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Sample records for centroid finding method

  1. Centroid finding method for position-sensitive detectors

    Energy Technology Data Exchange (ETDEWEB)

    Radeka, V.; Boie, R.A.

    1979-10-01

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

  2. 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.)

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

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    Moysés Nascimento

    2015-02-01

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

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

    Science.gov (United States)

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

    2015-11-01

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

  5. A physics-motivated Centroidal Voronoi Particle domain decomposition method

    Science.gov (United States)

    Fu, Lin; Hu, Xiangyu Y.; Adams, Nikolaus A.

    2017-04-01

    In this paper, we propose a novel domain decomposition method for large-scale simulations in continuum mechanics by merging the concepts of Centroidal Voronoi Tessellation (CVT) and Voronoi Particle dynamics (VP). The CVT is introduced to achieve a high-level compactness of the partitioning subdomains by the Lloyd algorithm which monotonically decreases the CVT energy. The number of computational elements between neighboring partitioning subdomains, which scales the communication effort for parallel simulations, is optimized implicitly as the generated partitioning subdomains are convex and simply connected with small aspect-ratios. Moreover, Voronoi Particle dynamics employing physical analogy with a tailored equation of state is developed, which relaxes the particle system towards the target partition with good load balance. Since the equilibrium is computed by an iterative approach, the partitioning subdomains exhibit locality and the incremental property. Numerical experiments reveal that the proposed Centroidal Voronoi Particle (CVP) based algorithm produces high-quality partitioning with high efficiency, independently of computational-element types. Thus it can be used for a wide range of applications in computational science and engineering.

  6. A Method for Analog Implementation of Centroid Tracking Algorithm in a Video Signal

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    Payman Moallem

    2007-06-01

    Full Text Available The main goal of a video tracking algorithm is finding the location of a predefined target in successive video frames. Centroid pointing is one of the most efficient methods in the target tracking. This method can be simply implemented by a digital video processing system that includes a video memory and a powerful digital processor. Usually, the cost and the complexity of the digital video processor is high and in some applications, using analog video processor that includes only electronic devices like OPAMP, diodes, transistors, resistors and capacitors has lower cost, more efficient and more reliable. Implementing of the centroid in an analog video processor is not as simple as digital one, therefore in this paper, we introduce a novel formulation of the centroid that can be implemented in an analog video processor. We simulate the proposed method by MatLab simulink and compare the results with the area-based tracking that is usually used in analog video processors. The simulation results show that the proposed method is more reliable and accurate.

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

    DEFF Research Database (Denmark)

    Eskildsen, Jacob Kjær; Kristensen, Kai; Nielsen, Rikke

    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....

  8. Do fast stellar centroiding methods saturate the Cram\\'{e}r-Rao lower bound?

    CERN Document Server

    Vakili, Mohammadjavad

    2016-01-01

    One of the most demanding tasks in astronomical image processing---in terms of precision---is the centroiding of stars. Upcoming large surveys are going to take images of billions of point sources, including many faint stars, with short exposure times. Real-time estimation of the centroids of stars is crucial for real-time PSF estimation, and maximal precision is required for measurements of proper motion. The fundamental Cram\\'{e}r-Rao lower bound sets a limit on the root-mean-squared-error achievable by optimal estimators. In this work, we aim to compare the performance of various centroiding methods, in terms of saturating the bound, when they are applied to relatively low signal-to-noise ratio unsaturated stars assuming zero-mean constant Gaussian noise. In order to make this comparison, we present the ratio of the root-mean-squared-errors of these estimators to their corresponding Cram\\'{e}r-Rao bound as a function of the signal-to-noise ratio and the full-width at half-maximum of faint stars. We discuss...

  9. Real-time auto-focusing technique using centroid method for space camera

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    A real-time auto-focusing system with auto-collimation method is introduced, which is used in autodetecting the focus of the space camera with long focus. Auto-focusing is the key technique to ensure high quality in space imaging. It can measure and compensate the defocus caused by the change of temperature and air pressure etc. in space. To solve the problem of auto-focusing with auto-collimation method of the camera whose axis is perpendicular to the ground, it is designed that two small caliber pentagonal prisms are placed in the area of aperture suitable to the camera's relative aperture based on the theory of auto-focusing with auto-collimation, which can replace the big caliber plane reflector used in other cameras. Using the characteristic of pentagonal prism refracting light vertically, the target slit is imaged in CCD through the two-separated lens. It transforms the detecting of the axial defocusing quantity to the landscape orientation measurement of the faculae's position in the direction of CCD pixels. The defocusing quantity is obtained by measuring the opposite position of the two faculae on the CCD. The Centroid method is adopted to measure the position of the auto-collimation faculae. The arithmetic error is analyzed especially, and the causation is given. Experiments show that this real-time auto-focusing system using centroid method is reliable and the focusing precision can reach ±0.01 mm.

  10. 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 α-plane representation, and proposed a type-reduction method for a type-2 fuzzy set. By exploring some useful properties of the α-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.

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

    Energy Technology Data Exchange (ETDEWEB)

    Vargas, Javier; Gonzalez-Fernandez, Luis; Quiroga, Juan Antonio; Belenguer, Tomas

    2010-05-01

    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 range imaging capabilities of the SH sensor through the use of a set of different CCD integration times. The resultant extended range spot map is normalized to accurately obtain the spot centroids. The proposed method has been applied to measure the optical quality of the main optical system (MOS) of the mid-infrared instrument telescope smulator. The wavefront at the exit of this optical system is affected by speckle noise when it is illuminated by a laser source and by air turbulence because it has a long back focal length (3017 mm). Using the proposed technique, the MOS wavefront error was measured and satisfactory results were obtained.

  12. Ranking Fuzzy Numbers with a Distance Method using Circumcenter of Centroids and an Index of Modality

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    P. Phani Bushan Rao

    2011-01-01

    Full Text Available Ranking fuzzy numbers are an important aspect of decision making in a fuzzy environment. Since their inception in 1965, many authors have proposed different methods for ranking fuzzy numbers. However, there is no method which gives a satisfactory result to all situations. Most of the methods proposed so far are nondiscriminating and counterintuitive. This paper proposes a new method for ranking fuzzy numbers based on the Circumcenter of Centroids and uses an index of optimism to reflect the decision maker's optimistic attitude and also an index of modality that represents the neutrality of the decision maker. This method ranks various types of fuzzy numbers which include normal, generalized trapezoidal, and triangular fuzzy numbers along with crisp numbers with the particularity that crisp numbers are to be considered particular cases of fuzzy numbers.

  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

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

    Energy Technology Data Exchange (ETDEWEB)

    Ringler, Todd; Ju, Lili; Gunzburger, Max

    2008-11-14

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

  16. A multi-resolution method for climate system modeling: application of spherical centroidal Voronoi tessellations

    Energy Technology Data Exchange (ETDEWEB)

    Ringler, Todd [Los Alamos National Laboratory; Ju, Lili [University of South Carolina; Gunzburger, Max [Florida State University

    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 multiresolution schemes that are able, at least regionally, to faithfully simulate these fine-scale processes. Spherical centroidal Voronoi tessellations (SCVTs) offer one potential path toward the development of a robust, multiresolution climate system model components. SCVTs allow for the generation of high quality Voronoi diagrams and Delaunay triangulations through the use of an intuitive, user-defined density function. In each of the examples provided, this method results in high-quality meshes where the quality measures are guaranteed to improve as the number of nodes is increased. Real-world examples are developed for the Greenland ice sheet and the North Atlantic ocean. Idealized examples are developed for ocean–ice shelf interaction and for regional atmospheric modeling. In addition to defining, developing, and exhibiting SCVTs, we pair this mesh generation technique with a previously developed finite-volume method. Our numerical example is based on the nonlinear, shallow water equations spanning the entire surface of the sphere. This example is used to elucidate both the potential benefits of this multiresolution method and the challenges ahead.

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

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    Régis J.-M.

    2015-01-01

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

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

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    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.

  19. A novel, view-independent method for strain mapping in myocardial elastography: eliminating angle and centroid dependence

    Energy Technology Data Exchange (ETDEWEB)

    Zervantonakis, I K; Fung-Kee-Fung, S D; Lee, W-N; Konofagou, E E [Department of Biomedical Engineering, Columbia University, New York, NY (United States)

    2007-07-21

    Robust indices of regional and global cardiac function are a key factor in detection and treatment of heart disease as well as understanding of the fundamental mechanisms of a healthy heart. Myocardial elastography provides a noninvasive method for imaging and measuring displacement and strain of the myocardium for the early detection of cardiovascular disease. However, two-dimensional in-plane axial and lateral strains measured depend on the sonographic view used. This becomes especially critical in a clinical setting and may induce large variations in the measured strains, potentially leading to false diagnoses. A novel method in myocardial elastography is proposed for eliminating this view dependence by deriving the polar, principal and classified principal strains. The performance of the proposed methodology is assessed by employing 3D finite-element left-ventricular models of a control and an ischemic canine heart. Although polar strains are angle-independent, they are sensitive to the selected reference coordinate system, which requires the definition of a centroid of the left ventricle (LV). In contrast, principal strains derived through eigenvalue decomposition exhibit the inherent characteristic of coordinate system independence, offering view (i.e., angle and centroid)-independent strain measurements. Classified principal strains are obtained by assigning the principal components in the physical ventricular coordinate system. An extensive strain analysis illustrates the improvement in interpretation and visualization of the full-field myocardial deformation by using the classified principal strains, clearly depicting the ischemic and non-ischemic regions. Strain maps, independent of sonographic views and imaging planes, that can be used to accurately detect regional contractile dysfunction are demonstrated.

  20. A novel, view-independent method for strain mapping in myocardial elastography: eliminating angle and centroid dependence

    Science.gov (United States)

    Zervantonakis, I. K.; Fung-Kee-Fung, S. D.; Lee, W.-N.; Konofagou, E. E.

    2007-07-01

    Robust indices of regional and global cardiac function are a key factor in detection and treatment of heart disease as well as understanding of the fundamental mechanisms of a healthy heart. Myocardial elastography provides a noninvasive method for imaging and measuring displacement and strain of the myocardium for the early detection of cardiovascular disease. However, two-dimensional in-plane axial and lateral strains measured depend on the sonographic view used. This becomes especially critical in a clinical setting and may induce large variations in the measured strains, potentially leading to false diagnoses. A novel method in myocardial elastography is proposed for eliminating this view dependence by deriving the polar, principal and classified principal strains. The performance of the proposed methodology is assessed by employing 3D finite-element left-ventricular models of a control and an ischemic canine heart. Although polar strains are angle-independent, they are sensitive to the selected reference coordinate system, which requires the definition of a centroid of the left ventricle (LV). In contrast, principal strains derived through eigenvalue decomposition exhibit the inherent characteristic of coordinate system independence, offering view (i.e., angle and centroid)-independent strain measurements. Classified principal strains are obtained by assigning the principal components in the physical ventricular coordinate system. An extensive strain analysis illustrates the improvement in interpretation and visualization of the full-field myocardial deformation by using the classified principal strains, clearly depicting the ischemic and non-ischemic regions. Strain maps, independent of sonographic views and imaging planes, that can be used to accurately detect regional contractile dysfunction are demonstrated.

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

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    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

  2. A method for the assessment of oxide charge density and centroid in metal-oxide-semiconductor structures after uniform gate stress

    Science.gov (United States)

    Kies, R.; Egilsson, T.; Ghibaudo, G.; Pananakakis, G.

    1996-06-01

    A method for the extraction of the oxide charge density and distribution centroid based on the exploitation of the Fowler plot derivative characteristics is proposed. To this end, the modification of the tunnel transparency due to the presence of charge within the tunneling region is accounted for. Simple analytical formulas which enable the oxide charge density and centroid to be extracted from the maximum Fowler derivative and its electric field position are derived. The comparison with the DiMaria method confirms the overall consistency of the new approach. The impact of negative charge within the oxide on the apparent Fowler barrier height, which can be deduced from the slope of the Fowler plots after uniform gate stress is also analyzed. Finally, it is pointed out that this method permits the oxide trapping properties to be studied even though only one bias polarization can be utilized for the test structure.

  3. A Reference Point Construction Method Using Mobile Terminals and the Indoor Localization Evaluation in the Centroid Method

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    Takahiro Yamaguchi

    2015-05-01

    Full Text Available As smartphones become widespread, a variety of smartphone applications are being developed. This paper proposes a method for indoor localization (i.e., positioning that uses only smartphones, which are general-purpose mobile terminals, as reference point devices. This method has the following features: (a the localization system is built with smartphones whose movements are confined to respective limited areas. No fixed reference point devices are used; (b the method does not depend on the wireless performance of smartphones and does not require information about the propagation characteristics of the radio waves sent from reference point devices, and (c the method determines the location at the application layer, at which location information can be easily incorporated into high-level services. We have evaluated the level of localization accuracy of the proposed method by building a software emulator that modeled an underground shopping mall. We have confirmed that the determined location is within a small area in which the user can find target objects visually.

  4. 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

  5. A comparative study of the centroid and ring-polymer molecular dynamics methods for approximating quantum time correlation functions from path integrals

    Science.gov (United States)

    Pérez, Alejandro; Tuckerman, Mark E.; Müser, Martin H.

    2009-05-01

    The problems of ergodicity and internal consistency in the centroid and ring-polymer molecular dynamics methods are addressed in the context of a comparative study of the two methods. Enhanced sampling in ring-polymer molecular dynamics (RPMD) is achieved by first performing an equilibrium path integral calculation and then launching RPMD trajectories from selected, stochastically independent equilibrium configurations. It is shown that this approach converges more rapidly than periodic resampling of velocities from a single long RPMD run. Dynamical quantities obtained from RPMD and centroid molecular dynamics (CMD) are compared to exact results for a variety of model systems. Fully converged results for correlations functions are presented for several one dimensional systems and para-hydrogen near its triple point using an improved sampling technique. Our results indicate that CMD shows very similar performance to RPMD. The quality of each method is further assessed via a new χ2 descriptor constructed by transforming approximate real-time correlation functions from CMD and RPMD trajectories to imaginary time and comparing these to numerically exact imaginary time correlation functions. For para-hydrogen near its triple point, it is found that adiabatic CMD and RPMD both have similar χ2 error.

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

    Directory of Open Access Journals (Sweden)

    R. Thangarajan

    2009-06-01

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

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

    Directory of Open Access Journals (Sweden)

    Yan Guo

    2011-01-01

    Full Text Available 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 depends on the centroid position and the pitch angle of stairs, and the numerical formula is developed about the relationship between the maximal stability-keeping angle and the centroid position and pitch angle of stairs. The experiment demonstrates the trustworthy and correction of the method in the paper.

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

    OpenAIRE

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

    2009-01-01

    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 ...

  9. ESTIMATION OF DOPPLER CENTROID FREQUENCY IN SPACEBORNE SCANSAR

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    Doppler centroid frequency is an essential parameter in the imaging processing of the Scanning mode Synthetic Aperture Radar(ScanSAR).Inaccurate Doppler centroid frequency will result in ghost images in imaging result.In this letter,the principle and algorithms of Doppler centroid frequency estimation are introduced.Then the echo data of ScanSAR system is analyzed.Based on the algorithms of energy balancing and correlation Doppler estimator in the estimation of Doppler centroid fequency in strip mode SAR,an improved method for Doppler centroid frequency estimation in ScanSAR is proposed.The method has improved the accuracy of Doppler centroid fequency estimation in ScanSAR by zero padding between burst data.Finally,the proposed method is validated with the processing of ENVironment SATellite Advanced Synthetic Aperture Radar(ENVISAT ASAR)wide swath raw data.

  10. Nearest shrunken centroids via alternative genewise shrinkages

    Science.gov (United States)

    Choi, Byeong Yeob; Bair, Eric; Lee, Jae Won

    2017-01-01

    Nearest shrunken centroids (NSC) is a popular classification method for microarray data. NSC calculates centroids for each class and “shrinks” the centroids toward 0 using soft thresholding. Future observations are then assigned to the class with the minimum distance between the observation and the (shrunken) centroid. Under certain conditions the soft shrinkage used by NSC is equivalent to a LASSO penalty. However, this penalty can produce biased estimates when the true coefficients are large. In addition, NSC ignores the fact that multiple measures of the same gene are likely to be related to one another. We consider several alternative genewise shrinkage methods to address the aforementioned shortcomings of NSC. Three alternative penalties were considered: the smoothly clipped absolute deviation (SCAD), the adaptive LASSO (ADA), and the minimax concave penalty (MCP). We also showed that NSC can be performed in a genewise manner. Classification methods were derived for each alternative shrinkage method or alternative genewise penalty, and the performance of each new classification method was compared with that of conventional NSC on several simulated and real microarray data sets. Moreover, we applied the geometric mean approach for the alternative penalty functions. In general the alternative (genewise) penalties required fewer genes than NSC. The geometric mean of the class-specific prediction accuracies was improved, as well as the overall predictive accuracy in some cases. These results indicate that these alternative penalties should be considered when using NSC. PMID:28199352

  11. 相似度质心多层过滤策略的动态文摘方法%The similarity centroid multilayer filtering dynamic summarization method

    Institute of Scientific and Technical Information of China (English)

    于洋; 范文义; 刘美玲; 王慧强

    2014-01-01

    为了研究网络快速有效获取信息的方法,网络动态演化内容的识别和分析成为人们迫切需要解决的关键问题。动态多文档文摘建立在时间信息基础上,从网络数据的动态性能入手,对同一主题不同时段的文摘集合进行分析,在识别信息内容差异性的基础上,对信息的动态演化性进行建模。在提出相似度累加模型基础上,进一步提出了基于质心整体选优的动态文摘模型。分析当前文档集合与历史集合强关联性,以选择出的不同文摘句为首句生成候选文摘集合,然后根据质心多层过滤优选方法从中选出最优文摘结果。这种模型方法消除了因首句选择不当而对文摘性能造成的影响,在国际标准评测Taxt Anynasis Conference 2008的Update task任务语料上进行了测试,并且获得了较好的实验结果。%To research the method for quickly obtaining effective information on the internet, identifying and analy⁃zing dynamic evolution of the network has become a key issue that needs to be resolved urgently. Dynamic multi⁃document summarization is based on the time information starts from dynamic performance analysis of network data, the analyzes the abstracts collect about the same topic in different periods of time, and the models of dynamic evolu⁃tion of information on the basis of identifying differences of information contents. This paper first introduced the text similarity cumulative model and then the dynamic summarization model based on centroid integer selection. The high relevance between the current collection of documents and the historical collection was analyzed and different sentences summaries were selected and used as the first sentences of candidate set of abstracts newly generated. Next, the best abstracts were selected from the results based on the centroid multilayer filtering optimization meth⁃od. These models eliminate the impact on the abstract

  12. Evaluation for Success Probability of Chaff Centroid Jamming

    Institute of Scientific and Technical Information of China (English)

    GAO Dong-hua; SHI Xiu-hua

    2008-01-01

    As the chaff centroid jamming can introduce the guiding error of the anti-warship missile's seeker and decrease its hitting probability, a new quantitative analysis method and a mathematic model are proposed in this paper to evaluate the success jamming probability. By using this method, the optimal decision scheme of chaff centroid jamming in different threat situations can be found, and also the success probability of this scheme can be calculated quantitatively. Thus, the operation rules of the centroid jamming and the tactical approach for increasing the success probability can be determined.

  13. Variable centroid control scheme over hypersonic tactical missile

    Institute of Scientific and Technical Information of China (English)

    Yl; Yan(易彦); ZHOU; Fengqi(周凤岐)

    2003-01-01

    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.

  14. Photodissociation of Cl 2 in helium clusters: an application of hybrid method of quantum wavepacket dynamics and path integral centroid molecular dynamics

    Science.gov (United States)

    Takayanagi, Toshiyuki; Shiga, Motoyuki

    2003-04-01

    The photodissociation dynamics of Cl 2 embedded in helium clusters is studied by numerical simulation with an emphasis on the effect of quantum character of helium motions. The simulation is based on the hybrid model in which Cl-Cl internuclear dynamics is treated in a wavepacket technique, while the helium motions are described by a path integral centroid molecular dynamics approach. It is found that the cage effect largely decreases when the helium motion is treated quantum mechanically. The mechanism is affected not only by the zero-point vibration in the helium solvation structure, but also by the quantum dynamics of helium.

  15. Statistics of Centroids of Velocity

    CERN Document Server

    Esquivel, A

    2009-01-01

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

  16. 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.

  17. Systematic error analysis and compensation for high accuracy star centroid estimation of star tracker

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    Subpixel centroid estimation is the most important star image location method of star tracker. This paper presents a theoretical analysis of the systematic error of subpixel centroid estimation algorithm utilizing frequency domain analysis under the con-sideration of sampling frequency limitation and sampling window limitation. Explicit expression of systematic error of cen-troid estimation is obtained, and the dependence of systematic error on Gaussian width of star image, actual star centroid loca-tion and the number of sampling pixels is derived. A systematic error compensation algorithm for star centroid estimation is proposed based on the result of theoretical analysis. Simulation results show that after compensation, the residual systematic errors of 3-pixel-and 5-pixel-windows’ centroid estimation are less than 2×10-3 pixels and 2×10-4 pixels respectively.

  18. Research on Maneuverability of Moving Centroid Warhead

    Institute of Scientific and Technical Information of China (English)

    LIN Peng; ZHOU Feng-qi; ZHOU Jun

    2007-01-01

    The dynamic equations of the moving centroid warhead are derived, simplified and linearized, and a transfer function from moving mass displacement to normal overload of the warhead is obtained. Thus, the normal overload can be calculated when the mass moves to any different places. The research results provide a necessary theoretic reference for general design of control system of the moving centroid warhead.

  19. Estimating the Doppler centroid of SAR data

    DEFF Research Database (Denmark)

    Madsen, Søren Nørvang

    1989-01-01

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

  20. Point estimation of root finding methods

    CERN Document Server

    2008-01-01

    This book sets out to state computationally verifiable initial conditions for predicting the immediate appearance of the guaranteed and fast convergence of iterative root finding methods. Attention is paid to iterative methods for simultaneous determination of polynomial zeros in the spirit of Smale's point estimation theory, introduced in 1986. Some basic concepts and Smale's theory for Newton's method, together with its modifications and higher-order methods, are presented in the first two chapters. The remaining chapters contain the recent author's results on initial conditions guaranteing convergence of a wide class of iterative methods for solving algebraic equations. These conditions are of practical interest since they depend only on available data, the information of a function whose zeros are sought and initial approximations. The convergence approach presented can be applied in designing a package for the simultaneous approximation of polynomial zeros.

  1. Photon counting imaging and centroiding with an electron-bombarded CCD using single molecule localisation software

    Science.gov (United States)

    Hirvonen, Liisa M.; Barber, Matthew J.; Suhling, Klaus

    2016-06-01

    Photon event centroiding in photon counting imaging and single-molecule localisation in super-resolution fluorescence microscopy share many traits. Although photon event centroiding has traditionally been performed with simple single-iteration algorithms, we recently reported that iterative fitting algorithms originally developed for single-molecule localisation fluorescence microscopy work very well when applied to centroiding photon events imaged with an MCP-intensified CMOS camera. Here, we have applied these algorithms for centroiding of photon events from an electron-bombarded CCD (EBCCD). We find that centroiding algorithms based on iterative fitting of the photon events yield excellent results and allow fitting of overlapping photon events, a feature not reported before and an important aspect to facilitate an increased count rate and shorter acquisition times.

  2. COMPUTATIONALLY EFFICIENT ESPRIT METHOD FOR DIRECTION FINDING

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    In this paper, a low complexity ESPRIT algorithm based on power method and Orthogonal-triangular (QR) decomposition is presented for direction finding, which does not require a priori knowledge of source number and the predetermined threshold (separates the signal and noise eigen-values). Firstly, according to the estimation of noise subspace obtained by the power method, a novel source number detection method without eigen-decomposition is proposed based on QR decomposition. Furthermore, the eigenvectors of signal subspace can be determined according to Q matrix,and then the directions of signals could be computed by the ESPRIT algorithm. To determine the source number and subspace, the computation complexity of the proposed algorithm is approximated as (2log2 n+ 2.67)M3, where n is the power of covariance matrix and M is the number of array elements. Compared with the Single Vector Decomposition (SVD) based algorithm, it has a substantial computational saving with the approximation performance. The simulation results demonstrate its effectiveness and robustness.

  3. 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.

  4. 基于局部均值的 K-近质心近邻光谱分类%Spectra Classification Based on Local Mean-Based K-Nearest Centroid Neighbor Method

    Institute of Scientific and Technical Information of China (English)

    屠良平; 魏会明; 王志衡; 韦鹏; 罗阿理; 赵永恒

    2015-01-01

    天体光谱包含着许多重要的关于天体的物理和化学信息,如天体表面的有效温度、重力加速度以及化学丰度等,天体光谱的处理和分析对天文研究具有重要的科学意义。一些大型巡天计划的实施(如SDSS ,LAMOST等)使我们获得了海量的天文光谱数据,因此天文光谱数据的自动分类成为重要的科学研究课题,然而面对如此海量的光谱数据,一些传统的光谱自动分类方法已经不适用,迫切需要寻找高效率的光谱自动分类技术。研究了基于局部均值的 K‐近质心近邻(local mean‐based K‐nearest centroid neighbor , LMKNCN)算法在恒星(Star)、星系(Galaxy)和类星体(Quasar ,QSO)的光谱分类中的应用。LMKNCN算法的基本思想是根据近质心近邻原则,从每一类训练样本集中为待测样本点选取 k个近质心近邻点,然后根据每一类中所选取的 k个近质心近邻点的均值点到待测样本点 x的距离来判别 x 的所属类别。针对美国SDSS‐DR8的天体光谱数据,对比了 K‐近邻、K‐近质心近邻、LMKNCN三种算法在恒星、星系和类星体的光谱分类中所表现的性能,结果表明三种方法中,LMKNCN算法对这三种光谱的识别率高于其他两种算法或者与其相当,而且其平均分类正确率高于另外两种算法,特别是在类星体的识别率上表现的更好。表明了该算法对天文光谱大数据的快速处理和有效利用具有重要的意义。%In the present paper ,a local mean‐based K‐nearest centroid neighbor (LMKNCN) technique is used for the classifica‐tion of stars ,galaxies and quasars(QSOS) .The main idea of LMKNCN is that it depends on the principle of the nearest centroid neighborhood(NCN) ,and selects K centroid neighbors of each class as training samples and then classifies a query pattern into the class with the distance of the local centroid mean vector to the

  5. 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...

  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. Centroids computation and point spread function analysis for reverse Hartmann test

    Science.gov (United States)

    Zhao, Zhu; Hui, Mei; Liu, Ming; Dong, Liquan; Kong, Linqqin; Zhao, Yuejin

    2017-03-01

    This paper studies the point spread function (PSF) and centroids computation methods to improve the performance of reverse Hartmann test (RHT) in poor conditions, such as defocus, background noise, etc. In the RHT, we evaluate the PSF in terms of Lommel function and classify it as circle of confusion (CoC) instead of Airy disk. Approximation of a CoC spot with Gaussian or super-Gaussian profile to identify its centroid forms the basis of centroids algorithm. It is also effective for fringe pattern while the segmental fringe is served as a 'spot' with an infinite diameter in one direction. RHT experiments are conducted to test the fitting effects and centroiding performances of the methods with Gaussian and super-Gaussian approximations. The fitting results show that the super-Gaussian obtains more reasonable fitting effects. The super-Gauss orders are only slightly larger than 2 means that the CoC has a similar profile with Airy disk in certain conditions. The results of centroids computation demonstrate that when the signal to noise ratio (SNR) is falling, the centroid computed by super-Gaussian method has a less shift and the shift grows at a slower pace. It implies that the super-Gaussian has a better anti-noise capability in centroid computation.

  8. Star centroiding error compensation for intensified star sensors.

    Science.gov (United States)

    Jiang, Jie; Xiong, Kun; Yu, Wenbo; Yan, Jinyun; Zhang, Guangjun

    2016-12-26

    A star sensor provides high-precision attitude information by capturing a stellar image; however, the traditional star sensor has poor dynamic performance, which is attributed to its low sensitivity. Regarding the intensified star sensor, the image intensifier is utilized to improve the sensitivity, thereby further improving the dynamic performance of the star sensor. However, the introduction of image intensifier results in star centroiding accuracy decrease, further influencing the attitude measurement precision of the star sensor. A star centroiding error compensation method for intensified star sensors is proposed in this paper to reduce the influences. First, the imaging model of the intensified detector, which includes the deformation parameter of the optical fiber panel, is established based on the orthographic projection through the analysis of errors introduced by the image intensifier. Thereafter, the position errors at the target points based on the model are obtained by using the Levenberg-Marquardt (LM) optimization method. Last, the nearest trigonometric interpolation method is presented to compensate for the arbitrary centroiding error of the image plane. Laboratory calibration result and night sky experiment result show that the compensation method effectively eliminates the error introduced by the image intensifier, thus remarkably improving the precision of the intensified star sensors.

  9. Determination of Star Bodies from -Centroid Bodies

    Indian Academy of Sciences (India)

    Lujun Guo; Gangsong Leng

    2013-11-01

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

  10. Numerical Methods for Finding Stationary Gravitational Solutions

    CERN Document Server

    Dias, Oscar J C; Way, Benson

    2015-01-01

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

  11. 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.

  12. Rapid estimation of tsunami source centroid location using a dense offshore observation network

    Science.gov (United States)

    Yamamoto, N.; Hirata, K.; Aoi, S.; Suzuki, W.; Nakamura, H.; Kunugi, T.

    2016-05-01

    This paper proposes a rapid method of estimating tsunami source locations using real-time ocean-bottom hydrostatic pressure data from a dense offshore observation network. We defined two characteristic locations representing the real-time tsunami disturbance and the initial sea surface height distribution. First, we defined the tsunami centroid location (TCL), which is the centroid location of the maximum absolute amplitude of the real-time ocean-bottom hydrostatic pressure changes. Second, we defined the centroid location of the absolute values of the initial sea surface height displacements. To determine whether the TCL can approximate the centroid location of the tsunami source, we examined approximately 1000 near-field synthetic tsunami scenarios and a realistic tsunami scenario of the 2011 Tohoku earthquake in the Japan Trench. From these examinations, it was confirmed that in most scenarios, the TCLs obtained within a few minutes after the occurrence of an earthquake were close to the actual corresponding tsunami source locations.

  13. 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.)

  14. 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.

  15. 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...

  16. 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.

  17. Interstellar cloud structure: The statistics of centroid velocities

    CERN Document Server

    Ossenkopf, V; Lazarian, A; Stutzki, J

    2006-01-01

    The investigation of the statistical properties of maps of line centroids has been used for almost 50 years, but there is still no general agreement on their interpretation. We try to quantify which properties of underlying turbulent velocity fields can be derived from centroid velocity maps, and we test conditions under which the scaling behaviour of the centroid velocities matches the scaling of the three-dimensional velocity field. Using fractal cloud models we study systematically the relation between three-dimensional density and velocity fields and the statistical properties of the produced line centroid maps. We put special attention to cases with large density fluctuations resembling supersonic interstellar turbulence. Starting from the Delta-variance analysis we derive a new tool to compute the scaling behaviour of the three-dimensional velocity field from observed intensity and centroid velocity maps. We provide two criteria to decide whether the information from the centroid velocities directly ref...

  18. Study of velocity centroids based on the theory of fluctuations in position-position-velocity space

    CERN Document Server

    Kandel, D; Pogosyan, D

    2016-01-01

    We study possibility of obtaining velocity spectra by studying turbulence in an optically thick medium using velocity centroids (VCs).We find that the regime of universal, i.e. independent of underlying turbulence statistics, fluctuations discovered originally within the velocity channel analysis (VCA) carries over to the statistics of VCs. In other words, for large absorptions the VC lose their ability to reflect the spectra of turbulence. Combining our present study with the earlier studies of centroids in Esquivel & Lazarian, we conclude that centroids are applicable for studies subsonic/transsonic turbulence for the range of scales that is limited by the absorption effects. We also consider VCs based on absorption lines and define the range of their applicability. We address the problem of analytical description of spectra and anisotropies of fluctuations that are available through studies using VC. We obtain spectra and anisotropy of VC fluctuations arising from Alfv\\'en, slow and fast modes that con...

  19. Energy Centroids in the presence of random interactions

    CERN Document Server

    Zhao, Y M; Yoshida, N; Ogawa, K; Yoshinaga, N; Kota, V K B

    2005-01-01

    In this paper we study energy centroids such as those with fixed spin and isospin, those with fixed irreducible representations for bosons, 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 more robust than expected.

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

    DEFF Research Database (Denmark)

    Watt, Dominic; Fabricius, Anne

    2011-01-01

    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......, 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....

  1. Centroid gain compensation in Shack-Hartmann adaptive optics systems with natural or laser guide star

    Science.gov (United States)

    Veran; Herriot

    2000-08-01

    In an adaptive optics system with an undersampled Shack-Hartmann wave-front sensor (WFS), variations in seeing, laser guide star quality, and sodium layer thickness and range distance all combine to vary WFS centroid gain across the pupil during an exposure. While using the minimum of 4 pixels per WFS subaperture improves frame rate and read noise, the WFS centroid gain uncertainty may introduce static aberrations and degrade servo loop phase margin. We present a novel method to estimate and compensate WFS gains of each subaperture individually in real time for both natural and laser guide stars.

  2. Velocity centroids as tracers of the turbulent velocity statistics

    CERN Document Server

    Lazarian, A E A

    2004-01-01

    We use the results of magnetohydrodynamic (MHD) simulations to emulate spectroscopic observations, and produce maps of variations of velocity centroids to study their scaling properties. We compare them with those of the underlying velocity field, and analytic predictions presented in a previous paper (Lazarian & Esquivel 2003). We tested, with success, a criteria for recovering velocity statistics from velocity centroids derived in our previous work. That is, if >> (where S is a 2D map of ``unnormalized'', v velocity, and I integrated intensity map -column density-), then the structure function of the centroids is dominated by the structure function of velocity. We show that it is possible to extract the velocity statistics using centroids for subsonic and mildly supersonic turbulence (e.g. Mach numbers ~2.5). While, towards higher Mach numbers other effects could affect significantly the statistics of centroids.

  3. Improved measurements of RNA structure conservation with generalized centroid estimators

    Directory of Open Access Journals (Sweden)

    Yohei eOkada

    2011-08-01

    Full Text Available Identification of non-protein-coding RNAs (ncRNAs in genomes is acrucial task for not only molecular cell biology but alsobioinformatics. Secondary structures of ncRNAs are employed as a keyfeature of ncRNA analysis since biological functions of ncRNAs aredeeply related to their secondary structures. Although the minimumfree energy (MFE structure of an RNA sequence is regarded as the moststable structure, MFE alone could not be an appropriate measure foridentifying ncRNAs since the free energy is heavily biased by thenucleotide composition. Therefore, instead of MFE itself, severalalternative measures for identifying ncRNAs have been proposed such asthe structure conservation index (SCI and the base pair distance(BPD, both of which employ MFE structures. However, thesemeasurements are unfortunately not suitable for identifying ncRNAs insome cases including the genome-wide search and incur high falsediscovery rate. In this study, we propose improved measurements basedon SCI and BPD, applying generalized centroid estimators toincorporate the robustness against low quality multiple alignments.Our experiments show that our proposed methods achieve higher accuracythan the original SCI and BPD for not only human-curated structuralalignments but also low quality alignments produced by CLUSTALW. Furthermore, the centroid-based SCI on CLUSTAL W alignments is moreaccurate than or comparable with that of the original SCI onstructural alignments generated with RAF, a high quality structuralaligner, for which two-fold expensive computational time is requiredon average. We conclude that our methods are more suitable forgenome-wide alignments which are of low quality from the point of viewon secondary structures than the original SCI and BPD.

  4. Improved measurements of RNA structure conservation with generalized centroid estimators.

    Science.gov (United States)

    Okada, Yohei; Saito, Yutaka; Sato, Kengo; Sakakibara, Yasubumi

    2011-01-01

    Identification of non-protein-coding RNAs (ncRNAs) in genomes is a crucial task for not only molecular cell biology but also bioinformatics. Secondary structures of ncRNAs are employed as a key feature of ncRNA analysis since biological functions of ncRNAs are deeply related to their secondary structures. Although the minimum free energy (MFE) structure of an RNA sequence is regarded as the most stable structure, MFE alone could not be an appropriate measure for identifying ncRNAs since the free energy is heavily biased by the nucleotide composition. Therefore, instead of MFE itself, several alternative measures for identifying ncRNAs have been proposed such as the structure conservation index (SCI) and the base pair distance (BPD), both of which employ MFE structures. However, these measurements are unfortunately not suitable for identifying ncRNAs in some cases including the genome-wide search and incur high false discovery rate. In this study, we propose improved measurements based on SCI and BPD, applying generalized centroid estimators to incorporate the robustness against low quality multiple alignments. Our experiments show that our proposed methods achieve higher accuracy than the original SCI and BPD for not only human-curated structural alignments but also low quality alignments produced by CLUSTAL W. Furthermore, the centroid-based SCI on CLUSTAL W alignments is more accurate than or comparable with that of the original SCI on structural alignments generated with RAF, a high quality structural aligner, for which twofold expensive computational time is required on average. We conclude that our methods are more suitable for genome-wide alignments which are of low quality from the point of view on secondary structures than the original SCI and BPD.

  5. A centroid model of species distribution with applications to the Carolina wren Thryothorus ludovicianus and house finch Haemorhous mexicanus in the United States

    Science.gov (United States)

    Huang, Qiongyu; Sauer, John R.; Swatantran, Anu; Dubayah, Ralph

    2016-01-01

    Drastic shifts in species distributions are a cause of concern for ecologists. Such shifts pose great threat to biodiversity especially under unprecedented anthropogenic and natural disturbances. Many studies have documented recent shifts in species distributions. However, most of these studies are limited to regional scales, and do not consider the abundance structure within species ranges. Developing methods to detect systematic changes in species distributions over their full ranges is critical for understanding the impact of changing environments and for successful conservation planning. Here, we demonstrate a centroid model for range-wide analysis of distribution shifts using the North American Breeding Bird Survey. The centroid model is based on a hierarchical Bayesian framework which models population change within physiographic strata while accounting for several factors affecting species detectability. Yearly abundance-weighted range centroids are estimated. As case studies, we derive annual centroids for the Carolina wren and house finch in their ranges in the U.S. We further evaluate the first-difference correlation between species’ centroid movement and changes in winter severity, total population abundance. We also examined associations of change in centroids from sub-ranges. Change in full-range centroid movements of Carolina wren significantly correlate with snow cover days (r = −0.58). For both species, the full-range centroid shifts also have strong correlation with total abundance (r = 0.65, and 0.51 respectively). The movements of the full-range centroids of the two species are correlated strongly (up to r = 0.76) with that of the sub-ranges with more drastic population changes. Our study demonstrates the usefulness of centroids for analyzing distribution changes in a two-dimensional spatial context. Particularly it highlights applications that associate the centroid with factors such as environmental stressors, population characteristics

  6. A Method for Finding Metabolic Pathways Using Atomic Group Tracking

    Science.gov (United States)

    Zhong, Cheng; Lin, Hai Xiang; Wang, Jianyi

    2017-01-01

    A fundamental computational problem in metabolic engineering is to find pathways between compounds. Pathfinding methods using atom tracking have been widely used to find biochemically relevant pathways. However, these methods require the user to define the atoms to be tracked. This may lead to failing to predict the pathways that do not conserve the user-defined atoms. In this work, we propose a pathfinding method called AGPathFinder to find biochemically relevant metabolic pathways between two given compounds. In AGPathFinder, we find alternative pathways by tracking the movement of atomic groups through metabolic networks and use combined information of reaction thermodynamics and compound similarity to guide the search towards more feasible pathways and better performance. The experimental results show that atomic group tracking enables our method to find pathways without the need of defining the atoms to be tracked, avoid hub metabolites, and obtain biochemically meaningful pathways. Our results also demonstrate that atomic group tracking, when incorporated with combined information of reaction thermodynamics and compound similarity, improves the quality of the found pathways. In most cases, the average compound inclusion accuracy and reaction inclusion accuracy for the top resulting pathways of our method are around 0.90 and 0.70, respectively, which are better than those of the existing methods. Additionally, AGPathFinder provides the information of thermodynamic feasibility and compound similarity for the resulting pathways. PMID:28068354

  7. A new method for finding vacua in string phenomenology

    Energy Technology Data Exchange (ETDEWEB)

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

    2007-05-15

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

  8. 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.

  9. Modified string method for finding minimum energy path

    CERN Document Server

    Samanta, Amit

    2010-01-01

    We present an efficient algorithm to calculate minimum energy path (MEP) and energy barriers between locally minimum points on the multidimensional potential energy surface (PES). Our method dwells the original idea of the String method [Phys. Rev. B 66, 052301 (2002)] to evolve a smooth string along a direction normal to the string. The algorithm works by identifying hyperplanes, at each discretized point, normal to path. The intermediate configurations at these discretized points are then relaxed with their motion confined to their corresponding hyperplanes. Thus the problem of finding MEP on the PES is remodeled as a set of constrained minimization problem. This provides the flexibility of using minimization algorithms faster than the steepest descent method used in the simplified string method [J. Chem. Phys.,126(16),164103 (2007)]. In our method, since each intermediate image relaxes independently, if their step lengths are not controlled kinks can form easily. We propose using a mixing scheme to advance...

  10. Another Method to Find the Derivative of Sine

    Institute of Scientific and Technical Information of China (English)

    Zhang Yuanyi

    2005-01-01

    @@ 1 Introduction It is very important to find the derivative of sine in mathematics. For each derivative of trigonometric functions is begin with sine. The sketch of its proof is transforming two subtracted sine functions into the form of multiplication[1][2][3][4][5][6].But this method appears the form of fraction, so it is difficult for the beginners and the self - learners to understand the increment of the sine function △y[1

  11. 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.

  12. Form-finding methods for deployable mesh reflector antennas

    Institute of Scientific and Technical Information of China (English)

    Li Tuanjie; Jiang Jie; Deng Hanqing; Lin Zhanchao; Wang Zuowei

    2013-01-01

    Deployable high-frequency mesh reflector antennas for future communications and obser-vations are required to obtain high gain and high directivity. In order to support these new missions, reflectors with high surface accuracy are widely required. The form-finding analysis of deployable mesh reflector antennas becomes more vital which aims to determine the initial surface profile formed by the equilibrium prestress distribution in cables to satisfy the surface accuracy requirement. In this paper, two form-finding methods for mesh reflector antennas, both of which include two steps, are pro-posed. The first step is to investigate the prestress design only for the cable net structure as the circum-ferential nodes connected to the supporting truss are assumed fixed. The second step is to optimize the prestress distribution of the boundary cables connected directly to the supporting truss considering the elastic deformation of the antenna structure. Some numerical examples are carried out and the simu-lation results demonstrate the proposed form-finding methods can warrant the deformed antenna reflector surface matches the one by design and the cable tension forces fall in a specified range.

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

    Science.gov (United States)

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

    2012-02-01

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

  14. Statistics of Velocity from Spectral Data Modified Velocity Centroids

    CERN Document Server

    Lazarian, A

    2003-01-01

    We address the problem of studying interstellar (ISM) turbulence using spectral line data. We construct a measure that we term modified velocity centroids (MVCs) and derive an analytical solution that relates the 2D spectra of the modified centroids with the underlying 3D velocity spectrum. We test our results using synthetic maps constructed with data obtained through simulations of compressible MHD turbulence. We prove that the MVCs are able to restore the underlying spectrum of turbulent velocity. We show that the modified velocity centroids (MVCs) are complementary to the the Velocity Channel Analysis (VCA) technique that we introduced earlier. Employed together they make determining of the velocity spectral index more reliable. At the same time we show that MVCs allow to determine velocity spectra when the underlying statistics is not a power law and/or the turbulence is subsonic.

  15. Plasma Channel Diagnostic Based on Laser Centroid Oscillations

    Energy Technology Data Exchange (ETDEWEB)

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

    2010-09-09

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

  16. Research of optical rotation measurement system based on centroid algorithm

    Science.gov (United States)

    Cao, Junjie; Jia, Hongzhi; Shen, Xinrong; Jiang, Shixin

    2016-09-01

    An optical rotation measurement system based on digital signal processor, modulated laser, and step motor rotating stage is established. Centroid algorithm featured fast and simple calculation is introduced to process light signals with or without sample to obtain the optical rotating angle through the step difference between two centroids. The system performance is proved experimentally with standard quartz tubes and glucose solutions. After various measurements, the relative error and precision of the system are determined to 0.4% and 0.004°, which demonstrates the reliable repeatability and high accuracy of whole measurement system.

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

    Science.gov (United States)

    Nevalainen, Jukka; Liivamägi, L. J.; Tempel, E.; Branchini, E.; Roncarelli, M.; Giocoli, C.; Heinämäki, P.; Saar, E.; Bonamente, M.; Einasto, M.; Finoguenov, A.; Kaastra, J.; Lindfors, E.; Nurmi, P.; Ueda, Y.

    2016-10-01

    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) mapping its luminosity into a galaxy luminosity density field, (c) using numerical simulations to relate the luminosity density to the density of the WHIM, (d) applying 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 luminosity density is a reliable signpost for the WHIM. For this reason, our method could be applied to current galaxy surveys to optimise the observational strategies for detecting and studying the WHIM and its properties. Our estimates of the WHIM hydrogen column density N H in Sculptor agree with those obtained via the X-ray analysis. Due to the additional N H estimate, our method has potential for improving the constrains of the physical parameters of the WHIM as derived with X-ray absorption, and thus for improving the understanding of the missing baryons problem.

  18. 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.

  19. Optimal properties of centroid-based classifiers for very high-dimensional data

    CERN Document Server

    Hall, Peter; 10.1214/09-AOS736

    2010-01-01

    We show that scale-adjusted versions of the centroid-based classifier enjoys optimal properties when used to discriminate between two very high-dimensional populations where the principal differences are in location. The scale adjustment removes the tendency of scale differences to confound differences in means. Certain other distance-based methods, for example, those founded on nearest-neighbor distance, do not have optimal performance in the sense that we propose. Our results permit varying degrees of sparsity and signal strength to be treated, and require only mild conditions on dependence of vector components. Additionally, we permit the marginal distributions of vector components to vary extensively. In addition to providing theory we explore numerical properties of a centroid-based classifier, and show that these features reflect theoretical accounts of performance.

  20. Derivation and Comparative Study on Centroid Ranking Value of TrIFN and Apply on Fuzzy Geometric Programming

    Directory of Open Access Journals (Sweden)

    Soham Bandyopadhyay

    2016-03-01

    Full Text Available Ranking fuzzy numbers has become an important process in decision making. Many ranking methods have been proposed thus far and one of the commonly used is centroid of trapezoid. Here we try to derive detail mathematical derivation of centroids of a Trapezoidal Intuitionistic Fuzzy Number along x and y axis. After that we derive the ranking value from two centroid along x and y axis. At the end of the article ranking value on fuzzy geometric programming is used. Here we are dealing with three strong decision making concepts. Intuitionistic trapezoidal fuzzy system is much more decision oriented approach than normal fuzzy number in real life uncertain environment, where we can apply membership and non membership concept for analyzing any real life situation. Ranking value, based on centroid of any Trapezoidal Intuitionistic Fuzzy Number helps for conclusion derivation in quantitative way. We here choose most powerful non linear optimization tool, geometrical programming technique, for generating any decision, using Trapezoidal Intuitionistic Fuzzy Number with centroid ranking approach.

  1. The Centroid of the Symmetrical Kullback-Leibler Distance

    NARCIS (Netherlands)

    Veldhuis, Raymond

    2002-01-01

    This paper discusses the computation of the centroid induced by the symmetrical Kullback-Leibler distance. It is shown that it is the unique zeroing argument of a function which only depends on the arithmetic and the normalized geometric mean of the cluster. An efficient algorithm for its computatio

  2. An Adaptive Connectivity-based Centroid Algorithm for Node Positioning in Wireless Sensor Networks

    Directory of Open Access Journals (Sweden)

    Aries Pratiarso

    2015-06-01

    Full Text Available In wireless sensor network applications, the position of nodes is randomly distributed following the contour of the observation area. A simple solution without any measurement tools is provided by range-free method. However, this method yields the coarse estimating position of the nodes. In this paper, we propose Adaptive Connectivity-based (ACC algorithm. This algorithm is a combination of Centroid as range-free based algorithm, and hop-based connectivity algorithm. Nodes have a possibility to estimate their own position based on the connectivity level between them and their reference nodes. Each node divides its communication range into several regions where each of them has a certain weight depends on the received signal strength. The weighted value is used to obtain the estimated position of nodes. Simulation result shows that the proposed algorithm has up to 3 meter error of estimated position on 100x100 square meter observation area, and up to 3 hop counts for 80 meters' communication range. The proposed algorithm performs an average error positioning up to 10 meters better than Weighted Centroid algorithm. Keywords: adaptive, connectivity, centroid, range-free.

  3. The centroid paradigm: Quantifying feature-based attention in terms of attention filters.

    Science.gov (United States)

    Sun, Peng; Chubb, Charles; Wright, Charles E; Sperling, George

    2016-02-01

    This paper elaborates a recent conceptualization of feature-based attention in terms of attention filters (Drew et al., Journal of Vision, 10(10:20), 1-16, 2010) into a general purpose centroid-estimation paradigm for studying feature-based attention. An attention filter is a brain process, initiated by a participant in the context of a task requiring feature-based attention, which operates broadly across space to modulate the relative effectiveness with which different features in the retinal input influence performance. This paper describes an empirical method for quantitatively measuring attention filters. The method uses a "statistical summary representation" (SSR) task in which the participant strives to mouse-click the centroid of a briefly flashed cloud composed of items of different types (e.g., dots of different luminances or sizes), weighting some types of items more strongly than others. In different attention conditions, the target weights for different item types in the centroid task are varied. The actual weights exerted on the participant's responses by different item types in any given attention condition are derived by simple linear regression. Because, on each trial, the centroid paradigm obtains information about the relative effectiveness of all the features in the display, both target and distractor features, and because the participant's response is a continuous variable in each of two dimensions (versus a simple binary choice as in most previous paradigms), it is remarkably powerful. The number of trials required to estimate an attention filter is an order of magnitude fewer than the number required to investigate much simpler concepts in typical psychophysical attention paradigms.

  4. Methods for Finding Legacy Wells in Large Areas

    Energy Technology Data Exchange (ETDEWEB)

    Hammack, Richard W. [National Energy Technology Lab. (NETL), Pittsburgh, PA, (United States); Veloski, Garret A. [National Energy Technology Lab. (NETL), Pittsburgh, PA, (United States); Hodges, D. Greg [Fugro Airborne Surveys, Mississauga, ON (Canada); White, Jr., Curt M. [National Energy Technology Lab. (NETL), Pittsburgh, PA, (United States)

    2016-06-16

    United States. When abandoned, many wells were not adequately sealed and now provide a potential conduit for the vertical movement of liquids and gases. Today, groundwater aquifers can be contaminated by surface pollutants flowing down wells or by deep, saline water diffusing upwards. Likewise, natural gas, carbon dioxide (CO2), or radon can travel upwards via these wells to endanger structures or human health on the surface. Recently, the need to find and plug wells has become critical with the advent of carbon dioxide injection into geologic formations for enhanced oil recovery (EOR) or carbon storage. The potential for natural gas or brine leakage through existing wells has also been raised as a concern in regions where shale resources are hydraulically fractured for hydrocarbon recovery. In this study, the National Energy Technology Laboratory (NETL) updated existing, effective well finding techniques to be able to survey large areas quickly using helicopter or ground-vehicle-mounted magnetometers, combined with mobile methane detection. For this study, magnetic data were collected using airborne and ground vehicles equipped with two boom-mounted magnetometers, or on foot using a hand-held magnetometer with a single sensor. Data processing techniques were employed to accentuate well-casing-type magnetic signatures. To locate wells with no magnetic signature (wells where the steel well casing had been removed), the team monitored for anomalous concentrations of methane, which could indicate migration of volatile compounds from deeper sedimentary strata along a well or fracture pathway. Methane measurements were obtained using the ALPIS DIfferential Absorption Lidar (DIAL) sensor for helicopter surveys and the Apogee leak detection system (LDS) for ground surveys. These methods were evaluated at a 100-year-old oilfield in Wyoming, where a helicopter magnetic survey accurately located 93% of visible wells. In addition, 20% of the wells found by the survey were

  5. 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 ...

  6. 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...

  7. Centroid precision and orientation precision of planar localization microscopy.

    Science.gov (United States)

    McGray, C; Copeland, C R; Stavis, S M; Geist, J

    2016-09-01

    The concept of localization precision, which is essential to localization microscopy, is formally extended from optical point sources to microscopic rigid bodies. Measurement functions are presented to calculate the planar pose and motion of microscopic rigid bodies from localization microscopy data. Physical lower bounds on the associated uncertainties - termed centroid precision and orientation precision - are derived analytically in terms of the characteristics of the optical measurement system and validated numerically by Monte Carlo simulations. The practical utility of these expressions is demonstrated experimentally by an analysis of the motion of a microelectromechanical goniometer indicated by a sparse constellation of fluorescent nanoparticles. Centroid precision and orientation precision, as developed here, are useful concepts due to the generality of the expressions and the widespread interest in localization microscopy for super-resolution imaging and particle tracking.

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

    Indian Academy of Sciences (India)

    Yun Hua; Feng Qi

    2014-11-01

    In this paper, the authors find the best numbers and such that $\\overline{C}( a+ (1 - )b$, $ b + (1 - )a) < T (a, b) < \\overline{C} ( a + (1 - )b, b + (1 - )a)$ for all , > 0 with ≠ , where $\\overline{C}(a, b) = \\frac{2(a^{2}+ab+b^{2})}{3(a+b)}$ and $T(a, b) = \\frac{2}{} \\int^{/2}_{0}\\sqrt{a^{2}\\cos^{2} + b^{2}\\sin^{2} } {\\rm d}$ denote respectively the centroidal mean and Toader mean of two positive numbers and .

  9. An integrating factor matrix method to find first integrals

    Energy Technology Data Exchange (ETDEWEB)

    Saputra, K V I [Faculty of Science and Mathematics, University Pelita Harapan, Jl. MH Thamrin Boulevard, Tangerang Banten, 15811 (Indonesia); Quispel, G R W [Department of Mathematics and Statistical Science, La Trobe University, Bundoora 3086 (Australia); Van Veen, L, E-mail: kie.saputra@staff.uph.ed [Faculty of Science, University of Ontario Institute of Technology, 2000 Simcoe St N., Oshawa, Ontario, L1H 7K4 (Canada)

    2010-06-04

    In this paper we develop an integrating factor matrix method to derive conditions for the existence of first integrals. We use this novel method to obtain first integrals, along with the conditions for their existence, for two- and three-dimensional Lotka-Volterra systems with constant terms. The results are compared to previous results obtained by other methods.

  10. An integrating factor matrix method to find first integrals

    CERN Document Server

    Saputra, K V I; van Veen, L

    2010-01-01

    In this paper we developed an integrating factor matrix method to derive conditions for the existence of first integrals. We use this novel method to obtain first integrals, along with the conditions for their existence, for two and three dimensional Lotka-Volterra systems with constant terms. The results are compared to previous results obtained by other methods.

  11. Non-obtuse Remeshing with Centroidal Voronoi Tessellation

    KAUST Repository

    Yan, Dongming

    2015-12-03

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

  12. 基于W震相技术的全球强震(MW≥6.5)矩心矩张量自动反演系统评估%Assessment of the automatic centroid moment tensor inversion system for global strong earthquakes (MW≥6 .5)based on the W-phase method

    Institute of Scientific and Technical Information of China (English)

    赵旭; Duputel Zacharie; 黄志斌; 陈宏峰; 赵博

    2014-01-01

    We develop an automatic centroid moment tensor (CMT )inversion system for large earthquakes (MW≥6 .5 )at global scale based on the W-phase method.We use seismic waveforms observed by global virtual seismic networks including Chinese stations,which have been recently set up.To speed up the calculation of moment tensor solutions,the W-phase method is parallelized using openMP.In order to assess the accuracy and timeliness of this implemen-tation,automatic moment tensor solutions for 140 global events (MW6.5-9.0) are determined offline.Compared with the global CMT (GCMT)solutions,the result indicates that this system mentioned is able to precisely retrieve CMT so-lutions of global events with MW≥6 .5 .There is remarkably good linear rela-tionship between the moment magnitude of W-phase CMT and GCMT.The standard deviation of the magnitude differenceΔMW is about 0 .1 3 ,and 9 6 per-cent of the inversions yield a MW within MW-GCMT from the GCMT ± 0 .2 .In comparison with the GCMT solutions,six elements of moment tensors derived show nearly linear distribution along the diagonal,respectively.84 percent of inversions yield a great-circle distance smaller than 50 km between the CMT and GCMT centroids.As shown above,majority of the centroids are very similar with the GCMT centroids.When the data coverage is sufficient,this system can thus automatically determine the CMT of global earthquakes with MW≥6 .5 in between 25 min and 40 min after the origin time.%使用最近构建的虚拟全球地震台网记录的波形数据,采用OpenMP的并行编程技术优化原有算法,研制了基于W震相技术的全球强震(MW≥6.5)矩心矩张量自动反演系统.为了评估该系统的准确度和时效性,将离线自动测定的2008年1月-2013年7月全球140次地震(MW6.5-9.0)的矩心矩张量与全球矩心矩张量工作组(GCMT)的结果进行了比较.结果表明:该系统可准确测定全球MW≥6.5地震的矩张量,绝

  13. 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…

  14. Study of velocity centroids based on the theory of fluctuations in position-position-velocity space

    Science.gov (United States)

    Kandel, D.; Lazarian, A.; Pogosyan, D.

    2017-01-01

    We study the possibility of obtaining power spectrum of gas velocity in the turbulent interstellar medium from spatial correlation of velocity centroids (VCs) of optically thick emission lines. Combining this study with the earlier studies of centroids in Esquivel & Lazarian, we conclude that centroids are applicable for studies of subsonic/transonic turbulence for sufficiently small line-of-sight (LOS) separations at which self-absorption does not affect correlation scalings. At larger LOS separations where self-absorption becomes important, we find that there is a range of scales over which VC correlation demonstrates the universal scaling, similar to the effect found in the velocity channel analysis (VCA). In other words, for large absorptions the VCs lose their ability to reflect the spectra of turbulence. We develop analytical formalism that relates statistical properties of underlying magnetohydrodynamical (MHD) turbulence to observable scaling and anisotropy of VC correlations arising from Alfvén, slow and fast modes that constitute the compressible MHD modes, and show how the VC anisotropy can be used to find the media magnetization as well as to identify and separate the contributions from these MHD modes. Our study demonstrates that VCs are complementary to the VCA. In order to study turbulent volume with insufficient resolution of single-dish telescopes, we demonstrate how the studies of anisotropy can be performed using interferometers. We also suggest that restricted VC can be constructed for absorption lines by integrating LOS velocity weighted by the optical depth. We discuss the requirements for applicability of this approach.

  15. Study of velocity centroids based on the theory of fluctuations in position-position-velocity space

    Science.gov (United States)

    Kandel, D.; Lazarian, A.; Pogosyan, D.

    2016-10-01

    We study the possibility of obtaining power spectrum of gas velocity in the turbulent interstellar medium from spatial correlation of velocity centroids (VC) of optically thick emission lines. Combining our present study with the earlier studies of centroids in Esquivel & Lazarian, we conclude that centroids are applicable for studies of subsonic/transsonic turbulence for sufficiently small line of sight (LOS) separations at which self-absorption does not affect correlation scalings. At larger LOS separations where self-absorption becomes important, we find that there is a range of scales over which VC correlation demonstrates the universal scaling, similar to the effect found in the velocity channel analysis (VCA). In other words, for large absorptions the VC lose their ability to reflect the spectra of turbulence. We develop analytical formalism the relates statistical properties of underlying magnetohydrodynamical turbulence to observable scaling and anisotropy of VC correlations arising from Alfvén, slow and fast modes that constitute the compressible MHD modes, and show how the VC anisotropy can be used to find the media magnetization as well as to identify and separate the contributions from these MHD modes. Our study demonstrates that VC are complementary to the VCA. In order to study turbulent volume with insufficient resolution of single dish telescopes, we demonstrate how the studies of anisotropy can be performed using interferometers. We also suggest that restricted VC can be constructed for absorption lines by integrating line-of-sight velocity weighted by the optical depth. We discuss the requirements for applicability of this approach.

  16. Hough transform method for track finding in center drift chamber

    Science.gov (United States)

    Azmi, K. A. Mohammad Kamal; Wan Abdullah, W. A. T.; Ibrahim, Zainol Abidin

    2016-01-01

    Hough transform is a global tracking method used which had been expected to be faster approach for tracking the circular pattern of electron moving in Center Drift Chamber (CDC), by transforming the point of hit into a circular curve. This paper present the implementation of hough transform method for the reconstruction of tracks in Center Drift Chamber (CDC) which have been generated by random number in C language programming. Result from implementation of this method shows higher peak of circle parameter value (xc,yc,rc) that indicate the similarity value of the parameter needed for circular track in CDC for charged particles in the region of CDC.

  17. Hough transform method for track finding in center drift chamber

    Energy Technology Data Exchange (ETDEWEB)

    Azmi, K. A. Mohammad Kamal, E-mail: khasmidatul@siswa.um.edu.my; Wan Abdullah, W. A. T., E-mail: wat@um.edu.my; Ibrahim, Zainol Abidin [National Centre for Particle Physics, University of Malaya, 50603 Kuala Lumpur (Malaysia)

    2016-01-22

    Hough transform is a global tracking method used which had been expected to be faster approach for tracking the circular pattern of electron moving in Center Drift Chamber (CDC), by transforming the point of hit into a circular curve. This paper present the implementation of hough transform method for the reconstruction of tracks in Center Drift Chamber (CDC) which have been generated by random number in C language programming. Result from implementation of this method shows higher peak of circle parameter value (xc,yc,rc) that indicate the similarity value of the parameter needed for circular track in CDC for charged particles in the region of CDC.

  18. Generalized method for finding community structures in networks

    CERN Document Server

    Chang, Chang

    2013-01-01

    To date, most algorithms aiming to find community structures in networks mainly focus on unipartite or bipartite networks. However, to our knowledge, there is no algorithm specifically designed for the mixture network, a third type defined in our paper that represents a wide range of real-world networks. Interestingly, unipartite and bipartite networks can be viewed as limiting cases of a mixture network, suggesting that the mixture network can be considered as a general condition. Based on this observation, we propose a probabilistic model based on the link community model for a unipartite, undirected network [B. Ball, B. Karrer, and M. E. Newman, Phys. Rev. E 84, 036103 (2011)] by redefining this model in the context of a bipartite network and generalizing the bipartite network version model to a mixture network, the general condition, which can be used to find modules in unipartite, bipartite, and mixture networks in a unified framework. We show that both the model of Ball et al. (unipartite, undirected ne...

  19. Finding function: evaluation methods for functional genomic data

    Directory of Open Access Journals (Sweden)

    Barrett Daniel R

    2006-07-01

    Full Text Available Abstract Background Accurate evaluation of the quality of genomic or proteomic data and computational methods is vital to our ability to use them for formulating novel biological hypotheses and directing further experiments. There is currently no standard approach to evaluation in functional genomics. Our analysis of existing approaches shows that they are inconsistent and contain substantial functional biases that render the resulting evaluations misleading both quantitatively and qualitatively. These problems make it essentially impossible to compare computational methods or large-scale experimental datasets and also result in conclusions that generalize poorly in most biological applications. Results We reveal issues with current evaluation methods here and suggest new approaches to evaluation that facilitate accurate and representative characterization of genomic methods and data. Specifically, we describe a functional genomics gold standard based on curation by expert biologists and demonstrate its use as an effective means of evaluation of genomic approaches. Our evaluation framework and gold standard are freely available to the community through our website. Conclusion Proper methods for evaluating genomic data and computational approaches will determine how much we, as a community, are able to learn from the wealth of available data. We propose one possible solution to this problem here but emphasize that this topic warrants broader community discussion.

  20. A Hamiltonian method for finding broadband modal eigenvalues.

    Science.gov (United States)

    Wang, Haozhong; Wang, Ning; Gao, Dazhi

    2012-02-01

    For shallow water waveguides over a layered elastic bottom, modal eigenvalues can be determined by searching the locations in the complex plane of the horizontal wave number at which the complex phase function is a multiple of π [C. T. Tindle and N. R. Chapman, J. Acoust. Soc. Am. 96, 1777-1782 (1994)]. In this paper, a Hamiltonian method is introduced for tracing the path in the complex plane along which the phase function keeps real. The Hamiltonian method can also be extended to compute the broadband modal eigenvalues or the modal dispersion curves in the Pekeris waveguide with fluid/elastic bottoms. For each proper or leaky normal mode, a different Hamiltonian is constructed in the complex plane and used to trace automatically the complex dispersion curve with the eigenvalue in a reference frequency as the initial value. In contrast to the usual methods, the dispersion curve for each mode is determined individually. The Hamiltonian method shows good performance by comparing with KRAKEN.

  1. 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.)

  2. Our findings, my method: Framing science in televised interviews.

    Science.gov (United States)

    Armon, Rony; Baram-Tsabari, Ayelet

    2016-06-03

    The public communication of science and technology largely depends on its framing in the news media, but scientists' role in this process has only been explored indirectly. This study focuses on storied accounts told by scientists when asked to present their research or provide expert advice in the course of a news interview. A total of 150 items from a current affairs talk show broadcast in the Israeli media were explored through a methodology combining narrative and conversation analysis. Using the concept of framing as originally proposed by Erving Goffman, we show that researchers use personal accounts as a way of reframing news stories introduced by the program hosts. Elements of method and rationale, which are usually considered technical and are shunned in journalistic reports, emerged as a crucial element in the accounts that experts themselves provided. The implications for framing research and science communication training are discussed.

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

    Directory of Open Access Journals (Sweden)

    Simona Tondelli

    2014-05-01

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

  4. Methods for Finding Legacy Wells in Residential and Commercial Areas

    Energy Technology Data Exchange (ETDEWEB)

    Hammack, Richard W. [National Energy Technology Lab. (NETL), Pittsburgh, PA, (United States); Veloski, Garret A. [National Energy Technology Lab. (NETL), Pittsburgh, PA, (United States)

    2016-06-16

    In 1919, the enthusiasm surrounding a short-lived gas play in Versailles Borough, Pennsylvania resulted in the drilling of many needless wells. The legacy of this activity exists today in the form of abandoned, unplugged gas wells that are a continuing source of fugitive methane in the midst of a residential and commercial area. Flammable concentrations of methane have been detected near building foundations, which have forced people from their homes and businesses until methane concentrations decreased. Despite mitigation efforts, methane problems persist and have caused some buildings to be permanently abandoned and demolished. This paper describes the use of magnetic and methane sensing methods by the National Energy Technology Laboratory (NETL) to locate abandoned gas wells in Versailles Borough where site access is limited and existing infrastructure can interfere. Here, wells are located between closely spaced houses and beneath buildings and parking lots. Wells are seldom visible, often because wellheads and internal casing strings have been removed, and external casing has been cut off below ground level. The magnetic survey of Versailles Borough identified 53 strong, monopole magnetic anomalies that are presumed to indicate the locations of steel-cased wells. This hypothesis was tested by excavating the location of one strong, monopole magnetic anomaly that was within an area of anomalous methane concentrations. The excavation uncovered an unplugged gas well that was within 0.2 m of the location of the maximum magnetic signal. Truck-mounted methane surveys of Versailles Borough detected numerous methane anomalies that were useful for narrowing search areas. Methane sources identified during truck-mounted surveys included strong methane sources such as sewers and methane mitigation vents. However, inconsistent wind direction and speed, especially between buildings, made locating weaker methane sources (such as leaking wells) difficult. Walking surveys with

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

    Science.gov (United States)

    Walker, Brent; Michaelides, Angelos

    2010-11-01

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

  6. Centroid estimation in discrete high-dimensional spaces with applications in biology.

    Science.gov (United States)

    Carvalho, Luis E; Lawrence, Charles E

    2008-03-04

    Maximum likelihood estimators and other direct optimization-based estimators dominated statistical estimation and prediction for decades. Yet, the principled foundations supporting their dominance do not apply to the discrete high-dimensional inference problems of the 21st century. As it is well known, statistical decision theory shows that maximum likelihood and related estimators use data only to identify the single most probable solution. Accordingly, unless this one solution so dominates the immense ensemble of all solutions that its probability is near one, there is no principled reason to expect such an estimator to be representative of the posterior-weighted ensemble of solutions, and thus represent inferences drawn from the data. We employ statistical decision theory to find more representative estimators, centroid estimators, in a general high-dimensional discrete setting by using a family of loss functions with penalties that increase with the number of differences in components. We show that centroid estimates are obtained by maximizing the marginal probabilities of the solution components for unconstrained ensembles and for an important class of problems, including sequence alignment and the prediction of RNA secondary structure, whose ensembles contain exclusivity constraints. Three genomics examples are described that show that these estimators substantially improve predictions of ground-truth reference sets.

  7. Ab initio centroid path integral molecular dynamics: Application to vibrational dynamics of diatomic molecular systems

    Science.gov (United States)

    Ohta, Yasuhito; Ohta, Koji; Kinugawa, Kenichi

    2004-01-01

    An ab initio centroid molecular dynamics (CMD) method is developed by combining the CMD method with the ab initio molecular orbital method. The ab initio CMD method is applied to vibrational dynamics of diatomic molecules, H2 and HF. For the H2 molecule, the temperature dependence of the peak frequency of the vibrational spectral density is investigated. The results are compared with those obtained by the ab initio classical molecular dynamics method and exact quantum mechanical treatment. It is shown that the vibrational frequency obtained from the ab initio CMD approaches the exact first excitation frequency as the temperature lowers. For the HF molecule, the position autocorrelation function is also analyzed in detail. The present CMD method is shown to well reproduce the exact quantum result for the information on the vibrational properties of the system.

  8. Photon counting imaging and centroiding with an electron-bombarded CCD using single molecule localisation software

    OpenAIRE

    Hirvonen, Liisa Maija; Barber, Matthew; Suhling, Klaus

    2016-01-01

    Photon event centroiding in photon counting imaging and single-molecule localisation in super-resolution fluorescence microscopy share many traits. Although photon event centroiding has traditionally been performed with simple single-iteration algorithms, we recently reported that iterative fitting algorithms originally developed for single-molecule localisation fluorescence microscopy work very well when applied to centroiding photon events imaged with an MCP-intensified CMOS camera. Here, w...

  9. Regularities with random interactions in energy centroids defined by group symmetries

    CERN Document Server

    Kota, V K B

    2005-01-01

    Regular structures generated by random interactions in energy centroids defined over irreducible representations (irreps) of some of the group symmetries of the interacting boson models $sd$IBM, $sdg$IBM, $sd$IBM-$T$ and $sd$IBM-$ST$ are studied by deriving trace propagations equations for the centroids. It is found that, with random interactions, the lowest and highest group irreps in general carry most of the probability for the corresponding centroids to be lowest in energy. This generalizes the result known earlier, via numerical diagonalization, for the more complicated fixed spin ($J$) centroids where simple trace propagation is not possible.

  10. Shear velocity and wall position determination from particle image velocimetry data with seed centroid correction

    Science.gov (United States)

    Harris, Jeff; Lance, Blake; Skifton, Richard; Smith, Barton

    2015-11-01

    Two methods of computing the wall shear velocity from high-resolution particle image velocimetry (PIV) measurements are compared with and without a correction that accounts for seed gradient near the wall. It is crucial to know the wall position when computing the wall shear stress, but this can be difficult due to laser scatter on a wall. Furthermore, PIV is well known to be biased near walls due to seeding gradients. We compensate for these effects by replacing the cross-stream location of each vector with a value based on the centroid of the seeding in each interrogation region. The shear velocity and wall position resulting from methods outlined in the literature are presented. The boundary layer cases presented are influenced by buoyancy and the efficacy of these methods for convective flow will be discussed.

  11. Simplex-centroid mixture formulation for optimised composting of kitchen waste.

    Science.gov (United States)

    Abdullah, N; Chin, N L

    2010-11-01

    Composting is a good recycling method to fully utilise all the organic wastes present in kitchen waste due to its high nutritious matter within the waste. In this present study, the optimised mixture proportions of kitchen waste containing vegetable scraps (V), fish processing waste (F) and newspaper (N) or onion peels (O) were determined by applying the simplex-centroid mixture design method to achieve the desired initial moisture content and carbon-to-nitrogen (CN) ratio for effective composting process. The best mixture was at 48.5% V, 17.7% F and 33.7% N for blends with newspaper while for blends with onion peels, the mixture proportion was 44.0% V, 19.7% F and 36.2% O. The predicted responses from these mixture proportions fall in the acceptable limits of moisture content of 50% to 65% and CN ratio of 20-40 and were also validated experimentally.

  12. On the applicability of centroid and ring polymer path integral molecular dynamics for vibrational spectroscopy

    Science.gov (United States)

    Witt, Alexander; Ivanov, Sergei D.; Shiga, Motoyuki; Forbert, Harald; Marx, Dominik

    2009-05-01

    Centroid molecular dynamics (CMD) and ring polymer molecular dynamics (RPMD) are two conceptually distinct extensions of path integral molecular dynamics that are able to generate approximate quantum dynamics of complex molecular systems. Both methods can be used to compute quasiclassical time correlation functions which have direct application in molecular spectroscopy; in particular, to infrared spectroscopy via dipole autocorrelation functions. The performance of both methods for computing vibrational spectra of several simple but representative molecular model systems is investigated systematically as a function of temperature and isotopic substitution. In this context both CMD and RPMD feature intrinsic problems which are quantified and investigated in detail. Based on the obtained results guidelines for using CMD and RPMD to compute infrared spectra of molecular systems are provided.

  13. Path integral centroid molecular-dynamics evaluation of vibrational energy relaxation in condensed phase

    Science.gov (United States)

    Poulsen, Jens Aage; Rossky, Peter J.

    2001-11-01

    We present a method based on centroid molecular dynamics (CMD) to calculate nonlinear quantum force correlation functions important in the golden rule approach for studying vibrational energy relaxation (VER) in condensed phases. We consider a model of a diatomic molecule in a two-dimensional neon liquid and also a diatomic coupled to a small Helium cluster. The predictions of the theory for the neon bath are compared and found in close agreement with available theories for VER based on the Egelstaff correction factor and Feynman-Kleinert variational theory. For the Helium cluster, the force spectrum obtained from CMD is found to be in slightly better agreement with the exact result than a method based on a cumulant approach. The results support the use of CMD in condensed phase studies of VER when quantum effects are important.

  14. 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...

  15. A Preliminary Study on the Relation Between the Thermal and Geometric Surface Centroids of the Western Pacific Warm Pool

    Institute of Scientific and Technical Information of China (English)

    FANG Mingqiang

    2006-01-01

    Numerous published results have shown the importance of the Western Pacific Warm Pool (WPWP) surface centroid movement in ENSO-(El Nino/Southern Oscillation) related studies. However, some recent research conclusions make it necessary to clarify the differences of the currently exiting two types of WPWP surface centroid: the geometric centroid and the thermal (heat) centroid. This study analyzes the physical backgrounds of the two types of centroid and points out their differences, which suggest that different types of centroid may serve different study purposes. This study also shows gion sea surface temperature (SST) anomaly and can also be regarded as an important indicator of ENSO events.

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

    CERN Document Server

    Agarwal, Animesh

    2016-01-01

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

  17. Grand-Canonical Adaptive Resolution Centroid Molecular Dynamics: Implementation and application

    Science.gov (United States)

    Agarwal, Animesh; Delle Site, Luigi

    2016-09-01

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

  18. A Direct Algebraic Method in Finding Particular Solutions to Some Nonlinear Evolution Equations

    Institute of Scientific and Technical Information of China (English)

    LIUChun-Ping; CHENJian-Kang; CAIFan

    2004-01-01

    Firstly, a direct algebraic method and a routine way in finding traveling wave solutions to nonlinear evolution equations are explained. And then some new exact solutions for some evolution equations are obtained by using the method.

  19. Finding zeros of nonlinear functions using the hybrid parallel cell mapping method

    Science.gov (United States)

    Xiong, Fu-Rui; Schütze, Oliver; Ding, Qian; Sun, Jian-Qiao

    2016-05-01

    Analysis of nonlinear dynamical systems including finding equilibrium states and stability boundaries often leads to a problem of finding zeros of vector functions. However, finding all the zeros of a set of vector functions in the domain of interest is quite a challenging task. This paper proposes a zero finding algorithm that combines the cell mapping methods and the subdivision techniques. Both the simple cell mapping (SCM) and generalized cell mapping (GCM) methods are used to identify a covering set of zeros. The subdivision technique is applied to enhance the solution resolution. The parallel implementation of the proposed method is discussed extensively. Several examples are presented to demonstrate the application and effectiveness of the proposed method. We then extend the study of finding zeros to the problem of finding stability boundaries of potential fields. Examples of two and three dimensional potential fields are studied. In addition to the effectiveness in finding the stability boundaries, the proposed method can handle several millions of cells in just a few seconds with the help of parallel computing in graphics processing units (GPUs).

  20. Systematic centroid error compensation for the simple Gaussian PSF in an electronic star map simulator

    Institute of Scientific and Technical Information of China (English)

    Wang Haiyong; Wang Yonghai; Li Zhifeng; Song Zhenfei

    2014-01-01

    Simulated star maps serve as convenient inputs for the test of a star sensor, whose stan-dardability mostly depends on the centroid precision of the simulated star image, so it is necessary to accomplish systematic error compensation for the simple Gaussian PSF (or SPSF, in which PSF denotes point spread function). Firstly, the error mechanism of the SPSF is described, the reason of centroid deviations of the simulated star images based on SPSF lies in the unreasonable sampling positions (the centers of the covered pixels) of the Gaussian probability density function. Then in reference to the IPSF simulated star image spots regarded as ideal ones, and by means of normal-ization and numerical fitting, the pixel center offset function expressions are got, so the systematic centroid error compensation can be executed simply by substituting the pixel central position with the offset position in the SPSF. Finally, the centroid precision tests are conducted for the three big error cases of Gaussian radius r=0.5, 0.6, 0.671 pixel, and the centroid accuracy with the compen-sated SPSF (when r=0.5) is improved to 2.83 times that of the primitive SPSF, reaching a 0.008 pixel error, an equivalent level of the IPSF. Besides its simplicity, the compensated SPSF further increases both the shape similarity and the centroid precision of simulated star images, which helps to improve the image quality and the standardability of the outputs of an electronic star map sim-ulator (ESS).

  1. On the Reversibility of Newton-Raphson Root-Finding Method

    Energy Technology Data Exchange (ETDEWEB)

    Perumalla, Kalyan S [ORNL; Wright, John P [ORNL; Kuruganti, Phani Teja [ORNL

    2008-07-01

    Reversibility of a computational method is the ability to execute the method forward as well as backward. Reversible computational methods are generally useful in undoing incorrect computation in a speculative execution setting designed for efficient parallel processing. Here, reversibility is explored of a common component in scientific codes, namely, the Newton-Raphson root-finding method. A reverse method is proposed that is aimed at retracing the sequence of points that are visited by the forward method during forward iterations. When given the root, along with the number of iterations, of the forward method, this reverse method is aimed at backtracking along the reverse sequence of points to finally recover the original starting point of the forward method. The operation of this reverse method is illustrated on a few example functions, serving to highlight the method's strengths and shortcomings.

  2. Finding roots of arbitrary high order polynomials based on neural network recursive partitioning method

    Institute of Scientific and Technical Information of China (English)

    HUANG Deshuang; CHI Zheru

    2004-01-01

    This paper proposes a novel recursive partitioning method based on constrained learning neural networks to find an arbitrary number (less than the order of the polynomial) of (real or complex) roots of arbitrary polynomials. Moreover, this paper also gives a BP network constrained learning algorithm (CLA) used in root-finders based on the constrained relations between the roots and the coefficients of polynomials. At the same time, an adaptive selection method for the parameter δPwith the CLA is also given.The experimental results demonstrate that this method can more rapidly and effectively obtain the roots of arbitrary high order polynomials with higher precision than traditional root-finding approaches.

  3. An analytical method for finding exact solutions of modified Korteweg–de Vries equation

    Directory of Open Access Journals (Sweden)

    Md. Shafiqul Islam

    2015-01-01

    Full Text Available In this present work, we have studied new extension of the (G′/G-expansion method for finding the solitary wave solutions of the modified Korteweg–de Vries (mKdV equation. It has been shown that the proposed method is effective and can be used for many other nonlinear evolution equations (NLEEs in mathematical physics. The obtained results show that the method is very powerful and convenient mathematical tool for nonlinear evolution equations in science and engineering.

  4. Method of the Logistic Function for Finding Analytical Solutions of Nonlinear Differential Equations

    OpenAIRE

    Kudryashov, N. A.

    2015-01-01

    The method of the logistic function is presented for finding exact solutions of nonlinear differential equations. The application of the method is illustrated by using the nonlinear ordinary differential equation of the fourth order. Analytical solutions obtained by this method are presented. These solutions are expressed via exponential functions.logistic function, nonlinear wave, nonlinear ordinary differential equation, Painlev´e test, exact solution

  5. On an Iterative Method for Finding a Zero to the Sum of Two Maximal Monotone Operators

    Directory of Open Access Journals (Sweden)

    Hongwei Jiao

    2014-01-01

    Full Text Available In this paper we consider a problem that consists of finding a zero to the sum of two monotone operators. One method for solving such a problem is the forward-backward splitting method. We present some new conditions that guarantee the weak convergence of the forward-backward method. Applications of these results, including variational inequalities and gradient projection algorithms, are also considered.

  6. Inter-Method Discrepancies in Brain Volume Estimation May Drive Inconsistent Findings in Autism

    Science.gov (United States)

    Katuwal, Gajendra J.; Baum, Stefi A.; Cahill, Nathan D.; Dougherty, Chase C.; Evans, Eli; Evans, David W.; Moore, Gregory J.; Michael, Andrew M.

    2016-01-01

    Previous studies applying automatic preprocessing methods on Structural Magnetic Resonance Imaging (sMRI) report inconsistent neuroanatomical abnormalities in Autism Spectrum Disorder (ASD). In this study we investigate inter-method differences as a possible cause behind these inconsistent findings. In particular, we focus on the estimation of the following brain volumes: gray matter (GM), white matter (WM), cerebrospinal fluid (CSF), and total intra cranial volume (TIV). T1-weighted sMRIs of 417 ASD subjects and 459 typically developing controls (TDC) from the ABIDE dataset were estimated using three popular preprocessing methods: SPM, FSL, and FreeSurfer (FS). Brain volumes estimated by the three methods were correlated but had significant inter-method differences; except TIVSPM vs. TIVFS, all inter-method differences were significant. ASD vs. TDC group differences in all brain volume estimates were dependent on the method used. SPM showed that TIV, GM, and CSF volumes of ASD were larger than TDC with statistical significance, whereas FS and FSL did not show significant differences in any of the volumes; in some cases, the direction of the differences were opposite to SPM. When methods were compared with each other, they showed differential biases for autism, and several biases were larger than ASD vs. TDC differences of the respective methods. After manual inspection, we found inter-method segmentation mismatches in the cerebellum, sub-cortical structures, and inter-sulcal CSF. In addition, to validate automated TIV estimates we performed manual segmentation on a subset of subjects. Results indicate that SPM estimates are closest to manual segmentation, followed by FS while FSL estimates were significantly lower. In summary, we show that ASD vs. TDC brain volume differences are method dependent and that these inter-method discrepancies can contribute to inconsistent neuroimaging findings in general. We suggest cross-validation across methods and emphasize the

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

    Science.gov (United States)

    Ambrosi, R. M.; Hutchinson, I. B.; Hill, J.; Cheruvu, C.; Abbey, A. F.; Short, A. D. T.

    2002-11-01

    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 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 16arcsec at 1.5keV (Nucl. Instr. and Meth. A 488 (2002) 543; SPIE 4140 (2000) 64) and that a centroiding accuracy better that 1arcsec could be achieved within the 4arcmin sampling area designated by the Burst Alert Telescope (Nucl. Instr. and Meth. A 488 (2002) 543). The centroiding accuracy of the Swift XRT's optical components was tested as a function of distance from the focus and off axis position of the PSF (Nucl. Instr. and Meth. A 488 (2002) 543). The presence of background events in the image frame introduced errors in the centroiding process, making the choice of centroiding algorithm important (Nucl. Instr. and Meth. A 488 (2002) 543). Since the objective of Swift is to rapidly investigate the X-ray afterglows of Gamma Ray Bursts the possibility of detecting a bright source with intensity greater than 25 Crab could not be excluded and therefore the impact of a saturated PSF core on the centroiding accuracy was investigated by experimental methods.

  8. Initial data for general relativistic SPH with Centroidal Voronoi Tessellations

    CERN Document Server

    Pablo, Cruz Pérez Juan

    2013-01-01

    In this work we present an alternative method to obtain a distribution of particles over an hyper surface, such that they obey a rest-mass density distribution $\\rho(x^i)$. We use density profiles that can be written as $\\rho(x^1,x^2,x^3)=\\rho(x^1) \\rho(x^2) \\rho(x^3)$ in order to be able to use them as a probability density functions. We can find the relation between the chart $x^j$ and a uniform random variable $\\bar{x}^j \\in (0,1)$, say $F(x^j)=\\bar{x}^j$. Using the inverse of this function we relate a set of $N$ arbitrary number of points inside a cube with coordinates $\\{ x^j =F^{-1}(\\bar{x}^j)\\}$ giving the position in order to get the density distribution $\\rho(x^j)$. We get some noise due to the random distribution and we can notice that each time we relax the configuration on the cube we also get a better distribution of the desired physical configuration described with $\\rho(x^j)$. This relaxation of the position of the particles in the cube has been performed a Lloyd's algorithm in 3D and we have u...

  9. Very Fast Characterization of Focal Mechanism Parameters Through W-Phase Centroid Inversion in the Context of Tsunami Warning

    Science.gov (United States)

    Roch, Julien; Duperray, Pierre; Schindelé, François

    2016-12-01

    Most of the tsunami potential seismic sources in the NEAM region are in a magnitude range of 6.5 ≤ Mw ≤ 7.5 (e.g. the tsunami triggered by the Boumerdes earthquake of 2003 with Mw=6.9). The CENtre d'ALerte aux Tsunamis (CENALT), in operation since 2012 as the French National Tsunami Warning Centre (NTWC) and Candidate Tsunami Service Provider (CTSP), has to issue warning messages within 15 min of earthquake origin time. These warnings are based on the seismic source parameters (Mw magnitude, focal depth and type of fault), which are computed by focal mechanisms and centroid inversion methods. The W-phase method, developed by Kanamori and Rivera, allows quick computation of seismic source parameters due to the early arrival time between P-waves and surface waves, and is therefore particularly useful for monitoring. We assess the W-phase method with 29 events of magnitude M_w ≥ 5.8 for the period 2010-2015 in the NEAM region. Results with 10 min of signal length are in good agreement compared to the Global Centroid Moment Tensor (GCMT) catalog.

  10. 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).

  11. "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…

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

    DEFF Research Database (Denmark)

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

    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 harmon...

  13. A von Neumann Alternating Method for Finding Common Solutions to Variational Inequalities

    CERN Document Server

    Censor, Yair; Reich, Simeon

    2012-01-01

    Modifying von Neumann's alternating projections algorithm, we obtain an alternating method for solving the recently introduced Common Solutions to Variational Inequalities Problem (CSVIP). For simplicity, we mainly confine our attention to the two-set CSVIP, which entails finding common solutions to two unrelated variational inequalities in Hilbert space.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    1987-02-01

    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.

  15. Optimization of Carboxymethyl-Xyloglucan-Based Tramadol Matrix Tablets Using Simplex Centroid Mixture Design

    Directory of Open Access Journals (Sweden)

    Ashwini R. Madgulkar

    2013-01-01

    Full Text Available The aim was to determine the release-modifying effect of carboxymethyl xyloglucan for oral drug delivery. Sustained release matrix tablets of tramadol HCl were prepared by wet granulation method using carboxymethyl xyloglucan as matrix forming polymer. HPMC K100M was used in a small amount to control the burst effect which is most commonly seen with natural hydrophilic polymers. A simplex centroid design with three independent variables and two dependent variables was employed to systematically optimize drug release profile. Carboxymethyl xyloglucan , HPMC K100M , and dicalcium phosphate were taken as independent variables. The dependent variables selected were percent of drug release at 2nd hour and at 8th hour . Response surface plots were developed, and optimum formulations were selected on the basis of desirability. The formulated tablets showed anomalous release mechanism and followed matrix drug release kinetics, resulting in regulated and complete release from the tablets within 8 to 10 hours. The polymer carboxymethyl xyloglucan and HPMC K100M had significant effect on drug release from the tablet (. Polynomial mathematical models, generated for various response variables using multiple regression analysis, were found to be statistically significant (. The statistical models developed for optimization were found to be valid.

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

    Science.gov (United States)

    Ota, Mamoru; Kasahara, Yoshiya; Goto, Yoshitaka

    2015-07-01

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

  17. Velocity centroids and the structure of interstellar turbulence: I. Analytical study

    CERN Document Server

    Levrier, F

    2004-01-01

    We present an analytical study of the statistical properties of integrated emission and velocity centroids for a slightly compressible turbulent slab model, to retrieve the underlying statistics of three-dimensional density and velocity fluctuations. Under the assumptions that the density and velocity fields are homogeneous and isotropic, we derive the expressions of the antenna temperature for an optically thin spectral line observation, and of its successive moments with respect to the line of sight velocity component, focusing on the zeroth (intensity or integrated emission I) and first (non-normalized velocity centroid C) moments. The ratio of the latter to the former is the normalized centroid C_0, whose expression can be linearized for small density fluctuations. To describe the statistics of I, C and C_0, we derive expansions of their autocorrelation functions in powers of density fluctuations and perform a lowest-order real-space calculation of their scaling behaviour, assuming that the density and ve...

  18. Estimation Normal Vector of Triangular Mesh Vertex by Angle and Centroid Weights and its Application

    Directory of Open Access Journals (Sweden)

    Yueping Chen

    2013-04-01

    Full Text Available To compute vertex normal of triangular meshes more accurately, this paper presents an improved algorithm based on angle and centroid weights. Firstly, four representational algorithms are analyzed by comparing their weighting characteristics such as angles, areas and centroids. The drawbacks of each algorithm are discussed. Following that, an improved algorithm is put forward based on angle and centroid weights. Finally, by taking the deviation angle between the nominal normal vector and the estimated one as the error evaluation standard factor, the triangular mesh models of spheres, ellipsoids, paraboloids and cylinders are used to analyze the performance of all these estimation algorithms. The machining and inspection operations of one mould part are conducted to verify the improved algorithm. Experimental results demonstrate that the algorithm is effective.

  19. 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...

  20. Performance of centroiding algorithms at low light level conditions in adaptive optics

    CERN Document Server

    Vyas, Akondi; Prasad, B Raghavendra; 10.1109/ARTCom.2009.30

    2010-01-01

    The performance metrics of different centroiding algorithms at low light level conditions were optimized in the case of a Shack Hartmann Sensor (SHS) for efficient performance of the adaptive optics system. For short exposures and low photon flux, the Hartmann spot does not have a Gaussian shape due to the photon noise which follows Poissonian statistics. The centroiding estimation error was calculated at different photon levels in the case of changing spot size and shift in the spot using Monte Carlo simulations. This analysis also proves to be helpful in optimizing the SHS specifications at low light levels.

  1. Analysis of optimal centroid estimation applied to Shack-Hartmann sensing.

    Science.gov (United States)

    Irwan, R; Lane, R G

    1999-11-10

    The problem of estimating the centroid of an incoherently imaged point with a CCD array is analyzed. An exact analysis is presented that uses the actual short-exposure function at the CCD instead of the traditional Gaussian approximation. The analysis shows that, for Poisson noise, the centroid variance depends on the CCD size and that truncation effects play a significant part in determining the optimum CCD size. The effects of this on a wave-front reconstruction formed by a Shack-Hartmann sensor are described.

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

    Directory of Open Access Journals (Sweden)

    Yide Wang

    2005-01-01

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

  3. Calculation method on shape finding of self-anchored suspension bridge with spatial cables

    Institute of Scientific and Technical Information of China (English)

    Yan HAN; Zhengqing CHEN; Shidong LUO; Shankui YANG

    2009-01-01

    Based on the spatial model, a reliable and accurate calculation method on the shape finding of self anchored suspension bridge with spatial cables was studiedin this paper. On the principle that the shape of the main cables between hangers is catenary, the iteration method of calculating the shapes of the spatial main cables under the load of hanger forces was deduced. The reasonable position of the saddle was determined according to the shape and the theoretical joint point of the main cables. The shapes of the main cables at completed cable stage werecalculated based on the unchanging principle of the zero-stress lengths of the main cables. By using a numerical method combining with the finite element method, one self-anchored suspension bridge with spatial cables was analyzed. The zero-stress length of the main cables, the position of the saddle, and the pre-offsetting of the saddle of the self-anchored suspension bridge were given. The reasonable shapes of the main cables at bridge completion stage and completed cable stage were presented. The results show that the shape-finding calculation method is effective and reliable.

  4. Initial periodontal screening and radiographic findings - A comparison of two methods to evaluate the periodontal situation

    Directory of Open Access Journals (Sweden)

    Hornecker Else

    2011-01-01

    Full Text Available Abstract Background The periodontal screening index (PSI is an element of the initial dental examination. The PSI provides information on the periodontal situation and allows a first estimation of the treatment required. The dental panoramic tomography (DPT indicates the proximal bone loss, thus also allowing conclusions on the periodontal situation. In this study, the results of both methods in determining the periodontal situation are compared. Methods The clinical examination covered DMF-T, QHI, and PSI scores at four proximal sites per tooth; the examining dentist was unaware of the radiographic finding. Based on the PSI scores, the findings were diagnosed as follows: score 0 - 2 "no periodontitis", score 3 and 4 "periodontitis". Independent of the locality and time of the clinical evaluation, two dentists examined the DPTs of the subjects. The results were classified as follows: no bone loss = "no periodontitis", and bone loss = "periodontitis". Results 112 male subjects (age 18 to 58, Ø 37.7 ± 8 years were examined. Regarding the PSI, 17 subjects were diagnosed "no periodontitis" and 95 subjects "periodontitis". According to the evaluation of the DPTs, 70 subjects were diagnosed "no periodontitis" and 42 "periodontitis". A comparison of both methods revealed that the diagnosis "no periodontitis" corresponded in 17 cases and "periodontitis" in 42 cases (53%. In 47% (53 cases the results were not congruent. The difference between both methods was statistically significant (p Conclusion The present study shows that the initial assessment of the periodontal situation significantly depends on the method of evaluation.

  5. Monte Carlo Evaluation of a New Track-Finding Method for the VENUS Muon Detector

    Science.gov (United States)

    Asano, Yuzo; Hatanaka, Makoto; Koseki, Tadashi; Mori, Shigeki; Shirakata, Masashi; Yamamoto, Kazumichi

    1989-10-01

    A new method of finding a track is devised for the VENUS muon detector composed of eight-cell drift-tube modules, each cell having a rectangular cross section of 5× 7 cm2. The new method, in which fourth-order equations are solved by the Ferarri-Cardano method, is especially powerful for a track having a large incident angle with respect to the line normal to the anode-wire plane of a drift tube, compared to the presently used method in which a track is determined by the intersecting points of an equi-drift-distance circle and the anode-wire plane. Cosmic-ray test data for the forward-backward part muon detector support these simulation results.

  6. Monte Carlo evaluation of a new track-finding method for the VENUS muon detector

    Energy Technology Data Exchange (ETDEWEB)

    Asano, Yuzo; Hatanaka, Makoto; Koseki, Tadashi; Mori, Shigeki; Shirakata, Masashi; Yamamoto, Kazumichi (Tsukuba Univ., Ibaraki (Japan). Inst. of Applied Physics)

    1989-10-01

    A new method of finding a track is devised for the VENUS muon detector composed of eight-cell drift-tube modules, each cell having a rectangular cross section of 5 x 7 cm{sup 2}. The new method, in which fourth-order equations are solved by the Ferarri-Cardano method, is especially powerful for a track having a large incident angle with respect to the line normal to the anode-wire plane of a drift tube, compared to the presently used method in which a track is determined by the intersecting points of an equi-drift-distance circle and the anode-wire plane. Cosmic-ray test data for the forward-backward part muon detector support these simulation results. (author).

  7. Fast Simulators for Satellite Cloud Optical Centroid Pressure Retrievals, 1. Evaluation of OMI Cloud Retrievals

    Science.gov (United States)

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

    2012-01-01

    The cloud Optical Centroid Pressure (OCP), also known as the effective cloud pressure, is a satellite-derived parameter that is commonly used in trace-gas retrievals to account for the effects of clouds on near-infrared through ultraviolet radiance measurements. Fast simulators are desirable to further expand the use of cloud OCP retrievals into the operational and climate communities for applications such as data assimilation and evaluation of cloud vertical structure in general circulation models. In this paper, we develop and validate fast simulators that provide estimates of the cloud OCP given a vertical profile of optical extinction. We use a pressure-weighting scheme where the weights depend upon optical parameters of clouds and/or aerosol. A cloud weighting function is easily extracted using this formulation. We then use fast simulators to compare two different satellite cloud OCP retrievals from the Ozone Monitoring Instrument (OMI) with estimates based on collocated cloud extinction profiles from a combination of CloudS at radar and MODIS visible radiance data. These comparisons are made over a wide range of conditions to provide a comprehensive validation of the OMI cloud OCP retrievals. We find generally good agreement between OMI cloud OCPs and those predicted by CloudSat. However, the OMI cloud OCPs from the two independent algorithms agree better with each other than either does with the estimates from CloudSat/MODIS. Differences between OMI cloud OCPs and those based on CloudSat/MODIS may result from undetected snow/ice at the surface, cloud 3-D effects, low altitude clouds missed by CloudSat, and the fact that CloudSat only observes a relatively small fraction of an OMI field-of-view.

  8. Synthetic cathinone pharmacokinetics, analytical methods, and toxicological findings from human performance and postmortem cases.

    Science.gov (United States)

    Ellefsen, Kayla N; Concheiro, Marta; Huestis, Marilyn A

    2016-05-01

    Synthetic cathinones are commonly abused novel psychoactive substances (NPS). We present a comprehensive systematic review addressing in vitro and in vivo synthetic cathinone pharmacokinetics, analytical methods for detection and quantification in biological matrices, and toxicological findings from human performance and postmortem toxicology cases. Few preclinical administration studies examined synthetic cathinone pharmacokinetic profiles (absorption, distribution, metabolism, and excretion), and only one investigated metabolite pharmacokinetics. Synthetic cathinone metabolic profiling studies, primarily with human liver microsomes, elucidated metabolite structures and identified suitable biomarkers to extend detection windows beyond those provided by parent compounds. Generally, cathinone derivatives underwent ketone reduction, carbonylation of the pyrrolidine ring, and oxidative reactions, with phase II metabolites also detected. Reliable analytical methods are necessary for cathinone identification in biological matrices to document intake and link adverse events to specific compounds and concentrations. NPS analytical methods are constrained in their ability to detect new emerging synthetic cathinones due to limited commercially available reference standards and continuous development of new analogs. Immunoassay screening methods are especially affected, but also gas-chromatography and liquid-chromatography mass spectrometry confirmation methods. Non-targeted high-resolution-mass spectrometry screening methods are advantageous, as they allow for retrospective data analysis and easier addition of new synthetic cathinones to existing methods. Lack of controlled administration studies in humans complicate interpretation of synthetic cathinones in biological matrices, as dosing information is typically unknown. Furthermore, antemortem and postmortem concentrations often overlap and the presence of other psychoactive substances are typically found in combination

  9. Centroid and Theoretical Rotation: Justification for Their Use in Q Methodology Research

    Science.gov (United States)

    Ramlo, Sue

    2016-01-01

    This manuscript's purpose is to introduce Q as a methodology before providing clarification about the preferred factor analytical choices of centroid and theoretical (hand) rotation. Stephenson, the creator of Q, designated that only these choices allowed for scientific exploration of subjectivity while not violating assumptions associated with…

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

    Science.gov (United States)

    Xiong, Kun; Jiang, Jie

    2015-01-01

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

  11. 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.

  12. Select and Cluster: A Method for Finding Functional Networks of Clustered Voxels in fMRI

    Science.gov (United States)

    DonGiovanni, Danilo

    2016-01-01

    Extracting functional connectivity patterns among cortical regions in fMRI datasets is a challenge stimulating the development of effective data-driven or model based techniques. Here, we present a novel data-driven method for the extraction of significantly connected functional ROIs directly from the preprocessed fMRI data without relying on a priori knowledge of the expected activations. This method finds spatially compact groups of voxels which show a homogeneous pattern of significant connectivity with other regions in the brain. The method, called Select and Cluster (S&C), consists of two steps: first, a dimensionality reduction step based on a blind multiresolution pairwise correlation by which the subset of all cortical voxels with significant mutual correlation is selected and the second step in which the selected voxels are grouped into spatially compact and functionally homogeneous ROIs by means of a Support Vector Clustering (SVC) algorithm. The S&C method is described in detail. Its performance assessed on simulated and experimental fMRI data is compared to other methods commonly used in functional connectivity analyses, such as Independent Component Analysis (ICA) or clustering. S&C method simplifies the extraction of functional networks in fMRI by identifying automatically spatially compact groups of voxels (ROIs) involved in whole brain scale activation networks. PMID:27656202

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

    DEFF Research Database (Denmark)

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

    2014-01-01

    ). 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......'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...

  14. A semiclassical approach to the dynamics of many-body Bose/Fermi systems by the path integral centroid molecular dynamics

    Science.gov (United States)

    Kinugawa, Kenichi; Nagao, Hidemi; Ohta, Koji

    2001-01-01

    We present a formalism of the path integral centroid molecular dynamics (CMD) extended to Bose and Fermi statistics as a semiclassical approach to explore the dynamics of quantum many-body systems. The validity of the method is examined in relation to the time correlation functions. The presently proposed scheme, refined from our previous derivation [Chem. Phys. Lett. 307, 187 (1999)], is aimed at the calculations of not the exact quantum-mechanical dynamics but the semiclassical dynamics under certain approximations. The formalism is based on the projection operator with which the Bose/Fermi system is mapped onto a particular type of pseudo-Boltzmann system. In the pseudo-Boltzmann system the correlation due to the Bose/Fermi statistics is introduced via an extra pseudopotential called the permutation potential and its relevant operator. Using the present semiclassical formalism, the time correlation function of centroid position, which is evaluated from the CMD trajectories in the pseudo-Boltzmann system, is an approximation to the Kubo canonical correlation function of position operator of the exact quantum-statistical system composed of bosons or fermions. There is no such apparent relation between the momentum operator and the corresponding momentum centroid.

  15. Finding Planets in K2: A New Method of Cleaning the Data

    Science.gov (United States)

    Currie, Miles; Mullally, Fergal; Thompson, Susan E.

    2017-01-01

    We present a new method of removing systematic flux variations from K2 light curves by employing a pixel-level principal component analysis (PCA). This method decomposes the light curves into its principal components (eigenvectors), each with an associated eigenvalue, the value of which is correlated to how much influence the basis vector has on the shape of the light curve. This method assumes that the most influential basis vectors will correspond to the unwanted systematic variations in the light curve produced by K2’s constant motion. We correct the raw light curve by automatically fitting and removing the strongest principal components. The strongest principal components generally correspond to the flux variations that result from the motion of the star in the field of view. Our primary method of calculating the strongest principal components to correct for in the raw light curve estimates the noise by measuring the scatter in the light curve after using an algorithm for Savitsy-Golay detrending, which computes the combined photometric precision value (SG-CDPP value) used in classic Kepler. We calculate this value after correcting the raw light curve for each element in a list of cumulative sums of principal components so that we have as many noise estimate values as there are principal components. We then take the derivative of the list of SG-CDPP values and take the number of principal components that correlates to the point at which the derivative effectively goes to zero. This is the optimal number of principal components to exclude from the refitting of the light curve. We find that a pixel-level PCA is sufficient for cleaning unwanted systematic and natural noise from K2’s light curves. We present preliminary results and a basic comparison to other methods of reducing the noise from the flux variations.

  16. Finding fatigue resistant and lightweight designs using the optimization methods CAO and SKO

    Science.gov (United States)

    Mattheck, C.; Walther, Frank; Baumgartner, A.

    1992-07-01

    Computer Aided Optimization (CAO), a new method of shape optimization based on the computer simulation of biological growth and Soft Kill Option (SKO), and a strategy to find new design solutions with reduced weight are presented. CAO is used to improve the design of technical components by gaining a homogenized stress distribution on the surface of two and three dimensional finite element models. SKO helps to define new topologies starting from a general oversized 'design area'. With CAO it is also possible to simulate the 'adaptive growth' of biological load carriers, while SKO simulates the mineralization process of bones adapted to their loading. The main ideas of the methods are outlined and several examples of optimizations are shown. If completely new solutions for technical problems are desired, SKO is used first and the design proposal being found is then optimized by CAO in order to achieve a lightweight and fatigue resistant design. The efficiency of the combination of the two methods as a complete layout procedure is shown.

  17. GeneWaltz--A new method for reducing the false positives of gene finding

    Directory of Open Access Journals (Sweden)

    Misawa Kazuharu

    2010-09-01

    Full Text Available Abstract Background Identifying protein-coding regions in genomic sequences is an essential step in genome analysis. It is well known that the proportion of false positives among genes predicted by current methods is high, especially when the exons are short. These false positives are problematic because they waste time and resources of experimental studies. Methods We developed GeneWaltz, a new filtering method that reduces the risk of false positives in gene finding. GeneWaltz utilizes a codon-to-codon substitution matrix that was constructed by comparing protein-coding regions from orthologous gene pairs between mouse and human genomes. Using this matrix, a scoring scheme was developed; it assigned higher scores to coding regions and lower scores to non-coding regions. The regions with high scores were considered candidate coding regions. One-dimensional Karlin-Altschul statistics was used to test the significance of the coding regions identified by GeneWaltz. Results The proportion of false positives among genes predicted by GENSCAN and Twinscan were high, especially when the exons were short. GeneWaltz significantly reduced the ratio of false positives to all positives predicted by GENSCAN and Twinscan, especially when the exons were short. Conclusions GeneWaltz will be helpful in experimental genomic studies. GeneWaltz binaries and the matrix are available online at http://en.sourceforge.jp/projects/genewaltz/.

  18. THE USE OF THE PATENT ANALYSIS METHOD FOR FINDING ANALOGUES AND PROTOTYPES OF RECEIVED TECHNICAL SOLUTIONS

    Directory of Open Access Journals (Sweden)

    Irina Petrova

    2016-03-01

    Full Text Available The research deals with the issue of the patent analysis efficiency, which is a necessary stage of seaching analogues and prototypes to obtain technical solutions. The article presents the results of analyzing the present automation systems for finding necessary information in the patent databases and identifies their advantages and disadvantages. It gives a description of the “Intellect” system, which is an example of software systems for the conceptual design stage support. Materials and Methods The article presents some of the possible ways to organize the patents-analogues search process and specific features of searching analogues and prototypes for the generated parametric structure scheme of the technical solution, which is the result of the synthesis of a new information-measuring and control system element in the “Intellect” system. The description of the proposed search query forming method is given. The article gives the structure of the patent passport, which must be stored in a database to organize the process of searcing analogues and prototypes. There given a description of algorithms for automatic adding a patent to the database, recalculating the weights while adding a patent by experts, identifying the fact of using different physical and technical effects in a patent. Results The final part of the article contains an example of the results of testing the developed subsystem implementing the proposed method. According to the test results it is concluded that the selected software and algorithmic solutions are effective.

  19. The Polynomial Pivots as Initial Values for a New Root-Finding Iterative Method

    Directory of Open Access Journals (Sweden)

    Mario Lázaro

    2015-01-01

    Full Text Available A new iterative method for polynomial root-finding based on the development of two novel recursive functions is proposed. In addition, the concept of polynomial pivots associated with these functions is introduced. The pivots present the property of lying close to some of the roots under certain conditions; this closeness leads us to propose them as efficient starting points for the proposed iterative sequences. Conditions for local convergence are studied demonstrating that the new recursive sequences converge with linear velocity. Furthermore, an a priori checkable global convergence test inside pivots-centered balls is proposed. In order to accelerate the convergence from linear to quadratic velocity, new recursive functions together with their associated sequences are constructed. Both the recursive functions (linear and the corrected (quadratic convergence are validated with two nontrivial numerical examples. In them, the efficiency of the pivots as starting points, the quadratic convergence of the proposed functions, and the validity of the theoretical results are visualized.

  20. 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.

  1. 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.

  2. Several Methods of Finding Inverse matrix%求逆矩阵的几种方法

    Institute of Scientific and Technical Information of China (English)

    俞美华

    2015-01-01

    [Abstract]Matrix is the main object of study in linear algebra and research tool and the inverse matrix is a very important concept in the theory of matrix, how to judge a matrix is reversible and how to calculate the inverse matrix are very important. There are a lot of methods of finding the inverse of a matrix, this paper sums up the following: the methods of definition,adjoint matrix, the nature of the matrix inverse,elementary transformation,block diagonal matrix.%矩阵是线性代数中的主要研究对象与研究工具,而逆矩阵是矩阵理论中的一个非常重要的概念,如何判断一个矩阵是否可逆以及如何求矩阵的逆矩阵就显得非常重要。求逆矩阵方法很多,本文归纳了如下几种:定义法;利用伴随矩阵求逆法;利用伴随矩阵求逆法的推论求逆;利用逆矩阵的性质求逆法;利用矩阵的初等变换求逆;分块对角阵求逆法。

  3. The Dietary Patterns Methods Project: Synthesis of Findings across Cohorts and Relevance to Dietary Guidance1234

    Science.gov (United States)

    Liese, Angela D; Krebs-Smith, Susan M; Subar, Amy F; George, Stephanie M; Harmon, Brook E; Neuhouser, Marian L; Boushey, Carol J; Schap, TusaRebecca E; Reedy, Jill

    2015-01-01

    The Dietary Patterns Methods Project (DPMP) was initiated in 2012 to strengthen research evidence on dietary indices, dietary patterns, and health for upcoming revisions of the Dietary Guidelines for Americans, given that the lack of consistent methodology has impeded development of consistent and reliable conclusions. DPMP investigators developed research questions and a standardized approach to index-based dietary analysis. This article presents a synthesis of findings across the cohorts. Standardized analyses were conducted in the NIH-AARP Diet and Health Study, the Multiethnic Cohort, and the Women’s Health Initiative Observational Study (WHI-OS). Healthy Eating Index 2010, Alternative Healthy Eating Index 2010 (AHEI-2010), alternate Mediterranean Diet, and Dietary Approaches to Stop Hypertension (DASH) scores were examined across cohorts for correlations between pairs of indices; concordant classifications into index score quintiles; associations with all-cause, cardiovascular disease (CVD), and cancer mortality with the use of Cox proportional hazards models; and dietary intake of foods and nutrients corresponding to index quintiles. Across all cohorts in women and men, there was a high degree of correlation and consistent classifications between index pairs. Higher diet quality (top quintile) was significantly and consistently associated with an 11–28% reduced risk of death due to all causes, CVD, and cancer compared with the lowest quintile, independent of known confounders. This was true for all diet index–mortality associations, with the exception of AHEI-2010 and cancer mortality in WHI-OS women. In all cohorts, survival benefit was greater with a higher-quality diet, and relatively small intake differences distinguished the index quintiles. The reductions in mortality risk started at relatively lower levels of diet quality. Higher scores on each of the indices, signifying higher diet quality, were associated with marked reductions in mortality

  4. The Dietary Patterns Methods Project: synthesis of findings across cohorts and relevance to dietary guidance.

    Science.gov (United States)

    Liese, Angela D; Krebs-Smith, Susan M; Subar, Amy F; George, Stephanie M; Harmon, Brook E; Neuhouser, Marian L; Boushey, Carol J; Schap, TusaRebecca E; Reedy, Jill

    2015-03-01

    The Dietary Patterns Methods Project (DPMP) was initiated in 2012 to strengthen research evidence on dietary indices, dietary patterns, and health for upcoming revisions of the Dietary Guidelines for Americans, given that the lack of consistent methodology has impeded development of consistent and reliable conclusions. DPMP investigators developed research questions and a standardized approach to index-based dietary analysis. This article presents a synthesis of findings across the cohorts. Standardized analyses were conducted in the NIH-AARP Diet and Health Study, the Multiethnic Cohort, and the Women's Health Initiative Observational Study (WHI-OS). Healthy Eating Index 2010, Alternative Healthy Eating Index 2010 (AHEI-2010), alternate Mediterranean Diet, and Dietary Approaches to Stop Hypertension (DASH) scores were examined across cohorts for correlations between pairs of indices; concordant classifications into index score quintiles; associations with all-cause, cardiovascular disease (CVD), and cancer mortality with the use of Cox proportional hazards models; and dietary intake of foods and nutrients corresponding to index quintiles. Across all cohorts in women and men, there was a high degree of correlation and consistent classifications between index pairs. Higher diet quality (top quintile) was significantly and consistently associated with an 11-28% reduced risk of death due to all causes, CVD, and cancer compared with the lowest quintile, independent of known confounders. This was true for all diet index-mortality associations, with the exception of AHEI-2010 and cancer mortality in WHI-OS women. In all cohorts, survival benefit was greater with a higher-quality diet, and relatively small intake differences distinguished the index quintiles. The reductions in mortality risk started at relatively lower levels of diet quality. Higher scores on each of the indices, signifying higher diet quality, were associated with marked reductions in mortality. Thus

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

    Science.gov (United States)

    Fields, J. M.

    1985-01-01

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

  6. Findings, theories and methods in the study of children's national identifications and national attitudes

    NARCIS (Netherlands)

    Barrett, M.; 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 p

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

    Directory of Open Access Journals (Sweden)

    Samandari Ghazaleh

    2011-09-01

    Full Text Available 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. The population-based sample comprises 389 teens ages 13-17 giving birth to a live born infant in North Carolina in 2000 - 2005 and in 2007. Qualitative analyses are based on in-depth interviews with 22 Black, White and Hispanic teen mothers residing in rural and urban areas of North Carolina conducted between November 2007 and February 2009. Results In quantitative analyses, 52% (196 of 389 of North Carolina teen mothers initiated breastfeeding, but half of those who initiated breastfeeding (92/196 stopped within the first month postpartum. Hispanic teens (44/52 or 89% were much more likely than Black (61/159 or 41% or White teens (87/164 or 52% to initiate breastfeeding and to continue for a longer duration. Nearly sixty two percent (29/52 of Hispanic respondents breastfed for greater than four weeks as compared to 16% (29/159 of Black respondents and 26% (39/164 of White respondents. Common barriers to breastfeeding initiation and continuation included not liking breastfeeding, returning to school, nipple pain, and insufficient milk. Qualitative data provided context for the quantitative findings, elucidating the barriers and facilitators to breastfeeding from the teens' perspective and insight into the ways in which breastfeeding support to teens could be enhanced. Conclusions The large number of adolescents ceasing breastfeeding within the first month points to the need for more individualized follow-up after hospital discharge in the first few days

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

    Science.gov (United States)

    Wagner, Karla D; Davidson, Peter J; Pollini, Robin A; Strathdee, Steffanie A; Washburn, Rachel; Palinkas, Lawrence A

    2012-01-01

    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 between methods. Cases in which findings from different methods are congruous are generally thought of as ideal, whilst conflicting findings may, at first glance, appear problematic. However, the latter situation provides the opportunity for a process through which apparently discordant results are reconciled, potentially leading to new emergent understandings of complex social phenomena. This paper presents three case studies drawn from the authors' research on HIV risk amongst injection drug users in which mixed methods studies yielded apparently discrepant results. We use these case studies (involving injection drug users [IDUs] using a Needle/Syringe Exchange Program in Los Angeles, CA, USA; IDUs seeking to purchase needle/syringes at pharmacies in Tijuana, Mexico; and young street-based IDUs in San Francisco, CA, USA) to identify challenges associated with integrating findings from mixed methods projects, summarize lessons learned, and make recommendations for how to more successfully anticipate and manage the integration of findings. Despite the challenges inherent in reconciling apparently conflicting findings from qualitative and quantitative approaches, in keeping with others who have argued in favour of integrating mixed methods findings, we contend that such an undertaking has the potential to yield benefits that emerge only through the struggle to reconcile discrepant results and may provide a sum that is greater than the individual qualitative and quantitative parts.

  9. Correlation of centroid-based breast size, surface-based breast volume, and asymmetry-score-based breast symmetry in three-dimensional breast shape analysis

    Directory of Open Access Journals (Sweden)

    Henseler, Helga

    2016-06-01

    Full Text Available Objective: The aim of this study was to investigate correlations among the size, volume, and symmetry of the female breast after reconstruction based on previously published data. Methods: The centroid, namely the geometric center of a three-dimensional (3D breast-landmark-based configuration, was used to calculate the size of the breast. The surface data of the 3D breast images were used to measure the volume. Breast symmetry was assessed by the Procrustes analysis method, which is based on the 3D coordinates of the breast landmarks to produce an asymmetry score. The relationship among the three measurements was investigated. For this purpose, the data of 44 patients who underwent unilateral breast reconstruction with an extended latissimus dorsi flap were analyzed. The breast was captured by a validated 3D imaging system using multiple cameras. Four landmarks on each breast and two landmarks marking the midline were used.Results: There was a significant positive correlation between the centroid-based breast size of the unreconstructed breast and the measured asymmetry (p=0.024; correlation coefficient, 0.34. There was also a significant relationship between the surface-based breast volume of the unaffected side and the overall asymmetry score (p<0.001; correlation coefficient, 0.556. An increase in size and especially in volume of the unreconstructed breast correlated positively with an increase in breast asymmetry in a linear relationship.Conclusions: In breast shape analysis, the use of more detailed surface-based data should be preferred to centroid-based size data. As the breast size increases, the latissimus dorsi flap for unilateral breast reconstruction increasingly falls short in terms of matching the healthy breast in a linear relationship. Other reconstructive options should be considered for larger breasts. Generally plastic surgeons should view the two breasts as a single unit when assessing breast aesthetics and not view each

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

    Institute of Scientific and Technical Information of China (English)

    BAICheng-Lin; GUOJun; ZHAOHong

    2005-01-01

    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 tanhfunction method [Phys. Left. A 277 (2000) 212] and the modified extended tanh-function method [Phys. Left. 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.

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

    Institute of Scientific and Technical Information of China (English)

    BAI Cheng-Lin; GUO Jun; ZHAO Hong

    2005-01-01

    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 tanhfunction 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.

  12. Transport coefficients of normal liquid helium-4 calculated by path integral centroid molecular dynamics simulation

    Science.gov (United States)

    Imaoka, Haruna; Kinugawa, Kenichi

    2017-03-01

    Thermal conductivity, shear viscosity, and bulk viscosity of normal liquid 4He at 1.7-4.0 K are calculated using path integral centroid molecular dynamics (CMD) simulations. The calculated thermal conductivity and shear viscosity above lambda transition temperature are on the same order of magnitude as experimental values, while the agreement of shear viscosity is better. Above 2.3 K the CMD well reproduces the temperature dependences of isochoric shear viscosity and of the time integral of the energy current and off-diagonal stress tensor correlation functions. The calculated bulk viscosity, not known in experiments, is several times larger than shear viscosity.

  13. A Derivative-Free Method of Eighth-Order For Finding Simple Root of Nonlinear Equations

    Directory of Open Access Journals (Sweden)

    Neha Choubey

    2015-06-01

    Full Text Available In this paper we have constructed an optimal eighth-order method with four function evaluations to solve the non-linear equations. The proposed method is a three-step method in which no derivative is required. Our scheme is optimal in the sense of Kung and Traub. Moreover, some test functions have been also included to confirm the superiority of the proposed method. At the end, we have presented the basins of attraction of some existing methods along with our proposed method to illustrate their performances.

  14. A computer method of finding valuations forcing validity of LC formulae

    Science.gov (United States)

    Godlewski, Łukasz; Świetorzecka, Kordula; Mulawka, Jan

    2014-11-01

    The purpose of this paper is to present the computer implementation of a system known as LC temporal logic [1]. Firstly, to become familiar with some theoretical issues, a short introduction to this logic is discussed. The algorithms allowing a deep analysis of the formulae of LC logic are considered. In particular we discuss how to determine if a formula is a tautology, contrtautology or it is satisfable. Next, we show how to find all valuations to satisfy the formula. Finally, we consider finding histories generated by the formula and transforming these histories into the state machine. Moreover, a description of the experiments that verify the implementation are briefly presented.

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

    Science.gov (United States)

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

    2014-02-01

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

  16. Alternate Methods for Assuring Credibility of Research and Evaluation Findings in Project Evaluation.

    Science.gov (United States)

    Denton, William T.; Murray, Wayne R.

    This paper describes six existing evaluator-auditor working formats and the conditions which foster credibility of evaluation findings. Evaluators were classified as: (1) member of project developmental team, accountable to project director; (2) independent internal evaluator, accountable to system in general but not to project directors, and (3)…

  17. A Review on Hot-IP Finding Methods and Its Application in Early DDoS Target Detection

    OpenAIRE

    Xuan Dau Hoang; Hong Ky Pham

    2016-01-01

    On the high-speed connections of the Internet or computer networks, the IP (Internet Protocol) packet traffic passing through the network is extremely high, and that makes it difficult for network monitoring and attack detection applications. This paper reviews methods to find the high-occurrence-frequency elements in the data stream and applies the most efficient methods to find Hot-IPs that are high-frequency IP addresses of IP packets passing through the network. Fast finding of Hot-IPs in...

  18. A General Class of Derivative Free Optimal Root Finding Methods Based on Rational Interpolation

    Directory of Open Access Journals (Sweden)

    Fiza Zafar

    2015-01-01

    Full Text Available We construct a new general class of derivative free n-point iterative methods of optimal order of convergence 2n-1 using rational interpolant. The special cases of this class are obtained. These methods do not need Newton’s iterate in the …first step of their iterative schemes. Numerical computations are presented to show that the new methods are efficient and can be seen as better alternates.

  19. Target Centroid Position Estimation of Phase-Path Volume Kalman Filtering

    Directory of Open Access Journals (Sweden)

    Fengjun Hu

    2016-01-01

    Full Text Available For the problem of easily losing track target when obstacles appear in intelligent robot target tracking, this paper proposes a target tracking algorithm integrating reduced dimension optimal Kalman filtering algorithm based on phase-path volume integral with Camshift algorithm. After analyzing the defects of Camshift algorithm, compare the performance with the SIFT algorithm and Mean Shift algorithm, and Kalman filtering algorithm is used for fusion optimization aiming at the defects. Then aiming at the increasing amount of calculation in integrated algorithm, reduce dimension with the phase-path volume integral instead of the Gaussian integral in Kalman algorithm and reduce the number of sampling points in the filtering process without influencing the operational precision of the original algorithm. Finally set the target centroid position from the Camshift algorithm iteration as the observation value of the improved Kalman filtering algorithm to fix predictive value; thus to make optimal estimation of target centroid position and keep the target tracking so that the robot can understand the environmental scene and react in time correctly according to the changes. The experiments show that the improved algorithm proposed in this paper shows good performance in target tracking with obstructions and reduces the computational complexity of the algorithm through the dimension reduction.

  20. Centroid stabilization in alignment of FOA corner cube: designing of a matched filter

    Science.gov (United States)

    Awwal, Abdul; Wilhelmsen, Karl; Roberts, Randy; Leach, Richard; Miller Kamm, Victoria; Ngo, Tony; Lowe-Webb, Roger

    2015-02-01

    The current automation of image-based alignment of NIF high energy laser beams is providing the capability of executing multiple target shots per day. An important aspect of performing multiple shots in a day is to reduce additional time spent aligning specific beams due to perturbations in those beam images. One such alignment is beam centration through the second and third harmonic generating crystals in the final optics assembly (FOA), which employs two retro-reflecting corner cubes to represent the beam center. The FOA houses the frequency conversion crystals for third harmonic generation as the beams enters the target chamber. Beam-to-beam variations and systematic beam changes over time in the FOA corner-cube images can lead to a reduction in accuracy as well as increased convergence durations for the template based centroid detector. This work presents a systematic approach of maintaining FOA corner cube centroid templates so that stable position estimation is applied thereby leading to fast convergence of alignment control loops. In the matched filtering approach, a template is designed based on most recent images taken in the last 60 days. The results show that new filter reduces the divergence of the position estimation of FOA images.

  1. 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.

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

    DEFF Research Database (Denmark)

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

    2007-01-01

    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...

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

    Indian Academy of Sciences (India)

    Wenjun Liu; Kewang Chen

    2013-09-01

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

  4. Finding the Place of Everyday Beauty: Correspondence as a Method of Data Collection

    Directory of Open Access Journals (Sweden)

    Pauliina Rautio

    2009-06-01

    Full Text Available Researching aesthetic engaging with one's surroundings in everyday life led the author to use correspondence as a method of data collection. In this paper she presents her research design and discusses correspondence as an underused method. She introduces the concepts of invisibility, time, and tangibility in defining correspondence as a method. The topic of the correspondence in her research was beauty. In common use beautiful signals that which is desirable. As an evaluative and a future-oriented statement everyday beauty seems to have a place in steering our lives. The participants accounted as beautiful the different meaningful relations they had formed over time to their surroundings. These relations were in constant change as the participants themselves changed over time. The author argues that correspondence is a method that works well in cumulating data for research. It has also proven to be a rewarding method for the participants.

  5. A New Method for Finding Point Sources in High-energy Neutrino Data

    CERN Document Server

    Fang, Ke

    2016-01-01

    The IceCube collaboration has reported the first detection of high-energy astrophysical neutrinos including $\\sim 50$ high-energy starting events, but no individual sources have been identified. It is therefore important to develop the most sensitive and efficient possible algorithms to identify point sources of these neutrinos. The most popular current method works by exploring a dense grid of possible directions to individual sources, and identifying the single direction with the maximum probability of having produced multiple detected neutrinos. This method has numerous strengths, but it is computationally intensive and, because it focuses on the single best location for a point source, additional point sources are not included in the evidence. We propose a new maximum likelihood method that uses the angular separations between all pairs of neutrinos in the data. Unlike existing autocorrelation methods for this type of analysis, which also use angular separations between neutrino pairs, our method incorpor...

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

    Directory of Open Access Journals (Sweden)

    Kohei Arai

    2013-02-01

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

  7. Finding all real roots of a polynomial by matrix algebra and the Adomian decomposition method

    Directory of Open Access Journals (Sweden)

    Hooman Fatoorehchi

    2014-10-01

    Full Text Available In this paper, we put forth a combined method for calculation of all real zeroes of a polynomial equation through the Adomian decomposition method equipped with a number of developed theorems from matrix algebra. These auxiliary theorems are associated with eigenvalues of matrices and enable convergence of the Adomian decomposition method toward different real roots of the target polynomial equation. To further improve the computational speed of our technique, a nonlinear convergence accelerator known as the Shanks transform has optionally been employed. For the sake of illustration, a number of numerical examples are given.

  8. Proposing Cluster_Similarity Method in Order to Find as Much Better Similarities in Databases

    CERN Document Server

    Feizi-Derakhshi, Mohammad-Reza

    2011-01-01

    Different ways of entering data into databases result in duplicate records that cause increasing of databases' size. This is a fact that we cannot ignore it easily. There are several methods that are used for this purpose. In this paper, we have tried to increase the accuracy of operations by using cluster similarity instead of direct similarity of fields. So that clustering is done on fields of database and according to accomplished clustering on fields, similarity degree of records is obtained. In this method by using present information in database, more logical similarity is obtained for deficient information that in general, the method of cluster similarity could improve operations 24% compared with previous methods.

  9. An alternative computational method for finding the minimum-premium insurance portfolio

    Science.gov (United States)

    Katsikis, Vasilios N.

    2016-06-01

    In this article, we design a computational method, which differs from the standard linear programming techniques, for computing the minimum-premium insurance portfolio. The corresponding algorithm as well as a Matlab implementation are provided.

  10. Initial periodontal screening and radiographic findings - A comparison of two methods to evaluate the periodontal situation

    OpenAIRE

    Hornecker Else; Rinke Sven; Szabadi Ivette; Ziebolz Dirk; Mausberg Rainer F

    2011-01-01

    Abstract Background The periodontal screening index (PSI) is an element of the initial dental examination. The PSI provides information on the periodontal situation and allows a first estimation of the treatment required. The dental panoramic tomography (DPT) indicates the proximal bone loss, thus also allowing conclusions on the periodontal situation. In this study, the results of both methods in determining the periodontal situation are compared. Methods The clinical examination covered DMF...

  11. 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.

  12. 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.

  13. Hybrid of Natural Element Method (NEM with Genetic Algorithm (GA to find critical slip surface

    Directory of Open Access Journals (Sweden)

    Shahriar Shahrokhabadi

    2014-06-01

    Full Text Available One of the most important issues in geotechnical engineering is the slope stability analysis for determination of the factor of safety and the probable slip surface. Finite Element Method (FEM is well suited for numerical study of advanced geotechnical problems. However, mesh requirements of FEM creates some difficulties for solution processing in certain problems. Recently, motivated by these limitations, several new Meshfree methods such as Natural Element Method (NEM have been used to analyze engineering problems. This paper presents advantages of using NEM in 2D slope stability analysis and Genetic Algorithm (GA optimization to determine the probable slip surface and the related factor of safety. The stress field is produced under plane strain condition using natural element formulation to simulate material behavior analysis utilized in conjunction with a conventional limit equilibrium method. In order to justify the preciseness and convergence of the proposed method, two kinds of examples, homogenous and non-homogenous, are conducted and results are compared with FEM and conventional limit equilibrium methods. The results show the robustness of the NEM in slope stability analysis.

  14. A New Method for Finding Optical Aberrations on the Basis of Analysis of the Object Hologram Without Additional Measurements

    Science.gov (United States)

    Matkivsky, V. A.; Moiseev, A. A.; Shilyagin, P. A.; Shabanov, D. V.; Gelikonov, G. V.; Gelikonov, V. M.

    2016-11-01

    We propose a new method of compensating for the wavefront aberrations during the image processing. The method employs the digital-holography potential. The developed algorithms allow one to find the wavefront distortions caused by the optical-path nonuniformities during the interference recording of images without additional measurements (i.e., without using the reference point source and measuring the wavefront distortions). The possibility of decreasing the wavefront aberrations from tens to several radians using digital methods is demonstrated.

  15. Efficient Path Finding with the Sweep-Line Method using External Storage

    DEFF Research Database (Denmark)

    Kristensen, Lars Michael; Mailund, Thomas

    2003-01-01

    space exploration and gives the same reduction in peak memory usage as the stand-alone sweep-line method. We evaluate the proposed technique on a number of example systems, and compare its performance to a related technique. These practical experiments demonstrate how the suggested technique complements......The sweep-line method deletes states on-the-fly during state space exploration to reduce peak memory usage. This deletion of states prohibits the immediate generation of, e.g., an error-trace when the violation of a safety property is detected. We address this problem by combining the sweep......-line method with storing a spanning tree of the explored state space in external storage on a magnetic disk. We show how this allows us to easily obtain paths in the state space, such as error-traces. A key property of the proposed technique is that it avoids searching in external storage during the state...

  16. 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.

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

    DEFF Research Database (Denmark)

    Ra, Koy; Pichdara, Lonn; Dararath, Yem

    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 ......). 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.......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...

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

    Science.gov (United States)

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

    2008-01-01

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

  19. Finding common ground in team-based qualitative research using the convergent interviewing method.

    Science.gov (United States)

    Driedger, S Michelle; Gallois, Cindy; Sanders, Carrie B; Santesso, Nancy

    2006-10-01

    Research councils, agencies, and researchers recognize the benefits of team-based health research. However, researchers involved in large-scale team-based research projects face multiple challenges as they seek to identify epistemological and ontological common ground. Typically, these challenges occur between quantitative and qualitative researchers but can occur between qualitative researchers, particularly when the project involves multiple disciplinary perspectives. The authors use the convergent interviewing technique in their multidisciplinary research project to overcome these challenges. This technique assists them in developing common epistemological and ontological ground while enabling swift and detailed data collection and analysis. Although convergent interviewing is a relatively new method described primarily in marketing research, it compares and contrasts well with grounded theory and other techniques. The authors argue that this process provides a rigorous method to structure and refine research projects and requires researchers to identify and be accountable for developing a common epistemological and ontological position.

  20. Analysis of search-extension method for finding multiple solutions of nonlinear problem

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    For numerical computations of multiple solutions of the nonlinear elliptic problemΔu+ f(u)=0 inΩ, u=0 onΓ, a search-extension method (SEM) was proposed and systematically studied by the authors. This paper shall complete its theoretical analysis. It is assumed that the nonlinearity is non-convex and its solution is isolated, under some conditions the corresponding linearized problem has a unique solution. By use of the compactness of the solution family and the contradiction argument, in general conditions, the high order regularity of the solution u∈H1+α,α>0 is proved. Assume that some initial value searched by suitably many eigenbases is already fallen into the neighborhood of the isolated solution, then the optimal error estimates of its nonlinear finite element approximation are shown by the duality argument and continuation method.

  1. Meta-Analysis of the Impact of Research Methods on Findings of First-Mover Advantage

    OpenAIRE

    Pieter A. VanderWerf; John F. Mahon

    1997-01-01

    A long-standing hypothesis is that firms that enter a market early ("first movers") tend to have higher performance than their followers ("first-mover advantage"). Recently, researchers have begun to argue that the statistical tests that support this relationship are limited in their applicability. That is, it is suggested that because of the methods used, these tests show the relationship only for certain subsets of firms, markets, and types of performance. We performed a meta-analysis to de...

  2. A Hybrid Method for Opinion Finding Task (KUNLP at TREC 2008 Blog Track)

    Science.gov (United States)

    2008-11-01

    deployed this idea by using Clusty search en- gine2. Clusty is a text clustering search engine al- lows grouping search results into folder topics. Em...pirically, we issue an original query to Clusty and take the titles of top n clusters3 as expanded terms. Pseudo-relevance feedback: The intuition of...contain terms which are highly related to the topic. For simply examining this method, we se- 2http://clusty.com 3In Clusty , clusters are sorted by

  3. Lead finding from whole plant of Marrubium vulgare L. with Hepatoprotective Potentials through in silico methods

    Institute of Scientific and Technical Information of China (English)

    Amita Verma; Mubashir Masoodi; Bahar Ahmed

    2012-01-01

    Objective: In the present study an attempt has been made to study the antihepatotoxic activity of active compounds in this plant through in silico methods. Methods: We have taken 12 compounds form this plant. All the compounds were further subjected to molecular propertied prediction and drug likeness by Molinspiration and found in compliance with Lipinski’s rule of five. Biochemical parameters like SGOT and SGPT were determined by Reitman and Frankel, ALP by Kind and King, TP by reported methods of Wooton. Results: All the compounds were showed expected similar bioactivity especially in case of enzyme inhibition. Compound Vulgarin showed no violation with good drug likeness score and biological activity as compare to standard drug Silibinin. Vulgarin exhibited a significant antihepatotoxic activity by reducing the elevated levels of serum enzymes such as serum glutamate oxaloacetate transaminase (SGOT) serum glutamate pyruvate oxaloacetate transaminase (SGPT) and alkaline phosphatase (ALP) while the total protein (TP) levels were increased when compared with standard drug silymarin against CCl4-induced toxicity in Wistar rats. These biochemical observations were also supplemented by histopathological examinations of the liver sections. Conclusions: We found that Vulgarin one of the twelve compounds is showed better drug likeness and biological activity against Silibinin. So this particular compound can be taken as lead compound for further drug discovery for hepatotoxic activity.

  4. A method for finding the optimal predictor indices for local wave climate conditions

    Science.gov (United States)

    Camus, Paula; Méndez, Fernando J.; Losada, Inigo J.; Menéndez, Melisa; Espejo, Antonio; Pérez, Jorge; Rueda, Ana; Guanche, Yanira

    2014-07-01

    In this study, a method to obtain local wave predictor indices that take into account the wave generation process is described and applied to several locations. The method is based on a statistical model that relates significant wave height with an atmospheric predictor, defined by sea level pressure fields. The predictor is composed of a local and a regional part, representing the sea and the swell wave components, respectively. The spatial domain of the predictor is determined using the Evaluation of Source and Travel-time of wave Energy reaching a Local Area (ESTELA) method. The regional component of the predictor includes the recent historical atmospheric conditions responsible for the swell wave component at the target point. The regional predictor component has a historical temporal coverage ( n-days) different to the local predictor component (daily coverage). Principal component analysis is applied to the daily predictor in order to detect the dominant variability patterns and their temporal coefficients. Multivariate regression model, fitted at daily scale for different n-days of the regional predictor, determines the optimum historical coverage. The monthly wave predictor indices are selected applying a regression model using the monthly values of the principal components of the daily predictor, with the optimum temporal coverage for the regional predictor. The daily predictor can be used in wave climate projections, while the monthly predictor can help to understand wave climate variability or long-term coastal morphodynamic anomalies.

  5. Adaptive Ant Colony Clustering Method Applied to Finding Closely Communicating Community

    Directory of Open Access Journals (Sweden)

    Yan Liu

    2012-02-01

    Full Text Available The investigation of community structures in networks is an important issue in many domains and disciplines. Closely communicating community is different from the traditional community which emphasize particularly on structure or context. Our previous method played more emphasis on the feasibility that ant colony algorithm applied to community detection. However the essence of closely communicating community did not be described clearly. In this paper, the definition of closely communicating community is put forward firstly, the four features are described and corresponding methods are introduced to achieve the value of features between each pair. Meanwhile, pair propinquity and local propinquity are put forward and used to guide ants’ decision. Based on the previous work, the closely communicating community detection method is improved in four aspects of adaptive adjusting, which are entropy based weight modulation, combining historical paths and random wandering to select next coordination, the strategy of forcing unloading and the adaptive change of ant’s eyesight. The value selection of parameters is discussed in the portion of experiments, and the results also reveal the improvement of our algorithm in adaptive djusting.

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

    Science.gov (United States)

    McMillan, Wendy J

    2009-01-01

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

  7. A Mixed-Methods Approach Examining Illicit Prescription Stimulant Use: Findings From a Northern California University.

    Science.gov (United States)

    Bavarian, Niloofar; McMullen, Jaimie; Flay, Brian R; Kodama, Cathy; Martin, Melissa; Saltz, Robert F

    2017-02-27

    Preventing the illicit use of prescription stimulants, a particularly high-risk form of substance use, requires approaches that utilize theory-guided research. We examined this behavior within the context of a random sample of 554 undergraduate students attending a university in northern California. Approximately 17% of students self-reported engaging in this behavior during college; frequency of misuse per academic term ranged from less than once to 40 or more times. Although most misusers reported oral ingestion, a small proportion reported snorting and smoking the drug. The majority of misusers reported receiving the drug at no cost, and the primary source of the drug was friends. Misusers were motivated by both academic (e.g., to improve focus) and non-academic (e.g., to experiment) reasons. Our thematic analyses of an open-end question revealed that students abstaining from illicit use of prescription stimulants did so primarily for reasons related to health risks, ethics, and adherence regulations. Results from adjusted logistic regression analyses showed that correlates of the behavior were intrapersonal, interpersonal, and environmental in nature. We conclude that characteristics of misuse are a cause for concern, and correlates of the behavior are multifaceted. These findings, in addition to insights provided by students who choose not to engage in this behavior, suggest that a number of prevention approaches are plausible, such as a social norms campaign that simultaneously corrects exaggerated beliefs about prevalence while also illustrating why abstainers, in their own words, choose to abstain.

  8. A method to find longevity-selected positions in the mammalian proteome.

    Directory of Open Access Journals (Sweden)

    Jeremy Semeiks

    Full Text Available Evolutionary theory suggests that the force of natural selection decreases with age. To explore the extent to which this prediction directly affects protein structure and function, we used multiple regression to find longevity-selected positions, defined as the columns of a sequence alignment conserved in long-lived but not short-lived mammal species. We analyzed 7,590 orthologous protein families in 33 mammalian species, accounting for body mass, phylogeny, and species-specific mutation rate. Overall, we found that the number of longevity-selected positions in the mammalian proteome is much higher than would be expected by chance. Further, these positions are enriched in domains of several proteins that interact with one another in inflammation and other aging-related processes, as well as in organismal development. We present as an example the kinase domain of anti-müllerian hormone type-2 receptor (AMHR2. AMHR2 inhibits ovarian follicle recruitment and growth, and a homology model of the kinase domain shows that its longevity-selected positions cluster near a SNP associated with delayed human menopause. Distinct from its canonical role in development, this region of AMHR2 may function to regulate the protein's activity in a lifespan-specific manner.

  9. A New Method of Fractional Dynamics, i.e., Fractional Mei Symmetrical Method for Finding Conserved Quantity, and its Applications to Physics

    Science.gov (United States)

    Luo, Shao-Kai; Dai, Yun; Zhang, Xiao-Tian; He, Jin-Man

    2016-10-01

    In this paper, we present the fractional Mei symmetrical method of finding conserved quantity and explore its applications to physics. For the fractional generalized Hamiltonian system, we introduce the fractional infinitesimal transformation of Lie groups and, under the transformation, give the fractional Mei symmetrical definition, criterion and determining equation. Then, we present the fractional Mei symmetrical theorem of finding conserved quantity. As the fractional Mei symmetrical method's applications, we respectively find the conserved quantities of a fractional general relativistic Buchduhl model, a fractional three-body model and a fractional Robbins-Lorenz model.

  10. 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.

  11. Energy Centroids of Spin $I$ States by Random Two-body Interactions

    CERN Document Server

    Zhao, Y M; Ogawa, K

    2005-01-01

    In this paper we study the behavior of energy centroids (denoted as $\\bar{E_I}$) of spin $I$ states in the presence of random two-body interactions, for systems ranging from very simple systems (e.g. single-$j$ shell for very small $j$) to very complicated systems (e.g., many-$j$ shells with different parities and with isospin degree of freedom). Regularities of $\\bar{E_I}$'s discussed in terms of the so-called geometric chaoticity (or quasi-randomness of two-body coefficients of fractional parentage) in earlier works are found to hold even for very simple systems in which one cannot assume the geometric chaoticity. It is shown that the inclusion of isospin and parity does not "break" the regularities of $\\bar{E_I}$'s.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    1998-10-01

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

  13. Path integral centroid molecular dynamics simulation of para-hydrogen sandwiched by graphene sheets

    Science.gov (United States)

    Minamino, Yuki; Kinugawa, Kenichi

    2016-11-01

    The carbon-hydrogen composite systems of para-hydrogen (p-H2) sandwiched by a couple of graphene sheets have been investigated by means of path integral centroid molecular dynamics simulations at 17 K. It has been shown that sandwiched hydrogen is liquid-like but p-H2 molecules are preferably adsorbed onto the graphene sheets because of attractive graphene-hydrogen interaction. The diffusion coefficient of p-H2 molecules in the direction parallel to the graphene sheets is comparable to that in pure liquid p-H2. There exists a characteristic mode of 140 cm-1 of the p-H2 molecules, attributed to adsorption-binding motion perpendicular to the graphene sheets.

  14. Finding the buckling load of non-uniform columns using the iteration perturbation method

    Directory of Open Access Journals (Sweden)

    Aref Afsharfard

    2014-01-01

    Full Text Available The aim of this study is to calculate the critical load of variable inertia columns. The example studied in this paper can be used as a paradigm for other non-uniform columns. The wavelength of equivalent vibratory system is used to calculate the critical load of the trigonometrically varied inertia column. In doing so, the equilibrium equation of the column is theoretically studied using the perturbation method. Accuracy of the calculated results is evaluated by comparing the solution with numerical results. Effect of improving the initial guess on the solution accuracy is investigated. Effects of varying parameters of the trigonometrically varied inertia and the uniformly tapered columns on their stability behavior are studied. Finally, using the so-called “perfectibility” parameter, two design goals, i.e., being lightweight and being strong, are studied for the discussed columns.

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

    Science.gov (United States)

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

    2010-01-01

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

  16. The value of earth observations: methods and findings on the value of Landsat imagery

    Science.gov (United States)

    Miller, Holly; Serbina, Larisa O.; Richardson, Leslie A.; Ryker, Sarah J.; Newman, Timothy R.

    2016-01-01

    Data from Earth observation systems are used extensively in managing and monitoring natural resources, natural hazards, and the impacts of climate change, but the value of such data can be difficult to estimate, particularly when it is available at no cost. Assessing the socioeconomic and scientific value of these data provides a better understanding of the existing and emerging research, science, and applications related to this information and contributes to the decision making process regarding current and future Earth observation systems. Recent USGS research on Landsat data has advanced the literature in this area by using a variety of methods to estimate value. The results of a 2012 survey of Landsat users, a 2013 requirements assessment, and 2013 case studies of applications of Landsat imagery are discussed.

  17. A Proposal to Speed up the Computation of the Centroid of an Interval Type-2 Fuzzy Set

    Directory of Open Access Journals (Sweden)

    Carlos E. Celemin

    2013-01-01

    Full Text Available This paper presents two new algorithms that speed up the centroid computation of an interval type-2 fuzzy set. The algorithms include precomputation of the main operations and initialization based on the concept of uncertainty bounds. Simulations over different kinds of footprints of uncertainty reveal that the new algorithms achieve computation time reductions with respect to the Enhanced-Karnik algorithm, ranging from 40 to 70%. The results suggest that the initialization used in the new algorithms effectively reduces the number of iterations to compute the extreme points of the interval centroid while precomputation reduces the computational cost of each iteration.

  18. A NEW PROOF OF JORDAN'S CENTROID THEOREM%约当重心定理的一个新证明

    Institute of Scientific and Technical Information of China (English)

    Skrun.,R; 李冠英

    1999-01-01

    Jordan's Centroid Theorem (1869) states th at the centroid of a tree consists of either a single vertex or a pair of adjace nt vertices. This paper presents a new proof of this theorem.%约当重心定理(1869年)提出,一棵树的重心不是由一个单一的顶点组成,就是由一对相邻的顶点组成.这篇文章提出了一个证明这个定理的新方法.

  19. Use of a Hybrid Edge Node-Centroid Node Approach to Thermal Modeling

    Science.gov (United States)

    Peabody, Hume L.

    2010-01-01

    A recent proposal submitted for an ESA mission required that models be delivered in ESARAD/ESATAN formats. ThermalDesktop was the preferable analysis code to be used for model development with a conversion done as the final step before delivery. However, due to some differences between the capabilities of the two codes, a unique approach was developed to take advantage of the edge node capability of ThermalDesktop while maintaining the centroid node approach used by ESARAD. In essence, two separate meshes were used: one for conduction and one for radiation. The conduction calculations were eliminated from the radiation surfaces and the capacitance and radiative calculations were eliminated from the conduction surfaces. The resulting conduction surface nodes were coincident with all nodes of the radiation surface and were subsequently merged, while the nodes along the edges remained free. Merging of nodes on the edges of adjacent surfaces provided the conductive links between surfaces. Lastly, all nodes along edges were placed into the subnetwork and the resulting supernetwork included only the nodes associated with radiation surfaces. This approach had both benefits and disadvantages. The use of centroid, surface based radiation reduces the overall size of the radiation network, which is often the most computationally intensive part of the modeling process. Furthermore, using the conduction surfaces and allowing ThermalDesktop to calculate the conduction network can save significant time by not having to manually generate the couplings. Lastly, the resulting GMM/TMM models can be exported to formats which do not support edge nodes. One drawback, however, is the necessity to maintain two sets of surfaces. This requires additional care on the part of the analyst to ensure communication between the conductive and radiative surfaces in the resulting overall network. However, with more frequent use of this technique, the benefits of this approach can far outweigh the

  20. Genome-scale identification method applied to find cryptic aminoglycoside resistance genes in Pseudomonas aeruginosa.

    Directory of Open Access Journals (Sweden)

    Julie M Struble

    Full Text Available BACKGROUND: The ability of bacteria to rapidly evolve resistance to antibiotics is a critical public health problem. Resistance leads to increased disease severity and death rates, as well as imposes pressure towards the discovery and development of new antibiotic therapies. Improving understanding of the evolution and genetic basis of resistance is a fundamental goal in the field of microbiology. RESULTS: We have applied a new genomic method, Scalar Analysis of Library Enrichments (SCALEs, to identify genomic regions that, given increased copy number, may lead to aminoglycoside resistance in Pseudomonas aeruginosa at the genome scale. We report the result of selections on highly representative genomic libraries for three different aminoglycoside antibiotics (amikacin, gentamicin, and tobramycin. At the genome-scale, we show significant (p<0.05 overlap in genes identified for each aminoglycoside evaluated. Among the genomic segments identified, we confirmed increased resistance associated with an increased copy number of several genomic regions, including the ORF of PA5471, recently implicated in MexXY efflux pump related aminoglycoside resistance, PA4943-PA4946 (encoding a probable GTP-binding protein, a predicted host factor I protein, a delta 2-isopentenylpyrophosphate transferase, and DNA mismatch repair protein mutL, PA0960-PA0963 (encoding hypothetical proteins, a probable cold shock protein, a probable DNA-binding stress protein, and aspartyl-tRNA synthetase, a segment of PA4967 (encoding a topoisomerase IV subunit B, as well as a chimeric clone containing two inserts including the ORFs PA0547 and PA2326 (encoding a probable transcriptional regulator and a probable hypothetical protein, respectively. CONCLUSIONS: The studies reported here demonstrate the application of new a genomic method, SCALEs, which can be used to improve understanding of the evolution of antibiotic resistance in P. aeruginosa. In our demonstration studies, we

  1. Preliminary Findings of a Format-based Foreign Language Teaching Method for School Children in the Basque Country.

    Science.gov (United States)

    Azpillaga, Beronika; Arzamendi, Jesus; Etxeberria, Feli; Garagorri, Xabier; Lindsay, Diana; Joaristi, Luis

    2001-01-01

    Describes the preliminary findings in the Basque Country of a project shared by four European countries to teach a second language or a foreign language to preschool and school-age children. The method used to teach the foreign language--English--is based on the use of dramatized formats. Examines level of language proficiency achieved with each…

  2. A Method To Find The Area Of Sector Without The Usage Of Angle Made By The Chord

    OpenAIRE

    Syed Abdul Lateef

    2015-01-01

    ABSTRACT This is the simplest method to find the area of the segment of the circle without the usage of the angle made by the chord and thus the area of sector could be found without the usage of angle made by chord. This is done by relating the area of segment to the area of sector.

  3. A Method To Find The Area Of Sector Without The Usage Of Angle Made By The Chord

    Directory of Open Access Journals (Sweden)

    Syed Abdul Lateef

    2015-02-01

    Full Text Available ABSTRACT This is the simplest method to find the area of the segment of the circle without the usage of the angle made by the chord and thus the area of sector could be found without the usage of angle made by chord. This is done by relating the area of segment to the area of sector.

  4. Atmospheric Deposition: Sampling Procedures, Analytical Methods, and Main Recent Findings from the Scientific Literature

    Directory of Open Access Journals (Sweden)

    M. Amodio

    2014-01-01

    Full Text Available The atmosphere is a carrier on which some natural and anthropogenic organic and inorganic chemicals are transported, and the wet and dry deposition events are the most important processes that remove those chemicals, depositing it on soil and water. A wide variety of different collectors were tested to evaluate site-specificity, seasonality and daily variability of settleable particle concentrations. Deposition fluxes of POPs showed spatial and seasonal variations, diagnostic ratios of PAHs on deposited particles, allowed the discrimination between pyrolytic or petrogenic sources. Congener pattern analysis and bulk deposition fluxes in rural sites confirmed long-range atmospheric transport of PCDDs/Fs. More and more sophisticated and newly designed deposition samplers have being used for characterization of deposited mercury, demonstrating the importance of rain scavenging and the relatively higher magnitude of Hg deposition from Chinese anthropogenic sources. Recently biological monitors demonstrated that PAH concentrations in lichens were comparable with concentrations measured in a conventional active sampler in an outdoor environment. In this review the authors explore the methodological approaches used for the assessment of atmospheric deposition, from the analysis of the sampling methods, the analytical procedures for chemical characterization of pollutants and the main results from the scientific literature.

  5. bcrm: Bayesian Continual Reassessment Method Designs for Phase I Dose-Finding Trials

    Directory of Open Access Journals (Sweden)

    Michael Sweeting

    2013-09-01

    Full Text Available This paper presents the R package bcrm for conducting and assessing Bayesian continual reassessment method (CRM designs in Phase I dose-escalation trials. CRM designsare a class of adaptive design that select the dose to be given to the next recruited patient based on accumulating toxicity data from patients already recruited into the trial, often using Bayesian methodology. Despite the original CRM design being proposed in 1990, the methodology is still not widely implemented within oncology Phase I trials. The aim of this paper is to demonstrate, through example of the bcrm package, how a variety of possible designs can be easily implemented within the R statistical software, and how properties of the designs can be communicated to trial investigators using simple textual and graphical output obtained from the package. This in turn should facilitate an iterative process to allow a design to be chosen that is suitable to the needs of the investigator. Our bcrm package is the first to offer a large comprehensive choice of CRM designs, priors and escalation procedures, which can be easily compared and contrasted within the package through the assessment of operating characteristics.

  6. 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.

  7. [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.

  8. 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.

  9. 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 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.

  10. Analysis of Synthetic Cannabinoids in Botanical Material: A Review of Analytical Methods and Findings.

    Science.gov (United States)

    Presley, B C; Jansen-Varnum, S A; Logan, B K

    2013-03-01

    Synthetic cannabinoid analogs have gained a great deal of attention from the forensic community within the last four years. The compounds found to be of most interest to forensic practitioners include those of the following series: JWH, CP, HU, AM, WIN, RCS, and most recently, XLR and UR. Structurally the HU compounds are most similar in structure to Δ9-tetrahydrocannabinol (THC), the main psychoactive component of marijuana. The novel compounds include cyclohexylphenols, naphthoylindoles, naphthylmethylindoles, naphthylmethylindenes, benzoylindoles, naphthoylpyrroles, phenylacetylindoles, adamantoylindoles, and tetramethylcyclopropylindoles. Many of these compounds are cannabinoid receptor agonists and were originally synthesized for medical research purposes but have recently been appropriated into the illicit drug market. Their psychoactive effects, mimicking those of marijuana, as well as their indeterminate legal status, have made them popular for recreational use. Solutions of the compounds dissolved in organic solvents are sprayed onto botanical material and sold as "herbal incense" products via the Internet, and in smoke shops, convenience stores, and gas stations around the world. Many of the products are labeled "Not for human consumption" in an attempt to circumvent legislation that bans the sale and manufacture of certain compounds and their analogs for human use. The compounds that were first detected following forensic analysis of botanical materials included JWH-018, JWH-073, and CP 47,497 (C7 and C8 homologs). However, in the four years since their appearance the number of compounds has grown, and additional diverse classes of compounds have been detected. Governments worldwide have taken action in an attempt to control those compounds that have become widespread in their regions. This article discusses the history of synthetic cannabinoids and how they have been detected in the illicit drug market. It also discusses the analytical methods and

  11. A Review on Hot-IP Finding Methods and Its Application in Early DDoS Target Detection

    Directory of Open Access Journals (Sweden)

    Xuan Dau Hoang

    2016-10-01

    Full Text Available On the high-speed connections of the Internet or computer networks, the IP (Internet Protocol packet traffic passing through the network is extremely high, and that makes it difficult for network monitoring and attack detection applications. This paper reviews methods to find the high-occurrence-frequency elements in the data stream and applies the most efficient methods to find Hot-IPs that are high-frequency IP addresses of IP packets passing through the network. Fast finding of Hot-IPs in the IP packet stream can be effectively used in early detection of DDoS (Distributed Denial of Service attack targets and spreading sources of network worms. Research results show that the Count-Min method gives the best overall performance for Hot-IP detection thanks to its low computational complexity, low space requirement and fast processing speed. We also propose an early detection model of DDoS attack targets based on Hot-IP finding, which can be deployed on the target network routers.

  12. 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.

  13. Digital animation as a method to disseminate research findings to the community using a community-based participatory approach.

    Science.gov (United States)

    Vaughn, Nicole A; Jacoby, Sara F; Williams, Thalia; Guerra, Terry; Thomas, Nicole A; Richmond, Therese S

    2013-03-01

    Community-based participatory research (CBPR) has garnered increasing interest over the previous two decades as researchers have tackled increasingly complex health problems. In academia, professional presentations and articles are major ways that research is disseminated. However, dissemination of research findings to the people and communities who participated in the research is many times forgotten. In addition, little scholarly literature is focused on creative dissemination of research findings to the community using CBPR methods. We seek to fill this gap in the literature by providing an exemplar of research dissemination and partnership strategies that were used to complete this project. In this paper, we present a novel approach to the dissemination of research findings to our targeted communities through digital animation. We also provide the foundational thinking and specific steps that were taken to select this specific dissemination product development and distribution strategy.

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

    Science.gov (United States)

    Khan, Muhammad Jibran; Mahmood, Waqas

    2015-12-01

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

  15. Summary Findings from the AVT-191 Project to Assess Sensitivity Analysis and Uncertainty Quantification Methods for Military Vehicle Design

    Science.gov (United States)

    Benek, John A.; Luckring, James M.

    2017-01-01

    A NATO symposium held in Greece in 2008 identified many promising sensitivity analysis and uncertainty quantification technologies, but the maturity and suitability of these methods for realistic applications was not clear. The NATO Science and Technology Organization, Task Group AVT-191 was established to evaluate the maturity and suitability of various sensitivity analysis and uncertainty quantification methods for application to realistic vehicle development problems. The program ran from 2011 to 2015, and the work was organized into four discipline-centric teams: external aerodynamics, internal aerodynamics, aeroelasticity, and hydrodynamics. This paper summarizes findings and lessons learned from the task group.

  16. SEQUENTIAL AND PARALLEL ALGORITHM TO FIND MAXIMUM FLOW ON EXTENDED MIXED NETWORKS BY REVISED POSTFLOW-PULL METHODS

    Directory of Open Access Journals (Sweden)

    Lau Nguyen Dinh

    2016-01-01

    Full Text Available The problem of finding maximum flow in network graph is extremely interesting and practically applicable in many fields in our daily life, especially in transportation. Therefore, a lot of researchers have been studying this problem in various methods. Especially in 2013, we has developed a new algorithm namely, postflow-pull algorithm to find the maximum flow on traditional networks. In this paper, we revised postflow-push methods to solve this problem of finding maximum flow on extended mixed network. In addition, to take more advantage of multi-core architecture of the parallel computing system, we build this parallel algorithm. This is a completely new method not being announced in the world. The results of this paper are basically systematized and proven. The idea of this algorithm is using multi processors to work in parallel by postflow_push algorithm. Among these processors, there is one main processor managing data, sending data to the sub processors, receiving data from the sub-processors. The sub-processors simultaneously execute their work and send their data to the main processor until the job is finished, the main processor will show the results of the problem.

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

    Directory of Open Access Journals (Sweden)

    Carsten Gottschlich

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

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

    Science.gov (United States)

    Gottschlich, Carsten; Schuhmacher, Dominic

    2014-01-01

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

  19. 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.

  20. New Distributed Positioning Algorithm Based on Centroid of Circular Belt for Wireless Sensor Networks

    Institute of Scientific and Technical Information of China (English)

    Xu-Zhi Lai; Simon X. Yang; Gui-Xiu Zeng; Jin-Hua She; Min Wu

    2007-01-01

    This paper presents a new distributed positioning algorithm for unknown nodes in a wireless sensor network. The algorithm is based exclusively on connectivity. First, assuming that the positions of the anchor nodes are already known, a circular belt containing an unknown node is obtained using information about the anchor nodes that are in radio range of the unknown node, based on the geometric relationships and communication constraints among the unknown node and the anchor nodes. Then, the centroid of the circular belt is taken to be the estimated position of the unknown node. Since the algorithm is very simple and since the only communication needed is between the anchor nodes and the unknown node, the communication and computational loads are very small. Furthermore, the algorithm is robust because neither the failure of old unknown nodes nor the addition of new unknown nodes influences the positioning of unknown nodes to be located. A theoretical analysis and simulation results show that the algorithm does not produce any cumulative error and is insensitive to range error, and that a change in the number of sensor nodes does not affect the communication or computational load. These features make this algorithm suitable for all sizes of low-power wireless sensor networks.

  1. Centroid neural network with a divergence measure for GPDF data clustering.

    Science.gov (United States)

    Park, Dong-Chul; Kwon, Oh-Hyun; Chung, Jio

    2008-06-01

    An unsupervised competitive neural network for efficient clustering of Gaussian probability density function (GPDF) data of continuous density hidden Markov models (CDHMMs) is proposed in this paper. The proposed unsupervised competitive neural network, called the divergence-based centroid neural network (DCNN), employs the divergence measure as its distance measure and utilizes the statistical characteristics of observation densities in the HMM for speech recognition problems. While the conventional clustering algorithms used for the vector quantization (VQ) codebook design utilize only the mean values of the observation densities in the HMM, the proposed DCNN utilizes both the mean and the covariance values. When compared with other conventional unsupervised neural networks, the DCNN successfully allocates more code vectors to the regions where GPDF data are densely distributed while it allocates fewer code vectors to the regions where GPDF data are sparsely distributed. When applied to Korean monophone recognition problems as a tool to reduce the size of the codebook, the DCNN reduced the number of GPDFs used for code vectors by 65.3% while preserving recognition accuracy. Experimental results with a divergence-based k-means algorithm and a divergence-based self-organizing map algorithm are also presented in this paper for a performance comparison.

  2. Transport properties of liquid para-hydrogen: The path integral centroid molecular dynamics approach

    Science.gov (United States)

    Yonetani, Yoshiteru; Kinugawa, Kenichi

    2003-11-01

    Several fundamental transport properties of a quantum liquid para-hydrogen (p-H2) at 17 K have been numerically evaluated by means of the quantum dynamics simulation called the path integral centroid molecular dynamics (CMD). For comparison, classical molecular dynamics (MD) simulations have also been performed under the same condition. In accordance with the previous path integral simulations, the calculated static properties of the liquid agree well with the experimental results. For the diffusion coefficient, thermal conductivity, and shear viscosity, the CMD predicts the values closer to the experimental ones though the classical MD results are far from the reality. The agreement of the CMD result with the experimental one is especially good for the shear viscosity with the difference less than 5%. The calculated diffusion coefficient and the thermal conductivity agree with the experimental values at least in the same order. We predict that the ratio of bulk viscosity to shear viscosity for liquid p-H2 is much larger than classical van der Waals simple liquids such as rare gas liquids.

  3. Gene expression centroids that link with low intrinsic aerobic exercise capacity and complex disease risk.

    Science.gov (United States)

    Kivelä, Riikka; Silvennoinen, Mika; Lehti, Maarit; Rinnankoski-Tuikka, Rita; Purhonen, Tatja; Ketola, Tarmo; Pullinen, Katri; Vuento, Meri; Mutanen, Niina; Sartor, Maureen A; Reunanen, Hilkka; Koch, Lauren G; Britton, Steven L; Kainulainen, Heikki

    2010-11-01

    A strong link exists between low aerobic exercise capacity and complex metabolic diseases. To probe this linkage, we utilized rat models of low and high intrinsic aerobic endurance running capacity that differ also in the risk for metabolic syndrome. We investigated in skeletal muscle gene-phenotype relationships that connect aerobic endurance capacity with metabolic disease risk factors. The study compared 12 high capacity runners (HCRs) and 12 low capacity runners (LCRs) from generation 18 of selection that differed by 615% for maximal treadmill endurance running capacity. On average, LCRs were heavier and had increased blood glucose, insulin, and triglycerides compared with HCRs. HCRs were higher for resting metabolic rate, voluntary activity, serum high density lipoproteins, muscle capillarity, and mitochondrial area. Bioinformatic analysis of skeletal muscle gene expression data revealed that many genes up-regulated in HCRs were related to oxidative energy metabolism. Seven mean mRNA expression centroids, including oxidative phosphorylation and fatty acid metabolism, correlated significantly with several exercise capacity and disease risk phenotypes. These expression-phenotype correlations, together with diminished skeletal muscle capillarity and mitochondrial area in LCR rats, support the general hypothesis that an inherited intrinsic aerobic capacity can underlie disease risks.

  4. Hybrid Extragradient Methods for Finding Zeros of Accretive Operators and Solving Variational Inequality and Fixed Point Problems in Banach Spaces

    Directory of Open Access Journals (Sweden)

    Lu-Chuan Ceng

    2013-01-01

    Full Text Available We introduce and analyze hybrid implicit and explicit extragradient methods for finding a zero of an accretive operator and solving a general system of variational inequalities and a fixed point problem of an infinite family of nonexpansive self-mappings in a uniformly convex Banach space X which has a uniformly Gateaux differentiable norm. We establish some strong convergence theorems for hybrid implicit and explicit extra-gradient algorithms under suitable assumptions. Furthermore, we derive the strong convergence of hybrid implicit and explicit extragradient algorithms for finding a common element of the set of zeros of an accretive operator and the common fixed point set of an infinite family of nonexpansive self-mappings and a self-mapping whose complement is strictly pseudocontractive and strongly accretive in X. The results presented in this paper improve, extend, supplement, and develop the corresponding results announced in the earlier and very recent literature.

  5. 基于加权聚类质心的 SVM 不平衡分类方法%Support vector machine imbalanced data classification based on weighted clustering centroid

    Institute of Scientific and Technical Information of China (English)

    2013-01-01

    Classification of imbalanced data has become a research hot topic in machine learning .Traditional classi-fication algorithms assume that different classes have balanced distribution or equal misclassification cost , thus, making it hard to get ideal result of classifications .A support vector machine (SVM) classification method based on weighted clustering centroid was proposed in this paper .First, unsupervised clustering was applied to the positive and negative samples respectively to extract the clustering centroid of each clustering , which was represented the most in compactness of the clustering sample .Next, all clustering centroids formed a new set of balance training .In order to minimize the information loss during clustering , each clustering centroid was associated with a weight factor that was defined proportional to the number of samples of the class .Finally, all clustering centroids and weight fac-tors participated in the training of the improved SVM model .Experimental results show that the proposed method can make the sample selected from model train sets more typical and improve the classification performance better than other sampling techniques for dealing with imbalanced data .%  不平衡数据分类是机器学习研究的热点问题,传统分类算法假定不同类别具有平衡分布或误分代价相同,难以得到理想的分类结果。提出一种基于加权聚类质心的SVM分类方法,在正负类样本上分别进行聚类,对每个聚类,用聚类质心和权重因子代表聚类内样本分布和数量,相等类别数量的质心和权重因子参与SVM模型训练。实验结果表明,该方法使模型的训练样本具有较高的代表性,分类性能与其他采样方法相比得到了提升。

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

    Directory of Open Access Journals (Sweden)

    V.V. Kulish

    2015-06-01

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

  7. The Centroid Shifts of Light Beams Reflected from Multi-Layers and the Effects of Angular Momentum Manifestations

    CERN Document Server

    Lusk, Mark T; Quinteiro, Guillermo F

    2016-01-01

    Laguerre-Gaussian (LG) beams reflected from a multi-layered dielectric experience a shift in their centroid that is different than that from a single interface. This has been previously investigated for linearly polarized beams and, to a much lesser extent, beams with spin angular momentum. Here a combination of perturbation and computational analyses is used to provide a unified quantification of these shifts in layered dielectrics with two parallel interfaces. The approach is then extended to consider the qualitatively new behavior that results when the light is endowed with an intrinsic orbital angular momentum--i.e. vortex beams. Destructive interference causes singular lateral shifts in the centroid of the reflected vortex beam for which spin alone produces only a mild modulation. In the case of total internal reflection, both spin and intrinsic orbital angular momentum contribute to an enhancement of these lateral shifts as the interlayer thickness is decreased. This is just the opposite of the trend as...

  8. Low-Frequency Centroid Moment Tensor Inversion of the 2015 Illapel Earthquake from Superconducting-Gravimeter Data

    Science.gov (United States)

    Zábranová, Eliška; Matyska, Ctirad

    2016-04-01

    After the 2015 Illapel earthquake the radial and spheroidal modes up to 1 mHz were registered by the network of superconducting gravimeters. These data provide unique opportunity to obtain ultralow-frequency estimates of several centroid moment tensor components. We employ the superconducting-gravimeter records of 60-h lengths and perform the joint inversion for M_{rr}, (M_{\\vartheta \\vartheta }-M_{\\varphi \\varphi })/2 and M_{\\vartheta \\varphi } centroid moment tensor components from spheroidal modes up to 1 mHz. The M_{rr} component is also obtained from independent inversion of the radial modes _0S_0 and _1S_0. Our results are consistent with the published solutions obtained from higher frequency data, suggesting thus negligible slow afterslip phenomenon.

  9. Characterization of the ASPIICS/OPSE metrology sub-system and PSF centroiding procedure

    Science.gov (United States)

    Loreggia, D.; Fineschi, S.; Capobianco, G.; Bemporad, A.; Focardi, M.; Landini, F.; Massone, G.; Casti, M.; Nicolini, G.; Pancrazi, M.; Romoli, M.; Noce, V.; Baccani, C.; Cernica, I.; Purica, M.; Nisulescu, M.; Thizy, C.; Servaye, J. S.; Renotte, E.

    2016-07-01

    years have raised increasing interest. Many applications of astronomical observation techniques, as coronography and interferometry get great benefit when moved in space and the employment of diluted systems represents a milestone to step-over in astronomical research. In this work, we present the Optical Position Sensors Emitter (OPSE) metrological sub-system on-board of the PROBA3. PROBA3 is an ESA technology mission that will test in-orbit many metrology techniques for the maintenance of a Formation Flying with two satellites, in this case an occulter and a main satellite housing a coronagraph named ASPIICS, kept at an average inter-distance of 144m. The scientific task is the observation of the Sun's Corona at high spatial and temporal resolution down to 1.08R⊙. The OPSE will monitor the relative position of the two satellites and consists of 3 emitters positioned on the rear surface of the occulter, that will be observed by the coronagraph itself. A Centre of Gravity (CoG) algorithm is used to monitor the emitter's PSF at the focal plane of the Coronagraph retrieving the Occulter position with respect to the main spacecraft. The 3σ location target accuracy is 300μm for lateral movement and 21cm for longitudinal movements. A description of the characterization tests on the OPSE LED sources, and of the design for a laboratory set-up for on ground testing is given with a preliminary assessment of the performances expected from the OPSE images centroiding algorithm.

  10. Spurious dianeutral mixing in a global ocean model using spherical centroidal voronoi tessellations

    Science.gov (United States)

    Zhao, Shimei; Liu, Yudi

    2016-12-01

    In order to quantitatively evaluate the spurious dianeutral mixing in a global ocean model MPAS-Ocean (Model for Prediction Across Scales) using a spherical centroidal voronoi tessellations developed jointly by the National Center for Atmospheric Research and the Los Alamos National Laboratory in the United States, we choose z* vertical coordinate system in MPAS-Ocean, in which all physical mixing processes, such as convection adjustment and explicit diffusion parameter schemes, are omitted, using a linear equation of state. By calculating the Reference Potential Energy (RPE), front revolution position, time rate of RPE change, probability density function distribution and dimensionless parameter χ, from the perspectives of resolution, viscosity, Horizontal Grid Reynolds Number (HGRN), ReΔ, and momentum transmission scheme, using two ideal cases, overflow and baroclinic eddy channel, we qualitatively analyze the simulation results by comparison with the three non-isopycnal models in Ilicak et al. (2012), i.e., MITGCM, MOM, and ROMS. The results show that the spurious dianeutral mixing in the MPAS-Ocean increases over time. The spurious dianeutral transport is proportional to the HGRN directly and is reduced by increasing the lateral viscosity or using a finer resolution to control HGRN. When the HGRN is less than 10, spurious transport is reduced significantly. When using the proper viscosity closure, MPAS-Ocean performs better than MITGCM and MOM, closely to ROMS, in the 2D case without rotation, and much better than the above-mentioned three ocean models under the condition of 3D space with rotation due to the cell area difference between the hexagon cell and the quadrilateral cell with the same resolution. Both the Zalesak (1979) flux corrected transport scheme and Leith closure in MPAS-Ocean play an excellent role in reducing spurious dianeutral mixing. The performance of Leith scheme is preferable to the condition of three-dimensional baroclinic eddy.

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

    Directory of Open Access Journals (Sweden)

    Louise C. Laurent

    2015-08-01

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

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

    Science.gov (United States)

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

    2015-01-01

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

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

    CERN Document Server

    Gao Fei; Weber, W J; Corrales, L R; Jonsson, H

    2003-01-01

    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 alpha-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 alpha-Fe, the possible transition states are studied as a function of interstitial cluster size, and the lowest energy barriers corr...

  14. 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.

  15. 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

  16. Extraction of structural and chemical information from high angle annular dark-field image by an improved peaks finding method.

    Science.gov (United States)

    Yin, Wenhao; Huang, Rong; Qi, Ruijuan; Duan, Chungang

    2016-09-01

    With the development of spherical aberration (Cs) corrected scanning transmission electron microscopy (STEM), high angle annular dark filed (HAADF) imaging technique has been widely applied in the microstructure characterization of various advanced materials with atomic resolution. However, current qualitative interpretation of the HAADF image is not enough to extract all the useful information. Here a modified peaks finding method was proposed to quantify the HAADF-STEM image to extract structural and chemical information. Firstly, an automatic segmentation technique including numerical filters and watershed algorithm was used to define the sub-areas for each atomic column. Then a 2D Gaussian fitting was carried out to determine the atomic column positions precisely, which provides the geometric information at the unit-cell scale. Furthermore, a self-adaptive integration based on the column position and the covariance of statistical Gaussian distribution were performed. The integrated intensities show very high sensitivity on the mean atomic number with improved signal-to-noise (S/N) ratio. Consequently, the polarization map and strain distributions were rebuilt from a HAADF-STEM image of the rhombohedral and tetragonal BiFeO3 interface and a MnO2 monolayer in LaAlO3 /SrMnO3 /SrTiO3 heterostructure was discerned from its neighbor TiO2 layers. Microsc. Res. Tech. 79:820-826, 2016. © 2016 Wiley Periodicals, Inc.

  17. Essential features influencing collaboration in team-based non-specific back pain rehabilitation: Findings from a mixed methods study.

    Science.gov (United States)

    Hellman, Therese; Jensen, Irene; Bergström, Gunnar; Brämberg, Elisabeth Björk

    2016-05-01

    The aim of the study presented in this article was to explore how professionals, without guidelines for implementing interprofessional teamwork, experience the collaboration within team-based rehabilitation for people with back pain and how this collaboration influences their clinical practice. This study employed a mixed methods design. A questionnaire was answered by 383 participants and 17 participants were interviewed. The interviews were analysed using content analysis. The quantitative results showed that the participants were satisfied with their team-based collaboration. Thirty percent reported that staff changes in the past year had influenced their clinical practice, of which 57% reported that these changes had had negative consequences. The qualitative findings revealed that essential features for an effective collaboration were shared basic values and supporting each other. Furthermore, aspects such as having enough time for reflection, staff continuity, and a shared view of the team members' roles were identified as aspects which influenced the clinical practice. Important clinical implications for nurturing and developing a collaboration in team-based rehabilitation are to create shared basic values and a unified view of all team members' roles and their contributions to the team. These aspects need to be emphasised on an ongoing basis and not only when the team is formed.

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

    Directory of Open Access Journals (Sweden)

    Papadimitriou Anastasios

    2007-07-01

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

  19. A (Not Really) Complex Method for Finding Solutions to Linear Differential Equations. Modules and Monographs in Undergraduate Mathematics and Its Applications Project. UMAP Unit 497.

    Science.gov (United States)

    Uebelacker, James W.

    This module considers ordinary linear differential equations with constant coefficients. The "complex method" used to find solutions is discussed, with numerous examples. The unit includes both problem sets and an exam, with answers provided for both. (MP)

  20. A genetic-algorithm-based method to find the unitary transformations for any de- sired quantum computation and application to a one-bit oracle decision problem

    OpenAIRE

    Bang, Jeongho; Yoo, Seokwon

    2014-01-01

    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 ...

  1. Molecular collective dynamics in solid para-hydrogen and ortho-deuterium: The Parrinello-Rahman-type path integral centroid molecular dynamics approach

    Science.gov (United States)

    Saito, Hiroaki; Nagao, Hidemi; Nishikawa, Kiyoshi; Kinugawa, Kenichi

    2003-07-01

    The single-particle and collective dynamics of hydrogen/deuterium molecules in solid hcp para-hydrogen (p-H2) and ortho-deuterium (o-D2) has been investigated by using the path integral centroid molecular dynamics (CMD) simulations at zero-pressure and 5.4 and 5.0 K, respectively. For this purpose, we have newly unified the standard CMD method with the Parrinello-Rahman-Nosé-Hoover-chain-type isothermal-isobaric technique. The phonon density of states have been obtained and the dynamic structure factors have been calculated to observe the phonon dispersion relations of both crystals. For solid p-H2, the high energy edge of the phonon energies of solid p-H2 is >13 meV, and the calculated phonon energies are significantly higher than those observed in Nielsen's previous neutron scattering experiments in the energy region >9 meV. The relationship between the present results and the data reported so far is discussed to resolve the outstanding controversy regarding the phonon energies in solid p-H2. On the other hand, the excitation energies for solid o-D2 are in fairly good agreement with those of the neutron experiments. The calculated isothermal compressibility of solid p-H2 is found to be very close to the experimental result.

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

    Science.gov (United States)

    Bublitz, Bruce; Philipich, Kirk; Blatz, Robert

    2015-01-01

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

  3. Use of E2 matrix elements to determine the centroids and fluctuation widths for triaxial quadrupole collective motion

    Science.gov (United States)

    Cline, Douglas; Wu, Ching-Yen

    2001-10-01

    Measured E2 properties are a sensitive and unambiguous probe of the collective shape parameters for quadrupole collective motion in nuclei. Collective motion produces strong correlations of the measured E2 matrix elements that can be related to the E2 properties in the principal axis frame of the rotating nucleus. By analogy with Bohr's quadrupole shape parameters (β,γ), the instantaneous principal axis frame E2 tensor can be expressed in terms of two parameters, Q,δ where E2(2,0)=Q\\cosδ, and E2(2,± 2)=fracQ√2sinδ. The E2 properties can be used to extract the E2 triaxiality parameter δ which can be related to γ by use of a geometrical collective model. The 1965 measurement [1] of the Q_2^+ state in ^114Cd provoked considerable interest in collective triaxial deformation in nuclei and stimulated measurement of Q_2^+ values in many other nuclei in order to probe the centroid of the E2 triaxial deformation. The heavy-ion Coulomb excitation experimental technique, plus the Coulomb excitation least-squares search code GOSIA, made it possible to measure rather complete sets of E2 matrix elements adding a new dimension to the study of triaxiality in nuclear collective motion [2]. This development also made it possible to exploit the rotational invariant technique [3-6] to extract directly from the measured E2 matrix elements, the expectation values of the centroids and fluctuation widths of principal axis E2 parameters for any state. The usefulness, range of validity, and results of this technique for determining the centroids and fluctuation widths for the triaxiality degree of freedom δ in a range of nuclei will be presented. The completeness required is a disadvantage of the rotational invariant technique. A comparison will be made of the use of the full rotational invariant technique with results obtained using restricted E2 data in conjunction with model-dependent analyses or truncation schemes. [1] J. de Boer et al, Phys. Rev. Lett. 14 (1965) 564; [2] D

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

    OpenAIRE

    Stevens, Martin; Hussein, Shereen; Manthorpe, Jill

    2011-01-01

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

  5. 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; Herrera, Claudia; Spivey, Natalie; Fladung, William; Cloutier, David

    2015-01-01

    This presentation describes the DIM method and how it measures the inertia properties of an object by analyzing the frequency response functions measured during a ground vibration test (GVT). The DIM method has been in development at the University of Cincinnati and has shown success on a variety of small scale test articles. The NASA AFRC version was modified for larger applications.

  6. 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.

  7. Centroiding and point response function measurements of the mirror/detector combination for the x-ray telescope on the SWIFT gamma-ray burst explorer

    Science.gov (United States)

    Ambrosi, Richard M.; Abbey, Anthony F.; Hutchinson, Ian; Willingale, Richard; Campana, Sergio; Cusumano, G.; Burkert, Wolfgang; Wells, Alan A.; Short, Alexander T.; Citterio, Oberto; Ghigo, Mauro; Tagliaferri, G.; Braeuninger, Heinrich W.

    2002-01-01

    The essential optical components of the Swift X-ray Telescope (XRT) are already developed items. They are: the flight spare x-ray mirror from the JET-X/Spectrum-X program and a MOS CCD (CCD22) of the type currently operating in orbit as part of the EPIC focal plane camera on the XMM- Newton. The JET-X mirrors were first calibrated at the Max Plank Institute for Extraterrestrial Physics' (MPE) Panter facility, Garching, Germany in 1996. Half energy widths (HEW) of 16 arc seconds at 1.5 keV were confirmed for the two flight mirrors and the flight spare. The calibration of the flight spare was repeated at Panter in July 2000 in order to establish whether any changes had occurred during the four years that the mirror had been in storage at the OAB, Milan, Italy. This results reported in this paper, confirm that the resolution of the JET-X mirrors has remained stable over this storage period. In an extension of this test program, the flight spare EPIC camera was installed at the focus of the JET-X mirror to simulate the optical system of the Swift X-ray telescope. On-axis and off-axis point spread functions (PSFs) were measured and calibration data sets were used to obtain centroid positions of X-ray point sources. The results confirmed Swift's ability to determine the centroid positions of sources at 100mCrab brightness to better than 1 arc second and provided a calibration of the centroiding process as a function of source flux and off axis angle. The presence of background events in the image frame introduced errors in the centroiding process, making the choice of centroiding algorithm important. Algorithm performance and the trade-off between processing speed and centroiding accuracy were investigated.

  8. 基于质心迭代估计的无线传感器网络节点定位算法∗%An improved centroid lo calization algorithm based on iterative computation for wireless sensor network

    Institute of Scientific and Technical Information of China (English)

    蒋锐; 杨震

    2016-01-01

    unknown node are calculated. The anchor node with the weakest RSSI would be replaced by the centroid node. By this method, the closed area surrounded by the anchor nodes inside the unknown node’s communication range is reduced. The location accuracy is increased by the cyclic iterative method. With the change of the anchor node ratio, the communication radius of the unknown node and the effect of RSSI error, the algorithm performance is investigated by using simulated data. The simulation results validate that although the improved centroid localization algorithm performance will be lost when the number of the anchor nodes inside the unknown node communication range decreases, the new approach can achieve good performance under the condition of few anchor nodes inside the unknown node communication range and this method is of strong robusticity against RSSI error disturbance.

  9. Finding Solutions to the Picard Boundary Value Problem via Homotopy Method%用同伦方法求Picard边值问题的解

    Institute of Scientific and Technical Information of China (English)

    李兰; 徐旭

    2008-01-01

    This paper deals with the problem of finding solutions to the Picard boundary problem. In our approach, by means of the homotopy method, the equation considered is linked to a simpler equation by introducing a parameter. We first find the solutions of the simpler equation, and give a priori estimates of" the equa tion we considered, and then one can obtain the solutions of Picard boundary problem by following the path of solutions of Cauchy problem.

  10. Comparing Monte Carlo methods for finding ground states of Ising spin glasses: Population annealing, simulated annealing, and parallel tempering.

    Science.gov (United States)

    Wang, Wenlong; Machta, Jonathan; Katzgraber, Helmut G

    2015-07-01

    Population annealing is a Monte Carlo algorithm that marries features from simulated-annealing and parallel-tempering Monte Carlo. As such, it is ideal to overcome large energy barriers in the free-energy landscape while minimizing a Hamiltonian. Thus, population-annealing Monte Carlo can be used as a heuristic to solve combinatorial optimization problems. We illustrate the capabilities of population-annealing Monte Carlo by computing ground states of the three-dimensional Ising spin glass with Gaussian disorder, while comparing to simulated-annealing and parallel-tempering Monte Carlo. Our results suggest that population annealing Monte Carlo is significantly more efficient than simulated annealing but comparable to parallel-tempering Monte Carlo for finding spin-glass ground states.

  11. Comparing Monte Carlo methods for finding ground states of Ising spin glasses: Population annealing, simulated annealing, and parallel tempering

    Science.gov (United States)

    Wang, Wenlong; Machta, Jonathan; Katzgraber, Helmut G.

    2015-07-01

    Population annealing is a Monte Carlo algorithm that marries features from simulated-annealing and parallel-tempering Monte Carlo. As such, it is ideal to overcome large energy barriers in the free-energy landscape while minimizing a Hamiltonian. Thus, population-annealing Monte Carlo can be used as a heuristic to solve combinatorial optimization problems. We illustrate the capabilities of population-annealing Monte Carlo by computing ground states of the three-dimensional Ising spin glass with Gaussian disorder, while comparing to simulated-annealing and parallel-tempering Monte Carlo. Our results suggest that population annealing Monte Carlo is significantly more efficient than simulated annealing but comparable to parallel-tempering Monte Carlo for finding spin-glass ground states.

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

    Science.gov (United States)

    Backman, Ylva; Gardelli, Viktor

    2015-01-01

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

  13. The Continuing Search to Find a More Effective and Less Intimidating Way to Teach Research Methods in Higher Education

    Science.gov (United States)

    Bell, Robin

    2016-01-01

    Existing literature examining the teaching of research methods highlights difficulties students face when developing research competencies. Studies of student-centred teaching approaches have found increased student performance and improved confidence in undertaking research projects. To develop a student-centred approach, it could be beneficial…

  14. Finding a Way into a Family of Tone Languages: The Story and Methods of the Chatino Language Documentation Project

    Science.gov (United States)

    Cruz, Emily; Woodbury, Anthony C.

    2014-01-01

    We give a narrative description of our ten-year path into the elaborate tonal systems of the Chatino languages (Otomanguean; Oaxaca, Mexico), and of some of the methods we have used and recommend, illustrated with specific examples. The work, ongoing at the time of writing, began when one of us (Cruz), a native speaker of San Juan Quiahije…

  15. 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; Woodworth, Thasia;

    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...

  16. 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; Woodworth, Thasia;

    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)...

  17. 汶川地震前后地磁Z分量的谱质心变化%The Spectrum Centroid Variation in Geomagnetic Z Component Data before and after the Wenchuan Earthquake

    Institute of Scientific and Technical Information of China (English)

    许康生; 辛长江; 李英

    2014-01-01

    Research on the seismo-geomagnetic effect goes back more than 100 years,but the use of modern methods and experimentation began in the middle of the last century.Some geomagnet-ically abnormal changes have been reported before large earthquakes,e.g.,the Alaska earthquake (March 27,1964),the Loma Prieta earthquake (M7.1,Oct,17,1989),and the Iwateken Nairku Hokubu earthquake(M6.1,Sep.3,1998).The Wenchuan earthquake was the largest one after the Tangshan earthquake in China.It is important to explore the mechanism of great earthquakes when studying the Wenchuan earthquake.In this paper,we study vertical component (compo-nent) geomagnetic data observed by three stations (Chengdu station (CDP ),MuLi station (MUL),and XiChang station(XIC))in Sichuan Province,with a data sampling rate of one point per second.The maximum spectral centroid,the average spectral centroid,and the spectral cen-troid standard deviation were calculated hourly over three time segments (May 1,2008 to May 12, 2008,May 1,2009 to May 12,2009,and May 1,2010 to May 12,2010).The purpose of this time segment division is,first,to reduce seasonal disturbance,and,second,to avoid interference in the calculated results due to the data length.The results show that among the maximum spectral cen-troid,the average spectral centroid,and the centroid standard deviation,the spectral centroid vari-ability of CDP is greater than the others in the same time period before the Wenchuan earth-quake,and it rises gradually before the earthquake.Other stations did not show these characteris-tics in the same time segments.So we believe there are significant changes in the geomagnetic Z component spectral centroid at CDP,which is information characteristically associated with a great earthquake.This characteristic is also related to the distance from the station to the earthquake position.The distance is 35 km from the epicenter to CDP,357 km from the epicenter to XIC and 400 km from the epicenter to MUL.Our results suggest

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

    Energy Technology Data Exchange (ETDEWEB)

    Bang, Jeongho [Seoul National University, Seoul (Korea, Republic of); Hanyang University, Seoul (Korea, Republic of); Yoo, Seokwon [Hanyang University, Seoul (Korea, Republic of)

    2014-12-15

    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.

  19. 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.

  20. A comprehensive method for break points finding based on expert system for protection coordination in power systems

    Energy Technology Data Exchange (ETDEWEB)

    Abyaneh, Hossein Askarian; Razavi, Farzad [Department of Electrical Engineering Amirkabir University of Technology (Iran); Al-Dabbagh, Majid [Hydro Tasmania Consulting (Australia); Sedeghi, Hossein [Department of Mathematics Tarbiat Moallem University, Tehran (Iran); Kazemikargar, Hossein [Zanjan University, Zanjan (Iran)

    2007-04-15

    Interconnected power systems are multi-loop structured. In such networks, the determination of settings for all overcurrent relays can be carried out in different forms and may be quite complicated. The main problem for coordination is the determination of starting points, i.e. the location of starting relays in the procedure for settings, which is referred to as break points. In this paper, a powerful approach based on expert system is applied. The rules of the expert system include network configuration, protection systems, fault levels, etc. The method is applied to two networks with different configurations, pilot protection and other protection systems. From the obtained results, it is reviled that the new method is efficient, accurate, comprehensive and more optimal than the previously used graph theory. (author)

  1. Essential features influencing collaboration in team-based non-specific back pain rehabilitation: Findings from a mixed methods study

    OpenAIRE

    Hellman, Therese; Jensen, Irene; Bergström, Gunnar; Brämberg, Elisabeth Björk

    2016-01-01

    ABSTRACT The aim of the study presented in this article was to explore how professionals, without guidelines for implementing interprofessional teamwork, experience the collaboration within team-based rehabilitation for people with back pain and how this collaboration influences their clinical practice. This study employed a mixed methods design. A questionnaire was answered by 383 participants and 17 participants were interviewed. The interviews were analysed using content analysis. The quan...

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

    Directory of Open Access Journals (Sweden)

    Lela Sulaberidze

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

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

    Science.gov (United States)

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

    2015-01-01

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

  4. Finding Family

    Institute of Scientific and Technical Information of China (English)

    LIU YUNYUN

    2010-01-01

    @@ It took 14 years--and just two min-utes-for an adopted Chinese girl to find her biological family. July 21 this year marked the first anniversary of Haley Butler's finding of her biological parents in Maanshan in east China's Anhui Province.

  5. 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…

  6. Ground experiments for finding principles and working out methods for preventing adverse effects of weightlessness on the human organism

    Science.gov (United States)

    Kakurin, L. I.; Gregoryev, A. I.; Mikhailov, V. M.; Tishler, V. A.

    1980-01-01

    A comparative assessment of the effectiveness of different prophylactic procedures to prevent the adverse effects of weightlessness is presented. It is concluded that: physical training is most effective but no single method by itself produces the full effect, and an adjustment of regimes to one another enhances the effect. The approved complex of prophylactic procedures affected basic changes occurring in hypokinesia: deficit of muscular activity, no or reduced BP hydrostatic component, reduced volume of blood circulation, reduced hydration level, and the application of various prophylactic complexes during 49 day antiorthostatic hypodynamia eliminated or reduced the adverse effects of weightlessness in simulation.

  7. Do large polycyclic aromatic hydrocarbons and graphene bend? How popular theoretical methods complicate finding the answer to this question

    Science.gov (United States)

    Karadakov, Peter B.

    2016-02-01

    Theoretical studies of the vibrational frequencies of C6n2H6n (n = 2-12) coronenes, show that, despite full conjugation, delocalization and aromaticity, the stability of the planar geometry rapidly decreases with size. A switch to a nonplanar geometry can be expected at around n = 9-12; any larger gas-phase coronene, including graphene, should be nonplanar. When applied to coronenes, popular quantum chemical methods, including Hartree-Fock and density functional theory, are shown to produce anomalous imaginary frequencies suggesting unrealistic geometry distortions; this reveals a serious methodological problem in calculations on extended systems which needs to be resolved through further basis set development.

  8. An Automated Algebraic Method for Finding a Series of Exact Travelling Wave Solutions of Nonlinear Evolution Equations

    Institute of Scientific and Technical Information of China (English)

    柳银萍; 李志斌

    2003-01-01

    Based on a 0 of elliptic equation, a new algebraic method to construct a series of exact solutions for nonlinear evolution equations is proposed, meanwhile, its complete implementation TRWS in Maple is presented. The TRWS can output a series of travelling wave solutions entirely automatically, which include polynomial solutions, exponential function solutions, triangular function solutions, hyperbolic function solutions, rational function solutions, Jacobi elliptic function solutions, and Weierstrass elliptic function solutions. The effectiveness of the package is illustrated by applying it to a variety of equations. Not only are previously known solutions recovered but also new solutions and more general form of solutions are obtained.

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

    Energy Technology Data Exchange (ETDEWEB)

    Uzonyi, I., E-mail: uzonyi@atomki.hu [Institute of Nuclear Research of the Hungarian Academy of Sciences, H-4026 Debrecen, Bem ter 18/C (Hungary); Csontos, K.; Verebes, A. [Budapest History Museum, Aquincum Museum H-8211 Budapest, Zahony u. 4. (Hungary); Cserhati, C. [Department of Solid State Physics, University of Debrecen H-4032 Debrecen, Bem ter 18/B (Hungary); Csedreki, L.; Kis-Varga, M.; Kiss, A.Z. [Institute of Nuclear Research of the Hungarian Academy of Sciences, H-4026 Debrecen, Bem ter 18/C (Hungary)

    2011-10-15

    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.

  10. Method of superposition of dislocations for finding stress-strain state around fan-shaped structure in a brittle rock

    Science.gov (United States)

    Sadovskii, V. M.; Sadovskaya, O. V.

    2016-10-01

    The Tarasov fan-shaped mechanism, simulating the formation of shear ruptures in a brittle rock at stress conditions corresponding to seismogenic depths, is analyzed. For computation of the stress-strain state of a rock near the equilibrium fan-structure the original method is constructed. The fault is modeled as a narrow elongated layer, filled with the domino-blocks, between two elastic half-spaces. Displacements and stresses around the fan are represented in the integral form as a superposition of edge dislocations with an unknown function of distribution of the Burgers vector. To take into account the stresses of lateral thrust, the solution of plane problem of the elasticity is used for a tensile crack, on the surfaces of which the previously unknown normal stresses are distributed. The exact formulation of the problem leads to a system of two nonlinear singular integral equations, which is solved numerically by the method of successive approximations. The obtained solution is used, when setting the initial data in computations of the dynamics of the Tarasov fan-shaped mechanism. With the help of this solution the discontinuous nature of shear ruptures, observed in natural and laboratory experiments, is explained.

  11. Direct digital method fast-acting analysis of the correlation-interferometric radio direction-finding with reconstructing of spatial analytical

    Directory of Open Access Journals (Sweden)

    V. V. Tsyporenko

    2013-04-01

    Full Text Available Introduction. Nowadays radio control of radio electronic devices must be carried out in the conditions of sticky electromagnetic wicket, large prior uncertainty in relation to the parameters of radiations, and also in the conditions of the real time realization. The use and researches of direct digital methods of correlation-interferometric direction-finding is perspective direction in radio control realization for the indicated terms. Fundamentals of researches. In this paper, the direct digital method fast-acting analysis of the correlation-interferometric radio direction-finding with reconstructing of spatial analytical signal is executed. The estimation of time charges, fast-acting and relative time efficiency of method is executed. Conclusions. It is certain that analyzed direct method of direction-finding provides a spatial selection and simultaneous direction-finding of radiations which get in the pass frequencies band of simultaneous analysis with a width to one hundred ten megahertz real-time with the use of only one signal processor.

  12. [Artifactual defect of inferior myocardium on 123I-metaiodobenzylguanidine myocardial SPECT: characteristic findings and preventive method on phantom study].

    Science.gov (United States)

    Kobayashi, H; Terada, S; Kanaya, S; Kashikura, K; Momose, M; Hosoda, S; Kusakabe, K

    1994-04-01

    Discordance between planar and SPECT image of inferior myocardial defect on 123I-metaiodobenzylguanidine myocardial scintigraphy (MIBG) was occasionally observed in the clinical studies. The purpose of this study is to clarify the existence of artifactual myocardial defect on MIBG SPECT image. Phantom study was performed in various kinds of situation using triple gamma camera. Artifactual defect adjacent to the liver was significantly observed in the case of increased liver/heart uptake ratio more than 2:1. Artifactual defect was markedly observed in the 180 degrees than that in the 360 degrees SPECT acquisition. To avoid artifactual defect during SPECT acquisition, liver phantom was moved down to the foot direction (vanishing liver position). In this phantom position, artifactual defect adjacent to the liver was not observed on reconstructed myocardial SPECT image. The vanishing liver position was also applicable to human study. Human body was inclined to right side at an angle of 15 degrees, artifactual defect could be avoided. Further study is needed to analyze the cause of this artifactual defect and to conform the preventive method with vanishing liver position in the routine myocardial SPECT examination.

  13. Point spread function and centroiding accuracy measurements with the JET-X mirror and MOS CCD detector of the Swift gamma ray burst explorer's X-ray telescope

    Science.gov (United States)

    Ambrosi, R. M.; Abbey, A. F.; Hutchinson, I. B.; Willingale, R.; Wells, A.; Short, A. D. T.; Campana, S.; Citterio, O.; Tagliaferri, G.; Burkert, W.; Brauninger, H.

    2002-08-01

    The optical components of the Swift X-ray telescope (XRT) are already developed items. They are the flight spare X-ray mirror from the JET-X/Spectrum-X program and an MOS CCD (CCD22) of the type currently operating in orbit as part of the EPIC focal plane camera on XMM-Newton (SPIE 4140 (2000) 64). The JET-X mirrors were first calibrated at the Max Plank Institute for Extraterrestrial Physics' (MPE) Panter facility, Garching, Germany in 1996 (SPIE 2805 (1996) 56; SPIE 3114 (1997) 392). Half-energy widths of 16arcsec at 1.5keV were confirmed for the two flight mirrors and the flight spare. The calibration of the flight spare was repeated at Panter in July 2000 in order to establish whether any changes had occurred during the 4yr that the mirror had been in storage at the OAB, Milan, Italy. The results reported in this paper confirm that the resolution of the JET-X mirrors has remained stable over this storage period. In an extension of this test program, the flight spare EPIC camera was installed at the focus of the JET-X mirror to simulate the optical system of the Swift XRT. Tolerances in the mirror focal length, the on-axis and off-axis point spread functions were measured and calibration data sets were used to obtain centroid positions of X-ray point sources. The results confirmed Swift's ability to determine the centroid positions of sources at 100mCrab brightness to better than 1arcsec and provided a calibration of the centroiding process as a function of source flux and off-axis angle. The presence of background events in the image frame introduced errors in the centroiding process and this was accounted for by reducing the sampling area used for the centroiding algorithm.

  14. Intuition based decision making methodology for ranking fuzzy numbers using centroid point and spread

    OpenAIRE

    Abu Bakar, Ahmad Syafadhli Bin

    2015-01-01

    The concept of ranking fuzzy numbers has received significant attention from the research community due to its successful applications for decision making. It complements the decision maker exercise their subjective judgments under situations that are vague, imprecise, ambiguous and uncertain in nature. The literature on ranking fuzzy numbers show that numerous ranking methods for fuzzy numbers are established where all of them aim to correctly rank all sets of fuzzy numbers that mimic real d...

  15. 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.

  16. Dynamic modeling of flexible spacecraft based on floating centroid system%挠性航天器浮动质心动力学建模

    Institute of Scientific and Technical Information of China (English)

    杨一岱; 荆武兴; 刘玥

    2015-01-01

    为提高挠性卫星的姿轨耦合控制精度,针对挠性卫星的姿态动力学建模问题展开研究。采用有限元与牛顿力学相结合的方法,提出一套体现卫星真实质心的浮动运动的浮动质心模型及建立在卫星浮动质心上的高精度动力学模型。利用此模型描述挠性卫星的姿态运动状态,能够准确反映出卫星的姿态运动与轨道运动之间的耦合关系以及卫星附件的挠性振动对卫星质心位置、速度的影响,进而准确估计出在挠性卫星有姿态机动的情况下各动力学要素与动态性能指标受挠性振动的影响,为提高卫星控制精度提供依据。通过仿真计算可知,应用该模型对卫星姿态机动过程进行动力学仿真所得到的结果符合实际工程约束,具有良好的可行性。%In order to improve the accuracy of the attitude⁃orbit coupling control problem of spacecraft with flexible attachments, a study on dynamic modeling of flexible spacecraft is conducted. As a result, a high⁃precision dynamic model based on the floating centroid frame system( FCFS) which can describe the attitude movement of spacecraft as well as the coupling relationship between the attitude maneuvering and the orbit movement better than the old ones is proposed by using the method of Finite⁃element along with Newton mechanics.The simulation result demonstrates that the FCFS model fits the practical restraint well and thus is applicable. The dynamic influence on the spacecraft caused by the vibration of the flexible attachments during the attitude maneuvering procedure can be calculated accurately by using the FCFS model and so is the changing of dynamic factors, such as the the velocity and the displacement of the centroid.The research results can provide theoretical basis for attitude⁃orbit coupling control problem of flexible spacecraft and thus achieve the purpose of improving control accuracy.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2001-11-01

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

  18. 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.

  19. 移动质心再入飞行器建模及自抗扰滚动控制%Moving Centroid Reentry Vehicle Modeling and Active Disturbance Rejection Roll Control

    Institute of Scientific and Technical Information of China (English)

    李自行; 李高风

    2012-01-01

    Based on the moving centroid roll control scheme, a dynamic system molding and coupled nonlinear system control is studied. Differing from the Newtonian mechanics molding and conventional Lagrange mechanics molding used in moving centroid control system molding, a quasi-coordinates Lagrange method is adopted to establish the system dynamics equation, which avoids the complicated force analysis in Newtonian mechanics and the physical meaning implicitness in conventional Lagrange mechanics. In view of the nonlinear, coupling and time-varying nature of the moving centroid roll control system, the active disturbance rejection control (ADRC) technology is adopted to design the attitude controller. The active disturbance rejection controller estimates and compensates for the total unknown disturbances which include the nonlinear coupling parts and external interferences. The active disturbance rejection controller is more robust in disturbance resistance and more adaptable to system parameter changes than the proportion-differential (PD) controller. The feasibility of the entire control system is validated by mathematical simulation.%基于移动质心滚动控制方案,研究了其动力学系统建模和非线性耦合系统控制的问题.不同于移动质心控制系统建模中常用的牛顿力学建模和常规拉格朗日建模法,采用准坐标形式的拉格朗日法建立了完整的系统动力学方程,避免了牛顿力学中复杂的相互作用力分析和常规拉格朗日建模法物理意义不明确的缺点.鉴于移动质心滚动控制系统的非线性、耦合性和时变性,提出把系统的非线性耦合项和外部干扰统归为未知扰动,并采用自抗扰控制(ADRC)技术进行估计和补偿,相对于常用的比例微分(PD)控制,自抗扰控制器能更好地适应系统参数的变化,具有很强的鲁棒性.最后,通过数学仿真验证了整个控制方案的可行性.

  20. Finding Family

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    Discovering her birth parents was an exciting adventure for a 15-year-old girl It took 14 years-and just two minutes-for an adopted Chinese girl to find her biological family.July 21 this year marked the first

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

    Science.gov (United States)

    Quapp, Wolfgang; Kraka, Elfi; Cremer, Dieter

    2007-11-08

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

  2. 舰艇声呐测向精度试验方法%Research on warship sonar direction finding accuracy test method

    Institute of Scientific and Technical Information of China (English)

    刘千里

    2012-01-01

    Indicators to direction finding accuracy of sonar system is a very important warship sonar system of tactical and technical index. Sonar system as an integral part of the combat systems, it provides precision measuring data size, is directly related to the command and control system to torpedo firing solution calculates precision, thus affecting the torpedo firing effect. From theoretic clear direction finding precision index describes the problem, then based on the sonar direction finding system error calibration, accuracy of direction finding sea test route agreement analysis, research and present a modern sonar direction finding precision requirement of high accuracy of finding the true value calculation method, and the arithmetic errors are analyzed in detail.%声呐系统测向精度指标是舰艇声呐系统的一个十分重要的战技指标.声呐系统作为舰艇作战系统的一个重要组成部分,它所提供测量数据精度的大小,直接关系到指控系统对鱼雷射击诸元的解算精度,从而影响鱼雷的射击效果.从理论上明确测向精度指标的描述问题,然后通过对声呐测向系统误差的校准,测向精度海上试验的航路约定的分析,研究并提出一种适应现代声呐高测向精度指标要求的测向精度真值解算方法,并对算法的误差进行详细分析.

  3. Rapid Regional Centroid Solutions

    Science.gov (United States)

    Wei, S.; Zhan, Z.; Luo, Y.; Ni, S.; Chen, Y.; Helmberger, D. V.

    2009-12-01

    The 2008 Wells Nevada Earthquake was recorded by 164 broadband USArray stations within a distance of 550km (5 degrees) with all azimuths uniformly sampled. To establish the source parameters, we applied the Cut and Paste (CAP) code to all the stations to obtain a mechanism (strike/dip/rake=35/41/-85) at a depth of 9km and Mw=5.9. Surface wave shifts range from -8s to 8s which are in good agreement with ambient seismic noise (ASN) predictions. Here we use this data set to test the accuracy of the number of stations needed to obtain adequate solutions (position of the compressional and tension axis) for mechanism. The stations were chosen at random where combinations of Pnl and surface waves were used to establish mechanism and depth. If the event is bracketed by two stations, we obtain an accurate magnitude with good solutions about 80% of the trials. Complete solutions from four stations or Pnl from 10 stations prove reliable in nearly all situations. We also explore the use of this dataset in locating the event using a combination of surface wave travel times and/or the full waveform inversion (CAPloc) that uses the CAP shifts to refine locations. If the mechanism is known (fixed) only a few stations is needed to locate an event to within 5km if date is available at less than 150km. In contrast, surface wave travel times (calibrated to within one second) produce amazing accurate locations with only 6 stations reasonably distributed. It appears this approach is easily automated as suggested by Scrivner and Helmberger (1995) who discussed travel times of Pnl and surface waves and the evolving of source accuracy as the various phases arrive.

  4. Optimal Centroid Position Estimation

    Energy Technology Data Exchange (ETDEWEB)

    Candy, J V; McClay, W A; Awwal, A S; Ferguson, S W

    2004-07-23

    The alignment of high energy laser beams for potential fusion experiments demand high precision and accuracy by the underlying positioning algorithms. This paper discusses the feasibility of employing online optimal position estimators in the form of model-based processors to achieve the desired results. Here we discuss the modeling, development, implementation and processing of model-based processors applied to both simulated and actual beam line data.

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

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Xiu-Hua; Ling, Jian, E-mail: lingjian@ynu.edu.cn; Peng, Jun; Cao, Qiu-E., E-mail: qecao@ynu.edu.cn; Ding, Zhong-Tao; Bian, Long-Chun

    2013-10-10

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

  6. A Centroid Model of Species Distribution to Analyize Multi-directional Climate Change Finger Print in Avian Distribution in North America

    Science.gov (United States)

    Huang, Q.; Sauer, J.; Dubayah, R.

    2015-12-01

    Species distribution shift (or referred to as "fingerprint of climate change") as a primary mechanism to adapt climate change has been of great interest to ecologists and conservation practitioners. Recent meta-analyses have concluded that a wide range of animal and plant species are already shifting their distribution. However majority of the literature has focused on analyzing recent poleward and elevationally upward shift of species distribution. However if measured only in poleward shifts, the fingerprint of climate change will be underestimated significantly. In this study, we demonstrate a centroid model for range-wide analysis of distribution shifts using the North American Breeding Bird Survey. The centroid model is based on a hierarchical Bayesian framework which models population change within physiographic strata while accounting for several factors affecting species detectability. We used the centroid approach to examine large number of species permanent resident species in North America and evaluated the dreiction and magnitude of their shifting distribution. To examine the inferential ability of mean temperature and precipitation, we test a hypothesis based on climate velocity theory that species would be more likely to shift their distribution or would shift with greater magnitude in in regions with high climate change velocity. For species with significant shifts of distribution, we establish a precipitation model and a temperature model to explain their change of abundance at the strata level. Two models which are composed of mean and extreme climate indices respectively are also established to test the influences of changes in gradual and extreme climate trends.

  7. 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

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

    Science.gov (United States)

    Yang, Xiu-Hua; Ling, Jian; Peng, Jun; Cao, Qiu-E; Ding, Zhong-Tao; Bian, Long-Chun

    2013-10-10

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

  10. 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.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2015-08-15

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

  12. Levenberg-Marquardt Method to Find Periodic Solutions of Duffing Equations%解Duffing方程周期解的Levenberg-Marquardt方法

    Institute of Scientific and Technical Information of China (English)

    姜志侠; 李延忠; 李军; 孟品超; 尹伟石

    2013-01-01

    We converted the periodic solution problem of solving differential equations to the unconstrained optimization problem. With the help of the optimality conditions of unconstrained optimization problem, we applied the Levenberg-Marquardt method to finding the periodic solutions of a class of Duffing equations under restrict resonant conditions.%先把求解微分方程的周期解问题转化为无约束最优化问题,再利用无约束最优化问题的最优性条件及Levenberg-Marquardt方法求解了满足限制共振条件下的一类Duffing方程的周期解.数值计算结果表明了方法的有效性.

  13. Simple method to measure effects of horizontal atmospherical turbulence at ground level

    Science.gov (United States)

    Tíjaro Rojas, Omar J.; Galeano Traslaviña, Yuber A.; Torres Moreno, Yezid

    2016-09-01

    The Kolmogorov's theory has been used to explain physical phenomena like the vertical turbulence in atmosphere, others recent works have made new advances and have improved K41 theory. In addition, this theory has been applied to studying different issues associated to measure atmospheric effects, and have special interest to find answers in optics to questions as e.g. at ground level, Could it find edges of two or more close objects, from a distant observer? (Classic resolution problem). Although this subject is still open, we did a model using the statistics of the centroid and the diameter of the laser beam propagated under horizontal turbulence at ground level until the object plane. The goal is to measure efficiently the turbulence effects in the long horizontal path propagation of electromagnetic wave. Natural movement of laser beam within the cavity needs be subtracted from the total transversal displacement in order to obtain a best approach. This simple proposed method is used to find the actual statistics of the centroid and beam diameter on the object plane where the turbulence introduces an additional transversal shift. And it has been tested for different values of horizontal distances under non-controlled environment in a synchronized acquisition scheme. Finally, we show test results in open very strong turbulence with high controlled temperature. This paper presents the implemented tests mainly into laboratory and discuss issues to resolve.

  14. Research on Weighted Centroid Location Algorithm for Wireless Sensor Network%无线传感器网络加权质心定位算法研究

    Institute of Scientific and Technical Information of China (English)

    李文辰; 张雷

    2013-01-01

    针对距离权重的改进质心定位精度受所选反演模型影响,并且正确距离反演模型不容易确定的问题,提出了采用接收信号强度的改进质心定位算法,可将接收信号强度(RSS)作为质心定位算法的权重,直接将权重代入到质心定位算法从而估算出未知节点坐标,取消了距离反演过程,避免了反演误差的引入,提高了算法的定位精度、鲁棒性和实用性,同时还降低了计算复杂度.通过MATLAB平台进行仿真分析得出,改进算法定位性能优于距离权重的改进质心定位算法,符合无线传感器网络定位需求,具有较好的应用价值.%As the positioning precision of the improved weighted centroid location algorithm based on the distance is affected by the selected inversion model and the correct inversion model of distance is not easy to be found, an improved weighted centroid location algorithm based on the received signal strength was introduced in the paper. The received signal strength (RSS) is regarded as the weight of the improved centroid location algorithm. As the inversion process of the distance was cancelled and the inversion errors were avoided, the positioning precision, robustness and availability of the algorithm was improved. At the same time, the computational complexity was reduced. The algorithm simulation results based on MATLAB show that the performance of the improved algorithm is superior to that of the improved weighted centroid location algorithm based on the distance. The improved algorithm can meet the location demands of the wireless sensor network and has good application value.

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

    Science.gov (United States)

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

    2013-11-13

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

  16. 函数条件极值的若干求法%Some methods to find the conditional extremum of functions

    Institute of Scientific and Technical Information of China (English)

    鲁翠仙

    2013-01-01

    In the life,industrial and agricultural production, the economic management and economical accounting, we usually need to solve some practical problems such as how to resolve the minimum input, maximum output, highest benefit,maximize profit,materials most provinces under certain conditions. The solution of these problems is transformed into extreme in mathematics, but these function extreme valve problems are skilled much,hard,flexible, agile. Therefore,discussing the method of solving function extreme has important significance. This paper summarizes some commonly used methods to find the function extremum,and illustrates that we should choose different methods based on the characteristics of the different questions through some typical examples.%  在生活、工农业生产、经济管理和经济核算中,常常要解决在一定条件下要怎么做才会使投入最小,产出最多,效益最高、求利润最大化、用料最省等实际问题,而这些问题的解决就转化到了数学中极值问题,而函数的极值问题技巧性强、难度大、解法灵活,所以函数极值求法的探讨也具有了其重要意义。本文就求函数极值的一些常用方法作了总结,并通过典型例题阐明了求函数极值时,应针对不同的题目的特点选用不同的方法。

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

    CERN Document Server

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

    2002-01-01

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

  18. 无线传感器网络中基于RSSI的质心定位算法研究%Research on centroid positioning algorithm based on RSSI and used in WSN

    Institute of Scientific and Technical Information of China (English)

    周林; 张厚望

    2015-01-01

    无线传感器网络中,由于传统质心算法普遍存在信标节点分布不均与中心化问题,导致定位误差相对较大。针对这些问题,提出了基于RSSI的改进算法。在APIT的基础上,改进算法依靠未知节点接收到不同信标节点的RSSI数值,判断其周围是否存在最佳三角形,若存在则利用最佳三角形进行定位;若不存在则选出一个距其较近的三角形,利用移动信标节点的办法来缩小此三角形的范围进行定位。Matlab平台仿真结果表明,与传统质心算法相比,改进算法减少了定位误差,节点定位精度有所提高。%In wireless sensor network,due to the widespread problems of beacons nodes' uneven distribution and centraliza⁃tion,traditional centroid algorithm has relatively large positioning error. In order to solve these problems,an improved algorithm based on RSSI is proposed. On the basis of APIT,the improved algorithm uses the received signal strength from different bea⁃con nodes to determine whether the surrounding of a unknown node exists the best triangle. If does,the improved algorithm would use the best triangle to locate. If not,the improved algorithm would select a triangle which is closer to the unknown node and use the method of moving beacon node to narrow range of the triangle to locate. The results of Matlab simulation shows that, compared with the traditional centroid algorithm,the improved algorithm can reduce the positioning error and improve the posi⁃tioning accuracy of nodes.

  19. Estimation of degradation parameters of smearing star image based on motion trajectory of star′s centroid%基于星点质心运动轨迹模糊星图退化参数估计

    Institute of Scientific and Technical Information of China (English)

    廖育富; 钟建勇; 陈栋

    2014-01-01

    Star′s gray intensity wouldn′t follow 2-D Gaussian distribution when the rotational velocity exceeded the highest rotational velocity which would affect the processing precision of centroid of star spot. The analytical solution of motion trajectory of star′s centroid was simplified considering that the exposure time was short enough, and then the precision of the linear approximation was analyzed through simulation. The character of gray intensity of smearing star was analyzed based on the simplified trajectory, then a novel algorithm was proposed to estimate the degradation parameters of smearing star image. Through simulation and experiment, the validity of the proposed algorithm has been testified, the largest error of estimated blur length is around 0.8 of a pixel, while error of the estimated blur direction is about 2°, feasibility of the proposed method has also been validated through simulations.%当运动角速度超过允许的最大角速度时,星敏感器工作在动态环境下,星点的灰度特征将不再呈高斯分布,这将影响质心计算的精度。给出了在角速度的影响下星点质心运动轨迹的解析解,并结合曝光时间短的特点,对轨迹的参数方程进行简化并通过仿真分析验证了其精确性。分析了退化星点灰度分布特征,并结合星点质心运动轨迹方程提出基于质心运动轨迹对星图的退化参数进行估计的方法。通过仿真实验,完成了对退化长度及退化方向的估计,对退化长度的估计误差不超过0.8个像素,对退化方向的估计误差不超过2°,并证实了该方法能有效提高质心计算精度。

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

    Science.gov (United States)

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

    2013-06-01

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

  1. 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.

  2. Determination of Critical Slip Surface of Soil Slope by New Complex Method

    Institute of Scientific and Technical Information of China (English)

    Li Liang; Chi Shichun; Lin Gao

    2006-01-01

    A new complex method is presented considering not only the improvement upon the "bad "design point, but also the diversity of the newly generated complex, which is obtained by replacing the "bad "design point with the better design point located at the line between the "bad "design point and the centroid of the remaining design points of the old complex. The new complex method is apphed to searching for the critical slip surface of two non-homogeneous soil slopes. The comparison of the results obtained by the new complex method with that by the basic complex method shows that the new complex method is much more likely to find the true critical surface for the randomly generated initial complex.

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

    Directory of Open Access Journals (Sweden)

    Natalie Lorent

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

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

    Directory of Open Access Journals (Sweden)

    Molaison Elaine

    2011-06-01

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

  5. 基于最大似然估计的加权质心定位算法%Weighted Centroid Localization Algorithm Based on Maximum Likelihood Estimation

    Institute of Scientific and Technical Information of China (English)

    卢先领; 夏文瑞

    2016-01-01

    In solving the problem of localizing nodes in a wireless sensor network,we propose a weighted centroid localization algorithm based on maximum likelihood estimation,with the specific goal of solving the problems of big received signal strength indication (RSSI)ranging error and low accuracy of the centroid localization algorithm.Firstly,the maximum likelihood estimation between the estimated distance and the actual distance is calculated as weights.Then,a parameter k is introduced to optimize the weights between the anchor nodes and the unknown nodes in the weight model.Finally,the locations of the unknown nodes are calculated and modified by using the proposed algorithm.The simulation results show that the weighted centroid algorithm based on the maximum likelihood estimation has the features of high localization accuracy and low cost,and has better performance compared with the inverse distance-based algorithm and the inverse RSSI-based algo-rithm.Hence,the proposed algorithm is more suitable for the indoor localization of large areas.%为解决无线传感器网络中节点自身定位问题,针对接收信号强度指示(received signal strength indication,RSSI)测距误差大和质心定位算法精度低的问题,提出一种基于最大似然估计的加权质心定位算法。首先通过计算将估计距离与实际距离之间的最大似然估计值作为权值,然后在权值模型中,引进一个参数k优化未知节点周围锚节点分布,最后计算出未知节点的位置并加以修正。仿真结果表明,基于最大似然估计的加权质心算法具有定位精度高和成本低的特点,优于基于距离倒数的质心加权和基于RSSI倒数的质心加权算法,适用于大面积的室内定位。

  6. Movements of the Western Pacific Warm Pool Centroid and Their Relationship to Sea Surface Temperature Changes in Ni(n)o Regions

    Institute of Scientific and Technical Information of China (English)

    FANG Mingqiang

    2005-01-01

    By using monthly historical sea surface temperature (SST) data for the years from 1950 to 2000, the Western Pacific Warm Pool (WPWP) climatology and anomalies are studied in this paper. The analysis of WPWP centroid (WPWPC)movement anomalies and the Nino-3 region SST anomalies(SSTA) seems to reveal a close, linear relation between the zonal WPWPC and Nino-3 region SSTA, which suggests that a 9° anomaly of the zonal displacement from the climatological position of the WPWPC corresponds to about a 1℃ anomaly in the Nino-3 region area-mean SST. This study connects the WPWPC zonal displacement with the Nino-3 SSTA, and it may be helpful in better understanding the fact that the WPWP eastward extension is conducive to the Nino-3 region SST increase during an El Nino-Southern Oscillation (ENSO) event.

  7. Alteração no método centroide de avaliação da adaptabilidade genotípica.

    OpenAIRE

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

    2009-01-01

    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 ...

  8. Region-confined restoration method for motion-blurred star image of the star sensor under dynamic conditions.

    Science.gov (United States)

    Ma, Liheng; Bernelli-Zazzera, Franco; Jiang, Guangwen; Wang, Xingshu; Huang, Zongsheng; Qin, Shiqiao

    2016-06-10

    Under dynamic conditions, the centroiding accuracy of the motion-blurred star image decreases and the number of identified stars reduces, which leads to the degradation of the attitude accuracy of the star sensor. To improve the attitude accuracy, a region-confined restoration method, which concentrates on the noise removal and signal to noise ratio (SNR) improvement of the motion-blurred star images, is proposed for the star sensor under dynamic conditions. A multi-seed-region growing technique with the kinematic recursive model for star image motion is given to find the star image regions and to remove the noise. Subsequently, a restoration strategy is employed in the extracted regions, taking the time consumption and SNR improvement into consideration simultaneously. Simulation results indicate that the region-confined restoration method is effective in removing noise and improving the centroiding accuracy. The identification rate and the average number of identified stars in the experiments verify the advantages of the region-confined restoration method.

  9. Using Qualitative Methods for the Analysis of Adult Immigrants’ L2 Needs: Findings from a Research Project in Greece Focusing on School-Parents Communication

    OpenAIRE

    Androulakis, George; Mastorodimou, Efi; VAN BOESCHOTEN, RIKI

    2016-01-01

    In the Greek context of economic crisis and of emerging xenophobic ideas and discourse, this article presents some findings from a research project which had the ambition to give voice to immigrants in Greece about their own language and communication needs. The target group of the project were immigrant parents, whose children attend public schools in the area of Volos. Communication between schools and immigrant families is fragmentary or non-existent, causing frustration for parents and te...

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

    Science.gov (United States)

    Slayton, Julie; Llosa, Lorena

    2005-01-01

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

  11. A Study of Computational Techniques Related to Prediction of Centroids of Dosage Beyond Measured Time Tn Where n is Known.

    Science.gov (United States)

    2014-09-26

    Mathematical Methods for Physicists and Engineers. Reinhold Book Corporation, 199Ŝ. Conover, W.J. Practical Nonparametric Statistics. John Wiley and Sons, N.Y...Julius R., Rosenblatt, Judah. Probability and Statistics, W. B. Saunders Co.,1972. Boas, R.P. The American Mathematical Monthly , Vol. 88, No. 3...Addison- Wesley, Reading, Mass., 1970. Kenney, J.F. and Keeping, E.S. Mathematics of Statistics- Part One. D. Van Nostrand Co., Inc., 1954. *Korn, Granino

  12. A novel accelerometer-based method to describe day-to-day exposure to potentially osteogenic vertical impacts in older adults: findings from a multi-cohort study.

    Science.gov (United States)

    Hannam, K; Deere, K C; Hartley, A; Clark, E M; Coulson, J; Ireland, A; Moss, C; Edwards, M H; Dennison, E; Gaysin, T; Cooper, R; Wong, A; McPhee, J S; Cooper, C; Kuh, D; Tobias, J H

    2017-03-01

    This observational study assessed vertical impacts experienced in older adults as part of their day-to-day physical activity using accelerometry and questionnaire data. Population-based older adults experienced very limited high-impact activity. The accelerometry method utilised appeared to be valid based on comparisons between different cohorts and with self-reported activity.

  13. How to find non-dependent opiate users: a comparison of sampling methods in a field study of opium and heroin users

    NARCIS (Netherlands)

    Korf, D.J.; van Ginkel, P.; Benschop, A.

    2010-01-01

    Background/aim The first aim is to better understand the potentials and limitations of different sampling methods for reaching a specific, rarely studied population of drug users and for persuading them to take part in a multidisciplinary study. The second is to determine the extent to which these d

  14. Impact of Goal Setting and Goal Attainment Methods on Asthma Outcomes: Findings From an Asthma Self-Management Intervention for African American Women

    Science.gov (United States)

    Aaron, Micah; Nelson, Belinda W.; Kaltsas, Elena; Brown, Randall W.; Thomas, Lara J.; Patel, Minal R.

    2017-01-01

    Optimal use of goal-setting strategies in self-management efforts with high-risk individuals with asthma is not well understood. This study aimed to describe factors associated with goal attainment in an asthma self-management intervention for African American women with asthma and determine whether goal attainment methods proved beneficial to…

  15. Striking trends in the incidence of health problems in the Netherlands (2002-05): findings from a new method for record linkage in general practice.

    NARCIS (Netherlands)

    Biermans, M.C.J.; Spreeuwenberg, P.; Verheij, R.A.; Bakker, D.H. de; Vries Robbé, P.F. de; Zielhuis, G.A.

    2009-01-01

    BACKGROUND: This study aimed to detect striking trends based on a new strategy for monitoring public health. METHODS: We used data over 4 years from electronic medical records of a large, nationally representative network of general practices. Episodes were either directly recorded by general practi

  16. Psychological Distress and Help Seeking Amongst Higher Education Students: Findings from a Mixed Method Study of Undergraduate Nursing/Midwifery and Teacher Education Students in Ireland

    Science.gov (United States)

    Deasy, Christine; Coughlan, Barry; Pironom, Julie; Jourdan, Didier; Mannix-McNamara, Patricia

    2016-01-01

    Psychological distress as experienced by higher education students is of major concern because of its potential to adversely impact academic performance, retention, mental health and lifestyle. This paper reports a mixed method investigation of student self-reported psychological distress and help-seeking behaviour. The sample comprised all…

  17. New method of centroid detection in wavefront aberration measurement of human eye%人眼波像差测量中形心探测的新方法

    Institute of Scientific and Technical Information of China (English)

    全薇; 王肇圻; 张春书; 母国光

    2002-01-01

    子孔径光斑的形心探测和计算精度是影响哈特曼传感器波像差探测精度的重要因素,而探测窗口的选取对探测误差的影响很大.分析了Prieto等人采用的逐步缩小窗口尺寸的探测方法,并根据哈特曼波前传感器探测人眼波像差的光斑特点,采用模板匹配法选取光斑窗口的形心探测方法.该方法与Prieto的方法相比提高了探测精度.光斑阵列的仿真计算结果表明,用文中采用的方法探测误差的均方根值降低了53.7%.另外,该方法还避免了Prieto方法中多次迭代计算,减少了运算量.

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

    Science.gov (United States)

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

    2015-12-15

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

  19. Translation methods and procedures applied to Fantastic Beasts and Where to find them and Quidditch Through the Ages by J. K. Rowling

    OpenAIRE

    Mena Velasco, Sonia

    2016-01-01

    This dissertation deals with the analysis of the translation of two books originally written by J. K. Rowling. For this purpose, we have studied translation procedures and translation methods, as well as redundancy and cohesion. We have taken into account experts in translation, such as Newmark, Amparo Hurtado Albir, and Lucía Molina. The aim of this paper is to have a further approach to translation and consequently, understand the process involved in this subject. El presente trabajo se ...

  20. Importance of diagnostic laboratory methods of beta hemolytic streptococcus group A in comparison with clinical findings in the diagnosis of streptococcal sore throat and unnecessary antibacterial therapy

    Directory of Open Access Journals (Sweden)

    Peiman Eini

    2012-04-01

    Full Text Available Background: Streptococcus Pyogenes (group A streptococcus, GAS is the most important cause of bacterial pharyngitis in children and adolescents. Acute pharyngitis is one of the most common conditions in all ages but it is most common in children. Over diagnosis of acute pharyngitis represents one of the major causes of antibiotic abuse. The goal of this study is to make an estimate of the frequency of group A streptococcus in sore throat patients in Farshchian hospital emergency department and clinic in Hamadan. Methods: For estimation of the clinical features role in diagnosis of streptococcal sore throat, we took samples of 100 patients with average age of 32.96±29.86 years with sore throat. We took samples from pharynx and used standard methods of bacteriology in order to detect streptococcus. Results: Group A Streptococcus (GAS accounts for 3 percent of all cases of pharyngitis. Clinically, all of the patients had sore throat. The percent breakdowns are as follows: 30% had exudate, 78% had fever, 8% had lymphadenopathy and 7.7 percent of exudative pharyngitis was streptococcal. The cost for unnecessary antibiotic therapy for every single patient who had negative pharynx culture was approximately 32160 Rails. Conclusion: The low frequency of streptococcus pharyngitis in treated patients reveal that diagnosis based on clinical features is not reliable. We recommend use of other diagnostic methods such as Rapid Antigen Detection Tests (RATs. Only reliable and scientific protocols for antibiotic to therapy.

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

    Directory of Open Access Journals (Sweden)

    Hichem Dkhili

    2013-01-01

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

  2. Artifactual defect of inferior myocardium on [sup 123]I-metaiodobenzylguanidine myocardial SPECT; Characteristic findings and preventive method on phantom study

    Energy Technology Data Exchange (ETDEWEB)

    Kobayashi, Hideki; Terada, Shinichiro; Kanaya, Shinichi; Kashikura, Kenichi; Momose, Mitsuru; Hosoda, Saichi; Kusakabe, Kiyoko (Tokyo Women' s Medical Coll. (Japan))

    1994-04-01

    Discordance between planar and SPECT image of inferior myocardial defect on [sup 123]I-metaiodobenzylguanidine myocardial scintigraphy (MIBG) was occasionally observed in the clinical studies. The purpose of this study is to clarify the existence of artifactual myocardial defect on MIBG SPECT image. Phantom study was performed in various kinds of situation using triple gamma camera. Artifactual defect adjacent to the liver was significantly observed in the case of increased liver/heart uptake ratio more than 2:1. Artifactual defect was markedly observed in the 180 degree than that in the 360 degree SPECT acquisition. To avoid artifactual defect during SPECT acquisition, liver phantom was moved down to the foot direction (vanishing liver position). In this phantom position, artifactual defect adjacent to the liver was not observed on reconstructed myocardial SPECT image. The vanishing liver position was also applicable to human study. Human body was inclined to right side at an angle of 15 degree, artifactual defect could be avoided. Further study is needed to analyze the cause of this artifactual defect and to conform the preventive method with vanishing liver position in the routine myocardial SPECT examination. (author).

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

    Directory of Open Access Journals (Sweden)

    Laszik Andras

    2010-05-01

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

  4. On the Common Type of Cable Faults and Find Methods%论常见的电缆故障类型及其查找方法

    Institute of Scientific and Technical Information of China (English)

    黎沃毅

    2014-01-01

    随着经济和社会的快速发展和人们生活水平的不断提高,各种电器设备被广泛应用于社会生产和生活中,人们对电能的需求量也逐渐增加。为了满足人们不断增长的电能需求,电力行业在电网建设方面投入了许多财力、物力和人力。电缆作为电网的重要组成部分,其质量和运行状况直接关系到电网运行的安全性和稳定性。分析了电缆常见故障的原因,探讨了电缆故障的几种查找方法,以供参考。%With the continuous improvement of rapid economic and social development and people's living standards, a variety of electrical equipment is widely used in social production and life;people demand for electricity is also increasing. In order to meet people's growing electricity demand, power grid construction industry has invested in a number of financial, material and human resources. As an important part of the power cable, and its quality and health is directly related to the security and stability of the power grid operation. Analyzes the causes of the common cable faults, cable faults discussed several lookup methods for reference.

  5. Find a Cancer Doctor

    Science.gov (United States)

    ... Home > Find a Cancer Doctor Find a Cancer Doctor Status message Locating you... The Find an Oncologist ... and caregivers. The database includes the names of physicians and other health professionals from certain ASCO membership ...

  6. Dynamics of Intra-Continental Convergence Between the Western Tarim Basin and Central Tien Shan Constrained by Centroid Moment Tensors of Regional Earthquakes

    Science.gov (United States)

    Huang, Guo-chin Dino; Roecker, Steven W.; Levin, Vadim; Wang, Haitao; Li, Zhihai

    2016-11-01

    Among the outstanding tectonic questions regarding the convergence between the Tien Shan and Tarim basin in northwestern China are the manner in which deformation is accommodated within their lithospheres, and the extent that the Tarim lithosphere underthrusts the Tien Shan. In particular, the amount and type of deformation within the Tarim basin is poorly understood. It is also uncertain if the convergence between the Tarim and the Tien Shan takes place mainly along a discrete boundary, or if the Tarim lithosphere simply indents into the Kazach shield, forming the Tien Shan through crustal thickening accommodated by a distributed series of thrust faults. In this study we use hypocenters from published earthquake catalogs and waveforms recorded by regional seismic networks to determine earthquake source parameters through regional centroid moment tensor inversion. The entire dataset consists of 160 earthquakes that occurred between 1969 and 2009 and with moment magnitudes between 3.5 and 7 distributed throughout the central Tien Shan and northwestern Tarim Basin. The estimated focal depths of these earthquakes range from the near-surface to about 44 km. Focal mechanisms throughout much of the Tien Shan indicate active deformation accommodated by thrust faults from at least the upper crust to 30 km depth. South of the Tien Shan, the Jia-shi earthquake sequence within the Tarim basin suggests that both crustal shortening and localized flexure are part of a complicated process involving rotational convergence. Inside the Tarim basin, two earthquakes with thrust faulting mechanisms near the crust-mantle boundary beneath the Bachu uplift imply a brittle rheology of the lower crust. High-angle thrust events occur broadly across the Tien Shan, suggesting that the Tarim lithosphere as a whole is strong and indents into the Kazach shield to create the mountain range.

  7. Abdominal aspergillosis: CT findings

    Energy Technology Data Exchange (ETDEWEB)

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

    2011-03-15

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

  8. The CASPAR finding aids

    OpenAIRE

    Meghini, Carlo; Avancini, Henry; Versienti, Loredana

    2011-01-01

    One of the CASPAR key components is the FIND Components, which is implementing the Finding Aids of OAIS. According to OAIS, FIND manages Description Information that is associated to Information Packages in order to support the discovery of those Packages. FIND allows defining, creating, persisting, querying, browsing, and accessing both Description Information and the association between Information Packages and Description Information

  9. 结合Harris角点检测和不变质心的稳健图像Hash算法%Robust image Hash algorithm based on Harris corners and invariant centroid

    Institute of Scientific and Technical Information of China (English)

    崔得龙; 左敬龙; 彭志平

    2011-01-01

    提出了应用Harris角点检测和不变质心的图像Hash算法.算法从仿射变换的数学模型出发,利用仿射前后图像质心位置的不变特性,计算Harris角点与不变质心的欧氏距离作为特征向量,最后经编码量化产生图像Hash.实验结果表明:本算法对视觉可接受的JPEG压缩、滤波等具有良好的鲁棒性,而恶意扰动或篡改则会改变Hash值.密钥的使用保证了Hash的安全性.%A novel image Hash algorithm using Harris corners and invariant centroid is proposed. Originating from the mathematical model of affine transform, the distances between Harris corners and invariant centroid are calculated as feature vector,which based on the invariance of centroid of images in the affine transform,finally the feature vectors are compressed to generate the image Hash. Experimental results show that the proposed scheme is robust against perceptually acceptable modifications to the image such as JPEG compression, filtering, while sensitive to excessive changes and malicious tampering. Security of the Hash is guaranteed by using secret keys.

  10. Finding Cryptography in Object Code

    Energy Technology Data Exchange (ETDEWEB)

    Jason L. Wright

    2008-10-01

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

  11. 基于单纯形-重心设计的菜籽粕生物改良菌株的复配研究%Complex formulation of biologically modified strain for rapeseed meal by simplex-centroid mixture design

    Institute of Scientific and Technical Information of China (English)

    钮琰星; 倪光远; 万楚筠; 金虎; 郭勉; 黄庆德; 黄凤洪

    2015-01-01

    Glucosinolates and neutral detergent fiber are two important anti-nutritional factors that limit the feeding value of rapeseed meal. Fermentation is a good method to decrease the anti-nutritional fac-tors in rapeseed meal. The mixed strains and inoculation ratio were optimized by prescreening, the sec-ond screening and mixing design. Identification medium of rapeseed meal was used in prescreening, then the degradation rates of glucosinolates and neutral detergent fiber, the growth curve and protease activity were comprehensively evaluated during the second screening. The inoculation ratio was optimized by sim-plex-centroid mixture design on the basis of the second screening, then the regression equation between factor and response value was fitted. The result showed that the optimal inoculation ratio was obtained as follows:Bacillus subtilis B3 46%, Bacillus natto N1 30% and Saccharomyces cerevisiae R1 24%. Under the optimal condition, the degradation rates of glucosinolates and neutral detergent fiber were 94. 63%and 24. 17% respectively.%硫甙和中性洗涤纤维是限制菜籽粕饲用的两个重要抗营养因子。发酵法是降低菜籽粕抗营养因子的重要手段。通过初筛、复筛和混料设计,优选了混合菌发酵菌株和接种比例。在初筛中采用菜籽粕鉴定培养基,在复筛中对硫甙降解率、中性洗涤纤维降解率、生长曲线和蛋白酶酶活进行综合评价,在复筛的基础上采用单纯形-重心设计进行菌株配比的优化,拟合出因素与响应值之间的回归方程,得到优化的菌株接种比例为枯草芽孢杆菌B346%、纳豆芽孢杆菌N130%、酿酒酵母R124%,在此条件下进行发酵试验,硫甙、中性洗涤纤维的降解率分别为94.63%、24.17%。

  12. 基于锚同心圆的改进加权质心WSN定位算法%An Improved Weighted Centroid Localization Algorithm Based on Concentric Anchor- Beacons for Wireless Sensor Networks

    Institute of Scientific and Technical Information of China (English)

    李尧尧; 廖红云; 曾孝平; 吴小林

    2011-01-01

    Concentric anchor beacons (CAB) localization algorithm is a range -free wireless sensor networks localization algorithm. Comparing with the traditional range localization algorithm, although it can reduce the nodes energy consumption, the localization accuracy is no better than traditional range localization approaches. In order to further improve the accuracy of localizing nodes, an improved weighted centroid algorithm based on CAB is proposed after analyzing the radio propagation path loss. First, the process of this improved algorithm is introduced. Then, the influence of communication radius on the accuracy of this new localization algorithm was simulated. After that, the accuracy of this localization algorithm were compared with the existing several kinds of range - free localization methods. Simulation results show that this new algorithm has a higher positioning accuracy and not sensitive to communication radius, and it has some value in productive practice.%研究无线传感器定位准确性问题,针对测量位置节点信息,为了提高无线传感器网络的定位精度,采用同心圆定位算法(CAB)是一种免测距的无线传感器定位算法,相比于传统的测距方法能降低节点的能量消耗,但是定位精度却不及传统的测距定位方法.提出在同心圆定位算法(CAB)的基础上,通过分析无线电传播路径损耗采用了一种加权同心圆定位算法.给出了算法的流程,仿真分析了通信半径对新算法定位精度的影响,比较了算法定位精度与现有的几种免测距定位方法的定位精度.仿真结果表明,改进算法有较高的定位精度而且对距离不敏感,对实际工程提供应用价值.

  13. Osteoarthritis: Research Findings

    Science.gov (United States)

    ... of this page please turn Javascript on. Feature: Osteoarthritis Research Findings Past Issues / Winter 2013 Table of Contents Research Findings When osteoarthritis involves the hands, small, bony knobs may appear ...

  14. Find a Massage Therapist

    Science.gov (United States)

    ... for Members Student Experience 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 A growing body of research ...

  15. Finding Maximal Quasiperiodicities in Strings

    DEFF Research Database (Denmark)

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

    2000-01-01

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

  16. 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)

  17. 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

  18. Chaff Centroid Jamming and Ship to Air Missile Anti-missile Cooperation Conflict Prediction%箔条质心干扰与舰空弹反导冲突预测问题研究

    Institute of Scientific and Technical Information of China (English)

    孙翼; 韩龙

    2015-01-01

    现代海战中箔条弹与舰空导弹综合使用中存在的电磁干扰冲突严重制约了舰艇的防空反导能力。论文重点针对电磁干扰冲突问题,提出了冲突预测判断原则,构建了冲突预测理论模型,并基于模型采取遍历运算方法对箔条质心干扰与舰空导弹冲突预测进行模拟仿真,对冲突判断模型进行了验证,其结果与实际相吻合。论文的研究可为提升箔条弹与舰空导弹协同作战效能,提高防空反导能力提供重要思路。%In the modern sea warfare ,the electromagnetic conflicts of using the Centroid Jamming and Ship to Air Missile se‐verely restricted the ability of air defence and antimissile .This paper forcused on the electromagnetic interference conflict question , proposed conflict prediction judgment principle ,constructed the conflict prediction model .And based on the model ,this paper used the traversal algorithm to simulate conflict prediction of the chaff centroid jamming and ship to air missile .The results were consist‐ent with the actual situation .The research could enhance the cooperative operation effectiveness of the chaff centroid jamming and ship to air missile ,and improve the ability of air defence and antimissile ,and provide an important idea .

  19. MEMS AO for Planet Finding

    Science.gov (United States)

    Rao, Shanti; Wallace, J. Kent; Shao, Mike; Schmidtlin, Edouard; Levine, B. Martin; Samuele, Rocco; Lane, Benjamin; Chakrabarti, Supriya; Cook, Timothy; Hicks, Brian; Jung, Paul

    2008-01-01

    This slide presentation reviews a method for planet finding using microelectromechanical systems (MEMS) Adaptive Optics (AO). The use of a deformable mirror (DM) is described as a part of the instrument that was designed with a nulling interferometer. The strategy that is used is described in detail.

  20. Hysterosalpingographic findings in infertility

    Energy Technology Data Exchange (ETDEWEB)

    Park, M. S.; Kim, K. S.; Kim, J. S.; Bai, B. C. [Seoul Red Cross Hospital, Seoul (Korea, Republic of)

    1981-12-15

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

  1. Find a Physical Therapist

    Science.gov (United States)

    ... There are numerous benefits to treatment by a physical therapist. Go There » For Patients Choosing Your PT Preparing ... need to know before your appointment with your physical therapist. Go There » Find a PT For Health Professionals ...

  2. Generalizing Experimental Findings

    Science.gov (United States)

    2015-06-01

    Generalizing Experimental Findings Judea Pearl University of California, Los Angeles Computer Science Department Los Angeles, CA, 90095-1596, USA...Selection Bias The classical problem of generalizing experimental findings from the trial sample to the population as a whole, also known as the problem...of “sample selection-bias” (Heckman, 1979; Bareinboim et al., 2014), has received renewed attention in the past decade, as more researchers come to

  3. 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)

  4. Finding optimal exact reducts

    KAUST Repository

    AbouEisha, Hassan M.

    2014-01-01

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

  5. Mobious syndrome: MR findings

    Directory of Open Access Journals (Sweden)

    Maskal Revanna Srinivas

    2016-01-01

    Full Text Available Möbius syndrome is an extremely rare congenital disorder. We report a case of Möbius syndrome in a 2-year-old girl with bilateral convergent squint and left-sided facial weakness. The characteristic magnetic resonance imaging (MRI findings of Möbius syndrome, which include absent bilateral abducens nerves and absent left facial nerve, were noted. In addition, there was absence of left anterior inferior cerebellar artery (AICA and absence of bilateral facial colliculi. Clinical features, etiology, and imaging findings are discussed.

  6. A NEW ITERATIVE METHOD FOR FINDING COMMON SOLUTIONS OF GENERALIZED EQUILIBRIUM PROBLEM, FIXED POINT PROBLEM OF INFINITE k-STRICT PSEUDO-CONTRACTIVE MAPPINGS, AND QUASI-VARIATIONAL INCLUSION PROBLEM

    Institute of Scientific and Technical Information of China (English)

    Liu Min; Zhang Shisheng

    2012-01-01

    In this article,we introduce a hybrid iterative scheme for finding a common element of the set of solutions for a generalized equilibrium problems,the set of common fixed point for a family of infinite k-strict pseudo-contractive mappings,and the set of solutions of the variational inclusion problem with multi-valued maximal monotone mappings and inverse-strongly monotone mappings in Hilbert space.Under suitable conditions,some strong convergence theorems are proved.Our results extends the recent results in G.L.Acedo and H.K.Xu [2],Zhang,Lee and Chan [8],Takahashi and Toyoda [9],Takahashi and Takahashi [10] and S.S.Chang,H.W.Joseph Lee and C.K.Chan [11],S.Takahashi and W.Takahashi [12].Moreover,the method of proof adopted in this article is different from those of [4] and [12].

  7. 基于密度峰值搜索的全极化 SAR 图像分类%Classification method for POLSAR images based on find of density peak

    Institute of Scientific and Technical Information of China (English)

    何伟; 邢孟道

    2016-01-01

    An unsupervised classification method based on find of density peaks(FDP)is proposed for the polarimetric synthetic aperture radar (POLSAR)image.For the great impact of the boundary and strong points in the POLSAR image,the following density becomes unstable.The saliancy image which is based on the infor-mation entropy is proposed to remove these points before classification.The feature in H/-α/A/SPAN space of the remaining pixels is weighted with the saliancy value.Then the unsupervised classification is achieved based on the FDP.In the experiment with the ESAR data,results validate the effectiveness of the new method.%提出一种基于密度峰值搜索(find of density peaks,FDP)的全极化 SAR 图像(polarimetric synthetic aperture radar,POLSAR)无监督分类方法。由于在边缘地带以及奇异点的散射类型复杂,在无监督分类过程中干扰巨大,本文通过构建基于信息熵的显著性图来剔除这一类点的影响,并对剩余部分的参数进行了加权处理。随后在 H/-α/A/SPAN 空间基于 FDP 方法进行无监督分类。最后通过 ESAR 的数据进行了实验验证,结果证明了方法的有效性。

  8. Hepatic angiosarcoma: CT findings

    Institute of Scientific and Technical Information of China (English)

    余日胜; 章士正; 华建明

    2003-01-01

    @@ Hepatic angiosarcoma is a rare malignant vascular tumor. Accurate preoperative diagnosis of this tumor is very difficult if the patient does not have any history of exposure to specific carcinogens including thorotrast, arsenicals and vinyl chloride monomer. We describe CT findings in two cases of hepatic angiosarcoma in combination with a review of the literature.

  9. Tooth Tutoring: The Findings.

    Science.gov (United States)

    Cone, Richard; And Others

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

  10. Finding Health Care Services

    Science.gov (United States)

    If you have been diagnosed with cancer, finding a doctor and treatment facility for your cancer care is an important step to getting the best treatment possible. Learn tips for choosing a doctor and treatment facility to manage your cancer care.

  11. Find a Therapist

    Science.gov (United States)

    ... Teens Treatment Tips for Parents and Caregivers Anxiety Disorders at School School Refusal Test Anxiety News and Research College Students Facts Find Help Tips National Stress Øut Day News and Research Resources Women Facts News and Research Pregnancy and Medication Postpartum ...

  12. Tongue schwannoma: clinicopathological findings.

    Science.gov (United States)

    Catalfamo, Luciano; Lombardo, Giuseppe; Nava, Carla; Familiari, Elena; Petrocelli, Marzia; Iudicello, Valeria; Ieni, Antonio; Barresi, Valeria; De Ponte, Francesco Saverio

    2011-05-01

    Schwannomas are peripheral nerve sheath tumors. Approximately 25% of extracranial schwannomas are located in the head and neck district, but only 1% shows an intraoral origin. We report a case of a 28-year-old patient with a tongue schwannoma. Morphologic analysis and immunohistochemical findings strongly support the diagnosis. Surgical treatment is discussed.

  13. Hepatoerythropoietic porphyria: neuroimaging findings.

    Science.gov (United States)

    Berenguer, J; Blasco, J; Cardenal, C; Pujol, T; Cruces Prado, M J; Herrero, C; Mascaró, J M; de la Torre, C; Mercader, J M

    1997-09-01

    CT and MR findings in two patients with hepatoerythropoietic porphyria are presented. CT scans showed atrophy and cortical mineralization at the same level. MR examination performed in one of the two patients showed mainly frontal cortical atrophy and punctate bright signal on T1- and T2-weighted sequences.

  14. Electroencephalographic findings in panic disorder.

    Science.gov (United States)

    Carvalho, Marcele Regine de; Velasques, Bruna Brandao; Cagy, Mauricio; Marques, Juliana Bittencourt; Teixeira, Silmar; Nardi, Antonio Egidio; Piedade, Roberto; Ribeiro, Pedro

    2013-12-01

    Some studies have reported the importance of electroencephalography (EEG) as a method for investigating abnormal parameters in psychiatric disorders. Different findings in time and frequency domain analysis with regard to central nervous system arousal during acute panic states have already been obtained. This study aimed to systematically review the EEG findings in panic disorder (PD), discuss them having a currently accepted neuroanatomical hypothesis for this pathology as a basis, and identify limitations in the selected studies. Literature search was conducted in the databases PubMed and ISI Web of Knowledge, using the keywords electroencephalography and panic disorder; 16 articles were selected. Despite the inconsistency of EEG findings in PD, the major conclusions about the absolute power of alpha and beta bands point to a decreased alpha power, while beta power tends to increase. Different asymmetry patterns were found between studies. Coherence studies pointed to a lower degree of inter-hemispheric functional connectivity at the frontal region and intra-hemispheric at the bilateral temporal region. Studies on possible related events showed changes in memory processing in PD patients when exposed to aversive stimuli. It was noticed that most findings reflect the current neurobiological hypothesis of PD, where inhibitory deficits of the prefrontal cortex related to the modulation of amygdala activity, and the subsequent activation of subcortical regions, may be responsible to trigger anxiety responses. We approached some important issues that need to be considered in further researches, especially the use of different methods for analyzing EEG signals.

  15. Heterotopic pregnancy: Sonographic findings

    Energy Technology Data Exchange (ETDEWEB)

    Kwon, Tae Hee [CHA General Hospital of Seoul, Pochon CHA University College of Medicine, Seoul (Korea, Republic of)

    1999-03-15

    To evaluate the sonographic findings of the heterotopic pregnancy which is increasing recently. Thirty-nine cases of heterotopic pregnancy after ovulation induction and IVF-ET (In Vitro Fertilization-Embryo Transfer) during the recent 3 years were analyzed. They were diagnosed by ultrasonography and proved surgically afterwards. Sonographic findings were analyzed focusing on gestational week of intrauterine pregnancy and location of ectopic pregnancy. In particular, adnexal mass was evaluated with regard to size and the characteristic findings such as ectopic gestational sac (echogenic ring). Also, overian cyst and fluid collection in cul-de-sac space were reviewed carefully. Heterotopic pregnancy was proved surgically by salpingectomy in 33 cases and by resection of cornus in six cases. Sonographic diagnosis using transvaginal ultrasound was made from five weeks to nine weeks two days (six weeks and four days in average) from last menstral period in all 39 cases. Ectopic pregnancy was identified in ampullary part in 29 cases, in the isthmic portion of tube in four cases and in the cornus of uterus in six cases. The intrauterine pregnancy was diagnosed by identifying the intrauterine gestational saccontaining a yolk sac in seven cases and the embryo with fetal heart beat in the remaining 32 cases. Adnexal masses of heterotopic pregnancy were less than 3 cm in diameter in 2 cases (57%), 3-4 cm in 11 cases (28%) and more than 4 cm in 6 cases (15%). A characteristic finding of ectopic mass was echogenic ring which was visible in 33 (84.6%) cases by transvaginal ultrasound. Six cases had pelvic hematosalpinx and two had pelvic hematoma. Of 10 cases (26%) which were identified to have ovarian hyperstimulation syndrome, eight (21%) had large amount of fluid collection in cul-de-sac and abdomen. Ultrasonographic identification of the intrauterine pregnancy and the ectopic chorion ring is effective for the early diagnosis of the heterotopic pregnancy.

  16. Gallstone ileus: CT findings

    Energy Technology Data Exchange (ETDEWEB)

    Delabrousse, E.; Bartholomot, B.; Sohm, O.; Kastler, B. [Dept. of Radiology A, CHU Jean Minjoz, University of Besancon (France); Wallerand, H. [Dept. of Surgery, CHU Jean Minjoz, University of Besancon (France)

    2000-06-01

    Gallstone ileus is a rare complication of recurrent gallstone cholecystitis. The classic radiographic triad of small bowel obstruction, pneumobilia and ectopic gallstone on abdominal plain radiograph is described with CT imaging. Because of the better resolution of CT compared with abdominal radiography and its recent accession to emergency use, radiologists should be aware of CT findings of gallstone ileus. We report a case in which gallstone ileus was initially diagnosed by CT. (orig.)

  17. Geophysical prospecting method in intrusive rocks area fight a drought to find water wells set%物探方法在侵入岩地区抗旱找水定井中的应用

    Institute of Scientific and Technical Information of China (English)

    宋希利; 宋鹏; 田明阳; 彭玉明

    2012-01-01

    Intrusive rocks in the area of groundwater is difficult to find, but more abundant in the dry season the groundwater more difficult to find, to quickly resolve severe drought disaster in Shandong Yimcngshan people much-needed human and livestock water consumption through advanced and effective geophysical methods and reasonable working arrangement greatly increased drought in the intrusive rocks in the area to find water wells set the speed and rate guarantees as well, by the construction of drilling results verify the geophysical inference realistic, given the success rate of 96% well, single-well water yield are far beyond the estimated amount of water, to find a more extensive local groundwater resources, water resources needed to solve the problem of the masses, the people and the old liberated areas have been highly appreciated by the local government. Proved Yimengshan intrusive rocks in the area of geophysical methods based on different characteristics and be well area is difficult, easy, and CSAMT method were selected degree of resistivity sounding method to find underground water source not only improves the speed and success rate of well set, but also made good hydrogeological effects, it is in similar application areas. Practical work in the specific practice, one can not determine the geological survey of the ground target range and set well drilling difficult areas, the use of controlled source audio magnetotelluric: method is fast and efficient features, to sweep the work surface, suggesting that rock construction of fracture zone, delineated area that is rock crushing low resistance, water lots, and to determine the depth of drilling wells; the second is on the ground within the geological survey to determine, using the resistivity sounding method, the use of a single curve reflects the broken rocks, water section to determine the visual characteristics of the aquifer and depth.%侵入岩地区寻找地下水难度大,而在干旱季节找出较为

  18. Fabrication Aware Form-finding

    DEFF Research Database (Denmark)

    Egholm Pedersen, Ole; Larsen, Niels Martin; Pigram, Dave

    2014-01-01

    parts. The first material system employs a novel rotated joint design to allow the structural tuning of quasi-reciprocal timber frame elements fabricated from multi-axis machined plywood sheet stock. The second em-loys discontinuous post-tensioning to assemble unique precast concrete components......This paper describes a design and construction method that combines two distinct material systems with fabrication aware form-finding and file-to-factory workflows. The method enables the fluent creation of complex materially efficient structures comprising high populations of geometrically unique...

  19. MR findings of ulegyria

    Energy Technology Data Exchange (ETDEWEB)

    Momoshima, Suketaka; Shiga, Hayao; Yuasa, Yuji; Imai, Yutaka; Higuchi, Nobuya (Keio Univ., Tokyo (Japan). School of Medicine); Maezawa, Mariko

    1991-08-01

    Magnetic resonance (MR) findings of the brains diagnosed to have ulegyria were reviewed. The reviewed subjects comprised six epileptic children, ranged from 2 to 16 years of age. All patients had convulsion of tonic-clonic type of various severity and had histories of ischemic-hypoxic or hypoglycemic episode in the perinatal or postnatal period. T{sub 1}-weighted images demonstrated the findings precisely reflecting the salient macroscopic features of ulegyria; localized atrophy of the brain with mushroom-shaped cortical gyri with narrow roots and relatively spared wider crowns. T{sub 2}-weighted images showed the areas of hyperintensity in the subcortical and deep white matter subjacent to the atrophic cortex, suggestive of cicatrical gliosis as well as cystic degeneration. The atrophic gyri were seen in the anterior and/or posterior parasagittal arterial border zones bilaterally with minimal asymmetry. Although these findings were nearly pathognomonic to ulegyria, polymicrogyria could mimic it since both are characterized by abnormally diminutive cortical gyri seen in epileptic children. In polymicrogyria, however, affected gyri are uniformly diminutive and not mushroom-shaped, the cortex is rather thickened than atrophic, the underlying white matter shows no focal hyperintensity, subcortical cystic changes are not present, and affected cortex is not restricted to arterial border zones. Even in one of our cases with extensive ulegyria, it was easy to differentiate it from polymicrogyria since parasagittal regions were most severely affected. Although the previous reports on ulegyria have been exclusively based on postmortem pathological examinations or experimental models, its easy recognition on MRI would contribute to further understanding of its clinical significance and mechanisms. (author).

  20. MR findings of spondylolysis

    Energy Technology Data Exchange (ETDEWEB)

    Ojiri, Hiroya; Fukuda, Kunihiko; Hashimoto, Toru; Doi, Michiko; Irie, Takeo; Tatsuno, Satoshi; Tada, Shinpei (Jikei Univ., Tokyo (Japan). School of Medicine); Toyoda, Keiko

    1994-08-01

    We reviewed MR images of 50 patients with spondylolisthesis to disclose MR findings of spondylolysis. In almost half of our series, spondylolysis was detected as a low signal intensity band traversing in the pairs interarticularis on both T1 and T2 weighted images. Sagittal images was superior to axial image in detection of the low signal intensity band. In some patients, a focal high signal intensity accompanying the low signal intensity band was considered to be fluid collection within pseudoarthrosis due to spondylolysis on T2-weighted image. (author).

  1. Finding things out

    CERN Document Server

    Arthur, Rhona; McCullough, Sheila

    2007-01-01

    Packed with useful information and adviceCovers modern and traditional routes to accessing informationHelps you evaluate the reliability of sourcesHandy checklists at the end of each section summarize the key points Finding Things Out offers solutions to anyone who has ever had trouble tracking down essential information. It describes the techniques that will lead to a successful outcome and covers the full range of resources available, including the World Wide Web, libraries and public record offices. It is a boon to students and researchers needing to trac

  2. Correspondence between constrained transport and vector potential methods for magnetohydrodynamics

    Science.gov (United States)

    Mocz, Philip

    2017-01-01

    We show that one can formulate second-order field- and flux-interpolated constrained transport/central difference (CT/CD) type methods as cell-centered magnetic vector potential schemes. We introduce four vector potential CTA/CDA schemes - three of which correspond to CT/CD methods of Tóth (2000) [1] and one of which is a new simple flux-CT-like scheme - where the centroidal vector potential is the primal update variable. These algorithms conserve a discretization of the ∇ ṡ B = 0 condition to machine precision and may be combined with shock-capturing Godunov type base schemes for magnetohydrodynamics. Recasting CT in terms of a centroidal vector potential allows for some simple generalizations of divergence-preserving methods to unstructured meshes, and potentially new directions to generalize CT schemes to higher-order.

  3. Radiologic findings in neurofibromatosis

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Dai Young; Jeon, Seok Chol; Lee, Kwan Se; Yeon, Kyung Mo; Choo, Dong Woon [Seoul National University College of Medicine, Seoul (Korea, Republic of)

    1979-12-15

    Neurofibromatosis is an uncommon but certainly not a rare hereditary disorder, probably of neuralcrest origin, involving not only neuroectoderm and mesoderm but also endoderm and characterized by cafe au lait spots and cutaneous and subcutaneous tumors, with secondary mesodermal defects responsible for protean osseous abnormalities and various manifestations in other systems. This paper is a study of confirmed 143 cases of neurofibromatosis collected for past 8 years. In this analysis, special attention was given to the selected 37 cases which showed abnormal findings on radiological examinations. Overall male to female ratio was 1 : 1.3. The most frequent kind of abnormalities was vertebral kyphoscoliosis in 12 cases. Among the more pathognomonic but uncommon abnormalities to neurofibromatosis, we experienced each 2 cases of lambdoid defect, pseudoarthrosis and renovascular hypertension, and 1 cases of sphenoid bone absence.

  4. method

    Directory of Open Access Journals (Sweden)

    L. M. Kimball

    2002-01-01

    Full Text Available This paper presents an interior point algorithm to solve the multiperiod hydrothermal economic dispatch (HTED. The multiperiod HTED is a large scale nonlinear programming problem. Various optimization methods have been applied to the multiperiod HTED, but most neglect important network characteristics or require decomposition into thermal and hydro subproblems. The algorithm described here exploits the special bordered block diagonal structure and sparsity of the Newton system for the first order necessary conditions to result in a fast efficient algorithm that can account for all network aspects. Applying this new algorithm challenges a conventional method for the use of available hydro resources known as the peak shaving heuristic.

  5. Learning as way-finding

    DEFF Research Database (Denmark)

    Dau, Susanne

    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......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...

  6. Electroencephalographic findings in panic disorder

    Directory of Open Access Journals (Sweden)

    Marcele Regine de Carvalho

    2013-12-01

    Full Text Available Some studies have reported the importance of electroencephalography (EEG as a method for investigating abnormal parameters in psychiatric disorders. Different findings in time and frequency domain analysis with regard to central nervous system arousal during acute panic states have already been obtained. This study aimed to systematically review the EEG findings in panic disorder (PD, discuss them having a currently accepted neuroanatomical hypothesis for this pathology as a basis, and identify limitations in the selected studies. Literature search was conducted in the databases PubMed and ISI Web of Knowledge, using the keywords electroencephalography and panic disorder; 16 articles were selected. Despite the inconsistency of EEG findings in PD, the major conclusions about the absolute power of alpha and beta bands point to a decreased alpha power, while beta power tends to increase. Different asymmetry patterns were found between studies. Coherence studies pointed to a lower degree of inter-hemispheric functional connectivity at the frontal region and intra-hemispheric at the bilateral temporal region. Studies on possible related events showed changes in memory processing in PD patients when exposed to aversive stimuli. It was noticed that most findings reflect the current neurobiological hypothesis of PD, where inhibitory deficits of the prefrontal cortex related to the modulation of amygdala activity, and the subsequent activation of subcortical regions, may be responsible to trigger anxiety responses. We approached some important issues that need to be considered in further researches, especially the use of different methods for analyzing EEG signals. Keywords: Electroencephalography, panic disorder, neurobiology, brain mapping.

  7. Effective Method for Finding the Lead-zinc and Gold-Preponderant Mines in Fengtai Area%陕西凤太地区寻找优势矿种铅锌金的有效方法

    Institute of Scientific and Technical Information of China (English)

    陈明寿; 武晓迪; 温深文; 陈二虎; 张选固

    2015-01-01

    Fengtai area is our important region focused on the lead-zinc and gold, ant it is also a hot spot district for see-king the lead-zinc and gold which have the big potential and good condition for prospecting the lead-zinc and gold deposits. Here we accumulated a lot of experiences and moral in searching for the deeply-burried lead-zinc and gold, and also make a significant breakthrough.The most effective method for prospecting the deeply-burried lead-zinc mines is make a deeper investigation and proceed in an orderly ways along the ore body, mineralized stratum, mineral-controlled anticline.Here in Fengtai area three gold mines had been explored in forty years, they are Taibai, Sifang and Pangjiahe gold deposits.The measured gold resources in accumulative total is nearly 200 tons.These three gold mines were found by the clue of geochem-ical anormals.The effective method for gold-finding is geochemical secondary halo scanning in first, and geochemical dis-persion trains check when find the normals in second, and confirm with geochemical primary halo in third, and verify with geochemical method in the end.These four steps can achieve the purpose of ore prospecting which have the characteristic s of less-investment, operate quickly and easy-to-accomplish steps.%凤太地区是我省重要的铅锌金矿集中区,也是寻找铅锌金矿的热点地区,具备有寻找铅锌金矿的潜力和条件. 在寻找深部隐伏铅锌矿和金矿方面积累了大量的经验和教训,也取得了重大突破. 寻找隐伏铅锌矿最有效的方法就是沿着矿体、含矿地层、控矿背斜顺藤摸瓜循序渐进. 凤太地区近四十年左右的时间找了三个金矿(太白金矿、四方金矿(也叫八卦庙金矿)、庞家河金矿) ,累计探明黄金资源量近200 t,三大金矿的发现都是化探异常提供的线索. 找金矿的有效方法,先用化探次生晕扫面,有异常再用化探分散检查定位,再用化探原生晕地化剖面进行检查确

  8. Compressive measurement and feature reconstruction method for autonomous star trackers

    Science.gov (United States)

    Yin, Hang; Yan, Ye; Song, Xin; Yang, Yueneng

    2016-12-01

    Compressive sensing (CS) theory provides a framework for signal reconstruction using a sub-Nyquist sampling rate. CS theory enables the reconstruction of a signal that is sparse or compressible from a small set of measurements. The current CS application in optical field mainly focuses on reconstructing the original image using optimization algorithms and conducts data processing in full-dimensional image, which cannot reduce the data processing rate. This study is based on the spatial sparsity of star image and proposes a new compressive measurement and reconstruction method that extracts the star feature from compressive data and directly reconstructs it to the original image for attitude determination. A pixel-based folding model that preserves the star feature and enables feature reconstruction is presented to encode the original pixel location into the superposed space. A feature reconstruction method is then proposed to extract the star centroid by compensating distortions and to decode the centroid without reconstructing the whole image, which reduces the sampling rate and data processing rate at the same time. The statistical results investigate the proportion of star distortion and false matching results, which verifies the correctness of the proposed method. The results also verify the robustness of the proposed method to a great extent and demonstrate that its performance can be improved by sufficient measurement in noise cases. Moreover, the result on real star images significantly ensures the correct star centroid estimation for attitude determination and confirms the feasibility of applying the proposed method in a star tracker.

  9. Cannabinoid findings in children hair - what do they really tell us? An assessment in the light of three different analytical methods with focus on interpretation of Δ9-tetrahydrocannabinolic acid A concentrations.

    Science.gov (United States)

    Moosmann, Bjoern; Roth, Nadine; Hastedt, Martin; Jacobsen-Bauer, Andrea; Pragst, Fritz; Auwärter, Volker

    2015-05-01

    hair 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.

  10. Tomography finds waste sites

    Science.gov (United States)

    Bush, Susan M.

    Geophysical diffraction tomography (GDT), a remote sensing method, is being developed for hazardous waste site characterization by researchers at Oak Ridge National Laboratory, Tenn., with the support of the U.S. Army Toxic and Hazardous Materials Agency, Aberdeen Proving Ground, Md.More accurate assessment of hazardous sites translates into more efficient and less costly cleanup efforts by defining parameters such as waste site boundaries, geophysical site characteristics, buried container leakage, and hazardous material migration. Remote sensing devices eliminate the potential for environmental damage, safety hazards, or high costs associated with intrusive site characterization techniques.

  11. Imaging findings of biliary hamartomas

    Institute of Scientific and Technical Information of China (English)

    Rong-Qin Zheng; Bo Zhang; Masatoshi Kudo; Hirokazu Onda; Tatsuo Inoue

    2005-01-01

    AIM: To evaluate the imaging findings of biliary hamartomas (von Meyenburg complexes, VMCs) and discuss the differential diagnosis with other related diseases.METHODS: Imaging findings of biliary hamartomas on ultrasonography (US), computed tomography (CT), magnetic resonance imaging (MRI), MR cholangiopancreatography (MRCP)and hepatobiliary scintigraphy were retrospectively analyzed in six patients.RESULTS: On ultrasound images, five of the six cases showed multiple small hyper- and hypo-echoic lesions with comet-tail echoes, especially when magnified by US with the usage of zoom function. In all the six cases,multiple tiny hypodense lesions less than 10 mm in diameter were revealed as scattered throughout the liver with no enhancement on CT. These tiny lesions were demonstrated to be hyper- and hypo-intensity on T2- and TI-weighed images, respectively, in three patients who underwent MRI examinations. MRCP was performed in two patients, and clearly showed multiple tiny irregular- and round-shaped hyper-intensity lesions.MRCP and hepatobiliary scintigraphy showed normal appearances of intra- and extra-hepatic bile ducts in two and one patients, respectively.CONCLUSION: Imaging modalities are useful in the diagnosis and differential diagnosis of VMCs. A correct diagnosis might be obtained when typical imaging findings are present even without a histological confirmation.

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

    Directory of Open Access Journals (Sweden)

    Qi Wang

    2015-06-01

    Full Text Available In this paper, a method of using a one-dimensional position-sensitive detector (PSD by replacing charge-coupled device (CCD to measure the movement of the interference fringes is presented first, and its feasibility is demonstrated through an experimental setup based on the principle of centroid detection. Firstly, the centroid position of the interference fringes in a fiber Mach-Zehnder (M-Z interferometer is solved in theory, showing it has a higher resolution and sensitivity. According to the physical characteristics and principles of PSD, a simulation of the interference fringe’s phase difference in fiber M-Z interferometers and PSD output is carried out. Comparing the simulation results with the relationship between phase differences and centroid positions in fiber M-Z interferometers, the conclusion that the output of interference fringes by PSD is still the centroid position is obtained. Based on massive measurements, the best resolution of the system is achieved with 5.15, 625 μm. Finally, the detection system is evaluated through setup error analysis and an ultra-narrow-band filter structure. The filter structure is configured with a one-dimensional photonic crystal containing positive and negative refraction material, which can eliminate background light in the PSD detection experiment. This detection system has a simple structure, good stability, high precision and easily performs remote measurements, which makes it potentially useful in material small deformation tests, refractivity measurements of optical media and optical wave front detection.

  13. Density functional Theory Based Generalized Effective Fragment Potential Method (Postprint)

    Science.gov (United States)

    2014-07-01

    computational cost and, therefore, extends the range of applicability of EFP2 to larger system sizes. 15. SUBJECT TERMS chemistry , computational, computer... chemistry , physics, material, and biological sciences be- cause accurate first principles methods are computationally demanding with increasing system...example in methane , the LMO centroid locations occur along the four C–H bonds axes. Note that different LMOs result in different sets of polarizability

  14. Method

    Directory of Open Access Journals (Sweden)

    Xixin Wang

    2012-01-01

    Full Text Available ZrO2 nanotube arrays were prepared by anodization method in aqueous electrolyte containing (NH42SO4 and NH4F. The morphology and structure of nanotube arrays were characterized through scanning electron microscope, X-ray diffraction, and infrared spectra analysis. The zirconia nanotube arrays were used as catalyst in esterification reaction. The effects of calcination temperature and electrolyte concentration on catalytic esterification activity have been investigated in detail. Experiments indicate that nanotube arrays have highest catalytic activity when the concentration of (NH42SO4 is 1 mol/L, the concentration of NH4F is 1 wt%, and the calcination temperature is 400°C. Esterification reaction yield of as much as 97% could be obtained under optimal conditions.

  15. Immunological findings in autism.

    Science.gov (United States)

    Cohly, Hari Har Parshad; Panja, Asit

    2005-01-01

    elevated in autistic brains. In measles virus infection, it has been postulated that there is immune suppression by inhibiting T-cell proliferation and maturation and downregulation MHC class II expression. Cytokine alteration of TNF-alpha is increased in autistic populations. Toll-like-receptors are also involved in autistic development. High NO levels are associated with autism. Maternal antibodies may trigger autism as a mechanism of autoimmunity. MMR vaccination may increase risk for autism via an autoimmune mechanism in autism. MMR antibodies are significantly higher in autistic children as compared to normal children, supporting a role of MMR in autism. Autoantibodies (IgG isotype) to neuron-axon filament protein (NAFP) and glial fibrillary acidic protein (GFAP) are significantly increased in autistic patients (Singh et al., 1997). Increase in Th2 may explain the increased autoimmunity, such as the findings of antibodies to MBP and neuronal axonal filaments in the brain. There is further evidence that there are other participants in the autoimmune phenomenon. (Kozlovskaia et al., 2000). The possibility of its involvement in autism cannot be ruled out. Further investigations at immunological, cellular, molecular, and genetic levels will allow researchers to continue to unravel the immunopathogenic mechanisms' associated with autistic processes in the developing brain. This may open up new avenues for prevention and/or cure of this devastating neurodevelopmental disorder.

  16. Method

    Directory of Open Access Journals (Sweden)

    Andrey Gnatov

    2015-01-01

    Full Text Available Recently repair and recovery vehicle body operations become more and more popular. A special place here is taken by equipment that provides performance of given repair operations. The most interesting things are methods for recovery of car body panels that allow the straightening without disassembling of car body panels and damaging of existing protective coating. Now, there are several technologies for repair and recovery of car body panels without their disassembly and dismantling. The most perspective is magnetic-pulse technology of external noncontact straightening. Basics of magnetic-pulse attraction, both ferromagnetic and nonferromagnetic thin-walled sheet metal, are explored. Inductor system calculation models of magnetic-pulse straightening tools are presented. Final analytical expressions for excited efforts calculation in the tools under consideration are introduced. According to the obtained analytical expressions, numerical evaluations of excited forces were executed. The volumetric epures of the attractive force radial distributions for different types of inductors were built. The practical testing of magnetic-pulse straightening with research tools is given. Using the results of the calculations we can create effective tools for an external magnetic-pulse straightening of car body panels.

  17. 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.

  18. 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.

  19. 改进的向量质心模型在实时信息检索中的应用研究%ON APPLYING IMPROVED VECTOR CENTROID MODEL IN REAL-TIME INFORMATION RETRIEVAL

    Institute of Scientific and Technical Information of China (English)

    刘绍翰; 王箭; 黄志球

    2011-01-01

    Applying relevant feedback technology to information retrieval is one of the effective means to improve the effect of information retrieval in which users' information demand can be learnt and determined and the retrieved results can conduct information filtration. Apart from the accuracy and recall, the adaptability and speed of filtration algorithm also impacts the experience of the user in employing the information retrieval system directly. The authors used vector space model to represent the content of document. It is less workload in pre-treatment and simple in computation and is adapted to real-time information retrieval. In combination of the rationale with least deviation, in the paper they apply the improved centroid of feedback document to information rearrangement. The simulation of the applying scene of rearrangement is executed on TREC Filtering Task dataset, and the test comparison is made between it with the keyword-based retrieval and the class-centroid based retrieval means.%将相关反馈技术应用于信息检索中可以学习和明确用户的信息需求,并对检索结果进行信息过滤,是提高信息检索效果的有效手段之一.除了准确率和召回率之外,过滤算法的适应性、速度也直接影响用户使用信息检索系统的体验.采用向量空间模型表示文档的内容预处理工作少,计算简单,适用于实时信息检索.结合偏差最小的基本原理,将改进的反馈文档向量的质心应用于信息重排.以重排的应用场景,在TREC Filtering Task数据集上进行仿真,并与基于关键词检索和类质心的检索方式进行了试验比较.

  20. Finding overlapping communities using seed set

    Science.gov (United States)

    Yang, Jin-Xuan; Zhang, Xiao-Dong

    2017-02-01

    The local optimization algorithm using seed set to find overlapping communities has become more and more a significant method, but it is a great challenge how to choose a good seed set. In this paper, a new method is proposed to achieve the choice of candidate seed sets, and yields a new algorithm to find overlapping communities in complex networks. By testing in real world networks and synthetic networks, this method can successfully detect overlapping communities and outperform other state-of-the-art overlapping community detection methods.

  1. 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.

  2. MR findings of polymyositis / dermatomyositis

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Hak Soo; Joo, Kyung Bin; Moon, Won Jin; Lee, Tae Hee; Park, Ki Ho; Park, Dong Woo; Hahm, Chang Kok [Hanyang Univ. College of Medicine, Seoul (Korea, Republic of)

    1998-07-01

    The purpose of this study was to evaluate the MR findings and useful sequences in Polymyositis/ Dermatomyositis, and to correlate MR findings with disease activity. Materials and Methods: The study included nine clinically proven cases of Polymyositis/Dermatomyositis, eight involving the thigh and one, the shoulder (2 cases, 1 follow-up). The contrast between affected and normal muscles and difference in signal intensity ratio in the muscle groups were retrospectively evaluated on Gd-enhanced T1WI and T2WI. We also evaluated the magnitude of involvement of muscle groups, fatty replacement of muscle and change of subcutaneous fat layer, and correlated signal intensity ratio with serum level of muscle enzymes. Differences in signal intensity ratio and the frequency of chemical shift artifact were evaluated on T2WI as active and inactive groups classified according to clinical findings, and the chemical shift artifact was correlated with the finding of Gd-enhanced T1WI. Except in the case of one shoulder, statistical analysis was assessed by the Anova test and-test. Results: On Gd-enhanced T1WI and T2WI contrast was 0.54 and 0.82, respectively and p value was 0.02. With regard to difference in signal intensity ratios of muscle groups, as seen on Gd-enhanced T1WI and T2WI, p valves were 0.07 and < 0.01, respectively. Muscle involvement was thus clearly visualized on T2WI. The order of frequency of involved muscle groups was vastus muscles, gluteus maximus, sartorius muscles, adductor muscles, gracilis muscle, and hamstring muscles. Fatty replacement and subcutaneous fatty change were visualized in five cases and one, respectively. The correlation coefficient between the signal intensity seen on T2WI and muscle enzymes was 0.59 (CPK) and 0.52 (LDH). The chemical-shift artifact was detected in both clinical groups (four active two inactive) and corresponded to one case of muscle involvement and five of perimuscular edema, as seen on Gd-enhanced T1WI. Conclusion: T2WI is

  3. ON THE CONVERGENT ITERATION METHOD OF ORDER TWO FOR FINDING ZEROS OF THE DERIVATIVE%再论求导数零点的二次收敛迭代法

    Institute of Scientific and Technical Information of China (English)

    王兴华; 李冲

    2001-01-01

    In this paper, we continues to study the convergent iterationmethod of order two given by the first author for finding zeros of the derivative. Under one global condition on the function, instead of two, the convergence determinations are established by using quadratic and cubical majorizing functions respectively.

  4. Findings

    Science.gov (United States)

    ... injury and repair. Read Issue Elizabeth Grice, Geneticist Body Bacteria Elizabeth Grice studies the bacteria that live on human skin. Her work could lead to new ways to treat chronic wounds like diabetic foot ulcers. Read Issue George Hightower, M.D.-Ph.D. Graduate Student HIV on the Brain George ...

  5. Initial findings from a mixed-methods evaluation of computer-assisted therapy for substance misuse in prisoners: Development, implementation and clinical outcomes from the ‘Breaking Free Health & Justice’ treatment and recovery programme

    Directory of Open Access Journals (Sweden)

    Sarah Elison

    2015-08-01

    examine the processes of implementation of this novel digital health programme and the various barriers and facilitators of this, including the practicalities of providing an online treatment programme in an environment in which there are multiple, complex security requirements and considerations. Additionally, the acceptability of the BFHJ programme to prisoners who may have limited experience of using online technologies was also explored. Clinical outcomes in terms of the programmes impact on substance dependence and use were also examined. Methods: In line with the Medical Research Council (MRC guidelines around development and evaluation of complex interventions (Craig et al., 2008, a mixed-methods approach was used including a qualitative study to explore the implementation of this online treatment programme within the secure prison environment, and offender perceptions of this novel, technology-enhanced approach to substance misuse treatment. In addition, quantitative data derived from a battery of standardised psychometric assessments was used to examine clinical effectiveness of BFHJ. Results: In order to meet MoJ security requirements prior to implementation, the BFHJ programme had to be reviewed and ‘white listed’ by NOMS and their security partner XMA to ensure the programme met all security, quality and information assurance processes and standards. This was a lengthy and costly process that entailed freshly developing the programme in partnership with VC experts at NOMS to ensure the programme is ‘sterile’ i.e., there are no holes in the system or links to external websites – this comprised some aspects of the programme content and resulted in some clinical techniques requiring reworking e.g., removing Google maps from one section of the programme. Themes emerging from qualitative data around offenders experiences of BFHJ illustrate its potential for use in prison settings and also to provide, for the first time, genuine continuity of care during

  6. Simple benchmark for complex dose finding studies.

    Science.gov (United States)

    Cheung, Ying Kuen

    2014-06-01

    While a general goal of early phase clinical studies is to identify an acceptable dose for further investigation, modern dose finding studies and designs are highly specific to individual clinical settings. In addition, as outcome-adaptive dose finding methods often involve complex algorithms, it is crucial to have diagnostic tools to evaluate the plausibility of a method's simulated performance and the adequacy of the algorithm. In this article, we propose a simple technique that provides an upper limit, or a benchmark, of accuracy for dose finding methods for a given design objective. The proposed benchmark is nonparametric optimal in the sense of O'Quigley et al. (2002, Biostatistics 3, 51-56), and is demonstrated by examples to be a practical accuracy upper bound for model-based dose finding methods. We illustrate the implementation of the technique in the context of phase I trials that consider multiple toxicities and phase I/II trials where dosing decisions are based on both toxicity and efficacy, and apply the benchmark to several clinical examples considered in the literature. By comparing the operating characteristics of a dose finding method to that of the benchmark, we can form quick initial assessments of whether the method is adequately calibrated and evaluate its sensitivity to the dose-outcome relationships.

  7. 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)

  8. Sonographic Findings of Uterine Endometrial Stromal Sarcoma

    OpenAIRE

    Kim, Jeong-Ah; Lee, Myung Sook; Choi, Jong-Sun

    2006-01-01

    Objective The study was performed to present the sonographic findings of uterine endometrial stromal sarcoma (ESS). Materials and Methods We conducted a retrospective review of sonographic findings of 10 cases that were diagnosed as uterine ESS. The patients' ages ranged from 25 to 51 years (mean age: 36.1 years). The reviews focused on the location, margin, size, number and echotexture of the lesions. Hysterectomy (n = 9) and myomectomy (n = 1) were performed and a pathologic diagnosis was o...

  9. Effect of Fixed Centroid Line on the Performance of Soil Throw Through Reverse Rotary Tillage%不动形心线对逆转耕耘抛土性能的影响

    Institute of Scientific and Technical Information of China (English)

    刘永清; 宋志禹

    2016-01-01

    Based on the analysis of reverse rotary work , the effect of the fixed centroid line ( FCL) line effect on the re-versal rotary work was proposed .A detailed analysis of the regulation of FCL effect was given in the reverse rotary blade moving track , reverse rotary cutting angle and reverse rotary tillage backward throw of soil , and a model for instantaneous velocity direction at the beginning of soil throwing of reverse rotary is established , and the model is simulated .It provides a reference basis for the design of tillage machine in tea garden .The main conclusion: The rotary tillage can work nor-mally only when the FCL distance is less than the rotary shaft radius , and FCL which located above rotary shaft is for re-verse rotary work mode , FCL which located below rotary shaft is for forward rotary work mode .In reverse rotary mode , when the blade running to FCL , dynamic cutting angle will be minimum .Only when FCL is located above reverse rotary shaft and located below the ground surface , it will has backward throw of soil .%在分析逆转旋耕工作的基础上,提出了不动形心线( Fixed Centroid Line-FCL )对逆转耕耘方式影响的思想。在旋耕刀片运动轨迹、逆转旋耕切削角度及逆转旋耕抛土后向性等方面,详细分析了 FCL 线的影响性质,建立了逆转旋耕被抛土垡瞬时初速度的方向模型,并对模型进行了仿真,为茶园耕作机械的设计提供了参考依据。主要结论:FCL 线距刀辊轴的距离小于刀辊回转半径时,旋耕刀片才能够正常工作,且 FCL 线位于刀辊轴的上方为逆转耕耘方式,位于刀辊轴的下方为正转耕耘方式;在逆转旋耕方式下,当刀片运转到 FCL 线时,动态切土角最小;当FCL 线位于刀辊轴之上,且同时又在地表之下时,逆转旋耕才具有抛土后向性。

  10. Circumcenter, Circumcircle and Centroid of a Triangle

    Directory of Open Access Journals (Sweden)

    Coghetto Roland

    2016-03-01

    Full Text Available We introduce, using the Mizar system [1], some basic concepts of Euclidean geometry: the half length and the midpoint of a segment, the perpendicular bisector of a segment, the medians (the cevians that join the vertices of a triangle to the midpoints of the opposite sides of a triangle.

  11. Center for Research on Infrared Detectors (CENTROID)

    Science.gov (United States)

    2006-09-30

    Average carper energy in a bound-to-continuum detector for va:rious val- ue~ of tow-field capture tillllt . Figure 5. Results of Monte Carlo studies...Orlando and Santa Barbara Focal Plane in the realization of QDIP-based IR cameras. We have fabricated and shipped 320x256 QDIP arrays to them for...International Science Center HRL Laboratories Texas Instruments/DRS Technologies EPIR Limited Lockheed Martin Santa Barbara Focalplane BAE Systems AFRL

  12. Computed tomographic findings of trichuriasis

    Institute of Scientific and Technical Information of China (English)

    Naime Tokmak; Zafer Koc; Serife Ulusan; Ismail Soner Koltas; Nebil Bal

    2006-01-01

    In this report, we present computed tomographic findings of colonic trichuriasis. The patient was a 75-year-old man who complained of abdominal pain, and weight loss.Diagnosis was achieved by colonoscopic biopsy. Abdominal computed tomography showed irregular and nodular thickening of the wall of the cecum and ascending colon.Although these findings are nonspecific, they may be one of the findings of trichuriasis. These findings, confirmed by pathologic analysis of the biopsied tissue and KatoKatz parasitological stool flotation technique, revealed adult Trichuris. To our knowledge, this is the first report of colonic trichuriasis indicated by computed tomography.

  13. 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.

  14. Fast, rugged and sensitive ultra high pressure liquid chromatography tandem mass spectrometry method for analysis of cyanotoxins in raw water and drinking water--First findings of anatoxins, cylindrospermopsins and microcystin variants in Swedish source waters and infiltration ponds.

    Science.gov (United States)

    Pekar, Heidi; Westerberg, Erik; Bruno, Oscar; Lääne, Ants; Persson, Kenneth M; Sundström, L Fredrik; Thim, Anna-Maria

    2016-01-15

    Freshwater blooms of cyanobacteria (blue-green algae) in source waters are generally composed of several different strains with the capability to produce a variety of toxins. The major exposure routes for humans are direct contact with recreational waters and ingestion of drinking water not efficiently treated. The ultra high pressure liquid chromatography tandem mass spectrometry based analytical method presented here allows simultaneous analysis of 22 cyanotoxins from different toxin groups, including anatoxins, cylindrospermopsins, nodularin and microcystins in raw water and drinking water. The use of reference standards enables correct identification of toxins as well as precision of the quantification and due to matrix effects, recovery correction is required. The multi-toxin group method presented here, does not compromise sensitivity, despite the large number of analytes. The limit of quantification was set to 0.1 μg/L for 75% of the cyanotoxins in drinking water and 0.5 μg/L for all cyanotoxins in raw water, which is compliant with the WHO guidance value for microcystin-LR. The matrix effects experienced during analysis were reasonable for most analytes, considering the large volume injected into the mass spectrometer. The time of analysis, including lysing of cell bound toxins, is less than three hours. Furthermore, the method was tested in Swedish source waters and infiltration ponds resulting in evidence of presence of anatoxin, homo-anatoxin, cylindrospermopsin and several variants of microcystins for the first time in Sweden, proving its usefulness.

  15. 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

  16. APPLICATION OF THE MULTIRESPONSE OPTIMISATION SIMPLEX METHOD TO THE BIODIESEL - B100 OBTAINING PROCESS

    Directory of Open Access Journals (Sweden)

    Julyane Karolyne Teixeira da Costa

    2016-03-01

    Full Text Available The process of obtaining B100 biodiesel from vegetable oil and animal fat mixtures by transesterification under basic conditions was optimised using the super-modified simplex method. For simultaneous optimisation, yield, cost, oxidative stability and Cold Filter Plugging Point (CFPP, were used as responses, and the limits were established according to the experimental data and the conformity parameters established by legislations. Based on the predictive equations obtained from the simplex-centroid design-coupled functions, the multi-response optimisation showed an optimal formulation containing 38.34 % soybean oil, 21.90 % beef tallow and 39.25 % poultry fat. The validation showed that there are no significant differences between the predicted and experimental values. The simplex-centroid mixture design and simplex optimisation methods were effective tools in obtaining biodiesel B100, using a mixture of different raw materials.

  17. MRI Findings In Dengue Encephalitis

    Directory of Open Access Journals (Sweden)

    Ashraf V.V

    2004-01-01

    Full Text Available Neurological manifestations are rare in dengue fever. Two cases with encephalopathy and systemic features of dengue fever with abnormal CSF and MR imaging are reported. Striking MRI finding was bilateral symmetrical thalamic lesions similar to those reported in Japanese encephalitis. This report highlights that MRI findings can be similar in dengue and Japanese encephalitis.

  18. Electroencephalographic Findings in Posthypoxic Myoclonus

    NARCIS (Netherlands)

    van Zijl, J C; Beudel, M; van der Hoeven, H J; Lange, F; Tijssen, M A J; Elting, J W J

    2015-01-01

    The physical examination findings of early posthypoxic myoclonus (PHM) are associated with poor prognosis. Recent findings indicate that patients with multifocal PHM, assumed to have a cortical origin, have a comparable outcome to resuscitated patients without PHM. Generalized PHM, assumed to have a

  19. CT findings of pancreatic disease

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Mi Sook; Park, In Sook; Jeon, Doo Sung; Kim, Hong Soo; Rhee, Hak Song [Presbyterian Medical Center, Jeonju (Korea, Republic of); Won, Jong Jin [College of Medicine, Wonkwang University, Iri (Korea, Republic of)

    1988-02-15

    CT was found to be a reliable, often specific, and noninvasive method for detecting pancreatic diseases. In a study of pancreatic lesions, 37 cases having satisfactory operative and histological proofs were analyzed by CT at PMC from Jan. 1986 to Oct. 1987. The results were as following: 1. Male:female is 26:11. 2. The incidence of pancreatic disease were as follows: 1) Pancreatic cancer:21 cases (56%) a.Head:12 cases b.Body:4 cases c.Tail:1 case d.Body and tail:1 case e.Uncinate process:2 cases f.Entire pancreas: 1 case 2) Acute pancreatitis: 6 cases (16%) 3) Chronic pancreatitis:5 cases (14%) 3. The characteristic CT findings: 1) 100% of pancreatic head cancer showed focal mass or alteration of pancreatic head contour and biliary tree dilatation, and 33% (7/12) fat line obliteration. 2) All of other pancreatic cancer except head appeared as focal mass or contour alteration and fat line obliteration. 3) Total 6 cases of acute pancreatitis showed that 5 cases diffuse enlargement of pancreas, 3 fluid collection (2 cases:left anterior pararenal and posterior pararenal space and lesser sac, 1 case:only pancreas body) and 1 case abscess formation. 4) Total 5 cases of chronic pancreatitis revealed diffuse enlargement 2 cases and atrophy 1 case, pancreatic ductal dilatation 3 cases, calcification 2 cases, and biliary tree dilatation with CBD tapering appearance 1 case. 5) All cases of pseudocysts were well marginated cystic lesions that located at head in 3 cases and tail 3 cases, and 4 cases were well defined pure cystic masses but 1 case was well capsulated cyst with multiple internal septation.

  20. Post-therapeutic imaging findings

    Energy Technology Data Exchange (ETDEWEB)

    Pollice, Saverio, E-mail: saveriopollice@hotmail.it [Department of Radiology and Neuroradiology, “L. Bonomo Hospital”, 76123 Andria, BT (Italy); Muto, Mario, E-mail: mutomar@tiscali.it [Department of Neuroradiology, “Cardarelli Hospital”, Naples (Italy); Scarabino, Tommaso, E-mail: tscarabino@hotmail.com [Department of Radiology and Neuroradiology, “L. Bonomo Hospital”, 76123 Andria, BT (Italy)

    2015-05-15

    Highlights: • This study is the result of collaboration between neuroradiologists and neurosurgeons. • Comparison between neuroimaging techniques to better evaluate the complications after treatment of the spin. • Evaluation of the imaging features of complications and definition of follow-up. - Abstract: 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

  1. 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).

  2. 一种基于等级法的联网审计绩效评价方法%Performance Assessment Method of Online Auditing Based on Rank-centroid

    Institute of Scientific and Technical Information of China (English)

    陈伟

    2010-01-01

    持续审计是目前审计领域研究的一个前沿问题,我国研究与实施的联网审计也是持续审计的一种实现方式.结合目前我国开展联网审计的现状、特点及需要,研究适合联网审计的绩效评价方法:首先,基于对联网审计的实施成本、效益、审计风险控制等因素的分析,建立了适合联网审计特点的绩效评价指标体系,然后采用等级法确定评价指标权重,在此基础上建立了联网审计的绩效评价模型,最后通过实例分析了本方法的应用.这些工作为研究联网审计绩效评价打下了基础.

  3. Stabilizer Formula of Optimizing Passion Fruit Beverage by Simple Centroid Method%单纯形重心法优化西番莲果汁饮料的稳定剂配方

    Institute of Scientific and Technical Information of China (English)

    聂强; 何仁; 黄永春; 刘惠贤; 付军鹏

    2016-01-01

    [目的]提高西番莲果汁饮料稳定性.[方法]在单因素试验基础上,利用单纯形重心试验法优化西番莲果汁饮料的稳定剂配方.[结果]单因素试验结果表明,黄原胶、果胶、羧甲基纤维素钠(CMC)的稳定效果较好,进一步进行{3,2}单纯形重心试验,复配的结果显示:当黄原胶、果胶、CMC添加量分别为0.089%、0.050%、0.117%,总的添加量为0.256%时,饮料的离心率降低至2.10%.验证试验说明,预测值与验证值相符,产品稳定效果好.[结论]通过上述试验得到的稳定剂配方可靠,稳定性好,可用于西番莲果汁饮料中.

  4. Aspectos radiográficos e ultra-sonográficos dos pacientes submetidos a alongamento ósseo pelo método de Ilizarov Radiographic and sonographic findings in patients submitted to limb lengthening using the Ilizarov method

    Directory of Open Access Journals (Sweden)

    Patrícia Martins e Souza

    2003-12-01

    Full Text Available Neste trabalho foram monitorados, por meio de radiografias simples e ultra-sonografias, dez pacientes submetidos a alongamento ósseo com o uso do fixador externo de Ilizarov, no período de março de 2001 a março de 2002. Os pacientes submetidos ao método de Ilizarov foram principalmente crianças e adolescentes, para correção de anomalias congênitas (seis casos. A correção do encurtamento se deveu a trauma complicado com osteomielite em três pacientes e a ressecção tumoral em um paciente. O fêmur esteve envolvido em 60% dos casos, a tíbia em 30% e a fíbula em 10%. Os achados radiográficos encontrados na evolução normal do regenerado ósseo foram um centro radiotransparente, ossificação linear, reação periosteal, aumento das partes moles e ossificação completa. Os achados da formação do osso novo na ultra-sonografia foram o regenerado anecóico, ecos esparsos no sítio de distração, ecos lineares alinhados longitudinalmente, ecos grosseiros e amorfos e calcificação completa. Ocorreram 15 complicações em seis pacientes: cisto no regenerado (cinco casos, infecção adjacente aos pinos (quatro casos, coleção em partes moles (três casos, consolidação precoce (dois casos e retardo na consolidação (um caso.Ten patients treated with Ilizarov external fixator for limb lengthening were monitored with radiographs and sonography examinations between March, 2001 and March, 2002. Most of the patients were children and adolescents who were submitted to surgery for correction of congenital deformities (six cases. In three patients shortening was secondary to post-traumatic osteomielitis and in one patient due to tumor resection. The femur was affected in 60%, tibia in 30% and fibula in 10% of the cases. The main radiographic findings of bone regeneration during the normal process of limb lengthening were lucent areas, linear ossification, periosteal reaction, soft tissue abnormalities and complete consolidation

  5. Ultrasonographic findings of testicular tumors: Correlation with pathologic findings

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Yong Joo; Koh, Byung Hee; Oh, Jae Cheon; Kim, Bong Soo; Kim, Yong Soo; Rhim, Hyen Chul; Cho, On Koo; Hahm, Chang Kok; Park, Hae Young; Lee, Jung Dal [Hanyang University College of Medicine, Seoul (Korea, Republic of)

    1999-03-15

    Scrotal sonography is a valuable tool for assessing the testis and surrounding structures, and has become the imaging modality of choice for evaluation of the scrotum. Scrotal sonography is also helpful for differentiating cystic from slid mass and testicular from extratesticular mass, but is sometimes difficult in differentiating malignant tumor from various benign conditions such as epidermoid cyst, focal orchitis, testicular hematoma, and abscess. We demonstrate the sonographic findings of the various testicular mass, and correlation with pathologic findings.

  6. A method to search for bulk motions in the ICM with {\\sl Chandra} CCD spectra: application to the Bullet cluster

    CERN Document Server

    Liu, Ang; Tozzi, Paolo; Zhu, Zong-Hong

    2015-01-01

    We propose a strategy to search for bulk motions in the intracluster medium (ICM) of merging clusters based on {\\sl Chandra} CCD data. Our goal is to derive robust measurements of the average redshift of projected ICM regions obtained from the centroid of the $K_\\alpha$ line emission. We thoroughly explore the effect of the unknown temperature structure along the line of sight to accurately evaluate the systematic uncertainties on the ICM redshift. We apply our method to the "Bullet cluster" (1E~0657-56). We directly identify 23 independent regions on the basis of the surface brightness contours, and measure the redshift of the ICM averaged along the line of sight in each. We find that the redshift distribution across these regions is marginally inconsistent with the null hypothesis of a constant redshift or no bulk motion in the ICM, at a confidence level of about $2\\, \\sigma$. We tentatively identify the regions most likely affected by bulk motions and find a maximum velocity gradient of about $(46\\pm 13)$ ...

  7. Asking about Sex in General Health Surveys: Comparing the Methods and Findings of the 2010 Health Survey for England with Those of the Third National Survey of Sexual Attitudes and Lifestyles.

    Directory of Open Access Journals (Sweden)

    Philip Prah

    Full Text Available Including questions about sexual health in the annual Health Survey for England (HSE provides opportunities for regular measurement of key public health indicators, augmenting Britain's decennial National Survey of Sexual Attitudes and Lifestyles (Natsal. However, contextual and methodological differences may limit comparability of the findings. We examine the extent of these differences between HSE 2010 and Natsal-3 and investigate their impact on parameter estimates.Complex survey analyses of data from men and women in the 2010 HSE (n = 2,782 men and 3,588 women and Natsal-3 undertaken 2010-2012 (n = 4,882 men and 6,869 women aged 16-69y and resident in England, both using probability sampling, compared their characteristics, the amount of non-response to, and estimates from, sexual health questions. Both surveys used self-completion for the sexual behaviour questions but this was via computer-assisted self-interview (CASI in Natsal-3 and a pen-and-paper questionnaire in HSE 2010.The surveys achieved similar response rates, both around 60%, and demographic profiles largely consistent with the census, although HSE participants tended to be less educated, and reported worse general health, than Natsal-3 participants. Item non-response to the sexual health questions was typically higher in HSE 2010 (range: 9-18% relative to Natsal-3 (all <5%. Prevalence estimates for sexual risk behaviours and STI-related indicators were generally slightly lower in HSE 2010 than Natsal-3.While a relatively high response to sexual health questions in HSE 2010 demonstrates the feasibility of asking such questions in a general health survey, differences with Natsal-3 do exist. These are likely due to the HSE's context as a general health survey and methodological limitations such as its current use of pen-and-paper questionnaires. Methodological developments to the HSE should be considered so that its data can be interpreted in combination with those from dedicated

  8. Swarm: robust and fast clustering method for amplicon-based studies

    Directory of Open Access Journals (Sweden)

    Frédéric Mahé

    2014-09-01

    Full Text Available Popular de novo amplicon clustering methods suffer from two fundamental flaws: arbitrary global clustering thresholds, and input-order dependency induced by centroid selection. Swarm was developed to address these issues by first clustering nearly identical amplicons iteratively using a local threshold, and then by using clusters’ internal structure and amplicon abundances to refine its results. This fast, scalable, and input-order independent approach reduces the influence of clustering parameters and produces robust operational taxonomic units.

  9. Chest radiographic findings of leptospirosis

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Mee Hyun; Jung, Hee Tae; Lee, Young Joong; Yoon, Jong Sup [Hallym University College of Medicine, Seoul (Korea, Republic of)

    1986-04-15

    1. A study on chest radiographic findings of 54 cases with pneumonia like symptoms was performed. Of 54 cases, 8 cases were confirmed to be leptospirosis and 7 cases were leptospirosis combined with Korean hemorrhagic fever. 2. Of 8 cases of leptospirosis, 4 cases showed abnormal chest radiographic findings: acinar nodular type 2, massive confluent consolidation type 2. Of 7 cases of leptospirosis combined with Korean hemorrhagic fever: acinar nodular type 3, massive confluent consolidation type 1, and increased interstitial markings type 1 respectively. 3. It was considered to be difficult to diagnose the leptospirosis on chest radiographic findings alone, especially the case combined with Korean hemorrhagic fever.

  10. Imaging findings of sternal abnormalities

    Energy Technology Data Exchange (ETDEWEB)

    Franquet, T. [Dept. of Radiology, Hospital de Sant Pau, Universidad Autonoma de Barcelona (Spain); Gimenez, A. [Dept. of Radiology, Hospital de Sant Pau, Universidad Autonoma de Barcelona (Spain); Alegret, X. [Dept. of Radiology, Hospital de Sant Pau, Universidad Autonoma de Barcelona (Spain); Sanchis, E. [Dept. of Radiology, Hospital de Sant Pau, Universidad Autonoma de Barcelona (Spain); Rivas, A. [Dept. of Radiology, Hospital Vall d`Hebron, Universidad Autonoma de Barcelona (Spain)

    1997-05-01

    Radiographic findings in the sternal abnormalities are often nonspecific, showing appearances from a localized benign lesion to an aggressive lesion as seen with infections and malignant neoplasms. A specific diagnosis of sternal abnormalities can be suggested on the basis of CT and MR characteristics. Familiarity with the presentation and variable appearance of sternal abnormalities may aid the radiologist is suggesting a specific diagnosis. We present among others characteristic radiographic findings of hemangioma, chondrosarcoma, hydatid disease, and SAPHO syndrome. In those cases in which findings are not specific, cross-sectional imaging modalities may help the clinician in their management. (orig.)

  11. 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...

  12. Pollution! Find a STEM solution!

    Science.gov (United States)

    Takač, Danijela; Moćan, Marina

    2016-04-01

    Primary and secondary school Pantovčak is an innovative school in downtown Zagreb, Croatia. The school is involved in many projects concerning STEM education. Pollution! Find a STEM solution! is a two year long cross-curricular project that grew out of identified need to develop STEM and ICT skills more. Pisa results make evident that students' knowledge is poor and motivation for math and similar subjects is low. Implying priorities of European Commission, like e-learning, raises motivation and also develops basic skills and improves knowledge in science, math, physic, ICT. Main objectives are to increase students' interest in STEM education and careers and introduce them to all available new trends in technology, engineering and science in their region by visiting clean technology industries and strengthening links with them, to introduce some future digital jobs and prepare students for rapid technological changes by integrating ICT into classroom practice more, to highlight the importance of global environmental issues and improve the knowledge in the areas of sustainable development and renewable energy, to develop collaborative partnership between schools and the wider community in formal, non-formal and informal learning, to support multilingualism by publishing Open Educational Resources in 8 different languages and to strengthen the professional profile of the teaching profession. The project brings together 231 teachers and 2729 students from five different European countries in learning to think globally and work on activities that contribute to the community's well-being. There are altogether 33 activities, divided in 4 categories. STEM activities are focused on students building the devices for measuring air, light and noise pollution in their school and homes. They use the scientific method to analyze the data and compare the results with their peers to find a solution. Eskills, digital literacy and digital jobs are focused on introducing career

  13. Can the Onset of Type 2 Diabetes Be Delayed by a Group-Based Lifestyle Intervention in Women with Prediabetes following Gestational Diabetes Mellitus (GDM? Findings from a Randomized Control Mixed Methods Trial

    Directory of Open Access Journals (Sweden)

    Angela O’Dea

    2015-01-01

    Full Text Available Objective. To evaluate a 12-week group-based lifestyle intervention programme for women with prediabetes following gestational diabetes (GDM. Design. A two-group, mixed methods randomized controlled trial in which 50 women with a history of GDM and abnormal glucose tolerance postpartum were randomly assigned to intervention (n=24 or wait control (n=26 and postintervention qualitative interviews with participants. Main Outcome Measures. Modifiable biochemical, anthropometric, behavioural, and psychosocial risk factors associated with the development of type 2 diabetes. The primary outcome variable was the change in fasting plasma glucose (FPG from study entry to one-year follow-up. Results. At one-year follow-up, the intervention group showed significant improvements over the wait control group on stress, diet self-efficacy, and quality of life. There was no evidence of an effect of the intervention on measures of biochemistry or anthropometry; the effect on one health behaviour, diet adherence, was close to significance. Conclusions. Prevention programmes must tackle the barriers to participation faced by this population; home-based interventions should be investigated. Strategies for promoting long-term health self-management need to be developed and tested.

  14. 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 ...

  15. Dermoscopy Findings of Hidroacanthoma Simplex

    Directory of Open Access Journals (Sweden)

    Yota Sato

    2014-05-01

    Full Text Available Hidroacanthoma simplex (HAS, also known as intraepidermal eccrine poroma, is a rare eccrine adnexal tumor that tends to be misdiagnosed as other types of benign skin tumor, including clonal seborrheic keratosis. Notably, HAS is sometimes misdiagnosed and treated by cryosurgery as seborrheic keratosis, which could trigger the later development of porocarcinoma. Therefore, accurate diagnosis of HAS is indispensable for dermatologists to avoid the development of malignant tumors by an unsuitable treatment. In this report, we present the characteristic dermoscopy findings of HAS. Indeed, the dermoscopy findings might be related to the melanin-rich necrotic cells in the epidermis, which are quite different from dermoscopy findings of clonal seborrheic keratosis. As a previous report suggested, it is difficult for a dermatologist to differentiate HAS from clonal seborrheic keratosis by the naked eye. Our findings might be supportive for the early diagnosis of HAS.

  16. Finding an Eye Care Professional

    Science.gov (United States)

    ... article rating hospitals in the United States. Website: http://health.usnews.com/best-hospitals For More Information ... ophthalmologists in the United States and abroad. Website: https://secure.aao.org/aao/find-ophthalmologist The American ...

  17. Radiographic findings in liveborn triploidy.

    Science.gov (United States)

    Silverthorn, K G; Houston, C S; Newman, D E; Wood, B J

    1989-01-01

    The detailed radiographic features of triploidy, a fatal congenital disorder with 69 chromosomes, have not previously been reported. Radiographs of ten liveborn infants with chromosomally confirmed triploidy showed six findings highly suggestive of this diagnosis: harlequin orbits, small anterior fontanelle, gracile ribs, diaphyseal overtubulation of long bones, upswept clavicles and antimongoloid pelvis. Sixteen other less specific findings showed many similarities to those found in trisomy 18.

  18. Radiographic findings in liveborn triploidy

    Energy Technology Data Exchange (ETDEWEB)

    Silverthorn, K.G.; Houston, C.S.; Newman, D.E.; Wood, B.J.

    1989-05-01

    The detailed radiographic features of triploidy, a fatal congenital disorder with 69 chromosomes, have not previously been reported. Radiographs of ten liveborn infants with chromosomally confirmed triploidy showed six findings highly suggestive of this diagnosis: Harlequin orbits, small anterior fontanelle, gracile ribs, diaphyseal overtubulation of long bones, upswept clavicles and antimongoloid pelvis. Sixteen other less specific findings showed many similarities to those found in trisomy 18.

  19. MVDR based unambiguous direction finding method for non-uniform sparse array%无方位模糊的非均匀稀疏阵MVDR测向方法

    Institute of Scientific and Technical Information of China (English)

    李倩茹; 宋志杰; 王良; 杨晴

    2015-01-01

    稀疏阵能够获得更大的阵列孔径,但常规波束形成(Conventional Beam-Forming, CBF)对非均匀稀疏阵测向时会出现方位模糊.提出了一种基于最小方差无畸变响应(Minimal Variance Distortionless Response, MVDR)同局部非稀疏的非均匀稀疏阵(Non-Uniform Sparse Array, NUSA)的设计相结合来抑制方位模糊的方法(NUSA+MVDR),对其无方位模糊现象进行了理论分析,表明 MVDR 这一非线性处理方法对伪峰有很好的抑制能力.针对一种典型的NUSA(Typical NUSA, TNUSA),进行了TNUSA+MVDR数值仿真实验,其结果和理论分析一致,表明:① MVDR有很强的 NUSA 检测能力,在所给仿真条件下,等效阵元间距为 50 倍波长时,仍能很好地抑制方位模糊;② TNUSA+MVDR较阵元数相同的均匀非稀疏阵列的CBF和MVDR有更高的方位分辨力;③阵元数一定, TNUSA+MVDR 方位分辨力随着等效间距增加而提高,最小可分辨角度反比于等效间距;④ 等效间距一定, TNUSA+MVDR 方位分辨力随阵元数增加而增加.海上实验在等效阵元间距为 10 倍波长条件下部分验证了NUSA+MVDR的检测性能.%Sparse array can get large aperture, but it will also lead to azimuth ambiguity if conventional beam-forming (CBF) is used for non-uniform sparse array. In order to solve this problem, the method called NUSA+MVDR is pre-sented, in which minimal variance distortionless response (MVDR) is applied to non-uniform sparse array with local non-sparse element distribution(NUSA), and theoretical analysis indicates that false peaks could be suppressed by this method. For a typical NUSA(TNUSA), numerical simulations are carried out, and the results, which are in good agreement with theoretical analysis, show that: 1. MVDR has great detection performance, as the equivalent element spacing reaches to 50 times of the wavelength under the simulation condition given in this paper, TNUSA+MVDR can still suppress azimuth ambiguity perfectly; 2. Azimuth

  20. 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

  1. Integrated method for adaptability and phenotypic stability analysis = Método integrado para análise de adaptabilidade e estabilidade fenotipica

    OpenAIRE

    Edmar Soares de Vasconcelos; Múcio Silva Reis; Cosme Damião Cruz; Tuneo Sediyama; Carlos Alberto Scapim

    2011-01-01

    The objectives of this study were a description of the Centroid Method, which is used to investigate the phenotypic adaptability of genotypes and the inclusion of new ideotypes therein, creating the Integrated Method for adaptability and phenotypic stability analysis, as well as a comparison of the two methods in a study example. As an applied example of the new proposal, grain yield data of 14 soybean genotypes from experiments at four locations in the state of Minas Gerais were used. In a c...

  2. CT finding of cryptococcal meningitis

    Energy Technology Data Exchange (ETDEWEB)

    Takahashi, Y.; Sato, H.; Ueda, M.; Ito, K.; Matsuoka, T. (Ohkawara Neurosurgical Hospital, Muroran (Japan))

    1981-08-01

    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.

  3. MR findings of cerebral palsy

    Energy Technology Data Exchange (ETDEWEB)

    Yoon, Sang Hum; Chang, Seung Kuk; Cho, Mee Young; Park, Dong Woo; Kim, Jong Deok; Eun, Choong Ki [Pusan Paik Hospital, Pusan (Korea, Republic of)

    1994-11-15

    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.

  4. Nevus of Ota: clinical-ophthalmological findings

    OpenAIRE

    Sebastião Cronemberger; Nassim Calixto; Henrique Leite Freitas

    2011-01-01

    OBJECTIVE: To analyze the clinical and ophthalmological findings of patients with nevus of Ota. METHODS: Retrospective analysis of patients' charts with nevus of Ota. We registered the demographic data, location of the nevus and date of appearance, family history of similar spots, biomicroscopic, gonioscopic, tonometric, ophthalmoscopic and perimetric findings. RESULTS: We included 14 patients, six (43.0%) men and eight (57.0%) women, with a mean age of 21.7±17.5 years. Ten (71%) were mulatt...

  5. Primary hepatic sarcomas: CT findings

    Energy Technology Data Exchange (ETDEWEB)

    Yu, Ri-Sheng; Chen, Ying; Jiang, Biao; Wang, Liu-Hong [Zhejiang University School of Medicine, Department of Radiology, Hangzhou (China); Xu, Xiu-Fang [Zhejiang Medical College, Teaching and Research Group of Radiology, Hangzhou (China)

    2008-10-15

    Primary hepatic sarcomas are rare tumors that are difficult to diagnose clinically. Different primary hepatic sarcomas may have different clinical, morphologic, and radiological features. In this pictorial review, we summarized computed tomography (CT) findings of some relatively common types of hepatic sarcomas, including angiosarcoma, epithelioid hemangioendothelioma (EHE), liposarcoma, undifferentiated embryonal sarcoma (UES), leiomyosarcoma, malignant fibrous histiocytoma (MFH), and carcinosarcoma (including cystadenocarcinosarcoma). To our knowledge, hepatic cystadenocarcinosarcoma has not been described in the English literature. The CT findings in our case are similar to that of cystadenocarcinoma, a huge, multilocular cystic mass with a large mural nodule and solid portion. The advent of CT has allowed earlier detection of primary hepatic sarcomas as well as more accurate diagnosis and characterization. In addition, we briefly discuss the MRI findings and diagnostic value of primary hepatic sarcomas. (orig.)

  6. 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.

  7. 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.)

  8. CT findings of the thymus

    Energy Technology Data Exchange (ETDEWEB)

    Kang, Eun Young; Kim, Yun Hwan; Seol, Hae Young; Chung, Woun Kyun; Suh, Won Hyuck [Korea University College of Medicine, Seoul (Korea, Republic of)

    1987-02-15

    In 14 cases of normal and abnormal thymus proved surgically and histopathologically in korea University Hae Wha Hospital during recent 6 years, the clinical and CT findings were analyzed. 1. Of 14 cases, 2 cases were normal thymus, 5 cases were thymic hyperplasia, 4 cases were benign thymoma, 2 case were malignant thymoma and 1 case was thymic cyst. 2. Of 14 cases, 10 cases were associated with myasthenia gravis, and 7 of these 10 cases were 3rd to 5th decades females. Among 10 cases with myasthenia gravis. 5 cases were thymic hyperplasia, 1 case was benign thymoma, 2 cases were malignant thymoma, and 2 cases were normal thymus. 3. All 5 thymic hyperplasia were associated with myasthenia gravis. CT findings of thymic hyperplasia were normal in 4 cases and increased lobe thickness in 1 case. 4. Of 4 cases of benign thymoma, only 1 case was associated with myasthenia gravis, and all 4 cases were positive findings in CT scan. CT findings of benign thymoma were round or oval soft tissue mass in anterior mediastinum, and 1 case had punctuate calcifications. 5. Of 2 cases of malignant thymoma, all 2 cases were associated with myasthenia gravis and positive findings in CT scan. CT findings of malignant thymoma were anterior mediastinal soft tissue mass with obliteration of the normal fat planes surrounding great vessels. SVC compression, and pleural tumor implants. 6. CT yielded significant diagnostic information of differential diagnosis between thymoma and thymoma hyperplasia in myasthenia gravis patients. Also CT was highly sensitive test in detection of thymoma and determined the extent and invasiveness of thymoma.

  9. Musculoskeletal Findings in Behcet's Disease

    Directory of Open Access Journals (Sweden)

    Ali Bicer

    2012-01-01

    Full Text Available 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 vasculitis, the etiology and exact pathogenesis of the disease are still unclear. Musculoskeletal findings of Behcet's disease, the relationship between Behcet's disease and spondyloarthropathy disease complex, and the status of bone metabolism in patients with Behcet's disease were discussed in this paper.

  10. Neurological findings of Lyme disease.

    Science.gov (United States)

    Pachner, A. R.; Steere, A. C.

    1984-01-01

    Neurologic involvement of Lyme disease typically consists of meningitis, cranial neuropathy, and radiculoneuritis, alone or in combination, lasting for months. From 1976 to 1983, we studied 38 patients with Lyme meningitis. Headache and mild neck stiffness, which fluctuated in intensity, and lymphocytic pleocytosis were the common findings. Half of the patients also had facial palsies, which were unilateral in 12 and bilateral in seven. In addition, 12 patients had motor and/or sensory radiculoneuropathies; asymmetric weakness of extremities was the most common finding. Although incomplete presentations of neurologic involvement of Lyme disease may be confused with other entities, the typical constellation of neurologic symptoms represents a unique clinical picture. PMID:6516450

  11. Scintigraphic findings in ankylosing spondylitis.

    Science.gov (United States)

    Lentle, B C; Russell, A S; Percy, J S; Jackson, F I

    1977-06-01

    A prospective study of bone scintigraphic findings has been carried out in 63 patients, firmly diagnosed as having ankylosing spondylitis. In addition to abnormal uptake of the radiotracer at the sacroiliac joints, a peripheral arthropathy has been a common finding, particularly in the proximal joints, occurring in up to 50% of patients. Increased uptake of radiotracer in the spine has also been found both diffusely and focally. Focal increases have been noted at the apophyseal joints in 40% of patients and in three patients with a sterile intervertebral diskitis, an unusual complication of this disease only diagnosed in two patients after bone scintigraphy.

  12. Fucosidosis: MRI and MRS findings

    Energy Technology Data Exchange (ETDEWEB)

    Oner, Ali Y.; Akpek, Sergin [Gazi University School of Medicine, Department of Radiology, Ankara (Turkey); Cansu, Ali; Serdaroglu, Ayse [Gazi University School of Medicine, Department of Paediatrics, Ankara (Turkey)

    2007-10-15

    Fucosidosis is a rare, autosomal recessive lysosomal storage disease in which fucose-containing glycolipids, glycoproteins, and oligosaccharides accumulate in tissues as a consequence of {alpha}-l-fucosidase enzyme deficiency. We present the MR imaging findings of diffuse white-matter hyperintensity and pallidal curvilinear streak hyperintensity in a 6-year-old Caucasian girl with a diagnosis of fucosidosis based on cDNA isolated from skin fibroblasts. This report also includes the MRS findings of a decreased N-acetylaspartate/choline ratio together with an abnormal peak at 3.8 ppm which expand the knowledge of the neuroradiological spectrum of this rare disease. (orig.)

  13. Finding low-tension communities

    OpenAIRE

    Galbrun, Esther; Golshan, Behzad; Gionis, Aristides; Terzi, Evimaria

    2017-01-01

    Motivated by applications that arise in online social media and collaboration networks, there has been a lot of work on community-search and team-formation problems. In the former class of problems, the goal is to find a subgraph that satisfies a certain connectivity requirement and contains a given collection of seed nodes. In the latter class of problems, on the other hand, the goal is to find individuals who collectively have the skills required for a task and form a connected subgraph wit...

  14. A BLIND METHOD TO DETREND INSTRUMENTAL SYSTEMATICS IN EXOPLANETARY LIGHT CURVES

    Energy Technology Data Exchange (ETDEWEB)

    Morello, G., E-mail: giuseppe.morello.11@ucl.ac.uk [Department of Physics and Astronomy, University College London, Gower Street, WC1E6BT (United Kingdom)

    2015-07-20

    The study of the atmospheres of transiting exoplanets requires a photometric precision, and repeatability, of one part in ∼10{sup 4}. This is beyond the original calibration plans of current observatories, hence the necessity to disentangle the instrumental systematics from the astrophysical signals in raw data sets. Most methods used in the literature are based on an approximate instrument model. The choice of parameters of the model and their functional forms can sometimes be subjective, causing controversies in the literature. Recently, Morello et al. (2014, 2015) have developed a non-parametric detrending method that gave coherent and repeatable results when applied to Spitzer/IRAC data sets that were debated in the literature. Said method is based on independent component analysis (ICA) of individual pixel time-series, hereafter “pixel-ICA”. The main purpose of this paper is to investigate the limits and advantages of pixel-ICA on a series of simulated data sets with different instrument properties, and a range of jitter timescales and shapes, non-stationarity, sudden change points, etc. The performances of pixel-ICA are compared against the ones of other methods, in particular polynomial centroid division, and pixel-level decorrelation method. We find that in simulated cases pixel-ICA performs as well or better than other methods, and it also guarantees a higher degree of objectivity, because of its purely statistical foundation with no prior information on the instrument systematics. The results of this paper, together with previous analyses of Spitzer/IRAC data sets, suggest that photometric precision and repeatability of one part in 10{sup 4} can be achieved with current infrared space instruments.

  15. 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.

  16. MRI findings of enteroviral encephalomyelitis

    Directory of Open Access Journals (Sweden)

    Mohamed Saied Abdelgawad

    2016-09-01

    Conclusion: Enterovirus encephalomyelitis has characteristic lesion locations in the posterior portions of the brain stem, substantia nigra, dentate nucleus and within the anterior horns of spinal cord. Recognition of these findings in the presence of suggestive clinical presentation can help to establish the diagnosis of enterovirus encephalomyelitis.

  17. Finding Your Adult Vaccination Record

    Science.gov (United States)

    ... record, you can search for evidence of your vaccination history. Look in places where you might find other important documents. Here are some tips: Ask parents or other caregivers if they have records of your childhood immunizations. Look through baby books or other saved documents ...

  18. Learning as way-finding

    DEFF Research Database (Denmark)

    Dau, Susanne

    2014-01-01

    Based on empirical case-study findings and the theoretical framework of learning by Illeris coupled with Nonaka & Takeuchis´s perspectives on knowledge creation, it is stressed that learning are conditioned by contextual orientations-processes in spaces near the body (peripersonal spaces) through...

  19. Finding Reliable Health Information Online

    Science.gov (United States)

    ... at NHGRI About About the Institute Budget and Financial Information Divisions Director's Page How to Contact Us Institute ... una búsqueda saludable en Internet Finding Reliable Health Information Online As Internet users quickly discover, an enormous amount of health information ...

  20. 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.

  1. 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.

  2. 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...

  3. Theory, Method and Practice of Neuroscientific Findings in Science Education

    Science.gov (United States)

    Liu, Chia-Ju; Chiang, Wen-Wei

    2014-01-01

    This report provides an overview of neuroscience research that is applicable for science educators. It first offers a brief analysis of empirical studies in educational neuroscience literature, followed by six science concept learning constructs based on the whole brain theory: gaining an understanding of brain function; pattern recognition and…

  4. 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…

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

    Energy Technology Data Exchange (ETDEWEB)

    Chung, Yon Su; Kwon, Soon Tae; Lee, Hwan Do; Kang, Yong Soo; Byun, Ki Yong; Rhee, Kwang Jin [Chungnam National Univ., Taejon (Korea, Republic of). Coll. of Medicine

    1998-02-01

    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.

  6. Comparison of preoperative neuroradiographic findings and surgical findings in lumbar disc herniation

    Energy Technology Data Exchange (ETDEWEB)

    Takahara, Kazuhiro; Sera, Keisuke; Nakamura, Masakazu; Uchida, Takeshi [Nagasaki Mitsubishi Hospital (Japan); Ito, Nobuyuki

    1997-09-01

    Surgical findings in lumbar disc hernia were compared to pre-operative MRI, CTM and myelogram findings. Ninety-one cases were studied using Love`s method. The accuracy of hernia diagnosis in MRI was 59.3%, 41.2% in CTM, and 35.2% in myelogram. At the L5/S1 disc level, the accuracy of hernia diagnosis by CTM and myelogram was decreased. MRI was useful for the diagnosis and cure of lumbar disc herniation. (author)

  7. Interesting bone scans - unusual findings

    Energy Technology Data Exchange (ETDEWEB)

    Dobson, M.; Wadhwa, S.S.; Mansberg, R.; Fernandes, V.B. [Wollongong Hospital, Wollongong, NSW (Australia)

    1997-12-01

    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 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

  8. Nonpalpable breast cancer : mammographic and clinical findings

    Energy Technology Data Exchange (ETDEWEB)

    Seo, Jae Seung; Kim, Eun Kyung; Oh, Ki Keun; Cheon, Young Jik; Lee, Byung Chan [Yonsei Univ. College of Medicine, Seoul (Korea, Republic of)

    1998-08-01

    To evaluate the mammographic and clinical findings of nonpalpable breast cancer. Materials and Methods : In 28 of 607 breast cancer patients examined between January 1994 and April 1997, lesions were nonpalpable. We retrospectively analyzed the mammographic, clinical and pathologic features of 25 patients (28 lesions) whose mammograms we obtained. Results : Among these 25 patients (28 lesions) screening was abnormal in 22; other symptoms were bloody nipple discharge(n=4), and nipple eczema(n=2). The patients were 34-62 (mean 52)years old. Invasive ductal carcinoma(n=13), DCIS(ductal carcinoma in situ, n-12), Paget's disease (n=2), and LCIS(lobular carcinoma in situ, n=1) were found during surgery. Six of 28 lesions(21%) showed evidence of axillary nodal metastasis;the majority arose from the upper outer quadrant of the breast (n=21). The mammographic findings were mass (50%), (and mass with microcalcification, 11%); microcalcification(29%); asymmetrical density(14%); and normal (7%). According to the mammographic density of breast parenchyma, the major finding in the low density group(N1+P1) was mass(9/9), and in the high density group(P2+DY) was microcalcification (12/19). Conclusion : The most common mammographic findings of nonpalpable breast cancer were mass (50%) and microcalcification(29%). Its features varied according to the mammographic density of breast parenchyma;mass was the main finding in the low density group and microcalcification in the high density group.

  9. 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.

  10. Gout: radiographic findings mimicking infection

    Energy Technology Data Exchange (ETDEWEB)

    Rousseau, I.; Raymond-Tremblay, D. [Dept. of Diagnostic Radiology, Centre Hospitalier de l' Univ. de Montreal, Que. (Canada); Cardinal, E. [Dept. of Radiology, Centre Hospitalier de l' Univ. de Montreal, Que. (Canada); Beauregard, C.G. [Dept. of Diagnostic Radiology, Hopital du Sacre-Coeur de Montreal,Que. (Canada); Braunstein, E.M. [Dept. of Radiology, Indiana University Hospital (United States); Saint-Pierre, A. [Rheumatology Unit, Centre Hospitalier de l' Univ. de Montreal, Que. (Canada)

    2001-10-01

    Objective: To describe radiographic features of gout that may mimic infection. Design and patients: We report five patients with acute bacterial gout who presented with clinical as well as radiological findings mimicking acute bacterial septic arthritis or osteomyelitis. Three patients had delay in the appropriate treatment with the final diagnosis being established after needle aspiration and identification of urate crystals under polarized light microscopy. Two patients underwent digit amputation for not responding to antibiotic treatment and had histological findings confirming the diagnosis of gout. Conclusion: It is important for the radiologist to be aware of the radiological manifestations of acute gout that can resemble infection in order to avoid inappropriate diagnosis and delay in adequate treatment. The definitive diagnosis should rely on needle aspiration and a specific search for urate crystals. (orig.)

  11. 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....

  12. Radiological Findings of Michel Aplasia

    Science.gov (United States)

    Umul, Ayse; Demirtas, Hakan; Celik, Ahmet Orhan

    2016-01-01

    Introduction: Congenital abnormalities of the inner ear is the most common cause of neurosensory hearing loss. Michel inner ear deformity is a rare developmental anomaly refers to the total aplasia of the inner ear. It is caused by developmental arrest of otic placode early during the third week of gestational age. Case report: We have discussed here that three year old girl diagnosed Michel aplasia with temporal bone computed tomography (CT) and temporal magnetic resonance imaging (MRI) findings. PMID:27482139

  13. Finding Proofs in Tarskian Geometry

    OpenAIRE

    Beeson, Michael; Wos, Larry

    2016-01-01

    We report on a project to use a theorem prover to find proofs of the theorems in Tarskian geometry. These theorems start with fundamental properties of betweenness, proceed through the derivations of several famous theorems due to Gupta and end with the derivation from Tarski's axioms of Hilbert's 1899 axioms for geometry. They include the four challenge problems left unsolved by Quaife, who two decades ago found some \\Otter proofs in Tarskian geometry (solving challenges issued in Wos's 1998...

  14. Echocardiographic Finding in Anabolic Steroids Abuser Athletics

    OpenAIRE

    B. Haji Moradi; K. Fatahi

    2006-01-01

    Introduction & Objective: Abuse of anabolic steroids in body builders and competitive sports (doping) is common and prevalent in our country. Due to disagreement about cardiovascular side effects of these drugs and existing controversy in published articles, this study was designed to evaluate the echocardiographic finding in athletics who are current user of these drugs. Materials & Methods: Body builders with continues sport for preceding year and at least twice weekly selected and divided ...

  15. Cutaneous Findings in Patients with Acromegaly

    OpenAIRE

    Akoglu, Gulsen; Metin, Ahmet; Emre, Selma; Ersoy, Reyhan; Cakir, Bekir

    2014-01-01

    Background: Acromegaly is a systemic syndrome caused by overproduction of growth hormone. The syndrome affects cutaneous, endocrine, cardiovascular, skeletal, and respiratory systems. Cutaneous manifestations of acromegaly are various, usually being the first presenting findings of the disease. Methods: Dermatological examinations of 49 patients of acromegaly who were followed-up at a tertiary referral hospital.Results: The study included 27 (55.1%) female and 22 (44.9%) male patients. The on...

  16. CT findings of thymic tumors

    Energy Technology Data Exchange (ETDEWEB)

    Chung, Ho Son; Lee, Sang Jin; Hwang, Mi Soo; Cho, Kil Ho; Chang, Jae Chun; Park, Bok Hwan [College of Medicine, Yeungnam University, Daegu (Korea, Republic of)

    1991-05-15

    A CT scan can make accurate diagnoses of most thymic masses by assessing their size, shape, and internal architecture and is especially effective in detecting pleural implants, mediastinal involvement, and pulmonary parenchymal invasion in malignant thymoma. The authors analyzed the CT findings of 10 histologically-proven thymic masses from 1983 to 1990 in Yeungnam University Hospital. There were 10 cases of thymic masses in the anterior mediastinum consisting of 6 benign, 3 invasive thymomas, and one thymolipoma, while myasthenia gravis was associated with 2 cases of benign thymomas and with one case of invasive thymomas. The CT findings of the benign thymomas (6 cases) were well-defined, bordered, round-or oval-shaped masses with a well-preserved fat plane between the thymic mass and mediastinal great vessels, with no evidence of pleural implants and lung parenchymal invasion. The CT findings of the invasive thymomas (3 cases) were irregular, marginated lobular masses with obliteration of the fat plane between the thymic mass and surrounding great vessels, with evidence of local invasion such as extension to A-P window and mass effect to bronchus. Irregular pleural thickening due to pleural metastasis, multiple metastatic lung parenchymal nodules, and multiple mediastinal lymph node enlargement were also seen in the invasive thymomas. One case of thymolipoma showed an approximately 20cm-size, well-defined fat density mass containing internal septations.

  17. Painful heel: MR imaging findings.

    Science.gov (United States)

    Narváez, J A; Narváez, J; Ortega, R; Aguilera, C; Sánchez, A; Andía, E

    2000-01-01

    Heel pain is a common and frequently disabling clinical complaint that may be caused by a broad spectrum of osseous or soft-tissue disorders. These 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 lesions (tendinitis, 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.

  18. 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

  19. 基于时隙质心流水印的匿名通信追踪技术%Interval Centroid Based Flow Watermarking Technique for Anonymous Communication Traceback

    Institute of Scientific and Technical Information of China (English)

    张璐; 罗军舟; 杨明; 何高峰

    2011-01-01

    spread spectrum flow marking model, this paper proposes a novel flow watermarking technique that adopts interval centroid as its watermark carrier, which is insensitive to different types of flows. The theoretical analysis and experimental results show that this flow watermarking technique is appropriate for both interactive and non-interactive traffic, and can resist most existing attacks against flow watermarking.

  20. [The chest CT findings and pathologic findings of pulmonary tuberculosis].

    Science.gov (United States)

    Ogata, Hideo

    2009-08-01

    The past research of the radiologic manifestations of pulmonary tuberculosis in Japan was based on morphological pathology of the untreated patient autopsy. I would like to show the chest CT scan of tuberculosis diseases with caseous granuloma at its exudative reaction, proliferative reaction, productive reaction, cirrhotic reaction until self cure. This progress reflects the normal cell mediated immunological responses. Also I would like to show the cavitation of granuloma, which results from liquefaction of caseous materials during the course and results in the formation of the source of infection. And finally I would like to show the morphological differences of acinous lesion, acino-nodular lesion and caseous lobular pneumonia. These differences reflect the amount of bacilli disseminated in the peripheral parts under the lobules. In this study, I do not show old age cases and HIV positive cases, who do not form typical granuloma due to the decreased cell mediated immnunity and whose X ray findings are atypical.

  1. 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.

  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. Stardust findings. Implications for panspermia

    CERN Document Server

    Vaidya, Pushkar Ganesh

    2009-01-01

    In January 2004, the Stardust spacecraft flew through the dust of comet 81P/Wild 2 and captured specks of the cometary dust. On analysis of the comet 81P/Wild 2 samples, it was found that they contain materials found in the coldest and hottest region of the early solar nebula, strongly suggesting 'mixing' on the grandest scale. Here it is suggested that if microorganisms were present in the early solar nebula, as required by the hypothesis of cometary panspermia, then in the light of the Stardust findings, life was already present in the very material that formed the planetary bodies.

  4. Imaging findings of Paragonimus westermani

    Directory of Open Access Journals (Sweden)

    Shambhu Kumar Sah

    2016-06-01

    Conclusions: The imaging findings of P. westermani is so diverse and non-specific due to its complex life cycle and several life stages during infestation of human; however, common features include nodule, GGO, worm cyst, migration track, pleural effusion, pleural thickening on chest CT scan; patchy low or mixed density lesions on brain CT scan; ring enhancing lesion on brain MRI scan; conglomerated small cystic or serpentine lesions and migration track in liver and spleen on abdominal CT scan. The characteristic imaging features of paragonimiasis are worm cyst and migration track.

  5. Lithium nephropathy: unique sonographic findings.

    Science.gov (United States)

    Di Salvo, Donald N; Park, Joseph; Laing, Faye C

    2012-04-01

    This case series describes a unique sonographic appearance consisting of numerous microcysts and punctate echogenic foci seen on renal sonograms of 10 adult patients receiving chronic lithium therapy. Clinically, chronic renal insufficiency was present in 6 and nephrogenic diabetes insipidus in 2. Sonography showed numerous microcysts and punctate echogenic foci. Computed tomography in 5 patients confirmed microcysts and microcalcifications, which were fewer in number than on sonography. Magnetic resonance imaging in 2 patients confirmed microcysts in each case. Renal biopsy in 1 patient showed chronic interstitial nephritis, microcysts, and tubular dilatation. The diagnosis of lithium nephropathy should be considered when sonography shows these findings.

  6. 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.

  7. Oral findings in Carpenter syndrome.

    Science.gov (United States)

    Blankenstein, R; Brook, A H; Smith, R N; Patrick, D; Russell, J M

    2001-09-01

    Acrocephalopolysyndactyly Type II (Carpenter Syndrome) is determined by autosomal recessive inheritance. Only some 40 cases have been described. Variable clinical signs have been described including prolonged retention of primary teeth and hypodontia. This paper describes the oral and dental findings in a family containing two affected brothers. The family pedigree is informative, as the mother has had children by three partners. The two affected individuals are full brothers. The first affected brother has delayed dental development, severe hypodontia and small tooth crown size. Mesio-distal and bucco-lingual dimensions were measured on the study models and compared with population data. The younger brother also has delayed dental development but only mild hypodontia. Their half sister has severe hypodontia but no signs of Carpenter Syndrome. This family study demonstrates two affected individuals with typical clinical features and a pedigree compatible with autosomal recessive inheritance. Small tooth crown size has been shown by standardized measurement and evidence advanced that hypodontia is not part of the syndrome but a coincidental finding which segregates independently. We have also shown that the marked delay in emergence of teeth is associated more with problems of tooth eruption, possibly related to the bony abnormalities, than to a generalized delay in dental development.

  8. Sonographic findings in Gouty Nephropathy

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Mi Young; Jeon, Woo Ki; Kim, Ho Kyun; Kim, Yong Soo; Han, Chang Yul; Kim, Young Tong; Han, Sung Tag; Lee, Yoon Woo [Inje University College of Medicine, Seoul (Korea, Republic of)

    1994-09-15

    Ultrasound(US) findings of hyperechoic renal medulla in gouty nephropathy were compared with clinical features such as serum uric acid level to evaluate its usefulness in determination of the treatment and prognosis. A retrospective review of US of 36 cases of qouty arthritis was classified into four groups according to the medullary echogenicity (O :normal, grade I: renal medulla as isoechoic as renal cortex, grade II; heterogeneous increased echogenicity of renal medulla than that of renal cortex, grade III: the echogenicity of all renal medulla higher than that of renal cortex with renal contour deformity) which were compared with the serum urate level and associated conditions. Nephrocalcinosis and nephrolithiasis were analyzed through the KUB and the RGB. The degree of hyperechoic renal medulla was related to the level of serum uric acid, and in group IV, six cases of obstructive uropathy (nephrocalcinosis and nephrolithiasis) showed deformed renal contour. Associated conditions such as hypertension, alcoholism, diabetes mellitus and drug abuse were distributed in relation to the degree of hyperechoic renal medullas. US findings of hyperechoic renal mebulla was related with uric acid level in gouty nephropathy and thus could be valuable for treatment decision and prediction of prognosis.

  9. Ultrasonographic findings of esophageal varices

    Energy Technology Data Exchange (ETDEWEB)

    Kang, Hyo Seouk; Seol, Byeong Ryong; Rha, Seung Woon [Shilla General Hospital, Seoul (Korea, Republic of)

    1999-05-01

    To demonstrate the clinical usefulness of ultrasonography for detecting esophageal varices. In 20 cases of esophaged varix, the authors analysed the transabdominal ultrasonographic findings of the esophagogastric junction and compared mural thickness, the anteroposterior diameter of the esophagus, and the echogenic nature of the esophageal mucosal layer with those of 78 normal patients. The anterior and posterior mural thickeness of normal esophagus was 2.2{+-}0.7 and 2.4{+-}0.8mm respectively, but for variceal esophagus, the corresponding readings were 5.9{+-}1.3 and 5.2{+-}1.3mm respectively. The anteroposterior diameter of normal esophagus was 7.9{+-}2.1mm and that of variceal esophagus was 14.0{+-}1.8mm. There was a stastically significant difference (p<0.01) in mural thickness and anteroposterior diameter of the esophagus between a normal and variceal patient with regard to change of echogenic nature at the esphagogastric junction. Normal esophageal mucosa showed a thin and uniform echogenic line, but for variceal mucosa, the echogenic pattern was irregular, tortuous and thick. The athors believe that transabdominal US is helpful for detecting esophageal varices in patients with liver cirrhosis and UGI bleeding. Important clinically useful sonographic findings in diagnosing esophageal varix are as follows:1) mural thickness more than 6mm; 2) anteroposterior diameter of the esophagus of more than 15mm;3) irregular, tortuous and thickened echogenic mucosa.

  10. Comparison of photopeak integration methods

    Science.gov (United States)

    Kennedy, G.

    1990-12-01

    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.

  11. Comparison of photopeak integration methods

    Energy Technology Data Exchange (ETDEWEB)

    Kennedy, G. (Ecole Polytechnique, Montreal, PQ (Canada). Energy Engineering Inst.)

    1990-12-20

    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 {sup 137}Cs source to produce a peak at 662 keV on a Compton background generated by a {sup 60}Co 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.).

  12. Imaging findings in pediatric adrenocortical carcinoma

    Energy Technology Data Exchange (ETDEWEB)

    Ribeiro, J. [International Outreach Program, St. Jude Children' s Research Hospital, Memphis, TN (United States); Department of Radiology, Instituto Materno Infantil de Pernambuco, Recife (Brazil); Ribeiro, R.C. [International Outreach Program, St. Jude Children' s Research Hospital, Memphis, TN (United States); Department of Hematology-Oncology, St. Jude Children' s Research Hospital, Memphis, Tennessee (United States); Department of Pediatrics, University of Tennessee-Memphis, Tennessee (United States); Fletcher, B.D. [International Outreach Program, St. Jude Children' s Research Hospital, Memphis, TN (United States); Department of Pediatrics, University of Tennessee-Memphis, Tennessee (United States); Department of Diagnostic Imaging, St. Jude Children' s Research Hospital, 332 N. Lauderdale St., Memphis, TN 38105 (United States); Department of Radiology, University of Tennessee-Memphis, TN (United States)

    2000-01-01

    Background. Adrenocortical carcinoma (ACC), a tumor that is rare among children, causes clinically evident hormonal disturbances. Imaging methods are used to stage disease and to plan surgical resection. Objective. To describe the findings of the various imaging methods used to evaluate ACC. Materials and methods. We reviewed the records of ten consecutive patients (mean age, 8.1 years) who presented from 1987 to 1998 with ACC. All patients underwent computed tomography (CT) scanning; five underwent magnetic resonance (MR) imaging; four underwent ultrasonography (US); and eight underwent radionuclide bone scans. Results. Seven patients presented with signs of hormonally functional tumors. Typical imaging findings consisted of a large, well-defined suprarenal tumor, containing calcifications (seven patients) with a thin capsule and central necrosis or hemorrhage (six patients). The inferior vena cava (IVC) was compressed by tumor in three patients, and ultrasonography demonstrated invasion of the IVC wall in one of these. Three patients' bone scans showed that the primary tumor took up radioactive tracer. Spread to lungs or liver or both was demonstrated in six patients. Conclusions. CT, US and MR imaging are effective methods of imaging the primary tumor. Chest CT and bone scintigraphy should be performed to detect metastases. The presence of a thin tumor capsule, a stellate central zone of necrosis, and evidence of hormonal function help distinguish ACC from neuroblastoma. (orig.)

  13. Cytological findings in scintigraphically nonfunctioning thyroid nodules

    Directory of Open Access Journals (Sweden)

    Radović Branislava

    2010-01-01

    Full Text Available Background/Aim. The major one among the procedures for evaluating changes in the thyroid nodules is fine needle aspiration biopsy (FNAB. Thyroid scintigraphy is commonly used in diagnostic algoritham of nodules. Less than 5% of examined nodules show to be malignant. Scintigraphically, nodules could be classified as functional and nonfunctional. It is estimated that the risk of malignacy in nonfunctional nodules ranges from 8% to 25% and more. Aspiration punction provides 100% specific and positive predictive value. The aim of the study was to establish the distribution of cytological findings in nonfunctioning thyroid nodules. Methods. The prospective study enrolled 112 patients, 104 women and 8 men, submitted to thyroid scintigraphy for known thyroid nodule disorder. Scintigraphy was performed about half an hour after iv administration of 74 MBq of sodium-pertehnetate. A pin hole collimator was used. Scintigrams were visually evaluated, and absence of radiopharmaceutic in a nodule was estimated as nonfunctional one. Such nodules were afterwards subjected to FNAB and material obtained was cytologically analyzed. Results. In our patients nonfunctioning nodules comprised tissue of colloid struma, thyroid cyst, regular thyroid tissue, follicular lesion, oxiphillic lesion, papillary carcinoma tissue and tissue of lymphocytic thyroiditis. The most frequent cytological finding were colloid cysts (52%. A total of 70% were female nodules. Five citological findings were histopathologically analyzed. Conclusion. Cytological finding of nonfunctional nodules determines of the decision on radical therapy, and our preliminary results imply the need of FNAB routine use in nuclear medicine practice.

  14. 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.

  15. 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…

  16. 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.

  17. MR findings of cyclosporine neurotoxicity

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Po Song; Ahn, Kook Jin; Ahn, Bo Young; Jung, Hae An; Kim, Hee Je; Lee, Jae Mun [The Catholic Univ. St Mary' s Hospital, Seoul (Korea, Republic of)

    1998-12-01

    To analyze the MR findings of cyclosporine-induced neurotoxicity in patients receiving high dose of cyclosporine and to suggest the possible pathogenetic mechanism. The cases of seven patients (2 males, 5 females;18-36 years old) who suffered seizures after receiving high-dose cyclosporine for bone marrow transplantation due to diseases such as aplastic anemia or leukemia were retrospectively reviewed. We evaluated the location and pattern of abnormal signal intensity seen on T2 weighted images, the presence of contrast enhancement, and the changes seen on follow-up MR performed at intervals of 12-30 days after initial MR in five of seven patients. We analyzed levels of blood cyclosporine and magnesium, and investigated the presence of hypertension at the sity of the seizure. Locations of the lesions were bilateral(n=3D5), unilateral(n=3D2), parietal(n=3D6), occipital(n=3D6), temporal(n=3D4), and in the frontal lobe(n=3D3). Frontal lesions showed high signal intensities in the borderline ischemic zone of the frontal lobe between the territory of the anterior and middle cerebral arteries. In six of the seven patients, cortical and subcortical areas including subcortical U-fibers were seen on T2-weighted images to be involved in the parietooccipital lobes. Only one of the seven showed high signal intensity in the left basal ganglia. All lesions showed high signal intensity on T2-weighted images, and iso to low signal intensity on T1-weighted. In five of seven patients there was no definite enhancement, but in the other two, enhancement was slight. In four of seven patients seizures occurred within high therapeutic ranges(250-450ng/ml), while others suffered such attacks at levels below the therapeutic range. After cyclospirine was administered at a reduced dosage or stopped, follow-up MR images showed the complete or near-total disappearance of the abnormal findings previously described. Only two patients had hypertension, and the others normotension. Five of the

  18. Milnacipran: recent findings in depression

    Directory of Open Access Journals (Sweden)

    Guest editors: Stuart Montgomery (London

    2010-08-01

    Full Text Available 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, FrancePage 9   Treatment of patients with comorbid depression and diabetes with metformin and milnacipran Peter Hofmann (Graz, AustriaPage 17  Antidepressant therapy with milnacipran and venlafaxine Lucilla Mansuy (Toulouse, FrancePage 23  Milnacipran: a unique antidepressant? Siegfried Kasper and Gerald Pail (Vienna, Austria This supplement is based on a symposium that took place at the 9th International Forum on Mood and Anxiety in Monte Carlo in November 2009 and is supported by an unconditional education grant from Pierre Fabre Médicament.

  19. Gene finding in novel genomes

    Directory of Open Access Journals (Sweden)

    Korf Ian

    2004-05-01

    Full Text Available Abstract Background Computational gene prediction continues to be an important problem, especially for genomes with little experimental data. Results I introduce the SNAP gene finder which has been designed to be easily adaptable to a variety of genomes. In novel genomes without an appropriate gene finder, I demonstrate that employing a foreign gene finder can produce highly inaccurate results, and that the most compatible parameters may not come from the nearest phylogenetic neighbor. I find that foreign gene finders are more usefully employed to bootstrap parameter estimation and that the resulting parameters can be highly accurate. Conclusion Since gene prediction is sensitive to species-specific parameters, every genome needs a dedicated gene finder.

  20. Magellan: Principal Venus science findings

    Science.gov (United States)

    Saunders, R. Stephen

    1993-01-01

    This is a brief summary of the science findings of the Magellan mission, principally based on data from the radar system. Future plans for Magellan include acquisition of high resolution gravity data from a nearly circular orbit and atmospheric drag and occultation experiments. The Magellan science results represent the combined effort of more than 100 Magellan investigators and their students and colleagues. More extensive discussions can be found in the August and October, 1992 issues of the Journal of Geophysical Research, Planets. The Magellan mission's scientific objectives were to provide a global characterization of landforms and tectonic features; to distinguish and understand impact processes; to define and explain erosion, deposition, and chemical processes; and to model the interior density distribution. All but the last objective, which requires new global gravity data, have been accomplished, or we have acquired the data that are required to accomplish them.