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Sample records for 10-16 level accuracy

  1. Dual cesium and rubidium atomic fountain with a 10-16 level accuracy and applications

    Atomic fountains are the most accomplished development of the atomic clocks based on the cesium atom whose hyperfine resonance defines the SI second since 1967. Today these systems are among those which realize the second with the best accuracy. We present the last developments of the cold cesium and rubidium atom dual fountain experiment at LNE-SYRTE. This unique dual setup would allow to obtain an outstanding resolution in fundamental physics tests based on atomic transition frequency comparisons. In order to enable operation with both atomic species simultaneously, we designed, tested and implemented on the fountain new collimators which combine the laser lights corresponding to each atom. By comparing our rubidium fountain to another cesium fountain over a decade, we performed a test of the stability of the fine structure constant at the level of 5 * 10-16 per year. We carried on the work on the clock accuracy and we focused on the phase gradients effects in the interrogation cavity and on the microwave leakage. The fountain accuracy has been evaluated to 4 * 10-16 for the cesium clock and to 5 * 10-16 for the refurbished rubidium clock. As a powerful instrument of metrology, our fountain was implicated in many clock comparisons and contributed many times to calibrate the International Atomic Time. Furthermore, we used the fountain to perform a new test of Lorentz local invariance. (author)

  2. Multi-Accuracy-Level Burning Plasma Simulations

    The design of a reactor grade tokamak is based on a hierarchy of tools. We present here three codes that are presently used for the simulations of burning plasmas. At the first level there is a 0-dimensional code that allows to choose a reasonable range of global parameters; in our case the HELIOS code was used for this task. For the second level we have developed a mixed 0-D / 1-D code called METIS that allows to study the main properties of a burning plasma, including profiles and all heat and current sources, but always under the constraint of energy and other empirical scaling laws. METIS is a fast code that permits to perform a large number of runs (a run takes about one minute) and design the main features of a scenario, or validate the results of the 0-D code on a full time evolution. At the top level, we used the full 1D1/2 suite of codes CRONOS that gives access to a detailed study of the plasma profiles evolution. CRONOS can use a variety of modules for source terms and transport coefficients computation with different level of complexity and accuracy: from simple estimators to highly sophisticated physics calculations. Thus it is possible to vary the accuracy of burning plasma simulations, as a trade-off with computation time. A wide range of scenario studies can thus be made with CRONOS and then validated with post-processing tools like MHD stability analysis. We will present in this paper results of this multi-level analysis applied to the ITER hybrid scenario. This specific example will illustrate the importance of having several tools for the study of burning plasma scenarios, especially in a domain that present devices cannot access experimentally. (Author)

  3. Convective Weather Forecast Accuracy Analysis at Center and Sector Levels

    Wang, Yao; Sridhar, Banavar

    2010-01-01

    This paper presents a detailed convective forecast accuracy analysis at center and sector levels. The study is aimed to provide more meaningful forecast verification measures to aviation community, as well as to obtain useful information leading to the improvements in the weather translation capacity models. In general, the vast majority of forecast verification efforts over past decades have been on the calculation of traditional standard verification measure scores over forecast and observation data analyses onto grids. These verification measures based on the binary classification have been applied in quality assurance of weather forecast products at the national level for many years. Our research focuses on the forecast at the center and sector levels. We calculate the standard forecast verification measure scores for en-route air traffic centers and sectors first, followed by conducting the forecast validation analysis and related verification measures for weather intensities and locations at centers and sectors levels. An approach to improve the prediction of sector weather coverage by multiple sector forecasts is then developed. The weather severe intensity assessment was carried out by using the correlations between forecast and actual weather observation airspace coverage. The weather forecast accuracy on horizontal location was assessed by examining the forecast errors. The improvement in prediction of weather coverage was determined by the correlation between actual sector weather coverage and prediction. observed and forecasted Convective Weather Avoidance Model (CWAM) data collected from June to September in 2007. CWAM zero-minute forecast data with aircraft avoidance probability of 60% and 80% are used as the actual weather observation. All forecast measurements are based on 30-minute, 60- minute, 90-minute, and 120-minute forecasts with the same avoidance probabilities. The forecast accuracy analysis for times under one-hour showed that the errors in

  4. 24 CFR 10.16 - Adoption of a final rule.

    2010-04-01

    ... 24 Housing and Urban Development 1 2010-04-01 2010-04-01 false Adoption of a final rule. 10.16 Section 10.16 Housing and Urban Development Office of the Secretary, Department of Housing and Urban Development RULEMAKING: POLICY AND PROCEDURES Procedures § 10.16 Adoption of a final rule. All timely...

  5. Anthropometric, physical and cardiorespiratory fitness of 10-16 years children

    Indranil Manna; Swadesh Ranjan Pan; Mohua Chowdhury

    2014-01-01

    Objectives: The present study was undertaken to investigate the anthropometric, physical and cardiorespiratiory fitness of 10-16 yrs children. Background: Talent identification in sports is importance because they represent the achievement level of a particular group in future. There are very limited studies available in Indian context on talent identification in sports. Method: A total of 150 male children of 10-16 yrs age volunteered for this study; were divided equally into 3 groups (i) Pr...

  6. The Carmichael numbers up to $10^{16}$

    Pinch, Richard G. E.

    1998-01-01

    We extend our previous computations to show that there are 246683 Carmichael numbers up to $10^{16}$. As before, the numbers were generated by a back-tracking search for possible prime factorisations together with a ``large prime variation''. We present further statistics on the distribution of Carmichael numbers.

  7. Static beacons based indoor positioning method for improving room-level accuracy

    Miekk-oja, Ville

    2015-01-01

    Demand for indoor positioning applications has been growing lately. Indoor positioning is used for example in hospitals for patient tracking, and in airports for finding correct gates. Requirements in indoor positioning have become more strict with demands for a higher accuracy. This thesis presents a method for improving the room-level accuracy of a positioning system by using static beacons. As a static beacon, Bluetooth low energy modules will be used to test how much they can improve...

  8. Acceptance and Accuracy of Multiple Choice, Confidence-Level, and Essay Question Formats for Graduate Students

    Swartz, Stephen M.

    2006-01-01

    The confidence level (information-referenced testing; IRT) design is an attempt to improve upon the multiple choice format by allowing students to express a level of confidence in the answers they choose. In this study, the author evaluated student perceptions of the ease of use and accuracy of and general preference for traditional multiple…

  9. Study the effect of gray component replacement level on reflectance spectra and color reproduction accuracy

    Spiridonov, I.; Shopova, M.; Boeva, R.

    2013-03-01

    The aim of this study is investigation of gray component replacement (GCR) levels on reflectance spectrum for different overprints of the inks and color reproduction accuracy. The most commonly implemented method in practice for generation of achromatic composition is gray component replacement (GCR). The experiments in this study, have been performed in real production conditions with special test form generated by specialized software. The measuring of reflection spectrum of printed colors, gives a complete conception for the effect of different gray component replacement levels on color reproduction accuracy. For better data analyses and modeling of processes, we have calculated (converted) the CIEL*a*b* color coordinates from the reflection spectra data. The assessment of color accuracy by using different GCR amount has been made by calculation of color difference ΔE* ab. In addition for the specific printing conditions we have created ICC profiles with different GCR amounts. A comparison of the color gamuts has been performed. For a first time a methodology is implemented for examination and estimation of effect of GCR levels on color reproduction accuracy by studying a big number of colors in entire visible spectrum. Implementation in practice of the results achieved in this experiment, will lead to improved gray balance and better color accuracy. Another important effect of this research is reduction of financial costs of printing production by decreasing of ink consumption, indirect reduction of emissions during the manufacture of inks and facilitates the process of deinking during the recycling paper.

  10. The Influence of Overt Practice, Achievement Level, and Explanatory Style on Calibration Accuracy and Performance

    Bol, Linda; Hacker, Douglas J.; O'Shea, Patrick; Allen, Dwight

    2005-01-01

    The authors measured the influence of overt calibration practice, achievement level, and explanatory style on calibration accuracy and exam performance. Students (N = 356) were randomly assigned to either an overt practice or no-practice condition. Students in the overt practice condition made predictions and postdictions about their performance…

  11. Accuracy enhancement of the spherical actuator with a two-level geometric calibration method

    Zhang Liang; Chen Weihai; Liu Jingmeng; Wu Xingming; Chen I-Ming

    2014-01-01

    This paper presents a two-level geometric calibration method for the permanent magnet (PM) spherical actuator to improve its motion control accuracy. The proposed actuator is composed of a stator with circumferential coils and a rotor with multiple PM poles. Due to the assembly and fabrication errors, the real geometric parameters of the actuator will deviate from their design values. Hence, the identification of such errors is critical for the motion control tasks. A two-level geometric cali...

  12. Fluency and accuracy levels in writing of Grade 12 ESL learners

    Johann L Van der Walt

    2011-08-01

    Full Text Available This study investigated two aspects of the level of second language development achieved by Grade 12 English Second Language (ESL learners in South Africa. It was inspired by the general concern about standards in the matriculation examination and calls for the improvement of ESL teaching and learning. The study involved an investigation and description of the fluency and accuracy levels of Grade 12 learners. We focussed on writing, since it is generally accepted that characteristic patterns of advanced learners are best studied in written production. 216 compositions were analysed in terms of T-units, and fluency and accuracy frequencies and ratios were calculated. Results show that fluency ratios (W/T and W/EFT and an accuracy ratio (EFT/T paint a poor picture of learners’ performance in writing, and suggest that Grade 12 ESL learners are ill-prepared for tertiary study. Better control of morphology and syntax is required, as this will lead to a general improvement of fluency and accuracy levels in ESL.

  13. Static and dynamic modelling of liquid level sensor with high accuracy

    Fock, K. [Budapest Univ. of Technology and Economics, Budapest (Hungary). Dept. of Control Engineering and Information Technology; Fock, B. [Dept. of Measurement and Information Systems, Budapest Univ. of Technology and Economics, Budapest (Hungary)

    2001-07-01

    This category of continous level sensors is related to the float type. An angular-position transducer is used to indicate the number of turns of a dram as a plump line wound on the drum, is unwound until a weight (of gramble solids) or a float (for fluids) touch the surface. When this occurs the plump line loses tension, a tension sensor (force transducer) detects the loss in tension and sends signal to a direction-changing device, that controls a drum drive motor. Beyond the question of point or continous level control, operating variable play a major role in determing accuracy and repeatibility requirements. The paper contains the dynamic analysis and the identification of the sensor system to increase the static and dynamic accuracy. (orig.)

  14. Dissolution Of 3013-DE Sample 10-16

    The HB-Line Facility has a long-term mission to dissolve and disposition legacy fissile materials. HB-Line dissolves plutonium dioxide (PuO2) from K-Area parting support of the 3013 Destructive Examination (DE) program. The PuO2-bearing solids originate from a variety of unit operations and processing facilities, but all of the material is assumed to be high-fired (i.e., calcined in air for a minimum of two hours at (ge) 750 C). The Savannah River National Laboratory (SRNL) conducted dissolution flowsheet studies on 3013 DE Sample 10-16 (can R610826), which contains weapons-grade plutonium (Pu) as the fissile material. The dissolution flowsheet study was performed for 4 hours at 108 C on unwashed material using 12 M nitric acid (HNO3) containing 0.20 M potassium fluoride (KF). After 4 hours at 108 C, the 239Pu Equivalent concentration was 32.5 g/L (gamma, 5.0% uncertainty). The insoluble residue comprised 9.88 wt % of the initial bulk weight, and contained 5.31-5.95 wt % of the initial Pu. The residue contained Pu in the highest concentration, followed by tungsten (W). Analyses detected 2,770 mg/L chloride (Cl-) in the final dissolver solution (3.28 wt %), which is significantly lower than the amount of Cl- detected by prompt gamma (9.86 wt %) and the 3013 DE Surveillance program (14.7 wt %). A low bias in chloride measurement is anticipated due to volatilization during the experiment. Gas generation studies found approximately 60 mL of gas per gram of sample produced during the first 30 minutes of dissolution. Little to no gas was produced after the first 30 minutes. Hydrogen gas (H2) was not detected in the sample. Based on detection limits and accounting for dilution, the generated gas contained 2, which is well below the 4.0 vol % flammability limit for H2 in air. Filtration of the dissolver solution occurred readily. When aluminum nitrate nonahydrate (ANN) was added to the filtered dissolver solution at a 3:1 Al:F molar ratio, and stored at room temperature

  15. Accuracy enhancement of the spherical actuator with a two-level geometric calibration method

    Zhang Liang

    2014-04-01

    Full Text Available This paper presents a two-level geometric calibration method for the permanent magnet (PM spherical actuator to improve its motion control accuracy. The proposed actuator is composed of a stator with circumferential coils and a rotor with multiple PM poles. Due to the assembly and fabrication errors, the real geometric parameters of the actuator will deviate from their design values. Hence, the identification of such errors is critical for the motion control tasks. A two-level geometric calibration approach is proposed to identify such errors. In the first level, the calibration model is formulated based on the differential form of the kinematic equation, which is to identify the geometric errors in the spherical joint. In the second level, the calibration model is formulated based on the differential form of torque formula, which is to calibrate the geometric parameters of the magnetization axes of PM poles and coils axes. To demonstrate the robustness and availability of the calibration algorithm, simulations are conducted. The results have shown that the proposed two-level calibration method can effectively compensate the geometric parameter errors and improve the positioning accuracy of the spherical actuator.

  16. Diagnostic accuracy at several reduced radiation dose levels for CT imaging in the diagnosis of appendicitis

    Zhang, Di; Khatonabadi, Maryam; Kim, Hyun; Jude, Matilda; Zaragoza, Edward; Lee, Margaret; Patel, Maitraya; Poon, Cheryce; Douek, Michael; Andrews-Tang, Denise; Doepke, Laura; McNitt-Gray, Shawn; Cagnon, Chris; DeMarco, John; McNitt-Gray, Michael

    2012-03-01

    Purpose: While several studies have investigated the tradeoffs between radiation dose and image quality (noise) in CT imaging, the purpose of this study was to take this analysis a step further by investigating the tradeoffs between patient radiation dose (including organ dose) and diagnostic accuracy in diagnosis of appendicitis using CT. Methods: This study was IRB approved and utilized data from 20 patients who underwent clinical CT exams for indications of appendicitis. Medical record review established true diagnosis of appendicitis, with 10 positives and 10 negatives. A validated software tool used raw projection data from each scan to create simulated images at lower dose levels (70%, 50%, 30%, 20% of original). An observer study was performed with 6 radiologists reviewing each case at each dose level in random order over several sessions. Readers assessed image quality and provided confidence in their diagnosis of appendicitis, each on a 5 point scale. Liver doses at each case and each dose level were estimated using Monte Carlo simulation based methods. Results: Overall diagnostic accuracy varies across dose levels: 92%, 93%, 91%, 90% and 90% across the 100%, 70%, 50%, 30% and 20% dose levels respectively. And it is 93%, 95%, 88%, 90% and 90% across the 13.5-22mGy, 9.6-13.5mGy, 6.4-9.6mGy, 4-6.4mGy, and 2-4mGy liver dose ranges respectively. Only 4 out of 600 observations were rated "unacceptable" for image quality. Conclusion: The results from this pilot study indicate that the diagnostic accuracy does not change dramatically even at significantly reduced radiation dose.

  17. Temperature and pressure effects on capacitance probe cryogenic liquid level measurement accuracy

    Edwards, Lawrence G.; Haberbusch, Mark

    1993-01-01

    The inaccuracies of liquid nitrogen and liquid hydrogen level measurements by use of a coaxial capacitance probe were investigated as a function of fluid temperatures and pressures. Significant liquid level measurement errors were found to occur due to the changes in the fluids dielectric constants which develop over the operating temperature and pressure ranges of the cryogenic storage tanks. The level measurement inaccuracies can be reduced by using fluid dielectric correction factors based on measured fluid temperatures and pressures. The errors in the corrected liquid level measurements were estimated based on the reported calibration errors of the temperature and pressure measurement systems. Experimental liquid nitrogen (LN2) and liquid hydrogen (LH2) level measurements were obtained using the calibrated capacitance probe equations and also by the dielectric constant correction factor method. The liquid levels obtained by the capacitance probe for the two methods were compared with the liquid level estimated from the fluid temperature profiles. Results show that the dielectric constant corrected liquid levels agreed within 0.5 percent of the temperature profile estimated liquid level. The uncorrected dielectric constant capacitance liquid level measurements deviated from the temperature profile level by more than 5 percent. This paper identifies the magnitude of liquid level measurement error that can occur for LN2 and LH2 fluids due to temperature and pressure effects on the dielectric constants over the tank storage conditions from 5 to 40 psia. A method of reducing the level measurement errors by using dielectric constant correction factors based on fluid temperature and pressure measurements is derived. The improved accuracy by use of the correction factors is experimentally verified by comparing liquid levels derived from fluid temperature profiles.

  18. DISSOLUTION OF 3013-DE SAMPLE 10-16

    Taylor-Pashow, K.

    2011-05-24

    The HB-Line Facility has a long-term mission to dissolve and disposition legacy fissile materials. HB-Line dissolves plutonium dioxide (PuO{sub 2}) from K-Area parting support of the 3013 Destructive Examination (DE) program. The PuO{sub 2}-bearing solids originate from a variety of unit operations and processing facilities, but all of the material is assumed to be high-fired (i.e., calcined in air for a minimum of two hours at {ge} 750 C). The Savannah River National Laboratory (SRNL) conducted dissolution flowsheet studies on 3013 DE Sample 10-16 (can R610826), which contains weapons-grade plutonium (Pu) as the fissile material. The dissolution flowsheet study was performed for 4 hours at 108 C on unwashed material using 12 M nitric acid (HNO{sub 3}) containing 0.20 M potassium fluoride (KF). After 4 hours at 108 C, the {sup 239}Pu Equivalent concentration was 32.5 g/L (gamma, 5.0% uncertainty). The insoluble residue comprised 9.88 wt % of the initial bulk weight, and contained 5.31-5.95 wt % of the initial Pu. The residue contained Pu in the highest concentration, followed by tungsten (W). Analyses detected 2,770 mg/L chloride (Cl{sup -}) in the final dissolver solution (3.28 wt %), which is significantly lower than the amount of Cl{sup -} detected by prompt gamma (9.86 wt %) and the 3013 DE Surveillance program (14.7 wt %). A low bias in chloride measurement is anticipated due to volatilization during the experiment. Gas generation studies found approximately 60 mL of gas per gram of sample produced during the first 30 minutes of dissolution. Little to no gas was produced after the first 30 minutes. Hydrogen gas (H{sub 2}) was not detected in the sample. Based on detection limits and accounting for dilution, the generated gas contained < 0.12 vol % H{sub 2}, which is well below the 4.0 vol % flammability limit for H{sub 2} in air. Filtration of the dissolver solution occurred readily. When aluminum nitrate nonahydrate (ANN) was added to the filtered dissolver

  19. Accuracy of different abutment level impression techniques in All-On-4 dental implants

    Marzieh Alikhasi

    2012-01-01

    Full Text Available Background and Aims: Passive fit of prosthetic frameworks is a major concern in implant dentistry. Impression technique is one of the several variables that may affect the outcome of dental implants. The purpose of this study was to compare the three dimensional accuracy of direct and indirect abutment level implant impressions ofALL-ON-4 treatment plan.Materials and Methods: A reference acrylic resin model with four Branemark fixtures was made according to All-On-4 treatment plan. Multiunit abutments were screwed into the fixtures and two special trays were made for direct and indirect impression techniques. Ten direct and ten indirect impression techniques with respective impression transfers were made. Impressions were poured with stone and the positional accuracy of the abutment analogues in each dimension of x, y, and z axes and also angular displacement (Δθ were evaluated using a Coordinate Measuring Machine (CMM. Data were analyzed using T- test.Results: The results showed that direct impression technique was significantly more accurate than indirect technique (P<0.001.Conclusion: The results showed that the accuracy of direct impression technique was significantly more than that of indirect technique in Δθ and Δr coordinate and also Δx, Δy, Δz.

  20. Accuracy of Self-Reported College GPA: Gender-Moderated Differences by Achievement Level and Academic Self-Efficacy

    Caskie, Grace I. L.; Sutton, MaryAnn C.; Eckhardt, Amanda G.

    2014-01-01

    Assessments of college academic achievement tend to rely on self-reported GPA values, yet evidence is limited regarding the accuracy of those values. With a sample of 194 undergraduate college students, the present study examined whether accuracy of self-reported GPA differed based on level of academic performance or level of academic…

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

    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.

  2. Nano-level instrumentation for analyzing the dynamic accuracy of a rolling element bearing

    The rotational performance of high-precision rolling bearings is fundamental to the overall accuracy of complex mechanical systems. A nano-level instrument to analyze rotational accuracy of high-precision bearings of machine tools under working conditions was developed. In this instrument, a high-precision (error motion < 0.15 μm) and high-stiffness (2600 N axial loading capacity) aerostatic spindle was applied to spin the test bearing. Operating conditions could be simulated effectively because of the large axial loading capacity. An air-cylinder, controlled by a proportional pressure regulator, was applied to drive an air-bearing subjected to non-contact and precise loaded axial forces. The measurement results on axial loading and rotation constraint with five remaining degrees of freedom were completely unconstrained and uninfluenced by the instrument's structure. Dual capacity displacement sensors with 10 nm resolution were applied to measure the error motion of the spindle using a double-probe error separation method. This enabled the separation of the spindle's error motion from the measurement results of the test bearing which were measured using two orthogonal laser displacement sensors with 5 nm resolution. Finally, a Lissajous figure was used to evaluate the non-repetitive run-out (NRRO) of the bearing at different axial forces and speeds. The measurement results at various axial loadings and speeds showed the standard deviations of the measurements’ repeatability and accuracy were less than 1% and 2%. Future studies will analyze the relationship between geometrical errors and NRRO, such as the ball diameter differences of and the geometrical errors in the grooves of rings

  3. Soft mean spherical approximation for dusty plasma liquids: Level of accuracy and analytic expressions

    Tolias, P. [Space and Plasma Physics, Royal Institute of Technology, Stockholm SE-100 44 (Sweden); Istituto Nazionale di Fisica Nucleare (INFN), Sezione di Napoli, Naples 80126 (Italy); Ratynskaia, S. [Space and Plasma Physics, Royal Institute of Technology, Stockholm SE-100 44 (Sweden); Angelis, U. de [Istituto Nazionale di Fisica Nucleare (INFN), Sezione di Napoli, Naples 80126 (Italy)

    2015-08-15

    The soft mean spherical approximation is employed for the study of the thermodynamics of dusty plasma liquids, the latter treated as Yukawa one-component plasmas. Within this integral theory method, the only input necessary for the calculation of the reduced excess energy stems from the solution of a single non-linear algebraic equation. Consequently, thermodynamic quantities can be routinely computed without the need to determine the pair correlation function or the structure factor. The level of accuracy of the approach is quantified after an extensive comparison with numerical simulation results. The approach is solved over a million times with input spanning the whole parameter space and reliable analytic expressions are obtained for the basic thermodynamic quantities.

  4. Soft mean spherical approximation for dusty plasma liquids: Level of accuracy and analytic expressions

    The soft mean spherical approximation is employed for the study of the thermodynamics of dusty plasma liquids, the latter treated as Yukawa one-component plasmas. Within this integral theory method, the only input necessary for the calculation of the reduced excess energy stems from the solution of a single non-linear algebraic equation. Consequently, thermodynamic quantities can be routinely computed without the need to determine the pair correlation function or the structure factor. The level of accuracy of the approach is quantified after an extensive comparison with numerical simulation results. The approach is solved over a million times with input spanning the whole parameter space and reliable analytic expressions are obtained for the basic thermodynamic quantities

  5. Accuracy assessment of airphoto interpretation of vegetation types and disturance levels on winter seismic trails, Arctic National Wildlife Refuge, Alaska

    US Fish and Wildlife Service, Department of the Interior — An accuracy assessment was conducted to evaluate the photointerpretation of vegetation types and disturbance levels along seismic trails in the Arctic National...

  6. Accuracy assessment of airphoto interpretation of vegetation types and disturance levels on winter seismic trails, Arctic National Wildlife Refuge, Alaska

    US Fish and Wildlife Service, Department of the Interior — An accuracy assessment was conducted to evaluate the photo-interpretation of vegetation types and disturbance levels along seismic trails in the Arctic National...

  7. Automated Algorithms for Quantum-Level Accuracy in Atomistic Simulations: LDRD Final Report.

    Thompson, Aidan P.; Schultz, Peter A.; Crozier, Paul; Moore, Stan Gerald; Swiler, Laura Painton; Stephens, John Adam; Trott, Christian Robert; Foiles, Stephen M.; Tucker, Garritt J. (Drexel University)

    2014-09-01

    This report summarizes the result of LDRD project 12-0395, titled %22Automated Algorithms for Quantum-level Accuracy in Atomistic Simulations.%22 During the course of this LDRD, we have developed an interatomic potential for solids and liquids called Spectral Neighbor Analysis Poten- tial (SNAP). The SNAP potential has a very general form and uses machine-learning techniques to reproduce the energies, forces, and stress tensors of a large set of small configurations of atoms, which are obtained using high-accuracy quantum electronic structure (QM) calculations. The local environment of each atom is characterized by a set of bispectrum components of the local neighbor density projected on to a basis of hyperspherical harmonics in four dimensions. The SNAP coef- ficients are determined using weighted least-squares linear regression against the full QM training set. This allows the SNAP potential to be fit in a robust, automated manner to large QM data sets using many bispectrum components. The calculation of the bispectrum components and the SNAP potential are implemented in the LAMMPS parallel molecular dynamics code. Global optimization methods in the DAKOTA software package are used to seek out good choices of hyperparameters that define the overall structure of the SNAP potential. FitSnap.py, a Python-based software pack- age interfacing to both LAMMPS and DAKOTA is used to formulate the linear regression problem, solve it, and analyze the accuracy of the resultant SNAP potential. We describe a SNAP potential for tantalum that accurately reproduces a variety of solid and liquid properties. Most significantly, in contrast to existing tantalum potentials, SNAP correctly predicts the Peierls barrier for screw dislocation motion. We also present results from SNAP potentials generated for indium phosphide (InP) and silica (SiO 2 ). We describe efficient algorithms for calculating SNAP forces and energies in molecular dynamics simulations using massively parallel

  8. Accuracy Assessments of ATMS Upper-Level Temperature Sounding Channels Using COSMIC RO Data

    Lin, L.; Weng, F.; Zou, X.

    2012-12-01

    The Advanced Technology Microwave Sounder (ATMS) on board Suomi National Polar-orbiting Partnership (NPP) is a 22-channel passive microwave radiometer that can provide high-spatial-resolution data for generating temperature and moisture soundings in cloudy conditions. Global Positioning System (GPS) radio occultation (RO) data have high vertical resolution, are not affected by clouds, and are most accurate from 8 to 30 km, making them ideally suited for estimating the precision of ATMS measurements for upper level temperature sounding channels. In this study, Constellation Observing System for Meteorology, Ionosphere, and Climate (COSMIC) RO data are collocated with ATMS observation from December 10, 2011 to June 30, 2012. Compared with GPS simulations using the U.S. Joint Center of Satellite Data Assimilation (JCSDA) Community Radiative Transfer Model (CRTM), the global biases of brightness temperatures from ATMS measurements are within 0.5K for channels 6 to 13 for clear-sky data over ocean. This value is well within the pre-launch specification, indicating that the ATMS upper level temperature sounding channels have high accuracy. The monthly variation and angular dependence of ATMS bias are also examined.

  9. Image accuracy and representational enhancement through low-level, multi-sensor integration techniques

    Baker, J.E.

    1994-09-01

    Multi-Sensor Integration (MSI) is the combining of data and information from more than one source in order to generate a more reliable and consistent representation of the environment. The need for MSI derives largely from basic ambiguities inherent in our current sensor imaging technologies. These ambiguities exist as long as the mapping from reality to image is not 1-to-1. That is, if different {open_quotes}realities{close_quotes} lead to identical images, a single image cannot reveal the particular reality which was the truth. MSI techniques attempt to resolve some of these ambiguities by appropriately coupling complementary images to eliminate possible inverse mappings. What constitutes the best MSI technique is dependent on the given application domain, available sensors, and task requirements. MSI techniques can be divided into three categories based on the relative information content of the original images with that of the desired representation: (1) {open_quotes}detail enhancement,{close_quotes} wherein the relative information content of the original images is less rich than the desired representation; (2) {open_quotes}data enhancement,{close_quotes} wherein the MSI techniques are concerned with improving the accuracy of the data rather than either increasing or decreasing the level of detail; and (3) {open_quotes}conceptual enhancement,{close_quotes} wherein the image contains more detail than is desired, making it difficult to easily recognize objects of interest. In conceptual enhancement one must group pixels corresponding to the same conceptual object and thereby reduce the level of extraneous detail.

  10. Screening accuracy of Level 2 autism spectrum disorder rating scales. A review of selected instruments.

    Norris, Megan; Lecavalier, Luc

    2010-07-01

    The goal of this review was to examine the state of Level 2, caregiver-completed rating scales for the screening of Autism Spectrum Disorders (ASDs) in individuals above the age of three years. We focused on screening accuracy and paid particular attention to comparison groups. Inclusion criteria required that scales be developed post ICD-10, be ASD-specific, and have published evidence of diagnostic validity in peer-reviewed journals. The five scales reviewed were: the Social Communication Questionnaire (SCQ), Gilliam Autism Rating Scale/Gilliam Autism Rating Scale-Second Edition (GARS/GARS-2), Social Responsiveness Scale (SRS), Autism Spectrum Screening Questionnaire (ASSQ), and Asperger Syndrome Diagnostic Scale (ASDS). Twenty total studies were located, most examining the SCQ. Research on the other scales was limited. Comparisons between scales were few and available evidence of diagnostic validity is scarce for certain subpopulations (e.g., lower functioning individuals, PDDNOS). Overall, the SCQ performed well, the SRS and ASSQ showed promise, and the GARS/GARS-2 and ASDS demonstrated poor sensitivity. This review indicates that Level 2 ASD caregiver-completed rating scales are in need of much more scientific scrutiny. PMID:20591956

  11. Education Level Predicts Retrospective Metamemory Accuracy in Healthy Aging and Alzheimer’s Disease

    Szajer, Jacquelyn; Murphy, Claire

    2013-01-01

    The current study investigated the effect of education on retrospective metamemory accuracy in 143 healthy older adults and 143 early to moderate AD patients, using retrospective measures of confidence in the accuracy of retrieval responses in an episodic odor recognition memory task. Relative confidence accuracy was computed as the difference between confidence judgments for correct and incorrect responses. In both AD patients and controls, individuals reporting 17 years of education or more...

  12. Image accuracy and representational enhancement through low-level, multi-sensor integration techniques

    Multi-Sensor Integration (MSI) is the combining of data and information from more than one source in order to generate a more reliable and consistent representation of the environment. The need for MSI derives largely from basic ambiguities inherent in our current sensor imaging technologies. These ambiguities exist as long as the mapping from reality to image is not 1-to-1. That is, if different 44 realities'' lead to identical images, a single image cannot reveal the particular reality which was the truth. MSI techniques can be divided into three categories based on the relative information content of the original images with that of the desired representation: (1) ''detail enhancement,'' wherein the relative information content of the original images is less rich than the desired representation; (2) ''data enhancement,'' wherein the MSI techniques axe concerned with improving the accuracy of the data rather than either increasing or decreasing the level of detail; and (3) ''conceptual enhancement,'' wherein the image contains more detail than is desired, making it difficult to easily recognize objects of interest. In conceptual enhancement one must group pixels corresponding to the same conceptual object and thereby reduce the level of extraneous detail. This research focuses on data and conceptual enhancement algorithms. To be useful in many real-world applications, e.g., autonomous or teleoperated robotics, real-time feedback is critical. But, many MSI/image processing algorithms require significant processing time. This is especially true of feature extraction, object isolation, and object recognition algorithms due to their typical reliance on global or large neighborhood information. This research attempts to exploit the speed currently available in state-of-the-art digitizers and highly parallel processing systems by developing MSI algorithms based on pixel rather than global-level features

  13. Experimental Investigation of Liquid-Level Measuring Accuracy in a Low Pressure Environment

    Dip Tubes which are used for determining liquid level in many processes at SRS will be used to measure the liquid level of the Am/Cm solution in the Feed Tank at the MPPF. The Feed Tank operates under a vacuum, therefore the Dip Tubes will operate under a vacuum. Uncertainty in how accurate the Dip Tubes would perform in a vacuum environment led to testing. The Am/Cm Melter Liquid-Feed Tank measurement test was mocked-up per Figure 1. The Feed Tank was designed to simulate actual conditions in which the Dip Tubes would measure the differential pressure. The Feed Tank was made of Stainless Steel with a Lexan window to view inside the tank during testing. The Feed Tank was built per Drawing SRT-ETF-DD-96008, Revision A. The accuracy of the Dip Tubes was checked first by filling the Feed Tank at a flow rate of 3.5 L/min and venting it to the atmosphere. Figure 2 shows that the Dip Tubes were responsive and accurate when compared to the data from the measuring scale on the view window. Then tests were conducted with 23y Hg vacuum inside the tank and water flow rates of 3.9 L/min, 1.8 L/min, and 0.7 L/min being fed to the tank. The data from each test are depicted in Figure 3, Figure 4, and Figure 5, respectively. The Dip Tubes responded accurately for the three test with a maximum error range of +0.31y to -0.19y when compared to the measuring scale located next to the view window on the Feed Tank

  14. Improving The Accuracy Of Bluetooth Based Travel Time Estimation Using Low-Level Sensor Data

    Araghi, Bahar Namaki; Tørholm Christensen, Lars; Krishnan, Rajesh;

    2013-01-01

    Bluetooth sensors have a large detection zone compared to other static Vehicle Re-Identification Systems (VRIS). Although a larger detection zone increases the probability of detecting a Bluetooth-enabled device in a fast-moving vehicle, it increases the probability of multiple detection events...... triggered by a single device. This could lead to location ambiguity and reduced accuracy of travel time estimation. Therefore, the accuracy of travel time estimations by Bluetooth Technology (BT) depends upon how location ambiguity is handled by the estimation method. The issue of multiple detection events...

  15. Accuracy of low-level tritium measurements in water samples by liquid scintillation method

    Quenching is always present in water samples and the degree of quenching can vary from one sample to another even within the same batch. This means that quench correction should be carried out for each sample in order to determine the activity so that comparisons can be made between samples and other batches. A comparative study of tritium measurements between two methods used to correct for quenching is presented in this paper. The methods used to determine counting efficiency in the presence of quenching are as follow: Spectral Quench Parameter of External standard method (SQP(E)) and Internal Standard Method (ISM). In this work, a low background liquid scintillation system detector (Quantulus 1220) is used to determine tritium activity concentration in heavy water with different concentrations from 99.66 D/H+D% to 1.65 D/D+H %. Standard calibration curve for the SQP(E) technique was carried out with 3 H low level quenched PACKARD standard set that had an assayed value of 29240 dpm/std ± 1.6%. Quench correction for Internal Standard Method was made for each sample of heavy water with Tritiated Water Internal Standard that had a tritium concentration of 2.51 x 106 dpm/g ± 3.0%. A comparison between dilution factors calculated for D/D + H% concentration and dilution factors calculated for tritium activity measured by the two methods, is presented in the paper. Internal Standard Method provides accuracy results especially for lower D/D+H% concentration, which are similar with environmental sample. Commercial standards set do not fulfill the requirements of an accurate environmental tritium measurement. One must take into account also the following circumstances: type of vial, type of scintillation cocktail, filled volume and counting geometry. Even if one can make its own standard set for quenching calibration one must cope also with another problem. The Compton electrons produced by external standard are beta energetic particles in the sample itself. Hence a

  16. The First Comprehensive Accuracy Assessment of GlobeLand30 at a National Level: Methodology and Results

    Maria Antonia Brovelli

    2015-04-01

    Full Text Available As result of the “Global Land Cover Mapping at Finer Resolution” project led by National Geomatics Center of China (NGCC, one of the first global land cover datasets at 30-meters resolution (GlobeLand30 has been produced for the years 2000 and 2010. The first comprehensive accuracy assessment at a national level of these data (excluding some comparisons in China has been performed on the Italian area by means of a benchmarking with the more detailed land cover datasets available for some Italian regions. The accuracy evaluation was based on the cell-by-cell comparison between Italian maps and the GlobeLand30 in order to obtain the confusion matrix and its derived statistics (overall accuracy, allocation and quantity disagreements, user and producer accuracy, which help to understand the classification quality. This paper illustrates the adopted methodology and procedures for assessing GlobeLand30 and reports the obtained statistics. The analysis has been performed in eight regions across Italy and shows very good results: the comparison of the datasets according to the first level of Corine Land Cover nomenclature highlights overall accuracy values generally higher than 80%.

  17. On the Accuracy of Iranian EFL Students' Reading Self-assessment and their Level of Reading Proficiency

    Moein Shokr

    2015-01-01

    Reviewing the literature on self-assessment as an alternative method of assessment we find advocates claiming for the accuracy of the students’ self-assessments in general with little focus on their level of proficiency. With an eye on the students’ level of reading proficiency, the present study aimed at investigating the relationship between students’ reading self-assessment (as a formative and alternative method of assessment) on the one hand, and teacher assessment (as a formative type of...

  18. Accuracy of student performance while reading leveled books rated at their instructional level by a reading inventory.

    Burns, Matthew K; Pulles, Sandra M; Maki, Kathrin E; Kanive, Rebecca; Hodgson, Jennifer; Helman, Lori A; McComas, Jennifer J; Preast, June L

    2015-12-01

    Identifying a student's instructional level is necessary to ensure that students are appropriately challenged in reading. Informal reading inventories (IRIs) purport to assess the highest reading level at which a student can accurately decode and comprehend text. However, the use of IRIs in determining a student's instructional level has been questioned because of a lack of research. The current study examined the percentage of words read correctly with 64 second- and third-grade students while reading from texts at their instructional level as determined by an IRI. Students read for 1 min from three leveled texts that corresponded to their instructional level as measured by an IRI, and the percentage of words read correctly was recorded. The percentage read correctly correlated across the three books from r=.47 to r=.68 and instructional level categories correlated from tau=.59 to tau=.65. Percent agreement calculations showed that the categorical scores (frustration, instructional, and independent) for the three readings agreed approximately 67% to 70% of the time, which resulted in a kappa estimate of less than .50. Kappa coefficients of .70 are considered strong indicators of agreement. Moreover, more than half of the students with the lowest reading skills read at a frustration level when attempting to read books rated at their instructional level by an IRI. The current study questions how reliably and accurately IRIs identify students' instructional level for reading. PMID:26563597

  19. 46 CFR 31.10-16 - Inspection and certification of cargo gear-TB/ALL.

    2010-10-01

    ... 46 Shipping 1 2010-10-01 2010-10-01 false Inspection and certification of cargo gear-TB/ALL. 31.10... CERTIFICATION Inspections § 31.10-16 Inspection and certification of cargo gear—TB/ALL. (a) The owner, operator... treatment of chains, rings, hooks, shackles, and swivels which require such treatment; and,...

  20. High-level politically connected firms, corruption, and analyst forecast accuracy around the world

    Charles JP Chen; Yuan Ding; Chansog (Francis) Kim

    2010-01-01

    The international business (IB) literature has widely recognized political forces as major factors that complicate the strategic decisions of multinational enterprises (MNEs). Analyses by financial intermediaries can help to reduce the risk of information asymmetry caused by such factors. Using firm-level data from 17 jurisdictions between 1997 and 2001, this study investigates the association between a firm's high-level political connections and earnings forecasts made by financial analysts,...

  1. Blood CEA levels for detecting recurrent colorectal cancer: A Diagnostic Test Accuracy Review.

    Nicholson, BD; Shinkins, B.; Pathiraja, I; Roberts, NW; James, T; Mallett, S.; Perera, R; Primrose, JN; Mant, D

    2015-01-01

    Background Testing for carcino-embryonic antigen (CEA) in the blood is a recommended part of follow-up to detect recurrence of colorectal cancer following primary curative treatment. There is substantial clinical variation in the cut-off level applied to trigger further investigation. Objectives To determine the diagnostic performance of different blood CEA levels in identifying people with colorectal cancer recurrence in order to inform clinical practice. Search methods W...

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

    Guanyi Sun; Shengnan Xu; Xu Wang; Dawei Wang; Eugene Tang; Yangdong Deng; Sun Chan

    2011-01-01

    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 simu...

  3. Determination of accuracy level elements of Co, Ni, Cr, Cu in SRM using the multi element method by AAS

    In nature, all elements are associated with the other element forming minerals in rocks. Minerals are formed by element with similar characteristics and inclined existence together. The element analysis of the rock samples there is matrix element (the other domineer element with similar characteristics) it can influent the result analysis so that cause deviation. The multi element method is the standard in surpassing deviation caused by matrix element influences. The multi element method is the one of standard method which used in Sub Division of Geochemical Exploration, that never be done any test the result analysis before. The research aim to test the accuracy level of the result analysis for multi element method for Co, Ni, Cr, Cu elements in six samples of SRM with AAS. The result analysis of multi element method by Atomic Absorption Spectroscopy, got the level accuracy about Co 89,98%-92,93%, Ni 90,13%-92,82%, Cr 89,71-95,38%, Cu 90,09%-92,82% with average deviation is <10%. Testing results of the analysis with student t Co element, Ni, Cr there is no significant difference / identical to SRM with 95% confidence level and Cu there are significant differences with the SRM 99% confidence level, the low deviations prove that the materials, equipment, and human resources, in a good condition fit for use in element analysis. (author)

  4. The Effect of Coded and Uncoded Written Corrective Feedback on the Accuracy of Learners Writing in Pre-intermediate Level

    Asghar Salimi

    2015-05-01

    Full Text Available To date, conflict exists in the literature on whether or not and how teachers should react to EFL learners' written grammar errors. Coded versus uncoded corrective feedback has been one of the rarely explored areas of investigation in SLA. To shed light on the factors that may explain such conflicting results, this study investigated the effect of coded and un-coded written corrective feedback with regard to possible improvements in the accuracy in writing of pre-intermediate EFL learners. It, further, sought whether such an effect would last in the long run. In the course of 14 weeks, learners’ errors in 2 groups (i.e., coded and uncoded were reacted. A paired-samples t-test was run to analyze the obtained data. Analysis of the written pieces in the immediate post-test and delayed post test revealed that coded corrective feedback, compared to the uncoded group, had a significantly more positive influence on learners' accuracy improvement both in the short and in the long run. The findings imply that teachers should weigh the learners' abilities and interlanguage, proficiency level, and type of error before applying different feedback types. Moreover, the implications are discussed in terms of effective guidelines for teaching writing in EFL contexts.Keywords: written feedback, accuracy, EFL context

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

    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.

  6. On the Accuracy of Iranian EFL Students' Reading Self-assessment and their Level of Reading Proficiency

    Moein Shokr

    2015-10-01

    Full Text Available Reviewing the literature on self-assessment as an alternative method of assessment we find advocates claiming for the accuracy of the students’ self-assessments in general with little focus on their level of proficiency. With an eye on the students’ level of reading proficiency, the present study aimed at investigating the relationship between students’ reading self-assessment (as a formative and alternative method of assessment on the one hand, and teacher assessment (as a formative type of assessment as well as students’ final examination scores (as a summative and traditional method of assessment on the other. To this end, 65 students of Islamic Azad University- Tehran South Branch were selected to participate in this study. Initially, participants received PET test as pretest for assigning them into different levels of reading proficiency. Based upon the results of the pretest, participants were assigned to elementary and intermediate levels. Throughout the whole semester self-assessment questionnaire was employed for five times. Descriptive statistics and Pearson correlation were the data analysis techniques performed. The results of the study revealed a significant relationship between the intermediate learners’ self-ratings and teacher assessments; however, the results indicated no significant relationship between elementary learners’ self-assessments and teacher assessments. Also, the correlations between students’ self-assessments and their final examination scores were not significant for both levels. Therefore, given the teacher assessment as the yardstick, the accuracy of the intermediate levels and the inaccuracy of the elementary learners’ self-assessments could be concluded. Finally, the low correlation between the learners’ self-assessments and their scores on traditional final examination led the researcher to attribute it to the different nature of these two assessment types.

  7. Accuracy of a 2-level scheme based on a subgroup method for pressurized water reactor fuel assembly models

    Highlights: • A 2-level computational scheme is developed and implemented in the DRAGON5 lattice code. • The first level is using a self-shielding method based on the Subgroup Projection Method with 295 energy groups. • A SALOME-generated geometry is used for the second level. • The neutron flux of the second level is obtained using the Method of Characteristics with 26 energy groups. • Zero-burnup and depletion-dependent validation is made with respect to Monte Carlo code SERPENT2. - Abstract: Until now, a typical computational scheme for the DRAGON5 lattice code was based on a resonance self-shielding method using the Subgroup Projection Method (SPM) coupled with a flux calculation using the Method of Characteristics (MOC), both solved over a 295-group Santamarina–Hfaiedh energy mesh (SHEM). We are investigating the accuracy of an optimized 2-level computational scheme based on a condensation stage from 295 to 26 energy groups. A first level flux calculation is performed using the Interface Current (IC) method on the 295-group mesh, followed by a detailed second level flux calculation using the MOC on the 26-group mesh. Here, we validate the 2-level scheme by comparison with the 1-level scheme and with Monte Carlo calculations at burnup 0 and with isotopic depletion. Validation results were obtained using Monte Carlo codes SERPENT2 and TRIPOLI4. This study shows that an optimized 2-level scheme is much faster than the corresponding 1-level scheme and leads to numerical results without a significant degradation in term of precision. The proposed 2-level schemes are therefore candidate for CPU-efficient production tools for generating multi-parameter reactor databases

  8. Primordial black holes with mass $10^{16}-10^{17}$ g and reionization of the Universe

    Belotsky, K M

    2014-01-01

    Primordial black holes (PBHs) with mass $10^{16}-10^{17}$ g almost escape constraints from observations so could essentially contribute to dark matter density. Hawking evaporation of such PBHs produces with a steady rate $\\gamma$- and $e^{\\pm}$-radiations in MeV energy range, which can be absorbed by ordinary matter. Simplified estimates show that a small fraction of evaporated energy had to be absorbed by baryonic matter what can turn out to be enough to heat the matter so it is fully ionized at the redshift $z\\sim 5\\ldots 10$. The result is found to be close to a borderline case where the effect appears, what makes it sensitive to the approximation used. In our approximation, degree of gas ionization reaches 50-100\\% by $z\\sim 5$ for PBH mass $(3\\ldots7)\\times 10^{16}$ g with their abundance corresponding to the upper limit.

  9. Investigation of factors influencing the accuracy of uranium enrichment level determination by multi- analysis method (MGAU)

    Statistical characteristics of multi-group analysis technique for isotopic composition determination of uranium samples, realised in the form of portable 'U-Pu InSpector' spectrometry system and MGAU V.1.0 code, have been studied with the help of uranium isotopic standard reference materials in the range 0.32 - 4.5 % of 235U and 0.004 - 0.036 % of 234U concentration. The influence of a number of factors that cause systematic bias of measured values are also studied. Obtained results reveal dependence of measured 235U enrichment level upon isotopic composition of uranium sample and geometry of the measurement. Systematic underestimation of measured 234U content turned out to be of about 23 % in the concentration range. Possible sources of revealed systematic biases are discussed as well as some recommendations for improving of MGAU code are given

  10. Estimation of background noise level on seismic station using statistical analysis for improved analysis accuracy

    Han, S. M.; Hahm, I.

    2015-12-01

    We evaluated the background noise level of seismic stations in order to collect the observation data of high quality and produce accurate seismic information. Determining of the background noise level was used PSD (Power Spectral Density) method by McNamara and Buland (2004) in this study. This method that used long-term data is influenced by not only innate electronic noise of sensor and a pulse wave resulting from stabilizing but also missing data and controlled by the specified frequency which is affected by the irregular signals without site characteristics. It is hard and inefficient to implement process that filters out the abnormal signal within the automated system. To solve these problems, we devised a method for extracting the data which normally distributed with 90 to 99% confidence intervals at each period. The availability of the method was verified using 62-seismic stations with broadband and short-period sensors operated by the KMA (Korea Meteorological Administration). Evaluation standards were NHNM (New High Noise Model) and NLNM (New Low Noise Model) published by the USGS (United States Geological Survey). It was designed based on the western United States. However, Korean Peninsula surrounded by the ocean on three sides has a complicated geological structure and a high population density. So, we re-designed an appropriate model in Korean peninsula by statistically combined result. The important feature is that secondary-microseism peak appeared at a higher frequency band. Acknowledgements: This research was carried out as a part of "Research for the Meteorological and Earthquake Observation Technology and Its Application" supported by the 2015 National Institute of Meteorological Research (NIMR) in the Korea Meteorological Administration.

  11. Model-based correction algorithms improving the accuracy of hydrostatic level measurement on pressure vessels

    It is important to possess precise process information for an optimised valuation of the plant process conditions. Especially these information have a great priority as well as for the emergency operation and post accident management. The rapid and great transitions resulting from that are hardly to master by the used measuring devices. Spurious indications can occur the cause of which could be a modification of design conditions, specific transients of process and the damage of the measuring instrument itself respectively during accidents. Further more it would be desirable to get additional not measurable state variables in this situation. For solving those problems modern methods and procedures of process identification, parameter identification and plausibility analysis comprising correction algorithms become more and more important. These modern methods are used to solve the following problems - diagnosis of the process state on the basis of combination by measuring variables, analytical redundancy and linguistic declarations, - reconstruction of not directly measurable variables and parameters respectively - detection and identification of process faults and instrumentation faults (diagnosis) - reconfiguration of measuring signals (correction). The reconstruction of process state is thus a combination of measured quantity, reconstructed state variables and analytical redundancy using model-based measuring methods. The use of model based measuring methods has been investigated on the example of hydrostatic level measurement on horizontal steam generators. The results of experiments on pilot plants as well as comparison with calculations of empowered programs for instants ATHLET and methods of parameter identification serve as a verification of methods and algorithms, which were developed. This paper describe the main facts of this work

  12. Evaluation of the Diagnostic Accuracy of Serum D-Dimer Levels in Pregnant Women with Adnexal Torsion

    Hasan Onur Topçu

    2015-01-01

    Full Text Available We aimed to evaluate the diagnostic accuracy of serum D-dimer levels in pregnant women with adnexal torsion (AT. The pregnant women with ovarian cysts who suffered from pelvic pain were divided into two groups; the first group consisted of the cases with surgically proven as AT (n = 17 and the second group consisted of the cases whose pain were resolved in the course of follow-up period without required surgery (n = 34. The clinical characteristics and serum D-dimer levels were compared between the groups. Patients with AT had a higher rate of elevated serum white blood cell (WBC count (57% vs. 16%, p = 0.04 and serum D-dimer levels (77% vs. 21%, p < 0.01 on admission in the study group than in the control group. Elevated D-dimer and cyst diameter larger than 5 cm yielded highest sensitivity (82% for each; whereas the presence of nausea and vomiting and elevated CRP had the highest specificity (85% and 88%, respectively. This is the first study that evaluates the serum D-dimer levels in humans in the diagnosis of AT, and our findings supported the use of D-dimer for the early diagnosis of AT in pregnant women.

  13. Automatic optimal filament segmentation with sub-pixel accuracy using generalized linear models and B-spline level-sets.

    Xiao, Xun; Geyer, Veikko F; Bowne-Anderson, Hugo; Howard, Jonathon; Sbalzarini, Ivo F

    2016-08-01

    Biological filaments, such as actin filaments, microtubules, and cilia, are often imaged using different light-microscopy techniques. Reconstructing the filament curve from the acquired images constitutes the filament segmentation problem. Since filaments have lower dimensionality than the image itself, there is an inherent trade-off between tracing the filament with sub-pixel accuracy and avoiding noise artifacts. Here, we present a globally optimal filament segmentation method based on B-spline vector level-sets and a generalized linear model for the pixel intensity statistics. We show that the resulting optimization problem is convex and can hence be solved with global optimality. We introduce a simple and efficient algorithm to compute such optimal filament segmentations, and provide an open-source implementation as an ImageJ/Fiji plugin. We further derive an information-theoretic lower bound on the filament segmentation error, quantifying how well an algorithm could possibly do given the information in the image. We show that our algorithm asymptotically reaches this bound in the spline coefficients. We validate our method in comprehensive benchmarks, compare with other methods, and show applications from fluorescence, phase-contrast, and dark-field microscopy. PMID:27104582

  14. Context, accuracy, and level of inclusion of nature of science concepts in current high school physics textbooks

    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

  15. The energy-spectrum of light primaries in the range from 10^{16.6} to 10^{18.2} eV

    Schoo, S; Arteaga-Velazquez, J C; Bekk, K; Bertaina, M; Bluemer, J; Bozdog, H; Brancus, I M; Cantoni, E; Chiavassa, A; Cossavella, F; Curcio, C; Daumiller, K; de Souza, V; Di Pierro, F; Doll, P; Engel, R; Engler, J; Fuchs, B; Fuhrmann, D; Gils, H J; Glasstetter, R; Grupen, C; Haungs, A; Heck, D; Hoerandel, J R; Huber, D; Huege, T; Kampert, K -H; Kang, D; Klages, H O; Link, K; Luczak, P; Ludwig, M; Mathes, H J; Mayer, H J; Melissas, M; Milke, J; Mitrica, B; Morello, C; Oehlschlaeger, J; Ostapchenko, S; Palmieri, N; Petcu, M; Pierog, T; Rebel, H; Roth, M; Schieler, H; Schroeder, F G; Sima, O; Toma, G; Trinchero, G C; Ulrich, H; Weindl, A; Wochele, D; Wochele, J

    2013-01-01

    Data of the Grande extension of the KASCADE experiment allows us to study extensive air showers induced by primary cosmic rays with energies above 10^{16} eV. The energy of an event is estimated in terms of the number of charged particles (Nch ) and the number of muons (N{\\mu} ) measured at an altitude of 110 m a.s.l. While a combination of the two numbers is used for the energy, the ratio defines the primary mass (group). The spectrum of the combined light and medium mass components, recently measured with KASCADE-Grande, was found to be compatible with both a single power-law and a broken power-law in the energy range between 10^{16.3} and 10^{18} eV. In this contribution we will present the investigation of possible structures in the spectrum of light primaries with increased statistics both from a larger data set including more recent measurements and by using a larger fiducial area than in the previous study. With the better statistical accuracy and with optimized selection criteria for enhancing light p...

  16. Use of Low-Level Sensor Data to Improve the Accuracy of Bluetooth-Based Travel Time Estimation

    Araghi, Bahar Namaki; Christensen, Lars Tørholm; Krishnan, Rajesh;

    2013-01-01

    Bluetooth sensors have a large detection zone compared with other static vehicle reidentification systems. A larger detection zone increases the probability of detecting a Bluetooth-enabled device in a fast-moving vehicle, yet increases the probability of multiple detection events being triggered...... by a single device. The latter situation could lead to location ambiguity and could reduce the accuracy of travel time estimation. Therefore, the accuracy of travel time estimation by Bluetooth technology depends on how location ambiguity is handled by the estimation method. The issue of multiple detection...... events in the context of travel time estimation by Bluetooth technology has been considered by various researchers. However, treatment of this issue has been simplistic. Most previous studies have used the first detection event (enter-enter) as the best estimate. No systematic analysis has been conducted...

  17. Particle distributions in approximately 10(14) 10(16) eV air shower cores at sea level

    Hodson, A. L.; Ash, A. G.; Bull, R. M.

    1985-01-01

    Experimental evidence is reported for fixed distances (0, 1.0, 2.5 and 4.0 m) from the shower centers and for core flattening. The cores become flatter, on average, as the shower size (primary energy) increases. With improved statistics on 4192 cores, the previous results are exactly confirmed.

  18. Impact of dose rate on accuracy of intensity modulated radiation therapy plan delivery using the pretreatment portal dosimetry quality assurance and setting up the workflow at hospital levels

    Karunakaran Kaviarasu; N Arunai Nambi Raj; Krishna Murthy, K.; A Ananda Giri Babu; Bhaskar Laxman Durga Prasad

    2015-01-01

    The aim of this study was to examine the impact of dose rate on accuracy of intensity modulated radiation therapy (IMRT) plan delivery by comparing the gamma agreement between the calculated and measured portal doses by pretreatment quality assurance (QA) using electronic portal imaging device dosimetry and creating a workflow for the pretreatment IMRT QA at hospital levels. As the improvement in gamma agreement leads to increase in the quality of IMRT treatment delivery, gamma evaluation was...

  19. Computational detection of allergenic proteins attains a new level of accuracy with in silico variable-length peptide extraction and machine learning

    Soeria-Atmadja, D.; Lundell, T.; Gustafsson, M. G.; Hammerling, U.

    2006-01-01

    The placing of novel or new-in-the-context proteins on the market, appearing in genetically modified foods, certain bio-pharmaceuticals and some household products leads to human exposure to proteins that may elicit allergic responses. Accurate methods to detect allergens are therefore necessary to ensure consumer/patient safety. We demonstrate that it is possible to reach a new level of accuracy in computational detection of allergenic proteins by presenting a novel detector, Detection based...

  20. The Development of Expertise in Radiology: In Chest Radiograph Interpretation, "Expert" Search Pattern May Predate "Expert" Levels of Diagnostic Accuracy for Pneumothorax Identification.

    Kelly, Brendan S; Rainford, Louise A; Darcy, Sarah P; Kavanagh, Eoin C; Toomey, Rachel J

    2016-07-01

    Purpose To investigate the development of chest radiograph interpretation skill through medical training by measuring both diagnostic accuracy and eye movements during visual search. Materials and Methods An institutional exemption from full ethical review was granted for the study. Five consultant radiologists were deemed the reference expert group, and four radiology registrars, five senior house officers (SHOs), and six interns formed four clinician groups. Participants were shown 30 chest radiographs, 14 of which had a pneumothorax, and were asked to give their level of confidence as to whether a pneumothorax was present. Receiver operating characteristic (ROC) curve analysis was carried out on diagnostic decisions. Eye movements were recorded with a Tobii TX300 (Tobii Technology, Stockholm, Sweden) eye tracker. Four eye-tracking metrics were analyzed. Variables were compared to identify any differences between groups. All data were compared by using the Friedman nonparametric method. Results The average area under the ROC curve for the groups increased with experience (0.947 for consultants, 0.792 for registrars, 0.693 for SHOs, and 0.659 for interns; P = .009). A significant difference in diagnostic accuracy was found between consultants and registrars (P = .046). All four eye-tracking metrics decreased with experience, and there were significant differences between registrars and SHOs. Total reading time decreased with experience; it was significantly lower for registrars compared with SHOs (P = .046) and for SHOs compared with interns (P = .025). Conclusion Chest radiograph interpretation skill increased with experience, both in terms of diagnostic accuracy and visual search. The observed level of experience at which there was a significant difference was higher for diagnostic accuracy than for eye-tracking metrics. (©) RSNA, 2016 Online supplemental material is available for this article. PMID:27322975

  1. Principal Components of Superhigh-Dimensional Statistical Features and Support Vector Machine for Improving Identification Accuracies of Different Gear Crack Levels under Different Working Conditions

    Dong Wang

    2015-01-01

    Full Text Available Gears are widely used in gearbox to transmit power from one shaft to another. Gear crack is one of the most frequent gear fault modes found in industry. Identification of different gear crack levels is beneficial in preventing any unexpected machine breakdown and reducing economic loss because gear crack leads to gear tooth breakage. In this paper, an intelligent fault diagnosis method for identification of different gear crack levels under different working conditions is proposed. First, superhigh-dimensional statistical features are extracted from continuous wavelet transform at different scales. The number of the statistical features extracted by using the proposed method is 920 so that the extracted statistical features are superhigh dimensional. To reduce the dimensionality of the extracted statistical features and generate new significant low-dimensional statistical features, a simple and effective method called principal component analysis is used. To further improve identification accuracies of different gear crack levels under different working conditions, support vector machine is employed. Three experiments are investigated to show the superiority of the proposed method. Comparisons with other existing gear crack level identification methods are conducted. The results show that the proposed method has the highest identification accuracies among all existing methods.

  2. The conservation value of elevation data accuracy and model sophistication in reserve design under sea‐level rise

    Zhu, Mingjian; Hoctor, Tom; Volk, Mike; Frank, Kathryn; Linhoss, Anna

    2015-01-01

    Abstract Many studies have explored the value of using more sophisticated coastal impact models and higher resolution elevation data in sea‐level rise (SLR) adaptation planning. However, we know little about to what extent the improved models and data could actually lead to better conservation outcomes under SLR. This is important to know because high‐resolution data are likely to not be available in some data‐poor coastal areas in the world and running more complicated coastal impact models ...

  3. Accuracy enhancement for forecasting water levels of reservoirs and river streams using a multiple-input-pattern fuzzification approach.

    Valizadeh, Nariman; El-Shafie, Ahmed; Mirzaei, Majid; Galavi, Hadi; Mukhlisin, Muhammad; Jaafar, Othman

    2014-01-01

    Water level forecasting is an essential topic in water management affecting reservoir operations and decision making. Recently, modern methods utilizing artificial intelligence, fuzzy logic, and combinations of these techniques have been used in hydrological applications because of their considerable ability to map an input-output pattern without requiring prior knowledge of the criteria influencing the forecasting procedure. The artificial neurofuzzy interface system (ANFIS) is one of the most accurate models used in water resource management. Because the membership functions (MFs) possess the characteristics of smoothness and mathematical components, each set of input data is able to yield the best result using a certain type of MF in the ANFIS models. The objective of this study is to define the different ANFIS model by applying different types of MFs for each type of input to forecast the water level in two case studies, the Klang Gates Dam and Rantau Panjang station on the Johor river in Malaysia, to compare the traditional ANFIS model with the new introduced one in two different situations, reservoir and stream, showing the new approach outweigh rather than the traditional one in both case studies. This objective is accomplished by evaluating the model fitness and performance in daily forecasting. PMID:24790567

  4. The conservation value of elevation data accuracy and model sophistication in reserve design under sea-level rise.

    Zhu, Mingjian; Hoctor, Tom; Volk, Mike; Frank, Kathryn; Linhoss, Anna

    2015-10-01

    Many studies have explored the value of using more sophisticated coastal impact models and higher resolution elevation data in sea-level rise (SLR) adaptation planning. However, we know little about to what extent the improved models and data could actually lead to better conservation outcomes under SLR. This is important to know because high-resolution data are likely to not be available in some data-poor coastal areas in the world and running more complicated coastal impact models is relatively time-consuming, expensive, and requires assistance by qualified experts and technicians. We address this research question in the context of identifying conservation priorities in response to SLR. Specifically, we investigated the conservation value of using more accurate light detection and ranging (Lidar)-based digital elevation data and process-based coastal land-cover change models (Sea Level Affecting Marshes Model, SLAMM) to identify conservation priorities versus simple "bathtub" models based on the relatively coarse National Elevation Dataset (NED) in a coastal region of northeast Florida. We compared conservation outcomes identified by reserve design software (Zonation) using three different model dataset combinations (Bathtub-NED, Bathtub-Lidar, and SLAMM-Lidar). The comparisons show that the conservation priorities are significantly different with different combinations of coastal impact models and elevation dataset inputs. The research suggests that it is valuable to invest in more accurate coastal impact models and elevation datasets in SLR adaptive conservation planning because this model-dataset combination could improve conservation outcomes under SLR. Less accurate coastal impact models, including ones created using coarser Digital Elevation Model (DEM) data can still be useful when better data and models are not available or feasible, but results need to be appropriately assessed and communicated. A future research priority is to investigate how

  5. Exploring the Impact of Visual Complexity Levels in 3d City Models on the Accuracy of Individuals' Orientation and Cognitive Maps

    Rautenbach, V.; Çöltekin, A.; Coetzee, S.

    2015-08-01

    In this paper we report results from a qualitative user experiment (n=107) designed to contribute to understanding the impact of various levels of complexity (mainly based on levels of detail, i.e., LoD) in 3D city models, specifically on the participants' orientation and cognitive (mental) maps. The experiment consisted of a number of tasks motivated by spatial cognition theory where participants (among other things) were given orientation tasks, and in one case also produced sketches of a path they `travelled' in a virtual environment. The experiments were conducted in groups, where individuals provided responses on an answer sheet. The preliminary results based on descriptive statistics and qualitative sketch analyses suggest that very little information (i.e., a low LoD model of a smaller area) might have a negative impact on the accuracy of cognitive maps constructed based on a virtual experience. Building an accurate cognitive map is an inherently desired effect of the visualizations in planning tasks, thus the findings are important for understanding how to develop better-suited 3D visualizations such as 3D city models. In this study, we specifically discuss the suitability of different levels of visual complexity for development planning (urban planning), one of the domains where 3D city models are most relevant.

  6. Two Methods to Derive Ground-level Concentrations of PM2.5 with Improved Accuracy in the North China, Calibrating MODIS AOD and CMAQ Model Predictions

    Lyu, Baolei; Hu, Yongtao; Chang, Howard; Russell, Armistead; Bai, Yuqi

    2016-04-01

    Reliable and accurate characterizations of ground-level PM2.5 concentrations are essential to understand pollution sources and evaluate human exposures etc. Monitoring network could only provide direct point-level observations at limited locations. At the locations without monitors, there are generally two ways to estimate the pollution levels of PM2.5. One is observations of aerosol properties from the satellite-based remote sensing, such as Moderate Resolution Imaging Spectroradiometer (MODIS) aerosol optical depth (AOD). The other one is from deterministic atmospheric chemistry models, such as the Community Multi-Scale Air Quality Model (CMAQ). In this study, we used a statistical spatio-temporal downscaler to calibrate the two datasets to monitor observations to derive fine-scale ground-level concentrations of PM2.5 with improved accuracy. We treated both MODIS AOD and CMAQ model predictions as biased proxy estimations of PM2.5 pollution levels. The downscaler proposed a Bayesian framework to model the spatially and temporally varying coefficients of the two types of estimations in the linear regression setting, in order to correct biases. Especially for calibrating MODIS AOD, a city-specific linear model was established to fill the missing AOD values, and a novel interpolation-based variable, i.e. PM2.5 Spatial Interpolator, was introduced to account for the spatial dependence among grid cells. We selected the heavy polluted and populated North China as our study area, in a grid setting of 81×81 12-km cells. For the evaluation of calibration performance for retrieved MODIS AOD, the R2 was 0.61 by the full model with PM2.5 Spatial Interpolator being presented, and was 0.48 with PM2.5 Spatial Interpolator not being presented. The constructed AOD values effectively predicted PM2.5 concentrations under our model structure, with R2=0.78. For the evaluation of calibrated CMAQ predictions, the R2 was 0.51, a little less than that of calibrated AOD. Finally we

  7. Comparison of predictive accuracy of pre surgical serum parathormone (PTH) level with that of parathyroid scan in case of primary hyperparathyroidism

    Full text: Aims and Objective: Parathyroid scintigraphy with Tc-99m Sestamibi is a sensitive and specific test for pre operative localization of parathyroid adenoma (PA) in patients with primary hyperparathyroidism. However false ve studies are not uncommon. Our aim was to find out the predictive accuracy of pre surgical parathormone (PTH) level with that of parathyroid scan in case of primary hyperparathyroidism. Materials And Method: A total of 54 patients (29 male, 25 female) with a mean age of 41. 24+14.26 years suspected of primary hyperparathyroidism were included in this study. All patients had serum PTH and calcium level higher than the normal limit. Parathyroid scintigraphy was done by subtraction method using 185 MBq of Tc-99m PO4 which was given first and images were taken by planar gamma camera after 20 minutes followed by Tc-99m Sestamibi (740MBq) injection without moving the patient. We calculated the sensitivity and specificity at different cut off values of PTH such as >70pg/ml, >80pg/ml, >90pg/ml and >100pg/ml and observed the changes in sensitivity, specificity, PPV and NPV against scintigraphic diagnosis of PA. Result: Parathyroid scintigraphy revealed 15 positive cases (27.8%) amongst 54 patients, which were surgically proven to be so. The sensitivity of PTH in predicting positive parathyroid scan revealed to be 86.7% at serum PTH level of 70-90pg/ml. Then the sensitivity declines steadily to 73.3% at PTH level of >100pg/ml. The specificity increases gradually from 20.5% at serum PTH level >70pg/ml to 53.8% at serum PTH level >100pg/ml. However, PPV and NPV of serum PTH did not experience significant change like sensitivity and specificity with the increase of cut off values. Conclusion: We can use a cut off value of pre surgical serum PTH level at 90pg/ml before doing parathyroid scan as this has maximum sensitivity and optimum specificity. It will help to predict the outcome of scan and avoid unnecessary parathyroid scan and false ve cases

  8. A broadband chip-scale optical frequency synthesizer at 2.7 × 10(-16) relative uncertainty.

    Huang, Shu-Wei; Yang, Jinghui; Yu, Mingbin; McGuyer, Bart H; Kwong, Dim-Lee; Zelevinsky, Tanya; Wong, Chee Wei

    2016-04-01

    Optical frequency combs-coherent light sources that connect optical frequencies with microwave oscillations-have become the enabling tool for precision spectroscopy, optical clockwork, and attosecond physics over the past decades. Current benchmark systems are self-referenced femtosecond mode-locked lasers, but Kerr nonlinear dynamics in high-Q solid-state microresonators has recently demonstrated promising features as alternative platforms. The advance not only fosters studies of chip-scale frequency metrology but also extends the realm of optical frequency combs. We report the full stabilization of chip-scale optical frequency combs. The microcomb's two degrees of freedom, one of the comb lines and the native 18-GHz comb spacing, are simultaneously phase-locked to known optical and microwave references. Active comb spacing stabilization improves long-term stability by six orders of magnitude, reaching a record instrument-limited residual instability of [Formula: see text]. Comparing 46 nitride frequency comb lines with a fiber laser frequency comb, we demonstrate the unprecedented microcomb tooth-to-tooth relative frequency uncertainty down to 50 mHz and 2.7 × 10(-16), heralding novel solid-state applications in precision spectroscopy, coherent communications, and astronomical spectrography. PMID:27152341

  9. Comparing Accuracy of Airborne Laser Scanning and TerraSAR-X Radar Images in the Estimation of Plot-Level Forest Variables

    Juha Hyyppä

    2010-01-01

    Full Text Available In this study we compared the accuracy of low-pulse airborne laser scanning (ALS data, multi-temporal high-resolution noninterferometric TerraSAR-X radar data and a combined feature set derived from these data in the estimation of forest variables at plot level. The TerraSAR-X data set consisted of seven dual-polarized (HH/HV or VH/VV Stripmap mode images from all seasons of the year. We were especially interested in distinguishing between the tree species. The dependent variables estimated included mean volume, basal area, mean height, mean diameter and tree species-specific mean volumes. Selection of best possible feature set was based on a genetic algorithm (GA. The nonparametric k-nearest neighbour (k-NN algorithm was applied to the estimation. The research material consisted of 124 circular plots measured at tree level and located in the vicinity of Espoo, Finland. There are large variations in the elevation and forest structure in the study area, making it demanding for image interpretation. The best feature set contained 12 features, nine of them originating from the ALS data and three from the TerraSAR-X data. The relative RMSEs for the best performing feature set were 34.7% (mean volume, 28.1% (basal area, 14.3% (mean height, 21.4% (mean diameter, 99.9% (mean volume of Scots pine, 61.6% (mean volume of Norway spruce and 91.6% (mean volume of deciduous tree species. The combined feature set outperformed an ALS-based feature set marginally; in fact, the latter was better in the case of species-specific volumes. Features from TerraSAR-X alone performed poorly. However, due to favorable temporal resolution, satellite-borne radar imaging is a promising data source for updating large-area forest inventories based on low-pulse ALS.

  10. Neighborhood disorder and screen time among 10-16 year old Canadian youth: A cross-sectional study

    Carson Valerie

    2012-05-01

    Full Text Available Abstract Background Screen time activities (e.g., television, computers, video games have been linked to several negative health outcomes among young people. In order to develop evidence-based interventions to reduce screen time, the factors that influence the behavior need to be better understood. High neighborhood disorder, which may encourage young people to stay indoors where screen time activities are readily available, is one potential factor to consider. Methods Results are based on 15,917 youth in grades 6-10 (aged 10-16 years old who participated in the Canadian 2009/10 Health Behaviour in School-aged Children Survey (HBSC. Total hours per week of television, video games, and computer use were reported by the participating students in the HBSC student questionnaire. Ten items of neighborhood disorder including safety, neighbors taking advantage, drugs/drinking in public, ethnic tensions, gangs, crime, conditions of buildings/grounds, abandoned buildings, litter, and graffiti were measured using the HBSC student questionnaire, the HBSC administrator questionnaire, and Geographic Information Systems. Based upon these 10 items, social and physical neighborhood disorder variables were derived using principal component analysis. Multivariate multilevel logistic regression analyses were used to examine the relationship between social and physical neighborhood disorder and individual screen time variables. Results High (top quartile social neighborhood disorder was associated with approximately 35-45% increased risk of high (top quartile television, computer, and video game use. Physical neighborhood disorder was not associated with screen time activities after adjusting for social neighborhood disorder. However, high social and physical neighborhood disorder combined was associated with approximately 40-60% increased likelihood of high television, computer, and video game use. Conclusion High neighborhood disorder is one environmental

  11. Evaluating IMRT and VMAT dose accuracy: Practical examples of failure to detect systematic errors when applying a commonly used metric and action levels

    Nelms, Benjamin E. [Canis Lupus LLC, Merrimac, Wisconsin 53561 (United States); Chan, Maria F. [Memorial Sloan-Kettering Cancer Center, Basking Ridge, New Jersey 07920 (United States); Jarry, Geneviève; Lemire, Matthieu [Hôpital Maisonneuve-Rosemont, Montréal, QC H1T 2M4 (Canada); Lowden, John [Indiana University Health - Goshen Hospital, Goshen, Indiana 46526 (United States); Hampton, Carnell [Levine Cancer Institute/Carolinas Medical Center, Concord, North Carolina 28025 (United States); Feygelman, Vladimir [Moffitt Cancer Center, Tampa, Florida 33612 (United States)

    2013-11-15

    Purpose: This study (1) examines a variety of real-world cases where systematic errors were not detected by widely accepted methods for IMRT/VMAT dosimetric accuracy evaluation, and (2) drills-down to identify failure modes and their corresponding means for detection, diagnosis, and mitigation. The primary goal of detailing these case studies is to explore different, more sensitive methods and metrics that could be used more effectively for evaluating accuracy of dose algorithms, delivery systems, and QA devices.Methods: The authors present seven real-world case studies representing a variety of combinations of the treatment planning system (TPS), linac, delivery modality, and systematic error type. These case studies are typical to what might be used as part of an IMRT or VMAT commissioning test suite, varying in complexity. Each case study is analyzed according to TG-119 instructions for gamma passing rates and action levels for per-beam and/or composite plan dosimetric QA. Then, each case study is analyzed in-depth with advanced diagnostic methods (dose profile examination, EPID-based measurements, dose difference pattern analysis, 3D measurement-guided dose reconstruction, and dose grid inspection) and more sensitive metrics (2% local normalization/2 mm DTA and estimated DVH comparisons).Results: For these case studies, the conventional 3%/3 mm gamma passing rates exceeded 99% for IMRT per-beam analyses and ranged from 93.9% to 100% for composite plan dose analysis, well above the TG-119 action levels of 90% and 88%, respectively. However, all cases had systematic errors that were detected only by using advanced diagnostic techniques and more sensitive metrics. The systematic errors caused variable but noteworthy impact, including estimated target dose coverage loss of up to 5.5% and local dose deviations up to 31.5%. Types of errors included TPS model settings, algorithm limitations, and modeling and alignment of QA phantoms in the TPS. Most of the errors were

  12. Evaluating IMRT and VMAT dose accuracy: Practical examples of failure to detect systematic errors when applying a commonly used metric and action levels

    Purpose: This study (1) examines a variety of real-world cases where systematic errors were not detected by widely accepted methods for IMRT/VMAT dosimetric accuracy evaluation, and (2) drills-down to identify failure modes and their corresponding means for detection, diagnosis, and mitigation. The primary goal of detailing these case studies is to explore different, more sensitive methods and metrics that could be used more effectively for evaluating accuracy of dose algorithms, delivery systems, and QA devices.Methods: The authors present seven real-world case studies representing a variety of combinations of the treatment planning system (TPS), linac, delivery modality, and systematic error type. These case studies are typical to what might be used as part of an IMRT or VMAT commissioning test suite, varying in complexity. Each case study is analyzed according to TG-119 instructions for gamma passing rates and action levels for per-beam and/or composite plan dosimetric QA. Then, each case study is analyzed in-depth with advanced diagnostic methods (dose profile examination, EPID-based measurements, dose difference pattern analysis, 3D measurement-guided dose reconstruction, and dose grid inspection) and more sensitive metrics (2% local normalization/2 mm DTA and estimated DVH comparisons).Results: For these case studies, the conventional 3%/3 mm gamma passing rates exceeded 99% for IMRT per-beam analyses and ranged from 93.9% to 100% for composite plan dose analysis, well above the TG-119 action levels of 90% and 88%, respectively. However, all cases had systematic errors that were detected only by using advanced diagnostic techniques and more sensitive metrics. The systematic errors caused variable but noteworthy impact, including estimated target dose coverage loss of up to 5.5% and local dose deviations up to 31.5%. Types of errors included TPS model settings, algorithm limitations, and modeling and alignment of QA phantoms in the TPS. Most of the errors were

  13. Effects of pH, lactate, hematocrit and potassium level on the accuracy of continuous glucose monitoring (CGM) in pediatric intensive care unit

    Marics, Gábor; Koncz, Levente; Eitler, Katalin; Vatai, Barbara; Szénási, Boglárka; Zakariás, David; Mikos, Borbála; Körner, Anna; Tóth-Heyn, Péter

    2015-01-01

    Background Continuous glucose monitoring (CGM) originally was developed for diabetic patients and it may be a useful tool for monitoring glucose changes in pediatric intensive care unit (PICU). Its use is, however, limited by the lack of sufficient data on its reliability at insufficient peripheral perfusion. We aimed to correlate the accuracy of CGM with laboratory markers relevant to disturbed tissue perfusion. Patients and Methods In 38 pediatric patients (age range, 0–18 years) requiring ...

  14. Experiences on improving diagnostic accuracy of FDG PET by characterizing, reducing, and avoiding the high-level physiological uptakes at abdomen and pelvic region

    ovaries, and were correlated well with the menstrual cycles. The 3 pseudo-negatives wer e gastric cancer, and although their SUVs decreased in the delayed imaging by gastric distension with foods, the lesions were actually more prominent with higher contrast. Discussions: Gastric cancer is one of the most common malignancies, especially in Asian population. However, FDG PET routinely performed under fasting status demonstrates limited value to its diagnosis because of the high-level physiological uptake of stomach. Gastric distension just before FDG PET scanning can benefit the early detection and accurate evaluation of primary tumor of gastric cancer. Physiological uptake of uterus and ovaries can mimic pelvic malignancies on FDG PET. For female patients with regular menstrual cycle, PET studies at late menstrual flow phase and early proliferative phase showed the least probability of intense or moderate physiological uptake. Delayed imaging, especially after changing physiological status by drinking, food ingestion, urination, and bowel movement, can help to exclude the physiological uptakes of gastrointestinal and urinary system. Conclusions: The diagnostic accuracy of FDG PET at abdomen and pelvic region can be improved by good understanding of the physiological uptakes, intentionally changing the physiological status, and proper arrangement of PET scanning. (author)

  15. The Epidemiology of Primary Anterior Shoulder Dislocations in Patients Aged 10-16 Years and Age-Stratified Risk of Recurrence

    Leroux, Timothy; Ogilvie-Harris, Darrell; Veillette, Christian; Chahal, Jaskarndip; Dwyer, Tim; Henry, Patrick; Khoshbin, Amir; Mahomed, Nizar; Wasserstein, David

    2015-01-01

    Objectives: Most clinical studies pertaining to shoulder dislocation use age cutoffs of 16 years, and at present, only small case series of patients aged 10-16 years guide our management. Using a general population cohort aged 10 to 16 years, we sought to: 1) determine the overall and demographic-specific incidence density rate (IDR) of primary anterior shoulder dislocation requiring closed reduction (CR), and 2) determine the rate of and risk factors for repeat shoulder CR. Methods: Using ad...

  16. Beta-delayed proton emission: a new series of precursors and the measurement of 10-16 s nuclear lifetimes

    We have now obtained results on a new series of even-Z precursors with Tsub(z) = +1/2. Like all known heavy precursors, the nuclei so far identified - 65Ge, 69Se, 73Kr, 77Sr, 81Zr and provisionally 85Mo - exhibit broad proton continua. However, the availability of such a series of nuclei makes it possible to extract a systematic picture of the beta-decay strength function as well as level densities, widths and decay energies from the observed spectra. By the addition of a new experimental technique we have also been able to determine the absolute values of the widths through direct measurement of the average lifetime of states populated in the emitter. These data all provide stringent tests of model calculations and mass formulae in a region of nuclei with N approximately Z, far removed from the valley of stability. (author)

  17. Low-level measuring techniques for neutrons: High accuracy neutron source strength determination and fluence rate measurement at an underground laboratory

    Zimbal, Andreas; Reginatto, Marcel; Schuhmacher, Helmut; Wiegel, Burkhard [Physikalisch-Technische Bundesanstalt, Bundesallee 100, 38116 Braunschweig (Germany); Degering, Detlev [Verein für Kernverfahrenstechnik und Analytik Rossendorf e. V. (VKTA), D-01314 Dresden (Germany); Zuber, Kai [Technische Universität Dresden, D-01069 Dresden (Germany)

    2013-08-08

    We report on measuring techniques for neutrons that have been developed at the Physikalisch-Technische Bundesanstalt (PTB), the German National Metrology Institute. PTB has characterized radioactive sources used in the BOREXINO and XENON100 experiments. For the BOREXINO experiment, a {sup 228}Th gamma radiation source was required which would not emit more than 10 neutrons per second. The determination of the neutron emission rate of this specially designed {sup 228}Th source was challenging due to the low neutron emission rate and because the ratio of neutron to gamma radiation was expected to be extremely low, of the order of 10{sup −6}. For the XENON100 detector, PTB carried out a high accuracy measurement of the neutron emission rate of an AmBe source. PTB has also done measurements in underground laboratories. A two month measurement campaign with a set of {sup 3}He-filled proportional counters was carried out in PTB's former UDO underground laboratory at the Asse salt mine. The aim of the campaign was to determine the intrinsic background of detectors, which is needed for the analysis of data taken in lowintensity neutron fields. At a later time, PTB did a preliminary measurement of the neutron fluence rate at the underground laboratory Felsenkeller operated by VKTA. By taking into account data from UDO, Felsenkeller, and detector calibrations made at the PTB facility, it was possible to estimate the neutron fluence rate at the Felsenkeller underground laboratory.

  18. Target Price Accuracy

    Alexander G. Kerl

    2011-01-01

    This study analyzes the accuracy of forecasted target prices within analysts’ reports. We compute a measure for target price forecast accuracy that evaluates the ability of analysts to exactly forecast the ex-ante (unknown) 12-month stock price. Furthermore, we determine factors that explain this accuracy. Target price accuracy is negatively related to analyst-specific optimism and stock-specific risk (measured by volatility and price-to-book ratio). However, target price accuracy is positive...

  19. The study in the primary energy range 10^{16} - 10^{17} eV with the Muon Tracking Detector in the KASCADE-Grande experiment

    Łuczak, P; Arteaga-Velázquez, J C; Bekk, K; Bertaina, M; Blümer, J; Bozdog, H; Brancus, I M; Cantoni, E; Chiavassa, A; Cossavella, F; Curcio, C; Daumiller, K; de Souza, V; Di Pierro, F; Doll, P; Engel, R; Engler, J; Fuchs, B; Fuhrmann, D; Gils, H J; Glasstetter, R; Grupen, C; Haungs, A; Heck, D; Hörandel, J R; Huber, D; Huege, T; Kampert, K -H; Kang, D; Klages, H O; Link, K; Ludwig, M; Mathes, H J; Mayer, H J; Melissas, M; Milke, J; Mitrica, B; Morello, C; Oehlschläger, J; Ostapchenko, S; Palmieri, N; Petcu, M; Pierog, T; Rebel, H; Roth, M; Schieler, H; Schoo, S; Schröder, F G; Sima, O; Toma, G; Trinchero, G C; Ulrich, H; Weindl, A; Wochele, J; Zabierowski, J

    2013-01-01

    The KASCADE-Grande Muon Tracking Detector enables with high accuracy the measurement of directions of EAS muons with energy above 0.8 GeV and up to 700 m distance from the shower centre. Reconstructed muon tracks are used to investigate muon pseudorapidity (eta) distributions. These distributions are nearly identical to the pseudorapidity distributions of their parent mesons produced in hadronic interactions. Comparison of the eta distributions from measured and simulated showers can be used to test the quality of the high energy hadronic interaction models. In this context a comparison of the QGSJet-II-2 and QGSJet-II-4 model will be shown. The pseudorapidity distributions reflect the longitudinal development of EAS and, as such, are sensitive to the mass of the cosmic rays primary particles. With various parameters of the eta distribution, obtained from the MTD data, it is possible to calculate the mean logarithmic mass of CRs. The results of the analysis in the primary energy range 10^{16} eV - 10^{17} eV...

  20. Dual-Energy CT-based Display of Bone Marrow Edema in Osteoporotic Vertebral Compression Fractures: Impact on Diagnostic Accuracy of Radiologists with Varying Levels of Experience in Correlation to MR Imaging.

    Kaup, Moritz; Wichmann, Julian L; Scholtz, Jan-Erik; Beeres, Martin; Kromen, Wolfgang; Albrecht, Moritz H; Lehnert, Thomas; Boettcher, Marie; Vogl, Thomas J; Bauer, Ralf W

    2016-08-01

    Purpose To evaluate whether a dual-energy (DE) computed tomographic (CT) virtual noncalcium technique can improve the detection rate of acute thoracolumbar vertebral compression fractures in patients with osteoporosis compared with that at magnetic resonance (MR) imaging depending on the level of experience of the reading radiologist. Materials and Methods This retrospective study was approved by the institutional ethics committee. Informed consent was obtained from all patients. Forty-nine patients with osteoporosis who were suspected of having acute vertebral fracture underwent DE CT and MR imaging. Conventional linear-blended CT scans and corresponding virtual noncalcium reconstructions were obtained. Five radiologists with varying levels of experience evaluated gray-scale CT scans for the presence of fractures and their suspected age. Then, virtual noncalcium images were evaluated to detect bone marrow edema. Findings were compared with those from MR imaging (the standard of reference). Sensitivity and specificity analyses for diagnostic performance and matched pair analyses were performed on vertebral fracture and patient levels. Results Sixty-two fractures were classified as fresh and 52 as old at MR imaging. The diagnostic performance of all readers in the detection of fresh fractures improved with the addition of virtual noncalcium reconstructions compared with that with conventional CT alone. Although the diagnostic accuracy of the least experienced reader with virtual noncalcium CT (accuracy with CT alone, 61%; accuracy with virtual noncalcium technique, 83%) was within the range of that of the most experienced reader with CT alone, the latter improved his accuracy with the noncalcium technique (from 81% to 95%), coming close to that with MR imaging. The number of vertebrae rated as unclear decreased by 59%-90% or from 15-53 to 2-13 in absolute numbers across readers. The number of patients potentially referred to MR imaging decreased by 36%-87% (from 11

  1. Magnetic resonance imaging and magnetic resonance arthrography of the shoulder: dependence on the level of training of the performing radiologist for diagnostic accuracy

    Theodoropoulos, John S. [University of Toronto, Division of Orthopaedics, Mount Sinai Hospital and the University Health Network, Toronto, ON (Canada); Andreisek, Gustav [University of Toronto, Department of Medical Imaging, Mount Sinai Hospital and the University Health Network, Toronto, ON (Canada); University Hospital Zuerich, Institute for Diagnostic Radiology, Zuerich (Switzerland); Harvey, Edward J. [McGill University, Division of Orthopaedics, MUHC - Montreal General Hospital, Montreal, Quebec (Canada); Wolin, Preston [Center for Athletic Medicine, Chicago, IL (United States)

    2010-07-15

    Discrepancies were identified between magnetic resonance (MR) imaging and clinical findings in patients who had MR imaging examinations evaluated by community-based general radiologists. The purpose of this study was to evaluate the diagnostic performance of MR imaging examinations of the shoulder with regard to the training level of the performing radiologist. A review of patient charts identified 238 patients (male/female, 175/63; mean age, 40.4 years) in whom 250 arthroscopies were performed and who underwent MR imaging or direct MR arthrography in either a community-based or hospital-based institution prior to surgery. All MR imaging and surgical reports were reviewed and the diagnostic performance for the detection of labral, rotator cuff, biceps, and Hill-Sachs lesions was determined. Kappa and Student's t test analyses were performed in a subset of cases in which initial community-based MR images were re-evaluated by hospital-based musculoskeletal radiologists, to determine the interobserver agreement and any differences in image interpretation. The diagnostic performance of community-based general radiologists was lower than that of hospital-based sub-specialized musculoskeletal radiologists. A sub-analysis of re-evaluated cases showed that musculoskeletal radiologists performed better. {kappa} values were 0.208, 0.396, 0.376, and 0.788 for labral, rotator cuff, biceps, and Hill-Sachs lesions (t test statistics: p =<0.001, 0.004, 0.019, and 0.235). Our results indicate that the diagnostic performance of MR imaging and MR arthrography of the shoulder depends on the training level of the performing radiologist, with sub-specialized musculoskeletal radiologists having a better diagnostic performance than general radiologists. (orig.)

  2. Relative accuracy evaluation.

    Yan Zhang

    Full Text Available The quality of data plays an important role in business analysis and decision making, and data accuracy is an important aspect in data quality. Thus one necessary task for data quality management is to evaluate the accuracy of the data. And in order to solve the problem that the accuracy of the whole data set is low while a useful part may be high, it is also necessary to evaluate the accuracy of the query results, called relative accuracy. However, as far as we know, neither measure nor effective methods for the accuracy evaluation methods are proposed. Motivated by this, for relative accuracy evaluation, we propose a systematic method. We design a relative accuracy evaluation framework for relational databases based on a new metric to measure the accuracy using statistics. We apply the methods to evaluate the precision and recall of basic queries, which show the result's relative accuracy. We also propose the method to handle data update and to improve accuracy evaluation using functional dependencies. Extensive experimental results show the effectiveness and efficiency of our proposed framework and algorithms.

  3. Relative accuracy evaluation.

    Zhang, Yan; Wang, Hongzhi; Yang, Zhongsheng; Li, Jianzhong

    2014-01-01

    The quality of data plays an important role in business analysis and decision making, and data accuracy is an important aspect in data quality. Thus one necessary task for data quality management is to evaluate the accuracy of the data. And in order to solve the problem that the accuracy of the whole data set is low while a useful part may be high, it is also necessary to evaluate the accuracy of the query results, called relative accuracy. However, as far as we know, neither measure nor effective methods for the accuracy evaluation methods are proposed. Motivated by this, for relative accuracy evaluation, we propose a systematic method. We design a relative accuracy evaluation framework for relational databases based on a new metric to measure the accuracy using statistics. We apply the methods to evaluate the precision and recall of basic queries, which show the result's relative accuracy. We also propose the method to handle data update and to improve accuracy evaluation using functional dependencies. Extensive experimental results show the effectiveness and efficiency of our proposed framework and algorithms. PMID:25133752

  4. Yakutsk array radio emission registration results in the energy range of 3*10^16-5*10^18 eV

    Petrov, I; Petrov, Z; Kozlov, V; Pravdin, M

    2013-01-01

    This paper presents the set of measurements of ultra-high energy air shower radio emission at frequency 32 MHz in period of 2008-2012. The showers are selected by geomagnetic and azimuth angles and then by the energy in three intervals: 3*10^16 3*10^17 eV, 3*10^17 6*10^17 eV and 6*10^17 5*10^18 eV. In each energy interval average lateral distribution function using mathematically averaged data from antennas with di?fferent directions are plotted. In the paper, using experimental data the dependence of radio signal averaged amplitude from geomagnetic angle, the shower axis distance and the energy are determined. Depth of maximum of cosmic ray showers Xmax for the given energy range is evaluated. The evaluation is made according QGSJET model calculations and average lateral distribution function shape.

  5. The Truth about Accuracy

    Buekens, Filip; Truyen, Frederik

    2014-01-01

    When we evaluate the outcomes of investigative actions as justified or unjustified, good or bad, rational or irrational, we make, in a broad sense of the term, evaluative judgments about them. We look at operational accuracy as a desirable and evaluable quality of the outcomes and explore how the concepts of accuracy and precision, on the basis of insights borrowed from pragmatics and measurement theory, can be seen to do useful work in epistemology. Operational accuracy (but not metaphysical...

  6. Rethinking Empathic Accuracy

    Meadors, Joshua

    2014-01-01

    The present study is a methodological examination of the implicit empathic accuracy measure introduced by Zaki, Ochsner, and Bolger (2008). Empathic accuracy (EA) is defined as the ability to understand another person's thoughts and feelings (Ickes, 1993). Because this definition is similar to definitions of cognitive empathy (e.g., Shamay-Tsoory, 2011) and because affective empathy does not appear to be related to empathic accuracy (Zaki et al., 2008), the Basic Empathy Scale--which measures...

  7. Classification Accuracy Is Not Enough

    Sturm, Bob L.

    2013-01-01

    A recent review of the research literature evaluating music genre recognition (MGR) systems over the past two decades shows that most works (81\\%) measure the capacity of a system to recognize genre by its classification accuracy. We show here, by implementing and testing three categorically...... different state-of-the-art MGR systems, that classification accuracy does not necessarily reflect the capacity of a system to recognize genre in musical signals. We argue that a more comprehensive analysis of behavior at the level of the music is needed to address the problem of MGR, and that measuring...... classification accuracy obscures the aim of MGR: to select labels indistinguishable from those a person would choose....

  8. 100% Classification Accuracy Considered Harmful: The Normalized Information Transfer Factor Explains the Accuracy Paradox

    Valverde-Albacete, Francisco J.; Carmen Peláez-Moreno

    2014-01-01

    The most widely spread measure of performance, accuracy, suffers from a paradox: predictive models with a given level of accuracy may have greater predictive power than models with higher accuracy. Despite optimizing classification error rate, high accuracy models may fail to capture crucial information transfer in the classification task. We present evidence of this behavior by means of a combinatorial analysis where every possible contingency matrix of 2, 3 and 4 classes classifiers are dep...

  9. Chemical, physical, profile and laboratory analysis oceanographic data collected aboard the OCEAN VERITAS in the Gulf of Mexico from 2010-09-07 to 2010-10-16 in response to the Deepwater Horizon Oil Spill event (NODC Accession 0069109)

    National Oceanic and Atmospheric Administration, Department of Commerce — Chemical, physical, profile and laboratory analysis oceanographic data were collected aboard the OCEAN VERITAS in the Gulf of Mexico from 2010-09-07 to 2010-10-16...

  10. Crystal Stratigraphy of Two Basalts from Apollo 16: Unique Crystallization of Picritic Basalt 606063,10-16 and Very-Low-Titanium Basalt 65703,9-13

    Donohue, P. H.; Neal, C. R.; Stevens, R. E.; Zeigler, R. A.

    2014-01-01

    A geochemical survey of Apollo 16 regolith fragments found five basaltic samples from among hundreds of 2-4 mm regolith fragments of the Apollo 16 site. These included a high-Ti vitrophyric basalt (60603,10-16) and one very-low-titanium (VLT) crystalline basalt (65703,9-13). Apollo 16 was the only highlands sample return mission distant from the maria (approx. 200 km). Identification of basaltic samples at the site not from the ancient regolith breccia indicates input of material via lateral transport by post-basin impacts. The presence of basaltic rocklets and glass at the site is not unprecedented and is required to satisfy mass-balance constraints of regolith compositions. However, preliminary characterization of olivine and plagioclase crystal size distributions indicated the sample textures were distinct from other known mare basalts, and instead had affinities to impact melt textures. Impact melt textures can appear qualitatively similar to pristine basalts, and quantitative analysis is required to distinguish between the two in thin section. The crystal stratigraphy method is a powerful tool in studying of igneous systems, utilizing geochemical analyses across minerals and textural analyses of phases. In particular, trace element signatures can aid in determining the ultimate origin of these samples and variations document subtle changes occurring during their petrogenesis.

  11. Genetic structure of different cat populations in Europe and South America at a microgeographic level: importance of the choice of an adequate sampling level in the accuracy of population genetics interpretations

    Manuel Ruiz-Garcia

    1999-12-01

    Full Text Available The phenotypic markers, coat color, pattern and hair length, of natural domestic cat populations observed in four cities (Barcelona, Catalonia; Palma Majorca, Balearic Islands; Rimini, Italy and Buenos Aires, Argentina were studied at a microgeographical level. Various population genetics techniques revealed that the degree of genetic differentiation between populations of Felis catus within these cities is relatively low, when compared with that found between populations of other mammals. Two different levels of sampling were used. One was that of "natural" colonies of cat families living together in specific points within the cities, and the other referred to "artificial" subpopulations, or groups of colonies, inhabiting the same district within a city. For the two sampling levels, some of the results were identical: 1 little genic heterogeneity, 2 existence of panmixia, 3 similar levels of expected heterozygosity in all populations analyzed, 4 no spatial autocorrelation, with certain differentiation in the Buenos Aires population compared to the others, and 5 very high correlations between colonies and subpopulations with the first factors from a Q factor analysis. Nevertheless, other population genetic statistics were greatly affected by the differential choice of sampling level. This was the case for: 1 the amount of heterogeneity of the FST and GST statistics between the cities, which was greater at the subpopulation level than at colony level, 2 the existence of correlations between genic differentiation statistics and size variables at subpopulation level, but not at the colony level, and 3 the relationships between the genetic variables and the principal factors of the R factorial analysis. This suggests that care should be taken in the choice of the sampling unit, for inferences on population genetics to be valid at the microgeographical level.Os marcadores fenotípicos cor da pelagem, padrão e comprimento dos pelos de popula

  12. Diagnosing Eyewitness Accuracy

    Russ, Andrew

    2015-01-01

    Eyewitnesses frequently mistake innocent people for the perpetrator of an observed crime. Such misidentifications have led to the wrongful convictions of many people. Despite this, no reliable method yet exists to determine eyewitness accuracy. This thesis explored two new experimental methods for this purpose. Chapter 2 investigated whether repetition priming can measure prior exposure to a target and compared this with observers’ explicit eyewitness accuracy. Across three experiments slower...

  13. Social Security Administration Data for Enumeration Accuracy

    Social Security Administration — This dataset provides data at the national level from federal fiscal year 2006 onwards for the accuracy of the assignment of Social Security numbers (SSN) based on...

  14. Accuracy of Approximate Eigenstates

    Lucha, Wolfgang; Lucha, Wolfgang

    2000-01-01

    Besides perturbation theory, which requires, of course, the knowledge of the exact unperturbed solution, variational techniques represent the main tool for any investigation of the eigenvalue problem of some semibounded operator H in quantum theory. For a reasonable choice of the employed trial subspace of the domain of H, the lowest eigenvalues of H usually can be located with acceptable precision whereas the trial-subspace vectors corresponding to these eigenvalues approximate, in general, the exact eigenstates of H with much less accuracy. Accordingly, various measures for the accuracy of the approximate eigenstates derived by variational techniques are scrutinized. In particular, the matrix elements of the commutator of the operator H and (suitably chosen) different operators, with respect to degenerate approximate eigenstates of H obtained by some variational method, are proposed here as new criteria for the accuracy of variational eigenstates. These considerations are applied to that Hamiltonian the eig...

  15. Diagnostic test accuracy

    Campbell, Jared M.; Klugar, Miloslav; Ding, Sandrine; Carmody, Dennis P.; Håkonsen, Sasja Jul; Jadotte, Yuri T.; White, Sarahlouise; Munn, Zachary

    2015-01-01

    in providing methodological guidance for the conduct of systematic reviews and has developed methods and guidance for reviewers conducting systematic reviews of studies of diagnostic test accuracy. Diagnostic tests are used to identify the presence or absence of a condition for the purpose of...... developing an appropriate treatment plan. Owing to demands for improvements in speed, cost, ease of performance, patient safety, and accuracy, new diagnostic tests are continuously developed, and there are often several tests available for the diagnosis of a particular condition. In order to provide the...... evidence necessary for clinicians and other healthcare professionals to make informed decisions regarding the optimum test to use, primary studies need to be carried out on the accuracy of diagnostic tests and the results of these studies synthesized through systematic review. The Joanna Briggs Institute...

  16. To determine the accuracy of focused assessment with sonography for trauma done by nonradiologists and its comparative analysis with radiologists in emergency department of a level 1 trauma center of India

    Sanjeev Bhoi

    2013-01-01

    Full Text Available Background: Focused assessment with sonography for trauma (FAST is an important skill during trauma resuscitation. Use of point of care ultrasound among the trauma team working in emergency care settings is lacking in India. Objective: To determine the accuracy of FAST done by nonradiologists (NR when compared to radiologists during primary survey of trauma victims in the emergency department of a level 1 trauma center in India. Materials and Methods: A prospective study was done during primary survey of resuscitation of nonconsecutive patients in the resuscitation bay. The study subjects included NR such as one consultant emergency medicine, two medicine residents, one orthopedic resident and one surgery resident working as trauma team. These subjects underwent training at 3-day workshop on emergency sonography and performed 20 supervised positive and negative scans for free fluid. The FAST scans were first performed by NR and then by radiology residents (RR. The performers were blinded to each other′s sonography findings. Computed tomography (CT and laparotomy findings were used as gold standard whichever was feasible. Results were compared between both the groups. Intraobserver variability among NR and RR were noted. Results: Out of 150 scans 144 scans were analyzed. Mean age of the patients was 28 [1-70] years. Out of 24 true positive patients 18 underwent CT scan and exploratory laparotomies were done in six patients. Sensitivity of FAST done by NR and RR were 100% and 95.6% and specificity was 97.5% in both groups. Positive predictive value among NR and RR were 88.8%, 88.46% and negative predictive value were 97.5% and 99.15%. Intraobserver performance variation ranged from 87 to 97%. Conclusion: FAST performed by NRs is accurate during initial trauma resuscitation in the emergency department of a level 1 trauma center in India.

  17. Does the experience level of the radiologist, assessment in consensus, or the addition of the abduction and external rotation view improve the diagnostic reproducibility and accuracy of MRA of the shoulder?

    Aim: To prospectively evaluate the influence of observer experience, consensus assessment, and abduction and external rotation (ABER) view on the diagnostic performance of magnetic resonance arthrography (MRA) in patients with traumatic anterior-shoulder instability (TASI). Materials and methods: Fifty-eight MRA examinations (of which 51 had additional ABER views) were assessed by six radiologists (R1–R6) and three teams (T1–T3) with different experience levels, using a seven-lesion standardized scoring form. Forty-five out of 58 MRA examination findings were surgically confirmed. Kappa coefficients, sensitivity, specificity, and differences in percent agreement or correct diagnosis (p-value, McNemar's test) were calculated per lesion and overall per seven lesion types to assess diagnostic reproducibility and accuracy. Results: Overall kappa ranged from poor (k = 0.17) to moderate (k = 0.53), sensitivity from 30.6–63.5%, and specificity from 73.6–89.9%. Overall, the most experienced radiologists (R1–R2) and teams (T2–T3) agreed significantly more than the lesser experienced radiologists (R3–R4: p = 0.014, R5–R6; p = 0.018) and teams (T2–T3: p = 0.007). The most experienced radiologist (R1, R2, R3) and teams (T1, T2) were also consistently more accurate than the lesser experienced radiologists (R4, R5, R6) and team (T3). Significant differences were found between R1–R4 (p = 0.012), R3–R4 (p = 0.03), and T2–T3 (p = 0.014). The overall performance of consensus assessment was systematically higher than individual assessment. Significant differences were established between T1–T2 and radiologists R3–R4 (p<0.001, p = 0.001) and between T2 and R3 (p<0.001/p = 0.001) or R4 (p = 0.050). No overall significant differences were found between the radiologists' assessments with and without ABER. Conclusion: The addition of ABER does not significantly improve overall diagnostic performance. The radiologist

  18. The Accuracy of Multiples

    Stauropoulos Antonios

    2011-01-01

    Full Text Available Problem statement: Equity valuation with the use of multiples is widely used by academics and practitioners concerning its functionality. This study aims to explore the sensitivity of three multiples in terms of accuracy. Approach: Price-to-Sales (P/S multiple, the price-to-book value of equity (P/B multiple and the Price-to-Earnings (P/E multiple are three multiples under consideration, using both current and one-year-ahead earnings forecasts. Results: Evidence of empirical results show that, the multiples P/mdfy1 and P/mnfy1 are effective in terms of accuracy, with their means being negatively biased and their medians being positively biased. Finally, current earnings are identified as more appropriate value driver for the calculation of the P/E ratio by terms of accuracy. The results can be considered as reliable owing to the large sample and the procedure followed for its selection. Conclusion: This study offers a better understanding of the valuation approach through the use of multiples, in order analysts assumption to be more carefully and properly chosen and their results to be more accurately produced.

  19. Overlay accuracy fundamentals

    Kandel, Daniel; Levinski, Vladimir; Sapiens, Noam; Cohen, Guy; Amit, Eran; Klein, Dana; Vakshtein, Irina

    2012-03-01

    Currently, the performance of overlay metrology is evaluated mainly based on random error contributions such as precision and TIS variability. With the expected shrinkage of the overlay metrology budget to interaction with the metrology technology, as the main source of overlay inaccuracy. The most important type of mark imperfection is mark asymmetry. Overlay mark asymmetry leads to a geometrical ambiguity in the definition of overlay, which can be ~1nm or less. It is shown theoretically and in simulations that the metrology may enhance the effect of overlay mark asymmetry significantly and lead to metrology inaccuracy ~10nm, much larger than the geometrical ambiguity. The analysis is carried out for two different overlay metrology technologies: Imaging overlay and DBO (1st order diffraction based overlay). It is demonstrated that the sensitivity of DBO to overlay mark asymmetry is larger than the sensitivity of imaging overlay. Finally, we show that a recently developed measurement quality metric serves as a valuable tool for improving overlay metrology accuracy. Simulation results demonstrate that the accuracy of imaging overlay can be improved significantly by recipe setup optimized using the quality metric. We conclude that imaging overlay metrology, complemented by appropriate use of measurement quality metric, results in optimal overlay accuracy.

  20. Accuracy of tablet splitting.

    McDevitt, J T; Gurst, A H; Chen, Y

    1998-01-01

    We attempted to determine the accuracy of manually splitting hydrochlorothiazide tablets. Ninety-four healthy volunteers each split ten 25-mg hydrochlorothiazide tablets, which were then weighed using an analytical balance. Demographics, grip and pinch strength, digit circumference, and tablet-splitting experience were documented. Subjects were also surveyed regarding their willingness to pay a premium for commercially available, lower-dose tablets. Of 1752 manually split tablet portions, 41.3% deviated from ideal weight by more than 10% and 12.4% deviated by more than 20%. Gender, age, education, and tablet-splitting experience were not predictive of variability. Most subjects (96.8%) stated a preference for commercially produced, lower-dose tablets, and 77.2% were willing to pay more for them. For drugs with steep dose-response curves or narrow therapeutic windows, the differences we recorded could be clinically relevant. PMID:9469693

  1. When Can Subscores Be Expected to Have Added Value? Results from Operational and Simulated Data. Research Report. ETS RR-10-16

    Sinharay, Sandip

    2010-01-01

    Recently, there has been an increasing level of interest in subscores for their potential diagnostic value. Haberman (2008) suggested a method based on classical test theory to determine whether subscores have added value over total scores. This paper provides a literature review and reports when subscores were found to have added value for…

  2. Reticence, Accuracy and Efficacy

    Oreskes, N.; Lewandowsky, S.

    2015-12-01

    James Hansen has cautioned the scientific community against "reticence," by which he means a reluctance to speak in public about the threat of climate change. This may contribute to social inaction, with the result that society fails to respond appropriately to threats that are well understood scientifically. Against this, others have warned against the dangers of "crying wolf," suggesting that reticence protects scientific credibility. We argue that both these positions are missing an important point: that reticence is not only a matter of style but also of substance. In previous work, Bysse et al. (2013) showed that scientific projections of key indicators of climate change have been skewed towards the low end of actual events, suggesting a bias in scientific work. More recently, we have shown that scientific efforts to be responsive to contrarian challenges have led scientists to adopt the terminology of a "pause" or "hiatus" in climate warming, despite the lack of evidence to support such a conclusion (Lewandowsky et al., 2015a. 2015b). In the former case, scientific conservatism has led to under-estimation of climate related changes. In the latter case, the use of misleading terminology has perpetuated scientific misunderstanding and hindered effective communication. Scientific communication should embody two equally important goals: 1) accuracy in communicating scientific information and 2) efficacy in expressing what that information means. Scientists should strive to be neither conservative nor adventurous but to be accurate, and to communicate that accurate information effectively.

  3. Accuracy and repeatability of quantitative fluoroscopy for the measurement of sagittal plane translation and finite centre of rotation in the lumbar spine.

    Breen, Alexander; Breen, Alan

    2016-07-01

    Quantitative fluoroscopy (QF) was developed to measure intervertebral mechanics in vivo and has been found to have high repeatability and accuracy for the measurement of intervertebral rotations. However, sagittal plane translation and finite centre of rotation (FCR) are potential measures of stability but have not yet been fully validated for current QF. This study investigated the repeatability and accuracy of QF for measuring these variables. Repeatability was assessed from L2-S1 in 20 human volunteers. Accuracy was investigated using 10 consecutive measurements from each of two pairs of linked and instrumented dry human vertebrae as reference; one which tilted without translation and one which translated without tilt. The results found intra- and inter-observer repeatability for translation to be 1.1mm or less (SEM) with fair to substantial reliability (ICC 0.533-0.998). Intra-observer repeatability of FCR location for inter-vertebral rotations of 5° and above ranged from 1.5mm to 1.8mm (SEM) with moderate to substantial reliability (ICC 0.626-0.988). Inter-observer repeatability for FCR ranged from 1.2mm to 5.7mm, also with moderate to substantial reliability (ICC 0.621-0.878). Reliability was substantial (ICC>0.81) for 10/16 measures for translation and 5/8 for FCR location. Accuracy for translation was 0.1mm (fixed centre) and 2.2mm (moveable centre), with an FCR error of 0.3mm(x) and 0.4mm(y) (fixed centre). This technology was found to have a high level of accuracy and with a few exceptions, moderate to substantial repeatability for the measurement of translation and FCR from fluoroscopic motion sequences. PMID:27129784

  4. Particle distributions in approximately 10(13) - 10(16) eV air shower cores at mountain altitude and comparison with Monte Carlo simulations

    Ash, A. G.

    1985-01-01

    Photographs of 521 shower cores in an array of current-limited spark (discharge) chambers at Sacramento Peak (2900m above sea level, 730 g /sq cm.), New Mexico, U.S.A., have been analyzed and the results compared with similar data from Leeds (80m above sea level, 1020 g sq cm.). It was found that the central density differential spectrum is consistent with a power law index of -2 up to approx. 1500/sq m where it steepens, and that shower cores become flatter on average with increasing size. Scaling model predictions for proton primaries with a approx E sup -2.71 energy spectrum account well for the altitude dependence of the data at lower densities. However, deviations at higher densities indicate a change in hadron interaction characteristics between approx few x 10 to the 14th power and 10 to the 15th power eV primary energy causing particles close to the shower axis to be spread further out.

  5. ACCURACY AND FLUENCY IN COMMUNICATIVE LANGUAGE TEACHING

    2000-01-01

    Ⅰ. Introduction In English language teaching, at whatever level, teachers feel it very important to focus on accuracy and fluency in a pedagogic way. It is now widely accepted that neither of them should be focused on alone all the way through the teaching process. From our teaching experience, we can see that to some extent this is true.

  6. Astrophysics with Microarcsecond Accuracy Astrometry

    Unwin, Stephen C.

    2008-01-01

    Space-based astrometry promises to provide a powerful new tool for astrophysics. At a precision level of a few microarcsonds, a wide range of phenomena are opened up for study. In this paper we discuss the capabilities of the SIM Lite mission, the first space-based long-baseline optical interferometer, which will deliver parallaxes to 4 microarcsec. A companion paper in this volume will cover the development and operation of this instrument. At the level that SIM Lite will reach, better than 1 microarcsec in a single measurement, planets as small as one Earth can be detected around many dozen of the nearest stars. Not only can planet masses be definitely measured, but also the full orbital parameters determined, allowing study of system stability in multiple planet systems. This capability to survey our nearby stellar neighbors for terrestrial planets will be a unique contribution to our understanding of the local universe. SIM Lite will be able to tackle a wide range of interesting problems in stellar and Galactic astrophysics. By tracing the motions of stars in dwarf spheroidal galaxies orbiting our Milky Way, SIM Lite will probe the shape of the galactic potential history of the formation of the galaxy, and the nature of dark matter. Because it is flexibly scheduled, the instrument can dwell on faint targets, maintaining its full accuracy on objects as faint as V=19. This paper is a brief survey of the diverse problems in modern astrophysics that SIM Lite will be able to address.

  7. Back-propagation of accuracy

    Senashova, M. Yu.; Gorban, A. N.; Wunsch II, D. C.

    2003-01-01

    In this paper we solve the problem: how to determine maximal allowable errors, possible for signals and parameters of each element of a network proceeding from the condition that the vector of output signals of the network should be calculated with given accuracy? "Back-propagation of accuracy" is developed to solve this problem. The calculation of allowable errors for each element of network by back-propagation of accuracy is surprisingly similar to a back-propagation of error, because it is...

  8. Current Concept of Geometrical Accuracy

    Görög Augustín; Görögová Ingrid

    2014-01-01

    Within the solving VEGA 1/0615/12 research project "Influence of 5-axis grinding parameters on the shank cutter´s geometric accuracy", the research team will measure and evaluate geometrical accuracy of the produced parts. They will use the contemporary measurement technology (for example the optical 3D scanners). During the past few years, significant changes have occurred in the field of geometrical accuracy. The objective of this contribution is to analyse the current standards in the fiel...

  9. Observer accuracy in reading chest films

    Four board-certified radiologists have read and reread four groups of 40 chest radiographs containing nodule and infiltrate images to investigate interreader and intrareader variation. Responses were recorded using a six-point confidence level scale. Accuracy was determined from the area under the receiver operating characteristic (ROC) curve. Accuracies ranged from 0.78 to 0.98, with an average of 0.83 and a mean uncertainty of 8.2%. Intraobserver uncertainties varied from 0.5% to 16%, with a mean of 5.9%. The data were analyzed for the significance of accuracy differences using correlated ROC techniques, the kappa statistic, and the Bonnferoni criteria. Implications for using reader performance as a recertification measure are discussed

  10. Kalendar nedeli : 10 - 16 maja / Natalja Lesnaja

    Lesnaja, Natalja

    1995-01-01

    Iz soderzh.: 10 maja 235 let so dnja rozhdenia Kloda Zhozefa Ruzhe de Lilja, (1760 - 1836); 13 maja 155 let so dnja rozhdenia Alfonsa Dode, (1840 - 1897); 15 maja 105 let so dnja rozhdenia Ketrin Enn Porter, (1890 - 1980); 16 maja 85 let so dnja rozhdenia Olgi Fjodorovnõ Berggolts, (1910 - 1975)

  11. 19 CFR 10.16 - Assembly abroad.

    2010-04-01

    ... electrolytic capacitor is assembled abroad from American-made aluminum foil, paper, tape, and Mylar film. In... fastened to the surface to prevent these components from unwinding. Wire or other electric connectors are... can, and the ends closed with a protective washer. As imported, the capacitor is subject to the...

  12. Diagnostic Accuracy of Procalcitonin in Bacterial Meningitis Versus Nonbacterial Meningitis

    Wei, Ting-Ting; Hu, Zhi-De; Qin, Bao-Dong; Ma, Ning; Tang, Qing-Qin; Wang, Li-li; ZHOU, Lin; Zhong, Ren-Qian

    2016-01-01

    Abstract Several studies have investigated the diagnostic accuracy of procalcitonin (PCT) levels in blood or cerebrospinal fluid (CSF) in bacterial meningitis (BM), but the results were heterogeneous. The aim of the present study was to ascertain the diagnostic accuracy of PCT as a marker for BM detection. A systematic search of the EMBASE, Scopus, Web of Science, and PubMed databases was performed to identify studies published before December 7, 2015 investigating the diagnostic accuracy of ...

  13. Achievable precision and accuracy of dose determinations from routine dosemeters

    The concepts of accuracy and precision as associated with dose determinations from routine dosemeters are analyzed. The factors which are most important when considering the accuracy of such measurements are then discussed. These include environmental conditions such as humidity, temperature, dose rate and time since irradiation. Some examples are presented. It is concluded that precision under identical irradiation conditions for reproducibility can be ± 2% at the 95% confidence level. The corresponding accuracy should not be more than ± 5%. (U.K.)

  14. Hypersecretion of the alpha-subunit in clinically non-functioning pituitary adenomas: Diagnostic accuracy is improved by adding alpha-subunit/gonadotropin ratio to levels of alpha-subunit

    Andersen, Marianne; Ganc-Petersen, Joanna; Jørgensen, Jens O L;

    2010-01-01

    In vitro, the majority of clinically non-functioning pituitary adenomas (NFPAs) produce gonadotropins or their alpha-subunit; however, in vivo, measurements of alpha-subunit levels may not accurately detect the hypersecretion of the alpha-subunit.......In vitro, the majority of clinically non-functioning pituitary adenomas (NFPAs) produce gonadotropins or their alpha-subunit; however, in vivo, measurements of alpha-subunit levels may not accurately detect the hypersecretion of the alpha-subunit....

  15. Hypersecretion of the alpha-subunit in clinically non-functioning pituitary adenomas: Diagnostic accuracy is improved by adding alpha-subunit/gonadotropin ratio to levels of alpha-subunit

    Andersen, Marianne; Ganc-Petersen, Joanna; Jørgensen, Jens Otto Lunde;

    2010-01-01

    when the alpha-ratios, rather than simply the alpha-subunit levels, were measured in patients with NFPAs. MATERIAL AND METHODS: Reference intervals for gonadotropin alpha-subunit serum levels and alpha-ratios were established in 231 healthy adults. The estimated cut-off limits were applied to 37...... patients with NFPAs. Gonadotropin alpha-subunit, LH and FSH levels were measured and alpha-ratios were calculated. RESULTS: In healthy adults, the cut-offs for alpha-subunit levels were significantly different between men and pre- and postmenopausal women: the cut-offs were 1.10, 0.48 and 3.76 IU....../l, respectively. Using these estimated cut-offs, increased alpha-subunit levels were identified in 10 out of 37 (27%) patients with NFPAs. By adding alpha-ratio, in combination with alpha-subunit levels, 23 patients out of 37 (62%) were identified as having elevated alpha-subunit hypersecretion, and 22 out of...

  16. Is increasing complexity of algorithms the price for higher accuracy? virtual comparison of three algorithms for tertiary level management of chronic cough in people living with HIV in a low-income country

    Mukabatsinda Constance

    2012-01-01

    Full Text Available Abstract Background The algorithmic approach to guidelines has been introduced and promoted on a large scale since the 1970s. This study aims at comparing the performance of three algorithms for the management of chronic cough in patients with HIV infection, and at reassessing the current position of algorithmic guidelines in clinical decision making through an analysis of accuracy, harm and complexity. Methods Data were collected at the University Hospital of Kigali (CHUK in a total of 201 HIV-positive hospitalised patients with chronic cough. We simulated management of each patient following the three algorithms. The first was locally tailored by clinicians from CHUK, the second and third were drawn from publications by Médecins sans Frontières (MSF and the World Health Organisation (WHO. Semantic analysis techniques known as Clinical Algorithm Nosology were used to compare them in terms of complexity and similarity. For each of them, we assessed the sensitivity, delay to diagnosis and hypothetical harm of false positives and false negatives. Results The principal diagnoses were tuberculosis (21% and pneumocystosis (19%. Sensitivity, representing the proportion of correct diagnoses made by each algorithm, was 95.7%, 88% and 70% for CHUK, MSF and WHO, respectively. Mean time to appropriate management was 1.86 days for CHUK and 3.46 for the MSF algorithm. The CHUK algorithm was the most complex, followed by MSF and WHO. Total harm was by far the highest for the WHO algorithm, followed by MSF and CHUK. Conclusions This study confirms our hypothesis that sensitivity and patient safety (i.e. less expected harm are proportional to the complexity of algorithms, though increased complexity may make them difficult to use in practice.

  17. Developing a Weighted Measure of Speech Sound Accuracy

    Preston, Jonathan L.; Ramsdell, Heather L.; Oller, D. Kimbrough; Edwards, Mary Louise; Tobin, Stephen J.

    2011-01-01

    Purpose: To develop a system for numerically quantifying a speaker's phonetic accuracy through transcription-based measures. With a focus on normal and disordered speech in children, the authors describe a system for differentially weighting speech sound errors on the basis of various levels of phonetic accuracy using a Weighted Speech Sound…

  18. Diagnostic accuracy in virtual dermatopathology

    Mooney, E.; Kempf, W.; Jemec, G.B.E.;

    2012-01-01

    slides and photomicrographs with corresponding clinical photographs and information in a self-assessment examination format. Descriptive data analysis and comparison of groups were performed using a chi-square test. Results Diagnostic accuracy in dermatopathology using virtual dermatopathology or...... diagnostic accuracy of dermatopathologists and pathologists using photomicrographs vs. digitized images, through a self-assessment examination, and to elucidate assessment of virtual dermatopathology. Methods Forty-five dermatopathologists and pathologists received a randomized combination of 15 virtual...

  19. Field Accuracy Test of Rpas Photogrammetry

    Barry, P.; Coakley, R.

    2013-08-01

    Baseline Surveys Ltd is a company which specialises in the supply of accurate geospatial data, such as cadastral, topographic and engineering survey data to commercial and government bodies. Baseline Surveys Ltd invested in aerial drone photogrammetric technology and had a requirement to establish the spatial accuracy of the geographic data derived from our unmanned aerial vehicle (UAV) photogrammetry before marketing our new aerial mapping service. Having supplied the construction industry with survey data for over 20 years, we felt that is was crucial for our clients to clearly understand the accuracy of our photogrammetry so they can safely make informed spatial decisions, within the known accuracy limitations of our data. This information would also inform us on how and where UAV photogrammetry can be utilised. What we wanted to find out was the actual accuracy that can be reliably achieved using a UAV to collect data under field conditions throughout a 2 Ha site. We flew a UAV over the test area in a "lawnmower track" pattern with an 80% front and 80% side overlap; we placed 45 ground markers as check points and surveyed them in using network Real Time Kinematic Global Positioning System (RTK GPS). We specifically designed the ground markers to meet our accuracy needs. We established 10 separate ground markers as control points and inputted these into our photo modelling software, Agisoft PhotoScan. The remaining GPS coordinated check point data were added later in ArcMap to the completed orthomosaic and digital elevation model so we could accurately compare the UAV photogrammetry XYZ data with the RTK GPS XYZ data at highly reliable common points. The accuracy we achieved throughout the 45 check points was 95% reliably within 41 mm horizontally and 68 mm vertically and with an 11.7 mm ground sample distance taken from a flight altitude above ground level of 90 m.The area covered by one image was 70.2 m × 46.4 m, which equals 0.325 Ha. This finding has shown

  20. 100% classification accuracy considered harmful: the normalized information transfer factor explains the accuracy paradox.

    Francisco J Valverde-Albacete

    Full Text Available The most widely spread measure of performance, accuracy, suffers from a paradox: predictive models with a given level of accuracy may have greater predictive power than models with higher accuracy. Despite optimizing classification error rate, high accuracy models may fail to capture crucial information transfer in the classification task. We present evidence of this behavior by means of a combinatorial analysis where every possible contingency matrix of 2, 3 and 4 classes classifiers are depicted on the entropy triangle, a more reliable information-theoretic tool for classification assessment. Motivated by this, we develop from first principles a measure of classification performance that takes into consideration the information learned by classifiers. We are then able to obtain the entropy-modulated accuracy (EMA, a pessimistic estimate of the expected accuracy with the influence of the input distribution factored out, and the normalized information transfer factor (NIT, a measure of how efficient is the transmission of information from the input to the output set of classes. The EMA is a more natural measure of classification performance than accuracy when the heuristic to maximize is the transfer of information through the classifier instead of classification error count. The NIT factor measures the effectiveness of the learning process in classifiers and also makes it harder for them to "cheat" using techniques like specialization, while also promoting the interpretability of results. Their use is demonstrated in a mind reading task competition that aims at decoding the identity of a video stimulus based on magnetoencephalography recordings. We show how the EMA and the NIT factor reject rankings based in accuracy, choosing more meaningful and interpretable classifiers.

  1. 100% classification accuracy considered harmful: the normalized information transfer factor explains the accuracy paradox.

    Valverde-Albacete, Francisco J; Peláez-Moreno, Carmen

    2014-01-01

    The most widely spread measure of performance, accuracy, suffers from a paradox: predictive models with a given level of accuracy may have greater predictive power than models with higher accuracy. Despite optimizing classification error rate, high accuracy models may fail to capture crucial information transfer in the classification task. We present evidence of this behavior by means of a combinatorial analysis where every possible contingency matrix of 2, 3 and 4 classes classifiers are depicted on the entropy triangle, a more reliable information-theoretic tool for classification assessment. Motivated by this, we develop from first principles a measure of classification performance that takes into consideration the information learned by classifiers. We are then able to obtain the entropy-modulated accuracy (EMA), a pessimistic estimate of the expected accuracy with the influence of the input distribution factored out, and the normalized information transfer factor (NIT), a measure of how efficient is the transmission of information from the input to the output set of classes. The EMA is a more natural measure of classification performance than accuracy when the heuristic to maximize is the transfer of information through the classifier instead of classification error count. The NIT factor measures the effectiveness of the learning process in classifiers and also makes it harder for them to "cheat" using techniques like specialization, while also promoting the interpretability of results. Their use is demonstrated in a mind reading task competition that aims at decoding the identity of a video stimulus based on magnetoencephalography recordings. We show how the EMA and the NIT factor reject rankings based in accuracy, choosing more meaningful and interpretable classifiers. PMID:24427282

  2. Accuracy in x-ray reflectivity analysis

    Tiilikainen, J; Tilli, J-M; Bosund, V; Mattila, M; Hakkarainen, T; Sormunen, J; Lipsanen, H [Micro and Nanosciences Laboratory, Helsinki University of Technology, Micronova, PO Box 3500, FI-02015 TKK (Finland)

    2007-12-07

    The influence of Poisson noise on the accuracy of x-ray reflectivity analysis is studied with an aluminium oxide (AlO) layer on silicon. A null hypothesis which argues that other than the exact solution gives the best fitness is examined with a statistical p-value test using a significance level of {alpha} = 0.01. Simulations are performed for a fit instead of a measurement since the exact error caused by noise cannot be determined from the measurement. The p-value is studied by comparing trial curves to 1000 'measurements', each of them including synthetic Poisson noise. Confidence limits for the parameters of Parratt's formalism and the Nevot-Croce approximation are determined in (mass density, surface roughness) (thickness, surface roughness) and (thickness, mass density) planes. The most significant result is that the thickness determination accuracy of AlO is approximately {+-}0.09 nm but the accuracy is better for materials having higher mass density. It is also shown that the accuracy of mass density determination can be significantly improved using a suitably designed fitness measure. Although the power of the presented method is demonstrated only in one case, it can be used in any parameter region for a plethora of single layer systems to find the lower limit of the error made in x-ray reflectivity analysis.

  3. Accuracy in x-ray reflectivity analysis

    The influence of Poisson noise on the accuracy of x-ray reflectivity analysis is studied with an aluminium oxide (AlO) layer on silicon. A null hypothesis which argues that other than the exact solution gives the best fitness is examined with a statistical p-value test using a significance level of α = 0.01. Simulations are performed for a fit instead of a measurement since the exact error caused by noise cannot be determined from the measurement. The p-value is studied by comparing trial curves to 1000 'measurements', each of them including synthetic Poisson noise. Confidence limits for the parameters of Parratt's formalism and the Nevot-Croce approximation are determined in (mass density, surface roughness) (thickness, surface roughness) and (thickness, mass density) planes. The most significant result is that the thickness determination accuracy of AlO is approximately ±0.09 nm but the accuracy is better for materials having higher mass density. It is also shown that the accuracy of mass density determination can be significantly improved using a suitably designed fitness measure. Although the power of the presented method is demonstrated only in one case, it can be used in any parameter region for a plethora of single layer systems to find the lower limit of the error made in x-ray reflectivity analysis

  4. Controlling the accuracy of chemical analysis

    Most of the IAEA reference materials are certified in intercomparisons by calculation of the overall mean of reported laboratory mean values. IAEA certification is provided at ''A level'' (satisfactory, or high degree of confidence), or at ''B level'' (acceptable, or reasonable degree of confidence) sampling , storage and preliminary processing, use of reliable analytical methods, internal and external control of accuracy and reliability result in excellent certified reference materials for inorganic, geologic, environmental, biological and other quantitative analysis by means of conventional and nuclear methods. 34 refs, 4 figs, 3 tabs

  5. The accuracy assessment in areal interpolation:An empirical investigation

    2008-01-01

    Areal interpolation is the process of transferring data from source zones to target zones. While method development remains a top research priority in areal interpo-lation,the accuracy assessment aspect also begs for attention. This paper reports an empirical experience on probing an areal interpolation method to highlight the power and potential pitfalls in accuracy assessment. A kriging-based interpolation algorithm is evaluated by several approaches. It is found that accuracy assessment is a powerful tool to understand an interpolation method,e.g. the utility of ancillary data and semi-variogram modeling in kriging in our case study. However,different assessment methods and spatial units on which assessment is conducted can lead to rather different results. The typical practice to assess accuracy at the source zone level may overestimate interpolation accuracy. Assessment at the target zone level is suggested as a supplement.

  6. Current Concept of Geometrical Accuracy

    Görög, Augustín; Görögová, Ingrid

    2014-06-01

    Within the solving VEGA 1/0615/12 research project "Influence of 5-axis grinding parameters on the shank cutteŕs geometric accuracy", the research team will measure and evaluate geometrical accuracy of the produced parts. They will use the contemporary measurement technology (for example the optical 3D scanners). During the past few years, significant changes have occurred in the field of geometrical accuracy. The objective of this contribution is to analyse the current standards in the field of geometric tolerance. It is necessary to bring an overview of the basic concepts and definitions in the field. It will prevent the use of outdated and invalidated terms and definitions in the field. The knowledge presented in the contribution will provide the new perspective of the measurement that will be evaluated according to the current standards.

  7. Current Concept of Geometrical Accuracy

    Görög Augustín

    2014-06-01

    Full Text Available Within the solving VEGA 1/0615/12 research project "Influence of 5-axis grinding parameters on the shank cutter´s geometric accuracy", the research team will measure and evaluate geometrical accuracy of the produced parts. They will use the contemporary measurement technology (for example the optical 3D scanners. During the past few years, significant changes have occurred in the field of geometrical accuracy. The objective of this contribution is to analyse the current standards in the field of geometric tolerance. It is necessary to bring an overview of the basic concepts and definitions in the field. It will prevent the use of outdated and invalidated terms and definitions in the field. The knowledge presented in the contribution will provide the new perspective of the measurement that will be evaluated according to the current standards.

  8. Accuracy of Occupational Stereotypes of Grade-Twelve Boys

    Banducci, Raymond

    1970-01-01

    The results of the study on accuracy of occupational stereotypes of grade twelve boys showed that students with high academic development had more acurate stereotypes of high level jobs than of low level jobs, and those with low academic development and low socioeconomic status had more accurate stereotypes of low level jobs. (Author)

  9. Improving Speaking Accuracy through Awareness

    Dormer, Jan Edwards

    2013-01-01

    Increased English learner accuracy can be achieved by leading students through six stages of awareness. The first three awareness stages build up students' motivation to improve, and the second three provide learners with crucial input for change. The final result is "sustained language awareness," resulting in ongoing…

  10. Radioactivity analysis of food and accuracy control

    From the fact that radioactive substances have been detected from the foods such as agricultural and livestock products and marine products due to the accident of the Fukushima Daiichi Nuclear Power Station of Tokyo Electric Power Company, the Ministry of Health, Labour and Welfare stipulated new standards geared to general foods on radioactive cesium by replacing the interim standards up to now. Various institutions began to measure radioactivity on the basis of this instruction, but as a new challenge, a problem of the reliability of the data occurred. Therefore, accuracy control to indicate the proof that the quality of the data can be retained at an appropriate level judging from an objective manner is important. In order to consecutively implement quality management activities, it is necessary for each inspection agency to build an accuracy control system. This paper introduces support service, as a new attempt, for establishing the accuracy control system. This service is offered jointly by three organizations, such as TUV Rheinland Japan Ltd., Japan Frozen Foods Inspection Corporation, and Japan Chemical Analysis Center. This service consists of the training of radioactivity measurement practitioners, proficiency test for radioactive substance measurement, and personal authentication. (O.A.)

  11. AMR, stability and higher accuracy

    Efforts to achieve better accuracy in numerical relativity have so far focused either on implementing second-order accurate adaptive mesh refinement or on defining higher order accurate differences and update schemes. Here, we argue for the combination, that is a higher order accurate adaptive scheme. This combines the power that adaptive gridding techniques provide to resolve fine scales (in addition to a more efficient use of resources) together with the higher accuracy furnished by higher order schemes when the solution is adequately resolved. To define a convenient higher order adaptive mesh refinement scheme, we discuss a few different modifications of the standard, second-order accurate approach of Berger and Oliger. Applying each of these methods to a simple model problem, we find these options have unstable modes. However, a novel approach to dealing with the grid boundaries introduced by the adaptivity appears stable and quite promising for the use of high order operators within an adaptive framework

  12. AMR, stability and higher accuracy

    Lehner, Luis [Department of Physics and Astronomy, Louisiana State University, 202 Nicholson Hall, Baton Rouge, Louisiana 70803-4001 (United States); Liebling, Steven L [Department of Physics, Long Island University-C W Post Campus, Brookville, New York 11548 (United States); Reula, Oscar [FaMAF, Universidad Nacional de Cordoba, Cordoba, 5000 (Argentina)

    2006-08-21

    Efforts to achieve better accuracy in numerical relativity have so far focused either on implementing second-order accurate adaptive mesh refinement or on defining higher order accurate differences and update schemes. Here, we argue for the combination, that is a higher order accurate adaptive scheme. This combines the power that adaptive gridding techniques provide to resolve fine scales (in addition to a more efficient use of resources) together with the higher accuracy furnished by higher order schemes when the solution is adequately resolved. To define a convenient higher order adaptive mesh refinement scheme, we discuss a few different modifications of the standard, second-order accurate approach of Berger and Oliger. Applying each of these methods to a simple model problem, we find these options have unstable modes. However, a novel approach to dealing with the grid boundaries introduced by the adaptivity appears stable and quite promising for the use of high order operators within an adaptive framework.

  13. GPS kinematics measurements accuracy testing

    Miroslav Šimčák; Vladimír Sedlák; Gabriela Nemcová

    2007-01-01

    In the paper accuracy of GPS kinematics measurements is analyzed. GPS (Global Positioning System) apparatus Stratus (Sokkia) and Pro Mark2 (Aschtech) were tested. Testing was realized on the points of the geodetic network – the testing station Badín stabilized in the Central Slovak Region nearby Banská Bystrica. The semikinematics method STOP and GO was realized from the kinematics GPS methods. The terrestrial geodetic measurements by means of using the total station Nicon 352 were also reali...

  14. Accuracy of the geodetic plans

    Kekec, Tomislav

    2011-01-01

    This thesis investigates whether it is possible to give an overall assessment of the accuracy of geodetic plan. The introductory part presents the legal basis of geodetic plan and its definition under the Regulations of Land Survey Maps and Topographic Key. The content of the geodetic plan and description of geodetic and surveying information sources which are the graphical part of geodetic plan are introduced in the second part. This part also describes the types of land survey plans, as the...

  15. Municipal water consumption forecast accuracy

    Fullerton, Thomas M.; Molina, Angel L.

    2010-06-01

    Municipal water consumption planning is an active area of research because of infrastructure construction and maintenance costs, supply constraints, and water quality assurance. In spite of that, relatively few water forecast accuracy assessments have been completed to date, although some internal documentation may exist as part of the proprietary "grey literature." This study utilizes a data set of previously published municipal consumption forecasts to partially fill that gap in the empirical water economics literature. Previously published municipal water econometric forecasts for three public utilities are examined for predictive accuracy against two random walk benchmarks commonly used in regional analyses. Descriptive metrics used to quantify forecast accuracy include root-mean-square error and Theil inequality statistics. Formal statistical assessments are completed using four-pronged error differential regression F tests. Similar to studies for other metropolitan econometric forecasts in areas with similar demographic and labor market characteristics, model predictive performances for the municipal water aggregates in this effort are mixed for each of the municipalities included in the sample. Given the competitiveness of the benchmarks, analysts should employ care when utilizing econometric forecasts of municipal water consumption for planning purposes, comparing them to recent historical observations and trends to insure reliability. Comparative results using data from other markets, including regions facing differing labor and demographic conditions, would also be helpful.

  16. Do Shared Interests Affect the Accuracy of Budgets?

    Ilse Maria Beuren; Franciele Beck; Fabiane Popik

    2015-01-01

    The creation of budgetary slack is a phenomenon associated with various behavioral aspects. This study focuses on accuracy in budgeting when the benefit of the slack is shared between the unit manager and his/her assistant. In this study, accuracy is measured by the level of slack in the budget, and the benefit of slack represents a financial consideration for the manager and the assistant. The study aims to test how shared interests in budgetary slack affect the accuracy of budget reports in...

  17. Precise Computation of Position Accuracy in GNSS Systems

    Garrido, Juan Pablo Boyero

    2011-01-01

    Accuracy and Availability computations for a GNSS System - or combination of Systems - through Service Volume Simulations take considerable time. Therefore, the computation of the accuracy in 2D and 3D are often simplified by an approximate solution. The drawback is that such simplifications can lead to accuracy results that are too conservative (up to 25% in the 2D case and up to 43% in the 3D case, for a 95% confidence level), which in turn translates into pessimistic System Availability. T...

  18. Required accuracy and dose thresholds in individual monitoring

    Christensen, P.; Griffith, R.V.

    specification of detailed accuracy requirements which are needed in practical routine monitoring. The ICRP overall accuracy requirement is defined as an allowable maximum uncertainty factor at the 95% confidence level for a single measurement of the relevant dose quantity, i.e. H(p)(10) and H(p)(0.07). From......The paper follows the approach given in recent revisions of CEC and IAEA recommendations on requirements in individual monitoring for external radiations. The ICRP requirements on overall accuracy for individual monitoring, as given in ICRP Publication 35 (1982), form the basis for the...

  19. Speed accuracy trade-off under response deadlines

    Balcı, Fuat; Karşılar, Hakan; Simen, Patrick; Papadakis, Samantha

    2014-01-01

    Abstract The majority of two-alternative forced choice (2AFC) psychophysics studies have examined speed-accuracy trade-offs either in free-response or fixed viewing time paradigms with no hard time constraints on responding. Under response deadlines, reward maximization requires participants to modulate decision thresholds over the course of a trial such that when the deadline arrives a response is ensured despite the possible reduction of accuracy to the chance level. Importantly, this no...

  20. On the accuracy of judgmental interventions on forecasting support systems

    Nikolopoulos, K.; Lawrence, M.; Goodwin, P; R A Fildes

    2005-01-01

    Forecasting at the Stock Keeping Unit (SKU) disaggregate level in order to support operations management has proved a very difficult task. The levels of accuracy achieved have major consequences for companies at all levels in the supply chain; errors at each stage are amplified resulting in poor service and overly high inventory levels. In most companies, the size and complexity of the forecasting task necessitates the use of Forecasting Support Systems (FSS). The present study examines month...

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

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

    2016-01-01

    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. PMID:27338408

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

    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.

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

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

    2016-01-01

    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. PMID:27338408

  4. Required accuracy and dose thresholds in individual monitoring

    Christensen, P.; Griffith, R.V.

    1994-01-01

    The paper follows the approach given in recent revisions of CEC and IAEA recommendations on requirements in individual monitoring for external radiations. The ICRP requirements on overall accuracy for individual monitoring, as given in ICRP Publication 35 (1982), form the basis for the...... specification of detailed accuracy requirements which are needed in practical routine monitoring. The ICRP overall accuracy requirement is defined as an allowable maximum uncertainty factor at the 95% confidence level for a single measurement of the relevant dose quantity, i.e. H(p)(10) and H(p)(0.07). From...... this uncertainty factor, a value of 21% can be evaluated for the allowable maximum overall standard deviation for dose measurements at dose levels near the annual dose limits increasing to 45% for dose levels at the lower end of the dose range required to be monitored. A method is described for...

  5. Curation accuracy of model organism databases.

    Keseler, Ingrid M; Skrzypek, Marek; Weerasinghe, Deepika; Chen, Albert Y; Fulcher, Carol; Li, Gene-Wei; Lemmer, Kimberly C; Mladinich, Katherine M; Chow, Edmond D; Sherlock, Gavin; Karp, Peter D

    2014-01-01

    Manual extraction of information from the biomedical literature-or biocuration-is the central methodology used to construct many biological databases. For example, the UniProt protein database, the EcoCyc Escherichia coli database and the Candida Genome Database (CGD) are all based on biocuration. Biological databases are used extensively by life science researchers, as online encyclopedias, as aids in the interpretation of new experimental data and as golden standards for the development of new bioinformatics algorithms. Although manual curation has been assumed to be highly accurate, we are aware of only one previous study of biocuration accuracy. We assessed the accuracy of EcoCyc and CGD by manually selecting curated assertions within randomly chosen EcoCyc and CGD gene pages and by then validating that the data found in the referenced publications supported those assertions. A database assertion is considered to be in error if that assertion could not be found in the publication cited for that assertion. We identified 10 errors in the 633 facts that we validated across the two databases, for an overall error rate of 1.58%, and individual error rates of 1.82% for CGD and 1.40% for EcoCyc. These data suggest that manual curation of the experimental literature by Ph.D-level scientists is highly accurate. Database URL: http://ecocyc.org/, http://www.candidagenome.org// PMID:24923819

  6. The IBIS / ISGRI Source Location Accuracy

    Gros, A; Soldi, S; Gotz, D; Caballero, I; Mattana, F; Heras, J A Zurita

    2013-01-01

    We present here results on the source location accuracy of the INTEGRAL IBIS/ISGRI coded mask telescope, based on ten years of INTEGRAL data and on recent developments in the data analysis procedures. Data were selected and processed with the new Off-line Scientific Analysis pipeline (OSA10.0) that benefits from the most accurate background corrections, the most performing coding noise cleaning and sky reconstruction algorithms available. We obtained updated parameters for the evaluation of the point source location error from the source signal to noise ratio. These results are compared to previous estimates and to theoretical expectations. Also thanks to a new fitting procedure the typical error at 90% confidence level for a source at a signal to noise of 10 is now estimated to be 1.5 arcmin. Prospects for future analysis on the Point Spread Function fitting procedure and on the evaluation of residual biases are also presented. The new consolidated parameters describing the source location accuracy that will...

  7. Accuracy of the blood pressure measurement.

    Rabbia, F; Del Colle, S; Testa, E; Naso, D; Veglio, F

    2006-08-01

    Blood pressure measurement is the cornerstone for the diagnosis, the treatment and the research on arterial hypertension, and all of the decisions about one of these single aspects may be dramatically influenced by the accuracy of the measurement. Over the past 20 years or so, the accuracy of the conventional Riva-Rocci/Korotkoff technique of blood pressure measurement has been questioned and efforts have been made to improve the technique with automated devices. In the same period, recognition of the phenomenon of white coat hypertension, whereby some individuals with an apparent increase in blood pressure have normal, or reduced, blood pressures when measurement is repeated away from the medical environment, has focused attention on methods of measurement that provide profiles of blood pressure behavior rather than relying on isolated measurements under circumstances that may in themselves influence the level of blood pressure recorded. These methodologies have included repeated measurements of blood pressure using the traditional technique, self-measurement of blood pressure in the home or work place, and ambulatory blood pressure measurement using innovative automated devices. The purpose of this review to serve as a source of practical information about the commonly used methods for blood pressure measurement: the traditional Riva-Rocci method and the automated methods. PMID:17016412

  8. Enhancing Accuracy of Plant Leaf Classification Techniques

    C. S. Sumathi

    2014-03-01

    Full Text Available Plants have become an important source of energy, and are a fundamental piece in the puzzle to solve the problem of global warming. Living beings also depend on plants for their food, hence it is of great importance to know about the plants growing around us and to preserve them. Automatic plant leaf classification is widely researched. This paper investigates the efficiency of learning algorithms of MLP for plant leaf classification. Incremental back propagation, Levenberg–Marquardt and batch propagation learning algorithms are investigated. Plant leaf images are examined using three different Multi-Layer Perceptron (MLP modelling techniques. Back propagation done in batch manner increases the accuracy of plant leaf classification. Results reveal that batch training is faster and more accurate than MLP with incremental training and Levenberg– Marquardt based learning for plant leaf classification. Various levels of semi-batch training used on 9 species of 15 sample each, a total of 135 instances show a roughly linear increase in classification accuracy.

  9. Narrow-width approximation accuracy

    A study of general properties of the narrow-width approximation (NWA) with polarization/spin decorrelation is presented. We prove for sufficiently inclusive differential rates of arbitrary resonant decay or scattering processes with an on-shell intermediate state decaying via a cubic or quartic vertex that decorrelation effects vanish and the NWA is of order Γ. Its accuracy is then determined numerically for all resonant 3-body decays involving scalars, spin-1/2 fermions or vector bosons. We specialize the general results to MSSM benchmark scenarios. Significant off-shell corrections can occur - similar in size to QCD corrections. We qualify the configurations in which a combined consideration is advisable. For this purpose, we also investigate process-independent methods to improve the NWA

  10. Increasing Accuracy in Environmental Measurements

    Jacksier, Tracey; Fernandes, Adelino; Matthew, Matt; Lehmann, Horst

    2016-04-01

    Human activity is increasing the concentrations of green house gases (GHG) in the atmosphere which results in temperature increases. High precision is a key requirement of atmospheric measurements to study the global carbon cycle and its effect on climate change. Natural air containing stable isotopes are used in GHG monitoring to calibrate analytical equipment. This presentation will examine the natural air and isotopic mixture preparation process, for both molecular and isotopic concentrations, for a range of components and delta values. The role of precisely characterized source material will be presented. Analysis of individual cylinders within multiple batches will be presented to demonstrate the ability to dynamically fill multiple cylinders containing identical compositions without isotopic fractionation. Additional emphasis will focus on the ability to adjust isotope ratios to more closely bracket sample types without the reliance on combusting naturally occurring materials, thereby improving analytical accuracy.

  11. Accuracy - a market in radiotherapy. Reasons, requirements, clinical practice

    Accuracy requirements are specified in accordance with survival curves drawn up on the basis of clinical experience and data. Sigmoidal dose-response curves are established with the aid of the survival curves, giving information on tumour decline and the radiation effects induced in patients. In accordance with the ICRU report of 1984, Quality Assurance of External Beam Therapy, accuracy verification takes into account the two different criteria of tolerance level and action level. The dosimetric overall uncertainty is to be kept below 8 p.c. (DG)

  12. 广西壮族地区10~16岁学生儿童虐待状况调查分析%Investigation of child abuse in 10-16 years old students in Zhuang nationality areas of Guangxi

    刘萍; 李春灵; 宋媛; 蔡秋玲

    2014-01-01

    目的:了解壮族地区10~16岁学生儿童虐待流行状况,为探讨儿童虐待发生的影响因素、制定适合民族文化背景的预防干预措施提供参考依据。方法选取经济发展处于好、中、差水平的壮族聚居县各1个,抽取10~16岁中小学生共3936人。采用学生基本情况调查表收集学生个人及家庭基本情况。使用儿童受虐筛查表(SQCA)进行儿童虐待情况筛查。结果广西壮族地区中小学生儿童虐待(CA)筛查阳性率为29.3%。好、中、差经济水平县的 CA 筛查阳性率分别为22.8%、31.6%和33.9%,差别有统计学意义(P<0.01)。城乡 CA 筛查阳性率分别为30.7%和27.9%,差别无统计学意义(P >0.05);小学阶段和中学阶段CA筛查阳性率分别为41.8%和17.7%,差别有统计学意义(P<0.05);男女生CA筛查阳性率分别为30.8%和27.8%,差别有统计学意义(P<0.05)。结论广西壮族地区学生有随着年龄增长虐待筛查阳性率下降的趋势,儿童虐待可能与地区经济发展水平有关。%Objective To understand the epidemiological features and associated factors of child abuse in students aged 10-16 years old in Zhuang nationality areas of Guangxi, to explore intervence measures for prevention child abuse with special national culture. Method Students aged 10~16 years old were sampled from each county of high, middle and low economic level, which were dominated by Zhuang population. Questionnaire suvery was conducted on a total number of 3 936 students for personal and family general information. The child abuse satus was screened by the Screen Questionnaire of Child Abuse (SQCA). Results The prevalence of child abuse in sampled students was 29.3%. The prevalences of child abuse in high, middle and low economic level county were 22.8%, 31.6% and 33.9%, respectively; there were statistical significance among them(P0.05). The prevalences of child abuse in primary school

  13. Data accuracy assessment using enterprise architecture

    Närman, Per; Holm, Hannes; Johnson, Pontus; König, Johan; Chenine, Moustafa; Ekstedt, Mathias

    2011-02-01

    Errors in business processes result in poor data accuracy. This article proposes an architecture analysis method which utilises ArchiMate and the Probabilistic Relational Model formalism to model and analyse data accuracy. Since the resources available for architecture analysis are usually quite scarce, the method advocates interviews as the primary data collection technique. A case study demonstrates that the method yields correct data accuracy estimates and is more resource-efficient than a competing sampling-based data accuracy estimation method.

  14. Dosimetric accuracy of a staged radiosurgery treatment

    Cernica, George; de Boer, Steven F.; Diaz, Aidnag; Fenstermaker, Robert A.; Podgorsak, Matthew B.

    2005-05-01

    For large cerebral arteriovenous malformations (AVMs), the efficacy of radiosurgery is limited since the large doses necessary to produce obliteration may increase the risk of radiation necrosis to unacceptable levels. An alternative is to stage the radiosurgery procedure over multiple stages (usually two), effectively irradiating a smaller volume of the AVM nidus with a therapeutic dose during each session. The difference between coordinate systems defined by sequential stereotactic frame placements can be represented by a translation and a rotation. A unique transformation can be determined based on the coordinates of several fiducial markers fixed to the skull and imaged in each stereotactic coordinate system. Using this transformation matrix, isocentre coordinates from the first stage can be displayed in the coordinate system of subsequent stages allowing computation of a combined dose distribution covering the entire AVM. The accuracy of this approach was tested on an anthropomorphic head phantom and was verified dosimetrically. Subtle defects in the phantom were used as control points, and 2 mm diameter steel balls attached to the surface were used as fiducial markers and reference points. CT images (2 mm thick) were acquired. Using a transformation matrix developed with two frame placements, the predicted locations of control and reference points had an average error of 0.6 mm near the fiducial markers and 1.0 mm near the control points. Dose distributions in a staged treatment approach were accurately calculated using the transformation matrix. This approach is simple, fast and accurate. Errors were small and clinically acceptable for Gamma Knife radiosurgery. Accuracy can be improved by reducing the CT slice thickness.

  15. Cued Speech Transliteration: Effects of Speaking Rate and Lag Time on Production Accuracy.

    Krause, Jean C; Tessler, Morgan P

    2016-10-01

    Many deaf and hard-of-hearing children rely on interpreters to access classroom communication. Although the exact level of access provided by interpreters in these settings is unknown, it is likely to depend heavily on interpreter accuracy (portion of message correctly produced by the interpreter) and the factors that govern interpreter accuracy. In this study, the accuracy of 12 Cued Speech (CS) transliterators with varying degrees of experience was examined at three different speaking rates (slow, normal, fast). Accuracy was measured with a high-resolution, objective metric in order to facilitate quantitative analyses of the effect of each factor on accuracy. Results showed that speaking rate had a large negative effect on accuracy, caused primarily by an increase in omitted cues, whereas the effect of lag time on accuracy, also negative, was quite small and explained just 3% of the variance. Increased experience level was generally associated with increased accuracy; however, high levels of experience did not guarantee high levels of accuracy. Finally, the overall accuracy of the 12 transliterators, 54% on average across all three factors, was low enough to raise serious concerns about the quality of CS transliteration services that (at least some) children receive in educational settings. PMID:27221370

  16. Evaluation of radiographers’ mammography screen-reading accuracy in Australia

    Debono, Josephine C, E-mail: josephine.debono@bci.org.au [Westmead Breast Cancer Institute, Westmead, New South Wales (Australia); Poulos, Ann E [Discipline of Medical Radiation Sciences, Faculty of Health Sciences, University of Sydney, Lidcombe, New South Wales (Australia); Houssami, Nehmat [Screening and Test Evaluation Program, School of Public Health (A27), Sydney Medical School, University of Sydney, Sydney, New South Wales (Australia); Turner, Robin M [School of Public Health and Community Medicine, University of New South Wales, Sydney, New South Wales (Australia); Boyages, John [Macquarie University Cancer Institute, Macquarie University Hospital, Australian School of Advanced Medicine, Macquarie University, Sydney, New South Wales (Australia); Westmead Breast Cancer Institute, Westmead, New South Wales (Australia)

    2015-03-15

    This study aimed to evaluate the accuracy of radiographers’ screen-reading mammograms. Currently, radiologist workforce shortages may be compromising the BreastScreen Australia screening program goal to detect early breast cancer. The solution to a similar problem in the United Kingdom has successfully encouraged radiographers to take on the role as one of two screen-readers. Prior to consideration of this strategy in Australia, educational and experiential differences between radiographers in the United Kingdom and Australia emphasise the need for an investigation of Australian radiographers’ screen-reading accuracy. Ten radiographers employed by the Westmead Breast Cancer Institute with a range of radiographic (median = 28 years), mammographic (median = 13 years) and BreastScreen (median = 8 years) experience were recruited to blindly and independently screen-read an image test set of 500 mammograms, without formal training. The radiographers indicated the presence of an abnormality using BI-RADS®. Accuracy was determined by comparison with the gold standard of known outcomes of pathology results, interval matching and client 6-year follow-up. Individual sensitivity and specificity levels ranged between 76.0% and 92.0%, and 74.8% and 96.2% respectively. Pooled screen-reader accuracy across the radiographers estimated sensitivity as 82.2% and specificity as 89.5%. Areas under the reading operating characteristic curve ranged between 0.842 and 0.923. This sample of radiographers in an Australian setting have adequate accuracy levels when screen-reading mammograms. It is expected that with formal screen-reading training, accuracy levels will improve, and with support, radiographers have the potential to be one of the two screen-readers in the BreastScreen Australia program, contributing to timeliness and improved program outcomes.

  17. Evaluation of radiographers’ mammography screen-reading accuracy in Australia

    This study aimed to evaluate the accuracy of radiographers’ screen-reading mammograms. Currently, radiologist workforce shortages may be compromising the BreastScreen Australia screening program goal to detect early breast cancer. The solution to a similar problem in the United Kingdom has successfully encouraged radiographers to take on the role as one of two screen-readers. Prior to consideration of this strategy in Australia, educational and experiential differences between radiographers in the United Kingdom and Australia emphasise the need for an investigation of Australian radiographers’ screen-reading accuracy. Ten radiographers employed by the Westmead Breast Cancer Institute with a range of radiographic (median = 28 years), mammographic (median = 13 years) and BreastScreen (median = 8 years) experience were recruited to blindly and independently screen-read an image test set of 500 mammograms, without formal training. The radiographers indicated the presence of an abnormality using BI-RADS®. Accuracy was determined by comparison with the gold standard of known outcomes of pathology results, interval matching and client 6-year follow-up. Individual sensitivity and specificity levels ranged between 76.0% and 92.0%, and 74.8% and 96.2% respectively. Pooled screen-reader accuracy across the radiographers estimated sensitivity as 82.2% and specificity as 89.5%. Areas under the reading operating characteristic curve ranged between 0.842 and 0.923. This sample of radiographers in an Australian setting have adequate accuracy levels when screen-reading mammograms. It is expected that with formal screen-reading training, accuracy levels will improve, and with support, radiographers have the potential to be one of the two screen-readers in the BreastScreen Australia program, contributing to timeliness and improved program outcomes

  18. Tracking accuracy assessment for concentrator photovoltaic systems

    Norton, Matthew S. H.; Anstey, Ben; Bentley, Roger W.; Georghiou, George E.

    2010-10-01

    The accuracy to which a concentrator photovoltaic (CPV) system can track the sun is an important parameter that influences a number of measurements that indicate the performance efficiency of the system. This paper presents work carried out into determining the tracking accuracy of a CPV system, and illustrates the steps involved in gaining an understanding of the tracking accuracy. A Trac-Stat SL1 accuracy monitor has been used in the determination of pointing accuracy and has been integrated into the outdoor CPV module test facility at the Photovoltaic Technology Laboratories in Nicosia, Cyprus. Results from this work are provided to demonstrate how important performance indicators may be presented, and how the reliability of results is improved through the deployment of such accuracy monitors. Finally, recommendations on the use of such sensors are provided as a means to improve the interpretation of real outdoor performance.

  19. Accuracy of GIPSY PPP from a denser network

    Gokhan Hayal, Adem; Ugur Sanli, Dogan

    2015-04-01

    Researchers need to know about the accuracy of GPS for the planning of their field survey and hence to obtain reliable positions as well as deformation rates. Geophysical applications such as monitoring of development of a fault creep or of crustal motion for global sea level rise studies necessitate the use of continuous GPS whereas applications such as determining co-seismic displacements where permanent GPS sites are sparsely scattered require the employment of episodic campaigns. Recently, real time applications of GPS in relation to the early prediction of earthquakes and tsunamis are in concern. Studying the static positioning accuracy of GPS has been of interest to researchers for more than a decade now. Various software packages and modeling strategies have been tested so far. Relative positioning accuracy was compared with PPP accuracy. For relative positioning, observing session duration and network geometry of reference stations appear to be the dominant factors on GPS accuracy whereas observing session duration seems to be the only factor influencing the PPP accuracy. We believe that latest developments concerning the accuracy of static GPS from well-established software will form a basis for the quality of GPS field works mentioned above especially for real time applications which are referred to more frequently nowadays. To assess the GPS accuracy, conventionally some 10 to 30 regionally or globally scattered networks of GPS stations are used. In this study, we enlarge the size of GPS network up to 70 globally scattered IGS stations to observe the changes on our previous accuracy modeling which employed only 13 stations. We use the latest version 6.3 of GIPSY/OASIS II software and download the data from SOPAC archives. Noting the effect of the ionosphere on our previous accuracy modeling, here we selected the GPS days through which the k-index values are lower than 4. This enabled us to extend the interval of observing session duration used for the

  20. Do Shared Interests Affect the Accuracy of Budgets?

    Ilse Maria Beuren

    2015-04-01

    Full Text Available The creation of budgetary slack is a phenomenon associated with various behavioral aspects. This study focuses on accuracy in budgeting when the benefit of the slack is shared between the unit manager and his/her assistant. In this study, accuracy is measured by the level of slack in the budget, and the benefit of slack represents a financial consideration for the manager and the assistant. The study aims to test how shared interests in budgetary slack affect the accuracy of budget reports in an organization. To this end, an experimental study was conducted with a sample of 90 employees in management and other leadership positions at a cooperative that has a variable compensation plan based on the achievement of organizational goals. The experiment conducted in this study is consubstantiated by the study of Church, Hannan and Kuang (2012, which was conducted with a sample of undergraduate students in the United States and used a quantitative approach to analyze the results. In the first part of the experiment, the results show that when budgetary slack is not shared, managers tend to create greater slack when the assistant is not aware of the creation of slack; these managers thus generate a lower accuracy index than managers whose assistants are aware of the creation of slack. When budgetary slack is shared, there is higher average slack when the assistant is aware of the creation of slack. In the second part of the experiment, the accuracy index is higher for managers who prepare the budget with the knowledge that their assistants prefer larger slack values. However, the accuracy level differs between managers who know that their assistants prefer maximizing slack values and managers who do not know their assistants' preference regarding slack. These results contribute to the literature by presenting evidence of managers' behavior in the creation of budgetary slack in scenarios in which they share the benefits of slack with their assistants.

  1. Diagnostic Accuracy of Procalcitonin in Bacterial Meningitis Versus Nonbacterial Meningitis

    Wei, Ting-Ting; Hu, Zhi-De; Qin, Bao-Dong; Ma, Ning; Tang, Qing-Qin; Wang, Li-Li; Zhou, Lin; Zhong, Ren-Qian

    2016-01-01

    Abstract Several studies have investigated the diagnostic accuracy of procalcitonin (PCT) levels in blood or cerebrospinal fluid (CSF) in bacterial meningitis (BM), but the results were heterogeneous. The aim of the present study was to ascertain the diagnostic accuracy of PCT as a marker for BM detection. A systematic search of the EMBASE, Scopus, Web of Science, and PubMed databases was performed to identify studies published before December 7, 2015 investigating the diagnostic accuracy of PCT for BM. The quality of the eligible studies was assessed using the revised Quality Assessment for Studies of Diagnostic Accuracy method. The overall diagnostic accuracy of PCT detection in CSF or blood was pooled using the bivariate model. Twenty-two studies involving 2058 subjects were included in this systematic review and meta-analysis. The overall specificities and sensitivities were 0.86 and 0.80 for CSF PCT, and 0.97 and 0.95 for blood PCT, respectively. Areas under the summary receiver operating characteristic curves were 0.90 and 0.98 for CSF PCT and blood PCT, respectively. The major limitation of this systematic review and meta-analysis was the small number of studies included and the heterogeneous diagnostic thresholds adopted by eligible studies. Our meta-analysis shows that PCT is a useful biomarker for BM diagnosis. PMID:26986140

  2. Accuracy analysis of distributed simulation systems

    Lin, Qi; Guo, Jing

    2010-08-01

    Existed simulation works always emphasize on procedural verification, which put too much focus on the simulation models instead of simulation itself. As a result, researches on improving simulation accuracy are always limited in individual aspects. As accuracy is the key in simulation credibility assessment and fidelity study, it is important to give an all-round discussion of the accuracy of distributed simulation systems themselves. First, the major elements of distributed simulation systems are summarized, which can be used as the specific basis of definition, classification and description of accuracy of distributed simulation systems. In Part 2, the framework of accuracy of distributed simulation systems is presented in a comprehensive way, which makes it more sensible to analyze and assess the uncertainty of distributed simulation systems. The concept of accuracy of distributed simulation systems is divided into 4 other factors and analyzed respectively further more in Part 3. In Part 4, based on the formalized description of framework of accuracy analysis in distributed simulation systems, the practical approach are put forward, which can be applied to study unexpected or inaccurate simulation results. Following this, a real distributed simulation system based on HLA is taken as an example to verify the usefulness of the approach proposed. The results show that the method works well and is applicable in accuracy analysis of distributed simulation systems.

  3. Audiovisual biofeedback improves motion prediction accuracy

    Pollock, Sean; Lee, Danny; Keall, Paul; Kim, Taeho

    2013-01-01

    Purpose: The accuracy of motion prediction, utilized to overcome the system latency of motion management radiotherapy systems, is hampered by irregularities present in the patients’ respiratory pattern. Audiovisual (AV) biofeedback has been shown to reduce respiratory irregularities. The aim of this study was to test the hypothesis that AV biofeedback improves the accuracy of motion prediction.

  4. Optimizing the geometrical accuracy of curvilinear meshes

    Toulorge, Thomas; Remacle, Jean-François

    2015-01-01

    This paper presents a method to generate valid high order meshes with optimized geometrical accuracy. The high order meshing procedure starts with a linear mesh, that is subsequently curved without taking care of the validity of the high order elements. An optimization procedure is then used to both untangle invalid elements and optimize the geometrical accuracy of the mesh. Standard measures of the distance between curves are considered to evaluate the geometrical accuracy in planar two-dimensional meshes, but they prove computationally too costly for optimization purposes. A fast estimate of the geometrical accuracy, based on Taylor expansions of the curves, is introduced. An unconstrained optimization procedure based on this estimate is shown to yield significant improvements in the geometrical accuracy of high order meshes, as measured by the standard Haudorff distance between the geometrical model and the mesh. Several examples illustrate the beneficial impact of this method on CFD solutions, with a part...

  5. Evaluation on the accuracy of digital elevation models

    2001-01-01

    There is a growing interest in investigating the accuracy of digital elevation model (DEM). However people usually have an unbalanced view on DEM errors. They emphasize DEM sampling errors, but ignore the impact of DEM resolution and terrain roughness on the accuracy of terrain representation. This research puts forward the concept of DEM terrain representation error (Et) and then investigates the generation, factors, measurement and simulation of DEM terrain representation errors. A multi-resolution and multi-relief comparative approach is used as the major methodology in this research. The experiment reveals a quantitative relationship between the error and the variation of resolution and terrain roughness at a global level. Root mean square error (RMS Et) is regressed against surface profile curvature (V) and DEM resolution (R) at 10 resolution levels. It is found that the RMS Et may be expressed as RMS Et = (0.0061· V+ 0.0052) . R - 0.022·V +0.2415. This result may be very useful in forecasting DEM accuracy, as well as in determining the DEM resolution related to the accuracy requirement of particular application.

  6. Noise levels in Damascus city

    Outdoor noise levels were measured at 22 sites in Damascus city. Sound level meter model NC-10 with a 20-140 dBA selectable range was used in the current investigation. At each site noise data were collected from 7 to 21 o'clock. The results showed that the noise levels were higher than WHO (World Health Organization) standard by 5-24.7 dB, 10-16 dB, 10-11 dB and 12-17 dB in residential, commercial, Commercial-industrial, and Heavy traffic streets respectively. Indoor and outdoor noise levels in some hospitals were higher than WHO standard by 15-28 dB and 19-23 dB respectively. The study showed that the authorities administration must take necessary procedures to reduce the noise levels in residential regions and in the regions surrounding the hospitals. (author)

  7. Accuracy and consistency of modern elastomeric pumps.

    Weisman, Robyn S; Missair, Andres; Pham, Phung; Gutierrez, Juan F; Gebhard, Ralf E

    2014-01-01

    Continuous peripheral nerve blockade has become a popular method of achieving postoperative analgesia for many surgical procedures. The safety and reliability of infusion pumps are dependent on their flow rate accuracy and consistency. Knowledge of pump rate profiles can help physicians determine which infusion pump is best suited for their clinical applications and specific patient population. Several studies have investigated the accuracy of portable infusion pumps. Using methodology similar to that used by Ilfeld et al, we investigated the accuracy and consistency of several current elastomeric pumps. PMID:25140510

  8. ACCURACY OF DIVIDEND DISCOUNT MODEL VALUATION AT MACEDONIAN STOCK- EXCHANGE

    Zoran Ivanovski; Zoran Narasanov; Nadica Ivanovska

    2015-01-01

    Many analysts believed that Dividend Discount Model (DDM) is obsolete, but much of the intuition that drives discounted cash flow (DCF) valuation is embedded in the DDM model. The basic task of these research is to test DDM valuation models accuracy at Macedonian Stock Exchange (MSE) as emerging market by analyzing two “blue-chip” stocks, one from banking sector and other from industry. The descriptive statistics and regression analysis were used to determine the level of correlation between ...

  9. Improving Coverage Accuracy of Block Bootstrap Confidence Intervals

    Lee, Stephen M. S.; Lai, P. Y.

    2008-01-01

    The block bootstrap confidence interval based on dependent data can outperform the computationally more convenient normal approximation only with non-trivial Studentization which, in the case of complicated statistics, calls for highly specialist treatment. We propose two different approaches to improving the accuracy of the block bootstrap confidence interval under very general conditions. The first calibrates the coverage level by iterating the block bootstrap. The second calculates Student...

  10. The analysis accuracy assessment of CORINE land cover in the Iberian coast

    Romano Grullón, Ramona Yraida; Alhaddad, Bahaa Eddin; Roca Cladera, Josep

    2009-01-01

    OBJECTIVES: 1. Evaluate databases accuracy of Corine land cover; 2. Present methods to test map error which help to explain the observed differences between various categories of land covers; 3. Explain the observed differences between various data sources in different scale levels; 4. Calculate the accuracy assessments. Peer Reviewed

  11. Hostility and Facial Affect Recognition: Effects of a Cold Pressor Stressor on Accuracy and Cardiovascular Reactivity

    Herridge, Matt L.; Harrison, David W.; Mollet, Gina A.; Shenal, Brian V.

    2004-01-01

    The effects of hostility and a cold pressor stressor on the accuracy of facial affect perception were examined in the present experiment. A mechanism whereby physiological arousal level is mediated by systems which also mediate accuracy of an individual's interpretation of affective cues is described. Right-handed participants were classified as…

  12. Executive Functioning and Memory as Potential Mediators of the Episodic Feeling-of-Knowing Accuracy

    Perrotin, Audrey; Tournelle, Lydia; Isingrini, Michel

    2008-01-01

    The study focused on the cognitive determinants of the accuracy of feeling-of-knowing (FOK) judgments made on episodic memory information. An individual differences approach was used on a sample of healthy older adults assessed on an episodic FOK task and on several neuropsychological measures. At a global level of analysis of FOK accuracy, the…

  13. Critical thinking and accuracy of nurses' diagnoses.

    Lunney, Margaret

    2003-01-01

    Interpretations of patient data are complex and diverse, contributing to a risk of low accuracy nursing diagnoses. This risk is confirmed in research findings that accuracy of nurses' diagnoses varied widely from high to low. Highly accurate diagnoses are essential, however, to guide nursing interventions for the achievement of positive health outcomes. Development of critical thinking abilities is likely to improve accuracy of nurses' diagnoses. New views of critical thinking serve as a basis for critical thinking in nursing. Seven cognitive skills and ten habits of mind are identified as dimensions of critical thinking for use in the diagnostic process. Application of the cognitive skills of critical thinking illustrates the importance of using critical thinking for accuracy of nurses' diagnoses. Ten strategies are proposed for self-development of critical thinking abilities. PMID:14649031

  14. Accuracy and Efficiency of Raytracing Photoionisation Algorithms

    Mackey, Jonathan

    2012-01-01

    Three non-equilibrium photoionisation algorithms for hydrodynamical grid-based simulation codes are compared in terms of accuracy, timestepping criteria, and parallel scaling. Explicit methods with first order time accuracy for photon conservation must use very restrictive timestep criteria to accurately track R-type ionisation fronts. A second order accurate algorithm is described which, although it requires more work per step, allows much longer timesteps and is consequently more efficient. Implicit methods allow ionisation fronts to cross many grid cells per timestep while maintaining photon conservation accuracy. It is shown, however, that errors are much larger for multi-frequency radiation then for monochromatic radiation with the implicit algorithm used here, and large errors accrue when an ionisation front crosses many optical depths in a single step. The accuracy and convergence rates of the different algorithms are tested with a large number of timestepping criteria to identify the best criterion fo...

  15. Precise extension-mode resonant sensor with uniform and repeatable sensitivity for detection of ppm-level ammonia

    This paper presents a micromechanical resonant gas sensor, which is operated in extensional bulk mode, for high-accuracy sensing of ultra-low concentration chemical vapors. The designed and fabricated gravimetric resonant microsensor has exhibited both high Q-factor of 11157 in air and high mass sensitivity of 10.16 Hz pg−1. Much more importantly, both theoretical analysis and sensing experiment have verified that such an extensional resonance mode is technically advantageous in sensing accuracy (e.g., output signal linearity in terms of gas concentration and reproducibility of sensitivity), which can be attributed to the uniform vibration amplitude at each point of the gas-adsorbing area. Loaded with –COOH functionalized mesoporous-silica nanopaticles as sensing material, which features an ultra-large surface area, the chemical sensing micro-resonator experimentally performs precise detection performance to ppm-level ammonia vapor. The limit of detection is as low as 1 ppm and the response time of the sensor is as short as 10 s. (paper)

  16. Required accuracy and dose thresholds in individual monitoring

    The paper follows the approach given in recent revisions of CEC and IAEA recommendations on requirements in individual monitoring for external radiations. The ICRP requirements on overall accuracy for individual monitoring, as given in ICRP Publications 35 (1982), form the basis for the specification of detailed accuracy requirements which are needed in practical routine monitoring. The ICRP overall accuracy requirement is defined as an allowable maximum uncertainty factor at the 95% confidence level for a single measurement of the relevant dose quantity, i.e. Hp(10) and Hp(0.07). From this uncertainty factor, a value of 21% can be evaluated for the allowable maximum overall standard deviation for dose measurements at dose levels near the annual dose limits increasing to 45% for dose levels at the lower end of the dose range required to be monitored. A method is described for evaluating the overall standard deviation of the dosimetry system by combining random and systematic uncertainties in quadrature, and procedures are also given for determining each individual uncertainty connected to the dose measurement. In particular, attention is paid to the evaluation of the combined uncertainty due to energy and angular dependencies of the dosemeter. (Author)

  17. Moyamoya disease: diagnostic accuracy of MRI

    MRI may be employed to investigate moyamoya disease, since it provides vascular information without use of contrast medium. We reported the usefulness and limitations of MR angiography (MRA) in moyamoya disease. To our knowledge, no report has appeared dealing with the diagnostic accuracy of MRI in a large number of cases of moyamoya disease, although MRI is used more commonly than MRA. We therefore undertook to evaluate the accuracy of MRI in moyamoya disease. (orig.)

  18. Coding accuracy on the psychophysical scale

    Lubomir Kostal; Petr Lansky

    2016-01-01

    Sensory neurons are often reported to adjust their coding accuracy to the stimulus statistics. The observed match is not always perfect and the maximal accuracy does not align with the most frequent stimuli. As an alternative to a physiological explanation we show that the match critically depends on the chosen stimulus measurement scale. More generally, we argue that if we measure the stimulus intensity on the scale which is proportional to the perception intensity, an improved adjustment in...

  19. Development of an artillery accuracy model

    Fann, Chee Meng.

    2006-01-01

    This thesis explains the methodologies that predict the trajectory and accuracy of an unguided, indirect-fire launched projectile in predicted fire. The trajectory is the path that a projectile travels to the impact point, while the accuracy is the measurement of the deviation of the impact point from the target. In addition, this thesis describes, the methodology for calculating the various factors such as drag and drift in the trajectory calculation. A three degree of freedom model will...

  20. Factors Influencing Science Content Accuracy in Elementary Inquiry Science Lessons

    Nowicki, Barbara L.; Sullivan-Watts, Barbara; Shim, Minsuk K.; Young, Betty; Pockalny, Robert

    2013-06-01

    Elementary teachers face increasing demands to engage children in authentic science process and argument while simultaneously preparing them with knowledge of science facts, vocabulary, and concepts. This reform is particularly challenging due to concerns that elementary teachers lack adequate science background to teach science accurately. This study examined 81 in-classroom inquiry science lessons for preservice education majors and their cooperating teachers to determine the accuracy of the science content delivered in elementary classrooms. Our results showed that 74 % of experienced teachers and 50 % of student teachers presented science lessons with greater than 90 % accuracy. Eleven of the 81 lessons (9 preservice, 2 cooperating teachers) failed to deliver accurate science content to the class. Science content accuracy was highly correlated with the use of kit-based resources supported with professional development, a preference for teaching science, and grade level. There was no correlation between the accuracy of science content and some common measures of teacher content knowledge (i.e., number of college science courses, science grades, or scores on a general science content test). Our study concluded that when provided with high quality curricular materials and targeted professional development, elementary teachers learn needed science content and present it accurately to their students.

  1. Accuracy Assessment Points for Valley Forge National Historical Park Vegetation Mapping Project

    National Park Service, Department of the Interior — This shapefile includes the accuracy assessment points used to assess the association-level vegetation map of Valley Forge National Historic Park developed by the...

  2. Eyewitness memory of a supermarket robbery: a case study of accuracy and confidence after 3 months.

    Odinot, Geralda; Wolters, Gezinus; van Koppen, Peter J

    2009-12-01

    In this case study, 14 witnesses of an armed robbery were interviewed after 3 months. Security camera recordings were used to assess memory accuracy. Of all information that could be remembered about 84% was correct. Although accurately recalled information had a higher confidence level on average than inaccurately recalled information, the mean accuracy-confidence correlation was rather modest (0.38). These findings indicate that confidence is not a reliable predictor of accuracy. A higher level of self-reported, post-event thinking about the incident was associated with higher confidence levels, while a higher level of self-reported emotional impact was associated with greater accuracy. A potential source of (mis)information, a reconstruction of the robbery broadcasted on TV, did not alter the original memories of the witnesses. PMID:18719983

  3. Accuracy Assessment and Analysis for GPT2

    YAO Yibin

    2015-07-01

    Full Text Available GPT(global pressure and temperature is a global empirical model usually used to provide temperature and pressure for the determination of tropospheric delay, there are some weakness to GPT, these have been improved with a new empirical model named GPT2, which not only improves the accuracy of temperature and pressure, but also provides specific humidity, water vapor pressure, mapping function coefficients and other tropospheric parameters, and no accuracy analysis of GPT2 has been made until now. In this paper high-precision meteorological data from ECWMF and NOAA were used to test and analyze the accuracy of temperature, pressure and water vapor pressure expressed by GPT2, testing results show that the mean Bias of temperature is -0.59℃, average RMS is 3.82℃; absolute value of average Bias of pressure and water vapor pressure are less than 1 mb, GPT2 pressure has average RMS of 7 mb, and water vapor pressure no more than 3 mb, accuracy is different in different latitudes, all of them have obvious seasonality. In conclusion, GPT2 model has high accuracy and stability on global scale.

  4. Activity monitor accuracy in persons using canes

    Deborah Michael Wendland, PT, DPT, CPed

    2012-12-01

    Full Text Available The StepWatch activity monitor has not been validated on multiple indoor and outdoor surfaces in a population using ambulation aids. The aims of this technical report are to report on strategies to configure the StepWatch activity monitor on subjects using a cane and to report the accuracy of both leg-mounted and cane-mounted StepWatch devices on people ambulating over different surfaces while using a cane. Sixteen subjects aged 67 to 85 yr (mean 75.6 who regularly use a cane for ambulation participated. StepWatch calibration was performed by adjusting sensitivity and cadence. Following calibration optimization, accuracy was tested on both the leg-mounted and cane-mounted devices on different surfaces, including linoleum, sidewalk, grass, ramp, and stairs. The leg-mounted device had an accuracy of 93.4% across all surfaces, while the cane-mounted device had an aggregate accuracy of 84.7% across all surfaces. Accuracy of the StepWatch on the stairs was significantly less accurate (p < 0.001 when comparing surfaces using repeated measures analysis of variance. When monitoring community mobility, placement of a StepWatch on a person and his/her ambulation aid can accurately document both activity and device use.

  5. USE OF CHEMICAL INVENTORY ACCURACY MEASUREMENTS AS LEADING INDICATORS

    Kuntamukkula, M.

    2011-02-10

    Chemical safety and lifecycle management (CSLM) is a process that involves managing chemicals and chemical information from the moment someone begins to order a chemical and lasts through final disposition(1). Central to CSLM is tracking data associated with chemicals which, for the purposes of this paper, is termed the chemical inventory. Examples of data that could be tracked include chemical identity, location, quantity, date procured, container type, and physical state. The reason why so much data is tracked is that the chemical inventory supports many functions. These functions include emergency management, which depends upon the data to more effectively plan for, and respond to, chemical accidents; environmental management that uses inventory information to aid in the generation of various federally-mandated and other regulatory reports; and chemical management that uses the information to increase the efficiency and safety with which chemicals are stored and utilized. All of the benefits of having an inventory are predicated upon having an inventory that is reasonably accurate. Because of the importance of ensuring one's chemical inventory is accurate, many have become concerned about measuring inventory accuracy. But beyond providing a measure of confidence in information gleaned from the inventory, does the inventory accuracy measurement provide any additional function? The answer is 'Yes'. It provides valuable information that can be used as a leading indicator to gauge the health of a chemical management system. In this paper, we will discuss: what properties make leading indicators effective, how chemical inventories can be used as a leading indicator, how chemical inventory accuracy can be measured, what levels of accuracies should realistically be expected in a healthy system, and what a subpar inventory accuracy measurement portends.

  6. Accuracy of Trained Canines for Detecting Bed Bugs (Hemiptera: Cimicidae).

    Cooper, Richard; Wang, Changlu; Singh, Narinderpal

    2014-12-01

    Detection of low-level bed bug, Cimex lectularius L. (Hemiptera: Cimicidae), infestations is essential for early intervention, confirming eradication of infestations, and reducing the spread of bed bugs. Despite the importance of detection, few effective tools and methods exist for detecting low numbers of bed bugs. Scent dogs were developed as a tool for detecting bed bugs in recent years. However, there are no data demonstrating the reliability of trained canines under natural field conditions. We evaluated the accuracy of 11 canine detection teams in naturally infested apartments. All handlers believed their dogs could detect infestations at a very high rate (≥95%). In three separate experiments, the mean (min, max) detection rate was 44 (10-100)% and mean false-positive rate was 15 (0-57)%. The false-positive rate was positively correlated with the detection rate. The probability of a bed bug infestation being detected by trained canines was not associated with the level of bed bug infestations. Four canine detection teams evaluated on multiple days were inconsistent in their ability to detect bed bugs and exhibited significant variance in accuracy of detection between inspections on different days. There was no significant relationship between the team's experience or certification status of teams and the detection rates. These data suggest that more research is needed to understand factors affecting the accuracy of canine teams for bed bug detection in naturally infested apartments. PMID:26470083

  7. Efficient evaluation of accuracy of molecular quantum dynamics using dephasing representation

    Li, Baiqing; Mollica, Cesare; Vanicek, Jiri

    2009-01-01

    Ab initio methods for the electronic structure of molecules have reached a satisfactory accuracy for calculations of static properties but remain too expensive for quantum dynamics calculations. We propose an efficient semiclassical method for evaluating the accuracy of a lower level quantum dynamics, as compared to a higher level quantum dynamics, without having to perform any quantum dynamics. The method is based on the dephasing representation of quantum fidelity and its fe...

  8. Decreased interoceptive accuracy following social exclusion.

    Durlik, Caroline; Tsakiris, Manos

    2015-04-01

    The need for social affiliation is one of the most important and fundamental human needs. Unsurprisingly, humans display strong negative reactions to social exclusion. In the present study, we investigated the effect of social exclusion on interoceptive accuracy - accuracy in detecting signals arising inside the body - measured with a heartbeat perception task. We manipulated exclusion using Cyberball, a widely used paradigm of a virtual ball-tossing game, with half of the participants being included during the game and the other half of participants being ostracized during the game. Our results indicated that heartbeat perception accuracy decreased in the excluded, but not in the included, participants. We discuss these results in the context of social and physical pain overlap, as well as in relation to internally versus externally oriented attention. PMID:25701592

  9. Coordinate metrology accuracy of systems and measurements

    Sładek, Jerzy A

    2016-01-01

    This book focuses on effective methods for assessing the accuracy of both coordinate measuring systems and coordinate measurements. It mainly reports on original research work conducted by Sladek’s team at Cracow University of Technology’s Laboratory of Coordinate Metrology. The book describes the implementation of different methods, including artificial neural networks, the Matrix Method, the Monte Carlo method and the virtual CMM (Coordinate Measuring Machine), and demonstrates how these methods can be effectively used in practice to gauge the accuracy of coordinate measurements. Moreover, the book includes an introduction to the theory of measurement uncertainty and to key techniques for assessing measurement accuracy. All methods and tools are presented in detail, using suitable mathematical formulations and illustrated with numerous examples. The book fills an important gap in the literature, providing readers with an advanced text on a topic that has been rapidly developing in recent years. The book...

  10. Training in timing improves accuracy in golf.

    Libkuman, Terry M; Otani, Hajime; Steger, Neil

    2002-01-01

    In this experiment, the authors investigated the influence of training in timing on performance accuracy in golf. During pre- and posttesting, 40 participants hit golf balls with 4 different clubs in a golf course simulator. The dependent measure was the distance in feet that the ball ended from the target. Between the pre- and posttest, participants in the experimental condition received 10 hr of timing training with an instrument that was designed to train participants to tap their hands and feet in synchrony with target sounds. The participants in the control condition read literature about how to improve their golf swing. The results indicated that the participants in the experimental condition significantly improved their accuracy relative to the participants in the control condition, who did not show any improvement. We concluded that training in timing leads to improvement in accuracy, and that our results have implications for training in golf as well as other complex motor activities. PMID:12038497

  11. Location Update Accuracy in Human Tracking system using Zigbee modules

    Amutha, B

    2009-01-01

    A location and tracking system becomes very important to our future world of pervasive computing. An algorithm for accurate location information is being incorporated in the human walking model and in the blind human walking model. We want to implement an accurate location tracking mechanism using Zigbee along with GPS, we have incorporated Markov chain algorithm for establishing accuracy. Normal Human and blind human walking steps were actually taken in the known environment within our campus and the Markov chain algorithm was used for smoothening the stepwise variation in location updates. A comparison module is also implemented to show the difference between normal human and blind human walking step variations. This accuracy is used for designing a blind tracking device so that the device can be used by the blind for finding the path without obstacles. We present a system level approach to localizing and tracking Human and blind users on a basis of different sources of location information [GPS plus Zigbee...

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

    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.

  13. Systematic reviews of diagnostic test accuracy

    Leeflang, Mariska M G; Deeks, Jonathan J; Gatsonis, Constantine;

    2008-01-01

    More and more systematic reviews of diagnostic test accuracy studies are being published, but they can be methodologically challenging. In this paper, the authors present some of the recent developments in the methodology for conducting systematic reviews of diagnostic test accuracy studies....... Restrictive electronic search filters are discouraged, as is the use of summary quality scores. Methods for meta-analysis should take into account the paired nature of the estimates and their dependence on threshold. Authors of these reviews are advised to use the hierarchical summary receiver...

  14. Accuracy analysis of automatic distortion correction

    Kolecki Jakub

    2015-06-01

    Full Text Available The paper addresses the problem of the automatic distortion removal from images acquired with non-metric SLR camera equipped with prime lenses. From the photogrammetric point of view the following question arises: is the accuracy of distortion control data provided by the manufacturer for a certain lens model (not item sufficient in order to achieve demanded accuracy? In order to obtain the reliable answer to the aforementioned problem the two kinds of tests were carried out for three lens models.

  15. Final Technical Report: Increasing Prediction Accuracy.

    King, Bruce Hardison [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Hansen, Clifford [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Stein, Joshua [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

    2015-12-01

    PV performance models are used to quantify the value of PV plants in a given location. They combine the performance characteristics of the system, the measured or predicted irradiance and weather at a site, and the system configuration and design into a prediction of the amount of energy that will be produced by a PV system. These predictions must be as accurate as possible in order for finance charges to be minimized. Higher accuracy equals lower project risk. The Increasing Prediction Accuracy project at Sandia focuses on quantifying and reducing uncertainties in PV system performance models.

  16. ACCURACY ANALYSIS OF KINECT DEPTH DATA

    K. Khoshelham

    2012-09-01

    Full Text Available This paper presents an investigation of the geometric quality of depth data obtained by the Kinect sensor. Based on the mathematical model of depth measurement by the sensor a theoretical error analysis is presented, which provides an insight into the factors influencing the accuracy of the data. Experimental results show that the random error of depth measurement increases with increasing distance to the sensor, and ranges from a few millimetres up to about 4 cm at the maximum range of the sensor. The accuracy of the data is also found to be influenced by the low resolution of the depth measurements.

  17. Electron impact excitation out of the metastable levels of argon into the 3p54p J = 3 level

    We have measured the direct cross section for electron impact excitation out of the metastable 3p54s[3/2]20 level (1s5 in Paschen's notation) into the 3p54p[5/2]3 level (2p9) of argon from threshold to 800 eV. The direct cross section is 40 x 10-16 cm2 at 10 eV. (author)

  18. Speed-Accuracy Response Models: Scoring Rules Based on Response Time and Accuracy

    Maris, Gunter; van der Maas, Han

    2012-01-01

    Starting from an explicit scoring rule for time limit tasks incorporating both response time and accuracy, and a definite trade-off between speed and accuracy, a response model is derived. Since the scoring rule is interpreted as a sufficient statistic, the model belongs to the exponential family. The various marginal and conditional distributions…

  19. Accuracy of abdominal auscultation for bowel obstruction

    Breum, Birger Michael; Rud, Bo; Kirkegaard, Thomas; Nordentoft, Tyge

    2015-01-01

    AIM: To investigate the accuracy and inter-observer variation of bowel sound assessment in patients with clinically suspected bowel obstruction. METHODS: Bowel sounds were recorded in patients with suspected bowel obstruction using a Littmann(®) Electronic Stethoscope. The recordings were processed...

  20. The Diagnostic Accuracy of Digitized Mammography

    M. Guiti

    2008-06-01

    Full Text Available Background/Objective: Digitized mammography has several advantages over screen-film radiography in data storage and retrieval, making it a useful alternative to screen-film mammography in screening programs. The purpose of this study was to determine the diagnostic accuracy of digitized mammography in detecting breast cancer. "nPatients and Methods: 185 women (845 Images were digitized at 600 dpi. All images were reviewed by an expert radiologist. The mammograms were scored on a scale of breast imaging reporting and data system (BIRADS. The definite diagnosis was made either on the pathologic results of breast biopsy, or upon the follow-up of at least one year. The overall diagnostic accuracy of digitized mammography was calculated by the area under receiver operating characteristic curve."nResults: 242 sets of mammograms had no lesions. The total counts of masses, microcalcifications or both in one breast were 39 (11%, 42 (12%, and 25 (7%, respectively. There were 321 (92% benign and 27 (8% definite malignant lesions. The diagnostic accuracy of digitized images was 96.34% (95% CI: 94%-98%."nConclusion: The diagnostic accuracy of digitized mammography is comparably good or even better than the published results. The digitized mammography is a good substitute modality for screen-film mammography in screening programs.

  1. Observed Consultation: Confidence and Accuracy of Assessors

    Tweed, Mike; Ingham, Christopher

    2010-01-01

    Judgments made by the assessors observing consultations are widely used in the assessment of medical students. The aim of this research was to study judgment accuracy and confidence and the relationship between these. Assessors watched recordings of consultations, scoring the students on: a checklist of items; attributes of consultation; a…

  2. Bullet trajectory reconstruction - Methods, accuracy and precision.

    Mattijssen, Erwin J A T; Kerkhoff, Wim

    2016-05-01

    Based on the spatial relation between a primary and secondary bullet defect or on the shape and dimensions of the primary bullet defect, a bullet's trajectory prior to impact can be estimated for a shooting scene reconstruction. The accuracy and precision of the estimated trajectories will vary depending on variables such as, the applied method of reconstruction, the (true) angle of incidence, the properties of the target material and the properties of the bullet upon impact. This study focused on the accuracy and precision of estimated bullet trajectories when different variants of the probing method, ellipse method, and lead-in method are applied on bullet defects resulting from shots at various angles of incidence on drywall, MDF and sheet metal. The results show that in most situations the best performance (accuracy and precision) is seen when the probing method is applied. Only for the lowest angles of incidence the performance was better when either the ellipse or lead-in method was applied. The data provided in this paper can be used to select the appropriate method(s) for reconstruction and to correct for systematic errors (accuracy) and to provide a value of the precision, by means of a confidence interval of the specific measurement. PMID:27044032

  3. 47 CFR 65.306 - Calculation accuracy.

    2010-10-01

    ... 47 Telecommunication 3 2010-10-01 2010-10-01 false Calculation accuracy. 65.306 Section 65.306 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) COMMON CARRIER SERVICES (CONTINUED) INTERSTATE RATE OF RETURN PRESCRIPTION PROCEDURES AND METHODOLOGIES Exchange Carriers § 65.306 Calculation...

  4. Accuracy of sampling during mushroom cultivation

    Baars, J.J.P.; Hendrickx, P.M.; Sonnenberg, A.S.M.

    2015-01-01

    Experiments described in this report were performed to increase the accuracy of the analysis of the biological efficiency of Agaricus bisporus strains. Biological efficiency is a measure of the efficiency with which the mushroom strains use dry matter in the compost to produce mushrooms (expressed as dry matter produced).

  5. High Accuracy Transistor Compact Model Calibrations

    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.

  6. Accuracy in Robot Generated Image Data Sets

    Aanæs, Henrik; Dahl, Anders Bjorholm

    2015-01-01

    In this paper we present a practical innovation concerning how to achieve high accuracy of camera positioning, when using a 6 axis industrial robots to generate high quality data sets for computer vision. This innovation is based on the realization that to a very large extent the robots positioning...... in using robots for image data set generation....

  7. Accuracy of References in Five Entomology Journals.

    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…

  8. Direct Behavior Rating: Considerations for Rater Accuracy

    Harrison, Sayward E.; Riley-Tillman, T. Chris; Chafouleas, Sandra M.

    2014-01-01

    Direct behavior rating (DBR) offers users a flexible, feasible method for the collection of behavioral data. Previous research has supported the validity of using DBR to rate three target behaviors: academic engagement, disruptive behavior, and compliance. However, the effect of the base rate of behavior on rater accuracy has not been established.…

  9. Bayesian Methods for Medical Test Accuracy

    Lyle D. Broemeling

    2011-05-01

    Full Text Available Bayesian methods for medical test accuracy are presented, beginning with the basic measures for tests with binary scores: true positive fraction, false positive fraction, positive predictive values, and negative predictive value. The Bayesian approach is taken because of its efficient use of prior information, and the analysis is executed with a Bayesian software package WinBUGS®. The ROC (receiver operating characteristic curve gives the intrinsic accuracy of medical tests that have ordinal or continuous scores, and the Bayesian approach is illustrated with many examples from cancer and other diseases. Medical tests include X-ray, mammography, ultrasound, computed tomography, magnetic resonance imaging, nuclear medicine and tests based on biomarkers, such as blood glucose values for diabetes. The presentation continues with more specialized methods suitable for measuring the accuracies of clinical studies that have verification bias, and medical tests without a gold standard. Lastly, the review is concluded with Bayesian methods for measuring the accuracy of the combination of two or more tests.

  10. The impact of accuracy motivation on interpretation, comparison, and correction processes: accuracy x knowledge accessibility effects.

    Stapel, D A; Koomen, W; Zeelenberg, M

    1998-04-01

    Four studies provide evidence for the notion that there may be boundaries to the extent to which accuracy motivation may help perceivers to escape the influence of fortuitously activated information. Specifically, although accuracy motivations may eliminate assimilative accessibility effects, they are less likely to eliminate contrastive accessibility effects. It was found that the occurrence of different types of contrast effects (comparison and correction) was not significantly affected by participants' accuracy motivations. Furthermore, it was found that the mechanisms instigated by accuracy motivations differ from those ignited by correction instructions: Accuracy motivations attenuate assimilation effects because perceivers add target interpretations to the one suggested by primed information. Conversely, it was found that correction instructions yield contrast and prompt respondents to remove the priming event's influence from their reaction to the target. PMID:9569650

  11. High accuracy FIONA-AFM hybrid imaging

    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 ≥8 nm 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 (5-10 nm) information about the conformational properties of multi-protein complexes and the fluorescence can indicate spatial relationships of the proteins in the complexes. -- Research highlights: → Integration of fluorescent signals in AFM topography with high (<10 nm) accuracy. → Investigation of limitations and quantitative analysis of fluorescence-AFM image registration using quantum dots. → Fluorescence center tracking and display as localization probability distributions in AFM topography (FIONA-AFM). → Application of FIONA-AFM to a biological sample containing damaged DNA and the DNA repair proteins UvrA and UvrB conjugated to quantum dots.

  12. Diagnostic accuracy of MRCP in choledocholithiasis

    Purpose: To evaluate the accuracy of MRCP in diagnosing choledocholithiasis considering Endoscopic Retrograde Cholangiopancreatography (ERCP) as the gold standard. To compare the results achieved during the first two years of use (1999-2000) of Magnetic Resonance Cholangiopancreatography (MRCP) in patients with suspected choledocholithiasis with those achieved during the following two years (2001-2002) in order to establish the repeatability and objectivity of MRCP results. Materials and methods: One hundred and seventy consecutive patients underwent MRCP followed by ERCP within 72 h. In 22/170 (13%) patients ERCP was unsuccessful for different reasons. MRCP was performed using a 1.5 T magnet with both multi-slice HASTE sequences and thick-slice projection technique. Choledocholithiasis was diagnosed in the presence of signal void images in the dependent portion of the duct surrounded by hyperintense bile and detected at least in two projections. The MRCP results, read independently from the ERCP results, were compared in two different and subsequent periods. Results: ERCP confirmed choledocholithiasis in 87 patients. In these cases the results of MRCP were the following: 78 true positives, 53 true negatives, 7 false positives, and 9 false negatives. The sensitivity, specificity and accuracy were 90%, 88% and 89%, respectively. After the exclusion of stones with diameters smaller than 6 mm, the sensitivity, specificity and accuracy were 100%, 99% and 99%, respectively. MRCP accuracy was related to the size of the stones. There was no significant statistical difference between the results obtained in the first two-year period and those obtained in the second period. Conclusions: MRCP i sufficiently accurate to replace ERCP in patients with suspected choledocholithiasis. The results are related to the size of stones. The use of well-defined radiological signs allows good diagnostic accuracy independent of the learning curve

  13. Level sensing system

    García Fernández, Javier

    2011-01-01

    This report is to present the design and development of a liquid level sensing system based on SCADA system. It is a synthesis of the actions carried out for the construction of the liquid level measuring system. It is structured in five chapters that explain the steps for the realisation of the project. Knowing the content level of liquid in tanks is very important in industry, although accuracy demands vary according to business requirements. Therefore, it becomes extremely important to mon...

  14. Diagnostic Accuracy Comparison of Artificial Immune Algorithms for Primary Headaches

    Çelik, Ufuk; Yurtay, Nilüfer; Koç, Emine Rabia; Tepe, Nermin; Güllüoğlu, Halil; Ertaş, Mustafa

    2015-01-01

    The present study evaluated the diagnostic accuracy of immune system algorithms with the aim of classifying the primary types of headache that are not related to any organic etiology. They are divided into four types: migraine, tension, cluster, and other primary headaches. After we took this main objective into consideration, three different neurologists were required to fill in the medical records of 850 patients into our web-based expert system hosted on our project web site. In the evaluation process, Artificial Immune Systems (AIS) were used as the classification algorithms. The AIS are classification algorithms that are inspired by the biological immune system mechanism that involves significant and distinct capabilities. These algorithms simulate the specialties of the immune system such as discrimination, learning, and the memorizing process in order to be used for classification, optimization, or pattern recognition. According to the results, the accuracy level of the classifier used in this study reached a success continuum ranging from 95% to 99%, except for the inconvenient one that yielded 71% accuracy. PMID:26075014

  15. Diagnostic Accuracy Comparison of Artificial Immune Algorithms for Primary Headaches

    Ufuk Çelik

    2015-01-01

    Full Text Available The present study evaluated the diagnostic accuracy of immune system algorithms with the aim of classifying the primary types of headache that are not related to any organic etiology. They are divided into four types: migraine, tension, cluster, and other primary headaches. After we took this main objective into consideration, three different neurologists were required to fill in the medical records of 850 patients into our web-based expert system hosted on our project web site. In the evaluation process, Artificial Immune Systems (AIS were used as the classification algorithms. The AIS are classification algorithms that are inspired by the biological immune system mechanism that involves significant and distinct capabilities. These algorithms simulate the specialties of the immune system such as discrimination, learning, and the memorizing process in order to be used for classification, optimization, or pattern recognition. According to the results, the accuracy level of the classifier used in this study reached a success continuum ranging from 95% to 99%, except for the inconvenient one that yielded 71% accuracy.

  16. Global discriminative learning for higher-accuracy computational gene prediction.

    Axel Bernal

    2007-03-01

    Full Text Available Most ab initio gene predictors use a probabilistic sequence model, typically a hidden Markov model, to combine separately trained models of genomic signals and content. By combining separate models of relevant genomic features, such gene predictors can exploit small training sets and incomplete annotations, and can be trained fairly efficiently. However, that type of piecewise training does not optimize prediction accuracy and has difficulty in accounting for statistical dependencies among different parts of the gene model. With genomic information being created at an ever-increasing rate, it is worth investigating alternative approaches in which many different types of genomic evidence, with complex statistical dependencies, can be integrated by discriminative learning to maximize annotation accuracy. Among discriminative learning methods, large-margin classifiers have become prominent because of the success of support vector machines (SVM in many classification tasks. We describe CRAIG, a new program for ab initio gene prediction based on a conditional random field model with semi-Markov structure that is trained with an online large-margin algorithm related to multiclass SVMs. Our experiments on benchmark vertebrate datasets and on regions from the ENCODE project show significant improvements in prediction accuracy over published gene predictors that use intrinsic features only, particularly at the gene level and on genes with long introns.

  17. Radiometric and Geometric Accuracy Analysis of Rasat Pan Imagery

    Kocaman, S.; Yalcin, I.; Guler, M.

    2016-06-01

    RASAT is the second Turkish Earth Observation satellite which was launched in 2011. It operates with pushbroom principle and acquires panchromatic and MS images with 7.5 m and 15 m resolutions, respectively. The swath width of the sensor is 30 km. The main aim of this study is to analyse the radiometric and geometric quality of RASAT images. A systematic validation approach for the RASAT imagery and its products is being applied. RASAT image pair acquired over Kesan city in Edirne province of Turkey are used for the investigations. The raw RASAT data (L0) are processed by Turkish Space Agency (TUBITAK-UZAY) to produce higher level image products. The image products include radiometrically processed (L1), georeferenced (L2) and orthorectified (L3) data, as well as pansharpened images. The image quality assessments include visual inspections, noise, MTF and histogram analyses. The geometric accuracy assessment results are only preliminary and the assessment is performed using the raw images. The geometric accuracy potential is investigated using 3D ground control points extracted from road intersections, which were measured manually in stereo from aerial images with 20 cm resolution and accuracy. The initial results of the study, which were performed using one RASAT panchromatic image pair, are presented in this paper.

  18. The Crustal Thickness of Mars: Accuracy and Resolution

    Smith, David E.; Zuber, Maria T.

    2002-01-01

    Since the arrival of the Mars Global Surveyor (MGS) spacecraft at Mars and its entry into its mapping orbit in February 1999, the radio tracking and altimetry data from the mission have been part of the systematic mapping of the planet and used to develop very precise models of the gravity field and topography of Mars. Until the altimetry function of Mars Orbiter Laser Altimeter (MOLA) failed on June 30, 2001, the instrument had acquired close to 700 million measurements of the planet's radius, the majority of which have been used to develop a model of the topography with horizontal resolution of about 500 m and radial accuracy of better than 1 m. Concurrently, Doppler and range tracking of MGS by the Deep Space Network at X-band frequencies, with accuracies of about 50 microns/s and about 5 m respectively, have provided orbital knowledge of MGS to the few meter level and enabled the gravity perturbations of the spacecraft to be used to develop a improved gravity models of Mars. The recent models have horizontal resolutions of about 200 km, or degree 65, when expressed in spherical harmonics, and have accuracies of the order of a few mGals at the poles and about 10 mGals at the equator at the highest resolution.

  19. CERN Shop: Christmas Sale, 10 & 16.12.2004

    2004-01-01

    Looking for Christmas present ideas? Come to the Reception Shop Special Stand in Meyrin, Main Building, ground floor, on Friday 10 and/or on Thursday 16 December from 10:30 to 16:00. CERN 50th Anniversary sweat-shirt (grey in M, L, XL) 30.- CERN 50th Anniversary T-shirt, (S, M, L, XL) 20.- CERN 50th Anniversary silk tie (2 colours) 30.- Einstein silk tie (blue, grey) 45.- Silk scarf 40.- Swiss army knife with CERN logo 25.- Swiss Duo-Pack with CERN logo 30.- CERN 50th Anniversary watch (2 models) 40.- CERN pens (2 models) 5.- Small Open Day souvenirs (a few different items) 2.- CERN 50th Anniversary Book (English & French) 70.- "Prestigious Discoveries" at CERN (English/anglais) 32.- "Particle Odyssey" soft cover (English/anglais) 35.- If you miss this special occasion, the articles are also available at the Reception Shop in Building 33 from Monday to Saturday between 08:30 and 17:00 hrs. Education and Communica...

  20. Improvement in Rayleigh Scattering Measurement Accuracy

    Fagan, Amy F.; Clem, Michelle M.; Elam, Kristie A.

    2012-01-01

    Spectroscopic Rayleigh scattering is an established flow diagnostic that has the ability to provide simultaneous velocity, density, and temperature measurements. The Fabry-Perot interferometer or etalon is a commonly employed instrument for resolving the spectrum of molecular Rayleigh scattered light for the purpose of evaluating these flow properties. This paper investigates the use of an acousto-optic frequency shifting device to improve measurement accuracy in Rayleigh scattering experiments at the NASA Glenn Research Center. The frequency shifting device is used as a means of shifting the incident or reference laser frequency by 1100 MHz to avoid overlap of the Rayleigh and reference signal peaks in the interference pattern used to obtain the velocity, density, and temperature measurements, and also to calibrate the free spectral range of the Fabry-Perot etalon. The measurement accuracy improvement is evaluated by comparison of Rayleigh scattering measurements acquired with and without shifting of the reference signal frequency in a 10 mm diameter subsonic nozzle flow.

  1. Positional Accuracy Assessment of Googleearth in Riyadh

    Farah, Ashraf; Algarni, Dafer

    2014-06-01

    Google Earth is a virtual globe, map and geographical information program that is controlled by Google corporation. It maps the Earth by the superimposition of images obtained from satellite imagery, aerial photography and GIS 3D globe. With millions of users all around the globe, GoogleEarth® has become the ultimate source of spatial data and information for private and public decision-support systems besides many types and forms of social interactions. Many users mostly in developing countries are also using it for surveying applications, the matter that raises questions about the positional accuracy of the Google Earth program. This research presents a small-scale assessment study of the positional accuracy of GoogleEarth® Imagery in Riyadh; capital of Kingdom of Saudi Arabia (KSA). The results show that the RMSE of the GoogleEarth imagery is 2.18 m and 1.51 m for the horizontal and height coordinates respectively.

  2. Improving the accuracy of dynamic mass calculation

    Oleksandr F. Dashchenko

    2015-06-01

    Full Text Available With the acceleration of goods transporting, cargo accounting plays an important role in today's global and complex environment. Weight is the most reliable indicator of the materials control. Unlike many other variables that can be measured indirectly, the weight can be measured directly and accurately. Using strain-gauge transducers, weight value can be obtained within a few milliseconds; such values correspond to the momentary load, which acts on the sensor. Determination of the weight of moving transport is only possible by appropriate processing of the sensor signal. The aim of the research is to develop a methodology for weighing freight rolling stock, which increases the accuracy of the measurement of dynamic mass, in particular wagon that moves. Apart from time-series methods, preliminary filtration for improving the accuracy of calculation is used. The results of the simulation are presented.

  3. Evaluating measurement accuracy a practical approach

    Rabinovich, Semyon G

    2013-01-01

    The goal of Evaluating Measurement Accuracy: A Practical Approach is to present methods for estimating the accuracy of measurements performed in industry, trade, and scientific research. From developing the theory of indirect measurements to proposing new methods of reduction, transformation, and enumeration, this work encompasses the full range of measurement data processing. It includes many examples that illustrate the application of general theory to typical problems encountered in measurement practice. As a result, the book serves as an inclusive reference work for data processing of all types of measurements: single and multiple, combined and simultaneous, direct (both linear and nonlinear), and indirect (both dependent and independent). It is a working tool for experimental scientists and engineers of all disciplines who work with instrumentation. It is also a good resource for natural science and engineering students and for technicians performing measurements in industry. A key feature of the book is...

  4. The accuracy of portable peak flow meters.

    Miller, M. R.; Dickinson, S A; Hitchings, D J

    1992-01-01

    BACKGROUND: The variability of peak expiratory flow (PEF) is now commonly used in the diagnosis and management of asthma. It is essential for PEF meters to have a linear response in order to obtain an unbiased measurement of PEF variability. As the accuracy and linearity of portable PEF meters have not been rigorously tested in recent years this aspect of their performance has been investigated. METHODS: The response of several portable PEF meters was tested with absolute standards of flow ge...

  5. Limiting Accuracy of Inexact Saddle Point Solvers

    Rozložník, Miroslav; Jiránek, Pavel

    Dundee : University of Dundee, 2007 - (Griffith, D.; Watson , G.). s. 33-33 [Biennial Conference on Numerical Analysis /22./. 26.06.2007-29.06.2007, University of Dundee] R&D Projects: GA MŠk 1M0554; GA AV ČR 1ET400300415 Institutional research plan: CEZ:AV0Z10300504 Keywords : saddle point systems * iterative methods * rounding error analysis * limiting accuracy

  6. Accuracy of radiocarbon analyses at ANTARES

    Lawson, E.M.; Fink, D.; Hotchkis, M.; Hua, Q.; Jacobsen, G.; Smith, A.M.; Tuniz, C. [Australian Nuclear Science and Technology Organisation, Lucas Heights, NSW (Australia)

    1996-12-31

    Accuracy in Accelerator Mass Spectroscopy (AMS) measurements, as distinct from precision, requires the application of a number of corrections. Most of these are well known except in extreme circumstances and AMS can deliver radiocarbon results which are both precise and accurate in the 0.5 to 1.0% range. The corrections involved in obtaining final radiocarbon ages are discussed. 3 refs., 1 tab.

  7. FNAC ACCURACY IN DIAGNOSIS OF BREAST LESIONS

    Venugopal; Pratap; Nikshita

    2014-01-01

    BACKGROUND: Malignancy of breast imposes significant reduction in life span. The prognosis of breast cancer is primarily dependent on the extent of disease and also early diagnosis in important. FNAC is a widely accepted cytological technique in the early diagnosis of palpable breast lesions. There have been many studies of accuracy of FNAC, which has been shown to be high in many centres. AIMS: To compare cytological and histopathological diagnosis of breast lesions and to ...

  8. Marginal accuracy of temporary composite crowns.

    Tjan, A H; Tjan, A H; Grant, B E

    1987-10-01

    An in vitro study was conducted to quantitatively compare the marginal adaptation of temporary crowns made from Protemp material with those made from Scutan, Provisional, and Trim materials. A direct technique was used to make temporary restorations on prepared teeth with an impression as a matrix. Protem, Trim, and Provisional materials produced temporary crowns of comparable accuracy. Crowns made from Scutan material had open margins. PMID:2959770

  9. On the accuracy of language trees.

    Simone Pompei

    Full Text Available Historical linguistics aims at inferring the most likely language phylogenetic tree starting from information concerning the evolutionary relatedness of languages. The available information are typically lists of homologous (lexical, phonological, syntactic features or characters for many different languages: a set of parallel corpora whose compilation represents a paramount achievement in linguistics. From this perspective the reconstruction of language trees is an example of inverse problems: starting from present, incomplete and often noisy, information, one aims at inferring the most likely past evolutionary history. A fundamental issue in inverse problems is the evaluation of the inference made. A standard way of dealing with this question is to generate data with artificial models in order to have full access to the evolutionary process one is going to infer. This procedure presents an intrinsic limitation: when dealing with real data sets, one typically does not know which model of evolution is the most suitable for them. A possible way out is to compare algorithmic inference with expert classifications. This is the point of view we take here by conducting a thorough survey of the accuracy of reconstruction methods as compared with the Ethnologue expert classifications. We focus in particular on state-of-the-art distance-based methods for phylogeny reconstruction using worldwide linguistic databases. In order to assess the accuracy of the inferred trees we introduce and characterize two generalizations of standard definitions of distances between trees. Based on these scores we quantify the relative performances of the distance-based algorithms considered. Further we quantify how the completeness and the coverage of the available databases affect the accuracy of the reconstruction. Finally we draw some conclusions about where the accuracy of the reconstructions in historical linguistics stands and about the leading directions to improve

  10. Do Investors Learn About Analyst Accuracy?

    Chang, Charles; Daouk, Hazem; Wang, Albert

    2008-01-01

    We study the impact of analyst forecasts on prices to determine whether investors learn about analyst accuracy. Our test market is the crude oil futures market. Prices rise when analysts forecast a decrease (increase) in crude supplies. In the 15 minutes following supply realizations, prices rise (fall) when forecasts have been too high (low). In both the initial price action relative to forecasts and in the subsequent reaction relative to realized forecast errors, the price response is stron...

  11. Earnings Forecast Accuracy And Career Concerns

    Roger, Tristan

    2015-01-01

    Previous studies show that analysts' compensation is not linked to earnings forecast accuracy. We evidence however that analysts have incentives to issue accurate forecasts. We show that brokerage houses reward their best forecasters by assigning them to large, mature firms. Covering such firms increases the potential for future compensation as these firms generate a great deal of investment banking and trading activities. The coverage of such firms also increases analysts' exposure to large ...

  12. Credit report accuracy and access to credit

    Avery, Robert B.; Paul S. Calem; Glenn B. Canner

    2004-01-01

    Data that credit-reporting agencies maintain on consumers' credit-related experiences play a central role in U.S. credit markets. Analysts widely agree that the data enable these markets to function more efficiently and at lower cost than would otherwise be possible. Despite the great benefits of the current system, however, some analysts have raised concerns about the accuracy, timeliness, completeness, and consistency of consumer credit records and about the effects of data problems on the ...

  13. FIELD ACCURACY TEST OF RPAS PHOTOGRAMMETRY

    Barry, P; Coakley, R.

    2013-01-01

    Baseline Surveys Ltd is a company which specialises in the supply of accurate geospatial data, such as cadastral, topographic and engineering survey data to commercial and government bodies. Baseline Surveys Ltd invested in aerial drone photogrammetric technology and had a requirement to establish the spatial accuracy of the geographic data derived from our unmanned aerial vehicle (UAV) photogrammetry before marketing our new aerial mapping service. Having supplied the construction i...

  14. Algorithms for improving accuracy of spray simulation

    ZHANG HuiYa; ZHANG YuSheng; XIAO HeLin; XU Bo

    2007-01-01

    Fuel spray is the pivotal process of direct injection engine combustion. The accuracy of spray simulation determines the reliability of combustion calculation. However, the traditional techniques of spray simulation in KIVA and commercial CFD codes are very susceptible to grid resolution. As a consequence, predicted engine performance and emission can depend on the computational mesh. The two main causes of this problem are the droplet collision algorithm and coupling between gas and liquid phases. In order to improve the accuracy of spray simulation, the original KIVA code is modified using the cross mesh droplet collision (CMC) algorithm and gas phase velocity interpolation algorithm. In the constant volume apparatus and D.I. Diesel engine, the improvements of the modified KIVA code in spray simulation accuracy are checked from spray structure, predicted average drop size and spray tip penetration, respectively. The results show a dramatic decrease in grid dependency. With these changes, the distorted phenomenon of spray structure is vanished. The uncertainty in predicted average drop size is reduced from 30 to 5 μm in constant volume apparatus calculation, and the uncertainty is further reduced to 2 μm in an engine simulation. The predicted spray tip penetrations in engine simulation also have better consistency in medium and fine meshes.

  15. Accuracy of stereolithographic models of human anatomy

    A study was undertaken to determine the dimensional accuracy of anatomical replicas derived from X-ray 3D computed tomography (CT) images and produced using the rapid prototyping technique of stereolithography (SLA). A dry bone skull and geometric phantom were scanned, and replicas were produced. Distance measurements were obtained to compare the original objects and the resulting replicas. Repeated measurements between anatomical landmarks were used for comparison of the original skull and replica. Results for the geometric phantom demonstrate a mean difference of +0.47mm, representing an accuracy of 97.7-99.12%. Measurements of the skull produced a range of absolute differences (maximum +4.62mm, minimum +0.1mm, mean +0.85mm). These results support the use of SLA models of human anatomical structures in such areas as pre-operative planning of complex surgical procedures. For applications where higher accuracy is required, improvements can be expected by utilizing smaller pixel resolution in the CT images. Stereolithographic models can now be confidently employed as accurate, three-dimensional replicas of complex, anatomical structures. 14 refs., 2 tabs., 8 figs

  16. HEIGHT ACCURACY BASED ON DIFFERENT RTK GPS METHOD FOR ULTRALIGHT AIRCRAFT IMAGES

    K. N. Tahar

    2015-01-01

    Height accuracy is one of the important elements in surveying work especially for control point’s establishment which requires an accurate measurement. There are many methods can be used to acquire height value such as tacheometry, leveling and Global Positioning System (GPS). This study has investigated the effect on height accuracy based on different observations which are single based and network based GPS methods. The GPS network is acquired from the local network namely Iskandar...

  17. The influence of subjective factors on the evaluation of singing voice accuracy

    Larrouy, Pauline; Morsomme, Dominique

    2013-01-01

    A previous study highlighted the objectivity of music experts when rating the vocal accuracy of sung performances (Larrouy-Maestri, Lévêque, Schön, Giovanni, & Morsomme, 2013). However, in an ecological context, numerous factors can influence the judges’ assessment of a music performance. This preliminary study aims to examine the effect of the music level of the performers on the evaluation of singing voice accuracy and to explore subjective factors which could influence the assessment. T...

  18. Improving the Accuracy of Industrial Robots by offline Compensation of Joints Errors

    OLABI, Adel; Damak, Mohamed; BEAREE, Richard; Gibaru, Olivier; LELEU, Stéphane

    2012-01-01

    International audience The use of industrial robots in many fields of industry like prototyping, pre-machining and end milling is limited because of their poor accuracy. Robot joints are mainly responsible for this poor accuracy. The flexibility of robots joints and the kinematic errors in the transmission systems produce a significant error of position in the level of the end-effector. This paper presents these two types of joint errors. Identification methods are presented with experimen...

  19. Classification accuracy across multiple tests following item method directed forgetting.

    Goernert, Phillip N; Widner, Robert L; Otani, Hajime

    2007-09-01

    We investigated recall of line-drawing pictures paired at study with an instruction either to remember (TBR items) or to forget (TBF items). Across three 7-minute tests, net recall (items reported independent of accuracy in instructional designation) and correctly classified recall (recall conditional on correct instructional designation) showed directed forgetting. That is, for both measures, recall of TBR items always exceeded recall of TBF items. Net recall for both item types increased across tests at comparable levels showing hypermnesia. However, across tests, correct classification of both item types decreased at comparable levels. Collectively, hypermnesia as measured by net recall is possible for items from multiple sets, but at the cost of accurate source information. PMID:17676551

  20. Visual Inspection Displays Good Accuracy for Detecting Caries Lesions

    Twetman, Svante

    2015-01-01

    ARTICLE TITLE AND BIBLIOGRAPHIC INFORMATION: Visual inspection for caries detection: a systematic review and meta-analysis. Gimenez T, Piovesan C, Braga MM, Raggio DP, Deery C, Ricketts DN, Ekstrand DR, Mendes FM. J Dent Res 2015;94(7):895-904. REVIEWER: Svante Twetman, DDS, PhD, Odont Dr PURPOSE...... RECOMMENDATION GRADE: Grade A: Consistent, good-quality patient-oriented evidence......./QUESTION: To evaluate the overall accuracy of visual methods for detecting caries lesions. SOURCE OF FUNDING: Brazilian government (Process 2012/17888-1). TYPE OF STUDY/DESIGN: Systematic review with meta-analysis of data LEVEL OF EVIDENCE: Level 1: Good-quality, patient-oriented evidence STRENGTH OF...

  1. Character Reading Fluency, Word Segmentation Accuracy, and Reading Comprehension in L2 Chinese

    Shen, Helen H.; Jiang, Xin

    2013-01-01

    This study investigated the relationships between lower-level processing and general reading comprehension among adult L2 (second-language) beginning learners of Chinese, in both target and non-target language learning environments. Lower-level processing in Chinese reading includes the factors of character-naming accuracy, character-naming speed,…

  2. Thematic accuracy of the National Land Cover Database (NLCD) 2001 land cover for Alaska

    Selkowitz, D.J.; Stehman, S.V.

    2011-01-01

    The National Land Cover Database (NLCD) 2001 Alaska land cover classification is the first 30-m resolution land cover product available covering the entire state of Alaska. The accuracy assessment of the NLCD 2001 Alaska land cover classification employed a geographically stratified three-stage sampling design to select the reference sample of pixels. Reference land cover class labels were determined via fixed wing aircraft, as the high resolution imagery used for determining the reference land cover classification in the conterminous U.S. was not available for most of Alaska. Overall thematic accuracy for the Alaska NLCD was 76.2% (s.e. 2.8%) at Level II (12 classes evaluated) and 83.9% (s.e. 2.1%) at Level I (6 classes evaluated) when agreement was defined as a match between the map class and either the primary or alternate reference class label. When agreement was defined as a match between the map class and primary reference label only, overall accuracy was 59.4% at Level II and 69.3% at Level I. The majority of classification errors occurred at Level I of the classification hierarchy (i.e., misclassifications were generally to a different Level I class, not to a Level II class within the same Level I class). Classification accuracy was higher for more abundant land cover classes and for pixels located in the interior of homogeneous land cover patches. ?? 2011.

  3. Improving the accuracy of atomic emission determination of europium isotope ratio without reference samples

    A method has been developed of determining the isotopic composition of europium without standard reference samples. The estimation of the analysis accuracy has shown a statistically negligible systematic error. The confidence level of single determination (P0.95) is ± 0.3 at.% at 151Eu levels from 47.47 to 98.2 at.%

  4. Improvement of focus accuracy on processed wafer

    Higashibata, Satomi; Komine, Nobuhiro; Fukuhara, Kazuya; Koike, Takashi; Kato, Yoshimitsu; Hashimoto, Kohji

    2013-04-01

    As feature size shrinkage in semiconductor device progress, process fluctuation, especially focus strongly affects device performance. Because focus control is an ongoing challenge in optical lithography, various studies have sought for improving focus monitoring and control. Focus errors are due to wafers, exposure tools, reticles, QCs, and so on. Few studies are performed to minimize the measurement errors of auto focus (AF) sensors of exposure tool, especially when processed wafers are exposed. With current focus measurement techniques, the phase shift grating (PSG) focus monitor 1) has been already proposed and its basic principle is that the intensity of the diffraction light of the mask pattern is made asymmetric by arranging a π/2 phase shift area on a reticle. The resist pattern exposed at the defocus position is shifted on the wafer and shifted pattern can be easily measured using an overlay inspection tool. However, it is difficult to measure shifted pattern for the pattern on the processed wafer because of interruptions caused by other patterns in the underlayer. In this paper, we therefore propose "SEM-PSG" technique, where the shift of the PSG resist mark is measured by employing critical dimension-scanning electron microscope (CD-SEM) to measure the focus error on the processed wafer. First, we evaluate the accuracy of SEM-PSG technique. Second, by applying the SEM-PSG technique and feeding the results back to the exposure, we evaluate the focus accuracy on processed wafers. By applying SEM-PSG feedback, the focus accuracy on the processed wafer was improved from 40 to 29 nm in 3σ.

  5. [True color accuracy in digital forensic photography].

    Ramsthaler, Frank; Birngruber, Christoph G; Kröll, Ann-Katrin; Kettner, Mattias; Verhoff, Marcel A

    2016-01-01

    Forensic photographs not only need to be unaltered and authentic and capture context-relevant images, along with certain minimum requirements for image sharpness and information density, but color accuracy also plays an important role, for instance, in the assessment of injuries or taphonomic stages, or in the identification and evaluation of traces from photos. The perception of color not only varies subjectively from person to person, but as a discrete property of an image, color in digital photos is also to a considerable extent influenced by technical factors such as lighting, acquisition settings, camera, and output medium (print, monitor). For these reasons, consistent color accuracy has so far been limited in digital photography. Because images usually contain a wealth of color information, especially for complex or composite colors or shades of color, and the wavelength-dependent sensitivity to factors such as light and shadow may vary between cameras, the usefulness of issuing general recommendations for camera capture settings is limited. Our results indicate that true image colors can best and most realistically be captured with the SpyderCheckr technical calibration tool for digital cameras tested in this study. Apart from aspects such as the simplicity and quickness of the calibration procedure, a further advantage of the tool is that the results are independent of the camera used and can also be used for the color management of output devices such as monitors and printers. The SpyderCheckr color-code patches allow true colors to be captured more realistically than with a manual white balance tool or an automatic flash. We therefore recommend that the use of a color management tool should be considered for the acquisition of all images that demand high true color accuracy (in particular in the setting of injury documentation). PMID:27386623

  6. Accuracy of velocities from repeated GPS measurements

    Akarsu, V.; Sanli, D. U.; Arslan, E.

    2015-04-01

    Today repeated GPS measurements are still in use, because we cannot always employ GPS permanent stations due to a variety of limitations. One area of study that uses velocities/deformation rates from repeated GPS measurements is the monitoring of crustal motion. This paper discusses the quality of the velocities derived using repeated GPS measurements for the aim of monitoring crustal motion. From a global network of International GNSS Service (IGS) stations, we processed GPS measurements repeated monthly and annually spanning nearly 15 years and estimated GPS velocities for GPS baseline components latitude, longitude and ellipsoidal height. We used web-based GIPSY for the processing. Assuming true deformation rates can only be determined from the solutions of 24 h observation sessions, we evaluated the accuracy of the deformation rates from 8 and 12 h sessions. We used statistical hypothesis testing to assess the velocities derived from short observation sessions. In addition, as an alternative control method we checked the accuracy of GPS solutions from short observation sessions against those of 24 h sessions referring to statistical criteria that measure the accuracy of regression models. Results indicate that the velocities of the vertical component are completely affected when repeated GPS measurements are used. The results also reveal that only about 30% of the 8 h solutions and about 40% of 12 h solutions for the horizontal coordinates are acceptable for velocity estimation. The situation is much worse for the vertical component in which none of the solutions from campaign measurements are acceptable for obtaining reliable deformation rates.

  7. On the Accuracy of IGS Orbits

    Griffiths, J.; Ray, J.

    2007-12-01

    In order to explore the reliability of IGS internal orbit accuracy estimates, we have compared the geocentric satellite positions at the midnight epoch between consecutive days for the period since November 5, 2006, when the IGS changed its method of antenna calibration. For each pair of orbits, day "A" has been fitted to the extended CODE orbit model (three position and three velocity parameters plus nine nuisance solar radiation parameters), using the IGS05 Final orbits as psuedo-observations, and extrapolated to epoch 24:00 to compare with the 00:00 epoch from the IGS05 Final orbits of day "B". This yields a time series of orbit repeatability measures, analogous to the classical geodetic test for position determinations. To assess the error introduced by the fitting and extrapolation process, the same procedure has been applied to several days dropping the 23:45 epoch, fitting up to 23:30, extrapolating to 23:45, and comparing with reported positions for 23:45. The test differences range between 0 and 10 mm (mean = 3 mm) per geocentric component with 3D differences of 3 to 10 mm (mean = 6 mm). So, the effect of the orbit fitting-extrapolation process nearly always adds insignificant noise to the day- boundary orbit comparisons. If we compare our average 1D position differences to the official IGS accuracy codes (derived from the internal agreement among combined orbit solutions), root-sum-squared for each pair of days, the actual discontinuities are not well correlated with the expected performance values. If instead the IGS RMS values from the Final combination long-arc analyses (which also use the extended CODE model) are taken as the measure of IGS accuracy, the actual orbit discontinuties are much better represented. This is despite the fact that our day- boundary offsets apply to a single epoch each day and the long-arc analyses consider variations over a day (compared to the satellite dynamics determined over the full week). Our method is not well suited

  8. Computing High Accuracy Power Spectra with Pico

    Fendt, William A.; Wandelt, Benjamin D.

    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% ...

  9. Accuracy of the river discharge measurement

    Chung Yang, Han

    2013-04-01

    Discharge values recorded for water conservancy and hydrological analysis is a very important work. Flood control projects, watershed remediation and river environmental planning projects quite need the discharge measurement data. In Taiwan, we have 129 rivers, in accordance with the watershed situation, economic development and other factors, divided into 24 major rivers, 29 minor rivers and 79 ordinary rivers. If each river needs to measure and record these discharge values, it will be enormous work. In addition, the characteristics of Taiwan's rivers contain steep slope, flow rapidly and sediment concentration higher, so it really encounters some difficulties in high flow measurement. When the flood hazards come, to seek a solution for reducing the time, manpower and material resources in river discharge measurement is very important. In this study, the river discharge measurement accuracy is used to determine the tolerance percentage to reduce the number of vertical velocity measurements, thereby reducing the time, manpower and material resources in the river discharge measurement. The velocity data sources used in this study form Yang (1998). Yang (1998) used the Fiber-optic Laser Doppler Velocimetery (FLDV) to obtain different velocity data under different experimental conditions. In this study, we use these data to calculate the mean velocity of each vertical line by three different velocity profile formula (that is, the law of the wall, Chiu's theory, Hu's theory), and then multiplied by each sub-area to obtain the discharge measurement values and compared with the true values (obtained by the direct integration mode) to obtain the accuracy of discharge. The research results show that the discharge measurement values obtained by Chiu's theory are closer to the true value, while the maximum error is the law of the wall. The main reason is that the law of the wall can't describe the maximum velocity occurred in underwater. In addition, the results also show

  10. Accuracy of Ultrasonography in Diagnosing Acute Appendicitis

    Parisa Javidi Parsijani; Nima Pourhabibi Zarandi; Shahram Paydar; Hamidreza Abbasi; Shahram Bolandparvaz

    2013-01-01

    Objectives: To evaluate the accuracy of sonography in diagnosing acute appendicitis in patients with Alvarado score 4–7.Methods: This is a retrospective cross-sectional study being performed in Namazee hospital affiliated with Shiraz University of Medical sciences during a one year period from 9/2007 to 9/2008. We evaluated all patients with Alvarado score 4-7 and divided them in two groups: those with Ultrasound study prior to surgery and those without any imaging modalities for diagnosis of...

  11. Proper motion accuracy of WFPDF stars

    Chapanov, Y.; Vondrák, Jan; Ron, Cyril; Štefka, Vojtěch

    Beograd : Astronomical Society "Rudjer Boškovič", 2012 - (Tsvetkov, M.; Dimitrijevič, M.; Tsvetkova, K.; Kounchev, O.; Mijajlovič, Ž.), s. 169-176 ISBN 9788689035018. [Bulgarian-Serbian Astronomical Conference /7./. Chepelare (BG), 01.06.2010-04.06.2010] R&D Projects: GA MŠk(CZ) LC506 Institutional research plan: CEZ:AV0Z10030501 Keywords : proper motions * accuracy Subject RIV: BN - Astronomy, Celestial Mechanics, Astrophysics http://wfpdb.org/ftp/7_BSAC/pdfs/c06.pdf

  12. High precision numerical accuracy in physics research

    Concerns arise that the current standard of double-precision floating-point may no longer be sufficient for today's large-scale numerical simulations. One approach to solve this problem will be to switch to a wider floating-point format: the upcoming quadruple-precision standard is introduced and compared to currently available software-based approaches. Another complimentary approach is to use mathematical and algorithmic techniques to improve the accuracy of large floating-point programs and the confidence in the quality of the result

  13. Improving the accuracy of livestock distribution estimates through spatial interpolation

    Ward Bryssinckx

    2012-11-01

    Full Text Available Animal distribution maps serve many purposes such as estimating transmission risk of zoonotic pathogens to both animals and humans. The reliability and usability of such maps is highly dependent on the quality of the input data. However, decisions on how to perform livestock surveys are often based on previous work without considering possible consequences. A better understanding of the impact of using different sample designs and processing steps on the accuracy of livestock distribution estimates was acquired through iterative experiments using detailed survey. The importance of sample size, sample design and aggregation is demonstrated and spatial interpolation is presented as a potential way to improve cattle number estimates. As expected, results show that an increasing sample size increased the precision of cattle number estimates but these improvements were mainly seen when the initial sample size was relatively low (e.g. a median relative error decrease of 0.04% per sampled parish for sample sizes below 500 parishes. For higher sample sizes, the added value of further increasing the number of samples declined rapidly (e.g. a median relative error decrease of 0.01% per sampled parish for sample sizes above 500 parishes. When a two-stage stratified sample design was applied to yield more evenly distributed samples, accuracy levels were higher for low sample densities and stabilised at lower sample sizes compared to one-stage stratified sampling. Aggregating the resulting cattle number estimates yielded significantly more accurate results because of averaging under- and over-estimates (e.g. when aggregating cattle number estimates from subcounty to district level, P <0.009 based on a sample of 2,077 parishes using one-stage stratified samples. During aggregation, area-weighted mean values were assigned to higher administrative unit levels. However, when this step is preceded by a spatial interpolation to fill in missing values in non

  14. A Cascaded Fingerprint Quality Assessment Scheme for Improved System Accuracy

    Zia Saquib

    2011-03-01

    Full Text Available Poor-quality images mostly result in spurious or missing features, which further degrade the overall performance of fingerprint recognition systems. This paper proposes a reconfigurable scheme of quality checks at two different levels: i at raw image level and ii at feature level. At first level, ellipse properties are calculated through analysis of statistical attributes of the captured raw image. At second level, the singularity points (core and delta are identified and extracted (if any. These information, as quality measures, are used in a cascaded manner to block/pass the image. This model is tested on both publicly available (Cross Match Verifier 300 sensor as well as proprietary (Lumidigm Venus V100 OEM Module sensor fingerprint databases scanned at 500 dpi. The experimental results show that this cascaded arrangement of quality barricades could correctly block poor quality images and hence elevated the overall system accuracy: with quality checks, both FNMR and FMR significantly dropped to 9.52% and 0.26% respectively for Cross Match Dataset and 2.17% and 2.16% respectively for Lumidigm Dataset.

  15. Improvements on the accuracy of beam bugs

    At LLNL resistive wall monitors are used to measure the current and position used on ETA-II show a droop in signal due to a fast redistribution time constant of the signals. This paper presents the analysis and experimental test of the beam bugs used for beam current and position measurements in and after the fast kicker. It concludes with an outline of present and future changes that can be made to improve the accuracy of these beam bugs. of intense electron beams in electron induction linacs and beam transport lines. These, known locally as ''beam bugs'', have been used throughout linear induction accelerators as essential diagnostics of beam current and location. Recently, the development of a fast beam kicker has required improvement in the accuracy of measuring the position of beams. By picking off signals at more than the usual four positions around the monitor, beam position measurement error can be greatly reduced. A second significant source of error is the mechanical variation of the resistor around the bug

  16. Improvements on the accuracy of beam bugs

    At LLNL resistive wall monitors are used to measure the current and position used on ETA-II show a droop in signal due to a fast redistribution time constant of the signals. This paper presents the analysis and experimental test of the beam bugs used for beam current and position measurements in and after the fast kicker. It concludes with an outline of present and future changes that can be made to improve the accuracy of these beam bugs. of intense electron beams in electron induction linacs and beam transport lines. These, known locally as beam bugs, have been used throughout linear induction accelerators as essential diagnostics of beam current and location. Recently, the development of a fast beam kicker has required improvement in the accuracy of measuring the position of beams. By picking off signals at more than the usual four positions around the monitor, beam position measurement error can be greatly reduced. A second significant source of error is the mechanical variation of the resistor around the bug

  17. Fast and High Accuracy Wire Scanner

    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. The Indicators’ Inadequacy and the Predictions’ Accuracy

    Constantin Mitruț

    2013-08-01

    Full Text Available In this article, we proposed the introduction in literature of a new source of uncertainty in modeling and forecasting: the indicators’ inadequacy. Even if it was observed, a specific nominalization in the context of forecasting procedure has not been done yet. The inadequacy of indicators as a supplementary source of uncertainty generates a lower degree of accuracy in forecasting. This assumption was proved using empirical data related to the prediction of unemployment rate in Romania on the horizon 2011-2013. Four strategies of modeling and predicting the unemployment rate were proposed, observing two types of indicators’ inadequacy: the use of transformed variables in order to get stationary data set (the difference between the unemployment rates registered in two successive periods was used instead of the unemployment rate and the utilization of macro-regional unemployment rates whose predictions are aggregated in order to forecast the overall unemployment rate in Romania. The results put in evidence that the predictions of the total unemployment rate using moving average models of order 2 are the most accurate, being followed by the forecasts based on the predictions of active civil population and number of unemployed people. The strategies based on the aggregation of the predictions for the four macro-regional unemployment rates imply a higher inadequacy and consequently a lower degree of forecasts’ accuracy.

  19. Dust trajectory sensor: Accuracy and data analysis

    The Dust Trajectory Sensor (DTS) instrument is developed for the measurement of the velocity vector of cosmic dust particles. The trajectory information is imperative in determining the particles' origin and distinguishing dust particles from different sources. The velocity vector also reveals information on the history of interaction between the charged dust particle and the magnetospheric or interplanetary space environment. The DTS operational principle is based on measuring the induced charge from the dust on an array of wire electrodes. In recent work, the DTS geometry has been optimized [S. Auer, E. Gruen, S. Kempf, R. Srama, A. Srowig, Z. Sternovsky, and V Tschernjawski, Rev. Sci. Instrum. 79, 084501 (2008)] and a method of triggering was developed [S. Auer, G. Lawrence, E. Gruen, H. Henkel, S. Kempf, R. Srama, and Z. Sternovsky, Nucl. Instrum. Methods Phys. Res. A 622, 74 (2010)]. This article presents the method of analyzing the DTS data and results from a parametric study on the accuracy of the measurements. A laboratory version of the DTS has been constructed and tested with particles in the velocity range of 2-5 km/s using the Heidelberg dust accelerator facility. Both the numerical study and the analyzed experimental data show that the accuracy of the DTS instrument is better than about 1% in velocity and 1 deg. in direction.

  20. Dimensional accuracy of 3D printed vertebra

    Ogden, Kent; Ordway, Nathaniel; Diallo, Dalanda; Tillapaugh-Fay, Gwen; Aslan, Can

    2014-03-01

    3D printer applications in the biomedical sciences and medical imaging are expanding and will have an increasing impact on the practice of medicine. Orthopedic and reconstructive surgery has been an obvious area for development of 3D printer applications as the segmentation of bony anatomy to generate printable models is relatively straightforward. There are important issues that should be addressed when using 3D printed models for applications that may affect patient care; in particular the dimensional accuracy of the printed parts needs to be high to avoid poor decisions being made prior to surgery or therapeutic procedures. In this work, the dimensional accuracy of 3D printed vertebral bodies derived from CT data for a cadaver spine is compared with direct measurements on the ex-vivo vertebra and with measurements made on the 3D rendered vertebra using commercial 3D image processing software. The vertebra was printed on a consumer grade 3D printer using an additive print process using PLA (polylactic acid) filament. Measurements were made for 15 different anatomic features of the vertebral body, including vertebral body height, endplate width and depth, pedicle height and width, and spinal canal width and depth, among others. It is shown that for the segmentation and printing process used, the results of measurements made on the 3D printed vertebral body are substantially the same as those produced by direct measurement on the vertebra and measurements made on the 3D rendered vertebra.

  1. Dust trajectory sensor: accuracy and data analysis.

    Xie, J; Sternovsky, Z; Grün, E; Auer, S; Duncan, N; Drake, K; Le, H; Horanyi, M; Srama, R

    2011-10-01

    The Dust Trajectory Sensor (DTS) instrument is developed for the measurement of the velocity vector of cosmic dust particles. The trajectory information is imperative in determining the particles' origin and distinguishing dust particles from different sources. The velocity vector also reveals information on the history of interaction between the charged dust particle and the magnetospheric or interplanetary space environment. The DTS operational principle is based on measuring the induced charge from the dust on an array of wire electrodes. In recent work, the DTS geometry has been optimized [S. Auer, E. Grün, S. Kempf, R. Srama, A. Srowig, Z. Sternovsky, and V Tschernjawski, Rev. Sci. Instrum. 79, 084501 (2008)] and a method of triggering was developed [S. Auer, G. Lawrence, E. Grün, H. Henkel, S. Kempf, R. Srama, and Z. Sternovsky, Nucl. Instrum. Methods Phys. Res. A 622, 74 (2010)]. This article presents the method of analyzing the DTS data and results from a parametric study on the accuracy of the measurements. A laboratory version of the DTS has been constructed and tested with particles in the velocity range of 2-5 km/s using the Heidelberg dust accelerator facility. Both the numerical study and the analyzed experimental data show that the accuracy of the DTS instrument is better than about 1% in velocity and 1° in direction. PMID:22047326

  2. Accuracy of MR in growth plate measurement

    Shiguetomi-Medina, Juan Manuel [Aarhus University, Orthopaedic Research Laboratory, Aarhus University Hospital NBG, Aarhus C (Denmark); Rahbek, Ole [Aarhus University Hospital NBG, Department of Children' s Orthopaedics, Aarhus C (Denmark); Ringgaard, Steffen; Kristiansen, Maja Sofie; Stoedkilde-Joergensen, Hans [Aarhus University Hospital, Skejby, The MR Research Center, Aarhus N (Denmark); Moeller-Madsen, Bjarne [Aarhus University, Orthopaedic Research Laboratory, Aarhus University Hospital NBG, Aarhus C (Denmark); Aarhus University Hospital NBG, Department of Children' s Orthopaedics, Aarhus C (Denmark)

    2014-09-15

    To analyze the accuracy of growth-plate thickness measurements detected on 1.5-T and 7-T MR images using histology sections as a standard of reference. Four defrosted pig tibiae were 1.5-T MR scanned and one fresh tibia was 7-T MR scanned. The height of the growth plate was measured and compared to histology. Histology measurements showed a mean growth plate thickness of 467 μm (SD = 82.2). The mean growth plate thickness measured in the 7-T MR images was 465 μm (SD = 62.2) and 1,325 μm (SD = 183.5) on 1.5-T MR measurements. We found a better correspondence between the growth plate thickness measured on the 7-T MR and histology samples compared to 1.5 T. The growth plate can be identified and measured with high accuracy using 7-T MR. 1.5-T MR can only describe some morphological characteristics. (orig.)

  3. Accuracy assessment of landslide prediction models

    The increasing population and expansion of settlements over hilly areas has greatly increased the impact of natural disasters such as landslide. Therefore, it is important to developed models which could accurately predict landslide hazard zones. Over the years, various techniques and models have been developed to predict landslide hazard zones. The aim of this paper is to access the accuracy of landslide prediction models developed by the authors. The methodology involved the selection of study area, data acquisition, data processing and model development and also data analysis. The development of these models are based on nine different landslide inducing parameters i.e. slope, land use, lithology, soil properties, geomorphology, flow accumulation, aspect, proximity to river and proximity to road. Rank sum, rating, pairwise comparison and AHP techniques are used to determine the weights for each of the parameters used. Four (4) different models which consider different parameter combinations are developed by the authors. Results obtained are compared to landslide history and accuracies for Model 1, Model 2, Model 3 and Model 4 are 66.7, 66.7%, 60% and 22.9% respectively. From the results, rank sum, rating and pairwise comparison can be useful techniques to predict landslide hazard zones

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

    Xu, X. Q.

    2015-09-01

    respectively, which are used to improve/re-evaluate the AR model. Comparing to the single AR model, the AR+Kalman method performs better in the prediction of UT1-UTC and ΔLOD, and the improvement in the prediction of the polar motion is significant. (3) Following the successful Earth Orientation Parameter Prediction Comparison Campaign (EOP PCC), the Earth Orientation Parameter Combination of Prediction Pilot Project (EOPC PPP) was sponsored in 2010. As one of the participants from China, we update and submit the short- and medium-term (1 to 90 days) EOP predictions every day. From the current comparative statistics, our prediction accuracy is on the medium international level. We will carry out more innovative researches to improve the EOP forecast accuracy and enhance our level in EOP forecast.

  5. Diagnostic accuracy of slit skin smears in leprosy

    To determine the diagnostic accuracy of slit skin smears in clinically suspected patients of leprosy using histopathology as gold standard. Study Design: Validation study Place and Duration of Study: Study was carried out at Rawalpindi Leprosy Hospital, Dermatology Department Military Hospital (MH) and Armed Forces Institute of Pathology (AFIP), Rawalpindi from 18th August 2012 to 18 Feb 2013. Methods: Appropriate technical and ethical approval for the study and patient consent were obtained. All suspected patients of leprosy of any age and either gender having typical hypo-aesthetic or anesthetic, erythematous or hypo-pigmented scaly skin lesions on any part of body were included in this study. All patients who have already received treatment for leprosy, patients with pure neural leprosy, patient not giving their consent for skin biopsy and patients with lepra reactions were excluded from this study. Forty eight patients fulfilling the inclusion criteria were included in the study. Sample size had been calculated by using WHO sample size calculator taking confidence level 95%, absolute precision required 14% and anticipated population proportion 40%. Non-probability consecutive sampling technique was used to collect sample. Results: The results of the study revealed that out of 48 clinically suspected patients of leprosy skin biopsy confirmed the diagnosis in 34 patients (70.8%) and the slit skin smear had diagnostic accuracy of 68.75% with sensitivity 55.8% and specificity and positive predictive value of 100%. Conclusion: Study suggested that although slit skin smears are rapid and inexpensive method of diagnosis but their diagnostic accuracy is low. (author)

  6. Accuracy of handheld blood glucose meters at high altitude.

    Pieter de Mol

    Full Text Available 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 studies reported bias in blood glucose measurements using different BGMs at high altitude. We hypothesized that glucose-oxidase based BGMs are more influenced by the lower atmospheric oxygen pressure at altitude than glucose dehydrogenase based BGMs. METHODOLOGY/PRINCIPAL FINDINGS: Glucose measurements at simulated altitude of nine BGMs (six glucose dehydrogenase and three glucose oxidase BGMs were compared to glucose measurement on a similar BGM at sea level and to a laboratory glucose reference method. Venous blood samples of four different glucose levels were used. Moreover, two glucose oxidase and two glucose dehydrogenase based BGMs were evaluated at different altitudes on Mount Kilimanjaro. Accuracy criteria were set at a bias 6.5 mmol/L and <1 mmol/L from reference glucose (when <6.5 mmol/L. No significant difference was observed between measurements at simulated altitude and sea level for either glucose oxidase based BGMs or glucose dehydrogenase based BGMs as a group phenomenon. Two GDH based BGMs did not meet set performance criteria. Most BGMs are generally overestimating true glucose concentration at high altitude. CONCLUSION: At simulated high altitude all tested BGMs, including glucose oxidase based BGMs, did not show influence of low atmospheric oxygen pressure. All BGMs, except for two GDH based BGMs, performed within predefined criteria. At true high altitude one GDH based BGM had best precision and accuracy.

  7. ASSESSMENT OF THE THEMATIC ACCURACY OF LAND COVER MAPS

    Høhle, Joachim

    user’s and producer’s accuracy, and kappa coefficient. In addition, confidence intervals were computed for several accuracy measures. The achieved accuracies and confidence intervals are thoroughly analysed and recommendations are derived from the gained experiences. Reliable reference values are...... methods perform equally for five classes. Trees are classified with a much better accuracy and a smaller confidence interval by means of the decision tree method. Buildings are classified by both methods with an accuracy of 99% (95% CI: 95%-100%) using independent 3D checkpoints. The average width of the...... confidence interval of six classes was 14% of the user’s accuracy....

  8. Matter power spectrum and the challenge of percent accuracy

    Schneider, Aurel; Potter, Doug; Stadel, Joachim; Onions, Julian; Reed, Darren S; Smith, Robert E; Springel, Volker; Pearce, Frazer R

    2015-01-01

    Future galaxy surveys require one percent precision in the theoretical knowledge of the power spectrum over a large range including very nonlinear scales. While this level of accuracy is easily obtained in the linear regime with perturbation theory, it represents a serious challenge for small scales where numerical simulations are required. In this paper we quantify the accuracy of present-day $N$-body methods, identifying main potential error sources from the set-up of initial conditions to the measurement of the final power spectrum. We directly compare three widely used $N$-body codes, Ramses, Pkdgrav3, and Gadget3 which represent three main discretisation techniques: the particle-mesh method, the tree method, and a hybrid combination of the two. For standard run parameters, the codes agree to within one percent at $k\\leq1$ $h\\,\\rm Mpc^{-1}$ and to within three percent at $k\\leq10$ $h\\,\\rm Mpc^{-1}$. In a second step, we quantify potential errors due to initial conditions, box size, and resolution using an...

  9. Evaluation of DEM generation accuracy from UAS imagery

    Santise, M.; Fornari, M.; Forlani, G.; Roncella, R.

    2014-06-01

    The growing use of UAS platform for aerial photogrammetry comes with a new family of Computer Vision highly automated processing software expressly built to manage the peculiar characteristics of these blocks of images. It is of interest to photogrammetrist and professionals, therefore, to find out whether the image orientation and DSM generation methods implemented in such software are reliable and the DSMs and orthophotos are accurate. On a more general basis, it is interesting to figure out whether it is still worth applying the standard rules of aerial photogrammetry to the case of drones, achieving the same inner strength and the same accuracies as well. With such goals in mind, a test area has been set up at the University Campus in Parma. A large number of ground points has been measured on natural as well as signalized points, to provide a comprehensive test field, to check the accuracy performance of different UAS systems. In the test area, points both at ground-level and features on the buildings roofs were measured, in order to obtain a distributed support also altimetrically. Control points were set on different types of surfaces (buildings, asphalt, target, fields of grass and bumps); break lines, were also employed. The paper presents the results of a comparison between two different surveys for DEM (Digital Elevation Model) generation, performed at 70 m and 140 m flying height, using a Falcon 8 UAS.

  10. [Accuracy of MiniWright peak expiratory flow meters

    Camargos, P A; Ruchkys, V C; Dias, R M; Sakurai, E

    2000-01-01

    OBJECTIVE: To evaluate the accuracy of the Mini-Wright (Clement Clarke International Ltd.) peak-flow meters. METHODS: Twenty of those meters were checked by use of electronic calibration syringe (Jones Flow-Volume Calibrator(R)). Nine of them had an old scale, with values displayed equidistantly, and eleven had a new mechanical scale with non-equidistant values. Each device was connected in series to the calibration syringe to perform eight hand-driven volume injections, with flows ranging from 100 to 700 l/min. Absolute and relative differences between meters and syringe were calculated, the syringe values taken as standard. The accuracy of the twenty Mini-Wright devices was validated by the American Thoracic Society criteria (-/+ 10% or -/+ 20 l/min), and/or European Respiratory Society criteria (-/+ 5% or -/+ 5 l/ min). RESULTS: New scale instruments were more accurate than old scale meters (p < 0.001), by both ATS and ERS criteria. Every meter was rechecked after 600 measurements. Both the old, and the new scale instruments maintained the same level of performance after this evaluation. CONCLUSIONS: Results suggest that new scale meters were accurate and can be safely used in clinical practice. The authors strongly recommend that they are rechecked regularly to ensure that they are within the ATS and ERS variation limits. PMID:14647633

  11. Accuracy Assessment of a Uav-Based Landslide Monitoring System

    Peppa, M. V.; Mills, J. P.; Moore, P.; Miller, P. E.; Chambers, J. E.

    2016-06-01

    Landslides are hazardous events with often disastrous consequences. Monitoring landslides with observations of high spatio-temporal resolution can help mitigate such hazards. Mini unmanned aerial vehicles (UAVs) complemented by structure-from-motion (SfM) photogrammetry and modern per-pixel image matching algorithms can deliver a time-series of landslide elevation models in an automated and inexpensive way. This research investigates the potential of a mini UAV, equipped with a Panasonic Lumix DMC-LX5 compact camera, to provide surface deformations at acceptable levels of accuracy for landslide assessment. The study adopts a self-calibrating bundle adjustment-SfM pipeline using ground control points (GCPs). It evaluates misalignment biases and unresolved systematic errors that are transferred through the SfM process into the derived elevation models. To cross-validate the research outputs, results are compared to benchmark observations obtained by standard surveying techniques. The data is collected with 6 cm ground sample distance (GSD) and is shown to achieve planimetric and vertical accuracy of a few centimetres at independent check points (ICPs). The co-registration error of the generated elevation models is also examined in areas of stable terrain. Through this error assessment, the study estimates that the vertical sensitivity to real terrain change of the tested landslide is equal to 9 cm.

  12. Improving the Accuracy of Cosmic Magnification Statistics

    Ménard, B; Yoshida, M B N; Menard, Brice; Hamana, Takashi; Yoshida, Matthias Bartelmann & Naoki

    2003-01-01

    The systematic magnification of background sources by the weak gravitational-lensing effects of foreground matter, also called cosmic magnification, is becoming an efficient tool both for measuring cosmological parameters and for exploring the distribution of galaxies relative to the dark matter. We extend here the formalism of magnification statistics by estimating the contribution of second-order terms in the Taylor expansion of the magnification and show that the effect of these terms was previously underestimated. We test our analytical predictions against numerical simulations and demonstrate that including second-order terms allows the accuracy of magnification-related statistics to be substantially improved. We also show, however, that both numerical and analytical estimates can provide only lower bounds to real correlation functions, even in the weak lensing regime. We propose to use count-in-cells estimators rather than correlation functions for measuring cosmic magnification since they can more easi...

  13. High accuracy 3-D laser radar

    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...

  14. Comparative diagnostic accuracy in virtual dermatopathology

    Mooney, E.; Hood, A.F.; Lampros, J.;

    2011-01-01

    Background: Virtual microscopy can be used to teach histology and pathology and for in-training and certification examinations. A few online consultation websites already utilize virtual microscopy, thereby expanding the role of telemedicine in dermatopathology. There are, however, relatively few...... studies comparing the diagnostic accuracy and acceptability of virtual slides compared to traditional glass slides. Methods: Ten Nordic dermatopathologists and pathologists were given a randomized combination of 20 virtual and glass slides and asked to identify the diagnoses. They were then asked to give...... their impressions about the virtual images. Descriptive data analysis and comparison of groups using Fisher's exact test were performed. Objective: To compare the diagnostic ability of dermatopathologists and pathologists in two image formats: the traditional (glass) microscopic slides, and whole mount...

  15. On the accuracy of the Debye shielding

    Martínez-Fuentes, M A

    2012-01-01

    The expression for the Debye shielding in plasma physics is usually derived under the assumptions that the plasma particles are weakly coupled, so their kinetic energy is much larger than the potential energy between them, and that the velocity distributions of the plasma species are Maxwellian. The first assumption also establishes that the plasma parameter ND, the number of particles within a sphere with a Debye radius should be greater than 1, and determines the difference between weakly and strongly coupled plasmas. Under such assumptions, Poisson's equation can be linearised, and a simple analytic expression obtained for the electrostatic potential. However, textbooks rarely discuss the accuracy of this approximation. In this work we compare the linearised solution with the exact one, obtained numerically, and show that the linearisation, which underestimates the exact solution, is reasonably good even for ND ~ 40. We give quantitative criteria to set the limit of the approximation when the number of par...

  16. Accuracy of calculation of neutron detection efficiency

    The problems of the accuracy for the scintillator spectrometer calculation of neutron recording efficiency value are discussed. The calculation is performed by the method of direct simulation of neutron interaction with the scintillator substance. The preliminary calculations show that a contribution to efficiency of neutron recording in the range of energies of 10 through 50 MeV due to interaction of neutrons with carbon is mostly determined by reactions 12(in n' 2α)4He and 12(n, n' p)11B. The effciency calculation results are given for the cylindrical crystal of stilbene. Measurements of the neutron recording efficiency in the range of energies from 10 MeV indicate a good agreement between the calculation and the experiment

  17. Quantitative code accuracy evaluation of ISP33

    Kalli, H.; Miwrrin, A. [Lappeenranta Univ. of Technology (Finland); Purhonen, H. [VTT Energy, Lappeenranta (Finland)] [and others

    1995-09-01

    Aiming at quantifying code accuracy, a methodology based on the Fast Fourier Transform has been developed at the University of Pisa, Italy. The paper deals with a short presentation of the methodology and its application to pre-test and post-test calculations submitted to the International Standard Problem ISP33. This was a double-blind natural circulation exercise with a stepwise reduced primary coolant inventory, performed in PACTEL facility in Finland. PACTEL is a 1/305 volumetrically scaled, full-height simulator of the Russian type VVER-440 pressurized water reactor, with horizontal steam generators and loop seals in both cold and hot legs. Fifteen foreign organizations participated in ISP33, with 21 blind calculations and 20 post-test calculations, altogether 10 different thermal hydraulic codes and code versions were used. The results of the application of the methodology to nine selected measured quantities are summarized.

  18. Accuracy verification methods theory and algorithms

    Mali, Olli; Repin, Sergey

    2014-01-01

    The importance of accuracy verification methods was understood at the very beginning of the development of numerical analysis. Recent decades have seen a rapid growth of results related to adaptive numerical methods and a posteriori estimates. However, in this important area there often exists a noticeable gap between mathematicians creating the theory and researchers developing applied algorithms that could be used in engineering and scientific computations for guaranteed and efficient error control.   The goals of the book are to (1) give a transparent explanation of the underlying mathematical theory in a style accessible not only to advanced numerical analysts but also to engineers and students; (2) present detailed step-by-step algorithms that follow from a theory; (3) discuss their advantages and drawbacks, areas of applicability, give recommendations and examples.

  19. Enhancing spoken connected-digit recognition accuracy by error correction codes – A novel scheme

    Sunil K Kopparapu; P V S Rao

    2004-10-01

    Recognizing spoken connected-digit numbers accurately is an important problem and has very many applications. Though state-of-the-art word recognition systems have gained acceptable accuracy levels, the accuracy of recognition of current connected spoken digits (and other short words) is very poor. In this paper, we develop a novel scheme to enhance the accuracy of recognizing a connected number. The basic idea proposed in this paper is to increase the number of digits in a number and use these appended digits to increase the overall accuracy of recognizing the number, as is done in the error-correcting code literature. We further show that the developed scheme is able to uniquely and exactly correct single-digit errors.

  20. A note on the accuracy of spectral method applied to nonlinear conservation laws

    Shu, Chi-Wang; Wong, Peter S.

    1994-01-01

    Fourier spectral method can achieve exponential accuracy both on the approximation level and for solving partial differential equations if the solutions are analytic. For a linear partial differential equation with a discontinuous solution, Fourier spectral method produces poor point-wise accuracy without post-processing, but still maintains exponential accuracy for all moments against analytic functions. In this note we assess the accuracy of Fourier spectral method applied to nonlinear conservation laws through a numerical case study. We find that the moments with respect to analytic functions are no longer very accurate. However the numerical solution does contain accurate information which can be extracted by a post-processing based on Gegenbauer polynomials.

  1. Meteor orbit determination with improved accuracy

    Dmitriev, Vasily; Lupovla, Valery; Gritsevich, Maria

    2015-08-01

    Modern observational techniques make it possible to retrive meteor trajectory and its velocity with high accuracy. There has been a rapid rise in high quality observational data accumulating yearly. This fact creates new challenges for solving the problem of meteor orbit determination. Currently, traditional technique based on including corrections to zenith distance and apparent velocity using well-known Schiaparelli formula is widely used. Alternative approach relies on meteoroid trajectory correction using numerical integration of equation of motion (Clark & Wiegert, 2011; Zuluaga et al., 2013). In our work we suggest technique of meteor orbit determination based on strict coordinate transformation and integration of differential equation of motion. We demonstrate advantage of this method in comparison with traditional technique. We provide results of calculations by different methods for real, recently occurred fireballs, as well as for simulated cases with a priori known retrieval parameters. Simulated data were used to demonstrate the condition, when application of more complex technique is necessary. It was found, that for several low velocity meteoroids application of traditional technique may lead to dramatically delusion of orbit precision (first of all, due to errors in Ω, because this parameter has a highest potential accuracy). Our results are complemented by analysis of sources of perturbations allowing to quantitatively indicate which factors have to be considered in orbit determination. In addition, the developed method includes analysis of observational error propagation based on strict covariance transition, which is also presented.Acknowledgements. This work was carried out at MIIGAiK and supported by the Russian Science Foundation, project No. 14-22-00197.References:Clark, D. L., & Wiegert, P. A. (2011). A numerical comparison with the Ceplecha analytical meteoroid orbit determination method. Meteoritics & Planetary Science, 46(8), pp. 1217

  2. Improvement in measurement accuracy for hybrid scanner

    The capability to provide dense three-dimensional (3D) data (point clouds) at high speed and at high accuracy has made terrestrial laser scanners (TLS) widely used for many purposes especially for documentation, management and analysis. However, similar to other 3D sensors, proper understanding regarding the error sources is necessary to ensure high quality data. A procedure known as calibration is employed to evaluate these errors. This process is crucial for TLS in order to make it suitable for accurate 3D applications (e.g. industrial measurement, reverse engineering and monitoring). Two calibration procedures available for TLS: 1) component, and 2) system calibration. The requirements of special laboratories and tools which are not affordable by most TLS users have become principle drawback for component calibration. In contrast, system calibration only requires a room with appropriate targets. By employing optimal network configuration, this study has performed system calibration through self-calibration for Leica ScanStation C10 scanner. A laboratory with dimensions of 15.5 m × 9 m × 3 m and 138 well-distributed planar targets were used to derive four calibration parameters. Statistical analysis (e.g. t-test) has shown that only two calculated parameters, the constant rangefinder offset error (0.7 mm) and the vertical circle index error (−45.4) were significant for the calibrated scanner. Photogrammetric technique was utilised to calibrate the 3D test points at the calibration field. By using the test points, the residual pattern of raw data and self-calibration results were plotted into the graph to visually demonstrate the improvement in accuracy for Leica ScanStation C10 scanner

  3. Improving Accuracy of Image Classification Using GIS

    Gupta, R. K.; Prasad, T. S.; Bala Manikavelu, P. M.; Vijayan, D.

    The Remote Sensing signal which reaches sensor on-board the satellite is the complex aggregation of signals (in agriculture field for example) from soil (with all its variations such as colour, texture, particle size, clay content, organic and nutrition content, inorganic content, water content etc.), plant (height, architecture, leaf area index, mean canopy inclination etc.), canopy closure status and atmospheric effects, and from this we want to find say, characteristics of vegetation. If sensor on- board the satellite makes measurements in n-bands (n of n*1 dimension) and number of classes in an image are c (f of c*1 dimension), then considering linear mixture modeling the pixel classification problem could be written as n = m* f +, where m is the transformation matrix of (n*c) dimension and therepresents the error vector (noise). The problem is to estimate f by inverting the above equation and the possible solutions for such problem are many. Thus, getting back individual classes from satellite data is an ill-posed inverse problem for which unique solution is not feasible and this puts limit to the obtainable classification accuracy. Maximum Likelihood (ML) is the constraint mostly practiced in solving such a situation which suffers from the handicaps of assumed Gaussian distribution and random nature of pixels (in-fact there is high auto-correlation among the pixels of a specific class and further high auto-correlation among the pixels in sub- classes where the homogeneity would be high among pixels). Due to this, achieving of very high accuracy in the classification of remote sensing images is not a straight proposition. With the availability of the GIS for the area under study (i) a priori probability for different classes could be assigned to ML classifier in more realistic terms and (ii) the purity of training sets for different thematic classes could be better ascertained. To what extent this could improve the accuracy of classification in ML classifier

  4. Charging Levels of Four tRNA Species in Escherichia coli Rel+ and REL- Strains during Amino Acid Starvation: A Simple Model for the Effect of ppGpp on Translational Accuracy

    Sørensen, M.A.

    2001-01-01

    Escherichia coli strains mutated in the relA gene lack the ability to produce ppGpp during amino acid starvation. One consequence of this deficiency is a tenfold increase in misincorporation at starved codons compared to the wild-type. Previous work had shown that the charging levels of tRNAs were...

  5. Accuracy Assessment Points for Tuzigoot National Monument Vegetation Mapping Project

    National Park Service, Department of the Interior — The accuracy assessment field work was performed in May, 1997 to verify the accuracy of the vegetation communities spatial data developed by the USGS-NPS Vegetation...

  6. Accuracy Assessment Points for Voyageurs National Park Vegetation Mapping Project

    National Park Service, Department of the Interior — Thematic accuracy requirements for the USGS-NPS Vegetation Mapping Program specify 80% accuracy for each map unit that represents USNVC floristic types. A total of...

  7. Higgs boson decay into b-quarks at NNLO accuracy

    Del Duca, Vittorio; Somogyi, Gabor; Tramontano, Francesco; Trocsanyi, Zoltan

    2015-01-01

    We compute the fully differential decay rate of the Standard Model Higgs boson into b-quarks at next-to-next-to-leading order (NNLO) accuracy in alpha_S. We employ a general subtraction scheme developed for the calculation of higher order perturbative corrections to QCD jet cross sections, which is based on the universal infrared factorization properties of QCD squared matrix elements. We show that the subtractions render the various contributions to the NNLO correction finite. In particular, we demonstrate analytically that the sum of integrated subtraction terms correctly reproduces the infrared poles of the two-loop double virtual contribution to this process. We present illustrative differential distributions obtained by implementing the method in a parton level Monte Carlo program. The basic ingredients of our subtraction scheme, used here for the first time to compute a physical observable, are universal and can be employed for the computation of more involved processes.

  8. Aspects of precision and accuracy in neutron activation analysis

    Analytical results without systematic errors and with accurately known random errors are normally distributed around their true values. Such results may be produced by means of neutron activation analysis both with and without radiochemical separation. When all sources of random variation are known a priori, their effect may be combined with the Poisson statistics characteristic of the counting process, and the standard deviation of a single analytical result may be estimated. The various steps of a complete neutron activation analytical procedure are therefore studied in detail with respect to determining their contribution to the overall variability of the final result. Verification of the estimated standard deviation is carried out by demonstrating the absence of significant unknown random errors through analysing, in replicate, samples covering the range of concentrations and matrices anticipated in actual use. Agreement between the estimated and the observed variability of replicate results is then tested by a simple statistic T based on the chi-square distribution. It is found that results from neutron activation analysis on biological samples can be brought into statistical control. In routine application of methods in statistical control the same statistical test may be used for quality control when some of the actual samples are analysed in duplicate. This analysis of precision serves to detect unknown or unexpected sources of variation of the analytical results, and both random and systematic errors have been discovered in practical trace element investigations in different areas of research. Particularly, at the ultratrace level of concentration where there are few or no standard reference materials for ascertaining the accuracy of results, the proposed quality control based on the analysis of precision combined with neutron activation analysis with radiochemical separation, with an a priori precision independent of the level of concentration, becomes a

  9. 凝固酶阴性葡萄球菌菌种鉴定与苯唑西林耐药凝固酶阴性葡萄球菌检测准确性%Correlation between species-level identification of coagulase-negative staphylococci and accuracy of methicillin resistance coagulase-negative staphylococci detection

    辜依海; 郭秀荣; 张军; 武建; 李小波; 柴阳; 王克

    2009-01-01

    Objective To evaluate accuracy of cefoxitin disk testing for detecting oxacillin resistance coagulase-negative staphylococci (MRCNS). Methods 139 clinical coagulase-negative staphylococci (CNS) were detected with ID32 STAPH. Cefoxitin disk and oxacillin disk testing were used to detect MRCNS. PBP2a was tested by latex agglutination us a reference method. Results 139 CNS isolates were identified to 8 species: Staphylococcus haemolyticus , S. epidermidis , S. hominis , S. xylosus , S. saprophyticus , S. auricularis , S. simulans and S. warneri. The sensitivity and specificity for cefoxtin disk and oxacillin disk testing were 99.0% vs. 86.0% and 91.7% vs. 74.4%, respectively. One S. epidermidis strain was identified to affect the sensitivity of cefoxitin disk testing. S. xylosus, S. warned, and S. saprophyticus were major species related to the decrease of specificity of cefoxitin disk testing. S. haemolyticus, S. hominis, S. simulans and S. auricularis were major species related to the decrease of sensitivity of oxacillin disk testing. And the decrease of specificity of oxacillin disk testing were mainly related to S. hominis , S. simulans , S. xylosus , S. auricularis , S. saprophyticus and S. warneri. Conclusions The accuracy of MRCNS detection by cefoxitin disk testing is varied due to different CNS species. So it is necessary to test PBP2a or mecA gene according to CNS species, especially for S. xylosus, S. warned and S. saprophyticus.%目的 评价凝固酶阴性葡萄球菌(CNS)菌种鉴定与苯唑西林耐药凝固酶阴件葡萄球菌(MRCNS)检测的准确性.方法 139株临床分离CNS,经ID 32 STAPH鉴定到种,用头孢西丁(FOX)、苯唑西林(OXA)纸片扩散法检测MRCNS,以Slidex MRSA detection乳胶凝集法检测青霉素结合蛋白2a(PBP2a)作为参考方法.结果 139株CNS鉴定为8个种,依次为溶血葡萄球菌、表皮葡萄球菌、人葡萄球菌、木糖葡萄球菌、腐生葡萄球菌、耳葡萄球菌、模仿葡萄球菌、沃

  10. 12 CFR 740.2 - Accuracy of advertising.

    2010-01-01

    ... 12 Banks and Banking 6 2010-01-01 2010-01-01 false Accuracy of advertising. 740.2 Section 740.2 Banks and Banking NATIONAL CREDIT UNION ADMINISTRATION REGULATIONS AFFECTING CREDIT UNIONS ACCURACY OF ADVERTISING AND NOTICE OF INSURED STATUS § 740.2 Accuracy of advertising. No insured credit union may use...

  11. Treatment accuracy of fractionated stereotactic radiotherapy

    Background and purpose: To assess the geometric accuracy of the delivery of fractionated stereotactic radiotherapy (FSRT) for brain tumours using the Gill-Thomas-Cosman (GTC) relocatable frame. Accuracy of treatment delivery was measured via portal images acquired with an amorphous silicon based electronic portal imager (EPI). Results were used to assess the existing verification process and to review the current margins used for the expansion of clinical target volume (CTV) to planning target volume (PTV). Patients and methods: Patients were immobilized in a GTC frame. Target volume definition was performed on localization CT and MRI scans and a CTV to PTV margin of 5 mm (based on initial experience) was introduced in 3D. A Brown-Roberts-Wells (BRW) fiducial system was used for stereotactic coordinate definition. The existing verification process consisted of an intercomparison of the coordinates of the isocentres and anatomy between the localization and verification CT scans. Treatment was delivered with 6 MV photons using four fixed non-coplanar conformal fields using a multi-leaf collimator. Portal imaging verification consisted of the acquisition of orthogonal images centred through the treatment isocentre. Digitally reconstructed radiographs (DRRs) created from the CT localization scans were used as reference images. Semi-automated matching software was used to quantify set up deviations (displacements and rotations) between reference and portal images. Results: One hundred and twenty six anterior and 123 lateral portal images were available for analysis for set up deviations. For displacements, the total errors in the cranial/caudal direction were shown to have the largest SD's of 1.2 mm, while systematic and random errors reached SD's of 1.0 and 0.7 mm, respectively, in the cranial/caudal direction. The corresponding data for rotational errors (the largest deviation was found in the sagittal plane) was 0.7 deg. SD (total error), 0.5 deg. (systematic) and 0

  12. The accuracy of X-ray fluorescence spectrometric determination of Rb and Sr contents in rock sample

    It is shown that application of the Compton scattering method in the X-ray fluorescence spectrometric determination of the trace elements Rb and Sr in rock samples can provide element contents at an accuracy level +- 1 %

  13. Trust in automation and meta-cognitive accuracy in NPP operating crews

    Nuclear power plant operators can over-trust or under-trust automation. Operator trust in automation is said to be mis-calibrated when the level of trust is not corresponding to the actual level of automation reliability. A possible consequence of mis-calibrated trust is degraded meta-cognitive accuracy. Meta-cognitive accuracy is the ability to correctly monitor the effectiveness of ones own performance while engaged in complex tasks. When operators misjudge their own performance, human control actions will be poorly regulated and safety and/or efficiency may suffer. An analysis of simulator data showed that meta-cognitive accuracy and trust in automation were highly correlated for knowledge-based scenarios, but uncorrelated for rule-based scenarios. In the knowledge-based scenarios, the operators overestimated their performance effectiveness under high levels of trust, they underestimated performance under low levels of trust, but showed realistic self-assessment under intermediate levels of trust in automation. The result was interpreted to suggest that trust in automation impact the meta-cognitive accuracy of the operators. (authors)

  14. Accuracy of results with NASTRAN modal synthesis

    Herting, D. N.

    1978-01-01

    A new method for component mode synthesis was developed for installation in NASTRAN level 17.5. Results obtained from the new method are presented, and these results are compared with existing modal synthesis methods.

  15. High-accuracy measurements on biperiodical circuits

    Coupled resonators in an assembled structure lose their individuality and in co-operation contribute to the generation of structure modes (resonant frequencies). The resonant frequencies of these modes are the only measurable quantities. In order to predict structural behaviour in a variety of cases, the problem that arises is the extraction of all the parameters characterizing the structure from the measurements mentioned here. If all the modes are confined in a bandwidth that is small with respect to the central frequency, the total coupled resonator system is well represented by a circuit of unknown lumped constants.The structure modes are the solutions of the equation obtained by equating to zero the determinant relevant to the lumped circuit representation. The equation is a polynomial of the squared frequency variable, the degree of which is equal to the number M of circuits.The analysis method described in this paper consists in varying, by an unknown amount, the frequency of a single resonator in the chain. This variation will produce a change in the frequencies of all structure modes. It is possible to find certain invariants linearly dependent on all the unchanged parameters of the circuit. These invariants have an algebraic representation that allows the extraction of the structure parameter values with extremely high accuracy. The proposed method is quite general and, in the present work, we give an example applying the method to the characterization of a side-coupled linac (SCL). (paper)

  16. Mass spectrometry accuracy improvement using two tracers

    The accuracy of the isotopic analyses performed by thermoionization mass spectrometry is limited by the effects of isotopic fractionation that occurs during the evaporation of the sample placed on the filament. It results in a continuous change over time of the isotopic compound determined. In order to determine the factor enabling the isotopic fractionation of the uranium to be adjusted, the mass spectrometers are calibrated by using isotopic standards of uranium. The adjusting factor K, defined as 235U/238U theoretical / 235U/238U determined is independent of the value of the 235U/238U ratio, but it has a relative random error of around +-0.28 to +-0.5%. The completion of very accurate isotopic analyses therefore calls for the application of a severe operational mode. Automation of all the sequences of the analysis appears to be the only valid method for attaining this objective, but it remains a very costly solution. These difficulties motivated the studies on the use of an internal standard for directly correcting the effects of isotopic fractionation, constituted of a 233 and 236 uranium solution of which the 236/233 ratio was determined accurately beforehand

  17. Accuracy preserving surrogate for neutron transport calculations

    Recent advances in reduced order modeling and exact-to-precision generalized perturbation theory are combined in a novel algorithm that constructs a surrogate model for the Boltzmann equation, commonly used in assembly calculations to functionalize the few-group cross-sections in terms of the various assembly types, depletion characteristics, and thermal-hydraulics conditions. First, the algorithm employs reduced order modeling to determine the dominant input parameters, aggregated in the so-called active subspace, using a random sample of first-order derivatives calculated using an adjoint model. Next, exact-to-precision generalized perturbation theory identifies an active subspace for the state solution (i.e., angular flux) and constructs a surrogate model that is parameterized over the active subspace of the input parameters. This approach is shown to significantly reduce computational time needed for the analysis of a large number of model variations, while meeting the user-defined accuracy requirements. Numerical experiments are employed to demonstrate the mechanics and application of the proposed approach to assembly calculations commonly used in reactor physics analysis. (author)

  18. Needle placement accuracy during stereotactic localization mammography

    Aim: To derive a mathematical model to describe the relationship between lesion position in the breast and measurements derived from the stereoradiographs to enable more accurate sampling of a lesion during stereotactic mammographic needle placement. Materials and methods: The affect that registration errors have on the accuracy of needle placement when identifying the lesion on the stereoradiographs was investigated using the mathematical model. Results: The focus-to-film distance of the x-ray tube and the horizontal distance of the lesion from the centre of rotation have little effect on error. Registration errors for lesions lying at a greater perpendicular distance in the breast from the centre of rotation produce smaller localization errors when compared with lesions sited closer. Lesion registration errors during marking of the stereoradiographs are exacerbated by decreasing the angle of x-ray tube swing. Conclusions: When problems are encountered in making an accurate registration of the lesion on the stereoradiographs, consider the following error reducing strategies: (1) employ an approach that places the lesion the maximum distance away from the film cassette; (2) avoid reducing the angle of tube swing; and (3) consider sampling superficial and deep to, as well as at, the location indicated. The possibility of erroneous tissue sampling should be borne in mind when reviewing the pathology report.

  19. A non-linear learning & classification algorithm that achieves full training accuracy with stellar classification accuracy

    Khogali, Rashid

    2014-01-01

    A fast Non-linear and non-iterative learning and classification algorithm is synthesized and validated. This algorithm named the "Reverse Ripple Effect(R.R.E)", achieves 100% learning accuracy but is computationally expensive upon classification. The R.R.E is a (deterministic) algorithm that super imposes Gaussian weighted functions on training points. In this work, the R.R.E algorithm is compared against known learning and classification techniques/algorithms such as: the Perceptron Criterio...

  20. Kinematics of a striking task: accuracy and speed-accuracy considerations.

    Parrington, Lucy; Ball, Kevin; MacMahon, Clare

    2015-01-01

    Handballing in Australian football (AF) is the most efficient passing method, yet little research exists examining technical factors associated with accuracy. This study had three aims: (a) To explore the kinematic differences between accurate and inaccurate handballers, (b) to compare within-individual successful (hit target) and unsuccessful (missed target) handballs and (c) to assess handballing when both accuracy and speed of ball-travel were combined using a novel approach utilising canonical correlation analysis. Three-dimensional data were collected on 18 elite AF players who performed handballs towards a target. More accurate handballers exhibited a significantly straighter hand-path, slower elbow angular velocity and smaller elbow range of motion (ROM) compared to the inaccurate group. Successful handballs displayed significantly larger trunk ROM, maximum trunk rotation velocity and step-angle and smaller elbow ROM in comparison to the unsuccessful handballs. The canonical model explained 73% of variance shared between the variable sets, with a significant relationship found between hand-path, elbow ROM and maximum elbow angular velocity (predictors) and hand-speed and accuracy (dependant variables). Interestingly, not all parameters were the same across each of the analyses, with technical differences between inaccurate and accurate handballers different from those between successful and unsuccessful handballs in the within-individual analysis. PMID:25079111

  1. The level 2 and 3 modular invariants of SU(n)

    Gannon, Terry

    1995-01-01

    In this paper we explicitly classify all modular invariant partition functions for su(n) at level 2 and 3. Previously, these were known only for level 1. The level 2 exceptionals exist at n=10, 16, and 28; the level 3 exceptionals exist at n=5, 9, and 21. One of these is new, but the others were all anticipated by the "rank-level duality" relating su(n) level k and su(k) level n. The main recent result which this paper rests on is the classification of "ADE_7-type invariants".

  2. Diagnostic accuracy of spirometry in primary care

    Dinant Geert-Jan

    2009-07-01

    Full Text Available Abstract Background To evaluate the sensitivity, specificity and predictive values of spirometry for the diagnosis of chronic obstructive pulmonary disease (COPD and asthma in patients suspected of suffering from an obstructive airway disease (OAD in primary care. Methods Cross sectional diagnostic study of 219 adult patients attending 10 general practices for the first time with complaints suspicious for OAD. All patients underwent spirometry and structured medical histories were documented. All patients received whole-body plethysmography (WBP in a lung function laboratory. The reference standard was the Tiffeneau ratio (FEV1/VC received by the spirometric maneuver during examination with WBP. In the event of inconclusive results, bronchial provocation was performed to determine bronchial hyper-responsiveness (BHR. Asthma was defined as a PC20 fall after inhaling methacholine concentration ≤ 16 mg/ml. Results 90 (41.1% patients suffered from asthma, 50 (22.8% suffered from COPD, 79 (36.1% had no OAD. The sensitivity for diagnosing airway obstruction in COPD was 92% (95%CI 80–97; specificity was 84% (95%CI 77–89. The positive predictive value (PPV was 63% (95%CI 51–73; negative predictive value (NPV was 97% (95%CI 93–99. The sensitivity for diagnosing airway obstruction in asthma was 29% (95%CI 21–39; specificity was 90% (95%CI 81–95. PPV was 77% (95%CI 60–88; NPV was 53% (95%CI 45–61. Conclusion COPD can be estimated with high diagnostic accuracy using spirometry. It is also possible to rule in asthma with spirometry. However, asthma can not be ruled out only using spirometry. This diagnostic uncertainty leads to an overestimation of asthma presence. Patients with inconclusive spirometric results should be referred for nitric oxide (NO – measurement and/or bronchial provocation if possible to guarantee accurate diagnosis.

  3. Accuracy of experimental partial structure factors

    For the discussion of the partial structure factors, a Figure of Merit (T) was suggested to design a proper experimental condition. In order to determine uniquely the partial structure factors in a binary alloy, three experiments are required, in which the scattering power of one or both elements, is varied. The measured scattering factors I(Q) from a binary alloy of composition A(1-x)B(x) are obtained for respective experiments. Then, the solution S(Q) is derived, and the error in I(Q) contributes to the error in S(Q). A measure of conditioning can be derived by the consideration of vector and matrix norms leading to a figure of merit called Turin's number T. The figure of merit, when multiplied by the expected errors in the measured intensity functions, the composition, and/or the values of the scattering length, gives an upper estimate of the expected errors in partial structure factors. In order to assess the accuracy required, a typical partial structure factor (the Pd-Pd pSF from a model of Pd(4)Si) was modified. By carefully choosing the system and optimizing the composition, good T's were able to be found for metallic glass-forming alloys. The best T found to date was for the Ni-Zr system using the Ni58 and Ni62 isotopes, and the T was 4.8. The techniques, which are complementary to the isotopic substitution method in Ni-Zr, are discussed. The expected errors in the partials were found to be small enough for extracting directly useful information. (Kato, T.)

  4. Multiple motives and persuasive communication : Creative elaboration as a result of impression motivation and accuracy motivation

    Nienhuis, AE; Manstead, ASR; Spears, R

    2001-01-01

    The authors examined the influence of impression motivation (Experiments 1 and 2) and the combined effects of accuracy motivation and impression motivation (Experiment 3) on the elaboration of persuasive messages as reflected in attitude change and cognitive responses. Intermediate levels of impress

  5. The Accuracy of Metacomprehension Judgments: The Biasing Effect of Text Order

    Linderholm, Tracy; Wang, Xuesong; Therriault, David; Zhao, Qin; Jakiel, Laura

    2012-01-01

    Introduction: Two experiments tested the hypothesis that relative metacomprehension accuracy is vulnerable when readers' cognitive efforts are biased by text order. It is proposed that the difficulty level of initial text information biases readers' estimates of text comprehension but is correctable when more cognitive effort is applied. Method:…

  6. Predictive Validity and Accuracy of Oral Reading Fluency for English Learners

    Vanderwood, Michael L.; Tung, Catherine Y.; Checca, C. Jason

    2014-01-01

    The predictive validity and accuracy of an oral reading fluency (ORF) measure for a statewide assessment in English language arts was examined for second-grade native English speakers (NESs) and English learners (ELs) with varying levels of English proficiency. In addition to comparing ELs with native English speakers, the impact of English…

  7. The Effects of Stimulus Modification on Putting Accuracy for Adults with Severe or Profound Mental Retardation.

    Bolton, Jenifer L.; And Others

    1994-01-01

    This study found that, following a systematic fading of putting guides, three adults with severe/profound mental retardation increased accuracy in making putts during posttraining assessments on a practice green. Results also maintained at, or increased above, posttraining levels at a two-week maintenance check and were generalized to a local golf…

  8. Classification Accuracy of Nonword Repetition when Used with Preschool-Age Spanish-Speaking Children

    Guiberson, Mark; Rodriguez, Barbara L.

    2013-01-01

    Purpose: The purpose of the present study was to (a) describe and compare the nonword repetition (NWR) performance of preschool-age Spanish-speaking children (3- to 5-year-olds) with and without language impairment (LI) across 2 scoring approaches and (b) to contrast the classification accuracy of a Spanish NWR task when item-level and percentage…

  9. Influence of coronary calcification on the diagnostic accuracy of 64-slice computed tomography coronary angiography

    Abdulla, Jawdat; Pedersen, Kasper; Budoff, Matthew;

    2012-01-01

    To determine via meta-analysis the diagnostic accuracy of 64-slice computed tomography coronary angiography (CTA) for assessment of significant obstructive coronary artery stenosis at different coronary artery calcium score (CACS) levels. Data of 12,053 versus 5,890 segments, 906 versus 758 arter...

  10. Decision Accuracy and the Role of Spatial Interaction in Opinion Dynamics

    Torney, Colin J.; Levin, Simon A.; Couzin, Iain D.

    2013-04-01

    The opinions and actions of individuals within interacting groups are frequently determined by both social and personal information. When sociality (or the pressure to conform) is strong and individual preferences are weak, groups will remain cohesive until a consensus decision is reached. When group decisions are subject to a bias, representing for example private information known by some members of the population or imperfect information known by all, then the accuracy achieved for a fixed level of bias will increase with population size. In this work we determine how the scaling between accuracy and group size can be related to the microscopic properties of the decision-making process. By simulating a spatial model of opinion dynamics we show that the relationship between the instantaneous fraction of leaders in the population ( L), system size ( N), and accuracy depends on the frequency of individual opinion switches and the level of population viscosity. When social mixing is slow, and individual opinion changes are frequent, accuracy is determined by the absolute number of informed individuals. As mixing rates increase, or the rate of opinion updates decrease, a transition occurs to a regime where accuracy is determined by the value of L√{ N}. We investigate the transition between different scaling regimes analytically by examining a well-mixed limit.

  11. Wind Prediction Accuracy for Air Traffic Management Decision Support Tools

    Cole, Rod; Green, Steve; Jardin, Matt; Schwartz, Barry; Benjamin, Stan

    2000-01-01

    The performance of Air Traffic Management and flight deck decision support tools depends in large part on the accuracy of the supporting 4D trajectory predictions. This is particularly relevant to conflict prediction and active advisories for the resolution of conflicts and the conformance with of traffic-flow management flow-rate constraints (e.g., arrival metering / required time of arrival). Flight test results have indicated that wind prediction errors may represent the largest source of trajectory prediction error. The tests also discovered relatively large errors (e.g., greater than 20 knots), existing in pockets of space and time critical to ATM DST performance (one or more sectors, greater than 20 minutes), are inadequately represented by the classic RMS aggregate prediction-accuracy studies of the past. To facilitate the identification and reduction of DST-critical wind-prediction errors, NASA has lead a collaborative research and development activity with MIT Lincoln Laboratories and the Forecast Systems Lab of the National Oceanographic and Atmospheric Administration (NOAA). This activity, begun in 1996, has focussed on the development of key metrics for ATM DST performance, assessment of wind-prediction skill for state of the art systems, and development/validation of system enhancements to improve skill. A 13 month study was conducted for the Denver Center airspace in 1997. Two complementary wind-prediction systems were analyzed and compared to the forecast performance of the then standard 60 km Rapid Update Cycle - version 1 (RUC-1). One system, developed by NOAA, was the prototype 40-km RUC-2 that became operational at NCEP in 1999. RUC-2 introduced a faster cycle (1 hr vs. 3 hr) and improved mesoscale physics. The second system, Augmented Winds (AW), is a prototype en route wind application developed by MITLL based on the Integrated Terminal Wind System (ITWS). AW is run at a local facility (Center) level, and updates RUC predictions based on an

  12. The ripple electromagnetic calculation: accuracy demand and possible responses

    Due to a number of causes (the finite number of toroidal field coils or the presence of concentrate blocks of magnetic materials, as the neutral beam shielding) the actual magnetic configuration in a Tokamak differs from the desired one. For example, a ripple is added to the ideal axisymmetric toroidal field, impacting the equilibrium and stability of the plasma column; as a further example the magnetic field out of plasma affects the operation of a number of critical components, included the diagnostic system and the neutral beam. Therefore the actual magnetic field has to be suitably calculated and his shape controlled within the required limits. Due to the complexity of its design, the problem is quite critical for the ITER project. In this paper the problem is discussed both from mathematical and numerical point of view. In particular, a complete formulation is proposed, taking into account both the presence of the non linear magnetic materials and the fully 3D geometry. Then the quality level requirements are discussed, included the accuracy of calculations and the spatial resolution. As a consequence, the numerical tools able to fulfil the quality needs while requiring reasonable computer burden are considered. In particular possible tools based on numerical FEM scheme are considered; in addition, in spite of the presence of non linear materials, the practical possibility to use Biot-Savart based approaches, as cross check tools, is also discussed. The paper also analyses the possible geometrical simplifications of the geometry able to make possible the actual calculation while guarantying the required accuracy. Finally the characteristics required for a correction system able to effectively counteract the magnetic field degradation are presented. Of course a number of examples will be also reported and commented. (author)

  13. Normal interoceptive accuracy in women with bulimia nervosa.

    Pollatos, Olga; Georgiou, Eleana

    2016-06-30

    Previous studies suggest that patients suffering from bulimia nervosa (BN) have difficulties in perceiving internal bodily signals, mostly assessed by self-report questionnaires. Whether interoception is, in this case, attenuated or not remains an open question. Therefore, interoceptive processes were examined in twenty-three patients with current BN and were compared to healthy participants. We investigated Interoceptive Accuracy (IAc) assessed by the heartbeat detection task and Interoceptive Awareness (IA) assessed by the Eating Disorder Inventory-2. Patients with BN and healthy participants did not differ in terms of IAc when controlling for BMI, depression and anxiety, whereas IA among BN patients was found to have decreased. Although IAc and IA were not related among controls, we observed an inverse correlation in BN, suggesting that an abnormal overlap between these two levels of interoceptive signal processing is present in BN. The current study introduces a new perspective concerning the role of interoceptive processes in BN and generates further questions regarding the therapeutic utility of methods targeting the interaction between different levels of interoception in the treatment of BN. PMID:27138826

  14. Accuracy of quantitative visual soil assessment

    van Leeuwen, Maricke; Heuvelink, Gerard; Stoorvogel, Jetse; Wallinga, Jakob; de Boer, Imke; van Dam, Jos; van Essen, Everhard; Moolenaar, Simon; Verhoeven, Frank; Stoof, Cathelijne

    2016-04-01

    Visual soil assessment (VSA) is a method to assess soil quality visually, when standing in the field. VSA is increasingly used by farmers, farm organisations and companies, because it is rapid and cost-effective, and because looking at soil provides understanding about soil functioning. Often VSA is regarded as subjective, so there is a need to verify VSA. Also, many VSAs have not been fine-tuned for contrasting soil types. This could lead to wrong interpretation of soil quality and soil functioning when contrasting sites are compared to each other. We wanted to assess accuracy of VSA, while taking into account soil type. The first objective was to test whether quantitative visual field observations, which form the basis in many VSAs, could be validated with standardized field or laboratory measurements. The second objective was to assess whether quantitative visual field observations are reproducible, when used by observers with contrasting backgrounds. For the validation study, we made quantitative visual observations at 26 cattle farms. Farms were located at sand, clay and peat soils in the North Friesian Woodlands, the Netherlands. Quantitative visual observations evaluated were grass cover, number of biopores, number of roots, soil colour, soil structure, number of earthworms, number of gley mottles and soil compaction. Linear regression analysis showed that four out of eight quantitative visual observations could be well validated with standardized field or laboratory measurements. The following quantitative visual observations correlated well with standardized field or laboratory measurements: grass cover with classified images of surface cover; number of roots with root dry weight; amount of large structure elements with mean weight diameter; and soil colour with soil organic matter content. Correlation coefficients were greater than 0.3, from which half of the correlations were significant. For the reproducibility study, a group of 9 soil scientists and 7

  15. Accuracy of quantitative visual soil assessment

    van Leeuwen, Maricke; Heuvelink, Gerard; Stoorvogel, Jetse; Wallinga, Jakob; de Boer, Imke; van Dam, Jos; van Essen, Everhard; Moolenaar, Simon; Verhoeven, Frank; Stoof, Cathelijne

    2016-04-01

    Visual soil assessment (VSA) is a method to assess soil quality visually, when standing in the field. VSA is increasingly used by farmers, farm organisations and companies, because it is rapid and cost-effective, and because looking at soil provides understanding about soil functioning. Often VSA is regarded as subjective, so there is a need to verify VSA. Also, many VSAs have not been fine-tuned for contrasting soil types. This could lead to wrong interpretation of soil quality and soil functioning when contrasting sites are compared to each other. We wanted to assess accuracy of VSA, while taking into account soil type. The first objective was to test whether quantitative visual field observations, which form the basis in many VSAs, could be validated with standardized field or laboratory measurements. The second objective was to assess whether quantitative visual field observations are reproducible, when used by observers with contrasting backgrounds. For the validation study, we made quantitative visual observations at 26 cattle farms. Farms were located at sand, clay and peat soils in the North Friesian Woodlands, the Netherlands. Quantitative visual observations evaluated were grass cover, number of biopores, number of roots, soil colour, soil structure, number of earthworms, number of gley mottles and soil compaction. Linear regression analysis showed that four out of eight quantitative visual observations could be well validated with standardized field or laboratory measurements. The following quantitative visual observations correlated well with standardized field or laboratory measurements: grass cover with classified images of surface cover; number of roots with root dry weight; amount of large structure elements with mean weight diameter; and soil colour with soil organic matter content. Correlation coefficients were greater than 0.3, from which half of the correlations were significant. For the reproducibility study, a group of 9 soil scientists and 7

  16. Liquid level measurement in high level nuclear waste slurries

    Accurate liquid level measurement has been a difficult problem to solve for the Defense Waste Processing Facility (DWPF). The nuclear waste sludge tends to plug or degrade most commercially available liquid-level measurement sensors. A liquid-level measurement system that meets demanding accuracy requirements for the DWPF has been developed. The system uses a pneumatic 1:1 pressure repeater as a sensor and a computerized error correction system. 2 figs

  17. Evaluating the accuracy of value-at-risk forecasts: New multilevel tests

    Leccadito, A; Boffelli, S; Urga, G.

    2014-01-01

    We propose independence and conditional coverage tests aimed at evaluating the accuracy of Value-at-Risk (VaR) forecasts from the same model at different confidence levels. The proposed procedures are multilevel tests, i.e. joint tests of several quantiles corresponding to different confidence levels. In a comprehensive Monte Carlo exercise, we document the superiority of the proposed tests with respect to existing multilevel tests. In an empirical application, we illustrate the implementatio...

  18. Diagnostic Accuracy of the Posttraumatic Stress Disorder Checklist–Civilian Version in a Representative Military Sample

    Karstoft, Karen-Inge; Andersen, Søren B.; Bertelsen, Mette; Madsen, Trine

    2014-01-01

    . Diagnostic accuracy of the PCL-C was assessed through receiver operating characteristic curve analysis. The PCL-C displayed high overall accuracy (area under the curve = .95, confidence interval [.92, .98]) and performed well (sensitivity > .70 and specificity ≥ .90), with cutoff scores ranging from 37 to 44....... When including sensitivity values a little below .70 (.69), the PCL-C performed well for cutoff levels up to 53. Prevalence of PTSD varied considerably with the application of different cutoff values and scoring methods. Our results show that the PCL-C is a relevant and valid tool for screening for...

  19. BENCHMARKING THE ACCURACY OF INERTIAL SENSORS IN CELL PHONES

    An, Bin

    2012-01-01

    Many ubiquitous computing applications rely on data from a cell phone's inertial sensors. Unfortunately, the accuracy of this data is often unknown, which impedes predictive analysis of applications that require high sensor accuracy (e.g., dead reckoning). This work focuses on benchmarking the accuracy of the accelerometers and gyroscopes on a cell phone. The cell phones are attached to a robotic arm, which provides ground truth measurements. The misalignment between the cell phone's and the ...

  20. Influence of Exposure Time on Prototyping Accuracy in Stereolithography

    吴懋亮; 方明伦; 胡庆夕; 戴春祥; 卢秉恒

    2004-01-01

    A novel stereolithgraphy system with conventional UV light as a light source uses the 2D worktable as moving components,whose characteristics determine the accuracy of the prototyping parts. Many factors including mass of the worktable, elasticity and damp coefficients, speed and acceleration affect the non-uniform exposure time of the resin, and eventually influence the cured line shape and the curing accuracy. A light shuttle is used to eliminate the cure errors, greatly improving accuracy of the parts.

  1. Airborne Topographic Mapper Calibration Procedures and Accuracy Assessment

    Martin, Chreston F.; Krabill, William B.; Manizade, Serdar S.; Russell, Rob L.; Sonntag, John G.; Swift, Robert N.; Yungel, James K.

    2012-01-01

    Description of NASA Airborn Topographic Mapper (ATM) lidar calibration procedures including analysis of the accuracy and consistancy of various ATM instrument parameters and the resulting influence on topographic elevation measurements. The ATM elevations measurements from a nominal operating altitude 500 to 750 m above the ice surface was found to be: Horizontal Accuracy 74 cm, Horizontal Precision 14 cm, Vertical Accuracy 6.6 cm, Vertical Precision 3 cm.

  2. Wavelength Calibration Accuracy for the STIS CCD and MAMA Modes

    Pascucci, Ilaria; Hodge, Phil; Proffitt, Charles R.; Ayres, T.

    2011-03-01

    Two calibration programs were carried out to determine the accuracy of the wavelength solutions for the most used STIS CCD and MAMA modes after Servicing Mission 4. We report here on the analysis of this dataset and show that the STIS wavelength solution has not changed after SM4. We also show that a typical accuracy for the absolute wavelength zero-points is 0.1 pixels while the relative wavelength accuracy is 0.2 pixels.

  3. A Suite of Tools for Assessing Thematic Map Accuracy

    Jean-François Mas; Azucena Pérez-Vega; Adrián Ghilardi; Silvia Martínez; Jaime Octavio Loya-Carrillo; Ernesto Vega

    2014-01-01

    Although land use/cover maps are widely used to support management and environmental policies, only some studies have reported their accuracy using sound and complete assessments. Thematic map accuracy assessment is typically achieved by comparing reference sites labeled with the “ground-truth” category to the ones depicted in the land use/cover map. A variety of sampling designs are used to select these references sites. The estimators for accuracy indices and the variance of these estimator...

  4. Free and total testosterone levels in field males of Octodon degus (Rodentia, Octodontidae: accuracy of the hormonal regulation of behavior Niveles de testosterona libre y totales en machos silvestres de Octodon degus (Rodentia, Octodontidae: exactitud de la regulación hormonal del comportamiento

    MAURICIO SOTO- GAMBOA

    2005-06-01

    Full Text Available Animals exhibit continuous seasonal changes in physiological, morphological and behavioral traits associated to their natural annual cycles. One of the most important changes in the organism occurs at the initiation of breeding season. In males these changes include activation of spermatogenesis, enhance of sexual secondary characters and an increase of aggressiveness. All of theses changes are basically regulated by testosterone, but the physiological basis of this testosterone regulation and the effective hormone proportion that acts in target tissues are unknown. In this work I evaluated the relationship between total testosterone, free testosterone associated to aggressive behavior in wild males of Octodon degus. I compared hormonal levels and aggressive behavior during pre, middle and post breeding periods. Results showed that behavioral aggressiveness was correlated with both total and free testosterone in June, during the beginning of breeding season, but not at other times. Results also indicated a lack of relationship between free and total testosterone in most of breeding period. I discuss the importance of this behavior-hormonal regulation (determined by free testosterone and the physiological importance of this mechanism to the organismLos animales presentan variaciones estacionales continuas que incluyen cambios fisiológicos, morfológicos y conductuales, asociados al ciclo anual. Estos cambios generalmente están activados por factores endógenos o exógenos, pero son regulados por el sistema endocrino de organismo. Uno de los cambios más importantes ocurre en el inicio del periodo reproductivo. Durante este periodo los machos presentan cambios asociados a la producción de esperatozoides, exacerbación de caracteres sexuales secundarios y un aumento de la agresividad. Todos estos cambios son regulados en parte por los niveles de testosterona, sin embargo, los mecanismos fisiológicos de esta regulación son desconocidos. En este

  5. Accuracy Driven Artificial Neural Networks in Stock Market Prediction

    Selvan Simon

    2012-06-01

    Full Text Available Globalization has made the stock market prediction (SMP accuracy more challenging and rewarding for the researchers and other participants in the stock market. Local and global economic situations alongwith the company’s financial strength and prospects have to be taken into account to improve the prediction accuracy. Artificial Neural Networks (ANN has been identified to be one of the dominant data mining techniques in stock market prediction area. In this paper, we survey different ANN models that have been experimented in SMP with the special enhancement techniques used with them to improve the accuracy. Also, we explore the possible research strategies in this accuracy driven ANN models.

  6. Emitter location accuracy using TDOA and differential Doppler

    Chestnut, P. C.

    1982-03-01

    The time difference of arrival (TDOA) and the differential Doppler methods for locating a radio or sonar transmitter are described, and some relationships between the accuracy of their measurements and the accuracy of the location estimates obtained from the measurements are presented. The formula for the one-sigma width of the lines of constant TDOA and the differential Doppler on the surface of the earth is used to characterize emitter location accuracy. The derived relations can be used by the systems engineer to evaluate proposed systems and to determine system specifications to satisfy given requirements on emitter location accuracy.

  7. Assessment of the Thematic Accuracy of Land Cover Maps

    Höhle, J.

    2015-08-01

    Several land cover maps are generated from aerial imagery and assessed by different approaches. The test site is an urban area in Europe for which six classes (`building', `hedge and bush', `grass', `road and parking lot', `tree', `wall and car port') had to be derived. Two classification methods were applied (`Decision Tree' and `Support Vector Machine') using only two attributes (height above ground and normalized difference vegetation index) which both are derived from the images. The assessment of the thematic accuracy applied a stratified design and was based on accuracy measures such as user's and producer's accuracy, and kappa coefficient. In addition, confidence intervals were computed for several accuracy measures. The achieved accuracies and confidence intervals are thoroughly analysed and recommendations are derived from the gained experiences. Reliable reference values are obtained using stereovision, false-colour image pairs, and positioning to the checkpoints with 3D coordinates. The influence of the training areas on the results is studied. Cross validation has been tested with a few reference points in order to derive approximate accuracy measures. The two classification methods perform equally for five classes. Trees are classified with a much better accuracy and a smaller confidence interval by means of the decision tree method. Buildings are classified by both methods with an accuracy of 99% (95% CI: 95%-100%) using independent 3D checkpoints. The average width of the confidence interval of six classes was 14% of the user's accuracy.

  8. Virtual Teaching Simulation for Robot Assembly Accuracy Analysis

    张征; 周宏甫; 刘斌

    2004-01-01

    In this paper, by teaching a 3D robot unit model and playing back to simulate the assembly process in a virtual assembly environment, errors in robot assembly are analyzed. The paper also presents a visualization method for analyzing accuracy of the robot assembly, and studies the influence of the spatial pose of a robot on the success rate of an axis-hole assembly, and accuracy of the robot teaching program in particular. Through integration of various errors and on the basis of assembly accuracy, tolerance of error sources can be reasonably distributed to meet the assembly accuracy requirement, therefore the planning of robot assembly unit can be improved.

  9. Establishing precision and accuracy in PDV results

    Briggs, Matthew E. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Howard, Marylesa [National Security Technologies, LLC. (NSTec), North Las Vegas, NV (United States); Diaz, Abel [National Security Technologies, LLC. (NSTec), Los Alamos, NM (United States)

    2016-04-19

    We need to know uncertainties and systematic errors because we create and compare against archival weapons data, we constrain the models, and we provide scientific results. Good estimates of precision from the data record are available and should be incorporated into existing results; reanalysis of valuable data is suggested. Estimates of systematic errors are largely absent. The original work by Jensen et al. using gun shots for window corrections, and the integrated velocity comparison with X-rays by Schultz are two examples where any systematic errors appear to be <1% level.

  10. Setup Accuracy of the Novalis ExacTrac 6DOF System for Frameless Radiosurgery

    Purpose: Stereotactic radiosurgery using frame-based positioning is a well-established technique for the treatment of benign and malignant lesions. By contrast, a new trend toward frameless systems using image-guided positioning techniques is gaining mainstream acceptance. This study was designed to measure the detection and positioning accuracy of the ExacTrac/Novalis Body (ET/NB) for rotations and to compare the accuracy of the frameless with the frame-based radiosurgery technique. Methods and Materials: A program was developed in house to rotate reference computed tomography images. The angles measured by the system were compared with the known rotations. The accuracy of ET/NB was evaluated with a head phantom with seven lead beads inserted, mounted on a treatment couch equipped with a robotic tilt module, and was measured with a digital water level and portal films. Multiple hidden target tests (HTT) were performed to measure the overall accuracy of the different positioning techniques for radiosurgery (i.e., frameless and frame-based with relocatable mask or invasive ring, respectively). Results: The ET/NB system can detect rotational setup errors with an average accuracy of 0.09° (standard deviation [SD] 0.06°), 0.02° (SD 0.07°), and 0.06° (SD 0.14°) for longitudinal, lateral, and vertical rotations, respectively. The average positioning accuracy was 0.06° (SD 0.04°), 0.08° (SD 0.06°), and 0.08° (SD 0.07°) for longitudinal, lateral and vertical rotations, respectively. The results of the HTT showed an overall three-dimensional accuracy of 0.76 mm (SD 0.46 mm) for the frameless technique, 0.87 mm (SD 0.44 mm) for the relocatable mask, and 1.19 mm (SD 0.45 mm) for the frame-based technique. Conclusions: The study showed high detection accuracy and a subdegree positioning accuracy. On the basis of phantom studies, the frameless technique showed comparable accuracy to the frame-based approach.

  11. Height Accuracy Based on Different Rtk GPS Method for Ultralight Aircraft Images

    Tahar, K. N.

    2015-08-01

    Height accuracy is one of the important elements in surveying work especially for control point's establishment which requires an accurate measurement. There are many methods can be used to acquire height value such as tacheometry, leveling and Global Positioning System (GPS). This study has investigated the effect on height accuracy based on different observations which are single based and network based GPS methods. The GPS network is acquired from the local network namely Iskandar network. This network has been setup to provide real-time correction data to rover GPS station while the single network is based on the known GPS station. Nine ground control points were established evenly at the study area. Each ground control points were observed about two and ten minutes. It was found that, the height accuracy give the different result for each observation.

  12. The research on the effect of atmospheric transmittance for the measuring accuracy of infrared thermal imager

    Zhang, Yu-cun; Chen, Yi-ming; Fu, Xian-bin; Luo, Cheng

    2016-07-01

    The effect of atmospheric transmittance on infrared thermal imager temperature measuring accuracy cannot be ignored when the object is far from infrared thermal imager. In this paper, a method of reducing the influence of atmospheric transmittance is proposed for the infrared thermal imager. Firstly, the temperature measuring formula of infrared thermal imager and the effect of atmospheric transmittance on temperature measuring accuracy is analyzed. According to the composition of the atmosphere, the main factors influencing the atmosphere transmittance are determined. Secondly, the temperature measuring model of infrared thermal imager in sea level is established according to the absorption of water vapor and carbon dioxide, the scattering of air molecules and aerosol particulate, and the attenuation effects of weather conditions such as rain and snow. Finally, the correctness and feasibility of the proposed model is verified by the comparison experiments of four different environmental conditions. According to the experiments, the temperature measuring accuracy of the infrared thermal imager is improved.

  13. Evaluation of Relative Geometric Accuracy of Terrasar-X by Pixel Matching Methodology

    Nonaka, T.; Asaka, T.; Iwashita, K.

    2016-06-01

    Recently, high-resolution commercial SAR satellites with several meters of resolutions are widely utilized for various applications and disaster monitoring is one of the commonly applied areas. The information about the flooding situation and ground displacement was rapidly announced to the public after the Great East Japan Earthquake 2011. One of the studies reported the displacement in Tohoku region by the pixel matching methodology using both pre- and post- event TerraSAR-X data, and the validated accuracy was about 30 cm at the GEONET reference points. In order to discuss the spatial distribution of the displacement, we need to evaluate the relative accuracy of the displacement in addition to the absolute accuracy. In the previous studies, our study team evaluated the absolute 2D geo-location accuracy of the TerraSAR-X ortho-rectified EEC product for both flat and mountain areas. Therefore, the purpose of the current study was to evaluate the spatial and temporal relative geo-location accuracies of the product by considering the displacement of the fixed point as the relative geo-location accuracy. Firstly, by utilizing TerraSAR-X StripMap dataset, the pixel matching method for estimating the displacement with sub-pixel level was developed. Secondly, the validity of the method was confirmed by comparing with GEONET data. We confirmed that the accuracy of the displacement for X and Y direction was in agreement with the previous studies. Subsequently, the methodology was applied to 20 pairs of data set for areas of Tokyo Ota-ku and Kawasaki-shi, and the displacement of each pair was evaluated. It was revealed that the time series displacement rate had the seasonal trend and seemed to be related to atmospheric delay.

  14. HOMEWORK ACCURACY TO INCREASE THE ACADEMIC REPERTOIRE OF YOUNG CHILDREN WITH AUTISM

    Lina GILIC

    2016-04-01

    Full Text Available There are many forms of interventions used to increase homework completion. However, there is far less research to assess homework accuracy for young children with special needs, and even less for young children diagnosed with Autism. Homework intervention methods have been proven by researchers to be effective under certain specific circumstances. Emphasis should be placed on increasing the accuracy of homework completed prior to deciding what intervention would be more effective for a particular student struggling with homework completion. Educators should take into consideration the level of participation from the children’s home, the needs of the student, and how data would be collected and communicated for homework accuracy. Data for visual analysis would identify the homework completed correctly rather than just completed, and also identify progress over time. Researchers have demonstrated that homework completed cannot determine academic skill gained which is needed for academic success for young students with or without disabilities. Homework accuracy requires greater attention and emphasis in the early childhood research. The need for research on young children with Autism is evident as it is the fastest growing neurobiological condition in the world. The inclusion of children with Autism in the general environment has also greatly increased. Recommendations for further research focused on homework accuracy are offered.

  15. Influence of scanning strategies on the accuracy of digital intraoral scanning systems.

    Ender, A; Mehl, A

    2013-01-01

    The digital intraoral impression is a central part in today's CAD/CAM dentistry. With its possibilities, new treatment options for the patient is provided and the prosthetic workflow is accelerated. Nowadays, the major issue with intraoral scanning systems is to gain more accuracy especially for larger scan areas and to simplify clinical handling for the dentist. The aim of this study was to investigate different scanning strategies regardingtheir accuracy with full arch scans in an in-vitro study design. A reference master model was used for the digital impressions with the Lava COS, the Cerec Bluecam and a powderfree intraoral scanning system, Cadent iTero. The trueness and precision of each scanning protocol was measured. Lava COS provides the a trueness of 45.8 microm with the scanning protocol recommended from the manufacturer. A different scanning protocol shows significantly lower accuracy (trueness +/- 90.2 microm). Cerec Bluecam also benefits from an optimal scanning protocol with a trueness of +/- 23.3 microm compared to +/- 52.5 microm with a standard protocol. The powderfree impression system Cadent iTero shows also a high accurate full-arch scan with a trueness of +/- 35.0 microm and a precision of +/- 30.9 microm. With the current intraoral scanning systems, full arch dental impressions are possible with a high accuracy, if adequate scan strategies are used. The powderfree scanning system provides the same level of accuracy compared to scanning systems with surface pretreatment. PMID:23641661

  16. THE EFFECTS OF APPROACH ANGLE ON PENALTY KICKING ACCURACY AND KICK KINEMATICS WITH RECREATIONAL SOCCER PLAYERS

    Joanna Scurr

    2009-06-01

    Full Text Available Kicking accuracy is an important component of successful penalty kicks, which may be influenced by the approach angle. The purpose of this study was to examine the effects of approach angle on kicking accuracy and three-dimensional kinematics of penalty kicks. Seven male amateur recreational soccer players aged (mean ± s 26 ± 3 years, body mass 74.0 ± 6.8 kg, stature 1.74 ± 0.06 m, who were right foot dominant, kicked penalties at a 0.6 x 0.6 m target in a full size goal from their self-selected approach angle, 30º, 45º and 60º (direction of the kick was 0º. Kicking accuracy and three-dimensional kinematics were recorded. Results revealed that there was no significant difference in kicking accuracy (p = 0.27 or ball velocity (p = 0.59 between the approach angles. Pelvic rotation was significantly greater under the 45º and the 60º approach angles than during the self-selected approach angle (p < 0.05. Thigh abduction of the kicking leg at impact using the 60º approach angle was significantly greater than during the self- selected approach (p = 0.01 and the 30º approach (p = 0.04. It was concluded that altering an individual's self-selected approach angle at recreational level did not improve kicking accuracy or ball velocity, despite altering aspects of underlying technique.

  17. The diagnostic accuracy of multiparametric MRI to determine pediatric brain tumor grades and types.

    Koob, Mériam; Girard, Nadine; Ghattas, Badih; Fellah, Slim; Confort-Gouny, Sylviane; Figarella-Branger, Dominique; Scavarda, Didier

    2016-04-01

    Childhood brain tumors show great histological variability. The goal of this retrospective study was to assess the diagnostic accuracy of multimodal MR imaging (diffusion, perfusion, MR spectroscopy) in the distinction of pediatric brain tumor grades and types. Seventy-six patients (range 1 month to 18 years) with brain tumors underwent multimodal MR imaging. Tumors were categorized by grade (I-IV) and by histological type (A-H). Multivariate statistical analysis was performed to evaluate the diagnostic accuracy of single and combined MR modalities, and of single imaging parameters to distinguish the different groups. The highest diagnostic accuracy for tumor grading was obtained with diffusion-perfusion (73.24 %) and for tumor typing with diffusion-perfusion-MR spectroscopy (55.76 %). The best diagnostic accuracy was obtained for tumor grading in I and IV and for tumor typing in embryonal tumor and pilocytic astrocytoma. Poor accuracy was seen in other grades and types. ADC and rADC were the best parameters for tumor grading and typing followed by choline level with an intermediate echo time, CBV for grading and Tmax for typing. Multiparametric MR imaging can be accurate in determining tumor grades (primarily grades I and IV) and types (mainly pilocytic astrocytomas and embryonal tumors) in children. PMID:26732081

  18. Concept Mapping Improves Metacomprehension Accuracy among 7th Graders

    Redford, Joshua S.; Thiede, Keith W.; Wiley, Jennifer; Griffin, Thomas D.

    2012-01-01

    Two experiments explored concept map construction as a useful intervention to improve metacomprehension accuracy among 7th grade students. In the first experiment, metacomprehension was marginally better for a concept mapping group than for a rereading group. In the second experiment, metacomprehension accuracy was significantly greater for a…

  19. The neural basis of the speed-accuracy tradeoff

    R. Bogacz; E.J. Wagenmakers; B.U. Forstmann; S. Nieuwenhuis

    2010-01-01

    In many situations, decision makers need to negotiate between the competing demands of response speed and response accuracy, a dilemma generally known as the speed-accuracy tradeoff (SAT). Despite the ubiquity of SAT, the question of how neural decision circuits implement SAT has received little att

  20. The accuracy of CT - determined femoral neck anteversion

    In order to establish the accuracy of CT determination of femoral neck anteversion, two models were constructed; one an idealized Plexiglas model and the other from a real femur. Experiments were carried out by pre-setting angles on the phantoms, and then determining these angles by CT. The results, which show a high degree of accuracy, are analyzed statistically. (orig.)

  1. Aggregate Accuracy under Majority Rule with Heterogeneous Cost Functions

    Minoru Kitahara; Yohei Sekiguchi

    2006-01-01

    We investigate an election model with costly accuracy improvement by allowing heterogeneity in the cost functions. We find that the aggregate accuracy in large elections is characterized by the average value of the inverse of the second derivative at zero information.

  2. DESIGNA ND ANALYSIS FOR THEMATIC MAP ACCURACY ASSESSMENT: FUNDAMENTAL PRINCIPLES

    Before being used in scientific investigations and policy decisions, thematic maps constructed from remotely sensed data should be subjected to a statistically rigorous accuracy assessment. The three basic components of an accuracy assessment are: 1) the sampling design used to s...

  3. Using inferred probabilities to measure the accuracy of imprecise forecasts

    Paul Lehner

    2012-11-01

    Full Text Available Research on forecasting is effectively limited to forecasts that are expressed with clarity; which is to say that the forecasted event must be sufficiently well-defined so that it can be clearly resolved whether or not the event occurred and forecasts certainties are expressed as quantitative probabilities. When forecasts are expressed with clarity, then quantitative measures (scoring rules, calibration, discrimination, etc. can be used to measure forecast accuracy, which in turn can be used to measure the comparative accuracy of different forecasting methods. Unfortunately most real world forecasts are not expressed clearly. This lack of clarity extends to both the description of the forecast event and to the use of vague language to express forecast certainty. It is thus difficult to assess the accuracy of most real world forecasts, and consequently the accuracy the methods used to generate real world forecasts. This paper addresses this deficiency by presenting an approach to measuring the accuracy of imprecise real world forecasts using the same quantitative metrics routinely used to measure the accuracy of well-defined forecasts. To demonstrate applicability, the Inferred Probability Method is applied to measure the accuracy of forecasts in fourteen documents examining complex political domains. Key words: inferred probability, imputed probability, judgment-based forecasting, forecast accuracy, imprecise forecasts, political forecasting, verbal probability, probability calibration.

  4. 40 CFR 86.1338-2007 - Emission measurement accuracy.

    2010-07-01

    ... 40 Protection of Environment 19 2010-07-01 2010-07-01 false Emission measurement accuracy. 86.1338... Procedures § 86.1338-2007 Emission measurement accuracy. (a) Minimum limit. (1) The minimum limit of an... it will allow a meaningful determination of compliance with respect to the applicable standard....

  5. Follow your breath: Respiratory interoceptive accuracy in experienced meditators

    Daubenmier, J; Sze, J.; Kerr, CE; Kemeny, ME; Mehling, W

    2013-01-01

    Attention to internal bodily sensations is a core feature of mindfulness meditation. Previous studies have not detected differences in interoceptive accuracy between meditators and nonmeditators on heartbeat detection and perception tasks. We compared differences in respiratory interoceptive accuracy between meditators and nonmeditators in the ability to detect and discriminate respiratory resistive loads and sustain accurate perception of respiratory tidal volume during nondistracted and dis...

  6. High accuracy mantle convection simulation through modern numerical methods

    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.

  7. Perceptual Load Affects Eyewitness Accuracy and Susceptibility to Leading Questions.

    Murphy, Gillian; Greene, Ciara M

    2016-01-01

    Load Theory (Lavie, 1995, 2005) states that the level of perceptual load in a task (i.e., the amount of information involved in processing task-relevant stimuli) determines the efficiency of selective attention. There is evidence that perceptual load affects distractor processing, with increased inattentional blindness under high load. Given that high load can result in individuals failing to report seeing obvious objects, it is conceivable that load may also impair memory for the scene. The current study is the first to assess the effect of perceptual load on eyewitness memory. Across three experiments (two video-based and one in a driving simulator), the effect of perceptual load on eyewitness memory was assessed. The results showed that eyewitnesses were less accurate under high load, in particular for peripheral details. For example, memory for the central character in the video was not affected by load but memory for a witness who passed by the window at the edge of the scene was significantly worse under high load. High load memories were also more open to suggestion, showing increased susceptibility to leading questions. High visual perceptual load also affected recall for auditory information, illustrating a possible cross-modal perceptual load effect on memory accuracy. These results have implications for eyewitness memory researchers and forensic professionals. PMID:27625628

  8. Accuracy of 11-year-olds selfreported school lunch consumption

    Lyng, Nina

    studies among children has addressed accuracy in relation to school meals. However, in several countries including Denmark packed lunch is the prevalent lunch format and the lack of packed lunch reporting accuracy studies needs to be addressed to increase the knowledge about school hour reporting accuracy......) 2- To assess reporting accuracy in relation to gender and self-reported methods (Paper I) 3- To address aspects of reporting inaccuracy from intrusions by food group, against different objective measures, and classification of intrusions in stretches and confabulations (Paper II) 4- To assess how...... reporting accuracy differ by the lunch format consumed (Paper III) Material and methods The study was conducted as a cross-sectional dietary reporting study. The population consisted of 11-year-old children from three public schools in Copenhagen. The study was conducted on two consecutive days and assessed...

  9. Testing an Automated Accuracy Assessment Method on Bibliographic Data

    Marlies Olensky

    2014-12-01

    Full Text Available This study investigates automated data accuracy assessment as described in data quality literature for its suitability to assess bibliographic data. The data samples comprise the publications of two Nobel Prize winners in the field of Chemistry for a 10-year-publication period retrieved from the two bibliometric data sources, Web of Science and Scopus. The bibliographic records are assessed against the original publication (gold standard and an automatic assessment method is compared to a manual one. The results show that the manual assessment method reflects truer accuracy scores. The automated assessment method would need to be extended by additional rules that reflect specific characteristics of bibliographic data. Both data sources had higher accuracy scores per field than accumulated per record. This study contributes to the research on finding a standardized assessment method of bibliographic data accuracy as well as defining the impact of data accuracy on the citation matching process.

  10. Application of function generator for checking reactivity meter accuracy

    The accuracy of reactivity meters is usually checked with a reactor kinetic simulator operating to an accuracy exceeding the expected accuracy of the measuring device. The present report describes a method to evaluate accuracy by comparing the response R(t) of the reactivity meter to a given function n(t) with the value of the reactivity function r(t) calculated from the same input function instead of using the input reference signal r(t) to the simulator with the output signal R(t) from the reactivity meter. This method has been successfully used by applying sawtooth and exponential input signals for the determination of the accuracy of reactivity meters developed in the Central Research Institute for Physics. (author)

  11. ENHANCE THE ACCURACY OF THE DISTANCE OF DISTANCE MEASURING CHANNEL OF THE OBSERVATION DEVICE USING SEMICONDUCTOR LASER

    A. V. Fufaev

    2015-03-01

    Full Text Available A method for improving the accuracy rangefinder with a semiconductor laser operating in the mode of accumulation of weak reflected signals at multiple sensing target, is described. It is shown that the use of in receiving channel of rangefinder two threshold electric drive with automatic adjustment of levels, can improve the signal/noise ratio and improve the accuracy of measurements. The results of laboratory and field tests distance measuring channel observation device are given.

  12. Accuracy of Coverage Survey Recall following an Integrated Mass Drug Administration for Lymphatic Filariasis, Schistosomiasis, and Soil-Transmitted Helminthiasis

    Budge, Philip J.; Edmond Sognikin; Amanda Akosa; Mathieu, Els M.; Michael Deming

    2016-01-01

    Background Achieving target coverage levels for mass drug administration (MDA) is essential to elimination and control efforts for several neglected tropical diseases (NTD). To ensure program goals are met, coverage reported by drug distributors may be validated through household coverage surveys that rely on respondent recall. This is the first study to assess accuracy in such surveys. Methodology/Principal Findings Recall accuracy was tested in a series of coverage surveys conducted at 1, 6...

  13. Computational Design of Self-Assembling Protein Nanomaterials with Atomic Level Accuracy

    King, Neil P.; Sheffler, William; Sawaya, Michael R.; Vollmar, Breanna S.; Sumida, John P.; André, Ingemar; Gonen, Tamir; Yeates, Todd O.; Baker, David (UWASH); (UCLA); (HHMI); (Lund)

    2015-09-17

    We describe a general computational method for designing proteins that self-assemble to a desired symmetric architecture. Protein building blocks are docked together symmetrically to identify complementary packing arrangements, and low-energy protein-protein interfaces are then designed between the building blocks in order to drive self-assembly. We used trimeric protein building blocks to design a 24-subunit, 13-nm diameter complex with octahedral symmetry and a 12-subunit, 11-nm diameter complex with tetrahedral symmetry. The designed proteins assembled to the desired oligomeric states in solution, and the crystal structures of the complexes revealed that the resulting materials closely match the design models. The method can be used to design a wide variety of self-assembling protein nanomaterials.

  14. Influence of scanning system and dentist's level of training in the accuracy of digital impressions

    Hategan, Simona; Gabor, Alin; Zaharia, Cristian; Sinescu, Cosmin; Negrutiu, Meda Lavinia; Jivanescu, Anca

    2016-03-01

    Background: The principal aim of our study was to evaluate digital impressions, taken with spray powder and powderfree scan systems, in order to determine the influence of the dentist's commitment to training as a critical factor regarding quality. Material and method: Two digital intraoral impression systems from the same manufacture (Sirona) : Apollo DI and CEREC Omnicam, were used to scan 16 crown preparations on teeth on a typodont maxillary model. Because an Apollo Di intraoral camera is a powder system, an adhesive was applied before using the powder spray. Three groups were used to scan the crown preparations in order to determine coating thickness homogeneity. One group consisted of senior year dental students, a second consisted of prosthodontics residents, and the third consisted of prosthodontics specialists. The same procedure was applied with a CEREC Omnicam intraoral camera, which is a powder-free system. By using the two systems software parameters we were able to determine the scanning precision. Results: Homogeneity scores for Apollo Di regarding the spray layer was significantly thinner for all dental surfaces in the first group, while the second group had thinner coatings for buccal and distal surfaces. For the third group, the crown preparations were coated more homogeneously than the first two groups. The powder-free system CEREC Omnicam can, to a degree, mask the lack of experience in direct optical impressions by avoiding the poor quality coating, which can lead to defective marginal adaptation of definitive restoration. Conclusions: The dentist's lack of experience can be mitigated, and partially avoided, by using powder-free systems. At the same time, the dentist can give more time towards learning how to integrate computerized fabricated restoration into the practice. The commitment to training is a critical factor in the successful integration of the technology. In addition, scanning marginal preparation details needs time in order to develop technical and manual skills.

  15. Energy Measurement with the ATLAS Electromagnetic Calorimeter at the Per Mill Accuracy Level

    Teischinger, Florian; Fabjan, Christian

    The ATLAS experiment is designed to study the proton-proton collisions produced at the Large Hadron Collider (LHC) at CERN. It is made up of various sub-detectors to measure the properties of all the particles produced at the proton-proton collision. Over the last three years of running around 20 x 10^14 collisions of proton data have been recorded. Liquid argon (LAr) sampling calorimeters are used for all electromagnetic calorimetry and for hadronic calorimetry in the end-caps. The Inner Detector, on the other hand, measures the transverse momentum of charged particles down to a momentum of 0.5 GeV. This thesis deals with the absolute measurement of the energy in the electromagnetic calorimeter and the improvement of the systematic uncertainties. A method using the ratio of the energy E in the calorimeter and the momentum measurement p in the Inner Detector (E/p) was used to extract the energy scale of the electromagnetic LAr calorimeter for electrons and positrons. To investigate and further reduce the syst...

  16. To measure wear level with accuracy, velocity and at lower price

    Thin layer activation (TLA) is a non-destructive method to follow unceasingly the loss of matter from the surface of any mechanical component. This technique involves 3 steps: - the activation of the component which requires proton or deuteron beams produced by a particle accelerator, - the setting of the component in its current operating surroundings, and - the measurement of the emitted γ radiation, the output signal is linked to the matter loss. 2 kinds of measurements are possible. Direct measurement where a sensor is placed near the component and measures the evolution of the γ radiation. Concentration measurement where a sensor measures the γ radiation emitted by the scraps of corrosion or wearing taken away by lubricating or cooling liquids. TLA is used in motor industry, precision engineering, it allows the acceleration of the development of new products by shortening testing time. TLA can also make easier the maintenance of industrial equipment. (A.C.)

  17. Recommended aerobic fitness level for metabolic health in children and adolescents: a study of diagnostic accuracy

    Adegboye, Amanda Ra; Anderssen, Sigmund A; Froberg, Karsten;

    2011-01-01

    systolic blood pressure, triglyceride, total cholesterol/HDL-cholesterol ratio, insulin resistance and sum of four skinfolds. 14.5% of the sample, with a risk score above one SD, were defined as being at risk. Receiver operating characteristic analysis was used to define the optimal cut-off for sex and age...

  18. Accuracy of endoscopic ultrasonography for diagnosing ulcerative early gastric cancers.

    Park, Jin-Seok; Kim, Hyungkil; Bang, Byongwook; Kwon, Kyesook; Shin, Youngwoon

    2016-07-01

    Although endoscopic ultrasonography (EUS) is the first-choice imaging modality for predicting the invasion depth of early gastric cancer (EGC), the prediction accuracy of EUS is significantly decreased when EGC is combined with ulceration.The aim of present study was to compare the accuracy of EUS and conventional endoscopy (CE) for determining the depth of EGC. In addition, the various clinic-pathologic factors affecting the diagnostic accuracy of EUS, with a particular focus on endoscopic ulcer shapes, were evaluated.We retrospectively reviewed data from 236 consecutive patients with ulcerative EGC. All patients underwent EUS for estimating tumor invasion depth, followed by either curative surgery or endoscopic treatment. The diagnostic accuracy of EUS and CE was evaluated by comparing the final histologic result of resected specimen. The correlation between accuracy of EUS and characteristics of EGC (tumor size, histology, location in stomach, tumor invasion depth, and endoscopic ulcer shapes) was analyzed. Endoscopic ulcer shapes were classified into 3 groups: definite ulcer, superficial ulcer, and ill-defined ulcer.The overall accuracy of EUS and CE for predicting the invasion depth in ulcerative EGC was 68.6% and 55.5%, respectively. Of the 236 patients, 36 patients were classified as definite ulcers, 98 were superficial ulcers, and 102 were ill-defined ulcers, In univariate analysis, EUS accuracy was associated with invasion depth (P = 0.023), tumor size (P = 0.034), and endoscopic ulcer shapes (P = 0.001). In multivariate analysis, there is a significant association between superficial ulcer in CE and EUS accuracy (odds ratio: 2.977; 95% confidence interval: 1.255-7.064; P = 0.013).The accuracy of EUS for determining tumor invasion depth in ulcerative EGC was superior to that of CE. In addition, ulcer shape was an important factor that affected EUS accuracy. PMID:27472672

  19. How does language model size effects speech recognition accuracy for the Turkish language?

    Behnam ASEFİSARAY

    2016-05-01

    Full Text Available In this paper we aimed at investigating the effect of Language Model (LM size on Speech Recognition (SR accuracy. We also provided details of our approach for obtaining the LM for Turkish. Since LM is obtained by statistical processing of raw text, we expect that by increasing the size of available data for training the LM, SR accuracy will improve. Since this study is based on recognition of Turkish, which is a highly agglutinative language, it is important to find out the appropriate size for the training data. The minimum required data size is expected to be much higher than the data needed to train a language model for a language with low level of agglutination such as English. In the experiments we also tried to adjust the Language Model Weight (LMW and Active Token Count (ATC parameters of LM as these are expected to be different for a highly agglutinative language. We showed that by increasing the training data size to an appropriate level, the recognition accuracy improved on the other hand changes on LMW and ATC did not have a positive effect on Turkish speech recognition accuracy.

  20. 40 CFR 53.53 - Test for flow rate accuracy, regulation, measurement accuracy, and cut-off.

    2010-07-01

    ... the sampler such that the sampler flow rate can be manually restricted during the test. (f) Procedure... 40 Protection of Environment 5 2010-07-01 2010-07-01 false Test for flow rate accuracy, regulation... Class II Equivalent Methods for PM2.5 or PM10â2.5 § 53.53 Test for flow rate accuracy,...

  1. Evaluation of precision and accuracy of selenium measurements in biological materials using neutron activation analysis

    In recent years, the accurate determination of selenium in biological materials has become increasingly important in view of the essential nature of this element for human nutrition and its possible role as a protective agent against cancer. Unfortunately, the accurate determination of selenium in biological materials is often difficult for most analytical techniques for a variety of reasons, including interferences, complicated selenium chemistry due to the presence of this element in multiple oxidation states and in a variety of different organic species, stability and resistance to destruction of some of these organo-selenium species during acid dissolution, volatility of some selenium compounds, and potential for contamination. Neutron activation analysis (NAA) can be one of the best analytical techniques for selenium determinations in biological materials for a number of reasons. Currently, precision at the 1% level (1s) and overall accuracy at the 1 to 2% level (95% confidence interval) can be attained at the U.S. National Bureau of Standards (NBS) for selenium determinations in biological materials when counting statistics are not limiting (using the 75Se isotope). An example of this level of precision and accuracy is summarized. Achieving this level of accuracy, however, requires strict attention to all sources of systematic error. Precise and accurate results can also be obtained after radiochemical separations

  2. Accuracy of blood pressure monitors available in high street pharmacies.

    Ware, Adam; Stevens, Richard; Selwood, Mary; Fleming, Susannah

    2016-02-01

    The aim of this study was to assess the accuracy of automated blood pressure monitors on sale to the UK general public. We conducted static pressure accuracy testing on all compatible (19 out of 22 available) blood pressure monitors available for sale in pharmacies within the city of Oxford, UK, and tested two devices for accuracy in measurement of systolic and diastolic blood pressures in 21 adults. The devices showed good accuracy when measuring static pressure in laboratory bench testing, with the median error per device ranging from -2.2 to +1.2 mmHg; however, the two devices tested performed worse in vivo than in laboratory tests, with median errors as high as 6 mmHg. The monitors showed good accuracy in static pressure testing, with a lack of correlation between monitor price and accuracy. However, higher error rates seen during in-vivo testing of a subset of monitors may indicate that static testing may not be appropriate for routine accuracy assessment of these monitors. PMID:26427055

  3. Liquid level sensor

    The article reports an idea of using a simple, cantilever-type load cell with a rod as a level sensor for continuous liquid level measurements. The sensor is based on the principle of the Archimedes buoyancy principle. The density and geometry of the rod govern the choice of the load cell. The length of the rod is governed by the height of the tank. A series of cyclic tests have demonstrated a highly repeatable response of the sensor. The accuracy of this low-cost sensor is field tested and found to be ±0.5% of the full range, for a 10 m level of water in a tank, and is working reliably for the period of 18 months. The sensor range can be easily extended to lower and higher tank heights. The sensor is crowned by its easy installation and calibration

  4. Accuracy of spinal navigation for Magerl-screws

    Study design: assessment of the accuracy of frameless stereotactic navigation at the second cervical vertebra. Objectives: to assess the influence of the protocol of preoperative CT-scan and the registration technique on the accuracy of navigation for implanting Magerl-screws. Summary of background data: the use of navigation systems for implanting Magerl-screws could help to decrease the risk of complications and to reduce the required skin incision. Two parameters conceivably affecting the accuracy are the protocol of the preoperative CT-scan and the registration technique. Methods: four cervical spine segments of human cadavers were scanned with two different protocols (3 mm slice thickness/2 mm table increment, 1 mm slice thickness/1 mm table increment). Registration was performed either based on anatomical landmarks or using a specially designed percutaneous registration device. For the accuracy-check, the pointer tip was exactly placed on markers. The distance between the pointer and the marker displayed on the monitor was referred as an estimate of accuracy. Results: varying the CT-protocol did not significantly affect the accuracy. The mean accuracy was improved from 3 mm after anatomical pair point matching to 1.5 mm after matching using the percutaneous registration device. Conclusions: the accuracy obtainable seems to be sufficient for implanting Magerl screws by using frameless stereotactic navigation. 3 mm slice thickness and 2 mm table increment is a proper protocol for the preoperative CT-scan. To obtain the highest accuracy possible, fiducial markers like the percutaneous registration device should be used for registration. (author)

  5. Accuracy of Genomic Selection in a Rice Synthetic Population Developed for Recurrent Selection Breeding.

    Grenier, Cécile; Cao, Tuong-Vi; Ospina, Yolima; Quintero, Constanza; Châtel, Marc Henri; Tohme, Joe; Courtois, Brigitte; Ahmadi, Nourollah

    2015-01-01

    Genomic selection (GS) is a promising strategy for enhancing genetic gain. We investigated the accuracy of genomic estimated breeding values (GEBV) in four inter-related synthetic populations that underwent several cycles of recurrent selection in an upland rice-breeding program. A total of 343 S2:4 lines extracted from those populations were phenotyped for flowering time, plant height, grain yield and panicle weight, and genotyped with an average density of one marker per 44.8 kb. The relative effect of the linkage disequilibrium (LD) and minor allele frequency (MAF) thresholds for selecting markers, the relative size of the training population (TP) and of the validation population (VP), the selected trait and the genomic prediction models (frequentist and Bayesian) on the accuracy of GEBVs was investigated in 540 cross validation experiments with 100 replicates. The effect of kinship between the training and validation populations was tested in an additional set of 840 cross validation experiments with a single genomic prediction model. LD was high (average r2 = 0.59 at 25 kb) and decreased slowly, distribution of allele frequencies at individual loci was markedly skewed toward unbalanced frequencies (MAF average value 15.2% and median 9.6%), and differentiation between the four synthetic populations was low (FST ≤0.06). The accuracy of GEBV across all cross validation experiments ranged from 0.12 to 0.54 with an average of 0.30. Significant differences in accuracy were observed among the different levels of each factor investigated. Phenotypic traits had the biggest effect, and the size of the incidence matrix had the smallest. Significant first degree interaction was observed for GEBV accuracy between traits and all the other factors studied, and between prediction models and LD, MAF and composition of the TP. The potential of GS to accelerate genetic gain and breeding options to increase the accuracy of predictions are discussed. PMID:26313446

  6. Accuracy of Genomic Selection in a Rice Synthetic Population Developed for Recurrent Selection Breeding.

    Cécile Grenier

    Full Text Available Genomic selection (GS is a promising strategy for enhancing genetic gain. We investigated the accuracy of genomic estimated breeding values (GEBV in four inter-related synthetic populations that underwent several cycles of recurrent selection in an upland rice-breeding program. A total of 343 S2:4 lines extracted from those populations were phenotyped for flowering time, plant height, grain yield and panicle weight, and genotyped with an average density of one marker per 44.8 kb. The relative effect of the linkage disequilibrium (LD and minor allele frequency (MAF thresholds for selecting markers, the relative size of the training population (TP and of the validation population (VP, the selected trait and the genomic prediction models (frequentist and Bayesian on the accuracy of GEBVs was investigated in 540 cross validation experiments with 100 replicates. The effect of kinship between the training and validation populations was tested in an additional set of 840 cross validation experiments with a single genomic prediction model. LD was high (average r2 = 0.59 at 25 kb and decreased slowly, distribution of allele frequencies at individual loci was markedly skewed toward unbalanced frequencies (MAF average value 15.2% and median 9.6%, and differentiation between the four synthetic populations was low (FST ≤0.06. The accuracy of GEBV across all cross validation experiments ranged from 0.12 to 0.54 with an average of 0.30. Significant differences in accuracy were observed among the different levels of each factor investigated. Phenotypic traits had the biggest effect, and the size of the incidence matrix had the smallest. Significant first degree interaction was observed for GEBV accuracy between traits and all the other factors studied, and between prediction models and LD, MAF and composition of the TP. The potential of GS to accelerate genetic gain and breeding options to increase the accuracy of predictions are discussed.

  7. Accuracy and performance analysis of a nuclear belt weigher

    Nuclear belt weighers have a broad range of applications in the solid particle industry. This work analyzes the accuracy and sensitivity of nuclear weighers for a wide range of operational conditions and design parameters. The problem of the effect of material profile and bulk density variations on the scale performance is quantitatively addressed. A new methodology is developed to calculate the minimum detectable load accounting for both accuracy and sensitivity. Accuracies of less than 1% can be achieved in some ideal situations by proper design of the source length and geometrical configuration. (orig.)

  8. Art and accuracy: the drawing ability of idiot-savants.

    Hermelin, B; O'Connor, N

    1990-01-01

    The accuracy and the artistic merit of drawings produced by graphically gifted idiot-savants and by artistically able normal children were investigated in various conditions. Drawings had to be executed when a three- or two-dimensional model of the scene to be drawn was in view, or when it had to be remembered or drawn from another viewpoint. It was found that overall accuracy was better for the normal than for the mentally handicapped subjects. In contrast, ratings for artistic merit did not differentiate the groups. It is concluded that while the accuracy of drawings may be related to intelligence, the artistic quality of the graphic production is not. PMID:2312650

  9. Differences between experts and novices in kinematics and accuracy of golf putting.

    Sim, Mikyong; Kim, Jin-Uk

    2010-12-01

    In this study, golf-putting movements were examined under three goal distances (short, 1.7m; middle, 3.25m; long, 6m), two different putter weights (500g, 750g), and two levels of expertise (5 experts, 5 novices). The study's aim was to identify differences in kinematics and accuracy between expert and novice golfers. The results demonstrated that experts achieved higher accuracy with lower impact velocity than novices. In addition, while novices showed symmetrical movements, experts exhibited asymmetrical movements, which were achieved by modulating their movement time and amplitude differently from novices. These results demonstrated differences in relative timing, relative amplitude and velocity, but no difference in time-to-contact between novices and experts. The results reaffirmed the role of prior learning and supported the hypothesis of Manoel and Connolly (1995) that motor learning is a hierarchical process organized at both macroscopic and microscopic levels. PMID:20846738

  10. Using super-resolution images to improve the measurement accuracy of DIC

    Wang, Yueqi; Lava, Pascal; Debruyne, Dimitri

    2015-01-01

    DIC measurements highly depend on the intensity interpolation of images to achieve subpixel accuracies. The intensity interpolation at subpixel positions is based on the grey levels sampled at integer pixels. Therefore, the sampling rate is crucial to the interpolated intensities. The sampling rate is restricted by the camera resolution. With insufficient resolution, the interpolated intensities at subpixel positions evidently differ from the reality, and significantly degrade the measurement...

  11. Influence of the demand information quality on planning process accuracy in supply chain. Case studies

    Natalia Szozda; Sylwia Werbińska-Wojciechowska

    2013-01-01

    Background: Identification and analysis of factors that affect the accuracy of demand planning process across the supply chain is one of the most important problems which influence the effectiveness of its material and information flows. Material and methods: On the basis of demand planning process investigation authors define the main elements affecting the right supply chain performance level and investigate the possible connections between demand information quality and demand plannin...

  12. Eyewitness confidence: the relation between accuracy and confidence in episodic memory

    Odinot, Geralda

    2008-01-01

    Many decisions in the legal system are based on eyewitness evidence. It seems to be a matter of common sense that the level of confidence expressed by a witness can be used as a diagnostic tool to discriminate between accurate and inaccurate memories. Contrary to this general belief, the bulk of empirical evidence collected in laboratory and field experiments over the past 25 years indicates that the relationship between confidence and accuracy is far from perfect. The central focus of this d...

  13. Effect of Kinesiotape Applications on Ball Velocity and Accuracy in Amateur Soccer and Handball

    Müller Carsten; Brandes Mirko

    2015-01-01

    Evidence supporting performance enhancing effects of kinesiotape in sports is missing. The aims of this study were to evaluate effects of kinesiotape applications with regard to shooting and throwing performance in 26 amateur soccer and 32 handball players, and to further investigate if these effects were influenced by the players’ level of performance. Ball speed as the primary outcome and accuracy of soccer kicks and handball throws were analyzed with and without kinesiotape by means of rad...

  14. Enhancing accuracy of magnetic resonance image fusion by defining a volume of interest

    We compared the registration accuracy for corresponding anatomical landmarks in two MR images after fusing the complete volume (CV) and a defined volume of interest (VOI) of both MRI data sets. We carried out contrast-enhanced T1-weighted gradient-echo and T2-weighted fast spin-echo MRI (matrix 256 x 256) in 39 cases. The CV and a defined VOI data set were each fused using prototype software. We measured and analysed the distance between 25 anatomical landmarks in predefined areas identified at levels L1-L5 corresponding to defined axial sections. Fusion technique, landmark areas and level of fusion were further processed using a feed-forward neural network to calculate the difference which can be expected based on the measurements. We identified 975 landmarks for both T1- and T2-weighted images and found a significant difference in registration accuracy (P1) to caudal (L5), mean deviations were: L1 CV 1.5 mm, VOI 0.5 mm; L2 CV 1.8 mm, VOI 0.4 mm; L3 CV 1.7 mm, VOI 0.4 mm; L4 CV 1.6 mm, VOI 0.6 mm; and L5 CV 1.6 mm, VOI 1.6 mm. Neural network analysis predicted a higher accuracy for VOI (0.05-0.15 mm) than for CV fusion (0.9-1.6 mm). Deviations due to magnetic susceptibility changes between air and tissue seen on gradient-echo images can decrease fusion accuracy. Our VOI fusion technique improves image fusion accuracy to <0.5 mm by excluding areas with marked susceptibility changes. (orig.)

  15. Inertial measures of motion for clinical biomechanics: comparative assessment of accuracy under controlled conditions - changes in accuracy over time.

    Karina Lebel

    Full Text Available Interest in 3D inertial motion tracking devices (AHRS has been growing rapidly among the biomechanical community. Although the convenience of such tracking devices seems to open a whole new world of possibilities for evaluation in clinical biomechanics, its limitations haven't been extensively documented. The objectives of this study are: 1 to assess the change in absolute and relative accuracy of multiple units of 3 commercially available AHRS over time; and 2 to identify different sources of errors affecting AHRS accuracy and to document how they may affect the measurements over time.This study used an instrumented Gimbal table on which AHRS modules were carefully attached and put through a series of velocity-controlled sustained motions including 2 minutes motion trials (2MT and 12 minutes multiple dynamic phases motion trials (12MDP. Absolute accuracy was assessed by comparison of the AHRS orientation measurements to those of an optical gold standard. Relative accuracy was evaluated using the variation in relative orientation between modules during the trials.Both absolute and relative accuracy decreased over time during 2MT. 12MDP trials showed a significant decrease in accuracy over multiple phases, but accuracy could be enhanced significantly by resetting the reference point and/or compensating for initial Inertial frame estimation reference for each phase.The variation in AHRS accuracy observed between the different systems and with time can be attributed in part to the dynamic estimation error, but also and foremost, to the ability of AHRS units to locate the same Inertial frame.Mean accuracies obtained under the Gimbal table sustained conditions of motion suggest that AHRS are promising tools for clinical mobility assessment under constrained conditions of use. However, improvement in magnetic compensation and alignment between AHRS modules are desirable in order for AHRS to reach their full potential in capturing clinical outcomes.

  16. Effective Analysis of Chinese Word-Segmentation Accuracy

    MA Weiyin

    2007-01-01

    Automatic word-segmentation is widely used in the ambiguity cancellation when processing large-scale real text,but during the process of unknown word detection in Chinese word segmentation,many detected word candidates are invalid.These false unknown word candidates deteriorate the overall segmentation accuracy,as it will affect the segmentation accuracy of known words.In this paper,we propose several methods for reducing the difficulties and improving the accuracy of the word-segmentation of written Chinese,such as full segmentation of a sentence,processing the duplicative word,idioms and statistical identification for unknown words.A simulation shows the feasibility of our proposed methods in improving the accuracy of word-segmentation of Chinese.

  17. Accuracy Assessment Points for Petersburg National Battlefield Vegetation Mapping Project

    National Park Service, Department of the Interior — This shapefile depicts the locations of thematic accuracy assessment sampling points used in the vegetation mapping of Petersburg National Battlefield. It was...

  18. Examination of the Accuracy of Coding Hospital-Acquired...

    U.S. Department of Health & Human Services — A new study, Examination of the Accuracy of Coding Hospital-Acquired Pressure Ulcer Stages, published in Volume 4, Issue 1 of the Medicare and Medicaid Research...

  19. Accuracy Assessment Points for Dinosaur National Monument Vegetation Mapping Project

    National Park Service, Department of the Interior — This point file displays the 1543 accuracy assessment (AA) points visited in the summer of 2005 as part of the vegetation mapping project. The points were randomly...

  20. #DDOD Use Case: Accuracy of healthcare.gov Plan Finder

    U.S. Department of Health & Human Services — SUMMARY DDOD use case to verify the accuracy of data obtained from the HealthCare Finder API after a user identified potential data quality issues. WHAT IS A USE...

  1. Accuracy of spinal navigation for Magerl-screws

    Herz, T

    2001-01-01

    Study design: assessment of the accuracy of frameless stereotactic navigation at the second cervical vertebra. Objectives: to assess the influence of the protocol of preoperative CT-scan and the registration technique on the accuracy of navigation for implanting Magerl-screws. Summary of background data: the use of navigation systems for implanting Magerl-screws could help to decrease the risk of complications and to reduce the required skin incision. Two parameters conceivably affecting the accuracy are the protocol of the preoperative CT-scan and the registration technique. Methods: four cervical spine segments of human cadavers were scanned with two different protocols (3 mm slice thickness/2 mm table increment, 1 mm slice thickness/1 mm table increment). Registration was performed either based on anatomical landmarks or using a specially designed percutaneous registration device. For the accuracy-check, the pointer tip was exactly placed on markers. The distance between the pointer and the marker displaye...

  2. A Novel Navigation Robustness and Accuracy Improvement System Project

    National Aeronautics and Space Administration — To address NASA's need for L1 C/A-based navigation with better anti-spoofing ability and higher accuracy, Broadata Communications, Inc. (BCI) proposes to develop a...

  3. Accuracy of depth of cut in micro milling operations

    Bissacco, Giuliano

    downscaling of conventional manufacturing technologies. Although in micro manufacturing operations particular precautions are taken, the ratio between tolerances and absolute dimensions increases. However, the absolute required accuracy for the functionality increases, therefore the absolute value of...

  4. Accuracy Assessment Points for Badlands National Park Vegetation Mapping Project

    National Park Service, Department of the Interior — This metadata is for the accuracy assessment data associated with the vegetation land cover and land use geospatial database for Badlands National Park and...

  5. Accuracy evaluation of pendulum gravity measurements of Robert von Sterneck

    Alena Pešková

    2015-06-01

    Full Text Available The accuracy of first pendulum gravity measurements in the Czech territory was determined using both original surveying notebooks of Robert Daublebsky von Sterneck and modern technologies. Since more accurate methods are used for gravity measurements nowadays, our work is mostly important from the historical point of view. In previous  works, the accuracy of Sterneck’s gravity measurements was determined using only a small dataset. Here we process all Sterneck’s measurements from the Czech territory (a dataset ten times larger than in the previous works, and we complexly assess the accuracy of these measurements. Locations of the measurements were found with the help of original notebooks. Gravity in the site was interpolated using actual gravity models. Finally, the accuracy of Sterneck’s measurements was evaluated as the difference between the measured and interpolated gravity.

  6. Accelerating scientific codes by performance and accuracy modeling

    Fabregat-Traver, Diego; Bientinesi, Paolo

    2016-01-01

    Scientific software is often driven by multiple parameters that affect both accuracy and performance. Since finding the optimal configuration of these parameters is a highly complex task, it extremely common that the software is used suboptimally. In a typical scenario, accuracy requirements are imposed, and attained through suboptimal performance. In this paper, we present a methodology for the automatic selection of parameters for simulation codes, and a corresponding prototype tool. To be amenable to our methodology, the target code must expose the parameters affecting accuracy and performance, and there must be formulas available for error bounds and computational complexity of the underlying methods. As a case study, we consider the particle-particle particle-mesh method (PPPM) from the LAMMPS suite for molecular dynamics, and use our tool to identify configurations of the input parameters that achieve a given accuracy in the shortest execution time. When compared with the configurations suggested by exp...

  7. Parenting and adolescents' accuracy in perceiving parental values.

    Knafo, Ariel; Schwartz, Shalom H

    2003-01-01

    What determines adolescents' accuracy in perceiving parental values? The current study examined potential predictors including parental value communication, family value agreement, and parenting styles. In the study, 547 Israeli adolescents (aged 16 to 18) of diverse socioeconomic backgrounds participated with their parents. Adolescents reported the values they perceive their parents want them to hold. Parents reported their socialization values. Accuracy in perceiving parents' overall value system correlated positively with parents' actual and perceived value agreement and perceived parental warmth and responsiveness, but negatively with perceived value conflict, indifferent parenting, and autocratic parenting in all gender compositions of parent-child dyads. Other associations varied by dyad type. Findings were similar for predicting accuracy in perceiving two specific values: tradition and hedonism. The article discusses implications for the processes that underlie accurate perception, gender differences, and other potential influences on accuracy in value perception. PMID:12705575

  8. Accuracy Assessment Points for Colorado National Monument Vegetation Mapping Project

    National Park Service, Department of the Interior — This point file displays the 500 accuracy assessment (AA) points visited in July and August of 2004 as part of the vegetation mapping project. Five hundred and one...

  9. Accuracy Assessment Points for Wupatki National Monument Vegetation Mapping Project

    National Park Service, Department of the Interior — This spatial dataset in ESRI Coverage format maps accuracy assessment point locations for the vegetation map at Wupatki National Monument and in the surrounding...

  10. Error Estimation and Accuracy Improvements in Nodal Transport Methods

    The accuracy of the solutions produced by the Discrete Ordinates neutron transport nodal methods is analyzed.The obtained new numerical methodologies increase the accuracy of the analyzed scheems and give a POSTERIORI error estimators. The accuracy improvement is obtained with new equations that make the numerical procedure free of truncation errors and proposing spatial reconstructions of the angular fluxes that are more accurate than those used until present. An a POSTERIORI error estimator is rigurously obtained for one dimensional systems that, in certain type of problems, allows to quantify the accuracy of the solutions. From comparisons with the one dimensional results, an a POSTERIORI error estimator is also obtained for multidimensional systems. LOCAL indicators, which quantify the spatial distribution of the errors, are obtained by the decomposition of the menctioned estimators. This makes the proposed methodology suitable to perform adaptive calculations. Some numerical examples are presented to validate the theoretical developements and to illustrate the ranges where the proposed approximations are valid

  11. Accuracy Assessment of Coastal Topography Derived from Uav Images

    Long, N.; Millescamps, B.; Pouget, F.; Dumon, A.; Lachaussée, N.; Bertin, X.

    2016-06-01

    To monitor coastal environments, Unmanned Aerial Vehicle (UAV) is a low-cost and easy to use solution to enable data acquisition with high temporal frequency and spatial resolution. Compared to Light Detection And Ranging (LiDAR) or Terrestrial Laser Scanning (TLS), this solution produces Digital Surface Model (DSM) with a similar accuracy. To evaluate the DSM accuracy on a coastal environment, a campaign was carried out with a flying wing (eBee) combined with a digital camera. Using the Photoscan software and the photogrammetry process (Structure From Motion algorithm), a DSM and an orthomosaic were produced. Compared to GNSS surveys, the DSM accuracy is estimated. Two parameters are tested: the influence of the methodology (number and distribution of Ground Control Points, GCPs) and the influence of spatial image resolution (4.6 cm vs 2 cm). The results show that this solution is able to reproduce the topography of a coastal area with a high vertical accuracy (images is decreased.

  12. Prenatal diagnosis of cardiac defects : accuracy and benefit

    Clur, S. A.; Van Brussel, P. M.; Ottenkamp, J.; Bilardo, C. M.

    2012-01-01

    Objective The prenatal diagnosis of cardiac defects can potentially reduce postnatal morbidity and mortality. We wanted to evaluate prenatal cardiac diagnosis accuracy in a population referred for echocardiography. Methods Single centre retrospective study of echocardiography referrals between April

  13. 40 CFR 91.314 - Analyzer accuracy and specifications.

    2010-07-01

    ... deflection should generally not be used. (2) Some high resolution read-out systems, such as computers, data loggers, and so forth, can provide sufficient accuracy and resolution below 15 percent of full scale....

  14. Accuracy of analyses of microelectronics nanostructures in atom probe tomography

    Vurpillot, F.; Rolland, N.; Estivill, R.; Duguay, S.; Blavette, D.

    2016-07-01

    The routine use of atom probe tomography (APT) as a nano-analysis microscope in the semiconductor industry requires the precise evaluation of the metrological parameters of this instrument (spatial accuracy, spatial precision, composition accuracy or composition precision). The spatial accuracy of this microscope is evaluated in this paper in the analysis of planar structures such as high-k metal gate stacks. It is shown both experimentally and theoretically that the in-depth accuracy of reconstructed APT images is perturbed when analyzing this structure composed of an oxide layer of high electrical permittivity (higher-k dielectric constant) that separates the metal gate and the semiconductor channel of a field emitter transistor. Large differences in the evaporation field between these layers (resulting from large differences in material properties) are the main sources of image distortions. An analytic model is used to interpret inaccuracy in the depth reconstruction of these devices in APT.

  15. Simulation efficiency and accuracy of different moisture transfer potentials

    Janssen, Hans

    2014-01-01

    Simulation models for moisture transfer in building materials are highly incongruent with respect to the moisture potential used. Often the relatively better numerical efficiency and accuracy of a certain moisture potential is put forward as motivation. Various claims are made in that respect, but factual evidence is typically lacking. This paper aims at providing such support by assessing simulation efficiency and accuracy for capillary pressure, relative humidity and -log(-capillary pressur...

  16. Improvement of Electrochemical Machining Accuracy by Using Dual Pole Tool

    2002-01-01

    Electrochemical machining (ECM) is one of the best al ternatives for producing complex shapes in advanced materials used in aircraft a nd aerospace industries. However, the reduction of the stray material removal co ntinues to be major challenges for industries in addressing accuracy improvement . This study presents a method of improving machining accuracy in ECM by using a dual pole tool with a metallic bush outside the insulated coating of a cathode tool. The bush is connected with anode and so the el...

  17. The symmetric BEM: bringing in more variables for better accuracy

    Clerc, Maureen; Gramfort, Alexandre; Olivi, Emmanuel; Papadopoulo, Théodore

    2010-01-01

    Electrophysiological modeling of Magneto- and Electro-encephalography (MEG and EEG) rely on accurate forward solvers that relate source activities to sensor measurements. In comparing a Boundary Element (BEM) and a Finite Element Method (FEM) for forward electroencephalography, in our early numerical experiments, we found the FEM to have a better accuracy than the BEM. This triggered a quest to improve the accuracy of Boundary Element Methods and led us to study the extended Green representat...

  18. Acquisition Accuracy Evaluation in Visual Inspection Systems - a Practical Approach

    Arsinte, Radu; Miron, Costin

    2008-01-01

    This paper draws a proposal of a set of parameters and methods for accuracy evaluation of visual inspection systems. The case of a monochrome board is treated, but practically all conclusions and methods may be extended for colour acquisition. Basically, the proposed parameters are grouped in five sets as follows:Internal noise;Video ADC cuantisation parameters;Analogue processing section parameters;Dominant frequencies;Synchronisation (lock-in) accuracy. On basis of this set of parameters wa...

  19. Method for Improving Indoor Positioning Accuracy Using Extended Kalman Filter

    Lee, Seoung-Hyeon; Lim, Il-Kwan; Lee, Jae-Kwang

    2016-01-01

    Beacons using bluetooth low-energy (BLE) technology have emerged as a new paradigm of indoor positioning service (IPS) because of their advantages such as low power consumption, miniaturization, wide signal range, and low cost. However, the beacon performance is poor in terms of the indoor positioning accuracy because of noise, motion, and fading, all of which are characteristics of a bluetooth signal and depend on the installation location. Therefore, it is necessary to improve the accuracy ...

  20. An RFID implementation in the automotive industry - improving inventory accuracy

    Hellström, Daniel; Wiberg, Mathias

    2010-01-01

    This paper explores and describes the impact of radio frequency identification (RFID) technology on inventory accuracy within a production and assembly plant, and proposes a model for assessing the impact of the technology on inventory accuracy. The empirical investigation, based on case study research, focuses on a RFID implementation at a supplier of bumper and spoiler systems to the automotive industry. The results indicate that RFID ensures that inventory inaccurac...

  1. Accuracy of gas analysis in lung function laboratories.

    Chinn, D.J.; Naruse, Y; Cotes, J E

    1986-01-01

    Fifty lung function laboratories in England and Wales analysed test gas mixtures of carbon monoxide and helium. Most of them also analysed mixtures of oxygen and carbon dioxide in nitrogen. The percentage accuracy of the results was within 1% of the expected value in only 14% of determinations of carbon monoxide concentration, 28% for carbon dioxide, 37% for helium, and 48% for oxygen. The accuracy of ratios of two concentrations of helium and carbon monoxide was better than that of the indiv...

  2. Determining factors for the accuracy of DMRG in chemistry.

    Keller, Sebastian F; Reiher, Markus

    2014-01-01

    The Density Matrix Renormalization Group (DMRG) algorithm has been a rising star for the accurate ab initio exploration of Born-Oppenheimer potential energy surfaces in theoretical chemistry. However, owing to its iterative numerical nature, pitfalls that can affect the accuracy of DMRG energies need to be circumvented. Here, after a brief introduction into this quantum chemical method, we discuss criteria that determine the accuracy of DMRG calculations. PMID:24983596

  3. Application Accuracy of Automatic Registration in Frameless Stereotaxy

    Rachinger, Jens; Keller, Boris von; Ganslandt, Oliver; Fahlbusch, Rudolf; Nimsky, Christopher

    2013-01-01

    Objective: We compared the application accuracy of an infrared- based neuronavigation system when used with a novel automatic registration with its application accuracy when standard fiducial-based registration is performed. Methods: The automatic referencing tool is based on markers that are integrated in the headrest holder we routinely use in our intraoperative magnetic resonance imaging (MRI) setting and can be detected by the navigation software automatically. For navigation targeting we...

  4. The evaluation of singing voice accuracy: How tolerant are we?

    Larrouy, Pauline; Blanckaert, Ellen; Morsomme, Dominique

    2013-01-01

    The evaluation of the singing voice accuracy is partly based on the precision of the intervals between the tones of a sung performance. This study aims to observe the listeners’ tolerance when judging melodies in order to properly evaluate the singing voice accuracy in a melodic context For this purpose, an interval contained in familiar and unfamiliar sung performances was manipulated in two directions (compression and enlargement from 10 to 60 cents). This material was presented through ...

  5. Accuracy of depth of cut in micro milling operations

    Bissacco, Giuliano

    2003-01-01

    In any kind of conventional machining operation, dimensional and geometrical accuracy of the machined part cannot be achieved without a precise control of cutting parameters as well as positioning accuracy. Miniaturization of components implies a reduction of all component’s dimensions and involves downscaling of conventional manufacturing technologies. Although in micro manufacturing operations particular precautions are taken, the ratio between tolerances and absolute dimensions increases. ...

  6. The correlation between accent perception accuracy and listening proficiency

    田方

    2012-01-01

    This study tries to examine the correlation between Chinese EFL learners' accent perception accuracy of and their lis- tening proficiency. Accent annotation data were collected from 80 English-majored freshmen and sophomores. Results show that their accent perception accuracy is positively related to their listening proficiency. Therefore, it is concluded that the teaching of the accent should be enhanced to help students overcome some supersegmental obstacles in their listening.

  7. Interference-free ultrasonic level measuring sensor

    To avoid interference phenomena depending on the level, an ultrasonic level measuring sensor is proposed, which has an envelope tube around the path of the ultrasonic signal to prevent reflection. An ultrasonic transducer suspended by means of a linkage on a flange is additionally provided with a corrugated hose or a sintered metal tube around the path of the ultrasonic signal. A reference element necessary to raise the accuracy can be fitted in a cutout of the envelope tube. This device makes very precise measurement of the level possible without variations in the accuracy of measurement depending on the level, as interference due to shunt reflection is prevented. (orig./HP)

  8. Distinguishing Fast and Slow Processes in Accuracy - Response Time Data.

    Frederik Coomans

    Full Text Available We investigate the relation between speed and accuracy within problem solving in its simplest non-trivial form. We consider tests with only two items and code the item responses in two binary variables: one indicating the response accuracy, and one indicating the response speed. Despite being a very basic setup, it enables us to study item pairs stemming from a broad range of domains such as basic arithmetic, first language learning, intelligence-related problems, and chess, with large numbers of observations for every pair of problems under consideration. We carry out a survey over a large number of such item pairs and compare three types of psychometric accuracy-response time models present in the literature: two 'one-process' models, the first of which models accuracy and response time as conditionally independent and the second of which models accuracy and response time as conditionally dependent, and a 'two-process' model which models accuracy contingent on response time. We find that the data clearly violates the restrictions imposed by both one-process models and requires additional complexity which is parsimoniously provided by the two-process model. We supplement our survey with an analysis of the erroneous responses for an example item pair and demonstrate that there are very significant differences between the types of errors in fast and slow responses.

  9. Distinguishing Fast and Slow Processes in Accuracy - Response Time Data.

    Coomans, Frederik; Hofman, Abe; Brinkhuis, Matthieu; van der Maas, Han L J; Maris, Gunter

    2016-01-01

    We investigate the relation between speed and accuracy within problem solving in its simplest non-trivial form. We consider tests with only two items and code the item responses in two binary variables: one indicating the response accuracy, and one indicating the response speed. Despite being a very basic setup, it enables us to study item pairs stemming from a broad range of domains such as basic arithmetic, first language learning, intelligence-related problems, and chess, with large numbers of observations for every pair of problems under consideration. We carry out a survey over a large number of such item pairs and compare three types of psychometric accuracy-response time models present in the literature: two 'one-process' models, the first of which models accuracy and response time as conditionally independent and the second of which models accuracy and response time as conditionally dependent, and a 'two-process' model which models accuracy contingent on response time. We find that the data clearly violates the restrictions imposed by both one-process models and requires additional complexity which is parsimoniously provided by the two-process model. We supplement our survey with an analysis of the erroneous responses for an example item pair and demonstrate that there are very significant differences between the types of errors in fast and slow responses. PMID:27167518

  10. Bayesian Estimation of Combined Accuracy for Tests with Verification Bias

    Lyle D. Broemeling

    2011-12-01

    Full Text Available This presentation will emphasize the estimation of the combined accuracy of two or more tests when verification bias is present. Verification bias occurs when some of the subjects are not subject to the gold standard. The approach is Bayesian where the estimation of test accuracy is based on the posterior distribution of the relevant parameter. Accuracy of two combined binary tests is estimated employing either “believe the positive” or “believe the negative” rule, then the true and false positive fractions for each rule are computed for two tests. In order to perform the analysis, the missing at random assumption is imposed, and an interesting example is provided by estimating the combined accuracy of CT and MRI to diagnose lung cancer. The Bayesian approach is extended to two ordinal tests when verification bias is present, and the accuracy of the combined tests is based on the ROC area of the risk function. An example involving mammography with two readers with extreme verification bias illustrates the estimation of the combined test accuracy for ordinal tests.

  11. New advances in the study of the confidence-accuracy relationship in the memory for events

    Beatriz Martin-Luengo

    2010-01-01

    Full Text Available It has been suggested that calibration, and not correlation, could be a better analysis to examine the confidence-accuracy relationship. Calibration refers to the degree in which confidence ratings correspond with the objective probability that the answer is correct. However, to date calibration has been calculated only in a few studies that have addressed eyewitness identification, and never in the memory for events. For this reason, four experiments were conducted to examine the calibration between confidence and accuracy in the recognition and recall of a criminal situation. The basic procedure involved the presentation of a crime through slides or video, followed by a questionnaire. Confidence ratings were also required. Results showed in general a good confidence-accuracy calibration, with variations depending on the memory test and the variables manipulated. They also showed that participants are slightly overconfident, and that they do not calibrate confidence well in the low-medium levels of difficulty. The main conclusion of this research is that confidence could help to evaluate the accuracy of a testimony under certain circumstances, although generalising the results to real-life situations should be done with caution.

  12. Analysis of the Kinematic Accuracy Reliability of a 3-DOF Parallel Robot Manipulator

    Guohua Cui

    2015-02-01

    Full Text Available Kinematic accuracy reliability is an important performance index in the evaluation of mechanism quality. By using a 3- DOF 3-PUU parallel robot manipulator as the research object, the position and orientation error model was derived by mapping the relation between the input and output of the mechanism. Three error sensitivity indexes that evaluate the kinematic accuracy of the parallel robot manipulator were obtained by adapting the singular value decomposition of the error translation matrix. Considering the influence of controllable and uncontrollable factors on the kinematic accuracy, the mathematical model of reliability based on random probability was employed. The measurement and calculation method for the evaluation of the mechanism’s kinematic reliability level was also provided. By analysing the mechanism’s errors and reliability, the law of surface error sensitivity for the location and structure parameters was obtained. The kinematic reliability of the parallel robot manipulator was statistically computed on the basis of the Monte Carlo simulation method. The reliability analysis of kinematic accuracy provides a theoretical basis for design optimization and error compensation.

  13. Emotion perception accuracy and bias in face-to-face versus cyberbullying.

    Ciucci, Enrica; Baroncelli, Andrea; Nowicki, Stephen

    2014-01-01

    The authors investigated the association of traditional and cyber forms of bullying and victimization with emotion perception accuracy and emotion perception bias. Four basic emotions were considered (i.e., happiness, sadness, anger, and fear); 526 middle school students (280 females; M age = 12.58 years, SD = 1.16 years) were recruited, and emotionality was controlled. Results indicated no significant findings for girls. Boys with higher levels of traditional bullying did not show any deficit in perception accuracy of emotions, but they were prone to identify happiness and fear in faces when a different emotion was expressed; in addition, male cyberbullying was related to greater accuracy in recognizing fear. In terms of the victims, cyber victims had a global problem in recognizing emotions and a specific problem in processing anger and fear. It was concluded that emotion perception accuracy and bias were associated with bullying and victimization for boys not only in traditional settings but also in the electronic ones. Implications of these findings for possible intervention are discussed. PMID:25271816

  14. Analysis of machining accuracy during free form surface milling simulation for different milling strategies

    Matras, A.; Kowalczyk, R.

    2014-11-01

    The analysis results of machining accuracy after the free form surface milling simulations (based on machining EN AW- 7075 alloys) for different machining strategies (Level Z, Radial, Square, Circular) are presented in the work. Particular milling simulations were performed using CAD/CAM Esprit software. The accuracy of obtained allowance is defined as a difference between the theoretical surface of work piece element (the surface designed in CAD software) and the machined surface after a milling simulation. The difference between two surfaces describes a value of roughness, which is as the result of tool shape mapping on the machined surface. Accuracy of the left allowance notifies in direct way a surface quality after the finish machining. Described methodology of usage CAD/CAM software can to let improve a time design of machining process for a free form surface milling by a 5-axis CNC milling machine with omitting to perform the item on a milling machine in order to measure the machining accuracy for the selected strategies and cutting data.

  15. An action-incongruent secondary task modulates prediction accuracy in experienced performers: evidence for motor simulation.

    Mulligan, Desmond; Lohse, Keith R; Hodges, Nicola J

    2016-07-01

    We provide behavioral evidence that the human motor system is involved in the perceptual decision processes of skilled performers, directly linking prediction accuracy to the (in)ability of the motor system to activate in a response-specific way. Experienced and non-experienced dart players were asked to predict, from temporally occluded video sequences, the landing position of a dart thrown previously by themselves (self) or another (other). This prediction task was performed while additionally performing (a) an action-incongruent secondary motor task (right arm force production), (b) a congruent secondary motor task (mimicking) or (c) an attention-matched task (tone-monitoring). Non-experienced dart players were not affected by any of the secondary task manipulations, relative to control conditions, yet prediction accuracy decreased for the experienced players when additionally performing the force-production, motor task. This interference effect was present for 'self' as well as 'other' decisions, reducing the accuracy of experienced participants to a novice level. The mimicking (congruent) secondary task condition did not interfere with (or facilitate) prediction accuracy for either group. We conclude that visual-motor experience moderates the process of decision making, such that a seemingly visual-cognitive prediction task relies on activation of the motor system for experienced performers. This fits with a motor simulation account of action prediction in sports and other tasks, and alerts to the specificity of these simulative processes. PMID:26021748

  16. Sensor modeling, self-calibration and accuracy testing of panoramic cameras and laser scanners

    Amiri Parian, Jafar; Gruen, Armin

    2010-01-01

    Terrestrial Linear Array CCD-based panoramic cameras have been used for purely imaging purposes, but they also have a high potential for use in high accuracy measurement applications. The imaging geometry and the high information content of those images make them suitable candidates for quantitative image analysis. For that a particular sensor model has to be established and the inherent accuracy potential has to be investigated. We developed a sensor model for terrestrial Linear Array-based panoramic cameras by means of a modified bundle adjustment with additional parameters, which models substantial deviations of a real camera from the ideal one. We used 3D straight-line information in addition to tie points to conduct a full calibration and orientation without control point information. Due to the similarity of the operation of laser scanners to panoramic cameras the sensor model of the panoramic cameras was extended for the self-calibration of laser scanners. We present the joint sensor model for panoramic cameras and laser scanners and the results of self-calibration, which indicate a subpixel accuracy level for such highly dynamic systems. Finally we demonstrate the systems' accuracy of two typical panoramic cameras in 3D point positioning, using both a minimal number of control points and a free network adjustment. With these new panoramic imaging devices we have additional powerful sensors for image recording and efficient 3D object modeling.

  17. The effect of observer experience on the accuracy of knee MRI interpretation: a preliminary study

    Research on knee MRI has traditionally used experienced musculoskeletal radiologists to assess the performance of knee MRI. These observers are not representative of the typical experience level of radiologists reporting knee MRI in Australia. The accuracy of knee MRI in the Australian setting is therefore uncertain. A preliminary study was performed to determine the influence of observer experience on the accuracy of knee MRI. Eleven knee MRI studies were reviewed by eight different radiologists (three experienced, five less experienced). In each case the diagnoses and diagnostic confidence were recorded, the latter by means of a visual analogue scale. Arthroscopy was used as the gold standard for meniscal, cruciate and cartilage pathology. The standard for other diagnoses was set by consensus of the two most experienced observers. The experienced observers exhibited superior diagnostic accuracy (p < 0.05) and higher sensitivity. Diagnostic confidence was higher (p < 0.05) when true positive diagnoses were made by experienced and inexperienced observers. This preliminary study suggests a link between observer experience and the diagnostic accuracy and diagnostic confidence of observers reporting knee MRI. Copyright (1999) Australian Institute of Radiography

  18. Cortisol level

    ... enable JavaScript. The cortisol blood test measures the level of cortisol in the blood. Cortisol is a ... in the morning. This is important, because cortisol level varies throughout the day. You may be asked ...

  19. Loss of accuracy using smeared properties in composite beam modeling

    Liu, Ning

    Advanced composite materials have broad, proven applications in many engineering systems ranging from sports equipment sectors to components on the space shuttle because of their lightweight characteristics and significantly high stiffness. Together with this merit of composite materials is the challenge of improving computational simulation process for composites analysis. Composite structures, particularly composite laminates, usually consist of many layers with different lay-up angles. The anisotropic and heterogeneous features render 3D finite element analysis (FEA) computationally expensive in terms of the computational time and the computing power. At the constituent level, composite materials are heterogeneous. But quite often one homogenizes each layer of composites, i.e. lamina, and uses the homogenized material properties as averaged (smeared) values of those constituent materials for analysis. This is an approach extensively used in design and analysis of composite laminates. Furthermore, many industries tempted to use smeared properties at the laminate level to further reduce the model of composite structures. At this scale, smeared properties are averaged material properties that are weighted by the layer thickness. Although this approach has the advantage of saving computational time and cost of modeling significantly, the prediction of the structural responses may not be accurate, particularly the pointwise stress distribution. Therefore, it is important to quantify the loss of accuracy when one uses smeared properties. In this paper, several different benchmark problems are carefully investigated in order to exemplify the effect of the smeared properties on the global behavior and pointwise stress distribution of the composite beam. In the classical beam theory, both Newtonian method and variational method include several ad hoc assumptions to construct the model, however, these assumptions are avoided if one uses variational asymptotic method. VABS

  20. Wind power forecasting accuracy and uncertainty in Finland

    Holttinen, H.; Miettinen, J.; Sillanpaeae, S.

    2013-04-15

    Wind power cannot be dispatched so the production levels need to be forecasted for electricity market trading. Lower prediction errors mean lower regulation balancing costs, since relatively less energy needs to go through balance settlement. From the power system operator point of view, wind power forecast errors will impact the system net imbalances when the share of wind power increases, and more accurate forecasts mean less regulating capacity will be activated from the real time Regulating Power Market. In this publication short term forecasting of wind power is studied mainly from a wind power producer point of view. The forecast errors and imbalance costs from the day-ahead Nordic electricity markets are calculated based on real data from distributed wind power plants. Improvements to forecasting accuracy are presented using several wind forecast providers, and measures for uncertainty of the forecast are presented. Aggregation of sites lowers relative share of prediction errors considerably, up to 60%. The balancing costs were also reduced up to 60%, from 3 euro/MWh for one site to 1-1.4 euro/MWh to aggregate 24 sites. Pooling wind power production for balance settlement will be very beneficial, and larger producers who can have sites from larger geographical area will benefit in lower imbalance costs. The aggregation benefits were already significant for smaller areas, resulting in 30-40% decrease in forecast errors and 13-36% decrease in unit balancing costs, depending on the year. The resulting costs are strongly dependent on Regulating Market prices that determine the prices for the imbalances. Similar level of forecast errors resulted in 40% higher imbalance costs for 2012 compared with 2011. Combining wind forecasts from different Numerical Weather Prediction providers was studied with different combination methods for 6 sites. Averaging different providers' forecasts will lower the forecast errors by 6% for day-ahead purposes. When combining

  1. Effect of Kinesiotape Applications on Ball Velocity and Accuracy in Amateur Soccer and Handball.

    Müller, Carsten; Brandes, Mirko

    2015-12-22

    Evidence supporting performance enhancing effects of kinesiotape in sports is missing. The aims of this study were to evaluate effects of kinesiotape applications with regard to shooting and throwing performance in 26 amateur soccer and 32 handball players, and to further investigate if these effects were influenced by the players' level of performance. Ball speed as the primary outcome and accuracy of soccer kicks and handball throws were analyzed with and without kinesiotape by means of radar units and video recordings. The application of kinesiotapes significantly increased ball speed in soccer by 1.4 km/h (p=0.047) and accuracy with a lesser distance from the target by -6.9 cm (p=0.039). Ball velocity in handball throws also significantly increased by 1.2 km/h (p=0.013), while accuracy was deteriorated with a greater distance from the target by 3.4 cm (p=0.005). Larger effects with respect to ball speed were found in players with a lower performance level in kicking (1.7 km/h, p=0.028) and throwing (1.8 km/h, p=0.001) compared with higher level soccer and handball players (1.2 km/h, p=0.346 and 0.5 km/h, p=0.511, respectively). In conclusion, the applications of kinesiotape used in this study might have beneficial effects on performance in amateur soccer, but the gain in ball speed in handball is counteracted by a significant deterioration of accuracy. Subgroup analyses indicate that kinesiotape may yield larger effects on ball velocity in athletes with lower kicking and throwing skills. PMID:26839612

  2. Effect of Kinesiotape Applications on Ball Velocity and Accuracy in Amateur Soccer and Handball

    Müller Carsten

    2015-12-01

    Full Text Available Evidence supporting performance enhancing effects of kinesiotape in sports is missing. The aims of this study were to evaluate effects of kinesiotape applications with regard to shooting and throwing performance in 26 amateur soccer and 32 handball players, and to further investigate if these effects were influenced by the players’ level of performance. Ball speed as the primary outcome and accuracy of soccer kicks and handball throws were analyzed with and without kinesiotape by means of radar units and video recordings. The application of kinesiotapes significantly increased ball speed in soccer by 1.4 km/h (p=0.047 and accuracy with a lesser distance from the target by -6.9 cm (p=0.039. Ball velocity in handball throws also significantly increased by 1.2 km/h (p=0.013, while accuracy was deteriorated with a greater distance from the target by 3.4 cm (p=0.005. Larger effects with respect to ball speed were found in players with a lower performance level in kicking (1.7 km/h, p=0.028 and throwing (1.8 km/h, p=0.001 compared with higher level soccer and handball players (1.2 km/h, p=0.346 and 0.5 km/h, p=0.511, respectively. In conclusion, the applications of kinesiotape used in this study might have beneficial effects on performance in amateur soccer, but the gain in ball speed in handball is counteracted by a significant deterioration of accuracy. Subgroup analyses indicate that kinesiotape may yield larger effects on ball velocity in athletes with lower kicking and throwing skills.

  3. Accuracy of Protein Embedding Potentials: An Analysis in Terms of Electrostatic Potentials

    Olsen, Jogvan Magnus Haugaard; List, Nanna Holmgaard; Kristensen, Kasper;

    2015-01-01

    Quantum-mechanical embedding methods have in recent years gained significant interest and may now be applied to predict a wide range of molecular properties calculated at different levels of theory. To reach a high level of accuracy in embedding methods, both the electronic structure model of the...... fragmentation strategies combined with single-fragment ab initio calculations. In fact, due to the self-interaction error in Kohn–Sham density functional theory (KS-DFT), use of large full-structure quantum-mechanical calculations based on conventional (hybrid) functionals leads to less accurate embedding...

  4. Accuracy of magnetic resonance in identifying traumatic intraarticular knee lesions

    Vaz Carlos Eduardo Sanches

    2005-01-01

    Full Text Available PURPOSE: To evaluate the diagnostic accuracy of magnetic resonance imaging of the knee in identifying traumatic intraarticular knee lesions. METHOD: 300 patients with a clinical diagnosis of traumatic intraarticular knee lesions underwent prearthoscopic magnetic resonance imaging. The sensitivity, specificity, positive predictive value, negative predictive value, likelihood ratio for a positive test, likelihood ratio for a negative test, and accuracy of magnetic resonance imaging were calculated relative to the findings during arthroscopy in the studied structures of the knee (medial meniscus, lateral meniscus, anterior cruciate ligament, posterior cruciate ligament, and articular cartilage. RESULTS: Magnetic resonance imaging produced the following results regarding detection of lesions: medial meniscus: sensitivity 97.5%, specificity 92.9%, positive predictive value 93.9%, positive negative value 97%, likelihood positive ratio 13.7, likelihood negative ratio 0.02, and accuracy 95.3%; lateral meniscus: sensitivity 91.9%, specificity 93.6%, positive predictive value 92.7%, positive negative value 92.9%, likelihood positive ratio 14.3, likelihood negative ratio 0.08, and accuracy 93.6%; anterior cruciate ligament: sensitivity 99.0%, specificity 95.9%, positive predictive value 91.9%, positive negative value 99.5%, likelihood positive ratio 21.5, likelihood negative ratio 0.01, and accuracy 96.6%; posterior cruciate ligament: sensitivity 100%, specificity 99%, positive predictive value 80.0%, positive negative value 100%, likelihood positive ratio 100, likelihood negative ratio 0.01, and accuracy 99.6%; articular cartilage: sensitivity 76.1%, specificity 94.9%, positive predictive value 94.7%, positive negative value 76.9%, likelihood positive ratio 14.9, likelihood negative ratio 0.25, and accuracy 84.6%. CONCLUSION: Magnetic resonance imaging is a satisfactory diagnostic tool for evaluating meniscal and ligamentous lesions of the knee, but it is

  5. Accuracy evaluation of 3D lidar data from small UAV

    Tulldahl, H. M.; Bissmarck, Fredrik; Larsson, Hâkan; Grönwall, Christina; Tolt, Gustav

    2015-10-01

    A UAV (Unmanned Aerial Vehicle) with an integrated lidar can be an efficient system for collection of high-resolution and accurate three-dimensional (3D) data. In this paper we evaluate the accuracy of a system consisting of a lidar sensor on a small UAV. High geometric accuracy in the produced point cloud is a fundamental qualification for detection and recognition of objects in a single-flight dataset as well as for change detection using two or several data collections over the same scene. Our work presented here has two purposes: first to relate the point cloud accuracy to data processing parameters and second, to examine the influence on accuracy from the UAV platform parameters. In our work, the accuracy is numerically quantified as local surface smoothness on planar surfaces, and as distance and relative height accuracy using data from a terrestrial laser scanner as reference. The UAV lidar system used is the Velodyne HDL-32E lidar on a multirotor UAV with a total weight of 7 kg. For processing of data into a geographically referenced point cloud, positioning and orientation of the lidar sensor is based on inertial navigation system (INS) data combined with lidar data. The combination of INS and lidar data is achieved in a dynamic calibration process that minimizes the navigation errors in six degrees of freedom, namely the errors of the absolute position (x, y, z) and the orientation (pitch, roll, yaw) measured by GPS/INS. Our results show that low-cost and light-weight MEMS based (microelectromechanical systems) INS equipment with a dynamic calibration process can obtain significantly improved accuracy compared to processing based solely on INS data.

  6. Accuracy analysis and design of A3 parallel spindle head

    Ni, Yanbing; Zhang, Biao; Sun, Yupeng; Zhang, Yuan

    2016-03-01

    As functional components of machine tools, parallel mechanisms are widely used in high efficiency machining of aviation components, and accuracy is one of the critical technical indexes. Lots of researchers have focused on the accuracy problem of parallel mechanisms, but in terms of controlling the errors and improving the accuracy in the stage of design and manufacturing, further efforts are required. Aiming at the accuracy design of a 3-DOF parallel spindle head(A3 head), its error model, sensitivity analysis and tolerance allocation are investigated. Based on the inverse kinematic analysis, the error model of A3 head is established by using the first-order perturbation theory and vector chain method. According to the mapping property of motion and constraint Jacobian matrix, the compensatable and uncompensatable error sources which affect the accuracy in the end-effector are separated. Furthermore, sensitivity analysis is performed on the uncompensatable error sources. The sensitivity probabilistic model is established and the global sensitivity index is proposed to analyze the influence of the uncompensatable error sources on the accuracy in the end-effector of the mechanism. The results show that orientation error sources have bigger effect on the accuracy in the end-effector. Based upon the sensitivity analysis results, the tolerance design is converted into the issue of nonlinearly constrained optimization with the manufacturing cost minimum being the optimization objective. By utilizing the genetic algorithm, the allocation of the tolerances on each component is finally determined. According to the tolerance allocation results, the tolerance ranges of ten kinds of geometric error sources are obtained. These research achievements can provide fundamental guidelines for component manufacturing and assembly of this kind of parallel mechanisms.

  7. Personal noise dosimeters: Accuracy and reliability in varied settings

    Sheri Lynn Cook-Cunningham

    2014-01-01

    Full Text Available This study investigated the accuracy, reliability, and characteristics of three brands of personal noise dosimeters (N = 7 units in both pink noise (PN environments and natural environments (NEs through the acquisition of decibel readings, Leq readings and noise doses. Acquisition periods included repeated PN conditions, choir room rehearsals and participant (N = 3 Leq and noise dosages procured during a day in the life of a music student. Among primary results: (a All dosimeters exhibited very strong positive correlations for PN measurements across all instruments; (b all dosimeters were within the recommended American National Standard Institute (ANSI SI.25-1991 standard of ±2 dB (A of a reference measurement; and (c all dosimeters were within the recommended ANSI SI.25-1991 standard of ±2 dB (A when compared with each other. Results were discussed in terms of using personal noise dosimeters within hearing conservation and research contexts and recommendations for future research. Personal noise dosimeters were studied within the contexts of PN environments and NEs (choral classroom and the day in the life of collegiate music students. This quantitative study was a non-experimental correlation design. Three brands of personal noise dosimeters (Cirrus doseBadge, Quest Edge Eg5 and Etymotic ER200D were tested in two environments, a PN setting and a natural setting. There were two conditions within each environment. In the PN environment condition one, each dosimeter was tested individually in comparison with two reference measuring devices (Ivie and Easera while PN was generated by a Whites Instrument PN Tube. In condition two, the PN procedures were replicated for longer periods while all dosimeters measured the sound levels simultaneously. In the NE condition one, all dosimeters were placed side by side on a music stand and recorded sound levels of choir rehearsals over a 7-h rehearsal period. In NE, condition two noise levels were measured

  8. Personal noise dosimeters: accuracy and reliability in varied settings.

    Cook-Cunningham, Sheri Lynn

    2014-01-01

    This study investigated the accuracy, reliability, and characteristics of three brands of personal noise dosimeters (N = 7 units) in both pink noise (PN) environments and natural environments (NEs) through the acquisition of decibel readings, Leq readings and noise doses. Acquisition periods included repeated PN conditions, choir room rehearsals and participant (N = 3) Leq and noise dosages procured during a day in the life of a music student. Among primary results: (a) All dosimeters exhibited very strong positive correlations for PN measurements across all instruments; (b) all dosimeters were within the recommended American National Standard Institute (ANSI) SI.25-1991 standard of ±2 dB (A) of a reference measurement; and (c) all dosimeters were within the recommended ANSI SI.25-1991 standard of ±2 dB (A) when compared with each other. Results were discussed in terms of using personal noise dosimeters within hearing conservation and research contexts and recommendations for future research. Personal noise dosimeters were studied within the contexts of PN environments and NEs (choral classroom and the day in the life of collegiate music students). This quantitative study was a non-experimental correlation design. Three brands of personal noise dosimeters (Cirrus doseBadge, Quest Edge Eg5 and Etymotic ER200D) were tested in two environments, a PN setting and a natural setting. There were two conditions within each environment. In the PN environment condition one, each dosimeter was tested individually in comparison with two reference measuring devices (Ivie and Easera) while PN was generated by a Whites Instrument PN Tube. In condition two, the PN procedures were replicated for longer periods while all dosimeters measured the sound levels simultaneously. In the NE condition one, all dosimeters were placed side by side on a music stand and recorded sound levels of choir rehearsals over a 7-h rehearsal period. In NE, condition two noise levels were measured during

  9. Accuracy in HIV Rapid Testing among Laboratory and Non-laboratory Personnel in Zambia: Observations from the National HIV Proficiency Testing System.

    Sheila Mwangala

    Full Text Available Despite rapid task-shifting and scale-up of HIV testing services in high HIV prevalence countries, studies evaluating accuracy remain limited. This study aimed to assess overall accuracy level and factors associated with accuracy in HIV rapid testing in Zambia.Accuracy was investigated among rural and urban HIV testing sites participating in two annual national HIV proficiency testing (PT exercises conducted in 2009 (n = 282 sites and 2010 (n = 488 sites. Testers included lay counselors, nurses, laboratory personnel and others. PT panels of five dry tube specimens (DTS were issued to testing sites by the national reference laboratory (NRL. Site accuracy level was assessed by comparison of reported results to the expected results. Non-parametric rank tests and multiple linear regression models were used to assess variation in accuracy between PT cycles and between tester groups, and to examine factors associated with accuracy respectively.Overall accuracy level was 93.1% (95% CI: 91.2-94.9 in 2009 and 96.9% (95% CI: 96.1-97.8 in 2010. Differences in accuracy were seen between the tester groups in 2009 with laboratory personnel being more accurate than non-laboratory personnel, while in 2010 no differences were seen. In both PT exercises, lay counselors and nurses had more difficulties interpreting results, with more occurrences of false-negative, false-positive and indeterminate results. Having received the standard HIV rapid testing training and adherence to the national HIV testing algorithm were positively associated with accuracy.The study showed an improvement in tester group and overall accuracy from the first PT exercise to the next. Average number of incorrect test results per 1000 tests performed was reduced from 69 to 31. Further improvement is needed, however, and the national HIV proficiency testing system seems to be an important tool in this regard, which should be continued and needs to be urgently strengthened.

  10. Accuracy of needle position measurements using fiber Bragg gratings.

    Henken, Kirsten; Van Gerwen, Dennis; Dankelman, Jenny; Van Den Dobbelsteen, John

    2012-11-01

    Accurate placement of the needle tip is essential in percutaneous therapies such as radiofrequency ablation (RFA) of liver tumors. Use of a robotic system for navigating the needle could improve the targeting accuracy. Real-time information on the needle tip position is needed, since a needle deflects during insertion in tissue. Needle shape can be reconstructed based on strain measurements within the needle. In the current experiment we determined the accuracy with which the needle tip position can be derived from strain measurements using Fiber Bragg Gratings (FBGs). Three glass fibers equipped with two FBGs each were incorporated in a needle. The needle was clamped at one end and deformed by applying static radial displacements at one or two locations. The FBG output was used for offline estimation of the needle shape and tip position. During deflections of the needle tip up to 12.5 mm, the tip position was estimated with a mean accuracy of 0.89 mm (std 0.42 mm). Adding a second deflection resulted in an error of 1.32 mm (std 0.48 mm). This accuracy is appropriate for applications such as RFA of liver tumors. The results further show that the accuracy can be improved by optimizing the placement of FBGs. PMID:22455615

  11. Evidence for Enhanced Interoceptive Accuracy in Professional Musicians

    Schirmer-Mokwa, Katharina L.; Fard, Pouyan R.; Zamorano, Anna M.; Finkel, Sebastian; Birbaumer, Niels; Kleber, Boris A.

    2015-01-01

    Interoception is defined as the perceptual activity involved in the processing of internal bodily signals. While the ability of internal perception is considered a relatively stable trait, recent data suggest that learning to integrate multisensory information can modulate it. Making music is a uniquely rich multisensory experience that has shown to alter motor, sensory, and multimodal representations in the brain of musicians. We hypothesize that musical training also heightens interoceptive accuracy comparable to other perceptual modalities. Thirteen professional singers, twelve string players, and thirteen matched non-musicians were examined using a well-established heartbeat discrimination paradigm complemented by self-reported dispositional traits. Results revealed that both groups of musicians displayed higher interoceptive accuracy than non-musicians, whereas no differences were found between singers and string-players. Regression analyses showed that accumulated musical practice explained about 49% variation in heartbeat perception accuracy in singers but not in string-players. Psychometric data yielded a number of psychologically plausible inter-correlations in musicians related to performance anxiety. However, dispositional traits were not a confounding factor on heartbeat discrimination accuracy. Together, these data provide first evidence indicating that professional musicians show enhanced interoceptive accuracy compared to non-musicians. We argue that musical training largely accounted for this effect. PMID:26733836

  12. Accuracy of a wireless localization system for radiotherapy

    Purpose: A system has been developed for patient positioning based on real-time localization of implanted electromagnetic transponders (beacons). This study demonstrated the accuracy of the system before clinical trials. Methods and materials: We describe the overall system. The localization component consists of beacons and a source array. A rigid phantom was constructed to place the beacons at known offsets from a localization array. Tests were performed at distances of 80 and 270 mm from the array and at positions in the array plane of up to 8 cm offset. Tests were performed in air and saline to assess the effect of tissue conductivity and with multiple transponders to evaluate crosstalk. Tracking was tested using a dynamic phantom creating a circular path at varying speeds. Results: Submillimeter accuracy was maintained throughout all experiments. Precision was greater proximal to the source plane (σx = 0.006 mm, σy = 0.01 mm, σz = 0.006 mm), but continued to be submillimeter at the end of the designed tracking range at 270 mm from the array (σx = 0.27 mm, σy = 0.36 mm, σz = 0.48 mm). The introduction of saline and the use of multiple beacons did not affect accuracy. Submillimeter accuracy was maintained using the dynamic phantom at speeds of up to 3 cm/s. Conclusion: This system has demonstrated the accuracy needed for localization and monitoring of position during treatment

  13. EVALUATING PARAMETERS AFFECTING THE GEOREFERENCING ACCURACY OF TERRESTRIAL LASER SCANNERS

    M. Miri

    2012-09-01

    Full Text Available Today laser scanning is used as a powerful technology in measuring various simple and complex objects in cultural heritage applications. Depending on the size and the complexity of the objects, these measurements are usually made from several stations. Similar to all other surveying techniques, the coordinate systems of such measurements need to be registered. For this, a number of retro-reflective targets visible from different stations are used. In practice, the target centres are entered in the computations. The accuracy of the target centres, therefore, need to be high or the final object coordinates might not be of sufficient accuracy. A number of factors including the distance between a target and the laser scanner, the direction of the target surface with respect to the laser scanner beams, the intensity and the number of reflected laser beams affect the accuracy of target centres. In this paper, various tests are carried out to examine the effect of such factors on the accuracy of coordinates obtained for the target centres. The results show that the distance to the laser scanner and the angle between a target surface and the corresponding laser beams have considerable effects on the locational accuracy of the targets.

  14. Evidence for enhanced interoceptive accuracy in professional musicians

    Katharina eSchirmer-Mokwa

    2015-12-01

    Full Text Available Interoception is defined as the perceptual activity involved in the processing of internal bodily signals. While the ability of internal perception is considered a relatively stable trait, recent data suggest that learning to integrate multisensory information can modulate it. Making music is a uniquely rich multisensory experience that has shown to alter motor, sensory, and multimodal representations in the brain of musicians. We hypothesize that musical training also heightens interoceptive accuracy comparable to other perceptual modalities. Thirteen professional singers, twelve string players, and thirteen matched non-musicians were examined using a well-established heartbeat discrimination paradigm complemented by self-reported dispositional traits. Results revealed that both groups of musicians displayed higher interoceptive accuracy than non-musicians, whereas no differences were found between singers and string-players. Regression analyses showed that accumulated musical practice explained about 49% variation in heartbeat perception accuracy in singers but not in string-players. Psychometric data yielded a number of psychologically plausible inter-correlations in musicians related to performance anxiety. However, dispositional traits were not a confounding factor on heartbeat discrimination accuracy. Together, these data provide first evidence indicating that professional musicians show enhanced interoceptive accuracy compared to non-musicians. We argue that musical training largely accounted for this effect.

  15. Evidence for Enhanced Interoceptive Accuracy in Professional Musicians.

    Schirmer-Mokwa, Katharina L; Fard, Pouyan R; Zamorano, Anna M; Finkel, Sebastian; Birbaumer, Niels; Kleber, Boris A

    2015-01-01

    Interoception is defined as the perceptual activity involved in the processing of internal bodily signals. While the ability of internal perception is considered a relatively stable trait, recent data suggest that learning to integrate multisensory information can modulate it. Making music is a uniquely rich multisensory experience that has shown to alter motor, sensory, and multimodal representations in the brain of musicians. We hypothesize that musical training also heightens interoceptive accuracy comparable to other perceptual modalities. Thirteen professional singers, twelve string players, and thirteen matched non-musicians were examined using a well-established heartbeat discrimination paradigm complemented by self-reported dispositional traits. Results revealed that both groups of musicians displayed higher interoceptive accuracy than non-musicians, whereas no differences were found between singers and string-players. Regression analyses showed that accumulated musical practice explained about 49% variation in heartbeat perception accuracy in singers but not in string-players. Psychometric data yielded a number of psychologically plausible inter-correlations in musicians related to performance anxiety. However, dispositional traits were not a confounding factor on heartbeat discrimination accuracy. Together, these data provide first evidence indicating that professional musicians show enhanced interoceptive accuracy compared to non-musicians. We argue that musical training largely accounted for this effect. PMID:26733836

  16. Accuracy of rainfall measurement for scales of hydrological interest

    S. J. Wood

    2000-01-01

    Full Text Available The dense network of 49 raingauges over the 135 km2 Brue catchment in Somerset, England is used to examine the accuracy of rainfall estimates obtained from raingauges and from weather radar. Methods for data quality control and classification of precipitation types are first described. A super-dense network comprising eight gauges within a 2 km grid square is employed to obtain a 'true value' of rainfall against which the 2 km radar grid and a single 'typical gauge' estimate can be compared. Accuracy is assessed as a function of rainfall intensity, for different periods of time-integration (15 minutes, 1 hour and 1 day and for two 8-gauge networks in areas of low and high relief. In a similar way, the catchment gauge network is used to provide the 'true catchment rainfall' and the accuracy of a radar estimate (an area-weighted average of radar pixel values and a single 'typical gauge' estimate of catchment rainfall evaluated as a function of rainfall intensity. A single gauge gives a standard error of estimate for rainfall in a 2 km square and over the catchment of 33% and 65% respectively, at rain rates of 4 mm in 15 minutes. Radar data at 2 km resolution give corresponding errors of 50% and 55%. This illustrates the benefit of using radar when estimating catchment scale rainfall. A companion paper (Wood et al., 2000 considers the accuracy of rainfall estimates obtained using raingauge and radar in combination. Keywords: rainfall, accuracy, raingauge, radar

  17. Analysis of accuracy in optical motion capture - A protocol for laboratory setup evaluation.

    Eichelberger, Patric; Ferraro, Matteo; Minder, Ursina; Denton, Trevor; Blasimann, Angela; Krause, Fabian; Baur, Heiner

    2016-07-01

    Validity and reliability as scientific quality criteria have to be considered when using optical motion capture (OMC) for research purposes. Literature and standards recommend individual laboratory setup evaluation. However, system characteristics such as trueness, precision and uncertainty are often not addressed in scientific reports on 3D human movement analysis. One reason may be the lack of simple and practical methods for evaluating accuracy parameters of OMC. A protocol was developed for investigating the accuracy of an OMC system (Vicon, volume 5.5×1.2×2.0m(3)) with standard laboratory equipment and by means of trueness and uncertainty of marker distances. The study investigated the effects of number of cameras (6, 8 and 10), measurement height (foot, knee and hip) and movement condition (static and dynamic) on accuracy. Number of cameras, height and movement condition affected system accuracy significantly. For lower body assessment during level walking, the most favorable setting (10 cameras, foot region) revealed mean trueness and uncertainty to be -0.08 and 0.33mm, respectively. Dynamic accuracy cannot be predicted based on static error assessments. Dynamic procedures have to be used instead. The significant influence of the number of cameras and the measurement location suggests that instrumental errors should be evaluated in a laboratory- and task-specific manner. The use of standard laboratory equipment makes the proposed procedure widely applicable and it supports the setup process of OCM by simple functional error assessment. Careful system configuration and thorough measurement process control are needed to produce high-quality data. PMID:27230474

  18. Knowing right from wrong in mental arithmetic judgments: calibration of confidence predicts the development of accuracy.

    Rinne, Luke F; Mazzocco, Michèle M M

    2014-01-01

    Does knowing when mental arithmetic judgments are right--and when they are wrong--lead to more accurate judgments over time? We hypothesize that the successful detection of errors (and avoidance of false alarms) may contribute to the development of mental arithmetic performance. Insight into error detection abilities can be gained by examining the "calibration" of mental arithmetic judgments-that is, the alignment between confidence in judgments and the accuracy of those judgments. Calibration may be viewed as a measure of metacognitive monitoring ability. We conducted a developmental longitudinal investigation of the relationship between the calibration of children's mental arithmetic judgments and their performance on a mental arithmetic task. Annually between Grades 5 and 8, children completed a problem verification task in which they rapidly judged the accuracy of arithmetic expressions (e.g., 25 + 50 = 75) and rated their confidence in each judgment. Results showed that calibration was strongly related to concurrent mental arithmetic performance, that calibration continued to develop even as mental arithmetic accuracy approached ceiling, that poor calibration distinguished children with mathematics learning disability from both low and typically achieving children, and that better calibration in Grade 5 predicted larger gains in mental arithmetic accuracy between Grades 5 and 8. We propose that good calibration supports the implementation of cognitive control, leading to long-term improvement in mental arithmetic accuracy. Because mental arithmetic "fluency" is critical for higher-level mathematics competence, calibration of confidence in mental arithmetic judgments may represent a novel and important developmental predictor of future mathematics performance. PMID:24988539

  19. Knowing right from wrong in mental arithmetic judgments: calibration of confidence predicts the development of accuracy.

    Luke F Rinne

    Full Text Available Does knowing when mental arithmetic judgments are right--and when they are wrong--lead to more accurate judgments over time? We hypothesize that the successful detection of errors (and avoidance of false alarms may contribute to the development of mental arithmetic performance. Insight into error detection abilities can be gained by examining the "calibration" of mental arithmetic judgments-that is, the alignment between confidence in judgments and the accuracy of those judgments. Calibration may be viewed as a measure of metacognitive monitoring ability. We conducted a developmental longitudinal investigation of the relationship between the calibration of children's mental arithmetic judgments and their performance on a mental arithmetic task. Annually between Grades 5 and 8, children completed a problem verification task in which they rapidly judged the accuracy of arithmetic expressions (e.g., 25 + 50 = 75 and rated their confidence in each judgment. Results showed that calibration was strongly related to concurrent mental arithmetic performance, that calibration continued to develop even as mental arithmetic accuracy approached ceiling, that poor calibration distinguished children with mathematics learning disability from both low and typically achieving children, and that better calibration in Grade 5 predicted larger gains in mental arithmetic accuracy between Grades 5 and 8. We propose that good calibration supports the implementation of cognitive control, leading to long-term improvement in mental arithmetic accuracy. Because mental arithmetic "fluency" is critical for higher-level mathematics competence, calibration of confidence in mental arithmetic judgments may represent a novel and important developmental predictor of future mathematics performance.

  20. Diagnostic accuracy of magnetic resonance imaging versus computed tomography in stress fractures of the lumbar spine

    Ganiyusufoglu, A.K., E-mail: kursady33@yahoo.co [Department of Radiology, Florence Nightingale Hospital, Istanbul (Turkey); Onat, L. [Department of Radiology, Florence Nightingale Hospital, Istanbul (Turkey); Karatoprak, O.; Enercan, M.; Hamzaoglu, A. [Department of Orthopedics and Traumatology, Florence Nightingale Hospital, Istanbul (Turkey)

    2010-11-15

    Aim: To compare the diagnostic accuracy of magnetic resonance imaging (MRI) with computed tomography (CT) in stress fractures of the lumbar spine. Materials and methods: Radiological and clinical data from 57 adolescents and young adults with a diagnosis of stress injury of the lumbar spine were retrospectively reviewed. All cases had undergone both 1.5 T MRI and 16-section CT examinations. All MRI and CT images were retrospectively reviewed and evaluated in separate sessions. The fracture morphology (complete/incomplete, localization) and vertebral levels were noted at both the CT and MRI examinations. Bone marrow/peri-osseous soft-tissue oedema was also determined at MRI. Results: In total, 73 complete and 32 incomplete stress fractures were detected with CT. Sixty-seven complete, 24 incomplete fractures and eight stress reactions were detected using MRI in the same study group. Marrow oedema was also seen in eight of the complete and 20 of the incomplete fractures. The specificity, sensitivity, and accuracy of MRI in detecting fracture lines were 99.6, 86.7, and 97.2%, respectively. MRI was more accurate at the lower lumbar levels in comparison to upper lumbar levels. Conclusion: MRI has a similar diagnostic accuracy to CT in determining complete fractures with or without accompanying marrow oedema and incomplete fractures with accompanying marrow oedema, especially at the lower lumbar levels, which constitutes 94% of all fractures. At upper lumbar levels and in the incomplete fractures of the pars interarticularis with marked surrounding sclerosis, MRI has apparent limitations compared to CT imaging.

  1. Diagnostic accuracy of magnetic resonance imaging versus computed tomography in stress fractures of the lumbar spine

    Aim: To compare the diagnostic accuracy of magnetic resonance imaging (MRI) with computed tomography (CT) in stress fractures of the lumbar spine. Materials and methods: Radiological and clinical data from 57 adolescents and young adults with a diagnosis of stress injury of the lumbar spine were retrospectively reviewed. All cases had undergone both 1.5 T MRI and 16-section CT examinations. All MRI and CT images were retrospectively reviewed and evaluated in separate sessions. The fracture morphology (complete/incomplete, localization) and vertebral levels were noted at both the CT and MRI examinations. Bone marrow/peri-osseous soft-tissue oedema was also determined at MRI. Results: In total, 73 complete and 32 incomplete stress fractures were detected with CT. Sixty-seven complete, 24 incomplete fractures and eight stress reactions were detected using MRI in the same study group. Marrow oedema was also seen in eight of the complete and 20 of the incomplete fractures. The specificity, sensitivity, and accuracy of MRI in detecting fracture lines were 99.6, 86.7, and 97.2%, respectively. MRI was more accurate at the lower lumbar levels in comparison to upper lumbar levels. Conclusion: MRI has a similar diagnostic accuracy to CT in determining complete fractures with or without accompanying marrow oedema and incomplete fractures with accompanying marrow oedema, especially at the lower lumbar levels, which constitutes 94% of all fractures. At upper lumbar levels and in the incomplete fractures of the pars interarticularis with marked surrounding sclerosis, MRI has apparent limitations compared to CT imaging.

  2. Assessing the Temporal Stability of the Accuracy of a Time Series of Burned Area Products

    Marc Padilla

    2014-03-01

    Full Text Available Temporal stability, defined as the change of accuracy through time, is one of the validation aspects required by the Committee on Earth Observation Satellites’ Land Product Validation Subgroup. Temporal stability was evaluated for three burned area products: MCD64, Globcarbon, and fire_cci. Traditional accuracy measures, such as overall accuracy and omission and commission error ratios, were computed from reference data for seven years (2001–2007 in seven study sites, located in Angola, Australia, Brazil, Canada, Colombia, Portugal, and South Africa. These accuracy measures served as the basis for the evaluation of temporal stability of each product. Nonparametric tests were constructed to assess different departures from temporal stability, specifically a monotonic trend in accuracy over time (Wilcoxon test for trend, and differences in median accuracy among years (Friedman test. When applied to the three burned area products, these tests did not detect a statistically significant temporal trend or significant differences among years, thus, based on the small sample size of seven sites, there was insufficient evidence to claim these products had temporal instability. Pairwise Wilcoxon tests comparing yearly accuracies provided a measure of the proportion of year-pairs with significant differences and these proportions of significant pairwise differences were in turn used to compare temporal stability between BA products. The proportion of year-pairs with different accuracy (at the 0.05 significance level ranged from 0% (MCD64 to 14% (fire_cci, computed from the 21 year-pairs available. In addition to the analysis of the three real burned area products, the analyses were applied to the accuracy measures computed for four hypothetical burned area products to illustrate the properties of the temporal stability analysis for different hypothetical scenarios of change in accuracy over time. The nonparametric tests were generally successful at

  3. Accuracy of Orthomosaic Generated by Different Methods in Example of UAV Platform MUST Q

    Liba, N.; Berg-Jürgens, J.

    2015-11-01

    Development of photogrammetry has reached a new level due to the use of unmanned aerial vehicles (UAV). In Estonia, the main areas of use of UAVs are monitoring overhead power lines for energy companies and fields in agriculture, and estimating the use of stockpile in mining. The project was carried out by the order of the City of Tartu for future road construction. In this research, automation of UAV platform MUST Q aerial image processing and reduction of time spent on the use of ground control points (GCP) is studied. For that two projects were created with software Pix4D. First one was processed automatically without GCP. Second one did use GCP, but all the processing was done automatically. As the result of the project, two orthomosaics with the pixel size of 5 cm were composed. Projects allowed ensuring accuracy limit of three times of the pixel size. The project that turned out to be the most accurate was the one using ground control points to do the levelling, which remained within the error limit allowed and the accuracy of the orthomosaic was 0.132 m. The project that didn't use ground control points had the accuracy of 1.417 m.

  4. Relationships between postural balance, rifle stability and shooting accuracy among novice rifle shooters.

    Mononen, K; Konttinen, N; Viitasalo, J; Era, P

    2007-04-01

    The present study examined the relationships between shooting accuracy and shooters' behavioral performance, i.e., postural balance and gun barrel stability, among novice rifle shooters in intra- and inter-individual levels. Postural balance and rifle stability were assessed in terms of anteroposterior (VEL(AP)) and mediolateral (VEL(ML)) sway velocity of the movement of center of pressure, and horizontal (DEV(H)) and vertical (DEV(V)) deviation of the aiming point. The participants (n=58) performed 30 shots in the standing position at a distance of 10 m from the target. The data showed that shooting accuracy was related to postural balance and rifle stability, but only at the inter-individual level. The correlation coefficients between shooting score and behavioral performance variables ranged from -0.29 to -0.45. The stepwise multiple regression analysis revealed that the VEL(ML) and the DEV(H) as independent variables accounted for 26% of the variance in the shooting score. The results also suggested that postural balance is related to the shooting accuracy both directly and indirectly through rifle stability. As the role of postural balance appeared to be important in shooting performance, the use of additional balance training programs to improve a shooter's postural skills should be encouraged. PMID:17394480

  5. Diagnostic Accuracy of Pleural Fluid Soluble Interleukin 2 Receptor in Patients

    Kourosh Shahraki

    2014-04-01

    Full Text Available Background: Pleural tuberculosis occurs in 4% of newly diagnosed cases of tuberculosis. T-cells have an important role on the immunity against mycobacterial infections and as a result, the level of soluble interleukin 2 receptors (SIL-2R as a marker of T-cell activation is elevated in patients with tuberculous pleural effusion. Materials and Methods: In this cross sectional study, the diagnostic accuracy of SIL-2R level was assessed in separating tuberculous from non- tuberculous effusions in Zahedan, Iran. From 112 patients fulfilled entrance criteria for exudative pleural effusion, 88 patients were included and underwent diagnostic procedures to identify the origin of pleural effusion. The SIL-2R was evaluated at various cut-off levels by nonparametric receiver operating characteristic (ROC curve, and values affording greatest diagnostic accuracy were selected. Results: SIL-2R level in TB group was 9147±3573 while this level in non-TB group was 2724±1326 and the difference was statistically significant (p=0.001. The cut-off point in our study was 4200 U/ml and the area under curve was 0.930 with 95% CI: 0.881–0.979 (p=0.001. The sensitivity and specificity for this level is 86 and 89%. Conclusion: Several factors lead to the variation in the level and cut-off point of SIL-2R in different regions. Our cut-off point was lower than other studies. The level of SIL-2R in patients with tuberculosis is significantly higher than parapneumonic effusions. We suggest that measuring the SIL-2R level in pleural fluid of tuberculous patients is a useful diagnostic tool in diagnosing tuberculous pleural effusion.

  6. Diagnostic accuracy of mammography readers and their memory performance have no correlation with each other

    Full text: The study aims to determine if any association exists between visual memory performance and diagnostic accuracy performance in a group of radiologist mammogram readers. Materials and Methods: One hundred proven mammograms (23 with cancers) were grouped into 5 sets of 20 cases, with sets being of equal difficulty. Pairs of sets were presented in 5 reads (40 cases per read, order random) to a panel of 8 radiologist readers (either present or past screening readers, with experience range from 20 years). The readers were asked to either 'clear' or 'call back' cases depending on need for further workup, and at post-baseline reads to indicate whether each case was 'new' or 'old' (i .e. remembered from prior read). Two sets were presented only at baseline (40 cases per reader), and were used to calculate the reader's false recollection rate. Three sets were repeated post-baseline once or twice (100 cases per reader). Reading conditions were standardised. Results: Memory performance differed markedly between readers. The number of correctly remembered cases (of 100 'old' cases) had a median of 10.5 and range of 0-58. The observed number of false recollections (of 40 'totally new' cases) had a median of 2 and range of 0-17. Diagnostic performance measures were mean (range): sensitivity 0.68 (0.54-0.81); specificity 0.82 (0.74-0.91); positive predictive value (PPV) 0.55 (0.500.65); negative predictive value (NPV) 0.89 (0.86-0.93) and accuracy 0.78 (0.76-0.83). Confidence intervals (CIs; 95%) for each reader overlapped for all the diagnostic parameters, indicating a lack of statistically significant difference between the readers at the 5% level. The most sensitive and the most specific reader showed a trend away from each other on sensitivity, specificity, NPV and PPV; their accuracies were 0.76 and 0.82, respectively, and their accuracy 95% CIs overlapped considerably. Correlation analysis by reader showed no association between observed memory performance and

  7. The impact of the cycle counting in the inventory accuracy: multiple cases in industries of Paraná

    Everton Drohomeretski

    2013-05-01

    Full Text Available This article aims to identify the impact of cycle counting on inventory accuracy. Multiple case studies were used as research method; these include seven case studies of companies in Paraná. A research protocol was used as the basis for collecting the data. For the data analysis, the content analysis method was used with the triangulation of collected data. For the main results, the study demonstrates the relationship between cycle counting, the level of importance attributed by the organization, the number of items and the rate of accuracy obtained. The high level of control of inventory processes, together with the use of cycle counting made it possible to eliminate the main cause of failure in inventory accuracy – errors in recording the movement of material – and with this, improve the operational efficiency of the companies.

  8. The evaluation of accuracy of NAA method used by P2TRR laboratory with food standard reference material analysis

    The NAA method is the analysis method with high precision and accuracy level. The precision and accuracy of NAA laboratory in P2TRR had been evaluated with SRM 1573a Tomato Leaf and CRM No.9 Sargasso. Samples were irradiated in RSG-GAS's rabbit system and counted with gamma spectrometry. The results obtained from this research are for the SRM 1573a sample the test could analyze 17 elements of the 40 certified elements, and for CRM No.9 sample the test could analyze 16 elements of the 30 certified elements. The result of quantitative analysis indicate the different deviation of each element between 2 -10.5 % compared to the certificate data. This deviation value <15%, this value shows that the precision and accuracy level is good enough

  9. The Relationship Between Clinicians' Confidence and Accuracy, and the Influence of Child Characteristics, in the Screening of Autism Spectrum Disorder.

    Hedley, Darren; Brewer, Neil; Nevill, Rose; Uljarević, Mirko; Butter, Eric; Mulick, James A

    2016-07-01

    The study examined the confidence accuracy relationship, and the influence of child characteristics on clinician confidence, when predicting a diagnosis of Autism Spectrum Disorder during screening of 125 referred children aged under 3.5 years. The diagnostic process included observation, interview, language and developmental testing. Clinical judgement accuracy was compared against final diagnosis for high and low confidence levels (with confidence assessed on a 0-100 % scale). We identified a significant CA relationship with predictive accuracy highest at confidence levels of 90-100 %. Parent report of unusual behaviors was the only significant independent predictor of confidence. Clinicians' confidence may be important when evaluating decisions to refer, or not to refer, children for further diagnostic assessment. PMID:26975451

  10. Geometric accuracy of wax bade models manufactured in silicon moulds

    G. Budzik

    2010-01-01

    Full Text Available The article presents the test results of the geometric accuracy of wax blade models manufactured in silicon moulds in the Rapid Tooling process, with the application of the Vacuum Casting technology. In batch production casting waxes are designed for the manufacture of models and components of model sets through injection into a metal die. The objective of the tests was to determine the possibility of using traditional wax for the production of casting models in the rapid prototyping process. Blade models made of five types of casting wax were measured. The definition of the geometric accuracy of wax blade models makes it possible to introduce individual modifications aimed at improving their shape in order to increase the dimensional accuracy of blade models manufactured in the rapid prototyping process.

  11. THE ACCURACY OF GENERAL GOVERNMENT BALANCE FORECASTS IN ROMANIA

    Mihaela SIMIONESCU

    2015-03-01

    Full Text Available Economic forecasts are an essential building block for a budgetary anticipation in order to determine the budgetary objectives and to sustain the tax and expenditure plans. In Romania the surveillance process is ensured by the use of budget programs. The aim of this paper is to improve the budgetary planning by recommending the use of the forecasted general budget balance provided by the institution with the highest accuracy during the crisis (2008-2013. More types of projections were analyzed during the recent economic crisis and the IMF forecasts for this indicator outperformed those provided by Dobrescu model and the European Union. Therefore, the recommendation is related to the use of IMF predictions in establishing the next budgetary plan for 2014 and 2015. Moreover, this research also brings improvements in the methodological framework, by proposing some aggregated accuracy indicators (S1, S2, S3 and S measures for solving the problem of contradictory results of different accuracy indicators.

  12. Classification accuracy analyses using Shannon’s Entropy

    Shashi Poonam Indwar

    2014-11-01

    Full Text Available There are many methods for determining the Classification Accuracy. In this paper significance of Entropy of training signatures in Classification has been shown. Entropy of training signatures of the raw digital image represents the heterogeneity of the brightness values of the pixels in different bands. This implies that an image comprising a homogeneous lu/lc category will be associated with nearly the same reflectance values that would result in the occurrence of a very low entropy value. On the other hand an image characterized by the occurrence of diverse lu/lc categories will consist of largely differing reflectance values due to which the entropy of such image would be relatively high. This concept leads to analyses of classification accuracy. Although Entropy has been used many times in RS and GIS but its use in determination of classification accuracy is new approach.

  13. Accuracy of reactivity predictions for the MARIA reactor

    The high flux water cooled, beryllium moderated reactor MARIA at the Institute of Atomic Energy in Poland is used mainly as a source of neutrons for neutronography, solid state physics and for irradiation of isotopes and materials. Introduction of new fuel is planned, which makes particularly important the accuracy of computational reactivity predictions. The complicated geometry of the MARIA reactor core makes the problem of accuracy difficult to solve. The prerequisite of MARIA reactivity calculations is the determination of the quantities of He-3 and Li-6 for each beryllium block. Authors have discussed this aspect at Kranjska Gora 2002. In the present paper accuracy obtained with different core model simplifications is discussed. The codes REBUS, TRITAC and MCNP have been used for that purpose. The results of computations are compared with measurement on two critical assemblies. The computational scheme has been used to calculate reactivity effect of the new fuel. (author)

  14. Accuracy of Loopy belief propagation in Gaussian models.

    Nishiyama, Yu; Watanabe, Sumio

    2009-05-01

    This paper considers the loopy belief propagation (LBP) algorithm applied to Gaussian graphical models. It is known for Gaussian belief propagation that, if LBP converges, LBP computes the exact posterior means but incorrect variances. In this paper, we analytically derive the posterior variances for some special structured graphs and clarify the accuracy of LBP. For the graphs of a single cycle, we derive a rigorous solution for the posterior variances and thereby find the quantity that determines the accuracy of LBP. Based on this result, we state a necessary condition for LBP convergence. The quantity above also plays an important role in graphs of a single cycle with arbitrary trees. For arbitrary topological graphs, we consider the situation where correlations between any pair of nodes are comparatively small and show analytically the principal values that determine the accuracy of LBP. PMID:19243911

  15. Follow your breath: respiratory interoceptive accuracy in experienced meditators.

    Daubenmier, Jennifer; Sze, Jocelyn; Kerr, Catherine E; Kemeny, Margaret E; Mehling, Wolf

    2013-08-01

    Attention to internal bodily sensations is a core feature of mindfulness meditation. Previous studies have not detected differences in interoceptive accuracy between meditators and nonmeditators on heartbeat detection and perception tasks. We compared differences in respiratory interoceptive accuracy between meditators and nonmeditators in the ability to detect and discriminate respiratory resistive loads and sustain accurate perception of respiratory tidal volume during nondistracted and distracted conditions. Groups did not differ in overall performance on the detection and discrimination tasks; however, meditators were more accurate in discriminating the resistive load with the lowest ceiling effect. Meditators were also more accurate during the nondistracted tracking task at a lag time of 1 s following the breath. Results provide initial support for the notion that meditators have greater respiratory interoceptive accuracy compared to nonmeditators. PMID:23692525

  16. The predictive accuracy of intertemporal-choice models.

    Arfer, Kodi B; Luhmann, Christian C

    2015-05-01

    How do people choose between a smaller reward available sooner and a larger reward available later? Past research has evaluated models of intertemporal choice by measuring goodness of fit or identifying which decision-making anomalies they can accommodate. An alternative criterion for model quality, which is partly antithetical to these standard criteria, is predictive accuracy. We used cross-validation to examine how well 10 models of intertemporal choice could predict behaviour in a 100-trial binary-decision task. Many models achieved the apparent ceiling of 85% accuracy, even with smaller training sets. When noise was added to the training set, however, a simple logistic-regression model we call the difference model performed particularly well. In many situations, between-model differences in predictive accuracy may be small, contrary to long-standing controversy over the modelling question in research on intertemporal choice, but the simplicity and robustness of the difference model recommend it to future use. PMID:25773127

  17. Accuracy and pitfalls of I-131-β-iodomethylnorcholesterol (NP-59) scintigraphy

    This paper reports a rigorous assessment of I-131 β-iodomethylnorcholesterol (NP-59) adrenal scintigraphy performed in 108 consecutive cases (1982-1985) with correlative clinical, biochemical, radiographic, and pathologic data. Accuracy ranged from 71% in primary aldosteronism and 75% in euadrenal tumors to 100% in cases of Cushing syndrome and hyperandrogenism. More than in most nuclear medicine studies, the accuracy of NP-59 image interpretation requires the fulfillment of clear clinical, biochemical, and radiographic criteria, such as those the authors have defined. High image interpretation reproducibility was demonstrated by the exchange of 20 random cases, with another institution. Responses of 85 of 126 institutions to questionnaires revealed the high safety level of this radiopharmaceutical

  18. Accuracy of X-ray fluorescence spectrometric determination of Rb and Sr concentrations in rock samples

    It is shown that application of the Compton scattering for matrix correction in the X-ray fluorescence spectrometric determination of the trace elements Rb and Sr in rock samples can provide concentrations at a relative accuracy level of 1%. The empirical method applies to rock samples showing differences in mass absorption up to a factor of two. The accuracy of the method has been tested by analysis of 57 samples analysed for Rb and Sr by mass spectrometric isotope dilution. In addition a few of the U.S. Geological Survey reference rock powders, showing significantly different mass absorption, were analysed for Rb and Sr. It is demonstrated that the mica effect, if significant, is smaller than 1% relative. There is no advantage in the use of the LiF(220) analysing crystal as a substitute for the LiF(200). The method appears to be insensitive to the pellet thickness. (author)

  19. On the accuracy of the Padé-resummed master equation approach to dissipative quantum dynamics.

    Chen, Hsing-Ta; Berkelbach, Timothy C; Reichman, David R

    2016-04-21

    Well-defined criteria are proposed for assessing the accuracy of quantum master equations whose memory functions are approximated by Padé resummation of the first two moments in the electronic coupling. These criteria partition the parameter space into distinct levels of expected accuracy, ranging from quantitatively accurate regimes to regions of parameter space where the approach is not expected to be applicable. Extensive comparison of Padé-resummed master equations with numerically exact results in the context of the spin-boson model demonstrates that the proposed criteria correctly demarcate the regions of parameter space where the Padé approximation is reliable. The applicability analysis we present is not confined to the specifics of the Hamiltonian under consideration and should provide guidelines for other classes of resummation techniques. PMID:27389208

  20. Accuracy and qualities of real and suggested memories: nonspecific age differences.

    Karpel, M E; Hoyer, W J; Toglia, M P

    2001-03-01

    This study examined adult age differences in the accuracy, confidence ratings, and vividness ratings of veridical and suggested memories. After seeing either one or two exposures of a vignette depicting a theft, young adults (M = 19 years) and older adults (M = 73 years) were given misleading information that suggested the presence of particular objects in the episode. Memory accuracy was higher for younger adults than for older adults, and the frequency of falsely reporting the presence of suggested objects was greater for older adults than for young adults. Further, levels of confidence and vividness ratings of the perceptual attributes (colors, locations) of falsely recognized items were higher for older adults than for young adults. Both young adults and older adults used more perceptual references when describing veridical memories than when describing suggested memories. Age differences in the suggestibility of memory were attributed to nonspecific or nondissociated memory aging effects. PMID:11245357

  1. Accuracy of the Bethe approximation for hyperparameter estimation in probabilistic image processing

    We investigate the accuracy of statistical-mechanical approximations for the estimation of hyperparameters from observable data in probabilistic image processing, which is based on Bayesian statistics and maximum likelihood estimation. Hyperparameters in statistical science correspond to interactions or external fields in the statistical-mechanics context. In this paper, hyperparameters in the probabilistic model are determined so as to maximize a marginal likelihood. A practical algorithm is described for grey-level image restoration based on a Gaussian graphical model and the Bethe approximation. The algorithm corresponds to loopy belief propagation in artificial intelligence. We examine the accuracy of hyperparameter estimation when we use the Bethe approximation. It is well known that a practical algorithm for probabilistic image processing can be prescribed analytically when a Gaussian graphical model is adopted as a prior probabilistic model in Bayes' formula. We are therefore able to compare, in a numerical study, results obtained through mean-field-type approximations with those based on exact calculation

  2. Accuracy required and achievable in radiotherapy dosimetry: have modern technology and techniques changed our views?

    Thwaites, David

    2013-06-01

    In this review of the accuracy required and achievable in radiotherapy dosimetry, older approaches and evidence-based estimates for 3DCRT have been reprised, summarising and drawing together the author's earlier evaluations where still relevant. Available evidence for IMRT uncertainties has been reviewed, selecting information from tolerances, QA, verification measurements, in vivo dosimetry and dose delivery audits, to consider whether achievable uncertainties increase or decrease for current advanced treatments and practice. Overall there is some evidence that they tend to increase, but that similar levels should be achievable. Thus it is concluded that those earlier estimates of achievable dosimetric accuracy are still applicable, despite the changes and advances in technology and techniques. The one exception is where there is significant lung involvement, where it is likely that uncertainties have now improved due to widespread use of more accurate heterogeneity models. Geometric uncertainties have improved with the wide availability of IGRT.

  3. Computational efficiency and accuracy of the fission collision separation method in 3D HTTR benchmark problems

    A fission collision separation method has been recently developed to significantly improve the computational efficiency of the COMET response coefficient generator. In this work, the accuracy and efficiency of the new response coefficient generation method is tested in 3D HTTR benchmark problems at both lattice and core levels. In lattice calculations, the surface-to-surface and fission density response coefficients computed by the new method are compared with those directly calculated by the Monte Carlo method. In whole core calculations, the eigenvalues and bundle/pin fission densities predicated by COMET based on the response coefficient libraries generated by the fission collision separation method are compared with those based on the interpolation method as well as the Monte Carlo reference solutions. These comparisons have shown that the new response coefficient generation method is significantly (about 3 times) faster than the interpolations method while its accuracy is close to that of the interpolation method. (author)

  4. Investigation on Accuracies of Real Time Kinematic GPS for GIS Applications

    Cetin Mekik

    2009-03-01

    Full Text Available People specialised in or in contact with Geographic Information Systems (GIS at administrative or user level have been looking for economical and productive means for data acquisition tasks since the advent of GIS. Because the data acquisition constitutes major part of any GIS, scientific community, especially geodetic surveyors, have come up with a solution of real time kinematic (RTK GPS. This paper investigates the performance (internal and external accuracy of RTK GPS. For this purpose, two separate tests are conducted. In the first test three cases are taken in consideration for internal accuracy, namely, identical satellite configuration, different satellite configuration and different reference station. In the second test, two cases are put into study in which RTK GPS results are compared with static GPS and conventional terrestrial method. The results from all the tests have proved that this modern technique is very much suitable for data acquisition of GIS’s as well as it is efficient and economical.

  5. Accuracy of prognosis estimates by four palliative care teams: a prospective cohort study

    Costantini Massimo

    2002-03-01

    Full Text Available Abstract Background Prognosis estimates are used to access services, but are often inaccurate. This study aimed to determine the accuracy of giving a prognosis range. Methods and measurements A prospective cohort study in four multi-professional palliative care teams in England collected data on 275 consecutive cancer referrals who died. Prognosis estimates (minimum – maximum at referral, patient characteristics, were recorded by staff, and later compared with actual survival. Results Minimum survival estimates ranged Conclusions Offering a prognosis range has higher levels of accuracy (about double than traditional estimates, but is still very often inaccurate, except very close to death. Where possible clinicians should discuss scenarios with patients, rather than giving a prognosis range.

  6. EFFECT OF DIGITAL FRINGE PROJECTION PARAMETERS ON 3D RECONSTRUCTION ACCURACY

    A. Babaei

    2013-09-01

    This paper aims to evaluate different parameters which affect the accuracy of the final results. For this purpose, some test were designed and implemented. These tests assess the number of phase shifts, spatial frequency of the fringe pattern, light condition, noise level of images, and the color and material of target objects on the quality of resulted phase map. The evaluation results demonstrate that digital fringe projection method is capable of obtaining depth map of complicated object with high accuracy. The contrast test results showed that this method is able to work under different ambient light condition; although at places with high light condition will not work properly. The results of implementation on different objects with various materials, color and shapes demonstrate the high capability of this method of 3D reconstruction.

  7. Accuracy and Consistency of Respiratory Gating in Abdominal Cancer Patients

    Purpose: To evaluate respiratory gating accuracy and intrafractional consistency for abdominal cancer patients treated with respiratory gated treatment on a regular linear accelerator system. Methods and Materials: Twelve abdominal patients implanted with fiducials were treated with amplitude-based respiratory-gated radiation therapy. On the basis of daily orthogonal fluoroscopy, the operator readjusted the couch position and gating window such that the fiducial was within a setup margin (fiducial-planning target volume [f-PTV]) when RPM indicated “beam-ON.” Fifty-five pre- and post-treatment fluoroscopic movie pairs with synchronized respiratory gating signal were recorded. Fiducial motion traces were extracted from the fluoroscopic movies using a template matching algorithm and correlated with f-PTV by registering the digitally reconstructed radiographs with the fluoroscopic movies. Treatment was determined to be “accurate” if 50% of the fiducial area stayed within f-PTV while beam-ON. For movie pairs that lost gating accuracy, a MATLAB program was used to assess whether the gating window was optimized, the external-internal correlation (EIC) changed, or the patient moved between movies. A series of safety margins from 0.5 mm to 3 mm was added to f-PTV for reassessing gating accuracy. Results: A decrease in gating accuracy was observed in 44% of movie pairs from daily fluoroscopic movies of 12 abdominal patients. Three main causes for inaccurate gating were identified as change of global EIC over time (∼43%), suboptimal gating setup (∼37%), and imperfect EIC within movie (∼13%). Conclusions: Inconsistent respiratory gating accuracy may occur within 1 treatment session even with a daily adjusted gating window. To improve or maintain gating accuracy during treatment, we suggest using at least a 2.5-mm safety margin to account for gating and setup uncertainties

  8. Achieving seventh-order amplitude accuracy in leapfrog integrations

    Williams, Paul

    2015-04-01

    The leapfrog time-stepping scheme is commonly used in general circulation models of weather and climate. The Robert-Asselin filter is used in conjunction with it, to damp the computational mode. Although the leapfrog scheme makes no amplitude errors when integrating linear oscillations, the Robert-Asselin filter introduces first-order amplitude errors. The RAW filter, which was recently proposed as an improvement, eliminates the first-order amplitude errors and yields third-order amplitude accuracy. This development has been shown to significantly increase the skill of medium-range weather forecasts. However, it has not previously been shown how to further improve the accuracy by eliminating the third- and higher-order amplitude errors. This presentation will show that leapfrogging over a suitably weighted blend of the filtered and unfiltered tendencies eliminates the third-order amplitude errors and yields fifth-order amplitude accuracy. It will also show that the use of a more discriminating (1,-4,6,-4,1) filter instead of a (1,-2,1) filter eliminates the fifth-order amplitude errors and yields seventh-order amplitude accuracy. Other related schemes are obtained by varying the values of the filter parameters, and it is found that several combinations offer an appealing compromise of stability and accuracy. The proposed new schemes are shown to yield substantial forecast improvements in a medium-complexity atmospheric general circulation model. They appear to be attractive alternatives to the filtered leapfrog schemes currently used in many weather and climate models. Reference Williams PD (2013) Achieving seventh-order amplitude accuracy in leapfrog integrations. Monthly Weather Review 141(9), pp 3037-3051. DOI: 10.1175/MWR-D-12-00303.1

  9. Contributions of speed and accuracy to translational selection in bacteria.

    Wenqi Ran

    Full Text Available Among bacteria, we have previously shown that species that are capable of rapid growth have stronger selection on codon usage than slow growing species, and possess higher numbers of rRNA and tRNA genes. This suggests that fast-growers are adapted for fast protein synthesis. There is also considerable evidence that codon usage is influenced by accuracy of translation, and some authors have argued that accuracy is more important than speed. Here we compare the strength of the two effects by studying the codon usages in high and low expression genes and on conserved and variable sites within high expression genes. We introduce a simple statistical method that can be used to assess the significance and the strength of the two types of bias in the same sets of sequences. We compare our statistical measure of codon bias to the common used codon adaptation index, and show that the new measure is preferable for three reasons for the purposes of this analysis. Across a large sample of bacterial genomes, both effects from speed and accuracy are clearly visible, although the speed effect appears to be much stronger than the accuracy effect and is found to be significant in a larger proportion of genomes. It is also difficult to explain the correlation of codon bias in the high expression genes with growth rates and numbers of copies of tRNA and rRNA genes on the basis of selection for accuracy. Hence we conclude that selection for translational speed is a dominant effect in driving codon usage bias in fast-growing bacteria, with selection for accuracy playing a small supplementary role.

  10. Submicron accuracy optimization for laser beam soldering processes

    Beckert, Erik; Burkhardt, Thomas; Hornaff, Marcel; Kamm, Andreas; Scheidig, Ingo; Stiehl, Cornelia; Eberhardt, Ramona; Tünnermann, Andreas

    2010-02-01

    Laser beam soldering is a packaging technology alternative to polymeric adhesive bonding in terms of stability and functionality. Nevertheless, when packaging especially micro optical and MOEMS systems this technology has to fulfil stringent requirements for accuracy in the micron and submicron range. Investigating the assembly of several laser optical systems it has been shown that micron accuracy and submicron reproducibility can be reached when using design-of-experiment optimized solder processes that are based on applying liquid solder drops ("Solder Bumping") onto wettable metalized joining surfaces of optical components. The soldered assemblies were subject to thermal cycles and vibration/ shock test also.

  11. Accuracy Improvement in Magnetic Field Modeling for an Axisymmetric Electromagnet

    Ilin, Andrew V.; Chang-Diaz, Franklin R.; Gurieva, Yana L.; Il,in, Valery P.

    2000-01-01

    This paper examines the accuracy and calculation speed for the magnetic field computation in an axisymmetric electromagnet. Different numerical techniques, based on an adaptive nonuniform grid, high order finite difference approximations, and semi-analitical calculation of boundary conditions are considered. These techniques are being applied to the modeling of the Variable Specific Impulse Magnetoplasma Rocket. For high-accuracy calculations, a fourth-order scheme offers dramatic advantages over a second order scheme. For complex physical configurations of interest in plasma propulsion, a second-order scheme with nonuniform mesh gives the best results. Also, the relative advantages of various methods are described when the speed of computation is an important consideration.

  12. Measurement system with high accuracy for laser beam quality.

    Ke, Yi; Zeng, Ciling; Xie, Peiyuan; Jiang, Qingshan; Liang, Ke; Yang, Zhenyu; Zhao, Ming

    2015-05-20

    Presently, most of the laser beam quality measurement system collimates the optical path manually with low efficiency and low repeatability. To solve these problems, this paper proposed a new collimated method to improve the reliability and accuracy of the measurement results. The system accuracy controlled the position of the mirror to change laser beam propagation direction, which can realize the beam perpendicularly incident to the photosurface of camera. The experiment results show that the proposed system has good repeatability and the measuring deviation of M2 factor is less than 0.6%. PMID:26192526

  13. Design target accuracies, data uncertainties and sensitivity studies

    The aim of this course is to give an overview of the general problem of design parameter target accuracy assessment, the related data needs and the uncertainty analysis techniques which provide the tools for these studies. Concerning target accuracy assessment, this paper is essentially based on a paper, related to LMFBR's. Data needs will be illustrated by the example of fission data needs, in all the fields of core design and fuel cycle. Uncertainty analysis is a general notion which covers different fields. In this paper we will essentially describe the so-called data adjustment aspect. Finally, the sensitivity methods, based on perturbation theory will be described for different type of applications

  14. Ultrafast High Accuracy PCRTM_SOLAR Model for Cloudy Atmosphere

    Yang, Qiguang; Liu, Xu; Wu, Wan; Yang, Ping; Wang, Chenxi

    2015-01-01

    An ultrafast high accuracy PCRTM_SOLAR model is developed based on PCA compression and principal component-based radiative transfer model (PCRTM). A fast algorithm for simulation of multi-scattering properties of cloud and/or aerosols is integrated into the fast infrared PCRTM. We completed radiance simulation and training for instruments, such as IASI, AIRS, CrIS, NASTI and SHIS, under diverse conditions. The new model is 5 orders faster than 52-stream DISORT with very high accuracy for cloudy sky radiative transfer simulation. It is suitable for hyperspectral remote data assimilation and cloudy sky retrievals.

  15. Multimodal Biometric Systems - Study to Improve Accuracy and Performance

    Sasidhar, K; Ramakrishna, Kolikipogu; KailasaRao, K

    2010-01-01

    Biometrics is the science and technology of measuring and analyzing biological data of human body, extracting a feature set from the acquired data, and comparing this set against to the template set in the database. Experimental studies show that Unimodal biometric systems had many disadvantages regarding performance and accuracy. Multimodal biometric systems perform better than unimodal biometric systems and are popular even more complex also. We examine the accuracy and performance of multimodal biometric authentication systems using state of the art Commercial Off- The-Shelf (COTS) products. Here we discuss fingerprint and face biometric systems, decision and fusion techniques used in these systems. We also discuss their advantage over unimodal biometric systems.

  16. Accuracy evaluation of airborne stereo line imager data

    Gibson, J. R.; Chapman, M. A.

    The accuracy of the corrected imagery from a pushbroom stereo line imager is evaluated. The line imager system consists of the MIES II imaging system, an auxiliary data system, and a postflight data-processing system. The imagery and navigation data are tied to ground control points by a photogrammetric bundle adjustment to resolve low-frequency position errors. The accuracy of the correct imagery was found to be 1.5 pixels rms in position and 0.5 pixels rms in height.

  17. Accuracy of transferring microparts in a multi stage former

    Mahshid, Rasoul; Hansen, Hans Nørgaard; Arentoft, Mogens

    2013-01-01

    Many fasteners used in electromechanical systems are micro metal parts which should be manufactured with high accuracy and reliability and in large quantities. Micro forming is promising to fulfill these demands. This research focuses on investigating a gripping unit in a multi stage former, as the...... and the second one is intended to depict how the unit transfers the parts with different diameters with respect to the front profile of the fingers. The experiments showed that the manipulator can handle the parts with 7 μm accuracy, 2 μm reproducibility and 9μm uncertainty for a 20mm distance between...

  18. Subpixel accuracy for extracting groove center based on corner detection

    Liu Suyi; Wang Guorong; Shi Yonghua

    2006-01-01

    Subpixel accuracy for V-groove center in robot welding is researched and a software measure to increase the accuracy of seam tracking by laser is presented.LOG( Laplacian of Gaussian ) operator is adopted to detect image edge.Vgroove center is extracted by corner detection of extremum curvature.Subpixel position is obtained by Lagarange polynomial interpolation algorithm.Experiment results show that the method is brief and applied, and is sufficient for the real time of robot welding by laser sensors.

  19. Emotional state and its impact on voice authentication accuracy

    Voznak, Miroslav; Partila, Pavol; Penhaker, Marek; Peterek, Tomas; Tomala, Karel; Rezac, Filip; Safarik, Jakub

    2013-05-01

    The paper deals with the increasing accuracy of voice authentication methods. The developed algorithm first extracts segmental parameters, such as Zero Crossing Rate, the Fundamental Frequency and Mel-frequency cepstral coefficients from voice. Based on these parameters, the neural network classifier detects the speaker's emotional state. These parameters shape the distribution of neurons in Kohonen maps, forming clusters of neurons on the map characterizing a particular emotional state. Using regression analysis, we can calculate the function of the parameters of individual emotional states. This relationship increases voice authentication accuracy and prevents unjust rejection.

  20. Accuracy and Reliability of a New Tennis Ball Machine

    Cyril Brechbuhl, Grégoire Millet, Laurent Schmitt

    2016-01-01

    The aim was to evaluate the reliability of a newly-developed ball machine named 'Hightof', on the field and to assess its accuracy. The experiment was conducted in the collaboration of the 'Hawk-Eye' technology. The accuracy and reliability of this ball machine were assessed during an incremental test, with 1 min of exercise and 30 sec of recovery, where the frequency of the balls increased from 10 to 30 balls·min-1. The initial frequency was 10 and increased by 2 until 22, then by 1 until 30...

  1. Accuracy of helium accumulation fluence monitor for fast reactor dosimetry

    Ito, Chikara; Aoyama, Takafumi [Power Reactor and Nuclear Fuel Development Corp., Oarai, Ibaraki (Japan). Oarai Engineering Center

    1998-03-01

    A helium (He) accumulation fluence monitor (HAFM) has been developed for fast reactor dosimetry. In order to evaluate the measurement accuracy of neutron fluence by the HAFM method, the HAFMs of enriched boron (B) and beryllium (Be) were irradiated in the Fast Neutron Source Reactor `YAYOI`. The number of He atoms produced in the HAFMs were measured and compared with the calculated values. As a result of this study, it was confirmed that the neutron fluence could be measured within 5 % by the HAFM method, and that met the required accuracy for fast reactor dosimetry. (author)

  2. ACCURACY OF A 3D VISION SYSTEM FOR INSPECTION

    Carmignato, Simone; Savio, Enrico; De Chiffre, Leonardo

    ABSTRACT. This paper illustrates an experimental method to assess the accuracy of a three-dimensional (3D) vision system for the inspection of complex geometry. The aim is to provide a procedure to evaluate task related measurement uncertainty for virtually any measurement task. The key element of...... purpose to establish traceability. Accuracy performances of optical digitisation systems are assessed on the basis of deviations existing between acquired cloud points and the CMM measurements. To demonstrate the feasibility of the proposed method, the procedure is applied to an industrial case study....

  3. Modeling for ultrasonic testing accuracy in probabilistic fracture mechanics analysis

    This study proposes models for ultrasonic testing (UT) accuracy at In-service Inspection (ISI) in probabilistic fracture mechanics (PFM) analysis. Regression analysis of the data brought by Ultrasonic Test and Evaluation for Maintenance Standards (UTS) project and modeling for successful candidates of Performance demonstration certification system provided the models for accuracy of flaw detection and sizing. New PFM analysis code, which evaluates failure probabilities at weld lines in piping aged by Stress Corrosion Cracking, has been developed by JAEA. The models were introduced into the code. Failure probabilities under the UT models at a weld line were evaluated by the code. (author)

  4. Empathic accuracy for happiness in the daily lives of older couples: Fluid cognitive performance predicts pattern accuracy among men.

    Hülür, Gizem; Hoppmann, Christiane A; Rauers, Antje; Schade, Hannah; Ram, Nilam; Gerstorf, Denis

    2016-08-01

    Correctly identifying other's emotional states is a central cognitive component of empathy. We examined the role of fluid cognitive performance for empathic accuracy for happiness in the daily lives of 86 older couples (mean relationship length = 45 years; mean age = 75 years) on up to 42 occasions over 7 consecutive days. Men performing better on the Digit Symbol test were more accurate in identifying ups and downs of their partner's happiness. A similar association was not found for women. We discuss the potential role of fluid cognitive performance and other individual, partner, and situation characteristics for empathic accuracy. (PsycINFO Database Record PMID:27362351

  5. Assessing accuracy of an electronic provincial medication repository

    Price Morgan

    2012-05-01

    Full Text Available Abstract Background Jurisdictional drug information systems are being implemented in many regions around the world. British Columbia, Canada has had a provincial medication dispensing record, PharmaNet, system since 1995. Little is known about how accurately PharmaNet reflects actual medication usage. Methods This prospective, multi-centre study compared pharmacist collected Best Possible Medication Histories (BPMH to PharmaNet profiles to assess accuracy of the PharmaNet profiles for patients receiving a BPMH as part of clinical care. A review panel examined the anonymized BPMHs and discrepancies to estimate clinical significance of discrepancies. Results 16% of medication profiles were accurate, with 48% of the discrepant profiles considered potentially clinically significant by the clinical review panel. Cardiac medications tended to be more accurate (e.g. ramipril was accurate >90% of the time, while insulin, warfarin, salbutamol and pain relief medications were often inaccurate (80–85% of the time. 1215 sequential BPMHs were collected and reviewed for this study. Conclusions The PharmaNet medication repository has a low accuracy and should be used in conjunction with other sources for medication histories for clinical or research purposes. This finding is consistent with other, smaller medication repository accuracy studies in other jurisdictions. Our study highlights specific medications that tend to be lower in accuracy.

  6. Accuracy of the NDI Wave Speech Research System

    Berry, Jeffrey J.

    2011-01-01

    Purpose: This work provides a quantitative assessment of the positional tracking accuracy of the NDI Wave Speech Research System. Method: Three experiments were completed: (a) static rigid-body tracking across different locations in the electromagnetic field volume, (b) dynamic rigid-body tracking across different locations within the…

  7. Numerical accuracy of mean-field calculations in coordinate space

    Ryssens, W; Heenen, P -H

    2015-01-01

    Background: Mean-field methods based on an energy density functional (EDF) are powerful tools used to describe many properties of nuclei in the entirety of the nuclear chart. The accuracy required on energies for nuclear physics and astrophysics applications is of the order of 500 keV and much effort is undertaken to build EDFs that meet this requirement. Purpose: The mean-field calculations have to be accurate enough in order to preserve the accuracy of the EDF. We study this numerical accuracy in detail for a specific numerical choice of representation for the mean-field equations that can accommodate any kind of symmetry breaking. Method: The method that we use is a particular implementation of 3-dimensional mesh calculations. Its numerical accuracy is governed by three main factors: the size of the box in which the nucleus is confined, the way numerical derivatives are calculated and the distance between the points on the mesh. Results: We have examined the dependence of the results on these three factors...

  8. Improving axial depth of cut accuracy in micromilling

    Bissacco, Giuliano; Hansen, Hans Nørgaard; De Chiffre, Leonardo

    2004-01-01

    and their rapid warming and cooling, which prevent the achievement of a steady state. Several other factors, independent on the tool-workpiece interaction, influence the machining accuracy. The cutting parameter most heavily affected is the axial depth of cut which is the most critical when using...

  9. Accuracy assessment of SAR interferometry using the ERS-1

    Broquetas Ibars, Antoni

    1995-01-01

    A SAR raw data simulator and a SAR processor are used as a tool for performance assessment of SAR interferometry algorithms like the multi-baseline and multifrequency. Traditional algorithms have also been tested with real ERS-1 data and validated with a high accuracy reference DEM. Peer Reviewed

  10. Method for Improving Indoor Positioning Accuracy Using Extended Kalman Filter

    Seoung-Hyeon Lee

    2016-01-01

    Full Text Available Beacons using bluetooth low-energy (BLE technology have emerged as a new paradigm of indoor positioning service (IPS because of their advantages such as low power consumption, miniaturization, wide signal range, and low cost. However, the beacon performance is poor in terms of the indoor positioning accuracy because of noise, motion, and fading, all of which are characteristics of a bluetooth signal and depend on the installation location. Therefore, it is necessary to improve the accuracy of beacon-based indoor positioning technology by fusing it with existing indoor positioning technology, which uses Wi-Fi, ZigBee, and so forth. This study proposes a beacon-based indoor positioning method using an extended Kalman filter that recursively processes input data including noise. After defining the movement of a smartphone on a flat two-dimensional surface, it was assumed that the beacon signal is nonlinear. Then, the standard deviation and properties of the beacon signal were analyzed. According to the analysis results, an extended Kalman filter was designed and the accuracy of the smartphone’s indoor position was analyzed through simulations and tests. The proposed technique achieved good indoor positioning accuracy, with errors of 0.26 m and 0.28 m from the average x- and y-coordinates, respectively, based solely on the beacon signal.

  11. Diagnostic accuracy of temporomandibular disorder pain tests: a multicenter study

    C.M. Visscher; M. Naeije; A. de Laat; A. Michelotti; M. Nilner; B. Craane; E. Ekberg; M. Farella; F. Lobbezoo

    2009-01-01

    AIMS: To estimate the diagnostic accuracy of the Research Diagnostic Criteria for Temporomandibular Disorders (RDC/TMD) clinical examination and of the dynamic/static tests for the recognition of TMD pain. Since the diagnosis of TMD pain is especially complicated in persistent orofacial pain patient

  12. Assessing accuracy in citizen science-based plant phenology monitoring

    Fuccillo, Kerissa K.; Crimmins, Theresa M.; de Rivera, Catherine E.; Elder, Timothy S.

    2015-07-01

    In the USA, thousands of volunteers are engaged in tracking plant and animal phenology through a variety of citizen science programs for the purpose of amassing spatially and temporally comprehensive datasets useful to scientists and resource managers. The quality of these observations and their suitability for scientific analysis, however, remains largely unevaluated. We aimed to evaluate the accuracy of plant phenology observations collected by citizen scientist volunteers following protocols designed by the USA National Phenology Network (USA-NPN). Phenology observations made by volunteers receiving several hours of formal training were compared to those collected independently by a professional ecologist. Approximately 11,000 observations were recorded by 28 volunteers over the course of one field season. Volunteers consistently identified phenophases correctly (91 % overall) for the 19 species observed. Volunteers demonstrated greatest overall accuracy identifying unfolded leaves, ripe fruits, and open flowers. Transitional accuracy decreased for some species/phenophase combinations (70 % average), and accuracy varied significantly by phenophase and species ( p training can provide reliable observations when following explicit, standardized protocols. Future studies should investigate different observation models (i.e., group/individual, online/in-person training) over subsequent seasons with multiple expert comparisons to further substantiate the ability of these monitoring programs to supply accurate broadscale datasets capable of answering pressing ecological questions about global change.

  13. The inhibitory avoidance discrimination task to investigate accuracy of memory

    Atucha Trevino, E.; Roozendaal, B.

    2015-01-01

    The present study was aimed at developing a new inhibitory avoidance task, based on training and/or testing rats in multiple contexts, to investigate accuracy of memory. In the first experiment, male Sprague-Dawley rats were given footshock in an inhibitory avoidance apparatus and, 48 h later, reten

  14. Separating Speed from Accuracy in Beginning Reading Development

    Juul, Holger; Poulsen, Mads; Elbro, Carsten

    2014-01-01

    Phoneme awareness, letter knowledge, and rapid automatized naming (RAN) are well-known kindergarten predictors of later word recognition skills, but it is not clear whether they predict developments in accuracy or speed, or both. The present longitudinal study of 172 Danish beginning readers found that speed of word recognition mainly developed…

  15. Enhancement of diffusers BSDF accuracy: spectral features effect

    Brug, H. van; Courrèges-Lacoste, G.B.; Otter, G.C.J.; Schaarsberg, J.G.; Delwart, S.; Del Bello, U.

    2006-01-01

    This paper reports the activities performed in the framework of the ESA contract 18432/04/NL/AR: Enhancement of diffusers BSDF Accuracy. This study was conducted to investigate properties of various diffusers. Diffusers are widely used in space instruments as part of the on-board absolute calibratio

  16. Accuracy of a heart failure diagnosis in administrative registers

    Kümler, Thomas; Gislason, Gunnar Hilmar; Kirk, Vibeke;

    2008-01-01

    BACKGROUND: The incidence of heart failure is frequently reported using hospital discharge diagnoses. The specificity of a diagnosis has been shown to be high but the sensitivity of a reported diagnosis is unknown. PURPOSE: To study the accuracy of a heart failure diagnosis reported to the Danish...

  17. Multiple sequence alignment accuracy and evolutionary distance estimation

    Rosenberg Michael S

    2005-11-01

    Full Text Available Abstract Background Sequence alignment is a common tool in bioinformatics and comparative genomics. It is generally assumed that multiple sequence alignment yields better results than pair wise sequence alignment, but this assumption has rarely been tested, and never with the control provided by simulation analysis. This study used sequence simulation to examine the gain in accuracy of adding a third sequence to a pair wise alignment, particularly concentrating on how the phylogenetic position of the additional sequence relative to the first pair changes the accuracy of the initial pair's alignment as well as their estimated evolutionary distance. Results The maximal gain in alignment accuracy was found not when the third sequence is directly intermediate between the initial two sequences, but rather when it perfectly subdivides the branch leading from the root of the tree to one of the original sequences (making it half as close to one sequence as the other. Evolutionary distance estimation in the multiple alignment framework, however, is largely unrelated to alignment accuracy and rather is dependent on the position of the third sequence; the closer the branch leading to the third sequence is to the root of the tree, the larger the estimated distance between the first two sequences. Conclusion The bias in distance estimation appears to be a direct result of the standard greedy progressive algorithm used by many multiple alignment methods. These results have implications for choosing new taxa and genomes to sequence when resources are limited.

  18. Improving Accuracy of Sleep Self-Reports through Correspondence Training

    St. Peter, Claire C.; Montgomery-Downs, Hawley E.; Massullo, Joel P.

    2012-01-01

    Sleep insufficiency is a major public health concern, yet the accuracy of self-reported sleep measures is often poor. Self-report may be useful when direct measurement of nonverbal behavior is impossible, infeasible, or undesirable, as it may be with sleep measurement. We used feedback and positive reinforcement within a small-n multiple-baseline…

  19. Accuracy of physical examination for chronic lumbar radiculopathy

    Iversen, Trond; Solberg, Tore K; Romner, Bertil; Wilsgaard, Tom; Nygaard, Øystein; Waterloo, Knut; Brox, Jens I; Ingebrigtsen, Tor

    2013-01-01

    Background Clinical examination of patients with chronic lumbar radiculopathy aims to clarify whether there is nerve root impingement. The aims of this study were to investigate the association between findings at clinical examination and nerve root impingement, to evaluate the accuracy of clinical index tests in a specialised care setting, and to see whether imaging clarifies the cause of chronic radicular pain. Method...

  20. Improving Accuracy for Image Fusion in Abdominal Ultrasonography

    Caroline Ewertsen

    2012-08-01

    Full Text Available Image fusion involving real-time ultrasound (US is a technique where previously recorded computed tomography (CT or magnetic resonance images (MRI are reformatted in a projection to fit the real-time US images after an initial co-registration. The co-registration aligns the images by means of common planes or points. We evaluated the accuracy of the alignment when varying parameters as patient position, respiratory phase and distance from the co-registration points/planes. We performed a total of 80 co-registrations and obtained the highest accuracy when the respiratory phase for the co-registration procedure was the same as when the CT or MRI was obtained. Furthermore, choosing co-registration points/planes close to the area of interest also improved the accuracy. With all settings optimized a mean error of 3.2 mm was obtained. We conclude that image fusion involving real-time US is an accurate method for abdominal examinations and that the accuracy is influenced by various adjustable factors that should be kept in mind.