WorldWideScience

Sample records for multi-resolution phylogenetic shadowing

  1. Regulatory elements of the floral homeotic gene AGAMOUS identified by phylogenetic footprinting and shadowing.

    Energy Technology Data Exchange (ETDEWEB)

    Hong, R. L., Hamaguchi, L., Busch, M. A., and Weigel, D.

    2003-06-01

    OAK-B135 In Arabidopsis thaliana, cis-regulatory sequences of the floral homeotic gene AGAMOUS (AG) are located in the second intron. This 3 kb intron contains binding sites for two direct activators of AG, LEAFY (LFY) and WUSCHEL (WUS), along with other putative regulatory elements. We have used phylogenetic footprinting and the related technique of phylogenetic shadowing to identify putative cis-regulatory elements in this intron. Among 29 Brassicaceae, several other motifs, but not the LFY and WUS binding sites previously identified, are largely invariant. Using reporter gene analyses, we tested six of these motifs and found that they are all functionally important for activity of AG regulatory sequences in A. thaliana. Although there is little obvious sequence similarity outside the Brassicaceae, the intron from cucumber AG has at least partial activity in A. thaliana. Our studies underscore the value of the comparative approach as a tool that complements gene-by-gene promoter dissection, but also highlight that sequence-based studies alone are insufficient for a complete identification of cis-regulatory sites.

  2. Parallel Statistical Multi-resolution Estimation

    CERN Document Server

    Lebert, Jan; Hagemann, Johannes; Kramer, Stephan C

    2015-01-01

    We discuss several strategies to implement Dykstra's projection algorithm on NVIDIA's compute unified device architecture (CUDA). Dykstra's algorithm is the central step in and the computationally most expensive part of statistical multi-resolution methods. It projects a given vector onto the intersection of convex sets. Compared with a CPU implementation our CUDA implementation is one order of magnitude faster. For a further speed up and to reduce memory consumption we have developed a new variant, which we call incomplete Dykstra's algorithm. Implemented in CUDA it is one order of magnitude faster than the CUDA implementation of the standard Dykstra algorithm. As sample application we discuss using the incomplete Dykstra's algorithm as preprocessor for the recently developed super-resolution optical fluctuation imaging (SOFI) method (Dertinger et al. 2009). We show that statistical multi-resolution estimation can enhance the resolution improvement of the plain SOFI algorithm just as the Fourier-reweighting ...

  3. MULTI-RESOLUTION SEAMLESS IMAGE DATABASE

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    This paper presents the basic concepts and principles,data structure and high efficient spatial index for multi-resolution image database.The database is characterized by arrangement of multi-resource image data and seamless mosaic,distribution-based storage and management,integration with other spatial database software such as GeoStar and GeoGrid developed by Wuhan Technical University of Surveying and Mapping.

  4. Shadow art

    KAUST Repository

    Mitra, Niloy J.

    2009-01-01

    "To them, I said, the truth would be literally nothing but the shadows of the images." - Plato, The Republic Shadow art is a unique form of sculptural art where the 2D shadows cast by a 3D sculpture are essential for the artistic effect. We introduce computational tools for the creation of shadow art and propose a design process where the user can directly specify the desired shadows by providing a set of binary images and corresponding projection information. Since multiple shadow images often contradict each other, we present a geometric optimization that computes a 3D shadow volume whose shadows best approximate the provided input images. Our analysis shows that this optimization is essential for obtaining physically realizable 3D sculptures. The resulting shadow volume can then be modified with a set of interactive editing tools that automatically respect the often intricate shadow constraints. We demonstrate the potential of our system with a number of complex 3D shadow art sculptures that go beyond what is seen in contemporary art pieces. © 2009 ACM.

  5. Network coding for multi-resolution multicast

    DEFF Research Database (Denmark)

    2013-01-01

    A method, apparatus and computer program product for utilizing network coding for multi-resolution multicast is presented. A network source partitions source content into a base layer and one or more refinement layers. The network source receives a respective one or more push-back messages from one...... or more network destination receivers, the push-back messages identifying the one or more refinement layers suited for each one of the one or more network destination receivers. The network source computes a network code involving the base layer and the one or more refinement layers for at least one...... of the one or more network destination receivers, and transmits the network code to the one or more network destination receivers in accordance with the push-back messages....

  6. Multi-resolution optical 3D sensor

    Science.gov (United States)

    Kühmstedt, Peter; Heinze, Matthias; Schmidt, Ingo; Breitbarth, Martin; Notni, Gunther

    2007-06-01

    A new multi resolution self calibrating optical 3D measurement system using fringe projection technique named "kolibri FLEX multi" will be presented. It can be utilised to acquire the all around shape of small to medium objects, simultaneously. The basic measurement principle is the phasogrammetric approach /1,2,3/ in combination with the method of virtual landmarks for the merging of the 3D single views. The system consists in minimum of two fringe projection sensors. The sensors are mounted on a rotation stage illuminating the object from different directions. The measurement fields of the sensors can be chosen different, here as an example 40mm and 180mm in diameter. In the measurement the object can be scanned at the same time with these two resolutions. Using the method of virtual landmarks both point clouds are calculated within the same world coordinate system resulting in a common 3D-point cloud. The final point cloud includes the overview of the object with low point density (wide field) and a region with high point density (focussed view) at the same time. The advantage of the new method is the possibility to measure with different resolutions at the same object region without any mechanical changes in the system or data post processing. Typical parameters of the system are: the measurement time is 2min for 12 images and the measurement accuracy is below 3μm up to 10 μm. The flexibility makes the measurement system useful for a wide range of applications such as quality control, rapid prototyping, design and CAD/CAM which will be shown in the paper.

  7. Dostoevsky's Shadows

    Directory of Open Access Journals (Sweden)

    Ioana Cristina Nicolae

    2016-04-01

    Full Text Available In this paper, I bring to light Jung’s Shadow archetype in Dostoevsky’s works and also analyzes their implications in the structure of his characters. Taking into account that the Russian writer’s creation is vast, I shall select a limited number of his works, namely ‘The Possessed’; ‘Crime and Punishment’; ‘The Brothers Karamazov’; ‘Notes from Underground’ and ‘The Double’. We are all burdened with our Shadow and must strive to overcome it, but what happens if we fail or never even try to master it? Raskolnikov’s attempt to free himself from the chains of his Shadow was too late, he had already committed the murder, but not in vain, he succeeded in redeeming himself, and so his effort must be taken into account. This does not help him to avoid the punishment, but offers him a chance after serving it. On the other hand, Smerdyakov’s case is different: he made no attempt to overcome his Shadow, the only argument that he brought in his favor being that he acted fuelled by the desire of fulfilling his brother’s wish. It is clear that, he has no chance for a better future and the fault lies with him because he did not create that chance. Dostoevsky’s characters always seem to be ruled by a tragic destiny, an unlucky fate from which they cannot escape.

  8. MULTI-RESOLUTION LEAST SQUARES SUPPORT VECTOR MACHINES

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    The Least Squares Support Vector Machines (LS-SVM) is an improvement to the SVM.Combined the LS-SVM with the Multi-Resolution Analysis (MRA), this letter proposes the Multi-resolution LS-SVM (MLS-SVM). The proposed algorithm has the same theoretical framework as MRA but with better approximation ability. At a fixed scale MLS-SVM is a classical LS-SVM, but MLS-SVM can gradually approximate the target function at different scales. In experiments, the MLS-SVM is used for nonlinear system identification, and achieves better identification accuracy.

  9. Shadow Soldiering

    DEFF Research Database (Denmark)

    Mynster Christensen, Maya

    question the thesis pursues is how the processes of mobilisation connecting these constellations are facilitated, and how the constellations are constituted in the intersection between local and global formations. Shadow soldiering, it is argued, is not a phenomenon existing in parallel with......The thesis is an inquiry into what is at stake for a surplus population of militia soldiers in the aftermaths of the civil war in Sierra Leone. The analysis takes its point of departure in how militarised networks are transformed and gradualy morph into new constellations of soldiering. The central...

  10. A Multi Resolution Method for Detecting Defects in Fabric Images

    Directory of Open Access Journals (Sweden)

    Jianyun Ni

    2013-02-01

    Full Text Available This study proposes a novel technique for detecting defects in fabric image based on the features extracted using a new multi resolution analysis tool called Digital Curvelet Transform. The direction features of curvelet coefficients and texture features based on GLCM of curvelet coefficients act as the feature-sets for a k-nearest neighbor classifier. The validation tests on the developed algorithms were performed with images from TILDA’s Textile Texture Database. A comparative study between the GLCM-based, wavelet-based and the curvelet-based techniques has also been included. The high accuracy achieved by the proposed method suggests an efficient solution for fabric defect. Furthermore, the algorithm has good robustness to white noise. Note that, this study is the first documented attempt to explore the possibilities of a new multi resolution analysis tool called digital Curvelet Transform to address the problem of fabric defect.

  11. Sparse Representation through Multi-Resolution Transform for Image Coding

    OpenAIRE

    Dr. P. Arockia Jansi Rani

    2013-01-01

    Having a compact basis is useful both for compression and fordesigning efficient numerical algorithms. In this paper, a newimage coding scheme using a multi-resolution transform knownas Bandelet Transform that provides an optimally compact basisfor images by exploring their directional characteristics isproposed. As this process results in a sparse representation,Zero Vector Pruning is applied in-order to extract the non-zerocoefficients. Further the geometric interpixel redundanciespresent i...

  12. A Multi Resolution Method for Detecting Defects in Fabric Images

    OpenAIRE

    Jianyun Ni; Jing Luo; Zaiping Chen; Enzeng Dong

    2013-01-01

    This study proposes a novel technique for detecting defects in fabric image based on the features extracted using a new multi resolution analysis tool called Digital Curvelet Transform. The direction features of curvelet coefficients and texture features based on GLCM of curvelet coefficients act as the feature-sets for a k-nearest neighbor classifier. The validation tests on the developed algorithms were performed with images from TILDA’s Textile Texture Database. A comparative study between...

  13. Sparse PDF Volumes for Consistent Multi-Resolution Volume Rendering

    KAUST Repository

    Sicat, Ronell Barrera

    2014-12-31

    This paper presents a new multi-resolution volume representation called sparse pdf volumes, which enables consistent multi-resolution volume rendering based on probability density functions (pdfs) of voxel neighborhoods. These pdfs are defined in the 4D domain jointly comprising the 3D volume and its 1D intensity range. Crucially, the computation of sparse pdf volumes exploits data coherence in 4D, resulting in a sparse representation with surprisingly low storage requirements. At run time, we dynamically apply transfer functions to the pdfs using simple and fast convolutions. Whereas standard low-pass filtering and down-sampling incur visible differences between resolution levels, the use of pdfs facilitates consistent results independent of the resolution level used. We describe the efficient out-of-core computation of large-scale sparse pdf volumes, using a novel iterative simplification procedure of a mixture of 4D Gaussians. Finally, our data structure is optimized to facilitate interactive multi-resolution volume rendering on GPUs.

  14. Sparse PDF Volumes for Consistent Multi-Resolution Volume Rendering.

    Science.gov (United States)

    Sicat, Ronell; Krüger, Jens; Möller, Torsten; Hadwiger, Markus

    2014-12-01

    This paper presents a new multi-resolution volume representation called sparse pdf volumes, which enables consistent multi-resolution volume rendering based on probability density functions (pdfs) of voxel neighborhoods. These pdfs are defined in the 4D domain jointly comprising the 3D volume and its 1D intensity range. Crucially, the computation of sparse pdf volumes exploits data coherence in 4D, resulting in a sparse representation with surprisingly low storage requirements. At run time, we dynamically apply transfer functions to the pdfs using simple and fast convolutions. Whereas standard low-pass filtering and down-sampling incur visible differences between resolution levels, the use of pdfs facilitates consistent results independent of the resolution level used. We describe the efficient out-of-core computation of large-scale sparse pdf volumes, using a novel iterative simplification procedure of a mixture of 4D Gaussians. Finally, our data structure is optimized to facilitate interactive multi-resolution volume rendering on GPUs.

  15. Moving object detection method based on complementary multi resolution background models

    Institute of Scientific and Technical Information of China (English)

    屠礼芬; 仲思东; 彭祺

    2014-01-01

    A novel moving object detection method was proposed in order to adapt the difficulties caused by intermittent object motion, thermal and dynamic background sequences. Two groups of complementary Gaussian mixture models were used. The ghost and real static object could be classified by comparing the similarity of the edge images further. In each group, the multi resolution Gaussian mixture models were used and dual thresholds were applied in every resolution in order to get a complete object mask without much noise. The computational color model was also used to depress illustration variations and light shadows. The proposed method was verified by the public test sequences provided by the IEEE Change Detection Workshop and compared with three state-of-the-art methods. Experimental results demonstrate that the proposed method is better than others for all of the evaluation parameters in intermittent object motion sequences. Four and two in the seven evaluation parameters are better than the others in thermal and dynamic background sequences, respectively. The proposed method shows a relatively good performance, especially for the intermittent object motion sequences.

  16. A Global, Multi-Resolution Approach to Regional Ocean Modeling

    Energy Technology Data Exchange (ETDEWEB)

    Du, Qiang

    2013-11-08

    In this collaborative research project between Pennsylvania State University, Colorado State University and Florida State University, we mainly focused on developing multi-resolution algorithms which are suitable to regional ocean modeling. We developed hybrid implicit and explicit adaptive multirate time integration method to solve systems of time-dependent equations that present two signi cantly di erent scales. We studied the e ects of spatial simplicial meshes on the stability and the conditioning of fully discrete approximations. We also studies adaptive nite element method (AFEM) based upon the Centroidal Voronoi Tessellation (CVT) and superconvergent gradient recovery. Some of these techniques are now being used by geoscientists(such as those at LANL).

  17. Application of multi-resolution analysis in sonar image denoising

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    Sonar images have complex background, low contrast, and deteriorative edges; these characteristics make it difficult for researchers to dispose the sonar objects. The multi-resolution analysis represents the signals in different scales efficiently, which is widely used in image processing. Wavelets are successful in disposing point discontinuities in one dimension, but not in two dimensions. The finite Ridgelet transform (FRIT) deals efficiently with the singularity in high dimension. It presents three improved denoising approaches, which are based on FRIT and used in the sonar image disposal technique. By experiment and comparison with traditional methods, these approaches not only suppress the artifacts, but also obtain good effect in edge keeping and SNR of the sonar image denoising.

  18. Automatic target tracking on multi-resolution terrain

    Institute of Scientific and Technical Information of China (English)

    WAN Ming; ZHANG Wei; MURRAY Marie O.; KAUFMAN Arie

    2006-01-01

    We propose a high-performance path planning algorithm for automatic target tracking in the applications of real-time simulation and visualization of large-scale terrain datasets, with a large number of moving objects (such as vehicles) tracking multiple moving targets. By using a modified Dijkstra's algorithm, an optimal path between each vehicle-target pair over a weighted grid-presented terrain is computed and updated to eliminate the problem of local minima and losing of tracking. Then, a dynamic path re-planning strategy using multi-resolution representation of a dynamic updating region is proposed to achieve high-performance by trading-off precision for efficiency, while guaranteeing accuracy. Primary experimental results showed that our algorithm successfully achieved 10 to 96 frames per second interactive path-replanning rates during a terrain simulation scenario with 10 to 100 vehicles and multiple moving targets.

  19. Multi-resolution image segmentation based on Gaussian mixture model

    Institute of Scientific and Technical Information of China (English)

    Tang Yinggan; Liu Dong; Guan Xinping

    2006-01-01

    Mixture model based image segmentation method, which assumes that image pixels are independent and do not consider the position relationship between pixels, is not robust to noise and usually leads to misclassification. A new segmentation method, called multi-resolution Gaussian mixture model method, is proposed. First, an image pyramid is constructed and son-father link relationship is built between each level of pyramid. Then the mixture model segmentation method is applied to the top level. The segmentation result on the top level is passed top-down to the bottom level according to the son-father link relationship between levels. The proposed method considers not only local but also global information of image, it overcomes the effect of noise and can obtain better segmentation result. Experimental result demonstrates its effectiveness.

  20. High-quality multi-resolution volume rendering in medicine

    Institute of Scientific and Technical Information of China (English)

    XIE Kai; YANG Jie; LI Xiao-liang

    2007-01-01

    In order to perform a high-quality interactive rendering of large medical data sets on a single off-theshelf PC, a LOD selection algorithm for multi-resolution volume rendering using 3D texture mapping is presented, which uses an adaptive scheme that renders the volume in a region-of-interest at a high resolution and the volume away from this region at lower resolutions. The algorithm is based on several important criteria, and rendering is done adaptively by selecting high-resolution cells close to a center of attention and low-resolution cells away from this area. In addition, our hierarchical level-of-detail representation guarantees consistent interpolation between different resolution levels. Experiments have been applied to a number of large medical data and have produced high quality images at interactive frame rates using standard PC hardware.

  1. Adaptive Covariance Inflation in a Multi-Resolution Assimilation Scheme

    Science.gov (United States)

    Hickmann, K. S.; Godinez, H. C.

    2015-12-01

    When forecasts are performed using modern data assimilation methods observation and model error can be scaledependent. During data assimilation the blending of error across scales can result in model divergence since largeerrors at one scale can be propagated across scales during the analysis step. Wavelet based multi-resolution analysiscan be used to separate scales in model and observations during the application of an ensemble Kalman filter. However,this separation is done at the cost of implementing an ensemble Kalman filter at each scale. This presents problemswhen tuning the covariance inflation parameter at each scale. We present a method to adaptively tune a scale dependentcovariance inflation vector based on balancing the covariance of the innovation and the covariance of observations ofthe ensemble. Our methods are demonstrated on a one dimensional Kuramoto-Sivashinsky (K-S) model known todemonstrate non-linear interactions between scales.

  2. Real-time shadows

    CERN Document Server

    Eisemann, Elmar; Assarsson, Ulf; Wimmer, Michael

    2011-01-01

    Important elements of games, movies, and other computer-generated content, shadows are crucial for enhancing realism and providing important visual cues. In recent years, there have been notable improvements in visual quality and speed, making high-quality realistic real-time shadows a reachable goal. Real-Time Shadows is a comprehensive guide to the theory and practice of real-time shadow techniques. It covers a large variety of different effects, including hard, soft, volumetric, and semi-transparent shadows.The book explains the basics as well as many advanced aspects related to the domain

  3. Study of hierarchical federation architecture using multi-resolution modeling

    Institute of Scientific and Technical Information of China (English)

    HAO Yan-ling; SHEN Dong-hui; QIAN Hua-ming; DENG Ming-hui

    2004-01-01

    This paper aims at finding a solution to the problem aroused in complex system simulation, where a specific functional federation is coupled with other simulation systems. In other words, the communication information within the system may be received by other federates that participated in this united simulation. For the purpose of ensuring simulation system unitary character, a hierarchical federation architecture (HFA) is taken. Also considering the real situation, where federates in a complicated simulation system can be made simpler to an extent, a multi-resolution modeling (MRM) method is imported to implement the design of hierarchical federation. By utilizing the multiple resolution entity (MRE) modeling approach, MRE for federates are designed out. When different level training simulation is required, the appropriate MRE at corresponding layers can be called. The design method realizes the reuse feature of the simulation system and reduces simulation complexity and improves the validity of system Simulation Cost (SC). Taking submarine voyage training simulator (SVTS) for instance, a HFA for submarine is constructed inthis paper, which approves the feasibility of studied approach.

  4. Face recognition with multi-resolution spectral feature images.

    Directory of Open Access Journals (Sweden)

    Zhan-Li Sun

    Full Text Available The one-sample-per-person problem has become an active research topic for face recognition in recent years because of its challenges and significance for real-world applications. However, achieving relatively higher recognition accuracy is still a difficult problem due to, usually, too few training samples being available and variations of illumination and expression. To alleviate the negative effects caused by these unfavorable factors, in this paper we propose a more accurate spectral feature image-based 2DLDA (two-dimensional linear discriminant analysis ensemble algorithm for face recognition, with one sample image per person. In our algorithm, multi-resolution spectral feature images are constructed to represent the face images; this can greatly enlarge the training set. The proposed method is inspired by our finding that, among these spectral feature images, features extracted from some orientations and scales using 2DLDA are not sensitive to variations of illumination and expression. In order to maintain the positive characteristics of these filters and to make correct category assignments, the strategy of classifier committee learning (CCL is designed to combine the results obtained from different spectral feature images. Using the above strategies, the negative effects caused by those unfavorable factors can be alleviated efficiently in face recognition. Experimental results on the standard databases demonstrate the feasibility and efficiency of the proposed method.

  5. Face recognition with multi-resolution spectral feature images.

    Science.gov (United States)

    Sun, Zhan-Li; Lam, Kin-Man; Dong, Zhao-Yang; Wang, Han; Gao, Qing-Wei; Zheng, Chun-Hou

    2013-01-01

    The one-sample-per-person problem has become an active research topic for face recognition in recent years because of its challenges and significance for real-world applications. However, achieving relatively higher recognition accuracy is still a difficult problem due to, usually, too few training samples being available and variations of illumination and expression. To alleviate the negative effects caused by these unfavorable factors, in this paper we propose a more accurate spectral feature image-based 2DLDA (two-dimensional linear discriminant analysis) ensemble algorithm for face recognition, with one sample image per person. In our algorithm, multi-resolution spectral feature images are constructed to represent the face images; this can greatly enlarge the training set. The proposed method is inspired by our finding that, among these spectral feature images, features extracted from some orientations and scales using 2DLDA are not sensitive to variations of illumination and expression. In order to maintain the positive characteristics of these filters and to make correct category assignments, the strategy of classifier committee learning (CCL) is designed to combine the results obtained from different spectral feature images. Using the above strategies, the negative effects caused by those unfavorable factors can be alleviated efficiently in face recognition. Experimental results on the standard databases demonstrate the feasibility and efficiency of the proposed method.

  6. Eagle II: A prototype for multi-resolution combat modeling

    Energy Technology Data Exchange (ETDEWEB)

    Powell, D.R.; Hutchinson, J.L.

    1993-02-01

    Eagle 11 is a prototype analytic model derived from the integration of the low resolution Eagle model with the high resolution SIMNET model. This integration promises a new capability to allow for a more effective examination of proposed or existing combat systems that could not be easily evaluated using either Eagle or SIMNET alone. In essence, Eagle II becomes a multi-resolution combat model in which simulated combat units can exhibit both high and low fidelity behavior at different times during model execution. This capability allows a unit to behave in a highly manner only when required, thereby reducing the overall computational and manpower requirements for a given study. In this framework, the SIMNET portion enables a highly credible assessment of the performance of individual combat systems under consideration, encompassing both engineering performance and crew capabilities. However, when the assessment being conducted goes beyond system performance and extends to questions of force structure balance and sustainment, then SISMNET results can be used to ``calibrate`` the Eagle attrition process appropriate to the study at hand. Advancing technologies, changes in the world-wide threat, requirements for flexible response, declining defense budgets, and down-sizing of military forces motivate the development of manpower-efficient, low-cost, responsive tools for combat development studies. Eagle and SIMNET both serve as credible and useful tools. The integration of these two models promises enhanced capabilities to examine the broader, deeper, more complex battlefield of the future with higher fidelity, greater responsiveness and low overall cost.

  7. A fast multi-resolution approach to tomographic PIV

    Energy Technology Data Exchange (ETDEWEB)

    Discetti, Stefano; Astarita, Tommaso [University of Naples Federico II, Department of Aerospace Engineering (DIAS), Naples (Italy)

    2012-03-15

    Tomographic particle image velocimetry (Tomo-PIV) is a recently developed three-component, three-dimensional anemometric non-intrusive measurement technique, based on an optical tomographic reconstruction applied to simultaneously recorded images of the distribution of light intensity scattered by seeding particles immersed into the flow. Nowadays, the reconstruction process is carried out mainly by iterative algebraic reconstruction techniques, well suited to handle the problem of limited number of views, but computationally intensive and memory demanding. The adoption of the multiplicative algebraic reconstruction technique (MART) has become more and more accepted. In the present work, a novel multi-resolution approach is proposed, relying on the adoption of a coarser grid in the first step of the reconstruction to obtain a fast estimation of a reliable and accurate first guess. A performance assessment, carried out on three-dimensional computer-generated distributions of particles, shows a substantial acceleration of the reconstruction process for all the tested seeding densities with respect to the standard method based on 5 MART iterations; a relevant reduction in the memory storage is also achieved. Furthermore, a slight accuracy improvement is noticed. A modified version, improved by a multiplicative line of sight estimation of the first guess on the compressed configuration, is also tested, exhibiting a further remarkable decrease in both memory storage and computational effort, mostly at the lowest tested seeding densities, while retaining the same performances in terms of accuracy. (orig.)

  8. Shadowing and hyperbolicity

    CERN Document Server

    Pilyugin, Sergei Yu

    2017-01-01

    Focusing on the theory of shadowing of approximate trajectories (pseudotrajectories) of dynamical systems, this book surveys recent progress in establishing relations between shadowing and such basic notions from the classical theory of structural stability as hyperbolicity and transversality. Special attention is given to the study of "quantitative" shadowing properties, such as Lipschitz shadowing (it is shown that this property is equivalent to structural stability both for diffeomorphisms and smooth flows), and to the passage to robust shadowing (which is also equivalent to structural stability in the case of diffeomorphisms, while the situation becomes more complicated in the case of flows). Relations between the shadowing property of diffeomorphisms on their chain transitive sets and the hyperbolicity of such sets are also described. The book will allow young researchers in the field of dynamical systems to gain a better understanding of new ideas in the global qualitative theory. It will also be of int...

  9. Shadowing in dynamical systems

    CERN Document Server

    Pilyugin, Sergei Yu

    1999-01-01

    This book is an introduction to the theory of shadowing of approximate trajectories in dynamical systems by exact ones. This is the first book completely devoted to the theory of shadowing. It shows the importance of shadowing theory for both the qualitative theory of dynamical systems and the theory of numerical methods. Shadowing Methods allow us to estimate differences between exact and approximate solutions on infinite time intervals and to understand the influence of error terms. The book is intended for specialists in dynamical systems, for researchers and graduate students in the theory of numerical methods.

  10. Inverse periodic shadowing properties

    CERN Document Server

    Osipov, Alexey V

    2011-01-01

    We consider inverse periodic shadowing properties of discrete dynamical systems generated by diffeomorphisms of closed smooth manifolds. We show that the $C^1$-interior of the set of all diffeomorphisms having so-called inverse periodic shadowing property coincides with the set of $\\Omega$-stable diffeomorphisms. The equivalence of Lipschitz inverse periodic shadowing property and hyperbolicity of the closure of all periodic points is proved. Besides, we prove that the set of all diffeomorphisms that have Lipschitz inverse periodic shadowing property and whose periodic points are dense in the nonwandering set coincides with the set of Axiom A diffeomorphisms.

  11. Gas and Shadow Swing

    Science.gov (United States)

    Tsai, Chi-Hung; Lai, Mei-Yi; Liu, Che-Wei; Huang, Shiang-Yin; Lin, Che-Yu; Yeh, Jeng-Sheng

    In our digital art, we design a folding fan as an interactive magic device. You can use it to play with gas around the world of illusions. Although gas could not be seen in our real world, we still want to interact with it in our illusions by the element of bubble shadows. Opening and swinging the folding fan can blow the bubble shadows away; closing and swinging it can break bubbles. If the magic fan touches the shadow of gas, the bubble shadows will explode and release colorful particles to surround you. Those actions are controlled and located by our circuits with Arduino board.

  12. Shadows behind the computers

    CERN Multimedia

    CERN audiovisual service; Jacques Fichet

    2007-01-01

    EGEE organized a shadowing day to spur female students to take up careers in the IT field. Eleven female staff from CERN’s IT Department were kept under close surveillance last week, shadowed by female students from the Collège du Léman International School as part of the Enabling Grids for E-sciencE project Gender Action Plan.

  13. Multi-Resolution Land Characteristics/Monitoring Trends in Burn Severity 2001 - Radiance

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — Multi-Resolution Land Characteristics 2001 (MRLC 2001 Radiance) Terrain Corrected Dataset is a collection of Landsat 7 Enhanced Thematic Mapper Plus (ETM+) and...

  14. Multi-Resolution Land Characteristics/Monitoring Trends in Burn Severity 2001 - Reflectance

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — Multi-Resolution Characteristics 2001 AT-Sensor Reflectance Dataset is a second-generation federal consortium to create an updated pool of nation-wide Landsat...

  15. M3RSM: Many-to-Many Multi-Resolution Scan Matching

    Science.gov (United States)

    2015-05-01

    Hayward St, Ann Arbor MI ebolson@umich.edu Fig. 1. Multi-resolution image pyramid . A high resolution cost function (bottom) is successively reduced in...dimension forming an image pyramid . By constructing the pyramid carefully, alignment scores computed using low-resolution levels can be used to prune the...used a two-level multi-resolution scheme in which the two levels differed in resolution by a factor of 10 [12]. In this work, we generalize this to a

  16. A Multi-Resolution Data Structure for Two-Dimensional Morse Functions

    Energy Technology Data Exchange (ETDEWEB)

    Bremer, P-T; Edelsbrunner, H; Hamann, B; Pascucci, V

    2003-07-30

    The efficient construction of simplified models is a central problem in the field of visualization. We combine topological and geometric methods to construct a multi-resolution data structure for functions over two-dimensional domains. Starting with the Morse-Smale complex we build a hierarchy by progressively canceling critical points in pairs. The data structure supports mesh traversal operations similar to traditional multi-resolution representations.

  17. SEVERAL ELEMENTS OF THE MULTI-RESOLUTION WAVELET ANALYSIS. Part 1: BASICS OF THE WAVELETS AND THE MULTI-RESOLUTION WAVELET ANALYSIS

    Directory of Open Access Journals (Sweden)

    Akimov Pavel Alekseevich

    2012-10-01

    Full Text Available Part 1 of this paper represents an introduction into the multi-resolution wavelet analysis. The wavelet-based analysis is an exciting new problem-solving tool used by mathematicians, scientists and engineers. In the paper, the authors try to present the fundamental elements of the multi-resolution wavelet analysis in a way that is accessible to an engineer, a scientist and an applied mathematician both as a theoretical approach and as a potential practical method of solving problems (particularly, boundary problems of structural mechanics and mathematical physics. The main goal of the contemporary wavelet research is to generate a set of basic functions (or general expansion functions and transformations that will provide an informative, efficient and useful description of a function or a signal. Another central idea is that of multi-resolution whereby decomposition of a signal represents the resolution of the detail. The multi-resolution decomposition seems to separate components of a signal in a way that is superior to most other methods of analysis, processing or compression. Due to the ability of the discrete wavelet transformation technique to decompose a signal at different independent scaling levels and to do it in a very flexible way, wavelets can be named "the microscopes of mathematics". Indeed, the use of the wavelet analysis and wavelet transformations requires a new point of view and a new method of interpreting representations.

  18. Stochastic Shadowing and Stochastic Stability

    OpenAIRE

    Todorov, Dmitry

    2014-01-01

    The notion of stochastic shadowing property is introduced. Relations to stochastic stability and standard shadowing are studied. Using tent map as an example it is proved that, in contrast to what happens for standard shadowing, there are significantly non-uniformly hyperbolic systems that satisfy stochastic shadowing property.

  19. Multi-resolution representation of digital terrain models with terrain features preservation

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    multi-resolution TIN model is an important issue in the contexts of visu-alization,virtual reality (VR),and geographic information systems (GIS). This paper proposes a new method for constructing multi-resolution TIN models with multi-scale topographic features preservation. The proposed method is driven by a half-edge collapse operation in a greedy framework and employs a new quadric error metric to efficiently measure geometric errors. We define topographic features in a multi-scale manner using a center-surround operator on Gaussian-weighted mean curvatures. Experimental results demonstrate that the proposed method performs better than previous methods in terms of topographic features preservation,and is able to achieve multi-resolution TIN models with a higher accuracy.

  20. EFFECTIVE MULTI-RESOLUTION TRANSFORM IDENTIFICATION FOR CHARACTERIZATION AND CLASSIFICATION OF TEXTURE GROUPS

    Directory of Open Access Journals (Sweden)

    S. Arivazhagan

    2011-11-01

    Full Text Available Texture classification is important in applications of computer image analysis for characterization or classification of images based on local spatial variations of intensity or color. Texture can be defined as consisting of mutually related elements. This paper proposes an experimental approach for identification of suitable multi-resolution transform for characterization and classification of different texture groups based on statistical and co-occurrence features derived from multi-resolution transformed sub bands. The statistical and co-occurrence feature sets are extracted for various multi-resolution transforms such as Discrete Wavelet Transform (DWT, Stationary Wavelet Transform (SWT, Double Density Wavelet Transform (DDWT and Dual Tree Complex Wavelet Transform (DTCWT and then, the transform that maximizes the texture classification performance for the particular texture group is identified.

  1. Shadows behind the computers

    CERN Multimedia

    2007-01-01

    EGEE organized a shadowing day to spur female students to take up careers in the IT field. Eleven female staff from CERN’s IT Department were kept under close surveillance last week, shadowed by female students from the Collège du Léman International School as part of the Enabling Grids for E-sciencE project Gender Action Plan. The shadowing day was aimed at inspiring young women to think of careers in information technology, by passing on the message that careers in science are open to both men and women and can be rewarding and fun. The students were given a tour of the ATLAS physics experiment and the CERN Computer Centre, as well as the opportunity for one-to-one interaction with CERN IT staff. Traditionally, fewer women work in the IT sector; women currently represent 21% of EGEE staff. The shadowing day was held as part of the EGEE Gender Action Plan, reflecting a commitment to reducing this gender gap. Other initiatives in...

  2. Large-Scale Multi-Resolution Representations for Accurate Interactive Image and Volume Operations

    KAUST Repository

    Sicat, Ronell B.

    2015-11-25

    The resolutions of acquired image and volume data are ever increasing. However, the resolutions of commodity display devices remain limited. This leads to an increasing gap between data and display resolutions. To bridge this gap, the standard approach is to employ output-sensitive operations on multi-resolution data representations. Output-sensitive operations facilitate interactive applications since their required computations are proportional only to the size of the data that is visible, i.e., the output, and not the full size of the input. Multi-resolution representations, such as image mipmaps, and volume octrees, are crucial in providing these operations direct access to any subset of the data at any resolution corresponding to the output. Despite its widespread use, this standard approach has some shortcomings in three important application areas, namely non-linear image operations, multi-resolution volume rendering, and large-scale image exploration. This dissertation presents new multi-resolution representations for large-scale images and volumes that address these shortcomings. Standard multi-resolution representations require low-pass pre-filtering for anti- aliasing. However, linear pre-filters do not commute with non-linear operations. This becomes problematic when applying non-linear operations directly to any coarse resolution levels in standard representations. Particularly, this leads to inaccurate output when applying non-linear image operations, e.g., color mapping and detail-aware filters, to multi-resolution images. Similarly, in multi-resolution volume rendering, this leads to inconsistency artifacts which manifest as erroneous differences in rendering outputs across resolution levels. To address these issues, we introduce the sparse pdf maps and sparse pdf volumes representations for large-scale images and volumes, respectively. These representations sparsely encode continuous probability density functions (pdfs) of multi-resolution pixel

  3. 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.

  4. Observe Your Shadow

    Science.gov (United States)

    Rovšek, Barbara

    2016-04-01

    Observe Your Shadow was the title of an observational experiment that was, among others, conducted in the scope of the past year's (2014-2015) first Slovene science competition for elementary school pupils between the ages of 6 and 13. The main reason for establishing a new science competition was popularization of science and its experimental methods, particularly among elementary school students. Elementary school teachers are not generally specialists in science, but rather have (and should have) extremely wide scopes of interests and competencies. By providing them with ideas and instructions for science experiments, we aim to enrich regular school lessons. In the first year alone, the competition took place in over half of Slovene elementary schools, with a total of 9000 participating students. In this paper we shall report about pupils' responses to tasks related to one of the experiments, namely, observation of their shadows on a sunny day.

  5. Forming Spirals From Shadows

    Science.gov (United States)

    Kohler, Susanna

    2016-07-01

    What causes the large-scale spiral structures found in some protoplanetary disks? Most models assume theyre created by newly-forming planets, but a new study suggests that planets might have nothing to do with it.Perturbations from Planets?In some transition disks protoplanetary disks with gaps in their inner regions weve directly imaged large-scale spiral arms. Many theories currently attribute the formation of these structures to young planets: either the direct perturbations of a planet embedded in the disk cause the spirals, or theyre indirectly caused by the orbit of a planetary body outside of the arms.Another example of spiral arms detected in a protoplanetary disk, MWC 758. [NASA/ESA/ESO/M. Benisty et al.]But what if you could get spirals without any planets? A team of scientists led by Matas Montesinos (University of Chile) have recently published a study in which they examine what happens to a shadowed protoplanetary disk.Casting Shadows with WarpsIn the teams setup, they envision a protoplanetary disk that is warped: the inner region is slightly tilted relative to the outer region. As the central star casts light out over its protoplanetary disk, this disk warping would cause some regions of the disk to be shaded in a way that isnt axially symmetric with potentially interesting implications.Montesinos and collaborators ran 2D hydrodynamics simulations to determine what happens to the motion of particles within the disk when they pass in and out of the shadowed regions. Since the shadowed regions are significantly colder than the illuminated disk, the pressure in these regions is much lower. Particles are therefore accelerated and decelerated as they pass through these regions, and the lack of axial symmetry causes spiral density waves to form in the disk as a result.Initial profile for the stellar heating rate per unit area for one of the authors simulations. The regions shadowed as a result of the disk warp subtend 0.5 radians each (shown on the left

  6. A robust and rapid algorithm for generating and transmitting multi-resolution three-dimensional models

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    Recent advances in 3D spatial data capture, such as high resolution satellite images and laser scanning as well as corresponding data processing and modeling technologies, have led to the generation of large amounts of datasets on terrains, buildings, roads and other features. The rapid transmission and visualization of 3D models has become a 'bottleneck' of internet-based applications. This paper proposes a robust algorithm to generate multi-resolution models for rapid visualization and network transmission of 3D models. Experiments were undertaken to evaluate the performance of the proposed algorithm. Experimental results demonstrate that the proposed algorithm achieves good performance in terms of running speed, accuracy, encoding of multi-resolution models, and network transmission.

  7. A high order multi-resolution solver for the Poisson equation with application to vortex methods

    DEFF Research Database (Denmark)

    Hejlesen, Mads Mølholm; Spietz, Henrik Juul; Walther, Jens Honore

    A high order method is presented for solving the Poisson equation subject to mixed free-space and periodic boundary conditions by using fast Fourier transforms (FFT). The high order convergence is achieved by deriving mollified Green’s functions from a high order regularization function which...... provides a correspondingly smooth solution to the Poisson equation.The high order regularization function may be obtained analogous to the approximate deconvolution method used in turbulence models and strongly relates to deblurring algorithms used in image processing. At first we show that the regularized...... by super-positioning an inter-mesh correction. For sufficiently smooth vector fields this multi-resolution correction can be achieved without the loss of convergence rate. An implementation of the multi-resolution solver in a two-dimensional re-meshed particle-mesh based vortex method is presented...

  8. Soft bilateral filtering volumetric shadows using cube shadow maps

    Science.gov (United States)

    Ali, Hatam H.; Sunar, Mohd Shahrizal; Kolivand, Hoshang

    2017-01-01

    Volumetric shadows often increase the realism of rendered scenes in computer graphics. Typical volumetric shadows techniques do not provide a smooth transition effect in real-time with conservation on crispness of boundaries. This research presents a new technique for generating high quality volumetric shadows by sampling and interpolation. Contrary to conventional ray marching method, which requires extensive time, this proposed technique adopts downsampling in calculating ray marching. Furthermore, light scattering is computed in High Dynamic Range buffer to generate tone mapping. The bilateral interpolation is used along a view rays to smooth transition of volumetric shadows with respect to preserving-edges. In addition, this technique applied a cube shadow map to create multiple shadows. The contribution of this technique isreducing the number of sample points in evaluating light scattering and then introducing bilateral interpolation to improve volumetric shadows. This contribution is done by removing the inherent deficiencies significantly in shadow maps. This technique allows obtaining soft marvelous volumetric shadows, having a good performance and high quality, which show its potential for interactive applications. PMID:28632740

  9. Multi Resolution Analysis (MRA of satellite images of oil spill disasters

    Directory of Open Access Journals (Sweden)

    Rashid Hussain

    2014-09-01

    Full Text Available Oil spill disasters monitoring and mitigation requires availability of state of the art applications and tools. Conventional technology gets benefit from latest trends and research in satellite imaginary. This research highlights multi-resolution wavelet analysis of satellite images of oil spill disasters. Multi-resolution analysis is one of the powerful techniques to analyze information content of images. This analysis enables us to have a scale-invariant interpretation of the image. At each resolution level, both smooth and detailed signals carry all the necessary information to reconstruct the smooth signal at the next level. The wavelet decomposition results in detail and approximate threshold coefficients. Multi resolution wavelet decomposition is used to analyze the image in both time and frequency domain. It provides better frequency resolution and poor time resolution for lower frequency; better time resolution and poor frequency resolution for higher frequency. This condition is fortunately suited for real applications; as signals have high frequency components for very short period of the interval and low frequency components for longer durations.

  10. The Optimazation of Multi Resolution Segmentation of Remotely Sensed Data Using Genetic Alghorithm

    Science.gov (United States)

    Saba, F.; Valadanzouj, M. J.; Mokhtarzade, M.

    2013-09-01

    Object oriented analysis is widely used in interpretation of remote sensing images in comparison with pixel based approaches. A key step for achieving an acceptable classification result is meaningful image segmentation. Multi resolution segmentation is known as one of the most popular approaches in image segmentation that have been implemented in commercial software on the market, eCognition. However, this algorithm needs a set of optimum parameters which usually obtained by trial and error task. This technique not only is tedious and time consuming, also rely on the user's experience. So In this study in order to alleviate this problem, genetic algorithm is proposed to find the optimal parameters for multi resolution segmentation by focusing on road feature. This method is implemented on a pan-sharpened IKONOS image covering a part of Shiraz city, Iran. The results show that, with parameters found by GA, multi resolution segmentation accuracy is higher than obtained accuracy with parameters found by user. The evaluation of results confirms the importance of genetic algorithm to get optimal parameters.

  11. Multi-resolution schemes for time scaled propagation of wave packets

    CERN Document Server

    Frapiccini, Ana Laura; Mota-Furtado, Francisca; O'Mahony, Patrick F; Piraux, Bernard

    2014-01-01

    We present a detailed analysis of the time scaled coordinate approach and its implementation for solving the time-dependent Schr\\"odinger equation describing the interaction of atoms or molecules with radiation pulses. We investigate and discuss the performance of multi-resolution schemes for the treatment of the squeezing around the origin of the bound part of the scaled wave packet. When the wave packet is expressed in terms of B-splines, we consider two different types of breakpoint sequences: an exponential sequence with a constant density and an initially uniform sequence with a density of points around the origin that increases with time. These two multi-resolution schemes are tested in the case of a one-dimensional gaussian potential and for atomic hydrogen. In the latter case, we also use Sturmian functions to describe the scaled wave packet and discuss a multi-resolution scheme which consists in working in a sturmian basis characterized by a set of non-linear parameters. Regarding the continuum part ...

  12. Multi Resolution AHB Bus Tracer with Real Time Compression for SOC

    Directory of Open Access Journals (Sweden)

    J. Jagadish Reddy

    2013-01-01

    Full Text Available AMBA (Advanced Microcontroller based Bus Architecture consists of AHB, APB, ASB and AXI. In this project we are Tracing AHB (Advanced High performance Bus signals with Real time Compression and Multi-resolution Techniques. A simple transaction on the AHB consists of an address phase and a subsequent data phase. Access to the target device is controlled through a MUX , thereby admitting bus-access to one bus-master at a time. In AHB Tracer we have to Trace Address signals, Data signals and Control signals, we have to compress them depending on AHB protocols. A multi-resolution AHB on-chip bus tracer is named as SYS_HMRBT (AHB Multi-resolution Bus Tracer and is used for monitoring. The goal is to provide better compression quality and multiple resolution traces to meet the complex SoC debugging needs. Compressing all signals at cycle-accurate-level does not always meet the debugging needs. As SOCs become more complex, the transaction level debugging becomes increasingly important, since it helps designers focus on the functional behaviors, instead of interpreting complex signals. By using this SYS_HMRBT, we can achieve 79%-96% of compression depending on selected resolution mode. Tools Used for this Project are Modelsim for Simulation, and Xilinx ISE II for Synthesis

  13. Shadows of WWII

    Directory of Open Access Journals (Sweden)

    Yumiko Sato

    2010-03-01

    Full Text Available On my initial visit with Shen I discovered that he grew up in China under the Japanese occupation during WWII. How would my nationality affect our therapeutic relationship? As a Japanese music therapist working at hospice in America the shadow of WWII is something I can not avoid. Neither can my patients. For those who lived through the war meeting someone from Japan could bring back powerful emotions, especially when theyre facing their final journeys. This is a story of patients for whom both music and my nationality opened the door to unexpected experiences. All identifying information has been changed to protect peoples confidentiality.

  14. Phylogenetic trees

    OpenAIRE

    Baños, Hector; Bushek, Nathaniel; Davidson, Ruth; Gross, Elizabeth; Harris, Pamela E.; Krone, Robert; Long, Colby; Stewart, Allen; WALKER, Robert

    2016-01-01

    We introduce the package PhylogeneticTrees for Macaulay2 which allows users to compute phylogenetic invariants for group-based tree models. We provide some background information on phylogenetic algebraic geometry and show how the package PhylogeneticTrees can be used to calculate a generating set for a phylogenetic ideal as well as a lower bound for its dimension. Finally, we show how methods within the package can be used to compute a generating set for the join of any two ideals.

  15. Is shadow banking really banking?

    OpenAIRE

    Bryan J. Noeth; Rajdeep Sengupta

    2011-01-01

    To those who don't know, the term "shadow banking" probably has a negative connotation. This primer draws parallels between what has been termed the shadow banking sector and the traditional banking sector—showing that they are similar in many ways.

  16. eShadow: A tool for comparing closely related sequences

    Energy Technology Data Exchange (ETDEWEB)

    Ovcharenko, Ivan; Boffelli, Dario; Loots, Gabriela G.

    2004-01-15

    Primate sequence comparisons are difficult to interpret due to the high degree of sequence similarity shared between such closely related species. Recently, a novel method, phylogenetic shadowing, has been pioneered for predicting functional elements in the human genome through the analysis of multiple primate sequence alignments. We have expanded this theoretical approach to create a computational tool, eShadow, for the identification of elements under selective pressure in multiple sequence alignments of closely related genomes, such as in comparisons of human to primate or mouse to rat DNA. This tool integrates two different statistical methods and allows for the dynamic visualization of the resulting conservation profile. eShadow also includes a versatile optimization module capable of training the underlying Hidden Markov Model to differentially predict functional sequences. This module grants the tool high flexibility in the analysis of multiple sequence alignments and in comparing sequences with different divergence rates. Here, we describe the eShadow comparative tool and its potential uses for analyzing both multiple nucleotide and protein alignments to predict putative functional elements. The eShadow tool is publicly available at http://eshadow.dcode.org/

  17. A morphologically preserved multi-resolution TIN surface modeling and visualization method for virtual globes

    Science.gov (United States)

    Zheng, Xianwei; Xiong, Hanjiang; Gong, Jianya; Yue, Linwei

    2017-07-01

    Virtual globes play an important role in representing three-dimensional models of the Earth. To extend the functioning of a virtual globe beyond that of a ;geobrowser;, the accuracy of the geospatial data in the processing and representation should be of special concern for the scientific analysis and evaluation. In this study, we propose a method for the processing of large-scale terrain data for virtual globe visualization and analysis. The proposed method aims to construct a morphologically preserved multi-resolution triangulated irregular network (TIN) pyramid for virtual globes to accurately represent the landscape surface and simultaneously satisfy the demands of applications at different scales. By introducing cartographic principles, the TIN model in each layer is controlled with a data quality standard to formulize its level of detail generation. A point-additive algorithm is used to iteratively construct the multi-resolution TIN pyramid. The extracted landscape features are also incorporated to constrain the TIN structure, thus preserving the basic morphological shapes of the terrain surface at different levels. During the iterative construction process, the TIN in each layer is seamlessly partitioned based on a virtual node structure, and tiled with a global quadtree structure. Finally, an adaptive tessellation approach is adopted to eliminate terrain cracks in the real-time out-of-core spherical terrain rendering. The experiments undertaken in this study confirmed that the proposed method performs well in multi-resolution terrain representation, and produces high-quality underlying data that satisfy the demands of scientific analysis and evaluation.

  18. Modified Multi-Resolution Telescopic Search Algorithm for Block-Matching Motion Estimation

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    This paper presents a modified multi-resolution telescopic search algorithm (MRTlcSA) for the blockmatching motion estimation. A novel inverse telescopic search is substituted for the conventional telescopic search, that reduces the on-chip memory size and memory bandwidth for VLSI implementation. In addition, strategies of motion track and adaptive search window are applied to reduce the computational complexity of motion estimation. Simulation results show that, compared with the MRTlcSA, the proposed algorithm reduces the computational load to only 30%while preserving almost the same image quality. Comparisons on hardware cost and power consumption of the VLSI implementations using the two algorithms are also presented in the paper.``

  19. A multi-resolution wavelet algorithm for hand vein pattern recognition

    Institute of Scientific and Technical Information of China (English)

    Yunxin Wang; Tiegen Liu; Junfeng Jiang

    2008-01-01

    A novel hand vein recognition algorithm is developed based on multi-resolution wavelet analysis. The texture feature of hand vein can be extracted by three-level wavelet decomposition. Furthermore, Knearest neighbor (KNN) with support vector machines (SVM) and minimum distance classifier (MDC) are employed for feature matching. Finally, the experiments are respectively performed in identification and verification modes using Tianjin University (TJU) hand vein image database constructed by our group.The results show the feasibility and effectiveness of the proposed method.

  20. Higher-order multi-resolution topology optimization using the finite cell method

    DEFF Research Database (Denmark)

    Groen, Jeroen Peter; Langelaar, Matthijs; Sigmund, Ole

    2017-01-01

    This article presents a detailed study on the potential and limitations of performing higher-order multi-resolution topology optimization with the finite cell method. To circumvent stiffness overestimation in high-contrast topologies, a length-scale is applied on the solution using filter methods....... The relations between stiffness overestimation, the analysis system, and the applied length-scale are examined, while a high-resolution topology is maintained. The computational cost associated with nested topology optimization is reduced significantly compared with the use of first-order finite elements...

  1. A Multi-Resolution Blending Considering Changed Regions for Orthoimage Mosaicking

    Directory of Open Access Journals (Sweden)

    Jun Pan

    2016-10-01

    Full Text Available Blending processing based on seamlines in image mosaicking is a procedure designed to obtain a smooth transition between images along seamlines and make seams invisible in the final mosaic. However, for high-resolution aerial orthoimages in urban areas, factors such as projection differences, moving objects, and radiometric differences in overlapping areas may result in ghosting and artifacts or visible shifts in the final mosaic. Such a mosaic is not a true reflection of the earth’s surface and may have a negative impact on image interpretation. Therefore, this paper presents a multi-resolution blending method considering changed regions to improve mosaic image quality. The method utilizes the region change rate (RCR to distinguish changed regions from unchanged regions in overlapping areas. The RCR of each region is computed using image segmentation and change detection methods. Then, a mask image is generated considering changed regions, and Gaussian and Laplacian pyramids are constructed. Finally, a multi-resolution reconstruction is performed to obtain the final mosaic. Experimental results from digital aerial orthoimages in urban areas are provided to verify this method for blending processing based on seamlines in mosaicking. Comparisons with other methods further demonstrate the potential of the presented method, as shown in a detailed comparison in three typical cases of the seamline passing by buildings, the seamline passing through buildings, and the seamline passing through areas with large radiometric differences.

  2. Multi-sensor image registration using multi-resolution shape analysis

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    Multi-sensor image registration has been widely used in remote sensing and medical image field, but registration performance is degenerated when heterogeneous images are involved. An image registration method based on multi-resolution shape analysis is proposed in this paper, to deal with the problem that the shape of similar objects is always invariant. The contours of shapes are first detected as visual features using an extended contour search algorithm in order to reduce effects of noise, and the multi-resolution shape descriptor is constructed through Fourier curvature representation of the contour's chain code. Then a minimum distance function is used to judge the similarity between two contours. To avoid the effect of different resolution and intensity distribution, suitable resolution of each image is selected by maximizing the consistency of its pyramid shapes. Finally,the transformation parameters are estimated based on the matched control-point pairs which are the centers of gravity of the closed contours. Multi-sensor Landsat TM imagery and infrared imagery have been used as experimental data for comparison with the classical contour-based registration. Our results have been shown to be superior to the classical ones.

  3. Developing a multiscale, multi-resolution agent-based brain tumor model by graphics processing units

    Directory of Open Access Journals (Sweden)

    Zhang Le

    2011-12-01

    Full Text Available Abstract Multiscale agent-based modeling (MABM has been widely used to simulate Glioblastoma Multiforme (GBM and its progression. At the intracellular level, the MABM approach employs a system of ordinary differential equations to describe quantitatively specific intracellular molecular pathways that determine phenotypic switches among cells (e.g. from migration to proliferation and vice versa. At the intercellular level, MABM describes cell-cell interactions by a discrete module. At the tissue level, partial differential equations are employed to model the diffusion of chemoattractants, which are the input factors of the intracellular molecular pathway. Moreover, multiscale analysis makes it possible to explore the molecules that play important roles in determining the cellular phenotypic switches that in turn drive the whole GBM expansion. However, owing to limited computational resources, MABM is currently a theoretical biological model that uses relatively coarse grids to simulate a few cancer cells in a small slice of brain cancer tissue. In order to improve this theoretical model to simulate and predict actual GBM cancer progression in real time, a graphics processing unit (GPU-based parallel computing algorithm was developed and combined with the multi-resolution design to speed up the MABM. The simulated results demonstrated that the GPU-based, multi-resolution and multiscale approach can accelerate the previous MABM around 30-fold with relatively fine grids in a large extracellular matrix. Therefore, the new model has great potential for simulating and predicting real-time GBM progression, if real experimental data are incorporated.

  4. A multi-resolution multi-size-windows disparity estimation approach

    Science.gov (United States)

    Martinez Bauza, Judit; Shiralkar, Manish

    2011-03-01

    This paper describes an algorithm for estimating the disparity between 2 images of a stereo pair. The disparity is related to the depth of the objects in the scene. Being able to obtain the depth of the objects in the scene is useful in many applications such as virtual reality, 3D user interfaces, background-foreground segmentation, or depth-image-based synthesis. This last application has motivated the proposed algorithm as part of a system that estimates disparities from a stereo pair and synthesizes new views. Synthesizing virtual views enables the post-processing of 3D content to adapt to user preferences or viewing conditions, as well as enabling the interface with multi-view auto-stereoscopic displays. The proposed algorithm has been designed to fulfill the following constraints: (a) low memory requirements, (b) local and parallelizable processing, and (c) adaptability to a sudden reduction in processing resources. Our solution uses a multi-resolution multi-size-windows approach, implemented as a line-independent process, well-suited for GPU implementation. The multi-resolution approach provides adaptability to sudden reduction in processing capabilities, besides computational advantages; the windows-based image processing algorithm guarantees low-memory requirements and local processing.

  5. a Virtual Globe-Based Multi-Resolution Tin Surface Modeling and Visualizetion Method

    Science.gov (United States)

    Zheng, Xianwei; Xiong, Hanjiang; Gong, Jianya; Yue, Linwei

    2016-06-01

    The integration and visualization of geospatial data on a virtual globe play an significant role in understanding and analysis of the Earth surface processes. However, the current virtual globes always sacrifice the accuracy to ensure the efficiency for global data processing and visualization, which devalue their functionality for scientific applications. In this article, we propose a high-accuracy multi-resolution TIN pyramid construction and visualization method for virtual globe. Firstly, we introduce the cartographic principles to formulize the level of detail (LOD) generation so that the TIN model in each layer is controlled with a data quality standard. A maximum z-tolerance algorithm is then used to iteratively construct the multi-resolution TIN pyramid. Moreover, the extracted landscape features are incorporated into each-layer TIN, thus preserving the topological structure of terrain surface at different levels. In the proposed framework, a virtual node (VN)-based approach is developed to seamlessly partition and discretize each triangulation layer into tiles, which can be organized and stored with a global quad-tree index. Finally, the real time out-of-core spherical terrain rendering is realized on a virtual globe system VirtualWorld1.0. The experimental results showed that the proposed method can achieve an high-fidelity terrain representation, while produce a high quality underlying data that satisfies the demand for scientific analysis.

  6. A VIRTUAL GLOBE-BASED MULTI-RESOLUTION TIN SURFACE MODELING AND VISUALIZETION METHOD

    Directory of Open Access Journals (Sweden)

    X. Zheng

    2016-06-01

    Full Text Available The integration and visualization of geospatial data on a virtual globe play an significant role in understanding and analysis of the Earth surface processes. However, the current virtual globes always sacrifice the accuracy to ensure the efficiency for global data processing and visualization, which devalue their functionality for scientific applications. In this article, we propose a high-accuracy multi-resolution TIN pyramid construction and visualization method for virtual globe. Firstly, we introduce the cartographic principles to formulize the level of detail (LOD generation so that the TIN model in each layer is controlled with a data quality standard. A maximum z-tolerance algorithm is then used to iteratively construct the multi-resolution TIN pyramid. Moreover, the extracted landscape features are incorporated into each-layer TIN, thus preserving the topological structure of terrain surface at different levels. In the proposed framework, a virtual node (VN-based approach is developed to seamlessly partition and discretize each triangulation layer into tiles, which can be organized and stored with a global quad-tree index. Finally, the real time out-of-core spherical terrain rendering is realized on a virtual globe system VirtualWorld1.0. The experimental results showed that the proposed method can achieve an high-fidelity terrain representation, while produce a high quality underlying data that satisfies the demand for scientific analysis.

  7. QRS detection by lifting scheme constructing multi-resolution morphological decomposition.

    Science.gov (United States)

    Zhang, Pu; Ma, Heather T; Zhang, Qinyu

    2014-01-01

    QRS complex detecting algorithm is core of ECG auto-diagnosis method and deeply influences cardiac cycle division for signal compression. However, ECG signals collected by noninvasive surface electrodes areusually mixed with several kinds of interference, and its waveform variation is the main reason for the hard realization of ECG processing. This paper proposes a QRS complex detecting algorithm based on multi-resolution mathematical morphological decomposition. This algorithm possesses superiorities in R peak detection of both mathematical morphological method and multi-resolution decomposition. Moreover, a lifting constructing method with Maximizationupdating operator is adopted to further improve the algorithm performance. And an efficient R peak search-back algorithm is employed to reduce the false positives (FP) and false negatives (FN). The proposed algorithm provides a good performance applying to MIT-BIH Arrhythmia Database, and achieves over 99% detection rate, sensitivity and positive predictivity, respectively, and calculation burden is low. Therefore, the proposed method is appropriate for portable medical devices in Telemedicine system.

  8. Multi-Resolution Multimedia QoE Models for IPTV Applications

    Directory of Open Access Journals (Sweden)

    Prasad Calyam

    2012-01-01

    Full Text Available Internet television (IPTV is rapidly gaining popularity and is being widely deployed in content delivery networks on the Internet. In order to proactively deliver optimum user quality of experience (QoE for IPTV, service providers need to identify network bottlenecks in real time. In this paper, we develop psycho-acoustic-visual models that can predict user QoE of multimedia applications in real time based on online network status measurements. Our models are neural network based and cater to multi-resolution IPTV applications that include QCIF, QVGA, SD, and HD resolutions encoded using popular audio and video codec combinations. On the network side, our models account for jitter and loss levels, as well as router queuing disciplines: packet-ordered and time-ordered FIFO. We evaluate the performance of our multi-resolution multimedia QoE models in terms of prediction characteristics, accuracy, speed, and consistency. Our evaluation results demonstrate that the models are pertinent for real-time QoE monitoring and resource adaptation in IPTV content delivery networks.

  9. Continuous wavelet transform and discrete multi-resolution analysis of surface fluxes and atmospheric stability

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    Variations of land surface fluxes of sensible heat (H), latent heat ( LE ), and CO2(F-CO2) obtained from the eddy-covariance measurements above a winter wheat field from March 30 to April 24, 2001 have been studied at scales ranging from 10 minutes to days. Wavelet transform is used in the analysis of land surface fluxes and atmospheric stability (ζ) calculated from the measurements to reveal the changes in land surface fluxes in hours to days scales. The main results are: (1) Concise and compact information about the fluxes, net radiation (Rn), temperature (T) and ζ in the scale-time domain are extracted from the data by continuous wavelet analysis,and 1 day, 0.5 day and short-period (shorter than 0.5 day) components are revealed. Continuous wavelet coefficients can be used to characterize periodic components of changes in fluxes and ζ. (2) Discrete-time multi-resolution analysis can be used to concentrate total energy variance of time series of the measurements to a small number of coefficients, plotting the relative energy distribution to get several meaningful characteristics of the data. (3) Under neutral atmospheric conditions, the relative energy distributions of the Haar multi-resolution analysis of the three non-dimensional coefficients (T/T* , q/q * and c/c * ) display clear similarities.

  10. A multi-resolution envelope-power based model for speech intelligibility.

    Science.gov (United States)

    Jørgensen, Søren; Ewert, Stephan D; Dau, Torsten

    2013-07-01

    The speech-based envelope power spectrum model (sEPSM) presented by Jørgensen and Dau [(2011). J. Acoust. Soc. Am. 130, 1475-1487] estimates the envelope power signal-to-noise ratio (SNRenv) after modulation-frequency selective processing. Changes in this metric were shown to account well for changes of speech intelligibility for normal-hearing listeners in conditions with additive stationary noise, reverberation, and nonlinear processing with spectral subtraction. In the latter condition, the standardized speech transmission index [(2003). IEC 60268-16] fails. However, the sEPSM is limited to conditions with stationary interferers, due to the long-term integration of the envelope power, and cannot account for increased intelligibility typically obtained with fluctuating maskers. Here, a multi-resolution version of the sEPSM is presented where the SNRenv is estimated in temporal segments with a modulation-filter dependent duration. The multi-resolution sEPSM is demonstrated to account for intelligibility obtained in conditions with stationary and fluctuating interferers, and noisy speech distorted by reverberation or spectral subtraction. The results support the hypothesis that the SNRenv is a powerful objective metric for speech intelligibility prediction.

  11. A. hexahedron element formulation with a new multi-resolution analysis

    CERN Document Server

    Xia, YiMing

    2014-01-01

    A multi-resolution hexahedron element and method is presented with a new multi-resolution analysis (MRA) framework. The MRA framework is formulated out of a mutually nesting displacement subspace sequence, whose basis functions are constructed of scaling and shifting on the element domain of a basic node shape function. The basic node shape function is constructed from extending to other seven quadrants around a specific node of a node isoparametric shape function. The MRA endows the proposed element with the resolution level (RL) to adjust the element node number, thus modulating structural analysis accuracy accordingly. As a result, the traditional 8-node hexahedron element and method is a mono-resolution one and also a special case of the proposed element and method. The accuracy of a structural analysis is actually determined by the RL, not by the mesh. The simplicity and clarity of shape function construction with the Kronecker delta property and the rational MRA enable the proposed element method to be ...

  12. The Moon's Phases and the Self Shadow

    Science.gov (United States)

    Young, Timothy; Guy, Mark

    2008-01-01

    In this article, the authors present a new way of teaching the phases of the Moon. Through the introduction of a "self shadow" (an idea of a shadow that is not well-known), they illuminate students' understanding of the phases of the Moon and help them understand the distinction between the shadows that cause eclipses and the shadows that relate…

  13. Out of shadow / Peeter Linnap

    Index Scriptorium Estoniae

    Linnap, Peeter, 1960-

    2007-01-01

    "Out of shadow" oli näitus Baltimaade 1990. aastate kunstist Ameerika publikule - sõnumiks iseseisvumisjärgsete aastate materiaalse, sotsiaalse ning vaimuelu peegeldused/tõlgendused visuaalses kunstis

  14. Out of shadow / Peeter Linnap

    Index Scriptorium Estoniae

    Linnap, Peeter, 1960-

    2007-01-01

    "Out of shadow" oli näitus Baltimaade 1990. aastate kunstist Ameerika publikule - sõnumiks iseseisvumisjärgsete aastate materiaalse, sotsiaalse ning vaimuelu peegeldused/tõlgendused visuaalses kunstis

  15. Adaptive multi-resolution 3D Hartree-Fock-Bogoliubov solver for nuclear structure

    Science.gov (United States)

    Pei, J. C.; Fann, G. I.; Harrison, R. J.; Nazarewicz, W.; Shi, Yue; Thornton, S.

    2014-08-01

    Background: Complex many-body systems, such as triaxial and reflection-asymmetric nuclei, weakly bound halo states, cluster configurations, nuclear fragments produced in heavy-ion fusion reactions, cold Fermi gases, and pasta phases in neutron star crust, are all characterized by large sizes and complex topologies in which many geometrical symmetries characteristic of ground-state configurations are broken. A tool of choice to study such complex forms of matter is an adaptive multi-resolution wavelet analysis. This method has generated much excitement since it provides a common framework linking many diversified methodologies across different fields, including signal processing, data compression, harmonic analysis and operator theory, fractals, and quantum field theory. Purpose: To describe complex superfluid many-fermion systems, we introduce an adaptive pseudospectral method for solving self-consistent equations of nuclear density functional theory in three dimensions, without symmetry restrictions. Methods: The numerical method is based on the multi-resolution and computational harmonic analysis techniques with a multi-wavelet basis. The application of state-of-the-art parallel programming techniques include sophisticated object-oriented templates which parse the high-level code into distributed parallel tasks with a multi-thread task queue scheduler for each multi-core node. The internode communications are asynchronous. The algorithm is variational and is capable of solving coupled complex-geometric systems of equations adaptively, with functional and boundary constraints, in a finite spatial domain of very large size, limited by existing parallel computer memory. For smooth functions, user-defined finite precision is guaranteed. Results: The new adaptive multi-resolution Hartree-Fock-Bogoliubov (HFB) solver madness-hfb is benchmarked against a two-dimensional coordinate-space solver hfb-ax that is based on the B-spline technique and a three-dimensional solver

  16. Efficient Multi-Resolution Compression Algorithm for Disk-Based Backup and Recovery

    Institute of Scientific and Technical Information of China (English)

    WANG Dejun; WANG Lina; WANG Hui

    2006-01-01

    In this paper, we deal with the problem of improving backup and recovery performance by compressing redundancies in large disk-based backup system. We analyze some general compression algorithms; evaluate their scalability and applicability. We investigate the distribution features of the redundant data in whole system range, and propose a multi-resolution distributed compression algorithm which can discern duplicated data at granularity of file level, block level or byte level to reduce the redundancy in backup environment. In order to accelerate recovery, we propose a synthetic backup solution which stores data in a recovery-oriented way and can compose the final data in back-end backup server. Experiments show that this algorithm can greatly reduce bandwidth consumption, save storage cost, and shorten the backup and recovery time. We implement these technologies in our product, called H-info backup system, which is capable of achieving over 10x compression ratio in both network utilization and data storage during backup.

  17. Sparse PDF maps for non-linear multi-resolution image operations

    KAUST Repository

    Hadwiger, Markus

    2012-11-01

    We introduce a new type of multi-resolution image pyramid for high-resolution images called sparse pdf maps (sPDF-maps). Each pyramid level consists of a sparse encoding of continuous probability density functions (pdfs) of pixel neighborhoods in the original image. The encoded pdfs enable the accurate computation of non-linear image operations directly in any pyramid level with proper pre-filtering for anti-aliasing, without accessing higher or lower resolutions. The sparsity of sPDF-maps makes them feasible for gigapixel images, while enabling direct evaluation of a variety of non-linear operators from the same representation. We illustrate this versatility for antialiased color mapping, O(n) local Laplacian filters, smoothed local histogram filters (e.g., median or mode filters), and bilateral filters. © 2012 ACM.

  18. A multi-resolution approach to heat kernels on discrete surfaces

    KAUST Repository

    Vaxman, Amir

    2010-07-26

    Studying the behavior of the heat diffusion process on a manifold is emerging as an important tool for analyzing the geometry of the manifold. Unfortunately, the high complexity of the computation of the heat kernel - the key to the diffusion process - limits this type of analysis to 3D models of modest resolution. We show how to use the unique properties of the heat kernel of a discrete two dimensional manifold to overcome these limitations. Combining a multi-resolution approach with a novel approximation method for the heat kernel at short times results in an efficient and robust algorithm for computing the heat kernels of detailed models. We show experimentally that our method can achieve good approximations in a fraction of the time required by traditional algorithms. Finally, we demonstrate how these heat kernels can be used to improve a diffusion-based feature extraction algorithm. © 2010 ACM.

  19. Analysis on electric energy measuring method based on multi-resolution analysis

    Institute of Scientific and Technical Information of China (English)

    ZHANG Xiao-bing; CUI Jia-rui; LIANG Yuan-hua; WANG Mu-kun

    2006-01-01

    Along with the massive applications of the non-linear loads and the impact loads, many non-stationary stochastic signals such as harmonics, inter-harmonics, impulse signals and so on are introduced into the electric network, and these non-stationary stochastic signals have had effects on the accuracy of the measurement of electric energy. The traditional method like Fourier Analysis can be applied efficiently on the stationary stochastic signals, but it has little effect on non-stationary stochastic signals. In light of this, the form of the signals of the electric network in wavelet domain will be discussed in this paper. A measurement method of active power based on multi-resolution analysis in the stochastic process is presented. This method has a wider application scope compared with the traditional method Fourier analysis, and it is of good referential value and practical value in terms of raising the level of the existing electric energy measurement.

  20. MULTI-RESOLUTION WAVELET ANALYSES OF TWO DIFFERENT PERFECTİONİSM SCALES: A UNIVERSITY SAMPLE

    Directory of Open Access Journals (Sweden)

    Y. KARACA

    2013-01-01

    Full Text Available Our prior studies indicated that statistical and wavelet analyses of perfectionism inventories were evaluated by SPSS and Wavelet packets. The main aim of the present study is to investigate different scale affects on perfectionism. We proposed that changes of low-frequency Meyer wavelets reflect students' perfectionism levels. We used Wavelet 1D and continuous 1D Wavelet analyses to measure their time dependence. We studied students' questionnaires. Multi-resolution analysis was obtained from continuous and discrete data as a function of cases at different scales. Large scale effects are assumed to play an important role on students with higher others-oriented perfectionism and adaptive perfectionism. Continuous wavelet 1D (Mexh analyses show the similar results and, large scale effects play an important role on students' behavior. In contrast, lower scale effects are assumed to play an important role on students with adaptive perfectionism and self-directed perfectionism

  1. Adaptive Multi-resolution 3D Hartree-Fock-Bogoliubov Solver for Nuclear Structure

    CERN Document Server

    Pei, Junchen; Harrison, Robert; Nazarewicz, Witold; Shi, Yue; Thornton, Scott

    2014-01-01

    Complex many-body systems, such as triaxial and reflection-asymmetric nuclei, weakly-bound halo states, cluster configurations, nuclear fragments produced in heavy-ion fusion reactions, cold Fermi gases, and pasta phases in neutron star crust, they are all characterized by large sizes and complex topologies, in which many geometrical symmetries characteristic of ground-state configurations are broken. A tool of choice to study such complex forms of matter is an adaptive multi-resolution wavelet analysis. This method has generated much excitement since it provides a common framework linking many diversified methodologies across different fields, including signal processing, data compression, harmonic analysis and operator theory, fractals, and quantum field theory. To describe complex superfluid many-fermion systems, we introduce an adaptive pseudo-spectral method for solving self-consistent equations of nuclear density functional theory in three dimensions, without symmetry restrictions. The new adaptive mult...

  2. Automatic multi-resolution image registration based on genetic algorithm and Hausdorff distance

    Institute of Scientific and Technical Information of China (English)

    Famao Ye; Lin Su; Shukai Li

    2006-01-01

    @@ Image registration is a crucial step in all image analysis tasks in which the final information is gained from the combination of various data sources, and it is difficult to automatically register due to the complexity of image. An approach based on genetic algorithm and Hausdorff distance to automatic image registration is presented. We use a multi-resolution edge tracker to find out the fine-quality edges and utilize the Hausdorff distance between the input image and the reference image as similarity measure. We use wavelet decomposition and genetic algorithm, which combine local search methods with global ones balancing exploration and exploitation, to speed up the search of the best transformation parameters.Experimental results show that the proposed approach is a promising method for registration of image.

  3. A multi-resolution envelope-power based model for speech intelligibility

    DEFF Research Database (Denmark)

    Jørgensen, Søren; Ewert, Stephan D.; Dau, Torsten

    2013-01-01

    The speech-based envelope power spectrum model (sEPSM) presented by Jørgensen and Dau [(2011). J. Acoust. Soc. Am. 130, 1475-1487] estimates the envelope power signal-to-noise ratio (SNRenv) after modulation-frequency selective processing. Changes in this metric were shown to account well...... for changes of speech intelligibility for normal-hearing listeners in conditions with additive stationary noise, reverberation, and nonlinear processing with spectral subtraction. In the latter condition, the standardized speech transmission index [(2003). IEC 60268-16] fails. However, the sEPSM is limited...... with a modulation-filter dependent duration. The multi-resolution sEPSM is demonstrated to account for intelligibility obtained in conditions with stationary and fluctuating interferers, and noisy speech distorted by reverberation or spectral subtraction. The results support the hypothesis that the SNRenv...

  4. Optimizing Energy and Modulation Selection in Multi-Resolution Modulation For Wireless Video Broadcast/Multicast

    KAUST Repository

    She, James

    2009-11-01

    Emerging technologies in Broadband Wireless Access (BWA) networks and video coding have enabled high-quality wireless video broadcast/multicast services in metropolitan areas. Joint source-channel coded wireless transmission, especially using hierarchical/superposition coded modulation at the channel, is recognized as an effective and scalable approach to increase the system scalability while tackling the multi-user channel diversity problem. The power allocation and modulation selection problem, however, is subject to a high computational complexity due to the nonlinear formulation and huge solution space. This paper introduces a dynamic programming framework with conditioned parsing, which significantly reduces the search space. The optimized result is further verified with experiments using real video content. The proposed approach effectively serves as a generalized and practical optimization framework that can gauge and optimize a scalable wireless video broadcast/multicast based on multi-resolution modulation in any BWA network.

  5. Accessing the Global Multi-Resolution Topography (GMRT) Synthesis through Gmrt Maptool

    Science.gov (United States)

    Ferrini, V. L.; Morton, J. J.; Barg, B.; Carbotte, S. M.

    2014-12-01

    The Global Multi-Resolution Topography (GMRT) Synthesis (http://gmrt.marine-geo.org) is a dynamically maintained global multi-resolution synthesis of terrestrial and seafloor elevation data maintained as both images and gridded data values as part of the IEDA Marine Geoscience Data System. GMRT seamlessly brings together a variety of elevation sources, and includes ship-based multibeam sonar collected throughout the global oceans that is processed by the GMRT Team and is gridded to 100-m resolution. New versions of GMRT are released twice each year, typically adding processed multibeam data from ~80 cruises per year. GMRT grids and images can be accessed through a variety of tools and interfaces including GeoMapApp (http://www.geomapapp.org) the GMRT MapTool (http://www.marine-geo.org/tools/maps_grids.php), and images can also be accessed through a Web Map Service. We have recently launched a new version of our web-based GMRT MapTool interface, which provides custom access to the gridded data values in standard formats including GeoTIFF, ArcASCII and GMT NetCDF. Several resolution options are provided for these gridded data, and corresponding images can also be generated. Coupled with this new interface is an XML metadata service that provides attribution information and detailed metadata about source data components (cruise metadata, sensor metadata, and full list of source data files) for any region of interest. Metadata from the attribution service is returned to the user along with the requested data, and is also combined with the data itself in new Bathymetry Attributed Grid (BAG) formatted files.

  6. Application of multi-resolution 3D techniques in crime scene documentation with bloodstain pattern analysis.

    Science.gov (United States)

    Hołowko, Elwira; Januszkiewicz, Kamil; Bolewicki, Paweł; Sitnik, Robert; Michoński, Jakub

    2016-10-01

    In forensic documentation with bloodstain pattern analysis (BPA) it is highly desirable to obtain non-invasively overall documentation of a crime scene, but also register in high resolution single evidence objects, like bloodstains. In this study, we propose a hierarchical 3D scanning platform designed according to the top-down approach known from the traditional forensic photography. The overall 3D model of a scene is obtained via integration of laser scans registered from different positions. Some parts of a scene being particularly interesting are documented using midrange scanner, and the smallest details are added in the highest resolution as close-up scans. The scanning devices are controlled using developed software equipped with advanced algorithms for point cloud processing. To verify the feasibility and effectiveness of multi-resolution 3D scanning in crime scene documentation, our platform was applied to document a murder scene simulated by the BPA experts from the Central Forensic Laboratory of the Police R&D, Warsaw, Poland. Applying the 3D scanning platform proved beneficial in the documentation of a crime scene combined with BPA. The multi-resolution 3D model enables virtual exploration of a scene in a three-dimensional environment, distance measurement, and gives a more realistic preservation of the evidences together with their surroundings. Moreover, high-resolution close-up scans aligned in a 3D model can be used to analyze bloodstains revealed at the crime scene. The result of BPA such as trajectories, and the area of origin are visualized and analyzed in an accurate model of a scene. At this stage, a simplified approach considering the trajectory of blood drop as a straight line is applied. Although the 3D scanning platform offers a new quality of crime scene documentation with BPA, some of the limitations of the technique are also mentioned.

  7. Testing the stress shadow hypothesis

    Science.gov (United States)

    Felzer, Karen R.; Brodsky, Emily E.

    2005-05-01

    A fundamental question in earthquake physics is whether aftershocks are predominantly triggered by static stress changes (permanent stress changes associated with fault displacement) or dynamic stresses (temporary stress changes associated with earthquake shaking). Both classes of models provide plausible explanations for earthquake triggering of aftershocks, but only the static stress model predicts stress shadows, or regions in which activity is decreased by a nearby earthquake. To test for whether a main shock has produced a stress shadow, we calculate time ratios, defined as the ratio of the time between the main shock and the first earthquake to follow it and the time between the last earthquake to precede the main shock and the first earthquake to follow it. A single value of the time ratio is calculated for each 10 × 10 km bin within 1.5 fault lengths of the main shock epicenter. Large values of the time ratio indicate a long wait for the first earthquake to follow the main shock and thus a potential stress shadow, whereas small values indicate the presence of aftershocks. Simulations indicate that the time ratio test should have sufficient sensitivity to detect stress shadows if they are produced in accordance with the rate and state friction model. We evaluate the 1989 MW 7.0 Loma Prieta, 1992 MW 7.3 Landers, 1994 MW 6.7 Northridge, and 1999 MW 7.1 Hector Mine main shocks. For each main shock, there is a pronounced concentration of small time ratios, indicating the presence of aftershocks, but the number of large time ratios is less than at other times in the catalog. This suggests that stress shadows are not present. By comparing our results to simulations we estimate that we can be at least 98% confident that the Loma Prieta and Landers main shocks did not produce stress shadows and 91% and 84% confident that stress shadows were not generated by the Hector Mine and Northridge main shocks, respectively. We also investigate the long hypothesized existence

  8. SHADOW: a new welding technique

    Science.gov (United States)

    Kramer, Thorsten; Olowinsky, Alexander M.; Durand, Friedrich

    2002-06-01

    The new welding technique 'SHADOW ' is introduced. SHADOW means the use of a single pulse to generate a quasi continuous weld of several millimeters in length. HET processing time is defined by the pulse duration of the pulsed laser. At present, a state-of-the-art laser is capable of a maximum pulse duration of 20 ms. The variation of the laser power depend on time is a vital capability of the pulsed laser to adapt the energy deposition into the workpiece. Laser beam welds of several watch components were successfully performed. Similar metals like crowns and axes made out of stainless steel have been welded using pulsed laser radiation. Applying a series of about 130 single pulses for the crown-axis combination the total energy accumulates to 19.5 J. The use of the SHADOW welding technique reduces the energy to 2.5 J. While welding dissimilar metals like stainless steel and bras, the SHADOW welding reduces drastically the contamination as well as the distortion. Laser beam welding of copper has a low process reliability due to the high reflection and the high thermal conductivity. SHADOW welds of 3.6 mm length were performed on 250 micrometers thick copper plates with very high reproducibility. As a result, a pilot plant for laser beam welding of copper plates has been set up. The work to be presented has partly been funded by the European Commission in a project under the contract BRPR-CT-0634.

  9. Shadow of a naked singularity

    Science.gov (United States)

    Ortiz, Néstor; Sarbach, Olivier; Zannias, Thomas

    2015-08-01

    We analyze the redshift suffered by photons originating from an external source, traversing a collapsing dust cloud, and finally being received by an asymptotic observer. In addition, we study the shadow that the collapsing cloud casts on the sky of the asymptotic observer. We find that the resulting redshift and properties of the shadow depend crucially on whether the final outcome of the complete gravitational collapse is a black hole or a naked singularity. In the black hole case, the shadow is due to the high redshift acquired by the photons as they approach the event horizon, implying that their energy is gradually redshifted toward zero within a few crossing times associated with the event horizon radius. In contrast to this, a naked singularity not only absorbs photons originating from the source, but it also emits infinitely redshifted photons with and without angular momenta. This emission introduces an abrupt cutoff in the frequency shift of the photons detected in directions close to the radial one, and it is responsible for the shadow masking the source in the naked singularity case. Furthermore, even though the shadow forms and begins to grow immediately after the observer crosses the Cauchy horizon, it takes many more crossing times than in the black hole case for the source to be occulted from the observer's eyes. We discuss possible implications of our results for testing the weak cosmic censorship hypothesis. Even though at late times the image of the source perceived by the observer looks the same in both cases, the dynamical formation of the shadow and the redshift images has distinct features and time scales in the black hole versus the naked singularity case. For stellar collapse, these time scales seem to be too short to be resolved with existing technology. However, our results may be relevant for the collapse of seeds leading to supermassive black holes.

  10. Multi-resolution statistical image reconstruction for mitigation of truncation effects: application to cone-beam CT of the head

    Science.gov (United States)

    Dang, Hao; Webster Stayman, J.; Sisniega, Alejandro; Zbijewski, Wojciech; Xu, Jennifer; Wang, Xiaohui; Foos, David H.; Aygun, Nafi; Koliatsos, Vassilis E.; Siewerdsen, Jeffrey H.

    2017-01-01

    A prototype cone-beam CT (CBCT) head scanner featuring model-based iterative reconstruction (MBIR) has been recently developed and demonstrated the potential for reliable detection of acute intracranial hemorrhage (ICH), which is vital to diagnosis of traumatic brain injury and hemorrhagic stroke. However, data truncation (e.g. due to the head holder) can result in artifacts that reduce image uniformity and challenge ICH detection. We propose a multi-resolution MBIR method with an extended reconstruction field of view (RFOV) to mitigate truncation effects in CBCT of the head. The image volume includes a fine voxel size in the (inner) nontruncated region and a coarse voxel size in the (outer) truncated region. This multi-resolution scheme allows extension of the RFOV to mitigate truncation effects while introducing minimal increase in computational complexity. The multi-resolution method was incorporated in a penalized weighted least-squares (PWLS) reconstruction framework previously developed for CBCT of the head. Experiments involving an anthropomorphic head phantom with truncation due to a carbon-fiber holder were shown to result in severe artifacts in conventional single-resolution PWLS, whereas extending the RFOV within the multi-resolution framework strongly reduced truncation artifacts. For the same extended RFOV, the multi-resolution approach reduced computation time compared to the single-resolution approach (viz. time reduced by 40.7%, 83.0%, and over 95% for an image volume of 6003, 8003, 10003 voxels). Algorithm parameters (e.g. regularization strength, the ratio of the fine and coarse voxel size, and RFOV size) were investigated to guide reliable parameter selection. The findings provide a promising method for truncation artifact reduction in CBCT and may be useful for other MBIR methods and applications for which truncation is a challenge.

  11. The shadow world of superstring theories

    Science.gov (United States)

    Kolb, E. W.; Turner, M. S.; Seckel, D.

    1985-01-01

    Some possible astrophysical and cosmological implications of 'shadow matter', a form of matter which only interacts gravitationally with ordinary matter and which may or may not be identical in its properties to ordinary matter, are considered. The possible existence, amount, and location of shadow matter in the solar system are discussed, and the significance of shadow matter for primordial nucleosynthesis, macroscopic asymmetry, baryogenesis, double-bubble inflation, and asymmetric microphysics is addressed. Massive shadow states are discussed.

  12. [Pellegrini-Stieda disease (shadow)].

    Science.gov (United States)

    Tkebuchava, G I

    1976-02-01

    The Pellegrini-Stied disease (shadow) (calcification periarthritis of the knee) is characterized by the presence of ossification of the medial condyl of the femur. The author's observations of 51 patients (sportsmen) suffering this lesion are described. The methods of conservative and operative treatment and the results obtained are reported.

  13. The Greatest Shadow on Earth

    Science.gov (United States)

    Hughes, Stephen; Wimmer, Jason; Towsey, Michael; Fahmi, Marco; Winslett, Greg; Dubler, Gabriel; Le Prou, Angela; Loose, David

    2014-01-01

    In a total solar eclipse, the Moon completely covers the Sun, casting a shadow several hundred km wide across the face of the Earth. This paper describes observations of the 14 November 2012 total eclipse of the Sun visible from north Queensland, Australia. The edge of the umbra was captured on video during totality, and this video is provided for…

  14. A spectrum of shadowed mirroring.

    Science.gov (United States)

    Wanamaker, Melissa C

    2012-04-01

    The central focus of this paper is to explore and extend Kohut's theory of maternal mirroring and to place it within the current context of psychoanalytic thinking. Kohut believed a child must experience "positive" mirroring from his or her mother in infancy and beyond to ensure development of a healthy self. Kohut alludes, however, to a possible situation in which the mother's face, metaphorically a mirror, can appear "faceless" to her child. From this I have inferred the concept of what I shall call "shadowed mirroring." Clinical and literary examples show that distorted, "shadowed" mirroring appears on a spectrum, with passive mirroring at one end and hostile (either verbal or nonverbal) mirroring on the other; some individuals experience both. I then consider how "shadowed mirroring," especially hostile mirroring, can be understood within the twin contexts of the overall mother-child relationship and present-day Intersubjective/Relational thinking that is both bidirectional and co-constructed. Shadowed mirroring can lead to severe personality dysfunction along the borderline-narcissistic range, as well as to difficulties in the areas of identity formation, failure of self-cohesiveness, and the blunting of certain humane qualities like empathy.

  15. Video Job Shadows. Project SEED.

    Science.gov (United States)

    Kucinkas, Gene; Noyce, Gary

    Video Job Shadows encourages students to develop questions about a job and offers them the chance to videotape a business person answering those questions about his or her job. The program can be an effective method of teaching high school students about the world of work and the specific requirements and responsibilities of some jobs in their…

  16. Gait identification from invisible shadows

    Science.gov (United States)

    Iwashita, Yumi; Uchino, Koji; Kurazume, Ryo; Stoica, Adrian

    2012-06-01

    This paper introduces a person identification system that uses as input the shadow images of a walking person, as projected by multiple lights(in this application invisible/infrared lights); the system uses a database of examples of shadows images of a number of people who walk. While it is accepted that personal identification has a higher correct classification rate if views from multiple cameras are used, most systems use only one camera, mainly because (i) Installation in real-world environments is easier, less cameras and no need to synchronize cameras, (ii) Computational cost is reduced. In the proposed system, we obtain the advantages of multiple viewpoints with a single camera and additional light sources. More specific, we install multiple infrared lights to project shadows of a subject on the ground and a camera with an infrared transmitting filter mounted in the ceiling inside of a building. Shadow areas, which are projections of one's body on the ground by multiple lights, can be considered as body areas captured from different viewpoints; thus, the proposed system is able to capture multiple projections of the body from a single camera. We explored in other papers the use of sunproduced shadow for identification of people walking freely in the outdoor. In this paper the application scenario is a system installed at the airport in the areas that precedes the immigration checkpoint. Japan already has health monitoring cameras focused on approaching individuals, to determine their health condition; the here described system would also be installed in such a controlled area with restricted walk corridors of walk and controlled lighting. Gait is a remote biometrics and can provide early warning; on another hand it can be used as corroborating evidence in a multi-modal biometrics system. A database of images including shadows for a set of 28 walking people was collected, and the features extracted from shadow areas by affine moment invariants, after which

  17. Object Oriented Shadow Detection and an Enhanced Method for Shadow Removal

    Directory of Open Access Journals (Sweden)

    Divya S Kumar

    2016-06-01

    Full Text Available Remote sensing technology derives information about the earth resources from satellite imagery. In urban areas, mainly the elevated objects are the reason for the appearance of shadows. Shadows are created as the light source has been blocked by something. Shadows lower the quality of images or it may affect the information provided by them. Thus for the correct image interpretation or to extract information it is important to detect shadow regions and restore them. Significant researches has been going on in finding the best shadow detection and removal methods. Many algorithms and methods had been developed so far. Most of them are based on pixel level shadow detection and removal. An object oriented shadow detection and removal resolves the shortcomings of pixel level detection. Existing object oriented method suffers from color casting of images even after the correction. A new method for shadow compensation by image inpainting resolves these color casting problem. Keywords- Shadow detection, shadow removal, Inpainting

  18. Multi-resolutional brain network filtering and analysis via wavelets on non-Euclidean space.

    Science.gov (United States)

    Kim, Won Hwa; Adluru, Nagesh; Chung, Moo K; Charchut, Sylvia; GadElkarim, Johnson J; Altshuler, Lori; Moody, Teena; Kumar, Anand; Singh, Vikas; Leow, Alex D

    2013-01-01

    Advances in resting state fMRI and diffusion weighted imaging (DWI) have led to much interest in studies that evaluate hypotheses focused on how brain connectivity networks show variations across clinically disparate groups. However, various sources of error (e.g., tractography errors, magnetic field distortion, and motion artifacts) leak into the data, and make downstream statistical analysis problematic. In small sample size studies, such noise have an unfortunate effect that the differential signal may not be identifiable and so the null hypothesis cannot be rejected. Traditionally, smoothing is often used to filter out noise. But the construction of convolving with a Gaussian kernel is not well understood on arbitrarily connected graphs. Furthermore, there are no direct analogues of scale-space theory for graphs--ones which allow to view the signal at multiple resolutions. We provide rigorous frameworks for performing 'multi-resolutional' analysis on brain connectivity graphs. These are based on the recent theory of non-Euclidean wavelets. We provide strong evidence, on brain connectivity data from a network analysis study (structural connectivity differences in adult euthymic bipolar subjects), that the proposed algorithm allows identifying statistically significant network variations, which are clinically meaningful, where classical statistical tests, if applied directly, fail.

  19. Multi-core/GPU accelerated multi-resolution simulations of compressible flows

    Science.gov (United States)

    Hejazialhosseini, Babak; Rossinelli, Diego; Koumoutsakos, Petros

    2010-11-01

    We develop a multi-resolution solver for single and multi-phase compressible flow simulations by coupling average interpolating wavelets and local time stepping schemes with high order finite volume schemes. Wavelets allow for high compression rates and explicit control over the error in adaptive representation of the flow field, but their efficient parallel implementation is hindered by the use of traditional data parallel models. In this work we demonstrate that this methodology can be implemented so that it can benefit from the processing power of emerging hybrid multicore and multi-GPU architectures. This is achieved by exploiting task-based parallelism paradigm and the concept of wavelet blocks combined with OpenCL and Intel Threading Building Blocks. The solver is able to handle high resolution jumps and benefits from adaptive time integration using local time stepping schemes as implemented on heterogeneous multi-core/GPU architectures. We demonstrate the accuracy of our method and the performance of our solver on different architectures for 2D simulations of shock-bubble interaction and Richtmeyer-Meshkov instability.

  20. A three-channel miniaturized optical system for multi-resolution imaging

    Science.gov (United States)

    Belay, Gebirie Y.; Ottevaere, Heidi; Meuret, Youri; Thienpont, Hugo

    2013-09-01

    Inspired by the natural compound eyes of insects, multichannel imaging systems embrace many channels that scramble their entire Field-Of-View (FOV). Our aim in this work was to attain multi-resolution capability into a multi-channel imaging system by manipulating the available channels to possess different imaging properties (focal length, angular resolution). We have designed a three-channel imaging system where the first and third channels have highest and lowest angular resolution of 0.0096° and 0.078° and narrowest and widest FOVs of 7° and 80°, respectively. The design of the channels has been done for a single wavelength of 587.6 nm using CODE V. The three channels each consist of 4 aspherical lens surfaces and an absorbing baffle that avoids crosstalk among the neighbouring channels. The aspherical lens surfaces have been fabricated in PMMA by ultra-precision diamond tooling and the baffles by metal additive manufacturing. The profiles of the fabricated lens surfaces have been measured with an accurate multi-sensor coordinate measuring machine and compared with the corresponding profiles of the designed lens surfaces. The fabricated lens profiles are then incorporated into CODE V to realistically model the three channels and also compare their performances with those of the nominal design. We can conclude that the performances of the two latter models are in a good agreement.

  1. Blind 3D Model Watermarking Based on Multi-Resolution Representation and Fuzzy Logic

    CERN Document Server

    Tamane, Sharvari C

    2012-01-01

    Insertion of a text message, audio data or/and an image into another image or 3D model is called as a watermarking process. Watermarking has variety of applications like: Copyright Protection, Owner Identification, Copy Protection and Data Hiding etc., depending upon the type of watermark insertion algorithm. Watermark remains in the content after applying various attacks without any distortions. The blind watermarking method used in the system is based on a wavelet transform, a fuzzy inference system and a multi-resolution representation (MRR) of the 3d model. The watermark scrambled by Arnold Transform is embedded in the wavelet coefficients at third resolution level of the MRR. Fuzzy logic approach used in the method makes it to approximate the best possible gain with an accurate scaling factor so that the watermark remains invisible. The fuzzy input variables are computed for each wavelet coefficient in the 3D model. The output of the fuzzy system is a single value which is a perceptual value for each cor...

  2. Uncertainty Quantification in Multi-Scale Coronary Simulations Using Multi-resolution Expansion

    Science.gov (United States)

    Tran, Justin; Schiavazzi, Daniele; Ramachandra, Abhay; Kahn, Andrew; Marsden, Alison

    2016-11-01

    Computational simulations of coronary flow can provide non-invasive information on hemodynamics that can aid in surgical planning and research on disease propagation. In this study, patient-specific geometries of the aorta and coronary arteries are constructed from CT imaging data and finite element flow simulations are carried out using the open source software SimVascular. Lumped parameter networks (LPN), consisting of circuit representations of vascular hemodynamics and coronary physiology, are used as coupled boundary conditions for the solver. The outputs of these simulations depend on a set of clinically-derived input parameters that define the geometry and boundary conditions, however their values are subjected to uncertainty. We quantify the effects of uncertainty from two sources: uncertainty in the material properties of the vessel wall and uncertainty in the lumped parameter models whose values are estimated by assimilating patient-specific clinical and literature data. We use a generalized multi-resolution chaos approach to propagate the uncertainty. The advantages of this approach lies in its ability to support inputs sampled from arbitrary distributions and its built-in adaptivity that efficiently approximates stochastic responses characterized by steep gradients.

  3. Multi-resolution voxel phantom modeling: a high-resolution eye model for computational dosimetry

    Science.gov (United States)

    Caracappa, Peter F.; Rhodes, Ashley; Fiedler, Derek

    2014-09-01

    Voxel models of the human body are commonly used for simulating radiation dose with a Monte Carlo radiation transport code. Due to memory limitations, the voxel resolution of these computational phantoms is typically too large to accurately represent the dimensions of small features such as the eye. Recently reduced recommended dose limits to the lens of the eye, which is a radiosensitive tissue with a significant concern for cataract formation, has lent increased importance to understanding the dose to this tissue. A high-resolution eye model is constructed using physiological data for the dimensions of radiosensitive tissues, and combined with an existing set of whole-body models to form a multi-resolution voxel phantom, which is used with the MCNPX code to calculate radiation dose from various exposure types. This phantom provides an accurate representation of the radiation transport through the structures of the eye. Two alternate methods of including a high-resolution eye model within an existing whole-body model are developed. The accuracy and performance of each method is compared against existing computational phantoms.

  4. Multi-resolution cell orientation congruence descriptors for epithelium segmentation in endometrial histology images.

    Science.gov (United States)

    Li, Guannan; Raza, Shan E Ahmed; Rajpoot, Nasir M

    2017-04-01

    It has been recently shown that recurrent miscarriage can be caused by abnormally high ratio of number of uterine natural killer (UNK) cells to the number of stromal cells in human female uterus lining. Due to high workload, the counting of UNK and stromal cells needs to be automated using computer algorithms. However, stromal cells are very similar in appearance to epithelial cells which must be excluded in the counting process. To exclude the epithelial cells from the counting process it is necessary to identify epithelial regions. There are two types of epithelial layers that can be encountered in the endometrium: luminal epithelium and glandular epithelium. To the best of our knowledge, there is no existing method that addresses the segmentation of both types of epithelium simultaneously in endometrial histology images. In this paper, we propose a multi-resolution Cell Orientation Congruence (COCo) descriptor which exploits the fact that neighbouring epithelial cells exhibit similarity in terms of their orientations. Our experimental results show that the proposed descriptors yield accurate results in simultaneously segmenting both luminal and glandular epithelium.

  5. Exposure Estimation from Multi-Resolution Optical Satellite Imagery for Seismic Risk Assessment

    Directory of Open Access Journals (Sweden)

    Jochen Zschau

    2012-05-01

    Full Text Available Given high urbanization rates and increasing spatio-temporal variability in many present-day cities, exposure information is often out-of-date, highly aggregated or spatially fragmented, increasing the uncertainties associated with seismic risk assessments. This work therefore aims at using space-based technologies to estimate, complement and extend exposure data at multiple scales, over large areas and at a comparatively low cost for the case of the city of Bishkek, Kyrgyzstan. At a neighborhood scale, an analysis of urban structures using medium-resolution optical satellite images is performed. Applying image classification and change-detection analysis to a time-series of Landsat images, the urban environment can be delineated into areas of relatively homogeneous urban structure types, which can provide a first estimate of an exposed building stock (e.g., approximate age of structures, composition and distribution of predominant building types. At a building-by-building scale, a more detailed analysis of the exposed building stock is carried out using a high-resolution Quickbird image. Furthermore, the multi-resolution datasets are combined with census data to disaggregate population statistics. The tools used within this study are being developed on a free- and open-source basis and aim at being transparent, usable and transferable.

  6. Statistical Projections for Multi-resolution, Multi-dimensional Visual Data Exploration and Analysis

    Energy Technology Data Exchange (ETDEWEB)

    Nguyen, Hoa T. [Univ. of Utah, Salt Lake City, UT (United States); Stone, Daithi [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Bethel, E. Wes [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)

    2016-01-01

    An ongoing challenge in visual exploration and analysis of large, multi-dimensional datasets is how to present useful, concise information to a user for some specific visualization tasks. Typical approaches to this problem have proposed either reduced-resolution versions of data, or projections of data, or both. These approaches still have some limitations such as consuming high computation or suffering from errors. In this work, we explore the use of a statistical metric as the basis for both projections and reduced-resolution versions of data, with a particular focus on preserving one key trait in data, namely variation. We use two different case studies to explore this idea, one that uses a synthetic dataset, and another that uses a large ensemble collection produced by an atmospheric modeling code to study long-term changes in global precipitation. The primary findings of our work are that in terms of preserving the variation signal inherent in data, that using a statistical measure more faithfully preserves this key characteristic across both multi-dimensional projections and multi-resolution representations than a methodology based upon averaging.

  7. Five Micron High Resolution MALDI Mass Spectrometry Imaging with Simple, Interchangeable, Multi-Resolution Optical System

    Science.gov (United States)

    Feenstra, Adam D.; Dueñas, Maria Emilia; Lee, Young Jin

    2017-01-01

    High-spatial resolution mass spectrometry imaging (MSI) is crucial for the mapping of chemical distributions at the cellular and subcellular level. In this work, we improved our previous laser optical system for matrix-assisted laser desorption ionization (MALDI)-MSI, from 9 μm practical laser spot size to a practical laser spot size of 4 μm, thereby allowing for 5 μm resolution imaging without oversampling. This is accomplished through a combination of spatial filtering, beam expansion, and reduction of the final focal length. Most importantly, the new laser optics system allows for simple modification of the spot size solely through the interchanging of the beam expander component. Using 10×, 5×, and no beam expander, we could routinely change between 4, 7, and 45 μm laser spot size, in less than 5 min. We applied this multi-resolution MALDI-MSI system to a single maize root tissue section with three different spatial resolutions of 5, 10, and 50 μm and compared the differences in imaging quality and signal sensitivity. We also demonstrated the difference in depth of focus between the optical systems with 10× and 5× beam expanders.

  8. Multi-resolution Statistical Analysis of Brain Connectivity Graphs in Preclinical Alzheimer's Disease

    Science.gov (United States)

    Kim, Won Hwa; Adluru, Nagesh; Chung, Moo K.; Okonkwo, Ozioma C.; Johnson, Sterling C.; Bendlin, Barbara; Singh, Vikas

    2015-01-01

    There is significant interest, both from basic and applied research perspectives, in understanding how structural/functional connectivity changes can explain behavioral symptoms and predict decline in neurodegenerative diseases such as Alzheimer's disease (AD). The first step in most such analyses is to encode the connectivity information as a graph; then, one may perform statistical inference on various ‘global’ graph theoretic summary measures (e.g., modularity, graph diameter) and/or at the level of individual edges (or connections). For AD in particular, clear differences in connectivity at the dementia stage of the disease (relative to healthy controls) have been identified. Despite such findings, AD-related connectivity changes in preclinical disease remain poorly characterized. Such preclinical datasets are typically smaller and group differences are weaker. In this paper, we propose a new multi-resolution method for performing statistical analysis of connectivity networks/graphs derived from neuroimaging data. At the high level, the method occupies the middle ground between the two contrasts — that is, to analyze global graph summary measures (global) or connectivity strengths or correlations for individual edges similar to voxel based analysis (local). Instead, our strategy derives a Wavelet representation at each primitive (connection edge) which captures the graph context at multiple resolutions. We provide extensive empirical evidence of how this framework offers improved statistical power by analyzing two distinct AD datasets. Here, connectivity is derived from diffusion tensor magnetic resonance images by running a tractography routine. We first present results showing significant connectivity differences between AD patients and controls that were not evident using standard approaches. Later, we show results on populations that are not diagnosed with AD but have a positive family history risk of AD where our algorithm helps in identifying

  9. Study of Least Squares Collocation and Multi-Resolution Representation for Regional Gravity Field Modelling

    Science.gov (United States)

    Willberg, Martin; Lieb, Verena; Pail, Roland; Schmidt, Michael

    2017-04-01

    The analysis of the Earth's gravity field plays an important role in various disciplines of geosciences. While modern satellite gravity missions make it possible to define a globally consistent geoid with centimeter accuracy and a spatial resolution of 80-100km, it stays a major challenge to consistently combine global low-resolution data with regional high-resolution gravity information. Therefore, a variety of different regional gravity field modelling methods have been established during the last decades. In our analysis, we investigate the spectral combination of heterogeneous gravity data within two different calculation methods: First, the statistical approach of Least Squares Collocation (LSC) which uses the covariance information of input and output data to result in a full variance-covariance matrix. Second, the Multi-Resolution Representation (MRR) based on spherical radial basis functions. The MRR combines a low-pass filtered global geopotential model with satellite gradiometer and/or terrestrial gravity data by means of band-pass filtering. We examine the theoretical concepts and the computational differences and similarities between both approaches. Through fast changing topography, mountains as well as oceanic regions, our study area in the South American Andes is challenging and perfectly suitable for this examination. The use of synthetic data in closed-loop tests enables us to a very detailed investigation of predicted and actual accuracies of geoid determination. Furthermore, we point out respective advantages and disadvantages and link them to the calculation concepts of the two methods. The results contribute to the project "Optimally combined regional geoid models for the realization of height systems in developing countries (ORG4heights)" and, thus, aim to finally integrate the regional solutions into a global vertical reference frame.

  10. Wormhole shadows in rotating dust

    Science.gov (United States)

    Ohgami, Takayuki; Sakai, Nobuyuki

    2016-09-01

    As an extension of our previous work, which investigated the shadows of the Ellis wormhole surrounded by nonrotating dust, in this paper we study wormhole shadows in a rotating dust flow. First, we derive steady-state solutions of slowly rotating dust surrounding the wormhole by solving relativistic Euler equations. Solving null geodesic equations and radiation transfer equations, we investigate the images of the wormhole surrounded by dust for the above steady-state solutions. Because the Ellis wormhole spacetime possesses unstable circular orbits of photons, a bright ring appears in the image, just as in Schwarzschild spacetime. The bright ring looks distorted due to rotation. Aside from the bright ring, there appear weakly luminous complex patterns by the emission from the other side of the throat. These structure could be detected by high-resolution very-long-baseline-interferometry observations in the near future.

  11. Shadow imaging of geosynchronous satellites

    Science.gov (United States)

    Douglas, Dennis Michael

    Geosynchronous (GEO) satellites are essential for modern communication networks. If communication to a GEO satellite is lost and a malfunction occurs upon orbit insertion such as a solar panel not deploying there is no direct way to observe it from Earth. Due to the GEO orbit distance of ~36,000 km from Earth's surface, the Rayleigh criteria dictates that a 14 m telescope is required to conventionally image a satellite with spatial resolution down to 1 m using visible light. Furthermore, a telescope larger than 30 m is required under ideal conditions to obtain spatial resolution down to 0.4 m. This dissertation evaluates a method for obtaining high spatial resolution images of GEO satellites from an Earth based system by measuring the irradiance distribution on the ground resulting from the occultation of the satellite passing in front of a star. The representative size of a GEO satellite combined with the orbital distance results in the ground shadow being consistent with a Fresnel diffraction pattern when observed at visible wavelengths. A measurement of the ground shadow irradiance is used as an amplitude constraint in a Gerchberg-Saxton phase retrieval algorithm that produces a reconstruction of the satellite's 2D transmission function which is analogous to a reverse contrast image of the satellite. The advantage of shadow imaging is that a terrestrial based redundant set of linearly distributed inexpensive small telescopes, each coupled to high speed detectors, is a more effective resolved imaging system for GEO satellites than a very large telescope under ideal conditions. Modeling and simulation efforts indicate sub-meter spatial resolution can be readily achieved using collection apertures of less than 1 meter in diameter. A mathematical basis is established for the treatment of the physical phenomena involved in the shadow imaging process. This includes the source star brightness and angular extent, and the diffraction of starlight from the satellite

  12. Impact of shadow banks on financial contagion

    OpenAIRE

    Yoshiharu Maeno; Kenji Nishiguchi; Satoshi Morinaga; Hirokazu Matsushima

    2014-01-01

    An asset network systemic risk (ANWSER) model is presented to investigate the impact of how shadow banks are intermingled in a financial system on the severity of financial contagion. Particularly, the focus of this study is the impact of the following three representative topologies of an interbank loan network between shadow banks and regulated banks. (1) Random mixing network: shadow banks and regulated banks are intermingled randomly. (2) Asset-correlated mixing network: banks having bigg...

  13. Shadow Banking – International and Domestic Developments

    OpenAIRE

    Josef Manalo; Kate McLoughlin; Carl Schwartz

    2015-01-01

    One of the lessons from the global financial crisis is that systemic risk to the financial system can arise from outside the regular banking system, in so-called ‘shadow banking’. This article reviews post-crisis international and domestic trends in shadow banking, and regulatory efforts to better understand and address potential risks that may arise. In Australia, systemic risks arising from shadow banking appear limited given its relatively small size and minimal links to the banking system...

  14. Moving Shadow Detection in Video Using Cepstrum

    Directory of Open Access Journals (Sweden)

    Fuat Cogun

    2013-01-01

    Full Text Available Moving shadows constitute problems in various applications such as image segmentation and object tracking. The main cause of these problems is the misclassification of the shadow pixels as target pixels. Therefore, the use of an accurate and reliable shadow detection method is essential to realize intelligent video processing applications. In this paper, a cepstrum-based method for moving shadow detection is presented. The proposed method is tested on outdoor and indoor video sequences using well-known benchmark test sets. To show the improvements over previous approaches, quantitative metrics are introduced and comparisons based on these metrics are made.

  15. Are shadows transparent? An investigation on white, shadows and transparency in pictures

    OpenAIRE

    2009-01-01

    Shadow perception and transparency perception appear to use very similar rules, to the point that from the perceptual point of view shadows have been considered an instance of transparent objects. We claim that in spite of the similarities, shadows ought not to be considered transparent entities. The discussion has consequences both for the issue of the location of shadows, and for the conceptualization of transparency, and it provides insight into the inner complexities of the conceptual str...

  16. A Conceptual Framework for SAHRA Integrated Multi-resolution Modeling in the Rio Grande Basin

    Science.gov (United States)

    Liu, Y.; Gupta, H.; Springer, E.; Wagener, T.; Brookshire, D.; Duffy, C.

    2004-12-01

    The sustainable management of water resources in a river basin requires an integrated analysis of the social, economic, environmental and institutional dimensions of the problem. Numerical models are commonly used for integration of these dimensions and for communication of the analysis results to stakeholders and policy makers. The National Science Foundation Science and Technology Center for Sustainability of semi-Arid Hydrology and Riparian Areas (SAHRA) has been developing integrated multi-resolution models to assess impacts of climate variability and land use change on water resources in the Rio Grande Basin. These models not only couple natural systems such as surface and ground waters, but will also include engineering, economic and social components that may be involved in water resources decision-making processes. This presentation will describe the conceptual framework being developed by SAHRA to guide and focus the multiple modeling efforts and to assist the modeling team in planning, data collection and interpretation, communication, evaluation, etc. One of the major components of this conceptual framework is a Conceptual Site Model (CSM), which describes the basin and its environment based on existing knowledge and identifies what additional information must be collected to develop technically sound models at various resolutions. The initial CSM is based on analyses of basin profile information that has been collected, including a physical profile (e.g., topographic and vegetative features), a man-made facility profile (e.g., dams, diversions, and pumping stations), and a land use and ecological profile (e.g., demographics, natural habitats, and endangered species). Based on the initial CSM, a Conceptual Physical Model (CPM) is developed to guide and evaluate the selection of a model code (or numerical model) for each resolution to conduct simulations and predictions. A CPM identifies, conceptually, all the physical processes and engineering and socio

  17. Embedded Object Detection with Radar Echo Data by Means of Wavelet Analysis of MRA: Multi-Resolution Analysis

    Directory of Open Access Journals (Sweden)

    Kohei Arai

    2011-09-01

    Full Text Available A method for embedded object detection with radar echo data by means of wavelet analysis of MRA: Multi-Resolution Analysis, in particular, three dimensional wavelet transformations is proposed. In order to improve embedded object detecting capability, not only one dimensional radar echo data but also three dimensional data are used. Through a comparison between one dimensional edge detection with Sobel operator and three dimensional wavelet transformation based edge detection, it is found that the proposed method is superior to the Sobel operator based method.

  18. Fixing the Shadows While Moving the Gnomon

    Science.gov (United States)

    Gangui, Alejandro

    2015-01-01

    It is a common practice to fix a vertical gnomon and study the moving shadow cast by it. This shows our local solar time and gives us a hint regarding the season in which we perform the observation. The moving shadow can also tell us our latitude with high precision. In this paper we propose to exchange the roles and while keeping the shadows…

  19. Diffeomorphisms with Lp-Shadowing Property

    Institute of Scientific and Technical Information of China (English)

    Abbas FAKHARI; Keonhee LEE; Khosro TAJBAKHSH

    2011-01-01

    We give a characterization of structurally stable diffeomorphisms by making use of the notion of Lp-shadowing property. More precisely, we prove that the set of structurally stable diffeo morphisms coincides with the C1-interior of the set of diffeomorphisms having Lp-shadowing property.

  20. Shadow Attenuation With High Dynamic Range Images

    Science.gov (United States)

    Shadow often interferes with accurate image analysis. To mitigate shadow effects in near-earth imagery (2 m above ground level), we created high dynamic range (HDR) nadir images and used them to measure grassland ground cover. HDR composites were created by merging three differentially-exposed image...

  1. Detection of Cast Shadows in Surveillance Applications

    DEFF Research Database (Denmark)

    Erbou, Søren G.; Sørensen, Helge Bjarne Dissing; Stage, Bjarne

    2005-01-01

    Cast shadows from moving objects reduce the general ability of robust classification and tracking of these objects, in outdoor surveillance applications. A method for segmentation of cast shadows is proposed, combining statistical features with a new similarity feature, derived from a physics...

  2. Shadow of rotating regular black holes

    CERN Document Server

    Abdujabbarov, Ahmadjon; Ahmedov, Bobomurat; Ghosh, Sushant G

    2016-01-01

    We study the shadows cast by the different types of rotating regular black holes viz. Ay\\'on-Beato-Garc\\'ia {(ABG)}, Hayward, and Bardeen. These black holes have in addition to the total mass ($M$) and rotation parameter ($a$), different parameters as electric charge ($Q$), deviation parameter ($g$), and magnetic charge ($g_{*}$), respectively. Interestingly, the size of the shadow is affected by these parameters in addition to the rotation parameter. We found that the radius of the shadow in each case decreases monotonically and the distortion parameter increases when the value of these parameters increase. A comparison with the standard Kerr case is also investigated. We have also studied the influence of the plasma environment around regular black holes to discuss its shadow. The presence of the plasma affects the apparent size of the regular black hole's shadow to be increased due to two effects (i) gravitational redshift of the photons and (ii) radial dependence of plasma density.

  3. Multi-resolution Shape Analysis via Non-Euclidean Wavelets: Applications to Mesh Segmentation and Surface Alignment Problems.

    Science.gov (United States)

    Kim, Won Hwa; Chung, Moo K; Singh, Vikas

    2013-01-01

    The analysis of 3-D shape meshes is a fundamental problem in computer vision, graphics, and medical imaging. Frequently, the needs of the application require that our analysis take a multi-resolution view of the shape's local and global topology, and that the solution is consistent across multiple scales. Unfortunately, the preferred mathematical construct which offers this behavior in classical image/signal processing, Wavelets, is no longer applicable in this general setting (data with non-uniform topology). In particular, the traditional definition does not allow writing out an expansion for graphs that do not correspond to the uniformly sampled lattice (e.g., images). In this paper, we adapt recent results in harmonic analysis, to derive Non-Euclidean Wavelets based algorithms for a range of shape analysis problems in vision and medical imaging. We show how descriptors derived from the dual domain representation offer native multi-resolution behavior for characterizing local/global topology around vertices. With only minor modifications, the framework yields a method for extracting interest/key points from shapes, a surprisingly simple algorithm for 3-D shape segmentation (competitive with state of the art), and a method for surface alignment (without landmarks). We give an extensive set of comparison results on a large shape segmentation benchmark and derive a uniqueness theorem for the surface alignment problem.

  4. A multi-resolution, multi-epoch low radio frequency survey of the Kepler K2 mission Campaign 1 field

    CERN Document Server

    Tingay, S J; Wayth, R B; Intema, H; Jagannathan, P; Mooley, K

    2016-01-01

    We present the first dedicated radio continuum survey of a Kepler K2 mission field, Field 1 covering the North Galactic Cap. The survey is wide field, contemporaneous, multi-epoch, and multi-resolution in nature and was conducted at low radio frequencies between 140 and 200 MHz. The multi-epoch and ultra wide field (but relatively low resolution) part of the survey was provided by 15 nights of observation with the Murchison Widefield Array (MWA) over a period of approximately a month, contemporaneous with K2 observations of the field. The multi-resolution aspect of the survey was provided by the low resolution (4') MWA imaging, complemented by non-contemporaneous but much higher resolution (20") observations using the Giant Metrewave Radio Telescope (GMRT). The survey is therefore sensitive to the details of radio structures across a wide range of angular scales. Consistent with other recent low radio frequency surveys, no significant radio transients or variables were detected in the survey. The resulting so...

  5. On the removal of shadows from images.

    Science.gov (United States)

    Finlayson, Graham D; Hordley, Steven D; Lu, Cheng; Drew, Mark S

    2006-01-01

    This paper is concerned with the derivation of a progression of shadow-free image representations. First, we show that adopting certain assumptions about lights and cameras leads to a 1D, gray-scale image representation which is illuminant invariant at each image pixel. We show that as a consequence, images represented in this form are shadow-free. We then extend this 1D representation to an equivalent 2D, chromaticity representation. We show that in this 2D representation, it is possible to relight all the image pixels in the same way, effectively deriving a 2D image representation which is additionally shadow-free. Finally, we show how to recover a 3D, full color shadow-free image representation by first (with the help of the 2D representation) identifying shadow edges. We then remove shadow edges from the edge-map of the original image by edge in-painting and we propose a method to reintegrate this thresholded edge map, thus deriving the sought-after 3D shadow-free image.

  6. Printed shadow masks for organic transistors

    Science.gov (United States)

    Noguchi, Yoshiaki; Sekitani, Tsuyoshi; Someya, Takao

    2007-09-01

    We have manufactured organic field-effect transistors by using shadow masks that are patterned by a screen printing system. The 50-nm-thick pentacene layer is sublimed as a channel in the vacuum system through the shadow mask on the base film with a multilayer patterned by ink-jet. After the deposition of the pentacene layer, the shadow mask is peeled off from the base film without any mechanical damages to the lower structures. The mobility in the saturation regime is 0.4cm2/Vs and the on-off ratio exceeds 105.

  7. Alorithm for Shadow Detection in Real Colour Images

    Directory of Open Access Journals (Sweden)

    Sanjeev Kumar,

    2010-10-01

    Full Text Available Shadow detection in real scene images is always a challenging but yet interesting area. Most shadow detection and segmentation methods are based on image analysis. This paper aimed to give a comprehensive and critical study of current shadow detection methods. Various approaches have been discussed related to shadow detection in images. The principles of these methods rely on intensity difference or texture analysis of the shadow area and the bright area of the same surface. A realtime shadow detection scheme for color images is presented in this paper. The RBG ellipsoidal region technique is used to detect shadow in colour image.

  8. Fixing the shadows while moving the gnomon

    CERN Document Server

    Gangui, Alejandro

    2016-01-01

    It is a common practice to fix a vertical gnomon and study the moving shadow cast by it. This shows our local solar time and gives us a hint regarding the season in which we perform the observation. The moving shadow can also tell us our latitude with high precision. In this paper we propose to exchange the roles and while keeping the shadows fixed on the ground we will move the gnomon. This lets us understand in a simple way the relevance of the tropical lines of latitude and the behavior of shadows in different locations. We then put these ideas into practice using sticks and threads during a solstice on two sites located on opposite sides of the Tropic of Capricorn.

  9. The little book of light and shadow

    CERN Document Server

    Thornton, Linda

    2013-01-01

    Encourage your Early Learners to becom investigators by exploring the concept of light and shadow. These simple and effective activities can be carried out independently with the focus on natural resources.

  10. Fading and shadowing in wireless systems

    CERN Document Server

    Shankar, P Mohana

    2017-01-01

    This book offers a comprehensive overview of fading and shadowing in wireless channels. A number of statistical models including simple, hybrid, compound and cascaded ones are presented along with a detailed discussion of diversity techniques employed to mitigate the effects of fading and shadowing. The effects of co-channel interference before and after the implementation of diversity are also analyzed. To facilitate easy understanding of the models and the analysis, the background on probability and random variables is presented with relevant derivations of densities of the sums, products, ratios as well as order statistics of random variables. The book also provides material on digital modems of interest in wireless systems. The updated edition expands the background materials on probability by offering sections on Laplace and Mellin transforms, parameter estimation, statistical testing and receiver operating characteristics. Newer models for fading, shadowing and shadowed fading are included along with th...

  11. Shadow imaging of geosynchronous satellites: simulation, image reconstruction, and shadow prediction

    Science.gov (United States)

    Douglas, Dennis M.; Hunt, Bobby R.; Sheppard, David G.

    2016-09-01

    Shadow imaging is a technique to obtain highly resolved silhouettes of resident space objects (RSOs) which would otherwise be unattainable using conventional terrestrial based imaging approaches. This is done by post processing the measured irradiance pattern (shadow) cast onto the Earth as the RSO occults a star. The research presented here focuses on shadow imaging of geosynchronous (GEO) satellites with near stationary orbits approximately 36,000 km from the Earth. Shadows pertaining to a set of diverse observing scenarios are simulated and used as inputs to a Fresnel based phase retrieval algorithm. Spatial resolution limits are evaluated and correlated to signal to noise (SNR) metrics. Resolvable feature sizes of less than 1 m are shown to be readily achievable using foreseeable observing scenarios. Initial output from a shadow prediction tool indicates that there are, on average, over 1000 shadows on the Earth on any given time from a single GEO satellite for stars brighter than mv=10. Shadow ground track uncertainties are correlated to stellar astrometric errors. Global and localized shadow track maps are presented demonstrating a high feasibility for future shadow collections.

  12. Investigation of the Stability via Shadowing Property

    Directory of Open Access Journals (Sweden)

    Koh Heejeong

    2009-01-01

    Full Text Available The shadowing property is to find an exact solution to an iterated map that remains close to an approximate solution. In this article, using shadowing property, we show the stability of the following equation in normed group: , where , and is a mapping. And we prove that the even mapping which satisfies the above equation is quadratic and also the Hyers-Ulam stability of the functional equation in Banach spaces.

  13. Boundary Correct Real-Time Soft Shadows

    DEFF Research Database (Denmark)

    Jacobsen, Bjarke; Christensen, Niels Jørgen; Larsen, Bent Dalgaard

    2004-01-01

    This paper describes a method to determine correct shadow boundaries from an area light source using umbra and penumbra volumes. The light source is approximated by a circular disk as this gives a fast way to extrude the volumes. The method also gives a crude estimate of the visibility of the are...... for implementation on most programmable hardware. Though some crude approximations are used in the visibility function, the method can be used to produce soft shadows with correct boundaries in real time....

  14. In the shadow of death.

    Science.gov (United States)

    Meissner, W W

    1995-08-01

    Death dogged Vincent's footsteps throughout his life, and formed a core component of his unconscious fantasy system. It cast a lugubrious shadow over all of his undertakings--he found little joy and less love in life. It found its way onto his canvases, both directly--the grinning death's head--and indirectly. It found expression in his portrayals of sowers and reapers, in his representations of trees--especially the highly symbolic treatments of cypresses--in the menacing crows hovering over storm-darkened fields of wheat, and finally in the images of Christ, suffering and dead, held in the embrace of a loving and grieving mother. If death was a bottomless pit that haunted him with its terrors, it was also a siren song that drew him ever closer to his destiny, ever closer to the edge of the pit. The power of that attraction lies in his identification with the dead Vincent whose place he had taken and whose name he bore. It was through that identification, and through the passageway of suffering and death that he would surcease in the arms of a loving and accepting mother whose warm embrace he had sought throughout his odyssey, but in vain. It was to be gained only in and through death. It was only through death that he would find rest from his pain and would gain the heavenly reward of his suffering in eternal love and bliss.

  15. Multi-resolution anisotropy studies of ultrahigh-energy cosmic rays detected at the Pierre Auger Observatory

    CERN Document Server

    Aab, A; Aglietta, M; Samarai, I Al; Albuquerque, I F M; Allekotte, I; Almela, A; Castillo, J Alvarez; Alvarez-Muñiz, J; Anastasi, G A; Anchordoqui, L; Andrada, B; Andringa, S; Aramo, C; Arqueros, F; Arsene, N; Asorey, H; Assis, P; Aublin, J; Avila, G; Badescu, A M; Balaceanu, A; Luz, R J Barreira; Baus, C; Beatty, J J; Becker, K H; Bellido, J A; Berat, C; Bertaina, M E; Bertou, X; Biermann, P L; Billoir, P; Biteau, J; Blaess, S G; Blanco, A; Blazek, J; Bleve, C; Boháčová, M; Boncioli, D; Bonifazi, C; Borodai, N; Botti, A M; Brack, J; Brancus, I; Bretz, T; Bridgeman, A; Briechle, F L; Buchholz, P; Bueno, A; Buitink, S; Buscemi, M; Caballero-Mora, K S; Caccianiga, L; Cancio, A; Canfora, F; Caramete, L; Caruso, R; Castellina, A; Cataldi, G; Cazon, L; Chavez, A G; Chinellato, J A; Chudoba, J; Clay, R W; Colalillo, R; Coleman, A; Collica, L; Coluccia, M R; Conceição, R; Contreras, F; Cooper, M J; Coutu, S; Covault, C E; Cronin, J; D'Amico, S; Daniel, B; Dasso, S; Daumiller, K; Dawson, B R; de Almeida, R M; de Jong, S J; De Mauro, G; Neto, J R T de Mello; De Mitri, I; de Oliveira, J; de Souza, V; Debatin, J; Deligny, O; Di Giulio, C; Di Matteo, A; Castro, M L Díaz; Diogo, F; Dobrigkeit, C; D'Olivo, J C; Anjos, R C dos; Dova, M T; Dundovic, A; Ebr, J; Engel, R; Erdmann, M; Erfani, M; Escobar, C O; Espadanal, J; Etchegoyen, A; Falcke, H; Farrar, G; Fauth, A C; Fazzini, N; Fick, B; Figueira, J M; Filipčič, A; Fratu, O; Freire, M M; Fujii, T; Fuster, A; Gaior, R; García, B; Garcia-Pinto, D; Gaté, F; Gemmeke, H; Gherghel-Lascu, A; Ghia, P L; Giaccari, U; Giammarchi, M; Giller, M; Głas, D; Glaser, C; Golup, G; Berisso, M Gómez; Vitale, P F Gómez; González, N; Gorgi, A; Gorham, P; Gouffon, P; Grillo, A F; Grubb, T D; Guarino, F; Guedes, G P; Hampel, M R; Hansen, P; Harari, D; Harrison, T A; Harton, J L; Hasankiadeh, Q; Haungs, A; Hebbeker, T; Heck, D; Heimann, P; Herve, A E; Hill, G C; Hojvat, C; Holt, E; Homola, P; Hörandel, J R; Horvath, P; Hrabovský, M; Huege, T; Hulsman, J; Insolia, A; Isar, P G; Jandt, I; Jansen, S; Johnsen, J A; Josebachuili, M; Kääpä, A; Kambeitz, O; Kampert, K H; Katkov, I; Keilhauer, B; Kemp, E; Kemp, J; Kieckhafer, R M; Klages, H O; Kleifges, M; Kleinfeller, J; Krause, R; Krohm, N; Kuempel, D; Mezek, G Kukec; Kunka, N; Awad, A Kuotb; LaHurd, D; Lauscher, M; Legumina, R; de Oliveira, M A Leigui; Letessier-Selvon, A; Lhenry-Yvon, I; Link, K; Lopes, L; López, R; Casado, A López; Luce, Q; Lucero, A; Malacari, M; Mallamaci, M; Mandat, D; Mantsch, P; Mariazzi, A G; Mariş, I C; Marsella, G; Martello, D; Martinez, H; Bravo, O Martínez; Meza, J J Masías; Mathes, H J; Mathys, S; Matthews, J; Matthews, J A J; Matthiae, G; Mayotte, E; Mazur, P O; Medina, C; Medina-Tanco, G; Melo, D; Menshikov, A; Messina, S; Micheletti, M I; Middendorf, L; Minaya, I A; Miramonti, L; Mitrica, B; Mockler, D; Mollerach, S; Montanet, F; Morello, C; Mostafá, M; Müller, A L; Müller, G; Muller, M A; Müller, S; Mussa, R; Naranjo, I; Nellen, L; Nguyen, P H; Niculescu-Oglinzanu, M; Niechciol, M; Niemietz, L; Niggemann, T; Nitz, D; Nosek, D; Novotny, V; Nožka, H; Núñez, L A; Ochilo, L; Oikonomou, F; Olinto, A; Selmi-Dei, D Pakk; Palatka, M; Pallotta, J; Papenbreer, P; Parente, G; Parra, A; Paul, T; Pech, M; Pedreira, F; Pękala, J; Pelayo, R; Peña-Rodriguez, J; Pereira, L A S; Perlín, M; Perrone, L; Peters, C; Petrera, S; Phuntsok, J; Piegaia, R; Pierog, T; Pieroni, P; Pimenta, M; Pirronello, V; Platino, M; Plum, M; Porowski, C; Prado, R R; Privitera, P; Prouza, M; Quel, E J; Querchfeld, S; Quinn, S; Ramos-Pollan, R; Rautenberg, J; Ravignani, D; Revenu, B; Ridky, J; Risse, M; Ristori, P; Rizi, V; de Carvalho, W Rodrigues; Fernandez, G Rodriguez; Rojo, J Rodriguez; Rogozin, D; Roncoroni, M J; Roth, M; Roulet, E; Rovero, A C; Ruehl, P; Saffi, S J; Saftoiu, A; Salazar, H; Saleh, A; Greus, F Salesa; Salina, G; Sánchez, F; Sanchez-Lucas, P; Santos, E M; Santos, E; Sarazin, F; Sarmento, R; Sarmiento, C A; Sato, R; Schauer, M; Scherini, V; Schieler, H; Schimp, M; Schmidt, D; Scholten, O; Schovánek, P; Schröder, F G; Schulz, A; Schulz, J; Schumacher, J; Sciutto, S J; Segreto, A; Settimo, M; Shadkam, A; Shellard, R C; Sigl, G; Silli, G; Sima, O; Śmiałkowski, A; Šmída, R; Snow, G R; Sommers, P; Sonntag, S; Sorokin, J; Squartini, R; Stanca, D; Stanič, S; Stasielak, J; Stassi, P; Strafella, F; Suarez, F; Durán, M Suarez; Sudholz, T; Suomijärvi, T; Supanitsky, A D; Swain, J; Szadkowski, Z; Taboada, A; Taborda, O A; Tapia, A; Theodoro, V M; Timmermans, C; Peixoto, C J Todero; Tomankova, L; Tomé, B; Elipe, G Torralba; Torri, M; Travnicek, P; Trini, M; Ulrich, R; Unger, M; Urban, M; Galicia, J F Valdés; Valiño, I; Valore, L; van Aar, G; van Bodegom, P; Berg, A M van den; van Vliet, A; Varela, E; Cárdenas, B Vargas; Varner, G; Vázquez, J R; Vázquez, R A; Veberič, D; Quispe, I D Vergara; Verzi, V; Vicha, J; Villaseñor, L; Vorobiov, S; Wahlberg, H; Wainberg, O; Walz, D; Watson, A A; Weber, M; Weindl, A; Wiencke, L; Wilczyński, H; Winchen, T; Wittkowski, D; Wundheiler, B; Yang, L; Yelos, D; Yushkov, A; Zas, E; Zavrtanik, D; Zavrtanik, M; Zepeda, A; Zimmermann, B; Ziolkowski, M; Zong, Z; Zuccarello, F

    2016-01-01

    We report a multi-resolution search for anisotropies in the arrival directions of cosmic rays detected at the Pierre Auger Observatory with local zenith angles up to $80^\\circ$ and energies in excess of 4 EeV ($4 \\times 10^{18}$ eV). This search is conducted by measuring the angular power spectrum and performing a needlet wavelet analysis in two independent energy ranges. No deviation from isotropy is observed on any angular scale in the energy range between 4 and 8 EeV. Above 8 EeV, an indication for a dipole moment is captured; while no other deviation from isotropy is observed for moments beyond the dipole one. While these results are consistent with previous reports making use of the same data set, they provide extensions of the previous works through the thorough scans of the angular scales.

  16. MULTI-RESOLUTION MOTION ESTIMATION AND COMPENSATION BASED ON ADJACENT PREDICTION OF FRAME DIFFERENCE IN WAVELET DOMAIN

    Institute of Scientific and Technical Information of China (English)

    Tang Guowei; Gu Guochang

    2009-01-01

    Aiming at the higher bit-rate occupation of motion vector encoding and more time load of full-searching strategies,a multi-resolution motion estimation and compensation algorithm based on adjacent prediction of frame difference was proposed.Differential motion detection was employed to image sequences and proper threshold was adopted to identify the connected region.Then the motion region was extracted to carry out motion estimation and motion compensation on it.The experiment results show that the encoding efficiency of motion vector is promoted,the complexity of motion es timation is reduced and the quality of the reconstruction image at the same bit-rate as Multi-Reso lution Motion Estimation (MRME) is improved.

  17. Quantum Simulations of Nuclei and Nuclear Pasta with the Multi-resolution Adaptive Numerical Environment for Scientific Simulations

    CERN Document Server

    Sagert, I; Fattoyev, F J; Postnikov, S; Horowitz, C J

    2015-01-01

    Neutron star and supernova matter at densities just below the nuclear matter saturation density is expected to form a lattice of exotic shapes. These so-called nuclear pasta phases are caused by Coulomb frustration. Their elastic and transport properties are believed to play an important role for thermal and magnetic field evolution, rotation and oscillation of neutron stars. Furthermore, they can impact neutrino opacities in core-collapse supernovae. In this work, we present proof-of-principle 3D Skyrme Hartree-Fock (SHF) simulations of nuclear pasta with the Multi-resolution ADaptive Numerical Environment for Scientific Simulations (MADNESS). We perform benchmark studies of $^{16} \\mathrm{O}$, $^{208} \\mathrm{Pb}$ and $^{238} \\mathrm{U}$ nuclear ground states and calculate binding energies via 3D SHF simulations. Results are compared with experimentally measured binding energies as well as with theoretically predicted values from an established SHF code. The nuclear pasta simulation is initialized in the so...

  18. Multi-resolution internal template cleaning: An application to the Wilkinson Microwave Anisotropy Probe 7-yr polarization data

    CERN Document Server

    Fernández-Cobos, R; Barreiro, R B; Martínez-González, E

    2012-01-01

    Cosmic microwave background (CMB) radiation data obtained by different experiments contain, besides the desired signal, a superposition of microwave sky contributions. We present a fast and robust method, using a wavelet decomposition on the sphere, to recover the CMB signal from microwave maps. An application to \\textit{WMAP} polarization data is presented, showing its good performance particularly in very polluted regions of the sky. The applied wavelet has the advantages of requiring little computational time in its calculations, being adapted to the \\textit{HEALPix} pixelization scheme, and offering the possibility of multi-resolution analysis. The decomposition is implemented as part of a fully internal template fitting method, minimizing the variance of the resulting map at each scale. In terms of residual levels of foregrounds, we get better results to those obtained by the \\textit{WMAP} team working in real space and with additional external data sets. Regarding the instrumental noise level in the cle...

  19. Hierarchical progressive surveys. Multi-resolution HEALPix data structures for astronomical images, catalogues, and 3-dimensional data cubes

    CERN Document Server

    Fernique, P; Boch, T; Oberto, A; Pineau, F-X; Durand, D; Bot, C; Cambresy, L; Derriere, S; Genova, F; Bonnarel, F

    2015-01-01

    Scientific exploitation of the ever increasing volumes of astronomical data requires efficient and practical methods for data access, visualisation, and analysis. Hierarchical sky tessellation techniques enable a multi-resolution approach to organising data on angular scales from the full sky down to the individual image pixels. Aims. We aim to show that the Hierarchical progressive survey (HiPS) scheme for describing astronomical images, source catalogues, and three-dimensional data cubes is a practical solution to managing large volumes of heterogeneous data and that it enables a new level of scientific interoperability across large collections of data of these different data types. Methods. HiPS uses the HEALPix tessellation of the sphere to define a hierarchical tile and pixel structure to describe and organise astronomical data. HiPS is designed to conserve the scientific properties of the data alongside both visualisation considerations and emphasis on the ease of implementation. We describe the develop...

  20. MRI data driven partial volume effects correction in PET imaging using 3D local multi-resolution analysis

    Energy Technology Data Exchange (ETDEWEB)

    Le Pogam, Adrien, E-mail: adrien.lepogam@univ-brest.fr [INSERM UMR 1101, LaTIM, Brest (France); Lamare, Frederic [Academic Nuclear Medicine Department, CHU Pellegrin, Bordeaux (France); Hatt, Mathieu [INSERM UMR 1101, LaTIM, Brest (France); Fernandez, Philippe [Academic Nuclear Medicine Department, CHU Pellegrin, Bordeaux (France); Le Rest, Catherine Cheze [INSERM UMR 1101, LaTIM, Brest (France); Academic Nuclear Medicine Department, CHU Poitiers, Poitiers (France); Visvikis, Dimitris [INSERM UMR 1101, LaTIM, Brest (France)

    2013-02-21

    PET partial volume effects (PVE) resulting from the limited resolution of PET scanners is still a quantitative issue that PET/MRI scanners do not solve by themselves. A recently proposed voxel-based locally adaptive 3D multi-resolution PVE correction based on the mutual analysis of wavelet decompositions was applied on 12 clinical {sup 18}F-FLT PET/T1 MRI images of glial tumors, and compared to a PET only voxel-wise iterative deconvolution approach. Quantitative and qualitative results demonstrated the interest of exploiting PET/MRI information with higher uptake increases (19±8% vs. 11±7%, p=0.02), as well as more convincing visual restoration of details within tumors with respect to deconvolution of the PET uptake only. Further studies are now required to demonstrate the accuracy of this restoration with histopathological validation of the uptake in tumors.

  1. Identifying Spatial Units of Human Occupation in the Brazilian Amazon Using Landsat and CBERS Multi-Resolution Imagery

    Directory of Open Access Journals (Sweden)

    Maria Isabel Sobral Escada

    2012-01-01

    Full Text Available Every spatial unit of human occupation is part of a network structuring an extensive process of urbanization in the Amazon territory. Multi-resolution remote sensing data were used to identify and map human presence and activities in the Sustainable Forest District of Cuiabá-Santarém highway (BR-163, west of Pará, Brazil. The limits of spatial units of human occupation were mapped based on digital classification of Landsat-TM5 (Thematic Mapper 5 image (30m spatial resolution. High-spatial-resolution CBERS-HRC (China-Brazil Earth Resources Satellite-High-Resolution Camera images (5 m merged with CBERS-CCD (Charge Coupled Device images (20 m were used to map spatial arrangements inside each populated unit, describing intra-urban characteristics. Fieldwork data validated and refined the classification maps that supported the categorization of the units. A total of 133 spatial units were individualized, comprising population centers as municipal seats, villages and communities, and units of human activities, such as sawmills, farmhouses, landing strips, etc. From the high-resolution analysis, 32 population centers were grouped in four categories, described according to their level of urbanization and spatial organization as: structured, recent, established and dependent on connectivity. This multi-resolution approach provided spatial information about the urbanization process and organization of the territory. It may be extended into other areas or be further used to devise a monitoring system, contributing to the discussion of public policy priorities for sustainable development in the Amazon.

  2. IMPROVING STUDENTS’ LISTENING SKILL THROUGH SHADOWING

    Directory of Open Access Journals (Sweden)

    Mukminatus Zuhriyah

    2016-12-01

    Full Text Available Listening is the first part of language skills that everyone gets when learning a language. It comes before speaking, reading, and writing. Meanwhile, most of the students get difficulty to learn listening of a foreign language, especially English. That is why shadowing was applied in the listening class as one of the solutions to make the learners of English listening easy to understand what the speaker says. This collaborative classroom action research was generally to know whether or not shadowing could improve the students listening skill. It was also specifically to know: (1 the lecturer’s activities, (2 the students’ activities, and (3 the students’ responses during the implementation of shadowing in the listening class. The subjects were 18 students of the third semester of English department of education faculty of Hasyim Asy’ari university (UNHASY Tebuireng Jombang in the academic year of 2016/2017. The data were obtained from the observations got from the notes written by the collaborator and the listening test. The students’ listening skill improved after the implementation of shadowing. It could be seen in the improvement of mean score, from 74.2 in cycle one to 75 in cycle two. Then, the precentage of students passing the minimum mastery criteria also improved, from 61% in cycle one to 77.8% in cycle two. Thus, it can be concluded that shadowing could improve students’ listening skill.

  3. Shapes of rotating nonsingular black hole shadows

    CERN Document Server

    Amir, Muhammed

    2016-01-01

    It is a belief that singularities are creation of general relativity and hence in the absence of a quantum gravity, models of nonsingular black hole have received significant attention. We study the shadow (apparent shape), an optical appearance because of its strong gravitational field, cast by a nonsingular black hole which is characterized by three parameters, i.e., mass ($M$), spin ($a$) and a deviation parameter ($k$). The nonsingular black hole, under consideration, is a generalization of the Kerr black hole can be recognized asymptotically ($r>>k, k>0$) explicitly as the Kerr\\(-\\)Newman black hole, and in the limit $k \\rightarrow 0$ as the Kerr black hole. It turns out that the shadow of a nonsingular black hole is a dark zone covered by deformed circle. Interestingly, it is seen that the shadow of a black hole is affected due to the parameter $k$. Indeed, for a given $a$, the size of a shadow reduces as the parameter $k$ increases and the shadow becomes more distorted as we increase the value of the p...

  4. Gluon Shadowing in DIS off Nuclei

    CERN Document Server

    Kopeliovich, B Z; Potashnikova, I K; Schmidt, I

    2008-01-01

    Within a light-cone quantum-chromodynamics dipole formalism based on the Green function technique, we study nuclear shadowing in deep-inelastic scattering at small Bjorken xB 0.0001, when a variation of the transverse size of the \\bar{q}q Fock component must be taken into account. The eikonal approximation, used so far in most other models, can be applied only at high energies, when xB < 0.0001 and the transverse size of the \\bar{q}q Fock component is "frozen" during propagation through the nuclear matter. At xB < 0.01 we find quite a large contribution of gluon suppression to nuclear shadowing, as a shadowing correction for the higher Fock states containing gluons. Numerical results for nuclear shadowing are compared with the available data from the E665 and NMC collaborations. Nuclear shadowing is also predicted at very small xB corresponding to LHC kinematical range. Finally the model predictions are compared and discussed with the results obtained from other models.

  5. Shadows alter facial expressions of Noh masks.

    Science.gov (United States)

    Kawai, Nobuyuki; Miyata, Hiromitsu; Nishimura, Ritsuko; Okanoya, Kazuo

    2013-01-01

    A Noh mask, worn by expert actors during performance on the Japanese traditional Noh drama, conveys various emotional expressions despite its fixed physical properties. How does the mask change its expressions? Shadows change subtly during the actual Noh drama, which plays a key role in creating elusive artistic enchantment. We here describe evidence from two experiments regarding how attached shadows of the Noh masks influence the observers' recognition of the emotional expressions. In Experiment 1, neutral-faced Noh masks having the attached shadows of the happy/sad masks were recognized as bearing happy/sad expressions, respectively. This was true for all four types of masks each of which represented a character differing in sex and age, even though the original characteristics of the masks also greatly influenced the evaluation of emotions. Experiment 2 further revealed that frontal Noh mask images having shadows of upward/downward tilted masks were evaluated as sad/happy, respectively. This was consistent with outcomes from preceding studies using actually tilted Noh mask images. Results from the two experiments concur that purely manipulating attached shadows of the different types of Noh masks significantly alters the emotion recognition. These findings go in line with the mysterious facial expressions observed in Western paintings, such as the elusive qualities of Mona Lisa's smile. They also agree with the aesthetic principle of Japanese traditional art "yugen (profound grace and subtlety)", which highly appreciates subtle emotional expressions in the darkness.

  6. Shadows alter facial expressions of Noh masks.

    Directory of Open Access Journals (Sweden)

    Nobuyuki Kawai

    Full Text Available BACKGROUND: A Noh mask, worn by expert actors during performance on the Japanese traditional Noh drama, conveys various emotional expressions despite its fixed physical properties. How does the mask change its expressions? Shadows change subtly during the actual Noh drama, which plays a key role in creating elusive artistic enchantment. We here describe evidence from two experiments regarding how attached shadows of the Noh masks influence the observers' recognition of the emotional expressions. METHODOLOGY/PRINCIPAL FINDINGS: In Experiment 1, neutral-faced Noh masks having the attached shadows of the happy/sad masks were recognized as bearing happy/sad expressions, respectively. This was true for all four types of masks each of which represented a character differing in sex and age, even though the original characteristics of the masks also greatly influenced the evaluation of emotions. Experiment 2 further revealed that frontal Noh mask images having shadows of upward/downward tilted masks were evaluated as sad/happy, respectively. This was consistent with outcomes from preceding studies using actually tilted Noh mask images. CONCLUSIONS/SIGNIFICANCE: Results from the two experiments concur that purely manipulating attached shadows of the different types of Noh masks significantly alters the emotion recognition. These findings go in line with the mysterious facial expressions observed in Western paintings, such as the elusive qualities of Mona Lisa's smile. They also agree with the aesthetic principle of Japanese traditional art "yugen (profound grace and subtlety", which highly appreciates subtle emotional expressions in the darkness.

  7. Shadow Economy in Slovenia: The Labour Approach

    Directory of Open Access Journals (Sweden)

    Bojan Nastav

    2007-06-01

    Full Text Available The all-around notorious shadow economy phenomenon is subject to constant reshaping, regarding both time and place, which results in a somewhat unclear definition. We use the following definition: all productive activities, whose output is legal, but is deliberately concealed from the authorities, usually for gaining financial benefits. Different methods of quantifying the size of the shadow economy have been developed. We focus on the labour approach, with Slovenia as the case study during the last decade. The importance of such an analysis lies in the ambiguous effects of the shadow economy and their policy implications. We found that the shadow economy that relates only to the unemployment discrepancies in Slovenia amounts on average to around 6 percent of the official economy, and tends to slightly decline over the most recent years. On the other hand, employment discrepancy and more detailed activity-level results give much higher values and even an increase in the shadow economy: on average around 20 percent in the studied period.

  8. Interactive removal and ground truth for difficult shadow scenes.

    Science.gov (United States)

    Gong, Han; Cosker, Darren

    2016-09-01

    A user-centric method for fast, interactive, robust, and high-quality shadow removal is presented. Our algorithm can perform detection and removal in a range of difficult cases, such as highly textured and colored shadows. To perform detection, an on-the-fly learning approach is adopted guided by two rough user inputs for the pixels of the shadow and the lit area. After detection, shadow removal is performed by registering the penumbra to a normalized frame, which allows us efficient estimation of nonuniform shadow illumination changes, resulting in accurate and robust removal. Another major contribution of this work is the first validated and multiscene category ground truth for shadow removal algorithms. This data set containing 186 images eliminates inconsistencies between shadow and shadow-free images and provides a range of different shadow types such as soft, textured, colored, and broken shadow. Using this data, the most thorough comparison of state-of-the-art shadow removal methods to date is performed, showing our proposed algorithm to outperform the state of the art across several measures and shadow categories. To complement our data set, an online shadow removal benchmark website is also presented to encourage future open comparisons in this challenging field of research.

  9. Interactive removal and ground truth for difficult shadow scenes

    Science.gov (United States)

    Gong, Han; Cosker, Darren

    2016-09-01

    A user-centric method for fast, interactive, robust and high-quality shadow removal is presented. Our algorithm can perform detection and removal in a range of difficult cases: such as highly textured and colored shadows. To perform detection an on-the-fly learning approach is adopted guided by two rough user inputs for the pixels of the shadow and the lit area. After detection, shadow removal is performed by registering the penumbra to a normalized frame which allows us efficient estimation of non-uniform shadow illumination changes, resulting in accurate and robust removal. Another major contribution of this work is the first validated and multi-scene category ground truth for shadow removal algorithms. This data set containing 186 images eliminates inconsistencies between shadow and shadow-free images and provides a range of different shadow types such as soft, textured, colored and broken shadow. Using this data, the most thorough comparison of state-of-the-art shadow removal methods to date is performed, showing our proposed new algorithm to outperform the state-of-the-art across several measures and shadow category. To complement our dataset, an online shadow removal benchmark website is also presented to encourage future open comparisons in this challenging field of research.

  10. The Hero and His Shadow

    Directory of Open Access Journals (Sweden)

    Simona Micali

    2010-08-01

    Full Text Available

     

    Abstract (E: This essay traces the literary theme of the ‘disobedient shadow’ from the Romantic archetype to its adaptation nineteenth- and twentieth-century fantastic fiction. Focusing on texts in which the shadow takes up its own identity, becoming an uncanny double of its master, it is argued that the development of this theme is closely linked with the evolution of the human subject through the epistemological and cultural revolutions of the last two centuries.

    Abstract (F:

     

    Cet article retrace l’évolution du thème littéraire de l’ « ombre désobéissante », de l’archétype romantique aux mutations ultérieures dans la fiction fantastique des 19e et 20e siècles. Il examine un corpus où l’ombre assume son indépendance, devenant un double de son maître dans un esprit que l’on sait être maintenant celui de l

  11. Power Quality Disturbances Feature Selection and Recognition Using Optimal Multi-Resolution Fast S-Transform and CART Algorithm

    Directory of Open Access Journals (Sweden)

    Nantian Huang

    2016-11-01

    Full Text Available In order to improve the recognition accuracy and efficiency of power quality disturbances (PQD in microgrids, a novel PQD feature selection and recognition method based on optimal multi-resolution fast S-transform (OMFST and classification and regression tree (CART algorithm is proposed. Firstly, OMFST is carried out according to the frequency domain characteristic of disturbance signal, and 67 features are extracted by time-frequency analysis to construct the original feature set. Subsequently, the optimal feature subset is determined by Gini importance and sorted according to an embedded feature selection method based on the Gini index. Finally, one standard error rule subtree evaluation methods were applied for cost complexity pruning. After pruning, the optimal decision tree (ODT is obtained for PQD classification. The experiments show that the new method can effectively improve the classification efficiency and accuracy with feature selection step. Simultaneously, the ODT can be constructed automatically according to the ability of feature classification. In different noise environments, the classification accuracy of the new method is higher than the method based on probabilistic neural network, extreme learning machine, and support vector machine.

  12. The Multi-Resolution Land Characteristics (MRLC) Consortium: 20 years of development and integration of USA national land cover data

    Science.gov (United States)

    Wickham, James D.; Homer, Collin G.; Vogelmann, James E.; McKerrow, Alexa; Mueller, Rick; Herold, Nate; Coluston, John

    2014-01-01

    The Multi-Resolution Land Characteristics (MRLC) Consortium demonstrates the national benefits of USA Federal collaboration. Starting in the mid-1990s as a small group with the straightforward goal of compiling a comprehensive national Landsat dataset that could be used to meet agencies’ needs, MRLC has grown into a group of 10 USA Federal Agencies that coordinate the production of five different products, including the National Land Cover Database (NLCD), the Coastal Change Analysis Program (C-CAP), the Cropland Data Layer (CDL), the Gap Analysis Program (GAP), and the Landscape Fire and Resource Management Planning Tools (LANDFIRE). As a set, the products include almost every aspect of land cover from impervious surface to detailed crop and vegetation types to fire fuel classes. Some products can be used for land cover change assessments because they cover multiple time periods. The MRLC Consortium has become a collaborative forum, where members share research, methodological approaches, and data to produce products using established protocols, and we believe it is a model for the production of integrated land cover products at national to continental scales. We provide a brief overview of each of the main products produced by MRLC and examples of how each product has been used. We follow that with a discussion of the impact of the MRLC program and a brief overview of future plans.

  13. A Multi-Resolution Approach for an Automated Fusion of Different Low-Cost 3D Sensors

    Directory of Open Access Journals (Sweden)

    Jan Dupuis

    2014-04-01

    Full Text Available The 3D acquisition of object structures has become a common technique in many fields of work, e.g., industrial quality management, cultural heritage or crime scene documentation. The requirements on the measuring devices are versatile, because spacious scenes have to be imaged with a high level of detail for selected objects. Thus, the used measuring systems are expensive and require an experienced operator. With the rise of low-cost 3D imaging systems, their integration into the digital documentation process is possible. However, common low-cost sensors have the limitation of a trade-off between range and accuracy, providing either a low resolution of single objects or a limited imaging field. Therefore, the use of multiple sensors is desirable. We show the combined use of two low-cost sensors, the Microsoft Kinect and the David laserscanning system, to achieve low-resolved scans of the whole scene and a high level of detail for selected objects, respectively. Afterwards, the high-resolved David objects are automatically assigned to their corresponding Kinect object by the use of surface feature histograms and SVM-classification. The corresponding objects are fitted using an ICP-implementation to produce a multi-resolution map. The applicability is shown for a fictional crime scene and the reconstruction of a ballistic trajectory.

  14. A multi-resolution approach for an automated fusion of different low-cost 3D sensors.

    Science.gov (United States)

    Dupuis, Jan; Paulus, Stefan; Behmann, Jan; Plümer, Lutz; Kuhlmann, Heiner

    2014-04-24

    The 3D acquisition of object structures has become a common technique in many fields of work, e.g., industrial quality management, cultural heritage or crime scene documentation. The requirements on the measuring devices are versatile, because spacious scenes have to be imaged with a high level of detail for selected objects. Thus, the used measuring systems are expensive and require an experienced operator. With the rise of low-cost 3D imaging systems, their integration into the digital documentation process is possible. However, common low-cost sensors have the limitation of a trade-off between range and accuracy, providing either a low resolution of single objects or a limited imaging field. Therefore, the use of multiple sensors is desirable. We show the combined use of two low-cost sensors, the Microsoft Kinect and the David laserscanning system, to achieve low-resolved scans of the whole scene and a high level of detail for selected objects, respectively. Afterwards, the high-resolved David objects are automatically assigned to their corresponding Kinect object by the use of surface feature histograms and SVM-classification. The corresponding objects are fitted using an ICP-implementation to produce a multi-resolution map. The applicability is shown for a fictional crime scene and the reconstruction of a ballistic trajectory.

  15. Multi-resolution anisotropy studies of ultrahigh-energy cosmic rays detected at the Pierre Auger Observatory

    Science.gov (United States)

    Aab, A.; Abreu, P.; Aglietta, M.; Samarai, I. Al; Albuquerque, I. F. M.; Allekotte, I.; Almela, A.; Alvarez Castillo, J.; Alvarez-Muñiz, J.; Anastasi, G. A.; Anchordoqui, L.; Andrada, B.; Andringa, S.; Aramo, C.; Arqueros, F.; Arsene, N.; Asorey, H.; Assis, P.; Aublin, J.; Avila, G.; Badescu, A. M.; Balaceanu, A.; Barreira Luz, R. J.; Baus, C.; Beatty, J. J.; Becker, K. H.; Bellido, J. A.; Berat, C.; Bertaina, M. E.; Bertou, X.; Biermann, P. L.; Billoir, P.; Biteau, J.; Blaess, S. G.; Blanco, A.; Blazek, J.; Bleve, C.; Boháčová, M.; Boncioli, D.; Bonifazi, C.; Borodai, N.; Botti, A. M.; Brack, J.; Brancus, I.; Bretz, T.; Bridgeman, A.; Briechle, F. L.; Buchholz, P.; Bueno, A.; Buitink, S.; Buscemi, M.; Caballero-Mora, K. S.; Caccianiga, L.; Cancio, A.; Canfora, F.; Caramete, L.; Caruso, R.; Castellina, A.; Cataldi, G.; Cazon, L.; Chavez, A. G.; Chinellato, J. A.; Chudoba, J.; Clay, R. W.; Colalillo, R.; Coleman, A.; Collica, L.; Coluccia, M. R.; Conceição, R.; Contreras, F.; Cooper, M. J.; Coutu, S.; Covault, C. E.; Cronin, J.; D'Amico, S.; Daniel, B.; Dasso, S.; Daumiller, K.; Dawson, B. R.; de Almeida, R. M.; de Jong, S. J.; De Mauro, G.; de Mello Neto, J. R. T.; De Mitri, I.; de Oliveira, J.; de Souza, V.; Debatin, J.; Deligny, O.; Di Giulio, C.; Di Matteo, A.; Díaz Castro, M. L.; Diogo, F.; Dobrigkeit, C.; D'Olivo, J. C.; dos Anjos, R. C.; Dova, M. T.; Dundovic, A.; Ebr, J.; Engel, R.; Erdmann, M.; Erfani, M.; Escobar, C. O.; Espadanal, J.; Etchegoyen, A.; Falcke, H.; Farrar, G.; Fauth, A. C.; Fazzini, N.; Fick, B.; Figueira, J. M.; Filipčič, A.; Fratu, O.; Freire, M. M.; Fujii, T.; Fuster, A.; Gaior, R.; García, B.; Garcia-Pinto, D.; Gaté, F.; Gemmeke, H.; Gherghel-Lascu, A.; Ghia, P. L.; Giaccari, U.; Giammarchi, M.; Giller, M.; Głas, D.; Glaser, C.; Golup, G.; Gómez Berisso, M.; Gómez Vitale, P. F.; González, N.; Gorgi, A.; Gorham, P.; Gouffon, P.; Grillo, A. F.; Grubb, T. D.; Guarino, F.; Guedes, G. P.; Hampel, M. R.; Hansen, P.; Harari, D.; Harrison, T. A.; Harton, J. L.; Hasankiadeh, Q.; Haungs, A.; Hebbeker, T.; Heck, D.; Heimann, P.; Herve, A. E.; Hill, G. C.; Hojvat, C.; Holt, E.; Homola, P.; Hörandel, J. R.; Horvath, P.; Hrabovský, M.; Huege, T.; Hulsman, J.; Insolia, A.; Isar, P. G.; Jandt, I.; Jansen, S.; Johnsen, J. A.; Josebachuili, M.; Kääpä, A.; Kambeitz, O.; Kampert, K. H.; Katkov, I.; Keilhauer, B.; Kemp, E.; Kemp, J.; Kieckhafer, R. M.; Klages, H. O.; Kleifges, M.; Kleinfeller, J.; Krause, R.; Krohm, N.; Kuempel, D.; Kukec Mezek, G.; Kunka, N.; Kuotb Awad, A.; LaHurd, D.; Lauscher, M.; Legumina, R.; Leigui de Oliveira, M. A.; Letessier-Selvon, A.; Lhenry-Yvon, I.; Link, K.; Lopes, L.; López, R.; López Casado, A.; Luce, Q.; Lucero, A.; Malacari, M.; Mallamaci, M.; Mandat, D.; Mantsch, P.; Mariazzi, A. G.; Mariş, I. C.; Marsella, G.; Martello, D.; Martinez, H.; Martínez Bravo, O.; Masías Meza, J. J.; Mathes, H. J.; Mathys, S.; Matthews, J.; Matthews, J. A. J.; Matthiae, G.; Mayotte, E.; Mazur, P. O.; Medina, C.; Medina-Tanco, G.; Melo, D.; Menshikov, A.; Messina, S.; Micheletti, M. I.; Middendorf, L.; Minaya, I. A.; Miramonti, L.; Mitrica, B.; Mockler, D.; Mollerach, S.; Montanet, F.; Morello, C.; Mostafá, M.; Müller, A. L.; Müller, G.; Muller, M. A.; Müller, S.; Mussa, R.; Naranjo, I.; Nellen, L.; Nguyen, P. H.; Niculescu-Oglinzanu, M.; Niechciol, M.; Niemietz, L.; Niggemann, T.; Nitz, D.; Nosek, D.; Novotny, V.; Nožka, H.; Núñez, L. A.; Ochilo, L.; Oikonomou, F.; Olinto, A.; Pakk Selmi-Dei, D.; Palatka, M.; Pallotta, J.; Papenbreer, P.; Parente, G.; Parra, A.; Paul, T.; Pech, M.; Pedreira, F.; Pȩkala, J.; Pelayo, R.; Peña-Rodriguez, J.; Pereira, L. A. S.; Perlín, M.; Perrone, L.; Peters, C.; Petrera, S.; Phuntsok, J.; Piegaia, R.; Pierog, T.; Pieroni, P.; Pimenta, M.; Pirronello, V.; Platino, M.; Plum, M.; Porowski, C.; Prado, R. R.; Privitera, P.; Prouza, M.; Quel, E. J.; Querchfeld, S.; Quinn, S.; Ramos-Pollan, R.; Rautenberg, J.; Ravignani, D.; Revenu, B.; Ridky, J.; Risse, M.; Ristori, P.; Rizi, V.; Rodrigues de Carvalho, W.; Rodriguez Fernandez, G.; Rodriguez Rojo, J.; Rogozin, D.; Roncoroni, M. J.; Roth, M.; Roulet, E.; Rovero, A. C.; Ruehl, P.; Saffi, S. J.; Saftoiu, A.; Salazar, H.; Saleh, A.; Salesa Greus, F.; Salina, G.; Sánchez, F.; Sanchez-Lucas, P.; Santos, E. M.; Santos, E.; Sarazin, F.; Sarmento, R.; Sarmiento, C. A.; Sato, R.; Schauer, M.; Scherini, V.; Schieler, H.; Schimp, M.; Schmidt, D.; Scholten, O.; Schovánek, P.; Schröder, F. G.; Schulz, A.; Schulz, J.; Schumacher, J.; Sciutto, S. J.; Segreto, A.; Settimo, M.; Shadkam, A.; Shellard, R. C.; Sigl, G.; Silli, G.; Sima, O.; Śmiałkowski, A.; Šmída, R.; Snow, G. R.; Sommers, P.; Sonntag, S.; Sorokin, J.; Squartini, R.; Stanca, D.; Stanič, S.; Stasielak, J.; Stassi, P.; Strafella, F.; Suarez, F.; Suarez Durán, M.; Sudholz, T.; Suomijärvi, T.; Supanitsky, A. D.; Swain, J.; Szadkowski, Z.; Taboada, A.; Taborda, O. A.; Tapia, A.; Theodoro, V. M.; Timmermans, C.; Todero Peixoto, C. J.; Tomankova, L.; Tomé, B.; Torralba Elipe, G.; Torri, M.; Travnicek, P.; Trini, M.; Ulrich, R.; Unger, M.; Urban, M.; Valdés Galicia, J. F.; Valiño, I.; Valore, L.; van Aar, G.; van Bodegom, P.; van den Berg, A. M.; van Vliet, A.; Varela, E.; Vargas Cárdenas, B.; Varner, G.; Vázquez, J. R.; Vázquez, R. A.; Veberič, D.; Vergara Quispe, I. D.; Verzi, V.; Vicha, J.; Villaseñor, L.; Vorobiov, S.; Wahlberg, H.; Wainberg, O.; Walz, D.; Watson, A. A.; Weber, M.; Weindl, A.; Wiencke, L.; Wilczyński, H.; Winchen, T.; Wittkowski, D.; Wundheiler, B.; Yang, L.; Yelos, D.; Yushkov, A.; Zas, E.; Zavrtanik, D.; Zavrtanik, M.; Zepeda, A.; Zimmermann, B.; Ziolkowski, M.; Zong, Z.; Zuccarello, F.

    2017-06-01

    We report a multi-resolution search for anisotropies in the arrival directions of cosmic rays detected at the Pierre Auger Observatory with local zenith angles up to 80o and energies in excess of 4 EeV (4 × 1018 eV). This search is conducted by measuring the angular power spectrum and performing a needlet wavelet analysis in two independent energy ranges. Both analyses are complementary since the angular power spectrum achieves a better performance in identifying large-scale patterns while the needlet wavelet analysis, considering the parameters used in this work, presents a higher efficiency in detecting smaller-scale anisotropies, potentially providing directional information on any observed anisotropies. No deviation from isotropy is observed on any angular scale in the energy range between 4 and 8 EeV. Above 8 EeV, an indication for a dipole moment is captured; while no other deviation from isotropy is observed for moments beyond the dipole one. The corresponding p-values obtained after accounting for searches blindly performed at several angular scales, are 1.3 × 10-5 in the case of the angular power spectrum, and 2.5 × 10-3 in the case of the needlet analysis. While these results are consistent with previous reports making use of the same data set, they provide extensions of the previous works through the thorough scans of the angular scales.

  16. Multi-resolutional shape features via non-Euclidean wavelets: Applications to statistical analysis of cortical thickness

    Science.gov (United States)

    Kim, Won Hwa; Singh, Vikas; Chung, Moo K.; Hinrichs, Chris; Pachauri, Deepti; Okonkwo, Ozioma C.; Johnson, Sterling C.

    2014-01-01

    Statistical analysis on arbitrary surface meshes such as the cortical surface is an important approach to understanding brain diseases such as Alzheimer’s disease (AD). Surface analysis may be able to identify specific cortical patterns that relate to certain disease characteristics or exhibit differences between groups. Our goal in this paper is to make group analysis of signals on surfaces more sensitive. To do this, we derive multi-scale shape descriptors that characterize the signal around each mesh vertex, i.e., its local context, at varying levels of resolution. In order to define such a shape descriptor, we make use of recent results from harmonic analysis that extend traditional continuous wavelet theory from the Euclidean to a non-Euclidean setting (i.e., a graph, mesh or network). Using this descriptor, we conduct experiments on two different datasets, the Alzheimer’s Disease NeuroImaging Initiative (ADNI) data and images acquired at the Wisconsin Alzheimer’s Disease Research Center (W-ADRC), focusing on individuals labeled as having Alzheimer’s disease (AD), mild cognitive impairment (MCI) and healthy controls. In particular, we contrast traditional univariate methods with our multi-resolution approach which show increased sensitivity and improved statistical power to detect a group-level effects. We also provide an open source implementation. PMID:24614060

  17. Integration of Field and Laboratory Spectral Data with Multi-Resolution Remote Sensed Imagery for Asphalt Surface Differentiation

    Directory of Open Access Journals (Sweden)

    Alessandro Mei

    2014-03-01

    Full Text Available The ability to classify asphalt surfaces is an important goal for the selection of suitable non-variant targets as pseudo-invariant targets during the calibration/validation of remotely-sensed images. In addition, the possibility to recognize different types of asphalt surfaces on the images can help optimize road network management. This paper presents a multi-resolution study to improve asphalt surface differentiation using field spectroradiometric data, laboratory analysis and remote sensing imagery. Multispectral Infrared and Visible Imaging Spectrometer (MIVIS airborne data and multispectral images, such as Quickbird and Ikonos, were used. From scatter plots obtained by field data using λ = 460 and 740 nm, referring to MIVIS Bands 2 and 16 and Quickbird and Ikonos Bands 1 and 4, pixels corresponding to asphalt covering were identified, and the slope of their interpolation lines, assumed as asphalt lines, was calculated. These slopes, used as threshold values in the Spectral Angle Mapper (SAM classifier, obtained an overall accuracy of 95% for Ikonos, 98% for Quickbird and 93% for MIVIS. Laboratory investigations confirm the existence of the asphalt line also for new asphalts, too.

  18. Classification of glioblastoma and metastasis for neuropathology intraoperative diagnosis: a multi-resolution textural approach to model the background

    Science.gov (United States)

    Ahmad Fauzi, Mohammad Faizal; Gokozan, Hamza Numan; Elder, Brad; Puduvalli, Vinay K.; Otero, Jose J.; Gurcan, Metin N.

    2014-03-01

    Brain cancer surgery requires intraoperative consultation by neuropathology to guide surgical decisions regarding the extent to which the tumor undergoes gross total resection. In this context, the differential diagnosis between glioblastoma and metastatic cancer is challenging as the decision must be made during surgery in a short time-frame (typically 30 minutes). We propose a method to classify glioblastoma versus metastatic cancer based on extracting textural features from the non-nuclei region of cytologic preparations. For glioblastoma, these regions of interest are filled with glial processes between the nuclei, which appear as anisotropic thin linear structures. For metastasis, these regions correspond to a more homogeneous appearance, thus suitable texture features can be extracted from these regions to distinguish between the two tissue types. In our work, we use the Discrete Wavelet Frames to characterize the underlying texture due to its multi-resolution capability in modeling underlying texture. The textural characterization is carried out in primarily the non-nuclei regions after nuclei regions are segmented by adapting our visually meaningful decomposition segmentation algorithm to this problem. k-nearest neighbor method was then used to classify the features into glioblastoma or metastasis cancer class. Experiment on 53 images (29 glioblastomas and 24 metastases) resulted in average accuracy as high as 89.7% for glioblastoma, 87.5% for metastasis and 88.7% overall. Further studies are underway to incorporate nuclei region features into classification on an expanded dataset, as well as expanding the classification to more types of cancers.

  19. A Multi-Resolution Approach for an Automated Fusion of Different Low-Cost 3D Sensors

    Science.gov (United States)

    Dupuis, Jan; Paulus, Stefan; Behmann, Jan; Plümer, Lutz; Kuhlmann, Heiner

    2014-01-01

    The 3D acquisition of object structures has become a common technique in many fields of work, e.g., industrial quality management, cultural heritage or crime scene documentation. The requirements on the measuring devices are versatile, because spacious scenes have to be imaged with a high level of detail for selected objects. Thus, the used measuring systems are expensive and require an experienced operator. With the rise of low-cost 3D imaging systems, their integration into the digital documentation process is possible. However, common low-cost sensors have the limitation of a trade-off between range and accuracy, providing either a low resolution of single objects or a limited imaging field. Therefore, the use of multiple sensors is desirable. We show the combined use of two low-cost sensors, the Microsoft Kinect and the David laserscanning system, to achieve low-resolved scans of the whole scene and a high level of detail for selected objects, respectively. Afterwards, the high-resolved David objects are automatically assigned to their corresponding Kinect object by the use of surface feature histograms and SVM-classification. The corresponding objects are fitted using an ICP-implementation to produce a multi-resolution map. The applicability is shown for a fictional crime scene and the reconstruction of a ballistic trajectory. PMID:24763255

  20. SAPHIR - a multi-scale, multi-resolution modeling environment targeting blood pressure regulation and fluid homeostasis.

    Science.gov (United States)

    Thomas, S; Abdulhay, Enas; Baconnier, Pierre; Fontecave, Julie; Francoise, Jean-Pierre; Guillaud, Francois; Hannaert, Patrick; Hernandez, Alfredo; Le Rolle, Virginie; Maziere, Pierre; Tahi, Fariza; Zehraoui, Farida

    2007-01-01

    We present progress on a comprehensive, modular, interactive modeling environment centered on overall regulation of blood pressure and body fluid homeostasis. We call the project SAPHIR, for "a Systems Approach for PHysiological Integration of Renal, cardiac, and respiratory functions". The project uses state-of-the-art multi-scale simulation methods. The basic core model will give succinct input-output (reduced-dimension) descriptions of all relevant organ systems and regulatory processes, and it will be modular, multi-resolution, and extensible, in the sense that detailed submodules of any process(es) can be "plugged-in" to the basic model in order to explore, eg. system-level implications of local perturbations. The goal is to keep the basic core model compact enough to insure fast execution time (in view of eventual use in the clinic) and yet to allow elaborate detailed modules of target tissues or organs in order to focus on the problem area while maintaining the system-level regulatory compensations.

  1. Shadow detection and removal based on the saliency map

    Science.gov (United States)

    Fang, Zhiwen; Cao, Zhiguo; Deng, Chunhua; Yan, Ruicheng; Qin, Yueming

    2013-10-01

    The detection of shadow is the first step to reduce the imaging effect that is caused by the interactions of the light source with surfaces, and then shadow removal can recover the vein information from the dark region. In this paper, we have presented a new method to detect the shadow in a single nature image with the saliency map and to remove the shadow. Firstly, RGB image is transferred to 2D module in order to improve the blue component. Secondly, saliency map of blue component is extracted via graph-based manifold ranking. Then the edge of the shadow can be detected in order to recover the transitional region between the shadow and non-shadow region. Finally, shadow is compensated by enhancing the image in RGB space. Experimental results show the effectiveness of the proposed method.

  2. Chromatic Shadow Detection and Tracking for Moving Foreground Segmentation

    DEFF Research Database (Denmark)

    Huerta, Ivan; Holte, Michael Boelstoft; Moeslund, Thomas B.

    2015-01-01

    Advanced segmentation techniques in the surveillance domain deal with shadows to avoid distortions when detecting moving objects. Most approaches for shadow detection are still typically restricted to penumbra shadows and cannot cope well with umbra shadows. Consequently, umbra shadow regions...... are usually detected as part of moving objects, thus affecting the performance of the final detection. In this paper we address the detection of both penumbra and umbra shadow regions. First, a novel bottom-up approach is presented based on gradient and colour models, which successfully discriminates between...... chromatic moving cast shadow regions and those regions detected as moving objects. In essence, those regions corresponding to potential shadows are detected based on edge partitioning and colour statistics. Subsequently (i) temporal similarities between textures and (ii) spatial similarities between...

  3. Detection and Removal of Chromatic Moving Shadows in Surveillance Scenarios

    DEFF Research Database (Denmark)

    Casado, Ivan Huerta; Holte, Michael Boelstoft; Moeslund, Thomas B.

    2009-01-01

      Segmentation in the surveillance domain has to deal with shadows to avoid distortions when detecting moving objects. Most segmentation approaches dealing with shadow detection are typically restricted to penumbra shadows. Therefore, such techniques cannot cope well with umbra shadows....... Consequently, umbra shadows are usually detected as part of moving objects. In this paper we present a novel technique based on gradient and colour models for separating chromatic moving cast shadows from detected moving objects. Firstly, both a chromatic invariant colour cone model and an invariant gradient...... model are built to perform automatic segmentation while detecting potential shadows. In a second step, regions corresponding to potential shadows are grouped by considering "a bluish effect" and an edge partitioning. Lastly, (i) temporal similarities between textures and (ii) spatial similarities...

  4. Infants' perception of lightness changes related to cast shadows

    Science.gov (United States)

    2017-01-01

    When humans perceive the lightness of an object’s surface in shadows there is an implicit assumption that cast shadows dim the surface. In two experiments, we investigated whether 5- to 8-month-old infants make this assumption about shadows. According to this shadow assumption, the apparent change in lightness produced by shadows on an object’s surface are attributed to blocked light sources. If infants can use the shadow assumption to perceive the object’s lightness in shadows, they will also be able to detect unnatural lightness changes in shadows. We compared the infants’ looking times to the unnatural and the natural lightness changes in the shadow when an object (duck) goes through the cast shadow. In Experiment 1, we examined whether infants could detect the unnatural lightness changes of the object’s surface in shadows. We created computer-graphic movies of unnatural and natural lightness changes to the duck’s surface. Our results showed that 7- to 8-month-olds but not 5- to 6-month-olds significantly preferred the movie with the unnatural changes in lightness, indicating that only the older infants could detect these changes. In Experiment 2, we confirmed that the infants’ preference was based on the detection of unnatural lightness changes according to the shadow assumption. The natural and the unnatural lightness changes of Experiment 1 were presented without cast shadows. Under these conditions, neither younger nor older infants showed a significant preference. Taken together, the experiments showed that 7- to 8-month-old infants could detect the unnaturalness of a surface’s lightness changes produced by shadows. In conclusion, our findings suggest that 7- to 8-month-old infants can perceive an object’s lightness in shadows by using an assumption that cast shadows dim the surface of an object. PMID:28296912

  5. Job Shadowing Introduces the Realities of Manufacturing

    Science.gov (United States)

    Frawley, Thomas A.

    2009-01-01

    Engineers and skilled tradesmen stood side by side with executives and politicians as Liverpool High School technology teacher Dan Drogo welcomed parents to a one-of-a-kind graduation ceremony at New Process Gear in Syracuse, New York. The manufacturing shadow program had immersed 25 high school students in an intensive five-week experience inside…

  6. Hunting the Shadow, Catching the Light

    DEFF Research Database (Denmark)

    Toft, Anne Elisabeth; Nielsen, Torben

    2009-01-01

    From 28 October to 6 November 2009 twenty-one 3rd year students in interior design from Central Academy of Fine Arts (CAFA), School of Architecture, Beijing participated in the workshop Hunting the Shadow - Catching the Light. The workshop was conceived and led by the Danish architects Torben Nie...

  7. Multithreshold progressive image sharing with compact shadows

    Science.gov (United States)

    Chen, Lee Shu-Teng; Lin, Ja-Chen

    2010-01-01

    We propose a multithreshold progressive reconstruction method. The image is encoded three times using Joint Photographic Experts Group (JPEG): first with a low-quality factor, then with a medium-quality factor, and last with a high-quality factor. Huffman coding is employed to encode the difference between the important image and the high-quality JPEG decompressed image. The three JPEG codes and the Huffman code are shared, respectively, according to four prespecified thresholds. The n-generated equally important shadows can be stored or transmitted using n channels in parallel. Cooperation among these generated shadows can progressively reconstruct the important image. The reconstructed image is loss-free when the number of collected shadows reaches the largest threshold. Each shadow is very compact and so can be hidden successfully in the JPEG codes of cover images to reduce the probability of being attacked when transmitted in an unfriendly environment. Comparisons with other image sharing methods are made. The contributions, such as easiness to apply to scalable Moving Picture Experts Group (MPEG) video transmission or resistance to differential attack, are also included.

  8. Robust road detection in shadow conditions

    Science.gov (United States)

    Lu, Kaiyue; Xia, Siyu; Zhang, Junkang; Qin, A. Kai

    2016-07-01

    Image-based road detection is a vital task for many real-world applications, such as autonomous driving and obstacle detection. We propose a method for segmenting road regions from a single image based on horizon line estimation and clustering technology. The key idea is to leverage normalized cross correlation to search for the line separating the road image. Additionally, we divide the lower part of the road image into several identical parts horizontally and utilize a density-peak clustering algorithm in terms of gray and HSV value of each pixel. Clustering results are further labeled as road and nonroad based on the assumption that two adjacent horizontal parts share similar clustering size and average gray value. For road images with shadows, we also propose a new shadow-free space derived from HSV space. By calculating maximum entropy and reconstructing images, we show that shadows are eliminated to achieve better road detection. Experimental results on four datasets and shadow images demonstrate the effectiveness and robustness of our method.

  9. SHADOW PROCESSES INSTATE BUDGET: CURRENT CONDITION AND DETERMINING FACTORS

    Directory of Open Access Journals (Sweden)

    Z. Varnalii

    2014-12-01

    Full Text Available The most significant factors that move state budget into the shadow are determined. Current condition of shadow processes in state budget is highlighted. The paper also provides an analysis of relationship between political processes and shadow economy in public sector of Ukraine.

  10. THE SHADOW ECONOMY AS AN ECONOMIC CATEGORY AND OBJECT EVALUATION

    Directory of Open Access Journals (Sweden)

    А. Khodzhaian

    2014-12-01

    Full Text Available The article considers the existing scientific approaches to the formulation of the concept of nature and the structural elements of the shadow economy. Contains definitions of the shadow economy as an object of evaluation. Disclosed manifestations shadow relations in the context of the institutional sectors. Characterized by methods of assessment of the informal sector in terms of their object of study.

  11. Shadows Alter Facial Expressions of Noh Masks

    Science.gov (United States)

    Kawai, Nobuyuki; Miyata, Hiromitsu; Nishimura, Ritsuko; Okanoya, Kazuo

    2013-01-01

    Background A Noh mask, worn by expert actors during performance on the Japanese traditional Noh drama, conveys various emotional expressions despite its fixed physical properties. How does the mask change its expressions? Shadows change subtly during the actual Noh drama, which plays a key role in creating elusive artistic enchantment. We here describe evidence from two experiments regarding how attached shadows of the Noh masks influence the observers’ recognition of the emotional expressions. Methodology/Principal Findings In Experiment 1, neutral-faced Noh masks having the attached shadows of the happy/sad masks were recognized as bearing happy/sad expressions, respectively. This was true for all four types of masks each of which represented a character differing in sex and age, even though the original characteristics of the masks also greatly influenced the evaluation of emotions. Experiment 2 further revealed that frontal Noh mask images having shadows of upward/downward tilted masks were evaluated as sad/happy, respectively. This was consistent with outcomes from preceding studies using actually tilted Noh mask images. Conclusions/Significance Results from the two experiments concur that purely manipulating attached shadows of the different types of Noh masks significantly alters the emotion recognition. These findings go in line with the mysterious facial expressions observed in Western paintings, such as the elusive qualities of Mona Lisa’s smile. They also agree with the aesthetic principle of Japanese traditional art “yugen (profound grace and subtlety)”, which highly appreciates subtle emotional expressions in the darkness. PMID:23940748

  12. Dense surface reconstruction with shadows in MIS.

    Science.gov (United States)

    Lin, Bingxiong; Sun, Yu; Qian, Xiaoning

    2013-09-01

    Three-dimensional reconstruction of internal organ surfaces provides useful information for better control and guidance of the operations of surgical tools for minimally invasive surgery (MIS). The current reconstruction techniques using stereo cameras are still challenging due to the difficulties in correspondence matching in MIS, since there is very limited texture but significant specular reflection on organ surfaces. This paper proposes a new approach to overcome the problem by introducing weakly structured light actively casting surgical tool shadows on organ surfaces. The contribution of this paper is twofold: first, we propose a robust approach to extract shadow edges from a sequence of shadowed images; second, we develop a novel field surface interpolation (FSI) approach to obtain an accurate and dense disparity map. Our approach does not rely on texture information and is able to reconstruct accurate 3-D information by exploiting shadows from surgical tools. One advantage is that the point correspondences are directly calculated and no explicit stereo matching is required, which ensures the efficiency of the method. Another advantage is the minimum hardware requirement because only stereo cameras and a separated single-point light source are required. We evaluated the proposed approach using both phantom models and ex vivo images. Based on the experimental results, we achieved the precision of the recovered 3-D surfaces within 0.7 mm for phantom models and 1.2 mm for ex vivo images. The comparison of disparity maps indicates that with the addition of shadows, the proposed method significantly outperforms the state-of-the-art stereo algorithms for MIS.

  13. Connecting the shadows: probing inner disk geometries using shadows in transitional disks

    Science.gov (United States)

    Min, M.; Stolker, T.; Dominik, C.; Benisty, M.

    2017-08-01

    Aims: Shadows in transitional disks are generally interpreted as signs of a misaligned inner disk. This disk is usually beyond the reach of current day high contrast imaging facilities. However, the location and morphology of the shadow features allow us to reconstruct the inner disk geometry. Methods: We derive analytic equations of the locations of the shadow features as a function of the orientation of the inner and outer disk and the height of the outer disk wall. In contrast to previous claims in the literature, we show that the position angle of the line connecting the shadows cannot be directly related to the position angle of the inner disk. Results: We show how the analytic framework derived here can be applied to transitional disks with shadow features. We use estimates of the outer disk height to put constraints on the inner disk orientation. In contrast with the results from Long et al. (2017, ApJ, 838, 62), we derive that for the disk surrounding HD 100453 the analytic estimates and interferometric observations result in a consistent picture of the orientation of the inner disk. Conclusions: The elegant consistency in our analytic framework between observation and theory strongly support both the interpretation of the shadow features as coming from a misaligned inner disk as well as the diagnostic value of near infrared interferometry for inner disk geometry.

  14. A multi-resolution model to capture both global fluctuations of an enzyme and molecular recognition in the ligand-binding site

    CERN Document Server

    Fogarty, Aoife C; Kremer, Kurt

    2016-01-01

    In multi-resolution simulations, different system components are simultaneously modelled at different levels of resolution, these being smoothly coupled together. In the case of enzyme systems, computationally expensive atomistic detail is needed in the active site to capture the chemistry of substrate binding. Global properties of the rest of the protein also play an essential role, determining the structure and fluctuations of the binding site; however, these can be modelled on a coarser level. Similarly, in the most computationally efficient scheme only the solvent hydrating the active site requires atomistic detail. We present a methodology to couple atomistic and coarse-grained protein models, while solvating the atomistic part of the protein in atomistic water. This allows a free choice of which protein and solvent degrees of freedom to include atomistically, without loss of accuracy in the atomistic description. This multi-resolution methodology can successfully model stable ligand binding, and we furt...

  15. Anisotropic multi-resolution analysis in 2D, application to long-range correlations in cloud mm-radar fields

    Energy Technology Data Exchange (ETDEWEB)

    Davis, A.B. [Los Alamos National Lab., NM (United States). Space and Remote Sensing Science Group; Clothiaux, E. [Pennsylvania State Univ., University Park, PA (United States). Dept. of Meteorology

    1999-03-01

    Because of Earth`s gravitational field, its atmosphere is strongly anisotropic with respect to the vertical; the effect of the Earth`s rotation on synoptic wind patterns also causes a more subtle form of anisotropy in the horizontal plane. The authors survey various approaches to statistically robust anisotropy from a wavelet perspective and present a new one adapted to strongly non-isotropic fields that are sampled on a rectangular grid with a large aspect ratio. This novel technique uses an anisotropic version of Multi-Resolution Analysis (MRA) in image analysis; the authors form a tensor product of the standard dyadic Haar basis, where the dividing ratio is {lambda}{sub z} = 2, and a nonstandard triadic counterpart, where the dividing ratio is {lambda}{sub x} = 3. The natural support of the field is therefore 2{sup n} pixels (vertically) by 3{sup n} pixels (horizontally) where n is the number of levels in the MRA. The natural triadic basis includes the French top-hat wavelet which resonates with bumps in the field whereas the Haar wavelet responds to ramps or steps. The complete 2D basis has one scaling function and five wavelets. The resulting anisotropic MRA is designed for application to the liquid water content (LWC) field in boundary-layer clouds, as the prevailing wind advects them by a vertically pointing mm-radar system. Spatial correlations are notoriously long-range in cloud structure and the authors use the wavelet coefficients from the new MRA to characterize these correlations in a multifractal analysis scheme. In the present study, the MRA is used (in synthesis mode) to generate fields that mimic cloud structure quite realistically although only a few parameters are used to control the randomness of the LWC`s wavelet coefficients.

  16. SmartShadow models and methods for pervasive computing

    CERN Document Server

    Wu, Zhaohui

    2013-01-01

    SmartShadow: Models and Methods for Pervasive Computing offers a new perspective on pervasive computing with SmartShadow, which is designed to model a user as a personality ""shadow"" and to model pervasive computing environments as user-centric dynamic virtual personal spaces. Just like human beings' shadows in the physical world, it follows people wherever they go, providing them with pervasive services. The model, methods, and software infrastructure for SmartShadow are presented and an application for smart cars is also introduced.  The book can serve as a valuable reference work for resea

  17. Cosmic Ray Sun Shadow in Soudan 2 Underground Muon Flux

    CERN Document Server

    Allison, W W M; Ayres, D S; Barrett, W L; Bode, C; Border, P M; Brooks, C B; Cobb, J H; Cotton, R J; Courant, H; Demuth, D M; Fields, T H; Gallagher, H R; García-García, C; Goodman, M C; Gran, R; Joffe-Minor, T M; Kafka, T; Kasahara, S M; Leeson, W; Lichtfield, P J; Longley, N P; Mann, W A; Marshak, M L; Milburn, R H; Miller, W H; Mualem, L M; Napier, A; Oliver, W P; Pearce, G F; Peterson, E A; Petyt, D A; Price, L E; Ruddick, K; Sánchez, M; Schneps, J; Schub, M H; Seidlein, R; Stassinakis, A; Thron, J L; Vasilev, V; Villaume, G; Wakely, S P; West, N; Wall, D

    1999-01-01

    The absorption of cosmic rays by the sun produces a shadow at the earth. The angular offset and broadening of the shadow are determined by the magnitude and structure of the interplanetary magnetic field (IPMF) in the inner solar system. We report the first measurement of the solar cosmic ray shadow by detection of deep underground muon flux in observations made during the entire ten-year interval 1989 to 1998. The sun shadow varies significantly during this time, with a $3.3\\sigma$ shadow observed during the years 1995 to 1998.

  18. Implementation of the multiconfiguration time-dependent Hatree-Fock method for general molecules on a multi-resolution Cartesian grid

    CERN Document Server

    Sawada, Ryohto; Ishikawa, Kenichi L

    2016-01-01

    We report a three-dimensional numerical implementation of multiconfiguration time-dependent Hartree-Fock (MCTDHF) based on a multi-resolution Cartesian grid, with no need to assume any symmetry of molecular structure. We successfully compute high-harmonic generation (HHG) of H2 and H2O. The present implementation will open a way to the first-principle theoretical study of intense-field and attosecond-pulse induced ultrafast phenomena in general molecules.

  19. Time-Frequency Feature Representation Using Multi-Resolution Texture Analysis and Acoustic Activity Detector for Real-Life Speech Emotion Recognition

    Directory of Open Access Journals (Sweden)

    Kun-Ching Wang

    2015-01-01

    Full Text Available The classification of emotional speech is mostly considered in speech-related research on human-computer interaction (HCI. In this paper, the purpose is to present a novel feature extraction based on multi-resolutions texture image information (MRTII. The MRTII feature set is derived from multi-resolution texture analysis for characterization and classification of different emotions in a speech signal. The motivation is that we have to consider emotions have different intensity values in different frequency bands. In terms of human visual perceptual, the texture property on multi-resolution of emotional speech spectrogram should be a good feature set for emotion classification in speech. Furthermore, the multi-resolution analysis on texture can give a clearer discrimination between each emotion than uniform-resolution analysis on texture. In order to provide high accuracy of emotional discrimination especially in real-life, an acoustic activity detection (AAD algorithm must be applied into the MRTII-based feature extraction. Considering the presence of many blended emotions in real life, in this paper make use of two corpora of naturally-occurring dialogs recorded in real-life call centers. Compared with the traditional Mel-scale Frequency Cepstral Coefficients (MFCC and the state-of-the-art features, the MRTII features also can improve the correct classification rates of proposed systems among different language databases. Experimental results show that the proposed MRTII-based feature information inspired by human visual perception of the spectrogram image can provide significant classification for real-life emotional recognition in speech.

  20. ROBUST MOTION SEGMENTATION FOR HIGH DEFINITION VIDEO SEQUENCES USING A FAST MULTI-RESOLUTION MOTION ESTIMATION BASED ON SPATIO-TEMPORAL TUBES

    OpenAIRE

    Brouard, Olivier; Delannay, Fabrice; Ricordel, Vincent; Barba, Dominique

    2007-01-01

    4 pages; International audience; Motion segmentation methods are effective for tracking video objects. However, objects segmentation methods based on motion need to know the global motion of the video in order to back-compensate it before computing the segmentation. In this paper, we propose a method which estimates the global motion of a High Definition (HD) video shot and then segments it using the remaining motion information. First, we develop a fast method for multi-resolution motion est...

  1. Multi-resolutional Medial Axis Generation for Solid Models%实体模型的多分辨率中轴生成

    Institute of Scientific and Technical Information of China (English)

    朱厚盛; 刘玉生

    2015-01-01

    According to the requirement of the dimensionality reduction of solid models, a multi-resolution medial axis generation method is proposed for solid models. According to different model levels, the parts of the model that need to be refined are found out first. Then, the boundary is voxelized with the help of the results. After that, the distances of the multi-resolution voxels are computed by distance dilation method. Finally, the multi-resolution medial axis voxels are computed according to the distances of voxels. Several groups of experiments are given to demonstrate that the multi-resolution medial axis of high quality can be generated with low time and space cost using the proposed method.%针对模型降维的需要,提出一种实体模型的多分辨率中轴生成方法。首先根据模型的层次寻找模型中需要细化的部分,并据此对边界进行体素化;其次使用距离蔓延的方法计算多分辨率体素的距离;最后根据体素的距离计算出多分辨率的中轴体素。实验结果表明,该方法可以以低时间空间代价生成高质量的多分辨率中轴。

  2. Moving Shadow Detection and Removal for Traffic Sequences

    Institute of Scientific and Technical Information of China (English)

    Mei Xiao; Chong-Zhao Han; Lei Zhang

    2007-01-01

    Segmentation of moving objects in a video sequence is a basic task for application of computer vision. However, shadows extracted along with the objects can result in large errors in object localization and recognition. In this paper, we propose a method of moving shadow detection based on edge information, which can effectively detect the cast shadow of a moving vehicle in a traffic scene. Having confirmed shadows existing in a figure, we execute the shadow removal algorithm proposed in this paper to segment the shadow from the foreground. The shadow eliminating algorithm removes the boundary of the cast shadow and preserves object edges firstly; secondly, it reconstructs coarse object shapes based on the edge information of objects; and finally, it extracts the cast shadow by subtracting the moving object from the change detection mask and performs further processing. The proposed method has been further tested on images taken under different shadow orientations, vehicle colors and vehicle sizes, and the results have revealed that shadows can be successfully eliminated and thus good video segmentation can be obtained.

  3. Shadows of Kerr black holes with and without scalar hair

    CERN Document Server

    Cunha, Pedro V P; Radu, Eugen; Runarsson, Helgi F

    2016-01-01

    For an observer, the Black Hole (BH) shadow is the BH's apparent image in the sky due to the gravitational lensing of nearby radiation, emitted by an external source. A recent class of solutions dubbed Kerr BHs with scalar hair possess smaller shadows than the corresponding Kerr BHs and, under some conditions, novel exotic shadow shapes can arise. Thus, these hairy BHs could potentially provide new shadow templates for future experiments such as the Event Horizon Telescope. In order to obtain the shadows, the backward ray-tracing algorithm is briefly introduced, followed by numerical examples of shadows of Kerr BHs with scalar hair contrasting with the Kerr analogues. Additionally, an analytical solution for the Kerr shadow is derived in closed form for a ZAMO observer at an arbitrary position.

  4. Shadows of Kerr black holes with and without scalar hair

    Science.gov (United States)

    Cunha, Pedro V. P.; Herdeiro, Carlos A. R.; Radu, Eugen; Rúnarsson, Helgi F.

    2016-06-01

    For an observer, the Black Hole (BH) shadow is the BHs apparent image in the sky due to the gravitational lensing of nearby radiation, emitted by an external source. A recent class of solutions dubbed Kerr BHs with scalar hair possess smaller shadows than the corresponding Kerr BHs and, under some conditions, novel exotic shadow shapes can arise. Thus, these hairy BHs could potentially provide new shadow templates for future experiments such as the Event Horizon Telescope. In order to obtain the shadows, the backward ray-tracing algorithm is briefly introduced, followed by numerical examples of shadows of Kerr BHs with scalar hair contrasting with the Kerr analogues. Additionally, an analytical solution for the Kerr shadow is derived in closed form for a ZAMO observer at an arbitrary position.

  5. Are Shadows Only Coarsely Processed? Exploring Depth Discrimination with Cast Shadow Cue Conflicts Across Spatial Frequency

    Directory of Open Access Journals (Sweden)

    P.G Lovell

    2014-08-01

    Full Text Available Shape-from-shading is a ubiquitous cue informing object identification and depth judgements. Cast-shadows contribute towards these judgements (see Mammassian, Knill and Kersten, 1998. A number of studies have reported that search-times for inconsistent shadows vary according to whether the scene is presented as-if illuminated from above or below. Though the direction of these inhomogeneities is sometimes contested (see Rensink and Cavanagh, 2004 and Lovell et al, 2009. Lovell et. al. posit that the processing of shadows is handled by coarse-scale processes, but only in light-from-above presentations. The current study explores depth discrimination judgements informed by cast shadows. We create stimuli featuring a pair of floating discs, casting shadows onto a fronto-parallel surface. Participants were asked to identify the disc protruding the most towards them. One disc featured a cast-shadow with a cue-conflict, where low and high spatial-frequency components conveyed different depth information. This allowed us to estimate the weight assigned to the different cues when depth discrimination judgements were made. Firstly, we find that depth judgements consistently reflected the coarse-scale cues, fine-scale cues were largely ignored. Secondly, we found only small differences in the cue weightings for stimuli presented as-if light were above or below. The latter result is perplexing as previous studies have shown a difference between light-from-above and below conditions. We speculate that this difference reflects the task undertaken, i.e. discriminating depths rather than searching for odd shadows.

  6. Nuclear Shadowing at Small Values of X.

    Science.gov (United States)

    Qiu, Jian-Wei

    The nuclear parton distributions are given in a model where the nucleus is viewed as a collection of uncorrelated nucleons. Using these distributions, we determine nuclear shadowing at small values of x. We find that the effect of nuclear shadowing goes away very slowly when Q^2 increases. Our results are consistent with the experiment of Goodman et al. Using these distributions, we also determine the A-dependence of hadronic charm productions. Defining total cross sections of hadronic charm production in pA and pp collisions as sigma_{rm pAto c | c} = A^alpha sigma_{rm ppto c| c}, we find that alpha is bigger than 0.96 for all physically existing nuclei at present collider energies.

  7. Numerical shadow and geometry of quantum states

    Energy Technology Data Exchange (ETDEWEB)

    Dunkl, Charles F [Department of Mathematics, University of Virginia, Charlottesville, VA 22904-4137 (United States); Gawron, Piotr; Miszczak, Jaroslaw A; Puchala, Zbigniew [Institute of Theoretical and Applied Informatics, Polish Academy of Sciences, Baltycka 5, 44-100 Gliwice (Poland); Holbrook, John A [Department of Mathematics and Statistics, University of Guelph, Guelph, Ontario N1G 2W1 (Canada); Zyczkowski, Karol, E-mail: cfd5z@virginia.edu, E-mail: gawron@iitis.pl, E-mail: jholbroo@uoguelph.ca, E-mail: miszczak@iitis.pl, E-mail: z.puchala@iitis.pl, E-mail: karol@tatry.if.uj.edu.pl [Institute of Physics, Jagiellonian University, Reymonta 4, 30-059 Krakow (Poland)

    2011-08-19

    The totality of normalized density matrices of dimension N forms a convex set Q{sub N} in R{sup N2-1}. Working with the flat geometry induced by the Hilbert-Schmidt distance, we consider images of orthogonal projections of Q{sub N} onto a two-plane and show that they are similar to the numerical ranges of matrices of dimension N. For a matrix A of dimension N, one defines its numerical shadow as a probability distribution supported on its numerical range W(A), induced by the unitarily invariant Fubini-Study measure on the complex projective manifold CP{sup N-1}. We define generalized, mixed-state shadows of A and demonstrate their usefulness to analyse the structure of the set of quantum states and unitary dynamics therein.

  8. Numerical shadow and geometry of quantum states

    CERN Document Server

    Dunkl, Charles F; Holbrook, John A; Miszczak, Jarosław A; Puchała, Zbigniew; Życzkowski, Karol

    2011-01-01

    The totality of normalised density matrices of order N forms a convex set Q_N in R^(N^2-1). Working with the flat geometry induced by the Hilbert-Schmidt distance we consider images of orthogonal projections of Q_N onto a two-plane and show that they are similar to the numerical ranges of matrices of order N. For a matrix A of a order N one defines its numerical shadow as a probability distribution supported on its numerical range W(A), induced by the unitarily invariant Fubini-Study measure on the complex projective manifold CP^(N-1). We define generalized, mixed-states shadows of A and demonstrate their usefulness to analyse the structure of the set of quantum states and unitary dynamics therein.

  9. Scaling and shadowing effects in ballistic aggregation

    Science.gov (United States)

    Joag, P. S.; Limaye, A. V.; Amritkar, R. E.

    1987-10-01

    We have studied the scaling and shadowing properties of two-dimensional off-lattice ballistic aggregation on a seed. The computer simulations show that the limiting semivertical cone angle is about 15.5°. The density as a function of distance from the seed tends to a constant value showing a basic two-dimensional nature of the aggregates and has a correction with a metadimension of about 0.56. The density as a function of angle near the edges of the cone is found to obey a scaling relation similar to the on-lattice case. The probabilities for the fingers of different lengths which shadow the particle near the edge are determined in the computer experiment and also determined analytically.

  10. Initial conditions from the shadowed Glauber model

    CERN Document Server

    Chatterjee, Sandeep; Ghosh, Snigdha; Hasanujjaman, Md; Alam, Jane; Sarkar, Sourav

    2015-01-01

    The two component Monte-Carlo Glauber model predicts a knee-like structure in the centrality dependence of elliptic flow $v_2$ in Uranium+Uranium collisions at $\\sqrt{s_{\\rm NN}}=193$ GeV. It also produces a strong anti-correlation between $v_2$ and $dN_{ch}/dy$ in the case of top ZDC events. However, none of these features have been observed in data. We address these discrepancies by including the effect of nucleon shadowing to the two component Monte-Carlo Glauber model. Apart from addressing successfully the above issues, we find that the nucleon shadow suppresses the event by event fluctuation of various quantities, e.g. $\\varepsilon_2$ which is in accordance with expectation from the dynamical models of initial condition based on gluon saturation physics.

  11. Fading and Shadowing in Wireless Systems

    CERN Document Server

    Shankar, P Mohana

    2012-01-01

    In recent decades, growth in the field of wireless communications has led to an exponential rise in the number of journals catering to the research community. Still unmet, however, is the need to fully and comprehensively understand the effects of channel degradation brought on by the statistical fluctuations in the channel. These fluctuations mainly manifest as variations in signal power observed in the channel generally modeled using a variety of probability distributions, both in straight forms as well as in compound forms. While the former might explain some of the effects, it is the latter, namely, the compound models, which incorporate both short term and long term power fluctuations in the channel, explain the much more complex nature of the signals in these channels. Fading and Shadowing in Wireless Systems offers a pedagogical approach to the topic, with insight into the modeling and analysis of fading and shadowing. Beginning with statistical background and digital communications, the book is formul...

  12. Shadow price in the power utility case

    OpenAIRE

    Attila Herczegh; Vilmos Prokaj

    2011-01-01

    We consider the problem of maximizing expected power utility from consumption over an infinite horizon in the Black–Scholes model with proportional transaction costs, as studied in Shreve and Soner [ Ann. Appl. Probab. 4 (1994) 609–692]. ¶ Similar to Kallsen and Muhle-Karbe [ Ann. Appl. Probab. 20 (2010) 1341–1358], we derive a shadow price, that is, a frictionless price process with values in the bid-ask spread which leads to the same optimal policy.

  13. "Shadow Banking: Policy Challenges for Central Banks"

    OpenAIRE

    Moe, Thorvald Grung

    2014-01-01

    Central banks responded with exceptional liquidity support during the financial crisis to prevent a systemic meltdown. They broadened their tool kit and extended liquidity support to nonbanks and key financial markets. Many want central banks to embrace this expanded role as "market maker of last resort" going forward. This would provide a liquidity backstop for systemically important markets and the shadow banking system that is deeply integrated with these markets. But how much liquidity su...

  14. Black Hole Shadows and VSOP-2

    Science.gov (United States)

    Takahashi, R.

    2009-08-01

    The radio images in the galactic center with micro-arcsecond resolution will be obtained by the radio interferometer VSOP-2. The apparent sizes of the direct images of the black holes in the nearby massive galaxies such as M87 and Sgr A* also have micro-arcsecond scales, and such black holes will be seen as the shadows in the luminous accreting matter around the black holes. At 43 GHz where VSOP-2 has the highest spatial resolution (38 μarcseconds), the observed images of Sgr A* are smeared out by the interstellar scattering. Therefore, the shadow of Sgr A* will not be resolved at this frequency. In the case of M87, the observed values of the black hole mass and the distance are not precisely determined. The possible minimum angular size of the highest spatial resolution of VSOP-2 corresponds to 12.5 GMBH/c^2 which is smaller than the shadow size of the slowly rotating black hole in the accretion flow with the inner edge of the marginally stable orbit. On the other hand, the possible maximum angular size of the highest spatial resolution of VSOP-2 corresponds to 38.1 GMBH/c^2. In this case, for any value of the black hole spin and the observed inclination angle, the size of the black hole shadow is smaller than the highest spatial resolution of VSOP-2. On the other hand, the observed energy spectrum of the accretion flow in M87 is consistent with the radiatively inefficient accretion flow where the electron temperature is higher than the detection temperature of VSOP-2. This means that the photons from the accretion flow around the black hole in M87 can be detected by VSOP-2. Other related issues are also discussed.

  15. The shadow of a naked singularity

    CERN Document Server

    Ortiz, Néstor; Zannias, Thomas

    2015-01-01

    We analyze the redshift suffered by photons originating from an external source, traversing a collapsing dust cloud and finally received by an asymptotic observer. In addition, we study the shadow that the collapsing cloud casts on the sky of the asymptotic observer. We find that the resulting redshift and properties of the shadow depend crucially on whether the final outcome of the complete gravitational collapse is a black hole or a naked singularity. In the black hole case, the shadow is due to the high redshift acquired by the photons as they approach the event horizon, implying that their energy is gradually redshifted towards zero within a few crossing times associated with the event horizon radius. In contrast to this, a naked singularity not only absorbs photons originating from the source, but it also emits infinitely redshifted photons with and without angular momenta. This emission introduces an abrupt cut-off in the frequency shift of the photons detected in directions close to the radial one, and...

  16. Aftershocks halted by static stress shadows

    Science.gov (United States)

    Toda, Shinji; Stein, Ross S.; Beroza, Gregory C.; Marsan, David

    2012-06-01

    Earthquakes impart static and dynamic stress changes to the surrounding crust. Sudden fault slip causes small but permanent--static--stress changes, and passing seismic waves cause large, but brief and oscillatory--dynamic--stress changes. Because both static and dynamic stresses can trigger earthquakes within several rupture dimensions of a mainshock, it has proven difficult to disentangle their contributions to the triggering process. However, only dynamic stress can trigger earthquakes far from the source, and only static stress can create stress shadows, where the stress and thus the seismicity rate in the shadow area drops following an earthquake. Here we calculate the stress imparted by the magnitude 6.1 Joshua Tree and nearby magnitude 7.3 Landers earthquakes that occurred in California in April and June 1992, respectively, and measure seismicity through time. We show that, where the aftershock zone of the first earthquake was subjected to a static stress increase from the second, the seismicity rate jumped. In contrast, where the aftershock zone of the first earthquake fell under the stress shadow of the second and static stress dropped, seismicity shut down. The arrest of seismicity implies that static stress is a requisite element of spatial clustering of large earthquakes and should be a constituent of hazard assessment.

  17. PCAC and shadowing of low energy neutrinos

    Science.gov (United States)

    Kopeliovich, B. Z.

    2005-02-01

    The Adler relation between reactions initiated by neutrinos and pions is easy to misinterpret as a manifestation of the pion pole dominance. An axial current, however, cannot fluctuate into a pion, but only to heavy axial-vector states, since the lepton current is transverse. This is the miracle of the PCAC hypothesis which dictates a specific conspiracy between the heavy fluctuations, so that all together they mock the pion pole. Indeed, the observed Q2 dependence of the axial form factor is controlled by the effective mass m˜1 GeV, rather than the pion mass. On the contrary, the onset of nuclear shadowing is governed by the small pion mass, rather than by the large axial mass scale. This is in variance with the conventional wisdom which equates the fluctuation lifetime and the coherence time. For the case of axial current they are different by almost two orders of magnitude. As a result, neutrino interactions are shadowed at very low energies of few hundred MeV, while energy of about 10 GeV is needed to access nuclear shadowing for the vector current. On the contrary to naive expectations, nuclear absorption enhances, rather than suppresses the cross section of coherent neutrino-production of pions which is the strongest channel (half of the total cross section) in the black disc limit.

  18. Perception of shadows in children with autism spectrum disorders.

    Directory of Open Access Journals (Sweden)

    Cristina Becchio

    Full Text Available BACKGROUND: Cast shadows in visual scenes can have profound effects on visual perception. Much as they are informative, they also constitute noise as they are salient features of the visual scene potentially interfering with the processing of other features. Here we asked i whether individuals with autism can exploit the information conveyed by cast shadows; ii whether they are especially sensitive to noise aspects of shadows. METHODOLOGY/PRINCIPAL FINDINGS: Twenty high-functioning children with autism and twenty typically developing children were asked to recognize familiar objects while the presence, position, and shape of the cast shadow were systematically manipulated. Analysis of vocal reaction time revealed that whereas typically developing children used information from cast shadows to improve object recognition, in autistic children the presence of cast shadows--either congruent or incongruent--interfered with object recognition. Critically, vocal reaction times were faster when the object was presented without a cast shadow. CONCLUSIONS/SIGNIFICANCE: We conclude that shadow-processing mechanisms are abnormal in autism. As a result, processing shadows becomes costly and cast shadows interfere rather than help object recognition.

  19. Infant Perception of Incongruent Shapes in Cast Shadows

    Directory of Open Access Journals (Sweden)

    Kazuki Sato

    2015-04-01

    Full Text Available A cast shadow occurs when an object blocks the light from an illumination and projects a dark region onto a surface. Previous studies have reported that adults are slower to identify an object when the object has an incongruent cast shadow than when it has a congruent cast shadow (Castiello, 2001. Here, we used the familiarization-novelty preference procedure to examine whether 5- to 8-month-old infants could detect the relationship between object shapes and cast shadows. In Experiment 1, we examined the infants' ability to detect incongruency between objects and cast shadows. Results showed that 7- to 8-month olds could detect incongruence between the object shapes and the cast shadows, whereas 5- to 6-month olds did not. Yet, our control experiment showed that infants could not detect this incongruence from stimuli in which a white outline had been added to the original cast shadow to decrease the possibility of it being perceived as a cast shadow (Experiment 2. The results of these experiments demonstrate that 7- to 8-month olds responded to the congruence of cast shadows and to consistent contrast polarity between the cast shadow and its background.

  20. Phylogenetic Trees From Sequences

    Science.gov (United States)

    Ryvkin, Paul; Wang, Li-San

    In this chapter, we review important concepts and approaches for phylogeny reconstruction from sequence data.We first cover some basic definitions and properties of phylogenetics, and briefly explain how scientists model sequence evolution and measure sequence divergence. We then discuss three major approaches for phylogenetic reconstruction: distance-based phylogenetic reconstruction, maximum parsimony, and maximum likelihood. In the third part of the chapter, we review how multiple phylogenies are compared by consensus methods and how to assess confidence using bootstrapping. At the end of the chapter are two sections that list popular software packages and additional reading.

  1. Phylogenetic lineages in Entomophthoromycota

    NARCIS (Netherlands)

    Gryganskyi, A.P.; Humber, R.A.; Smith, M.E.; Hodge, K.; Huang, B.; Voigt, K.; Vilgalys, R.

    2013-01-01

    Entomophthoromycota is one of six major phylogenetic lineages among the former phylum Zygomycota. These early terrestrial fungi share evolutionarily ancestral characters such as coenocytic mycelium and gametangiogamy as a sexual process resulting in zygospore formation. Previous molecular studies ha

  2. Direct 3D printed shadow mask on Silicon

    Science.gov (United States)

    Rahiminejad, S.; Köhler, E.; Enoksson, P.

    2016-10-01

    A 3D printed shadow mask method is presented. The 3D printer prints ABS plastic directly on the wafer, thus avoiding gaps between the wafer and the shadow mask, and deformation during the process. The wafer together with the 3D printed shadow mask was sputtered with Ti and Au. The shadow mask was released by immersion in acetone. The sputtered patches through the shadow mask were compared to the opening of the 3D printed shadow mask and the design dimensions. The patterned Au patches were larger than the printed apertures, however they were smaller than the design widths. The mask was printed in 4 min, the cost is less than one euro cent, and the process is a low temperature process suitable for temperature sensitive components.

  3. Clustered deep shadow maps for integrated polyhedral and volume rendering

    KAUST Repository

    Bornik, Alexander

    2012-01-01

    This paper presents a hardware-accelerated approach for shadow computation in scenes containing both complex volumetric objects and polyhedral models. Our system is the first hardware accelerated complete implementation of deep shadow maps, which unifies the computation of volumetric and geometric shadows. Up to now such unified computation was limited to software-only rendering . Previous hardware accelerated techniques can handle only geometric or only volumetric scenes - both resulting in the loss of important properties of the original concept. Our approach supports interactive rendering of polyhedrally bounded volumetric objects on the GPU based on ray casting. The ray casting can be conveniently used for both the shadow map computation and the rendering. We show how anti-aliased high-quality shadows are feasible in scenes composed of multiple overlapping translucent objects, and how sparse scenes can be handled efficiently using clustered deep shadow maps. © 2012 Springer-Verlag.

  4. Shadow of a charged rotating non-commutative black hole

    Energy Technology Data Exchange (ETDEWEB)

    Sharif, M. [University of the Punjab, Department of Mathematics, Lahore (Pakistan); Pakistan Academy of Sciences, Islamabad (Pakistan); Iftikhar, Sehrish [University of the Punjab, Department of Mathematics, Lahore (Pakistan)

    2016-11-15

    This paper investigates the shadow of a charged rotating non-commutative black hole. For this purpose, we first formulate the null geodesics and study the effects of a non-commutative charge on the photon orbit. We then explore the effect of spin, angle of inclination as well as non-commutative charge on the silhouette of the shadow. It is found that shape of the shadow deviates from the circle with the decrease in the non-commutative charge. We also discuss observable quantities to study the deformation and distortion in the shadow cast by the black hole which decreases for small values of a non-commutative charge. Finally, we study the shadows in the presence of plasma. We conclude that the non-commutativity has a great impact on the black hole shadow. (orig.)

  5. The shadow of black holes an analytic description

    CERN Document Server

    Grenzebach, Arne

    2016-01-01

    This book introduces an analytic method to describe the shadow of black holes. As an introduction, it presents a survey of the attempts to observe the shadow of galactic black holes. Based on a detailed discussion of the Plebański–Demiański class of space-times, the book derives analytical formulas for the photon regions and for the boundary curve of the shadow as seen by an observer in the domain of outer communication. It also analyzes how the shadow depends on the motion of the observer. For all cases, the photon regions and shadows are visualized for various values of the parameters. Finally, it considers how the analytical formulas can be used for calculating the horizontal and vertical angular diameters of the shadow, and estimates values for the black holes at the centers of our Galaxy near Sgr A* and of the neighboring galaxy M87.

  6. Shadow of a Charged Rotating Non-Commutative Black Hole

    CERN Document Server

    Sharif, M

    2016-01-01

    This paper investigates the shadow of a charged rotating non-commutative black hole. For this purpose, we first formulate the null geodesics and study the effects of non-commutative charge on the photon orbit. We then explore the effect of spin, angle of inclination as well as non-commutative charge on the silhouette of the shadow. It is found that shape of the shadow deviates from the circle with the decrease in the non-commutative charge. We also discuss observable quantities to study the deformation and distortion in the shadow cast by the black hole which decreases for small values of non-commutative charge. Finally, we study the shadows in the presence of plasma. We conclude that the non-commutativity has a great impact on the black hole shadow.

  7. A method of shadow puppet figure modeling and animation

    Institute of Scientific and Technical Information of China (English)

    Xiao-fang HUANG; Shou-qian SUN; Ke-jun ZHANG; Tian-ning XU; Jian-feng WU; Bin ZHU

    2015-01-01

    To promote the development of the intangible cultural heritage of the world, shadow play, many studies have focused on shadow puppet modeling and interaction. Most of the shadow puppet figures are still imaginary, spread by ancients, or carved and painted by shadow puppet artists, without consideration of real dimensions or the appearance of human bodies. This study proposes an algorithm to transform 3D human models to 2D puppet figures for shadow puppets, including automatic location of feature points, automatic segmentation of 3D models, automatic extraction of 2D contours, automatic clothes matching, and animation. Experiment proves that more realistic and attractive figures and animations of the shadow puppet can be generated in real time with this algorithm.

  8. Satellite images analysis for shadow detection and building height estimation

    Science.gov (United States)

    Liasis, Gregoris; Stavrou, Stavros

    2016-09-01

    Satellite images can provide valuable information about the presented urban landscape scenes to remote sensing and telecommunication applications. Obtaining information from satellite images is difficult since all the objects and their surroundings are presented with feature complexity. The shadows cast by buildings in urban scenes can be processed and used for estimating building heights. Thus, a robust and accurate building shadow detection process is important. Region-based active contour models can be used for satellite image segmentation. However, spectral heterogeneity that usually exists in satellite images and the feature similarity representing the shadow and several non-shadow regions makes building shadow detection challenging. In this work, a new automated method for delineating building shadows is proposed. Initially, spectral and spatial features of the satellite image are utilized for designing a custom filter to enhance shadows and reduce intensity heterogeneity. An effective iterative procedure using intensity differences is developed for tuning and subsequently selecting the most appropriate filter settings, able to highlight the building shadows. The response of the filter is then used for automatically estimating the radiometric property of the shadows. The customized filter and the radiometric feature are utilized to form an optimized active contour model where the contours are biased to delineate shadow regions. Post-processing morphological operations are also developed and applied for removing misleading artefacts. Finally, building heights are approximated using shadow length and the predefined or estimated solar elevation angle. Qualitative and quantitative measures are used for evaluating the performance of the proposed method for both shadow detection and building height estimation.

  9. Multi-features Based Approach for Moving Shadow Detection

    Institute of Scientific and Technical Information of China (English)

    ZHOU Ning; ZHOU Man-li; XU Yi-ping; FANG Bao-hong

    2004-01-01

    In the video-based surveillance application, moving shadows can affect the correct localization and detection of moving objects. This paper aims to present a method for shadow detection and suppression used for moving visual object detection. The major novelty of the shadow suppression is the integration of several features including photometric invariant color feature, motion edge feature, and spatial feature etc. By modifying process for false shadow detected, the averaging detection rate of moving object reaches above 90% in the test of Hall-Monitor sequence.

  10. Numerical shadows: measures and densities on the numerical range

    CERN Document Server

    Dunkl, Charles F; Holbrook, John A; Puchała, Zbigniew; Zyczkowski, Karol \\

    2010-01-01

    For any operator $M$ acting on an $N$-dimensional Hilbert space $H_N$ we introduce its numerical shadow, which is a probability measure on the complex plane supported by the numerical range of $M$. The shadow of $M$ at point $z$ is defined as the probability that the inner product $(Mu,u)$ is equal to $z$, where $u$ stands for a random complex vector from $H_N$, satisfying $||u||=1$. In the case of N=2 the numerical shadow of a non-normal operator can be interpreted as a shadow of a hollow sphere projected on a plane. A similar interpretation is provided also for higher dimensions. For a hermitian $M$ its numerical shadow forms a probability distribution on the real axis which is shown to be a one dimensional $B$-spline. In the case of a normal $M$ the numerical shadow corresponds to a shadow of a transparent solid simplex in $R^{N-1}$ onto the complex plane. Numerical shadow is found explicitly for Jordan matrices $J_N$, direct sums of matrices and in all cases where the shadow is rotation invariant. Results...

  11. Shadow Detection and Compensation for Color Aerial Images

    Institute of Scientific and Technical Information of China (English)

    WANG Shugen; GUO Zejin; LI Deren

    2003-01-01

    A method for shadow detection and compensation for color aerial images is presented. It is considered that the intensity value of each image pixel is the product of illumination function and ground object reflection, and the shadowed regions on the image are mainly caused by the short of illumination, so the information compensation for the shadowed regions should concentrate on the illumination adjustment of concerned area on the basis of the analysis of whole image. The shadow detection and compensation procedure proposed by this paper consists of four steps.

  12. Field investigation of the drift shadow

    Energy Technology Data Exchange (ETDEWEB)

    Su, Grace W.; Kneafsey, Timothy J.; Ghezzehei, Teamrat A.; Marshall, Brian D.; Cook, Paul J.

    2005-09-08

    A drift shadow is an area immediately beneath an undergroundvoidthat, in theory, will be relatively drier than the surrounding rockmass. Numerical and analytical models of water flow through unsaturatedrock predict the existence of a drift shadow, but field tests confirmingits existence have yet to be performed. Proving the existence of driftshadows and understanding their hydrologic and transport characteristicscould provide a better understanding of how contaminants move in thesubsurface if released from waste emplacement drifts such as the proposednuclear waste repository at Yucca Mountain, Nevada. We describe the fieldprogram that will be used to investigate the existence of a drift shadowand the corresponding hydrological process at the Hazel-Atlas silica-sandmine located at the Black Diamond Mines Regional Preserve in Antioch,California. The location and configuration of this mine makes it anexcellent site to observe and measure drift shadow characteristics. Themine is located in a porous sandstone unit of the Domengine Formation, anapproximately 230 meter thick series of interbedded Eocene-age shales,coals, and massive-bedded sandstones. The mining method used at the minerequired the development of two parallel drifts, one above the other,driven along the strike of the mined sandstone stratum. Thisconfiguration provides the opportunity to introduce water into the rockmass in the upper drift and to observe and measure its flow around theunderlying drift. The passive and active hydrologic tests to be performedare described. In the passive method, cores will be obtained in a radialpattern around a drift and will be sectioned and analyzed for in-situwater content and chemical constituents. With the active hydrologic test,water will be introduced into the upper drift of the two parallel driftsand the flow of the water will be tracked as it passes near the bottomdrift. Tensiometers, electrical resistance probes, neutron probes, andground penetrating radar may be

  13. A Global Search for Stress Shadows

    Science.gov (United States)

    Mallman, E. P.; Parsons, T.

    2004-12-01

    For years scientists have recognized a decrease in seismicity in the regions surrounding the 1857 Fort Tejon and 1906 San Francisco earthquakes in California. This decrease in seismicity has since been correlated with calculated Coulomb stress decrease and termed a stress shadow. Earthquake hazard assessments increasingly incorporate probability perturbations resulting from calculated static stress changes. However, some researchers have questioned the existence of stress shadows when detailed studies of seismicity rates following other earthquakes failed to show correlations between calculated stress decreases and seismicity rate decreases. Regions of decreased seismicity rate are difficult to find compared with rate-increased regions; we thus look for evidence of post-seismic stress rotations, which are easier to detect, require none of the assumptions inherent to static stress calculations, and are a necessary condition for the occurrence of a stress shadow zone. A stress rotation, as determined by comparison of focal mechanisms before and after the mainshock, indicates a changed regional stress state that suppresses events of a certain mechanism and enhances events of a differing mechanism. To independently test the shadow hypothesis, we examined a global catalog of 119 M>7 earthquakes and the events within a 2-degree radius around them that were recorded by the Harvard CMT catalog. We first examined the average mechanism before and after the mainshock, and then compared this with the changes in rate of each of the mechanisms. Of the 119 mainshocks that we identified, 15 showed a rotation of average mechanism following the mainshock that was significant at the 1-sigma level relative to the observed pre-mainshock variability. Of these 15 events, only 2 did not show increases in rate across all mechanisms. That is, only 2 of the 119 show a decrease in at least one mechanism following the mainshock, and also show a significant rotation in mean mechanism. It is

  14. Glory 'in the shadow of the rainbow'

    CERN Document Server

    Ueda, M; Hussein, M S; Takigawa, N

    1999-01-01

    We show that the angular distribution of the nuclear scattering amplitude behaves like the zeroth-order Bessel function with a fixed frequency at extremely forward angles even if there exists no genuine forward glory scattering. A semiclassical interpretation of this behaviour is provided in terms of the effect of scattering in the shadow of the nuclear rainbow. We also argue that the bombarding energy dependence of the amplitude of the sum-of-difference cross section at very small angles provides a possibility to judge whether genuine forward nuclear glory scattering is taking place or not.

  15. Daisy Shadow upon the Great Gatsby

    Institute of Scientific and Technical Information of China (English)

    宋智慧

    2016-01-01

    The Great Gatsby is a significant classic in American literature. The Great Gatsby tells the love story between young Gatsby and rich Daisy. From the moment they loved each other, they cherished their pure love; to the moment Daisy hurt Gatsby twice, fragile love and crushed American dream came into their life, which indirectly led to Gatsby's death. Daisy Shadow has swallowed Gatsby's soul and destroyed his whole life. The sarcasm of the novel also makes people try best to find a good or proper ending to Gatsby, while so many possibilities lead to nothing proper.

  16. Horndeski/Galileon black hole shadows

    CERN Document Server

    Tretyakova, D A

    2016-01-01

    We examine observational signatures of the asymptotically de Sitter branch of static spherically symmetric Horndeski/Galileon solutions. Our analysis reveales that possible deviations of the photon sphere size from those of the GR Schwarzshild solution are vanishing compared to the resolution of modern radio-interferometric observations. These deviations are heavily suppressed by the bounds coming from the weak-field observation. We conclude that shadow size would not be a useful characteristic to distinguish the Horndeski/Galileon static spherically symmetric spacetimes in the foreseeable future.

  17. Phylogenetic shadowing and computational identification of human microRNA genes

    NARCIS (Netherlands)

    Berezikov, Eugene; Guryev, Victor; van de Belt, José; Wienholds, Erno; Plasterk, Ronald H A; Cuppen, Edwin

    2005-01-01

    We sequenced 122 miRNAs in 10 primate species to reveal conservation characteristics of miRNA genes. Strong conservation is observed in stems of miRNA hairpins and increased variation in loop sequences. Interestingly, a striking drop in conservation was found for sequences immediately flanking the m

  18. In the shadow of phylogenetic uncertainty: the recent diversification of Lysandra butterflies through chromosomal change.

    Science.gov (United States)

    Talavera, Gerard; Lukhtanov, Vladimir A; Rieppel, Lukas; Pierce, Naomi E; Vila, Roger

    2013-12-01

    The phylogeny of the butterfly genus Lysandra (Lycaenidae, Polyommatinae) has been intractable using both molecular and morphological characters, which could be a result of speciation due to karyotype instability. Here we reconstruct the phylogeny of the group using multi-locus coalescent-based methods on seven independent genetic markers. While the genus is ca. 4.9 Mya old, the diversification of the extant lineages was extremely recent (ca. 1.5 Mya) and involved multiple chromosomal rearrangements. We find that relationships are uncertain due to both incomplete lineage sorting and hybridization. Minimizing the impact of reticulation in inferring the species tree by testing for mitochondrial introgression events yields a partially resolved tree with three main supported clades: L. punctifera+L. bellargus, the corydonius taxa, and L. coridon+the Iberian taxa, plus three independent lineages without apparently close relatives (L. ossmar, L. syriaca and L. dezina). Based on these results and new karyotypic data, we propose a rearrangement recognizing ten species within the genus. Finally, we hypothesize that chromosomal instability may have played a crucial role in the Lysandra recent diversification. New chromosome rearrangements might be fixed in populations after severe bottlenecks, which at the same time might promote rapid sorting of neutral molecular markers. We argue that population bottlenecks might be a prerequisite for chromosomal speciation in this group.

  19. Phylogenetic shadowing of a histamine-gated chloride channel involved in insect vision.

    Science.gov (United States)

    Iovchev, Mladen; Boutanaev, Alexander; Ivanov, Ivaylo; Wolstenholme, Adrian; Nurminsky, Dmitry; Semenov, Eugene

    2006-01-01

    A recently identified gene, hclA (synonym: ort), codes for an ionotrophic histamine receptor subunit in Drosophila melanogaster, and known hclA mutations lead to defects in the visual system, neurologic disorders and changed responsiveness to neurotoxins. To investigate whether this novel class of receptors is common across the Insecta, we analysed the genomes of 15 other insect species (Diptera, Hymenoptera, Coleoptera, Lepidoptera) and revealed orthologs of hclA in all of them. The predicted receptor domain of HCLA is extensively conserved (86-100% of identity) among the 16 proteins. Minor changes in the amino acid sequence that includes the putative transmembrane domains (TMs) 1-3 were found in non-drosophilid species only. Substantial amino acid variability was observed in the signal polypeptides, the intracellular loop domains and in TM4, in good accordance with known data on sequence variations in ligand-gated ion channels. Pairwise comparisons revealed three consensus sequences for N-glycosylation, conserved in HCLAs of all species studied, as well as a drosophilid-specific putative phosphorylation site. Real-time PCR analysis demonstrated that hclA-mRNA is abundant in heads of adult Drosophila. However, species- and sex-specific variations of the hclA expression levels were also observed.

  20. Phylogenetically resolving epidemiologic linkage.

    Science.gov (United States)

    Romero-Severson, Ethan O; Bulla, Ingo; Leitner, Thomas

    2016-03-08

    Although the use of phylogenetic trees in epidemiological investigations has become commonplace, their epidemiological interpretation has not been systematically evaluated. Here, we use an HIV-1 within-host coalescent model to probabilistically evaluate transmission histories of two epidemiologically linked hosts. Previous critique of phylogenetic reconstruction has claimed that direction of transmission is difficult to infer, and that the existence of unsampled intermediary links or common sources can never be excluded. The phylogenetic relationship between the HIV populations of epidemiologically linked hosts can be classified into six types of trees, based on cladistic relationships and whether the reconstruction is consistent with the true transmission history or not. We show that the direction of transmission and whether unsampled intermediary links or common sources existed make very different predictions about expected phylogenetic relationships: (i) Direction of transmission can often be established when paraphyly exists, (ii) intermediary links can be excluded when multiple lineages were transmitted, and (iii) when the sampled individuals' HIV populations both are monophyletic a common source was likely the origin. Inconsistent results, suggesting the wrong transmission direction, were generally rare. In addition, the expected tree topology also depends on the number of transmitted lineages, the sample size, the time of the sample relative to transmission, and how fast the diversity increases after infection. Typically, 20 or more sequences per subject give robust results. We confirm our theoretical evaluations with analyses of real transmission histories and discuss how our findings should aid in interpreting phylogenetic results.

  1. PCAC and Shadowing of Low Energy Neutrinos

    CERN Document Server

    Kopeliovich, B Z

    2005-01-01

    The Adler relation between reactions initiated by neutrinos and pions is easy to misinterpret as a manifestation of the pion pole dominance. An axial current, however, cannot fluctuate into a pion, but only to heavy axial-vector states, since the lepton current is transverse. This is the miracle of the PCAC hypothesis which dictates a specific conspiracy between the heavy fluctuations, so that all together they mock the pion pole. Indeed, the observed Q^2 dependence of the axial form factor is controlled by the effective mass m_A \\sim 1 GeV, rather than the pion mass. On the contrary, the onset of nuclear shadowing is governed by the small pion mass, rather than by the large axial mass scale. This is in variance with the conventional wisdom which equates the fluctuation lifetime and the coherence time. For the case of axial current they are different by almost two orders of magnitude. As a result, neutrino interactions are shadowed at very low energies of few hundred MeV, while energy of about 10 GeV is neede...

  2. The shadow price of fossil groundwater

    Science.gov (United States)

    Bierkens, Marc F. P.; Reinhard, Stijn; de Bruijn, Jens A.; Wada, Yoshihide

    2017-04-01

    The expansion of irrigated agriculture into areas with limited precipitation and surface water during the growing season has greatly increased the use of fossil groundwater (Wada et al., 2012). As a result, the depletion rate of fossil groundwater resources has shown an increasing rate during the last decades (Wada et al, 2010; Konikow, 2011; Wada et al., 2012; De Graaf et al. 2015; Ritchy et al., 2015). Although water pricing has been used extensively to stimulate efficient application of water to create maximum value (e.g. Medellín-Azuara et al., 2012; Rinaudo et al., 2012; Dinar et al., 2015), it does not preclude the use of non-renewable water resources. Here, we use a global hydrological model and historical crop production and price data to assess the shadow price of non-renewable or fossil groundwater applied to major crops in countries that use large quantities of fossil groundwater. Our results show that shadow prices for many crops are very low, indicating economically inefficient or even wasteful use of fossil groundwater resources. Using India as an example, we show that small changes in the crop mix could lead to large reductions in fossil groundwater use or alternatively, create additional financial means to invest in water saving technologies. Our study thus provides a hydro-economic basis to further the sustainable use of finite groundwater resources.

  3. Self-Attributed Body-Shadows Modulate Tactile Attention

    Science.gov (United States)

    Pavani, Francesco; Galfano, Giovanni

    2007-01-01

    Our body-shadows are special stimuli in the visual world. They often have anatomical resemblance with our own body-parts and move as our body moves, with spatio-temporal correlation. Here, we show that self-attributed body-shadows cue attention to the body-part they refer to, rather than the location they occupy. Using speeded spatial…

  4. Shadow Enhancement in Synthetic Aperture Sonar Using Fixed Focusing

    NARCIS (Netherlands)

    Groen, J.; Hansen, R.E.; Callow, H.J.; Sabel, J.C.; Sæbø, T.O.

    2009-01-01

    Abstract—A shadow cast by an object on the seafloor is important information for target recognition in synthetic aperture sonar (SAS) images. Synthetic aperture imaging causes a fundamental limitation to shadow clarity because the illuminator is moved during the data collection. This leads to a blen

  5. Politics, Time and Space in the Era of Shadow Banking

    DEFF Research Database (Denmark)

    Bryan, Dick; Rafferty, Michael; Wigan, Duncan

    2016-01-01

    In the wake of the Global Financial Crisis, there has been an understandable focus on the financial fragility and contagion aspects of shadow banking. This article argues that shadow banking is important for another set of reasons. It has been well established that shadow banking permits...... the transformation of assets and financial claims. It has also been established that fiscal and regulatory arbitrage occurs through shadow banking, and associated offshore financial activities. The article develops the argument that together these are transforming the times and spaces of modern finance, and directly...... challenging earlier spatio-temporal concepts of finance, and the regulatory/jurisdictional order built on them. The article suggests that the longer term significance of shadow banking may not just be its role in financial crisis, or even tax and regulatory arbitrage, but that it was here that innovative...

  6. Moving Shadows, Moving Sun. Early Modem Sundials Restaging Miracles.

    Science.gov (United States)

    Mersmann, Jasmin

    2015-01-01

    Irrespective of geo- or heliocentric presuppositions, the functioning of sundials is based on the observation of moving shadows or light spots. Even though the cast shadow was often simply used to indicate the time, it could also remind the users of the ephemerality of earthly things or function as an index of planetary movements. This article examines the various ways in which early modem sundials visually interpret the moving shadow or light spot. The instruments address the shadow in inscriptions, integrate it into their design (e.g., in cruciform dials) or even manipulate its course (as in the so-called Horologium Ahaz). Both the crucifix and the Ahaz dials not only refer to astronomical miracles but actually restage them. Even though by means of the horologium it was not possible to explain the Old Testament miracle of the shadow moving backward, adepts were able to recreate it on a terrestrial scale.

  7. Synoptic and mesoscale controls on Sierra Nevada rain shadow intensity

    Science.gov (United States)

    Hatchett, B.; Kaplan, M.; Rutz, J. J.; Garner, C.

    2016-12-01

    The Sierra Nevada of California casts one of the world's greatest rain shadows with windward-leeside precipitation differences approaching an order of magnitude. Leeside rivers and terminal lakes provide critical water resources for ecosystem services and human consumptive use in this water-limited environment. They also offer important archives of paleohydroclimatic change. Understanding the drivers of rain shadow intensity represents an important step in properly evaluating how leeside hydrology will respond to projected climate change and for interpreting increasingly well spatially distributed paleoproxy evidence of past hydroclimates. Recent theoretical and modeling studies have shown rain shadow intensity to be controlled by multiscalar dynamics during storms such as the vertical structure of mountain waves, the presence of mid-level moisture, and position of the warm sector with respect to the mountain crest. Here, we provide a 35-year station-based climatology of strong and weak rain shadow events for the central Sierra Nevada during extended winter (November-April). Wetter (drier) years in leeside basins are characterized by higher (lower) fractions of lee-crest precipitation suggesting weaker (stronger) rain shadow effects during precipitation events. In general, as contributions of precipitation on the climatological top 5% of wet days increases, rain shadow intensity decreases. This suggests a key role for atmospheric rivers in weakening the rain shadow. A separate population of very dry years is found, regardless of number of dry days, when no precipitation is contributed by the climatological top 5% of wet days. These years show stronger rain shadow effects with few exceptions. Using the North American Regional Reanalysis and both surface and satellite-based remote sensing data in conjunction with the derived rain shadow climatology, we demonstrate the additional importance of atmospheric rivers, offshore and upstream mesoscale convection, and

  8. Shadowing Lemma and Chaotic Orbit Determination

    CERN Document Server

    Spoto, Federica

    2015-01-01

    Orbit determination is possible for a chaotic orbit of a dynamical system, given a finite set of observations, provided the initial conditions are at the central time. In a simple discrete model, the standard map, we tackle the problem of chaotic orbit determination when observations extend beyond the predictability horizon. If the orbit is hyperbolic, a shadowing orbit is computed by the least squares orbit determination. We test both the convergence of the orbit determination iterative procedure and the behaviour of the uncertainties as a function of the maximum number $n$ of map iterations observed. When the initial conditions belong to a chaotic orbit, the orbit determination is made impossible by numerical instability beyond a computability horizon, which can be approximately predicted by a simple formula. Moreover, the uncertainty of the results is sharply increased if a dynamical parameter is added to the initial conditions as parameter to be estimated. The uncertainty of the dynamical parameter decrea...

  9. A Scale-Adaptive Approach for Spatially-Varying Urban Morphology Characterization in Boundary Layer Parametrization Using Multi-Resolution Analysis

    Science.gov (United States)

    Mouzourides, P.; Kyprianou, A.; Neophytou, M. K.-A.

    2013-12-01

    Urban morphology characterization is crucial for the parametrization of boundary-layer development over urban areas. One complexity in such a characterization is the three-dimensional variation of the urban canopies and textures, which are customarily reduced to and represented by one-dimensional varying parametrization such as the aerodynamic roughness length and zero-plane displacement . The scope of the paper is to provide novel means for a scale-adaptive spatially-varying parametrization of the boundary layer by addressing this 3-D variation. Specifically, the 3-D variation of urban geometries often poses questions in the multi-scale modelling of air pollution dispersion and other climate or weather-related modelling applications that have not been addressed yet, such as: (a) how we represent urban attributes (parameters) appropriately for the multi-scale nature and multi-resolution basis of weather numerical models, (b) how we quantify the uniqueness of an urban database in the context of modelling urban effects in large-scale weather numerical models, and (c) how we derive the impact and influence of a particular building in pre-specified sub-domain areas of the urban database. We illustrate how multi-resolution analysis (MRA) addresses and answers the afore-mentioned questions by taking as an example the Central Business District of Oklahoma City. The selection of MRA is motivated by its capacity for multi-scale sampling; in the MRA the "urban" signal depicting a city is decomposed into an approximation, a representation at a higher scale, and a detail, the part removed at lower scales to yield the approximation. Different levels of approximations were deduced for the building height and planar packing density . A spatially-varying characterization with a scale-adaptive capacity is obtained for the boundary-layer parameters (aerodynamic roughness length and zero-plane displacement ) using the MRA-deduced results for the building height and the planar packing

  10. Mom's shadow: structure-from-motion in newly hatched chicks as revealed by an imprinting procedure.

    Science.gov (United States)

    Mascalzoni, Elena; Regolin, Lucia; Vallortigara, Giorgio

    2009-03-01

    The ability to recognize three-dimensional objects from two-dimensional (2-D) displays was investigated in domestic chicks, focusing on the role of the object's motion. In Experiment 1 newly hatched chicks, imprinted on a three-dimensional (3-D) object, were allowed to choose between the shadows of the familiar object and of an object never seen before. In Experiments 2 and 3 random-dot displays were used to produce the perception of a solid shape only when set in motion. Overall, the results showed that domestic chicks were able to recognize familiar shapes from 2-D motion stimuli. It is likely that similar general mechanisms underlying the perception of structure-from-motion and the extraction of 3-D information are shared by humans and animals. The present data shows that they occur similarly in birds as known for mammals, two separate vertebrate classes; this possibly indicates a common phylogenetic origin of these processes.

  11. Phylogenetic molecular function annotation

    OpenAIRE

    Engelhardt, Barbara E.; Jordan, Michael I.; Repo, Susanna T; Brenner, Steven E.

    2009-01-01

    It is now easier to discover thousands of protein sequences in a new microbial genome than it is to biochemically characterize the specific activity of a single protein of unknown function. The molecular functions of protein sequences have typically been predicted using homology-based computational methods, which rely on the principle that homologous proteins share a similar function. However, some protein families include groups of proteins with different molecular functions. A phylogenetic ...

  12. Transmit antenna selection based on shadowing side information

    KAUST Repository

    Yilmaz, Ferkan

    2011-05-01

    In this paper, we propose a new transmit antenna selection scheme based on shadowing side information. In the proposed scheme, single transmit antenna which has the highest shadowing coefficient is selected. By the proposed technique, usage of the feedback channel and channel estimation complexity at the receiver can be reduced. We consider independent but not identically distributed Generalized-K composite fading model, which is a general composite fading & shadowing channel model for wireless environments. Exact closed-form outage probability, moment generating function and symbol error probability expressions are derived. In addition, theoretical performance results are validated by Monte Carlo simulations. © 2011 IEEE.

  13. More Efficient Virtual Shadow Maps for Many Lights.

    Science.gov (United States)

    Olsson, Ola; Billeter, Markus; Sintorn, Erik; Kampe, Viktor; Assarsson, Ulf

    2015-06-01

    Recently, several algorithms have been introduced that enable real-time performance for many lights in applications such as games. In this paper, we explore the use of hardware-supported virtual cube-map shadows to efficiently implement high-quality shadows from hundreds of light sources in real time and within a bounded memory footprint. In addition, we explore the utility of ray tracing for shadows from many lights and present a hybrid algorithm combining ray tracing with cube maps to exploit their respective strengths. Our solution supports real-time performance with hundreds of lights in fully dynamic high-detail scenes.

  14. A BRIEF ANALYSIS OF THE SHADOW ECONOMY IN EUROPE

    Directory of Open Access Journals (Sweden)

    Loredana Maftei

    2013-12-01

    Full Text Available Shadow economy affects all country around the world. European countries are affected by undeclared work, under-reporting and tax evasion. This phenomenon increases from West to East, the most affected being the Balkan area. The size of shadow economy is growing due to government actions, such as regulation and tax implementation. From a macroeconomic perspective, the economic cycle sustain the shadow economy levels. To combat this phenomenon it is necessary to adopt electronic payments, to reduce tax implementations and social contributions, to bring encouragement in cash deposits use and broaden credit cards.

  15. The Identification of Internal and External Faults for±800kV UHVDC Transmission Line Using Wavelet based Multi-Resolution Analysis

    Directory of Open Access Journals (Sweden)

    Shu Hongchun

    2011-05-01

    Full Text Available There is a smoothing reactor and DC filter between the inverter and the direct current line to form a boundary in the HVDC transmission system. Since this boundary presents the stop-band characteristic to the high frequency transient voltage signals, the high-frequency transient voltage signal caused by external faults through boundary will be attenuated and the signals caused by internal faults will be unchanged. The wavelet analysis can be used as a tool to extract the feature of the fault to classify the internal fault and the external fault in HVDC transmission system. This paper explores the new method of wavelet based Multi-Resolution Analysis for signal decomposition to classify the difference types fault.

  16. Shadow casted by a twisted and rotating black hole

    CERN Document Server

    Chen, Songbai

    2016-01-01

    Zhang have obtained recently a twisted rotating black hole metric, which is a vacuum solution in four-dimensional Einstein gravity. This black hole solution has a rotation parameter, but without the total angular moment. Here, we have investigated the shadow casted by a twisted rotating black hole. Our results show that the shape of the shadow of the twisted rotating black hole is a standard round disk and does not depend on the inclination angle of the observer. It means that although the twisted rotating black hole has a rotation parameter, its shadow possesses the same behaviors as the common static black hole rather than the usual Kerr-like black holes. Moreover, we find that the marginally circular orbit radius of photon is independent of the direction of photon around the black hole. The value of the marginally circular orbit radius of photon and the size of shadow increase monotonously with the rotation parameter.

  17. Designing large scale chiral metamaterials by nanosphere shadowing lithography

    Science.gov (United States)

    He, Yizhuo; Zhao, Yiping

    2016-09-01

    A scalable nanofabrication technique for chiral metamaterials is presented, which combines the dynamic shadowing growth and self-assembled nanosphere monolayers, and is also known as nanosphere shadowing lithography. We have developed two strategies based on nanosphere shadowing lithography to prepare chiral nanostructures. The first strategy is to create a quasi-three-dimensional single-layer fan-shaped chiral nanostructure on nanospheres with one plasmonic material. The second strategy is to create three-dimensional multi-layers helical nanostructures with one plasmonic material and one dielectric material. Both strategies can produce large-area chiral nanostructures with strong chiral optical response, which makes nanosphere shadowing lithography suitable for producing chiral metamaterial based devices such as an ultrathin narrow-band circular polarizer.

  18. Testing General Relativity with the Shadow Size of Sgr A(*).

    Science.gov (United States)

    Johannsen, Tim; Broderick, Avery E; Plewa, Philipp M; Chatzopoulos, Sotiris; Doeleman, Sheperd S; Eisenhauer, Frank; Fish, Vincent L; Genzel, Reinhard; Gerhard, Ortwin; Johnson, Michael D

    2016-01-22

    In general relativity, the angular radius of the shadow of a black hole is primarily determined by its mass-to-distance ratio and depends only weakly on its spin and inclination. If general relativity is violated, however, the shadow size may also depend strongly on parametric deviations from the Kerr metric. Based on a reconstructed image of Sagittarius A^{*} (Sgr A^{*}) from a simulated one-day observing run of a seven-station Event Horizon Telescope (EHT) array, we employ a Markov chain Monte Carlo algorithm to demonstrate that such an observation can measure the angular radius of the shadow of Sgr A^{*} with an uncertainty of ∼1.5  μas (6%). We show that existing mass and distance measurements can be improved significantly when combined with upcoming EHT measurements of the shadow size and that tight constraints on potential deviations from the Kerr metric can be obtained.

  19. On Risk Charges and Shadow Account Options in Pension Funds

    DEFF Research Database (Denmark)

    Jørgensen, Peter Løchte; Gatzert, Nadine

    2015-01-01

    This paper studies the economic implications of regulatory systems which allow equityholders of pension companies to not only charge a specific premium to compensate them for their higher risk (compared to policyholders), but also to accumulate these risk charges in a so-called shadow account...... in years when they are not immediately payable due to e.g. poor investment results. When surpluses are subsequently reestablished, clearance of the shadow account balance takes priority over bonus/participation transfers to policyholders. We see such a regulatory accounting rule as a valuable option...... to equityholders and our paper develops a model in which the influence of risk charges and shadow account options on stakeholders’ value can be quantified and studied. Our numerical results show that the value of shadow account options can be significant and thus come at the risk of expropriating policyholder...

  20. On Risk Charges and Shadow Account Options in Pension Funds

    DEFF Research Database (Denmark)

    Jørgensen, Peter Løchte; Gatzert, Nadine

    This paper studies the economic implications of regulatory systems which allow equityholders of pension companies to not only charge a specific premium to compensate them for their higher risk (compared to policyholders), but also to accumulate these risk charges in a so-called shadow account...... in years when they are not immediately payable due to e.g. poor investment results. When surpluses are subsequently re-established, clearance of the shadow account balance takes priority over bonus/participation transfers to policyholders. We see such a regulatory accounting rule as a valuable option...... to equityholders and our paper develops a model in which the influence of risk charges and shadow account options on stakeholders' value can be quantified and studied. Our numerical results show that the value of shadow account options can be significant and thus come at the risk of expropriating policyholder...

  1. Nuclear Shadowing in the Light-Cone Dipole Approach

    CERN Document Server

    Nemchik, J

    2008-01-01

    We study nuclear shadowing at small Bjorken x < 0.01 in the color dipole approach. Such a light-cone quantum-chromodynamics formalism based on the Green function technique incorporates naturally color transparency and coherence length effects. The nuclear shadowing for the barq-q Fock component of the photon is calculated using exact numerical solution of the evolution equation for the Green function. At x < 0.01 we demonstrate that a contribution of higher Fock states containing gluons to overall nuclear shadowing becomes effective. Numerical results for nuclear shadowing are compared with available data from the E665 and NMC collaborations. Model calculations are finally tested with the results obtained from other models.

  2. The average-shadowing property and topological ergodicity for flows

    Energy Technology Data Exchange (ETDEWEB)

    Gu Rongbao [School of Finance, Nanjing University of Finance and Economics, Nanjing 210046 (China)]. E-mail: rbgu@njue.edu.cn; Guo Wenjing [School of Finance, Nanjing University of Finance and Economics, Nanjing 210046 (China)

    2005-07-01

    In this paper, the transitive property for a flow without sensitive dependence on initial conditions is studied and it is shown that a Lyapunov stable flow with the average-shadowing property on a compact metric space is topologically ergodic.

  3. Shadow Prices of Selected Agricultural Commodities – The Czech Case

    National Research Council Canada - National Science Library

    Patrik Sieber; Karina Pohlová; Ondřej Chaloupka

    2016-01-01

    ... commodities using available statistical data. More specifically, we try to analyse for which commodities secondary data sets are available from which we may deduce the estimates of shadow price ratios, then to estimate SPRs for selected...

  4. Testing General Relativity with the Shadow Size of Sgr A*

    CERN Document Server

    Johannsen, Tim; Plewa, Philipp M; Chatzopoulos, Sotiris; Doeleman, Sheperd S; Eisenhauer, Frank; Fish, Vincent L; Genzel, Reinhard; Gerhard, Ortwin; Johnson, Michael D

    2016-01-01

    In general relativity, the angular radius of the shadow of a black hole is primarily determined by its mass-to-distance ratio and depends only weakly on its spin and inclination. If general relativity is violated, however, the shadow size may also depend strongly on parametric deviations from the Kerr metric. Based on a reconstructed image of Sagittarius A* (Sgr A*) from a simulated one-day observing run of a seven-station Event Horizon Telescope (EHT) array, we employ a Markov chain Monte Carlo algorithm to demonstrate that such an observation can measure the angular radius of the shadow of Sgr A* with an uncertainty of ~1.5 uas (6%). We show that existing mass and distance measurements can be improved significantly when combined with upcoming EHT measurements of the shadow size and that tight constraints on potential deviations from the Kerr metric can be obtained.

  5. Shadowing and nuclear absorption in J/. Psi. hadroproduction

    Energy Technology Data Exchange (ETDEWEB)

    Gay Ducati, M.B. (Instituto de Fisica, Universidade Federal do Rio Grande do Sul, 91500 Porto Alegre (Brazil)); Epele, L.N.; Garcia Canal, C.A. (Laboratorio de Fisica Teorica, Departamento de Fisica, Universidad Nacional de La Plata, 1900 La Plata, (Argentina))

    1989-12-15

    The hadron-nucleus J/{Psi} production is analyxed in a phenomenological picture, considering the parton recombination model. There is an evidence for a nuclear suppression effect, besides shadowing and we obtain good agreement with experimental data.

  6. A NEW METHOD OF MOVING OBJECT DETECTION AND SHADOW REMOVING

    Institute of Scientific and Technical Information of China (English)

    Hu Fuyuan; Zhang Yanning; Yao Lan; Sun Jinqiu

    2007-01-01

    This paper presents an adaptive method of objects and shadows detection in video streams.Models of background are firstly set up and adaptively updated in Hue Saturation Intensity (HSI)color space to detect motion regions. Then, detection errors are dealt with by motion continuity and velocity consistency. Finally, cast shadows are removed by the generic properties of luminance,chrominance and gradient density. Experimental results and their evaluation are presented to verify the effectiveness of this new method.

  7. A historical note on illusory contours in shadow writing.

    Science.gov (United States)

    Vezzani, Stefano; Marino, Barbara F M

    2009-01-01

    It is widely accepted that illusory contours have been first displayed and discussed by Schumann (1900, Zeitschrift für Psychologie und Physiologie der Sinnesorgane 23 1-32). Here we show that, before him, Jastrow (1899, Popular Science Monthly 54 299-312) produced illusory contours consisting of a shadow word. A brief history of shadow writing in psychological literature from Jastrow to Brunswik is presented, in which the contributions of Pillsbury, Warren, Koffka, and Benussi are examined.

  8. Nuclear Shadowing and the Optics of Hadronic Fluctuations

    CERN Document Server

    Piller, G; Mankiewicz, L; Weise, W

    2001-01-01

    A coordinate space description of shadowing in deep-inelastic lepton-nucleus scattering is presented. The picture in the laboratory frame is that of quark-gluon fluctuations of the high-energy virtual photon, propagating coherently over large light-cone distances in the nuclear medium. We discuss the detailed dependence of the coherence effects on the invariant mass of the fluctuation. We comment on the issue of possible saturation in the shadowing effects at very small Bjorken-$x$.

  9. Observation of the Moon Shadow in Deep Underground Muon Flux

    CERN Document Server

    Cobb, J H; Allison, W W M; Alner, G J; Ayres, D S; Barrett, W L; Bode, C; Border, P M; Brooks, C B; Cotton, R J; Courant, H; Demuth, D M; Fields, T H; Gallagher, H R; García-García, C; Goodman, M C; Gran, R; Joffe-Minor, T M; Kafka, T; Kasahara, S M; Leeson, W; Lichtfield, P J; Longley, N P; Mann, W A; Milburn, R H; Miller, W H; Moon, C; Mualem, L M; Napier, A; Oliver, W P; Pearce, G F; Peterson, E A; Petyt, D A; Price, L E; Ruddick, K; Sánchez, M; Sankey, P; Schneps, J; Schub, M H; Seidlein, R; Stassinakis, A; Thron, J L; Vasilev, V; Villaume, G; Wakely, S P; West, N; Wall, D

    1999-01-01

    A shadow of the moon, with a statistical significance of $5\\sigma$, has been observed in the underground muon flux at a depth of 2090 mwe using the Soudan 2 detector. The angular resolution of the detector is well described by a Gaussian with $\\sigma \\le 0.3^{\\circ}$. The position of the shadow confirms the alignment of the detector to better than $0.15^{\\circ}$. This alignment has remained stable during 10 years of data taking from 1989 through 1998.

  10. The Pythagoreans in the light and shadows of recent research

    Directory of Open Access Journals (Sweden)

    Holger Thesleff

    1970-01-01

    Full Text Available It has been said' that "Pythagoras casts a long shadow in the history of Greek thought". Indeed, the shadow both widens and deepens spectacularly in course of time. He has not only been considered—on disputable grounds, as we shall see as the first European mystic. No other personality of the Greco–Roman world (except Christ, and perhaps Alexander the Great has been credited with such powers and all-round capacities.

  11. Observation of the moon shadow in deep underground muon flux.

    Energy Technology Data Exchange (ETDEWEB)

    Allison, W. W. M.; Alner, G. J.; Ayres, D. S.; Cobb, J. H.; Fields, T. H.; Goodman, M. C.; Joffe-Minor, T.; Marshak, M. L.; Price, L. E.; Seidlein, R.; Soudan 2 Collaboration; Thron, J. L.

    1999-06-22

    A shadow of the moon, with a statistical significance of 5{sigma}, has been observed in the underground muon flux at a depth of 2090 mwe using the Soudan 2 detector. The angular resolution of the detector is well described by a Gaussian with {sigma} {le}0.3{degree}. The position of the shadow confirms the alignment of the detector to better than 0.15{degree}. This alignment has remained stable during 10 years of data taking from 1989 through 1998.

  12. Ferromagnetic shadow mask for spray coating of polymer patterns

    DEFF Research Database (Denmark)

    Keller, Stephan Sylvest; Bosco, Filippo; Boisen, Anja

    2013-01-01

    We present the fabrication of a wafer-scale shadow mask with arrays of circular holes with diameters of 150–400 μm. Standard UV photolithography is used to define 700 μm thick SU-8 structures followed by electroplating of nickel and etching of the template. The ferromagnetic properties of the sha...... of the shadow mask allow magnetic clamping to the substrate and spray coating of well defined polymer patterns....

  13. Phoenix Conductivity Probe with Shadow and Toothmark

    Science.gov (United States)

    2008-01-01

    NASA's Phoenix Mars Lander inserted the four needles of its thermal and conductivity probe into Martian soil during the 98th Martian day, or sol, of the mission and left it in place until Sol 99 (Sept. 4, 2008). The Robotic Arm Camera on Phoenix took this image on the morning of Sol 99 after the probe was lifted away from the soil. The imprint left by the insertion is visible below the probe, and a shadow showing the probe's four needles is cast on a rock to the left. The thermal and conductivity probe measures how fast heat and electricity move from one needle to an adjacent one through the soil or air between the needles. Conductivity readings can be indicators about water vapor, water ice and liquid water. The probe is part of Phoenix's Microscopy, Electrochemistry and Conductivity suite of instruments. The Phoenix Mission is led by the University of Arizona, Tucson, on behalf of NASA. Project management of the mission is by NASA's Jet Propulsion Laboratory, Pasadena, Calif. Spacecraft development is by Lockheed Martin Space Systems, Denver.

  14. Smartphone based Tomographic PIV using colored shadows

    Science.gov (United States)

    Aguirre-Pablo, Andres A.; Alarfaj, Meshal K.; Li, Er Qiang; Thoroddsen, Sigurdur T.

    2016-11-01

    We use low-cost smartphones and Tomo-PIV, to reconstruct the 3D-3C velocity field of a vortex ring. The experiment is carried out in an octagonal tank of water with a vortex ring generator consisting of a flexible membrane enclosed by a cylindrical chamber. This chamber is pre-seeded with black polyethylene microparticles. The membrane is driven by an adjustable impulsive air-pressure to produce the vortex ring. Four synchronized smartphone cameras, of 40 Mpx each, are used to capture the location of particles from different viewing angles. We use red, green and blue LED's as backlighting sources, to capture particle locations at different times. The exposure time on the smartphone cameras are set to 2 seconds, while exposing each LED color for about 80 μs with different time steps that can go below 300 μs. The timing of these light pulses is controlled with a digital delay generator. The backlight is blocked by the instantaneous location of the particles in motion, leaving a shadow of the corresponding color for each time step. The image then is preprocessed to separate the 3 different color fields, before using the MART reconstruction and cross-correlation of the time steps to obtain the 3D-3C velocity field. This proof of concept experiment represents a possible low-cost Tomo-PIV setup.

  15. Celestial shadows eclipses, transits, and occultations

    CERN Document Server

    Westfall, John

    2015-01-01

    Much of what is known about the universe comes from the study of celestial shadows—eclipses, transits, and occultations.  The most dramatic are total eclipses of the Sun, which constitute one of the most dramatic and awe-inspiring events of nature.  Though once a source of consternation or dread, solar eclipses now lead thousands of amateur astronomers and eclipse-chasers to travel to remote points on the globe to savor their beauty and the adrenaline-rush of experiencing totality, and were long the only source of information about the hauntingly beautiful chromosphere and corona of the Sun.   Long before Columbus, the curved shadow of the Earth on the Moon during a lunar eclipse revealed that we inhabit a round world. The rare and wonderful transits of Venus, which occur as it passes between the Earth and the Sun, inspired eighteenth century expeditions to measure the distance from the Earth to the Sun, while the recent transits of 2004 and 2012 were the most widely observed ever--and still produced re...

  16. Fast phylogenetic DNA barcoding

    DEFF Research Database (Denmark)

    Terkelsen, Kasper Munch; Boomsma, Wouter Krogh; Willerslev, Eske

    2008-01-01

    We present a heuristic approach to the DNA assignment problem based on phylogenetic inferences using constrained neighbour joining and non-parametric bootstrapping. We show that this method performs as well as the more computationally intensive full Bayesian approach in an analysis of 500 insect...... DNA sequences obtained from GenBank. We also analyse a previously published dataset of environmental DNA sequences from soil from New Zealand and Siberia, and use these data to illustrate the fact that statistical approaches to the DNA assignment problem allow for more appropriate criteria...... for determining the taxonomic level at which a particular DNA sequence can be assigned....

  17. Identification of Methodology of Indirect Assessment of Economy Shadowing

    Directory of Open Access Journals (Sweden)

    Avhustyn Ruslan R.

    2014-03-01

    Full Text Available The article explains the essence of the shadow economy as an objective phenomenon of socio-economic relations and its influence upon national economy security through instruments of pricing, fiscal restrictions, tax control, and banking and insurance regulation. It proves the necessity of use of the indirect method of assessment of the level of economy shadowing along with methods of direct control over the growth of shadowed economic relations, since such an approach would allow rational approach to identification of volumes and level of shadow activity. In the result of the study the article marks out varieties of indirect assessment of economy shadowing (methods of document, accounting and economic analysis, their specific features, advantages and shortcomings and results of practical use. The article reveals approaches and indicators of economic analysis that allow identification of reasons of deviations from the normal economic activity of economic subjects. It provides examples of the indirect method of assessment of the volume of shadowed economy that deal with analysis of demand on money and comparison of rates of the growth of the money supply with the volume of sight drafts with GDP.

  18. The multisensory body revealed through its cast shadows

    Directory of Open Access Journals (Sweden)

    Francesco ePavani

    2015-05-01

    Full Text Available One key issue when conceiving the body as a multisensory object is how the cognitive system integrates visible instances of the self and other bodies with one’s own somatosensory processing, to achieve self-recognition and body ownership. Recent research has strongly suggested that shadows cast by our own body have a special status for cognitive processing, directing attention to the body in a fast and highly specific manner. The aim of the present article is to review the most recent scientific contributions addressing how body shadows affect both sensory/perceptual and attentional processes. The review examines three main points: (1 body shadows as a special window to investigate the construction of multisensory body perception; (2 experimental paradigms and related findings; (3 open questions and future trajectories. The reviewed literature suggests that shadows cast by one’s own body promote binding between personal and extrapersonal space and elicit automatic orienting of attention toward the body-part casting the shadow. Future research should address whether the effects exerted by body shadows are similar to those observed when observers are exposed to other visual instances of their body. The results will further clarify the processes underlying the merging of vision and somatosensation when creating body representations.

  19. Shadows of Kerr Black Holes with Scalar Hair.

    Science.gov (United States)

    Cunha, Pedro V P; Herdeiro, Carlos A R; Radu, Eugen; Rúnarsson, Helgi F

    2015-11-20

    Using backwards ray tracing, we study the shadows of Kerr black holes with scalar hair (KBHSH). KBHSH interpolate continuously between Kerr BHs and boson stars (BSs), so we start by investigating the lensing of light due to BSs. Moving from the weak to the strong gravity region, BSs-which by themselves have no shadows-are classified, according to the lensing produced, as (i) noncompact, which yield not multiple images, (ii) compact, which produce an increasing number of Einstein rings and multiple images of the whole celestial sphere, and (iii) ultracompact, which possess light rings, yielding an infinite number of images with (we conjecture) a self-similar structure. The shadows of KBHSH, for Kerr-like horizons and noncompact BS-like hair, are analogous to, but distinguishable from, those of comparable Kerr BHs. But for non-Kerr-like horizons and ultracompact BS-like hair, the shadows of KBHSH are drastically different: novel shapes arise, sizes are considerably smaller, and multiple shadows of a single BH become possible. Thus, KBHSH provide quantitatively and qualitatively new templates for ongoing (and future) very large baseline interferometry observations of BH shadows, such as those of the Event Horizon Telescope.

  20. MACROECONOMIC DETERMINANTS OF SHADOW BANKING – EVIDENCE FROM EU COUNTRIES

    Directory of Open Access Journals (Sweden)

    TEODORA CRISTINA BARBU

    2016-12-01

    Full Text Available Shadow banking is a topical, debated issue on the agenda of national and European macro-prudential regulatory and supervisory authorities. It is generally accepted that shadow banks and the traditional banking system have some core functions in common, such as credit and maturity transformation, and the exposure to similar risks. However, the tight banking regulations and the decreasing trend recorded by interest rates in the post-crisis period create prospects for shadow banking sector growth. Against this background, the present paper aims at investigating the particular impact that shadow banking activity exerts on macroeconomic fundamentals. The analysis covers 15 European Union countries, including Romania, during the period 2008 – 2015, using quarterly data. Shadow banking system is used as a proxy by monetary funds, due to breaks in the series or unbalanced number of observations across selected countries. By employing panel regression, it was found that the shadow banking total assets’ variation is negatively influenced by the GDP growth, short term interest rates, M2/GDP ratio and the ratio of investment funds’ assets in GDP, and positively determined by stock index dynamics and long term interest rates. The findings sustain the literature’s point of view.

  1. Shadow Segmentation and Augmentation Using á-overlay Models that Account for Penumbra

    DEFF Research Database (Denmark)

    Nielsen, Michael; Madsen, Claus B.

    2006-01-01

    that an augmented virtual object can cast an exact shadow. The penumbras (half-shadows) must be taken into account so that we can model the soft shadows.We hope to achieve this by modelling the shadow regions (umbra and penumbra alike) with a transparent overlay. This paper reviews the state-of-the-art shadow...... theories and presents two overlay models. These are analyzed analytically in relation to color theory and tangibility....

  2. Phylogenetic trees in bioinformatics

    Energy Technology Data Exchange (ETDEWEB)

    Burr, Tom L [Los Alamos National Laboratory

    2008-01-01

    Genetic data is often used to infer evolutionary relationships among a collection of viruses, bacteria, animal or plant species, or other operational taxonomic units (OTU). A phylogenetic tree depicts such relationships and provides a visual representation of the estimated branching order of the OTUs. Tree estimation is unique for several reasons, including: the types of data used to represent each OTU; the use ofprobabilistic nucleotide substitution models; the inference goals involving both tree topology and branch length, and the huge number of possible trees for a given sample of a very modest number of OTUs, which implies that fmding the best tree(s) to describe the genetic data for each OTU is computationally demanding. Bioinformatics is too large a field to review here. We focus on that aspect of bioinformatics that includes study of similarities in genetic data from multiple OTUs. Although research questions are diverse, a common underlying challenge is to estimate the evolutionary history of the OTUs. Therefore, this paper reviews the role of phylogenetic tree estimation in bioinformatics, available methods and software, and identifies areas for additional research and development.

  3. Entanglement, Invariants, and Phylogenetics

    Science.gov (United States)

    Sumner, J. G.

    2007-10-01

    This thesis develops and expands upon known techniques of mathematical physics relevant to the analysis of the popular Markov model of phylogenetic trees required in biology to reconstruct the evolutionary relationships of taxonomic units from biomolecular sequence data. The techniques of mathematical physics are plethora and have been developed for some time. The Markov model of phylogenetics and its analysis is a relatively new technique where most progress to date has been achieved by using discrete mathematics. This thesis takes a group theoretical approach to the problem by beginning with a remarkable mathematical parallel to the process of scattering in particle physics. This is shown to equate to branching events in the evolutionary history of molecular units. The major technical result of this thesis is the derivation of existence proofs and computational techniques for calculating polynomial group invariant functions on a multi-linear space where the group action is that relevant to a Markovian time evolution. The practical results of this thesis are an extended analysis of the use of invariant functions in distance based methods and the presentation of a new reconstruction technique for quartet trees which is consistent with the most general Markov model of sequence evolution.

  4. The Phylogenetic Diversity of Metagenomes

    Science.gov (United States)

    Kembel, Steven W.; Eisen, Jonathan A.; Pollard, Katherine S.; Green, Jessica L.

    2011-01-01

    Phylogenetic diversity—patterns of phylogenetic relatedness among organisms in ecological communities—provides important insights into the mechanisms underlying community assembly. Studies that measure phylogenetic diversity in microbial communities have primarily been limited to a single marker gene approach, using the small subunit of the rRNA gene (SSU-rRNA) to quantify phylogenetic relationships among microbial taxa. In this study, we present an approach for inferring phylogenetic relationships among microorganisms based on the random metagenomic sequencing of DNA fragments. To overcome challenges caused by the fragmentary nature of metagenomic data, we leveraged fully sequenced bacterial genomes as a scaffold to enable inference of phylogenetic relationships among metagenomic sequences from multiple phylogenetic marker gene families. The resulting metagenomic phylogeny can be used to quantify the phylogenetic diversity of microbial communities based on metagenomic data sets. We applied this method to understand patterns of microbial phylogenetic diversity and community assembly along an oceanic depth gradient, and compared our findings to previous studies of this gradient using SSU-rRNA gene and metagenomic analyses. Bacterial phylogenetic diversity was highest at intermediate depths beneath the ocean surface, whereas taxonomic diversity (diversity measured by binning sequences into taxonomically similar groups) showed no relationship with depth. Phylogenetic diversity estimates based on the SSU-rRNA gene and the multi-gene metagenomic phylogeny were broadly concordant, suggesting that our approach will be applicable to other metagenomic data sets for which corresponding SSU-rRNA gene sequences are unavailable. Our approach opens up the possibility of using metagenomic data to study microbial diversity in a phylogenetic context. PMID:21912589

  5. Doctoring Undercover: updating the educational tradition of shadowing

    Science.gov (United States)

    Clark, Claire D.

    2017-01-01

    ABSTRACT Background: Premedical students are educated in basic biological and health sciences. As a complement to traditional premedical coursework, medical school applicants are encouraged to shadow practitioners, with the hope that observation will introduce students to the culture and practice of healthcare. Yet the shadowing experience varies widely across practitioners and institutions; resources that guide students’ critical reflection and structure the experience are scarce. Development: A pilot experiential learning course, Doctoring Undercover: Shadowing and the Culture of Medicine, was developed to fill this gap. The course consisted of three parts: an introduction to medical culture through the disciplines of medical sociology, history, anthropology, and bioethics; a site placement in which students applied these fields’ analytical techniques to the study of medical culture and practice; and the development of an online activity guide that other premedical students may adapt to their shadowing circumstances. Implementation: Students reported that they were exposed to new disciplinary perspectives and interprofessional environments that they would not traditionally encounter. Students’ contributions to the shadowing guide encouraged active learning and reflection on the dynamics of effective patient-provider relationships and shadowing experiences. Future Directions: Locally, the class may be scaled for a larger group of premedical students and incorporated into a formal pathway program for premedical students; the content will also be integrated into the clinical medicine course for first-year medical students. Online, the guide will be promoted for use by other institutions and by individuals planning extracurricular shadowing experiences; feedback will be solicited. Tools for evaluating the short- and long-term impact of the course and guide will be developed and validated. Observational and experimental studies of the course’s impact should be

  6. Incompletely resolved phylogenetic trees inflate estimates of phylogenetic conservatism.

    Science.gov (United States)

    Davies, T Jonathan; Kraft, Nathan J B; Salamin, Nicolas; Wolkovich, Elizabeth M

    2012-02-01

    The tendency for more closely related species to share similar traits and ecological strategies can be explained by their longer shared evolutionary histories and represents phylogenetic conservatism. How strongly species traits co-vary with phylogeny can significantly impact how we analyze cross-species data and can influence our interpretation of assembly rules in the rapidly expanding field of community phylogenetics. Phylogenetic conservatism is typically quantified by analyzing the distribution of species values on the phylogenetic tree that connects them. Many phylogenetic approaches, however, assume a completely sampled phylogeny: while we have good estimates of deeper phylogenetic relationships for many species-rich groups, such as birds and flowering plants, we often lack information on more recent interspecific relationships (i.e., within a genus). A common solution has been to represent these relationships as polytomies on trees using taxonomy as a guide. Here we show that such trees can dramatically inflate estimates of phylogenetic conservatism quantified using S. P. Blomberg et al.'s K statistic. Using simulations, we show that even randomly generated traits can appear to be phylogenetically conserved on poorly resolved trees. We provide a simple rarefaction-based solution that can reliably retrieve unbiased estimates of K, and we illustrate our method using data on first flowering times from Thoreau's woods (Concord, Massachusetts, USA).

  7. On Nakhleh's metric for reduced phylogenetic networks.

    Science.gov (United States)

    Cardona, Gabriel; Llabrés, Mercè; Rosselló, Francesc; Valiente, Gabriel

    2009-01-01

    We prove that Nakhleh's metric for reduced phylogenetic networks is also a metric on the classes of tree-child phylogenetic networks, semibinary tree-sibling time consistent phylogenetic networks, and multilabeled phylogenetic trees. We also prove that it separates distinguishable phylogenetic networks. In this way, it becomes the strongest dissimilarity measure for phylogenetic networks available so far. Furthermore, we propose a generalization of that metric that separates arbitrary phylogenetic networks.

  8. A separable shadow Hamiltonian hybrid Monte Carlo method.

    Science.gov (United States)

    Sweet, Christopher R; Hampton, Scott S; Skeel, Robert D; Izaguirre, Jesús A

    2009-11-07

    Hybrid Monte Carlo (HMC) is a rigorous sampling method that uses molecular dynamics (MD) as a global Monte Carlo move. The acceptance rate of HMC decays exponentially with system size. The shadow hybrid Monte Carlo (SHMC) was previously introduced to reduce this performance degradation by sampling instead from the shadow Hamiltonian defined for MD when using a symplectic integrator. SHMC's performance is limited by the need to generate momenta for the MD step from a nonseparable shadow Hamiltonian. We introduce the separable shadow Hamiltonian hybrid Monte Carlo (S2HMC) method based on a formulation of the leapfrog/Verlet integrator that corresponds to a separable shadow Hamiltonian, which allows efficient generation of momenta. S2HMC gives the acceptance rate of a fourth order integrator at the cost of a second-order integrator. Through numerical experiments we show that S2HMC consistently gives a speedup greater than two over HMC for systems with more than 4000 atoms for the same variance. By comparison, SHMC gave a maximum speedup of only 1.6 over HMC. S2HMC has the additional advantage of not requiring any user parameters beyond those of HMC. S2HMC is available in the program PROTOMOL 2.1. A Python version, adequate for didactic purposes, is also in MDL (http://mdlab.sourceforge.net/s2hmc).

  9. The interrupted power law and the size of shadow banking.

    Science.gov (United States)

    Fiaschi, Davide; Kondor, Imre; Marsili, Matteo; Volpati, Valerio

    2014-01-01

    Using public data (Forbes Global 2000) we show that the asset sizes for the largest global firms follow a Pareto distribution in an intermediate range, that is "interrupted" by a sharp cut-off in its upper tail, where it is totally dominated by financial firms. This flattening of the distribution contrasts with a large body of empirical literature which finds a Pareto distribution for firm sizes both across countries and over time. Pareto distributions are generally traced back to a mechanism of proportional random growth, based on a regime of constant returns to scale. This makes our findings of an "interrupted" Pareto distribution all the more puzzling, because we provide evidence that financial firms in our sample should operate in such a regime. We claim that the missing mass from the upper tail of the asset size distribution is a consequence of shadow banking activity and that it provides an (upper) estimate of the size of the shadow banking system. This estimate-which we propose as a shadow banking index-compares well with estimates of the Financial Stability Board until 2009, but it shows a sharper rise in shadow banking activity after 2010. Finally, we propose a proportional random growth model that reproduces the observed distribution, thereby providing a quantitative estimate of the intensity of shadow banking activity.

  10. Shadows of Kerr black holes with scalar hair

    CERN Document Server

    Cunha, Pedro V P; Radu, Eugen; Runarsson, Helgi F

    2015-01-01

    Using backwards ray tracing, we study the shadows of Kerr black holes with scalar hair (KBHsSH). KBHsSH interpolate continuously between Kerr BHs and boson stars (BSs), so we start by investigating the lensing of light due to BSs. Moving from the weak to the strong gravity region, BSs - which by themselves have no shadows - are classified, according to the lensing produced, as: $(i)$ non-compact, which yield no multiple images; $(ii)$ compact, which produce an increasing number of Einstein rings and multiple images of the whole celestial sphere; $(iii)$ ultra-compact, which possess light rings, yielding an infinite number of images with (we conjecture) a self-similar structure. The shadows of KBHsSH, for Kerr-like horizons and non-compact BS-like hair, are analogous to, but distinguishable from, those of comparable Kerr BHs. But for non-Kerr-like horizons and ultra-compact BS-like hair, the shadows of KBHsSH are drastically different: novel shapes arise, sizes are considerably smaller and multiple shadows of ...

  11. Binary black hole shadows, chaotic scattering and the Cantor set

    CERN Document Server

    Shipley, Jake

    2016-01-01

    We investigate the qualitative features of binary black hole shadows using the model of two extremally charged black holes in static equilibrium (a Majumdar--Papapetrou solution). Our perspective is that binary spacetimes are natural exemplars of {\\it chaotic scattering}, because they admit more than one fundamental null orbit, and thus an uncountably-infinite set of perpetual orbits which generate scattering singularities in initial data. Inspired by the three-disc model, we develop an appropriate symbolic dynamics to describe planar null geodesics on the double black hole spacetime. We show that a one-dimensional (1D) black hole shadow may constructed through an iterative procedure akin to the construction of the Cantor set; thus the shadow is self-similar. Next, we study non-planar rays, to understand how angular momentum affects the existence and properties of the fundamental null orbits. Taking slices through 2D shadows, we observe three types of 1D shadow: regular, Cantor-like, and highly chaotic. The s...

  12. A Multi-Resolution Mode CMOS Image Sensor with a Novel Two-Step Single-Slope ADC for Intelligent Surveillance Systems

    Directory of Open Access Journals (Sweden)

    Daehyeok Kim

    2017-06-01

    Full Text Available In this paper, we present a multi-resolution mode CMOS image sensor (CIS for intelligent surveillance system (ISS applications. A low column fixed-pattern noise (CFPN comparator is proposed in 8-bit two-step single-slope analog-to-digital converter (TSSS ADC for the CIS that supports normal, 1/2, 1/4, 1/8, 1/16, 1/32, and 1/64 mode of pixel resolution. We show that the scaled-resolution images enable CIS to reduce total power consumption while images hold steady without events. A prototype sensor of 176 × 144 pixels has been fabricated with a 0.18 μm 1-poly 4-metal CMOS process. The area of 4-shared 4T-active pixel sensor (APS is 4.4 μm × 4.4 μm and the total chip size is 2.35 mm × 2.35 mm. The maximum power consumption is 10 mW (with full resolution with supply voltages of 3.3 V (analog and 1.8 V (digital and 14 frame/s of frame rates.

  13. 目标检测的多分辨小波Holder数法%Target Detection by Using Multi-Resolution Fractal Holder Constant

    Institute of Scientific and Technical Information of China (English)

    刘文予; 李华; 朱光喜

    2000-01-01

    针对传统纹理分割方法的不足,从分形布朗运动的平均Holder数出发,提取人造目标与自然场景的相对距离,根据相对距离区分物体和背景,通过不同分辨率下的小波Holder数的计算,进行直线拟合.利用拟合后直线的斜率及线性度等参数可进行目标的检测.实验表明,与用单纯的分形特征参数相比,所提出的方法是一种快速、有效的人造目标识别方法.%A novel method of target recognition based on multi-resolution analysis and Holder constant is proposed. With the description of the average Holder constant of fractional Brownian motion and analyzing the different distance of 3D surface between the target and complex background, the wavelet Holder constants are calculated in a serial of images. The target is recognized by the detection of the linearity error and some parameters. The experiments show that this methodis suitable for identifying specific targets and is good in noise immunity.

  14. Megaflood analysis through channel networks of the Athabasca Valles, Mars based on multi-resolution stereo DTMs and 2D hydrodynamic modeling

    Science.gov (United States)

    Kim, Jung-Rack; Schumann, Guy; Neal, Jeffrey C.; Lin, Shih-Yuan

    2014-09-01

    Stereo analysis of in-orbital imagery provides valuable topographic data for scientific research over planetary surfaces especially for the interpretation of potential fluvial activity. The focus of research into planetary fluvial activity has been shifting toward quantitative modeling with various spatial resolution DTMs from visual interpretation with ortho images. Thus in this study, we tested the application of hydraulic analysis with multi resolution Martian DTMs, which were constructed following the approaches of Kim and Muller (2009). Planet. Space Sci. 57 (14), 2095. Subsequently, a two-dimensional hydraulic model was introduced to conduct flow simulation using the extracted 1.2-150 m resolution DTMs. As a result, it was found that the simulated water flows coincided with what might be water eroded geomorphic features over target areas. Moreover, the information acquired from the modeling, such as water depth along the time line, flow direction and travel time, is proving of great value for the interpretation of surface characteristics. Results highlighted the importance of DTM quality for simulating fluvial channel hydraulics across planetary surfaces.

  15. REAL-TIME SHADOW USING A COMBINATION OF STENCIL AND THE Z-BUFFER

    Directory of Open Access Journals (Sweden)

    Hoshang Kolivand

    2011-08-01

    Full Text Available In this paper we describe a real-time shadow generation with volume shadow algorithm in virtual environment that is illuminated by light sources with possibility to move separately. This algorithm uses the combination of stencil and Z-buffers to generate shadow volume. It is simple to understand and implement. We have significantly improved and implemented recent techniques that are used in shadow volume algorithms using stencil buffers especially in order to recognize silhouette, reduce the number of shadow polygons and also redundant length of each triangles that makes the volume shadow. This work may be applied in commercial games or other virtual reality systems.

  16. Ultrafast Approximation for Phylogenetic Bootstrap

    NARCIS (Netherlands)

    Bui Quang Minh, [No Value; Nguyen, Thi; von Haeseler, Arndt

    2013-01-01

    Nonparametric bootstrap has been a widely used tool in phylogenetic analysis to assess the clade support of phylogenetic trees. However, with the rapidly growing amount of data, this task remains a computational bottleneck. Recently, approximation methods such as the RAxML rapid bootstrap (RBS) and

  17. Quartets and unrooted phylogenetic networks.

    Science.gov (United States)

    Gambette, Philippe; Berry, Vincent; Paul, Christophe

    2012-08-01

    Phylogenetic networks were introduced to describe evolution in the presence of exchanges of genetic material between coexisting species or individuals. Split networks in particular were introduced as a special kind of abstract network to visualize conflicts between phylogenetic trees which may correspond to such exchanges. More recently, methods were designed to reconstruct explicit phylogenetic networks (whose vertices can be interpreted as biological events) from triplet data. In this article, we link abstract and explicit networks through their combinatorial properties, by introducing the unrooted analog of level-k networks. In particular, we give an equivalence theorem between circular split systems and unrooted level-1 networks. We also show how to adapt to quartets some existing results on triplets, in order to reconstruct unrooted level-k phylogenetic networks. These results give an interesting perspective on the combinatorics of phylogenetic networks and also raise algorithmic and combinatorial questions.

  18. Shadow education: Effects on students’ self-efficacy in science

    Directory of Open Access Journals (Sweden)

    Darryl Roy Tabasa Montebon

    2016-01-01

    Full Text Available This study aims to investigate the effect of shadow education on students’ self-efficacy. Shadow education or tutoring mimics the mainstream form of education (Bray, 1999 while self-efficacy is a personal judgment of one’s capability to plan and execute a course of action to achieve a certain goal (Bandura, 1977 as cited by Zimmerman, 2000. Results of this study described the tutorial background of the respondents and their self-efficacy levels. It has been found out that students’ self-efficacy due to exposure to shadow education is high. The self-efficacy of students does not necessarily vary when compared by gender, grade level, and the length of time that respondents have been going to tutorial sessions.

  19. Self-shadowing in ballistic fan formation from point seeds

    Science.gov (United States)

    Pelliccione, M.; Lu, T.-M.

    2007-06-01

    We utilize the model of ballistic aggregation to investigate the growth of particles on a point seed under various oblique particle fluxes to model nanorod growth at early deposition times. In particular, we show that the angular nature of the particle flux leads to a self-shadowing behavior, where features of an individual aggregate can shadow other features of the same aggregate. We quantify the shape of the aggregates by the growth exponent p , where the radius of the aggregate R is related to the height of the aggregate z as Rtilde zp . We show that the self-shadowing effect is the dominant factor that controls the evolution of nanorod size during oblique angle deposition. The simulation predictions are consistent with recent experimental results.

  20. Black hole shadows in fourth-order conformal Weyl gravity

    CERN Document Server

    Mureika, Jonas R

    2016-01-01

    We calculate the characteristics of the "black hole shadow" for a rotating, neutral black hole in fourth-order conformal Weyl gravity. It is shown that the morphology is not significantly affected by the underlying framework, except for very large masses. Conformal gravity black hole shadows would also significantly differ from their general relativistic counterparts if the values of the main conformal gravity parameters, $\\gamma$ and $\\kappa$, were increased by several orders of magnitude. Such increased values for $\\gamma$ and $\\kappa$ are currently ruled out by gravitational phenomenology. Therefore, it is unlikely that these differences in black hole shadows will be detected in future observations, carried out by the Event Horizon Telescope or others such experiments.

  1. Shadow mask assisted heteroepitaxy of compound semiconductor nanostructures

    Energy Technology Data Exchange (ETDEWEB)

    Schallenberg, T.

    2004-07-01

    Shadow Mask assisted Molecular Beam Epitaxy (SMMBE) is a technique enabling selected area epitaxy of semiconductor heterostructures through shadow masks. The objective of this work was the development of the SMMBE technique for the reliable fabrication of compound semiconductor nanostructures of high structural and optical quality. In order to accomplish this, technological processes have been developed and optimized. One of the technological developments to this effect, which has substantially enhanced the versatility of SMMBE, is the introduction of a new type of freestanding shadow masks. A consistent model has been developed, which successfully explains the growth dynamics of molecular beam epitaxy through shadow masks. The predictions of the model regarding the growth of II-VI and III-V compounds have been tested experimentally and the dependence of the growth rates on the growth parameters has been verified. Moreover, it has been shown, that selected area epitaxy of II-VI and III-V compounds are governed by different surface kinetics. In addition to the basic surface kinetic processes described by the model, the roles of orientation and strain-dependent growth dynamics, partial shadow, and material deposition on the mask (closure of apertures) have been discussed. The resulting advanced understanding of the growth dynamics (model and basic experiments) in combination with the implementation of technical improvements has enabled the development and application of a number of different processes for the fabrication of both II-VI and III-V nanostructures. In addition to specific material properties, various other phenomena have been exploited, e.g., self-organization. Bright cathodoluminescence demonstrates that the resulting quantum structures are of high structural and optical quality. In addition to these results the limitations of the method have also been discussed, and various approaches to overcome them have been suggested. Moreover, propositions for the

  2. Binary black hole shadows, chaotic scattering and the Cantor set

    Science.gov (United States)

    Shipley, Jake O.; Dolan, Sam R.

    2016-09-01

    We investigate the qualitative features of binary black hole shadows using the model of two extremally charged black holes in static equilibrium (a Majumdar-Papapetrou solution). Our perspective is that binary spacetimes are natural exemplars of chaotic scattering, because they admit more than one fundamental null orbit, and thus an uncountably infinite set of perpetual null orbits which generate scattering singularities in initial data. Inspired by the three-disc model, we develop an appropriate symbolic dynamics to describe planar null geodesics on the double black hole spacetime. We show that a one-dimensional (1D) black hole shadow may be constructed through an iterative procedure akin to the construction of the Cantor set; thus the 1D shadow is self-similar. Next, we study non-planar rays, to understand how angular momentum affects the existence and properties of the fundamental null orbits. Taking slices through 2D shadows, we observe three types of 1D shadow: regular, Cantor-like, and highly chaotic. The switch from Cantor-like to regular occurs where outer fundamental orbits are forbidden by angular momentum. The highly chaotic part is associated with an unexpected feature: stable and bounded null orbits, which exist around two black holes of equal mass M separated by {a}1\\lt a\\lt \\sqrt{2}{a}1, where {a}1=4M/\\sqrt{27}. To show how this possibility arises, we define a certain potential function and classify its stationary points. We conjecture that the highly chaotic parts of the 2D shadow possess the Wada property. Finally, we consider the possibility of following null geodesics through event horizons, and chaos in the maximally extended spacetime.

  3. Phylogenetic molecular function annotation

    Science.gov (United States)

    Engelhardt, Barbara E.; Jordan, Michael I.; Repo, Susanna T.; Brenner, Steven E.

    2009-07-01

    It is now easier to discover thousands of protein sequences in a new microbial genome than it is to biochemically characterize the specific activity of a single protein of unknown function. The molecular functions of protein sequences have typically been predicted using homology-based computational methods, which rely on the principle that homologous proteins share a similar function. However, some protein families include groups of proteins with different molecular functions. A phylogenetic approach for predicting molecular function (sometimes called "phylogenomics") is an effective means to predict protein molecular function. These methods incorporate functional evidence from all members of a family that have functional characterizations using the evolutionary history of the protein family to make robust predictions for the uncharacterized proteins. However, they are often difficult to apply on a genome-wide scale because of the time-consuming step of reconstructing the phylogenies of each protein to be annotated. Our automated approach for function annotation using phylogeny, the SIFTER (Statistical Inference of Function Through Evolutionary Relationships) methodology, uses a statistical graphical model to compute the probabilities of molecular functions for unannotated proteins. Our benchmark tests showed that SIFTER provides accurate functional predictions on various protein families, outperforming other available methods.

  4. Near-wall velocity measurements by Particle-Shadow-Tracking

    CERN Document Server

    Lancien, Pierre; Métivier, François; 10.1007/s00348-007-0260-z

    2009-01-01

    We report a new method to measure the velocity of a fluid in the vicinity of a wall. The method, that we call Particle-Shadow Tracking (PST), simply consists in seeding the fluid with a small number of fine tracer particles of density close to that of the fluid. The position of each particle and of its shadow on the wall are then tracked simultaneously, allowing one to accurately determine the distance separating tracers from the wall and therefore to extract the velocity field. We present an application of the method to the determination of the velocity profile inside a laminar density current flowing along an inclined plane.

  5. Medium Access Control for Opportunistic Concurrent Transmissions under Shadowing Channels

    Directory of Open Access Journals (Sweden)

    Seung Min Hur

    2009-06-01

    Full Text Available We study the problem of how to alleviate the exposed terminal effect in multihop wireless networks in the presence of log-normal shadowing channels. Assuming node location information, we propose an extension of the IEEE 802.11 MAC protocol that schedules concurrent transmissions in the presence of log-normal shadowing, thus mitigating the exposed terminal problem and improving network throughput and delay performance. We observe considerable improvements in throughput and delay achieved over the IEEE 802.11 MAC under various network topologies and channel conditions in ns-2 simulations, which justify the importance of considering channel randomness in MAC protocol design for multihop wireless networks.

  6. Estimating Outdoor Illumination Conditions Based on Detection of Dynamic Shadows

    DEFF Research Database (Denmark)

    Madsen, Claus B.; Lal, Brajesh Behari

    2013-01-01

    The paper proposes a technique for estimation outdoor illumination conditions in terms of sun and sky radiances directly from pixel values of dynamic shadows detected in video sequences produved by a commercial stereo camera. The technique is applied to the rendering of virtual object into the im......The paper proposes a technique for estimation outdoor illumination conditions in terms of sun and sky radiances directly from pixel values of dynamic shadows detected in video sequences produved by a commercial stereo camera. The technique is applied to the rendering of virtual object...

  7. Defining solar park location using shadow over time detection method

    Science.gov (United States)

    Martynov, Ivan; Kauranne, Tuomo

    2016-06-01

    There is nowadays a high demand for research on using renewable sources of energy including solar energy. The availability of stable and efficient solar energy is of paramount importance. Therefore, it is vital to install solar panels in locations which are most of the time not in shadow. To illustrate this idea we have developed a shadow identification method for digital elevation models (DEMs) using the computational means of MATLAB whose environment and tools allow fast and easy image processing. As a source of DEMs we use the Shuttle Radar Topography Mission (SRTM) database since it covers most of the terrain of our planet.

  8. Phylogenetics and the human microbiome.

    Science.gov (United States)

    Matsen, Frederick A

    2015-01-01

    The human microbiome is the ensemble of genes in the microbes that live inside and on the surface of humans. Because microbial sequencing information is now much easier to come by than phenotypic information, there has been an explosion of sequencing and genetic analysis of microbiome samples. Much of the analytical work for these sequences involves phylogenetics, at least indirectly, but methodology has developed in a somewhat different direction than for other applications of phylogenetics. In this article, I review the field and its methods from the perspective of a phylogeneticist, as well as describing current challenges for phylogenetics coming from this type of work.

  9. The shadow system in coordinate space: The shadow system in coordinate space: A locally explicable system that violates Bell's inequality

    CERN Document Server

    Leffler, Warren

    2009-01-01

    We explore the consequences of denying the "emptiness of paths not taken," EPNT, a premise of Bernstein, Greenberger, Horne, and Zeilinger in their paper titled, Bell theorem without inequalities. Carrying out the negation of EPNT leads to the concept of a "shadow stream." Streams are essentially particle implementations of the path amplitudes in Feynman's formulation of quantum mechanics, resulting in a simple and consistent extension of the standard postulates for quantum mechanics. Following up on the negation of EPNT using shadow streams, we analyze the experimental outcomes in a standard two-particle interferometer. The result is a simple counterexample to Bell's theorem in position/momentum space.

  10. [Foundations of the new phylogenetics].

    Science.gov (United States)

    Pavlinov, I Ia

    2004-01-01

    Evolutionary idea is the core of the modern biology. Due to this, phylogenetics dealing with historical reconstructions in biology takes a priority position among biological disciplines. The second half of the 20th century witnessed growth of a great interest to phylogenetic reconstructions at macrotaxonomic level which replaced microevolutionary studies dominating during the 30s-60s. This meant shift from population thinking to phylogenetic one but it was not revival of the classical phylogenetics; rather, a new approach emerged that was baptized The New Phylogenetics. It arose as a result of merging of three disciplines which were developing independently during 60s-70s, namely cladistics, numerical phyletics, and molecular phylogenetics (now basically genophyletics). Thus, the new phylogenetics could be defined as a branch of evolutionary biology aimed at elaboration of "parsimonious" cladistic hypotheses by means of numerical methods on the basis of mostly molecular data. Classical phylogenetics, as a historical predecessor of the new one, emerged on the basis of the naturphilosophical worldview which included a superorganismal idea of biota. Accordingly to that view, historical development (the phylogeny) was thought an analogy of individual one (the ontogeny) so its most basical features were progressive parallel developments of "parts" (taxa), supplemented with Darwinian concept of monophyly. Two predominating traditions were diverged within classical phylogenetics according to a particular interpretation of relation between these concepts. One of them (Cope, Severtzow) belittled monophyly and paid most attention to progressive parallel developments of morphological traits. Such an attitude turned this kind of phylogenetics to be rather the semogenetics dealing primarily with evolution of structures and not of taxa. Another tradition (Haeckel) considered both monophyletic and parallel origins of taxa jointly: in the middle of 20th century it was split into

  11. Dynamics of a Coupled System: Multi-Resolution Remote Sensing in Assessing Social-Ecological Responses during 25 Years of Gas Field Development in Arctic Russia

    Directory of Open Access Journals (Sweden)

    Florian Stammler

    2012-04-01

    Full Text Available Hydrocarbon exploration has been underway in the north of West Siberia for several decades. Giant gas fields on the Yamal Peninsula are expected to begin feeding the Nord Stream pipeline to Western Europe in late 2012. Employing a variety of high- to very high-resolution satellite-based sensors, we have followed the establishment and spread of Bovanenkovo, the biggest and first field to be developed. Extensive onsite field observations and measurements of land use and land cover changes since 1985 have been combined with intensive participant observation in all seasons among indigenous Nenets reindeer herders and long-term gas field workers during 2004–2007 and 2010–2011. Time series and multi-resolution imagery was used to build a chronology of the gas field’s development. Large areas of partially or totally denuded tundra and most forms of expanding infrastructure are readily tracked with Landsat scenes (1985, 1988, 2000, 2009, 2011. SPOT (1993, 1998 and ASTER (2001 were also used. Quickbird-2 (2004 and GeoEye (2010 were most successful in detecting small-scale anthropogenic disturbances as well as individual camps of nomadic herders moving in the vicinity of the gas field. For assessing gas field development the best results are obtained by combining lower resolution with Very High Resolution (VHR imagery (spatial resolution < 5 m and fieldwork. Nenets managing collective and privately owned herds of reindeer have proven adept in responding to a broad range of intensifying industrial impacts at the same time as they have been dealing with symptoms of a warming climate. Here we detail both the spatial extent of gas field growth and the dynamic relationship between Nenets nomads and their rapidly evolving social-ecological system.

  12. Bow and stern waves triggered by the Moon's shadow boat

    National Research Council Canada - National Science Library

    J. Y. Liu; Y. Y. Sun; Y. Kakinami; C. H. Chen; C. H. Lin; H. F. Tsai

    2011-01-01

    ...) derived from ground-based GPS receivers in Taiwan and Japan. We not only find the feature of the predicted bow wave but also the stern wave on the equator side of the eclipse path, as well as the stern wake right behind the Moon's shadow boat...

  13. Shadow Formation at Preschool from a Socio-materiality Perspective

    Science.gov (United States)

    Impedovo, Maria Antonietta; Delserieys-Pedregosa, Alice; Jégou, Corinne; Ravanis, Konstantinos

    2017-06-01

    The paper is set in socio-material farming to offer a way of conceptualising actions and interactions of children in preschool involved in the understanding of scientific concepts. A model of early science education about the physical phenomena of shadow formation is implemented in group work in a French context. The research involved 44 children (13 females and 31 males) of 5-6 years old. The research design was organised in three video recording steps: pre-test, teaching session and post-test. We focus on the analysis of nine teaching sessions to investigate children's `understanding' of shadow formation. A descriptive and qualitative approach was used. In particular, we have identified three main categories (the interaction of the children with the tools, the embodiment and verbal dimension)—with respective indicators—to perform the analysis. From the results, all the categories explored seem to influence each other: all material, human and social dimensions contribute to the children's understanding of shadow formation. Also we have identified some elements that can serve as a potential source of improvement of the teaching session on shadow formation. Finally, the research provides insights on how to improve science activities in preschool with the aim of supporting early understanding of physical phenomena.

  14. Perspective: Dynamic Shadowing Growth and its Energy Applications

    Directory of Open Access Journals (Sweden)

    Yiping eZhao

    2014-09-01

    Full Text Available The unique features of dynamic shadowing growth (DSG in structural and compositional design of nanomaterials are discussed. Their recent applications in energy storage, fuel cell, and solar energy conversion have been reviewed briefly. Future directions for applying DSG nanostructures in renewable energy applications are presented.

  15. Dark Matter Trapping by Stellar Bars: The Shadow Bar

    Science.gov (United States)

    Petersen, Michael S.; Weinberg, Martin D.; Katz, Neal

    2016-09-01

    We investigate the complex interactions between the stellar disc and the dark-matter halo during bar formation and evolution using N-body simulations with fine temporal resolution and optimally chosen spatial resolution. We find that the forming stellar bar traps dark matter in the vicinity of the stellar bar into bar-supporting orbits. We call this feature the shadow bar. The shadow bar modifies both the location and magnitude of the angular momentum transfer between the disc and dark matter halo and adds 10 per cent to the mass of the stellar bar over 4 Gyr. The shadow bar is potentially observable by its density and velocity signature in spheroid stars and by direct dark matter detection experiments. Numerical tests demonstrate that the shadow bar can diminish the rate of angular momentum transport from the bar to the dark matter halo by more than a factor of three over the rate predicted by dynamical friction with an untrapped dark halo, and thus provides a possible physical explanation for the observed prevalence of fast bars in nature.

  16. Dark Matter Trapping by Stellar Bars: The Shadow Bar

    CERN Document Server

    Petersen, Michael S; Katz, Neal

    2016-01-01

    We investigate the complex interactions between the stellar disc and the dark-matter halo during bar formation and evolution using N-body simulations with fine temporal resolution and optimally chosen spatial resolution. We find that the forming stellar bar traps dark matter in the vicinity of the stellar bar into bar-supporting orbits. We call this feature the shadow bar. The shadow bar modifies both the location and magnitude of the angular momentum transfer between the disc and dark matter halo and adds 10 per cent to the mass of the stellar bar over 4 Gyr. The shadow bar is potentially observable by its density and velocity signature in spheroid stars and by direct dark matter detection experiments. Numerical tests demonstrate that the shadow bar can diminish the rate of angular momentum transport from the bar to the dark matter halo by more than a factor of three over the naive dynamical friction prediction, and thus provides a possible physical explanation for the observed prevalence of fast bars in nat...

  17. On Risk Charges and Shadow Account Options in Pension Funds

    DEFF Research Database (Denmark)

    Jørgensen, Peter Løchte; Gatzert, Nadine

    This paper studies the economic implications of regulatory systems which allow equityholders of pension companies to not only charge a specific premium to compensate them for their higher risk (compared to policyholders), but also to accumulate these risk charges in a so-called shadow account...

  18. Dark matter trapping by stellar bars: the shadow bar

    Science.gov (United States)

    Petersen, Michael S.; Weinberg, Martin D.; Katz, Neal

    2016-12-01

    We investigate the complex interactions between the stellar disc and the dark-matter halo during bar formation and evolution using N-body simulations with fine temporal resolution and optimally chosen spatial resolution. We find that the forming stellar bar traps dark matter in the vicinity of the stellar bar into bar-supporting orbits. We call this feature the shadow bar. The shadow bar modifies both the location and magnitude of the angular momentum transfer between the disc and dark matter halo and adds 10 per cent to the mass of the stellar bar over 4 Gyr. The shadow bar is potentially observable by its density and velocity signature in spheroid stars and by direct dark matter detection experiments. Numerical tests demonstrate that the shadow bar can diminish the rate of angular momentum transport from the bar to the dark matter halo by more than a factor of 3 over the rate predicted by dynamical friction with an untrapped dark halo, and thus provides a possible physical explanation for the observed prevalence of fast bars in nature.

  19. Shadow-Based Vehicle Detection in Urban Traffic

    Directory of Open Access Journals (Sweden)

    Manuel Ibarra-Arenado

    2017-04-01

    Full Text Available Vehicle detection is a fundamental task in Forward Collision Avoiding Systems (FACS. Generally, vision-based vehicle detection methods consist of two stages: hypotheses generation and hypotheses verification. In this paper, we focus on the former, presenting a feature-based method for on-road vehicle detection in urban traffic. Hypotheses for vehicle candidates are generated according to the shadow under the vehicles by comparing pixel properties across the vertical intensity gradients caused by shadows on the road, and followed by intensity thresholding and morphological discrimination. Unlike methods that identify the shadow under a vehicle as a road region with intensity smaller than a coarse lower bound of the intensity for road, the thresholding strategy we propose determines a coarse upper bound of the intensity for shadow which reduces false positives rates. The experimental results are promising in terms of detection performance and robustness in day time under different weather conditions and cluttered scenarios to enable validation for the first stage of a complete FACS.

  20. Moon and Sun shadow observation with IceCube

    Energy Technology Data Exchange (ETDEWEB)

    Bos, Fabian; Tenholt, Frederik; Becker-Tjus, Julia [Theoretische Physik, Ruhr-Universitaet, Bochum (Germany); Westerhoff, Stefan [University of Wisconsin, Madison (United States); Collaboration: IceCube-Collaboration

    2015-07-01

    The analysis of the Moon shadow is a standard method in IceCube to determine the angular resolution and absolute pointing capabilities of the IceCube detector at the geographic South Pole. The Sun has not been used as a calibrator thus far, as its shadow is expected to be influenced by the solar magnetic field, which deflects the cosmic rays near the solar surface. This, on the other hand, provides indirect pieces of information on the magnetic field structure of the Sun. This talk shows a first analysis of the Sun shadow with IceCube data. The analysis is based on the data of the detector configurations with 79 (IC79) and 86 strings (IC86) from 2010 through 2012. To examine the shadows, a binned method is used to compare all events from one on-source with two off-source windows. For the IC40 and IC59 configuration a deficit with a statistical significance of more than 6σ was observed.

  1. Optical Algorithm for Cloud Shadow Detection Over Water

    Science.gov (United States)

    2013-02-01

    5] R. Amin, A. Gilerson, J. Zhou, B. Gross, F. Moshary, and S. Ahmed, "Im- pacts of atmospheric corrections on algal bloom detection techniques...optical algorithms to detect and classify harmful algal blooms from space. His current research interests include optical algorithm development...algorithm, remote sensing, shadow detection 16. SECURITY CLASSIFICATION OF: a. REPORT Unclassified b. ABSTRACT Unclassified c. THIS PAGE

  2. Shadow Formation at Preschool from a Socio-materiality Perspective

    Science.gov (United States)

    Impedovo, Maria Antonietta; Delserieys-Pedregosa, Alice; Jégou, Corinne; Ravanis, Konstantinos

    2016-05-01

    The paper is set in socio-material farming to offer a way of conceptualising actions and interactions of children in preschool involved in the understanding of scientific concepts. A model of early science education about the physical phenomena of shadow formation is implemented in group work in a French context. The research involved 44 children (13 females and 31 males) of 5-6 years old. The research design was organised in three video recording steps: pre-test, teaching session and post-test. We focus on the analysis of nine teaching sessions to investigate children's `understanding' of shadow formation. A descriptive and qualitative approach was used. In particular, we have identified three main categories (the interaction of the children with the tools, the embodiment and verbal dimension)—with respective indicators—to perform the analysis. From the results, all the categories explored seem to influence each other: all material, human and social dimensions contribute to the children's understanding of shadow formation. Also we have identified some elements that can serve as a potential source of improvement of the teaching session on shadow formation. Finally, the research provides insights on how to improve science activities in preschool with the aim of supporting early understanding of physical phenomena.

  3. Shadowing: Who Benefits and How? Uncovering a Booming EFL Teaching Technique for Listening Comprehension

    Science.gov (United States)

    Hamada, Yo

    2016-01-01

    This study examines common claims associated with shadowing. Studies in Japan conclude that shadowing is effective for improving learners' listening skills. Two common claims are that shadowing is effective for lower-proficiency learners and that it enhances learners' phoneme perception, thus improving listening comprehension skills. The former…

  4. Shadowing: Who Benefits and How? Uncovering a Booming EFL Teaching Technique for Listening Comprehension

    Science.gov (United States)

    Hamada, Yo

    2016-01-01

    This study examines common claims associated with shadowing. Studies in Japan conclude that shadowing is effective for improving learners' listening skills. Two common claims are that shadowing is effective for lower-proficiency learners and that it enhances learners' phoneme perception, thus improving listening comprehension skills. The former…

  5. School Socioeconomic Compositional Effect on Shadow Education Participation: Evidence from Japan

    Science.gov (United States)

    Matsuoka, Ryoji

    2015-01-01

    While shadow education, organized learning activities outside formal school, has grown greatly around the world, the relationship between formal schooling and shadow education has not been well investigated. This study is therefore intended to empirically test whether formal education's structure (i.e. tracking) affects students' shadow education…

  6. THE IMPACT OF SHADOWS IN THE RECENT INDIAN REMOTE SENSING SATELLITE IMAGERY

    Directory of Open Access Journals (Sweden)

    Mrs. G.Devi

    2011-08-01

    Full Text Available Remote sensing technology is emerging as a strong tool to extract information about the earth resources from the satellite imagery. However, shadow in fine resolution imagery affects this information. The fine resolution images from recent Indian Remote Sensing (IRS satellites are compared for the pixel values in shadow and non-shadow areas using histogram occupy large shadow area compared to Cartosat-1 of resolution 2.5m. The solar elevation angle is 41degree for which long shadows are formed in case of Cartosat-2 images. The solarelevation angle is 59 degree for which short shadows are formed in case of Cartosat-1 images. The shadows in an image are a function of the solar elevation angle, azimuth angle and spatial resolution etc. The fine resolution image (Cartosat-2 building and their shadow pixel values are analysed by bimodal histogram splitting technique. The shadow boundaries are extracted. Finally Gamma filtering applied and with the Gaussian enhancement technique the shadows are eliminated from Cartosat-2 image. The building shadow under objectcan be identified in this method. The main application in shadow elimination is used for urban map preparation and the object oriented classification.

  7. Skeletal Rigidity of Phylogenetic Trees

    CERN Document Server

    Cheng, Howard; Li, Brian; Risteski, Andrej

    2012-01-01

    Motivated by geometric origami and the straight skeleton construction, we outline a map between spaces of phylogenetic trees and spaces of planar polygons. The limitations of this map is studied through explicit examples, culminating in proving a structural rigidity result.

  8. Quantum Simulation of Phylogenetic Trees

    CERN Document Server

    Ellinas, Demosthenes

    2011-01-01

    Quantum simulations constructing probability tensors of biological multi-taxa in phylogenetic trees are proposed, in terms of positive trace preserving maps, describing evolving systems of quantum walks with multiple walkers. Basic phylogenetic models applying on trees of various topologies are simulated following appropriate decoherent quantum circuits. Quantum simulations of statistical inference for aligned sequences of biological characters are provided in terms of a quantum pruning map operating on likelihood operator observables, utilizing state-observable duality and measurement theory.

  9. 基于马尔可夫模型的多分辨率图像分割算法%Multi-resolution Image Segmentation Algorithm Based on Markov Model

    Institute of Scientific and Technical Information of China (English)

    肖然; 侯进

    2012-01-01

    为解决网像分割中过分割、欠分割和依赖初始分割问题,提出一种基于马尔可夫模型的多分辨率图像分割算法.利用变权重方法改进多分辨率马尔可夫随机场算法,结合曲波和小波变换对图像进行多分辨率分析,并通过区域合并减少图像中的区域数.实验结果表明,与经典算法相比,该算法的分割性能较好.%To solve the problem such as over-segmentation, under segmentation and dependence on initial segmented in image segmentation, this paper proposes a new multi-resolution image segmentation algorithm based on Markov model. It makes improvements on variable weight of Multi-resolution Markov Random Field(MRMRF) algorithm, combines curvelet transform and wavelet transform to multi-resolution analysis. It reduces area number of image by area merging. Experimental result proves the effectiveness of this algorithm compared with classical algorithms.

  10. Depth perception from moving cast shadow in macaque monkey.

    Science.gov (United States)

    Mizutani, Saneyuki; Usui, Nobuo; Yokota, Takanori; Mizusawa, Hidehiro; Taira, Masato; Katsuyama, Narumi

    2015-07-15

    In the present study, we investigate whether the macaque monkey can perceive motion in depth using a moving cast shadow. To accomplish this, we conducted two experiments. In the first experiment, an adult Japanese monkey was trained in a motion discrimination task in depth by binocular disparity. A square was presented on the display so that it appeared with a binocular disparity of 0.12 degrees (initial position), and moved toward (approaching) or away from (receding) the monkey for 1s. The monkey was trained to discriminate the approaching and receding motion of the square by GO/delayed GO-type responses. The monkey showed a significantly high accuracy rate in the task, and the performance was maintained when the position, color, and shape of the moving object were changed. In the next experiment, the change in the disparity was gradually decreased in the motion discrimination task. The results showed that the performance of the monkey declined as the distance of the approaching and receding motion of the square decreased from the initial position. However, when a moving cast shadow was added to the stimulus, the monkey responded to the motion in depth induced by the cast shadow in the same way as by binocular disparity; the reward was delivered randomly or given in all trials to prevent the learning of the 2D motion of the shadow in the frontal plane. These results suggest that the macaque monkey can perceive motion in depth using a moving cast shadow as well as using binocular disparity.

  11. Shadow Enhancers Are Pervasive Features of Developmental Regulatory Networks.

    Science.gov (United States)

    Cannavò, Enrico; Khoueiry, Pierre; Garfield, David A; Geeleher, Paul; Zichner, Thomas; Gustafson, E Hilary; Ciglar, Lucia; Korbel, Jan O; Furlong, Eileen E M

    2016-01-11

    Embryogenesis is remarkably robust to segregating mutations and environmental variation; under a range of conditions, embryos of a given species develop into stereotypically patterned organisms. Such robustness is thought to be conferred, in part, through elements within regulatory networks that perform similar, redundant tasks. Redundant enhancers (or "shadow" enhancers), for example, can confer precision and robustness to gene expression, at least at individual, well-studied loci. However, the extent to which enhancer redundancy exists and can thereby have a major impact on developmental robustness remains unknown. Here, we systematically assessed this, identifying over 1,000 predicted shadow enhancers during Drosophila mesoderm development. The activity of 23 elements, associated with five genes, was examined in transgenic embryos, while natural structural variation among individuals was used to assess their ability to buffer against genetic variation. Our results reveal three clear properties of enhancer redundancy within developmental systems. First, it is much more pervasive than previously anticipated, with 64% of loci examined having shadow enhancers. Their spatial redundancy is often partial in nature, while the non-overlapping function may explain why these enhancers are maintained within a population. Second, over 70% of loci do not follow the simple situation of having only two shadow enhancers-often there are three (rols), four (CadN and ade5), or five (Traf1), at least one of which can be deleted with no obvious phenotypic effects. Third, although shadow enhancers can buffer variation, patterns of segregating variation suggest that they play a more complex role in development than generally considered.

  12. In the Shadow/from the Shadow: The Principal as a Reflective Practitioner in Trinidad and Tobago

    Science.gov (United States)

    Bristol, Laurette; Esnard, Talia; Brown, Launcelot

    2015-01-01

    This case highlights a school principal's leading practice as she worked to transform the social and educational status of students, teachers, and community in a small urban primary school. We employ shadowing, a technique popularized in work-based education and photography, as reflective and research tools. Teaching notes provide insight into the…

  13. Shadows constructing a relationship between light and color pigments by physical and mathematical perspectives

    Science.gov (United States)

    Yurumezoglu, Kemal; Karabey, Burak; Yigit Koyunkaya, Melike

    2017-03-01

    Full shadows, partial shadows and multilayer shadows are explained based on the phenomenon of the linear dispersion of light. This paper focuses on progressing the understanding of shadows from physical and mathematical perspectives. A significant relationship between light and color pigments is demonstrated with the help of the concept of sets. This integration of physical and mathematical reasoning not only manages an operational approach to the concept of shadows, it also outputs a model that can be used in science, technology, engineering and mathematics (STEM) curricula by providing a concrete and physical example for abstract concept of the empty set.

  14. REAL-TIME SHADOW USING A COMBINATION OF STENCIL AND THE Z-BUFFER

    Directory of Open Access Journals (Sweden)

    Hoshang Kolivand

    2011-09-01

    Full Text Available In this paper we describe a real-time shadow generation with volume shadow algorithm in virtualenvironment that is illuminated by light sources with possibility to move separately. This algorithm uses thecombination of stencil and Z-buffers to generate shadow volume. It is simple to understand and implement.We have significantly improved and implemented recent techniques that are used in shadow volumealgorithms using stencil buffers especially in order to recognize silhouette, reduce the number of shadowpolygons and also redundant length of each triangles that makes the volume shadow. This work may beapplied in commercial games or other virtual reality systems

  15. Partial shadowing detection based on equivalent thermal voltage monitoring for PV module diagnostics

    DEFF Research Database (Denmark)

    Sera, Dezso; Teodorescu, Remus; Rodriguez, Pedro

    2009-01-01

    Partial shadowing of photovoltaic systems can overproportionally reduce the energy yield and lead to early ageing and failure of the shadowed cells. Large area shadows are relatively easy to detect due to the eminent power reduction and decrease of fill factor. However, small area partial shadows...... in a larger system do not have a very obvious effect on the output power or fill factor of the PV array and can remain undetected, leading to failure. In this paper a method for detecting small area partial shadows, based on equivalent thermal voltage, is presented. A simplified expression of the equivalent...

  16. Research on Multi-resolution Model Description of Train Operation Control System%列车运行控制系统多分辨率模型描述方法研究

    Institute of Scientific and Technical Information of China (English)

    苟晨曦; 蔡伯根

    2014-01-01

    Simulation of Research of train operation control systems is an efficient way to study train operation control systems.By the multi-resolution modeling theory,the accurant train operation control simulation mod-el can be constructed train operation control systems.Description of the multi-resolution model is the groundw-ork in study of the multi-resolution modeling theory.In this paper,in the light of the features of clear structure and distributed simulateion of train operation control systems,a new multi-resolution model description meth-od was proposed.With this method,multi-resolution modeling was separated from multi-resolution simulation while the concept of multi-resolution modeling space was put forward so that model structures in different reso-lutions could be converted dynamically during simulation without disturbing the operation of the simulation systems.The interface model was designed to maintain consistency between model and between models and simulation systems and to keep correctness of models data in model resolution switching.A simplified procees of train operation control was modeled and through simulation the advantages of the proposed method were demonstrated.%列车运行控制系统仿真是研究列控系统的一个十分有效的手段。采用多分辨率建模理论,能够准确建立列控系统仿真模型,而多分辨率模型描述是多分辨率建模理论研究的基础环节。针对列控系统结构明确、仿真分布式的特点,提出了一种新的多分辨率模型描述方法,该方法将多分辨率建模与多分辨率仿真进行区分,提出了多分辨率模型域的概念,从而在仿真过程中,不同分辨率模型结构可以实现动态切换且不影响仿真系统的正常运行,为了维护模型间以及模型与仿真系统的一致性,设计了接口模型,以此解决了模型分辨率切换的数据正确性问题。对列控系统运行的简单过程进行了建模,通过仿

  17. Shadow of a Kerr-Sen dilaton-axion Black Hole

    CERN Document Server

    Dastan, Sara; Soroushfar, Saheb

    2016-01-01

    We analyze the shadow of charged stationary axially symmetric space-time (Kerr-Sen dilaton-axion black hole). This black hole is defined by a mass $M$, a spin $a$ and $r_{\\alpha}=Q^{2}/M$, where $Q$ is the electric charge. Shadows are investigated in two conditions, i) for an observer at infinity in vacuum and ii) for an observer at infinity in the presence of plasma with radial power-low density. In vacuum, the shadow of this black hole depends on charge and spin parameter. We can see that, increasing electric charge, $Q$ decreases the size of shadow. Also, increasing spin parameter $a$ decreases the size of shadow. However, in existence of plasma, parameter of plasma like refraction index, $n$, playing an important role on shadows. In fact, decreasing refraction index decreases the size of shadow.

  18. Shadows and spirals in the protoplanetary disk HD 100453

    Science.gov (United States)

    Benisty, M.; Stolker, T.; Pohl, A.; de Boer, J.; Lesur, G.; Dominik, C.; Dullemond, C. P.; Langlois, M.; Min, M.; Wagner, K.; Henning, T.; Juhasz, A.; Pinilla, P.; Facchini, S.; Apai, D.; van Boekel, R.; Garufi, A.; Ginski, C.; Ménard, F.; Pinte, C.; Quanz, S. P.; Zurlo, A.; Boccaletti, A.; Bonnefoy, M.; Beuzit, J. L.; Chauvin, G.; Cudel, M.; Desidera, S.; Feldt, M.; Fontanive, C.; Gratton, R.; Kasper, M.; Lagrange, A.-M.; LeCoroller, H.; Mouillet, D.; Mesa, D.; Sissa, E.; Vigan, A.; Antichi, J.; Buey, T.; Fusco, T.; Gisler, D.; Llored, M.; Magnard, Y.; Moeller-Nilsson, O.; Pragt, J.; Roelfsema, R.; Sauvage, J.-F.; Wildi, F.

    2017-01-01

    Context. Understanding the diversity of planets requires studying the morphology and physical conditions in the protoplanetary disks in which they form. Aims: We aim to study the structure of the 10 Myr old protoplanetary disk HD 100453, to detect features that can trace disk evolution and to understand the mechanisms that drive these features. Methods: We observed HD 100453 in polarized scattered light with VLT/SPHERE at optical (0.6 μm, 0.8 μm) and near-infrared (1.2 μm) wavelengths, reaching an angular resolution of 0.02'', and an inner working angle of 0.09''. Results: We spatially resolve the disk around HD 100453, and detect polarized scattered light up to 0.42'' ( 48 au). We detect a cavity, a rim with azimuthal brightness variations at an inclination of 38° with respect to our line of sight, two shadows and two symmetric spiral arms. The spiral arms originate near the location of the shadows, close to the semi major axis. We detect a faint feature in the SW that can be interpreted as the scattering surface of the bottom side of the disk, if the disk is tidally truncated by the M-dwarf companion currently seen at a projected distance of 119 au. We construct a radiative transfer model that accounts for the main characteristics of the features with an inner and outer disk misaligned by 72°. The azimuthal brightness variations along the rim are well reproduced with the scattering phase function of the model. While spirals can be triggered by the tidal interaction with the companion, the close proximity of the spirals to the shadows suggests that the shadows could also play a role. The change in stellar illumination along the rim induces an azimuthal variation of the scale height that can contribute to the brightness variations. Conclusions: Dark regions in polarized images of transition disks are now detected in a handful of disks and often interpreted as shadows due to a misaligned inner disk. However, the origin of such a misalignment in HD 100453, and

  19. Riddles in the Dark: Imaging Inside Mercury's Permanently Shadowed Craters

    Science.gov (United States)

    Ernst, C. M.; Chabot, N. L.; Denevi, B. W.; Nair, H.; Deutsch, A. N.; Murchie, S. L.; Robinson, M. S.; Blewett, D. T.; Head, J. W.; Harmon, J. K.; Neumann, G. A.; Solomon, S. C.

    2013-12-01

    Numerous lines of evidence independently point to the presence of water ice in Mercury's polar regions: Earth-based radar shows radar-bright regions; Mariner 10 and MESSENGER Mercury Dual Imaging System (MDIS) images reveal that these regions are permanently (south polar region) or persistently (north polar region) shadowed; neutron spectrometry indicates hydrogen-rich material; thermal models support the presence of water ice; and Mercury Laser Altimeter (MLA) reflectance measurements at 1064 nm show high and low reflectance deposits consistent in location to where models predict surface and buried water ice, respectively. Throughout 2013, MESSENGER executed a campaign dedicated to imaging the permanently shadowed crater floors of Mercury's north polar region using sunlight scattered from nearby terrain. The campaign makes use of the broadband clear filter (central wavelength 700 nm, bandwidth 600 nm) of the MDIS wide-angle camera (WAC) to target and image radar-bright areas within all host craters > 10 km in diameter under multiple lighting conditions. To date, MESSENGER has imaged the interiors of nearly 20 craters that host radar-bright deposits, including the largest such deposits near the north pole that are likely to host surface water ice. The images reveal a variety of surface morphologies, ranging from the smooth crater floor of the fresh Kandinsky crater, to the moderately cratered floor of Tolkien crater, and to the battered floor of Prokofiev crater, in which the permanently shadowed region does not differ morphologically from the rest of the crater floor. Thus, no distinct morphology is identified in association with polar deposits, and craters hosting such material span the typical range of degradation states relative to their illuminated counterparts. MDIS images also reveal albedo differences in craters with floors not fully in permanent shadow. Prokofiev provides a special environment for viewing a radar- and MLA-bright region suspected to host

  20. apex: phylogenetics with multiple genes.

    Science.gov (United States)

    Jombart, Thibaut; Archer, Frederick; Schliep, Klaus; Kamvar, Zhian; Harris, Rebecca; Paradis, Emmanuel; Goudet, Jérome; Lapp, Hilmar

    2017-01-01

    Genetic sequences of multiple genes are becoming increasingly common for a wide range of organisms including viruses, bacteria and eukaryotes. While such data may sometimes be treated as a single locus, in practice, a number of biological and statistical phenomena can lead to phylogenetic incongruence. In such cases, different loci should, at least as a preliminary step, be examined and analysed separately. The r software has become a popular platform for phylogenetics, with several packages implementing distance-based, parsimony and likelihood-based phylogenetic reconstruction, and an even greater number of packages implementing phylogenetic comparative methods. Unfortunately, basic data structures and tools for analysing multiple genes have so far been lacking, thereby limiting potential for investigating phylogenetic incongruence. In this study, we introduce the new r package apex to fill this gap. apex implements new object classes, which extend existing standards for storing DNA and amino acid sequences, and provides a number of convenient tools for handling, visualizing and analysing these data. In this study, we introduce the main features of the package and illustrate its functionalities through the analysis of a simple data set.

  1. Bosque: integrated phylogenetic analysis software.

    Science.gov (United States)

    Ramírez-Flandes, Salvador; Ulloa, Osvaldo

    2008-11-01

    Phylogenetic analyses today involve dealing with computer files in different formats and often several computer programs. Although some widely used applications have integrated important functionalities for such analyses, they still work with local resources only: input/output files (users have to manage them) and local computing (users have sometimes to leave their programs, on their desktop computers, running for extended periods of time). To address these problems we have developed 'Bosque', a multi-platform client-server software that performs standard phylogenetic tasks either locally or remotely on servers, and integrates the results on a local relational database. Bosque performs sequence alignments and graphical visualization and editing of trees, thus providing a powerful environment that integrates all the steps of phylogenetic analyses. http://bosque.udec.cl

  2. Medium Access Control for Opportunistic Concurrent Transmissions under Shadowing Channels.

    Science.gov (United States)

    Son, In Keun; Mao, Shiwen; Hur, Seung Min

    2009-01-01

    We study the problem of how to alleviate the exposed terminal effect in multi-hop wireless networks in the presence of log-normal shadowing channels. Assuming node location information, we propose an extension of the IEEE 802.11 MAC protocol that sched-ules concurrent transmissions in the presence of log-normal shadowing, thus mitigating the exposed terminal problem and improving network throughput and delay performance. We observe considerable improvements in throughput and delay achieved over the IEEE 802.11 MAC under various network topologies and channel conditions in ns-2 simulations, which justify the importance of considering channel randomness in MAC protocol design for multi-hop wireless networks.

  3. Least Squares Shadowing for Sensitivity Analysis of Turbulent Fluid Flows

    CERN Document Server

    Blonigan, Patrick; Wang, Qiqi

    2014-01-01

    Computational methods for sensitivity analysis are invaluable tools for aerodynamics research and engineering design. However, traditional sensitivity analysis methods break down when applied to long-time averaged quantities in turbulent fluid flow fields, specifically those obtained using high-fidelity turbulence simulations. This is because of a number of dynamical properties of turbulent and chaotic fluid flows, most importantly high sensitivity of the initial value problem, popularly known as the "butterfly effect". The recently developed least squares shadowing (LSS) method avoids the issues encountered by traditional sensitivity analysis methods by approximating the "shadow trajectory" in phase space, avoiding the high sensitivity of the initial value problem. The following paper discusses how the least squares problem associated with LSS is solved. Two methods are presented and are demonstrated on a simulation of homogeneous isotropic turbulence and the Kuramoto-Sivashinsky (KS) equation, a 4th order c...

  4. X-Ray Shadowing Experiments Toward Infrared Dark Clouds

    Science.gov (United States)

    Anderson, L. E.; Snowden, S.; Bania, T. M.

    2009-01-01

    We searched for X-ray shadowing toward two infrared dark clouds (IRDCs) using the MOS detectors on XMM-Newton to learn about the Galactic distribution of X-ray emitting plasma. IRDCs make ideal X-ray shadowing targets of 3/4 keY photons due to their high column densities, relatively large angular sizes, and known kinematic distances. Here we focus on two clouds near 30 deg Galactic longitude at distances of 2 and 5 kpc from the Sun. We derive the foreground and background column densities of molecular and atomic gas in the direction of the clouds. We find that the 3/4 ke V emission must be distributed throughout the Galactic disk. It is therefore linked to the structure of the cooler material of the ISM, and to the birth of stars.

  5. The permanently shadowed regions of dwarf planet Ceres

    Science.gov (United States)

    Schorghofer, Norbert; Mazarico, Erwan; Platz, Thomas; Preusker, Frank; Schröder, Stefan E.; Raymond, Carol A.; Russell, Christopher T.

    2016-07-01

    Ceres has only a small spin axis tilt (4°), and craters near its rotational poles can experience permanent shadow and trap volatiles, as is the case on Mercury and on Earth's Moon. Topography derived from stereo imaging by the Dawn spacecraft is used to calculate direct solar irradiance that defines the extent of the permanently shadowed regions (PSRs). In the northern polar region, PSRs cover ˜1800 km2 or 0.13% of the hemisphere, and most of the PSRs are cold enough to trap water ice over geological time periods. Based on modeling of the water exosphere, water molecules seasonally reside around the winter pole and ultimately an estimated 0.14% of molecules get trapped. Even for the lowest estimates of the amount of available water, this predicts accumulation rates in excess of loss rates, and hence, there should be fresh ice deposits in the cold traps.

  6. Simulation of Hard Shadows on Large Spherical Terrains

    Science.gov (United States)

    Aslandere, Turgay; Flatken, Markus; Gerndt, Andreas

    2016-12-01

    Real-time rendering of high precision shadows using digital terrain models as input data is a challenging task. Especially when interactivity is targeted and level of detail data structures are utilized to tackle huge amount of data. In this paper, we present a real-time rendering approach for the computation of hard shadows using large scale digital terrain data obtained by satellite imagery. Our approach is based on an extended horizon mapping algorithm that avoids costly pre-computations and ensures high accuracy. This algorithm is further developed to handle large data. The proposed algorithms take the surface curvature of the large spherical bodies into account during the computation. The performance issues are discussed and the results are presented. The generated images can be exploited in 3D research and aerospace related areas.

  7. Shadow Areas Robust Matching Among Image Sequence in Planetary Landing

    Science.gov (United States)

    Ruoyan, Wei; Xiaogang, Ruan; Naigong, Yu; Xiaoqing, Zhu; Jia, Lin

    2017-01-01

    In this paper, an approach for robust matching shadow areas in autonomous visual navigation and planetary landing is proposed. The approach begins with detecting shadow areas, which are extracted by Maximally Stable Extremal Regions (MSER). Then, an affine normalization algorithm is applied to normalize the areas. Thirdly, a descriptor called Multiple Angles-SIFT (MA-SIFT) that coming from SIFT is proposed, the descriptor can extract more features of an area. Finally, for eliminating the influence of outliers, a method of improved RANSAC based on Skinner Operation Condition is proposed to extract inliers. At last, series of experiments are conducted to test the performance of the approach this paper proposed, the results show that the approach can maintain the matching accuracy at a high level even the differences among the images are obvious with no attitude measurements supplied.

  8. The Effect of Shadow Economy – Country'S Tax Losses

    Directory of Open Access Journals (Sweden)

    Jolita Krumplytė

    2011-04-01

    Full Text Available The article analyzes the content of shadow economy through the prism of the tax administration. The author provides the limitations of the study and methodologically based relationship between the shadow economy and the tax revenue not to be received to the national consolidate budget. Country’s tax losses (tax gap is the amount of the tax revenue that is not received to the country's consolidated budget in the tax non-payment effects: tax avoidance and tax evasion. Tax losses (tax gap is treated as the difference between the amount of potential taxes and contributions that could be collected if the taxpayers correctly calculated and paid on time in accordance with the provisions of the legislation and actually paid taxes and contributions.Article in Lithuanian

  9. Shadow photogrammetric apparatus for the quantitative evaluation of corneal buttons.

    Science.gov (United States)

    Denham, D; Mandelbaum, S; Parel, J M; Holland, S; Pflugfelder, S; Parel, J M

    1989-11-01

    We have developed a technique for the accurate, quantitative, geometric evaluation of trephined and punched corneal buttons. A magnified shadow of the frontal and edge views of a corneal button mounted on the rotary stage of a modified optical comparator is projected onto the screen of the comparator and photographed. This process takes approximately three minutes. The diameters and edge profile at any meridian photographed can subsequently be analyzed from the film. The precision in measuring the diameters of well cut corneal buttons is +/- 23 microns, and in measuring the angle of the edge profile is +/- 1 degree. Statistical analysis of inter observer variability indicated excellent reproducibility of measurements. Shadow photogrammetry offers a standardized, accurate, and reproducible method for analysis of corneal trephination.

  10. Wake models developed during the Wind Shadow project

    Energy Technology Data Exchange (ETDEWEB)

    Larsen, S.; Ott, S.; Pena, A.; Berg, J.; Nielsen, M.; Rathmann, O.; Joergensen, H.

    2011-11-15

    The Wind Shadow project has developed and validated improved models for determining the wakes losses, and thereby the array efficiency of very large, closely packed wind farms. The rationale behind the project has been that the existing software has been covering these types of wind farms poorly, both with respect to the densely packed turbines and the large fetches needed to describe the collective shadow effects of one farm to the next. Further the project has developed the necessary software for the use of the models. Guidelines with recommendations for the use of the models are included in the model deliverables. The project has been carried out as a collaborative project between Risoe DTU, DONG, Vattenfall, DNV and VESTAS, and it has been financed by energinet.dk grant no. 10086. (Author)

  11. Examining the Fidelity of Climate model via Shadowing Time

    Science.gov (United States)

    Du, H.; Smith, L. A.

    2015-12-01

    Fully fledged climate models provide the best available simulations for reflecting the future, yet we have scant insight into their fidelity, in particular as to the duration into the future at which the real world should be expected to evolve in a manner today's models cannot foresee. We know now that our best available models are not adequate for many sought after purposes. To throw some light on the maximum fidelity expected from a given generation of models, and thereby aid both policy making and model development, we can test the weaknesses of a model as a dynamical system to get an informed idea of its potential applicability at various lead times. Shadowing times reflect the duration on which a GCM reflects the observations; extracting the shortcomings of the model which limit shadowing times allows informed speculation regarding the fidelity of the model in the future. More specifically, the relevant phenomena limiting model fidelity can be learned by identifying the reasons models cannot shadow; the time scales on which feedbacks on the system (which are not active in the model) are likely to result in model irrelevance can be discerned. The methodology is developed in the "low dimensional laboratory" of relatively simple dynamical systems, for example Lorenz 95 systems. The results are presented in Lorenz 95 systems, high dimensional fluid dynamical simulations of rotating annulus and GCMs. There are severe limits on the light shadowing experiments can shine on GCM predictions. Never the less, they appear to be one of the brightest lights we can shine to illuminate the likely fidelity of GCM extrapolations into the future.

  12. Shadow Banking – Developments in Times of Financial Crisis

    Directory of Open Access Journals (Sweden)

    Bogdan Munteanu

    2016-01-01

    The paper considers the following entities and activities, without limitation to or completenessof viewpoints: finance companies, asset backed financial instruments, structured investments,financing vehicles, money market funds, asset managers, credit hedge funds and venture capital,providing characteristics of shadow banking and their economic functions relative to the classicbanking system, as they pose a systemic risk due to asymmetric information and gaps created inmatching liquidity tenures with duration, by using synthetic leverage finance.

  13. Residual stress measurement in silicon sheet by shadow moire interferometry

    Science.gov (United States)

    Kwon, Y.; Danyluk, S.; Bucciarelli, L.; Kalejs, J. P.

    1987-01-01

    A shadow moire interferometry technique has been developed to measure residual strain in thin silicon sheet. The curvature of a segment of sheet undergoing four-point bending is analyzed to include the applied bending moments, the in-plane residual stresses, and the 'end effect' of the sheet since it is of finite length. The technique is applied to obtain residual stress distributions for silicon sheet grown by the edge-defined film-fed growth technique.

  14. Nuclear shadowing and antishadowing in a unitarized BFKL equation

    Institute of Scientific and Technical Information of China (English)

    RUAN Jian-Hong; SHEN Zhen-Qi; ZHU Wei

    2008-01-01

    The nuclear shadowing and antishadowing effects are explained by a unitarized BFKL equation.The Q2-and x-variations of the nuclear parton distributions are detailed based on the level of the unintegrated gluon distribution.In particular,the asymptotical behavior of the unintegrated gluon distribution near the saturation limit in nuclear targets is studied. Our results in the nuclear targets are insensitive to the input distributions if the parameters are fixed by the data of a flee proton.

  15. Mirror and Shadow: Social Media in the Burning Man Community

    OpenAIRE

    Aveline, Dawn

    2012-01-01

    Social media forms a mirror for the present and casts a shadow to the future. This exploratory case study focuses on the social media documents created by participants and organizers of the Burning Man festival, a temporary city of 50,000 inhabitants constructed annually in a remote Nevada desert. This ephemeral community develops through the collaborative, volunteer efforts of its citizens. Attendees generate all the content of the event, including large-scale sculptures, performances, and u...

  16. Shadow Prices of Selected Agricultural Commodities – The Czech Case

    OpenAIRE

    Patrik Sieber; Karina Pohlová; Ondřej Chaloupka

    2016-01-01

    The main objective of the paper is to contribute to practical applicability of the CBA in the agricultural sector by exploring the chances to estimate Czech social values of selected agricultural commodities using available statistical data. More specifically, we try to analyse for which commodities secondary data sets are available from which we may deduce the estimates of shadow price ratios, then to estimate SPRs for selected agricultural commodities and to analyse and discuss the ap...

  17. The Shadow Emirate: The Taliban’s Return to Power

    Science.gov (United States)

    2013-06-01

    depends on leaders with charisma and bravado, which at times is at odds with the upper echelon leadership.104 The fighters make up the very bottom of the...Afghanistan: Organizations, Operations, and Shadow Governance,” Institute for the Study of War: Military Analysis and Education for Civilian Leaders ...Supreme Leader , Mullah Omar. Although a bit dated, the material provides a good stepping off point to analyze the group’s dynamic and determine if and how

  18. Interpreting the universal phylogenetic tree

    Science.gov (United States)

    Woese, C. R.

    2000-01-01

    The universal phylogenetic tree not only spans all extant life, but its root and earliest branchings represent stages in the evolutionary process before modern cell types had come into being. The evolution of the cell is an interplay between vertically derived and horizontally acquired variation. Primitive cellular entities were necessarily simpler and more modular in design than are modern cells. Consequently, horizontal gene transfer early on was pervasive, dominating the evolutionary dynamic. The root of the universal phylogenetic tree represents the first stage in cellular evolution when the evolving cell became sufficiently integrated and stable to the erosive effects of horizontal gene transfer that true organismal lineages could exist.

  19. Acoustic Shadows: An Auditory Exploration of the Sense of Space

    Directory of Open Access Journals (Sweden)

    Frank Dufour

    2011-12-01

    Full Text Available This paper examines the question of auditory detection of the movements of silent objects in noisy environments. The approach to studying and exploring this phenomenon is primarily based on the framework of the ecology of perception defined by James Gibson (Gibson, 1979 in the sense that it focuses on the direct auditory perception of events, or “structured energy that specifies properties of the environment” (Michaels & Carello, 1981 P. 157. The goal of this study is triple: -Theoretical; for various reasons, this kind of acoustic situations has not been extensively studied by traditional acoustics and psychoacoustics, therefore, this project demonstrates and supports the pertinence of the Ecology of Perception for the description and explanation of such complex phenomena. -Practical; like echolocation, perception of acoustic shadows can be improved by practice, this project intends to contribute to the acknowledgment of this way of listening and to help individuals placed in noisy environments without the support of vision acquiring a detailed detection of the movements occurring in these environments. -Artistic; this project explores a new artistic expression based on the creation and exploration of complex multisensory environments. Acoustic Shadows, a multimedia interactive composition is being developed on the premises of the ecological approach to perception. The last dimension of this project is meant to be a contribution to the sonic representation of space in films and in computer generated virtual environments by producing simulations of acoustic shadows.

  20. Real-time simulation of thermal shadows with EMIT

    Science.gov (United States)

    Klein, Andreas; Oberhofer, Stefan; Schätz, Peter; Nischwitz, Alfred; Obermeier, Paul

    2016-05-01

    Modern missile systems use infrared imaging for tracking or target detection algorithms. The development and validation processes of these missile systems need high fidelity simulations capable of stimulating the sensors in real-time with infrared image sequences from a synthetic 3D environment. The Extensible Multispectral Image Generation Toolset (EMIT) is a modular software library developed at MBDA Germany for the generation of physics-based infrared images in real-time. EMIT is able to render radiance images in full 32-bit floating point precision using state of the art computer graphics cards and advanced shader programs. An important functionality of an infrared image generation toolset is the simulation of thermal shadows as these may cause matching errors in tracking algorithms. However, for real-time simulations, such as hardware in the loop simulations (HWIL) of infrared seekers, thermal shadows are often neglected or precomputed as they require a thermal balance calculation in four-dimensions (3D geometry in one-dimensional time up to several hours in the past). In this paper we will show the novel real-time thermal simulation of EMIT. Our thermal simulation is capable of simulating thermal effects in real-time environments, such as thermal shadows resulting from the occlusion of direct and indirect irradiance. We conclude our paper with the practical use of EMIT in a missile HWIL simulation.

  1. COMPUTER-AIDED DETECTION OF ACINAR SHADOWS IN CHEST RADIOGRAPHS

    Directory of Open Access Journals (Sweden)

    Tao Xu

    2013-05-01

    Full Text Available Despite the technological advances in medical diagnosis, accurate detection of infectious tuberculosis (TB still poses challenges due to complex image features and thus infectious TB continues to be a public health problem of global proportions. Currently, the detection of TB is mainly conducted visually by radiologists examining chest radiographs (CXRs. To reduce the backlog of CXR examination and provide more precise quantitative assessment, computer-aided detection (CAD systems for potential lung lesions have been increasingly adopted and commercialized for clinical practice. CADs work as supporting tools to alert radiologists on suspected features that could have easily been neglected. In this paper, an effective CAD system aimed for acinar shadow regions detection in CXRs is proposed. This system exploits textural and photometric features analysis techniques which include local binary pattern (LBP, grey level co-occurrence matrix (GLCM and histogram of oriented gradients (HOG to analyze target regions in CXRs. Classification of acinar shadows using Adaboost is then deployed to verify the performance of a combination of these techniques. Comparative study in different image databases shows that the proposed CAD system delivers consistent high accuracy in detecting acinar shadows.

  2. SHADOW DETECTION FROM VERY HIGH RESOLUTON SATELLITE IMAGE USING GRABCUT SEGMENTATION AND RATIO-BAND ALGORITHMS

    Directory of Open Access Journals (Sweden)

    N. M. S. M. Kadhim

    2015-03-01

    Full Text Available Very-High-Resolution (VHR satellite imagery is a powerful source of data for detecting and extracting information about urban constructions. Shadow in the VHR satellite imageries provides vital information on urban construction forms, illumination direction, and the spatial distribution of the objects that can help to further understanding of the built environment. However, to extract shadows, the automated detection of shadows from images must be accurate. This paper reviews current automatic approaches that have been used for shadow detection from VHR satellite images and comprises two main parts. In the first part, shadow concepts are presented in terms of shadow appearance in the VHR satellite imageries, current shadow detection methods, and the usefulness of shadow detection in urban environments. In the second part, we adopted two approaches which are considered current state-of-the-art shadow detection, and segmentation algorithms using WorldView-3 and Quickbird images. In the first approach, the ratios between the NIR and visible bands were computed on a pixel-by-pixel basis, which allows for disambiguation between shadows and dark objects. To obtain an accurate shadow candidate map, we further refine the shadow map after applying the ratio algorithm on the Quickbird image. The second selected approach is the GrabCut segmentation approach for examining its performance in detecting the shadow regions of urban objects using the true colour image from WorldView-3. Further refinement was applied to attain a segmented shadow map. Although the detection of shadow regions is a very difficult task when they are derived from a VHR satellite image that comprises a visible spectrum range (RGB true colour, the results demonstrate that the detection of shadow regions in the WorldView-3 image is a reasonable separation from other objects by applying the GrabCut algorithm. In addition, the derived shadow map from the Quickbird image indicates

  3. Evaluating the Effects of Shadow Detection on QuickBird Image Classification and Spectroradiometric Restoration

    Directory of Open Access Journals (Sweden)

    Marvin E. Bauer

    2013-09-01

    Full Text Available Shadows in high resolution imagery create significant problems for urban land cover classification and environmental application. We first investigated whether shadows were intrinsically different and hypothetically possible to separate from each other with ground spectral measurements. Both pixel-based and object-oriented methods were used to evaluate the effects of shadow detection on QuickBird image classification and spectroradiometric restoration. In each method, shadows were detected and separated either with or without histogram thresholding, and subsequently corrected with a k-nearest neighbor algorithm and a linear correlation correction. The results showed that shadows had distinct spectroradiometric characteristics, thus, could be detected with an optimal brightness threshold and further differentiated with a scene-based near infrared ratio. The pixel-based methods generally recognized more shadow areas and with statistically higher accuracy than the object-oriented methods. The effects of the prior shadow thresholding were not statistically significant. The accuracy of the final land cover classification, after accounting for the shadow detection and separation, was significantly higher for the pixel-based methods than for the object-oriented methods, although both achieved similar accuracy for the non-shadow classes. Both radiometric restoration algorithms significantly reduced shadow areas in the original satellite images.

  4. Shadow of the rotating black hole with quintessential energy in the presence of plasma

    Science.gov (United States)

    Abdujabbarov, Ahmadjon; Toshmatov, Bobir; Stuchlík, Zdeněk; Ahmedov, Bobomurat

    We study the shadow of the rotating black hole with quintessential energy (i) in vacuum, (ii) in the presence of plasma with radial power-law density. For the vacuum case, the quintessential field parameter of the rotating black hole significantly changes the shape of the shadow. With increasing quintessential field parameter, the radius of the shadow also increases. With the increase of the radius of the shadow of the rotating black hole, the quintessential field parameter causes decrease of the distortion of the shadow shape: in the presence of the quintessential field parameter, the shadow of the fast rotating black hole becomes too close to the circle. We assume the distant observer of the black hole shadow to be located near the so-called static radius where the gravitational attraction of the black hole is just balanced by the cosmic repulsion. The shape and size of the shadow of quintessential rotating black hole surrounded by plasma depends on (i) plasma parameters, (ii) black hole spin and (iii) quintessential field parameter. With the increase of the plasma refraction index, the apparent radius of the shadow increases. However, for the large values of the quintessential field parameter, the change of the black hole shadow shape due to the presence of plasma is not significant, i.e. the effect of the quintessential field parameter dominates over the plasma effect.

  5. Anisotropic Scattering Shadow Compensation Method for Remote Sensing Image with Consideration of Terrain

    Science.gov (United States)

    Wang, Qiongjie; Yan, Li

    2016-06-01

    With the rapid development of sensor networks and earth observation technology, a large quantity of high resolution remote sensing data is available. However, the influence of shadow has become increasingly greater due to the higher resolution shows more complex and detailed land cover, especially under the shadow. Shadow areas usually have lower intensity and fuzzy boundary, which make the images hard to interpret automatically. In this paper, a simple and effective shadow (including soft shadow) detection and compensation method is proposed based on normal data, Digital Elevation Model (DEM) and sun position. First, we use high accuracy DEM and sun position to rebuild the geometric relationship between surface and sun at the time the image shoot and get the hard shadow boundary and sky view factor (SVF) of each pixel. Anisotropic scattering assumption is accepted to determine the soft shadow factor mainly affected by diffuse radiation. Finally, an easy radiation transmission model is used to compensate the shadow area. Compared with the spectral detection method, our detection method has strict theoretical basis, reliable compensation result and minor affected by the image quality. The compensation strategy can effectively improve the radiation intensity of shadow area, reduce the information loss brought by shadow and improve the robustness and efficiency of the classification algorithms.

  6. SOCIO-ECONOMIC NATURE OF SHADOW ECONOMY AND CAUSES OF ITS DEVELOPMENT IN ENTREPRENEURSHIP

    Directory of Open Access Journals (Sweden)

    I. Mazur

    2017-01-01

    Full Text Available The socio-economic nature of the shadow economy is revealed. The shadow economy has both positive and negative signs for the society; the possibility for the population to survive in conditions of economic crisis, reducing transaction costs authors refer to positive signs, and the destructive economic development to negative. The common (prohibitions and restrictions and partial (high tax burden and inefficient system of its administration; numerous bureaucratic procedures; mistrust to the government institutions and the judiciary; corruption in all levels of the governance, etc. causes of the shadow economy in entrepreneurship are disclosed. It is argued that the shadow economy is neither a sector nor a certain part of the legal economy, it can be in any sector of the legal economy closely interlaced with it, and therefore its limits cannot be clearly identified (determine in the formal economy. The shadow economy is not possible to determine especially in the information society. The categories of the shadow economy and its structuring are suggested. It has been researched the historical roots of the shadow economy spread in entrepreneurship, and lie in the shadow of public-private partnership which carries interests of "civil servant-entrepreneurs" and allows to manage state resources and control market. Therefore, the shadow policy creates favorable conditions for the entrepreneurs to work in the shadow. At the same time, access to the shadow entails stricter regulation by the state. It is proved that corruption is a part of the shadow economy, not an independent phenomenon, so they should be research comprehensively and systematically. Instead of overcoming the shadow economy and its component - corruption has been suggested to establish favorable business environment for their unfavorable existence, that is to carry out deshadowing of the economy.

  7. Evolutionary Phylogenetic Networks: Models and Issues

    Science.gov (United States)

    Nakhleh, Luay

    Phylogenetic networks are special graphs that generalize phylogenetic trees to allow for modeling of non-treelike evolutionary histories. The ability to sequence multiple genetic markers from a set of organisms and the conflicting evolutionary signals that these markers provide in many cases, have propelled research and interest in phylogenetic networks to the forefront in computational phylogenetics. Nonetheless, the term 'phylogenetic network' has been generically used to refer to a class of models whose core shared property is tree generalization. Several excellent surveys of the different flavors of phylogenetic networks and methods for their reconstruction have been written recently. However, unlike these surveys, this chapte focuses specifically on one type of phylogenetic networks, namely evolutionary phylogenetic networks, which explicitly model reticulate evolutionary events. Further, this chapter focuses less on surveying existing tools, and addresses in more detail issues that are central to the accurate reconstruction of phylogenetic networks.

  8. Phylogenetic relationships among Maloideae species

    Science.gov (United States)

    The Maloideae is a highly diverse sub-family of the Rosaceae containing several agronomically important species (Malus sp. and Pyrus sp.) and their wild relatives. Previous phylogenetic work within the group has revealed extensive intergeneric hybridization and polyploidization. In order to develop...

  9. Phylogenetics of neotropical Platymiscium (Leguminosae

    DEFF Research Database (Denmark)

    Saslis-Lagoudakis, C. Haris; Chase, Mark W; Robinson, Daniel N

    2008-01-01

    Platymiscium is a neotropical legume genus of forest trees in the Pterocarpus clade of the pantropical "dalbergioid" clade. It comprises 19 species (29 taxa), distributed from Mexico to southern Brazil. This study presents a molecular phylogenetic analysis of Platymiscium and allies inferred from...

  10. EU-FP7-iMARS: analysis of Mars multi-resolution images using auto-coregistration, data mining and crowd source techniques

    Science.gov (United States)

    Ivanov, Anton; Muller, Jan-Peter; Tao, Yu; Kim, Jung-Rack; Gwinner, Klaus; Van Gasselt, Stephan; Morley, Jeremy; Houghton, Robert; Bamford, Steven; Sidiropoulos, Panagiotis; Fanara, Lida; Waenlish, Marita; Walter, Sebastian; Steinkert, Ralf; Schreiner, Bjorn; Cantini, Federico; Wardlaw, Jessica; Sprinks, James; Giordano, Michele; Marsh, Stuart

    2016-07-01

    Understanding planetary atmosphere-surface and extra-terrestrial-surface formation processes within our Solar System is one of the fundamental goals of planetary science research. There has been a revolution in planetary surface observations over the last 15 years, especially in 3D imaging of surface shape. This has led to the ability to be able to overlay different epochs back in time to the mid 1970s, to examine time-varying changes, such as the recent discovery of mass movement, tracking inter-year seasonal changes and looking for occurrences of fresh craters. Within the EU FP-7 iMars project, UCL have developed a fully automated multi-resolution DTM processing chain, called the Co-registration ASP-Gotcha Optimised (CASP-GO), based on the open source NASA Ames Stereo Pipeline (ASP), which is being applied to the production of planetwide DTMs and ORIs (OrthoRectified Images) from CTX and HiRISE. Alongside the production of individual strip CTX & HiRISE DTMs & ORIs, DLR have processed HRSC mosaics of ORIs and DTMs for complete areas in a consistent manner using photogrammetric bundle block adjustment techniques. A novel automated co-registration and orthorectification chain has been developed and is being applied to level-1 EDR images taken by the 4 NASA orbital cameras since 1976 using the HRSC map products (both mosaics and orbital strips) as a map-base. The project has also included Mars Radar profiles from Mars Express and Mars Reconnaissance Orbiter missions. A webGIS has been developed for displaying this time sequence of imagery and a demonstration will be shown applied to one of the map-sheets. Automated quality control techniques are applied to screen for suitable images and these are extended to detect temporal changes in features on the surface such as mass movements, streaks, spiders, impact craters, CO2 geysers and Swiss Cheese terrain. These data mining techniques are then being employed within a citizen science project within the Zooniverse family

  11. Real-Time Projection Shadow with Respect to Sun Position in Virtual Environments

    Directory of Open Access Journals (Sweden)

    Hoshang Kolivand

    2011-11-01

    Full Text Available This paper proposes a real-time software for outdoor rendering to control the shadows position with effect of sun's position. The position of sun plays an important rule for outdoor games. Calculation of sun's position, as a result, position and length of shadows require a lot of attention and preciseness. Julian dating is used to calculate the sun's position in the virtual dome. In addition, of computer graphics, building design is another field that this paper contributes on it. To create shadow, projection shadow is proposed. By calculating the sun's position in the specific date, time and location on the earth, shadow is generated. Length and angle of shadow are two parameters measured for building design and both of them are calculated in this real-time application. Therefore, it can be used for teachers to teach some part of physics about earth orbit and it can be used in building design and commercial games in virtual reality systems.

  12. An efficient approach for shadow detection based on Gaussian mixture model

    Institute of Scientific and Technical Information of China (English)

    韩延祥; 张志胜; 陈芳; 陈恺

    2014-01-01

    An efficient approach was proposed for discriminating shadows from moving objects. In the background subtraction stage, moving objects were extracted. Then, the initial classification for moving shadow pixels and foreground object pixels was performed by using color invariant features. In the shadow model learning stage, instead of a single Gaussian distribution, it was assumed that the density function computed on the values of chromaticity difference or bright difference, can be modeled as a mixture of Gaussian consisting of two density functions. Meanwhile, the Gaussian parameter estimation was performed by using EM algorithm. The estimates were used to obtain shadow mask according to two constraints. Finally, experiments were carried out. The visual experiment results confirm the effectiveness of proposed method. Quantitative results in terms of the shadow detection rate and the shadow discrimination rate (the maximum values are 85.79%and 97.56%, respectively) show that the proposed approach achieves a satisfying result with post-processing step.

  13. Shadow Economy in the Context of Economic Crisis: Circumstance Analysis and the Forecasting of Consequences

    Directory of Open Access Journals (Sweden)

    Alexey Sergeyevich Naidenov

    2013-03-01

    Full Text Available The article is devoted to the problem of estimating dynamic of shadow economy in the context of socio-economic crisis negative influence. Factors and threats supporting the increase of shadow economy during the economic crisis were studied. Current situation in the Ural Federal District with regard to shadow economic activity for the period from 2006 to 2012 was represented. The results of forecasting shadow activity were given in the article on the example of Ural Federal District regions. Data obtained was used for developing target program activities, aimed at minimization of negative influence of shadow economy during the economic crisis. Special attention was given to the problem of improving the effectiveness of international cooperation concerning counteraction of shadow economic activity

  14. Message communications of particular message types between compute nodes using DMA shadow buffers

    Science.gov (United States)

    Blocksome, Michael A.; Parker, Jeffrey J.

    2010-11-16

    Message communications of particular message types between compute nodes using DMA shadow buffers includes: receiving a buffer identifier specifying an application buffer having a message of a particular type for transmission to a target compute node through a network; selecting one of a plurality of shadow buffers for a DMA engine on the compute node for storing the message, each shadow buffer corresponding to a slot of an injection FIFO buffer maintained by the DMA engine; storing the message in the selected shadow buffer; creating a data descriptor for the message stored in the selected shadow buffer; injecting the data descriptor into the slot of the injection FIFO buffer corresponding to the selected shadow buffer; selecting the data descriptor from the injection FIFO buffer; and transmitting the message specified by the selected data descriptor through the data communications network to the target compute node.

  15. ANALYZING SPECTRAL CHARACTERISTICS OF SHADOW AREA FROM ADS-40 HIGH RADIOMETRIC RESOLUTION AERIAL IMAGES

    Directory of Open Access Journals (Sweden)

    Y.-T. Hsieh

    2016-06-01

    Full Text Available The shadows in optical remote sensing images are regarded as image nuisances in numerous applications. The classification and interpretation of shadow area in a remote sensing image are a challenge, because of the reduction or total loss of spectral information in those areas. In recent years, airborne multispectral aerial image devices have been developed 12-bit or higher radiometric resolution data, including Leica ADS-40, Intergraph DMC. The increased radiometric resolution of digital imagery provides more radiometric details of potential use in classification or interpretation of land cover of shadow areas. Therefore, the objectives of this study are to analyze the spectral properties of the land cover in the shadow areas by ADS-40 high radiometric resolution aerial images, and to investigate the spectral and vegetation index differences between the various shadow and non-shadow land covers. According to research findings of spectral analysis of ADS-40 image: (i The DN values in shadow area are much lower than in nonshadow area; (ii DN values received from shadowed areas that will also be affected by different land cover, and it shows the possibility of land cover property retrieval as in nonshadow area; (iii The DN values received from shadowed regions decrease in the visible band from short to long wavelengths due to scattering; (iv The shadow area NIR of vegetation category also shows a strong reflection; (v Generally, vegetation indexes (NDVI still have utility to classify the vegetation and non-vegetation in shadow area. The spectral data of high radiometric resolution images (ADS-40 is potential for the extract land cover information of shadow areas.

  16. Analyzing Spectral Characteristics of Shadow Area from ADS-40 High Radiometric Resolution Aerial Images

    Science.gov (United States)

    Hsieh, Yi-Ta; Wu, Shou-Tsung; Chen, Chaur-Tzuhn; Chen, Jan-Chang

    2016-06-01

    The shadows in optical remote sensing images are regarded as image nuisances in numerous applications. The classification and interpretation of shadow area in a remote sensing image are a challenge, because of the reduction or total loss of spectral information in those areas. In recent years, airborne multispectral aerial image devices have been developed 12-bit or higher radiometric resolution data, including Leica ADS-40, Intergraph DMC. The increased radiometric resolution of digital imagery provides more radiometric details of potential use in classification or interpretation of land cover of shadow areas. Therefore, the objectives of this study are to analyze the spectral properties of the land cover in the shadow areas by ADS-40 high radiometric resolution aerial images, and to investigate the spectral and vegetation index differences between the various shadow and non-shadow land covers. According to research findings of spectral analysis of ADS-40 image: (i) The DN values in shadow area are much lower than in nonshadow area; (ii) DN values received from shadowed areas that will also be affected by different land cover, and it shows the possibility of land cover property retrieval as in nonshadow area; (iii) The DN values received from shadowed regions decrease in the visible band from short to long wavelengths due to scattering; (iv) The shadow area NIR of vegetation category also shows a strong reflection; (v) Generally, vegetation indexes (NDVI) still have utility to classify the vegetation and non-vegetation in shadow area. The spectral data of high radiometric resolution images (ADS-40) is potential for the extract land cover information of shadow areas.

  17. Fiscal illusion and the shadow economy: Two sides of the same coin?

    OpenAIRE

    Buehn, Andreas; DELL'ANNO, Roberto; Schneider, Friedrich

    2013-01-01

    This paper presents an empirical analysis of the relationship between fiscal illusion and the shadow economy for 104 countries over the period 1989–2009. We argue that both unobservable phenomena are closely linked to each other, as the creation of a fiscal illusion may be helpful if governments want to control shadow economic activities. Using a MIMIC model with two latent variables we confirm previous findings on the driving forces of the shadow economy and identify the main determinants an...

  18. Shadow-based Building Detection and Segmentation in High-resolution Remote Sensing Image

    OpenAIRE

    Dongyue Chen; Shibo Shang; Chengdong Wu

    2014-01-01

    This paper proposes an effective method to extract buildings in high-resolution remote sensing images based on shadow detection. Firstly, a superpixel segmentation algorithm called SLIC is introduced to split the input image into homogeneous patches. LDA-based color features of the patches are extracted for detecting shadow regions. According to the positions of the shadows, an adaptive strategy for seed location and regional growth is developed to accomplish the coarse detection of buildings...

  19. Krüppel Expression Levels Are Maintained through Compensatory Evolution of Shadow Enhancers

    OpenAIRE

    Zeba Wunderlich; Meghan D.J. Bragdon; Ben J. Vincent; Jonathan A. White; Javier Estrada; Angela H. DePace

    2015-01-01

    Many developmental genes are controlled by shadow enhancers—pairs of enhancers that drive overlapping expression patterns. We hypothesized that compensatory evolution can maintain the total expression of a gene, while individual shadow enhancers diverge between species. To test this hypothesis, we analyzed expression driven by orthologous pairs of shadow enhancers from Drosophila melanogaster, Drosophila yakuba, and Drosophila pseudoobscura that control expression of Krüppel, a transcription ...

  20. Real-Time Volume Shadow using Visible-Non Visible Algorithm

    Directory of Open Access Journals (Sweden)

    Hoshang Kolivand

    2011-01-01

    Full Text Available Problem statement: Shadows are most important effect to make realistic games and visually appealing images, but they are poor in frame per second. Silhouette detection is most important phases to create real-time shadow. Approach: Present study describes a real-time shadow generated with volume shadow algorithm using Visible-Non Visible algorithm (VNV in virtual environment illuminated by a movable light source to improve the frame per second. Silhouette detection that is most expensive part of shadow creation was described. Triangular method and VNV method were compared. An improved algorithm for volume shadow was proposed and volume shadow using both methods in C+ Opengl implemented. Results: The VNV algorithm increases the number of Frame Per Second (FPS and as a result decreases the cost of implementation. Conclusion: A verified algorithm for volume shadow makes it easy to understand by everyone how to produce real-time shadow in outdoor and indoor virtual environment. It is possible to use it in current commercial games or other virtual reality systems.

  1. Study on the shadowing effect for optical wave scattering from randomly rough surface

    Institute of Scientific and Technical Information of China (English)

    Lixin Guo(郭立新); Yunhua Wang(王运华); Zhensen Wu(吴振森)

    2004-01-01

    Based on the Kirchhoff approximation for rough surface scattering and by calculating the shadowing function of the rough surface, the formula of the scattering cross section of the dielectric rough surface is presented with consideration of the shadowing effect for the optical wave incidence. It is obtained that in comparison with the conventional Kirchhoff solution, the shadowing effect should not be neglected for the optical wave scattering from the rough surface. The influence of the shadowing effect for different incidence angle, surface root mean square slope, and surface roughness on the scattering cross section is discussed in detail.

  2. Pixel-wise Orthogonal Decomposition for Color Illumination Invariant and Shadow-free Image

    OpenAIRE

    Qu, Liangqiong; Tian, Jiandong; Han, Zhi; Tang, Yandong

    2014-01-01

    In this paper, we propose a novel, effective and fast method to obtain a color illumination invariant and shadow-free image from a single outdoor image. Different from state-of-the-art methods for shadow-free image that either need shadow detection or statistical learning, we set up a linear equation set for each pixel value vector based on physically-based shadow invariants, deduce a pixel-wise orthogonal decomposition for its solutions, and then get an illumination invariant vector for each...

  3. Global patterns of amphibian phylogenetic diversity

    DEFF Research Database (Denmark)

    Fritz, Susanne; Rahbek, Carsten

    2012-01-01

    phylogeny (2792 species). We combined each tree with global species distributions to map four indices of phylogenetic diversity. To investigate congruence between global spatial patterns of amphibian species richness and phylogenetic diversity, we selected Faith’s phylogenetic diversity (PD) index...... successfully colonized these archipelagos. Areas with unusually high phylogenetic diversity were located around biogeographic contact zones in Central America and southern China, and seem to have experienced high immigration or in situ diversification rates, combined with local persistence of old lineages...

  4. Phyx: phylogenetic tools for unix.

    Science.gov (United States)

    Brown, Joseph W; Walker, Joseph F; Smith, Stephen A

    2017-02-08

    The ease with which phylogenomic data can be generated has drastically escalated the computational burden for even routine phylogenetic investigations. To address this, we present phyx : a collection of programs written in C ++ to explore, manipulate, analyze and simulate phylogenetic objects (alignments, trees and MCMC logs). Modelled after Unix/GNU/Linux command line tools, individual programs perform a single task and operate on standard I/O streams that can be piped to quickly and easily form complex analytical pipelines. Because of the stream-centric paradigm, memory requirements are minimized (often only a single tree or sequence in memory at any instance), and hence phyx is capable of efficiently processing very large datasets. phyx runs on POSIX-compliant operating systems. Source code, installation instructions, documentation and example files are freely available under the GNU General Public License at https://github.com/FePhyFoFum/phyx. eebsmith@umich.edu. Supplementary data are available at Bioinformatics online.

  5. Low Frequency Shadowing of the Parkes Superb Survey

    Science.gov (United States)

    Bhat, N. D. R.; Kaplan, D. L.; Williams, A.; Wayth, R.

    2017-01-01

    The field of Fast Radio Bursts (FRBs) is rapidly gaining momentum. Since their discovery in the Parkes high time resolution survey (Thornton et al. 2013), the number of reported FRB detections has more than tripled, and measurements have been made of their scattering, scintillation, polarisation and Faraday rotation properties, all of which helped to establish their astrophysical nature. Obser- vational evidence continues to mount in support of their extragalactic origin, and the world-wide competitive race is ramping up as a suite of new and existing instruments are gearing up to find them in large numbers. The SUPERB survey at Parkes has been conceived to realise the important goal of understanding the origin and progenitors of FRBs. An integral part of this survey is co-ordinated multi-wavelength follow-ups and shadowing. Our MWA-based shadowing efforts last year resulted in the first simultaneous multi-frequency observation of an FRB (albeit a non-detection at the MWA), and hence the first broadband limit on the spectral index, as reported in our Nature publication (Keane at al. 2016). After an year-long hiatus the SUPERB survey is scheduled to resume in December 2016. We propose to resume our MWA-based efforts by undertaking effective low-frequency shadowing that is uniquely possible with the MWA. Simultaneous detection of even a single a self-same FRB would bring in a huge science payoff and will yield the first unambiguous constraints on the spectral and scattering properties of FRBs, besides the prospects of sub-arc minute localisation that will be possible with the long baseline array of Phase 2 MWA. We propose to make use of unallocated blocks of time within the schedule, available outside the approved programs and the planned commissioning activities relating to Phase 2. This proposal will thus make excellent use of idle time for an exciting and very important science goal in the nascent field of FRB science.

  6. Robust Lane Sensing and Departure Warning under Shadows and Occlusions

    Directory of Open Access Journals (Sweden)

    Miguel Torres-Torriti

    2013-03-01

    Full Text Available A prerequisite for any system that enhances drivers’ awareness of road conditions and threatening situations is the correct sensing of the road geometry and the vehicle’s relative pose with respect to the lane despite shadows and occlusions. In this paper we propose an approach for lane segmentation and tracking that is robust to varying shadows and occlusions. The approach involves color-based clustering, the use of MSAC for outlier removal and curvature estimation, and also the tracking of lane boundaries. Lane boundaries are modeled as planar curves residing in 3D-space using an inverse perspective mapping, instead of the traditional tracking of lanes in the image space, i.e., the segmented lane boundary points are 3D points in a coordinate frame fixed to the vehicle that have a depth component and belong to a plane tangent to the vehicle’s wheels, rather than 2D points in the image space without depth information. The measurement noise and disturbances due to vehicle vibrations are reduced using an extended Kalman filter that involves a 6-DOF motion model for the vehicle, as well as measurements about the road’s banking and slope angles. Additional contributions of the paper include: (i the comparison of textural features obtained from a bank of Gabor filters and from a GMRF model; and (ii the experimental validation of the quadratic and cubic approximations to the clothoid model for the lane boundaries. The results show that the proposed approach performs better than the traditional gradient-based approach under different levels of difficulty caused by shadows and occlusions.

  7. An Improved Shadow Maps Algorithm for Real-time Rendering%基于Shadow Maps的实时阴影生成算法改进

    Institute of Scientific and Technical Information of China (English)

    张伟; 奚俊峰

    2011-01-01

    To build vivider shadows for real-time rendering in three-dimensional animation, Shadow Maps algorithm is studied and improved. By taking main value of average segmentation and logarithmic segmentation as the parameter to divide the shadow scene, the perspective aliasing is relieved. And by building and buffing the shadow maps twice with proper offset, the shadow acne, which caused by self-shadow error, is cleared up. The improved algorithm is implemented based on OpenGL with common graphic hardware and Windows XP. It's shown that the algorithm can build high quality shadows with satisfying the demand of the real-time rendering.%为了在三维动画场景中实时生成更逼真的阴影,分析了Shadow Maps 阴影生成算法走样和失真问题的原因.采用平均分割与对数分割相结合的方法改进了透视走样同题,采用双阴影图法改进了自阴影绘制问题.在Windows XP环境中,基于OpenGL库,编程实现了Shadow Maps算法改进.实验表明,在目前流行的硬件配置环境下,改进后的算法在阴影生成过程中能满足实时渲染帧率要求,同时增强虚拟场景阴影质量.

  8. Vestige: Maximum likelihood phylogenetic footprinting

    Directory of Open Access Journals (Sweden)

    Maxwell Peter

    2005-05-01

    Full Text Available Abstract Background Phylogenetic footprinting is the identification of functional regions of DNA by their evolutionary conservation. This is achieved by comparing orthologous regions from multiple species and identifying the DNA regions that have diverged less than neutral DNA. Vestige is a phylogenetic footprinting package built on the PyEvolve toolkit that uses probabilistic molecular evolutionary modelling to represent aspects of sequence evolution, including the conventional divergence measure employed by other footprinting approaches. In addition to measuring the divergence, Vestige allows the expansion of the definition of a phylogenetic footprint to include variation in the distribution of any molecular evolutionary processes. This is achieved by displaying the distribution of model parameters that represent partitions of molecular evolutionary substitutions. Examination of the spatial incidence of these effects across regions of the genome can identify DNA segments that differ in the nature of the evolutionary process. Results Vestige was applied to a reference dataset of the SCL locus from four species and provided clear identification of the known conserved regions in this dataset. To demonstrate the flexibility to use diverse models of molecular evolution and dissect the nature of the evolutionary process Vestige was used to footprint the Ka/Ks ratio in primate BRCA1 with a codon model of evolution. Two regions of putative adaptive evolution were identified illustrating the ability of Vestige to represent the spatial distribution of distinct molecular evolutionary processes. Conclusion Vestige provides a flexible, open platform for phylogenetic footprinting. Underpinned by the PyEvolve toolkit, Vestige provides a framework for visualising the signatures of evolutionary processes across the genome of numerous organisms simultaneously. By exploiting the maximum-likelihood statistical framework, the complex interplay between mutational

  9. China Folk Shadow Play Performing Group in Austria and Germany

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    <正>Sent by the CPAFFC,the Daoqing Shadow Play Performing Group(alias Shi Family Troupe) of Huanxian County,Gansu Province made a performance tour in Austria and Germany from October 22 to November 5,2007,during which it attended the International Puppet Theatre Festival in Mistelbach of Austria and gave performance at the opening ceremony of the International Puppet Art Festival in Bad Kreuznach of Germany.The performance tour was made at the invitation of the Austrian Association for Promotion of Friendship and Cultural Relations with China(AAPFCRC).

  10. When a giant falls, dwarfs have no shadow

    OpenAIRE

    2011-01-01

    It is said that in times of war old people bury young men. As we live in times of peace, and we are old, youngsters will need to bury us. It is said that we become good people after we die. But some of us were good before dying. They were good, generous and honored, wise and tender, effectively human. Some who passed away used to give us a cozy and protective shadow, and their absence leaves us unsheltered, alone with danger. A long time ago, one of our children asked to us: “When an old wise...

  11. Nuclear Shadowing and Select d+Au Observables

    Science.gov (United States)

    Adeluyi, Adeola; Fai, George

    2007-04-01

    Much of the complexity of the description of d+Au collisions in the framework of perturbative Quantum Chromodynamics (pQCD) derives from effects of the nuclear environment. Here we investigate the effects of the most recent available nuclear shadowing parametrization, the Hirai-Kumano-Nagai (HKN) nuclear parton distribution functions (nPDFs) and the updated Albino-Kniehl-Kramer (AKK) fragmentation functions on three select d+Au collision observables. We compare our results to available experimental data from the STAR and BRAHMS collaborations.

  12. In the shadow of the cell-phone

    DEFF Research Database (Denmark)

    Hansen, Lone Koefoed

    2009-01-01

    Based on discussions of hybrid space as well as the concepts of the database and archive art, the paper analyzes Hasan Elahi’s project “Tracking Transience” (2003-) and relates it to Sophie Calle’s performance “Detective” (1980) while discussing how we can understand the mobile phone as a device ...... to an enormous amount of data, we are left with a feeling of following a shadow or maybe a mirage. This paper explores how the mobile phone affords this playing hide-and-seek, and the way that it provides shelter from the inspecting eye...

  13. Asymptotic Ergodic Capacity Analysis of Composite Lognormal Shadowed Channels

    KAUST Repository

    Ansari, Imran Shafique

    2015-05-01

    Capacity analysis of composite lognormal (LN) shadowed links, such as Rician-LN, Gamma-LN, and Weibull-LN, is addressed in this work. More specifically, an exact closed-form expression for the moments of the end-to-end signal-to-noise ratio (SNR) of a single composite link transmission system is presented in terms of well- known elementary functions. Capitalizing on these new moments expressions, we present asymptotically tight lower bounds for the ergodic capacity at high SNR. All the presented results are verified via computer-based Monte-Carlo simulations. © 2015 IEEE.

  14. Phylogenetic analysis of otospiralin protein

    Science.gov (United States)

    Torktaz, Ibrahim; Behjati, Mohaddeseh; Rostami, Amin

    2016-01-01

    Background: Fibrocyte-specific protein, otospiralin, is a small protein, widely expressed in the central nervous system as neuronal cell bodies and glia. The increased expression of otospiralin in reactive astrocytes implicates its role in signaling pathways and reparative mechanisms subsequent to injury. Indeed, otospiralin is considered to be essential for the survival of fibrocytes of the mesenchymal nonsensory regions of the cochlea. It seems that other functions of this protein are not yet completely understood. Materials and Methods: Amino acid sequences of otospiralin from 12 vertebrates were derived from National Center for Biotechnology Information database. Phylogenetic analysis and phylogeny estimation were performed using MEGA 5.0.5 program, and neighbor-joining tree was constructed by this software. Results: In this computational study, the phylogenetic tree of otospiralin has been investigated. Therefore, dendrograms of otospiralin were depicted. Alignment performed in MUSCLE method by UPGMB algorithm. Also, entropy plot determined for a better illustration of amino acid variations in this protein. Conclusion: In the present study, we used otospiralin sequence of 12 different species and by constructing phylogenetic tree, we suggested out group for some related species. PMID:27099854

  15. Shadow detection improvement using spectral indices and morphological operators in high resolution images from urban areas

    Science.gov (United States)

    Azevedo, S. C.; Silva, E. A.; Pedrosa, M. M.

    2015-04-01

    While high-resolution remote sensing images have increased application possibilities for urban studies, the large number of shadow areas has created challenges to processing and extracting information from these images. Furthermore, shadows can reduce or omit information from the surface as well as degrading the visual quality of images. The pixels of shadows tend to have lower radiance response within the spectrum and are often confused with low reflectance targets. In this work, a shadow detection method was proposed using a morphological operator for dark pattern identification combined with spectral indices. The aims are to avoid misclassification in shadow identification through properties provided by them on color models and, therefore, to improve shadow detection accuracy. Experimental results were tested applying the panchromatic and multispectral band of WorldView-2 image from Sao Paulo city in Brazil, which is a complex urban environment composed by high objects like tall buildings causing large shadow areas. Black top-hat with area injunction was applied in PAN image and shadow identification performance has improved with index as Normalized Difference Vegetation Index (NDVI) and Normalized Saturation-Value Difference Index (NSDVI) ratio from HSV color space obtained from pansharpened multispectral WV-2 image. An increase in distinction between shadows and others objects was observed, which was tested for the completeness, correctness and quality measures computed, using a created manual shadow mask as reference. Therefore, this method can contribute to overcoming difficulties faced by other techniques that need shadow detection as a first necessary preprocessing step, like object recognition, image matching, 3D reconstruction, etc.

  16. Racing the Moon’s shadow with Concorde 001

    CERN Document Server

    Léna, Pierre

    2015-01-01

    This is the unique story of  observing a total solar exlipse for no less than 74 consecutive minutes. On the summer morning of June 30, 1973, the Sun rises on the Canary Islands. But it is strangely indented by the Moon. The eclipse of the century has just begun. From the west, the lunar shadow rushes to the African coast at a velocity of over 2000 kilometers per hour. Astronomers on the ground will enjoy seven short minutes of total eclipse to study the solar corona - too short for Pierre Lena and seven scientists who board the Concorde 001 prototype, an extraordinary plane to become the first commercial supersonic aircraft. With André Turcat as chief pilot and a crew of five, at 17000 m altitude, the aircraft remains in the lunar shadow for 74 minutes, a record time of scientific observations not yet beaten and allowing for exceptional measurements. Science, technology, aviation and history combine in the story of a unique human adventure aboard a legendary aircraft, illustrated with a rich and original ...

  17. Are passive protostellar disks stable to self-shadowing?

    CERN Document Server

    Dullemond, C P

    2000-01-01

    The uniqueness and stability of irradiated flaring passive protostellar disks is investigated in the context of a simplified set of equations for the vertical height H as a function of radius R. It is found that the well-known flaring disk solution with H ~ R^{9/7} is not unique. Diverging solutions and asymptotically conical (H ~ R) solutions are also found. Moreover, using time-dependent linear perturbation analysis, it is found that the flaring disk solution may become unstable to self-shadowing. A local enhancement in the vertical height alters the functional form of irradiation grazing angle, and causes the 'sunny side' of the enhancement to grow and the 'shadow side' to collapse in a run-away fashion. This instability operates in regions of the disk in which the cooling time is much shorter than the vertical sound crossing time, which may occur in the outer regions of the passive irradiated disk if dust and gas are sufficiently strongly thermally coupled. Processes that may stabilize the disk, which inc...

  18. Tomographic Particle Image Velocimetry using Smartphones and Colored Shadows

    KAUST Repository

    Aguirre-Pablo, Andres A.

    2017-06-12

    We demonstrate the viability of using four low-cost smartphone cameras to perform Tomographic PIV. We use colored shadows to imprint two or three different time-steps on the same image. The back-lighting is accomplished with three sets of differently-colored pulsed LEDs. Each set of Red, Green & Blue LEDs is shone on a diffuser screen facing each of the cameras. We thereby record the RGB-colored shadows of opaque suspended particles, rather than the conventionally used scattered light. We subsequently separate the RGB color channels, to represent the separate times, with preprocessing to minimize noise and cross-talk. We use commercially available Tomo-PIV software for the calibration, 3-D particle reconstruction and particle-field correlations, to obtain all three velocity components in a volume. Acceleration estimations can be done thanks to the triple pulse illumination. Our test flow is a vortex ring produced by forcing flow through a circular orifice, using a flexible membrane, which is driven by a pressurized air pulse. Our system is compared to a commercial stereoscopic PIV system for error estimations. We believe this proof of concept experiment will make this technique available for education, industry and scientists for a fraction of the hardware cost needed for traditional Tomo-PIV.

  19. Tomographic Particle Image Velocimetry Using Colored Shadow Imaging

    KAUST Repository

    Alarfaj, Meshal K.

    2016-02-01

    Tomographic Particle Image Velocimetry Using Colored Shadow Imaging by Meshal K Alarfaj, Master of Science King Abdullah University of Science & Technology, 2015 Tomographic Particle image velocimetry (PIV) is a recent PIV method capable of reconstructing the full 3D velocity field of complex flows, within a 3-D volume. For nearly the last decade, it has become the most powerful tool for study of turbulent velocity fields and promises great advancements in the study of fluid mechanics. Among the early published studies, a good number of researches have suggested enhancements and optimizations of different aspects of this technique to improve the effectiveness. One major aspect, which is the core of the present work, is related to reducing the cost of the Tomographic PIV setup. In this thesis, we attempt to reduce this cost by using an experimental setup exploiting 4 commercial digital still cameras in combination with low-cost Light emitting diodes (LEDs). We use two different colors to distinguish the two light pulses. By using colored shadows with red and green LEDs, we can identify the particle locations within the measurement volume, at the two different times, thereby allowing calculation of the velocities. The present work tests this technique on the flows patterns of a jet ejected from a tube in a water tank. Results from the images processing are presented and challenges discussed.

  20. Motion detection in color image sequence and shadow elimination

    Science.gov (United States)

    Shen, Jun

    2004-01-01

    Most of the researches are concentrated on motion detection in gray value image sequences and the methods for motion detection are based on background subtraction or on temporal gray value derivatives. The methods based on background subtraction, including auto-adaptive ones, meet difficulties in presence of illumination changes and of slowly moving objects and need to be re-initialized from time to time. The methods based on temporal derivatives are in general sensible to noise. Color images containing much richer information than the gray value ones, it would be interesting to use them to better detect moving objects. In this paper, we address the problem of motion detection in color image sequences and the problems of illumination changes and shadow elimination. Our motion detection method is based on fuzzy segmentation of the color difference image in help of non-symmetrical π membership functions. The elimination of false moving objects detected due to illumination change is realized by combining the background subtraction method with the temporal derivative method and motion continuity. Shadows are removed by comparing the color of mobile pixels detected in the current frame with that in the precedent frame in HSL color space. Experimental results are reported.

  1. Restricted numerical shadow and geometry of quantum entanglement

    CERN Document Server

    Puchała, Zbigniew; Gawron, Piotr; Dunkl, Charles F; Holbrook, John A; Życzkowski, Karol

    2012-01-01

    The restricted numerical range W_R(A) of an operator A acting on a D-dimensional Hilbert space is defined as a set of all possible expectation values of this operator among pure states which belong to a certain subset R of the of set of pure quantum states of dimension D. One considers for instance the set of real states, or in the case of composite spaces, the set of product states and the set of maximally entangled states. Combining the operator theory with a probabilistic approach we introduce the restricted numerical shadow of A -- a normalized probability distribution on the complex plane supported in W_R(A). Its value at point z in C is equal to the probability that the expectation value is equal to z, where |\\psi> represents a random quantum state in subset R distributed according to the natural measure on this set, induced by the unitarily invariant Fubini--Study measure. Studying restricted shadows of operators of a fixed size D=N_A N_B we analyse the geometry of sets of separable and maximally enta...

  2. Photon Regions and Shadows of Accelerated Black Holes

    CERN Document Server

    Grenzebach, Arne; Lämmerzahl, Claus

    2015-01-01

    In an earlier paper we have analytically determined the photon regions and the shadows of black holes of the Pleba\\'nski class of metrics which are also known as the Kerr-Newman-NUT-(anti-)deSitter metrics. The space-times described by these metrics are characterized by six independent parameters: mass, spin, electric and magnetic charge, gravitomagnetic NUT charge, and the cosmological constant. Here we extend this analysis to the Pleba\\'nski-Demia\\'nski class of metrics which contains, in addition to these six parameters, the so-called acceleration parameter. All these metrics are axially symmetric and stationary solutions to the Einstein-Maxwell equations with a cosmological constant which are of Petrov type D. We derive analytical formulas for the photon regions (i.e., for the regions that contain spherical lightlike geodesics) and for the boundary curve of the shadow as it is seen by an observer at Boyer-Lindquist coordinates $(r_O, \\vartheta _O)$ in the domain of outer communication. Whereas all relevan...

  3. Shadows and spirals in the protoplanetary disk HD 100453

    CERN Document Server

    Benisty, M; Pohl, A; de Boer, J; Lesur, G; Dominik, C; Dullemond, C P; Langlois, M; Min, M; Wagner, K; Henning, T; Juhasz, A; Pinilla, P; Apai, D; van Boekel, R; Garufi, A; Ginski, C; Ménard, F; Pinte, C; Quanz, S P; Zurlo, A; Boccaletti, A; Bonnefoy, M; Beuzit, J L; Chauvin, G; Cudel, M; Desidera, S; Feldt, M; Fontanive, C; Gratton, R; Kasper, M; Lagrange, A -M; LeCoroller, H; Mouillet, D; Mesa, D; Sissa, E; Vigan, A; Antichi, J; Buey, T; Fusco, T; Gisler, D; Llored, M; Magnard, Y; Moeller-Nilsson, O; Pragt, J; Roelfsema, R; Sauvage, J -F; Wildi, F

    2016-01-01

    Understanding the diversity of planets requires to study the morphology and the physical conditions in the protoplanetary disks in which they form. We observed and spatially resolved the disk around the ~10 Myr old protoplanetary disk HD 100453 in polarized scattered light with SPHERE/VLT at optical and near-infrared wavelengths, reaching an angular resolution of ~0.02", and an inner working angle of ~0.09". We detect polarized scattered light up to ~0.42" (~48 au) and detect a cavity, a rim with azimuthal brightness variations and inclined by 38 degrees, two shadows and two symmetric spiral arms. The spiral arms originate near the location of the shadows, close to the semi major axis. We detect a faint spiral-like feature in the SW that can be interpreted as the scattering surface of the bottom side of the disk, if the disk is tidally truncated by the M-dwarf companion currently seen at a projected distance of ~119 au. We construct a radiative transfer model that accounts for the main characteristics of the ...

  4. The sculpting of Jupiter's gossamer rings by its shadow.

    Science.gov (United States)

    Hamilton, Douglas P; Krüger, Harald

    2008-05-01

    Dust near Jupiter is produced when interplanetary impactors collide energetically with small inner moons, and is organized into a main ring, an inner halo, and two fainter and more distant gossamer rings. Most of these structures are constrained by the orbits of the moons Adrastea, Metis, Amalthea and Thebe, but a faint outward protrusion called the Thebe extension behaves differently and has eluded understanding. Here we report on dust impacts detected during the Galileo spacecraft's traversal of the outer ring region: we find a gap in the rings interior to Thebe's orbit, grains on highly inclined paths, and a strong excess of submicrometre-sized dust just inside Amalthea's orbit. We present detailed modelling that shows that the passage of ring particles through Jupiter's shadow creates the Thebe extension and fully accounts for these Galileo results. Dust grains alternately charge and discharge when traversing shadow boundaries, allowing the planet's powerful magnetic field to excite orbital eccentricities and, when conditions are right, inclinations as well.

  5. Explaining UXOR variability with self-shadowed disks

    CERN Document Server

    Dullemond, C P; Acke, B; Van Boekel, R

    2003-01-01

    In this Letter we propose a new view on UX Orionis type variability. The idea is based on the earlier proposal by various authors that UXORs are nearly-edge-on disks in which hydrodynamic fluctuations could cause clumps of dust and gas to cross the line of sight. However, because the standard disk models have a flaring geometry, it is mostly the outer regions of the disk that obscure the star. The time scales for such obscuration events would be too long to match the observed time scales of weeks to months. Recent 2-D self-consistent models of Herbig Ae/Be protoplanetary disks (Dullemond et al. 2002,2003 henceforth D02/DD03), however, have indicated that for Herbig Ae/Be star disks there exists, in addition to the usual flared disks, also a new class of disks: those that are fully self-shadowed. Only their puffed-up inner rim (at the dust evaporation radius) is directly irradiated by the star, while the disk at larger radius resides in the shadow of the rim. For these disks there exist inclinations at which t...

  6. Implicit encoding of extrinsic object properties in stored representations mediating recognition: evidence from shadow-specific repetition priming.

    Science.gov (United States)

    Leek, E Charles; Davitt, Lina I; Cristino, Filipe

    2015-03-01

    This study investigated whether, and under what conditions, stored shape representations mediating recognition encode extrinsic object properties that vary according to viewing conditions. This was examined in relation to cast shadow. Observers (N = 90) first memorised a subset of 3D multi-part novel objects from a limited range of viewpoints rendered with either no shadow, object internal shadow, or both object internal and external (ground) plane shadow. During a subsequent test phase previously memorised targets were discriminated from visually similar distractors across learned and novel views following brief presentation of a same-shape masked prime. The primes contained either matching or mismatching shadow rendering from the training condition. The results showed a recognition advantage for objects memorised with object internal shadow. In addition, objects encoded with internal shadow were primed more strongly by matching internal shadow primes, than by same shape primes with either no shadow or both object internal and external (ground) shadow. This pattern of priming effects generalises to previously unseen views of targets rendered with object internal shadow. The results suggest that the object recognition system contains a level of stored representation at which shape and the extrinsic object property of cast shadow are bound. We propose that this occurs when cast shadow cannot be discounted during perception on the basis of external cues to the scene lighting model.

  7. Comparison of tree-child phylogenetic networks.

    Science.gov (United States)

    Cardona, Gabriel; Rosselló, Francesc; Valiente, Gabriel

    2009-01-01

    Phylogenetic networks are a generalization of phylogenetic trees that allow for the representation of nontreelike evolutionary events, like recombination, hybridization, or lateral gene transfer. While much progress has been made to find practical algorithms for reconstructing a phylogenetic network from a set of sequences, all attempts to endorse a class of phylogenetic networks (strictly extending the class of phylogenetic trees) with a well-founded distance measure have, to the best of our knowledge and with the only exception of the bipartition distance on regular networks, failed so far. In this paper, we present and study a new meaningful class of phylogenetic networks, called tree-child phylogenetic networks, and we provide an injective representation of these networks as multisets of vectors of natural numbers, their path multiplicity vectors. We then use this representation to define a distance on this class that extends the well-known Robinson-Foulds distance for phylogenetic trees and to give an alignment method for pairs of networks in this class. Simple polynomial algorithms for reconstructing a tree-child phylogenetic network from its path multiplicity vectors, for computing the distance between two tree-child phylogenetic networks and for aligning a pair of tree-child phylogenetic networks, are provided. They have been implemented as a Perl package and a Java applet, which can be found at http://bioinfo.uib.es/~recerca/phylonetworks/mudistance/.

  8. Functional and phylogenetic ecology in R

    CERN Document Server

    Swenson, Nathan G

    2014-01-01

    Functional and Phylogenetic Ecology in R is designed to teach readers to use R for phylogenetic and functional trait analyses. Over the past decade, a dizzying array of tools and methods were generated to incorporate phylogenetic and functional information into traditional ecological analyses. Increasingly these tools are implemented in R, thus greatly expanding their impact. Researchers getting started in R can use this volume as a step-by-step entryway into phylogenetic and functional analyses for ecology in R. More advanced users will be able to use this volume as a quick reference to understand particular analyses. The volume begins with an introduction to the R environment and handling relevant data in R. Chapters then cover phylogenetic and functional metrics of biodiversity; null modeling and randomizations for phylogenetic and functional trait analyses; integrating phylogenetic and functional trait information; and interfacing the R environment with a popular C-based program. This book presents a uni...

  9. Implementing content constraints in alpha-stratified adaptive using a shadow test approach

    NARCIS (Netherlands)

    Linden, van der Wim J.; Chang, Hua-Hua

    2003-01-01

    The methods of alpha-stratified adaptive testing and constrained adaptive testing with shadow tests are combined. The advantages are twofold: First, application of the shadow test approach allows the implementation of any type of constraint on item selection in alpha-stratified adaptive testing. Sec

  10. Implementing Content Constraints in Alpha-Stratified Adaptive Testing Using a Shadow Test Approach. Research Report.

    Science.gov (United States)

    van der Linden, Wim J.; Chang, Hua-Hua

    The methods of alpha-stratified adaptive testing and constrained adaptive testing with shadow tests are combined in this study. The advantages are twofold. First, application of the shadow test allows the researcher to implement any type of constraint on item selection in alpha-stratified adaptive testing. Second, the result yields a simple set of…

  11. On the MIMO Capacity for Distributed System under Composite Rayleigh/Rician Fading and Shadowing

    Directory of Open Access Journals (Sweden)

    Santiago González-Aurioles

    2015-01-01

    Full Text Available Wireless channels are commonly affected by short-term fading and long-term fading (shadowing. The shadowing effects must be taken into account also when mobility is present in the wireless scenario. Using a composite fading model, the total channel capacity can be studied for a scenario with short-term Rayleigh fading along with shadowing. This work provides quantitative results for these kinds of scenarios with Rayleigh fading and shadowing, considering also multiple-input and multiple-output systems, which have not been previously reported. In addition, the channel capacity has been studied in depth in its relation with the shadowing level, signal to noise ratio, and the number of elements in the multiple-input and multiple-output system. Moreover, the channel performance with shadowing has been compared to the one without it. Furthermore, Rician model with shadowing is studied and its results are reported. In addition, correlated and experimental results are provided. It is identified that the distributed MIMO systems can benefit from shadowing in Rician channels. This advantage has not been reported previously. This type of fading is proposed for massive MIMO by others and our results open the door to emulate massive MIMO on a reverberation chamber.

  12. Qualitative Shadowing as a Research Methodology for Exploring Early Childhood Leadership in Practice

    Science.gov (United States)

    Bøe, Marit; Hognestad, Karin; Waniganayake, Manjula

    2017-01-01

    This article explores qualitative shadowing as an interpretivist methodology, and explains how two researchers participating simultaneously in data collection using a video recorder, contextual interviews and video-stimulated recall interviews, conducted a qualitative shadowing study at six early childhood centres in Norway. This paper emerged…

  13. Discursive Shadowing in Linguistic Ethnography. Situated Practices and Circulating Discourses in Multilingual Schools

    Science.gov (United States)

    Dewilde, Joke; Creese, Angela

    2016-01-01

    We consider discursive shadowing as methodology in linguistic ethnography and how it refines our analyses of participants' situated practices. In addition to the constant and extended company the researcher and key participant keep with one another in the field, shadowing in a linguistic ethnographic approach includes the ubiquitous…

  14. Performance analysis of a modified moving shadow elimination method developed for indoor scene activity tracking

    Science.gov (United States)

    Mitra, Bhargav Kumar; Fiaz, Muhammad Kamran; Kypraios, Ioannis; Birch, Philip; Young, Rupert; Chatwin, Chris

    2008-10-01

    Moving shadow detection is an important step in automated robust surveillance systems in which a dynamic object is to be segmented and tracked. Rejection of the shadow region significantly reduces the erroneous tracking of non-target objects within the scene. A method to eliminate such shadows in indoor video sequences has been developed by the authors. The objective has been met through the use of a pixel-wise shadow search process that utilizes a computational model in the RGB colour space to demarcate the moving shadow regions from the background scene and the foreground objects. However, it has been observed that the robustness and efficiency of the method can be significantly enhanced through the deployment of a binary-mask based shadow search process. This, in turn, calls for the use of a prior foreground object segmentation technique. The authors have also automated a standard foreground object segmentation technique through the deployment of some popular statistical outlier-detection based strategies. The paper analyses the performance i.e. the effectiveness as a shadow detector, discrimination potential, and the processing time of the modified moving shadow elimination method on the basis of some standard evaluation metrics.

  15. The Job Shadow Assignment: Career Perceptions in Hospitality, Recreation and Tourism

    Science.gov (United States)

    Padron, Thomas C.; Fortune, Mary F.; Spielman, Melany; Tjoei, Sylvie

    2017-01-01

    The job shadow study measured student career perceptions related to hospitality, recreation and tourism (HRT) and instructional mode (face-to-face (F2F), hybrid, and online). College students self-selecting into three different course modalities taught by the same instructor job shadowed HRT professionals by using Internet and F2F interviews. The…

  16. The effect of shadow lines on a low concentrating photovoltaic system

    NARCIS (Netherlands)

    Janssen, H.J.J.; Sonneveld, P.J.; Swinkels, G.L.A.M.; Tuijl, van B.A.J.; Zwart, de H.F.

    2011-01-01

    In order to reduce the energy losses caused by shadow lines, three options are investigated. These are: 1. the use of two types of diodes; 2. the use of an ”ideal” diode based an active bypass by using MOS-FET’s [4] and 3. parallel switching of a number of cells between two shadow lines. The first

  17. Presence of Gumprecht shadows (smudge cells) in bovine leukemia virus-positive cattle.

    Science.gov (United States)

    Panei, Carlos Javier; Larsen, Alejandra; González, Ester Teresa; Echeverría, María Gabriela

    2013-11-01

    Enzootic Bovine Leukosis is a chronic disease caused by the bovine leukemia virus (BLV). Smudge cells, also known as Gumprecht shadows, are not simple artifacts of slide preparation, but ragged lymphoid cells found mainly in peripheral blood smears from human patients with chronic lymphocytic leukemia. In this study, we report the presence of Gumprecht shadows in peripheral blood from BLV-positive cattle.

  18. Automatic aerial image shadow detection through the hybrid analysis of RGB and HIS color space

    Science.gov (United States)

    Wu, Jun; Li, Huilin; Peng, Zhiyong

    2015-12-01

    This paper presents our research on automatic shadow detection from high-resolution aerial image through the hybrid analysis of RGB and HIS color space. To this end, the spectral characteristics of shadow are firstly discussed and three kinds of spectral components including the difference between normalized blue and normalized red component - BR, intensity and saturation components are selected as criterions to obtain initial segmentation of shadow region (called primary segmentation). After that, within the normalized RGB color space and HIS color space, the shadow region is extracted again (called auxiliary segmentation) using the OTSU operation, respectively. Finally, the primary segmentation and auxiliary segmentation are combined through a logical AND-connection operation to obtain reliable shadow region. In this step, small shadow areas are removed from combined shadow region and morphological algorithms are apply to fill small holes as well. The experimental results show that the proposed approach can effectively detect the shadow region from high-resolution aerial image and in high degree of automaton.

  19. Phylogenetic trees and Euclidean embeddings.

    Science.gov (United States)

    Layer, Mark; Rhodes, John A

    2017-01-01

    It was recently observed by de Vienne et al. (Syst Biol 60(6):826-832, 2011) that a simple square root transformation of distances between taxa on a phylogenetic tree allowed for an embedding of the taxa into Euclidean space. While the justification for this was based on a diffusion model of continuous character evolution along the tree, here we give a direct and elementary explanation for it that provides substantial additional insight. We use this embedding to reinterpret the differences between the NJ and BIONJ tree building algorithms, providing one illustration of how this embedding reflects tree structures in data.

  20. Education under the shadow in Southern European countries. Implications for equity

    Directory of Open Access Journals (Sweden)

    Ariadne Runte-Geidel

    2015-06-01

    Full Text Available Nowadays most educational research focuses on formal education. However it is gradually recognizing the existence of a parallel education system that accompanies the formal system as if was its own shadow. The shadow education is a system based on the laws of the market, still poorly regulated and under-researched. This comparative study aims to determine the prevalence of shadow education in Spain and countries in its geographical and cultural context, also examine their implications in the different countries studied. Analyzes carried out show high rates of use of shadow education in all countries studied and similarities in the effects on social equity. The findings point to the need for regulation of the sector and infer about problems in formal systems as the possible cause of the high rates of shadow education are found.

  1. Double shadow of a regular phantom black hole as photons couple to Weyl tensor

    CERN Document Server

    Huang, Yang; Jing, Jiliang

    2016-01-01

    We have studied the shadow of a regular phantom black hole as photons couple to Weyl tensor. We find that the coupling yields that photons with different polarization directions propagate along different paths in the spacetime so that there exits double shadow for a black hole, which is quite different from that in the non-coupling case where only a single shadow emerges. The umbra of black hole increases with the phantom charge and decreases with the coupling strength. The dependence of the penumbra on the phantom charge and the coupling strength is converse to that of the umbra. Combining with the supermassive central object in our Galaxy, we estimated the shadow of the black hole as the photons couple to Weyl tensor. Our results show that the coupling brings richer behaviors of the propagation of coupled photon and the shadow of the black hole in the regular phantom black hole spacetime.

  2. Shadow Probability of Detection and False Alarm for Median-Filtered SAR Imagery

    Energy Technology Data Exchange (ETDEWEB)

    Raynal, Ann Marie [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States). ISR Analysis and Applications Dept.; Doerry, Armin Walter [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States). ISR Mission Engineering Dept.; Miller, John A. [General Atomics Aeronautical Systems, Inc., San Diego, CA (United States). Mission Systems; Bishop, Edward E. [General Atomics Aeronautical Systems, Inc., San Diego, CA (United States). Mission Systems; Horndt, Volker [General Atomics Aeronautical Systems, Inc., San Diego, CA (United States). Mission Systems

    2014-06-01

    Median filtering reduces speckle in synthetic aperture radar (SAR) imagery while preserving edges, at the expense of coarsening the resolution, by replacing the center pixel of a sliding window by the median value. For shadow detection, this approach helps distinguish shadows from clutter more easily, while preserving shadow shape delineations. However, the nonlinear operation alters the shadow and clutter distributions and statistics, which must be taken into consideration when computing probability of detection and false alarm metrics. Depending on system parameters, median filtering can improve probability of detection and false alarm by orders of magnitude. Herein, we examine shadow probability of detection and false alarm in a homogeneous, ideal clutter background after median filter post-processing. Some comments on multi-look processing effects with and without median filtering are also made.

  3. Probing Solar Magnetic Field with the "Cosmic-Ray Shadow" of the Sun

    CERN Document Server

    Amenomori, M; Chen, D; Chen, T L; Chen, W Y; Cui, S W; Danzengluobu,; Ding, L K; Feng, C F; Feng, Zhaoyang; Feng, Z Y; Gou, Q B; Guo, Y Q; Hakamada, K; He, H H; He, Z T; Hibino, K; Hotta, N; Hu, Haibing; Hu, H B; Huang, J; Jia, H Y; Jiang, L; Kajino, F; Kasahara, K; Katayose, Y; Kato, C; Kawata, K; Labaciren,; Le, G M; Li, A F; Li, H J; Li, W J; Liu, C; Liu, J S; Liu, M Y; Lu, H; Meng, X R; Mizutani, K; Munakata, K; Nanjo, H; Nishizawa, M; Ohnishi, M; Ohta, I; Onuma, H; Ozawa, S; Qian, X L; Qu, X B; Saito, T; Saito, T Y; Sakata, M; Sako, T K; Shao, J; Shibata, M; Shiomi, A; Shirai, T; Sugimoto, H; Takita, M; Tan, Y H; Tateyama, N; Torii, S; Tsuchiya, H; Udo, S; Wang, H; Wu, H R; Xue, L; Yamamoto, Y; Yang, Z; Yasue, S; Yuan, A F; Yuda, T; Zhai, L M; Zhang, H M; Zhang, J L; Zhang, X Y; Zhang, Y; Zhang, Yi; Zhang, Ying; Zhaxisangzhu,; Zhou, X X

    2013-01-01

    We report on a clear solar-cycle variation of the Sun's shadow in the 10 TeV cosmic-ray flux observed by the Tibet air shower array during a full solar cycle from 1996 to 2009. In order to clarify the physical implications of the observed solar cycle variation, we develop numerical simulations of the Sun's shadow, using the Potential Field Source Surface (PFSS) model and the Current Sheet Source Surface (CSSS) model for the coronal magnetic field. We find that the intensity deficit in the simulated Sun's shadow is very sensitive to the coronal magnetic field structure, and the observed variation of the Sun's shadow is better reproduced by the CSSS model. This is the first successful attempt to evaluate the coronal magnetic field models by using the Sun's shadow observed in the TeV cosmic-ray flux.

  4. Encountering the shadow in rites of passage: a study in activations.

    Science.gov (United States)

    Casement, Ann

    2003-02-01

    Jung's concept of the shadow is explored in this paper through his writings on its realization and assimilation in which he says the shadow may be experienced as the regressed and denied 'other self' in each individual. However, this is not the whole picture, and he also points to the fact that the shadow contains more than something merely negative. While in no way treating them as 'patients', the paper will also touch on the experience of the anthropologist, Bronislaw Malinowski, and the writer, Joseph Conrad, in their personal encounters with the shadow. All three encountered the shadow whilst going through rites of passage of their own and each owes much to the Romantic Movement. In this context, attention is directed to the writings of the philosopher and theologian, Johann Gottfried von Herder, who discovered a deeper understanding of his destiny in the course of a sea voyage.

  5. Krüppel Expression Levels Are Maintained through Compensatory Evolution of Shadow Enhancers

    Directory of Open Access Journals (Sweden)

    Zeba Wunderlich

    2015-09-01

    Full Text Available Many developmental genes are controlled by shadow enhancers—pairs of enhancers that drive overlapping expression patterns. We hypothesized that compensatory evolution can maintain the total expression of a gene, while individual shadow enhancers diverge between species. To test this hypothesis, we analyzed expression driven by orthologous pairs of shadow enhancers from Drosophila melanogaster, Drosophila yakuba, and Drosophila pseudoobscura that control expression of Krüppel, a transcription factor that patterns the anterior-posterior axis of blastoderm embryos. We found that the expression driven by the pair of enhancers is conserved between these three species, but expression levels driven by the individual enhancers are not. Using sequence analysis and experimental perturbation, we show that each shadow enhancer is regulated by different transcription factors. These results support the hypothesis that compensatory evolution can occur between shadow enhancers, which has implications for mechanistic and evolutionary studies of gene regulation.

  6. Shadowing effects in Newton’s law from compact extra dimensions

    Science.gov (United States)

    Kleidis, K.; Oikonomou, V. K.

    2016-10-01

    One problem that appears in theories with compact extra dimensions is the shadowing phenomenon, which makes it difficult to identify the topology and the geometry of the extra-dimensional manifold, if it exists. In this paper, we address this problem from the perspective of Newton’s law modifications caused by compact extra dimensions. After providing the modifications cause by some of the most phenomenologically interesting compact manifolds, we qualitatively study and compare the modifications that these manifolds cause to Newton’s law. As we demonstrate, the shadowing phenomenon persists in this approach too, and it seems that the shadowing phenomenon is grouped in “shadowing zones”. At these points, it is impossible to distinguish which compact space causes the modification of Newton’s law. However, away from the shadowing zones, the effects of the different compact manifolds are distinguishable. It is possible that these effects can be observed in the next generation of Newton’s law experiments.

  7. Impact of Physical Layer Jamming on Wireless Sensor Networks with Shadowing and Multicasting

    Directory of Open Access Journals (Sweden)

    Nischay Bahl

    2012-07-01

    Full Text Available This paper analyzes the impact of a physical layer jamming on the performance of wireless sensor networks by performing exhaustive comparative simulations using multicasting and by employing varying intensity of shadowing (constant and log normal. Comprehensive result analysis reveals that jamming drastically degrades the legitimate traffic throughput in a network, and, the constant shadowing approach is a better fit for a static network, both, under static as well as mobile jammer environments, as compared to the log normal one. An improvement in sink-node packet delivery ratio by 15.02 % and 16.58 % was observed with static and mobile jammer environments respectively, under multicasting and constant shadowing mean of 8.0. Further, average sink-node packet delivery ratio with constant shadowing shows an improvement of 4.15% and 5.94%, using static and mobile jammer environment respectively, in comparison to the values obtained under log normal shadowing based network.

  8. Uniformity Masks Design Method Based on the Shadow Matrix for Coating Materials with Different Condensation Characteristics

    Directory of Open Access Journals (Sweden)

    Lichao Zhang

    2013-01-01

    Full Text Available An intuitionistic method is proposed to design shadow masks to achieve thickness profile control for evaporation coating processes. The proposed method is based on the concept of the shadow matrix, which is a matrix that contains coefficients that build quantitive relations between shape parameters of masks and shadow quantities of substrate directly. By using the shadow matrix, shape parameters of shadow masks could be derived simply by solving a matrix equation. Verification experiments were performed on a special case where coating materials have different condensation characteristics. By using the designed mask pair with complementary shapes, thickness uniformities of better than 98% are demonstrated for MgF2 ( and LaF3 ( simultaneously on a 280 mm diameter spherical substrate with the radius curvature of 200 mm.

  9. Krüppel Expression Levels Are Maintained through Compensatory Evolution of Shadow Enhancers.

    Science.gov (United States)

    Wunderlich, Zeba; Bragdon, Meghan D J; Vincent, Ben J; White, Jonathan A; Estrada, Javier; DePace, Angela H

    2015-09-22

    Many developmental genes are controlled by shadow enhancers—pairs of enhancers that drive overlapping expression patterns. We hypothesized that compensatory evolution can maintain the total expression of a gene, while individual shadow enhancers diverge between species. To test this hypothesis, we analyzed expression driven by orthologous pairs of shadow enhancers from Drosophila melanogaster, Drosophila yakuba, and Drosophila pseudoobscura that control expression of Krüppel, a transcription factor that patterns the anterior-posterior axis of blastoderm embryos. We found that the expression driven by the pair of enhancers is conserved between these three species, but expression levels driven by the individual enhancers are not. Using sequence analysis and experimental perturbation, we show that each shadow enhancer is regulated by different transcription factors. These results support the hypothesis that compensatory evolution can occur between shadow enhancers, which has implications for mechanistic and evolutionary studies of gene regulation.

  10. Fusion strategy of multi-resolution image combined with gray level co-occurrence matrix%结合灰度共生矩阵的多分辨率图像融合策略

    Institute of Scientific and Technical Information of China (English)

    阳魁; 黄新生; 徐婉莹

    2012-01-01

    多分辨率图像的融合策略是提升融合图像质量的关键.目前常用的融合策略都没有直接考虑融合图像的纹理信息,根据灰度共生矩阵( GLCM)能较好地反映纹理粗糙度和方向的特点,提出了一种结合灰度共生矩阵的多分辨率图像融合策略.首先计算多分辨率图像的低频和高频部分的灰度共生矩阵,然后将低频图像GLCM的能量和高频图像GLCM的对比度对应作为低频和高频系数选取的活性度量进行图像融合.实验表明,所提出的融合策略与目前常见的融合策略相比,在主观感官和客观评价上都能获得较好的融合效果.%Fusion strategy of multi-resolution image is the key to enhance the quality of integration image. The most commonly used strategies are not directly consider the image texture information. According to GLCM can reflect the characteristics of grain roughness and direction accurately, this paper proposed a fusion strategy of multi-resolution image which combined with GLCM. First,it calculated the GLCM of the low and high frequency part of the multi-resolution image. Then the energy of the low-frequency GLCM and the contrast of the high-frequency GLCM corresponded as activity measure for image fusion to selecte the low and high frequency coefficients. Experiments show that compared to the current common fusion strategy, the proposed method can make fusion effect better through subjective sensory and objective evaluation.

  11. Locating the shadow regions in LIDAR data: results on the SHARE 2012 dataset

    Science.gov (United States)

    Boyaci, Mustafa; Yuksel, Seniha E.

    2015-05-01

    In hyperspectral imaging, shadowy areas present a major problem as targets in shadow show decreased or no spectral signatures. One way to mitigate this problem is by the fusion of hyperspectral data with LiDAR data; since LiDAR data presents excellent information by providing elevation information, which can then be used to identify the regions of shadow. Although there is a lot of work to detect the shadowy areas, many are restricted to distinct platforms like ARGCIS, ENVI etc. The purpose of this study is to (i) detect the shadow areas and to (ii) give a shadowiness scale in LiDAR data with Matlab in an efficient way. For this work, we designed our Line of Sight (LoS) algorithm that is optimized to run in a Matlab interface. The LoS algorithm uses the sun angles (altitude and azimuth) and elevation of the earth; and marks the pixel as "in shadow" if there lies an object of higher elevation between a given pixel and the sun. This is computed for all pixels in the scene and a shadow map is generated. Further, if a pixel is marked as a shadow area, the algorithm assigns a different darkness level which is inversely proportional to the distance between the current pixel and the object that causes the shadow. With this shadow scale, it is both visually and computationally possible to distinguish the soft shadows from the dark shadows; an important information for hyperspectral imagery. The algorithm has been tested on the SHARE 2012 Avon AM dataset. We also show the effect of the shadowiness scale on the spectral signatures.

  12. Modeling of global variations and ring shadowing in Saturn's ionosphere

    Science.gov (United States)

    Moore, L. E.; Mendillo, M.; Müller-Wodarg, I. C. F.; Murr, D. L.

    2004-12-01

    A time-dependent one-dimensional model of Saturn's ionosphere has been developed as an intermediate step towards a fully coupled Saturn Thermosphere-Ionosphere Model (STIM). A global circulation model (GCM) of the thermosphere provides the latitude and local time dependent neutral atmosphere, from which a globally varying ionosphere is calculated. Four ion species are used (H +, H +2, H +3, and He +) with current cross-sections and reaction rates, and the SOLAR2000 model for the Sun's irradiance. Occultation data from the Voyager photopolarimeter system (PPS) are adapted to model the radial profile of the ultraviolet (UV) optical depth of the rings. Diurnal electron density peak values and heights are generated for all latitudes and two seasons under solar minimum and solar maximum conditions, both with and without shadowing from the rings. Saturn's lower ionosphere is shown to be in photochemical equilibrium, whereas diffusive processes are important in the topside. In agreement with previous 1-D models, the ionosphere is dominated by H + and H +3, with a peak electron density of ˜10 electrons cm -3. At low- and mid-latitudes, H + is the dominant ion, and the electron density exhibits a diurnal maximum during the mid-afternoon. At higher latitudes and shadowed latitudes (smaller ionizing fluxes), the diurnal maximum retreats towards noon, and the ratio of [H +]/[H +3] decreases, with H +3 becoming the dominant ion at altitudes near the peak (˜1200-1600 km) for noon-time hours. Shadowing from the rings leads to attenuation of solar flux, the magnitude and latitudinal structure of which is seasonal. During solstice, the season for the Cassini spacecraft's encounter with Saturn, attenuation has a maximum of two orders of magnitude, causing a reduction in modeled peak electron densities and total electron column contents by as much as a factor of three. Calculations are performed that explore the parameter space for charge-exchange reactions of H + with

  13. Phylogenetic Conservatism in Plant Phenology

    Science.gov (United States)

    Davies, T. Jonathan; Wolkovich, Elizabeth M.; Kraft, Nathan J. B.; Salamin, Nicolas; Allen, Jenica M.; Ault, Toby R.; Betancourt, Julio L.; Bolmgren, Kjell; Cleland, Elsa E.; Cook, Benjamin I.; Crimmins, Theresa M.; Mazer, Susan J.; McCabe, Gregory J.; Pau, Stephanie; Regetz, Jim; Schwartz, Mark D.; Travers, Steven E.

    2013-01-01

    Phenological events defined points in the life cycle of a plant or animal have been regarded as highly plastic traits, reflecting flexible responses to various environmental cues. The ability of a species to track, via shifts in phenological events, the abiotic environment through time might dictate its vulnerability to future climate change. Understanding the predictors and drivers of phenological change is therefore critical. Here, we evaluated evidence for phylogenetic conservatism the tendency for closely related species to share similar ecological and biological attributes in phenological traits across flowering plants. We aggregated published and unpublished data on timing of first flower and first leaf, encompassing 4000 species at 23 sites across the Northern Hemisphere. We reconstructed the phylogeny for the set of included species, first, using the software program Phylomatic, and second, from DNA data. We then quantified phylogenetic conservatism in plant phenology within and across sites. We show that more closely related species tend to flower and leaf at similar times. By contrasting mean flowering times within and across sites, however, we illustrate that it is not the time of year that is conserved, but rather the phenological responses to a common set of abiotic cues. Our findings suggest that species cannot be treated as statistically independent when modelling phenological responses.Closely related species tend to resemble each other in the timing of their life-history events, a likely product of evolutionarily conserved responses to environmental cues. The search for the underlying drivers of phenology must therefore account for species' shared evolutionary histories.

  14. Morphological phylogenetics of Bignoniaceae Juss.

    Directory of Open Access Journals (Sweden)

    Usama K. Abdel-Hameed

    2014-09-01

    Full Text Available The most recent classification of Bignoniaceae recognized seven tribes, Phylogenetic and monographic studies focusing on clades within Bignoniaceae had revised tribal and generic boundaries and species numbers for several groups, the portions of the family that remain most poorly known are the African and Asian groups. The goal of the present study is to identify the primary lineages of Bignoniaceae in Egypt based on macromorphological traits. A total of 25 species of Bignoniaceae in Egypt was included in this study (Table 1, along with Barleria cristata as outgroup. Parsimony analyses were conducted using the program NONA 1.6, preparation of data set matrices and phylogenetic tree editing were achieved in WinClada Software. The obtained cladogram showed that within the studied taxa of Bignoniaceae there was support for eight lineages. The present study revealed that the two studied species of Tabebuia showed a strong support for monophyly as well as Tecoma and Kigelia. It was revealed that Bignonia, Markhamia and Parmentiera are not monophyletic genera.

  15. The Shadow of Big Data: Data-Citizenship and Exclusion

    DEFF Research Database (Denmark)

    Rossi, Luca; Hjelholt, Morten; Neumayer, Christina

    2016-01-01

    The shadow of Big Data: data-citizenship and exclusion Big data are understood as being able to provide insights on human behaviour at an individual as well as at an aggregated societal level (Manyka et al. 2011). These insights are expected to be more detailed and precise than anything before...... thanks to the large volume of digital data and to the unobstrusive nature of the data collection (Fishleigh 2014). Within this perspective, these two dimensions (volume and unobstrusiveness) define contemporary big data techniques as a socio-technical offering to society, a live representation of itself....... More precisely, within a system theory approach (Luhmann 1982, 2010), large-scale big data work as a boundary-drawing operation where the difference between the system and its environment is reproduced. Here the result of system observation is defined by what is made visible as (big) data. Within...

  16. Constipation is casting a shadow over everyday life

    DEFF Research Database (Denmark)

    Tvistholm, Nina; Munch, Lene; Kjærgaard Danielsen, Anne

    2017-01-01

    and four qualitative. Three main themes crystallised from the results of the included studies: bodily experiences, everyday life shadowed by constipation and adverse psychological effects. Conclusion Constipation among older people was connected to subjective and comprehensive experiences. It had....... Background Constipation is a common and overlooked problem with an impact on everyday life, especially among older people. Older people seem to have individual preconceptions on constipation which can influence the strategies used to prevent and treat constipation. Design A systematic review, integrating...... studies. Search terms included constipation, elderly, aged, elderly people, aged people, quality of life, patient experience, patient perspective, meaning, emotion, psychological. Reference lists were searched manually. Results A total of nine studies were included in the review, five quantitative...

  17. AN ANALYSIS OF THE SHADOW ECONOMY IN EU COUNTRIES

    Directory of Open Access Journals (Sweden)

    Brindusa Mihaela Tudose

    2016-08-01

    Full Text Available The paper aims at analysing the dimension of the underground economy in the EU states between 2003 and 2015. In order to achieve this goal, we use qualitative and quantitative methods. In the first two sections of the study we resort to conceptualisation and bring up to date scientific contributions in the field of the shadow economy both in terms of its definition and the methods of quantifying the phenomenon. In the third section, based on the results of the latest research, we identify the dynamics of the underground economy on three levels: the EU-15 (before and after 2005; the EU-10 (before and after the accession of 10 countries in 2005 and the EU-3 (before and after 2007. The main conclusion is that regardless of the reporting level (national, European, world, the real size of the underground economy remains unknown.

  18. Shadow enhancers enable Hunchback bifunctionality in the Drosophila embryo.

    Science.gov (United States)

    Staller, Max V; Vincent, Ben J; Bragdon, Meghan D J; Lydiard-Martin, Tara; Wunderlich, Zeba; Estrada, Javier; DePace, Angela H

    2015-01-20

    Hunchback (Hb) is a bifunctional transcription factor that activates and represses distinct enhancers. Here, we investigate the hypothesis that Hb can activate and repress the same enhancer. Computational models predicted that Hb bifunctionally regulates the even-skipped (eve) stripe 3+7 enhancer (eve3+7) in Drosophila blastoderm embryos. We measured and modeled eve expression at cellular resolution under multiple genetic perturbations and found that the eve3+7 enhancer could not explain endogenous eve stripe 7 behavior. Instead, we found that eve stripe 7 is controlled by two enhancers: the canonical eve3+7 and a sequence encompassing the minimal eve stripe 2 enhancer (eve2+7). Hb bifunctionally regulates eve stripe 7, but it executes these two activities on different pieces of regulatory DNA--it activates the eve2+7 enhancer and represses the eve3+7 enhancer. These two "shadow enhancers" use different regulatory logic to create the same pattern.

  19. Integrated Differential Optical Shadow Sensor for Modular Gravitational Reference Sensor

    CERN Document Server

    Zoellner, Andreas; Sun, Ke-Xun

    2013-01-01

    The Laser Interferometer Space Antenna (LISA) is a proposed space mission for the detection of gravitational waves. It consists of three drag-free satellites flying in a triangular constellation. A gravitational reference sensor is used in conjunction with a laser interferometer to measure the distance between test masses inside the three satellites. Other future space mission such as DECIGO and BBO also require a gravitational reference sensor. The Modular Gravitational Reference Sensor (MGRS) is being designed for these purposes and consists of two different optical sensors and a UV LED charge management system. The Differential Optical Shadow Sensor (DOSS) is one of the optical sensors and measures the position of a spherical test mass with respect to the surrounding satellite. This measurement is used for the drag-free feedback control loop. This paper describes the most recent, third generation of the experimental setup for the DOSS that uses a fiber coupled super luminescent LED, an integrated mounting ...

  20. Photoabsorption on nuclei in the shadowing threshold region

    CERN Document Server

    Muccifora, V; Deppman, A; De Sanctis, E; Mirazita, M; Polli, E; Rossi, P; Burgwinkel, R; Hannappel, J; Klein, F; Menze, D W; Schwille, W J; Wehnes, F

    1998-01-01

    The energy and nuclear mass dependences of the total hadronic cross section in the energy range 0.5-2.6 GeV have been measured at Bonn using the SAPHIR tagged photon beam. The measurement, performed on C, Al, Cu, Sn and Pb, provides the first photoabsorption data in the region 1.2-1.7 GeV. The results show a significant reduction of the photoabsorption strength on the bound nucleon compared to the free nucleon case in the whole energy region. Above 1.2 GeV this reduction decreases with the nuclear density and can be interpreted as a signature of a low energy onset of the shadowing effect.

  1. Molecular Phylogenetics: Concepts for a Newcomer.

    Science.gov (United States)

    Ajawatanawong, Pravech

    2016-10-26

    Molecular phylogenetics is the study of evolutionary relationships among organisms using molecular sequence data. The aim of this review is to introduce the important terminology and general concepts of tree reconstruction to biologists who lack a strong background in the field of molecular evolution. Some modern phylogenetic programs are easy to use because of their user-friendly interfaces, but understanding the phylogenetic algorithms and substitution models, which are based on advanced statistics, is still important for the analysis and interpretation without a guide. Briefly, there are five general steps in carrying out a phylogenetic analysis: (1) sequence data preparation, (2) sequence alignment, (3) choosing a phylogenetic reconstruction method, (4) identification of the best tree, and (5) evaluating the tree. Concepts in this review enable biologists to grasp the basic ideas behind phylogenetic analysis and also help provide a sound basis for discussions with expert phylogeneticists.

  2. Tripartitions do not always discriminate phylogenetic networks.

    Science.gov (United States)

    Cardona, Gabriel; Rosselló, Francesc; Valiente, Gabriel

    2008-02-01

    Phylogenetic networks are a generalization of phylogenetic trees that allow for the representation of non-treelike evolutionary events, like recombination, hybridization, or lateral gene transfer. In a recent series of papers devoted to the study of reconstructibility of phylogenetic networks, Moret, Nakhleh, Warnow and collaborators introduced the so-called tripartition metric for phylogenetic networks. In this paper we show that, in fact, this tripartition metric does not satisfy the separation axiom of distances (zero distance means isomorphism, or, in a more relaxed version, zero distance means indistinguishability in some specific sense) in any of the subclasses of phylogenetic networks where it is claimed to do so. We also present a subclass of phylogenetic networks whose members can be singled out by means of their sets of tripartitions (or even clusters), and hence where the latter can be used to define a meaningful metric.

  3. Phylogenetic analysis of the spirochetes.

    Science.gov (United States)

    Paster, B J; Dewhirst, F E; Weisburg, W G; Tordoff, L A; Fraser, G J; Hespell, R B; Stanton, T B; Zablen, L; Mandelco, L; Woese, C R

    1991-10-01

    The 16S rRNA sequences were determined for species of Spirochaeta, Treponema, Borrelia, Leptospira, Leptonema, and Serpula, using a modified Sanger method of direct RNA sequencing. Analysis of aligned 16S rRNA sequences indicated that the spirochetes form a coherent taxon composed of six major clusters or groups. The first group, termed the treponemes, was divided into two subgroups. The first treponeme subgroup consisted of Treponema pallidum, Treponema phagedenis, Treponema denticola, a thermophilic spirochete strain, and two species of Spirochaeta, Spirochaeta zuelzerae and Spirochaeta stenostrepta, with an average interspecies similarity of 89.9%. The second treponeme subgroup contained Treponema bryantii, Treponema pectinovorum, Treponema saccharophilum, Treponema succinifaciens, and rumen strain CA, with an average interspecies similarity of 86.2%. The average interspecies similarity between the two treponeme subgroups was 84.2%. The division of the treponemes into two subgroups was verified by single-base signature analysis. The second spirochete group contained Spirochaeta aurantia, Spirochaeta halophila, Spirochaeta bajacaliforniensis, Spirochaeta litoralis, and Spirochaeta isovalerica, with an average similarity of 87.4%. The Spirochaeta group was related to the treponeme group, with an average similarity of 81.9%. The third spirochete group contained borrelias, including Borrelia burgdorferi, Borrelia anserina, Borrelia hermsii, and a rabbit tick strain. The borrelias formed a tight phylogenetic cluster, with average similarity of 97%. THe borrelia group shared a common branch with the Spirochaeta group and was closer to this group than to the treponemes. A single spirochete strain isolated fromt the shew constituted the fourth group. The fifth group was composed of strains of Serpula (Treponema) hyodysenteriae and Serpula (Treponema) innocens. The two species of this group were closely related, with a similarity of greater than 99%. Leptonema illini

  4. Phylogenetic diversity of Amazonian tree communities

    OpenAIRE

    Honorio Coronado, Eurídice N.; Dexter, Kyle G.; Pennington, R. Toby; Chave, Jérôme; Lewis, Simon L.; Alexiades, Miguel N.; Alvarez, Esteban; Alves de Oliveira, Atila; Amaral, Iêda L.; Araujo-Murakami, Alejandro; Arets, Eric J. M. M.; Aymard, Gerardo A.; Baraloto, Christopher; Bonal, Damien; Brienen, Roel

    2015-01-01

    Aim: To examine variation in the phylogenetic diversity (PD) of tree communities across geographical and environmental gradients in Amazonia. Location: Two hundred and eighty-three c. 1 ha forest inventory plots from across Amazonia. Methods: We evaluated PD as the total phylogenetic branch length across species in each plot (PDss), the mean pairwise phylogenetic distance between species (MPD), the mean nearest taxon distance (MNTD) and their equivalents standardized for species richness (ses...

  5. Relevant phylogenetic invariants of evolutionary models

    CERN Document Server

    Casanellas, Marta

    2009-01-01

    Recently there have been several attempts to provide a whole set of generators of the ideal of the algebraic variety associated to a phylogenetic tree evolving under an algebraic model. These algebraic varieties have been proven to be useful in phylogenetics. In this paper we prove that, for phylogenetic reconstruction purposes, it is enough to consider generators coming from the edges of the tree, the so-called edge invariants. This is the algebraic analogous to Buneman's Splits Equivalence Theorem. The interest of this result relies on its potential applications in phylogenetics for the widely used evolutionary models such as Jukes-Cantor, Kimura 2 and 3 parameters, and General Markov models.

  6. Alu elements and hominid phylogenetics

    Science.gov (United States)

    Salem, Abdel-Halim; Ray, David A.; Xing, Jinchuan; Callinan, Pauline A.; Myers, Jeremy S.; Hedges, Dale J.; Garber, Randall K.; Witherspoon, David J.; Jorde, Lynn B.; Batzer, Mark A.

    2003-01-01

    Alu elements have inserted in primate genomes throughout the evolution of the order. One particular Alu lineage (Ye) began amplifying relatively early in hominid evolution and continued propagating at a low level as many of its members are found in a variety of hominid genomes. This study represents the first conclusive application of short interspersed elements, which are considered nearly homoplasy-free, to elucidate the phylogeny of hominids. Phylogenetic analysis of Alu Ye5 elements and elements from several other subfamilies reveals high levels of support for monophyly of Hominidae, tribe Hominini and subtribe Hominina. Here we present the strongest evidence reported to date for a sister relationship between humans and chimpanzees while clearly distinguishing the chimpanzee and human lineages. PMID:14561894

  7. SHADOW EFFECT ON PHOTOVOLTAIC POTENTIALITY ANALYSIS USING 3D CITY MODELS

    Directory of Open Access Journals (Sweden)

    N. Alam

    2012-07-01

    Full Text Available Due to global warming, green-house effect and various other drawbacks of existing energy sources, renewable energy like Photovoltaic system is being popular for energy production. The result of photovoltaic potentiality analysis depends on data quality and parameters. Shadow rapidly decreases performance of the Photovoltaic system and it always changes due to the movement of the sun. Solar radiation incident on earth's atmosphere is relatively constant but the radiation at earth's surface varies due to absorption, scattering, reflection, change in spectral content, diffuse component, water vapor, clouds and pollution etc. In this research, it is being investigated that how efficiently real-time shadow can be detected for both direct and diffuse radiation considering reflection and other factors in contrast with the existing shadow detection methods using latest technologies and what is the minimum quality of data required for this purpose. Of course, geometric details of the building geometry and surroundings directly affect the calculation of shadows. In principle, 3D city models or point clouds, which contain roof structure, vegetation, thematically differentiated surface and texture, are suitable to simulate exact real-time shadow. This research would develop an automated procedure to measure exact shadow effect from the 3D city models and a long-term simulation model to determine the produced energy from the photovoltaic system. In this paper, a developed method for detecting shadow for direct radiation has been discussed with its result using a 3D city model to perform a solar energy potentiality analysis.

  8. Frustum-Traced Irregular Z-Buffers: Fast, Sub-pixel Accurate Hard Shadows.

    Science.gov (United States)

    Wyman, Chris; Hoetzlein, Rama; Lefohn, Aaron

    2016-05-25

    We further describe and analyze a real-time system for rendering antialiased hard shadows using irregular z-buffers (IZBs) that we first presented in Wyman et al. [1]. We focus on identifying bottlenecks, exploring these from an algorithmic complexity standpoint, and presenting techniques to improve performance. Our system remains interactive on a variety of game assets and CAD models while running at resolutions 1920 1080 and above and imposes no constraints on light, camera or geometry, allowing fully dynamic scenes without precomputation. We render sub-pixel accurate, 32 sample per pixel hard shadows at roughly twice the cost of a single sample per pixel. This allows us to smoothly animate even subpixel shadows from grass or wires without introducing spatial or temporal aliasing. Prior algorithms for irregular z-buffer shadows rely heavily on the GPU's compute pipeline. Instead we leverage the standard rasterization-based graphics pipeline, including hardware conservative raster and early-z culling. Our key observation is noting a duality between irregular z-buffer performance and shadow map quality; irregular z-buffering is most costly exactly where shadow maps exhibit the worst aliasing. This allows us to use common shadow map algorithms, which typically improve aliasing, to instead reduce our cost. Compared to state of the art ray tracers, we spawn similar numbers of triangle intersections per pixel yet completely rebuild our data structure in under 1 ms per frame.

  9. Use of Shadowing-Based Learning in an Allied Health Microbiology Course

    Directory of Open Access Journals (Sweden)

    Alex A. Lowrey

    2016-05-01

    Full Text Available Students in an undergraduate microbiology course for health professions majors perform a shadowing-based learning exercise for their course project. Students accomplish this by shadowing a health care professional of their choice, specifically incorporating basic microbiological concept themes into their observations. These concept themes include the biological nature, health effects, detection, and control of microorganisms. Upon completion of the shadowing experience, students present a concise report, which is graded on how well the students connect course scientific concepts with actual clinical practice.

  10. Shapes and Positions of Black Hole Shadows in Accretion Disks and Spin Parameters of Black Holes

    OpenAIRE

    Takahashi, Rohta

    2004-01-01

    Can we determine a spin parameter of a black hole by observation of a black hole shadow in an accretion disk? In order to answer this question, we make a qualitative analysis and a quantitative analysis of a shape and a position of a black hole shadow casted by a rotating black hole on an optically thick accretion disk and its dependence on an angular momentum of a black hole. We have found black hole shadows with a quite similar size and a shape for largely different black hole spin paramete...

  11. Shadow cast by a Kaluza-Klein spinning dilaton black hole

    CERN Document Server

    Amarilla, Leonardo

    2015-01-01

    We examine the shadow of a rotating Kaluza-Klein black hole in Einstein gravity coupled to a Maxwell field and a dilaton. The size and the shape of the shadow depend on the mass, the charge, and the angular momentum of the compact object. For a given mass, the size increases with the rotation parameter and decreases with the electric charge. The distortion with respect to the non rotating case grows with the charge and the rotation parameter. For fixed values of these parameters, the shadow is slightly larger and less deformed than in the Kerr-Newman case.

  12. Possible imprints of cosmic strings in the shadows of galactic black holes

    CERN Document Server

    Tinchev, Vassil K

    2013-01-01

    We examine the shadow cast by the Kerr black hole pierced by a cosmic string. The observable images depend not only on the black hole spin parameter and the angle of inclination, but also on the deficit angle yielded by the cosmic string. The dependence of the observable characteristics of the shadow on the deficit angle is explored. The imprints in the black hole shadow left by the presence of a cosmic string can serve as method for observational detection of the cosmic strings.

  13. Shapes and Positions of Black Hole Shadows in Accretion Disks and Spin Parameters of Black Holes

    OpenAIRE

    Takahashi, Rohta

    2004-01-01

    Can we determine a spin parameter of a black hole by observation of a black hole shadow in an accretion disk? In order to answer this question, we make a qualitative analysis and a quantitative analysis of a shape and a position of a black hole shadow casted by a rotating black hole on an optically thick accretion disk and its dependence on an angular momentum of a black hole. We have found black hole shadows with a quite similar size and a shape for largely different black hole spin paramete...

  14. Cold Nuclear Matter effects on J/psi production at RHIC: comparing shadowing models

    Energy Technology Data Exchange (ETDEWEB)

    Ferreiro, E.G.; /Santiago de Compostela U.; Fleuret, F.; /Ecole Polytechnique; Lansberg, J.P.; /SLAC; Rakotozafindrabe, A.; /SPhN, DAPNIA, Saclay

    2009-06-19

    We present a wide study on the comparison of different shadowing models and their influence on J/{psi} production. We have taken into account the possibility of different partonic processes for the c{bar c}-pair production. We notice that the effect of shadowing corrections on J/{psi} production clearly depends on the partonic process considered. Our results are compared to the available data on dAu collisions at RHIC energies. We try different break up cross section for each of the studied shadowing models.

  15. Metal-Insulator Transition of Solid Hydrogen by the Antisymmetric Shadow Wave Function

    CERN Document Server

    Calcavecchia, Francesco

    2016-01-01

    We present an improved shadow wave function approach to quantum Monte Carlo for large-scale fermionic systems. It is based on employing the antisymmetric shadow wave function in conjunction with the Gaussian determinant method to reduce the variance and an enhanced stochastic reconfiguration scheme to efficiently optimize the trail wave function, as well as refined twist averaged boundary conditions and periodic coordinates techniques. The predictive power of this approach is demonstrated by revisiting the pressure-induced metal-insulator-transition of solid hydrogen. It is found that the ameliorated accuracy of the antisymmetric shadow wave function results in a significantly increased transition pressure.

  16. When a giant falls, dwarfs have no shadow

    Directory of Open Access Journals (Sweden)

    Juan Gérvas

    2011-06-01

    Full Text Available It is said that in times of war old people bury young men. As we live in times of peace, and we are old, youngsters will need to bury us. It is said that we become good people after we die. But some of us were good before dying. They were good, generous and honored, wise and tender, effectively human. Some who passed away used to give us a cozy and protective shadow, and their absence leaves us unsheltered, alone with danger. A long time ago, one of our children asked to us: “When an old wise man dies, where does his knowledge and experience go to?”. We were not quite sure about the answer. “When this person has family and friends, they all learn from him. Thus, there will be a lot in their hearts and minds, and his/her kindness, culture, wisdom and accomplishments will be a part of memory, which will pass from generation to generation; it has been this way since the beginning of humanity. If this person diffused activities and work, whether written or illustrated, these will be his/her own words, and this person may be seen and revisited from time to time. Sometimes, words remain and we do not even know to whom they belong to, like Gilgamesh and his poem. Other times, authorship is neglected, even if we know who the author is, like Aristotle. And, other times, memory is alive and recent, like the work of Albert Einstein”. At that time, we did not think about it – but we do now – when a giant dies, we are left without a shadow. Barbara Starfield passed away, a giant in Primary Health Care (PHC, and her protective shadow abandoned us. She was a wise elderly woman, even though she looked young and looked like a student. Barbara Starfield had friends and family members who are capable of passing on her legacy of knowledge, kindness, culture, and wisdom, including many of her deeds and anecdotes. Barbara Starfield also leaves multiple registers, articles, books and presentations, which will serve as a path for others to go further. She

  17. Waiting for Shadows from the Distant Solar System

    Science.gov (United States)

    Kohler, Susanna

    2016-03-01

    How can we hope to measure the hundreds of thousands of objects in our distant solar system? A team of astronomers is harnessing citizen science to begin to tackle this problem!A light curve from an occultation collected by a RECON site in Quincy, California. As the objects shadow passes, the background stars light dims. [RECON/Charley Arrowsmith (Feather River College)]Occultation InformationEstimates currently place the number of Kuiper belt objects larger than 100 km across at over 100,000. Knowing the sizes and characteristics of these objects is important for understanding the composition of the outer solar system and constraining models of the solar systems formation and evolution.Unfortunately, measuring small, dim bodies at large distances is incredibly difficult! One of the best ways to obtain the sizes of these objects is to watch as they occult a distant star. Timing the object as it passes across the face of the star can give us a good measure of its size and shape, when observed from multiple stations in the path of the shadow.An Extended NetworkOccultations by nearby objects (like main-belt asteroids) can be predicted fairly accurately, but those by trans-Neptunian objects are much more poorly constrained. Only ~900 trans-Neptunian objects have approximately known paths, and occultation-shadow predictions for these objects are often only accurate to ~1000km on the Earths surface. So how can we ensure that theres a telescope in the right location, ready to observe when an occultation occurs?Map of the 56 RECON sites distributed over 2000 km in the western United States. [Buie et al. 2016]The simplest answer is to set up a huge network of observing stations, and wait for the shadows to come to the network. With this approach, even if the predicted path isnt precisely known, some of the stations will still observe the occultation.Due to the number of stations needed, this project lends itself perfectly to citizen science. In a recently published paper by

  18. Conflicting phylogenetic position of Schizosaccharomyces pombe

    NARCIS (Netherlands)

    Kuramae, Eiko E.; Robert, Vincent; Snel, Berend; Boekhout, Teun

    2006-01-01

    The phylogenetic position of the fission yeast Schizosaccharomyces pombe in the fungal Tree of Life is still controversial. Three alternative phylogenetic positions have been proposed in the literature, namely (1) a position basal to the Hemiascomycetes and Euascomycetes, (2) a position as a sister

  19. Efficient Computation of Popular Phylogenetic Tree Measures

    DEFF Research Database (Denmark)

    Tsirogiannis, Constantinos; Sandel, Brody Steven; Cheliotis, Dimitris

    2012-01-01

    Given a phylogenetic tree $\\mathcal{T}$ of n nodes, and a sample R of its tips (leaf nodes) a very common problem in ecological and evolutionary research is to evaluate a distance measure for the elements in R. Two of the most common measures of this kind are the Mean Pairwise Distance...... software package for processing phylogenetic trees....

  20. Insect phylogenetics in the digital age.

    Science.gov (United States)

    Dietrich, Christopher H; Dmitriev, Dmitry A

    2016-12-01

    Insect systematists have long used digital data management tools to facilitate phylogenetic research. Web-based platforms developed over the past several years support creation of comprehensive, openly accessible data repositories and analytical tools that support large-scale collaboration, accelerating efforts to document Earth's biota and reconstruct the Tree of Life. New digital tools have the potential to further enhance insect phylogenetics by providing efficient workflows for capturing and analyzing phylogenetically relevant data. Recent initiatives streamline various steps in phylogenetic studies and provide community access to supercomputing resources. In the near future, automated, web-based systems will enable researchers to complete a phylogenetic study from start to finish using resources linked together within a single portal and incorporate results into a global synthesis.

  1. THE OBJECTIFICATION OF DEFINITION OF THE PURCHASING POWER OF CONSUMERS IN SHADOW ECONOMY

    National Research Council Canada - National Science Library

    Tyukhtenko, N; Makarenko, S; Oliynik, N

    2016-01-01

    .... Proposed the method of calculating the correction coefficient with a view to determining the level of objectification purchasing power of consumers in a shadow economy and the potential capacity...

  2. Leading twist nuclear shadowing, nuclear generalized parton distributions and nuclear DVCS at small x

    Energy Technology Data Exchange (ETDEWEB)

    Guzey, Vadim; Goeke, Klaus; Siddikov, Marat

    2009-01-01

    We generalize the leading twist theory of nuclear shadowing and calculate quark and gluon generalized parton distributions (GPDs) of spinless nuclei. We predict very large nuclear shadowing for nuclear GPDs. In the limit of the purely transverse momentum transfer, our nuclear GPDs become impact parameter dependent nuclear parton distributions (PDFs). Nuclear shadowing induces non-trivial correlations between the impact parameter $b$ and the light-cone fraction $x$. We make predictions for the deeply virtual Compton scattering (DVCS) amplitude and the DVCS cross section on $^{208}$Pb at high energies. We calculate the cross section of the Bethe-Heitler (BH) process and address the issue of the extraction of the DVCS signal from the $e A \\to e \\gamma A$ cross section. We find that the $e A \\to e \\gamma A$ differential cross section is dominated by DVCS at the momentum transfer $t$ near the minima of the nuclear form factor. We also find that nuclear shadowing leads

  3. The Close Objects Buffer : A Sharp Shadow Detection Technique for Radiosity Methods

    NARCIS (Netherlands)

    Telea, A.C.; Overveld, C.W.A.M. van

    1998-01-01

    Detecting sharp illumination variations such as shadow boundaries is an important problem for radiosity methods. Such illumination variations are captured using a nonuniform mesh that refines the areas exhibiting high illumination gradients. Nonuniform meshing techniques like discontinuity meshing o

  4. 77 FR 39319 - Culturally Significant Objects Imported for Exhibition Determinations: “Bodies and Shadows...

    Science.gov (United States)

    2012-07-02

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF STATE Culturally Significant Objects Imported for Exhibition Determinations: ``Bodies and Shadows: Caravaggio and...: Caravaggio and His Legacy'' imported from abroad for temporary exhibition within the United States, are...

  5. Book review: Confronting the Shadow Education System: What Government Policies for What Private Tutoring'

    Directory of Open Access Journals (Sweden)

    Keith Watson

    2012-10-01

    Full Text Available Book Review Confronting the Shadow Education System: What Government Policies for What Private Tutoring' By Mark Bray (2009, 135pp. ISBN: 078-92-803-1333-8, Paris: IIEP/UNESCO Publishing

  6. Reduction of implantation shadowing effect by dual-wavelength exposure photo process

    CERN Document Server

    Gu, Yiming; Lee Sang Yun; Roche, William; Sturtevant, John

    2003-01-01

    As transistor engineering continues to well below 100 nm length devices, ion implantation process tolerances are making these formerly "non-critical" lithography levels more and more difficult. In order to minimize the channeling effect and to obtain a controllable profile of dopant, an angle implantation is often required. However, a shadow area of resist pattern is always accompanied with an angle implantation. This shadowing effect consumes silicon real estate, and reduces the line edge placement (LEP) tolerances. Therefore, methodologies to reduce the shadowing effect in angled implantation become a critical consideration not only for device engineering but also for photolithography. Based on the model analysis, simulation and experiments, this paper presents an effective novel process utilizing dual-wavelength exposure (DWE) to reduce the shadowing effect. The DWE process is realized by two consecutive exposures for an I-line resist with a DUV stepper/scanner and an I-line stepper. The process leverages ...

  7. The effects of shadow removal on across-date settlement type classification of quickbird images

    CSIR Research Space (South Africa)

    Luus, FPS

    2012-07-01

    Full Text Available QuickBird imagery acquired on separate dates may have significant differences in viewing- and illumination geometries, which can negatively impact across-date settlement type classification accuracy. The effect of cast shadows on classification...

  8. SHADOW ECONOMY AND ITS RELATIONS WITH TAX SYSTEM, BUDGET DEFICIT AND MACROECONOMIC INDICATORS

    Directory of Open Access Journals (Sweden)

    I. Savych

    2015-03-01

    Full Text Available The paper analyzes the influence of the shadow economy on the tax system, state budget and a number of macroeconomic parameters of Ukraine such as poverty, income levels, corruption, GDP per capita, public debt, budget violations etc. The results of our research show that level of corruption, monopolization and budget violations are considered key factors that stimulate the shadowing of the economy. On the other hand, a number of researchers state that the average wage level is a strong destimulating factor for the shadow economy. The analysis given uncovers a robust relationship between the corruption and the size of the shadow economy when perceptions-based indices of corruption are used.

  9. The X-ray shadow of the high-latitude molecular cloud MBM 12

    Science.gov (United States)

    Snowden, S. L.; Mccammon, D.; Verter, F.

    1993-01-01

    ROSAT XRT/PSPC observations show a deep shadow cast by the high-latitude molecular cloud MBM 12 in the 3/4 keV diffuse background. Modeling of the shadow implies that less than 20 percent of the typical high-latitude 3/4 keV diffuse background intensity is emitted in front of the cloud (D = 60-70 pc). A weaker shadow consistent with the lower optical depth at higher energies was observed in the 1.5 keV band. Since little shadowing was seen in the 1/4 keV band, this observation places strong constraints on the amount of 0.5-2 keV emission that is intermixed with the source of the observed 1/4 keV flux.

  10. Optimizing Phylogenetic Queries for Performance.

    Science.gov (United States)

    Jamil, Hasan M

    2017-08-24

    The vast majority of phylogenetic databases do not support declarative querying using which their contents can be flexibly and conveniently accessed and the template based query interfaces they support do not allow arbitrary speculative queries. They therefore also do not support query optimization leveraging unique phylogeny properties. While a small number of graph query languages such as XQuery, Cypher and GraphQL exist for computer savvy users, most are too general and complex to be useful for biologists, and too inefficient for large phylogeny querying. In this paper, we discuss a recently introduced visual query language, called PhyQL, that leverages phylogeny specific properties to support essential and powerful constructs for a large class of phylogentic queries. We develop a range of pruning aids, and propose a substantial set of query optimization strategies using these aids suitable for large phylogeny querying. A hybrid optimization technique that exploits a set of indices and ``graphlet" partitioning is discussed. A ``fail soonest" strategy is used to avoid hopeless processing and is shown to produce dividends. Possible novel optimization techniques yet to be explored are also discussed.

  11. Rough surfaces: Is the dark stuff just shadow?. ;Who knows what evil lurks in the hearts of men? The shadow knows!;☆

    Science.gov (United States)

    Cuzzi, Jeffrey N.; Chambers, Lindsey B.; Hendrix, Amanda R.

    2017-06-01

    Remote observations of the surfaces of airless planetary objects are fundamental to inferring the physical structure and compositional makeup of the surface material. A number of forward models have been developed to reproduce the photometric behavior of these surfaces, based on specific, assumed structural properties such as macroscopic roughness and associated shadowing. Most work of this type is applied to geometric albedos, which are affected by complicated effects near zero phase angle that represent only a tiny fraction of the net energy reflected by the object. Other applications include parameter fits to resolved portions of some planetary surface as viewed over a range of geometries. The spherical albedo of the entire object (when it can be determined) captures the net energy balance of the particle more robustly than the geometric albedo. In most treatments involving spherical albedos, spherical albedos and particle phase functions are often treated as if they are independent, neglecting the effects of roughness. In this paper we take a different approach. We note that whatever function captures the phase angle dependence of the brightness of a realistic rough, shadowed, flat surface element relative to that of a smooth granular surface of the same material, it is manifested directly in both the integral phase function and the spherical albedo of the object. We suggest that, where broad phase angle coverage is possible, spherical albedos may be easily corrected for the effects of shadowing using observed (or assumed) phase functions, and then modeled more robustly using smooth-surface regolith radiative transfer models without further imposed (forward-modeled) shadowing corrections. Our approach attributes observed ;powerlaw; phase functions of various slope (and ;linear; ranges of magnitude-vs.-phase angle) to shadowing, as have others, and goes in to suggest that regolith-model-based inferences of composition based on shadow-uncorrected spherical

  12. Production structure and Cost efficiency of irrigated agriculture: A shadow cost approach

    OpenAIRE

    Zaibet, L.; Salah Bachta, Mohamed; Ben Salem, H.

    2005-01-01

    International audience; The improvement of irrigated agriculture needs sound performance assessment based on economic principles. This is particularly relevant to design adequate policies in terms of water allocation. In this paper we endeavour to assess irrigation efficiency using a behavioural approach in which the cost function (shadow cost) is based on shadow prices of inputs. This approach is useful to derive price distortion coefficients to indicate the level of allocative efficiency in...

  13. Activation of the Human MT Complex by Motion in Depth Induced by a Moving Cast Shadow.

    Science.gov (United States)

    Katsuyama, Narumi; Usui, Nobuo; Taira, Masato

    2016-01-01

    A moving cast shadow is a powerful monocular depth cue for motion perception in depth. For example, when a cast shadow moves away from or toward an object in a two-dimensional plane, the object appears to move toward or away from the observer in depth, respectively, whereas the size and position of the object are constant. Although the cortical mechanisms underlying motion perception in depth by cast shadow are unknown, the human MT complex (hMT+) is likely involved in the process, as it is sensitive to motion in depth represented by binocular depth cues. In the present study, we examined this possibility by using a functional magnetic resonance imaging (fMRI) technique. First, we identified the cortical regions sensitive to the motion of a square in depth represented via binocular disparity. Consistent with previous studies, we observed significant activation in the bilateral hMT+, and defined functional regions of interest (ROIs) there. We then investigated the activity of the ROIs during observation of the following stimuli: 1) a central square that appeared to move back and forth via a moving cast shadow (mCS); 2) a segmented and scrambled cast shadow presented beside the square (sCS); and 3) no cast shadow (nCS). Participants perceived motion of the square in depth in the mCS condition only. The activity of the hMT+ was significantly higher in the mCS compared with the sCS and nCS conditions. Moreover, the hMT+ was activated equally in both hemispheres in the mCS condition, despite presentation of the cast shadow in the bottom-right quadrant of the stimulus. Perception of the square moving in depth across visual hemifields may be reflected in the bilateral activation of the hMT+. We concluded that the hMT+ is involved in motion perception in depth induced by moving cast shadow and by binocular disparity.

  14. The movement of shadows: a teaching proposal for the secondary school

    OpenAIRE

    Gangui, Alejandro; Iglesias, Maria; Quinteros, Cynthia

    2009-01-01

    A didactic sequence of activities on some topics of Astronomy, related mainly with the length and orientation of shadows cast by a gnomon, the movement of shadows during daytime in different seasons of the year, and finding the true astronomical North, is fully developed. It also includes a discussion of observations from different frames of reference and of some topics in the history of science to enrich a debate among students, as well as the construction of a simplified model for the appar...

  15. Simplified Least Squares Shadowing sensitivity analysis for chaotic ODEs and PDEs

    Energy Technology Data Exchange (ETDEWEB)

    Chater, Mario, E-mail: chaterm@mit.edu; Ni, Angxiu, E-mail: niangxiu@mit.edu; Wang, Qiqi, E-mail: qiqi@mit.edu

    2017-01-15

    This paper develops a variant of the Least Squares Shadowing (LSS) method, which has successfully computed the derivative for several chaotic ODEs and PDEs. The development in this paper aims to simplify Least Squares Shadowing method by improving how time dilation is treated. Instead of adding an explicit time dilation term as in the original method, the new variant uses windowing, which can be more efficient and simpler to implement, especially for PDEs.

  16. Vampirism as a Shadow in Bram Stoker’s Dracula

    Directory of Open Access Journals (Sweden)

    Yujin Jang

    2014-12-01

    Full Text Available Through the studies of literal and metaphorical meanings of eating in Bram Stoker’s Dracula (1897, this article investigates how the depictions of food and eating culture in Transylvania are the results of misrepresentations. Contrast to the illustrations about the consumptions of food in the Western table which accompanies the spirit of unity, the predatory images of vampires in Transylvania can be easily associated with an idea that communion is absent in the foreign land. The purpose of this article is, thus, to subvert the binary oppositions between East and West, with the focus on the descriptions of food and eating. For this goal, the examinations in this article include: three female vampires’ language which involves the sense of communion, the Western characters’ eating at a table which turns out to be a defective place in achieving the spirit of unity, and a lunatic character R.M. Renfield’s abnormal eating habits that can be interpreted within the contemporary socioeconomic contexts. Ultimately, this article is to show how the vampiric images in Stoker’s Dracula function as shadows that cover the violence of the Western middle-class capitalists in the contemporary capital-oriented society.

  17. Observing The Cosmic Ray Moon Shadow With VERITAS

    CERN Document Server

    Bird, Ralph

    2015-01-01

    The Earth is subjected to a uniform flux of very-high-energy (VHE, E > 100 GeV) cosmic rays unless they are obscured by an object, such as the Moon, in which case a deficit or shadow is created. Since cosmic rays are charged this deficit is deflected by the Earth's magnetic field, enabling the rigidity of the obstructed cosmic rays to be determined. Measurement of the relative deficits of different species enables the positron fraction and the antiproton ratio to be measured. The April 15, 2014 lunar eclipse was visible with the VERITAS Cherenkov telescopes, which allowed (with special UV bandpass filters) 74 minutes of direct observations of the Moon and the associated deficit in the cosmic-ray flux. The results of this observation are presented. In addition VERITAS has been conducting a series of observations by pointing close to a partially illuminated Moon, with a reduced photomultiplier tube high voltage and UV bandpass filters. We present the technique developed for these observations and their current ...

  18. Current treatment of antiphospholipid syndrome: lights and shadows.

    Science.gov (United States)

    Espinosa, Gerard; Cervera, Ricard

    2015-10-01

    For patients with antiphospholipid syndrome (APS), the consensus is to treat those who develop thrombosis with long-term oral anticoagulation therapy and to prevent obstetric manifestations by use of aspirin and heparin. These recommendations are based on data from randomized controlled trials and observational studies. Despite this body of knowledge, areas of uncertainty regarding the management of APS exist where evidence is scarce or nonexistent. In other words, for a subset of patients the course of management is unclear. Some examples are patients with 'seronegative' APS, those who do not fulfil the formal (clinical or serological) classification criteria for definite APS, and those with recurrent thrombotic events despite optimal anticoagulation. Other challenges include the treatment of clinical manifestations not included in the classification criteria, such as haematologic manifestations (thrombocytopenia and haemolytic anaemia), neurologic manifestations (chorea, myelitis and multiple sclerosis-like lesions), and nephropathy and heart valve disease associated with antiphospholipid antibodies (aPL), as well as the possible withdrawal of anticoagulation treatment in selected cases of thrombotic APS in which assays for aPL become persistently negative. This Review focuses on the current recommendations for thrombotic and obstetric manifestations of APS, as well as the management of difficult cases. Some aspects of treatment, such as secondary prophylaxis of venous thrombosis, are based on strong evidence--the 'lights' of APS treatment. Conversely, other areas, such as the treatment of non-criteria manifestations of APS, are based only on expert consensus or common sense and remain the 'shadows' of APS therapy.

  19. Shadows cast on the transition disk of HD 135344B

    CERN Document Server

    Stolker, T; Avenhaus, H; Min, M; de Boer, J; Ginski, C; Schmid, H M; Juhasz, A; Bazzon, A; Waters, L B F M; Garufi, A; Augereau, J -C; Benisty, M; Boccaletti, A; Henning, Th; Maire, A -L; Menard, F; Meyer, M R; Langlois, M; Pinte, C; Quanz, S P; Thalmann, C; Beuzit, J -L; Carbillet, M; Costille, A; Dohlen, K; Feldt, M; Gisler, D; Mouillet, D; Pavlov, A; Perret, D; Petit, C; Pragt, J; Rochat, S; Roelfsema, R; Salasnich, B; Soenke, C; Wildi, F

    2016-01-01

    The protoplanetary disk of the F-type star HD 135344B (SAO 206462) is in a transition stage and shows many intriguing structures both in scattered light and thermal millimeter emission which are possibly related to planet formation processes and planet-disk interactions. We have carried out high-contrast polarimetric differential imaging (PDI) observations with VLT/SPHERE and obtained the first optical polarized scattered light images with the sub-instrument ZIMPOL in R- and I-band. Additionally, near-infrared polarimetric observations were done with IRDIS in Y- and J-band. We will use the scattered light images, surface brightness profiles and color to study in detail disk structures and brightness variations. The scattered light images reveal with unprecedented sensitivity and angular resolution the spiral arm structure of the disk as well as the inner disk cavity of 25 au in all filters. Multiple shadow features are discovered on the outer disk and the observations of the two epochs show indications of var...

  20. Shadow Prices of Selected Agricultural Commodities – The Czech Case

    Directory of Open Access Journals (Sweden)

    Patrik Sieber

    2016-10-01

    Full Text Available The main objective of the paper is to contribute to practical applicability of the CBA in the agricultural sector by exploring the chances to estimate Czech social values of selected agricultural commodities using available statistical data. More specifically, we try to analyse for which commodities secondary data sets are available from which we may deduce the estimates of shadow price ratios, then to estimate SPRs for selected agricultural commodities and to analyse and discuss the applicability of such estimates in practical appraisal with respect to theoretically ideal measures and resulting available measures as well as with respect to the situation in which the CBA analyst typically is. We selected the following commodities: poultry, pigs, bulls, milk, rapeseed, maize, barley and wheat as items more suitable for SPR estimates mostly because of the data availability and the internal homogeneity of the items, which was closer to the theoretically required values than for other commodities. Under additional simplifying assumptions, we estimated SPR proxies for the particular commodities and finally summarized the pros and cons for application of SPR alternatives.

  1. Compression and Multi-Resolution Rendering of Sparse Voxels Based on Wavelet%基于小波的稀疏体素数据压缩与多分辨实时绘制

    Institute of Scientific and Technical Information of China (English)

    薛俊杰; 赵罡; 肖文磊

    2016-01-01

    为减少多分辨稀疏体素的存储空间并提高其绘制效率,提出一种基于小波的稀疏体素数据压缩与实时绘制算法。在稀疏体素生成阶段,基于小波的多分辨和稀疏体素的稀疏特性,利用多级三维 Haar 小波变换将高分辨率的稀疏体素转换为低分辨稀疏体素和多级细节信息,并采用紧凑的编码方式对小波系数进行编码,实现对多层级稀疏体素的数据压缩;在交互绘制阶段,结合稀疏体素八叉树光线投射算法,以低分辨体素节点为交互过程中的着色计算图元,交互过程终止后通过三维 Harr 小波逆变换逐级添加细节信息还原得到高分辨体素,进而实现多分辨绘制;最后充分利用多核 CPU 并行加速多分辨光线投射算法。对不同复杂度的面片模型进行压缩与绘制,实例计算表明,该算法高效且易于实现。%To reduce the storage size and improve the rendering efficiency of multi-resolution sparse voxels, a wavelet based compression and rendering algorithm is proposed. At the building stage of sparse voxels, according to the multi-resolution characteristic of wavelet and the sparsity of voxel structure, high-resolution sparse voxels were transformed into low-resolution sparse voxels and multi-level detail information by employing 3D Haar wavelet transform, and the wavelet coefficients were encoded with a compact encoding method. At the interactive rendering phase, in order to implement multi-resolution rendering, the low-resolution voxels were selected as shading primitives during the interaction. After the interaction process, the details were added to the coarse-grained voxels level by level through the inverse transform of 3D Haar wavelet to restore high-resolution voxels. Lastly, the rendering algorithm was accelerated in parallel by utilizing multi-core CPU. The experimental results show that the proposed algorithm provides an efficient and achievable way to

  2. Digital gray-level transformation for the reduction of redundant shadows in rotational panoramic radiography.

    Science.gov (United States)

    Hayakawa, Y; Wakoh, M; Yamamoto, K; Ueno, H; Kuroyanagi, K

    1990-08-01

    In rotational panoramic radiography, the tomographic motion in combination with a slit scanning method make an image layer wide. But some objects outside the image layer are hard to blur and they result to redundant shadows. The gray-level transformation, as one form of digital image processing for the reduction of these redundant shadows, was evaluated. Two methods, the gamma transformation and the histogram flattening method, were examined. A drum scanner was used as the image scanner. The panoramic image on the x-ray film was turned into an 8 bit digital image on the image memory, which had the size of a 512 x 480 matrix. In rotational panoramic radiography, there are low density and contrast regions where redundant shadows of the cervical vertebrae and the mandibular ramus are superimposed on the tomographic image. The histogram of the gray-level was suppressed for the lower gray-levels. The stretching of this gray-level distribution was effective in the reducing redundant shadows. When processed by gamma transformation, the smaller gamma coefficient below 1.0 clarified the tomographic image, and when processed by the histogram flattening method, the setting of the level (L) value around 64-128 effectively reduced the redundant shadows. However, the effectiveness of both gray-level transformations was greatest in restricted cases in which the area where redundant shadows were superimposed on the tomographic image was comparatively large.

  3. Double shadow of a regular phantom black hole as photons couple to the Weyl tensor

    Energy Technology Data Exchange (ETDEWEB)

    Huang, Yang; Chen, Songbai; Jing, Jiliang [Hunan Normal University, Institute of Physics and Department of Physics, Changsha, Hunan (China); Hunan Normal University, Key Laboratory of Low Dimensional Quantum Structures and Quantum Control of Ministry of Education, Changsha, Hunan (China); Hunan Normal University, Synergetic Innovation Center for Quantum Effects and Applications, Changsha, Hunan (China)

    2016-11-15

    We have studied the shadow of a regular phantom black hole as photons couple to the Weyl tensor. We find that due to the coupling photons with different polarization directions propagate along different paths in the spacetime so that there exists a double shadow for a black hole, which is quite different from that in the non-coupling case where only a single shadow emerges. The overlap region of the double shadow, the umbra, of the black hole increases with the phantom charge and decreases with the coupling strength. The dependence of the penumbra on the phantom charge and the coupling strength is converse to that of the umbra. Combining with the supermassive central object in our Galaxy, we estimated the shadow of the black hole as the photons couple to the Weyl tensor. Our results show that the coupling brings about richer behaviors of the propagation of coupled photon and the shadow of the black hole in the regular phantom black hole spacetime. (orig.)

  4. A New Index to Perform Shadow Detection in GeoEye-1 Images

    Directory of Open Access Journals (Sweden)

    Claudio Meneghini

    2015-10-01

    Full Text Available With the introduction of new satellites for earth monitoring characterized by very high resolution (VHR sensors, new algorithms to recognize shadow in the supplied images are necessary. Automatic shadow detection can enhance the interpretability of the images in several applications such as classification and change detection. Several approaches are present in literature for shadow detection and their adaptation and particularization for VHR satellite images are still in evolution. The goal of this paper is to propose a new index for shadow detection based on multispectral files processing. GeoEye-1 satellite data are used for this study: IHS pan-sharpening method is applied to transfer pixel dimensions of the panchromatic image (spatial resolution: 0.5 m x 0.5 m into the multispectral images (2 m x 2 m; an index named ERGAS is used to test the quality of the resulting raster files. Dealing with the problem of the shadow detection, a new index is defined to identify the affected pixels both in the original as well as pan-sharpened images. The results are compared with them by another index named ratio that is generally applied for shadow detection in multispectral images: issues and advantages, derived by using the proposed technique, are discussed.

  5. The Relation of Shadow Systems and ERP Systems—Insights from a Multiple-Case Study

    Directory of Open Access Journals (Sweden)

    Melanie Huber

    2016-01-01

    Full Text Available ERP systems integrate a major part of all business processes and organizations include them in their IT service management. Besides these formal systems, there are additional systems that are rather stand-alone and not included in the IT management tasks. These so-called ‘shadow systems’ also support business processes but hinder a high enterprise integration. Shadow systems appear during their explicit detection or during software maintenance projects such as enhancements or release changes of enterprise systems. Organizations then have to decide if and to what extent they integrate the identified shadow systems into their ERP systems. For this decision, organizations have to compare the capabilities of each identified shadow system with their ERP systems. Based on multiple-case studies, we provide a dependency approach to enable their comparison. We derive categories for different stages of the dependency and base insights into integration possibilities on these stages. Our results show that 64% of the shadow systems in our case studies are related to ERP systems. This means that they share parts or all of their data and/or functionality with the ERP system. Our research contributes to the field of integration as well as to the discussion about shadow systems.

  6. A coordinate-independent characterization of a black-hole shadow

    CERN Document Server

    Abdujabbarov, A A; Ahmedov, B J

    2015-01-01

    A large international effort is under way to assess the presence of a shadow in the radio emission from the compact source at the center of our galaxy, Sagittarius A$^*$ (Sgr A$^*$). If detected, this shadow would provide the first direct evidence of the existence of black holes and that Sgr A$^*$ is a supermassive black hole. In addition, the shape of the shadow could be used to learn about extreme gravity near the event horizon and to determine which theory of gravity better describes the observations. The mathematical description of the shadow has so far used a number of simplifying assumptions that are unlikely to be met by the real observational data. We here provide a general formalism to describe the shadow as an arbitrary polar curve expressed in terms of a Legendre expansion. Our formalism does not presume any knowledge of the properties of the shadow, e.g., the location of its center, and offers a number of routes to characterize the distortions of the curve with respect to reference circles. These ...

  7. Impact of ground mover motion and windowing on stationary and moving shadows in synthetic aperture radar imagery

    Science.gov (United States)

    Miller, J.; Bishop, E.; Doerry, A.; Raynal, A. M.

    2015-05-01

    This paper describes the impact of ground mover motion and windowing on stationary and moving shadows in Synthetic Aperture Radar (SAR) and video SAR mode imagery. The technique provides a foundation for optimizing algorithms that detect ground movers in SAR imagery. The video SAR mode provides a persistent view of a scene centered at the Motion Compensation Point (MCP). The radar platform follows a circular flight path. Detecting a stationary shadow in a SAR image is important because the shadow indicates a detection of an object with a height component near the shadow. Similarly, the detection of a shadow that moves from frame to frame indicates the detection of a ground mover at the location of the moving shadow. An approach analyzes the impact of windowing in calculating the brightness of a pixel in a stationary, finite-sized shadow region. An extension of the approach describes the pixel brightness for a moving shadow as a function of its velocity. The pixel brightness provides an upper bound on the Probability of Detection (PD) and a lower bound on the Probability of False Alarm (PFA) for a finite-sized, stationary or moving shadow in the presence of homogeneous, ideal clutter. Synthetic data provides shadow characteristics for a radar scenario that lend themselves for detecting a ground mover. The paper presents 2011-2014 flight data collected by General Atomics Aeronautical Systems, Inc. (GA-ASI).

  8. 车路协同系统仿真信息多分辨率交互方法%Multi-resolution Information Exchange Method in Cooperation Vehicle-Infrastructure System

    Institute of Scientific and Technical Information of China (English)

    李四辉; 蔡伯根; 上官伟; 郭科研; 刘宇

    2014-01-01

    车路协同系统仿真研究对于交通系统的发展具有重要的意义。为了研究车路协同系统的仿真关键技术并构建车路协同系统仿真平台,本文提出信息多分辨率交互方法解决基于HLA的系统仿真过程中的网络拥塞问题,建立了高分辨率车辆行驶状态信息模型、中分辨率车队状态信息模型、低分辨率交通流信息模型,运用聚合解聚法实现不同信息分辨率间的仿真过程,采用模糊预测发送缓冲区信息排队长度方法确定多分辨率模型间的聚合解聚时机。通过仿真管理器联邦成员的运行结果分析表明,该方法能够有效减少系统属性吞吐量,从而较好控制网络拥塞,降低系统属性延时,提高仿真效率。%Research of cooperation vehicle-infrastructure system (CVIS) is a great significance for the transportation system development. In order to study the CVIS simulation’s key technology and build up the simulation platform, multi-resolution information interaction method is presented to solve the network congestion problems based on HLA when simulation, a high-resolution information model of vehicle running state, a middle-resolution information model of fleet status and a-low resolution model of traffic flow are established. The simulation of multi-resolution information interaction is achieved by aggregation and disaggregation method, while the time of aggregation and disaggregation determined by queue length of buffer which transmitted from fuzzy prediction. The analysis shows that the method can effectively reduce the system properties throughput by the results of the simulation manager federate, so as to better control network congestion and decline the delay of system properties, it can also improve the CVIS simulation efficiency.

  9. Detecting salient objects based on spectral residual and multi-resolution%基于谱残差和多分辨率分析的显著目标检测

    Institute of Scientific and Technical Information of China (English)

    刘娟妮; 彭进业; 李大湘; 王平

    2011-01-01

    According to the characteristics of human visual system, a salient object detection method based on spectral residual and multi-resolution is proposed.We first compute the spectral residual of three features i.e.intensity, color and orientation under different scales to build a series of multi-resolution saliency maps, which can be combined through linear interpolation to generate three feature-saliency maps.Then we use k-means clustering for binary clustering and select the feature-saliency map with the largest distance between two centroids.Finally we apply dynamic threshold segmentation to get salient regions in an image.The experimental results on natural images show that the new algorithm is stable and practical, and we achieve satisfied results.%根据人类视觉系统的特点,提出一种融合谱残差和多分辨率分析的显著目标检测方法.该方法通过在不同尺度上计算图像的亮度、颜色以及方向特征的谱残差,构建多分辨率显著性图谱序列,然后用线性插值方法将不同分辨率的特征显著图叠加得到3个特征显著图,再利用k均值聚类算法将每个特征显著图聚为两类,选择聚类中心距离最大的特征显著图作为最终的显著图,最后经过动态阈值处理获得图像的显著目标区域.基于自然图像的显著目标检测实验结果表明,该方法具有较强的稳定性和实用性,得到较为满意的检测结果.

  10. On distances between phylogenetic trees

    Energy Technology Data Exchange (ETDEWEB)

    DasGupta, B. [Rutgers Univ., Camden, NJ (United States); He, X. [SUNY, Buffalo, NY (United States); Jiang, T. [McMaster Univ., Hamilton, Ontario (Canada)] [and others

    1997-06-01

    Different phylogenetic trees for the same group of species are often produced either by procedures that use diverse optimality criteria or from different genes in the study of molecular evolution. Comparing these trees to find their similarities and dissimilarities, i.e. distance, is thus an important issue in computational molecular biology. The nearest neighbor interchange distance and the subtree-transfer distance are two major distance metrics that have been proposed and extensively studied for different reasons. Despite their many appealing aspects such as simplicity and sensitivity to tree topologies, computing these distances has remained very challenging. This article studies the complexity and efficient approximation algorithms for computing the nni distance and a natural extension of the subtree-transfer distance, called the linear-cost subtree-transfer distance. The linear-cost subtree-transfer model is more logical than the subtree-transfer model and in fact coincides with the nni model under certain conditions. The following results have been obtained as part of our project of building a comprehensive software package for computing distances between phylogenies. (1) Computing the nni distance is NP-complete. This solves a 25 year old open question appearing again and again in, for example, under the complexity-theoretic assumption of P {ne} NP. We also answer an open question regarding the nni distance between unlabeled trees for which an erroneous proof appeared in. We give an algorithm to compute the optimal nni sequence in time O(n{sup 2} logn + n {circ} 2{sup O(d)}), where the nni distance is at most d. (2) Biological applications require us to extend the nni and linear-cost subtree-transfer models to weighted phylogenies, where edge weights indicate the length of evolution along each edge. We present a logarithmic ratio approximation algorithm for nni and a ratio 2 approximation algorithm for linear-cost subtree-transfer, on weighted trees.

  11. Molecular Phylogenetics: Mathematical Framework and Unsolved Problems

    Science.gov (United States)

    Xia, Xuhua

    Phylogenetic relationship is essential in dating evolutionary events, reconstructing ancestral genes, predicting sites that are important to natural selection, and, ultimately, understanding genomic evolution. Three categories of phylogenetic methods are currently used: the distance-based, the maximum parsimony, and the maximum likelihood method. Here, I present the mathematical framework of these methods and their rationales, provide computational details for each of them, illustrate analytically and numerically the potential biases inherent in these methods, and outline computational challenges and unresolved problems. This is followed by a brief discussion of the Bayesian approach that has been recently used in molecular phylogenetics.

  12. On Tree-Based Phylogenetic Networks.

    Science.gov (United States)

    Zhang, Louxin

    2016-07-01

    A large class of phylogenetic networks can be obtained from trees by the addition of horizontal edges between the tree edges. These networks are called tree-based networks. We present a simple necessary and sufficient condition for tree-based networks and prove that a universal tree-based network exists for any number of taxa that contains as its base every phylogenetic tree on the same set of taxa. This answers two problems posted by Francis and Steel recently. A byproduct is a computer program for generating random binary phylogenetic networks under the uniform distribution model.

  13. Mother-Blaming in the Shadow of Incest: Commentary on "Motherhood in the Shadow of Incest" by Rachel Lev-Wiesel

    Science.gov (United States)

    Faller, Kathleen Coulborn

    2007-01-01

    This commentary on "Motherhood in the Shadow of Incest" by Rachel Lev-Wiesel, is divided into three sections. In the first section, this author addresses the issue of the role of mothers in incest. Faller contends that, with regard to research findings on the role of mothers' own sexual victimization in her child's experience, previous research…

  14. The disentangling number for phylogenetic mixtures

    CERN Document Server

    Sullivant, Seth

    2011-01-01

    We provide a logarithmic upper bound for the disentangling number on unordered lists of leaf labeled trees. This results is useful for analyzing phylogenetic mixture models. The proof depends on interpreting multisets of trees as high dimensional contingency tables.

  15. Advances in phylogenetic studies of Nematoda

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    Nematoda is a metazoan group with extremely high diversity only next to Insecta. Caenorhabditis elegans is now a favorable experimental model animal in modern developmental biology, genetics and genomics studies. However, the phylogeny of Nematoda and the phylogenetic position of the phylum within animal kingdom have long been in debate. Recent molecular phylogenetic studies gave great challenges to the traditional nematode classification. The new phylogenies not only placed the Nematoda in the Ecdysozoan and divided the phylum into five clades, but also provided new insights into animal molecular identification and phylogenetic biodiversity studies. The present paper reviews major progress and remaining problems in the current molecular phylogenetic studies of Nematoda, and prospects the developmental tendencies of this field.

  16. Anticipated Electrical Environment Within Permanently Shadowed Lunar Craters

    Science.gov (United States)

    Farrell, W. M.; Stubbs, T. J.; Halekas, J. S.; Killen, R. M.; Delory, G. T.; Collier, M. R.; Vondrak, R. R.

    2010-01-01

    Shadowed locations ncar the lunar poles arc almost certainly electrically complex regions. At these locations near the terminator, the local solar wind flows nearly tangential to the surface and interacts with large-scale topographic features such as mountains and deep large craters, In this work, we study the solar wind orographic effects from topographic obstructions along a rough lunar surface, On the leeward side of large obstructions, plasma voids are formed in the solar wind because of the absorption of plasma on the upstream surface of these obstacles, Solar wind plasma expands into such voids) producing an ambipolar potential that diverts ion flow into the void region. A surface potential is established on these leeward surfaces in order to balance the currents from the expansion-limited electron and ion populations, Wc find that there arc regions ncar the leeward wall of the craters and leeward mountain faces where solar wind ions cannot access the surface, leaving an electron-rich plasma previously identified as an "electron cloud." In this case, some new current is required to complete the closure for current balance at the surface, and we propose herein that lofted negatively charged dust is one possible (nonunique) compensating current source. Given models for both ambipolar and surface plasma processes, we consider the electrical environment around the large topographic features of the south pole (including Shoemaker crater and the highly varied terrain near Nobile crater), as derived from Goldstone radar data, We also apply our model to moving and stationary objects of differing compositions located on the surface and consider the impact of the deflected ion flow on possible hydrogen resources within the craters

  17. Investigating shadows: a pedagogical intervention project with primary school children

    Science.gov (United States)

    Noversa, Silvana; Abreu, Cátia; Varela, Paulo; Costa, Manuel F. M.

    2014-07-01

    This communication results from a pedagogical intervention project, carried out at a primary school in the district of Braga - Portugal. The intervention took place in a class of the 3rd year, composed of 16 students, and it incorporated the practice of inquiry-based science teaching addressing the theme "Light Experiments", which is part of the "Environmental Studies" curricular area. Various class activities were planned and implemented concerning some of the factors that influence the shadow of an object, in order to find answers to the following three questions: a) will 3rd year students, aged 7/8 years, be able to construct and execute an investigation strategy that involves manipulating and controlling variables? b) what are the main difficulties experienced by students in the designing and execution of such a strategy? c) how will students, in interaction with the teacher and with their peers, gradually design and execute their investigation strategy in order to respond to the problem formulated? The project adopted an action research methodology. A careful record was kept of the events most relevant to the questions under study in each class. This data was used to prepare the class diaries - descriptive and reflective narratives prepared based on recorded audio and field notes made during participant observation in the context of the classroom. A content analysis of the diaries has identified a few elements that provide answers to the research questions raised. In order to plan and implement a research project with children in the 7/8 years old range require a high level of scaffolding to allow students to gradually build a coherent strategy to tackle the research problem. Teacher's role is crucial. The teacher, by questioning and inducing reasoning and discussion, promotes encourages and regulates the cognitive activity of students. Some level of autonomy should be given to the students in large group collaborative work.

  18. Industrial Ecology and Environmental Lean Management: Lights and Shadows

    Directory of Open Access Journals (Sweden)

    Giuseppe Ioppolo

    2014-09-01

    Full Text Available Current industrial production is driven by increasing globalization, which has led to a steady increase in production volumes and complexity of products aimed at the pursuit of meeting the needs of customers. In this context, one of the main tools in the management of customer value is Lean Manufacturing or Production, though it is considered primarily as a set of tools to reduce the total cost of the resources needed to achieve such needs. This philosophy has recently been enriched in the literature with case studies that link Lean Management (LM with the improvement of environmental sustainability. The consequence is an expansion of the Computer Integrated Manufacturing (CIM; indeed, CIM, currently, combining and integrating the key business functions (e.g., business, engineering, manufacturing, and information management with a view of the life cycle, does not highlight the strategic role of the environmental aspects. In order to deal with the increasingly rapid environmental degradation that is reflected in society, in terms of both economy and quality of life, Industrial Ecology (IE introduced a new paradigm of principles and instruments of analysis and decision support (e.g., Life Cycle Assessment—LCA, Social Life Cycle Assessment -SLCA, Material Flow Account—MFA, etc. that can be considered as the main basis for integrating the environmental aspects in each strategy, design, production, final product, and end of life management, through the re-engineering of processes and activities towards the development of an eco-industrial system. This paper presents the preliminary observations based on a analysis of both theories (LM-IE and provides a possible assessment of the key factors relevant to their integration in a “lean environmental management”, highlighting both positives (lights and possible barriers (shadows.

  19. Charles Darwin, beetles and phylogenetics.

    Science.gov (United States)

    Beutel, Rolf G; Friedrich, Frank; Leschen, Richard A B

    2009-11-01

    changed dramatically. With very large data sets and high throughput sampling, phylogenetic questions can be addressed without prior knowledge of morphological characters. Nevertheless, molecular studies have not lead to the great breakthrough in beetle systematics--yet. Especially the phylogeny of the extremely species rich suborder Polyphaga remains incompletely resolved. Coordinated efforts of molecular workers and of morphologists using innovative techniques may lead to more profound insights in the near future. The final aim is to develop a well-founded phylogeny, which truly reflects the evolution of this immensely species rich group of organisms.

  20. Phylogenetic Distribution of Fungal Sterols

    Science.gov (United States)

    Weete, John D.; Abril, Maritza; Blackwell, Meredith

    2010-01-01

    Background Ergosterol has been considered the “fungal sterol” for almost 125 years; however, additional sterol data superimposed on a recent molecular phylogeny of kingdom Fungi reveals a different and more complex situation. Methodology/Principal Findings The interpretation of sterol distribution data in a modern phylogenetic context indicates that there is a clear trend from cholesterol and other Δ5 sterols in the earliest diverging fungal species to ergosterol in later diverging fungi. There are, however, deviations from this pattern in certain clades. Sterols of the diverse zoosporic and zygosporic forms exhibit structural diversity with cholesterol and 24-ethyl -Δ5 sterols in zoosporic taxa, and 24-methyl sterols in zygosporic fungi. For example, each of the three monophyletic lineages of zygosporic fungi has distinctive major sterols, ergosterol in Mucorales, 22-dihydroergosterol in Dimargaritales, Harpellales, and Kickxellales (DHK clade), and 24-methyl cholesterol in Entomophthorales. Other departures from ergosterol as the dominant sterol include: 24-ethyl cholesterol in Glomeromycota, 24-ethyl cholest-7-enol and 24-ethyl-cholesta-7,24(28)-dienol in rust fungi, brassicasterol in Taphrinales and hypogeous pezizalean species, and cholesterol in Pneumocystis. Conclusions/Significance Five dominant end products of sterol biosynthesis (cholesterol, ergosterol, 24-methyl cholesterol, 24-ethyl cholesterol, brassicasterol), and intermediates in the formation of 24-ethyl cholesterol, are major sterols in 175 species of Fungi. Although most fungi in the most speciose clades have ergosterol as a major sterol, sterols are more varied than currently understood, and their distribution supports certain clades of Fungi in current fungal phylogenies. In addition to the intellectual importance of understanding evolution of sterol synthesis in fungi, there is practical importance because certain antifungal drugs (e.g., azoles) target reactions in the synthesis of

  1. Phylogenetic distribution of fungal sterols.

    Directory of Open Access Journals (Sweden)

    John D Weete

    Full Text Available BACKGROUND: Ergosterol has been considered the "fungal sterol" for almost 125 years; however, additional sterol data superimposed on a recent molecular phylogeny of kingdom Fungi reveals a different and more complex situation. METHODOLOGY/PRINCIPAL FINDINGS: The interpretation of sterol distribution data in a modern phylogenetic context indicates that there is a clear trend from cholesterol and other Delta(5 sterols in the earliest diverging fungal species to ergosterol in later diverging fungi. There are, however, deviations from this pattern in certain clades. Sterols of the diverse zoosporic and zygosporic forms exhibit structural diversity with cholesterol and 24-ethyl -Delta(5 sterols in zoosporic taxa, and 24-methyl sterols in zygosporic fungi. For example, each of the three monophyletic lineages of zygosporic fungi has distinctive major sterols, ergosterol in Mucorales, 22-dihydroergosterol in Dimargaritales, Harpellales, and Kickxellales (DHK clade, and 24-methyl cholesterol in Entomophthorales. Other departures from ergosterol as the dominant sterol include: 24-ethyl cholesterol in Glomeromycota, 24-ethyl cholest-7-enol and 24-ethyl-cholesta-7,24(28-dienol in rust fungi, brassicasterol in Taphrinales and hypogeous pezizalean species, and cholesterol in Pneumocystis. CONCLUSIONS/SIGNIFICANCE: Five dominant end products of sterol biosynthesis (cholesterol, ergosterol, 24-methyl cholesterol, 24-ethyl cholesterol, brassicasterol, and intermediates in the formation of 24-ethyl cholesterol, are major sterols in 175 species of Fungi. Although most fungi in the most speciose clades have ergosterol as a major sterol, sterols are more varied than currently understood, and their distribution supports certain clades of Fungi in current fungal phylogenies. In addition to the intellectual importance of understanding evolution of sterol synthesis in fungi, there is practical importance because certain antifungal drugs (e.g., azoles target reactions in

  2. Charles Darwin, beetles and phylogenetics

    Science.gov (United States)

    Beutel, Rolf G.; Friedrich, Frank; Leschen, Richard A. B.

    2009-11-01

    . This has changed dramatically. With very large data sets and high throughput sampling, phylogenetic questions can be addressed without prior knowledge of morphological characters. Nevertheless, molecular studies have not lead to the great breakthrough in beetle systematics—yet. Especially the phylogeny of the extremely species rich suborder Polyphaga remains incompletely resolved. Coordinated efforts of molecular workers and of morphologists using innovative techniques may lead to more profound insights in the near future. The final aim is to develop a well-founded phylogeny, which truly reflects the evolution of this immensely species rich group of organisms.

  3. Phylogenetic approaches to natural product structure prediction.

    Science.gov (United States)

    Ziemert, Nadine; Jensen, Paul R

    2012-01-01

    Phylogenetics is the study of the evolutionary relatedness among groups of organisms. Molecular phylogenetics uses sequence data to infer these relationships for both organisms and the genes they maintain. With the large amount of publicly available sequence data, phylogenetic inference has become increasingly important in all fields of biology. In the case of natural product research, phylogenetic relationships are proving to be highly informative in terms of delineating the architecture and function of the genes involved in secondary metabolite biosynthesis. Polyketide synthases and nonribosomal peptide synthetases provide model examples in which individual domain phylogenies display different predictive capacities, resolving features ranging from substrate specificity to structural motifs associated with the final metabolic product. This chapter provides examples in which phylogeny has proven effective in terms of predicting functional or structural aspects of secondary metabolism. The basics of how to build a reliable phylogenetic tree are explained along with information about programs and tools that can be used for this purpose. Furthermore, it introduces the Natural Product Domain Seeker, a recently developed Web tool that employs phylogenetic logic to classify ketosynthase and condensation domains based on established enzyme architecture and biochemical function.

  4. A practical guide to phylogenetics for nonexperts.

    Science.gov (United States)

    O'Halloran, Damien

    2014-02-05

    Many researchers, across incredibly diverse foci, are applying phylogenetics to their research question(s). However, many researchers are new to this topic and so it presents inherent problems. Here we compile a practical introduction to phylogenetics for nonexperts. We outline in a step-by-step manner, a pipeline for generating reliable phylogenies from gene sequence datasets. We begin with a user-guide for similarity search tools via online interfaces as well as local executables. Next, we explore programs for generating multiple sequence alignments followed by protocols for using software to determine best-fit models of evolution. We then outline protocols for reconstructing phylogenetic relationships via maximum likelihood and Bayesian criteria and finally describe tools for visualizing phylogenetic trees. While this is not by any means an exhaustive description of phylogenetic approaches, it does provide the reader with practical starting information on key software applications commonly utilized by phylogeneticists. The vision for this article would be that it could serve as a practical training tool for researchers embarking on phylogenetic studies and also serve as an educational resource that could be incorporated into a classroom or teaching-lab.

  5. Maximizing the phylogenetic diversity of seed banks.

    Science.gov (United States)

    Griffiths, Kate E; Balding, Sharon T; Dickie, John B; Lewis, Gwilym P; Pearce, Tim R; Grenyer, Richard

    2015-04-01

    Ex situ conservation efforts such as those of zoos, botanical gardens, and seed banks will form a vital complement to in situ conservation actions over the coming decades. It is therefore necessary to pay the same attention to the biological diversity represented in ex situ conservation facilities as is often paid to protected-area networks. Building the phylogenetic diversity of ex situ collections will strengthen our capacity to respond to biodiversity loss. Since 2000, the Millennium Seed Bank Partnership has banked seed from 14% of the world's plant species. We assessed the taxonomic, geographic, and phylogenetic diversity of the Millennium Seed Bank collection of legumes (Leguminosae). We compared the collection with all known legume genera, their known geographic range (at country and regional levels), and a genus-level phylogeny of the legume family constructed for this study. Over half the phylogenetic diversity of legumes at the genus level was represented in the Millennium Seed Bank. However, pragmatic prioritization of species of economic importance and endangerment has led to the banking of a less-than-optimal phylogenetic diversity and prioritization of range-restricted species risks an underdispersed collection. The current state of the phylogenetic diversity of legumes in the Millennium Seed Bank could be substantially improved through the strategic banking of relatively few additional taxa. Our method draws on tools that are widely applied to in situ conservation planning, and it can be used to evaluate and improve the phylogenetic diversity of ex situ collections. © 2014 Society for Conservation Biology.

  6. How does cognition evolve? Phylogenetic comparative psychology

    Science.gov (United States)

    Matthews, Luke J.; Hare, Brian A.; Nunn, Charles L.; Anderson, Rindy C.; Aureli, Filippo; Brannon, Elizabeth M.; Call, Josep; Drea, Christine M.; Emery, Nathan J.; Haun, Daniel B. M.; Herrmann, Esther; Jacobs, Lucia F.; Platt, Michael L.; Rosati, Alexandra G.; Sandel, Aaron A.; Schroepfer, Kara K.; Seed, Amanda M.; Tan, Jingzhi; van Schaik, Carel P.; Wobber, Victoria

    2014-01-01

    Now more than ever animal studies have the potential to test hypotheses regarding how cognition evolves. Comparative psychologists have developed new techniques to probe the cognitive mechanisms underlying animal behavior, and they have become increasingly skillful at adapting methodologies to test multiple species. Meanwhile, evolutionary biologists have generated quantitative approaches to investigate the phylogenetic distribution and function of phenotypic traits, including cognition. In particular, phylogenetic methods can quantitatively (1) test whether specific cognitive abilities are correlated with life history (e.g., lifespan), morphology (e.g., brain size), or socio-ecological variables (e.g., social system), (2) measure how strongly phylogenetic relatedness predicts the distribution of cognitive skills across species, and (3) estimate the ancestral state of a given cognitive trait using measures of cognitive performance from extant species. Phylogenetic methods can also be used to guide the selection of species comparisons that offer the strongest tests of a priori predictions of cognitive evolutionary hypotheses (i.e., phylogenetic targeting). Here, we explain how an integration of comparative psychology and evolutionary biology will answer a host of questions regarding the phylogenetic distribution and history of cognitive traits, as well as the evolutionary processes that drove their evolution. PMID:21927850

  7. How does cognition evolve? Phylogenetic comparative psychology.

    Science.gov (United States)

    MacLean, Evan L; Matthews, Luke J; Hare, Brian A; Nunn, Charles L; Anderson, Rindy C; Aureli, Filippo; Brannon, Elizabeth M; Call, Josep; Drea, Christine M; Emery, Nathan J; Haun, Daniel B M; Herrmann, Esther; Jacobs, Lucia F; Platt, Michael L; Rosati, Alexandra G; Sandel, Aaron A; Schroepfer, Kara K; Seed, Amanda M; Tan, Jingzhi; van Schaik, Carel P; Wobber, Victoria

    2012-03-01

    Now more than ever animal studies have the potential to test hypotheses regarding how cognition evolves. Comparative psychologists have developed new techniques to probe the cognitive mechanisms underlying animal behavior, and they have become increasingly skillful at adapting methodologies to test multiple species. Meanwhile, evolutionary biologists have generated quantitative approaches to investigate the phylogenetic distribution and function of phenotypic traits, including cognition. In particular, phylogenetic methods can quantitatively (1) test whether specific cognitive abilities are correlated with life history (e.g., lifespan), morphology (e.g., brain size), or socio-ecological variables (e.g., social system), (2) measure how strongly phylogenetic relatedness predicts the distribution of cognitive skills across species, and (3) estimate the ancestral state of a given cognitive trait using measures of cognitive performance from extant species. Phylogenetic methods can also be used to guide the selection of species comparisons that offer the strongest tests of a priori predictions of cognitive evolutionary hypotheses (i.e., phylogenetic targeting). Here, we explain how an integration of comparative psychology and evolutionary biology will answer a host of questions regarding the phylogenetic distribution and history of cognitive traits, as well as the evolutionary processes that drove their evolution.

  8. Nodal distances for rooted phylogenetic trees.

    Science.gov (United States)

    Cardona, Gabriel; Llabrés, Mercè; Rosselló, Francesc; Valiente, Gabriel

    2010-08-01

    Dissimilarity measures for (possibly weighted) phylogenetic trees based on the comparison of their vectors of path lengths between pairs of taxa, have been present in the systematics literature since the early seventies. For rooted phylogenetic trees, however, these vectors can only separate non-weighted binary trees, and therefore these dissimilarity measures are metrics only on this class of rooted phylogenetic trees. In this paper we overcome this problem, by splitting in a suitable way each path length between two taxa into two lengths. We prove that the resulting splitted path lengths matrices single out arbitrary rooted phylogenetic trees with nested taxa and arcs weighted in the set of positive real numbers. This allows the definition of metrics on this general class of rooted phylogenetic trees by comparing these matrices through metrics in spaces M(n)(R) of real-valued n x n matrices. We conclude this paper by establishing some basic facts about the metrics for non-weighted phylogenetic trees defined in this way using L(p) metrics on M(n)(R), with p [epsilon] R(>0).

  9. Lost in Jupiter's Shadow: Can Resonant Charge Variations Explain Dust Grain Sizes in the Main Ring?

    Science.gov (United States)

    Jontof-Hutter, Daniel; Hamilton, D. P.

    2012-10-01

    Interplanetary impacts onto the tiny moons Metis and Adrastea replenish Jupiter's main ring with dusty ejecta of all sizes. The equilibrium size distribution present in the rings at a given time is a function of production and loss mechanisms, both of which may be vary with particle size. Loss mechanisms include collisions and dynamical processes. Here we explore some of the latter. Grains tend to pick up negative electric charges due to motion through Jupiter's plasma environment, and positive charges from the photoelectric effect of sunlight. The periodic interruption of sunlight in Jupiter's shadow causes the equilibrium electric charge, and hence the Lorentz force, to resonate with the Kepler orbital frequency. The eccentricity increases for grains moving radially inwards during the shadow transit, and decreases when grains move outward in the shadow, hence the azimuthal location of pericenter is important. For smaller grains, the eccentricity increases monotonically until they collide with Jupiter. For much larger grains, precession due to both the Lorentz force and planetary oblateness causes the eccentricity to oscillate periodically. We explore the shadow instability in the main ring for a variety of uniform plasma density models, comparing numerical data with a semi-analytic approximation. We find that the effect of the shadow dwindles in importance for plasma that is either too sparse or too dense. In sparse plasma, the charging timescale slows, limiting the change in electric potential from sunlight to shadow. In dense plasma, charging currents from the plasma overwhelm the photoelectric effect in sunlight, also resulting in a small change in electric potential. Between these two regimes, the shadow resonance efficiently removes grains up to a particular size threshold in the main ring. This size-dependent loss mechanism may contribute to the observed flattening in the size distribution index for smaller grains.

  10. A Method of Survey on Object-Oriented Shadow Detection & Removal for High Resolution Urban Aerial Colour Images

    OpenAIRE

    A.Amareswar Kumar,; B Mohan Reddy

    2015-01-01

    High-resolution remote sensing images offer great possibilities for urban mapping. Unfortunately, shadows cast by buildings during this some problems occurred .This paper mainly focus to get the high resolution colour remote sensing image, and also undertaken to remove the shaded region in the both urban and rural areas. The region growing thresholding algorithm is used to detect the shadow and extract the features from shadow region. Then determine whether those neighbouring pixe...

  11. Advanced dexterous manipulation for IED defeat : report on the feasibility of using the ShadowHand for remote operations.

    Energy Technology Data Exchange (ETDEWEB)

    Anderson, Robert J.

    2011-01-01

    Improvised Explosive Device (IED) defeat (IEDD) operations can involve intricate operations that exceed the current capabilities of the grippers on board current bombsquad robots. The Shadow Dexterous Hand from the Shadow Robot Company or 'ShadowHand' for short (www.shadowrobot.com) is the first commercially available robot hand that realistically replicates the motion, degrees-of-freedom and dimensions of a human hand (Figure 1). In this study we evaluate the potential for the ShadowHand to perform potential IED defeat tasks on a mobile platform.

  12. Analysis of shadowing effects on MIR photovoltaic and solar dynamic power systems

    Science.gov (United States)

    Fincannon, James

    1995-01-01

    The NASA Lewis Research Center is currently working with RSC-Energia, the Russian Space Agency, and Allied Signal in developing a flight demonstration solar dynamic power system. This type of power system is dependent upon solar flux that is reflected and concentrated into a thermal storage system to provide the thermal energy input to a closed-cycle Brayton heat engine. The solar dynamic unit will be flown on the Russian Mir space station in anticipation of use on the International Space Station Alpha. By the time the power system is launched, the Mir will be a spatially complex configuration which will have, in addition to the three-gimbaled solar dynamic unit, eleven solar array wings that are either fixed or track the Sun along one axis and a variety or repositionable habitation and experiment modules. The proximity of arrays to modules creates a situation which makes it highly probable that there will be varying solar flux due to shadowing on the solar dynamic unit and some of the arrays throughout the orbit. Shadowing causes fluctuations in the power output from the arrays and the solar dynamic power system, thus reducing the energy capabilities of the spacecraft. An assessment of the capabilities of the power system under these conditions is an important part in influencing the design and operations of the spacecraft and predicting its energy performance. This paper describes the results obtained from using the Orbiting Spacecraft Shadowing Analysis Station program that was integrated into the Station Power Analysis for Capability Evaluation (SPACE) electrical power system computer program. OSSA allows one to consider the numerous complex factors for analyzing the shadowing effects on the electrical power system including the variety of spacecraft hardware geometric configurations, yearly and daily orbital variations in the vehicle attitude and orbital maneuvers (for communications coverage, payload pointing requirements and rendezvous/docking with other

  13. Automated vessel shadow segmentation of fovea-centered spectral-domain images from multiple OCT devices

    Science.gov (United States)

    Wu, Jing; Gerendas, Bianca S.; Waldstein, Sebastian M.; Simader, Christian; Schmidt-Erfurth, Ursula

    2014-03-01

    Spectral-domain Optical Coherence Tomography (SD-OCT) is a non-invasive modality for acquiring high reso- lution, three-dimensional (3D) cross sectional volumetric images of the retina and the subretinal layers. SD-OCT also allows the detailed imaging of retinal pathology, aiding clinicians in the diagnosis of sight degrading diseases such as age-related macular degeneration (AMD) and glaucoma.1 Disease diagnosis, assessment, and treatment requires a patient to undergo multiple OCT scans, possibly using different scanning devices, to accurately and precisely gauge disease activity, progression and treatment success. However, the use of OCT imaging devices from different vendors, combined with patient movement may result in poor scan spatial correlation, potentially leading to incorrect patient diagnosis or treatment analysis. Image registration can be used to precisely compare disease states by registering differing 3D scans to one another. In order to align 3D scans from different time- points and vendors using registration, landmarks are required, the most obvious being the retinal vasculature. Presented here is a fully automated cross-vendor method to acquire retina vessel locations for OCT registration from fovea centred 3D SD-OCT scans based on vessel shadows. Noise filtered OCT scans are flattened based on vendor retinal layer segmentation, to extract the retinal pigment epithelium (RPE) layer of the retina. Voxel based layer profile analysis and k-means clustering is used to extract candidate vessel shadow regions from the RPE layer. In conjunction, the extracted RPE layers are combined to generate a projection image featuring all candidate vessel shadows. Image processing methods for vessel segmentation of the OCT constructed projection image are then applied to optimize the accuracy of OCT vessel shadow segmentation through the removal of false positive shadow regions such as those caused by exudates and cysts. Validation of segmented vessel shadows uses

  14. Shadows of CPR black holes and tests of the Kerr metric

    Energy Technology Data Exchange (ETDEWEB)

    Ghasemi-Nodehi, M.; Li, Zilong; Bambi, Cosimo [Fudan University, Department of Physics, Center for Field Theory and Particle Physics, Shanghai (China)

    2015-07-15

    Ww study the shadow of the Cardoso-Pani-Rico black hole for different values of the black hole spin a{sub *}, the deformation parameters ε{sub 3}{sup t} and ε{sub 3}{sup r}, and the viewing angle i. We find that the main impact of the deformation parameter ε{sub 3}{sup t} is the change of the size of the shadow, while the deformation parameter ε{sub 3}{sup r} affects the shape of its boundary. In general, it is impossible to test the Kerr metric, because the shadow of a Kerr black hole can be reproduced quite well by a black hole with non-vanishing ε{sub 3}{sup t} or ε{sub 3}{sup r}. Deviations from the Kerr geometry could be constrained in the presence of high quality data and in the favorable case of a black hole with high values of a{sub *} and i. However, the shadows of some black holes with non-vanishing ε{sub 3}{sup r} present peculiar features and the possible detection of these shadows could unambiguously distinguish these objects from the standard Kerr black holes of general relativity. (orig.)

  15. The Shadow Economy of Czech Republic and Tax Evasion: The Currency Demand Approach

    Directory of Open Access Journals (Sweden)

    Dennis Nchor

    2016-01-01

    Full Text Available This study investigates the shadow economy of Czech Republic and the associated losses in tax revenue. The presence of a shadow economy may not necessarily be bad for the economies in which they prevail but they could cause huge losses to government revenue and could also constitute serious violation of labour regulations. The study uses the Currency Demand Approach. It measures the size of the shadow economy in two stages: a the econometric estimation of an aggregate money demand equation b the calculation of the value of the shadow economy through the quantity theory of money. The key variables in the study include: the total currency held outside the banking system, the number of automatic teller machines, the deposit interest rate, GDP deflator, the average tax, velocity of money, nominal GDP and nominal money supply. The results from the study show that the shadow economy of Czech Republic on the average is about 20.9 % as at the end of 2013 and the country loses an average tax revenue of about 7.2 % of GDP yearly. The data was obtained from the World Bank country indicators and the International Financial Statistics.

  16. Observation of the Cosmic Ray Moon shadowing effect with the ARGO-YBJ experiment

    CERN Document Server

    Di Sciascio, G

    2011-01-01

    Cosmic rays are hampered by the Moon and a deficit in its direction is expected (the so-called \\emph{Moon shadow}). The Moon shadow is an important tool to determine the performance of an air shower array. In fact, the displacement of the shadow center, due to the bending effect of the Geomagnetic field on the propagation of cosmic rays, allows to set the energy scale of the primary particles inducing the showers observed by the detector. The shape of the shadow permits to determine the detector point spread function. The position of the deficit at high energy allows evaluating its pointing accuracy. Here we present the observation of the cosmic ray Moon shadowing effect carried out by the ARGO-YBJ experiment (Yangbajing Cosmic Ray Laboratory, Tibet, P.R. China, 4300 m a.s.l., 606 g/cm$^2$) in the multi-TeV energy region with high statistical significance (70 standard deviations). By means of an accurate Monte Carlo simulation of the cosmic rays propagation in the Earth-Moon system we have studied the role of...

  17. A method for image-based shadow interaction with virtual objects

    Directory of Open Access Journals (Sweden)

    Hyunwoo Ha

    2015-01-01

    Full Text Available A lot of researchers have been investigating interactive portable projection systems such as a mini-projector. In addition, in exhibition halls and museums, there is a trend toward using interactive projection systems to make viewing more exciting and impressive. They can also be applied in the field of art, for example, in creating shadow plays. The key idea of the interactive portable projection systems is to recognize the user׳s gesture in real-time. In this paper, a vision-based shadow gesture recognition method is proposed for interactive projection systems. The gesture recognition method is based on the screen image obtained by a single web camera. The method separates only the shadow area by combining the binary image with an input image using a learning algorithm that isolates the background from the input image. The region of interest is recognized with labeling the shadow of separated regions, and then hand shadows are isolated using the defect, convex hull, and moment of each region. To distinguish hand gestures, Hu׳s invariant moment method is used. An optical flow algorithm is used for tracking the fingertip. Using this method, a few interactive applications are developed, which are presented in this paper.

  18. Shadows of CPR black holes and tests of the Kerr metric

    CERN Document Server

    Ghasemi-Nodehi, Masoumeh; Bambi, Cosimo

    2015-01-01

    We study the shadow of the Cardoso-Pani-Rico (CPR) black hole for different values of the black hole spin $a_*$, the deformation parameters $\\epsilon_3^t$ and $\\epsilon_3^r$, and the viewing angle $i$. We find that the main impact of the deformation parameter $\\epsilon_3^t$ is the change of the size of the shadow, while the deformation parameter $\\epsilon_3^r$ affects the shape of its boundary. In general, it is impossible to test the Kerr metric, because the shadow of a Kerr black hole can be reproduced quite well by a black hole with non-vanishing $\\epsilon_3^t$ or $\\epsilon_3^r$. Deviations from the Kerr geometry could be constrained in the presence of high quality data and in the favorable case of a black hole with high values of $a_*$ and $i$. However, the shadows of some black holes with non-vanishing $\\epsilon_3^r$ present peculiar features and the possible detection of these shadows could unambiguously distinguish these objects from the standard Kerr black holes of general relativity.

  19. A DYNAMIC APPROACH TO CALCULATE SHADOW PRICES OF WATER RESOURCES FOR NINE MAJOR RIVERS IN CHINA

    Institute of Scientific and Technical Information of China (English)

    Jing HE; Xikang CHEN; Yong SHI

    2006-01-01

    China is experiencing from serious water issues. There are many differences among the Nine Major Rivers basins of China in the construction of dikes, reservoirs, floodgates, flood discharge projects, flood diversion projects, water ecological construction, water conservancy management, etc.The shadow prices of water resources for Nine Major Rivers can provide suggestions to the Chinese government. This article develops a dynamic shadow prices approach based on a multiperiod input-output optimizing model. Unlike previous approaches, the new model is based on the dynamic computable general equilibrium (DCGE) model to solve the problem of marginal long-term prices of water resources.First, definitions and algorithms of DCGE are elaborated. Second, the results of shadow prices of water resources for Nine Major Rivers in 1949-2050 in China using the National Water Conservancy input-holding-output table for Nine Major Rivers in 1999 are listed. A conclusion of this article is that the shadow prices of water resources for Nine Major Rivers are largely based on the extent of scarcity.Selling prices of water resources should be revised via the usage of parameters representing shadow prices.

  20. Shadow detection in camera-based vehicle detection: survey and analysis

    Science.gov (United States)

    Barcellos, Pablo; Gomes, Vitor; Scharcanski, Jacob

    2016-09-01

    The number of vehicles in circulation in modern urban centers has greatly increased, which motivates the development of automatic traffic monitoring systems. Consequently, camera-based traffic monitoring systems are becoming more widely used, since they offer important technological advantages in comparison with traditional traffic monitoring systems (e.g., simpler maintenance and more flexibility for the design of practical configurations). The segmentation of the foreground (i.e., vehicles) is a fundamental step in the workflow of a camera-based traffic monitoring system. However, foreground segmentation can be negatively affected by vehicle shadows. This paper discusses the types of shadow detection methods available in the literature, their advantages, disadvantages, and in which situations these methods can improve camera-based vehicle detection for traffic monitoring. In order to compare the performance of these different types of shadow detection methods, experiments are conducted with typical methods of each category using publicly available datasets. This work shows that shadow detection definitely can improve the reliability of traffic monitoring systems, but the choice of the type of shadow method depends on the system specifications (e.g., tolerated error), the availability of computational resources, and prior information about the scene and its illumination in regular operation conditions.