WorldWideScience

Sample records for level setting means

  1. Out-of-Core Computations of High-Resolution Level Sets by Means of Code Transformation

    DEFF Research Database (Denmark)

    Christensen, Brian Bunch; Nielsen, Michael Bang; Museth, Ken

    2012-01-01

    We propose a storage efficient, fast and parallelizable out-of-core framework for streaming computations of high resolution level sets. The fundamental techniques are skewing and tiling transformations of streamed level set computations which allow for the combination of interface propagation, re...... computations are now CPU bound and consequently the overall performance is unaffected by disk latency and bandwidth limitations. We demonstrate this with several benchmark tests that show sustained out-of-core throughputs close to that of in-core level set simulations....

  2. Levels of Literary Meaning

    DEFF Research Database (Denmark)

    Klausen, Søren Harnow

    2017-01-01

    I argue that intentionalist theories of meaning and interpretation, like those of Hirsch and Juhl, have been insufficiently attentive to the different levels of authorial intention that are operative in literary works. By countenancing intentions on different levels – ranging from simple semantic...

  3. Computer-aided measurement of liver volumes in CT by means of geodesic active contour segmentation coupled with level-set algorithms

    Energy Technology Data Exchange (ETDEWEB)

    Suzuki, Kenji; Kohlbrenner, Ryan; Epstein, Mark L.; Obajuluwa, Ademola M.; Xu Jianwu; Hori, Masatoshi [Department of Radiology, University of Chicago, 5841 South Maryland Avenue, Chicago, Illinois 60637 (United States)

    2010-05-15

    Purpose: Computerized liver extraction from hepatic CT images is challenging because the liver often abuts other organs of a similar density. The purpose of this study was to develop a computer-aided measurement of liver volumes in hepatic CT. Methods: The authors developed a computerized liver extraction scheme based on geodesic active contour segmentation coupled with level-set contour evolution. First, an anisotropic diffusion filter was applied to portal-venous-phase CT images for noise reduction while preserving the liver structure, followed by a scale-specific gradient magnitude filter to enhance the liver boundaries. Then, a nonlinear grayscale converter enhanced the contrast of the liver parenchyma. By using the liver-parenchyma-enhanced image as a speed function, a fast-marching level-set algorithm generated an initial contour that roughly estimated the liver shape. A geodesic active contour segmentation algorithm coupled with level-set contour evolution refined the initial contour to define the liver boundaries more precisely. The liver volume was then calculated using these refined boundaries. Hepatic CT scans of 15 prospective liver donors were obtained under a liver transplant protocol with a multidetector CT system. The liver volumes extracted by the computerized scheme were compared to those traced manually by a radiologist, used as ''gold standard.''Results: The mean liver volume obtained with our scheme was 1504 cc, whereas the mean gold standard manual volume was 1457 cc, resulting in a mean absolute difference of 105 cc (7.2%). The computer-estimated liver volumetrics agreed excellently with the gold-standard manual volumetrics (intraclass correlation coefficient was 0.95) with no statistically significant difference (F=0.77; p(F{<=}f)=0.32). The average accuracy, sensitivity, specificity, and percent volume error were 98.4%, 91.1%, 99.1%, and 7.2%, respectively. Computerized CT liver volumetry would require substantially less

  4. Computer-aided measurement of liver volumes in CT by means of geodesic active contour segmentation coupled with level-set algorithms

    International Nuclear Information System (INIS)

    Suzuki, Kenji; Kohlbrenner, Ryan; Epstein, Mark L.; Obajuluwa, Ademola M.; Xu Jianwu; Hori, Masatoshi

    2010-01-01

    Purpose: Computerized liver extraction from hepatic CT images is challenging because the liver often abuts other organs of a similar density. The purpose of this study was to develop a computer-aided measurement of liver volumes in hepatic CT. Methods: The authors developed a computerized liver extraction scheme based on geodesic active contour segmentation coupled with level-set contour evolution. First, an anisotropic diffusion filter was applied to portal-venous-phase CT images for noise reduction while preserving the liver structure, followed by a scale-specific gradient magnitude filter to enhance the liver boundaries. Then, a nonlinear grayscale converter enhanced the contrast of the liver parenchyma. By using the liver-parenchyma-enhanced image as a speed function, a fast-marching level-set algorithm generated an initial contour that roughly estimated the liver shape. A geodesic active contour segmentation algorithm coupled with level-set contour evolution refined the initial contour to define the liver boundaries more precisely. The liver volume was then calculated using these refined boundaries. Hepatic CT scans of 15 prospective liver donors were obtained under a liver transplant protocol with a multidetector CT system. The liver volumes extracted by the computerized scheme were compared to those traced manually by a radiologist, used as ''gold standard.''Results: The mean liver volume obtained with our scheme was 1504 cc, whereas the mean gold standard manual volume was 1457 cc, resulting in a mean absolute difference of 105 cc (7.2%). The computer-estimated liver volumetrics agreed excellently with the gold-standard manual volumetrics (intraclass correlation coefficient was 0.95) with no statistically significant difference (F=0.77; p(F≤f)=0.32). The average accuracy, sensitivity, specificity, and percent volume error were 98.4%, 91.1%, 99.1%, and 7.2%, respectively. Computerized CT liver volumetry would require substantially less completion time

  5. A segmentation and classification scheme for single tooth in MicroCT images based on 3D level set and k-means+.

    Science.gov (United States)

    Wang, Liansheng; Li, Shusheng; Chen, Rongzhen; Liu, Sze-Yu; Chen, Jyh-Cheng

    2017-04-01

    Accurate classification of different anatomical structures of teeth from medical images provides crucial information for the stress analysis in dentistry. Usually, the anatomical structures of teeth are manually labeled by experienced clinical doctors, which is time consuming. However, automatic segmentation and classification is a challenging task because the anatomical structures and surroundings of the tooth in medical images are rather complex. Therefore, in this paper, we propose an effective framework which is designed to segment the tooth with a Selective Binary and Gaussian Filtering Regularized Level Set (GFRLS) method improved by fully utilizing 3 dimensional (3D) information, and classify the tooth by employing unsupervised learning i.e., k-means++ method. In order to evaluate the proposed method, the experiments are conducted on the sufficient and extensive datasets of mandibular molars. The experimental results show that our method can achieve higher accuracy and robustness compared to other three clustering methods. Copyright © 2016 Elsevier Ltd. All rights reserved.

  6. Non-Asymptotic Confidence Sets for Circular Means

    Directory of Open Access Journals (Sweden)

    Thomas Hotz

    2016-10-01

    Full Text Available The mean of data on the unit circle is defined as the minimizer of the average squared Euclidean distance to the data. Based on Hoeffding’s mass concentration inequalities, non-asymptotic confidence sets for circular means are constructed which are universal in the sense that they require no distributional assumptions. These are then compared with asymptotic confidence sets in simulations and for a real data set.

  7. On reinitializing level set functions

    Science.gov (United States)

    Min, Chohong

    2010-04-01

    In this paper, we consider reinitializing level functions through equation ϕt+sgn(ϕ0)(‖∇ϕ‖-1)=0[16]. The method of Russo and Smereka [11] is taken in the spatial discretization of the equation. The spatial discretization is, simply speaking, the second order ENO finite difference with subcell resolution near the interface. Our main interest is on the temporal discretization of the equation. We compare the three temporal discretizations: the second order Runge-Kutta method, the forward Euler method, and a Gauss-Seidel iteration of the forward Euler method. The fact that the time in the equation is fictitious makes a hypothesis that all the temporal discretizations result in the same result in their stationary states. The fact that the absolute stability region of the forward Euler method is not wide enough to include all the eigenvalues of the linearized semi-discrete system of the second order ENO spatial discretization makes another hypothesis that the forward Euler temporal discretization should invoke numerical instability. Our results in this paper contradict both the hypotheses. The Runge-Kutta and Gauss-Seidel methods obtain the second order accuracy, and the forward Euler method converges with order between one and two. Examining all their properties, we conclude that the Gauss-Seidel method is the best among the three. Compared to the Runge-Kutta, it is twice faster and requires memory two times less with the same accuracy.

  8. Tides, surges and mean sea-level

    National Research Council Canada - National Science Library

    Pugh, D. T

    1987-01-01

    .... Interest in mean sea-level changes has recently been focused on the possibility of significant increases over the coming century as a result of global warming. Examples of applications from North America, Europe and other parts of the world are included.

  9. Mean-Variance Analysis in a Multiperiod Setting

    OpenAIRE

    Frauendorfer, Karl; Siede, Heiko

    1997-01-01

    Similar to the classical Markowitz approach it is possible to apply a mean-variance criterion to a multiperiod setting to obtain efficient portfolios. To represent the stochastic dynamic characteristics necessary for modelling returns a process of asset returns is discretized with respect to time and space and summarized in a scenario tree. The resulting optimization problem is solved by means of stochastic multistage programming. The optimal solutions show equivalent structural properties as...

  10. Fast Sparse Level Sets on Graphics Hardware

    NARCIS (Netherlands)

    Jalba, Andrei C.; Laan, Wladimir J. van der; Roerdink, Jos B.T.M.

    The level-set method is one of the most popular techniques for capturing and tracking deformable interfaces. Although level sets have demonstrated great potential in visualization and computer graphics applications, such as surface editing and physically based modeling, their use for interactive

  11. Intonational meaning in institutional settings: the role of syntagmatic relations

    Science.gov (United States)

    Wichmann, Anne

    2010-12-01

    This paper addresses the power of intonation to convey interpersonal or attitudinal meaning. Speakers have been shown to accommodate to each other in the course of conversation, and this convergence may be perceived as a sign of empathy. Accommodation often involves paradigmatic choices—choosing the same words, gestures, regional accent or melodic pattern, but this paper suggests that affective meaning can also be conveyed syntagmatically through the relationship between prosodic features in successive utterances. The paper also addresses the use of prosody in situations of conflict, particularly in institutional settings. The requirement of the more powerful participant to exercise control may conflict with the expression of empathy. Situations are described where divergent rather than convergent behaviour is more successful both in keeping control and in maintaining rapport.

  12. Level Sets and Voronoi based Feature Extraction from any Imagery

    DEFF Research Database (Denmark)

    Sharma, O.; Anton, François; Mioc, Darka

    2012-01-01

    Polygon features are of interest in many GEOProcessing applications like shoreline mapping, boundary delineation, change detection, etc. This paper presents a unique new GPU-based methodology to automate feature extraction combining level sets, or mean shift based segmentation together with Voron...

  13. ACRIM III Level 2 Daily Mean Data V001

    Data.gov (United States)

    National Aeronautics and Space Administration — Active Cavity Radiometer Irradiance Monitor (ACRIM) III Level 2 Daily Mean Data product consists of Level 2 total solar irradiance in the form of daily means...

  14. Intonational Meaning in Institutional Settings: The Role of Syntagmatic Relations

    Science.gov (United States)

    Wichmann, Anne

    2010-01-01

    This paper addresses the power of intonation to convey interpersonal or attitudinal meaning. Speakers have been shown to accommodate to each other in the course of conversation, and this convergence may be perceived as a sign of empathy. Accommodation often involves paradigmatic choices--choosing the same words, gestures, regional accent or…

  15. Mean level signal crossing rate for an arbitrary stochastic process

    DEFF Research Database (Denmark)

    Yura, Harold T.; Hanson, Steen Grüner

    2010-01-01

    The issue of the mean signal level crossing rate for various probability density functions with primary relevance for optics is discussed based on a new analytical method. This method relies on a unique transformation that transforms the probability distribution under investigation into a normal...... probability distribution, for which the distribution of mean level crossings is known. In general, the analytical results for the mean level crossing rate are supported and confirmed by numerical simulations. In particular, we illustrate the present method by presenting analytic expressions for the mean level...

  16. Discretisation Schemes for Level Sets of Planar Gaussian Fields

    Science.gov (United States)

    Beliaev, D.; Muirhead, S.

    2018-01-01

    Smooth random Gaussian functions play an important role in mathematical physics, a main example being the random plane wave model conjectured by Berry to give a universal description of high-energy eigenfunctions of the Laplacian on generic compact manifolds. Our work is motivated by questions about the geometry of such random functions, in particular relating to the structure of their nodal and level sets. We study four discretisation schemes that extract information about level sets of planar Gaussian fields. Each scheme recovers information up to a different level of precision, and each requires a maximum mesh-size in order to be valid with high probability. The first two schemes are generalisations and enhancements of similar schemes that have appeared in the literature (Beffara and Gayet in Publ Math IHES, 2017. https://doi.org/10.1007/s10240-017-0093-0; Mischaikow and Wanner in Ann Appl Probab 17:980-1018, 2007); these give complete topological information about the level sets on either a local or global scale. As an application, we improve the results in Beffara and Gayet (2017) on Russo-Seymour-Welsh estimates for the nodal set of positively-correlated planar Gaussian fields. The third and fourth schemes are, to the best of our knowledge, completely new. The third scheme is specific to the nodal set of the random plane wave, and provides global topological information about the nodal set up to `visible ambiguities'. The fourth scheme gives a way to approximate the mean number of excursion domains of planar Gaussian fields.

  17. Setting the stage for master's level success

    Science.gov (United States)

    Roberts, Donna

    Comprehensive reading, writing, research, and study skills play a critical role in a graduate student's success and ability to contribute to a field of study effectively. The literature indicated a need to support graduate student success in the areas of mentoring, navigation, as well as research and writing. The purpose of this two-phased mixed methods explanatory study was to examine factors that characterize student success at the Master's level in the fields of education, sociology and social work. The study was grounded in a transformational learning framework which focused on three levels of learning: technical knowledge, practical or communicative knowledge, and emancipatory knowledge. The study included two data collection points. Phase one consisted of a Master's Level Success questionnaire that was sent via Qualtrics to graduate level students at three colleges and universities in the Central Valley of California: a California State University campus, a University of California campus, and a private college campus. The results of the chi-square indicated that seven questionnaire items were significant with p values less than .05. Phase two in the data collection included semi-structured interview questions that resulted in three themes emerged using Dedoose software: (1) the need for more language and writing support at the Master's level, (2) the need for mentoring, especially for second-language learners, and (3) utilizing the strong influence of faculty in student success. It is recommended that institutions continually assess and strengthen their programs to meet the full range of learners and to support students to degree completion.

  18. Level Set Approach to Anisotropic Wet Etching of Silicon

    Directory of Open Access Journals (Sweden)

    Branislav Radjenović

    2010-05-01

    Full Text Available In this paper a methodology for the three dimensional (3D modeling and simulation of the profile evolution during anisotropic wet etching of silicon based on the level set method is presented. Etching rate anisotropy in silicon is modeled taking into account full silicon symmetry properties, by means of the interpolation technique using experimentally obtained values for the etching rates along thirteen principal and high index directions in KOH solutions. The resulting level set equations are solved using an open source implementation of the sparse field method (ITK library, developed in medical image processing community, extended for the case of non-convex Hamiltonians. Simulation results for some interesting initial 3D shapes, as well as some more practical examples illustrating anisotropic etching simulation in the presence of masks (simple square aperture mask, convex corner undercutting and convex corner compensation, formation of suspended structures are shown also. The obtained results show that level set method can be used as an effective tool for wet etching process modeling, and that is a viable alternative to the Cellular Automata method which now prevails in the simulations of the wet etching process.

  19. Level-set techniques for facies identification in reservoir modeling

    Science.gov (United States)

    Iglesias, Marco A.; McLaughlin, Dennis

    2011-03-01

    In this paper we investigate the application of level-set techniques for facies identification in reservoir models. The identification of facies is a geometrical inverse ill-posed problem that we formulate in terms of shape optimization. The goal is to find a region (a geologic facies) that minimizes the misfit between predicted and measured data from an oil-water reservoir. In order to address the shape optimization problem, we present a novel application of the level-set iterative framework developed by Burger in (2002 Interfaces Free Bound. 5 301-29 2004 Inverse Problems 20 259-82) for inverse obstacle problems. The optimization is constrained by (the reservoir model) a nonlinear large-scale system of PDEs that describes the reservoir dynamics. We reformulate this reservoir model in a weak (integral) form whose shape derivative can be formally computed from standard results of shape calculus. At each iteration of the scheme, the current estimate of the shape derivative is utilized to define a velocity in the level-set equation. The proper selection of this velocity ensures that the new shape decreases the cost functional. We present results of facies identification where the velocity is computed with the gradient-based (GB) approach of Burger (2002) and the Levenberg-Marquardt (LM) technique of Burger (2004). While an adjoint formulation allows the straightforward application of the GB approach, the LM technique requires the computation of the large-scale Karush-Kuhn-Tucker system that arises at each iteration of the scheme. We efficiently solve this system by means of the representer method. We present some synthetic experiments to show and compare the capabilities and limitations of the proposed implementations of level-set techniques for the identification of geologic facies.

  20. Level-set techniques for facies identification in reservoir modeling

    International Nuclear Information System (INIS)

    Iglesias, Marco A; McLaughlin, Dennis

    2011-01-01

    In this paper we investigate the application of level-set techniques for facies identification in reservoir models. The identification of facies is a geometrical inverse ill-posed problem that we formulate in terms of shape optimization. The goal is to find a region (a geologic facies) that minimizes the misfit between predicted and measured data from an oil–water reservoir. In order to address the shape optimization problem, we present a novel application of the level-set iterative framework developed by Burger in (2002 Interfaces Free Bound. 5 301–29; 2004 Inverse Problems 20 259–82) for inverse obstacle problems. The optimization is constrained by (the reservoir model) a nonlinear large-scale system of PDEs that describes the reservoir dynamics. We reformulate this reservoir model in a weak (integral) form whose shape derivative can be formally computed from standard results of shape calculus. At each iteration of the scheme, the current estimate of the shape derivative is utilized to define a velocity in the level-set equation. The proper selection of this velocity ensures that the new shape decreases the cost functional. We present results of facies identification where the velocity is computed with the gradient-based (GB) approach of Burger (2002) and the Levenberg–Marquardt (LM) technique of Burger (2004). While an adjoint formulation allows the straightforward application of the GB approach, the LM technique requires the computation of the large-scale Karush–Kuhn–Tucker system that arises at each iteration of the scheme. We efficiently solve this system by means of the representer method. We present some synthetic experiments to show and compare the capabilities and limitations of the proposed implementations of level-set techniques for the identification of geologic facies

  1. Integrative study of the mean sea level and its components

    CERN Document Server

    Champollion, Nicolas; Paul, Frank; Benveniste, Jérôme

    2017-01-01

    This volume presents the most recent results of global mean sea level variations over the satellite altimetry era (starting in the early 1990s) and associated contributions, such as glaciers and ice sheets mass loss, ocean thermal expansion, and land water storage changes. Sea level is one of the best indicators of global climate changes as it integrates the response of several components of the climate system to external forcing factors (including anthropogenic forcing) and internal climate variability. Providing long, accurate records of the sea level at global and regional scales and of the various components causing sea level changes is of crucial importance to improve our understanding of climate processes at work and to validate the climate models used for future projections. The Climate Change Initiative project of the European Space Agency has provided a first attempt to produce consistent and continuous space-based records for several climate parameters observable from space, among them sea level. Th...

  2. Annual mean sea level and its sensitivity to wind climate

    Science.gov (United States)

    Gerkema, Theo; Duran Matute, Matias

    2017-04-01

    Changes in relative mean sea level affect coastal areas in various ways, such as the risk of flooding, the evolution of barrier island systems, or the development of salt marshes. Long-term trends in these changes are partly masked by variability on shorter time scales. Some of this variability, for instance due to wind waves and tides (with the exception of long-period tides), is easily averaged out. In contrast, inter-annual variability is found to be irregular and large, of the order of several decimeters, as is evident from tide gauge records. This is why the climatic trend, typically of a few millimeters per year, can only be reliably identified by examining a record that is long enough to outweigh the inter-annual and decadal variabilities. In this presentation we examine the relation between the annual wind conditions from meteorological records and annual mean sea level along the Dutch coast. To do this, we need reliable and consistent long-term wind records. Some wind records from weather stations in the Netherlands date back to the 19th century, but they are unsuitable for trend analysis because of changes in location, height, surroundings, instrument type or protocol. For this reason, we will use only more recent, homogeneous wind records, from the past two decades. The question then is whether such a relatively short record is sufficient to find a convincing relation with annual mean sea level. It is the purpose of this work to demonstrate that the answer is positive and to suggest methods to find and exploit such a relation. We find that at the Dutch coast, southwesterly winds are dominant in the wind climate, but the west-east direction stands out as having the highest correlation with annual mean sea level. For different stations in the Dutch Wadden Sea and along the coast, we find a qualitatively similar pattern, although the precise values of the correlations vary. The inter-annual variability of mean sea level can already be largely explained by

  3. A parametric level-set method for partially discrete tomography

    NARCIS (Netherlands)

    A. Kadu (Ajinkya); T. van Leeuwen (Tristan); K.J. Batenburg (Joost)

    2017-01-01

    textabstractThis paper introduces a parametric level-set method for tomographic reconstruction of partially discrete images. Such images consist of a continuously varying background and an anomaly with a constant (known) grey-value. We express the geometry of the anomaly using a level-set function,

  4. Identifying Heterogeneities in Subsurface Environment using the Level Set Method

    Energy Technology Data Exchange (ETDEWEB)

    Lei, Hongzhuan [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Lu, Zhiming [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Vesselinov, Velimir Valentinov [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2016-08-25

    These are slides from a presentation on identifying heterogeneities in subsurface environment using the level set method. The slides start with the motivation, then explain Level Set Method (LSM), the algorithms, some examples are given, and finally future work is explained.

  5. Segmenting the Parotid Gland using Registration and Level Set Methods

    DEFF Research Database (Denmark)

    Hollensen, Christian; Hansen, Mads Fogtmann; Højgaard, Liselotte

    . The method was evaluated on a test set consisting of 8 corresponding data sets. The attained total volume Dice coefficient and mean Haussdorff distance were 0.61 ± 0.20 and 15.6 ± 7.4 mm respectively. The method has improvement potential which could be exploited in order for clinical introduction....

  6. A new level set model for multimaterial flows

    Energy Technology Data Exchange (ETDEWEB)

    Starinshak, David P. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Karni, Smadar [Univ. of Michigan, Ann Arbor, MI (United States). Dept. of Mathematics; Roe, Philip L. [Univ. of Michigan, Ann Arbor, MI (United States). Dept. of AerospaceEngineering

    2014-01-08

    We present a new level set model for representing multimaterial flows in multiple space dimensions. Instead of associating a level set function with a specific fluid material, the function is associated with a pair of materials and the interface that separates them. A voting algorithm collects sign information from all level sets and determines material designations. M(M ₋1)/2 level set functions might be needed to represent a general M-material configuration; problems of practical interest use far fewer functions, since not all pairs of materials share an interface. The new model is less prone to producing indeterminate material states, i.e. regions claimed by more than one material (overlaps) or no material at all (vacuums). It outperforms existing material-based level set models without the need for reinitialization schemes, thereby avoiding additional computational costs and preventing excessive numerical diffusion.

  7. Precise mean sea level measurements using the Global Positioning System

    Science.gov (United States)

    Kelecy, Thomas M.; Born, George H.; Parke, Michael E.; Rocken, Christian

    1994-01-01

    This paper describes the results of a sea level measurement test conducted off La Jolla, California, in November of 1991. The purpose of this test was to determine accurate sea level measurements using a Global Positioning System (GPS) equipped buoy. These measurements were intended to be used as the sea level component for calibration of the ERS 1 satellite altimeter. Measurements were collected on November 25 and 28 when the ERS 1 satellite overflew the calibration area. Two different types of buoys were used. A waverider design was used on November 25 and a spar design on November 28. This provided the opportunity to examine how dynamic effects of the measurement platform might affect the sea level accuracy. The two buoys were deployed at locations approximately 1.2 km apart and about 15 km west of a reference GPS receiver located on the rooftop of the Institute of Geophysics and Planetary Physics at the Scripps Institute of Oceanography. GPS solutions were computed for 45 minutes on each day and used to produce two sea level time series. An estimate of the mean sea level at both locations was computed by subtracting tide gage data collected at the Scripps Pier from the GPS-determined sea level measurements and then filtering out the high-frequency components due to waves and buoy dynamics. In both cases the GPS estimate differed from Rapp's mean altimetric surface by 0.06 m. Thus, the gradient in the GPS measurements matched the gradient in Rapp's surface. These results suggest that accurate sea level can be determined using GPS on widely differing platforms as long as care is taken to determine the height of the GPS antenna phase center above water level. Application areas include measurement of absolute sea level, of temporal variations in sea level, and of sea level gradients (dominantly the geoid). Specific applications would include ocean altimeter calibration, monitoring of sea level in remote regions, and regional experiments requiring spatial and

  8. Fourier transform and mean quadratic variation of Bernoulli convolution on homogeneous Cantor set

    Energy Technology Data Exchange (ETDEWEB)

    Yu Zuguo E-mail: yuzg@hotmail.comz.yu

    2004-07-01

    For the Bernoulli convolution on homogeneous Cantor set, under some condition, it is proved that the mean quadratic variation and the average of Fourier transform of this measure are bounded above and below.

  9. Novel gene sets improve set-level classification of prokaryotic gene expression data.

    Science.gov (United States)

    Holec, Matěj; Kuželka, Ondřej; Železný, Filip

    2015-10-28

    Set-level classification of gene expression data has received significant attention recently. In this setting, high-dimensional vectors of features corresponding to genes are converted into lower-dimensional vectors of features corresponding to biologically interpretable gene sets. The dimensionality reduction brings the promise of a decreased risk of overfitting, potentially resulting in improved accuracy of the learned classifiers. However, recent empirical research has not confirmed this expectation. Here we hypothesize that the reported unfavorable classification results in the set-level framework were due to the adoption of unsuitable gene sets defined typically on the basis of the Gene ontology and the KEGG database of metabolic networks. We explore an alternative approach to defining gene sets, based on regulatory interactions, which we expect to collect genes with more correlated expression. We hypothesize that such more correlated gene sets will enable to learn more accurate classifiers. We define two families of gene sets using information on regulatory interactions, and evaluate them on phenotype-classification tasks using public prokaryotic gene expression data sets. From each of the two gene-set families, we first select the best-performing subtype. The two selected subtypes are then evaluated on independent (testing) data sets against state-of-the-art gene sets and against the conventional gene-level approach. The novel gene sets are indeed more correlated than the conventional ones, and lead to significantly more accurate classifiers. The novel gene sets are indeed more correlated than the conventional ones, and lead to significantly more accurate classifiers. Novel gene sets defined on the basis of regulatory interactions improve set-level classification of gene expression data. The experimental scripts and other material needed to reproduce the experiments are available at http://ida.felk.cvut.cz/novelgenesets.tar.gz.

  10. Volume Sculpting Using the Level-Set Method

    DEFF Research Database (Denmark)

    Bærentzen, Jakob Andreas; Christensen, Niels Jørgen

    2002-01-01

    In this paper, we propose the use of the Level--Set Method as the underlying technology of a volume sculpting system. The main motivation is that this leads to a very generic technique for deformation of volumetric solids. In addition, our method preserves a distance field volume representation....... A scaling window is used to adapt the Level--Set Method to local deformations and to allow the user to control the intensity of the tool. Level--Set based tools have been implemented in an interactive sculpting system, and we show sculptures created using the system....

  11. Mean-field level analysis of epidemics in directed networks

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Jiazeng [School of Mathematical Sciences, Peking University, Beijing 100871 (China); Liu, Zengrong [Mathematics Department, Shanghai University, Shanghai 200444 (China)], E-mail: wangjiazen@yahoo.com.cn, E-mail: zrongliu@online.sh.cn

    2009-09-04

    The susceptible-infected-removed spreading model in a directed graph is studied. The mean-field level rate equations are built with the degree-degree connectivity correlation element and the (in, out)-degree distribution. And the outbreak threshold is obtained analytically-it is determined by the combination of connectivity probability and the degree distribution. Furthermore, the methods of calculating the degree-degree correlations in directed networks are presented. The numerical results of the discrete epidemic processes in networks verify our analyses.

  12. Mean-field level analysis of epidemics in directed networks

    International Nuclear Information System (INIS)

    Wang, Jiazeng; Liu, Zengrong

    2009-01-01

    The susceptible-infected-removed spreading model in a directed graph is studied. The mean-field level rate equations are built with the degree-degree connectivity correlation element and the (in, out)-degree distribution. And the outbreak threshold is obtained analytically-it is determined by the combination of connectivity probability and the degree distribution. Furthermore, the methods of calculating the degree-degree correlations in directed networks are presented. The numerical results of the discrete epidemic processes in networks verify our analyses.

  13. Empirical Assessment of the Mean Block Volume of Rock Masses Intersected by Four Joint Sets

    Science.gov (United States)

    Morelli, Gian Luca

    2016-05-01

    The estimation of a representative value for the rock block volume ( V b) is of huge interest in rock engineering in regards to rock mass characterization purposes. However, while mathematical relationships to precisely estimate this parameter from the spacing of joints can be found in literature for rock masses intersected by three dominant joint sets, corresponding relationships do not actually exist when more than three sets occur. In these cases, a consistent assessment of V b can only be achieved by directly measuring the dimensions of several representative natural rock blocks in the field or by means of more sophisticated 3D numerical modeling approaches. However, Palmström's empirical relationship based on the volumetric joint count J v and on a block shape factor β is commonly used in the practice, although strictly valid only for rock masses intersected by three joint sets. Starting from these considerations, the present paper is primarily intended to investigate the reliability of a set of empirical relationships linking the block volume with the indexes most commonly used to characterize the degree of jointing in a rock mass (i.e. the J v and the mean value of the joint set spacings) specifically applicable to rock masses intersected by four sets of persistent discontinuities. Based on the analysis of artificial 3D block assemblies generated using the software AutoCAD, the most accurate best-fit regression has been found between the mean block volume (V_{{{{b}}_{{m}} }}) of tested rock mass samples and the geometric mean value of the spacings of the joint sets delimiting blocks; thus, indicating this mean value as a promising parameter for the preliminary characterization of the block size. Tests on field outcrops have demonstrated that the proposed empirical methodology has the potential of predicting the mean block volume of multiple-set jointed rock masses with an acceptable accuracy for common uses in most practical rock engineering applications.

  14. A level set method for multiple sclerosis lesion segmentation.

    Science.gov (United States)

    Zhao, Yue; Guo, Shuxu; Luo, Min; Shi, Xue; Bilello, Michel; Zhang, Shaoxiang; Li, Chunming

    2018-06-01

    In this paper, we present a level set method for multiple sclerosis (MS) lesion segmentation from FLAIR images in the presence of intensity inhomogeneities. We use a three-phase level set formulation of segmentation and bias field estimation to segment MS lesions and normal tissue region (including GM and WM) and CSF and the background from FLAIR images. To save computational load, we derive a two-phase formulation from the original multi-phase level set formulation to segment the MS lesions and normal tissue regions. The derived method inherits the desirable ability to precisely locate object boundaries of the original level set method, which simultaneously performs segmentation and estimation of the bias field to deal with intensity inhomogeneity. Experimental results demonstrate the advantages of our method over other state-of-the-art methods in terms of segmentation accuracy. Copyright © 2017 Elsevier Inc. All rights reserved.

  15. Some numerical studies of interface advection properties of level set ...

    Indian Academy of Sciences (India)

    explicit computational elements moving through an Eulerian grid. ... location. The interface is implicitly defined (captured) as the location of the discontinuity in the ... This level set function is advected with the background flow field and thus ...

  16. Exploring the level sets of quantum control landscapes

    International Nuclear Information System (INIS)

    Rothman, Adam; Ho, Tak-San; Rabitz, Herschel

    2006-01-01

    A quantum control landscape is defined by the value of a physical observable as a functional of the time-dependent control field E(t) for a given quantum-mechanical system. Level sets through this landscape are prescribed by a particular value of the target observable at the final dynamical time T, regardless of the intervening dynamics. We present a technique for exploring a landscape level set, where a scalar variable s is introduced to characterize trajectories along these level sets. The control fields E(s,t) accomplishing this exploration (i.e., that produce the same value of the target observable for a given system) are determined by solving a differential equation over s in conjunction with the time-dependent Schroedinger equation. There is full freedom to traverse a level set, and a particular trajectory is realized by making an a priori choice for a continuous function f(s,t) that appears in the differential equation for the control field. The continuous function f(s,t) can assume an arbitrary form, and thus a level set generally contains a family of controls, where each control takes the quantum system to the same final target value, but produces a distinct control mechanism. In addition, although the observable value remains invariant over the level set, other dynamical properties (e.g., the degree of robustness to control noise) are not specifically preserved and can vary greatly. Examples are presented to illustrate the continuous nature of level-set controls and their associated induced dynamical features, including continuously morphing mechanisms for population control in model quantum systems

  17. On multiple level-set regularization methods for inverse problems

    International Nuclear Information System (INIS)

    DeCezaro, A; Leitão, A; Tai, X-C

    2009-01-01

    We analyze a multiple level-set method for solving inverse problems with piecewise constant solutions. This method corresponds to an iterated Tikhonov method for a particular Tikhonov functional G α based on TV–H 1 penalization. We define generalized minimizers for our Tikhonov functional and establish an existence result. Moreover, we prove convergence and stability results of the proposed Tikhonov method. A multiple level-set algorithm is derived from the first-order optimality conditions for the Tikhonov functional G α , similarly as the iterated Tikhonov method. The proposed multiple level-set method is tested on an inverse potential problem. Numerical experiments show that the method is able to recover multiple objects as well as multiple contrast levels

  18. Level-Set Topology Optimization with Aeroelastic Constraints

    Science.gov (United States)

    Dunning, Peter D.; Stanford, Bret K.; Kim, H. Alicia

    2015-01-01

    Level-set topology optimization is used to design a wing considering skin buckling under static aeroelastic trim loading, as well as dynamic aeroelastic stability (flutter). The level-set function is defined over the entire 3D volume of a transport aircraft wing box. Therefore, the approach is not limited by any predefined structure and can explore novel configurations. The Sequential Linear Programming (SLP) level-set method is used to solve the constrained optimization problems. The proposed method is demonstrated using three problems with mass, linear buckling and flutter objective and/or constraints. A constraint aggregation method is used to handle multiple buckling constraints in the wing skins. A continuous flutter constraint formulation is used to handle difficulties arising from discontinuities in the design space caused by a switching of the critical flutter mode.

  19. Level Set Structure of an Integrable Cellular Automaton

    Directory of Open Access Journals (Sweden)

    Taichiro Takagi

    2010-03-01

    Full Text Available Based on a group theoretical setting a sort of discrete dynamical system is constructed and applied to a combinatorial dynamical system defined on the set of certain Bethe ansatz related objects known as the rigged configurations. This system is then used to study a one-dimensional periodic cellular automaton related to discrete Toda lattice. It is shown for the first time that the level set of this cellular automaton is decomposed into connected components and every such component is a torus.

  20. Choice architecture as a means to change eating behaviour in self-service settings

    DEFF Research Database (Denmark)

    Skov, Laurits Rohden; Lourenco, Sofia; Laub Hansen, Gitte

    2013-01-01

    Summary: The primary objective of this review was to investigate the current evidence-base for the use of choice architecture as a means to change eating behaviour in self-service eating settings, hence potentially reduce calorie intake. 12 databases were searched systematically for experimental ...

  1. Integrating cultural community psychology: activity settings and the shared meanings of intersubjectivity.

    Science.gov (United States)

    O'Donnell, Clifford R; Tharp, Roland G

    2012-03-01

    Cultural and community psychology share a common emphasis on context, yet their leading journals rarely cite each other's articles. Greater integration of the concepts of culture and community within and across their disciplines would enrich and facilitate the viability of cultural community psychology. The contextual theory of activity settings is proposed as one means to integrate the concepts of culture and community in cultural community psychology. Through shared activities, participants develop common experiences that affect their psychological being, including their cognitions, emotions, and behavioral development. The psychological result of these experiences is intersubjectivity. Culture is defined as the shared meanings that people develop through their common historic, linguistic, social, economic, and political experiences. The shared meanings of culture arise through the intersubjectivity developed in activity settings. Cultural community psychology presents formidable epistemological challenges, but overcoming these challenges could contribute to the transformation and advancement of community psychology.

  2. A deep level set method for image segmentation

    OpenAIRE

    Tang, Min; Valipour, Sepehr; Zhang, Zichen Vincent; Cobzas, Dana; MartinJagersand

    2017-01-01

    This paper proposes a novel image segmentation approachthat integrates fully convolutional networks (FCNs) with a level setmodel. Compared with a FCN, the integrated method can incorporatesmoothing and prior information to achieve an accurate segmentation.Furthermore, different than using the level set model as a post-processingtool, we integrate it into the training phase to fine-tune the FCN. Thisallows the use of unlabeled data during training in a semi-supervisedsetting. Using two types o...

  3. A Level Set Discontinuous Galerkin Method for Free Surface Flows

    DEFF Research Database (Denmark)

    Grooss, Jesper; Hesthaven, Jan

    2006-01-01

    We present a discontinuous Galerkin method on a fully unstructured grid for the modeling of unsteady incompressible fluid flows with free surfaces. The surface is modeled by embedding and represented by a levelset. We discuss the discretization of the flow equations and the level set equation...

  4. Level set methods for inverse scattering—some recent developments

    International Nuclear Information System (INIS)

    Dorn, Oliver; Lesselier, Dominique

    2009-01-01

    We give an update on recent techniques which use a level set representation of shapes for solving inverse scattering problems, completing in that matter the exposition made in (Dorn and Lesselier 2006 Inverse Problems 22 R67) and (Dorn and Lesselier 2007 Deformable Models (New York: Springer) pp 61–90), and bringing it closer to the current state of the art

  5. Structural level set inversion for microwave breast screening

    International Nuclear Information System (INIS)

    Irishina, Natalia; Álvarez, Diego; Dorn, Oliver; Moscoso, Miguel

    2010-01-01

    We present a new inversion strategy for the early detection of breast cancer from microwave data which is based on a new multiphase level set technique. This novel structural inversion method uses a modification of the color level set technique adapted to the specific situation of structural breast imaging taking into account the high complexity of the breast tissue. We only use data of a few microwave frequencies for detecting the tumors hidden in this complex structure. Three level set functions are employed for describing four different types of breast tissue, where each of these four regions is allowed to have a complicated topology and to have an interior structure which needs to be estimated from the data simultaneously with the region interfaces. The algorithm consists of several stages of increasing complexity. In each stage more details about the anatomical structure of the breast interior is incorporated into the inversion model. The synthetic breast models which are used for creating simulated data are based on real MRI images of the breast and are therefore quite realistic. Our results demonstrate the potential and feasibility of the proposed level set technique for detecting, locating and characterizing a small tumor in its early stage of development embedded in such a realistic breast model. Both the data acquisition simulation and the inversion are carried out in 2D

  6. Level-Set Methodology on Adaptive Octree Grids

    Science.gov (United States)

    Gibou, Frederic; Guittet, Arthur; Mirzadeh, Mohammad; Theillard, Maxime

    2017-11-01

    Numerical simulations of interfacial problems in fluids require a methodology capable of tracking surfaces that can undergo changes in topology and capable to imposing jump boundary conditions in a sharp manner. In this talk, we will discuss recent advances in the level-set framework, in particular one that is based on adaptive grids.

  7. A Memory and Computation Efficient Sparse Level-Set Method

    NARCIS (Netherlands)

    Laan, Wladimir J. van der; Jalba, Andrei C.; Roerdink, Jos B.T.M.

    Since its introduction, the level set method has become the favorite technique for capturing and tracking moving interfaces, and found applications in a wide variety of scientific fields. In this paper we present efficient data structures and algorithms for tracking dynamic interfaces through the

  8. Hybrid approach for detection of dental caries based on the methods FCM and level sets

    Science.gov (United States)

    Chaabene, Marwa; Ben Ali, Ramzi; Ejbali, Ridha; Zaied, Mourad

    2017-03-01

    This paper presents a new technique for detection of dental caries that is a bacterial disease that destroys the tooth structure. In our approach, we have achieved a new segmentation method that combines the advantages of fuzzy C mean algorithm and level set method. The results obtained by the FCM algorithm will be used by Level sets algorithm to reduce the influence of the noise effect on the working of each of these algorithms, to facilitate level sets manipulation and to lead to more robust segmentation. The sensitivity and specificity confirm the effectiveness of proposed method for caries detection.

  9. Reassessment of 20th century global mean sea level rise

    Science.gov (United States)

    Dangendorf, Sönke; Marcos, Marta; Wöppelmann, Guy; Conrad, Clinton P.; Frederikse, Thomas; Riva, Riccardo

    2017-01-01

    The rate at which global mean sea level (GMSL) rose during the 20th century is uncertain, with little consensus between various reconstructions that indicate rates of rise ranging from 1.3 to 2 mm⋅y−1. Here we present a 20th-century GMSL reconstruction computed using an area-weighting technique for averaging tide gauge records that both incorporates up-to-date observations of vertical land motion (VLM) and corrections for local geoid changes resulting from ice melting and terrestrial freshwater storage and allows for the identification of possible differences compared with earlier attempts. Our reconstructed GMSL trend of 1.1 ± 0.3 mm⋅y−1 (1σ) before 1990 falls below previous estimates, whereas our estimate of 3.1 ± 1.4 mm⋅y−1 from 1993 to 2012 is consistent with independent estimates from satellite altimetry, leading to overall acceleration larger than previously suggested. This feature is geographically dominated by the Indian Ocean–Southern Pacific region, marking a transition from lower-than-average rates before 1990 toward unprecedented high rates in recent decades. We demonstrate that VLM corrections, area weighting, and our use of a common reference datum for tide gauges may explain the lower rates compared with earlier GMSL estimates in approximately equal proportion. The trends and multidecadal variability of our GMSL curve also compare well to the sum of individual contributions obtained from historical outputs of the Coupled Model Intercomparison Project Phase 5. This, in turn, increases our confidence in process-based projections presented in the Fifth Assessment Report of the Intergovernmental Panel on Climate Change. PMID:28533403

  10. An update: choice architecture as a means to change eating behaviour in self-service settings

    DEFF Research Database (Denmark)

    Skov, Laurits Rohden; Perez-Cueto, Armando

    2014-01-01

    Objective: The primary objective of this review was to update the current evidence-base for the use of choice architecture as a means to change eating behaviour in self-service eating settings, hence potentially reducing energy intake. Methodology: 12 databases were searched systematically for ex...... in the topic of choice architecture and nudging has increased the scientific output since the last review. There is a clear limitation in the lack of a clear definitions and theoretical foundation....

  11. TCTE Level 3 Total Solar Irradiance Daily Means V002

    Data.gov (United States)

    National Aeronautics and Space Administration — The Total Solar Irradiance (TSI) Calibration Transfer Experiment (TCTE) data set TCTE3TSID contains daily averaged total solar irradiance (a.k.a solar constant) data...

  12. Gradient augmented level set method for phase change simulations

    Science.gov (United States)

    Anumolu, Lakshman; Trujillo, Mario F.

    2018-01-01

    A numerical method for the simulation of two-phase flow with phase change based on the Gradient-Augmented-Level-set (GALS) strategy is presented. Sharp capturing of the vaporization process is enabled by: i) identification of the vapor-liquid interface, Γ (t), at the subgrid level, ii) discontinuous treatment of thermal physical properties (except for μ), and iii) enforcement of mass, momentum, and energy jump conditions, where the gradients of the dependent variables are obtained at Γ (t) and are consistent with their analytical expression, i.e. no local averaging is applied. Treatment of the jump in velocity and pressure at Γ (t) is achieved using the Ghost Fluid Method. The solution of the energy equation employs the sub-grid knowledge of Γ (t) to discretize the temperature Laplacian using second-order one-sided differences, i.e. the numerical stencil completely resides within each respective phase. To carefully evaluate the benefits or disadvantages of the GALS approach, the standard level set method is implemented and compared against the GALS predictions. The results show the expected trend that interface identification and transport are predicted noticeably better with GALS over the standard level set. This benefit carries over to the prediction of the Laplacian and temperature gradients in the neighborhood of the interface, which are directly linked to the calculation of the vaporization rate. However, when combining the calculation of interface transport and reinitialization with two-phase momentum and energy, the benefits of GALS are to some extent neutralized, and the causes for this behavior are identified and analyzed. Overall the additional computational costs associated with GALS are almost the same as those using the standard level set technique.

  13. Level sets and extrema of random processes and fields

    CERN Document Server

    Azais, Jean-Marc

    2009-01-01

    A timely and comprehensive treatment of random field theory with applications across diverse areas of study Level Sets and Extrema of Random Processes and Fields discusses how to understand the properties of the level sets of paths as well as how to compute the probability distribution of its extremal values, which are two general classes of problems that arise in the study of random processes and fields and in related applications. This book provides a unified and accessible approach to these two topics and their relationship to classical theory and Gaussian processes and fields, and the most modern research findings are also discussed. The authors begin with an introduction to the basic concepts of stochastic processes, including a modern review of Gaussian fields and their classical inequalities. Subsequent chapters are devoted to Rice formulas, regularity properties, and recent results on the tails of the distribution of the maximum. Finally, applications of random fields to various areas of mathematics a...

  14. Skull defect reconstruction based on a new hybrid level set.

    Science.gov (United States)

    Zhang, Ziqun; Zhang, Ran; Song, Zhijian

    2014-01-01

    Skull defect reconstruction is an important aspect of surgical repair. Historically, a skull defect prosthesis was created by the mirroring technique, surface fitting, or formed templates. These methods are not based on the anatomy of the individual patient's skull, and therefore, the prosthesis cannot precisely correct the defect. This study presented a new hybrid level set model, taking into account both the global optimization region information and the local accuracy edge information, while avoiding re-initialization during the evolution of the level set function. Based on the new method, a skull defect was reconstructed, and the skull prosthesis was produced by rapid prototyping technology. This resulted in a skull defect prosthesis that well matched the skull defect with excellent individual adaptation.

  15. A new level set model for cell image segmentation

    Science.gov (United States)

    Ma, Jing-Feng; Hou, Kai; Bao, Shang-Lian; Chen, Chun

    2011-02-01

    In this paper we first determine three phases of cell images: background, cytoplasm and nucleolus according to the general physical characteristics of cell images, and then develop a variational model, based on these characteristics, to segment nucleolus and cytoplasm from their relatively complicated backgrounds. In the meantime, the preprocessing obtained information of cell images using the OTSU algorithm is used to initialize the level set function in the model, which can speed up the segmentation and present satisfactory results in cell image processing.

  16. Meaning

    Science.gov (United States)

    Harteveld, Casper

    The second world to be considered concerns Meaning. In contrast to Reality and Play, this world relates to the people, disciplines, and domains that are focused on creating a certain value. For example, if this value is about providing students knowledge about physics, it involves teachers, the learning sciences, and the domains education and physics. This level goes into the aspects and criteria that designers need to take into account from this perspective. The first aspect seems obvious when we talk of “games with a serious purpose.” They have a purpose and this needs to be elaborated on, for example in terms of what “learning objectives” it attempts to achieve. The subsequent aspect is not about what is being pursued but how. To attain a value, designers have to think about a strategy that they employ. In my case this concerned looking at the learning paradigms that have come into existence in the past century and see what they have to tell us about learning. This way, their principles can be translated into a game environment. This translation involves making the strategy concrete. Or, in other words, operationalizing the plan. This is the third aspect. In this level, I will further specifically explain how I derived requirements from each of the learning paradigms, like reflection and exploration, and how they can possibly be related to games. The fourth and final aspect is the context in which the game is going to be used. It matters who uses the game and when, where, and how the game is going to be used. When designers have looked at these aspects, they have developed a “value proposal” and the worth of it may be judged by criteria, like motivation, relevance, and transfer. But before I get to this, I first go into how we human beings are meaning creators and what role assumptions, knowledge, and ambiguity have in this. I will illustrate this with some silly jokes about doctors and Mickey Mouse, and with an illusion.

  17. Privacy-Preserving k-Means Clustering under Multiowner Setting in Distributed Cloud Environments

    Directory of Open Access Journals (Sweden)

    Hong Rong

    2017-01-01

    Full Text Available With the advent of big data era, clients who lack computational and storage resources tend to outsource data mining tasks to cloud service providers in order to improve efficiency and reduce costs. It is also increasingly common for clients to perform collaborative mining to maximize profits. However, due to the rise of privacy leakage issues, the data contributed by clients should be encrypted using their own keys. This paper focuses on privacy-preserving k-means clustering over the joint datasets encrypted under multiple keys. Unfortunately, existing outsourcing k-means protocols are impractical because not only are they restricted to a single key setting, but also they are inefficient and nonscalable for distributed cloud computing. To address these issues, we propose a set of privacy-preserving building blocks and outsourced k-means clustering protocol under Spark framework. Theoretical analysis shows that our scheme protects the confidentiality of the joint database and mining results, as well as access patterns under the standard semihonest model with relatively small computational overhead. Experimental evaluations on real datasets also demonstrate its efficiency improvements compared with existing approaches.

  18. Reevaluation of steam generator level trip set point

    Energy Technology Data Exchange (ETDEWEB)

    Shim, Yoon Sub; Soh, Dong Sub; Kim, Sung Oh; Jung, Se Won; Sung, Kang Sik; Lee, Joon [Korea Atomic Energy Research Institute, Taejon (Korea, Republic of)

    1994-06-01

    The reactor trip by the low level of steam generator water accounts for a substantial portion of reactor scrams in a nuclear plant and the feasibility of modification of the steam generator water level trip system of YGN 1/2 was evaluated in this study. The study revealed removal of the reactor trip function from the SG water level trip system is not possible because of plant safety but relaxation of the trip set point by 9 % is feasible. The set point relaxation requires drilling of new holes for level measurement to operating steam generators. Characteristics of negative neutron flux rate trip and reactor trip were also reviewed as an additional work. Since the purpose of the trip system modification for reduction of a reactor scram frequency is not to satisfy legal requirements but to improve plant performance and the modification yields positive and negative aspects, the decision of actual modification needs to be made based on the results of this study and also the policy of a plant owner. 37 figs, 6 tabs, 14 refs. (Author).

  19. Level set method for image segmentation based on moment competition

    Science.gov (United States)

    Min, Hai; Wang, Xiao-Feng; Huang, De-Shuang; Jin, Jing; Wang, Hong-Zhi; Li, Hai

    2015-05-01

    We propose a level set method for image segmentation which introduces the moment competition and weakly supervised information into the energy functional construction. Different from the region-based level set methods which use force competition, the moment competition is adopted to drive the contour evolution. Here, a so-called three-point labeling scheme is proposed to manually label three independent points (weakly supervised information) on the image. Then the intensity differences between the three points and the unlabeled pixels are used to construct the force arms for each image pixel. The corresponding force is generated from the global statistical information of a region-based method and weighted by the force arm. As a result, the moment can be constructed and incorporated into the energy functional to drive the evolving contour to approach the object boundary. In our method, the force arm can take full advantage of the three-point labeling scheme to constrain the moment competition. Additionally, the global statistical information and weakly supervised information are successfully integrated, which makes the proposed method more robust than traditional methods for initial contour placement and parameter setting. Experimental results with performance analysis also show the superiority of the proposed method on segmenting different types of complicated images, such as noisy images, three-phase images, images with intensity inhomogeneity, and texture images.

  20. Level set segmentation of medical images based on local region statistics and maximum a posteriori probability.

    Science.gov (United States)

    Cui, Wenchao; Wang, Yi; Lei, Tao; Fan, Yangyu; Feng, Yan

    2013-01-01

    This paper presents a variational level set method for simultaneous segmentation and bias field estimation of medical images with intensity inhomogeneity. In our model, the statistics of image intensities belonging to each different tissue in local regions are characterized by Gaussian distributions with different means and variances. According to maximum a posteriori probability (MAP) and Bayes' rule, we first derive a local objective function for image intensities in a neighborhood around each pixel. Then this local objective function is integrated with respect to the neighborhood center over the entire image domain to give a global criterion. In level set framework, this global criterion defines an energy in terms of the level set functions that represent a partition of the image domain and a bias field that accounts for the intensity inhomogeneity of the image. Therefore, image segmentation and bias field estimation are simultaneously achieved via a level set evolution process. Experimental results for synthetic and real images show desirable performances of our method.

  1. Celebrating 80 years of the Permanent Service for Mean Sea Level (PSMSL

    Directory of Open Access Journals (Sweden)

    L. Rickards

    2015-03-01

    Full Text Available The PSMSL was established as a “Permanent Service” of the International Council for Science in 1958, but in practice was a continuation of the Mean Sea Level Committee which had been set up at the Lisbon International Union of Geodesy and Geophysics (IUGG conference in 1933. Now in its 80th year, the PSMSL continues to be the internationally recognised databank for long-term sea level change information from tide gauge records. The PSMSL dataset consists of over 2100 mean sea level records from across the globe, the longest of which date back to the start of the 19th century. Where possible, all data in a series are provided to a common benchmark-controlled datum, thus providing a record suitable for use in time series analysis. The PSMSL dataset is freely available for all to use, and is accessible through the PSMSL website (www.psmsl.org.

  2. Evaluation of the Global Mean Sea Level Budget between 1993 and 2014

    DEFF Research Database (Denmark)

    Chambers, Don P.; Cazenave, Anny; Champollion, Nicolas

    2017-01-01

    Evaluating global mean sea level (GMSL) in terms of its components—mass and steric—is useful for both quantifying the accuracy of the measurements and understanding the processes that contribute to GMSL rise. In this paper, we review the GMSL budget over two periods—1993 to 2014 and 2005 to 2014......—using multiple data sets of both total GMSL and the components (mass and steric). In addition to comparing linear trends, we also compare the level of agreement of the time series. For the longer period (1993–2014), we find closure in terms of the long-term trend but not for year-to-year variations...

  3. A new level set model for cell image segmentation

    International Nuclear Information System (INIS)

    Ma Jing-Feng; Chen Chun; Hou Kai; Bao Shang-Lian

    2011-01-01

    In this paper we first determine three phases of cell images: background, cytoplasm and nucleolus according to the general physical characteristics of cell images, and then develop a variational model, based on these characteristics, to segment nucleolus and cytoplasm from their relatively complicated backgrounds. In the meantime, the preprocessing obtained information of cell images using the OTSU algorithm is used to initialize the level set function in the model, which can speed up the segmentation and present satisfactory results in cell image processing. (cross-disciplinary physics and related areas of science and technology)

  4. Identifying meaning and perceived level of satisfaction within the context of work.

    Science.gov (United States)

    Brown, Angie; Kitchell, Molly; O'Neill, Tiffany; Lockliear, Jennifer; Vosler, Alyson; Kubek, Dayna; Dale, Lucinda

    2001-01-01

    OBJECTIVE: The primary objectives of this study were to identify sources of meaning for individuals within the context of a work environment, and to compare varied sources of meaning for individuals with high and low work satisfaction levels. METHOD: Participants were chosen based on satisfaction levels in employment, full-time employment status within an organization for at least one year, and diversity in the work setting. Data were gathered through a series of interviews and observations of the participants' workplaces. A comparative analysis of transcribed interviews was conducted by the researchers and with an expert occupational therapy faculty panel. From these analyses, the researchers developed work narratives for a mechanical engineer, a high school teacher, an employee of mechanical services, and a career service counselor. RESULTS: Emerging themes from the work narratives indicated that the various meanings employees found in work had an effect on their perceived levels of job satisfaction. Participants conveyed that organization identification, financial benefits, independent decision-making, reciprocal respect, opportunities for creativity, and maintaining significant relationships outside of work enhanced meaning and satisfaction. CONCLUSIONS: The worker role is a significant source of an individual's identity, meaning, and satisfaction in life. Professionals in various fields can work with employers to develop meaningful work environments for increased job satisfaction, greater motivation for work, increased productivity, and decreased employee turnover.

  5. Mean Streets: An analysis on street level pollution in NYC

    Science.gov (United States)

    Parker, G.

    2017-12-01

    The overarching objective of this study is to quantify the spatial and temporal variability in particulatematter concentration (PM 2.5) along crowded streets in New York City. Due to their fine size and lowdensity PM 2.5 stays longer in the atmosphere and could bypass human nose and throat and penetratedeep in to the lungs and even enter the circulatory system. PM 2.5 is a by-product of automobilecombustion and is a primary cause of respiratory malfunction in NYC. The study would monitor streetlevel concentration of PM2.5 across three different routes that witness significant pedestrian traffic;observations will be conducted along these three routes at different time periods. The study will use theAirBeam community air quality monitor. The monitor tracks PM 2.5 concentration along with GPS, airtemperature and relative humidity. The surface level concentration monitored by AirBeam will becompared with atmospheric concentration of PM 2.5 that are monitored at the NOAA CREST facility onCCNY campus. The lower atmospheric values will be correlated with street level values to assess thevalidity of using of lower atmospheric values to predict street level concentrations. The street levelconcentration will be compared to the air quality forecasted by the New York Department ofEnvironment Conservation to estimate its accuracy and applicability.

  6. Operational Meanings of Orders of Observables Defined through Quantum Set Theories with Different Conditionals

    Directory of Open Access Journals (Sweden)

    Masanao Ozawa

    2017-01-01

    Full Text Available In quantum logic there is well-known arbitrariness in choosing a binary operation for conditional. Currently, we have at least three candidates, called the Sasaki conditional, the contrapositive Sasaki conditional, and the relevance conditional. A fundamental problem is to show how the form of the conditional follows from an analysis of operational concepts in quantum theory. Here, we attempt such an analysis through quantum set theory (QST. In this paper, we develop quantum set theory based on quantum logics with those three conditionals, each of which defines different quantum logical truth value assignment. We show that those three models satisfy the transfer principle of the same form to determine the quantum logical truth values of theorems of the ZFC set theory. We also show that the reals in the model and the truth values of their equality are the same for those models. Interestingly, however, the order relation between quantum reals significantly depends on the underlying conditionals. We characterize the operational meanings of those order relations in terms of joint probability obtained by the successive projective measurements of arbitrary two observables. Those characterizations clearly show their individual features and will play a fundamental role in future applications to quantum physics.

  7. The mean platelet volume levels in children with PFAPA syndrome.

    Science.gov (United States)

    Tekin, Mehmet; Toplu, Yuksel; Kahramaner, Zelal; Erdemir, Aydin; Gulyuz, Abdulgani; Konca, Capan; Uckardes, Fatih

    2014-05-01

    To assess whether mean platelet volume (MPV) can be used as a marker in the differential diagnosis of periodic fever, aphthous stomatitis, pharyngitis, adenitis (PFAPA) syndrome. The leucocyte counts, thrombocyte counts, and MPV values of 57 children with PFAPA syndrome were recorded during an attack and an attack free period. These values were compared with a healthy control group of 55 individuals. Demographic features of the PFAPA patients group including age, gender and age of first attack, age at diagnosis, frequency of attacks, serum reactive protein (CRP) and erythrocyte sedimentation rate (ESR) were also recorded. The MPV values of the children with PFAPA both during an attack and attack free period were found significantly lower than the MPV values of healthy control group (pchildren with PFAPA during an attack were significantly lower than in attack free periods (pchildren with PFAPA. The MPV values during an attack and attack free period of patients with PFAPA is lower than in controls. The MPV values may be used as a marker in the differential diagnosis of PFAPA syndrome but more studies are needed and they should be prospective in order to validate this data. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

  8. Thermogram breast cancer prediction approach based on Neutrosophic sets and fuzzy c-means algorithm.

    Science.gov (United States)

    Gaber, Tarek; Ismail, Gehad; Anter, Ahmed; Soliman, Mona; Ali, Mona; Semary, Noura; Hassanien, Aboul Ella; Snasel, Vaclav

    2015-08-01

    The early detection of breast cancer makes many women survive. In this paper, a CAD system classifying breast cancer thermograms to normal and abnormal is proposed. This approach consists of two main phases: automatic segmentation and classification. For the former phase, an improved segmentation approach based on both Neutrosophic sets (NS) and optimized Fast Fuzzy c-mean (F-FCM) algorithm was proposed. Also, post-segmentation process was suggested to segment breast parenchyma (i.e. ROI) from thermogram images. For the classification, different kernel functions of the Support Vector Machine (SVM) were used to classify breast parenchyma into normal or abnormal cases. Using benchmark database, the proposed CAD system was evaluated based on precision, recall, and accuracy as well as a comparison with related work. The experimental results showed that our system would be a very promising step toward automatic diagnosis of breast cancer using thermograms as the accuracy reached 100%.

  9. Mean of Microaccelerations Estimate in the Small Spacecraft Internal Environment with the Use of Fuzzy Sets

    Science.gov (United States)

    Sedelnikov, A. V.

    2018-05-01

    Assessment of parameters of rotary motion of the small spacecraft around its center of mass and of microaccelerations using measurements of current from silicon photocells is carried out. At the same time there is a problem of interpretation of ambiguous telemetric data. Current from two opposite sides of the small spacecraft is significant. The mean of removal of such uncertainty is considered. It is based on an fuzzy set. As membership function it is offered to use a normality condition of the direction cosines. The example of uncertainty removal for a prototype of the Aist small spacecraft is given. The offered approach can significantly increase the accuracy of microaccelerations estimate when using measurements of current from silicon photocells.

  10. Hearing Tests on Mobile Devices: Evaluation of the Reference Sound Level by Means of Biological Calibration.

    Science.gov (United States)

    Masalski, Marcin; Kipiński, Lech; Grysiński, Tomasz; Kręcicki, Tomasz

    2016-05-30

    Hearing tests carried out in home setting by means of mobile devices require previous calibration of the reference sound level. Mobile devices with bundled headphones create a possibility of applying the predefined level for a particular model as an alternative to calibrating each device separately. The objective of this study was to determine the reference sound level for sets composed of a mobile device and bundled headphones. Reference sound levels for Android-based mobile devices were determined using an open access mobile phone app by means of biological calibration, that is, in relation to the normal-hearing threshold. The examinations were conducted in 2 groups: an uncontrolled and a controlled one. In the uncontrolled group, the fully automated self-measurements were carried out in home conditions by 18- to 35-year-old subjects, without prior hearing problems, recruited online. Calibration was conducted as a preliminary step in preparation for further examination. In the controlled group, audiologist-assisted examinations were performed in a sound booth, on normal-hearing subjects verified through pure-tone audiometry, recruited offline from among the workers and patients of the clinic. In both the groups, the reference sound levels were determined on a subject's mobile device using the Bekesy audiometry. The reference sound levels were compared between the groups. Intramodel and intermodel analyses were carried out as well. In the uncontrolled group, 8988 calibrations were conducted on 8620 different devices representing 2040 models. In the controlled group, 158 calibrations (test and retest) were conducted on 79 devices representing 50 models. Result analysis was performed for 10 most frequently used models in both the groups. The difference in reference sound levels between uncontrolled and controlled groups was 1.50 dB (SD 4.42). The mean SD of the reference sound level determined for devices within the same model was 4.03 dB (95% CI 3

  11. Surface-to-surface registration using level sets

    DEFF Research Database (Denmark)

    Hansen, Mads Fogtmann; Erbou, Søren G.; Vester-Christensen, Martin

    2007-01-01

    This paper presents a general approach for surface-to-surface registration (S2SR) with the Euclidean metric using signed distance maps. In addition, the method is symmetric such that the registration of a shape A to a shape B is identical to the registration of the shape B to the shape A. The S2SR...... problem can be approximated by the image registration (IR) problem of the signed distance maps (SDMs) of the surfaces confined to some narrow band. By shrinking the narrow bands around the zero level sets the solution to the IR problem converges towards the S2SR problem. It is our hypothesis...... that this approach is more robust and less prone to fall into local minima than ordinary surface-to-surface registration. The IR problem is solved using the inverse compositional algorithm. In this paper, a set of 40 pelvic bones of Duroc pigs are registered to each other w.r.t. the Euclidean transformation...

  12. Shrinkage covariance matrix approach based on robust trimmed mean in gene sets detection

    Science.gov (United States)

    Karjanto, Suryaefiza; Ramli, Norazan Mohamed; Ghani, Nor Azura Md; Aripin, Rasimah; Yusop, Noorezatty Mohd

    2015-02-01

    Microarray involves of placing an orderly arrangement of thousands of gene sequences in a grid on a suitable surface. The technology has made a novelty discovery since its development and obtained an increasing attention among researchers. The widespread of microarray technology is largely due to its ability to perform simultaneous analysis of thousands of genes in a massively parallel manner in one experiment. Hence, it provides valuable knowledge on gene interaction and function. The microarray data set typically consists of tens of thousands of genes (variables) from just dozens of samples due to various constraints. Therefore, the sample covariance matrix in Hotelling's T2 statistic is not positive definite and become singular, thus it cannot be inverted. In this research, the Hotelling's T2 statistic is combined with a shrinkage approach as an alternative estimation to estimate the covariance matrix to detect significant gene sets. The use of shrinkage covariance matrix overcomes the singularity problem by converting an unbiased to an improved biased estimator of covariance matrix. Robust trimmed mean is integrated into the shrinkage matrix to reduce the influence of outliers and consequently increases its efficiency. The performance of the proposed method is measured using several simulation designs. The results are expected to outperform existing techniques in many tested conditions.

  13. A Variational Level Set Model Combined with FCMS for Image Clustering Segmentation

    Directory of Open Access Journals (Sweden)

    Liming Tang

    2014-01-01

    Full Text Available The fuzzy C means clustering algorithm with spatial constraint (FCMS is effective for image segmentation. However, it lacks essential smoothing constraints to the cluster boundaries and enough robustness to the noise. Samson et al. proposed a variational level set model for image clustering segmentation, which can get the smooth cluster boundaries and closed cluster regions due to the use of level set scheme. However it is very sensitive to the noise since it is actually a hard C means clustering model. In this paper, based on Samson’s work, we propose a new variational level set model combined with FCMS for image clustering segmentation. Compared with FCMS clustering, the proposed model can get smooth cluster boundaries and closed cluster regions due to the use of level set scheme. In addition, a block-based energy is incorporated into the energy functional, which enables the proposed model to be more robust to the noise than FCMS clustering and Samson’s model. Some experiments on the synthetic and real images are performed to assess the performance of the proposed model. Compared with some classical image segmentation models, the proposed model has a better performance for the images contaminated by different noise levels.

  14. Fluoroscopy in paediatric fractures - Setting a local diagnostic reference level

    International Nuclear Information System (INIS)

    Pillai, A.; McAuley, A.; McMurray, K.; Jain, M.

    2006-01-01

    Background: The ionizing radiations (Medical Exposure) Regulation 2000 has made it mandatory to establish diagnostic reference levels (DRLs) for all typical radiological examinations. Objectives: We attempt to provide dose data for some common fluoroscopic procedures used in orthopaedic trauma that may be used as the basis for setting DRLs for paediatric patients. Materials and methods: The dose area product (DAP) in 865 paediatric trauma examinations was analysed. Median DAP values and screening times for each procedure type along with quartile values for each range are presented. Results: In the upper limb, elbow examinations had maximum exposure with a median DAP value of 1.21 cGy cm 2 . Median DAP values for forearm and wrist examinations were 0.708 and 0.538 cGy cm 2 , respectively. In lower limb, tibia and fibula examinations had a median DAP value of 3.23 cGy cm 2 followed by ankle examinations with a median DAP of 3.10 cGy cm 2 . The rounded third quartile DAP value for each distribution can be used as a provisional DRL for the specific procedure type. (authors)

  15. Viewers Extract Mean and Individual Identity from Sets of Famous Faces

    Science.gov (United States)

    Neumann, Markus F.; Schweinberger, Stefan R.; Burton, A. Mike

    2013-01-01

    When viewers are shown sets of similar objects (for example circles), they may extract summary information (e.g., average size) while retaining almost no information about the individual items. A similar observation can be made when using sets of unfamiliar faces: Viewers tend to merge identity or expression information from the set exemplars into…

  16. Topology optimization of hyperelastic structures using a level set method

    Science.gov (United States)

    Chen, Feifei; Wang, Yiqiang; Wang, Michael Yu; Zhang, Y. F.

    2017-12-01

    Soft rubberlike materials, due to their inherent compliance, are finding widespread implementation in a variety of applications ranging from assistive wearable technologies to soft material robots. Structural design of such soft and rubbery materials necessitates the consideration of large nonlinear deformations and hyperelastic material models to accurately predict their mechanical behaviour. In this paper, we present an effective level set-based topology optimization method for the design of hyperelastic structures that undergo large deformations. The method incorporates both geometric and material nonlinearities where the strain and stress measures are defined within the total Lagrange framework and the hyperelasticity is characterized by the widely-adopted Mooney-Rivlin material model. A shape sensitivity analysis is carried out, in the strict sense of the material derivative, where the high-order terms involving the displacement gradient are retained to ensure the descent direction. As the design velocity enters into the shape derivative in terms of its gradient and divergence terms, we develop a discrete velocity selection strategy. The whole optimization implementation undergoes a two-step process, where the linear optimization is first performed and its optimized solution serves as the initial design for the subsequent nonlinear optimization. It turns out that this operation could efficiently alleviate the numerical instability and facilitate the optimization process. To demonstrate the validity and effectiveness of the proposed method, three compliance minimization problems are studied and their optimized solutions present significant mechanical benefits of incorporating the nonlinearities, in terms of remarkable enhancement in not only the structural stiffness but also the critical buckling load.

  17. Adaptable Value-Set Analysis for Low-Level Code

    OpenAIRE

    Brauer, Jörg; Hansen, René Rydhof; Kowalewski, Stefan; Larsen, Kim G.; Olesen, Mads Chr.

    2012-01-01

    This paper presents a framework for binary code analysis that uses only SAT-based algorithms. Within the framework, incremental SAT solving is used to perform a form of weakly relational value-set analysis in a novel way, connecting the expressiveness of the value sets to computational complexity. Another key feature of our framework is that it translates the semantics of binary code into an intermediate representation. This allows for a straightforward translation of the program semantics in...

  18. Level set segmentation of bovine corpora lutea in ex situ ovarian ultrasound images

    Directory of Open Access Journals (Sweden)

    Adams Gregg P

    2008-08-01

    Full Text Available Abstract Background The objective of this study was to investigate the viability of level set image segmentation methods for the detection of corpora lutea (corpus luteum, CL boundaries in ultrasonographic ovarian images. It was hypothesized that bovine CL boundaries could be located within 1–2 mm by a level set image segmentation methodology. Methods Level set methods embed a 2D contour in a 3D surface and evolve that surface over time according to an image-dependent speed function. A speed function suitable for segmentation of CL's in ovarian ultrasound images was developed. An initial contour was manually placed and contour evolution was allowed to proceed until the rate of change of the area was sufficiently small. The method was tested on ovarian ultrasonographic images (n = 8 obtained ex situ. A expert in ovarian ultrasound interpretation delineated CL boundaries manually to serve as a "ground truth". Accuracy of the level set segmentation algorithm was determined by comparing semi-automatically determined contours with ground truth contours using the mean absolute difference (MAD, root mean squared difference (RMSD, Hausdorff distance (HD, sensitivity, and specificity metrics. Results and discussion The mean MAD was 0.87 mm (sigma = 0.36 mm, RMSD was 1.1 mm (sigma = 0.47 mm, and HD was 3.4 mm (sigma = 2.0 mm indicating that, on average, boundaries were accurate within 1–2 mm, however, deviations in excess of 3 mm from the ground truth were observed indicating under- or over-expansion of the contour. Mean sensitivity and specificity were 0.814 (sigma = 0.171 and 0.990 (sigma = 0.00786, respectively, indicating that CLs were consistently undersegmented but rarely did the contour interior include pixels that were judged by the human expert not to be part of the CL. It was observed that in localities where gradient magnitudes within the CL were strong due to high contrast speckle, contour expansion stopped too early. Conclusion The

  19. Goal oriented Mathematics Survey at Preparatory Level- Revised set ...

    African Journals Online (AJOL)

    This cross sectional study design on mathematical syllabi at preparatory levels of the high schools was to investigate the efficiency of the subject at preparatory level education serving as a basis for several streams, like Natural science, Technology, Computer Science, Health Science and Agriculture found at tertiary levels.

  20. Reconstruction of incomplete cell paths through a 3D-2D level set segmentation

    Science.gov (United States)

    Hariri, Maia; Wan, Justin W. L.

    2012-02-01

    Segmentation of fluorescent cell images has been a popular technique for tracking live cells. One challenge of segmenting cells from fluorescence microscopy is that cells in fluorescent images frequently disappear. When the images are stacked together to form a 3D image volume, the disappearance of the cells leads to broken cell paths. In this paper, we present a segmentation method that can reconstruct incomplete cell paths. The key idea of this model is to perform 2D segmentation in a 3D framework. The 2D segmentation captures the cells that appear in the image slices while the 3D segmentation connects the broken cell paths. The formulation is similar to the Chan-Vese level set segmentation which detects edges by comparing the intensity value at each voxel with the mean intensity values inside and outside of the level set surface. Our model, however, performs the comparison on each 2D slice with the means calculated by the 2D projected contour. The resulting effect is to segment the cells on each image slice. Unlike segmentation on each image frame individually, these 2D contours together form the 3D level set function. By enforcing minimum mean curvature on the level set surface, our segmentation model is able to extend the cell contours right before (and after) the cell disappears (and reappears) into the gaps, eventually connecting the broken paths. We will present segmentation results of C2C12 cells in fluorescent images to illustrate the effectiveness of our model qualitatively and quantitatively by different numerical examples.

  1. Statistical modelling of monthly mean sea level at coastal tide gauge stations along the Indian subcontinent

    Digital Repository Service at National Institute of Oceanography (India)

    Srinivas, K.; Das, V.K.; DineshKumar, P.K.

    This study investigates the suitability of statistical models for their predictive potential for the monthly mean sea level at different stations along the west and east coasts of the Indian subcontinent. Statistical modelling of the monthly mean...

  2. Acute stroke: automatic perfusion lesion outlining using level sets.

    Science.gov (United States)

    Mouridsen, Kim; Nagenthiraja, Kartheeban; Jónsdóttir, Kristjana Ýr; Ribe, Lars R; Neumann, Anders B; Hjort, Niels; Østergaard, Leif

    2013-11-01

    To develop a user-independent algorithm for the delineation of hypoperfused tissue on perfusion-weighted images and evaluate its performance relative to a standard threshold method in simulated data, as well as in acute stroke patients. The study was approved by the local ethics committee, and patients gave written informed consent prior to their inclusion in the study. The algorithm identifies hypoperfused tissue in mean transit time maps by simultaneously minimizing the mean square error between individual and mean perfusion values inside and outside a smooth boundary. In 14 acute stroke patients, volumetric agreement between automated outlines and manual outlines determined in consensus among four neuroradiologists was assessed with Bland-Altman analysis, while spatial agreement was quantified by using lesion overlap relative to mean lesion volume (Dice coefficient). Performance improvement relative to a standard threshold approach was tested with the Wilcoxon signed rank test. The mean difference in lesion volume between automated outlines and manual outlines was -9.0 mL ± 44.5 (standard deviation). The lowest mean volume difference for the threshold approach was -25.8 mL ± 88.2. A significantly higher Dice coefficient was observed with the algorithm (0.71; interquartile range [IQR], 0.42-0.75) compared with the threshold approach (0.50; IQR, 0.27- 0.57; P , .001). The corresponding agreement among experts was 0.79 (IQR, 0.69-0.83). The perfusion lesions outlined by the automated algorithm agreed well with those defined manually in consensus by four experts and were superior to those obtained by using the standard threshold approach. This user-independent algorithm may improve the assessment of perfusion images as part of acute stroke treatment. http://radiology.rsna.org/lookup/suppl/doi:10.1148/radiol.13121622/-/DC1. RSNA, 2013

  3. Multi-Attribute Decision-Making Based on Bonferroni Mean Operators under Cubic Intuitionistic Fuzzy Set Environment

    Directory of Open Access Journals (Sweden)

    Gagandeep Kaur

    2018-01-01

    Full Text Available Cubic intuitionistic fuzzy (CIF set is the hybrid set which can contain much more information to express an interval-valued intuitionistic fuzzy set and an intuitionistic fuzzy set simultaneously for handling the uncertainties in the data. Unfortunately, there has been no research on the aggregation operators on CIF sets so far. Since an aggregation operator is an important mathematical tool in decision-making problems, the present paper proposes some new Bonferroni mean and weighted Bonferroni mean averaging operators between the cubic intuitionistic fuzzy numbers for aggregating the different preferences of the decision-maker. Then, we develop a decision-making method based on the proposed operators under the cubic intuitionistic fuzzy environment and illustrated with a numerical example. Finally, a comparison analysis between the proposed and the existing approaches have been performed to illustrate the applicability and feasibility of the developed decision-making method.

  4. Automatic segmentation of Leishmania parasite in microscopic images using a modified CV level set method

    Science.gov (United States)

    Farahi, Maria; Rabbani, Hossein; Talebi, Ardeshir; Sarrafzadeh, Omid; Ensafi, Shahab

    2015-12-01

    Visceral Leishmaniasis is a parasitic disease that affects liver, spleen and bone marrow. According to World Health Organization report, definitive diagnosis is possible just by direct observation of the Leishman body in the microscopic image taken from bone marrow samples. We utilize morphological and CV level set method to segment Leishman bodies in digital color microscopic images captured from bone marrow samples. Linear contrast stretching method is used for image enhancement and morphological method is applied to determine the parasite regions and wipe up unwanted objects. Modified global and local CV level set methods are proposed for segmentation and a shape based stopping factor is used to hasten the algorithm. Manual segmentation is considered as ground truth to evaluate the proposed method. This method is tested on 28 samples and achieved 10.90% mean of segmentation error for global model and 9.76% for local model.

  5. Clustering for Binary Data Sets by Using Genetic Algorithm-Incremental K-means

    Science.gov (United States)

    Saharan, S.; Baragona, R.; Nor, M. E.; Salleh, R. M.; Asrah, N. M.

    2018-04-01

    This research was initially driven by the lack of clustering algorithms that specifically focus in binary data. To overcome this gap in knowledge, a promising technique for analysing this type of data became the main subject in this research, namely Genetic Algorithms (GA). For the purpose of this research, GA was combined with the Incremental K-means (IKM) algorithm to cluster the binary data streams. In GAIKM, the objective function was based on a few sufficient statistics that may be easily and quickly calculated on binary numbers. The implementation of IKM will give an advantage in terms of fast convergence. The results show that GAIKM is an efficient and effective new clustering algorithm compared to the clustering algorithms and to the IKM itself. In conclusion, the GAIKM outperformed other clustering algorithms such as GCUK, IKM, Scalable K-means (SKM) and K-means clustering and paves the way for future research involving missing data and outliers.

  6. Efficient privacy preserving K-means clustering in a three-party setting

    NARCIS (Netherlands)

    Beye, Michael; Erkin, Zekeriya; Erkin, Zekeriya; Lagendijk, Reginald L.

    2011-01-01

    User clustering is a common operation in online social networks, for example to recommend new friends. In previous work [5], Erkin et al. proposed a privacy-preserving K-means clustering algorithm for the semi-honest model, using homomorphic encryption and multi-party computation. This paper makes

  7. Prediction of financial crises by means of rough sets and decision trees

    Directory of Open Access Journals (Sweden)

    Zuleyka Díaz-Martínez

    2011-03-01

    Full Text Available This paper tries to further investigate the factors behind a financial crisis. By using a large sample of countries in the period 1981 to 1999, it intends to apply two methods coming from the Artificial Intelligence (Rough Sets theory and C4.5 algorithm and analyze the role of a set of macroeconomic and financial variables in explaining banking crises. These variables are both quantitative and qualitative. These methods do not require variables or data used to satisfy any assumptions. Statistical methods traditionally employed call for the explicative variables to satisfy statistical assumptions which is quite difficult to happen. This fact complicates the analysis. We obtained good results based on the classification accuracies (80% of correctly classified countries from an independent sample, which proves the suitability of both methods.

  8. Trusting Politicians and Institutions in a Multi-Level Setting

    DEFF Research Database (Denmark)

    Hansen, Sune Welling; Kjær, Ulrik

    Trust in government and in politicians is a very crucial prerequisite for democratic processes. This goes not only for the national level of government but also for the regional and local. We make use of a large scale survey among citizens in Denmark to evaluate trust in politicians at different...... formation processes can negatively influence trust in the mayor and the councilors. Reaching out for the local power by being disloyal to one’s own party or by breaking deals already made can sometimes secure the mayoralty but it comes with a prize: lower trust among the electorate....

  9. Why a Train Set Helps Participants Co-Construct Meaning in Business Model Innovation

    DEFF Research Database (Denmark)

    Beuthel, Maria Rosa; Buur, Jacob

    In this position paper we show how participants in an innovation workshop employ tangible material – a toy train set – to co-construct understandings of a new business model. In multidisciplinary teams the process of developing new terms and concepts together is crucial for work to progress. Every...... to understand how they construct a concept. We observe that the final result of the workshop is indeed innovative and is co-constructed by all group members. We discuss why the toy train works: It keeps both hands and mind busy, it allows silent participation, and it expands the vocabulary of the discussion....

  10. The European gen-set market: growth and consolidation mean joy and pain

    International Nuclear Information System (INIS)

    French, Ian

    2000-01-01

    The changes in the European gen-set market are discussed. In recent years the market has undergone a period of increasing consolidation: prices fell and some companies folded. However, the market is not dead and continued growth is expected over the next five years although the compound rate is forecast to be only 1.5%. The article is presented under the sub-headings of (i) current market situation; (ii) product lifecycle; (iii) shipments by technology; (iv) market deregulation; (v) technology overview (spark ignition, compression ignition and gas turbines) (vi) European market: national overview and (vii) key market challenges (competition, emissions and over capacity)

  11. High-level waste tank farm set point document

    International Nuclear Information System (INIS)

    Anthony, J.A. III.

    1995-01-01

    Setpoints for nuclear safety-related instrumentation are required for actions determined by the design authorization basis. Minimum requirements need to be established for assuring that setpoints are established and held within specified limits. This document establishes the controlling methodology for changing setpoints of all classifications. The instrumentation under consideration involve the transfer, storage, and volume reduction of radioactive liquid waste in the F- and H-Area High-Level Radioactive Waste Tank Farms. The setpoint document will encompass the PROCESS AREA listed in the Safety Analysis Report (SAR) (DPSTSA-200-10 Sup 18) which includes the diversion box HDB-8 facility. In addition to the PROCESS AREAS listed in the SAR, Building 299-H and the Effluent Transfer Facility (ETF) are also included in the scope

  12. High-level waste tank farm set point document

    Energy Technology Data Exchange (ETDEWEB)

    Anthony, J.A. III

    1995-01-15

    Setpoints for nuclear safety-related instrumentation are required for actions determined by the design authorization basis. Minimum requirements need to be established for assuring that setpoints are established and held within specified limits. This document establishes the controlling methodology for changing setpoints of all classifications. The instrumentation under consideration involve the transfer, storage, and volume reduction of radioactive liquid waste in the F- and H-Area High-Level Radioactive Waste Tank Farms. The setpoint document will encompass the PROCESS AREA listed in the Safety Analysis Report (SAR) (DPSTSA-200-10 Sup 18) which includes the diversion box HDB-8 facility. In addition to the PROCESS AREAS listed in the SAR, Building 299-H and the Effluent Transfer Facility (ETF) are also included in the scope.

  13. ROBUST ESTIMATION OF MEAN AND VARIANCE USING ENVIRONMENTAL DATA SETS WITH BELOW DETECTION LIMIT OBSERVATIONS

    Science.gov (United States)

    Scientists, especially environmental scientists often encounter trace level concentrations that are typically reported as less than a certain limit of detection, L. Type 1, left-censored data arise when certain low values lying below L are ignored or unknown as they cannot be mea...

  14. Level-set simulations of buoyancy-driven motion of single and multiple bubbles

    International Nuclear Information System (INIS)

    Balcázar, Néstor; Lehmkuhl, Oriol; Jofre, Lluís; Oliva, Assensi

    2015-01-01

    Highlights: • A conservative level-set method is validated and verified. • An extensive study of buoyancy-driven motion of single bubbles is performed. • The interactions of two spherical and ellipsoidal bubbles is studied. • The interaction of multiple bubbles is simulated in a vertical channel. - Abstract: This paper presents a numerical study of buoyancy-driven motion of single and multiple bubbles by means of the conservative level-set method. First, an extensive study of the hydrodynamics of single bubbles rising in a quiescent liquid is performed, including its shape, terminal velocity, drag coefficients and wake patterns. These results are validated against experimental and numerical data well established in the scientific literature. Then, a further study on the interaction of two spherical and ellipsoidal bubbles is performed for different orientation angles. Finally, the interaction of multiple bubbles is explored in a periodic vertical channel. The results show that the conservative level-set approach can be used for accurate modelling of bubble dynamics. Moreover, it is demonstrated that the present method is numerically stable for a wide range of Morton and Reynolds numbers.

  15. Multi-phase flow monitoring with electrical impedance tomography using level set based method

    International Nuclear Information System (INIS)

    Liu, Dong; Khambampati, Anil Kumar; Kim, Sin; Kim, Kyung Youn

    2015-01-01

    Highlights: • LSM has been used for shape reconstruction to monitor multi-phase flow using EIT. • Multi-phase level set model for conductivity is represented by two level set functions. • LSM handles topological merging and breaking naturally during evolution process. • To reduce the computational time, a narrowband technique was applied. • Use of narrowband and optimization approach results in efficient and fast method. - Abstract: In this paper, a level set-based reconstruction scheme is applied to multi-phase flow monitoring using electrical impedance tomography (EIT). The proposed scheme involves applying a narrowband level set method to solve the inverse problem of finding the interface between the regions having different conductivity values. The multi-phase level set model for the conductivity distribution inside the domain is represented by two level set functions. The key principle of the level set-based method is to implicitly represent the shape of interface as the zero level set of higher dimensional function and then solve a set of partial differential equations. The level set-based scheme handles topological merging and breaking naturally during the evolution process. It also offers several advantages compared to traditional pixel-based approach. Level set-based method for multi-phase flow is tested with numerical and experimental data. It is found that level set-based method has better reconstruction performance when compared to pixel-based method

  16. Mind-sets, low-level exposures, and research

    International Nuclear Information System (INIS)

    Sagan, L.A.

    1993-01-01

    Much of our environmental policy is based on the notion that carcinogenic agents are harmful at even minuscule doses. From where does this thinking come? What is the scientific evidence that supports such policy? Moreover, why is the public willing to buy into this? Or is it the other way around: Has the scientific community bought into a paradigm that has its origins in public imagery? Or, most likely, are there interactions between the two? It is essential that we find out whether or not there are risks associated with low-level exposures to radiation. The author can see three obvious areas where the future depends on better information: The increasing radiation exposures resulting from the use of medical diagnostic and therapeutic practices need to be properly evaluated for safety; Environmental policies, which direct enormous resources to the reduction of small radiation exposures, needs to be put on a firmer scientific basis; The future of nuclear energy, dependent as it is on public acceptance, may well rely upon a better understanding of low-dose effects. Nuclear energy could provide an important solution of global warming and other possible environmental hazards, but will probably not be implemented as long as fear of low-dose radiation persists. Although an established paradigm has great resilience, it cannot resist the onslaught of inconsistent scientific observations or of the social value system that supports it. Only new research will enable us to determine if a paradigm shift is in order here

  17. Human Rights: Its Meaning and Practice in Social Work Field Settings.

    Science.gov (United States)

    Steen, Julie A; Mann, Mary; Restivo, Nichole; Mazany, Shellene; Chapple, Reshawna

    2017-01-01

    The goal of the study reported in this article was to explore the conceptualizations of human rights and human rights practice among students and supervisors in social work field settings. Data were collected from 35 students and 48 supervisors through an online survey system that featured two open-ended questions regarding human rights issues in their agency and human rights practice tasks. Responses suggest that participants encountered human rights issues related to poverty, discrimination, participation/self-determination/autonomy, violence, dignity/respect, privacy, and freedom/liberty. They saw human rights practice as encompassing advocacy, service provision, assessment, awareness of threats to clients' rights, and the nature of the worker-client relationship. These results have implications for the social work profession, which has an opportunity to focus more intently on change efforts that support clients' rights. The study points to the possibilities of expanding the scope of the human rights competency within social work education and addressing the key human rights issues in field education. © 2016 National Association of Social Workers.

  18. Evaluating model simulations of 20th century sea-level rise. Part 1: global mean sea-level change

    NARCIS (Netherlands)

    Slangen, A.B.A.; Meyssignac, B.; Agosta, C.; Champollion, N.; Church, J.A.; Fettweis, X.; Ligtenberg, S.R.M.; Marzeion, B.; Melet, A.; Palmer, M.D.; Richter, K.; Roberts, C.D.; Spada, G.

    2017-01-01

    Sea level change is one of the major consequences of climate change and is projected to affect coastal communities around the world. Here, global mean sea level (GMSL) change estimated by 12 climate models from phase 5 of the World Climate Research Programme’s Climate Model Intercomparison Project

  19. Mechanisms of long-term mean sea level variability in the North Sea

    Science.gov (United States)

    Dangendorf, Sönke; Calafat, Francisco; Øie Nilsen, Jan Even; Richter, Kristin; Jensen, Jürgen

    2015-04-01

    We examine mean sea level (MSL) variations in the North Sea on timescales ranging from months to decades under the consideration of different forcing factors since the late 19th century. We use multiple linear regression models, which are validated for the second half of the 20th century against the output of a state-of-the-art tide+surge model (HAMSOM), to determine the barotropic response of the ocean to fluctuations in atmospheric forcing. We demonstrate that local atmospheric forcing mainly triggers MSL variability on timescales up to a few years, with the inverted barometric effect dominating the variability along the UK and Norwegian coastlines and wind (piling up the water along the coast) controlling the MSL variability in the south from Belgium up to Denmark. However, in addition to the large inter-annual sea level variability there is also a considerable fraction of decadal scale variability. We show that on decadal timescales MSL variability in the North Sea mainly reflects steric changes, which are mostly remotely forced. A spatial correlation analysis of altimetry observations and baroclinic ocean model outputs suggests evidence for a coherent signal extending from the Norwegian shelf down to the Canary Islands. This supports the theory of longshore wind forcing along the eastern boundary of the North Atlantic causing coastally trapped waves to propagate along the continental slope. With a combination of oceanographic and meteorological measurements we demonstrate that ~80% of the decadal sea level variability in the North Sea can be explained as response of the ocean to longshore wind forcing, including boundary wave propagation in the Northeast Atlantic. These findings have important implications for (i) detecting significant accelerations in North Sea MSL, (ii) the conceptual set up of regional ocean models in terms of resolution and boundary conditions, and (iii) the development of adequate and realistic regional climate change projections.

  20. A Variational Level Set Approach Based on Local Entropy for Image Segmentation and Bias Field Correction.

    Science.gov (United States)

    Tang, Jian; Jiang, Xiaoliang

    2017-01-01

    Image segmentation has always been a considerable challenge in image analysis and understanding due to the intensity inhomogeneity, which is also commonly known as bias field. In this paper, we present a novel region-based approach based on local entropy for segmenting images and estimating the bias field simultaneously. Firstly, a local Gaussian distribution fitting (LGDF) energy function is defined as a weighted energy integral, where the weight is local entropy derived from a grey level distribution of local image. The means of this objective function have a multiplicative factor that estimates the bias field in the transformed domain. Then, the bias field prior is fully used. Therefore, our model can estimate the bias field more accurately. Finally, minimization of this energy function with a level set regularization term, image segmentation, and bias field estimation can be achieved. Experiments on images of various modalities demonstrated the superior performance of the proposed method when compared with other state-of-the-art approaches.

  1. High-level radioactive waste management. A means to social consensus

    International Nuclear Information System (INIS)

    Pierce, B.; Hill, D.

    1984-01-01

    The problem of safely disposing of high-level radioactive waste is not new, but it is becoming more pressing as the temporary storage facilities of public utilities run out. The technical questions of how best to immobilize these wastes for many centuries have been studied for years and many feel that these problems are solved, or nearly so. In the USA many states have set up roadblocks to the federal waste management programme, however, and it is clear that social consensus must be reached for any waste disposal programme to be successful. The Nuclear Waste Policy Act of 1982 provides a long needed framework for reaching this consensus, giving the states unprecedented access to federal decision making. The rights of the states in a process of co-operation and consultation are clearly defined by the Act, but the means by which the states exercise these rights are left entirely to them. We examine the structures, methods and goals open to the states, and recommend a rationale for the state decision process defining the roles of the governor and legislature. (author)

  2. High-level radioactive wste management: a means to social consensus

    International Nuclear Information System (INIS)

    Pierce, B.; Hill, D.; Haefele, E.T.

    1983-01-01

    The problem of safely disposing of high-level radioactive waste is not new, but it is becoming more pressing as the temporary storage facilities of public utilities run out. The technical questions of how best to immobilize these wastes for many centuries have been studied for years and many feel that these problems are solved, or nearly so. Many states have set up roadblocks to the federal waste management program, however, and it is clear that social consensus must be reached for any waste disposal program to be successful. The Nuclear Waste Policy Act of 1982 provides a long-needed framework for reaching this consensus, giving the states unprecedented access to federal decision-making. The rights of the states in a process of cooperation and consultation are clearly defined by the Act, but the means by which the states exercise those rights are left entirely to them. We examine the structures, methods, and goals open to the states, and recommend a rationale for the state decision process defining the roles of the governor and legislature

  3. Mean glucose level is not an independent risk factor for mortality in mixed ICU patients

    NARCIS (Netherlands)

    Ligtenberg, JJM; Meijering, S; Stienstra, Y; van der Horst, ICC; Vogelzang, M; Nijsten, MWN; Tulleken, JE; Zijlstra, JG

    Objective: To find out if there is an association between hyperglycaemia and mortality in mixed ICU patients. Design and setting: Retrospective cohort study over a 2-year period at the medical ICU of a university hospital. Measurements: Admission glucose, maximum and mean glucose, length of stay,

  4. Examining the Reliability of Interval Level Data Using Root Mean Square Differences and Concordance Correlation Coefficients

    Science.gov (United States)

    Barchard, Kimberly A.

    2012-01-01

    This article introduces new statistics for evaluating score consistency. Psychologists usually use correlations to measure the degree of linear relationship between 2 sets of scores, ignoring differences in means and standard deviations. In medicine, biology, chemistry, and physics, a more stringent criterion is often used: the extent to which…

  5. Inter-comparison of stratospheric mean-meridional circulation and eddy mixing among six reanalysis data sets

    Directory of Open Access Journals (Sweden)

    K. Miyazaki

    2016-05-01

    Full Text Available The stratospheric mean-meridional circulation (MMC and eddy mixing are compared among six meteorological reanalysis data sets: NCEP-NCAR, NCEP-CFSR, ERA-40, ERA-Interim, JRA-25, and JRA-55 for the period 1979–2012. The reanalysis data sets produced using advanced systems (i.e., NCEP-CFSR, ERA-Interim, and JRA-55 generally reveal a weaker MMC in the Northern Hemisphere (NH compared with those produced using older systems (i.e., NCEP/NCAR, ERA-40, and JRA-25. The mean mixing strength differs largely among the data products. In the NH lower stratosphere, the contribution of planetary-scale mixing is larger in the new data sets than in the old data sets, whereas that of small-scale mixing is weaker in the new data sets. Conventional data assimilation techniques introduce analysis increments without maintaining physical balance, which may have caused an overly strong MMC and spurious small-scale eddies in the old data sets. At the NH mid-latitudes, only ERA-Interim reveals a weakening MMC trend in the deep branch of the Brewer–Dobson circulation (BDC. The relative importance of the eddy mixing compared with the mean-meridional transport in the subtropical lower stratosphere shows increasing trends in ERA-Interim and JRA-55; this together with the weakened MMC in the deep branch may imply an increasing age-of-air (AoA in the NH middle stratosphere in ERA-Interim. Overall, discrepancies between the different variables and trends therein as derived from the different reanalyses are still relatively large, suggesting that more investments in these products are needed in order to obtain a consolidated picture of observed changes in the BDC and the mechanisms that drive them.

  6. A local level set method based on a finite element method for unstructured meshes

    International Nuclear Information System (INIS)

    Ngo, Long Cu; Choi, Hyoung Gwon

    2016-01-01

    A local level set method for unstructured meshes has been implemented by using a finite element method. A least-square weighted residual method was employed for implicit discretization to solve the level set advection equation. By contrast, a direct re-initialization method, which is directly applicable to the local level set method for unstructured meshes, was adopted to re-correct the level set function to become a signed distance function after advection. The proposed algorithm was constructed such that the advection and direct reinitialization steps were conducted only for nodes inside the narrow band around the interface. Therefore, in the advection step, the Gauss–Seidel method was used to update the level set function using a node-by-node solution method. Some benchmark problems were solved by using the present local level set method. Numerical results have shown that the proposed algorithm is accurate and efficient in terms of computational time

  7. Transport and diffusion of material quantities on propagating interfaces via level set methods

    CERN Document Server

    Adalsteinsson, D

    2003-01-01

    We develop theory and numerical algorithms to apply level set methods to problems involving the transport and diffusion of material quantities in a level set framework. Level set methods are computational techniques for tracking moving interfaces; they work by embedding the propagating interface as the zero level set of a higher dimensional function, and then approximate the solution of the resulting initial value partial differential equation using upwind finite difference schemes. The traditional level set method works in the trace space of the evolving interface, and hence disregards any parameterization in the interface description. Consequently, material quantities on the interface which themselves are transported under the interface motion are not easily handled in this framework. We develop model equations and algorithmic techniques to extend the level set method to include these problems. We demonstrate the accuracy of our approach through a series of test examples and convergence studies.

  8. Transport and diffusion of material quantities on propagating interfaces via level set methods

    International Nuclear Information System (INIS)

    Adalsteinsson, David; Sethian, J.A.

    2003-01-01

    We develop theory and numerical algorithms to apply level set methods to problems involving the transport and diffusion of material quantities in a level set framework. Level set methods are computational techniques for tracking moving interfaces; they work by embedding the propagating interface as the zero level set of a higher dimensional function, and then approximate the solution of the resulting initial value partial differential equation using upwind finite difference schemes. The traditional level set method works in the trace space of the evolving interface, and hence disregards any parameterization in the interface description. Consequently, material quantities on the interface which themselves are transported under the interface motion are not easily handled in this framework. We develop model equations and algorithmic techniques to extend the level set method to include these problems. We demonstrate the accuracy of our approach through a series of test examples and convergence studies

  9. A local level set method based on a finite element method for unstructured meshes

    Energy Technology Data Exchange (ETDEWEB)

    Ngo, Long Cu; Choi, Hyoung Gwon [School of Mechanical Engineering, Seoul National University of Science and Technology, Seoul (Korea, Republic of)

    2016-12-15

    A local level set method for unstructured meshes has been implemented by using a finite element method. A least-square weighted residual method was employed for implicit discretization to solve the level set advection equation. By contrast, a direct re-initialization method, which is directly applicable to the local level set method for unstructured meshes, was adopted to re-correct the level set function to become a signed distance function after advection. The proposed algorithm was constructed such that the advection and direct reinitialization steps were conducted only for nodes inside the narrow band around the interface. Therefore, in the advection step, the Gauss–Seidel method was used to update the level set function using a node-by-node solution method. Some benchmark problems were solved by using the present local level set method. Numerical results have shown that the proposed algorithm is accurate and efficient in terms of computational time.

  10. A comparison and evaluation between ICESat/GLAS altimetry and mean sea level in Thailand

    Science.gov (United States)

    Naksen, Didsaphan; Yang, Dong Kai

    2015-10-01

    Surface elevation is one of the importance information for GIS. Usually surface elevation can acquired from many sources such as satellite imageries, aerial photograph, SAR data or LiDAR by photogrammetry, remote sensing methodology. However the most trust information describe the actual surface elevation is Leveling from terrestrial survey. Leveling is giving the highest accuracy but in the other hand is also long period process spending a lot of budget and resources, moreover the LiDAR technology is new era to measure surface elevation. ICESat/GLAS is spaceborne LiDAR platform, a scientific satellite lunched by NASA in 2003. The study area was located at the middle part of Thailand between 12. ° - 14° North and 98° -100° East Latitude and Longitude. The main idea is to compare and evaluate about elevation between ICESat/GLAS Altimetry and mean sea level of Thailand. Data are collected from various sources, including the ICESat/GLAS altimetry data product from NASA, mean sea level from Royal Thai Survey Department (RTSD). For methodology, is to transform ICESat GLA14 from TOPX/Poseidon-Jason ellipsoid to WGS84 ellipsoid. In addition, ICESat/GLAS altimetry that extracted form centroid of laser footprint and mean sea level were compared and evaluated by 1st Layer National Vertical Reference Network. The result is shown that generally the range of elevation between ICESat/GLAS and mean sea level is wildly from 0. 8 to 25 meters in study area.

  11. An improved level set method for brain MR images segmentation and bias correction.

    Science.gov (United States)

    Chen, Yunjie; Zhang, Jianwei; Macione, Jim

    2009-10-01

    Intensity inhomogeneities cause considerable difficulty in the quantitative analysis of magnetic resonance (MR) images. Thus, bias field estimation is a necessary step before quantitative analysis of MR data can be undertaken. This paper presents a variational level set approach to bias correction and segmentation for images with intensity inhomogeneities. Our method is based on an observation that intensities in a relatively small local region are separable, despite of the inseparability of the intensities in the whole image caused by the overall intensity inhomogeneity. We first define a localized K-means-type clustering objective function for image intensities in a neighborhood around each point. The cluster centers in this objective function have a multiplicative factor that estimates the bias within the neighborhood. The objective function is then integrated over the entire domain to define the data term into the level set framework. Our method is able to capture bias of quite general profiles. Moreover, it is robust to initialization, and thereby allows fully automated applications. The proposed method has been used for images of various modalities with promising results.

  12. Forecasting the Global Mean Sea Level, a Continuous-Time State-Space Approach

    DEFF Research Database (Denmark)

    Boldrini, Lorenzo

    In this paper we propose a continuous-time, Gaussian, linear, state-space system to model the relation between global mean sea level (GMSL) and the global mean temperature (GMT), with the aim of making long-term projections for the GMSL. We provide a justification for the model specification based......) and the temperature reconstruction from Hansen et al. (2010). We compare the forecasting performance of the proposed specification to the procedures developed in Rahmstorf (2007b) and Vermeer and Rahmstorf (2009). Finally, we compute projections for the sea-level rise conditional on the 21st century SRES temperature...

  13. An efficient, scalable, and adaptable framework for solving generic systems of level-set PDEs

    Directory of Open Access Journals (Sweden)

    Kishore R. Mosaliganti

    2013-12-01

    Full Text Available In the last decade, level-set methods have been actively developed for applications in image registration, segmentation, tracking, and reconstruction. However, the development of a wide variety of level-set PDEs and their numerical discretization schemes, coupled with hybrid combinations of PDE terms, stopping criteria, and reinitialization strategies, has created a software logistics problem. In the absence of an integrative design, current toolkits support only specific types of level-set implementations which restrict future algorithm development since extensions require significant code duplication and effort. In the new NIH/NLM Insight Toolkit (ITK v4 architecture, we implemented a level-set software design that is flexible to different numerical (continuous, discrete, and sparse and grid representations (point, mesh, and image-based. Given that a generic PDE is a summation of different terms, we used a set of linked containers to which level-set terms can be added or deleted at any point in the evolution process. This container-based approach allows the user to explore and customize terms in the level-set equation at compile-time in a flexible manner. The framework is optimized so that repeated computations of common intensity functions (e.g. gradient and Hessians across multiple terms is eliminated. The framework further enables the evolution of multiple level-sets for multi-object segmentation and processing of large datasets. For doing so, we restrict level-set domains to subsets of the image domain and use multithreading strategies to process groups of subdomains or level-set functions. Users can also select from a variety of reinitialization policies and stopping criteria. Finally, we developed a visualization framework that shows the evolution of a level-set in real-time to help guide algorithm development and parameter optimization. We demonstrate the power of our new framework using confocal microscopy images of cells in a

  14. A LEVEL SET BASED SHAPE OPTIMIZATION METHOD FOR AN ELLIPTIC OBSTACLE PROBLEM

    KAUST Repository

    Burger, Martin; Matevosyan, Norayr; Wolfram, Marie-Therese

    2011-01-01

    analysis of the level set method in terms of viscosity solutions. To our knowledge this is the first complete analysis of a level set method for a nonlocal shape optimization problem. Finally, we discuss the implementation of the methods and illustrate its

  15. Millennial cycles of mean sea level excited by earth´s orbital variations

    Czech Academy of Sciences Publication Activity Database

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

    2015-01-01

    Roč. 12, č. 3 (2015), s. 259-266 ISSN 1214-9705 R&D Projects: GA ČR GA13-15943S Institutional support: RVO:67985815 Keywords : millenial cycles * mean sea level * Earth's insolation Subject RIV: BN - Astronomy, Celestial Mechanics, Astrophysics Impact factor: 0.561, year: 2015

  16. Decadal Cycles of Earth Rotation, Mean Sea Level and Climate, Excited by Solar Activity

    Czech Academy of Sciences Publication Activity Database

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

    2017-01-01

    Roč. 14, č. 2 (2017), s. 241-250 ISSN 1214-9705 R&D Projects: GA ČR GA13-15943S Institutional support: RVO:67985815 Keywords : Earth rotation * solar activity * mean sea level Subject RIV: DE - Earth Magnetism, Geodesy, Geography OBOR OECD: Physical geography Impact factor: 0.699, year: 2016

  17. Coping across the Transition to Adolescence: Evidence of Interindividual Consistency and Mean-Level Change

    Science.gov (United States)

    Valiente, Carlos; Eisenberg, Nancy; Fabes, Richard A.; Spinrad, Tracy L.; Sulik, Michael J.

    2015-01-01

    The goal of this study was to examine various forms of coping across the transition to adolescence, with a focus on interindividual (correlational) consistency of coping and mean-level changes in coping. Adolescents' emotional coping, problem solving, positive cognitive restructuring, avoidance, and support seeking in response to everyday…

  18. Anxiety towards Mathematics and Educational Level: A Study on Means Differences

    Science.gov (United States)

    Escalera-Chávez, Milka Elena; García-Santillán, Arturo; Córdova-Rangel, Arturo; González-Gómez, Santiago; Tejada-Peña, Esmeralda

    2016-01-01

    The aim of this research work is to analyze whether there is a difference in the degree of anxiety towards mathematics among students of different educational levels. The study is not experimental and cross sectional, and it is based on difference of means between groups. The sample is not probabilistic, and consisted of 226 students from…

  19. Glycated albumin is set lower in relation to plasma glucose levels in patients with Cushing's syndrome.

    Science.gov (United States)

    Kitamura, Tetsuhiro; Otsuki, Michio; Tamada, Daisuke; Tabuchi, Yukiko; Mukai, Kosuke; Morita, Shinya; Kasayama, Soji; Shimomura, Iichiro; Koga, Masafumi

    2013-09-23

    Glycated albumin (GA) is an indicator of glycemic control, which has some specific characters in comparison with HbA1c. Since glucocorticoids (GC) promote protein catabolism including serum albumin, GC excess state would influence GA levels. We therefore investigated GA levels in patients with Cushing's syndrome. We studied 16 patients with Cushing's syndrome (8 patients had diabetes mellitus and the remaining 8 patients were non-diabetic). Thirty-two patients with type 2 diabetes mellitus and 32 non-diabetic subjects matched for age, sex and BMI were used as controls. In the patients with Cushing's syndrome, GA was significantly correlated with HbA1c, but the regression line shifted downwards as compared with the controls. The GA/HbA1c ratio in the patients with Cushing's syndrome was also significantly lower than the controls. HbA1c in the non-diabetic patients with Cushing's syndrome was not different from the non-diabetic controls, whereas GA was significantly lower. In 7 patients with Cushing's syndrome who performed self-monitoring of blood glucose, the measured HbA1c was matched with HbA1c estimated from mean blood glucose, whereas the measured GA was significantly lower than the estimated GA. We clarified that GA is set lower in relation to plasma glucose levels in patients with Cushing's syndrome. Copyright © 2013 Elsevier B.V. All rights reserved.

  20. Frequency-Locked Detector Threshold Setting Criteria Based on Mean-Time-To-Lose-Lock (MTLL) for GPS Receivers.

    Science.gov (United States)

    Jin, Tian; Yuan, Heliang; Zhao, Na; Qin, Honglei; Sun, Kewen; Ji, Yuanfa

    2017-12-04

    Frequency-locked detector (FLD) has been widely utilized in tracking loops of Global Positioning System (GPS) receivers to indicate their locking status. The relation between FLD and lock status has been seldom discussed. The traditional PLL experience is not suitable for FLL. In this paper, the threshold setting criteria for frequency-locked detector in the GPS receiver has been proposed by analyzing statistical characteristic of FLD output. The approximate probability distribution of frequency-locked detector is theoretically derived by using a statistical approach, which reveals the relationship between probabilities of frequency-locked detector and the carrier-to-noise ratio ( C / N ₀) of the received GPS signal. The relationship among mean-time-to-lose-lock (MTLL), detection threshold and lock probability related to C / N ₀ can be further discovered by utilizing this probability. Therefore, a theoretical basis for threshold setting criteria in frequency locked loops for GPS receivers is provided based on mean-time-to-lose-lock analysis.

  1. Mean platelet volume and red cell distribution width levels in initial evaluation of panic disorder

    Directory of Open Access Journals (Sweden)

    Asoglu M

    2016-09-01

    Full Text Available Mehmet Asoglu,1 Mehmet Aslan,2 Okan Imre,1 Yuksel Kivrak,3 Oznur Akil,1 Emin Savik,4 Hasan Buyukaslan,5 Ulker Fedai,1 Abdurrahman Altındag6 1Department of Psychiatry, Faculty of Medicine, Harran University, Sanliurfa, 2Department of Internal Medicine, Faculty of Medicine, Yuzuncu Yil University, Van, 3Department of Psychiatry, Faculty of Medicine, Kafkas University, Kars, 4Department of Clinical Biochemistry, Faculty of Medicine, Harran University, 5Department of Emergency Medicine, Faculty of Medicine, Harran University, Sanliurfa, 6Department of Psychiatry, Faculty of Medicine, Gaziantep University, Gaziantep, Turkey Background: As the relationship between psychological stress and platelet activation has been widely studied in recent years, activated platelets lead to certain biochemical changes, which occur in the brain in patients with mental disorders. However, data relating to the mean platelet volume (MPV in patients with panic disorder (PD are both limited and controversial. Herein, we aimed to evaluate, for the first time, the red cell distribution width (RDW levels combined with MPV levels in patients with PD.Patients and methods: Between January 2012 and June 2015, data of 30 treatment-naïve patients (16 females, 14 males; mean age: 37±10 years; range: 18–59 years who were diagnosed with PD and 25 age- and sex-matched healthy volunteers (10 females, 15 males; mean age: 36±13 years; range: 18–59 years (control group were retrospectively analyzed. The white blood cell count (WBC, MPV, and RDW levels were measured in both groups.Results: The mean WBC, MPV, and RDW levels were 9,173.03±2,400.31/mm3, 8.19±1.13 fl, and 12.47±1.14%, respectively, in the PD group. These values were found to be 7,090.24±1,032.61, 6.85±0.67, and 11.63±0.85, respectively, in the healthy controls. The WBC, MPV, and RDW levels were significantly higher in the patients with PD compared to the healthy controls (P=0.001, P=0.001, and P=0

  2. A level set approach for shock-induced α-γ phase transition of RDX

    Science.gov (United States)

    Josyula, Kartik; Rahul; De, Suvranu

    2018-02-01

    We present a thermodynamically consistent level sets approach based on regularization energy functional which can be directly incorporated into a Galerkin finite element framework to model interface motion. The regularization energy leads to a diffusive form of flux that is embedded within the level sets evolution equation which maintains the signed distance property of the level set function. The scheme is shown to compare well with the velocity extension method in capturing the interface position. The proposed level sets approach is employed to study the α-γphase transformation in RDX single crystal shocked along the (100) plane. Example problems in one and three dimensions are presented. We observe smooth evolution of the phase interface along the shock direction in both models. There is no diffusion of the interface during the zero level set evolution in the three dimensional model. The level sets approach is shown to capture the characteristics of the shock-induced α-γ phase transformation such as stress relaxation behind the phase interface and the finite time required for the phase transformation to complete. The regularization energy based level sets approach is efficient, robust, and easy to implement.

  3. Cooperative Fuzzy Games Approach to Setting Target Levels of ECs in Quality Function Deployment

    Directory of Open Access Journals (Sweden)

    Zhihui Yang

    2014-01-01

    Full Text Available Quality function deployment (QFD can provide a means of translating customer requirements (CRs into engineering characteristics (ECs for each stage of product development and production. The main objective of QFD-based product planning is to determine the target levels of ECs for a new product or service. QFD is a breakthrough tool which can effectively reduce the gap between CRs and a new product/service. Even though there are conflicts among some ECs, the objective of developing new product is to maximize the overall customer satisfaction. Therefore, there may be room for cooperation among ECs. A cooperative game framework combined with fuzzy set theory is developed to determine the target levels of the ECs in QFD. The key to develop the model is the formulation of the bargaining function. In the proposed methodology, the players are viewed as the membership functions of ECs to formulate the bargaining function. The solution for the proposed model is Pareto-optimal. An illustrated example is cited to demonstrate the application and performance of the proposed approach.

  4. Cooperative fuzzy games approach to setting target levels of ECs in quality function deployment.

    Science.gov (United States)

    Yang, Zhihui; Chen, Yizeng; Yin, Yunqiang

    2014-01-01

    Quality function deployment (QFD) can provide a means of translating customer requirements (CRs) into engineering characteristics (ECs) for each stage of product development and production. The main objective of QFD-based product planning is to determine the target levels of ECs for a new product or service. QFD is a breakthrough tool which can effectively reduce the gap between CRs and a new product/service. Even though there are conflicts among some ECs, the objective of developing new product is to maximize the overall customer satisfaction. Therefore, there may be room for cooperation among ECs. A cooperative game framework combined with fuzzy set theory is developed to determine the target levels of the ECs in QFD. The key to develop the model is the formulation of the bargaining function. In the proposed methodology, the players are viewed as the membership functions of ECs to formulate the bargaining function. The solution for the proposed model is Pareto-optimal. An illustrated example is cited to demonstrate the application and performance of the proposed approach.

  5. CT liver volumetry using geodesic active contour segmentation with a level-set algorithm

    Science.gov (United States)

    Suzuki, Kenji; Epstein, Mark L.; Kohlbrenner, Ryan; Obajuluwa, Ademola; Xu, Jianwu; Hori, Masatoshi; Baron, Richard

    2010-03-01

    Automatic liver segmentation on CT images is challenging because the liver often abuts other organs of a similar density. Our purpose was to develop an accurate automated liver segmentation scheme for measuring liver volumes. We developed an automated volumetry scheme for the liver in CT based on a 5 step schema. First, an anisotropic smoothing filter was applied to portal-venous phase CT images to remove noise while preserving the liver structure, followed by an edge enhancer to enhance the liver boundary. By using the boundary-enhanced image as a speed function, a fastmarching algorithm generated an initial surface that roughly estimated the liver shape. A geodesic-active-contour segmentation algorithm coupled with level-set contour-evolution refined the initial surface so as to more precisely fit the liver boundary. The liver volume was calculated based on the refined liver surface. Hepatic CT scans of eighteen prospective liver donors were obtained under a liver transplant protocol with a multi-detector CT system. Automated liver volumes obtained were compared with those manually traced by a radiologist, used as "gold standard." The mean liver volume obtained with our scheme was 1,520 cc, whereas the mean manual volume was 1,486 cc, with the mean absolute difference of 104 cc (7.0%). CT liver volumetrics based on an automated scheme agreed excellently with "goldstandard" manual volumetrics (intra-class correlation coefficient was 0.95) with no statistically significant difference (p(F<=f)=0.32), and required substantially less completion time. Our automated scheme provides an efficient and accurate way of measuring liver volumes.

  6. Reservoir characterisation by a binary level set method and adaptive multiscale estimation

    Energy Technology Data Exchange (ETDEWEB)

    Nielsen, Lars Kristian

    2006-01-15

    The main focus of this work is on estimation of the absolute permeability as a solution of an inverse problem. We have both considered a single-phase and a two-phase flow model. Two novel approaches have been introduced and tested numerical for solving the inverse problems. The first approach is a multi scale zonation technique which is treated in Paper A. The purpose of the work in this paper is to find a coarse scale solution based on production data from wells. In the suggested approach, the robustness of an already developed method, the adaptive multi scale estimation (AME), has been improved by utilising information from several candidate solutions generated by a stochastic optimizer. The new approach also suggests a way of combining a stochastic and a gradient search method, which in general is a problematic issue. The second approach is a piecewise constant level set approach and is applied in Paper B, C, D and E. Paper B considers the stationary single-phase problem, while Paper C, D and E use a two-phase flow model. In the two-phase flow problem we have utilised information from both production data in wells and spatially distributed data gathered from seismic surveys. Due to the higher content of information provided by the spatially distributed data, we search solutions on a slightly finer scale than one typically does with only production data included. The applied level set method is suitable for reconstruction of fields with a supposed known facies-type of solution. That is, the solution should be close to piecewise constant. This information is utilised through a strong restriction of the number of constant levels in the estimate. On the other hand, the flexibility in the geometries of the zones is much larger for this method than in a typical zonation approach, for example the multi scale approach applied in Paper A. In all these papers, the numerical studies are done on synthetic data sets. An advantage of synthetic data studies is that the true

  7. Paired structures, imprecision types and two-level knowledge representation by means of opposites

    DEFF Research Database (Denmark)

    Rodríguez, J. Tinguaro; Franco de los Ríos, Camilo; Gómez, Daniel

    2016-01-01

    Opposition-based models are a current hot-topic in knowledge representation. The point of this paper is to suggest that opposition can be in fact introduced at two different levels, those of the predicates of interest being represented (as short/tall) and of the logical references (true/false) used...... to evaluate the verification of the former. We study this issue by means of the consideration of different paired structures at each level. We also pay attention at how different types of fuzziness may be introduced in these paired structures to model imprecision and lack of knowledge. As a consequence, we...

  8. Mean-field energy-level shifts and dielectric properties of strongly polarized Rydberg gases

    OpenAIRE

    Zhelyazkova, V.; Jirschik, R.; Hogan, S. D.

    2016-01-01

    Mean-field energy-level shifts arising as a result of strong electrostatic dipole interactions within dilute gases of polarized helium Rydberg atoms have been probed by microwave spectroscopy. The Rydberg states studied had principal quantum numbers n=70 and 72, and electric dipole moments of up to 14 050 D, and were prepared in pulsed supersonic beams at particle number densities on the order of 108 cm−3. Comparisons of the experimental data with the results of Monte Carlo calculations highl...

  9. PERCEPTION LEVEL EVALUATION OF RADIO ELECTRONIC MEANS TO A PULSE OF ELECTROMAGNETIC RADIATION

    Directory of Open Access Journals (Sweden)

    2016-01-01

    Full Text Available The method for evaluating the perception level of electronic means to pulsed electromagnetic radiation is consid- ered in this article. The electromagnetic wave penetration mechanism towards the elements of electronic systems and the impact on them are determined by the intensity of the radiation field on the elements of electronic systems. The impact of electromagnetic radiation pulses to the electronic systems refers to physical and analytical parameters of the relationship between exposure to pulses of electromagnetic radiation and the sample parameters of electronic systems. A physical and mathematical model of evaluating the perception level of electronic means to pulsed electromagnetic radiation is given. The developed model was based on the physics of electronics means failure which represents the description of electro- magnetic, electric and thermal processes that lead to the degradation of the original structure of the apparatus elements. The conditions that lead to the total equation electronic systems functional destruction when exposed to electromagnetic radia- tion pulses are described. The internal characteristics of the component elements that respond to the damaging effects are considered. The ratio for the power failure is determined. A thermal breakdown temperature versus pulse duration of expo- sure at various power levels is obtained. The way of evaluation the reliability of electronic systems when exposed to pulses of electromagnetic radiation as a destructive factor is obtained.

  10. Research on classified real-time flood forecasting framework based on K-means cluster and rough set.

    Science.gov (United States)

    Xu, Wei; Peng, Yong

    2015-01-01

    This research presents a new classified real-time flood forecasting framework. In this framework, historical floods are classified by a K-means cluster according to the spatial and temporal distribution of precipitation, the time variance of precipitation intensity and other hydrological factors. Based on the classified results, a rough set is used to extract the identification rules for real-time flood forecasting. Then, the parameters of different categories within the conceptual hydrological model are calibrated using a genetic algorithm. In real-time forecasting, the corresponding category of parameters is selected for flood forecasting according to the obtained flood information. This research tests the new classified framework on Guanyinge Reservoir and compares the framework with the traditional flood forecasting method. It finds that the performance of the new classified framework is significantly better in terms of accuracy. Furthermore, the framework can be considered in a catchment with fewer historical floods.

  11. A LEVEL SET BASED SHAPE OPTIMIZATION METHOD FOR AN ELLIPTIC OBSTACLE PROBLEM

    KAUST Repository

    Burger, Martin

    2011-04-01

    In this paper, we construct a level set method for an elliptic obstacle problem, which can be reformulated as a shape optimization problem. We provide a detailed shape sensitivity analysis for this reformulation and a stability result for the shape Hessian at the optimal shape. Using the shape sensitivities, we construct a geometric gradient flow, which can be realized in the context of level set methods. We prove the convergence of the gradient flow to an optimal shape and provide a complete analysis of the level set method in terms of viscosity solutions. To our knowledge this is the first complete analysis of a level set method for a nonlocal shape optimization problem. Finally, we discuss the implementation of the methods and illustrate its behavior through several computational experiments. © 2011 World Scientific Publishing Company.

  12. The meaning of patient-nurse interaction for older women in healthcare settings: A Qualitative Descriptive Study.

    Science.gov (United States)

    Mize, Darcy

    2018-03-01

    The purpose of this study was to explore the meaning of patient-nurse interaction for older women receiving care in healthcare settings. Older women are often overlooked or misunderstood by the nurses caring for them. Some research exists on nurses' perception of their interaction with patients, yet few studies have described the meaning of such interaction from the patients' perspective. This was a pilot study using qualitative description as a methodology. Data were filtered through a lens of critical feminist theory to interpret interactions taking place in healthcare settings that are often characterised by paternalism. Seven women between the ages of 66 and 81 were interviewed using a semi-structured guide. Participants had a distinctive perspective on the experience of caring. Their expressions include stories of being cared for themselves by nurses as well as historical recalls of being the one-caring for family members. In these combined stories, the contrast between the nurses who held caring in primacy and those who were distinctly uncaring sheds light on the importance of cultivating a moral ideal of caring and respect for personhood. A population of older women who potentially face disabling conditions must rely on direct, meaningful, interaction with nurses to successfully navigate the healthcare system. The findings suggest that these women did not have consistent access to such interaction. The gathering and interpretation of new narratives about patient-nurse interaction for older women could lead to a deeper understanding of power and civility as it impacts a caring relationship. Further research using a theoretical lens of critical feminism has implications for improving healthcare delivery for older women worldwide. © 2017 John Wiley & Sons Ltd.

  13. Being in togetherness: meanings of encounters within primary healtcare setting for patients living with long-term illness.

    Science.gov (United States)

    Nygren Zotterman, Anna; Skär, Lisa; Olsson, Malin; Söderberg, Siv

    2016-10-01

    The aim of this study was to elucidate meanings of encounters for patients with long-term illness within the primary healthcare setting. Good encounters can be crucial for patients in terms of how they view their quality of care. Therefore, it is important to understand meanings of interactions between patients and healthcare personnel. A phenomenological hermeneutic method was used to analyse the interviews. Narrative interviews with ten patients with long-term illness were performed, with a focus on their encounters with healthcare personnel within the primary healthcare setting. A phenomenological hermeneutical approach was used to interpret the interview texts. The results demonstrated that patients felt well when they were seen as an important person and felt welcomed by healthcare personnel. Information and follow-ups regarding the need for care were essential. Continuity with the healthcare personnel was one way to establish a relationship, which contributed to patients' feelings of being seen and understood. Good encounters were important for patients' feelings of health and well-being. Being met with mistrust, ignorance and nonchalance had negative effects on patients' perceived health and well-being and led to feelings of lower confidence regarding the care received. Patients described a great need to be confirmed and met with respect by healthcare personnel, which contributed to their sense of togetherness. Having a sense of togetherness strengthened patient well-being. By listening and responding to patients' needs and engaging in meetings with patients in a respectful manner, healthcare personnel can empower patients' feelings of health and well-being. Healthcare personnel need to be aware of the significance of these actions because they can make patients experience feelings of togetherness, even if patients meet with different care personnel at each visit. © 2016 John Wiley & Sons Ltd.

  14. An accurate conservative level set/ghost fluid method for simulating turbulent atomization

    International Nuclear Information System (INIS)

    Desjardins, Olivier; Moureau, Vincent; Pitsch, Heinz

    2008-01-01

    This paper presents a novel methodology for simulating incompressible two-phase flows by combining an improved version of the conservative level set technique introduced in [E. Olsson, G. Kreiss, A conservative level set method for two phase flow, J. Comput. Phys. 210 (2005) 225-246] with a ghost fluid approach. By employing a hyperbolic tangent level set function that is transported and re-initialized using fully conservative numerical schemes, mass conservation issues that are known to affect level set methods are greatly reduced. In order to improve the accuracy of the conservative level set method, high order numerical schemes are used. The overall robustness of the numerical approach is increased by computing the interface normals from a signed distance function reconstructed from the hyperbolic tangent level set by a fast marching method. The convergence of the curvature calculation is ensured by using a least squares reconstruction. The ghost fluid technique provides a way of handling the interfacial forces and large density jumps associated with two-phase flows with good accuracy, while avoiding artificial spreading of the interface. Since the proposed approach relies on partial differential equations, its implementation is straightforward in all coordinate systems, and it benefits from high parallel efficiency. The robustness and efficiency of the approach is further improved by using implicit schemes for the interface transport and re-initialization equations, as well as for the momentum solver. The performance of the method is assessed through both classical level set transport tests and simple two-phase flow examples including topology changes. It is then applied to simulate turbulent atomization of a liquid Diesel jet at Re=3000. The conservation errors associated with the accurate conservative level set technique are shown to remain small even for this complex case

  15. A simple mass-conserved level set method for simulation of multiphase flows

    Science.gov (United States)

    Yuan, H.-Z.; Shu, C.; Wang, Y.; Shu, S.

    2018-04-01

    In this paper, a modified level set method is proposed for simulation of multiphase flows with large density ratio and high Reynolds number. The present method simply introduces a source or sink term into the level set equation to compensate the mass loss or offset the mass increase. The source or sink term is derived analytically by applying the mass conservation principle with the level set equation and the continuity equation of flow field. Since only a source term is introduced, the application of the present method is as simple as the original level set method, but it can guarantee the overall mass conservation. To validate the present method, the vortex flow problem is first considered. The simulation results are compared with those from the original level set method, which demonstrates that the modified level set method has the capability of accurately capturing the interface and keeping the mass conservation. Then, the proposed method is further validated by simulating the Laplace law, the merging of two bubbles, a bubble rising with high density ratio, and Rayleigh-Taylor instability with high Reynolds number. Numerical results show that the mass is a well-conserved by the present method.

  16. Evaluating healthcare priority setting at the meso level: A thematic review of empirical literature

    Science.gov (United States)

    Waithaka, Dennis; Tsofa, Benjamin; Barasa, Edwine

    2018-01-01

    Background: Decentralization of health systems has made sub-national/regional healthcare systems the backbone of healthcare delivery. These regions are tasked with the difficult responsibility of determining healthcare priorities and resource allocation amidst scarce resources. We aimed to review empirical literature that evaluated priority setting practice at the meso (sub-national) level of health systems. Methods: We systematically searched PubMed, ScienceDirect and Google scholar databases and supplemented these with manual searching for relevant studies, based on the reference list of selected papers. We only included empirical studies that described and evaluated, or those that only evaluated priority setting practice at the meso-level. A total of 16 papers were identified from LMICs and HICs. We analyzed data from the selected papers by thematic review. Results: Few studies used systematic priority setting processes, and all but one were from HICs. Both formal and informal criteria are used in priority-setting, however, informal criteria appear to be more perverse in LMICs compared to HICs. The priority setting process at the meso-level is a top-down approach with minimal involvement of the community. Accountability for reasonableness was the most common evaluative framework as it was used in 12 of the 16 studies. Efficiency, reallocation of resources and options for service delivery redesign were the most common outcome measures used to evaluate priority setting. Limitations: Our study was limited by the fact that there are very few empirical studies that have evaluated priority setting at the meso-level and there is likelihood that we did not capture all the studies. Conclusions: Improving priority setting practices at the meso level is crucial to strengthening health systems. This can be achieved through incorporating and adapting systematic priority setting processes and frameworks to the context where used, and making considerations of both process

  17. BACK MUSCLES STRENGTH DEVELOPMENT BY MEANS OF INCREASE AND DECREASE OF EFFORT LOAD DURING GIANT SETS IN BODYBUILDING FOR MASSES

    Directory of Open Access Journals (Sweden)

    TIMNEA OLIVIA

    2013-01-01

    Full Text Available Abstract The aim of the study is to highlight methodological issues on the back muscle strength development by combining methodological procedures in masses bodybuilding.Methods. The study was conducted in three stages over a period of two months (March-April 2011, performing three workouts per week, monitoring the effective use of strength exercises to develop back muscles in the same muscle area by means of giant sets during workouts. In this context, we conducted a case study in "Tonik Fitness Club" in Bucharest, applied to two athletes of 28 and 34 years old. We recorded subjects’ evolutions during the training session, using statistical and mathematical method and graphical representation method.Results. The study content highlights the training programs depending on muscle zone and the specific methodological aspects, the weekly training program per muscle groups, the stages of study carrying out, the test and control trials applied in terms of anthropometric measurements and of back muscle strength development, and the application of the methodical procedure of effort load increase and decrease within the giant sets in a training micro-cycle.Discussion. The study focused on the training programs over two months, monitoring statistically the development of back muscle strength through the application of the procedure of effort load increase and decrease during giant sets in bodybuilding for masses. From the analysis of training programs content we noticed that three giant sets of exercises were used, performed in four series; each exercise within the giant sets was applied by means of the procedure of increasing and decreasing effort load. Study results emphasize the anthropometric measurement results: the study subjects have the age mean of 24.75, with a size of 175.2 cm and a weight of 83.75 kg at initial testing and a decrease by 2.12 kg in final testing. Regarding the chest perimeter, the inspiration is averaging 89.5 in initial

  18. Mapping topographic structure in white matter pathways with level set trees.

    Directory of Open Access Journals (Sweden)

    Brian P Kent

    Full Text Available Fiber tractography on diffusion imaging data offers rich potential for describing white matter pathways in the human brain, but characterizing the spatial organization in these large and complex data sets remains a challenge. We show that level set trees--which provide a concise representation of the hierarchical mode structure of probability density functions--offer a statistically-principled framework for visualizing and analyzing topography in fiber streamlines. Using diffusion spectrum imaging data collected on neurologically healthy controls (N = 30, we mapped white matter pathways from the cortex into the striatum using a deterministic tractography algorithm that estimates fiber bundles as dimensionless streamlines. Level set trees were used for interactive exploration of patterns in the endpoint distributions of the mapped fiber pathways and an efficient segmentation of the pathways that had empirical accuracy comparable to standard nonparametric clustering techniques. We show that level set trees can also be generalized to model pseudo-density functions in order to analyze a broader array of data types, including entire fiber streamlines. Finally, resampling methods show the reliability of the level set tree as a descriptive measure of topographic structure, illustrating its potential as a statistical descriptor in brain imaging analysis. These results highlight the broad applicability of level set trees for visualizing and analyzing high-dimensional data like fiber tractography output.

  19. Statistical analysis of the acceleration of Baltic mean sea-level rise, 1900-2012

    Directory of Open Access Journals (Sweden)

    Birgit Hünicke

    2016-07-01

    Full Text Available We analyse annual mean sea-level records from tide-gauges located in the Baltic and parts of the North Sea with the aim of detecting an acceleration of sea-level rise over the 20textsuperscript{th} and 21textsuperscript{st} centuries. The acceleration is estimated as a (1 fit to a polynomial of order two in time, (2 a long-term linear increase in the rates computed over gliding overlapping decadal time segments, and (3 a long-term increase of the annual increments of sea level.The estimation methods (1 and (2 prove to be more powerful in detecting acceleration when tested with sea-level records produced in global climate model simulations. These methods applied to the Baltic-Sea tide-gauges are, however, not powerful enough to detect a significant acceleration in most of individual records, although most estimated accelerations are positive. This lack of detection of statistically significant acceleration at the individual tide-gauge level can be due to the high-level of local noise and not necessarily to the absence of acceleration.The estimated accelerations tend to be stronger in the north and east of the Baltic Sea. Two hypothesis to explain this spatial pattern have been explored. One is that this pattern reflects the slow-down of the Glacial Isostatic Adjustment. However, a simple estimation of this effect suggests that this slow-down cannot explain the estimated acceleration. The second hypothesis is related to the diminishing sea-ice cover over the 20textsuperscript{th} century. The melting o of less saline and colder sea-ice can lead to changes in sea-level. Also, the melting of sea-ice can reduce the number of missing values in the tide-gauge records in winter, potentially influencing the estimated trends and acceleration of seasonal mean sea-level This hypothesis cannot be ascertained either since the spatial pattern of acceleration computed for winter and summer separately are very similar. The all-station-average-record displays an

  20. Dose limits, constraints, reference levels. What does it mean for radiation protection?

    International Nuclear Information System (INIS)

    Breckow, J.

    2016-01-01

    The established concept of radiation protection with its basic principles justification, optimization, and limitation has proved its value and is going to be continued. In its deeper meaning, however, the concept is rather subtle and complex. Furthermore, in some aspects there remain some breaches or inconsistencies. This is just true for the terms dose limit, reference lever, and constraint that are tightly associated with the radiation protection principles. In order to guarantee the ability of radiation protection in whole extent, the subtle differences of meaning have to be communicated. There is a permanent need to defend the conceptual function of these terms against deliberate or undeliberate misinterpretations. Reference levels are definitely not the same as dose limits and they may not be misused as such. Any attempt to misinterpret fundamental radiation protection principles for selfish purposes should discouraged vigorously.

  1. Setting Healthcare Priorities at the Macro and Meso Levels: A Framework for Evaluation.

    Science.gov (United States)

    Barasa, Edwine W; Molyneux, Sassy; English, Mike; Cleary, Susan

    2015-09-16

    Priority setting in healthcare is a key determinant of health system performance. However, there is no widely accepted priority setting evaluation framework. We reviewed literature with the aim of developing and proposing a framework for the evaluation of macro and meso level healthcare priority setting practices. We systematically searched Econlit, PubMed, CINAHL, and EBSCOhost databases and supplemented this with searches in Google Scholar, relevant websites and reference lists of relevant papers. A total of 31 papers on evaluation of priority setting were identified. These were supplemented by broader theoretical literature related to evaluation of priority setting. A conceptual review of selected papers was undertaken. Based on a synthesis of the selected literature, we propose an evaluative framework that requires that priority setting practices at the macro and meso levels of the health system meet the following conditions: (1) Priority setting decisions should incorporate both efficiency and equity considerations as well as the following outcomes; (a) Stakeholder satisfaction, (b) Stakeholder understanding, (c) Shifted priorities (reallocation of resources), and (d) Implementation of decisions. (2) Priority setting processes should also meet the procedural conditions of (a) Stakeholder engagement, (b) Stakeholder empowerment, (c) Transparency, (d) Use of evidence, (e) Revisions, (f) Enforcement, and (g) Being grounded on community values. Available frameworks for the evaluation of priority setting are mostly grounded on procedural requirements, while few have included outcome requirements. There is, however, increasing recognition of the need to incorporate both consequential and procedural considerations in priority setting practices. In this review, we adapt an integrative approach to develop and propose a framework for the evaluation of priority setting practices at the macro and meso levels that draws from these complementary schools of thought. © 2015

  2. Setting Healthcare Priorities at the Macro and Meso Levels: A Framework for Evaluation

    Science.gov (United States)

    Barasa, Edwine W.; Molyneux, Sassy; English, Mike; Cleary, Susan

    2015-01-01

    Background: Priority setting in healthcare is a key determinant of health system performance. However, there is no widely accepted priority setting evaluation framework. We reviewed literature with the aim of developing and proposing a framework for the evaluation of macro and meso level healthcare priority setting practices. Methods: We systematically searched Econlit, PubMed, CINAHL, and EBSCOhost databases and supplemented this with searches in Google Scholar, relevant websites and reference lists of relevant papers. A total of 31 papers on evaluation of priority setting were identified. These were supplemented by broader theoretical literature related to evaluation of priority setting. A conceptual review of selected papers was undertaken. Results: Based on a synthesis of the selected literature, we propose an evaluative framework that requires that priority setting practices at the macro and meso levels of the health system meet the following conditions: (1) Priority setting decisions should incorporate both efficiency and equity considerations as well as the following outcomes; (a) Stakeholder satisfaction, (b) Stakeholder understanding, (c) Shifted priorities (reallocation of resources), and (d) Implementation of decisions. (2) Priority setting processes should also meet the procedural conditions of (a) Stakeholder engagement, (b) Stakeholder empowerment, (c) Transparency, (d) Use of evidence, (e) Revisions, (f) Enforcement, and (g) Being grounded on community values. Conclusion: Available frameworks for the evaluation of priority setting are mostly grounded on procedural requirements, while few have included outcome requirements. There is, however, increasing recognition of the need to incorporate both consequential and procedural considerations in priority setting practices. In this review, we adapt an integrative approach to develop and propose a framework for the evaluation of priority setting practices at the macro and meso levels that draws from these

  3. Setting Healthcare Priorities at the Macro and Meso Levels: A Framework for Evaluation

    Directory of Open Access Journals (Sweden)

    Edwine W. Barasa

    2015-11-01

    Full Text Available Background Priority setting in healthcare is a key determinant of health system performance. However, there is no widely accepted priority setting evaluation framework. We reviewed literature with the aim of developing and proposing a framework for the evaluation of macro and meso level healthcare priority setting practices. Methods We systematically searched Econlit, PubMed, CINAHL, and EBSCOhost databases and supplemented this with searches in Google Scholar, relevant websites and reference lists of relevant papers. A total of 31 papers on evaluation of priority setting were identified. These were supplemented by broader theoretical literature related to evaluation of priority setting. A conceptual review of selected papers was undertaken. Results Based on a synthesis of the selected literature, we propose an evaluative framework that requires that priority setting practices at the macro and meso levels of the health system meet the following conditions: (1 Priority setting decisions should incorporate both efficiency and equity considerations as well as the following outcomes; (a Stakeholder satisfaction, (b Stakeholder understanding, (c Shifted priorities (reallocation of resources, and (d Implementation of decisions. (2 Priority setting processes should also meet the procedural conditions of (a Stakeholder engagement, (b Stakeholder empowerment, (c Transparency, (d Use of evidence, (e Revisions, (f Enforcement, and (g Being grounded on community values. Conclusion Available frameworks for the evaluation of priority setting are mostly grounded on procedural requirements, while few have included outcome requirements. There is, however, increasing recognition of the need to incorporate both consequential and procedural considerations in priority setting practices. In this review, we adapt an integrative approach to develop and propose a framework for the evaluation of priority setting practices at the macro and meso levels that draws from

  4. New and improved data products from the Permanent Service for Mean Sea Level (PSMSL)

    Science.gov (United States)

    Matthews, Andrew; Bradshaw, Elizabeth; Gordon, Kathy; Hibbert, Angela; Jevrejeva, Svetlana; Rickards, Lesley; Tamisiea, Mark; Williams, Simon

    2015-04-01

    The Permanent Service for Mean Sea Level (PSMSL) is the internationally recognised global sea level data bank for long term sea level change information from tide gauges. Established in 1933, the PSMSL continues to be responsible for the collection, publication, analysis and interpretation of sea level data. The PSMSL operates under the auspices of the International Council for Science (ICSU) and is one of the main data centres for both the International Association for the Physical Sciences of the Oceans (IAPSO) and the International Association of Geodesy (IAG). The PSMSL continues to work closely with other members of the sea level community through the Intergovernmental Oceanographic Commission's Global Sea Level Observing System (GLOSS). Currently, the PSMSL data bank for monthly and annual sea level data holds over 65,000 station-years of data from over 2200 stations. Data from each site are carefully quality controlled and, wherever possible, reduced to a common datum, whose stability is monitored through a network of geodetic benchmarks. Last year, the PSMSL also made available a data bank of measurements taken from in-situ ocean bottom pressure recorders from over 60 locations across the globe. Here, we present an overview of the data available at the PSMSL, and describe some of the ongoing work that aims to provide more information to users of our data. In particular, we describe the ongoing work with the Système d'Observation du Niveau des Eaux Littorales (SONEL) to use measurements from continuous GNSS records located near tide gauges to provide PSMSL data within a geocentric reference frame. We also highlight changes to the method used to present estimated sea level trends to account for seasonal cycles and autocorrelation in the data, and provide an estimate of the error of the trend.

  5. Improvement of Global and Regional Mean Sea Level Trends Derived from all Altimetry Missions.

    Science.gov (United States)

    Ablain, Michael; Benveniste, Jérôme; Faugere, Yannice; Larnicol, Gilles; Cazenave, Anny; Johannessen, Johnny A.; Stammer, Detlef; Timms, Gary

    2012-07-01

    The global mean sea level (GMSL) has been calculated on a continual basis since January 1993 using data from satellite altimetry missions. The global mean sea level (MSL) deduced from TOPEX/Poseidon, Jason-1 and Jason-2 is increasing with a global trend of 3.2 mm from 1993 to 2010 applying the post glacial rebound (MSL Aviso website http://www.jason.oceanobs.com/msl). Besides, the regional sea level trends bring out an inhomogeneous repartition of the ocean elevation with local MSL slopes ranging from +/- 8 mm/year. A study published in 2009 [Ablain et al., 2009] has shown that the global MSL trend uncertainty was estimated at +/-0.6 mm/year with a confidence interval of 90%. The main sources of errors at global and regional scales are due to the orbit calculation and the wet troposphere correction. But others sea-level components have also a significant impact on the long-term stability of MSL as for instance the stability of instrumental parameters and the atmospheric corrections. Thanks to recent studies performed in Sea Level Essential Climate Variable Project in the frame of the Climate Change Initiative, an ESA Programme, in addition to activities performed within the SALP/CNES, strong improvements have been provided for the estimation of the global and regional MSL trends. In this paper, we propose to describe them; they concern the orbit calculation thanks to new gravity fields, the atmospheric corrections thanks to ERA-interim reanalyses, the wet troposphere corrections thanks to the stability improvement, and also empirical corrections allowing us to link regional time series together better. These improvements are described at global and regional scale for all the altimetry missions.

  6. The predictive value of mean serum uric acid levels for developing prediabetes.

    Science.gov (United States)

    Zhang, Qing; Bao, Xue; Meng, Ge; Liu, Li; Wu, Hongmei; Du, Huanmin; Shi, Hongbin; Xia, Yang; Guo, Xiaoyan; Liu, Xing; Li, Chunlei; Su, Qian; Gu, Yeqing; Fang, Liyun; Yu, Fei; Yang, Huijun; Yu, Bin; Sun, Shaomei; Wang, Xing; Zhou, Ming; Jia, Qiyu; Zhao, Honglin; Huang, Guowei; Song, Kun; Niu, Kaijun

    2016-08-01

    We aimed to assess the predictive value of mean serum uric acid (SUA) levels for incident prediabetes. Normoglycemic adults (n=39,353) were followed for a median of 3.0years. Prediabetes is defined as impaired fasting glucose (IFG), impaired glucose tolerance (IGT), or impaired HbA1c (IA1c), based on the American Diabetes Association criteria. Serum SUA levels were measured annually. Four diagnostic strategies were used to detect prediabetes in four separate analyses (Analysis 1: IFG. Analysis 2: IFG+IGT. Analysis 3: IFG+IA1c. Analysis 4: IFG+IGT+IA1c). Cox proportional hazards regression models were used to assess the relationship between SUA quintiles and prediabetes. C-statistic was additionally used in the final analysis to assess the accuracy of predictions based upon baseline SUA and mean SUA, respectively. After adjustment for potential confounders, the hazard ratios (95% confidence interval) of prediabetes for the highest versus lowest quintile of mean SUA were 1.22 (1.10, 1.36) in analysis 1; 1.59 (1.23, 2.05) in analysis 2; 1.62 (1.34, 1.95) in analysis 3 and 1.67 (1.31, 2.13) in analysis 4. In contrast, for baseline SUA, significance was only reached in analyses 3 and 4. Moreover, compared with baseline SUA, mean SUA value was associated with a significant increase in the C-statistic (Pprediabetes risk, and showed better predictive ability for prediabetes than baseline SUA. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

  7. 76 FR 9004 - Public Comment on Setting Achievement Levels in Writing

    Science.gov (United States)

    2011-02-16

    ... DEPARTMENT OF EDUCATION Public Comment on Setting Achievement Levels in Writing AGENCY: U.S... Achievement Levels in Writing. SUMMARY: The National Assessment Governing Board (Governing Board) is... for NAEP in writing. This notice provides opportunity for public comment and submitting...

  8. Application of physiologically based pharmacokinetic modeling in setting acute exposure guideline levels for methylene chloride.

    NARCIS (Netherlands)

    Bos, Peter Martinus Jozef; Zeilmaker, Marco Jacob; Eijkeren, Jan Cornelis Henri van

    2006-01-01

    Acute exposure guideline levels (AEGLs) are derived to protect the human population from adverse health effects in case of single exposure due to an accidental release of chemicals into the atmosphere. AEGLs are set at three different levels of increasing toxicity for exposure durations ranging from

  9. Improvement of global and regional mean sea level derived from satellite altimetry multi missions

    Science.gov (United States)

    Ablain, M.; Faugere, Y.; Larnicol, G.; Picot, N.; Cazenave, A.; Benveniste, J.

    2012-04-01

    With the satellite altimetry missions, the global mean sea level (GMSL) has been calculated on a continual basis since January 1993. 'Verification' phases, during which the satellites follow each other in close succession (Topex/Poseidon--Jason-1, then Jason-1--Jason-2), help to link up these different missions by precisely determining any bias between them. Envisat, ERS-1 and ERS-2 are also used, after being adjusted on these reference missions, in order to compute Mean Sea Level at high latitudes (higher than 66°N and S), and also to improve spatial resolution by combining all these missions together. The global mean sea level (MSL) deduced from TOPEX/Poseidon, Jason-1 and Jason-2 provide a global rate of 3.2 mm from 1993 to 2010 applying the post glacial rebound (MSL aviso website http://www.jason.oceanobs.com/msl). Besides, the regional sea level trends bring out an inhomogeneous repartition of the ocean elevation with local MSL slopes ranging from + 8 mm/yr to - 8 mm/year. A study published in 2009 [Ablain et al., 2009] has shown that the global MSL trend unceratainty was estimated at +/-0.6 mm/year with a confidence interval of 90%. The main sources of errors at global and regional scales are due to the orbit calculation and the wet troposphere correction. But others sea-level components have also a significant impact on the long-term stability of MSL as for instance the stability of instrumental parameters and the atmospheric corrections. Thanks to recent studies performed in the frame of the SALP project (supported by CNES) and Sea-level Climate Change Initiative project (supported by ESA), strong improvements have been provided for the estimation of the global and regional MSL trends. In this paper, we propose to describe them; they concern the orbit calculation thanks to new gravity fields, the atmospheric corrections thanks to ERA-interim reanalyses, the wet troposphere corrections thanks to the stability improvement, and also empirical corrections

  10. Long-term management of high-level radioactive waste. The meaning of a demonstration

    International Nuclear Information System (INIS)

    1983-01-01

    The ''demonstration'' of the safe management of high level radioactive waste is a prerequisite for the further development of nuclear energy. It is therefore essential to be clear about both the meaning of the term ''demonstration'' and the practical means to satisfy this request. In the complex sequence of operations necessary to the safe management of high level waste, short term activities can be directly demonstrated. For longer term activities, such as the long term isolation of radioactive waste in deep undergroung structures, demonstration must be indirect. The ''demonstration'' of deep underground disposal for high level radioactive waste involves two steps: one direct, to prove that the system could be built, operated and closed safely and at acceptable costs, and one indirect, to make a convincing evaluation of the system's performance and long term safety on the basis of predictive analyses confirmed by a body of varied technical and scienfic data, much of it deriving from experimental work. The assessment of the evidence collected from current operations, existing experience in related fields and specific research and development activities, calls for specialized scientific expertise. Uncertainties in far future situations and probabilistic events can be taken into account in a scientific assessment. Competent national authorithies will have to satisfy themselves that the proposed waste management solutions can meet long term safety objectives. An element of judgement will always be needed in determining the acceptability of a waste disposal concept. However, the level of confidence in our ability to predict the performance of waste management systems will increase as supporting evidence is collected from current research and development activities and as our predictive techniques improve

  11. Fluoroscopy-guided insertion of nasojejunal tubes in children - setting local diagnostic reference levels

    International Nuclear Information System (INIS)

    Vitta, Lavanya; Raghavan, Ashok; Sprigg, Alan; Morrell, Rachel

    2009-01-01

    Little is known about the radiation burden from fluoroscopy-guided insertions of nasojejunal tubes (NJTs) in children. There are no recommended or published standards of diagnostic reference levels (DRLs) available. To establish reference dose area product (DAP) levels for the fluoroscopy-guided insertion of nasojejunal tubes as a basis for setting DRLs for children. In addition, we wanted to assess our local practice and determine the success and complication rates associated with this procedure. Children who had NJT insertion procedures were identified retrospectively from the fluoroscopy database. The age of the child at the time of the procedure, DAP, screening time, outcome of the procedure, and any complications were recorded for each procedure. As the radiation dose depends on the size of the child, the children were assigned to three different age groups. The sample size, mean, median and third-quartile DAPs were calculated for each group. The third-quartile values were used to establish the DRLs. Of 186 procedures performed, 172 were successful on the first attempt. These were performed in a total of 43 children with 60% having multiple insertions over time. The third-quartile DAPs were as follows for each age group: 0-12 months, 2.6 cGy cm 2 ; 1-7 years, 2.45 cGy cm 2 ; >8 years, 14.6 cGy cm 2 . High DAP readings were obtained in the 0-12 months (n = 4) and >8 years (n = 2) age groups. No immediate complications were recorded. Fluoroscopy-guided insertion of NJTs is a highly successful procedure in a selected population of children and is associated with a low complication rate. The radiation dose per procedure is relatively low. (orig.)

  12. Variational Level Set Method for Two-Stage Image Segmentation Based on Morphological Gradients

    Directory of Open Access Journals (Sweden)

    Zemin Ren

    2014-01-01

    Full Text Available We use variational level set method and transition region extraction techniques to achieve image segmentation task. The proposed scheme is done by two steps. We first develop a novel algorithm to extract transition region based on the morphological gradient. After this, we integrate the transition region into a variational level set framework and develop a novel geometric active contour model, which include an external energy based on transition region and fractional order edge indicator function. The external energy is used to drive the zero level set toward the desired image features, such as object boundaries. Due to this external energy, the proposed model allows for more flexible initialization. The fractional order edge indicator function is incorporated into the length regularization term to diminish the influence of noise. Moreover, internal energy is added into the proposed model to penalize the deviation of the level set function from a signed distance function. The results evolution of the level set function is the gradient flow that minimizes the overall energy functional. The proposed model has been applied to both synthetic and real images with promising results.

  13. Appropriate criteria set for personnel promotion across organizational levels using analytic hierarchy process (AHP

    Directory of Open Access Journals (Sweden)

    Charles Noven Castillo

    2017-01-01

    Full Text Available Currently, there has been limited established specific set of criteria for personnel promotion to each level of the organization. This study is conducted in order to develop a personnel promotion strategy by identifying specific sets of criteria for each level of the organization. The complexity of identifying the criteria set along with the subjectivity of these criteria require the use of multi-criteria decision-making approach particularly the analytic hierarchy process (AHP. Results show different sets of criteria for each management level which are consistent with several frameworks in literature. These criteria sets would help avoid mismatch of employee skills and competencies and their job, and at the same time eliminate the issues in personnel promotion such as favouritism, glass ceiling, and gender and physical attractiveness preference. This work also shows that personality and traits, job satisfaction and experience and skills are more critical rather than social capital across different organizational levels. The contribution of this work is in identifying relevant criteria in developing a personnel promotion strategy across organizational levels.

  14. Social meanings and understandings in patient-nurse interaction in the community practice setting: a grounded theory study

    Directory of Open Access Journals (Sweden)

    Stoddart Kathleen M

    2012-09-01

    Full Text Available Abstract Background The patient-nurse relationship is a traditional concern of healthcare research. However, patient-nurse interaction is under examined from a social perspective. Current research focuses mostly on specific contexts of care delivery and experience related to medical condition or illness, or to nurses’ speciality. Consequentially, this paper is about the social meanings and understandings at play within situated patient-nurse interaction in the community practice setting in a transforming healthcare service. Methods Grounded theory methodology was used and the research process was characterised by principles of theoretical sensitivity and constant comparative analysis. The field of study was four health centres in the community. The participants were patients and nurses representative of those attending or working in the health centres and meeting there by scheduled appointment. Data collection methods were observations, informal interviews and semi-structured interviews. Results Key properties of ‘Being a good patient, being a good nurse’, ‘Institutional experiences’ and ‘Expectations about healthcare’ were associated with the construction of a category entitled ‘Experience’. Those key properties captured that in an evolving healthcare environment individuals continually re-constructed their reality of being a patient or nurse as they endeavoured to perform appropriately; articulation of past and present healthcare experiences was important in that process. Modus operandi in role as patient was influenced by past experiences in healthcare and by those in non-healthcare institutions in terms of engagement and involvement (or not in interaction. Patients’ expectations about interaction in healthcare included some uncertainly as they strived to make sense of the changing roles and expertise of nurses and, differentiating between the roles and expertise of nurses and doctors. Conclusions The importance of social

  15. Joint inversion of geophysical data using petrophysical clustering and facies deformation wth the level set technique

    Science.gov (United States)

    Revil, A.

    2015-12-01

    Geological expertise and petrophysical relationships can be brought together to provide prior information while inverting multiple geophysical datasets. The merging of such information can result in more realistic solution in the distribution of the model parameters, reducing ipse facto the non-uniqueness of the inverse problem. We consider two level of heterogeneities: facies, described by facies boundaries and heteroegenities inside each facies determined by a correlogram. In this presentation, we pose the geophysical inverse problem in terms of Gaussian random fields with mean functions controlled by petrophysical relationships and covariance functions controlled by a prior geological cross-section, including the definition of spatial boundaries for the geological facies. The petrophysical relationship problem is formulated as a regression problem upon each facies. The inversion of the geophysical data is performed in a Bayesian framework. We demonstrate the usefulness of this strategy using a first synthetic case for which we perform a joint inversion of gravity and galvanometric resistivity data with the stations located at the ground surface. The joint inversion is used to recover the density and resistivity distributions of the subsurface. In a second step, we consider the possibility that the facies boundaries are deformable and their shapes are inverted as well. We use the level set approach to perform such deformation preserving prior topological properties of the facies throughout the inversion. With the help of prior facies petrophysical relationships and topological characteristic of each facies, we make posterior inference about multiple geophysical tomograms based on their corresponding geophysical data misfits. The method is applied to a second synthetic case showing that we can recover the heterogeneities inside the facies, the mean values for the petrophysical properties, and, to some extent, the facies boundaries using the 2D joint inversion of

  16. Priority setting at the micro-, meso- and macro-levels in Canada, Norway and Uganda.

    Science.gov (United States)

    Kapiriri, Lydia; Norheim, Ole Frithjof; Martin, Douglas K

    2007-06-01

    The objectives of this study were (1) to describe the process of healthcare priority setting in Ontario-Canada, Norway and Uganda at the three levels of decision-making; (2) to evaluate the description using the framework for fair priority setting, accountability for reasonableness; so as to identify lessons of good practices. We carried out case studies involving key informant interviews, with 184 health practitioners and health planners from the macro-level, meso-level and micro-level from Canada-Ontario, Norway and Uganda (selected by virtue of their varying experiences in priority setting). Interviews were audio-recorded, transcribed and analyzed using a modified thematic approach. The descriptions were evaluated against the four conditions of "accountability for reasonableness", relevance, publicity, revisions and enforcement. Areas of adherence to these conditions were identified as lessons of good practices; areas of non-adherence were identified as opportunities for improvement. (i) at the macro-level, in all three countries, cabinet makes most of the macro-level resource allocation decisions and they are influenced by politics, public pressure, and advocacy. Decisions within the ministries of health are based on objective formulae and evidence. International priorities influenced decisions in Uganda. Some priority-setting reasons are publicized through circulars, printed documents and the Internet in Canada and Norway. At the meso-level, hospital priority-setting decisions were made by the hospital managers and were based on national priorities, guidelines, and evidence. Hospital departments that handle emergencies, such as surgery, were prioritized. Some of the reasons are available on the hospital intranet or presented at meetings. Micro-level practitioners considered medical and social worth criteria. These reasons are not publicized. Many practitioners lacked knowledge of the macro- and meso-level priority-setting processes. (ii) Evaluation

  17. Reconstruction of thin electromagnetic inclusions by a level-set method

    International Nuclear Information System (INIS)

    Park, Won-Kwang; Lesselier, Dominique

    2009-01-01

    In this contribution, we consider a technique of electromagnetic imaging (at a single, non-zero frequency) which uses the level-set evolution method for reconstructing a thin inclusion (possibly made of disconnected parts) with either dielectric or magnetic contrast with respect to the embedding homogeneous medium. Emphasis is on the proof of the concept, the scattering problem at hand being so far based on a two-dimensional scalar model. To do so, two level-set functions are employed; the first one describes location and shape, and the other one describes connectivity and length. Speeds of evolution of the level-set functions are calculated via the introduction of Fréchet derivatives of a least-square cost functional. Several numerical experiments on noiseless and noisy data as well illustrate how the proposed method behaves

  18. Aerostructural Level Set Topology Optimization for a Common Research Model Wing

    Science.gov (United States)

    Dunning, Peter D.; Stanford, Bret K.; Kim, H. Alicia

    2014-01-01

    The purpose of this work is to use level set topology optimization to improve the design of a representative wing box structure for the NASA common research model. The objective is to minimize the total compliance of the structure under aerodynamic and body force loading, where the aerodynamic loading is coupled to the structural deformation. A taxi bump case was also considered, where only body force loads were applied. The trim condition that aerodynamic lift must balance the total weight of the aircraft is enforced by allowing the root angle of attack to change. The level set optimization method is implemented on an unstructured three-dimensional grid, so that the method can optimize a wing box with arbitrary geometry. Fast matching and upwind schemes are developed for an unstructured grid, which make the level set method robust and efficient. The adjoint method is used to obtain the coupled shape sensitivities required to perform aerostructural optimization of the wing box structure.

  19. Multi person detection and tracking based on hierarchical level-set method

    Science.gov (United States)

    Khraief, Chadia; Benzarti, Faouzi; Amiri, Hamid

    2018-04-01

    In this paper, we propose an efficient unsupervised method for mutli-person tracking based on hierarchical level-set approach. The proposed method uses both edge and region information in order to effectively detect objects. The persons are tracked on each frame of the sequence by minimizing an energy functional that combines color, texture and shape information. These features are enrolled in covariance matrix as region descriptor. The present method is fully automated without the need to manually specify the initial contour of Level-set. It is based on combined person detection and background subtraction methods. The edge-based is employed to maintain a stable evolution, guide the segmentation towards apparent boundaries and inhibit regions fusion. The computational cost of level-set is reduced by using narrow band technique. Many experimental results are performed on challenging video sequences and show the effectiveness of the proposed method.

  20. Level set methods for detonation shock dynamics using high-order finite elements

    Energy Technology Data Exchange (ETDEWEB)

    Dobrev, V. A. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Grogan, F. C. [Univ. of California, San Diego, CA (United States); Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Kolev, T. V. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Rieben, R [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Tomov, V. Z. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

    2017-05-26

    Level set methods are a popular approach to modeling evolving interfaces. We present a level set ad- vection solver in two and three dimensions using the discontinuous Galerkin method with high-order nite elements. During evolution, the level set function is reinitialized to a signed distance function to maintain ac- curacy. Our approach leads to stable front propagation and convergence on high-order, curved, unstructured meshes. The ability of the solver to implicitly track moving fronts lends itself to a number of applications; in particular, we highlight applications to high-explosive (HE) burn and detonation shock dynamics (DSD). We provide results for two- and three-dimensional benchmark problems as well as applications to DSD.

  1. A parametric level-set approach for topology optimization of flow domains

    DEFF Research Database (Denmark)

    Pingen, Georg; Waidmann, Matthias; Evgrafov, Anton

    2010-01-01

    of the design variables in the traditional approaches is seen as a possible cause for the slow convergence. Non-smooth material distributions are suspected to trigger premature onset of instationary flows which cannot be treated by steady-state flow models. In the present work, we study whether the convergence...... and the versatility of topology optimization methods for fluidic systems can be improved by employing a parametric level-set description. In general, level-set methods allow controlling the smoothness of boundaries, yield a non-local influence of design variables, and decouple the material description from the flow...... field discretization. The parametric level-set method used in this study utilizes a material distribution approach to represent flow boundaries, resulting in a non-trivial mapping between design variables and local material properties. Using a hydrodynamic lattice Boltzmann method, we study...

  2. Risk assessment of water pollution sources based on an integrated k-means clustering and set pair analysis method in the region of Shiyan, China.

    Science.gov (United States)

    Li, Chunhui; Sun, Lian; Jia, Junxiang; Cai, Yanpeng; Wang, Xuan

    2016-07-01

    Source water areas are facing many potential water pollution risks. Risk assessment is an effective method to evaluate such risks. In this paper an integrated model based on k-means clustering analysis and set pair analysis was established aiming at evaluating the risks associated with water pollution in source water areas, in which the weights of indicators were determined through the entropy weight method. Then the proposed model was applied to assess water pollution risks in the region of Shiyan in which China's key source water area Danjiangkou Reservoir for the water source of the middle route of South-to-North Water Diversion Project is located. The results showed that eleven sources with relative high risk value were identified. At the regional scale, Shiyan City and Danjiangkou City would have a high risk value in term of the industrial discharge. Comparatively, Danjiangkou City and Yunxian County would have a high risk value in terms of agricultural pollution. Overall, the risk values of north regions close to the main stream and reservoir of the region of Shiyan were higher than that in the south. The results of risk level indicated that five sources were in lower risk level (i.e., level II), two in moderate risk level (i.e., level III), one in higher risk level (i.e., level IV) and three in highest risk level (i.e., level V). Also risks of industrial discharge are higher than that of the agricultural sector. It is thus essential to manage the pillar industry of the region of Shiyan and certain agricultural companies in the vicinity of the reservoir to reduce water pollution risks of source water areas. Copyright © 2016 Elsevier B.V. All rights reserved.

  3. Setting-level influences on implementation of the responsive classroom approach.

    Science.gov (United States)

    Wanless, Shannon B; Patton, Christine L; Rimm-Kaufman, Sara E; Deutsch, Nancy L

    2013-02-01

    We used mixed methods to examine the association between setting-level factors and observed implementation of a social and emotional learning intervention (Responsive Classroom® approach; RC). In study 1 (N = 33 3rd grade teachers after the first year of RC implementation), we identified relevant setting-level factors and uncovered the mechanisms through which they related to implementation. In study 2 (N = 50 4th grade teachers after the second year of RC implementation), we validated our most salient Study 1 finding across multiple informants. Findings suggested that teachers perceived setting-level factors, particularly principal buy-in to the intervention and individualized coaching, as influential to their degree of implementation. Further, we found that intervention coaches' perspectives of principal buy-in were more related to implementation than principals' or teachers' perspectives. Findings extend the application of setting theory to the field of implementation science and suggest that interventionists may want to consider particular accounts of school setting factors before determining the likelihood of schools achieving high levels of implementation.

  4. Robust boundary detection of left ventricles on ultrasound images using ASM-level set method.

    Science.gov (United States)

    Zhang, Yaonan; Gao, Yuan; Li, Hong; Teng, Yueyang; Kang, Yan

    2015-01-01

    Level set method has been widely used in medical image analysis, but it has difficulties when being used in the segmentation of left ventricular (LV) boundaries on echocardiography images because the boundaries are not very distinguish, and the signal-to-noise ratio of echocardiography images is not very high. In this paper, we introduce the Active Shape Model (ASM) into the traditional level set method to enforce shape constraints. It improves the accuracy of boundary detection and makes the evolution more efficient. The experiments conducted on the real cardiac ultrasound image sequences show a positive and promising result.

  5. Correlation of symptom depression levels with mean platelet volume rate on patients of acute coronary syndrome

    Science.gov (United States)

    Hasugian, L.; Hanum, H.; Hanida, W.; Safri, Z.

    2018-03-01

    Patients with Depression and the acute coronary syndrome (ACS) is rarely detected, although in some studies say that depression can worsen cardiovascularly and increase mortality. From research, Canan F et al found that increasing levels of Mean platelet volume (MPV) as a risk factor for atherosclerosis and MPV was higher in patients with depression compared with patients without depression. In this study used observational methods of measurement of cross-sectional data. Research began in November 2015 - May 2016 against General Hospital inpatients H. Adam Malik Medan. There are 64 patients with a diagnosis of ACS were given quieter Beck Depression Inventory (BDI), then calculated a score of BDI patients and MPV levels were seen when they first entered the hospital before being given treatment. Patients answered quieter on days 3-7 after diagnosis ACS. ACS Patients were divided into 3 groups: acute myocardial infarction with ST elevation, acute myocardial infarction with non-ST elevation and unstable angina pectoris. The level of depression is grouped into not depression, mild depression, moderate depression and severe depression. Statistically significant with p-value<0.05Based on the linear correlation analysis, it was found a positive correlation with r=0.542. And the relationship is statistically significant with p-value 0.000003.

  6. Individual-and Setting-Level Correlates of Secondary Traumatic Stress in Rape Crisis Center Staff.

    Science.gov (United States)

    Dworkin, Emily R; Sorell, Nicole R; Allen, Nicole E

    2016-02-01

    Secondary traumatic stress (STS) is an issue of significant concern among providers who work with survivors of sexual assault. Although STS has been studied in relation to individual-level characteristics of a variety of types of trauma responders, less research has focused specifically on rape crisis centers as environments that might convey risk or protection from STS, and no research to knowledge has modeled setting-level variation in correlates of STS. The current study uses a sample of 164 staff members representing 40 rape crisis centers across a single Midwestern state to investigate the staff member-and agency-level correlates of STS. Results suggest that correlates exist at both levels of analysis. Younger age and greater severity of sexual assault history were statistically significant individual-level predictors of increased STS. Greater frequency of supervision was more strongly related to secondary stress for non-advocates than for advocates. At the setting level, lower levels of supervision and higher client loads agency-wide accounted for unique variance in staff members' STS. These findings suggest that characteristics of both providers and their settings are important to consider when understanding their STS. © The Author(s) 2014.

  7. [Noninvasive detection of hematocrit and the mean corpuscular hemoglobin concentration levels by Vis-NIR spectroscopy].

    Science.gov (United States)

    Zhao, Jing; Lin, Ling; Lu, Xiao-Zuo; Li, Gang

    2014-03-01

    Hematocrit (HCT) and mean hemoglobin concentration(MCHC) play a very important role in preventing cardiovascular disease and anemia. A method was developed on the basis of spectroscopy to detect HCT and MCHC non-invasively and accurately. The anatomical study showed that the blood rheology abnormalities and blood viscosity's changes can cause the changes of tongue, so there is a certain correlation between tongue and blood components. Reflectance spectrums from the tongue tips of 240 volunteers were collected, then the tongue pictures were captured and the biochemical analysis results were recorded at the same time. The 240 samples were separated into two parts: calibration sample and test sample. Spectra were then subjected to a partial least squares regression (PLSR) analysis to develop mathematics models for predicting HCT levels. The correlation between the data and prediction of HCT and MCHC yielded calibration samples value of 0.998 and 0.938. HCT and MCHC levels of test samples predicted by this model from Visible-Near infrared spectra provided a coefficient of determination in prediction of 0.979 and 0.883 with an average relative error of prediction of 1.65% and 1.88%, a root mean square error of prediction of 4.066 and 4.139. From the experiment results we can see that the model which was built before can better predict the HCT and MCHC, and the results also showed that spectrometry method may provide a promising approach to the noninvasive measurement of human HCT and MCHC with a combination of PLSR analysis.

  8. Demons versus level-set motion registration for coronary 18F-sodium fluoride PET

    Science.gov (United States)

    Rubeaux, Mathieu; Joshi, Nikhil; Dweck, Marc R.; Fletcher, Alison; Motwani, Manish; Thomson, Louise E.; Germano, Guido; Dey, Damini; Berman, Daniel S.; Newby, David E.; Slomka, Piotr J.

    2016-03-01

    Ruptured coronary atherosclerotic plaques commonly cause acute myocardial infarction. It has been recently shown that active microcalcification in the coronary arteries, one of the features that characterizes vulnerable plaques at risk of rupture, can be imaged using cardiac gated 18F-sodium fluoride (18F-NaF) PET. We have shown in previous work that a motion correction technique applied to cardiac-gated 18F-NaF PET images can enhance image quality and improve uptake estimates. In this study, we further investigated the applicability of different algorithms for registration of the coronary artery PET images. In particular, we aimed to compare demons vs. level-set nonlinear registration techniques applied for the correction of cardiac motion in coronary 18F-NaF PET. To this end, fifteen patients underwent 18F-NaF PET and prospective coronary CT angiography (CCTA). PET data were reconstructed in 10 ECG gated bins; subsequently these gated bins were registered using demons and level-set methods guided by the extracted coronary arteries from CCTA, to eliminate the effect of cardiac motion on PET images. Noise levels, target-to-background ratios (TBR) and global motion were compared to assess image quality. Compared to the reference standard of using only diastolic PET image (25% of the counts from PET acquisition), cardiac motion registration using either level-set or demons techniques almost halved image noise due to the use of counts from the full PET acquisition and increased TBR difference between 18F-NaF positive and negative lesions. The demons method produces smoother deformation fields, exhibiting no singularities (which reflects how physically plausible the registration deformation is), as compared to the level-set method, which presents between 4 and 8% of singularities, depending on the coronary artery considered. In conclusion, the demons method produces smoother motion fields as compared to the level-set method, with a motion that is physiologically

  9. Means and extremes: building variability into community-level climate change experiments.

    Science.gov (United States)

    Thompson, Ross M; Beardall, John; Beringer, Jason; Grace, Mike; Sardina, Paula

    2013-06-01

    Experimental studies assessing climatic effects on ecological communities have typically applied static warming treatments. Although these studies have been informative, they have usually failed to incorporate either current or predicted future, patterns of variability. Future climates are likely to include extreme events which have greater impacts on ecological systems than changes in means alone. Here, we review the studies which have used experiments to assess impacts of temperature on marine, freshwater and terrestrial communities, and classify them into a set of 'generations' based on how they incorporate variability. The majority of studies have failed to incorporate extreme events. In terrestrial ecosystems in particular, experimental treatments have reduced temperature variability, when most climate models predict increased variability. Marine studies have tended to not concentrate on changes in variability, likely in part because the thermal mass of oceans will moderate variation. In freshwaters, climate change experiments have a much shorter history than in the other ecosystems, and have tended to take a relatively simple approach. We propose a new 'generation' of climate change experiments using down-scaled climate models which incorporate predicted changes in climatic variability, and describe a process for generating data which can be applied as experimental climate change treatments. © 2013 John Wiley & Sons Ltd/CNRS.

  10. MO-AB-BRA-01: A Global Level Set Based Formulation for Volumetric Modulated Arc Therapy

    Energy Technology Data Exchange (ETDEWEB)

    Nguyen, D; Lyu, Q; Ruan, D; O’Connor, D; Low, D; Sheng, K [Department of Radiation Oncology, University of California Los Angeles, Los Angeles, CA (United States)

    2016-06-15

    Purpose: The current clinical Volumetric Modulated Arc Therapy (VMAT) optimization is formulated as a non-convex problem and various greedy heuristics have been employed for an empirical solution, jeopardizing plan consistency and quality. We introduce a novel global direct aperture optimization method for VMAT to overcome these limitations. Methods: The global VMAT (gVMAT) planning was formulated as an optimization problem with an L2-norm fidelity term and an anisotropic total variation term. A level set function was used to describe the aperture shapes and adjacent aperture shapes were penalized to control MLC motion range. An alternating optimization strategy was implemented to solve the fluence intensity and aperture shapes simultaneously. Single arc gVMAT plans, utilizing 180 beams with 2° angular resolution, were generated for a glioblastoma multiforme (GBM), lung (LNG), and 2 head and neck cases—one with 3 PTVs (H&N3PTV) and one with 4 PTVs (H&N4PTV). The plans were compared against the clinical VMAT (cVMAT) plans utilizing two overlapping coplanar arcs. Results: The optimization of the gVMAT plans had converged within 600 iterations. gVMAT reduced the average max and mean OAR dose by 6.59% and 7.45% of the prescription dose. Reductions in max dose and mean dose were as high as 14.5 Gy in the LNG case and 15.3 Gy in the H&N3PTV case. PTV coverages (D95, D98, D99) were within 0.25% of the prescription dose. By globally considering all beams, the gVMAT optimizer allowed some beams to deliver higher intensities, yielding a dose distribution that resembles a static beam IMRT plan with beam orientation optimization. Conclusions: The novel VMAT approach allows for the search of an optimal plan in the global solution space and generates deliverable apertures directly. The single arc VMAT approach fully utilizes the digital linacs’ capability in dose rate and gantry rotation speed modulation. Varian Medical Systems, NIH grant R01CA188300, NIH grant R43CA183390.

  11. Analysis of Forensic Autopsy in 120 Cases of Medical Disputes Among Different Levels of Institutional Settings.

    Science.gov (United States)

    Yu, Lin-Sheng; Ye, Guang-Hua; Fan, Yan-Yan; Li, Xing-Biao; Feng, Xiang-Ping; Han, Jun-Ge; Lin, Ke-Zhi; Deng, Miao-Wu; Li, Feng

    2015-09-01

    Despite advances in medical science, the causes of death can sometimes only be determined by pathologists after a complete autopsy. Few studies have investigated the importance of forensic autopsy in medically disputed cases among different levels of institutional settings. Our study aimed to analyze forensic autopsy in 120 cases of medical disputes among five levels of institutional settings between 2001 and 2012 in Wenzhou, China. The results showed an overall concordance rate of 55%. Of the 39% of clinically missed diagnosis, cardiovascular pathology comprises 55.32%, while respiratory pathology accounts for the remaining 44. 68%. Factors that increase the likelihood of missed diagnoses were private clinics, community settings, and county hospitals. These results support that autopsy remains an important tool in establishing causes of death in medically disputed case, which may directly determine or exclude the fault of medical care and therefore in helping in resolving these cases. © 2015 American Academy of Forensic Sciences.

  12. An investigation of children's levels of inquiry in an informal science setting

    Science.gov (United States)

    Clark-Thomas, Beth Anne

    Elementary school students' understanding of both science content and processes are enhanced by the higher level thinking associated with inquiry-based science investigations. Informal science setting personnel, elementary school teachers, and curriculum specialists charged with designing inquiry-based investigations would be well served by an understanding of the varying influence of certain present factors upon the students' willingness and ability to delve into such higher level inquiries. This study examined young children's use of inquiry-based materials and factors which may influence the level of inquiry they engaged in during informal science activities. An informal science setting was selected as the context for the examination of student inquiry behaviors because of the rich inquiry-based environment present at the site and the benefits previously noted in the research regarding the impact of informal science settings upon the construction of knowledge in science. The study revealed several patterns of behavior among children when they are engaged in inquiry-based activities at informal science exhibits. These repeated behaviors varied in the children's apparent purposeful use of the materials at the exhibits. These levels of inquiry behavior were taxonomically defined as high/medium/low within this study utilizing a researcher-developed tool. Furthermore, in this study adult interventions, questions, or prompting were found to impact the level of inquiry engaged in by the children. This study revealed that higher levels of inquiry were preceded by task directed and physical feature prompts. Moreover, the levels of inquiry behaviors were haltered, even lowered, when preceded by a prompt that focused on a science content or concept question. Results of this study have implications for the enhancement of inquiry-based science activities in elementary schools as well as in informal science settings. These findings have significance for all science educators

  13. Education level inequalities and transportation injury mortality in the middle aged and elderly in European settings

    NARCIS (Netherlands)

    Borrell, C.; Plasència, A.; Huisman, M.; Costa, G.; Kunst, A.; Andersen, O.; Bopp, M.; Borgan, J.-K.; Deboosere, P.; Glickman, M.; Gadeyne, S.; Minder, C.; Regidor, E.; Spadea, T.; Valkonen, T.; Mackenbach, J. P.

    2005-01-01

    OBJECTIVE: To study the differential distribution of transportation injury mortality by educational level in nine European settings, among people older than 30 years, during the 1990s. METHODS: Deaths of men and women older than 30 years from transportation injuries were studied. Rate differences

  14. A thick level set interface model for simulating fatigue-drive delamination in composites

    NARCIS (Netherlands)

    Latifi, M.; Van der Meer, F.P.; Sluys, L.J.

    2015-01-01

    This paper presents a new damage model for simulating fatigue-driven delamination in composite laminates. This model is developed based on the Thick Level Set approach (TLS) and provides a favorable link between damage mechanics and fracture mechanics through the non-local evaluation of the energy

  15. Level of health care and services in a tertiary health setting in Nigeria

    African Journals Online (AJOL)

    Level of health care and services in a tertiary health setting in Nigeria. ... Background: There is a growing awareness and demand for quality health care across the world; hence the ... Doctors and nurses formed 64.3% of the study population.

  16. Two Surface-Tension Formulations For The Level Set Interface-Tracking Method

    International Nuclear Information System (INIS)

    Shepel, S.V.; Smith, B.L.

    2005-01-01

    The paper describes a comparative study of two surface-tension models for the Level Set interface tracking method. In both models, the surface tension is represented as a body force, concentrated near the interface, but the technical implementation of the two options is different. The first is based on a traditional Level Set approach, in which the surface tension is distributed over a narrow band around the interface using a smoothed Delta function. In the second model, which is based on the integral form of the fluid-flow equations, the force is imposed only in those computational cells through which the interface passes. Both models have been incorporated into the Finite-Element/Finite-Volume Level Set method, previously implemented into the commercial Computational Fluid Dynamics (CFD) code CFX-4. A critical evaluation of the two models, undertaken in the context of four standard Level Set benchmark problems, shows that the first model, based on the smoothed Delta function approach, is the more general, and more robust, of the two. (author)

  17. Fast Streaming 3D Level set Segmentation on the GPU for Smooth Multi-phase Segmentation

    DEFF Research Database (Denmark)

    Sharma, Ojaswa; Zhang, Qin; Anton, François

    2011-01-01

    Level set method based segmentation provides an efficient tool for topological and geometrical shape handling, but it is slow due to high computational burden. In this work, we provide a framework for streaming computations on large volumetric images on the GPU. A streaming computational model...

  18. Multi-domain, higher order level set scheme for 3D image segmentation on the GPU

    DEFF Research Database (Denmark)

    Sharma, Ojaswa; Zhang, Qin; Anton, François

    2010-01-01

    to evaluate level set surfaces that are $C^2$ continuous, but are slow due to high computational burden. In this paper, we provide a higher order GPU based solver for fast and efficient segmentation of large volumetric images. We also extend the higher order method to multi-domain segmentation. Our streaming...

  19. An Optimized, Grid Independent, Narrow Band Data Structure for High Resolution Level Sets

    DEFF Research Database (Denmark)

    Nielsen, Michael Bang; Museth, Ken

    2004-01-01

    enforced by the convex boundaries of an underlying cartesian computational grid. Here we present a novel very memory efficient narrow band data structure, dubbed the Sparse Grid, that enables the representation of grid independent high resolution level sets. The key features our new data structure are...

  20. Global mean sea-level rise in a world agreed upon in Paris

    Science.gov (United States)

    Bittermann, Klaus; Rahmstorf, Stefan; Kopp, Robert E.; Kemp, Andrew C.

    2017-12-01

    Although the 2015 Paris Agreement seeks to hold global average temperature to ‘well below 2 °C above pre-industrial levels and to pursue efforts to limit the temperature increase to 1.5 °C above pre-industrial levels’, projections of global mean sea-level (GMSL) rise commonly focus on scenarios in which there is a high probability that warming exceeds 1.5 °C. Using a semi-empirical model, we project GMSL changes between now and 2150 CE under a suite of temperature scenarios that satisfy the Paris Agreement temperature targets. The projected magnitude and rate of GMSL rise varies among these low emissions scenarios. Stabilizing temperature at 1.5 °C instead of 2 °C above preindustrial reduces GMSL in 2150 CE by 17 cm (90% credible interval: 14-21 cm) and reduces peak rates of rise by 1.9 mm yr-1 (90% credible interval: 1.4-2.6 mm yr-1). Delaying the year of peak temperature has little long-term influence on GMSL, but does reduce the maximum rate of rise. Stabilizing at 2 °C in 2080 CE rather than 2030 CE reduces the peak rate by 2.7 mm yr-1 (90% credible interval: 2.0-4.0 mm yr-1).

  1. Scope of physician procedures independently billed by mid-level providers in the office setting.

    Science.gov (United States)

    Coldiron, Brett; Ratnarathorn, Mondhipa

    2014-11-01

    Mid-level providers (nurse practitioners and physician assistants) were originally envisioned to provide primary care services in underserved areas. This study details the current scope of independent procedural billing to Medicare of difficult, invasive, and surgical procedures by medical mid-level providers. To understand the scope of independent billing to Medicare for procedures performed by mid-level providers in an outpatient office setting for a calendar year. Analyses of the 2012 Medicare Physician/Supplier Procedure Summary Master File, which reflects fee-for-service claims that were paid by Medicare, for Current Procedural Terminology procedures independently billed by mid-level providers. Outpatient office setting among health care providers. The scope of independent billing to Medicare for procedures performed by mid-level providers. In 2012, nurse practitioners and physician assistants billed independently for more than 4 million procedures at our cutoff of 5000 paid claims per procedure. Most (54.8%) of these procedures were performed in the specialty area of dermatology. The findings of this study are relevant to safety and quality of care. Recently, the shortage of primary care clinicians has prompted discussion of widening the scope of practice for mid-level providers. It would be prudent to temper widening the scope of practice of mid-level providers by recognizing that mid-level providers are not solely limited to primary care, and may involve procedures for which they may not have formal training.

  2. Why is mean sea level along the Indian coast higher in the Bay of Bengal than in the Arabian Sea?

    Digital Repository Service at National Institute of Oceanography (India)

    Shankar, D.; Shetye, S.R.

    Levelling observations conducted during the Great Trigonometrical Survey of India (1858-1909) and subsequent observations showed that mean sea level along the coast of India is higher in the Bay of Bengal than in the Arabian Sea, the difference...

  3. Online monitoring of oil film using electrical capacitance tomography and level set method

    International Nuclear Information System (INIS)

    Xue, Q.; Ma, M.; Sun, B. Y.; Cui, Z. Q.; Wang, H. X.

    2015-01-01

    In the application of oil-air lubrication system, electrical capacitance tomography (ECT) provides a promising way for monitoring oil film in the pipelines by reconstructing cross sectional oil distributions in real time. While in the case of small diameter pipe and thin oil film, the thickness of the oil film is hard to be observed visually since the interface of oil and air is not obvious in the reconstructed images. And the existence of artifacts in the reconstructions has seriously influenced the effectiveness of image segmentation techniques such as level set method. Besides, level set method is also unavailable for online monitoring due to its low computation speed. To address these problems, a modified level set method is developed: a distance regularized level set evolution formulation is extended to image two-phase flow online using an ECT system, a narrowband image filter is defined to eliminate the influence of artifacts, and considering the continuity of the oil distribution variation, the detected oil-air interface of a former image can be used as the initial contour for the detection of the subsequent frame; thus, the propagation from the initial contour to the boundary can be greatly accelerated, making it possible for real time tracking. To testify the feasibility of the proposed method, an oil-air lubrication facility with 4 mm inner diameter pipe is measured in normal operation using an 8-electrode ECT system. Both simulation and experiment results indicate that the modified level set method is capable of visualizing the oil-air interface accurately online

  4. S-N secular ocean tide: explanation of observably coastal velocities of increase of a global mean sea level and mean sea levels in northern and southern hemispheres and prediction of erroneous altimetry velocities

    Science.gov (United States)

    Barkin, Yury

    2010-05-01

    The phenomenon of contrast secular changes of sea levels in the southern and northern hemispheres, predicted on the basis of geodynamic model about the forced relative oscillations and displacements of the Earth shells, has obtained a theoretical explanation. In northern hemisphere the mean sea level of ocean increases with velocity about 2.45±0.32 mm/yr, and in a southern hemisphere the mean sea level increases with velocity about 0.67±0.30 mm/yr. Theoretical values of velocity of increase of global mean sea level of ocean has been estimated in 1.61±0.36 mm/yr. 1 Introduction. The secular drift of the centre of mass of the Earth in the direction of North Pole with velocity about 12-20 mm/yr has been predicted by author in 1995 [1], [2], and now has confirmed with methods of space geodesy. For example the DORIS data in period 1999-2008 let us to estimate velocity of polar drift in 5.24±0.29 mm/yr [3]. To explain this fundamental planetary phenomenon it is possible only, having admitted, that similar northern drift tests the centre of mass of the liquid core relatively to the centre of mass of viscous-elastic and thermodynamically changeable mantle with velocity about 2-3 cm/yr in present [4]. The polar drift of the Earth core with huge superfluous mass results in slow increase of a gravity in northern hemisphere with a mean velocity about 1.4 ?Gal and to its decrease approximately with the same mean velocity in southern hemisphere [5]. This conclusion-prediction has obtained already a number of confirmations in precision gravimetric observations fulfilled in last decade around the world [6]. Naturally, a drift of the core is accompanied by the global changes (deformations) of all layers of the mantle and the core, by inversion changes of their tension states when in one hemisphere the tension increases and opposite on the contrary - decreases. Also it is possible that thermodynamical mechanism actively works with inversion properties of molting and

  5. INTEGRATED SFM TECHNIQUES USING DATA SET FROM GOOGLE EARTH 3D MODEL AND FROM STREET LEVEL

    Directory of Open Access Journals (Sweden)

    L. Inzerillo

    2017-08-01

    Full Text Available Structure from motion (SfM represents a widespread photogrammetric method that uses the photogrammetric rules to carry out a 3D model from a photo data set collection. Some complex ancient buildings, such as Cathedrals, or Theatres, or Castles, etc. need to implement the data set (realized from street level with the UAV one in order to have the 3D roof reconstruction. Nevertheless, the use of UAV is strong limited from the government rules. In these last years, Google Earth (GE has been enriched with the 3D models of the earth sites. For this reason, it seemed convenient to start to test the potentiality offered by GE in order to extract from it a data set that replace the UAV function, to close the aerial building data set, using screen images of high resolution 3D models. Users can take unlimited “aerial photos” of a scene while flying around in GE at any viewing angle and altitude. The challenge is to verify the metric reliability of the SfM model carried out with an integrated data set (the one from street level and the one from GE aimed at replace the UAV use in urban contest. This model is called integrated GE SfM model (i-GESfM. In this paper will be present a case study: the Cathedral of Palermo.

  6. Introduction to the level-set full field modeling of laths spheroidization phenomenon in α/β titanium alloys

    Directory of Open Access Journals (Sweden)

    Polychronopoulou D.

    2016-01-01

    Full Text Available Fragmentation of α lamellae and subsequent spheroidization of α laths in α/β titanium alloys occurring during and after deformation are well known phenomena. We will illustrate the development of a new finite element methodology to model them. This new methodology is based on a level set framework to model the deformation and the ad hoc simultaneous and/or subsequent interfaces kinetics. We will focus, at yet, on the modeling of the surface diffusion at the α/β phase interfaces and the motion by mean curvature at the α/α grain interfaces.

  7. 23 CFR Appendix A to Part 772 - National Reference Energy Mean Emission Levels as a Function of Speed

    Science.gov (United States)

    2010-04-01

    ... 23 Highways 1 2010-04-01 2010-04-01 false National Reference Energy Mean Emission Levels as a Function of Speed A Appendix A to Part 772 Highways FEDERAL HIGHWAY ADMINISTRATION, DEPARTMENT OF... NOISE Pt. 772, App. A Appendix A to Part 772—National Reference Energy Mean Emission Levels as a...

  8. Toward accurate tooth segmentation from computed tomography images using a hybrid level set model

    Energy Technology Data Exchange (ETDEWEB)

    Gan, Yangzhou; Zhao, Qunfei [Department of Automation, Shanghai Jiao Tong University, and Key Laboratory of System Control and Information Processing, Ministry of Education of China, Shanghai 200240 (China); Xia, Zeyang, E-mail: zy.xia@siat.ac.cn, E-mail: jing.xiong@siat.ac.cn; Hu, Ying [Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, and The Chinese University of Hong Kong, Shenzhen 518055 (China); Xiong, Jing, E-mail: zy.xia@siat.ac.cn, E-mail: jing.xiong@siat.ac.cn [Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, Shenzhen 510855 (China); Zhang, Jianwei [TAMS, Department of Informatics, University of Hamburg, Hamburg 22527 (Germany)

    2015-01-15

    Purpose: A three-dimensional (3D) model of the teeth provides important information for orthodontic diagnosis and treatment planning. Tooth segmentation is an essential step in generating the 3D digital model from computed tomography (CT) images. The aim of this study is to develop an accurate and efficient tooth segmentation method from CT images. Methods: The 3D dental CT volumetric images are segmented slice by slice in a two-dimensional (2D) transverse plane. The 2D segmentation is composed of a manual initialization step and an automatic slice by slice segmentation step. In the manual initialization step, the user manually picks a starting slice and selects a seed point for each tooth in this slice. In the automatic slice segmentation step, a developed hybrid level set model is applied to segment tooth contours from each slice. Tooth contour propagation strategy is employed to initialize the level set function automatically. Cone beam CT (CBCT) images of two subjects were used to tune the parameters. Images of 16 additional subjects were used to validate the performance of the method. Volume overlap metrics and surface distance metrics were adopted to assess the segmentation accuracy quantitatively. The volume overlap metrics were volume difference (VD, mm{sup 3}) and Dice similarity coefficient (DSC, %). The surface distance metrics were average symmetric surface distance (ASSD, mm), RMS (root mean square) symmetric surface distance (RMSSSD, mm), and maximum symmetric surface distance (MSSD, mm). Computation time was recorded to assess the efficiency. The performance of the proposed method has been compared with two state-of-the-art methods. Results: For the tested CBCT images, the VD, DSC, ASSD, RMSSSD, and MSSD for the incisor were 38.16 ± 12.94 mm{sup 3}, 88.82 ± 2.14%, 0.29 ± 0.03 mm, 0.32 ± 0.08 mm, and 1.25 ± 0.58 mm, respectively; the VD, DSC, ASSD, RMSSSD, and MSSD for the canine were 49.12 ± 9.33 mm{sup 3}, 91.57 ± 0.82%, 0.27 ± 0.02 mm, 0

  9. Toward accurate tooth segmentation from computed tomography images using a hybrid level set model

    International Nuclear Information System (INIS)

    Gan, Yangzhou; Zhao, Qunfei; Xia, Zeyang; Hu, Ying; Xiong, Jing; Zhang, Jianwei

    2015-01-01

    Purpose: A three-dimensional (3D) model of the teeth provides important information for orthodontic diagnosis and treatment planning. Tooth segmentation is an essential step in generating the 3D digital model from computed tomography (CT) images. The aim of this study is to develop an accurate and efficient tooth segmentation method from CT images. Methods: The 3D dental CT volumetric images are segmented slice by slice in a two-dimensional (2D) transverse plane. The 2D segmentation is composed of a manual initialization step and an automatic slice by slice segmentation step. In the manual initialization step, the user manually picks a starting slice and selects a seed point for each tooth in this slice. In the automatic slice segmentation step, a developed hybrid level set model is applied to segment tooth contours from each slice. Tooth contour propagation strategy is employed to initialize the level set function automatically. Cone beam CT (CBCT) images of two subjects were used to tune the parameters. Images of 16 additional subjects were used to validate the performance of the method. Volume overlap metrics and surface distance metrics were adopted to assess the segmentation accuracy quantitatively. The volume overlap metrics were volume difference (VD, mm 3 ) and Dice similarity coefficient (DSC, %). The surface distance metrics were average symmetric surface distance (ASSD, mm), RMS (root mean square) symmetric surface distance (RMSSSD, mm), and maximum symmetric surface distance (MSSD, mm). Computation time was recorded to assess the efficiency. The performance of the proposed method has been compared with two state-of-the-art methods. Results: For the tested CBCT images, the VD, DSC, ASSD, RMSSSD, and MSSD for the incisor were 38.16 ± 12.94 mm 3 , 88.82 ± 2.14%, 0.29 ± 0.03 mm, 0.32 ± 0.08 mm, and 1.25 ± 0.58 mm, respectively; the VD, DSC, ASSD, RMSSSD, and MSSD for the canine were 49.12 ± 9.33 mm 3 , 91.57 ± 0.82%, 0.27 ± 0.02 mm, 0.28 ± 0.03 mm

  10. Image-guided regularization level set evolution for MR image segmentation and bias field correction.

    Science.gov (United States)

    Wang, Lingfeng; Pan, Chunhong

    2014-01-01

    Magnetic resonance (MR) image segmentation is a crucial step in surgical and treatment planning. In this paper, we propose a level-set-based segmentation method for MR images with intensity inhomogeneous problem. To tackle the initialization sensitivity problem, we propose a new image-guided regularization to restrict the level set function. The maximum a posteriori inference is adopted to unify segmentation and bias field correction within a single framework. Under this framework, both the contour prior and the bias field prior are fully used. As a result, the image intensity inhomogeneity can be well solved. Extensive experiments are provided to evaluate the proposed method, showing significant improvements in both segmentation and bias field correction accuracies as compared with other state-of-the-art approaches. Copyright © 2014 Elsevier Inc. All rights reserved.

  11. Level Set Projection Method for Incompressible Navier-Stokes on Arbitrary Boundaries

    KAUST Repository

    Williams-Rioux, Bertrand

    2012-01-12

    Second order level set projection method for incompressible Navier-Stokes equations is proposed to solve flow around arbitrary geometries. We used rectilinear grid with collocated cell centered velocity and pressure. An explicit Godunov procedure is used to address the nonlinear advection terms, and an implicit Crank-Nicholson method to update viscous effects. An approximate pressure projection is implemented at the end of the time stepping using multigrid as a conventional fast iterative method. The level set method developed by Osher and Sethian [17] is implemented to address real momentum and pressure boundary conditions by the advection of a distance function, as proposed by Aslam [3]. Numerical results for the Strouhal number and drag coefficients validated the model with good accuracy for flow over a cylinder in the parallel shedding regime (47 < Re < 180). Simulations for an array of cylinders and an oscillating cylinder were performed, with the latter demonstrating our methods ability to handle dynamic boundary conditions.

  12. A Cartesian Adaptive Level Set Method for Two-Phase Flows

    Science.gov (United States)

    Ham, F.; Young, Y.-N.

    2003-01-01

    In the present contribution we develop a level set method based on local anisotropic Cartesian adaptation as described in Ham et al. (2002). Such an approach should allow for the smallest possible Cartesian grid capable of resolving a given flow. The remainder of the paper is organized as follows. In section 2 the level set formulation for free surface calculations is presented and its strengths and weaknesses relative to the other free surface methods reviewed. In section 3 the collocated numerical method is described. In section 4 the method is validated by solving the 2D and 3D drop oscilation problem. In section 5 we present some results from more complex cases including the 3D drop breakup in an impulsively accelerated free stream, and the 3D immiscible Rayleigh-Taylor instability. Conclusions are given in section 6.

  13. A level-set method for two-phase flows with soluble surfactant

    Science.gov (United States)

    Xu, Jian-Jun; Shi, Weidong; Lai, Ming-Chih

    2018-01-01

    A level-set method is presented for solving two-phase flows with soluble surfactant. The Navier-Stokes equations are solved along with the bulk surfactant and the interfacial surfactant equations. In particular, the convection-diffusion equation for the bulk surfactant on the irregular moving domain is solved by using a level-set based diffusive-domain method. A conservation law for the total surfactant mass is derived, and a re-scaling procedure for the surfactant concentrations is proposed to compensate for the surfactant mass loss due to numerical diffusion. The whole numerical algorithm is easy for implementation. Several numerical simulations in 2D and 3D show the effects of surfactant solubility on drop dynamics under shear flow.

  14. Application of the level set method for multi-phase flow computation in fusion engineering

    International Nuclear Information System (INIS)

    Luo, X-Y.; Ni, M-J.; Ying, A.; Abdou, M.

    2006-01-01

    Numerical simulation of multi-phase flow is essential to evaluate the feasibility of a liquid protection scheme for the power plant chamber. The level set method is one of the best methods for computing and analyzing the motion of interface among the multi-phase flow. This paper presents a general formula for the second-order projection method combined with the level set method to simulate unsteady incompressible multi-phase flow with/out phase change flow encountered in fusion science and engineering. The third-order ENO scheme and second-order semi-implicit Crank-Nicholson scheme is used to update the convective and diffusion term. The numerical results show this method can handle the complex deformation of the interface and the effect of liquid-vapor phase change will be included in the future work

  15. Embedded Real-Time Architecture for Level-Set-Based Active Contours

    Directory of Open Access Journals (Sweden)

    Dejnožková Eva

    2005-01-01

    Full Text Available Methods described by partial differential equations have gained a considerable interest because of undoubtful advantages such as an easy mathematical description of the underlying physics phenomena, subpixel precision, isotropy, or direct extension to higher dimensions. Though their implementation within the level set framework offers other interesting advantages, their vast industrial deployment on embedded systems is slowed down by their considerable computational effort. This paper exploits the high parallelization potential of the operators from the level set framework and proposes a scalable, asynchronous, multiprocessor platform suitable for system-on-chip solutions. We concentrate on obtaining real-time execution capabilities. The performance is evaluated on a continuous watershed and an object-tracking application based on a simple gradient-based attraction force driving the active countour. The proposed architecture can be realized on commercially available FPGAs. It is built around general-purpose processor cores, and can run code developed with usual tools.

  16. Level-set-based reconstruction algorithm for EIT lung images: first clinical results.

    Science.gov (United States)

    Rahmati, Peyman; Soleimani, Manuchehr; Pulletz, Sven; Frerichs, Inéz; Adler, Andy

    2012-05-01

    We show the first clinical results using the level-set-based reconstruction algorithm for electrical impedance tomography (EIT) data. The level-set-based reconstruction method (LSRM) allows the reconstruction of non-smooth interfaces between image regions, which are typically smoothed by traditional voxel-based reconstruction methods (VBRMs). We develop a time difference formulation of the LSRM for 2D images. The proposed reconstruction method is applied to reconstruct clinical EIT data of a slow flow inflation pressure-volume manoeuvre in lung-healthy and adult lung-injury patients. Images from the LSRM and the VBRM are compared. The results show comparable reconstructed images, but with an improved ability to reconstruct sharp conductivity changes in the distribution of lung ventilation using the LSRM.

  17. Level-set-based reconstruction algorithm for EIT lung images: first clinical results

    International Nuclear Information System (INIS)

    Rahmati, Peyman; Adler, Andy; Soleimani, Manuchehr; Pulletz, Sven; Frerichs, Inéz

    2012-01-01

    We show the first clinical results using the level-set-based reconstruction algorithm for electrical impedance tomography (EIT) data. The level-set-based reconstruction method (LSRM) allows the reconstruction of non-smooth interfaces between image regions, which are typically smoothed by traditional voxel-based reconstruction methods (VBRMs). We develop a time difference formulation of the LSRM for 2D images. The proposed reconstruction method is applied to reconstruct clinical EIT data of a slow flow inflation pressure–volume manoeuvre in lung-healthy and adult lung-injury patients. Images from the LSRM and the VBRM are compared. The results show comparable reconstructed images, but with an improved ability to reconstruct sharp conductivity changes in the distribution of lung ventilation using the LSRM. (paper)

  18. Kir2.1 channels set two levels of resting membrane potential with inward rectification.

    Science.gov (United States)

    Chen, Kuihao; Zuo, Dongchuan; Liu, Zheng; Chen, Haijun

    2018-04-01

    Strong inward rectifier K + channels (Kir2.1) mediate background K + currents primarily responsible for maintenance of resting membrane potential. Multiple types of cells exhibit two levels of resting membrane potential. Kir2.1 and K2P1 currents counterbalance, partially accounting for the phenomenon of human cardiomyocytes in subphysiological extracellular K + concentrations or pathological hypokalemic conditions. The mechanism of how Kir2.1 channels contribute to the two levels of resting membrane potential in different types of cells is not well understood. Here we test the hypothesis that Kir2.1 channels set two levels of resting membrane potential with inward rectification. Under hypokalemic conditions, Kir2.1 currents counterbalance HCN2 or HCN4 cation currents in CHO cells that heterologously express both channels, generating N-shaped current-voltage relationships that cross the voltage axis three times and reconstituting two levels of resting membrane potential. Blockade of HCN channels eliminated the phenomenon in K2P1-deficient Kir2.1-expressing human cardiomyocytes derived from induced pluripotent stem cells or CHO cells expressing both Kir2.1 and HCN2 channels. Weakly inward rectifier Kir4.1 or inward rectification-deficient Kir2.1•E224G mutant channels do not set such two levels of resting membrane potential when co-expressed with HCN2 channels in CHO cells or when overexpressed in human cardiomyocytes derived from induced pluripotent stem cells. These findings demonstrate a common mechanism that Kir2.1 channels set two levels of resting membrane potential with inward rectification by balancing inward currents through different cation channels such as hyperpolarization-activated HCN channels or hypokalemia-induced K2P1 leak channels.

  19. Computing the dynamics of biomembranes by combining conservative level set and adaptive finite element methods

    OpenAIRE

    Laadhari , Aymen; Saramito , Pierre; Misbah , Chaouqi

    2014-01-01

    International audience; The numerical simulation of the deformation of vesicle membranes under simple shear external fluid flow is considered in this paper. A new saddle-point approach is proposed for the imposition of the fluid incompressibility and the membrane inextensibility constraints, through Lagrange multipliers defined in the fluid and on the membrane respectively. Using a level set formulation, the problem is approximated by mixed finite elements combined with an automatic adaptive ...

  20. Stochastic level-set variational implicit-solvent approach to solute-solvent interfacial fluctuations

    Energy Technology Data Exchange (ETDEWEB)

    Zhou, Shenggao, E-mail: sgzhou@suda.edu.cn, E-mail: bli@math.ucsd.edu [Department of Mathematics and Mathematical Center for Interdiscipline Research, Soochow University, 1 Shizi Street, Jiangsu, Suzhou 215006 (China); Sun, Hui; Cheng, Li-Tien [Department of Mathematics, University of California, San Diego, La Jolla, California 92093-0112 (United States); Dzubiella, Joachim [Soft Matter and Functional Materials, Helmholtz-Zentrum Berlin, 14109 Berlin, Germany and Institut für Physik, Humboldt-Universität zu Berlin, 12489 Berlin (Germany); Li, Bo, E-mail: sgzhou@suda.edu.cn, E-mail: bli@math.ucsd.edu [Department of Mathematics and Quantitative Biology Graduate Program, University of California, San Diego, La Jolla, California 92093-0112 (United States); McCammon, J. Andrew [Department of Chemistry and Biochemistry, Department of Pharmacology, Howard Hughes Medical Institute, University of California, San Diego, La Jolla, California 92093-0365 (United States)

    2016-08-07

    Recent years have seen the initial success of a variational implicit-solvent model (VISM), implemented with a robust level-set method, in capturing efficiently different hydration states and providing quantitatively good estimation of solvation free energies of biomolecules. The level-set minimization of the VISM solvation free-energy functional of all possible solute-solvent interfaces or dielectric boundaries predicts an equilibrium biomolecular conformation that is often close to an initial guess. In this work, we develop a theory in the form of Langevin geometrical flow to incorporate solute-solvent interfacial fluctuations into the VISM. Such fluctuations are crucial to biomolecular conformational changes and binding process. We also develop a stochastic level-set method to numerically implement such a theory. We describe the interfacial fluctuation through the “normal velocity” that is the solute-solvent interfacial force, derive the corresponding stochastic level-set equation in the sense of Stratonovich so that the surface representation is independent of the choice of implicit function, and develop numerical techniques for solving such an equation and processing the numerical data. We apply our computational method to study the dewetting transition in the system of two hydrophobic plates and a hydrophobic cavity of a synthetic host molecule cucurbit[7]uril. Numerical simulations demonstrate that our approach can describe an underlying system jumping out of a local minimum of the free-energy functional and can capture dewetting transitions of hydrophobic systems. In the case of two hydrophobic plates, we find that the wavelength of interfacial fluctuations has a strong influence to the dewetting transition. In addition, we find that the estimated energy barrier of the dewetting transition scales quadratically with the inter-plate distance, agreeing well with existing studies of molecular dynamics simulations. Our work is a first step toward the

  1. Some free boundary problems in potential flow regime usinga based level set method

    Energy Technology Data Exchange (ETDEWEB)

    Garzon, M.; Bobillo-Ares, N.; Sethian, J.A.

    2008-12-09

    Recent advances in the field of fluid mechanics with moving fronts are linked to the use of Level Set Methods, a versatile mathematical technique to follow free boundaries which undergo topological changes. A challenging class of problems in this context are those related to the solution of a partial differential equation posed on a moving domain, in which the boundary condition for the PDE solver has to be obtained from a partial differential equation defined on the front. This is the case of potential flow models with moving boundaries. Moreover the fluid front will possibly be carrying some material substance which will diffuse in the front and be advected by the front velocity, as for example the use of surfactants to lower surface tension. We present a Level Set based methodology to embed this partial differential equations defined on the front in a complete Eulerian framework, fully avoiding the tracking of fluid particles and its known limitations. To show the advantages of this approach in the field of Fluid Mechanics we present in this work one particular application: the numerical approximation of a potential flow model to simulate the evolution and breaking of a solitary wave propagating over a slopping bottom and compare the level set based algorithm with previous front tracking models.

  2. A level set method for cupping artifact correction in cone-beam CT

    International Nuclear Information System (INIS)

    Xie, Shipeng; Li, Haibo; Ge, Qi; Li, Chunming

    2015-01-01

    Purpose: To reduce cupping artifacts and improve the contrast-to-noise ratio in cone-beam computed tomography (CBCT). Methods: A level set method is proposed to reduce cupping artifacts in the reconstructed image of CBCT. The authors derive a local intensity clustering property of the CBCT image and define a local clustering criterion function of the image intensities in a neighborhood of each point. This criterion function defines an energy in terms of the level set functions, which represent a segmentation result and the cupping artifacts. The cupping artifacts are estimated as a result of minimizing this energy. Results: The cupping artifacts in CBCT are reduced by an average of 90%. The results indicate that the level set-based algorithm is practical and effective for reducing the cupping artifacts and preserving the quality of the reconstructed image. Conclusions: The proposed method focuses on the reconstructed image without requiring any additional physical equipment, is easily implemented, and provides cupping correction through a single-scan acquisition. The experimental results demonstrate that the proposed method successfully reduces the cupping artifacts

  3. Stabilized Conservative Level Set Method with Adaptive Wavelet-based Mesh Refinement

    Science.gov (United States)

    Shervani-Tabar, Navid; Vasilyev, Oleg V.

    2016-11-01

    This paper addresses one of the main challenges of the conservative level set method, namely the ill-conditioned behavior of the normal vector away from the interface. An alternative formulation for reconstruction of the interface is proposed. Unlike the commonly used methods which rely on the unit normal vector, Stabilized Conservative Level Set (SCLS) uses a modified renormalization vector with diminishing magnitude away from the interface. With the new formulation, in the vicinity of the interface the reinitialization procedure utilizes compressive flux and diffusive terms only in the normal direction to the interface, thus, preserving the conservative level set properties, while away from the interfaces the directional diffusion mechanism automatically switches to homogeneous diffusion. The proposed formulation is robust and general. It is especially well suited for use with adaptive mesh refinement (AMR) approaches due to need for a finer resolution in the vicinity of the interface in comparison with the rest of the domain. All of the results were obtained using the Adaptive Wavelet Collocation Method, a general AMR-type method, which utilizes wavelet decomposition to adapt on steep gradients in the solution while retaining a predetermined order of accuracy.

  4. Considering Actionability at the Participant's Research Setting Level for Anticipatable Incidental Findings from Clinical Research.

    Science.gov (United States)

    Ortiz-Osorno, Alberto Betto; Ehler, Linda A; Brooks, Judith

    2015-01-01

    Determining what constitutes an anticipatable incidental finding (IF) from clinical research and defining whether, and when, this IF should be returned to the participant have been topics of discussion in the field of human subject protections for the last 10 years. It has been debated that implementing a comprehensive IF-approach that addresses both the responsibility of researchers to return IFs and the expectation of participants to receive them can be logistically challenging. IFs have been debated at different levels, such as the ethical reasoning for considering their disclosure or the need for planning for them during the development of the research study. Some authors have discussed the methods for re-contacting participants for disclosing IFs, as well as the relevance of considering the clinical importance of the IFs. Similarly, other authors have debated about when IFs should be disclosed to participants. However, no author has addressed how the "actionability" of the IFs should be considered, evaluated, or characterized at the participant's research setting level. This paper defines the concept of "Actionability at the Participant's Research Setting Level" (APRSL) for anticipatable IFs from clinical research, discusses some related ethical concepts to justify the APRSL concept, proposes a strategy to incorporate APRSL into the planning and management of IFs, and suggests a strategy for integrating APRSL at each local research setting. © 2015 American Society of Law, Medicine & Ethics, Inc.

  5. Records for radioactive waste management up to repository closure: Managing the primary level information (PLI) set

    International Nuclear Information System (INIS)

    2004-07-01

    The objective of this publication is to highlight the importance of the early establishment of a comprehensive records system to manage primary level information (PLI) as an integrated set of information, not merely as a collection of information, throughout all the phases of radioactive waste management. Early establishment of a comprehensive records system to manage Primary Level Information as an integrated set of information throughout all phases of radioactive waste management is important. In addition to the information described in the waste inventory record keeping system (WIRKS), the PLI of a radioactive waste repository consists of the entire universe of information, data and records related to any aspect of the repository's life cycle. It is essential to establish PLI requirements based on integrated set of needs from Regulators and Waste Managers involved in the waste management chain and to update these requirements as needs change over time. Information flow for radioactive waste management should be back-end driven. Identification of an Authority that will oversee the management of PLI throughout all phases of the radioactive waste management life cycle would guarantee the information flow to future generations. The long term protection of information essential to future generations can only be assured by the timely establishment of a comprehensive and effective RMS capable of capturing, indexing and evaluating all PLI. The loss of intellectual control over the PLI will make it very difficult to subsequently identify the ILI and HLI information sets. At all times prior to the closure of a radioactive waste repository, there should be an identifiable entity with a legally enforceable financial and management responsibility for the continued operation of a PLI Records Management System. The information presented in this publication will assist Member States in ensuring that waste and repository records, relevant for retention after repository closure

  6. Generation and quality assessment of route choice sets in public transport networks by means of RP data analysis

    DEFF Research Database (Denmark)

    Larsen, Marie Karen; Nielsen, Otto Anker; Prato, Carlo Giacomo

    2010-01-01

    Literature in route choice modelling shows that a lot of attention has been devoted to route choices of car drivers, but much less attention has been dedicated to route choices of public transport users. As modelling route choice behaviour consists of generating relevant routes and estimating...... discrete choice models, this paper focuses on the issue of choice set generation in public transport networks. Specifically, this paper describes the generation of choice sets for users of the Greater Copenhagen public transport system by applying a doubly stochastic path generation algorithm...

  7. Topological Hausdorff dimension and level sets of generic continuous functions on fractals

    International Nuclear Information System (INIS)

    Balka, Richárd; Buczolich, Zoltán; Elekes, Márton

    2012-01-01

    Highlights: ► We examine a new fractal dimension, the so called topological Hausdorff dimension. ► The generic continuous function has a level set of maximal Hausdorff dimension. ► This maximal dimension is the topological Hausdorff dimension minus one. ► Homogeneity implies that “most” level sets are of this dimension. ► We calculate the various dimensions of the graph of the generic function. - Abstract: In an earlier paper we introduced a new concept of dimension for metric spaces, the so called topological Hausdorff dimension. For a compact metric space K let dim H K and dim tH K denote its Hausdorff and topological Hausdorff dimension, respectively. We proved that this new dimension describes the Hausdorff dimension of the level sets of the generic continuous function on K, namely sup{ dim H f -1 (y):y∈R} =dim tH K-1 for the generic f ∈ C(K), provided that K is not totally disconnected, otherwise every non-empty level set is a singleton. We also proved that if K is not totally disconnected and sufficiently homogeneous then dim H f −1 (y) = dim tH K − 1 for the generic f ∈ C(K) and the generic y ∈ f(K). The most important goal of this paper is to make these theorems more precise. As for the first result, we prove that the supremum is actually attained on the left hand side of the first equation above, and also show that there may only be a unique level set of maximal Hausdorff dimension. As for the second result, we characterize those compact metric spaces for which for the generic f ∈ C(K) and the generic y ∈ f(K) we have dim H f −1 (y) = dim tH K − 1. We also generalize a result of B. Kirchheim by showing that if K is self-similar then for the generic f ∈ C(K) for every y∈intf(K) we have dim H f −1 (y) = dim tH K − 1. Finally, we prove that the graph of the generic f ∈ C(K) has the same Hausdorff and topological Hausdorff dimension as K.

  8. A combined single-multiphase flow formulation of the premixing phase using the level set method

    International Nuclear Information System (INIS)

    Leskovar, M.; Marn, J.

    1999-01-01

    The premixing phase of a steam explosion covers the interaction of the melt jet or droplets with the water prior to any steam explosion occurring. To get a better insight of the hydrodynamic processes during the premixing phase beside hot premixing experiments, where the water evaporation is significant, also cold isothermal premixing experiments are performed. The specialty of isothermal premixing experiments is that three phases are involved: the water, the air and the spheres phase, but only the spheres phase mixes with the other two phases whereas the water and air phases do not mix and remain separated by a free surface. Our idea therefore was to treat the isothermal premixing process with a combined single-multiphase flow model. In this combined model the water and air phase are treated as a single phase with discontinuous phase properties at the water air interface, whereas the spheres are treated as usually with a multiphase flow model, where the spheres represent the dispersed phase and the common water-air phase represents the continuous phase. The common water-air phase was described with the front capturing method based on the level set formulation. In the level set formulation, the boundary of two-fluid interfaces is modeled as the zero set of a smooth signed normal distance function defined on the entire physical domain. The boundary is then updated by solving a nonlinear equation of the Hamilton-Jacobi type on the whole domain. With this single-multiphase flow model the Queos isothermal premixing Q08 has been simulated. A numerical analysis using different treatments of the water-air interface (level set, high-resolution and upwind) has been performed for the incompressible and compressible case and the results were compared to experimental measurements.(author)

  9. Adaptive nonlocal means filtering based on local noise level for CT denoising

    International Nuclear Information System (INIS)

    Li, Zhoubo; Trzasko, Joshua D.; Lake, David S.; Blezek, Daniel J.; Manduca, Armando; Yu, Lifeng; Fletcher, Joel G.; McCollough, Cynthia H.

    2014-01-01

    Purpose: To develop and evaluate an image-domain noise reduction method based on a modified nonlocal means (NLM) algorithm that is adaptive to local noise level of CT images and to implement this method in a time frame consistent with clinical workflow. Methods: A computationally efficient technique for local noise estimation directly from CT images was developed. A forward projection, based on a 2D fan-beam approximation, was used to generate the projection data, with a noise model incorporating the effects of the bowtie filter and automatic exposure control. The noise propagation from projection data to images was analytically derived. The analytical noise map was validated using repeated scans of a phantom. A 3D NLM denoising algorithm was modified to adapt its denoising strength locally based on this noise map. The performance of this adaptive NLM filter was evaluated in phantom studies in terms of in-plane and cross-plane high-contrast spatial resolution, noise power spectrum (NPS), subjective low-contrast spatial resolution using the American College of Radiology (ACR) accreditation phantom, and objective low-contrast spatial resolution using a channelized Hotelling model observer (CHO). Graphical processing units (GPU) implementation of this noise map calculation and the adaptive NLM filtering were developed to meet demands of clinical workflow. Adaptive NLM was piloted on lower dose scans in clinical practice. Results: The local noise level estimation matches the noise distribution determined from multiple repetitive scans of a phantom, demonstrated by small variations in the ratio map between the analytical noise map and the one calculated from repeated scans. The phantom studies demonstrated that the adaptive NLM filter can reduce noise substantially without degrading the high-contrast spatial resolution, as illustrated by modulation transfer function and slice sensitivity profile results. The NPS results show that adaptive NLM denoising preserves the

  10. Individual and setting level predictors of the implementation of a skin cancer prevention program: a multilevel analysis

    Directory of Open Access Journals (Sweden)

    Brownson Ross C

    2010-05-01

    Full Text Available Abstract Background To achieve widespread cancer control, a better understanding is needed of the factors that contribute to successful implementation of effective skin cancer prevention interventions. This study assessed the relative contributions of individual- and setting-level characteristics to implementation of a widely disseminated skin cancer prevention program. Methods A multilevel analysis was conducted using data from the Pool Cool Diffusion Trial from 2004 and replicated with data from 2005. Implementation of Pool Cool by lifeguards was measured using a composite score (implementation variable, range 0 to 10 that assessed whether the lifeguard performed different components of the intervention. Predictors included lifeguard background characteristics, lifeguard sun protection-related attitudes and behaviors, pool characteristics, and enhanced (i.e., more technical assistance, tailored materials, and incentives are provided versus basic treatment group. Results The mean value of the implementation variable was 4 in both years (2004 and 2005; SD = 2 in 2004 and SD = 3 in 2005 indicating a moderate implementation for most lifeguards. Several individual-level (lifeguard characteristics and setting-level (pool characteristics and treatment group factors were found to be significantly associated with implementation of Pool Cool by lifeguards. All three lifeguard-level domains (lifeguard background characteristics, lifeguard sun protection-related attitudes and behaviors and six pool-level predictors (number of weekly pool visitors, intervention intensity, geographic latitude, pool location, sun safety and/or skin cancer prevention programs, and sun safety programs and policies were included in the final model. The most important predictors of implementation were the number of weekly pool visitors (inverse association and enhanced treatment group (positive association. That is, pools with fewer weekly visitors and pools in the enhanced

  11. Improved inhalation technology for setting safe exposure levels for workplace chemicals

    Science.gov (United States)

    Stuart, Bruce O.

    1993-01-01

    Threshold Limit Values recommended as allowable air concentrations of a chemical in the workplace are often based upon a no-observable-effect-level (NOEL) determined by experimental inhalation studies using rodents. A 'safe level' for human exposure must then be estimated by the use of generalized safety factors in attempts to extrapolate from experimental rodents to man. The recent development of chemical-specific physiologically-based toxicokinetics makes use of measured physiological, biochemical, and metabolic parameters to construct a validated model that is able to 'scale-up' rodent response data to predict the behavior of the chemical in man. This procedure is made possible by recent advances in personal computer software and the emergence of appropriate biological data, and provides an analytical tool for much more reliable risk evaluation and airborne chemical exposure level setting for humans.

  12. Giving meaning to the concept of sustainability in architectural design practices : Setting out the analytical framework of translation

    NARCIS (Netherlands)

    Schröder, Torsten

    2018-01-01

    The question of how to give meaning to the concept of sustainability in architectural design practices is highly contested today. Although architects, engineers, clients, politicians, and others seem to agree that sustainability must be addressed, behind this apparent consensus many ambiguities,

  13. Setting ozone critical levels for protecting horticultural Mediterranean crops: Case study of tomato

    International Nuclear Information System (INIS)

    González-Fernández, I.; Calvo, E.; Gerosa, G.; Bermejo, V.; Marzuoli, R.; Calatayud, V.; Alonso, R.

    2014-01-01

    Seven experiments carried out in Italy and Spain have been used to parameterising a stomatal conductance model and establishing exposure– and dose–response relationships for yield and quality of tomato with the main goal of setting O 3 critical levels (CLe). CLe with confidence intervals, between brackets, were set at an accumulated hourly O 3 exposure over 40 nl l −1 , AOT40 = 8.4 (1.2, 15.6) ppm h and a phytotoxic ozone dose above a threshold of 6 nmol m −2 s −1 , POD6 = 2.7 (0.8, 4.6) mmol m −2 for yield and AOT40 = 18.7 (8.5, 28.8) ppm h and POD6 = 4.1 (2.0, 6.2) mmol m −2 for quality, both indices performing equally well. CLe confidence intervals provide information on the quality of the dataset and should be included in future calculations of O 3 CLe for improving current methodologies. These CLe, derived for sensitive tomato cultivars, should not be applied for quantifying O 3 -induced losses at the risk of making important overestimations of the economical losses associated with O 3 pollution. -- Highlights: • Seven independent experiments from Italy and Spain were analysed. • O 3 critical levels are proposed for the protection of summer horticultural crops. • Exposure- and flux-based O 3 indices performed equally well. • Confidence intervals of the new O 3 critical levels are calculated. • A new method to estimate the degree risk of O 3 damage is proposed. -- Critical levels for tomato yield were set at AOT40 = 8.4 ppm h and POD6 = 2.7 mmol m −2 and confidence intervals should be used for improving O 3 risk assessment

  14. Numerical Modelling of Three-Fluid Flow Using The Level-set Method

    Science.gov (United States)

    Li, Hongying; Lou, Jing; Shang, Zhi

    2014-11-01

    This work presents a numerical model for simulation of three-fluid flow involving two different moving interfaces. These interfaces are captured using the level-set method via two different level-set functions. A combined formulation with only one set of conservation equations for the whole physical domain, consisting of the three different immiscible fluids, is employed. Numerical solution is performed on a fixed mesh using the finite volume method. Surface tension effect is incorporated using the Continuum Surface Force model. Validation of the present model is made against available results for stratified flow and rising bubble in a container with a free surface. Applications of the present model are demonstrated by a variety of three-fluid flow systems including (1) three-fluid stratified flow, (2) two-fluid stratified flow carrying the third fluid in the form of drops and (3) simultaneous rising and settling of two drops in a stationary third fluid. The work is supported by a Thematic and Strategic Research from A*STAR, Singapore (Ref. #: 1021640075).

  15. Use of patient-reported outcomes in outpatient settings as a means of patient involvement and self-management support

    DEFF Research Database (Denmark)

    Mejdahl, Caroline; Nielsen, Berit Kjærside; Hjøllund, Niels Henrik Ingvar

    2016-01-01

    Rationale, aims and objectives: Patient-reported outcomes (PROs) are being implemented in clinical practice across different healthcare settings with varying purposes. Involving patients in reporting outcomes may increase their attention to symptoms and thereby support their self-management. The ...... to strengthen patient involvement and securing benefit from PROs.......Rationale, aims and objectives: Patient-reported outcomes (PROs) are being implemented in clinical practice across different healthcare settings with varying purposes. Involving patients in reporting outcomes may increase their attention to symptoms and thereby support their self......-management. The aim of the present study was to describe patients’ experiences with a web-based PRO system where patients complete a PRO questionnaire at home or in the outpatient clinic prior to a consultation. Moreover, the study aimed to explore how PROs influenced the interaction between patients and clinicians...

  16. Wave energy level and geographic setting correlate with Florida beach water quality.

    Science.gov (United States)

    Feng, Zhixuan; Reniers, Ad; Haus, Brian K; Solo-Gabriele, Helena M; Kelly, Elizabeth A

    2016-03-15

    Many recreational beaches suffer from elevated levels of microorganisms, resulting in beach advisories and closures due to lack of compliance with Environmental Protection Agency guidelines. We conducted the first statewide beach water quality assessment by analyzing decadal records of fecal indicator bacteria (enterococci and fecal coliform) levels at 262 Florida beaches. The objectives were to depict synoptic patterns of beach water quality exceedance along the entire Florida shoreline and to evaluate their relationships with wave condition and geographic location. Percent exceedances based on enterococci and fecal coliform were negatively correlated with both long-term mean wave energy and beach slope. Also, Gulf of Mexico beaches exceeded the thresholds significantly more than Atlantic Ocean ones, perhaps partially due to the lower wave energy. A possible linkage between wave energy level and water quality is beach sand, a pervasive nonpoint source that tends to harbor more bacteria in the low-wave-energy environment. Copyright © 2016 Elsevier Ltd. All rights reserved.

  17. The golden mean, scale free extension of real number system, fuzzy sets and 1/f spectrum in physics and biology

    CERN Document Server

    Datta, D P

    2003-01-01

    We show that the generic 1/f spectrum problem acquires a natural explanation in a class of scale free solutions to the ordinary differential equations. We prove the existence and uniqueness of this class of solutions and show how this leads to a nonstandard, fuzzy extension of the ordinary framework of calculus, and hence, that of the classical dynamics and quantum mechanics. The exceptional role of the golden mean irrational number is also explained.

  18. The golden mean, scale free extension of real number system, fuzzy sets and 1/f spectrum in physics and biology

    International Nuclear Information System (INIS)

    Datta, Dhurjati Prasad

    2003-01-01

    We show that the generic 1/f spectrum problem acquires a natural explanation in a class of scale free solutions to the ordinary differential equations. We prove the existence and uniqueness of this class of solutions and show how this leads to a nonstandard, fuzzy extension of the ordinary framework of calculus, and hence, that of the classical dynamics and quantum mechanics. The exceptional role of the golden mean irrational number is also explained

  19. A nonparametric statistical method for determination of a confidence interval for the mean of a set of results obtained in a laboratory intercomparison

    International Nuclear Information System (INIS)

    Veglia, A.

    1981-08-01

    In cases where sets of data are obviously not normally distributed, the application of a nonparametric method for the estimation of a confidence interval for the mean seems to be more suitable than some other methods because such a method requires few assumptions about the population of data. A two-step statistical method is proposed which can be applied to any set of analytical results: elimination of outliers by a nonparametric method based on Tchebycheff's inequality, and determination of a confidence interval for the mean by a non-parametric method based on binominal distribution. The method is appropriate only for samples of size n>=10

  20. Social Connectedness and Life Satisfaction: Comparing Mean Levels for 2 Undergraduate Samples and Testing for Improvement Based on Brief Counseling

    Science.gov (United States)

    Blau, Gary; DiMino, John; DeMaria, Peter A.; Beverly, Clyde; Chessler, Marcy; Drennan, Rob

    2016-01-01

    Objectives: Comparing the mean levels of social connectedness and life satisfaction, and analyzing their relationship for 2 undergraduate samples, and testing for an increase in their means for a brief counseling sample. Participants: Between October 2013 and May 2015, 3 samples were collected: not-in-counseling (NIC; n = 941), initial counseling…

  1. Nurses' comfort level with spiritual assessment: a study among nurses working in diverse healthcare settings.

    Science.gov (United States)

    Cone, Pamela H; Giske, Tove

    2017-10-01

    To gain knowledge about nurses' comfort level in assessing spiritual matters and to learn what questions nurses use in practice related to spiritual assessment. Spirituality is important in holistic nursing care; however, nurses report feeling uncomfortable and ill-prepared to address this domain with patients. Education is reported to impact nurses' ability to engage in spiritual care. This cross-sectional exploratory survey reports on a mixed-method study examining how comfortable nurses are with spiritual assessment. In 2014, a 21-item survey with 10 demographic variables and three open-ended questions were distributed to Norwegian nurses working in diverse care settings with 172 nurse responses (72 % response rate). SPSS was used to analyse quantitative data; thematic analysis examined the open-ended questions. Norwegian nurses reported a high level of comfort with most questions even though spirituality is seen as private. Nurses with some preparation or experience in spiritual care were most comfortable assessing spirituality. Statistically significant correlations were found between the nurses' comfort level with spiritual assessment and their preparedness and sense of the importance of spiritual assessment. How well-prepared nurses felt was related to years of experience, degree of spirituality and religiosity, and importance of spiritual assessment. Many nurses are poorly prepared for spiritual assessment and care among patients in diverse care settings; educational preparation increases their comfort level with facilitating such care. Nurses who feel well prepared with spirituality feel more comfortable with the spiritual domain. By fostering a culture where patients' spirituality is discussed and reflected upon in everyday practice and in continued education, nurses' sense of preparedness, and thus their level of comfort, can increase. Clinical supervision and interprofessional collaboration with hospital chaplains and/or other spiritual leaders can

  2. Segmentation of teeth in CT volumetric dataset by panoramic projection and variational level set

    International Nuclear Information System (INIS)

    Hosntalab, Mohammad; Aghaeizadeh Zoroofi, Reza; Abbaspour Tehrani-Fard, Ali; Shirani, Gholamreza

    2008-01-01

    Quantification of teeth is of clinical importance for various computer assisted procedures such as dental implant, orthodontic planning, face, jaw and cosmetic surgeries. In this regard, segmentation is a major step. In this paper, we propose a method for segmentation of teeth in volumetric computed tomography (CT) data using panoramic re-sampling of the dataset in the coronal view and variational level set. The proposed method consists of five steps as follows: first, we extract a mask in a CT images using Otsu thresholding. Second, the teeth are segmented from other bony tissues by utilizing anatomical knowledge of teeth in the jaws. Third, the proposed method is followed by estimating the arc of the upper and lower jaws and panoramic re-sampling of the dataset. Separation of upper and lower jaws and initial segmentation of teeth are performed by employing the horizontal and vertical projections of the panoramic dataset, respectively. Based the above mentioned procedures an initial mask for each tooth is obtained. Finally, we utilize the initial mask of teeth and apply a Variational level set to refine initial teeth boundaries to final contours. The proposed algorithm was evaluated in the presence of 30 multi-slice CT datasets including 3,600 images. Experimental results reveal the effectiveness of the proposed method. In the proposed algorithm, the variational level set technique was utilized to trace the contour of the teeth. In view of the fact that, this technique is based on the characteristic of the overall region of the teeth image, it is possible to extract a very smooth and accurate tooth contour using this technique. In the presence of the available datasets, the proposed technique was successful in teeth segmentation compared to previous techniques. (orig.)

  3. Segmentation of teeth in CT volumetric dataset by panoramic projection and variational level set

    Energy Technology Data Exchange (ETDEWEB)

    Hosntalab, Mohammad [Islamic Azad University, Faculty of Engineering, Science and Research Branch, Tehran (Iran); Aghaeizadeh Zoroofi, Reza [University of Tehran, Control and Intelligent Processing Center of Excellence, School of Electrical and Computer Engineering, College of Engineering, Tehran (Iran); Abbaspour Tehrani-Fard, Ali [Islamic Azad University, Faculty of Engineering, Science and Research Branch, Tehran (Iran); Sharif University of Technology, Department of Electrical Engineering, Tehran (Iran); Shirani, Gholamreza [Faculty of Dentistry Medical Science of Tehran University, Oral and Maxillofacial Surgery Department, Tehran (Iran)

    2008-09-15

    Quantification of teeth is of clinical importance for various computer assisted procedures such as dental implant, orthodontic planning, face, jaw and cosmetic surgeries. In this regard, segmentation is a major step. In this paper, we propose a method for segmentation of teeth in volumetric computed tomography (CT) data using panoramic re-sampling of the dataset in the coronal view and variational level set. The proposed method consists of five steps as follows: first, we extract a mask in a CT images using Otsu thresholding. Second, the teeth are segmented from other bony tissues by utilizing anatomical knowledge of teeth in the jaws. Third, the proposed method is followed by estimating the arc of the upper and lower jaws and panoramic re-sampling of the dataset. Separation of upper and lower jaws and initial segmentation of teeth are performed by employing the horizontal and vertical projections of the panoramic dataset, respectively. Based the above mentioned procedures an initial mask for each tooth is obtained. Finally, we utilize the initial mask of teeth and apply a Variational level set to refine initial teeth boundaries to final contours. The proposed algorithm was evaluated in the presence of 30 multi-slice CT datasets including 3,600 images. Experimental results reveal the effectiveness of the proposed method. In the proposed algorithm, the variational level set technique was utilized to trace the contour of the teeth. In view of the fact that, this technique is based on the characteristic of the overall region of the teeth image, it is possible to extract a very smooth and accurate tooth contour using this technique. In the presence of the available datasets, the proposed technique was successful in teeth segmentation compared to previous techniques. (orig.)

  4. Level Set-Based Topology Optimization for the Design of an Electromagnetic Cloak With Ferrite Material

    DEFF Research Database (Denmark)

    Otomori, Masaki; Yamada, Takayuki; Andkjær, Jacob Anders

    2013-01-01

    . A level set-based topology optimization method incorporating a fictitious interface energy is used to find optimized configurations of the ferrite material. The numerical results demonstrate that the optimization successfully found an appropriate ferrite configuration that functions as an electromagnetic......This paper presents a structural optimization method for the design of an electromagnetic cloak made of ferrite material. Ferrite materials exhibit a frequency-dependent degree of permeability, due to a magnetic resonance phenomenon that can be altered by changing the magnitude of an externally...

  5. Joint level-set and spatio-temporal motion detection for cell segmentation.

    Science.gov (United States)

    Boukari, Fatima; Makrogiannis, Sokratis

    2016-08-10

    Cell segmentation is a critical step for quantification and monitoring of cell cycle progression, cell migration, and growth control to investigate cellular immune response, embryonic development, tumorigenesis, and drug effects on live cells in time-lapse microscopy images. In this study, we propose a joint spatio-temporal diffusion and region-based level-set optimization approach for moving cell segmentation. Moving regions are initially detected in each set of three consecutive sequence images by numerically solving a system of coupled spatio-temporal partial differential equations. In order to standardize intensities of each frame, we apply a histogram transformation approach to match the pixel intensities of each processed frame with an intensity distribution model learned from all frames of the sequence during the training stage. After the spatio-temporal diffusion stage is completed, we compute the edge map by nonparametric density estimation using Parzen kernels. This process is followed by watershed-based segmentation and moving cell detection. We use this result as an initial level-set function to evolve the cell boundaries, refine the delineation, and optimize the final segmentation result. We applied this method to several datasets of fluorescence microscopy images with varying levels of difficulty with respect to cell density, resolution, contrast, and signal-to-noise ratio. We compared the results with those produced by Chan and Vese segmentation, a temporally linked level-set technique, and nonlinear diffusion-based segmentation. We validated all segmentation techniques against reference masks provided by the international Cell Tracking Challenge consortium. The proposed approach delineated cells with an average Dice similarity coefficient of 89 % over a variety of simulated and real fluorescent image sequences. It yielded average improvements of 11 % in segmentation accuracy compared to both strictly spatial and temporally linked Chan

  6. A multilevel, level-set method for optimizing eigenvalues in shape design problems

    International Nuclear Information System (INIS)

    Haber, E.

    2004-01-01

    In this paper, we consider optimal design problems that involve shape optimization. The goal is to determine the shape of a certain structure such that it is either as rigid or as soft as possible. To achieve this goal we combine two new ideas for an efficient solution of the problem. First, we replace the eigenvalue problem with an approximation by using inverse iteration. Second, we use a level set method but rather than propagating the front we use constrained optimization methods combined with multilevel continuation techniques. Combining these two ideas we obtain a robust and rapid method for the solution of the optimal design problem

  7. Modeling Restrained Shrinkage Induced Cracking in Concrete Rings Using the Thick Level Set Approach

    Directory of Open Access Journals (Sweden)

    Rebecca Nakhoul

    2018-03-01

    Full Text Available Modeling restrained shrinkage-induced damage and cracking in concrete is addressed herein. The novel Thick Level Set (TLS damage growth and crack propagation model is used and adapted by introducing shrinkage contribution into the formulation. The TLS capacity to predict damage evolution, crack initiation and growth triggered by restrained shrinkage in absence of external loads is evaluated. A study dealing with shrinkage-induced cracking in elliptical concrete rings is presented herein. Key results such as the effect of rings oblateness on stress distribution and critical shrinkage strain needed to initiate damage are highlighted. In addition, crack positions are compared to those observed in experiments and are found satisfactory.

  8. Microwave imaging of dielectric cylinder using level set method and conjugate gradient algorithm

    International Nuclear Information System (INIS)

    Grayaa, K.; Bouzidi, A.; Aguili, T.

    2011-01-01

    In this paper, we propose a computational method for microwave imaging cylinder and dielectric object, based on combining level set technique and the conjugate gradient algorithm. By measuring the scattered field, we tried to retrieve the shape, localisation and the permittivity of the object. The forward problem is solved by the moment method, while the inverse problem is reformulate in an optimization one and is solved by the proposed scheme. It found that the proposed method is able to give good reconstruction quality in terms of the reconstructed shape and permittivity.

  9. 'When measurements mean action' decision models for portal image review to eliminate systematic set-up errors

    International Nuclear Information System (INIS)

    Wratten, C.R.; Denham, J.W.; O; Brien, P.; Hamilton, C.S.; Kron, T.; London Regional Cancer Centre, London, Ontario

    2004-01-01

    The aim of the present paper is to evaluate how the use of decision models in the review of portal images can eliminate systematic set-up errors during conformal therapy. Sixteen patients undergoing four-field irradiation of prostate cancer have had daily portal images obtained during the first two treatment weeks and weekly thereafter. The magnitude of random and systematic variations has been calculated by comparison of the portal image with the reference simulator images using the two-dimensional decision model embodied in the Hotelling's evaluation process (HEP). Random day-to-day set-up variation was small in this group of patients. Systematic errors were, however, common. In 15 of 16 patients, one or more errors of >2 mm were diagnosed at some stage during treatment. Sixteen of the 23 errors were between 2 and 4 mm. Although there were examples of oversensitivity of the HEP in three cases, and one instance of undersensitivity, the HEP proved highly sensitive to the small (2-4 mm) systematic errors that must be eliminated during high precision radiotherapy. The HEP has proven valuable in diagnosing very small ( 4 mm) systematic errors using one-dimensional decision models, HEP can eliminate the majority of systematic errors during the first 2 treatment weeks. Copyright (2004) Blackwell Science Pty Ltd

  10. Remote wind stress influence on mean sea level in a subtropical coastal region

    Directory of Open Access Journals (Sweden)

    Mabel Calim Costa

    2012-09-01

    Full Text Available The purpose of this study was to assess the relative influence of remote wind stress on mean sea level (MSL variations in the coastal region of Cananeia (Sao Paulo State, Southern Brazil during the period from 1/1/1955 to 12/31/1993. An optimized low-pass Thompson filter for the study area, and spectral analysis (cross spectrum, coherence and phase lag of the relationship between the MSL and both parallel (T// and perpendicular (T| wind stress components were applied. These were extracted from four grid points of the NCEP/NCAR global model. The predominance of annual oscillations as those of greatest coherence and energy, of periods of approximately 341 days (frequency of 0.00293 cpd and 410 days (frequency of 0.00244 cpd, respectively, were observed. Offshore NCEP/NCAR grid points were those with the highest coherence and energy throughout the study in relation to the observed MSL. This may be linked to the restriction of the NCEP/NCAR model as regards the inland limit. It is also concluded that remote wind stress may play an important role in several MSL time scales, including the annual ones. Based on criteria such as coherence and energy peaks, the wind stress component of greatest effect on MSL was the parallel one.O presente estudo tem por objetivo avaliar a influência relativa de tensão do vento remoto na variação do nível médio do mar (NMM para a região costeira de Cananéia (SP durante o período de 1/1/1955 a 31/12/1993. Foram aplicados um filtro de passa-baixa de Thompson (1983, otimizado para a região de Cananéia, além de análise espectral (espectro cruzado, coerência e defasagem entre o NMM e as componentes paralela (T// e perpendicular (T| da tensão do vento. Estas foram extraídas de quatro pontos de grade do modelo global NCEP/NCAR. Observou-se a predominância das oscilações anuais como aquelas de maior coerência e energia, destacando-se os períodos de aproximadamente 341 dias (frequência de 0,00293 cpd e 410

  11. Implications of sea-level rise in a modern carbonate ramp setting

    Science.gov (United States)

    Lokier, Stephen W.; Court, Wesley M.; Onuma, Takumi; Paul, Andreas

    2018-03-01

    This study addresses a gap in our understanding of the effects of sea-level rise on the sedimentary systems and morphological development of recent and ancient carbonate ramp settings. Many ancient carbonate sequences are interpreted as having been deposited in carbonate ramp settings. These settings are poorly-represented in the Recent. The study documents the present-day transgressive flooding of the Abu Dhabi coastline at the southern shoreline of the Arabian/Persian Gulf, a carbonate ramp depositional system that is widely employed as a Recent analogue for numerous ancient carbonate systems. Fourteen years of field-based observations are integrated with historical and recent high-resolution satellite imagery in order to document and assess the onset of flooding. Predicted rates of transgression (i.e. landward movement of the shoreline) of 2.5 m yr- 1 (± 0.2 m yr- 1) based on global sea-level rise alone were far exceeded by the flooding rate calculated from the back-stepping of coastal features (10-29 m yr- 1). This discrepancy results from the dynamic nature of the flooding with increased water depth exposing the coastline to increased erosion and, thereby, enhancing back-stepping. A non-accretionary transgressive shoreline trajectory results from relatively rapid sea-level rise coupled with a low-angle ramp geometry and a paucity of sediments. The flooding is represented by the landward migration of facies belts, a range of erosive features and the onset of bioturbation. Employing Intergovernmental Panel on Climate Change (Church et al., 2013) predictions for 21st century sea-level rise, and allowing for the post-flooding lag time that is typical for the start-up of carbonate factories, it is calculated that the coastline will continue to retrograde for the foreseeable future. Total passive flooding (without considering feedback in the modification of the shoreline) by the year 2100 is calculated to likely be between 340 and 571 m with a flooding rate of 3

  12. Robust space-time extraction of ventricular surface evolution using multiphase level sets

    Science.gov (United States)

    Drapaca, Corina S.; Cardenas, Valerie; Studholme, Colin

    2004-05-01

    This paper focuses on the problem of accurately extracting the CSF-tissue boundary, particularly around the ventricular surface, from serial structural MRI of the brain acquired in imaging studies of aging and dementia. This is a challenging problem because of the common occurrence of peri-ventricular lesions which locally alter the appearance of white matter. We examine a level set approach which evolves a four dimensional description of the ventricular surface over time. This has the advantage of allowing constraints on the contour in the temporal dimension, improving the consistency of the extracted object over time. We follow the approach proposed by Chan and Vese which is based on the Mumford and Shah model and implemented using the Osher and Sethian level set method. We have extended this to the 4 dimensional case to propagate a 4D contour toward the tissue boundaries through the evolution of a 5D implicit function. For convergence we use region-based information provided by the image rather than the gradient of the image. This is adapted to allow intensity contrast changes between time frames in the MRI sequence. Results on time sequences of 3D brain MR images are presented and discussed.

  13. Topology optimization in acoustics and elasto-acoustics via a level-set method

    Science.gov (United States)

    Desai, J.; Faure, A.; Michailidis, G.; Parry, G.; Estevez, R.

    2018-04-01

    Optimizing the shape and topology (S&T) of structures to improve their acoustic performance is quite challenging. The exact position of the structural boundary is usually of critical importance, which dictates the use of geometric methods for topology optimization instead of standard density approaches. The goal of the present work is to investigate different possibilities for handling topology optimization problems in acoustics and elasto-acoustics via a level-set method. From a theoretical point of view, we detail two equivalent ways to perform the derivation of surface-dependent terms and propose a smoothing technique for treating problems of boundary conditions optimization. In the numerical part, we examine the importance of the surface-dependent term in the shape derivative, neglected in previous studies found in the literature, on the optimal designs. Moreover, we test different mesh adaptation choices, as well as technical details related to the implicit surface definition in the level-set approach. We present results in two and three-space dimensions.

  14. A mass conserving level set method for detailed numerical simulation of liquid atomization

    Energy Technology Data Exchange (ETDEWEB)

    Luo, Kun; Shao, Changxiao [State Key Laboratory of Clean Energy Utilization, Zhejiang University, Hangzhou 310027 (China); Yang, Yue [State Key Laboratory of Turbulence and Complex Systems, Peking University, Beijing 100871 (China); Fan, Jianren, E-mail: fanjr@zju.edu.cn [State Key Laboratory of Clean Energy Utilization, Zhejiang University, Hangzhou 310027 (China)

    2015-10-01

    An improved mass conserving level set method for detailed numerical simulations of liquid atomization is developed to address the issue of mass loss in the existing level set method. This method introduces a mass remedy procedure based on the local curvature at the interface, and in principle, can ensure the absolute mass conservation of the liquid phase in the computational domain. Three benchmark cases, including Zalesak's disk, a drop deforming in a vortex field, and the binary drop head-on collision, are simulated to validate the present method, and the excellent agreement with exact solutions or experimental results is achieved. It is shown that the present method is able to capture the complex interface with second-order accuracy and negligible additional computational cost. The present method is then applied to study more complex flows, such as a drop impacting on a liquid film and the swirling liquid sheet atomization, which again, demonstrates the advantages of mass conservation and the capability to represent the interface accurately.

  15. On the Relationship between Variational Level Set-Based and SOM-Based Active Contours

    Science.gov (United States)

    Abdelsamea, Mohammed M.; Gnecco, Giorgio; Gaber, Mohamed Medhat; Elyan, Eyad

    2015-01-01

    Most Active Contour Models (ACMs) deal with the image segmentation problem as a functional optimization problem, as they work on dividing an image into several regions by optimizing a suitable functional. Among ACMs, variational level set methods have been used to build an active contour with the aim of modeling arbitrarily complex shapes. Moreover, they can handle also topological changes of the contours. Self-Organizing Maps (SOMs) have attracted the attention of many computer vision scientists, particularly in modeling an active contour based on the idea of utilizing the prototypes (weights) of a SOM to control the evolution of the contour. SOM-based models have been proposed in general with the aim of exploiting the specific ability of SOMs to learn the edge-map information via their topology preservation property and overcoming some drawbacks of other ACMs, such as trapping into local minima of the image energy functional to be minimized in such models. In this survey, we illustrate the main concepts of variational level set-based ACMs, SOM-based ACMs, and their relationship and review in a comprehensive fashion the development of their state-of-the-art models from a machine learning perspective, with a focus on their strengths and weaknesses. PMID:25960736

  16. NEW APPROACHES: Measurement of the mean lifetime of cosmic ray muons in the A-level laboratory

    Science.gov (United States)

    Dunne, Peter; Costich, David; O'Sullivan, Sean

    1998-09-01

    The Turning Points in Physics module from the NEAB A-level Modular Physics syllabus requires students to have an understanding of relativistic time dilation and offers the measurement of the mean lifetime of cosmic ray muons as an example of supporting experimental evidence. This article describes a direct measurement of muon lifetime carried out in the A-level laboratory.

  17. HPC in Basin Modeling: Simulating Mechanical Compaction through Vertical Effective Stress using Level Sets

    Science.gov (United States)

    McGovern, S.; Kollet, S. J.; Buerger, C. M.; Schwede, R. L.; Podlaha, O. G.

    2017-12-01

    In the context of sedimentary basins, we present a model for the simulation of the movement of ageological formation (layers) during the evolution of the basin through sedimentation and compactionprocesses. Assuming a single phase saturated porous medium for the sedimentary layers, the modelfocuses on the tracking of the layer interfaces, through the use of the level set method, as sedimentationdrives fluid-flow and reduction of pore space by compaction. On the assumption of Terzaghi's effectivestress concept, the coupling of the pore fluid pressure to the motion of interfaces in 1-D is presented inMcGovern, et.al (2017) [1] .The current work extends the spatial domain to 3-D, though we maintain the assumption ofvertical effective stress to drive the compaction. The idealized geological evolution is conceptualized asthe motion of interfaces between rock layers, whose paths are determined by the magnitude of a speedfunction in the direction normal to the evolving layer interface. The speeds normal to the interface aredependent on the change in porosity, determined through an effective stress-based compaction law,such as the exponential Athy's law. Provided with the speeds normal to the interface, the level setmethod uses an advection equation to evolve a potential function, whose zero level set defines theinterface. Thus, the moving layer geometry influences the pore pressure distribution which couplesback to the interface speeds. The flexible construction of the speed function allows extension, in thefuture, to other terms to represent different physical processes, analogous to how the compaction rulerepresents material deformation.The 3-D model is implemented using the generic finite element method framework Deal II,which provides tools, building on p4est and interfacing to PETSc, for the massively parallel distributedsolution to the model equations [2]. Experiments are being run on the Juelich Supercomputing Center'sJureca cluster. [1] McGovern, et.al. (2017

  18. Identification of Arbitrary Zonation in Groundwater Parameters using the Level Set Method and a Parallel Genetic Algorithm

    Science.gov (United States)

    Lei, H.; Lu, Z.; Vesselinov, V. V.; Ye, M.

    2017-12-01

    Simultaneous identification of both the zonation structure of aquifer heterogeneity and the hydrogeological parameters associated with these zones is challenging, especially for complex subsurface heterogeneity fields. In this study, a new approach, based on the combination of the level set method and a parallel genetic algorithm is proposed. Starting with an initial guess for the zonation field (including both zonation structure and the hydraulic properties of each zone), the level set method ensures that material interfaces are evolved through the inverse process such that the total residual between the simulated and observed state variables (hydraulic head) always decreases, which means that the inversion result depends on the initial guess field and the minimization process might fail if it encounters a local minimum. To find the global minimum, the genetic algorithm (GA) is utilized to explore the parameters that define initial guess fields, and the minimal total residual corresponding to each initial guess field is considered as the fitness function value in the GA. Due to the expensive evaluation of the fitness function, a parallel GA is adapted in combination with a simulated annealing algorithm. The new approach has been applied to several synthetic cases in both steady-state and transient flow fields, including a case with real flow conditions at the chromium contaminant site at the Los Alamos National Laboratory. The results show that this approach is capable of identifying the arbitrary zonation structures of aquifer heterogeneity and the hydrogeological parameters associated with these zones effectively.

  19. Finding meaning in art: Preferred levels of ambiguity in art appreciation

    Science.gov (United States)

    Jakesch, Martina; Leder, Helmut

    2011-01-01

    Uncertainty is typically not desirable in everyday experiences, but uncertainty in the form of ambiguity may be a defining feature of aesthetic experiences of modern art. In this study, we examined different hypotheses concerning the quantity and quality of information appreciated in art. Artworks were shown together with auditorily presented statements. We tested whether the amount of information, the amount of matching information, or the proportion of matching to nonmatching statements apparent in a picture (levels of ambiguity) affect liking and interestingness. Only the levels of ambiguity predicted differences in the two dependent variables. These findings reveal that ambiguity is an important determinant of aesthetic appreciation and that a certain level of ambiguity is appreciable. PMID:19565431

  20. Flood warning level forecasting for ungauged catchments by means of a combined API storage concept

    International Nuclear Information System (INIS)

    Lehmann, T; Holzmann, H

    2008-01-01

    The knowledge of the expected dimension of the flood peak is of major importance for security and warning services to take preventive measures. In this paper the authors want to introduce the concept of the Antecedent Precipitation Index (API) as a possible variable to estimate runoff warning classes. The aim was (a) to define API warning classes which correspond to runoff warning classes at a certain runoff gauge and (b) apply the method to ungauged basins. To consider time and state dependant rainfall losses a spatially distributed linear storage concept was applied to intercept the actual rainfall. The 3-parameter API function was fitted to several flood events at observed gauges within the district of lower Austria and lead to a set of optimized parameters. Through extreme value statistics the 1, 5 and 30 years API extremes were derived and set into correlation to the corresponding flood events. These API extremes together with the optimized API parameters were spatially interpolated and thus transferred to ungauged basins. The calculated flood events had the tendency to underestimate the smaller flood frequencies whereas the extreme flood classes could be reliably performed.

  1. CT Findings of Disease with Elevated Serum D-Dimer Levels in an Emergency Room Setting

    Energy Technology Data Exchange (ETDEWEB)

    Choi, Ji Youn; Kwon, Woo Cheol; Kim, Young Ju [Dept. of Radiology, Wonju Christian Hospital, Yensei University Wonju College of Medicine, Wonju (Korea, Republic of)

    2012-01-15

    Pulmonary embolism and deep vein thrombosis are the leading causes of elevated serum D-dimer levels in the emergency room. Although D-dimer is a useful screening test because of its high sensitivity and negative predictive value, it has a low specificity. In addition, D-dimer can be elevated in various diseases. Therefore, information on the various diseases with elevated D-dimer levels and their radiologic findings may allow for accurate diagnosis and proper management. Herein, we report the CT findings of various diseases with elevated D-dimer levels in an emergency room setting, including an intravascular contrast filling defect with associated findings in a venous thromboembolism, fracture with soft tissue swelling and hematoma formation in a trauma patient, enlargement with contrast enhancement in the infected organ of a patient, coronary artery stenosis with a perfusion defect of the myocardium in a patient with acute myocardial infarction, high density of acute thrombus in a cerebral vessel with a low density of affected brain parenchyma in an acute cerebral infarction, intimal flap with two separated lumens in a case of aortic dissection, organ involvement of malignancy in a cancer patient, and atrophy of a liver with a dilated portal vein and associated findings.

  2. CT Findings of Disease with Elevated Serum D-Dimer Levels in an Emergency Room Setting

    International Nuclear Information System (INIS)

    Choi, Ji Youn; Kwon, Woo Cheol; Kim, Young Ju

    2012-01-01

    Pulmonary embolism and deep vein thrombosis are the leading causes of elevated serum D-dimer levels in the emergency room. Although D-dimer is a useful screening test because of its high sensitivity and negative predictive value, it has a low specificity. In addition, D-dimer can be elevated in various diseases. Therefore, information on the various diseases with elevated D-dimer levels and their radiologic findings may allow for accurate diagnosis and proper management. Herein, we report the CT findings of various diseases with elevated D-dimer levels in an emergency room setting, including an intravascular contrast filling defect with associated findings in a venous thromboembolism, fracture with soft tissue swelling and hematoma formation in a trauma patient, enlargement with contrast enhancement in the infected organ of a patient, coronary artery stenosis with a perfusion defect of the myocardium in a patient with acute myocardial infarction, high density of acute thrombus in a cerebral vessel with a low density of affected brain parenchyma in an acute cerebral infarction, intimal flap with two separated lumens in a case of aortic dissection, organ involvement of malignancy in a cancer patient, and atrophy of a liver with a dilated portal vein and associated findings.

  3. Evaluation of EGM2008 by means of GPS Levelling Uganda | Abeho ...

    African Journals Online (AJOL)

    For testing the model, a total of seven levelled benchmarks available in Uganda which belong to the New Khartoum datum were used. The spatial positions of these benchmarks were determined at mm accuracy, with respect to ITRF2008. The agreement between the EGM2008 geoid and the geoid undulation derived from ...

  4. Sound pressure level tools design used in occupational health by means of Labview software

    Directory of Open Access Journals (Sweden)

    Farhad Forouharmajd

    2015-01-01

    Conclusion: LabVIEW programming capabilities in the field of sound can be referred to the measurement of sound, frequency analysis, and sound control that actually the software acts like a sound level meter and sound analyzer. According to the mentioned features, we can use this software to analyze and process sound and vibration as a monitoring system.

  5. Defining the Levels of Adjustable Autonomy: A Means of Improving Resilience in an Unmanned Aerial System

    Science.gov (United States)

    2014-09-01

    implemented in a system, some level of human-operator involvement will be required in interacting with that system (Glas and Kanda 2012). This is the...September 23–24, 2010. Glas, Dylan F., Takayuki Kanda , Hiroshi Ishiguro, and Norihiro Hagita. 2012. Teleoperation of Multiple Social Robots." IEEE

  6. Transport equations, Level Set and Eulerian mechanics. Application to fluid-structure coupling

    International Nuclear Information System (INIS)

    Maitre, E.

    2008-11-01

    My works were devoted to numerical analysis of non-linear elliptic-parabolic equations, to neutron transport equation and to the simulation of fabrics draping. More recently I developed an Eulerian method based on a level set formulation of the immersed boundary method to deal with fluid-structure coupling problems arising in bio-mechanics. Some of the more efficient algorithms to solve the neutron transport equation make use of the splitting of the transport operator taking into account its characteristics. In the present work we introduced a new algorithm based on this splitting and an adaptation of minimal residual methods to infinite dimensional case. We present the case where the velocity space is of dimension 1 (slab geometry) and 2 (plane geometry) because the splitting is simpler in the former

  7. Numerical simulation of overflow at vertical weirs using a hybrid level set/VOF method

    Science.gov (United States)

    Lv, Xin; Zou, Qingping; Reeve, Dominic

    2011-10-01

    This paper presents the applications of a newly developed free surface flow model to the practical, while challenging overflow problems for weirs. Since the model takes advantage of the strengths of both the level set and volume of fluid methods and solves the Navier-Stokes equations on an unstructured mesh, it is capable of resolving the time evolution of very complex vortical motions, air entrainment and pressure variations due to violent deformations following overflow of the weir crest. In the present study, two different types of vertical weir, namely broad-crested and sharp-crested, are considered for validation purposes. The calculated overflow parameters such as pressure head distributions, velocity distributions, and water surface profiles are compared against experimental data as well as numerical results available in literature. A very good quantitative agreement has been obtained. The numerical model, thus, offers a good alternative to traditional experimental methods in the study of weir problems.

  8. Level set method for optimal shape design of MRAM core. Micromagnetic approach

    International Nuclear Information System (INIS)

    Melicher, Valdemar; Cimrak, Ivan; Keer, Roger van

    2008-01-01

    We aim at optimizing the shape of the magnetic core in MRAM memories. The evolution of the magnetization during the writing process is described by the Landau-Lifshitz equation (LLE). The actual shape of the core in one cell is characterized by the coefficient γ. Cost functional f=f(γ) expresses the quality of the writing process having in mind the competition between the full-select and the half-select element. We derive an explicit form of the derivative F=∂f/∂γ which allows for the use of gradient-type methods for the actual computation of the optimized shape (e.g., steepest descend method). The level set method (LSM) is employed for the representation of the piecewise constant coefficient γ

  9. Level-set segmentation of pulmonary nodules in megavolt electronic portal images using a CT prior

    International Nuclear Information System (INIS)

    Schildkraut, J. S.; Prosser, N.; Savakis, A.; Gomez, J.; Nazareth, D.; Singh, A. K.; Malhotra, H. K.

    2010-01-01

    Purpose: Pulmonary nodules present unique problems during radiation treatment due to nodule position uncertainty that is caused by respiration. The radiation field has to be enlarged to account for nodule motion during treatment. The purpose of this work is to provide a method of locating a pulmonary nodule in a megavolt portal image that can be used to reduce the internal target volume (ITV) during radiation therapy. A reduction in the ITV would result in a decrease in radiation toxicity to healthy tissue. Methods: Eight patients with nonsmall cell lung cancer were used in this study. CT scans that include the pulmonary nodule were captured with a GE Healthcare LightSpeed RT 16 scanner. Megavolt portal images were acquired with a Varian Trilogy unit equipped with an AS1000 electronic portal imaging device. The nodule localization method uses grayscale morphological filtering and level-set segmentation with a prior. The treatment-time portion of the algorithm is implemented on a graphical processing unit. Results: The method was retrospectively tested on eight cases that include a total of 151 megavolt portal image frames. The method reduced the nodule position uncertainty by an average of 40% for seven out of the eight cases. The treatment phase portion of the method has a subsecond execution time that makes it suitable for near-real-time nodule localization. Conclusions: A method was developed to localize a pulmonary nodule in a megavolt portal image. The method uses the characteristics of the nodule in a prior CT scan to enhance the nodule in the portal image and to identify the nodule region by level-set segmentation. In a retrospective study, the method reduced the nodule position uncertainty by an average of 40% for seven out of the eight cases studied.

  10. GSHR, a Web-Based Platform Provides Gene Set-Level Analyses of Hormone Responses in Arabidopsis

    Directory of Open Access Journals (Sweden)

    Xiaojuan Ran

    2018-01-01

    Full Text Available Phytohormones regulate diverse aspects of plant growth and environmental responses. Recent high-throughput technologies have promoted a more comprehensive profiling of genes regulated by different hormones. However, these omics data generally result in large gene lists that make it challenging to interpret the data and extract insights into biological significance. With the rapid accumulation of theses large-scale experiments, especially the transcriptomic data available in public databases, a means of using this information to explore the transcriptional networks is needed. Different platforms have different architectures and designs, and even similar studies using the same platform may obtain data with large variances because of the highly dynamic and flexible effects of plant hormones; this makes it difficult to make comparisons across different studies and platforms. Here, we present a web server providing gene set-level analyses of Arabidopsis thaliana hormone responses. GSHR collected 333 RNA-seq and 1,205 microarray datasets from the Gene Expression Omnibus, characterizing transcriptomic changes in Arabidopsis in response to phytohormones including abscisic acid, auxin, brassinosteroids, cytokinins, ethylene, gibberellins, jasmonic acid, salicylic acid, and strigolactones. These data were further processed and organized into 1,368 gene sets regulated by different hormones or hormone-related factors. By comparing input gene lists to these gene sets, GSHR helped to identify gene sets from the input gene list regulated by different phytohormones or related factors. Together, GSHR links prior information regarding transcriptomic changes induced by hormones and related factors to newly generated data and facilities cross-study and cross-platform comparisons; this helps facilitate the mining of biologically significant information from large-scale datasets. The GSHR is freely available at http://bioinfo.sibs.ac.cn/GSHR/.

  11. Validation of Mean Absolute Sea Level of the North Atlantic obtained from Drifter, Altimetry and Wind Data

    Science.gov (United States)

    Maximenko, Nikolai A.

    2003-01-01

    Mean absolute sea level reflects the deviation of the Ocean surface from geoid due to the ocean currents and is an important characteristic of the dynamical state of the ocean. Values of its spatial variations (order of 1 m) are generally much smaller than deviations of the geoid shape from ellipsoid (order of 100 m) that makes the derivation of the absolute mean sea level a difficult task for gravity and satellite altimetry observations. Technique used by Niiler et al. for computation of the absolute mean sea level in the Kuroshio Extension was then developed into more general method and applied by Niiler et al. (2003b) to the global Ocean. The method is based on the consideration of balance of horizontal momentum.

  12. Level-set dynamics and mixing efficiency of passive and active scalars in DNS and LES of turbulent mixing layers

    NARCIS (Netherlands)

    Geurts, Bernard J.; Vreman, Bert; Kuerten, Hans; Luo, Kai H.

    2001-01-01

    The mixing efficiency in a turbulent mixing layer is quantified by monitoring the surface-area of level-sets of scalar fields. The Laplace transform is applied to numerically calculate integrals over arbitrary level-sets. The analysis includes both direct and large-eddy simulation and is used to

  13. Very low level α-particle detection by means of pulse shape discrimination

    International Nuclear Information System (INIS)

    Omori, M.

    1993-01-01

    A charge comparison pulse shape discriminator has been shown to be capable of low level alpha particle detection in a NE213 scintillator by discriminating against a high rate of gamma background. The clearly observed alpha peaks were due to 212 Po in 232 Th chain and 214 Po in 238 U chain with rates of 13.5/h and 15.6/h, and energies of 8.95 and 7.83 MeV respectively. For the 8.95 MeV alpha, the gamma background rate was reduced by a factor of 2.1 x 10 4 to a level of 22.5/h. The measurements were made in a low muon flux environment underground (1230 m deep). The detection limit for the alphas could be lowered to as low as 0.1-1 event per day deep underground by use of high purity PSD scintillators. (orig.)

  14. A web-based study of the relationship of duration of insulin pump infusion set use and fasting blood glucose level in adults with type 1 diabetes.

    Science.gov (United States)

    Sampson Perrin, Alysa J; Guzzetta, Russell C; Miller, Kellee M; Foster, Nicole C; Lee, Anna; Lee, Joyce M; Block, Jennifer M; Beck, Roy W

    2015-05-01

    To evaluate the impact of infusion set use duration on glycemic control, we conducted an Internet-based study using the T1D Exchange's online patient community, Glu ( myGlu.org ). For 14 days, 243 electronically consented adults with type 1 diabetes (T1D) entered online that day's fasting blood glucose (FBG) level, the prior day's total daily insulin (TDI) dose, and whether the infusion set was changed. Mean duration of infusion set use was 3.0 days. Mean FBG level was higher with each successive day of infusion set use, increasing from 126 mg/dL on Day 1 to 133 mg/dL on Day 3 to 147 mg/dL on Day 5 (P<0.001). TDI dose did not vary with increased duration of infusion set use. Internet-based data collection was used to rapidly conduct the study at low cost. The results indicate that FBG levels increase with each additional day of insulin pump infusion set use.

  15. Characterization of mammographic masses based on level set segmentation with new image features and patient information

    International Nuclear Information System (INIS)

    Shi Jiazheng; Sahiner, Berkman; Chan Heangping; Ge Jun; Hadjiiski, Lubomir; Helvie, Mark A.; Nees, Alexis; Wu Yita; Wei Jun; Zhou Chuan; Zhang Yiheng; Cui Jing

    2008-01-01

    Computer-aided diagnosis (CAD) for characterization of mammographic masses as malignant or benign has the potential to assist radiologists in reducing the biopsy rate without increasing false negatives. The purpose of this study was to develop an automated method for mammographic mass segmentation and explore new image based features in combination with patient information in order to improve the performance of mass characterization. The authors' previous CAD system, which used the active contour segmentation, and morphological, textural, and spiculation features, has achieved promising results in mass characterization. The new CAD system is based on the level set method and includes two new types of image features related to the presence of microcalcifications with the mass and abruptness of the mass margin, and patient age. A linear discriminant analysis (LDA) classifier with stepwise feature selection was used to merge the extracted features into a classification score. The classification accuracy was evaluated using the area under the receiver operating characteristic curve. The authors' primary data set consisted of 427 biopsy-proven masses (200 malignant and 227 benign) in 909 regions of interest (ROIs) (451 malignant and 458 benign) from multiple mammographic views. Leave-one-case-out resampling was used for training and testing. The new CAD system based on the level set segmentation and the new mammographic feature space achieved a view-based A z value of 0.83±0.01. The improvement compared to the previous CAD system was statistically significant (p=0.02). When patient age was included in the new CAD system, view-based and case-based A z values were 0.85±0.01 and 0.87±0.02, respectively. The study also demonstrated the consistency of the newly developed CAD system by evaluating the statistics of the weights of the LDA classifiers in leave-one-case-out classification. Finally, an independent test on the publicly available digital database for screening

  16. Clinical meanings of determination of serum β-HCG levels in the management of drug abortion for family planning

    International Nuclear Information System (INIS)

    Wang Xianping; Zou Huifeng; Jiang Juping

    2005-01-01

    Objective: To study the clinical meanings of determination of serum β-HCG levels in the management of drug abortion for birth control. Methods: Serum β-HCG levels were determined with CLIA in 254 pregnant women asking for drug abortion and 102 women with ectopic gestation. Results: The serum β-HCG levels in women with normal pregnancy were significantly higher than those in women with ectopic gestation (P 0.05). Conclusion: For drug abortion in those pregnant women with amenorrhea over 45 days and serum β-HCG levels over 50000mlU/ml, a larger dose of misoprostol may be desirable. (authors)

  17. Conditions for settling liquid levels by means of gamma-ray relay control

    Energy Technology Data Exchange (ETDEWEB)

    Wakabayashi, N [Kobe Univ. (Japan). Faculty of Engineering

    1976-03-01

    Using a control action which consists of infusion and exhaust at constant speeds and a neutral zone to maintain liquid levels within a given range, a gamma-ray source, a detector, and two relays at the upper and lower limits of the counting rate were provided. The optimum condition in this case is discussed and confirmed experimentally. Since a counting rate-meter has a time constant and its output is subject to the statistical fluctuation, the liquid level may overrun the opposite limit, move again after settling within the range, or drift far out of the range by a load before actuation of the relay. Formulas are derived providing the conditions such that these phenomena will not occur more frequently than a tolerant probability. These give the relations between the counting rates at the upper and lower limits, the time constant of the rate-meter, the multipliers of the standard deviations of the counting rates, the infusing and exhausting speeds, and the hysteresis widths of the limiting relays. Since it can be said that the first two of the five quantities should be smaller and the next two greater, the optimum condition can be determined from the formulas. When the infusing and exhausting speeds are the same and the hysteresis widths are equal, the formulas show that the optimum is a case where the ratio of the counting rates at the two limits, which is taken smaller than unity, is small, and where each hysteresis width is equal to 0.34 times the difference between the two counting rates, almost regardless of the value of their ratio. The above-mentioned deductions were examined in a system constructed with a backscattered gamma-ray type level gauge and a controller for infusion and exhaust of water. Its results almost agreed with those of the deductions when the multipliers of the standard deviations are substituted for by 2.

  18. Nuclear hyperfine structure of muonium in CuCl resolved by means of avoided level crossing

    International Nuclear Information System (INIS)

    Schneider, J.W.; Celio, M.; Keller, H.; Kuendig, W.; Odermatt, W.; Puempin, B.; Savic, I.M.; Simmler, H.; Estle, T.L.; Schwab, C.; Kiefl, R.F.; Renker, D.

    1990-01-01

    We report detailed avoided-level-crossing spectra of a muonium center (Mu II ) in single-crystal CuCl in a magnetic field range of 4--5 T and at a temperature of 100 K. The hyperfine parameters of the muon and the closest two shells of nuclei indicate that this center consists of muonium at a tetrahedral interstice with four Cu nearest neighbors and six Cl next-nearest neighbors and that the spin density is appreciable on the muon and on the ten neighboring nuclei but negligible elsewhere

  19. A hybrid interface tracking - level set technique for multiphase flow with soluble surfactant

    Science.gov (United States)

    Shin, Seungwon; Chergui, Jalel; Juric, Damir; Kahouadji, Lyes; Matar, Omar K.; Craster, Richard V.

    2018-04-01

    A formulation for soluble surfactant transport in multiphase flows recently presented by Muradoglu and Tryggvason (JCP 274 (2014) 737-757) [17] is adapted to the context of the Level Contour Reconstruction Method, LCRM, (Shin et al. IJNMF 60 (2009) 753-778, [8]) which is a hybrid method that combines the advantages of the Front-tracking and Level Set methods. Particularly close attention is paid to the formulation and numerical implementation of the surface gradients of surfactant concentration and surface tension. Various benchmark tests are performed to demonstrate the accuracy of different elements of the algorithm. To verify surfactant mass conservation, values for surfactant diffusion along the interface are compared with the exact solution for the problem of uniform expansion of a sphere. The numerical implementation of the discontinuous boundary condition for the source term in the bulk concentration is compared with the approximate solution. Surface tension forces are tested for Marangoni drop translation. Our numerical results for drop deformation in simple shear are compared with experiments and results from previous simulations. All benchmarking tests compare well with existing data thus providing confidence that the adapted LCRM formulation for surfactant advection and diffusion is accurate and effective in three-dimensional multiphase flows with a structured mesh. We also demonstrate that this approach applies easily to massively parallel simulations.

  20. Natural setting of Japanese islands and geologic disposal of high-level waste

    International Nuclear Information System (INIS)

    Koide, Hitoshi

    1991-01-01

    The Japanese islands are a combination of arcuate islands along boundaries between four major plates: Eurasia, North America, Pacific and Philippine Sea plates. The interaction among the four plates formed complex geological structures which are basically patchworks of small blocks of land and sea-floor sediments piled up by the subduction of oceanic plates along the margin of the Eurasia continent. Although frequent earthquakes and volcanic eruptions clearly indicate active crustal deformation, the distribution of active faults and volcanoes is localized regionally in the Japanese islands. Crustal displacement faster than 1 mm/year takes place only in restricted regions near plate boundaries or close to major active faults. Volcanic activity is absent in the region between the volcanic front and the subduction zone. The site selection is especially important in Japan. The scenarios for the long-term performance assessment of high-level waste disposal are discussed with special reference to the geological setting of Japan. The long-term prediction of tectonic disturbance, evaluation of faults and fractures in rocks and estimation of long-term water-rock interaction are key issues in the performance assessment of the high-level waste disposal in the Japanese islands. (author)

  1. Relationships between college settings and student alcohol use before, during and after events: a multi-level study.

    Science.gov (United States)

    Paschall, Mallie J; Saltz, Robert F

    2007-11-01

    We examined how alcohol risk is distributed based on college students' drinking before, during and after they go to certain settings. Students attending 14 California public universities (N=10,152) completed a web-based or mailed survey in the fall 2003 semester, which included questions about how many drinks they consumed before, during and after the last time they went to six settings/events: fraternity or sorority party, residence hall party, campus event (e.g. football game), off-campus party, bar/restaurant and outdoor setting (referent). Multi-level analyses were conducted in hierarchical linear modeling (HLM) to examine relationships between type of setting and level of alcohol use before, during and after going to the setting, and possible age and gender differences in these relationships. Drinking episodes (N=24,207) were level 1 units, students were level 2 units and colleges were level 3 units. The highest drinking levels were observed during all settings/events except campus events, with the highest number of drinks being consumed at off-campus parties, followed by residence hall and fraternity/sorority parties. The number of drinks consumed before a fraternity/sorority party was higher than other settings/events. Age group and gender differences in relationships between type of setting/event and 'before,''during' and 'after' drinking levels also were observed. For example, going to a bar/restaurant (relative to an outdoor setting) was positively associated with 'during' drinks among students of legal drinking age while no relationship was observed for underage students. Findings of this study indicate differences in the extent to which college settings are associated with student drinking levels before, during and after related events, and may have implications for intervention strategies targeting different types of settings.

  2. Generalized cost-effectiveness analysis for national-level priority-setting in the health sector

    Directory of Open Access Journals (Sweden)

    Edejer Tessa

    2003-12-01

    Full Text Available Abstract Cost-effectiveness analysis (CEA is potentially an important aid to public health decision-making but, with some notable exceptions, its use and impact at the level of individual countries is limited. A number of potential reasons may account for this, among them technical shortcomings associated with the generation of current economic evidence, political expediency, social preferences and systemic barriers to implementation. As a form of sectoral CEA, Generalized CEA sets out to overcome a number of these barriers to the appropriate use of cost-effectiveness information at the regional and country level. Its application via WHO-CHOICE provides a new economic evidence base, as well as underlying methodological developments, concerning the cost-effectiveness of a range of health interventions for leading causes of, and risk factors for, disease. The estimated sub-regional costs and effects of different interventions provided by WHO-CHOICE can readily be tailored to the specific context of individual countries, for example by adjustment to the quantity and unit prices of intervention inputs (costs or the coverage, efficacy and adherence rates of interventions (effectiveness. The potential usefulness of this information for health policy and planning is in assessing if current intervention strategies represent an efficient use of scarce resources, and which of the potential additional interventions that are not yet implemented, or not implemented fully, should be given priority on the grounds of cost-effectiveness. Health policy-makers and programme managers can use results from WHO-CHOICE as a valuable input into the planning and prioritization of services at national level, as well as a starting point for additional analyses of the trade-off between the efficiency of interventions in producing health and their impact on other key outcomes such as reducing inequalities and improving the health of the poor.

  3. Turning randomness into meaning at the molecular level using Muller's morphs.

    Science.gov (United States)

    Henson, Kathleen; Cooper, Melanie M; Klymkowsky, Michael W

    2012-04-15

    While evolutionary theory follows from observable facts and logical inferences (Mayr, 1985), historically, the origin of novel inheritable variations was a major obstacle to acceptance of natural selection (Bowler, 1992; Bowler, 2005). While molecular mechanisms address this issue (Jablonka and Lamb, 2005), analysis of responses to the Biological Concept Inventory (BCI) (Klymkowsky et al., 2010), revealed that molecular biology majors rarely use molecular level ideas in their discourse, implying that they do not have an accessible framework within which to place evolutionary variation. We developed a "Socratic tutorial" focused on Muller's categorization of mutations' phenotypic effects (Muller, 1932). Using a novel vector-based method to analyzed students' essay responses, we found that a single interaction with this tutorial led to significant changes in thinking toward a clearer articulation of the effects of mutational change. We suggest that Muller's morphs provides an effective framework for facilitating student learning about mutational effects and evolutionary mechanisms.

  4. Turning randomness into meaning at the molecular level using Muller's morphs

    Directory of Open Access Journals (Sweden)

    Kathleen Henson

    2012-02-01

    While evolutionary theory follows from observable facts and logical inferences (Mayr, 1985, historically, the origin of novel inheritable variations was a major obstacle to acceptance of natural selection (Bowler, 1992; Bowler, 2005. While molecular mechanisms address this issue (Jablonka and Lamb, 2005, analysis of responses to the Biological Concept Inventory (BCI (Klymkowsky et al., 2010, revealed that molecular biology majors rarely use molecular level ideas in their discourse, implying that they do not have an accessible framework within which to place evolutionary variation. We developed a “Socratic tutorial” focused on Muller's categorization of mutations' phenotypic effects (Muller, 1932. Using a novel vector-based method to analyzed students' essay responses, we found that a single interaction with this tutorial led to significant changes in thinking toward a clearer articulation of the effects of mutational change. We suggest that Muller's morphs provides an effective framework for facilitating student learning about mutational effects and evolutionary mechanisms.

  5. Personality trait development at the end of life: Antecedents and correlates of mean-level trajectories.

    Science.gov (United States)

    Wagner, Jenny; Ram, Nilam; Smith, Jacqui; Gerstorf, Denis

    2016-09-01

    Empirical evidence over the past 20 years has documented that key aspects of personality traits change during adulthood. However, it is essentially an open question whether and how traits change at the very end of life and what role health, cognitive performance, perceived control, and social factors play in those changes. To examine these questions, we applied growth models to 13-year longitudinal data obtained from now-deceased participants in the Berlin Aging Study (N = 463; age at baseline M = 85.9 years, SD = 8.4; 51% men). Results revealed that neuroticism, on average, increases (about 0.3 SD in the last 10 years) and that this increase becomes even steeper at the end of life. In contrast, extraversion and openness decline rather steadily at the end of life (about -0.5 SD in the last 10 years). Additionally, poor health manifested as a risk factor for declines in extraversion and openness late in life but not neuroticism. Similar to earlier phases of life, better cognitive performance related to more openness. More loneliness was associated with higher neuroticism, whereas more social activity was associated with higher levels of extraversion and openness. Intriguing additional insights indicated that more personal control was associated with higher levels of extraversion and openness, whereas the feeling that one's life is controlled by others was associated with higher neuroticism but also with higher openness closer to death. We discuss potential pathways by which health, cognitive performance, control, and social inclusion resources and risk factors affect personality development late in life. (PsycINFO Database Record (c) 2016 APA, all rights reserved).

  6. HCV carriers with normal aminotransferase levels: “normal” does not always mean “healthy”

    Directory of Open Access Journals (Sweden)

    Claudio Puoti

    2013-04-01

    Full Text Available BACKGROUND Approximately 30% of patients with chronic HCV infection show persistently normal ALT levels (PNALT, and another 40% have minimally raised ALT values. Although formerly referred to as “healthy” or “asymptomatic” HCV carriers, it has now become clear that the majority of these patients have some degree of histological liver damage. Controversies still exist regarding the definition of “persistent” ALT normality, the virological and histological features of these subjects, and the natural history and optimal management of chronic hepatitis C (CHC with normal ALT. Most patients with normal ALT have histologically proven liver damage that may be significant (> F2 in up to 20% of patients, and might progress toward more severe degree of liver fibrosis. A significant proportion of patients (≥ 20% experiences periods of increased serum ALT (flare associated with disease progression. AIM OF THE STUDY The introduction of the new combination therapy of PEG-IFN plus ribavirin allowed response rates higher than 50%, with a favourable risk-benefit ratio also in patients with benign or slow progressive disease. Given the efficacy of the new treatments, which soon became the standard of care for CHC, it has been suggested that the issue of whether or not to treat subjects with PNALT should be re-evaluated. ALT levels may have less importance in deciding who should be treated. Many other factors might influence the decision to treat, such as the age of the patient, HCV genotype, liver histology, patient’s motivation, symptoms, extrahepatic manifestations, comorbid illness. The role of non-invasive tools for the assessment of liver fibrosis (transient hepatic elastography remains to be further validated.

  7. Job satisfaction in nurses working in tertiary level health care settings of Islamabad, Pakistan.

    Science.gov (United States)

    Bahalkani, Habib Akhtar; Kumar, Ramesh; Lakho, Abdul Rehman; Mahar, Benazir; Mazhar, Syeda Batool; Majeed, Abdul

    2011-01-01

    Job satisfaction greatly determines the productivity and efficiency of human resource for health. It literally means: 'the extent to which Health Professionals like or dislike their jobs'. Job satisfaction is said to be linked with employee's work environment, job responsibilities, and powers; and time pressure among various health professionals. As such it affects employee's organizational commitment and consequently the quality of health services. Objective of this study was to determine the level of job satisfaction and factors influencing it among nurses in a public sector hospital of Islamabad. A cross sectional study with self-administered structured questionnaire was conducted in the federal capital of Pakistan, Islamabad. Sample included 56 qualified nurses working in a tertiary care hospital. Overall 86% respondents were dissatisfied with about 26% highly dissatisfied with their job. The work environments, poor fringe benefits, dignity, responsibility given at workplace and time pressure were reason for dissatisfaction. Poor work environment, low salaries, lack of training opportunities, proper supervision, time pressure and financial rewards reported by the respondents. Our findings state a low level of overall satisfaction among workers in a public sector tertiary care health organization in Islamabad. Most of this dissatisfaction is caused by poor salaries, not given the due respect, poor work environment, unbalanced responsibilities with little overall control, time pressure, patient care and lack of opportunities for professional development.

  8. Treatment of low level radioactive wastewater by means of NF process

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Ding; Zhao, Xuan, E-mail: zhxinet@tsinghua.edu.cn; Li, Fuzhi

    2014-10-15

    Highlights: • Nanofiltration can offer one of the approaches in optimizing membrane system. • Operation parameters especially the pressure affect nuclides’ removal efficiency. • Organic polyamide membrane shows radiation resistance. • A summary of DF and flux values can be taken as reference in designing the membrane system for LLRWs treatment. - Abstract: Membrane technology has been proved as an effective technology in the treatment of low level radioactive wastewaters (LLRWs). As ‘loose reverse osmosis’, nanofiltration can be integrated with RO and offers the high permeate flux at low pressure without obvious loss of decontamination efficiency. In the paper, three kinds of commercially available NF membrane materials were investigated by lab-scale experiment with respect to the nuclide rejection. The results demonstrate the efficient elimination. The membrane flux can be improved by the elevation of temperature and cross-flow velocity within the ranges of 20–30 °C and 0.4–1.0 m s{sup −1}. The radiation resistance test demonstrates no obvious loss of flux and nuclide rejection after a long term operation in the radioactive circumstance. A brief comparison of LLRWs treatment methods shows that NF can perform the pre-treatment of RO and optimize the entire membrane system with high flux and low pressure. In the paper, decontamination factor and flux values of the tested membranes at different operation condition are summarized as the reference for membrane selection and system design.

  9. Journal Writing: A Means of Professional Development in ESL Classroom at Undergraduate Level

    Directory of Open Access Journals (Sweden)

    D. Samrajya Lakshmi

    2009-10-01

    Full Text Available The duty of the Teacher of English is not merely teaching English texts but he/she should help the students in enhancing various other skills like communicative, analytical, logical and soft skills. To compete with the growing demands on the English teachers, timely orientation towards professionalism is of dire importance. For over three decades now, it has been found that methodology, training and concept alone will not make a teacher competent enough to train the students at college level to meet the students’ requirements. In this fast changing global scenario, no other processes excepting reflective practice, which is highly exploratory is the best and could serve the ever growing needs of the English language learners and teachers by integrating both theory and practice. This paper focuses on the potential of journal writing as a reflective professional development tool, which is purely a personal low-tech way of incorporating reflective practice in day-to-day classroom teaching by individual teachers. My attempt through this paper is to advertise the use of journal writing not only to the experienced but also to the novice teacher to make his/her class effective.

  10. Mean lives of the 5.106 and 5.834 MeV levels of 14N

    International Nuclear Information System (INIS)

    Bhalla, R.K.; Poletti, A.R.

    1982-01-01

    The recoil distance method (RDM) has been used to measure the mean lives of the 5.106 and 5.834 MeV levels of 14 N as tau = 6.27 +- 0.10 ps and tau = 11.88 +- 0.24 ps respectively. The results are compared to previous measurements and to shell-model calculations. (orig.)

  11. Mean-Level Change and Intraindividual Variability in Self-Esteem and Depression among High-Risk Children

    Science.gov (United States)

    Kim, Jungmeen; Cicchetti, Dante

    2009-01-01

    This study investigated mean-level changes and intraindividual variability of self-esteem among maltreated (N = 142) and nonmaltreated (N = 109) school-aged children from low-income families. Longitudinal factor analysis revealed higher temporal stability of self-esteem among maltreated children compared to nonmaltreated children. Cross-domain…

  12. An improved empirical dynamic control system model of global mean sea level rise and surface temperature change

    Science.gov (United States)

    Wu, Qing; Luu, Quang-Hung; Tkalich, Pavel; Chen, Ge

    2018-04-01

    Having great impacts on human lives, global warming and associated sea level rise are believed to be strongly linked to anthropogenic causes. Statistical approach offers a simple and yet conceptually verifiable combination of remotely connected climate variables and indices, including sea level and surface temperature. We propose an improved statistical reconstruction model based on the empirical dynamic control system by taking into account the climate variability and deriving parameters from Monte Carlo cross-validation random experiments. For the historic data from 1880 to 2001, we yielded higher correlation results compared to those from other dynamic empirical models. The averaged root mean square errors are reduced in both reconstructed fields, namely, the global mean surface temperature (by 24-37%) and the global mean sea level (by 5-25%). Our model is also more robust as it notably diminished the unstable problem associated with varying initial values. Such results suggest that the model not only enhances significantly the global mean reconstructions of temperature and sea level but also may have a potential to improve future projections.

  13. The radioactive contamination level in Croatia by means of radioactive rainwaters, caused by the accident in NPP 'Lenin'

    International Nuclear Information System (INIS)

    Barishicj, D.; Koshuticj, K.; Kvastek, K.; Lulicj, S.; Tuta, J.; Vertachnik, A.; Vrhovac, A.

    1987-01-01

    In this paper, the radioactive contamination level in Croatia by means of radioactive rainwaters, caused by the accident in NPP 'Lenin', has been described. The results represent the sum of measured and evaluated data, the map of the radioactive contamination in Croatia caused by radioactive rainwaters between April, 28 to May, 20 1986 has been constructed. (author) 3 tabs.; 5 figs

  14. Home advantage in high-level volleyball varies according to set number.

    Science.gov (United States)

    Marcelino, Rui; Mesquita, Isabel; Palao Andrés, José Manuel; Sampaio, Jaime

    2009-01-01

    The aim of the present study was to identify the probability of winning each Volleyball set according to game location (home, away). Archival data was obtained from 275 sets in the 2005 Men's Senior World League and 65,949 actions were analysed. Set result (win, loss), game location (home, away), set number (first, second, third, fourth and fifth) and performance indicators (serve, reception, set, attack, dig and block) were the variables considered in this study. In a first moment, performance indicators were used in a logistic model of set result, by binary logistic regression analysis. After finding the adjusted logistic model, the log-odds of winning the set were analysed according to game location and set number. The results showed that winning a set is significantly related to performance indicators (Chisquare(18)=660.97, padvantage at the beginning of the game (first set) and in the two last sets of the game (fourth and fifth sets), probably due to facilities familiarity and crowd effects. Different game actions explain these advantages and showed that to win the first set is more important to take risk, through a better performance in the attack and block, and to win the final set is important to manage the risk through a better performance on the reception. These results may suggest intra-game variation in home advantage and can be most useful to better prepare and direct the competition. Key pointsHome teams always have more probability of winning the game than away teams.Home teams have higher performance in reception, set and attack in the total of the sets.The advantage of home teams is more pronounced at the beginning of the game (first set) and in two last sets of the game (fourth and fifth sets) suggesting intra-game variation in home advantage.Analysis by sets showed that home teams have a better performance in the attack and block in the first set and in the reception in the third and fifth sets.

  15. On the modeling of bubble evolution and transport using coupled level-set/CFD method

    International Nuclear Information System (INIS)

    Bartlomiej Wierzbicki; Steven P Antal; Michael Z Podowski

    2005-01-01

    Full text of publication follows: The ability to predict the shape of the gas/liquid/solid interfaces is important for various multiphase flow and heat transfer applications. Specific issues of interest to nuclear reactor thermal-hydraulics, include the evolution of the shape of bubbles attached to solid surfaces during nucleation, bubble surface interactions in complex geometries, etc. Additional problems, making the overall task even more complicated, are associated with the effect of material properties that may be significantly altered by the addition of minute amounts of impurities, such as surfactants or nano-particles. The present paper is concerned with the development of an innovative approach to model time-dependent shape of gas/liquid interfaces in the presence of solid walls. The proposed approach combines a modified level-set method with an advanced CFD code, NPHASE. The coupled numerical solver can be used to simulate the evolution of gas/liquid interfaces in two-phase flows for a variety of geometries and flow conditions, from individual bubbles to free surfaces (stratified flows). The issues discussed in the full paper will include: a description of the novel aspects of the proposed level-set concept based method, an overview of the NPHASE code modeling framework and a description of the coupling method between these two elements of the overall model. A particular attention will be give to the consistency and completeness of model formulation for the interfacial phenomena near the liquid/gas/solid triple line, and to the impact of the proposed numerical approach on the accuracy and consistency of predictions. The accuracy will be measured in terms of both the calculated shape of the interfaces and the gas and liquid velocity fields around the interfaces and in the entire computational domain. The results of model testing and validation will also be shown in the full paper. The situations analyzed will include: bubbles of different sizes and varying

  16. Evaluation of two-phase flow solvers using Level Set and Volume of Fluid methods

    Science.gov (United States)

    Bilger, C.; Aboukhedr, M.; Vogiatzaki, K.; Cant, R. S.

    2017-09-01

    Two principal methods have been used to simulate the evolution of two-phase immiscible flows of liquid and gas separated by an interface. These are the Level-Set (LS) method and the Volume of Fluid (VoF) method. Both methods attempt to represent the very sharp interface between the phases and to deal with the large jumps in physical properties associated with it. Both methods have their own strengths and weaknesses. For example, the VoF method is known to be prone to excessive numerical diffusion, while the basic LS method has some difficulty in conserving mass. Major progress has been made in remedying these deficiencies, and both methods have now reached a high level of physical accuracy. Nevertheless, there remains an issue, in that each of these methods has been developed by different research groups, using different codes and most importantly the implementations have been fine tuned to tackle different applications. Thus, it remains unclear what are the remaining advantages and drawbacks of each method relative to the other, and what might be the optimal way to unify them. In this paper, we address this gap by performing a direct comparison of two current state-of-the-art variations of these methods (LS: RCLSFoam and VoF: interPore) and implemented in the same code (OpenFoam). We subject both methods to a pair of benchmark test cases while using the same numerical meshes to examine a) the accuracy of curvature representation, b) the effect of tuning parameters, c) the ability to minimise spurious velocities and d) the ability to tackle fluids with very different densities. For each method, one of the test cases is chosen to be fairly benign while the other test case is expected to present a greater challenge. The results indicate that both methods can be made to work well on both test cases, while displaying different sensitivity to the relevant parameters.

  17. Patient- and population-level health consequences of discontinuing antiretroviral therapy in settings with inadequate HIV treatment availability

    Directory of Open Access Journals (Sweden)

    Kimmel April D

    2012-09-01

    Full Text Available Abstract Background In resource-limited settings, HIV budgets are flattening or decreasing. A policy of discontinuing antiretroviral therapy (ART after HIV treatment failure was modeled to highlight trade-offs among competing policy goals of optimizing individual and population health outcomes. Methods In settings with two available ART regimens, we assessed two strategies: (1 continue ART after second-line failure (Status Quo and (2 discontinue ART after second-line failure (Alternative. A computer model simulated outcomes for a single cohort of newly detected, HIV-infected individuals. Projections were fed into a population-level model allowing multiple cohorts to compete for ART with constraints on treatment capacity. In the Alternative strategy, discontinuation of second-line ART occurred upon detection of antiretroviral failure, specified by WHO guidelines. Those discontinuing failed ART experienced an increased risk of AIDS-related mortality compared to those continuing ART. Results At the population level, the Alternative strategy increased the mean number initiating ART annually by 1,100 individuals (+18.7% to 6,980 compared to the Status Quo. More individuals initiating ART under the Alternative strategy increased total life-years by 15,000 (+2.8% to 555,000, compared to the Status Quo. Although more individuals received treatment under the Alternative strategy, life expectancy for those treated decreased by 0.7 years (−8.0% to 8.1 years compared to the Status Quo. In a cohort of treated patients only, 600 more individuals (+27.1% died by 5 years under the Alternative strategy compared to the Status Quo. Results were sensitive to the timing of detection of ART failure, number of ART regimens, and treatment capacity. Although we believe the results robust in the short-term, this analysis reflects settings where HIV case detection occurs late in the disease course and treatment capacity and the incidence of newly detected patients are

  18. [Cardiac Synchronization Function Estimation Based on ASM Level Set Segmentation Method].

    Science.gov (United States)

    Zhang, Yaonan; Gao, Yuan; Tang, Liang; He, Ying; Zhang, Huie

    At present, there is no accurate and quantitative methods for the determination of cardiac mechanical synchronism, and quantitative determination of the synchronization function of the four cardiac cavities with medical images has a great clinical value. This paper uses the whole heart ultrasound image sequence, and segments the left & right atriums and left & right ventricles of each frame. After the segmentation, the number of pixels in each cavity and in each frame is recorded, and the areas of the four cavities of the image sequence are therefore obtained. The area change curves of the four cavities are further extracted, and the synchronous information of the four cavities is obtained. Because of the low SNR of Ultrasound images, the boundary lines of cardiac cavities are vague, so the extraction of cardiac contours is still a challenging problem. Therefore, the ASM model information is added to the traditional level set method to force the curve evolution process. According to the experimental results, the improved method improves the accuracy of the segmentation. Furthermore, based on the ventricular segmentation, the right and left ventricular systolic functions are evaluated, mainly according to the area changes. The synchronization of the four cavities of the heart is estimated based on the area changes and the volume changes.

  19. An integrated extended Kalman filter–implicit level set algorithm for monitoring planar hydraulic fractures

    International Nuclear Information System (INIS)

    Peirce, A; Rochinha, F

    2012-01-01

    We describe a novel approach to the inversion of elasto-static tiltmeter measurements to monitor planar hydraulic fractures propagating within three-dimensional elastic media. The technique combines the extended Kalman filter (EKF), which predicts and updates state estimates using tiltmeter measurement time-series, with a novel implicit level set algorithm (ILSA), which solves the coupled elasto-hydrodynamic equations. The EKF and ILSA are integrated to produce an algorithm to locate the unknown fracture-free boundary. A scaling argument is used to derive a strategy to tune the algorithm parameters to enable measurement information to compensate for unmodeled dynamics. Synthetic tiltmeter data for three numerical experiments are generated by introducing significant changes to the fracture geometry by altering the confining geological stress field. Even though there is no confining stress field in the dynamic model used by the new EKF-ILSA scheme, it is able to use synthetic data to arrive at remarkably accurate predictions of the fracture widths and footprints. These experiments also explore the robustness of the algorithm to noise and to placement of tiltmeter arrays operating in the near-field and far-field regimes. In these experiments, the appropriate parameter choices and strategies to improve the robustness of the algorithm to significant measurement noise are explored. (paper)

  20. Automatic Fontanel Extraction from Newborns' CT Images Using Variational Level Set

    Science.gov (United States)

    Kazemi, Kamran; Ghadimi, Sona; Lyaghat, Alireza; Tarighati, Alla; Golshaeyan, Narjes; Abrishami-Moghaddam, Hamid; Grebe, Reinhard; Gondary-Jouet, Catherine; Wallois, Fabrice

    A realistic head model is needed for source localization methods used for the study of epilepsy in neonates applying Electroencephalographic (EEG) measurements from the scalp. The earliest models consider the head as a series of concentric spheres, each layer corresponding to a different tissue whose conductivity is assumed to be homogeneous. The results of the source reconstruction depend highly on the electric conductivities of the tissues forming the head.The most used model is constituted of three layers (scalp, skull, and intracranial). Most of the major bones of the neonates’ skull are ossified at birth but can slightly move relative to each other. This is due to the sutures, fibrous membranes that at this stage of development connect the already ossified flat bones of the neurocranium. These weak parts of the neurocranium are called fontanels. Thus it is important to enter the exact geometry of fontaneles and flat bone in a source reconstruction because they show pronounced in conductivity. Computer Tomography (CT) imaging provides an excellent tool for non-invasive investigation of the skull which expresses itself in high contrast to all other tissues while the fontanels only can be identified as absence of bone, gaps in the skull formed by flat bone. Therefore, the aim of this paper is to extract the fontanels from CT images applying a variational level set method. We applied the proposed method to CT-images of five different subjects. The automatically extracted fontanels show good agreement with the manually extracted ones.

  1. Two-phase electro-hydrodynamic flow modeling by a conservative level set model.

    Science.gov (United States)

    Lin, Yuan

    2013-03-01

    The principles of electro-hydrodynamic (EHD) flow have been known for more than a century and have been adopted for various industrial applications, for example, fluid mixing and demixing. Analytical solutions of such EHD flow only exist in a limited number of scenarios, for example, predicting a small deformation of a single droplet in a uniform electric field. Numerical modeling of such phenomena can provide significant insights about EHDs multiphase flows. During the last decade, many numerical results have been reported to provide novel and useful tools of studying the multiphase EHD flow. Based on a conservative level set method, the proposed model is able to simulate large deformations of a droplet by a steady electric field, which is beyond the region of theoretic prediction. The model is validated for both leaky dielectrics and perfect dielectrics, and is found to be in excellent agreement with existing analytical solutions and numerical studies in the literature. Furthermore, simulations of the deformation of a water droplet in decyl alcohol in a steady electric field match better with published experimental data than the theoretical prediction for large deformations. Therefore the proposed model can serve as a practical and accurate tool for simulating two-phase EHD flow. © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  2. Modeling of Two-Phase Flow in Rough-Walled Fracture Using Level Set Method

    Directory of Open Access Journals (Sweden)

    Yunfeng Dai

    2017-01-01

    Full Text Available To describe accurately the flow characteristic of fracture scale displacements of immiscible fluids, an incompressible two-phase (crude oil and water flow model incorporating interfacial forces and nonzero contact angles is developed. The roughness of the two-dimensional synthetic rough-walled fractures is controlled with different fractal dimension parameters. Described by the Navier–Stokes equations, the moving interface between crude oil and water is tracked using level set method. The method accounts for differences in densities and viscosities of crude oil and water and includes the effect of interfacial force. The wettability of the rough fracture wall is taken into account by defining the contact angle and slip length. The curve of the invasion pressure-water volume fraction is generated by modeling two-phase flow during a sudden drainage. The volume fraction of water restricted in the rough-walled fracture is calculated by integrating the water volume and dividing by the total cavity volume of the fracture while the two-phase flow is quasistatic. The effect of invasion pressure of crude oil, roughness of fracture wall, and wettability of the wall on two-phase flow in rough-walled fracture is evaluated.

  3. Tokunaga and Horton self-similarity for level set trees of Markov chains

    International Nuclear Information System (INIS)

    Zaliapin, Ilia; Kovchegov, Yevgeniy

    2012-01-01

    Highlights: ► Self-similar properties of the level set trees for Markov chains are studied. ► Tokunaga and Horton self-similarity are established for symmetric Markov chains and regular Brownian motion. ► Strong, distributional self-similarity is established for symmetric Markov chains with exponential jumps. ► It is conjectured that fractional Brownian motions are Tokunaga self-similar. - Abstract: The Horton and Tokunaga branching laws provide a convenient framework for studying self-similarity in random trees. The Horton self-similarity is a weaker property that addresses the principal branching in a tree; it is a counterpart of the power-law size distribution for elements of a branching system. The stronger Tokunaga self-similarity addresses so-called side branching. The Horton and Tokunaga self-similarity have been empirically established in numerous observed and modeled systems, and proven for two paradigmatic models: the critical Galton–Watson branching process with finite progeny and the finite-tree representation of a regular Brownian excursion. This study establishes the Tokunaga and Horton self-similarity for a tree representation of a finite symmetric homogeneous Markov chain. We also extend the concept of Horton and Tokunaga self-similarity to infinite trees and establish self-similarity for an infinite-tree representation of a regular Brownian motion. We conjecture that fractional Brownian motions are also Tokunaga and Horton self-similar, with self-similarity parameters depending on the Hurst exponent.

  4. Delineating Facies Spatial Distribution by Integrating Ensemble Data Assimilation and Indicator Geostatistics with Level Set Transformation.

    Energy Technology Data Exchange (ETDEWEB)

    Hammond, Glenn Edward; Song, Xuehang; Ye, Ming; Dai, Zhenxue; Zachara, John; Chen, Xingyuan

    2017-03-01

    A new approach is developed to delineate the spatial distribution of discrete facies (geological units that have unique distributions of hydraulic, physical, and/or chemical properties) conditioned not only on direct data (measurements directly related to facies properties, e.g., grain size distribution obtained from borehole samples) but also on indirect data (observations indirectly related to facies distribution, e.g., hydraulic head and tracer concentration). Our method integrates for the first time ensemble data assimilation with traditional transition probability-based geostatistics. The concept of level set is introduced to build shape parameterization that allows transformation between discrete facies indicators and continuous random variables. The spatial structure of different facies is simulated by indicator models using conditioning points selected adaptively during the iterative process of data assimilation. To evaluate the new method, a two-dimensional semi-synthetic example is designed to estimate the spatial distribution and permeability of two distinct facies from transient head data induced by pumping tests. The example demonstrates that our new method adequately captures the spatial pattern of facies distribution by imposing spatial continuity through conditioning points. The new method also reproduces the overall response in hydraulic head field with better accuracy compared to data assimilation with no constraints on spatial continuity on facies.

  5. Measurement of thermally ablated lesions in sonoelastographic images using level set methods

    Science.gov (United States)

    Castaneda, Benjamin; Tamez-Pena, Jose Gerardo; Zhang, Man; Hoyt, Kenneth; Bylund, Kevin; Christensen, Jared; Saad, Wael; Strang, John; Rubens, Deborah J.; Parker, Kevin J.

    2008-03-01

    The capability of sonoelastography to detect lesions based on elasticity contrast can be applied to monitor the creation of thermally ablated lesion. Currently, segmentation of lesions depicted in sonoelastographic images is performed manually which can be a time consuming process and prone to significant intra- and inter-observer variability. This work presents a semi-automated segmentation algorithm for sonoelastographic data. The user starts by planting a seed in the perceived center of the lesion. Fast marching methods use this information to create an initial estimate of the lesion. Subsequently, level set methods refine its final shape by attaching the segmented contour to edges in the image while maintaining smoothness. The algorithm is applied to in vivo sonoelastographic images from twenty five thermal ablated lesions created in porcine livers. The estimated area is compared to results from manual segmentation and gross pathology images. Results show that the algorithm outperforms manual segmentation in accuracy, inter- and intra-observer variability. The processing time per image is significantly reduced.

  6. Flipping for success: evaluating the effectiveness of a novel teaching approach in a graduate level setting.

    Science.gov (United States)

    Moraros, John; Islam, Adiba; Yu, Stan; Banow, Ryan; Schindelka, Barbara

    2015-02-28

    opportunities based on problem-solving activities and offer timely feedback/guidance to students. Yet in our study, this teaching style had its fair share of challenges, which were largely dependent on the use and management of technology. Despite these challenges, the Flipped Classroom proved to be a novel and effective teaching approach at the graduate level setting.

  7. Revisiting global mean sea level budget closure : Preliminary results from an integrative study within ESA's Climate Change Initiative -Sea level Budget Closure-Climate Change Initiative

    Science.gov (United States)

    Palanisamy, H.; Cazenave, A. A.

    2017-12-01

    The global mean sea level budget is revisited over two time periods: the entire altimetry era, 1993-2015 and the Argo/GRACE era, 2003-2015 using the version '0' of sea level components estimated by the SLBC-CCI teams. The SLBC-CCI is an European Space Agency's project on sea level budget closure using CCI products. Over the entire altimetry era, the sea level budget was performed as the sum of steric and mass components that include contributions from total land water storage, glaciers, ice sheets (Greenland and Antarctica) and total water vapor content. Over the Argo/GRACE era, it was performed as the sum of steric and GRACE based ocean mass. Preliminary budget analysis performed over the altimetry era (1993-2015) results in a trend value of 2.83 mm/yr. On comparison with the observed altimetry-based global mean sea level trend over the same period (3.03 ± 0.5 mm/yr), we obtain a residual of 0.2 mm/yr. In spite of a residual of 0.2 mm/yr, the sea level budget result obtained over the altimetry era is very promising as this has been performed using the version '0' of the sea level components. Furthermore, uncertainties are not yet included in this study as uncertainty estimation for each sea level component is currently underway. Over the Argo/GRACE era (2003-2015), the trend estimated from the sum of steric and GRACE ocean mass amounts to 2.63 mm/yr while that observed by satellite altimetry is 3.37 mm/yr, thereby leaving a residual of 0.7 mm/yr. Here an ensemble GRACE ocean mass data (mean of various available GRACE ocean mass data) was used for the estimation. Using individual GRACE data results in a residual range of 0.5 mm/yr -1.1 mm/yr. Investigations are under way to determine the cause of the vast difference between the observed sea level and the sea level obtained from steric and GRACE ocean mass. One main suspect is the impact of GRACE data gaps on sea level budget analysis due to lack of GRACE data over several months since 2011. The current action plan

  8. DESIRE FOR LEVELS. Background study for the policy document "Setting Environmental Quality Standards for Water and Soil"

    NARCIS (Netherlands)

    van de Meent D; Aldenberg T; Canton JH; van Gestel CAM; Slooff W

    1990-01-01

    The report provides scientific support for setting environmental quality objectives for water, sediment and soil. Quality criteria are not set in this report. Only options for decisions are given. The report is restricted to the derivation of the 'maximally acceptable risk' levels (MAR)

  9. Multiatlas segmentation of thoracic and abdominal anatomy with level set-based local search.

    Science.gov (United States)

    Schreibmann, Eduard; Marcus, David M; Fox, Tim

    2014-07-08

    Segmentation of organs at risk (OARs) remains one of the most time-consuming tasks in radiotherapy treatment planning. Atlas-based segmentation methods using single templates have emerged as a practical approach to automate the process for brain or head and neck anatomy, but pose significant challenges in regions where large interpatient variations are present. We show that significant changes are needed to autosegment thoracic and abdominal datasets by combining multi-atlas deformable registration with a level set-based local search. Segmentation is hierarchical, with a first stage detecting bulk organ location, and a second step adapting the segmentation to fine details present in the patient scan. The first stage is based on warping multiple presegmented templates to the new patient anatomy using a multimodality deformable registration algorithm able to cope with changes in scanning conditions and artifacts. These segmentations are compacted in a probabilistic map of organ shape using the STAPLE algorithm. Final segmentation is obtained by adjusting the probability map for each organ type, using customized combinations of delineation filters exploiting prior knowledge of organ characteristics. Validation is performed by comparing automated and manual segmentation using the Dice coefficient, measured at an average of 0.971 for the aorta, 0.869 for the trachea, 0.958 for the lungs, 0.788 for the heart, 0.912 for the liver, 0.884 for the kidneys, 0.888 for the vertebrae, 0.863 for the spleen, and 0.740 for the spinal cord. Accurate atlas segmentation for abdominal and thoracic regions can be achieved with the usage of a multi-atlas and perstructure refinement strategy. To improve clinical workflow and efficiency, the algorithm was embedded in a software service, applying the algorithm automatically on acquired scans without any user interaction.

  10. Sensitivity Analysis of features in tolerancing based on constraint function level sets

    International Nuclear Information System (INIS)

    Ziegler, Philipp; Wartzack, Sandro

    2015-01-01

    Usually, the geometry of the manufactured product inherently varies from the nominal geometry. This may negatively affect the product functions and properties (such as quality and reliability), as well as the assemblability of the single components. In order to avoid this, the geometric variation of these component surfaces and associated geometry elements (like hole axes) are restricted by tolerances. Since tighter tolerances lead to significant higher manufacturing costs, tolerances should be specified carefully. Therefore, the impact of deviating component surfaces on functions, properties and assemblability of the product has to be analyzed. As physical experiments are expensive, methods of statistical tolerance analysis tools are widely used in engineering design. Current tolerance simulation tools lack of an appropriate indicator for the impact of deviating component surfaces. In the adoption of Sensitivity Analysis methods, there are several challenges, which arise from the specific framework in tolerancing. This paper presents an approach to adopt Sensitivity Analysis methods on current tolerance simulations with an interface module, which bases on level sets of constraint functions for parameters of the simulation model. The paper is an extension and generalization of Ziegler and Wartzack [1]. Mathematical properties of the constraint functions (convexity, homogeneity), which are important for the computational costs of the Sensitivity Analysis, are shown. The practical use of the method is illustrated in a case study of a plain bearing. - Highlights: • Alternative definition of Deviation Domains. • Proof of mathematical properties of the Deviation Domains. • Definition of the interface between Deviation Domains and Sensitivity Analysis. • Sensitivity analysis of a gearbox to show the methods practical use

  11. Shape Reconstruction of Thin Electromagnetic Inclusions via Boundary Measurements: Level-Set Method Combined with the Topological Derivative

    Directory of Open Access Journals (Sweden)

    Won-Kwang Park

    2013-01-01

    Full Text Available An inverse problem for reconstructing arbitrary-shaped thin penetrable electromagnetic inclusions concealed in a homogeneous material is considered in this paper. For this purpose, the level-set evolution method is adopted. The topological derivative concept is incorporated in order to evaluate the evolution speed of the level-set functions. The results of the corresponding numerical simulations with and without noise are presented in this paper.

  12. High Levels of Post-Abortion Complication in a Setting Where Abortion Service Is Not Legalized

    Science.gov (United States)

    Melese, Tadele; Habte, Dereje; Tsima, Billy M.; Mogobe, Keitshokile Dintle; Chabaesele, Kesegofetse; Rankgoane, Goabaone; Keakabetse, Tshiamo R.; Masweu, Mabole; Mokotedi, Mosidi; Motana, Mpho; Moreri-Ntshabele, Badani

    2017-01-01

    Background Maternal mortality due to abortion complications stands among the three leading causes of maternal death in Botswana where there is a restrictive abortion law. This study aimed at assessing the patterns and determinants of post-abortion complications. Methods A retrospective institution based cross-sectional study was conducted at four hospitals from January to August 2014. Data were extracted from patients’ records with regards to their socio-demographic variables, abortion complications and length of hospital stay. Descriptive statistics and bivariate analysis were employed. Result A total of 619 patients’ records were reviewed with a mean (SD) age of 27.12 (5.97) years. The majority of abortions (95.5%) were reported to be spontaneous and 3.9% of the abortions were induced by the patient. Two thirds of the patients were admitted as their first visit to the hospitals and one third were referrals from other health facilities. Two thirds of the patients were admitted as a result of incomplete abortion followed by inevitable abortion (16.8%). Offensive vaginal discharge (17.9%), tender uterus (11.3%), septic shock (3.9%) and pelvic peritonitis (2.4%) were among the physical findings recorded on admission. Clinically detectable anaemia evidenced by pallor was found to be the leading major complication in 193 (31.2%) of the cases followed by hypovolemic and septic shock 65 (10.5%). There were a total of 9 abortion related deaths with a case fatality rate of 1.5%. Self-induced abortion and delayed uterine evacuation of more than six hours were found to have significant association with post-abortion complications (p-values of 0.018 and 0.035 respectively). Conclusion Abortion related complications and deaths are high in our setting where abortion is illegal. Mechanisms need to be devised in the health facilities to evacuate the uterus in good time whenever it is indicated and to be equipped to handle the fatal complications. There is an indication for

  13. High Levels of Post-Abortion Complication in a Setting Where Abortion Service Is Not Legalized.

    Directory of Open Access Journals (Sweden)

    Tadele Melese

    Full Text Available Maternal mortality due to abortion complications stands among the three leading causes of maternal death in Botswana where there is a restrictive abortion law. This study aimed at assessing the patterns and determinants of post-abortion complications.A retrospective institution based cross-sectional study was conducted at four hospitals from January to August 2014. Data were extracted from patients' records with regards to their socio-demographic variables, abortion complications and length of hospital stay. Descriptive statistics and bivariate analysis were employed.A total of 619 patients' records were reviewed with a mean (SD age of 27.12 (5.97 years. The majority of abortions (95.5% were reported to be spontaneous and 3.9% of the abortions were induced by the patient. Two thirds of the patients were admitted as their first visit to the hospitals and one third were referrals from other health facilities. Two thirds of the patients were admitted as a result of incomplete abortion followed by inevitable abortion (16.8%. Offensive vaginal discharge (17.9%, tender uterus (11.3%, septic shock (3.9% and pelvic peritonitis (2.4% were among the physical findings recorded on admission. Clinically detectable anaemia evidenced by pallor was found to be the leading major complication in 193 (31.2% of the cases followed by hypovolemic and septic shock 65 (10.5%. There were a total of 9 abortion related deaths with a case fatality rate of 1.5%. Self-induced abortion and delayed uterine evacuation of more than six hours were found to have significant association with post-abortion complications (p-values of 0.018 and 0.035 respectively.Abortion related complications and deaths are high in our setting where abortion is illegal. Mechanisms need to be devised in the health facilities to evacuate the uterus in good time whenever it is indicated and to be equipped to handle the fatal complications. There is an indication for clinical audit on post-abortion care

  14. Improving district level health planning and priority setting in Tanzania through implementing accountability for reasonableness framework

    DEFF Research Database (Denmark)

    Maluka, Stephen; Kamuzora, Peter; Sebastián, Miguel San

    2010-01-01

    In 2006, researchers and decision-makers launched a five-year project - Response to Accountable Priority Setting for Trust in Health Systems (REACT) - to improve planning and priority-setting through implementing the Accountability for Reasonableness framework in Mbarali District, Tanzania...

  15. Personality traits in old age: measurement and rank-order stability and some mean-level change.

    Science.gov (United States)

    Mõttus, René; Johnson, Wendy; Deary, Ian J

    2012-03-01

    Lothian Birth Cohorts, 1936 and 1921 were used to study the longitudinal comparability of Five-Factor Model (McCrae & John, 1992) personality traits from ages 69 to 72 years and from ages 81 to 87 years, and cross-cohort comparability between ages 69 and 81 years. Personality was measured using the 50-item International Personality Item Pool (Goldberg, 1999). Satisfactory measurement invariance was established across time and cohorts. High rank-order stability was observed in both cohorts. Almost no mean-level change was observed in the younger cohort, whereas Extraversion, Agreeableness, Conscientiousness, and Intellect declined significantly in the older cohort. The older cohort scored higher on Agreeableness and Conscientiousness. In these cohorts, individual differences in personality traits continued to be stable even in very old age, mean-level changes accelerated.

  16. Mean sea level and change in the hydrological regime off Loviisa power plant around the year 2050

    International Nuclear Information System (INIS)

    Maelkki, P.; Voipio, A.

    1985-03-01

    On the request of Imatran Voima Oy, the Institute of Marine Research has made an estimate on the future sea level off Loviisa Power Plant. The estimate is based on observationsof mean sea level in the Gulf of Finland. The stations used are Helsinki (observations since 1904) and Hamina (observations since 1928). A litterature review was made in order to estimate impact of climate change on environmental conditions. The results presented are mainly based on various estimates of meterorological Global Circulation Models (GCM). Their usefulness in the connection is briefly discussed

  17. A finite element/level set model of polyurethane foam expansion and polymerization

    Energy Technology Data Exchange (ETDEWEB)

    Rao, Rekha R. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Long, Kevin Nicholas [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Roberts, Christine Cardinal [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Celina, Mathias C. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Brunini, Victor [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Soehnel, Melissa Marie [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Noble, David R. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Tinsley, James [Honeywell Federal Manufacturing & Technologies, Kansas City, MO (United States); Mondy, Lisa [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

    2017-12-01

    Polyurethane foams are used widely for encapsulation and structural purposes because they are inexpensive, straightforward to process, amenable to a wide range of density variations (1 lb/ft3 - 50 lb/ft3), and able to fill complex molds quickly and effectively. Computational model of the filling and curing process are needed to reduce defects such as voids, out-of-specification density, density gradients, foam decomposition from high temperatures due to exotherms, and incomplete filling. This paper details the development of a computational fluid dynamics model of a moderate density PMDI structural foam, PMDI-10. PMDI is an isocyanate-based polyurethane foam, which is chemically blown with water. The polyol reacts with isocyanate to produces the polymer. PMDI- 10 is catalyzed giving it a short pot life: it foams and polymerizes to a solid within 5 minutes during normal processing. To achieve a higher density, the foam is over-packed to twice or more of its free rise density of 10 lb/ft3. The goal for modeling is to represent the expansion, filling of molds, and the polymerization of the foam. This will be used to reduce defects, optimize the mold design, troubleshoot the processed, and predict the final foam properties. A homogenized continuum model foaming and curing was developed based on reaction kinetics, documented in a recent paper; it uses a simplified mathematical formalism that decouples these two reactions. The chemo-rheology of PMDI is measured experimentally and fit to a generalized- Newtonian viscosity model that is dependent on the extent of cure, gas fraction, and temperature. The conservation equations, including the equations of motion, an energy balance, and three rate equations are solved via a stabilized finite element method. The equations are combined with a level set method to determine the location of the foam-gas interface as it evolves to fill the mold. Understanding the thermal history and loads on the foam due to exothermicity and oven

  18. Strengthening fairness, transparency and accountability in health care priority setting at district level in Tanzania

    Directory of Open Access Journals (Sweden)

    Stephen Maluka

    2011-11-01

    Full Text Available Health care systems are faced with the challenge of resource scarcity and have insufficient resources to respond to all health problems and target groups simultaneously. Hence, priority setting is an inevitable aspect of every health system. However, priority setting is complex and difficult because the process is frequently influenced by political, institutional and managerial factors that are not considered by conventional priority-setting tools. In a five-year EU-supported project, which started in 2006, ways of strengthening fairness and accountability in priority setting in district health management were studied. This review is based on a PhD thesis that aimed to analyse health care organisation and management systems, and explore the potential and challenges of implementing Accountability for Reasonableness (A4R approach to priority setting in Tanzania. A qualitative case study in Mbarali district formed the basis of exploring the sociopolitical and institutional contexts within which health care decision making takes place. The study also explores how the A4R intervention was shaped, enabled and constrained by the contexts. Key informant interviews were conducted. Relevant documents were also gathered and group priority-setting processes in the district were observed. The study revealed that, despite the obvious national rhetoric on decentralisation, actual practice in the district involved little community participation. The assumption that devolution to local government promotes transparency, accountability and community participation, is far from reality. The study also found that while the A4R approach was perceived to be helpful in strengthening transparency, accountability and stakeholder engagement, integrating the innovation into the district health system was challenging. This study underscores the idea that greater involvement and accountability among local actors may increase the legitimacy and fairness of priority-setting

  19. Comparisons of different mean airway pressure settings during high-frequency oscillation in inflammatory response to oleic acid-induced lung injury in rabbits

    Directory of Open Access Journals (Sweden)

    Koichi Ono

    2009-03-01

    Full Text Available Koichi Ono1, Tomonobu Koizumi2, Rikimaru Nakagawa1, Sumiko Yoshikawa2, Tetsutarou Otagiri11Department of Anesthesiology and Resuscitation; 2First Department of Internal Medicine, Shinshu University School of Medicine, Matsumoto, JapanPurpose: The present study was designed to examine effects of different mean airway pressure (MAP settings during high-frequency oscillation (HFO on oxygenation and inflammatory responses to acute lung injury (ALI in rabbits.Methods: Anesthetized rabbits were mechanically ventilated with a conventional mechanical ventilation (CMV mode (tidal volume 6 ml/kg, inspired oxygen fraction [FIo2] of 1.0, respiratory rate [RR] of 30/min, positive end-expiratory pressure [PEEP] of 5 cmH2O. ALI was induced by intravenous administration of oleic acid (0.08 ml/kg and the animals were randomly allocated to the following three experimental groups; animals (n = 6 ventilated using the same mode of CMV, or animals ventilated with standard MAP (MAP 10 cmH2O, n = 7, and high MAP (15 cmH2O, n = 6 settings of HFO (Hz 15. The MAP settings were calculated by the inflation limb of the pressure-volume curve during CMV.Results: HFO with a high MAP setting significantly improved the deteriorated oxygenation during oleic acid-induced ALI and reduced wet/dry ratios, neutrophil counts and interleukin-8 concentration in bronchoalveolar lavage fluid, compared to those parameters in CMV and standard MAP-HFO.Conclusions: These findings suggest that only high MAP setting during HFO could contribute to decreased lung inflammation as well as improved oxygenation during the development of ALI.Keywords: lung protective ventilation, open lung ventilation, IL-8, neutrophil

  20. Leveling the field: The role of training, safety programs, and knowledge management systems in fostering inclusive field settings

    Science.gov (United States)

    Starkweather, S.; Crain, R.; Derry, K. R.

    2017-12-01

    Knowledge is empowering in all settings, but plays an elevated role in empowering under-represented groups in field research. Field research, particularly polar field research, has deep roots in masculinized and colonial traditions, which can lead to high barriers for women and minorities (e.g. Carey et al., 2016). While recruitment of underrepresented groups into polar field research has improved through the efforts of organizations like the Association of Polar Early Career Scientists (APECS), the experiences and successes of these participants is often contingent on the availability of specialized training opportunities or the quality of explicitly documented information about how to survive Arctic conditions or how to establish successful measurement protocols in harsh environments. In Arctic field research, knowledge is often not explicitly documented or conveyed, but learned through "experience" or informally through ad hoc advice. The advancement of field training programs and knowledge management systems suggest two means for unleashing more explicit forms of knowledge about field work. Examples will be presented along with a case for how they level the playing field and improve the experience of field work for all participants.

  1. Functional Testing and Characterisation of ISFETs on Wafer Level by Means of a Micro-droplet Cell

    Directory of Open Access Journals (Sweden)

    Michael J. Schöning

    2006-04-01

    Full Text Available A wafer-level functionality testing and characterisation system for ISFETs (ion-sensitive field-effect transistor is realised by means of integration of a specifically designedcapillary electrochemical micro-droplet cell into a commercial wafer prober-station. Thedeveloped system allows the identification and selection of “good” ISFETs at the earlieststage and to avoid expensive bonding, encapsulation and packaging processes for non-functioning ISFETs and thus, to decrease costs, which are wasted for bad dies. Thedeveloped system is also feasible for wafer-level characterisation of ISFETs in terms ofsensitivity, hysteresis and response time. Additionally, the system might be also utilised forwafer-level testing of further electrochemical sensors.

  2. Serum Copper Level Significantly Influences Platelet Count, Lymphocyte Count and Mean Cell Hemoglobin in Sickle Cell Anemia

    Directory of Open Access Journals (Sweden)

    Okocha Chide

    2015-12-01

    Full Text Available Background Changes in serum micro nutrients levels affect a number of critically important metabolic processes; these could potentially influence blood counts and ultimately disease presentation in patients with sickle cell anemia (SCA. Objectives To evaluate the influence of serum micro-nutrients levels; zinc, copper, selenium and magnesium on blood counts in steady state SCA patients. Methods A cross sectional study that involved 28 steady state adult SCA subjects. Seven milliliters (mls of blood was collected; 3 mls was for hemoglobin electrophoresis and full blood count determination while 4 mls was for measurement of serum micro nutrients levels, by the atomic absorption spectrophotometry. Correlation between serum micro-nutrient levels and blood counts was done by the Pearson’s linear regression. Ethical approval was obtained from the institutional review board and each participant gave informed consent. All data was analyzed by SPSS software version 20. Results There was a significant correlation between serum copper levels and mean cell hemoglobin (MCH, platelet and lymphocyte counts (r = 0.418; P = 0.02, r = -0.376; P = 0.04 and r = -0.383; P = 0.04, respectively. There were no significant correlations between serum levels of other micro nutrients (selenium, zinc and magnesium and blood counts. Conclusions Copper influences blood count in SCA patients probably by inducing red cell haemolysis, oxidant tissue damage and stimulating the immune system.

  3. A two-level strategy to realize life-cycle production optimization in an operational setting

    NARCIS (Netherlands)

    Essen, van G.M.; Hof, Van den P.M.J.; Jansen, J.D.

    2012-01-01

    We present a two-level strategy to improve robustness against uncertainty and model errors in life-cycle flooding optimization. At the upper level, a physics-based large-scale reservoir model is used to determine optimal life-cycle injection and production profiles. At the lower level these profiles

  4. A two-level strategy to realize life-cycle production optimization in an operational setting

    NARCIS (Netherlands)

    Essen, van G.M.; Hof, Van den P.M.J.; Jansen, J.D.

    2013-01-01

    We present a two-level strategy to improve robustness against uncertainty and model errors in life-cycle flooding optimization. At the upper level, a physics-based large-scale reservoir model is used to determine optimal life-cycle injection and production profiles. At the lower level these profiles

  5. SET overexpression in HEK293 cells regulates mitochondrial uncoupling proteins levels within a mitochondrial fission/reduced autophagic flux scenario

    Energy Technology Data Exchange (ETDEWEB)

    Almeida, Luciana O.; Goto, Renata N. [Department of Clinical Analyses, Toxicology and Food Sciences, School of Pharmaceutical Sciences of Ribeirão Preto, University of São Paulo, Ribeirão Preto, SP (Brazil); Neto, Marinaldo P.C. [Department of Physics and Chemistry, School of Pharmaceutical Sciences of Ribeirão Preto, University of São Paulo, Ribeirão Preto, SP (Brazil); Sousa, Lucas O. [Department of Clinical Analyses, Toxicology and Food Sciences, School of Pharmaceutical Sciences of Ribeirão Preto, University of São Paulo, Ribeirão Preto, SP (Brazil); Curti, Carlos [Department of Physics and Chemistry, School of Pharmaceutical Sciences of Ribeirão Preto, University of São Paulo, Ribeirão Preto, SP (Brazil); Leopoldino, Andréia M., E-mail: andreiaml@usp.br [Department of Clinical Analyses, Toxicology and Food Sciences, School of Pharmaceutical Sciences of Ribeirão Preto, University of São Paulo, Ribeirão Preto, SP (Brazil)

    2015-03-06

    We hypothesized that SET, a protein accumulated in some cancer types and Alzheimer disease, is involved in cell death through mitochondrial mechanisms. We addressed the mRNA and protein levels of the mitochondrial uncoupling proteins UCP1, UCP2 and UCP3 (S and L isoforms) by quantitative real-time PCR and immunofluorescence as well as other mitochondrial involvements, in HEK293 cells overexpressing the SET protein (HEK293/SET), either in the presence or absence of oxidative stress induced by the pro-oxidant t-butyl hydroperoxide (t-BHP). SET overexpression in HEK293 cells decreased UCP1 and increased UCP2 and UCP3 (S/L) mRNA and protein levels, whilst also preventing lipid peroxidation and decreasing the content of cellular ATP. SET overexpression also (i) decreased the area of mitochondria and increased the number of organelles and lysosomes, (ii) increased mitochondrial fission, as demonstrated by increased FIS1 mRNA and FIS-1 protein levels, an apparent accumulation of DRP-1 protein, and an increase in the VDAC protein level, and (iii) reduced autophagic flux, as demonstrated by a decrease in LC3B lipidation (LC3B-II) in the presence of chloroquine. Therefore, SET overexpression in HEK293 cells promotes mitochondrial fission and reduces autophagic flux in apparent association with up-regulation of UCP2 and UCP3; this implies a potential involvement in cellular processes that are deregulated such as in Alzheimer's disease and cancer. - Highlights: • SET, UCPs and autophagy prevention are correlated. • SET action has mitochondrial involvement. • UCP2/3 may reduce ROS and prevent autophagy. • SET protects cell from ROS via UCP2/3.

  6. Investigating the influence of anthropogenic forcing on observed mean and extreme sea level pressure trends over the Mediterranean Region.

    Science.gov (United States)

    Barkhordarian, Armineh

    2012-01-01

    We investigate whether the observed mean sea level pressure (SLP) trends over the Mediterranean region in the period from 1975 to 2004 are significantly consistent with what 17 models projected as response of SLP to anthropogenic forcing (greenhouse gases and sulphate aerosols, GS). Obtained results indicate that the observed trends in mean SLP cannot be explained by natural (internal) variability. Externally forced changes are detectable in all seasons, except spring. The large-scale component (spatial mean) of the GS signal is detectable in all the 17 models in winter and in 12 of the 17 models in summer. However, the small-scale component (spatial anomalies about the spatial mean) of GS signal is only detectable in winter within 11 of the 17 models. We also show that GS signal has a detectable influence on observed decreasing (increasing) tendency in the frequencies of extremely low (high) SLP days in winter and that these changes cannot be explained by internal climate variability. While the detection of GS forcing is robust in winter and summer, there are striking inconsistencies in autumn, where analysis points to the presence of an external forcing, which is not GS forcing.

  7. A variational approach to multi-phase motion of gas, liquid and solid based on the level set method

    Science.gov (United States)

    Yokoi, Kensuke

    2009-07-01

    We propose a simple and robust numerical algorithm to deal with multi-phase motion of gas, liquid and solid based on the level set method [S. Osher, J.A. Sethian, Front propagating with curvature-dependent speed: Algorithms based on Hamilton-Jacobi formulation, J. Comput. Phys. 79 (1988) 12; M. Sussman, P. Smereka, S. Osher, A level set approach for capturing solution to incompressible two-phase flow, J. Comput. Phys. 114 (1994) 146; J.A. Sethian, Level Set Methods and Fast Marching Methods, Cambridge University Press, 1999; S. Osher, R. Fedkiw, Level Set Methods and Dynamics Implicit Surface, Applied Mathematical Sciences, vol. 153, Springer, 2003]. In Eulerian framework, to simulate interaction between a moving solid object and an interfacial flow, we need to define at least two functions (level set functions) to distinguish three materials. In such simulations, in general two functions overlap and/or disagree due to numerical errors such as numerical diffusion. In this paper, we resolved the problem using the idea of the active contour model [M. Kass, A. Witkin, D. Terzopoulos, Snakes: active contour models, International Journal of Computer Vision 1 (1988) 321; V. Caselles, R. Kimmel, G. Sapiro, Geodesic active contours, International Journal of Computer Vision 22 (1997) 61; G. Sapiro, Geometric Partial Differential Equations and Image Analysis, Cambridge University Press, 2001; R. Kimmel, Numerical Geometry of Images: Theory, Algorithms, and Applications, Springer-Verlag, 2003] introduced in the field of image processing.

  8. Computerized detection of multiple sclerosis candidate regions based on a level set method using an artificial neural network

    International Nuclear Information System (INIS)

    Kuwazuru, Junpei; Magome, Taiki; Arimura, Hidetaka; Yamashita, Yasuo; Oki, Masafumi; Toyofuku, Fukai; Kakeda, Shingo; Yamamoto, Daisuke

    2010-01-01

    Yamamoto et al. developed the system for computer-aided detection of multiple sclerosis (MS) candidate regions. In a level set method in their proposed method, they employed the constant threshold value for the edge indicator function related to a speed function of the level set method. However, it would be appropriate to adjust the threshold value to each MS candidate region, because the edge magnitudes in MS candidates differ from each other. Our purpose of this study was to develop a computerized detection of MS candidate regions in MR images based on a level set method using an artificial neural network (ANN). To adjust the threshold value for the edge indicator function in the level set method to each true positive (TP) and false positive (FP) region, we constructed the ANN. The ANN could provide the suitable threshold value for each candidate region in the proposed level set method so that TP regions can be segmented and FP regions can be removed. Our proposed method detected MS regions at a sensitivity of 82.1% with 0.204 FPs per slice and similarity index of MS candidate regions was 0.717 on average. (author)

  9. Classification of upper limb disability levels of children with spastic unilateral cerebral palsy using K-means algorithm.

    Science.gov (United States)

    Raouafi, Sana; Achiche, Sofiane; Begon, Mickael; Sarcher, Aurélie; Raison, Maxime

    2018-01-01

    Treatment for cerebral palsy depends upon the severity of the child's condition and requires knowledge about upper limb disability. The aim of this study was to develop a systematic quantitative classification method of the upper limb disability levels for children with spastic unilateral cerebral palsy based on upper limb movements and muscle activation. Thirteen children with spastic unilateral cerebral palsy and six typically developing children participated in this study. Patients were matched on age and manual ability classification system levels I to III. Twenty-three kinematic and electromyographic variables were collected from two tasks. Discriminative analysis and K-means clustering algorithm were applied using 23 kinematic and EMG variables of each participant. Among the 23 kinematic and electromyographic variables, only two variables containing the most relevant information for the prediction of the four levels of severity of spastic unilateral cerebral palsy, which are fixed by manual ability classification system, were identified by discriminant analysis: (1) the Falconer index (CAI E ) which represents the ratio of biceps to triceps brachii activity during extension and (2) the maximal angle extension (θ Extension,max ). A good correlation (Kendall Rank correlation coefficient = -0.53, p = 0.01) was found between levels fixed by manual ability classification system and the obtained classes. These findings suggest that the cost and effort needed to assess and characterize the disability level of a child can be further reduced.

  10. Comparing Panelists' Understanding of Standard Setting across Multiple Levels of an Alternate Science Assessment

    Science.gov (United States)

    Hansen, Mary A.; Lyon, Steven R.; Heh, Peter; Zigmond, Naomi

    2013-01-01

    Large-scale assessment programs, including alternate assessments based on alternate achievement standards (AA-AAS), must provide evidence of technical quality and validity. This study provides information about the technical quality of one AA-AAS by evaluating the standard setting for the science component. The assessment was designed to have…

  11. Evaluation of the relationship between serum apelin levels and vitamin D and mean platelet volume in diabetic patients.

    Science.gov (United States)

    Kiskac, Muharrem; Zorlu, Mehmet; Cakirca, Mustafa; Karatoprak, Cumali; Kesgin, Sıdıka; Büyükaydın, Banu; Yavuz, Erdinc; Ardic, Cuneyt; Camli, Ahmet Adil; Cikrikcioglu, Mehmet Ali

    2014-09-01

    It was reported that Vitamin D deficiency was associated with a greater risk of cardiometabolic diseases, obesity, impaired glucose tolerance and diabetes mellitus type 2, arterial hypertension, and dyslipidemia. Apelin is an adipocytokine suspected to have a role in skeletal muscle glucose utilization and glycemic regulation which may be a promising treatment modality for diabetes. It was recently reported that increased mean platelet volume (MPV) was emerging as an independent risk factor for thromboembolism, stroke, and myocardial infarction. In patients with diabetes, MPV was higher compared with the normal glycemic controls; in addition, it has been proposed that an increase in MPV may play a role in the micro- and macro-vascular complications related to diabetes. We postulated that deficiency in Vitamin D levels might be associated with higher MPV and lower serum apelin levels leading a further increase in insulin resistance in diabetic patients. So, we aimed to investigate Vitamin D levels, MPV and serum apelin levels in diabetic patients and their correlations between each other. This is a cross-sectional study design. Seventy-eight patients with Diabetes Mellitus type 2, admitted to our outpatient clinic of internal medicine department at Bezmialem Vakif University, were included in our study. Forty-one patients were female; 37 patients were male. Serum apelin levels, fasting glucose levels, urea, creatinine, triglycerides, total cholesterol, low-density lipoprotein cholesterol (LDL-C), high-density lipoprotein cholesterol (HDL-C), fasting serum insulin level, HbA1c, free T3, free T4, TSH, vitamin D (25-OH Vitamin D) and complete blood counts were analyzed in all subjects. Each sex was analyzed separately. We found that a positive correlation existed between serum apelin levels and BMI in female patients. (r: 0.380, P: 0.014) There was also a significant positive correlation between MPV and HbA1c and fasting glucose levels and a negative correlation

  12. Organizational factors related to low levels of sickness absence in a representative set of Swedish companies.

    Science.gov (United States)

    Stoetzer, Ulrich; Bergman, Peter; Aborg, Carl; Johansson, Gun; Ahlberg, Gunnel; Parmsund, Marianne; Svartengren, Magnus

    2014-01-01

    The aim of this qualitative study was to identify manageable organizational factors that could explain why some companies have low levels of sickness absence. There may be factors at company level that can be managed to influence levels of sickness absence, and promote health and a prosperous organization. 38 representative Swedish companies. The study included a total of 204 semi-structured interviews at 38 representative Swedish companies. Qualitative thematic analysis was applied to the interviews, primarily with managers, to indicate the organizational factors that characterize companies with low levels of sickness absence. The factors that were found to characterize companies with low levels of sickness absence concerned strategies and procedures for managing leadership, employee development, communication, employee participation and involvement, corporate values and visions, and employee health. The results may be useful in finding strategies and procedures to reduce levels of sickness absence and promote health. There is research at individual level on the reasons for sickness absence. This study tries to elevate the issue to an organizational level. The findings suggest that explicit strategies for managing certain organizational factors can reduce sickness absence and help companies to develop more health-promoting strategies.

  13. Level set method for computational multi-fluid dynamics: A review on ...

    Indian Academy of Sciences (India)

    to multi fluid/phase as well as to various types of two-phase flow. In the second ...... simulated bubble generation in a quiescent and co-flowing fluid, for various liquid-to-gas mean injection velocity at ... in modelling of droplet impact behaviour.

  14. Dynamic-thresholding level set: a novel computer-aided volumetry method for liver tumors in hepatic CT images

    Science.gov (United States)

    Cai, Wenli; Yoshida, Hiroyuki; Harris, Gordon J.

    2007-03-01

    Measurement of the volume of focal liver tumors, called liver tumor volumetry, is indispensable for assessing the growth of tumors and for monitoring the response of tumors to oncology treatments. Traditional edge models, such as the maximum gradient and zero-crossing methods, often fail to detect the accurate boundary of a fuzzy object such as a liver tumor. As a result, the computerized volumetry based on these edge models tends to differ from manual segmentation results performed by physicians. In this study, we developed a novel computerized volumetry method for fuzzy objects, called dynamic-thresholding level set (DT level set). An optimal threshold value computed from a histogram tends to shift, relative to the theoretical threshold value obtained from a normal distribution model, toward a smaller region in the histogram. We thus designed a mobile shell structure, called a propagating shell, which is a thick region encompassing the level set front. The optimal threshold calculated from the histogram of the shell drives the level set front toward the boundary of a liver tumor. When the volume ratio between the object and the background in the shell approaches one, the optimal threshold value best fits the theoretical threshold value and the shell stops propagating. Application of the DT level set to 26 hepatic CT cases with 63 biopsy-confirmed hepatocellular carcinomas (HCCs) and metastases showed that the computer measured volumes were highly correlated with those of tumors measured manually by physicians. Our preliminary results showed that DT level set was effective and accurate in estimating the volumes of liver tumors detected in hepatic CT images.

  15. An Accurate Fire-Spread Algorithm in the Weather Research and Forecasting Model Using the Level-Set Method

    Science.gov (United States)

    Muñoz-Esparza, Domingo; Kosović, Branko; Jiménez, Pedro A.; Coen, Janice L.

    2018-04-01

    The level-set method is typically used to track and propagate the fire perimeter in wildland fire models. Herein, a high-order level-set method using fifth-order WENO scheme for the discretization of spatial derivatives and third-order explicit Runge-Kutta temporal integration is implemented within the Weather Research and Forecasting model wildland fire physics package, WRF-Fire. The algorithm includes solution of an additional partial differential equation for level-set reinitialization. The accuracy of the fire-front shape and rate of spread in uncoupled simulations is systematically analyzed. It is demonstrated that the common implementation used by level-set-based wildfire models yields to rate-of-spread errors in the range 10-35% for typical grid sizes (Δ = 12.5-100 m) and considerably underestimates fire area. Moreover, the amplitude of fire-front gradients in the presence of explicitly resolved turbulence features is systematically underestimated. In contrast, the new WRF-Fire algorithm results in rate-of-spread errors that are lower than 1% and that become nearly grid independent. Also, the underestimation of fire area at the sharp transition between the fire front and the lateral flanks is found to be reduced by a factor of ≈7. A hybrid-order level-set method with locally reduced artificial viscosity is proposed, which substantially alleviates the computational cost associated with high-order discretizations while preserving accuracy. Simulations of the Last Chance wildfire demonstrate additional benefits of high-order accurate level-set algorithms when dealing with complex fuel heterogeneities, enabling propagation across narrow fuel gaps and more accurate fire backing over the lee side of no fuel clusters.

  16. Validation of a non-uniform meshing algorithm for the 3D-FDTD method by means of a two-wire crosstalk experimental set-up

    Directory of Open Access Journals (Sweden)

    Raúl Esteban Jiménez-Mejía

    2015-06-01

    Full Text Available This paper presents an algorithm used to automatically mesh a 3D computational domain in order to solve electromagnetic interaction scenarios by means of the Finite-Difference Time-Domain -FDTD-  Method. The proposed algorithm has been formulated in a general mathematical form, where convenient spacing functions can be defined for the problem space discretization, allowing the inclusion of small sized objects in the FDTD method and the calculation of detailed variations of the electromagnetic field at specified regions of the computation domain. The results obtained by using the FDTD method with the proposed algorithm have been contrasted not only with a typical uniform mesh algorithm, but also with experimental measurements for a two-wire crosstalk set-up, leading to excellent agreement between theoretical and experimental waveforms. A discussion about the advantages of the non-uniform mesh over the uniform one is also presented.

  17. THE PROBLEM OF USING GADGETS AS A MEANS OF FALSIFICATION OF RESULTS CHECK LEVEL OF STUDENTS KNOWLEDGE

    Directory of Open Access Journals (Sweden)

    Vyacheslav A. Lipatov

    2016-01-01

    Full Text Available Abstract. The aim of the present research is studying of the range, technical characteristics, and also price categories of micro earphones, the devices intended for simplification by the pupil of examination and distorting the level of knowledge on control activities.Methods. The formalized interview is used as the main method of the research, i.e. a conversation on detailed developed program including a consistent design of seventeen closed and open questions, and also versions of possible answers.Results. The suppliers and sellers of micro earphones were interviewed on the Internet by mobile communication. Besides, the analysis of the relevant information posted at discussion boards, social networks, etc. is carried out. Statistical material is processed, tabulated and visually demonstrated in charts. The obtained data allow us to estimate geography, specification of types, a technical and price variety of the technical means which are used by students to falsification of results of their education. The conclusion is drawn that this type of devices in the Russian market promptly extends and is in huge demand both with students and school pupils.Scientific novelty. The opinions of suppliers and sellers regarding technical characteristics, harm to health and availability of micro earphones to pupils are studied for the first time. The range of offers and price range of these gadgets are analysed.Practical significance. The present investigation can serve as informative basis while developing the recommendations and methods of fight against application of technical means for cheating using electronic technical means at various stages of control of knowledge. These measures are necessary for identification of actual, but not fictitious level of knowledge of pupils, and improvement of quality of education in higher education institutions and schools. 

  18. On piecewise constant level-set (PCLS) methods for the identification of discontinuous parameters in ill-posed problems

    International Nuclear Information System (INIS)

    De Cezaro, A; Leitão, A; Tai, X-C

    2013-01-01

    We investigate level-set-type methods for solving ill-posed problems with discontinuous (piecewise constant) coefficients. The goal is to identify the level sets as well as the level values of an unknown parameter function on a model described by a nonlinear ill-posed operator equation. The PCLS approach is used here to parametrize the solution of a given operator equation in terms of a L 2 level-set function, i.e. the level-set function itself is assumed to be a piecewise constant function. Two distinct methods are proposed for computing stable solutions of the resulting ill-posed problem: the first is based on Tikhonov regularization, while the second is based on the augmented Lagrangian approach with total variation penalization. Classical regularization results (Engl H W et al 1996 Mathematics and its Applications (Dordrecht: Kluwer)) are derived for the Tikhonov method. On the other hand, for the augmented Lagrangian method, we succeed in proving the existence of (generalized) Lagrangian multipliers in the sense of (Rockafellar R T and Wets R J-B 1998 Grundlehren der Mathematischen Wissenschaften (Berlin: Springer)). Numerical experiments are performed for a 2D inverse potential problem (Hettlich F and Rundell W 1996 Inverse Problems 12 251–66), demonstrating the capabilities of both methods for solving this ill-posed problem in a stable way (complicated inclusions are recovered without any a priori geometrical information on the unknown parameter). (paper)

  19. Area-level risk factors for adverse birth outcomes: trends in urban and rural settings

    OpenAIRE

    Kent, Shia T; McClure, Leslie A; Zaitchik, Ben F; Gohlke, Julia M

    2013-01-01

    Background Significant and persistent racial and income disparities in birth outcomes exist in the US. The analyses in this manuscript examine whether adverse birth outcome time trends and associations between area-level variables and adverse birth outcomes differ by urban?rural status. Methods Alabama births records were merged with ZIP code-level census measures of race, poverty, and rurality. B-splines were used to determine long-term preterm birth (PTB) and low birth weight (LBW) trends b...

  20. Representing the Fuzzy improved risk graph for determination of optimized safety integrity level in industrial setting

    Directory of Open Access Journals (Sweden)

    Z. Qorbali

    2013-12-01

    .Conclusion: as a result of establishing the presented method, identical levels in conventional risk graph table are replaced with different sublevels that not only increases the accuracy in determining the SIL, but also elucidates the effective factor in improving the safety level and consequently saves time and cost significantly. The proposed technique has been employed to develop the SIL of Tehran Refinery ISOMAX Center. IRG and FIRG results have been compared to clarify the efficacy and importance of the proposed method

  1. Experiences and shared meaning of teamwork and interprofessional collaboration among health care professionals in primary health care settings: a systematic review.

    Science.gov (United States)

    Sangaleti, Carine; Schveitzer, Mariana Cabral; Peduzzi, Marina; Zoboli, Elma Lourdes Campos Pavone; Soares, Cassia Baldini

    2017-11-01

    During the last decade, teamwork has been addressed under the rationale of interprofessional practice or collaboration, highlighted by the attributes of this practice such as: interdependence of professional actions, focus on user needs, negotiation between professionals, shared decision making, mutual respect and trust among professionals, and acknowledgment of the role and work of the different professional groups. Teamwork and interprofessional collaboration have been pointed out as astrategy for effective organization of health care services as the complexity of healthcare requires integration of knowledge and practices from differente professional groups. This integration has a qualitative dimension that can be identified through the experiences of health professionals and to the meaning they give to teamwork. The objective of this systematic review was to synthesize the best available evidence on the experiences of health professionals regarding teamwork and interprofessional collaboration in primary health care settings. The populations included were all officially regulated health professionals that work in primary health settings: dentistry, medicine, midwifery, nursing, nutrition, occupational therapy, pharmacy, physical education, physiotherapy, psychology, social work and speech therapy. In addition to these professionals, community health workers, nursing assistants, licensed practical nurses and other allied health workers were also included. The phenomena of interest were experiences of health professionals regarding teamwork and interprofessional collaboration in primary health care settings. The context was primary health care settings that included health care centers, health maintenance organizations, integrative medicine practices, integrative health care, family practices, primary care organizations and family medical clinics. National health surgery as a setting was excluded. The qualitative component of the review considered studies that

  2. On the Level Set of a Function with Degenerate Minimum Point

    Directory of Open Access Journals (Sweden)

    Yasuhiko Kamiyama

    2015-01-01

    Full Text Available For n≥2, let M be an n-dimensional smooth closed manifold and f:M→R a smooth function. We set minf(M=m and assume that m is attained by unique point p∈M such that p is a nondegenerate critical point. Then the Morse lemma tells us that if a is slightly bigger than m, f-1(a is diffeomorphic to Sn-1. In this paper, we relax the condition on p from being nondegenerate to being an isolated critical point and obtain the same consequence. Some application to the topology of polygon spaces is also included.

  3. CUDA based Level Set Method for 3D Reconstruction of Fishes from Large Acoustic Data

    DEFF Research Database (Denmark)

    Sharma, Ojaswa; Anton, François

    2009-01-01

    Acoustic images present views of underwater dynamics, even in high depths. With multi-beam echo sounders (SONARs), it is possible to capture series of 2D high resolution acoustic images. 3D reconstruction of the water column and subsequent estimation of fish abundance and fish species identificat...... of suppressing threshold and show its convergence as the evolution proceeds. We also present a GPU based streaming computation of the method using NVIDIA's CUDA framework to handle large volume data-sets. Our implementation is optimised for memory usage to handle large volumes....

  4. Area-level risk factors for adverse birth outcomes: trends in urban and rural settings.

    Science.gov (United States)

    Kent, Shia T; McClure, Leslie A; Zaitchik, Ben F; Gohlke, Julia M

    2013-06-10

    Significant and persistent racial and income disparities in birth outcomes exist in the US. The analyses in this manuscript examine whether adverse birth outcome time trends and associations between area-level variables and adverse birth outcomes differ by urban-rural status. Alabama births records were merged with ZIP code-level census measures of race, poverty, and rurality. B-splines were used to determine long-term preterm birth (PTB) and low birth weight (LBW) trends by rurality. Logistic regression models were used to examine differences in the relationships between ZIP code-level percent poverty or percent African-American with either PTB or LBW. Interactions with rurality were examined. Population dense areas had higher adverse birth outcome rates compared to other regions. For LBW, the disparity between population dense and other regions increased during the 1991-2005 time period, and the magnitude of the disparity was maintained through 2010. Overall PTB and LBW rates have decreased since 2006, except within isolated rural regions. The addition of individual-level socioeconomic or race risk factors greatly attenuated these geographical disparities, but isolated rural regions maintained increased odds of adverse birth outcomes. ZIP code-level percent poverty and percent African American both had significant relationships with adverse birth outcomes. Poverty associations remained significant in the most population-dense regions when models were adjusted for individual-level risk factors. Population dense urban areas have heightened rates of adverse birth outcomes. High-poverty African American areas have higher odds of adverse birth outcomes in urban versus rural regions. These results suggest there are urban-specific social or environmental factors increasing risk for adverse birth outcomes in underserved communities. On the other hand, trends in PTBs and LBWs suggest interventions that have decreased adverse birth outcomes elsewhere may not be reaching

  5. Mean hemoglobin levels in venous blood samples and prevalence of anemia in Japanese elementary and junior high school students.

    Science.gov (United States)

    Igarashi, Toru; Itoh, Yasuhiko; Maeda, Miho; Igarashi, Tsutomu; Fukunaga, Yoshitaka

    2012-01-01

    Screening for anemia has been performed in schools in Japan for over 30 years. The long-term effect of the nuclear power plant disaster on the prevalence of anemia in school age children is unknown. This research was performed to evaluate the prevalence of anemia in school age children and to determine grade-level and gender-related reference hemoglobin (Hb) levels prior to the nuclear disaster. Data for this research were obtained from results of screening for anemia obtained by venous blood sampling in schools in 2002. Mean Hb levels were calculated for each grade level (elementary school grades 1-6 and junior high school years 1-3) and according to gender, and the prevalence of anemia was determined. In our research, Tokyo Health Service Association guidelines were used to determine reference Hb levels for anemia. We demonstrated that Hb levels in boys increased with age during childhood and adolescence (from 13.1 ± 0.7 g/dL in 7 year olds to 14.9 ± 1.1 g/dL in 15 year olds); in girls, Hb levels peaked at menarche (13.7 ± 0.8 g/dL in 12 year olds), decreasing slightly thereafter (13.4 ± 1.1 g/dL in 15 year olds). The prevalence of anemia was 0.26% in elementary school boys, 0.27% in elementary school girls, and 1.21% in junior high school boys. The prevalence of anemia in second- and third-year junior high school girls was lower than that in first-year junior high school girls. Among all junior high school girls, 5.73% had mild anemia. Iron-deficiency anemia is the commonest type of anemia in high school girls, secondary to the relative lack of iron due to menstruation, the growth spurt and exercise. Appropriate dietary therapy and treatment of anemia, together with education about the dietary prevention of anemia, are important to reduce the prevalence of anemia in high school students. When complete blood counts are performed in regions thought to be affected by the Fukushima nuclear power plant disaster, our report can serve as a reference during

  6. Mean hemoglobin levels in venous blood samples and prevalence of anemia in Japanese elementary and junior high school students

    International Nuclear Information System (INIS)

    Igarashi, Toru; Itoh, Yasuhiko; Maeda, Miho; Igarashi, Tsutomu; Fukunaga, Yoshitaka

    2012-01-01

    Screening for anemia has been performed in schools in Japan for over 30 years. The long-term effect of the nuclear power plant disaster on the prevalence of anemia in school age children is unknown. This research was performed to evaluate the prevalence of anemia in school age children and to determine grade-level and gender-related reference hemoglobin (Hb) levels prior to the nuclear disaster. Data for this research were obtained from results of screening for anemia obtained by venous blood sampling in schools in 2002. Mean Hb levels were calculated for each grade level (elementary school grades 1-6 and junior high school years 1-3) and according to gender, and the prevalence of anemia was determined. In our research, Tokyo Health Service Association guidelines were used to determine reference Hb levels for anemia. We demonstrated that Hb levels in boys increased with age during childhood and adolescence (from 13.1±0.7 g/dL in 7 year olds to 14.9±1.1 g/dL in 15 year olds); in girls, Hb levels peaked at menarche (13.7±0.8 g/dL in 12 year olds), decreasing slightly thereafter (13.4±1.1 g/dL in 15 year olds). The prevalence of anemia was 0.26% in elementary school boys, 0.27% in elementary school girls, and 1.21% in junior high school boys. The prevalence of anemia in second- and third-year junior high school girls was lower than that in first-year junior high school girls. Among all junior high school girls, 5.73% had mild anemia. Iron-deficiency anemia is the commonest type of anemia in high school girls, secondary to the relative lack of iron due to menstruation, the growth spurt and exercise. Appropriate dietary therapy and treatment of anemia, together with education about the dietary prevention of anemia, are important to reduce the prevalence of anemia in high school students. When complete blood counts are performed in regions thought to be affected by the Fukushima nuclear power plant disaster, our report can serve as a reference during evaluation of Hb

  7. Change in Vitamin D Levels Occurs Early after Antiretroviral Therapy Initiation and Depends on Treatment Regimen in Resource-Limited Settings

    Science.gov (United States)

    Havers, Fiona P.; Detrick, Barbara; Cardoso, Sandra W.; Berendes, Sima; Lama, Javier R.; Sugandhavesa, Patcharaphan; Mwelase, Noluthando H.; Campbell, Thomas B.; Gupta, Amita

    2014-01-01

    Study Background Vitamin D has wide-ranging effects on the immune system, and studies suggest that low serum vitamin D levels are associated with worse clinical outcomes in HIV. Recent studies have identified an interaction between antiretrovirals used to treat HIV and reduced serum vitamin D levels, but these studies have been done in North American and European populations. Methods Using a prospective cohort study design nested in a multinational clinical trial, we examined the effect of three combination antiretroviral (cART) regimens on serum vitamin D levels in 270 cART-naïve, HIV-infected adults in nine diverse countries, (Brazil, Haiti, Peru, Thailand, India, Malawi, South Africa, Zimbabwe and the United States). We evaluated the change between baseline serum vitamin D levels and vitamin D levels 24 and 48 weeks after cART initiation. Results Serum vitamin D levels decreased significantly from baseline to 24 weeks among those randomized to efavirenz/lamivudine/zidovudine (mean change: −7.94 [95% Confidence Interval (CI) −10.42, −5.54] ng/ml) and efavirenz/emtricitabine/tenofovir-DF (mean change: −6.66 [95% CI −9.40, −3.92] ng/ml) when compared to those randomized to atazanavir/emtricitabine/didanosine-EC (mean change: −2.29 [95% CI –4.83, 0.25] ng/ml). Vitamin D levels did not change significantly between week 24 and 48. Other factors that significantly affected serum vitamin D change included country (p<0.001), season (p<0.001) and baseline vitamin D level (p<0.001). Conclusion Efavirenz-containing cART regimens adversely affected vitamin D levels in patients from economically, geographically and racially diverse resource-limited settings. This effect was most pronounced early after cART initiation. Research is needed to define the role of Vitamin D supplementation in HIV care. PMID:24752177

  8. County-Level Poverty Is Equally Associated with Unmet Health Care Needs in Rural and Urban Settings

    Science.gov (United States)

    Peterson, Lars E.; Litaker, David G.

    2010-01-01

    Context: Regional poverty is associated with reduced access to health care. Whether this relationship is equally strong in both rural and urban settings or is affected by the contextual and individual-level characteristics that distinguish these areas, is unclear. Purpose: Compare the association between regional poverty with self-reported unmet…

  9. The Daily Events and Emotions of Master's-Level Family Therapy Trainees in Off-Campus Practicum Settings

    Science.gov (United States)

    Edwards, Todd M.; Patterson, Jo Ellen

    2012-01-01

    The Day Reconstruction Method (DRM) was used to assess the daily events and emotions of one program's master's-level family therapy trainees in off-campus practicum settings. This study examines the DRM reports of 35 family therapy trainees in the second year of their master's program in marriage and family therapy. Four themes emerged from the…

  10. Activity Sets in Multi-Organizational Ecologies : A Project-Level Perspective on Sustainable Energy Innovations

    NARCIS (Netherlands)

    Gerrit Willem Ziggers; Kristina Manser; Bas Hillebrand; Paul Driessen; Josée Bloemer

    2014-01-01

    Complex innovations involve multi-organizational ecologies consisting of a myriad of different actors. This study investigates how innovation activities can be interpreted in the context of multi-organizational ecologies. Taking a project-level perspective, this study proposes a typology of four

  11. Supporting Diverse Young Adolescents: Cooperative Grouping in Inclusive Middle-Level Settings

    Science.gov (United States)

    Miller, Nicole C.; McKissick, Bethany R.; Ivy, Jessica T.; Moser, Kelly

    2017-01-01

    The middle level classroom presents unique challenges to educators who strive to provide opportunities that acknowledge learner diversity in terms of social, cognitive, physical, and emotional development. This is confounded even further within inclusive middle-school classrooms where the responsibility to differentiate instruction is even more…

  12. Application de X-FEM et des level-sets à l'homogénéisation de matériaux aléatoires caractérisés par imagerie numérique

    OpenAIRE

    Ionescu , Irina; Moës , Nicolas; Cartraud , Patrice; Béringhier , Marianne

    2007-01-01

    International audience; The advances of material characterization by means of imaging techniques require powerful computational methods for numerical analyses. This paper focuses on the advantages of coupling the X-FEM and level sets to solve microstructures with complex geometry. The level set information is obtained from a digital image and then used within a X-FEM computation, where the mesh does not need to conform to the material interface. An example of homogeniza-tion is presented.; La...

  13. Effect of Average Annual Mean Serum Ferritin Levels on QTc Interval and QTc Dispersion in Beta-Thalassemia Major

    Directory of Open Access Journals (Sweden)

    Yazdan Ghandi

    2017-08-01

    Full Text Available Background There is evidence indicating impaired cardiomyocytic contractility, delayed electrical conduction and increased electrophysiological heterogeneities due to iron toxicity in beta-thalassemia major patients. In the present study, we compared the electrocardiographic and echocardiographic features of beta-thalassemia major patients with a healthy control group. Materials and Methods The average annual serum ferritin levels of fifty beta-thalassemia major patients were assessed. For each patient, corrected QT (QTc intervals and QTc dispersions (QTcd were calculated and V1S and V5R were measured. All subjects underwent two-dimensional M-mode echocardiography and Doppler study and were compared with 50 healthy subjects as a control group. Results QTc interval and dispersion were significantly higher in beta-thalassemia major patients (P= 0.001. The mean V5R (20.04 ± 4.34 vs. 17.14 ± 2.55 mm and V1S (10.24 ± 2.62 vs. 7.83 ± 0.38 mm showed considerably higher mean values in patients in comparison with control group.Peak mitral inflow velocity at early diastole and early to late ratio in the case- group was markedly higher(P

  14. Flipping for success: evaluating the effectiveness of a novel teaching approach in a graduate level setting

    OpenAIRE

    Moraros, John; Islam, Adiba; Yu, Stan; Banow, Ryan; Schindelka, Barbara

    2015-01-01

    Background Flipped Classroom is a model that?s quickly gaining recognition as a novel teaching approach among health science curricula. The purpose of this study was four-fold and aimed to compare Flipped Classroom effectiveness ratings with: 1) student socio-demographic characteristics, 2) student final grades, 3) student overall course satisfaction, and 4) course pre-Flipped Classroom effectiveness ratings. Methods The participants in the study consisted of 67 Masters-level graduate student...

  15. A highly efficient 3D level-set grain growth algorithm tailored for ccNUMA architecture

    Science.gov (United States)

    Mießen, C.; Velinov, N.; Gottstein, G.; Barrales-Mora, L. A.

    2017-12-01

    A highly efficient simulation model for 2D and 3D grain growth was developed based on the level-set method. The model introduces modern computational concepts to achieve excellent performance on parallel computer architectures. Strong scalability was measured on cache-coherent non-uniform memory access (ccNUMA) architectures. To achieve this, the proposed approach considers the application of local level-set functions at the grain level. Ideal and non-ideal grain growth was simulated in 3D with the objective to study the evolution of statistical representative volume elements in polycrystals. In addition, microstructure evolution in an anisotropic magnetic material affected by an external magnetic field was simulated.

  16. Implementing and measuring the level of laboratory service integration in a program setting in Nigeria.

    Directory of Open Access Journals (Sweden)

    Henry Mbah

    Full Text Available The surge of donor funds to fight HIV&AIDS epidemic inadvertently resulted in the setup of laboratories as parallel structures to rapidly respond to the identified need. However these parallel structures are a threat to the existing fragile laboratory systems. Laboratory service integration is critical to remedy this situation. This paper describes an approach to quantitatively measure and track integration of HIV-related laboratory services into the mainstream laboratory services and highlight some key intervention steps taken, to enhance service integration.A quantitative before-and-after study conducted in 122 Family Health International (FHI360 supported health facilities across Nigeria. A minimum service package was identified including management structure; trainings; equipment utilization and maintenance; information, commodity and quality management for laboratory integration. A check list was used to assess facilities at baseline and 3 months follow-up. Level of integration was assessed on an ordinal scale (0 = no integration, 1 = partial integration, 2 = full integration for each service package. A composite score grading expressed as a percentage of total obtainable score of 14 was defined and used to classify facilities (≤ 80% FULL, 25% to 79% PARTIAL and <25% NO integration. Weaknesses were noted and addressed.We analyzed 9 (7.4% primary, 104 (85.2% secondary and 9 (7.4% tertiary level facilities. There were statistically significant differences in integration levels between baseline and 3 months follow-up period (p<0.01. Baseline median total integration score was 4 (IQR 3 to 5 compared to 7 (IQR 4 to 9 at 3 months follow-up (p = 0.000. Partial and fully integrated laboratory systems were 64 (52.5% and 0 (0.0% at baseline, compared to 100 (82.0% and 3 (2.4% respectively at 3 months follow-up (p = 0.000.This project showcases our novel approach to measure the status of each laboratory on the integration continuum.

  17. County-level poverty is equally associated with unmet health care needs in rural and urban settings.

    Science.gov (United States)

    Peterson, Lars E; Litaker, David G

    2010-01-01

    Regional poverty is associated with reduced access to health care. Whether this relationship is equally strong in both rural and urban settings or is affected by the contextual and individual-level characteristics that distinguish these areas, is unclear. Compare the association between regional poverty with self-reported unmet need, a marker of health care access, by rural/urban setting. Multilevel, cross-sectional analysis of a state-representative sample of 39,953 adults stratified by rural/urban status, linked at the county level to data describing contextual characteristics. Weighted random intercept models examined the independent association of regional poverty with unmet needs, controlling for a range of contextual and individual-level characteristics. The unadjusted association between regional poverty levels and unmet needs was similar in both rural (OR = 1.06 [95% CI, 1.04-1.08]) and urban (OR = 1.03 [1.02-1.05]) settings. Adjusting for other contextual characteristics increased the size of the association in both rural (OR = 1.11 [1.04-1.19]) and urban (OR = 1.11 [1.05-1.18]) settings. Further adjustment for individual characteristics had little additional effect in rural (OR = 1.10 [1.00-1.20]) or urban (OR = 1.11 [1.01-1.22]) settings. To better meet the health care needs of all Americans, health care systems in areas with high regional poverty should acknowledge the relationship between poverty and unmet health care needs. Investments, or other interventions, that reduce regional poverty may be useful strategies for improving health through better access to health care. © 2010 National Rural Health Association.

  18. Comparing of goal setting strategy with group education method to increase physical activity level: A randomized trial.

    Science.gov (United States)

    Jiryaee, Nasrin; Siadat, Zahra Dana; Zamani, Ahmadreza; Taleban, Roya

    2015-10-01

    Designing an intervention to increase physical activity is important to be based on the health care settings resources and be acceptable by the subject group. This study was designed to assess and compare the effect of the goal setting strategy with a group education method on increasing the physical activity of mothers of children aged 1 to 5. Mothers who had at least one child of 1-5 years were randomized into two groups. The effect of 1) goal-setting strategy and 2) group education method on increasing physical activity was assessed and compared 1 month and 3 months after the intervention. Also, the weight, height, body mass index (BMI), waist and hip circumference, and well-being were compared between the two groups before and after the intervention. Physical activity level increased significantly after the intervention in the goal-setting group and it was significantly different between the two groups after intervention (P goal-setting group after the intervention. In the group education method, only the well-being score improved significantly (P goal-setting strategy to boost physical activity, improving the state of well-being and decreasing BMI, waist, and hip circumference.

  19. Comparing of goal setting strategy with group education method to increase physical activity level: A randomized trial

    Directory of Open Access Journals (Sweden)

    Nasrin Jiryaee

    2015-01-01

    Full Text Available Background: Designing an intervention to increase physical activity is important to be based on the health care settings resources and be acceptable by the subject group. This study was designed to assess and compare the effect of the goal setting strategy with a group education method on increasing the physical activity of mothers of children aged 1 to 5. Materials and Methods: Mothers who had at least one child of 1-5 years were randomized into two groups. The effect of 1 goal-setting strategy and 2 group education method on increasing physical activity was assessed and compared 1 month and 3 months after the intervention. Also, the weight, height, body mass index (BMI, waist and hip circumference, and well-being were compared between the two groups before and after the intervention. Results: Physical activity level increased significantly after the intervention in the goal-setting group and it was significantly different between the two groups after intervention (P < 0.05. BMI, waist circumference, hip circumference, and well-being score were significantly different in the goal-setting group after the intervention. In the group education method, only the well-being score improved significantly (P < 0.05. Conclusion: Our study presented the effects of using the goal-setting strategy to boost physical activity, improving the state of well-being and decreasing BMI, waist, and hip circumference.

  20. A possible methodological approach to setting up control level of radiation factors

    International Nuclear Information System (INIS)

    Devyatajkin, E.V.; Abramov, Yu.V.

    1986-01-01

    The mathematical formalization of the concept of control levels (CL) which enables one to obtain CL numerical values of controllable parameters required for rapid control purposes is described. The initial data for the assessment of environmental radioactivity are the controllable parameter values that is practical characteristic of controllable radiation factor showing technically measurable or calculation value. The controllable parameters can be divided into two classes depending on the degree of radiation effect on a man: possessing additivity properties (dosimetric class) and non-possessing (radiation class, which comprises the results of control of medium alteration dynamics, equipment operation safety, completeness of protection measures performance). The CL calculation formulas with account for requirements of radiation safety standards (RSS-76) are presented

  1. The Little Six Personality Dimensions From Early Childhood to Early Adulthood: Mean-Level Age and Gender Differences in Parents' Reports.

    Science.gov (United States)

    Soto, Christopher J

    2016-08-01

    The present research pursues three major goals. First, we develop scales to measure the Little Six youth personality dimensions: Extraversion, Agreeableness, Conscientiousness, Neuroticism, Openness to Experience, and Activity. Second, we examine mean-level age and gender differences in the Little Six from early childhood into early adulthood. Third, we examine the development of more specific nuance traits. We analyze parent reports, made using the common-language California Child Q-Set (CCQ), for a cross-sectional sample of 16,000 target children ranging from 3 to 20 years old. We construct CCQ-Little Six scales that reliably measure each Little Six dimension. Using these scales, we find (a) curvilinear, U-shaped age trends for Agreeableness, Conscientiousness, and Openness, with declines followed by subsequent inclines; (b) monotonic, negative age trends for Extraversion and Activity; (c) higher levels of Conscientiousness and Agreeableness among girls than boys, as well as higher levels of Activity among boys than girls; and (d) gender-specific age trends for Neuroticism, with girls scoring higher than boys by mid-adolescence. Finally, we find that several nuance traits show distinctive developmental trends that differ from their superordinate Little Six dimension. These results highlight childhood and adolescence as key periods of personality development. © 2015 Wiley Periodicals, Inc.

  2. Setting up experimental incineration system for low-level radioactive samples and combustion experiments

    International Nuclear Information System (INIS)

    Yumoto, Yasuhiro; Hanafusa, Tadashi; Nagamatsu, Tomohiro; Okada, Shigeru

    1997-01-01

    An incineration system was constructed which were composed of a combustion furnace (AP-150R), a cyclone dust collector, radioisotope trapping and measurement apparatus and a radioisotope storage room built in the first basement of the Radioisotope Center. Low level radioactive samples (LLRS) used for the combustion experiment were composed of combustible material or semi-combustible material containing 500 kBq of 99m TcO 4 or 23.25 kBq of 131 INa. The distribution of radioisotopes both in the inside and outside of combustion furnace were estimated. We measured radioactivity of a smoke duct gas in terminal exit of the exhaust port. In case of combustion of LLRS containing 99m TcO 4 or 131 INa, concentration of radioisotopes at the exhaust port showed less than legal concentration limit of these radioisotopes. In cases of combustion of LLRS containing 99m TcO 4 or 131 INa, decontamination factors of the incineration system were 120 and 1.1, respectively. (author)

  3. Implementing and measuring the level of laboratory service integration in a program setting in Nigeria.

    Science.gov (United States)

    Mbah, Henry; Negedu-Momoh, Olubunmi Ruth; Adedokun, Oluwasanmi; Ikani, Patrick Anibbe; Balogun, Oluseyi; Sanwo, Olusola; Ochei, Kingsley; Ekanem, Maurice; Torpey, Kwasi

    2014-01-01

    The surge of donor funds to fight HIV&AIDS epidemic inadvertently resulted in the setup of laboratories as parallel structures to rapidly respond to the identified need. However these parallel structures are a threat to the existing fragile laboratory systems. Laboratory service integration is critical to remedy this situation. This paper describes an approach to quantitatively measure and track integration of HIV-related laboratory services into the mainstream laboratory services and highlight some key intervention steps taken, to enhance service integration. A quantitative before-and-after study conducted in 122 Family Health International (FHI360) supported health facilities across Nigeria. A minimum service package was identified including management structure; trainings; equipment utilization and maintenance; information, commodity and quality management for laboratory integration. A check list was used to assess facilities at baseline and 3 months follow-up. Level of integration was assessed on an ordinal scale (0 = no integration, 1 = partial integration, 2 = full integration) for each service package. A composite score grading expressed as a percentage of total obtainable score of 14 was defined and used to classify facilities (≤ 80% FULL, 25% to 79% PARTIAL and laboratory systems were 64 (52.5%) and 0 (0.0%) at baseline, compared to 100 (82.0%) and 3 (2.4%) respectively at 3 months follow-up (p = 0.000). This project showcases our novel approach to measure the status of each laboratory on the integration continuum.

  4. Three-Dimensional Simulation of DRIE Process Based on the Narrow Band Level Set and Monte Carlo Method

    Directory of Open Access Journals (Sweden)

    Jia-Cheng Yu

    2018-02-01

    Full Text Available A three-dimensional topography simulation of deep reactive ion etching (DRIE is developed based on the narrow band level set method for surface evolution and Monte Carlo method for flux distribution. The advanced level set method is implemented to simulate the time-related movements of etched surface. In the meanwhile, accelerated by ray tracing algorithm, the Monte Carlo method incorporates all dominant physical and chemical mechanisms such as ion-enhanced etching, ballistic transport, ion scattering, and sidewall passivation. The modified models of charged particles and neutral particles are epitomized to determine the contributions of etching rate. The effects such as scalloping effect and lag effect are investigated in simulations and experiments. Besides, the quantitative analyses are conducted to measure the simulation error. Finally, this simulator will be served as an accurate prediction tool for some MEMS fabrications.

  5. A topology optimization method based on the level set method for the design of negative permeability dielectric metamaterials

    DEFF Research Database (Denmark)

    Otomori, Masaki; Yamada, Takayuki; Izui, Kazuhiro

    2012-01-01

    This paper presents a level set-based topology optimization method for the design of negative permeability dielectric metamaterials. Metamaterials are artificial materials that display extraordinary physical properties that are unavailable with natural materials. The aim of the formulated...... optimization problem is to find optimized layouts of a dielectric material that achieve negative permeability. The presence of grayscale areas in the optimized configurations critically affects the performance of metamaterials, positively as well as negatively, but configurations that contain grayscale areas...... are highly impractical from an engineering and manufacturing point of view. Therefore, a topology optimization method that can obtain clear optimized configurations is desirable. Here, a level set-based topology optimization method incorporating a fictitious interface energy is applied to a negative...

  6. Quasi-min-max Fuzzy MPC of UTSG Water Level Based on Off-Line Invariant Set

    Science.gov (United States)

    Liu, Xiangjie; Jiang, Di; Lee, Kwang Y.

    2015-10-01

    In a nuclear power plant, the water level of the U-tube steam generator (UTSG) must be maintained within a safe range. Traditional control methods encounter difficulties due to the complexity, strong nonlinearity and “swell and shrink” effects, especially at low power levels. A properly designed robust model predictive control can well solve this problem. In this paper, a quasi-min-max fuzzy model predictive controller is developed for controlling the constrained UTSG system. While the online computational burden could be quite large for the real-time control, a bank of ellipsoid invariant sets together with the corresponding feedback control laws are obtained by off-line solving linear matrix inequalities (LMIs). Based on the UTSG states, the online optimization is simplified as a constrained optimization problem with a bisection search for the corresponding ellipsoid invariant set. Simulation results are given to show the effectiveness of the proposed controller.

  7. Numerical simulation of interface movement in gas-liquid two-phase flows with Level Set method

    International Nuclear Information System (INIS)

    Li Huixiong; Chinese Academy of Sciences, Beijing; Deng Sheng; Chen Tingkuan; Zhao Jianfu; Wang Fei

    2005-01-01

    Numerical simulation of gas-liquid two-phase flow and heat transfer has been an attractive work for a quite long time, but still remains as a knotty difficulty due to the inherent complexities of the gas-liquid two-phase flow resulted from the existence of moving interfaces with topology changes. This paper reports the effort and the latest advances that have been made by the authors, with special emphasis on the methods for computing solutions to the advection equation of the Level set function, which is utilized to capture the moving interfaces in gas-liquid two-phase flows. Three different schemes, i.e. the simple finite difference scheme, the Superbee-TVD scheme and the 5-order WENO scheme in combination with the Runge-Kutta method are respectively applied to solve the advection equation of the Level Set. A numerical procedure based on the well-verified SIMPLER method is employed to numerically calculate the momentum equations of the two-phase flow. The above-mentioned three schemes are employed to simulate the movement of four typical interfaces under 5 typical flowing conditions. Analysis of the numerical results shows that the 5-order WENO scheme and the Superbee-TVD scheme are much better than the simple finite difference scheme, and the 5-order WENO scheme is the best to compute solutions to the advection equation of the Level Set. The 5-order WENO scheme will be employed as the main scheme to get solutions to the advection equations of the Level Set when gas-liquid two-phase flows are numerically studied in the future. (authors)

  8. Classification of Normal and Apoptotic Cells from Fluorescence Microscopy Images Using Generalized Polynomial Chaos and Level Set Function.

    Science.gov (United States)

    Du, Yuncheng; Budman, Hector M; Duever, Thomas A

    2016-06-01

    Accurate automated quantitative analysis of living cells based on fluorescence microscopy images can be very useful for fast evaluation of experimental outcomes and cell culture protocols. In this work, an algorithm is developed for fast differentiation of normal and apoptotic viable Chinese hamster ovary (CHO) cells. For effective segmentation of cell images, a stochastic segmentation algorithm is developed by combining a generalized polynomial chaos expansion with a level set function-based segmentation algorithm. This approach provides a probabilistic description of the segmented cellular regions along the boundary, from which it is possible to calculate morphological changes related to apoptosis, i.e., the curvature and length of a cell's boundary. These features are then used as inputs to a support vector machine (SVM) classifier that is trained to distinguish between normal and apoptotic viable states of CHO cell images. The use of morphological features obtained from the stochastic level set segmentation of cell images in combination with the trained SVM classifier is more efficient in terms of differentiation accuracy as compared with the original deterministic level set method.

  9. GPU accelerated edge-region based level set evolution constrained by 2D gray-scale histogram.

    Science.gov (United States)

    Balla-Arabé, Souleymane; Gao, Xinbo; Wang, Bin

    2013-07-01

    Due to its intrinsic nature which allows to easily handle complex shapes and topological changes, the level set method (LSM) has been widely used in image segmentation. Nevertheless, LSM is computationally expensive, which limits its applications in real-time systems. For this purpose, we propose a new level set algorithm, which uses simultaneously edge, region, and 2D histogram information in order to efficiently segment objects of interest in a given scene. The computational complexity of the proposed LSM is greatly reduced by using the highly parallelizable lattice Boltzmann method (LBM) with a body force to solve the level set equation (LSE). The body force is the link with image data and is defined from the proposed LSE. The proposed LSM is then implemented using an NVIDIA graphics processing units to fully take advantage of the LBM local nature. The new algorithm is effective, robust against noise, independent to the initial contour, fast, and highly parallelizable. The edge and region information enable to detect objects with and without edges, and the 2D histogram information enable the effectiveness of the method in a noisy environment. Experimental results on synthetic and real images demonstrate subjectively and objectively the performance of the proposed method.

  10. Comparison of different statistical methods for estimation of extreme sea levels with wave set-up contribution

    Science.gov (United States)

    Kergadallan, Xavier; Bernardara, Pietro; Benoit, Michel; Andreewsky, Marc; Weiss, Jérôme

    2013-04-01

    Estimating the probability of occurrence of extreme sea levels is a central issue for the protection of the coast. Return periods of sea level with wave set-up contribution are estimated here in one site : Cherbourg in France in the English Channel. The methodology follows two steps : the first one is computation of joint probability of simultaneous wave height and still sea level, the second one is interpretation of that joint probabilities to assess a sea level for a given return period. Two different approaches were evaluated to compute joint probability of simultaneous wave height and still sea level : the first one is multivariate extreme values distributions of logistic type in which all components of the variables become large simultaneously, the second one is conditional approach for multivariate extreme values in which only one component of the variables have to be large. Two different methods were applied to estimate sea level with wave set-up contribution for a given return period : Monte-Carlo simulation in which estimation is more accurate but needs higher calculation time and classical ocean engineering design contours of type inverse-FORM in which the method is simpler and allows more complex estimation of wave setup part (wave propagation to the coast for example). We compare results from the two different approaches with the two different methods. To be able to use both Monte-Carlo simulation and design contours methods, wave setup is estimated with an simple empirical formula. We show advantages of the conditional approach compared to the multivariate extreme values approach when extreme sea-level occurs when either surge or wave height is large. We discuss the validity of the ocean engineering design contours method which is an alternative when computation of sea levels is too complex to use Monte-Carlo simulation method.

  11. Evaluation of respiratory muscles activity by means of cross mutual information function at different levels of ventilatory effort.

    Science.gov (United States)

    Alonso, Joan Francesc; Mañanas, Miguel A; Hoyer, Dirk; Topor, Zbigniew L; Bruce, Eugene N

    2007-09-01

    Analysis of respiratory muscles activity is an effective technique for the study of pulmonary diseases such as obstructive sleep apnea syndrome (OSAS). Respiratory diseases, especially those associated with changes in the mechanical properties of the respiratory apparatus, are often associated with disruptions of the normally highly coordinated contractions of respiratory muscles. Due to the complexity of the respiratory control, the assessment of OSAS related dysfunctions by linear methods are not sufficient. Therefore, the objective of this study was the detection of diagnostically relevant nonlinear complex respiratory mechanisms. Two aims of this work were: (1) to assess coordination of respiratory muscles contractions through evaluation of interactions between respiratory signals and myographic signals through nonlinear analysis by means of cross mutual information function (CMIF); (2) to differentiate between functioning of respiratory muscles in patients with OSAS and in normal subjects. Electromyographic (EMG) and mechanomyographic (MMG) signals were recorded from three respiratory muscles: genioglossus, sternomastoid and diaphragm. Inspiratory pressure and flow were also acquired. All signals were measured in eight patients with OSAS and eight healthy subjects during an increased respiratory effort while awake. Several variables were defined and calculated from CMIF in order to describe correlation between signals. The results indicate different nonlinear couplings of respiratory muscles in both populations. This effect is progressively more evident at higher levels of respiratory effort.

  12. Assessment of Current Estimates of Global and Regional Mean Sea Level from the TOPEX/Poseidon, Jason-1, and OSTM 17-Year Record

    Science.gov (United States)

    Beckley, Brian D.; Ray, Richard D.; Lemoine, Frank G.; Zelensky, N. P.; Holmes, S. A.; Desal, Shailen D.; Brown, Shannon; Mitchum, G. T.; Jacob, Samuel; Luthcke, Scott B.

    2010-01-01

    The science value of satellite altimeter observations has grown dramatically over time as enabling models and technologies have increased the value of data acquired on both past and present missions. With the prospect of an observational time series extending into several decades from TOPEX/Poseidon through Jason-1 and the Ocean Surface Topography Mission (OSTM), and further in time with a future set of operational altimeters, researchers are pushing the bounds of current technology and modeling capability in order to monitor global sea level rate at an accuracy of a few tenths of a mm/yr. The measurement of mean sea-level change from satellite altimetry requires an extreme stability of the altimeter measurement system since the signal being measured is at the level of a few mm/yr. This means that the orbit and reference frame within which the altimeter measurements are situated, and the associated altimeter corrections, must be stable and accurate enough to permit a robust MSL estimate. Foremost, orbit quality and consistency are critical to satellite altimeter measurement accuracy. The orbit defines the altimeter reference frame, and orbit error directly affects the altimeter measurement. Orbit error remains a major component in the error budget of all past and present altimeter missions. For example, inconsistencies in the International Terrestrial Reference Frame (ITRF) used to produce the precision orbits at different times cause systematic inconsistencies to appear in the multimission time-frame between TOPEX and Jason-1, and can affect the intermission calibration of these data. In an effort to adhere to cross mission consistency, we have generated the full time series of orbits for TOPEX/Poseidon (TP), Jason-1, and OSTM based on recent improvements in the satellite force models, reference systems, and modeling strategies. The recent release of the entire revised Jason-1 Geophysical Data Records, and recalibration of the microwave radiometer correction also

  13. Single-step reinitialization and extending algorithms for level-set based multi-phase flow simulations

    Science.gov (United States)

    Fu, Lin; Hu, Xiangyu Y.; Adams, Nikolaus A.

    2017-12-01

    We propose efficient single-step formulations for reinitialization and extending algorithms, which are critical components of level-set based interface-tracking methods. The level-set field is reinitialized with a single-step (non iterative) "forward tracing" algorithm. A minimum set of cells is defined that describes the interface, and reinitialization employs only data from these cells. Fluid states are extrapolated or extended across the interface by a single-step "backward tracing" algorithm. Both algorithms, which are motivated by analogy to ray-tracing, avoid multiple block-boundary data exchanges that are inevitable for iterative reinitialization and extending approaches within a parallel-computing environment. The single-step algorithms are combined with a multi-resolution conservative sharp-interface method and validated by a wide range of benchmark test cases. We demonstrate that the proposed reinitialization method achieves second-order accuracy in conserving the volume of each phase. The interface location is invariant to reapplication of the single-step reinitialization. Generally, we observe smaller absolute errors than for standard iterative reinitialization on the same grid. The computational efficiency is higher than for the standard and typical high-order iterative reinitialization methods. We observe a 2- to 6-times efficiency improvement over the standard method for serial execution. The proposed single-step extending algorithm, which is commonly employed for assigning data to ghost cells with ghost-fluid or conservative interface interaction methods, shows about 10-times efficiency improvement over the standard method while maintaining same accuracy. Despite their simplicity, the proposed algorithms offer an efficient and robust alternative to iterative reinitialization and extending methods for level-set based multi-phase simulations.

  14. Bud development, flowering and fruit set of Moringa oleifera Lam. (Horseradish Tree as affected by various irrigation levels

    Directory of Open Access Journals (Sweden)

    Quintin Ernst Muhl

    2013-12-01

    Full Text Available Moringa oleifera is becoming increasingly popular as an industrial crop due to its multitude of useful attributes as water purifier, nutritional supplement and biofuel feedstock. Given its tolerance to sub-optimal growing conditions, most of the current and anticipated cultivation areas are in medium to low rainfall areas. This study aimed to assess the effect of various irrigation levels on floral initiation, flowering and fruit set. Three treatments namely, a 900 mm (900IT, 600 mm (600IT and 300 mm (300IT per annum irrigation treatment were administered through drip irrigation, simulating three total annual rainfall amounts. Individual inflorescences from each treatment were tagged during floral initiation and monitored throughout until fruit set. Flower bud initiation was highest at the 300IT and lowest at the 900IT for two consecutive growing seasons. Fruit set on the other hand, decreased with the decrease in irrigation treatment. Floral abortion, reduced pollen viability as well as moisture stress in the style were contributing factors to the reduction in fruiting/yield observed at the 300IT. Moderate water stress prior to floral initiation could stimulate flower initiation, however, this should be followed by sufficient irrigation to ensure good pollination, fruit set and yield.

  15. Mean relative sea level rise along the coasts of the China Seas from mid-20th to 21st centuries

    Science.gov (United States)

    Chen, Nan; Han, Guoqi; Yang, Jingsong

    2018-01-01

    Mean relative sea level (MRSL) rise has caused more frequent flooding in many parts of the world. The MRSL rise varies substantially from place to place. Here we use tide-gauge data and satellite measurements to examine past MRSL trends for the coasts of the China Seas. We then combine climate model output and satellite observations to provide MRSL projections in the 21st century. The MRSL trend based on tide-gauge data shows substantial regional variations, from 1 to 5 mm/yr. The vertical land motion (VLM) based on altimetry and tide-gauge (ATG) data indicates large land subsidence at some tide-gauge locations, consistent with the Global Positioning Systems (GPS)-based VLM but different significantly from small uplift estimated by a Glacial Isostatic Adjustment (GIA) model, which suggests other important factors causing the VLM instead of the GIA process. When GPS- or ATG-based VLM estimates are used, the projected MRSL rise between 1986-2005 and 2081-2100 at tide-gauge sites varies from 60 to 130 cm under the Representative Concentration Pathway 8.5 (RCP8.5) scenario of the Intergovernmental Panel on Climate Change (IPCC). Our projections are significantly larger than those of IPCC and other literature, as a result of accounting for the land subsidence derived from observations. Steric and dynamic ocean effects and land-ice melt effects are comparable (about 30 cm each) and do not vary much over the tide-gauge locations. The VLM effect varies from -10 to 60 cm. The projections between 1986-2005 and 2081-2100 under RCP4.5 show a similar spatial distribution to that under RCP8.5, with a smaller amount of rise by 18 cm on average for this region.

  16. Twentieth-century global-mean sea level rise: Is the whole greater than the sum of the parts?

    Science.gov (United States)

    Gregory, J.M.; White, N.J.; Church, J.A.; Bierkens, M.F.P.; Box, J.E.; Van den Broeke, M.R.; Cogley, J.G.; Fettweis, X.; Hanna, E.; Huybrechts, P.; Konikow, Leonard F.; Leclercq, P.W.; Marzeion, B.; Oerlemans, J.; Tamisiea, M.E.; Wada, Y.; Wake, L.M.; Van de Wal, R.S.W.

    2013-01-01

    Confidence in projections of global-mean sea level rise (GMSLR) depends on an ability to account for GMSLR during the twentieth century. There are contributions from ocean thermal expansion, mass loss from glaciers and ice sheets, groundwater extraction, and reservoir impoundment. Progress has been made toward solving the “enigma” of twentieth-century GMSLR, which is that the observed GMSLR has previously been found to exceed the sum of estimated contributions, especially for the earlier decades. The authors propose the following: thermal expansion simulated by climate models may previously have been underestimated because of their not including volcanic forcing in their control state; the rate of glacier mass loss was larger than previously estimated and was not smaller in the first half than in the second half of the century; the Greenland ice sheet could have made a positive contribution throughout the century; and groundwater depletion and reservoir impoundment, which are of opposite sign, may have been approximately equal in magnitude. It is possible to reconstruct the time series of GMSLR from the quantified contributions, apart from a constant residual term, which is small enough to be explained as a long-term contribution from the Antarctic ice sheet. The reconstructions account for the observation that the rate of GMSLR was not much larger during the last 50 years than during the twentieth century as a whole, despite the increasing anthropogenic forcing. Semiempirical methods for projecting GMSLR depend on the existence of a relationship between global climate change and the rate of GMSLR, but the implication of the authors' closure of the budget is that such a relationship is weak or absent during the twentieth century.

  17. Teamwork skills in actual, in situ, and in-center pediatric emergencies: performance levels across settings and perceptions of comparative educational impact.

    Science.gov (United States)

    Couto, Thomaz Bittencourt; Kerrey, Benjamin T; Taylor, Regina G; FitzGerald, Michael; Geis, Gary L

    2015-04-01

    Pediatric emergencies require effective teamwork. These skills are developed and demonstrated in actual emergencies and in simulated environments, including simulation centers (in center) and the real care environment (in situ). Our aims were to compare teamwork performance across these settings and to identify perceived educational strengths and weaknesses between simulated settings. We hypothesized that teamwork performance in actual emergencies and in situ simulations would be higher than for in-center simulations. A retrospective, video-based assessment of teamwork was performed in an academic, pediatric level 1 trauma center, using the Team Emergency Assessment Measure (TEAM) tool (range, 0-44) among emergency department providers (physicians, nurses, respiratory therapists, paramedics, patient care assistants, and pharmacists). A survey-based, cross-sectional assessment was conducted to determine provider perceptions regarding simulation training. One hundred thirty-two videos, 44 from each setting, were reviewed. Mean total TEAM scores were similar and high in all settings (31.2 actual, 31.1 in situ, and 32.3 in-center, P = 0.39). Of 236 providers, 154 (65%) responded to the survey. For teamwork training, in situ simulation was considered more realistic (59% vs. 10%) and more effective (45% vs. 15%) than in-center simulation. In a video-based study in an academic pediatric institution, ratings of teamwork were relatively high among actual resuscitations and 2 simulation settings, substantiating the influence of simulation-based training on instilling a culture of communication and teamwork. On the basis of survey results, providers favored the in situ setting for teamwork training and suggested an expansion of our existing in situ program.

  18. Glycated haemoglobin (HbA1c ) and fasting plasma glucose relationships in sea-level and high-altitude settings.

    Science.gov (United States)

    Bazo-Alvarez, J C; Quispe, R; Pillay, T D; Bernabé-Ortiz, A; Smeeth, L; Checkley, W; Gilman, R H; Málaga, G; Miranda, J J

    2017-06-01

    Higher haemoglobin levels and differences in glucose metabolism have been reported among high-altitude residents, which may influence the diagnostic performance of HbA 1c . This study explores the relationship between HbA 1c and fasting plasma glucose (FPG) in populations living at sea level and at an altitude of > 3000 m. Data from 3613 Peruvian adults without a known diagnosis of diabetes from sea-level and high-altitude settings were evaluated. Linear, quadratic and cubic regression models were performed adjusting for potential confounders. Receiver operating characteristic (ROC) curves were constructed and concordance between HbA 1c and FPG was assessed using a Kappa index. At sea level and high altitude, means were 13.5 and 16.7 g/dl (P > 0.05) for haemoglobin level; 41 and 40 mmol/mol (5.9% and 5.8%; P < 0.01) for HbA 1c ; and 5.8 and 5.1 mmol/l (105 and 91.3 mg/dl; P < 0.001) for FPG, respectively. The adjusted relationship between HbA 1c and FPG was quadratic at sea level and linear at high altitude. Adjusted models showed that, to predict an HbA 1c value of 48 mmol/mol (6.5%), the corresponding mean FPG values at sea level and high altitude were 6.6 and 14.8 mmol/l (120 and 266 mg/dl), respectively. An HbA 1c cut-off of 48 mmol/mol (6.5%) had a sensitivity for high FPG of 87.3% (95% confidence interval (95% CI) 76.5 to 94.4) at sea level and 40.9% (95% CI 20.7 to 63.6) at high altitude. The relationship between HbA 1c and FPG is less clear at high altitude than at sea level. Caution is warranted when using HbA 1c to diagnose diabetes mellitus in this setting. © 2017 The Authors. Diabetic Medicine published by John Wiley & Sons Ltd on behalf of Diabetes UK.

  19. Improving district level health planning and priority setting in Tanzania through implementing accountability for reasonableness framework: Perceptions of stakeholders.

    Science.gov (United States)

    Maluka, Stephen; Kamuzora, Peter; San Sebastián, Miguel; Byskov, Jens; Ndawi, Benedict; Hurtig, Anna-Karin

    2010-12-01

    In 2006, researchers and decision-makers launched a five-year project - Response to Accountable Priority Setting for Trust in Health Systems (REACT) - to improve planning and priority-setting through implementing the Accountability for Reasonableness framework in Mbarali District, Tanzania. The objective of this paper is to explore the acceptability of Accountability for Reasonableness from the perspectives of the Council Health Management Team, local government officials, health workforce and members of user boards and committees. Individual interviews were carried out with different categories of actors and stakeholders in the district. The interview guide consisted of a series of questions, asking respondents to describe their perceptions regarding each condition of the Accountability for Reasonableness framework in terms of priority setting. Interviews were analysed using thematic framework analysis. Documentary data were used to support, verify and highlight the key issues that emerged. Almost all stakeholders viewed Accountability for Reasonableness as an important and feasible approach for improving priority-setting and health service delivery in their context. However, a few aspects of Accountability for Reasonableness were seen as too difficult to implement given the socio-political conditions and traditions in Tanzania. Respondents mentioned: budget ceilings and guidelines, low level of public awareness, unreliable and untimely funding, as well as the limited capacity of the district to generate local resources as the major contextual factors that hampered the full implementation of the framework in their context. This study was one of the first assessments of the applicability of Accountability for Reasonableness in health care priority-setting in Tanzania. The analysis, overall, suggests that the Accountability for Reasonableness framework could be an important tool for improving priority-setting processes in the contexts of resource-poor settings

  20. The Two-Level Theory of Verb Meaning: An Approach to Integrating the Semantics of Action with the Mirror Neuron System

    Science.gov (United States)

    Kemmerer, David; Gonzalez-Castillo, Javier

    2010-01-01

    Verbs have two separate levels of meaning. One level reflects the uniqueness of every verb and is called the "root". The other level consists of a more austere representation that is shared by all the verbs in a given class and is called the "event structure template". We explore the following hypotheses about how, with specific reference to the…

  1. TCTE Level 3 Total Solar Irradiance 6-Hour Means V002 (TCTE3TSI6) at GES DISC

    Data.gov (United States)

    National Aeronautics and Space Administration — The Total Solar Irradiance (TSI) Calibration Transfer Experiment (TCTE) data set TCTE3TSI6 contains 6-hour averaged total solar irradiance (a.k.a solar constant)...

  2. Accurate prediction of complex free surface flow around a high speed craft using a single-phase level set method

    Science.gov (United States)

    Broglia, Riccardo; Durante, Danilo

    2017-11-01

    This paper focuses on the analysis of a challenging free surface flow problem involving a surface vessel moving at high speeds, or planing. The investigation is performed using a general purpose high Reynolds free surface solver developed at CNR-INSEAN. The methodology is based on a second order finite volume discretization of the unsteady Reynolds-averaged Navier-Stokes equations (Di Mascio et al. in A second order Godunov—type scheme for naval hydrodynamics, Kluwer Academic/Plenum Publishers, Dordrecht, pp 253-261, 2001; Proceedings of 16th international offshore and polar engineering conference, San Francisco, CA, USA, 2006; J Mar Sci Technol 14:19-29, 2009); air/water interface dynamics is accurately modeled by a non standard level set approach (Di Mascio et al. in Comput Fluids 36(5):868-886, 2007a), known as the single-phase level set method. In this algorithm the governing equations are solved only in the water phase, whereas the numerical domain in the air phase is used for a suitable extension of the fluid dynamic variables. The level set function is used to track the free surface evolution; dynamic boundary conditions are enforced directly on the interface. This approach allows to accurately predict the evolution of the free surface even in the presence of violent breaking waves phenomena, maintaining the interface sharp, without any need to smear out the fluid properties across the two phases. This paper is aimed at the prediction of the complex free-surface flow field generated by a deep-V planing boat at medium and high Froude numbers (from 0.6 up to 1.2). In the present work, the planing hull is treated as a two-degree-of-freedom rigid object. Flow field is characterized by the presence of thin water sheets, several energetic breaking waves and plungings. The computational results include convergence of the trim angle, sinkage and resistance under grid refinement; high-quality experimental data are used for the purposes of validation, allowing to

  3. Ultrasonic scalpel causes greater depth of soft tissue necrosis compared to monopolar electrocautery at standard power level settings in a pig model.

    Science.gov (United States)

    Homayounfar, Kia; Meis, Johanna; Jung, Klaus; Klosterhalfen, Bernd; Sprenger, Thilo; Conradi, Lena-Christin; Langer, Claus; Becker, Heinz

    2012-02-23

    Ultrasonic scalpel (UC) and monopolar electrocautery (ME) are common tools for soft tissue dissection. However, morphological data on the related tissue alteration are discordant. We developed an automatic device for standardized sample excision and compared quality and depth of morphological changes caused by UC and ME in a pig model. 100 tissue samples (5 × 3 cm) of the abdominal wall were excised in 16 pigs. Excisions were randomly performed manually or by using the self-constructed automatic device at standard power levels (60 W cutting in ME, level 5 in UC) for abdominal surgery. Quality of tissue alteration and depth of coagulation necrosis were examined histopathologically. Device (UC vs. ME) and mode (manually vs. automatic) effects were studied by two-way analysis of variance at a significance level of 5%. At the investigated power level settings UC and ME induced qualitatively similar coagulation necroses. Mean depth of necrosis was 450.4 ± 457.8 μm for manual UC and 553.5 ± 326.9 μm for automatic UC versus 149.0 ± 74.3 μm for manual ME and 257.6 ± 119.4 μm for automatic ME. Coagulation necrosis was significantly deeper (p power levels.

  4. APPLICATION OF ROUGH SET THEORY TO MAINTENANCE LEVEL DECISION-MAKING FOR AERO-ENGINE MODULES BASED ON INCREMENTAL KNOWLEDGE LEARNING

    Institute of Scientific and Technical Information of China (English)

    陆晓华; 左洪福; 蔡景

    2013-01-01

    The maintenance of an aero-engine usually includes three levels ,and the maintenance cost and period greatly differ depending on the different maintenance levels .To plan a reasonable maintenance budget program , airlines would like to predict the maintenance level of aero-engine before repairing in terms of performance parame-ters ,which can provide more economic benefits .The maintenance level decision rules are mined using the histori-cal maintenance data of a civil aero-engine based on the rough set theory ,and a variety of possible models of upda-ting rules produced by newly increased maintenance cases added to the historical maintenance case database are in-vestigated by the means of incremental machine learning .The continuously updated rules can provide reasonable guidance suggestions for engineers and decision support for planning a maintenance budget program before repai-ring .The results of an example show that the decision rules become more typical and robust ,and they are more accurate to predict the maintenance level of an aero-engine module as the maintenance data increase ,which illus-trates the feasibility of the represented method .

  5. The Mean as Balance Point

    Science.gov (United States)

    O'Dell, Robin S.

    2012-01-01

    There are two primary interpretations of the mean: as a leveler of data (Uccellini 1996, pp. 113-114) and as a balance point of a data set. Typically, both interpretations of the mean are ignored in elementary school and middle school curricula. They are replaced with a rote emphasis on calculation using the standard algorithm. When students are…

  6. Novel room-temperature-setting phosphate ceramics for stabilizing combustion products and low-level mixed wastes

    International Nuclear Information System (INIS)

    Wagh, A.S.; Singh, D.

    1994-01-01

    Argonne National Laboratory, with support from the Office of Technology in the US Department of Energy (DOE), has developed a new process employing novel, chemically bonded ceramic materials to stabilize secondary waste streams. Such waste streams result from the thermal processes used to stabilize low-level, mixed wastes. The process will help the electric power industry treat its combustion and low-level mixed wastes. The ceramic materials are strong, dense, leach-resistant, and inexpensive to fabricate. The room-temperature-setting process allows stabilization of volatile components containing lead, mercury, cadmium, chromium, and nickel. The process also provides effective stabilization of fossil fuel combustion products. It is most suitable for treating fly and bottom ashes

  7. Automated volume analysis of head and neck lesions on CT scans using 3D level set segmentation

    International Nuclear Information System (INIS)

    Street, Ethan; Hadjiiski, Lubomir; Sahiner, Berkman; Gujar, Sachin; Ibrahim, Mohannad; Mukherji, Suresh K.; Chan, Heang-Ping

    2007-01-01

    The authors have developed a semiautomatic system for segmentation of a diverse set of lesions in head and neck CT scans. The system takes as input an approximate bounding box, and uses a multistage level set to perform the final segmentation. A data set consisting of 69 lesions marked on 33 scans from 23 patients was used to evaluate the performance of the system. The contours from automatic segmentation were compared to both 2D and 3D gold standard contours manually drawn by three experienced radiologists. Three performance metric measures were used for the comparison. In addition, a radiologist provided quality ratings on a 1 to 10 scale for all of the automatic segmentations. For this pilot study, the authors observed that the differences between the automatic and gold standard contours were larger than the interobserver differences. However, the system performed comparably to the radiologists, achieving an average area intersection ratio of 85.4% compared to an average of 91.2% between two radiologists. The average absolute area error was 21.1% compared to 10.8%, and the average 2D distance was 1.38 mm compared to 0.84 mm between the radiologists. In addition, the quality rating data showed that, despite the very lax assumptions made on the lesion characteristics in designing the system, the automatic contours approximated many of the lesions very well

  8. Simulation to aid in interpreting biological relevance and setting of population-level protection goals for risk assessment of pesticides.

    Science.gov (United States)

    Topping, Christopher John; Luttik, Robert

    2017-10-01

    Specific protection goals (SPGs) comprise an explicit expression of the environmental components that need protection and the maximum impacts that can be tolerated. SPGs are set by risk managers and are typically based on protecting populations or functions. However, the measurable endpoints available to risk managers, at least for vertebrates, are typically laboratory tests. We demonstrate, using the example of eggshell thinning in skylarks, how simulation can be used to place laboratory endpoints in context of population-level effects as an aid to setting the SPGs. We develop explanatory scenarios investigating the impact of different assumptions of eggshell thinning on skylark population size, density and distribution in 10 Danish landscapes, chosen to represent the range of typical Danish agricultural conditions. Landscape and timing of application of the pesticide were found to be the most critical factors to consider in the impact assessment. Consequently, a regulatory scenario of monoculture spring barley with an early spray treatment eliciting the eggshell thinning effect was applied using concentrations eliciting effects of zero to 100% in steps of 5%. Setting the SPGs requires balancing scientific, social and political realities. However, the provision of clear and detailed options such as those from comprehensive simulation results can inform the decision process by improving transparency and by putting the more abstract testing data into the context of real-world impacts. Copyright © 2017 Elsevier Inc. All rights reserved.

  9. MERRA 2D IAU Ocean Surface Diagnostic, Single Level, Monthly Mean (2/3x1/2L1) V5.2.0

    Data.gov (United States)

    National Aeronautics and Space Administration — The MATMNXOCN or tavgM_2d_ocn_Nx data product is the MERRA Data Assimilation System 2-Dimensional ocean surface single-level diagnostics that is monthly mean...

  10. Level-set reconstruction algorithm for ultrafast limited-angle X-ray computed tomography of two-phase flows.

    Science.gov (United States)

    Bieberle, M; Hampel, U

    2015-06-13

    Tomographic image reconstruction is based on recovering an object distribution from its projections, which have been acquired from all angular views around the object. If the angular range is limited to less than 180° of parallel projections, typical reconstruction artefacts arise when using standard algorithms. To compensate for this, specialized algorithms using a priori information about the object need to be applied. The application behind this work is ultrafast limited-angle X-ray computed tomography of two-phase flows. Here, only a binary distribution of the two phases needs to be reconstructed, which reduces the complexity of the inverse problem. To solve it, a new reconstruction algorithm (LSR) based on the level-set method is proposed. It includes one force function term accounting for matching the projection data and one incorporating a curvature-dependent smoothing of the phase boundary. The algorithm has been validated using simulated as well as measured projections of known structures, and its performance has been compared to the algebraic reconstruction technique and a binary derivative of it. The validation as well as the application of the level-set reconstruction on a dynamic two-phase flow demonstrated its applicability and its advantages over other reconstruction algorithms. © 2015 The Author(s) Published by the Royal Society. All rights reserved.

  11. Effect of a uniform magnetic field on dielectric two-phase bubbly flows using the level set method

    International Nuclear Information System (INIS)

    Ansari, M.R.; Hadidi, A.; Nimvari, M.E.

    2012-01-01

    In this study, the behavior of a single bubble in a dielectric viscous fluid under a uniform magnetic field has been simulated numerically using the Level Set method in two-phase bubbly flow. The two-phase bubbly flow was considered to be laminar and homogeneous. Deformation of the bubble was considered to be due to buoyancy and magnetic forces induced from the external applied magnetic field. A computer code was developed to solve the problem using the flow field, the interface of two phases, and the magnetic field. The Finite Volume method was applied using the SIMPLE algorithm to discretize the governing equations. Using this algorithm enables us to calculate the pressure parameter, which has been eliminated by previous researchers because of the complexity of the two-phase flow. The finite difference method was used to solve the magnetic field equation. The results outlined in the present study agree well with the existing experimental data and numerical results. These results show that the magnetic field affects and controls the shape, size, velocity, and location of the bubble. - Highlights: ►A bubble behavior was simulated numerically. ► A single bubble behavior was considered in a dielectric viscous fluid. ► A uniform magnetic field is used to study a bubble behavior. ► Deformation of the bubble was considered using the Level Set method. ► The magnetic field affects the shape, size, velocity, and location of the bubble.

  12. Hybridization and crystal-field effects in Kondo insulators studied by means of core-level spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Strigari, Fabio

    2015-04-13

    and even for symmetries lower than tetragonal. In addition to that, HAXPES measurements on the CeM{sub 2}Al{sub 10} series are presented. A common technique for studying hybridization effects in rare earths, and their electronic structure in general, is photoelectron spectroscopy in the soft X-ray range (hv ≤ 1.5 keV). However, in this energy region surface effects are known to matter so that the picture about the hybridization interaction might be distorted with respect to the bulk. The use of hard X-rays (hν=5-10 keV) guarantees a sufficiently large probing depth for obtaining information about the actual bulk electronic structure. In a detailed quantitative analysis of HAXPES 3d core level spectra - using a combination of full multiplet calculations and a configuration interaction model (fm-CI model) - the hybridization strength can be quantified. The XAS results show that the CEF ground states of CeRu{sub 2}Al{sub 10} and CeOs{sub 2}Al are very similar, while it is clearly different for the non-ordering system CeFe{sub 2}Al{sub 10}. The CEF description nicely explains the magnetic anisotropy observed in susceptibility data and to a large extent the small ordered moments along the c axis. We provide a reliable quantitative description of the CEF ground state of the CeM{sub 2}Al{sub 10} compounds. Furthermore, the analysis of the HAXPES data in the fm-CI model allows to quantify the intermediate 4f valence and establishes that the exchange interaction increases within the series from Ru to Os to Fe. A substantial amount of Kondo screening is shown to be present even in the magnetically ordered Ru and Os compounds. The polarized XAS study on CeNiSn demonstrates that the monoclinic CEF is well described in a trigonal approximation, and the determined 4f ground-state wave function is consistent with results from inelastic neutron scattering for Cu-doped CeNiSn. Moreover, the systematic investigation of the CeRh{sub 1-x}Ir{sub x}In{sub 5} substitution series by means

  13. River flow controls on tides an tide-mean water level profiles in a tidel freshwater river

    NARCIS (Netherlands)

    Sassi, M.G.; Hoitink, A.J.F.

    2013-01-01

    [1] Tidal rivers feature oscillatory and steady gradients in the water surface, controlled by interactions between river flow and tides. The river discharge attenuates the tidal motion, and tidal motion increases tidal-mean friction in the river, which may act as a barrier to the river discharge.

  14. Electronic structure and core-level spectra of light actinide dioxides in the dynamical mean-field theory

    Czech Academy of Sciences Publication Activity Database

    Kolorenč, Jindřich; Shick, Alexander; Lichtenstein, A.I.

    2015-01-01

    Roč. 92, č. 8 (2015), "085125-1"-"085125-10" ISSN 1098-0121 R&D Projects: GA ČR GC15-05872J Institutional support: RVO:68378271 Keywords : electronic-structure calculations * dynamical mean-field theory * Mott insulators * actinides * oxides * photoemission Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 3.736, year: 2014

  15. “What do you mean I can’t just use Google?” Information Literacy in an Academic Setting

    OpenAIRE

    Laura Thorne

    2012-01-01

  1. Computational Fluid Dynamics Analysis of Cold Plasma Plume Mixing with Blood Using Level Set Method Coupled with Heat Transfer

    Directory of Open Access Journals (Sweden)

    Mehrdad Shahmohammadi Beni

    2017-06-01

    Full Text Available Cold plasmas were proposed for treatment of leukemia. In the present work, conceptual designs of mixing chambers that increased the contact between the two fluids (plasma and blood through addition of obstacles within rectangular-block-shaped chambers were proposed and the dynamic mixing between the plasma and blood were studied using the level set method coupled with heat transfer. Enhancement of mixing between blood and plasma in the presence of obstacles was demonstrated. Continuous tracking of fluid mixing with determination of temperature distributions was enabled by the present model, which would be a useful tool for future development of cold plasma devices for treatment of blood-related diseases such as leukemia.

  2. Does More Mean Less? The Male/Female Wage Gap and the Proportion of Females at the Establishment Level

    DEFF Research Database (Denmark)

    Reilly, Kevin T.; Wirjanto, Tony S.

    1998-01-01

    of the gap in log wages between men and women. Due to an inadequacy of the traditional method of decomposing wages when examining an affirmative action program, a new method of decomposition is developed: the characteristic wage decomposition. The results suggest that an employment equity program will reduce......This paper examines the effect of the proportionof females in the establishment on the male/female wage gap and the effectiveness of an affirmaive action program in reducing this gap. A unique data set makes this paper possible since it has information on both individuals and the establishments...... the male/female log wage gap by 20 percent....

  3. Effect of culture levels, ultrafiltered retentate addition, total solid levels and heat treatments on quality improvement of buffalo milk plain set yoghurt.

    Science.gov (United States)

    Yadav, Vijesh; Gupta, Vijay Kumar; Meena, Ganga Sahay

    2018-05-01

    Studied the effect of culture (2, 2.5 and 3%), ultrafiltered (UF) retentate addition (0, 11, 18%), total milk solids (13, 13.50, 14%) and heat treatments (80 and 85 °C/30 min) on the change in pH and titratable acidity (TA), sensory scores and rheological parameters of yoghurt. With 3% culture levels, the required TA (0.90% LA) was achieved in minimum 6 h incubation. With an increase in UF retentate addition, there was observed a highly significant decrease in overall acceptability, body and texture and colour and appearance scores, but there was highly significant increase in rheological parameters of yoghurt samples. Yoghurt made from even 13.75% total solids containing nil UF retentate was observed to be sufficiently firm by the sensory panel. Most of the sensory attributes of yoghurt made with 13.50% total solids were significantly better than yoghurt prepared with either 13 or 14% total solids. Standardised milk heated to 85 °C/30 min resulted in significantly better overall acceptability in yoghurt. Overall acceptability of optimised yoghurt was significantly better than a branded market sample. UF retentate addition adversely affected yoghurt quality, whereas optimization of culture levels, totals milk solids and others process parameters noticeably improved the quality of plain set yoghurt with a shelf life of 15 days at 4 °C.

  4. Social Relations at the Collective Level: The Meaning and Measurement of Collective Control in Research on the Psychosocial Work Environment

    Directory of Open Access Journals (Sweden)

    Per Øystein Saksvik

    2013-09-01

    Full Text Available In this article, we suggest that organizational-level social relations should be defined and measured as workplace norms. We base this argument on new research on the components of the psychosocial work environment and on the availability of new techniques for measuring and analyzing workplace norms as organizational properties. Workplace norms emerge from interactions and negotiations among organizational actors, through which patterns of behavior, attitudes, and perspectives become defined as legitimate. This is an underestimated dimension of the psychosocial work environment that should be assessed with two types of data: self-reports by employees of their experiences in the workplace (task-level control and self-reports by employees and employers of collective or group-level norms. Hierarchical linear modeling is an especially useful tool for analyzing the relationships between workplace norms and different organizational outcomes because it allows researchers to separate the effects of individual-level variables from group or organizational-level factors. Our approach is anchored in the Nordic perspective of the work environment developed over the past 50 years.

  5. Calculations of standard-Higgs-boson production cross sections in e+e- collisions by means of a reasonable set of parameters

    International Nuclear Information System (INIS)

    Biyajima, M.; Shirane, K.; Terazawa, O.

    1987-01-01

    We calculate cross sections for production of the standard Higgs boson in e + e - collisions and compare our results with those of several authors. It is found that there are appreciable differences among them which can be attributed to the coupling constants used, α(0) ( = (1/137) and G/sub F/. We also observe that cross sections depend on the magnitudes of the total width of the Z particle. The use of a reasonable set of parameters in calculations is emphasized

  6. Understanding the meaning and role of gifts given to Ugandan mothers in maternity care settings: 'The help they give when they've seen how different you are'.

    Science.gov (United States)

    Rudrum, Sarah; Brown, Helen; Oliffe, John L

    2016-11-01

    The provision of gifts to new mothers in Uganda is laden with significance that varies by the social location of the giver and receiver and the context and conditions under which the gift is made available. Here, we examine the act of gift giving and receiving within a Ugandan maternity care setting, describing the connections between these material objects and social relations. A study investigating the social organisation of maternity care in post-conflict northern Uganda found that gift-giving to new mothers functioned to create a material and discursive context wherein women's desire to access these goods was leveraged to create an incentive to attend formal maternity care during pregnancy and for delivery. In this article we describe the material and discursive processes surrounding gift-giving to new mothers in this global South health care setting. This article contributes critical analyses of the function of gifts in healthcare settings as constructing shared identities, social differences and normative values about health citizenship, and an incentive politic that affects equitable access to maternity care. Drawing on intersectional theory and analysis of how specific practices function ideologically to reward or incentivise pregnant women, we integrate material culture studies into the sociology of women's reproductive health. © 2016 Foundation for the Sociology of Health & Illness.

  7. New Constraints from the Seychelles on the Timing and Magnitude of Peak Global Mean Sea Level during the Last Interglacial

    Science.gov (United States)

    Vyverberg, K.; Dechnik, B.; Dutton, A.; Webster, J.; Zwartz, D.; Edwards, R. L.

    2016-12-01

    Projecting the rate of future sea-level rise remains a primary challenge associated with continued climate change. However, uncertainties remain in our understanding of the rate of polar ice sheet retreat in warmer-than-present climates. To address this issue, we present a new sea level reconstruction from the tectonically stable granitic Seychelles based on Last Interglacial coral ages and elevations within their sedimentary and stratigraphic context, including estimates of paleo-water depth based on newly defined coralgal assemblages. The reef facies analyzed here has a narrow and shallow paleowater depth range (dwelling barnacles. These disturbance layers may have been generated through internal reef processes and/or external agents, including coral disease, bleaching, predation, hurricanes, or sub-aerial exposure. In total, these new observations provide improved constraints on the timing, magnitude, and rates of sea-level rise during the Last Interglacial.

  8. A Rotating Speed Controller Design Method for Power Levelling by Means of Inertia Energy in Wind Power Systems

    DEFF Research Database (Denmark)

    Qin, Zian; Blaabjerg, Frede; Loh, Poh Chiang

    2015-01-01

    Power fluctuation caused by wind speed variations may be harmful for the stability of the power system as well as the reliability of the wind power converter, since it may induce thermal excursions in the solder joints of the power modules. Using the wind turbine rotor inertia energy for power...... in the frequency domain for power leveling. Moreover, the impact of other parameters on power leveling, including the time constant of maximum power point tracking (MPPT) and the rotor inertia, are also studied. With the proposed optimal design, the power fluctuations are mitigated as much as possible, while...

  9. Set-up and first operation of a plasma oven for treatment of low level radioactive wastes

    Directory of Open Access Journals (Sweden)

    Nachtrodt Frederik

    2014-01-01

    Full Text Available An experimental device for plasma treatment of low and intermediate level radioactive waste was built and tested in several design variations. The laboratory device is designed with the intention to study the general effects and difficulties in a plasma incineration set-up for the further future development of a larger scale pilot plant. The key part of the device consists of a novel microwave plasma torch driven by 200 W electric power, and operating at atmospheric pressure. It is a specific design characteristic of the torch that a high peak temperature can be reached with a low power input compared to other plasma torches. Experiments have been carried out to analyze the effect of the plasma on materials typical for operational low-level wastes. In some preliminary cold tests the behavior of stable volatile species e. g., caesium was investigated by TXRF measurements of material collected from the oven walls and the filtered off-gas. The results help in improving and scaling up the existing design and in understanding the effects for a pilot plant, especially for the off-gas collection and treatment.

  10. The evaluation of mean platelet volume levels in patients with primary and secondary Raynaud’s Phenomenon

    Directory of Open Access Journals (Sweden)

    Mehmet Erdem Memetoğlu

    2014-03-01

    Full Text Available Background — Mean platelet volume (MPV is an indicator of platelet activation. The pathophysiology of the primary and secondary Raynaud’s Phenomenon (RP have not been completely established. The aim of this study was to investigate the relationship between MPV and RP. Materials and Methods — Our study was a prospective randomized study carried out from January 2011 to March 2012. The study group consisted of 39 patients: 27 (70% patients having primary, 12 (30% patients having secondary RP. An age-, gender-, and body mass index-matched control group consisted of 40 healthy participants. We compared the MPV in patients with RP and control participants statistically. Results — MPV of RP group was 8.79±1.37 femtoliter (fL while MPV of control group was 8.39±1.36 fL. Comparison of MPV of RP group and control group showed no difference (p=0.274. The mean of MPV was significantly higher among patients with secondary RP (9.76±1.68 fl when compared with patients with primary RP (8.37±0.96 fl (p=0.018. Conclusion — The results of our study suggest that MPV may be used as a marker in secondary RP.

  11. The Hb E (HBB: c.79G>A), Mean Corpuscular Volume, Mean Corpuscular Hemoglobin Cutoff Points in Double Heterozygous Hb E/- -SEA α-Thalassemia-1 Carriers are Dependent on Hemoglobin Levels.

    Science.gov (United States)

    Leckngam, Prapapun; Limweeraprajak, Ektong; Kiewkarnkha, Tiemjan; Tatu, Thanusak

    2017-01-01

    Identifying double heterozygosities in Hb E (HBB: c.79 G>A)/- - SEA (Southeast Asian) (α-thalassemia-1) (α-thal-1) in patients first diagnosed as carrying Hb E is important in thalassemia control. Low Hb E, mean corpuscular volume (MCV) and mean corpuscular hemoglobin (Hb) (MCH) levels have been observed in this double heterozygosity. However, the cutoff points of these parameters have never been systematically established. Here, we analyzed Hb E and red blood cell (RBC) parameters in 372 Hb E patients grouped by Hb levels, by the status of - - SEA and -α 3.7 (α-thal-2; rightward) deletions, to establish the cutoff points. Then, the established cutoff points were evaluated in 184 Hb E patients. It was found that the cutoff points of Hb E, MCV, MCH were significantly dependent on the Hb levels. In the group having Hb levels Hb E, MCV and MCH were 21.2%, 64.9 fL and 21.0 pg, respectively, and were 25.6%, 72.8 fL and 23.9 pg, respectively, in the group having Hb levels 10.0-11.9 g/dL. Finally, in the group having Hb levels ≥12.0 g/dL, the cutoff points of Hb E, MCV and MCH were 27.1%, 76.7 fL and 25.3 pg, respectively. Thus, to screen for the double heterozygous Hb E/- - SEA anomaly in patients initially diagnosed as carrying Hb E, the Hb levels must be taken into account in choosing the suitable cutoff points of these three parameters.

  12. Biomonitoring of airborne inorganic and organic pollutants by means of pine tree barks. II. Deposition types and impact levels

    International Nuclear Information System (INIS)

    Schulz, H.; Schulz, U.; Huhn, G.; Schuermann, G.

    2000-01-01

    A total of 273 pine bark samples collected from various pine stands in Central and East Germany, South Norway, Poland, and Russia was analyzed with respect to 20 inorganic and organic substances (sulphate, nitrate, ammonia, calcium, 3 PAHs, 5 heavy metals, 9 other elements). Multivariate statistics were applied to characterize the multiple exposure of airborne pollutants in terms of major sources, deposition types and impact levels. The former was studied with factor analysis, whilst the latter two were addressed by applying cluster and discrimination analysis. Factor analysis of the concentration values suggest separation into three factors with the following characteristics: Factor 1 shows higher contributions from sulphate and calcium, factor 2 from fluoranthene, benzo(a)pyrene as well as from pyrene, and factor 3 from nitrate and ammonia, respectively. According to results from the cluster analysis, three major deposition types can be identified: 'Industry and House heating', 'Motor traffic', and 'Agriculture'. The first deposition type is characterized by high contents of sulphate and calcium. The other two deposition types contain specific composition profiles for nitrogen-containing components and PAHs. Impact levels are separately classified with the characteristic variables of main deposition types. Finally, discriminant analysis is used to allocate new bark samples to the classified deposition types and impact levels. The results demonstrate the usefulness of multivariate statistical techniques to characterize and evaluate multiple exposure patterns of airborne pollutants in forest ecosystems. (author)

  13. Paleo sea-level changes and relative sea-level indicators: Precise measurements, indicative meaning and glacial isostatic adjustment perspectives from Mallorca (Western Mediterranean)

    NARCIS (Netherlands)

    Lorscheid, T; Stocchi, P.; Casella, E.; Gómez-Pujolf, L.; Vacchi, M.; Mann, T.; Rovere, A.

    2017-01-01

    Paleo relative sea-level (RSL) indicators formed during the Marine Isotope Stage (MIS) 5e have been reported bya large number of studies worldwide. Despite this, three main aspects are seldom reported: (1) use of high-precisionsurvey techniques applied to MIS 5e RSL indicators; (2) application of

  14. 准确设置会计科目的意义与方法%The Meaning and Methods of Setting up Accounting Subject Accurately

    Institute of Scientific and Technical Information of China (English)

    刘海; 孙胜

    2013-01-01

      管理会计的产生与发展,是会计发展史上的一次伟大变革,它让会计工作的价值得到了有效地升华。而恰当的设置会计科目,对经济数据进行有效地分类、归集自然成为了会计信息管理的核心工作。本文从准确设置会计科目的重要意义、会计科目设置原则、会计科目设置方法方面进行了论述,为企业财务管理与经济管理提供参考依据。%The origin and development of management accounting is a great change in the history of the accounting development, it gives effective sublimation for the value of the accounting work. Proper setting up accounting subject, effectively sorting and collecting the economic data has become the core work of the accounting information management. This article discussed from the significance, principle and the method of accurately setting up accounting subject, and provided a reference for enterprise financial management and economic management.

  15. An optimized process flow for rapid segmentation of cortical bones of the craniofacial skeleton using the level-set method.

    Science.gov (United States)

    Szwedowski, T D; Fialkov, J; Pakdel, A; Whyne, C M

    2013-01-01

    Accurate representation of skeletal structures is essential for quantifying structural integrity, for developing accurate models, for improving patient-specific implant design and in image-guided surgery applications. The complex morphology of thin cortical structures of the craniofacial skeleton (CFS) represents a significant challenge with respect to accurate bony segmentation. This technical study presents optimized processing steps to segment the three-dimensional (3D) geometry of thin cortical bone structures from CT images. In this procedure, anoisotropic filtering and a connected components scheme were utilized to isolate and enhance the internal boundaries between craniofacial cortical and trabecular bone. Subsequently, the shell-like nature of cortical bone was exploited using boundary-tracking level-set methods with optimized parameters determined from large-scale sensitivity analysis. The process was applied to clinical CT images acquired from two cadaveric CFSs. The accuracy of the automated segmentations was determined based on their volumetric concurrencies with visually optimized manual segmentations, without statistical appraisal. The full CFSs demonstrated volumetric concurrencies of 0.904 and 0.719; accuracy increased to concurrencies of 0.936 and 0.846 when considering only the maxillary region. The highly automated approach presented here is able to segment the cortical shell and trabecular boundaries of the CFS in clinical CT images. The results indicate that initial scan resolution and cortical-trabecular bone contrast may impact performance. Future application of these steps to larger data sets will enable the determination of the method's sensitivity to differences in image quality and CFS morphology.

  16. Ultrasonic scalpel causes greater depth of soft tissue necrosis compared to monopolar electrocautery at standard power level settings in a pig model

    Science.gov (United States)

    2012-01-01

    Background Ultrasonic scalpel (UC) and monopolar electrocautery (ME) are common tools for soft tissue dissection. However, morphological data on the related tissue alteration are discordant. We developed an automatic device for standardized sample excision and compared quality and depth of morphological changes caused by UC and ME in a pig model. Methods 100 tissue samples (5 × 3 cm) of the abdominal wall were excised in 16 pigs. Excisions were randomly performed manually or by using the self-constructed automatic device at standard power levels (60 W cutting in ME, level 5 in UC) for abdominal surgery. Quality of tissue alteration and depth of coagulation necrosis were examined histopathologically. Device (UC vs. ME) and mode (manually vs. automatic) effects were studied by two-way analysis of variance at a significance level of 5%. Results At the investigated power level settings UC and ME induced qualitatively similar coagulation necroses. Mean depth of necrosis was 450.4 ± 457.8 μm for manual UC and 553.5 ± 326.9 μm for automatic UC versus 149.0 ± 74.3 μm for manual ME and 257.6 ± 119.4 μm for automatic ME. Coagulation necrosis was significantly deeper (p < 0.01) when UC was used compared to ME. The mode of excision (manual versus automatic) did not influence the depth of necrosis (p = 0.85). There was no significant interaction between dissection tool and mode of excision (p = 0.93). Conclusions Thermal injury caused by UC and ME results in qualitatively similar coagulation necrosis. The depth of necrosis is significantly greater in UC compared to ME at investigated standard power levels. PMID:22361346

  17. Terminal values and meaning in life among university students with varied levels of altruism in the present period of socio-cultural change

    Directory of Open Access Journals (Sweden)

    Głaz Stanisław

    2012-01-01

    Full Text Available Abstract The author of this paper, interested in the issues of values preference, meaning in life and altruism among university students has attempted to show a relation between them in the present period of clearly noticeable socio-cultural change. The study was conducted in 2009-2010 in Kraków among university students. The age of the respondents ranged from 21 to 25. 200 sets of correctly completed questionnaires were used for the results analysis.

  18. Evaluation of the uncertainty around the mean level of 137Cs fallout at undisturbed reference site: A simple statistical approach

    International Nuclear Information System (INIS)

    Mabit, L.; Gonsalves, B.C.; Chen, X.; Toloza, A.; Weltin, G.; Darby, I.G.; Padilla-Alvarez, R.

    2015-01-01

    One of the major issues related to the use of 137 Cs as a soil erosion/sedimentation tracer is the selection of the reference site which is used to estimate the initial 137 Cs fallout input (also termed reference inventory). The initial 137 Cs fallout input is a key component of the conversion models used to estimate erosion and sedimentation rates from the 137 Cs data set. The selection and evaluation of the validity of reference sites have been explained in detail in the recent IAEA TECDOC 1741 ‘‘Guidelines for using Fallout radionuclides to assess erosion and effectiveness of soil conservation strategies’’. An investigation was carried out at the experimental research station of the Austrian Agency for Health and Food Safety (AGES), in Austria, Grabenegg (48°07'40 N , 15°13'16 E ). Located at an altitude of 260 m a.s.l, with an annual average temperature of 8.4 °C and annual precipitation of 686 mm, the soil of this area has been classified as Gleyic Cambisol with a silt-loamy texture

  19. Determination of free acid in high level liquid wastes by means of fixed pH value

    International Nuclear Information System (INIS)

    Li Jifu; Duan Shirong; Wu Xi; Yu Xueren

    1991-01-01

    For the determination of free acid in high level liquid wastes, 8% potassium oxalate solution with pH 6.50 as a complex agent of hydrolizable ion is added to 1 AW and the solution is titrated with standard sodium hydroxide to reach the original pH value. The quantity of free acid is calculated by standard sodium hydroxide consumed. This method is simple, rapid and accurate. The relative error of analysis is less than ±4%. The average percentage of recovery is 99.6-101.0%

  20. Resolved nuclear hyperfine structure of muonium in CuCl by means of muon level-crossing resonance

    International Nuclear Information System (INIS)

    Schneider, J.W.; Keller, H.; Odermatt, W.; Puempin, B.; Savic, I.M.; Simmler, H.; Dodds, S.A.; Estle, T.L.; Duvarney, R.C.; Chow, K.; Kadono, R.; Kiefl, R.F.; Li, Q.; Riseman, T.M.; Zhou, H.; Lichti, R.L.; Schwab, C.

    1991-01-01

    Detailed muon level-crossing resonance measurements of Mu I and Mu II centres in single crystals of CuCl are presented. The hyperfine and nuclear hyperfine parameters of the closest two shells of nuclei are remarkably similar for the two centres, indicating that both are located at the same tetrahedral interstitial site with four Cu nearest neighbours and six Cl next-nearest neighbours. About 30% of the total unpaired-electron spin density is located on the muon, about 60% on the four nearest neighbours and the rest on the six next-nearest neighbours, with nothing observable for any other shell. (orig.)

  1. Observation of an isomeric level in 239U by means of the 238U(n,γ)239U reaction

    International Nuclear Information System (INIS)

    Thomas, B.W.; Murray, J.; Rae, E.R.

    1970-01-01

    Low-energy-capture gamma-ray spectra ( 238 U up to a neutron energy of 350 eV. The data were obtained using a 25-cm 3 Ge(Li) detector at the Harwell 45 MeV Electron Linac. Capture events were recorded as functions of gamma-ray energy and neutron time-of-flight, and by suitable analysis of the data time-of-flight spectra have been obtained for individual gamma-rays. The strongest low-energy gamma-ray, at 134 keV, depopulates a level in 239 U at the same energy by an E2-transition to the ground state. The time-of-flight spectrum for this transition indicates that the 134-keV level is isomeric with a half-life of approximately 1 microsecond. This is evident from the long tails on the low-energy side of each resonance, which are not present for other regions of the gamma-ray spectrum. The possibility of using low-energy gamma-rays as a measure of the total capture cross-section is investigated by comparing the time-of-flight spectrum for the 134-keV transition with that for a Moxon-Rae detector under the same experimental conditions. (author)

  2. Nanostructuring of Mo/Si multilayers by means of reactive ion etching using a three-level mask

    International Nuclear Information System (INIS)

    Dreeskornfeld, L.; Haindl, G.; Kleineberg, U.; Heinzmann, U.; Shi, F.; Volland, B.; Rangelow, I.W.; Majkova, E.; Luby, S.; Kostic,; Matay, L.; Hrkut, P.; Hudek, P.; Lee, H.-Y.

    2004-01-01

    Recently, Mo/Si multilayer reflectors have been gaining industry interest as a promising choice for the next generation extreme ultraviolet mask material for printing sub 70 nm feature size devices. A reactive ion etching system with optimized hardware using CHF 3 /Ar process regime shows the capability for highly anisotropic etching of sub congruent with 400 nm feature sizes in Mo/Si test multilayers with ten periods and a bilayer thickness of 7.8 nm which were prepared by e-beam evaporation. A three-level-mask technique consisting of a top resist mask layer poly-methyl-meth-acrylate, a middle hard amorphous Si mask layer and a bottom-level polyimide layer is used to create the etch mask. The etch characteristics of the polyimide film is shown to be one of the major factors determining the success of the described multilayer etching process. The developed etching technology demonstrates superior process performance without facets, excellent uniformity and good profile control. No contamination, degeneration or defect generation in the unetched multilayer structure could be detected. This non-conventional process results in minimum deposition during the etching thus eliminating the need for a dry or wet cleaning. Sidewall angles in Mo/Si multilayers of 85 deg. , without undercut, bowing and ripples resulting in smooth sidewalls are achieved

  3. Revealing molecular-level surface structure of amyloid fibrils in liquid by means of frequency modulation atomic force microscopy

    Energy Technology Data Exchange (ETDEWEB)

    Fukuma, Takeshi [Frontier Science Organization, Kanazawa University, Kakuma-machi, Kanazawa 920-1192 (Japan); Mostaert, Anika S; Jarvis, Suzanne P [Conway Institute of Biomolecular and Biomedical Research, University College Dublin, Belfield, Dublin 4, Republic of Ireland (Ireland); Serpell, Louise C [Department of Biochemistry, University of Sussex, John Maynard Building, Falmer BN1 9QG (United Kingdom)], E-mail: fukuma@staff.kanazawa-u.ac.jp, E-mail: Anika.Mostaert@ucd.ie, E-mail: L.C.Serpell@sussex.ac.uk, E-mail: Suzi.Jarvis@ucd.ie

    2008-09-24

    We have investigated the surface structure of islet amyloid polypeptide (IAPP) fibrils and {alpha}-synuclein protofibrils in liquid by means of frequency modulation atomic force microscopy (FM-AFM). Angstroem-resolution FM-AFM imaging of isolated macromolecules in liquid is demonstrated for the first time. Individual {beta}-strands aligned perpendicular to the fibril axis with a spacing of 0.5 nm are resolved in FM-AFM images, which confirms cross-{beta} structure of IAPP fibrils in real space. FM-AFM images also reveal the existence of 4 nm periodic domains along the axis of IAPP fibrils. Stripe features with 0.5 nm spacing are also found in images of {alpha}-synuclein protofibrils. However, in contrast to the case for IAPP fibrils, the stripes are oriented 30 deg. from the axis, suggesting the possibility of {beta}-strand alignment in protofibrils different from that in mature fibrils or the regular arrangement of thioflavin T molecules present during the fibril preparation aligned at the surface of the protofibrils.

  4. Revealing molecular-level surface structure of amyloid fibrils in liquid by means of frequency modulation atomic force microscopy

    International Nuclear Information System (INIS)

    Fukuma, Takeshi; Mostaert, Anika S; Jarvis, Suzanne P; Serpell, Louise C

    2008-01-01

    We have investigated the surface structure of islet amyloid polypeptide (IAPP) fibrils and α-synuclein protofibrils in liquid by means of frequency modulation atomic force microscopy (FM-AFM). Angstroem-resolution FM-AFM imaging of isolated macromolecules in liquid is demonstrated for the first time. Individual β-strands aligned perpendicular to the fibril axis with a spacing of 0.5 nm are resolved in FM-AFM images, which confirms cross-β structure of IAPP fibrils in real space. FM-AFM images also reveal the existence of 4 nm periodic domains along the axis of IAPP fibrils. Stripe features with 0.5 nm spacing are also found in images of α-synuclein protofibrils. However, in contrast to the case for IAPP fibrils, the stripes are oriented 30 deg. from the axis, suggesting the possibility of β-strand alignment in protofibrils different from that in mature fibrils or the regular arrangement of thioflavin T molecules present during the fibril preparation aligned at the surface of the protofibrils

  5. Fast particles identification in programmable form at level-0 trigger by means of the 3D-Flow system

    International Nuclear Information System (INIS)

    Crosetto, Dario B.

    1998-01-01

    The 3D-Flow Processor system is a new, technology-independent concept in very fast, real-time system architectures. Based on either an FPGA or an ASIC implementation, it can address, in a fully programmable manner, applications where commercially available processors would fail because of throughput requirements. Possible applications include filtering-algorithms (pattern recognition) from the input of multiple sensors, as well as moving any input validated by these filtering-algorithms to a single output channel. Both operations can easily be implemented on a 3D-Flow system to achieve a real-time processing system with a very short lag time. This system can be built either with off-the-shelf FPGAs or, for higher data rates, with CMOS chips containing 4 to 16 processors each. The basic building block of the system, a 3D-Flow processor, has been successfully designed in VHDL code written in ''Generic HDL'' (mostly made of reusable blocks that are synthesizable in different technologies, or FPGAs), to produce a netlist for a four-processor ASIC featuring 0.35 micron CBA (Ceil Base Array) technology at 3.3 Volts, 884 mW power dissipation at 60 MHz and 63.75 mm sq. die size. The same VHDL code has been targeted to three FPGA manufacturers (Altera EPF10K250A, ORCA-Lucent Technologies 0R3T165 and Xilinx XCV1000). A complete set of software tools, the 3D-Flow System Manager, equally applicable to ASIC or FPGA implementations, has been produced to provide full system simulation, application development, real-time monitoring, and run-time fault recovery. Today's technology can accommodate 16 processors per chip in a medium size die, at a cost per processor of less than $5 based on the current silicon die/size technology cost

  6. An analysis on the level changing of UET and SET in blood and urine in early stage of kidney disease caused by diabetes

    International Nuclear Information System (INIS)

    Liu Juzhen; Yang Wenying; Cai Tietie

    2001-01-01

    Objective: To study the relationship between UET and SET variation and early changes of diabetic nephropathy. Methods: UET and SET were measured in 24 patients with diabetes, 19 with early stage diabetic nephropathy, 21 with advanced diabetic nephropathy and 30 normal as contrast. Results: Apparent uprise of UET and SET was observed in all patients when compared to normal contrasts (P 2 -macroglobulin was revealed (P<0.05). Conclusion: UET and SET levels uprose as long as diabetic nephropathy deteriorated. As a result, UET and SET may act as sensitive indices in diagnosing early stage diabetic nephropathy

  7. Robust nuclei segmentation in cyto-histopathological images using statistical level set approach with topology preserving constraint

    Science.gov (United States)

    Taheri, Shaghayegh; Fevens, Thomas; Bui, Tien D.

    2017-02-01

    Computerized assessments for diagnosis or malignancy grading of cyto-histopathological specimens have drawn increased attention in the field of digital pathology. Automatic segmentation of cell nuclei is a fundamental step in such automated systems. Despite considerable research, nuclei segmentation is still a challenging task due noise, nonuniform illumination, and most importantly, in 2D projection images, overlapping and touching nuclei. In most published approaches, nuclei refinement is a post-processing step after segmentation, which usually refers to the task of detaching the aggregated nuclei or merging the over-segmented nuclei. In this work, we present a novel segmentation technique which effectively addresses the problem of individually segmenting touching or overlapping cell nuclei during the segmentation process. The proposed framework is a region-based segmentation method, which consists of three major modules: i) the image is passed through a color deconvolution step to extract the desired stains; ii) then the generalized fast radial symmetry transform is applied to the image followed by non-maxima suppression to specify the initial seed points for nuclei, and their corresponding GFRS ellipses which are interpreted as the initial nuclei borders for segmentation; iii) finally, these nuclei border initial curves are evolved through the use of a statistical level-set approach along with topology preserving criteria for segmentation and separation of nuclei at the same time. The proposed method is evaluated using Hematoxylin and Eosin, and fluorescent stained images, performing qualitative and quantitative analysis, showing that the method outperforms thresholding and watershed segmentation approaches.

  8. A comparative study of reinitialization approaches of the level set method for simulating free-surface flows

    Energy Technology Data Exchange (ETDEWEB)

    Sufyan, Muhammad; Ngo, Long Cu; Choi, Hyoung Gwon [Seoul National University, Seoul (Korea, Republic of)

    2016-04-15

    Unstructured grids were used to compare the performance of a direct reinitialization scheme with those of two reinitialization approaches based on the solution of a hyperbolic Partial differential equation (PDE). The problems of moving interface were solved in the context of a finite element method. A least-square weighted residual method was used to discretize the advection equation of the level set method. The benchmark problems of rotating Zalesak's disk, time-reversed single vortex, and two-dimensional sloshing were examined. Numerical results showed that the direct reinitialization scheme performed better than the PDE-based reinitialization approaches in terms of mass conservation, dissipation and dispersion error, and computational time. In the case of sloshing, numerical results were found to be in good agreement with existing experimental data. The direct reinitialization approach consumed considerably less CPU time than the PDE-based simulations for 20 time periods of sloshing. This approach was stable, accurate, and efficient for all the problems considered in this study.

  9. Developmental screening tools: feasibility of use at primary healthcare level in low- and middle-income settings.

    Science.gov (United States)

    Fischer, Vinicius Jobim; Morris, Jodi; Martines, José

    2014-06-01

    An estimated 150 million children have a disability. Early identification of developmental disabilities is a high priority for the World Health Organization to allow action to reduce impairments through Gap Action Program on mental health. The study identified the feasibility of using the developmental screening and monitoring tools for children aged 0-3 year(s) by non-specialist primary healthcare providers in low-resource settings. A systematic review of the literature was conducted to identify the tools, assess their psychometric properties, and feasibility of use in low- and middle-income countries (LMICs). Key indicators to examine feasibility in LMICs were derived from a consultation with 23 international experts. We identified 426 studies from which 14 tools used in LMICs were extracted for further examination. Three tools reported adequate psychometric properties and met most of the feasibility criteria. Three tools appear promising for use in identifying and monitoring young children with disabilities at primary healthcare level in LMICs. Further research and development are needed to optimize these tools.

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

    Science.gov (United States)

    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. Copyright © 2016 The Authors. Published by Elsevier B.V. All rights reserved.

  11. A quantitative evaluation of pleural effusion on computed tomography scans using B-spline and local clustering level set.

    Science.gov (United States)

    Song, Lei; Gao, Jungang; Wang, Sheng; Hu, Huasi; Guo, Youmin

    2017-01-01

    Estimation of the pleural effusion's volume is an important clinical issue. The existing methods cannot assess it accurately when there is large volume of liquid in the pleural cavity and/or the patient has some other disease (e.g. pneumonia). In order to help solve this issue, the objective of this study is to develop and test a novel algorithm using B-spline and local clustering level set method jointly, namely BLL. The BLL algorithm was applied to a dataset involving 27 pleural effusions detected on chest CT examination of 18 adult patients with the presence of free pleural effusion. Study results showed that average volumes of pleural effusion computed using the BLL algorithm and assessed manually by the physicians were 586 ml±339 ml and 604±352 ml, respectively. For the same patient, the volume of the pleural effusion, segmented semi-automatically, was 101.8% ±4.6% of that was segmented manually. Dice similarity was found to be 0.917±0.031. The study demonstrated feasibility of applying the new BLL algorithm to accurately measure the volume of pleural effusion.

  12. SparCLeS: dynamic l₁ sparse classifiers with level sets for robust beard/moustache detection and segmentation.

    Science.gov (United States)

    Le, T Hoang Ngan; Luu, Khoa; Savvides, Marios

    2013-08-01

    Robust facial hair detection and segmentation is a highly valued soft biometric attribute for carrying out forensic facial analysis. In this paper, we propose a novel and fully automatic system, called SparCLeS, for beard/moustache detection and segmentation in challenging facial images. SparCLeS uses the multiscale self-quotient (MSQ) algorithm to preprocess facial images and deal with illumination variation. Histogram of oriented gradients (HOG) features are extracted from the preprocessed images and a dynamic sparse classifier is built using these features to classify a facial region as either containing skin or facial hair. A level set based approach, which makes use of the advantages of both global and local information, is then used to segment the regions of a face containing facial hair. Experimental results demonstrate the effectiveness of our proposed system in detecting and segmenting facial hair regions in images drawn from three databases, i.e., the NIST Multiple Biometric Grand Challenge (MBGC) still face database, the NIST Color Facial Recognition Technology FERET database, and the Labeled Faces in the Wild (LFW) database.

  13. Loosely coupled level sets for retinal layers and drusen segmentation in subjects with dry age-related macular degeneration

    Science.gov (United States)

    Novosel, Jelena; Wang, Ziyuan; de Jong, Henk; Vermeer, Koenraad A.; van Vliet, Lucas J.

    2016-03-01

    Optical coherence tomography (OCT) is used to produce high-resolution three-dimensional images of the retina, which permit the investigation of retinal irregularities. In dry age-related macular degeneration (AMD), a chronic eye disease that causes central vision loss, disruptions such as drusen and changes in retinal layer thicknesses occur which could be used as biomarkers for disease monitoring and diagnosis. Due to the topology disrupting pathology, existing segmentation methods often fail. Here, we present a solution for the segmentation of retinal layers in dry AMD subjects by extending our previously presented loosely coupled level sets framework which operates on attenuation coefficients. In eyes affected by AMD, Bruch's membrane becomes visible only below the drusen and our segmentation framework is adapted to delineate such a partially discernible interface. Furthermore, the initialization stage, which tentatively segments five interfaces, is modified to accommodate the appearance of drusen. This stage is based on Dijkstra's algorithm and combines prior knowledge on the shape of the interface, gradient and attenuation coefficient in the newly proposed cost function. This prior knowledge is incorporated by varying the weights for horizontal, diagonal and vertical edges. Finally, quantitative evaluation of the accuracy shows a good agreement between manual and automated segmentation.

  14. Using a dynamic, introductory-level volcanoes class as a means to introduce non-science majors to the geosciences

    Science.gov (United States)

    Cook, G. W.

    2012-12-01

    At the University of California, San Diego, I teach a quarter-long, introductory Earth Science class titled "Volcanoes," which is, in essence, a functional class in volcanology designed specifically for non-majors. This large-format (enrollment ~ 85), lecture-based class provides students from an assortment of backgrounds an opportunity to acquire much-needed (and sometimes dreaded) area credits in science, while also serving as an introduction to the Earth Science major at UCSD (offered through Scripps Institution of Oceanography). The overall goal of the course is to provide students with a stimulating and exciting general science option that, using an inherently interesting topic, introduces them to the fundamentals of geoscience. A secondary goal is to promote general science and geoscience literacy among the general population of UCSD. Student evaluations of this course unequivocally indicate a high degree of learning and interest in the material. The majority of students in the class (>80%) are non-science majors and very few students (degree-seeking students. In addition, only a handful of students have typically had any form of geology class beyond high school level Earth Science. Consequently, there are challenges associated with teaching the class. Perhaps most significantly, students have very little background—background that is necessary for understanding the processes involved in volcanic eruptions. Second, many non-science students have built-in anxieties with respect to math and science, anxieties that must be considered when designing curriculum and syllabi. It is essential to provide the right balance of technical information while remaining in touch with the audience. My approach to the class involves a dynamic lecture format that incorporates a wide array of multimedia, analogue demonstrations of volcanic processes, and small-group discussions of topics and concepts. In addition to teaching about volcanoes—a fascinating subject in and of

  15. Mean-level personality development across childhood and adolescence: a temporary defiance of the maturity principle and bidirectional associations with parenting

    NARCIS (Netherlands)

    van den Akker, A.L.; Deković, M.; Asscher, J.; Prinzie, P.

    2014-01-01

    In this study, we investigated mean-level personality development in children from 6 to 20 years of age. Additionally, we investigated longitudinal, bidirectional associations between child personality and maternal overreactive and warm parenting. In this 5-wave study, mothers reported on their

  16. Comparison of established and novel purity tests for the quality control of heparin by means of a set of 177 heparin samples.

    Science.gov (United States)

    Alban, Susanne; Lühn, Susanne; Schiemann, Simone; Beyer, Tanja; Norwig, Jochen; Schilling, Claudia; Rädler, Oliver; Wolf, Bernhard; Matz, Magnus; Baumann, Knut; Holzgrabe, Ulrike

    2011-01-01

    The widespread occurrence of heparin contaminated with oversulfated chrondroitin sulfate (OSCS) in 2008 initiated a comprehensive revision process of the Pharmacopoeial heparin monographs and stimulated research in analytical techniques for the quality control of heparin. Here, a set of 177 heparin samples from the market in 2008 as well as pure heparin sodium spiked with defined amounts of OSCS and DS were used to evaluate established and novel methods for the quality control of heparin. Besides (1)H nuclear magnetic resonance spectroscopy (NMR), the assessment included two further spectroscopic methods, i.e., attenuated total reflection-infrared spectroscopy (ATR-IR) and Raman spectroscopy, three coagulation assays, i.e., activated partial thromboplastin time (aPTT) performed with both sheep and human plasma and the prothrombin time (PT), and finally two novel purity assays, each consisting of an incubation step with heparinase I followed by either a fluorescence measurement (Inc-PolyH-assay) or by a chromogenic aXa-assay (Inc-aXa-assay). NMR was shown to allow not only sensitive detection, but also quantification of OSCS by using the peak-height method and a response factor determined by calibration. Chemometric evaluation of the NMR, ATR-IR, and Raman spectra by statistical classification techniques turned out to be best with NMR spectra concerning the detection of OSCS. The validity of the aPTT, the current EP assay, could be considerably improved by replacing the sheep plasma by human plasma. In this way, most of the contaminated heparin samples did not meet the novel potency limit of 180 IU/mg. However, also more than 50% of the uncontaminated samples had interpretation of the results.

  17. Automatic sets and Delone sets

    International Nuclear Information System (INIS)

    Barbe, A; Haeseler, F von

    2004-01-01

    Automatic sets D part of Z m are characterized by having a finite number of decimations. They are equivalently generated by fixed points of certain substitution systems, or by certain finite automata. As examples, two-dimensional versions of the Thue-Morse, Baum-Sweet, Rudin-Shapiro and paperfolding sequences are presented. We give a necessary and sufficient condition for an automatic set D part of Z m to be a Delone set in R m . The result is then extended to automatic sets that are defined as fixed points of certain substitutions. The morphology of automatic sets is discussed by means of examples

  18. Automatic abdominal multi-organ segmentation using deep convolutional neural network and time-implicit level sets.

    Science.gov (United States)

    Hu, Peijun; Wu, Fa; Peng, Jialin; Bao, Yuanyuan; Chen, Feng; Kong, Dexing

    2017-03-01

    Multi-organ segmentation from CT images is an essential step for computer-aided diagnosis and surgery planning. However, manual delineation of the organs by radiologists is tedious, time-consuming and poorly reproducible. Therefore, we propose a fully automatic method for the segmentation of multiple organs from three-dimensional abdominal CT images. The proposed method employs deep fully convolutional neural networks (CNNs) for organ detection and segmentation, which is further refined by a time-implicit multi-phase evolution method. Firstly, a 3D CNN is trained to automatically localize and delineate the organs of interest with a probability prediction map. The learned probability map provides both subject-specific spatial priors and initialization for subsequent fine segmentation. Then, for the refinement of the multi-organ segmentation, image intensity models, probability priors as well as a disjoint region constraint are incorporated into an unified energy functional. Finally, a novel time-implicit multi-phase level-set algorithm is utilized to efficiently optimize the proposed energy functional model. Our method has been evaluated on 140 abdominal CT scans for the segmentation of four organs (liver, spleen and both kidneys). With respect to the ground truth, average Dice overlap ratios for the liver, spleen and both kidneys are 96.0, 94.2 and 95.4%, respectively, and average symmetric surface distance is less than 1.3 mm for all the segmented organs. The computation time for a CT volume is 125 s in average. The achieved accuracy compares well to state-of-the-art methods with much higher efficiency. A fully automatic method for multi-organ segmentation from abdominal CT images was developed and evaluated. The results demonstrated its potential in clinical usage with high effectiveness, robustness and efficiency.

  19. PROBLEM SETTING AND SOLUTION OF THE RESPONSE CORRECTION OF ARRIVAL AND DEPARTURE AIR TRAFFIC FLOW IN THE VICINITY OF THE FIELD BY MEANS OF THE GENETIC ALGORITHM

    Directory of Open Access Journals (Sweden)

    Georgii N. Lebedev

    2017-01-01

    Full Text Available The improvement in the effectiveness of airfield operation largely depends on the problem solving quality on the interaction boundaries of different technological sections. One of such hotspots is the use of the same runway by inbound and outbound aircraft. At certain intensity of outbound and inbound air traffic flow the conflict of aircraft interests appears, where it may be quite difficult to sort out priorities even for experienced controllers, in consequence of which mistakes in decision-making unavoidably appear.In this work the task of response correction of landing and takeoff time of the aircraft using the same RW, in condition of the conflict of interests “arrival – departure” at the increased operating intensity is formulated. The choice of optimal solution is made taking into account mutual interests without the complete sorting and the evaluation of all solutions.Accordingly, the genetic algorithm, which offers a simple and effective approach to optimal control problem solution by providing flight safety at an acceptably high level, is proposed. The estimation of additional aviation fuel consumption is used as optimal choice evaluation criterion.The advantages of the genetic algorithm application at decision-making in comparison with today’s “team” solution of the conflict “departure – arrival” in the airfield area are shown.

  20. The Consortium for Evidence Based Research in Rural Educational Settings (CEBRRES): Applying Collaborative Action Research as a Means of Enhancing the Development of Rural Middle School Science Teachers

    Science.gov (United States)

    Wulff, A. H.

    2006-05-01

    Kentucky ranks third in the U.S. in need of rural education attention. Rural schools in Kentucky serve nearly 40% of the total student population, and graduation rates and NAEP scores are low. A two-year pilot study is being completed addressing psychological, social, and content knowledge based constructs, as they apply to science and mathematics achievement in rural environments. The goals are to identify the key aspects of rural teachers knowledge and skills, use a framework to describe how knowledge and skills develop in the rural classroom, apply a useful model of intervention to promote teacher development and increased student learning. If proven successful the knowledge can be incorporated into the practice of current teaching and preservice pedagogical methods. The problem that was identified and addressed by CEBRRES is the high level of student disengagement and the shortage of rigorous stimulating curriculum models. The action taken was the development and implementation of model eliciting activities. Teachers at the target school were expected to utilize action research methodology to execute model-eliciting activities in the classroom, and then communicate results in forms that are useful for other teachers. Benefits to teachers included stipends, increased science content depth and breadth, support to achieve "highly qualified teacher status", extensive professional development, and technology, equipment, and supplies for their school. Survey instruments were devised to address school perceptions (61% worry that they are not doing well enough in school), future plans (80% expect to attend college vs. the current 47.5%), various self concepts, academic self concepts (23% feel that learning is difficult for them), and family self concepts. Science was identified by the students as the subject that interests them the most, followed by math, yet Kentucky ranks near the bottom of the U.S. in math and science training in the workplace. Geology

  1. County-Level Human Well-Being Index and Domain Scores (2000-2010) plus EQI data set (2000-2005)

    Data.gov (United States)

    U.S. Environmental Protection Agency — The HWBI_Draft_1 is an internal map service being prepared for public release (early FY18). This map services contains mean county-level HWBI, domain, indicators and...

  2. Clinical course and outcome of patients with high-level microsatellite instability cancers in a real-life setting: a retrospective analysis

    Directory of Open Access Journals (Sweden)

    Halpern N

    2017-03-01

    Full Text Available Naama Halpern,1 Yael Goldberg,2 Luna Kadouri,2 Morasha Duvdevani,2 Tamar Hamburger,2 Tamar Peretz,2 Ayala Hubert2 1Institute of Oncology, The Chaim Sheba Medical Center, Tel Hashomer, Israel; 2Sharett Institute of Oncology, Hadassah Medical Center, Hebrew University, Jerusalem, Israel Background: The prognostic and predictive significance of the high-level microsatellite instability (MSI-H phenotype in various malignancies is unclear. We describe the characteristics, clinical course, and outcomes of patients with MSI-H malignancies treated in a real-life hospital setting.Patients and methods: A retrospective analysis of MSI-H cancer patient files was conducted. We analyzed the genetic data, clinical characteristics, and oncological treatments, including chemotherapy and surgical interventions.Results: Clinical data of 73 MSI-H cancer patients were available. Mean age at diagnosis of first malignancy was 52.3 years. Eight patients (11% had more than four malignancies each. Most patients (76% had colorectal cancer (CRC. Seventeen patients (23% had only extracolonic malignancies. Eighteen women (36% had gynecological malignancy. Nine women (18% had breast cancer. Mean follow-up was 8.5 years. Five-year overall survival and disease-free survival of all MSI-H cancer patients from first malignancy were 86% and 74.6%, respectively. Five-year overall survival rates of stage 2, 3, and 4 MSI-H CRC patients were 89.5%, 58.4%, and 22.9%, respectively.Conclusion: Although the overall prognosis of MSI-H cancer patients is favorable, this advantage may not be maintained in advanced MSI-H CRC patients. Keywords: microsatellite instability, malignancy, treatment, outcome

  3. Analysis of carotid artery plaque and wall boundaries on CT images by using a semi-automatic method based on level set model

    International Nuclear Information System (INIS)

    Saba, Luca; Sannia, Stefano; Ledda, Giuseppe; Gao, Hao; Acharya, U.R.; Suri, Jasjit S.

    2012-01-01

    The purpose of this study was to evaluate the potentialities of a semi-automated technique in the detection and measurement of the carotid artery plaque. Twenty-two consecutive patients (18 males, 4 females; mean age 62 years) examined with MDCTA from January 2011 to March 2011 were included in this retrospective study. Carotid arteries are examined with a 16-multi-detector-row CT system, and for each patient, the most diseased carotid was selected. In the first phase, the carotid plaque was identified and one experienced radiologist manually traced the inner and outer boundaries by using polyline and radial distance method (PDM and RDM, respectively). In the second phase, the carotid inner and outer boundaries were traced with an automated algorithm: level-set-method (LSM). Data were compared by using Pearson rho correlation, Bland-Altman, and regression. A total of 715 slices were analyzed. The mean thickness of the plaque using the reference PDM was 1.86 mm whereas using the LSM-PDM was 1.96 mm; using the reference RDM was 2.06 mm whereas using the LSM-RDM was 2.03 mm. The correlation values between the references, the LSM, the PDM and the RDM were 0.8428, 0.9921, 0.745 and 0.6425. Bland-Altman demonstrated a very good agreement in particular with the RDM method. Results of our study indicate that LSM method can automatically measure the thickness of the plaque and that the best results are obtained with the RDM. Our results suggest that advanced computer-based algorithms can identify and trace the plaque boundaries like an experienced human reader. (orig.)

  4. Analysis of carotid artery plaque and wall boundaries on CT images by using a semi-automatic method based on level set model

    Energy Technology Data Exchange (ETDEWEB)

    Saba, Luca; Sannia, Stefano; Ledda, Giuseppe [University of Cagliari - Azienda Ospedaliero Universitaria di Cagliari, Department of Radiology, Monserrato, Cagliari (Italy); Gao, Hao [University of Strathclyde, Signal Processing Centre for Excellence in Signal and Image Processing, Department of Electronic and Electrical Engineering, Glasgow (United Kingdom); Acharya, U.R. [Ngee Ann Polytechnic University, Department of Electronics and Computer Engineering, Clementi (Singapore); Suri, Jasjit S. [Biomedical Technologies Inc., Denver, CO (United States); Idaho State University (Aff.), Pocatello, ID (United States)

    2012-11-15

    The purpose of this study was to evaluate the potentialities of a semi-automated technique in the detection and measurement of the carotid artery plaque. Twenty-two consecutive patients (18 males, 4 females; mean age 62 years) examined with MDCTA from January 2011 to March 2011 were included in this retrospective study. Carotid arteries are examined with a 16-multi-detector-row CT system, and for each patient, the most diseased carotid was selected. In the first phase, the carotid plaque was identified and one experienced radiologist manually traced the inner and outer boundaries by using polyline and radial distance method (PDM and RDM, respectively). In the second phase, the carotid inner and outer boundaries were traced with an automated algorithm: level-set-method (LSM). Data were compared by using Pearson rho correlation, Bland-Altman, and regression. A total of 715 slices were analyzed. The mean thickness of the plaque using the reference PDM was 1.86 mm whereas using the LSM-PDM was 1.96 mm; using the reference RDM was 2.06 mm whereas using the LSM-RDM was 2.03 mm. The correlation values between the references, the LSM, the PDM and the RDM were 0.8428, 0.9921, 0.745 and 0.6425. Bland-Altman demonstrated a very good agreement in particular with the RDM method. Results of our study indicate that LSM method can automatically measure the thickness of the plaque and that the best results are obtained with the RDM. Our results suggest that advanced computer-based algorithms can identify and trace the plaque boundaries like an experienced human reader. (orig.)

  5. Not Worth the Extra Cost? Diluting the Differentiation Ability of Highly Rated Products by Altering the Meaning of Rating Scale Levels

    DEFF Research Database (Denmark)

    Meissner, Martin; Heinzle, Stefanie Lena; Decker, Reinhold

    2013-01-01

    Over the last decade, the use of rating scales has grown in popularity in various fields, including customer online reviews and energy labels. Rating scales convey important information on attributes of products or services that consumers evaluate in their purchase decisions. By applying...... characteristics. In addition, two choice-based conjoint studies examine whether the way consumers make their choices among products can be influenced by changing the labeling of rating scale levels. The results show that a manipulation of the meaning of rating scale levels diminishes both the importance...

  6. The Analysis of Nonstationary Time Series Using Regression, Correlation and Cointegration with an Application to Annual Mean Temperature and Sea Level

    DEFF Research Database (Denmark)

    Johansen, Søren

    There are simple well-known conditions for the validity of regression and correlation as statistical tools. We analyse by examples the effect of nonstationarity on inference using these methods and compare them to model based inference. Finally we analyse some data on annual mean temperature...... and sea level, by applying the cointegrated vector autoregressive model, which explicitly takes into account the nonstationarity of the variables....

  7. The analysis of nonstationary time series using regression, correlation and cointegration – with an application to annual mean temperature and sea level

    DEFF Research Database (Denmark)

    Johansen, Søren

    There are simple well-known conditions for the validity of regression and correlation as statistical tools. We analyse by examples the effect of nonstationarity on inference using these methods and compare them to model based inference. Finally we analyse some data on annual mean temperature...... and sea level, by applying the cointegrated vector autoregressive model, which explicitly takes into account the nonstationarity of the variables....

  8. The effect of goal setting on fruit and vegetable consumption and physical activity level in a Web-based intervention.

    Science.gov (United States)

    O'Donnell, Stephanie; Greene, Geoffrey W; Blissmer, Bryan

    2014-01-01

    To explore the relationship between goal setting and fruit and vegetable (FV) consumption and physical activity (PA) in an intervention for college students. Secondary data analysis of intervention group participants from a 10-week online intervention with complete weekly data (n = 724). Outcomes (cups of FV per day and minutes of PA per week) and goals for both behaviors were reported online each week. Weekly differences between goals and behaviors were calculated, as well as the proportion meeting individual goals and meeting recommendations for behaviors. There were significant (P goal setting on both behaviors and of goal group (tertile of meeting weekly goals) on behavior, as well as meeting recommendations for both behaviors. There was an increase in FV consumption (P Goal setting as part of a Web-based intervention for college students was effective, but results differed for FV and PA. Goal setting for maintaining behavior may need to differ from goal setting for changing behavior. Copyright © 2014 Society for Nutrition Education and Behavior. Published by Elsevier Inc. All rights reserved.

  9. Higher glucose level and systemic oxidative stress decrease the mean velocity index of the retinal artery during flickering light stimulation in type 1 diabetes.

    Science.gov (United States)

    Debelić, Vladimir; Drnovšek Olup, Brigita; Žižek, Bogomir; Skitek, Milan; Jerin, Aleš

    2016-10-31

    To determine whether higher glucose level and systemic oxidative stress decrease mean velocity (MV) index of the central retinal artery (CRA) during flickering light stimulation in type 1 diabetes (T1D). The study was performed in the period from 2008 to 2015 at the University Eye Clinic in Ljubljana. 41 patients with T1D and 37 participants without diabetes were included. MV in the CRA was measured using Doppler ultrasound diagnostics in basal conditions and during 8 Hz flickering light irritation. The plasma levels of glucose, fructosamine, 8-hydroxy-2'-deoxyguanosine (8-OHdG), triglycerides, cholesterol, and low-density lipoprotein (LDL) were measured. Patients with T1D had significantly higher levels of blood glucose (Ptriglycerides (P=0.108), cholesterol (P=0.531), and LDL (P=0.645) between the groups. Patients with T1D also had a significantly lower MV index in the CRA (1.11±0.15 vs 1.24±0.23; P=0.010). In the T1D group, a significant negative correlation was found between the level of glucose (r=0.58; Pindex in the CRA. At the same time, in this group fructosamine and 8-OHdG levels had a separate effect on the MV index (adjusted R2=0.38, Pglucose levels, the medium-term glucose level, and systemic oxidative stress could importantly reduce retinal vasodilatation during flickering light irritation in patients with T1D.

  10. Methodology for setting the reference levels in the measurements of the dose rate absorbed in air due to the environmental gamma radiation

    International Nuclear Information System (INIS)

    Dominguez Ley, Orlando; Capote Ferrera, Eduardo; Caveda Ramos, Celia; Alonso Abad, Dolores

    2008-01-01

    Full text: The methodology for setting the reference levels of the measurements of the gamma dose rate absorbed in the air is described. The registration level was obtained using statistical methods. To set the alarm levels, it was necessary to begin with certain affectation level, which activates the investigation operation mode when being reached. It is was necessary to transform this affectation level into values of the indicators selected to set the appearance of an alarm in the network, allowing its direct comparison and at the same time a bigger operability of this one. The affectation level was assumed as an effective dose of 1 mSv/y, which is the international dose limit for public. The conversion factor obtained in a practical way as a consequence of the Chernobyl accident was assumed, converting the value of annual effective dose into values of effective dose rate in air. These factors are the most important in our work, since the main task of the National Network of Environmental Radiological Surveillance of the Republic of Cuba is detecting accidents with a situations regional affectation, and this accident is precisely an example of pollution at this scale. The alarm level setting was based on the results obtained in the first year of the Chernobyl accident. For this purpose, some transformations were achieved. In the final results, a correction factor was introduced depending on the year season the measurement was made. It was taken into account the influence of different meteorological events on the measurement of this indicator. (author)

  11. Influence of the level of fit of a density probability function to wind-speed data on the WECS mean power output estimation

    International Nuclear Information System (INIS)

    Carta, Jose A.; Ramirez, Penelope; Velazquez, Sergio

    2008-01-01

    Static methods which are based on statistical techniques to estimate the mean power output of a WECS (wind energy conversion system) have been widely employed in the scientific literature related to wind energy. In the static method which we use in this paper, for a given wind regime probability distribution function and a known WECS power curve, the mean power output of a WECS is obtained by resolving the integral, usually using numerical evaluation techniques, of the product of these two functions. In this paper an analysis is made of the influence of the level of fit between an empirical probability density function of a sample of wind speeds and the probability density function of the adjusted theoretical model on the relative error ε made in the estimation of the mean annual power output of a WECS. The mean power output calculated through the use of a quasi-dynamic or chronological method, that is to say using time-series of wind speed data and the power versus wind speed characteristic of the wind turbine, serves as the reference. The suitability of the distributions is judged from the adjusted R 2 statistic (R a 2 ). Hourly mean wind speeds recorded at 16 weather stations located in the Canarian Archipelago, an extensive catalogue of wind-speed probability models and two wind turbines of 330 and 800 kW rated power are used in this paper. Among the general conclusions obtained, the following can be pointed out: (a) that the R a 2 statistic might be useful as an initial gross indicator of the relative error made in the mean annual power output estimation of a WECS when a probabilistic method is employed; (b) the relative errors tend to decrease, in accordance with a trend line defined by a second-order polynomial, as R a 2 increases

  12. Influence of the level of fit of a density probability function to wind-speed data on the WECS mean power output estimation

    Energy Technology Data Exchange (ETDEWEB)

    Carta, Jose A. [Department of Mechanical Engineering, University of Las Palmas de Gran Canaria, Campus de Tafira s/n, 35017 Las Palmas de Gran Canaria, Canary Islands (Spain); Ramirez, Penelope; Velazquez, Sergio [Department of Renewable Energies, Technological Institute of the Canary Islands, Pozo Izquierdo Beach s/n, 35119 Santa Lucia, Gran Canaria, Canary Islands (Spain)

    2008-10-15

    Static methods which are based on statistical techniques to estimate the mean power output of a WECS (wind energy conversion system) have been widely employed in the scientific literature related to wind energy. In the static method which we use in this paper, for a given wind regime probability distribution function and a known WECS power curve, the mean power output of a WECS is obtained by resolving the integral, usually using numerical evaluation techniques, of the product of these two functions. In this paper an analysis is made of the influence of the level of fit between an empirical probability density function of a sample of wind speeds and the probability density function of the adjusted theoretical model on the relative error {epsilon} made in the estimation of the mean annual power output of a WECS. The mean power output calculated through the use of a quasi-dynamic or chronological method, that is to say using time-series of wind speed data and the power versus wind speed characteristic of the wind turbine, serves as the reference. The suitability of the distributions is judged from the adjusted R{sup 2} statistic (R{sub a}{sup 2}). Hourly mean wind speeds recorded at 16 weather stations located in the Canarian Archipelago, an extensive catalogue of wind-speed probability models and two wind turbines of 330 and 800 kW rated power are used in this paper. Among the general conclusions obtained, the following can be pointed out: (a) that the R{sub a}{sup 2} statistic might be useful as an initial gross indicator of the relative error made in the mean annual power output estimation of a WECS when a probabilistic method is employed; (b) the relative errors tend to decrease, in accordance with a trend line defined by a second-order polynomial, as R{sub a}{sup 2} increases. (author)

  13. Continuous soil maps - a fuzzy set approach to bridge the gap between aggregation levels of process and distribution models

    NARCIS (Netherlands)

    Gruijter, de J.J.; Walvoort, D.J.J.; Gaans, van P.F.M.

    1997-01-01

    Soil maps as multi-purpose models of spatial soil distribution have a much higher level of aggregation (map units) than the models of soil processes and land-use effects that need input from soil maps. This mismatch between aggregation levels is particularly detrimental in the context of precision

  14. The Level of Vision Necessary for Competitive Performance in Rifle Shooting: Setting the Standards for Paralympic Shooting with Vision Impairment

    NARCIS (Netherlands)

    Allen, P.M.; Latham, K.; Mann, D.L.; Ravensbergen, H.J.C.; Myint, J.

    2016-01-01

    The aim of this study was to investigate the level of vision impairment (VI) that would reduce performance in shooting; to guide development of entry criteria to visually impaired (VI) shooting. Nineteen international-level shooters without VI took part in the study. Participants shot an air rifle,

  15. Dose limits, constraints, reference levels. What does it mean for radiation protection?; Grenzwerte, Richtwerte, Referenzwerte. Was bedeutet das fuer den Strahlenschutz

    Energy Technology Data Exchange (ETDEWEB)

    Breckow, J. [Technische Hochschule Mittelhessen (THM), Giessen (Germany). Inst. fuer Medizinische Physik und Strahlenschutz (IMPS)

    2016-07-01

    The established concept of radiation protection with its basic principles justification, optimization, and limitation has proved its value and is going to be continued. In its deeper meaning, however, the concept is rather subtle and complex. Furthermore, in some aspects there remain some breaches or inconsistencies. This is just true for the terms dose limit, reference lever, and constraint that are tightly associated with the radiation protection principles. In order to guarantee the ability of radiation protection in whole extent, the subtle differences of meaning have to be communicated. There is a permanent need to defend the conceptual function of these terms against deliberate or undeliberate misinterpretations. Reference levels are definitely not the same as dose limits and they may not be misused as such. Any attempt to misinterpret fundamental radiation protection principles for selfish purposes should discouraged vigorously.

  16. Economic comparison of food, non food crops, set-aside at a regional level with a linear programming model

    International Nuclear Information System (INIS)

    Sourie, J.C.; Hautcolas, J.C.; Blanchet, J.

    1992-01-01

    This paper is concerned with a regional linear programming model. Its purpose is a simulation of the European Economic Community supply of non-food crops at the farm gate according to different sets of European Common Agriculture Policy (CAP) measures. The methodology is first described with a special emphasis on the aggregation problem. The model allows the simultaneous calculation of the impact of non food crops on the farmer's income and on the agricultural budget. The model is then applied to an intensive agricultural region (400 000 ha of arable land). In this region, sugar beet and rape seem the less costly resources, both for the farmers and the CAP taxpayers. An improvement of the economic situation of the two previous agents can be obtained only if a tax exemption on ethanol and rape oil and a subsidy per hactare are allowed. This subsidy can be lower than the set aside premium. (author)

  17. Developmental Screening Tools: Feasibility of Use at Primary Healthcare Level in Low- and Middle-income Settings

    OpenAIRE

    Fischer, Vinicius Jobim; Morris, Jodi; Martines, José

    2014-01-01

    ABSTRACT An estimated 150 million children have a disability. Early identification of developmental disabilities is a high priority for the World Health Organization to allow action to reduce impairments through Gap Action Program on mental health. The study identified the feasibility of using the developmental screening and monitoring tools for children aged 0-3 year(s) by non-specialist primary healthcare providers in low-resource settings. A systematic review of the literature was conducte...

  18. The RISC-V Instruction Set Manual. Volume 1: User-Level ISA, Version 2.0

    Science.gov (United States)

    2014-05-06

    RV128I Base Integer Instruction Set 81 18 Calling Convention 83 18.1 C Datatypes and Alignment...FCVT.D.S, are encoded in the OP-FP major opcode space and both the source and destination are floating-point registers. The rs2 field encodes the datatype ...of the source, and the fmt field encodes the datatype of the destination. FCVT.S.D rounds according to the RM field; FCVT.D.S will never round. 31 27

  19. Mean Platelet Volume, Vitamin D and C Reactive Protein Levels in Normal Weight Children with Primary Snoring and Obstructive Sleep Apnea Syndrome.

    Science.gov (United States)

    Zicari, Anna Maria; Occasi, Francesca; Di Mauro, Federica; Lollobrigida, Valeria; Di Fraia, Marco; Savastano, Vincenzo; Loffredo, Lorenzo; Nicita, Francesco; Spalice, Alberto; Duse, Marzia

    2016-01-01

    Studies on Mean Platelet Volume (MPV) in children with Sleep Disordered Breathing (SDB) report conflicting results and the hypothesis of an intermittent hypoxemia leading to a systemic inflammation is reaching consensus. Vitamin D exerts anti-inflammatory properties and its deficiency has been supposed to play a role in sleep disorders. Emerging interest is rising about Primary Snoring (PS) since it is reasonable that also undetectable alteration of hypoxia might predispose to an increased production of inflammatory mediators. In this perspective, in a group of children affected by SDB, our aim was to investigate MPV, vitamin D and C Reactive Protein (CRP) levels, which had been previously evaluated separately in different studies focused only on Obstructive Sleep Apnea Syndrome (OSAS). We enrolled 137 children: 70 healthy controls (HC), 67 affected by SDB undergoing a polysomnographic evaluation, 22 with a diagnosis of PS and 45 with a diagnosis of OSAS. All patients underwent routine biochemical evaluations including blood cell counts, CRP and vitamin D. Children affected by SDB had a mean age of 8.49±2.19 and were prevalently males (23 females, 34%; 44 males, 66%). MPV levels were higher in OSAS and PS when compared to HC; platelet count (PLT) and CRP levels were higher while Vitamin D levels were lower in children with SDB when compared to HC. MPV levels were correlated with PLT (r = -0.54; pchildren with PS as well as in children with OSAS, and supports the underlying inflammation, hence, highlighting the importance of an early diagnosis of this previously considered benign form of SDB.

  20. FGOALS-s2 simulation of upper-level jet streams over East Asia: Mean state bias and synoptic-scale transient eddy activity

    Science.gov (United States)

    Song, Fengfei; Zhou, Tianjun

    2013-05-01

    Upper-level jet streams over East Asia simulated by the LASG/IAP coupled climate system model FGOALS-s2 were assessed, and the mean state bias explained in terms of synoptic-scale transient eddy activity (STEA). The results showed that the spatial distribution of the seasonal mean jet stream was reproduced well by the model, except that following a weaker meridional temperature gradient (MTG), the intensity of the jet stream was weaker than in National Centers for Environment Prediction (NCEP)/Department of Energy Atmospheric Model Inter-comparison Project II reanalysis data (NCEP2). Based on daily mean data, the jet core number was counted to identify the geographical border between the East Asian Subtropical Jet (EASJ) and the East Asian Polar-front Jet (EAPJ). The border is located over the Tibetan Plateau according to NCEP2 data, but was not evident in FGOALS-s2 simulations. The seasonal cycles of the jet streams were found to be reasonably reproduced, except that they shifted northward relative to reanalysis data in boreal summer owing to the northward shift of negative MTGs. To identify the reasons for mean state bias, the dynamical and thermal forcings of STEA on mean flow were examined with a focus on boreal winter. The dynamical and thermal forcings were estimated by extended Eliassen-Palm flux ( E) and transient heat flux, respectively. The results showed that the failure to reproduce the tripolar-pattern of the divergence of E over the jet regions led to an unsuccessful separation of the EASJ and EAPJ, while dynamical forcing contributed less to the weaker EASJ. In contrast, the weaker transient heat flux partly explained the weaker EASJ over the ocean.

  1. Evaluation of gravity field model EIGEN-6C4 by means of various functions of gravity potential, and by GNSS/levelling

    Directory of Open Access Journals (Sweden)

    Jan Kostelecký

    2015-06-01

    Full Text Available The combined gravity field model EIGEN-6C4 (Förste et al., 2014 is the latest combined global gravity field model of GFZ Potsdam and GRGS Toulouse. EIGEN-6C4 has been generated including the satellite gravity gradiometry data of the entire GOCE mission (November 2009 till October 2013 and is of maximum spherical degree and order 2190. In this study EIGEN-6C4 has been compared with EGM2008 to its maximum degree and order via gravity disturbances and Tzz part of the Marussi tensor of the second derivatives of the disturbing potential. The emphasis is put on such areas where GOCE data (complete set of gradiometry measurements after reductions in EIGEN-6C4 obviously contributes to an improvement of the gravity field description. GNSS/levelling geoid heights are independent data source for the evaluation of gravity field models. Therefore, we use the GNSS/levelling data sets over the territories of Europe, Czech Republic and Slovakia for the evaluation of EIGEN-6C4 w.r.t. EGM2008.

  2. Mean Platelet Volume, Vitamin D and C Reactive Protein Levels in Normal Weight Children with Primary Snoring and Obstructive Sleep Apnea Syndrome.

    Directory of Open Access Journals (Sweden)

    Anna Maria Zicari

    Full Text Available Studies on Mean Platelet Volume (MPV in children with Sleep Disordered Breathing (SDB report conflicting results and the hypothesis of an intermittent hypoxemia leading to a systemic inflammation is reaching consensus. Vitamin D exerts anti-inflammatory properties and its deficiency has been supposed to play a role in sleep disorders. Emerging interest is rising about Primary Snoring (PS since it is reasonable that also undetectable alteration of hypoxia might predispose to an increased production of inflammatory mediators. In this perspective, in a group of children affected by SDB, our aim was to investigate MPV, vitamin D and C Reactive Protein (CRP levels, which had been previously evaluated separately in different studies focused only on Obstructive Sleep Apnea Syndrome (OSAS.We enrolled 137 children: 70 healthy controls (HC, 67 affected by SDB undergoing a polysomnographic evaluation, 22 with a diagnosis of PS and 45 with a diagnosis of OSAS. All patients underwent routine biochemical evaluations including blood cell counts, CRP and vitamin D.Children affected by SDB had a mean age of 8.49±2.19 and were prevalently males (23 females, 34%; 44 males, 66%. MPV levels were higher in OSAS and PS when compared to HC; platelet count (PLT and CRP levels were higher while Vitamin D levels were lower in children with SDB when compared to HC. MPV levels were correlated with PLT (r = -0.54; p<0.001, vitamin D (r = -0.39; p<0.001 and CRP (r = 0.21; p<0.01. A multiple regression was run to predict MPV levels from vitamin D, CRP and PLT and these variables significantly predicted MPV (F = 17.42, p<0.0001; adjusted R2 = 0.37. Only platelet count and vitamin D added statistically significantly to the prediction (p<0.05.The present study provides evidence of higher MPV and lower vitamin D levels in children with PS as well as in children with OSAS, and supports the underlying inflammation, hence, highlighting the importance of an early diagnosis of this

  3. Internal variability in a 1000-yr control simulation with the coupled climate model ECHO-G - I. Near-surface temperature, precipitation and mean sea level pressure.

    Energy Technology Data Exchange (ETDEWEB)

    Min, Seung-Ki; Hense, Andreas [Univ. of Bonn (Germany). Meteorological Inst.; Legutke, Stephanie [Max Planck Inst. for Meteorology, Hamburg (Germany); Kwon, Won-Tae [Meteorological Research Inst., Seoul (Korea, Republic of)

    2005-08-01

    The internal variability in a 1000-yr control simulation with the coupled atmosphere/ocean global climate model ECHO-G is analysed using near-surface temperature, precipitation and mean sea level pressure variables, and is compared with observations and other coupled climate model simulations. ECHO-G requires annual mean flux adjustments for heat and freshwater in order to simulate no significant climate drift for 1000 yr, but no flux adjustments for momentum. The ECHO-G control run captures well most aspects of the observed seasonal and annual climatology and of the interannual to decadal variability of the three variables. Model biases are very close to those in ECHAM4 (atmospheric component of ECHO-G) stand-alone integrations with prescribed observed sea surface temperature. A trend comparison between observed and modelled near-surface temperatures shows that the observed near-surface global warming is larger than internal variability produced by ECHO-G, supporting previous studies. The simulated global mean near-surface temperatures, however, show a 2-yr spectral peak which is linked with a strong biennial bias of energy in the El Nino Southern Oscillation signal. Consequently, the interannual variability (39 yr) is underestimated.

  4. A comparison of mean glandular dose diagnostic reference levels within the all-digital irish national breast screening programme and the Irish symptomatic breast services

    International Nuclear Information System (INIS)

    O'Leary, D.; Rainford, L.

    2013-01-01

    Data on image quality, compression and radiation dose were collected from symptomatic breast units within the Republic of Ireland. Quantitative and qualitative data were analysed using SPSS. Recommendations of mean glandular dose (MGD) diagnostic reference levels were made at various levels for film-screen and full field digital mammography units to match levels published worldwide. MGDs received by symptomatic breast patients within Ireland are higher than those received in the all-digital Irish Breast Screening service; 55-65 mm breast: 1.75 mGy (screening) vs. 2.4 mGy (symptomatic) at the 95. percentile; various reasons are proposed for the differences. MGDs achieved in the screening service may be lower because of the exacting requirements for radiographer training, characteristics of the patients and equipment quality assurance levels. More precise imaging guidelines, standards and training of symptomatic radiographers performing mammography are suggested to remediate MGDs delivered to the breasts of Irish women attending the symptomatic breast services. (authors)

  5. "Notice the Similarities between the Two Sets …": Imperative Usage in a Corpus of Upper-Level Student Papers

    Science.gov (United States)

    Neiderhiser, Justine A.; Kelley, Patrick; Kennedy, Kohlee M.; Swales, John M.; Vergaro, Carla

    2016-01-01

    The sparse literature on the use of imperatives in research papers suggests that they are relatively common in a small number of disciplines, but rare, if used at all, in others. The present study addresses the use of imperatives in a corpus of upper-level A-graded student papers from 16 disciplines. A total of 822 papers collected within the past…

  6. Tails from previous exposures: a general problem in setting reference levels for the assessment of internal contamination

    International Nuclear Information System (INIS)

    Breuer, F.; Frittelli, L.

    1988-01-01

    Reference levels for retention and excretion are evaluated for routine and special monitoring following the intake of a fraction of ICRP annual limits (ALIs) or of a unit activity. Methodologies are also suggested for taking into account the contribution by previous intakes to excretion or retention

  7. The Level of Vision Necessary for Competitive Performance in Rifle Shooting: Setting the Standards for Paralympic Shooting with Vision Impairment.

    Science.gov (United States)

    Allen, Peter M; Latham, Keziah; Mann, David L; Ravensbergen, Rianne H J C; Myint, Joy

    2016-01-01

    The aim of this study was to investigate the level of vision impairment (VI) that would reduce performance in shooting; to guide development of entry criteria to visually impaired (VI) shooting. Nineteen international-level shooters without VI took part in the study. Participants shot an air rifle, while standing, toward a regulation target placed at the end of a 10 m shooting range. Cambridge simulation glasses were used to simulate six different levels of VI. Visual acuity (VA) and contrast sensitivity (CS) were assessed along with shooting performance in each of seven conditions of simulated impairment and compared to that with habitual vision. Shooting performance was evaluated by calculating each individual's average score in every level of simulated VI and normalizing this score by expressing it as a percentage of the baseline performance achieved with habitual vision. Receiver Operating Characteristic curves were constructed to evaluate the ability of different VA and CS cut-off criteria to appropriately classify these athletes as achieving 'expected' or 'below expected' shooting results based on their performance with different levels of VA and CS. Shooting performance remained relatively unaffected by mild decreases in VA and CS, but quickly deteriorated with more moderate losses. The ability of visual function measurements to classify shooting performance was good, with 78% of performances appropriately classified using a cut-off of 0.53 logMAR and 74% appropriately classified using a cut-off of 0.83 logCS. The current inclusion criteria for VI shooting (1.0 logMAR) is conservative, maximizing the chance of including only those with an impairment that does impact performance, but potentially excluding some who do have a genuine impairment in the sport. A lower level of impairment would include more athletes who do have a genuine impairment but would potentially include those who do not actually have an impairment that impacts performance in the sport. An

  8. The Level of Vision Necessary for Competitive Performance in Rifle Shooting: Setting the Standards for Paralympic Shooting With Vision Impairment

    Directory of Open Access Journals (Sweden)

    Peter M Allen

    2016-11-01

    Full Text Available The aim of this study was to investigate the level of vision impairment that would reduce performance in shooting; to guide development of entry criteria to visually impaired (VI shooting. Nineteen international-level shooters without vision impairment took part in the study. Participants shot an air rifle, while standing, towards a regulation target placed at the end of a 10m shooting range. Cambridge simulation glasses were used to simulate six different levels of vision impairment. Visual acuity (VA and contrast sensitivity (CS were assessed along with shooting performance in each of seven conditions of simulated impairment and compared to that with habitual vision. Shooting performance was evaluated by calculating each individual’s average score in every level of simulated vision impairment and normalising this score by expressing it as a percentage of the baseline performance achieved with habitual vision. Receiver Operating Characteristic (ROC curves were constructed to evaluate the ability of different VA and CS cut-off criteria to appropriately classify these athletes as achieving ‘expected’ or ‘below expected’ shooting results based on their performance with different levels of VA and CS. Shooting performance remained relatively unaffected by mild decreases in VA and CS, but quickly deteriorated with more moderate losses. The ability of visual function measurements to classify shooting performance was good, with 78% of performances appropriately classified using a cut-off of 0.53 logMAR and 74% appropriately classified using a cut-off of 0.83 logCS. The current inclusion criteria for VI shooting (1.0 logMAR is conservative, maximising the chance of including only those with an impairment that does impact performance, but potentially excluding some who do have a genuine impairment in the sport. A lower level of impairment would include more athletes who do have a genuine impairment but would potentially include those who do not

  9. Serum cystatin C levels in preterm newborns in our setting: Correlation with serum creatinine and preterm pathologies.

    Science.gov (United States)

    Bardallo Cruzado, Leonor; Pérez González, Elena; Martínez Martos, Zoraima; Bermudo Guitarte, Carmen; Granero Asencio, Mercedes; Luna Lagares, Salud; Marín Patón, Mariano; Polo Padilla, Juan

    2015-01-01

    Cystatin C (CysC) is a renal function marker that is not as influenced as creatinine (Cr) by endogenous or exogenous agents, so it is therefore proposed as a marker in preterm infants. To determine serum CysC values in preterm infants during the first week of life, compared to Cr. To analyze alterations caused by prematurity diseases. The design involved a longitudinal, observational study of prospective cohorts. Groups were based on gestational age (GA): Group A (24-27 weeks), Group B (28-33 weeks), Group C (34-36 weeks). Blood samples were collected at birth, within 48-72hours and after 7 days of life. SPSS v.20 software was used. The statistical methods applied included chi-squared test and ANOVA. A total of 109 preterm infants were included in the study. CysC levels were: 1.54mg/L (±0.28) at birth; 1.38mg/L (±0.36) within 48-72hours of life; 1.50mg/L (±0.31) after 7 days (p<0.05). Cr levels were: 0.64mg/dL (±0.17) at birth; 0.64mg/dL (±0.28) within 48-72hours; 0.56mg/dL (±0.19) after 7 days (P<.05). CysC values were lower in hypotensive patients and those with a respiratory disease (P<.05), and no alterations associated with other diseases were observed. There were no differences in Cr levels associated with any disease. Creatinine levels were higher in patients ≤1.500g (P<.05). Serum CysC decreased within 48-72hours of life, and this decline showed significance (P<.05). The levels increased after 7 days in all 3 GA groups, and there was no difference in CysC levels among the groups. More studies in preterm infants with hypotension and respiratory disease are required. CysC is a better glomerular filtration (GF) marker in ≤1.500g preterm infants. Copyright © 2015 The Authors. Published by Elsevier España, S.L.U. All rights reserved.

  10. What do we mean when we talk about the Triple Aim? A systematic review of evolving definitions and adaptations of the framework at the health system level.

    Science.gov (United States)

    Mery, Gustavo; Majumder, Shilpi; Brown, Adalsteinn; Dobrow, Mark J

    2017-06-01

    Notwithstanding important contributions of the Triple Aim, uncritical enthusiasm regarding the implications of the framework may be leading to inconsistent use, particularly when applied at the health system level, which goes beyond the original positioning of the framework as a strategic organizing principle to guide improvement initiatives at the organizational or local community level. We systematically identified uses of the Triple Aim that extended beyond its original intention to focus on uses at the whole health system level, to assess convergence and divergence with the original definition. We also attempted to identify consistencies in the way the Triple Aim was adapted for different contexts and settings. Data sources were indexed databases, web search engines, and international experts. Forty-seven articles were included in the analysis. We found that the definition of the Triple Aim has been subject to important modifications when the framework is used to define goals for whole health care systems or globally. Despite widespread recognition of the name, what constitutes the Triple Aim framework varies. We identified the need to consider the inclusion of at least two additional aims of health care systems - the provider experience of care, and the desire to achieve health equity for populations. Copyright © 2017. Published by Elsevier B.V.

  11. Mean-level personality development across childhood and adolescence: a temporary defiance of the maturity principle and bidirectional associations with parenting.

    Science.gov (United States)

    Van den Akker, Alithe L; Deković, Maja; Asscher, Jessica; Prinzie, Peter

    2014-10-01

    In this study, we investigated mean-level personality development in children from 6 to 20 years of age. Additionally, we investigated longitudinal, bidirectional associations between child personality and maternal overreactive and warm parenting. In this 5-wave study, mothers reported on their child's personality from Time 1 (T1) through Time 4 (T4), and children provided self-reports from Time 2 (T2) through Time 5 (T5). Mothers reported on their levels of overreactive and warm parenting from T2 through T4. Using cohort-sequential latent growth curve modeling, we investigated mother reported child personality from 6 to 17 years of age and child reported personality from 9 to 20 years of age. Extraversion decreased linearly across the entire study. Benevolence and conscientiousness increased from middle to late childhood, temporarily declined from late childhood to mid-adolescence, and increased again thereafter. Imagination decreased from middle childhood to mid-adolescence and also increased thereafter. Mothers reported a temporary decline in emotional stability with an increase thereafter, whereas children did not. Boys and girls differed in mean-levels of the personality dimensions and, to a lesser extent, in the degree and direction of changes. Latent difference score modeling showed that child personality predicted changes in parenting and that, to a lesser extent, parenting predicted changes in child traits. Additionally, changes in child personality were associated with changes in maternal parenting. Results of the present study show that personality change is not directed at increasing maturity from childhood to mid-adolescence and that it elicits and is shaped by both positive and negative parenting. 2014 APA, all rights reserved

  12. Development of a working set of waste package performance criteria for deepsea disposal of low-level radioactive waste. Final report

    International Nuclear Information System (INIS)

    Columbo, P.; Fuhrmann, M.; Neilson, R.M. Jr; Sailor, V.L.

    1982-11-01

    The United States ocean dumping regulations developed pursuant to PL92-532, the Marine Protection, Research, and Sanctuaries Act of 1972, as amended, provide for a general policy of isolation and containment of low-level radioactive waste after disposal into the ocean. In order to determine whether any particular waste packaging system is adequate to meet this general requirement, it is necessary to establish a set of performance criteria against which to evaluate a particular packaging system. These performance criteria must present requirements for the behavior of the waste in combination with its immobilization agent and outer container in a deepsea environment. This report presents a working set of waste package performance criteria, and includes a glossary of terms, characteristics of low-level radioactive waste, radioisotopes of importance in low-level radioactive waste, and a summary of domestic and international regulations which control the ocean disposal of these wastes

  13. The politics of agenda setting at the global level: key informant interviews regarding the International Labour Organization Decent Work Agenda.

    Science.gov (United States)

    Di Ruggiero, Erica; Cohen, Joanna E; Cole, Donald C

    2014-07-01

    Global labour markets continue to undergo significant transformations resulting from socio-political instability combined with rises in structural inequality, employment insecurity, and poor working conditions. Confronted by these challenges, global institutions are providing policy guidance to protect and promote the health and well-being of workers. This article provides an account of how the International Labour Organization's Decent Work Agenda contributes to the work policy agendas of the World Health Organization and the World Bank. This qualitative study involved semi-structured interviews with representatives from three global institutions--the International Labour Organization (ILO), the World Health Organization and the World Bank. Of the 25 key informants invited to participate, 16 took part in the study. Analysis for key themes was followed by interpretation using selected agenda setting theories. Interviews indicated that through the Decent Work Agenda, the International Labour Organization is shaping the global policy narrative about work among UN agencies, and that the pursuit of decent work and the Agenda were perceived as important goals with the potential to promote just policies. The Agenda was closely linked to the World Health Organization's conception of health as a human right. However, decent work was consistently identified by World Bank informants as ILO terminology in contrast to terms such as job creation and job access. The limited evidence base and its conceptual nature were offered as partial explanations for why the Agenda has yet to fully influence other global institutions. Catalytic events such as the economic crisis were identified as creating the enabling conditions to influence global work policy agendas. Our evidence aids our understanding of how an issue like decent work enters and stays on the policy agendas of global institutions, using the Decent Work Agenda as an illustrative example. Catalytic events and policy

  14. The politics of agenda setting at the global level: key informant interviews regarding the International Labour Organization Decent Work Agenda

    Science.gov (United States)

    2014-01-01

    Background Global labour markets continue to undergo significant transformations resulting from socio-political instability combined with rises in structural inequality, employment insecurity, and poor working conditions. Confronted by these challenges, global institutions are providing policy guidance to protect and promote the health and well-being of workers. This article provides an account of how the International Labour Organization’s Decent Work Agenda contributes to the work policy agendas of the World Health Organization and the World Bank. Methods This qualitative study involved semi-structured interviews with representatives from three global institutions – the International Labour Organization (ILO), the World Health Organization and the World Bank. Of the 25 key informants invited to participate, 16 took part in the study. Analysis for key themes was followed by interpretation using selected agenda setting theories. Results Interviews indicated that through the Decent Work Agenda, the International Labour Organization is shaping the global policy narrative about work among UN agencies, and that the pursuit of decent work and the Agenda were perceived as important goals with the potential to promote just policies. The Agenda was closely linked to the World Health Organization’s conception of health as a human right. However, decent work was consistently identified by World Bank informants as ILO terminology in contrast to terms such as job creation and job access. The limited evidence base and its conceptual nature were offered as partial explanations for why the Agenda has yet to fully influence other global institutions. Catalytic events such as the economic crisis were identified as creating the enabling conditions to influence global work policy agendas. Conclusions Our evidence aids our understanding of how an issue like decent work enters and stays on the policy agendas of global institutions, using the Decent Work Agenda as an illustrative

  15. Leveling up: enabling diverse users to locate and effectively use unfamiliar data sets through NCAR's Research Data Archive

    Science.gov (United States)

    Peng, G. S.

    2016-12-01

    Research necessarily expands upon the volume and variety of data used in prior work. Increasingly, investigators look outside their primary areas of expertise for data to incorporate into their research. Locating and using the data that they need, which may be described in terminology from other fields of science or be encoded in unfamiliar data formats, present often insurmountable barriers for potential users. As a data provider of a diverse collection of over 600 atmospheric and oceanic data sets (DS) (http://rda.ucar.edu), we seek to reduce or remove those barriers. Serving a broadening and increasing user base with fixed and finite resources requires automation. Our software harvests metadata descriptors about the data from the data files themselves. Data curators/subject matter experts augment the machine-generated metadata as needed. Metadata powers our data search tools. Users may search for data in a myriad of ways ranging from free text queries to GCMD keywords to faceted searches capable of narrowing down selections by specific criteria. Users are offered customized lists of DSs fitting their criteria with links to DS main information pages that provide detailed information about each DS. Where appropriate, they link to the NCAR Climate Data Guide for expert guidance about strengths and weaknesses of that particular DS. Once users find the data sets they need, we provide modular lessons for common data tasks. The lessons may be data tool install guides, data recipes, blog posts, or short YouTube videos. Rather than overloading users with reams of information, we provide targeted lessons when the user is most receptive, e.g. when they want to use data in an unfamiliar format. We add new material when we discover common points of confusion. Each educational resource is tagged with DS ID numbers so that they are automatically linked with the relevant DSs. How can data providers leverage the work of other data providers? Can a common tagging scheme for data

  16. Systems-Level Annotation of a Metabolomics Data Set Reduces 25 000 Features to Fewer than 1000 Unique Metabolites.

    Science.gov (United States)

    Mahieu, Nathaniel G; Patti, Gary J

    2017-10-03

    When using liquid chromatography/mass spectrometry (LC/MS) to perform untargeted metabolomics, it is now routine to detect tens of thousands of features from biological samples. Poor understanding of the data, however, has complicated interpretation and masked the number of unique metabolites actually being measured in an experiment. Here we place an upper bound on the number of unique metabolites detected in Escherichia coli samples analyzed with one untargeted metabolomics method. We first group multiple features arising from the same analyte, which we call "degenerate features", using a context-driven annotation approach. Surprisingly, this analysis revealed thousands of previously unreported degeneracies that reduced the number of unique analytes to ∼2961. We then applied an orthogonal approach to remove nonbiological features from the data using the 13 C-based credentialing technology. This further reduced the number of unique analytes to less than 1000. Our 90% reduction in data is 5-fold greater than previously published studies. On the basis of the results, we propose an alternative approach to untargeted metabolomics that relies on thoroughly annotated reference data sets. To this end, we introduce the creDBle database ( http://creDBle.wustl.edu ), which contains accurate mass, retention time, and MS/MS fragmentation data as well as annotations of all credentialed features.

  17. The Impact of Video Length on Learning in a Middle-Level Flipped Science Setting: Implications for Diversity Inclusion

    Science.gov (United States)

    Slemmons, Krista; Anyanwu, Kele; Hames, Josh; Grabski, Dave; Mlsna, Jeffery; Simkins, Eric; Cook, Perry

    2018-05-01

    Popularity of videos for classroom instruction has increased over the years due to affordability and user-friendliness of today's digital video cameras. This prevalence has led to an increase in flipped, K-12 classrooms countrywide. However, quantitative data establishing the appropriate video length to foster authentic learning is limited, particularly in middle-level classrooms. We focus on this aspect of video technology in two flipped science classrooms at the middle school level to determine the optimal video length to enable learning, increase retention and support student motivation. Our results indicate that while assessments directly following short videos were slightly higher, these findings were not significantly different from scores following longer videos. While short-term retention of material did not seem to be influenced by video length, longer-term retention for males and students with learning disabilities was higher following short videos compared to long as assessed on summative assessments. Students self-report that they were more engaged, had enhanced focus, and had a perceived higher retention of content following shorter videos. This study has important implications for student learning, application of content, and the development of critical thinking skills. This is particularly paramount in an era where content knowledge is just a search engine away.

  18. A browser-based 3D Visualization Tool designed for comparing CERES/CALIOP/CloudSAT level-2 data sets.

    Science.gov (United States)

    Chu, C.; Sun-Mack, S.; Chen, Y.; Heckert, E.; Doelling, D. R.

    2017-12-01

    In Langley NASA, Clouds and the Earth's Radiant Energy System (CERES) and Moderate Resolution Imaging Spectroradiometer (MODIS) are merged with Cloud-Aerosol Lidar with Orthogonal Polarization (CALIOP) on the Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observation (CALIPSO) and CloudSat Cloud Profiling Radar (CPR). The CERES merged product (C3M) matches up to three CALIPSO footprints with each MODIS pixel along its ground track. It then assigns the nearest CloudSat footprint to each of those MODIS pixels. The cloud properties from MODIS, retrieved using the CERES algorithms, are included in C3M with the matched CALIPSO and CloudSat products along with radiances from 18 MODIS channels. The dataset is used to validate the CERES retrieved MODIS cloud properties and the computed TOA and surface flux difference using MODIS or CALIOP/CloudSAT retrieved clouds. This information is then used to tune the computed fluxes to match the CERES observed TOA flux. A visualization tool will be invaluable to determine the cause of these large cloud and flux differences in order to improve the methodology. This effort is part of larger effort to allow users to order the CERES C3M product sub-setted by time and parameter as well as the previously mentioned visualization capabilities. This presentation will show a new graphical 3D-interface, 3D-CERESVis, that allows users to view both passive remote sensing satellites (MODIS and CERES) and active satellites (CALIPSO and CloudSat), such that the detailed vertical structures of cloud properties from CALIPSO and CloudSat are displayed side by side with horizontally retrieved cloud properties from MODIS and CERES. Similarly, the CERES computed profile fluxes whether using MODIS or CALIPSO and CloudSat clouds can also be compared. 3D-CERESVis is a browser-based visualization tool that makes uses of techniques such as multiple synchronized cursors, COLLADA format data and Cesium.

  19. Economic evaluation and the Jordan Rational Drug List: an exploratory study of national-level priority setting.

    Science.gov (United States)

    Lafi, Rania; Robinson, Suzanne; Williams, Iestyn

    2012-01-01

    To explore the extent of and barriers to the use of economic evaluation in compiling the Jordan Rational Drug List in the health care system of Jordan. The research reported in this article involved a case study of the Jordan Rational Drug List. Data collection methods included semi-structured interviews with decision makers and analysis of secondary documentary sources. The case study was supplemented by additional interviews with a small number of Jordanian academics involved in the production of economic evaluation. The research found that there was no formal requirement for cost-effectiveness information submitted as part of the decision-making process for the inclusion of new technologies on the Jordan Rational Drug List. Both decision makers and academics suggested that economic evidence was not influential in formulary decisions. This is unusual for national formulary bodies. The study identified a number of barriers that prevent substantive and routine use of economic evaluation. While some of these echo findings of previous studies, others-notably the extent to which the sectional interests of clinical groups and commercial (pharmaceutical) industry exert undue influence over decision making-more obviously result from the specific Jordanian context. Economic evaluation was not found to be influential in the Jordan Rational Drug List. Recommendations for improvement include enhancing capacity in relation to generating, accessing, and/or applying health economic analysis to priority setting decisions. There is a further need to incentivize the use of economic evaluation, and this requires that organizational and structural impediments be removed. Copyright © 2012 International Society for Pharmacoeconomics and Outcomes Research (ISPOR). Published by Elsevier Inc. All rights reserved.

  20. The Meaning of Meaning, Etc.

    Science.gov (United States)

    Nilsen, Don L. F.

    This paper attempts to dispel a number of misconceptions about the nature of meaning, namely that: (1) synonyms are words that have the same meanings, (2) antonyms are words that have opposite meanings, (3) homonyms are words that sound the same but have different spellings and meanings, (4) converses are antonyms rather than synonyms, (5)…

  1. Does industry take the susceptible subpopulation of asthmatic individuals into consideration when setting derived no‐effect levels?

    Science.gov (United States)

    Johansson, Mia K. V.; Johanson, Gunnar; Öberg, Mattias

    2016-01-01

    Abstract Asthma, a chronic respiratory disease, can be aggravated by exposure to certain chemical irritants. The objectives were first to investigate the extent to which experimental observations on asthmatic subjects are taken into consideration in connection with the registration process under the EU REACH regulation, and second, to determine whether asthmatics are provided adequate protection by the derived no‐effect levels (DNELs) for acute inhalation exposure. We identified substances for which experimental data on the pulmonary functions of asthmatics exposed to chemicals under controlled conditions are available. The effect concentrations were then compared with DNELs and other guideline and limit values. As of April 2015, only 2.6% of 269 classified irritants had available experimental data on asthmatics. Fourteen of the 22 identified substances with available data were fully registered under REACH and we retrieved 114 reliable studies related to these. Sixty‐three of these studies, involving nine of the 14 substances, were cited by the REACH registrants. However, only 17 of the 114 studies, involving four substances, were regarded as key studies. Furthermore, many of the DNELs for acute inhalation were higher than estimated effect levels for asthmatics, i.e., lowest observed adverse effect concentrations or no‐observed adverse effect concentrations, indicating low or no safety margin. We conclude that REACH registrants tend to disregard findings on asthmatics when deriving these DNELs. In addition, we found examples of DNELs, particularly among those derived for workers, which likely do not provide adequate protection for asthmatics. Copyright © 2016 The Authors Journal of Applied Toxicology Published by John Wiley & Sons Ltd. PMID:27283874

  2. Influence of Mean Rooftop-Level Estimation Method on Sensible Heat Flux Retrieved from a Large-Aperture Scintillometer Over a City Centre

    Science.gov (United States)

    Zieliński, Mariusz; Fortuniak, Krzysztof; Pawlak, Włodzimierz; Siedlecki, Mariusz

    2017-08-01

    The sensible heat flux ( H) is determined using large-aperture scintillometer (LAS) measurements over a city centre for eight different computation scenarios. The scenarios are based on different approaches of the mean rooftop-level (zH) estimation for the LAS path. Here, zH is determined separately for wind directions perpendicular (two zones) and parallel (one zone) to the optical beam to reflect the variation in topography and building height on both sides of the LAS path. Two methods of zH estimation are analyzed: (1) average building profiles; (2) weighted-average building height within a 250 m radius from points located every 50 m along the optical beam, or the centre of a certain zone (in the case of a wind direction perpendicular to the path). The sensible heat flux is computed separately using the friction velocity determined with the eddy-covariance method and the iterative procedure. The sensitivity of the sensible heat flux and the extent of the scintillometer source area to different computation scenarios are analyzed. Differences reaching up to 7% between heat fluxes computed with different scenarios were found. The mean rooftop-level estimation method has a smaller influence on the sensible heat flux (-4 to 5%) than the area used for the zH computation (-5 to 7%). For the source-area extent, the discrepancies between respective scenarios reached a similar magnitude. The results demonstrate the value of the approach in which zH is estimated separately for wind directions parallel and perpendicular to the LAS optical beam.

  3. Alteration of Water Pollution Level with the Seasonal Changes in Mean Daily Discharge in Three Main Rivers around Dhaka City, Bangladesh

    Directory of Open Access Journals (Sweden)

    Md. Saiful Islam

    2015-06-01

    Full Text Available A study based on the physicochemical parameters and dissolved metals levels from three main rivers around Dhaka City, Bangladesh, was conducted in order to determine the present pollution status and their alteration trends with the seasonal change of discharge amount. The water samples were collected from the rivers Buriganga, Turag, and Shitalakkhya during both dry and monsoon seasons. Physicochemical analyses revealed that most of the water quality parameters exceeded the recommended levels set by the Department of Environment (DoE, Bangladesh, during both the dry and monsoon seasons. A very strong positive correlation was found between biochemical oxygen demand (BOD and chemical oxygen demand (COD in all sampling points. Both BOD and COD values had a strong negative correlation with dissolved oxygen (DO in the Shitalakkhya River. Most of the dissolved metals concentrations in the water samples were similar. However, the concentrations of different physicochemical properties varied with the seasons. The dry season had significantly higher contamination loads, which were decreased during the monsoon season. Anthropogenic activities, as well as the variation in river water flow during different seasons were the main reasons for this high degree of water pollution.

  4. A comparative study on seismic response of two unstable rock slopes within same tectonic setting but different activity level

    Science.gov (United States)

    Kleinbrod, Ulrike; Burjánek, Jan; Hugentobler, Marc; Amann, Florian; Fäh, Donat

    2017-12-01

    In this study, the seismic response of two slope instabilities is investigated with seismic ambient vibration analysis. Two similar sites have been chosen: an active deep-seated slope instability at Cuolm da Vi and the geologically, structurally and morphologically similar, but presently not moving Alp Caschlè slope. Both slopes are located at the upper Vorderrheintal (Canton Graubünden, Switzerland). Ambient vibrations were recorded on both slopes and processed by time-frequency polarization and site-to-reference spectral ratio analysis. The data interpretation shows correlations between degree of disintegration of the rock mass and amplification. However, the ambient vibration analysis conducted, does not allow retrieving a resonance frequency that can be related to the total depth of the instability of Cuolm da Vi. Even though seismic waves can be hardly traced in rock instabilities containing open fractures, it was possible to retrieve a dispersion curve and a velocity profile from the array measurement at Cuolm da Vi due to the high level of disintegration of the rock material down to a depth of about 100 m. From the similar amplification pattern at the two sites, we expect a similar structure, indicating that also the slope at Alp Caschlè was active in the past in a similar manner as Cuolm da Vi. However, a smoother increase of amplification with frequency is observed at Alp Caschlè, which might indicate less disintegration of the rock mass in a particular depth range at this site, when comparing to Cuolm da Vi where a high level of disintegration is observed, resulting from the high activity at the slope. From the frequency-dependent amplification, we can distinguish between two parts within both instabilities, one part showing decreasing disintegration of the rock mass with increasing depth, for the other parts less-fractured blocks are observed. Since the block structures are found in the lower part of the instabilities, they might contribute to the

  5. Level of data quality from Health Management Information Systems in a resources limited setting and its associated factors, eastern Ethiopia

    Directory of Open Access Journals (Sweden)

    Kidist Teklegiorgis

    2016-08-01

    Methods: A cross-sectional study was conducted by using structured questionnaires in Dire Dawa Administration health facilities. All unit and/or department heads from all government health facilities were selected. The data was analysed using STATA version 11. Frequency and percentages were computed to present the descriptive findings. Association between variables was computed using binary logistic regression. Results: Over all data quality was found to be 75.3% in unit and/or departments. Trained staff to fill format, decision based on supervisor directives and department heads seek feedback were significantly associated with data quality and their magnitudes were (AOR = 2.253, 95% CI [1.082, 4.692], (AOR = 2.131, 95% CI [1.073, 4.233] and (AOR = 2.481, 95% CI [1.262, 4.876], respectively. Conclusion: Overall data quality was found to be below the national expectation level. Low data quality was found at health posts compared to health centres and hospitals. There was also a shortage of assigned HIS personnel, separate HIS offices, and assigned budgets for HIS across all units and/or departments.

  6. The influence of power and actor relations on priority setting and resource allocation practices at the hospital level in Kenya: a case study.

    Science.gov (United States)

    Barasa, Edwine W; Cleary, Susan; English, Mike; Molyneux, Sassy

    2016-09-30

    Priority setting and resource allocation in healthcare organizations often involves the balancing of competing interests and values in the context of hierarchical and politically complex settings with multiple interacting actor relationships. Despite this, few studies have examined the influence of actor and power dynamics on priority setting practices in healthcare organizations. This paper examines the influence of power relations among different actors on the implementation of priority setting and resource allocation processes in public hospitals in Kenya. We used a qualitative case study approach to examine priority setting and resource allocation practices in two public hospitals in coastal Kenya. We collected data by a combination of in-depth interviews of national level policy makers, hospital managers, and frontline practitioners in the case study hospitals (n = 72), review of documents such as hospital plans and budgets, minutes of meetings and accounting records, and non-participant observations in case study hospitals over a period of 7 months. We applied a combination of two frameworks, Norman Long's actor interface analysis and VeneKlasen and Miller's expressions of power framework to examine and interpret our findings RESULTS: The interactions of actors in the case study hospitals resulted in socially constructed interfaces between: 1) senior managers and middle level managers 2) non-clinical managers and clinicians, and 3) hospital managers and the community. Power imbalances resulted in the exclusion of middle level managers (in one of the hospitals) and clinicians and the community (in both hospitals) from decision making processes. This resulted in, amongst others, perceptions of unfairness, and reduced motivation in hospital staff. It also puts to question the legitimacy of priority setting processes in these hospitals. Designing hospital decision making structures to strengthen participation and inclusion of relevant stakeholders could

  7. Estimation of community-level influenza-associated illness in a low resource rural setting in India.

    Science.gov (United States)

    Saha, Siddhartha; Gupta, Vivek; Dawood, Fatimah S; Broor, Shobha; Lafond, Kathryn E; Chadha, Mandeep S; Rai, Sanjay K; Krishnan, Anand

    2018-01-01

    To estimate rates of community-level influenza-like-illness (ILI) and influenza-associated ILI in rural north India. During 2011, we conducted household-based healthcare utilization surveys (HUS) for any acute medical illness (AMI) in preceding 14days among residents of 28villages of Ballabgarh, in north India. Concurrently, we conducted clinic-based surveillance (CBS) in the area for AMI episodes with illness onset ≤3days and collected nasal and throat swabs for influenza virus testing using real-time polymerase chain reaction. Retrospectively, we applied ILI case definition (measured/reported fever and cough) to HUS and CBS data. We attributed 14days of risk-time per person surveyed in HUS and estimated community ILI rate by dividing the number of ILI cases in HUS by total risk-time. We used CBS data on influenza positivity and applied it to HUS-based community ILI rates by age, month, and clinic type, to estimate the community influenza-associated ILI rates. The HUS of 69,369 residents during the year generated risk-time of 3945 person-years (p-y) and identified 150 (5%, 95%CI: 4-6) ILI episodes (38 ILI episodes/1,000 p-y; 95% CI 32-44). Among 1,372 ILI cases enrolled from clinics, 126 (9%; 95% CI 8-11) had laboratory-confirmed influenza (A (H3N2) = 72; B = 54). After adjusting for age, month, and clinic type, overall influenza-associated ILI rate was 4.8/1,000 p-y; rates were highest among children value of influenza vaccination among target groups.

  8. Diagnostic Cut-Off Levels of Plasma Brain Natriuretic Peptide to Distinguish Left Ventricular Failure in Emergency Setting

    International Nuclear Information System (INIS)

    Hussain, A.; Afridi, F. I.; Lutfi, I. A.

    2014-01-01

    Objective: To determine the diagnostic cut-off values of brain natriuretic (BNP) peptide to establish left ventricular failure in patients presenting with dyspnoea in emergency department. Study Design: Descriptive study. Place and Duration of Study: Ziauddin University Hospital, Karachi, from July to December 2011. Methodology: BNP estimation was done on Axysm analyzer with kit provided by Abbott diagnostics, while the Doppler echocardiography was done on Toshiba style (UICW-660A) using 2.5 MHz and 5.0 MHz probes. Log transformation was done to normalize the original BNP values. A receiver operating curve was plotted to determine the diagnostic cut-off value of BNP which can be used to distinguish CHF from other causes of dyspnoea. Statistical analysis was performed by SPSS version 17. Results: A total of 92 patients presenting with dyspnoea in the emergency department were studied. There were 38/92 (41.3%) males and 54/92 (58.7%) females, and the average age of the study population was 64 A +- 14.1 years. These patients had BNP levels and Doppler echocardiography done. The average BNP was found to be 1117.78 A +- 1445.74 pg/ml. In log transformation, the average was found to be 2.72 A +- 0.58. BNP value of 531 pg/ml was found to be the cut off to distinguish between cardiogenic and non-cardiogenic causes of dyspnoea. Conclusion: BNP value of 531 pg/ml can distinguish CHF from other conditions as a cause of dyspnoea in emergency. (author)

  9. Can we avoid high levels of dose escalation for high-risk prostate cancer in the setting of androgen deprivation?

    Science.gov (United States)

    Shakespeare, Thomas P; Wilcox, Shea W; Aherne, Noel J

    2016-01-01

    Both dose-escalated external beam radiotherapy (DE-EBRT) and androgen deprivation therapy (ADT) improve outcomes in patients with high-risk prostate cancer. However, there is little evidence specifically evaluating DE-EBRT for patients with high-risk prostate cancer receiving ADT, particularly for EBRT doses >74 Gy. We aimed to determine whether DE-EBRT >74 Gy improves outcomes for patients with high-risk prostate cancer receiving long-term ADT. Patients with high-risk prostate cancer were treated on an institutional protocol prescribing 3-6 months neoadjuvant ADT and DE-EBRT, followed by 2 years of adjuvant ADT. Between 2006 and 2012, EBRT doses were escalated from 74 Gy to 76 Gy and then to 78 Gy. We interrogated our electronic medical record to identify these patients and analyzed our results by comparing dose levels. In all, 479 patients were treated with a 68-month median follow-up. The 5-year biochemical disease-free survivals for the 74 Gy, 76 Gy, and 78 Gy groups were 87.8%, 86.9%, and 91.6%, respectively. The metastasis-free survivals were 95.5%, 94.5%, and 93.9%, respectively, and the prostate cancer-specific survivals were 100%, 94.4%, and 98.1%, respectively. Dose escalation had no impact on any outcome in either univariate or multivariate analysis. There was no benefit of DE-EBRT >74 Gy in our cohort of high-risk prostate patients treated with long-term ADT. As dose escalation has higher risks of radiotherapy-induced toxicity, it may be feasible to omit dose escalation beyond 74 Gy in this group of patients. Randomized studies evaluating dose escalation for high-risk patients receiving ADT should be considered.

  10. What do differences between multi-voxel and univariate analysis mean? How subject-, voxel-, and trial-level variance impact fMRI analysis.

    Science.gov (United States)

    Davis, Tyler; LaRocque, Karen F; Mumford, Jeanette A; Norman, Kenneth A; Wagner, Anthony D; Poldrack, Russell A

    2014-08-15

    Multi-voxel pattern analysis (MVPA) has led to major changes in how fMRI data are analyzed and interpreted. Many studies now report both MVPA results and results from standard univariate voxel-wise analysis, often with the goal of drawing different conclusions from each. Because MVPA results can be sensitive to latent multidimensional representations and processes whereas univariate voxel-wise analysis cannot, one conclusion that is often drawn when MVPA and univariate results differ is that the activation patterns underlying MVPA results contain a multidimensional code. In the current study, we conducted simulations to formally test this assumption. Our findings reveal that MVPA tests are sensitive to the magnitude of voxel-level variability in the effect of a condition within subjects, even when the same linear relationship is coded in all voxels. We also find that MVPA is insensitive to subject-level variability in mean activation across an ROI, which is the primary variance component of interest in many standard univariate tests. Together, these results illustrate that differences between MVPA and univariate tests do not afford conclusions about the nature or dimensionality of the neural code. Instead, targeted tests of the informational content and/or dimensionality of activation patterns are critical for drawing strong conclusions about the representational codes that are indicated by significant MVPA results. Copyright © 2014 Elsevier Inc. All rights reserved.

  11. Quantitative characterization of metastatic disease in the spine. Part I. Semiautomated segmentation using atlas-based deformable registration and the level set method

    International Nuclear Information System (INIS)

    Hardisty, M.; Gordon, L.; Agarwal, P.; Skrinskas, T.; Whyne, C.

    2007-01-01

    Quantitative assessment of metastatic disease in bone is often considered immeasurable and, as such, patients with skeletal metastases are often excluded from clinical trials. In order to effectively quantify the impact of metastatic tumor involvement in the spine, accurate segmentation of the vertebra is required. Manual segmentation can be accurate but involves extensive and time-consuming user interaction. Potential solutions to automating segmentation of metastatically involved vertebrae are demons deformable image registration and level set methods. The purpose of this study was to develop a semiautomated method to accurately segment tumor-bearing vertebrae using the aforementioned techniques. By maintaining morphology of an atlas, the demons-level set composite algorithm was able to accurately differentiate between trans-cortical tumors and surrounding soft tissue of identical intensity. The algorithm successfully segmented both the vertebral body and trabecular centrum of tumor-involved and healthy vertebrae. This work validates our approach as equivalent in accuracy to an experienced user

  12. Estimation of community-level influenza-associated illness in a low resource rural setting in India.

    Directory of Open Access Journals (Sweden)

    Siddhartha Saha

    Full Text Available To estimate rates of community-level influenza-like-illness (ILI and influenza-associated ILI in rural north India.During 2011, we conducted household-based healthcare utilization surveys (HUS for any acute medical illness (AMI in preceding 14days among residents of 28villages of Ballabgarh, in north India. Concurrently, we conducted clinic-based surveillance (CBS in the area for AMI episodes with illness onset ≤3days and collected nasal and throat swabs for influenza virus testing using real-time polymerase chain reaction. Retrospectively, we applied ILI case definition (measured/reported fever and cough to HUS and CBS data. We attributed 14days of risk-time per person surveyed in HUS and estimated community ILI rate by dividing the number of ILI cases in HUS by total risk-time. We used CBS data on influenza positivity and applied it to HUS-based community ILI rates by age, month, and clinic type, to estimate the community influenza-associated ILI rates.The HUS of 69,369 residents during the year generated risk-time of 3945 person-years (p-y and identified 150 (5%, 95%CI: 4-6 ILI episodes (38 ILI episodes/1,000 p-y; 95% CI 32-44. Among 1,372 ILI cases enrolled from clinics, 126 (9%; 95% CI 8-11 had laboratory-confirmed influenza (A (H3N2 = 72; B = 54. After adjusting for age, month, and clinic type, overall influenza-associated ILI rate was 4.8/1,000 p-y; rates were highest among children <5 years (13; 95% CI: 4-29 and persons≥60 years (11; 95%CI: 2-30.We present a novel way to use HUS and CBS data to generate estimates of community burden of influenza. Although the confidence intervals overlapped considerably, higher point estimates for burden among young children and older adults shows the utility for exploring the value of influenza vaccination among target groups.

  13. Can we avoid high levels of dose escalation for high-risk prostate cancer in the setting of androgen deprivation?

    Directory of Open Access Journals (Sweden)

    Shakespeare TP

    2016-05-01

    Full Text Available Thomas P Shakespeare,1,2 Shea W Wilcox,1 Noel J Aherne1,2 1Department of Radiation Oncology, North Coast Cancer Institute, 2Rural Clinical School, Faculty of Medicine, University of New South Wales, Coffs Harbour, NSW, Australia Aim: Both dose-escalated external beam radiotherapy (DE-EBRT and androgen deprivation therapy (ADT improve outcomes in patients with high-risk prostate cancer. However, there is little evidence specifically evaluating DE-EBRT for patients with high-risk prostate cancer receiving ADT, particularly for EBRT doses >74 Gy. We aimed to determine whether DE-EBRT >74 Gy improves outcomes for patients with high-risk prostate cancer receiving long-term ADT. Patients and methods: Patients with high-risk prostate cancer were treated on an institutional protocol prescribing 3–6 months neoadjuvant ADT and DE-EBRT, followed by 2 years of adjuvant ADT. Between 2006 and 2012, EBRT doses were escalated from 74 Gy to 76 Gy and then to 78 Gy. We interrogated our electronic medical record to identify these patients and analyzed our results by comparing dose levels. Results: In all, 479 patients were treated with a 68-month median follow-up. The 5-year biochemical disease-free survivals for the 74 Gy, 76 Gy, and 78 Gy groups were 87.8%, 86.9%, and 91.6%, respectively. The metastasis-free survivals were 95.5%, 94.5%, and 93.9%, respectively, and the prostate cancer-specific survivals were 100%, 94.4%, and 98.1%, respectively. Dose escalation had no impact on any outcome in either univariate or multivariate analysis. Conclusion: There was no benefit of DE-EBRT >74 Gy in our cohort of high-risk prostate patients treated with long-term ADT. As dose escalation has higher risks of radiotherapy-induced toxicity, it may be feasible to omit dose escalation beyond 74 Gy in this group of patients. Randomized studies evaluating dose escalation for high-risk patients receiving ADT should be considered. Keywords: radiotherapy, IMRT, dose

  14. [Dot1 and Set2 Histone Methylases Control the Spontaneous and UV-Induced Mutagenesis Levels in the Saccharomyces cerevisiae Yeasts].

    Science.gov (United States)

    Kozhina, T N; Evstiukhina, T A; Peshekhonov, V T; Chernenkov, A Yu; Korolev, V G

    2016-03-01

    In the Saccharomyces cerevisiae yeasts, the DOT1 gene product provides methylation of lysine 79 (K79) of hi- stone H3 and the SET2 gene product provides the methylation of lysine 36 (K36) of the same histone. We determined that the dot1 and set2 mutants suppress the UV-induced mutagenesis to an equally high degree. The dot1 mutation demonstrated statistically higher sensitivity to the low doses of MMC than the wild type strain. The analysis of the interaction between the dot1 and rad52 mutations revealed a considerable level of spontaneous cell death in the double dot1 rad52 mutant. We observed strong suppression of the gamma-in- duced mutagenesis in the set2 mutant. We determined that the dot1 and set2 mutations decrease the sponta- neous mutagenesis rate in both single and d ouble mutants. The epistatic interaction between the dot1 and set2 mutations and almost similar sensitivity of the corresponding mutants to the different types of DNA damage allow one to conclude that both genes are involved in the control of the same DNA repair pathways, the ho- mologous-recombination-based and the postreplicative DNA repair.

  15. Low-level HIV-1 replication and the dynamics of the resting CD4+ T cell reservoir for HIV-1 in the setting of HAART

    Directory of Open Access Journals (Sweden)

    Wilke Claus O

    2008-01-01

    Full Text Available Abstract Background In the setting of highly active antiretroviral therapy (HAART, plasma levels of human immunodeficiency type-1 (HIV-1 rapidly decay to below the limit of detection of standard clinical assays. However, reactivation of remaining latently infected memory CD4+ T cells is a source of continued virus production, forcing patients to remain on HAART despite clinically undetectable viral loads. Unfortunately, the latent reservoir decays slowly, with a half-life of up to 44 months, making it the major known obstacle to the eradication of HIV-1 infection. However, the mechanism underlying the long half-life of the latent reservoir is unknown. The most likely potential mechanisms are low-level viral replication and the intrinsic stability of latently infected cells. Methods Here we use a mathematical model of T cell dynamics in the setting of HIV-1 infection to probe the decay characteristics of the latent reservoir upon initiation of HAART. We compare the behavior of this model to patient derived data in order to gain insight into the role of low-level viral replication in the setting of HAART. Results By comparing the behavior of our model to patient derived data, we find that the viral dynamics observed in patients on HAART could be consistent with low-level viral replication but that this replication would not significantly affect the decay rate of the latent reservoir. Rather than low-level replication, the intrinsic stability of latently infected cells and the rate at which they are reactivated primarily determine the observed reservoir decay rate according to the predictions of our model. Conclusion The intrinsic stability of the latent reservoir has important implications for efforts to eradicate HIV-1 infection and suggests that intensified HAART would not accelerate the decay of the latent reservoir.

  16. Low-level HIV-1 replication and the dynamics of the resting CD4+ T cell reservoir for HIV-1 in the setting of HAART

    Science.gov (United States)

    Sedaghat, Ahmad R; Siliciano, Robert F; Wilke, Claus O

    2008-01-01

    Background In the setting of highly active antiretroviral therapy (HAART), plasma levels of human immunodeficiency type-1 (HIV-1) rapidly decay to below the limit of detection of standard clinical assays. However, reactivation of remaining latently infected memory CD4+ T cells is a source of continued virus production, forcing patients to remain on HAART despite clinically undetectable viral loads. Unfortunately, the latent reservoir decays slowly, with a half-life of up to 44 months, making it the major known obstacle to the eradication of HIV-1 infection. However, the mechanism underlying the long half-life of the latent reservoir is unknown. The most likely potential mechanisms are low-level viral replication and the intrinsic stability of latently infected cells. Methods Here we use a mathematical model of T cell dynamics in the setting of HIV-1 infection to probe the decay characteristics of the latent reservoir upon initiation of HAART. We compare the behavior of this model to patient derived data in order to gain insight into the role of low-level viral replication in the setting of HAART. Results By comparing the behavior of our model to patient derived data, we find that the viral dynamics observed in patients on HAART could be consistent with low-level viral replication but that this replication would not significantly affect the decay rate of the latent reservoir. Rather than low-level replication, the intrinsic stability of latently infected cells and the rate at which they are reactivated primarily determine the observed reservoir decay rate according to the predictions of our model. Conclusion The intrinsic stability of the latent reservoir has important implications for efforts to eradicate HIV-1 infection and suggests that intensified HAART would not accelerate the decay of the latent reservoir. PMID:18171475

  17. Soils - Mean Permeability

    Data.gov (United States)

    Kansas Data Access and Support Center — This digital spatial data set provides information on the magnitude and spatial pattern of depth-weighted, mean soil permeability throughout the State of Kansas. The...

  18. Effect of liner design, pulsator setting, and vacuum level on bovine teat tissue changes and milking characteristics as measured by ultrasonography

    Directory of Open Access Journals (Sweden)

    Gleeson David E

    2004-05-01

    Full Text Available Friesian-type dairy cows were milked with different machine settings to determine the effect of these settings on teat tissue reaction and on milking characteristics. Three teat-cup liner designs were used with varying upper barrel dimensions (wide-bore WB = 31.6 mm; narrow-bore NB = 21.0 mm; narrow-bore NB1 = 25.0 mm. These liners were tested with alternate and simultaneous pulsation patterns, pulsator ratios (60:40 and 67:33 and three system vacuum levels (40, 44 and 50 kPa. Teat tissue was measured using ultrasonography, before milking and directly after milking. The measurements recorded were teat canal length (TCL, teat diameter (TD, cistern diameter (CD and teat wall thickness (TWT. Teat tissue changes were similar with a system vacuum level of either 50 kPa (mid-level or 40 kPa (low-level. Widening the liner upper barrel bore dimension from 21.0 mm (P

  19. Settings for Physical Activity – Developing a Site-specific Physical Activity Behavior Model based on Multi-level Intervention Studies

    DEFF Research Database (Denmark)

    Troelsen, Jens; Klinker, Charlotte Demant; Breum, Lars

    Settings for Physical Activity – Developing a Site-specific Physical Activity Behavior Model based on Multi-level Intervention Studies Introduction: Ecological models of health behavior have potential as theoretical framework to comprehend the multiple levels of factors influencing physical...... to be taken into consideration. A theoretical implication of this finding is to develop a site-specific physical activity behavior model adding a layered structure to the ecological model representing the determinants related to the specific site. Support: This study was supported by TrygFonden, Realdania...... activity (PA). The potential is shown by the fact that there has been a dramatic increase in application of ecological models in research and practice. One proposed core principle is that an ecological model is most powerful if the model is behavior-specific. However, based on multi-level interventions...

  20. Population Size Predicts Lexical Diversity, but so Does the Mean Sea Level --Why It Is Important to Correctly Account for the Structure of Temporal Data.

    Science.gov (United States)

    Koplenig, Alexander; Müller-Spitzer, Carolin

    2016-01-01

    In order to demonstrate why it is important to correctly account for the (serial dependent) structure of temporal data, we document an apparently spectacular relationship between population size and lexical diversity: for five out of seven investigated languages, there is a strong relationship between population size and lexical diversity of the primary language in this country. We show that this relationship is the result of a misspecified model that does not consider the temporal aspect of the data by presenting a similar but nonsensical relationship between the global annual mean sea level and lexical diversity. Given the fact that in the recent past, several studies were published that present surprising links between different economic, cultural, political and (socio-)demographical variables on the one hand and cultural or linguistic characteristics on the other hand, but seem to suffer from exactly this problem, we explain the cause of the misspecification and show that it has profound consequences. We demonstrate how simple transformation of the time series can often solve problems of this type and argue that the evaluation of the plausibility of a relationship is important in this context. We hope that our paper will help both researchers and reviewers to understand why it is important to use special models for the analysis of data with a natural temporal ordering.

  1. Accelerating NLTE radiative transfer by means of the Forth-and-Back Implicit Lambda Iteration: A two-level atom line formation in 2D Cartesian coordinates

    Science.gov (United States)

    Milić, Ivan; Atanacković, Olga

    2014-10-01

    State-of-the-art methods in multidimensional NLTE radiative transfer are based on the use of local approximate lambda operator within either Jacobi or Gauss-Seidel iterative schemes. Here we propose another approach to the solution of 2D NLTE RT problems, Forth-and-Back Implicit Lambda Iteration (FBILI), developed earlier for 1D geometry. In order to present the method and examine its convergence properties we use the well-known instance of the two-level atom line formation with complete frequency redistribution. In the formal solution of the RT equation we employ short characteristics with two-point algorithm. Using an implicit representation of the source function in the computation of the specific intensities, we compute and store the coefficients of the linear relations J=a+bS between the mean intensity J and the corresponding source function S. The use of iteration factors in the ‘local’ coefficients of these implicit relations in two ‘inward’ sweeps of 2D grid, along with the update of the source function in other two ‘outward’ sweeps leads to four times faster solution than the Jacobi’s one. Moreover, the update made in all four consecutive sweeps of the grid leads to an acceleration by a factor of 6-7 compared to the Jacobi iterative scheme.

  2. A conditioned level-set method with block-division strategy to flame front extraction based on OH-PLIF measurements

    International Nuclear Information System (INIS)

    Han Yue; Cai Guo-Biao; Xu Xu; Bruno Renou; Abdelkrim Boukhalfa

    2014-01-01

    A novel approach to extract flame fronts, which is called the conditioned level-set method with block division (CLSB), has been developed. Based on a two-phase level-set formulation, the conditioned initialization and region-lock optimization appear to be beneficial to improve the efficiency and accuracy of the flame contour identification. The original block-division strategy enables the approach to be unsupervised by calculating local self-adaptive threshold values autonomously before binarization. The CLSB approach has been applied to deal with a large set of experimental data involving swirl-stabilized premixed combustion in diluted regimes operating at atmospheric pressures. The OH-PLIF measurements have been carried out in this framework. The resulting images are, thus, featured by lower signal-to-noise ratios (SNRs) than the ideal image; relatively complex flame structures lead to significant non-uniformity in the OH signal intensity; and, the magnitude of the maximum OH gradient observed along the flame front can also vary depending on flow or local stoichiometry. Compared with other conventional edge detection operators, the CLSB method demonstrates a good ability to deal with the OH-PLIF images at low SNR and with the presence of a multiple scales of both OH intensity and OH gradient. The robustness to noise sensitivity and intensity inhomogeneity has been evaluated throughout a range of experimental images of diluted flames, as well as against a circle test as Ground Truth (GT). (interdisciplinary physics and related areas of science and technology)

  3. A systematic review on the relationship between the nursing shortage and nurses' job satisfaction, stress and burnout levels in oncology/haematology settings.

    Science.gov (United States)

    Gi, Toh Shir; Devi, Kamala M; Neo Kim, Emily Ang

    2011-01-01

    Nursing shortage is a global issue that which affects oncology nursing. Oncology nurses are more prone to experience job dissatisfaction, stress and burnout when they work in units with poor staffing. There is thus a need for greater understanding of the relationship between the nursing shortage and nursing outcomes in oncology/haematology settings. This review aimed to establish the best available evidence concerning the relationship between the nursing shortage and nurses' job satisfaction, stress and burnout levels in oncology/haematology settings; and to make recommendations for practice and future research. Types of participants: This review considered studies that included oncology registered nurses (RNs) who were more than 18 years of age and worked in either inpatient or outpatient oncology/haematology wards or units for the adult or paediatric patients.Types of intervention: This review considered studies that evaluated the relationship between the nursing shortage and nurses' job satisfaction, stress and burnout levels in oncology/haematology settings.Types of outcomes: This review included studies that measured job satisfaction, stress and burnout levels using different outcomes measures. Job satisfaction was determined by the Measure of Job Satisfaction scale, the Misener Nurse Practitioner Job Satisfaction Scale and the Likert scale, stress by the Pediatric Oncology Nurse Stressor Questionnaire and burnout by the Maslash Burnout Inventory scale.Types of studies: This review included descriptive/descriptive-correlational studies which were published in English. The search strategy sought to identify published and unpublished studies conducted between 1990 and 2010. Using a three-step search strategy, the following databases were accessed: CINAHL, Medline, Scopus, ScienceDirect, PsycInfo, PsycArticles, Web of Science, The Cochrane Library, Proquest and Mednar. Two independent reviewers assessed each paper for methodological validity prior to inclusion in

  4. Assessment of Current Global and Regional Mean Sea Level Estimates Based on the TOPEX/Poseidon Jason-1 and 2 Climate Data Record

    Science.gov (United States)

    Beckley, B. D.; Lemoine, F. G.; Zelensky, N. P.; Yang, X.; Holmes, S.; Ray, R. D.; Mitchum, G. T.; Desai, S.; Brown, S.; Haines, B.

    2011-01-01

    Recent developments in Precise Orbit Determinations (POD) due to in particular to revisions to the terrestrial reference frame realization and the time variable gravity (TVG) continues to provide improvements to the accuracy and stability of the PO directly affecting mean sea level (MSL) estimates. Long-term credible MSL estimates require the development and continued maintenance of a stable reference frame, along with vigilant monitoring of the performance of the independent tracking systems used to calculate the orbits for altimeter spacecrafts. The stringent MSL accuracy requirements of a few tenths of an mm/yr are particularly essential for mass budget closure analysis over the relative short time period of Jason-l &2, GRACE, and Argo coincident measurements. In an effort to adhere to cross mission consistency, we have generated a full time series of experimental orbits (GSFC stdlllO) for TOPEX/Poseidon (TP), Jason-I, and OSTM based on an improved terrestrial reference frame (TRF) realization (ITRF2008), revised static (GGM03s), and time variable gravity field (Eigen6s). In this presentation we assess the impact of the revised precision orbits on inter-mission bias estimates, and resultant global and regional MSL trends. Tide gauge verification results are shown to assess the current stability of the Jason-2 sea surface height time series that suggests a possible discontinuity initiated in early 2010. Although the Jason-2 time series is relatively short (approximately 3 years), a thorough review of the entire suite of geophysical and environmental range corrections is warranted and is underway to maintain the fidelity of the record.

  5. Coastal lagoon systems as indicator of Holocene sea-level development in a periglacial soft-sediment setting: Samsø, Denmark

    DEFF Research Database (Denmark)

    Sander, Lasse; Fruergaard, Mikkel; Johannessen, Peter N.

    2014-01-01

    . Stratigraphy, grain-size distribution, fossil and organic matter content of cores retrieved from the lagoons were analyzed and compared. Age control was established using radiocarbon and optically stimulated luminescence dating. Our data produced a surprisingly consistent pattern for the sedimentary......Confined shallow-water environments are encountered many places along the coast of the inner Danish waters. Despite their common occurrence, these environments have rarely been studied as sedimentary archives. In this study we set out to trace back changes in relative sea-level and associated...... geomorphological responses in sediment cores retrieved from coastal lagoon systems on the island of Samsø, central Denmark. In the mid-Atlantic period, the post-glacial sea-level rise reached what is today the southern Kattegat Sea. Waves, currents and tides began to erode the unconsolidated moraine material...

  6. Imaging disturbance zones ahead of a tunnel by elastic full-waveform inversion: Adjoint gradient based inversion vs. parameter space reduction using a level-set method

    Directory of Open Access Journals (Sweden)

    Andre Lamert

    2018-03-01

    Full Text Available We present and compare two flexible and effective methodologies to predict disturbance zones ahead of underground tunnels by using elastic full-waveform inversion. One methodology uses a linearized, iterative approach based on misfit gradients computed with the adjoint method while the other uses iterative, gradient-free unscented Kalman filtering in conjunction with a level-set representation. Whereas the former does not involve a priori assumptions on the distribution of elastic properties ahead of the tunnel, the latter introduces a massive reduction in the number of explicit model parameters to be inverted for by focusing on the geometric form of potential disturbances and their average elastic properties. Both imaging methodologies are validated through successful reconstructions of simple disturbances. As an application, we consider an elastic multiple disturbance scenario. By using identical synthetic time-domain seismograms as test data, we obtain satisfactory, albeit different, reconstruction results from the two inversion methodologies. The computational costs of both approaches are of the same order of magnitude, with the gradient-based approach showing a slight advantage. The model parameter space reduction approach compensates for this by additionally providing a posteriori estimates of model parameter uncertainty. Keywords: Tunnel seismics, Full waveform inversion, Seismic waves, Level-set method, Adjoint method, Kalman filter

  7. Geodetic Control Points, Benchmarks; Vertical elevation bench marks for monumented geodetic survey control points for which mean sea level elevations have been determined., Published in 1995, 1:24000 (1in=2000ft) scale, Rhode Island and Providence Plantations.

    Data.gov (United States)

    NSGIC State | GIS Inventory — Geodetic Control Points dataset current as of 1995. Benchmarks; Vertical elevation bench marks for monumented geodetic survey control points for which mean sea level...

  8. Elevated gamma glutamyl transferase levels are associated with the location of acute pulmonary embolism. Cross-sectional evaluation in hospital setting

    Directory of Open Access Journals (Sweden)

    Ozge Korkmaz

    Full Text Available ABSTRACT CONTEXT AND OBJECTIVE: The location of embolism is associated with clinical findings and disease severity in cases of acute pulmonary embolism. The level of gamma-glutamyl transferase increases under oxidative stress-related conditions. In this study, we investigated whether gamma-glutamyl transferase levels could predict the location of pulmonary embolism. DESIGN AND SETTING: Hospital-based cross-sectional study at Cumhuriyet University, Sivas, Turkey. METHODS : 120 patients who were diagnosed with acute pulmonary embolism through computed tomography-assisted pulmonary angiography were evaluated. They were divided into two main groups (proximally and distally located, and subsequently into subgroups according to thrombus localization as follows: first group (thrombus in main pulmonary artery; n = 9; second group (thrombus in main pulmonary artery branches; n = 71; third group (thrombus in pulmonary artery segmental branches; n = 34; and fourth group (thrombus in pulmonary artery subsegmental branches; n = 8. RESULTS : Gamma-glutamyl transferase levels on admission, heart rate, oxygen saturation, right ventricular dilatation/hypokinesia, pulmonary artery systolic pressure and cardiopulmonary resuscitation requirement showed prognostic significance in univariate analysis. The multivariate logistic regression model showed that gamma-glutamyl transferase level on admission (odds ratio, OR = 1.044; 95% confidence interval, CI: 1.011-1.079; P = 0.009 and pulmonary artery systolic pressure (OR = 1.063; 95% CI: 1.005-1.124; P = 0.033 remained independently associated with proximally localized thrombus in pulmonary artery. CONCLUSIONS : The findings revealed a significant association between increased existing embolism load in the pulmonary artery and increased serum gamma-glutamyl transferase levels.

  9. District health manager and mid-level provider perceptions of practice environments in acute obstetric settings in Tanzania: a mixed-method study.

    Science.gov (United States)

    Ng'ang'a, Njoki; Byrne, Mary Woods; Kruk, Margaret E; Shemdoe, Aloisia; de Pinho, Helen

    2016-08-08

    and mid-level providers points to deficient HRH management practices, which contribute to poor practice environments in acute obstetric settings in Tanzania. Our findings indicate that members of CHMTs require additional support to adequately fulfill their HRH management role. Further research conducted in low-income countries is necessary to determine the appropriate package of interventions required to strengthen the capacity of members of CHMTs.

  10. Evaluation of Parallel Level Sets and Bowsher's Method as Segmentation-Free Anatomical Priors for Time-of-Flight PET Reconstruction.

    Science.gov (United States)

    Schramm, Georg; Holler, Martin; Rezaei, Ahmadreza; Vunckx, Kathleen; Knoll, Florian; Bredies, Kristian; Boada, Fernando; Nuyts, Johan

    2018-02-01

    In this article, we evaluate Parallel Level Sets (PLS) and Bowsher's method as segmentation-free anatomical priors for regularized brain positron emission tomography (PET) reconstruction. We derive the proximity operators for two PLS priors and use the EM-TV algorithm in combination with the first order primal-dual algorithm by Chambolle and Pock to solve the non-smooth optimization problem for PET reconstruction with PLS regularization. In addition, we compare the performance of two PLS versions against the symmetric and asymmetric Bowsher priors with quadratic and relative difference penalty function. For this aim, we first evaluate reconstructions of 30 noise realizations of simulated PET data derived from a real hybrid positron emission tomography/magnetic resonance imaging (PET/MR) acquisition in terms of regional bias and noise. Second, we evaluate reconstructions of a real brain PET/MR data set acquired on a GE Signa time-of-flight PET/MR in a similar way. The reconstructions of simulated and real 3D PET/MR data show that all priors were superior to post-smoothed maximum likelihood expectation maximization with ordered subsets (OSEM) in terms of bias-noise characteristics in different regions of interest where the PET uptake follows anatomical boundaries. Our implementation of the asymmetric Bowsher prior showed slightly superior performance compared with the two versions of PLS and the symmetric Bowsher prior. At very high regularization weights, all investigated anatomical priors suffer from the transfer of non-shared gradients.

  11. Gay-Straight Alliances vary on dimensions of youth socializing and advocacy: factors accounting for individual and setting-level differences.

    Science.gov (United States)

    Poteat, V Paul; Scheer, Jillian R; Marx, Robert A; Calzo, Jerel P; Yoshikawa, Hirokazu

    2015-06-01

    Gay-Straight Alliances (GSAs) are school-based youth settings that could promote health. Yet, GSAs have been treated as homogenous without attention to variability in how they operate or to how youth are involved in different capacities. Using a systems perspective, we considered two primary dimensions along which GSAs function to promote health: providing socializing and advocacy opportunities. Among 448 students in 48 GSAs who attended six regional conferences in Massachusetts (59.8 % LGBQ; 69.9 % White; 70.1 % cisgender female), we found substantial variation among GSAs and youth in levels of socializing and advocacy. GSAs were more distinct from one another on advocacy than socializing. Using multilevel modeling, we identified group and individual factors accounting for this variability. In the socializing model, youth and GSAs that did more socializing activities did more advocacy. In the advocacy model, youth who were more actively engaged in the GSA as well as GSAs whose youth collectively perceived greater school hostility and reported greater social justice efficacy did more advocacy. Findings suggest potential reasons why GSAs vary in how they function in ways ranging from internal provisions of support, to visibility raising, to collective social change. The findings are further relevant for settings supporting youth from other marginalized backgrounds and that include advocacy in their mission.

  12. Systematic review on the relationship between the nursing shortage and job satisfaction, stress and burnout levels among nurses in oncology/haematology settings.

    Science.gov (United States)

    Toh, Shir Gi; Ang, Emily; Devi, M Kamala

    2012-06-01

    To establish the best available evidence regarding the relationship between the nursing shortage and nurses' job satisfaction, stress and burnout levels in oncology/haematology settings. Electronic databases (CINAHL, Medline, Scopus, ScienceDirect, PsycInfo, PsycArticles, Web of Science, The Cochrane Library, Proquest and Mednar) were searched using a three-step strategy in order to identify published and unpublished studies conducted between 1990 and 2010. Grey literature was excluded in the review. The identified studies were evaluated using standardised critical appraisal instruments from the Joanna Briggs Institute-Meta Analysis of Statistics Assessment and Review Instrument (JBI-MAStARI). A total of seven descriptive and descriptive-correlational studies published in English were included and data were presented in a narrative summary. Findings revealed a positive bidirectional relationship between the nursing shortage and oncology registered nurses' (RNs') job dissatisfaction, stress and burnout. The extent of the job dissatisfaction, stress and burnout experienced by the oncology RNs and their perception of staffing inadequacy differed according to their demography and work settings. Particularly, nurses who had higher qualifications and positions, who worked full-time and who worked in inpatient settings and non-Magnet hospitals were more likely to attribute staffing inadequacy as one of the main contributing factors for their job dissatisfaction, stress and burnout. This led to a rise in the number of oncology RNs leaving the speciality. Within the constraints of the study and the few quality papers available, it appears that oncology RNs who worked in substandard staffing units often express job dissatisfaction, stress and burnout, which prompt them to seek new employment out of the oncology specialty. This entails a pressing need for organisations to ensure sufficient staffing in oncology/haematology settings, in order to ensure that quality patient care

  13. A level-set method for pathology segmentation in fluorescein angiograms and en face retinal images of patients with age-related macular degeneration

    Science.gov (United States)

    Mohammad, Fatimah; Ansari, Rashid; Shahidi, Mahnaz

    2013-03-01

    The visibility and continuity of the inner segment outer segment (ISOS) junction layer of the photoreceptors on spectral domain optical coherence tomography images is known to be related to visual acuity in patients with age-related macular degeneration (AMD). Automatic detection and segmentation of lesions and pathologies in retinal images is crucial for the screening, diagnosis, and follow-up of patients with retinal diseases. One of the challenges of using the classical level-set algorithms for segmentation involves the placement of the initial contour. Manually defining the contour or randomly placing it in the image may lead to segmentation of erroneous structures. It is important to be able to automatically define the contour by using information provided by image features. We explored a level-set method which is based on the classical Chan-Vese model and which utilizes image feature information for automatic contour placement for the segmentation of pathologies in fluorescein angiograms and en face retinal images of the ISOS layer. This was accomplished by exploiting a priori knowledge of the shape and intensity distribution allowing the use of projection profiles to detect the presence of pathologies that are characterized by intensity differences with surrounding areas in retinal images. We first tested our method by applying it to fluorescein angiograms. We then applied our method to en face retinal images of patients with AMD. The experimental results included demonstrate that the proposed method provided a quick and improved outcome as compared to the classical Chan-Vese method in which the initial contour is randomly placed, thus indicating the potential to provide a more accurate and detailed view of changes in pathologies due to disease progression and treatment.

  14. Monitoring Street-Level Spatial-Temporal Variations of Carbon Monoxide in Urban Settings Using a Wireless Sensor Network (WSN Framework

    Directory of Open Access Journals (Sweden)

    Tzai-Hung Wen

    2013-11-01

    Full Text Available Air pollution has become a severe environmental problem due to urbanization and heavy traffic. Monitoring street-level air quality is an important issue, but most official monitoring stations are installed to monitor large-scale air quality conditions, and their limited spatial resolution cannot reflect the detailed variations in air quality that may be induced by traffic jams. By deploying wireless sensors on crossroads and main roads, this study established a pilot framework for a wireless sensor network (WSN-based real-time monitoring system to understand street-level spatial-temporal changes of carbon monoxide (CO in urban settings. The system consists of two major components. The first component is the deployment of wireless sensors. We deployed 44 sensor nodes, 40 transmitter nodes and four gateway nodes in this study. Each sensor node includes a signal processing module, a CO sensor and a wireless communication module. In order to capture realistic human exposure to traffic pollutants, all sensors were deployed at a height of 1.5 m on lampposts and traffic signs. The study area covers a total length of 1.5 km of Keelung Road in Taipei City. The other component is a map-based monitoring platform for sensor data visualization and manipulation in time and space. Using intensive real-time street-level monitoring framework, we compared the spatial-temporal patterns of air pollution in different time periods. Our results capture four CO concentration peaks throughout the day at the location, which was located along an arterial and nearby traffic sign. The hourly average could reach 5.3 ppm from 5:00 pm to 7:00 pm due to the traffic congestion. The proposed WSN-based framework captures detailed ground information and potential risk of human exposure to traffic-related air pollution. It also provides street-level insights into real-time monitoring for further early warning of air pollution and urban environmental management.

  15. Monitoring street-level spatial-temporal variations of carbon monoxide in urban settings using a wireless sensor network (WSN) framework.

    Science.gov (United States)

    Wen, Tzai-Hung; Jiang, Joe-Air; Sun, Chih-Hong; Juang, Jehn-Yih; Lin, Tzu-Shiang

    2013-11-27

    Air pollution has become a severe environmental problem due to urbanization and heavy traffic. Monitoring street-level air quality is an important issue, but most official monitoring stations are installed to monitor large-scale air quality conditions, and their limited spatial resolution cannot reflect the detailed variations in air quality that may be induced by traffic jams. By deploying wireless sensors on crossroads and main roads, this study established a pilot framework for a wireless sensor network (WSN)-based real-time monitoring system to understand street-level spatial-temporal changes of carbon monoxide (CO) in urban settings. The system consists of two major components. The first component is the deployment of wireless sensors. We deployed 44 sensor nodes, 40 transmitter nodes and four gateway nodes in this study. Each sensor node includes a signal processing module, a CO sensor and a wireless communication module. In order to capture realistic human exposure to traffic pollutants, all sensors were deployed at a height of 1.5 m on lampposts and traffic signs. The study area covers a total length of 1.5 km of Keelung Road in Taipei City. The other component is a map-based monitoring platform for sensor data visualization and manipulation in time and space. Using intensive real-time street-level monitoring framework, we compared the spatial-temporal patterns of air pollution in different time periods. Our results capture four CO concentration peaks throughout the day at the location, which was located along an arterial and nearby traffic sign. The hourly average could reach 5.3 ppm from 5:00 pm to 7:00 pm due to the traffic congestion. The proposed WSN-based framework captures detailed ground information and potential risk of human exposure to traffic-related air pollution. It also provides street-level insights into real-time monitoring for further early warning of air pollution and urban environmental management.

  16. Monitoring Street-Level Spatial-Temporal Variations of Carbon Monoxide in Urban Settings Using a Wireless Sensor Network (WSN) Framework

    Science.gov (United States)

    Wen, Tzai-Hung; Jiang, Joe-Air; Sun, Chih-Hong; Juang, Jehn-Yih; Lin, Tzu-Shiang

    2013-01-01

    Air pollution has become a severe environmental problem due to urbanization and heavy traffic. Monitoring street-level air quality is an important issue, but most official monitoring stations are installed to monitor large-scale air quality conditions, and their limited spatial resolution cannot reflect the detailed variations in air quality that may be induced by traffic jams. By deploying wireless sensors on crossroads and main roads, this study established a pilot framework for a wireless sensor network (WSN)-based real-time monitoring system to understand street-level spatial-temporal changes of carbon monoxide (CO) in urban settings. The system consists of two major components. The first component is the deployment of wireless sensors. We deployed 44 sensor nodes, 40 transmitter nodes and four gateway nodes in this study. Each sensor node includes a signal processing module, a CO sensor and a wireless communication module. In order to capture realistic human exposure to traffic pollutants, all sensors were deployed at a height of 1.5 m on lampposts and traffic signs. The study area covers a total length of 1.5 km of Keelung Road in Taipei City. The other component is a map-based monitoring platform for sensor data visualization and manipulation in time and space. Using intensive real-time street-level monitoring framework, we compared the spatial-temporal patterns of air pollution in different time periods. Our results capture four CO concentration peaks throughout the day at the location, which was located along an arterial and nearby traffic sign. The hourly average could reach 5.3 ppm from 5:00 pm to 7:00 pm due to the traffic congestion. The proposed WSN-based framework captures detailed ground information and potential risk of human exposure to traffic-related air pollution. It also provides street-level insights into real-time monitoring for further early warning of air pollution and urban environmental management. PMID:24287859

  17. Determining Mean Annual Energy Production

    DEFF Research Database (Denmark)

    Kofoed, Jens Peter; Folley, Matt

    2016-01-01

    This robust book presents all the information required for numerical modelling of a wave energy converter, together with a comparative review of the different available techniques. The calculation of the mean annual energy production (MAEP) is critical to the assessment of the levelized cost...... of energy for a wave energy converter or wave farm. Fundamentally, the MAEP is equal to the sum of the product of the power capture of a set of sea-states and their average annual occurrence. In general, it is necessary in the calculation of the MAEP to achieve a balance between computational demand...

  18. Semiautomated hybrid algorithm for estimation of three-dimensional liver surface in CT using dynamic cellular automata and level-sets.

    Science.gov (United States)

    Dakua, Sarada Prasad; Abinahed, Julien; Al-Ansari, Abdulla

    2015-04-01

    Liver segmentation continues to remain a major challenge, largely due to its intense complexity with surrounding anatomical structures (stomach, kidney, and heart), high noise level and lack of contrast in pathological computed tomography (CT) data. We present an approach to reconstructing the liver surface in low contrast CT. The main contributions are: (1) a stochastic resonance-based methodology in discrete cosine transform domain is developed to enhance the contrast of pathological liver images, (2) a new formulation is proposed to prevent the object boundary, resulting from the cellular automata method, from leaking into the surrounding areas of similar intensity, and (3) a level-set method is suggested to generate intermediate segmentation contours from two segmented slices distantly located in a subject sequence. We have tested the algorithm on real datasets obtained from two sources, Hamad General Hospital and medical image computing and computer-assisted interventions grand challenge workshop. Various parameters in the algorithm, such as [Formula: see text], [Formula: see text], [Formula: see text], [Formula: see text], [Formula: see text], [Formula: see