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Sample records for centroid finding method

  1. Centroid finding method for position-sensitive detectors

    International Nuclear Information System (INIS)

    A new centroid finding method for all detectors where the signal charge is collected or induced on strips of wires, or on subdivided resistive electrodes, is presented. The centroid of charge is determined by convolution of the sequentially switched outputs from these subdivisions or from the strips with a linear centroid finding filter. The position line width is inversely proportional to N/sup 3/2/, where N is the number of subdivisions

  2. A new Initial Centroid finding Method based on Dissimilarity Tree for K-means Algorithm

    OpenAIRE

    Kumar, Abhishek; Gupta, Suresh Chandra

    2015-01-01

    Cluster analysis is one of the primary data analysis technique in data mining and K-means is one of the commonly used partitioning clustering algorithm. In K-means algorithm, resulting set of clusters depend on the choice of initial centroids. If we can find initial centroids which are coherent with the arrangement of data, the better set of clusters can be obtained. This paper proposes a method based on the Dissimilarity Tree to find, the better initial centroid as well as ...

  3. Modification of backgammon shape cathode and graded charge division readout method for a novel triple charge division centroid finding method

    International Nuclear Information System (INIS)

    Triple Charge Division (TCD) centroid finding method that uses modified pattern of Backgammon Shape Cathode (MBSC) is introduced for medium range length position sensitive detectors with optimum numbers of cathode segments. MBSC pattern has three separated areas and uses saw tooth like insulator gaps for separating the areas. Side areas of the MBSC pattern are severed by a central common area. Size of the central area is twice of the size of both sides. Whereas central area is the widest area among three, both sides' areas have the main role in position sensing. With the same resolution and linearity, active region of original Backgammon pattern increases twice by using MBSC pattern, and with the same length, linearity of TCD centroid finding is much better than Backgammon charge division readout method. Linearity prediction of TCD centroid finding and experimental results conducted us to find an optimum truncation of the apices of MBCS pattern in the central area. The TCD centroid finding has an especial readout method since charges must be collected from two segments in both sides and from three segments in the central area of MBSC pattern. The so called Graded Charge Division (GCD) is the especial readout method for TCD. The GCD readout is a combination of the charge division readout and sequence grading of serial segments. Position sensing with TCD centroid finding and GCD readout were done by two sizes MBSC patterns (200mm and 80mm) and Spatial resolution about 1% of the detector length is achieved

  4. Modified S2 and Pattern Search Methods to Find Optimal Cluster Centroid for Multi-Variable Functions

    Directory of Open Access Journals (Sweden)

    K. Reddy Madhavi,

    2012-04-01

    Full Text Available Identification of useful clusters in large datasets has attracted considerable interest in clustering process. Since data in the World Wide Web is increasing exponentially that affects on clustering accuracy and decision making, change in the concept between every cluster occurs named concept drift. To detect the difference of cluster distributions between the current data subset and previous clustering result, an algorithm called Drifting Concept Detection (DCD and proper data labeling need to be performed. To say that the data labeling was performed well, generated clusters must be efficient. Selecting initial cluster center (centroid is the key factor that has high affection in generating effective clusters. The data with different properties exists in real world. Previous work was concentrated in the identification of optimal cluster centroid for the functions of multi variables using Simplex Search (S2 method and Pattern Search using Modified Sectioning method. These methods are extended by providing modified S2 and pattern search methods that finds optimal cluster centroid for the multi variable functions and tests for optimality and then apply any existing clustering algorithm to generate clusters.

  5. High-position-resolution scintillation neutron-imaging detector by crossed-fiber readout with novel centroid-finding method

    CERN Document Server

    Katagiri, M; Sakasai, K; Matsubayashi, M; Birumachi, A; Takahashi, H; Nakazawa, M

    2002-01-01

    Aiming at high-position-resolution and high-counting-rate neutron imaging, a novel centroid-finding method is proposed for a scintillation neutron-imaging detector with crossed-fiber readout. Crossed wavelength-shifting fibers are arranged on and under the scintillator. Luminescences generated in the scintillator are emitted and detected by a few fibers surrounding the incident point of a neutron. In the novel method, X and Y positions of the incident neutron are decided by coincidence of a central signal and neighboring signals, respectively. By fundamental experiments using a ZnS:Ag/ sup 6 LiF scintillator of 0.5-mm thickness and crossed wavelength-shifting fibers with a size of 0.5 x 0.5 mm sup 2 , it was confirmed that the position resolution is about 0.5 mm and the limitation of the neutron-counting rate is 320 kcps. (orig.)

  6. Optimum threshold selection method of centroid computation for Gaussian spot

    Science.gov (United States)

    Li, Xuxu; Li, Xinyang; Wang, Caixia

    2015-10-01

    Centroid computation of Gaussian spot is often conducted to get the exact position of a target or to measure wave-front slopes in the fields of target tracking and wave-front sensing. Center of Gravity (CoG) is the most traditional method of centroid computation, known as its low algorithmic complexity. However both electronic noise from the detector and photonic noise from the environment reduces its accuracy. In order to improve the accuracy, thresholding is unavoidable before centroid computation, and optimum threshold need to be selected. In this paper, the model of Gaussian spot is established to analyze the performance of optimum threshold under different Signal-to-Noise Ratio (SNR) conditions. Besides, two optimum threshold selection methods are introduced: TmCoG (using m % of the maximum intensity of spot as threshold), and TkCoG ( using?n +?? n as the threshold), ?n and ?n are the mean value and deviation of back noise. Firstly, their impact on the detection error under various SNR conditions is simulated respectively to find the way to decide the value of k or m. Then, a comparison between them is made. According to the simulation result, TmCoG is superior over TkCoG for the accuracy of selected threshold, and detection error is also lower.

  7. Multiple centroid method to evaluate the adaptability of alfalfa genotypes

    Directory of Open Access Journals (Sweden)

    Moysés Nascimento

    2015-02-01

    Full Text Available This study aimed to evaluate the efficiency of multiple centroids to study the adaptability of alfalfa genotypes (Medicago sativa L.. In this method, the genotypes are compared with ideotypes defined by the bissegmented regression model, according to the researcher's interest. Thus, genotype classification is carried out as determined by the objective of the researcher and the proposed recommendation strategy. Despite the great potential of the method, it needs to be evaluated under the biological context (with real data. In this context, we used data on the evaluation of dry matter production of 92 alfalfa cultivars, with 20 cuttings, from an experiment in randomized blocks with two repetitions carried out from November 2004 to June 2006. The multiple centroid method proved efficient for classifying alfalfa genotypes. Moreover, it showed no unambiguous indications and provided that ideotypes were defined according to the researcher's interest, facilitating data interpretation.

  8. Gaussian Analytic Centroiding method of star image of star tracker

    Science.gov (United States)

    Wang, Haiyong; Xu, Ershuai; Li, Zhifeng; Li, Jingjin; Qin, Tianmu

    2015-11-01

    The energy distribution of an actual star image coincides with the Gaussian law statistically in most cases, so the optimized processing algorithm about star image centroiding should be constructed also by following Gaussian law. For a star image spot covering a certain number of pixels, the marginal distribution of the gray accumulation on rows and columns are shown and analyzed, based on which the formulas of Gaussian Analytic Centroiding method (GAC) are deduced, and the robustness is also promoted due to the inherited filtering effect of gray accumulation. Ideal reference star images are simulated by the PSF (point spread function) with integral form. Precision and speed tests for the Gaussian Analytic formulas are conducted under three scenarios of Gaussian radius (0.5, 0.671, 0.8 pixel), The simulation results show that the precision of GAC method is better than that of the other given algorithms when the Gaussian radius is not bigger than 5 × 5 pixel window, a widely used parameter. Above all, the algorithm which consumes the least time is still the novel GAC method. GAC method helps to promote the comprehensive performance in the attitude determination of a star tracker.

  9. Alteração no método centroide de avaliação da adaptabilidade genotípica Alteration of the centroid method to evaluate genotypic adaptability

    Directory of Open Access Journals (Sweden)

    Moysés Nascimento

    2009-03-01

    Full Text Available O objetivo deste trabalho foi alterar o método centroide de avaliação da adaptabilidade e estabilidade fenotípica de genótipos, para deixá-lo com maior sentido biológico e melhorar aspectos quantitativos e qualitativos de sua análise. A alteração se deu pela adição de mais três ideótipos, definidos de acordo com valores médios dos genótipos nos ambientes. Foram utilizados dados provenientes de um experimento sobre produção de matéria seca de 92 genótipos de alfafa (Medicago sativa realizado em blocos ao acaso, com duas repetições. Os genótipos foram submetidos a 20 cortes, no período de novembro de 2004 a junho de 2006. Cada corte foi considerado um ambiente. A inclusão dos ideótipos de maior sentido biológico (valores médios nos ambientes resultou em uma dispersão gráfica em forma de uma seta voltada para a direita, na qual os genótipos mais produtivos ficaram próximos à ponta da seta. Com a alteração, apenas cinco genótipos foram classificados nas mesmas classes do método centroide original. A figura em forma de seta proporciona uma comparação direta dos genótipos, por meio da formação de um gradiente de produtividade. A alteração no método mantém a facilidade de interpretação dos resultados para a recomendação dos genótipos presente no método original e não permite duplicidade de interpretação dos resultados.ABSTRACT The objective of this work was to modify the centroid method of evaluation of phenotypic adaptability and the phenotype stability of genotypes in order for the method to make greater biological sense and improve its quantitative and qualitative performance. The method was modified by means of the inclusion of three additional ideotypes defined in accordance with the genotypes' average yield in the environments tested. The alfalfa (Medicago sativa L. forage yield of 92 genotypes was used. The trial had a randomized block design, with two replicates, and the data were used to test the method. The genotypes underwent 20 cuts, from November 2004 to June 2006. Each cut was considered an environment. The inclusion of ideotypes of greater biological average production in the environments produced an arrow-shaped graphical dispersion directed to the right in which the most productive genotypes were placed near the tip of the arrow. With the alteration only five genotypes were classified into the former classes of the original centroid method. The arrow-shaped figure allowed a direct comparison of genotypes throughout the productivity gradient. The alteration performed in the method preserved the easy interpretation of results for genotype recommendations of the original method, and does leaves no room for ambiguity in interpretation of the results.

  10. Alteração no método centroide de avaliação da adaptabilidade genotípica / Alteration of the centroid method to evaluate genotypic adaptability

    Scientific Electronic Library Online (English)

    Moysés, Nascimento; Cosme Damião, Cruz; Ana Carolina Mota, Campana; Rafael Simões, Tomaz; Caio Césio, Salgado; Reinaldo de Paula, Ferreira.

    2009-03-01

    Full Text Available O objetivo deste trabalho foi alterar o método centroide de avaliação da adaptabilidade e estabilidade fenotípica de genótipos, para deixá-lo com maior sentido biológico e melhorar aspectos quantitativos e qualitativos de sua análise. A alteração se deu pela adição de mais três ideótipos, definidos [...] de acordo com valores médios dos genótipos nos ambientes. Foram utilizados dados provenientes de um experimento sobre produção de matéria seca de 92 genótipos de alfafa (Medicago sativa) realizado em blocos ao acaso, com duas repetições. Os genótipos foram submetidos a 20 cortes, no período de novembro de 2004 a junho de 2006. Cada corte foi considerado um ambiente. A inclusão dos ideótipos de maior sentido biológico (valores médios nos ambientes) resultou em uma dispersão gráfica em forma de uma seta voltada para a direita, na qual os genótipos mais produtivos ficaram próximos à ponta da seta. Com a alteração, apenas cinco genótipos foram classificados nas mesmas classes do método centroide original. A figura em forma de seta proporciona uma comparação direta dos genótipos, por meio da formação de um gradiente de produtividade. A alteração no método mantém a facilidade de interpretação dos resultados para a recomendação dos genótipos presente no método original e não permite duplicidade de interpretação dos resultados. Abstract in english ABSTRACT The objective of this work was to modify the centroid method of evaluation of phenotypic adaptability and the phenotype stability of genotypes in order for the method to make greater biological sense and improve its quantitative and qualitative performance. The method was modified by means [...] of the inclusion of three additional ideotypes defined in accordance with the genotypes' average yield in the environments tested. The alfalfa (Medicago sativa L.) forage yield of 92 genotypes was used. The trial had a randomized block design, with two replicates, and the data were used to test the method. The genotypes underwent 20 cuts, from November 2004 to June 2006. Each cut was considered an environment. The inclusion of ideotypes of greater biological average production in the environments produced an arrow-shaped graphical dispersion directed to the right in which the most productive genotypes were placed near the tip of the arrow. With the alteration only five genotypes were classified into the former classes of the original centroid method. The arrow-shaped figure allowed a direct comparison of genotypes throughout the productivity gradient. The alteration performed in the method preserved the easy interpretation of results for genotype recommendations of the original method, and does leaves no room for ambiguity in interpretation of the results.

  11. Electronic lifetime measurements with a Ge(Li) detector using the centroid-shift method

    International Nuclear Information System (INIS)

    The centroid-shift method was applied to lifetime measurements using a pulsed beam. A time-centroid spectrum and a mean-life spectrum were created automatically with a minimum of human interference. The method is illustrated with the 98Mo(?,3n)99Ru reaction, in which an isomeric state in 99Ru was found. (Auth.)

  12. A further investigation of the centroid-to-centroid method for stereotactic lung radiotherapy: A phantom study

    Energy Technology Data Exchange (ETDEWEB)

    Lu, Bo; Samant, Sanjiv; Mittauer, Kathryn; Lee, Soyoung; Huang, Yin; Li, Jonathan; Kahler, Darren; Liu, Chihray [Department of Radiation Oncology, University of Florida College of Medicine, Gainesville, Florida 32610 (United States)

    2013-10-15

    Purpose: Our previous study [B. Lu et al., “A patient alignment solution for lung SBRT setups based on a deformable registration technique,” Med. Phys. 39(12), 7379–7389 (2012)] proposed a deformable-registration-based patient setup strategy called the centroid-to-centroid (CTC) method, which can perform an accurate alignment of internal-target-volume (ITV) centroids between averaged four-dimensional computed tomography and cone-beam computed tomography (CBCT) images. Scenarios with variations between CBCT and simulation CT caused by irregular breathing and/or tumor change were not specifically considered in the patient study [B. Lu et al., “A patient alignment solution for lung SBRT setups based on a deformable registration technique,” Med. Phys. 39(12), 7379–7389 (2012)] due to the lack of both a sufficiently large patient data sample and a method of tumor tracking. The aim of this study is to thoroughly investigate and compare the impacts of breathing pattern and tumor change on both the CTC and the translation-only (T-only) gray-value mode strategies by employing a four-dimensional (4D) lung phantom.Methods: A sophisticated anthropomorphic 4D phantom (CIRS Dynamic Thorax Phantom model 008) was employed to simulate all desired respiratory variations. The variation scenarios were classified into four groups: inspiration to expiration ratio (IE ratio) change, tumor trajectory change, tumor position change, tumor size change, and the combination of these changes. For each category the authors designed several scenarios to demonstrate the effects of different levels of breathing variation on both of the T-only and the CTC methods. Each scenario utilized 4DCT and CBCT scans. The ITV centroid alignment discrepancies for CTC and T-only were evaluated. The dose-volume-histograms (DVHs) of ITVs for two extreme cases were analyzed.Results: Except for some extreme cases in the combined group, the accuracy of the CTC registration was about 2 mm for all cases for both the single and the combined scenarios. The performance of the CTC method was insensitive to region-of-registration (ROR) size selections, as suggested by the comparable accuracy between 1 and 2 cm expansions of the ROR selections for the method. The T-only method was suitable for some single scenarios, such as trajectory variation, position variation, and size variation. However, for combined scenarios and/or a large variation in the IE ratio, the T-only method failed to produce reasonable registration results (within 3 mm). The discrepancy was close to, or even greater than, 1 cm. In addition, unlike the CTC method, the T-only method was sensitive to the ROR size selection. The DVH analysis suggested that a large ITV to PTV margin should be considered if a breathing pattern variation is observed.Conclusions: The phantom study demonstrated that the CTC method was reliable for scenarios in which breathing pattern variation was involved. The T-only gray value method worked for some scenarios, but not for scenarios that involved an IE ratio variation. For scenarios involving position variation, the T-only method worked only with a careful selection of the ROR, whereas the CTC method was independent of ROR size as long as the ITVs were included in the ROR. One indication of the dose consequence analysis was that a large ITV to PTV margin should be considered if a breathing pattern variation is observed.

  13. Path integral centroid molecular dynamics method for Bose and Fermi statistics: formalism and simulation

    Science.gov (United States)

    Kinugawa, Kenichi; Nagao, Hidemi; Ohta, Koji

    1999-07-01

    A method is proposed for path integral centroid molecular dynamics (CMD) extended to Bose/Fermi statistics. It is based on the `pseudo-Boltzmann' canonical partition function of quantum statistical mechanics. An extended technique of path integral molecular dynamics (PIMD) is further presented for the calculation of thermodynamic properties and centroid mean force of Bose/Fermi systems. Bosonic PIMD and CMD simulations have been performed for 4He and the ideal Bose gas, respectively. The remnant of ? transition is observed for 4He, while Bose statistics causes a decay of the centroid velocity autocorrelation function of the ideal Bose gas in a nanosecond scale.

  14. Multiple centroid method to evaluate the adaptability of alfalfa genotypes / Metodologia dos centroides múltiplos para avaliação da adaptabilidade em genótipos de alfafa

    Scientific Electronic Library Online (English)

    Moysés, Nascimento; Adésio, Ferreira; Ana Carolina Campana, Nascimento; Fabyano Fonseca e, Silva; Reinaldo de Paula, Ferreira; Cosme Damião, Cruz.

    2015-02-01

    Full Text Available Este trabalho teve como objetivo avaliar a eficiência do método dos centroides múltiplos em um estudo de adaptabilidade de genótipos de alfafa (Medicago sativa L.). Neste método os genótipos são comparados a ideótipos definidos de acordo com o interesse do pesquisador por meio do modelo de regressão [...] bissegmentada. Desta forma a classificação dos genótipos é realizada conforme objetivo do pesquisador e a estratégia de recomendação desejada. Apesar do grande potencial do método há a necessidade que o mesmo seja avaliado sob o aspecto biológico (com dados reais). Assim, diante deste contexto foram utilizados dados provenientes de um experimento em blocos casualizados com 2 repetições, que constituiu-se da avaliação da produção de matéria seca de 92 cultivares de alfafa em 20 cortes, realizados no período de novembro de 2004 a junho de 2006. A metodologia dos Centroides Múltiplos mostrou-se eficiente na classificação de genótipos de alfafa. Além de não apresentar duplicidade de indicações e proporcionar que ideótipos fossem definidos de acordo com o interesse do pesquisador facilitando a interpretação dos dados. Abstract in english This study aimed to evaluate the efficiency of multiple centroids to study the adaptability of alfalfa genotypes (Medicago sativa L.). In this method, the genotypes are compared with ideotypes defined by the bissegmented regression model, according to the researcher's interest. Thus, genotype classi [...] fication is carried out as determined by the objective of the researcher and the proposed recommendation strategy. Despite the great potential of the method, it needs to be evaluated under the biological context (with real data). In this context, we used data on the evaluation of dry matter production of 92 alfalfa cultivars, with 20 cuttings, from an experiment in randomized blocks with two repetitions carried out from November 2004 to June 2006. The multiple centroid method proved efficient for classifying alfalfa genotypes. Moreover, it showed no unambiguous indications and provided that ideotypes were defined according to the researcher's interest, facilitating data interpretation.

  15. The Generalized Centroid Difference method for lifetime measurements via ?-? coincidences using large fast-timing arrays

    Directory of Open Access Journals (Sweden)

    Régis J.-M.

    2015-01-01

    Full Text Available A novel method for direct electronic “fast-timing” lifetime measurements of nuclear excited states via ?-? coincidences using an array equipped with N very fast high-resolution LaBr3(Ce scintillator detectors is presented. The generalized centroid difference method provides two independent “start” and “stop” time spectra obtained without any correction by a superposition of the N(N – 1/2 calibrated ?-? time difference spectra of the N detector fast-timing system. The two fast-timing array time spectra correspond to a forward and reverse gating of a specific ?-? cascade and the centroid difference as the time shift between the centroids of the two time spectra provides a picosecond-sensitive mirror-symmetric observable of the set-up. The energydependent mean prompt response difference between the start and stop events is calibrated and used as a single correction for lifetime determination. These combined fast-timing array mean ?-? zero-time responses can be determined for 40 keV < E? < 1.4 MeV with a precision better than 10 ps using a 152Eu ?-ray source. The new method is described with examples of (n,? and (n,f,? experiments performed at the intense cold-neutron beam facility PF1B of the Institut Laue-Langevin in Grenoble, France, using 16 LaBr3(Ce detectors within the EXILL&FATIMA campaign in 2013. The results are discussed with respect to possible systematic errors induced by background contributions.

  16. A multi-resolution method for climate system modeling: application of Spherical Centroidal A multi-resolution method for climate system modeling: Application of Spherical Centroidal Voroni Tessellations

    Energy Technology Data Exchange (ETDEWEB)

    Ringler, Todd D [Los Alamos National Laboratory; Gunzburger, Max [FLORIDA STATE UNIV; Ju, Lili [UNIV OF SOUTH CAROLINA

    2008-01-01

    During the next decade and beyond, climate system models will be challenged to resolve scales and processes that are far beyond their current scope. Each climate system component has its prototypical example of an unresolved process that may strongly influence the global climate system, ranging from eddy activity within ocean models, to ice streams within ice sheet models, to surface hydrological processes within land system models, to cloud processes within atmosphere models. These new demands will almost certainly result in the develop of multi-resolution schemes that are able, at least regional to faithfully simulate these fine-scale processes. Spherical Centroidal Voronoi Tessellations (SCVTs) offer one potential path toward the development of robust, multi-resolution climate system component models, SCVTs allow for the generation of high quality Voronoi diagrams and Delaunay triangulations through the use of an intuitive, user-defined density function, each of the examples provided, this method results in high-quality meshes where the quality measures are guaranteed to improve as the number of nodes is increased. Real-world examples are developed for the Greenland ice sheet and the North Atlantic ocean. Idealized examples are developed for ocean-ice shelf interaction and for regional atmospheric modeling. In addition to defining, developing and exhibiting SCVTs, we pair this mesh generation technique with a previously developed finite-volume method. Our numerical example is based on the nonlinear shallow-water equations spanning the entire surface of the sphere. This example is used to elucidate both the potential benefits of this multi-resolution method and the challenges ahead.

  17. Comparison of pure and 'Latinized' centroidal Voronoi tessellation against various other statistical sampling methods

    International Nuclear Information System (INIS)

    A recently developed centroidal Voronoi tessellation (CVT) sampling method is investigated here to assess its suitability for use in statistical sampling applications. CVT efficiently generates a highly uniform distribution of sample points over arbitrarily shaped M-dimensional parameter spaces. On several 2-D test problems CVT has recently been found to provide exceedingly effective and efficient point distributions for response surface generation. Additionally, for statistical function integration and estimation of response statistics associated with uniformly distributed random-variable inputs (uncorrelated), CVT has been found in initial investigations to provide superior points sets when compared against latin-hypercube and simple-random Monte Carlo methods and Halton and Hammersley quasi-random sequence methods. In this paper, the performance of all these sampling methods and a new variant ('Latinized' CVT) are further compared for non-uniform input distributions. Specifically, given uncorrelated normal inputs in a 2-D test problem, statistical sampling efficiencies are compared for resolving various statistics of response: mean, variance, and exceedence probabilities

  18. Localization Methods of Weighted Centroid of dBZ on Weather-Radar Echo Maps in Vector Format

    OpenAIRE

    Xue-tao Yu; Xiao-ping Rui; Feng Li

    2013-01-01

    Fast generation of weather-radar echo maps in vector format and accurate localization of weighted centroid of dBZ (dBZ stands for decibels of reflectivity of a radar signal reflected off a remote object) are the basis of studying the characteristic tracking algorithms which are based on the vector echoes. The authors principally studied the approach to generating the vector echo map, and discussed the localization methods of weighted centroid of dBZ on vector echo maps. First, based on the tr...

  19. A walk-free centroid method for lifetime measurements with pulsed beams

    International Nuclear Information System (INIS)

    A delayed-coincidence lifetime measurement method based on a comparison of walk-free centroids of time spectra is presented. The time is measured between the cyclotron rf signal and the pulse from a plastic scintillation detector followed by a fixed energy selection. The events to be time-analyzed are selected from the associated charge-particle spectrum of a silicon detector which is operated in coincidence with the scintillator, i.e. independently of the formation of the signal containing the time information. With this technique, with the micropulse fwhm of typically 500 to 700 ps half-lives down to the 10 ps region can be measured. The following half-lives are obtained with the new method: (160 +- 6) ps for the 2032 keV level in 209Pb; (45 +- 10) ps and (160 +- 20) ps for the 1756.8 keV (02+) and 2027.3 keV (03+) levels in 116Sn, respectively. (Auth.)

  20. Localization Methods of Weighted Centroid of dBZ on Weather-Radar Echo Maps in Vector Format

    Directory of Open Access Journals (Sweden)

    Xue-tao Yu

    2013-02-01

    Full Text Available Fast generation of weather-radar echo maps in vector format and accurate localization of weighted centroid of dBZ (dBZ stands for decibels of reflectivity of a radar signal reflected off a remote object are the basis of studying the characteristic tracking algorithms which are based on the vector echoes. The authors principally studied the approach to generating the vector echo map, and discussed the localization methods of weighted centroid of dBZ on vector echo maps. First, based on the traditional calculation method on raster echo data, some new localization methods of weighted centroid of dBZ on vector echo data were proposed by considering the weights of features’ area and distance from their location to radar center. Second, taking the base reflectivity products of CINRAD/SA weather radar in Meizhou city of China as data sources, they illustrated the storage structure of this type of echo data and studied the drawing mode of changing this type of data into vector format files under the polar coordinate system in detail. Third, using the same vector echo maps created by the above method, the weighted centroid of the same area was calculated by the above localization methods. In the end, Compared with the calculated value of the same area by traditional method which is based on raster echo maps, the three new calculated results and the sources of error were analyzed in detail and two conclusions were drawn: the echo’s precision in vector format is much higher than that in raster format and it is more accurate to take the features’ area and distance to radar center as weights during the calculation of weighted centroid of dBZ on echo maps in vector format.

  1. A multiresolution method for climate system modeling: application of spherical centroidal Voronoi tessellations

    Science.gov (United States)

    Ringler, Todd; Ju, Lili; Gunzburger, Max

    2008-12-01

    During the next decade and beyond, climate system models will be challenged to resolve scales and processes that are far beyond their current scope. Each climate system component has its prototypical example of an unresolved process that may strongly influence the global climate system, ranging from eddy activity within ocean models, to ice streams within ice sheet models, to surface hydrological processes within land system models, to cloud processes within atmosphere models. These new demands will almost certainly result in the develop of multiresolution schemes that are able, at least regionally, to faithfully simulate these fine-scale processes. Spherical centroidal Voronoi tessellations (SCVTs) offer one potential path toward the development of a robust, multiresolution climate system model components. SCVTs allow for the generation of high-quality Voronoi diagrams and Delaunay triangulations through the use of an intuitive, user-defined density function. In each of the examples provided, this method results in high-quality meshes where the quality measures are guaranteed to improve as the number of nodes is increased. Real-world examples are developed for the Greenland ice sheet and the North Atlantic ocean. Idealized examples are developed for ocean-ice shelf interaction and for regional atmospheric modeling. In addition to defining, developing, and exhibiting SCVTs, we pair this mesh generation technique with a previously developed finite-volume method. Our numerical example is based on the nonlinear, shallow-water equations spanning the entire surface of the sphere. This example is used to elucidate both the po tential benefits of this multiresolution method and the challenges ahead.

  2. Centroid Localization of Uncooperative Nodes in Wireless Networks Using a Relative Span Weighting Method

    Directory of Open Access Journals (Sweden)

    Christine Laurendeau

    2010-01-01

    Full Text Available Increasingly ubiquitous wireless technologies require novel localization techniques to pinpoint the position of an uncooperative node, whether the target is a malicious device engaging in a security exploit or a low-battery handset in the middle of a critical emergency. Such scenarios necessitate that a radio signal source be localized by other network nodes efficiently, using minimal information. We propose two new algorithms for estimating the position of an uncooperative transmitter, based on the received signal strength (RSS of a single target message at a set of receivers whose coordinates are known. As an extension to the concept of centroid localization, our mechanisms weigh each receiver's coordinates based on the message's relative RSS at that receiver, with respect to the span of RSS values over all receivers. The weights may decrease from the highest RSS receiver either linearly or exponentially. Our simulation results demonstrate that for all but the most sparsely populated wireless networks, our exponentially weighted mechanism localizes a target node within the regulations stipulated for emergency services location accuracy.

  3. Selection of Initial Centroids for k-Means Algorithm?

    OpenAIRE

    Anand M. Baswade; Prakash S. Nalwade?

    2013-01-01

    Clustering is one of the important data mining techniques. k-Means [1] is one of the mostimportant algorithm for Clustering. Traditional k-Means algorithm selects initial centroids randomly and ink-Means algorithm result of clustering highly depends on selection of initial centroids. k-Means algorithm issensitive to initial centroids so proper selection of initial centroids is necessary. This paper introduces anefficient method to start the k-Means with good initial centroids. Good initial ce...

  4. Centroid Based Text Clustering

    Directory of Open Access Journals (Sweden)

    Priti Maheshwari

    2010-09-01

    Full Text Available Web mining is a burgeoning new field that attempts to glean meaningful information from natural language text. Web mining refers generally to the process of extracting interesting information and knowledge from unstructured text. Text clustering is one of the important Web mining functionalities. Text clustering is the task in which texts are classified into groups of similar objects based on their contents. Current research in the area of Web mining is tacklesproblems of text data representation, classification, clustering, information extraction or the search for and modeling of hidden patterns. In this paper we propose for mining large document collections it is necessary to pre-process the web documents and store the information in a data structure, which is more appropriate for further processing than a plain web file. In this paper we developed a php-mySql based utility to convert unstructured web documents into structured tabular representation by preprocessing, indexing .We apply centroid based web clustering method on preprocessed data. We apply three methods for clustering. Finally we proposed a method that can increase accuracy based on clustering ofdocuments.

  5. Application example: Preliminary Results of ISOLA use to find moment tensor solutions and centroid depth applied to aftershocks of Mw=8.8 February 27 2010, Maule Earthquake

    Science.gov (United States)

    Nacif, S. V.; Sanchez, M. A.

    2013-05-01

    We selected seven aftershocks from Maule earthquake between 33.5°S to 35°S from May to September to find single source inversion. The data were provided by XY Chile Ramp Experiment* which was deployed after great Maule earthquake. Waveform data are from 13 broad band stations chosen from the 58 broad band stations deployed by IRIS-PASCAL from April to September 2010. Stations are placed above the normal subduction section south of ~33.5°S. Events were located with an iterative software called Hypocenter using one dimensional local model, obtained above for the forearc region between 33°S to 35°S. We used ISOLA which is a fortran code with a Matlab interface to obtain moment tensors solutions, optimum position and time of the subevents. Values depth obtained by a grid search of centroid position show range values which are compatibles with the interplate seismogenic zone. Double-Couple focal mechanism solutions (Figure 1) show 4 thrust events which can be associated with that zone. However, only one of them has strike, dip and rake of 358°, 27° and 101 respectively, appropriate to be expected for interplate seismogenic zone. On the other hand, the other 3 events show strike and normal double-couple focal mechanism solutions (Figure 1). This last topic makes association to those events to the contact of the Nazca and South American plate difficult. Nevertheless, in a first stage, their depths may allow possibility of an origin there. * The facilities of the IRIS Data Management System, and specifically the IRIS Data Management Center, were used for access to waveform, metadata or products required in this study. The IRIS DMS is funded through the National Science Foundation and specifically the GEO Directorate through the Instrumentation and Facilities Program of the National Science Foundation under Cooperative Agreement EAR-0552316. Some activities of are supported by the National Science Foundation EarthScope Program under Cooperative Agreement EAR-0733069. Figure 1. Doble-Couple focal mechanisms solutions from Moment Tensor Inversion using ISOLA. Triangles show broad band stations used in this work from IRIS-PASSCAL.

  6. A Robust Front-End Processor combining Mel Frequency Cepstral Coefficient and Sub-band Spectral Centroid Histogram methods for Automatic Speech Recognition

    Directory of Open Access Journals (Sweden)

    R. Thangarajan

    2009-06-01

    Full Text Available Environmental robustness is an important area of research in speech recognition. Mismatch between trained speech models and actual speech to be recognized is due to factors like background noise. It can cause severe degradation in the accuracy of recognizers whichare based on commonly used features like mel-frequency cepstral co-efficient (MFCC and linear predictive coding (LPC. It is well understood that all previous auditory based feature extraction methods perform extremely well in terms of robustness due to the dominantfrequency information present in them. But these methods suffer from high computational cost. Another method called sub-band spectral centroid histograms (SSCH integrates dominant-frequency information with sub-band power information. This method is based onsub-band spectral centroids (SSC which are closely related to spectral peaks for both clean and noisy speech. Since SSC can be computed efficiently from short-term speech power spectrum estimate, SSCH method is quite robust to background additive noise at a lowercomputational cost. It has been noted that MFCC method outperforms SSCH method in the case of clean speech. However in the case of speech with additive noise, MFCC method degrades substantially. In this paper, both MFCC and SSCH feature extraction have beenimplemented in Carnegie Melon University (CMU Sphinx 4.0 and trained and tested on AN4 database for clean and noisy speech. Finally, a robust speech recognizer which automatically employs either MFCC or SSCH feature extraction methods based on the variance of shortterm power of the input utterance is suggested.

  7. The generalized centroid difference method for picosecond sensitive determination of lifetimes of nuclear excited states using large fast-timing arrays

    Energy Technology Data Exchange (ETDEWEB)

    Régis, J.-M., E-mail: regis@ikp.uni-koeln.de [Institut für Kernphysik der Universität zu Köln, Zülpicher Str. 77, 50937 Köln (Germany); Mach, H. [Departamento de Física Atómica y Nuclear, Universidad Complutense, 28040 Madrid (Spain); Simpson, G.S. [Laboratoire de Physique Subatomique et de Cosmologie Grenoble, 53, rue des Martyrs, 38026 Grenoble Cedex (France); Jolie, J.; Pascovici, G.; Saed-Samii, N.; Warr, N. [Institut für Kernphysik der Universität zu Köln, Zülpicher Str. 77, 50937 Köln (Germany); Bruce, A. [School of Computing, Engineering and Mathematics, University of Brighton, Lewes Road, Brighton BN2 4GJ (United Kingdom); Degenkolb, J. [Institut für Kernphysik der Universität zu Köln, Zülpicher Str. 77, 50937 Köln (Germany); Fraile, L.M. [Departamento de Física Atómica y Nuclear, Universidad Complutense, 28040 Madrid (Spain); Fransen, C. [Institut für Kernphysik der Universität zu Köln, Zülpicher Str. 77, 50937 Köln (Germany); Ghita, D.G. [Horia Hulubei National Institute for Physics and Nuclear Engineering, 77125 Bucharest (Romania); and others

    2013-10-21

    A novel method for direct electronic “fast-timing” lifetime measurements of nuclear excited states via ?–? coincidences using an array equipped with N?N equally shaped very fast high-resolution LaBr{sub 3}(Ce) scintillator detectors is presented. Analogous to the mirror symmetric centroid difference method, the generalized centroid difference method provides two independent “start” and “stop” time spectra obtained by a superposition of the N(N?1)?–? time difference spectra of the N detector fast-timing system. The two fast-timing array time spectra correspond to a forward and reverse gating of a specific ?–? cascade. Provided that the energy response and the electronic time pick-off of the detectors are almost equal, a mean prompt response difference between start and stop events is calibrated and used as a single correction for lifetime determination. These combined fast-timing arrays mean ?–? time-walk characteristics can be determined for 40keVmethod over the total dynamic range is mainly determined by the statistics. The setup of an N=4 detector fast-timing array delivered an absolute time resolving power of 3 ps for 10 000 ?–? events per total fast timing array start and stop time spectrum. The new method is tested over the total dynamic range by the measurements of known picosecond lifetimes in standard ?-ray sources.

  8. Noise in position measurement by centroid calculation

    International Nuclear Information System (INIS)

    The position of a particle trajectory in a gaseous (or semiconductor) detector can be measured by calculating the centroid of the induced charge on the cathode plane. The charge amplifiers attached to each cathode strip introduce noise which is added to the signal. This noise broadens the position resolution line. Our article gives an analytical tool to estimate the resolution broadening due to the noise per strip and the number of strips involved in the centroid calculation. It is shown that the position resolution increases faster than the square root of the number of strips involved. We also consider the consequence of added interstrip capacitors, intended to diminish the differential nonlinearity. It is shown that the position error increases slower than linearly with the interstrip capacities, due to the cancellation of correlated noise. The estimation we give, can be applied to calculations of position broadening other than the centroid finding. (orig.)

  9. Weighted Centroid Correction Localization in Cellular Systems

    Directory of Open Access Journals (Sweden)

    Rong-Zheng Li

    2011-01-01

    Full Text Available Problem statement: There is a large demand for wireless Location-Based Service (LBS and it is provided by many wireless cellular systems. In process of positioning a Mobile Station (MS, the computing speed is as important as the positioning accuracy and the algorithm should also be resistant to environmental influences. Approach: A new positioning method based on Weighted Centroid Correction Localization (WCCL for wireless cellular systems is introduced in this article. Firstly, referring to the receiving-state of an MS in cellular systems, it computes a weighted centroid of surrounding Base Stations (BSs as a rough approximate position of the MS. Then, according to the distances between the MS and the BSs being less or bigger than the computed distances between the BSs and the weighted centroid, it corrects the coordinate of the weighted centroid towards the directions of the BSs by moving it closer or farther in turn. Results: According to our experiments, WCCL improves the positioning accuracy, as well as to provide a better resistance to environmental influences. Conclusion: As a modified centroid-based localization algorithm, WCCL obtains weighting factors from the receiving-state of MS in multi-cells structured cellular systems and obtains a better positioning result in cellular systems without updating the network equipment. Therefore, for the cellular positioning problem, WCCL algorithm can be an alternate solution.

  10. Comparação dos métodos de determinação da estabilidade oxidativa de biodiesel B100, em mistura com antioxidantes sintéticos: aplicação do delineamento simplex-centroide com variável de processo Comparison of methods for determination of oxidative stability of B100 biodiesel mixed with synthetic antioxidants: application of simplex-centroid design with process variable

    Directory of Open Access Journals (Sweden)

    João Rafael de Moraes Cini

    2013-01-01

    Full Text Available The Rancimat and accelerated stove tests were used to determine the oxidative stability of B100 biodiesel mixed with synthetic antioxidants. The predictive equations, with process variable, were obtained by applying a simplex-centroid design. Regardless of the antioxidant used, all assays carried out with the accelerated stove test presented storage time longer than 177.88 d, the greatest value obtained by applying the Rancimat test. The t test, applied to the parameters containing the process variable, showed a statistically significant difference (at the level of 5% between the methods used.

  11. Evidence for subduction beneath Gibraltar Arc and Andean regions from k-means earthquake centroids

    Science.gov (United States)

    Ramdani, Faiçal; Kettani, Omar; Tadili, Benaissa

    2015-01-01

    k-Means algorithms are widely used for determining clusters in broad types of datasets. Since zones of high seismic activity as plate boundary present diffuse seismicity patterns, the use of k-algorithm is a way to classify earthquakes in terms of centroids. Mapping centroids improves seismic visibility for further tectonic interpretation. We used selected datasets of earthquakes and determined the number of clusters or values of k by introducing the silhouette index method to check the validity of cluster numbers. By introducing magnitude size in the vectorial attributes, k-means algorithm provides a map of centroids that represents the location of high seismic energy, which is useful in seismic risk assessment. By including the depth of seismic events as the main attribute, we obtained spatiotemporal variations of centroids, which improve the image resolution of seismicity at depth to find out the underlying dynamic process. This has been achieved in subduction zone of Chile where the presence of slab is reflected by centroid distribution. The method is particularly relevant to complex seismic zones where controversial geodynamic models are reported such as the Gibraltar Arc. Resulting model supports W-oriented subduction underlying many parts of the Gibraltar zone.

  12. Quantum spatial superresolution by optical centroid measurements

    OpenAIRE

    Shin, Heedeuk; Chan, Kam Wai Clifford; Chang, Hye Jeong; Robert W. Boyd

    2011-01-01

    Quantum lithography (QL) has been suggested as a means of achieving enhanced spatial resolution for optical imaging, but its realization has been held back by the low multi-photon detection rates of recording materials. Recently, an optical centroid measurement (OCM) procedure was proposed as a way to obtain spatial resolution enhancement identical to that of QL but with higher detection efficiency (M. Tsang, Phys. Rev. Lett. 102, 253601, 2009). Here we describe a variation of the OCM method ...

  13. Statistics of Centroids of Velocity

    CERN Document Server

    Esquivel, A

    2009-01-01

    We review the use of velocity centroids statistics to recover information of interstellar turbulence from observations. Velocity centroids have been used for a long time now to retrieve information about the scaling properties of the turbulent velocity field in the interstellar medium. We show that, while they are useful to study subsonic turbulence, they do not trace the statistics of velocity in supersonic turbulence, because they are highly influenced by fluctuations of density. We show also that for sub-Alfv\\'enic turbulence (both supersonic and subsonic) two-point statistics (e.g. correlation functions or power-spectra) are anisotropic. This anisotropy can be used to determine the direction of the mean magnetic field projected in the plane of the sky.

  14. STATISTICS OF CENTROIDS OF VELOCITY

    Directory of Open Access Journals (Sweden)

    A. Esquivel

    2009-01-01

    Full Text Available We review the use of velocity centroids statistics to recover information of interstellar turbulence from observations. Velocity centroids have been used for a long time now to retrieve information about the scaling properties of the turbulent velocity field in the interstellar medium. We show that, while they are useful to study subsonic turbulence, they do not trace the statistics of velocity in supersonic turbulence, because they are highly influenced by fluctuations of density. We show also that for sub-Alfvénic turbulence (both supersonic and subsonic two-point statistics (e.g. correlation functions or power-spectra are anisotropic. This anisotropy can be used to determine the direction of the mean magnetic field projected in the plane of the sky.

  15. Quantum spatial superresolution by optical centroid measurements

    CERN Document Server

    Shin, Heedeuk; Chang, Hye Jeong; Boyd, Robert W

    2011-01-01

    Quantum lithography (QL) has been suggested as a means of achieving enhanced spatial resolution for optical imaging, but its realization has been held back by the low multi-photon detection rates of recording materials. Recently, an optical centroid measurement (OCM) procedure was proposed as a way to obtain spatial resolution enhancement identical to that of QL but with higher detection efficiency (M. Tsang, Phys. Rev. Lett. 102, 253601, 2009). Here we describe a variation of the OCM method with still higher detection efficiency based on the use of photon-number-resolving detection. We also report laboratory results for two-photon interference. We compare these results with those of the standard QL method based on multi-photon detection and show that the new method leads to superresolution but with higher detection efficiency.

  16. Intelligent systems for analyzing soccer games: The weighted centroid / Sistemas Inteligentes para el análisis de fútbol: centroide ponderado

    Scientific Electronic Library Online (English)

    F, Clemente; M, Santos-Couceiro; F, Lourenço-Martins; R, Sousa; A, Figueiredo.

    2014-12-01

    Full Text Available Nuevos sistemas inteligentes se han desarrollado recientemente, con el fin de mejorar la calidad de análisis del partido. Estos sistemas basan su análisis en el comportamiento táctico de los equipos, sin embargo, todos los métodos innovadores necesitan algunos cambios para aumentar su potencial en l [...] as implicaciones prácticas. Por lo tanto, el objetivo principal de este trabajo es proponer una actualización del centroide y métrica del equipo, teniendo en cuenta a todos los jugadores del equipo y también la posición de la bola, además, tiene como objetivo analizar la relación entre los centroides de los equipos oponentes. Un partido de fútbol 11, fue analizado con el fin de aplicar el nuevo algoritmo del centroide; los principales resultados mostraron una fuerte evidencia de la relación positiva entre centroides en el eje x (r s = 0.781) y el eje y (r s = 0.0707). Este estudio, confirma trabajos previos que analizaron la relación positiva y fuerte entre equipos centroides. Además, fue posible demostrar la pertinencia de la nueva actualización de métrica táctica y su importancia para el aumento de la información en las aplicaciones prácticas durante el partido. Abstract in english New, intelligent systems have been developed recently to improve the quality of match analysis. These systems analyze the tactical behavior of the teams. However, the existing methods leave room for improvement. Thus, the main goal of this study is to refine the team centroid metric by considering a [...] ll of the players on the team and the ball position. Furthermore, this study analyzes the relationship between the centroids of the two opposing teams. One 11-on-11 soccer match was analyzed to test the new centroid algorithm. The results provided strong evidence of the positive relation between the centroids of the two teams over time in the x-axis (r s = 0.781) and the y-axis (r s = 0.0707). This study confirmed the results of previous studies that analyzed the relationship between team centroids. Furthermore, it was possible to prove the effectiveness of the new tactical metric and its relevance for adding information during a match.

  17. FINGERPRINT MATCHING BASED ON PORE CENTROIDS

    Directory of Open Access Journals (Sweden)

    S. Malathi

    2011-05-01

    Full Text Available In recent years there has been exponential growth in the use of bio- metrics for user authentication applications. Automated Fingerprint Identification systems have become popular tool in many security and law enforcement applications. Most of these systems rely on minutiae (ridge ending and bifurcation features. With the advancement in sensor technology, high resolution fingerprint images (1000 dpi pro- vide micro level of features (pores that have proven to be useful fea- tures for identification. In this paper, we propose a new strategy for fingerprint matching based on pores by reliably extracting the pore features The extraction of pores is done by Marker Controlled Wa- tershed segmentation method and the centroids of each pore are con- sidered as feature vectors for matching of two fingerprint images. Experimental results shows that the proposed method has better per- formance with lower false rates and higher accuracy.

  18. Estimating the Doppler centroid of SAR data

    DEFF Research Database (Denmark)

    Madsen, Søren Nørvang

    1989-01-01

    After reviewing frequency-domain techniques for estimating the Doppler centroid of synthetic-aperture radar (SAR) data, the author describes a time-domain method and highlights its advantages. In particular, a nonlinear time-domain algorithm called the sign-Doppler estimator (SDE) is shown to have...... attractive properties. An evaluation based on an existing SEASAT processor is reported. The time-domain algorithms are shown to be extremely efficient with respect to requirements on calculations and memory, and hence they are well suited to real-time systems where the Doppler estimation is based on raw SAR...... data. For offline processors where the Doppler estimation is performed on processed data, which removes the problem of partial coverage of bright targets, the ΔE estimator and the CDE (correlation Doppler estimator) algorithm give similar performance. However, for nonhomogeneous scenes it is found that...

  19. Communication: Relation of centroid molecular dynamics and ring-polymer molecular dynamics to exact quantum dynamics

    International Nuclear Information System (INIS)

    We recently obtained a quantum-Boltzmann-conserving classical dynamics by making a single change to the derivation of the “Classical Wigner” approximation. Here, we show that the further approximation of this “Matsubara dynamics” gives rise to two popular heuristic methods for treating quantum Boltzmann time-correlation functions: centroid molecular dynamics (CMD) and ring-polymer molecular dynamics (RPMD). We show that CMD is a mean-field approximation to Matsubara dynamics, obtained by discarding (classical) fluctuations around the centroid, and that RPMD is the result of discarding a term in the Matsubara Liouvillian which shifts the frequencies of these fluctuations. These findings are consistent with previous numerical results and give explicit formulae for the terms that CMD and RPMD leave out

  20. Communication: Relation of centroid molecular dynamics and ring-polymer molecular dynamics to exact quantum dynamics

    Energy Technology Data Exchange (ETDEWEB)

    Hele, Timothy J. H.; Willatt, Michael J.; Muolo, Andrea; Althorpe, Stuart C., E-mail: sca10@cam.ac.uk [Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge CB2 1EW (United Kingdom)

    2015-05-21

    We recently obtained a quantum-Boltzmann-conserving classical dynamics by making a single change to the derivation of the “Classical Wigner” approximation. Here, we show that the further approximation of this “Matsubara dynamics” gives rise to two popular heuristic methods for treating quantum Boltzmann time-correlation functions: centroid molecular dynamics (CMD) and ring-polymer molecular dynamics (RPMD). We show that CMD is a mean-field approximation to Matsubara dynamics, obtained by discarding (classical) fluctuations around the centroid, and that RPMD is the result of discarding a term in the Matsubara Liouvillian which shifts the frequencies of these fluctuations. These findings are consistent with previous numerical results and give explicit formulae for the terms that CMD and RPMD leave out.

  1. GPU-Assisted Computation of Centroidal Voronoi Tessellation

    OpenAIRE

    Rong, Guodong; Liu, Yang; WANG, WENPING; Yin, Xaotian; Gu, Xianfeng; Guo, Xiaohu

    2011-01-01

    Centroidal Voronoi tessellations (CVT) are widely used in computational science and engineering. The most commonly used method is Lloyd's method, and recently the L-BFGS method is shown to be faster than Lloyd's method for computing the CVT. However, these methods run on the CPU and are still too slow for many practical applications. We present techniques to implement these methods on the GPU for computing the CVT on 2D planes and on surfaces, and demonstrate significant speedup of these GPU-...

  2. Orbit extension method for finding unstable orbits

    International Nuclear Information System (INIS)

    The orbit extension method is a technique for building long orbits from shorter ones. Combined with Newton's method, it gives a powerful and efficient tool for finding various orbits of area-preserving twist maps on a cylinder. It is particularly valuable for unstable orbits. This method is developed and used to find two kinds of orbits: ordered periodic orbits and principal heteroclinic orbits between two resonances. Flux from one resonance to another is obtained as a by-product of the principal heteroclinic orbits

  3. Comparação dos métodos de determinação da estabilidade oxidativa de biodiesel B100, em mistura com antioxidantes sintéticos: aplicação do delineamento simplex-centroide com variável de processo Comparison of methods for determination of oxidative stability of B100 biodiesel mixed with synthetic antioxidants: application of simplex-centroid design with process variable

    OpenAIRE

    João Rafael de Moraes Cini; Dionísio Borsato; Carmen Luísa Barbosa Guedes; Hágata Cremasco da Silva; Rodolfo Lopes Coppo

    2013-01-01

    The Rancimat and accelerated stove tests were used to determine the oxidative stability of B100 biodiesel mixed with synthetic antioxidants. The predictive equations, with process variable, were obtained by applying a simplex-centroid design. Regardless of the antioxidant used, all assays carried out with the accelerated stove test presented storage time longer than 177.88 d, the greatest value obtained by applying the Rancimat test. The t test, applied to the parameters containing the proces...

  4. Statistical Properties of Line Centroid Velocities and Centroid Velocity Increments in Compressible Turbulence

    OpenAIRE

    Lis, D. C.; Pety, J.; Phillips, T.G.; Falgarone, E.

    1996-01-01

    We have calculated probability density functions (PDFs) of centroid velociti and centroid velocity increments of line profiles computed from the output of a 512 simulation of compressible turbulence. The PDFs of centroid velocities calculated over the whole data cube are roughly Gaussian. On a smaller scale, non-Gaussian PDFs are observed in some cases. However, this is far from being the rule, and most of the distributions show relatively minor deviations from a Gaussian. By contrast, PDFs o...

  5. Estimating the Doppler centroid of SAR data

    DEFF Research Database (Denmark)

    Madsen, SØren NØrvang

    1989-01-01

    After reviewing frequency-domain techniques for estimating the Doppler centroid of synthetic-aperture radar (SAR) data, the author describes a time-domain method and highlights its advantages. In particular, a nonlinear time-domain algorithm called the sign-Doppler estimator (SDE) is shown to have attractive properties. An evaluation based on an existing SEASAT processor is reported. The time-domain algorithms are shown to be extremely efficient with respect to requirements on calculations and memory, and hence they are well suited to real-time systems where the Doppler estimation is based on raw SAR data. For offline processors where the Doppler estimation is performed on processed data, which removes the problem of partial coverage of bright targets, the ?E estimator and the CDE (correlation Doppler estimator) algorithm give similar performance. However, for nonhomogeneous scenes it is found that the nonlinear SDE algorithm, which estimates the Doppler-shift on the basis of data signs alone, gives superior performance

  6. The Burbea-Rao and Bhattacharyya centroids

    CERN Document Server

    Nielsen, Frank

    2010-01-01

    We study the centroid with respect to the class of information-theoretic distortion measures called Burbea-Rao divergences. Burbea-Rao divergences generalize the Jensen-Shannon divergence by measuring the non-negative Jensen difference induced by a strictly convex and differentiable function expressing a measure of entropy. We first show that a symmetrization of Bregman divergences called Jensen-Bregman distances yields a natural definition of Burbea-Rao divergences. We then define skew Burbea-Rao divergences, and prove that skew Burbea-Rao divergences amount to compute Bregman divergences in asymptotical cases. We prove that Burbea-Rao centroids are always unique, and we design a generic iterative algorithm for efficiently estimating those centroids with guaranteed convergence. In statistics, the Bhattacharyya distance is widely used to measure the degree of overlap of probability distributions. This distance notion is all the more useful as it provides both upper and lower bounds on Bayes misclassification ...

  7. Determination of Star Bodies from -Centroid Bodies

    Indian Academy of Sciences (India)

    Lujun Guo; Gangsong Leng

    2013-11-01

    In this paper, we prove that an origin-symmetric star body is uniquely determined by its -centroid body. Furthermore, using spherical harmonics, we establish a result for non-symmetric star bodies. As an application, we show that there is a unique member of $\\Gamma_p\\langle K \\rangle$ characterized by having larger volume than any other member, for all real $p \\geq 1$ that are not even natural numbers, where $\\Gamma_p\\langle K \\rangle$ denotes the -centroid equivalence class of the star body .

  8. Maser Source Finding Methods in HOPS

    CERN Document Server

    Walsh, Andrew J; Longmore, Steven; Jordan, Christopher H; Lowe, Vicki

    2011-01-01

    The {\\bf H}$_2${\\bf O} Southern Galactic {\\bf P}lane {\\bf S}urvey (HOPS) has observed 100 square degrees of the Galactic plane, using the Mopra radio telescope to search for emission from multiple spectral lines in the 12\\,mm band (19.5\\,--\\,27.5\\,GHz). Perhaps the most important of these spectral lines is the 22.2\\,GHz water maser transition. We describe the methods used to identify water maser candidates and subsequent confirmation of the sources. Our methods involve a simple determination of likely candidates by searching peak emission maps, utilising the intrinsic nature of water maser emission - spatially unresolved and spectrally narrow-lined. We estimate completeness limits and compare our method with results from the {\\sc Duchamp} source finder. We find that the two methods perform similarly. We conclude that the similarity in performance is due to the intrinsic limitation of the noise characteristics of the data. The advantages of our method are that it is slightly more efficient in eliminating spuri...

  9. Improving the Initial Centroids of k-means Clustering Algorithm to Generalize its Applicability

    Science.gov (United States)

    Goyal, M.; Kumar, S.

    2014-12-01

    k-means is one of the most widely used partition based clustering algorithm. But the initial centroids generated randomly by the k-means algorithm cause the algorithm to converge at the local optimum. So to make k-means algorithm globally optimum, the initial centroids must be selected carefully rather than randomly. Though many researchers have already been carried out for the enhancement of k-means algorithm, they have their own limitations. In this paper a new method to formulate the initial centroids is proposed which results in better clusters equally for uniform and non-uniform data sets.

  10. Foot Bone in Vivo: Its Center of Mass and Centroid of Shape

    CERN Document Server

    Fan, Yifang; Fan, Yubo; Lin, Zhiyu; Lv, Changsheng

    2010-01-01

    This paper studies foot bone geometrical shape and its mass distribution and establishes an assessment method of bone strength. Using spiral CT scanning, with an accuracy of sub-millimeter, we analyze the data of 384 pieces of foot bones in vivo and investigate the relationship between the bone's external shape and internal structure. This analysis is explored on the bases of the bone's center of mass and its centroid of shape. We observe the phenomenon of superposition of center of mass and centroid of shape fairly precisely, indicating a possible appearance of biomechanical organism. We investigate two aspects of the geometrical shape, (i) distance between compact bone's centroid of shape and that of the bone and (ii) the mean radius of the same density bone issue relative to the bone's centroid of shape. These quantities are used to interpret the influence of different physical exercises imposed on bone strength, thereby contributing to an alternate assessment technique to bone strength.

  11. Radiographic measures of thoracic kyphosis in osteoporosis: Cobb and vertebral centroid angles

    Energy Technology Data Exchange (ETDEWEB)

    Briggs, A.M.; Greig, A.M. [University of Melbourne, Centre for Health, Exercise and Sports Medicine, School of Physiotherapy, Victoria (Australia); University of Melbourne, Department of Medicine, Royal Melbourne Hospital, Victoria (Australia); Wrigley, T.V.; Tully, E.A.; Adams, P.E.; Bennell, K.L. [University of Melbourne, Centre for Health, Exercise and Sports Medicine, School of Physiotherapy, Victoria (Australia)

    2007-08-15

    Several measures can quantify thoracic kyphosis from radiographs, yet their suitability for people with osteoporosis remains uncertain. The aim of this study was to examine the validity and reliability of the vertebral centroid and Cobb angles in people with osteoporosis. Lateral radiographs of the thoracic spine were captured in 31 elderly women with osteoporosis. Thoracic kyphosis was measured globally (T1-T12) and regionally (T4-T9) using Cobb and vertebral centroid angles. Multisegmental curvature was also measured by fitting polynomial functions to the thoracic curvature profile. Canonical and Pearson correlations were used to examine correspondence; agreement between measures was examined with linear regression. Moderate to high intra- and inter-rater reliability was achieved (SEM = 0.9-4.0 ). Concurrent validity of the simple measures was established against multisegmental curvature (r = 0.88-0.98). Strong association was observed between the Cobb and centroid angles globally (r = 0.84) and regionally (r = 0.83). Correspondence between measures was moderate for the Cobb method (r = 0.72), yet stronger for the centroid method (r = 0.80). The Cobb angle was 20% greater for regional measures due to the influence of endplate tilt. Regional Cobb and centroid angles are valid and reliable measures of thoracic kyphosis in people with osteoporosis. However, the Cobb angle is biased by endplate tilt, suggesting that the centroid angle is more appropriate for this population. (orig.)

  12. Radiographic measures of thoracic kyphosis in osteoporosis: Cobb and vertebral centroid angles

    International Nuclear Information System (INIS)

    Several measures can quantify thoracic kyphosis from radiographs, yet their suitability for people with osteoporosis remains uncertain. The aim of this study was to examine the validity and reliability of the vertebral centroid and Cobb angles in people with osteoporosis. Lateral radiographs of the thoracic spine were captured in 31 elderly women with osteoporosis. Thoracic kyphosis was measured globally (T1-T12) and regionally (T4-T9) using Cobb and vertebral centroid angles. Multisegmental curvature was also measured by fitting polynomial functions to the thoracic curvature profile. Canonical and Pearson correlations were used to examine correspondence; agreement between measures was examined with linear regression. Moderate to high intra- and inter-rater reliability was achieved (SEM = 0.9-4.0 ). Concurrent validity of the simple measures was established against multisegmental curvature (r = 0.88-0.98). Strong association was observed between the Cobb and centroid angles globally (r = 0.84) and regionally (r 0.83). Correspondence between measures was moderate for the Cobb method (r 0.72), yet stronger for the centroid method (r = 0.80). The Cobb angle was 20% greater for regional measures due to the influence of endplate tilt. Regional Cobb and centroid angles are valid and reliable measures of thoracic kyphosis in people with osteoporosis. However, the Cobb angle is biased by endplate tilt, suggesting that the centroid angle is more appropriate for this population. (orig.)

  13. Maser Source Finding Methods in HOPS

    OpenAIRE

    Andrew J. Walsh; Purcell, Cormac; Longmore, Steven; Jordan, Christopher H.; Lowe, Vicki

    2011-01-01

    The {\\bf H}$_2${\\bf O} Southern Galactic {\\bf P}lane {\\bf S}urvey (HOPS) has observed 100 square degrees of the Galactic plane, using the Mopra radio telescope to search for emission from multiple spectral lines in the 12\\,mm band (19.5\\,--\\,27.5\\,GHz). Perhaps the most important of these spectral lines is the 22.2\\,GHz water maser transition. We describe the methods used to identify water maser candidates and subsequent confirmation of the sources. Our methods involve a sim...

  14. Centroid Velocity Statistics of Molecular Clouds

    CERN Document Server

    Bertram, Erik; Shetty, Rahul; Glover, Simon C O; Klessen, Ralf S

    2014-01-01

    We compute structure functions and Fourier spectra of 2D centroid velocity (CV) maps in order to study the gas dynamics of typical molecular clouds (MCs) in numerical simulations. We account for a simplified treatment of time-dependent chemistry and the non-isothermal nature of the gas and use a 3D radiative transfer tool to model the CO line emission in a post-processing step. We perform simulations using three different initial mean number densities of n_0 = 30, 100 and 300 cm^{-3} to span a range of typical values for dense gas clouds in the solar neighbourhood. We compute slopes of the centroid velocity increment structure functions (CVISF) and of Fourier spectra for different chemical components: the total density, H2 number density, 12CO number density as well as the integrated intensity of 12CO (J=1-0) and 13CO (J=1-0). We show that optical depth effects can significantly affect the slopes derived for the CVISF, which also leads to different scaling properties for the Fourier spectra. The slopes of CVI...

  15. Centroid velocity statistics of molecular clouds

    Science.gov (United States)

    Bertram, Erik; Konstandin, Lukas; Shetty, Rahul; Glover, Simon C. O.; Klessen, Ralf S.

    2015-02-01

    We compute structure functions and Fourier spectra of 2D centroid velocity maps in order to study the gas dynamics of typical molecular clouds in numerical simulations. We account for a simplified treatment of time-dependent chemistry and the non-isothermal nature of the gas and use a 3D radiative transfer tool to model the CO line emission in a post-processing step. We perform simulations using three different initial mean number densities of n0 = 30, 100 and 300 cm-3 to span a range of typical values for dense gas clouds in the solar neighbourhood. We compute slopes of the centroid velocity increment structure functions (CVISF) and of Fourier spectra for different chemical components: the total density, H2 number density, 12CO number density as well as the integrated intensity of 12CO (J = 1 ? 0) and 13CO (J = 1 ? 0). We show that optical depth effects can significantly affect the slopes derived for the CVISF, which also leads to different scaling properties for the Fourier spectra. The slopes of CVISF and Fourier spectra for H2 are significantly steeper than those for the different CO tracers, independent of the density and the numerical resolution. This is due to the larger space-filling factor of H2 as it is better able to self-shield in diffuse regions, leading to a larger fractal co-dimension compared to CO.

  16. An Automatic Method of Finding Topic Boundaries

    OpenAIRE

    Reynar, Jeffrey C.

    1994-01-01

    This article outlines a new method of locating discourse boundaries based on lexical cohesion and a graphical technique called dotplotting. The application of dotplotting to discourse segmentation can be performed either manually, by examining a graph, or automatically, using an optimization algorithm. The results of two experiments involving automatically locating boundaries between a series of concatenated documents are presented. Areas of application and future directions...

  17. Numerical Methods for Finding Stationary Gravitational Solutions

    CERN Document Server

    Dias, Oscar J C; Way, Benson

    2015-01-01

    The wide applications of higher dimensional gravity and gauge/gravity duality have fuelled the search for new stationary solutions of the Einstein equation (possibly coupled to matter). In this topical review, we explain the mathematical foundations and give a practical guide for the numerical solution of gravitational boundary value problems. We present these methods by way of example: resolving asymptotically flat black rings, singly-spinning lumpy black holes in anti-de Sitter (AdS), and the Gregory-Laflamme zero modes of small rotating black holes in AdS$_5\\times S^5$. We also include several tools and tricks that have been useful throughout the literature.

  18. The Schrödinger formulation of the Feynman path centroid density

    CERN Document Server

    Ramírez, R; Ram\\'irez, Rafael; López-Ciudad, Telesforo

    1999-01-01

    We present an analysis of the Feynman path centroid density that provides new insight into the correspondence between the path integral and the Schrödinger formulations of statistical mechanics. The path centroid density is a central concept for several approximations (centroid molecular dynamics, quantum transition state theory, and pure quantum self-consistent harmonic approximation) that are used in path integral studies of thermodynamic and dynamical properties of quantum particles. The centroid density is related to the quasi-static response of the equilibrium system to an external force. The path centroid dispersion is the canonical correlation of the position operator, that measures the linear change in the mean position of a quantum particle upon the application of a constant external force. At low temperatures, this quantity provides an approximation to the excitation energy of the quantum system. In the zero temperature limit, the particle's probability density obtained by fixed centroid path integ...

  19. Hierarchical Bayesian Inversion for the Centroid Moment Tensor

    Science.gov (United States)

    Mustac, M.; Tkalcic, H.

    2014-12-01

    Kinematic point source inversions using data from complex tectonic settings (e.g. geothermal or volcanic areas and mines) often result in large non-double-couple components. Examining events with mechanisms more complex than shear motion on a planar fault requires a sophisticated inversion method. We have developed a technique within the probabilistic Bayesian framework that combines previous knowledge about the mechanism with the information from the data and results in a posterior probability distribution for the model parameters. It is capable of yielding parameter uncertainties, which cannot be analytically calculated for a non-linear inversion that includes the source location. The code uses time-series of displacements of regional earthquakes and explosions with moderate magnitudes to compute the centroid location and the seismic moment tensor. The noise is also treated as an unknown in the inversion, in order to determine the level of data fit. As a result, the model complexity (i.e. the contribution of isotropic and compensated linear vector dipole components) is determined by the data themself. Furthermore, the noise weights the contribution of each waveform and the noise covariance matrix accounts for both observational and theoretical errors. The code has been extensively tested in synthetic experiments with a variety of focal mechanisms and different types of noise added to synthetic waveforms. It showed fast convergence of the centroid location, accompanied with thorough sampling of the moment tensor parameters leading to narrow posterior distributions. Subsequently, it is being applied to waveforms from earthquakes that occurred in various tectonic environments.

  20. Accurate Alignment of Plasma Channels Based on Laser Centroid Oscillations

    Energy Technology Data Exchange (ETDEWEB)

    Gonsalves, Anthony; Nakamura, Kei; Lin, Chen; Osterhoff, Jens; Shiraishi, Satomi; Schroeder, Carl; Geddes, Cameron; Toth, Csaba; Esarey, Eric; Leemans, Wim

    2011-03-23

    A technique has been developed to accurately align a laser beam through a plasma channel by minimizing the shift in laser centroid and angle at the channel outptut. If only the shift in centroid or angle is measured, then accurate alignment is provided by minimizing laser centroid motion at the channel exit as the channel properties are scanned. The improvement in alignment accuracy provided by this technique is important for minimizing electron beam pointing errors in laser plasma accelerators.

  1. Rapid determinations of centroid moment tensor in Turkey

    Science.gov (United States)

    Nakano, Masaru; Citak, Seckin; Kalafat, Dogan

    2015-04-01

    Rapid determination of centroid moment tensor (CMT) of earthquakes, namely the source centroid location, focal mechanism, and magnitude is important for early disaster responses and issuing Tsunami warnings. Using the SWIFT system (Source parameter determinations based on Waveform Inversion of Fourier Transformed seismograms) developed by Nakano et al. (2008), we are developing earthquake monitoring system in Turkey. Also determinations of CMT for background seismicity can resolve the stress field in the crust, which may contribute to evaluate potential earthquake, to develop scenarios for future disastrous earthquakes, or to find hidden faults in the crust. Using data from regional network in Turkey, we have tried a waveform inversion for an M=4.4 earthquake that occurred about 50 km south of Sea of Marmara, of which source location is at 40.0N and 27.9E with 15 km depth (after the ANSS Comprehensive Catalog). We successfully obtained the CMT solution showing a right-lateral strike-slip fault, of which one of the nodal planes strikes ENE-WSW, corresponding to the strike of an active fault mapped here. This fault runs parallel to the north Anatolian fault, and large earthquakes of Ms 7.2 and 7.0 ruptured this fault on 1953 and 1964, respectively. Using the regional network data, we can determine CMT for earthquakes as small as magnitude about 4. Of course, the lower limit of magnitude depend on the data quality. In the research project of SATREPS - Earthquake and tsunami disaster mitigation in the Marmara region and disaster education in Turkey, we will develop CMT determination system and CMT catalogue in Turkey.

  2. Optimization of the autocorrelation weighting function for the time-domain calculation of spectral centroids.

    Science.gov (United States)

    Heo, Seo; Hur, Don; Kim, Hyungsuk

    2015-03-01

    Spectral centroid from the backscattered ultrasound provides important information about the attenuation properties of soft tissues and Doppler effects of blood flows. Because the spectral centroid is originally determined from the power spectrum of backscattered ultrasound signals in the frequency domain, it is natural to calculate it after converting time-domain signals into spectral domain signals, using the fast Fourier transform (FFT). Recent research, however, derived the time-domain equations for calculating the spectral centroid using a Parseval's theorem, to avoid the calculation of the Fourier transform. The work only presented the final result, which showed that the computational time of the proposed time-domain method was 4.4 times faster than that of the original FFT-based method, whereas the average estimation error was negligible. In this paper, we present the optimal design of the autocorrelation weighting function, which is used for the timedomain spectral centroid estimation process, to reduce the computational time significantly. We also carry out a comprehensive analysis of the computational complexities of the FFTbased and time-domain methods with respect to the length of ultrasound signal segments. The simulation results using numerical phantoms show that, with the optimized autocorrelation weighting function, we only need approximately 3% of the full set of data points. In addition to that, because the proposed optimization technique requires a fixed number of data points to calculate the spectral centroid, the execution time is constant as the length of the data segment increases, whereas the execution time of the conventional FFT-based method is increased. Analysis of the computational complexities between the proposed method and the conventional FFT-based method presents O(N) and O(Nlog2N), respectively. PMID:25768811

  3. Consolidating boundary methods for finding the eigenstates of billiards

    International Nuclear Information System (INIS)

    The plane-wave decomposition method, a widely used means of numerically finding eigenstates of the Helmholtz equation in billiard systems is described as a variant of the mathematically well-established boundary integral method (BIM). A new unified framework encompassing the two methods is discussed. Furthermore, a third numerical method, which we call the gauge freedom method is derived from the BIM equations. This opens the way to further improvements in eigenstate search techniques

  4. Gridded Population of the World, Version 3 (GPWv3): Centroids

    Data.gov (United States)

    National Aeronautics and Space Administration — Gridded Population of the World, Version 3 (GPWv3) Centroids consists of estimates of human population counts and densities for the years 1990, 1995, 2000, 2005,...

  5. Gridded Population of the World, Version 3 (GPWv3): Centroids

    Data.gov (United States)

    National Aeronautics and Space Administration — Gridded Population of the World, Version 3 (GPWv3) Centroids consists of estimates of human population counts and densities for the years 1990, 1995, 2000, 2005,...

  6. A New Method for Finding Vacua in String Phenomenology

    CERN Document Server

    Gray, J; Ilderton, A; Lukas, A; Gray, James; He, Yang-Hui; Ilderton, Anton; Lukas, Andre

    2007-01-01

    One of the central problems of string-phenomenology is to find stable vacua in the four dimensional effective theories which result from compactification. We present an algorithmic method to find all of the vacua of any given string-phenomenological system in a huge class. In particular, this paper reviews and then extends hep-th/0606122 to include various non-perturbative effects. These include gaugino condensation and instantonic contributions to the superpotential.

  7. A new method for finding vacua in string phenomenology

    Energy Technology Data Exchange (ETDEWEB)

    Gray, James [Institut d' Astrophysique de Paris and APC, Universite de Paris 7, 98 bis, Bd. Arago 75014, Paris (France); He, Yang-Hui [Rudolf Peierls Centre for Theoretical Physics, University of Oxford, 1 Keble Road, Oxford OX1 3NP (United Kingdom)]|[Merton College, Oxford, OX1 4JD and Mathematical Institute, Oxford University, Oxford (United Kingdom); Ilderton, Anton [School of Mathematics and Statistics, University of Plymouth, Drake Circus, Plymouth PL4 8AA (United Kingdom); Lukas, Andre [Rudolf Peierls Centre for Theoretical Physics, University of Oxford, 1 Keble Road, Oxford OX1 3NP (United Kingdom)

    2007-05-15

    One of the central problems of string-phenomenology is to find stable vacua in the four dimensional effective theories which result from compactification. We present an algorithmic method to find all of the vacua of any given string-phenomenological system in a huge class. In particular, this paper reviews and then extends hep-th/0606122 to include various nonperturbative effects. These include gaugino condensation and instantonic contributions to the superpotential. (authors)

  8. Doppler Centroid Estimation for Airborne SAR Supported by POS and DEM

    Directory of Open Access Journals (Sweden)

    CHENG Chunquan

    2015-05-01

    Full Text Available It is difficult to estimate the Doppler frequency and modulating rate for airborne SAR by using traditional vector method due to instable flight and complex terrain. In this paper, it is qualitatively analyzed that the impacts of POS, DEM and their errors on airborne SAR Doppler parameters. Then an innovative vector method is presented based on the range-coplanarity equation to estimate the Doppler centroid taking the POS and DEM as auxiliary data. The effectiveness of the proposed method is validated and analyzed via the simulation experiments. The theoretical analysis and experimental results show that the method can be used to estimate the Doppler centroid with high accuracy even in the cases of high relief, instable flight, and large squint SAR.

  9. Automatic segmentation and centroid detection of skin sensors for lung interventions

    Science.gov (United States)

    Lu, Kongkuo; Xu, Sheng; Xue, Zhong; Wong, Stephen T.

    2012-02-01

    Electromagnetic (EM) tracking has been recognized as a valuable tool for locating the interventional devices in procedures such as lung and liver biopsy or ablation. The advantage of this technology is its real-time connection to the 3D volumetric roadmap, i.e. CT, of a patient's anatomy while the intervention is performed. EM-based guidance requires tracking of the tip of the interventional device, transforming the location of the device onto pre-operative CT images, and superimposing the device in the 3D images to assist physicians to complete the procedure more effectively. A key requirement of this data integration is to find automatically the mapping between EM and CT coordinate systems. Thus, skin fiducial sensors are attached to patients before acquiring the pre-operative CTs. Then, those sensors can be recognized in both CT and EM coordinate systems and used calculate the transformation matrix. In this paper, to enable the EM-based navigation workflow and reduce procedural preparation time, an automatic fiducial detection method is proposed to obtain the centroids of the sensors from the pre-operative CT. The approach has been applied to 13 rabbit datasets derived from an animal study and eight human images from an observation study. The numerical results show that it is a reliable and efficient method for use in EM-guided application.

  10. Findings

    Science.gov (United States)

    ... News & Meetings Science Education About NIGMS NIGMS Home > Science Education > Findings Findings All Issues Featured Scientists Multimedia Puzzles & Quizzes Subscribe Search all issues: Search by issue or topic Print Magazine Subscribe & Order a Free Copy Download PDF Version ...

  11. Plasma Channel Diagnostic Based on Laser Centroid Oscillations

    Energy Technology Data Exchange (ETDEWEB)

    Gonsalves, Anthony; Nakamura, Kei; Lin, Chen; Osterhoff, Jens; Shiraishi, Satomi; Schroeder, Carl; Geddes, Cameron; Toth, Csaba; Esarey, Eric; Leemans, Wim

    2010-09-09

    A technique has been developed for measuring the properties of discharge-based plasma channels by monitoring the centroid location of a laser beam exiting the channel as a function of input alignment offset between the laser and the channel. The centroid position of low-intensity (<10{sup 14}Wcm{sup -2}) laser pulses focused at the input of a hydrogen-filled capillary discharge waveguide was scanned and the exit positions recorded to determine the channel shape and depth with an accuracy of a few %. In addition, accurate alignment of the laser beam through the plasma channel can be provided by minimizing laser centroid motion at the channel exit as the channel depth is scanned either by scanning the plasma density or the discharge timing. The improvement in alignment accuracy provided by this technique will be crucial for minimizing electron beam pointing errors in laser plasma accelerators.

  12. Robust of Doppler Centroid for Mapping Sea Surface Current by Using Radar Satellite Data

    Directory of Open Access Journals (Sweden)

    Mazlan Hashim

    2009-01-01

    Full Text Available Problem statement: Sea surface current retrieving from Synthetic Aperture Radar (SAR is required standard methods due to the complexity of sea surface ocean imaging in SAR data. In this context, various analytical models have been developed which describe overall effects of sea surface roughness on the Doppler signal mechanisms. Nevertheless, such models are limited in the complexity of the sea surface current estimation that can be used. In fact, the resolution of the sea surface Doppler velocity in azimuth direction is typically coarser as compared to the normalized radar cross section image. Approach: This study introduced a new method to retrieve sea surface current from RADARSAT-1 SAR Standard beam mode (S2 data. The method was based on the utilization of the Wavelength Diversity Ambiguity Resolving (WDAR and Multi Look beat Frequency (MLBF algorithms to remove Doppler centroid (fDC ambiguity. Results: The result showed that the proposed methods are able to correct Doppler centroid (fDC ambiguity and produced fine spatial sea surface current variations in S2 mode data. The current velocities were ranged between 0.18 and 0.78 m sec-1 with standard error of 0.11 m sec-1. Conclusion: In conclusion, RADARSAT-1 SAR standard beam mode (S2 data can be utilized to retrieve real time sea surface current. Both WDAR and MLBF algorithms are able to provide accurately information on Doppler Centroid (fDC in which accurately real time sea surface current can be retrieved from SAR data.

  13. Interfractional Variations of Tumor Centroid Position and Tumor Regression during Stereotactic Body Radiotherapy for Lung Tumor

    OpenAIRE

    Yanan Sun; Yufei Lu; Siguo Cheng; Wei Guo; Ke Ye; Huiyun Zhao; Xiaoli Zheng; Dingjie Li; Shujuan Wang; Chengliang Yang; Hong Ge

    2014-01-01

    Purpose. To determine interfractional changes of lung tumor centroid position and tumor regression during stereotactic body radiation therapy (SBRT). Methods and Materials. 34 patients were treated by SBRT in 4-5 fractions to a median dose of 50?Gy. The CT scans acquired for verification were registered with simulation CT scans. The gross target volume (GTV) was contoured on all verification CT scans and compared to the initial GTV in treatment plan system. Results. The mean (±standard deviat...

  14. A Centroid Model for the Depth Assessment of Images using Rough Fuzzy Set Techniques

    Directory of Open Access Journals (Sweden)

    P. Swarnalatha

    2012-04-01

    Full Text Available Detection of affected areas in images is a crucial step in assessing the depth of the affected area for municipal operators. These affected areas in the underground images, which are line images are indicative of the condition of buried infrastructures like sewers and water mains. These images identify affected areas and extract their properties like structures from the images, whose contrast has been enhanced... A Centroid Model for the Depth Assessment of Images using Rough Fuzzy Set Techniques presents a three step method which is a simple, robust and efficient one to detect affected areas in the underground concrete images. The proposed methodology is to use segmentation and feature extraction using structural elements. The main objective for using this model is to find the dimensions of the affected areas such as the length, width, depth and the type of the defects/affected areas. Although human eye is extremely effective at recognition and classification, it is not suitable for assessing defects in images, which might have spread over thousands of miles of image lines. The reasons are mainly fatigue, subjectivity and cost. Our objective is to reduce the effort and the labour of a person in detecting the affected areas in underground images. A proposal to apply rough fuzzy set theory to compute the lower and upper approximations of the affected area of the image is made in this paper. In this connection we propose to use some concepts and technology developed by Pal and Maji.

  15. Bias in the centroid moment tensor for central Asian earthquakes: Evidence from regional surface wave data

    International Nuclear Information System (INIS)

    Surface waves recorded on the Chinese Digital Seismic Network (CDSN) station Urumqi (WMQ) are analyzed for 26 centroid moment tensor (CMT) earthquakes located within an epicentral distance of 1300 km. Applying a simple grid search method for source parameter retrieval, I obtain revised estimates of the focal depth, fault strike, and seismic moment (M0) from amplitude spectra of Love and Rayleigh waves and compare these estimates with the CMT best double-couple solutions. The comparisons show that residuals are unbiased for focal depth and fault strike, where population spreads are ±13 km and ±17 degree, respectively. On the other hand, M0 estimates are found to be biased, with CMT M0 larger than regional estimates by an average of 0.27±0.04 log units. The results for focal depth and strike are consistent with previous global and regional studies comparing independent estimates with CMT results. Recent full-waveform modeling studies for central Asian earthquakes support the findings of bias in M0 estimates. I suggest that causes for M0 bias may be related to great thicknesses of continental crust in Hindu Kush and Tien Shan regions and to data censoring practices at small magnitudes. M0:mb scaling relationships for central Asian earthquakes show better agreement with western U.S. scaling when M0 estimates determined in this study are used. copyright 1998 American Geophysical Union

  16. Preliminary results of centroiding experiment for the STEP mission

    Science.gov (United States)

    Li, Haitao; Li, Baoquan; Cao, Yang; Chen, Ding; Li, Ligang

    2015-08-01

    Search for Terrestrial Exo-Planet (STEP)[1] was originally proposed in 2013 by the National Space Science Center, Chinese Academy of Sciences, which is currently being under background engineering study phase in China. The STEP mission is a space astrometry telescope working at visible light wavelengths. The STEP aims at the nearby terrestrial planets detection through micro-arcsecond-level astrometry. Determination of the separation between star images on a detector with high precision is very important for astrometric exoplanets detection through the observation of star wobbles due to planets. The requirement of centroiding accuracy for STEP is 1e-5 pixel. A centroiding experiment have been carried out on a metrology testbed in open laboratory. In this paper, we present the preliminary results of determining the separations between star images. Without calibration of pixel positions and intra-pixel response, we have demonstrated that the standard deviation of differential centroiding is below 7.4e-3 pixel by the algorithm of linear corrected photon weighted means(LCPWM)[2,3]. For comparison, the photon weighted means(PWM) and Gauss fitting are also used in the data reduction. These results pave the way for the geometrical calibration and the intra-pixel quantum efficiency(QE) calibration of detector array equipment for micro-pixel accuracy centroiding.

  17. A New Halo Finding Method for N-Body Simulations

    CERN Document Server

    Kim, J; Kim, Juhan; Park, Changbom

    2004-01-01

    We have developed a new halo finding method, Physically Self-Bound (PSB) group finding algorithm, which can efficiently identify halos located even at crowded regions. This method combines two physical criteria such as the tidal radius of a halo and the total energy of each particle to find member particles. Two hierarchical meshes are used to increase the speed and the power of halo identification in the parallel computing environments. First, a coarse mesh with cell size equal to the mean particle separation $l_{\\rm mean}$ is used to obtain the density field over the whole simulation box. Mesh cells having density contrast higher than a local cutoff threshold $\\delta_{\\rm LOC}$ are extracted and linked together for those adjacent to each other. This produces local-cell groups. Second, a finer mesh is used to obtain density field within each local-cell group and to identify halos. If a density shell contains only one density peak, its particles are assigned to the density peak. But in the case of a density s...

  18. Optimizing the calculation of point source count-centroid in pixel size measurement

    International Nuclear Information System (INIS)

    Purpose: Pixel size is an important parameter of gamma camera and SPECT. A number of Methods are used for its accurate measurement. In the original count-centroid method, where the image of a point source(PS) is acquired and its count-centroid calculated to represent PS position in the image, background counts are inevitable. Thus the measured count-centroid (Xm) is an approximation of the true count-centroid (Xp) of the PS, i.e. Xm=Xp+(Xb-Xp)/(1+Rp/Rb), where Rp is the net counting rate of the PS, Xb the background count-centroid and Rb the background counting rate. To get accurate measurement, Rp must be very big, which is unpractical, resulting in the variation of measured pixel size. Rp-independent calculation of PS count-centroid is desired. Methods: The proposed method attempted to eliminate the effect of the term (Xb-Xp)/(1+Rp/Rb) by bringing Xb closer to Xp and by reducing Rb. In the acquired PS image, a circular ROI was generated to enclose the PS, the pixel with the maximum count being the center of the ROI. To choose the diameter (D) of the ROI, a Gaussian count distribution was assumed for the PS, accordingly, K=I-(0.5)D/R percent of the total PS counts was in the ROI, R being the full width at half maximum of the PS count distribution. D was set to be 6*R to enclose most (K=98.4%) of the PS counts. The count-centroid of the ROI was calculated to represent Xp. The proposed method was tested in measuring the pixel size of a well-tuned SPECT, whose pixel size was estimated to be 3.02 mm according to its mechanical and electronic setting (128*128 matrix, 387 mm UFOV, ZOOM=1). For comparison, the original method, which was use in the former versions of some commercial SPECT software, was also tested. 12 PSs were prepared and their image acquired and stored. The net counting rate of the PSs increased from 10cps to 1183cps. Results: Using the proposed method, the measured pixel size (in mm) varied only between 3.00 and 3.01( mean= 3.01±0.00) as Rp increased, and the difference between the measured and estimated pixel size was < 1%. While using the original method, the measured pixel size decreased from 23.11 to 3.10 (mean= 7.07±6.35) as Rp increased, and the difference between the measured and estimated pixel size was much bigger. Conclusions: The proposed method is not only Rp-independent, but also accurate and precise. (authors)

  19. Outlier Finding from Clusters using Categorical Data

    OpenAIRE

    Anamika Malaiya; Pradeep Chouskey; Gajendra Vaiker

    2012-01-01

    A New Categorical Data algorithm which combines a systematic method for finding initial centroids and an efficient way for assigning data points to clusters. This method ensures the entire process generate cluster without sacrificing the accuracy. It always generate good cluster by reducing the mean square error. Our clustering algorithm serves as a good benchmark to monitor the progression of student’s performance in institute. It also enhances the decision making by academic planners to mon...

  20. A Doubly Nudged Elastic Band Method for Finding Transition States

    CERN Document Server

    Trygubenko, S A; Trygubenko, Semen A.; Wales, David J.

    2004-01-01

    A modification of the nudged elastic band (NEB) method is presented that enables stable optimisations to be run using both the limited-memory quasi-Newton (L-BFGS) and slow-response quenched velocity Verlet (SQVV) minimisers. The performance of this new `doubly nudged' DNEB method is analysed in conjunction with both minimisers and compared with previous NEB formulations. We find that the fastest DNEB approach (DNEB/L-BFGS) can be quicker by up to two orders of magnitude. Applications to permutational rearrangements of the seven-atom Lennard-Jones cluster (LJ7) and highly cooperative rearrangements of LJ38 and LJ75 are presented. We also outline an updated algorithm for constructing complicated multi-step pathways using successive DNEB runs.

  1. First experimental results of very high accuracy centroiding measurements for the neat astrometric mission

    CERN Document Server

    Crouzier, A; Preis, O; Henault, F; Kern, P; Martin, G; Feautrier, P; Stadler, E; Lafrasse, S; Behar, E; Saint-Pe, M; Dupont, J; Potin, S; Cara, C; Lagage, P O; Leger, A; LeDuigou, J M; Shao, M; Goullioud, R

    2013-01-01

    NEAT is an astrometric mission proposed to ESA with the objectives of detecting Earth-like exoplanets in the habitable zone of nearby solar-type stars. NEAT requires the capability to measure stellar centroids at the precision of 5e-6 pixel. Current state-of-the-art methods for centroid estimation have reached a precision of about 2e-5 pixel at two times Nyquist sampling, this was shown at the JPL by the VESTA experiment. A metrology system was used to calibrate intra and inter pixel quantum efficiency variations in order to correct pixelation errors. The European part of the NEAT consortium is building a testbed in vacuum in order to achieve 5e-6 pixel precision for the centroid estimation. The goal is to provide a proof of concept for the precision requirement of the NEAT spacecraft. In this paper we present the metrology and the pseudo stellar sources sub-systems, we present a performance model and an error budget of the experiment and we report the present status of the demonstration. Finally we also pres...

  2. An Accurate and Efficient Gaussian Fit Centroiding Algorithm for Star Trackers

    Science.gov (United States)

    Delabie, Tjorven; Schutter, Joris De; Vandenbussche, Bart

    2015-06-01

    This paper presents a novel centroiding algorithm for star trackers. The proposed algorithm, which is referred to as the Gaussian Grid algorithm, fits an elliptical Gaussian function to the measured pixel data and derives explicit expressions to determine the centroids of the stars. In tests, the algorithm proved to yield accuracy comparable to that of the most accurate existing algorithms, while being significantly less computationally intensive. Hence, the Gaussian Grid algorithm can deliver high centroiding accuracy to spacecraft with limited computational power. Furthermore, a hybrid algorithm is proposed in which the Gaussian Grid algorithm yields an accurate initial estimate for a least squares fitting method, resulting in a reduced number of iterations and hence reduced computational cost. The low computational cost allows to improve performance by acquiring the attitude estimates at a higher rate or use more stars in the estimation algorithms. It is also a valuable contribution to the expanding field of small satellites, where it could enable low-cost platforms to have highly accurate attitude estimation.

  3. Metrology calibration and very high accuracy centroiding with the NEAT testbed

    CERN Document Server

    Crouzier, A; Preis, O; Henault, F; Kern, P; Martin, G; Feautrier, P; Stadler, E; Lafrasse, S; Delboulbe, A; Behar, E; Saint-Pe, M; Dupont, J; Potin, S; Cara, C; Donati, M; Doumayrou, E; Lagage, P O; Léger, A; LeDuigou, J M; Shao, M; Goullioud, R

    2014-01-01

    NEAT is an astrometric mission proposed to ESA with the objectives of detecting Earth-like exoplanets in the habitable zone of nearby solar-type stars. NEAT requires the capability to measure stellar centroids at the precision of 5e-6 pixel. Current state-of-the-art methods for centroid estimation have reached a precision of about 2e-5 pixel at two times Nyquist sampling, this was shown at the JPL by the VESTA experiment. A metrology system was used to calibrate intra and inter pixel quantum efficiency variations in order to correct pixelation errors. The European part of the NEAT consortium is building a testbed in vacuum in order to achieve 5e-6 pixel precision for the centroid estimation. The goal is to provide a proof of concept for the precision requirement of the NEAT spacecraft. The testbed consists of two main sub-systems. The first one produces pseudo stars: a blackbody source is fed into a large core fiber and lights-up a pinhole mask in the object plane, which is imaged by a mirror on the CCD. The ...

  4. Relation between medium fluid temperature and centroid subchannel temperatures of a nuclear fuel bundle mock-up

    International Nuclear Information System (INIS)

    The subchannel method used in nuclear fuel bundle thermal-hydraulic analysis lies in the statement that subchannel fluid temperatures are taken at mixed mean values. However, the development of mixing correlations and code assessment procedures are, sometimes in the literature, based upon the assumption of identity between lumped and local (subchannel centroid) temperature values. The present paper is concerned with the presentation of an approach for correlating lumped to centroid subchannel temperatures, based upon previously formulated models by the author, applied, applied to a nine heated tube bundle experimental data set. (Author)

  5. Relation between medium fluid temperature and centroid subchannel temperatures of a nuclear fuel bundle mock-up

    International Nuclear Information System (INIS)

    The subchannel method used in nuclear fuel bundle thermal-hydraulic analysis lies in the statement that subchannel fluid temperatures are taken at mixed mean values. However, the development of mixing correlations and code assessment procedures are, sometimes in the literature, based upon the assumption of identity between lumped and local (subchannel centroid) temperature values. The present paper is concerned with the presentation of an approach for correlating lumped to centroid subchannel temperatures, based upon previously formulated models by the author, applied to a nine heated tube bundle experimental data set. (Author)

  6. Finding and characterising WHIM structures using the luminosity density method

    CERN Document Server

    Nevalainen, J; Tempel, E; Branchini, E; Roncarelli, M; Giocoli, C; Heinamaki, P; Saar, E; Bonamente, M; Einasto, M; Finoguenov, A; Kaastra, J; Lindfors, E; Nurmi, P; Ueda, Y

    2014-01-01

    We have developed a new method to approach the missing baryons problem. We assume that the missing baryons reside in a form of Warm Hot Intergalactic Medium, i.e. the WHIM. Our method consists of (a) detecting the coherent large scale structure in the spatial distribution of galaxies that traces the Cosmic Web and that in hydrodynamical simulations is associated to the WHIM, (b) map its luminosity into a galaxy luminosity density field, (c) use numerical simulations to relate the luminosity density to the density of the WHIM, (d) apply this relation to real data to trace the WHIM using the observed galaxy luminosities in the Sloan Digital Sky Survey and 2dF redshift surveys. In our application we find evidence for the WHIM along the line of sight to the Sculptor Wall, at redshifts consistent with the recently reported X-ray absorption line detections. Our indirect WHIM detection technique complements the standard method based on the detection of characteristic X-ray absorption lines, showing that the galaxy l...

  7. Non-obtuse Remeshing with Centroidal Voronoi Tessellation

    KAUST Repository

    Yan, Dongming

    2015-12-03

    We present a novel remeshing algorithm that avoids triangles with small and triangles with large (obtuse) angles. Our solution is based on an extension to Centroidal Voronoi Tesselation (CVT). We augment the original CVT formulation by a penalty term that penalizes short Voronoi edges, while the CVT term helps to avoid small angles. Our results show significant improvements of the remeshing quality over the state of the art.

  8. Sistemas inteligentes para el análisis de fútbol: centroide ponderado

    OpenAIRE

    Clemente, Filipe Manuel; Santos Couceiro, Micael; Lourenço Martins, Fernando Manuel; Sousa Mendes, Rui; Figueiredo, António José

    2014-01-01

    Nuevos sistemas inteligentes se han desarrollado recientemente, con el fin de mejorar la calidad de análisis del partido. Estos sistemas basan su análisis en el comportamiento táctico de los equipos, sin embargo, todos los métodos innovadores necesitan algunos cam-bios para aumentar su potencial en las implicaciones prácticas. Por lo tanto, el objetivo principal de este trabajo es proponer una actualización del centroide y métrica del equipo, teniendo en cuenta a todos los jugadores del equip...

  9. Plasma Channel Diagnostic Based on Laser Centroid Oscillations

    Energy Technology Data Exchange (ETDEWEB)

    Gonsalves, A.J.; Nakamura, K.; Lin, C.; Osterhoff, J.; Shiraishi, S.; Schroeder, C.B.; Geddes, C.G.R.; Toth, Cs.; Esarey, E.; Leemans, W.P.

    2010-02-12

    A technique has been developed for measuring the properties of discharge-based plasma channels by monitoring the centroid location of a laser beam exiting the channel as a function of input alignment offset between the laser and the channel. Experiments were performed using low-intensity (< 1014 Wcm-2) laser pulses focused onto the entrance of a hydrogen-filled capillary discharge waveguide. Scanning the laser centroid position at the input of the channel and recording the exit position allows determination of the channel depth with an accuracy of a few percent, measurement of the transverse channel shape, and inference of the matched spot size. In addition, accurate alignment of the laser beam through the plasma channel is provided by minimizing laser centroid motion at the channel exit as the channel depth is scanned either by scanning the plasma density or the discharge timing. The improvement in alignment accuracy provided by this technique will be crucial for minimizing electron beam pointing errors in laser plasma accelerators.

  10. Improved envelope and centroid equations for high current beams

    International Nuclear Information System (INIS)

    The standard envelope equation for charged particle beams (e.g., Lee-Cooper) neglects self-field contributions from the beam rotation and the slope of the beam envelope. We have carried out an expansion that includes these effects to first order, resulting in a new equation for the edge radius. The change in beam kinetic energy due to space-charge depression as the beam radius varies is also included. For the centroid equation, we have included the 'self-steering' effect due to the curvature of the beam orbit. To leading order, there is a cancellation between the self-steering effect and the space-charge depression of the beam energy, so that a more accurate centroid equation is obtained by using the undepressed value of the energy (i.e., the total beam energy) to calculate the orbit. We have implemented the envelope and centroid equations in the Lamda code. The effect of the new terms will be illustrated with calculations for the DARHT accelerators at the Los Alamos National Laboratory

  11. Model Independent Analysis of Beam Centroid Dynamics in Accelerators

    International Nuclear Information System (INIS)

    Fundamental issues in Beam-Position-Monitor (BPM)-based beam dynamics observations are studied in this dissertation. The major topic is the Model-Independent Analysis (MIA) of beam centroid dynamics. Conventional beam dynamics analysis requires a certain machine model, which itself of ten needs to be refined by beam measurements. Instead of using any particular machine model, MIA relies on a statistical analysis of the vast amount of BPM data that often can be collected non-invasively during normal machine operation. There are two major parts in MIA. One is noise reduction and degrees-of-freedom analysis using a singular value decomposition of a BPM-data matrix, which constitutes a principal component analysis of BPM data. The other is a physical base decomposition of the BPM-data matrix based on the time structure of pulse-by-pulse beam and/or machine parameters. The combination of these two methods allows one to break the resolution limit set by individual BPMs and observe beam dynamics at more accurate levels. A physical base decomposition is particularly useful for understanding various beam dynamics issues. MIA improves observation and analysis of beam dynamics and thus leads to better understanding and control of beams in both linacs and rings. The statistical nature of MIA makes it potentially useful in other fields. Another important topic discussed in this dissertation is the measurement of a nonlinear Poincare section (one-turn) map in circular accelerators. The beam dynamics in a ring is intrinsically nonlinear. In fact, nonlinearities are a major factor that limits stability and influences the dynamics of halos. The Poincare section map plays a basic role in characterizing and analyzing such a periodic nonlinear system. Although many kinds of nonlinear beam dynamics experiments have been conducted, no direct measurement of a nonlinear map has been reported for a ring in normal operation mode. This dissertation analyzes various issues concerning map measurements and shows that it is possible to measure the Poincare section map (in terms of Taylor series) of a circular accelerator to a surprisingly high order and accuracy based on present BPM technology. MIA can overcome the inherent limit of BPM resolution. Nonlinear map measurements will advance understanding of the beam dynamics of a ring

  12. Bias in the centroid moment tensor for central Asian earthquakes: Evidence from regional surface wave data

    Energy Technology Data Exchange (ETDEWEB)

    Patton, H.J. [Geophysics Group, Earth and Environmental Sciences Division, Los Alamos National Laboratory, Los Alamos, New Mexico (United States)

    1998-11-01

    Surface waves recorded on the Chinese Digital Seismic Network (CDSN) station Urumqi (WMQ) are analyzed for 26 centroid moment tensor (CMT) earthquakes located within an epicentral distance of 1300 km. Applying a simple grid search method for source parameter retrieval, I obtain revised estimates of the focal depth, fault strike, and seismic moment (M{sub 0}) from amplitude spectra of Love and Rayleigh waves and compare these estimates with the CMT best double-couple solutions. The comparisons show that residuals are unbiased for focal depth and fault strike, where population spreads are {plus_minus}13 km and {plus_minus}17{degree}, respectively. On the other hand, M{sub 0} estimates are found to be biased, with CMT M{sub 0} larger than regional estimates by an average of 0.27{plus_minus}0.04 log units. The results for focal depth and strike are consistent with previous global and regional studies comparing independent estimates with CMT results. Recent full-waveform modeling studies for central Asian earthquakes support the findings of bias in M{sub 0} estimates. I suggest that causes for M{sub 0} bias may be related to great thicknesses of continental crust in Hindu Kush and Tien Shan regions and to data censoring practices at small magnitudes. M{sub 0}:m{sub b} scaling relationships for central Asian earthquakes show better agreement with western U.S. scaling when M{sub 0} estimates determined in this study are used. {copyright} 1998 American Geophysical Union

  13. Automated Centroid-based False Positive Detection of Kepler Planet Candidates

    Science.gov (United States)

    Mullally, Fergal; The Kepler Team

    2015-08-01

    We present a new technique to automate the identification of false positive planet candidates in Kepler data due to background eclipsing binaries. Background events from resolved or partially resolved sources can be identified by shifts in the distribution of light across CCD pixels during transit that produce shifts in the measured centroid of the stellar image. False positive signals are identified using this technique in all Kepler planet candidate catalogs, however the method was automated for this first time in the Q1-Q16 catalog of Mullally et al (2015). We describe the technique, its strengths and weaknesses.

  14. Fixed J spectral distributions in large shell model spaces. III. Fixed J quasiparticle centroids and widths

    International Nuclear Information System (INIS)

    A method is developed to exactly calculate the fixed J quasiparticle centroid energies and partial widths. Some results obtained in the even-mass lead isotopes with various interactions are analysed. Fixed J quasi-particle distributions are used to predict an upper limit for the deviations between the quasiparticle approximation and the shell model results for the low-energy levels. The influence of the states with a high quasiparticle number in the low-energy region is seen to strongly depend upon the interaction. The importance of the dimensionalities and the internal widths in explaining the admixtures is stressed

  15. Direct assessment of quantum nuclear effects on hydrogen bond strength by constrained-centroid ab initio path integral molecular dynamics

    Science.gov (United States)

    Walker, Brent; Michaelides, Angelos

    2010-11-01

    The impact of quantum nuclear effects on hydrogen (H-) bond strength has been inferred in earlier work from bond lengths obtained from path integral molecular dynamics (PIMD) simulations. To obtain a direct quantitative assessment of such effects, we use constrained-centroid PIMD simulations to calculate the free energy changes upon breaking the H-bonds in dimers of HF and water. Comparing ab initio simulations performed using PIMD and classical nucleus molecular dynamics (MD), we find smaller dissociation free energies with the PIMD method. Specifically, at 50 K, the H-bond in (HF)2 is about 30% weaker when quantum nuclear effects are included, while that in (H2O)2 is about 15% weaker. In a complementary set of simulations, we compare unconstrained PIMD and classical nucleus MD simulations to assess the influence of quantum nuclei on the structures of these systems. We find increased heavy atom distances, indicating weakening of the H-bond consistent with that observed by direct calculation of the free energies of dissociation.

  16. Class hierarchy method to find Change-Proneness

    OpenAIRE

    Malan V.Gaikwad; Aparna S.Nakil,; Akhil Khare,

    2011-01-01

    Finding Proneness of software is necessary to identify fault prone and change prone classes at earlier stages of development, so that those classes can be given special attention. Also to improves the quality and reliability of the software. For corrective and adaptive maintenance we require to make changes during the software evolution.As such changes cluster around number of key components in software, it is important to analyze the frequency of changes in individual classes and also to ide...

  17. Methods to find out the expression of activated genes

    Directory of Open Access Journals (Sweden)

    Cekan Sten Z

    2004-09-01

    Full Text Available Abstract This review deals with the methods of identifying genes that have been activated by inner or outer impulses. The activation and subsequent expression of a gene can be detected by its transcription into a corresponding messenger ribonucleic acid (mRNA. Principles of the methods for identification of individual activated genes, as well as groups of activated genes are described, the former methods being mostly based on subtractive hybridization and serial analysis of gene expression (SAGE, the latter on microarrays. Examples of gene activation by the hormone 17beta-estradiol (E2 are given.

  18. Class hierarchy method to find Change-Proneness

    Directory of Open Access Journals (Sweden)

    Malan V.Gaikwad

    2011-01-01

    Full Text Available Finding Proneness of software is necessary to identify fault prone and change prone classes at earlier stages of development, so that those classes can be given special attention. Also to improves the quality and reliability of the software. For corrective and adaptive maintenance we require to make changes during the software evolution.As such changes cluster around number of key components in software, it is important to analyze the frequency of changes in individual classes and also to identify and show related changes in multiple classes. Early detection of fault prone and change prone classes can enables the developers and experts to spend their valuable time and resources on these areas of software. Prediction of change-prone and fault prone classes of a software is an active topic in the area of software engineering. Such prediction can be used to predict changes to different classes of a system from one release of software to the next release. Identifying the change-prone and fault prone classes in advance can helps to focus attention on these classes.In this paper we are focusing on finding dependency of software that can be chieved by estimating the proneness of Object Oriented Software. Two main types of proneness are associated with OO software. Fault Proneness and Change Proneness.

  19. Visualising Pipeline Sensor Datasets with Modified Incremental Orthogonal Centroid Algorithm

    Directory of Open Access Journals (Sweden)

    Folorunso Olufemi Ayinde

    2011-09-01

    Full Text Available Each year, millions of people suffer from after-effects of pipeline leakages, spills, and eruptions. Leakages Detection Systems (LDS are often used to understand and analyse these phenomena but unfortunately could not offer complete solution to reducing the scale of the problem. One recent approach was to collect datasets from these pipeline sensors and analyse offline, the approach yielded questionable results due to vast nature of the datasets. These datasets together with the necessity for powerful exploration tools made most pipelines operating companies "data rich but information poor". Researchers have therefore identified problem of dimensional reduction for pipeline sensor datasets as a major research issue. Hence, systematic gap filling data mining development approaches are required to transform data "tombs" into "golden nuggets" of knowledge. This paper proposes an algorithm for this purpose based on the Incremental Orthogonal Centroid (IOC. Search time for specific data patterns may be enhanced using this algorithm.

  20. Novas abordagens da avaliação do comportamento tático no futebol: análise do centroid e índice de dispersão / Towards a new evaluation of the football' tactical behaviour: analysis of the centroid and stretch index

    Scientific Electronic Library Online (English)

    Rui Manuel, Mendes; Filipe Manuel, Clemente; Micael Santos, Couceiro; Fernando Manuel Lourenço, Martins.

    2013-12-01

    Full Text Available A tendência evolutiva do futebol determina as necessidades de produzir ferramentas inovadoras que aumentem substancialmente a eficiência da análise de jogo. Considerando os métodos tradicionais notacionais como limitados para a interpretação dos processos de jogo, a investigação carece de novos méto [...] dos nos quais prevaleça a análise do processo. Dessa forma, o presente trabalho propõe-se a analisar novas métricas quantitativas e automáticas de avaliação tática no futebol, nomeadamente o centroid de equipe e o índice de dispersão. Abstract in english The evolutionary tendency of the football game determines the conception of the new tools that increase the efficiency of the match analysis. The traditional notational analysis, actually, are limited to understand the true dynamic of the football match, thus the investigation lacks by new methods t [...] o understand the process and not just the product. Therefore, this work aims analyze new automatically tactical metrics, specifically the centroid and the stretch index method.

  1. Centroid depth and mechanism of trench-outer rise earthquakes

    Science.gov (United States)

    Lefeldt, Marten; Grevemeyer, Ingo

    2008-01-01

    Trench-outer rise earthquakes occur by reactivation or creation of normal faults caused as the oceanic lithosphere approaches a subduction zone and bends into the deep-sea trench. These faults may cut deep enough into the mantle to allow sea water to penetrate into the lithosphere, causing serpentinization. The amount of water carried into the mantle is linked to the maximum depth that the tensional faults cut into the lithosphere, which in turn is directly linked to the maximum focal depths of outer rise normal faulting earthquakes. We analysed teleseismic P and S waves of seven earthquakes from the trench-outer rise offshore of Central America using teleseismic waveform inversion of broad-band data. For the computation of Green's functions for waveform inversion, probabilistic earthquake locations were calculated. To study the rupture process, earthquake centroid depths and focal mechanisms for a sequence of subevents were calculated. Both, hypocentral depths from the relocation process and the estimated centroid depths from the waveform inversion show that all events occur at shallow depths (<30 km). Furthermore, the locations of the subevents relative to each other suggest that fault planes for Mw ~ 6 are in the order of 50 km in length and only 5-10 km in width. Rupture generally propagates downdip and the focal mechanisms change for most events from normal faulting to strike-slip or oblique thrusting with time. The depth at which this mechanism change is observed may represent the depth of the nodal plane between tensional and compressional regions in the incoming plate.

  2. Finding Methods for Innovative Packaging Development: The Card Approach

    OpenAIRE

    Magnusson, Amanda; Olander, Malin; Olsson, Annika

    2013-01-01

    Innovation strategies are crucial for corporate success and should be a top priority for packaging companies. However, to improve the innovativeness of packaging manufacturers, there is a need to increase the integration of product and packaging development and collaboration within the supply chain. New methods for innovative packaging development are needed. Packaging plays a valuable role in the marketing and distribution of products, and can thus add great value for actors in the supply...

  3. Functional Imaging of Autonomic Regulation: Methods and Key Findings

    Science.gov (United States)

    Macey, Paul M.; Ogren, Jennifer A.; Kumar, Rajesh; Harper, Ronald M.

    2016-01-01

    Central nervous system processing of autonomic function involves a network of regions throughout the brain which can be visualized and measured with neuroimaging techniques, notably functional magnetic resonance imaging (fMRI). The development of fMRI procedures has both confirmed and extended earlier findings from animal models, and human stroke and lesion studies. Assessments with fMRI can elucidate interactions between different central sites in regulating normal autonomic patterning, and demonstrate how disturbed systems can interact to produce aberrant regulation during autonomic challenges. Understanding autonomic dysfunction in various illnesses reveals mechanisms that potentially lead to interventions in the impairments. The objectives here are to: (1) describe the fMRI neuroimaging methodology for assessment of autonomic neural control, (2) outline the widespread, lateralized distribution of function in autonomic sites in the normal brain which includes structures from the neocortex through the medulla and cerebellum, (3) illustrate the importance of the time course of neural changes when coordinating responses, and how those patterns are impacted in conditions of sleep-disordered breathing, and (4) highlight opportunities for future research studies with emerging methodologies. Methodological considerations specific to autonomic testing include timing of challenges relative to the underlying fMRI signal, spatial resolution sufficient to identify autonomic brainstem nuclei, blood pressure, and blood oxygenation influences on the fMRI signal, and the sustained timing, often measured in minutes of challenge periods and recovery. Key findings include the lateralized nature of autonomic organization, which is reminiscent of asymmetric motor, sensory, and language pathways. Testing brain function during autonomic challenges demonstrate closely-integrated timing of responses in connected brain areas during autonomic challenges, and the involvement with brain regions mediating postural and motoric actions, including respiration, and cardiac output. The study of pathological processes associated with autonomic disruption shows susceptibilities of different brain structures to altered timing of neural function, notably in sleep disordered breathing, such as obstructive sleep apnea and congenital central hypoventilation syndrome. The cerebellum, in particular, serves coordination roles for vestibular stimuli and blood pressure changes, and shows both injury and substantially altered timing of responses to pressor challenges in sleep-disordered breathing conditions. The insights into central autonomic processing provided by neuroimaging have assisted understanding of such regulation, and may lead to new treatment options for conditions with disrupted autonomic function.

  4. A Fuzzy Centroids Clustering Algorithm with Between-cluster Information for Categorical Data

    OpenAIRE

    Wang Li-Na; Liu Qian; Zhou Yuan

    2013-01-01

    In this study, a new fuzzy centroids clustering for categorical data is presented. The objective function of the fuzzy k-modes algorithm is modified by adding the between-cluster information so as to simultaneously minimize the within-cluster dispersion and enhance the between-cluster separation. Due to the misclassification by using the hard centroids, a fuzzy centroids clustering with the between-cluster information for categorical data is provided. Furthermore, the dissimilarity measure be...

  5. Findings from analysing and quantifying human error using current methods

    International Nuclear Information System (INIS)

    In human reliability analysis (HRA), the scarcity of data means that, at best, judgement must be applied to transfer to the domain of the analysis what data are available for similar tasks. In particular for the quantification of tasks involving decisions, the analyst has to choose among quantification approaches that all depend to a significant degree on expert judgement. The use of expert judgement can be made more reliable by eliciting relative judgements rather than absolute judgements. These approaches, which are based on multiple criterion decision theory, focus on ranking the tasks to be analysed by difficulty. While these approaches remedy at least partially the poor performance of experts in the estimation of probabilities, they nevertheless require the calibration of the relative scale on which the actions are ranked in order to obtain the probabilities of interest. This paper presents some results from a comparison of some current HRA methods performed in the frame of a study of SLIM calibration options. The HRA quantification methods THERP, HEART, and INTENT were applied to derive calibration human error probabilities for two groups of operator actions. (author)

  6. User Manual and Supporting Information for Library of Codes for Centroidal Voronoi Point Placement and Associated Zeroth, First, and Second Moment Determination; TOPICAL

    International Nuclear Information System (INIS)

    The theory, numerical algorithm, and user documentation are provided for a new ''Centroidal Voronoi Tessellation (CVT)'' method of filling a region of space (2D or 3D) with particles at any desired particle density. ''Clumping'' is entirely avoided and the boundary is optimally resolved. This particle placement capability is needed for any so-called ''mesh-free'' method in which physical fields are discretized via arbitrary-connectivity discrete points. CVT exploits efficient statistical methods to avoid expensive generation of Voronoi diagrams. Nevertheless, if a CVT particle's Voronoi cell were to be explicitly computed, then it would have a centroid that coincides with the particle itself and a minimized rotational moment. The CVT code provides each particle's volume and centroid, and also the rotational moment matrix needed to approximate a particle by an ellipsoid (instead of a simple sphere). DIATOM region specification is supported

  7. Assessing the uncertainties on seismic source parameters: Towards realistic error estimates for centroid-moment-tensor determinations

    OpenAIRE

    Valentine, A.P.; Trampert, J.

    2012-01-01

    The centroid-moment-tensor (CMT) algorithm provides a straightforward, rapid method for the determination of seismic source parameters from waveform data. As such, it has found widespread application, and catalogues of CMT solutions – particularly the catalogue maintained by the Global CMT Project – are routinely used by geoscientists. However, there have been few attempts to quantify the uncertainties associated with any given CMT determination: whilst catalogues typically quote ...

  8. Gravimetric method to find internal surface of macroporous silicon membranes

    Energy Technology Data Exchange (ETDEWEB)

    Nechitailov, A.A.; Astrova, E.V.; Kukushkina, Yu.A. [Ioffe Physico-Technical Institute, Russian Academy of Sciences, St. Petersburg 194021 (Russian Federation)

    2007-07-01

    A simple method to evaluate the internal surface area, porosity, pore diameter and pore density of macroporous silicon membranes has been proposed and tested. The porosity p is obtained from the mass loss under anodizing, and the surface area per unit volume S{sub v} is determined from the mass of SiO{sub 2} formed on the pore surface as a result of thermal oxidation. The average pore diameter d and pore density N can be easily calculated from the obtained S{sub v} and p. Experimental verification of d and N was performed by means of SEM and optical microscope images; S{sub v} was checked by BET technique. Surface area and porosity on the resistivity of initial n-Si in the range {rho}=3-25 Ohm.cm have been studied for the samples with regular and self-organized macropore ''lattices''. The obtained values are within the limits p=27-50%, S{sub v}=2800-6000 cm{sup 2}/cm{sup 3}, d=1.9-6.5 {mu}m, N=1.4-10 x 10{sup 6} cm{sup -2}, and in a good agreement with the data of microscopic characterization. (copyright 2007 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  9. Onychomycosis: Clinical findings, etiological agents and evaluation of laboratory methods

    Directory of Open Access Journals (Sweden)

    Dubljanin Eleonora

    2014-01-01

    Full Text Available The aim of this study was to identify the etiological agents in patients with suspected onychomycosis, and to carry out comparative testing of individual or combinations of tests: direct microscopy with KOH and Blankophor (BP, culturing on Sabouraud’s dextrose agar (SDA, diluted Sabouraud’s dextrose agar (D-SDA and dermatophyte test medium (DTM. From 70 nail samples (65 toenails, 5 fingernails, 46 (60.5% had at least one of five positive tests. Isolation was possible in 41, while in 5 samples the presence of fungi was observed by KOH and/or BP. Dermatophytes were most frequently isolated (80.5% where Trichophyton rubrum was predominant. Candida spp. was isolated in 9.8%, Aspergillus spp. 4.9%, Alternaria spp. 2.4% and Fusarium spp. 2.4%. Application of BP as an individual test was the most sensitive method. The combination of BP with DTM or D-SDA provides the best sensitivity and allows the identification of fungi to the species/genus level.

  10. Planning Pharmacies: An Operational Method to Find the Best Location

    Directory of Open Access Journals (Sweden)

    Simona Tondelli

    2014-05-01

    Full Text Available The theme of the spatial distribution of the pharmacies on the territory is closely connected to urban planning and to services supply. In Italy, the regulatory change that took place in 2012, triggered partly by the need to adhere more to a constantly changing economic system, has led to a revision of the existing situation, consisting both on the method to quantify the pharmacies distribution and on the efficiency of the service. If Law 27/2012 has effectively allowed municipalities to increase the number of pharmacies that they can settle on the municipal territory, it has also started a process of rethinking the logic of pharmacies location and of their catchment areas. In this framework, the present paper aims to discuss the merits of a regulatory evolutions that sparked the process of liberalization of locations, integrating the law guidelines and goals with an operating logic process, usable and useful to translate goals into planning actions in a continuous dialogue between law and territory, constraints and opportunities, equity and accessibility of the care services. Following this logic operations, we have investigated the urban context of Castelfranco Emilia, assuming the location of new offices on the basis of pharmaceutical analyzes.

  11. Total Magnification and Magnification Centroid Due to Strongly Naked Singularity Lensing

    CERN Document Server

    DeAndrea, Justin

    2015-01-01

    A strongly naked singularity (SNS) was modelled at the center of the Galaxy. This specific type of naked singularity was characterized in 2008 by Virbhadra and Keeton. The lens is described using the Janis-Newman-Winicour metric, which has an ordinary mass and massless scalar charge parameters. Gravitational lensing by the SNS gives rise to 4 images: 2 images on the same side as the source and 2 images on the opposite side of the source from the optic axis. We compute magnification centroid, magnification centroid shift, and total absolute magnification for many values of the angular source position. The nature of the curve for all three results are qualitatively similar to Schwarzschild black hole lenses, but quantitatively different. Magnification centroid increases as angular source position increases. As angular source position increases, magnification centroid shift increases to a maximum value, and then begins to decrease. As angular source position becomes large, magnification centroid shift will appro...

  12. A Fuzzy Centroids Clustering Algorithm with Between-cluster Information for Categorical Data

    Directory of Open Access Journals (Sweden)

    Wang Li-Na

    2013-01-01

    Full Text Available In this study, a new fuzzy centroids clustering for categorical data is presented. The objective function of the fuzzy k-modes algorithm is modified by adding the between-cluster information so as to simultaneously minimize the within-cluster dispersion and enhance the between-cluster separation. Due to the misclassification by using the hard centroids, a fuzzy centroids clustering with the between-cluster information for categorical data is provided. Furthermore, the dissimilarity measure between an object and the centroid at the feature level is given as 1 minus the frequency of the feature value of the object. On several real data sets from UCI, the proposed algorithm is effective and the performance of the novel algorithm outperforms the one with hard-type centroids.

  13. Franck–Condon factors and r-centroids for the diatomic fluorides of germanium and silicon

    Directory of Open Access Journals (Sweden)

    S. KANAGAPRABHA

    2008-05-01

    Full Text Available A suitable potential energy function was found by analysing the potential functions proposed by Morse, Mohammad and Rafi et al. for the A2?+–X2?3/2 and B2?+–X2?3/2 band systems of GeF and the 1?–1? band system of SiF. It was found that the potential proposed by Rafi et al. is in close agreement with the Rydberg–Klein–Rees (R–K–R potential. Using this potential, the wave functions were evaluated by the Wentzel–Kramer–Brillouin (W–K–B method. The Franck–Condon factors and r-centroids were computed by a numerical integration technique. The results are compared with available theoretical values. The intensities of the various bands were investigated.

  14. Grand-Canonical Adaptive Resolution Centroid Molecular Dynamics: Implementation and Application

    CERN Document Server

    Agarwal, Animesh

    2016-01-01

    We have implemented the Centroid Molecular Dynamics scheme (CMD) into the Grand Canonical-like version of the Adaptive Resolution Simulation Molecular Dynamics (GC-AdResS) method. We have tested the implementation on two different systems, liquid parahydrogen at extreme thermodynamic conditions and liquid water at ambient conditions; the reproduction of structural as well as dynamical results of reference systems are highly satisfactory. The capability of performing GC-AdResS CMD simulations allows for the treatment of a system characterized by some quantum features and open boundaries. This latter characteristic not only is of computational convenience, allowing for equivalent results of much larger and computationally more expensive systems, but also suggests a tool of analysis so far not explored, that is the unambiguous identification of the essential (quantum) degrees of freedom required for a given property.

  15. Variation of acoustic mode centroid frequencies over the solar cycle

    Science.gov (United States)

    Chaplin, W. J.; Appourchaux, T.; Elsworth, Y.; Isaak, G. R.; New, R.

    Together with a brief historical overview, we use high-quality helioseismic data collected by three different observational programmes during the declining phase of activity cycle 22, and a substantial portion of the rising phase of the current cycle (23), to study the phenomenological nature of the cycle-induced (centroid) eigenfrequencies. Our analyses (for 1600 ? ? ? 4000 ?Hz) make use of observations made by the ground-based GONG over the angular degree range 4 ? l ? 150; the ground-based BiSON over 0 ? l ? 2; and the VIRGO/LOI instrument on board the ESA/NASA SOHO satellite over 0 ? l ? 8. We show that GONG shifts averaged over different ranges in l, together with the BiSON and LOI data averaged over their full quoted ranges, all scale at a given frequency with the normalized mode inertia ratio Qnl (Christensen-Dalsgaard & Berthomieu 1991). This is to be expected if the time-dependent perturbation affecting the modes is confined in the surface layers; the excellent agreement also reflects favourably on the external consistency of the different observations. We have also analyzed the frequency dependence of the shifts by fitting a power-law of the form ?? nl ? (? nl/ Enl to the data (where the Enl are the mode inertias, and ? is the power-law index to be extracted). Previous studies have suggested that a relation with ? = 0 provides an adequate description of the shifts up to ? ? 3500 ?Hz. However, here we show that while nevertheless describing the shifts well up to ˜ 2500 ?Hz, the linear scaling breaks down conspicuously at higher frequencies. Above this threshold, the shifts follow a power-law dependence with ? ˜ 2.

  16. Outlier Finding from Clusters using Categorical Data

    Directory of Open Access Journals (Sweden)

    Anamika Malaiya

    2012-12-01

    Full Text Available A New Categorical Data algorithm which combines a systematic method for finding initial centroids and an efficient way for assigning data points to clusters. This method ensures the entire process generate cluster without sacrificing the accuracy. It always generate good cluster by reducing the mean square error. Our clustering algorithm serves as a good benchmark to monitor the progression of student’s performance in institute. It also enhances the decision making by academic planners to monitor the student’s performance semester by semester by improving on the future academic results in the subsequence academic session.

  17. Multiscale Superpixels and Supervoxels Based on Hierarchical Edge-Weighted Centroidal Voronoi Tessellation.

    Science.gov (United States)

    Zhou, Youjie; Ju, Lili; Wang, Song

    2015-11-01

    Superpixels and supervoxels play an important role in many computer vision applications, such as image segmentation, object recognition, and video analysis. In this paper, we propose a new hierarchical edge-weighted centroidal Voronoi tessellation (HEWCVT) method for generating superpixels/supervoxels in multiple scales. In this method, we model the problem as a multilevel clustering process: superpixels/supervoxels in one level are clustered to obtain larger size superpixels/supervoxels in the next level. In the finest scale, the initial clustering is directly conducted on pixels/voxels. The clustering energy involves both color similarities and boundary smoothness of superpixels/supervoxels. The resulting superpixels/supervoxels can be easily represented by a hierarchical tree which describes the nesting relation of superpixels/supervoxels across different scales. We first investigate the performance of obtained superpixels/supervoxels under different parameter settings, then we evaluate and compare the proposed method with several state-of-the-art superpixel/supervoxel methods on standard image and video data sets. Both quantitative and qualitative results show that the proposed HEWCVT method achieves superior or comparable performances with other methods. PMID:26111396

  18. Methods for Synthesizing Findings on Moderation Effects Across Multiple Randomized Trials

    OpenAIRE

    Brown, C Hendricks; Sloboda, Zili; FAGGIANO, Fabrizio; Teasdale, Brent; Keller, Ferdinand; Burkhart, Gregor; Vigna-Taglianti, Federica; Howe, George; Masyn, Katherine; Wang, Wei; Muthén, Bengt; Stephens, Peggy; Grey, Scott; Perrino, Tatiana

    2013-01-01

    This paper presents new methods for synthesizing results from subgroup and moderation analyses across different randomized trials. We demonstrate that such a synthesis generally results in additional power to detect significant moderation findings above what one would find in a single trial. Three general methods for conducting synthesis analyses are discussed, with two methods, integrative data analysis, and parallel analyses, sharing a large advantage over traditional methods available in m...

  19. An Efficient Range Partitioning Method for Finding Frequent Patterns from Huge Database

    Directory of Open Access Journals (Sweden)

    Ms. Ruchita Gupta

    2012-06-01

    Full Text Available Data mining is finding increasing acceptance inscience and business areas that need to analyzelarge amounts of data to discover trends that theycould not otherwise find. Different applications mayrequire different data mining techniques. The kindsof knowledge that could be discovered from adatabase are categorized into association rulesmining, sequential patterns mining, classification,and clustering. In this paper we present an efficientrange partitioning method for finding frequentpattern from huge database. It is based on key baseddivision for finding the local frequent pattern(LFP. After finding the partition frequent patternfrom the subdivided local database, we then find theglobal frequent pattern from the local database andperform the pruning from the whole database.

  20. Statistical Properties of Line Centroid Velocity Increments in the rho Ophiuchi Cloud

    OpenAIRE

    Lis, D. C.; Keene, Jocelyn; Li, Y.; ~Phillips, T. G.; Pety, J.

    1998-01-01

    We present a comparison of histograms of CO (2-1) line centroid velocity increments in the rho Ophiuchi molecular cloud with those computed for spectra synthesized from a three-dimensional, compressible, but non-star-forming and nongravitating, hydrodynamic simulation. Histograms of centroid velocity increments in the rho Oph cloud clearly show non-Gaussian wings similar to those found in histograms of velocity increments and derivatives in experimental studies of laboratory and atmospheric f...

  1. Centroid shift analysis of microlens array detector in interference imaging system

    Science.gov (United States)

    Zhao, Zhu; Hui, Mei; Liu, Ming; Dong, Liquan; Liu, Xiaohua; Zhao, Yuejin

    2015-11-01

    Most CCD imaging detectors integrated microlens arrays (MLAs) to increase fill factor and sensitivity. However, they also introduce spot calibration issues with the inconsistency of spot geometry center and intensity distribution center. We setup theoretical and experimental models to research the problem of centroid shifting. According to the Seidel and Zernike coefficients of the optical model, we analyze main aberrations of microlens. In "Chief Ray" and "Centroid" reference frames, centroid shift numerical value is calculated with Geometric Ensquared Energy (GEE). Based on pentaprism test for 8.4 m mirror segment, we conduct spot imaging experiment in interference system. Spots images are obtained, and two-dimensional centroid algorithm processing is performed on them to get the analog experiment values of centroid movements. The results show that the MLA placed in KAI-16000 imaging detector causes the spot centroid to move. When there is a 14° (or -14°) angle of incident ray, the shifting values are about 1.46 ?m in simulation and 2.18 ?m in experiment. Our research makes a contribution to the compensation of calibrated error in metrology technology. We also prove that a significant portion of the shift comes from the low order aberration of microlens.

  2. Quantitative measurement of Parkinsonian gait from walking in monocular image sequences using a centroid tracking algorithm.

    Science.gov (United States)

    Lin, Sheng-Huang; Chen, Shih-Wei; Lo, Yu-Chun; Lai, Hsin-Yi; Yang, Chich-Haung; Chen, Shin-Yuan; Chang, Yuan-Jen; Chen, Chin-Hsing; Huang, Wen-Tzeng; Jaw, Fu-Shan; Chen, You-Yin; Tsang, Siny; Liao, Lun-De

    2016-03-01

    Parkinson's disease (PD) is a neurodegenerative disease of the central nervous system that results from the degeneration of dopaminergic neurons in the substantia nigra. Abnormal gait begins in the early stage and becomes severe as the disease progresses; therefore, the assessment of gait becomes an important issue in evaluating the progression of PD and the effectiveness of treatment. To provide a clinically useful gait assessment in environments with budget and space limitations, such as a small clinic or home, we propose and develop a portable method utilizing the monocular image sequences of walking to track and analyze a Parkinsonian gait pattern. In addition, a centroid tracking algorithm is developed and used here to enhance the method of quantifying kinematic gait parameters of PD in different states. Twelve healthy subjects and twelve mild patients with PD participate in this study. This method requires one digital video camera and subjects with two joint markers attached on the fibula head and the lateral malleolus of the leg. All subjects walk with a natural pace in front of a video camera during the trials. Results of our study demonstrate the stride length and walking velocity significantly decrease in PD without drug compared to PD with drug in both proposed method and simultaneous gait assessment performed by GAITRite(®) system. In gait initiation, step length and swing velocity also decrease in PD without drug compared to both PD with drug and controls. Our results showed high correlation in gait parameters between the two methods and prove the reliability of the proposed method. With the proposed method, quantitative measurement and analysis of Parkinsonian gait could be inexpensive to implement, portable within a small clinic or home, easy to administer, and simple to interpret. Although this study is assessed Parkinsonian gait, the proposed method has the potential to help clinicians and researchers assess the gait of patients with other neuromuscular diseases, such as traumatic brain injury and stroke patients. PMID:26109520

  3. The impact of the in-orbit background and the X-ray source intensity on the centroiding accuracy of the Swift X-ray telescope

    International Nuclear Information System (INIS)

    The optical components of the Swift Gamma Ray Burst Explorer X-ray Telescope (XRT), consisting of the JET-X spare flight mirror and a charge coupled device of the type used in the EPIC program, were used in a re-calibration study carried out at the Panter facility, which is part of the Max Plank Institute for Extraterrestrial Physics. The objective of this study was to check the focal length and the off axis performance of the mirrors and to show that the half energy width (HEW) of the on-axis point spread function (PSF) was of the order of 16 arcsec at 1.5 keV (Nucl. Instr. and Meth. A 488 (2002) 543; SPIE 4140 (2000) 64) and that a centroiding accuracy better that 1 arcsec could be achieved within the 4 arcmin sampling area designated by the Burst Alert Telescope (Nucl. Instr. and Meth. A 488 (2002) 543). The centroiding accuracy of the Swift XRT's optical components was tested as a function of distance from the focus and off axis position of the PSF (Nucl. Instr. and Meth. A 488 (2002) 543). The presence of background events in the image frame introduced errors in the centroiding process, making the choice of centroiding algorithm important (Nucl. Instr. and Meth. A 488 (2002) 543). Since the objective of Swift is to rapidly investigate the X-ray afterglows of Gamma Ray Bursts the possibility of detecting a bright source with intensity greater than 25 Crab could not be excluded and therefore the impact of a saturated PSF core on the centroiding accuracy was investigated by experimental methods

  4. Finding-equal regression method and its application in predication of U resources

    International Nuclear Information System (INIS)

    The commonly adopted deposit model method in mineral resources predication has two main part: one is model data that show up geological mineralization law for deposit, the other is statistics predication method that accords with characters of the data namely pretty regression method. This kind of regression method may be called finding-equal regression, which is made of the linear regression and distribution finding-equal method. Because distribution finding-equal method is a data pretreatment which accords with advanced mathematical precondition for the linear regression namely equal distribution theory, and this kind of data pretreatment is possible of realization. Therefore finding-equal regression not only can overcome nonlinear limitations, that are commonly occurred in traditional linear regression or other regression and always have no solution, but also can distinguish outliers and eliminate its weak influence, which would usually appeared when Robust regression possesses outlier in independent variables. Thus this newly finding-equal regression stands the best status in all kind of regression methods. Finally, two good examples of U resource quantitative predication are provided

  5. An Efficient Range Partitioning Method for Finding Frequent Patterns from Huge Database

    Directory of Open Access Journals (Sweden)

    Ruchita Gupta

    2012-06-01

    Full Text Available Data mining is finding increasing acceptance in science and business areas that need to analyze large amounts of data to discover trends that they could not otherwise find. Different applications may require different data mining techniques. The kinds of knowledge that could be discovered from a database are categorized into association rules mining, sequential patterns mining, classification, and clustering. In this paper we present an efficient range partitioning method for finding frequent pattern from huge database. It is based on key based division for finding the local frequent pattern (LFP. After finding the partition frequent pattern from the subdivided local database, we then find the global frequent pattern from the local database and perform the pruning from the whole database.

  6. Efficient Search and Fit Methods to Find Nerve Stimulation Parameters for Multi-Contact Electrodes

    Science.gov (United States)

    Freeberg, Max J; Schiefer, Matthew A.; Triolo, Ronald J.

    2015-01-01

    This paper describes a method to efficiently sample EMG recruitment space over a wide range of pulse amplitude (PA) and pulse width (PW). A gradient based search method is developed to find high information areas of a recruitment surface. This search method is first examined in the context of simulated EMG recruitment data and its ability to sample and subsequently fit Gompertz-Function-inspired surfaces to it. The search method is then used to determine parameters when stimulating through an 8 contact flat interface nerve electrode (FINE). The recorded EMG recruitment data are then used to validate the Gompertz surface fitting method as well as the search method. PMID:22256009

  7. Quantum Imaging beyond the Diffraction Limit by Centroid Measurements

    CERN Document Server

    Tsang, Mankei

    2009-01-01

    I propose a quantum imaging method that can beat the Rayleigh-Abbe diffraction limit and achieve de Broglie resolution without requiring a multiphoton absorber as the detector. Using the same non-classical states of light as those for quantum lithography, the proposed method requires only intensity measurements, followed by image post-processing, to produce the same complex image patterns as those in quantum lithography. The method is expected to be experimentally realizable using current technology.

  8. Parallel shooting methods for finding steady state solutions to engine simulation models

    DEFF Research Database (Denmark)

    Andersen, Stig Kildegård; Thomsen, Per Grove; Carlsen, Henrik

    2007-01-01

    Parallel single- and multiple shooting methods were tested for finding periodic steady state solutions to a Stirling engine model. The model was used to illustrate features of the methods and possibilities for optimisations. Performance was measured using simulation of an experimental data set as...

  9. A new method to find full complex roots of a complex dispersion equation for light propagation

    CERN Document Server

    Wan, Li

    2011-01-01

    A new numerical method is presented to find full complex roots of a complex dispersion equation. For the application of the solution, the complex dispersion equation of a cylindrical metallic nanowire is investigated. By using this method, locus of Brewster angle, complex dispersion curves of Surface Plasmon Polaritons (SPPs) and complex bulk modes can be obtained in once calculation. Approximate analytical solution to the complex dispersion equation has also been derived to verify our method.

  10. Dressing transformation method for finding soliton solutions of the sinh-Gordon equation

    International Nuclear Information System (INIS)

    In this paper, the establishment of the dressing transformations in the sinh-Gordon model is reconsidered. By carefully analysing the infinitesimal structures of dressing transformations, we improve the algebraic method for solving the dressing problem in the system and then lay the dressing transformation method on a firm basis. The modified dressing transformation method, which no longer contains any deductive jumps, turns out to become a powerful Hamiltonian approach to finding N-soliton solutions (N?1) of the integrable systems. (author)

  11. Experimental determination of Philodendron melinonii and Arabidopsis thaliana tissue microstructure and geometric modeling via finite-edge centroidal Voronoi tessellation

    Science.gov (United States)

    Faisal, Tanvir R.; Hristozov, Nicolay; Rey, Alejandro D.; Western, Tamara L.; Pasini, Damiano

    2012-09-01

    Plant petioles and stems are hierarchical cellular structures, displaying structural features defined at multiple length scales. One or more of the intermediate hierarchical levels consists of tissues, in which the cellular distribution is quasirandom. The current work focuses on the realistic modeling of plant tissue microstructures. The finite-edge centroidal Voronoi tessellation (FECVT) is here introduced to overcome the drawbacks of the semi-infinite edges of a typical Voronoi model. FECVT can generate a realistic model of a tissue microstructure, which might have finite edges at its border, be defined by a boundary contour of any shape, and include complex heterogeneity and cellular gradients. The centroid-based Voronoi tessellation is applied to model the microstructure of the Philodendron melinonii petiole and the Arabidopsis thaliana stem, which both display intense cellular gradients. FECVT coupled with a digital image processing algorithm is implemented to capture the nonperiodic microstructures of plant tissues. The results obtained via this method satisfactorily obey the geometric, statistical, and topological laws of naturally evolved cellular solids. The predicted models are also validated by experimental data.

  12. Expansion of Sliding Window Method for Finding Shorter Addition/Subtraction-Chains

    OpenAIRE

    Younho Lee; Heeyoul Kim; Seong-Min Hong; Hyunsoo Yoon

    2006-01-01

    Finding a shorter addition/subtraction-chain for an integer is an important problem for many cryptographic systems based on number theory. Especially, execution time of multiplication on an elliptic curve cryptosystem is directly proportional to the length of the addition/subtraction-chain. In this paper, we propose an algorithm to find an addition/subtraction-chain. The proposed algorithm is based on the small-window method, and reduces the number of windows by using subtractions. We show th...

  13. Expansion of Sliding Window Method for Finding Shorter Addition/Subtraction-Chains

    Directory of Open Access Journals (Sweden)

    Younho Lee

    2006-01-01

    Full Text Available Finding a shorter addition/subtraction-chain for an integer is an important problem for many cryptographic systems based on number theory. Especially, execution time of multiplication on an elliptic curve cryptosystem is directly proportional to the length of the addition/subtraction-chain. In this paper, we propose an algorithm to find an addition/subtraction-chain. The proposed algorithm is based on the small-window method, and reduces the number of windows by using subtractions. We show the proposed algorithm finds the shorter addition/subtraction-chain than what can be found by any other previous algorithm.

  14. A Fast Randomized Method to Find Homotopy Classes for Socially-Aware Navigation

    OpenAIRE

    Palmieri, Luigi; Rudenko, Andrey; Arras, Kai O.

    2015-01-01

    We introduce and show preliminary results of a fast randomized method that finds a set of K paths lying in distinct homotopy classes. We frame the path planning task as a graph search problem, where the navigation graph is based on a Voronoi diagram. The search is biased by a cost function derived from the social force model that is used to generate and select the paths. We compare our method to Yen's algorithm, and empirically show that our approach is faster to find a subset of homotopy cla...

  15. Parallel shooting methods for finding steady state solutions to engine simulation models

    DEFF Research Database (Denmark)

    Andersen, Stig Kildegård; Thomsen, Per Grove

    2007-01-01

    Parallel single- and multiple shooting methods were tested for finding periodic steady state solutions to a Stirling engine model. The model was used to illustrate features of the methods and possibilities for optimisations. Performance was measured using simulation of an experimental data set as test case. A parallel speedup factor of 23 on 33 processors was achieved with multiple shooting. But fast transients at the beginnings of sub intervals caused significant overhead for the multiple shooting methods and limited the best speedup to 3.8 relative to the fastest sequential method: Single shooting with reduced dimension of the boundary value problem.

  16. Centroid Position as a Function of Total Counts in a Windowed CMOS Image of a Point Source

    Energy Technology Data Exchange (ETDEWEB)

    Wurtz, R E; Olivier, S; Riot, V; Hanold, B J; Figer, D F

    2010-05-27

    We obtained 960,200 22-by-22-pixel windowed images of a pinhole spot using the Teledyne H2RG CMOS detector with un-cooled SIDECAR readout. We performed an analysis to determine the precision we might expect in the position error signals to a telescope's guider system. We find that, under non-optimized operating conditions, the error in the computed centroid is strongly dependent on the total counts in the point image only below a certain threshold, approximately 50,000 photo-electrons. The LSST guider camera specification currently requires a 0.04 arcsecond error at 10 Hertz. Given the performance measured here, this specification can be delivered with a single star at 14th to 18th magnitude, depending on the passband.

  17. Methods for synthesizing findings on moderation effects across multiple randomized trials.

    Science.gov (United States)

    Brown, C Hendricks; Sloboda, Zili; Faggiano, Fabrizio; Teasdale, Brent; Keller, Ferdinand; Burkhart, Gregor; Vigna-Taglianti, Federica; Howe, George; Masyn, Katherine; Wang, Wei; Muthén, Bengt; Stephens, Peggy; Grey, Scott; Perrino, Tatiana

    2013-04-01

    This paper presents new methods for synthesizing results from subgroup and moderation analyses across different randomized trials. We demonstrate that such a synthesis generally results in additional power to detect significant moderation findings above what one would find in a single trial. Three general methods for conducting synthesis analyses are discussed, with two methods, integrative data analysis and parallel analyses, sharing a large advantage over traditional methods available in meta-analysis. We present a broad class of analytic models to examine moderation effects across trials that can be used to assess their overall effect and explain sources of heterogeneity, and present ways to disentangle differences across trials due to individual differences, contextual level differences, intervention, and trial design. PMID:21360061

  18. A New Method for Finding the Thevenin and Norton Equivalent Circuits

    OpenAIRE

    George E. Chatzarakis

    2010-01-01

    The paper presents a new pedagogical method for finding the Thevenin and Norton equivalent circuits of a linear electric circuit (LEC) at the n-different pairs of terminals simultaneously, regardless of the circuit topology and complexity. The proposed method is appropriate for undergraduate electrical and electronic engineering students leading to straightforward solutions, mostly arrived at by inspection, so that it can be regarded as a simple and innovative calculation tool for Thevenin eq...

  19. Nudged-elastic band method with two climbing images: finding transition states in complex energy landscapes

    CERN Document Server

    Zarkevich, Nikolai A

    2014-01-01

    The nudged-elastic band (NEB) method is modified with concomitant two climbing images (C2-NEB) to find a transition state (TS) in complex energy landscapes, such as those with serpentine minimal energy path (MEP). If a single climbing image (C1-NEB) successfully finds the TS, C2-NEB finds it with higher stability and accuracy. However, C2-NEB is suitable for more complex cases, where C1-NEB misses the TS because the MEP and NEB directions near the saddle point are different. Generally, C2-NEB not only finds the TS but guarantees that the climbing images approach it from the opposite sides along the MEP, and it estimates accuracy from the three images: the highest-energy one and its climbing neighbors. C2-NEB is suitable for fixed-cell NEB and the generalized solid-state NEB (SS-NEB).

  20. Image Centroid Algorithms for Sun Sensors with Super Wide Field of View

    Directory of Open Access Journals (Sweden)

    ZHAN Yinhu

    2015-10-01

    Full Text Available Sun image centroid algorithm is one of the key technologies of celestial navigation using sun sensors, which directly determine the precision of the sensors. Due to the limitation of centroid algorithm for non-circular sun image of the sun sensor of large field of view, firstly, the ellipse fitting algorithm is proposed for solving elliptical or sub-elliptical sun images. Then the spherical circle fitting algorithm is put forward. Based on the projection model and distortion model of the camera, the spherical circle fitting algorithm is used to obtain the edge points of the sun in the object space, and then the centroid of the sun can be determined by fitting the edge points as a spherical circle. In order to estimate the precision of spherical circle fitting algorithm, the centroid of the sun should be projected back to the image space. Theoretically, the spherical circle fitting algorithm is no longer need to take into account the shape of the sun image, the algorithm is more precise. The results of practical sun images demonstrate that the ellipse fitting algorithm is more suitable for the sun image with 70°~80.3° half angle of view, and the mean precision is about 0.075 pixels; the spherical circle fitting algorithm is more suitable for the sun image with a half angle of view larger than 80.3°, and the mean precision is about 0.082 pixels.

  1. European-Mediterranean Regional Centroid Moment Tensor Catalog: Solutions for Years 2003 and 2004

    OpenAIRE

    Pondrelli, S.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Bologna, Bologna, Italia; Salimbeni, S.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Bologna, Bologna, Italia; Morelli, A.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Bologna, Bologna, Italia; Ekström, G.; Lamont-Doherty Earth Observatory, Columbia University, Palisades, NY, USA; Boschi, E.; Istituto Nazionale di Geofisica e Vulcanologia, Roma, Italy

    2007-01-01

    We present an update, for years 2003 and 2004, of the European– Mediterranean Regional Centroid Moment Tensor (RCMT) catalog that we maintain since 1997. This update adds 177 new solutions to the database, relating to moderate-magnitude (4.5 ?M

  2. Centroid-based summarization of multiple documents: sentence extraction, utility-based evaluation, and user studies

    OpenAIRE

    Radev, Dragomir R.; Jing, Hongyan; Budzikowska, Malgorzata

    2000-01-01

    We present a multi-document summarizer, called MEAD, which generates summaries using cluster centroids produced by a topic detection and tracking system. We also describe two new techniques, based on sentence utility and subsumption, which we have applied to the evaluation of both single and multiple document summaries. Finally, we describe two user studies that test our models of multi-document summarization.

  3. "Expectations to Change" ((E2C): A Participatory Method for Facilitating Stakeholder Engagement with Evaluation Findings

    Science.gov (United States)

    Adams, Adrienne E.; Nnawulezi, Nkiru A.; Vandenberg, Lela

    2015-01-01

    From a utilization-focused evaluation perspective, the success of an evaluation is rooted in the extent to which the evaluation was used by stakeholders. This paper details the "Expectations to Change" (E2C) process, an interactive, workshop-based method designed to engage primary users with their evaluation findings as a means of…

  4. A new method for direction finding based on Markov random field model

    Science.gov (United States)

    Ota, Mamoru; Kasahara, Yoshiya; Goto, Yoshitaka

    2015-07-01

    Investigating the characteristics of plasma waves observed by scientific satellites in the Earth's plasmasphere/magnetosphere is effective for understanding the mechanisms for generating waves and the plasma environment that influences wave generation and propagation. In particular, finding the propagation directions of waves is important for understanding mechanisms of VLF/ELF waves. To find these directions, the wave distribution function (WDF) method has been proposed. This method is based on the idea that observed signals consist of a number of elementary plane waves that define wave energy density distribution. However, the resulting equations constitute an ill-posed problem in which a solution is not determined uniquely; hence, an adequate model must be assumed for a solution. Although many models have been proposed, we have to select the most optimum model for the given situation because each model has its own advantages and disadvantages. In the present study, we propose a new method for direction finding of the plasma waves measured by plasma wave receivers. Our method is based on the assumption that the WDF can be represented by a Markov random field model with inference of model parameters performed using a variational Bayesian learning algorithm. Using computer-generated spectral matrices, we evaluated the performance of the model and compared the results with those obtained from two conventional methods.

  5. Finite difference method to find period-one gait cycles of simple passive walkers

    Science.gov (United States)

    Dardel, Morteza; Safartoobi, Masoumeh; Pashaei, Mohammad Hadi; Ghasemi, Mohammad Hassan; Navaei, Mostafa Kazemi

    2015-01-01

    Passive dynamic walking refers to a class of bipedal robots that can walk down an incline with no actuation or control input. These bipeds are sensitive to initial conditions due to their style of walking. According to small basin of attraction of passive limit cycles, it is important to start with an initial condition in the basin of attraction of stable walking (limit cycle). This paper presents a study of the simplest passive walker with point and curved feet. A new approach is proposed to find proper initial conditions for a pair of stable and unstable period-one gait limit cycles. This methodology is based on finite difference method which can solve the nonlinear differential equations of motion on a discrete time. Also, to investigate the physical configurations of the walkers and the environmental influence such as the slope angle, the parameter analysis is applied. Numerical simulations reveal the performance of the presented method in finding two stable and unstable gait patterns.

  6. 4D tumor centroid tracking using orthogonal 2D dynamic MRI: Implications for radiotherapy planning

    Energy Technology Data Exchange (ETDEWEB)

    Tryggestad, Erik [Department of Radiation Oncology and Molecular Radiation Sciences, The Johns Hopkins University School of Medicine, Baltimore, Maryland 21231 and Department of Radiation Oncology, Mayo Clinic, Rochester, Minnesota 55905 (United States); Flammang, Aaron; Shea, Steven M. [Center for Applied Medical Imaging, Siemens Corporation, Corporate Technology, Baltimore, Maryland 21205 (United States); Hales, Russell; Herman, Joseph; Lee, Junghoon; McNutt, Todd; Roland, Teboh; Wong, John [Department of Radiation Oncology and Molecular Radiation Sciences, The Johns Hopkins University School of Medicine, Baltimore, Maryland 21231 (United States)

    2013-09-15

    Purpose: Current pretreatment, 4D imaging techniques are suboptimal in that they sample breathing motion over a very limited “snapshot” in time. Heretofore, long-duration, 4D motion characterization for radiotherapy planning, margin optimization, and validation have been impractical for safety reasons, requiring invasive markers imaged under x-ray fluoroscopy. To characterize 3D tumor motion and associated variability over durations more consistent with treatments, the authors have developed a practical dynamic MRI (dMRI) technique employing two orthogonal planes acquired in a continuous, interleaved fashion.Methods: 2D balanced steady-state free precession MRI was acquired continuously over 9–14 min at approximately 4 Hz in three healthy volunteers using a commercial 1.5 T system; alternating orthogonal imaging planes (sagittal, coronal, sagittal, etc.) were employed. The 2D in-plane pixel resolution was 2 × 2 mm{sup 2} with a 5 mm slice profile. Simultaneous with image acquisition, the authors monitored a 1D surrogate respiratory signal using a device available with the MRI system. 2D template matching-based anatomic feature registration, or tracking, was performed independently in each orientation. 4D feature tracking at the raw frame rate was derived using spline interpolation.Results: Tracking vascular features in the lung for two volunteers and pancreatic features in one volunteer, the authors have successfully demonstrated this method. Registration error, defined here as the difference between the sagittal and coronal tracking result in the SI direction, ranged from 0.7 to 1.6 mm (1?) which was less than the acquired image resolution. Although the healthy volunteers were instructed to relax and breathe normally, significantly variable respiration was observed. To demonstrate potential applications of this technique, the authors subsequently explored the intrafraction stability of hypothetical tumoral internal target volumes and 3D spatial probability distribution functions. The surrogate respiratory information allowed the authors to show how this technique can be used to study correlations between internal and external (surrogate) information over these prolonged durations. However, compared against the gold standard of the time stamps in the dMRI frames, the temporal synchronization of the surrogate 1D respiratory information was shown to be likely unreliable.Conclusions: The authors have established viability of a novel and practical pretreatment, 4D tumor centroid tracking method employing a commercially available dynamic MRI sequence. Further developments from the vendor are likely needed to provide a reliably synchronized surrogate 1D respiratory signal, which will likely broaden the utility of this method in the pretreatment radiotherapy planning context.

  7. A Root-MUSIC-Like Direction Finding Method for Cyclostationary Signals

    Directory of Open Access Journals (Sweden)

    Yide Wang

    2005-01-01

    Full Text Available We propose a new root-MUSIC-like direction finding algorithm that exploits cyclostationarity in order to improve the direction-of-arrival estimation. The proposed cyclic method is signal selective, it allows to increase the resolution power and the noise robustness significantly, and it is also able to handle more sources than the number of sensors. Computer simulations are used to show the performance of the algorithm.

  8. A novel method for finding the initial structure parameters of optical systems via a genetic algorithm

    Science.gov (United States)

    Jun, LIU; Huang, Wei; Hongjie, Fan

    2016-02-01

    A novel method for finding the initial structure parameters of an optical system via the genetic algorithm (GA) is proposed in this research. Usually, optical designers start their designs from the commonly used structures from a patent database; however, it is time consuming to modify the patented structures to meet the specification. A high-performance design result largely depends on the choice of the starting point. Accordingly, it would be highly desirable to be able to calculate the initial structure parameters automatically. In this paper, a method that combines a genetic algorithm and aberration analysis is used to determine an appropriate initial structure of an optical system. We use a three-mirror system as an example to demonstrate the validity and reliability of this method. On-axis and off-axis telecentric three-mirror systems are obtained based on this method.

  9. An Approach for registration method to find corresponding mass lesions in temporal mammogram pairs

    Directory of Open Access Journals (Sweden)

    Prof. Samir Kumar Bandyopadhyay

    2010-11-01

    Full Text Available Radiologists generally use multiple mammographic views to detect and characterize suspiciousregions. When radiologists discover a suspicious lesion in one view, they try to find a corresponding lesion in the other views. Views from different projections, typically cranio caudal (CC and medio lateral oblique (MLO views, allow for a better realization of the lesion. Most current computer aided detection (CAD systems differ considerably from radiologists in the way they use multiple views. These systems do not combine information from available views but instead analyse each view separately. Given the positive effect of multiview systems on radiologists' performance we expect that fusion of information from different views will improve CAD systems as well. Such multi-view CAD programs require regional registration methods to find corresponding regions in all available views. In this paper we concentrate on developing such a method for corresponding mass lesions in prior and In other words, starting from a current image containing a mass lesion, the method aims at locating the same mass lesion in the prior image. The method was tested on a set of 412 cancer cases. In each case a malignant mass, architectural distortion or asymmetry was annotated. In 92% of these cases the candidate mass detections by CAD included the cancer regions in both views. It was found that in 82% of the cases a correct link between the true. Positive regions in both views could be established by our method.Key words: Multiple View, Computer-Aided Detection, masses, mammography

  10. Optimization of soy isoflavone extraction with different solvents using the simplex-centroid mixture design.

    Science.gov (United States)

    Yoshiara, Luciane Yuri; Madeira, Tiago Bervelieri; Delaroza, Fernanda; da Silva, Josemeyre Bonifácio; Ida, Elza Iouko

    2012-12-01

    The objective of this study was to optimize the extraction of different isoflavone forms (glycosidic, malonyl-glycosidic, aglycone and total) from defatted cotyledon soy flour using the simplex-centroid experimental design with four solvents of varying polarity (water, acetone, ethanol and acetonitrile). The obtained extracts were then analysed by high-performance liquid chromatography. The profile of the different soy isoflavones forms varied with different extractions solvents. Varying the solvent or mixture used, the extraction of different isoflavones was optimized using the centroid-simplex mixture design. The special cubic model best fitted to the four solvents and its combination for soy isoflavones extraction. For glycosidic isoflavones extraction, the polar ternary mixture (water, acetone and acetonitrile) achieved the best extraction; malonyl-glycosidic forms were better extracted with mixtures of water, acetone and ethanol. Aglycone isoflavones, water and acetone mixture were best extracted and total isoflavones, the best solvents were ternary mixture of water, acetone and ethanol. PMID:22621769

  11. Exponential tails in the centroid velocity distributions of star-forming regions

    CERN Document Server

    Miesch, M S; Miesch, Mark S; Scalo, John M

    1994-01-01

    Probability density functions (pdfs) of ^{13}CO emission line centroid (line-of-sight, intensity-weighted average) velocities are presented for several densely sampled molecular clouds as quantitative descriptors of their underlying dynamics. Although some are approximately Gaussian in form, most of the pdfs exhibit relatively broader, often nearly exponential, tails, similar to the pdfs of velocity {\\em differences} and {\\em derivatives} (but not the velocity field itself) found in experiments and numerical simulations of incompressible turbulence. The broad pdf tails found in the present work are also similar to those found in decades-old measurements of interstellar velocity pdfs using atomic line centroids, and to the excess wing emission recently found in individual molecular line profiles. Some possible interpretations of the observed deviations are briefly discussed, although none of these account for the nearly exponential tails.

  12. Methods and findings of a systems interaction study of a Westinghouse PWR

    International Nuclear Information System (INIS)

    This paper describes the methods and findings of a systems interaction study of a Westinghouse PWR. BNL conducted the study as a methods application that was performed to support the resolution of Unresolved Safety Issue A-17 on Systems Interactions. The method calls for a fault tree model of the plant to be developed in stages, corresponding to successively increasing levels of scope and detail. A functional model is developed first, resolved only to sufficient detail to reflect support system dependences; this guides the subsequent searches for spatial and induced-human interactions. This process has led to the identification of an active single failure causing loss of low pressure injection following a large or medium LOCA

  13. Sum rules for isospin centroids in pick-up reactions on general multishell target states

    OpenAIRE

    Bansal, R. K.; Sharda, H.; KUMAR, Ashwani

    1997-01-01

    Sum Rules equations for pick-up reactions are presented for the first time for the energy centroids of states both for the isospin T_ (\\equiv T_0 + {1 \\over 2}) of the final nucleus when a nucleon is picked up from a general multishell target state with isospin T_0. These equations contain two-body correlation terms, , which, at the present moment, are difficult to handle analytically. These terms are managed by combining these equations wit...

  14. Fast simulators for satellite cloud optical centroid pressure retrievals, 1. evaluation of OMI cloud retrievals

    OpenAIRE

    J. Joiner; A. P. Vasilkov; Gupta, P.; Bhartia, P. K.; P. Veefkind; M. Sneep; Haan, J. de; Polonsky, I.; R. Spurr

    2011-01-01

    The cloud Optical Centroid Pressure (OCP) is a satellite-derived parameter that is commonly used in trace-gas retrievals to account for the effects of clouds on near-infrared through ultraviolet radiance measurements. A fast simulator is desirable in order to further expand the use of cloud OCP retrievals into the operational and climate communities for applications such as data assimilation and evaluation of cloud vertical structure in general circulation models. In this paper, we ...

  15. European Mediterranean Regional Centroid Moment Tensor catalog: Solutions for years 2003 and 2004

    Science.gov (United States)

    Pondrelli, S.; Salimbeni, S.; Morelli, A.; Ekström, G.; Boschi, E.

    2007-09-01

    We present an update, for years 2003 and 2004, of the European- Mediterranean Regional Centroid Moment Tensor (RCMT) catalog that we maintain since 1997. This update adds 177 new solutions to the database, relating to moderate-magnitude ( 4.5?MHoceima, Morocco in 2004) and in Southern Greece and Dodecanese region (August 2003 and 2004). The complete RCMT catalog for the European and Mediterranean region now covers 8 years, and contains about 600 solutions.

  16. Fast simulators for satellite cloud optical centroid pressure retrievals; evaluation of OMI cloud retrievals

    OpenAIRE

    Joiner, J.; Vasilkov, A. P.; Gupta, P; Bhartia, P. K.; Veefkind, P.; Sneep, M.; Haan, J. de; I. Polonsky; Spurr, R.

    2012-01-01

    The cloud Optical Centroid Pressure (OCP) is a satellite-derived parameter that is commonly used in trace-gas retrievals to account for the effects of clouds on near-infrared through ultraviolet radiance measurements. Fast simulators are desirable to further expand the use of cloud OCP retrievals into the operational and climate communities for applications such as data assimilation and evaluation of cloud vertical structure in general circulation models. In this paper, we develop and validat...

  17. A Centroid-based Heuristic Algorithm for the Capacitated Vehicle Routing Problem

    OpenAIRE

    Kwangcheol Shin; Sangyong Han

    2012-01-01

    The vehicle routing problem (VRP) is famous as a nondeterministic polynomial-time hard problem. This study proposes a centroid-based heuristic algorithm to solve the capacitated VRP in polynomial time. The proposed algorithm consists of three phases: cluster construction, cluster adjustment, and route establishment. At the cluster construction phase, the farthest node (customer) among un-clustered nodes is selected as a seed to form a cluster. The notion of the geometrical centre of a cluster...

  18. Minima Hopping Accelerated Path Search: An Efficient Method for Finding Complex Chemical Reaction Pathways

    CERN Document Server

    Schaefer, Bastian; Amsler, Maximilian; Goedecker, Stefan

    2014-01-01

    Based on Minima Hopping and its capabilities of exploring potential energy surfaces we have developed Minima Hopping Accelerated Path Search (MHAPS) which is a novel algorithm for efficiently finding the reaction paths of complex chemical reactions by sampling collections of energetically low-lying minima and first order saddle points of potential energy surfaces. For this new reaction path search method we developed a highly reliable approach for computing saddle points which is based on the idea of a bar rolling downwards the potential energy landscape. For Lennard-Jones benchmark systems, Minima Hopping Accelerated Path Search was compared to a known mode-following based approach for sampling collections of minima and first order transition states. Although we used a stabilized mode-following technique that reliably allows to follow distinct directions that are defined by the eigenvectors of the Hessian matrix, we observed that Minima Hopping Accelerated Path Search is far superior in finding lowest-barrie...

  19. Enhancing spatial resolution of soft x-ray CCD detectors by single-photon centroid determination

    CERN Document Server

    Amorese, Andrea; Braicovich, Lucio; Ghiringhelli, Giacomo

    2014-01-01

    In Charge Coupled Device (CCD) detectors the electrons excited upon absorption of a single x-ray photon quickly diffuse and generate charge-spots often larger than pixel dimensions. In the soft x-ray range this phenomenon drastically limits the effective spatial resolution to approximately 25\\mu m, irrespective of the pixel size. For very low fluence the charge-cloud centroid determination can be used, on each individual spot, to estimate the actual photon impact position with sub-pixel precision. The readout noise and speed, together with the charge and spatial undersampling, are the main factors limiting the accuracy of this procedure in commercial devices. We have developed and extensively tested an algorithm for efficient centroid reconstruction on images acquired by low noise detectors not designed for single photon counting. We have thus measured a position uncertainty of 6-7\\mu m in CCDs with 13.5\\mu m and 20.0\\mu m pixel size, around 1 keV photon energy. We have analyzed the centroid calculation perfo...

  20. A Lin's method approach to finding and continuing heteroclinic connections involving periodic orbits

    International Nuclear Information System (INIS)

    We present a numerical method for finding and continuing heteroclinic connections of vector fields that involve periodic orbits. Specifically, we concentrate on the case of a codimension-d heteroclinic connection from a saddle equilibrium to a saddle periodic orbit, denoted EtoP connection for short. By employing a Lin's method approach we construct a boundary value problem that has as its solution two orbit segments, one from the equilibrium to a suitable section ? and the other from ? to the periodic orbit. The difference between their two end points in ? can be chosen in a d-dimensional subspace, and this gives rise to d well-defined test functions that are called the Lin gaps. A connecting orbit can be found in a systematic way by closing the Lin gaps one by one in d consecutive continuation runs. Indeed, any common zero of the Lin gaps corresponds to an EtoP connection, which can then be continued in system parameters. The performance of our method is demonstrated with a number of examples. Specifically, we computate different types of EtoP orbits in the Lorenz system, in a vector-field model of a saddle-node Hopf bifurcation with global reinjection and in a four-dimensional Duffing-type system. Finally, we demonstrate the versatility of our geometric approach by finding a codimension-zero heteroclinic connection between two saddle periodic orbits in a four-dimensional vector field

  1. A method for finding the ridge between saddle points applied to rare event rate estimates

    DEFF Research Database (Denmark)

    Maronsson, Jon Bergmann; Jónsson, Hannes

    2012-01-01

    A method is presented for finding the ridge between first order saddle points on a multidimensional surface. For atomic scale systems, such saddle points on the energy surface correspond to atomic rearrangement mechanisms. Information about the ridge can be used to test the validity of the harmonic approximation to transition state theory, in particular to verify that second order saddle points—maxima along the ridge—are high enough compared to the first order saddle points. New minima along the ridge can also be identified during the path optimisation, thereby revealing additional transition mechanisms. The method is based on a string of discretisation points along a path between the first order saddle points and using an iterative optimisation which requires only the force acting on the atoms. At each iteration during the optimisation, the force is inverted along an unstable eigenmode perpendicular to the path. The method is applied to Al adatom diffusion on the Al(100) surface to find the ridge between 2-,3- and 4-atom concerted displacements and hop mechanisms. A correction to the harmonic approximation of transition state theory was estimated by direct evaluation of the configuration integral along the ridge.

  2. A simple method for finding explicit analytic transition densities of diffusion processes with general diploid selection.

    Science.gov (United States)

    Song, Yun S; Steinrücken, Matthias

    2012-03-01

    The transition density function of the Wright-Fisher diffusion describes the evolution of population-wide allele frequencies over time. This function has important practical applications in population genetics, but finding an explicit formula under a general diploid selection model has remained a difficult open problem. In this article, we develop a new computational method to tackle this classic problem. Specifically, our method explicitly finds the eigenvalues and eigenfunctions of the diffusion generator associated with the Wright-Fisher diffusion with recurrent mutation and arbitrary diploid selection, thus allowing one to obtain an accurate spectral representation of the transition density function. Simplicity is one of the appealing features of our approach. Although our derivation involves somewhat advanced mathematical concepts, the resulting algorithm is quite simple and efficient, only involving standard linear algebra. Furthermore, unlike previous approaches based on perturbation, which is applicable only when the population-scaled selection coefficient is small, our method is nonperturbative and is valid for a broad range of parameter values. As a by-product of our work, we obtain the rate of convergence to the stationary distribution under mutation-selection balance. PMID:22209899

  3. A novel method to find the neutral position of the breast

    OpenAIRE

    Knight, Miranda; Wheat, Jon; Driscoll, Heather; Haake, Steve

    2014-01-01

    Breast pain affects up to 70% of the female population. It is believed that stretching of the breast tissue causes discomfort and that by placing the breast into a position in which the tissue is neither in compression or tension (termed neutral position) will eliminate breast pain. The purpose of the study was to find a simple method that could be used to determine the location of the neutral position. One participant with a breast size of 34C performed three activities. The breast and torso...

  4. Reconciling incongruous qualitative and quantitative findings in mixed methods research: exemplars from research with drug using populations

    OpenAIRE

    WAGNER, KARLA D.; Davidson, Peter J.; Pollini, Robin A; STRATHDEE, Steffanie A; Washburn, Rachel; Palinkas, Lawrence A.

    2011-01-01

    Mixed methods research is increasingly being promoted in the health sciences as a way to gain more comprehensive understandings of how social processes and individual behaviours shape human health. Mixed methods research most commonly combines qualitative and quantitative data collection and analysis strategies. Often, integrating findings from multiple methods is assumed to confirm or validate the findings from one method with the findings from another, seeking convergence or agreement betwe...

  5. Centroid and Envelope Dynamics of High-intensity Charged Particle Beams in an External Focusing Lattice and Oscillating Wobbler

    International Nuclear Information System (INIS)

    The centroid and envelope dynamics of a high-intensity charged particle beam are investigated as a beam smoothing technique to achieve uniform illumination over a suitably chosen region of the target for applications to ion-beam-driven high energy density physics and heavy ion fusion. The motion of the beam centroid projected onto the target follows a smooth pattern to achieve the desired illumination, for improved stability properties during the beam-target interaction. The centroid dynamics is controlled by an oscillating 'wobbler', a set of electrically-biased plates driven by RF voltage.

  6. Application of a Bayesian method to absorption spectral-line finding in simulated ASKAP data

    CERN Document Server

    Allison, J R; Whiting, M T

    2011-01-01

    The large spectral bandwidth and wide field-of-view of the Australian SKA Pathfinder radio telescope will open up a completely new parameter space for large extragalactic HI surveys. Here we focus on identifying and parametrising HI absorption-lines which occur in the line of sight towards strong radio continuum sources. We have developed a method for simultaneously finding and fitting HI absorption-lines in radio data by using multi-nested sampling, a Bayesian Monte-arlo algorithm. The method is tested on a simulated ASKAP data cube, and is shown to be reliable at detecting absorption-lines in low signal-to-noise data without the need to smooth or alter the data. Estimation of the local Bayesian evidence statistic provides a quantitative criterion for assigning significance to a detection and selecting between competing analytical line-profile models.

  7. Application of Artificial Intelligence methods in Finding Program Comprehension Differences in Novice Object Oriented Programmers

    Directory of Open Access Journals (Sweden)

    Marzieh Ahmadzadeh

    2013-09-01

    Full Text Available Program comprehension is the first step required for software maintenance, which accounts for a considerable number of job opportunities. For this to happen, it seems obvious that improving this ability in the teaching environment is required. The literature shows, however, that not enough solutions for improving program comprehension are offered as much as for programming itself.The aim of this research therefore, is to find a pattern of how different students vary in terms of comprehending a code written in an object-oriented language. For this, we have focused on two concepts including inheritance and polymorphism, gathered data online and analyzed it qualitatively. To find the right subject for all the students to study, a data mining technique i.e., the K-means clustering algorithm, was used.Results showed that a slight difference in programming experience can have a significant impact on program comprehension ability. The methods that were used by participants who succeeded in the experiment were the same as methods used by experts as mentioned in earlier research. Inheritance and polymorphism did not play an important role in lack of success in the process of program comprehension.

  8. Establishing the soft and hard tissue area centers (centroids) for the skull and introducing a newnon-anatomical cephalometric line

    International Nuclear Information System (INIS)

    The purpose of this study was to demonstrate how to establish the area center (centroid) of both the soft and hard tissues of the outline of the lateral cephalometric skull image, and to introduce the concept of a new non-anatomical centroid line. Lateral cephalometric radiographs, size 12 x 14 inch, of fifty seven adult subjects were selected based on their pleasant, balanced profile, Class I skeletal and dental relationship and no major dental malocclusion or malrelationship. The area centers (centroids) of both soft and hard tissue skull were practically established using a customized software computer program called the m-file. Connecting the two centers introduced the concept of a new non-anatomical soft and hard centroids line. (author)

  9. Finding transition pathways using the string method with swarms of trajectories.

    Science.gov (United States)

    Pan, Albert C; Sezer, Deniz; Roux, Benoît

    2008-03-20

    An approach to find transition pathways in complex systems is presented. The method, which is related to the string method in collective variables of Maragliano et al. (J. Chem. Phys. 2006, 125, 024106), is conceptually simple and straightforward to implement. It consists of refining a putative transition path in the multidimensional space supported by a set of collective variables using the average dynamic drift of those variables. This drift is estimated on-the-fly via swarms of short unbiased trajectories started at different points along the path. Successive iterations of this algorithm, which can be naturally distributed over many computer nodes with negligible interprocessor communication, refine an initial trial path toward the most probable transition path (MPTP) between two stable basins. The method is first tested by determining the pathway for the C7eq to C7ax transition in an all-atom model of the alanine dipeptide in vacuum, which has been studied previously with the string method in collective variables. A transition path is found with a committor distribution peaked at 1/2 near the free energy maximum, in accord with previous results. Last, the method is applied to the allosteric conformational change in the nitrogen regulatory protein C (NtrC), represented here with a two-state elastic network model. Even though more than 550 collective variables are used to describe the conformational change, the path converges rapidly. Again, the committor distribution is found to be peaked around 1/2 near the free energy maximum between the two stable states, confirming that a genuine transition state has been localized in this complex multidimensional system. PMID:18290641

  10. Study of finding out uranium deposit with geophysical methods at Zhongdong district Onyuan county Guangdong province

    International Nuclear Information System (INIS)

    The soil natural thermoluminescence measurement and radon survey were chosen, whose penetrability is stronger, and their applied effects were studied in prospecting uranium deposit at Xiazhuang granite area. The 236 stations were measured respectively with these two methods at Zhongdong district Ongyuan county Guangdong province. The research results show that: 1. There are good effects which fractured zones were found out with radon survey. 2. The soil natural thermoluminescence measurement is one of the cumulative measurement methods. It can obviously respond the projected position of uranium deposit of intersected point type. 3. The sensitivity, stability and reappearance of the soil natural thermoluminescence is good, and it was less affected by human activity on the surface. The measured anomalies can reflect the variety of the radioactive field, so amplitude and width of anomalies can basically respond the distribution of uranium ore body. The problems to be solved in the future are: If the rocks above the 'intersection point type' uranium deposits are relatively intact, how much depth can it be found out with soil natural thermoluminescence method? A set of nuclear geophysical prospecting pattern on the different types of uranium deposits in Xiazhuang uranium ore field should be summarized so that they can be used to find out uranium deposits in granite area in the future. (authors)

  11. A Bayesian Method For Finding Galaxies That Cause Quasar Absorption Lines

    Science.gov (United States)

    Shoemaker, Emileigh Suzanne; Laubner, David Andrew; Scott, Jennifer E.

    2016-01-01

    We present a study of candidate absorber-galaxy pairs for 39 low redshift quasar sightlines (0.06 Digital Sky Survey (SDSS). We downloaded the COS linelists for these quasar spectra from MAST and queried the SDSS DR12 database for photometric data on all galaxies within 1 Mpc of each of these quasar lines of sight. We calculated photometric redshifts for all the SDSS galaxies using the Bayesian Photometric Redshift code. We used all these absorber and galaxy data as input into an absorber-galaxy matching code which also employs a Bayesian scheme, along with known statistics of the intergalactic medium and circumgalactic media of galaxies, for finding the most probable galaxy match for each absorber. We compare our candidate absorber-galaxy matches to existing studies in the literature and explore trends in the absorber and galaxy properties among the matched and non-matched populations. This method of matching absorbers and galaxies can be used to find targets for follow up spectroscopic studies.

  12. Centers and centroids of the cone-beam projection of a ball

    International Nuclear Information System (INIS)

    In geometric calibration of cone-beam (CB) scanners, point-like marker objects such as small balls are imaged to obtain positioning information from which the unknown geometric parameters are extracted. The procedure is sensitive to errors in the positioning information, and one source of error is a small bias which can occur in estimating the detector locations of the CB projections of the centers of the balls. We call these detector locations the center projections. In general, the CB projection of a ball of uniform density onto a flat detector forms an ellipse. Inside the ellipse lie the center projection M, the ellipse center C and the centroid G of the intensity values inside the ellipse. The center projection is invariably estimated from C or G which are much easier to extract directly from the data. In this work, we quantify the errors incurred in using C or G to estimate M. We prove mathematically that the points C, G, M and O are always distinct and lie on the major axis of the ellipse, where O is the detector origin, defined as the orthogonal projection of the cone vertex onto the detector. (The ellipse can only degenerate to a circle if the ball is along the direct line of sight to O, and in this case all four points coincide.) The points always lie in the same order: O, M, G, C which establishes that the centroid has less geometric bias than the ellipse center for estimating M. However, our numerical studies indicate that the centroid bias is only 20% less than the ellipse center bias so the benefit in using centroid estimates is not substantial. For the purposes of quantifying the bias in practice, we show that the ellipse center bias ||CM|| can be conveniently estimated by eA/(? f-tilde) where A is the area of the elliptical projection, e is the eccentricity of the ellipse and f-tilde is an estimate of the focal length of the system. Finally, we discuss how these results are affected by physical factors such as beam hardening, and indicate extensions to balls of non-uniform density.

  13. Comparação dos métodos de determinação da estabilidade oxidativa de biodiesel B100, em mistura com antioxidantes sintéticos: aplicação do delineamento simplex-centroide com variável de processo

    Directory of Open Access Journals (Sweden)

    João Rafael de Moraes Cini

    2013-01-01

    Full Text Available The Rancimat and accelerated stove tests were used to determine the oxidative stability of B100 biodiesel mixed with synthetic antioxidants. The predictive equations, with process variable, were obtained by applying a simplex-centroid design. Regardless of the antioxidant used, all assays carried out with the accelerated stove test presented storage time longer than 177.88 d, the greatest value obtained by applying the Rancimat test. The t test, applied to the parameters containing the process variable, showed a statistically significant difference (at the level of 5% between the methods used.

  14. Multiple-precision zero-finding methods and the complexity of elementary function evaluation

    CERN Document Server

    Brent, Richard P

    2010-01-01

    We consider methods for finding high-precision approximations to simple zeros of smooth functions. As an application, we give fast methods for evaluating the elementary functions log(x), exp(x), sin(x) etc. to high precision. For example, if x is a positive floating-point number with an n-bit fraction, then (under rather weak assumptions) an n-bit approximation to log(x) or exp(x) may be computed in time asymptotically equal to 13M(n)lg(n), where M(n) is the time required to multiply floating-point numbers with n-bit fractions. Similar results are given for the other elementary functions. Some analogies with operations on formal power series (over a field of characteristic zero) are discussed. In particular, it is possible to compute the first n terms in log(1 + a_1.x + ...) or exp(a_1.x + ...) in time O(M(n)), where M(n) is the time required to multiply two polynomials of degree n - 1. It follows that the first n terms in a q-th power (1 + a_1.x + ...)^q can be computed in time O(M(n)), independent of q. One...

  15. School Locations and Traffic Emissions — Environmental (InJustice Findings Using a New Screening Method

    Directory of Open Access Journals (Sweden)

    Philine Gaffron

    2015-02-01

    Full Text Available It has been shown that the location of schools near heavily trafficked roads can have detrimental effects on the health of children attending those schools. It is therefore desirable to screen both existing school locations and potential new school sites to assess either the need for remedial measures or suitability for the intended use. Current screening tools and public guidance on school siting are either too coarse in their spatial resolution for assessing individual sites or are highly resource intensive in their execution (e.g., through dispersion modeling. We propose a new method to help bridge the gap between these two approaches. Using this method, we also examine the public K-12 schools in the Sacramento Area Council of Governments Region, California (USA from an environmental justice perspective. We find that PM2.5 emissions from road traffic affecting a school site are significantly positively correlated with the following metrics: percent share of Black, Hispanic and multi-ethnic students, percent share of students eligible for subsidized meals. The emissions metric correlates negatively with the schools’ Academic Performance Index, the share of White students and average parental education levels. Our PM2.5 metric also correlates with the traffic related, census tract level screening indicators from the California Communities Environmental Health Screening Tool and the tool’s tract level rate of asthma related emergency department visits.

  16. School locations and traffic emissions—environmental (in)justice findings using a new screening method.

    Science.gov (United States)

    Gaffron, Philine; Niemeier, Deb

    2015-02-01

    It has been shown that the location of schools near heavily trafficked roads can have detrimental effects on the health of children attending those schools. It is therefore desirable to screen both existing school locations and potential new school sites to assess either the need for remedial measures or suitability for the intended use. Current screening tools and public guidance on school siting are either too coarse in their spatial resolution for assessing individual sites or are highly resource intensive in their execution (e.g., through dispersion modeling). We propose a new method to help bridge the gap between these two approaches. Using this method, we also examine the public K-12 schools in the Sacramento Area Council of Governments Region, California (USA) from an environmental justice perspective. We find that PM2.5 emissions from road traffic affecting a school site are significantly positively correlated with the following metrics: percent share of Black, Hispanic and multi-ethnic students, percent share of students eligible for subsidized meals. The emissions metric correlates negatively with the schools' Academic Performance Index, the share of White students and average parental education levels. Our PM2.5 metric also correlates with the traffic related, census tract level screening indicators from the California Communities Environmental Health Screening Tool and the tool's tract level rate of asthma related emergency department visits. PMID:25679341

  17. A MODIFIED ALGORITHM FOR THRESHOLDING AND DETECTION OF FACIAL INFORMATION FROM COLOR IMAGES USING COLOR CENTROID SEGMENTATION AND CONTOURLET TRANSFORM

    Directory of Open Access Journals (Sweden)

    Sunish Kumar O S

    2011-06-01

    Full Text Available Human face detection plays an important role in many application areas such as video surveillance, human computer interface, face recognition, face search and face image database management etc. In human face detection applications, face region usually form an inconsequential part of images. Preliminary segmentation of images into regions that contain "non-face" objects and regions that may contain "face" can greatly accelerate the process of human face detection. This can be done using skin color segmentation, where given image is segmented based on color as 'skin region' and 'non skin regions'. Thus we can say that the skin regions may contain face and other regions don't. Color information based methods take a great attention, because colors have obviously character and robust visual cue for detection. This paper proposes a method based on RGB color centroids segmentation (CCS for face detection. This paper includes two parts, first part is color image thresholding based on CCS to perform skin color segmentation and the then detection of human face from detected skin regions. CCS method has some shortcomings as it fails when the skin color of the subject lacks chroma. This happens especially with subjects having too darker or too lighter skin tones. This shortcoming of CCS can be overcome using Contourlet Transformation. In this paper, we pursue a two dimensional transform that can capture the intrinsic geometrical structure that is key in visual information.

  18. A Modified Algorithm for Thresholding and Detection of Facial Information From Color Images Using Color Centroid Segmentation and Contourlet Transform

    Directory of Open Access Journals (Sweden)

    Sunish Kumar O S

    2011-09-01

    Full Text Available Human face detection plays an important role in many application areas such as video surveillance, human computer interface, face recognition, face search and face image database management etc. In human face detection applications, face region usually form an inconsequential part of images. Preliminary segmentation of images into regions that contain "non-face" objects and regions that may contain "face" can greatly accelerate the process of human face detection. This can be done using skin color segmentation, where given image is segmented based on color as 'skin region' and 'non skin regions'. Thus we can say that the skin regions may contain face and other regions don't. Color information based methods take a great attention, because colors have obviously character and robust visual cue for detection. This paper proposes a method based on RGB color centroids segmentation (CCS for face detection. This paper includes two parts, first part is color image thresholding based on CCS to perform skin color segmentation and the then detection of human face from detected skin regions. CCS method has some shortcomings as it fails when the skin color of the subject lacks chroma. This happens especially with subjects having too darker or too lighter skin tones. This shortcoming of CCS can be overcome using Contourlet Transformation. In this paper, we pursue a two dimensional transform that can capture the intrinsic geometrical structure that is key in visual information.

  19. Old Wine in New Skins: The Sensitivity of Established Findings to New Methods

    Science.gov (United States)

    Foster, E. Michael; Wiley-Exley, Elizabeth; Bickman, Leonard

    2009-01-01

    Findings from an evaluation of a model system for delivering mental health services to youth were reassessed to determine the robustness of key findings to the use of methodologies unavailable to the original analysts. These analyses address a key concern about earlier findings--that the quasi-experimental design involved the comparison of two…

  20. Update of the European-Mediterranean Regional Centroid Moment Tensor (RCMT) Catalog: an Insight on Notable Recent Mediterranean Seismicity

    Science.gov (United States)

    Pondrelli, S.; Salimbeni, S.; Ekström, G.; Morelli, A.

    2006-12-01

    The European-Mediterranean Regional Centroid Moment Tensor (RCMT) Catalog collects solutions routinely computed since 1997 for earthquakes with moderate magnitude (4.5? M ? 5.5) in the Mediterranean region. The database represents an extension to smaller magnitudes of the Harvard global CMT catalog, based on analysis of seismograms recorded at regional distance, and modeling of intermediate period surface waves. The catalog, updated to 2005, includes about 650 events, and represents a valuable tool for seismotectonic and geodynamic studies. The most interesting seismic sequences in the most recent years occurred in Northern Africa (Boumerdes, Algerian coast in 2003 and Al Hoceima, Morocco in 2004) and in the Southern Greece, Dodecanese area and Aegean Sea (August 2003 and 2004, October 2005). For most of the events of these sequences moment tensor solutions were not available in the literature. We further extended the catalog back in time for the Italian region, as far as allowed by availability of digital data --- i.e. since 1977 --- with the same analysis and inversion method used for current seismicity. The new dataset includes events in many seismic zones where moderate seismicity had previously been scarcely documented, e.g. the Po Plain and the Adriatic Sea. In particular, both older and more recent seismicity in the Central Adriatic Sea holds particular interest, as the region had often been depicted as aseismic. New solutions, providing new information on the geometry of seismic deformation, mainly represent moderate magnitude events, that can effectively be modeled by the method we use.

  1. Localization Accuracy Improved Methods Based on Adaptive Weighted Centroid Localization Algorithm in Wireless Sensor Networks

    OpenAIRE

    Kee-Wook Rim; Kyung-Yong Chung; Jung-Hyun Lee2; Jun-Ling Ma; Chang-Woo Song

    2010-01-01

    Generally, see Localization of nodes is a key technology for application of wireless sensor network. Having a GPS receiver on every sensor node is costly. In the past, several approaches, including range-based and range-free, have been proposed to calculate positions for randomly deployed sensor nodes. Most of them use some special nodes, called anchor nodes, which are assumed to know their own locations. Other sensors compute their locations based on the information provided by these anchor ...

  2. Research on the effect of noise at different times of day: Models, methods and findings

    Science.gov (United States)

    Fields, J. M.

    1985-01-01

    Social surveys of residents' responses to noise at different times of day are reviewed. Some of the discrepancies in published reports about the importance of noise at different times of day are reduced when the research findings are classified according to the type of time of day reaction model, the type of time of day weight calculated and the method which is used to estimate the weight. When the estimates of nighttime weights from 12 studies are normalized, it is found that they still disagree, but do not support stronger nighttime weights than those used in existing noise indices. Challenges to common assumptions in nighttime response models are evaluated. Two of these challenges receive enough support to warrant further investigation: the impact of changes in numbers of noise events may be less at night than in the day and nighttime annoyance may be affected by noise levels in other periods. All existing social survey results in which averages of nighttime responses were plotted by nighttime noise levels are reproduced.

  3. Findings from a mixed-methods study of an interprofessional faculty development program.

    Science.gov (United States)

    Abu-Rish Blakeney, Erin; Pfeifle, Andrea; Jones, Mandy; Hall, Leslie Walter; K Zierler, Brenda

    2016-01-01

    Forty faculty members from eight schools participated in a year-long National Faculty Development Program (NFDP) conducted in 2012-2013, aimed at developing faculty knowledge and skills for interprofessional education (IPE). The NFDP included two live conferences. Between conferences, faculty teams implemented self-selected IPE projects at their home institutions and participated in coaching and peer-support conference calls. This paper describes program outcomes. A mixed methods approach was adopted. Data were gathered through online surveys and semi-structured interviews. The study explored whether faculty were satisfied with the program, believed the program was effective in developing knowledge and skills in designing, implementing, and evaluating IPE, and planned to continue newly-implemented IPE and faculty development (FD). Peer support and networking were two of the greatest perceived benefits. Further, this multi-institutional program appears to have facilitated early organizational change by bringing greater contextual understanding to assumptions made at the local level that in turn could influence hidden curricula and networking. These findings may guide program planning for future FD to support IPE. PMID:26576839

  4. Cooling as a method of finding topological dislocations in lattice models

    International Nuclear Information System (INIS)

    It is well known that the O(3) two-dimensional model has configurations with topological charge Q=1 and action S/sub min/=6.69. Since the exponent characterizing the renormalization-group behavior of this model is 4? such configurations invalidate the standard scaling behavior of the topological susceptibility. The analog exponent for the four-dimensional lattice SU(2) gauge model is 10.77. If there would exist configurations with Q=1 and S<10.77 in this model, they would invalidate the standard scaling behavior of its topological susceptibility. Kremer et al. have calculated the action of different configurations during cooling runs. They report that they do not find any configuration with S<12.7 and Q=1. I show that in the O(3) two-dimensional model cooling runs fail to uncover the well-known configurations with S<8. We conclude that the cooling method is not effective in uncovering the smallest action configurations in the Q=1 sector

  5. A Method to Find Generic Thresholds for Identifying Relevant Physical Activity Events in Sensor Data.

    Science.gov (United States)

    Marschollek, Michael

    2016-01-01

    The increasing use of wearable actimetry devices in cohort studies can provide a deep and objective insight in physical activity (PA) patterns. For reliable and reproducible pattern recognition, and to minimize the influence of specific device characteristics, there is a need for a generic method to identify relevant PA events in sensor data sets on the basis of comprehensive features such as PA duration and intensity. The objectives of this paper are to present a method to identify universal event detection thresholds for such parameters, and to attempt to find stable meta-clusters of PA behaviour. PA events of 5, 10, 20 and 30 min with low, medium and high intensity thresholds found in literature and intensity deciles were computed for a random sample (N?=?100) of the NHANES 2005-06 accelerometer data set (N?=?7457). On the basis of all combinations of the above, activity events were detected, and parameters mean duration, mean intensity and event regularity were computed. Results were clustered using x-Means clustering and visualized for 5-, 10-, 20-, and 30-min events. Stable clustering results are obtained with intensity thresholds up to the 8th decile and for event durations up to 10 min. Two stable meta-clusters were detected: 'irregularly active' (intensity at 52nd percentile) and 'regularly active' (intensity at 42nd percentile). Distinct generic thresholds could be identified and are proposed. They may prove useful for further investigations of similar actimetry data sets, minimising the influence of specific device characteristics. The results also confirm that distinct PA event patterns - including event regularity - can be identified using wearable sensor devices, especially when regarding low-intensity, short-term activities which do not correspond to current PA recommendations. Further research is necessary to evaluate actual associations between sensor-based PA parameters and health outcome. The author identified generic intensity and duration thresholds for analysing objective PA data from wearable devices. This may contribute to further analyses of PA patterns along with their relations with health outcome parameters. PMID:26547849

  6. Centroid-Point of Ranking Fuzzy Numbers and Its Application to Health Related Quality of Life Indicators

    Directory of Open Access Journals (Sweden)

    Lazim Abdullah,

    2010-11-01

    Full Text Available Ranking of fuzzy numbers is not an easy task as fuzzy numbers are represented by possibility distributions and they can overlap with each other. Since it was introduced, various approaches on ranking fuzzy numbers have been proposed. The recent ranking fuzzy numbers proposed by Wang and Li is claimed to be the improved version in ranking. However, the method was never been simplified and tested in real life application. This paper presents a four-step computation ofranking fuzzy numbers and its application in ranking indicatorsof health related quality of life. The four steps algorithm was proposed as to establish ranking and followed by a testimony inhealth related symptoms among elderly. Data in form of linguistic terms were collected from three experts at State of Terengganu Malaysia. Decisions were made based on the centroid-point ( x, y , where the degree of representative location ( x is higher than average height ( y . These points permit to characterize the evaluation behaviour of each indicator. The ranking reflects the problematic level of elderly people. The results show the feasibility of the proposed stepwise computation in real application.

  7. Alternatives for implementing methods for finding agents in a Multi-Agent Systems

    OpenAIRE

    Tucat, Mariano; García, Alejandro Javier

    2006-01-01

    Interaction is an essential characteristic of Multi- Agent Systems (MASs). Agents that are part of a MAS usually interact by exchanging messages accord- ing to some conversation policy. Therefore, the ability to find other agents and exchange messages with them are features that need to be implemented in agents that are part of a MAS. Finding an agent means been aware of it existence and obtaining the information needed to send to it a message. There exists different alternatives of implement...

  8. Shack-Hartmann wavefront sensing with elongated sodium laser beacons: centroiding versus matched filtering

    Science.gov (United States)

    Gilles, Luc; Ellerbroek, Brent

    2006-09-01

    We describe modeling and simulation results for the Thirty Meter Telescope on the degradation of sodium laser guide star Shack-Hartmann wavefront sensor measurement accuracy that will occur due to the spatial structure and temporal variations of the mesospheric sodium layer. By using a contiguous set of lidar measurements of the sodium profile, the performance of a standard centroid and of a more refined noise-optimal matched filter spot position estimation algorithm is analyzed and compared for a nominal mean signal level equal to 1000 photodetected electrons per subaperture per integration time, as a function of subaperture to laser launch telescope distance and CCD pixel readout noise. Both algorithms are compared in terms of their rms spot position estimation error due to noise, their associated wavefront error when implemented on the Thirty Meter Telescope facility adaptive optics system, their linear dynamic range, and their bias when detuned from the current sodium profile.

  9. A Novel Particle Swarm Optimization Algorithm Model with Centroid and its Application

    Directory of Open Access Journals (Sweden)

    Shengli Song

    2009-10-01

    Full Text Available In order to enhance inter-particle cooperation and information sharing capabilities, an improved particle swarm algorithm optimization model is proposed by introducing the centroid of particle swarm in the standard PSO model to improve global optimum efficiency and accuracy of algorithm, then parameter selection guidelines are derived in the convergence of new algorithm. The results of Benchmark function simulation and the material balance computation (MBC in alumina production show the new algorithm, with both a steady convergence and a better stability, not only enhance the local searching efficiency and global searching performance greatly, but also have faster higher precision and convergence speed, and can avoid the premature convergence problem effectively.

  10. Weighted Centroid Algorithm for Estimating Primary User Location: Theoretical Analysis and Distributed Implementation

    CERN Document Server

    Wang, Jun; Han, Yuxing; ?abri?, Danijela

    2010-01-01

    Information about primary user (PU) location is crucial in enabling several key capabilities in dynamic spectrum access networks, including improved spatio-temporal sensing, intelligent location-aware routing, as well as aiding spectrum policy enforcement. Compared to other proposed non-interactive localization algorithms, the weighted centroid localization (WCL) scheme uses only received signal strength information, which makes it simple and robust to variations in the propagation environment. In contrast to prior work, which focused mainly on proposing algorithmic variations and verifying their performance through simulations, in this paper we present the first theoretical framework for WCL performance analysis in terms of its localization error distribution parameterized by node density, node placement, shadowing variance and correlation distance. Using this analysis, we quantify the robustness of WCL to various physical conditions and provide guidelines, such as node placement, for practical deployment of...

  11. Path integral centroid molecular dynamics simulations of semiinfinite slab and bulk liquid of para-hydrogen

    Energy Technology Data Exchange (ETDEWEB)

    Kinugawa, Kenichi [Nara Women`s Univ., Nara (Japan). Dept. of Chemistry

    1998-10-01

    It has been unsuccessful to solve a set of time-dependent Schroedinger equations numerically for many-body quantum systems which involve, e.g., a number of hydrogen molecules, protons, and excess electrons at a low temperature, where quantum effect evidently appears. This undesirable situation is fatal for the investigation of real low-temperature chemical systems because they are essentially composed of many quantum degrees of freedom. However, if we use a new technique called `path integral centroid molecular dynamics (CMD) simulation` proposed by Cao and Voth in 1994, the real-time semi-classical dynamics of many degrees of freedom can be computed by utilizing the techniques already developed in the traditional classical molecular dynamics (MD) simulations. Therefore, the CMD simulation is expected to be very powerful tool for the quantum dynamics studies or real substances. (J.P.N.)

  12. The centroidal algorithm in molecular similarity and diversity calculations on confidential datasets.

    Science.gov (United States)

    Trepalin, Sergey; Osadchiy, Nikolay

    2005-01-01

    Chemical structure provides exhaustive description of a compound, but it is often proprietary and thus an impediment in the exchange of information. For example, structure disclosure is often needed for the selection of most similar or dissimilar compounds. Authors propose a centroidal algorithm based on structural fragments (screens) that can be efficiently used for the similarity and diversity selections without disclosing structures from the reference set. For an increased security purposes, authors recommend that such set contains at least some tens of structures. Analysis of reverse engineering feasibility showed that the problem difficulty grows with decrease of the screen's radius. The algorithm is illustrated with concrete calculations on known steroidal, quinoline, and quinazoline drugs. We also investigate a problem of scaffold identification in combinatorial library dataset. The results show that relatively small screens of radius equal to 2 bond lengths perform well in the similarity sorting, while radius 4 screens yield better results in diversity sorting. The software implementation of the algorithm taking SDF file with a reference set generates screens of various radii which are subsequently used for the similarity and diversity sorting of external SDFs. Since the reverse engineering of the reference set molecules from their screens has the same difficulty as the RSA asymmetric encryption algorithm, generated screens can be stored openly without further encryption. This approach ensures an end user transfers only a set of structural fragments and no other data. Like other algorithms of encryption, the centroid algorithm cannot give 100% guarantee of protecting a chemical structure from dataset, but probability of initial structure identification is very small-order of 10(-40) in typical cases. PMID:16331405

  13. The expanded FindCore method for identification of a core atom set for assessment of protein structure prediction.

    Science.gov (United States)

    Snyder, David A; Grullon, Jennifer; Huang, Yuanpeng J; Tejero, Roberto; Montelione, Gaetano T

    2014-02-01

    Maximizing the scientific impact of NMR-based structure determination requires robust and statistically sound methods for assessing the precision of NMR-derived structures. In particular, a method to define a core atom set for calculating superimpositions and validating structure predictions is critical to the use of NMR-derived structures as targets in the CASP competition. FindCore (Snyder and Montelione, Proteins 2005;59:673-686) is a superimposition independent method for identifying a core atom set and partitioning that set into domains. However, as FindCore optimizes superimposition by sensitively excluding not-well-defined atoms, the FindCore core may not comprise all atoms suitable for use in certain applications of NMR structures, including the CASP assessment process. Adapting the FindCore approach to assess predicted models against experimental NMR structures in CASP10 required modification of the FindCore method. This paper describes conventions and a standard protocol to calculate an "Expanded FindCore" atom set suitable for validation and application in biological and biophysical contexts. A key application of the Expanded FindCore method is to identify a core set of atoms in the experimental NMR structure for which it makes sense to validate predicted protein structure models. We demonstrate the application of this Expanded FindCore method in characterizing well-defined regions of 18 NMR-derived CASP10 target structures. The Expanded FindCore protocol defines "expanded core atom sets" that match an expert's intuition of which parts of the structure are sufficiently well defined to use in assessing CASP model predictions. We also illustrate the impact of this analysis on the CASP GDT assessment scores. PMID:24327305

  14. Finding the Social Value of Forests Through Stated Preference Methods: A Mediterranean Forest Valuation Exercise

    Directory of Open Access Journals (Sweden)

    Pere Riera

    2004-06-01

    Full Text Available There are several methods to estimate the social value of forests or forest attributes, the most widely used being the stated preference methods. This paper illustrates the use of such methods to estimate some recreational functions of Mediterranean forests, as well as CO2 sequestration and soil erosion prevention. It also compares the results from a contingent ranking and a choice experiment method application.

  15. Achete grilles et methodes pour recherche d'idees sans peine (Buy Grids and Painless Methods for Finding Ideas).

    Science.gov (United States)

    Yaiche, Francis

    1986-01-01

    Proposes tools and methods for teachers and students to use in the classroom to organize and stimulate ideas, imagination, memory, improvisation, and writing. Sample outlines and grids serve as methods for helping learners understand specific concepts. (MSE)

  16. A simple method for finding the scattering coefficients of quantum graphs

    Science.gov (United States)

    Cottrell, Seth S.

    2015-09-01

    Quantum walks are roughly analogous to classical random walks, and similar to classical walks they have been used to find new (quantum) algorithms. When studying the behavior of large graphs or combinations of graphs, it is useful to find the response of a subgraph to signals of different frequencies. In doing so, we can replace an entire subgraph with a single vertex with variable scattering coefficients. In this paper, a simple technique for quickly finding the scattering coefficients of any discrete-time quantum graph will be presented. These scattering coefficients can be expressed entirely in terms of the characteristic polynomial of the graph's time step operator. This is a marked improvement over previous techniques which have traditionally required finding eigenstates for a given eigenvalue, which is far more computationally costly. With the scattering coefficients we can easily derive the "impulse response" which is the key to predicting the response of a graph to any signal. This gives us a powerful set of tools for rapidly understanding the behavior of graphs or for reducing a large graph into its constituent subgraphs regardless of how they are connected.

  17. Moving Domestic Robotics Control Method Based on Creating and Sharing Maps with Shortest Path Findings and Obstacle Avoidance

    Directory of Open Access Journals (Sweden)

    Kohei Arai

    2013-02-01

    Full Text Available Control method for moving robotics in closed areas based on creation and sharing maps through shortest path findings and obstacle avoidance is proposed. Through simulation study, a validity of the proposed method is confirmed. Furthermore, the effect of map sharing among robotics is also confirmed together with obstacle avoidance with cameras and ultrasonic sensors.

  18. Bayesian data augmentation methods for the synthesis of qualitative and quantitative research findings

    OpenAIRE

    Crandell, Jamie L.; Voils, Corrine I; Chang, Yunkyung; Sandelowski, Margarete

    2011-01-01

    The possible utility of Bayesian methods for the synthesis of qualitative and quantitative research has been repeatedly suggested but insufficiently investigated. In this project, we developed and used a Bayesian method for synthesis, with the goal of identifying factors that influence adherence to HIV medication regimens. We investigated the effect of 10 factors on adherence. Recognizing that not all factors were examined in all studies, we considered standard methods for dealing with missin...

  19. METHOD FOR ESTIMATING METHANE EMISSIONS FROM UNDERGROUND COAL MINES: PRELIMINARY FINDINGS

    Science.gov (United States)

    The paper discusses the development of an improved method for estimating global methane (CH4) emissions from underground coal mining. ince emissions data presently not available for surface mines, this method is currently restricted to underground mines. The EPA has embarked on a...

  20. An MLE method for finding LKB NTCP model parameters using Monte Carlo uncertainty estimates

    International Nuclear Information System (INIS)

    The aims of this work were to establish a program to fit NTCP models to clinical data with multiple toxicity endpoints, to test the method using a realistic test dataset, to compare three methods for estimating confidence intervals for the fitted parameters and to characterise the speed and performance of the program.

  1. The functional variable method for finding exact solutions of some nonlinear time-fractional differential equations

    Indian Academy of Sciences (India)

    Wenjun Liu; Kewang Chen

    2013-09-01

    In this paper, we implemented the functional variable method and the modified Riemann–Liouville derivative for the exact solitary wave solutions and periodic wave solutions of the time-fractional Klein–Gordon equation, and the time-fractional Hirota–Satsuma coupled KdV system. This method is extremely simple but effective for handling nonlinear time-fractional differential equations.

  2. Towards understanding household-level forest reliance in Cambodia - study sites, methods, and preliminary findings

    DEFF Research Database (Denmark)

    Ra, Koy; Pichdara, Lonn; Dararath, Yem; Jiao, Xi; Smith-Hall, Carsten

    There is growing international interest in the role of forests in poverty prevention and reduction. In consequence, this broad area of investigation has been subject to increased research; one major international research project is that facilitated by the Poverty Environment Network (PEN). This ...... project covers a large number of sites in 26 countries throughout the tropics. The present report contains contextual details, methodological information and preliminary findings for the PEN sites in Cambodia....

  3. Mechanical form-Finding of the Timber Fabric Structures with Dynamic Relaxation Method

    OpenAIRE

    Nabaei, Seyed Sina; Baverel, Olivier; Weinand, Yves

    2013-01-01

    Timber Fabric structures (TFS) initiate from a correspondence between textile principles and recent industrial developments in producing cross laminated timber panels. Several individual timber strips are interlaced according to a pattern and result in an innovative space structure. The obtained three-dimensional geometry can be regarded as the relaxed configuration of deformed panels under the imposed boundary conditions. We herein propose a form-finding procedure, which reproduces this def...

  4. The Expanded FindCore Method for Identification of a Core Atom Set for Assessment of Protein Structure Prediction

    OpenAIRE

    Snyder, David A.; Grullon, Jennifer; Huang, Yuanpeng J.; Tejero, Roberto; Montelione, Gaetano T.

    2014-01-01

    Maximizing the scientific impact of NMR-based structure determination requires robust and statistically sound methods for assessing the precision of NMR-derived structures. In particular, a method to define a core atom set for calculating superimpositions and validating structure predictions is critical to the use of NMR-derived structures as targets in the CASP competition. FindCore (D.A. Snyder and G.T. Montelione PROTEINS 2005;59:673–686) is a superimposition independent method for identif...

  5. A comparison of three clustering methods for finding subgroups in MRI, SMS or clinical data

    DEFF Research Database (Denmark)

    Kent, Peter; Jensen, Rikke K; Kongsted, Alice

    2014-01-01

    BACKGROUND: There are various methodological approaches to identifying clinically important subgroups and one method is to identify clusters of characteristics that differentiate people in cross-sectional and/or longitudinal data using Cluster Analysis (CA) or Latent Class Analysis (LCA). There is......, Latent Gold LCA and SNOB LCA). METHODS: The performance of these three methods was compared: (i) quantitatively using the number of subgroups detected, the classification probability of individuals into subgroups, the reproducibility of results, and (ii) qualitatively using subjective judgments about...... known subgroups and correctly classify individuals into those subgroups. CONCLUSIONS: Our subjective judgement was that Latent Gold offered the best balance of sensitivity to subgroups, ease of use and presentation of results with these datasets but we recognise that different clustering methods may...

  6. A comparative method for finding and folding RNA secondary structures within protein-coding regions

    DEFF Research Database (Denmark)

    Pedersen, Jakob Skou; Meyer, Irmtraud Margret; Forsberg, Roald; Simmonds, Peter; Hein, Jotun

    2004-01-01

    Existing computational methods for RNA secondary-structure prediction tacitly assume RNA to only encode functional RNA structures. However, experimental studies have revealed that some RNA sequences, e.g. compact viral genomes, can simultaneously encode functional RNA structures as well as proteins, and evidence is accumulating that this phenomenon may also be found in Eukaryotes. We here present the first comparative method, called RNA-DECODER, which explicitly takes the known protein-coding co...

  7. A psychoacoustic method to find the perceptual cues of stop consonants in natural speech

    OpenAIRE

    Li, Feipeng; Menon, Anjali; Allen, Jont B.

    2010-01-01

    Synthetic speech has been widely used in the study of speech cues. A serious disadvantage of this method is that it requires prior knowledge about the cues to be identified in order to synthesize the speech. Incomplete or inaccurate hypotheses about the cues often lead to speech sounds of low quality. In this research a psychoacoustic method, named three-dimensional deep search (3DDS), is developed to explore the perceptual cues of stop consonants from naturally produced speech. For a given s...

  8. A Novel Systematic Error Compensation Algorithm Based on Least Squares Support Vector Regression for Star Sensor Image Centroid Estimation

    Directory of Open Access Journals (Sweden)

    Jingyan Song

    2011-07-01

    Full Text Available The star centroid estimation is the most important operation, which directly affects the precision of attitude determination for star sensors. This paper presents a theoretical study of the systematic error introduced by the star centroid estimation algorithm. The systematic error is analyzed through a frequency domain approach and numerical simulations. It is shown that the systematic error consists of the approximation error and truncation error which resulted from the discretization approximation and sampling window limitations, respectively. A criterion for choosing the size of the sampling window to reduce the truncation error is given in this paper. The systematic error can be evaluated as a function of the actual star centroid positions under different Gaussian widths of star intensity distribution. In order to eliminate the systematic error, a novel compensation algorithm based on the least squares support vector regression (LSSVR with Radial Basis Function (RBF kernel is proposed. Simulation results show that when the compensation algorithm is applied to the 5-pixel star sampling window, the accuracy of star centroid estimation is improved from 0.06 to 6 × 10?5 pixels.

  9. A numerical method for finding sign-changing solutions of superlinear Dirichlet problems

    Energy Technology Data Exchange (ETDEWEB)

    Neuberger, J.M.

    1996-12-31

    In a recent result it was shown via a variational argument that a class of superlinear elliptic boundary value problems has at least three nontrivial solutions, a pair of one sign and one which sign changes exactly once. These three and all other nontrivial solutions are saddle points of an action functional, and are characterized as local minima of that functional restricted to a codimension one submanifold of the Hilbert space H-0-1-2, or an appropriate higher codimension subset of that manifold. In this paper, we present a numerical Sobolev steepest descent algorithm for finding these three solutions.

  10. Kinetic and thermodynamic parameters of biodiesel oxidation with synthetic antioxidants: simplex centroid mixture design

    Scientific Electronic Library Online (English)

    Dionisio, Borsato; Diego, Galvan; Jaqueline L., Pereira; Juliane R., Orives; Karina G., Angilelli; Rodolfo L., Coppo.

    2014-11-01

    Full Text Available A influência da temperatura sobre a oxidação de biodiesel foi avaliada pelos parâmetros cinéticos e termodinâmicos do biocombustível de óleo de soja e gordura suína com antioxidantes sintéticos: 3-terc-butil-4-hidroxianisol (BHA), 3,5-di-terc-butil-hidroxitolueno (BHT), 2-terc-butil-hidroquinona (TB [...] HQ) e galato de propila (PG), de acordo com delineamento de mistura simplex-centróide. Os parâmetros cinéticos foram determinados considerando-se reação de primeira ordem e aplicando a equação de Arrhenius. A adição de antioxidantes promoveu o aumento da energia de ativação (Ea), sendo TBHQ e PG os mais eficientes, apresentando efeito sinérgico. BHT e BHA foram os menos eficientes, assim como suas misturas. Os parâmetros termodinâmicos de ativação, avaliados pela equação de Eyring, não indicaram processos espontâneos (?G‡ > 0) com valores de ?H‡ positivos, e ?S‡ positivos e negativos. O delineamento simplex-centróide indicou valor otimizado de 174,46 kJ mol-1 para a mistura contendo 33,33 e 66,67% de TBHQ e PG, respectivamente. Abstract in english Temperature's influence on biodiesel oxidation was evaluated by kinetic and thermodynamic data in biofuel from soybean oil and lard with synthetic antioxidants: butylatedhydroxyanisol (BHA), butylatedhydroxytoluene (BHT), tert-butylhydroquinone (TBHQ), and propylgallate (PG) by simplex centroid mixt [...] ure design. The kinetic parameters ware obtained by Arrhenius equation and showed that addition of antioxidants in all tests increased activation energy (Ea) and that TBHQ and PG were more efficient and presented synergistic effect. BHT and BHA were the least efficient, as well as their mixtures. The thermodynamic activation parameters of the reactions, evaluated by the Eyring equation and based on the theory of the activated complex (ACT), indicated no spontaneous processes (?G‡ > 0) with positive ?H‡ values and positive and negative ?S‡ values. The application of simplex centroid mixture design, using Ea as response, showed the optimised value of 174.46 kJ mol-1 for a mixture containing 33.33 and 66.67% of TBHQ and PG, respectively.

  11. Finding a needle in a haystack: toward a psychologically informed method for aviation security screening.

    Science.gov (United States)

    Ormerod, Thomas C; Dando, Coral J

    2015-02-01

    Current aviation security systems identify behavioral indicators of deception to assess risks to flights, but they lack a strong psychological basis or empirical validation. We present a new method that tests the veracity of passenger accounts. In an in vivo double-blind randomized-control trial conducted in international airports, security agents detected 66% of deceptive passengers using the veracity test method compared with less than 5% using behavioral indicator recognition. As well as revealing advantages of veracity testing over behavioral indicator identification, the study provides the highest levels to date of deception detection in a realistic setting where the known base rate of deceptive individuals is low. PMID:25365531

  12. Method for finding the critical temperature of the island in a SET structure

    Energy Technology Data Exchange (ETDEWEB)

    Toppari, J J; Kuehn, T; Halvari, A P [NanoScience Center, Department of Physics, University of Jyvaskyla, PO Box 35 (YN), FIN-40014 University of Jyvaskyla (Finland); Paraoanu, G S [Low Temperature Laboratory, Helsinki University of Technology, PO Box 5100, FIN-02015 TKK (Finland)], E-mail: paraoanu@cc.hut.fi

    2009-02-01

    We present a method to measure the critical temperature of the island of a superconducting single electron transistor. The method is based on a sharp change in the slope of the zero-bias conductance as a function of temperature. We have used this method to determine the superconducting phase transition temperature of the Nb island of an superconducting single electron transistor with Al leads. We obtain T{sub c}{sup Nb} as high as 8.5 K and gap energies up to {delta}Nb {approx_equal} 1.45 meV. By looking at the zero bias conductance as a function of magnetic field instead of temperature, also the critical field of the island can be determined. Using the orthodox theory, we have performed extensive numerical simulations of charge transport properties in the SET at temperatures comparable to the gap, which match very well the data, therefore providing a solid theoretical basis for our method. PACS: 73.23.Hk,73.40.Gk,74.50.+r.

  13. The Dynamics of Poverty in the United States: A Review of Data, Methods, and Findings

    Science.gov (United States)

    Cellini, Stephanie Riegg; McKernan, Signe-Mary; Ratcliffe, Caroline

    2008-01-01

    This paper reviews the literature on poverty dynamics in the U.S. It surveys the most prevalent data, theories, and methods used to answer three key questions: How likely are people to enter, exit, and reenter poverty? How long do people remain in poverty? And what events are associated with entering and exiting poverty? The paper then analyzes…

  14. A Simple Method to Find out when an Ordinary Differential Equation Is Separable

    Science.gov (United States)

    Cid, Jose Angel

    2009-01-01

    We present an alternative method to that of Scott (D. Scott, "When is an ordinary differential equation separable?", "Amer. Math. Monthly" 92 (1985), pp. 422-423) to teach the students how to discover whether a differential equation y[prime] = f(x,y) is separable or not when the nonlinearity f(x, y) is not explicitly factorized. Our approach is…

  15. A few basic considerations on the method of finding the law - Einige Grundüberlegungen zur Methode der Rechtsfindung

    Directory of Open Access Journals (Sweden)

    Jochen Bung

    2009-09-01

    Full Text Available The contribution attempts to illustrate why it is appropriate to speak of finding, re-cognising and application, or applying, of the law. Reservations have been articulated about this use of language as a consequence of ontologically sceptical assumptions, which raise doubts as to the level of reality contained in these terms. “Legal ontology” is used as a knock-down argument in certain pointed aspects of this scepticism. However, there is no reason to do so.Der Beitrag versucht zu verdeutlichen, warum es in Ordnung ist, von Rechtsfindung, Rechtserkenntnis und Rechtsanwendung zu sprechen. Bedenken gegenüber diesem Sprachgebrauch sind in der Folge ontologieskeptischer Annahmen artikuliert worden, die Zweifel am Realitätsgehalt der genannten Begriffe anmelden. „Rechtsontologie” wird in bestimmten Pointierungen dieser Skepsis als Knock-down-Argument eingesetzt. Dafür gibt es aber keinen Grund.

  16. An alignment-free method to find and visualise rearrangements between pairs of DNA sequences.

    Science.gov (United States)

    Pratas, Diogo; Silva, Raquel M; Pinho, Armando J; Ferreira, Paulo J S G

    2015-01-01

    Species evolution is indirectly registered in their genomic structure. The emergence and advances in sequencing technology provided a way to access genome information, namely to identify and study evolutionary macro-events, as well as chromosome alterations for clinical purposes. This paper describes a completely alignment-free computational method, based on a blind unsupervised approach, to detect large-scale and small-scale genomic rearrangements between pairs of DNA sequences. To illustrate the power and usefulness of the method we give complete chromosomal information maps for the pairs human-chimpanzee and human-orangutan. The tool by means of which these results were obtained has been made publicly available and is described in detail. PMID:25984837

  17. Optimization of Phenolic Antioxidant Extraction from Wuweizi (Schisandra chinensis Pulp Using Random-Centroid Optimazation Methodology

    Directory of Open Access Journals (Sweden)

    Xiong Yu

    2011-09-01

    Full Text Available The extraction optimization and composition analysis of polyphenols in the fresh pulp of Wuweizi (Schisandra chinensis have been investigated in this study. The extraction process of polyphenols from Wuweizi pulp was optimized using Random-Centroid Optimization (RCO methodology. Six factors including liquid and solid ratio, ethanol concentration, pH, temperature, heating time and extraction times, and three extraction targets of polyphenol content, antioxidant activity and extract yield were considered in the RCO program. Three sets of optimum proposed factor values were obtained corresponding to three extraction targets respectively. The set of optimum proposed factor values for polyphenol extraction given was chosen in further experiments as following: liquid and solid ratio (v/w 8, ethanol 67.3% (v/v, initial pH 1.75, temperature 55 °C for 4 h and extraction repeated for 4 times. The Wuweizi polyphenol extract (WPE was obtained with a yield of 16.37 mg/g and composition of polyphenols 1.847 mg/g, anthocyanins 0.179 mg/g, sugar 9.573 mg/g and protein 0.327 mg/g. The WPE demonstrated high scavenging activities against DPPH radicals.

  18. Spot centroid sensitivity to angle of intensity on image detector with lenslet array.

    Science.gov (United States)

    Hui, Mei; Zhou, Ping; Su, Peng; Zhao, Zhu

    2015-05-20

    Lenslet array was introduced to an image detector to compensate for low sensitivity. These lenses deviate the light from different incident angles and potentially introduce errors when subpixel accuracy is needed. We investigated the spot centroid position because the angle of incidence changes on a Kodak KAI-16000 image detector with lenslet array. In our experiment, we noticed that there is a cubic dependency on the incident angle. The experimental results show that dependence on the angle of incidence is related to the lenslet array in the Kodak detector used for the pentaprism test. This situation caused an error in spherical aberration on the test surface after integration. The magnitude of the cubic component at incident angle of 14° (equivalent to F/2) is 11.6 μm, which corresponds to a 48 nm rms spherical aberration for the test surface and brings the scanning pentaprism test closer to the principal test while there is a 56 nm rms discrepancy. The discrepancy in spherical aberration between the two tests reduced to 8 nm after this calibration. It also showed the contrast measurement results for the Kodak detector and PointGrey detector. We performed experiments with two different detectors to quantify this effect. PMID:26192498

  19. Collective centroid oscillations as an emittance preservation diagnostic in linear collider linacs

    International Nuclear Information System (INIS)

    Transverse bunch centroid oscillations, induced at operating beam currents at which transverse wakefields are substantial, and observed at Beam Position Monitors, are sensitive to the actual magnetic focusing, energy gain, and rf phase profiles in a linac, and are insensitive to misalignments and jitter sources. In the pulse stealing set-up implemented at the SLC, they thus allow the frequent monitoring of the stability of the in-place emittance growth inhibiting or mitigating measures--primarily the energy scaled magnetic lattice and the rf phases necessary for BNS damping--independent of the actual emittance growth as driven by misalignments and jitter. The authors have developed a physically based analysis technique to meaningfully reduce the data. Oscillation beta-beating is a primary indicator of beam energy errors; shifts in the invariant amplitude reflect differential internal motion along the longitudinally extended bunch and thus are a sensitive indicator of the real rf phases in the machine; shifts in betatron phase advance contain corroborative information sensitive to both effects

  20. Power centroid radar and its rise from the universal cybernetics duality

    Science.gov (United States)

    Feria, Erlan H.

    2014-05-01

    Power centroid radar (PC-Radar) is a fast and powerful adaptive radar scheme that naturally surfaced from the recent discovery of the time-dual for information theory which has been named "latency theory." Latency theory itself was born from the universal cybernetics duality (UC-Duality), first identified in the late 1970s, that has also delivered a time dual for thermodynamics that has been named "lingerdynamics" and anchors an emerging lifespan theory for biological systems. In this paper the rise of PC-Radar from the UC-Duality is described. The development of PC-Radar, US patented, started with Defense Advanced Research Projects Agency (DARPA) funded research on knowledge-aided (KA) adaptive radar of the last decade. The outstanding signal to interference plus noise ratio (SINR) performance of PC-Radar under severely taxing environmental disturbances will be established. More specifically, it will be seen that the SINR performance of PC-Radar, either KA or knowledgeunaided (KU), approximates that of an optimum KA radar scheme. The explanation for this remarkable result is that PC-Radar inherently arises from the UC-Duality, which advances a "first principles" duality guidance theory for the derivation of synergistic storage-space/computational-time compression solutions. Real-world synthetic aperture radar (SAR) images will be used as prior-knowledge to illustrate these results.

  1. The relationship between vocational interests and intelligence: Do findings generalize across different assessment methods?

    OpenAIRE

    René T. Proyer

    2007-01-01

    The aim of this study was to further explore the relationship between vocational interests and intelligence. There is some evidence in literature on the stable relationships between vocational interests and intelligence (cf. Ackerman & Heggestad, 1997). It should be noted that the majority of the previous studies have only used questionnaires for the assessment of vocational interests. Thus, it is of interest whether the results are also stable when different assessment methods are used. Ther...

  2. LGA: a method for finding 3D similarities in protein structures

    OpenAIRE

    Zemla, Adam

    2003-01-01

    We present the LGA (Local-Global Alignment) method, designed to facilitate the comparison of protein structures or fragments of protein structures in sequence dependent and sequence independent modes. The LGA structure alignment program is available as an online service at http://PredictionCenter.llnl.gov/local/lga. Data generated by LGA can be successfully used in a scoring function to rank the level of similarity between two structures and to allow structure classification when many protein...

  3. Study methods, recruitment, socio-demographic findings and demographic representativeness in the OPPERA study

    OpenAIRE

    Slade, Gary D.; Bair, Eric; By, Kunthel; Mulkey, Flora; Baraian, Cristina; Rothwell, Rebecca; Reynolds, Maria; Miller, Vanessa; Gonzalez, Yoly; Gordon, Sharon; Ribeiro-Dasilva, Margarete; Lim, Pei Feng; Greenspan, Joel D.; Dubner, Ron; Fillingim, Roger B

    2011-01-01

    This paper describes methods used in the project “Orofacial Pain Prospective Evaluation and Risk Assessment” (OPPERA) and evaluates socio-demographic characteristics associated with temporomandibular disorders (TMD) in the OPPERA case-control study. Representativeness was investigated by comparing socio-demographic profiles of OPPERA participants with population census profiles of counties near study sites and by comparing age- and gender-associations with TMD in OPPERA and the 2007-09 US Nat...

  4. An Intercomparison of Methods for Finding Coupled Patterns in Climate Data.

    Science.gov (United States)

    Bretherton, Christopher S.; Smith, Catherine; Wallace, John M.

    1992-06-01

    This paper introduces a conceptual framework for comparing methods that isolate important coupled modes of variability between time series of two fields. Four specific methods are compared: principal component analysis with the fields combined (CPCA), canonical correlation analysis (CCA) and a variant of CCA proposed by Barnett and Preisendorfer (BP), principal component analysis of one single field followed by correlation of its component amplitudes with the second field (SFPCA), and singular value decomposition of the covariance matrix between the two fields (SVD). SVD and CPCA are easier to implement than BP, and do not involve user-chosen parameters. All methods are applied to a simple but geophysically relevant model system and their ability to detect a coupled signal is compared as parameters such as the number of points in each field, the number of samples in the time domain, and the signal-to-noise ratio are varied.In datasets involving geophysical fields, the number of sampling times may not be much larger than the number of observing locations or grid points for each field. In a model system with these characteristics, CPCA usually extracted the coupled pattern somewhat more accurately than SVD, BP, and SFPCA, since the patterns it yielded exhibit smaller sampling variability; SVD and BP gave quite similar results; and CCA was uncompetitive due to a high sampling variability unless the coupled signal was highly localized. The coupled modes derived from CPCA and SFPCA exhibit an undesirable mean bias toward the leading EOFs of the individual fields; in fact, for small signal-to-noise ratios these methods may identify a coupled signal that is similar to a dominant EOF of one of the fields but is completely orthogonal to the true coupled signal within that field. For longer time series, or in situations where the coupled signal does not resemble the EOFs of the individual fields, these biases can make SVD and BP substantially superior to CPCA.

  5. Exploring Community Gardens in a Health Disparate Population: Findings from a Mixed Methods Pilot Study

    OpenAIRE

    Zanko, Ashley; Price, Bryan; Bonner, Jennifer; Hill, Jennie L; Zoellner, Jamie M

    2012-01-01

    Background: Despite recommendations, there have been few efforts to apply the community-based participatory research (CBPR) approach in the development, implementation, and evaluation of community gardens. Objectives: As guided by the CBPR approach and grounded in a social-ecological model and behavioral theory, the purpose of this mixed methods study was to understand opinions and interests in developing and implementing a community garden and to understand factors impacting fruit, vegetable...

  6. THE STATISTICAL METHOD FOR FINDING THE RESPONSE FOR N RANDOM EXCITATION OF THE INVERTED PENDULUM

    OpenAIRE

    Marinic? STAN; Petre STAN

    2013-01-01

    We present a method for estimating the power spectral density of the stationary response of oscillatorwith a nonlinear restoring force under external stochastic wide-band excitation. An equivalent linear system isderived, from which the power spectral density is deduced. We consider an inverted pendulum suspendedsubjected to white noise excitation with a random number n random excitations simultaneously applied. Themethod will be briefly discussed in the following sections

  7. THE STATISTICAL METHOD FOR FINDING THE RESPONSE FOR N RANDOM EXCITATION OF THE INVERTED PENDULUM

    Directory of Open Access Journals (Sweden)

    Marinic? STAN

    2013-05-01

    Full Text Available We present a method for estimating the power spectral density of the stationary response of oscillatorwith a nonlinear restoring force under external stochastic wide-band excitation. An equivalent linear system isderived, from which the power spectral density is deduced. We consider an inverted pendulum suspendedsubjected to white noise excitation with a random number n random excitations simultaneously applied. Themethod will be briefly discussed in the following sections

  8. Healthy Bread Initiative: Methods, Findings, and Theories—Isfahan Healthy Heart Program

    OpenAIRE

    Talaei, Mohammad; Mohammadifard, Noushin; Khaje, Mohammad-Reza; Sarrafzadegan, Nizal; Sajjadi, Firoozeh; Alikhasi, Hasan; Maghroun, Maryam; Iraji, Farhad; Ehteshami, Shahram

    2013-01-01

    The scientific evidences show that the content, baking methods, and types of bread can make health impacts. Bread, as a major part of Iranian diet, demonstrates a significant potential to be targeted as health promotion subject. Healthy Food for Healthy Communities (HFHC) was a project of Isfahan Healthy Heart Program (IHHP), consisting of a wide variety of strategies, like Healthy Bread (HB) Initiative. The HB Initiative was designed to improve the behaviour of both producers and consumers, ...

  9. Paediatric cardiac CT examinations: impact of the iterative reconstruction method ASIR on image quality - preliminary findings

    International Nuclear Information System (INIS)

    Radiation dose exposure is of particular concern in children due to the possible harmful effects of ionizing radiation. The adaptive statistical iterative reconstruction (ASIR) method is a promising new technique that reduces image noise and produces better overall image quality compared with routine-dose contrast-enhanced methods. To assess the benefits of ASIR on the diagnostic image quality in paediatric cardiac CT examinations. Four paediatric radiologists based at two major hospitals evaluated ten low-dose paediatric cardiac examinations (80 kVp, CTDIvol 4.8-7.9 mGy, DLP 37.1-178.9 mGy.cm). The average age of the cohort studied was 2.6 years (range 1 day to 7 years). Acquisitions were performed on a 64-MDCT scanner. All images were reconstructed at various ASIR percentages (0-100%). For each examination, radiologists scored 19 anatomical structures using the relative visual grading analysis method. To estimate the potential for dose reduction, acquisitions were also performed on a Catphan phantom and a paediatric phantom. The best image quality for all clinical images was obtained with 20% and 40% ASIR (p < 0.001) whereas with ASIR above 50%, image quality significantly decreased (p < 0.001). With 100% ASIR, a strong noise-free appearance of the structures reduced image conspicuity. A potential for dose reduction of about 36% is predicted for a 2- to 3-year-old child when using 40% ASIR rather than the standard filtered back-projection method. Reconstruction including 20% to 40% ASIR slightly improved the conspicuity of various paediatric cardiac structures in newborns and children with respect to conventional reconstruction (filtered back-projection) alone. (orig.)

  10. The use of multicriteria decision making methods to find the environmental costs of hydropower development alternatives

    International Nuclear Information System (INIS)

    The conference paper deals with a decision support system (DSS) developed to find the costs of environmental goods. The system is based on multicriteria decision making and uses pairwise comparisons of two and two criteria. The criteria weights are calculated with linear regression. When one criterion is monetary, all criteria weights can be expressed in monetary units when the weights are known. The DSS has been tested on a hydropower project in the area of Sauda in Norway. To represent the decision makers, three panels each consisting of three persons were formed. The persons were selected from governmental agencies, the developers, the local environmental administration and a local politician. The DSS worked well with the panels. One problem was that impacts of hydropower projects are very site specific and also hard to quantify. Therefore, a considerable amount of time was used in creating a cognitive understanding of the issues involved and how they were represented by quantitative criteria. Some had also difficulties in accepting the principle of expressing environmental goods in monetary units. The results so far are preliminary. This research work is part of the Norwegian research programme Energy, Environment and Development. 3 refs., 4 figs., 2 tabs

  11. Finding a method to analyze qualitative data: using a study of conceptual learning.

    Science.gov (United States)

    McMillan, Wendy J

    2009-01-01

    There is increasing awareness in the health sciences of the potential of qualitative research to address questions that quantitative research cannot satisfactorily answer. While a growing number of studies in health sciences and health sciences education discuss the value of such research or describe the methodology and data collection processes, few detail how analysis was carried out. Reliability and validity of findings from qualitative research depend on the quality of data management, retrieval, and interpretation or identification of meaning. The robustness of data analysis is therefore an important factor in the rigor of qualitative research. This article uses a study of dental students' conceptual learning to illustrate strategies that ensure rigor in qualitative analysis. Factors that informed the decisions regarding analysis are discussed in detail. The use of both grounded theory and literature is discussed. The role that deductive and inductive reasoning played in the analysis is outlined. A brief section illustrates the kinds of conclusions that can be made about conceptual learning when qualitative data are rigorously analyzed. Finally, potential shortcomings in the study and alternatives or additional mechanisms for ensuring validity and reliability of analysis are discussed. PMID:19126767

  12. A Vision based Geometrical Method to find Fingers Positions in Real Time Hand Gesture Recognition

    OpenAIRE

    Ankit Chaudhary; Raheja, Jagdish L.; Shekhar Raheja

    2012-01-01

    A novel method to calculate the bended finger’s angle has presented here which could be used to control the electro-mechanical robotic hand. It is assumed that the robotic hand has the human hand like joints and same number of degree of freedom as human hand. In many applications an equipment like human hand is needed, to do the same kind of operation like human do. These days it is easy to make the electro-mechanical robotic hand which has five fingers and same joint but it is not easi...

  13. ALGORITHM FOR FINDING EFFECTIVE FORMS AND METHODS OF TRADE ACTIVATION AND OPTIMIZATION OF FOREIGN UKRAINE

    Directory of Open Access Journals (Sweden)

    ?.?. ??????

    2011-12-01

    Full Text Available  The Fundamental and applied problems of activation and optimization of foreign economic activity is choice of effective forms and methods of realization of external economic point-of-sale operations. In this context, on the basis of the Ukrainian legislation and economic literature, it is formulated and generalized them teoretiko-methodological essence, and also separate features which can serve as the economic instruments of activation and optimization of foreign economic activity of Ukraine are marked. Generalized methodological properties of algorithms and the schematic algorithm of search of economic instruments of activation and optimization of foreign economic activity of Ukraine is developed.

  14. A Vision based Geometrical Method to find Fingers Positions in Real Time Hand Gesture Recognition

    Directory of Open Access Journals (Sweden)

    Ankit Chaudhary

    2012-04-01

    Full Text Available A novel method to calculate the bended finger’s angle has presented here which could be used to control the electro-mechanical robotic hand. It is assumed that the robotic hand has the human hand like joints and same number of degree of freedom as human hand. In many applications an equipment like human hand is needed, to do the same kind of operation like human do. These days it is easy to make the electro-mechanical robotic hand which has five fingers and same joint but it is not easily controllable as the human hand for accurate work. In our method the hand gesture will be interpreted for controlling the robotic hand. The angles for all the fingers will be calculated and that could be further passed to the robotic hand for controlling its finger. User would perform gesture according to the action as he wants to be done by robotic hand. Here finger positions are detected using geometric modeling of hand in the extracted image Region of interest cropping from the image made the algorithm faster.

  15. Application of geo-microbial prospecting method for finding oil and gas reservoirs

    Science.gov (United States)

    Rasheed, M. A.; Hasan, Syed Zaheer; Rao, P. L. Srinivasa; Boruah, Annapurna; Sudarshan, V.; Kumar, B.; Harinarayana, T.

    2015-03-01

    Microbial prospecting of hydrocarbons is based on the detection of anomalous population of hydrocarbon oxidizing bacteria in the surface soils, indicates the presence of subsurface oil and gas accumulation. The technique is based on the seepage of light hydrocarbon gases such as C1-C4 from the oil and gas pools to the shallow surface that provide the suitable conditions for the development of highly specialized bacterial population. These bacteria utilize hydrocarbon gases as their only food source and are found enriched in the near surface soils above the hydrocarbon bearing structures. The methodology involves the collection of soil samples from the survey area, packing, preservation and storage of samples in pre-sterilized sample bags under aseptic and cold conditions till analysis and isolation and enumeration of hydrocarbon utilizing bacteria such as methane, ethane, propane, and butane oxidizers. The contour maps for the population density of hydrocarbon oxidizing bacteria are drawn and the data can be integrated with geological, geochemical, geophysical methods to evaluate the hydrocarbon prospect of an area and to prioritize the drilling locations thereby reducing the drilling risks and achieve higher success in petroleum exploration. Microbial Prospecting for Oil and Gas (MPOG) method success rate has been reported to be 90%. The paper presents details of microbial prospecting for oil and gas studies, excellent methodology, future development trends, scope, results of study area, case studies and advantages.

  16. Three-Dimensional Computed Tomography as a Method for Finding Die Attach Voids in Diodes

    Science.gov (United States)

    Brahm, E. N.; Rolin, T. D.

    2010-01-01

    NASA analyzes electrical, electronic, and electromechanical (EEE) parts used in space vehicles to understand failure modes of these components. The diode is an EEE part critical to NASA missions that can fail due to excessive voiding in the die attach. Metallography, one established method for studying the die attach, is a time-intensive, destructive, and equivocal process whereby mechanical grinding of the diodes is performed to reveal voiding in the die attach. Problems such as die attach pull-out tend to complicate results and can lead to erroneous conclusions. The objective of this study is to determine if three-dimensional computed tomography (3DCT), a nondestructive technique, is a viable alternative to metallography for detecting die attach voiding. The die attach voiding in two- dimensional planes created from 3DCT scans was compared to several physical cross sections of the same diode to determine if the 3DCT scan accurately recreates die attach volumetric variability

  17. Finding an optimal method for imaging lymphatic vessels of the upper limb

    Energy Technology Data Exchange (ETDEWEB)

    O' Mahony, Susan; Purushotham, Arnie D. [Cambridge Breast Unit, Addenbrooke' s Hospital, Cambridge (United Kingdom); Rose, Sarah L.; Chilvers, Alison J.; Ballinger, James R.; Solanki, Chandra K.; Barber, Robert W.; Peters, A. Michael [Department of Nuclear Medicine, Addenbrooke' s Hospital, Hills Road, CB2 2QQ, Cambridge (United Kingdom); Mortimer, Peter S. [Department of Medicine, St George' s Hospital, London (United Kingdom)

    2004-04-01

    Lymphoscintigraphy involves interstitial injection of radiolabelled particulate materials or radioproteins. Although several variations in the technique have been described, their place in clinical practice remains controversial. Traditional diagnostic criteria are based primarily on lymph node appearances but in situations such as breast cancer, where lymph nodes may have been excised, these criteria are of limited use. In these circumstances, lymphatic vessel morphology takes on greater importance as a clinical endpoint, so a method that gives good definition of lymphatic vessels would be useful. In patients with breast cancer, for example, such a method, used before and after lymph node resection, may assist in predicting the development of breast cancer-related lymphoedema. The aim of this study was to optimise a method for the visualisation of lymphatic vessels. Subcutaneous (sc) and intradermal (id) injection sites were compared, and technetium-99m nanocolloid, a particulate material, was compared with {sup 99m}Tc-human immunoglobulin (HIG), which is a soluble macromolecule. Twelve normal volunteers were each studied on two occasions. In three subjects, id {sup 99m}Tc-HIG was compared with sc {sup 99m}Tc-HIG, in three id {sup 99m}Tc-nanocolloid was compared with sc {sup 99m}Tc-nanocolloid, in three id {sup 99m}Tc-HIG was compared with id {sup 99m}Tc-nanocolloid and in three sc {sup 99m}Tc-HIG was compared with sc {sup 99m}Tc-nanocolloid. Endpoints were quality of lymphatic vessel definition, the time after injection at which vessels were most clearly visualised, the rate constant of depot disappearance (k) and the systemic blood accumulation rate as measured by gamma camera imaging over the liver or cardiac blood pool. Excellent definition of lymphatic vessels was obtained following id injection of either radiopharmaceutical, an injection route that was clearly superior to sc. Differences between radiopharmaceuticals were less clear, although after id injection, {sup 99m}Tc-HIG gave images that were marginally but significantly better than those given by {sup 99m}Tc-nanocolloid. Image quality correlated inversely with time after injection at which the best image was obtained, consistent with the notion that good vessel definition was dependent on a ''narrow'' bolus width. k was approximately three times higher after id injection than after sc injection but it was not significantly different between radiopharmaceuticals for either injection route. Intradermal {sup 99m}Tc-HIG gave a cardiac blood pool signal that, over the first 60 min, increased about five times faster than that with sc {sup 99m}Tc-HIG, but no clear difference was observed in the rate of increase in hepatic activity between id {sup 99m}Tc-nanocolloid and sc {sup 99m}Tc-nanocolloid. We conclude that id injection provides rapid access of radiotracers to lymphatic vessels, which is ideal for imaging lymphatic vessel morphology. {sup 99m}Tc-HIG is marginally superior to nanocolloid for this purpose and, in drainage basins from which lymph nodes have been excised, is not handicapped by a potentially inferior ability, compared with radiocolloid, to image lymph nodes. (orig.)

  18. A COMPARATIVE STUDY TO FIND A SUITABLE METHOD FOR TEXT DOCUMENT CLUSTERING

    Directory of Open Access Journals (Sweden)

    Dr.M.Punithavalli

    2012-01-01

    Full Text Available Text mining is used in various text related tasks such as information extraction, concept/entity extraction,document summarization, entity relation modeling (i.e., learning relations between named entities,categorization/classification and clustering. This paper focuses on document clustering, a field of textmining, which groups a set of documents into a list of meaningful categories. The main focus of thispaper is to present a performance analysis of various techniques available for document clustering. Theresults of this comparative study can be used to improve existing text data mining frameworks andimprove the way of knowledge discovery. This paper considers six clustering techniques for documentclustering. The techniques are grouped into three groups namely Group 1 - K-means and its variants(traditional K-means and K* Means algorithms, Group 2 - Expectation Maximization and its variants(traditional EM, Spherical Gaussian EM algorithm and Linear Partitioning and Reallocation clustering(LPR using EM algorithms, Group 3 - Semantic-based techniques (Hybrid method and Feature-basedalgorithms. A total of seven algorithms are considered and were selected based on their popularity inthe text mining field. Several experiments were conducted to analyze the performance of the algorithmand to select the winner in terms of cluster purity, clustering accuracy and speed of clustering.

  19. Iterative methods for finding optimal quantum measurements under minimum-error and minimax criteria

    Science.gov (United States)

    Nakahira, Kenji; Kato, Kentaro; Usuda, Tsuyoshi Sasaki

    2015-01-01

    We investigate the problem of computing optimal quantum measurements in both minimal measuring and minimax strategies. A Belavkin weighted square-root measurement (BWSRM) with appropriate weights can represent the measurement that maximizes the correct probability for any given prior probabilities of quantum states. Using this fact, we propose methods for computing optimal solutions by optimizing the weights of the BWSRM. First, we explain the conditions for the BWSRM to be optimal. In particular, we argue that if a BWSRM with certain weights is a minimax measurement, then the minimax probabilities can be immediately obtained. Next, we propose an extension of the iterative algorithm developed by Ježek et al. [Phys. Rev. A 65, 060301 (2002), 10.1103/PhysRevA.65.060301] for maximizing the correct probability. We prove that, for a linearly independent pure state set, Ježek et al.'s algorithm converges to an optimal measurement. We also propose an iterative algorithm for a minimax solution and prove that, for a pure state set, our algorithm monotonically decreases the difference between estimated and true minimax values. Finally the performance of our algorithms is evaluated through numerical experiments.

  20. An efficient method to find potentially universal population genetic markers, applied to metazoans

    Directory of Open Access Journals (Sweden)

    Chenuil Anne

    2010-09-01

    Full Text Available Abstract Background Despite the impressive growth of sequence databases, the limited availability of nuclear markers that are sufficiently polymorphic for population genetics and phylogeography and applicable across various phyla restricts many potential studies, particularly in non-model organisms. Numerous introns have invariant positions among kingdoms, providing a potential source for such markers. Unfortunately, most of the few known EPIC (Exon Primed Intron Crossing loci are restricted to vertebrates or belong to multigenic families. Results In order to develop markers with broad applicability, we designed a bioinformatic approach aimed at avoiding multigenic families while identifying intron positions conserved across metazoan phyla. We developed a program facilitating the identification of EPIC loci which allowed slight variation in intron position. From the Homolens databases we selected 29 gene families which contained 52 promising introns for which we designed 93 primer pairs. PCR tests were performed on several ascidians, echinoderms, bivalves and cnidarians. On average, 24 different introns per genus were amplified in bilaterians. Remarkably, five of the introns successfully amplified in all of the metazoan genera tested (a dozen genera, including cnidarians. The influence of several factors on amplification success was investigated. Success rate was not related to the phylogenetic relatedness of a taxon to the groups that most influenced primer design, showing that these EPIC markers are extremely conserved in animals. Conclusions Our new method now makes it possible to (i rapidly isolate a set of EPIC markers for any phylum, even outside the animal kingdom, and thus, (ii compare genetic diversity at potentially homologous polymorphic loci between divergent taxa.

  1. Quantum size correction to the work function and the centroid of excess charge in positively ionized simple metal clusters

    Directory of Open Access Journals (Sweden)

    M. Payami

    2003-12-01

    Full Text Available  In this work, we have shown the important role of the finite-size correction to the work function in predicting the correct position of the centroid of excess charge in positively charged simple metal clusters with different values . For this purpose, firstly we have calculated the self-consistent Kohn-Sham energies of neutral and singly-ionized clusters with sizes in the framework of local spin-density approximation and stabilized jellium model (SJM as well as simple jellium model (JM with rigid jellium. Secondly, we have fitted our results to the asymptotic ionization formulas both with and without the size correction to the work function. The results of fittings show that the formula containing the size correction predict a correct position of the centroid inside the jellium while the other predicts a false position, outside the jellium sphere.

  2. The Pade approximant method for finding the Hilbert-Schmidt eigenvalues and eigenfunctions in two- and three-body problems

    International Nuclear Information System (INIS)

    An approach is proposed which makes it possible to obtain the Hilbert-Schmidt (or Sturm-Liouville) eigenvalue and eigenfunctions for two-or three-body systems over the entire domain of analyticity of these functions in energy on the basis of calculations of bound states only. It is shown how this method may be used to find the two- and three-body resonances and the near-threshold states. (orig.)

  3. A region finding method to remove the noise from the images of the human hand gesture recognition system

    Science.gov (United States)

    Khan, Muhammad Jibran; Mahmood, Waqas

    2015-12-01

    The performance of the human hand gesture recognition systems depends on the quality of the images presented to the system. Since these systems work in real time environment the images may be corrupted by some environmental noise. By removing the noise the performance of the system can be enhanced. So far different noise removal methods have been presented in many researches to eliminate the noise but all have its own limitations. We have presented a region finding method to deal with the environmental noise that gives better results and enhances the performance of the human hand gesture recognition systems so that the recognition rate of the system can be improved.

  4. The Shortlist Method for fast computation of the Earth Mover's Distance and finding optimal solutions to transportation problems.

    Science.gov (United States)

    Gottschlich, Carsten; Schuhmacher, Dominic

    2014-01-01

    Finding solutions to the classical transportation problem is of great importance, since this optimization problem arises in many engineering and computer science applications. Especially the Earth Mover's Distance is used in a plethora of applications ranging from content-based image retrieval, shape matching, fingerprint recognition, object tracking and phishing web page detection to computing color differences in linguistics and biology. Our starting point is the well-known revised simplex algorithm, which iteratively improves a feasible solution to optimality. The Shortlist Method that we propose substantially reduces the number of candidates inspected for improving the solution, while at the same time balancing the number of pivots required. Tests on simulated benchmarks demonstrate a considerable reduction in computation time for the new method as compared to the usual revised simplex algorithm implemented with state-of-the-art initialization and pivot strategies. As a consequence, the Shortlist Method facilitates the computation of large scale transportation problems in viable time. In addition we describe a novel method for finding an initial feasible solution which we coin Modified Russell's Method. PMID:25310106

  5. The Shortlist Method for Fast Computation of the Earth Mover's Distance and Finding Optimal Solutions to Transportation Problems

    Science.gov (United States)

    Gottschlich, Carsten; Schuhmacher, Dominic

    2014-01-01

    Finding solutions to the classical transportation problem is of great importance, since this optimization problem arises in many engineering and computer science applications. Especially the Earth Mover's Distance is used in a plethora of applications ranging from content-based image retrieval, shape matching, fingerprint recognition, object tracking and phishing web page detection to computing color differences in linguistics and biology. Our starting point is the well-known revised simplex algorithm, which iteratively improves a feasible solution to optimality. The Shortlist Method that we propose substantially reduces the number of candidates inspected for improving the solution, while at the same time balancing the number of pivots required. Tests on simulated benchmarks demonstrate a considerable reduction in computation time for the new method as compared to the usual revised simplex algorithm implemented with state-of-the-art initialization and pivot strategies. As a consequence, the Shortlist Method facilitates the computation of large scale transportation problems in viable time. In addition we describe a novel method for finding an initial feasible solution which we coin Modified Russell's Method. PMID:25310106

  6. Centroid and Envelope Eynamics of Charged Particle Beams in an Oscillating Wobbler and External Focusing Lattice for Heavy Ion Fusion Applications

    International Nuclear Information System (INIS)

    Recent heavy ion fusion target studies show that it is possible to achieve ignition with direct drive and energy gain larger than 100 at 1MJ. To realize these advanced, high-gain schemes based on direct drive, it is necessary to develop a reliable beam smoothing technique to mitigate instabilities and facilitate uniform deposition on the target. The dynamics of the beam centroid can be explored as a possible beam smoothing technique to achieve a uniform illumination over a suitably chosen region of the target. The basic idea of this technique is to induce an oscillatory motion of the centroid for each transverse slice of the beam in such a way that the centroids of different slices strike different locations on the target. The centroid dynamics is controlled by a set of biased electrical plates called 'wobblers'. Using a model based on moments of the Vlasov-Maxwell equations, we show that the wobbler deflection force acts only on the centroid motion, and that the envelope dynamics are independent of the wobbler fields. If the conducting wall is far away from the beam, then the envelope dynamics and centroid dynamics are completely decoupled. This is a preferred situation for the beam wobbling technique, because the wobbler system can be designed to generate the desired centroid motion on the target without considering its effects on the envelope and emittance. A conceptual design of the wobbler system for a heavy ion fusion driver is briefly summarized.

  7. Centroid and Envelope Eynamics of Charged Particle Beams in an Oscillating Wobbler and External Focusing Lattice for Heavy Ion Fusion Applications

    Energy Technology Data Exchange (ETDEWEB)

    Ronald C. Davidson and B. Grant Logan

    2011-07-19

    Recent heavy ion fusion target studies show that it is possible to achieve ignition with direct drive and energy gain larger than 100 at 1MJ. To realize these advanced, high-gain schemes based on direct drive, it is necessary to develop a reliable beam smoothing technique to mitigate instabilities and facilitate uniform deposition on the target. The dynamics of the beam centroid can be explored as a possible beam smoothing technique to achieve a uniform illumination over a suitably chosen region of the target. The basic idea of this technique is to induce an oscillatory motion of the centroid for each transverse slice of the beam in such a way that the centroids of different slices strike different locations on the target. The centroid dynamics is controlled by a set of biased electrical plates called 'wobblers'. Using a model based on moments of the Vlasov-Maxwell equations, we show that the wobbler deflection force acts only on the centroid motion, and that the envelope dynamics are independent of the wobbler fields. If the conducting wall is far away from the beam, then the envelope dynamics and centroid dynamics are completely decoupled. This is a preferred situation for the beam wobbling technique, because the wobbler system can be designed to generate the desired centroid motion on the target without considering its effects on the envelope and emittance. A conceptual design of the wobbler system for a heavy ion fusion driver is briefly summarized.

  8. Temnothorax crasecundus sp. n. – a cryptic Eurocaucasian ant species (Hymenoptera, Formicidae discovered by Nest Centroid Clustering

    Directory of Open Access Journals (Sweden)

    Bernhard Seifert

    2015-01-01

    Full Text Available The paper integrates two independent studies of numeric morphology-based alpha-taxonomy of the cryptic ant species Temnothorax crassispinus (Karavajev, 1926 and T. crasecundus sp. n. conducted by different investigators, using different equipment, considering different character combinations and evaluating different samples. Samples investigated included 603 individual workers from 203 nests – thereof 104 nest samples measured by Seifert and 99 by Csösz. The material originated from Europe, Asia Minor and Caucasia. There was a very strong interspecific overlap in any of the 29 shape characters recorded and subjective expert determination failed in many cases. Primary classification hypotheses were formed by the exploratory data analysis Nest Centroid (NC clustering and corrected to final species hypotheses by an iterative linear discriminant analysis algorithm. The evaluation of Seifert’s and Csösz’s data sets arrived at fully congruent conclusions. NC-Ward and NC-K-means clustering disagreed from the final species hypothesis in only 1.9 and 1.9% of the samples in Seifert’s data set and by 1.1 and 2.1% in Csösz’s data set which is a strong argument for heterospecificity. The type series of T. crassispinus and T. crasecundus sp. n. were allocated to different clusters with p = 0.9851 and p = 0.9912 respectively. The type series of the junior synonym T. slavonicus (Seifert, 1995 was allocated to the T. crassispinus cluster with p = 0.9927. T. crasecundus sp. n. and T. crassispinus are parapatric species with a long contact zone stretching from the Peloponnisos peninsula across Bulgaria northeast to the southern Ukraine. There is no indication for occurrence of interspecifically mixed nests or intraspecific polymorphism. However, a significant reduction of interspecific morphological distance at sites with syntopic occurrence of both species indicates local hybridization. The results are discussed within the context of the Pragmatic Species Concept of Seifert (2014. The taxonomic description and a differential diagnosis of T. crasecundus sp. n. are given.

  9. Solving the Task of Finding the Meaning of Dreams as a Method of Exploring Comprehension of Meanings of Life

    Directory of Open Access Journals (Sweden)

    Kubarev V.S.

    2015-10-01

    Full Text Available The paper presents outcomes of a quantitative psychotechnological research on the process of one's comprehension of his/her own life. It focuses on the reflective mechanisms of realizing meanings of life, thus further developing research on meaning formations of personality within the culturalactivity approach. For these purposes a method of solving the task of finding the meaning of a dream was used in the study, which is in fact an operationalization of the method of productive amplification of consciousness. Rather than examining the already formed contents of meanings of life available for introspective descriptions, this method allows the exploration of the constructive activity of consciousness through which these meanings of life are formed. The main outcome is the reconstruction and empirical model of reflective activity carried out by the individual in the process of comprehending meanings of life and his/her life situation

  10. Energy Method of Finding Distribution Constants of an Antiferromagnetic Vector for an Antidot System in a Two-sublattice Antiferromagnet

    Directory of Open Access Journals (Sweden)

    V.V. Kulish

    2015-06-01

    Full Text Available The paper investigates the antiferromagnetic vector distribution in an antiferromagnetic film with a system of antidots. A static distribution of the antiferromagnetic vector is written and a method – based on the minimization of the antiferromagnet energy – that allows reducing the number of boundary conditions required for finding the constants of this distribution is proposed. Equations for the distribution constants are obtained for the both cases of minimizing the antiferromagnet energy by one and by two distribution constants that enter the expression for the antiferromagnet energy. The method is illustrated on a system of one isolated antidot. For such system, one additional condition – for the case when two boundary conditions on the surface of the antidot are given – and two additional conditions – for the case when one boundary condition on the surface of the antidot is given – on the distribution constants are written.

  11. The Exploration of the Artistic Methods and Significances of Cartoonised Characters of A Good Man Is Hard to Find

    Directory of Open Access Journals (Sweden)

    Ke-ke ZHANG

    2005-06-01

    Full Text Available Flannery O’Connor is one of the 20th Century Southern American writers, whose usual theme of absurdity and alienation is well embodied in her classic short story A Good Man Is Hard to Find. This paper mainly deals with the cartoonised characters, especially the granny. The artistic methods used to describe the characters are closely related to the following: realistic method, exaggerative method, metaphorical method, and symbolic method. This article attempts to explore the artistic methods used to describe the characters and their significances and also their contributions to the theme of absurdity and alienation.
    Key words: A Good Man Is Hard to Find, cartoonised character, absurdity
    Résumé Flannery O’Connor est une des femmes écrivains très connues des Etats-Unis du IIe siècle. Son recueil des nouvelles « A Good Man Is Hard to Find » attire surtout plus d’attention des lecteurs. Il décris des personnages humouristiques très vives, ce qui se traduit en évidence par la grand-mère. Les méthodes de description des personnages caricaturistes( les méthodes artistiques peuvent de résumer en : méthodes réalistique, méthode exagérative, méthode métaphorique et méthode symbolique. Cette thèse part des personnages humoristiques et cherche les formes de description et les significations des personnages dans des oeuves pour dévoiler le thème d’absurdité.
    Mots-clés: A Good Man Is Hard to Find, les personnages humoristiques, l’absurdité.
    摘 要 弗蘭納裏 •奧康納是 20世紀美國著名女作家。她的短篇小說集《好人難尋》較引人注意,而其中《好人難尋》更是倍受關注。她刻畫了栩栩如生的漫畫式人物,這一特點在老奶奶身上表現得尤為突出。漫畫式人物的表現方式 (藝術手法可概括為:寫實法,誇張法,比喻法與象徵法。本文擬從小說中漫畫式人物出發,探討此類人物在作品中的表現方式及其意義,從而揭示其荒誕主題。
    關鍵詞:好人難尋;漫畫式人物;荒誕

  12. Meeting report: discussions and preliminary findings on extracellular RNA measurement methods from laboratories in the NIH Extracellular RNA Communication Consortium.

    Science.gov (United States)

    Laurent, Louise C; Abdel-Mageed, Asim B; Adelson, P David; Arango, Jorge; Balaj, Leonora; Breakefield, Xandra; Carlson, Elizabeth; Carter, Bob S; Majem, Blanca; Chen, Clark C; Cocucci, Emanuele; Danielson, Kirsty; Courtright, Amanda; Das, Saumya; Abd Elmageed, Zakaria Y; Enderle, Daniel; Ezrin, Alan; Ferrer, Marc; Freedman, Jane; Galas, David; Gandhi, Roopali; Huentelman, Matthew J; Van Keuren-Jensen, Kendall; Kalani, Yashar; Kim, Yong; Krichevsky, Anna M; Lai, Charles; Lal-Nag, Madhu; Laurent, Clara D; Leonardo, Trevor; Li, Feng; Malenica, Ivana; Mondal, Debasis; Nejad, Parham; Patel, Tushar; Raffai, Robert L; Rubio, Renee; Skog, Johan; Spetzler, Robert; Sun, Jie; Tanriverdi, Kahraman; Vickers, Kasey; Wang, Liang; Wang, Yaoyu; Wei, Zhiyun; Weiner, Howard L; Wong, David; Yan, Irene K; Yeri, Ashish; Gould, Stephen

    2015-01-01

    Extracellular RNAs (exRNAs) have been identified in all tested biofluids and have been associated with a variety of extracellular vesicles, ribonucleoprotein complexes and lipoprotein complexes. Much of the interest in exRNAs lies in the fact that they may serve as signalling molecules between cells, their potential to serve as biomarkers for prediction and diagnosis of disease and the possibility that exRNAs or the extracellular particles that carry them might be used for therapeutic purposes. Among the most significant bottlenecks to progress in this field is the lack of robust and standardized methods for collection and processing of biofluids, separation of different types of exRNA-containing particles and isolation and analysis of exRNAs. The Sample and Assay Standards Working Group of the Extracellular RNA Communication Consortium is a group of laboratories funded by the U.S. National Institutes of Health to develop such methods. In our first joint endeavour, we held a series of conference calls and in-person meetings to survey the methods used among our members, placed them in the context of the current literature and used our findings to identify areas in which the identification of robust methodologies would promote rapid advancements in the exRNA field. PMID:26320937

  13. Meeting report: discussions and preliminary findings on extracellular RNA measurement methods from laboratories in the NIH Extracellular RNA Communication Consortium

    Directory of Open Access Journals (Sweden)

    Louise C. Laurent

    2015-08-01

    Full Text Available Extracellular RNAs (exRNAs have been identified in all tested biofluids and have been associated with a variety of extracellular vesicles, ribonucleoprotein complexes and lipoprotein complexes. Much of the interest in exRNAs lies in the fact that they may serve as signalling molecules between cells, their potential to serve as biomarkers for prediction and diagnosis of disease and the possibility that exRNAs or the extracellular particles that carry them might be used for therapeutic purposes. Among the most significant bottlenecks to progress in this field is the lack of robust and standardized methods for collection and processing of biofluids, separation of different types of exRNA-containing particles and isolation and analysis of exRNAs. The Sample and Assay Standards Working Group of the Extracellular RNA Communication Consortium is a group of laboratories funded by the U.S. National Institutes of Health to develop such methods. In our first joint endeavour, we held a series of conference calls and in-person meetings to survey the methods used among our members, placed them in the context of the current literature and used our findings to identify areas in which the identification of robust methodologies would promote rapid advancements in the exRNA field.

  14. Pseudometrically Constrained Centroidal Voronoi Tessellations: Generating uniform antipodally symmetric points on the unit sphere with a novel acceleration strategy and its applications to Diffusion and 3D radial MRI

    CERN Document Server

    Koay, Cheng Guan

    2012-01-01

    Purpose: The purpose of this work is to investigate the hypothesis that uniform sampling measurements that are endowed with antipodal symmetry play an important role when the raw data and image data are related through the Fourier relationship as in q-space diffusion MRI and 3D radial MRI. Currently, it is extremely challenging to generate large uniform antipodally symmetric point sets suitable for 3D radial MRI. A novel approach is proposed to solve this important and long-standing problem. Methods: The proposed method is based upon constrained centroidal Voronoi tessellations of the upper hemisphere with a novel pseudometric. Geometrically intuitive approach to tessellating the upper hemisphere is also proposed. Results: The average time complexity of the proposed centroidal tessellations was shown to be effectively on the order of the product of the number of iterations and the number of generators. For small sample size, the proposed method was comparable to the state-of-the-art iterative method in terms ...

  15. Using quantitative and qualitative data in health services research – what happens when mixed method findings conflict? [ISRCTN61522618

    Directory of Open Access Journals (Sweden)

    Howel Denise

    2006-03-01

    Full Text Available Abstract Background In this methodological paper we document the interpretation of a mixed methods study and outline an approach to dealing with apparent discrepancies between qualitative and quantitative research data in a pilot study evaluating whether welfare rights advice has an impact on health and social outcomes among a population aged 60 and over. Methods Quantitative and qualitative data were collected contemporaneously. Quantitative data were collected from 126 men and women aged over 60 within a randomised controlled trial. Participants received a full welfare benefits assessment which successfully identified additional financial and non-financial resources for 60% of them. A range of demographic, health and social outcome measures were assessed at baseline, 6, 12 and 24 month follow up. Qualitative data were collected from a sub-sample of 25 participants purposively selected to take part in individual interviews to examine the perceived impact of welfare rights advice. Results Separate analysis of the quantitative and qualitative data revealed discrepant findings. The quantitative data showed little evidence of significant differences of a size that would be of practical or clinical interest, suggesting that the intervention had no impact on these outcome measures. The qualitative data suggested wide-ranging impacts, indicating that the intervention had a positive effect. Six ways of further exploring these data were considered: (i treating the methods as fundamentally different; (ii exploring the methodological rigour of each component; (iii exploring dataset comparability; (iv collecting further data and making further comparisons; (v exploring the process of the intervention; and (vi exploring whether the outcomes of the two components match. Conclusion The study demonstrates how using mixed methods can lead to different and sometimes conflicting accounts and, using this six step approach, how such discrepancies can be harnessed to interrogate each dataset more fully. Not only does this enhance the robustness of the study, it may lead to different conclusions from those that would have been drawn through relying on one method alone and demonstrates the value of collecting both types of data within a single study. More widespread use of mixed methods in trials of complex interventions is likely to enhance the overall quality of the evidence base.

  16. Radiation organ doses received in a nationwide cohort of U.S. radiologic technologists: methods and findings.

    Science.gov (United States)

    Simon, Steven L; Preston, Dale L; Linet, Martha S; Miller, Jeremy S; Sigurdson, Alice J; Alexander, Bruce H; Kwon, Deukwoo; Yoder, R Craig; Bhatti, Parveen; Little, Mark P; Rajaraman, Preetha; Melo, Dunstana; Drozdovitch, Vladimir; Weinstock, Robert M; Doody, Michele M

    2014-11-01

    In this article, we describe recent methodological enhancements and findings from the dose reconstruction component of a study of health risks among U.S. radiologic technologists. An earlier version of the dosimetry published in 2006 used physical and statistical models, literature-reported exposure measurements for the years before 1960, and archival personnel monitoring badge data from cohort members through 1984. The data and models previously described were used to estimate annual occupational radiation doses for 90,000 radiological technologists, incorporating information about each individual's employment practices based on a baseline survey conducted in the mid-1980s. The dosimetry methods presented here, while using many of the same methods as before, now estimate 2.23 million annual badge doses (personal dose equivalent) for the years 1916-1997 for 110,374 technologists, but with numerous methodological improvements. Every technologist's annual dose is estimated as a probability density function to reflect uncertainty about the true dose. Multiple realizations of the entire cohort distribution were derived to account for shared uncertainties and possible biases in the input data and assumptions used. Major improvements in the dosimetry methods from the earlier version include: A substantial increase in the number of cohort member annual badge dose measurements; Additional information on individual apron usage obtained from surveys conducted in the mid-1990s and mid-2000s; Refined modeling to develop lognormal annual badge dose probability density functions using censored data regression models; Refinements of cohort-based annual badge probability density functions to reflect individual work patterns and practices reported on questionnaires and to more accurately assess minimum detection limits; and Extensive refinements in organ dose conversion coefficients to account for uncertainties in radiographic machine settings for the radiographic techniques employed. For organ dose estimation, we rely on well-researched assumptions about critical exposure-related variables and their changes over the decades, including the peak kilovoltage and filtration typically used in conducting radiographic examinations, and the usual body location for wearing radiation monitoring badges, the latter based on both literature and national recommendations. We have derived organ dose conversion coefficients based on air-kerma weighting of photon fluences from published X-ray spectra and derived energy-dependent transmission factors for protective lead aprons of different thicknesses. Findings are presented on estimated organ doses for 12 organs and tissues: red bone marrow, female breast, thyroid, brain, lung, heart, colon, ovary, testes, skin of trunk, skin of head and neck and arms, and lens of the eye. PMID:25361400

  17. Mixed methods evaluation of targeted case finding for cardiovascular disease prevention using a stepped wedged cluster RCT

    Directory of Open Access Journals (Sweden)

    Marshall Tom

    2012-10-01

    Full Text Available Abstract Background A pilot project cardiovascular prevention was implemented in Sandwell (West Midlands, UK. This used electronic primary care records to identify untreated patients at high risk of cardiovascular disease then invited these high risk patients for assessment by a nurse in their own general practice. Those found to be eligible for treatment were offered treatment. During the pilot a higher proportion of high risk patients were started on treatment in the intervention practices than in control practices. Following the apparent success of the prevention project, it was intended to extend the service to all practices across the Sandwell area. However the pilot project was not a robust evaluation. There was a need for an efficient evaluation that would not disrupt the planned rollout of the project. Methods/design Project nurses will sequentially implement targeted cardiovascular case finding in a phased way across all general practices, with the sequence of general practices determined randomly. This is a stepped wedge randomised controlled trial design. The target population is patients aged 35 to 74, without diabetes or cardiovascular disease whose ten-year cardiovascular risk, (determined from data in their electronic records is ?20%. The primary outcome is the number of high risk patients started on treatment, because these data could be efficiently obtained from electronic primary care records. From this we can determine the effects of the case finding programme on the proportion of high risk patients started on treatment in practices before and after implementation of targeted case finding. Cost-effectiveness will be modelled from the predicted effects of treatments on cardiovascular events and associated health service costs. Alongside the implementation it is intended to interview clinical staff and patients who participated in the programme in order to determine acceptability to patients and clinicians. Practical considerations meant that 26 practices in Sandwell could be randomised, including about 6,250 patients at high risk of cardiovascular disease. This gives sufficient power for evaluation. Discussion It is possible to design a stepped wedge randomised controlled trial using routine data to determine the primary outcome to evaluate implementation of a cardiovascular prevention programme.

  18. Multi-response optimisation of the extraction solvent system for phenolics and antioxidant activities from fermented soy flour using a simplex-centroid design.

    Science.gov (United States)

    Handa, Cíntia Ladeira; de Lima, Fernando Sanches; Guelfi, Marcela Fernanda Geton; Georgetti, Sandra Regina; Ida, Elza Iouko

    2016-04-15

    A simplex-centroid design comprising three solvents (water, ethanol and methanol) was used to optimise the extraction mixture for phenolics and antioxidant activities from defatted soy flour fermented with Monascus purpureus or Aspergillus oryzae. Total phenolics were more efficiently extracted using only water for both samples. The highest antioxidant activities by the DPPH and ABTS methods were obtained using extraction mixtures containing at least 75 wt% water. Specific water:ethanol:methanol ratios promoted the joint optimisation of the total phenolic and isoflavone contents as well as antioxidant activities: 0.5:0.375:0.125 (wt/wt/wt) and 0.5:0.3:0.2 (wt/wt/wt) from defatted soy flour fermented with M. purpureus or A. oryzae, respectively. However, a water:ethanol ratio of 0.5:0.5 (wt/wt) was deemed optimal because it is comprised of green solvents and yielded results that were greater than 90% of the multi-response maximum values. Both the solvents and the sample matrix strongly influenced the extractability of total phenolics and isoflavones. PMID:26616938

  19. Meat intake, cooking methods, dietary carcinogens, and colorectal cancer risk: findings from the Colorectal Cancer Family Registry

    International Nuclear Information System (INIS)

    Diets high in red meat and processed meats are established colorectal cancer (CRC) risk factors. However, it is still not well understood what explains this association. We conducted comprehensive analyses of CRC risk and red meat and poultry intakes, taking into account cooking methods, level of doneness, estimated intakes of heterocyclic amines (HCAs) that accumulate during meat cooking, tumor location, and tumor mismatch repair proficiency (MMR) status. We analyzed food frequency and portion size data including a meat cooking module for 3364 CRC cases, 1806 unaffected siblings, 136 unaffected spouses, and 1620 unaffected population-based controls, recruited into the CRC Family Registry. Odds ratios (OR) and 95% confidence intervals (CI) for nutrient density variables were estimated using generalized estimating equations. We found no evidence of an association between total nonprocessed red meat or total processed meat and CRC risk. Our main finding was a positive association with CRC for pan-fried beefsteak (Ptrend < 0.001), which was stronger among MMR deficient cases (heterogeneity P = 0.059). Other worth noting associations, of borderline statistical significance after multiple testing correction, were a positive association between diets high in oven-broiled short ribs or spareribs and CRC risk (Ptrend = 0.002), which was also stronger among MMR-deficient cases, and an inverse association with grilled hamburgers (Ptrend = 0.002). Our results support the role of specific meat types and cooking practices as possible sources of human carcinogens relevant for CRC risk

  20. Computational Method and a Numerical Algorithm for Finding the Optimal Control Policy for a Partially Observable System

    Science.gov (United States)

    Makis, Viliam; Kim, Michael Jong; Jiang, Rui

    2009-09-01

    In this paper a computational method and numerical algorithm is developed for finding the optimal control policy for a partially observable system subject to random failure. The condition of the system is modeled by an unobservable continuous-time homogeneous Markov chain. Multivariate data stochastically related to the system state is collected at equidistant sampling times. The system is controlled by a multivariate Bayesian control chart, i.e. full inspection followed by maintenance is performed when the posterior probability that the system is in the warning state exceeds a control limit. A statistical constraint is considered which bounds the probability of a true alarm given by the control chart. The objective is to minimize the long-run expected average cost per unit time by determining the optimal values of the control limit and sampling interval subject to the statistical constraint. The stochastic evolution of the posterior probability process is analyzed and computational algorithm is developed in the semi-Markov decision process framework. Numerical examples are provided which illustrate the effect of the statistical constraint and the performance of the Bayesian control chart is compared with the traditional multivariate ?2 control chart.

  1. A double inequality for bounding Toader mean by the centroidal mean

    Indian Academy of Sciences (India)

    Yun Hua; Feng Qi

    2014-11-01

    In this paper, the authors find the best numbers and such that $\\overline{C}(\\alpha a+ (1 - \\alpha)b$, $\\alpha b + (1 - \\alpha)a) \\lt T (a, b) \\lt \\overline{C} (\\beta a + (1 - \\beta)b, \\beta b + (1 - \\beta)a)$ for all , $b \\gt 0$ with $a \

  2. Aims, methods and preliminary findings of the Physical Activity, Nutrition and Allergies in Children Examined in Athens (PANACEA epidemiological study

    Directory of Open Access Journals (Sweden)

    Papadimitriou Anastasios

    2007-07-01

    Full Text Available Abstract Background To determine the prevalence of asthma symptoms in a sample of Greek children aged 10–12 years, and to evaluate these rates in relation to anthropometric, lifestyle characteristics and dietary habits. Methods During 2006, 700 schoolchildren (323 male and 377 female, aged 10–12 years (4th to 6th school grade, were selected from 18 schools located in the greater Athens area. The schools were randomly selected from a list provided by the regional educational offices. To achieve a representative sample the schools enrolled were selected from various region of the Athens area. For each child a questionnaire was completed that was developed for the purposes of the study to retrieve information on: age, sex, school class, other socio-demographic characteristics, anthropometric measurements, dietary habits (through a semi-quantitative Food Frequency Questionnaire and physical activity status; the presence of asthma and allergies was assessed by the standard ISAAC questionnaire. Results The prevalence of wheezing in the past was 25% in boys and 19% in girls, while the prevalence of current wheezing was 9.0% in boys and 5.8% in girls. The prevalence of any asthma symptoms was 27.6% in boys and 20.4% in girls. Multiple logistic regression analysis revealed that increased body weight and sedentary lifestyle is associated with asthma symptoms only in boys. Conclusion The present cross-sectional study cannot establish causal relationships between asthma and increased body weight of schoolchildren; however, our findings underline the associations between asthma, increased body weight, and physical activity at population level, and urge for actions that should be taken by public health policy makers in order to prevent these conditions among children.

  3. A measure of variable planar locations anchored on the centroid of the vowel space

    DEFF Research Database (Denmark)

    Watt, Dominic; Fabricius, Anne

    2011-01-01

    This paper presents part of an ongoing research program which aims to apply mathematical and geometrical analytic methods to vowel formant data to enable the quantification of parameters of variation of interest to sociophoneticians. We open with an overview of recent research working towards a set...

  4. A Medoid-based Method for Clustering Categorical Data

    OpenAIRE

    Ali Seman; Zainab Abu Bakar; Azizian Mohd. Sapawi; Ida Rosmini Othman

    2013-01-01

    Medoid-based method is an alternative technique to centroid-based method for partitional clustering algorithms. This method has been incorporated in a recently introduced clustering algorithm for categorical data, called k-Approximate Modal Haplotype (k-AMH) algorithm. This study reports the performance evaluation between the medoid-based method represented by the k-AMH algorithm and the centroid-based method represented by the extended k-Mode algorithm, the k-Po...

  5. Robust of Doppler Centroid for Mapping Sea Surface Current by Using Radar Satellite Data

    OpenAIRE

    Mazlan Hashim; Maged Marghany

    2009-01-01

    Problem statement: Sea surface current retrieving from Synthetic Aperture Radar (SAR) is required standard methods due to the complexity of sea surface ocean imaging in SAR data. In this context, various analytical models have been developed which describe overall effects of sea surface roughness on the Doppler signal mechanisms. Nevertheless, such models are limited in the complexity of the sea surface current estimation that can be used. In fact, the resolution of the sea surface Doppler ve...

  6. Robust seed selection algorithm for k-means type algorithms - Optimal centroids using high density object

    OpenAIRE

    K Karteeka Pavan; Allam Appa Rao; A.V. DATTATREYA RAO; Sridhar, G. R.

    2011-01-01

    Selection of initial seeds greatly affects the quality of the clusters and in k-means typealgorithms. Most of the seed selection methods result different results in different independent runs. Wepropose a single, optimal, outlier insensitive seed selection algorithm for k-means type algorithms asextension to k-means++. The experimental results on synthetic, real and on microarray data setsdemonstrated that effectiveness of the new algorithm in producing the clustering results

  7. Experimental Validation of the Dynamic Inertia Measurement Method to Find the Mass Properties of an Iron Bird Test Article

    Science.gov (United States)

    Chin, Alexander W.; Herrera, Claudia Y.; Spivey, Natalie D.; Fladung, William A.; Cloutier, David

    2015-01-01

    The mass properties of an aerospace vehicle are required by multiple disciplines in the analysis and prediction of flight behavior. Pendulum oscillation methods have been developed and employed for almost a century as a means to measure mass properties. However, these oscillation methods are costly, time consuming, and risky. The NASA Armstrong Flight Research Center has been investigating the Dynamic Inertia Measurement, or DIM method as a possible alternative to oscillation methods. The DIM method uses ground test techniques that are already applied to aerospace vehicles when conducting modal surveys. Ground vibration tests would require minimal additional instrumentation and time to apply the DIM method. The DIM method has been validated on smaller test articles, but has not yet been fully proven on large aerospace vehicles.

  8. An Example of the Use of Research Methods and Findings as an Experiential Learning Exercise in an Accounting Theory Course

    Science.gov (United States)

    Bublitz, Bruce; Philipich, Kirk; Blatz, Robert

    2015-01-01

    The purpose of this teaching note is to describe an experiential learning exercise used in a master's level financial accounting theory course. The experiential exercise illustrates how order effects can affect user's judgments, a long-standing research finding. This experiential exercise was used in an attempt to make students more cognizant of…

  9. Experiences of racism and discrimination among migrant care workers in England: findings from a mixed-methods research project

    OpenAIRE

    Stevens, Martin; Hussein, Shereen; Manthorpe, Jill

    2011-01-01

    Abstract Abstract This article reports part of the findings of research undertaken in 2007-09 that aimed to investigate the contribution made by migrant workers to the care workforce in England. The study involved analysis of national statistics on social care and social workers and semi-structured interviews with a wide range of stakeholders, including 96 migrant care workers. The interviews elicited some accounts relating experiences of racism and discrimination from some peo...

  10. Radiation Organ Doses Received in a Nationwide Cohort of U.S. Radiologic Technologists: Methods and Findings

    OpenAIRE

    Simon, Steven L; Preston, Dale L.; Linet, Martha S.; Miller, Jeremy S.; Sigurdson, Alice J; Bruce H. Alexander; Kwon, Deukwoo; Yoder, R. Craig; Bhatti, Parveen; Little, Mark P.; Rajaraman, Preetha; Melo, Dunstana; Drozdovitch, Vladimir; Weinstock, Robert M.; Doody, Michele M

    2014-01-01

    In this article, we describe recent methodological enhancements and findings from the dose reconstruction component of a study of health risks among U.S. radiologic technologists. An earlier version of the dosimetry published in 2006 used physical and statistical models, literature-reported exposure measurements for the years before 1960, and archival personnel monitoring badge data from cohort members through 1984. The data and models previously described were used to estimate annual occupat...

  11. A genetic-algorithm-based method to find unitary transformations for any desired quantum computation and application to a one-bit oracle decision problem

    Science.gov (United States)

    Bang, Jeongho; Yoo, Seokwon

    2014-12-01

    We propose a genetic-algorithm-based method to find the unitary transformations for any desired quantum computation. We formulate a simple genetic algorithm by introducing the "genetic parameter vector" of the unitary transformations to be found. In the genetic algorithm process, all components of the genetic parameter vectors are supposed to evolve to the solution parameters of the unitary transformations. We apply our method to find the optimal unitary transformations and to generalize the corresponding quantum algorithms for a realistic problem, the one-bit oracle decision problem, or the often-called Deutsch problem. By numerical simulations, we can faithfully find the appropriate unitary transformations to solve the problem by using our method. We analyze the quantum algorithms identified by the found unitary transformations and generalize the variant models of the original Deutsch's algorithm.

  12. Six Forms of Variety in Students' Moral Reasoning: An Age-Old Distinction Enabling New Methods and Findings

    Science.gov (United States)

    Backman, Ylva; Gardelli, Viktor

    2015-01-01

    In this study, the age-old distinction between decision method and criterion of rightness, commonly employed in normative ethics, was used to attain a detailed understanding of inter- and intrapersonal variety in students' moral reasoning. A total of 24 Swedish students, 12-15 years of age, were interviewed. Inter- and intrapersonal varieties in…

  13. Population Size Estimation of Men Who Have Sex with Men in Tbilisi, Georgia; Multiple Methods and Triangulation of Findings

    Science.gov (United States)

    Sulaberidze, Lela; Mirzazadeh, Ali; Chikovani, Ivdity; Shengelia, Natia; Tsereteli, Nino; Gotsadze, George

    2016-01-01

    Introduction An accurate estimation of the population size of men who have sex with men (MSM) is critical to the success of HIV program planning and to monitoring of the response to epidemic as a whole, but is quite often missing. In this study, our aim was to estimate the population size of MSM in Tbilisi, Georgia and compare it with other estimates in the region. Methods In the absence of a gold standard for estimating the population size of MSM, this study reports a range of methods, including network scale-up, mobile/web apps multiplier, service and unique object multiplier, network-based capture-recapture, Handcock RDS-based and Wisdom of Crowds methods. To apply all these methods, two surveys were conducted: first, a household survey among 1,015 adults from the general population, and second, a respondent driven sample of 210 MSM. We also conducted a literature review of MSM size estimation in Eastern European and Central Asian countries. Results The median population size of MSM generated from all previously mentioned methods was estimated to be 5,100 (95% Confidence Interval (CI): 3,243 ~ 9,088). This corresponds to 1.42% (95%CI: 0.9% ~ 2.53%) of the adult male population in Tbilisi. Conclusion Our size estimates of the MSM population (1.42% (95%CI: 0.9% ~ 2.53%) of the adult male population in Tbilisi) fall within ranges reported in other Eastern European and Central Asian countries. These estimates can provide valuable information for country level HIV prevention program planning and evaluation. Furthermore, we believe, that our results will narrow the gap in data availability on the estimates of the population size of MSM in the region. PMID:26828366

  14. Sylfiden findes

    DEFF Research Database (Denmark)

    Christensen, Anne Middelboe

    Sylfiden findes. Men hvordan kan sylfiden findes - og bare være en drøm? Denne ’svævebog’ fortolker længslen i Bournonvilles internationale ballethit - gennem nye fotos af katastrofefotografen Jan Grarup samt fortolkende svæveessays, meddigtende flakserier, en sylfidescrapbog med anmeldelser af...

  15. Perturbed damped pendulum: finding periodic solutions via averaging method / Perturbações do pêndulo amortecido: encontrando soluções periódicas via método averaging

    Scientific Electronic Library Online (English)

    Douglas D., Novaes.

    2013-03-01

    Full Text Available Utilizando o modelo do pêndulo amortecido, introduzimos o método "averaging" no estudo de soluções periódicas de sistemas dinâmicos com pequenas perturbações não autónomas. Considerando perturbações do sistema do pêndulo amortecido, fornecemos condições suficientes para a existência de soluções peri [...] ódicas de pequena amplitude. O método "averaging" fornece uma ferramenta útil no estudo de sistemas dinâmicos e é acessível a estudantes de pós-graduação. Abstract in english Using the damped pendulum model we introduce the averaging method to study the periodic solutions of dynamical systems with small non-autonomous perturbation. We provide sufficient conditions for the existence of periodic solutions with small amplitude of the non-linear perturbed damped pendulum. Th [...] e averaging method provides a useful means to study dynamical systems, accessible to Master and PhD students.

  16. Diagnostic methods in finding out the causes of infertility, results of HSG examination and laparoscopy in infertile women examined at the Gynecological Ward of the City Hospital

    International Nuclear Information System (INIS)

    The paper presents diagnostic methods and the results of hysterosalpingography (HSG) and laparoscopy examination, with special attention being drawn to the usefulness of these methods in finding out the causes of infertility. 51 patients with primary and second infertility were examined. HSG and laparoscopy make it possible to diagnose correctly the cause of infertility. They also enable adequate and early classification of patients for further diagnosis and treatment at highly specialized centers dealing with the problems of infertility. (author)

  17. Consumer Attitudes and Perceptions on mHealth Privacy and Security: Findings From a Mixed-Methods Study.

    Science.gov (United States)

    Atienza, Audie A; Zarcadoolas, Christina; Vaughon, Wendy; Hughes, Penelope; Patel, Vaishali; Chou, Wen-Ying Sylvia; Pritts, Joy

    2015-01-01

    This study examined consumers' attitudes and perceptions regarding mobile health (mHealth) technology use in health care. Twenty-four focus groups with 256 participants were conducted in 5 geographically diverse locations. Participants were also diverse in age, education, race/ethnicity, gender, and rural versus urban settings. Several key themes emerged from the focus groups. Findings suggest that consumer attitudes regarding mHealth privacy/security are highly contextualized, with concerns depending on the type of information being communicated, where and when the information is being accessed, who is accessing or seeing the information, and for what reasons. Consumers frequently considered the tradeoffs between the privacy/security of using mHealth technologies and the potential benefits. Having control over mHealth privacy/security features and trust in providers were important issues for consumers. Overall, this study found significant diversity in attitudes regarding mHealth privacy/security both within and between traditional demographic groups. Thus, to address consumers' concerns regarding mHealth privacy and security, a one-size-fits-all approach may not be adequate. Health care providers and technology developers should consider tailoring mHealth technology according to how various types of information are communicated in the health care setting, as well as according to the comfort, skills, and concerns individuals may have with mHealth technology. PMID:25868685

  18. Characterization of a millefiori glass find from Aquincum by SEM-EDX and micro-PIXE methods

    International Nuclear Information System (INIS)

    Research has been focused on the analysis of archaeological glasses from the Roman age and medieval times. Study of ancient millefiori type glasses from the collection of Hungarian Museums has been started. A test measurement, carried out on a glass fragment supposedly part of a dish, was performed by SEM-EDX and micro-PIXE methods. Complementary analytical data were obtained for texture and composition. Results suggest that Roman and Mesopotamian techniques were used together. Our data contribute to data bases of millefiori glasses.

  19. A vision-based hybrid particle tracking velocimetry (PTV) technique using a modified cascade correlation peak-finding method

    Energy Technology Data Exchange (ETDEWEB)

    Lei, Y.C. [University of Washington, Department of Aeronautics and Astronautics, Seattle, WA (United States); Canadian Aviation Electronics Inc., Performance Group Division, Quebec, CA (Canada); Tien, W.H.; Dabiri, D. [University of Washington, Department of Aeronautics and Astronautics, Seattle, WA (United States); Duncan, J. [University of Washington, Department of Aeronautics and Astronautics, Seattle, WA (United States); Edwards Air Force Base, CA (United States); Paul, M. [University of Washington, Department of Aeronautics and Astronautics, Seattle, WA (United States); Eglin Air Force Base, FL (United States); Ponchaut, N. [Exponent, Natick, MA (United States); Mouton, C. [RAND Corporation, Santa Monica, CA (United States); Roesgen, T. [ETH Zurich, Institute of Fluid Dynamics, Zurich (Switzerland); Hove, J. [University of Cincinnati College of Medicine, Molecular and Cellular Physiology, Cincinnati, OH (United States)

    2012-11-15

    A novel technique for particle tracking velocimetry is presented in this paper to overcome the issue of overlapping particle images encountered in the flows with high particle density or under volumetric illumination conditions. To achieve this goal, algorithms for particle identification and tracking are developed based on current methods and validated with both synthetic and experimental image sets. The results from synthetic image tests show that the particle identification algorithm is able to resolve overlapped particle images up to 50 % under noisy conditions, while keeping the root mean square peak location error under 0.07 pixels. The algorithm is also robust to the size changes up to a size ratio of 5. The tracking method developed from a classic computer vision matching algorithm is capable of capturing a velocity gradient up to 0.3 while maintaining the error under 0.2 pixels. Sensitivity tests were performed to describe the optimum conditions for the technique in terms of particle image density, particle image sizes and velocity gradients, also its sensitivity to errors of the PIV results that guide the tracking process. The comparison with other existing tracking techniques demonstrates that this technique is able to resolve more vectors out of a dense particle image field. (orig.)

  20. Investigation of methods to search for the boundaries on the image and their use on lung hardware of methods finding saliency map

    Science.gov (United States)

    Semenishchev, E. A.; Marchuk, V. I.; Fedosov, V. P.; Stradanchenko, S. G.; Ruslyakov, D. V.

    2015-05-01

    This work aimed to study computationally simple method of saliency map calculation. Research in this field received increasing interest for the use of complex techniques in portable devices. A saliency map allows increasing the speed of many subsequent algorithms and reducing the computational complexity. The proposed method of saliency map detection based on both image and frequency space analysis. Several examples of test image from the Kodak dataset with different detalisation considered in this paper demonstrate the effectiveness of the proposed approach. We present experiments which show that the proposed method providing better results than the framework Salience Toolbox in terms of accuracy and speed.

  1. Improvements and new findings in Monte Carlo method with complex-valued weights for neutron leakage-corrected assembly calculations

    International Nuclear Information System (INIS)

    The author of this paper recently proposed a Monte Carlo calculation algorithm to solve a complex transport equation with complex-valued weights. The algorithm enables one to generate neutron leakage-corrected group constants and anisotropic diffusion coefficients for a unit fuel pin cell or assembly. The group constants are subsequently used for multi-group deterministic core calculations. The technique, however, had some limitations in applying itself to general problems. Some improvements have been done in this paper. The reflective boundary condition has newly become available. It has been found that a cumbersome weight cancellation of fission sources with positive and negative weights can be omitted in general fuel assembly geometries. A homogenization method of diffusion coefficients for a fuel assembly has been proposed. (author)

  2. Determination of the centroid depths of the depth profiles of ion-implanted analytes by angle-resolved electron microbeam analysis

    International Nuclear Information System (INIS)

    Angle-resolved signal ratio electron microbeam analysis (AR/SR/EMA) was applied for the determination of the centroid depth of the ion-implanted depth profile of 100 keV 1016 cm-2 P in Si. The experiment is part of an investigation on the suitability of AR/SR/EMA for application in the (non-destructive) calibration of ion-implanted reference materials. (author)

  3. Plotting of liquidus surface in the system In - InP - GaAs - InAs using simplex-centroidal planning

    International Nuclear Information System (INIS)

    Liquidus surface in the In-InP-GaAs-InAs system is plotted using simplex-centroidal planning. The analysis of the results obtained permitted to state that growth of indium phosphide concentration increases liquidus temperature in quasiternary cross section of the system with constant indium content, increase of indium arsenide content gives the inverse result, while change of gallium arsenide concentration does not result in essential change of liquidus temperature (at constant concentration ratio of the other two compounds)

  4. Comparação dos métodos de determinação da estabilidade oxidativa de biodiesel B100, em mistura com antioxidantes sintéticos: aplicação do delineamento simplex-centroide com variável de processo

    OpenAIRE

    João Rafael de Moraes Cini; Dionísio Borsato; Carmen Luísa Barbosa Guedes; Hágata Cremasco da Silva; Rodolfo Lopes Coppo

    2013-01-01

    The Rancimat and accelerated stove tests were used to determine the oxidative stability of B100 biodiesel mixed with synthetic antioxidants. The predictive equations, with process variable, were obtained by applying a simplex-centroid design. Regardless of the antioxidant used, all assays carried out with the accelerated stove test presented storage time longer than 177.88 d, the greatest value obtained by applying the Rancimat test. The t test, applied to the parameters containing the proces...

  5. Numerical methods for finding periodic points in discrete maps. High order islands chains and noble barriers in a toroidal magnetic configuration

    Energy Technology Data Exchange (ETDEWEB)

    Steinbrecher, G. [Association Euratom-Nasti Romania, Dept. of Theoretical Physics, Physics Faculty, University of Craiova (Romania); Reuss, J.D.; Misguich, J.H. [Association Euratom-CEA Cadarache, 13 - Saint-Paul-lez-Durance (France). Dept. de Recherches sur la Fusion Controlee

    2001-11-01

    We first remind usual physical and mathematical concepts involved in the dynamics of Hamiltonian systems, and namely in chaotic systems described by discrete 2D maps (representing the intersection points of toroidal magnetic lines in a poloidal plane in situations of incomplete magnetic chaos in Tokamaks). Finding the periodic points characterizing chains of magnetic islands is an essential step not only to determine the skeleton of the phase space picture, but also to determine the flux of magnetic lines across semi-permeable barriers like Cantori. We discuss here several computational methods used to determine periodic points in N dimensions, which amounts to solve a set of N nonlinear coupled equations: Newton method, minimization techniques, Laplace or steepest descend method, conjugated direction method and Fletcher-Reeves method. We have succeeded to improve this last method in an important way, without modifying its useful double-exponential convergence. This improved method has been tested and applied to finding periodic points of high order m in the 2D 'Tokamap' mapping, for values of m along rational chains of winding number n/m converging towards a noble value where a Cantorus exists. Such precise positions of periodic points have been used in the calculation of the flux across this Cantorus. (authors)

  6. The Tourette International Collaborative Genetics (TIC Genetics) study, finding the genes causing Tourette syndrome : objectives and methods

    DEFF Research Database (Denmark)

    Dietrich, Andrea; Fernandez, Thomas V

    2015-01-01

    Tourette syndrome (TS) is a neuropsychiatric disorder characterized by recurrent motor and vocal tics, often accompanied by obsessive-compulsive disorder and/or attention-deficit/hyperactivity disorder. While the evidence for a genetic contribution is strong, its exact nature has yet to be clarified fully. There is now mounting evidence that the genetic risks for TS include both common and rare variants and may involve complex multigenic inheritance or, in rare cases, a single major gene. Based on recent progress in many other common disorders with apparently similar genetic architectures, it is clear that large patient cohorts and open-access repositories will be essential to further advance the field. To that end, the large multicenter Tourette International Collaborative Genetics (TIC Genetics) study was established. The goal of the TIC Genetics study is to undertake a comprehensive gene discovery effort, focusing both on familial genetic variants with large effects within multiply affected pedigrees and on de novo mutations ascertained through the analysis of apparently simplex parent-child trios with non-familial tics. The clinical data and biomaterials (DNA, transformed cell lines, RNA) are part of a sharing repository located within the National Institute for Mental Health Center for Collaborative Genomics Research on Mental Disorders, USA, and will be made available to the broad scientific community. This resource will ultimately facilitate better understanding of the pathophysiology of TS and related disorders and the development of novel therapies. Here, we describe the objectives and methods of the TIC Genetics study as a reference for future studies from our group and to facilitate collaboration between genetics consortia in the field of TS.

  7. A New Method to Find the Fractional Slot Windings Structures from a Distributed Slot Windings Permanent Magnet Synchronous Machine and Comparative Study for a HEV Application

    OpenAIRE

    Nguyen, Phi Hung; Hoang, Emmanuel; Gabsi, Mohamed; Lécrivain, Michel

    2010-01-01

    This paper presents a distributed slot permanent magnet synchronous machine (PMSM). It's a machine characterized by a distributed windings stator and a surface mounted PM rotor. First, a basic PMSM called “classical” has been studied. Then, we have developed a new method to find the others machines with the same winding distribution on stator but with different rotor pole number so that we have obtained PMSMs with fractional slot windings. From the fractional slot structures developed, we hav...

  8. Finding the transition state of quasi-barrierless reactions by a growing string method for newton trajectories: application to the dissociation of methylenecyclopropene and cyclopropane.

    Science.gov (United States)

    Quapp, Wolfgang; Kraka, Elfi; Cremer, Dieter

    2007-11-01

    A method for finding a transition state (TS) between a reactant minimum and a quasi-flat, high dissociation plateau on the potential energy surface is described. The method is based on the search of a growing string (GS) along reaction pathways defined by different Newton trajectories (NT). Searches with the GS-NT method always make it possible to identify the TS region because monotonically increasing NTs cross at the TS or, if not monotonically increasing, possess turning points that are located in the TS region. The GS-NT method is applied to quasi-barrierless and truly barrierless chemical reactions. Examples are the dissociation of methylenecyclopropene to acetylene and vinylidene, for which a small barrier far out in the exit channel is found, and the cycloaddition of singlet methylene and ethene, which is barrierless for a broad reaction channel with Cs-symmetry reminiscent of a mountain cirque formed by a glacier. PMID:17705351

  9. The New Multi-HAzard and MulTi-RIsK Assessment MethodS for Europe (MATRIX) Project - An overview of its major findings

    Science.gov (United States)

    Fleming, Kevin; Zschau, Jochen; Gasparini, Paolo

    2014-05-01

    Recent major natural disasters, such as the 2011 T?hoku earthquake, tsunami and subsequent Fukushima nuclear accident, have raised awareness of the frequent and potentially far-reaching interconnections between natural hazards. Such interactions occur at the hazard level, where an initial hazard may trigger other events (e.g., an earthquake triggering a tsunami) or several events may occur concurrently (or nearly so), e.g., severe weather around the same time as an earthquake. Interactions also occur at the vulnerability level, where the initial event may make the affected community more susceptible to the negative consequences of another event (e.g., an earthquake weakens buildings, which are then damaged further by windstorms). There is also a temporal element involved, where changes in exposure may alter the total risk to a given area. In short, there is the likelihood that the total risk estimated when considering multiple hazard and risks and their interactions is greater than the sum of their individual parts. It is with these issues in mind that the European Commission, under their FP7 program, supported the New Multi-HAzard and MulTi-RIsK Assessment MethodS for Europe or MATRIX project (10.2010 to 12.2013). MATRIX set out to tackle multiple natural hazards (i.e., those of concern to Europe, namely earthquakes, landslides, volcanos, tsunamis, wild fires, storms and fluvial and coastal flooding) and risks within a common theoretical framework. The MATRIX work plan proceeded from an assessment of single-type risk methodologies (including how uncertainties should be treated), cascade effects within a multi-hazard environment, time-dependent vulnerability, decision making and support for multi-hazard mitigation and adaption, and an assessment of how the multi-hazard and risk viewpoint may be integrated into current decision making and risk mitigation programs, considering the existing single-hazard and risk focus. Three test sites were considered during the project: Naples, Cologne, and the French West Indies. In addition, a software platform, the MATRIX-Common IT sYstem (MATRIX-CITY), was developed to allow the evaluation of characteristic multi-hazard and risk scenarios in comparison to single-type analyses. This presentation therefore outlines the more significant outcomes of the project, in particular those dealing with the harmonization of single-type hazards, cascade event analysis, time-dependent vulnerability changes and the response of the disaster management community to the MATRIX point of view.

  10. Global pathways to men's caregiving: mixed methods findings from the International Men and Gender Equality Survey and the Men Who Care study.

    Science.gov (United States)

    Kato-Wallace, Jane; Barker, Gary; Eads, Marci; Levtov, Ruti

    2014-01-01

    Promoting men's participation in unpaid care work is part of the Programme of Action for the International Conference on Population and Development. However, men's involvement in care work does not mirror the advances women have made in paid work outside the home. This mixed method study explores which men are more involved in caregiving, and what childhood and adulthood factors influence their level of involvement. Quantitative research presents findings from 1169 men across six countries with children aged 0-4, and a qualitative study presents findings from in-depth interviews with 83 men engaged in atypical caregiving practices. Survey research finds that being taught to care for children, witnessing one's father take care of one's siblings, respondents' present attitudes about gender equality and having outside help (or none, in some cases) were all also associated with men's higher level of involvement. Qualitative research reveals that men's experiences of violence, the normalisation of domestic work as children and life circumstances rather than greater-than-average beliefs in gender equality all propelled them into care work. Findings suggest that engaging more men into care work implies changes to policies and structural realities in the workplace coupled with changing gender attitudes. These insights inform policy and practice aimed at promoting greater involvement in care work by men. PMID:24938308

  11. A comparison of three clustering methods for finding subgroups in MRI, SMS or clinical data : SPSS TwoStep Cluster analysis, Latent Gold and SNOB

    DEFF Research Database (Denmark)

    Kent, Peter; Jensen, Rikke K

    2014-01-01

    BACKGROUND: There are various methodological approaches to identifying clinically important subgroups and one method is to identify clusters of characteristics that differentiate people in cross-sectional and/or longitudinal data using Cluster Analysis (CA) or Latent Class Analysis (LCA). There is a scarcity of head-to-head comparisons that can inform the choice of which clustering method might be suitable for particular clinical datasets and research questions. Therefore, the aim of this study was to perform a head-to-head comparison of three commonly available methods (SPSS TwoStep CA, Latent Gold LCA and SNOB LCA). METHODS: The performance of these three methods was compared: (i) quantitatively using the number of subgroups detected, the classification probability of individuals into subgroups, the reproducibility of results, and (ii) qualitatively using subjective judgments about each program's ease of use and interpretability of the presentation of results.We analysed five real datasets of varying complexity in a secondary analysis of data from other research projects. Three datasets contained only MRI findings (n = 2,060 to 20,810 vertebral disc levels), one dataset contained only pain intensity data collected for 52 weeks by text (SMS) messaging (n = 1,121 people), and the last dataset contained a range of clinical variables measured in low back pain patients (n = 543 people). Four artificial datasets (n = 1,000 each) containing subgroups of varying complexity were also analysed testing the ability of these clustering methods to detect subgroups and correctly classify individuals when subgroup membership was known. RESULTS: The results from the real clinical datasets indicated that the number of subgroups detected varied, the certainty of classifying individuals into those subgroups varied, the findings had perfect reproducibility, some programs were easier to use and the interpretability of the presentation of their findings also varied. The results from the artificial datasets indicated that all three clustering methods showed a near-perfect ability to detect known subgroups and correctly classify individuals into those subgroups. CONCLUSIONS: Our subjective judgement was that Latent Gold offered the best balance of sensitivity to subgroups, ease of use and presentation of results with these datasets but we recognise that different clustering methods may suit other types of data and clinical research questions.

  12. A colorimetric method for highly sensitive and accurate detection of iodide by finding the critical color in a color change process using silver triangular nanoplates

    International Nuclear Information System (INIS)

    Graphical abstract: -- Highlights: •Demonstrated a new colorimetric strategy for iodide detection by silver nanoplates. •The colorimetric strategy is to find the critical color in a color change process. •The colorimetric strategy is more accurate and sensitive than common colorimetry. •Discovered a new morphological transformation phenomenon of silver nanoplates. -- Abstract: In this contribution, we demonstrated a novel colorimetric method for highly sensitive and accurate detection of iodide using citrate-stabilized silver triangular nanoplates (silver TNPs). Very lower concentration of iodide can induce an appreciable color change of silver TNPs solution from blue to yellow by fusing of silver TNPs to nanoparticles, as confirmed by UV–vis absorption spectroscopy and transmission electron microscopy (TEM). The principle of this colorimetric assay is not an ordinary colorimetry, but a new colorimetric strategy by finding the critical color in a color change process. With this strategy, 0.1 ?M of iodide can be recognized within 30 min by naked-eyes observation, and lower concentration of iodide down to 8.8 nM can be detected using a spectrophotometer. Furthermore, this high sensitive colorimetric assay has good accuracy, stability and reproducibility comparing with other ordinary colorimetry. We believe this new colorimetric method will open up a fresh insight of simple, rapid and reliable detection of iodide and can find its future application in the biochemical analysis or clinical diagnosis

  13. Reliability of change in lumbar MRI findings over time in patients with and without disc prosthesis - comparing two different image evaluation methods

    International Nuclear Information System (INIS)

    To assess the reliability of change in lumbar magnetic resonance imaging (MRI) findings evaluated retrospectively by direct comparison of images and by non-comparison. Pre-treatment and 2-year follow-up MRI was performed in 126 patients randomized to disc prosthesis surgery or non-surgical treatment. Two experienced radiologists independently evaluated progress and regress for Modic changes, disc findings, and facet arthropathy (FA) at L3/L4, L4/L5, and L5/S1, both by non-comparison and by comparison of initial and follow-up images. FA was evaluated at all levels, and other findings at non-operated levels. We calculated prevalence- and bias-adjusted kappa (PABAK) values for interobserver agreement. The impact of an adjacent prosthesis (which causes artefacts) and image evaluation method on PABAK was assessed using generalized estimating equations. Image comparison indicated good interobserver agreement on progress and regress (PABAK 0.63-1.00) for Modic changes, posterior high-intensity zone, disc height, and disc contour at L3-S1 and for nucleus pulposus signal and FA at L3/L4; and moderate interobserver agreement (PABAK 0.46-0.59) on decreasing nucleus signal and increasing FA at L4-S1. Image comparison indicated lower (but fair) interobserver agreement (PABAK 0.29) only for increasing FA at L5/S1 in patients with prosthesis in L4/L5 and/or L5/S1. An adjacent prosthesis had no overall impact on PABAK values (p ≥ 0.22). Comparison yielded higher PABAK values than non-comparison (p < 0.001). Regarding changes in lumbar MRI findings over time, comparison of images can provide moderate or good interobserver agreement, and better agreement than non-comparison. An adjacent prosthesis may not reduce agreement on change for most findings. (orig.)

  14. Reliability of change in lumbar MRI findings over time in patients with and without disc prosthesis - comparing two different image evaluation methods

    Energy Technology Data Exchange (ETDEWEB)

    Berg, Linda; Espeland, Ansgar [Haukeland University Hospital, Department of Radiology, Bergen (Norway); University of Bergen, Section for Radiology, Department of Surgical Sciences, Bergen (Norway); Gjertsen, Oeivind [Oslo University Hospital, Department of Neuroradiology, Oslo (Norway); Hellum, Christian [Oslo University Hospital, Department of Orthopaedics, Oslo (Norway); University of Oslo, Department of Orthopaedics, Oslo (Norway); Neckelmann, Gesche [Haukeland University Hospital, Department of Radiology, Bergen (Norway); Johnsen, Lars G. [University Hospital of Trondheim, National Centre for Diseases of the Spine, Trondheim (Norway); University Hospital of Trondheim, Orthopaedic Department, Trondheim (Norway); Eide, Geir E. [Haukeland University Hospital, Centre for Clinical Research, Bergen (Norway); University of Bergen, Department of Public Health and Primary Health Care, Bergen (Norway)

    2012-12-15

    To assess the reliability of change in lumbar magnetic resonance imaging (MRI) findings evaluated retrospectively by direct comparison of images and by non-comparison. Pre-treatment and 2-year follow-up MRI was performed in 126 patients randomized to disc prosthesis surgery or non-surgical treatment. Two experienced radiologists independently evaluated progress and regress for Modic changes, disc findings, and facet arthropathy (FA) at L3/L4, L4/L5, and L5/S1, both by non-comparison and by comparison of initial and follow-up images. FA was evaluated at all levels, and other findings at non-operated levels. We calculated prevalence- and bias-adjusted kappa (PABAK) values for interobserver agreement. The impact of an adjacent prosthesis (which causes artefacts) and image evaluation method on PABAK was assessed using generalized estimating equations. Image comparison indicated good interobserver agreement on progress and regress (PABAK 0.63-1.00) for Modic changes, posterior high-intensity zone, disc height, and disc contour at L3-S1 and for nucleus pulposus signal and FA at L3/L4; and moderate interobserver agreement (PABAK 0.46-0.59) on decreasing nucleus signal and increasing FA at L4-S1. Image comparison indicated lower (but fair) interobserver agreement (PABAK 0.29) only for increasing FA at L5/S1 in patients with prosthesis in L4/L5 and/or L5/S1. An adjacent prosthesis had no overall impact on PABAK values (p {>=} 0.22). Comparison yielded higher PABAK values than non-comparison (p < 0.001). Regarding changes in lumbar MRI findings over time, comparison of images can provide moderate or good interobserver agreement, and better agreement than non-comparison. An adjacent prosthesis may not reduce agreement on change for most findings. (orig.)

  15. Finding Sliesthorp?

    DEFF Research Database (Denmark)

    Dobat, Andres S.

    2015-01-01

    In 2003, a hitherto unknown Viking age settlement was discovered at Füsing in Northern Germany close to Hedeby/Schleswig, the largest of the early Scandinavian towns. Finds and building features suggest a high status residence and a seat of some chiefly elite that flourished from around 700 to the...... and the transformation of socio‐political structures in Northern Europe as it transitioned from prehistory into the middle Ages....

  16. Estimation of the path-averaged wind velocity by cross-correlation of the received power and the shift of laser beam centroid

    Science.gov (United States)

    Marakasov, Dmitri A.; Tsvyk, Ruvim S.

    2015-11-01

    We consider the problem of estimation of the average wind speed on atmospheric path from measurements of time series of average power of the laser radiation detected through the receiving aperture and the position of the centroid of the image of the laser beam. It is shown that the mutual correlation function of these series has a maximum, whose position characterizes the average speed of the cross wind on the path. The dependence of the coordinates and magnitude of the maximum of the correlation function from the size of the receiving aperture and the distribution of turbulence along the atmospheric path.

  17. The impact of the in-orbit background and the X-ray source intensity on the centroiding accuracy of the Swift X-ray telescope

    CERN Document Server

    Ambrosi, R M; Hill, J; Cheruvu, C; Abbey, A F; Short, A D T

    2002-01-01

    The optical components of the Swift Gamma Ray Burst Explorer X-ray Telescope (XRT), consisting of the JET-X spare flight mirror and a charge coupled device of the type used in the EPIC program, were used in a re-calibration study carried out at the Panter facility, which is part of the Max Planck Institute for Extraterrestrial Physics. The objective of this study was to check the focal length and the off axis performance of the mirrors and to show that the half energy width (HEW) of the on-axis point spread function (PSF) was of the order of 16 arcsec at 1.5 keV (Nucl. Instr. and Meth. A 488 (2002) 543; SPIE 4140 (2000) 64) and that a centroiding accuracy better that 1 arcsec could be achieved within the 4 arcmin sampling area designated by the Burst Alert Telescope (Nucl. Instr. and Meth. A 488 (2002) 543). The centroiding accuracy of the Swift XRT's optical components was tested as a function of distance from the focus and off axis position of the PSF (Nucl. Instr. and Meth. A 488 (2002) 543). The presence ...

  18. Factors affecting uncertainty in lung nodule volume estimation with CT: comparisons of findings from two estimation methods in a phantom study

    Science.gov (United States)

    Li, Qin; Gavrielides, Marios A.; Zeng, Rongping; Myers, Kyle J.; Sahiner, Berkman; Petrick, Nicholas

    2015-03-01

    This work aimed to compare two different types of volume estimation methods (a model-based and a segmentationbased method) in terms of identifying factors affecting measurement uncertainty. Twenty-nine synthetic nodules with varying size, radiodensity, and shape were placed in an anthropomorphic thoracic phantom and scanned with a 16- detector row CT scanner. Ten repeat scans were acquired using three exposures and two slice collimations, and were reconstructed with varying slice thicknesses. Nodule volumes were estimated from the reconstructed data using a matched-filter and a segmentation approach. Log transformed volumes were used to obtain measurement error with truth obtained through micro-CT. ANOVA and multiple linear regression were applied to measurement error to identify significant factors affecting volume estimation for each method. Root mean square of measurement errors (RMSE) for meaningful subgroups, repeatability coefficients (RC) for different imaging protocols, and reproducibility coefficients (RDC) for thin and thick collimation conditions were evaluated. Results showed that for both methods, nodule size, shape and slice thickness were significant factors. Collimation was significant for the matched-filter method. RMSEs for matched-filter measurements were in general smaller than segmentation. To achieve RMSE on the order of 15% or less for {5, 8, 9, 10mm} nodules, the corresponding maximum allowable slice thicknesses were {3, 5, 5, 5mm} for the matched-filter and {0.8, 3, 3, 3mm} for the segmentation method. RCs showed similar patterns for both methods, increasing with slice thickness. For 8-10mm nodules, the measurements were highly repeatable provided the slice thickness was ?3mm, regardless of method and across varying acquisition conditions. RDCs were lower for thin collimation than thick collimation protocols. While RDC of matched filter volume estimation results was always lower than segmentation results, for 8-10mm nodules with thin collimation protocols, the measurements for both approaches were highly reproducible (RDC on the order of 15% or less). These findings are valuable for validating lung nodule volume as a quantitative imaging biomarker.

  19. CT findings of minimally invasive adenocarcinoma (MIA) of the lung and comparison of solid portion measurement methods at CT in 52 patients

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Sang Min; Lee, Kyung Hee; Park, Chang Min [Seoul National University Medical Research Center, Department of Radiology, Seoul National University College of Medicine, and Institute of Radiation Medicine, Jongno-gu, Seoul (Korea, Republic of); Goo, Jin Mo [Seoul National University Medical Research Center, Department of Radiology, Seoul National University College of Medicine, and Institute of Radiation Medicine, Jongno-gu, Seoul (Korea, Republic of); Seoul National University College of Medicine, Cancer Research Institute, Seoul (Korea, Republic of); Chung, Doo Hyun; Koh, Jaemoon [Seoul National University College of Medicine, Department of Pathology, Seoul (Korea, Republic of)

    2015-08-15

    We aimed to retrospectively investigate CT findings of minimally invasive adenocarcinoma (MIA) and to determine the appropriate method for measurement of solid portions in MIAs at CT. From May 2012 to April 2014, 55 pulmonary nodules in 52 patients were pathologically confirmed as MIAs and were included in this study. CT findings of MIAs and measurements of solid portions at CT were evaluated by two independent radiologists. Mean size of MIAs was 10.5 mm ± 4.8 (range, 4-28 mm). Fifty-two MIAs manifested as 28 pure ground glass nodules (GGNs) (53.8 % %), 22 part-solid GGNs (42.3 % %), and 2 two solid nodules (3.8 % %) at CT. Lobulated border, bubble lucency, and pleural retraction were frequently found in both observers (26.9-42.3 % %). Differences according to window settings between solid portion size and invasive component size were not significantly different in both observers (p > 0.05). As for interobserver agreement, 95 % CIs for solid portion size in the mediastinal window setting (-2.2 to 3.4; mean, 0.6) were slightly narrower than those in the lung window setting (-2.6 to 3.1; mean, 0.3). Nearly all MIAs appear as pure and part-solid GGNs. Mediastinal and lung window settings can be applied for measurement of solid portions at CT without a significant difference. (orig.)

  20. CT findings of minimally invasive adenocarcinoma (MIA) of the lung and comparison of solid portion measurement methods at CT in 52 patients

    International Nuclear Information System (INIS)

    We aimed to retrospectively investigate CT findings of minimally invasive adenocarcinoma (MIA) and to determine the appropriate method for measurement of solid portions in MIAs at CT. From May 2012 to April 2014, 55 pulmonary nodules in 52 patients were pathologically confirmed as MIAs and were included in this study. CT findings of MIAs and measurements of solid portions at CT were evaluated by two independent radiologists. Mean size of MIAs was 10.5 mm ± 4.8 (range, 4-28 mm). Fifty-two MIAs manifested as 28 pure ground glass nodules (GGNs) (53.8 % %), 22 part-solid GGNs (42.3 % %), and 2 two solid nodules (3.8 % %) at CT. Lobulated border, bubble lucency, and pleural retraction were frequently found in both observers (26.9-42.3 % %). Differences according to window settings between solid portion size and invasive component size were not significantly different in both observers (p > 0.05). As for interobserver agreement, 95 % CIs for solid portion size in the mediastinal window setting (-2.2 to 3.4; mean, 0.6) were slightly narrower than those in the lung window setting (-2.6 to 3.1; mean, 0.3). Nearly all MIAs appear as pure and part-solid GGNs. Mediastinal and lung window settings can be applied for measurement of solid portions at CT without a significant difference. (orig.)

  1. A comprehensive method to find RPO trajectory and incentive scheme for promotion of renewable energy in India with study of impact of RPO on tariff

    International Nuclear Information System (INIS)

    Renewable Purchase Obligation (RPO) regime in India started in 2011 with the announcement of benchmark RPO (BRPO) of states for the Financial Year (FY) 2011 by respective State Electricity Regulatory Commissions (SERC), to promote Renewable Energy (RE). The report submitted to Forum of Regulators (FoR) in this regard has recommended uniform rate of increase of BRPO of states and studied the impact of RPO on tariff for FY 2011–2015. However, more rigorous analysis is needed for fixing BRPO in a scientific manner and for fair allocation of incentives to promote RE. This paper attempts to evaluate all states on a common platform to find BRPO, giving due weightage to the state-wise energy demand and RE generation, ensuring minimum change in BRPO of consecutive years and hence less impact of RPO on tariff. To encourage the states to align their actual RPO with BRPO, a financial incentive scheme is proposed giving due weightage to RE consumption, RE capacity addition and RPO compliance of the states. The methods are illustrated for the Indian states using real system data. A study of RPO's impact on electricity tariff of Indian states is also conducted and reported for FY 2011–2015, considering Renewable Energy Certificate (REC). - Author-Highlights: • Proposes a comprehensive method to find the BRPO of Indian states for promoting RE. • Minimum change in BRPO of consecutive years hence less impact of RPO on tariff. • Incentive scheme to encourage the states to align their actual RPO with BRPO. • Study of impact of RPO on tariff of Indian states is conducted

  2. Subtropical Real Root Finding

    OpenAIRE

    Sturm, T.

    2015-01-01

    We describe a new incomplete but terminating method for real root finding for large multivariate polynomials. We take an abstract view of the polynomial as the set of exponent vectors associated with sign information on the coefficients. Then we employ linear programming to heuristically find roots. There is a specialized variant for roots with exclusively positive coordinates, which is of considerable interest for applications in chemistry and systems biology. An implementation of our method...

  3. New treatment method for developmental dysplasia of the hips after walking age. Arthroscopic reduction with limboplasty based on the findings of preoperative imaging

    International Nuclear Information System (INIS)

    What makes treatment choice for developmental dysplasia of the hips diagnosed after walking age difficult is the poor understanding of prereduction conditions that obstruct the reduction in spatial terms. To evaluate these problems, we employed subtraction three-dimensional imaging to search for the factors involved in intraarticular obstruction. On the basis of the findings of preoperative subtraction three-dimensional imaging from computed tomography, we developed a new method, a minimum invasive arthroscopic reduction with limboplasty, for reduction of developmental dysplasia of the hips after walking age. The purposes of this report were to: describe the technique of the arthroscopic procedure, and evaluate our new method using radiographic parameters. Ten patients with ten hips with developmental dysplasia after walking age treated by arthroscopic reduction with limboplasty were included in this study. The mean age of the patients at reduction was 22.6 months (range, 18.6-29.7 months); mean age at follow up was 7.2 years (range, 3.9-10.9 years); and mean follow up was 5.4 years (range, 1.7-9.0 years). These ten hips were evaluated using radiographic measurements. Moderate or severe avascular necrosis of the femoral head was not observed. Two hips that had a spherical-shaped head with minimal residual height loss or coxa magna were classified as Kalamchi and MacEwen grade 1. Additional surgery had been performed for two hips classified as Severin group 4 during the course of follow up. These two hips were classified as Severin group 1 at final examination. One more hip was classified as Severin group 4 at final examination, and additional surgery was recommended. The remaining seven hips (70%) therefore obtained good evaluations by arthroscopic reduction with limboplasty alone. We developed a new reduction method by using an arthroscopic procedure for the reduction of developmental dysplasia of the hips after walking age when this dysplasia failed to be reduced with nonoperative methods. The result of our new method is acceptable because good evaluations were obtained in 70% of hips 5.4 years after reduction by our new method alone. (author)

  4. Main findings

    International Nuclear Information System (INIS)

    Licensing regimes vary from country to country. When the license regime involves several regulators and several licenses, this may lead to complex situations. Identifying a leading organisation in charge of overall coordination including preparation of the licensing decision is a useful practice. Also, if a stepwise licensing process is implemented, it is important to fix in legislation decisions and/or time points and to identify the relevant actors. There is considerable experience in civil and mining engineering that can be applied when constructing a deep geological disposal facility. Specific challenges are, however, the minimization of disturbances to the host rock and the understanding of its long-term behavior. Construction activities may affect the geo-hydraulic and geochemical properties of the various system components which are important safety features of the repository system. Clearly defined technical specifications and an effective quality management plan are important in ensuring successful repository implementation which is consistent with safety requirements. Monitoring plan should also be defined in advance. The regulatory organization should prepare itself to the licensing review before construction by allocating sufficient resources. It should increase its competence, e.g., by interacting early with the implementer and through its own R and D. This will allow the regulator to define appropriate technical conditions associated to the construction license and to elaborate a relevant inspection plan of the construction work. After construction, obtaining the operational license is the most important and crucial step. Main challenges include (a) establishing sufficient confidence so that the methods for closing the individual disposal units comply with the safety objectives and (b) addressing the issue of ageing of materials during a 50-100 years operational period. This latter challenge is amplified when reversibility/retrievability is required. Managing concomitant construction of new galleries with continuing operation and/or closure in the existing galleries remains as another challenge. There is a need, during the project, to address targets very different in nature and which may potentially compete with each other. Alternative solutions are typically compared and evaluated with a view to lower potential impacts and risks to workers, people and the environment in the short and the long term to as low as reasonably practicable. This is often called 'radiological optimisation'. In repository development, the set of target functions can be much broader, blurring the meaning of 'optimisation'. The visibility and importance to optimisation for licensing varies from country to country, and it may take different names

  5. Quality by Design approach in the development of a solvent-modified micellar electrokinetic chromatography method: finding the design space for the determination of amitriptyline and its impurities.

    Science.gov (United States)

    Furlanetto, S; Orlandini, S; Pasquini, B; Del Bubba, M; Pinzauti, S

    2013-11-13

    A solvent-modified micellar electrokinetic chromatography method was set up for the simultaneous determination of the tricyclic antidepressant amitriptyline (AMI) and its main impurities. The method was developed following Quality by Design (QbD) principles according to ICH Guideline Q8(R2). QbD approach made it possible to find the design space (DS), where quality was assured. After a scouting phase, aimed at selecting a suitable capillary electrophoresis pseudostationary phase, risk assessment tools were employed to define the critical process parameters (CPPs) to be considered in a screening phase (applied voltage, concentration and pH of the background electrolyte, concentration of the surfactant sodium dodecyl sulphate, of the cosurfactant n-butanol and of the organic modifiers acetonitrile and urea). The effects of the seven selected CPPs on critical quality attributes (CQAs), namely resolution values between critical peak pairs and analysis time, were investigated throughout the knowledge space by means of a symmetric screening matrix. Response surface study was then carried out on four selected CPPs by applying a Doehlert Design. Monte-Carlo simulations were performed in order to estimate the probability of meeting the desired specifications on CQAs, and thus to define the DS by means of a risk of failure map. Additional points at the edges of the DS were tested in order to verify the requirements for CQAs to be fulfilled. A control strategy was implemented by defining system suitability tests. The developed method was validated following ICH Guideline Q2(R1), including robustness assessment by Plackett-Burman design, and was applied to the analysis of real samples of amitriptyline coated tablets. PMID:24176512

  6. Forecasting Method for Grouped Time Series with the Use of k-Means Algorithm

    OpenAIRE

    Astakhova, N. N.; Demidova, L. A.; Nikulchev, E. V.

    2015-01-01

    The paper is focused on the forecasting method for time series groups with the use of algorithms for cluster analysis. $K$-means algorithm is suggested to be a basic one for clustering. The coordinates of the centers of clusters have been put in correspondence with summarizing time series data the centroids of the clusters. A description of time series, the centroids of the clusters, is implemented with the use of forecasting models. They are based on strict binary trees and...

  7. Novel Method of Detecting Movement of the Interference Fringes Using One-Dimensional PSD

    OpenAIRE

    Qi Wang; Ji Xia; Xu Liu; Yong Zhao

    2015-01-01

    In this paper, a method of using a one-dimensional position-sensitive detector (PSD) by replacing charge-coupled device (CCD) to measure the movement of the interference fringes is presented first, and its feasibility is demonstrated through an experimental setup based on the principle of centroid detection. Firstly, the centroid position of the interference fringes in a fiber Mach-Zehnder (M-Z) interferometer is solved in theory, showing it has a higher resolution and sensitivity. Accordi...

  8. Challenges from Tuberculosis Diagnosis to Care in Community-Based Active Case Finding among the Urban Poor in Cambodia: A Mixed-Methods Study

    Science.gov (United States)

    Malhotra, Shelly; Koeut, Pichenda; Thai, Sopheak; Khun, Kim Eam; Colebunders, Robert; Lynen, Lut

    2015-01-01

    Background While community-based active case finding (ACF) for tuberculosis (TB) holds promise for increasing early case detection among hard-to-reach populations, limited data exist on the acceptability of active screening. We aimed to identify barriers and explore facilitators on the pathway from diagnosis to care among TB patients and health providers. Methods Mixed-methods study. We administered a survey questionnaire to, and performed in-depth interviews with, TB patients identified through ACF from poor urban settlements in Phnom Penh, Cambodia. Additionally, we conducted focus group discussions and in-depth interviews with community and public health providers involved in ACF, respectively. Results Acceptance of home TB screening was strong among key stakeholders due to perceived reductions in access barriers and in direct and indirect patient costs. Privacy and stigma were not an issue. To build trust and facilitate communication, the participation of community representatives alongside health workers was preferred. Most health providers saw ACF as complementary to existing TB services; however, additional workload as a result of ACF was perceived as straining operating capacity at public sector sites. Proximity to a health facility and disease severity were the strongest determinants of prompt care-seeking. The main reasons reported for delays in treatment-seeking were non-acceptance of diagnosis, high indirect costs related to lost income/productivity and transportation expenses, and anticipated side-effects from TB drugs. Conclusions TB patients and health providers considered home-based ACF complementary to facility-based TB screening. Strong engagement with community representatives was believed critical in gaining access to high risk communities. The main barriers to prompt treatment uptake in ACF were refusal of diagnosis, high indirect costs, and anticipated treatment side-effects. A patient-centred approach and community involvement were essential in mitigating barriers to care in marginalised communities. PMID:26222545

  9. Feasibility, acceptability, and effects of gentle Hatha yoga for women with major depression: findings from a randomized controlled mixed-methods study.

    Science.gov (United States)

    Kinser, Patricia Anne; Bourguignon, Cheryl; Whaley, Diane; Hauenstein, Emily; Taylor, Ann Gill

    2013-06-01

    Major depressive disorder (MDD) is a common, debilitating chronic condition in the United States and worldwide. Particularly in women, depressive symptoms are often accompanied by high levels of stress and ruminations, or repetitive self-critical negative thinking. There is a research and clinical imperative to evaluate complementary therapies that are acceptable and feasible for women with depression and that target specific aspects of depression in women, such as ruminations. To begin to address this need, we conducted a randomized, controlled, mixed-methods community-based study comparing an 8-week yoga intervention with an attention-control activity in 27 women with MDD. After controlling for baseline stress, there was a decrease in depression over time in both the yoga group and the attention-control group, with the yoga group having a unique trend in decreased ruminations. Participants in the yoga group reported experiencing increased connectedness and gaining a coping strategy through yoga. The findings provide support for future large scale research to explore the effects of yoga for depressed women and the unique role of yoga in decreasing rumination. PMID:23706890

  10. Combined radioimmunoassay of 17-alpha-hydroxyprogesterone and 11-desoxycortisol, and of dehydroepiandrosterone-sulphate: Methods and some novel clinical findings

    International Nuclear Information System (INIS)

    The radioimmunoassay (RIA) methods for determining 17-alpha-hydroxyprogesterone (17HOP), 11-desoxycortisol (Cpd.-S), and dehydroepiandrosterone-sulphate, are reported. The plasma levels of these hormones were measured in a series of 15 diagnostic groups including adrenal diseases, fertility-related problems and human growth hormone (HGH) deficiency states. The relations of DHEA-S and growth hormone were studied in a group of children with growth retardation who presented an absent response to HGH stimulation tests. The DHEA-S level found in these patients was significantly lower than that of their age-matched controls. Furthermore, in an etiologically different entity, i.e. head-injury patients, similar findings were also made. In a single case with HGH deficiency due to antibodies against HGH, DHEA-S levels were not detectable. It is suggested that the determination of DHEA-S plasma levels can provide further insight into the classification of patients with fertility-related problems. Furthermore, it appears that DHEA-S can be taken as an indicator for the availability of bioactive human growth hormone. The various forms of congenital adrenal hyperplasia (CAH) can be successfully screened and detected by the determination of the plasma levels of 17-alpha-hydroxyprogesterone (17HOP), of 11-desoxycortisol (Cpd.-S), and of dehydroepiandrosterone-sulphate (DHEA-S). These tests are also relevant in the investigation of patients with hirsutism, hyperandrogenism, and amenorrhea. RIA procedures for the measurement of these hormones are described and new clinical data on DHEA-S are presented in relation to fertility problems both in men and women, such as oligozoospermia, oligomenorrhea and aspermia and, in cases of human growth hormone (HGH), deficiency states such as retarded growth, head-injury patients and, in one case, HGH deficiency due to antibodies directed against HGH. The relations between normo- and hyperprolactinaemia and DHEA-S are also examined

  11. H.U.B city steps: methods and early findings from a community-based participatory research trial to reduce blood pressure among african americans

    Directory of Open Access Journals (Sweden)

    Molaison Elaine

    2011-06-01

    Full Text Available Abstract Background Community-based participatory research (CBPR has been recognized as an important approach to develop and execute health interventions among marginalized populations, and a key strategy to translate research into practice to help reduce health disparities. Despite growing interest in the CBPR approach, CBPR initiatives rarely use experimental or other rigorous research designs to evaluate health outcomes. This behavioral study describes the conceptual frameworks, methods, and early findings related to the reach, adoption, implementation, and effectiveness on primary blood pressure outcomes. Methods The CBPR, social support, and motivational interviewing frameworks are applied to test treatment effects of a two-phased CBPR walking intervention, including a 6-month active intervention quasi experimental phase and 12-month maintenance randomized controlled trial phase to test dose effects of motivational interviewing. A community advisory board helped develop and execute the culturally-appropriate intervention components which included social support walking groups led by peer coaches, pedometer diary self-monitoring, monthly diet and physical activity education sessions, and individualized motivational interviewing sessions. Although the study is on-going, three month data is available and reported. Analyses include descriptive statistics and paired t tests. Results Of 269 enrolled participants, most were African American (94% females (85% with a mean age of 43.8 (SD = 12.1 years. Across the 3 months, 90% of all possible pedometer diaries were submitted. Attendance at the monthly education sessions was approximately 33%. At the 3-month follow-up 227 (84% participants were retained. From baseline to 3-months, systolic BP [126.0 (SD = 19.1 to 120.3 (SD = 17.9 mmHg; p Conclusions This CBPR study highlights implementation factors and signifies the community's active participation in the development and execution of this study. Reach and representativeness of enrolled participants are discussed. Adherence to pedometer diary self-monitoring was better than education session participation. Significant decreases in the primary blood pressure outcomes demonstrate early effectiveness. Importantly, future analyses will evaluate long-term effectiveness of this CBPR behavioral intervention on health outcomes, and help inform the translational capabilities of CBPR efforts.

  12. Finding Those Missing Links

    Science.gov (United States)

    Gunn, Holly

    2004-01-01

    In this article, the author stresses not to give up on a site when a URL returns an error message. Many web sites can be found by using strategies such as URL trimming, searching cached sites, site searching and searching the WayBack Machine. Methods and tips for finding web sites are contained within this article.

  13. Multiresponse optimisation on biodiesel obtained through a ternary mixture of vegetable oil and animal fat: Simplex-centroid mixture design application

    International Nuclear Information System (INIS)

    Highlights: • Mixture experimental design was used which allowed evaluating various responses. • Predictive equation was presented that allows verifying the behavior of the mixtures. • The results depicted that the obtained biodiesel dispensed the use of any additives. - Abstract: The quality of biodiesel is a determining factor in its commercialisation, and parameters such as the Cold Filter Plugging Point (CFPP) and Induction Period (IP) determine its operability in engines on cold days and storage time, respectively. These factors are important in characterisation of the final product. A B100 biodiesel formulation was developed using a multiresponse optimisation, for which the CFPP and cost were minimised, and the IP and yield were maximised. The experiments were carried out according to a simplex-centroid mixture design using soybean oil, beef tallow, and poultry fat. The optimum formulation consisted of 50% soybean oil, 20% beef tallow, and 30% poultry fat and had CFPP values of 1.92 °C, raw material costs of US$ 903.87 ton?1, an IP of 8.28 h, and a yield of 95.68%. Validation was performed in triplicate and the t-test indicated that there were no difference between the estimated and experimental values for none of the dependent variables, thus indicating efficiency of the joint optimisation in the biodiesel production process that met the criteria for CFPP and IP, as well as high yield and low cost

  14. Methods of Pest Control and Direct Yield Loss Assessment of Country Bean (Dolichos lablab) at Farmer`s Field Condition: A Survey Finding

    OpenAIRE

    Ahmed, K. U.; Rahman, M. M.; M. Z. Alam; Ahmed, S.U.

    2004-01-01

    A survey on farmer`s pest control methods and direct yield loss assessment of country bean (Dolichos lablab) was done during September 2000 to February 2001 in North Edilpur and South Mohadebpur villages of Sitakundu under Chittagong district. Results revealed that farmers used Fanfan, Nogos, Ripcord, Malathion, Roxion and Sumithion as chemical methods and applying ash and handpicking of insect pests as non-chemical method to control insect pests. The frequency of insecticide application duri...

  15. The Use of Qualitative Methods in Large-Scale Evaluation: Improving the Quality of the Evaluation and the Meaningfulness of the Findings

    Science.gov (United States)

    Slayton, Julie; Llosa, Lorena

    2005-01-01

    In light of the current debate over the meaning of "scientifically based research", we argue that qualitative methods should be an essential part of large-scale program evaluations if program effectiveness is to be determined and understood. This article chronicles the challenges involved in incorporating qualitative methods into the large-scale…

  16. Overtaking method based on sand-sifter mechanism: Why do optimistic value functions find optimal solutions in multi-armed bandit problems?

    Science.gov (United States)

    Ochi, Kento; Kamiura, Moto

    2015-09-01

    A multi-armed bandit problem is a search problem on which a learning agent must select the optimal arm among multiple slot machines generating random rewards. UCB algorithm is one of the most popular methods to solve multi-armed bandit problems. It achieves logarithmic regret performance by coordinating balance between exploration and exploitation. Since UCB algorithms, researchers have empirically known that optimistic value functions exhibit good performance in multi-armed bandit problems. The terms optimistic or optimism might suggest that the value function is sufficiently larger than the sample mean of rewards. The first definition of UCB algorithm is focused on the optimization of regret, and it is not directly based on the optimism of a value function. We need to think the reason why the optimism derives good performance in multi-armed bandit problems. In the present article, we propose a new method, which is called Overtaking method, to solve multi-armed bandit problems. The value function of the proposed method is defined as an upper bound of a confidence interval with respect to an estimator of expected value of reward: the value function asymptotically approaches to the expected value of reward from the upper bound. If the value function is larger than the expected value under the asymptote, then the learning agent is almost sure to be able to obtain the optimal arm. This structure is called sand-sifter mechanism, which has no regrowth of value function of suboptimal arms. It means that the learning agent can play only the current best arm in each time step. Consequently the proposed method achieves high accuracy rate and low regret and some value functions of it can outperform UCB algorithms. This study suggests the advantage of optimism of agents in uncertain environment by one of the simplest frameworks. PMID:26166266

  17. Granulomatous mastitis: radiological findings

    International Nuclear Information System (INIS)

    Purpose: To evaluate the radiological, ultrasonographic, and magnetic resonance imaging (MRI) findings of idiopathic granulomatous mastitis. Material and Methods: Between April 2002 and June 2005, the mammography, ultrasound, color Doppler ultrasound, non enhanced MR, and dynamic MR findings of nine patients with the preliminary clinical diagnosis of malignancy and the final diagnosis of granulomatous mastitis were evaluated. Results: On mammography, asymmetrical focal densities with no distinct margins, ill-defined masses with spiculated contours, and bilateral multiple ill-defined nodules were seen. On ultrasound, in four patients a discrete, heterogenous hypoechoic mass, in two patients multiple abscesses, in one patient bilateral multiple central hypo peripheral hyperechoic lesions, in two patients heterogeneous hypo- and hyperechoic areas together with parenchymal distortion, and in one patient irregular hypoechoic masses with tubular extensions and abscess cavities were seen. Five of the lesions were vascular on color Doppler ultrasound. On MR mammography, the most frequent finding was focal or diffuse asymmetrical signal intensity changes that were hypointense on T1W images and hyperintense on T2W images, without significant mass effect. Nodular lesions were also seen. On dynamic contrast-enhanced mammography, mass-like enhancement, ring-like enhancement, and nodular enhancement were seen. The time-intensity curves differed from patient to patient and from lesion to lesion. Conclusion: The imaging findings of idiopathic granulomatous mastitis have a wide spectrum, and they are inconclusive for differentiating malignant and benign lesions

  18. Granulomatous mastitis: radiological findings

    Energy Technology Data Exchange (ETDEWEB)

    Ozturk, M.; Mavili, E.; Kahriman, G.; Akcan, A.C.; Ozturk, F. [Depts. of Radiology, Surgery, and Pathology, Erciyes Univ. Medical Faculty, Kayseri (Turkey)

    2007-02-15

    Purpose: To evaluate the radiological, ultrasonographic, and magnetic resonance imaging (MRI) findings of idiopathic granulomatous mastitis. Material and Methods: Between April 2002 and June 2005, the mammography, ultrasound, color Doppler ultrasound, non enhanced MR, and dynamic MR findings of nine patients with the preliminary clinical diagnosis of malignancy and the final diagnosis of granulomatous mastitis were evaluated. Results: On mammography, asymmetrical focal densities with no distinct margins, ill-defined masses with spiculated contours, and bilateral multiple ill-defined nodules were seen. On ultrasound, in four patients a discrete, heterogenous hypoechoic mass, in two patients multiple abscesses, in one patient bilateral multiple central hypo peripheral hyperechoic lesions, in two patients heterogeneous hypo- and hyperechoic areas together with parenchymal distortion, and in one patient irregular hypoechoic masses with tubular extensions and abscess cavities were seen. Five of the lesions were vascular on color Doppler ultrasound. On MR mammography, the most frequent finding was focal or diffuse asymmetrical signal intensity changes that were hypointense on T1W images and hyperintense on T2W images, without significant mass effect. Nodular lesions were also seen. On dynamic contrast-enhanced mammography, mass-like enhancement, ring-like enhancement, and nodular enhancement were seen. The time-intensity curves differed from patient to patient and from lesion to lesion. Conclusion: The imaging findings of idiopathic granulomatous mastitis have a wide spectrum, and they are inconclusive for differentiating malignant and benign lesions.

  19. Feeling blue, going green and finding other attractive alternatives: a case of biphasic anaphylaxis to patent blue and a literature review of alternative sentinel node localisation methods.

    Science.gov (United States)

    Iqbal, Fahad Mujtaba; Basit, Abdul; Salem, Fathi; Vidya, Raghavan

    2015-01-01

    Patent blue dye is used for sentinel lymph node localisation in order to stage the axilla in patients with breast cancer. Patent blue is one of the most common dyes used across the UK, however, the incidence of adverse effects seems to be increasing. This case highlights our experience of a biphasic anaphylactic reaction to patent blue dye, and we conduct a brief literature review of alternative and more novel methods to adequately visualise the lymphatics for sentinel lymph node biopsy. PMID:26670899

  20. Novel method for combined linkage and genome-wide association analysis finds evidence of distinct genetic architecture for two subtypes of autism.

    OpenAIRE

    Vieland, VJ; Hallmayer, J.; Y. Huang; Pagnamenta, AT; Pinto, D; Khan, H.; Monaco, AP; Paterson, AD; Scherer, SW; Sutcliffe, JS; Szatmari, P

    2011-01-01

    The Autism Genome Project has assembled two large datasets originally designed for linkage analysis and genome-wide association analysis, respectively: 1,069 multiplex families genotyped on the Affymetrix 10 K platform, and 1,129 autism trios genotyped on the Illumina 1 M platform. We set out to exploit this unique pair of resources by analyzing the combined data with a novel statistical method, based on the PPL statistical framework, simultaneously searching for linkage and association to lo...

  1. How possible is the development of an operational psychometric method to assess the presence of the 5-HTTLPR s allele? Equivocal preliminary findings

    OpenAIRE

    Laszik Andras; Rihmer Zoltan; Fountoulakis Konstantinos N; Gonda Xenia; Akiskal Hagop S; Bagdy Gyorgy

    2010-01-01

    Abstract Objective The s allele of the 5-hydroxytryptamine transporter-linked promoter region (5-HTTLPR) polymorphism of the serotonin transporter gene has been found to be associated with neuroticism-related traits, affective temperaments and response to selective serotonin reuptake inhibitor (SSRI) treatment. The aim of the current study was to develop a psychometric tool that could at least partially substitute for laboratory testing and could predict the presence of the s allele. Methods ...

  2. Methods of Pest Control and Direct Yield Loss Assessment of Country Bean (Dolichos lablab at Farmer`s Field Condition: A Survey Finding

    Directory of Open Access Journals (Sweden)

    K.U. Ahmed

    2004-01-01

    Full Text Available A survey on farmer`s pest control methods and direct yield loss assessment of country bean (Dolichos lablab was done during September 2000 to February 2001 in North Edilpur and South Mohadebpur villages of Sitakundu under Chittagong district. Results revealed that farmers used Fanfan, Nogos, Ripcord, Malathion, Roxion and Sumithion as chemical methods and applying ash and handpicking of insect pests as non-chemical method to control insect pests. The frequency of insecticide application during flowering stage to harvest was 9 to 15 with waiting period of only 3 to 20 days and 6 to 12 with waiting period of 3 to 25 days in North Edilpur and South Mohadebpur, respectively. The pod infestation by pod borer and aphids varied from 2.29 to 5.12% and from 2.83 to7.16% in North Edilpur and South Mohadebpur, respectively. Insect pests thus caused direct yield loss of 60.38-200.69 kg ha-1 in North Edilpur and 92.63-345.80 kg ha-1 in South Mohadebpur.

  3. Tarsal coalitions: CT findings

    International Nuclear Information System (INIS)

    Purpose: To show the CT findings and the accuracy in determining the presence of osseous or figrocartilaginous tarsal coalitions. Materials and Methods: Ten CT scans performed between 5/00 and 6/01 with the diagnosis of tarsal coalitions were evaluated. The CT scans were done with a helical scanner and a multislice one, with 1 mm collimation thickness and were evaluated in the axial, coronal and sagittal plane with MPR reconstructions. Results: We identified 6 osseous coalitions, 2 cuboid-first cuneiform and 4 talocalcaneal ones and 10 fibrocartilaginous coalitions, 4 talocalcaneal and 6 calcaneonavicular ones. Conclusion: CT determines the presence of osseous bridges or the degenerative or bone deformities associated to the diagnosis of fibrocartilaginous coalitions. In complex cases, the use of MPR reconstructions helps to find the ideal plane to establish the diagnosis. Talocalcaneal coalition is best diagnosed by coronal MPR reconstruction. (author)

  4. MANAGEMENT CONTROL SYSTEM AND THE CASE OF CSR IN THE TUNISIAN INDUSTRIAL COMPANIES: WHAT FINDINGS BY THE METHOD OF STRUCTURAL EQUATION?

    Directory of Open Access Journals (Sweden)

    Hichem Dkhili

    2013-01-01

    Full Text Available This study aims to the behavior of management control; it is providing a model to the behavior of integration of social responsibility in the management control tools. This model was validated with 306 Tunisian companies in the industrial sector. Through a questionnaire, the data collected are processed using exploratory and confirmatory analysis by the methods of structural equations. The results revealed that the management control system in industrial Tunisia is facing economic responsibility. This is in response to emerging pressures of uncertainty related to the environment, and in enrolling a strategy of domination by cost. In addition, the management control system is designed as a guidance tool actions and behaviors.

  5. Matrix Organization and Merit Factor Evaluation as a Method to Address the Challenge of Finding a Polymer Material for Roll Coated Polymer Solar Cells

    DEFF Research Database (Denmark)

    Bundgaard, Eva; Livi, Francesco; Hagemann, Ole; Carlé, Jon Eggert; Helgesen, Martin; Heckler, Ilona Maria; Zawacka, Natalia Klaudia; Angmo, Dechan; Larsen-Olsen, Thue Trofod; Benatto, Gisele Alves dos Reis; Roth, Bérenger; Madsen, Morten Vesterager; Andersson, Mats; Jørgensen, Mikkel; Søndergaard, Roar R.; Krebs, Frederik C

    2015-01-01

    The results presented demonstrate how the screening of 104 light-absorbing low band gap polymers for suitability in roll coated polymer solar cells can be accomplished through rational synthesis according to a matrix where 8 donor and 13 acceptor units are organized in rows and columns. Synthesis...... silver comb back electrode structure. The matrix organization enables fast identification of active layer materials according to a weighted merit factor that includes more than simply the power conversion efficiency and is used as a method to identify the lead candidates. Based on several characteristics...

  6. Airborne gamma ray spectrometry - An efficient method for finding and mapping pollution with radioactive elements from uranium extraction and ore mining

    International Nuclear Information System (INIS)

    The concentration of uranium (by radium), thorium and potassium (by the isotope K-40) in the 50 cm surface layer can be defined with relative high precision by the airborne gamma spectrometric surveys. It is well known that certain ore mining and extraction of non-radioactive ores create polluted areas. Pollution can generate from geochemical migration of uranium (radium) and its transport by surface or underground waters. Considerable pollution can be obtained with the so-called ''geochemical barriers'', generated from the change of physical-chemical properties in the surface layer. Accumulations of uranium are formed close to such barriers. There are, of course, other mechanism of radioactive pollution, from mechanical carriage of rock masses, with uranium concentration, to settling of uranium from radioactive waters in the flooded plains. Bulgaria is rich in geological formations of various uranium concentrations, sometimes very high, and we should accept it as variations of the natural radioactive background. This paper explains one of the methods used for eliminating the natural radioactive background when mapping the pollution from the ore mining industry. The example is the Buhovo area and the method described is the airborne gamma ray spectrometry. Information is also provided on the spectrometer KS 16, developed with Bulgarian and Canadian expertise. (author)

  7. Servicemembers and veterans with major traumatic limb loss from Vietnam war and OIF/OEF conflicts: Survey methods, participants, and summary findings

    Directory of Open Access Journals (Sweden)

    Charles Maynard, PhD

    2010-08-01

    Full Text Available Care of veterans and servicemembers with major traumatic limb loss from combat theaters is one of the highest priorities of the Department of Veteran Affairs. We achieved a 62% response rate in our Survey for Prosthetic Use from 298 Vietnam war veterans and 283 servicemembers/veterans from Operation Iraqi Freedom/Operation Enduring Freedom (OIF/OEF who sustained major traumatic limb loss. Participants reported their combat injuries; health status; quality of life; and prosthetic device use, function, rejection, and satisfaction. Despite the serious injuries experienced, health status was rated excellent, very good, or good by 70.7% of Vietnam war and 85.5% of OIF/OEF survey participants. However, many health issues persist for Vietnam war and OIF/OEF survey participants(respectively: phantom limb pain (72.2%/76.0%, chronic back pain (36.2%/42.1%, residual-limb pain (48.3%/62.9%, prosthesis-related skin problems (51.0%/58.0%, hearingloss (47.0%/47.0%, traumatic brain injury (3.4%/33.9%, depression (24.5%/24.0%, and posttraumatic stress disorder (37.6%/58.7%. Prosthetic devices are currently used by 78.2% of Vietnam war and 90.5% of OIF/OEF survey participants to improve function and mobility. On average, the annual rate for prosthetic device receipt is 10.7-fold higher for OIF/OEF than for Vietnam war survey participants. Findings from this cross-conflict survey identify many strengths in prosthetic rehabilitationfor those with limb loss and several areas for future attention.

  8. Gradenigo's syndrome: imaging findings

    International Nuclear Information System (INIS)

    The Gradenigo's syndrome is characterized by unilateral palsy of the abducens nerve (6th cranial nerve), retrorbirtary deep pain and otitis. Objective: present the imaging studies of a patient with the disease. Methods: a patient with Gradeningo's syndrome studied with, images of magnetic resonance and computerized tomography with imaging findings like alteration of the intensity of signal of the left petrous apex, occupation by inflammatory material of the mastoid cavities and bony litic injury at level of petrous apex, classically described. Conclusion: the imaging studies (IRM and CT) are of special aid in the detection of the clinical Gradenigo's syndrome as well as in the control of their evolution

  9. A Fast and Stable Cluster Labeling Method for Support Vector Clustering

    Directory of Open Access Journals (Sweden)

    Huina Li

    2013-12-01

    Full Text Available Even though support vector clustering (SVC is able to handle arbitrary cluster shapes effectively, its popularity is frequently degraded by highly intensive time complexity, poor label performance and even instability for efficiency. To overcome such problems, a fast and stable cluster labeling (FSCL method is proposed. Based on stable equilibrium points, the FSCL first finds an appropriate division of support vectors. With a nonlinear sample sequence strategy presented here, the connected components profiled by support vectors (SVs can be determined in terms of sampling all stable equilibrium point pairs; and the FSCL prefers a density centroid constructed by one subset of SVs, along with a stable equilibrium point, to represent a component while avoiding local optimization. Finally, the remaining data points can be assigned the label of the nearest components with respect to a weighted distance. Time complexity analysis and comparative experiments suggest that the FSCL improves both the efficiency and clustering quality significantly while guaranteeing stability.  

  10. Form finding and analysis of extensible membranes attached to 2-D and 3-D frames intended for micro air vehicles via experimentally validated finite element methods

    Science.gov (United States)

    Abudaram, Yaakov Jack

    This work is concerned with a new method to apply consistent and known pretension to silicone rubber membranes intended for micro air vehicles as well as an understanding in the science of developed pre-tension in membranes constrained by 2- D and 3-D frames and structures. Pre-tension has a marked effect on the static and dynamic response of membrane wings and controls the overall deflections, as such control and measurement of the membrane pre-tension is important. Two different 2-D frame geometries were fabricated to evaluate the technique. For open-cell frames, the pretension was not uniform, whereas it was for closed-cell frames. Results show developed full-field stress and strain fields as a function of membrane attachment temperature and frame geometry along with experimental iterations to prove repeatability. The membranes can be stretched to a specific pretension according to the temperature at which it adheres to frames. Strain fields in membranes attached to 3-D frames at various temperatures are modeled through FEA utilizing Abaqus to be able to predict the developed membrane deformations, stresses, and strains. Rigid frames with various curvatures are built via appropriate molds and then adhered to silicone rubber membranes and elevated to various temperatures to achieve different pre-strains for experimental validation. Additional experiments are conducted for more complex frame geometries involving both convex and concave topologies embedded within frames. Results are then compared with the Abaqus outputs to validate the accuracy of the FEA model. Highly compliant wings have been used for MAV platforms, where the wing structure is determined by some combination of carbon fiber composites and a membrane skin, adhered in between the layers of composite material. Another new technique of attaching membranes firmly on wing structures is introduced, which involves the application of a technology known as corona treatment coupled with another method of tensioning silicone membranes on any given frame geometry. Corona treatment provided a means of increasing adhesion of silicone on carbon fiber through the use of a high-frequency high-voltage air plasma discharge. The silicone membrane is co-cured with carbon fiber under vacuum pressure at an elevated temperature. After cool down, the membrane is tensioned.

  11. Matrix Organization and Merit Factor Evaluation as a Method to Address the Challenge of Finding a Polymer Material for Roll Coated Polymer Solar Cells

    DEFF Research Database (Denmark)

    Bundgaard, Eva; Livi, Francesco

    2015-01-01

    The results presented demonstrate how the screening of 104 light-absorbing low band gap polymers for suitability in roll coated polymer solar cells can be accomplished through rational synthesis according to a matrix where 8 donor and 13 acceptor units are organized in rows and columns. Synthesis of all the polymers corresponding to all combinations of donor and acceptor units is followed by characterization of all the materials with respect to molecular weight, electrochemical energy levels, band gaps, photochemical stability, carrier mobility, and photovoltaic parameters. The photovoltaic evaluation is carried out with specific reference to scalable manufacture, which includes large area (1 cm 2 ), stable inverted device architecture, an indium-tin-oxide-free fully printed flexible front electrode with ZnO/PEDOT:PSS (poly(3,4-ethylenedioxythiophene):polystyrene sulfonate), and a printed silver comb back electrode structure. The matrix organization enables fast identification of active layer materials according to a weighted merit factor that includes more than simply the power conversion efficiency and is used as a method to identify the lead candidates. Based on several characteristics included in the merit factor, it is found that 13 out of the 104 synthesized polymers outperformed poly(3-hexylthiophene) under the chosen processing conditions and thus can be suitable for further development.

  12. How possible is the development of an operational psychometric method to assess the presence of the 5-HTTLPR s allele? Equivocal preliminary findings

    Directory of Open Access Journals (Sweden)

    Laszik Andras

    2010-05-01

    Full Text Available Abstract Objective The s allele of the 5-hydroxytryptamine transporter-linked promoter region (5-HTTLPR polymorphism of the serotonin transporter gene has been found to be associated with neuroticism-related traits, affective temperaments and response to selective serotonin reuptake inhibitor (SSRI treatment. The aim of the current study was to develop a psychometric tool that could at least partially substitute for laboratory testing and could predict the presence of the s allele. Methods The study included 138 women of Caucasian origin, mean 32.20 ± 1.02 years old. All subjects completed the Hungarian standardised version of the Temperament Evaluation of the Memphis, Pisa, Paris, and San Diego Autoquestionnaire (TEMPS-A instrument and were genotyped for 5-HTTLPR using PCR. The statistical analysis included the calculation of the Index of Discrimination (D, Discriminant Function Analysis, creation of scales on the basis of the above and then item analysis and calculation of sensitivity and specificity. Results Four indices were eventually developed, but their psychometric properties were relatively poor and their joint application did not improve the outcome. Conclusions We could not create a scale that predicts the 5-HTTLPR genotype with sufficient sensitivity and specificity, therefore we could not substitute a psychometric scale for laboratory genetic testing in predicting genotype, and also possibly affective disorder characterisation and treatment.

  13. Two methods to estimate the position resolution for straw chambers with strip readout

    International Nuclear Information System (INIS)

    The centroid and charge-ratio methods are presented to estimate the position resolution of the straw chambers with strip readout. For the straw chambers of 10 mm in diameter, the highest position resolution was obtained for a strip pitch of 5 mm. With the centroid method and perpendicular X-ray beam, the position resolution was ?120 ?m, for the signal-to-noise ratio of 60-65. The charge-ratio method has demonstrated ?10% better position resolution at the edges of the strip. 6 refs.; 5 figs

  14. Two methods to estimate the position resolution for straw chambers with strip readouts

    International Nuclear Information System (INIS)

    The centroid and charge-ratio methods are used to investigate the position resolutions of a new kind of gas detector: A straw chamber with a strip readout. The methods are simple and give the same resolution. The charge-ratio method is not sensitive to the pedestal subtraction and cross talks between the strips. (orig.)

  15. O centróide da piscina de água quente do pacífico como um indicador dos fenômenos El Niño e La Niña / The centroid of the pacific warm pool as an index for the El Niño and La Niña phenomena

    Scientific Electronic Library Online (English)

    Fabio Vieira, Machado; Victor de Amorim, d' Ávila.

    2014-09-01

    Full Text Available Os fenômenos oceanográficos El Niño e La Niña foram analisados através do monitoramento da série temporal da componente zonal do centroide da piscina de água quente do Pacífico (PAQ) que descreve movimentos leste-oeste ao longo da faixa intertropical deste oceano. Utilizou-se uma série de dados de t [...] emperatura da superfície do Oceano Pacífico para classificar a PAQ e estimar o seu centroide entre 1981 e 2003. Todos os episódios de El Niño (1982-83; 1986-87; 1990-95; e 1997-98) e La Niña (1984-85; 1988-89; 1998-2000) existentes no período analisado puderam ser observados na série temporal de dados da componente zonal da PAQ (CZPAQ). Os episódios mais intensos de El Niño foram classificados pela ordenação decrescente dos maiores deslocamentos para leste (ranking). A série de dados da CZPAQ se apresentou em fase com o índice de Oscilação Sul e com a anomalia da temperatura superficial do oceano (TSO). As flutuações associadas ao movimento zonal do centroide da PAQ foram observadas no espectro de energia onde ficaram ressaltadas as flutuações interanuais associadas aos fenômenos El Niño e La Niña. Foram observados deslocamentos mais curtos para oeste durante os anos de La Niña, quando comparados aos deslocamentos para leste durante os eventos de El Niño. A migração zonal da PAQ, representada aqui pelo centroide, apresentou-se, portanto, como um indicador dos fenômenos El Niño e La Niña. A principal vantagem dessa técnica é a dependência de um único parâmetro arbitrário, que é o limiar da TSO para delinear a PAQ. Abstract in english The El Niño -La Niña oceanographic phenomena were analized making use of the zonal component of the Pacific warm pool (PAQ) which describes east-west displacements along the intertropical belt of this ocean. We manipulated an ocean surface temperature (TSO) timeseries to classify the PAQ and to esti [...] mate its centroid between 1981 and 2003. All the El Niño (1982-83; 1986-87; 1990-95; e 1997-98) and La Niña (1984-85; 1988-89; 1998-2000) episodes described in the academic literature were eminent in the timeserie of the zonal component of the Pacific warm pool (CZPAQ). The most intense El Niño episodes were ranked according to its furthest eastward displacement. The timeserie of the CZPAQ was in phase with both the TSO anomaly and the Southern Oscillation Index. The fluctuations associated to the CZPAQ were illustraded in the spectrum where interannual oscillations associated to the El Niño -La Niña phenomena were observed. Shorter migrations to the west during the La Niña years were notable in comparison to those eastward moviments during the El Niño events. Therefore, the zonal displacements of the PAQ, represented here by the centroid, were presented as having significant worth to indicate the El Niño and La Niña phenomena. The main advantage of this technique is that it depends on a single arbitrary parameter to represent the PAQ, the threshold of the ocean surface temperature in the Pacific Ocean.

  16. Abdominal aspergillosis: CT findings

    Energy Technology Data Exchange (ETDEWEB)

    Yeom, Suk Keu, E-mail: pagoda20@hanmail.net [Department of Radiology and Research Institute of Radiology, Asan Medical Center, University of Ulsan College of Medicine, 388-1, Poongnap2-dong, Songpa-gu, Seoul, 138-736 (Korea, Republic of); Kim, Hye Jin, E-mail: kimhyejin@amc.seoul.kr [Department of Radiology and Research Institute of Radiology, Asan Medical Center, University of Ulsan College of Medicine, 388-1, Poongnap2-dong, Songpa-gu, Seoul, 138-736 (Korea, Republic of); Byun, Jae Ho, E-mail: jhbyun@amc.seoul.kr [Department of Radiology and Research Institute of Radiology, Asan Medical Center, University of Ulsan College of Medicine, 388-1, Poongnap2-dong, Songpa-gu, Seoul, 138-736 (Korea, Republic of); Kim, Ah Young, E-mail: aykim@amc.seoul.kr [Department of Radiology and Research Institute of Radiology, Asan Medical Center, University of Ulsan College of Medicine, 388-1, Poongnap2-dong, Songpa-gu, Seoul, 138-736 (Korea, Republic of); Lee, Moon-Gyu, E-mail: mglee@amc.seoul.kr [Department of Radiology and Research Institute of Radiology, Asan Medical Center, University of Ulsan College of Medicine, 388-1, Poongnap2-dong, Songpa-gu, Seoul, 138-736 (Korea, Republic of); Ha, Hyun Kwon, E-mail: hkha@amc.seoul.kr [Department of Radiology and Research Institute of Radiology, Asan Medical Center, University of Ulsan College of Medicine, 388-1, Poongnap2-dong, Songpa-gu, Seoul, 138-736 (Korea, Republic of)

    2011-03-15

    Objective: In order to retrospectively evaluate the CT findings of abdominal aspergillosis in immunocompromised patients. Materials and methods: CT scans were reviewed with regard to the sites, number, morphologic appearance, attenuation, and the contrast enhancement patterns of the lesions in six patients (5 women, 1 man; mean age, 43.4 years; range, 23-59 years) with pathologically proved abdominal aspergillosis by two gastrointestinal radiologists in consensus. Medical records were also reviewed to determine each patient's clinical status and outcome. Results: All patients were immunocompromised state: 4 patients received immunosuppressive therapy for solid organ transplantation and 2 patients received chemotherapy for acute myeloid leukemia. Aspergillosis involved blood vessels (n = 3), liver (n = 2), spleen (n = 2), gastrointestinal tract (n = 2), native kidney (n = 1), transplanted kidney (n = 1), peritoneum (n = 1), and retroperitoneum (n = 1). CT demonstrated solid organ or bowel infarction or perforation secondary to vascular thrombosis or pseudoaneurysm, multiple low-attenuating lesions of solid organs presenting as abscesses, concentric bowel wall thickening mimicking typhlitis, or diffuse or nodular infiltration of the peritoneum and retroperitoneum. Conclusion: Familiarity with findings commonly presenting as angioinvasive features or abscesses on CT, may facilitate the diagnosis of rare and fatal abdominal aspergillosis.

  17. Glossopharyngeal neuralgia: MR findings

    International Nuclear Information System (INIS)

    Objective: To investigate the possibility of MRI on visualizing the relationship between glossopharyngeal nerve and surrounding vessels, and to evaluate the significance of MRI in the diagnosis and treatment of glossopharyngeal neuralgia. Methods: MRI findings were analyzed retrospectively in 12 patients with glossopharyngeal neuralgia, and were compared with surgical findings and effect of pain relief. Results: The artery compression or contact of the glossopharyngeal entry zone, as revealed during operation in 10 patients with glossopharyngeal neuralgia, was visualized on MRI in 9 and not seen in 1. The venous compression of the glossopharyngeal entry zone was not identified on MRI in 1. The conglutinative arachnoids of the glossopharyngeal entry, zone was not visualized on MRI in 1. MRI demonstrated the affected glossopharyngeal nerve root entry zone was compressed or contacted by the posterior inferior cerebellar artery. (PICA) in 8 patients and by the vertebral artery in 1 patient. One patient's offending vessel was confirmed to be the anterior inferior cerebellar artery (AICA) by the operation, and the surgical findings were corresponded with MRI in others. Vascular compression or' contact of the affected glossopharyngeal nerve was not visualized on MRI in 3 patients, and operation confirmed that the glossopharyngeal nerve root entry zone was compressed by unknown artery in 1, by small vein in 1, and by conglutinative arachnoids in 1, respectively. Eight patients presented with symptoms of the ipsilateral trigeminal neuralgia concurrently. The compression of the affected trigeminal nerve root by superior cerebellar artery (SCA) was visualized on MRI in 6 patients, and operation did not reveal the source of artery compression in 1 and corresponded with MRI findings in other 5 cases. Vascular compression of affected trigeminal nerve was not visualized on MRI in 2 patients, and intraoperative inspection revealed that trigeminal nerve root was compressed by draining vein of brainstem in 1 and not compressed by any vessels in 1. All patient's neuralgia resolved alter microvascular decompression of glossopharyngeal nerve and trigeminal nerve. Conclusion: It is possible to visualize the glossopharyngeal and surrounding arteries on MRI, and it is of great significance in the diagnosis and treatment of this kind of glossopharyngeal neuralgia. (authors)

  18. Finding Cryptography in Object Code

    Energy Technology Data Exchange (ETDEWEB)

    Jason L. Wright

    2008-10-01

    Finding and identifying Cryptography is a growing concern in the malware analysis community. In this paper, a heuristic method for determining the likelihood that a given function contains a cryptographic algorithm is discussed and the results of applying this method in various environments is shown. The algorithm is based on frequency analysis of opcodes that make up each function within a binary.

  19. A Two-Stage Method for Scientific Papers Analysis

    Directory of Open Access Journals (Sweden)

    Damien Hanyurwimfura

    2014-10-01

    Full Text Available A considerable amount of research is being conducted by many people (researchers, graduate students, professors etc everyday. Finding information about aspecific topic is one of the most time consuming activities of those people. People doing research have to search, read and analyze multiple research papers, e-books and other documents and then determine what they contain and discover knowledge from them. Many available resources are in the form of unstructured text format of long text pages which require long time to read and analyze. In this paper we propose a two-stage method for scientific paper analysis. The method uses information extraction to extract the main idea key sentences (mainly needed by the most readers from the paper and the extracted paper’s information is then organized in a structured format and grouped in different clusters according to their topics using a multi-word based clustering method. The proposed method combines different features in paper’s topics extraction and uses multi-word matching feature in selection of initial centroids for clustering. The proposed method can help readers to access and analyze multiple research papers documents timely and efficiently. Conducted experiments show the effectiveness and usefulness of our proposed approach.

  20. Find din stemme

    DEFF Research Database (Denmark)

    Hansen, Jette Barnholdt

    Anmeldelse af Dorte Kock og Lene Kleinschmidts: Find din stemme. En brugsbog.Hans Reitzels Forlag 2010.......Anmeldelse af Dorte Kock og Lene Kleinschmidts: Find din stemme. En brugsbog.Hans Reitzels Forlag 2010....

  1. Finding beam focus errors automatically

    International Nuclear Information System (INIS)

    An automated method for finding beam focus errors using an optimization program called COMFORT-PLUS. The steps involved in finding the correction factors using COMFORT-PLUS has been used to find the beam focus errors for two damping rings at the SLAC Linear Collider. The program is to be used as an off-line program to analyze actual measured data for any SLC system. A limitation on the application of this procedure is found to be that it depends on the magnitude of the machine errors. Another is that the program is not totally automated since the user must decide a priori where to look for errors

  2. Modified nonlinearities distribution Homotopy Perturbation method as a tool to find power series solutions to ordinary differential equations / Método modificado de Perturbación Homotópica con distribución de no linealidades como herramienta para encontrar soluciones de ecuaciones diferenciales ordinarias

    Scientific Electronic Library Online (English)

    U., Filobello-Nino; H., Vázquez-Leal; Y., Khan; D., Pereyra-Díaz; A., Pérez-Sesma; A., Díaz-Sánchez; V.M., Jiménez-Fernández; A., Herrera-May; R., López-Martínez; J., Sanchez-Orea.

    Full Text Available En este artículo, el método modificado de perturbación homotópica con distribución de no linealidades (MNDHPM) es utilizado para encontrar soluciones en series de potencias de ecuaciones diferenciales ordinarias, tanto lineales como no lineales. Se verá que el método es particularmente relevante en [...] algunos casos de ecuaciones con coeficientes no polinomiales e inhomogéneas con términos no homogéneos no polinomiales. Abstract in english In this article, modified non-linearities distribution homotopy perturbation method (MNDHPM) is used in order to find power series solutions to ordinary differential equations with initial conditions, both linear and nonlinear. We will see that the method is particularly relevant in some cases of eq [...] uations with non-polynomial coefficients and inhomogeneous non-polynomial terms.

  3. Thoracic textilomas: CT findings

    Energy Technology Data Exchange (ETDEWEB)

    Machado, Dianne Melo; Zanetti, Glaucia; Araujo Neto, Cesar Augusto; Nobre, Luiz Felipe; Meirelles, Gustavo de Souza Portes; Silva, Jorge Luiz Pereira e; Guimaraes, Marcos Duarte; Escuissato, Dante Luiz; Souza Junior, Arthur Soares; Hochhegger, Bruno; Marchiori, Edson, E-mail: edmarchiori@gmail.com [Hospital Universitario Antonio Pedro (HUAP/UFF), Niteroi, RJ (Brazil)

    2014-09-15

    Objective: the aim of this study was to analyze chest CT scans of patients with thoracic textiloma. Methods: this was a retrospective study of 16 patients (11 men and 5 women) with surgically confirmed thoracic textiloma. The chest CT scans of those patients were evaluated by two independent observers, and discordant results were resolved by consensus. Results: the majority (62.5%) of the textilomas were caused by previous heart surgery. The most common symptoms were chest pain (in 68.75%) and cough (in 56.25%). In all cases, the main tomographic finding was a mass with regular contours and borders that were well-defined or partially defined. Half of the textilomas occurred in the right hemithorax and half occurred in the left. The majority (56.25%) were located in the lower third of the lung. The diameter of the mass was ≤ 10 cm in 10 cases (62.5%) and > 10 cm in the remaining 6 cases (37.5%). Most (81.25%) of the textilomas were heterogeneous in density, with signs of calcification, gas, radiopaque marker, or sponge-like material. Peripheral expansion of the mass was observed in 12 (92.3%) of the 13 patients in whom a contrast agent was used. Intraoperatively, pleural involvement was observed in 14 cases (87.5%) and pericardial involvement was observed in 2 (12.5%). Conclusions: it is important to recognize the main tomographic aspects of thoracic textilomas in order to include this possibility in the differential diagnosis of chest pain and cough in patients with a history of heart or thoracic surgery, thus promoting the early identification and treatment of this postoperative complication. (author)

  4. Thoracic textilomas: CT findings

    International Nuclear Information System (INIS)

    Objective: the aim of this study was to analyze chest CT scans of patients with thoracic textiloma. Methods: this was a retrospective study of 16 patients (11 men and 5 women) with surgically confirmed thoracic textiloma. The chest CT scans of those patients were evaluated by two independent observers, and discordant results were resolved by consensus. Results: the majority (62.5%) of the textilomas were caused by previous heart surgery. The most common symptoms were chest pain (in 68.75%) and cough (in 56.25%). In all cases, the main tomographic finding was a mass with regular contours and borders that were well-defined or partially defined. Half of the textilomas occurred in the right hemithorax and half occurred in the left. The majority (56.25%) were located in the lower third of the lung. The diameter of the mass was ≤ 10 cm in 10 cases (62.5%) and > 10 cm in the remaining 6 cases (37.5%). Most (81.25%) of the textilomas were heterogeneous in density, with signs of calcification, gas, radiopaque marker, or sponge-like material. Peripheral expansion of the mass was observed in 12 (92.3%) of the 13 patients in whom a contrast agent was used. Intraoperatively, pleural involvement was observed in 14 cases (87.5%) and pericardial involvement was observed in 2 (12.5%). Conclusions: it is important to recognize the main tomographic aspects of thoracic textilomas in order to include this possibility in the differential diagnosis of chest pain and cough in patients with a history of heart or thoracic surgery, thus promoting the early identification and treatment of this postoperative complication. (author)

  5. Finding the Needles in the Haystacks: Feasibility of Exomoon Detection and Spectral Recovery

    Science.gov (United States)

    Jansen, Tiffany C.; Roberge, Aki; Agol, Eric; Stark, Chris; Robinson, Tyler; Haystacks Team

    2016-01-01

    Although nearly two thousand exoplanets have been discovered and confirmed to date, exomoons have yet to be detected orbiting these planets. The detection of an exomoon would give insight into planetary formation and possibly increase the habitable real estate in a planetary system. Current telescopes are not capable of spatially resolving an exoplanet and its exomoon, or of separating the two blended spectra in a combined light measurement. However, previous work has shown that there is a wavelength dependent photometric centroid shift between a planet and its moon due to the weighted nature of the center of light (Agol et al. 2015). This spectroastrometric shift is highest in bands where the planet is dim and the moon is relatively bright, which can happen if it differs compositionally from its planet.As part of the "Finding the Needles in the Haystacks" project, we generated a realistic spatial / spectral model of an Earth-like exomoon orbiting a warm Jupiter in the habitable zone of a Sun-like star, including plausible exozodiacal dust structure. Preliminary results show that the presence of an Earth-like exomoon can produce centroid shifts greater than a milliarcsecond at some wavelengths, enabling the detection of the Earth-like exomoon even in the presence of dust. However, extracting the spectrum of the Earth-like exomoon proved challenging, even when employing a simple telescope simulation devoid of coronagraphic effects, and further work will be needed to determine if it is possible even with 12-meter-class space telescopes.

  6. An Optimized Hybrid Approach for Path Finding

    OpenAIRE

    Ansari, Ahlam; Sayyed, Mohd Amin; Ratlamwala, Khatija; Shaikh, Parvin

    2015-01-01

    Path finding algorithm addresses problem of finding shortest path from source to destination avoiding obstacles. There exist various search algorithms namely A*, Dijkstra's and ant colony optimization. Unlike most path finding algorithms which require destination co-ordinates to compute path, the proposed algorithm comprises of a new method which finds path using backtracking without requiring destination co-ordinates. Moreover, in existing path finding algorithm, the number of iterations req...

  7. Fact Finding Nuclear Energy; Fact Finding Kernenergie

    Energy Technology Data Exchange (ETDEWEB)

    Scheepers, M.J.J.; Seebregts, A.J.; Lako, P. [ECN-Beleidsstudies, Petten (Netherlands); Blom, F.J.; Van Gemert, F. [Sociaal-Economische Raad SER, Den Haag (Netherlands)

    2007-09-15

    Facts and figures on nuclear energy are presented to enable a discussion on the role of nuclear power in the transition to a sustainable energy supply for the Netherlands. The following issues are presented: Nuclear technology, safety and security (including non-proliferation and protection against terrorism); Environmental aspects (including greenhouse gas emissions of the nuclear energy lifecycle); Nuclear power and the power market (including impact of nuclear power on electricity market prices); Economic aspects (including costs of nuclear power and external costs and benefits); Policy issues (including sustainable development); Social acceptance of nuclear energy; Knowledge infrastructure for nuclear energy in the Netherlands; and Nuclear power in long term energy scenarios for the Netherlands and Europe. Using two long-term energy scenarios the report also presents a social impact analysis of an increasing share of nuclear power in the Dutch electricity supply. [Dutch] In dit onderzoek zijn feiten en gegevens over kernenergie verzameld op basis van bestaande inzichten en een veelheid aan literatuur (fact finding). Voor technologische expertise heeft ECN zich laten bijstaan door de Nucleair Research and consultancy Group (NRG). Op basis van de fact-finding studie bereidt de SER een advies voor over de rol van kernenergie in de toekomstige nationale elektriciteitsproductie. In de eerste acht hoofdstukken worden feiten en gegevens gepresenteerd over verschillende onderwerpen die bij kernenergie van belang zijn. In Hoofdstuk 2 wordt de kernenergietechnologie beschreven, inclusiefde veiligheid van kernenergie besproken, omdat die nauw met de technologie samenhangt. Hierbij gaat het om de technische veiligheid van de installaties, maar ook om beveiliging tegen misbruik van technologie en nucleair materiaal, waaronder beveiliging tegen terrorisme. De milieuaspecten door radioactiviteit en door emissies van kooldioxide die met het gebruik van kernenergie samenhangen worden in Hoofdstuk 3 besproken. In hoofdstuk 4 wordt eerst uitgelegd hoe de elektriciteitsprijs in een geliberaliseerde elektriciteitsmarkt tot stand komt en wordt nagegaan of uitbreiding van het productievermogen met kernenergie daar invloed op zou kunnen hebben. Ook wordt de concurrentie met andere elektriciteitsproductietechnologieen besproken. Verder komen mededingingsaspecten aan de orde en inpassing in het Nederlandse elektriciteitssysteem. In Hoofdstuk 5 wordt een overzicht gegeven van kosteninformatie over kernenergie. Daarnaast wordt de economische rentabiliteit van kernenergie besproken, evenals externe kosten en baten. In Hoofdstuk 6 wordt eerst ingegaan op de vraag aan welke voorwaarden kernenergie moet voldoen om een rol te kunnen spelen in (een overgangsfase naar) een duurzame energievoorziening. Hierna wordt de rol van de overheid besproken bij het maken van keuzes over voorwaarden van kernenergie en het vertalen daarvan in wet- en regelgeving. Ook wordt een overzicht gegeven van het kernenergiebeleid in een aantal andere Europese landen. Hoofdstuk 7 gaat over maatschappelijke acceptatie en bespreekt hoe risicoperceptie van kernenergie wordt onderzocht. Daarnaast worden resultaten gepresenteerd van onderzoek naar opvattingen en meningen van de bevolking over kernenergie. In Hoofdstuk 8 wordt de Nederlandse kennisinfrastructuur op het gebied van kernenergie beschreven, alsmede de nucleaire kennis bij de overheid en de toekomstige kennisinfrastructuur. Hoofdstuk 9 geeft een overzicht van verschillende Nederlandse en Europese lange termijn toekomstscenario's voor de elektriciteitsvoorziening en de rol die kernenergie daarin kan spelen. Om een beeld te kunnen geven van mogelijke maatschappelijke gevolgen van uitbreiding van kernenergie in Nederland, is een maatschappelijke impact analyse uitgevoerd. Een dergelijke analyse beschrijft op systematische wijze de mogelijke economische en sociale effecten van een nieuwe kerncentrale en de effecten op het milieu. De resultaten van deze analyse worden beschreven in Hoofdstuk 10. Bij de analyse is gebru

  8. Dermoscopic findings in cicatricial alopecia

    Directory of Open Access Journals (Sweden)

    Seher Ar?

    2013-12-01

    Full Text Available Background: Dermoscopy is an important tool for the diagnosis of pigmented skin lesions. Newly, this method has also been used in the diagnosis and follow-up hair and scalp disorders. Objective: The objective of this study was to investigate dermoscopic findings in a sample of patients with clinical and histopathological compatible with cicatricial alopecia. Methods: Twenty nine patients with cicatricial alopecia diagnosed by clinical and histological findings were examined by dermoscopy.. Results: Dermoscopic features evaluated included folliculitis decalvans (n=8, pseudopelade of Brocq (n=7, lichen planopilaris (n=6, discoid lupus erythematosus (n=2, dissecting cellulitis (n=1, and secondary cicatricial alopecia (n=5. Visualization of structures previously examined with naked eye were seen in great detail with dermoscopy. The loss of follicular orifices was seen in all patients with cicatricial alopecia. Perifollicular scaling, arborizing red lines, honeycomb pigment pattern, white dots and tufted hairs were the other most obvious findings. Conclusion: Use of dermoscopy in the clinical evaluation of cicatrical alopecia improves diagnostic capability beyond simple clinic inspection, but larger studies correlating dermoscopic findings with histopathology exams are needed to improve understanding of this method.

  9. Finding Activities You Enjoy

    Science.gov (United States)

    ... choose physical activities that match your interests! Love music? Take dancing lessons. Sign up for an aerobics ... and flexibility. The variety helps keep things interesting! Download the Tip Sheet Finding Activities You Enjoy (PDF, ...

  10. Find a Hematologist

    Science.gov (United States)

    ... Patients Find a Hematologist First Name: Last Name: Company: City: State: (Select) Armed Forces Americas Armed Forces ... Image Bank Advocacy Action Alerts Policy News Advocacy Leadership Institute Policy Statements Testimony & Correspondence Meetings ASH Annual ...

  11. Hysterosalpingographic findings in infertility

    International Nuclear Information System (INIS)

    Four hundred and fifty four cases of H.S.G. in infertility were analyzed and following brief results were obtained. 1. Most frequent age group was 25-29 year old, and those number of patient were 188 (41.4%). 2. Most frequent abnormal uterine findings was intravasation (113 cases), and malposition (119), irregular margin (104), filling defect (37), and diverticulum (6) in decreasing order. 3. Most frequent abnormal tubal finding was obstruction (199 cases), and hydrosalpinx (99), diverticulosis (22), intravasation (17), peritubal adhesion (13), and beaded tube (10) in decreasing order. 4. Nagative findings was seen in 155 cases (34.1%) of uterus and in 227 cases (50.0%) of fallopian tubes. 5. Nagative findings in both uterus and fallopian tubes was seen only 87 cases (19.2%)

  12. Find a Dermatologic Surgeon

    Science.gov (United States)

    ... for Every Season How to Choose the Best Skin Care Products In This Section Dermatologic Surgery What is dermatologic ... for Every Season How to Choose the Best Skin Care Products Find a Dermatologic Surgeon Please select the following ...

  13. Find a Dermatologist

    Science.gov (United States)

    ... Virgin Islands, U.S. Yemen Zimbabwe Doctor's Last Name: City: State: Choose a State Alabama Alaska Arizona Arkansas ... cancer screening . Use these tips to Be Sun Smart ® . Get the scoop on dermatologists' top tips. Find ...

  14. Finding Maximal Quasiperiodicities in Strings

    DEFF Research Database (Denmark)

    Brodal, Gerth Stølting; Pedersen, Christian N. S.

    2000-01-01

    Apostolico and Ehrenfeucht defined the notion of a maximal quasiperiodic substring and gave an algorithm that finds all maximal quasiperiodic substrings in a string of length n in time O(n log2 n). In this paper we give an algorithm that finds all maximal quasiperiodic substrings in a string of length n in time O(n log n) and space O(n). Our algorithm uses the suffix tree as the fundamental data structure combined with efficient methods for merging and performing multiple searches in search tree...

  15. CT findings of colonic diverticulitis

    Energy Technology Data Exchange (ETDEWEB)

    Sasaki, Shigeru; Ohba, Satoru [Nagoya City Univ. (Japan). Medical School; Mizutani, Masaru [and others

    1998-11-01

    Although colonic diverticulitis has no indication for operation, but in some mistaken cases were operated with a diagnosis of acute appendicitis. We evaluated the CT findings of colonic diverticulitis about 19 cases and of asymptomatic colonic diverticula about 15 cases retrospectively. Diagnosis was confirmed of barium enema and operation. CT are complementary methods of examination that can delineated the range of thickening of the colon and the extension of inflammatory changes around the colon. We also believe that CT findings of colonic diverticulitis are useful for differentiating from a diagnosis of appendicitis. (author)

  16. Learning as way-finding

    DEFF Research Database (Denmark)

    Dau, Susanne

    This paper is based on case study findings from studying undergraduate students’ perceptions of their navigation in a blended learning environment where different learning spaces are offered. In this paper learning is regarded as a multi-level and multi complex concept. In this regard the concept...... assumptions, is based on the findings from research of the implementation of blended learning in two undergraduate programmes at University College North in Denmark. The data collection methods is based on eighteen focus-group interview collected in a period of the first two years of students enrolment in...... themes around plots in a narrative form. The findings reveal that students’ use of different learning spaces are challenged by inhabited and embodied practices as well as disruptions. It is argued that learning must be viewed in the light of the new technological possibilities and challenges in spaces...

  17. Radiologic findings of emphysematous pyelonephritis

    International Nuclear Information System (INIS)

    Emphysematous pyelonephritis is a rare, life threatening infection of kidney and the perinephric space, characterized by the production of gas within the renal parenchyma. The aim of this study is to analyze the clinical and radiologic characteristics of emphysematous pyelonephritis. We reviewed 7 cases of the emphysematous pyelonephritis. Six patients had plain abdominal radiographs, ultrasonograms and abdominal CT scans. Only one patient had plain radiograph and ultrasonogram. In 5 operated cases, CT findings were compared with surgical records. Plain radiographs showed characteristic diffuse mottling of gas in renal fossa. On sonogram, intrarenal gas was identified as echogenic foci with dirty shadows. CT scan showed inflammatory mass with gas and fluid levels in adjacent to the kidney. CT findings corresponded relatively wall with the surgical findings in regard to disease extent. Intrarenal gas in appropriate clinical setting is highly specific for emphysematous pyelonephritis. CT is the most sensitive method for demonstrating the disease extent as well as specific diagnosis

  18. Ultrasonographic findings of gynecomastia

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Ji Hyung; Oh, Ki Keun; Yoon, Choon Sik; Park, Chang Yun [Yongdong Severance Hospital, Seoul (Korea, Republic of)

    1993-12-15

    The purposes of our study were to find out characteristic ultrasonographic findings of gynecomastia and to analyze age distribution, causative factors of gynecomastia. For these purposes, medical records of 39 male patients with gynecomastia were reviewed and sonographic findings of 13 cases of gentamycin were analyzed. Gynecomastia was found most commonly in teenagers and commonly in twenties. Almostly, it occurred without any evident etiology and classified as idiopathic or pirbuterol type. Less frequently, it occurred due to drug administration, systemic disease, or male hormone deficiency. Unilateral involvement was seen in 29 cases; 17cases involving the left and 12 cases the right. Bilateral involvement was seen in 10 cases. Sonographically,gynecomastia appeared as hypoechoic or intermediate echoic mass with various shape in the subareolar area. One case showed diffuse fatty breast pattern without definable mass. On sonographic evaluation, prominent nipple should not be misinterpreted as a breast mass. For the correct diagnosis of gynecomastia, both side breasts should be evaluated for comparison

  19. CT findings of ganglioneuroma

    Energy Technology Data Exchange (ETDEWEB)

    Jeon, Tae Joo; Yoon, Choon Sik; Kim, Myung Jun; Kim, Sang Jin; Oh, Ki Keun [Yonsei Univ., College of Medicine, Seoul (Korea, Republic of)

    1998-09-01

    Ganglioneuroma is a relatively uncommon benign tumor and has no pathognomonic radiological findings;diagnosis is therefore difficult. In order to better diagnose this tumor we analysed its CT findings and pathologic correlation. Seventeen tumors in 16 patients(M:F=3D9:7) diagnosed as ganglioneuroma between 1992 and 1996 were retrospectively analysed with regard to location, size, contour, long axis of the mass, enhancement pattern, calcification, necrosis and capsulation, all as seen on CT, and compared with histo-pathologic findings. Tumors were 1.5 to 10(mean, 5.6) cm in size, and their location was mediastinal(n=3D12), cervical(n=3D2), retroperitoneal (n=3D2) or adrenal(n=3D1). Fifteen had an oval or round contour and two were dumb-bell-shaped. The long axis of the lesion was craniocaudal in 14 cases and non-specific in three. Thirteen lesions showed heterogeneous enhancement, and four homogeneous. Capsule-like enhancement was noted on CT scans in eight cases;there was no definite correlation between enhancement pattern and pathologic findings. Calcification was seen in six cases and an inner low-density lesion in two. Ganglioneuroma is a benign neurogenic tumor, occurring most frequently at the posterior mediastinum. General CT findings of this tumor are a well-defined oval shape with a variable enhancement pattern, but several cases showed focal calcification or inner low density. For accurate diagnosis of ganglioneuroma both common and uncommon findings must therefore be considered.=20.

  20. Finding optimal exact reducts

    KAUST Repository

    AbouEisha, Hassan M.

    2014-01-01

    The problem of attribute reduction is an important problem related to feature selection and knowledge discovery. The problem of finding reducts with minimum cardinality is NP-hard. This paper suggests a new algorithm for finding exact reducts with minimum cardinality. This algorithm transforms the initial table to a decision table of a special kind, apply a set of simplification steps to this table, and use a dynamic programming algorithm to finish the construction of an optimal reduct. I present results of computer experiments for a collection of decision tables from UCIML Repository. For many of the experimented tables, the simplification steps solved the problem.

  1. Antrochoanal polyp: CT findings

    Energy Technology Data Exchange (ETDEWEB)

    Juhng, Seon Kwan; Lee, Kyoung Soo; Kim, Chang Guhn; Won, Jong Jin; Jang, Chul Ho [Wonkwang University School of Medicine, Iksan (Korea, Republic of)

    1992-07-15

    An antrochoanal polyp is a solitary polypoid mass that arises from the maxillary sinus, and protrudes through the natural ostium into the middle meatus, and reaches the choana. The polyp does not differ histologically from an ordinary nasal polyp, which is composed of edematous, hyperplastic submucosal connective tissue stroma, and is relatively hypocellular. In this sequence of events, its computed tomographic(CT) findings are characteristic. We retrospectively analyzed CT studies of nine cases, all of which showed similar CT findings: a solitary, homogeneous, hypodense mass without bony destruction that extends from the maxillary sinus through the widened ostium into choana.

  2. Antrochoanal polyp: CT findings

    International Nuclear Information System (INIS)

    An antrochoanal polyp is a solitary polypoid mass that arises from the maxillary sinus, and protrudes through the natural ostium into the middle meatus, and reaches the choana. The polyp does not differ histologically from an ordinary nasal polyp, which is composed of edematous, hyperplastic submucosal connective tissue stroma, and is relatively hypocellular. In this sequence of events, its computed tomographic(CT) findings are characteristic. We retrospectively analyzed CT studies of nine cases, all of which showed similar CT findings: a solitary, homogeneous, hypodense mass without bony destruction that extends from the maxillary sinus through the widened ostium into choana

  3. Neuroimaging findings in movement disorders

    International Nuclear Information System (INIS)

    Full text: Neuroimaging methods are of great importance for the differential diagnostic delimitation of movement disorders associated with structural damage (neoplasms, ischemic lesions, neuroinfections) from those associated with specific pathophysiological mechanisms (dysmetabolic disorders, neurotransmitter disorders). Learning objective: Presentation of typical imaging findings contributing to nosological differentiation in groups of movement disorders with similar clinical signs. In this presentation are discussed neuroimaging findings in Parkinson‘s disease, atypical parkinsonian syndromes (multiple system atrophy, progressive supranuclear palsy, corticobasal degeneration), parkinsonism in genetically mediated diseases (Wilson’s disease, pantothenate kinase-associated neurodegeneration – PKAN), vascular parkinsonism, hyperkinetic movement disorders (palatal tremor, Huntington‘s chorea, symptomatic chorea in ischemic stroke and diabetes, rubral tremor, ballismus, hemifacial spasm). Contemporary neuroimaging methods enable support for diagnostic and differential diagnostic precision of a number of hypo- and hyperkinetic movement disorders, which is essential for neurological clinical practice

  4. CT findings of necrotizing jejunitis

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Pyo Nyun; Lee, Kyung Soo; Bae, Won Kyung; Kim, Il Young; Lee, Byoung Ho [College of Medicine, Soonchunhyang Univ., Chunan (Korea, Republic of)

    1990-07-15

    Necrotizing enterocolitis, which is localized only in the jejunum, is very rare and this entity cannot be found in the English medical literature. We report the computed tomographic(CT) findings of necrotizing jejunitis in a 45-year-old man, which showed ring like and mottled air shadows between the contrast filled bowel lumen and its wall, dirty mesenteric fat and prominent mesenteric vascular enhancement. We regard CT is a useful diagnostic method of necrotizing jejunitis.

  5. Helium leak finding plant

    International Nuclear Information System (INIS)

    The invention concerns a helium leak finding plant with a mass spectrometer cell on the suction side of a molecular pump and a mechanical pre-pump, where a test sample or a test sensor is connected between the two pumps. The mechanical pre-pump consists of three successive stages. (orig./HP)

  6. Finding Distinct Subpalindromes Online

    OpenAIRE

    Kosolobov, Dmitry; Rubinchik, Mikhail; Arseny M. Shur

    2013-01-01

    We exhibit an online algorithm finding all distinct palindromes inside a given string in time $\\Theta(n\\log|\\Sigma|)$ over an ordered alphabet and in time $\\Theta(n|\\Sigma|)$ over an unordered alphabet. Using a reduction from a dictionary-like data structure, we prove the optimality of this algorithm in the comparison-based computation model.

  7. Find a Therapist

    Science.gov (United States)

    ... Helping Children and Teens With Anxiety Disorders and Depression Treatment FAQs Tips for Parents and Caregivers Help Your Child Manage Traumatic Events Anxiety Disorders at School School Refusal Test Anxiety News and Research College Students Facts Find Help Tips News and Research Resources ...

  8. Tooth Tutoring: The Findings.

    Science.gov (United States)

    Cone, Richard; And Others

    Findings are reported on a three year cross-age tutoring program in which undergraduate dental hygiene students and college students from other disciplines trained upper elementary students to tutor younger students in the techniques of dental hygiene. Data includes pre-post scores on the Oral Hygiene Index of plaque for both experimental and…

  9. Vertebral sarcoidosis: imaging findings

    Energy Technology Data Exchange (ETDEWEB)

    Poyanli, A.; Sencer, S.; Acunas, B. [Dept. of Radiology, Istanbul Medical Faculty, Istanbul (Turkey); Poyanli, O.; Akan, K. [Department of Orthopaedics and Traumatology, Goeztepe SSK Educational Hospital, Istanbul (Turkey); Sayrak, H. [Department of Pathology, Goeztepe SSK Educational Hospital, Istanbul (Turkey)

    2000-01-01

    Sarcoidosis is a multisystemic disease of unknown aetiology characterised by noncaseating granulomatous inflammation with varying presentation and prognosis. Osseous disease reported in 1-13 % of cases commonly involves hands and feet; however, vertebral sarcoidosis is rare. This report describes the radiologic, CT, MRI and radionuclide imaging findings of vertebral involvement of a case with sarcoidosis. (orig.)

  10. Finding Initial Parameters of Neural Network for Data Clustering

    Directory of Open Access Journals (Sweden)

    Suneetha Chittineni

    2013-04-01

    Full Text Available K-means fast learning artificial neural network (K-FLANN algorithm begins with the initialization oftwoparameters vigilance and tolerance which are the key to get optimal clustering outcome. The optimizationtask is to change these parameters so a desired mapping between inputs and outputs (clusters of the K-FLANN is achieved. This study presents finding thebehavioral parameters of K-FLANN that yield goodclustering performance using an optimization methodknown as Differential Evolution. DE algorithm is asimple efficient meta-heuristic for global optimization over continuous spaces. The K-FLANN algorithmismodified to select winning neuron (centroid for adata member in order to improve the matching rate frominput to output. The experiments were performed toevaluate the proposed work using machine learningartificial data sets for classification problems and synthetic data sets. The simulation results haverevealedthat optimization of K-FLANN has given quite promising results in terms of convergence rate and accuracywhen compared with other algorithms. Also the comparisons are made between K-FLANN and modified K-FLANN.

  11. Infecção pelo Papilomavírus Humano em Adolescentes: Relação com o Método Anticoncepcional, Gravidez, Fumo e Achados Citológicos / Human Papillomavirus Infection in Adolescents: Relation to Contraceptive Method, Pregnancy, Smoking, and Cytologic Findings

    Scientific Electronic Library Online (English)

    Eddie Fernando Candido, Murta; Maria Azniv Hazarabedian de, Souza; Sheila Jorge, Adad; Edward, Araújo Júnior.

    2001-05-01

    Full Text Available Objetivo: avaliar a influência da gravidez, do hábito de fumar, do método anticoncepcional e quais os achados citológicos mais freqüentes em adolescentes com infecção pelo HPV. Métodos: foram analisadas retrospectivamente 54.985 citologias de pacientes atendidas entre julho de 1993 e dezembro de 199 [...] 8. Deste total, 6.498 exames (11,8%) eram de pacientes com idade inferior a 20 anos, sendo que 326 (5,9%) apresentavam sinais citológicos de infecção por HPV, associada ou não a neoplasia intra-epitelial cervical (NIC) grau I. O grupo controle foi composto por 333 pacientes na mesma faixa etária, sem sinais citológicos de infecção por HPV. Resultados: a infecção pelo HPV foi mais freqüente nas adolescentes que fazem uso de anticoncepcionais orais (16,9% versus 13,8%, p Abstract in english Purpose: to evaluate the influence of pregnancy, habit of smoking, and the contraceptive method in HPV infection and the frequency of cytologic findings in adolescent women with HPV infection. Methods: a total of 54,985 cytologic examinations of patients seen between July, 1993 and December, 1998 we [...] re retrospectively analyzed. Of this total, 6,498 (11.8%) examinations were from patients under 20 years old. Of the total of 6,498 cytologic examinations, 326 (5.9%) presented signs of HPV infection, with or without grade I cervical intraepithelial neoplasia (CIN). Patients with diagnosis of grade II and III CIN were excluded. The control group consisted of 333 patients paired by age, without cytological signs of HPV infection. Results: in adolescents, HPV infection was more frequent in oral contraceptive users (16.9% versus 13.8%, p

  12. Gallstone ileus: CT findings

    Energy Technology Data Exchange (ETDEWEB)

    Delabrousse, E.; Bartholomot, B.; Sohm, O.; Kastler, B. [Dept. of Radiology A, CHU Jean Minjoz, University of Besancon (France); Wallerand, H. [Dept. of Surgery, CHU Jean Minjoz, University of Besancon (France)

    2000-06-01

    Gallstone ileus is a rare complication of recurrent gallstone cholecystitis. The classic radiographic triad of small bowel obstruction, pneumobilia and ectopic gallstone on abdominal plain radiograph is described with CT imaging. Because of the better resolution of CT compared with abdominal radiography and its recent accession to emergency use, radiologists should be aware of CT findings of gallstone ileus. We report a case in which gallstone ileus was initially diagnosed by CT. (orig.)

  13. Heterotopic pregnancy: Sonographic findings

    International Nuclear Information System (INIS)

    To evaluate the sonographic findings of the heterotopic pregnancy which is increasing recently. Thirty-nine cases of heterotopic pregnancy after ovulation induction and IVF-ET (In Vitro Fertilization-Embryo Transfer) during the recent 3 years were analyzed. They were diagnosed by ultrasonography and proved surgically afterwards. Sonographic findings were analyzed focusing on gestational week of intrauterine pregnancy and location of ectopic pregnancy. In particular, adnexal mass was evaluated with regard to size and the characteristic findings such as ectopic gestational sac (echogenic ring). Also, overian cyst and fluid collection in cul-de-sac space were reviewed carefully. Heterotopic pregnancy was proved surgically by salpingectomy in 33 cases and by resection of cornus in six cases. Sonographic diagnosis using transvaginal ultrasound was made from five weeks to nine weeks two days (six weeks and four days in average) from last menstral period in all 39 cases. Ectopic pregnancy was identified in ampullary part in 29 cases, in the isthmic portion of tube in four cases and in the cornus of uterus in six cases. The intrauterine pregnancy was diagnosed by identifying the intrauterine gestational saccontaining a yolk sac in seven cases and the embryo with fetal heart beat in the remaining 32 cases. Adnexal masses of heterotopic pregnancy were less than 3 cm in diameter in 2 cases (57%), 3-4 cm in 11 cases (28%) and more than 4 cm in 6 cases (15%). A characteristic finding of ectopic mass was echogenic ring which was visible in 33 (84.6%) cases by transvaginal ultrasound. Six cases had pelvic hematosalpinx and two had pelvic hematoma. Of 10 cases (26%) which were identified to have ovarian hyperstimulation syndrome, eight (21%) had large amount of fluid collection in cul-de-sac and abdomen. Ultrasonographic identification of the intrauterine pregnancy and the ectopic chorion ring is effective for the early diagnosis of the heterotopic pregnancy.

  14. BIOMOD - preliminary findings

    International Nuclear Information System (INIS)

    Certain preliminary findings on the workings of the biosphere code BIOMOD are presented. These are intended as the basis for technical discussions relating to the development of BIOMOD1. Discussion is restricted to observations on the relationships between user-defined input and i) relative significance of different pathways for activity transfer to man, ii) total activity consumption by man, and iii) activity released to dose conversion factors to be used in SYVAC. (author)

  15. Heterotopic pregnancy: Sonographic findings

    Energy Technology Data Exchange (ETDEWEB)

    Kwon, Tae Hee [CHA General Hospital of Seoul, Pochon CHA University College of Medicine, Seoul (Korea, Republic of)

    1999-03-15

    To evaluate the sonographic findings of the heterotopic pregnancy which is increasing recently. Thirty-nine cases of heterotopic pregnancy after ovulation induction and IVF-ET (In Vitro Fertilization-Embryo Transfer) during the recent 3 years were analyzed. They were diagnosed by ultrasonography and proved surgically afterwards. Sonographic findings were analyzed focusing on gestational week of intrauterine pregnancy and location of ectopic pregnancy. In particular, adnexal mass was evaluated with regard to size and the characteristic findings such as ectopic gestational sac (echogenic ring). Also, overian cyst and fluid collection in cul-de-sac space were reviewed carefully. Heterotopic pregnancy was proved surgically by salpingectomy in 33 cases and by resection of cornus in six cases. Sonographic diagnosis using transvaginal ultrasound was made from five weeks to nine weeks two days (six weeks and four days in average) from last menstral period in all 39 cases. Ectopic pregnancy was identified in ampullary part in 29 cases, in the isthmic portion of tube in four cases and in the cornus of uterus in six cases. The intrauterine pregnancy was diagnosed by identifying the intrauterine gestational saccontaining a yolk sac in seven cases and the embryo with fetal heart beat in the remaining 32 cases. Adnexal masses of heterotopic pregnancy were less than 3 cm in diameter in 2 cases (57%), 3-4 cm in 11 cases (28%) and more than 4 cm in 6 cases (15%). A characteristic finding of ectopic mass was echogenic ring which was visible in 33 (84.6%) cases by transvaginal ultrasound. Six cases had pelvic hematosalpinx and two had pelvic hematoma. Of 10 cases (26%) which were identified to have ovarian hyperstimulation syndrome, eight (21%) had large amount of fluid collection in cul-de-sac and abdomen. Ultrasonographic identification of the intrauterine pregnancy and the ectopic chorion ring is effective for the early diagnosis of the heterotopic pregnancy.

  16. Cannabinoid findings in children hair - what do they really tell us? An assessment in the light of three different analytical methods with focus on interpretation of Δ9-tetrahydrocannabinolic acid A concentrations.

    Science.gov (United States)

    Moosmann, Bjoern; Roth, Nadine; Hastedt, Martin; Jacobsen-Bauer, Andrea; Pragst, Fritz; Auwärter, Volker

    2015-05-01

    Hair analysis for drugs and drugs of abuse is increasingly applied in child protection cases. To determine the potential risk to a child living in a household where drugs are consumed, not only can the hair of the parents be analyzed but also the hair of the child. In the case of hair analysis for cannabinoids, the differentiation between external contamination and systemic uptake is particularly difficult, since the drug is quite often handled extensively prior to consumption (e.g. when preparing a joint) and smoke causes a further risk for an external contamination. Δ9-tetrahydrocannabinolic acid A (THCA-A), the non-psychoactive biogenetic precursor of Δ9-tetrahydrocannabinol (THC), is a suitable marker for external contamination since it is not incorporated into the hair matrix through the bloodstream in relevant amounts. In the presented study, hair samples from 41 children, 4 teenagers, and 34 drug-consuming parents were analyzed for THCA-A, THC and cannabinol (CBN) applying methanolic extraction and a fully validated liquid chromatography-tandem mass spectrometry (LC-MS/MS) method (Method 1). For comparison, a part of the samples was also analyzed applying alkaline hydrolysis followed by liquid/liquid extraction and gas chromatography-mass spectrometry (GC-M)S (Method 2), or by headspace-solid phase microextraction-gas chromatography-mass spectrometry (HS-SPME-GC-MS) (Method 3). Furthermore, 458 seized marihuana samples and 180 seized hashish samples were analyzed for the same cannabinoids by gas-chromatography-flame ionization detector (GC-FID). In all but one of the hair samples, the concentration of THCA-A was higher than the concentration of THC and in 14 cases no THC could be detected despite the presence of THCA-A, suggesting that in almost all cases a significant external contamination had occurred. Within-family comparison showed a higher THCA-A/THC ratio in hair of children than of their consuming caregivers. Mean and median of this ratio of all hair samples (6.7 and 4.2) were between those of marihuana (11.0 and 8.3) and hashish (2.8 and 2.1) with a large variation in all samples. Comparison of the Methods 1 to 3 showed clearly that the choice of the analytical procedure has a strong influence on the quantitative results, mainly because of decarboxylation of THCA-A during hair hydrolysis by NaOH and other analytical steps, which lead to artifactually elevated THC concentrations. In conclusion, these findings suggest that the major part of the cannabinoids detected in the hair samples from children arose from an external contamination through 'passive' transfer by e.g. contaminated hands or surfaces and not from inhalation or deposition of side stream smoke. PMID:25069954

  17. MR findings of ulegyria

    International Nuclear Information System (INIS)

    Magnetic resonance (MR) findings of the brains diagnosed to have ulegyria were reviewed. The reviewed subjects comprised six epileptic children, ranged from 2 to 16 years of age. All patients had convulsion of tonic-clonic type of various severity and had histories of ischemic-hypoxic or hypoglycemic episode in the perinatal or postnatal period. T1-weighted images demonstrated the findings precisely reflecting the salient macroscopic features of ulegyria; localized atrophy of the brain with mushroom-shaped cortical gyri with narrow roots and relatively spared wider crowns. T2-weighted images showed the areas of hyperintensity in the subcortical and deep white matter subjacent to the atrophic cortex, suggestive of cicatrical gliosis as well as cystic degeneration. The atrophic gyri were seen in the anterior and/or posterior parasagittal arterial border zones bilaterally with minimal asymmetry. Although these findings were nearly pathognomonic to ulegyria, polymicrogyria could mimic it since both are characterized by abnormally diminutive cortical gyri seen in epileptic children. In polymicrogyria, however, affected gyri are uniformly diminutive and not mushroom-shaped, the cortex is rather thickened than atrophic, the underlying white matter shows no focal hyperintensity, subcortical cystic changes are not present, and affected cortex is not restricted to arterial border zones. Even in one of our cases with extensive ulegyria, it was easy to differentiate it from polymicrogyria since parasagittal regions were most severely affected. Although the previous reports on ulegyria have been exclusively based on postmortem pathological examinations or experimental models, its easy recognition on MRI would contribute to further understanding of its clinical significance and mechanisms. (author)

  18. Normal radiological findings

    International Nuclear Information System (INIS)

    This book is intended for learners in radiology, presenting a wealth of normal radiological findings together with a systematic guide for appraisal and interpretation, and for formulation of reports. The text examples and criteria given will help beginners in learning to 'read' a radiograph, and to verify their conclusions by means of checklists and standard reports. The case material covers numerous illustrations from the following sectors: Skeletal radiography, mammography, tomography, contrast radiography, organ examination by intravenous techniques, arthrography and angiography, and specialized radiography, (ECB) With 184 figs

  19. Finding things out

    CERN Document Server

    Arthur, Rhona; McCullough, Sheila

    2007-01-01

    Packed with useful information and adviceCovers modern and traditional routes to accessing informationHelps you evaluate the reliability of sourcesHandy checklists at the end of each section summarize the key points Finding Things Out offers solutions to anyone who has ever had trouble tracking down essential information. It describes the techniques that will lead to a successful outcome and covers the full range of resources available, including the World Wide Web, libraries and public record offices. It is a boon to students and researchers needing to trac

  20. Sialoblastoma: MRI findings

    Energy Technology Data Exchange (ETDEWEB)

    Yekeler, Ensar; Dursun, Memduh; Ucar, Adem; Genchellac, Hakan; Acunas, Gulden [Istanbul Faculty of Medicine, Department of Radiology, Istanbul (Turkey); Gun, Feryal; Kilincaslan, Huseyin [Istanbul Faculty of Medicine, Department of Paediatric Surgery, Istanbul (Turkey)

    2004-12-01

    Sialoblastoma is a rare, aggressive and potentially malignant salivary gland tumour diagnosed in the neonatal period. A total of 28 cases have been reported in the literature, but reports of the imaging findings are limited. We describe a neonate with a right parotid sialoblastoma. MRI showed a large facial mass, which was mostly hypointense to the brain on T1-weighted images and mildly hyperintense on T2-weighted images. There were foci of haemorrhage and necrosis. Heterogeneous and weak contrast enhancement was detected on contrast-enhanced images. The tumour invaded the maxilla and adjacent muscles. (orig.)

  1. Climate change: Recent findings

    International Nuclear Information System (INIS)

    In the late eighties several reports have been published on climate change and sea level rise. In the meantime insights may have changed due to the availability of better and more observations and/or more advanced climate models. The aim of this report is to present the most recent findings with respect to climate change, in particular of sea level rise, storm surges and river peak flows. These climate factors are important for the safety of low-lying areas with respect to coastal erosion and flooding. In the first chapters a short review is presented of a few of the eighties reports. Furthermore, the predictions by state of the art climate models at that time are given. The reports from the eighties should be considered as 'old' information, whereas the IPCC supplement and work, for example, by Wigley should be considered as new information. To assess the latest findings two experts in this field were interviewed: dr J. Oerlemans and dr C.J.E. Schuurmans, a climate expert from the Royal Netherlands Meteorological Institute (KNMI). Their views are presented together with results published in recent papers on the subject. On the basis of this assessment, the report presents current knowledge regarding predictions of climate change (including sea-level rise) over the next century, together with an assessment of the uncertainties associated with these predictions. 14 figs., 11 tabs., 24 refs

  2. Novel method of detecting movement of the interference fringes using one-dimensional PSD.

    Science.gov (United States)

    Wang, Qi; Xia, Ji; Liu, Xu; Zhao, Yong

    2015-01-01

    In this paper, a method of using a one-dimensional position-sensitive detector (PSD) by replacing charge-coupled device (CCD) to measure the movement of the interference fringes is presented first, and its feasibility is demonstrated through an experimental setup based on the principle of centroid detection. Firstly, the centroid position of the interference fringes in a fiber Mach-Zehnder (M-Z) interferometer is solved in theory, showing it has a higher resolution and sensitivity. According to the physical characteristics and principles of PSD, a simulation of the interference fringe's phase difference in fiber M-Z interferometers and PSD output is carried out. Comparing the simulation results with the relationship between phase differences and centroid positions in fiber M-Z interferometers, the conclusion that the output of interference fringes by PSD is still the centroid position is obtained. Based on massive measurements, the best resolution of the system is achieved with 5.15, 625 μm. Finally, the detection system is evaluated through setup error analysis and an ultra-narrow-band filter structure. The filter structure is configured with a one-dimensional photonic crystal containing positive and negative refraction material, which can eliminate background light in the PSD detection experiment. This detection system has a simple structure, good stability, high precision and easily performs remote measurements, which makes it potentially useful in material small deformation tests, refractivity measurements of optical media and optical wave front detection. PMID:26043175

  3. Novel Method of Detecting Movement of the Interference Fringes Using One-Dimensional PSD

    Directory of Open Access Journals (Sweden)

    Qi Wang

    2015-06-01

    Full Text Available In this paper, a method of using a one-dimensional position-sensitive detector (PSD by replacing charge-coupled device (CCD to measure the movement of the interference fringes is presented first, and its feasibility is demonstrated through an experimental setup based on the principle of centroid detection. Firstly, the centroid position of the interference fringes in a fiber Mach-Zehnder (M-Z interferometer is solved in theory, showing it has a higher resolution and sensitivity. According to the physical characteristics and principles of PSD, a simulation of the interference fringe’s phase difference in fiber M-Z interferometers and PSD output is carried out. Comparing the simulation results with the relationship between phase differences and centroid positions in fiber M-Z interferometers, the conclusion that the output of interference fringes by PSD is still the centroid position is obtained. Based on massive measurements, the best resolution of the system is achieved with 5.15, 625 μm. Finally, the detection system is evaluated through setup error analysis and an ultra-narrow-band filter structure. The filter structure is configured with a one-dimensional photonic crystal containing positive and negative refraction material, which can eliminate background light in the PSD detection experiment. This detection system has a simple structure, good stability, high precision and easily performs remote measurements, which makes it potentially useful in material small deformation tests, refractivity measurements of optical media and optical wave front detection.

  4. MR findings in mannosidosis

    International Nuclear Information System (INIS)

    MR findings are reported in three patients presenting mannosidosis. Among a family of 8 children, 4 presented typical clinical and biological abnormalities related to mannosidosis. Brain MR examinations including sagittal T1 and axial T2 sections were obtained in three patients of this family (one 25-year-old male, one 34-year-old female, and one 35-year-old female). MR scans demonstrate seven types of modifications: brachycephaly, thick calvaria, verticalization of the chiasmatic sulcus, poor pneumatization of the sphenoid body, partial empty sella turcica, cerebellar atrophy, and white matter signal modifications. High signal abnormalities involving the parieto-occipital white matter are identified on axial T2-weighted scans in the three patients and are probably related to demyelination and associated gliosis as described previously by several authors on specimens. (orig.)

  5. Ultrasonic range finding

    International Nuclear Information System (INIS)

    The patent concerns ultrasonic range finding equipment which can be employed in a nuclear reactor to monitor the spacing between structural components which are under stress. The invention is described with reference to the general layout of a pool-type liquid metal cooled fast breeder reactor. The equipment includes a generated reference signal, a portion of which is used to produce an ultrasonic beam which is directed towards a target. The ultrasonic beam is then reflected as an echo and received by a transducer. The pulse echo transit time and the phase displacement of the echo signal with respect to the reference signal, gives a measure of the range of the target with a high degree of precision. (U.K.)

  6. Radiologic findings of dwarfism

    International Nuclear Information System (INIS)

    The stature of human is very important factor in human-being, especially in childhood. The stature depends on various different conditions, such as familial factor, constitutional factor, chromosomal anomalies, skeletal disorders, or endocrinopathies. The early diagnosis of dwarfism is very important problem, because if appropriate treatment is delayed, the complication or sequales are more increased. The survey of familial history or patient's past history, detail check up of physical examination, radiological evaluation, and other laboratory examinations are essentially needed for the accurate diagnosis of dwarfism. Among the patients admitted to Yonsei University college of Medicine, Severance Hospital since 1963, with chief complaint of short stature or other associated diseases, an analysis of radiological findings were made for the 72 cases of chromosomal anomalies, skeletal dysplasia, and cretinism in which radiologic evaluation was available. The conclusions are as follows; 1. The cause of short stature are chromosomal anomalies (48 cases), skeletal dysplasia (14 cases) and cretinism (10 cases). 2. in chromosomal anomalies, 43 cases of mongolism and 5 cease of Turner's syndrome are noted. In mongolism, 18 cases among the 30 cases below 1 year old are distributed below the 10 percentile of height. On radiologic findings, 11 paired ribs (22/43), congenital heart disease (14/43), decreased iliac index (8/12), and associated anomalies or diseases, such as pneumonia (14 cases), C1-C2 dislocation (1 case), imperforated anus (1 case), Morgagni's hernia (1 case) and leukemia with sepsis (1 case). In Turner's syndrome, decreased bone density (5/5), positive metacarpal sign (2/5), positive carpal sign (1/5), change of knee joint (3/5), hypoplasia of (1/3), and increased carrying angle of elbows (1/3) are noted

  7. Ultrasonographic findings of retinoblastoma

    International Nuclear Information System (INIS)

    Retinoblastoma is the most common intraocular tumor in infants and young children which has relatively favorable prognosis with early diagnosis and adequate treatment, however, it can be lethal if the treatment is delayed or inadequate. Clinically, early diagnosis is often difficult because of minimal subjective and objective signs and symptoms, and the patients are usually too young to complain visual disturbance. When ophthalmoscopicexamination is impossible due to presence of opaue media in front of tumor mass as associated inflammatory reaction, hemorrhage, corneal opacity, retinal detachment, etc, ultrasonography is necessary for diagnosis of retinoblastoma. Authors analyzed ultrasonographic al findings with pathological correlation on 10 cases of confirmed retinoblastoma during the period of March 1981 to September1982 at the Seoul National University Hospital. In all cases, ultrasonography demonstrates intraocular masses and all of which are cystic type.Reflectivity of masses are higher than retroorbital fat tissue in 8 cases, and 7 cases show irregular internal echogenic texture. There is no correlation between reflexivity and internal echogenic texture with microscopic findings as rosette, pseudo rosette and micro cysts. Calcifications are demonstrated by ultrasonography as strong reflectiveness with posterior sonic shadowing in 9 cases and 9 of 10 cases are well correlated with calcifications in pathologic specimens. Anechoic cystic areas are shown in 9 cases, and 6 of 10 cases are well correlated with necrosis in pathologic specimen. In all cases, there is no attenuation of sound within tumor masses, and no demonstrable choroidal excavation. Associated retinal detachment is hardly identifiable in irregular contour and internal texture of cystic tumor masses

  8. Imaging Findings of Gastric Diverticula

    OpenAIRE

    Dominik Schramm; Andreas Gunter Bach; Alexander Zipprich; Alexey Surov

    2014-01-01

    Introduction. Gastric diverticula (GD) are very rare. Computer tomographic findings in GD have been reported only as case reports previously. The aim of this study was to estimate the prevalence of GD on computed tomography (CT) and to analyze their radiological appearances. Materials and Methods. From 2006 to 2013, a total of 14,428 patients were examined by abdominal/thoracic CT at our institution. GD were diagnosed in 18 (0.12%) patients (13 women and 5 men, median age, 64 years). In 9 pat...

  9. Brain venous pathologies: MRI findings

    International Nuclear Information System (INIS)

    Purpose: To describe MRI findings of the different brain venous pathologies. Material and Methods: Between January 2002 and March 2004, 18 patients were studied 10 males and 8 females between 6 and 63 years old; with different brain venous pathologies. In all cases brain MRI were performed including morphological sequences with and without gadolinium injection and angiographic venous sequences. Results: 10 venous occlusions were found, 6 venous angiomas, and 2 presented varices secondary to arteriovenous dural fistula. Conclusion: Brain venous pathologies can appear in many different clinical contexts, with different prognosis and treatment. In all the cases brain MRI was the best imaging study to disclose typical morphologic abnormalities. (author)

  10. Finding Communities of Related Genes

    CERN Document Server

    Wilkinson, D; Wilkinson, Dennis; Huberman, Bernardo A.

    2002-01-01

    We present an automated method of identifying communities of functionally related genes from the biomedical literature. These communities encapsulate human gene and protein interactions and identify groups of genes that are complementary in their function. We use graphs to represent the network of gene cooccurrences in articles mentioning particular keywords, and find that these graphs consist of one giant connected component and many small ones. In addition, the vertex degree distribution of the graphs follows a power law, whose exponent we determine. We then use an algorithm based on betweenness centrality to identify community structures within the giant component. The different structures are then aggregated into a final list of communities, whose members are weighted according to how strongly they belong to them. Our method is efficient enough to be applicable to the entire Medline database, and yet the information it extracts is significantly detailed, applicable to a particular problem, and interesting...

  11. Findings of autopsy imaging

    International Nuclear Information System (INIS)

    Described is the outline of autopsy imaging (Ai) by CT, MRI and ultrasonography (US) as the reading of the postmortem images is becoming important for radiologist on site. The present major Ai modality is CT, where the cause of death can be identified in most cases of injuries like that by traffic accident, and of intracranial hemorrhagic lesions. It is difficult for CT alone to determine the cause due to acute heart failure, for which Ai by enhanced CT (2-min heart massage during the intravenous infusion of a contrast agent) has been introduced. CT findings in Ai are varied according to the death cause, anabiotic treatment conducted and postmortem changes. The second item includes the gastrointestinal tract dilation, rib fracture, pneumo- or hemo-thorax, bruise or rupture, and intravascular gas, and the third, the blood hypostasis, which emphasizing the shadow at the gravity-loaded portions in Ai CT. MRI signals vary dependently on the temperature and the inversion time should be shortened to suppress the cerebrospinal signal at Ai of the cold body like that stored in a refrigerator. US can detect clear, macroscopic morphological changes and the portable machine has been in practice at autopsy onsite. As sound speed depends on the temperature in water, Ai US images are obscure relative to living body due to the low temperature. Authors think the problem to identify the cause of death will be mostly solved in Japan when radiological technologists more actively participate in Ai. (K.T.)

  12. Pulmonary sarcoidosis: CT findings

    International Nuclear Information System (INIS)

    Pulmonary sarcoidosis is a systemic disease of unknown cause characterized by the presence of noncaseating granulomas: the associated morbidity and mortality is usually due to pulmonary involvement. To determine the radiological signs of pulmonary sarcoidosis according to high-resolution computed tomography (HRCT) and compare our results with those reported elsewhere. We have made no attempt to establish a correlation between the plain radiographic image and that resulting from HRCT or between the radiologic image and the results of the pathologic study. We employed HRCT to study a series of 21 patients (15 women and 6 men) confirmed by biopsy as having sarcoidosis. The signs assessed include: nodules, ground glass, septal lines, non septal lines, honey combing, architectural changes, traction bronchiectasis and lymphadenopathy. The most common finding, observed in 20 of the 21 cases (95%), were nodules. Their distribution was mainly peribronchovascular or peripherally centrilobular and subpleural. The remaining signs were much more inconsistent and were associated with maximal nodular involvement. The presence of nodular images arranged as described above is typical of sarcoidosis and when observed in the proper clinical context is practically diagnostic of this lesion. (Author) 10 refs

  13. Verified scientific findings

    International Nuclear Information System (INIS)

    In this essay, the author attempts to enlighten the reader as to the meaning of the term ''verified scientific findings'' in section 13, sub-section 1, sentence 2 of the new Chemicals Control Law. The examples given here are the generally accepted regulations in regards to technology (that is sections 7a and 18b of the WHG (law on water economy), section 3, sub-section 1 of the machine- and engine protection laws) and to the status of technology (section 3, sub-section 6 of the BImSchG (Fed. law on prevention of air-borne pollution)), and to the status of science (section 5, sub-section 2 of the AMG (drug legislation). The ''status of science and technology'' as defined in sections 4 ff of the Atomic Energy Law (AtomG) and in sections 3, 4, 12, 2) of the First Radiation Protection Ordinance (1.StrlSch. VO), is also being discussed. The author defines the in his opinion ''dynamic term'' as the generally recognized result of scientific research, and the respective possibilities of practical utilization of technology. (orig.)

  14. Radiographic findings in immunodeficiency

    International Nuclear Information System (INIS)

    This paper reviews the chest radiographs and high-resolution CT (HRCT) scans in patients with immunodeficiency disorders and define the role of HRCT. Thirty-three cases were retrospectively graded according to the consensus of two radiologists. Patients with HIV seropositivity and asthma were excluded. HRCT was performed in 12 cases with standard techniques. Diagnoses included common variable hypogammaglobulinemia (n = 19), X-linked agammaglobulinemia (n = 4), chronic mucocutaneous candidiasis (n = 4), and selective immunoglobulin g deficiencies (n = 2). Chest radiographs showed bronchiectasis in 11 of 33 cases with a predominant lower lobe distribution (82%). Nodules were present in six cases and mucus plugs in four cases. HRCT showed bronchiectasis in nine of 12 cases; in five of these nine cases, bronchiectasis was not apparent on chest radiographs. Other HRCT findings included segmental air trapping (four of 12), mucus plugs (three of 12), hazy consolidation (four of 12), nodules (five of 12), and bronchiolectasis (two of 12). Therapy was altered in seven of 12 cases in which HRCT was performed. Most pertinent to clinical management were the presence of a thymoma (n = 1) and severe focal of diffuse bronchiectasis

  15. Ultrasonographic findings of acute appendicitis

    International Nuclear Information System (INIS)

    For the evaluation of acute appendicitis, many diagnostic methods, such as physical examination, laboratory findings, plain abdomen and barium enema have been widely used. But the overall accuracy was ranged from 50% to 84% and negative appendectomy rate was reported between 5% and 35%. In these days, high resolution ultrasonography is well known to be a good imaging modality in evaluation of acute appendicitis and its complications. Using high resolution ultrasonography, 138 patients with right lower quadrant abdominal pain were examined for 16 months. The results were compared to post-operative findings and clinical follow up study. The results were as follows: 1. The sex distribution of cases were 58 males and 80 females, and most common in the third decade (33.3%). 2. The positive ultrasonographic findings were in 69 cases (50%), those were simple appendicitis without complication in 46 cases (66.7%), acute appendicitis with periappendicitis in 9 cases (13.0%), acute appendicitis with abscess in 6 cases (8.7%), acute appendicitis with appendicolith in 4 cases (5.8%) and perforated appendicitis in 4 cases (16%). 3. The ultrasonographic findings of normal appendix were in 69 cases (50%), those were nonvisualization of appendix in 62 cases (91.3%) and visualization of normal appendix with single thin echogenic wall in 6 cases (8.7%). 4. In the 50 cases of control group, the visualization of normal appendix on ultrasonography were in 8 cases (16%). 5. The overall accuracy was 95.7% with 97.1% of sensitivity and 94.4% of specificity

  16. Pathological findings in SIDS.

    Science.gov (United States)

    Berry, P J

    1992-11-01

    The original 1969 definition of SIDS as "unexpected by history" and "unexplained after thorough postmortem examination" is under review in the light of two decades of experience. Suggested modifications include restricting the age to less than 1 year, stipulating that the necropsy includes appropriate histology and laboratory tests, and requiring a review of the clinical history and examination of the death scene. The use of a protocol is recommended both by professional and parent groups. Although the diagnosis of SIDS is to some extent one of exclusion, there are several typical findings which are of value in diagnosis and suggest new avenues for research. External examination is important to exclude trauma and signs of suffocation. A recent study has confirmed that petechiae on the face are rare in SIDS and if found raise the question of deliberate or accidental suffocation. Frothy fluid escaping from the nose and mouth is seen in about half of infants who die from SIDS. Postmortem hypostatic staining as an indicator of position has assumed increased importance since prone sleeping has been shown to be a major risk factor for SIDS. Evidence of sweat in clothing suggests overwrapping. Internal examination shows subserosal petechial haemorrhages in the thymus in most cases. These may be related to age and are commoner in babies dying of SIDS than in controls. Relative sparing of the cervical extension of the thymus is strong evidence for negative intrathoracic pressure, perhaps due to upper or lower airway obstruction. Other typical findings are liquid heart blood, prominent lymph nodes, and an empty bladder (which frustrates some biochemical tests in about half of cases). The lungs are usually well inflated, arguing against surfactant deficiency as a significant cause of SIDS. Microscopic evidence of pulmonary oedema and congestion is found in infant deaths for many reasons and is not discriminatory for SIDS. Minor inflammation and infection of the respiratory tract is common in SIDS and may be important by contributing to overheating, apnoea, or sensitisation to bacterial toxins. Mild fatty change in the liver is very common in infant deaths. Panlobular microvesicular fatty change is rare and may require special stains for its recognition. It indicates the necessity of searching for inherited biochemical disorders. Although these are rare in true SIDS, they are an important cause of unexpected death in infancy. Of Naeye's "tissue markers of hypoxia'', extramedullary haemopoiesis in the liver and brainstem gliosis have been confirmed. Persistence of fetal haemoglobin and raised hypoxanthine values in vitreous humour are further pointers to periods of premortem hypoxia. Painstaking neuropathology has shown delayed myelination and maturation of dendritic spines. Changes in the brain may explain the link between antenatal factors such as smoking and SIDS. A second cot death in a family requires expert examination. Minor injuries or unexplained apnoeic spells may be important retrospective clues to non-accidental injury. Investigations mus exclude inherited disorders before the death is ascribed to SIDS. Parents demand that the pathologist takes care of their baby before, during, and after the necropsy, carries out the procedure to a high standard, checks reconstruction of the body, facilitates access, and is responsible for communicating the results of the examination. The "SIDS postmortem" presents both a practical and an intellectual challenge. PMID:1474151

  17. Tomographic and pathological findings in pulmonary sarcoidosis

    Energy Technology Data Exchange (ETDEWEB)

    Melo, Alessandro Severo Alves de; Marchiori, Edson [Universidade Federal Fluminense (UFF), Niteroi, RJ (Brazil). Dept. of Radiology; Capone, Domenico [Universidade do Estado do Rio de Janeiro (UERJ), Rio de Janeiro, RJ (Brazil). Dept. of Pneumology

    2011-07-15

    Objective: To analyze radiological findings observed at high-resolution computed tomography in patients with sarcoidosis, and establishing their correlation with pathological findings. Materials and Methods: High-resolution computed tomography findings in ten patients with sarcoidosis were reviewed and correlated with findings in specimens obtained by surgical biopsy or at necropsy of four of such patients. Results: The most frequently observed finding was presence of nodules with perilymphatic distribution, predominating along bronchovascular sheaths and pleural surface, with subpleural nodules and nodular scissurae. Other less frequent findings were ground-glass attenuation and interlobular septa thickening. Conclusion: In general, all the mentioned findings demonstrated anatomopathological correlation with development of granulomas in these regions. (author)

  18. Neutropenic enterocolitis: CT findings

    International Nuclear Information System (INIS)

    Purpose: to evaluate the role of computed tomography (CT) in the diagnosis of neutropenic enterocolitis (NEC). Material and Methods: we studied 7 immunocompromised patients (6 male, 1 female, age range: 30-75 years, mean: 57.7 years), due to treatment of malignant tumors. All these had clinical symptoms and signs consistent with neutropenic enterocolitis. Results: CT showed thickening of the bowel wall (n=7), changes in fat density (n=5) and free fluid in abdominal cavity (n=3). One patient received surgical treatment due to a toxic megacolon. Four patients died due to multi organic failure. Three patients showed a favorable clinical evolution. Conclusions: CT contributes significantly to the diagnosis of NEC in immunocompromised patients with clinical suspicion of this pathology. (author)

  19. Hippocampal malrotation: MRI findings

    International Nuclear Information System (INIS)

    Purpose: To demonstrate the common features of hippocampus malrotation in patients with epilepsy by volumetric and high-resolution MRI. Material and methods: MRI study was performed in 5 patients (2 females and 3 males) ages ranged between 6-41 years (average: 25 years), all of them with epilepsy diagnosis. MRI was performed with a 1.5 T (GE Signa). The epilepsy protocol include sagittal T1, axial T1 and T2, coronal FLAIR, coronal T2 (high-resolution) and volumetric 3D SPGR IR 1.5 mm thick sequences. Results: The common features found in all patients were: a) Incomplete inversion and round configuration of the hippocampus; b) Unilateral affectation; c) Variable affectation of the hippocampus; d) Normal signal intensity; e) Modification of the inner structure of the hippocampus; f) Abnormal angularity of the collateral sulcus; g) Abnormal position and size of the fornix; h) Normal size of the temporal lobe; and i) Enlargement of the temporal horn with particular configuration. Conclusion: Hippocampus malrotation is a malformation that should be included in the differential diagnosis of the epilepsy patients. MRI provides accurate information for the diagnosis. (author)

  20. The color doppler ultrasonography findings of leptospirosis

    International Nuclear Information System (INIS)

    Objective: To study the color ultrasonography findings of leptospirosis. Methods: The color ultrasonography findings of heart, liver, spleen, kidney, lymph node and gastrocnemius in 51 cases of leptospirosis were studied retrospectively. Results: Changes of the color ultrasonography findings were showed in all cases. The changes of liver, kidney, lymph node and gastrocnemius were conspicuous, and the positive rates were 62%, 47%, 88% and 90%. Conclusion: Changes of the color ultrasonography findings of heart, liver, spleen, kidney, lymph node and gastrocnemius can be found in leptospirosis cases, without specificity. (authors)

  1. Sonographic Findings of Human Fascioliasis

    Directory of Open Access Journals (Sweden)

    F. Mansour Ghanaei

    2006-08-01

    Full Text Available Background/Objective: Ultrasonography is an imaging modality which is easy to use and less expensive than other imaging methods. It is becoming more widely available in regions of the world where Fasciola hepatica infestation is prevalent. In this report, we described the sonographic findings of hepatic lesions in patients with fascioliasis. Patients and Methods: In this cross-sectional study, 248 patients with confirmed hepatic fascioliasis from Guilan province who were referred by internists or infectious disease specialists to private sonographic offices were studied. Abdominal sonography was performed in supine and left decubitus positions using an Aloka 288 scanner and a 3.5 MHz transducer. Results: Out of 176 hepatobiliary involvement, the right lobe of liver and the periportal area with echoic or hypoechoic lesions, had the most involvement (45.2%. There were lesions in the gallbladder of 34 (13.7% and biliary tracts of 17 (7% patients. There was coincident in-volvement of both liver and biliary tracts in 13 (5.2% patients. Conclusion: Sonography is a useful method to confirm hepatobiliary lesions in human fascio-liasis and can facilitate the diagnosis of this condition, particularly in areas where it is endemic.

  2. Presentation of findings

    International Nuclear Information System (INIS)

    The conference served an important purpose in bringing together and consolidating information on the termination of nuclear practices from around the world, and the Proceedings will therefore represent a very valuable overview of the current situation. I should add, however, that the information presented at the conference was concentrated on the decommissioning of large nuclear facilities. A concerted international effort should be made to obtain a realistic picture of the scope of the decommissioning task to be expected from the many other practices using radioactive material, for example in medical, industrial and research applications. In this regard, one notes that the IAEA is currently compiling information on the magnitude of this problem, and urge it to continue with this work. This should provide a solid basis for an international discussion of actions to begin solving the problem. A great deal of practical decommissioning experience that has been accumulated was presented at the conference.The international community should consider ways to make this information more widely available. The IAEA could contribute to this by means of a Web-based chat room dedicated to decommissioning. One conclusion from the discussion was that the IAEA should ensure that its safety standards on decommissioning are reviewed, improved and updated, and provide more detailed guidance on practical issues. Turning to the main findings from Sessions 2.A - 2.E, six major topics emerged: the importance of early and thorough planning; social issues; funding; waste management issues; long term retention of knowledge; and the removal of regulatory controls. With regard to the issue of early planning for decommissioning, emphasis was placed during the conference on the importance of planning decommissioning thoroughly. Planning should start as early as possible, ideally at the design stage of a facility, as required by the Joint Convention on the Safety of Spent Fuel Management and on the Safety of Radioactive Waste Management. The overall decommissioning strategy to be adopted should be identified as early as possible in the planning process. The presentations and discussions at this conference indicated a distinct shift towards immediate dismantling as a preferred strategy. Turning to social issues, the participation of the public, including community leaders, work forces and interest groups, in the decision making processes should be initiated as early as possible and should continue throughout the process. The aim is to minimize the negative social and economic effects of decommissioning. In the discussion on waste management issues, it was noted that there was progress on the provision of national repositories for radioactive waste would be of great benefit to decommissioning. The long term retention of knowledge is of great importance in two respects: people and records. Funding is clearly vital to decommissioning. Provision needs to be made to ensure that sufficient funds will be available, with a high degree of confidence, when they are needed. An appropriate mechanism should be in place before a new facility is licensed to operate. With regard to the removal of regulatory controls, it was noted that the recycling or reuse of materials from decommissioning can greatly reduce the amount of waste that needs to be disposed of in a repository.This can preserve resources and repository capacity. Criteria for the international trade in such materials are needed, and therefore should be internationally agreed. A great deal of work has been done aimed at establishing criteria for the removal of materials from regulatory control.Work aimed at reaching international consensus on an acceptable methodology, including codes and scenarios, for establishing clearance levels should continue. Questions remain as to whether the criteria for the release of sites should be the same as those for materials, whether natural and artificial radionuclides can be subject to the same criteria, and whether there is a market for materials released from a nuclear facility, even in the case when they have been declared to be 'non-radioactive'. The international community should make concerted efforts to resolve these issues

  3. Ultrasonographic findings of ovarian tumors

    International Nuclear Information System (INIS)

    The ultrasound is easily available and noninvasive diagnostic method without radiation hazard. We can approach to differential diagnosis of ovarian tumors by gray scale ultrasound which can display the detailed structure of soft tissue. In department of radiology, Korea Veterans Hospital, 27 cases of histologically confirmed ovarian tumors collected from March 1984 to February 1986 were analyzed. The results were as follows: 1. The age distribution was from 13 to 72 years. 2. The histologic diagnosis of ovarian tumors (27 cases) are as follows; teratoma (14), mucinous cystadenoma (8), mucinous cystadenocarcinoma (1), serous cystadenoma (2), Krukenburg tumor (1) and malignant thecoma (1). 3. The long diameter of ovarian tumors ranges from 4 cm to 28 cm. In these, mucinous cystadenoma is the largest and their size are as follows; less than 10 cm; 25%, 11-15 cm; 12%, 16-20 cm; 25% and more than 20 cm; 38%. 4. The ultrasonographic findings of teratoma (14) were mainly cystic (8) or echogenic (6). There were echogenic solid components showing distal acoustic shadowing or fat-fluid level within cystic masses. Echogenecity of solid masses was heterogenous. 5. The ultrasonographic findings of mucinous cystadenoma and cystadenocarcinoma (9) were unilocular cystic (3) or multilocular cystic (6). There were variable amount of echogenic component within cystic masses. 6. Those of serous cystadenoma (2) were unilocular cystic (1) or multilocular cystic (1). 7. Krukenburg tumor (1) and Malignant thecoma (1) were heterogenously echogenic.

  4. Arthroscopic findings after shoulder dislocation

    Directory of Open Access Journals (Sweden)

    Medenica Ivica

    2009-01-01

    Full Text Available Background/Aim. Recurrent instability of the shoulder joint is frequently difficult to differentiate from diseased or injured rotator cuff or tendon of the forearm flexor (m. biceps brachii. Shoulder joint arthroscopy has been only recently introduced into instable shoulder joint lesion examination. The aim of this study was to present and analyze an arthroscopic finding on instable shoulder joint in order to determine causes and mechanisms of instability, as well as principles of surgical treatment. Methods. Arthroscopy of the shoulder joint was performed in 158 patients with at least one documented shoulder joint dislocation. These patients were divided into two groups. The group I included the patients with one to three dislocations, while the group II those with more than three dislocations. Preoperative diagnosis was based on anamnestic data and clinical examination using specific tests, and on the diagnosis of shoulder joint using radiography or computed tomography. Results. Out of the total number of the patients 138 (87.34% had injury of the anterior patellar brim, 119 (75.32% had failure of the anterior capsule, 126 (79.75% had compressive cartilage injury of the posterior part of the head of the upper arm bone (Hill-Sachs lesion, 102 (64.56% had insufficiency of glenohumeral tendon, 11 (6.96 had complete cut of the rotator cuff, 23 (14.56% had injury of the posterior patellar brim, 12 (7.59% had injury of the upper anterior-posterior patellar brim (SLAP. Conclusion. According to the obtained results it could be concluded that there is no a unique injury that leads to shoulder joint instability. It is necessary to point out to the significance of anamnesis and clinical examination in making diagnosis. Arthroscopic diagnostics is indicated in clinically unreliable findings as an additional method for determining operative treatment.

  5. MR findings of polymyositis / dermatomyositis

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Hak Soo; Joo, Kyung Bin; Moon, Won Jin; Lee, Tae Hee; Park, Ki Ho; Park, Dong Woo; Hahm, Chang Kok [Hanyang Univ. College of Medicine, Seoul (Korea, Republic of)

    1998-07-01

    The purpose of this study was to evaluate the MR findings and useful sequences in Polymyositis/ Dermatomyositis, and to correlate MR findings with disease activity. Materials and Methods: The study included nine clinically proven cases of Polymyositis/Dermatomyositis, eight involving the thigh and one, the shoulder (2 cases, 1 follow-up). The contrast between affected and normal muscles and difference in signal intensity ratio in the muscle groups were retrospectively evaluated on Gd-enhanced T1WI and T2WI. We also evaluated the magnitude of involvement of muscle groups, fatty replacement of muscle and change of subcutaneous fat layer, and correlated signal intensity ratio with serum level of muscle enzymes. Differences in signal intensity ratio and the frequency of chemical shift artifact were evaluated on T2WI as active and inactive groups classified according to clinical findings, and the chemical shift artifact was correlated with the finding of Gd-enhanced T1WI. Except in the case of one shoulder, statistical analysis was assessed by the Anova test and-test. Results: On Gd-enhanced T1WI and T2WI contrast was 0.54 and 0.82, respectively and p value was 0.02. With regard to difference in signal intensity ratios of muscle groups, as seen on Gd-enhanced T1WI and T2WI, p valves were 0.07 and < 0.01, respectively. Muscle involvement was thus clearly visualized on T2WI. The order of frequency of involved muscle groups was vastus muscles, gluteus maximus, sartorius muscles, adductor muscles, gracilis muscle, and hamstring muscles. Fatty replacement and subcutaneous fatty change were visualized in five cases and one, respectively. The correlation coefficient between the signal intensity seen on T2WI and muscle enzymes was 0.59 (CPK) and 0.52 (LDH). The chemical-shift artifact was detected in both clinical groups (four active two inactive) and corresponded to one case of muscle involvement and five of perimuscular edema, as seen on Gd-enhanced T1WI. Conclusion: T2WI is useful for the evaluation of muscle involvement and correlated closely with disease activity; signal intensity ratio could not be substituted for the serum level of muscle enzymes. The group of thigh muscles most affected was the vastus muscles, while the hamstring muscles were least affected. The chemical-shift artifact corresponded mainly to perimuscular edema and did not correlate with disease activity.

  6. MR findings of polymyositis / dermatomyositis

    International Nuclear Information System (INIS)

    The purpose of this study was to evaluate the MR findings and useful sequences in Polymyositis/ Dermatomyositis, and to correlate MR findings with disease activity. Materials and Methods: The study included nine clinically proven cases of Polymyositis/Dermatomyositis, eight involving the thigh and one, the shoulder (2 cases, 1 follow-up). The contrast between affected and normal muscles and difference in signal intensity ratio in the muscle groups were retrospectively evaluated on Gd-enhanced T1WI and T2WI. We also evaluated the magnitude of involvement of muscle groups, fatty replacement of muscle and change of subcutaneous fat layer, and correlated signal intensity ratio with serum level of muscle enzymes. Differences in signal intensity ratio and the frequency of chemical shift artifact were evaluated on T2WI as active and inactive groups classified according to clinical findings, and the chemical shift artifact was correlated with the finding of Gd-enhanced T1WI. Except in the case of one shoulder, statistical analysis was assessed by the Anova test and-test. Results: On Gd-enhanced T1WI and T2WI contrast was 0.54 and 0.82, respectively and p value was 0.02. With regard to difference in signal intensity ratios of muscle groups, as seen on Gd-enhanced T1WI and T2WI, p valves were 0.07 and < 0.01, respectively. Muscle involvement was thus clearly visualized on T2WI. The order of frequency of involved muscle groups was vastus muscles, gluteus maximus, sartorius muscles, adductor muscles, gracilis muscle, and hamstring muscles. Fatty replacement and subcutaneous fatty change were visualized in five cases and one, respectively. The correlation coefficient between the signal intensity seen on T2WI and muscle enzymes was 0.59 (CPK) and 0.52 (LDH). The chemical-shift artifact was detected in both clinical groups (four active two inactive) and corresponded to one case of muscle involvement and five of perimuscular edema, as seen on Gd-enhanced T1WI. Conclusion: T2WI is useful for the evaluation of muscle involvement and correlated closely with disease activity; signal intensity ratio could not be substituted for the serum level of muscle enzymes. The group of thigh muscles most affected was the vastus muscles, while the hamstring muscles were least affected. The chemical-shift artifact corresponded mainly to perimuscular edema and did not correlate with disease activity

  7. A new method for designing floor slabs on grade due to the difficulty of applying simplified design methods, amongst them being the Portland Cement Association (PCA) and Wire Reinforcement Institute (WRI) methods

    OpenAIRE

    Hugo Ernesto Camero Sanabrial

    2010-01-01

    This article presents a methodology for designing slabs on grade for industrial floors where there is an eccentricity between the slab centroid and the gravity centre loads of the loaded axle of forklift trucks travelling over the floor. An example was used for analysing how Portland Cement Association (PCA) and the Wire Reinforcement Institute (WRI) methods are inadequate for designing floors sublected to this condition. The new proposal for designing slabs on grade for industrial floors h...

  8. Learning as way-finding

    DEFF Research Database (Denmark)

    Dau, Susanne

    This paper is based on case study findings from studying undergraduate students’ perceptions of their navigation in a blended learning environment where different learning spaces are offered. In this paper learning is regarded as a multi-level and multi complex concept. In this regard the concept of learning used in this paper is inspired by the latest work of the Danish professor Illeris and the interwoven concept of knowledge development as revealed in the SECI-model generated by the Japanese professors Nonaka and Takeuchi. The empirical investigation, which is the basis of the presented assumptions, is based on the findings from research of the implementation of blended learning in two undergraduate programmes at University College North in Denmark. The data collection methods is based on eighteen focus-group interview collected in a period of the first two years of students enrolment in radiography and teachers education. Furthermore, a survey was conducted after three month of students’ enrolment and some few observations-studies in teachers’ education. The empirical data are interpreted in a narrative form through the use of prefiguration, configuration and refiguration and presented as themes around plots in a narrative form. The findings reveal that students’ use of different learning spaces are challenged by inhabited and embodied practices as well as disruptions. It is argued that learning must be viewed in the light of the new technological possibilities and challenges in spaces. There seem to be “blurred ecotones” between studying, leisure, sociality, identity-seeking and daily life which demands for an extension of the concept of learning. It is stressed that learning are conditioned by contextual orientations-processes in peripersonal spaces. Spaces of learning seem to guide how learning can be afforded and which kinds of learning. It is revealed that learning can be both constructed socially and individually but is constituted by the contextual orientation of the learner/s. Based on these findings it is suggested that learning (both formal and informal) can be conceptualized as way-finding both embodied, emotionally and/or cognitive. Way-finding, is argued, to be a concept for learning processes, knowledge development and identity-shaping where humans learn through motions, feeling and thinking in a world in motion and through combined actions of human and non-human agencies. Furthermore it is argued that cognitive learning-processes are intertwined with embodied learning, and that there are different levels of reflection, cognition and learning driven by outer and inner motifs, meaning, experiences, habits and outer conditions. In the discussion I suggest that learning in this century must take conditions of attention overload into account as an everyday condition which is more than ever actualized by the extended disruptions both by the information technology and other spaces. Based on the discussion areas for future research are suggested.

  9. The multidimensional evaluation and treatment of anxiety in children and adolescents: rationale, design, methods and preliminary findings Avaliação multidimensional e tratamento da ansiedade em crianças e adolescentes: marco teórico, desenho, métodos e resultados preliminares

    OpenAIRE

    Giovanni Abrahão Salum; Luciano Rassier Isolan; Vera Lúcia Bosa; Andrea Goya Tocchetto; Stefania Pigatto Teche; Ilaine Schuch; Jandira Rahmeier Costa; Marianna de Abreu Costa; Rafaela Behs Jarros; Maria Augusta Mansur; Daniela Knijnik; Estácio Amaro Silva; Christian Kieling; Maria Helena Oliveira; Elza Medeiros

    2011-01-01

    OBJECTIVE: This study aims to describe the design, methods and sample characteristics of the Multidimensional Evaluation and Treatment of Anxiety in Children and Adolescents - the PROTAIA Project. METHOD: Students between 10 and 17 years old from all six schools belonging to the catchment area of the Primary Care Unit of Hospital de Clínicas de Porto Alegre were included in the project. It comprises five phases: (1) a community screening phase; (2) a psychiatric diagnostic phase; (3) a multid...

  10. Findings

    Science.gov (United States)

    ... Response Chemistry and Biochemistry Enzymes, Molecular Probes, Metabolic Engineering, Glycobiology, Synthesis, Natural Products, Chemical Reactions Computers in Biology Bioinformatics, Modeling, Systems Biology, Data Visualization ...

  11. Improve the Robustness of Range-Free Localization Methods on Wireless Sensor Networks using Recursive Position Estimation Algorithms

    OpenAIRE

    Gamantyo Hendrantoro; Wirawan; Kristalina Prima

    2011-01-01

    The position of a sensor node at wireless sensor networks determines the received data sensing accuracy. By the knowledge of sensor positioning, the location of target sensed can be estimated. Localization techniques used to find out the position of sensor node by considering the distance of this sensor from the vicinity reference nodes. Centroid Algorithm is a robust, simple and low cost localization technique without dependence on hardware requirement. We propose Recursive Position Estimat...

  12. CT findings of Wilson's disease

    International Nuclear Information System (INIS)

    Thirteen cases of Wilson's disease were examined by computerized tomography. Two of them were latent cases. The other 11 were typical cases with a Kayser-Fleisher ring and neurological signs, and in which the ceruloplasmin level in serum was low. The caudate heads were measured by Barr's method using two ratios, FH/CC and CC/OT. The CT findings were as follows: (1) caudate head atrophy (10 cases), (2) cerebral atrophy and/or ventricular dilatation (7 cases), (3) symmetrical low density of thalamus (3 cases), (4) symmetrical low density of pallidum (2 cases), (5) low density of midbrain (2 cases), (6) symmetrical low density of putamen (1 case), (7) pons atrophy (1 case), (8) cerebellar atrophy (1 case), (9) low density of r-temporal area (1 case). All of them except for the two latent cases showed some abnormal findings on CT. Only one symptomatic case showed no caudate atrophy one year after the onset, though two other cases already showed marked atrophy after only 10 months. It was stressed that the low-density lesions in the thalamic area were found with a high frequency. There was no correlation between the duration of illness and the degree of caudate atrophy among the patients with Wilson's disease as compared with those with Huntington's chorea. As in a previous study of pneumoencephalography, we failed also to distinguish the two diseases by measuring the ratios on CT films. It may be valuable to study the progression of the CNS lesions of Wilson's disease by using CT repeatedly. (author)

  13. Chronic eosinophilic pneumonia: CT findings

    International Nuclear Information System (INIS)

    Objective: To assess the usefulness of computerized tomography (CT) in the diagnosis of chronic eosinophilic pneumonia. Material and Methods: A double helical CT was performed in 6 patients referred to our center because of a chest X-ray with pulmonary infiltrates. Clinical presentation was cough, fever and eosinophilia in peripheral blood. Patients' age ranged from 25 to 55 years; 4 were women and 2 were men, one of the latter had a history of bronchial asthma. All patients received treatment with corticosteroids, with remission of the clinical and radiological parameters. Three patients underwent a control CT. Results: Findings consisted in focal parenchymal alterations, with areas of pulmonary consolidation and areas of 'ground glass' appearance; both patterns coexisted in certain areas. In 3 cases the lesions extended from the apices to the pulmonary bases, with predominance of the upper and middle fields. In 1 patient, there was frank predominance in the left hemi thorax. In another patient, who had a history of asthma, there were signs of pulmonary hyperinflation, with diffuse thickening of the bronchial walls, added to the previously mentioned findings, which involved the entire lung. In the mediastinum, 1 patient had lymph nodes larger than 1 cm, 3 had lymph nodes that were not enlarged but were more numerous than usual, and in the remaining patients no lymph nodes were found. The control CT's showed almost total resolution of the pulmonary infiltrates. Conclusion: The combination of eosinophilia and characteristic pulmonary infiltrates with a likely clinical presentation, associated with an optimal response to treatment with corticosteroids allows to make a reliable diagnosis and avoids the need for a pulmonary biopsy. (author)

  14. Finding Flow Experience in Music Activity

    Directory of Open Access Journals (Sweden)

    Dewi Sartika

    2014-03-01

    Full Text Available This research is aim to describe how one finding flow experience in his music activity, experiencing flow and feeling the impact of flow experience to his music career and life. The research method used is qualitative, intrinsic study case. The participants are two famous jazz musicians in Bandung, West Java, Indonesia. Data collecting used are in-depth interview, participant observation and document. The result shows that participant who has environment support especially from his music teacher is not only easier to find and experience flow, but also find happiness as impact of his flow experience. On the other hand, another participant who doesn’t have environment support especially from his family and have personality disposition to use his cognition, is struggling to find his flow experience in playing music, but then he finally find it when composing music.

  15. Radiographic findings of Proteus Syndrome

    Directory of Open Access Journals (Sweden)

    Nishant Mukesh Gandhi, MD

    2014-01-01

    Full Text Available The extremely rare Proteus Syndrome is a hamartomatous congenital syndrome with substantial variability between clinical patient presentations. The diagnostic criteria consist of a multitude of clinical findings including hemihypertrophy, macrodactyly, epidermal nevi, subcutaneous hamartomatous tumors, and bony abnormalities. These clinical findings correlate with striking radiographic findings.

  16. Aspectos radiográficos e ultra-sonográficos dos pacientes submetidos a alongamento ósseo pelo método de Ilizarov Radiographic and sonographic findings in patients submitted to limb lengthening using the Ilizarov method

    Directory of Open Access Journals (Sweden)

    Patrícia Martins e Souza

    2003-12-01

    Full Text Available Neste trabalho foram monitorados, por meio de radiografias simples e ultra-sonografias, dez pacientes submetidos a alongamento ósseo com o uso do fixador externo de Ilizarov, no período de março de 2001 a março de 2002. Os pacientes submetidos ao método de Ilizarov foram principalmente crianças e adolescentes, para correção de anomalias congênitas (seis casos. A correção do encurtamento se deveu a trauma complicado com osteomielite em três pacientes e a ressecção tumoral em um paciente. O fêmur esteve envolvido em 60% dos casos, a tíbia em 30% e a fíbula em 10%. Os achados radiográficos encontrados na evolução normal do regenerado ósseo foram um centro radiotransparente, ossificação linear, reação periosteal, aumento das partes moles e ossificação completa. Os achados da formação do osso novo na ultra-sonografia foram o regenerado anecóico, ecos esparsos no sítio de distração, ecos lineares alinhados longitudinalmente, ecos grosseiros e amorfos e calcificação completa. Ocorreram 15 complicações em seis pacientes: cisto no regenerado (cinco casos, infecção adjacente aos pinos (quatro casos, coleção em partes moles (três casos, consolidação precoce (dois casos e retardo na consolidação (um caso.Ten patients treated with Ilizarov external fixator for limb lengthening were monitored with radiographs and sonography examinations between March, 2001 and March, 2002. Most of the patients were children and adolescents who were submitted to surgery for correction of congenital deformities (six cases. In three patients shortening was secondary to post-traumatic osteomielitis and in one patient due to tumor resection. The femur was affected in 60%, tibia in 30% and fibula in 10% of the cases. The main radiographic findings of bone regeneration during the normal process of limb lengthening were lucent areas, linear ossification, periosteal reaction, soft tissue abnormalities and complete consolidation. Sonographic findings of new bone formation included anechoic areas, sparse echogenic foci within the distraction site, linear longitudinally oriented echogenic foci, amorphous and coarse echogenic foci and complete calcification. There were 15 complications in six patients: fluid collection at the distraction site (five cases, pin site infection (four cases, soft tissue collection (three cases, premature consolidation (two cases and delayed consolidation (one case.

  17. Gastric traumatic injuries: CT findings

    International Nuclear Information System (INIS)

    Objective: Gastric blunt traumatic injuries are uncommon and their radiological appearance has been infrequently reported in medical literature. These injuries are difficult to diagnose preoperatively, though they require immediate recognition to minimize their otherwise high mortality and morbidity. The aim of our study is to describe the radiological appearance of blunt gastric traumatic injuries. Materials and methods: Retrospective evaluation of a 25 patients series observed between January 1997 and May 2005. Results: We observed rupture of the stomach in 20% of cases, in 44% of cases a partial lesion of the stomach, in one case a necrotic post-traumatic volvulus, five patients (20%) had benign portal pneumatosis, in three patients the stomach was secondarily involved because of a diaphragmatic hernia. The fundus resulted to be the most frequently damaged part of the stomach (80%). Conclusions: Blunt traumatic injuries need a careful and systematic approach given their economical and social relevance. For these reasons uncommon lesions require attention and may be important to search for specific findings of gastric lesions

  18. Radiologic findings of osteochondritis dissecans

    International Nuclear Information System (INIS)

    To evaluate the radiographic characteristics of osteochondritis dissecans (OCD) and useful parameter for predicting mechanical stability, we retrospectively analysed 26 plain radiographic examinations and seven MR imagings in 28 cases of OCD in 24 patients. Typical radiologic findings were osteochondral defect with sclerotic rim of variable thickness and osteochondral fragment. Sites of osteochondral defect were medial (35.9%) or lateral (32%) femoral chondyle and medial (7.1%) or lateral (25%) side of talar dome. Sclerotic rim was seen in 24 cases (85%) and osteochondral fragments including nine loose bodies were seen in 21 cases (75%). The size of osteochondral defect with unstable fragment (average 2.05 cm) and loose body (2.04 cm) in the knee joint were similar to, but statistically larger than that with stable fragment (1.35 cm). All osteochondral defects were well visualized on MR images. Abnormalities of articular cartilage and effusion in the interface between the parent bone and fragment were seen in five cases of which there were confirmed three unstable cases arthroscopically. We concluded that size of defect may be a good parameter for predicting mechanical stability and MRI may be useful in the diagnosis of OCD and determining the methods of treatment

  19. MR findings in intralabyrinthine schwannomas

    Energy Technology Data Exchange (ETDEWEB)

    Montague, Mary-Louise; Kishore, Ameet; Hadley, Donald M.; O' Reilly, Brian

    2002-05-01

    AIM: Intralabyrinthine schwannomas (ILS) are rare benign tumours. They are not always recognized on routine magnetic resonance imaging (MRI). We aimed to study the clinical presentation and MRI findings in our patients with ILS. MATERIALS AND METHODS: Retrospective analysis of patients with vestibular schwannomas treated at this center. RESULTS: Of 144 vestibular schwannomas studied at this centre, three patients had an ILS. The most common presenting symptoms were unilateral hearing loss, tinnitus and vertigo. Two patients demonstrated a progressive sensorineural hearing loss (SNHL). The third patient had a severe SNHL at presentation. MRI enhanced with contrast medium was positive in the two patients with progressive SNHL and negative in the patient with the severe SNHL. CONCLUSION: This series demonstrates the ability of MRI to identify schwannomas filling the labyrinth, and also its inability to identify extremely small ILS. It underlines the importance of sending the cristae of patients undergoing labyrinthectomy for presumed Meniere's disease for histological examination. Montague, M.-L. et al. (2002)

  20. MR findings in intralabyrinthine schwannomas

    International Nuclear Information System (INIS)

    AIM: Intralabyrinthine schwannomas (ILS) are rare benign tumours. They are not always recognized on routine magnetic resonance imaging (MRI). We aimed to study the clinical presentation and MRI findings in our patients with ILS. MATERIALS AND METHODS: Retrospective analysis of patients with vestibular schwannomas treated at this center. RESULTS: Of 144 vestibular schwannomas studied at this centre, three patients had an ILS. The most common presenting symptoms were unilateral hearing loss, tinnitus and vertigo. Two patients demonstrated a progressive sensorineural hearing loss (SNHL). The third patient had a severe SNHL at presentation. MRI enhanced with contrast medium was positive in the two patients with progressive SNHL and negative in the patient with the severe SNHL. CONCLUSION: This series demonstrates the ability of MRI to identify schwannomas filling the labyrinth, and also its inability to identify extremely small ILS. It underlines the importance of sending the cristae of patients undergoing labyrinthectomy for presumed Meniere's disease for histological examination. Montague, M.-L. et al. (2002)

  1. An Investigation of the Academic Information Finding and Re-finding Behavior on the Web

    Directory of Open Access Journals (Sweden)

    Hsiao-Tieh Pu

    2014-12-01

    Full Text Available Academic researchers often need and re-use relevant information found after a period of time. This preliminary study used various methods, including experiments, interviews, search log analysis, sequential analysis, and observation to investigate characteristics of academic information finding and re-finding behavior. Overall, the participants in this study entered short queries either in finding or re-finding phases. Comparatively speaking, the participants entered greater number of queries, modified more queries, browsed more web pages, and stayed longer on web pages in the finding phase. On the other hand, in the re-finding phase, they utilized personal information management tools to re-find instead of finding again using search engine, such as checking browsing history; moreover, they tend to input less number of queries and stayed shorter on web pages. In short, the participants interacted more with the retrieval system during the finding phase, while they increased the use of personal information management tools in the re-finding phase. As to the contextual clues used in re-finding phase, the participants used less clues from the target itself, instead, they used indirect clues more often, especially location-related information. Based on the results of sequential analysis, the transition states in the re-finding phase was found to be more complex than those in the finding phase. Web information finding and re-finding behavior is an important and novel area of research. The preliminary results would benefit research on Web information re-finding behavior, and provide useful suggestions for developing personal academic information management systems. [Article content in Chinese

  2. Validation of the Martin Method for Estimating Low-Density Lipoprotein Cholesterol Levels in Korean Adults: Findings from the Korea National Health and Nutrition Examination Survey, 2009-2011

    Science.gov (United States)

    Lee, Jongseok; Jang, Sungok; Son, Heejeong

    2016-01-01

    Despite the importance of accurate assessment for low-density lipoprotein cholesterol (LDL-C), the Friedewald formula has primarily been used as a cost-effective method to estimate LDL-C when triglycerides are less than 400 mg/dL. In a recent study, an alternative to the formula was proposed to improve estimation of LDL-C. We evaluated the performance of the novel method versus the Friedewald formula using a sample of 5,642 Korean adults with LDL-C measured by an enzymatic homogeneous assay (LDL-CD). Friedewald LDL-C (LDL-CF) was estimated using a fixed factor of 5 for the ratio of triglycerides to very-low-density lipoprotein cholesterol (TG:VLDL-C ratio). However, the novel LDL-C (LDL-CN) estimates were calculated using the N-strata-specific median TG:VLDL-C ratios, LDL-C5 and LDL-C25 from respective ratios derived from our data set, and LDL-C180 from the 180-cell table reported by the original study. Compared with LDL-CF, each LDL-CN estimate exhibited a significantly higher overall concordance in the NCEP-ATP III guideline classification with LDL-CD (p< 0.001 for each comparison). Overall concordance was 78.2% for LDL-CF, 81.6% for LDL-C5, 82.3% for LDL-C25, and 82.0% for LDL-C180. Compared to LDL-C5, LDL-C25 significantly but slightly improved overall concordance (p = 0.008). LDL-C25 and LDL-C180 provided almost the same overall concordance; however, LDL-C180 achieved superior improvement in classifying LDL-C < 70 mg/dL compared to the other estimates. In subjects with triglycerides of 200 to 399 mg/dL, each LDL-CN estimate showed a significantly higher concordance than that of LDL-CF (p< 0.001 for each comparison). The novel method offers a significant improvement in LDL-C estimation when compared with the Friedewald formula. However, it requires further modification and validation considering the racial differences as well as the specific character of the applied measuring method. PMID:26824910

  3. A Medoid-based Method for Clustering Categorical Data

    Directory of Open Access Journals (Sweden)

    Ali Seman

    2013-01-01

    Full Text Available Medoid-based method is an alternative technique to centroid-based method for partitional clustering algorithms. This method has been incorporated in a recently introduced clustering algorithm for categorical data, called k-Approximate Modal Haplotype (k-AMH algorithm. This study reports the performance evaluation between the medoid-based method represented by the k-AMH algorithm and the centroid-based method represented by the extended k-Mode algorithm, the k-Population algorithm and the new Fuzzy k-Mode algorithm in clustering common categorical data. Nine common categorical data sets were used in the experiments to compare the performance of both methods using clustering accuracy scores. In overall results, the medoid-based method of k-AMH algorithm produced significant results for all data sets. The method showed its advantage of obtaining the highest clustering accuracy of 0.94 when clustering large number of clusters. This result indicated that the medoid-based method has a significant contribution for clustering categorical data, particularly for clustering large number of clusters.

  4. Mental Findings in Trauma Victims

    Directory of Open Access Journals (Sweden)

    ?smail Özgür CAN

    2013-09-01

    Full Text Available Introduction: In medico-legal evaluation of trauma patients, the bio-psychological effects of the trauma and the severity of the injuries require to be evaluated. In this study, assuming the fact that psychiatric assessment are not taken into consideration in physical trauma cases, we have planned to bring up the presence of psychological trauma in our medico-legally evaluated patients due to different types of traumas and review the mental findings and diagnoses in trauma victims.Methods: We retrospectively analyzed the hospital records of 1975 patients aged 18 years or older who presented to the Department of Forensic Medicine at Dokuz Eylul University School of Medicine for medico-legal evaluation between 1999 and 2009. Psychiatric assessment was performed in 142 patients by Consultation and Liaison Psychiatry Section of the university hospital. Data contained in medico-legal reports and patient records were then examined with respect to patients’ age, gender, nature of traumatic events, psychiatric diagnoses, descriptive characteristics of patients, severity of trauma, and past history of mental disorder and trauma experience. Results of the medico-legal evaluations were also analyzed.Results: Of the 142 patients, 80 (56.3% were female and their average age was 40.30±17.17 years. The most frequent traumatic events were traffic accidents (29.6% and violence-related blunt force trauma (28.9%. The distribution of foremost psychiatric diagnoses were anxiety disorders in 69 cases (48.6%, adjustment disorders in 16 cases (11.3% and mood disorders in 12 cases (8.5%. Among anxiety disorders, acute stress disorder (n=39 and post-traumatic stress disorder (PTSD (n=27 were the most accounted ones. In 27 cases of the 142, it was determined that, psychiatric symptoms and findings did not cover the diagnostic criteria. Being diagnosed as having a psychiatric disorder did not significantly associated with traumatic experiences, comorbidity, marriage status, education level, and lack of health insurance. Conclusion: We assume that, the presence of a psychological trauma is crucial to be introduced not only for the health benefit but also for legal rights of the patient. The necessity of considering merely the international diagnostic criteria in determining the existence of psychiatric trauma and its severity level can bring forth some difficulties in medico-legal evaluation. (Archives of Neuropsychiatry 2012; 49: 230-236Conflict of interest: The authors report ed no conflict of interest related to this article

  5. Oral tuberculosis: unusual radiographic findings

    OpenAIRE

    Sansare, K; Gupta, A; Khanna, V.; Karjodkar, F

    2011-01-01

    Oral tuberculosis and its radiographic findings are not commonly encountered in an oral and maxillofacial radiology practice. Literature has occasional mention of the radiographic findings of oral tuberculosis, which are still ambiguous. When affected, it is manifested majorly in the oral mucosa and rarely in the jaw bones. Here, we report certain unusual radiographic findings of oral tuberculosis which have been rarely mentioned in the literature. Four illustrative cases describe bony resorp...

  6. CT findings of infant epilepsy

    International Nuclear Information System (INIS)

    CT diagnosis of infantile epilepsy was evaluated. High incidence of abnormal CT findings in infantile spasms and Lennox-Gastaut syndrome was same as in other reports. Comparison between CT findings and neurological complications and that between CT findings and electroencephalogram findings revealed a stronger relationship existing in the former. This suggested that CT is more useful as a measure to detect underlying diseases which are due to organic change of the brain to cause epilepsy, rather than as that to disclose epileptic primary lesions of functional change. (Ueda, J.)

  7. A Blind Method to Detrend Instrumental Systematics in Exoplanetary Light Curves

    Science.gov (United States)

    Morello, G.

    2015-07-01

    The study of the atmospheres of transiting exoplanets requires a photometric precision, and repeatability, of one part in ?104. This is beyond the original calibration plans of current observatories, hence the necessity to disentangle the instrumental systematics from the astrophysical signals in raw data sets. Most methods used in the literature are based on an approximate instrument model. The choice of parameters of the model and their functional forms can sometimes be subjective, causing controversies in the literature. Recently, Morello et al. (2014, 2015) have developed a non-parametric detrending method that gave coherent and repeatable results when applied to Spitzer/IRAC data sets that were debated in the literature. Said method is based on independent component analysis (ICA) of individual pixel time-series, hereafter “pixel-ICA”. The main purpose of this paper is to investigate the limits and advantages of pixel-ICA on a series of simulated data sets with different instrument properties, and a range of jitter timescales and shapes, non-stationarity, sudden change points, etc. The performances of pixel-ICA are compared against the ones of other methods, in particular polynomial centroid division, and pixel-level decorrelation method. We find that in simulated cases pixel-ICA performs as well or better than other methods, and it also guarantees a higher degree of objectivity, because of its purely statistical foundation with no prior information on the instrument systematics. The results of this paper, together with previous analyses of Spitzer/IRAC data sets, suggest that photometric precision and repeatability of one part in 104 can be achieved with current infrared space instruments.

  8. Associations between spondyloarthritis features and MRI findings

    DEFF Research Database (Denmark)

    Arnbak, Bodil; Jurik, Anne Grethe; Hørslev-Petersen, Kim; Hendricks, Oliver; Hermansen, Louise Thuesen; Loft, Anne Gitte; Østergaard, Mikkel; Pedersen, Susanne Juhl; Zejden, Anna; Egund, Niels; Holst, René; Manniche, Claus; Jensen, Tue Secher

    2015-01-01

    clinical features and MRI findings included in ASAS criteria, and 2) explore the associations between clinical features and MRI findings. METHODS: Patients aged 18-40 years with persistent LBP referred to an outpatient spine clinic were included. Information on clinical features (incl. HLA-B27 and CRP) and...... MRI findings of the spine and sacroiliac joints (SIJ) were collected. RESULTS: Of 1020 included patients, 537(53%) had minimum one clinical feature. Three clinical features were common; inflammatory back pain, good response to NSAID and family disposition (15-17% each). MRI sacroiliitis, according to...... ASAS definition, was present in 217(21%) patients. Of those, 91(42%) had bone marrow oedema (BMO) at the minimum requirement according to ASAS (low BMO score). HLA-B27, peripheral arthritis, good response to NSAID, and preceding infection associated independently with SIJ MRI findings (OR range 1...

  9. The multidimensional evaluation and treatment of anxiety in children and adolescents: rationale, design, methods and preliminary findings / Avaliação multidimensional e tratamento da ansiedade em crianças e adolescentes: marco teórico, desenho, métodos e resultados preliminares

    Scientific Electronic Library Online (English)

    Giovanni Abrahão, Salum; Luciano Rassier, Isolan; Vera Lúcia, Bosa; Andrea Goya, Tocchetto; Stefania Pigatto, Teche; Ilaine, Schuch; Jandira Rahmeier, Costa; Marianna de Abreu, Costa; Rafaela Behs, Jarros; Maria Augusta, Mansur; Daniela, Knijnik; Estácio Amaro, Silva; Christian, Kieling; Maria Helena, Oliveira; Elza, Medeiros; Andressa, Bortoluzzi; Rudineia, Toazza; Carolina, Blaya; Sandra, Leistner-Segal; Jerusa Fumagalli de, Salles; Patrícia Pelufo, Silveira; Marcelo Zubaran, Goldani; Elizeth, Heldt; Gisele Gus, Manfro.

    2011-06-01

    Full Text Available OBJETIVO: o objetivo deste estudo é descrever o desenho, os métodos e as características amostrais da Avaliação Multidimensional e Tratamento da Ansiedade em Crianças e Adolescentes - Projeto PROTAIA. MÉTODO: Escolares entre 10 e 17 anos de todas as escolas pertencentes à área de abrangência da unid [...] ade de atenção primária do Hospital de Clínicas de Porto Alegre foram incluídos no projeto. O projeto compreende cinco fases: 1) triagem comunitária; 2) diagnóstico psiquiátrico; 3) avaliação multidimensional, incluindo fatores ambientais, neuropsicológicos, nutricionais e marcadores biológicos; 4) tratamento; e 5) fase translacional. RESULTADOS: Um total de 2.457 sujeitos foram triados para transtornos de ansiedade na comunidade. Dos indivíduos que compareceram à avaliação diagnóstica, 138 foram detectados com ao menos um transtorno de ansiedade (excluindo fobia específica) e 102 indivíduos sem nenhum transtorno de ansiedade. Dentre os casos de ansiedade, o transtorno de ansiedade generalizada (n = 95; 68,8%), transtorno de ansiedade social (n = 57; 41,3%) e o transtorno de ansiedade de separação (n = 49; 35,5%) foram os mais frequentes. CONCLUSÃO: O projeto PROTAIA é um projeto de pesquisa promissor que pode contribuir para o entendimento da relação entre transtornos de ansiedade e fenótipos relacionados à ansiedade com vários fatores de risco, tanto genéticos quanto ambientais. Abstract in english OBJECTIVE: This study aims to describe the design, methods and sample characteristics of the Multidimensional Evaluation and Treatment of Anxiety in Children and Adolescents - the PROTAIA Project. METHOD: Students between 10 and 17 years old from all six schools belonging to the catchment area of th [...] e Primary Care Unit of Hospital de Clínicas de Porto Alegre were included in the project. It comprises five phases: (1) a community screening phase; (2) a psychiatric diagnostic phase; (3) a multidimensional assessment phase evaluating environmental, neuropsychological, nutritional, and biological factors; (4) a treatment phase, and (5) a translational phase. RESULTS: A total of 2,457 subjects from the community were screened for anxiety disorders. From those who attended the diagnostic interview, we identified 138 individuals with at least one anxiety disorder (apart from specific phobia) and 102 individuals without any anxiety disorder. Among the anxiety cases, generalized anxiety disorder (n = 95; 68.8%), social anxiety disorder (n = 57; 41.3%) and separation anxiety disorder (n = 49; 35.5%) were the most frequent disorders. CONCLUSION: The PROTAIA Project is a promising research project that can contribute to the knowledge of the relationship between anxiety disorders and anxiety-related phenotypes with several genetic and environmental risk factors.

  10. Post-therapeutic imaging findings.

    Science.gov (United States)

    Pollice, Saverio; Muto, Mario; Scarabino, Tommaso

    2015-05-01

    Any surgical approach modifies the normal anatomical and functional arrangement of the segmental spine which is aimed, therefore image interpretation cannot ignore a correct set of knowledge in the field of anatomy, pathophysiology, drug compliance, interventional radiology and surgery. Neuroradiological imaging has an important role before surgery to direct the surgeon or interventional radiologist during the operation, both in post-surgery, where imaging examination can rightly evaluate properties and effects of the treatment and can detect potential complications as infections, abscess, bleeding, exuberant scar, mobilization and rupture of devices. The available methods of imaging are the X-rays (XR) made at least in two projections, Computed Tomography (CT) with MPR (multiplanar) and VR (volume rendering) reconstruction, and Magnetic Resonance (MR), often performed before and after contrast media injection. Imaging assessment of spine after surgery is complex and depends upon several factors, including surgical procedures and disease for which it was performed; biomechanical of the underlying cortical and cancellous bone findings; conditions of muscles, intervertebral disk and ligaments; time since surgery procedures; duration and nature of the post-surgical syndrome. Depending upon several factors, one or a combination of complementary imaging modalities (X-rays, Computed Tomography, Magnetic Resonance) may be required to evaluate effectiveness of the treatment; to demonstrate any clinically relevant abnormality at the treated region and adjacent structures (complications such as inflammation, abscesses, bleeding and misplacement of the device); to assist the interventional radiologist or surgeon in deciding if is necessary intervene again, in which nature and in which vertebral level(s). PMID:25017151

  11. Isolated perihepatic tuberculosis: imaging findings

    International Nuclear Information System (INIS)

    Aim: To review the imaging findings of isolated perihepatic tuberculosis without coexistent active tuberculosis elsewhere in the body. Materials and methods: Over a 9-year period, six patients with histopathologically proven perihepatic tuberculosis without simultaneous active tuberculosis elsewhere in the body were included in this study. Two radiologists retrospectively evaluated in consensus the location (right, left, or both perihepatic spaces), size (maximum diameter), morphology (ovoid or round), number, attenuation (low-, iso-, or high-attenuation compared with the adjacent liver parenchyma), and the presence or absence of contrast enhancement of the lesions on computed tomography (CT), and echogenicity (low-, iso-, or high-echogenicity compared with the adjacent liver parenchyma) of the lesions on ultrasonography. Results: On CT, an isolated perihepatic lesion was located in the right perihepatic space in five patients, whereas three lesions were located in both perihepatic spaces in the remaining patient. The mean maximum diameter of the isolated perihepatic tuberculosis lesions was 29.7 mm. Isolated perihepatic tuberculosis appeared as an ovoid-shaped, homogeneous, and low-attenuating (n = 5) or high-attenuating (n = 1) lesion relative to the liver. There was peripheral rim enhancement of the lesion in two patients. On ultrasonography, isolated perihepatic tuberculosis was revealed as a homogeneous, low-echoic (n = 5) or iso-echoic (n = 1) lesion relative to the liver. Conclusion: Although various inflammatory or malignant lesions can be located in the perihepatic space, isolated perihepatic tuberculosis appears an ovoid-shaped, homogeneous, and low-attenuating or low-echoic lesion compared with the liver parenchyma on CT or ultrasonography

  12. Finding Maximal Pairs with Bounded Gap

    DEFF Research Database (Denmark)

    Brodal, Gerth StØlting; LyngsØ, Rune B.

    1999-01-01

    A pair in a string is the occurrence of the same substring twice. A pair is maximal if the two occurrences of the substring cannot be extended to the left and right without making them different. The gap of a pair is the number of characters between the two occurrences of the substring. In this paper we present methods for finding all maximal pairs under various constraints on the gap. In a string of length n we can find all maximal pairs with gap in an upper and lower bounded interval in time O(n log n+z) where z is the number of reported pairs. If the upper bound is removed the time reduces to O(n+z). Since a tandem repeat is a pair where the gap is zero, our methods can be seen as a generalization of finding tandem repeats. The running time of our methods equals the running time of well known methods for finding tandem repeats.

  13. Aetiology of Autism: Findings and Questions

    Science.gov (United States)

    Rutter, M.

    2005-01-01

    Background Although there is good evidence that autism is a multifactorial disorder, an adequate understanding of the genetic and non-genetic causes has yet to be achieved. Methods Empirical research findings and conceptual reviews are reviewed with respect to evidence on possible causal influences. Results Much the strongest evidence concerns the…

  14. MRI Findings In Dengue Encephalitis

    Directory of Open Access Journals (Sweden)

    Ashraf V.V

    2004-01-01

    Full Text Available Neurological manifestations are rare in dengue fever. Two cases with encephalopathy and systemic features of dengue fever with abnormal CSF and MR imaging are reported. Striking MRI finding was bilateral symmetrical thalamic lesions similar to those reported in Japanese encephalitis. This report highlights that MRI findings can be similar in dengue and Japanese encephalitis.

  15. Initial findings from a mixed-methods evaluation of computer-assisted therapy for substance misuse in prisoners: Development, implementation and clinical outcomes from the ‘Breaking Free Health & Justice’ treatment and recovery programme

    Directory of Open Access Journals (Sweden)

    Sarah Elison

    2015-08-01

    Full Text Available Background: Within the United Kingdom’s ‘Transforming Rehabilitation’ agenda, reshaping drug and alcohol interventions in prisons is central to the Government’s approach to addressing substance dependence in the prison population and reduce reoffending. To achieve this, a through-care project to support offenders following release, ‘Gateways’, is taking place providing ‘through the gate’ support to released offenders, including help with organising accommodation, education and employment, and access to a peer supporter. In addition, Gateways is providing access to an evidence-based computer-assisted therapy (CAT programme for substance misuse, Breaking Free Health & Justice (BFHJ. Developed in partnership with the Ministry of Justice (MoJ National Offender Management Services (NOMS, and based on a community version of the programme, Breaking Free Online (BFO, BFHJ provides access to clinically-robust techniques based on cognitive behavioural therapy (CBT and promotes the role of technology-enhanced approaches in recovery from substance misuse. The BFHJ programme is provided via ‘Virtual Campus’ (VC, a secure, web-based learning environment delivered by NOMS and the Department for Business, Innovation and Skills, which has no links to websites not approved by MoJ, and provides prisoners with access to online training courses around work and skills. Providing BFHJ on VC makes the programme the world’s first online healthcare programme to be provided in prisons. Aims: Although here is an emerging evidence-base for the effectiveness of the community version of the BFO programme and its implementation within community treatment settings (Davies, Elison, Ward, & Laudet, 2015; Elison, Davies, & Ward, 2015a, 2015b; Elison, Humphreys, Ward, & Davies, 2013; Elison, Ward, Davies, Lidbetter, et al., 2014; Elison, Ward, Davies, & Moody, 2014, its potential within prison settings requires exploration. This study therefore sought to examine the processes of implementation of this novel digital health programme and the various barriers and facilitators of this, including the practicalities of providing an online treatment programme in an environment in which there are multiple, complex security requirements and considerations. Additionally, the acceptability of the BFHJ programme to prisoners who may have limited experience of using online technologies was also explored. Clinical outcomes in terms of the programmes impact on substance dependence and use were also examined. Methods: In line with the Medical Research Council (MRC guidelines around development and evaluation of complex interventions (Craig et al., 2008, a mixed-methods approach was used including a qualitative study to explore the implementation of this online treatment programme within the secure prison environment, and offender perceptions of this novel, technology-enhanced approach to substance misuse treatment. In addition, quantitative data derived from a battery of standardised psychometric assessments was used to examine clinical effectiveness of BFHJ. Results: In order to meet MoJ security requirements prior to implementation, the BFHJ programme had to be reviewed and ‘white listed’ by NOMS and their security partner XMA to ensure the programme met all security, quality and information assurance processes and standards. This was a lengthy and costly process that entailed freshly developing the programme in partnership with VC experts at NOMS to ensure the programme is ‘sterile’ i.e., there are no holes in the system or links to external websites – this comprised some aspects of the programme content and resulted in some clinical techniques requiring reworking e.g., removing Google maps from one section of the programme. Themes emerging from qualitative data around offenders experiences of BFHJ illustrate its potential for use in prison settings and also to provide, for the first time, genuine continuity of care during transfer between different prisons and upon release from prison into the community, given prisone

  16. Chest radiographic findings of leptospirosis

    International Nuclear Information System (INIS)

    1. A study on chest radiographic findings of 54 cases with pneumonia like symptoms was performed. Of 54 cases, 8 cases were confirmed to be leptospirosis and 7 cases were leptospirosis combined with Korean hemorrhagic fever. 2. Of 8 cases of leptospirosis, 4 cases showed abnormal chest radiographic findings: acinar nodular type 2, massive confluent consolidation type 2. Of 7 cases of leptospirosis combined with Korean hemorrhagic fever: acinar nodular type 3, massive confluent consolidation type 1, and increased interstitial markings type 1 respectively. 3. It was considered to be difficult to diagnose the leptospirosis on chest radiographic findings alone, especially the case combined with Korean hemorrhagic fever.

  17. CT findings of necrotizing pneumonia

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Hyae Young; Im, Jung Gi; Whang, Sung Il; Cheon, Jung Eun; Lee, Jae Kyo; Song, Jae Woo [Seoul National Univ. College of Medicine, Seoul (Korea, Republic of)

    1998-07-01

    Necrotizing pneumonia causes necrosis of pulmonary parenchyma and may lead to pulmonary gangrene. Prior to the antibiotic era, extensive pulmonary involvement was potentially fatal, but the incidence of necrotizing pneumoniais now less common. On contrast-enhanced CT scans, consolidation with contrast enhancement containing necrotic foci with low attenuation and cavities is characteristic. Radiologic findings do not differ according to the causative organism and in most of cases, specific diagnosis may be impossible. Clinical findings and certain characteristic radiologic findings may be helpful for narrowing the differential diagnosis. We illustrate the clinical and radiologic characteristics of necrotizing pneumonia according to causative bacterial organisms.

  18. CT findings of pulmonary aspergillosis

    International Nuclear Information System (INIS)

    The fungus aspergillus can cause a variety of pulmonary disorders. Aspergilloma is a noninvasive aspergillus colonization of virtually any type of preexisting pulmonary cavity or cystic space. Invasive pulmonary aspergillosis is serious, usually fatal infection in patients being treated with immunosuppressants or who have chronic debilitating disease. Allergic bronchopulmonary aspergillosis is characterized clinically by asthma, blood and sputum eosinophilia and positive immunologic reaction to aspergillus antigen. Awareness of the radiographic and CT findings of pulmonary aspergillosis is important in making the diagnosis of aspergillus-caused pulmonary disorders. In this pictorial essay, we illustrated various radiological findings of pulmonary aspergillosis focused on CT findings correlated with gross pathologic specimens

  19. Chest radiographic findings of leptospirosis

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Mee Hyun; Jung, Hee Tae; Lee, Young Joong; Yoon, Jong Sup [Hallym University College of Medicine, Seoul (Korea, Republic of)

    1986-04-15

    1. A study on chest radiographic findings of 54 cases with pneumonia like symptoms was performed. Of 54 cases, 8 cases were confirmed to be leptospirosis and 7 cases were leptospirosis combined with Korean hemorrhagic fever. 2. Of 8 cases of leptospirosis, 4 cases showed abnormal chest radiographic findings: acinar nodular type 2, massive confluent consolidation type 2. Of 7 cases of leptospirosis combined with Korean hemorrhagic fever: acinar nodular type 3, massive confluent consolidation type 1, and increased interstitial markings type 1 respectively. 3. It was considered to be difficult to diagnose the leptospirosis on chest radiographic findings alone, especially the case combined with Korean hemorrhagic fever.

  20. Cystic intrapulmonary lymphangioma: HRCT findings

    International Nuclear Information System (INIS)

    We report a rare case of cystic intrapulmonary lymphangioma involving the left lung, which presented with pneumothorax and respiratory distress in a 6-month-old infant. Chest radiographs showed a multicystic lesion in the left lung mimicking the features of congenital cystic adenomatoid malformation of the lung. The lesion appeared on high-resolution CT (HRCT) as a multiseptate, air-filled cystic lesion in the left hilar area. Associated HRCT findings were thickening of interlobular septa and bronchovascular bundles in the left lung and the presence of peripheral pulmonary vessels within cystic lesions in the apex of the left lung. HRCT findings correlated well with histopathologic findings. We suggest that these associated findings may be helpful in distinguishing this condition from other cystic lung diseases and that this entity should be included in the differential diagnosis of multicystic lung lesions. (orig.)

  1. Find a Registered Dietitian Nutritionist

    Science.gov (United States)

    ... Complicated vegetables on forks - Vegetarianism: The Basic Facts Vegetarianism: The Basic Facts freezer of processed foods Processed Foods: What's OK, What to Avoid Health Health Find out more Categories Lifestyle Weight Loss ...

  2. Find an Allergist/Immunologist

    Science.gov (United States)

    ... Republic Chad Chile Christmas Island Cocos (Keeling) Islands Colombia Comoros Cook Islands Costa Rica Cote d'Ivoire ... meeting Browse your conditions Check pollen counts Continuing education center Find an allergist / immunologist Journals Login / My ...

  3. Roentgen findings in cheirolumbar dysostosis

    International Nuclear Information System (INIS)

    Constitutional stenosis of the lumbar vertebral canal and brachycheiria (brachymetacarpia/brachyphalangia) together form cheirolumbar dysostosis (no. 2692 of the Birth Defects Encyclopedia, 1987). Typical findings in the basic type and transitional forms are presented. (orig.)

  4. Global optimization for track finding

    International Nuclear Information System (INIS)

    Hopfield networks with mean-field annealing have been proposed for track finding in particle detectors by Peterson and Denby. In this paper we investigate and compare some other - probabilistic and heuristic - approaches to finding the global minimum of the associated energy function: Simulated annealing, threshold accepting, great deluge, record-to-record travel, and tabu search. We also use a branch-and-bound and a branch-and-cut algorithm in order to obtain the exact global minimum. (orig.)

  5. Rhombencephalosynapsis: CT and MRI findings

    Directory of Open Access Journals (Sweden)

    Mendonça J

    2004-01-01

    Full Text Available An unusual disorder of cerebellar development, rhombencephalosynapsis is a unique entity which presents with cerebellar fusion and absence of cerebellar vermis on imaging studies, often associated with supratentorial findings. No specific clinical syndrome has been described in these patients so far, and most cases are found in infancy and childhood. MRI and its multiplanar capabilities and high spatial and contrast resolution increased its recognition. Two cases are reported, with emphasis on imaging findings.

  6. Finding Lines under Bounded Error

    OpenAIRE

    Breuel, Thomas M.

    1993-01-01

    A new algorithm for finding straight lines in images under a bounded error model is described. The algorithm is based on a hierarchical and adaptive subdivision of the space of line parameters. It measures errors in image space and thereby guarantees that no solution satisfying the given error bounds will be lost. The algorithm can find interpretations of all the lines in the image that satisfy the constraint that each image feature supports at most one line hypothesis. It can be extended to ...

  7. Finding Maximal Pairs with Bounded Gap

    DEFF Research Database (Denmark)

    Brodal, Gerth Stølting; Lyngsø, Rune B.; Pedersen, Christian N. S.; Stoye, Jens

    1999-01-01

    A pair in a string is the occurrence of the same substring twice. A pair is maximal if the two occurrences of the substring cannot be extended to the left and right without making them different. The gap of a pair is the number of characters between the two occurrences of the substring. In this paper we present methods for finding all maximal pairs under various constraints on the gap. In a string of length n we can find all maximal pairs with gap in an upper and lower bounded interval in time O...

  8. Radiologic findings of granulomatous mastitis

    International Nuclear Information System (INIS)

    The describe the radiologic findings of granulomatous mastitis of the breast. This study included 19 patients (age range: 22 to 56 years; mean 37 years) with 22 lesions that were pathologically confirmed as having granulomatous mastitis. All the patients underwent a breast ultrasonography and 13 patients underwent a mammography. The results of the mammography revealed focal asymmetry (n = 9), multiple ill-defined isodense nodules (n 2), ill-defined nodular density on craniocaudal view (n = 1), and unremarkable finding (n = 1). The sonographic findings included continuous or discontinuous multiple tubular and nodular low echoic lesions (n = 7), ill-defined heterogeneously low echoic lesion (n = 5), irregular-shaped, ill-defined low echoic mass (n = 4), fluid collection with internal floating materials suggesting the presence of an abscess (n = 4), ill-defined heterogeneously low echoic lesion and abscess (n = 1), and multiple ill-defined nodules (n = 1). In the case of granulomatous mastitis, the mammography results indicate a lack of specificity between normal findings and focal asymmetry. The sonographic findings indicate that ill-defined heterogeneously low echoic lesions or irregular shaped, ill-defined low echoic masses are difficult to differentiate from breast cancer. The sonographic findings of abscesses indicate a difficulty in differentiating them from cases of pyogenic mastitis. However, multiple tubular and nodular low echoic lesions, especially with a continuous appearance, should point to granulomatous mastitis, and is helpful in its differential diagnosis and treatment

  9. Radiologic findings of granulomatous mastitis

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Tae Gyu; Kim, Ji Young; Jeong, Myeong Ja; Kim, Jae Hyung; Kim, Soung Hee; Kim, Soo Hyun; Jun, Woo Sun; Park, Kyeong Mee; Han, Se Hwan [Paik Hospital, Inje University College of Medicine, Seoul (Korea, Republic of)

    2008-08-15

    The describe the radiologic findings of granulomatous mastitis of the breast. This study included 19 patients (age range: 22 to 56 years; mean 37 years) with 22 lesions that were pathologically confirmed as having granulomatous mastitis. All the patients underwent a breast ultrasonography and 13 patients underwent a mammography. The results of the mammography revealed focal asymmetry (n = 9), multiple ill-defined isodense nodules (n 2), ill-defined nodular density on craniocaudal view (n = 1), and unremarkable finding (n = 1). The sonographic findings included continuous or discontinuous multiple tubular and nodular low echoic lesions (n = 7), ill-defined heterogeneously low echoic lesion (n = 5), irregular-shaped, ill-defined low echoic mass (n = 4), fluid collection with internal floating materials suggesting the presence of an abscess (n = 4), ill-defined heterogeneously low echoic lesion and abscess (n = 1), and multiple ill-defined nodules (n = 1). In the case of granulomatous mastitis, the mammography results indicate a lack of specificity between normal findings and focal asymmetry. The sonographic findings indicate that ill-defined heterogeneously low echoic lesions or irregular shaped, ill-defined low echoic masses are difficult to differentiate from breast cancer. The sonographic findings of abscesses indicate a difficulty in differentiating them from cases of pyogenic mastitis. However, multiple tubular and nodular low echoic lesions, especially with a continuous appearance, should point to granulomatous mastitis, and is helpful in its differential diagnosis and treatment.

  10. Finding Anomalous Periodic Time Series: An Application to Catalogs of Periodic Variable Stars

    CERN Document Server

    Rebbapragada, Umaa; Brodley, Carla E; Alcock, Charles; 10.1007/s10994-008-5093-3

    2009-01-01

    Catalogs of periodic variable stars contain large numbers of periodic light-curves (photometric time series data from the astrophysics domain). Separating anomalous objects from well-known classes is an important step towards the discovery of new classes of astronomical objects. Most anomaly detection methods for time series data assume either a single continuous time series or a set of time series whose periods are aligned. Light-curve data precludes the use of these methods as the periods of any given pair of light-curves may be out of sync. One may use an existing anomaly detection method if, prior to similarity calculation, one performs the costly act of aligning two light-curves, an operation that scales poorly to massive data sets. This paper presents PCAD, an unsupervised anomaly detection method for large sets of unsynchronized periodic time-series data, that outputs a ranked list of both global and local anomalies. It calculates its anomaly score for each light-curve in relation to a set of centroids...

  11. Near-Earth objects finding them before they find us

    CERN Document Server

    Yeomans, Donald K

    2012-01-01

    Of all the natural disasters that could befall us, only an Earth impact by a large comet or asteroid has the potential to end civilization in a single blow. Yet these near-Earth objects also offer tantalizing clues to our solar system's origins, and someday could even serve as stepping-stones for space exploration. In this book, Donald Yeomans introduces readers to the science of near-Earth objects--its history, applications, and ongoing quest to find near-Earth objects before they find us. In its course around the sun, the Earth passes through a veritable shooting gallery of million

  12. CT findings of focal organizing pneumonia: correlation with pathologic findings

    International Nuclear Information System (INIS)

    To evaluate the CT findings of focal organizing pneumonia and to correlate them with pathologic findings to help differentiating from lung cancer. We evaluated radiologic and pathologic findings of five patients with solitary pulmonary nodule which were confirmed as focal organizing pneumonia pathologically. On CT scan, focal organizing pneumonia had irregular margin contacting the pleura in all five cases. The shape of the nodules were spherical to wedge or elliptical and the size from 3.5cm to 5.5cm(average 4.2 cm) in largest diameter. On postcontrast CT scan, all nodules showed enhancement and four cases showed central low density components. Two nodules contained air within the nodule. In four cases, pleural changes such as effusion and/or focal thickening were noted. No lymphadenopathy was found in all cases. Pathologically, the enhancing portion on CT showed findings of organizing pneumonia such as granulation tissue with fibroblast proliferation in alveolar space and interstitial thickening. The central low density areas on CT were due to ischemic necrosis, abscess and exudate, transudate and infiltration of foamy histiocyte. The possibility of focal organizing pneumonia should be considered when peripherally located solitary pulmonary nodule had enhancing component with no combined lymphadenopathy on CT scan

  13. CT finding of cryptococcal meningitis

    International Nuclear Information System (INIS)

    We have experienced 14 cases of cryptococcal meningitis in the last 6 years. Their neurological signs, CT findings, and prognoses were studied. They fall into three types: the brain-stem-encephalitis type, the cortical-encephalitis type, and the meningitis type, according to the clinical course. The first type (6 cases) revealed mainly cerebellar signs, eye-movement damage, and so forth. The second type (5 cases) demonstrated ''Personality'' changes, chiefly aphasia. The third type (5 cases) did not show any focal signs. Prognosis of the brain-stem-encephalitis type was very poor, with a 50% mortality rate. In the survivors, also, clinical signs did not disappear for a long time. Repeated CT was performed in 13 among the 14 cases; abnormal CT findings were revealed in 5 cases because of cryptococcal infection. Granuloma shadow and ventriculitis shadow were observed in 3 cases each. These abnormal findings disappeared upon treatment except in one case. The clinical signs are not completely related with the CT finding, but it is useful that the site which has been infiltrated by the cryptococcus can be observed. Abnormal CT findings were observed in the 4 cases of the brain-stem-encephalitis type among the 5 abnormal cases. It is very useful to know the severity of the condition. (author)

  14. CT findings of renal abscess

    International Nuclear Information System (INIS)

    The purpose of this study is to determine characteristic CT findings in renal abscess. Twenty cases of renal abscess were retrospectively analyzed for CT findings relating to the shape and extent of the abscess, change of nephrogram, peripheral rim enhancement, wedge-shaped enhancement on delayed scans, enlargement of the kidney involved and associated findings. Seven patients had a renal abscess at the right kidney, nine at the lift kidney and two bilaterally. The abscesses were round in 18 cases and finger-like in two. Rim enhancement around renal abscess was seen in four cases (20%). Changes in the nephrogram around the abscess were seen in 12 cases (60%). In all six patients who had undergone delayed postcontrast scans, wedge-shaped enhancement was shown around the abscess (100%). In the observation of the extent of renal abscesses, 14 cases were within the kidney, six cases extended the beyond renal capsule, and two were loculated in the renal fascia itself. Renal enlargement was seen in nine cases (45%). These results suggest that CT findings such as delayed wedge-shaped enhancement, change of nephrogram, peripheral rim enhancement, renal enlargement, and associated findings are valuable for diagnosis, and that CT also gives information concerning the extent, evolution and complication of a renal abscess

  15. MR findings of cerebral palsy

    International Nuclear Information System (INIS)

    To evaluate the MR findings of brain damage in cerebral palised patients and to correlate it with gestational age and the time of damage. A retrospective analysis was performed in 40 patients who underwent MR scanning for evaluation of brain lesion in clinically diagnosed cerebral palsy. Authors classified the patients into two groups as premature and full-term and compared MR findings of the two groups. Abnormal MR findings were noted in 28 cases (70%). Five out of 6 patients who had been born prematurely showed isolate periventricular white matter lesions. Twenty-three out of 34 patients who had been born at full-term showed abnormal MR findings. Of these 23 patients, migration anomalies in 7 patients, isolate periventricular white matter lesions in 3 patients, and other combined periventricular subcortical white matter and deep gray matter lesions in 14 patients were seen. At least, 10 patients(43%) of full term group showed abnormal MRI findings reflecting intrauterine brain damage and all 5 patients of premature group showed isolate periventricular white matter lesions suggesting immaturity of brain. MRI is thought to be very useful in the assessment of brain damage for the patients with cerebral palsy by recognizing the location of the lesion and estimating the time of damage

  16. Cranial CT findings in patients with meningomyelocele.

    Science.gov (United States)

    Zimmerman, R D; Breckbill, D; Dennis, M W; Davis, D O

    1979-04-01

    The association between meningomyelocele and various cranial abnormalities, particularly Chiari II malformation is well established. Cranial CT scans in 47 patients with meningomyelocele proved to be a safe and effective method of elucidating the type and extent of anatomic abnormalities associated with this disorder, and evaluating and following the degree of hydrocephalus seen in these patients. Of the 47 patients, 43 (92%) showed CT findings indicative of an abnormally low fourth ventricle, the hallmark finding in Chiari II malformation. In 67% the fourth ventricle was not visualized, and in 25% it was directly visualized in an abnormally caudal position. Other findings included hydrocephalus (85%), a striking and possibly unique heart-shaped psuedomass in the posterior fossa (58%), and abnormal configuration of the lateral ventricles ("vampire bat" configuration). Calvarial abnormalities, in particular lacunar skull, were also noted at CT. PMID:106696

  17. MRI findings in the painful hemiplegic shoulder

    Energy Technology Data Exchange (ETDEWEB)

    Tavora, D.G.F., E-mail: danielgurgel@sarah.b [Department of Radiology, Sarah Network of Hospitals for Rehabilitation, Fortaleza (Brazil); Gama, R.L.; Bomfim, R.C. [Department of Radiology, Sarah Network of Hospitals for Rehabilitation, Fortaleza (Brazil); Nakayama, M. [Department of Radiology, Federal University of Grande Dourados, Dourados (Brazil); Silva, C.E.P. [Department of Statistics, Sarah Network of Hospitals for Rehabilitation, Fortaleza (Brazil)

    2010-10-15

    Aim: To evaluate the magnetic resonance imaging (MRI) findings in painful hemiplegic shoulder (PHS) in hemiplegic post-stroke patients. Materials and methods: Patients with hemiplegia following their first cerebrovascular accident who were admitted to the Sarah Network of Hospitals for Rehabilitation were studied. Forty-five patients with pain in the hemiplegic shoulder and 23 post-stroke patients without shoulder pain were investigated. MRI and radiographic findings of the hemiplegic and contralateral asymptomatic shoulders were evaluated. Results: Some MRI findings were more frequent in PHS group, including synovial capsule thickening, synovial capsule enhancement, and enhancement in the rotator cuff interval. Conclusions: Adhesive capsulitis was found to be a possible cause of PHS.

  18. MRI findings in the painful hemiplegic shoulder

    International Nuclear Information System (INIS)

    Aim: To evaluate the magnetic resonance imaging (MRI) findings in painful hemiplegic shoulder (PHS) in hemiplegic post-stroke patients. Materials and methods: Patients with hemiplegia following their first cerebrovascular accident who were admitted to the Sarah Network of Hospitals for Rehabilitation were studied. Forty-five patients with pain in the hemiplegic shoulder and 23 post-stroke patients without shoulder pain were investigated. MRI and radiographic findings of the hemiplegic and contralateral asymptomatic shoulders were evaluated. Results: Some MRI findings were more frequent in PHS group, including synovial capsule thickening, synovial capsule enhancement, and enhancement in the rotator cuff interval. Conclusions: Adhesive capsulitis was found to be a possible cause of PHS.

  19. Comparison of preoperative neuroradiographic findings and surgical findings in lumbar disc herniation

    Energy Technology Data Exchange (ETDEWEB)

    Takahara, Kazuhiro; Sera, Keisuke; Nakamura, Masakazu; Uchida, Takeshi [Nagasaki Mitsubishi Hospital (Japan); Ito, Nobuyuki

    1997-09-01

    Surgical findings in lumbar disc hernia were compared to pre-operative MRI, CTM and myelogram findings. Ninety-one cases were studied using Love`s method. The accuracy of hernia diagnosis in MRI was 59.3%, 41.2% in CTM, and 35.2% in myelogram. At the L5/S1 disc level, the accuracy of hernia diagnosis by CTM and myelogram was decreased. MRI was useful for the diagnosis and cure of lumbar disc herniation. (author)

  20. Comparison of preoperative neuroradiographic findings and surgical findings in lumbar disc herniation

    International Nuclear Information System (INIS)

    Surgical findings in lumbar disc hernia were compared to pre-operative MRI, CTM and myelogram findings. Ninety-one cases were studied using Love's method. The accuracy of hernia diagnosis in MRI was 59.3%, 41.2% in CTM, and 35.2% in myelogram. At the L5/S1 disc level, the accuracy of hernia diagnosis by CTM and myelogram was decreased. MRI was useful for the diagnosis and cure of lumbar disc herniation. (author)

  1. Thermogravimetric and kinetic methods to date wood finds. First results.

    Science.gov (United States)

    Campanella, Luigi; Favero, Gabriele; Rodante, Fabrizio; Tomassetti, Mauro; Vecchio, Stefano

    2003-11-01

    Fresh (larch and fir, in its white and red varieties) and ancient wood samples (dating respectively to the 13th, 15th and 17th centuries) were subjected to thermogravimetric analysis (TG and DTG). The resulting thermogravimetric data were then used to construct archeometric curves for the wood varieties tested. In a preliminary approach, it was attempted to correlate the onset temperature of the thermogravimetric step corresponding to cellulose decomposition with the age (expressed in centuries) of the samples, although the results obtained were anything but brilliant. More encouraging results were obtained by examining the relationship between wood sample age and the value of the (percent cellulose/percent lignin) ratio computed from the thermogravimetric data. Lastly, a procedure for processing data obtained from the TG curves was applied to a kinetic analysis of the processes that take place when wood samples are subjected to a temperature regime with a constant heating rate, obtaining values for the activation energy of the TG step corresponding to the decomposition of cellulose. Also using these data it was attempted to construct archeometric curves, obtaining results that varied quite significantly according to the wood species tested. PMID:14703859

  2. Benzene exposure: An overview of monitoring methods and their findings

    OpenAIRE

    Weisel, Clifford P

    2010-01-01

    Benzene has been measured throughout the environment and is commonly emitted in several industrial and transportation settings leading to widespread environmental and occupational exposures. Inhalation is the most common exposure route but benzene rapidly penetrates the skin and can contaminant water and food resulting in dermal and ingestion exposures. While less toxic solvents have been substituted for benzene, it still is a component of petroleum products, including gasoline, and is a trac...

  3. Behavioral Couples Therapy for Substance Abuse: Rationale, Methods, and Findings

    OpenAIRE

    Fals-Stewart, William; O’Farrell, Timothy J.; Birchler, Gary R.

    2004-01-01

    Behavioral couples therapy (BCT), a treatment approach for married or cohabiting drug abusers and their partners, attempts to reduce substance abuse directly and through restructuring the dysfunctional couple interactions that frequently help sustain it. In multiple studies with diverse populations, patients who engage in BCT have consistently reported greater reductions in substance use than have patients who receive only individual counseling. Couples receiving BCT also have reported higher...

  4. Videocinematography of the act of swallowing. Indication, method, and findings

    International Nuclear Information System (INIS)

    The purpose of this study was to give an introduction to the radiological evaluation of deglutition. The symptoms leading to videofluoroscopic investigation of swallowing are explained. The examination has to be tailored to the patient's symptoms. Each film scene depicts a characteristic patient position, a particular kind of contrast material and a certain amount. A systematic approach to analyze video films of deglutition and knowledge of the normal and abnormal swallowing functions are mandatory. (orig.)

  5. Research on Interest in Science: Theories, Methods, and Findings

    Science.gov (United States)

    Krapp, Andreas; Prenzel, Manfred

    2011-01-01

    This article presents an overview of interest research and describes the theoretical and methodological background for the assessment of interest in science in large-scale assessments like the "Programme for International Student Assessment" (PISA). The paper starts with a short retrospective on the history of interest, bringing out theoretical…

  6. Theory, Method and Practice of Neuroscientific Findings in Science Education

    Science.gov (United States)

    Liu, Chia-Ju; Chiang, Wen-Wei

    2014-01-01

    This report provides an overview of neuroscience research that is applicable for science educators. It first offers a brief analysis of empirical studies in educational neuroscience literature, followed by six science concept learning constructs based on the whole brain theory: gaining an understanding of brain function; pattern recognition and…

  7. An easy method for finding many very large prime numbers

    OpenAIRE

    Euler, Leonhard

    2005-01-01

    Translated from the Latin original "Facillima methodus plurimos numeros primos praemagnos inveniendi" (1778). E718 in the Enestrom index. If m is a number of the form 4k+1 and is a sum of two relatively prime squares, then it is prime if and only if it is not the sum of two other squares. In this paper Euler wants to generalize this criterion. He looks at when 232aa+1 represents a prime number. He uses his "numeri idonei" (suitable numbers, convenient numbers, idoneal numbers).

  8. Sustainable Development Index in Hong Kong: Approach, Method and Findings

    Science.gov (United States)

    Tso, Geoffrey K. F.; Yau, Kelvin K. W.; Yang, C. Y.

    2011-01-01

    Sustainable development is a priority area of research in many countries and regions nowadays. This paper illustrates how a multi-stakeholders engagement process can be applied to identify and prioritize the local community's concerns and issues regarding sustainable development in Hong Kong. Ten priority areas covering a wide range of community's…

  9. Sustainable Development Index in Hong Kong: Approach, Method and Findings

    Science.gov (United States)

    Tso, Geoffrey K. F.; Yau, Kelvin K. W.; Yang, C. Y.

    2011-01-01

    Sustainable development is a priority area of research in many countries and regions nowadays. This paper illustrates how a multi-stakeholders engagement process can be applied to identify and prioritize the local community's concerns and issues regarding sustainable development in Hong Kong. Ten priority areas covering a wide range of community's…

  10. Radiologic findings of neonatal sepsis

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Sam Soo; Han, Dae Hee; Choi, Guk Myeong; Jung, Hye Won [Seoul National Univ. College of Medicine, Seoul (Korea, Republic of); Yoon, Hye Kyung; Han, Bokyung Kim; Lee, Nam Yong [Sansung Medical Center, Seoul (Korea, Republic of)

    1997-06-01

    To review the simple radiographic and sonographic findings in infants with neonatal sepsis. We retrospectively analyzed simple chest and abdominal radiographs, and brain sonograms in 36 newborn infants (preterm : term=23 :13). With neonatal sepsis diagnosed by blood culture and clinical manifestations. Pulmonary parenchymal infiltrate excluding respiratory distress syndrome and pulmonary edema or atelectasis was found in 22 infants (61%). Paralytic ileus, hepatosplenomegaly, and necrotizing enterocolitis were present in 18(50%), 9(25%), and 1(3%) infants, respectively, while skeletal changes suggesting osteomyelitis were found in three. Brain sonography was performed in 29 infants and in four, abnormalities were seen ; these comprised three germinal matrix hemorrhages and one intraparenchymal hemorrhage. In six patients(17%) radiologic examinations revealed no abnormality. In patients with neonatal sepsis, pulmonary infiltrates and paralytic ileus were common abnormalities. Although these were nonspecific, radiologic findings may be used to supplement clinical and laboratory findings in diagnosing neonatal sepsis and planning its treatment.

  11. Radiologic findings of neonatal sepsis

    International Nuclear Information System (INIS)

    To review the simple radiographic and sonographic findings in infants with neonatal sepsis. We retrospectively analyzed simple chest and abdominal radiographs, and brain sonograms in 36 newborn infants (preterm : term=23 :13). With neonatal sepsis diagnosed by blood culture and clinical manifestations. Pulmonary parenchymal infiltrate excluding respiratory distress syndrome and pulmonary edema or atelectasis was found in 22 infants (61%). Paralytic ileus, hepatosplenomegaly, and necrotizing enterocolitis were present in 18(50%), 9(25%), and 1(3%) infants, respectively, while skeletal changes suggesting osteomyelitis were found in three. Brain sonography was performed in 29 infants and in four, abnormalities were seen ; these comprised three germinal matrix hemorrhages and one intraparenchymal hemorrhage. In six patients(17%) radiologic examinations revealed no abnormality. In patients with neonatal sepsis, pulmonary infiltrates and paralytic ileus were common abnormalities. Although these were nonspecific, radiologic findings may be used to supplement clinical and laboratory findings in diagnosing neonatal sepsis and planning its treatment

  12. Ultrasonographic findings of ovarian cystadenoma

    International Nuclear Information System (INIS)

    The ultrasonographic findings of 49 ovarian cystadenomas were analyzed. The results were as follows. 1. The most common age group was 3rd decade and most patients (83%) belong to active reproductive period. 2. In 80% of serous cystadenoma the size of the tumor was ranged in 6-10 cm in diameter. The large tumors of 16-20 cm in diameter were mostly mucinous cystadenomas. 3. Purely cystic appearance was the most common finding (40%) of serous cystadenoma and thick linear septation with and without solid component was the most common finding (38%) of mucious cystadenoma. 4. Thick linear septation with solid component was not found in serous cystadenoma. 5. Well defined nodular projection was found in 3 cases of serous cystadenoma but not identified in mucinous cystadenoma.

  13. CT findings of the thymus

    International Nuclear Information System (INIS)

    In 14 cases of normal and abnormal thymus proved surgically and histopathologically in korea University Hae Wha Hospital during recent 6 years, the clinical and CT findings were analyzed. 1. Of 14 cases, 2 cases were normal thymus, 5 cases were thymic hyperplasia, 4 cases were benign thymoma, 2 case were malignant thymoma and 1 case was thymic cyst. 2. Of 14 cases, 10 cases were associated with myasthenia gravis, and 7 of these 10 cases were 3rd to 5th decades females. Among 10 cases with myasthenia gravis. 5 cases were thymic hyperplasia, 1 case was benign thymoma, 2 cases were malignant thymoma, and 2 cases were normal thymus. 3. All 5 thymic hyperplasia were associated with myasthenia gravis. CT findings of thymic hyperplasia were normal in 4 cases and increased lobe thickness in 1 case. 4. Of 4 cases of benign thymoma, only 1 case was associated with myasthenia gravis, and all 4 cases were positive findings in CT scan. CT findings of benign thymoma were round or oval soft tissue mass in anterior mediastinum, and 1 case had punctuate calcifications. 5. Of 2 cases of malignant thymoma, all 2 cases were associated with myasthenia gravis and positive findings in CT scan. CT findings of malignant thymoma were anterior mediastinal soft tissue mass with obliteration of the normal fat planes surrounding great vessels. SVC compression, and pleural tumor implants. 6. CT yielded significant diagnostic information of differential diagnosis between thymoma and thymoma hyperplasia in myasthenia gravis patients. Also CT was highly sensitive test in detection of thymoma and determined the extent and invasiveness of thymoma.

  14. Peak finding using biorthogonal wavelets

    International Nuclear Information System (INIS)

    The authors show in this paper how they can find the peaks in the input data if the underlying signal is a sum of Lorentzians. In order to project the data into a space of Lorentzian like functions, they show explicitly the construction of scaling functions which look like Lorentzians. From this construction, they can calculate the biorthogonal filter coefficients for both the analysis and synthesis functions. They then compare their biorthogonal wavelets to the FBI (Federal Bureau of Investigations) wavelets when used for peak finding in noisy data. They will show that in this instance, their filters perform much better than the FBI wavelets

  15. CT findings of tracheobronchial tuberculosis

    International Nuclear Information System (INIS)

    Tracheobronchial tuberculosis is the tuberculous affection of tracheobronchial wall mainly due to direct implantation of infected sputum through airway. When inflammation extends deeply into the bronchial mucosa, causing ulceration and necrosis, healing can occur with fibrosis and result in bronchial stenosis. There have been many reports of simple chest findings and bronchographic findings about tracheobronchial tuberculosis. But there is no report about CT findings of tracheobronchial tuberculosis. We reviewed and analysed CT findings of 15 cases of tracheobronchial tuberculosis which were examined during the period from January 1987 to August 1989. The diagnosis was based on bronchoscopic biopsy (5), positive sputum, AFB (5), or previous antituberculous medication with typical bronchoscopic finding (5). All 15 patients were studied with a GE-9800 scanner after injection of intravenous contrast media injection. The results were as follows. 1. Of the 15 cases, 13 cases were female and 2 cases were male. Most patients were female in their twenties or thirties. 2. The CT findings of endobronchial lesion are luminal narrowing in 15, luminal obstruction in 6, increased wall thickness in 9, wall enhancement in 2, surrounding fat plane obliteration in 7. 3. CT and bronchoscopy, equally detected bronchial lesions in 8 cases. CT was superior in 4 cases and bronchoscopy was superior in 2 cases. 4. The most frequently affected site was left main bronchus (8), followed by trachea (4), right main bronchus (4), right bronchus intermedius (4), RUL bronchus (3), LUL bronchus (3), LLL bronchus (3), RML bronchus (1), RLL bronchus (1). 5. There were 8 cases of surrounding lymphadenopathy and 7 cases of surrounding calcified lymph node. Mainly right para tracheal and tracheobronchial lymph node enlargement were observed. 6. The findings of parenchymal lesion were ill-defined nodule in 10, ateletasis in 9, bronchiectasis in 8, emphysema in 7, consolidation in 5 and cavity in 2. No parenchymal lesion observed in 1 case. Tracheobronchial stenosis, involving concentrically and long segment, in a relatively young female patient without visible mass around the stenotic segment are the typical findings of tracheobronchial tuberculosis

  16. Fucosidosis: MRI and MRS findings

    International Nuclear Information System (INIS)

    Fucosidosis is a rare, autosomal recessive lysosomal storage disease in which fucose-containing glycolipids, glycoproteins, and oligosaccharides accumulate in tissues as a consequence of ?-l-fucosidase enzyme deficiency. We present the MR imaging findings of diffuse white-matter hyperintensity and pallidal curvilinear streak hyperintensity in a 6-year-old Caucasian girl with a diagnosis of fucosidosis based on cDNA isolated from skin fibroblasts. This report also includes the MRS findings of a decreased N-acetylaspartate/choline ratio together with an abnormal peak at 3.8 ppm which expand the knowledge of the neuroradiological spectrum of this rare disease. (orig.)

  17. Wiring systems and fault finding

    CERN Document Server

    Scaddan, Brian

    1905-01-01

    This book deals with an area of practice which many students and non-electricians find particularly challenging. It explains how to interpret circuit diagrams, wiring systems and the principles and practice of testing and fault diagnosis. It will give the reader confidence to understand the principles of testing and to apply this knowledge to fault finding in electrical circuits.It is a handy reference for anybody who needs to be able to trace faults in circuits, whether in domestic, commercial or industrial settings. It will be a time-saver for all electricians, plumbers, heating engineers, t

  18. Fucosidosis: MRI and MRS findings

    Energy Technology Data Exchange (ETDEWEB)

    Oner, Ali Y.; Akpek, Sergin [Gazi University School of Medicine, Department of Radiology, Ankara (Turkey); Cansu, Ali; Serdaroglu, Ayse [Gazi University School of Medicine, Department of Paediatrics, Ankara (Turkey)

    2007-10-15

    Fucosidosis is a rare, autosomal recessive lysosomal storage disease in which fucose-containing glycolipids, glycoproteins, and oligosaccharides accumulate in tissues as a consequence of {alpha}-l-fucosidase enzyme deficiency. We present the MR imaging findings of diffuse white-matter hyperintensity and pallidal curvilinear streak hyperintensity in a 6-year-old Caucasian girl with a diagnosis of fucosidosis based on cDNA isolated from skin fibroblasts. This report also includes the MRS findings of a decreased N-acetylaspartate/choline ratio together with an abnormal peak at 3.8 ppm which expand the knowledge of the neuroradiological spectrum of this rare disease. (orig.)

  19. Nonpalpable breast cancer : mammographic and clinical findings

    International Nuclear Information System (INIS)

    To evaluate the mammographic and clinical findings of nonpalpable breast cancer. Materials and Methods : In 28 of 607 breast cancer patients examined between January 1994 and April 1997, lesions were nonpalpable. We retrospectively analyzed the mammographic, clinical and pathologic features of 25 patients (28 lesions) whose mammograms we obtained. Results : Among these 25 patients (28 lesions) screening was abnormal in 22; other symptoms were bloody nipple discharge(n=4), and nipple eczema(n=2). The patients were 34-62 (mean 52)years old. Invasive ductal carcinoma(n=13), DCIS(ductal carcinoma in situ, n-12), Paget's disease (n=2), and LCIS(lobular carcinoma in situ, n=1) were found during surgery. Six of 28 lesions(21%) showed evidence of axillary nodal metastasis;the majority arose from the upper outer quadrant of the breast (n=21). The mammographic findings were mass (50%), (and mass with microcalcification, 11%); microcalcification(29%); asymmetrical density(14%); and normal (7%). According to the mammographic density of breast parenchyma, the major finding in the low density group(N1+P1) was mass(9/9), and in the high density group(P2+DY) was microcalcification (12/19). Conclusion : The most common mammographic findings of nonpalpable breast cancer were mass (50%) and microcalcification(29%). Its features varied according to the mammographic density of breast parenchyma;mass was the main finding in the low density group and microcalcification in the high density group

  20. Skin Findings in Renal Transplantation Patients

    Directory of Open Access Journals (Sweden)

    Demet Kartal

    2013-03-01

    Full Text Available Objective: It was aimed to identify skin findings those were seen in patients who undergone renal transplantation. Methods: Patients who have been followed in Erciyes University Nephrology Hospital renal transplantation outpatient clinic were included in the study. They were evaluated for dermatologic findings during routine controls. Age, gender, transplantation date, identity of organ donor, history of medications, dermatological history and dermatological findings during examination were recorded. Biopsy was performed when needed. Results: In total 94 patients, 25 female (26.6% and 69 male (73.4%, were recruited to the study. Mean age was 36±10 years. The most frequent skin finding was drug-related acne (n=20. Most common infectious disease was verruca (n=17. There were viral disease other than verruca such as herpes zoster (n=3, superficial mycosis such as onychomycosis (n=5, tinea versicolor, tinea pedis and bacterial skin disease (n=2, and paronychia (n=1 and pre-malign lesions such as actinic cheilitis and bowenoid papulosis. Besides these, stria (n=3, kserosis (n=2, cornu cutaneum, café-au-lait spots, sebaceous hyperplasia and seborrheic dermatitis, skin tag, hypertrichosis, unguis incarinatus and calcinosis were other skin findings those were seen. No malign skin lesion was observed in any of patients. Conclusion: Miscellaneous skin lesions should develop in patients those undergone renal transplantation due to long-term utilization of various immunosuppressive drugs.

  1. Intramammary incidental findings on staging computer tomography

    Energy Technology Data Exchange (ETDEWEB)

    Surov, Alexey, E-mail: alex.surow@medizin.uni-halle.de [Department of Radiology, Martin-Luther-University Halle-Wittenberg, Ernst-Grubestr. 40, 06097 Halle (Germany); Fiedler, Eckhard [Department of Dermatology, Martin-Luther-University Halle-Wittenberg, Ernst-Grubestr. 40, 06097 Halle (Germany); Wienke, Andreas [Department of Medical Statistics, Martin-Luther-University Halle-Wittenberg, Ernst-Grubestr. 40, 06097 Halle (Germany); Holzhausen, Hans-Jürgen [Department of Pathology, Martin-Luther-University Halle-Wittenberg, Ernst-Grubestr. 40, 06097 Halle (Germany); Spielmann, Rolf-Peter; Behrmann, Curd [Department of Radiology, Martin-Luther-University Halle-Wittenberg, Ernst-Grubestr. 40, 06097 Halle (Germany)

    2012-09-15

    Purpose: Incidental findings are a common feature in computer tomographic examinations of the chest. Breast incidentalomas, however, were described only sporadically. The purpose of this study was to evaluate retrospectively incidental breast findings and to compare radiological features of benign and malignant breast lesions. Materials and methods: From January 2006 to December 2010 a total of 8105 computer tomographic examinations were performed at our institution. In 89 patients incidental breast lesions were diagnosed. 64 of the identified patients were referred for further clinical, radiological, and hystopathological examination. All patients were female with a median age of 62 years, range 39–82 years. Results: A total of 98 breast lesions were identified in the 64 patients. The mean size was 12.0 ± 8.0 mm. Primary breast carcinoma was identified in 9, breast metastases in 27, and benign findings in 28 patients. Malignant lesions demonstrated more often marked enhancement and showed a higher density compared with benign lesions. Benign findings were more often lobular in shape and had spiculated margins. Most of the breast metastases were round or oval in shape with circumscribed margins and marked homogenous enhancement. There was no significant difference between the breast cancer and benign findings groups in the characteristics of the lesions. Conclusion: The breast is a very important region and should be carefully evaluate on chest CT. There are no certain radiological criteria to differentiate between malignant and benign breast lesions on CT. Therefore all breast incidentalomas should be evaluated by further radiological/histological investigations.

  2. Comparative study between the proposed shape independent clustering method and the conventional methods (K-means and the other

    Directory of Open Access Journals (Sweden)

    Kohei Arai

    2013-07-01

    Full Text Available Cluster analysis aims at identifying groups of similar objects and, therefore helps to discover distribution of patterns and interesting correlations in the data sets. In this paper, we propose to provide a consistent partitioning of a dataset which allows identifying any shape of cluster patterns in case of numerical clustering, convex or non-convex. The method is based on layered structure representation that be obtained from measurement distance and angle of numerical data to the centroid data and based on the iterative clustering construction utilizing a nearest neighbor distance between clusters to merge. Encourage result show the effectiveness of the proposed technique.

  3. Computed tomographic findings of benign retroperitoneal tumors

    International Nuclear Information System (INIS)

    We have reviewed the computed tomographic (CT) findings of 8 cases of benign retroperitoneal tumors with histological proof. Two teratomas, two schwannomas, and one each of epidermoid cyst, simple cyst, bronchogenic cyst, and cystic lymphangioma were included. The most common CT appearance of these tumors was the solitary, round, well-demarcated, relatively low density mass. Capsule or calcification was demonstrated in some. CT is a highly valuable non-invasive examination method for a diagnosis of a benign retroperitoneal tumor. (author)

  4. Finding important sites in protein sequences

    OpenAIRE

    Bickel, Peter J.; Kechris, Katherina J; Spector, Philip C.; Wedemayer, Gary J.; Glazer, Alexander N.

    2002-01-01

    By using sequence information from an aligned protein family, a procedure is exhibited for finding sites that may be functionally or structurally critical to the protein. Features based on sequence conservation within subfamilies in the alignment and associations between sites are used to select the sites. The sites are subject to statistical evaluation correcting for phylogenetic bias in the collection of sequences. This method is applied to two families: the phycobiliproteins, light-harvest...

  5. Intrauterine Devices Penetrated and Migrated: CT Findings

    International Nuclear Information System (INIS)

    Intrauterine devices have been used for over 40 years, and they constitute the most widely accepted method of contraception among women because of the low rates of complications and low cost. Although uncommon, with the growing use of multidetector CT penetrated and migrated intrauterine devices have become a more common incidental finding. In some cases, intrauterine devices migrate to adjacent viscera, in particular the bladder and bowel and may give rise to symptoms. Consequently tomographic localization and characterization are essential for treatment planning.

  6. Gene finding in the chicken genome

    OpenAIRE

    Antonarakis Stylianos E; Rogers Jane; Wyss Carine; Shteynberg David D; Huckle Elizabeth J; Parra Genis; Flicek Paul; Camara Francisco; Bye Jacqueline M; Castelo Robert; Reymond Alexandre; Eyras Eduardo; Birney Ewan; Guigo Roderic; Brent Michael R

    2005-01-01

    Abstract Background Despite the continuous production of genome sequence for a number of organisms, reliable, comprehensive, and cost effective gene prediction remains problematic. This is particularly true for genomes for which there is not a large collection of known gene sequences, such as the recently published chicken genome. We used the chicken sequence to test comparative and homology-based gene-finding methods followed by experimental validation as an effective genome annotation metho...

  7. Imaging Finding in 222 Patients with Vestibular

    OpenAIRE

    A. Zahiri

    2008-01-01

    Background/Objective: Vestibular Schwannoma is the most common cranial schwannoma with gradually produce sensorineural deafness. In this study we observed the effect of Gamma Knife therapy for control of this type of schwannoma."nPatients and Methods: We observed imaging findings of 250 patients with vestibular schwannoma from September 2003 to October 2007. We performed the Gamma Knife with C model (Elekta Company) for the treatment and control of the tumor."nResults: The minimum a...

  8. Folding and Finding RNA Secondary Structure

    OpenAIRE

    Mathews, David H.; Moss, Walter N.; TURNER, DOUGLAS H.

    2010-01-01

    Optimal exploitation of the expanding database of sequences requires rapid finding and folding of RNAs. Methods are reviewed that automate folding and discovery of RNAs with algorithms that couple thermodynamics with chemical mapping, NMR, and/or sequence comparison. New functional noncoding RNAs in genome sequences can be found by combining sequence comparison with the assumption that functional noncoding RNAs will have more favorable folding free energies than other RNAs. When a new RNA is ...

  9. Cardiac Findings in Congenital Nephrotic Syndrome

    OpenAIRE

    Shamsi Ghaffari1; Samad Ghaffari; Majid Malaki

    2011-01-01

    Introduction: Congenital nephrotic syndrome is a severe debilitating problem associated with extra renal manifestation such as diverse cardiac findings. Methods: During four years 6 cases diagnosed as congenital nephritic syndrome in base of definitive criteria their documents reviewed and echocardiographic evaluation has been done for all with or with-out cardiac sign or symptoms, results gathered and expressed as incidence. Results: All cases have some grades of structural or functional def...

  10. Finding Flow Experience in Music Activity

    OpenAIRE

    Dewi Sartika; Saraya Ikramina Husna

    2014-01-01

    This research is aim to describe how one finding flow experience in his music activity, experiencing flow and feeling the impact of flow experience to his music career and life. The research method used is qualitative, intrinsic study case. The participants are two famous jazz musicians in Bandung, West Java, Indonesia. Data collecting used are in-depth interview, participant observation and document. The result shows that participant who has environment support especially from his music teac...

  11. CT findings of pulmonary hypertension

    International Nuclear Information System (INIS)

    For the treatment for pulmonary hypertension (PH), the differential diagnosis of its causal diseases is essential. To determine whether X-ray CT is useful for differentiating PH, we reviewed CT findings of 53 patients (18 men and 35 women, mean age of 44.9) given a diagnosis of PH, consisting of 25 with primary pulmonary hypertension (PPH), 18 with chronic pulmonary embolism (cPE), 6 with Eisenmenger syndrome, 5 cases of collagen diseases, 2 of acute PE, and 1 of cor pulmonale. The intrapulmonary distribution of CT findings (ground glass opacity [GGO], mosaic attenuation, striation and/or infiltration, and interlobular septal thickening) were reviewed and scored on a 4-point scale (grade 0: no findings, 1: involving one third of the lung, 2: involving one-two thirds, and 3: diffuse distribution) by two radiologists who reached a consensus. PPH showed preferentially diffuse distribution of GGO as compared with cPE (p<0.05). However, there was no apparent relationship between the pulmonary vascular resistance and the distribution of GGO in PPH cases. The mosaic attenuation pattern was more frequent in cPE (43%) than PPH (12%; p<0.05). Striation and/or infiltration was observed in 36% of cPE, but only 4% of PPH. Interlobular septal thickening was seen in 16% of PPH, and 0% in cPE. Evaluation of CT findings is useful to differentiate PH. (author)

  12. US findings of tubal pregnancy

    International Nuclear Information System (INIS)

    Early diagnosis of ruptured and unruptured tubal pregnancy became more accurate with the introduction of transvaginal sonographic equipment. The management principle of tubal pregnancy might be changed according to the sonographic findings. The purposes of this study were to define the sonographic findings of tubal pregnancy and to determine whether it is possible to differentiate the unruptured tubal pregnancies from the ruptured ones depending on the sonographic findings. The authors investigated the sonographic findings of the surgically confirmed 25 tubal pregnancy patients. There were 22(88%) unruptured and 3(12%) ruptured tubal pregnancies. Unruptured pregnancies showed tubal ring in 8, well defined hematosalpinx in 11, and poorly defined hematosalpinxin 2 patients. Ruptured pregnancies showed tubal sac with irregular margin in 2, and ill-defined hematosalpinx in one patient. In summary, well marginated tubal ring and hematosalpinx suggested unruptured tubal pregnancy, while tubal sac with irregular margin suggested ruptured pregnancy. However, it was difficult to differentiate the unruptured tubal pregnancy from the ruptured one when hematosalpinx was ill-defined

  13. MRI findings in cranial eumycetoma

    Directory of Open Access Journals (Sweden)

    Munawwar Ahmed

    2011-01-01

    Full Text Available Cranial eumycetoma (CE due to direct inoculation of Madurella grisea into the scalp is extremely rare. We describe a case of CE caused by direct inoculation of M. grisea with the characteristic MRI findings of the "dot-in-circle" sign and a conglomeration of multiple, extremely hypointense "dots."

  14. Writing audit findings: Be reasonable!

    Energy Technology Data Exchange (ETDEWEB)

    Girvin, N.W.

    1992-05-01

    A customary approach to auditing and reporting deficiencies is to keep a running list of those that are found, evaluate the severity of each, and based on the evidence, document findings or observations or concerns in an audit report. The report is issued and the auditee is normally requested to address ``root cause`` as part of their corrective action. This paper describes a ``root problems`` approach to documenting audit findings that is designed not only to put the QA auditor in a more favorable light, but to more effectively enable the auditee to identify root cause and meaningful corrective action. The positive results of this approach are considerable. You will have fewer findings but those you do have will be substantial. You will cite requirements that sound reasonable and make arguments difficult. If some of the supporting deficiencies (examples) prove to be incorrect, you will still have ample support for the original finding. You will be seen as reasonable individual who can help lead the auditee towards identification of root cause without taking away part of the responsibility. You even have a fair chance of fostering a sense of commitment to quality improvement on the auditee`s part. This in itself, is its own reward.

  15. Writing audit findings: Be reasonable

    Energy Technology Data Exchange (ETDEWEB)

    Girvin, N.W.

    1992-05-01

    A customary approach to auditing and reporting deficiencies is to keep a running list of those that are found, evaluate the severity of each, and based on the evidence, document findings or observations or concerns in an audit report. The report is issued and the auditee is normally requested to address root cause'' as part of their corrective action. This paper describes a root problems'' approach to documenting audit findings that is designed not only to put the QA auditor in a more favorable light, but to more effectively enable the auditee to identify root cause and meaningful corrective action. The positive results of this approach are considerable. You will have fewer findings but those you do have will be substantial. You will cite requirements that sound reasonable and make arguments difficult. If some of the supporting deficiencies (examples) prove to be incorrect, you will still have ample support for the original finding. You will be seen as reasonable individual who can help lead the auditee towards identification of root cause without taking away part of the responsibility. You even have a fair chance of fostering a sense of commitment to quality improvement on the auditee's part. This in itself, is its own reward.

  16. Transfusional hemosiderosis; correlation of MR findings with clinical findings

    International Nuclear Information System (INIS)

    Parenchymal iron deposition occurs in hemochromatosis, while iron is deposited in reticuloendothelial cells after blood transfusions(Hemosiderosis). We studied correlation between MR finding and clinical findings(serum ferritin, TSI, LFT, disease duration) of hemosiderosis. 12 patients with chronic renal failure and one patient with aplastic anemia, who have received multiple transfusion, were performed MRI with a 2.0 Tesla unit. In all of 13 patients(17 cases), the liver revealed low signal intensity equal to background noise. In 4 of 17 cases whose serum ferritin level was below 1000 ng/ml, pancreas, gastric wall, adrenal gland were involved in 1 case. In 4 cases with serum ferritin level between 1000 and 1500, pancreas was involved in 2 cases, and other organ was involved in 1 case. In 9 cases with serum ferritin level above 1500ng/ml, pancreas was involved in 9 cases, and other origin 4 cases. The MR findings are well correlated with serum ferritin level whereas the TSI, LFT, disease duration are not correlated with involved organ on MR

  17. Transfusional hemosiderosis; correlation of MR findings with clinical findings

    Energy Technology Data Exchange (ETDEWEB)

    Park, Mi Ok; Kim, Ju Heon; Jeon, Woo Jin; Lee, Sung Moon; Kim, Hong; Suh, Soo Jhi [School of Medicine, Keimyung University, Taegu (Korea, Republic of)

    1994-08-15

    Parenchymal iron deposition occurs in hemochromatosis, while iron is deposited in reticuloendothelial cells after blood transfusions(Hemosiderosis). We studied correlation between MR finding and clinical findings(serum ferritin, TSI, LFT, disease duration) of hemosiderosis. 12 patients with chronic renal failure and one patient with aplastic anemia, who have received multiple transfusion, were performed MRI with a 2.0 Tesla unit. In all of 13 patients(17 cases), the liver revealed low signal intensity equal to background noise. In 4 of 17 cases whose serum ferritin level was below 1000 ng/ml, pancreas, gastric wall, adrenal gland were involved in 1 case. In 4 cases with serum ferritin level between 1000 and 1500, pancreas was involved in 2 cases, and other organ was involved in 1 case. In 9 cases with serum ferritin level above 1500ng/ml, pancreas was involved in 9 cases, and other origin 4 cases. The MR findings are well correlated with serum ferritin level whereas the TSI, LFT, disease duration are not correlated with involved organ on MR.

  18. Symmetric imaging findings in neuroradiology

    International Nuclear Information System (INIS)

    Full text: Learning objectives: to make a list of diseases and syndromes which manifest as bilateral symmetric findings on computed tomography and magnetic resonance imaging; to discuss the clinical and radiological differential diagnosis for these diseases; to explain which of these conditions necessitates urgent therapy and when additional studies and laboratory can precise diagnosis. There is symmetry in human body and quite often we compare the affected side to the normal one but in neuroradiology we might have bilateral findings which affected pair structures or corresponding anatomic areas. It is very rare when clinical data prompt diagnosis. Usually clinicians suspect such an involvement but Ct and MRI can reveal symmetric changes and are one of the leading diagnostic tool. The most common location of bilateral findings is basal ganglia and thalamus. There are a number of diseases affecting these structures symmetrically: metabolic and systemic diseases, intoxication, neurodegeneration and vascular conditions, toxoplasmosis, tumors and some infections. Malformations of cortical development and especially bilateral perisylvian polymicrogyria requires not only exact report on the most affected parts but in some cases genetic tests or combination with other clinical symptoms. In the case of herpes simplex encephalitis bilateral temporal involvement is common and this finding very often prompt therapy even before laboratory results. Posterior reversible encephalopathy syndrome (PReS) and some forms of hypoxic ischemic encephalopathy can lead to symmetric changes. In these acute conditions MR plays a crucial role not only in diagnosis but also in monitoring of the therapeutic effect. Patients with neurofibromatosis type 1 or type 2 can demonstrate bilateral optic glioma combined with spinal neurofibroma and bilateral acoustic schwanoma respectively. Mirror-image aneurysm affecting both internal carotid or middle cerebral arteries is an example of symmetry in pathology of vessels. In posterior cranial fossa the findings can involve dentate nuclei as in the cases of infections, metabolic diseases or intoxication with metronidazole. In the latter case the changes are reversible. Postinfectious cerebellitis is another cause for symmetric changes which are localized in white matter. Spinal cord might be symmetrically affected in the case of ischemia, vitamin B12 and vitamin e deficiency, AIDS, cooper deficiency, Friedreich’s ataxia. Symmetric findings in neuroimaging have their specific Ct and MRI characteristics but to narrow the differential diagnosis it is necessary to look for another brain areas involvement or to combine findings with clinics and laboratory data as well as to use MR diffusion, MR spectroscopy, MR angiography or MR venography in the selected case

  19. Ischemic colitis: computed tomography findings

    International Nuclear Information System (INIS)

    To describes the findings computed tomography (CT) findings in 28 patients with ischemic colitis, analyzing their prognostic value. A retrospective study was carried out in 28 patients with a confirmed diagnosis of ischemic colitis. We reviewed the clinical history and CT findings. In the CT images, we assessed the site of the affected segment, length, thickness, appearance of the external end of the colonic wall, presence of ascites, air in the intestinal wall or portal vein an pattern of attenuation following the injection of intravenous contrast. The statistical analysis was done using chi-squared test and ANOVA. Twenty-four patients (86%) presented left colon involvement and in 4 (14%), right colon was affected. None of the patients had pancolonic involvement. The length of the affected segments ranged between 7 and 35 cm (mean: 20 cm). the mean thickness was 8 mm. The ischemic segment presented a smooch contour in 22 patients (79%) and rough in 6. After injection of intravenous contrast, concentric rings of uptake were observed in 12 patients and the absence of layers in another 16. Eight patients (31%) presented ascites. There was only one case of air in portal vein, intramural air or pneumopritoneum. We found no statistically significant association between the signs assessed in CT and disease course. Although the CT findings are nonspecific, they can aid in the diagnosis of ischemic colitis within the proper clinical context, especially in older patients with predisposing factors and a segmental distribution of the disease. The CT findings are of no diagnostic value. (Author) 24 refs

  20. Computer Vision Tools for Finding Images and Video Sequences.

    Science.gov (United States)

    Forsyth, D. A.

    1999-01-01

    Computer vision offers a variety of techniques for searching for pictures in large collections of images. Appearance methods compare images based on the overall content of the image using certain criteria. Finding methods concentrate on matching subparts of images, defined in a variety of ways, in hope of finding particular objects. These ideas…