WorldWideScience

Sample records for centroid finding method

  1. 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.)

  2. An Integrated Centroid Finding and Particle Overlap Decomposition Algorithm for Stereo Imaging Velocimetry

    Science.gov (United States)

    McDowell, Mark

    2004-01-01

    An integrated algorithm for decomposing overlapping particle images (multi-particle objects) along with determining each object s constituent particle centroid(s) has been developed using image analysis techniques. The centroid finding algorithm uses a modified eight-direction search method for finding the perimeter of any enclosed object. The centroid is calculated using the intensity-weighted center of mass of the object. The overlap decomposition algorithm further analyzes the object data and breaks it down into its constituent particle centroid(s). This is accomplished with an artificial neural network, feature based technique and provides an efficient way of decomposing overlapping particles. Combining the centroid finding and overlap decomposition routines into a single algorithm allows us to accurately predict the error associated with finding the centroid(s) of particles in our experiments. This algorithm has been tested using real, simulated, and synthetic data and the results are presented and discussed.

  3. Immune centroids oversampling method for binary classification.

    Science.gov (United States)

    Ai, Xusheng; Wu, Jian; Sheng, Victor S; Zhao, Pengpeng; Cui, Zhiming

    2015-01-01

    To improve the classification performance of imbalanced learning, a novel oversampling method, immune centroids oversampling technique (ICOTE) based on an immune network, is proposed. ICOTE generates a set of immune centroids to broaden the decision regions of the minority class space. The representative immune centroids are regarded as synthetic examples in order to resolve the imbalance problem. We utilize an artificial immune network to generate synthetic examples on clusters with high data densities, which can address the problem of synthetic minority oversampling technique (SMOTE), which lacks reflection on groups of training examples. Meanwhile, we further improve the performance of ICOTE via integrating ENN with ICOTE, that is, ICOTE + ENN. ENN disposes the majority class examples that invade the minority class space, so ICOTE + ENN favors the separation of both classes. Our comprehensive experimental results show that two proposed oversampling methods can achieve better performance than the renowned resampling methods. PMID:25834570

  4. Expand the measurement range of a critical angle refractometer by a centroid method for transparent fluids

    Science.gov (United States)

    Ye, Junwei; Yang, Kecheng; Liu, Hao; Dai, Jie; Guo, Wenping; Li, Wei; Xia, Min

    2015-01-01

    A simple approach to expand the measurement range of a critical angle refractometer (CAR) is demonstrated. Our method is based on measuring the centroid point of the angular reflective ratio of the CAR. According to the Snell's reflective law, the CAR with a divergent beam source has a limited measurement range. When the refractive index (RI) is higher than the upper limit, the reflective ratio curve is gradual changing without cutoff edge between the total internal reflection (TIR) and non-TIR. We find that the centroid point of the gradual changing curve is associated with the RI value of a liquid. Theorectical analysis and experimental results on sugar solutions with RI that varying from 1.359 to 1.3766 show that this method is effective and accurate to expand the measurement range.

  5. 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.

  6. 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.

  7. Star sub-pixel centroid calculation based on multi-step minimum energy difference method

    Science.gov (United States)

    Wang, Duo; Han, YanLi; Sun, Tengfei

    2013-09-01

    The star's centroid plays a vital role in celestial navigation, star images which be gotten during daytime, due to the strong sky background, have a low SNR, and the star objectives are nearly submerged in the background, takes a great trouble to the centroid localization. Traditional methods, such as a moment method, weighted centroid calculation method is simple but has a big error, especially in the condition of a low SNR. Gaussian method has a high positioning accuracy, but the computational complexity. Analysis of the energy distribution in star image, a location method for star target centroids based on multi-step minimum energy difference is proposed. This method uses the linear superposition to narrow the centroid area, in the certain narrow area uses a certain number of interpolation to pixels for the pixels' segmentation, and then using the symmetry of the stellar energy distribution, tentatively to get the centroid position: assume that the current pixel is the star centroid position, and then calculates and gets the difference of the sum of the energy which in the symmetric direction(in this paper we take the two directions of transverse and longitudinal) and the equal step length(which can be decided through different conditions, the paper takes 9 as the step length) of the current pixel, and obtain the centroid position in this direction when the minimum difference appears, and so do the other directions, then the validation comparison of simulated star images, and compare with several traditional methods, experiments shows that the positioning accuracy of the method up to 0.001 pixel, has good effect to calculate the centroid of low SNR conditions; at the same time, uses this method on a star map which got at the fixed observation site during daytime in near-infrared band, compare the results of the paper's method with the position messages which were known of the star, it shows that :the multi-step minimum energy difference method achieves a better effect.

  8. The efficiency of the centroid method compared to a simple average

    DEFF Research Database (Denmark)

    Eskildsen, Jacob Kjær; Kristensen, Kai

    Based on empirical data as well as a simulation study this paper gives recommendations with respect to situations wheere a simple avarage of the manifest indicators can be used as a close proxy for the centroid method and when it cannot.

  9. Shack-Hartmann centroid detection method based on high dynamic range imaging and normalization techniques

    OpenAIRE

    Quiroga Mellado, Juan Antonio; Vargas, Javier; González Fernández, Luis M.; Belenguer Dávila, Tomás

    2010-01-01

    In the optical quality measuring process of an optical system, including diamond-turning components, the use of a laser light source can produce an undesirable speckle effect in a Shack-Hartmann (SH) CCD sensor. This speckle noise can deteriorate the precision and accuracy of the wavefront sensor measurement. Here we present a SH centroid detection method founded on computer-based techniques and capable of measurement in the presence of strong speckle noise. The method extends the dynamic ran...

  10. 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.

  11. Performance evaluation of the spectral centroid downshift method for attenuation estimation.

    Science.gov (United States)

    Samimi, Kayvan; Varghese, Tomy

    2015-05-01

    Estimation of frequency-dependent ultrasonic attenuation is an important aspect of tissue characterization. Along with other acoustic parameters studied in quantitative ultrasound, the attenuation coefficient can be used to differentiate normal and pathological tissue. The spectral centroid downshift (CDS) method is one the most common frequencydomain approaches applied to this problem. In this study, a statistical analysis of this method's performance was carried out based on a parametric model of the signal power spectrum in the presence of electronic noise. The parametric model used for the power spectrum of received RF data assumes a Gaussian spectral profile for the transmit pulse, and incorporates effects of attenuation, windowing, and electronic noise. Spectral moments were calculated and used to estimate second-order centroid statistics. A theoretical expression for the variance of a maximum likelihood estimator of attenuation coefficient was derived in terms of the centroid statistics and other model parameters, such as transmit pulse center frequency and bandwidth, RF data window length, SNR, and number of regression points. Theoretically predicted estimation variances were compared with experimentally estimated variances on RF data sets from both computer-simulated and physical tissue-mimicking phantoms. Scan parameter ranges for this study were electronic SNR from 10 to 70 dB, transmit pulse standard deviation from 0.5 to 4.1 MHz, transmit pulse center frequency from 2 to 8 MHz, and data window length from 3 to 17 mm. Acceptable agreement was observed between theoretical predictions and experimentally estimated values with differences smaller than 0.05 dB/cm/MHz across the parameter ranges investigated. This model helps predict the best attenuation estimation variance achievable with the CDS method, in terms of said scan parameters. PMID:25965681

  12. A fast method for computing the centroid of a type-2 fuzzy set.

    Science.gov (United States)

    Wu, Hsin-Jung; Su, Yao-Lung; Lee, Shie-Jue

    2012-06-01

    Type reduction does the work of computing the centroid of a type-2 fuzzy set. The result is a type-1 fuzzy set from which a corresponding crisp number can then be obtained through defuzzification. Type reduction is one of the major operations involved in type-2 fuzzy inference. Therefore, making type reduction efficient is a significant task in the application of type-2 fuzzy systems. Liu introduced a horizontal slice representation, called the ?-plane representation, and proposed a type-reduction method for a type-2 fuzzy set. By exploring some useful properties of the ?-plane representation and of the type reduction for interval type-2 fuzzy sets, a fast method is developed for computing the centroid of a type-2 fuzzy set. The number of computations and comparisons involved is greatly reduced. Convergence in each iteration can then speed up, and type reduction can be done much more efficiently. The effectiveness of the proposed method is analyzed mathematically and demonstrated by experimental results. PMID:22180511

  13. 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.

  14. 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.

  15. 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.

  16. 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...

  17. The Gibbs Centroid Sampler

    OpenAIRE

    William A. Thompson; Newberg, Lee A; Conlan, Sean; MCCUE, LEE ANN; Lawrence, Charles E

    2007-01-01

    The Gibbs Centroid Sampler is a software package designed for locating conserved elements in biopolymer sequences. The Gibbs Centroid Sampler reports a centroid alignment, i.e. an alignment that has the minimum total distance to the set of samples chosen from the a posteriori probability distribution of transcription factor binding-site alignments. In so doing, it garners information from the full ensemble of solutions, rather than only the single most probable point that is the target of man...

  18. 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.

  19. Geogebra: Calculation of Centroid

    Directory of Open Access Journals (Sweden)

    Qamil Kllogjeri

    2012-09-01

    Full Text Available Our paper is result of the research done in a special direction for solving problems of physics by using GeoGebra programme: calculation of centroid. Lots of simulations of physical phenomena from the class of Mechanics can be performed and computational problems can be solved with GeoGebra. GeoGebra offers many commands and one of them is the command “centroid” to calculate the coordinates of the centroid of a polygon but, we have created a new tool to calculate the coordinates of the centroid of a plane region bounded by curves. Our work is part of the passionate work of many GeoGebra users which will result with a very rich fund of GeoGebra virtual tools, examples and experiences that will be worldwidely available for many teachers and practioners.

  20. 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.

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

    International Nuclear Information System (INIS)

    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 LaBr3(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 40keV?152Eu ?-ray source. Due to reduction and cancellation of many possible systematic errors, the lifetime determination limit of the method 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

  2. A quantum generalization of intrinsic reaction coordinate using path integral centroid coordinates.

    Science.gov (United States)

    Shiga, Motoyuki; Fujisaki, Hiroshi

    2012-05-14

    We propose a generalization of the intrinsic reaction coordinate (IRC) for quantum many-body systems described in terms of the mass-weighted ring polymer centroids in the imaginary-time path integral theory. This novel kind of reaction coordinate, which may be called the "centroid IRC," corresponds to the minimum free energy path connecting reactant and product states with a least amount of reversible work applied to the center of masses of the quantum nuclei, i.e., the centroids. We provide a numerical procedure to obtain the centroid IRC based on first principles by combining ab initio path integral simulation with the string method. This approach is applied to NH(3) molecule and N(2)H(5) (-) ion as well as their deuterated isotopomers to study the importance of nuclear quantum effects in the intramolecular and intermolecular proton transfer reactions. We find that, in the intramolecular proton transfer (inversion) of NH(3), the free energy barrier for the centroid variables decreases with an amount of about 20% compared to the classical one at the room temperature. In the intermolecular proton transfer of N(2)H(5) (-), the centroid IRC is largely deviated from the "classical" IRC, and the free energy barrier is reduced by the quantum effects even more drastically. PMID:22583273

  3. 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.

  4. 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.

  5. Micro-pixel accuracy centroid displacement estimation and detector calibration

    CERN Document Server

    Zhai, Chengxing; Goullioud, Renaud; Nemati, Bijan

    2011-01-01

    Precise centroid estimation plays a critical role in accurate astrometry using telescope images. Conventional centroid estimation fits a template point spread function (PSF) to the image data. Because the PSF is typically not known to high accuracy due to wavefront aberrations and uncertainties in optical system, a simple Gaussian function is commonly used. PSF knowledge error leads to systematic errors in the conventional centroid estimation. In this paper, we present an accurate centroid estimation algorithm by reconstructing the PSF from well sampled (above Nyquist frequency) pixelated images. In the limit of an ideal focal plane array whose pixels have identical response function (no inter-pixel variation), this method can estimate centroid displacement between two 32$\\times$32 images to sub-micropixel accuracy. Inter-pixel response variations exist in real detectors, {\\it e.g.}~CCDs, which we can calibrate by measuring the pixel response of each pixel in Fourier space. The Fourier transforms of the inter...

  6. STATISTICS OF CENTROIDS OF VELOCITY

    OpenAIRE

    A. Esquivel; Lazarian, 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 d...

  7. Variable centroid control scheme over hypersonic tactical missile

    Science.gov (United States)

    Yi, Yan; Zhou, Fengqi

    2003-12-01

    This paper presents a brand-new tactical missile control scheme—variable centroid vector control according to the international highlight in the field of missile control and the research status of hypersonic missile control in China. Four critical problems related with the new control method are included: improving phase control in the spinning missile single-channel control; establishing variable centroid controlled spinning missile attitude dynamics equations; analyzing variable centroid control strategies and analyzing the stability of the controlled missile and implementing robust control. The achievements and results obtained are valuable and helpful to the theoretical explorations and engineering applications.

  8. The Rapid Decay property and centroids in groups

    OpenAIRE

    Sapir, Mark

    2014-01-01

    This is a survey of methods of proving or disproving the Rapid Decay property in groups. We present a centroid property of group actions on metric spaces. That property is a generalized (and corrected) version of the property (**)-relative hyperbolicity" from our paper with Cornelia Drutu, math/0405500, and implies the Rapid Decay (RD) property. We show that several properties which are known to imply RD also imply the centroid property. Thus uniform lattices in many semi-si...

  9. Maser Source-Finding Methods in HOPS

    Science.gov (United States)

    Walsh, A. J.; Purcell, C.; Longmore, S.; Jordan, C. H.; Lowe, V.

    2012-12-01

    The H2O Southern Galactic Plane Survey (HOPS) has observed 100 deg2 of the Galactic plane, using the Mopra radio telescope to search for emission from multiple spectral lines in the 12-mm band (19.5-27.5GHz). 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 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 spurious detections and is simple to implement. The disadvantage is that it is a manual method of finding sources and so is not practical on datasets much larger than HOPS, or for datasets with extended emission that needs to be characterised. We outline a two-stage method for the most efficient means of finding masers, using DUCHAMP.

  10. Optimisation of centroiding algorithms for photon event counting imaging

    International Nuclear Information System (INIS)

    Approaches to photon event counting imaging in which the output events of an image intensifier are located using a centroiding technique have long been plagued by fixed pattern noise in which a grid of dimensions similar to those of the CCD pixels is superimposed on the image. This is caused by a mismatch between the photon event shape and the centroiding algorithm. We have used hyperbolic cosine, Gaussian, Lorentzian, parabolic as well as 3-, 5-, and 7-point centre of gravity algorithms, and hybrids thereof, to assess means of minimising this fixed pattern noise. We show that fixed pattern noise generated by the widely used centre of gravity centroiding is due to intrinsic features of the algorithm. Our results confirm that the recently proposed use of Gaussian centroiding does indeed show a significant reduction of fixed pattern noise compared to centre of gravity centroiding (Michel et al., Mon. Not. R. Astron. Soc. 292 (1997) 611-620). However, the disadvantage of a Gaussian algorithm is a centroiding failure for small pulses, caused by a division by zero, which leads to a loss of detective quantum efficiency (DQE) and to small amounts of residual fixed pattern noise. Using both real data from an image intensifier system employing a progressive scan camera, framegrabber and PC, and also synthetic data from Monte-Carlo simulations, we find that hybrid centroiding algorithms can reduce the fixed pattern noise without loss of resolution or loss of DQE. Imaging a test resolution or loss of DQE. Imaging a test pattern to assess the features of the different algorithms shows that a hybrid of Gaussian and 3-point centre of gravity centroiding algorithms results in an optimum combination of low fixed pattern noise (lower than a simple Gaussian), high DQE, and high resolution. The Lorentzian algorithm gives the worst results in terms of high fixed pattern noise and low resolution, and the Gaussian and hyperbolic cosine algorithms have the lowest DQEs

  11. 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.

  12. 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...

  13. Finding protein sites using machine learning methods

    Directory of Open Access Journals (Sweden)

    Jaime Leonardo Bobadilla Molina

    2010-04-01

    Full Text Available The increasing amount of protein three-dimensional (3D structures determined by x-ray and NMR technologies as well as structures predicted by computational methods results in the need for automated methods to provide inital annotations. We have developed a new method for recognizing sites in three-dimensional protein structures. Our method is based on a previosly reported algorithm for creating descriptions of protein microenviroments using physical and chemical properties at multiple levels of detail. The recognition method takes three inputs: 1. A set of control nonsites that share some structural or functional role. 2. A set of control nonsites that lack this role. 3. A single query site. A support vector machine classifier is built using feature vectors where each component represents a property in a given volume. Validation against an independent test set shows that this recognition approach has high sensitivity and specificity. We also describe the results of scanning four calcium binding proteins (with the calcium removed using a three dimensional grid of probe points at 1.25 angstrom spacing. The system finds the sites in the proteins giving points at or near the blinding sites. Our results show that property based descriptions along with support vector machines can be used for recognizing protein sites in unannotated structures.

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

    Science.gov (United States)

    Hele, Timothy J. H.; Willatt, Michael J.; Muolo, Andrea; Althorpe, Stuart C.

    2015-05-01

    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.

  15. Relation of centroid molecular dynamics and ring-polymer molecular dynamics to exact quantum dynamics

    CERN Document Server

    Hele, Timothy J H; Muolo, Andrea; Althorpe, Stuart C

    2015-01-01

    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.

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

    Science.gov (United States)

    Zhang, Ye; Wang, Yanjie

    2006-01-01

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

  19. Maser Source Finding Methods in HOPS

    OpenAIRE

    Walsh, Andrew J.; 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...

  20. 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...

  1. Methods and findings of the SNR study

    International Nuclear Information System (INIS)

    A featfinding committee of the German Federal Parliament in July 1980 recommended to perform a ''risk-oriented study'' of the SNR-300, the German 300 MW fast breeder prototype reactor being under construction in Kalkar. The main aim of this study was to allow a comparative safety evaluation between the SNR-300 and a modern PWR, thus to prepare a basis for a political decision on the SNR-300. Methods and main results of the study are presented in this paper. In the first step of the risk analysis six groups of accidents have been identified which may initiate core destruction. These groups comprise all conceivable courses, potentially leading to core destruction. By reliability analyses, expected frequency of each group has been calculated. In the accident analysis potential failure modes of the reactor tank have been investigated. Core destruction may be accompanied by the release of significant amounts of mechanical energy. The primary coolant system of SNR-300 is designed to withstand mechanical energy releases up to 370 MJ. Design features make it possible to cool the molten core inside the reactor tank. (orig./RW)

  2. Research on Centroid Position for Stairs Climbing Stability of Search and Rescue Robot

    OpenAIRE

    Yan Guo; Aiguo Song; Jiatong Bao; Huatao Zhang; Hongru Tang

    2011-01-01

    This paper represents the relationship between the stability of stairs climbing and the centroid position of the search and rescue robot. The robot system is considered as a mass point-plane model and the kinematics features are analyzed to find the relationship between centroid position and the maximal pitch angle of stairs the robot could climb up. A computable function about this relationship is given in this paper. During the stairs climbing, there is a maximal stability-keeping angle dep...

  3. Spherical Layout Implementation using Centroidal Voronoi Tessellations

    CERN Document Server

    Larrea, Martin; Martig, Sergio; Castro, Silvia

    2009-01-01

    The 3D tree visualization faces multiple challenges: the election of an appropriate layout, the use of the interactions that make the data exploration easier and a metaphor that helps in the process of information understanding. A good combination of these elements will result in a visualization that effectively conveys the key features of a complex structure or system to a wide range of users and permits the analytical reasoning process. In previous works we presented the Spherical Layout, a technique for 3D tree visualization that provides an excellent base to achieve those key features. The layout was implemented using the TriSphere algorithm, a method that discretized the spheres's surfaces with triangles to achieve a uniform distribution of the nodes. The goal of this work was centered in a new algorithm for the implementation of the Spherical layout; we called it the Weighted Spherical Centroidal Voronoi Tessellations (WSCVT). In this paper we present a detailed description of this new implementation an...

  4. 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

  5. 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.

  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. 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.

  8. 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 populationle is more appropriate for this population. (orig.)

  9. 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.)

  10. Comparing the performance of open loop centroiding techniques in the Raven MOAO system

    Science.gov (United States)

    Andersen, David R.; Bradley, Colin; Gamroth, Darryl; Kerley, Dan; Lardière, Olivier; Véran, Jean-Pierre

    2014-08-01

    Raven is a multi-object adaptive optics (MOAO) demonstrator that will be mounted on the NIR Nasmyth platform of the Subaru telescope in May, 2014. Raven can use three open-loop NGS WFSs and an on-axis LGS WFS to control DMs in two separate science pick-off arms. Centroiding in open loop AO systems like Raven is more difficult than in closed loop AO systems because the Shack-Hartmann spots will not be driven to the same spot on a detector. Rather the spots can fall on any combination of pixels because the WFSs need to have sufficient dynamic range to measure the full turbulence. In this paper, we compare correlation and thresholded center of gravity (tCOG) centroiding methods in simulation, with Raven using its calibration unit, and on-sky. Each method has its own advantages. Correlation centroiding is superior to tCOG centroiding for faint NGSs and for extended sources (Raven open loop WFSs do not contain ADCs so spots will become elongated). We expect that correlation centroiding will push the limiting magnitude of Raven NGSs fainter by roughly one magnitude. Correlation centroiding is computationally more intensive, however, and actually will limit Raven's sampling rate for shorter integrations. Therefore, for bright stars with sufficiently high signal-to-noise, Raven can be run significantly faster and with superior performance using the tCOG method. Here we quantify both the performance and timing differences of these two centroiding methods in simulation, in the lab and on sky using Raven.

  11. Centroids and widths in the symplectic collective model

    International Nuclear Information System (INIS)

    Methods of statistical spectroscopy are applied to the symplectic collective shell model. Analytic expression are given for determining the distribution of U(3) centroids within an irreducible representation of Sp(3, R) for the Bohr-Mottelson collective V(#betta#, #betta#) potential. For 20Ne, a comparison is made between statistical predictions and shell-model results for the U(3) content of states in the ground state domain. The results suggest that statistical measures can be used reliably to truncate symplectic model spaces so that microscopic calculations become feasible. (orig.)

  12. A new method for finding vacua in string phenomenology

    International Nuclear Information System (INIS)

    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)

  13. 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.

  14. ASTROMETRIC IMAGE CENTROID DISPLACEMENTS DUE TO GRAVITATIONAL MICROLENSING BY THE ELLIS WORMHOLE

    International Nuclear Information System (INIS)

    Continuing work initiated in an earlier publication, we study the gravitational microlensing effects of the Ellis wormhole in the weak-field limit. First, we find a suitable coordinate transformation, such that the lens equation and analytic expressions of the lensed image positions can become much simpler. Second, we prove that two images always appear for the weak-field lens by the Ellis wormhole. By using these analytic results, we discuss astrometric image centroid displacements due to gravitational microlensing by the Ellis wormhole. The astrometric image centroid trajectory by the Ellis wormhole is different from the standard one by a spherical lensing object that is expressed by the Schwarzschild metric. The anomalous shift of the image centroid by the Ellis wormhole lens is smaller than that by the Schwarzschild lens, provided that the impact parameter and the Einstein ring radius are the same. Therefore, the lensed image centroid by the Ellis wormhole moves slower. Such a difference, although it is very small, will be, in principle, applicable for detecting or constraining the Ellis wormhole by using future high-precision astrometry observations. In particular, the image centroid position gives us additional information, so that the parameter degeneracy existing in photometric microlensing can be partially broken. The anomalous shift reaches the order of a few micro arcseconds, if our galaxy hosts a wormhole with throat radius larger than 105 km. Wat radius larger than 105 km. When the source moves tangentially to the Einstein ring, for instance, the maximum position shift of the image centroid by the Ellis wormhole is 0.18 normalized by the Einstein ring radius. For the same source trajectory, the maximum difference between the centroid displacement by the Ellis wormhole lens and that by the Schwarzschild one with the same Einstein ring radius is -0.16 in the units of the Einstein radius, where the negative means that the astrometric displacement by the Ellis wormhole lens is smaller than that by the Schwarzschild one.

  15. The characteristic function method of finding first integrals of ODEs

    International Nuclear Information System (INIS)

    The problem to prove that the system of a differential equation is 'ordered' or chaotic is equally difficult and important. In general, the ordinary differential equation (ODE) which is integrable implies that its solutions are ordered, which excludes the occurrence of chaos. In this paper, the integrability of ODEs of polynomial type is studied. A effective method, namely, the characteristic function method of finding their first integrals is proposed. The method is easily carried out through computers. In addition, its properties are discussed. As applications, the first integrals of some usual systems are given

  16. Automatic centroid detection and surface measurement with a digital Shack–Hartmann wavefront sensor

    International Nuclear Information System (INIS)

    With the breakthrough of manufacturing technologies, the measurement of surface profiles is becoming a big issue. A Shack–Hartmann wavefront sensor (SHWS) provides a promising technology for non-contact surface measurement with a number of advantages over interferometry. The SHWS splits the incident wavefront into many subsections and transfers the distorted wavefront detection into the centroid measurement. So the accuracy of the centroid measurement determines the accuracy of the SHWS. In this paper, we have presented a new centroid measurement algorithm based on an adaptive thresholding and dynamic windowing method by utilizing image-processing techniques. Based on this centroid detection method, we have developed a digital SHWS system which can automatically detect centroids of focal spots, reconstruct the wavefront and measure the 3D profile of the surface. The system has been tested with various simulated and real surfaces such as flat surfaces, spherical and aspherical surfaces as well as deformable surfaces. The experimental results demonstrate that the system has good accuracy, repeatability and immunity to optical misalignment. The system is also suitable for on-line applications of surface measurement

  17. 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...

  18. 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.

  19. Measurement of centroid trajectory of Dragon-I electron beam

    International Nuclear Information System (INIS)

    The control of the electron beam in an intense current linear induction accelerator (LIA) is very important. The center position of the electron beam and the beam profile are two important parameters which should be measured accurately. The setup of a time-resolved measurement system and a data processing method for determining the beam center position are introduced for the purpose of obtaining Dragon-I electron beam trajectory including beam profile. The actual results show that the centroid position error can be controlled in one to two pixels. the time-resolved beam centroid trajectory of Dragon-I (18.5 MeV, 2 kA, 90 ns) is obtained recently in 10 ns interval, 3 ns exposure time with a multi-frame gated camera. The results show that the screw movement of the electron beam is mainly limited in an area with a radius of 0.5 mm and the time-resolved diameters of the beam are 8.4 mm, 8.8 mm, 8.5 mm, 9.3 mm and 7.6 mm. These results have provided a very important support to several research areas such as beam trajectory tuning and beam transmission. (authors)

  20. 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.

  1. Comparison of decision tree methods for finding active objects

    CERN Document Server

    Zhao, Y

    2007-01-01

    The automated classification of objects from large catalogues or survey projects is an important task in many astronomical surveys. Faced with various classification algorithms, astronomers should select the method according to their requirements. Here we describe several kinds of decision trees for finding active objects by multi-wavelength data, such as REPTree, Random Tree, Decision Stump, Random Forest, J48, NBTree, AdTree. All decision tree approaches investigated are in the WEKA package. The classification performance of the methods is presented. In the process of classification by decision tree methods, the classification rules are easily obtained, moreover these rules are clear and easy to understand for astronomers. As a result, astronomers are inclined to prefer and apply them, thus know which attributes are important to discriminate celestial objects. The experimental results show that when various decision trees are applied in discriminating active objects (quasars, BL Lac objects and active galax...

  2. 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...

  3. Computing the apparent centroid of radar targets

    Energy Technology Data Exchange (ETDEWEB)

    Lee, C.E.

    1996-12-31

    A high-frequency multibounce radar scattering code was used as a simulation platform for demonstrating an algorithm to compute the ARC of specific radar targets. To illustrate this simulation process, several targets models were used. Simulation results for a sphere model were used to determine the errors of approximation associated with the simulation; verifying the process. The severity of glint induced tracking errors was also illustrated using a model of an F-15 aircraft. It was shown, in a deterministic manner, that the ARC of a target can fall well outside its physical extent. Finally, the apparent radar centroid simulation based on a ray casting procedure is well suited for use on most massively parallel computing platforms and could lead to the development of a near real-time radar tracking simulation for applications such as endgame fuzing, survivability, and vulnerability analyses using specific radar targets and fuze algorithms.

  4. Centroid and moments of an area using a digitizer

    Science.gov (United States)

    Patch, R. W.

    1976-01-01

    The centroid and moments of an area program provides the centroid, moments of inertia, product of inertia, radii of gyration, and area of any closed planar geometric figure. The figure must be available in graphic form and is digitized once with chart digitizer (graphic tablet). The digitizer origin may be set anywhere on the digitizer table. After digitizing, fifteen quantities are calculated and displayed: (1) area (2) moment of inertia of area with respect to digitizer x-axis, (3) moment of inertia of area with respect to digitizer y-axis, (4) product of inertia of area with respect to digitizer axes, (5) first moment of x for digitizer axes, (6) first moment of y for digitizer axes, (7) x coordinate of centroid, (8) y coordinate of centroid, (9) moment of area inertia of with respect to x axis through centroid, (10) moment of inertia of area with respect to y axis through centroid, (11) product inertia of area with respect to x and y axes through centroid, (12) polar moment of inertia of area around centroid, (13) radius of gyration about digitizer x axis, (14) radius of gyration about digitizer y-axis; and (15) variance in the x-direction.

  5. 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.

  6. Transverse centroid oscillations in solenoidially focused beam transport lattices

    International Nuclear Information System (INIS)

    Linear equations of motion are derived that describe small-amplitude centroid oscillations induced by displacement and rotational misalignments of the focusing solenoids in the transport lattice, dipole steering elements, and initial centroid offset errors. These equations are analyzed in a local rotating Larmor frame to derive complex-variable 'alignment functions' and 'bending functions' that efficiently describe the characteristics of the centroid oscillations induced by mechanical misalignments of the solenoids and dipole steering elements. The alignment and bending functions depend only on properties of the ideal lattice in the absence of errors and steering and have associated expansion amplitudes set by the misalignments and steering fields. Applications of this formulation are presented for statistical analysis of centroid deviations, calculation of actual lattice misalignments from centroid measurements, and optimal beam steering

  7. Transverse Centroid Oscillations in Solenoidially Focused Beam Transport Lattices

    Energy Technology Data Exchange (ETDEWEB)

    Lund, S M; Wootton, C J; Lee, E P

    2008-08-01

    Linear equations of motion are derived that describe small-amplitude centroid oscillations induced by displacement and rotational misalignments of the focusing solenoids in the transport lattice, dipole steering elements, and initial centroid offset errors. These equations are analyzed in a local rotating Larmor frame to derive complex-variable 'alignment functions' and 'bending functions' that efficiently describe the characteristics of the centroid oscillations induced by mechanical misalignments of the solenoids and dipole steering elements. The alignment and bending functions depend only on properties of the ideal lattice in the absence of errors and steering and have associated expansion amplitudes set by the misalignments and steering fields. Applications of this formulation are presented for statistical analysis of centroid deviations, calculation of actual lattice misalignments from centroid measurements, and optimal beam steering.

  8. Transverse centroid oscillations in solenoidially focused beam transport lattices

    Energy Technology Data Exchange (ETDEWEB)

    Lund, Steven M.; Wootton, Christopher J.; Lee, Edward P.

    2008-08-01

    Linear equations of motion are derived that describe small-amplitude centroid oscillations induced by displacement and rotational misalignments of the focusing solenoids in the transport lattice, dipole steering elements, and initial centroid offset errors. These equations are analyzed in a local rotating Larmor frame to derive complex-variable"alignment functions" and"bending functions" that efficiently describe the characteristics of the centroid oscillations induced by mechanical misalignments of the solenoids and dipole steering elements. The alignment and bending functions depend only on properties of the ideal lattice in the absence of errors and steering and have associated expansion amplitudes set by the misalignments and steering fields. Applications of this formulation are presented for statistical analysis of centroid deviations, calculation of actual lattice misalignments from centroid measurements, and optimal beam steering.

  9. Comparison of decision tree methods for finding active objects

    Science.gov (United States)

    Zhao, Yongheng; Zhang, Yanxia

    The automated classification of objects from large catalogs or survey projects is an important task in many astronomical surveys. Faced with various classification algorithms, astronomers should select the method according to their requirements. Here we describe several kinds of decision trees for finding active objects by multi-wavelength data, such as REPTree, Random Tree, Decision Stump, Random Forest, J48, NBTree, AdTree. All decision tree approaches investigated are in the WEKA package. The classification performance of the methods is presented. In the process of classification by decision tree methods, the classification rules are easily obtained, moreover these rules are clear and easy to understand for astronomers. As a result, astronomers are inclined to prefer and apply them, thus know which attributes are important to discriminate celestial objects. The experimental results show that when various decision trees are applied in discriminating active objects (quasars, BL Lac objects and active galaxies) from non-active objects (stars and galaxies), ADTree is the best only in terms of accuracy, Decision Stump is the best only considering speed, J48 is the optimal choice considering both accuracy and speed.

  10. 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...

  11. Time delay and magnification centroid due to gravitational lensing by black holes and naked singularities

    OpenAIRE

    Virbhadra, K S; Keeton, C. R.

    2007-01-01

    We model the massive dark object at the center of the Galaxy as a Schwarzschild black hole as well as Janis-Newman-Winicour naked singularities, characterized by the mass and scalar charge parameters, and study gravitational lensing (particularly time delay, magnification centroid, and total magnification) by them. We find that the lensing features are qualitatively similar (though quantitatively different) for the Schwarzschild black holes, weakly naked, and marginally stro...

  12. 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.

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

    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,...

  14. Ambiguity Of Doppler Centroid In Synthetic-Aperture Radar

    Science.gov (United States)

    Chang, Chi-Yung; Curlander, John C.

    1991-01-01

    Paper discusses performances of two algorithms for resolution of ambiguity in estimated Doppler centroid frequency of echoes in synthetic-aperture radar. One based on range-cross-correlation technique, other based on multiple-pulse-repetition-frequency technique.

  15. Methods to Find the Number of Latent Skills

    Science.gov (United States)

    Beheshti, Behzad; Desmarais, Michel C.; Naceur, Rhouma

    2012-01-01

    Identifying the skills that determine the success or failure to exercises and question items is a difficult task. Multiple skills may be involved at various degree of importance, and skills may overlap and correlate. In an effort towards the goal of finding the skills behind a set of items, we investigate two techniques to determine the number of…

  16. 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 Unioopyright 1998 American Geophysical Union

  17. 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.

  18. 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.

  19. Class hierarchy method to find Change-Proneness

    OpenAIRE

    Gaikwad, Malan V.; 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...

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

    OpenAIRE

    Hele, Timothy J. H.; Willatt, Michael J.; Muolo, Andrea; Althorpe, Stuart C.

    2015-01-01

    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...

  1. Mixed Method Research: Instruments, Validity, Reliability and Reporting Findings

    OpenAIRE

    Mohammad Zohrabi

    2013-01-01

    The mixed method approaches have recently risen to prominence. The reason that more researchers are opting for these types of research is that both qualitative and quantitative data are simultaneously collected, analyzed and interpreted. In this article the main research instruments (questionnaire, interview and classroom observation) usually used in the mixed method designs are presented and elaborated on. It is believed that using different types of procedures for collecting data and obtain...

  2. Finding diabetics--a method of screening in general practice.

    OpenAIRE

    Bullimore, S. P.; Keyworth, C.

    1997-01-01

    BACKGROUND: It is well known that many diabetic patients go undiagnosed until complications have started to develop. Screening can be expensive in time and money, and ineffective, and is therefore unpopular with general practitioners (GPs). AIM: This study aimed to develop a screening method that was cost-effective and practical within the setting of an ordinary general practice. METHOD: Urine-testing sticks for glucose were sent with an explanatory letter to all (1736) non-diabetic subjects ...

  3. 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.

  4. Plasma Channel Diagnostic Based on Laser Centroid Oscillations

    International Nuclear Information System (INIS)

    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 (14Wcm-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.

  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. Esthesioneuroblastoma methods of intracranial extension: CT and MR imaging findings

    Energy Technology Data Exchange (ETDEWEB)

    Yu, Tian; Xu, Yi-Kai; Jia, Fei-Ge; Yang, Rui-Meng; Feng, Jie; Ye, Xiang-Hua; Qiu, Ying-Wei [Southern Medical University, Department of Medical Imaging Center, Nan Fang Hospital, Guangzhou, Guangdong (China); Li, Long [Chinese People' s Armed Police Forces, Department of Radiology, Guangdong Provincial Corps Hospital, Guangzhou (China); Duan, Gang; Wu, Yuan-Kui [Southern Medical University, Department of Radiology, Nan Fang Hospital, Guangzhou (China); Li, Hua-Yu [No. 458 Hospital of PLA, Department of Medical Imaging Center, Guangzhou (China)

    2009-12-15

    Esthesioneuroblastoma (ENB) is an aggressive neuroectodermal malignancy in the upper nasal cavity with local infiltration and lymphatic or hematogenous metastasis. The purpose of this paper is to document three types of direct intracranial extensions by ENB using computed tomography (CT) and magnetic resonance imaging (MRI). Eleven patients with pathologically confirmed ENB were admitted in our hospital between December 2002 and December 2008. Their magnetic resonance (MR; n = 10) and CT (n = 8) images were retrospectively reviewed, and particular attention was paid to tumor location and extension, enhancement pattern, cervical lymph node metastasis, and Kadish stage. The majority of patients were male (8/11) with Kadish stage C tumor (10/11). Three types of direct intracranial extension by ENBs were put forward according to their MR and CT findings. The primary tumors were well-defined soft-tissue masses centered in the roof of the nasal cavity eroding into the paranasal sinuses (11/11), the contralateral nasal cavity (4/11), the cranial cavity (5/11), and the fossa orbitalis (3/11). The tumor parenchyma were hypointensity on T1-weighted images, heterogeneous hyperintensity on T2-weighted images, and isodensity or slight hyperdensity on CT images with scattered necroses (4/11) and marginal cysts(4/11). Their enhancements were significant and inhomogeneous. Cervical lymph nodes metastases were observed in four patients (4/11), but no pathologically proved distant metastasis was observed. Three types of direct intracranial extensions by ENB can be found on CT and MRI: cranio-orbital-nasal-communicating ENB, cranio-nasal-communicating ENB, and orbital-nasal-communicating ENB. (orig.)

  7. A evolutionary method for finding communities in bipartite networks

    CERN Document Server

    WeiHua, Zhan; Jihong, Guan; Shuigeng, Zhou

    2010-01-01

    Common practice in community structure detection is to develop different methods for different classes of networks. Here, we first show that unipartite networks and directed networks can be uniformly represented as bipartite networks, and their modularity completely consist with that for bipartite networks. To optimize the bipartite modularity, we then present a modified adaptive genetic algorithm, called as MMOGA, which is especially suited for community structure detection. In MMOGA, we introduce a new measure for the informativeness of a locus instead of the standard deviation, which can exactly determine those loci to mutate. This measure is the bias between the distribution of a locus over the current population and the uniform distribution of the locus, i.e., Kull-back Divergence between them. Moreover, we develop a reassignment technique for differentiating the informative state a locus has attained from the random state at initial phase. Also we present a modified mutation rule which incorporating rel...

  8. Finding Similarities in Ancient Ceramics by EDXRF and Multivariate Methods

    International Nuclear Information System (INIS)

    We have studied 39 samples of fragments from ceramic roof tiles with different stamps(Diamalas and Heraion), dated between 330 to 170 BC and found at the archaeological site of Dimales, some 30 km from the Adriatic coast. The data from these samples were compared with those obtained from 7 samples of similar objects and period with the stamp Heraion, found at the archaeological site of APOLLONIA. The samples were analyzed by energy-dispersive X -ray fluorescence(EDXRF), using of the x-ray lines of the elements to the intensity of the Compton peak. The results have been treated with diverse multivariate methods. The application of hierarchical cluster analysis and factor analysis permitted the identification of two main clusters. The first cluster is composed from the ''Heraion'' samples discovered in Apollonia, while the second comprises all the samples discovered in Dimale independent of their stamp. (authors)

  9. Centroid based Categorization Approach for Extraction of Body Sensor Network Data

    Directory of Open Access Journals (Sweden)

    Setu Ku. Chaturvedi

    2010-01-01

    Full Text Available Monitoring human activities using wearable wireless sensor nodes has the potential to enable many useful applications for everyday situations. The long-term lifestyle categorization can greatly improve healthcare by gathering information about quality of life; aiding the diagnosis and tracking of certain diseases. The deployment of an automatic and computationally-efficient algorithm reduces the complexities involved in the detection and recognition of human activities in a distributed on Body sensor network server. Directory service is a useful aid human looking for information on Network Data. A directory services is a pre-categorized list of topics containing many links for each topic. However, most directory services are maintained manually now and face many drawbacks. Therefore the task of automatic categorization of new data into the topics of directory services becomes very necessary. BSN data categorization is more difficult due to a large variation of noisy information embedded in Sensor network data. This paper suggests a new Centroid based approach for Categorization for BSN data. We further introduce a new algorithm through centroid based approach for extraction of BSN data categorization and show that it achieves about more improvement over other BSN data categorization methods. Experimental results show that our proposed Centroid-based BSN data categorization algorithm achieves an approximately 13.8% improvement for BSN data categorization algorithm.

  10. 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...

  11. 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 ...

  12. Conflicting Findings in Mixed Methods Research: An Illustration from an Israeli Study on Immigration

    Science.gov (United States)

    Slonim-Nevo, Vered; Nevo, Isaac

    2009-01-01

    Combining diverse methods in a single study raises a problem: What should be done when the findings of one method of investigation conflict with those of another? The authors illustrate this problem using an example in which three study phases--quantitative, qualitative, and intervention--are applied. The findings from the quantitative phase did…

  13. Research on fabrication of helical-core fiber based on the coordinates of the centroid

    Science.gov (United States)

    Geng, Tao; Xue, Renfeng; Yang, Wenlei; Geng, Shixin; Liu, Zhaojun; Ye, Tian

    2014-09-01

    Helical core optical fiber is used to achieve high power fiber laser output and polarization state control, and it has become a hot issue of current research due to its unique characteristics of chiral medium. The key difficult point is critical concentric alignment between the actual rotational center and the optical fiber core in helical core fiber manufacturing process. This paper proposed a new alignment method based on the coordinates of centroid. That is, injecting light to the main and sub fiber core which is fixed on the rotating clamping apparatus, acquiring two coordinates of the energy center in output field spot image with the help of the microscopic imaging system by using the squared weighted centroid method. X-axis is defined as the two fiber core connection direction, which perpendicular direction is Y-axis, and the origin is the center of main fiber core, so the correspondence between the main fiber core XY coordinate system and the rotating clamping apparatus X0Y0 coordinate system is available. Main fiber core rotation center coordinates X'Y' can be obtained by fitting, and the X0Y0 adjustment of clamping apparatus can be also acquired by coordinate transformation. Experimentally measured eccentricity error can be controlled around 8?m, which achieved concentricity precise adjustment. The experimental device has advantages of small size, stable performance, high positioning accuracy, and this method overcomes the key technical difficulties of the helical core optical fiber preparation.

  14. 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.

  15. 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

  16. A fast algorithm to compute precise type-2 centroids for real-time control applications.

    Science.gov (United States)

    Chakraborty, Sumantra; Konar, Amit; Ralescu, Anca; Pal, Nikhil R

    2015-02-01

    An interval type-2 fuzzy set (IT2 FS) is characterized by its upper and lower membership functions containing all possible embedded fuzzy sets, which together is referred to as the footprint of uncertainty (FOU). The FOU results in a span of uncertainty measured in the defuzzified space and is determined by the positional difference of the centroids of all the embedded fuzzy sets taken together. This paper provides a closed-form formula to evaluate the span of uncertainty of an IT2 FS. The closed-form formula offers a precise measurement of the degree of uncertainty in an IT2 FS with a runtime complexity less than that of the classical iterative Karnik-Mendel algorithm and other formulations employing the iterative Newton-Raphson algorithm. This paper also demonstrates a real-time control application using the proposed closed-form formula of centroids with reduced root mean square error and computational overhead than those of the existing methods. Computer simulations for this real-time control application indicate that parallel realization of the IT2 defuzzification outperforms its competitors with respect to maximum overshoot even at high sampling rates. Furthermore, in the presence of measurement noise in system (plant) states, the proposed IT2 FS based scheme outperforms its type-1 counterpart with respect to peak overshoot and root mean square error in plant response. PMID:24691554

  17. An Inversion-Free Method for Finding Positive Definite Solution of a Rational Matrix Equation

    OpenAIRE

    Fazlollah Soleymani; Mahdi Sharifi; Solat Karimi Vanani; Farhad Khaksar Haghani; Adem K?l?çman

    2014-01-01

    A new iterative scheme has been constructed for finding minimal solution of a rational matrix equation of the form X + A*X?1A = I. The new method is inversion-free per computing step. The convergence of the method has been studied and tested via numerical experiments.

  18. Resolving Earthquake Directivity with Relative Centroid Location : A Case Study for the 18 April 2008 Illinois Earthquake

    Science.gov (United States)

    He, X.; Ni, S.

    2014-12-01

    Earthquake rupture directivity is essential for studying seismic hazard and understanding seismogenic processes by resolving the ruptured fault. Point source approximation with centroid moment tensor (CMT) or fault plane solution only provides two nodal planes instead of specifying the physical rupture plane, thus leading to fault plane ambiguity. For mega-earthquakes (M7+), slip distribution can be resolved through finite fault modeling (Ji et al., 2002). For moderate earthquakes (M4~6), relative source time function (RSTF) can be obtained from deconvolving the empirical green's functions or forward modeling, and the rupture directivity can be determined from fitting RSTF of stations with small azimuth gap in a dense seismic network(Luo et al., 2010). But for sparse network, station azimuthal coverage is not sufficient for such studies.We propose a technique to determine the rupture plane via measuring the spatial difference between centroid location and hypocenter. The technique involves of waveform time shift difference of mainshock and refer events (smaller events with similar focal mechanism), which calibrates errors due to velocity heterogeneity and absolute location error. Relative hypocenter locations and relative centroid locations are resolved by relative location method of onset travel times and waveform cross-correlation respectively. The difference between onset travel times and waveform-derived centroid times against the azimuthal variations is then used to infer the mainshock rupture directivity.We apply the method to the 2008 Illinois Mw5.2 earthquake. Four M3.4+ aftershocks are chosen as refer events, we generate synthetics using focal mechanism from SLU earthquake center, and measure the time shift difference for stations. The resolved rupture plane strikes northwest-southeast, consistent with spatial distribution of relocated aftershocks using hypoDD (Hongfeng Yang et al., 2009). The method works for earthquakes of unilateral rupture, which consist of 80% of all earthquake as demonstrated by previous studies.

  19. The Lagrangian multiplier method of finding upper and lower limits to critical stresses of clamped plates

    Science.gov (United States)

    Budiansky, Bernard; Hu, Pai C

    1946-01-01

    The theory of Lagrangian multipliers is applied to the problem of finding both upper and lower limits to the true compressive buckling stress of a clamped rectangular plate. The upper and lower limits thus bracket the true stress, which cannot be exactly found by the differential-equation approach. The procedure for obtaining the upper limit, which is believed to be new, presents certain advantages over the classical Rayleigh-Ritz method of finding upper limits. The theory of the lower-limit procedure has been given by Trefftz, but, in the present application, the method differs from that of Trefftz in a way that makes it inherently more quickly convergent. It is expected that in other buckling problems and in some vibration problems the Lagrangian multiplier method of finding upper and lower limits may be advantageously applied to the calculation of buckling stresses and natural frequencies.

  20. Reducing noise in moving-grid codes with strongly-centroidal Lloyd mesh regularization

    CERN Document Server

    Mocz, Philip; Pakmor, Rudiger; Genel, Shy; Springel, Volker; Hernquist, Lars

    2015-01-01

    A method for improving the accuracy of hydrodynamical codes that use a moving Voronoi mesh is described. Our scheme is based on a new regularization scheme that constrains the mesh to be centroidal to high precision while still allowing the cells to move approximately with the local fluid velocity, thereby retaining the quasi-Lagrangian nature of the approach. Our regularization technique significantly reduces mesh noise that is attributed to changes in mesh topology and deviations from mesh regularity. We demonstrate the advantages of our method on various test problems, and note in particular improvements obtained in handling shear instabilities, mixing, and in angular momentum conservation. Calculations of adiabatic jets in which shear excites Kelvin Helmholtz instability show reduction of mesh noise and entropy generation. In contrast, simulations of the collapse and formation of an isolated disc galaxy are nearly unaffected, showing that numerical errors due to the choice of regularization do not impact ...

  1. 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.

  2. 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.

  3. Lagrangian-based methods for finding MAP solutions for MRF models.

    Science.gov (United States)

    Storvik, G; Dahl, G

    2000-01-01

    Finding maximum a posteriori (MAP) solutions from noisy images based on a prior Markov random field (MRF) model is a huge computational task. In this paper, we transform the computational problem into an integer linear programming (ILP) problem. We explore the use of Lagrange relaxation (LR) methods for solving the MAP problem. In particular, three different algorithms based on LR are presented. All the methods are competitive alternatives to the commonly used simulation-based algorithms based on Markov Chain Monte Carlo techniques. In all the examples (including both simulated and real images) that have been tested, the best method essentially finds a MAP solution in a small number of iterations. In addition, LR methods provide lower and upper bounds for the posterior, which makes it possible to evaluate the quality of solutions and to construct a stopping criterion for the algorithm. Although additive Gaussian noise models have been applied, any additive noise model fits into the framework. PMID:18255417

  4. 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).

  5. "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…

  6. Error-finding and error-correcting methods for the start-up of the SLC

    International Nuclear Information System (INIS)

    During the commissioning of an accelerator, storage ring, or beam transfer line, one of the important tasks of an accelertor physicist is to check the first-order optics of the beam line and to look for errors in the system. Conceptually, it is important to distinguish between techniques for finding the machine errors that are the cause of the problem and techniques for correcting the beam errors that are the result of the machine errors. In this paper we will limit our presentation to certain applications of these two methods for finding or correcting beam-focus errors and beam-kick errors that affect the profile and trajectory of the beam respectively. Many of these methods have been used successfully in the commissioning of SLC systems. In order not to waste expensive beam time we have developed and used a beam-line simulator to test the ideas that have not been tested experimentally. To save valuable physicist's time we have further automated the beam-kick error-finding procedures by adopting methods from the field of artificial intelligence to develop a prototype expert system. Our experience with this prototype has demonstrated the usefulness of expert systems in solving accelerator control problems. The expert system is able to find the same solutions as an expert physicist but in a more systematic fashion. The methods used in these procedures and some of the recent applications will be described in this paper

  7. Resolution of the method of direction finding, which based on j - correlation processing P?????????? ??????????? ?????? ?????????? ?? ?????? j - ?????????????? ????????? ????????? ????????? ?????? ?????????? ?? ?????? J-????????????? ??????????

    Directory of Open Access Journals (Sweden)

    ?.?. ????????

    2010-04-01

    Full Text Available The analysis of the resolution of the J-correlation method of direction finding. The expressions defining the standard deviations of the difference of time delays of signals caused by the angular divergence between the directions of two equidistant targets. ???????? ?????? ??????????? ??????????? J-??????????????? ?????? ??????????. ???????? ?????????, ???????????? ???????????????????? ?????????? ???????? ????????? ???????? ????????, ????????? ??????? ???????????? ????? ????????????? ?? ??? ?????????????? ????. ????????? ?????? ?????????? ????????? J-????????????? ?????? ??????????. ???????? ??????, ?? ?????????? ??????????????????? ?????????? ??????? ??????? ???????? ????????, ?????????? ???????? ????????????? ??? ?????????? ?? ??? ?????????????? ????.

  8. 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 investire on the centroiding accuracy was investigated by experimental methods

  9. Changes of the centroid position of laser beams propagating through an optical system in turbulent atmosphere

    Science.gov (United States)

    Ji, Xiaoling; Baykal, Yahya; Jia, Xinhong

    2013-12-01

    In this paper, the effects of atmospheric turbulence, initial field amplitude, optical system and thermal blooming on the centroid position of laser beams propagating through the atmosphere are studied in detail. With the average over the ensemble of the turbulent medium, the centroid position is independent of turbulence. However, the centroid position depends on the centroid positions at the source plane and in the far-field, and the elements of ray-transfer-matrix. The physical reason why the centroid position changes on propagation is that the far-field centroid position is not located on the propagation z-axis due to the field phase distortion and the decentred intensity. The centroid position of laser beams with the spherical aberration and the decentred intensity is examined analytically. When laser beams with the decentred intensity propagate through the atmosphere, the effect of thermal blooming on the centroid position is investigated by using the four-dimensional (4D) computer code of the time-dependent propagation of high power laser beams through the atmosphere.

  10. Centroid offset estimation in the Fourier domain for a highly sensitive Shack–Hartmann wavefront sensor

    International Nuclear Information System (INIS)

    The estimation of the centroid offset can have an effect on the accuracy of wavefront measurements conducted by highly sensitive Shack–Hartmann wavefront sensors. In this paper, a novel offset estimation algorithm processed in the Fourier domain is proposed. This method can be used to process the offset estimation in the Fourier domain and is efficient in noise suppression. The principle of the algorithm is described in detail. Comparisons between the technique and two other widely used algorithms, the best-threshold center of gravity algorithm and the correlation algorithm, are performed theoretically using numerical simulation and experimentally using a Shack–Hartmann wavefront sensor. The results show that the proposed offset estimation algorithm is unbiased, as robust as the correlation algorithm, as fast as the best-threshold center of gravity algorithm, and achieves a good balance between precision and speed. (paper)

  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. Single-ended transition state finding with the growing string method.

    Science.gov (United States)

    Zimmerman, Paul M

    2015-04-01

    Reaction path finding and transition state (TS) searching are important tasks in computational chemistry. Methods that seek to optimize an evenly distributed set of structures to represent a chemical reaction path are known as double-ended string methods. Such methods can be highly reliable because the endpoints of the string are fixed, which effectively lowers the dimensionality of the reaction path search. String methods, however, require that the reactant and product structures are known beforehand, which limits their ability for systematic exploration of reactive steps. In this article, a single-ended growing string method (GSM) is introduced which allows for reaction path searches starting from a single structure. The method works by sequentially adding nodes along coordinates that drive bonds, angles, and/or torsions to a desired reactive outcome. After the string is grown and an approximate reaction path through the TS is found, string optimization commences and the exact TS is located along with the reaction path. Fast convergence of the string is achieved through use of internal coordinates and eigenvector optimization schemes combined with Hessian estimates. Comparison to the double-ended GSM shows that single-ended method can be even more computationally efficient than the already rapid double-ended method. Examples, including transition metal reactivity and a systematic, automated search for unknown reactivity, demonstrate the efficacy of the new method. This automated reaction search is able to find 165 reaction paths from 333 searches for the reaction of NH3 BH3 and (LiH)4 , all without guidance from user intuition. PMID:25581279

  14. 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

  15. Neutron radiography with sub-15 ?m resolution through event centroiding

    International Nuclear Information System (INIS)

    Conversion of thermal and cold neutrons into a strong ?1 ns electron pulse with an absolute neutron detection efficiency as high as 50–70% makes detectors with 10B-doped Microchannel Plates (MCPs) very attractive for neutron radiography and microtomography applications. The subsequent signal amplification preserves the location of the event within the MCP pore (typically 6–10 ?m in diameter), providing the possibility to perform neutron counting with high spatial resolution. Different event centroiding techniques of the charge landing on a patterned anode enable accurate reconstruction of the neutron position, provided the charge footprints do not overlap within the time required for event processing. The new fast 2×2 Timepix readout with >1.2 kHz frame rates provides the unique possibility to detect neutrons with sub-15 ?m resolution at several MHz/cm2 counting rates. The results of high resolution neutron radiography experiments presented in this paper, demonstrate the sub-15 ?m resolution capability of our detection system. The high degree of collimation and cold spectrum of ICON and BOA beamlines combined with the high spatial resolution and detection efficiency of MCP-Timepix detectors are crucial for high contrast neutron radiography and microtomography with high spatial resolution. The next generation of Timepix electronics with sparsified readout should enable counting rates in excess of 107 n/cm2/s taking full advantage of high beam intensity of present brightest neutron imaging facilities.

  16. 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...

  17. New Method for Finding an Optimal Solution to Quadratic Programming Problems

    Directory of Open Access Journals (Sweden)

    R. Mekki

    2010-01-01

    Full Text Available The aim of this study is to present a new method for finding an optimal solution to quadratic programming problems. The principle of the method is based on calculating the value of critical point. If the critical point belongs to the set of feasible solutions, so the optimal solution to our problem is the critical point itself. If the critical point is not at in the feasible solution set, a new feasible constraint set is built by a homographic transform, in such a way that the projection of the critical point of the objective function onto this set produces the exact solution to the problem on hand. It should be noted here that the objective function may be convex or not convex. On the other hand the search for the optimal solution is to find the hyper plane separating the convex and the critical point. Notice that one does not need to transform the quadratic problem into an equivalent linear one as in the numerical methods; the method is purely analytical and avoids the usage of initial solution. An algorithm computing the optimal solution of the concave function has given.

  18. 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

  19. 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...

  20. 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.

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

    Science.gov (United States)

    Maronsson, Jón Bergmann; Jónsson, Hannes; Vegge, Tejs

    2012-02-28

    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. PMID:22262088

  2. 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.

  3. 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.

  4. Centroid propagation through optical systems with ABCD kernels and nonuniform or finite apertures

    OpenAIRE

    Lancis Sáez, Jesús; Martínez Cuenca, Raúl; Ares, Jorge; Bará, Salvador

    2010-01-01

    If the propagation of a light field can be satisfactorily described by a diffraction integral with an ABCD kernel, the propagation of its irradiance centroid is completely determined by the corresponding ABCD ray-transfer matrix in exactly the same way as if the centroid path were a conventional geometrical ray. However, potentially significant deviations from this geometrical propagation rule may arise in the presence of finite or nonuniform apertures truncating or otherwise modifying the in...

  5. Time delay and magnification centroid due to gravitational lensing by black holes and naked singularities

    International Nuclear Information System (INIS)

    We model the massive dark object at the center of the Galaxy as a Schwarzschild black hole as well as Janis-Newman-Winicour naked singularities, characterized by the mass and scalar charge parameters, and study gravitational lensing (particularly time delay, magnification centroid, and total magnification) by them. We find that the lensing features are qualitatively similar (though quantitatively different) for Schwarzschild black holes, weakly naked, and marginally strongly naked singularities. However, the lensing characteristics of strongly naked singularities are qualitatively very different from those due to Schwarzschild black holes. The images produced by Schwarzschild black hole lenses and weakly naked and marginally strongly naked singularity lenses always have positive time delays. On the other hand, strongly naked singularity lenses can give rise to images with positive, zero, or negative time delays. In particular, for a large angular source position the direct image (the outermost image on the same side as the source) due to strongly naked singularity lensing always has a negative time delay. We also found that the scalar field decreases the time delay and increases the total magnification of images; this result could have important implications for cosmology. As the Janis-Newman-Winicour metric also describes the exterior gravitational field of a scalar star, naked singularities as well as scalar star lenses, if these exist in nature, will serve as more these exist in nature, will serve as more efficient cosmic telescopes than regular gravitational lenses

  6. 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)

  7. Centroid based clustering of high throughput sequencing reads based on n-mer counts

    Science.gov (United States)

    2013-01-01

    Background Many problems in computational biology require alignment-free sequence comparisons. One of the common tasks involving sequence comparison is sequence clustering. Here we apply methods of alignment-free comparison (in particular, comparison using sequence composition) to the challenge of sequence clustering. Results We study several centroid based algorithms for clustering sequences based on word counts. Study of their performance shows that using k-means algorithm with or without the data whitening is efficient from the computational point of view. A higher clustering accuracy can be achieved using the soft expectation maximization method, whereby each sequence is attributed to each cluster with a specific probability. We implement an open source tool for alignment-free clustering. It is publicly available from github: https://github.com/luscinius/afcluster. Conclusions We show the utility of alignment-free sequence clustering for high throughput sequencing analysis despite its limitations. In particular, it allows one to perform assembly with reduced resources and a minimal loss of quality. The major factor affecting performance of alignment-free read clustering is the length of the read. PMID:24011402

  8. A measure of variable planar locations anchored on the centroid of the vowel space : A sociophonetic research tool

    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 of desiderata for choice of normalization algorithm(s) based on replicable procedures. We then present the principles of centroid-based normalization and account for its performance in recent road tests. In sections 4 and 5 we introduce a method that utilizes the centroid of the speaker’s vowel space as an anchor point or vertex for calculation of planar locations on formant plots, permitting quantification of the distribution of vowel tokens within the space. This information, along with details such as Euclidean distances, can then be used to precisely pinpoint the trajectories of diachronic change, for instance over a set of speakers in different age groups within a defined speech community. This has the advantage of mathematical reproducibility, and reduces the level of subjectivity in visual analyses of formant plots used in investigations of vowel variability and change in progress.

  9. 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.

  10. Detection of a surface breaking crack by using the centroid variations of laser ultrasonic spectrums

    International Nuclear Information System (INIS)

    A laser ultrasonic system is a non-contact inspection device with a wide-band spectrum and a high spatial resolution. It provides absolute measurements of the moving distance and it can be applied to hard-to-access locations including curved or rough surfaces like in a nuclear power plant. In this paper, we have investigated the detection methods of the depth of a surface-breaking crack by using the surface wave of a laser ultrasound. The filtering function of a surface-breaking crack is a kind of a low-pass filter. The higher frequency components are more highly decreased in proportion to the crack depth. Also, the center frequency value of each ultrasound spectrum is decreased in proportion to the crack depth. We extracted the depth information of a surface-breaking crack by observing the centroid variation of the frequency spectrum. We describe the experimental results to detect the crack depth information by using the peak-to-valley values in the time domain and the center frequency values in the frequency domain.

  11. Ranked centroid projection: a data visualization approach with self-organizing maps.

    Science.gov (United States)

    Yen, G G; Wu, Z

    2008-02-01

    The self-organizing map (SOM) is an efficient tool for visualizing high-dimensional data. In this paper, the clustering and visualization capabilities of the SOM, especially in the analysis of textual data, i.e., document collections, are reviewed and further developed. A novel clustering and visualization approach based on the SOM is proposed for the task of text mining. The proposed approach first transforms the document space into a multidimensional vector space by means of document encoding. Afterwards, a growing hierarchical SOM (GHSOM) is trained and used as a baseline structure to automatically produce maps with various levels of detail. Following the GHSOM training, the new projection method, namely the ranked centroid projection (RCP), is applied to project the input vectors to a hierarchy of 2-D output maps. The RCP is used as a data analysis tool as well as a direct interface to the data. In a set of simulations, the proposed approach is applied to an illustrative data set and two real-world scientific document collections to demonstrate its applicability. PMID:18269956

  12. Correcting the beam centroid motion in an induction accelerator and reducing the beam breakup instability

    Science.gov (United States)

    Coleman, J. E.; Ekdahl, C. A.; Moir, D. C.; Sullivan, G. W.; Crawford, M. T.

    2014-09-01

    Axial beam centroid and beam breakup (BBU) measurements were conducted on an 80 ns FWHM, intense relativistic electron bunch with an injected energy of 3.8 MV and current of 2.9 kA. The intense relativistic electron bunch is accelerated and transported through a nested solenoid and ferrite induction core lattice consisting of 64 elements, exiting the accelerator with a nominal energy of 19.8 MeV. The principal objective of these experiments is to quantify the coupling of the beam centroid motion to the BBU instability and validate the theory of this coupling for the first time. Time resolved centroid measurements indicate a reduction in the BBU amplitude, ???, of 19% and a reduction in the BBU growth rate (?) of 4% by reducing beam centroid misalignments ˜50% throughout the accelerator. An investigation into the contribution of the misaligned elements is made. An alignment algorithm is presented in addition to a qualitative comparison of experimental and calculated results which include axial beam centroid oscillations, BBU amplitude, and growth with different dipole steering.

  13. 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…

  14. A novel method for finding non-small cell lung cancer diagnosis biomarkers

    Directory of Open Access Journals (Sweden)

    Tran Quoc-Nam

    2013-01-01

    Full Text Available Abstract Background One of the most common causes of worldwide cancer premature death is non-small cell lung carcinoma (NSCLC with a very low survival rate of 8%-15%. Since patients with an early stage diagnosis can have up to four times the survival rate, discovering cost-effective biological markers that can be used to improve the diagnosis and prognosis of the disease is an important clinical challenge. In the last few years, significant progress has been made to address this challenge with identified biomarkers ranging from 5-gene signatures to 133-gene signatures. However, A typical molecular sub-classification method for lung carcinomas would have a low predictive accuracy of 68%-71% because datasets of gene-expression profiles typically have tens of thousands of genes for just few hundreds of patients. This type of datasets create many technical challenges impacting the accuracy of the diagnostic prediction. Results We discovered that a small set of nine gene-signatures (JAG1, MET, CDH5, ABCC3, DSP, ABCD3, PECAM1, MAPRE2 and PDF5 from the dataset of 12,600 gene-expression profiles of NSCLC acts like an inference basis for NSCLC lung carcinoma and hence can be used as genetic markers. This very small and previously unknown set of biological markers gives an almost perfect predictive accuracy (99.75% for the diagnosis of the disease the sub-type of cancer. Furthermore, we present a novel method that finds genetic markers for sub-classification of NSCLC. We use generalized Lorenz curves and Gini ratios to overcome many challenges arose from datasets of gene-expression profiles. Our method discovers novel genetic changes that occur in lung tumors using gene-expression profiles. Conclusions While proteins encoded by some of these gene-signatures (e.g., JAG1 and MAPRE2 have been showed to involve in the signal transduction of cells and proliferation control of normal cells, specific functions of proteins encoded by other gene-signatures have not yet been determined. Hence, this work opens new questions for structural and molecular biologists about the role of these gene-signatures for the disease.

  15. Velocity Field Statistics in Star-Forming Regions, 1 Centroid Velocity Observations

    CERN Document Server

    Miesch, M S; Bally, J

    1998-01-01

    The probability density functions (pdfs) of molecular line centroid velocity fluctuations and fluctuation differences at different spatial lags are estimated for several nearby molecular clouds with active internal star formation. The data consist of over 75,000 $^{13}$CO line profiles divided among twelve spatially and/or kinematically distinct regions. Although three regions (all in Mon R2) appear nearly Gaussian, the others show strong evidence for non-Gaussian, often nearly exponential, centroid velocity pdfs, possibly with power law contributions in the far tails. Evidence for nearly exponential centroid pdfs in the neutral HI component of the ISM is also presented, based on older optical and radio observations. These results are in striking contrast to pdfs found in isotropic incompressible turbulence experiments and simulations. Furthermore, no evidence is found for the scaling of difference pdf kurtosis with Reynolds number which is seen in incompressible turbulence, and the spatial distribution of hi...

  16. Robustness of regularities for energy centroids in the presence of random interactions

    International Nuclear Information System (INIS)

    In this paper we study energy centroids such as those with fixed spin and isospin and those with fixed irreducible representations for both bosons and fermions, in the presence of random two-body and/or three-body interactions. Our results show that regularities of energy centroids of fixed-spin states reported in earlier works are very robust in these more complicated cases. We suggest that these behaviors might be intrinsic features of quantum many-body systems interacting by random forces

  17. 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.

  18. New Method for Finding a Series of Exact Solutions to Generalized Breaking Soliton Equation

    International Nuclear Information System (INIS)

    In this paper, a new generalized extended tanh-function method is presented for constructing soliton-like, period-form solutions of nonlinear evolution equations (NEEs). This method is more powerful than the extended tanh-function method [Phys. Lett. A 277 (2000) 212] and the modified extended tanh-function method [Phys. Lett. A 285 (2001) 355]. Abundant new families of the exact solutions of Bogoyavlenskii's generalized breaking soliton equation are obtained by using this method and symbolic computation system Maple.

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

    OpenAIRE

    Kohei Arai

    2013-01-01

    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.

  20. Findings, theories and methods in the study of children’s national identifications and national attitudes

    OpenAIRE

    Barrett, Md; Oppenheimer, L.

    2011-01-01

    This paper reviews some of the relevant background findings against which the empirical studies reported in this special issue were designed. Particular attention is given to previous findings on the development of children's national knowledge, national attitudes and national identifications. The paper also reviews five existing theories, which have been proposed to explain the development of children's intergroup attitudes: cognitive-developmental theory (Aboud, 1988, 2008), social identity...

  1. 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.

  2. Finger vein identification using fuzzy-based k-nearest centroid neighbor classifier

    Science.gov (United States)

    Rosdi, Bakhtiar Affendi; Jaafar, Haryati; Ramli, Dzati Athiar

    2015-02-01

    In this paper, a new approach for personal identification using finger vein image is presented. Finger vein is an emerging type of biometrics that attracts attention of researchers in biometrics area. As compared to other biometric traits such as face, fingerprint and iris, finger vein is more secured and hard to counterfeit since the features are inside the human body. So far, most of the researchers focus on how to extract robust features from the captured vein images. Not much research was conducted on the classification of the extracted features. In this paper, a new classifier called fuzzy-based k-nearest centroid neighbor (FkNCN) is applied to classify the finger vein image. The proposed FkNCN employs a surrounding rule to obtain the k-nearest centroid neighbors based on the spatial distributions of the training images and their distance to the test image. Then, the fuzzy membership function is utilized to assign the test image to the class which is frequently represented by the k-nearest centroid neighbors. Experimental evaluation using our own database which was collected from 492 fingers shows that the proposed FkNCN has better performance than the k-nearest neighbor, k-nearest-centroid neighbor and fuzzy-based-k-nearest neighbor classifiers. This shows that the proposed classifier is able to identify the finger vein image effectively.

  3. Finding out the most used booking methods and targeting marketing channels at specific customer segments : Case: Kemi Tourism Ltd.

    OpenAIRE

    Tyta?rniemi, Niina; Hiltunen, Emma-lotta

    2014-01-01

    This study is assigned by Kemi Tourism Ltd. The objective of this thesis research is to find out the most frequently used booking methods used by the customers in different countries and target the assignor’s marketing channels at specific customer segments. The methods used are both quantitative and qualitative research, but the main focus is on the quantitative method. We utilized the Travius booking system when collecting the required information and statistics. We have used literat...

  4. High-sensitivity fiber Bragg grating transverse force sensor based on centroid measurement of polarization-dependent loss

    International Nuclear Information System (INIS)

    The transverse force measurement by virtue of 'stress-induced birefringence effects' of a fiber Bragg grating (FBG) written in a standard telecom single-mode fiber is attractive in the field of internal strain sensing in materials and structures. However, the measurement suffers from the drawback of low transverse force sensitivity of the FBG. In this paper, we propose utilizing the centroid information of the polarization-dependent loss (PDL) evolution of FBG for transverse force measurements. The evolution of the PDL with wavelength for the transmitted signals with respect to transverse force was analyzed and numerically simulated. Experiments were carried out to verify the reasonability and feasibility of the measurement method. Good agreement between experimental results and numerical simulations has been obtained

  5. Finding ultracool brown dwarfs with MegaCam on CFHT: method and first results

    Science.gov (United States)

    Delorme, P.; Willott, C. J.; Forveille, T.; Delfosse, X.; Reylé, C.; Bertin, E.; Albert, L.; Artigau, E.; Robin, A. C.; Allard, F.; Doyon, R.; Hill, G. J.

    2008-06-01

    Aims: We present the first results of a wide field survey for cool brown dwarfs with the MegaCam camera on the CFHT telescope, the Canada-France Brown Dwarf Survey, hereafter CFBDS. Our objectives are to find ultracool brown dwarfs and to constrain the field-brown dwarf mass function thanks to a larger sample of L and T dwarfs. Methods: We identify candidates in CFHT/MegaCam i' and z' images using optimised psf-fitting within Source Extractor, and follow them up with pointed near-infrared imaging on several telescopes. Results: We have so far analysed over 350 square degrees and found 770 brown dwarf candidates brighter than z'_AB=22.5. We currently have J-band photometry for 220 of these candidates, which confirms 37% as potential L or T dwarfs. Some are among the reddest and farthest brown dwarfs currently known, including an independent identification of the recently published ULAS J003402.77-005206.7 and the discovery of a second brown dwarf later than T8, CFBDS J005910.83-011401.3. Infrared spectra of three T dwarf candidates confirm their nature, and validate the selection process. Conclusions: The completed survey will discover ~100 T dwarfs and ~500 L dwarfs or M dwarfs later than M8, approximately doubling the number of currently known brown dwarfs. The resulting sample will have a very well-defined selection function, and will therefore produce a very clean luminosity function. Based on observations obtained with MegaPrime/MegaCam, a joint project of CFHT and CEA/DAPNIA, at the Canada-France-Hawaii Telescope (CFHT) which is operated by the National Research Council (NRC) of Canada, the Institut National des Sciences de l'Univers of the Centre National de la Recherche Scientifique (CNRS) of France, and the University of Hawaii. This work is based in part on data products produced at TERAPIX and the Canadian Astronomy Data Centre as part of the Canada-France-Hawaii Telescope Legacy Survey, a collaborative project of NRC and CNRS. Based on observations made with the ESO New Technology Telescope at the La Silla Observatory under programme ID 76.C-0540(A), 77.C-0594, 77.A-0707, 78.A-0651, 78.C-0629 and 79.A-0663. Based on observations obtained at the Gemini Observatory, which is operated by the Association of Universities for Research in Astronomy, Inc., under a cooperative agreement with the NSF on behalf of the Gemini partnership: the National Science Foundation (United States), the Science and Technology Facilities Council (United Kingdom), the National Research Council (Canada), CONICYT (Chile), the Australian Research Council (Australia), CNPq (Brazil) and CONICET (Argentina). Based on observations with the Kitt Peak National Observatory, National Optical Astronomy Observatory, which is operated by the Association of Universities for Research in Astronomy, Inc. (AURA) under cooperative agreement with the National Science Foundation. Based on observations made with the Nordic Optical Telescope, operated on the island of La Palma jointly by Denmark, Finland, Iceland, Norway, and Sweden, in the Spanish Observatorio del Roque de los Muchachos of the Instituto de Astrofisica de Canarias. This paper includes data taken at The McDonald Observatory of The University of Texas at Austin.

  6. 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...

  7. A general method for finding extremal states of Hamiltonian dynamical systems, with applications to perfect fluids

    OpenAIRE

    Shepherd, Theodore G.

    1990-01-01

    In addition to the Hamiltonian functional itself, non-canonical Hamiltonian dynamical systems generally possess integral invariants known as ‘Casimir functionals’. In the case of the Euler equations for a perfect fluid, the Casimir functionals correspond to the vortex topology, whose invariance derives from the particle-relabelling symmetry of the underlying Lagrangian equations of motion. In a recent paper, Vallis, Carnevale & Young (1989) have presented algorithms for finding steady sta...

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

    DEFF Research Database (Denmark)

    Ra, Koy; Pichdara, Lonn

    2011-01-01

    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.

  9. 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.

  10. Implementation of Multi-Centroid Moment Invariants in Thermal-Based Face Identification System

    Directory of Open Access Journals (Sweden)

    Khairul H. Abas

    2010-01-01

    Full Text Available Problem statement: Current paramount methods and approaches in face identification field rely on facial characteristics; such as location of eyes, length of nose and mouth, regardless the type of medium used to acquire the facial images. The visibility of these facial characteristics varies significantly with environmental factors (e.g., lighting elements. Various researches have been devoted to develop methodologies for addressing these problems. Despite the overwhelming effort to overcome these problems, the current framework of face identification research has a conceivable weakness due to its very nature. Approach: In this study, we presented a novel framework for face identification based on thermal information extracted from facial images acquired within the thermal spectrum. The motivation initiating to conduct this research was to engage in extracting significant facial characteristics from the acquired thermal information, which differs from current facial characteristics that are visible over the skin. Primarily, we proposed a non-holistic analysis approach by decomposing the input image into several input images via multiple threshold method (3 threshold values. This allowed us to analyze the thermal information given within a specific thermal range. Then, the first moment invariant, I1, from Hus classical moment invariants were computed and extracted (with respect to centroid point obtained from frontal shot source images which constituted the feature database. For each subject, we used one (frontal shot registered image with two and four test images (left, mid left, right and mid right. This approach employs minimum distance measurement method for classification purposes. Results: We had conducted experiments on the IRIS IR facial dataset with encouraging results of 95% of correct identification rate for test to registered image ratio of 2:1 and 92.5% of correct identification rate for test to registered image ratio of 4:1. Conclusion: The obtained results demonstrated the high capability of Hus classical moment invariants as a feature in thermal based face identification and introduce new ways for classical methods to further be utilized in theoretical and empirical research in the area.

  11. An Easy Method for Finding the Scattering Coefficients of Quantum Graphs and Some Applications

    Science.gov (United States)

    Cottrell, Seth

    2015-03-01

    Quantum walks are roughly analogous to classical random walks, and like classical walks they have been used to find new (quantum) algorithms. When studying the behavior of large graphs or combinations of graphs it has often been useful to find the response of a subgraph to signals of different frequencies. In this talk I'll be presenting a simple technique for quickly finding the scattering coefficients of any quantum graph. This is done by imitating the scattering states using normalizable states on a modified version of the graph. These scattering coefficients can be expressed entirely in terms of the characteristic polynomial of the graph's time-step operator. With these coefficients in hand we can replace an entire subgraph with a single vertex whose behavior is frequency dependent. This gives us a powerful set of tools for rapidly understanding the behavior of more complex structures. Time permitting, I will apply these tools to several types of graphs (star, complete, tree) demonstrating how we can gain information about the structure of these graphs by bouncing signals off of them, describing the limitations on what information cannot be accessed, and even show how to construct some computations using quantum walks that can be run in faster than classical time.

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

    Scientific Electronic Library Online (English)

    Pere, Riera; Joan, Mogas.

    2004-06-01

    Full Text Available A declaração de preferências corresponde ao método mais comum para estimar o valor social das florestas ou dos seus atributos. Este artigo ilustra o uso deste método para estimar o valor de algumas funções recreativas das florestas mediterrâneas, assim como do sequestro de CO2 e da prevenção da eros [...] ão do solo. Analisa também os resultados de aproximações de ordenação contingente no âmbito de métodos que envolvem a declaração de preferências. Abstract in english 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 ero [...] sion prevention. It also compares the results from a contingent ranking and a choice experiment method application.

  13. A method for finding solutions of the Hermitian theory of relativity which depend on three coordinates

    International Nuclear Information System (INIS)

    A method is presented, which can generate solutions of the Hermitian theory of relativity from known solutions of the general theory of relativity, when the latter depend on three coordinates and are invariant under reversal of the fourth one. (author)

  14. Infant feeding experiences among teen mothers in North Carolina: Findings from a mixed-methods study

    OpenAIRE

    Samandari Ghazaleh; Wilson Ellen K; Tucker Christine M

    2011-01-01

    Abstract Background Adolescent mothers in the U.S. are much less likely to initiate breastfeeding than older mothers, and teens who do initiate breastfeeding tend to breastfeed for shorter durations. The purpose of this mixed-methods study is to investigate breastfeeding practices, barriers and facilitators among adolescent mothers ages 17 and younger. Methods Quantitative descriptive analyses are conducted using data from the North Carolina Pregnancy Risk Assessment Monitoring System (PRAMS)...

  15. Finding confidence limits on population growth rates: bootstrap and analytic methods.

    Science.gov (United States)

    Picard, Nicolas; Chagneau, Pierrette; Mortier, Frédéric; Bar-Hen, Avner

    2009-05-01

    When predicting population dynamics, the value of the prediction is not enough and should be accompanied by a confidence interval that integrates the whole chain of errors, from observations to predictions via the estimates of the parameters of the model. Matrix models are often used to predict the dynamics of age- or size-structured populations. Their parameters are vital rates. This study aims (1) at assessing the impact of the variability of observations on vital rates, and then on model's predictions, and (2) at comparing three methods for computing confidence intervals for values predicted from the models. The first method is the bootstrap. The second method is analytic and approximates the standard error of predictions by their asymptotic variance as the sample size tends to infinity. The third method combines use of the bootstrap to estimate the standard errors of vital rates with the analytical method to then estimate the errors of predictions from the model. Computations are done for an Usher matrix models that predicts the asymptotic (as time goes to infinity) stock recovery rate for three timber species in French Guiana. Little difference is found between the hybrid and the analytic method. Their estimates of bias and standard error converge towards the bootstrap estimates when the error on vital rates becomes small enough, which corresponds in the present case to a number of observations greater than 5000 trees. PMID:19249319

  16. Finding a compromise between chemical and radiological risk assessment methods for mixed waste sites

    International Nuclear Information System (INIS)

    The purpose of this paper is to (1) outline the fundamental similarities and differences between the presently accepted radiological and chemical risk assessment methods, (2) examine the significant differences in analytical results and decision making that can result if either is used to the exclusion of the other and (3) to suggest a hybrid method that utilizes the strong points of each to arrive at a balanced contaminant impact data base for decision making. The approach taken to facilitate these comparisons is to quantitatively assess the collective risk at a simplified site, contaminated with a short list of chemicals and radionuclides. The site is assessed first using exclusively the suggested Superfund toxic chemical methodology for both chemicals and radionuclides, followed by the same analysis using accepted radiological methods for both contaminant categories. Both the methods and the results of these calculations are compared and contrasted. Logical mitigation decisions that might result from each set of calculations are examined. The same site is finally analyzed using a method that incorporates the best of both of the previously used methods and the results are analyzed on the basis of the decision-making utility of the results. Conclusions are drawn relative to several topics or prime importance. These are: acceptable risk bases, key assumptions, statistical inputs, prioritizing contaminants, environmental models, cumulative risk, and risk assessments fo, cumulative risk, and risk assessments for non-human receptors

  17. 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.

  18. Nondestructive Testing Method for Finding out the Defects in a Composite Liner

    Directory of Open Access Journals (Sweden)

    C. Muralidhar

    1999-10-01

    Full Text Available A composite liner of carbon phenolic has been inspected by ultrasonic, X-ray radiography andX-ray computed tomography (CT to find defects like delaminations, debonds, voids, foreign inclusions, etc.The geometry, detection of multiple defects and porosity of the liner make ultrasonic testing (pulse-echo anddrycoupling difficult for inspection. X-ray radiography being a non-contact technique finds multiple defectsbut compresses the structural information of 3-D volume into a 2-D image and interferes with overlyingand underlying areas of the object. X-ray CT generates an image of a thin and cross-sectional slice ofan object. R e linear attenuation coefficients in terms of Hounsfield values have been measured, comparedand correlated with CT images at the contrasts observed. 3-D images can be generated by stacking2-D cross-sectional images of the slices. These 3-D images can be cut at any angle of choice for mappingthe extent of delaminated/debonded areas. This type of information is difficult to obtain with conventionalnon-destructive testing techniques.

  19. The Findings from the OECD/NEA/CSNI UMS (Uncertainty Method Study)

    International Nuclear Information System (INIS)

    Within licensing procedures there is the incentive to replace the conservative requirements for code application by a 'best estimate' concept supplemented by an uncertainty analysis to account for predictive uncertainties of code results. Methods have been developed to quantify these uncertainties. The Uncertainty Methods Study (UMS) Group, following a mandate from CSNI (Committee on the Safety of Nuclear Installations) of OECD/NEA (Organization for Economic Cooperation and Development / Nuclear Energy Agency), has compared five methods for calculating the uncertainty in the predictions of advanced 'best estimate' thermal-hydraulic codes. Most of the methods identify and combine input uncertainties. The major differences between the predictions of the methods came from the choice of uncertain parameters and the quantification of the input uncertainties, i.e. the wideness of the uncertainty ranges. Therefore, suitable experimental and analytical information has to be selected to specify these uncertainty ranges or distributions. After the closure of the Uncertainty Method Study (UMS) and after the report was issued comparison calculations of experiment LSTF-SB-CL-18 were performed by University of Pisa using different versions of the RELAP 5 code. It turned out that the version used by two of the participants calculated a 170 K higher peak clad temperature compared with other versions using the same input deck. This may contribute to the differences of the upper limit of the uncertainty ranges. A 'bifurcation' analysis was also performed by the same research group also providing another way of interpreting the high temperature peak calculated by two of the participants. (authors)

  20. 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

  1. 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…

  2. A systematic method of finding linearizing transformations for nonlinear ordinary differential equations: II. Extension to coupled ODEs

    CERN Document Server

    Chandrasekar, V K; Lakshmanan, M

    2012-01-01

    In this second paper on the method of deriving linearizing transformations for nonlinear ODEs, we extend the method to a set of two coupled second order nonlinear ODEs. We show that besides the conventional point, Sundman and generalized linearizing transformations one can also find a large class of mixed or hybrid type linearizing transformations like point-Sundman, point-generalized linearizing transformation and Sundman-generalized linearizing transformation in coupled second order ODEs using the integrals of motion. We propose suitable algorithms to identify all these transformations (with maximal in number) in a straightforward manner. We illustrate the method of deriving each one of the linearizing transformations with a suitable example.

  3. Accuracy of standard measures of family planning service quality: findings from the simulated client method.

    Science.gov (United States)

    Tumlinson, Katherine; Speizer, Ilene S; Curtis, Siân L; Pence, Brian W

    2014-12-01

    In the field of international family planning, quality of care as a reproductive right is widely endorsed, yet we lack validated data-collection instruments that can accurately assess quality in terms of its public health importance. This study, conducted within 19 public and private facilities in Kisumu, Kenya, used the simulated client method to test the validity of three standard data-collection instruments used in large-scale facility surveys: provider interviews, client interviews, and observation of client-provider interactions. Results found low specificity and low positive predictive values in each of the three instruments for a number of quality indicators, suggesting that the quality of care provided may be overestimated by traditional methods of measurement. Revised approaches to measuring family planning service quality may be needed to ensure accurate assessment of programs and to better inform quality-improvement interventions. PMID:25469929

  4. 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

  5. Validity of Standard Measures of Family Planning Service Quality: Findings from the Simulated Client Method

    OpenAIRE

    Tumlinson, Katherine; Speizer, Ilene S.; Curtis, Sian L.; Pence, Brian W.

    2014-01-01

    Despite widespread endorsement within the field of international family planning regarding the importance of quality of care as a reproductive right, the field has yet to develop validated data collection instruments to accurately assess quality in terms of its public health importance. This study, conducted among 19 higher volume public and private facilities in Kisumu, Kenya, used the simulated client method to test the validity of three standard data collection instruments included in larg...

  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. Finding a Fox: An Evaluation of Survey Methods to Estimate Abundance of a Small Desert Carnivore

    OpenAIRE

    Dempsey, Steven J.; Gese, Eric M.; Kluever, Bryan M.

    2014-01-01

    The status of many carnivore species is a growing concern for wildlife agencies, conservation organizations, and the general public. Historically, kit foxes (Vulpes macrotis) were classified as abundant and distributed in the desert and semi-arid regions of southwestern North America, but is now considered rare throughout its range. Survey methods have been evaluated for kit foxes, but often in populations where abundance is high and there is little consensus on which technique is best to mon...

  9. 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, ...

  10. FINDING CRITICAL BUCKLING LOAD OF RECTANGULAR PLATE USING INTEGRATED FORCE METHOD

    Directory of Open Access Journals (Sweden)

    S. C. Patodi

    2012-11-01

    Full Text Available A method which couples equilibrium equations and compatibility conditions that are developed based on equilibrium equations by using a systematic concatenation procedure is proposed here for the plate buckling analysis. A RECT_9F_12D plate bending element having 9 force unknowns and 12 displacement degrees of freedom is used with the necessary matrix formulation based on the Integrated Force Method (IFM. The geometric stiffness matrix required for buckling analysis is explicitly derived. Matlab software is used to develop compatibility conditions whereas other calculations are carried out in a program developed in VB.NET. A rectangular plate under uniaxial loading is analysed under 7 different boundary conditions. A case of biaxial loading of simply supported plate with loading ratio equals to one is also attempted using the proposed formulation. Results are obtained by considering either 2 x 2 discretization of quarter plate or 4 x 2 discretization of half plate depending upon the type of symmetry available based on support conditions. Results are compared with the available classical solutions to demonstrate the effectiveness of the proposed method; a good agreement is indicated.

  11. Artificial neural networks for centroiding elongated spots in Shack-Hartmann wavefront sensors

    CERN Document Server

    Mello, A T; Guzman, D; Guesalaga, A

    2014-01-01

    The use of Adaptive Optics in Extremely Large Telescopes brings new challenges, one of which is the treatment of Shack-Hartmann Wavefront sensors images. When using this type of sensors in conjunction with laser guide stars for sampling the pupil of telescopes with 30+ m in diameter, it is necessary to compute the centroid of elongated spots, whose elongation angle and aspect ratio are changing across the telescope pupil. Existing techniques such as Matched Filter have been considered as the best technique to compute the centroid of elongated spots, however they are not good at coping with the effect of a variation in the Sodium profile. In this work we propose a new technique using artificial neural networks, which take advantage of the neural network's ability to cope with changing conditions, outperforming existing techniques in this context. We have developed comprehensive simulations to explore this technique and compare it with existing algorithms.

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

    OpenAIRE

    Swarnalatha, P.; Tripathy, B. K.

    2012-01-01

    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 Techn...

  13. Finding ultracool brown dwarfs with MegaCam on CFHT: method and first results

    CERN Document Server

    Delorme, Philippe; Forveille, Thierry; Delfosse, Xavier; Reylé, Céline; Bertin, Emmanuel; Albert, Loic; Artigau, Etienne; Robin, Annie C; Allard, France; Doyon, Rene; Hill, Gary J

    2008-01-01

    We present the first results of a wide field survey for cool brown dwarfs with the MegaCam camera on the CFHT telescope, the Canada-France Brown Dwarf Survey, hereafter CFBDS. Our objectives are to find ultracool brown dwarfs and to constrain the field-brown dwarf mass function thanks to a larger sample of L and T dwarfs. We identify candidates in CFHT/MegaCam i' and z' images using optimised psf-fitting within Source Extractor, and follow them up with pointed near-infrared imaging on several telescopes. We have so far analysed over 350 square degrees and found 770 brown dwarf candidates brighter than z'{AB}=22.5. We currently have J-band photometry for 220 of these candidates, which confirms 37% as potential L or T dwarfs. Some are among the reddest and farthest brown dwarfs currently known, including an independent identification of the recently published ULAS J003402.77-005206.7 and the discovery of a second brown dwarf later than T8, CFBDS J005910.83-011401.3. Infrared spectra of three T dwarf candidates ...

  14. 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...

  15. Inclusion of inversion symmetry in centroid molecular dynamics: A possible avenue to recover quantum coherence

    International Nuclear Information System (INIS)

    Inversion symmetry is included in the operator formulation of the centroid molecular dynamics (CMD). This work involves the development of a symmetry-adapted CMD (SA-CMD), here particularly for symmetrization and antisymmetrization projections. A symmetry-adapted quasidensity operator, as defined by Blinov and Roy [J. Chem. Phys. 115, 7822 (2001)], is employed to obtain the centroid representation of quantum mechanical operators. Numerical examples are given for a single particle confined to one-dimensional symmetric quartic and symmetric double-well potentials. Two SA-CMD simulations are performed separately for both projections, and centroid position autocorrelation functions are obtained. For each projection, the quality of the approximation as well as the accuracy are similar to those of regular CMD. It is shown that individual trajectories from two separate SA-CMD simulations can be properly combined to recover trajectories for Boltzmann statistics. Position autocorrelation functions are compared to the exact quantum mechanical ones. This explicit account of inversion symmetry provides a qualitative improvement on the conventional CMD approach and allows the recovery of some quantum coherence

  16. Centroiding algorithms for high speed crossed-strip readout of microchannel plate detectors

    International Nuclear Information System (INIS)

    Imaging microchannel plate (MCP) detectors with cross-strip (XS) readout anodes require centroiding algorithms to determine the location of the amplified charge cloud from the incident radiation, be it photon or particle. We have developed a massively parallel XS readout electronic system that employs an amplifier and ADC for each strip and uses this digital data to calculate the centroid of each event in real time using a field programmable gate array (FPGA). Doing the calculations in real time in the front end electronics using an FPGA enables a much higher input event rate, nearly two orders of magnitude faster by avoiding the bandwidth limitations of the raw data transfer to a computer. We report on our detailed efforts to optimize the algorithms used on both 18 and 40 mm diameter XS MCP detector with strip pitch of 640 ?m and readout with multiple 32 channel 'Preshape32' ASIC amplifiers (developed at Rutherford Appleton Laboratory). Each strip electrode is continuously digitized to 12 bits at 50 MHz with all 64 digital channels (128 for the 40 mm detector) transferred to a Xilinx Virtex 5 FPGA. We describe how events are detected in the continuous data stream and then multiplexed into firmware modules that spatially and temporally filter and weight the input after applying offset and gain corrections. We will contrast a windowed 'center of gravity' algorithm to a convolution with a special centroiding kernel in terms of resolution and distortion and show resultsesolution and distortion and show results with1 MHz.

  17. 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...

  18. 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.

  19. Finding the rarest objects in the universe: A new, efficient method for discovering BL Lacertae objects

    Science.gov (United States)

    Stocke, John; Perlman, Eric; Granados, Arno; Schachter, Jonathan; Elvis, Martin; Urry, Meg; Impey, Chris; Smith, Paul

    1993-01-01

    We present a new, efficient method for discovering new BL Lac Objects based upon the results of the Einstein Extended Medium Sensitivity Survey (EMSS). We have found that all x-ray selected BL Lacs are radio emitters, and further, that in a 'color-color' diagram (radio/optical and optical/x-ray) the BL Lac Objects occupy an area distinct from both radio loud quasars and the radio quiet QSOs and Seyferts which dominate x-ray selected samples. After obtaining radio counterparts via VLA 'snapshot' observations of a large sample of unidentified x-ray sources, the list of candidates is reduced. These candidates then can be confirmed with optical spectroscopy and/or polarimetry. Since greater than 70 percent of these sources are expected to be BL Lacs, the optical observations are very efficient. We have tested this method using unidentified sources found in the Einstein Slew Survey. The 162 Slew Survey x-ray source positions were observed with the VLA in a mixed B/C configuration at 6 cm resulting in 60 detections within 1.5 position error circle radii. These x-ray/optical/radio sources were then plotted, and 40 BL Lac candidates were identified. To date, 10 candidates have been spectroscopically observed resulting in 10 new BL Lac objects! Radio flux, optical magnitude, and polarization statistics (obtained in white light with the Steward Observatory 2.3 m CCD polarimeter) for each are given.

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

    Directory of Open Access Journals (Sweden)

    RENÉ T. PROYER

    2006-12-01

    Full Text Available 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. Therefore, a nonverbal test was used in this study together with two questionnaires. Additionally, tests for general intelligence, verbal, numeric, and spatial ability, and memory were used. A sample of N = 138 persons was tested in a computerized setting. Results indicate that there is a positive relation between Realistic and Investigative interests and spatial ability. This result was found for both the questionnaires as well as the nonverbal test. Therefore, it can be assumed that this relation is stable for different assessment methods. The data is discussed with respect to current literature.

  1. 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.

  2. Is dark matter present in NGC4736? An iterative spectral method for finding mass distribution in spiral galaxies

    CERN Document Server

    Bratek, L; Kutschera, M; Bratek, Lukasz; Jalocha, Joanna; Kutschera, Marek

    2006-01-01

    We present Iterative Spectral Method of reconstructing mass distribution in spiral galaxies in an infinitely thin axial symmetric disk approximation. The method, without extra assumptions and free parameters, overcomes all problems encountered in standard use of disk model and utilises only information that is available observationally. As an example we apply the method to the ringed Sab-type galaxy NGC4736 that breaks sphericity condition at larger radii. We find mass distribution in NGC4736 that agrees perfectly with its high resolution rotation curve (high resolution, however, is not a must in our method). Given the distribution one finds rotational velocity which is the same as the observed rotation curve (!). The obtained surface mass density is consistent with the I-band luminosity profile (M/L_I=0.7 in Solar units) and with the amount of hydrogen observed in outermost regions where rotation curve is not measured. In the framework of Newtonian gravitation, these findings put in question the presence of ...

  3. Glucose metabolism following human traumatic brain injury: methods of assessment and pathophysiological findings.

    Science.gov (United States)

    Jalloh, Ibrahim; Carpenter, Keri L H; Helmy, Adel; Carpenter, T Adrian; Menon, David K; Hutchinson, Peter J

    2015-06-01

    The pathophysiology of traumatic brain (TBI) injury involves changes to glucose uptake into the brain and its subsequent metabolism. We review the methods used to study cerebral glucose metabolism with a focus on those used in clinical TBI studies. Arterio-venous measurements provide a global measure of glucose uptake into the brain. Microdialysis allows the in vivo sampling of brain extracellular fluid and is well suited to the longitudinal assessment of metabolism after TBI in the clinical setting. A recent novel development is the use of microdialysis to deliver glucose and other energy substrates labelled with carbon-13, which allows the metabolism of glucose and other substrates to be tracked. Positron emission tomography and magnetic resonance spectroscopy allow regional differences in metabolism to be assessed. We summarise the data published from these techniques and review their potential uses in the clinical setting. PMID:25413449

  4. Combined Calibration Method and its Realization for Direction Finding Antenna Systems with Patch Antennas

    Directory of Open Access Journals (Sweden)

    R. Seller

    2007-09-01

    Full Text Available A novel radio channel compensation method aiming to give optimal calibration for microstrip antenna array systems is presented in this paper, realized for an actual DOA measurement antenna system using microstrip antennas to sample the electromagnetic field, operating at 4.5GHz. This new approach considers mismatch between antennas and channel RF ports, channel transmission inequalities, and also decreases the effects of multipath propagation components of calibration reference signals by placing the calibration reference signal feeding network on the microstrip antenna array bearer, directly beside the antenna patches. It is combined with orthogonal spread spectrum calibration signal utility for continuous uninterrupted measurements. The spread spectrum calibration signal is orthogonal to the continuous wave (CW signal to be measured, therefore, the 2 signals can be separated in the receiver, enabling them to be present simultaneously. DOA measurement results are shown, measured with the realized integrated microstrip patch antenna array with calibration network hardware.

  5. 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.)

  6. A proposed non-intrusive method for finding coefficients of slip and molecular reflectivity in microgravity

    Science.gov (United States)

    Noever, D. A.; Rosenberger, F. E.

    1989-01-01

    A proposed experimental program to look at a series of vapor transport properties measured along solid and liquid surfaces is described. The research objectives proposed are: (1) with accuracy otherwise unobtainable on ground, to determine the coefficient of slip measured between gases and the surfaces of liquids and solids; (2) for the first time, to classify and tabulate dominant surface effects found for a variety of solids, particularly those crystalized by vapor transport; and (3) to extend understanding of settling rates predicted for cosmic dust and condensed vapor falling through planetary atmospheres. The method used to obtain these objectives, has aided, to an order of magnitude, understanding of various liquid-gas interfaces such as oil and water. But to date, no similar characterization has proved successful for solids or liquids of uncertain densities. Likewise, no data exist in either ground-based research or as part of a microgravity program that, when collected with the high accuracy expected in low gravity, could definitely settle outstanding questions in kinetic theory, molecular dynamics, and cosmic physics.

  7. Interprofessional mental health training in rural primary care: findings from a mixed methods study.

    Science.gov (United States)

    Heath, Olga; Church, Elizabeth; Curran, Vernon; Hollett, Ann; Cornish, Peter; Callanan, Terrence; Bethune, Cheri; Younghusband, Lynda

    2015-05-01

    The benefits of interprofessional care in providing mental health services have been widely recognized, particularly in rural communities where access to health services is limited. There continues to be a need for more continuing interprofessional education in mental health intervention in rural areas. There have been few reports of rural programs in which mental health content has been combined with training in collaborative practice. The current study used a sequential mixed-method and quasi-experimental design to evaluate the impact of an interprofessional, intersectoral education program designed to enhance collaborative mental health capacity in six rural sites. Quantitative results reveal a significant increase in positive attitudes toward interprofessional mental health care teams and self-reported increases in knowledge and understanding about collaborative mental health care delivery. The analysis of qualitative data collected following completion of the program, reinforced the value of teaching mental health content within the context of collaborative practice and revealed practice changes, including more interprofessional and intersectoral collaboration. This study suggests that imbedding explicit training in collaborative care in content focused continuing professional education for more complex and chronic health issues may increase the likelihood that professionals will work together to effectively meet client needs. PMID:25291262

  8. 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.

  9. Prenatal sex hormone effects on child and adult sex-typed behavior: methods and findings.

    Science.gov (United States)

    Cohen-Bendahan, Celina C C; van de Beek, Cornelieke; Berenbaum, Sheri A

    2005-04-01

    There is now good evidence that human sex-typed behavior is influenced by sex hormones that are present during prenatal development, confirming studies in other mammalian species. Most of the evidence comes from clinical populations, in which prenatal hormone exposure is atypical for a person's sex, but there is increasing evidence from the normal population for the importance of prenatal hormones. In this paper, we briefly review the evidence, focusing attention on the methods used to study behavioral effects of prenatal hormones. We discuss the promises and pitfalls of various types of studies, including those using clinical populations (concentrating on those most commonly studied, congenital adrenal hyperplasia, androgen insensitivity syndrome, ablatio penis, and cloacal exstrophy), direct measures of hormones in the general population (assayed through umbilical cord blood, amniotic fluid, and maternal serum during pregnancy), and indirect measures of hormones in the general population (inferred from intrauterine position and biomarkers such as otoacoustic emissions, finger length ratios, and dermatoglyphic asymmetries). We conclude with suggestions for interpreting and conducting studies of the behavioral effects of prenatal hormones. PMID:15811504

  10. Novel survey method finds dramatic decline of wild cotton-top tamarin population.

    Science.gov (United States)

    Savage, Anne; Thomas, Len; Leighty, Katherine A; Soto, Luis H; Medina, Felix S

    2010-01-01

    The cotton-top tamarin (Saguinus oedipus) is a critically endangered primate, endemic to the tropical forests of Colombia. Population monitoring is essential to evaluate the success of conservation efforts, yet standard survey methods are ineffective because animals flee silently before they are seen. We developed a novel technique that combines the use of playbacks of territorial vocalizations with traditional transect surveys. We used remote sensing to identify potential habitat within the species' historic range, and visited the 27% that we could survey safely. Of this, only 99 km(2) was extant forest, containing an estimated 2,045 animals (95% confidence interval 1,587-2,634). Assuming comparable densities in non-surveyed areas, approximately 7,394 wild cotton-top tamarins remain in Colombia. With 20-30,000 animals exported to the United States in the late 1960s, this must represent a precipitous decline. Habitat destruction and capture for the illegal pet trade are ongoing. Urgent conservation measures are required to prevent extinction in the wild. PMID:20975684

  11. 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.

  12. [Research on the method of stress assessment--from the research findings of 2010].

    Science.gov (United States)

    Natsume, Makoto

    2012-01-01

    The Japanese Society for Occupational Mental Health has conducted research on assessment of the psychological load (i.e., stress) among workers. Investigations were conducted three times, and those were contract research projects assigned by the Ministry of Health, Labour and Welfare. In this project, the author was the primary researcher. In the latest research, a survey utilizing the Live Event Method was performed extensively nationwide; the survey covered 10,494 subjects (including 1,977 females) from all types of industry and occupation. The objective of this research was to reevaluate the Psychological Load Assessment Sheet used as an evaluation basis for the "Certification of workers' compensation related to mental disorders from psychological load." Two previous research investigations, conducted in 2002 and 2006, had suggested the need for such reevaluation. The outcomes revealed that, the longer the monthly overtime working hours, the higher the stress scores (in the range of 0 to 10), and the lower the appearance rate of stress. Subjects who performed 140 hours or more of overtime work per month, which fell under the category of "Extremely Excessive Overtime Work," showed 6.3 points, which was markedly high, and ranked fourth in the survey with 63 assessment items. The category, "Extremely Excessive Overtime Work," includes two working hour ranges, 120 hours or more and 160 hours or more; those working hour ranges were defined in the revision based on the latest research. Monthly overtime work of 120 hours or more, but less than 140 hours, was ranked ninth and scored 6.3 points. Monthly overtime work of 80 hours or more, but less than 100 hours, scored 5.3 points with a frequency of 14.2%. Based on the above results, new assessment items were added to the Psychological Load Assessment Sheet. This paper addresses and studies the issues explained above. PMID:23346811

  13. Healthy bread initiative: methods, findings, and theories--Isfahan Healthy Heart Program.

    Science.gov (United States)

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

    2013-03-01

    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, mainly aiming at making high-fibre, low-salt bread, eliminating the use of baking soda, providing enough rest time for dough before baking (at least one hour), and enough baking time (at least one minute in oven). A workshop was held for volunteer bakers, and a baker-to-baker training protocol under direct supervision was designed for future volunteers. Cereal Organization was persuaded to provide less refined flour that contained more bran. Health messages in support of new breads were disseminated by media and at bakeries by health professionals. Evaluation of the HB Initiative was done using before-after assessments and population surveys. While HB was baked in 1 (0.01%) bakery at baseline, 402 (41%) bakeries in the intervention area joined the HB Initiative in 2009. Soda was completely eliminated and fibre significantly increased from 4 +/- 0.4 g% before study to 12 +/- 0.6 g% after the intervention (p < 0.001). The preparation and baking times remarkably increased. Wastage of bread decreased from 13 +/- 1.8 g% to 2 +/- 0.5 g% and was expressed as the most important advantage of this initiative by consumers. People who lived in Isfahan city consumed whole bread 6 times more than those who lived in reference area Arak (p < 0.001). The HB Initiative managed to add new breads as a healthy choice that were compatible with local dishes and made a model to solve the longstanding problems of bread. It used various health promotion approaches but was best consistent with Beattie's model. PMID:23617204

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

    OpenAIRE

    Jingyan Song; Bin Liang; Tao Zhang; Jun Yang

    2011-01-01

    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 approx...

  15. Distance histogram to centroid as a unique feature to recognize objects

    OpenAIRE

    Arques Corrales, Pilar; Molina Carmona, Rafael; Pujol López, Mar; Rizo Aldeguer, Ramón

    2006-01-01

    The shape of objects plays an essential role among the different aspects of visual information. A 2D silhouette often conveys enough information to allow the correct recognition of the original 3D object. Distance Histogram to Centroid will be used as the unique feature to totally describe an object and to distinguish it from all the other objects in the scene. The proposed system has been proved to be robust to discriminate between classes in a given set of objects The main advantages are...

  16. Are human service agencies ready for disasters? Findings from a mixed-methods needs assessment and planning project.

    Science.gov (United States)

    Hipper, Thomas J; Orr, Ashley; Chernak, Esther

    2015-01-01

    A mixed-methods design was used to assess the current capacity of human service agencies to provide services in a major disaster, identify challenges and successful strategies for providing those services, and formulate specific recommendations for government planners and the nonprofit sector to promote the integration of human service agencies into emergency preparedness and response. A web-based survey was completed by 188 unique human service agencies, 31 semistructured interviews were conducted with human service agency and government leaders from southeastern Pennsylvania and the mid-Atlantic region, and a collaborative planning meeting was held to review the findings and develop systems-based recommendations. Survey results indicated that human service agencies serve the most vulnerable communities during disasters and would welcome integration into preparedness and response plans, but they currently face challenges that include a lack of real-time communication and opportunities for collaborative planning with government partners. Interview findings were grouped according to 5 themes that emerged: capacity, coordination, communication, training, and leadership. This study identified recommendations to assist human service agencies, local health departments, and emergency management agencies as they work to ensure that needed human services are available during disasters, despite the resource challenges that most agencies face. PMID:25813974

  17. 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.

  18. Finding possible transition states of defects in silicon-carbide and alpha-iron using the dimer method

    International Nuclear Information System (INIS)

    Energetic primary recoil atoms from ion implantation or fast neutron irradiation produce isolated point defects and clusters of both vacancies and interstitials. The migration energies and mechanisms for these defects are crucial to successful multiscale modeling of microstructural evolution during ion-implantation, thermal annealing, or under irradiation over long periods of time. The dimer method is employed to search for possible transition states of interstitials and small interstitial clusters in SiC and ?-Fe. The method uses only the first derivatives of the potential energy to find saddle points without knowledge of the final state of the transition. In SiC, the possible migration pathway for the C interstitial is found to consist of the first neighbor jump via a Si site or second neighbor jump, but the relative probability for the second neighbor jump is very low. In ?-Fe, the possible transition states are studied as a function of interstitial cluster size, and the lowest energy barriers correspond to defect migration along directions. However, this paper addresses whether migrating interstitial clusters can thermally change their direction, and the activation energies and corresponding mechanisms for changing the direction of these clusters are determined

  19. 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...

  20. 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.

  1. 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.

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

    Science.gov (United States)

    Joshi, Amit D; Kim, Andre; Lewinger, Juan Pablo; Ulrich, Cornelia M; Potter, John D; Cotterchio, Michelle; Le Marchand, Loic; Stern, Mariana C

    2015-01-01

    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. PMID:25846122

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

    Science.gov (United States)

    Joshi, Amit D; Kim, Andre; Lewinger, Juan Pablo; Ulrich, Cornelia M; Potter, John D; Cotterchio, Michelle; Le Marchand, Loic; Stern, Mariana C

    2015-06-01

    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  cooking practices as possible sources of human carcinogens relevant for CRC risk. PMID:25846122

  4. 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.

  5. A new method for the discovery of the best threshold value for finding positive or negative association rules using Binary Particle Swarm Optimization

    OpenAIRE

    Abdoljabbar Asadi; Azad Shojaei; Salar Saeidi; Salah Karimi; Ebad Karimi

    2012-01-01

    In association rule mining most of former researches have worked on analytic optimizing method , but finding and specifying the advocate initiation limit influences on association rule mining's quality , which still is important hence this research wants to present a new algorithm for optimizing the analytic efficiency improvement including automatic analyze proper amount for initiation. Through former method this task had been performing based on positive rules but regarding that finding the...

  6. 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.

    1984-19-01

    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.

  7. 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

  8. 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.

  9. Rapid Centroids and the Refined Position Accuracy of the Swift Gamma-ray Burst Catalogue

    International Nuclear Information System (INIS)

    The Swift X-ray Telescope autonomously refines the Burst Alert Telescope positions (?1-4' uncertainty) to better than 5 arcsec, within 5 seconds of target acquisition by the observatory for typical bursts. The results of the rapid positioning capability of the XRT are presented here for both known sources and newly discovered GRBs, demonstrating the ability to automatically utilise one of two integration times according to the burst brightness, and to correct the position for alignment offsets caused by the fast pointing performance and variable thermal environment of the satellite as measured by the Telescope Alignment Monitor. We present an evaluation of the position accuracy for both the onboard centroiding software and the ground software for the calibration targets and show that a significant improvement in position accuracy is obtained if the boresight detector position is optimised relative to the spacecraft pointing. Finally, we present an updated catalogue of Swift GRB X-ray positions obtained in Photon Counting Mode using the improved, calibrated boresight

  10. 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.

  11. 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.

  12. 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.

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

    CERN Document Server

    Payami, M

    2002-01-01

    In this work, we have shown the important role of the finite-size correction to the work function in predicting the correct positions of the centroid of excess charge in positively charged simple metal clusters with different $r_s$ values ($2\\le r_s\\le7$). For this purpose, firstly we have calculated the self-consistent Kohn-Sham energies of neutral and singly-ionized clusters with sizes $2\\le N\\le 100$ 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.

  14. 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.

  15. An algebraic method for finding a series of exact solutions to integrable and nonintegrable nonlinear evolution equations

    International Nuclear Information System (INIS)

    An algebraic method is devised to uniformly construct a series of exact solutions for general integrable and nonintegrable nonlinear evolution equations. Compared with most existing tanh methods, the Jacobi function expansion method or other sophisticated methods, the proposed method not only gives new and more general solutions, but also provides a guideline to classify the various types of the solutions according to the values of some parameters. The solutions obtained in this paper include (a) polynomial solutions, (b) exponential solutions, (c) rational solutions, (d) triangular periodic wave solutions, (e) hyperbolic and solitary wave solutions and (f) Jacobi and Weierstrass doubly periodic wave solutions. The efficiency of the method can be demonstrated on a large variety of nonlinear equations such as those considered in this paper, new (2 + 1)-dimensional Calogero-KdV equation, (3 + 1)-dimensional Jimbo-Miwa equation, symmetric regular long wave equation, Drinfel'd-Sokolov-Wilson equation, (2 + 1)-dimensional generalized dispersive long wave equation, double sine-Gordon equation, Calogero-Degasperis-Fokas equation and coupled Schroedinger-Boussinesq equation. In addition, the links among our proposed method, the tanh method, the extended method and the Jacobi function expansion method are also clarified generally

  16. 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.

  17. Neutron radiography with sub-15 {mu}m resolution through event centroiding

    Energy Technology Data Exchange (ETDEWEB)

    Tremsin, Anton S., E-mail: ast@ssl.berkeley.edu [Space Sciences Laboratory, University of California at Berkeley, Berkeley, CA 94720 (United States); McPhate, Jason B.; Vallerga, John V.; Siegmund, Oswald H.W. [Space Sciences Laboratory, University of California at Berkeley, Berkeley, CA 94720 (United States); Bruce Feller, W. [NOVA Scientific, Inc. 10 Picker Road, Sturbridge, MA 01566 (United States); Lehmann, Eberhard; Kaestner, Anders; Boillat, Pierre; Panzner, Tobias; Filges, Uwe [Spallation Neutron Source Division, Paul Scherrer Institute, CH-5232 Villigen (Switzerland)

    2012-10-01

    Conversion of thermal and cold neutrons into a strong {approx}1 ns electron pulse with an absolute neutron detection efficiency as high as 50-70% makes detectors with {sup 10}B-doped Microchannel Plates (MCPs) very attractive for neutron radiography and microtomography applications. The subsequent signal amplification preserves the location of the event within the MCP pore (typically 6-10 {mu}m in diameter), providing the possibility to perform neutron counting with high spatial resolution. Different event centroiding techniques of the charge landing on a patterned anode enable accurate reconstruction of the neutron position, provided the charge footprints do not overlap within the time required for event processing. The new fast 2 Multiplication-Sign 2 Timepix readout with >1.2 kHz frame rates provides the unique possibility to detect neutrons with sub-15 {mu}m resolution at several MHz/cm{sup 2} counting rates. The results of high resolution neutron radiography experiments presented in this paper, demonstrate the sub-15 {mu}m resolution capability of our detection system. The high degree of collimation and cold spectrum of ICON and BOA beamlines combined with the high spatial resolution and detection efficiency of MCP-Timepix detectors are crucial for high contrast neutron radiography and microtomography with high spatial resolution. The next generation of Timepix electronics with sparsified readout should enable counting rates in excess of 10{sup 7} n/cm{sup 2}/s taking full advantage of high beam intensity of present brightest neutron imaging facilities.

  18. Temnothoraxcrasecundus sp. n. - a cryptic Eurocaucasian ant species (Hymenoptera, Formicidae) discovered by Nest Centroid Clustering.

    Science.gov (United States)

    Seifert, Bernhard; Csösz, Sandor

    2015-01-01

    The paper integrates two independent studies of numeric morphology-based alpha-taxonomy of the cryptic ant species Temnothoraxcrassispinus (Karavajev, 1926) and Temnothoraxcrasecundus 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 Temnothoraxcrassispinus and Temnothoraxcrasecundus sp. n. were allocated to different clusters with p = 0.9851 and p = 0.9912 respectively. The type series of the junior synonym Temnothoraxslavonicus (Seifert, 1995) was allocated to the Temnothoraxcrassispinus cluster with p = 0.9927. Temnothoraxcrasecundus sp. n. and Temnothoraxcrassispinus 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 Temnothoraxcrasecundus sp. n. are given. PMID:25685016

  19. The latency information theory revolution, part III: knowledge-unaided power-centroid adaptive radar

    Science.gov (United States)

    Feria, Erlan H.

    2010-04-01

    Knowledge unaided power centroid (KUPC) adaptive radar and its latency information theory (LIT) roots are reviewed in this third paper of a three paper series. LIT is the universal guidance theory for efficient system designs that has inherently surfaced from the confluence of five ideas. They are: 1) The source entropy and channel capacity performance bounds of Shannon's mathematical theory of communication; 2) The latency time (LT) certainty of Einstein's relativity theory; 3) The information space (IS) uncertainty of Heisenberg's quantum physics; 4) The black hole Hawking radiation and its Boltzmann thermodynamics entropy S in SI J/K; and 5) The author's 1978 conjecture of a structural-physical LT-certainty/IS-uncertainty duality for stochastic control. LIT is characterized by a four quadrants revolution. While the first and third quadrants are concerned with the life time of physical signal movers and the life space of physical signal retainers, respectively, the second and fourth quadrants are about the intelligence space of mathematical signal sources and the processing time of mathematical signal processors, respectively. The four quadrants of LIT are assumed to be physically independent with their system design methodologies guided by dualities and performance bounds. Moreover, all the LIT quadrants are bridged by statistical physics, inclusive of a recently discovered time dual for thermodynamics that has been named lingerdynamics. The theoretical and practical relevance of LIT has already been demonstrated using real-world control, physics, biochemistry and the KUPC adaptive radar application that is reviewed in this paper. KUPC adaptive radar is a technique that falls within the fourth quadrant of LIT, and is thus a mathematical signal processing technique whose goal is the efficient detection of moving targets in real-world taxing environments. As is highlighted in this review KUPC adaptive radar is found to come relatively close to the signal to interference plus noise ratio (SINR) radar performance of DARPA's knowledge-aided sensory signal processing expert reasoning (KASSPER) even though it is knowledge unaided.

  20. For a reasoned development of experimental methods in information and communication sciences Some epistemological findings of methodological pluralism

    Directory of Open Access Journals (Sweden)

    Didier COURBET

    2013-07-01

    Full Text Available If multidisciplinarity is necessary, first, for studying the widest possible set of communication phenomena (organizational, in groups, interpersonal, media, computer-mediated communication... and, secondly, for grasping the complexity of the different moments of the same phenomenon of communication (production, content, reception, circulation ..., methodological pluralism is also important. However, French research in communication sciences leaves in the shade a number of phenomena and moments of communication that could be better understood thanks to the experimental method. We will underline that the epistemological issues related to rational use of the experimental method in communication sciences are not negligible: it allows the study of objects that cannot be investigated with other methods and offers the opportunity to build knowledge by the refutation of hypotheses and theoretical propositions. We will clarify some epistemological misunderstandings concerning this method. First, it is actually a method of studying complex systems and communication processes. Secondly, its use is not incompatible with constructivism.

  1. A Method for Finding Solutions of the Hermitian Theory of Relativity which Depend on Three Co-ordinates

    Science.gov (United States)

    Antoci, S.

    A method is presented, which can generate solutions of the Hermitian theory of relativity from known solutions of the general theory of relativity, when the latter depend on three co-ordinates and are invariant under reversal of the fourth one.Translated AbstractEine Methode zum Auffinden von Lösungen der Hermiteschen Relativitätstheorie, die von drei Koordinaten abhängenEs wird eine Methode vorgestellt, nach der Lösungen der Hermiteschen Relativitätstheorie aus bekannten Lösungen der Allgemeinen Relativitätstheorie gewonnen werden können, wenn diese von drei Koordinaten abhängen und bei Umkehrung der vierten invariant bleiben.

  2. Method and circuit for finding the coordinate of the center of a particle track on a scanning automaton

    Energy Technology Data Exchange (ETDEWEB)

    Gusev, Yu.A.

    1975-01-01

    A method is proposed for determining the coordinate of the center of a particle track on a scanning automaton; the technique produces no deadband and is realized using a small number of microcircuits. The electronic circuitry is developed.

  3. K-nearest Neighbour Method of Analysing the ECG Signal (To Find out the Different Disorders Related to Heart)

    OpenAIRE

    S. Jayalalitha; D.Susan; Shalini Kumari; B. Archana

    2014-01-01

    Heart attack is very common thing now-a-days. This results because of many disorders occurring in the heart. These disorders can be found out by analysing the ECG signal. The conventional method of analysing the ECG signal is done by the doctors who are expert in that. So far there is no systematic procedure for analysing the ECG signal. The main goal of this study is to obtain a systematic method of analysing the Electrocardiogram (ECG) from the patient an...

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

    OpenAIRE

    Howel Denise; Mackintosh Joan; White Martin; Moffatt Suzanne

    2006-01-01

    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 ov...

  5. Franck-Condon factors and r-centroids for the B-X bands of 10B18O and 11B18O molecules

    Directory of Open Access Journals (Sweden)

    VOJISLAV BOJOVIC

    2005-05-01

    Full Text Available Frank–Condon factors and r-centroids have been calculated for the B2S+ –X2S+ bands of the 10B18O and 11B18O isotopic molecules assuming that both the B and X states follow a Morse potential curve. The calculated q n'n" values are compared with observed band intensities and the relationship between the r-centroids and the band positions has been determined and is discussed.

  6. The centroid shift of the 5d levels of Ce sup 3 sup + with respect to the 4f levels in ionic crystals, a theoretical investigation

    CERN Document Server

    Andriessen, J; Eijk, C W E

    2002-01-01

    The centroid shifts of the 5d level of Ce sup 3 sup + in BaF sub 2 , LaAlO sub 3 and LaCl sub 3 have been calculated using the ionic cluster approach. By applying configuration interaction as extension of the basic HF-LCAO approach the dynamical polarization contribution to the centroid shift was calculated. This was found to be only successful if basis sets are used optimized for polarization of the anions.

  7. OMERACT 10 sharp symposium: important findings in examination of imaging methods for measurement of joint damage in rheumatoid arthritis

    DEFF Research Database (Denmark)

    Strand, Vibeke; Kingsbury, Sarah R

    2011-01-01

    The Sharp Symposium was held at the Outcome Measures in Rheumatology Clinical Trials 2010 meeting (OMERACT 10) in honor of the late John Sharp, consummate rheumatologist and researcher. The symposium focused on the status of current scoring methods in radiography, magnetic resonance imaging (MRI), and ultrasound (US) in rheumatoid arthritis (RA), as well as on the use of soluble and tissue biomarkers in RA, with the aim of updating recommendations regarding methods for enhanced detection, monitoring, and prediction of joint damage in clinical trials.

  8. A Method for Finding Solutions of the Hermitian Theory of Relativity which Depend on Three Co-ordinates

    OpenAIRE

    Antoci, S.

    2001-01-01

    A method is presented, which can generate solutions of the Hermitian theory of relativity from known solutions of the general theory of relativity, when the latter depend on three co-ordinates and are invariant under reversal of the fourth one.

  9. Assessing the impacts of regional characteristics on the location of manufacturing facilities: A review of recent methods and findings

    Energy Technology Data Exchange (ETDEWEB)

    Calzonetti, F.J. [West Virginia Univ., Morgantown, WV (United States). Dept. of Geology and Geography; Hemphill, R.C. [Argonne National Lab., IL (United States). Environmental Assessment and Information Sciences Div.

    1992-01-01

    This report gives federal agencies background information to help them assess the impacts that siting a nuclear-waste storage facility could have on industries making location decisions in various regions of influence. It reviews two major research methods used to analyze reasons for location choices: economic-based or econometric methods and survey-based factor-ranking methods. It summarizes the results of studies that have used these methods, identifying and ranking factors shown to be important to industries making location decisions throughout the nation and in western states. Neither economic-based nor survey-based studies have shown the public`s perceptions of a region to be an important determinant in the selection of new manufacturing sites, although consideration of the level of amenities is gaining importance in the West. In general, available studies are inconclusive with respect to the extent to which perceptions about hazards play a role in the location of manufacturing facilities in any region of the nation.

  10. Assessing the impacts of regional characteristics on the location of manufacturing facilities: A review of recent methods and findings

    Energy Technology Data Exchange (ETDEWEB)

    Calzonetti, F.J. (West Virginia Univ., Morgantown, WV (United States). Dept. of Geology and Geography); Hemphill, R.C. (Argonne National Lab., IL (United States). Environmental Assessment and Information Sciences Div.)

    1992-01-01

    This report gives federal agencies background information to help them assess the impacts that siting a nuclear-waste storage facility could have on industries making location decisions in various regions of influence. It reviews two major research methods used to analyze reasons for location choices: economic-based or econometric methods and survey-based factor-ranking methods. It summarizes the results of studies that have used these methods, identifying and ranking factors shown to be important to industries making location decisions throughout the nation and in western states. Neither economic-based nor survey-based studies have shown the public's perceptions of a region to be an important determinant in the selection of new manufacturing sites, although consideration of the level of amenities is gaining importance in the West. In general, available studies are inconclusive with respect to the extent to which perceptions about hazards play a role in the location of manufacturing facilities in any region of the nation.

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

    Science.gov (United States)

    Seifert, Bernhard; Csösz, Sandor

    2015-01-01

    Abstract The paper integrates two independent studies of numeric morphology-based alpha-taxonomy of the cryptic ant species Temnothorax crassispinus (Karavajev, 1926) and Temnothorax 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 Temnothorax crassispinus and Temnothorax crasecundus sp. n. were allocated to different clusters with p = 0.9851 and p = 0.9912 respectively. The type series of the junior synonym Temnothorax slavonicus (Seifert, 1995) was allocated to the Temnothorax crassispinus cluster with p = 0.9927. Temnothorax crasecundus sp. n. and Temnothorax 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 Temnothorax crasecundus sp. n. are given. PMID:25685016

  12. 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.

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

    International Nuclear Information System (INIS)

    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)

  14. 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

    2015-06-01

    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

  15. 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.

  16. 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)

  17. Rock Finding

    Science.gov (United States)

    Rommel-Esham, Katie; Constable, Susan D.

    2006-01-01

    In this article, the authors discuss a literature-based activity that helps students discover the importance of making detailed observations. In an inspiring children's classic book, "Everybody Needs a Rock" by Byrd Baylor (1974), the author invites readers to go "rock finding," laying out 10 rules for finding a "perfect" rock. In this way, the…

  18. A new method for the discovery of the best threshold value for finding positive or negative association rules using Binary Particle Swarm Optimization

    Directory of Open Access Journals (Sweden)

    Abdoljabbar Asadi

    2012-11-01

    Full Text Available In association rule mining most of former researches have worked on analytic optimizing method , but finding and specifying the advocate initiation limit influences on association rule mining's quality , which still is important hence this research wants to present a new algorithm for optimizing the analytic efficiency improvement including automatic analyze proper amount for initiation. Through former method this task had been performing based on positive rules but regarding that finding the negative ones were though for administrator, this research's privilege is that the initiation level automatically is analyzed for the first time; also it has high efficiency in large data base. Particle Swarm Optimization is observed for any particle's efficiency and as data turned in binary the advocate amount will be found. Results showed Particle Swarm Optimization could present better initiation level, and enhance the former algorithm's result a lot. Consequence will be comparing with Weka and Apriori.

  19. 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...

  20. 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.

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

    Science.gov (United States)

    Dietrich, Andrea; Fernandez, Thomas V; King, Robert A; State, Matthew W; Tischfield, Jay A; Hoekstra, Pieter J; Heiman, Gary A

    2015-02-01

    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. PMID:24771252

  2. 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.

  3. PERFORMANCE OF SELECTED AGGLOMERATIVE HIERARCHICAL CLUSTERING METHODS

    Directory of Open Access Journals (Sweden)

    Nusa Erman

    2015-01-01

    Full Text Available A broad variety of different methods of agglomerative hierarchical clustering brings along problems how to choose the most appropriate method for the given data. It is well known that some methods outperform others if the analysed data have a specific structure. In the presented study we have observed the behaviour of the centroid, the median (Gower median method, and the average method (unweighted pair-group method with arithmetic mean – UPGMA; average linkage between groups. We have compared them with mostly used methods of hierarchical clustering: the minimum (single linkage clustering, the maximum (complete linkage clustering, the Ward, and the McQuitty (groups method average, weighted pair-group method using arithmetic averages - WPGMA methods. We have applied the comparison of these methods on spherical, ellipsoid, umbrella-like, “core-and-sphere”, ring-like and intertwined three-dimensional data structures. To generate the data and execute the analysis, we have used R statistical software. Results show that all seven methods are successful in finding compact, ball-shaped or ellipsoid structures when they are enough separated. Conversely, all methods except the minimum perform poor on non-homogenous, irregular and elongated ones. Especially challenging is a circular double helix structure; it is being correctly revealed only by the minimum method. We can also confirm formerly published results of other simulation studies, which usually favour average method (besides Ward method in cases when data is assumed to be fairly compact and well separated.

  4. 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

  5. Evidence-informed health policy 1 – Synthesis of findings from a multi-method study of organizations that support the use of research evidence

    Directory of Open Access Journals (Sweden)

    Moynihan Ray

    2008-12-01

    Full Text Available Abstract Background Organizations have been established in many countries and internationally to support the use of research evidence by producing clinical practice guidelines, undertaking health technology assessments, and/or directly supporting the use of research evidence in developing health policy on an international, national, and state or provincial level. Learning from these organizations can reduce the need to 'reinvent the wheel' and inform decisions about how best to organize support for such organizations, particularly in low- and middle-income countries (LMICs. Methods We undertook a multi-method study in three phases – a survey, interviews, and case descriptions that drew on site visits – and in each of the second and third phases we focused on a purposive sample of those involved in the previous phase. We used the seven main recommendations that emerged from the advice offered in the interviews to organize much of the synthesis of findings across phases and methods. We used a constant comparative method to identify themes from across phases and methods. Results Seven recommendations emerged for those involved in establishing or leading organizations that support the use of research evidence in developing health policy: 1 collaborate with other organizations; 2 establish strong links with policymakers and involve stakeholders in the work; 3 be independent and manage conflicts of interest among those involved in the work; 4 build capacity among those working in the organization; 5 use good methods and be transparent in the work; 6 start small, have a clear audience and scope, and address important questions; and 7 be attentive to implementation considerations, even if implementation is not a remit. Four recommendations emerged for the World Health Organization (WHO and other international organizations and networks: 1 support collaborations among organizations; 2 support local adaptation efforts; 3 mobilize support; and 4 create global public goods. Conclusion This synthesis of findings from a multi-method study, along with the more detailed findings from each of the three phases of the study (which are reported in the three following articles in the series, provide a strong basis on which researchers, policymakers, international organizations (and networks like WHO can respond to the growing chorus of voices calling for efforts to support the use of research evidence in developing health policy.

  6. An X-ray method for detecting substructure in galaxy clusters - Application to Perseus, A2256, Centaurus, Coma, and Sersic 40/6

    Science.gov (United States)

    Mohr, Joseph J.; Fabricant, Daniel G.; Geller, Margaret J.

    1993-01-01

    We use the moments of the X-ray surface brightness distribution to constrain the dynamical state of a galaxy cluster. Using X-ray observations from the Einstein Observatory IPC, we measure the first moment FM, the ellipsoidal orientation angle, and the axial ratio at a sequence of radii in the cluster. We argue that a significant variation in the image centroid FM as a function of radius is evidence for a nonequilibrium feature in the intracluster medium (ICM) density distribution. In simple terms, centroid shifts indicate that the center of mass of the ICM varies with radius. This variation is a tracer of continuing dynamical evolution. For each cluster, we evaluate the significance of variations in the centroid of the IPC image by computing the same statistics on an ensemble of simulated cluster images. In producing these simulated images we include X-ray point source emission, telescope vignetting, Poisson noise, and characteristics of the IPC. Application of this new method to five Abell clusters reveals that the core of each one has significant substructure. In addition, we find significant variations in the orientation angle and the axial ratio for several of the clusters.

  7. 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 nrison 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.)

  8. 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.)

  9. Finding Colors

    Science.gov (United States)

    Sciencenter

    2014-08-27

    In this chemistry challenge, learners combine acids and bases in a universal indicator to create five different colors. Using vinegar, washing soda, and Bogen universal indicator, the goal is to find combinations that create red, orange, yellow, green, and blue solutions. Background information explains a little about how acids and bases interact to affect the pH of a solution, and how the indicator changes color based on the pH. Safety notes are included.

  10. Fossil Find

    Science.gov (United States)

    In this classroom activity, middle school students simulate a "dinosaur dig." The activity opens with background information for teachers about fossils. Working in groups, students excavate fossil sites created in advance by the teacher, or other group of students, and try to reconstruct a chicken skeleton. The activity closes with a two-page student worksheet that directs students to diagram the fossil site and includes probing questions to help them decode their findings.

  11. Oscar — Using Byte Pairs to Find File Type and Camera Make of Data Fragments

    Science.gov (United States)

    Karresand, Martin; Shahmehri, Nahid

    Mapping out the contents of fragmented storage media is hard if the file system has been corrupted, especially as the current forensic tools rely on meta information to do their job. If it was possible to find all fragments belonging to a certain file type, it would also be possible to recover a lost file. Such a tool could for example be used in the hunt for child pornography. The Oscar method identifies the file type of data fragments based solely on statistics calculated from their structure. The method does not need any meta data to work. We have previously used the byte frequency distribution and the rate of change between consecutive bytes as basis for the statistics, as well as calculating the 2-gram frequency distribution to create a model of different file types. This paper present a variant of the 2-gram method, in that it uses a dynamic smoothing factor. In this way we take the amount of data used to create the centroid into consideration. A previous experiment on file type identification is extended with .mp3 files reaching a detection rate of 76% with a false positives rate of 0.4%. We also use the method to identify the camera make used to capture a .jpg picture from a fragment of the picture. The result shows that we can clearly separate a picture fragment coming from a Fuji or Olympus cameras from a fragment of a picture of the other camera makes used in our test.

  12. Finding autophagy

    Science.gov (United States)

    Klionsky, Daniel J.

    2013-01-01

    To tell the truth, I find it difficult to work when flying, or even when sitting in an airport for an extended period of time. So, typically I take along a book to read. And when I truly cannot concentrate, for example when a flight is considerably delayed, I have even been known to resort to word puzzles. Depending on the type, they do not require much attention (that is, you can pick up right where you left off after you glance at the flight status screen for the twentieth or so time, even though you know nothing has changed), or effort (although you need to use a pen or pencil, not a keyboard), but nonetheless they can keep your mind somewhat occupied. I even rationalize doing them based on the assumption that they are sharpening my observational/pattern-finding skills. One type of word puzzle that is particularly mindless, but for that very reason I still enjoy in the above circumstances, is a word search; you are given a grid with letters and/or numbers, and a list of “hidden” terms, and you circle them within the grid, crossing them off the list as you go along. I do admit that the categories of terms used in the typical word searches can become rather mundane (breeds of dog, types of food, words that are followed by “stone,” words associated with a famous movie star, words from a particular television show, etc.). Therefore, on one of my last seminar trips I decided to generate my own word search, using the category of autophagy. PMID:23322216

  13. Astrometric Image Centroid Displacements due to Gravitational Microlensing by the Ellis Wormhole

    OpenAIRE

    Toki, Yukiharu; Kitamura, Takao; Asada, Hideki; Abe, Fumio

    2011-01-01

    Continuing work initiated in an earlier publication (Abe, ApJ, 725 (2010) 787), we study the gravitational microlensing effects of the Ellis wormhole in the weak-field limit. First, we find a suitable coordinate transformation, such that the lens equation and analytic expressions of the lensed image positions can become much simpler than the previous ones. Second, we prove that two images always appear for the weak-field lens by the Ellis wormhole. By using these analytic re...

  14. 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

  15. 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 thps 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)

  16. 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; G.R.Sridhar

    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

  17. Analytic continuation average spectrum method for transport in quantum liquids

    Energy Technology Data Exchange (ETDEWEB)

    Kletenik-Edelman, Orly [School of Chemistry, Sackler Faculty of Exact Sciences, Tel Aviv University, Tel Aviv 69978 (Israel); Rabani, Eran, E-mail: rabani@tau.ac.il [School of Chemistry, Sackler Faculty of Exact Sciences, Tel Aviv University, Tel Aviv 69978 (Israel); Reichman, David R. [Department of Chemistry, Columbia University, 3000 Broadway, New York, NY 10027 (United States)

    2010-05-12

    Recently, we have applied the analytic continuation averaged spectrum method (ASM) to calculate collective density fluctuations in quantum liquid . Unlike the maximum entropy (MaxEnt) method, the ASM approach is capable of revealing resolved modes in the dynamic structure factor in agreement with experiments. In this work we further develop the ASM to study single-particle dynamics in quantum liquids with dynamical susceptibilities that are characterized by a smooth spectrum. Surprisingly, we find that for the power spectrum of the velocity autocorrelation function there are pronounced differences in comparison with the MaxEnt approach, even for this simple case of smooth unimodal dynamic response. We show that for liquid para-hydrogen the ASM is closer to the centroid molecular dynamics (CMD) result while for normal liquid helium it agrees better with the quantum mode coupling theory (QMCT) and with the MaxEnt approach.

  18. Analytic continuation average spectrum method for transport in quantum liquids

    International Nuclear Information System (INIS)

    Recently, we have applied the analytic continuation averaged spectrum method (ASM) to calculate collective density fluctuations in quantum liquid . Unlike the maximum entropy (MaxEnt) method, the ASM approach is capable of revealing resolved modes in the dynamic structure factor in agreement with experiments. In this work we further develop the ASM to study single-particle dynamics in quantum liquids with dynamical susceptibilities that are characterized by a smooth spectrum. Surprisingly, we find that for the power spectrum of the velocity autocorrelation function there are pronounced differences in comparison with the MaxEnt approach, even for this simple case of smooth unimodal dynamic response. We show that for liquid para-hydrogen the ASM is closer to the centroid molecular dynamics (CMD) result while for normal liquid helium it agrees better with the quantum mode coupling theory (QMCT) and with the MaxEnt approach.

  19. 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 amenorth 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

  20. Centroid Based Text Clustering

    OpenAIRE

    Priti Maheshwari; Jitendra Agrawal

    2010-01-01

    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 representa...

  1. Radiological findings after gastrectomy

    International Nuclear Information System (INIS)

    In 63 patients after total gastrectomy and reconstruction of the small bowel described by Beal-Longmire, Roux and Tomoda radiological findings were correlated with clinical symptoms. No correlation could be found between clinical symptoms if dumping and oesophagitis caused by reflux on one side and increased length of intestinal transit time, increased diameter of intestinal loops and gastro-oesophageal reflux on the other side. Enlarged blind loops after termino-lateral oesophago-jejunostomy and insufficient ligations (operation technique by Tomoda) were correlated with higher incidence of pains. Patients operated by the method of Beal-Longmire and Roux showed better results than those operated with the method of Tomoda. (orig.)

  2. A sub-ODE method for finding exact solutions of a generalized KdV-mKdV equation with high-order nonlinear terms

    International Nuclear Information System (INIS)

    The bell type solitary wave solution, the kink type solitary wave solution, the algebraic solitary wave solution and the sinusoidal traveling wave solution of a generalized KdV-mKdV equation (GKdV-mKdV) with high-order nonlinear terms are obtained by a subsidiary ordinary differential equation method (sub-ODE method for short). The key ideas of the sub-ODE method are that the traveling wave solutions of a complicated nonlinear wave equation can be constructed by means of the solutions of some simple and solvable ODEs which are called sub-ODEs

  3. A sub-ODE method for finding exact solutions of a generalized KdV-mKdV equation with high-order nonlinear terms

    Energy Technology Data Exchange (ETDEWEB)

    Li Xiangzheng [College of Science, Henan University of Science and Technology, Luoyang 471003 (China)]. E-mail: lylxz@mail.haust.edu.cn; Wang Mingliang [College of Science, Henan University of Science and Technology, Luoyang 471003 (China); Department of Mathematics, Lanzhou University, Lanzhou 730000 (China)

    2007-01-22

    The bell type solitary wave solution, the kink type solitary wave solution, the algebraic solitary wave solution and the sinusoidal traveling wave solution of a generalized KdV-mKdV equation (GKdV-mKdV) with high-order nonlinear terms are obtained by a subsidiary ordinary differential equation method (sub-ODE method for short). The key ideas of the sub-ODE method are that the traveling wave solutions of a complicated nonlinear wave equation can be constructed by means of the solutions of some simple and solvable ODEs which are called sub-ODEs.

  4. A sub-ODE method for finding exact solutions of a generalized KdV mKdV equation with high-order nonlinear terms

    Science.gov (United States)

    Li, Xiangzheng; Wang, Mingliang

    2007-01-01

    The bell type solitary wave solution, the kink type solitary wave solution, the algebraic solitary wave solution and the sinusoidal traveling wave solution of a generalized KdV mKdV equation (GKdV mKdV) with high-order nonlinear terms are obtained by a subsidiary ordinary differential equation method (sub-ODE method for short). The key ideas of the sub-ODE method are that the traveling wave solutions of a complicated nonlinear wave equation can be constructed by means of the solutions of some simple and solvable ODEs which are called sub-ODEs.

  5. 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.

  6. The sub-ODE method for finding exact travelling wave solutions of generalized nonlinear Camassa-Holm, and generalized nonlinear Schroedinger equations

    International Nuclear Information System (INIS)

    With the aid of the ordinary differential equation (ODE) involving an arbitrary positive power of dependent variable proposed by Li and Wang and an indirect F-function method very close to the F-expansion method, we solve the generalized Camassa-Holm equation with fully nonlinear dispersion and fully nonlinear convection C(l,n,p) and the generalized nonlinear Schroedinger equation with nonlinear dispersion GNLS(l,n,p,q). Taking advantage of the new subsidiary ODE, this F-function method is used to map the solutions of C(l,n,p) and GNLS(l,n,p,q) equations to those of that nonlinear ODE. As result, we can successfully obtain in a unified way, many exact solutions

  7. The sub-ODE method for finding exact travelling wave solutions of generalized nonlinear Camassa-Holm, and generalized nonlinear Schroedinger equations

    Energy Technology Data Exchange (ETDEWEB)

    Yomba, Emmanuel [School of Mathematics, University of Minnesota, 127 Vincent Hall, Minneapolis, MN 55455 (United States); Department of Physics, Faculty of Sciences, University of Ngaoundere, PO Box 454, Ngaoundere (Cameroon)], E-mail: yomba@ima.umn.edu

    2008-01-14

    With the aid of the ordinary differential equation (ODE) involving an arbitrary positive power of dependent variable proposed by Li and Wang and an indirect F-function method very close to the F-expansion method, we solve the generalized Camassa-Holm equation with fully nonlinear dispersion and fully nonlinear convection C(l,n,p) and the generalized nonlinear Schroedinger equation with nonlinear dispersion GNLS(l,n,p,q). Taking advantage of the new subsidiary ODE, this F-function method is used to map the solutions of C(l,n,p) and GNLS(l,n,p,q) equations to those of that nonlinear ODE. As result, we can successfully obtain in a unified way, many exact solutions.

  8. The sub-ODE method for finding exact travelling wave solutions of generalized nonlinear Camassa Holm, and generalized nonlinear Schrödinger equations

    Science.gov (United States)

    Yomba, Emmanuel

    2008-01-01

    With the aid of the ordinary differential equation (ODE) involving an arbitrary positive power of dependent variable proposed by Li and Wang and an indirect F-function method very close to the F-expansion method, we solve the generalized Camassa Holm equation with fully nonlinear dispersion and fully nonlinear convection C(l,n,p) and the generalized nonlinear Schrödinger equation with nonlinear dispersion GNLS(l,n,p,q). Taking advantage of the new subsidiary ODE, this F-function method is used to map the solutions of C(l,n,p) and GNLS(l,n,p,q) equations to those of that nonlinear ODE. As result, we can successfully obtain in a unified way, many exact solutions.

  9. A Near-Infrared Variant of the Barnes-Evans Method For Finding Cepheid Distances Calibrated with High-Precision Angular Diameters

    OpenAIRE

    Welch, D. L.

    1994-01-01

    The advantages of a near-infrared variant of the Barnes-Evans method for estimating distances to Cepheid variables are described and quantified. A surface brightness-color relation for $K$ photometry and the $(V-K)_0$ color index is established using modern, high-precision angular diameters from optical interferometers. Applied to data for the galactic (cluster) Cepheid U Sgr, this method yields a distance of 0.660 $\\pm$ 0.024 kpc and a true distance modulus of 9.10 $\\pm$ 0....

  10. Causation and methods of skull trepanation in the past from the point of view of the latest findings from the Czech territory.

    Czech Academy of Sciences Publication Activity Database

    Likovský, Jakub; Malyková, Drahomíra; Brzobohatá, Hana; Stránská, Petra

    2010-01-01

    Ro?. 48, ?. 1 (2010), s. 19-32. ISSN 0323-1119 Institutional research plan: CEZ:AV0Z80020508 Keywords : paleopathology * trepanation * trepanation methods * cranial trauma * intracranial hematoma * La Tène period * Middle Ages * Central Europe Subject RIV: AC - Archeology, Anthropology, Ethnology

  11. 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 ...

  12. Assessment of prior learning in vocational education and training : findings from a study about methods for assessing prior learning in preparation for vocational Qualifications (VET)

    DEFF Research Database (Denmark)

    Wahlgren, Bjarne; Aarkrog, Vibe

    The article deals about the results of a study of the assessment of prior learning among adult workers who want to obtain formal qualifications as skilled workers. The study contributes to developing methods for assessing prior learning including both the teachers’ ways of eliciting the students’ knowledge, skills and competences during the students’ performances and the methods that the teachers apply in order to assess the students’ prior learning in relation to the regulations of the current VET-program. In particular the study focuses on how to assess not only the students’ explicated knowledge and skills but also their competences, i.e. the way the students use their skills and knowledge to perform in practice. Based on a description of the assessment procedures the article discusses central issues in relation to the assessment of prior learning. The empirical data have been obtained in the VET programs for gastronomes respectively child-care assistants.

  13. Assessment of prior learning in vocational education and training : Finding from a study about methods for assessing prior learning in preparation for vocational Qualifications (VET)

    DEFF Research Database (Denmark)

    Wahlgren, Bjarne; Aarkrog, Vibe

    The article deals about the results of a study of the assessment of prior learning among adult workers who want to obtain formal qualifications as skilled workers. The study contributes to developing methods for assessing prior learning including both the teachers’ ways of eliciting the students’ knowledge, skills and competences during the students’ performances and the methods that the teachers apply in order to assess the students’ prior learning in relation to the regulations of the current VET-program. In particular the study focuses on how to assess not only the students’ explicated knowledge and skills but also their competences, i.e. the way the students use their skills and knowledge to perform in practice. Based on a description of the assessment procedures the article discusses central issues in relation to the assessment of prior learning. The empirical data have been obtained in the VET programs for gastronomes respectively child-care assistants.

  14. Assessment of prior learning in vocational education and training : Findings from a study about methods for assessing prior learning in preparation for vocational qualifications (VET)

    DEFF Research Database (Denmark)

    Aarkrog, Vibe; Wahlgren, Bjarne

    The article deals about the results of a study of the assessment of prior learning among adult workers who want to obtain formal qualifications as skilled workers. The study contributes to developing methods for assessing prior learning including both the teachers’ ways of eliciting the students’ knowledge, skills and competences during the students’ performances and the methods that the teachers apply in order to assess the students’ prior learning in relation to the regulations of the current VET-program. In particular the study focuses on how to assess not only the students’ explicated knowledge and skills but also their competences, i.e. the way the students use their skills and knowledge to perform in practice. Based on a description of the assessment procedures the article discusses central issues in relation to the assessment of prior learning. The empirical data have been obtained in the VET programs for gastronomes respectively child-care assistants.

  15. Metáforas e Linguística de Corpus: metodologia de análise aplicada a um gênero de negócios Metaphors and Corpus Linguistics: a method for finding metaphors in a business genre

    Directory of Open Access Journals (Sweden)

    Tony Berber Sardinha

    2011-01-01

    Full Text Available O presente trabalho visa a relatar o desenvolvimento de uma metodologia de identificação de metáforas em corpora eletrônicos. Como exemplo, foi tomado o gênero teleconferências de apresentação de resultados financeiros. A metodologia é do tipo "bottom-up" / "corpus-driven" e se baseia na identificação de palavras com frequência marcante (palavras-chave e de seus padrões de co-ocorrência, seguido do cálculo de similaridade semântica entre essas palavras. Com isso, chega-se a um conjunto de palavras que são então interpretadas em seu co-texto, por meio de concordâncias.This paper aims at reporting the development of a method for metaphor identification in computer corpora. The method was tested on a particular corpus, namely of investment conference calls, and comprises procedures that work from the bottom up, and rely on marked frequency, collocation and semantic similarity as signalling devices for metaphor. As such, the method is an example of corpus-driven research into metaphor. The application of these procedures yields a number of metaphor candidates, which are then checked manually through concordances.

  16. A practical method of active case finding and epidemiological assessment: its origin and application in the leprosy control project in Indonesia.

    Science.gov (United States)

    Louhenapessy, A A; Zuiderhoek, B

    1997-12-01

    Random sample surveys in the past have revealed high estimated against low registered prevalences for leprosy in several parts of Indonesia. A pilot project showed that the problem of cases that had not yet been detected could not be solved without the active participation of the local authorities, who proved able to overcome the stigma and to convince potential patients to go for examination and treatment. The pilot project was based on the principle of what are called exploration surveys, which were introduced by Sitanala in Indonesia in 1931. The Indonesian government decided to reintroduce these surveys in 1977 under the name of chase or trace surveys. They are carried out within the framework of the leprosy workers' routine duties and no additional expenses are incurred. Since then, thousands of patients of all types and with long case histories have been detected and brought under treatment. Without this "push" it is fair to assume that many would never have sought treatment voluntarily. In view of the experience in Indonesia, one wonders whether leprosy can be eliminated without emphasizing the importance of active case finding, especially in areas in which the disease is still highly endemic. Chase surveys also provide rough information about the local leprosy situation. Although of great value, they are not, in high-endemic regions, an alternative to random sample surveys which reveal, besides a wealth of additional information, the possible unknown sources of infection. PMID:9465159

  17. Estimates of neonatal morbidities and disabilities at regional and global levels for 2010: introduction, methods overview, and relevant findings from the Global Burden of Disease study

    Science.gov (United States)

    Blencowe, Hannah; Vos, Theo; Lee, Anne CC; Philips, Rachel; Lozano, Rafael; Alvarado, Miriam R.; Cousens, Simon; Lawn, Joy E.

    2013-01-01

    Background: Neonatal mortality and morbidity are increasingly recognized as important globally, but detailed estimates of neonatal morbidity from conditions and long-term consequences are yet to be published. Methods: We describe the general methods for systematic reviews, meta-analyses, and modeling used in this supplement, highlighting differences from the Global Burden of Disease (GBD2010) inputs and methods. For five conditions (preterm birth, retinopathy of prematurity, intrapartum-related conditions, neonatal infections, and neonatal jaundice), a standard three-step compartmental model was applied to estimate—by region, for 2010—the numbers of (i) affected births by sex, (ii) postneonatal survivors, and (iii) impaired postneonatal survivors. For conditions included in GBD2010 analyses (preterm birth and intrapartum-related conditions), impairment at all ages was estimated, and disability weights were applied to estimate years lived with disability (YLD) and summed with years of life lost (YLL) to calculate disability-adjusted life years (DALYs). Results: GBD2010 estimated neonatal conditions (preterm birth, intrapartum-related, neonatal sepsis, and “other neonatal”) to be responsible for 202 million DALYs or 8.1% (7.3–9.0%) of the worldwide total. Mortality contributed 95% of the DALYs, and the estimated 26% reduction in neonatal condition DALYs since 1990 is primarily due to a 44% reduction in neonatal mortality rate due to these conditions, counterbalanced by increased numbers of babies born (17%). Impairment following neonatal conditions remained stable globally and is therefore relatively more important, especially in high- and middle-income countries. Crucial data gaps were identified. Conclusion: These results confirm neonatal conditions as a significant burden, reemphasizing the need to reduce deaths further, to count the linked 2.6 million stillbirths, and to better measure and address their long-term effects. PMID:24366460

  18. Near-infrared variant of the Barnes-Evans method for finding Cepheid distances calibrated with high-precision angular diameters

    Science.gov (United States)

    Welch, Douglas L.

    1994-10-01

    The advantages of a near-infrared variant of the Barnes-Evans method for estimating distances to Cepheid variables are described and quantified. A surface brightness-color relation for K photometry and the (V-K)0 color index is established using modern, high-precision angular diameters from optical interferometers. Applied to data for the galactic (cluster) Cepheid U Sgr, this method yields a distance of 0.660 +/- 0.024 kpc and a true distance modulus of 9.10 +/- 0.07 mag. This estimate compares with the true distance modulus of 9.37 +/- 0.22 mag estimated by Gieren et al. (1993) using the classical Barnes-Evans technique. The possibility of estimating distances of Large Magellanic Cloud (LMC) and Small Magellanic Cloud (SMC) Cepheids directly -- without intermediate steps -- is discussed. The feasibility of determining the distance of M31 or M33 using this technique is examined and is probably within the reach of 8 m class telescopes.

  19. 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.  

  20. 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.

  1. Feasibility of finding malignant diseases with the Ar + 501.7 nm laser line using a new blood-analysis method

    Science.gov (United States)

    Sato, H.; Hayashi, H.; Totsuka, T.; Sugiyama, M.; Tsuchiya, S.; Takeuchi, K.; Mochida, N.

    1983-12-01

    Utilizing a new blood-analysis method which uses the interaction between an Ar + laser beam and a blood sample, it can be shown that there is a significant difference in the reflectance variation ? R between the malignant and benign blood, at 501.7 nm of the Ar + laser, under a dc magnetic field, for both human and mouse blood. For the malignant mouse-blood with leukaemia, ? R tends to be positive with the magnetic field, while for the benign blood it is negative. This is also true for the human blood. This fact is confirmed by the inverted variation of the higher order Fourier pattern obtained by the Fourier pattern analyser from the transmitted beam through the diluted sample, for the malignant and benign mouse-blood under the magnetic field.

  2. 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.

  3. Radiological findings in angiofibroma

    International Nuclear Information System (INIS)

    Surgery after pre-operative embolization has become the main treatment modality in angiofibroma therapy. As surgical planning is based on precise pre-operative tumour evaluation, knowledge of the characteristic growth patterns is of great interest. Analysis of tumour extension and blood supply, as well as methods of controlling intra-operative bleeding, help in determining the appropriate surgical approach. Though benign, angiofibroma demonstrates a locally aggressive nature. This fibrovascular tumour is characterised by typical radiological findings and by predictable growth patterns. The tumour extension and blood supply can be accurately determined by CT, MR imaging and angiography. With classic radiological findings, no pre-operative biopsy is necessary in most angiofibromas. Advances in radiological imaging have contributed to improved surgical planning and tumour resection. The surgeon is able to select the least traumatic approach with secure haemostatic control, which is also critical for avoiding the disturbance of facial skeletal growth in this group of young patients. Embolization, pre-operative autologous donation and the cell saver system for immediate retransfusion of the collected blood after filtration, are important tools for dealing with blood loss in angiofibroma surgery as they minimize homologous blood transfusion

  4. Radiological findings in angiofibroma

    Energy Technology Data Exchange (ETDEWEB)

    Schick, B. [Univ. of Marburg (Germany). Dept. of Ear, Nose and Throat Diseases; Kahle, G. [Univ. of Marburg, (Germany). Inst.of Radiology

    2000-11-01

    Surgery after pre-operative embolization has become the main treatment modality in angiofibroma therapy. As surgical planning is based on precise pre-operative tumour evaluation, knowledge of the characteristic growth patterns is of great interest. Analysis of tumour extension and blood supply, as well as methods of controlling intra-operative bleeding, help in determining the appropriate surgical approach. Though benign, angiofibroma demonstrates a locally aggressive nature. This fibrovascular tumour is characterised by typical radiological findings and by predictable growth patterns. The tumour extension and blood supply can be accurately determined by CT, MR imaging and angiography. With classic radiological findings, no pre-operative biopsy is necessary in most angiofibromas. Advances in radiological imaging have contributed to improved surgical planning and tumour resection. The surgeon is able to select the least traumatic approach with secure haemostatic control, which is also critical for avoiding the disturbance of facial skeletal growth in this group of young patients. Embolization, pre-operative autologous donation and the cell saver system for immediate retransfusion of the collected blood after filtration, are important tools for dealing with blood loss in angiofibroma surgery as they minimize homologous blood transfusion.

  5. 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 patientachnoids 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)

  6. Aplicação do delineamento simplex-centroide no estudo da cinética da oxidação de biodiesel B100 em mistura com antioxidantes sintéticos / The simplex-centroid design applied to study of the kinetics of the oxidation of B100 biodiesel in blend with synthetic antioxidants

    Scientific Electronic Library Online (English)

    Dionísio, Borsato; Luiz Henrique, Dall' Antonia; Carmen Luísa B., Guedes; Elaine Cristina R., Maia; Heverson Renan de, Freitas; Ivanira, Moreira; Kelly Roberta, Spacino.

    1726-17-01

    Full Text Available [...] Abstract in english Antioxidants are an alternative to prevent or slow the degradation of the biofuel. In this study, it was evaluated the oxidative stability of B100 biodiesel from soybean oil in the presence of three commercial synthetic antioxidants, butylated hydroxyanisole (BHA), butylated hydroxytoluene (BHT) and [...] tert-butylhydroquinone (TBHQ), pure or blended, from the experimental design of simplex-centroid mixture. The reaction order and rate constant were also calculated for all tests. The treatment containing pure TBHQ proved to be the most effective, proven by design, the optimum mix obtained and the rate constant. Binary and ternary mixtures containing TBHQ also showed appreciable antioxidant effect.

  7. Aplicação do delineamento simplex-centroide no estudo da cinética da oxidação de biodiesel B100 em mistura com antioxidantes sintéticos The simplex-centroid design applied to study of the kinetics of the oxidation of B100 biodiesel in blend with synthetic antioxidants

    Directory of Open Access Journals (Sweden)

    Dionísio Borsato

    2010-01-01

    Full Text Available Antioxidants are an alternative to prevent or slow the degradation of the biofuel. In this study, it was evaluated the oxidative stability of B100 biodiesel from soybean oil in the presence of three commercial synthetic antioxidants, butylated hydroxyanisole (BHA, butylated hydroxytoluene (BHT and tert-butylhydroquinone (TBHQ, pure or blended, from the experimental design of simplex-centroid mixture. The reaction order and rate constant were also calculated for all tests. The treatment containing pure TBHQ proved to be the most effective, proven by design, the optimum mix obtained and the rate constant. Binary and ternary mixtures containing TBHQ also showed appreciable antioxidant effect.

  8. 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.

  9. 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

  10. Finding beam focus errors automatically

    Energy Technology Data Exchange (ETDEWEB)

    Lee, M.J.; Clearwater, S.H.; Kleban, S.D.

    1987-01-01

    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. (LEW)

  11. Exploration method for finding uranium ore bodies

    International Nuclear Information System (INIS)

    The migration of a uranium ore body through geologic time may be determined by subjecting the carbonaceous material in host rock to vitrinite reflectance analysis. A substantial variation in the reflectance is an indication of anomalous coalification induced by radiation from uranium ore

  12. Find a Surgeon

    Science.gov (United States)

    ... to find out more. Facial Cosmetic Surgery Facial Cosmetic Surgery Extensive education and training in surgical procedures involving ... to find out more. Facial Cosmetic Surgery Facial Cosmetic Surgery Extensive education and training in surgical procedures involving ...

  13. Find a Dermatologist

    Science.gov (United States)

    Find a Dermatologist A dermatologist is a doctor who specializes in treating conditions that affect the skin, hair, and ... in reliance on the information contained therein. Find a free SPOT me? skin cancer screening. State: AL ...

  14. On König's root finding algorithms

    DEFF Research Database (Denmark)

    Buff, Xavier; Henriksen, Christian

    2003-01-01

    In this paper, we first recall the definition of a family of root-finding algorithms known as König's algorithms. We establish some local and some global properties of those algorithms. We give a characterization of rational maps which arise as König's methods of polynomials with simple roots. We then estimate the number of non-repelling cycles König's methods of polynomials may have. We finally study the geometry of the Julia sets of König's methods of polynomials and produce pictures of parameter spaces for König's methods of cubic polynomials.

  15. Finding small inhomogeneities from surface scattering data

    OpenAIRE

    Ramm, A. G.

    1999-01-01

    A method is given for finding small inhomogeneities from surface scattering data. The method consists in localization of the positions and finding the intensities of these small inhomogeneities. The case of acoustic wave scattering is studied, but the method is applicable to electromagnetic waves as well.

  16. 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.

  17. Sonographic Findings of Human Fascioliasis

    OpenAIRE

    F. Mansour Ghanaei; A Alizadeh; Z. Pourrasouli; H. Vahidi; M.R. Naghipour

    2006-01-01

    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 internist...

  18. Finding solution by Tabu search

    Directory of Open Access Journals (Sweden)

    Ratanamanee, W.

    2003-11-01

    Full Text Available In this paper, the method of finding the solution by Tabu search is addressed. Tabu search is one of the local search heuristics, which has been applied extensively in operations research works. In this paper, the basic concepts of the Tabu search heuristic and some examples of applying this search technique in operations research problems are presented.

  19. Find a Plume, Find a Vent

    Science.gov (United States)

    This classroom activity gives students an appreciation for the difficulties deep sea researchers must face in order to find hydrothermal vents. Working in small groups, students can complete this Web investigation in a single class period. The printable handout includes a series of inquiry-based questions that prompt students to use what they already know about mid-ocean ridges to hypothesize about how scientists locate deep sea vents, detailed directions for a Web research project that takes them on a virtual deep sea journey investigating hydrothermal vents, and a worksheet that helps students apply their building knowledge to locate a vent in the northern Pacific Ocean.

  20. 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

  1. 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)

  2. 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)

  3. 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.

  4. Africa Region: Findings

    Science.gov (United States)

    _Findings_ reports on ongoing operational, economic, and sector work carried out by the World Bank and its member governments in the Africa Region. Currently, issues of agricultural extension in Madagascar, drought and Sub-Saharan African economies, and gender issues in Ethiopia are discussed in four Findings articles (Nos. 117-119).

  5. 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)

  6. CT findings of colonic diverticulitis

    International Nuclear Information System (INIS)

    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)

  7. Radiologic findings of anthracofibrosis

    International Nuclear Information System (INIS)

    To evaluate the CT findings of bronchial anthracofibrosis. Fourteen patients with bronchoscopically confirmed anthracofibrosis were involved in this study. CT findings (n=3D12) were retrospectively analysed; the pattern, distri-bution and extent of bronchial and parenchymal abnormalities and additional findings such as mediastinal lymphadenopathy and pleural effusion were assessed. Age, sex, and occupational and disease history were history were also reviewed. Patients were aged between 63 and 95 (mean, 71.3) years, and ten were female. Only one patient had an occupational history, but four had a history of pulmonary tuberculosis. Frequent radiologic findings were bronchial wall thickening(n=3D6), atelectasis(n=3D8), mediastinal lymphad-enopathy(n=3D7) and mass(n=3D4). Other accompanying findings were bronchial wall calcification(n=3D3), consolidation(n=3D2) and pleural effusion(n=3D2). Right upper (n=3D7) and right middle lobe(n=3D7) were the most commonly involved sites, and multifocal involvement (n=3D7) was frequent. Bronchial wall thickening, atelectasis and mediastinal lymphadenopathy were characteristic CT findings of anthracofibrosis. When such findings are noted in older or aged female patients, anthracofibrosis should be included in the differential diagnosis

  8. 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

  9. Find a Free Clinic

    Science.gov (United States)

    ... Membership Benefits Members Only Area Login Find a Free or Charitable Clinic Search for clinics near ... Within ... 7 8 9 … next › last » National Association of Free & Charitable Clinics Address 1800 Diagonal Road, Suite 600 ...

  10. Find a Dentist

    Science.gov (United States)

    ... information you need from the Academy of General Dentistry Saturday, June 06, 2015 About | Contact Find an ... more. Disclaimer of Liabilities The Academy of General Dentistry's (AGD) Web site provides a listing of members ...

  11. Finding a PTSD Therapist

    Science.gov (United States)

    ... National Center for PTSD » Public » Finding a Therapist PTSD: National Center for PTSD PTSD PTSD Home For the Public Public Section ... Health Connect with us Share this page Search PTSD Site Choose Section Enter Term and Search Advanced ...

  12. Find a Healthcare Professional

    Science.gov (United States)

    ... Bahadur.html||| 336737603|||46.7914478|||-92.0943209|||Deanna Bakken|||400 E 1st St|||Duluth|||55805|||MN|||||||||, Gastroenterology|||||||||||| ... living-with-crohns-colitis/find-a-doctor/Deanna-Bakken.html||| 599023069|||38.8691258|||-77.2346695|||Nader H. ...

  13. A novel method of spectrum stabilization

    International Nuclear Information System (INIS)

    A new type of spectrum stabilizer for a scintillation spectrometer is described. A pulse light source DM 160 is used to introduce an artificial peak in the spectrum at a convenient energy. The centroid of pulse spectrum corresponding to artificial peak is compared with that of suitable reference pulses obtained from the DM 160 driver circuit. Any drift in artificial peak produces a d.c. voltage at the output of centroid comparator and this voltage is used to control the gain of variable gain amplifier to counter the drift. With suitable adjustment the effect of any variation in pulse height of DM 160 driving pulse can be compensated so that the spectrometer gain is independent of any variation, drift etc. in the height of pulse driving DM 160 tube. This circuit is simple and gives improved performance compared to 2 channel method of obtaining the control voltage for variable gain amplifier. (author)

  14. Aortic Coarctation: Radiologic Findings

    International Nuclear Information System (INIS)

    Aortic coarctation is an infrequent vascular malformation that causes arterial hypertension. Some signs have been described in the physical examination. They strongly suggest the diagnosis, nevertheless it is not easy to identify these findings in all patients, and is in these cases where radiologic studies suggest and confirm the diagnosis. In this article we present the case of a patient with aortic coarctation and we correlate the radiographic, angiographic-spiral CT and renal Doppler findings.

  15. Sylfiden findes : en svævebog

    DEFF Research Database (Denmark)

    Christensen, Anne Middelboe

    2008-01-01

    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 balletdansere i hovedpartierne i Sylfiden fra 1836 til 2008, et sylfideleksikon og sylfideord for børn. En videnskabelig bog, formidlet for både ballethistorikeren, balletelskeren, balletbegynderen og romantikdyrkeren. Resumé på engelsk, fransk, spansk og russisk.

  16. Lasers, Let's Find 'Em!

    Science.gov (United States)

    VU Bioengineering RET Program, School of Engineering,

    Students research particular types of lasers and find examples of how they are used in technology today. Teams present their findings by means of PowerPoint presentations, videos or brochures. The class takes notes on the presentations using a provided handout. This activity prepares students for the "go public" phase of the legacy cycle in which they solve the grand challenge by designing and producing a laser-based security system.

  17. Finding gaps in a spectrum

    International Nuclear Information System (INIS)

    We propose a method for finding gaps in the spectrum of a differential operator. When applied to the one-dimensional Hamiltonian of the quartic oscillator, a simple algebraic algorithm is proposed that, step by step, separates with a remarkable precision all the energies even for a double-well configuration in a tunnelling regime. Our strategy may be refined and generalized to a large class of 1D-problems. (fast track communication)

  18. Finding gaps in a spectrum

    CERN Document Server

    Giacomini, Hector

    2007-01-01

    We propose a method for finding gaps in the spectrum of a differential operator. When applied to the one-dimensional Hamiltonian of the quartic oscillator, a simple algebraic algorithm is proposed that, step by step, separates with a remarkable precision all the energies even for a double-well configuration in a tunnelling regime. Our strategy may be refined and generalised to a large class of 1d-problems.

  19. Hematological findings in Noonan syndrome

    OpenAIRE

    Bertola Débora R.; Carneiro Jorge David A.; Amico E?lbio Anto?nio, D.; Kim Chong A.; Albano Lilian Maria José; Sugayama Sofia M. M.; Gonzalez Claudette H.

    2003-01-01

    OBJECTIVE: Noonan syndrome is a multiple congenital anomaly syndrome, and bleeding diathesis is considered part of the clinical findings. The purpose of this study was to determine the frequency of hemostatic abnormalities in a group of Noonan syndrome patients. METHOD: We studied 30 patients with clinical diagnosis of Noonan syndrome regarding their hemostatic status consisting of bleeding time, prothrombin time, activated partial thromboplastin time and thrombin time tests, a platelet count...

  20. CT findings of periappendiceal abscesses

    Energy Technology Data Exchange (ETDEWEB)

    Kang, Hyun Ill; Kang, Kyung Sook; Suh, Myung Ok; Lee, Yul; Chung, Soo Young; Bae, Sang Hoon; Yoon, Jong Sup [College of Medicine, Hallym University, Chuncheon (Korea, Republic of)

    1987-04-15

    CT has been widely used in the diagnosis of intra-abdominal abscesses, but its findings of periappendiceal abscesses are not well known. CT findings of 15 cases of periappendiceal abscesses were analyzed retrospectively. The results were as follows; 1.The most prevalent age groups were 5th. and 6th. decades and a male to female ratio was 7:8. 2.CT findings of periappendiceal abscesses were cystic low density mass in 7 cases (46.5%), solid soft tissue mass in 2 patients (13.5%) and mixed density mass in 6 cases (40%). 3.Associated CT findings were fat plane obliteration in 12 cases (80%), fascial thickening in 10 cases (66%), enhancing wall in 7 cases (46.5%), internal air density in 5 cases (33%), cecal wall thickening in 3 cases (20%) and ascites in 2 cases (13.5%). 4.Abscess was localized in RLQ medial to cecum in 10 cases (66%), extended to posterior pararenal space in 2 cases (13.5%), pelvic cavity in 2 cases (13.5%) and RUQ in 1 case (7%). We think that CT is an useful diagnostic method of periappendiceal abscesses especially when clinical findings are atypical.

  1. Study of nuclear giant resonances using a Fermi-liquid method

    CERN Document Server

    Sun, Bao-Xi

    2012-01-01

    The nuclear giant resonances are studied by using a Fermi-liquid method, and the nuclear collective excitation energies of different values of $l$ are obtained, which are fitted with the centroid energies of the giant resonances of spherical nuclei, respectively. In addition, the relation between the isovector giant resonance and the corresponding isoscalar giant resonance is discussed.

  2. A modified semi-supervised color image segmentation method

    Directory of Open Access Journals (Sweden)

    Chai Fangyong

    2012-08-01

    Full Text Available The paper proposed a modified color image segmentation method basing on semi-supervised hidden Markov random fields (HMRF with constraints. Making use of MeanShift algorithm to get supervision information and, cluster number and initial values for cluster centroids, color images can be segmented effectively with the method in this paper by K-Means algorithm. The experimental results are very encouraging.

  3. Fibrosing mediastinitis - radiological findings

    International Nuclear Information System (INIS)

    The authors report a diffuse pattern case of idiopathic fibrosing mediastinitis in a 25-year-old woman with headache, face and chest swelling, and pain in the right upper extremity. The chest radiographic finding was a mediastinal mass and a diffuse soft process in the computed tomography. The diagnosis was made after exploratory surgery. The patient has been under steroid therapy for two years without detectable changes in radiographic findings. The authors also report the differential diagnosis and the radiological imaging role in the diagnosis and follow-up of patients with fibrosing mediastinitis. (author)

  4. Intrathoracic gossypiboma: imaging findings

    International Nuclear Information System (INIS)

    The authors report three cases of intrathoracic foreign body that is defined as a cotton matrix mass, mostly retained surgical sponge, a rare complication of a thoracic surgery. The patients were evaluated by chest radiography and computed tomography with the imaging findings confirmed after thoracotomy and anatomopathological study. The mainly imaging findings consisted of intrathoracic masses in patients with previous thoracic surgery that return to hospital with lower respiratory tract symptoms in different period after surgery procedure. The three cases were related with a brief review of the literature. (author)

  5. Convergence of the synaptic weights for the elastic net method, and its application

    Science.gov (United States)

    Ghamasaee, Rahman; Goldberg, Jeffrey B.

    1997-06-01

    Solution procedures for the traveling salesman problem (TSP), i.e. the problem of finding the minimum Hamiltonian circuit in a network of cities, can be divided into two categories: exact methods and approximate (or heuristic) methods. Since TSP is an NP hard problem, good heuristic approaches are of interest. The neural networks heuristic solutions of TSP was initiated by Hopfield and Tank. One such heuristic called the elastic net method is illustrated by the following, an imaginary rubber band is placed at the centroid of the distribution of n cities. Then some finite number (m greater than n) of points (nodes) on this rubber band changes their positions according to the dynamics of the method. Eventually they describe a tour around the cities. We express the dynamics and stability of the elastic net algorithm. We show that if a unique node is converging to a city, then the synaptic strength between them approaches one. Then we generalize to the case where more than one node converges to a city. Furthermore, a typical application that could make use of the elastic net method (e.g. multi-target tracking) will be pointed out for later studies. In order to verify the proof of the concept and the associated theorems, computer simulations were conducted for a reasonable number of cities.

  6. [Utterly unanticipated findings].

    Science.gov (United States)

    Jordan, Bertrand

    2015-05-01

    There are now a number of cases in which non-invasive prenatal testing (NIPT) has detected signs of cancer in pregnant women. These unexpected findings raise a number of difficult questions regarding their communication to the patient as well as the wording of informed consent forms. PMID:26059309

  7. 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)

  8. Neuroradiological findings in Behcet's disease

    International Nuclear Information System (INIS)

    Purpose: We present the typical neuroradiological findings in three patients with neuro-Behcet in comparison with a review of neuroradiological and histopathological findings described in the literature. Material and Methods: In three male patients aged 32-57 years with Behcet's disease and neurological symptoms cranial CT and MRI studies were carried out. Findings were monitored over a period of 6-18 months. Additionally, cerebral and renal DSA were performed in two patients. Results: In two patients we found acute inflammatory lesions located in the brainstem and the periventricular white matter, some of which were associated with an acute inflammatory disruption of the blood-brain barrier. Lesions decreased in size under treatment, but complete resolution was not consistently noted. In the third patient we found a thrombosis of the superior sagittal sinus but no other intracranial abnormalities. Conclusions: Our findings agree with those described in the literature as being typical of Behcet's disease. Inflammatory lesions most commonly occur in the brain stem, followed by the basal ganglia and the cortex and white matter of both the cerebrum and cerebellum. In contrast to venous sinus thrombosis, brainstem atrophy and cortical or cerebellar lesions, white matter lesions have little diagnostic value, irrespective of their location. The definitive diagnosis of Behcet's disease is made on the basis of clinical criteria. (orig.).)

  9. 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

  10. Finding Out What Works

    Science.gov (United States)

    Broady, Elspeth

    2004-01-01

    As teachers, people often dream of research results which will tell them, with scientific accuracy, what is going to work in their classroom. However, as researchers, people know how elusive such "recipes" or "best methods" are. Conventional quantitative research methods have been designed to identify the effect of "factor X" in a given context,…

  11. Implementing findings of research.

    OpenAIRE

    Haines, A.; Jones, R.

    1994-01-01

    There are unacceptable delays in the implementation of many findings of research. This results in suboptimal care for patients. A number of approaches may be effective in speeding up implementation, including evidence based guidelines, the influence of opinion leaders, and computer based decision support systems. An integrated approach to speeding up this process by means of a number of mechanisms is likely to be most effective. The results of systematic reviews of the research literature sho...

  12. 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 findcm 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.

  13. 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.

  14. The Great Fossil Find

    Science.gov (United States)

    Steve Rendak

    1999-01-01

    On an imaginary fossil hunt, learners "find" (remove from envelope) paper "fossils" of some unknown creature, only a few at a time. Each time, they attempt to reconstruct the creature, and each time their interpretation tends to change as new pieces are "found." Use this as an introduction to the nature of science inquiry -- scientists don't always have all the information, scientists must form interpretations of the information, scientists must work together to come to consensus about interpretations.

  15. CT findings in leukemia

    International Nuclear Information System (INIS)

    Review of 84 computed tomographic (CT) scans in leukemic patients demonstrate a wide spectrum of abnormalities. Findings caused by leukemia were lymphadenopathy, visceral enlargement, focal defects, and tissue infiltration. Hemorrhage was by far the most common complication and could usually be characterized on the noncontrast CT scan. The distinction between old hematomas, foci of infection, and leukemia infiltration could not be made with certainty without CT-guided aspiration. Unusual instances of sepsis, such as microabscesses of the liver and typhlitis, were seen

  16. 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.

  17. MELAS syndrome: neuroradiological findings

    International Nuclear Information System (INIS)

    To assess the computed tomography (CT) and magnetic resonance (MR) findings in MELAS syndrome (mitochondrial encephalomyopathy, lactic acidosis and stroke-like episodes) and their contribution to the diagnosis of this entity. We present three patients in which a diagnosis of MELAS syndrome was confirmed by muscle biopsy. CT revealed pathological findings in two patients: bilateral calcifications in the basal nuclei in one and low-attenuation lesions in occipital lobes in the other. Initial or follow-up MR demonstrated pathological findings highly suggestive of MELAS syndrome in all the patients. They consisted of hyperintense lesions in T2-weighted images, located predominantly in the cortex of occipital and parietal lobes. Cerebellar atrophy was also observed in two patients. The clinical signs varied, but epileptic seizures, headache, vomiting, ataxia, muscle weakness and pyramidal involvement were among the major ones. Only one patient presented high lactic acid levels, and in two, the initial muscle biopsy was not conclusive enough to provide the definitive diagnosis. CT and, especially, MR are useful tools in the diagnosis of MELAS syndrome, particularly in those cases in which initial negative laboratory and histological results make diagnosis difficult. (Author) 21 refs

  18. ASGE: Find a Doctor

    Science.gov (United States)

    ... the only medical society that requires documentation of specific training in GI endoscopic procedures. To locate an ASGE member in your area, you can search by any of the following methods: Name, City/State, Zip Code, or Country. Last ...

  19. 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 ?9-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. ?9-tetrahydrocannabinolic acid A (THCA-A), the non-psychoactive biogenetic precursor of ?9-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. Copyright © 2014 John Wiley & Sons, Ltd. PMID:25069954

  20. 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)

  1. Find-It! Consumer

    Science.gov (United States)

    From the Washington State Library, Find-It! Consumer provides links to and information about over 100 consumer safety and protection Websites. Annotated Websites concerning Washington State or the entire United States may be searched by keyword or browsed by topic. The librarians have included a wonderful section on Top Searches, which gives guides to information and resources on a broad range of subjects, from insecticide in food to choosing an Internet service provider. Up-to-date recalls and new consumer information are also highlighted.

  2. Finding the 0-- Glueball

    Science.gov (United States)

    Qiao, Cong-Feng; Tang, Liang

    2014-11-01

    With appropriate interpolating currents the mass spectrum of the 0-- oddball is obtained in the framework of QCD sum rules. We find there are two stable oddballs with masses of 3.81 ±0.12 and 4.33 ±0.13 GeV , and analyze their possible production and decay modes in experiments. Noticing that these 0-- oddballs with an unconventional quantum number are attainable in BESIII, BELLEII, PANDA, Super-B, and LHCb experiments, we believe the long searched for elusive glueball could be measured shortly.

  3. 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.)

  4. CT findings of invasive pulmonary aspergillosis

    International Nuclear Information System (INIS)

    Objective: To study the CT findings of IPA. Methods: CT scans were performed in eight cases aged 25-76 years with pathologically proved IPA, two cases underwent second CT after 4 weeks. Results: CT findings includes mass-like infiltrate (n = 3), consolidation (n = 3); multi-nodules (n = 2). Conclusions: Early CT findings of IPA consist of mass-like, consolidation or multi-nodules, the CT halo sign: strongly suggests early diagnosis of IPA

  5. 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

  6. Improved primary vertex finding for collider detectors

    OpenAIRE

    Sikler, Ferenc

    2009-01-01

    Primary vertex finding for collider experiments is studied. The efficiency and precision of finding interaction vertices can be improved by advanced clustering and classification methods, such as agglomerative clustering with fast pairwise nearest neighbor search, followed by Gaussian mixture model or k-means clustering.

  7. 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)

  8. 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...

  9. 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.

  10. Aortographic findings of Takayasu's arteritis

    International Nuclear Information System (INIS)

    Takayasu's arteritis is a stenosing inflammatory process of unknown etiology affecting not only the aortic arch and its branches, but also the abdominal aorta, its branches and the pulmonary arteries. During the period from August 1971 to August 1973, 9 cases with Takayasu's arteries have been observed in the Seoul National University Hospital. The diagnosis was mainly based upon the aortography, which is the only practical method of delineating the extent and nature of the vascular involvement. The purpose of this paper is describe and analyze the radiographic findings, especially aortographic aspect. The results obtained are as follows: 1. The 9 cases are all female and two thirds are under 30 years of age. Headache, dizziness, absent or weak radial pulse and hypertension are the most common symptoms and signs. The laboratory data are generally unremarkable, except elevation of E.S.R. and gamma globulin fraction on electrophoresis. 2. Conventional roentgenography of the chest may be helpful but not specific in diagnosis of Takayasu's arteritis. 3. The aortographic findings are characteristic and pathognomonic in diagnosis of Takayasu's arteritis. In our cases, the most common findings are stenosis or occlusion of subclavian artery, diffuse narrowing with irregular contour of descending aorta, renal artery involvement, narrowing and aneurysmal dilatation of abdominal aorta, and multiple sites involvement. 4. Therefore, value of total aortography was stressedof total aortography was stressed

  11. CT findings in mucopolysaccharidoses

    International Nuclear Information System (INIS)

    The CT findings for four patients with mucopolysaccharidosis were analyzed using a Delta scan-25 (Ohio Nuclear). In three cases of Hunter's syndrome (MPS IIA 13-year-old male, MPS IIB 12-year-old male, and 25-year-old male), a dilatation of the cortical sulci was observed. Moderate dilatations were also seen in the basal cistern, the quadrigeminal cistern, and the ambient cistern. In one case of Hunter's syndrome, a low-density area was observed in the bilateral tharamic regions. An irregular low-density area was also seen in the white matter in some cases. PVL was not apparent in any case. Marked ventricular dilations were observed in cases with mental retardation, for example, in one case of Hurler's syndrome (8-year-old male) and one case of MPS IIA. The circulation and absorbtion of CSF in cortical snbarachnoid spaces were supposed to be moderately retarded by metrizamide CT cisternography. (author)

  12. 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.)

  13. 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 pneumonied 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

  14. 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 particiogical technologists more actively participate in Ai. (K.T.)

  15. 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

  16. 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

  17. 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 ?m. 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.

  18. Pulmonary talcosis: imaging findings.

    Science.gov (United States)

    Marchiori, Edson; Lourenço, Sílvia; Gasparetto, Taisa Davaus; Zanetti, Gláucia; Mano, Cláudia Mauro; Nobre, Luiz Felipe

    2010-04-01

    Talc is a mineral widely used in the ceramic, paper, plastics, rubber, paint, and cosmetic industries. Four distinct forms of pulmonary disease caused by talc have been defined. Three of them (talcosilicosis, talcoasbestosis, and pure talcosis) are associated with aspiration and differ in the composition of the inhaled substance. The fourth form, a result of intravenous administration of talc, is seen in drug users who inject medications intended for oral use. The disease most commonly affects men, with a mean age in the fourth decade of life. Presentation of patients with talc granulomatosis can range from asymptomatic to fulminant disease. Symptomatic patients typically present with nonspecific complaints, including progressive exertional dyspnea, and cough. Late complications include chronic respiratory failure, emphysema, pulmonary arterial hypertension, and cor pulmonale. History of occupational exposure or of drug addiction is the major clue to the diagnosis. The high-resolution computed tomography (HRCT) finding of small centrilobular nodules associated with heterogeneous conglomerate masses containing high-density amorphous areas, with or without panlobular emphysema in the lower lobes, is highly suggestive of pulmonary talcosis. The characteristic histopathologic feature in talc pneumoconiosis is the striking appearance of birefringent, needle-shaped particles of talc seen within the giant cells and in the areas of pulmonary fibrosis with the use of polarized light. In conclusion, computed tomography can play an important role in the diagnosis of pulmonary talcosis, since suggestive patterns may be observed. The presence of these patterns in drug abusers or in patients with an occupational history of exposure to talc is highly suggestive of pulmonary talcosis. PMID:20155272

  19. 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.

  20. Radiography can find corrosion

    International Nuclear Information System (INIS)

    Some of the advantages and limitations of using X-ray techniques to assess the severity of pitting corrosion in copper plumbing services were encountered recently. In an isolated maximum security area the services were run in basement walkways, the copper pipes being laid on brackets which held them clear of the concrete base. The location was ideal for use of X-ray techniques, which offered a means of checking short sections (18'') of the pipework without interrupting the supply. The radiographs indicated that pitting corrosion was widespread and shows the great value of X-ray examination as an aid to corrosion technology in the field, but also highlights the need for a rational interpretation of results in conjunction with other methods of visual and destructive assessment. (author)

  1. Primary thyroid lymphoma: CT findings

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Hyo-Cheol; Han, Moon Hee E-mail: hanmh@radcom.snu.ac.kr; Kim, Keon Ha; Jae, Hwan Jun; Lee, Sang Hyun; Kim, Sam Soo; Kim, Kwang Hyun; Chang, Kee-Hyun

    2003-06-01

    Introduction: To evaluate the computed tomographic (CT) findings of primary thyroid lymphoma. Methods and material: The clinicopathological data and CT images of nine patients with primary thyroid lymphoma were retrospectively reviewed. The CT appearances were classified into three types: type 1, a solitary nodule surrounded by normal thyroid tissue; type 2, multiple nodules in the thyroid, and type 3, a homogeneously enlarged both thyroid glands with a reduced attenuation with or without peripheral thin hyperattenuating thyroid tissue. Results: All patients had a rapidly enlarging thyroid mass and coexistent Hashimoto's thyroiditis. One patient showed type 1 pattern, three type 2, and five type 3. Six patients had homogeneous tumor isoattenuating to surrounding muscles. The tumors had a strong tendency to compress normal remnant thyroid and the surrounding structure without invasion. Conclusion: Primary thyroid lymphoma should be included in the differential diagnosis when old female had a homogeneous thyroidal mass isoattenuating to muscles, which does not invade surrounding structures.

  2. Primary thyroid lymphoma: CT findings

    International Nuclear Information System (INIS)

    Introduction: To evaluate the computed tomographic (CT) findings of primary thyroid lymphoma. Methods and material: The clinicopathological data and CT images of nine patients with primary thyroid lymphoma were retrospectively reviewed. The CT appearances were classified into three types: type 1, a solitary nodule surrounded by normal thyroid tissue; type 2, multiple nodules in the thyroid, and type 3, a homogeneously enlarged both thyroid glands with a reduced attenuation with or without peripheral thin hyperattenuating thyroid tissue. Results: All patients had a rapidly enlarging thyroid mass and coexistent Hashimoto's thyroiditis. One patient showed type 1 pattern, three type 2, and five type 3. Six patients had homogeneous tumor isoattenuating to surrounding muscles. The tumors had a strong tendency to compress normal remnant thyroid and the surrounding structure without invasion. Conclusion: Primary thyroid lymphoma should be included in the differential diagnosis when old female had a homogeneous thyroidal mass isoattenuating to muscles, which does not invade surrounding structures

  3. 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.

  4. 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 emergedssions 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 marke

  5. 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.

  6. Subungual glomus tumors: imaging findings

    International Nuclear Information System (INIS)

    Objective: to evaluate main imaging findings of subungual glomus tumors. Materials and methods: retrospective study of eight cases of subungual glomus tumors from the archives of two private clinics in Goiania, GO, Brazil. Plain radiographs were obtained in five cases, Doppler ultrasonography in five, and magnetic resonance imaging in five cases. Results: mean age of the patients included in the present study was 39 years, with female predominance (7:1). Tumors didn't present prevalence in any specific finger and in most of cases the tumor was located in the medial subungual region. Plain radiography was positive in five cases, demonstrating pressure erosion. Doppler ultrasonography was positive in five cases, demonstrating a hypoechoic and hyper vascularized solid nodule. Magnetic resonance imaging was positive in all of the cases, showing a solid nodule, hypointense on T1-, hyperintense on T2-weighted image, with homogeneous contrast uptake. All the patients underwent surgical excision of the lesion with histopathological confirmation. Conclusion: in most of cases, glomus tumors are subungual. The diagnosis is clinical and generally is lately achieved. Imaging methods are useful tools for the early diagnosis besides aiding in the surgical planning, considering that the treatment of choice is surgical excision (author)

  7. 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. Concluution 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)

  8. MRI findings of uveal metastases

    International Nuclear Information System (INIS)

    Objective: To evaluate MR imaging findings of uveal metastases. Methods: MR imaging findings of 20 cases with uveal metastases comfirmed by pathology or follow-up were retrospectively analyzed. MR imaging was performed in 20 patients, of which postcontrast T1-weighted imaging was performed in 19 patients including dynamic contrast enhancement scanning in four cases. Results: Metastatic tumor was found in the iris and ciliary body in two cases, and in choroid in 18 cases. The tumor demonstrated slightly hypointense signal on T1-weighted imaging and isointense signal on T2-weighted imaging in two cases, isointense signal on T1-weighted imaging and isointense signal on T2-weighted imaging in nine cases, isointense signal on T1-weighted imaging and slightly hyperintense signal on T2-weighted imaging in three cases, isointense signal on T1-weighted imaging and slightly hypointense signal on T2- weighted imaging in three cases, slightly hyperintense signal on T1-weighted imaging and slightly hypointense signal on T2-weighted imaging in two cases, and slightly hyperintense signal on T1-weighted imaging and slightly hyperintense signal on T2-weighted imaging in one case. The tumor appeared as mild thickness of the wall of the globe in eight cases, a crescent mass in three cases, a fusiform mass in seven cases, and a nodule in two cases in seven cases, and a nodule in two cases. Nineteen patients showed moderate or marked enhancement on postcontrast T1-weighted imaging. The time-intensity curve of dynamic contrast enhancement in four patients suggested a rapid enhancement and slow washout pattern. Retinal detachment was observed in 11 patients and abnormal signal intensity within the vitreous body was seen in two cases. Conclusion: MRI can display the location, shape, signal characteristics, and enhancement pattern of uveal metastases, contributing to diagnosis and differential diagnosis. (authors)

  9. 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 of the CNS lesions of Wilson's disease by using CT repeatedly. (author)

  10. Find an Endocrinology - Thyroid Specialist

    Science.gov (United States)

    ... an Endocrinology – Thyroid Specialist Find an Endocrinology – Thyroid Specialist Please tell your thyroidologist that the ATA referred ... services of physicians listed in this “Find a Specialist” resource. The physicians and surgeons listed have indicated ...

  11. AMTA's Find a Massage Therapist

    Science.gov (United States)

    ... Student Experience School Advantage AMTA News Find a Massage Therapist » Browse by location » Browse by technique » Find ... massage therapy school Proprietary Information and Legal Notice Massage is Good Medicine Read the full list >> Exercise ...

  12. 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

  13. Findings

    Science.gov (United States)

    ... Functions, Processes, Imaging, Stress Response Chemistry and Biochemistry Enzymes, Molecular Probes, Metabolic Engineering, Glycobiology, Synthesis, Natural Products, Chemical Reactions Computers in ...

  14. Finite Model Finding for Parameterized Verification

    CERN Document Server

    Lisitsa, Alexei

    2010-01-01

    In this paper we investigate to which extent a very simple and natural "reachability as deducibility" approach, originated in the research in formal methods in security, is applicable to the automated verification of large classes of infinite state and parameterized systems. The approach is based on modeling the reachability between (parameterized) states as deducibility between suitable encodings of states by formulas of first-order predicate logic. The verification of a safety property is reduced to a pure logical problem of finding a countermodel for a first-order formula. The later task is delegated then to the generic automated finite model building procedures. In this paper we first establish the relative completeness of the finite countermodel finding method (FCM) for a class of parameterized linear arrays of finite automata. The method is shown to be at least as powerful as known methods based on monotonic abstraction and symbolic backward reachability. Further, we extend the relative completeness of ...

  15. Tuberculous spondylodiscitis: MR imaging findings

    Directory of Open Access Journals (Sweden)

    Y?k?lmaz, A.

    2004-01-01

    Full Text Available Purpose: To evaluate the MR imaging findings of tuberculous spondylodiscitis. Materials and Methods: We retrospectively evaluated the MR images of 15 patients who were diagnosed as tuberculous spondylodiscitis with percutaneous or intraoperative biopsy. Tl and T2-weighted axial and sagittal and post-contrast axial and sagittal Tl-weighted spin-echo sequences were reviewed. Results: Involvement of the vertebrae and discs were seen in all patients. The most common involvement site was thoracolumbar region. Typically, affected vertebrae and discs were hyperintense on T2-weighted images, hypointense on Tl-weighted images and showed contrast enhancement. There were paravertebral soft tissue masses in 14, vertebral body compression in 12, epidural extension in ten, kyphosis in seven, involvement of the posterior vertebral elements in two and skip lesions in three patients. Conclusion: The characteristic MR imaging features of tuberculous spondylodiscitis include Tl and T2 prolongation of the affected vertebrae and discs with contrast enhancement, vertebral bony destruction with associated paravertebral soft tissue mass, often abscess formation, epidural extension, and kyphosis. MR imaging is a reliable modality in demonstrating and characterizing the spinal tuberculosis.

  16. 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)

  17. 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)

  18. Thoracic Computed Tomography Findings in Malignant Mesothelioma

    Directory of Open Access Journals (Sweden)

    Omer Tamer Dogan

    2012-01-01

    Full Text Available Background: Malignant pleural mesothelioma (MPM is an uncommon neoplasm. MPM occurs more frequently in patients born or living in certain villages of Turkey.Objectives: We aimed to review radiological findings of MPM.Patients and Methods: We reviewed the CT findings in 219 biopsy-proven MPM patients admitted to our clinic between 1993 and 2008.Results: The most common CT findings included pleural thickening (n=197, 90% classified as diffuse (n=138, 63%, nodular (n=49, 22% and mass-type (n=16, 7%. Pleural effusion was found in 173 patients (79%, involvement of the interlobar fissures in 159 (73%, mediastinal pleural involvement in 170 (78%, volume contraction in 142 (65%, mediastinal shift in102 (47% and mediastinal lymphadenopathy in 54 (25%.Conclusion: MPM may present with diverse radiological features. Pleural thickening and pleural effusion were the most frequent radiological findings. Thoracic CT scans might be assessed more cautiously in patients with environmental exposure to asbestos.

  19. 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…

  20. Computer tomographic findings of pigmented villonodular synovitis

    International Nuclear Information System (INIS)

    The CT findings in two patients with synovitis of the knee joint were analysed. Angiography is a non-specific method for the differential diagnosis of synovitis; CT, however, can be pathognomonic by showing a strikingly thick and hyperdense synovial membrane because of the iron content of the hyperplastic synovia. This is not found in non-specific synovitis. (orig.)

  1. MRI findings of congenita dysosmia

    International Nuclear Information System (INIS)

    Objective: To study the MRI findings of congenital dysosmia. Methods: Forty-seven patients with congenital dysosmia (39 with Kallmann syndrome and 8 with isolated dysosmia) and 21 normal volunteers underwent MRI examination. The features of congenital malformation were recorded. The volume of olfactory bulbs, depth of olfactory sulci as well as diameters of pituitary glands and stalks were measured. The rate of dysplasia of olfactory bulbs and tracts in the two patients groups was compared with X2 test. The difference of volume of olfactory bulbs between the two groups was evaluated with nonparametric test. And the difference of diameters of pituitary glands and stalks was analyzed with analysis of variance. Results: All the patients had abnormal findings in olfactory bulbs, tracts and/or olfactory sulci on MR images. The patterns of congenital malformation may be dysplastic of hypoplastic, symmetric or asymmetric. The proportion of patients with dysplasia of olfactory bulbs and tracts in Kallmann syndrome patients (31/39) was higher than that in isolated dysosmia ones (2/8) (X2 = 6.998, P =0.008), and the olfactory bulbs'volume of patients with Kallmann syndrome (median 8 mm3) was smaller than that of patients with isolated dysosmia (median 22 mm3) (Z = -2.902, P =0.004). The pituitary glands were smaller and the stalks were thinner in patients with Kallmann syndrome than those in volunteers [ the anteroposterior diameter oolunteers [ the anteroposterior diameter of pituitary glands in Kallmann syndrome (7.22 ± 1.93) mm, that in normal volunteers (9.94 ± 1.59) mm, F= 16.835, P =0.000; height of pituitary glands in Kallmann syndrome (3.71 ± 1.74) mm, that in normal volunteers (6.00 ± 1.24) mm, F =16.092, P =0.000; the anteroposterior diameter of pituitary stalks in Kallmann syndrome (1.19 ± 0.55) mm, that in normal volunteers (1.88 ± 0.49) mm, F =13.060, P =0.000]. Conclusions: In congenital dysosmic patients, dysplasia or hypoplasia of olfactory bulbs, tracts and sulci can be clearly depicted on MR images. MR imaging is valuable for clinical diagnosis and treatment. (authors)

  2. 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

  3. An immunological method to combine the measurement of active and total myeloperoxidase on the same biological fluid, and its application in finding inhibitors which interact directly with the enzyme.

    Science.gov (United States)

    Franck, T; Minguet, G; Delporte, C; Derochette, S; Zouaoui Boudjeltia, K; Van Antwerpen, P; Gach, O; Deby-Dupont, G; Mouithys-Mickalad, A; Serteyn, D

    2015-06-01

    Myeloperoxidase (MPO) is a pro-oxidant enzyme involved in inflammation, and the measurement of its activity in biological samples has emerged essential for laboratory and clinical investigations. We will describe a new method which combines the SIEFED (specific immunological extraction followed by enzymatic detection) and ELISA (ELISAcb) techniques to measure the active and total amounts of MPO on the same human sample and with the same calibration curve, as well as to define an accurate ratio between both the active and total forms of the enzyme. The SIEFED/ELISAcb method consists of the MPO extraction from aqueous or biological samples by immobilized anti-MPO antibodies coated onto microplate wells. After a washing step to eliminate unbound material, the activity of MPO is measured in situ by adding a reaction solution (SIEFED). Following aspiration of the reaction solution, a secondary anti-MPO antibody is added into the wells and the ELISAcb test is carried out in order to measure the total MPO content. To validate the combined method, a comparison was made with SIEFED and ELISA experiments performed separately on plasma samples isolated from human whole blood, after a neutrophil stimulation. The SIEFED/ELISAcb provides a suitable tool for the measurement of specific MPO activity in biological fluids and for the estimation of the inhibitory potential of a fluid. The method can also be used as a pharmacological tool to make the distinction between a catalytic inhibitor, which binds to MPO and inhibits its activity, and a steric inhibitor, which hinders the enzyme and prevents its immunodetection. PMID:25968947

  4. 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

  5. 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) 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

  6. Determination Method of Nonlinear Membership Function Based on the Density Function of the Square Error

    OpenAIRE

    Liu Qi; Liu Kuili; Liu Xuelin; Wang Jie; Chen Zhanwei; Huang Zhenzhen

    2013-01-01

    In this study, membership function is used to express the uncertainty in the petroleum drilling, then the fuzzy density clustering method based on density function of square error is put forward, which has avoided the defect of artificial clustering parameter and initial centroid, by using this fast algorithm, the clustering center, the number of clustering center and the parameters used for describing the nonlinear membership function can be obtained. In the simulation, the nonlinear members...

  7. CT findings of adrenal gland trauma

    International Nuclear Information System (INIS)

    Objective: To study CT findings of adrenal gland trauma(AGT). Methods: The CT images of adrenal gland trauma which were found in 1712 patients who had emergency abdominal CT examinations for assessment of blunt force trauma were analyzed restrospectively. Results: Among 1712 cases, we identified 29 patients (1.7%) with adrenal gland traumatic lesions. A total of 32 lesions were found. Twenty-six lesions were unilateral(23 right- sided, 3 left-sided), and 3 cases were bilateral (6 lesions). Main CT findings were as followed: (1) Adrenal hematomas appeared as discrete round or oval masses expanding the adrenal gland in 22 patients with 25 lesions. The lesions were hyperdense or of homogeneous density in plain scan and did not enhance in three-phase contrast-enhanced dynamic scan. The splayed adrenal limbs around hematoma were enhanced significantly as curvilinear structures. (2) Mild to moderate uniform swelling of gland was shown in 4 cases. (3) Diffuse irregular hemorrhage obliterating the gland was shown in 3 cases. Contrast extravasation was shown in 1 case, which was active bleeding from the broken adrenal gland proven by operation. Associated CT findings included strand-like hemorrhage of the periadrenal fat and posterior pararenal hemorrhage mimicking thickened diaphragmatic crus. The concurrent injuries of ipsilateral thorax or/and abdomen were found in 25 patients. Conclusion: The AGT has typical CT findings. Familiarity with characteristic CT findings of adreny with characteristic CT findings of adrenal trauma is essential for the radiologist to avoid misdiagnosis. (authors)

  8. 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.

  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

    Directory of Open Access Journals (Sweden)

    Giovanni Abrahão Salum

    2011-06-01

    Full Text Available 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 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.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 unidade 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.

  10. MR findings of chondromalacia Patella : correlation of the grade and associated lesions with arthroscopic findings

    International Nuclear Information System (INIS)

    To assess the MR findings of chondromalacia patella and correlate the grade and associated lesions with the arthroscopic findings. Twenty-five patients with pain in the anterior part of the knee underwent fat-suppressed axial and coronal T2-weighted and T2-weighted imaging, using a 10-cm field of view, and a 5-inch general purpose coil. We retrospectively assessed these findings, and the locations, grades and associated lesions, and correlated these with arthroscopic findings. We evaluated the exact location and grade of chondromalacia patella and associated lesions, as seen on MR images. These and the arthroscopic findings showed close correlation, and in cases involving this condition, MRI is thus a useful indicator of an appropriate surgical method and plan. (author). 18 refs., 5 figs

  11. Vehicle Tracking and Speed Estimation using Optical Flow Method

    Directory of Open Access Journals (Sweden)

    S.Indu,

    2011-01-01

    Full Text Available This paper presents a novel velocity estimation method for ground vehicles. The task here is to automatically estimate vehicle speed from video sequences acquired with a fixed mounted camera. The vehicle motion is detected and tracked along the frames using optical flow algorithm. The distance traveled by the vehicle is calculated using the movement of the centroid over the frames and the speed of the vehicle is estimated. The accuracy of our method was calculated by measuring the velocity manually and comparing with calculated values. The application is developed using MATLAB and SIMULINK.

  12. Finding Repeats With Fixed Gap

    OpenAIRE

    Kolpakov, Roman; Kucherov, Gregory

    2000-01-01

    We propose an algorithm for finding in a word all pairs of occurrences of the same subword with a given distance r between them. The obtained complexity is O(n\\log r +S), where S is the size of the output. We also show how the algorithm can be modified in order to find all such pairs of occurrences separated by a given word. The solution uses an algorithm for finding all quasi-squares in two strings, a problem that generalizes the known problem of searching for squares.

  13. CT findings of pulmonary aspergillosis

    Energy Technology Data Exchange (ETDEWEB)

    Cheon, Jung Eun; Im, Jung Gi; Goo, Jin Mo; Kim, Hong Dae; Han, Man Chung [Seoul National University College of Medicine, Seoul (Korea, Republic of)

    1995-10-15

    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.

  14. 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

  15. CT findings of necrotizing pneumonia

    International Nuclear Information System (INIS)

    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

  16. 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.

  17. 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.

  18. 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.

  19. HEMATOLOGIC FINDINGS IN OPERATING ROOM STAFFS

    Directory of Open Access Journals (Sweden)

    H SOLTANI

    2000-03-01

    Full Text Available Introduction. Long term exposure to trace amounts of anesthetic vapors and gases may produce hematologic and hepatic disorders in human. Since operating room (OR staffs are exposed to these agents, we decided to study their hematopoietic and hepatic systems in comparison with ordinary ward staffs. Methods. Seventy staffs from OR were compared with a matched similar number of ward staffs about their hematologic and hepatic laboratory findings in a historical cohort study. Findings. Mean of leukocyte and platelet counts were significantly lower in OR staffs, but in normal range. Mean of monocyte count was significantly higher in OR staffs. No significant differences were found between two groups for other hepatic and hematologic tests. Fatigue and headache were reported in OR staffs more than others. Conclusion. These findings may warn a risk to OR staffs but, it is not clear and requires further controlled studies.

  20. Disclosing finding and development costs

    International Nuclear Information System (INIS)

    The importance of finding and development costs in the petroleum industry and the issue of how they can be either manipulated or misunderstood was discussed. Finding and development costs are usually expressed in terms of $/BOE (barrel of oil equivalents) and reflect the total capital expenditures divided by the total reserves replaced and added. Various examples of the importance of finding and development costs in making investment decisions were used to illustrate the effects of potential bias by the resource company, and the need for care and understanding of what the numbers issued by the company actually mean. In general, low and consistent finding and development costs, combined with good netbacks, are the key to value added for shareholders. tabs

  1. A Family Finds Its Way

    Science.gov (United States)

    ... Past Issues Cover Story: Traumatic Brain Injury A Family Finds Its Way Past Issues / Fall 2008 Table ... are living with serious health conditions as a family. Photo courtesy of Stefan Radtke, www.stefanradtke.com ...

  2. 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…

  3. MRI findings in Kallmann syndrome

    OpenAIRE

    Madan R; Sawlani Vijay; Gupta Sushil; Phadke R

    2004-01-01

    Kallmann syndrome (KS) is a neuronal migration disorder characterised by hypogonadotrophic hypogonadism and anosmia or hyposmia. Five patients with clinical findings suggestive of KS were evaluated with MRI. All patients had abnormalities of olfactory system. Olfactory bulbs were absent in all patients. Olfactory sulci were absent in 3 patients and hypoplastic in 2 patients. Anterior pituitary was hypoplastic in two patients. The MRI findings in KS are characteristic and MRI is a useful adjun...

  4. MRI findings in Kallmann syndrome

    Directory of Open Access Journals (Sweden)

    Madan R

    2004-10-01

    Full Text Available Kallmann syndrome (KS is a neuronal migration disorder characterised by hypogonadotrophic hypogonadism and anosmia or hyposmia. Five patients with clinical findings suggestive of KS were evaluated with MRI. All patients had abnormalities of olfactory system. Olfactory bulbs were absent in all patients. Olfactory sulci were absent in 3 patients and hypoplastic in 2 patients. Anterior pituitary was hypoplastic in two patients. The MRI findings in KS are characteristic and MRI is a useful adjunct to the diagnosis of KS.

  5. Incidental findings of pericardial calcification

    OpenAIRE

    Nguyen, Tin; Phillips, Charles; Movahed, Assad

    2014-01-01

    Calcification of the pericardium is a relatively rare finding and often has an uncertain etiology. Incidental findings of pericardial calcification may increase due to widespread application of cardiac computed tomography for the assessment of coronary atherosclerosis in the appropriate clinical setting using coronary artery calcium scoring and/or coronary angiography. Pericardial calcification alone is asymptomatic and is neither necessary nor sufficient for the diagnosis of pericardial cons...

  6. 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.

  7. Finding curvilinear features in speckled images

    Science.gov (United States)

    Samadani, Ramin; Vesecky, John F.

    1990-01-01

    A method for finding curves in digital images with speckle noise is described. The solution method differs from standard linear convolutions followed by thresholds in that it explicitly allows curvature in the features. Maximum a posteriori (MAP) estimation is used, together with statistical models for the speckle noise and for the curve-generation process, to find the most probable estimate of the feature, given the image data. The estimation process is first described in general terms. Then, incorporation of the specific neighborhood system and a multiplicative noise model for speckle allows derivation of the solution, using dynamic programming, of the estimation problem. The detection of curvilinear features is considered separately. The detection results allow the determination of the minimal size of detectable feature. Finally, the estimation of linear features, followed by a detection step, is shown for computer-simulated images and for a SAR image of sea ice.

  8. 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

  9. Carcinoma of the urachus: findings in CT

    International Nuclear Information System (INIS)

    Carcinoma of the urachus is an uncommon neoplasm of poor prognosis, party due to the anatomic location of the tumor which permits it a silent and prolonged course prior to diagnosis. CT, which discloses characteristic findings, is the most useful method for diagnoses carcinoma of the urachus and assessing its extension. Three cases of urachal carcinoma are presented (a transitional cell carcinoma and two mucinous adenocarcinomas), one of which was associated with pseudomyxoma peritonea. (Author)

  10. Optimal Occulter Design for Finding Extrasolar Planets

    OpenAIRE

    Vanderbei, R. J.; Kasdin, N. J.; Cady, E.

    2007-01-01

    One proposed method for finding terrestrial planets around nearby stars is to use two spacecraft--a telescope and a specially shaped occulter that is specifically designed to prevent all but a tiny fraction of the starlight from diffracting into the telescope. As the cost and observing cadence for such a mission will be driven largely by the separation between the two spacecraft, it is critically important to design an occulter that can meet the observing goals while flying ...

  11. 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...

  12. Relationship between anal symptoms and anal findings

    OpenAIRE

    Hans Georg Kuehn, Ole Gebbensleben

    2009-01-01

    Background: The frequencies and types of anal symptoms were compared with the frequencies and types of benign anal diseases (BAD). Methods: Patients transferred from GPs, physicians or gynaecologists for anal and/or abdominal complaints/signs were enrolled and asked to complete a questionnaire about their symptoms. Proctologic assessment was performed in the knee-chest position. Definitions of BAD were tested in a two year pilot study. Findings were entered into a PC immediately after the ass...

  13. 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 ...

  14. Finding Regression Outliers With FastRCS

    OpenAIRE

    Vakili, Kaveh; Schmitt, Eric

    2013-01-01

    The Residual Congruent Subset (RCS) is a new method for finding outliers in the linear regression setting. Like many other outlier detection procedures, RCS searches for a subset which minimizes a criterion. The difference is that the new criterion was designed to be insensitive to the outliers. RCS is supported by FastRCS, a fast regression and affine equivariant algorithm which we also detail. Both an extensive simulation study and two real data applications show that Fast...

  15. 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.

  16. Finding important sites in protein sequences

    OpenAIRE

    Peter J Bickel; 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...

  17. 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.

  18. 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.

  19. Finding mesoscale ocean structures with mathematical morphology

    International Nuclear Information System (INIS)

    The authors introduce a technique to aid in interpreting infrared satellite images of the North Atlantic Ocean Gulf Stream region. Present interpretive methods are largely manual, require significant effort, and are highly dependent on the interpreter's skill. The quasiautomated technique is based on mathematical morphology, specifically the image transformations of opening and closing, which are defined in terms of erosion and dilation. The implementation performs successive openings and closings at increasing thresholds until a stable division into objects and background is found. This method finds the North Wall of the Gulf Stream in approximately the same place as human analysts and another automated procedure, and does less smoothing of small irregularities than the other two methods. The North Wall is continuous and sharp except where obscured by clouds. Performance in locating warm-core eddies is also comparable to the other methods. However, the present procedure does not find cold-core rings well. The authors are presently investigating ways to reduce the effects of clouds and delete the unwanted water areas found by the method. They expect to be able to improve the cold-core eddy performance

  20. Comparison of photopeak integration methods

    International Nuclear Information System (INIS)

    Several methods for the calculation of gamma-ray photopeak areas have been compared for the case of a small peak on a high Compton background. 980 similar spectra were accumulated with a germanium detector using a weak 137Cs source to produce a peak at 662 keV on a Compton background generated by a 60Co source. A computer program was written to calculate the area of the 662 keV peak using the total- and partial-peak-area methods, a modification of Sterlinski's method, Loska's method and least-squares fitting of Gaussian peak shapes with linear and quadratic background. The precision attained was highly dependent on the number of channels used to estimate the background, and the best precision, about 9.5%, was obtained with the partial-peak-area method, the modified Sterlinski method and least-squares fitting with variable peak position, fixed peak width and linear background. The methods were also evaluated for their sensitivity to uncertainty in the peak centroid position. Considering precision, ease of use, reliability and universal applicability, the total-peak-area method using several channels for background estimation and the least-squares-fitting method are recommended. (orig.)

  1. 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)

  2. 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

  3. Imaging findings of avalanche victims

    Energy Technology Data Exchange (ETDEWEB)

    Grosse, Alexandra B.; Grosse, Claudia A.; Anderson, Suzanne [University Hospital of Berne, Inselspital, Department of Diagnostic, Pediatric and Interventional Radiology, Berne (Switzerland); Steinbach, Lynne S. [University of California San Francisco, Department of Radiology, San Francisco, CA (United States); Zimmermann, Heinz [University Hospital of Berne, Inselspital, Department of Trauma and Emergency Medicine, Berne (Switzerland)

    2007-06-15

    Skiing and hiking outside the boundaries remains an attractive wilderness activity despite the danger of avalanches. Avalanches occur on a relatively frequent basis and may be devastating. Musculoskeletal radiologists should be acquainted with these injuries. Fourteen avalanche victims (11 men and 3 women; age range 17-59 years, mean age 37.4 years) were air transported to a high-grade trauma centre over a period of 2 years. Radiographs, CT and MR images were prospectively evaluated by two observers in consensus. Musculoskeletal findings (61%) were more frequent than extraskeletal findings (39%). Fractures were most commonly seen (36.6%), involving the spine (14.6%) more frequently than the extremities (9.8%). Blunt abdominal and thoracic trauma were the most frequent extraskeletal findings. A wide spectrum of injuries can be found in avalanche victims, ranging from extremity fractures to massive polytrauma. Asphyxia remains the main cause of death along with hypoxic brain injury and hypothermia. (orig.)

  4. Adrenoleukodystrophy: CT and MRI findings

    International Nuclear Information System (INIS)

    A case of adrenoleukodystrophy (ALD) with CT and MRI findings is described. The CT scan showed low densities in the white matter of the parietal and occipital lobes. No calcifications were seen. Post-contrast CT showed an abnormal enhancement within the involved white matter. MRI showed changes of demyelination around the atria of the lateral ventricles bilaterally involving the posterior aspect of the cerebrum symmetrically. The posterior part of the posterior corpus callosum, splenium and pyramidal tracts also showed increased signal intensity. From a review of the literature, these findings are typical of the radiological changes seen in ALD. ALD can be diagnosed from typical history and biochemical changes as well as from CT and MRI findings. (orig.)

  5. CT findings of orbital pseudotumor

    International Nuclear Information System (INIS)

    To evaluate characteristics CT findings of orbital pseudotumor and to define differential points from other pathology, the authors retrospectively reviewed CT of 19 patients who were proven to have orbital pseudotumor by clinical course and, in some cases, biopsy. A variety of CT findings including extraocular muscle thickening (11 cases), streaky infiltration of retroorbital fat (11 cases), mass formation (10 cases), optic nerve thickening (6 cases), conjunctival thickening (5 cases), scleral thickening (4 cases), enlarged lacrimal gland (4 cases) and destruction of orbital bone (2 cases) were observed. Thickening of the anterior portion and irregular margin were characteristic findings of extraocular muscle and optic nerve lesions. Mass formation predominantly occurs in the anterior portion of the orbit. In most cases more than two orbital structures are involved by lesion

  6. 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

  7. 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.

  8. 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 trach 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

  9. CT findings of atrial myxoma

    Energy Technology Data Exchange (ETDEWEB)

    Tsuchiya, F.; Kohno, A.; Saitoh, R.; Shigeta, A.

    1984-04-01

    The computed tomographic (CT) appearance of six atrial myxomas was analyzed. Five of the myxomas were located in the left atrium and one was in the right atrium. The margin of the myxoma was at least slightly lobulated in five cases and the content was inhomogeneous in all. Calcification was demonstrated in three cases. The site of attachment of the myxoma was demonstrated by CT to be the arial septum in all cases. The CT finding correlated well with the operative findings. It is concluded that it is possible with CT to diagnose atrial myxoma by the location and nature of the intracardiac mass and to differentiate it from thrombus.

  10. 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

  11. Musculoskeletal Findings in Behcet's Disease

    OpenAIRE

    Bicer, Ali

    2011-01-01

    Behcet's disease is a multisystem disease characterized by recurrent oral and genital ulcers, relapsing uveitis, mucocutaneous, articular, gastrointestinal, neurologic, and vascular manifestations. Rheumatologic manifestations may also occur in Behcet's disease, and arthritis and arthralgia are the most common musculoskeletal findings followed by enthesopathy, avascular necrosis, myalgia, and myositis. Although the main pathology of Behcet's disease has been known to be the underlying vasculi...

  12. Help me Find my Relationship!

    Science.gov (United States)

    2012-11-12

    In this lesson, students will investigate the relationship between angles when parallel lines are cut by a transversal. Students will identify angles, find angle measures, and they will use the free application GeoGebra (see download link under Suggested Technology) to provide students with a visual representation of angles relationships.

  13. Triangles: Finding Interior Angle Measures

    Science.gov (United States)

    2012-11-25

    In this lesson plan, students will start with a hands-on activity and then experiment with a GeoGebra-based computer model to investigate and discover the Triangle Angle Sum Theorem. Then they will use the Triangle Angle Sum Theorem to write and solve equations and find missing angle measures in a variety of examples.

  14. Milnacipran: recent findings in depression

    OpenAIRE

    Guest editors: Stuart Montgomery (London; UK); Mike Briley (Castres; France

    2010-01-01

    EDITORIAL FOREWORDPage 1   Milnacipran: recent findings in depression Stuart Montgomery (London, UK) and Mike Briley (Castres, France) REVIEWSPage 3   Suicidality: risk factors and the effects of antidepressants. The example of parallel reduction of suicidality and other depressive symptoms during treatment with the SNRI, milnacipran Philippe Courtet (Montpellier, France)Page 9   Treatment of patients with comorbid depres...

  15. 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)

  16. Finding Geography Using Found Poetry

    Science.gov (United States)

    Foster, Ellen J.

    2012-01-01

    Functional literacy is important in both English/language arts and geography. Using the "found poetry" strategy, students will summarize a piece of text, identify main ideas and find geographic connections. While using young adult literature is a great way to incorporate geography into English/language arts classroom, understanding of geography…

  17. Pigmented villonodular synovitis: MR findings

    International Nuclear Information System (INIS)

    Pigmented villonodular synovitis is an un-common lesion of the synovium that typically involves diffusely the knee. We present the MR findings of two cases involving the knee,one of them diffuse and the other one localized in the supra patellar bursa. (Author)

  18. 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.

  19. 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

  20. 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 ontext, 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

  1. Behavioral Couples Therapy for Substance Abuse: Rationale, Methods, and Findings

    OpenAIRE

    Fals-Stewart, William; Timothy J. O’Farrell; 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...

  2. Finding the Most Distant Quasars Using Bayesian Selection Methods

    CERN Document Server

    Mortlock, Daniel

    2014-01-01

    Quasars, the brightly glowing disks of material that can form around the super-massive black holes at the centres of large galaxies, are amongst the most luminous astronomical objects known and so can be seen at great distances. The most distant known quasars are seen as they were when the Universe was less than a billion years old (i.e., $\\sim\\!7%$ of its current age). Such distant quasars are, however, very rare, and so are difficult to distinguish from the billions of other comparably-bright sources in the night sky. In searching for the most distant quasars in a recent astronomical sky survey (the UKIRT Infrared Deep Sky Survey, UKIDSS), there were $\\sim\\!10^3$ apparently plausible candidates for each expected quasar, far too many to reobserve with other telescopes. The solution to this problem was to apply Bayesian model comparison, making models of the quasar population and the dominant contaminating population (Galactic stars) to utilise the information content in the survey measurements. The result wa...

  3. 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...

  4. Neuroradiological methods and findings on presurgical evaluation of epileptic children

    International Nuclear Information System (INIS)

    Epilepsy in childhood is often caused by morphological abnormalities and is frequently pharmacoresistant. Therefore it represents a challenge to the neuroradiologist because early and accurate diagnosis of abnormal morphology is the basis for planning surgical intervention with a high change of controlling seizures and a low risk of complications. Both morphological (radiography, CT, MRI and angiography) and functional examinations [intracarotid amobarbital test (IAT)] are essential parts of the presurgical evaluation. In most cases MRI has proved to be most sensitive in detecting lesions except for some calcifications. Routine protocols for brain examinations are not sufficient, missing about 22% of lesions. Therefore a refined MRI and CT protocol is proposed. Even in very young children IAT can be performed at very low risk; these tests contribute highly valuable information about hemispheric dominance and other functions in more than 80% of procedures that is indispensable if postoperative neurological and neuropsychological deficits are to be avoided. (orig.)

  5. Unexpected Finding Suggests Method for Controlling Pollen Dispersal

    Science.gov (United States)

    Two studies on the genetic inheritance of a wheat genomic DNA fragment in transgenic corn conclude that this DNA fragment is inherited maternally because it functions as a pollen specific gametocide. The authors of these studies illustrate that this transgene can but used to control transfer of a s...

  6. The Heritability of Eating Disorders: Methods and Current Findings

    OpenAIRE

    Thornton, Laura M.; Mazzeo, Suzanne E.; Bulik, Cynthia M.

    2011-01-01

    Family, twin, and adoption studies of anorexia nervosa (AN), bulimia nervosa (BN), binge-eating disorder (BED), and the proposed purging disorder presentation (PD) have consistently demonstrated that genetic factors contribute to the variance in liability to eating disorders. In addition, endophenotypes and component phenotypes of eating disorders have been evaluated and provide further insight regarding genetic factors influencing eating disorders and eating disorder diagnostic criteria. Man...

  7. 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…

  8. Advancing Findings, Theories, and Methods Concerning Children with Disabilities.

    Science.gov (United States)

    Hodapp, Robert M.

    2001-01-01

    Describes as advances of the Hauser-Cram et al. study increasing basic information about children with disabilities and their families, showing a combined organismic-contextual developmental perspective, and operationalizing tenets of developmental psychopathology. Considers as limitations: the role of etiology, the need to reconceptualize…

  9. LEGO Model of Kepler Planet-finding Method

    Science.gov (United States)

    This model aims to help illustrate the purpose and methodology of NASA's Kepler mission. It includes (1) a hand-cranked or motorized orrery (moving model of a planet system) made of LEGO parts, (2) a light sensor representing the Kepler photometer, (3) computer software for graphing light curves, representing Kepler Science Office - data analysis. A light bulb at the center of the orrery represents a star, and as planets in the model pass between the star and the light sensor, dips in the computer graph light curve happen in real time.

  10. MDCT and virtual bronchoscopy findings of tracheabronchomegaly

    International Nuclear Information System (INIS)

    Full text: Introduction: Tracheabronchomegaly (TBM) or Mounier-Kuhn syndrome is a rare syndrome which is characteristic with bronchiectasis, recurrent respiratory tract infections with expansion of large bronchi. Respiration function test, imaging methods and bronchoscopy are used for the diagnosis. Objective and tasks: We aimed to evaluate the findings of virtual bronchoscopy and MDCT of 21 years-old male patient who has complaint of recurrent lower respiratory tract infection. Materials and methods: We perform thorax CT and virtual bronchoscopy with 320-detector multidetector computer tomography. Results: Diameter of the trachea at the carina level was 30.5 mm, in turn the diameters of the right and left main bronchi were 18 mm and 17 mm. There were moderate bronchiectasis in the middle and lower zones. Conclusion: MDCT and fiberoptic bronchoscopy have been used for the diagnosis of TBM. In such cases, virtual bronchoscopy is non invasive method for demonstrating luminal pathologies

  11. MRI findings in acute Hendra virus meningoencephalitis

    Energy Technology Data Exchange (ETDEWEB)

    Nakka, P.; Amos, G.J. [Department of Diagnostic Radiology, Princess Alexandra Hospital, Woolloongabba, Qld 4102 (Australia); Saad, N., E-mail: nivena100@hotmail.com [Department of Diagnostic Radiology, Princess Alexandra Hospital, Woolloongabba, Qld 4102 (Australia); Jeavons, S. [Department of Diagnostic Radiology, Princess Alexandra Hospital, Woolloongabba, Qld 4102 (Australia)

    2012-05-15

    Aim: To describe serial changes in brain magnetic resonance imaging (MRI) in acute human infection from two outbreaks of Hendra virus (HeV), relate these changes to disease prognosis, and compare HeV encephalitis to reported cases of Nipah virus encephalitis. Materials and methods: The MRI images of three human cases (two of which were fatal) of acute HeV meningoencephalitis were reviewed. Results: Cortical selectivity early in the disease is evident in all three patients, while deep white matter involvement appears to be a late and possibly premorbid finding. This apparent early grey matter selectivity may be related to viral biology or ribavirin pharmacokinetics. Neuronal loss is evident at MRI, and the rate of progression of MRI abnormalities can predict the outcome of the infection. In both fatal cases, the serial changes in the MRI picture mirrored the clinical course. Conclusion: This is the first comprehensive report of serial MRI findings in acute human cerebral HeV infection from two outbreaks. The cortical selectivity appears to be an early finding while deep white matter involvement a late, and possibly premorbid, finding. In both fatal cases, the serial changes in MRI mirrored the clinical course.

  12. MRI findings in acute Hendra virus meningoencephalitis

    International Nuclear Information System (INIS)

    Aim: To describe serial changes in brain magnetic resonance imaging (MRI) in acute human infection from two outbreaks of Hendra virus (HeV), relate these changes to disease prognosis, and compare HeV encephalitis to reported cases of Nipah virus encephalitis. Materials and methods: The MRI images of three human cases (two of which were fatal) of acute HeV meningoencephalitis were reviewed. Results: Cortical selectivity early in the disease is evident in all three patients, while deep white matter involvement appears to be a late and possibly premorbid finding. This apparent early grey matter selectivity may be related to viral biology or ribavirin pharmacokinetics. Neuronal loss is evident at MRI, and the rate of progression of MRI abnormalities can predict the outcome of the infection. In both fatal cases, the serial changes in the MRI picture mirrored the clinical course. Conclusion: This is the first comprehensive report of serial MRI findings in acute human cerebral HeV infection from two outbreaks. The cortical selectivity appears to be an early finding while deep white matter involvement a late, and possibly premorbid, finding. In both fatal cases, the serial changes in MRI mirrored the clinical course.

  13. Interesting bone scans - unusual findings

    International Nuclear Information System (INIS)

    A 59-year-old female with carcinoma of the colon and known liver metastatic disease was referred for bone scan to evaluate for bone metastases. Although no bone metastases were found, there was abnormal uptake noted in the liver corresponding to a metastatic calcified lesion. The only other findings were of degenerative disease in the cervical spine, right shoulder and small joints of the hands. A 69-year-old male with carcinoma of the prostate and right side low back pain was referred for bone scan. No focal abnormalities to suggest metastatic disease were identified; findings within the cervical spine, lumber spine and knees were presumed secondary to degenerative disease. Intermittent pain persisted and the patient was referred for a repeat bone scan six months later. Previous scan findings of degenerative disease and no metastatic disease were confirmed; however, closer inspection revealed an enlarged right kidney with significant retention of tracer in the pelvicalyceal system suggesting possible obstruction. A Retrograde pyelogram was performed, and no obvious obstruction demonstrated. As bone scan findings were very suggestive of obstruction, a DTPA scan with lasix was performed showing a dilated right collecting system with no functional obstruction. Given the degree of dilation, it is possible that the patient experiences intermittent PUJ obstruction causing his symptoms. A 33-year-old male with insulin dependent diabetes mellitus and viral arthritis was refeetes mellitus and viral arthritis was referred for a bone scan. A three phase revealed increased uptake in the region of the knee and leR proximal tibia. Delayed whole body images revealed multiple focal areas of osteoblastic activity in the leR tibia. Abnormal uptake was also seen in the upper third of the leR femur. The remainder of the skeletal survey was normal. X-ray correlation of the leR tibia and femoral findings was undertaken. Combinating unilateral changes on bone scan and X-ray although very suggestive of sclerotic polyostotic fibrous dysplasia. Three cases with interesting and unusual bone scan findings assisted in further management and treatment of patients

  14. New technology for gas finding

    International Nuclear Information System (INIS)

    This paper reports that finding costs for natural gas in the U.S. were more than halved in real terms from 94 cents/Mcf in 1983 to 44 cents in 1989. A number of industry analysts and oil company executives recently have suggested that technology improvements contributed significantly to this improvement. This claim is an especially important one because its proponents often use it to support the view that the gas glut in the U.S. will persist. In this view, new technology will push finding costs lower and help sustain deliverability, further prolonging the bubble. Managers who are convinced of this position will want to invest in the people, software, and equipment that is supposed to be behind this improved performance. But they also are more likely to defer drilling and acquisitions of companies or producing leases to avoid adding to the supply overhang

  15. CT findings of peritoneal mesothelioma

    International Nuclear Information System (INIS)

    The peritoneal mesothelioma is a rare neoplasm which arises from the peritoneal lining of the abdomen, tending to spread along the peritoneal cavity and to invade abdominal organs. Authors report the CT findings of 4 patients with histologically proven peritoneal mesothelioma seen at Dongsan Medical Center, School of Medicine, Keimyung University. None of them had a history of exposure to asbestos and no clear etiologic factor could be determined in any patient. CT showed peritoneal and mesenteric thickenings in all cases, omental thickenings in 3 cases, peritoneal nodules, mesenteric masses or omental masses in 2 cases each other, bowel wall involvement in 1 case, and disproportionally small ascites in 2 cases. Distant hematogenous metastases to the liver and retroperitoneal lymph nodes were seen in 1 case. Our experience with 4 peritoneal mesotheliomas as well as a review of the recent imaging literature shows excellent correlation between computed tomography and the operitoneoscopic findings

  16. CT findings of peritoneal mesothelioma

    Energy Technology Data Exchange (ETDEWEB)

    Woo, Young Hoon; Oh, Yeon Hee; Kim, Hong; Kim, Jung Sik; Woo, Seong Ku; Kim, Ok Bae; Joo, Yang Goo [Keimyuung University College of Medicine, Daegu (Korea, Republic of)

    1990-04-15

    The peritoneal mesothelioma is a rare neoplasm which arises from the peritoneal lining of the abdomen, tending to spread along the peritoneal cavity and to invade abdominal organs. Authors report the CT findings of 4 patients with histologically proven peritoneal mesothelioma seen at Dongsan Medical Center, School of Medicine, Keimyung University. None of them had a history of exposure to asbestos and no clear etiologic factor could be determined in any patient. CT showed peritoneal and mesenteric thickenings in all cases, omental thickenings in 3 cases, peritoneal nodules, mesenteric masses or omental masses in 2 cases each other, bowel wall involvement in 1 case, and disproportionally small ascites in 2 cases. Distant hematogenous metastases to the liver and retroperitoneal lymph nodes were seen in 1 case. Our experience with 4 peritoneal mesotheliomas as well as a review of the recent imaging literature shows excellent correlation between computed tomography and the operitoneoscopic findings.

  17. CT-findings in ARDS

    International Nuclear Information System (INIS)

    The CT features of 28 patients with ARDS are described. Diffuse lung consolidation, multifocal patchy involvement and lobar or segmental disease were observed. Large lung cysts as well as small cysts producing a 'swiss-cheese' appearance of the parenchyma, were detected. These findings were not regularly appreciated on chest radiographs. The overall mortality of our 28 patients was 72.7% (22 out 28). Patients with lung cysts showed a trend toward higher mortality (87.5% or 13 out 16). Other unexpected findings were basilar lung abscesses and an empyema. In 15 out of 28 patients, CT scans provided additional information, not obvious on bedside chest radiographs and led to a change in management in five patients. (orig.)

  18. Radioreklamen skal finde sine ben

    Directory of Open Access Journals (Sweden)

    Sigurd Bennike

    1989-08-01

    Full Text Available Den 1. august 1988 startede radioreklamerne i Danmark uden nævneværdig opmærksomhed fra hverken pressen eller medieforskerne. Annoncørerne, reklamebureauerne og de store radiostationer har haft lidt svært ved at finde hinanden. Og heller ikke nemt ved at finde ud af, hvem der skulle producere reklamerne og hvordan sådan nogle skal lyde på dansk. Som det indirekte fremgår af denne artikel, så er det svært at få tal ud af branchen. - Men et kvalificeret gæt lyder på, at der er omsat for mellem 20 og 40 millioner kroner på de første måneder, koncentreret på mindre end 50 af de 237 nærradiosendetilladelser. De radiostationer der vælger at sende reklamer, skal betale 10% af deres omsætning til en særlig radiofond, hvis midler deles ud til de græsrodsradioer, som ikke kan eller vil skaffe sig reklameindtægter.

  19. Finding customers through social media

    OpenAIRE

    Piironen, Petra

    2011-01-01

    The research is a marketing study specialised in marketing in social media executed for Kuortane Sports Institute. The research was made as a case study concentrating on one of Kuortane Sports Institute’s centres, Kuortane High Performance Training Centre and its customer group of international javelin throwers and trainers. The aim of the study was to find answer the research question how can Kuortane High Performance Training Centre utilise social media in order to support their busin...

  20. Angiographic findings in tumoral calcinosis.

    Science.gov (United States)

    Neeman, Ziv; Wood, Bradford J

    2003-01-01

    Tumor calcinosis is uncommon, typically manifesting as paraarticular, extracapsular soft tissue deposits containing amorphous calcium phosphate and calcium carbonate, with associated hydroxyapatite crystal. CT and MRI are the primary diagnostic radiological tools evaluating these lesions. Primary treatment is early surgical excision with wide margins, as there is a high recurrence rate. We describe the angiographic findings in tumoral calcinosis, demonstrating hypervascularity beyond the calcified mass periphery. Exact margin definition with angiography may influence management and surgical approach. PMID:12727056

  1. Ultrasonographic findings of appendiceal mucocle

    International Nuclear Information System (INIS)

    The authors analyse the ultrasonographic findings of 10 cases of appendiceal mucocele retrospectively. In a total of 10 cases, 6 cases showed only cystic masses with posterior reinforcement. The remaining 4 cases showed internal echoes in the cystic masses. Differential diagnosis of mucocele from periappendiceal abscess is not possible in ultrasound. The possibility of mucocele should be considered if cystic mass right lower quadrant abdomen is observed in ultrasound.

  2. Ultrasonographic findings of appendiceal mucocle

    Energy Technology Data Exchange (ETDEWEB)

    Park, Kyu Il; Choi, Ji Bai; Lee, Il Sung; Ko, Young Tae; Lim, Jae Hoon [Kyung Hee University Hospital, Seoul (Korea, Republic of)

    1986-06-15

    The authors analyse the ultrasonographic findings of 10 cases of appendiceal mucocele retrospectively. In a total of 10 cases, 6 cases showed only cystic masses with posterior reinforcement. The remaining 4 cases showed internal echoes in the cystic masses. Differential diagnosis of mucocele from periappendiceal abscess is not possible in ultrasound. The possibility of mucocele should be considered if cystic mass right lower quadrant abdomen is observed in ultrasound.

  3. Finding two-dimensional peaks

    International Nuclear Information System (INIS)

    Two-dimensional generalization of the original peak finding algorithm suggested earlier is given. The ideology of the algorithm emerged from the well-known quantum mechanical tunneling property which enables small bodies to penetrate through narrow potential barriers. We merge this 'quantum' ideology with the philosophy of Particle Swarm Optimization to get the global optimization algorithm which can be called Quantum Swarm Optimization. The functionality of the newborn algorithm is tested on some benchmark optimization problems

  4. Dermoscopy Findings of Pseudolymphomatous Folliculitis

    OpenAIRE

    Fujimura, Taku; Hidaka, Takanori; Hashimoto, Akira; Aiba, Setsuya

    2012-01-01

    Pseudolymphomatous folliculitis (PLF), which clinically mimicks cutaneous lymphoma, is a rare manifestation of cutaneous pseudolymphoma and cutaneous lymphoid hyperplasia. Here, we report on a 45-year-old Japanese woman with PLF. Dermoscopy findings revealed prominent arborizing vessels with small perifollicular and follicular yellowish spots and follicular red dots. A biopsy specimen also revealed dense lymphocytes, especially CD1a+ cells, infiltrated around the hair follicles. Without any a...

  5. CT findings of sternal masses

    Energy Technology Data Exchange (ETDEWEB)

    Bae, Jae Ik; Choi, Yo Won; Kim, Bong Soo; Jeon, Seok Chol; Seo, Hueng Seok; Hahm, Chang Kok; Park, Choong Ki; Joo, Kyung Bin [Hanyang Univ. College of Medicine, Seoul (Korea, Republic of)

    1999-09-01

    To describe and characterize the CT findings of the sternal masses. We retrospectively reviewed the medical records, pathologic reports, and CT findings of 16 patients whose chest CT revealed sternal masses. Two primary tumors were found, namely chondrosarcomas. Twelve metastatic tumors had arisen were from lung cancer (n = 4), breast cancer (n = 3), hepatoma (n 2), osteosarcoma (n = 1), carotid body paraganglioma (n = 1), and immature sacrococcygeal teratoma (n = 1). Other were Castleman's disease (n = 1) and inflammatory pseudotumor (n = 1). Chondrosarcomas were large expansile osteolytic masses showing a variable degree of cortical breakthrough and containing punctuate chondroid calcifications. Most sternal metastases (83 %) were located in the manubrium and were accompanied by metastasis in other bones (83 %). Metastatic tumors were nonspecific osteolytic soft tissue masses showing homogeneous or inhomogeneous enhancement, except for those which arose from an osteosarcoma and a lung cancer, and showed osteoblastic lesions. Castleman's disease was seen as an ill-defined enhanced soft tissue mass involving the sternum and adjacent soft tissue. Inflammatory pseudotumor appeared as an infiltrating lesion around the sternoclavicular joint and was accompanied by sclerosis and the erosion of opposing sternal and clavicular ends. Most of the sternal masses are due to malignant neoplasms, among which metastatic tumors are more common than primary ones. Metastatic tumors affect the manubrium more commonly than the body portion, and most also affect other bones in the thorax. CT findings of metastatic tumors are non-specific and thus do not suggest their origin. Non-neoplastic masses are not readily differentiated from malignant tumors on the basis of CT findings alone and require pathological confirmation.

  6. Finding related functional neuroimaging volumes

    DEFF Research Database (Denmark)

    Nielsen, Finn Årup; Hansen, Lars Kai

    2004-01-01

    We describe a content-based image retrieval technique for finding related functional neuroimaging experiments by voxelization of sets of stereotactic coordinates in Talairach space, comparing the volumes and reporting related volumes in a sorted list. Voxelization is accomplished by convolving each coordinate with a Gaussian kernel. The scheme allows us to compare experiments represented as either lists of coordinates or volumes, and we introduce alternative entrances to databases by image-based indices constructed via novelty measures and singular value decomposition.

  7. Imaging findings of measles pneumonia in adults

    International Nuclear Information System (INIS)

    Objective: To illustrate the chest radiography and MSCT findings of measles pneumonia in adults. Methods: One hundred and sixty three measles patients underwent chest radiography, MSCT was performed in 3 of them. Measles pneumonia was confirmed in 10 patients (6.13%). Results: Eight of 10 patients had abnormal appearances in initial chest radiography. The characteristic chest radiographic findings were ground-glass opacities (n=6) and bronchial wall thickening (n=2). MSCT showed bilateral multiple ground-glass opacities in 1 patient, unilateral patchy ground-glass opacities with lobular distribution in the right upper lung in 2 patients. Conclusions: Familiarizing with radiographic and MSCT appearances of measles pneumonia in adults is very important for the differential diagnosis and appropriate management of measles pneumonia. Normal initial chest radiography cannot exclude the involvement of the lungs. (authors)

  8. Position finding using simple Doppler sensors

    Directory of Open Access Journals (Sweden)

    S. Schelkshorn

    2007-06-01

    Full Text Available An increasing number of modern applications and services is based on the knowledge of the users actual position. Depending on the application a rough position estimate is sufficient, e. g. services in cellular networks that use the information about the users actual cell. Other applications, e. g. navigation systems use the GPS-System for accurate position finding. Beyond these outdoor applications a growing number of indoor applications requires position information. The previously mentioned methods for position finding (mobile cell, GPS are not usable for these indoor applications.

    Within this paper we will present a system that relies on the simultaneous measurement of doppler signals at four different positions to obtain position and velocity of an unknown object. It is therefore suiteable for indoor usage, extendig already existing wireless infrastructure.

  9. Social risk perception: recent findings in Spain

    International Nuclear Information System (INIS)

    The purpose of this paper is to present our main results from a survey carried out in Spain in the context of social risk perception. This survey is included in a broad project (PRISP) sponsored by the UE and the national Civil Protection Service, and carried out simultaneously in three countries: Spain, Italy and UK. The project combined qualitative and quantitative assessment methods, although only survey results are presented here. A random sample of 600 subjects from two different Spanish communities close to a COMAH chemical site was selected for the research. Main findings regarding, differential perception between both community populations, sex differences, and 'bias perception' of risks among others have been achieved. Main dimensions were obtained by multidimensional scaling and Factor Analysis. Dimensions reported here are similar to the usual findings from the psychometric paradigm. (authors)

  10. Studying Emerge : Findings from an Event Ethnography

    DEFF Research Database (Denmark)

    Davies, Sarah R.; Selin, Cynthia

    2015-01-01

    The Emerge event, held in Tempe, AZ in March 2012, brought together a range of scientists, artists, futurists, engineers and students in order to experiment with innovative methods for thinking about the future. These methodological techniques were tested through nine workshops, each of which made use of a different format; Emerge as a whole, then, offered an opportunity to study a diverse set of future-oriented engagement practices. We conducted an event ethnography, in which a team of 11 researchers collaboratively developed accounts of the practices at play within Emerge and its workshops. In this article we discuss findings from this ethnography, using our data both to describe the techniques used within Emerge and to analyse key patterns which occurred around those techniques. As we close we reflect on the implications of these findings for practice, suggesting ways in which our results can help hone the tools and techniques of future studies.

  11. Abdominal wall hernias complications: CT findings

    International Nuclear Information System (INIS)

    Full text: Introduction: Most AWHs are asymptomatic. However, some may develop acute complications that necessitate emergent surgery. Objectives and tasks: The purpose of this presentation is to demonstrate useful points in Computed Tomography (CT) images that could help the young radiologist in the emergency setting for a prompt diagnosis of a complicated abdominal wall hernia. Material and methods: CT images from 52 patients referred from the Emergency Department during the last three years for an abdominal CT scan and diagnosed with an abdominal wall hernia were retrospectively studied. Results: In this presentation we illustrate in images and corresponding schematic diagrams the characteristic imaging findings in the most common complications (eg, bowel obstruction secondary to the hernia, strangulation -ischemia caused by a compromised blood supply- and incarceration). Conclusion: Early diagnosis of a complicated hernia is feasible with CT potentially improving patient outcome by preserving bowel viability. Thus, knowledge of imaging findings that suggest hernia complications is very important

  12. Studying Emerge : Findings from an event ethnography

    DEFF Research Database (Denmark)

    Davies, Sarah Rachael; Selin, Cynthia

    2015-01-01

    The Emerge event, held in Tempe, AZ in March 2012, brought together a range of scientists, artists, futurists, engineers and students in order to experiment with innovative methods for thinking about the future. These methodological techniques were tested through nine workshops, each of which made use of a different format; Emerge as a whole, then, offered an opportunity to study a diverse set of future-oriented engagement practices. We conducted an event ethnography, in which a team of 11 researchers collaboratively developed accounts of the practices at play within Emerge and its workshops. In this article we discuss findings from this ethnography, using our data both to describe the techniques used within Emerge and to analyse key patterns which occurred around those techniques. As we close we reflect on the implications of these findings for practice, suggesting ways in which our results can help hone the tools and techniques of future studies. © 2014 Elsevier Ltd. All rights reserved.

  13. Painful Heel: MR Imaging Findings

    Directory of Open Access Journals (Sweden)

    Babak Sanei

    2010-05-01

    Full Text Available Heel pain is a common and frequently disabling clinical complaint that may be caused by a broad spectrum of osseous or soft-tissue disorders. "nThese disorders are classified on the basis of anatomic origin and predominant location of heel pain to foster a better understanding of this complaint. The disorders include plantar fascial lesions (fasciitis, rupture, fibromatosis, xanthoma, tendinous (tendonitis, tenosynovitis, osseous lesions (fractures, bone bruises, osteomyelitis, tumors, bursal lesions (retrocalcaneal bursitis, retroachilleal bursitis, tarsal tunnel syndrome, and heel plantar fat pad abnormalities. With its superior soft-tissue contrast resolution and multiplanar capability, magnetic resonance (MR imaging can help determine the cause of heel pain and help assess the extent and severity of the disease in ambiguous or clinically equivocal cases. Careful analysis of MR imaging findings and correlation of these findings with patient history and findings at physical examination can suggest a specific diagnosis in most cases. The majority of patients with heel pain can be successfully treated conservatively, but in cases requiring surgery (eg, plantar fascia rupture in competitive athletes, deeply infiltrating plantar fibromatosis, masses causing tarsal tunnel syndrome, MR imaging is especially useful in planning surgical treatment by showing the exact location and extent of the lesion

  14. MRI findings in bipartite patella

    Energy Technology Data Exchange (ETDEWEB)

    Kavanagh, Eoin C. [University of Pittsburgh Medical Centre, Department of Radiology, Pittsburgh, PA (United States); Zoga, Adam; Omar, Imran [Thomas Jefferson University Hospital, Department of Radiology, Philadelphia, PA (United States); Ford, Stephanie; Eustace, Stephen [Cappagh National Orthopaedic Hospital, Department of Radiology, Dublin (Ireland); Schweitzer, Mark [Hospital for Joint Disease, Orthopedic Institute, Department of Radiology, New York, NY (United States)

    2007-03-15

    Bipartite patella is a known cause of anterior knee pain. Our purpose was to detail the magnetic resonance imaging (MRI) features of bipartite patella in a retrospective cohort of patients imaged at our institution. MRI exams from 53 patients with findings of bipartite patella were evaluated to assess for the presence of bone marrow edema within the bipartite fragment and for the presence of abnormal signal across the synchondrosis or pseudarthrosis. Any other significant knee pathology seen at MRI was also recorded. We also reviewed 400 consecutive knee MRI studies to determine the MRI prevalence of bipartite patella. Of the 53 patients with bipartite patella 40 (75%) were male; 35 (66%) had edema within the bipartite fragment. Of the 18 with no edema an alternative explanation for knee pain was found in 13 (72%). Edema within the bipartite fragment was the sole finding in 26 of 53 (49%) patients. Bipartite patella was seen in 3 (0.7%) of 400 patients. In patients with bipartite patella at knee MRI, bone marrow edema within the bipartite fragment was the sole finding on knee MRI in almost half of the patients in our series. (orig.)

  15. MRI findings in bipartite patella

    International Nuclear Information System (INIS)

    Bipartite patella is a known cause of anterior knee pain. Our purpose was to detail the magnetic resonance imaging (MRI) features of bipartite patella in a retrospective cohort of patients imaged at our institution. MRI exams from 53 patients with findings of bipartite patella were evaluated to assess for the presence of bone marrow edema within the bipartite fragment and for the presence of abnormal signal across the synchondrosis or pseudarthrosis. Any other significant knee pathology seen at MRI was also recorded. We also reviewed 400 consecutive knee MRI studies to determine the MRI prevalence of bipartite patella. Of the 53 patients with bipartite patella 40 (75%) were male; 35 (66%) had edema within the bipartite fragment. Of the 18 with no edema an alternative explanation for knee pain was found in 13 (72%). Edema within the bipartite fragment was the sole finding in 26 of 53 (49%) patients. Bipartite patella was seen in 3 (0.7%) of 400 patients. In patients with bipartite patella at knee MRI, bone marrow edema within the bipartite fragment was the sole finding on knee MRI in almost half of the patients in our series. (orig.)

  16. CT findings of gallbladder perforation

    Energy Technology Data Exchange (ETDEWEB)

    Seong, Su Ok; Lee, Young Ju; Shim, Jae Chan; Kim, Ho Kyun [Seoul Paik Hospital, Inje University, Seoul (Korea, Republic of)

    1995-08-15

    To evaluate the usefulness in diagnosing the gallbladder perforation. CT scans of surgically proved 11 cases of gallbladder perforation were retrospectively reviewed. CT findings analyzed were luminal diameter of GB, GB wall thickness and configuration, presence or absence of fluid collection in the pericholecystic or intraperitoneal space, and observation of pericholecystic anatomic structures. All patients underwent cholecystectomy, and surgical findings were also compared. The GB was distended in 6 cases(55% with a range of 4.0-7.5 cm, mean: 5.2 cm). GB wall was thickened in most cases(9/11, 82%) with homogeneous(n = 7) or inhomogeneous(n = 2) enhancement. At the sites of perforation, focal defect or contour bulging was seen in the GB wall in 3 cases. In 2 cases with gangrene, GB wall showed loss of normal contour with mottled contrast enhancement. Pericholecystic or intraperitoneal fluid collection was noted in 9 cases(82%), especially in the region of perforation. In all cases, there was evidence of diffuse infiltration in the pericholecystic space, omentum or mesentery. Other findings included cholecystoenteric fistula in 1 case, and intrahepatic or intraperitoneal abscess formation in 2 cases. CT is useful in correct diagnosis of gallbladder perforation.

  17. 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.

  18. Finding Semantic Relationship among Associated Medical Terms

    Directory of Open Access Journals (Sweden)

    Muhammad Waqas

    2012-06-01

    Full Text Available Romania The literature of medicine and medicinal data is growing specialized and increasing by every day. Most of the data is contained by the journal of medicines and biology which makes this type of textual mining a central and core problem. Finding disease-medicine relationships requires laborious examination of hundreds of possible candidate heterogeneous factors. Most of the peoples face serious problems in extracting and finding useful information to access the clinical support from the currently available search engines and other tools, thus there should have some ability to identify the relationship between disease and other relevant factors which could support clinical diagnosis. In the paper, we are presenting a methodology for extracting useful information from Medline papers. The system tries to identify the relationship of an active disease and extract relevant medicine for the patient automatically. The core objective of proposed system is to find out or extracts only those documents that user is looking from a huge repository of documents or some other collection of facts and figures. The proposed method extracts some useful and interesting keywords that reveal sentences containing our desired task patterns. After finding the regularities of these patterns based on specific keywords, we apply the techniques of our system and mined semantic relationship. Our findings got more than 20 such keyword frequently produced relevant information. Proposed techniques give multiple medicines proposed by domain experts. The choice for proposed medicines are ranked on the basis of frequency and also based on the experience of different surveys performed by the authors in their papers.

  19. Gamma graphic findings in giant hepatic hemangioma

    International Nuclear Information System (INIS)

    The aim of the present work is to describe gamma graphic findings in patients with giant hepatic hemangiomas, when evaluated with 99mTc red blood cell (RBC) imaging. Three patients with clinical suspicion of giant hepatic hemangiomas, who had had, ultrasound and computed tomography were studied with RBC using in vivo labelling with pyrophosphate. All cases had dynamic and static views. All cases showed hypoperfusion in dynamics views and over perfusion in delayed studies. Surgery confirmed diagnosis in two cases. 99mTc RBC is a good method for diagnosis of giant hepatic hemangioma, which generally needs surgical treatment. (Authors). 24 refs., 2 figs

  20. Finding the Fermat point via analysis

    OpenAIRE

    Ye, Luqing

    2014-01-01

    Let $P_1,P_2,P_3$ be three given points in $\\mathbf{R}^2$, and $P$ be an arbitrary point in $\\mathbf{R}^2$. The classical Fermat's problem to Torricelli asks for the location of the point $P$ such that $|PP_1|+|PP_2|+|PP_3|$ is a minimum. There exist several elegant geometrical solutions in the literature.In this note, we consider finding the Fermat point by using methods in advanced calculus. The main tools we use are the extreme value theorem,Fermat's theorem, and the inte...

  1. MR findings of eosinophilic granuloma

    International Nuclear Information System (INIS)

    To describe the MR findings for the three phases of eosinophilic granuloma, as defined by Mirra's conventional radiographic criteria. Eighteen lesions in 14 patients with proven eosinophilic granuloma were retrospectively analyzed. Among this total, three vertebral lesions were excluded, and the remaining is were classified as early, middle, or late phase on the basis of Mirra's radiographic criteria. For each phase, we compared MR findings with regard to signal intensity, homogeneity, contrast enhancement, perilesional marrow edema, and soft tissue change. For the three vertebral lesions excluded because the application of radiographic criteria was difficult, MR findings for paravertebral soft tissue reaction and degree of cord compression were compared. Of the fifteen cases classified, eight were early phase, five were mid phase, and two were late phase. During each phase, all lesions except one, as seen on T1-weighted images(T1WI), showed iso-signal intensity. On T2WI, all lesions showed high signal intensity. Contrast study demonstrated marked contrast enhancement. Thus, no remarkable differences were found in the signal intensity degree of contrast enhancement of each phase. With regard to heterogeneity, this was demonstrated in most early phase lesions, reflecting necrosis and hemorrhage of those lesions. Soft tissue swelling was more severe during the early phase than the mid or late phase, but marrow edema was similar in each of the three phase. One of three pin each of the three phase. One of three patients with vertebraplana showed para-vertebral soft tissue swelling and cord compression, but this was not seen in the two other cases. For evalvating the extent of eosinophilic granuloma and its relationship with surrounding structures, MRI was superior to conventional radiography. During the early phase of the disease, lesions showed greater inhomogeneity and more aggressive soft tissue reaction than during the mid and late phase.The use of MRI for the evalvation of eosinophilic granuloma can help decide a therapeutic plan of action and follow up evaluation

  2. Neurological Findings in Myeloproliferative Neoplasms

    Directory of Open Access Journals (Sweden)

    Semra Paydas

    2013-04-01

    Full Text Available Myeloproliferative neoplasms (MPN arise from genetic deficiencies at the level of pluripotent stem cells. Each of these neoplasms is a clonal stem cell disorder with specific phenotypic, genetic and clinical properties. Age is one of the most important factors in the development of symptoms and complications associated with MPNs.High white blood cell counts in chronic myelocytic leukemia also known as leukocytosis may lead to central nervous system findings. Tumors developing outside the bone marrow named as extramedullary myeloid tumors (EMMT could be detected at the initial diagnosis or during the prognosis of the disease, which may cause neurological symptoms due to pressure of leukemic cell mass on various tissues along with spinal cord. Central nervous system involvement and thrombocytopenic hemorrhage may lead to diverse neurological symptoms and findings.Transient ischemic attack and thrombotic stroke are the most common symptoms in polycythemia vera. Besides thrombosis and hemorrage, transformation to acute leukemia can cause neurological symptoms and findings. Transient ischemic attack, thrombotic stroke and specifically hemorrage can give rise to neurological symptoms similar to MPN in essential thrombocytosis.Extramedullary hematopoiesis refers to hematopoietic centers arise in organ/tissues other than bone marrow in myelofibrosis. Extramedullar hematopoietic centers may cause intracranial involvement, spinal cord compression, seizures and hydrocephalia. Though rare, extramedullary hematopoiesis can be detected in cranial/spinal meninges, paraspinal tissue and intracerebral regions. Extramedullary hematopoiesis has been reported in peripheral neurons, choroid plexus, pituitary, orbits, orbital and lacrimal fossa and in sphenoidal sinuses. [Cukurova Med J 2013; 38(2.000: 157-169

  3. Radiological findings of pulmonary aspergillosis

    International Nuclear Information System (INIS)

    The pulmonary aspergillosis is a group of three separate disease, comprising invasive aspergillosis, aspergilloma, and allergic bronchopulmonary aspergillosis, or a disease process in which one of three entities overlap with another process such as mucoid impaction, pulmonary infiltration with eosinophilia, bronchocentric granulomatosis, microgranulomatous hypersensitivity, or asthma. The radiological findings of 24 cases of pulmonary aspergillosis diagnosed and treated at Seoul National University Hospital during the past 7 years were analyzed retrospectively. The results were as follows: 1. Final diagnosis of 24 cases of pulmonary aspergillosis was aspergilloma in 16 cases, invasive aspergillosis in 2 cases, variant form of allergic bronchopulmonary aspergillosis in 3 cases, and endobronchial aspergillosis in 3 cases. 2. The underlying causes of the aspergilloma were healed tuberculous cavity in 6 cases, bronchiectasis in 8 cases, and no underlying cause were found in 2 cases. All the 16 cases of aspergilloma were correctly diagnosed without difficultly by demonstrating the intracavitary mass or air meniscus. 3. Radiological findings of the invasive aspergillosis in kidney transplant patients were multiple round nodules with early cavitation and formation of aspergilloma which shows slowly progressive cavitation over 13 months in one case, and diffusely scattered miliary nodules with occasional cavitation in the other case. 4. Classic allergic bronchopulmonary asper4. Classic allergic bronchopulmonary aspergillosis were not found in our series but variant form of ABPA was found in 3 young female patients. All the three patients shows some degree of central bronchiectasis and combined aspergilloma was found in 2 cases. 5. Three patients diagnosed as endobronchial aspergillosis-saprophytic infection of aspergillus in the bronchial tree-by bronchoscopic biopsy shows nonspecific radiological findings

  4. MRI findings in Hirayama disease

    Directory of Open Access Journals (Sweden)

    Raval Monali

    2010-01-01

    Full Text Available The objective of the study was to study the magnetic resonance imaging (MRI features of Hirayama disease on a 3 Tesla MRI scanner. Nine patients with clinically suspected Hirayama disease were evaluated with neutral position, flexion, contrast-enhanced MRI and fast imaging employing steady-state acquisition (FIESTA sequences. The spectrum of MRI features was evaluated and correlated with the clinical and electromyography findings. MRI findings of localized lower cervical cord atrophy (C5-C7, abnormal curvature, asymmetric cord flattening, loss of attachment of the dorsal dural sac and subjacent laminae in the neutral position, anterior displacement of the dorsal dura on flexion and a prominent epidural space were revealed in all patients on conventional MRI as well as with the dynamic 3D-FIESTA sequence. Intramedullary hyperintensity was seen in four patients on conventional MRI and on the 3D-FIESTA sequence. Flow voids were seen in four patients on conventional MRI sequences and in all patients with the 3D-FIESTA sequence. Contrast enhancement of the epidural component was noted in all the five patients with thoracic extensions. The time taken for conventional and contrast-enhanced MRI was about 30-40 min, while that for the 3D-FIESTA sequence was 6 min. Neutral and flexion position MRI and the 3D-FIESTA sequence compliment each other in displaying the spectrum of findings in Hirayama disease. A flexion study should form an essential part of the screening protocol in patients with suspected Hirayama disease. Newer sequences such as the 3D-FIESTA may help in reducing imaging time and obviating the need for contrast.

  5. Large-scale structure of the Taurus molecular complex. II. Analysis of velocity fluctuations and turbulence. III. Methods for turbulence

    International Nuclear Information System (INIS)

    The velocity autocorrelation function (ACF) of observed spectral line centroid fluctuations is noted to effectively reproduce the actual ACF of turbulent gas motions within an interstellar cloud, thereby furnishing a framework for the study of the large scale velocity structure of the Taurus dark cloud complex traced by the present C-13O J = 1-0 observations of this region. The results obtained are discussed in the context of recent suggestions that widely observed correlations between molecular cloud widths and cloud sizes indicate the presence of a continuum of turbulent motions within the dense interstellar medium. Attention is then given to a method for the quantitative study of these turbulent motions, involving the mapping of a source in an optically thin spectral line and studying the spatial correlation properties of the resulting velocity centroid map. 61 references

  6. MR findings in peliosis hepatis

    International Nuclear Information System (INIS)

    We report the MR findings of peliosis hepatis in a patient with Fanconi anemia who had been treated with anabolic androgenic steroids for 3 years. The MR examination of the upper abdomen was performed on a 0.5 T system. The signal intensity of the right lobe of the liver was diffusely increased in all sequences. Within the enlarged liver, multiple foci of brighter signal were seen involving both right and left lobes. The lesions showed contrast enhancement. A cystic cavity with an enhancing rim was seen representing a haematoma cavity. The spleen was spared the patient died of sepsis and the postmortem examination confirmed the diagnosis of peliosis hepatis. (orig.)

  7. Sternal muscle: a mammographic finding

    International Nuclear Information System (INIS)

    The sternal muscle is an uncommon anatomic variant of the chest wall usually located only in one side along the sternal border. The superficial location of the muscle sometimes presents a mammographic finding as an asymmetric density in the middle and deep area on the cranio caudal projection, resembling a malignant lesion. Conclusive diagnosis is provided by CT and MR showing the sternal muscle. It is important to know this variant in order to reduce the number of patients undergoing new mammographic studies, any other imaging procedure or biopsy. (Author) 4 refs

  8. Duodenal diverticulitis. computed tomography findings

    International Nuclear Information System (INIS)

    Duodenal diverticular occur very frequently among the general public. However, duodenal diverticulitis is a very uncommon clinical entity, the diagnosis of which requires radiological studies since the clinical signs cam mimic a great number of disease processes with different treatments. We present a case of duodenal diverticulitis in which the diagnosis according to ultrasound and computed tomography (CT) studies was confirmed intraoperatively. We also review the few cases of this entity reported in the literature. The CT findings are highly suggestive of duodenal diverticulitis given their similarity to those associated with diverticulitis at other sites. (Author) 5 refs,

  9. MR findings in peliosis hepatis

    Energy Technology Data Exchange (ETDEWEB)

    Saatci, I. [Dept. of Diagnostic Radiology, Hacettepe Univ. Hospital, Ankara (Turkey); Coskun, M. [Dept. of Diagnostic Radiology, Hacettepe Univ. Hospital, Ankara (Turkey); Boyvat, F. [Dept. of Diagnostic Radiology, Hacettepe Univ. Hospital, Ankara (Turkey); Cila, A. [Dept. of Diagnostic Radiology, Hacettepe Univ. Hospital, Ankara (Turkey); Guergey, A. [Dept. of Pediatric Hematology, Hacettepe Univ. Hospital, Ankara (Turkey)

    1995-02-01

    We report the MR findings of peliosis hepatis in a patient with Fanconi anemia who had been treated with anabolic androgenic steroids for 3 years. The MR examination of the upper abdomen was performed on a 0.5 T system. The signal intensity of the right lobe of the liver was diffusely increased in all sequences. Within the enlarged liver, multiple foci of brighter signal were seen involving both right and left lobes. The lesions showed contrast enhancement. A cystic cavity with an enhancing rim was seen representing a haematoma cavity. The spleen was spared the patient died of sepsis and the postmortem examination confirmed the diagnosis of peliosis hepatis. (orig.)

  10. Breast spongioma: Aunt Minnie findings

    International Nuclear Information System (INIS)

    Gossypiboma is a term used to refer to pseudo-tumors composed of a non-absorbable cotton matrix. Retained sponge in the breast is extremely rare in the literature. The radiologic identification of gossypiboma is difficult because of their variable appearance. But when typical radiologic appearances are present in a patient with previous breast surgery, pre-operative diagnosis of a retained surgical sponge may prevent fatal complications. We present 'Aunt Minnie' findings of gossypiboma in a patient with previous breast surgery including ultrasound (US), mammogram and computed tomography (CT)

  11. Breast spongioma: Aunt Minnie findings

    Energy Technology Data Exchange (ETDEWEB)

    Baysal, Tamer [Inonu University, School of Medicine, Department of Radiology, Turgut Ozal Medical Center, Malatya (Turkey)]. E-mail: tbaysal@inonu.edu.tr; Mutlu, Deniz [Inonu University, School of Medicine, Department of Radiology, Turgut Ozal Medical Center, Malatya (Turkey); Erdogan, Ozgul [Inonu University, School of Medicine, Department of Radiology, Turgut Ozal Medical Center, Malatya (Turkey)

    2005-11-01

    Gossypiboma is a term used to refer to pseudo-tumors composed of a non-absorbable cotton matrix. Retained sponge in the breast is extremely rare in the literature. The radiologic identification of gossypiboma is difficult because of their variable appearance. But when typical radiologic appearances are present in a patient with previous breast surgery, pre-operative diagnosis of a retained surgical sponge may prevent fatal complications. We present 'Aunt Minnie' findings of gossypiboma in a patient with previous breast surgery including ultrasound (US), mammogram and computed tomography (CT)

  12. Cholangiographic findings in ulcerative colitis

    International Nuclear Information System (INIS)

    Endoscopic retrograde cholangiography (ERC) was performed in 28 patients with hepatobiliary disease associated with ulcerative colitis. The films were reviewed and correlated with diagnoses at liver biopsy. Thirteen patients with extrahepatic as well as intrahepatic bile duct abnormalities had characteristic cholangiographic findings compatible with sclerosing cholangitis, together with cholangiocarcinoma in one patient. Six patients had intrahepatic bile duct involvement only, and the cholangiographic abnormalities differed from those of sclerosing cholangitis. In 5 of these patients cirrhosis of the liver was found at biopsy or clinically. The result indicates that in patients with hepatobiliary disease suggested in association with ulcerative colitis, ERC gives valuable information. (Auth.)

  13. Acute Inflammatory Demyelinating Polyneuropathy in Children; Clinical and Electrophysiologic Findings

    OpenAIRE

    Farhad Mahvelati Shamsabadi; Parvaneh Karimzadeh; Seyed-Hasan Tonekaboni; Javad Ghorobi

    2009-01-01

    Objective:The aim of this study was to evaluate the electrophysiologic findings of Guillain Barre Syndrome (GBS) in children and their relation with clinical progress of the disease. Methods:Twenty-three children with GBS were evaluated between 2005 and 2007. Electrophysiologic evaluations were performed at admission and one month later. Findings: Five patients needed respirator, 15 were bedridden, 1 developed recurrence 6 months later, and 2 experienced chronic GBS. The most common findings ...

  14. Groove Pancreatitis: Spiral CT Findings

    International Nuclear Information System (INIS)

    To describe the spiral CT findings of groove pancreatitis, a little known entity, and to review its differential diagnosis. We present 8 cases of groove pancreatitis. or pancreatitis affecting the groove between pancreatic head, duodenum and common bile duct, all studied with spiral CT. For two cases, in which were performed cephalic duodenopancreatectomies, anatomopathological correlations were available. In the other 6 cases, radiological follow-ups of anywhere between 5 and 36 months were utilized. In all eight cases, spiral CT showed expansion and increasing density of lipids within the groove with poor contrast enhancement indicative of the fibrous nature of this pathology, and associated with cystic areas in its interior and/or the duodenal wall. the pancreatic head was unaffected in pure forms of groove pancreatitis, and hypodense areas were observed in zones of cephalic segmental enhancement. Knowledge of this little known form of chronic pancreatitis, and the radiological findings that permit its diagnosis are important for the radiologist since its differential diagnosis includes neoplasia of the peri-ampullary region. (Author) 6 refs

  15. Internal auditory canal (IAC) stenosis: imaging Findings

    International Nuclear Information System (INIS)

    Objectives: To describe the computed tomography (CT) and magnetic resonance (MR) findings in a patient with a diagnosis of internal auditory canal (IAC) stenosis. To describe the embryological development of the IAC structures and the natural history of IAC stenosis. Methods: A 4 year old girl presents with sensorineural hearing loss and bilateral recurrent otitis media. The temporal bone CT shows diminished left IAC diameter (less than 2 mm), right IAC absence and normal inner ear structures. These findings are pathognomonic for left IAC stenosis. The MR findings include left IAC stenosis and IAC neural structures absence secondary to aplasia of the vestibulocochlear nerve on each IAC . Results: Hypoplasia/aplasia of the vestibulocochlear nerve in association with IAC stenosis is an important consideration in the differential diagnosis of sensorineural hearing loss, as it is a relative contraindication for cochlear implant placement. Conclusions: IAC stenosis and vestibulocochlear nerve hypoplasia/aplasia must be excluded as an etiology of sensorineural hearing loss. The diagnosis can be made by CT and MR.

  16. Internal auditory canal (IAC) stenosis: Imaging findings

    International Nuclear Information System (INIS)

    Objectives: To describe the computed tomography (CT) and magnetic resonance (MR) findings in a patient with a diagnosis of internal auditory canal (IAC) stenosis. To describe the embryological development of the IAC structures and the natural history of IAC stenosis. Methods: A 4 year old girl presents with sensorineural hearing loss and bilateral recurrent otitis media. The temporal bone CT shows diminished left IAC diameter (less than 2 mm), right IAC absence and normal inner ear structures. These findings are pathognomonic for left IAC stenosis. The MR findings include left IAC stenosis and IAC neural structures absence secondary to aplasia of the vestibulocochlear nerve on each IAC. Results: Hypoplasia/aplasia of the vestibulocochlear nerve in association with IAC stenosis is an important consideration in the differential diagnosis of sensorineural hearing loss, as it is a relative contraindication for cochlear implant placement. Conclusions: IAC stenosis and vestibulocochlear nerve hypoplasia/aplasia must be excluded as an etiology of sensorineural hearing loss. The diagnosis can be made by CT and MR.

  17. Rhabdoid tumour of the kidney: imaging findings

    International Nuclear Information System (INIS)

    Background. Rhabdoid tumour of the kidney (RTK) is a rare tumour, but it is the most aggressive malignant neoplasm of the kidney in children. Objective. To analyse the radiological findings of RTK in children. Materials and methods. The clinical and radiological findings in seven children (age range 6 months to 4.7 years; median 18 months) with pathologically proven RTK were retrospectively reviewed. We analysed tumour size, tumour location, tumour margin, subcapsular haematoma, tumour necrosis, haemorrhage, calcification and lymphadenopathy. Results. Tumour size varied from 5 to 12 cm. Four tumours were located mainly in the central portion of the kidney, while three tumours were mainly sited peripherally. The margins of the tumour were ill-defined in four (57 %) of seven cases, a lobulated tumour surface was depicted in all seven (100 %), subcapsular haematoma was present in four (57 %), tumour necrosis or haemorrhage in seven (100 %), calcifications in three (43 %) and retroperitoneal lymphadenopathy in four (57 %). Conclusions. Imaging findings of RTK are subcapsular haematoma, a lobulated surface of the tumour, calcification and tumour necrosis or haemorrhage. (orig.)

  18. Brain computed tomography findings of schizophrenia, (2)

    International Nuclear Information System (INIS)

    The relationship between brain CT findings and the total dose of antipsychotic drugs was examined in 47 cases with schizophrenia ranging from 20 to 42 years in age (31 males and 16 females). The methods of Gyldensted et al. and Okamoto et al. were modified for CT measurements. The total dose during the entire course was converted into the dose of chlorpromazine (CPZ) for each case. For comparisons with CT findings, the total dose was classified into three types each for both sexes: ''less than'' 100 g, ''less than'' 500 g and ''more than'' 500 g for the males and ''more than'' 500 g, ''less than'' 1,000 g and ''more than'' 1,000 g for the females. For similar comparisons, the same subjects were matched for the age and sex distinction, and were divided into the ''less than'' and ''more than'' groups for 500 g and 800 g, respectively. In both the matched and non-matched cases, each measurement value of the ventricular system on CT tended to be higher in the ''more than'' groups than in the ''less than'' groups. The relationship between CT findings and the total dose was nogligible. (Chiba, N.)

  19. MRI Findings in Patients with TMJ Click

    Directory of Open Access Journals (Sweden)

    Mahrokh Imanimoghaddam

    2013-12-01

    Full Text Available Introduction: It has been shown that joint click, an initial and common finding in internal derangement (ID, respond to neither conservative treatment nor surgical intervention. This raises the question as to whether it must be treated in the absence of other pertinent signs and symptoms, so the aim of this study was to investigate and compare the MRI findings of TMJ in both normal subjects and patients with click, in order to determine the importance of click in predicting TMJ pathological changes. Methods: A total of 26 patients with clinical symptoms of disk displacement with reduction (DDwR according to RDC/TMD were compared to 14 normal subjects in terms of their MRI findings, including disk displacement, effusion, condylar osteoarthritic changes and disk deformities. Results: Out of 80 joints in total (52 affected joints in 26 patients and 28 joints in control group, 48 were shown with normal disk position in MRI whereas 28 (35% and 4 (5% were categorised as DDwR and (disk displacement without reduction DDwoR, respectively. Statistically significant correlations were established between the following pairs of variables in order: Click and disk displacement, effusion and disk displacement, disk displacement and effusion with disk deformity. Conclusion: The correlation between the presence of click and disk displacement, disk deformity and effusion emphasizes the importance of MRI for an accurate diagnosis and development of an appropriate treatment plan in these cases and shows that clinical examination is not sufficient for these purposes.

  20. High resolution CT findings of acoustic neurinoma

    International Nuclear Information System (INIS)

    High-resolution CT can be taken by the target imaging of the software reconstruction technique from live data stored in a magnetic disc. At first, the conditions of the target imaging of the temporal bone were fundamentally studied and were determined by means of a CT/T, X-2 (8800). We then applied this method in 6 cases of acoustic tumor in order to measure the size of the tumor in the posterior fossa, the shape of the internal auditory canal, the anterior-posterior diameter (width), the lengths of the anterior wall and the posterior wall on the axial scan, and the upper-lower diameter (height) on the coronal scan. The symmetrical differences in these parameters were also determined. On the basis of these findings, it was considered that the most important findings obtained by high-resolution CT regarding the internal auditory canal are the shape of the internal auditory canal and the angles of the internal auditory canal. The expansion of the tumor in the internal auditory canal was estimated on the basis of these findings. (J.P.N.)