of electrodes are also given. For measurements at low or no hydrogen dosage

  6. Perturbational treatment of spin-orbit coupling for generally applicable high-level multi-reference methods

    Energy Technology Data Exchange (ETDEWEB)

    Mai, Sebastian; Marquetand, Philipp; González, Leticia [Institute of Theoretical Chemistry, University of Vienna, Währinger Str. 17, 1090 Vienna (Austria); Müller, Thomas, E-mail: th.mueller@fz-juelich.de [Institute for Advanced Simulation, Jülich Supercomputing Centre, Forschungszentrum Jülich, 52425 Jülich (Germany); Plasser, Felix [Interdisciplinary Center for Scientific Computing, University of Heidelberg, Im Neuenheimer Feld 368, 69120 Heidelberg (Germany); Lischka, Hans [Institute of Theoretical Chemistry, University of Vienna, Währinger Str. 17, 1090 Vienna (Austria); Department of Chemistry and Biochemistry, Texas Tech University, Lubbock, Texas 79409-1061 (United States)

    2014-08-21

    An efficient perturbational treatment of spin-orbit coupling within the framework of high-level multi-reference techniques has been implemented in the most recent version of the COLUMBUS quantum chemistry package, extending the existing fully variational two-component (2c) multi-reference configuration interaction singles and doubles (MRCISD) method. The proposed scheme follows related implementations of quasi-degenerate perturbation theory (QDPT) model space techniques. Our model space is built either from uncontracted, large-scale scalar relativistic MRCISD wavefunctions or based on the scalar-relativistic solutions of the linear-response-theory-based multi-configurational averaged quadratic coupled cluster method (LRT-MRAQCC). The latter approach allows for a consistent, approximatively size-consistent and size-extensive treatment of spin-orbit coupling. The approach is described in detail and compared to a number of related techniques. The inherent accuracy of the QDPT approach is validated by comparing cuts of the potential energy surfaces of acrolein and its S, Se, and Te analoga with the corresponding data obtained from matching fully variational spin-orbit MRCISD calculations. The conceptual availability of approximate analytic gradients with respect to geometrical displacements is an attractive feature of the 2c-QDPT-MRCISD and 2c-QDPT-LRT-MRAQCC methods for structure optimization and ab inito molecular dynamics simulations.

  7. Perturbational treatment of spin-orbit coupling for generally applicable high-level multi-reference methods.

    Science.gov (United States)

    Mai, Sebastian; Müller, Thomas; Plasser, Felix; Marquetand, Philipp; Lischka, Hans; González, Leticia

    2014-08-21

    An efficient perturbational treatment of spin-orbit coupling within the framework of high-level multi-reference techniques has been implemented in the most recent version of the Columbus quantum chemistry package, extending the existing fully variational two-component (2c) multi-reference configuration interaction singles and doubles (MRCISD) method. The proposed scheme follows related implementations of quasi-degenerate perturbation theory (QDPT) model space techniques. Our model space is built either from uncontracted, large-scale scalar relativistic MRCISD wavefunctions or based on the scalar-relativistic solutions of the linear-response-theory-based multi-configurational averaged quadratic coupled cluster method (LRT-MRAQCC). The latter approach allows for a consistent, approximatively size-consistent and size-extensive treatment of spin-orbit coupling. The approach is described in detail and compared to a number of related techniques. The inherent accuracy of the QDPT approach is validated by comparing cuts of the potential energy surfaces of acrolein and its S, Se, and Te analoga with the corresponding data obtained from matching fully variational spin-orbit MRCISD calculations. The conceptual availability of approximate analytic gradients with respect to geometrical displacements is an attractive feature of the 2c-QDPT-MRCISD and 2c-QDPT-LRT-MRAQCC methods for structure optimization and ab inito molecular dynamics simulations.

  8. Geometric Accuracy Investigations of SEVIRI High Resolution Visible (HRV Level 1.5 Imagery

    Directory of Open Access Journals (Sweden)

    Sultan Kocaman Aksakal

    2013-05-01

    Full Text Available GCOS (Global Climate Observing System is a long-term program for monitoring the climate, detecting the changes, and assessing their impacts. Remote sensing techniques are being increasingly used for climate-related measurements. Imagery of the SEVIRI instrument on board of the European geostationary satellites Meteosat-8 and Meteosat-9 are often used for the estimation of essential climate variables. In a joint project between the Swiss GCOS Office and ETH Zurich, geometric accuracy and temporal stability of 1-km resolution HRV channel imagery of SEVIRI have been evaluated over Switzerland. A set of tools and algorithms has been developed for the investigations. Statistical analysis and blunder detection have been integrated in the process for robust evaluation. The relative accuracy is evaluated by tracking large numbers of feature points in consecutive HRV images taken at 15-minute intervals. For the absolute accuracy evaluation, lakes in Switzerland and surroundings are used as reference. 20 lakes digitized from Landsat orthophotos are transformed into HRV images and matched via 2D translation terms at sub-pixel level. The algorithms are tested using HRV images taken on 24 days in 2008 (2 days per month. The results show that 2D shifts that are up to 8 pixels are present both in relative and absolute terms.

  9. High-accuracy extrapolated ab initio thermochemistry. II. Minor improvements to the protocol and a vital simplification

    Science.gov (United States)

    Bomble, Yannick J.; Vázquez, Juana; Kállay, Mihály; Michauk, Christine; Szalay, Péter G.; Császár, Attila G.; Gauss, Jürgen; Stanton, John F.

    2006-08-01

    The recently developed high-accuracy extrapolated ab initio thermochemistry method for theoretical thermochemistry, which is intimately related to other high-precision protocols such as the Weizmann-3 and focal-point approaches, is revisited. Some minor improvements in theoretical rigor are introduced which do not lead to any significant additional computational overhead, but are shown to have a negligible overall effect on the accuracy. In addition, the method is extended to completely treat electron correlation effects up to pentuple excitations. The use of an approximate treatment of quadruple and pentuple excitations is suggested; the former as a pragmatic approximation for standard cases and the latter when extremely high accuracy is required. For a test suite of molecules that have rather precisely known enthalpies of formation {as taken from the active thermochemical tables of Ruscic and co-workers [Lecture Notes in Computer Science, edited by M. Parashar (Springer, Berlin, 2002), Vol. 2536, pp. 25-38; J. Phys. Chem. A 108, 9979 (2004)]}, the largest deviations between theory and experiment are 0.52, -0.70, and 0.51kJmol-1 for the latter three methods, respectively. Some perspective is provided on this level of accuracy, and sources of remaining systematic deficiencies in the approaches are discussed.

  10. SFOL Pulse: A High Accuracy DME Pulse for Alternative Aircraft Position and Navigation

    Directory of Open Access Journals (Sweden)

    Euiho Kim

    2017-09-01

    Full Text Available In the Federal Aviation Administration’s (FAA performance based navigation strategy announced in 2016, the FAA stated that it would retain and expand the Distance Measuring Equipment (DME infrastructure to ensure resilient aircraft navigation capability during the event of a Global Navigation Satellite System (GNSS outage. However, the main drawback of the DME as a GNSS back up system is that it requires a significant expansion of the current DME ground infrastructure due to its poor distance measuring accuracy over 100 m. The paper introduces a method to improve DME distance measuring accuracy by using a new DME pulse shape. The proposed pulse shape was developed by using Genetic Algorithms and is less susceptible to multipath effects so that the ranging error reduces by 36.0–77.3% when compared to the Gaussian and Smoothed Concave Polygon DME pulses, depending on noise environment.

  11. Friction compensation design based on state observer and adaptive law for high-accuracy positioning system

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    Friction is one of the main factors that affect the positioning accuracy of motion system. Friction compensation based on friction model is usually adopted to eliminate the nonlinear effect of friction. This paper presents a proportional-plus-derivative (PD) feedback controller with a friction compensator based on LuGre friction model. We also design a state observer to observe the unknown state of LuGre friction model, and adopt a parameter adaptive law and off-line approximation to estimate the parameters of LuGre friction model. Comparative experiments are carried out among our proposed controller, PD controller with friction compensation based on classical friction model, and PD controller without friction compensation. Experimental results demonstrate that our proposed controller can achieve better performance, especially higher positioning accuracy.

  12. Ways to help Chinese Students in Senior High School improve language accuracy in writing

    Institute of Scientific and Technical Information of China (English)

    潘惠红

    2015-01-01

    <正>Introduction In Chinese ELT(English language teaching),as in other countries,both fluency and accuracy are considered important either in the teaching or assessment of writing.In this respect,the last decade has seen reforms in the College Entrance Examination in Guangdong Province.With two writing tasks being set as assessment,task one requires students to summarise Chinese language information into five English sentences while the

  13. A High-Accuracy Linear Conservative Difference Scheme for Rosenau-RLW Equation

    Directory of Open Access Journals (Sweden)

    Jinsong Hu

    2013-01-01

    Full Text Available We study the initial-boundary value problem for Rosenau-RLW equation. We propose a three-level linear finite difference scheme, which has the theoretical accuracy of Oτ2+h4. The scheme simulates two conservative properties of original problem well. The existence, uniqueness of difference solution, and a priori estimates in infinite norm are obtained. Furthermore, we analyze the convergence and stability of the scheme by energy method. At last, numerical experiments demonstrate the theoretical results.

  14. High-accuracy current measurement with low-cost shunts by means of dynamic error correction

    OpenAIRE

    Weßkamp, Patrick; Melbert, Joachim

    2016-01-01

    Measurement of electrical current is often performed by using shunt resistors. Thermal effects due to self-heating and ambient temperature variation limit the achievable accuracy, especially if low-cost shunt resistors with increased temperature coefficients are utilized. In this work, a compensation method is presented which takes static and dynamic temperature drift effects into account and provides a significant reduction of measurement error. A thermal model of the shunt...

  15. A high-accuracy optical linear algebra processor for finite element applications

    Science.gov (United States)

    Casasent, D.; Taylor, B. K.

    1984-01-01

    Optical linear processors are computationally efficient computers for solving matrix-matrix and matrix-vector oriented problems. Optical system errors limit their dynamic range to 30-40 dB, which limits their accuray to 9-12 bits. Large problems, such as the finite element problem in structural mechanics (with tens or hundreds of thousands of variables) which can exploit the speed of optical processors, require the 32 bit accuracy obtainable from digital machines. To obtain this required 32 bit accuracy with an optical processor, the data can be digitally encoded, thereby reducing the dynamic range requirements of the optical system (i.e., decreasing the effect of optical errors on the data) while providing increased accuracy. This report describes a new digitally encoded optical linear algebra processor architecture for solving finite element and banded matrix-vector problems. A linear static plate bending case study is described which quantities the processor requirements. Multiplication by digital convolution is explained, and the digitally encoded optical processor architecture is advanced.

  16. Will it Blend? Visualization and Accuracy Evaluation of High-Resolution Fuzzy Vegetation Maps

    Science.gov (United States)

    Zlinszky, A.; Kania, A.

    2016-06-01

    Instead of assigning every map pixel to a single class, fuzzy classification includes information on the class assigned to each pixel but also the certainty of this class and the alternative possible classes based on fuzzy set theory. The advantages of fuzzy classification for vegetation mapping are well recognized, but the accuracy and uncertainty of fuzzy maps cannot be directly quantified with indices developed for hard-boundary categorizations. The rich information in such a map is impossible to convey with a single map product or accuracy figure. Here we introduce a suite of evaluation indices and visualization products for fuzzy maps generated with ensemble classifiers. We also propose a way of evaluating classwise prediction certainty with "dominance profiles" visualizing the number of pixels in bins according to the probability of the dominant class, also showing the probability of all the other classes. Together, these data products allow a quantitative understanding of the rich information in a fuzzy raster map both for individual classes and in terms of variability in space, and also establish the connection between spatially explicit class certainty and traditional accuracy metrics. These map products are directly comparable to widely used hard boundary evaluation procedures, support active learning-based iterative classification and can be applied for operational use.

  17. High accuracy integrated global positioning system/inertial navigation system LDRD: Final report

    Energy Technology Data Exchange (ETDEWEB)

    Owen, T.E.; Meindl, M.A.; Fellerhoff, J.R.

    1997-03-01

    This report contains the results of a Sandia National Laboratories Directed Research and Development (LDRD) program to investigate the integration of Global Positioning System (GPS) and inertial navigation system (INS) technologies toward the goal of optimizing the navigational accuracy of the combined GPSANS system. The approach undertaken is to integrate the data from an INS, which has long term drifts, but excellent short term accuracy, with GPS carrier phase signal information, which is accurate to the sub-centimeter level, but requires continuous tracking of the GPS signals. The goal is to maintain a sub-meter accurate navigation solution while the vehicle is in motion by using the GPS measurements to estimate the INS navigation errors and then using the refined INS data to aid the GPS carrier phase cycle slip detection and correction and bridge dropouts in the GPS data. The work was expanded to look at GPS-based attitude determination, using multiple GPS receivers and antennas on a single platform, as a possible navigation aid. Efforts included not only the development of data processing algorithms and software, but also the collection and analysis of GPS and INS flight data aboard a Twin Otter aircraft. Finally, the application of improved navigation system accuracy to synthetic aperture radar (SAR) target location is examined.

  18. THE EFFECT OF MODERATE AND HIGH-INTENSITY FATIGUE ON GROUNDSTROKE ACCURACY IN EXPERT AND NON-EXPERT TENNIS PLAYERS

    Directory of Open Access Journals (Sweden)

    Mark Lyons

    2013-06-01

    Full Text Available Exploring the effects of fatigue on skilled performance in tennis presents a significant challenge to the researcher with respect to ecological validity. This study examined the effects of moderate and high-intensity fatigue on groundstroke accuracy in expert and non-expert tennis players. The research also explored whether the effects of fatigue are the same regardless of gender and player's achievement motivation characteristics. 13 expert (7 male, 6 female and 17 non-expert (13 male, 4 female tennis players participated in the study. Groundstroke accuracy was assessed using the modified Loughborough Tennis Skills Test. Fatigue was induced using the Loughborough Intermittent Tennis Test with moderate (70% and high-intensities (90% set as a percentage of peak heart rate (attained during a tennis-specific maximal hitting sprint test. Ratings of perceived exertion were used as an adjunct to the monitoring of heart rate. Achievement goal indicators for each player were assessed using the 2 x 2 Achievement Goals Questionnaire for Sport in an effort to examine if this personality characteristic provides insight into how players perform under moderate and high-intensity fatigue conditions. A series of mixed ANOVA's revealed significant fatigue effects on groundstroke accuracy regardless of expertise. The expert players however, maintained better groundstroke accuracy across all conditions compared to the novice players. Nevertheless, in both groups, performance following high-intensity fatigue deteriorated compared to performance at rest and performance while moderately fatigued. Groundstroke accuracy under moderate levels of fatigue was equivalent to that at rest. Fatigue effects were also similar regardless of gender. No fatigue by expertise, or fatigue by gender interactions were found. Fatigue effects were also equivalent regardless of player's achievement goal indicators. Future research is required to explore the effects of fatigue on

  19. Method for high-accuracy reflectance measurements in the 2.5-microm region.

    Science.gov (United States)

    Richter, Rudolf; Müller, Andreas

    2003-02-20

    Reflectance measurement with spectroradiometers in the solar wavelength region (0.4-2.5 microm) are frequently conducted in the laboratory or in the field to characterize surface materials of artificial and natural targets. The spectral surface reflectance is calculated as the ratio of the signals obtained over the target surface and a reference panel, yielding a relative reflectance value. If the reflectance of the reference panel is known, the absolute target reflectance can be computed. This standard measurement technique assumes that the signal at the radiometer is due completely to reflected target and reference radiation. However, for field measurements in the 2.4-2.5-microm region with the Sun as the illumination source, the emitted thermal radiation is not a negligible part of the signal even at ambient temperatures, because the atmospheric transmittance, and thus the solar illumination level, is small in the atmospheric absorption regions. A new method is proposed that calculates reflectance values in the 2.4-2.5-microm region while it accounts for the reference panel reflectance and the emitted radiation. This technique needs instruments with noise-equivalent radiances of 2 orders of magnitude below currently commercially available instruments and requires measurement of the surface temperatures of target and reference. If the reference panel reflectance and temperature effects are neglected, the standard method yields reflectance errors up to 0.08 and 0.15 units for 7- and 2-nm bandwidth instruments, respectively. For the new method the corresponding errors can be reduced to approximately 0.01 units for the surface temperature range of 20-35 degrees C.

  20. High-precision, accurate optical frequency reference using a Fabry-Perót diode laser.

    Science.gov (United States)

    Chang, Hongrok; Myneni, Krishna; Smith, David D; Liaghati-Mobarhan, Hassan R

    2017-06-01

    We show that the optical output of a temperature and current-tuned Fabry-Perót diode laser system, with no external optical feedback and in which the frequency is locked to Doppler-free hyperfine resonances of the (87)Rb D2 line, can achieve high frequency stability and accuracy. Experimental results are presented for the spectral linewidth, frequency stability, and frequency accuracy of the source. Although our optical source is limited by a short-term spectral linewidth greater than 2 MHz, beat signal measurements from two such sources demonstrate a frequency stability of 1.1 kHz, or minimum Allan deviation of 4×10(-12), at an integration time τ=15 s and with a frequency accuracy of 60 kHz at τ=300 s. We demonstrate the use of the optical source for the precision measurement of hyperfine level frequency spacings in the 5P3∕2 excited state of (87)Rb and provide an accurate frequency scale for optical spectroscopy.

  1. Horizontal Positional Accuracy of Google Earth’s High-Resolution Imagery Archive

    Directory of Open Access Journals (Sweden)

    David Potere

    2008-12-01

    Full Text Available Google Earth now hosts high-resolution imagery that spans twenty percent of the Earth’s landmass and more than a third of the human population. This contemporary highresolution archive represents a significant, rapidly expanding, cost-free and largely unexploited resource for scientific inquiry. To increase the scientific utility of this archive, we address horizontal positional accuracy (georegistration by comparing Google Earth with Landsat GeoCover scenes over a global sample of 436 control points located in 109 cities worldwide. Landsat GeoCover is an orthorectified product with known absolute positional accuracy of less than 50 meters root-mean-squared error (RMSE. Relative to Landsat GeoCover, the 436 Google Earth control points have a positional accuracy of 39.7 meters RMSE (error magnitudes range from 0.4 to 171.6 meters. The control points derived from satellite imagery have an accuracy of 22.8 meters RMSE, which is significantly more accurate than the 48 control-points based on aerial photography (41.3 meters RMSE; t-test p-value < 0.01. The accuracy of control points in more-developed countries is 24.1 meters RMSE, which is significantly more accurate than the control points in developing countries (44.4 meters RMSE; t-test p-value < 0.01. These findings indicate that Google Earth highresolution imagery has a horizontal positional accuracy that is sufficient for assessing moderate-resolution remote sensing products across most of the world’s peri-urban areas.

  2. Error correction algorithm for high accuracy bio-impedance measurement in wearable healthcare applications.

    Science.gov (United States)

    Kubendran, Rajkumar; Lee, Seulki; Mitra, Srinjoy; Yazicioglu, Refet Firat

    2014-04-01

    Implantable and ambulatory measurement of physiological signals such as Bio-impedance using miniature biomedical devices needs careful tradeoff between limited power budget, measurement accuracy and complexity of implementation. This paper addresses this tradeoff through an extensive analysis of different stimulation and demodulation techniques for accurate Bio-impedance measurement. Three cases are considered for rigorous analysis of a generic impedance model, with multiple poles, which is stimulated using a square/sinusoidal current and demodulated using square/sinusoidal clock. For each case, the error in determining pole parameters (resistance and capacitance) is derived and compared. An error correction algorithm is proposed for square wave demodulation which reduces the peak estimation error from 9.3% to 1.3% for a simple tissue model. Simulation results in Matlab using ideal RC values show an average accuracy of for single pole and for two pole RC networks. Measurements using ideal components for a single pole model gives an overall and readings from saline phantom solution (primarily resistive) gives an . A Figure of Merit is derived based on ability to accurately resolve multiple poles in unknown impedance with minimal measurement points per decade, for given frequency range and supply current budget. This analysis is used to arrive at an optimal tradeoff between accuracy and power. Results indicate that the algorithm is generic and can be used for any application that involves resolving poles of an unknown impedance. It can be implemented as a post-processing technique for error correction or even incorporated into wearable signal monitoring ICs.

  3. A High-accuracy Approach to Pronunciation Prediction for Out-of-vocabulary English Word

    Institute of Scientific and Technical Information of China (English)

    WANG Hao; CHEN Gui-lin; XU Liang-xian

    2005-01-01

    Letter-to-Sound conversion is one of the fundamental issues in text-to-speech synthesis. In this paper, we address an approach to automatic prediction of word pronunciation. This approach combines example-based learning and dynamic-programming searching to predict sub-word pronunciation. Word pronunciation is formed by concatenating sub-word pronunciations. We conducted comparative experiments over a large-scale English dictionary. Experimental results show that this approach can achieve accuracy of 70.1%, which outperforms those published results.

  4. High accuracy wavelength locking of a DFB laser using tunable polarization interference filter

    Institute of Scientific and Technical Information of China (English)

    Xiyao Chen(陈曦曜); Jianping Xie(谢建平); Tianpeng Zhao(赵天鹏); Hai Ming(明海); Anting Wang(王安廷); Wencai Huang(黄文财); Liang Lü(吕亮); Lixin Xu(许立新)

    2003-01-01

    A temperature-tunable polarization interference filter (PIF) made of YVO4 crystal has been presented and applied for wavelength locking of a distributed feedback (DFB) semiconductor laser in dense wavelength-division-multiplexing (DWDM) optical communication systems. This new design offers a flexible way to monitor and then lock an operating wavelength of DFB laser to any preselected point without dead spots.The results show that the laser wavelength can be locked with accuracy better than ±0.01 nm with much relaxed requirement on temperature stability of the filter.

  5. High-accuracy mass determination of unstable cesium and barium isotopes

    CERN Document Server

    Ames, F; Beck, D; Bollen, G; De Saint-Simon, M; Jertz, R; Kluge, H J; Kohl, A; König, M; Lunney, M D; Martel, I; Moore, R B; Otto, T; Patyk, Z; Raimbault-Hartmann, H; Rouleau, G; Savard, G; Schark, E; Schwarz, S; Schweikhard, L; Stolzenberg, H; Szerypo, J

    1999-01-01

    Direct mass measurements of short-lived Cs and Ba isotopes have been performed with the tandem Penning trap mass spectrometer ISOLTRAP installed at the on-line isotope separator ISOLDE at CERN. Typically, a mass resolving power of 600 000 and an accuracy of $\\delta \\mbox{m} \\approx 13$ keV have been obtained. The masses of $^{123,124,126}$Ba and $^{122m}$Cs were measured for the first time. A least-squares adjustment has been performed and the experimental masses are compared with theoretical ones, particularly in the frame of a macroscopic-microscopic model.

  6. High-accuracy mass determination of neutron-rich rubidium and strontiumiIsotopes

    CERN Document Server

    Raimbault-Hartmann, H; Beck, D; Bollen, G; De Saint-Simon, M; Kluge, H J; König, M; Moore, R B; Schwarz, S; Savard, G; Szerypo, J

    2002-01-01

    The penning-trap mass spectrometer ISOLTRAP, installed at the on-line isotope separator ISOLDE at CERN, has been used to measure atomic masses of $^{88,89,90m,91,92,93,94}$Rb and $^{91- 95}$Sr. Using a resolving power of R $\\!\\scriptstyle\\approx$1 million a mass accuracy of typically 10 keV was achieved for all nuclides. Discrepancies with older data are analyzed and discussed, leading to corrections to those data. Together with the present ISOLTRAP data these corrected data have been used in the general mass adjustment.

  7. High-Accuracy Measurements of the Centre of Gravity of Avalanches in Proportional Chambers

    Science.gov (United States)

    Charpak, G.; Jeavons, A.; Sauli, F.; Stubbs, R.

    1973-09-24

    In a multiwire proportional chamber the avalanches occur close to the anode wires. The motion of the positive ions in the large electric fields at the vicinity of the wires induces fast-rising positive pulses on the surrounding electrodes. Different methods have been developed in order to determine the position of the centre of the avalanches. In the method we describe, the centre of gravity of the pulse distribution is measured directly. It seems to lead to an accuracy which is limited only by the stability of the spatial distribution of the avalanches generated by the process being measured.

  8. High-Accuracy Tracking Control of Robot Manipulators Using Time Delay Estimation and Terminal Sliding Mode

    Directory of Open Access Journals (Sweden)

    Maolin Jin

    2011-09-01

    Full Text Available A time delay estimation based general framework for trajectory tracking control of robot manipulators is presented. The controller consists of three elements: a time‐delay‐estimation element that cancels continuous nonlinearities of robot dynamics, an injecting element that endows desired error dynamics, and a correcting element that suppresses residual time delay estimation error caused by discontinuous nonlinearities. Terminal sliding mode is used for the correcting element to pursue fast convergence of the time delay estimation error. Implementation of proposed control is easy because calculation of robot dynamics including friction is not required. Experimental results verify high‐accuracy trajectory tracking of industrial robot manipulators.

  9. Predictors of the accuracy of quotation of references in peer-reviewed orthopaedic literature in relation to publications on the scaphoid.

    Science.gov (United States)

    Buijze, G A; Weening, A A; Poolman, R W; Bhandari, M; Ring, D

    2012-02-01

    Using inaccurate quotations can propagate misleading information, which might affect the management of patients. The aim of this study was to determine the predictors of quotation inaccuracy in the peer-reviewed orthopaedic literature related to the scaphoid. We randomly selected 100 papers from ten orthopaedic journals. All references were retrieved in full text when available or otherwise excluded. Two observers independently rated all quotations from the selected papers by comparing the claims made by the authors with the data and expressed opinions of the reference source. A statistical analysis determined which article-related factors were predictors of quotation inaccuracy. The mean total inaccuracy rate of the 3840 verified quotes was 7.6%. There was no correlation between the rate of inaccuracy and the impact factor of the journal. Multivariable analysis identified the journal and the type of study (clinical, biomechanical, methodological, case report or review) as important predictors of the total quotation inaccuracy rate. We concluded that inaccurate quotations in the peer-reviewed orthopaedic literature related to the scaphoid were common and slightly more so for certain journals and certain study types. Authors, reviewers and editorial staff play an important role in reducing this inaccuracy.

  10. Reference design and operations for deep borehole disposal of high-level radioactive waste.

    Energy Technology Data Exchange (ETDEWEB)

    Herrick, Courtney Grant; Brady, Patrick Vane; Pye, Steven; Arnold, Bill Walter; Finger, John Travis; Bauer, Stephen J.

    2011-10-01

    A reference design and operational procedures for the disposal of high-level radioactive waste in deep boreholes have been developed and documented. The design and operations are feasible with currently available technology and meet existing safety and anticipated regulatory requirements. Objectives of the reference design include providing a baseline for more detailed technical analyses of system performance and serving as a basis for comparing design alternatives. Numerous factors suggest that deep borehole disposal of high-level radioactive waste is inherently safe. Several lines of evidence indicate that groundwater at depths of several kilometers in continental crystalline basement rocks has long residence times and low velocity. High salinity fluids have limited potential for vertical flow because of density stratification and prevent colloidal transport of radionuclides. Geochemically reducing conditions in the deep subsurface limit the solubility and enhance the retardation of key radionuclides. A non-technical advantage that the deep borehole concept may offer over a repository concept is that of facilitating incremental construction and loading at multiple perhaps regional locations. The disposal borehole would be drilled to a depth of 5,000 m using a telescoping design and would be logged and tested prior to waste emplacement. Waste canisters would be constructed of carbon steel, sealed by welds, and connected into canister strings with high-strength connections. Waste canister strings of about 200 m length would be emplaced in the lower 2,000 m of the fully cased borehole and be separated by bridge and cement plugs. Sealing of the upper part of the borehole would be done with a series of compacted bentonite seals, cement plugs, cement seals, cement plus crushed rock backfill, and bridge plugs. Elements of the reference design meet technical requirements defined in the study. Testing and operational safety assurance requirements are also defined. Overall

  11. Affine-Invariant Geometric Constraints-Based High Accuracy Simultaneous Localization and Mapping

    Directory of Open Access Journals (Sweden)

    Gangchen Hua

    2017-01-01

    Full Text Available In this study we describe a new appearance-based loop-closure detection method for online incremental simultaneous localization and mapping (SLAM using affine-invariant-based geometric constraints. Unlike other pure bag-of-words-based approaches, our proposed method uses geometric constraints as a supplement to improve accuracy. By establishing an affine-invariant hypothesis, the proposed method excludes incorrect visual words and calculates the dispersion of correctly matched visual words to improve the accuracy of the likelihood calculation. In addition, camera’s intrinsic parameters and distortion coefficients are adequate for this method. 3D measuring is not necessary. We use the mechanism of Long-Term Memory and Working Memory (WM to manage the memory. Only a limited size of the WM is used for loop-closure detection; therefore the proposed method is suitable for large-scale real-time SLAM. We tested our method using the CityCenter and Lip6Indoor datasets. Our proposed method results can effectively correct the typical false-positive localization of previous methods, thus gaining better recall ratios and better precision.

  12. High-accuracy 3-D modeling of cultural heritage: the digitizing of Donatello's "Maddalena".

    Science.gov (United States)

    Guidi, Gabriele; Beraldin, J Angelo; Atzeni, Carlo

    2004-03-01

    Three-dimensional digital modeling of Heritage works of art through optical scanners, has been demonstrated in recent years with results of exceptional interest. However, the routine application of three-dimensional (3-D) modeling to Heritage conservation still requires the systematic investigation of a number of technical problems. In this paper, the acquisition process of the 3-D digital model of the Maddalena by Donatello, a wooden statue representing one of the major masterpieces of the Italian Renaissance which was swept away by the Florence flood of 1966 and successively restored, is described. The paper reports all the steps of the acquisition procedure, from the project planning to the solution of the various problems due to range camera calibration and to material non optically cooperative. Since the scientific focus is centered on the 3-D model overall dimensional accuracy, a methodology for its quality control is described. Such control has demonstrated how, in some situations, the ICP-based alignment can lead to incorrect results. To circumvent this difficulty we propose an alignment technique based on the fusion of ICP with close-range digital photogrammetry and a non-invasive procedure in order to generate a final accurate model. In the end detailed results are presented, demonstrating the improvement of the final model, and how the proposed sensor fusion ensure a pre-specified level of accuracy.

  13. Axis-Exchanged Compensation and Gait Parameters Analysis for High Accuracy Indoor Pedestrian Dead Reckoning

    Directory of Open Access Journals (Sweden)

    Honghui Zhang

    2015-01-01

    Full Text Available Pedestrian dead reckoning (PDR is an effective way for navigation coupled with GNSS (Global Navigation Satellite System or weak GNSS signal environment like indoor scenario. However, indoor location with an accuracy of 1 to 2 meters determined by PDR based on MEMS-IMU is still very challenging. For one thing, heading estimation is an important problem in PDR because of the singularities. For another thing, walking distance estimation is also a critical problem for pedestrian walking with randomness. Based on the above two problems, this paper proposed axis-exchanged compensation and gait parameters analysis algorithm to improve the navigation accuracy. In detail, an axis-exchanged compensation factored quaternion algorithm is put forward first to overcome the singularities in heading estimation without increasing the amount of computation. Besides, real-time heading is updated by R-adaptive Kalman filter. Moreover, gait parameters analysis algorithm can be divided into two steps: cadence detection and step length estimation. Thus, a method of cadence classification and interval symmetry is proposed to detect the cadence accurately. Furthermore, a step length model adjusted by cadence is established for step length estimation. Compared to the traditional PDR navigation, experimental results showed that the error of navigation reduces 32.6%.

  14. High accuracy 235U(n,f data in the resonance energy region

    Directory of Open Access Journals (Sweden)

    Paradela C.

    2016-01-01

    Full Text Available The 235U neutron-induced cross section is widely used as reference cross section for measuring other fission cross sections, but in the resonance region it is not considered as an IAEA standard because of the scarce experimental data covering the full region. In this work, we deal with a new analysis of the experimental data obtained with a detection setup based on parallel plate ionization chambers (PPACs at the CERN n_TOF facility in the range from 1 eV to 10 keV. The relative cross section has been normalised to the IAEA value in the region between 7.8 and 11 eV, which is claimed as well-known. Comparison with the ENDF/B-VII evaluation and the IAEA reference file from 100 eV to 10 keV are provided.

  15. Thermodynamics of protein-ligand interactions as a reference for computational analysis: how to assess accuracy, reliability and relevance of experimental data.

    Science.gov (United States)

    Krimmer, Stefan G; Klebe, Gerhard

    2015-09-01

    For a conscientious interpretation of thermodynamic parameters (Gibbs free energy, enthalpy and entropy) obtained by isothermal titration calorimetry (ITC), it is necessary to first evaluate the experimental setup and conditions at which the data were measured. The data quality must be assessed and the precision and accuracy of the measured parameters must be estimated. This information provides the basis at which level discussion of the data is appropriate, and allows insight into the significance of comparisons with other data. The aim of this article is to provide the reader with basic understanding of the ITC technique and the experimental practices commonly applied, in order to foster an appreciation for how much measured thermodynamic parameters can deviate from ideal, error-free values. Particular attention is paid to the shape of the recorded isotherm (c-value), the influence of the applied buffer used for the reaction (protonation reactions, pH), the chosen experimental settings (temperature), impurities of protein and ligand, sources of systematic errors (solution concentration, solution activity, and device calibration) and to the applied analysis software. Furthermore, we comment on enthalpy-entropy compensation, heat capacities and van't Hoff enthalpies.

  16. A sub-1 V high-precision CMOS bandgap voltage reference

    Institute of Scientific and Technical Information of China (English)

    廖峻; 赵毅强; 耿俊峰

    2012-01-01

    A third-order,sub-1 V bandgap voltage reference design for low-power supply,high-precision applications is presented.This design uses a current-mode compensation technique and temperature-dependent resistor ratio to obtain high-order curvature compensation.The circuit was designed and fabricated by SMIC 0.18μm CMOS technology.It produces an output reference of 713.6 mV.The temperature coefficient is 3.235 pprn/℃ in the temperature range of-40 to 120 ℃,with a line regulation of 0.199 mV/V when the supply voltage varies from 0.95 to 3 V.The average current consumption of the whole circuit is 49 μA at the supply voltage of 1 V.

  17. High accuracy microwave frequency measurement based on single-drive dual-parallel Mach-Zehnder modulator

    DEFF Research Database (Denmark)

    Zhao, Ying; Pang, Xiaodan; Deng, Lei

    2011-01-01

    A novel approach for broadband microwave frequency measurement by employing a single-drive dual-parallel Mach-Zehnder modulator is proposed and experimentally demonstrated. Based on bias manipulations of the modulator, conventional frequency-to-power mapping technique is developed by performing a...... 10−3 relative error. This high accuracy frequency measurement technique is a promising candidate for high-speed electronic warfare and defense applications.......A novel approach for broadband microwave frequency measurement by employing a single-drive dual-parallel Mach-Zehnder modulator is proposed and experimentally demonstrated. Based on bias manipulations of the modulator, conventional frequency-to-power mapping technique is developed by performing...... a two-stage frequency measurement cooperating with digital signal processing. In the experiment, 10GHz measurement range is guaranteed and the average uncertainty of estimated microwave frequency is 5.4MHz, which verifies the measurement accuracy is significantly improved by achieving an unprecedented...

  18. Brief Report: Face Configuration Accuracy and Processing Speed Among Adults with High-Functioning Autism Spectrum Disorders

    OpenAIRE

    Faja, Susan; Webb, Sara Jane; Merkle, Kristen; Aylward, Elizabeth; Dawson, Geraldine

    2008-01-01

    The present study investigates the accuracy and speed of face processing employed by high-functioning adults with autism spectrum disorders (ASDs). Two behavioral experiments measured sensitivity to distances between features and face recognition when performance depended on holistic versus featural information. Results suggest adults with ASD were less accurate, but responded as quickly as controls for both tasks. In contrast to previous findings with children, adults with ASD demonstrated a...

  19. The Effect of Moderate and High-Intensity Fatigue on Groundstroke Accuracy in Expert and Non-Expert Tennis Players

    OpenAIRE

    Mark Lyons; Yahya Al-Nakeeb; Joanne Hankey; Alan Nevill

    2013-01-01

    peer-reviewed Exploring the effects of fatigue on skilled performance in tennis presents a significant challenge to the researcher with respect to ecological validity. This study examined the effects of moderate and high-intensity fatigue on groundstroke accuracy in expert and non-expert tennis players. The research also explored whether the effects of fatigue are the same regardless of gender and player's achievement motivation characteristics. 13 expert (7 male, 6 female) and 17 non-expe...

  20. A High Accuracy Pedestrian Detection System Combining a Cascade AdaBoost Detector and Random Vector Functional-Link Net

    OpenAIRE

    Zhihui Wang; Sook Yoon; Shan Juan Xie; Yu Lu; Dong Sun Park

    2014-01-01

    In pedestrian detection methods, their high accuracy detection rates are always obtained at the cost of a large amount of false pedestrians. In order to overcome this problem, the authors propose an accurate pedestrian detection system based on two machine learning methods: cascade AdaBoost detector and random vector functional-link net. During the offline training phase, the parameters of a cascade AdaBoost detector and random vector functional-link net are trained by standard dataset. These...

  1. Characterization of Monoenergetic Neutron Reference Fields with a High Resolution Diamond Detector

    CERN Document Server

    Zimbal, A; Nolte, R; Schuhmacher, H

    2009-01-01

    A novel radiation detector based on an artificial single crystal diamond was used to characterize in detail the energy distribution of neutron reference fields at the Physikalisch-Technische Bundesanstalt (PTB) and their contamination with charged particles. The monoenergetic reference fields at PTB in the neutron energy range from 1.5 MeV up to 19 MeV are generated by proton and deuteron beams impinging on solid and gas targets of tritium and deuterium. The energy of the incoming particles and the variation of the angle under which the measurement is performed produce monoenergetic reference fields with different mean energies and line shapes. In this paper we present high resolution neutron spectrometry measurements of different monoenergetic reference fields. The results are compared with calculated spectra taking into account the actual target parameters. Line structures in the order of 80 keV for a neutron energy of 9 MeV were resolved. The shift of the mean energy and the increasing of the width of the ...

  2. Towards a magnetic field stabilization at ISOLTRAP for high-accuracy mass measurements on exotic nuclides

    CERN Document Server

    Marie-Jeanne, M; Blaum, K; Djekic, S; Dworschak, M; Hager, U; Herlert, A; Nagy, S; Savreux, R; Schweikhard, L; Stahl, S; Yazidjian, C

    2008-01-01

    The field stability of a mass spectrometer plays a crucial role in the accuracy of mass measurements. In the case of mass determination of short-lived nuclides with a Penning trap, major causes of fluctuations are temperature variations in the vicinity of the trap and pressure changes in the liquid helium cryostat of the superconducting magnet. Thus systems for the temperature and pressure stabilization of the Penning trap mass spectrometer ISOLTRAP at the ISOLDE facility at CERN have been installed. A reduction of the temperature and pressure fluctuations by at least an order of magnitude down to and has been achieved, which corresponds to a relative magnetic field change of ΔB/B=2.7×10-9 and 1.1×10-10, respectively.

  3. High accuracy calculation of the hydrogen negative ion in strong magnetic fields

    Institute of Scientific and Technical Information of China (English)

    Zhao Ji-Jun; Wang Xiao-Feng; Qiao Hao-Xue

    2011-01-01

    Using a full configuration-interaction method with Hylleraas-Gaussian basis function, this paper investigates the 110+, 11(-1)+ and l1(-2)+ states of the hydrogen negative ion in strong magnetic fields. The total energies, electron detachment energies and derivatives of the total energy with respect to the magnetic field are presented as functions of magnetic field over a wide range of field strengths. Compared with the available theoretical data, the accuracy for the energies is enhanced significantly. The field regimes 3 <γ< 4 and 0.02 < 7< 0.05, in which the l1(-l)+ and l1(-2)+states start to become bound, respectively, are also determined based on the calculated electron detachment energies.

  4. Hyperbolic Method for Dispersive PDEs: Same High-Order of Accuracy for Solution, Gradient, and Hessian

    Science.gov (United States)

    Mazaheri, Alireza; Ricchiuto, Mario; Nishikawa, Hiroaki

    2016-01-01

    In this paper, we introduce a new hyperbolic first-order system for general dispersive partial differential equations (PDEs). We then extend the proposed system to general advection-diffusion-dispersion PDEs. We apply the fourth-order RD scheme of Ref. 1 to the proposed hyperbolic system, and solve time-dependent dispersive equations, including the classical two-soliton KdV and a dispersive shock case. We demonstrate that the predicted results, including the gradient and Hessian (second derivative), are in a very good agreement with the exact solutions. We then show that the RD scheme applied to the proposed system accurately captures dispersive shocks without numerical oscillations. We also verify that the solution, gradient and Hessian are predicted with equal order of accuracy.

  5. Noncontrast perfusion single-photon emission CT/CT scanning: a new test for the expedited, high-accuracy diagnosis of acute pulmonary embolism.

    Science.gov (United States)

    Lu, Yang; Lorenzoni, Alice; Fox, Josef J; Rademaker, Jürgen; Vander Els, Nicholas; Grewal, Ravinder K; Strauss, H William; Schöder, Heiko

    2014-05-01

    Standard ventilation and perfusion (V˙/Q˙) scintigraphy uses planar images for the diagnosis of pulmonary embolism (PE). To evaluate whether tomographic imaging improves the diagnostic accuracy of the procedure, we compared noncontrast perfusion single-photon emission CT (Q˙-SPECT)/CT scans with planar V˙/Q˙scans in patients at high risk for PE. Between 2006 and 2010, most patients referred for diagnosis of PE underwent both Q˙-SPECT/CT scan and planar V˙/Q˙scintigraphy. All scans were reviewed retrospectively by four observers; planar scans were read with modified Prospective Investigation of Pulmonary Embolism Diagnosis (PIOPED) II and Prospective Investigative Study of Pulmonary Embolism Diagnosis (PISA-PED) criteria. On Q˙-SPECT/CT scan, any wedge-shaped peripheral perfusion defect occupying > 50% of a segment without corresponding pulmonary parenchymal or pleural disease was considered to show PE. The final diagnosis was established with a composite reference standard that included ECG, ultrasound of lower-extremity veins, D-dimer levels, CT pulmonary angiography (when available), and clinical follow-up for at least 3 months. One hundred six patients with cancer and mean Wells score of 4.4 had sufficient follow-up; 22 patients were given a final diagnosis of PE, and 84 patients were given a final diagnosis of no PE. According to PIOPED II, 13 studies were graded as intermediate probability. Sensitivity and specificity for PE were 50% and 98%, respectively, based on PIOPED II criteria; 86% and 93%, respectively, based on PISA-PED criteria; and 91% and 94%, respectively, based on Q˙-SPECT/CT scan. Seventy-six patients had additional relevant findings on the CT image of the Q˙-SPECT/CT scan. Noncontrast Q˙-SPECT/CT imaging has a higher accuracy than planar V˙/Q˙imaging based on PIOPED II criteria in patients with cancer and a high risk for PE.

  6. Evaluation of Heart Rate Assessment Timing, Communication, Accuracy, and Clinical Decision-Making during High Fidelity Simulation of Neonatal Resuscitation

    Directory of Open Access Journals (Sweden)

    Win Boon

    2014-01-01

    Full Text Available Objective. Accurate heart rate (HR determination during neonatal resuscitation (NR informs subsequent NR actions. This study’s objective was to evaluate HR determination timeliness, communication, and accuracy during high fidelity NR simulations that house officers completed during neonatal intensive care unit (NICU rotations. Methods. In 2010, house officers in NICU rotations completed high fidelity NR simulation. We reviewed 80 house officers’ videotaped performance on their initial high fidelity simulation session, prior to training and performance debriefing. We calculated the proportion of cases congruent with NR guidelines, using chi square analysis to evaluate performance across HR ranges relevant to NR decision-making: <60, 60–99, and ≥100 beats per minute (bpm. Results. 87% used umbilical cord palpation, 57% initiated HR assessment within 30 seconds, 70% were accurate, and 74% were communicated appropriately. HR determination accuracy varied significantly across HR ranges, with 87%, 57%, and 68% for HR <60, 60–99, and ≥100 bpm, respectively (P<0.001. Conclusions. Timeliness, communication, and accuracy of house officers’ HR determination are suboptimal, particularly for HR 60–100 bpm, which might lead to inappropriate decision-making and NR care. Training implications include emphasizing more accurate HR determination methods, better communication, and improved HR interpretation during NR.

  7. Efficient and accurate local single reference correlation methods for high-spin open-shell molecules using pair natural orbitals

    Science.gov (United States)

    Hansen, Andreas; Liakos, Dimitrios G.; Neese, Frank

    2011-12-01

    A production level implementation of the high-spin open-shell (spin unrestricted) single reference coupled pair, quadratic configuration interaction and coupled cluster methods with up to doubly excited determinants in the framework of the local pair natural orbital (LPNO) concept is reported. This work is an extension of the closed-shell LPNO methods developed earlier [F. Neese, F. Wennmohs, and A. Hansen, J. Chem. Phys. 130, 114108 (2009), 10.1063/1.3086717; F. Neese, A. Hansen, and D. G. Liakos, J. Chem. Phys. 131, 064103 (2009), 10.1063/1.3173827]. The internal space is spanned by localized orbitals, while the external space for each electron pair is represented by a truncated PNO expansion. The laborious integral transformation associated with the large number of PNOs becomes feasible through the extensive use of density fitting (resolution of the identity (RI)) techniques. Technical complications arising for the open-shell case and the use of quasi-restricted orbitals for the construction of the reference determinant are discussed in detail. As in the closed-shell case, only three cutoff parameters control the average number of PNOs per electron pair, the size of the significant pair list, and the number of contributing auxiliary basis functions per PNO. The chosen threshold default values ensure robustness and the results of the parent canonical methods are reproduced to high accuracy. Comprehensive numerical tests on absolute and relative energies as well as timings consistently show that the outstanding performance of the LPNO methods carries over to the open-shell case with minor modifications. Finally, hyperfine couplings calculated with the variational LPNO-CEPA/1 method, for which a well-defined expectation value type density exists, indicate the great potential of the LPNO approach for the efficient calculation of molecular properties.

  8. Very high precision and accuracy analysis of triple isotopic ratios of water. A critical instrumentation comparison study.

    Science.gov (United States)

    Gkinis, Vasileios; Holme, Christian; Morris, Valerie; Thayer, Abigail Grace; Vaughn, Bruce; Kjaer, Helle Astrid; Vallelonga, Paul; Simonsen, Marius; Jensen, Camilla Marie; Svensson, Anders; Maffrezzoli, Niccolo; Vinther, Bo; Dallmayr, Remi

    2017-04-01

    We present a performance comparison study between two state of the art Cavity Ring Down Spectrometers (Picarro L2310-i, L2140-i). The comparison took place during the Continuous Flow Analysis (CFA) campaign for the measurement of the Renland ice core, over a period of three months. Instant and complete vaporisation of the ice core melt stream, as well as of in-house water reference materials is achieved by accurate control of microflows of liquid into a homemade calibration system by following simple principles of the Hagen-Poiseuille law. Both instruments share the same vaporisation unit in a configuration that minimises sample preparation discrepancies between the two analyses. We describe our SMOW-SLAP calibration and measurement protocols for such a CFA application and present quality control metrics acquired during the full period of the campaign on a daily basis. The results indicate an unprecedented performance for all 3 isotopic ratios (δ2H, δ17O, δ18O ) in terms of precision, accuracy and resolution. We also comment on the precision and accuracy of the second order excess parameters of HD16O and H217O over H218O (Dxs, Δ17O ). To our knowledge these are the first reported CFA measurements at this level of precision and accuracy for all three isotopic ratios. Differences on the performance of the two instruments are carefully assessed during the measurement and reported here. Our quality control protocols extend to the area of low water mixing ratios, a regime in which often atmospheric vapour measurements take place and Cavity Ring Down Analysers show a poorer performance due to the lower signal to noise ratios. We address such issues and propose calibration protocols from which water vapour isotopic analyses can benefit from.

  9. High-accuracy CFD prediction methods for fluid and structure temperature fluctuations at T-junction for thermal fatigue evaluation

    Energy Technology Data Exchange (ETDEWEB)

    Qian, Shaoxiang, E-mail: qian.shaoxiang@jgc.com [EN Technology Center, Process Technology Division, JGC Corporation, 2-3-1 Minato Mirai, Nishi-ku, Yokohama 220-6001 (Japan); Kanamaru, Shinichiro [EN Technology Center, Process Technology Division, JGC Corporation, 2-3-1 Minato Mirai, Nishi-ku, Yokohama 220-6001 (Japan); Kasahara, Naoto [Nuclear Engineering and Management, School of Engineering, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8656 (Japan)

    2015-07-15

    Highlights: • Numerical methods for accurate prediction of thermal loading were proposed. • Predicted fluid temperature fluctuation (FTF) intensity is close to the experiment. • Predicted structure temperature fluctuation (STF) range is close to the experiment. • Predicted peak frequencies of FTF and STF also agree well with the experiment. • CFD results show the proposed numerical methods are of sufficiently high accuracy. - Abstract: Temperature fluctuations generated by the mixing of hot and cold fluids at a T-junction, which is widely used in nuclear power and process plants, can cause thermal fatigue failure. The conventional methods for evaluating thermal fatigue tend to provide insufficient accuracy, because they were developed based on limited experimental data and a simplified one-dimensional finite element analysis (FEA). CFD/FEA coupling analysis is expected as a useful tool for the more accurate evaluation of thermal fatigue. The present paper aims to verify the accuracy of proposed numerical methods of simulating fluid and structure temperature fluctuations at a T-junction for thermal fatigue evaluation. The dynamic Smagorinsky model (DSM) is used for large eddy simulation (LES) sub-grid scale (SGS) turbulence model, and a hybrid scheme (HS) is adopted for the calculation of convective terms in the governing equations. Also, heat transfer between fluid and structure is calculated directly through thermal conduction by creating a mesh with near wall resolution (NWR) by allocating grid points within the thermal boundary sub-layer. The simulation results show that the distribution of fluid temperature fluctuation intensity and the range of structure temperature fluctuation are remarkably close to the experimental results. Moreover, the peak frequencies of power spectrum density (PSD) of both fluid and structure temperature fluctuations also agree well with the experimental results. Therefore, the numerical methods used in the present paper are

  10. Image quality, radiation dose, and diagnostic accuracy of prospectively ECG-triggered high-pitch coronary CT angiography at 70 kVp in a clinical setting: comparison with invasive coronary angiography

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Long Jiang; Qi, Li; Zhou, Chang Sheng; Zhao, Yan E.; Li, Xie; Lu, Guang Ming [Jinling Hospital, Medical School of Nanjing University, Department of Medical Imaging, Nanjing, Jiangsu (China); Wang, Yining; Cao, Jian; Jin, Zhengyu [Peking Union Medical College Hospital, Department of Radiology, Beijing (China); Schoepf, U.J. [Jinling Hospital, Medical School of Nanjing University, Department of Medical Imaging, Nanjing, Jiangsu (China); Medical University of South Carolina, Division of Cardiovascular Imaging, Charleston, SC (United States); Meinel, Felix G. [Medical University of South Carolina, Division of Cardiovascular Imaging, Charleston, SC (United States); Ludwig-Maximilians-University Hospital, Institute for Clinical Radiology, Munich (Germany); Bayer, Richard R. [Medical University of South Carolina, Division of Cardiovascular Imaging, Charleston, SC (United States); Gong, Jian Bin [Jinling Hospital, Medical School of Nanjing University, Department of Cardiology, Nanjing, Jiangsu (China)

    2016-03-15

    To investigate image quality, radiation dose, and diagnostic performance of prospectively ECG-triggered high-pitch coronary CT angiography (CCTA) at 70 kVp compared to invasive coronary angiography (ICA) as reference standard. Forty-three patients underwent prospectively ECG-triggered high-pitch CCTA at 70 kVp using 30 cc (11 g iodine) contrast medium and ICA. Subjective and objective image quality was evaluated for each CCTA study. CCTA performance for diagnosing ≥50 % stenosis was assessed. Results were stratified according to heart rate (HR), body mass index (BMI), Agatston score, and image quality. At CCTA, 94.3 % (500/530) of coronary segments were of diagnostic quality. Using ICA as reference standard, sensitivity and accuracy were 100 % and 93.0 % on a per-patient basis. Per-vessel and per-segment performances were 92.2 % and 89.5 %; 79.5 % and 88.3 %, respectively. No differences were found in diagnostic accuracy between different HR, BMI, and calcification subgroups (all P > 0.05) on a per-patient basis. However, low image quality reduced diagnostic accuracy on a per-patient, per-vessel and per-segment basis (all P < 0.05). The mean effective radiation dose was 0.2 ± 0.0 mSv. Our presented protocol results in an effective radiation dose of 0.2 mSv and high diagnostic accuracy for stenosis detection in a selected, non-obese population. (orig.)

  11. Restoring ecological integrity in highly regulated rivers: the role of baseline data and analytical references.

    Science.gov (United States)

    Downs, Peter W; Singer, Maia S; Orr, Bruce K; Diggory, Zooey E; Church, Tamara C; Stella, J C

    2011-10-01

    The goal of restoring ecological integrity in rivers is frequently accompanied by an assumption that a comparative reference reach can be identified to represent minimally impaired conditions. However, in many regulated rivers, no credible historical, morphological or process-based reference reach exists. Resilient restoration designs should instead be framed around naturalization, using multiple analytical references derived from empirically-calibrated field- and model-based techniques to develop an integrated ecological reference condition. This requires baseline data which are rarely collected despite increasing evidence for systematic deficiencies in restoration practice. We illustrate the utility of baseline data collection in restoration planning for the highly fragmented and regulated lower Merced River, California, USA. The restoration design was developed using various baseline data surveys, monitoring, and modeling within an adaptive management framework. Baseline data assisted in transforming conceptual models of ecosystem function into specific restoration challenges, defining analytical references of the expected relationships among ecological parameters required for restoration, and specifying performance criteria for post-project monitoring and evaluation. In this way the study is an example of process-based morphological restoration designed to prompt recovery of ecosystem processes and resilience. For the Merced River, we illustrate that project-specific baseline data collection is a necessary precursor in developing performance-based restoration designs and addressing scale-related uncertainties, such as whether periodic gravel augmentation will sustain bed recovery and whether piecemeal efforts will improve ecological integrity. Given the numerous impediments to full, historical, restoration in many river systems, it seems apparent that projects of naturalization are a critical step in reducing the deleterious impacts of fragmented rivers

  12. High-accuracy optical clock based on the octupole transition in 171Yb+

    CERN Document Server

    Huntemann, N; Lipphardt, B; Weyers, S; Tamm, Chr; Peik, E

    2011-01-01

    We experimentally investigate an optical frequency standard based on the 467 nm (642 THz) electric-octupole reference transition 2S1/2(F=0) -> F7/2(F=3) in a single trapped 171Yb+ ion. The extraordinary features of this transition result from the long natural lifetime and from the 4f136s2 configuration of the upper state. The electric quadrupole moment of the 2F7/2 state is measured as -0.041(5) e(a0)^2, where e is the elementary charge and a0 the Bohr radius. We also obtain information on the differential scalar and tensorial components of the static polarizability and of the probe light induced ac Stark shift of the octupole transition. With a real-time extrapolation scheme that eliminates this shift, the unperturbed transition frequency is realized with a fractional uncertainty of 7.1x10^(-17). The frequency is measured as 642 121 496 772 645.15(52) Hz with the uncertainty essentially determined by the employed caesium fountain reference.

  13. Adaptive switching frequency buck DC—DC converter with high-accuracy on-chip current sensor

    Science.gov (United States)

    Jinguang, Jiang; Fei, Huang; Zhihui, Xiong

    2015-05-01

    A current-mode PWM buck DC—DC converter is proposed. With the high-accuracy on-chip current sensor, the switching frequency can be selected automatically according to load requirements. This method improves efficiency and obtains an excellent transient response. The high accuracy of the current sensor is achieved by a simple switch technique without an amplifier. This has the direct benefit of reducing power dissipation and die size. Additionally, a novel soft-start circuit is presented to avoid the inrush current at the starting up state. Finally, this DC—DC converter is fabricated with the 0.5 μm standard CMOS process. The chip occupies 3.38 mm2. The accuracy of the proposed current sensor can achieve 99.5% @ 200 mA. Experimental results show that the peak efficiency is 91.8%. The input voltage ranges from 5 to 18 V, while a 2 A load current can be obtained. Project supported by the National Natural Science Foundation of China (No. 41274047), the Natural Science Foundation of Jiangsu Province (No. BK2012639), the Science and Technology Enterprises in Jiangsu Province Technology Innovation Fund (No. BC2012121), and the Changzhou Science and Technology Support (Industrial) Project (No. CE20120074).

  14. An anti-disturbance high-precision alignment for distributed POS based on inertial reference frame

    Science.gov (United States)

    Bai, Lijian; Wang, Yue

    2017-03-01

    The distributed POS is playing an important role in the ultra-high resolution aerial survey and remote sensing system, and can accurately provide time-spatial reference information for various imaging sensors. However, the distributed POS faces a special problem that the flexible arms used to connect the inertial measurement units (IMUs) would deteriorate the phenomenon that external disturbance leads to serious alignment errors. In order to improve the alignment precision of distributed POS in external disturbance, an anti-disturbance coarse alignment based on inertial reference frame is proposed. This method is developed mainly based on the structure of non-collinear vectors, which are constructed by a velocity vector determined by gravity vector integration. The disturbed acceleration and rotation is decreased a lot by the integral operation in the proposed method. Finally, the experiments were carried out and verified the validity of the proposed method.

  15. A stabilized chip-scale Kerr frequency comb via a high-Q reference photonic microresonator

    CERN Document Server

    Lim, Jinkang; Vinod, Abhinav K; Mortazavian, Parastou; Yu, Mingbin; Kwong, Dim-Lee; Savchenkov, Anatoliy A; Matsko, Andrey B; Maleki, Lute; Wong, Chee Wei

    2016-01-01

    We stabilize a chip-scale Si3N4 phase-locked Kerr frequency comb via locking the pump laser to an independent stable high-Q reference microresonator and locking the comb spacing to an external microwave oscillator. In this comb, the pump laser shift induces negligible impact on the comb spacing change. This scheme is a step towards miniaturization of the stabilized Kerr comb system as the microresonator reference can potentially be integrated on-chip. Fractional instability of the optical harmonics of the stabilized comb is limited by the microwave oscillator used for comb spacing lock below 1 s averaging time and coincides with the pump laser drift in the long term.

  16. High density wireless EEG prototype: Design and evaluation against reference equipment.

    Science.gov (United States)

    Rossi, Stefano; Patki, Shrishail; Passoni, Marco; Perko, Hannes; Gritsch, Gerhard; Ossenblok, Pauly; Yazicioglu, Refet Firat

    2014-01-01

    A high density wireless electroencephalographic (EEG) platform has been designed. It is able to record up to 64 EEG channels with electrode to tissue impedance (ETI) monitoring. The analog front-end is based on two kinds of low power ASICs implementing the active electrodes and the amplifier. A power efficient compression algorithm enables the use of continuous wireless transmission of data through Bluetooth for real-time monitoring with an overall power consumption of about 350 mW. EEG acquisitions on five subjects (one healthy subject and four patients suffering from epilepsy) have been recorded in parallel with a reference system commonly used in clinical practice and data of the wireless prototype and reference system have been processed with an automatic tool for seizure detection and localization. The false alarm rates (0.1-0.5 events per hour) are comparable between the two system and wireless prototype also detected the seizure correctly and allowed its localization.

  17. Gravity Compensation Methods for High-Accuracy INS%高精度惯性导航系统重力补偿方法

    Institute of Scientific and Technical Information of China (English)

    陆志东; 王晶

    2016-01-01

    重力扰动是高精度惯性导航系统的一项重要误差源,重力补偿是降低惯性导航系统误差的一项关键技术。通过基于对确定性模型、数据及外部辅助3种重力补偿方法的分析和研究,总结得出了各补偿方法的研究方向以及适用范围,对进一步提高我国未来更高精度惯性导航系统的导航精度具有指导意义,并提供了方法上的参考。%Gravity disturbance is an important error source of high-accuracy inertial navigation system(INS). Gravity compensation is a critical technology to reduce error of INS. After analysing and researching deterministic model,data and external assist gravity compensation methods,research area and range of application were summarized. It can provide guidance and reference to improve INS’s navigation accuracy.

  18. High Accuracy Passive Magnetic Field-Based Localization for Feedback Control Using Principal Component Analysis

    Directory of Open Access Journals (Sweden)

    Shaohui Foong

    2016-08-01

    Full Text Available In this paper, a novel magnetic field-based sensing system employing statistically optimized concurrent multiple sensor outputs for precise field-position association and localization is presented. This method capitalizes on the independence between simultaneous spatial field measurements at multiple locations to induce unique correspondences between field and position. This single-source-multi-sensor configuration is able to achieve accurate and precise localization and tracking of translational motion without contact over large travel distances for feedback control. Principal component analysis (PCA is used as a pseudo-linear filter to optimally reduce the dimensions of the multi-sensor output space for computationally efficient field-position mapping with artificial neural networks (ANNs. Numerical simulations are employed to investigate the effects of geometric parameters and Gaussian noise corruption on PCA assisted ANN mapping performance. Using a 9-sensor network, the sensing accuracy and closed-loop tracking performance of the proposed optimal field-based sensing system is experimentally evaluated on a linear actuator with a significantly more expensive optical encoder as a comparison.

  19. High-resolution CT of transplanted teeth: imaging technique and measurement accuracy

    Energy Technology Data Exchange (ETDEWEB)

    Gahleitner, Andre [Medical University of Vienna, Department of Radiology/Osteology and MR, Vienna (Austria); Medical University Vienna, Department of Radiology, Vienna (Austria); Kuchler, Ulrike; Heschl, Janina; Watzek, Georg [Medical University of Vienna, Department of Oral Surgery, Vienna (Austria); Homolka, Peter [Medical University of Vienna, Center for Biomedical Engineering and Physics, Vienna (Austria); Imhof, Herwig [Medical University of Vienna, Department of Radiology/Osteology and MR, Vienna (Austria)

    2008-12-15

    The aim of this study was to determine the accuracy of crown diameter measurements by dental CT as a tool for preoperative diagnosis before tooth transplantations. Fifty-eight patients underwent clinically indicated dental CT. The diameter of the crowns were measured by CT using a standard protocol (1.5-mm slice thickness, 1-mm table feed, 120 kV, 25-75 mA/s, 2-s scan time/slice, 512 matrix) and a standard dental software package. Postoperatively, the same distances were clinically measured using a sliding gauge. The degree of the deviation between CT measurements and clinical measurements was in the sub-millimeter range. According to the regression analysis, the correlation coefficient equals 0.98 and 0.97, indicating a strong relationship between the CT and the manual measurement of the crown diameter in the bucco-lingual and the mesio-distal direction. The mean deviation of CT measurements with regard to the bucco-lingual diameter of the crown was +0.08 mm (SD: {+-}0.38 mm). For the mesio-distal diameter, the mean deviation of CT measurements was -0.24 mm (SD: {+-}0.53 mm). These results demonstrate that dental CT promises to be a valuable tool for the evaluation of the potential and optimal size and site for tooth transplantations. (orig.)

  20. Novel speech signal processing algorithms for high-accuracy classification of Parkinson's disease.

    Science.gov (United States)

    Tsanas, Athanasios; Little, Max A; McSharry, Patrick E; Spielman, Jennifer; Ramig, Lorraine O

    2012-05-01

    There has been considerable recent research into the connection between Parkinson's disease (PD) and speech impairment. Recently, a wide range of speech signal processing algorithms (dysphonia measures) aiming to predict PD symptom severity using speech signals have been introduced. In this paper, we test how accurately these novel algorithms can be used to discriminate PD subjects from healthy controls. In total, we compute 132 dysphonia measures from sustained vowels. Then, we select four parsimonious subsets of these dysphonia measures using four feature selection algorithms, and map these feature subsets to a binary classification response using two statistical classifiers: random forests and support vector machines. We use an existing database consisting of 263 samples from 43 subjects, and demonstrate that these new dysphonia measures can outperform state-of-the-art results, reaching almost 99% overall classification accuracy using only ten dysphonia features. We find that some of the recently proposed dysphonia measures complement existing algorithms in maximizing the ability of the classifiers to discriminate healthy controls from PD subjects. We see these results as an important step toward noninvasive diagnostic decision support in PD.

  1. High Accuracy Passive Magnetic Field-Based Localization for Feedback Control Using Principal Component Analysis

    Science.gov (United States)

    Foong, Shaohui; Sun, Zhenglong

    2016-01-01

    In this paper, a novel magnetic field-based sensing system employing statistically optimized concurrent multiple sensor outputs for precise field-position association and localization is presented. This method capitalizes on the independence between simultaneous spatial field measurements at multiple locations to induce unique correspondences between field and position. This single-source-multi-sensor configuration is able to achieve accurate and precise localization and tracking of translational motion without contact over large travel distances for feedback control. Principal component analysis (PCA) is used as a pseudo-linear filter to optimally reduce the dimensions of the multi-sensor output space for computationally efficient field-position mapping with artificial neural networks (ANNs). Numerical simulations are employed to investigate the effects of geometric parameters and Gaussian noise corruption on PCA assisted ANN mapping performance. Using a 9-sensor network, the sensing accuracy and closed-loop tracking performance of the proposed optimal field-based sensing system is experimentally evaluated on a linear actuator with a significantly more expensive optical encoder as a comparison. PMID:27529253

  2. Designing a high accuracy 3D auto stereoscopic eye tracking display, using a common LCD monitor

    Science.gov (United States)

    Taherkhani, Reza; Kia, Mohammad

    2012-09-01

    This paper describes the design and building of a low cost and practical stereoscopic display that does not need to wear special glasses, and uses eye tracking to give a large degree of freedom to viewer (or viewer's) movement while displaying the minimum amount of information. The parallax barrier technique is employed to turn a LCD into an auto-stereoscopic display. The stereo image pair is screened on the usual liquid crystal display simultaneously but in different columns of pixels. Controlling of the display in red-green-blue sub pixels increases the accuracy of light projecting direction to less than 2 degrees without losing too much LCD's resolution and an eye-tracking system determines the correct angle to project the images along the viewer's eye pupils and an image processing system puts the 3D images data in correct R-G-B sub pixels. 1.6 degree of light direction controlling achieved in practice. The 3D monitor is just made by applying some simple optical materials on a usual LCD display with normal resolution. [Figure not available: see fulltext.

  3. High Accuracy Passive Magnetic Field-Based Localization for Feedback Control Using Principal Component Analysis.

    Science.gov (United States)

    Foong, Shaohui; Sun, Zhenglong

    2016-08-12

    In this paper, a novel magnetic field-based sensing system employing statistically optimized concurrent multiple sensor outputs for precise field-position association and localization is presented. This method capitalizes on the independence between simultaneous spatial field measurements at multiple locations to induce unique correspondences between field and position. This single-source-multi-sensor configuration is able to achieve accurate and precise localization and tracking of translational motion without contact over large travel distances for feedback control. Principal component analysis (PCA) is used as a pseudo-linear filter to optimally reduce the dimensions of the multi-sensor output space for computationally efficient field-position mapping with artificial neural networks (ANNs). Numerical simulations are employed to investigate the effects of geometric parameters and Gaussian noise corruption on PCA assisted ANN mapping performance. Using a 9-sensor network, the sensing accuracy and closed-loop tracking performance of the proposed optimal field-based sensing system is experimentally evaluated on a linear actuator with a significantly more expensive optical encoder as a comparison.

  4. Determination of micro-litre volumes with high accuracy for flow cytometric blood cell counting

    Science.gov (United States)

    Reitz, S.; Kummrow, A.; Kammel, M.; Neukammer, J.

    2010-07-01

    We have gravimetrically calibrated the volumes dispensed by 1 mL syringes in the range between 1 µL and 100 µL using ultra-pure water. Protocols are based on series of consecutive difference measurements of masses in order to precisely compensate for evaporation, being the most important disturbing quantity. We determined expanded uncertainties of volume measurements for glass syringes of typically 0.2% (expansion factor 2) when dispensing volumes of 10 µL. For polypropylene syringes, selected with respect to the manufacturer, expanded uncertainties of 0.25% (expansion factor 2) were observed. Calibrated syringes were applied for measuring concentrations of blood cells in a flow cytometer demonstrating the capability to determine reference measurement values. Since the direct interaction of blood cells and syringe walls may lead to cell adhesion, glass syringes as well as (disposable) polypropylene syringes were calibrated.

  5. Reference Standardization for Mass Spectrometry and High-resolution Metabolomics Applications to Exposome Research.

    Science.gov (United States)

    Go, Young-Mi; Walker, Douglas I; Liang, Yongliang; Uppal, Karan; Soltow, Quinlyn A; Tran, ViLinh; Strobel, Frederick; Quyyumi, Arshed A; Ziegler, Thomas R; Pennell, Kurt D; Miller, Gary W; Jones, Dean P

    2015-12-01

    The exposome is the cumulative measure of environmental influences and associated biological responses throughout the lifespan, including exposures from the environment, diet, behavior, and endogenous processes. A major challenge for exposome research lies in the development of robust and affordable analytic procedures to measure the broad range of exposures and associated biologic impacts occurring over a lifetime. Biomonitoring is an established approach to evaluate internal body burden of environmental exposures, but use of biomonitoring for exposome research is often limited by the high costs associated with quantification of individual chemicals. High-resolution metabolomics (HRM) uses ultra-high resolution mass spectrometry with minimal sample preparation to support high-throughput relative quantification of thousands of environmental, dietary, and microbial chemicals. HRM also measures metabolites in most endogenous metabolic pathways, thereby providing simultaneous measurement of biologic responses to environmental exposures. The present research examined quantification strategies to enhance the usefulness of HRM data for cumulative exposome research. The results provide a simple reference standardization protocol in which individual chemical concentrations in unknown samples are estimated by comparison to a concurrently analyzed, pooled reference sample with known chemical concentrations. The approach was tested using blinded analyses of amino acids in human samples and was found to be comparable to independent laboratory results based on surrogate standardization or internal standardization. Quantification was reproducible over a 13-month period and extrapolated to thousands of chemicals. The results show that reference standardization protocol provides an effective strategy that will enhance data collection for cumulative exposome research. In principle, the approach can be extended to other types of mass spectrometry and other analytical methods.

  6. [Improved patient repositioning accuracy by integrating an additional jaw fixation into a high precision face mask system in stereotactic radiotherapy of the head].

    Science.gov (United States)

    Lopatta, Eric; Liesenfeld, Susie-Maria; Bank, Priska; Wurm, Reinhard; Günther, Robert; Wiezorek, Tilo; Wendt, Thomas G

    2003-08-01

    For high precision radiotherapy of the neurocranium a precise, reproducible positioning technique is the basic prerequisite. The aim of this study was to assess the influence of a modification of the commercially available stereotactical BrainLab-head mask system on accuracy in patient positioning during fractionated radiotherapy. 29 patients were treated with stereotactic radiotherapy of the head. Immobilization was provided by a two layer thermoplastic mask system (BrainLab). 18 of these patients received an additional custom made fixation either of the upper jaw (OKF) or of the mandibula (UKF). The positioning accuracy was assessed by measurements of the shifting of anatomical landmarks in relation to the rigid mask system on biplanar simulator films using a digital imaging system. Before each measurement a fine adjustment of the simulator to an optical ring system was performed. The reference radiographs were done just before CT-planning. During a 2-7 weeks lasting course of radiotherapy displacement measurements in relation to the reference images for all three dimensions (z, y and x) were done once a week. In 29 patients 844 measurements were analyzed. An additional jaw fixation improves the reproducibility of patient positioning significantly in all three spatial dimensions. The standard deviation in lateral direction (x) was 0.6 mm with jaw fixation vs. 0.7 mm without jaw fixation (p jaw fixation can be acquired. The variability of positioning can be reduced especially in the z-direction. A further reduction of the safety margin around the target volume--especially in benign tumors--is possible by improved fixation technique.

  7. Survey of processes for high temperature-high pressure gas purification. [52 references

    Energy Technology Data Exchange (ETDEWEB)

    Meyer, J.P.; Edwards, M.S.

    1978-11-01

    In order to ensure the optimum operating efficiency of a combined-cycle electric power generating system, it is necessary to provide gas treatment processes capable of operating at high temperatures (> 1000/sup 0/F) and high pressures (> 10 atm (absolute)). These systems will be required to condition the inlet stream to the gas turbine to suitable levels of gas purity (removal of particulate matter, sulfur, nitrogen, and alkali metal compounds) to be compatible with both environmental and machine constraints. A survey of the available and developmental processes for the removal of these various contaminant materials has been conducted. Based on the data obtained from a variety of sources, an analysis has been performed to evaluate the performance of a number of potential cleanup processes in view of the overall system needs. The results indicate that commercially available, reliable, and economically competitive hot-gas cleanup systems (for the removal of H/sub 2/S, particulate matter, alkali, and nitrogen compounds) capable of conditioning raw product gas to the levels required for turbine use will not be available for some time.

  8. ISPA - a high accuracy X-ray and gamma camera Exhibition LEPFest 2000

    CERN Multimedia

    2000-01-01

    ISPA offers ... Ten times better resolution than Anger cameras High efficiency single gamma counting Noise reduction by sensitivity to gamma energy ...for Single Photon Emission Computed Tomography (SPECT)

  9. Expression of CRM1 and CDK5 shows high prognostic accuracy for gastric cancer

    Science.gov (United States)

    Sun, Yu-Qin; Xie, Jian-Wei; Xie, Hong-Teng; Chen, Peng-Chen; Zhang, Xiu-Li; Zheng, Chao-Hui; Li, Ping; Wang, Jia-Bin; Lin, Jian-Xian; Cao, Long-Long; Huang, Chang-Ming; Lin, Yao

    2017-01-01

    AIM To evaluate the predictive value of the expression of chromosomal maintenance (CRM)1 and cyclin-dependent kinase (CDK)5 in gastric cancer (GC) patients after gastrectomy. METHODS A total of 240 GC patients who received standard gastrectomy were enrolled in the study. The expression level of CRM1 and CDK5 was detected by immunohistochemistry. The correlations between CRM1 and CDK5 expression and clinicopathological factors were explored. Univariate and multivariate survival analyses were used to identify prognostic factors for GC. Receiver operating characteristic analysis was used to compare the accuracy of the prediction of clinical outcome by the parameters. RESULTS The expression of CRM1 was significantly related to size of primary tumor (P = 0.005), Borrmann type (P = 0.006), degree of differentiation (P = 0.004), depth of invasion (P = 0.008), lymph node metastasis (P = 0.013), TNM stage (P = 0.002) and distant metastasis (P = 0.015). The expression of CDK5 was significantly related to sex (P = 0.048) and Lauren’s classification (P = 0.011). Multivariate Cox regression analysis identified that CRM1 and CDK5 co-expression status was an independent prognostic factor for overall survival (OS) of patients with GC. Integration of CRM1 and CDK5 expression could provide additional prognostic value for OS compared with CRM1 or CDK5 expression alone (P = 0.001). CONCLUSION CRM1 and CDK5 co-expression was an independent prognostic factors for GC. Combined CRM1 and CDK5 expression could provide a prognostic model for OS of GC. PMID:28373767

  10. A novel low-voltage high precision current reference based on subthreshold MOSFETs

    Institute of Scientific and Technical Information of China (English)

    YU Guo-yi; ZOU Xue-cheng

    2007-01-01

    A novel topology low-voltage high precision current reference based on subthreshold Metal-Oxide-Semiconductor Field Effect Transistors (MOSFETs) is presented. The circuit achieves a temperature-independent reference current by a proper combination current of two first-order temperature-compensation current References , which exploit the temperature characteristics of integrated poly2 resistors and the Ⅰ- Ⅴ transconductance characteristics of MOSFET operating in the subthreshold region. The circuit, designed with the 1st silicon 0.35 μm standard CMOS logic process technology, exhibits a stable current of about 2.25 μA with much low temperature coefficient of 3 ×10-4 μA/℃ in the temperature range of -40~150 ℃ at 1 V supply voltage, and also achieves a better power supply rejection ratio (PSRR) over a broad frequency. The PSRR is about -78 dB at DC and remains -42dB at the frequency higher than 10 MHz. The maximal process error is about 6.7% based on the Monte Carlo simulation. So it has good process compatibility.

  11. Influence of measuring algorithm on shape accuracy in the compensating turning of high gradient thin-wall parts

    Science.gov (United States)

    Wang, Tao; Wang, Guilin; Zhu, Dengchao; Li, Shengyi

    2015-02-01

    In order to meet the requirement of aerodynamics, the infrared domes or windows with conformal and thin-wall structure becomes the development trend of high-speed aircrafts in the future. But these parts usually have low stiffness, the cutting force will change along with the axial position, and it is very difficult to meet the requirement of shape accuracy by single machining. Therefore, on-machine measurement and compensating turning are used to control the shape errors caused by the fluctuation of cutting force and the change of stiffness. In this paper, on the basis of ultra precision diamond lathe, a contact measuring system with five DOFs is developed to achieve on-machine measurement of conformal thin-wall parts with high accuracy. According to high gradient surface, the optimizing algorithm is designed on the distribution of measuring points by using the data screening method. The influence rule of sampling frequency is analyzed on measuring errors, the best sampling frequency is found out based on planning algorithm, the effect of environmental factors and the fitting errors are controlled within lower range, and the measuring accuracy of conformal dome is greatly improved in the process of on-machine measurement. According to MgF2 conformal dome with high gradient, the compensating turning is implemented by using the designed on-machine measuring algorithm. The shape error is less than PV 0.8μm, greatly superior compared with PV 3μm before compensating turning, which verifies the correctness of measuring algorithm.

  12. High-accuracy measurement of ship velocities by DGPS; DGPS ni yoru sensoku keisoku no koseidoka ni tsuite

    Energy Technology Data Exchange (ETDEWEB)

    Yamaguchi, S.; Koterayama, W. [Kyushu Univ., Fukuoka (Japan). Research Inst. for Applied Mechanics

    1996-04-10

    The differential global positioning system (DGPS) can eliminate most of errors in ship velocity measurement by GPS positioning alone. Through two rounds of marine observations by towing an observation robot in summer 1995, the authors attempted high-accuracy measurement of ship velocities by DGPS, and also carried out both positioning by GPS alone and measurement using the bottom track of ADCP (acoustic Doppler current profiler). In this paper, the results obtained by these measurement methods were examined through comparison among them, and the accuracy of the measured ship velocities was considered. In DGPS measurement, both translocation method and interference positioning method were used. ADCP mounted on the observation robot allowed measurement of the velocity of current meter itself by its bottom track in shallow sea areas less than 350m. As the result of these marine observations, it was confirmed that the accuracy equivalent to that of direct measurement by bottom track is possible to be obtained by DGPS. 3 refs., 5 figs., 1 tab.

  13. High-accuracy current generation in the nanoampere regime from a silicon single-trap electron pump

    Science.gov (United States)

    Yamahata, Gento; Giblin, Stephen P.; Kataoka, Masaya; Karasawa, Takeshi; Fujiwara, Akira

    2017-01-01

    A gigahertz single-electron (SE) pump with a semiconductor charge island is promising for a future quantum current standard. However, high-accuracy current in the nanoampere regime is still difficult to achieve because the performance of SE pumps tends to degrade significantly at frequencies exceeding 1 GHz. Here, we demonstrate robust SE pumping via a single-trap level in silicon up to 7.4 GHz, at which the pumping current exceeds 1 nA. An accuracy test with an uncertainty of about one part per million (ppm) reveals that the pumping current deviates from the ideal value by only about 20 ppm at the flattest part of the current plateau. This value is two orders of magnitude better than the best one reported in the nanoampere regime. In addition, the pumping accuracy is almost unchanged up to 7.4 GHz, probably due to strong electron confinement in the trap. These results indicate that trap-mediated SE pumping is promising for achieving the practical operation of the quantum current standard. PMID:28322339

  14. High-accuracy optical clock based on the octupole transition in 171Yb+.

    Science.gov (United States)

    Huntemann, N; Okhapkin, M; Lipphardt, B; Weyers, S; Tamm, Chr; Peik, E

    2012-03-02

    We experimentally investigate an optical frequency standard based on the 467 nm (642 THz) electric-octupole reference transition (2)S(1/2)(F=0)→(2)F(7/2)(F=3) in a single trapped (171)Yb(+) ion. The extraordinary features of this transition result from the long natural lifetime and from the 4f(13)6s(2) configuration of the upper state. The electric-quadrupole moment of the (2)F(7/2) state is measured as -0.041(5)ea(0)(2), where e is the elementary charge and a(0) the Bohr radius. We also obtain information on the differential scalar and tensorial components of the static polarizability and of the probe-light-induced ac Stark shift of the octupole transition. With a real-time extrapolation scheme that eliminates this shift, the unperturbed transition frequency is realized with a fractional uncertainty of 7.1×10(-17). The frequency is measured as 642 121 496 772 645.15(52) Hz.

  15. Extensive Air Showers: High Energy Phenomena and Astrophysical Aspects - A Tutorial, Reference Manual and Data Book

    Science.gov (United States)

    Grieder, P. K. F.

    Extensive air showers are a very unique phenomenon. In the more than six decades since their discovery by Auger et al. we have learned a great deal about these extremely energetic events and gained deep insights into high-energy phenomena, particle physics and astrophysics. In this Tutorial, Reference Manual and Data Book Peter K. F. Grieder provides the reader with a comprehensive view of the phenomenology and facts of the various types of interactions and cascades, theoretical background, experimental methods, data evaluation and interpretation, and air shower simulation. He discusses astrophysical aspects of the primary radiation and addresses the questions that continue to puzzle researchers.

  16. High quality reference genome of drumstick tree (Moringa oleifera Lam.), a potential perennial crop.

    Science.gov (United States)

    Tian, Yang; Zeng, Yan; Zhang, Jing; Yang, ChengGuang; Yan, Liang; Wang, XuanJun; Shi, ChongYing; Xie, Jing; Dai, TianYi; Peng, Lei; Zeng Huan, Yu; Xu, AnNi; Huang, YeWei; Zhang, JiaJin; Ma, Xiao; Dong, Yang; Hao, ShuMei; Sheng, Jun

    2015-07-01

    The drumstick tree (Moringa oleifera Lam.) is a perennial crop that has gained popularity in certain developing countries for its high-nutrition content and adaptability to arid and semi-arid environments. Here we report a high-quality draft genome sequence of M. oleifera. This assembly represents 91.78% of the estimated genome size and contains 19,465 protein-coding genes. Comparative genomic analysis between M. oleifera and related woody plant genomes helps clarify the general evolution of this species, while the identification of several species-specific gene families and positively selected genes in M. oleifera may help identify genes related to M. oleifera's high protein content, fast-growth, heat and stress tolerance. This reference genome greatly extends the basic research on M. oleifera, and may further promote applying genomics to enhanced breeding and improvement of M. oleifera.

  17. DURA-Peel, DURACON-Based Removable High Accuracy IR Thermography Coatings Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Fiber reinforced composite materials are used extensively in aerospace applications due to their high stiffness and strength to weight ratio, and superior thermal,...

  18. Performance of the High Sensitivity Open Source Multi-GNSS Assisted GNSS Reference Server.

    Science.gov (United States)

    Sarwar, Ali; Rizos, Chris; Glennon, Eamonn

    2015-06-01

    The Open Source GNSS Reference Server (OSGRS) exploits the GNSS Reference Interface Protocol (GRIP) to provide assistance data to GPS receivers. Assistance can be in terms of signal acquisition and in the processing of the measurement data. The data transfer protocol is based on Extensible Mark-up Language (XML) schema. The first version of the OSGRS required a direct hardware connection to a GPS device to acquire the data necessary to generate the appropriate assistance. Scenarios of interest for the OSGRS users are weak signal strength indoors, obstructed outdoors or heavy multipath environments. This paper describes an improved version of OSGRS that provides alternative assistance support from a number of Global Navigation Satellite Systems (GNSS). The underlying protocol to transfer GNSS assistance data from global casters is the Networked Transport of RTCM (Radio Technical Commission for Maritime Services) over Internet Protocol (NTRIP), and/or the RINEX (Receiver Independent Exchange) format. This expands the assistance and support model of the OSGRS to globally available GNSS data servers connected via internet casters. A variety of formats and versions of RINEX and RTCM streams become available, which strengthens the assistance provisioning capability of the OSGRS platform. The prime motivation for this work was to enhance the system architecture of the OSGRS to take advantage of globally available GNSS data sources. Open source software architectures and assistance models provide acquisition and data processing assistance for GNSS receivers operating in weak signal environments. This paper describes test scenarios to benchmark the OSGRSv2 performance against other Assisted-GNSS solutions. Benchmarking devices include the SPOT satellite messenger, MS-Based & MS-Assisted GNSS, HSGNSS (SiRFstar-III) and Wireless Sensor Networks Assisted-GNSS. Benchmarked parameters include the number of tracked satellites, the Time to Fix First (TTFF), navigation availability

  19. Interethnic differences in the accuracy of anthropometric indicators of obesity in screening for high risk of coronary heart disease

    Science.gov (United States)

    Herrera, VM; Casas, JP; Miranda, JJ; Perel, P; Pichardo, R; González, A; Sanchez, JR; Ferreccio, C; Aguilera, X; Silva, E; Oróstegui, M; Gómez, LF; Chirinos, JA; Medina-Lezama, J; Pérez, CM; Suárez, E; Ortiz, AP; Rosero, L; Schapochnik, N; Ortiz, Z; Ferrante, D; Diaz, M; Bautista, LE

    2009-01-01

    Background Cut points for defining obesity have been derived from mortality data among Whites from Europe and the United States and their accuracy to screen for high risk of coronary heart disease (CHD) in other ethnic groups has been questioned. Objective To compare the accuracy and to define ethnic and gender-specific optimal cut points for body mass index (BMI), waist circumference (WC) and waist-to-hip ratio (WHR) when they are used in screening for high risk of CHD in the Latin-American and the US populations. Methods We estimated the accuracy and optimal cut points for BMI, WC and WHR to screen for CHD risk in Latin Americans (n=18 976), non-Hispanic Whites (Whites; n=8956), non-Hispanic Blacks (Blacks; n=5205) and Hispanics (n=5803). High risk of CHD was defined as a 10-year risk ≥20% (Framingham equation). The area under the receiver operator characteristic curve (AUC) and the misclassification-cost term were used to assess accuracy and to identify optimal cut points. Results WHR had the highest AUC in all ethnic groups (from 0.75 to 0.82) and BMI had the lowest (from 0.50 to 0.59). Optimal cut point for BMI was similar across ethnic/gender groups (27 kg/m2). In women, cut points for WC (94 cm) and WHR (0.91) were consistent by ethnicity. In men, cut points for WC and WHR varied significantly with ethnicity: from 91 cm in Latin Americans to 102 cm in Whites, and from 0.94 in Latin Americans to 0.99 in Hispanics, respectively. Conclusion WHR is the most accurate anthropometric indicator to screen for high risk of CHD, whereas BMI is almost uninformative. The same BMI cut point should be used in all men and women. Unique cut points for WC and WHR should be used in all women, but ethnic-specific cut points seem warranted among men. PMID:19238159

  20. High Accuracy Investigation of Microwave Absorption in Polymer Electrical Components on Motherboard of Computers

    Science.gov (United States)

    Dašić, P.; Hutanu, C.; Jevremović, V.; Dobra, R.; Risteiu, M.; Ileana, I.

    2017-06-01

    Electronic operating at high frequencies can have problems with emission of high frequency noise. Once put inside an enclosure, the energy will add in phase at certain frequencies to cause resonances which will hinder the performance of the device. These absorbers are based upon open celled foam impregnated with a carbon coating. It is quite possible that in the near future, microprocessors would be to work on a frequency located in 5 to 10 GHz. In these circumstances it is useful to know how and how much of the electromagnetic field emitted by a microprocessor, it is absorbed by the circuit elements in the immediate vicinity of the microprocessor. The aim of this contribution is to demonstrate throughout high-level experimental analysis how the main electric parameters of polymer materials, which build the printed circuits and the one of electric capacitors and resistors, depend on the frequencies on which they work from the microwave range.

  1. Bayesian approach increases accuracy when selecting cowpea genotypes with high adaptability and phenotypic stability.

    Science.gov (United States)

    Barroso, L M A; Teodoro, P E; Nascimento, M; Torres, F E; Dos Santos, A; Corrêa, A M; Sagrilo, E; Corrêa, C C G; Silva, F A; Ceccon, G

    2016-03-11

    This study aimed to verify that a Bayesian approach could be used for the selection of upright cowpea genotypes with high adaptability and phenotypic stability, and the study also evaluated the efficiency of using informative and minimally informative a priori distributions. Six trials were conducted in randomized blocks, and the grain yield of 17 upright cowpea genotypes was assessed. To represent the minimally informative a priori distributions, a probability distribution with high variance was used, and a meta-analysis concept was adopted to represent the informative a priori distributions. Bayes factors were used to conduct comparisons between the a priori distributions. The Bayesian approach was effective for selection of upright cowpea genotypes with high adaptability and phenotypic stability using the Eberhart and Russell method. Bayes factors indicated that the use of informative a priori distributions provided more accurate results than minimally informative a priori distributions.

  2. Mode-resolved frequency comb interferometry for high-accuracy long distance measurement

    NARCIS (Netherlands)

    Van den Berg, S.A.; Van Eldik, S.; Bhattacharya, N.

    2015-01-01

    Optical frequency combs have developed into powerful tools for distance metrology. In this paper we demonstrate absolute long distance measurement using a single femtosecond frequency comb laser as a multi-wavelength source. By applying a high-resolution spectrometer based on a virtually imaged phas

  3. Novel method of high-accuracy wavefront-phase and amplitude correction for coronagraphy

    Science.gov (United States)

    Bowers, Charles W.; Woodgate, Bruce E.; Lyon, Richard G.

    2003-11-01

    Detection of extra-solar, and especially terrestrial-like planets, using coronagraphy requires an extremely high level of wavefront correction. For example, the study of Woodruff et al. (2002) has shown that phase uniformity of order 10-4λ(rms) must be achieved over the critical range of spatial frequencies to produce the ~1010 contrast needed for the Terrestrial Planet Finder (TPF) mission. Correction of wavefront phase errors to this level may be accomplished by using a very high precision deformable mirror (DM). However, not only phase but also amplitude uniformity of the same scale (~10-4) and over the same spatial frequency range must be simultaneously obtained to remove all residual speckle in the image plane. We present a design for producing simultaneous wavefront phase and amplitude uniformity to high levels from an input wavefront of lower quality. The design uses a dual Michelson interferometer arrangement incorporating two DM and a single, fixed mirror (all at pupils) and two beamsplitters: one with unequal (asymmetric) beam splitting and one with symmetric beam splitting. This design allows high precision correction of both phase and amplitude using DM with relatively coarse steps and permits a simple correction algorithm.

  4. High-accuracy alignment based on atmospherical dispersion - technological approaches and solutions for the dual-wavelength transmitter

    Energy Technology Data Exchange (ETDEWEB)

    Burkhard, Boeckem [Institute for Geodesy and Photogrammetry, ETH Zurich (Switzerland)

    1999-07-01

    In the course of the progressive developments of sophisticated geodetic systems utilizing electromagnetic waves in the visible or near IR-range a more detailed knowledge of the propagation medium and coevally solutions of atmospherically induced limitations will become important. An alignment system based on atmospherical dispersion, called a dispersometer, is a metrological solution to the atmospherically induced limitations, in optical alignment and direction observations of high accuracy. In the dispersometer we are using the dual-wavelength method for dispersive air to obtain refraction compensated angle measurements, the detrimental impact of atmospheric turbulence notwithstanding. The principle of the dual-wavelength method utilizes atmospherical dispersion, i.e. the wavelength dependence of the refractive index. The difference angle between two light beams of different wavelengths, which is called the dispersion angle {delta}{beta}, is to first approximation proportional to the refraction angle: {beta}{sub IR} {nu}({beta}{sub blue} - {beta}{sub IR}) = {nu} {delta}{beta}, this equation implies that the dispersion angle has to be measured at least 42 times more accurate than the desired accuracy of the refraction angle for the wavelengths used in the present dispersometer. This required accuracy constitutes one major difficulty for the instrumental performance in applying the dispersion effect. However, the dual-wavelength method can only be successfully used in an optimized transmitter-receiver combination. Beyond the above mentioned resolution requirement for the detector, major difficulties in instrumental realization arise in the availability of a suitable dual-wavelength laser light source, laser light modulation with a very high extinction ratio and coaxial emittance of mono-mode radiation at both wavelengths. Therefore, this paper focuses on the solutions of the dual-wavelength transmitter introducing a new hardware approach and a complete re-design of

  5. High-accuracy identification and bioinformatic analysis of in vivo protein phosphorylation sites in yeast

    DEFF Research Database (Denmark)

    Gnad, Florian; de Godoy, Lyris M F; Cox, Jürgen

    2009-01-01

    mapped to 1118 proteins, representatively covering the yeast kinome and a multitude of transcription factors. We show that a single false discovery rate for all peptide identifications significantly overestimates occurrence of rare modifications, such as tyrosine phosphorylation in yeast. The identified...... phosphorylation sites are predominantly located on irregularly structured and accessible protein regions. We found high evolutionary conservation of phosphorylated proteins and a large overlap of significantly over-represented motifs with the human phosphoproteome. Nevertheless, phosphorylation events at the site...... level were not highly conserved between yeast and higher eukaryotes, which points to metazoan-specific kinase and substrate families. We constructed a yeast-specific phosphorylation sites predictor on the basis of a support vector machine, which - together with the yeast phosphorylation data...

  6. Challenges in high accuracy surface replication for micro optics and micro fluidics manufacture

    DEFF Research Database (Denmark)

    Tosello, Guido; Hansen, Hans Nørgaard; Calaon, Matteo;

    2014-01-01

    by replication technologies such as nickel electroplating. All replication steps are enabled by a high precision master and high reproduction fidelity to ensure that the functionalities associated with the design are transferred to the final component. Engineered surface micro structures can be either......Patterning the surface of polymer components with microstructured geometries is employed in optical and microfluidic applications. Mass fabrication of polymer micro structured products is enabled by replication technologies such as injection moulding. Micro structured tools are also produced...... distributed, e.g., to create an optical pattern, or discretised, e.g., as micro channels for fluids manipulation. Key aspects of two process chains based on replication technologies for both types of micro structures are investigated: lateral replication fidelity, dimensional control at micro scale, edge...

  7. Modelling and Control of Stepper Motors for High Accuracy Positioning Systems Used in Radioactive Environments

    OpenAIRE

    Picatoste Ruilope, Ricardo

    2014-01-01

    Hybrid Stepper Motors are widely used in open-loop position applications. They are the choice of actuation for the collimators in the Large Hadron Collider, the largest particle accelerator at CERN. In this case the positioning requirements and the highly radioactive operating environment are unique. The latter forces both the use of long cables to connect the motors to the drives which act as transmission lines and also prevents the use of standard position sensors. However, reliable and pre...

  8. The Ultrasonic Piezo Drive an Innovative Solution for High-Accuracy Positioning

    OpenAIRE

    Seiler, René; Six, Marc; Debornot, Miguel; Le Letty, Ronan; CLAEYSSEN, Frank

    2002-01-01

    Piezo-electric motors have been successfully developed for various applications like autofocus drives in camera lenses and handling equipment for semiconductor production. Their high speed and accurate positioning capability, combined with a favourable holding torque in unpowered condition, make piezo motors also very attractive for actuation purposes in spacecraft mechanisms. However, so far only a few studies have been reported considering their suitability for actual use in space. Piezo mo...

  9. High accuracy measure of atomic polarizability in an optical lattice clock

    OpenAIRE

    Sherman, J. A.; Lemke, N. D.; Hinkley, N.; Pizzocaro, M.; Fox, R. W.; Ludlow, A. D.; Oates, C. W.

    2011-01-01

    Despite being a canonical example of quantum mechanical perturbation theory, as well as one of the earliest observed spectroscopic shifts, the Stark effect contributes the largest source of uncertainty in a modern optical atomic clock through blackbody radiation. By employing an ultracold, trapped atomic ensemble and high stability optical clock, we characterize the quadratic Stark effect with unprecedented precision. We report the ytterbium optical clock's sensitivity to electric fields (suc...

  10. Two-dimensional DOA Estimation with High Accuracy for MIMO Radar Using Cross Array

    Directory of Open Access Journals (Sweden)

    Liang Hao

    2016-06-01

    Full Text Available In this study, we investigate the estimation of the Two-Dimensional (2D Direction Of Arrival (DOA in monostatic multiple-input–multiple-output radar with cross array and propose a novel, highly accurate DOA estimation method based on unitary transformation. First, we design a new unitary matrix using the central symmetry of a cross array at transmit and receive sites. Then, the rotational invariance relationships of these arrays with long and short baselines can be transformed into a real-value field via unitary transformation. In addition, non-ambiguous and highly accurate 2D DOA estimations can be obtained using a unitary dual-resolution ESPRIT algorithm. Simulations show that the proposed method can estimate 2D highly accurate spatial angles using automatic pairing without incurring the expense of array aperture and peak searching. Compared with traditional unitary transformation, the steering vectors of transmit and receive arrays can be transformed into real-value fields via the unitary matrix and the transformation method of our scheme, respectively. This effectively overcomes the problem of shift invariance factors in real-value fields that cannot be extracted using traditional algorithms. Therefore, the proposed method can absolutely compute eigenvalue decomposition and estimate parameters in a real-value field, resulting in lower computational complexity compared with traditional methods. Simulation results verify both the correctness of our theoretical analysis and the effectiveness of the proposed algorithm.

  11. Accuracy optimization of high-speed AFM measurements using Design of Experiments

    DEFF Research Database (Denmark)

    Tosello, Guido; Marinello, F.; Hansen, Hans Nørgaard

    2010-01-01

    , the estimated dimensions of measured features. The definition of scan settings is based on a comprehensive optimization that targets maximization of information from collected data and minimization of measurement uncertainty and scan time. The Design of Experiments (DOE) technique is proposed and applied......Atomic Force Microscopy (AFM) is being increasingly employed in industrial micro/nano manufacturing applications and integrated into production lines. In order to achieve reliable process and product control at high measuring speed, instrument optimization is needed. Quantitative AFM measurement...

  12. Energy-preserving numerical schemes of high accuracy for one-dimensional Hamiltonian systems

    CERN Document Server

    Cieśliński, Jan L

    2011-01-01

    We present a class of non-standard numerical schemes which are modifications of the discrete gradient method. They preserve the energy integral exactly (up to the round-off error). The considered class contains locally exact discrete gradient schemes and integrators of arbitrary high order. In numerical experiments we compare our integrators with some other numerical schemes, including the standard discrete gradient method, the leap-frog scheme and a symplectic scheme of 4th order. We study the error accumulation for very long time and the conservation of the energy integral.

  13. Towards Understanding Spontaneous Speech Word Accuracy vs. Concept Accuracy

    CERN Document Server

    Boros, M; Gallwitz, F; Goerz, G; Hanrieder, G; Niemann, H

    1996-01-01

    In this paper we describe an approach to automatic evaluation of both the speech recognition and understanding capabilities of a spoken dialogue system for train time table information. We use word accuracy for recognition and concept accuracy for understanding performance judgement. Both measures are calculated by comparing these modules' output with a correct reference answer. We report evaluation results for a spontaneous speech corpus with about 10000 utterances. We observed a nearly linear relationship between word accuracy and concept accuracy.

  14. High accuracy indirect optical manipulation of live cells with functionalized microtools

    Science.gov (United States)

    Vizsnyiczai, Gaszton; Aekbote, Badri L.; Buzás, András.; Grexa, István.; Ormos, Pál.; Kelemen, Lóránd

    2016-09-01

    Optical micro manipulation of live cells has been extensively used to study a wide range of cellular phenomena with relevance in basic research or in diagnostics. The approaches span from manipulation of many cells for high throughput measurement or sorting, to more elaborated studies of intracellular events on trapped single cells when coupled with modern imaging techniques. In case of direct cell trapping the damaging effects of light-cell interaction must be minimized, for instance with the choice of proper laser wavelength. Microbeads have already been used for trapping cells indirectly thereby reducing the irradiation damage and increasing trapping efficiency with their high refractive index contrast. We show here that such intermediate objects can be tailor-made for indirect cell trapping to further increase cell-to-focal spot distance while maintaining their free and fast maneuverability. Carefully designed structures were produced with two-photon polymerization with shapes optimized for effective manipulation and cell attachment. Functionalization of the microstructures is also presented that enables cell attachment to them within a few seconds with strength much higher that the optical forces. Fast cell actuation in 6 degrees of freedom is demonstrated with the outlook to possible applications in cell imaging.

  15. Automated high-accuracy mutation screening with the WAVE nucleic acid fragment analysis system

    Science.gov (United States)

    Hecker, Karl H.

    2002-06-01

    The analysis of DNA fragments by ion-pair reversed-phase high-performance liquid chromatography on an alkylated, nonporous poly(styrene-divinylbenzene) matrix (DNA Cartridge) using the WAVE Nucleic Acid Fragment Analysis System is a powerful and versatile tool for DNA analysis. Resolution of DNA fragments is based on two principles, size-dependent retention of double-stranded (ds) DNA and differential retention of ds vs. single-stranded (ss) DNA. Temperature Modulated Heteroduplex Analysis utilizes both principles of separation to detect single nucleotide polymorphisms (SNP) and short insertions/deletions. At a given temperature the difference in the melting between homo- and heteroduplexes is revealed by differences in retention times. The temperature at which differential melting occurs is sequence dependent and is predicated accurately using either WAVEMAKER or WAVE Navigator software, which use a modified Fixman-Friere algorithm. Detection of known and unknown sequence variations can be performed on DNA fragments of up to 1,000 base pairs with high sensitivity and specificity. The use of fluorescent labels is compatible with the technology and increases sensitivity. Retention times are increased and resolution is not affected. Fluorescent labeling significantly increases sensitivity.

  16. High-accuracy measurement of the emission spectrum of liquid xenon in the vacuum ultraviolet region

    Energy Technology Data Exchange (ETDEWEB)

    Fujii, Keiko, E-mail: fujii-keiko-nv@ynu.jp [Faculty of Engineering, Yokohama National University, Yokohama, Kanagawa 240-8501 (Japan); Endo, Yuya; Torigoe, Yui; Nakamura, Shogo [Faculty of Engineering, Yokohama National University, Yokohama, Kanagawa 240-8501 (Japan); Haruyama, Tomiyoshi; Kasami, Katsuyu [High Energy Accelerator Research Organization (KEK), Tsukuba, Ibaraki 305-0801 (Japan); Mihara, Satoshi; Saito, Kiwamu; Sasaki, Shinichi [High Energy Accelerator Research Organization (KEK), Tsukuba, Ibaraki 305-0801 (Japan); The Graduate School of Advanced Studies, Hayama, Kanagawa 240-0193 (Japan); Tawara, Hiroko [High Energy Accelerator Research Organization (KEK), Tsukuba, Ibaraki 305-0801 (Japan)

    2015-09-21

    The emission spectrum of cryogenic liquid xenon in the vacuum ultraviolet region was measured by irradiating liquid xenon with gamma-rays from a radioactive source. To achieve a high signal-to-noise ratio, we employed coincident photon counting. Additionally, the charge of the photo-sensor signals was measured to estimate the number of detected photons accurately. In addition, proper corrections were incorporated for the wavelength; response functions of the apparatus obtained using a low-pressure mercury lamp, and photon detection efficiencies of the optical system were considered. The obtained emission spectrum is found to be in the shape of a Gaussian function, with the center at 57,199±34 (stat.)±33 (syst.) cm{sup −1} (174.8±0.1 (stat.)±0.1 (syst.) nm) and the full width at half maximum of 3328±72 (stat.)±65 (syst.) cm{sup −1} (10.2±0.2 (stat.)±0.2 (sys.) nm). These results are the most accurate values obtained in terms of the data acquisition method and the calibration for the experimental system and provide valuable information regarding the high-precision instruments that employ a liquid-xenon scintillator.

  17. Modelling and Control of Stepper Motors for High Accuracy Positioning Systems Used in Radioactive Environments

    CERN Document Server

    Picatoste Ruilope, Ricardo; Masi, Alessandro

    Hybrid Stepper Motors are widely used in open-loop position applications. They are the choice of actuation for the collimators in the Large Hadron Collider, the largest particle accelerator at CERN. In this case the positioning requirements and the highly radioactive operating environment are unique. The latter forces both the use of long cables to connect the motors to the drives which act as transmission lines and also prevents the use of standard position sensors. However, reliable and precise operation of the collimators is critical for the machine, requiring the prevention of step loss in the motors and maintenance to be foreseen in case of mechanical degradation. In order to make the above possible, an approach is proposed for the application of an Extended Kalman Filter to a sensorless stepper motor drive, when the motor is separated from its drive by long cables. When the long cables and high frequency pulse width modulated control voltage signals are used together, the electrical signals difer greatl...

  18. Determination of the QCD Λ Parameter and the Accuracy of Perturbation Theory at High Energies.

    Science.gov (United States)

    Dalla Brida, Mattia; Fritzsch, Patrick; Korzec, Tomasz; Ramos, Alberto; Sint, Stefan; Sommer, Rainer

    2016-10-28

    We discuss the determination of the strong coupling α_{MS[over ¯]}(m_{Z}) or, equivalently, the QCD Λ parameter. Its determination requires the use of perturbation theory in α_{s}(μ) in some scheme s and at some energy scale μ. The higher the scale μ, the more accurate perturbation theory becomes, owing to asymptotic freedom. As one step in our computation of the Λ parameter in three-flavor QCD, we perform lattice computations in a scheme that allows us to nonperturbatively reach very high energies, corresponding to α_{s}=0.1 and below. We find that (continuum) perturbation theory is very accurate there, yielding a 3% error in the Λ parameter, while data around α_{s}≈0.2 are clearly insufficient to quote such a precision. It is important to realize that these findings are expected to be generic, as our scheme has advantageous properties regarding the applicability of perturbation theory.

  19. A magnetic bearing momentum wheel for high pointing accuracy and vibration sensitive space applications

    Science.gov (United States)

    Bichler, U. J.

    The paper describes a magnetic bearing momentum wheel (MW-X) theoretically and experimentally with attention given to its low-noise application to spacecraft attitude-control systems. The MW-X gyroscopic actuator comprises a rotor, emergency bearings, a locking mechanisms, and a drive motor, and Vernier gimballing is employed so that the rotor and the momentum vector can be tilted actively with about one degree. The MW-X utilizes a suspension-control system for noise attenuation and active vibration suppression to reduce noise from the sensor surface. The actively controlled magnetic bearing wheels are shown to provide active damping of flexible structures by means of fully controllable translational bearing forces. The MW-X devices are of interest for applications to optical communications links, space telescopes, and earth-observation satellites with high resolutions.

  20. Combination volumetric and gravimetric sorption instrument for high accuracy measurements of methane adsorption

    Science.gov (United States)

    Burress, Jacob; Bethea, Donald; Troub, Brandon

    2017-05-01

    The accurate measurement of adsorbed gas up to high pressures (˜100 bars) is critical for the development of new materials for adsorbed gas storage. The typical Sievert-type volumetric method introduces accumulating errors that can become large at maximum pressures. Alternatively, gravimetric methods employing microbalances require careful buoyancy corrections. In this paper, we present a combination gravimetric and volumetric system for methane sorption measurements on samples between ˜0.5 and 1 g. The gravimetric method described requires no buoyancy corrections. The tandem use of the gravimetric method allows for a check on the highest uncertainty volumetric measurements. The sources and proper calculation of uncertainties are discussed. Results from methane measurements on activated carbon MSC-30 and metal-organic framework HKUST-1 are compared across methods and within the literature.

  1. Ultraviolet Raman lidar for high-accuracy profiling of aerosol extinction coefficient

    Institute of Scientific and Technical Information of China (English)

    Fei Gao; Xiaoquan Song; Yufeng Wang; Yi Zhou; Dengxin Hua

    2009-01-01

    An ultraviolet (UV) Raman lidar system at 354.7 nm has been developed for accurately measuring the aerosol extinction profiles. A spectroscopic filter combining a high-spectral-resolution grating with two narrowband mirrors is used to separate the vibrational Raman scattering signal of N2 at a central wave-length of 386.7 nm and the elastic scattering signal at 354.7 nm. The aerosol extinction is derived from the Raman scattering of N2 and the elastic scattering by the use of Raman method and Klett method, respectively. The derived results of aerosol extinction are used to compare the difference of two retrieval methods, and the preliminary experiment shows that the Raman lidar system operated in analog detection mode has the capability of measuring aerosol profiles up to a height of 3 km with a laser energy of 250 mJ and an integration time of 8 min.

  2. High Accuracy Tracking of Space-Borne Non-Cooperative Targets

    DEFF Research Database (Denmark)

    Pedersen, David Arge Klevang

    for the spacecraft to navigate safely and autonomously towards the target. These methods are applied on three distinct study cases, which are based on the platform of the microASC instrument. In relation to the Mars2020 rover, a structured light system is used to navigate the PIXL instrument towards the Martian...... the surface and to enhance the PIXL instrument's capabilities with highly accurate distance measurements. Optical observations of planetary bodies and satellites are utilized to determine the inertial position of a spacecraft. A software module is developed, tested and verified by both ground based and in......-ight observations, where the performanceover the complete operational envelope is characterized by simulations. The in-flight observations were captured onboard Juno, during the Earth flyby, by the microASC instrument, operating as an inertially controlled imager. The involvement in Juno's Earth Fly By operational...

  3. High accuracy measurements of dry mole fractions of carbon dioxide and methane in humid air

    Directory of Open Access Journals (Sweden)

    C. W. Rella

    2012-08-01

    Full Text Available Traditional techniques for measuring the mole fractions of greenhouse gas in the well-mixed atmosphere have required extremely dry sample gas streams (dew point < −25 °C to achieve the inter-laboratory compatibility goals set forth by the Global Atmospheric Watch program of the World Meteorological Organization (WMO/GAW for carbon dioxide (±0.1 ppm and methane (±2 ppb. Drying the sample gas to low levels of water vapor can be expensive, time-consuming, and/or problematic, especially at remote sites where access is difficult. Recent advances in optical measurement techniques, in particular Cavity Ring Down Spectroscopy (CRDS, have led to the development of highly stable and precise greenhouse gas analyzers capable of highly accurate measurements of carbon dioxide, methane, and water vapor. Unlike many older technologies, which can suffer from significant uncorrected interference from water vapor, these instruments permit for the first time accurate and precise greenhouse gas measurements that can meet the WMO/GAW inter-laboratory compatibility goals without drying the sample gas. In this paper, we present laboratory methodology for empirically deriving the water vapor correction factors, and we summarize a series of in-situ validation experiments comparing the measurements in humid gas streams to well-characterized dry-gas measurements. By using the manufacturer-supplied correction factors, the dry-mole fraction measurements have been demonstrated to be well within the GAW compatibility goals up to at least 1% water vapor. By determining the correction factors for individual instruments once at the start of life, this range can be extended to at least 2% over the life of the instrument, and if the correction factors are determined periodically over time, the evidence suggests that this range can be extended above 4%.

  4. Measurement of Nuclear Reaction Q-values with High Accuracy: 7Li(p, n)7Be

    Science.gov (United States)

    White, R. E.; Barker, P. H.; Lovelock, D. M. J.

    1985-01-01

    A technique is described for the measurement of nuclear reaction Q-values with an accuracy of a few parts in 105, in which the ultimate reference is a one-volt standard. As a test of the technique the accurately known threshold energy of the 7Li(p, n)7Be reaction, 1880.51 +/- 0.08 keV, has been remeasured. The value found using the present technique is 1880.443 +/- 0.020 keV, in good agreement with previous values. An attempt to see evidence for atomic excitation effects in the 27A1(p,n)27Si reaction is also discussed. This yielded a new value of 5803.73 +/- 0.12 keV for the threshold of this reaction, again in a good agreement with, but more accurate than, previous values. Further test measurements are summarized. The main application of the technique, in measurements related to the theory of weak interactions, is discussed briefly and the results obtained to date are presented.

  5. Usability Testing Analysis on The Bana Game as Education Game Design References on Junior High School

    Directory of Open Access Journals (Sweden)

    F. Adnan

    2017-04-01

    Full Text Available Learning media is one of the important elements in the learning process. Technological development support makes learning media more varied. The approach of using digital technology as a learning media has a better and more effective impact than other approaches. In order to increase the students’ learning interest, it requires the support of an interesting learning media. The use of gaming applications as learning media can improve learning outcomes. The benefits of using the maximum application cannot be separated from the determination of application design. The Bana game aims to increase the ability of critical thinking of the junior high school students. The usability-testing analysis on the Bana game application is used in order to get the design reference as an educational game development. The game is used as an object of the analysis because it has the same characteristics and goals with the game application to be developed. Usability Testing is a method used to measure the ease of use of an application by users. The Usability Testing consists of learnability, efficiency, memorability, errors, and satisfaction. The results of the analysis obtained will be used as a reference for educational game applications that will be developed.

  6. Reference-free, high-resolution measurement method of timing jitter spectra of optical frequency combs

    Science.gov (United States)

    Kwon, Dohyeon; Jeon, Chan-Gi; Shin, Junho; Heo, Myoung-Sun; Park, Sang Eon; Song, Youjian; Kim, Jungwon

    2017-01-01

    Timing jitter is one of the most important properties of femtosecond mode-locked lasers and optical frequency combs. Accurate measurement of timing jitter power spectral density (PSD) is a critical prerequisite for optimizing overall noise performance and further advancing comb applications both in the time and frequency domains. Commonly used jitter measurement methods require a reference mode-locked laser with timing jitter similar to or lower than that of the laser-under-test, which is a demanding requirement for many laser laboratories, and/or have limited measurement resolution. Here we show a high-resolution and reference-source-free measurement method of timing jitter spectra of optical frequency combs using an optical fibre delay line and optical carrier interference. The demonstrated method works well for both mode-locked oscillators and supercontinua, with 2 × 10−9 fs2/Hz (equivalent to −174 dBc/Hz at 10-GHz carrier frequency) measurement noise floor. The demonstrated method can serve as a simple and powerful characterization tool for timing jitter PSDs of various comb sources including mode-locked oscillators, supercontinua and recently emerging Kerr-frequency combs; the jitter measurement results enabled by our method will provide new insights for understanding and optimizing timing noise in such comb sources. PMID:28102352

  7. High estradiol levels are associated with increased mortality in older men referred to coronary angiography.

    Science.gov (United States)

    Lerchbaum, E; Pilz, S; Grammer, T B; Boehm, B O; März, W; Obermayer-Pietsch, B

    2011-09-01

    There is evidence showing an important role of estrogens in men's health. We aimed to evaluate whether estradiol levels are associated with overall mortality and specific fatal events.We measured estradiol levels in 2,078 men who were routinely referred for coronary angiography (1997-2000).The main outcome measures were Cox proportional hazard ratios (HRs) for mortality from all causes, from cardiovascular and non-cardiovascular causes including cancer according to estradiol levels.Multivariable HRs (with 95% confidence intervals) for all-cause, non-cardiovascular, and cancer mortality were 1.43 (1.08-1.91), 2.11 (1.34-3.34), and 2.27 (1.00-5.19), respectively, in the fourth estradiol quartile as compared to the first. There was no significant association of estradiol levels with cardiovascular mortality. In multivariate adjusted analyses, higher estradiol levels in men were significantly associated with prevalent strokes, peripheral vascular disease, and carotid artery stenosis compared to lower estradiol levels.High levels of estradiol are associated with all-cause and non-cardiovascular mortality in a large cohort of older men referred to coronary angiography. Further studies are warranted to confirm our results and to elucidate the underlying mechanisms. Georg Thieme Verlag KG Stuttgart · New York.

  8. Characterization of bandgap reference circuits designed for high energy physics applications

    Science.gov (United States)

    Traversi, G.; De Canio, F.; Gaioni, L.; Manghisoni, M.; Mattiazzo, S.; Ratti, L.; Re, V.; Riceputi, E.

    2016-07-01

    The objective of this work is to design a high performance bandgap voltage reference circuit in a standard commercial 65 nm CMOS technology capable of operating in harsh radiation environments. A prototype circuit based on three different devices (diode, bipolar transistor and MOSFET) was fabricated and tested. Measurement results show a temperature variation as low as ±3.4 mV over a temperature range of 170 ° C (-30 °C to 140 °C) and a line regulation at room temperature of 5.2%/V. Measured VREF is 690 mV±15 mV (3σ) for 26 samples on the same wafer. Circuits correctly operate with supply voltages in the range from 1.32 V down to 0.78 V. A reference voltage shift of only 7.6 mV (around 1.1%) was measured after irradiation with 10 keV X-rays up to an integrated dose of 225 Mrad (SiO2).

  9. Indexing Large Visual Vocabulary by Randomized Dimensions Hashing for High Quantization Accuracy: Improving the Object Retrieval Quality

    Science.gov (United States)

    Yang, Heng; Wang, Qing; He, Zhoucan

    The bag-of-visual-words approach, inspired by text retrieval methods, has proven successful in achieving high performance in object retrieval on large-scale databases. A key step of these methods is the quantization stage which maps the high-dimensional image feature vectors to discriminatory visual words. In this paper, we consider the quantization step as the nearest neighbor search in large visual vocabulary, and thus proposed a randomized dimensions hashing (RDH) algorithm to efficiently index and search the large visual vocabulary. The experimental results have demonstrated that the proposed algorithm can effectively increase the quantization accuracy compared to the vocabulary tree based methods which represent the state-of-the-art. Consequently, the object retrieval performance can be significantly improved by our method in the large-scale database.

  10. Social power and recognition of emotional prosody: High power is associated with lower recognition accuracy than low power.

    Science.gov (United States)

    Uskul, Ayse K; Paulmann, Silke; Weick, Mario

    2016-02-01

    Listeners have to pay close attention to a speaker's tone of voice (prosody) during daily conversations. This is particularly important when trying to infer the emotional state of the speaker. Although a growing body of research has explored how emotions are processed from speech in general, little is known about how psychosocial factors such as social power can shape the perception of vocal emotional attributes. Thus, the present studies explored how social power affects emotional prosody recognition. In a correlational study (Study 1) and an experimental study (Study 2), we show that high power is associated with lower accuracy in emotional prosody recognition than low power. These results, for the first time, suggest that individuals experiencing high or low power perceive emotional tone of voice differently.

  11. Hybrid single-packet IP traceback with low storage and high accuracy.

    Science.gov (United States)

    Yang, Ming Hour

    2014-01-01

    Traceback schemes have been proposed to trace the sources of attacks that usually hide by spoofing their IP addresses. Among these methods, schemes using packet logging can achieve single-packet traceback. But packet logging demands high storage on routers and therefore makes IP traceback impractical. For lower storage requirement, packet logging and packet marking are fused to make hybrid single-packet IP traceback. Despite such attempts, their storage still increases with packet numbers. That is why RIHT bounds its storage with path numbers to guarantee low storage. RIHT uses IP header's ID and offset fields to mark packets, so it inevitably suffers from fragment and drop issues for its packet reassembly. Although the 16-bit hybrid IP traceback schemes, for example, MORE, can mitigate the fragment problem, their storage requirement grows up with packet numbers. To solve the storage and fragment problems in one shot, we propose a single-packet IP traceback scheme that only uses packets' ID field for marking. Our major contributions are as follows: (1) our fragmented packets with tracing marks can be reassembled; (2) our storage is not affected by packet numbers; (3) it is the first hybrid single-packet IP traceback scheme to achieve zero false positive and zero false negative rates.

  12. Determination of the QCD Λ-parameter and the accuracy of perturbation theory at high energies

    Energy Technology Data Exchange (ETDEWEB)

    Dalla Brida, Mattia [Deutsches Elektronen-Synchrotron (DESY), Zeuthen (Germany). John von Neumann-Inst. fuer Computing NIC; Fritzsch, Patrick [Univ. Autonoma de Madrid (Spain). Inst. de Fisica Teorica UAM/CSIC; Korzec, Tomasz [Wuppertal Univ. (Germany). Dept. of Physics; Ramos, Alberto [CERN - European Organization for Nuclear Research, Geneva (Switzerland). Theory Div.; Sint, Stefan [Trinity College Dublin (Ireland). School of Mathematics; Sommer, Rainer [Deutsches Elektronen-Synchrotron (DESY), Zeuthen (Germany). John von Neumann-Inst. fuer Computing NIC; Humboldt-Universitaet, Berlin (Germany). Inst. fuer Physik; Collaboration: ALPHA Collaboration

    2016-04-15

    We discuss the determination of the strong coupling α{sub MS}(m{sub Z}) or equivalently the QCD Λ-parameter. Its determination requires the use of perturbation theory in α{sub s}(μ) in some scheme, s, and at some energy scale μ. The higher the scale μ the more accurate perturbation theory becomes, owing to asymptotic freedom. As one step in our computation of the Λ-parameter in three-flavor QCD, we perform lattice computations in a scheme which allows us to non-perturbatively reach very high energies, corresponding to α{sub s}=0.1 and below. We find that (continuum) perturbation theory is very accurate there, yielding a three percent error in the Λ-parameter, while data around α{sub s}∼0.2 is clearly insufficient to quote such a precision. It is important to realize that these findings are expected to be generic, as our scheme has advantageous properties regarding the applicability of perturbation theory.

  13. Temporal Stability of the Velodyne HDL-64E S2 Scanner for High Accuracy Scanning Applications

    Directory of Open Access Journals (Sweden)

    Craig Glennie

    2011-03-01

    Full Text Available The temporal stability and static calibration and analysis of the Velodyne HDL‑64E S2 scanning LiDAR system is discussed and analyzed. The mathematical model for measurements for the HDL-64E S2 scanner is updated to include misalignments between the angular encoder and scanner axis of rotation, which are found to be a marginally significant source of error. It is reported that the horizontal and vertical laser offsets cannot reliably be obtained with the current calibration model due to their high correlation with the horizontal and vertical offsets. By analyzing observations from two separate HDL-64E S2 scanners it was found that the temporal stability of the horizontal angle offset is near the quantization level of the encoder, but the vertical angular offset, distance offset and distance scale are slightly larger than expected. This is felt to be due to long term variations in the scanner range, whose root cause is as of yet unidentified. Nevertheless, a temporally averaged calibration dataset for each of the scanners resulted in a 25% improvement in the 3D planar misclosure residual RMSE over the standard factory calibration model.

  14. High-accuracy, high-precision, high-resolution, continuous monitoring of urban greenhouse gas emissions? Results to date from INFLUX

    Science.gov (United States)

    Davis, K. J.; Brewer, A.; Cambaliza, M. O. L.; Deng, A.; Hardesty, M.; Gurney, K. R.; Heimburger, A. M. F.; Karion, A.; Lauvaux, T.; Lopez-Coto, I.; McKain, K.; Miles, N. L.; Patarasuk, R.; Prasad, K.; Razlivanov, I. N.; Richardson, S.; Sarmiento, D. P.; Shepson, P. B.; Sweeney, C.; Turnbull, J. C.; Whetstone, J. R.; Wu, K.

    2015-12-01

    The Indianapolis Flux Experiment (INFLUX) is testing the boundaries of our ability to use atmospheric measurements to quantify urban greenhouse gas (GHG) emissions. The project brings together inventory assessments, tower-based and aircraft-based atmospheric measurements, and atmospheric modeling to provide high-accuracy, high-resolution, continuous monitoring of emissions of GHGs from the city. Results to date include a multi-year record of tower and aircraft based measurements of the urban CO2 and CH4 signal, long-term atmospheric modeling of GHG transport, and emission estimates for both CO2 and CH4 based on both tower and aircraft measurements. We will present these emissions estimates, the uncertainties in each, and our assessment of the primary needs for improvements in these emissions estimates. We will also present ongoing efforts to improve our understanding of atmospheric transport and background atmospheric GHG mole fractions, and to disaggregate GHG sources (e.g. biogenic vs. fossil fuel CO2 fluxes), topics that promise significant improvement in urban GHG emissions estimates.

  15. A Three-Dimensional Heads-Up Primary Navigation Reference Display for Paratroopers Performing High Altitude High Open Jumps

    Science.gov (United States)

    2007-11-02

    decisions. A primary navigation reference for paratroopers is directly equivalent to an aircraft’s primary flight reference ( PFR ) which provides...instrumented flight.” One can think of a primary navigation reference for paratroopers as the paratroopers’ equivalent of a PFR and extrapolate the...requirements of such a 34 reference from those of a PFR . Therefore, it follows that a paratrooper’s navigation reference is a display that

  16. Analysis of bromotryptophan and hydroxyproline modifications by high-resolution, high-accuracy precursor ion scanning utilizing fragment ions with mass-deficient mass tags.

    Science.gov (United States)

    Steen, Hanno; Mann, Matthias

    2002-12-15

    Protein modifications are often detected by precursor ion scanning. When quadrupole TOF mass spectrometers are used for precursor ion scanning with high-resolution, high-accuracy fragment ion selection, "reporter" ions are required to have a unique mass within +/-0.04 Da or less instead of +/-0.5 Da on triple quadrupole mass spectrometers, the traditional instrument used for precursor ion scanning. Thus, characteristic fragment ions can be utilized even if other fragment ions have the same nominal mass as long as the characteristic fragment ions are slightly mass deficient as compared to the other fragments, i.e., when they have an inherent mass-deficient mass tag. Here, the immonium ions of bromotryptophan and hydroxyproline are described as two fragment ions characteristic for tryptophan-brominated and proline-hydroxylated peptides, respectively. The "reporter" ion of trytophan-brominated peptides is highly mass deficient due to the presence of bromine, thereby allowing the selective detection of these species and the distinction from other dipeptidic a-, b-, and y-fragment ions by high-resolution, high-accuracy precursor ion scanning. This strategy also enables the differentiation between precursors giving rise to the oxygen-containing immonium ion of hydroxyproline and precursors of the immonium ions of near-ubiquitous leucine/isoleucine. Both immonium ions have the same nominal mass of 86 Da, but the exact masses differ by less than 0.04 Da. High-resolution, high-accuracy precursor ion scanning enabled the identification of proline-hydroxylated and tryptophan-brominated species and the directed analysis of species carrying these modifications in a highly complex Conus textile conotoxin mixture. This lead to the characterization of one novel C. textile conotoxin containing a bromotryptophan residue and one novel C. textile conotoxin carrying two hydroxyproline residues.

  17. Toward New High Temperature Reference Materials for Calorimetry and Thermal Analysis

    Directory of Open Access Journals (Sweden)

    Razouk R.

    2014-01-01

    Full Text Available The French National Metrology Laboratory LNE-LCM has developed a high temperature reference facility for accurate measurements of the specific heat capacity and of the enthalpy of fusion of materials over the temperature range [23 °C, 1000 °C]. The metrological approach was to modify a commercial Calvet calorimeter in order to lower the uncertainty of measurement and to insure the metrological traceability of the measurements to the SI units, in particular by designing a new calibration system. The enthalpies of fusion of pure metals (indium, tin and silver and of a binary alloy Ag-28Cu have been measured. The results obtained on the three pure metallic materials are in very good agreement with data obtained by other National Metrology Institutes (NMIs using adiabatic calorimetry.

  18. Extensive Air Showers High Energy Phenomena and Astrophysical Aspects - A Tutorial, Reference Manual and Data Book

    CERN Document Server

    Grieder, Peter K.F

    2010-01-01

    Extensive air showers are a very unique phenomenon. In the more than six decades since their discovery by Auger et al. we have learned a great deal about these extremely energetic events and gained deep insights into high-energy phenomena, particle physics and astrophysics. In this Tutorial, Reference Manual and Data Book Peter K. F. Grieder provides the reader with a comprehensive view of the phenomenology and facts of the various types of interactions and cascades, theoretical background, experimental methods, data evaluation and interpretation, and air shower simulation. He discusses astrophysical aspects of the primary radiation and addresses the questions that continue to puzzle researchers. The book is divided into two parts, each in its own separate volume: Part I in Volume I deals mainly with the basic theoretical framework of the processes that determine an air shower and ends with a summary of ways to extract information on the primary radiation from air shower observations. It also presents a compi...

  19. Reference crop evapotranspiration estimate using high-resolution meteorological network's data

    Directory of Open Access Journals (Sweden)

    C. Lussana

    2009-10-01

    Full Text Available Water management authorities need detailed information about each component of the hydrological balance. This document presents a method to estimate the evapotranspiration rate, initialized in order to obtain the reference crop evapotranspiration rate (ET0. By using an Optimal Interpolation (OI scheme, the hourly observations of several meteorological variables, measured by a high-resolution local meteorological network, are interpolated over a regular grid. The analysed meteorological fields, containing detailed meteorological information, enter a model for turbulent heat fluxes estimation based on Monin-Obukhov surface layer similarity theory. The obtained ET0 fields are then post-processed and disseminated to the users.

  20. Real-time integration of a tactical-grade IMU and GPS for high-accuracy positioning and navigation

    Science.gov (United States)

    Petovello, Mark G.

    2003-10-01

    The integration of the Global Positioning System (CPS) and Inertial Navigation Systems (INSs) is often used to provide accurate positioning and navigation information. For applications requiring the highest accuracy, the quality of the inertial sensors required is usually assumed to be very high. This dissertation investigates the integration of CPS with a tactical-grade Inertial Measurement Unit (IMU) for centimetre-level navigation in real-time. Different GPS/INS integration strategies are investigated to assess their relative performance in terms of position and velocity accuracy during partial and complete data outages, carrier phase ambiguity resolution after such data outages, and the overall statistical reliability of the system. In terms of statistical reliability, the traditional equations used in dynamic systems are redeveloped in light of some practical considerations, including centralized and decentralized filter architectures, and sequential versus simultaneous measurement updating. Results show that the integrated solution outperforms the GPS-only approach in all areas. The difference between loose and tight integration strategies was most significant for ambiguity resolution and system reliability. The integrated solution is capable of providing decimetre-level accuracy or better for durations of about five or ten seconds when a complete or partial CPS outage is simulated. This level of accuracy, extended over longer time intervals, is shown to reduce the time required to resolve the L1 ambiguities by an average of about 50% or more for data outages as long as 30 seconds when using a tight integration strategy. More importantly, the reliability of the ambiguity resolution process is improved with the integrated system. Statistical reliability parameters are also dramatically better when using the integrated system with the ability of detecting a single-cycle cycle slip being better and more consistent, relative to GPS-only. The effect of undetected

  1. A new TEC interpolation method based on the least squares collocation for high accuracy regional ionospheric maps

    Science.gov (United States)

    Krypiak-Gregorczyk, Anna; Wielgosz, Paweł; Jarmołowski, Wojciech

    2017-04-01

    The ionosphere plays a crucial role in space weather that affects satellite navigation as the ionospheric delay is one of the major errors in GNSS. On the other hand, GNSS observations are widely used to determine the amount of ionospheric total electron content (TEC). An important aspect in the electron content estimation at regional and global scale is adopting the appropriate interpolation strategy. In this paper we propose and validate a new method for regional TEC modeling based on least squares collocation (LSC) with noise variance estimation. This method allows for providing accurate TEC maps with high spatial and temporal resolution. Such maps may be used to support precise GNSS positioning and navigation, e.g. in RTK mode and also in the ionosphere studies. To test applicability of new TEC maps to positioning, double-difference ionospheric corrections were derived from the maps and their accuracy was analyzed. In addition, the corrections were applied to GNSS positioning and validated in ambiguity resolution domain. The tests were carried out during a strong ionospheric storm when the ionosphere is particularly difficult to model. The performance of the new approach was compared to IGS and UPC global, and CODE regional TEC maps. The results showed an advantage of our solution with resulting accuracy of the relative ionospheric corrections usually better than 10 cm, even during the ionospheric disturbances. This proves suitability of our regional TEC maps for, e.g. supporting fast ambiguity resolution in kinematic GNSS positioning.

  2. Density-Functional Theory with Dispersion-Correcting Potentials for Methane: Bridging the Efficiency and Accuracy Gap between High-Level Wave Function and Classical Molecular Mechanics Methods.

    Science.gov (United States)

    Torres, Edmanuel; DiLabio, Gino A

    2013-08-13

    Large clusters of noncovalently bonded molecules can only be efficiently modeled by classical mechanics simulations. One prominent challenge associated with this approach is obtaining force-field parameters that accurately describe noncovalent interactions. High-level correlated wave function methods, such as CCSD(T), are capable of correctly predicting noncovalent interactions, and are widely used to produce reference data. However, high-level correlated methods are generally too computationally costly to generate the critical reference data required for good force-field parameter development. In this work we present an approach to generate Lennard-Jones force-field parameters to accurately account for noncovalent interactions. We propose the use of a computational step that is intermediate to CCSD(T) and classical molecular mechanics, that can bridge the accuracy and computational efficiency gap between them, and demonstrate the efficacy of our approach with methane clusters. On the basis of CCSD(T)-level binding energy data for a small set of methane clusters, we develop methane-specific, atom-centered, dispersion-correcting potentials (DCPs) for use with the PBE0 density-functional and 6-31+G(d,p) basis sets. We then use the PBE0-DCP approach to compute a detailed map of the interaction forces associated with the removal of a single methane molecule from a cluster of eight methane molecules and use this map to optimize the Lennard-Jones parameters for methane. The quality of the binding energies obtained by the Lennard-Jones parameters we obtained is assessed on a set of methane clusters containing from 2 to 40 molecules. Our Lennard-Jones parameters, used in combination with the intramolecular parameters of the CHARMM force field, are found to closely reproduce the results of our dispersion-corrected density-functional calculations. The approach outlined can be used to develop Lennard-Jones parameters for any kind of molecular system.

  3. High accuracy measurement of the $^{235}$U(n,f) reaction cross-section in the 10-30 keV neutron energy range

    CERN Multimedia

    The analysis of the neutron flux of n_TOF (in EAR1) revealed an anomaly in the 10-30 keV neutron energy range. While the flux extracted on the basis of the $^{6}$Li(n,t)$^{4}$He and $^{10}$B(n,$\\alpha$)$^{7}$Li reactions mostly agreed with each other and with the results of FLUKA simulations of the neutron beam, the one based on the $^{235}$U(n,f) reaction was found to be systematically lower, independently of the detection system used. A possible explanation is that the $^{235}$U(n,f) crosssection in that energy region, where in principle should be known with an uncertainty of 1%, may be systematically overestimated. Such a finding, which has a negligible influence on thermal reactors, would be important for future fast critical or subcritical reactors. Furthermore, its interest is more general, since the $^{235}$U(n,f) reaction is often used at that energy to determine the neutron flux, or as reference in measurements of fission cross section of other actinides. We propose to perform a high-accuracy, high-r...

  4. Location accuracy evaluation of lightning location systems using natural lightning flashes recorded by a network of high-speed cameras

    Science.gov (United States)

    Alves, J.; Saraiva, A. C. V.; Campos, L. Z. D. S.; Pinto, O., Jr.; Antunes, L.

    2014-12-01

    This work presents a method for the evaluation of location accuracy of all Lightning Location System (LLS) in operation in southeastern Brazil, using natural cloud-to-ground (CG) lightning flashes. This can be done through a multiple high-speed cameras network (RAMMER network) installed in the Paraiba Valley region - SP - Brazil. The RAMMER network (Automated Multi-camera Network for Monitoring and Study of Lightning) is composed by four high-speed cameras operating at 2,500 frames per second. Three stationary black-and-white (B&W) cameras were situated in the cities of São José dos Campos and Caçapava. A fourth color camera was mobile (installed in a car), but operated in a fixed location during the observation period, within the city of São José dos Campos. The average distance among cameras was 13 kilometers. Each RAMMER sensor position was determined so that the network can observe the same lightning flash from different angles and all recorded videos were GPS (Global Position System) time stamped, allowing comparisons of events between cameras and the LLS. The RAMMER sensor is basically composed by a computer, a Phantom high-speed camera version 9.1 and a GPS unit. The lightning cases analyzed in the present work were observed by at least two cameras, their position was visually triangulated and the results compared with BrasilDAT network, during the summer seasons of 2011/2012 and 2012/2013. The visual triangulation method is presented in details. The calibration procedure showed an accuracy of 9 meters between the accurate GPS position of the object triangulated and the result from the visual triangulation method. Lightning return stroke positions, estimated with the visual triangulation method, were compared with LLS locations. Differences between solutions were not greater than 1.8 km.

  5. James Webb Space Telescope Integrated Science Instrument Module Calibration and Verification of High-Accuracy Instrumentation to Measure Heat Flow in Cryogenic Testing

    Science.gov (United States)

    Comber, Brian; Glazer, Stuart

    2012-01-01

    The James Webb Space Telescope (JWST) is an upcoming flagship observatory mission scheduled to be launched in 2018. Three of the four science instruments are passively cooled to their operational temperature range of 36K to 40K, and the fourth instrument is actively cooled to its operational temperature of approximately 6K. The requirement for multiple thermal zoned results in the instruments being thermally connected to five external radiators via individual high purity aluminum heat straps. Thermal-vacuum and thermal balance testing of the flight instruments at the Integrated Science Instrument Module (ISIM) element level will take place within a newly constructed shroud cooled by gaseous helium inside Goddard Space Flight Center's (GSFC) Space environment Simulator (SES). The flight external radiators are not available during ISIM-level thermal vacuum/thermal testing, so they will be replaced in test with stable and adjustable thermal boundaries with identical physical interfaces to the flight radiators. Those boundaries are provided by specially designed test hardware which also measures the heat flow within each of the five heat straps to an accuracy of less than 2 mW, which is less than 5% of the minimum predicted heat flow values. Measurement of the heat loads to this accuracy is essential to ISIM thermal model correlation, since thermal models are more accurately correlated when temperature data is supplemented by accurate knowledge of heat flows. It also provides direct verification by test of several high-level thermal requirements. Devices that measure heat flow in this manner have historically been referred to a "Q-meters". Perhaps the most important feature of the design of the JWST Q-meters is that it does not depend on the absolute accuracy of its temperature sensors, but rather on knowledge of precise heater power required to maintain a constant temperature difference between sensors on two stages, for which a table is empirically developed during a

  6. Probing Atlas model atmospheres at high spectral resolution. Stellar synthesis and reference template validation

    Science.gov (United States)

    Bertone, E.; Buzzoni, A.; Chávez, M.; Rodríguez-Merino, L. H.

    2008-07-01

    Aims: The fast improvement of spectroscopic observations makes mandatory a strong effort on the theoretical side to better reproduce the spectral energy distribution (SED) of stars at high spectral resolution. In this regard, relying on the Kurucz Atlas/Synthe original codes we computed the Bluered library, consisting of 832 synthetic SED of stars, that cover a large parameter space at very high spectral resolution (R = 500 000) along the 3500-7000 Å wavelength range. Methods: Bluered synthetic spectra have been used to assess in finer detail the intrinsic reliability and the performance limits of the Atlas theoretical framework. The continuum-normalized spectra of the Sun, Arcturus, and Vega, plus a selected list of 45 bright stars with high-quality SEDs from the Prugniel & Soubiran Elodie catalog, form our sample designed to probe the global properties of synthetic spectra across the entire range of H-R parameters. Results: Atlas models display a better fitting performance with increasing stellar temperature. High-resolution spectra of Vega, the Sun, and Arcturus have been reproduced at R=100 000, respectively, within a 0.7%, 4.5%, and 8.8% relative scatter in residual flux. In all the three cases, the residual flux distribution shows a significant asymmetry (skewness parameter γ = -2.21, -0.98, -0.67, respectively), which neatly confirms an overall “excess” of theoretical line blanketing. For the Sun, this apparent discrepancy is alleviated, but not recovered, by a systematic decrease (-40%) of the line oscillator strengths, log (gf), especially referring to iron transitions. Definitely, a straight “astrophysical” determination of log (gf) for each individual atomic transition has to be devised to overcome the problem. By neglecting overblanketing effects in theoretical models when fitting high-resolution continuum-normalized spectra of real stars, we lead to a systematically warmer effective temperature (between +80 and +300 K for the solar fit) and a

  7. HIGH-FIDELITY RADIO ASTRONOMICAL POLARIMETRY USING A MILLISECOND PULSAR AS A POLARIZED REFERENCE SOURCE

    Energy Technology Data Exchange (ETDEWEB)

    Van Straten, W., E-mail: vanstraten.willem@gmail.com [Centre for Astrophysics and Supercomputing, Swinburne University of Technology, Hawthorn, VIC 3122 (Australia)

    2013-01-15

    A new method of polarimetric calibration is presented in which the instrumental response is derived from regular observations of PSR J0437-4715 based on the assumption that the mean polarized emission from this millisecond pulsar remains constant over time. The technique is applicable to any experiment in which high-fidelity polarimetry is required over long timescales; it is demonstrated by calibrating 7.2 years of high-precision timing observations of PSR J1022+1001 made at the Parkes Observatory. Application of the new technique followed by arrival time estimation using matrix template matching yields post-fit residuals with an uncertainty-weighted standard deviation of 880 ns, two times smaller than that of arrival time residuals obtained via conventional methods of calibration and arrival time estimation. The precision achieved by this experiment yields the first significant measurements of the secular variation of the projected semimajor axis, the precession of periastron, and the Shapiro delay; it also places PSR J1022+1001 among the 10 best pulsars regularly observed as part of the Parkes Pulsar Timing Array (PPTA) project. It is shown that the timing accuracy of a large fraction of the pulsars in the PPTA is currently limited by the systematic timing error due to instrumental polarization artifacts. More importantly, long-term variations of systematic error are correlated between different pulsars, which adversely affects the primary objectives of any pulsar timing array experiment. These limitations may be overcome by adopting the techniques presented in this work, which relax the demand for instrumental polarization purity and thereby have the potential to reduce the development cost of next-generation telescopes such as the Square Kilometre Array.

  8. Static Calibration and Analysis of the Velodyne HDL-64E S2 for High Accuracy Mobile Scanning

    Directory of Open Access Journals (Sweden)

    Craig Glennie

    2010-06-01

    Full Text Available The static calibration and analysis of the Velodyne HDL-64E S2 scanning LiDAR system is presented and analyzed. The mathematical model for measurements for the HDL-64E S2 scanner is derived and discussed. A planar feature based least squares adjustment approach is presented and utilized in a minimally constrained network in order to derive an optimal solution for the laser’s internal calibration parameters. Finally, the results of the adjustment along with a detailed examination of the adjustment residuals are given. A three-fold improvement in the planar misclosure residual RMSE over the standard factory calibration model was achieved by the proposed calibration. Results also suggest that there may still be some unmodelled distortions in the range measurements from the scanner. However, despite this, the overall precision of the adjusted laser scanner data appears to make it a viable choice for high accuracy mobile scanning applications.

  9. High-accuracy measurements of snow Bidirectional Reflectance Distribution Function at visible and NIR wavelengths – comparison with modelling results

    Directory of Open Access Journals (Sweden)

    Y. Arnaud

    2009-09-01

    Full Text Available High-accuracy measurements of snow Bidirectional Reflectance Distribution Function (BRDF were performed for four natural snow samples with a spectrogonio-radiometer in the 500–2600 nm wavelength range. These measurements are one of the first set of direct snow BRDF values over a wide range of lighting and viewing geometry. They were compared to BRDF calculated with two optical models. Variations of the snow anisotropy factor with lighting geometry, wavelength and snow physical properties were investigated. Results show that at wavelengths with small penetration depth, scattering mainly occurs in the very top layers and the anisotropy factor is controlled by the phase function. In this condition, forward scattering peak or double scattering peak is observed. In constrast at shorter wavelengths, the penetration of the radiation is much deeper and the number of scattering events increases. The anisotropy factor is thus nearly constant and decreases at grazing observation angles.

  10. High-accuracy measurements of snow Bidirectional Reflectance Distribution Function at visible and NIR wavelengths - comparison with modelling results

    Science.gov (United States)

    Dumont, M.; Brissaud, O.; Picard, G.; Schmitt, B.; Gallet, J.-C.; Arnaud, Y.

    2010-03-01

    High-accuracy measurements of snow Bidirectional Reflectance Distribution Function (BRDF) were performed for four natural snow samples with a spectrogonio-radiometer in the 500-2600 nm wavelength range. These measurements are one of the first sets of direct snow BRDF values over a wide range of lighting and viewing geometry. They were compared to BRDF calculated with two optical models. Variations of the snow anisotropy factor with lighting geometry, wavelength and snow physical properties were investigated. Results show that at wavelengths with small penetration depth, scattering mainly occurs in the very top layers and the anisotropy factor is controlled by the phase function. In this condition, forward scattering peak or double scattering peak is observed. In contrast at shorter wavelengths, the penetration of the radiation is much deeper and the number of scattering events increases. The anisotropy factor is thus nearly constant and decreases at grazing observation angles. The whole dataset is available on demand from the corresponding author.

  11. Fundamental M-dwarf parameters from high-resolution spectra using PHOENIX ACES models: I. Parameter accuracy and benchmark stars

    CERN Document Server

    Passegger, Vera Maria; Reiners, Ansgar

    2016-01-01

    M-dwarf stars are the most numerous stars in the Universe; they span a wide range in mass and are in the focus of ongoing and planned exoplanet surveys. To investigate and understand their physical nature, detailed spectral information and accurate stellar models are needed. We use a new synthetic atmosphere model generation and compare model spectra to observations. To test the model accuracy, we compared the models to four benchmark stars with atmospheric parameters for which independent information from interferometric radius measurements is available. We used $\\chi^2$ -based methods to determine parameters from high-resolution spectroscopic observations. Our synthetic spectra are based on the new PHOENIX grid that uses the ACES description for the equation of state. This is a model generation expected to be especially suitable for the low-temperature atmospheres. We identified suitable spectral tracers of atmospheric parameters and determined the uncertainties in $T_{\\rm eff}$, $\\log{g}$, and [Fe/H] resul...

  12. Single-reference high-precision mass measurement with a multi-reflection time-of-flight mass spectrograph

    CERN Document Server

    Ito, Y; Wada, M; Naimi, S; Sonoda, T; Mita, H; Arai, F; Takamine, A; Okada, K; Ozawa, A; Wollnik, H

    2013-01-01

    A multi-reflection time-of-flight mass spectrograph, competitive with Penning trap mass spectrometers, has been built at RIKEN. We have performed a first online mass measurement, using 8Li+ (T1/2 = 838 ms). A new analysis method has been realized, with which, using only 12C+ references, the mass excess of 8Li was accurately determined to be 20947.6(15)(34) keV (dm/m = 6.6 x 10-7). The speed, precision and accuracy of this first online measurement exemplifies the potential for using this new type of mass spectrograph for precision measurements of short-lived nuclei.

  13. High precision mobile location framework and its service based on virtual reference station of GPS

    Science.gov (United States)

    Liu, Chun; Sun, Liangyu; Yao, Lianbi

    2008-10-01

    The wireless communication technology and space technology are synchronously developed in recent years, which bring up the development of location based service (LBS). At present, many location technology methods were developed. However, all these methods can only provide a relative poor location precision and depend on high cost. The technology of Virtual Reference Station (VRS) of GPS is then involved in this paper. One of the objective in this paper is aim to give the LBS position structure to improve the mobile location position when a mobile position instrument is connected with VRS network. The cheaper GPS built-in Personal Designer Aid (PDA) is then used to achieve a higher precision by using RTCM data from existing VRS network. In order to obtain a high precision position when using the low-cost GPS receiver as a rover, the infrusture of the mobile differential correction system is then put forward. According to network transportation of RTCM via internet protocol (NTRIP), the message is communicated through wireless network, such as GPRS, CDMA and so on. The rough coordinate information is sent to VRS control center continuously, and then the VRS correction information is replied to rover in the data format of RTCM3.1. So the position will be updated based on mathematic solution after the decoding of RTCM3.1 data. The thought of LBS position can improve the precision, and can speed the LBS.

  14. Geant4 simulation of the CERN-EU high-energy reference field (CERF) facility.

    Science.gov (United States)

    Prokopovich, D A; Reinhard, M I; Cornelius, I M; Rosenfeld, A B

    2010-09-01

    The CERN-EU high-energy reference field facility is used for testing and calibrating both active and passive radiation dosemeters for radiation protection applications in space and aviation. Through a combination of a primary particle beam, target and a suitable designed shielding configuration, the facility is able to reproduce the neutron component of the high altitude radiation field relevant to the jet aviation industry. Simulations of the facility using the GEANT4 (GEometry ANd Tracking) toolkit provide an improved understanding of the neutron particle fluence as well as the particle fluence of other radiation components present. The secondary particle fluence as a function of the primary particle fluence incident on the target and the associated dose equivalent rates were determined at the 20 designated irradiation positions available at the facility. Comparisons of the simulated results with previously published simulations obtained using the FLUKA Monte Carlo code, as well as with experimental results of the neutron fluence obtained with a Bonner sphere spectrometer, are made.

  15. Effect of marital status on death rates. Part 1: High accuracy exploration of the Farr-Bertillon effect

    Science.gov (United States)

    Richmond, Peter; Roehner, Bertrand M.

    2016-05-01

    The Farr-Bertillon law says that for all age-groups the death rate of married people is lower than the death rate of people who are not married (i.e. single, widowed or divorced). Although this law has been known for over 150 years, it has never been established with well-controlled accuracy (e.g. error bars). This even let some authors argue that it was a statistical artifact. It is true that the data must be selected with great care, especially for age groups of small size (e.g. widowers under 25). The observations reported in this paper were selected in the way experiments are designed in physics, that is to say with the objective of minimizing error bars. Data appropriate for mid-age groups may be unsuitable for young age groups and vice versa. The investigation led to the following results. (1) The FB effect is very similar for men and women, except that (at least in western countries) its amplitude is 20% higher for men. (2) There is a marked difference between single/divorced persons on the one hand, for whom the effect is largest around the age of 40, and widowed persons on the other hand, for whom the effect is largest around the age of 25. (3) When different causes of death are distinguished, the effect is largest for suicide and smallest for cancer. For heart disease and cerebrovascular accidents, the fact of being married divides the death rate by 2.2 compared to non-married persons. (4) For young widowers the death rates are up to 10 times higher than for married persons of same age. This extreme form of the FB effect will be referred to as the "young widower effect". Chinese data are used to explore this effect more closely. A possible connection between the FB effect and Martin Raff's "Stay alive" effect for the cells in an organism is discussed in the last section.

  16. Real-time continuous glucose monitoring shows high accuracy within 6 hours after sensor calibration: a prospective study.

    Directory of Open Access Journals (Sweden)

    Xiao-Yan Yue

    Full Text Available Accurate and timely glucose monitoring is essential in intensive care units. Real-time continuous glucose monitoring system (CGMS has been advocated for many years to improve glycemic management in critically ill patients. In order to determine the effect of calibration time on the accuracy of CGMS, real-time subcutaneous CGMS was used in 18 critically ill patients. CGMS sensor was calibrated with blood glucose measurements by blood gas/glucose analyzer every 12 hours. Venous blood was sampled every 2 to 4 hours, and glucose concentration was measured by standard central laboratory device (CLD and by blood gas/glucose analyzer. With CLD measurement as reference, relative absolute difference (mean±SD in CGMS and blood gas/glucose analyzer were 14.4%±12.2% and 6.5%±6.2%, respectively. The percentage of matched points in Clarke error grid zone A was 74.8% in CGMS, and 98.4% in blood gas/glucose analyzer. The relative absolute difference of CGMS obtained within 6 hours after sensor calibration (8.8%±7.2% was significantly less than that between 6 to 12 hours after calibration (20.1%±13.5%, p<0.0001. The percentage of matched points in Clarke error grid zone A was also significantly higher in data sets within 6 hours after calibration (92.4% versus 57.1%, p<0.0001. In conclusion, real-time subcutaneous CGMS is accurate in glucose monitoring in critically ill patients. CGMS sensor should be calibrated less than 6 hours, no matter what time interval recommended by manufacturer.

  17. Novel technique to suppress hydrocarbon contamination for high accuracy determination of carbon content in steel by FE-EPMA

    Science.gov (United States)

    Yamashita, Takako; Tanaka, Yuji; Yagoshi, Masayasu; Ishida, Kiyohito

    2016-07-01

    In multiphase steels, control of the carbon contents in the respective phases is the most important factor in alloy design for achieving high strength and high ductility. However, it is unusually difficult to determine the carbon contents in multiphase structures with high accuracy by electron probe microanalysis (EPMA) due to the unavoidable effect of hydrocarbon contamination during measurements. We have investigated new methods for suppressing hydrocarbon contamination during field emission (FE) EPMA measurements as well as a conventional liquid nitrogen trap. Plasma cleaner inside the specimen chamber results in a improvement of carbon-content determination by point analysis, increasing precision tenfold from the previous 0.1 mass%C to 0.01 mass%C. Stage heating at about 100 °C dramatically suppresses contamination growth during continuous point measurement and mapping. By the combination of above two techniques, we successfully visualized the two-dimensional carbon distribution in a dual-phase steel. It was also noted that the carbon concentrations at the ferrite/martensite interfaces were not the same across all interfaces, and local variation was observed. The developed technique is expected to be a powerful tool for understanding the mechanisms of mechanical properties and microstructural evolution, thereby contributing to the design of new steel products with superior properties.

  18. High-Accuracy Tidal Flat Digital Elevation Model Construction Using TanDEM-X Science Phase Data

    Science.gov (United States)

    Lee, Seung-Kuk; Ryu, Joo-Hyung

    2017-01-01

    This study explored the feasibility of using TanDEM-X (TDX) interferometric observations of tidal flats for digital elevation model (DEM) construction. Our goal was to generate high-precision DEMs in tidal flat areas, because accurate intertidal zone data are essential for monitoring coastal environment sand erosion processes. To monitor dynamic coastal changes caused by waves, currents, and tides, very accurate DEMs with high spatial resolution are required. The bi- and monostatic modes of the TDX interferometer employed during the TDX science phase provided a great opportunity for highly accurate intertidal DEM construction using radar interferometry with no time lag (bistatic mode) or an approximately 10-s temporal baseline (monostatic mode) between the master and slave synthetic aperture radar image acquisitions. In this study, DEM construction in tidal flat areas was first optimized based on the TDX system parameters used in various TDX modes. We successfully generated intertidal zone DEMs with 57-m spatial resolutions and interferometric height accuracies better than 0.15 m for three representative tidal flats on the west coast of the Korean Peninsula. Finally, we validated these TDX DEMs against real-time kinematic-GPS measurements acquired in two tidal flat areas; the correlation coefficient was 0.97 with a root mean square error of 0.20 m.

  19. Novel technique to suppress hydrocarbon contamination for high accuracy determination of carbon content in steel by FE-EPMA.

    Science.gov (United States)

    Yamashita, Takako; Tanaka, Yuji; Yagoshi, Masayasu; Ishida, Kiyohito

    2016-07-19

    In multiphase steels, control of the carbon contents in the respective phases is the most important factor in alloy design for achieving high strength and high ductility. However, it is unusually difficult to determine the carbon contents in multiphase structures with high accuracy by electron probe microanalysis (EPMA) due to the unavoidable effect of hydrocarbon contamination during measurements. We have investigated new methods for suppressing hydrocarbon contamination during field emission (FE) EPMA measurements as well as a conventional liquid nitrogen trap. Plasma cleaner inside the specimen chamber results in a improvement of carbon-content determination by point analysis, increasing precision tenfold from the previous 0.1 mass%C to 0.01 mass%C. Stage heating at about 100 °C dramatically suppresses contamination growth during continuous point measurement and mapping. By the combination of above two techniques, we successfully visualized the two-dimensional carbon distribution in a dual-phase steel. It was also noted that the carbon concentrations at the ferrite/martensite interfaces were not the same across all interfaces, and local variation was observed. The developed technique is expected to be a powerful tool for understanding the mechanisms of mechanical properties and microstructural evolution, thereby contributing to the design of new steel products with superior properties.

  20. Characterization of an experimental arrangement to measure position of particles in 3D with a high accuracy

    Science.gov (United States)

    Martínez González, A.; Guerrero Viramontes, J. A.; Moreno Hernández, D.

    2011-09-01

    Single particle position calculation in three dimensions (3D) with high accuracy is the very important in several branches of science. On the other hand, the use of in-line holography to study very small objects in a dynamic volume is a technique of importance for scientists and engineers across a variety of disciplines for obtaining information about size, shape, trajectory and velocity of small objects such as dust particles. However, in general for in-line holography, accurate determination of the object's position in the optical axis direction is difficult. In order to overcome this shortcoming, we proposed to use in-line holography set up to record particle images in two orthogonal forward configurations. In this study, we avoid digital holography reconstruction to calculate particle position. To determine particle position, the proposed method is based on the calculation of the size and position of the central spot size (CSS) of a particle diffraction image. The size of the CSS is calculated by using the Continuous Wavelet Transform (CWT) and Continuous Hough Transforms (CHT), an then the size of the CSS is related to a calibration curve calculated experimentally in order to determine the "z" particle position and centroid of the CSS render the "x-y" position of a particle image. The procedure proposed in this work to determine the 3D particle position is so simple since it avoids a complicated experimental set-up and several computational steps in order to obtain the 3D position of the particles. Our approach offers the following advantages: First, the mathematical accuracy, light illumination as well as particle and medium refractive indexes are used during the analysis. Second, it is not required to resolve the size of particle since we calculate only the size of CSS of a diffraction particle image pattern.

  1. Magnetohydrodynamic inertial reference system

    Science.gov (United States)

    Eckelkamp-Baker, Dan; Sebesta, Henry R.; Burkhard, Kevin

    2000-07-01

    Optical platforms increasingly require attitude knowledge and optical instrument pointing at sub-microradian accuracy. No low-cost commercial system exists to provide this level of accuracy for guidance, navigation, and control. The need for small, inexpensive inertial sensors, which may be employed in pointing control systems that are required to satisfy angular line-of-sight stabilization jitter error budgets to levels of 1-3 microradian rms and less, has existed for at least two decades. Innovations and evolutions in small, low-noise inertial angular motion sensor technology and advances in the applications of the global positioning system have converged to allow improvement in acquisition, tracking and pointing solutions for a wide variety of payloads. We are developing a small, inexpensive, and high-performance inertial attitude reference system that uses our innovative magnetohydrodynamic angular rate sensor technology.

  2. A vacuum double-crystal spectrometer for reference-free highly charged ions X-ray spectroscopy

    CERN Document Server

    Amaro, P; Schlesser, S; Gumberidze, Alexandre; Kessler, Ernest G; Henins, Albert; Bigot, E -O Le; Trassinelli, M; Isac, Jean-Michel; Travers, Pascal; Guerra, Mauro; Santos, J P; Indelicato, Paul

    2012-01-01

    We have built a vacuum double crystal spectrometer, which coupled to an electron-cyclotron resonance ion source, allows to measure low-energy x-ray transitions in highly-charged ions with accuracies of the order of a few parts per million. We describe in detail the instrument and its performances. Furthermore, we present a few spectra of transitions in Ar$^{14+}$, Ar$^{15+}$ and Ar$^{16+}$. We have developed an \\emph{ab initio} simulation code that allows us to obtain accurate line profiles. It can reproduce experimental spectra with unprecedented accuracy. The quality of the profiles allows the direct determination of line width.

  3. Optimization and design of inter-stage amplifier with wide output swing,high speed and high accuracy

    Institute of Scientific and Technical Information of China (English)

    ZHAO Yi-qiang; SUN Quan; GAO Jing

    2008-01-01

    To satisfy the design requirements of analog-to-digital converter (ADC) of high speed sampling sys-tem in an infrared focal plane array tester with 1024 × 1024 pixels, a first inter-stage amplifier of 12-bit 40-Msample/s pipelined ADC was designed with 0.35 μm CMOS technology. On the basis of traditional two-stage amplifier, the cross-coupled class AB output stage and cascode compensation were adopted to improve the out-put voltage swing and bandwidth. Power dissipation was optimized with math tools. Circuit and layout design were completed. Simulation results show that the designed amplifier has good performance of 95 dB de gain, ±2 V output voltage swing, 190 MHz bandwidth and 63° phase margin with feedback factor 1/4, 33 mW pow-er dissipation and so on, which can meet the system requirements.

  4. Diagnostic accuracy of sensitive or high-sensitive troponin on presentation for myocardial infarction: a meta-analysis and systematic review

    Directory of Open Access Journals (Sweden)

    Sethi A

    2014-07-01

    Full Text Available Ankur Sethi,1 Anurag Bajaj,2 Gurveen Malhotra,1 Rohit R Arora,1 Sandeep Khosla1 1Department of Medicine, Division of Cardiology, Rosalind Franklin University of Medicine and Science, North Chicago, IL, USA; 2Department of Medicine, Wright Center of Graduate Medical Education, Scranton, PA, USA Background: Recently, high-sensitive troponin (hsTrop assays consistent with professional societies' recommendations became available. We aimed to summarize the evidence on the diagnostic accuracy of hsTrop on presentation. Methods: We searched electronic databases for studies evaluating the diagnostic accuracy of hsTrop in suspected acute coronary syndrome (ACS patients. Random effect meta-analyses and meta-regression were performed. Primary and secondary analyses were restricted to studies using conventional Trop and hsTrop in the reference standard, respectively. Results: Fifteen studies with a total of 8,628 patients met the inclusion criteria for the primary analysis. hsTrop T (Hoffman-La Roche Ltd and hsTrop I (Siemens had sensitivities of 0.89 (95% confidence interval [CI]: 0.86–0.91 and 0.90 (95% CI: 0.87–0.92 and specificities of 0.79 (95% CI: 0.77–0.80 and 0.89 (95% CI: 0.87–0.90, respectively. There was no statistically significant difference in the area under the curve between hsTrop (95% CI: 0.920 and conventional Trop (95% CI: 0.929 at the 99th percentile (P=0.62. hsTrop at the level of detection had a sensitivity of 0.97 (95% CI: 0.96–0.98 and a specificity of 0.41 (95% CI: 0.40–0.42. The studies using a cut-off at coefficient of variance <10% as opposed to the 99th percentile for the conventional assay used for diagnosis reported higher diagnostic accuracy (relative diagnostic odds ratio =2.13, P=0.02. Five studies were included in the secondary analysis; hsTrop T (Hoffman-La Roche Ltd had a sensitivity of 0.91 (95% CI: 0.89–0.93 and a specificity of 0.67 (95% CI: 0.63–0.70. There was significant heterogeneity among the

  5. Comparison of the temperature accuracy between smart phone based and high-end thermal cameras using a temperature gradient phantom

    Science.gov (United States)

    Klaessens, John H.; van der Veen, Albert; Verdaasdonk, Rudolf M.

    2017-03-01

    Recently, low cost smart phone based thermal cameras are being considered to be used in a clinical setting for monitoring physiological temperature responses such as: body temperature change, local inflammations, perfusion changes or (burn) wound healing. These thermal cameras contain uncooled micro-bolometers with an internal calibration check and have a temperature resolution of 0.1 degree. For clinical applications a fast quality measurement before use is required (absolute temperature check) and quality control (stability, repeatability, absolute temperature, absolute temperature differences) should be performed regularly. Therefore, a calibrated temperature phantom has been developed based on thermistor heating on both ends of a black coated metal strip to create a controllable temperature gradient from room temperature 26 °C up to 100 °C. The absolute temperatures on the strip are determined with software controlled 5 PT-1000 sensors using lookup tables. In this study 3 FLIR-ONE cameras and one high end camera were checked with this temperature phantom. The results show a relative good agreement between both low-cost and high-end camera's and the phantom temperature gradient, with temperature differences of 1 degree up to 6 degrees between the camera's and the phantom. The measurements were repeated as to absolute temperature and temperature stability over the sensor area. Both low-cost and high-end thermal cameras measured relative temperature changes with high accuracy and absolute temperatures with constant deviations. Low-cost smart phone based thermal cameras can be a good alternative to high-end thermal cameras for routine clinical measurements, appropriate to the research question, providing regular calibration checks for quality control.

  6. Precision of high-resolution multibeam echo sounding coupled with high-accuracy positioning in a shallow water coastal environment

    Science.gov (United States)

    Ernstsen, Verner B.; Noormets, Riko; Hebbeln, Dierk; Bartholomä, Alex; Flemming, Burg W.

    2006-09-01

    Over 4 years, repetitive bathymetric measurements of a shipwreck in the Grådyb tidal inlet channel in the Danish Wadden Sea were carried out using a state-of-the-art high-resolution multibeam echosounder (MBES) coupled with a real-time long range kinematic (LRK™) global positioning system. Seven measurements during a single survey in 2003 ( n=7) revealed a horizontal and vertical precision of the MBES system of ±20 and ±2 cm, respectively, at a 95% confidence level. By contrast, four annual surveys from 2002 to 2005 ( n=4) yielded a horizontal and vertical precision (at 95% confidence level) of only ±30 and ±8 cm, respectively. This difference in precision can be explained by three main factors: (1) the dismounting of the system between the annual surveys, (2) rougher sea conditions during the survey in 2004 and (3) the limited number of annual surveys. In general, the precision achieved here did not correspond to the full potential of the MBES system, as this could certainly have been improved by an increase in coverage density (soundings/m2), achievable by reducing the survey speed of the vessel. Nevertheless, precision was higher than that reported to date for earlier offshore test surveys using comparable equipment.

  7. High-accuracy 233U(n, f ) cross-section measurement at the white-neutron source n TOF from near-thermal to 1 MeV neutron energy

    OpenAIRE

    Sarchiapone, L.; Savvidis, I.; Konovalov, V; Stephan, C.; Tagliente, G.; Krticka, M; Rudolf, G.; Kossionides, E.; Rullhusen, P; Leeb, H.; Salgado, J.; Capote, R.; Cano-Ott, D.; Mengoni, A.; Calviño Tavares, Francisco

    2009-01-01

    The 233U(n,f ) cross section has been measured at the white neutron source n TOF in a wide energy range with a dedicated fission ionization chamber. We report here the results from ∼30 meV to 1 MeV neutron energy. The 233U(n,f ) cross section has been determined relative to a reference sample of 235U(n,f )measured simultaneously with the same detector. The very high instantaneous neutron flux and the intrinsically low background of the n TOF installation result in an accuracy arou...

  8. Accuracy of dual-source CT coronary angiography: first experience in a high pre-test probability population without heart rate control

    Energy Technology Data Exchange (ETDEWEB)

    Scheffel, Hans; Alkadhi, Hatem; Desbiolles, Lotus; Frauenfelder, Thomas; Schertler, Thomas; Husmann, Lars; Marincek, Borut; Leschka, Sebastian [University Hospital Zurich, Institute of Diagnostic Radiology, Zurich (Switzerland); Plass, Andre; Vachenauer, Robert; Grunenfelder, Juerg; Genoni, Michele [Clinic for Cardiovascular Surgery, Zurich (Switzerland); Gaemperli, Oliver; Schepis, Tiziano [University Hospital Zurich, Cardiovascular Center, Zurich (Switzerland); Kaufmann, Philipp A. [University Hospital Zurich, Cardiovascular Center, Zurich (Switzerland); University of Zurich, Center for Integrative Human Physiology, Zurich (Switzerland)

    2006-12-15

    The aim of this study was to assess the diagnostic accuracy of dual-source computed tomography (DSCT) for evaluation of coronary artery disease (CAD) in a population with extensive coronary calcifications without heart rate control. Thirty patients (24 male, 6 female, mean age 63.1{+-}11.3 years) with a high pre-test probability of CAD underwent DSCT coronary angiography and invasive coronary angiography (ICA) within 14{+-}9 days. No beta-blockers were administered prior to the scan. Two readers independently assessed image quality of all coronary segments with a diameter {>=}1.5 mm using a four-point score (1: excellent to 4: not assessable) and qualitatively assessed significant stenoses as narrowing of the luminal diameter >50%. Causes of false-positive (FP) and false-negative (FN) ratings were assigned to calcifications or motion artifacts. ICA was considered the standard of reference. Mean body mass index was 28.3{+-}3.9 kg/m{sup 2} (range 22.4-36.3 kg/m{sup 2}), mean heart rate during CT was 70.3{+-}14.2 bpm (range 47-102 bpm), and mean Agatston score was 821{+-}904 (range 0-3,110). Image quality was diagnostic (scores 1-3) in 98.6% (414/420) of segments (mean image quality score 1.68{+-}0.75); six segments in three patients were considered not assessable (1.4%). DSCT correctly identified 54 of 56 significant coronary stenoses. Severe calcifications accounted for false ratings in nine segments (eight FP/one FN) and motion artifacts in two segments (one FP/one FN). Overall sensitivity, specificity, positive and negative predictive value for evaluating CAD were 96.4, 97.5, 85.7, and 99.4%, respectively. First experience indicates that DSCT coronary angiography provides high diagnostic accuracy for assessment of CAD in a high pre-test probability population with extensive coronary calcifications and without heart rate control. (orig.)

  9. First results using a new technology for measuring masses of very short-lived nuclides with very high accuracy the MISTRAL program at ISOLDE

    CERN Document Server

    Monsanglant, C; Audi, G; Bollen, G; Borcea, C; Conreur, G; Cousin, R; Doubre, H; Duma, M; Jacotin, M; Henry, S; Képinski, J F; Kluge, H J; Lebée, G; Le Scornet, G; Lunney, S; De Saint-Simon, M; Scheidenberger, C; Thibault, C

    1999-01-01

    MISTRAL is an experimental program to measure masses of very short- lived nuclides (T$_{1/2}$ down to a few ms), with a very high accuracy (a few 10$^{-7}$). There were three data taking periods with radioactive beams and 22 masses of isotopes of Ne, Na*, Mg, Al*, K, Ca, and Ti were measured. The systematic errors are now under control at the level of 8$\\TIMES10^{-7}$, allowing to come close to the expected accuracy. Even for the very weakly produced $^{30}$Na (1 ion at the detector per proton burst), the final accuracy is 7$\\TIMES10^{-7}$. (15 refs).

  10. Parallel High Order Accuracy Methods Applied to Non-Linear Hyperbolic Equations and to Problems in Materials Sciences

    Energy Technology Data Exchange (ETDEWEB)

    Jan Hesthaven

    2012-02-06

    Final report for DOE Contract DE-FG02-98ER25346 entitled Parallel High Order Accuracy Methods Applied to Non-Linear Hyperbolic Equations and to Problems in Materials Sciences. Principal Investigator Jan S. Hesthaven Division of Applied Mathematics Brown University, Box F Providence, RI 02912 Jan.Hesthaven@Brown.edu February 6, 2012 Note: This grant was originally awarded to Professor David Gottlieb and the majority of the work envisioned reflects his original ideas. However, when Prof Gottlieb passed away in December 2008, Professor Hesthaven took over as PI to ensure proper mentoring of students and postdoctoral researchers already involved in the project. This unusual circumstance has naturally impacted the project and its timeline. However, as the report reflects, the planned work has been accomplished and some activities beyond the original scope have been pursued with success. Project overview and main results The effort in this project focuses on the development of high order accurate computational methods for the solution of hyperbolic equations with application to problems with strong shocks. While the methods are general, emphasis is on applications to gas dynamics with strong shocks.

  11. High sensitivity and accuracy dissolved oxygen (DO) detection by using PtOEP/poly(MMA-co-TFEMA) sensing film

    Science.gov (United States)

    Zhang, Ke; Zhang, Honglin; Wang, Ying; Tian, Yanqing; Zhao, Jiupeng; Li, Yao

    2017-01-01

    Fluorinated acrylate polymer has received great interest in recent years due to its extraordinary characteristics such as high oxygen permeability, good stability, low surface energy and refractive index. In this work, platinum octaethylporphyrin/poly(methylmethacrylate-co-trifluoroethyl methacrylate) (PtOEP/poly(MMA-co-TFEMA)) oxygen sensing film was prepared by the immobilizing of PtOEP in a poly(MMA-co-TFEMA) matrix and the technological readiness of optical properties was established based on the principle of luminescence quenching. It was found that the oxygen-sensing performance could be improved by optimizing the monomer ratio (MMA/TFEMA = 1:1), tributylphosphate(TBP, 0.05 mL) and PtOEP (5 μg) content. Under this condition, the maximum quenching ratio I0/I100 of the oxygen sensing film is obtained to be about 8.16, Stern-Volmer equation is I0/I = 1.003 + 2.663[O2] (R2 = 0.999), exhibiting a linear relationship, good photo-stability, high sensitivity and accuracy. Finally, the synthesized PtOEP/poly(MMA-co-TFEMA) sensing film was used for DO detection in different water samples.

  12. On the isolation of elemental carbon for micro-molar 14C accelerator mass spectrometry; evaluation of alternative isolation procedures, and accuracy assurance using a hybrid isotopic particulate carbon reference material

    Directory of Open Access Journals (Sweden)

    L. A. Currie

    2005-05-01

    Full Text Available The primary objective of the research reported here has been the development of an hybrid reference material (RM to serve as a test of accuracy for elemental carbon (EC isotopic (14C speciation measurements. Such measurements are critically important for the quantitative apportionment of fossil and biomass sources of ''soot'' (EC, the tracer of fire that has profound effects on health, atmospheric visibility, and climate. Previous studies of 14C-EC measurement quality, carried out with NIST SRM 1649a (Urban Dust, showed a range of results, but since the ''truth'' was not known for this natural matrix RM, one had to rely on isotopic-chemical consistency evidence (14C in PAH, EC of measurement validity (Currie et al., 2002. Components of the new Hybrid RM (DiesApple, however, have known 14C and EC composition, and they are nearly orthogonal (isotopically and chemically. NIST SRM 2975 (Forklift Diesel Soot has little or no 14C, and its major compositional component is EC. SRM 1515 (Apple Leaves has the 14C content of biomass-C, and it has little or no EC. Thus, the hybrid RM can serve as an absolute isotopic test for the absence of EC-mimicking pyrolysis-C from SRM 1515 in the EC isolate of the hybrid RM, together with testing for conservation of its dominant soot fraction through the isolation procedure.

  13. Development of a dual-internal-reference technique to improve accuracy when determining bacterial 16S rRNA:16S rRNA gene ratio with application to Escherichia coli liquid and aerosol samples.

    Science.gov (United States)

    Zhen, Huajun; Krumins, Valdis; Fennell, Donna E; Mainelis, Gediminas

    2015-10-01

    Accurate enumeration of rRNA content in microbial cells, e.g. by using the 16S rRNA:16S rRNA gene ratio, is critical to properly understand its relationship to microbial activities. However, few studies have considered possible methodological artifacts that may contribute to the variability of rRNA analysis results. In this study, a technique utilizing genomic DNA and 16S rRNA from an exogenous species (Pseudomonas fluorescens) as dual internal references was developed to improve accuracy when determining the 16S rRNA:16S rRNA gene ratio of a target organism, Escherichia coli. This technique was able to adequately control the variability in sample processing and analysis procedures due to nucleic acid (DNA and RNA) losses, inefficient reverse transcription of RNA, and inefficient PCR amplification. The measured 16S rRNA:16S rRNA gene ratio of E. coli increased by 2-3 fold when E. coli 16S rRNA gene and 16S rRNA quantities were normalized to the sample-specific fractional recoveries of reference (P. fluorescens) 16S rRNA gene and 16S rRNA, respectively. In addition, the intra-sample variation of this ratio, represented by coefficients of variation from replicate samples, decreased significantly after normalization. This technique was applied to investigate the temporal variation of 16S rRNA:16S rRNA gene ratio of E. coli during its non-steady-state growth in a complex liquid medium, and to E. coli aerosols when exposed to particle-free air after their collection on a filter. The 16S rRNA:16S rRNA gene ratio of E. coli increased significantly during its early exponential phase of growth; when E. coli aerosols were exposed to extended filtration stress after sample collection, the ratio also increased. In contrast, no significant temporal trend in E. coli 16S rRNA:16S rRNA gene ratio was observed when the determined ratios were not normalized based on the recoveries of dual references. The developed technique could be widely applied in studies of relationship between

  14. Inter-comparison of two high-accuracy fast-response spectroscopic sensors of carbon dioxide: a case study

    Directory of Open Access Journals (Sweden)

    B. A. Flowers

    2012-05-01

    Full Text Available Tunable diode laser absorption (TDL and cavity ring-down spectroscopic (CRDS sensors for atmospheric carbon dioxide were co-deployed during summer and fall of 2010 in field and laboratory conditions at Los Alamos National Laboratory. Both sensors were characterized for accuracy and precision for ambient carbon dioxide measurements at ground level and compared using both laboratory and ambient field data. After post-processing that included water vapor correction and calibration to WMO reference standards, overall mean [12C16O2] = 392.05 ± 8.92 ppm and [12C16O2] = 392.22 ± 9.05 ppm were observed between 29 July and 16 August 2010. The mean difference between the CRDS and TDL data for 12CO2 was 0.04 ± 1.80 ppm (±1σ in 60 s for ambient field data, demonstrating the sensors meet the WMO/IAEA compatibility standard. The observations show over the 19-day period the [CO2]CRDS'/[CO2]TDL ratio exhibits a Gaussian distribution centered at x0 = 1.003 ± 3.38 × 10−5 (±1σ, indicating the ratio is dominated by random noise as opposed to a bias in the output of either sensor. The CRDS sensor is capable of measuring [12C16O2] to a precision of 23 ppb in 1 min and decreases to 6.5 ppb in 58 min. At one and 58-min, the TDL exhibits precisions of 29 ppb and 53 ppb. The CRDS is compact, fast, and stable; the TDL is larger and requires frequent calibrations to maintain its precision. The sensors also exhibit consistent hourly averaged diurnal values underscoring the interplay of biological, anthropogenic, and transport processes regulating CO2 at the site.

  15. The Mediterranean Plio-Pleistocene: A reference frame for astronomically paced low and high latitude climate changes (Jean Baptiste Lamarck Medal Lecture)

    Science.gov (United States)

    Lourens, Lucas

    2016-04-01

    The astronomical theory of climate has revolutionized our understanding of past climate change and the development of highly accurate geologic time scales for the entire Cenozoic. Most of this understanding has started with the construction of high-resolution stable oxygen isotope (18O) records from planktonic and benthic foraminifera of open ocean deep marine sediments explored by the international drilling operations of DSDP, ODP and IODP. These efforts culminated into global ocean isotopic stacked records, which give a clear picture of the evolution of the climate state through time. Fundamental for these reconstructions are the assumptions made between the astronomical forcing and the tuned time series and the accuracy of the astronomical solution. In the past decades, an astronomically calibrated time scale for the Pliocene and Pleistocene of the Mediterranean has been developed, which has become the reference for the standard Geologic Time Scale. Characteristic of the studied marine sediments are the cyclic lithological alternations, reflecting the interference between obliquity and precession-paced low latitude climate variability. These interference patterns allowed to evaluate the accuracy of astronomical solutions and to constrain the dynamical ellipticity of the Earth and tidal dissipation by the Sun and the Moon, which in turn provided the backbone for the widely applied LR04 open ocean benthic isotope stack of the past 5 Myr. So far, the assumed time lags between orbital forcing and the global climate response as reflected in LR04 have not been tested, while these assumptions hark back to SPECMAP, using simple ice sheet models and a limited number of radiometric dates. In addition, LR04 adopted a shorter response time for the smaller ice caps during the Pliocene. Here I present the first benthic 18O record of the Mediterranean reference scale, which strikingly mirrors the LR04. I will use this record to discuss the assumed phase relations and its

  16. Emergence of realism: Enhanced visual artistry and high accuracy of visual numerosity representation after left prefrontal damage.

    Science.gov (United States)

    Takahata, Keisuke; Saito, Fumie; Muramatsu, Taro; Yamada, Makiko; Shirahase, Joichiro; Tabuchi, Hajime; Suhara, Tetsuya; Mimura, Masaru; Kato, Motoichiro

    2014-05-01

    Over the last two decades, evidence of enhancement of drawing and painting skills due to focal prefrontal damage has accumulated. It is of special interest that most artworks created by such patients were highly realistic ones, but the mechanism underlying this phenomenon remains to be understood. Our hypothesis is that enhanced tendency of realism was associated with accuracy of visual numerosity representation, which has been shown to be mediated predominantly by right parietal functions. Here, we report a case of left prefrontal stroke, where the patient showed enhancement of artistic skills of realistic painting after the onset of brain damage. We investigated cognitive, functional and esthetic characteristics of the patient׳s visual artistry and visual numerosity representation. Neuropsychological tests revealed impaired executive function after the stroke. Despite that, the patient׳s visual artistry related to realism was rather promoted across the onset of brain damage as demonstrated by blind evaluation of the paintings by professional art reviewers. On visual numerical cognition tasks, the patient showed higher performance in comparison with age-matched healthy controls. These results paralleled increased perfusion in the right parietal cortex including the precuneus and intraparietal sulcus. Our data provide new insight into mechanisms underlying change in artistic style due to focal prefrontal lesion.

  17. High-accuracy diagnostic tool for electron cloud observation in the LHC based on synchronous phase measurements

    Science.gov (United States)

    Esteban Müller, J. F.; Baudrenghien, P.; Mastoridis, T.; Shaposhnikova, E.; Valuch, D.

    2015-11-01

    Electron cloud effects, which include heat load in the cryogenic system, pressure rise, and beam instabilities, are among the main intensity limitations for the LHC operation with 25 ns spaced bunches. A new observation tool was proposed and developed to monitor the e-cloud activity and it has already been used successfully during the LHC run 1 (2010-2012) and it is being intensively used in operation during the start of the LHC run 2 (2015-2018). It is based on the fact that the power loss of each bunch due to e-cloud can be estimated using bunch-by-bunch measurement of the synchronous phase. The measurements were done using the existing beam phase module of the low-level rf control system. In order to achieve the very high accuracy required, corrections for reflection in the cables and for systematic errors need to be applied followed by a post-processing of the measurements. Results clearly show the e-cloud buildup along the bunch trains and its time evolution during each LHC fill as well as from fill to fill. Measurements during the 2012 LHC scrubbing run reveal a progressive reduction in the e-cloud activity and therefore a decrease in the secondary electron yield. The total beam power loss can be computed as a sum of the contributions from all bunches and compared with the heat load deposited in the cryogenic system.

  18. High-accuracy measurements of snow Bidirectional Reflectance Distribution Function at visible and NIR wavelengths – comparison with modelling results

    Directory of Open Access Journals (Sweden)

    M. Dumont

    2010-03-01

    Full Text Available High-accuracy measurements of snow Bidirectional Reflectance Distribution Function (BRDF were performed for four natural snow samples with a spectrogonio-radiometer in the 500–2600 nm wavelength range. These measurements are one of the first sets of direct snow BRDF values over a wide range of lighting and viewing geometry. They were compared to BRDF calculated with two optical models. Variations of the snow anisotropy factor with lighting geometry, wavelength and snow physical properties were investigated. Results show that at wavelengths with small penetration depth, scattering mainly occurs in the very top layers and the anisotropy factor is controlled by the phase function. In this condition, forward scattering peak or double scattering peak is observed. In contrast at shorter wavelengths, the penetration of the radiation is much deeper and the number of scattering events increases. The anisotropy factor is thus nearly constant and decreases at grazing observation angles. The whole dataset is available on demand from the corresponding author.

  19. The LLNL High Accuracy Volume Renderer for Unstructured Data: Capabilities, Current Limits, and Potential for ASCI/VIEWS Deployment

    Energy Technology Data Exchange (ETDEWEB)

    Williams, P L; Max, N L

    2001-06-04

    This report describes a volume rendering system for unstructured data, especially finite element data, that creates images with very high accuracy. The system will currently handle meshes whose cells are either linear or quadratic tetrahedra, or meshes with mixed cell types: tetrahedra, bricks, prisms, and pyramids. The cells may have nonplanar facets. Whenever possible, exact mathematical solutions for the radiance integrals and for interpolation are used. Accurate semitransparent shaded isosurfaces may be embedded in the volume rendering. For very small cells, subpixel accumulation by splatting is used to avoid sampling error. A new exact and efficient visibility ordering algorithm is described. The most accurate images are generated in software, however, more efficient algorithms utilizing graphics hardware may also be selected. The report describes the parallelization of the system for a distributed-shared memory multiprocessor machine, and concludes by discussing the system's limits, desirable future work, and ways to extend the system so as to be compatible with projected ASCI/VIEWS architectures.

  20. Estimating subsurface water volumes and transit times in Hokkaido river catchments, Japan, using high-accuracy tritium analysis

    Science.gov (United States)

    Gusyev, Maksym; Yamazaki, Yusuke; Morgenstern, Uwe; Stewart, Mike; Kashiwaya, Kazuhisa; Hirai, Yasuyuki; Kuribayashi, Daisuke; Sawano, Hisaya

    2015-04-01

    The goal of this study is to estimate subsurface water transit times and volumes in headwater catchments of Hokkaido, Japan, using the New Zealand high-accuracy tritium analysis technique. Transit time provides insights into the subsurface water storage and therefore provides a robust and quick approach to quantifying the subsurface groundwater volume. Our method is based on tritium measurements in river water. Tritium is a component of meteoric water, decays with a half-life of 12.32 years, and is inert in the subsurface after the water enters the groundwater system. Therefore, tritium is ideally suited for characterization of the catchment's responses and can provide information on mean water transit times up to 200 years. Only in recent years has it become possible to use tritium for dating of stream and river water, due to the fading impact of the bomb-tritium from thermo-nuclear weapons testing, and due to improved measurement accuracy for the extremely low natural tritium concentrations. Transit time of the water discharge is one of the most crucial parameters for understanding the response of catchments and estimating subsurface water volume. While many tritium transit time studies have been conducted in New Zealand, only a limited number of tritium studies have been conducted in Japan. In addition, the meteorological, orographic and geological conditions of Hokkaido Island are similar to those in parts of New Zealand, allowing for comparison between these regions. In 2014, three field trips were conducted in Hokkaido in June, July and October to sample river water at river gauging stations operated by the Ministry of Land, Infrastructure, Transport and Tourism (MLIT). These stations have altitudes between 36 m and 860 m MSL and drainage areas between 45 and 377 km2. Each sampled point is located upstream of MLIT dams, with hourly measurements of precipitation and river water levels enabling us to distinguish between the snow melt and baseflow contributions

  1. Diagnostic accuracy of GPs when using an early-intervention decision support system: a high-fidelity simulation

    Science.gov (United States)

    Kostopoulou, Olga; Porat, Talya; Corrigan, Derek; Mahmoud, Samhar; Delaney, Brendan C

    2017-01-01

    Background Observational and experimental studies of the diagnostic task have demonstrated the importance of the first hypotheses that come to mind for accurate diagnosis. A prototype decision support system (DSS) designed to support GPs’ first impressions has been integrated with a commercial electronic health record (EHR) system. Aim To evaluate the prototype DSS in a high-fidelity simulation. Design and setting Within-participant design: 34 GPs consulted with six standardised patients (actors) using their usual EHR. On a different day, GPs used the EHR with the integrated DSS to consult with six other patients, matched for difficulty and counterbalanced. Method Entering the reason for encounter triggered the DSS, which provided a patient-specific list of potential diagnoses, and supported coding of symptoms during the consultation. At each consultation, GPs recorded their diagnosis and management. At the end, they completed a usability questionnaire. The actors completed a satisfaction questionnaire after each consultation. Results There was an 8–9% absolute improvement in diagnostic accuracy when the DSS was used. This improvement was significant (odds ratio [OR] 1.41, 95% confidence interval [CI] = 1.13 to 1.77, PGPs coded significantly more data when using the DSS (mean 12.35 with the DSS versus 1.64 without), and were generally satisfied with its usability. Patient satisfaction ratings were the same for consultations with and without the DSS. Conclusion The DSS prototype was successfully employed in simulated consultations of high fidelity, with no measurable influences on patient satisfaction. The substantially increased data coding can operate as motivation for future DSS adoption. PMID:28137782

  2. High Accuracy Microwave Frequency Measurement Based on Single-Drive Dual-Parallel Mach-Zehnder Modulator

    DEFF Research Database (Denmark)

    Zhao, Ying; Deng, Lei; Pang, Xiaodan

    2011-01-01

    A novel approach for broadband microwave frequency measurement based on bias manipulation of a dual-parallel Mach-Zehnder modulator is proposed and experimentally demonstrated. A 10-3 relative error verifies a significant accuracy improvement by this method.......A novel approach for broadband microwave frequency measurement based on bias manipulation of a dual-parallel Mach-Zehnder modulator is proposed and experimentally demonstrated. A 10-3 relative error verifies a significant accuracy improvement by this method....

  3. High incidence of secondary hypertension in patients referred for renal denervation

    DEFF Research Database (Denmark)

    Olsen, Lene Kjær; Kamper, Anne-Lise; Svendsen, Jesper Hastrup

    2014-01-01

    extracted from letters and documents from referring clinics and from our physical examination. Of the 100 patients included, 68 were men and the mean age was 60 (± 12) years. Office blood pressure was 176 (± 28)/99 (± 19) mmHg and 24-h ambulatory blood pressure 156 (± 20)/88 (± 13) mmHg. The mean number......Percutaneous renal denervation is a new treatment option for patients with resistant hypertension and little is known about the eligibility of patients referred. 100 consecutive patients were referred for renal denervation from March 2011 through September 2012. Clinical data were prospectively...... of antihypertensive agents was 4.0 (± 1.6). Nearly four-fifths (82%) of the patients were categorized as having resistant hypertension based on the criteria stated by The American Heart Association's stated criteria. Nine patients declined interest in renal denervation before completing the clinical workup program...

  4. Liquid theory with high accuracy and broad applicability: Coupling parameter series expansion and non hard sphere perturbation strategy

    Science.gov (United States)

    Zhou, Shiqi

    2011-12-01

    Thermodynamic and structural properties of liquids are of fundamental interest in physics, chemistry, and biology, and perturbation approach has been fundamental to liquid theoretical approaches since the dawn of modern statistical mechanics and remains so to this day. Although thermodynamic perturbation theory (TPT) is widely used in the chemical physics community, one of the most popular versions of the TPT, i.e. Zwanzig (Zwanzig, R. W. J. Chem. Phys. 1954, 22, 1420-1426) 1st-order high temperature series expansion (HTSE) TPT and its 2nd-order counterpart under a macroscopic compressibility approximation of Barker-Henderson (Barker, J. A.; Henderson, D. J. Chem. Phys. 1967, 47, 2856-2861), have some serious shortcomings: (i) the nth-order term of the HTSE is involved with reference fluid distribution functions of order up to 2n, and the higher-order terms hence progressively become more complicated and numerically inaccessible; (ii) the performance of the HTSE rapidly deteriorates and the calculated results become even qualitatively incorrect as the temperature of interest decreases. This account deals with the developments that we have made over the last five years or so to advance a coupling parameter series expansion (CPSE) and a non hard sphere (HS) perturbation strategy that has scored some of its greatest successes in overcoming the above-mentioned difficulties. In this account (i) we expatiate on implementation details of our schemes: how input information indispensable to high-order truncation of the CPSE in both the HS and non HS perturbation schemes is calculated by an Ornstein-Zernike integral equation theory; how high-order thermodynamic quantities, such as critical parameters and excess constant volume heat capacity, are extracted from the resulting excess Helmholtz free energy with irregular and inevitable numerical errors; how to select reference potential in the non HS perturbation scheme. (ii) We give a quantitative analysis on why convergence

  5. Liquid theory with high accuracy and broad applicability: Coupling parameter series expansion and non hard sphere perturbation strategy

    Directory of Open Access Journals (Sweden)

    Shiqi Zhou

    2011-12-01

    Full Text Available Thermodynamic and structural properties of liquids are of fundamental interest in physics, chemistry, and biology, and perturbation approach has been fundamental to liquid theoretical approaches since the dawn of modern statistical mechanics and remains so to this day. Although thermodynamic perturbation theory (TPT is widely used in the chemical physics community, one of the most popular versions of the TPT, i.e. Zwanzig (Zwanzig, R. W. J. Chem. Phys. 1954, 22, 1420-1426 1st-order high temperature series expansion (HTSE TPT and its 2nd-order counterpart under a macroscopic compressibility approximation of Barker-Henderson (Barker, J. A.; Henderson, D. J. Chem. Phys. 1967, 47, 2856-2861, have some serious shortcomings: (i the nth-order term of the HTSE is involved with reference fluid distribution functions of order up to 2n, and the higher-order terms hence progressively become more complicated and numerically inaccessible; (ii the performance of the HTSE rapidly deteriorates and the calculated results become even qualitatively incorrect as the temperature of interest decreases. This account deals with the developments that we have made over the last five years or so to advance a coupling parameter series expansion (CPSE and a non hard sphere (HS perturbation strategy that has scored some of its greatest successes in overcoming the above-mentioned difficulties. In this account (i we expatiate on implementation details of our schemes: how input information indispensable to high-order truncation of the CPSE in both the HS and non HS perturbation schemes is calculated by an Ornstein-Zernike integral equation theory; how high-order thermodynamic quantities, such as critical parameters and excess constant volume heat capacity, are extracted from the resulting excess Helmholtz free energy with irregular and inevitable numerical errors; how to select reference potential in the non HS perturbation scheme. (ii We give a quantitative analysis on why

  6. Mathematizing Process of Junior High School Students to Improve Mathematics Literacy Refers PISA on RCP Learning

    Science.gov (United States)

    Wardono; Mariani, S.; Hendikawati, P.; Ikayani

    2017-04-01

    Mathematizing process (MP) is the process of modeling a phenomenon mathematically or establish the concept of a phenomenon. There are two mathematizing that is Mathematizing Horizontal (MH) and Mathematizing Vertical (MV). MH as events changes contextual problems into mathematical problems, while MV is the process of formulation of the problem into a variety of settlement mathematics by using some appropriate rules. Mathematics Literacy (ML) is the ability to formulate, implement and interpret mathematics in various contexts, including the capacity to perform reasoning mathematically and using the concepts, procedures, and facts to describe, explain or predict phenomena incident. If junior high school students are conditioned continuously to conduct mathematizing activities on RCP (RME-Card Problem) learning, it will be able to improve ML that refers PISA. The purpose of this research is to know the capability of the MP grade VIII on ML content shape and space with the matter of the cube and beams with RCP learning better than the scientific learning, upgrade MP grade VIII in the issue of the cube and beams with RCP learning better than the scientific learning in terms of cognitive styles reflective and impulsive the MP grade VIII with the approach of the RCP learning in terms of cognitive styles reflective and impulsive This research is the mixed methods model concurrent embedded. The population in this study, i.e., class VIII SMPN 1 Batang with sample two class. Data were taken with the observation, interviews, and tests and analyzed with a different test average of one party the right qualitative and descriptive. The results of this study demonstrate the capability of the MP student with RCP learning better than the scientific learning, upgrade MP with RCP learning better compare with scientific learning in term cognitive style of reflective and impulsive. The subject of the reflective group top, middle, and bottom can meet all the process of MH indicators are

  7. An evaluation of the accuracy and precision of methane prediction equations for beef cattle fed high-forage and high-grain diets.

    Science.gov (United States)

    Escobar-Bahamondes, P; Oba, M; Beauchemin, K A

    2017-01-01

    The study determined the performance of equations to predict enteric methane (CH4) from beef cattle fed forage- and grain-based diets. Many equations are available to predict CH4 from beef cattle and the predictions vary substantially among equations. The aims were to (1) construct a database of CH4 emissions for beef cattle from published literature, and (2) identify the most precise and accurate extant CH4 prediction models for beef cattle fed diets varying in forage content. The database was comprised of treatment means of CH4 production from in vivo beef studies published from 2000 to 2015. Criteria to include data in the database were as follows: animal description, intakes, diet composition and CH4 production. In all, 54 published equations that predict CH4 production from diet composition were evaluated. Precision and accuracy of the equations were evaluated using the concordance correlation coefficient (r c ), root mean square prediction error (RMSPE), model efficiency and analysis of errors. Equations were ranked using a combined index of the various statistical assessments based on principal component analysis. The final database contained 53 studies and 207 treatment means that were divided into two data sets: diets containing ⩾400 g/kg dry matter (DM) forage (n=116) and diets containing ⩽200 g/kg DM forage (n=42). Diets containing between ⩽400 and ⩾200 g/kg DM forage were not included in the analysis because of their limited numbers (n=6). Outliers, treatment means where feed was fed restrictively and diets with CH4 mitigation additives were omitted (n=43). Using the high-forage dataset the best-fit equations were the International Panel on Climate Change Tier 2 method, 3 equations for steers that considered gross energy intake (GEI) and body weight and an equation that considered dry matter intake and starch:neutral detergent fiber with r c ranging from 0.60 to 0.73 and RMSPE from 35.6 to 45.9 g/day. For the high-grain diets, the 5 best

  8. An extremely low power voltage reference with high PSRR for power-aware ASICs

    Science.gov (United States)

    Jihai, Duan; Dongyu, Deng; Weilin, Xu; Baolin, Wei

    2015-09-01

    An extremely low power voltage reference without resistors is presented for power-aware ASICs. In order to reduce the power dissipation, an Oguey current reference source is used to reduce the static current; a cascode current mirror is used to increase the power supply rejection ratio (PSRR) and reduce the line sensitivity of the circuit. The voltage reference is fabricated in SMIC 0.18-μm CMOS process. The measured results for the voltage reference demonstrate that the temperature coefficient of the voltage is 66 ppm/°C in a range from 25 to 100 °C. The line sensitivity is 0.9% in a supply voltage range of 1.8 to 3.3 V, and PSRR is -49 dB at 100 Hz. The power dissipation is 200 nW. The chip area is 0.01 mm2. The circuit can be used as an elementary circuit block for power-aware ASICs. Project supported by the National Natural Science Foundation of China (Nos. 61161003, 61264001, 61166004) and the Guangxi Natural Science Foundation (No. 2013GXNSFAA019333).

  9. Reference Management Practices of Postgraduate Students and Academic Researchers are Highly Individualized

    Directory of Open Access Journals (Sweden)

    Kimberly Miller

    2016-09-01

    Full Text Available A Review of: Melles, A., & Unsworth, K. (2015. Examining the reference management practices of humanities and social science postgraduate students and academics. Australian Academic & Research Libraries, 46(4, 250-276. http://dx.doi.org/10.1080/00048623.2015.1104790 Objective – To understand patterns in reference management practices of postgraduate students and faculty members at one institution. Design – Mixed methods online survey and semi-structured interviews. Setting – Public research university in Australia. Subjects – The survey included responses from 81 postgraduate students. Semi-structured interviews were conducted with 8 postgraduate students and 13 faculty members. Methods – The researchers distributed an 18-item survey via email to approximately 800 people who previously registered for EndNote training sessions. Survey participants were also recruited via a website advertisement. The researchers recruited postgraduate student interview participants from the list of survey respondents. Librarians invited faculty members to participate in the semi-structured interviews. Interview audio recordings were transcribed and coded for data analysis. Main Results – The survey found that 71.4% (n=55 of respondents used reference management software (RMS and 29% (n=22 did not. Over half of the students who did not use an RMS described other ad hoc or “manual” (p. 255 methods for organizing and tracking references. The majority of participants reported using EndNote (67.53%, n=52, while few respondents reported using other RMS tools like Zotero (1.3%, n=1 or Mendeley (1.3%, n = 1. Software awareness (49.32%, n=36, recommendations from faculty members (30.14%, n=22, and University support (47.95%, n=35 were the primary motivations for choosing a specific RMS. Other important factors included ease of use (32.88%, n=24 and integration with Microsoft Word (46.58%, n=34. Students preferred RMS features that support the process of

  10. Anti-aliasing filters for deriving high-accuracy DEMs from TLS data: A case study from Freeport, Texas

    Science.gov (United States)

    Xiong, Lin.; Wang, Guoquan; Wessel, Paul

    2017-03-01

    Terrestrial laser scanning (TLS), also known as ground-based Light Detection and Ranging (LiDAR), has been frequently applied to build bare-earth digital elevation models (DEMs) for high-accuracy geomorphology studies. The point clouds acquired from TLS often achieve a spatial resolution at fingerprint (e.g., 3 cm×3 cm) to handprint (e.g., 10 cm×10 cm) level. A downsampling process has to be applied to decimate the massive point clouds and obtain manageable DEMs. It is well known that downsampling can result in aliasing that causes different signal components to become indistinguishable when the signal is reconstructed from the datasets with a lower sampling rate. Conventional DEMs are mainly the results of upsampling of sparse elevation measurements from land surveying, satellite remote sensing, and aerial photography. As a consequence, the effects of aliasing caused by downsampling have not been fully investigated in the open literature of DEMs. This study aims to investigate the spatial aliasing problem of regridding dense TLS data. The TLS data collected from the beach and dune area near Freeport, Texas in the summer of 2015 are used for this study. The core idea of the anti-aliasing procedure is to apply a low-pass spatial filter prior to conducting downsampling. This article describes the successful use of a fourth-order Butterworth low-pass spatial filter employed in the Generic Mapping Tools (GMT) software package as an anti-aliasing filter. The filter can be applied as an isotropic filter with a single cutoff wavelength or as an anisotropic filter with two different cutoff wavelengths in the X and Y directions. The cutoff wavelength for the isotropic filter is recommended to be three times the grid size of the target DEM.

  11. Strategies for achieving high sequencing accuracy for low diversity samples and avoiding sample bleeding using illumina platform.

    Directory of Open Access Journals (Sweden)

    Abhishek Mitra

    Full Text Available Sequencing microRNA, reduced representation sequencing, Hi-C technology and any method requiring the use of in-house barcodes result in sequencing libraries with low initial sequence diversity. Sequencing such data on the Illumina platform typically produces low quality data due to the limitations of the Illumina cluster calling algorithm. Moreover, even in the case of diverse samples, these limitations are causing substantial inaccuracies in multiplexed sample assignment (sample bleeding. Such inaccuracies are unacceptable in clinical applications, and in some other fields (e.g. detection of rare variants. Here, we discuss how both problems with quality of low-diversity samples and sample bleeding are caused by incorrect detection of clusters on the flowcell during initial sequencing cycles. We propose simple software modifications (Long Template Protocol that overcome this problem. We present experimental results showing that our Long Template Protocol remarkably increases data quality for low diversity samples, as compared with the standard analysis protocol; it also substantially reduces sample bleeding for all samples. For comprehensiveness, we also discuss and compare experimental results from alternative approaches to sequencing low diversity samples. First, we discuss how the low diversity problem, if caused by barcodes, can be avoided altogether at the barcode design stage. Second and third, we present modified guidelines, which are more stringent than the manufacturer's, for mixing low diversity samples with diverse samples and lowering cluster density, which in our experience consistently produces high quality data from low diversity samples. Fourth and fifth, we present rescue strategies that can be applied when sequencing results in low quality data and when there is no more biological material available. In such cases, we propose that the flowcell be re-hybridized and sequenced again using our Long Template Protocol. Alternatively

  12. Eruptions of the last 2200 years at Vulcano and Vulcanello (Aeolian Islands, Italy) dated by high-accuracy archeomagnetism

    Science.gov (United States)

    Arrighi, Simone; Tanguy, Jean-Claude; Rosi, Mauro

    2006-12-01

    The recent eruptive history of the Vulcano island (Southern Italy) was investigated through the high-accuracy "large sample" archeomagnetic method (Tanguy, J.C., Le Goff, M., Principe, C., Arrighi, S., Chillemi, V., Paiotti, A., La Delfa, S., Patanè, G., 2003. Archeomagnetic dating of Mediterranean volcanics of the last 2100 years: validity and limits. Earth Planet. Sci. Lett. 211, 111-124; Tanguy, J.C., Principe, C., Arrighi, S., 2005. Comment on "Historical measurements of the Earth's magnetic field compared with remanence directions from lava flows in Italy over the last four centuries" by R. Lanza, A. Meloni, and E. Tema. Phys. Earth Planet. Interiors 152, 116-120; Arrighi, S., 2004. The large sample archeomagnetic method applied to Neapolitan volcanoes and Aeolian Islands. PhD Thesis. University of Pisa, Italy, pp. 1-186). Age determination is based upon directional geomagnetic variation reconstructed from historically dated lavas in Southern Italy, and from archeological sites in Western Europe (Gallet, Y., Genevey, A., Le Goff, M., 2002. Three millennia of directional variation of the Earth's magnetic field in Western Europe as revealed by archeological artefacts. Phys. Earth Planet. Interiors 131, 81-89) relocated to Sicily. Results in the present paper were obtained on 12 sites including 185 samples weighing 0.5-1 kg, distributed over the Vulcanello platform lavas and pyroclastic cones, and on the lava flows from the Fossa cone. It is shown that the Vulcanello platform was built by nearly continuous activity between AD 1000 and 1250, which is more than a millennium younger than believed until now from questionable interpretation of imprecise historical accounts. Most of the lavas from the Fossa cone, whose ages were rather hypothetical or known with a large uncertainty, have erupted within the same period. However, the last "Pietre Cotte" obsidian flow is confirmed to date from 1720 ± 30, in agreement with historical data (1739).

  13. High-accuracy absolute distance measurement by two-wavelength double heterodyne interferometry with variable synthetic wavelengths

    CERN Document Server

    Kuramoto, Yoshiyuki

    2014-01-01

    We present an absolute distance measurement interferometer based on a two wavelength interferometer and a variable synthetic wavelength technique. The wavelength scanning range was 12 GHz, realized with a phase accuracy of 1.0 m{\\lambda} by heterodyne detection at each measurement wavelength. This small wavelength scanning range enabled the use of distributed feedback laser diodes as an interferometer light source and a fast 20 ms wavelength scanning time by injection current control. We demonstrated a measurement range of up to 1.5 m and an accuracy better than 1.2 nm in comparison with a displacement measurement interferometer, corresponding to a relative accuracy of 10-9. In addition, we also proposed expanding the range of maximum measurement and compensation of refractive index of air for linear colliders.

  14. Patient and healthcare professional satisfaction with a new, high accuracy blood glucose meter with color range indicator and wireless connectivity.

    Science.gov (United States)

    Katz, Laurence B; Grady, Mike; Stewart, Lorna; Cameron, Hilary

    2016-07-01

    Accurate self-monitoring of blood glucose is a key component of effective self-management of glycemic control. The OneTouch VerioFlex(™) (OTVF) blood glucose monitoring system (BGMS) was evaluated for accuracy in a clinical setting. Patients also used OTVF for a 1-wk trial period and reported their level of satisfaction with meter features. In a separate study, healthcare professionals used an on-line simulator of the BGMS and answered questions about its potential utility to their patients. OTVF was accurate over a wide glucose range and met lay user and system accuracy blood glucose standards described in ISO15197:2013 as well as the accuracy requirements to fulfill US FDA expectations for 510(k) clearance of BGMS. Patients and healthcare professionals felt the features of OTVF, which has the capability to connect wirelessly to mobile devices and interact wirelessly with diabetes management software, could provide significant benefits to them or their patients.

  15. Context, accuracy, and level of inclusion of nature of science concepts in current high school physics textbooks

    Science.gov (United States)

    Alshamrani, Saeed Mohammed

    To improve K-12 students' images of the nature of science (NOS) through science textbooks, two issues must be addressed: (a) the level of NOS that ought to be included in science textbooks and (b) the treatment of this level in those textbooks. Science educators achieved a consensus level of agreement regarding what NOS aspects should be taught for K-12 science learners; however, there is a need for more clarification regarding the actual treatment of NOS in science textbooks. The purpose of this study is to investigate the NOS inclusion in high school physics textbooks. To be specific, this study examines the included NOS aspects, the frequency of NOS inclusion, the contexts exist for NOS inclusion, and the accuracy of NOS inclusion. This study utilized 12 science education studies to develop the Master Aspects of Nature of Science [MA-NOS] which includes 12 NOS aspects that ought to be included in K-12 science curriculum. The analyzed textbooks in this study are seven textbooks identified by The American Institute of Physics as the most widely used high school physics textbooks in the United States in 2005. These textbooks were used in teaching five academic levels: (a) Regular First-Year Physics, (b) Physics for Non-Science Students, (c) Honors Physics, (d) AP-B Physics, and (e) AP-C Physics. The researcher selected exclusively physics textbooks because physics is his main interest. To facilitate the content analysis of the selected textbooks, the study developed The Collection Data Coding Guide which includes six parts describing the MA-NOS aspects and the process of identifying and collecting data. For each NOS aspect, a description and one or more selected ideal indicators were provided to facilitate data collecting and judging the accuracy of NOS inclusion. This coding guide was reviewed for its content validity by two science educators who specialize in NOS. However, two types of reliability were conducted to identify the consistency of selecting NOS units

  16. Strategy for high-accuracy-and-precision retrieval of atmospheric methane from the mid-infrared FTIR network

    Directory of Open Access Journals (Sweden)

    R. Sussmann

    2011-09-01

    Full Text Available We present a strategy (MIR-GBM v1.0 for the retrieval of column-averaged dry-air mole fractions of methane (XCH4 with a precision <0.3% (1-σ diurnal variation, 7-min integration and a seasonal bias <0.14% from mid-infrared ground-based solar FTIR measurements of the Network for the Detection of Atmospheric Composition Change (NDACC, comprising 22 FTIR stations. This makes NDACC methane data useful for satellite validation and for the inversion of regional-scale sources and sinks in addition to long-term trend analysis. Such retrievals complement the high accuracy and precision near-infrared observations of the younger Total Carbon Column Observing Network (TCCON with time series dating back 15 years or so before TCCON operations began.

    MIR-GBM v1.0 is using HITRAN 2000 (including the 2001 update release and 3 spectral micro windows (2613.70–2615.40 cm−1, 2835.50–2835.80 cm−1, 2921.00–2921.60 cm−1. A first-order Tikhonov constraint is applied to the state vector given in units of per cent of volume mixing ratio. It is tuned to achieve minimum diurnal variation without damping seasonality. Final quality selection of the retrievals uses a threshold for the goodness of fit (χ2 < 1 as well as for the ratio of root-mean-square spectral noise and information content (<0.15%. Column-averaged dry-air mole fractions are calculated using the retrieved methane profiles and four-times-daily pressure-temperature-humidity profiles from National Center for Environmental Prediction (NCEP interpolated to the time of measurement.

    MIR-GBM v1.0 is the optimum of 24 tested retrieval strategies (8 different spectral micro-window selections, 3 spectroscopic line lists: HITRAN 2000, 2004, 2008. Dominant errors of the non-optimum retrieval strategies are systematic HDO/H2O-CH4 interference errors leading to a seasonal bias up to ≈5%. Therefore interference

  17. Assessment of the accuracy of PPP for very-high-frequency dynamic, satellite positioning and earthquake modeling

    Science.gov (United States)

    Moschas, F.; Avallone, A.; Moschonas, N.; Saltogianni, V.; Stiros, S.

    2012-04-01

    With the advent of various GPS/GNSS Point Positioning techniques, it became possible to model the dynamic displacement history of specific points during large and rather moderate earthquakes using satellite positioning, 1Hz and occasionally 10Hz sampling data. While there is evidence that the obtained data are precise, experience from monitoring of engineering structures like bridges, indicates that GPS/GNSS records are contaminated by coloured (mostly background noise) noise even in the cases of differential-type analysis of the satellite signals. This made the necessary the assessment of the results of different PPP processing using supervised learning techniques. Our work was based on a modification of an experiment first made to assess the potential of GPS to measure oscillations of civil engineering structures. A 10Hz GNSS antenna-receiver unit was mounted on the top of a vertical rod, fixed on the ground and forced to controlled oscillations. Oscillations were also recorded by a robotic theodolite and an accelerometer, and the whole experiment was video-recorded. A second 10Hz GNSS antenna-receiver unit was left on stable ground, in a nearby position. The rod was forced to semi-static motion (bending) and then was left to oscillate freely until still, and the whole movement was recorded by all sensors. GNSS data were analyzed both in kinematic mode and in PPP mode, using the GIPSY-OASIS II (http://gipsy-oasis.jpl.nasa.gov) (only GPS) and the PPP CRCS facility (GPS + GLONAS). Recorded PPP and differential kinematic processing coordinates (apparent displacements) were found to follow the real motion, but to be contaminated by a long-period noise. On the contrary, the short-period component of the apparent PPP displacements, obtained using high-pass filtering, were very much consistent with the real motion, with sub-mm mean deviation, though occasionally contaminated by clipping. The assessment of the very-high frequency GPS noise will provide useful information

  18. High-accuracy and robust face recognition system based on optical parallel correlator using a temporal image sequence

    Science.gov (United States)

    Watanabe, Eriko; Ishikawa, Mami; Ohta, Maiko; Kodate, Kashiko

    2005-09-01

    Face recognition is used in a wide range of security systems, such as monitoring credit card use, searching for individuals with street cameras via Internet and maintaining immigration control. There are still many technical subjects under study. For instance, the number of images that can be stored is limited under the current system, and the rate of recognition must be improved to account for photo shots taken at different angles under various conditions. We implemented a fully automatic Fast Face Recognition Optical Correlator (FARCO) system by using a 1000 frame/s optical parallel correlator designed and assembled by us. Operational speed for the 1: N (i.e. matching a pair of images among N, where N refers to the number of images in the database) identification experiment (4000 face images) amounts to less than 1.5 seconds, including the pre/post processing. From trial 1: N identification experiments using FARCO, we acquired low error rates of 2.6% False Reject Rate and 1.3% False Accept Rate. By making the most of the high-speed data-processing capability of this system, much more robustness can be achieved for various recognition conditions when large-category data are registered for a single person. We propose a face recognition algorithm for the FARCO while employing a temporal image sequence of moving images. Applying this algorithm to a natural posture, a two times higher recognition rate scored compared with our conventional system. The system has high potential for future use in a variety of purposes such as search for criminal suspects by use of street and airport video cameras, registration of babies at hospitals or handling of an immeasurable number of images in a database.

  19. Simultaneous Determination of Four Anthraquinones in Polygoni Multiflori Radix with Single Reference Standard by High Performance Liquid Chromatography

    Institute of Scientific and Technical Information of China (English)

    Hua Yang; Jun-Fang Jia; Rui Wang; Fang Long; Ping Li; Hui-Jun Li

    2015-01-01

    Objective:To establish a rapid, accurate and reliable analytical method for the simultaneous determination of four major anthraquinones in Polygoni Multiflori Radix (PMR) using single reference standard. Methods:The four components including emodin-8-O-β-D-(EMG), physcion-8-O-β-D-glucoside, emodin and physcion were separated on an ODS C18 column within 13 min and detected at 280 nm. Emodin was selected as the reference standard, and the response factor for each analyte with respect to emodin were calculated. Robustness were also tested including different columns, equipments, temperatures, detection wavelengths, and other chromatographic conditions which might influence stability of response factors. Results: The method was validated in terms of linearity (r2 > 0.9995), LOQs (0.820–3.05 ng/mL), LODs (0.180–0.920 ng/mL), precision, accuracy (95.8–103.6%, RSD Conclusion:This work provided a single standard to determine multi-components method for quantitation of four anthraquinones in PMR, which could be applied in the quality control of this herbal drug.

  20. Transformation Model with Constraints for High-Accuracy of 2D-3D Building Registration in Aerial Imagery

    Directory of Open Access Journals (Sweden)

    Guoqing Zhou

    2016-06-01

    Full Text Available This paper proposes a novel rigorous transformation model for 2D-3D registration to address the difficult problem of obtaining a sufficient number of well-distributed ground control points (GCPs in urban areas with tall buildings. The proposed model applies two types of geometric constraints, co-planarity and perpendicularity, to the conventional photogrammetric collinearity model. Both types of geometric information are directly obtained from geometric building structures, with which the geometric constraints are automatically created and combined into the conventional transformation model. A test field located in downtown Denver, Colorado, is used to evaluate the accuracy and reliability of the proposed method. The comparison analysis of the accuracy achieved by the proposed method and the conventional method is conducted. Experimental results demonstrated that: (1 the theoretical accuracy of the solved registration parameters can reach 0.47 pixels, whereas the other methods reach only 1.23 and 1.09 pixels; (2 the RMS values of 2D-3D registration achieved by the proposed model are only two pixels along the x and y directions, much smaller than the RMS values of the conventional model, which are approximately 10 pixels along the x and y directions. These results demonstrate that the proposed method is able to significantly improve the accuracy of 2D-3D registration with much fewer GCPs in urban areas with tall buildings.