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/

Shadow photography method for beam emittance measurement

International Nuclear Information System (INIS)

Kashkovskij, V.V.; Lisin, V.A.

1988-01-01

Improved technique of shadow photography which allows to measure rather simply and accurately the angular distribution of electrons extracted from betatron is described. Measurement accuracy of particle flight angles is determined by setting of rods relatively to the plane of photographic paper sheet, their diameter and shadow trace length. Incidental angle deviation of rod axes contributes mainly into the error. Mean root-square error constituted 2-3% according to the results of several measurements of angles

Shadow detection of moving objects based on multisource information in Internet of things

Science.gov (United States)

Ma, Zhen; Zhang, De-gan; Chen, Jie; Hou, Yue-xian

2017-05-01

Moving object detection is an important part in intelligent video surveillance under the banner of Internet of things. The detection of moving target's shadow is also an important step in moving object detection. On the accuracy of shadow detection will affect the detection results of the object directly. Based on the variety of shadow detection method, we find that only using one feature can't make the result of detection accurately. Then we present a new method for shadow detection which contains colour information, the invariance of optical and texture feature. Through the comprehensive analysis of the detecting results of three kinds of information, the shadow was effectively determined. It gets ideal effect in the experiment when combining advantages of various methods.

Building Shadow Detection from Ghost Imagery

Science.gov (United States)

Zhou, G.; Sha, J.; Yue, T.; Wang, Q.; Liu, X.; Huang, S.; Pan, Q.; Wei, J.

2018-05-01

Shadow is one of the basic features of remote sensing image, it expresses a lot of information of the object which is loss or interference, and the removal of shadow is always a difficult problem to remote sensing image processing. In this paper, it is mainly analyzes the characteristics and properties of shadows from the ghost image (traditional orthorectification). The DBM and the interior and exterior orientation elements of the image are used to calculate the zenith angle of sun. Then this paper combines the scope of the architectural shadows which has be determined by the zenith angle of sun with the region growing method to make the detection of architectural shadow areas. This method lays a solid foundation for the shadow of the repair from the ghost image later. It will greatly improve the accuracy of shadow detection from buildings and make it more conducive to solve the problem of urban large-scale aerial imagines.

BUILDING SHADOW DETECTION FROM GHOST IMAGERY

Directory of Open Access Journals (Sweden)

G. Zhou

2018-05-01

Full Text Available Shadow is one of the basic features of remote sensing image, it expresses a lot of information of the object which is loss or interference, and the removal of shadow is always a difficult problem to remote sensing image processing. In this paper, it is mainly analyzes the characteristics and properties of shadows from the ghost image (traditional orthorectification. The DBM and the interior and exterior orientation elements of the image are used to calculate the zenith angle of sun. Then this paper combines the scope of the architectural shadows which has be determined by the zenith angle of sun with the region growing method to make the detection of architectural shadow areas. This method lays a solid foundation for the shadow of the repair from the ghost image later. It will greatly improve the accuracy of shadow detection from buildings and make it more conducive to solve the problem of urban large-scale aerial imagines.

FACET, Radiation View Factor with Shadowing

International Nuclear Information System (INIS)

Shapiro, A.B.

1988-01-01

1 - Description of program or function: FACET calculates the radiation geometric view factor (alternatively called shape factor, angle factor, or configuration factor) between surfaces for axisymmetric, two-dimensional planar and three-dimensional geometries with interposed third surface obstructions. FACET was developed to calculate view factors as input data to finite element heat transfer analysis codes. 2 - Method of solution: Three algorithms are incorporated to integrate the view factor equation for three dimensional geometries. The algorithm used for any two surfaces depends on their geometric relationship and whether third surface obstructions exist. The three algorithms are the area integration (AI) method, the line integration method (LI), and the Mitalas and Stephenson (MS) method. The LI method is used to calculate the view factor between two disjoint surfaces. If the two surfaces have an adjoint edge, the MS method is used. The AI method is used if there is self or third surface shadowing. In two-dimensional planar geometries, the view factor between two surfaces is calculated using Hottel's cross string method. For axisymmetric geometries in the absence of shadowing, the view factor between two surfaces is calculated by view factor algebra using the view factors between parallel coaxial discs. In the presence of self or third surface shadowing, the geometry is represented in three dimensions before calculating the view factors

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.

Theory and empiricism of shadow economy - an economic analysis example for Austria

International Nuclear Information System (INIS)

Kuntzer, H.-P.

2000-09-01

Illegally circulating streams of net output will exist as long as economic events are registered and taxed by state authorities. Since the beginning of the eighties this part of the economic process has been more and more involved in scientific and political discussions not least because of the stagnating officially registered domestic content (as a result of two oil crisis) which lead to a continually financial crisis of all social security systems in Europe. Even if the shadow economic domestic content of GDP in Austria can be seen as relatively low in comparison to international figures, the steady increase of this sector during the last few years gives rise to concerns. In order to approach the phenomenon of shadow economy and especially illegal activities in the Alpine republic this treatise gives an abstract on the state of affairs as far as theoretical researches on the shadow economy is concerned. In this connection the following influencing factors are seen as important. On the one hand the variety of costs that go with the factor work (direct and indirect taxes, social security contributions and regulating costs) and on the other hand the steadily rising offers of illegal activities as a result of decreasing working hours and increasing unemployment. Moreover this development is supported by the growing sullenness towards state authorities (hypotheses of changing values). The interplay of all these factors ends up in an increasing share value of shadow economic activities in the OECD. The effects of this circumstance are evaluated ambivalently by theory because there are negative effects (growing unemployment, low tax receipts) as well as positive effects (induced costs, better supply of consumer demands). Punitive measures to control these activities are also regarded as ineffective. In order to approach the shadow economy - especially in Austria - this treatise first deals with the different methods to measure shadow economic activities, which are all

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

The close objects buffer : a sharp shadow detection technique for radiosity methods

NARCIS (Netherlands)

Telea, A.C.; Overveld, van C.W.A.M.

1997-01-01

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

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

Shadow detection and removal in RGB VHR images for land use unsupervised classification

Science.gov (United States)

Movia, A.; Beinat, A.; Crosilla, F.

2016-09-01

Nowadays, high resolution aerial images are widely available thanks to the diffusion of advanced technologies such as UAVs (Unmanned Aerial Vehicles) and new satellite missions. Although these developments offer new opportunities for accurate land use analysis and change detection, cloud and terrain shadows actually limit benefits and possibilities of modern sensors. Focusing on the problem of shadow detection and removal in VHR color images, the paper proposes new solutions and analyses how they can enhance common unsupervised classification procedures for identifying land use classes related to the CO2 absorption. To this aim, an improved fully automatic procedure has been developed for detecting image shadows using exclusively RGB color information, and avoiding user interaction. Results show a significant accuracy enhancement with respect to similar methods using RGB based indexes. Furthermore, novel solutions derived from Procrustes analysis have been applied to remove shadows and restore brightness in the images. In particular, two methods implementing the so called "anisotropic Procrustes" and the "not-centered oblique Procrustes" algorithms have been developed and compared with the linear correlation correction method based on the Cholesky decomposition. To assess how shadow removal can enhance unsupervised classifications, results obtained with classical methods such as k-means, maximum likelihood, and self-organizing maps, have been compared to each other and with a supervised clustering procedure.

Simple Impact Crater Shapes From Shadows - The Sequel

Science.gov (United States)

Chappelow, J. E.

2008-12-01

At the last LPSC meeting I presented the outline of a method for determining simple impact crater shapes from shadows. In theory the shadow cast within a simple crater provides enough information to derive its cross-sectional shape from shadow measurements, at least to the maximum depth to which the shadow extends. Under certain simple assumptions, this can be done analytically. If the crater is conic-section - shaped, then it can be shown that the down-sun bound of any shadow cast within it is elliptical, with one axis along the direction of illumination and the other (perpendicular to it) of semi-length D/2 (where D is diameter). The properties of this shadow-ellipse can be related to the parameters of the crater shape conic-section, thus measurements of the shadow-ellipse yield not only crater depth and diameter but also the approximate crater shape, in terms of conic sections. The method also does not depend upon the shadow crossing near the crater center, which avoids a pitfall of older shadow measurement methods. The technique is also amenable to computer implementation, which has already been largely completed. Once computerized, crater measurements can be made rapidly and repeatably. The program reads in an image, its resolution, and the solar elevation and azimuth. The user then defines the crater rim by 'clicking' on three points, and the shadow ellipse by clicking on two more. The program calculates and outputs the diameter, the depth, and parameters describing the crater's approximating conic-section. It is highly applicable to situations where only single-image photography is available, for example MESSENGER flybys of Mercury. At the meeting I will present the finished math for this method and give some examples of its use.

Optimization of the recoil-shadow projection method for the investigation of short-lived fission isomers

Energy Technology Data Exchange (ETDEWEB)

Helmecke, M.; Thirolf, P.G.; Habs, D.; Gartzke, E.; Kolhinen, V.; Lang, C.; Szerypo, J.; Trepl, L. [Fakultaet f. Physik, LMU Muenchen (Germany); Maier-Leibnitz Laboratory, Garching (Germany)

2009-07-01

Spectroscopic studies of super- and hyperdeformed actinide nuclei offer the possibility to gain insight into the multiple-humped fission barrier landscape. With the identification of deep third minima in {sup 234}U and {sup 236}U the systematics of fission isomers in light actinides was revisited, especially searching for isomers in light uranium isotopes with half-lives in the pico-second range. Using the recoil-shadow projection method and solid state nuclear track detectors, an experimental search for their observation has been started. This well-established detection technique nowadays benefits from an efficient analysis technology based on a PC-controlled auto-focus microscope and a CCD camera together with pattern recognition software. The flatness and the definition of the shadow edge of the target is the critical point of this method: Due to the energy loss of the beam the target carrier foil (1{mu}m Ni) may develop thermal distortions in the {mu}m range, leading to misinterpretations of isomeric fission fragments. Therefore the flatness of the target foil is continuously monitored via a capacitance measurement. First results applying this method to the search of a fission isomer in {sup 234}U via the {sup 232}Th({alpha},2n) reaction are presented.

Cloud-shadow removal for Unmanned Aerial System multispectral imagery based on tensor decomposition methods

DEFF Research Database (Denmark)

Baum, Andreas; Wang, Sheng; Garcia, Monica

2017-01-01

that are mosaicked into larger images to produce ortho-photomaps. Frequently, especially in northern latitudes, the images to be mosaicked have been acquired under varying irradiance conditions due to moving clouds that create artifacts in the detected signal unrelated to physical changes in vegetation properties......, this study succeeded to remove the cloud shadow effects and image noise in UAS imagery providing normalized reflectance. The comparison between the corrected and un-corrected images shows a significant improvement for reflectance estimation in the shadow areas. Further, analysis of vegetation indices e...

An IMU-Aided Body-Shadowing Error Compensation Method for Indoor Bluetooth Positioning.

Science.gov (United States)

Deng, Zhongliang; Fu, Xiao; Wang, Hanhua

2018-01-20

Research on indoor positioning technologies has recently become a hotspot because of the huge social and economic potential of indoor location-based services (ILBS). Wireless positioning signals have a considerable attenuation in received signal strength (RSS) when transmitting through human bodies, which would cause significant ranging and positioning errors in RSS-based systems. This paper mainly focuses on the body-shadowing impairment of RSS-based ranging and positioning, and derives a mathematical expression of the relation between the body-shadowing effect and the positioning error. In addition, an inertial measurement unit-aided (IMU-aided) body-shadowing detection strategy is designed, and an error compensation model is established to mitigate the effect of body-shadowing. A Bluetooth positioning algorithm with body-shadowing error compensation (BP-BEC) is then proposed to improve both the positioning accuracy and the robustness in indoor body-shadowing environments. Experiments are conducted in two indoor test beds, and the performance of both the BP-BEC algorithm and the algorithms without body-shadowing error compensation (named no-BEC) is evaluated. The results show that the BP-BEC outperforms the no-BEC by about 60.1% and 73.6% in terms of positioning accuracy and robustness, respectively. Moreover, the execution time of the BP-BEC algorithm is also evaluated, and results show that the convergence speed of the proposed algorithm has an insignificant effect on real-time localization.

Shadow art

KAUST Repository

Mitra, Niloy J.; Pauly, Mark

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

Shadow effect on photovoltaic potentiality analysis using 3D city models

NARCIS (Netherlands)

Alam, N.; Coors, V.; Zlatanova, S.; Van Oosterom, P.J.M.

2012-01-01

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

An IMU-Aided Body-Shadowing Error Compensation Method for Indoor Bluetooth Positioning

Directory of Open Access Journals (Sweden)

Zhongliang Deng

2018-01-01

Full Text Available Research on indoor positioning technologies has recently become a hotspot because of the huge social and economic potential of indoor location-based services (ILBS. Wireless positioning signals have a considerable attenuation in received signal strength (RSS when transmitting through human bodies, which would cause significant ranging and positioning errors in RSS-based systems. This paper mainly focuses on the body-shadowing impairment of RSS-based ranging and positioning, and derives a mathematical expression of the relation between the body-shadowing effect and the positioning error. In addition, an inertial measurement unit-aided (IMU-aided body-shadowing detection strategy is designed, and an error compensation model is established to mitigate the effect of body-shadowing. A Bluetooth positioning algorithm with body-shadowing error compensation (BP-BEC is then proposed to improve both the positioning accuracy and the robustness in indoor body-shadowing environments. Experiments are conducted in two indoor test beds, and the performance of both the BP-BEC algorithm and the algorithms without body-shadowing error compensation (named no-BEC is evaluated. The results show that the BP-BEC outperforms the no-BEC by about 60.1% and 73.6% in terms of positioning accuracy and robustness, respectively. Moreover, the execution time of the BP-BEC algorithm is also evaluated, and results show that the convergence speed of the proposed algorithm has an insignificant effect on real-time localization.

Near real-time shadow detection and removal in aerial motion imagery application

Science.gov (United States)

Silva, Guilherme F.; Carneiro, Grace B.; Doth, Ricardo; Amaral, Leonardo A.; Azevedo, Dario F. G. de

2018-06-01

This work presents a method to automatically detect and remove shadows in urban aerial images and its application in an aerospace remote monitoring system requiring near real-time processing. Our detection method generates shadow masks and is accelerated by GPU programming. To obtain the shadow masks, we converted images from RGB to CIELCh model, calculated a modified Specthem ratio, and applied multilevel thresholding. Morphological operations were used to reduce shadow mask noise. The shadow masks are used in the process of removing shadows from the original images using the illumination ratio of the shadow/non-shadow regions. We obtained shadow detection accuracy of around 93% and shadow removal results comparable to the state-of-the-art while maintaining execution time under real-time constraints.

An image-space parallel convolution filtering algorithm based on shadow map

Science.gov (United States)

Li, Hua; Yang, Huamin; Zhao, Jianping

2017-07-01

Shadow mapping is commonly used in real-time rendering. In this paper, we presented an accurate and efficient method of soft shadows generation from planar area lights. First this method generated a depth map from light's view, and analyzed the depth-discontinuities areas as well as shadow boundaries. Then these areas were described as binary values in the texture map called binary light-visibility map, and a parallel convolution filtering algorithm based on GPU was enforced to smooth out the boundaries with a box filter. Experiments show that our algorithm is an effective shadow map based method that produces perceptually accurate soft shadows in real time with more details of shadow boundaries compared with the previous works.

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

Interdisciplinary Approach to the Study of Shadow Economy

Directory of Open Access Journals (Sweden)

Elena Aleksandrovna Orekhova

2016-03-01

Full Text Available Currently the institutional factors of economic development are updated. The problem of neutralizing the impact of informal institutions is becoming paramount. In order to develop adequate measures to influence the shadow economy and the development of the concept of anti-shadow policies requires a deep and comprehensive study of the shadow socio-economic processes in Russia. It is necessary to recognize the fact that the methods of struggle against the shadow economy have not yet had the desired effect, that implies the conclusion – the causes of the shadow economy have deep roots and are out of the sphere of economic relations. Shadow economic processes are the result of the behavioral characteristics of people, socio-psychological reasons as a consequence of the low cultural level, marginality, inefficient conjugation of institutions and culture, lack of confidence in the society, the specific characteristics of economic mentality, etc. Therefore, if the causes of the shadow relations are rooted in completely different spheres, then the methods of research should also belong to different sciences. The article considers the methodological possibilities in the study of the Russian shadow economy. The logical sequence of the shadow economy research includes empirical and theoretical stages. The level of the empirical phase of gathering facts about the shadow economy has a number of complexities and peculiarities. On a theoretical level there is necessity of multimethodological approach. The authors proved the usefulness of the methodological system and the results of research in the fields of sociology, psychology, criminology, statistics and mathematics, as well as related to the economy of sciences – economic psychology, behavioral economics, economic teratology, and others. The article proposes to carry out studies of the shadow economy at the different levels of architectonics of the institutional structure of shadow economy: the nano

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.

Numerical method of applying shadow theory to all regions of multilayered dielectric gratings in conical mounting.

Science.gov (United States)

Wakabayashi, Hideaki; Asai, Masamitsu; Matsumoto, Keiji; Yamakita, Jiro

2016-11-01

Nakayama's shadow theory first discussed the diffraction by a perfectly conducting grating in a planar mounting. In the theory, a new formulation by use of a scattering factor was proposed. This paper focuses on the middle regions of a multilayered dielectric grating placed in conical mounting. Applying the shadow theory to the matrix eigenvalues method, we compose new transformation and improved propagation matrices of the shadow theory for conical mounting. Using these matrices and scattering factors, being the basic quantity of diffraction amplitudes, we formulate a new description of three-dimensional scattering fields which is available even for cases where the eigenvalues are degenerate in any region. Some numerical examples are given for cases where the eigenvalues are degenerate in the middle regions.

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....

Syndrome of round shadow

International Nuclear Information System (INIS)

Ginzburg, M.A.; Kinoshenko, Yu.T.

1987-01-01

Syndrome of round shadow is a traditional determination for a group of spherical, ovoid and similar volumetric formations of more than 1 cm. Differential roentgenodiagnosis of most typical diseases presented by a round shadow as well as dynamics of X-ray pattern of some round formations are presented. Radiological signs of the lung formations and similar ones in diaphragm and mediastinum thoracic wall are given. Ethiology, pathogenesis and pathomorphology of round formations, their clinical picture and investigation methods are discussed

Analysis of tumor-like shadows on abdominal plain x-ray film

International Nuclear Information System (INIS)

Hayashi, Hidehiro; Hiraki, Yoshio; Hashimoto, Keizi

1986-01-01

We found tumor-like shadows in the upper abdomen in 93 cases out of 400 abdominal plain films, although none of these 93 cases actually had a tumor. We analyzed these tumor-like shadows by computed tomography. For each of the 400 cases we measured the width of flank stripe on the abdominal plain film. Most of the tumor-like shadows in the left upper abdomen were gastric fundus, but it was significant for evaluating plain abdominal film that other organs such as a part of the left lobe of the liver, the upper pole of the left kidney, and a part of the spleen formed tumor-like shadows. The most important factors forming tumor-like shadows on plain abdominal film are the fat volume of the abdominal cauity as well as the fraciform ligament and alterations in the shape and volume of organs such as occur in liver cirrhosis. (author)

Metal shadowing for electron microscopy.

Science.gov (United States)

Hendricks, Gregory M

2014-01-01

Metal shadowing of bacteria, viruses, isolated molecules, and macromolecular assemblies is another high-resolution method for observing the ultrastructure of biological specimens. The actual procedure for producing a metal shadow is relatively simple; a heavy metal is evaporated from a source at an oblique angle to the specimen. The metal atoms pile up on the surfaces that face the source, but the surfaces away from the source are shielded and receive little metal deposit, creating a "shadow." However, the process of producing biological specimens that are suitable for metal shadowing can be very complex. There are a whole host of specimen preparation techniques that can precede metal shadowing, and all provide superior preservation in comparison to air drying, a required step in negative staining procedures. The physical forces present during air drying (i.e., surface tension of the water-air interface) will literally crush most biological specimens as they dry. In this chapter I explain the development of and procedures for the production of biological specimens from macromolecular assemblies (e.g., DNA and RNA), purified isolated molecules (e.g., proteins), and isolated viruses and bacteria preparations suitable for metal shadowing. A variation on this basic technique is to rotate the specimen during the metal deposition to produce a high-resolution three-dimensional rendering of the specimen.

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.

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...

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...

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.

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...

Shadow algorithms data miner

CERN Document Server

Woo, Andrew

2012-01-01

Digital shadow generation continues to be an important aspect of visualization and visual effects in film, games, simulations, and scientific applications. This resource offers a thorough picture of the motivations, complexities, and categorized algorithms available to generate digital shadows. From general fundamentals to specific applications, it addresses shadow algorithms and how to manage huge data sets from a shadow perspective. The book also examines the use of shadow algorithms in industrial applications, in terms of what algorithms are used and what software is applicable.

Improving Shadow Suppression for Illumination Robust Face Recognition

KAUST Repository

Zhang, Wuming

2017-10-13

2D face analysis techniques, such as face landmarking, face recognition and face verification, are reasonably dependent on illumination conditions which are usually uncontrolled and unpredictable in the real world. An illumination robust preprocessing method thus remains a significant challenge in reliable face analysis. In this paper we propose a novel approach for improving lighting normalization through building the underlying reflectance model which characterizes interactions between skin surface, lighting source and camera sensor, and elaborates the formation of face color appearance. Specifically, the proposed illumination processing pipeline enables the generation of Chromaticity Intrinsic Image (CII) in a log chromaticity space which is robust to illumination variations. Moreover, as an advantage over most prevailing methods, a photo-realistic color face image is subsequently reconstructed which eliminates a wide variety of shadows whilst retaining the color information and identity details. Experimental results under different scenarios and using various face databases show the effectiveness of the proposed approach to deal with lighting variations, including both soft and hard shadows, in face recognition.

Automatic Cloud and Shadow Detection in Optical Satellite Imagery Without Using Thermal Bands—Application to Suomi NPP VIIRS Images over Fennoscandia

Directory of Open Access Journals (Sweden)

Eija Parmes

2017-08-01

Full Text Available In land monitoring applications, clouds and shadows are considered noise that should be removed as automatically and quickly as possible, before further analysis. This paper presents a method to detect clouds and shadows in Suomi NPP satellite’s VIIRS (Visible Infrared Imaging Radiometer Suite satellite images. The proposed cloud and shadow detection method has two distinct features when compared to many other methods. First, the method does not use the thermal bands and can thus be applied to other sensors which do not contain thermal channels, such as Sentinel-2 data. Secondly, the method uses the ratio between blue and green reflectance to detect shadows. Seven hundred and forty-seven VIIRS images over Fennoscandia from August 2014 to April 2016 were processed to train and develop the method. Twenty four points from every tenth of the images were used in accuracy assessment. These 1752 points were interpreted visually to cloud, cloud shadow and clear classes, then compared to the output of the cloud and shadow detection. The comparison on VIIRS images showed 94.2% correct detection rates and 11.1% false alarms for clouds, and respectively 36.1% and 82.7% for shadows. The results on cloud detection were similar to state-of-the-art methods. Shadows showed correctly on the northern edge of the clouds, but many shadows were wrongly assigned to other classes in some cases (e.g., to water class on lake and forest boundary, or with shadows over cloud. This may be due to the low spatial resolution of VIIRS images, where shadows are only a few pixels wide and contain lots of mixed pixels.

Shadows of Einstein–dilaton–Gauss–Bonnet black holes

Energy Technology Data Exchange (ETDEWEB)

Cunha, Pedro V.P., E-mail: pintodacunha@tecnico.ulisboa.pt [Departamento de Física da Universidade de Aveiro and Centre for Research and Development in Mathematics and Applications (CIDMA), Campus de Santiago, 3810-183 Aveiro (Portugal); CENTRA, Departamento de Física, Instituto Superior Técnico, Universidade de Lisboa, Avenida Rovisco Pais 1, 1049, Lisboa (Portugal); Herdeiro, Carlos A.R., E-mail: herdeiro@ua.pt [Departamento de Física da Universidade de Aveiro and Centre for Research and Development in Mathematics and Applications (CIDMA), Campus de Santiago, 3810-183 Aveiro (Portugal); Kleihaus, Burkhard, E-mail: b.kleihaus@uni-oldenburg.de [Institute of Physics, University of Oldenburg, Oldenburg, 26111 (Germany); Kunz, Jutta, E-mail: jutta.kunz@uni-oldenburg.de [Institute of Physics, University of Oldenburg, Oldenburg, 26111 (Germany); Radu, Eugen, E-mail: eugen.radu@ua.pt [Departamento de Física da Universidade de Aveiro and Centre for Research and Development in Mathematics and Applications (CIDMA), Campus de Santiago, 3810-183 Aveiro (Portugal)

2017-05-10

We study the shadows of the fully non-linear, asymptotically flat Einstein–dilaton–Gauss–Bonnet (EdGB) black holes (BHs), for both static and rotating solutions. We find that, in all cases, these shadows are smaller than for comparable Kerr BHs, i.e. with the same total mass and angular momentum under similar observation conditions. In order to compare both cases we provide quantitative shadow parameters, observing in particular that the differences in the shadows mean radii are never larger than the percent level. Therefore, generically, EdGB BHs cannot be excluded by (near future) shadow observations alone. On the theoretical side, we find no clear signature of some exotic features of EdGB BHs on the corresponding shadows, such as the regions of negative (Komar, say) energy density outside the horizon. We speculate that this is due to the fact that the Komar energy interior to the light rings (or more precisely, the surfaces of constant radial coordinate that intersect the light rings in the equatorial plane) is always smaller than the ADM mass, and consequently the corresponding shadows are smaller than those of comparable Kerr BHs. The analysis herein provides a clear example that it is the light ring impact parameter, rather than its “size”, that determines a BH shadow.

Fully Convolutional Network Based Shadow Extraction from GF-2 Imagery

Science.gov (United States)

Li, Z.; Cai, G.; Ren, H.

2018-04-01

There are many shadows on the high spatial resolution satellite images, especially in the urban areas. Although shadows on imagery severely affect the information extraction of land cover or land use, they provide auxiliary information for building extraction which is hard to achieve a satisfactory accuracy through image classification itself. This paper focused on the method of building shadow extraction by designing a fully convolutional network and training samples collected from GF-2 satellite imagery in the urban region of Changchun city. By means of spatial filtering and calculation of adjacent relationship along the sunlight direction, the small patches from vegetation or bridges have been eliminated from the preliminary extracted shadows. Finally, the building shadows were separated. The extracted building shadow information from the proposed method in this paper was compared with the results from the traditional object-oriented supervised classification algorihtms. It showed that the deep learning network approach can improve the accuracy to a large extent.

Least Squares Shadowing Sensitivity Analysis of Chaotic Flow Around a Two-Dimensional Airfoil

Science.gov (United States)

Blonigan, Patrick J.; Wang, Qiqi; Nielsen, Eric J.; Diskin, Boris

2016-01-01

Gradient-based sensitivity analysis has proven to be an enabling technology for many applications, including design of aerospace vehicles. However, conventional sensitivity analysis methods break down when applied to long-time averages of chaotic systems. This breakdown is a serious limitation because many aerospace applications involve physical phenomena that exhibit chaotic dynamics, most notably high-resolution large-eddy and direct numerical simulations of turbulent aerodynamic flows. A recently proposed methodology, Least Squares Shadowing (LSS), avoids this breakdown and advances the state of the art in sensitivity analysis for chaotic flows. The first application of LSS to a chaotic flow simulated with a large-scale computational fluid dynamics solver is presented. The LSS sensitivity computed for this chaotic flow is verified and shown to be accurate, but the computational cost of the current LSS implementation is high.

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

Tax Evasion and the Shadow Economy

OpenAIRE

Oliver Reimers

2015-01-01

Leading scholars examine recent evidence from theoretical and empirical research on tax compliance and tax evasion, and provide an in-depth analysis of underlying methods. Strategies to fight tax evasion are evaluated and the motivations behind it are explored, as are the impact and size of the shadow economy in Europe. As well as promoting a better understanding of the issues, this book intends to stimulate further debate and, in so doing, broaden the exchange of ideas and concepts.

Statistical Removal of Shadow for Applications to Gait Recognition

National Research Council Canada - National Science Library

Hockersmith, Brian

2008-01-01

.... The thesis begins with the analysis of videos of solid colored backgrounds. A formulation of the effect of shadow on specified colors will aid in the derivation of a hypothesis test to remove an individual's shadow...

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.

Asymptotic Ergodic Capacity Analysis of Composite Lognormal Shadowed Channels

KAUST Repository

Ansari, Imran Shafique; Alouini, Mohamed-Slim

2015-01-01

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.

Method and apparatus for shadow aperture backscatter radiography (SABR) system and protocol

Science.gov (United States)

Shedlock, Daniel (Inventor); Jacobs, Alan M. (Inventor); Jacobs, Sharon Auerback (Inventor); Dugan, Edward (Inventor)

2010-01-01

A shadow aperture backscatter radiography (SABR) system includes at least one penetrating radiation source for providing a penetrating radiation field, and at least one partially transmissive radiation detector, wherein the partially transmissive radiation detector is interposed between an object region to be interrogated and the radiation source. The partially transmissive radiation detector transmits a portion of the illumination radiation field. A shadow aperture having a plurality of radiation attenuating regions having apertures therebetween is disposed between the radiation source and the detector. The apertures provide illumination regions for the illumination radiation field to reach the object region, wherein backscattered radiation from the object is detected and generates an image by the detector in regions of the detector that are shadowed by the radiation attenuation regions.

Shadow edge lithography for nanoscale patterning and manufacturing

International Nuclear Information System (INIS)

Bai, John G; Chang, C-L; Chung, Jae-Hyun; Lee, Kyong-Hoon

2007-01-01

We demonstrate a wafer-scale nanofabrication method using the shadow effect in physical vapor deposition. An analytical model is presented to predict the formation of nanoscale gaps created by the shadow effect of a prepatterned edge on a deposition plane. The theoretical prediction agrees quantitatively with the widths of the fabricated nanogaps and nanochannels. In the diffusion experiments, both λ-DNA and fluorescein molecules were successfully introduced into the nanochannels. The proposed shadow edge lithography has potential to be a candidate for mass-producing nanostructures

Using shadow page cache to improve isolated drivers performance.

Science.gov (United States)

Zheng, Hao; Dong, Xiaoshe; Wang, Endong; Chen, Baoke; Zhu, Zhengdong; Liu, Chengzhe

2015-01-01

With the advantage of the reusability property of the virtualization technology, users can reuse various types and versions of existing operating systems and drivers in a virtual machine, so as to customize their application environment. In order to prevent users' virtualization environments being impacted by driver faults in virtual machine, Chariot examines the correctness of driver's write operations by the method of combining a driver's write operation capture and a driver's private access control table. However, this method needs to keep the write permission of shadow page table as read-only, so as to capture isolated driver's write operations through page faults, which adversely affect the performance of the driver. Based on delaying setting frequently used shadow pages' write permissions to read-only, this paper proposes an algorithm using shadow page cache to improve the performance of isolated drivers and carefully study the relationship between the performance of drivers and the size of shadow page cache. Experimental results show that, through the shadow page cache, the performance of isolated drivers can be greatly improved without impacting Chariot's reliability too much.

What is shadow banking?

NARCIS (Netherlands)

Claessens, S.; Ratnovski, L.

2014-01-01

There is much confusion about what shadow banking is. Some equate it with securitization, others with non-traditional bank activities, and yet others with non-bank lending. Regardless, most think of shadow banking as activities that can create systemic risk. This paper proposes to describe shadow

Physics of nuclear anti-shadowing

Energy Technology Data Exchange (ETDEWEB)

Schmidt, I. [Universidad Tecnica Federico Santa Maria, Dept. de Fisica, Valparaiso (Chile)

2005-07-01

Shadowing and anti-shadowing of the electromagnetic nuclear structure functions are produced by the coherence of multi-scattering quark nuclear processes. This picture leads to substantially different anti-shadowing for charged and neutral current processes, particularly in neutrino reactions, thus affecting the extraction of the weak-mixing angle sin{sup 2}({theta}{sub W}). We have found that the shadowing/anti-shadowing effect on the weak-mixing angle is approximately: {delta}sin{sup 2}({theta}{sub W}) = 0.001.

MISLEADING SHADOW

OpenAIRE

Sreenivas; Chandrasekhar

2015-01-01

In a suspected foreign body of bronchus or esophagus a radiograph of chest is essential and sometimes artifacts on radiographs mislead the treating doctor. A round radio opaque shadow on a radiograph of chest in a child who was operated for atrial septal defect mislead for a coin in esophagus and knowledge of the shadow avoided major surgical intervention .

Reusable High Aspect Ratio 3-D Nickel Shadow Mask

Science.gov (United States)

Shandhi, M.M.H.; Leber, M.; Hogan, A.; Warren, D.J.; Bhandari, R.; Negi, S.

2017-01-01

Shadow Mask technology has been used over the years for resistless patterning and to pattern on unconventional surfaces, fragile substrate and biomaterial. In this work, we are presenting a novel method to fabricate high aspect ratio (15:1) three-dimensional (3D) Nickel (Ni) shadow mask with vertical pattern length and width of 1.2 mm and 40 μm respectively. The Ni shadow mask is 1.5 mm tall and 100 μm wide at the base. The aspect ratio of the shadow mask is 15. Ni shadow mask is mechanically robust and hence easy to handle. It is also reusable and used to pattern the sidewalls of unconventional and complex 3D geometries such as microneedles or neural electrodes (such as the Utah array). The standard Utah array has 100 active sites at the tip of the shaft. Using the proposed high aspect ratio Ni shadow mask, the Utah array can accommodate 300 active sites, 200 of which will be along and around the shaft. The robust Ni shadow mask is fabricated using laser patterning and electroplating techniques. The use of Ni 3D shadow mask will lower the fabrication cost, complexity and time for patterning out-of-plane structures. PMID:29056835

A review of neutron scattering correction for the calibration of neutron survey meters using the shadow cone method

Energy Technology Data Exchange (ETDEWEB)

Kim, Sang In; Kim, Bong Hwan; Kim, Jang Lyul; Lee, Jung Il [Health Physics Team, Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

2015-12-15

The calibration methods of neutron-measuring devices such as the neutron survey meter have advantages and disadvantages. To compare the calibration factors obtained by the shadow cone method and semi-empirical method, 10 neutron survey meters of five different types were used in this study. This experiment was performed at the Korea Atomic Energy Research Institute (KAERI; Daejeon, South Korea), and the calibration neutron fields were constructed using a {sup 252}Californium ({sup 252}Cf) neutron source, which was positioned in the center of the neutron irradiation room. The neutron spectra of the calibration neutron fields were measured by a europium-activated lithium iodide scintillator in combination with KAERI's Bonner sphere system. When the shadow cone method was used, 10 single moderator-based survey meters exhibited a smaller calibration factor by as much as 3.1 - 9.3% than that of the semi-empirical method. This finding indicates that neutron survey meters underestimated the scattered neutrons and attenuated neutrons (i.e., the total scatter corrections). This underestimation of the calibration factor was attributed to the fact that single moderator-based survey meters have an under-ambient dose equivalent response in the thermal or thermal-dominant neutron field. As a result, when the shadow cone method is used for a single moderator-based survey meter, an additional correction and the International Organization for Standardization standard 8529-2 for room-scattered neutrons should be considered.

A review of neutron scattering correction for the calibration of neutron survey meters using the shadow cone method

International Nuclear Information System (INIS)

Kim, Sang In; Kim, Bong Hwan; Kim, Jang Lyul; Lee, Jung Il

2015-01-01

The calibration methods of neutron-measuring devices such as the neutron survey meter have advantages and disadvantages. To compare the calibration factors obtained by the shadow cone method and semi-empirical method, 10 neutron survey meters of five different types were used in this study. This experiment was performed at the Korea Atomic Energy Research Institute (KAERI; Daejeon, South Korea), and the calibration neutron fields were constructed using a 252 Californium ( 252 Cf) neutron source, which was positioned in the center of the neutron irradiation room. The neutron spectra of the calibration neutron fields were measured by a europium-activated lithium iodide scintillator in combination with KAERI's Bonner sphere system. When the shadow cone method was used, 10 single moderator-based survey meters exhibited a smaller calibration factor by as much as 3.1 - 9.3% than that of the semi-empirical method. This finding indicates that neutron survey meters underestimated the scattered neutrons and attenuated neutrons (i.e., the total scatter corrections). This underestimation of the calibration factor was attributed to the fact that single moderator-based survey meters have an under-ambient dose equivalent response in the thermal or thermal-dominant neutron field. As a result, when the shadow cone method is used for a single moderator-based survey meter, an additional correction and the International Organization for Standardization standard 8529-2 for room-scattered neutrons should be considered

Method for observing phase objects without halos and directional shadows

Science.gov (United States)

Suzuki, Yoshimasa; Kajitani, Kazuo; Ohde, Hisashi

2015-03-01

A new microscopy method for observing phase objects without halos and directional shadows is proposed. The key optical element is an annular aperture at the front focal plane of a condenser with a larger diameter than those used in standard phase contrast microscopy. The light flux passing through the annular aperture is changed by the specimen's surface profile and then passes through an objective and contributes to image formation. This paper presents essential conditions for realizing the method. In this paper, images of colonies formed by induced pluripotent stem (iPS) cells using this method are compared with the conventional phase contrast method and the bright-field method when the NA of the illumination is small to identify differences among these techniques. The outlines of the iPS cells are clearly visible with this method, whereas they are not clearly visible due to halos when using the phase contrast method or due to weak contrast when using the bright-field method. Other images using this method are also presented to demonstrate a capacity of this method: a mouse ovum and superimposition of several different images of mouse iPS cells.

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

Using Shadow Page Cache to Improve Isolated Drivers Performance

Directory of Open Access Journals (Sweden)

Hao Zheng

2015-01-01

Full Text Available With the advantage of the reusability property of the virtualization technology, users can reuse various types and versions of existing operating systems and drivers in a virtual machine, so as to customize their application environment. In order to prevent users’ virtualization environments being impacted by driver faults in virtual machine, Chariot examines the correctness of driver’s write operations by the method of combining a driver’s write operation capture and a driver’s private access control table. However, this method needs to keep the write permission of shadow page table as read-only, so as to capture isolated driver’s write operations through page faults, which adversely affect the performance of the driver. Based on delaying setting frequently used shadow pages’ write permissions to read-only, this paper proposes an algorithm using shadow page cache to improve the performance of isolated drivers and carefully study the relationship between the performance of drivers and the size of shadow page cache. Experimental results show that, through the shadow page cache, the performance of isolated drivers can be greatly improved without impacting Chariot’s reliability too much.

Innocent Body-Shadow Mimics Physical Body

Directory of Open Access Journals (Sweden)

Kenri Kodaka

2017-04-01

Full Text Available The paradigm of the rubber hand illusion was applied to a shadow to determine whether the body-shadow is a good candidate for the alternative belonging to our body. Three kinds of shadows, a physical hand, a hand-shaped cloth, and a rectangle cloth, were tested for this purpose. The questionnaire results showed that both anatomical similarity and visuo-proprioception correlation were effective in enhancing illusory ownership of the shadow. According to the proprioceptive drift measurement, whether the shadow purely originated from the physical body was a critical factor in yielding the significantly positive drift. Thus, results demonstrated that the shadow can distort illusory ownership with the rubber hand illusion paradigm, but the proprioception was clearly distorted only when the body-shadow was purely applied. This implies the presence of special cognitive processing to discriminate the self-body shadow from the others.

Shadow Soldiering

DEFF Research Database (Denmark)

Mynster Christensen, Maya

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......, or in the margins of official political economies. Rather, shadow soldiering is a phenomenon that is becoming increasingly central in the context of security outsourcing and militarisation in a global economy....

Shadow Corrosion Mechanism of Zircaloy

International Nuclear Information System (INIS)

Ullberg, Mats; Lysell, Gunnar; Nystrand, Ann-Charlotte

2004-02-01

Local corrosion enhancement appears on zirconium-base alloys in-core in boiling water reactors when the zirconium alloy is in close proximity to another metal. The visual appearance often resembles a shadow of the other component. The phenomenon is therefore referred to as 'shadow corrosion'. Shadow corrosion has been known for more than 25 years. Mechanisms based on either galvanic corrosion or local radiolysis effects have been proposed as explanations. Both types of mechanism have seemed to explain some facets of the phenomenon. Normally, shadow corrosion is of no practical significance. However, an enhanced and potentially serious form of shadow corrosion was discovered in 1996. This discovery stimulated new experiments that fully supported neither of the longstanding theories. Thus, there is till now no generally accepted understanding of the shadow corrosion phenomenon. The aim of the present investigation was to analyse the available data and to identify, if possible, a plausible mechanism of shadow corrosion. It was found that the experimental evidence is, with a few exceptions, remarkably consistent with a galvanic mechanism. The main exception is that shadow corrosion may occur also when the two metals are nominally electrically insulated. One way to account for the main exception could be to invoke the effect of photoconductivity. Photoconductivity results when a semiconductor or an insulator is irradiated with photons of UV or higher energy. The photons elevate electrons from the valence band to the conduction band, thereby raising the electron conductivity of the solid. In particular, photoconductivity lowers the electrical resistance of the normally insulating oxide on zirconium base alloys. Photoconductivity therefore also has the potential to explain why shadow corrosion is only seen in, or in proximity to, a nuclear reactor core. The suggested mechanism of shadow corrosion can be tested in a reasonably simple experiment in a research reactor

FIELD INVESTIGATION OF THE DRIFT SHADOW

International Nuclear Information System (INIS)

G.W. Su; T.J. Kneafsey

2006-01-01

A drift shadow is an area immediately beneath an underground void that, in theory, will be relatively drier than the surrounding rock mass. Numerical and analytical models of water flow through unsaturated rock predict the existence of a drift shadow, but field tests confirming the existence of the drift shadow have yet to be performed. Proving the existence of drift shadows and understanding their hydrologic and transport characteristics could provide a better understanding of how contaminants move in the subsurface if released from waste emplacement drifts such as the proposed nuclear waste repository at Yucca Mountain, Nevada. We describe the field program that will be used to investigate the existence of a drift shadow--and the corresponding hydrological process at the Hazel-Atlas silica-sand mine located at the Black Diamond Mines Regional Preserve in Antioch, California. The location and configuration of this mine makes it an excellent site to observe and measure drift shadow characteristics. The mine is located in a porous sandstone unit of the Domengine formation, an approximately 230 meter thick series of interbedded Eocene-age shales, coals, and massive-bedded sandstones. The mining method used at the mine required the development of two parallel drifts, one above the other, driven along the strike of the mined sandstone stratum. This configuration provides the opportunity to introduce water into the rock mass in the upper drift and to observe and measure its flow around the underlying drift. The passive and active hydrologic tests to be performed are described. In the passive method, cores will be obtained in a radial pattern around a drift and will be sectioned and analyzed for in-situ water content using a gravimetric technique, as well as analyzed for chemistry. With the active hydrologic test, water will be introduced into the upper drift of the two parallel drifts and the flow of the water will be tracked as it passes near the bottom drift

Coupled orbit-attitude motion of high area-to-mass ratio (HAMR) objects including efficient self-shadowing

Science.gov (United States)

Früh, Carolin; Jah, Moriba K.

2014-02-01

This paper shows the effect of self-shadowing on the coupled attitude-orbit dynamics of objects with high area-to-mass ratios (HAMR) in simulating standard multi layer insulation materials (MLI) as tilted single rigid sheets. Efficient and computationally fast self-shadowing methods have been developed. This includes an approximate self-shadowing method and a rapid exact self-shadowing method. Accuracy considerations are made and the effect of a chosen tessellation is shown. The coupled orbit-attitude perturbations of solar radiation pressure and Earth gravity field are taken into account. The results are compared to the attitude-orbit dynamics, when neglecting self-shadowing effects. An averaged physical shadow-map model is developed and compared to the full self-shadowing simulation. The combined effect of solar radiation pressure and self-shadowing leads to a rapid spin-up of the objects, even though they have uniform reflection properties. As a result, the observed brightness of these objects is subject to rapid changes.

The impact of economic globalization on the shadow economy in Egypt

OpenAIRE

Farzanegan, Mohammad Reza; Hassan, Mai

2017-01-01

This study examines the economic globalization and the shadow economy nexus in Egypt. Using time series data from 1976 to 2013, the impulse response analysis shows that the response of the shadow economy in Egypt to positive shocks in economic globalization is negative and statistically significant for the first three years following the shock. This finding is obtained by controlling for several intermediary channels in globalization-shadow economy nexus such as education, government spending...

Cryptography with chaos and shadowing

International Nuclear Information System (INIS)

Smaoui, Nejib; Kanso, Ali

2009-01-01

In this paper, we present a novel approach to encrypt a message (a text composed by some alphabets) using chaos and shadowing. First, we generate a numerical chaotic orbit based on the logistic map, and use the shadowing algorithm of Smaoui and Kostelich [Smaoui N, Kostelich E. Using chaos to shadow the quadratic map for all time. Int J Comput Math 1998;70:117-29] to show that there exists a finite number of true orbits that shadow the numerical orbit. Then, the finite number of maps generated is used in Baptista's algorithm [Baptista MS. Cryptography with chaos. Phys Lett A 1998;240:50-4] to encrypt each character of the message. It is shown that the use of chaos and shadowing in the encryption process enhances the security level.

Cryptography with chaos and shadowing

Energy Technology Data Exchange (ETDEWEB)

Smaoui, Nejib [Department of Mathematics and Computer Science, Kuwait University, P.O. Box 5969, Safat 13060 (Kuwait)], E-mail: nsmaoui64@yahoo.com; Kanso, Ali [Department of Mathematics and Computer Science, Kuwait University, P.O. Box 5969, Safat 13060 (Kuwait)], E-mail: akanso@hotmail.com

2009-11-30

In this paper, we present a novel approach to encrypt a message (a text composed by some alphabets) using chaos and shadowing. First, we generate a numerical chaotic orbit based on the logistic map, and use the shadowing algorithm of Smaoui and Kostelich [Smaoui N, Kostelich E. Using chaos to shadow the quadratic map for all time. Int J Comput Math 1998;70:117-29] to show that there exists a finite number of true orbits that shadow the numerical orbit. Then, the finite number of maps generated is used in Baptista's algorithm [Baptista MS. Cryptography with chaos. Phys Lett A 1998;240:50-4] to encrypt each character of the message. It is shown that the use of chaos and shadowing in the encryption process enhances the security level.

Analysis on Human Blockage Path Loss and Shadow Fading in Millimeter-Wave Band

Directory of Open Access Journals (Sweden)

Hongmei Zhao

2017-01-01

Full Text Available Millimeter-wave (Mm-w is the trend of communication development in the future; users who carry mobile communication equipment could be blocked by others in a crowded population environment. Based on Shooting and Bouncing Ray (SBR method and setting up different orientation receivers (RX, population density, and people fabric property at 28 GHz and 38 GHz, simulating experimental scene similar to station square by Wireless Insite software, we use least square method to do linear-regression analysis for path loss and build path loss model. The result shows that the path loss index has a certain change in the different frequency, orientation receivers, population density, and people fabric. The path loss index of RouteC1 and RouteA2 has an obvious change in the central transmitter (TX. Each route shadow fading obeys Gaussian distribution whose mean is 0. This paper’s result has a theoretical guiding for designing the communication system in a crowded population environment.

Field investigation of the drift shadow

International Nuclear Information System (INIS)

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

2005-01-01

A drift shadow is an area immediately beneath an underground void that, in theory, will be relatively drier than the surrounding rockmass. Numerical and analytical models of water flow through unsaturated rock predict the existence of a drift shadow, but field tests confirming its existence have yet to be performed. Proving the existence of drift shadows and understanding their hydrologic and transport characteristics could provide a better understanding of how contaminants move in the subsurface if released from waste emplacement drifts such as the proposed nuclear waste repository at Yucca Mountain, Nevada. We describe the field program that will be used to investigate the existence of a drift shadow and 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 an excellent site to observe and measure drift shadow characteristics. The mine is located in a porous sandstone unit of the Domengine Formation, an approximately 230 meter thick series of interbedded Eocene-age shales, coals, and massive-bedded sandstones. The mining method used at the mine required the development of two parallel drifts, one above the other, driven along the strike of the mined sandstone stratum. This configuration provides the opportunity to introduce water into the rockmass in the upper drift and to observe and measure its flow around the underlying drift. The passive and active hydrologic tests to be performed are described. In the passive method, cores will be obtained in a radial pattern around a drift and will be sectioned and analyzed for in-situ water content and chemical constituents. With the active hydrologic test, water will be introduced into the upper drift of the two parallel drifts and the flow of the water will be tracked as it passes near the bottom drift. Tensiometers, electrical resistance probes, neutron probes, and ground

Fabrication of high-aspect-ratio nano structures using a nano x-ray shadow mask

International Nuclear Information System (INIS)

Kim, Yong Chul; Lee, Seung S

2008-01-01

This paper describes a novel method for the fabrication of high-aspect-ratio nano structures (HAR-nano structures) using a nano x-ray shadow mask and deep x-ray lithography (DXRL). The nano x-ray shadow mask is fabricated by depositing an x-ray absorber layer (Au, 3 µm) onto the back side of a nano shadow mask. The nano shadow mask is produced with nano-sized apertures whose dimensions are reduced to several tens of nanometers by the accumulation of low-stress silicon nitride (Si x N y ) using the LPCVD process on the shadow mask. A shadow mask containing apertures with a size of 1 µm is fabricated on a bulk micromachined Si x N y membrane. The thickness of an absorber layer must be in the range of several tens of micrometers in order to obtain a contrast of more than 100 for the conventional DXRL process at the Pohang Light Source (PLS). However, a 3 µm thick absorber layer can provide a sufficient contrast if the modified DXRL of the central beam-stop method is used, which blocks high-energy x-rays. A nano shadow mask with 30 nm sized apertures is fabricated and a nano x-ray shadow mask with 250 nm sized apertures is fabricated by depositing a 3 µm thick absorber layer on a nano shadow mask with 500 nm sized apertures. HAR-nano structures (circles with a diameter of 420 nm and lines with a width of 274 nm) with aspect ratios of over 10:1 on a 3.2 µm SU-8 are successfully fabricated by using the nano x-ray shadow mask and the central beam-stop method

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.

What Colour Is a Shadow?

Science.gov (United States)

Hughes, S. W.

2009-01-01

What colour is a shadow? Black, grey, or some other colour? This article describes how to use a digital camera to test the hypothesis that a shadow under a clear blue sky has a blue tint. A white sheet of A4 paper was photographed in full sunlight and in shadow under a clear blue sky. The images were analysed using a shareware program called…

Engineering shadows to fabricate optical metasurfaces.

Science.gov (United States)

Nemiroski, Alex; Gonidec, Mathieu; Fox, Jerome M; Jean-Remy, Philip; Turnage, Evan; Whitesides, George M

2014-11-25

Optical metasurfaces-patterned arrays of plasmonic nanoantennas that enable the precise manipulation of light-matter interactions-are emerging as critical components in many nanophotonic materials, including planar metamaterials, chemical and biological sensors, and photovoltaics. The development of these materials has been slowed by the difficulty of efficiently fabricating patterns with the required combinations of intricate nanoscale structure, high areal density, and/or heterogeneous composition. One convenient strategy that enables parallel fabrication of periodic nanopatterns uses self-assembled colloidal monolayers as shadow masks; this method has, however, not been extended beyond a small set of simple patterns and, thus, has remained incompatible with the broad design requirements of metasurfaces. This paper demonstrates a technique-shadow-sphere lithography (SSL)-that uses sequential deposition from multiple angles through plasma-etched microspheres to expand the variety and complexity of structures accessible by colloidal masks. SSL harnesses the entire, relatively unexplored, space of shadow-derived shapes and-with custom software to guide multiangled deposition-contains sufficient degrees of freedom to (i) design and fabricate a wide variety of metasurfaces that incorporate complex structures with small feature sizes and multiple materials and (ii) generate, in parallel, thousands of variations of structures for high-throughput screening of new patterns that may yield unexpected optical spectra. This generalized approach to engineering shadows of spheres provides a new strategy for efficient prototyping and discovery of periodic metasurfaces.

The effects of shadow banking on the traditional banking system in Zimbabwe

Directory of Open Access Journals (Sweden)

Virimai Mugobo

2015-11-01

Full Text Available The growth of shadow banks changed the face of banking in Zimbabwe. Their inconsistent product nature and complexity of form has been a cause for concern to regulatory authorities. The interrelationship between their financial intermediary role and that of formal banks has made them good substitutes to formal banking. This study conducts a statistical analysis of the country’s monetary aggregates and the total formal bank loan-to-deposits balances. The findings of this analysis show that the shadow banking system has always been a critical element of the formal banking sector which resulted from market needs and it completes the banking system. The shadow banking system does not pose direct threat to the formal banking system but it was a result of failure to attract savers who found shadow banks as a good alternative.

Shadows behind the computers

CERN Document Server

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...

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.

47 CFR 80.769 - Shadow loss.

Science.gov (United States)

2010-10-01

... 47 Telecommunication 5 2010-10-01 2010-10-01 false Shadow loss. 80.769 Section 80.769... MARITIME SERVICES Standards for Computing Public Coast Station VHF Coverage § 80.769 Shadow loss. Where the transmission path is obstructed the received signal must be adjusted to include shadow loss. Attenuation due to...

Construction of Discrete Time Shadow Price

International Nuclear Information System (INIS)

Rogala, Tomasz; Stettner, Lukasz

2015-01-01

In the paper expected utility from consumption over finite time horizon for discrete time markets with bid and ask prices and strictly concave utility function is considered. The notion of weak shadow price, i.e. an illiquid price, depending on the portfolio, under which the model without bid and ask price is equivalent to the model with bid and ask price is introduced. Existence and the form of weak shadow price is shown. Using weak shadow price usual (called in the paper strong) shadow price is then constructed

Measuring the CO2 shadow price for wastewater treatment: A directional distance function approach

International Nuclear Information System (INIS)

Molinos-Senante, María; Hanley, Nick; Sala-Garrido, Ramón

2015-01-01

Highlights: • The shadow price of CO 2 informs about the marginal abatement cost of this pollutant. • It is estimated the shadow price of CO 2 for wastewater treatment plants. • The shadow prices depend on the setting of the directional vectors of the distance function. • Sewage sludge treatment technology affects the CO 2 shadow price. - Abstract: The estimation of the value of carbon emissions has become a major research and policy topic since the establishment of the Kyoto Protocol. The shadow price of CO 2 provides information about the marginal abatement cost of this pollutant. It is an essential element in guiding environmental policy issues, since the CO 2 shadow price can be used when fixing carbon tax rates, in environmental cost-benefit analysis and in ascertaining an initial market price for a trading system. The water industry could play an important role in the reduction of greenhouse gas (GHG) emissions. This paper estimates the shadow price of CO 2 for a sample of wastewater treatment plants (WWTPs), using a parametric quadratic directional distance function. Following this, in a sensitivity analysis, the paper evaluates the impact of different settings of directional vectors on the shadow prices. Applying the Mann–Whitney and Kruskal–Wallis non-parametric tests, factors affecting CO 2 prices are investigated. The variation of CO 2 shadow prices across the WWTPs evaluated argues in favour of a market-based approach to CO 2 mitigation as opposed to command-and-control regulation. The paper argues that the estimation of the shadow price of CO 2 for non-power enterprises can provide incentives for reducing GHG emissions

Sovereign ratings in the post-crisis world : an analysis of actual, shadow and relative risk ratings

OpenAIRE

Basu, Kaushik; De, Supriyo; Ratha, Dilip; Timmer, Hans

2013-01-01

This paper analyzes the evolution of sovereign credit ratings in the wake of the global financial crisis by studying changes in actual, shadow, and relative ratings between 2008 and 2012. For countries that do not have a rating from the major rating agencies, shadow ratings are estimated as a function of macroeconomic, structural, and governance variables. The shadow rating exercise confir...

Shadowing in inelastic lepton-deuteron scattering

International Nuclear Information System (INIS)

Badelek, B.

1992-01-01

Shadowing in inelastic lepton-deuteron scattering is analysed using the double interaction formalism where we relate shadowing to inclusive diffractive processes. Both the vector meson and parton contributions are considered for low and high Q 2 values including QCD corrections with parton recombination for high Q 2 . These Q 2 values were chosen to correspond to existing experimental data and to the possible HERA measurements. Detailed discussion of various shadowing mechanisms is given. As expected the shadowing effects are found to be very small, less then 2% or so, in agreement with the recent precise measurements performed by the New Muon Collaboration. The contribution of shadowing term to the Gottfried sum the region x > 0.004 and for Q 2 = 4 GeV 2 is estimated to be equal to -0.025. (author). 10 refs, 4 figs

Enhancement of bone shadow region using local phase-based ultrasound transmission maps.

Science.gov (United States)

Hacihaliloglu, Ilker

2017-06-01

Ultrasound is increasingly being employed in different orthopedic procedures as an imaging modality for real-time guidance. Nevertheless, low signal-to-noise-ratio and different imaging artifacts continue to hamper the success of ultrasound-based procedures. Bone shadow region is an important feature indicating the presence of bone/tissue interface in the acquired ultrasound data. Enhancement and automatic detection of this region could improve the sensitivity of ultrasound for imaging bone and result in improved guidance for various orthopedic procedures. In this work, a method is introduced for the enhancement of bone shadow regions from B-mode ultrasound data. The method is based on the combination of three different image phase features: local phase tensor, local weighted mean phase angle, and local phase energy. The combined local phase image features are used as an input to an [Formula: see text] norm-based contextual regularization method which emphasizes uncertainty in the shadow regions. The enhanced bone shadow images are automatically segmented and compared against expert segmentation. Qualitative and quantitative validation was performed on 100 in vivo US scans obtained from five subjects by scanning femur and vertebrae bones. Validation against expert segmentation achieved a mean dice similarity coefficient of 0.88. The encouraging results obtained in this initial study suggest that the proposed method is promising enough for further evaluation. The calculated bone shadow maps could be incorporated into different ultrasound bone segmentation and registration approaches as an additional feature.

Simulation of scanning geometry for Shadow Shield counter using Monte Carlo method

International Nuclear Information System (INIS)

Deepu, R.; Manohari, M.; Mathiyarasu, R.

2018-01-01

The whole body counting facility at RSD, IGCAR employs a Shadow Shield Counter (SSC) for the assessment of internal exposure of radiation workers from fission and activation products. The SSC system is routinely calibrated using an in-house built Masonite cut sheet phantom, loaded with standard point sources, in scanning mode. The system is capable of measuring gamma energy from 200 keV to 3 MeV. The standard sources available have energies in the range of 300 - 1500 keV. In order to extend the energy range, numerical simulation can be carried out. As, numerical methods cannot simulate scanning mode directly, a novel scheme is attempted to generate the efficiency value for scanning mode through the use of multiple static mode. The same method was also verified through measurement. The efficiency values of the simulation as well two measurements techniques were compared

Using Multiple Methods to teach ASTR 101 students the Path of the Sun and Shadows

Science.gov (United States)

D'Cruz, Noella L.

2015-01-01

It seems surprising that non-science major introductory astronomy students find the daily path of the Sun and shadows created by the Sun challenging to learn even though both can be easily observed (provided students do not look directly at the Sun). In order for our students to master the relevant concepts, we have usually used lecture, a lecture tutorial (from Prather, et al.) followed by think-pair-share questions, a planetarium presentation and an animation from the Nebraska Astronomy Applet Project to teach these topics. We cover these topics in a lecture-only, one semester introductory astronomy course at Joliet Junior College. Feedback from our Spring 2014 students indicated that the planetarium presentation was the most helpful in learning the path of the Sun while none of the four teaching methods was helpful when learning about shadows cast by the Sun. Our students did not find the lecture tutorial to be much help even though such tutorials have been proven to promote deep conceptual change. In Fall 2014, we continued to use these four methods, but we modified how we teach both topics so our students could gain more from the tutorial. We hoped our modifications would cause students to have a better overall grasp of the concepts. After our regular lecture, we gave a shorter than usual planetarium presentation on the path of the Sun and we asked students to work through a shadow activity from Project Astro materials. Then students completed the lecture tutorial and some think-pair-share questions. After this, we asked students to predict the Sun's path on certain days of the year and we used the planetarium projector to show them how well their predictions matched up. We ended our coverage of these topics by asking students a few more think-pair-share questions. In our poster, we will present our approach to teaching these topics in Fall 2014, how our Fall 2014 students feel about our teaching strategies and how they fared on related test questions.

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.

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

Shadow Detection Based on Regions of Light Sources for Object Extraction in Nighttime Video

Directory of Open Access Journals (Sweden)

Gil-beom Lee

2017-03-01

Full Text Available Intelligent video surveillance systems detect pre-configured surveillance events through background modeling, foreground and object extraction, object tracking, and event detection. Shadow regions inside video frames sometimes appear as foreground objects, interfere with ensuing processes, and finally degrade the event detection performance of the systems. Conventional studies have mostly used intensity, color, texture, and geometric information to perform shadow detection in daytime video, but these methods lack the capability of removing shadows in nighttime video. In this paper, a novel shadow detection algorithm for nighttime video is proposed; this algorithm partitions each foreground object based on the object’s vertical histogram and screens out shadow objects by validating their orientations heading toward regions of light sources. From the experimental results, it can be seen that the proposed algorithm shows more than 93.8% shadow removal and 89.9% object extraction rates for nighttime video sequences, and the algorithm outperforms conventional shadow removal algorithms designed for daytime videos.

Automatic Detection of Clouds and Shadows Using High Resolution Satellite Image Time Series

Science.gov (United States)

Champion, Nicolas

2016-06-01

Detecting clouds and their shadows is one of the primaries steps to perform when processing satellite images because they may alter the quality of some products such as large-area orthomosaics. The main goal of this paper is to present the automatic method developed at IGN-France for detecting clouds and shadows in a sequence of satellite images. In our work, surface reflectance orthoimages are used. They were processed from initial satellite images using a dedicated software. The cloud detection step consists of a region-growing algorithm. Seeds are firstly extracted. For that purpose and for each input ortho-image to process, we select the other ortho-images of the sequence that intersect it. The pixels of the input ortho-image are secondly labelled seeds if the difference of reflectance (in the blue channel) with overlapping ortho-images is bigger than a given threshold. Clouds are eventually delineated using a region-growing method based on a radiometric and homogeneity criterion. Regarding the shadow detection, our method is based on the idea that a shadow pixel is darker when comparing to the other images of the time series. The detection is basically composed of three steps. Firstly, we compute a synthetic ortho-image covering the whole study area. Its pixels have a value corresponding to the median value of all input reflectance ortho-images intersecting at that pixel location. Secondly, for each input ortho-image, a pixel is labelled shadows if the difference of reflectance (in the NIR channel) with the synthetic ortho-image is below a given threshold. Eventually, an optional region-growing step may be used to refine the results. Note that pixels labelled clouds during the cloud detection are not used for computing the median value in the first step; additionally, the NIR input data channel is used to perform the shadow detection, because it appeared to better discriminate shadow pixels. The method was tested on times series of Landsat 8 and Pl

AUTOMATIC DETECTION OF CLOUDS AND SHADOWS USING HIGH RESOLUTION SATELLITE IMAGE TIME SERIES

Directory of Open Access Journals (Sweden)

N. Champion

2016-06-01

Full Text Available Detecting clouds and their shadows is one of the primaries steps to perform when processing satellite images because they may alter the quality of some products such as large-area orthomosaics. The main goal of this paper is to present the automatic method developed at IGN-France for detecting clouds and shadows in a sequence of satellite images. In our work, surface reflectance orthoimages are used. They were processed from initial satellite images using a dedicated software. The cloud detection step consists of a region-growing algorithm. Seeds are firstly extracted. For that purpose and for each input ortho-image to process, we select the other ortho-images of the sequence that intersect it. The pixels of the input ortho-image are secondly labelled seeds if the difference of reflectance (in the blue channel with overlapping ortho-images is bigger than a given threshold. Clouds are eventually delineated using a region-growing method based on a radiometric and homogeneity criterion. Regarding the shadow detection, our method is based on the idea that a shadow pixel is darker when comparing to the other images of the time series. The detection is basically composed of three steps. Firstly, we compute a synthetic ortho-image covering the whole study area. Its pixels have a value corresponding to the median value of all input reflectance ortho-images intersecting at that pixel location. Secondly, for each input ortho-image, a pixel is labelled shadows if the difference of reflectance (in the NIR channel with the synthetic ortho-image is below a given threshold. Eventually, an optional region-growing step may be used to refine the results. Note that pixels labelled clouds during the cloud detection are not used for computing the median value in the first step; additionally, the NIR input data channel is used to perform the shadow detection, because it appeared to better discriminate shadow pixels. The method was tested on times series of Landsat 8

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

Extended shadow test approach for constrained adaptive testing

NARCIS (Netherlands)

Veldkamp, Bernard P.; Ariel, A.

2002-01-01

Several methods have been developed for use on constrained adaptive testing. Item pool partitioning, multistage testing, and testlet-based adaptive testing are methods that perform well for specific cases of adaptive testing. The weighted deviation model and the Shadow Test approach can be more

Integral transport multiregion geometrical shadowing factor for the approximate collision probability matrix calculation of infinite closely packed lattices

International Nuclear Information System (INIS)

Jowzani-Moghaddam, A.

1981-01-01

An integral transport method of calculating the geometrical shadowing factor in multiregion annular cells for infinite closely packed lattices in cylindrical geometry is developed. This analytical method has been programmed in the TPGS code. This method is based upon a consideration of the properties of the integral transport method for a nonuniform body, which together with Bonalumi's approximations allows the determination of the approximate multiregion collision probability matrix for infinite closely packed lattices with sufficient accuracy. The multiregion geometrical shadowing factors have been calculated for variations in fuel pin annular segment rings in a geometry of annular cells. These shadowing factors can then be used in the calculation of neutron transport from one annulus to another in an infinite lattice. The result of this new geometrical shadowing and collision probability matrix are compared with the Dancoff-Ginsburg correction and the probability matrix using constant shadowing on Yankee fuel elements in an infinite lattice. In these cases the Dancoff-Ginsburg correction factor and collision probability matrix using constant shadowing are in difference by at most 6.2% and 6%, respectively

The thoracic paraspinal shadow: normal appearances.

Science.gov (United States)

Lien, H H; Kolbenstvedt, A

1982-01-01

The width of the right and left thoracic paraspinal shadows were measured at all levels in 200 presumably normal individuals. The paraspinal shadow could be identified in nearly all cases on the left side and in approximately one-third on the right. The range of variation was greater on the left side than one the right. The left paraspinal shadow was wider at the upper levels and in individuals above 40 years of age.

Shadows and Silence: Analysis of Social and Environmental Reports of the Energy Sector

Directory of Open Access Journals (Sweden)

Fabrício do Nascimento Moreira

2016-04-01

Full Text Available While it is acknowledged that there has been a rapid growth in the disclosure of social and environmental responsibility reports of companies, it is assumed also that there is a long way to go in that these reports meet their users, stakeholders, considering the characteristics of materiality, consistency, integrity and accountability in the construction of accounting information. So with the need to advance this discussion, some scholars in the field of environmental accounting began to suggest, among other ideas, building models formed by basic reporting accounts silence and shadow, they could identify differences between perceived environmental performance the public interested in the activities and affairs of the entity and performance that corporations claim they have achieved through their accounts and reports publicly available. While the report is constructed from silent speech, vision and corporate positioning, the second shadow report, part of the stakeholder perspective, i.e., the desires of stakeholders in the activities and business of the company. The objective of the study is to explore if the preparation of shadow and silent report can contribute to the improvement of the information quality of corporate environmental performance reports. To achieve this goal, it was prepared the silent and shadow reports of ELETROBRAS system and later confronted. It was found that companies have trouble to expose negative social and environmental impacts in reports; the volume of news published on corporate websites is not as significant as shown by other studies and the companies, over the years, didn’t publish the reports in a regular basis and with the same pattern; among other findings. Finally, it was concluded that the shadow and silent reports could be used to improve the information quality in corporate environmental performance reports.

Shadow Toll in Colombia

OpenAIRE

González Ruiz, Juan David; Botero Botero, Sergio; Arboleda, Carlos Alejandro; Duque Grisales, Eduardo Alexander

2015-01-01

The growing development in infrastructure projects in Colombia has been linked to legal adjustments and capital markets. These two last factors have provided important elements for project developers to design funding strategies. Based on the shadow toll scheme, this paper proposes a new financing strategy for funding highway projects. This strategy may be implemented in Colombia. Finally, the paper proposes future research on shadow toll schemes as a financial mechanism.

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

NARCIS (Netherlands)

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

2001-01-01

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

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.

Automatic Shadow Detection and Removal from a Single Image.

Science.gov (United States)

Khan, Salman H; Bennamoun, Mohammed; Sohel, Ferdous; Togneri, Roberto

2016-03-01

We present a framework to automatically detect and remove shadows in real world scenes from a single image. Previous works on shadow detection put a lot of effort in designing shadow variant and invariant hand-crafted features. In contrast, our framework automatically learns the most relevant features in a supervised manner using multiple convolutional deep neural networks (ConvNets). The features are learned at the super-pixel level and along the dominant boundaries in the image. The predicted posteriors based on the learned features are fed to a conditional random field model to generate smooth shadow masks. Using the detected shadow masks, we propose a Bayesian formulation to accurately extract shadow matte and subsequently remove shadows. The Bayesian formulation is based on a novel model which accurately models the shadow generation process in the umbra and penumbra regions. The model parameters are efficiently estimated using an iterative optimization procedure. Our proposed framework consistently performed better than the state-of-the-art on all major shadow databases collected under a variety of conditions.

Convolutional Neural Network-Based Shadow Detection in Images Using Visible Light Camera Sensor

Directory of Open Access Journals (Sweden)

Dong Seop Kim

2018-03-01

Full Text Available Recent developments in intelligence surveillance camera systems have enabled more research on the detection, tracking, and recognition of humans. Such systems typically use visible light cameras and images, in which shadows make it difficult to detect and recognize the exact human area. Near-infrared (NIR light cameras and thermal cameras are used to mitigate this problem. However, such instruments require a separate NIR illuminator, or are prohibitively expensive. Existing research on shadow detection in images captured by visible light cameras have utilized object and shadow color features for detection. Unfortunately, various environmental factors such as illumination change and brightness of background cause detection to be a difficult task. To overcome this problem, we propose a convolutional neural network-based shadow detection method. Experimental results with a database built from various outdoor surveillance camera environments, and from the context-aware vision using image-based active recognition (CAVIAR open database, show that our method outperforms previous works.

Shadow Economy and Poverty

OpenAIRE

Nikopour, Hesam; Shah Habibullah, Muzafar

2010-01-01

This study attempts to investigate the relationship between shadow economy and poverty by explaining the mechanism through which shadow economy affects poverty via its impact on government size and economic growth, and using the human poverty index (HPI) for developing and developed countries. In order to achieve this objective, the three-way interaction model is utilized using data of 139 developing and 23 developed countries separately during 1999-2007. For developing countries the dynamic ...

Titan Casts Revealing Shadow

Science.gov (United States)

2004-05-01

A rare celestial event was captured by NASA's Chandra X-ray Observatory as Titan -- Saturn's largest moon and the only moon in the Solar System with a thick atmosphere -- crossed in front of the X-ray bright Crab Nebula. The X-ray shadow cast by Titan allowed astronomers to make the first X-ray measurement of the extent of its atmosphere. On January 5, 2003, Titan transited the Crab Nebula, the remnant of a supernova explosion that was observed to occur in the year 1054. Although Saturn and Titan pass within a few degrees of the Crab Nebula every 30 years, they rarely pass directly in front of it. "This may have been the first transit of the Crab Nebula by Titan since the birth of the Crab Nebula," said Koji Mori of Pennsylvania State University in University Park, and lead author on an Astrophysical Journal paper describing these results. "The next similar conjunction will take place in the year 2267, so this was truly a once in a lifetime event." Animation of Titan's Shadow on Crab Nebula Animation of Titan's Shadow on Crab Nebula Chandra's observation revealed that the diameter of the X-ray shadow cast by Titan was larger than the diameter of its solid surface. The difference in diameters gives a measurement of about 550 miles (880 kilometers) for the height of the X-ray absorbing region of Titan's atmosphere. The extent of the upper atmosphere is consistent with, or slightly (10-15%) larger, than that implied by Voyager I observations made at radio, infrared, and ultraviolet wavelengths in 1980. "Saturn was about 5% closer to the Sun in 2003, so increased solar heating of Titan may account for some of this atmospheric expansion," said Hiroshi Tsunemi of Osaka University in Japan, one of the coauthors on the paper. The X-ray brightness and extent of the Crab Nebula made it possible to study the tiny X-ray shadow cast by Titan during its transit. By using Chandra to precisely track Titan's position, astronomers were able to measure a shadow one arcsecond in

The shadow economy in industrial countries

OpenAIRE

Dominik H. Enste

2015-01-01

The shadow (underground) economy plays a major role in many countries. People evade taxes and regulations by working in the shadow economy or by employing people illegally. On the one hand, this unregulated economic activity can result in reduced tax revenue and public goods and services, lower tax morale and less tax compliance, higher control costs, and lower economic growth rates. But on the other hand, the shadow economy can be a powerful force for advancing institutional change and can b...

SHADOW GLOBALIZATION

Directory of Open Access Journals (Sweden)

Larissa Mihaylovna Kapitsa

2014-01-01

Full Text Available The article reviews some development trends brought about by globalization, particularly, a growing tax evasion and tax avoidance, an expansion of illicit financial flows and the proliferation of a global criminal network. The author draws attention to some new phenomena, particularly, cosmopolitanization of some parts of national elites and a deepening divide between national interests and the private interests of elites as a consequence of financial globalization. Modern mass media, both Russian and foreign, tend to interpret globalization processes exclusively from the position of conformism, and for some of the researchers globalization became the "sacred cow", which one may only worship. Critical analysis of the processes associated with globalization is given a hostile reception. In response to criticism of globalization, one can hear the very same argument: "globalization in inevitable!" Such a state of affairs, the very least, causes perplexity. Some of the world development trends been observed over the past years raise serious concerns about the security and welfare of the peoples of the world. One of such trends has been the globalization of shadow economic activities. Methods of fight against the criminal economy been applied in international practice can be grouped into: 1 punitive enforcement (or criminal-legal methods and 2 socio-economic methods. As the results of various research works evidence punitive enforcement methods not supported by socio-economic measures not effective enough. Toughening the control over criminal economic activities in the absence of preventive and corrective actions aiming to neutralize institutional, social and other stimuli facilitating criminalization of economic activities can result in large losses of financial assets in the form of mass capital flight

Shadow Globalization

Directory of Open Access Journals (Sweden)

Larissa Mihaylovna Kapitsa

2014-01-01

Full Text Available The article reviews some development trends brought about by globalization, particularly, a growing tax evasion and tax avoidance, an expansion of illicit financial flows and the proliferation of a global criminal network. The author draws attention to some new phenomena, particularly, cosmopolitanization of some parts of national elites and a deepening divide between national interests and the private interests of elites as a consequence of financial globalization. Modern mass media, both Russian and foreign, tend to interpret globalization processes exclusively from the position of conformism, and for some of the researchers globalization became the "sacred cow", which one may only worship. Critical analysis of the processes associated with globalization is given a hostile reception. In response to criticism of globalization, one can hear the very same argument: "globalization in inevitable!" Such a state of affairs, the very least, causes perplexity. Some of the world development trends been observed over the past years raise serious concerns about the security and welfare of the peoples of the world. One of such trends has been the globalization of shadow economic activities. Methods of fight against the criminal economy been applied in international practice can be grouped into: 1 punitive enforcement (or criminal-legal methods and 2 socio-economic methods. As the results of various research works evidence punitive enforcement methods not supported by socio-economic measures not effective enough. Toughening the control over criminal economic activities in the absence of preventive and corrective actions aiming to neutralize institutional, social and other stimuli facilitating criminalization of economic activities can result in large losses of financial assets in the form of mass capital flight

A trial of selective imaging for the breast mass shadow by computed radiography

International Nuclear Information System (INIS)

Muramatsu, Yukio; Anan, Mitsuhiro; Tanaka, Takashi; Matsue, Hiroto; Yamada, Tatsuya

1990-01-01

CR has ability to make many kinds of images by several imaging processings. Especially, gradation processing is more important than frequency processing to make images in CR mammography. We developed new method to image breast masses selectively with new gradation processing and tried it for 18 patients over sixty years old with breast cancer. All of breast mass shadows were separated selectively from other parencymal shadow. So, we conclude that the auto-recognition of breast mass shadow can be possible in near future in CR system. (author)

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 ...

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

On Risk Charges and Shadow Account Options in Pension Funds

DEFF Research Database (Denmark)

Jørgensen, Peter Løchte; Gatzert, Nadine

2015-01-01

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......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...... wealth. However, our analysis also shows that this risk can be remedied if proper attention is given to the specific contract design and to the fixing of fair contract parameters at the outset....

The Relationship between Shadow Economy and Unemployment Rate. A Ardl Causality Analysis for the Case Of Romania

Directory of Open Access Journals (Sweden)

Adriana AnaMaria DAVIDESCU

2015-12-01

Full Text Available The paper aims to investigate the nature of the relationship between the shadow economy (SE and unemployment rates (both registered and ILO for the case of Romania using Pesaran et al.(2001 bounds tests approach for cointegration. The study uses quarterly data covering the period 2000-2010. The size of Romanian shadow economy is estimated using the currency demand approach based on VECM models, stating that its size is decreasing over the analyzed period, from 36.5% at the end of 2000 to about 31.5% of real GDP at the middle of 2010. To investigate the long-run causal linkages and short-run dynamics between shadow economy and unemployment rate, ARDL cointegration approach is applied. Cointegration test results shows that in short-run both ILO and registered unemployment rate has a negative and statistically significant effect on the size of the shadow economy, while in the long-run the unemployment rates have a positive effect on shadow economy. The ARDL causality results revealed the existence of a long-run unidirectional causality that runs from unemployment rates (registered or ILO to shadow economy. In addition, the CUSUM and CUSUMSQ tests confirm the stability of the both causal relationships.

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

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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

Shadow Detection from Very High Resoluton Satellite Image Using Grabcut Segmentation and Ratio-Band Algorithms

Science.gov (United States)

Kadhim, N. M. S. M.; Mourshed, M.; Bray, M. T.

2015-03-01

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 significant performance of

Dose rate laser simulation tests adequacy: Shadowing and high intensity effects analysis

International Nuclear Information System (INIS)

Nikiforov, A.Y.; Skorobogatov, P.K.

1996-01-01

The adequacy of laser based simulation of the flash X-ray effects in microcircuits may be corrupted mainly due to laser radiation shadowing by the metallization and the non-linear absorption in a high intensity range. The numerical joint solution of the optical equations and the fundamental system of equations in a two-dimensional approximation were performed to adjust the application range of laser simulation. As a result the equivalent dose rate to laser intensity correspondence was established taking into account the shadowing as well as the high intensity effects. The simulation adequacy was verified in the range up to 4·10 11 rad(Si)/s with the comparative laser test of a specially designed test structure

Information Subsystem of Shadow Economy Deactivation

OpenAIRE

Filippova, Tatyana V.

2015-01-01

The article presents information subsystem of shadow economy deactivation aimed at minimizing negative effects caused by its reproduction. In Russia, as well as in other countries, efficient implementation of the suggested system of shadow economy deactivation can be ensured by the developed information subsystem.

Image research on acetabular teardrop shadow by X-ray plain-film and CT

International Nuclear Information System (INIS)

Wang Xiaoxuan; Zhai Yuejie; Yu Hongguang; Yang Yijun; Zhang Daiwei; Chen Aili; Song Quanjun

2001-01-01

Objective: To evaluate the anatomical structure of bone in the formation of acetabular teardrop shadow. Methods: The acetabular teardrop shadow of the X-ray plain-film in 100 children and 300 adults, and of CT in 43 cases were analysed, measured and compared. Results: In children, teardrop shadow appeared 'U' in 80.00%, 14.00% in teardrop, 6.00% in line. In adult teardrop shadow appeared 'U' in 41.33%, 53.33% in teardrop, 5.34% in line. There were significant differences between children and adult in the frequency of 'U' and teardrop (x 2 = 43.34, P 2 = 45.62, P < 0.01). In children, inpeduncle of teardrop shadow was formed of middle 1/3 substantia-line of acetabular concavity inside of pelvis; outpeduncle was formed of middle 1/3 substantia-line of bottom of acetabular. In adult, inpeduncle was formed of middle 1/3 or back 1/3 substantia line of acetabular concavity inside of pelvis; outpeduncle was formed of middle 1/3 or back 1/3 substantia-line of bottom of acetabular. Conclusion: In children, acetabular teardrop shadow was mainly formed of middle 1/3 bone of acetabular concavity. In adult, middle 1/3 or back 1/3 bone of acetabular concavity contribute to the shadow. The ahead 1/3 bone of acetabular concavity is not involved

An Overview on Base Real-Time Hard Shadow Techniques in Virtual Environments

Directory of Open Access Journals (Sweden)

Mohd Shahrizal Sunar

2012-03-01

Full Text Available Shadows are elegant to create a realistic scene in virtual environments variety type of shadow techniques encourage us to prepare an overview on all base shadow techniques. Non real-time and real-time techniques are big subdivision of shadow generation. In non real-time techniques ray tracing, ray casting and radiosity are well known and are described deeply. Radiosity is implemented to create very realistic shadow on non real-time scene. Although traditional radiosity algorithm is difficult to implement, we have proposed a simple one. The proposed pseudo code is easier to understand and implement. Ray tracing is used to prevent of collision of movement objects. Projection shadow, shadow volume and shadow mapping are used to create real-time shadow in virtual environments. We have used projection shadow for some objects are static and have shadow on flat surface. Shadow volume is used to create accurate shadow with sharp outline. Shadow mapping that is the base of most recently techniques is reconstructed. The reconstruct algorithm gives some new idea to propose another algorithm based on shadow mapping.

Shadowing of gluons in perturbative QCD: A comparison of different models

International Nuclear Information System (INIS)

Jalilian-Marian, Jamal; Wang, Xin-Nian

2001-01-01

We investigate the different perturbative QCD-based models for nuclear shadowing of gluons. We show that, in the kinematic region appropriate to the BNL relativistic heavy ion collider experiment, all models give similar estimates for the magnitude of gluon shadowing. At scales relevant to CERN large hadron collider (LHC), there is a sizable difference between the predictions of the different models. However, the uncertainties in gluon shadowing coming from a different parametrization of the gluon distribution in nucleons, are larger than those due to different perturbative QCD models of gluon shadowing. We also investigate the effect of initial nonperturbative shadowing on the magnitude of perturbative shadowing and show that the magnitudes of perturbative and nonperturbative shadowing are comparable at RHIC but perturbative shadowing dominates over nonperturbative shadowing at smaller values of x reached at LHC

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...

Control rod shadowing and anti-shadowing effects in a large gas-cooled fast reactor

International Nuclear Information System (INIS)

Girardin, G.; Chawla, R.; Rimpault, G.; Coddington, P.

2007-01-01

An investigation of control rod shadowing and anti-shadowing (interaction) effects has been carried out in the context of a design study of the control rod pattern for the large 2400 MWth Generation IV Gas-cooled Fast Reactor (GFR). For the calculations, the deterministic code system ERANOS-2.0 has been used, in association with a full core model including a European Fast Reactor (EFR)-type pattern for the control rods. More specifically, the core contains a total of 33 control (CSD) and safety (DSD) rods implemented in three banks: -1) a first bank of 6 CSD rods, placed at 64 cm from core centre in the inner fuel zone (Pu content 16.3 % vol.), -2) a safety bank consisting of 9 DSD rods, at an average distance of 118 cm, and -3) a third bank with 18 CSD rods, placed at 171 cm, i.e. at the interface between the inner and outer (Pu content 19.2 % vol.) core regions. Each control rod has been modelled as a homogeneous material containing 90%-enriched B 4 C, steel and helium. Considerable shadowing effects have been observed between the first bank and the safety bank, as also between individual rods within the first bank. Large anti-shadowing effects take place in an even greater number of the studied rod configurations. The largest interaction is between the two CSD banks, the anti-shadowing value being 46% in this case, implying that the total rod worth is increased by a factor of almost 2 when compared to the sum of the individual bank values. Additional investigations have been performed, in particular the computation of the first order eigenvalue and the eigenvalue separation. The main finding is that the interactions are lower when one of the control rod banks is located at a radial position corresponding to half the core radius. (authors)

Analytical estimation of control rod shadowing effect for excess reactivity measurement of HTTR

International Nuclear Information System (INIS)

Nakano, Masaaki; Fujimoto, Nozomu; Yamashita, Kiyonobu

1999-01-01

The fuel addition method is generally used for the excess reactivity measurement of the initial core. The control rod shadowing effect for the excess reactivity measurement has been estimated analytically for High Temperature Engineering Test Reactor (HTTR). 3-dimensional whole core analyses were carried out. The movements of control rods in measurements were simulated in the calculation. It was made clear that the value of excess reactivity strongly depend on combinations of measuring control rods and compensating control rods. The differences in excess reactivity between combinations come from the control rod shadowing effect. The shadowing effect is reduced by the use of plural number of measuring and compensating control rods to prevent deep insertion of them into the core. The measured excess reactivity in the experiments is, however, smaller than the estimated value with shadowing effect. (author)

Radioisotope imaging using gamma-ray shadow hologram

International Nuclear Information System (INIS)

Kojima, Kazuhiko; Itaya, Gensei; Hisada, Kin-ichi.

1975-01-01

Use of holography for the imaging of radioisotope distribution, reported by Barrett, H.H. in 1972, has been marked as a new γ-ray imaging. Generally, in optical fields, holography was often used for recording and processing three dimensional images by coherent waves such as laser beams. However, γ-rays are incoherent and are not condensed by optical lenses. So it was necessary that the holograms of incoherent sources were formed without optical lenses. A method which records the shadows of on axis zone plate with a Fresnnel diffraction pattern was used for obtaining an incoherent hologram. This method has the advantages of improved resolution and γ-ray detection efficiency, and also has a constitution of this system which is simple and economical. But, the disadvantage is, that the process consists of two steps, forming holograms and reconstructing images. The fundamental problems of γ-ray holograms and the practicabilities of γ-ray imaging of this method were discussed. In this system medical x-ray films combined with industrial intensifying screens were used as detectors, and γ-ray shadow holograms were obtained for about 3 minutes. From the shadow holograms, images were reconstructed, using a parallel laser beams, (He-Ne laser, single mode, 6328 A, 1mW). The zone plate consisted of coaxial lead rings with 10 open zones. The aperture area of this zone plate collimator was several hundreds times larger than the pinhole, so the detection efficiency, of γ-rays was improved. Using sup(99m)Tc 10 mCi as a γ-ray source, an attempt was made to image points, English characters and thyroid phantoms, and these reconstructed images were shown. An image resolution of 3-5 mm was obtained in the reconstructed image of an object at a distance of 10 cm from the collimator. (auth.)

What do the shadow rates tell us about future inflation?

OpenAIRE

Kuusela, Annika; Hännikäinen, Jari

2017-01-01

This paper investigates whether shadow interest rates contain predictive power for U.S. inflation in a data-rich environment. We find that shadow rates are useful leading indicators of inflation. Shadow rates contain substantial in-sample and out-of-sample predictive power for inflation in both the zero lower bound (ZLB) and non-ZLB periods. We find that the shadow rate suggested by Wu and Xia (2016) contains more information about future inflation than the shadow rate suggested by Krippner (...

Interconnectedness between shadow and traditional banking systems in Europe

Directory of Open Access Journals (Sweden)

Popović Svetlana

2017-01-01

Full Text Available The financial crisis that emerged in the US quickly spread across Europe, causing a severe banking and sovereign debt crisis. That revealed the importance of short-term financing for traditional banks, which increased their exposure to the financial conditions on the interbank market. Financial innovations, especially the securitization process led to the growing importance of different institutions within the shadow banking system - which undergo a credit, liquidity and maturity transformation, without accessing the central bank liquidity or other forms of guarantees. The European banks had an active role in the US securitization process, but also securitized the products from the European market. The authors used the available data from the ECB statistics on shadow bank entities, broadly and narrowly defined, in order to analyze the various measures of interconnectedness between the shadow and traditional banking systems. The analysis showed that non-regulated financial institutions pose severe systemic risks, not just because of their size, but also due to the strong web of interconnectedness with the regulated banking sector.

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.

PRECONDITIONS AND DETERMINING CAUSES OF THE SHADOW ECONOMY IN UKRAINE

Directory of Open Access Journals (Sweden)

Z. Varnalii

2014-03-01

Full Text Available The article analyzes the main processes that led to the high level of the economy shadowing. The historical aspects of the formation of the shadow economy in Ukraine are highlighted. The socio-economic aspects of the shadow economy of Ukraine causality are discussed. The theoretical contribution of foreign and domestic researchers on the preconditions of formation of the shadow economy in transition economies is studied. Theoretical perspective on the factors of the shadowing processes in the economy of Ukraine from the standpoint of modern scientific researches is analyzed. The paper also provides scientific vectors for further development of researches aimed at studying the causes and preconditions of the shadow economy.

Various appearances of rib companion shadow mimicking a pathologic condition

International Nuclear Information System (INIS)

Choi, Yo Won; Yoo, Shi Joon; Im, Jung Gil

1992-01-01

We have observed that the companion shadow of the upper rib may be misinterpreted as a small pneumothorax or pleural plaque associated with asbestosis. To observe the radiographic characteristics of the normal companion shadow, we analyzed, on the posteroanterior(PA) chest radiographs, the companion shadow of 50 normal cases. Factors such as occurrence on each rib, the sharpness of the margin, the relative position to the rib, the shape and the thickness were observed. Also, we analyzed the displaced pleura of 4 pneumothorax cases to differentiate their findings from the findings of normal companion shadows. On 50 normal chest radiographs, 192 companion shadows were observed on the first to fourth ribs. In 173 of those shadows, the visceral margin of the companion shadow on the second rib simulated pneumothorax more closely than those on any other ribs due to its apical location and thinness. In six of 50 normal cases, the companion shadow in the first or second rib showed an inwardly convex lower margin, mimicking pleural plaque. The companion shadow was suggested on the plain chest radiograph by the following characteristics imultiplicity (47/50), thicker than normal pleura (3/4), persistent on serial films with the same shape and specific location(4/4)

3D Spatial and Spectral Fusion of Terrestrial Hyperspectral Imagery and Lidar for Hyperspectral Image Shadow Restoration Applied to a Geologic Outcrop

Science.gov (United States)

Hartzell, P. J.; Glennie, C. L.; Hauser, D. L.; Okyay, U.; Khan, S.; Finnegan, D. C.

2016-12-01

Recent advances in remote sensing technology have expanded the acquisition and fusion of active lidar and passive hyperspectral imagery (HSI) from an exclusively airborne technique to terrestrial modalities. This enables high resolution 3D spatial and spectral quantification of vertical geologic structures for applications such as virtual 3D rock outcrop models for hydrocarbon reservoir analog analysis and mineral quantification in open pit mining environments. In contrast to airborne observation geometry, the vertical surfaces observed by horizontal-viewing terrestrial HSI sensors are prone to extensive topography-induced solar shadowing, which leads to reduced pixel classification accuracy or outright removal of shadowed pixels from analysis tasks. Using a precisely calibrated and registered offset cylindrical linear array camera model, we demonstrate the use of 3D lidar data for sub-pixel HSI shadow detection and the restoration of the shadowed pixel spectra via empirical methods that utilize illuminated and shadowed pixels of similar material composition. We further introduce a new HSI shadow restoration technique that leverages collocated backscattered lidar intensity, which is resistant to solar conditions, obtained by projecting the 3D lidar points through the HSI camera model into HSI pixel space. Using ratios derived from the overlapping lidar laser and HSI wavelengths, restored shadow pixel spectra are approximated using a simple scale factor. Simulations of multiple lidar wavelengths, i.e., multi-spectral lidar, indicate the potential for robust HSI spectral restoration that is independent of the complexity and costs associated with rigorous radiometric transfer models, which have yet to be developed for horizontal-viewing terrestrial HSI sensors. The spectral restoration performance is quantified through HSI pixel classification consistency between full sun and partial sun exposures of a single geologic outcrop.

Multiple shadows from distorted static black holes

Science.gov (United States)

Grover, Jai; Kunz, Jutta; Nedkova, Petya; Wittig, Alexander; Yazadjiev, Stoytcho

2018-04-01

We study the local shadow of the Schwarzschild black hole with a quadrupole distortion and the influence of the external gravitational field on the photon dynamics. The external matter sources modify the light ring structure and lead to the appearance of multiple shadow images. In the case of negative quadrupole moments we identify the most prominent mechanism causing multiple shadow formation. Furthermore, we obtain a condition under which this mechanism can be realized. This condition depends on the quadrupole moment, but also on the position of the observer and the celestial sphere.

SHADOW BANKING - A Geographical Interpretation

OpenAIRE

Gianfranco Battisti

2014-01-01

Basically, shadow banking is an original kind of business organization, or better a set of institutions and markets, finalized to disinvest fixed assets and convey them to the financial markets. Nowadays, tackling the subject means penetrating the hard core of financialization. Shadow banking manifests itself through a variety of activities carried out since time immemorial. Some authors go back to the 17th century, but certain procedures and entire phases were established well before the ins...

Devaney chaos plus shadowing implies distributional chaos.

Science.gov (United States)

Li, Jian; Li, Jie; Tu, Siming

2016-09-01

We explore connections among the regional proximal relation, the asymptotic relation, and the distal relation for a topological dynamical system with the shadowing property and show that if a Devaney chaotic system has the shadowing property then it is distributionally chaotic.

Illumination robust face recognition using spatial adaptive shadow compensation based on face intensity prior

Science.gov (United States)

Hsieh, Cheng-Ta; Huang, Kae-Horng; Lee, Chang-Hsing; Han, Chin-Chuan; Fan, Kuo-Chin

2017-12-01

Robust face recognition under illumination variations is an important and challenging task in a face recognition system, particularly for face recognition in the wild. In this paper, a face image preprocessing approach, called spatial adaptive shadow compensation (SASC), is proposed to eliminate shadows in the face image due to different lighting directions. First, spatial adaptive histogram equalization (SAHE), which uses face intensity prior model, is proposed to enhance the contrast of each local face region without generating visible noises in smooth face areas. Adaptive shadow compensation (ASC), which performs shadow compensation in each local image block, is then used to produce a wellcompensated face image appropriate for face feature extraction and recognition. Finally, null-space linear discriminant analysis (NLDA) is employed to extract discriminant features from SASC compensated images. Experiments performed on the Yale B, Yale B extended, and CMU PIE face databases have shown that the proposed SASC always yields the best face recognition accuracy. That is, SASC is more robust to face recognition under illumination variations than other shadow compensation approaches.

The multisensory body revealed through its cast shadows.

Science.gov (United States)

Pavani, Francesco; Galfano, Giovanni

2015-01-01

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.

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.

Applications of a shadow camera system for energy meteorology

Science.gov (United States)

Kuhn, Pascal; Wilbert, Stefan; Prahl, Christoph; Garsche, Dominik; Schüler, David; Haase, Thomas; Ramirez, Lourdes; Zarzalejo, Luis; Meyer, Angela; Blanc, Philippe; Pitz-Paal, Robert

2018-02-01

Downward-facing shadow cameras might play a major role in future energy meteorology. Shadow cameras directly image shadows on the ground from an elevated position. They are used to validate other systems (e.g. all-sky imager based nowcasting systems, cloud speed sensors or satellite forecasts) and can potentially provide short term forecasts for solar power plants. Such forecasts are needed for electricity grids with high penetrations of renewable energy and can help to optimize plant operations. In this publication, two key applications of shadow cameras are briefly presented.

Preliminary results of the Moon shadow using ARGO-YBJ detector

Energy Technology Data Exchange (ETDEWEB)

Wang Yungang [Institute of High Energy Physics, Chinese Academy of Sciences 19B Yuquan Lu, Shijingshan, Beijing, 100049 (China)], E-mail: wangyg@mail.ihep.ac.cn

2008-01-15

ARGO-YBJ is a 'full coverage' air shower detector consisting of Resistive Plate Chambers(RPCs) at the Yangbajing High Altitude Cosmic Ray Laboratory (Tibet, China) at 4300 m a.s.l. (lat=30.11{sup o} N, long=90.53{sup o} E). Using the data collected with a carpet of RPCs (1900 m{sup 2}, about 1/3 of the whole ARGO-YBJ detector), the cosmic ray shadowing effect due to the Moon was studied. The 50% angular resolution is found to be {approx}1.2{sup o} with the Chess-board method and the Moon shadow with a significance of 4.9 {sigma} is found displaced by 0.7{sup o} westward and 0.5{sup o} northward with respect to the expected position by the equi-zenith angle Method.

Shadow corrosion phenomenon. An out-of-pile study on electrochemical effects

Energy Technology Data Exchange (ETDEWEB)

Weber, Nadine

2017-04-28

The focus of the present thesis was the study of the enhanced corrosion phenomenon named ''Shadow Corrosion''. Within the context of researching based on the corrosion mechanism as well as the influencing parameters and driving forces, which cause or even intensify the corrosion, a variety of electrochemical characterization and surface analysis techniques were used. The first part of this thesis gives a short introduction with the definition of the term Shadow Corrosion and of the specific type called ''Enhanced Spacer Shadow Corrosion'' (ESSC). This is followed by a description of the involved materials being Zircaloy and Inconel 718. Chapter 2 introduces the background knowledge including fundamentals about environ-mental conditions under which Shadow Corrosion occurs as well as the oxidation behavior of Zircaloy and Inconel 718. Furthermore, the state of the art about the Shadow Corrosion mechanism is presented and a description of the influencing effects on the enhanced corrosion phenomenon, like galvanic corrosion, water radiolysis, and photo-effect, is given. Further information and parameters on the part of AREVA GmbH concerning water impurities and a used coating layer on Inconel 718 are listed, which are of interest for the issue concerning the phenomenon Shadow Corrosion. The last part of this chapter contains the experimental conditions and parameters for the laboratory experiments with focus on water chemistry, specimen geometry, and UV-light exposure for photoexcitation and water radiolysis. Three different working hypotheses of this thesis are described in chapter 3. One hypothesis regarding the Shadow Corrosion Phenomenon is based on a galvanic corrosion mechanism between Zircaloy and Inconel 718. In addition, it is supposed that the galvanic corrosion could be influenced by the deposition of silver on Zircaloy and Inconel 718 in the form of an increased galvanic current. A further assumption is that the

Shadow corrosion phenomenon. An out-of-pile study on electrochemical effects

International Nuclear Information System (INIS)

Weber, Nadine

2017-01-01

The focus of the present thesis was the study of the enhanced corrosion phenomenon named ''Shadow Corrosion''. Within the context of researching based on the corrosion mechanism as well as the influencing parameters and driving forces, which cause or even intensify the corrosion, a variety of electrochemical characterization and surface analysis techniques were used. The first part of this thesis gives a short introduction with the definition of the term Shadow Corrosion and of the specific type called ''Enhanced Spacer Shadow Corrosion'' (ESSC). This is followed by a description of the involved materials being Zircaloy and Inconel 718. Chapter 2 introduces the background knowledge including fundamentals about environ-mental conditions under which Shadow Corrosion occurs as well as the oxidation behavior of Zircaloy and Inconel 718. Furthermore, the state of the art about the Shadow Corrosion mechanism is presented and a description of the influencing effects on the enhanced corrosion phenomenon, like galvanic corrosion, water radiolysis, and photo-effect, is given. Further information and parameters on the part of AREVA GmbH concerning water impurities and a used coating layer on Inconel 718 are listed, which are of interest for the issue concerning the phenomenon Shadow Corrosion. The last part of this chapter contains the experimental conditions and parameters for the laboratory experiments with focus on water chemistry, specimen geometry, and UV-light exposure for photoexcitation and water radiolysis. Three different working hypotheses of this thesis are described in chapter 3. One hypothesis regarding the Shadow Corrosion Phenomenon is based on a galvanic corrosion mechanism between Zircaloy and Inconel 718. In addition, it is supposed that the galvanic corrosion could be influenced by the deposition of silver on Zircaloy and Inconel 718 in the form of an increased galvanic current. A further assumption is that the galvanic current could be decreased by a Cr

Automatic shadowing device for electron microscopy

Energy Technology Data Exchange (ETDEWEB)

Bishop, F W; Bogitch, S

1960-01-01

For the past ten years in the laboratory of the Department of Nuclear Medicine and Radiation Biology at the University of California, and before that at Rochester, New York, every evaporation was done with the aid of an automatic shadowing device. For several months the automatic shadowing device has been available at the Atomic Bomb Casualty Commission (ABCC) Hiroshima, Japan with the modifications described. 1 reference.

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...

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.

An Efficient and Robust Moving Shadow Removal Algorithm and Its Applications in ITS

Directory of Open Access Journals (Sweden)

Shou Yu-Wen

2010-01-01

Full Text Available We propose an efficient algorithm for removing shadows of moving vehicles caused by non-uniform distributions of light reflections in the daytime. This paper presents a brand-new and complete structure in feature combination as well as analysis for orientating and labeling moving shadows so as to extract the defined objects in foregrounds more easily in each snapshot of the original files of videos which are acquired in the real traffic situations. Moreover, we make use of Gaussian Mixture Model (GMM for background removal and detection of moving shadows in our tested images, and define two indices for characterizing non-shadowed regions where one indicates the characteristics of lines and the other index can be characterized by the information in gray scales of images which helps us to build a newly defined set of darkening ratios (modified darkening factors based on Gaussian models. To prove the effectiveness of our moving shadow algorithm, we carry it out with a practical application of traffic flow detection in ITS (Intelligent Transportation System—vehicle counting. Our algorithm shows the faster processing speed, 13.84 ms/frame, and can improve the accuracy rate in 4%~10% for our three tested videos in the experimental results of vehicle counting.

Shadow casted by a Konoplya-Zhidenko rotating non-Kerr black hole

Energy Technology Data Exchange (ETDEWEB)

Wang, Mingzhi; Chen, Songbai; Jing, Jiliang, E-mail: wmz9085@126.com, E-mail: csb3752@hunnu.edu.cn, E-mail: jljing@hunnu.edu.cn [Institute of Physics and Department of Physics, Hunan Normal University, Changsha, Hunan 410081 (China)

2017-10-01

We have investigated the shadow of a Konoplya-Zhidenko rotating non-Kerr black hole with an extra deformation parameter. The spacetime structure arising from the deformed parameter affects sharply the black hole shadow. With the increase of the deformation parameter, the size of the shadow of black hole increase and its shape becomes more rounded for arbitrary rotation parameter. The D-shape shadow of black hole emerges only in the case a <2√3/3\\, M with the proper deformation parameter. Especially, the black hole shadow possesses a cusp shape with small eye lashes in the cases with a >M, and the shadow becomes less cuspidal with the increase of the deformation parameter. Our result show that the presence of the deformation parameter yields a series of significant patterns for the shadow casted by a Konoplya-Zhidenko rotating non-Kerr black hole.

Creating cloud-free Landsat ETM+ data sets in tropical landscapes: cloud and cloud-shadow removal

Science.gov (United States)

Sebastián Martinuzzi; William A. Gould; Olga M. Ramos Gonzalez

2007-01-01

Clouds and cloud shadows are common features of visible and infrared remotelysensed images collected from many parts of the world, particularly in humid and tropical regions. We have developed a simple and semiautomated method to mask clouds and shadows in Landsat ETM+ imagery, and have developed a recent cloud-free composite of multitemporal images for Puerto Rico and...

Shadowing in the scaling region

International Nuclear Information System (INIS)

Shaw, G.

1989-01-01

The approximate scaling behaviour of the shadowing effect at small χ, recently observed in deep inelastic muon scattering experiments on nuclei, is shown to arise naturally at very large ν in those hadron dominance models, formulated many years ago, which are dual to the parton model. At smaller ν small scale breaking effects are expected, which sould die away as ν increases. The predicted shadowing decreases rapidly with increasing χ, at a rate which is only weakly dependent on the atomic number A for reasonably large A. (orig.)

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.

Doctoring Undercover: updating the educational tradition of shadowing.

Science.gov (United States)

Clark, Claire D

2017-01-01

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. 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. 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. 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 conducted. ICM: Introduction to Clinical Medicine; SCE: Selective Clinical

Automated Detection of Cloud and Cloud Shadow in Single-Date Landsat Imagery Using Neural Networks and Spatial Post-Processing

Directory of Open Access Journals (Sweden)

M. Joseph Hughes

2014-05-01

Full Text Available The use of Landsat data to answer ecological questions is greatly increased by the effective removal of cloud and cloud shadow from satellite images. We develop a novel algorithm to identify and classify clouds and cloud shadow, SPARCS: Spatial Procedures for Automated Removal of Cloud and Shadow. The method uses a neural network approach to determine cloud, cloud shadow, water, snow/ice and clear sky classification memberships of each pixel in a Landsat scene. It then applies a series of spatial procedures to resolve pixels with ambiguous membership by using information, such as the membership values of neighboring pixels and an estimate of cloud shadow locations from cloud and solar geometry. In a comparison with FMask, a high-quality cloud and cloud shadow classification algorithm currently available, SPARCS performs favorably, with substantially lower omission errors for cloud shadow (8.0% and 3.2%, only slightly higher omission errors for clouds (0.9% and 1.3%, respectively and fewer errors of commission (2.6% and 0.3%. Additionally, SPARCS provides a measure of uncertainty in its classification that can be exploited by other algorithms that require clear sky pixels. To illustrate this, we present an application that constructs obstruction-free composites of images acquired on different dates in support of a method for vegetation change detection.

Light-cone gauge approach to arbitrary spin fields, currents and shadows

International Nuclear Information System (INIS)

Metsaev, R R

2014-01-01

Totally symmetric arbitrary spin fields in AdS space, conformal fields, conformal currents, and shadow fields in flat space are studied. Light-cone gauge formulations for such fields, currents and shadows are obtained. Use of the Poincaré parametrization of AdS space and ladder operators allows us to treat fields in flat and AdS spaces on an equal footing. Light-cone gauge realization of relativistic symmetries for fields, currents and shadows is also obtained. The light-cone gauge formulation for fields is obtained by using the gauge invariant Lagrangian which is presented in terms of modified de Donder divergence, while the light-cone gauge formulation for currents and shadows is obtained by using the gauge invariant approach to currents and shadows. This allows us to demonstrate explicitly how the ladder operators entering the gauge invariant formulation of fields, currents and shadows manifest themselves in the light-cone gauge formulation for fields, currents and shadows. (paper)

Measuring the residual stress of transparent conductive oxide films on PET by the double-beam shadow Moiré interferometer

Science.gov (United States)

Chen, Hsi-Chao; Huang, Kuo-Ting; Lo, Yen-Ming; Chiu, Hsuan-Yi; Chen, Guan-Jhen

2011-09-01

The purpose of this research was to construct a measurement system which can fast and accurately analyze the residual stress of the flexible electronics. The transparent conductive oxide (TCO) films, tin-doped indium oxide (ITO), were deposited by radio frequency (RF) magnetron sputtering using corresponding oxide targets on PET substrate. As we know that the shadow Moiré interferometry is a useable way to measure the large deformation. So we set up a double beam shadow Moiré interferometer to measure and analyze the residual stress of TCO films on PET. The feature was to develop a mathematical model and combine the image processing software. By the LabVIEW graphical software, we could measure the distance which is between the left and right fringe on the pattern to solve the curvature of deformed surface. Hence, the residual stress could calculate by the Stoney correction formula for the flexible electronics. By combining phase shifting method with shadow Moiré, the measurement resolution and accuracy have been greatly improved. We also had done the error analysis for the system whose relative error could be about 2%. Therefore, shadow Moiré interferometer is a non-destructive, fast, and simple system for the residual stress on TCO/PET films.

How do Institutions Affect Corruption and the Shadow Economy?

OpenAIRE

Axel Dreher; Christos Kotsogiannis; Steve McCorriston

2005-01-01

This paper analyzes a simple model that captures the relationship between institutional quality, the shadow economy and corruption. It shows that an improvement in institutional quality reduces the shadow economy and affects the corruption market. The exact relationship between corruption and institutional quality is, however, ambiguous and depends on the relative effectiveness of the institutional quality in the shadow and corruption markets. The predictions of the model are empirically test...

Resonance integral analytical calculation considering shadowing effect

International Nuclear Information System (INIS)

Monteiro, M.A.M.; Martinez, A.S.

1990-01-01

It is presented a method for the Resonance Integral Calculation in the fuel and moderator regions, including the shadowing effect. This effect appears due to the presence of several fuel rods in a infinite moderator region. The method is based on the approximations to the J (ξ, β) function and theirs partial derivatives in relation to β. The dependence of the Resonance Integral in the J (ξ, β) comes from the rational approximation to the neutron escape probability. The final results were obtained in a very simple and fast way, and they show the good accuracy of the method. (author)

Does the black hole shadow probe the event horizon geometry?

Science.gov (United States)

Cunha, Pedro V. P.; Herdeiro, Carlos A. R.; Rodriguez, Maria J.

2018-04-01

There is an exciting prospect of obtaining the shadow of astrophysical black holes (BHs) in the near future with the Event Horizon Telescope. As a matter of principle, this justifies asking how much one can learn about the BH horizon itself from such a measurement. Since the shadow is determined by a set of special photon orbits, rather than horizon properties, it is possible that different horizon geometries yield similar shadows. One may then ask how sensitive is the shadow to details of the horizon geometry? As a case study, we consider the double Schwarzschild BH and analyze the impact on the lensing and shadows of the conical singularity that holds the two BHs in equilibrium—herein taken to be a strut along the symmetry axis in between the two BHs. Whereas the conical singularity induces a discontinuity of the scattering angle of photons, clearly visible in the lensing patterns along the direction of the strut's location, it produces no observable effect on the shadows, whose edges remain everywhere smooth. The latter feature is illustrated by examples including both equal and unequal mass BHs. This smoothness contrasts with the intrinsic geometry of the (spatial sections of the) horizon of these BHs, which is not smooth, and provides a sharp example on how BH shadows are insensitive to some horizon geometry details. This observation, moreover, suggests that for the study of their shadows, this static double BH system may be an informative proxy for a dynamical binary.

An example of a vector field with the oriented shadowing property

OpenAIRE

Tikhomirov, Sergey

2014-01-01

We consider shadowing properties for vector fields corresponding to different type of reparametrisations. We give an example of a vector field which has the oriented shadowing properties, but does not have the standard shadowing property.

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.

Shadowing in electroproduction

Energy Technology Data Exchange (ETDEWEB)

Vilela Mendes, R; Leao, J P [Instituto de Fisica e Matematica, Av. Gama Pinto 2, Lisbon 4 (Portugal)

1977-09-01

The notorious absence of shadowing effects in electroproduction may have either a deep dynamical origin or a very simple geometrical one. We argue in favour of a simple origin for this effect, having to do with the geometrical nature of the source that generates the virtual photons in electroproduction.

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.

Transmit antenna selection based on shadowing side information

KAUST Repository

Yilmaz, Ferkan; Yilmaz, Ahmet Oǧuz; Alouini, Mohamed-Slim; Kucur, Oǧuz

2011-01-01

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.

Theory of Jovian shadow bursts

Energy Technology Data Exchange (ETDEWEB)

Gopalswamy, N

1986-06-01

The shadow events in the dynamic spectra of Jovian decametric emission are explained as the result of interaction between electron bunches responsible for S and L emissions. The relevant dispersion relation is derived for the fast extraordinary mode in the cold magnetospheric plasma in the presence of S and L electron bunches. The growth rate of the synchrotron maser instability is studied in the presence and absence of S-electrons. It is shown that the synchrotron maser instability responsible for L-emission can be temporarily quenched by the invasion of S-electrons, thereby stopping the L-emission. The theory accounts for various observed features of the shadow events. (Auth.).

Monitoring of Shadow Cash Flows Using Computer Modelling

Directory of Open Access Journals (Sweden)

Evgeniya Vladimirovna Baturina

2018-03-01

Full Text Available The computer simulation of economic systems is a promising tool in the development of the theory of the country’s economic security. We have examined the Russian banking legislation and synthesized judicial economic expertise. This has allowed to develop an algorithm for the investigation of the marker pattern of shadow cash flows. The authors’ algorithm of marker monitoring of cash flow consists of the following sequences. Firstly, we set the time of the first receipt of money and the first withdrawals. Secondly, we compare cash balance of an organization at the beginning of the period with the first withdrawals. Thirdly, under the given condition, the minimum value of interested money flow in these withdrawals is calculated. This value is characterized by the marker parameters and forms a table containing data on the cash flow, recipients and payers, spheres of their activity. And last, on the basis of this table, we build a graph of relationships between the subjects of the shadow economy. The graph’s vertices represent these subjects. The visual representation of the graph is a marker pattern of shadow cash flow. The practical importance of this algorithm is due to its applicability in the investigation of economic crimes both at the stage of intelligence operations, and when obtaining proofs of the brought criminal cases in the form of the conclusions of expertseconomists. In addition, marker patterns of shadow cash flows can describe the state of the shadow economy of a region as a whole including its dynamics. This expands its parameterization. The created database of the shadow flows of the economy can be also useful for the scientific community. On the basis of the received results, we have developed management decisions to create and administer the information resource of the Bank of Russia “Shadow economy of a region”. This information resource ensures tracking the marker trace of cash flow in the bank environment by the

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

The stress shadow induced by the 1975-1984 Krafla rifting episode

KAUST Repository

Maccaferri, F.; Rivalta, E.; Passarelli, L.; Jonsson, Sigurjon

2013-01-01

of several magnitude 6–7 earthquakes. This compelling case of the existence of a stress shadow has never been studied in detail, and the implications of such a stress shadow remain an open question. According to rate-state models, intense stress shadows cause

Assessment of multipath and shadowing effects on UHF band in ...

African Journals Online (AJOL)

In this work, the multi-path and shadowing effects on signal impairment were investigated through the use of empirical and semi-empirical path loss models analysis in built-up environments. Electromagnetic field strength measurements were conducted using four television transmitters at UHF bands along four major routes ...

Reanalysing children's responses on shadow formation: a comparative approach to bodily expressions and verbal discourse

Science.gov (United States)

Pantidos, Panagiotis; Herakleioti, Evagelia; Chachlioutaki, Maria-Eleni

2017-12-01

The present article contains a reanalysis of data resulting from a research project carried out on a group of five preschool-aged children. The data were collected from a class of 16 children participating in a pre/post research design that focused on the shadow formation phenomenon. The findings of the previous research project, based on a speech plus deictic gesture analysis, indicated that the five children had shown regression or no change in their reasoning. In the light of an embodied perspective into science teaching and learning, the current study examines whether we should use a bodily analysis to reassess the extent of knowledge about shadows among these five students. It demonstrates that most of the children selected improved their reasoning about shadow formation by using iconic gestures. Such conflicting results indicate that bodily expression has its own grammar and, to some extent, communicates a meaning that differs from that of verbal discourse.

Fabrication of Josephson Junction without shadow evaporation

Science.gov (United States)

Wu, Xian; Ku, Hsiangsheng; Long, Junling; Pappas, David

We developed a new method of fabricating Josephson Junction (Al/AlOX/Al) without shadow evaporation. Statistics from room temperature junction resistance and measurement of qubits are presented. Unlike the traditional ``Dolan Bridge'' technique, this method requires two individual lithographies and straight evaporations of Al. Argon RF plasma is used to remove native AlOX after the first evaporation, followed by oxidation and second Al evaporation. Junction resistance measured at room temperature shows linear dependence on Pox (oxidation pressure), √{tox} (oxidation time), and inverse proportional to junction area. We have seen 100% yield of qubits made with this method. This method is promising because it eliminates angle dependence during Junction fabrication, facilitates large scale qubits fabrication.

Experimental test of the shadowing effect in Smith-Purcell radiation

International Nuclear Information System (INIS)

Naumenko, G.A.; Potylitsyn, A.P.; Popov, Yu.A.; Shevelev, M.V

2011-01-01

The observation of a shadowing effect of a relativistic electron Coulomb field for the Smith-Purcell radiation generation is presented in this paper. For this purpose the surface current from the closest surface of grating element to the electron beam was measured for a downstream one shadowed by upstream element. The experimental results showed that shadowing effect for Smith-Purcell radiation depends on grating geometry.

A hardware architecture for real-time shadow removal in high-contrast video

Science.gov (United States)

Verdugo, Pablo; Pezoa, Jorge E.; Figueroa, Miguel

2017-09-01

Broadcasting an outdoor sports event at daytime is a challenging task due to the high contrast that exists between areas in the shadow and light conditions within the same scene. Commercial cameras typically do not handle the high dynamic range of such scenes in a proper manner, resulting in broadcast streams with very little shadow detail. We propose a hardware architecture for real-time shadow removal in high-resolution video, which reduces the shadow effect and simultaneously improves shadow details. The algorithm operates only on the shadow portions of each video frame, thus improving the results and producing more realistic images than algorithms that operate on the entire frame, such as simplified Retinex and histogram shifting. The architecture receives an input in the RGB color space, transforms it into the YIQ space, and uses color information from both spaces to produce a mask of the shadow areas present in the image. The mask is then filtered using a connected components algorithm to eliminate false positives and negatives. The hardware uses pixel information at the edges of the mask to estimate the illumination ratio between light and shadow in the image, which is then used to correct the shadow area. Our prototype implementation simultaneously processes up to 7 video streams of 1920×1080 pixels at 60 frames per second on a Xilinx Kintex-7 XC7K325T FPGA.

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.

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...

Chromatic Shadow Detection and Tracking for Moving Foreground Segmentation

DEFF Research Database (Denmark)

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

2015-01-01

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...

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.

STUDY ON SHADOW EFFECTS OF VARIOUS FEATURES ON CLOSE RANGE THERMAL IMAGES

Directory of Open Access Journals (Sweden)

C. L. Liao

2012-07-01

Full Text Available Thermal infrared data become more popular in remote sensing investigation, for it could be acquired both in day and night. The change of temperature has special characteristic in natural environment, so the thermal infrared images could be used in monitoring volcanic landform, the urban development, and disaster prevention. Heat shadow is formed by reflecting radiating capacity which followed the objects. Because of poor spatial resolution of thermal infrared images in satellite sensor, shadow effects were usually ignored. This research focus on discussing the shadow effects of various features, which include metals and nonmetallic materials. An area-based thermal sensor, FLIR-T360 was selected to acquire thermal images. Various features with different emissivity were chosen as reflective surface to obtain thermal shadow in normal atmospheric temperature. Experiments found that the shadow effects depend on the distance between sensors and features, depression angle, object temperature and emissivity of reflective surface. The causes of shadow effects have been altered in the experiment for analyzing the variance in thermal infrared images. The result shows that there were quite different impacts by shadow effects between metals and nonmetallic materials. The further research would be produced a math model to describe the shadow effects of different features in the future work.

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

Determinants of the Shadow Economy in the Czech Regions: A Region-Level Study

Directory of Open Access Journals (Sweden)

Buček Jakub

2017-09-01

Full Text Available This paper investigates the size and development of the shadow economy in the Czech Republic on the state-level base over the 2005-2014 period. The multiple indicators multiple causes (MIMIC model is used to assess the estimation of the shadow economy size. I investigate how labour market, number of people with at least one distraint, and the burden of taxation might contribute to the existence of the shadow economy. While the former two are important determinants of the shadow economy, I find no evidence to prove any significant impact of distraints on the shadow economy size. As for the country’s particular regions, I find that those surrounding big cities, especially Prague, have, on average, a smaller shadow economy size, whereas regions in the borderlands (former Sudetenland suffer from a larger shadow economy.

Abnormal chest shadow on CT in immunosuppressed patients

International Nuclear Information System (INIS)

Tanaka, Nobuyuki; Matsumoto, Tsuneo; Nakamura, Hiroshi

1992-01-01

An abnormal chest shadow was observed on CT scans in 25 cases of 23 immunosuppressed patients. Pulmonary disease was pathologically confirmed to be pneumocystis carinii pneumonia (PC pneumonia) in four patients, cytomegalovirus pneumonia (CMV pneumonia) in one, bacterial pneumonia in seven, fungal infection in three, miliary tuberculosis in one, leukemic infiltration in two, lymphangitis carcinomatosa in three, drug-induced pneumonitis in three, and ARDS in one. In almost all patients, especially those with infectious diseases such as PC pneumonia, CMV pneumonia, and bacterial pneumonia, the abnormal shadow was wide and visible in the bilateral lung fields. We presumed that such findings as lobular shadow, centrilobular shadow, and mosaic pattern reflected the extension of disease via the respiratory tract, and that those findings are typical of infectious diseases. Because such findings as abnormal linear shadow and swelling of a broncho-vascular bundle were very frequently recognized in patients with lymphangitis carcinomatosa and frequently recognized in those with drug-induced pneumonitis, these diseases may be distinguished from other diseases. An area of slightly increased density was frequently recognized in patients with PC pneumonia, bacterial pneumonia, and drug-induced pneumonitis. Such lesions were pathologically confirmed to be located in the interstitium and/or alveolus. CT was extremely useful in comprehending the character and extension of particular diseases among various diseases. As the number of patients studied was small, the utility of CT in immunosuppressed patients requires further investigation in a larger number of patients. (author)

Studying Practices of Leading--Qualitative Shadowing in Early Childhood Research

Science.gov (United States)

Hognestad, Karin; Bøe, Marit

2016-01-01

This article considers qualitative shadowing as a fruitful method to investigate leadership practices. We propose that an approach to practice that takes into account the activities of "sayings, doings and relatings" offers a fresh perspective on how to obtain rich data on practices of leading. The value of this idea is illustrated from…

Shadow Replication: An Energy-Aware, Fault-Tolerant Computational Model for Green Cloud Computing

Directory of Open Access Journals (Sweden)

Xiaolong Cui

2014-08-01

Full Text Available As the demand for cloud computing continues to increase, cloud service providers face the daunting challenge to meet the negotiated SLA agreement, in terms of reliability and timely performance, while achieving cost-effectiveness. This challenge is increasingly compounded by the increasing likelihood of failure in large-scale clouds and the rising impact of energy consumption and CO2 emission on the environment. This paper proposes Shadow Replication, a novel fault-tolerance model for cloud computing, which seamlessly addresses failure at scale, while minimizing energy consumption and reducing its impact on the environment. The basic tenet of the model is to associate a suite of shadow processes to execute concurrently with the main process, but initially at a much reduced execution speed, to overcome failures as they occur. Two computationally-feasible schemes are proposed to achieve Shadow Replication. A performance evaluation framework is developed to analyze these schemes and compare their performance to traditional replication-based fault tolerance methods, focusing on the inherent tradeoff between fault tolerance, the specified SLA and profit maximization. The results show that Shadow Replication leads to significant energy reduction, and is better suited for compute-intensive execution models, where up to 30% more profit increase can be achieved due to reduced energy consumption.

"JOB SEEKER"(Job Shadowing for Employee Engagement through Knowledge and Experience Retention).

Science.gov (United States)

2016-05-01

The main objective of this study was to explore how to optimally use the particular knowledge : retention/transfer technique of job shadowing as an informal method for knowledge capture and : transfer as well as increasing communication and emp...

Market Pressure on Currencies in Crises. Shadow Exchange Rate Experience of Argentina and Switzerland 2011-2015

Directory of Open Access Journals (Sweden)

Marcin Gruszczyński

2017-10-01

Full Text Available Aim/purpose - The aim of this article is to present two cases of exchange rate controls in Switzerland and Argentina. The paper also examines the problem of presence and evaluation of shadow exchange rate in both countries. Design/methodology/approach - The shadow exchange rates are estimated using speculative pressure index concept that emphasizes the importance of not only exchange rate movements but also changes in foreign exchange reserves as well as interest rate differentials. The research sample covers Switzerland 2001-2016 and Argentina 2006-2016 (for shadow exchange rate simulation: 2011-2014 and 2011-2015, respectively. Findings - The conclusions drawn from international experience and conducted empirical analysis are positive. In both cases, shadow exchange rates were close to market rates after the removal of controls. During the restrictions periods shadow rates followed the intuition given by speculative pressure index concept (and by monetary approach, simultaneously. Research implications/limitations - The research suggests that market forces in both countries were still able to restore exchange rates to market values after the period of control. However, it is obvious that it is very difficult to prove that shadow rates were always determined by economical forces and close to their long-term equilibrium values. Originality/value/contribution - The original approach combines two important economic concepts - the idea of shadow exchange rate and the methodology of index of speculative pressure. Combined together they can help to analyze two interesting and relatively new cases of foreign exchange controls in Switzerland and Argentina. The results can be valuable for economists, researchers and politicians who support or reject the idea of controlling macroeconomic parameters in modern, open economy.

Does body shadow improve the efficacy of virtual reality-based training with BTS NIRVANA?

Science.gov (United States)

Russo, Margherita; De Luca, Rosaria; Naro, Antonino; Sciarrone, Francesca; Aragona, Bianca; Silvestri, Giuseppe; Manuli, Alfredo; Bramanti, Alessia; Casella, Carmela; Bramanti, Placido; Calabrò, Rocco Salvatore

2017-01-01

Abstract Background: Aim of the present study was to evaluate whether the presence of body shadows during virtual reality (VR) training with BTS NIRVANA (BTs-N) may lead to a better functional recovery. Methods: We enrolled 20 poststroke rehabilitation inpatients, who underwent a neurocognitive-rehabilitative training consisting of 24 sessions (3 times a week for 8 weeks) of BTs-N. All the patients were randomized into 2 groups: semi-immersive virtual training with (S-IVTS group) or without (S-IVT group) body shadows. Each participant was evaluated before (T0) and immediately (T1) after the end of the training (Trial Registration Number: NCT03095560). Results: The S-IVTS group showed a greater improvement in visuo-constructive skills and sustained attention, as compared with the S-IVT group. The other measures showed nonsignificant within-group and between-group differences. Conclusion: Our results showed that body shadow may represent a high-priority class of stimuli that act by “pushing” attention toward the body itself. Further studies are needed to clarify the role of body shadow in promoting the internal representation construction and thus self-recognition. PMID:28930852

A novel micromachined shadow mask system with self-alignment and gap control capability

International Nuclear Information System (INIS)

Hong, Jung Moo; Zou Jun

2008-01-01

We present a novel micromachined shadow mask system, which is capable of accurate self-alignment and mask-substrate gap control. The shadow mask system consists of a silicon shadow mask and a silicon carrier wafer with pyramidal cavities fabricated with bulk micromachining. Self-alignment and gap control of the shadow mask and the fabrication substrate can readily be achieved by using matching pairs of pyramidal cavities and steel spheres placed between. The layer-to-layer alignment accuracy of the new shadow mask system has been experimentally characterized and verified using both optical and atomic force microscopic measurements. As an application of this new shadow mask system, an organic thin-film transistor (OTFT) using pentacene as the semiconductor layer has been successfully fabricated and tested

Event horizon image within black hole shadow

OpenAIRE

Dokuchaev, V. I.; Nazarova, N. O.

2018-01-01

The external border of the black hole shadow is washed out by radiation from matter plunging into black hole and approaching the event horizon. This effect will crucially influence the results of future observations by the Event Horizon Telescope. We show that gravitational lensing of the luminous matter plunging into black hole provides the event horizon visualization within black hole shadow. The lensed image of the event horizon is formed by the last highly red-shifted photons emitted by t...

Effect of shadow economy - country's tax losses

OpenAIRE

Krumplytė, Jolita

2009-01-01

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 t...

Clustered deep shadow maps for integrated polyhedral and volume rendering

KAUST Repository

Bornik, Alexander; Knecht, Wolfgang; Hadwiger, Markus; Schmalstieg, Dieter

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

How to use 3D shadows for simple microscopy and vibrometry

Science.gov (United States)

Parikesit, Gea O. F.; Kusumaningtyas, Indraswari

2017-07-01

In 2014, we reported that shadows can be displayed in 3D using a stereoscopic setup. We now report that the 3D shadows can also be used to perform simple measurements, which are suitable for physics education in schools and colleges. Two different types of measurements are demonstrated, i.e. microscopy and vibrometry. Both types of measurements take advantage of the geometrical optics of the 3D shadows, where the 3D position of an object can be estimated using the coordinates of the colored light sources and the coordinates of the colored shadow images. We also include several student activities that can raise the students’ curiosity and capability.

Method of evaluation of radiant heat transfers for geometries having cast shadows; Methode d`evaluation des echanges radiatifs pour des geometries comportant des ombres portees

Energy Technology Data Exchange (ETDEWEB)

Lair, P; Millan, P [ONERA-CERT/DERMES, 31 - Toulouse (France); Dumoulin, J [INSA-UPS, LETHEM, 31 - Toulouse (France)

1997-12-31

Experimental studies on aero-thermal characterization of various flows are carried out by the CERT/DERMES centre of the French national office of aerospace studies and research (ONERA). The measurement is based on the infrared thermography method which requires a correction of surface fluxes. This correction is necessarily based on a radiative statement of the cell where the flow takes place. A numerical method of form factors calculation in complex geometrical configuration has been developed. This method is applicable to surfaces (flat or not) and takes into account the shadow phenomena as they can exist inside an experimental test path. Two methods of radiative statements have been developed and compared. The influence of form factors calculation on the radiative statement is also analyzed and the problem of the sensitivity of the methods with respect to possible measurement errors is evoked. (J.S.) 8 refs.

Method of evaluation of radiant heat transfers for geometries having cast shadows; Methode d`evaluation des echanges radiatifs pour des geometries comportant des ombres portees

Energy Technology Data Exchange (ETDEWEB)

Lair, P.; Millan, P. [ONERA-CERT/DERMES, 31 - Toulouse (France); Dumoulin, J. [INSA-UPS, LETHEM, 31 - Toulouse (France)

1996-12-31

Experimental studies on aero-thermal characterization of various flows are carried out by the CERT/DERMES centre of the French national office of aerospace studies and research (ONERA). The measurement is based on the infrared thermography method which requires a correction of surface fluxes. This correction is necessarily based on a radiative statement of the cell where the flow takes place. A numerical method of form factors calculation in complex geometrical configuration has been developed. This method is applicable to surfaces (flat or not) and takes into account the shadow phenomena as they can exist inside an experimental test path. Two methods of radiative statements have been developed and compared. The influence of form factors calculation on the radiative statement is also analyzed and the problem of the sensitivity of the methods with respect to possible measurement errors is evoked. (J.S.) 8 refs.

X-ray shadow projection microscopy of microwires

International Nuclear Information System (INIS)

Kasatkin, Yu.I.; Kasyuga, L.Z.; Kasyuga, P.I.; Kozyrev, A.S.; Khanonkin, A.A.

1981-01-01

The X-ray shadow projection microscopy as a method for testing geometrical parameters of microwires is considered. Two X-ray-optical circuits for measuring geometrical parameters of wires are described. It is shown that the coefficient of increase of the circuits does not depend on geometrical parameters of the wire under testing, and it is determined solely by the construction peculiarities of the circuits. The testability of geometric parameters of a wire, using DRON-2.0 X-ray diffractometer or its like, is discussed [ru

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.

A Physics-Based Deep Learning Approach to Shadow Invariant Representations of Hyperspectral Images.

Science.gov (United States)

Windrim, Lloyd; Ramakrishnan, Rishi; Melkumyan, Arman; Murphy, Richard J

2018-02-01

This paper proposes the Relit Spectral Angle-Stacked Autoencoder, a novel unsupervised feature learning approach for mapping pixel reflectances to illumination invariant encodings. This work extends the Spectral Angle-Stacked Autoencoder so that it can learn a shadow-invariant mapping. The method is inspired by a deep learning technique, Denoising Autoencoders, with the incorporation of a physics-based model for illumination such that the algorithm learns a shadow invariant mapping without the need for any labelled training data, additional sensors, a priori knowledge of the scene or the assumption of Planckian illumination. The method is evaluated using datasets captured from several different cameras, with experiments to demonstrate the illumination invariance of the features and how they can be used practically to improve the performance of high-level perception algorithms that operate on images acquired outdoors.

Stress shadows - a controversial topic

Science.gov (United States)

Lasocki, Stanislaw; Karakostas, Vassilis G.; Papadimitriou, Eletheria E.; Orlecka-Sikora, Beata

2010-05-01

The spatial correlation between the positive Coulomb stress changes and the subsequent seismic activity has been firmly confirmed in many recent studies. If, however, the static stress transfer is a consistent expression of interaction between earthquakes one should also observe a decrease of the activity in the zones of negative stress changes. Instead, the existence of stress shadows is poorly evidenced and may be questioned. We tested the influence of the static stress changes associated with the coseismic slip of the 1995 Mw6.5 Kozani-Grevena (Greece) earthquake on locations of its aftershocks. The study was based on a detailed slip model for the main shock and accurate locations and reliable fault plane solutions of an adequate number of the aftershocks. We developed a statistical testing method, which tested whether the proportions of aftershocks located inside areas determined by a selected criterion on the static stress change could be attained if there were no effect of the stress change due to the main shock on aftershock locations. The areas of stress change were determined at the focus of every aftershock. The distribution of test statistic was constructed with the use of a two-dimensional nonparametric, kernel density estimator of the reference epicenter distribution. The tests highly confidently indicated a rise in probability to locate aftershocks inside areas of positive static stress change, which supported the hypothesis on the triggering effect in these areas. Furthermore, it was evidenced that a larger stress increase caused a stronger triggering effect. The analysis, however, did not evidence the existence of stress shadows inside areas of negative stress change. Contrary to expectations, the tests indicated a significant increase of the probability of event location in the areas of a stress decrease of more than or equal to 5.0 and 10.0 bar. It turned out that for areas of larger absolute stress change this probability increased regardless of

Power fluctuation and power loss of wind turbines due to wind shear and tower shadow

Institute of Scientific and Technical Information of China (English)

Binrong WEN; Sha WEI; Kexiang WEI; Wenxian YANG; Zhike PENG; Fulei CHU

2017-01-01

The magnitude and stability of power output are two key indices of wind turbines.This study investigates the effects of wind shear and tower shadow on power output in terms of power fluctuation and power loss to estimate the capacity and quality of the power generated by a wind turbine.First,wind speed models,particularly the wind shear model and the tower shadow model,are described in detail.The widely accepted tower shadow model is modified in view of the cone-shaped towers of modem large-scale wind turbines.Power fluctuation and power loss due to wind shear and tower shadow are analyzed by performing theoretical calculations and case analysis within the framework of a modified version of blade element momentum theory.Results indicate that power fluctuation is mainly caused by tower shadow,whereas power loss is primarily induced by wind shear.Under steady wind conditions,power loss can be divided into wind farm loss and rotor loss.Wind farm loss is constant at 3α(3α-1)R2/(8H2).By contrast,rotor loss is strongly influenced by the wind turbine control strategies and wind speed.That is,when the wind speed is measured in a region where a variable-speed controller works,the rotor loss stabilizes around zero,but when the wind speed is measured in a region where the blade pitch controller works,the rotor loss increases as the wind speed intensifies.The results of this study can serve as a reference for accurate power estimation and strategy development to mitigate the fluctuations in aerodynamic loads and power output due to wind shear and tower shadow.

On Risk Charges and Shadow Account Options in Pension Funds

DEFF Research Database (Denmark)

Jørgensen, Peter Løchte; Gatzert, Nadine

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......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...

The Hare and the Tortoise. How Older Generations Are Replaced By Young One on the Labour Market: Signals and Insights from the Relationship between Shadow Economy and Active Ageing

Directory of Open Access Journals (Sweden)

Adriana AnaMaria DAVIDESCU

2015-06-01

Full Text Available The paper aims to analyze the relationship between the size of Romanian shadow economy expressed as % of official GDP and active ageing in order to see if the shadow economy represents a social buffer for active ageing phenomena using Granger causality analysis. The size of Romanian shadow economy is estimated previously using a revised version of the currency demand approach based on autoregressive distributed lag (ARDL approach to cointegration analysis. Using Granger causality tests, we examine the relationship between employment rate for older people and the size of Romanian shadow economy covering the period between 2000 and 2010. The empirical results revealed the existence of a long-run unidirectional causality that runs shadow economy to employment rate for elderly and do not support the existence of any short-run relationship between employment rate for older people and shadow economy.

Rural-to-urban migration and the shadow wage in LDCs.

Science.gov (United States)

Renard, R

1984-04-01

"This paper discusses the amount of rural-to-urban migration which will be forthcoming when a new urban job is created for which an institutionally fixed wage above the market-clearing level is offered. A simple formula is proposed to estimate migration response. It can be used to calculate the shadow wage in cost-benefit analysis (CBA) in less developed countries (LDCs)." excerpt

K Coverage Probability of 5G Wireless Cognitive Radio Network under Shadow Fading Effects

Directory of Open Access Journals (Sweden)

Ankur S. Kang

2016-09-01

Full Text Available Land mobile communication is burdened with typical propagation constraints due to the channel characteristics in radio systems.Also,the propagation characteristics vary form place to place and also as the mobile unit moves,from time to time.Hence,the tramsmission path between transmitter and receiver varies from simple direct LOS to the one which is severely obstructed by buildings,foliage and terrain.Multipath propagation and shadow fading effects affect the signal strength of an arbitrary Transmitter-Receiver due to the rapid fluctuations in the phase and amplitude of signal which also determines the average power over an area of tens or hundreds of meters.Shadowing introduces additional fluctuations,so the received local mean power varies around the area –mean.The present section deals with the performance analysis of fifth generation wireless cognitive radio network on the basis of signal and interference level based k coverage probability under the shadow fading effects.

Calibration of UAS imagery inside and outside of shadows for improved vegetation index computation

Science.gov (United States)

Bondi, Elizabeth; Salvaggio, Carl; Montanaro, Matthew; Gerace, Aaron D.

2016-05-01

Vegetation health and vigor can be assessed with data from multi- and hyperspectral airborne and satellite- borne sensors using index products such as the normalized difference vegetation index (NDVI). Recent advances in unmanned aerial systems (UAS) technology have created the opportunity to access these same image data sets in a more cost effective manner with higher temporal and spatial resolution. Another advantage of these systems includes the ability to gather data in almost any weather condition, including complete cloud cover, when data has not been available before from traditional platforms. The ability to collect in these varied conditions, meteorological and temporal, will present researchers and producers with many new challenges. Particularly, cloud shadows and self-shadowing by vegetation must be taken into consideration in imagery collected from UAS platforms to avoid variation in NDVI due to changes in illumination within a single scene, and between collection flights. A workflow is presented to compensate for variations in vegetation indices due to shadows and variation in illumination levels in high resolution imagery collected from UAS platforms. Other calibration methods that producers may currently be utilizing produce NDVI products that still contain shadow boundaries and variations due to illumination, whereas the final NDVI mosaic from this workflow does not.

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.

Determination of the scattered radiation at the Neutron Calibration Laboratory of IPEN using the shadow cone method

Energy Technology Data Exchange (ETDEWEB)

Alvarenga, Tallyson S.; Caldas, Linda V.E. [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), São Paulo, SP (Brazil); Freitas, Bruno M. [Coordenacao de Pos-Graduacao e Pesquisa de Engenharia (PEN/COPPE/UFRJ), Rio de Janeiro, RJ (Brazil). Programa de Engenharia Nuclear; Fonseca, Evaldo S.; Pereira, Walsan W., E-mail: talvarenga@ipen.br, E-mail: lcaldas@ipen.br, E-mail: bfreitas@con.ufrj.br, E-mail: walsan@ird.gov.br, E-mail: evaldo@ird.gov.br [Instituto de Radioprotecao e Dosimetria (IRD/CNEN-RJ), Rio de Janeiro, RJ (Brazil)

2017-07-01

Because of the increase in the demand for the calibration of neutron detectors, there is a need for new calibration services. In this context, the Calibration Laboratory of Instituto de Pesquisas Energéticas e Nucleares (IPEN), São Paulo, which already offers calibration services of radiation detectors with standard X, gamma, beta and alpha beams, has recently projected a new test laboratory for neutron detectors. This work evaluated the contribution of dispersed neutron radiation in this laboratory, using the cone shadow method and a Bonner sphere spectrometer to take the measurements at a distance of 100 cm from the neutron source. The dosimetric quantities H⁎(10) and H⁎(10) were obtained at the laboratory, allowing the calibration of detectors. (author)

Determination of Young's modulus of epoxy coated polyethylene micro-cantilever using phase-shift shadow moiré method

Science.gov (United States)

Lim, J. H.; Ratnam, M. M.; Azid, I. A.; Mutharasu, D.

2011-11-01

Young's moduli of various epoxy coated polyethylene terephthalate (PET) micro-cantilevers were determined from the deflection results obtained using the phase-shift shadow moiré (PSSM) method. The filler materials for epoxy coatings were aluminum and graphite powders that were mixed with epoxy at various percentages. Young's moduli were calculated from theory based on the deflection results. The PET micro-cantilever coated with aluminum-epoxy coating showed increasing value of Young's modulus when the ratios of the aluminum-epoxy were increased. The graphite-epoxy coating on the PET micro-cantilever also showed the same trend. The experimental results also show that Young's modulus of the graphite-epoxy coating is higher than aluminum-epoxy coating in comparison at the same mixing ratio.

Determination of the scattered radiation at the Neutron Calibration Laboratory of IPEN using the shadow cone method

International Nuclear Information System (INIS)

Alvarenga, Tallyson S.; Caldas, Linda V.E.; Freitas, Bruno M.

2017-01-01

Because of the increase in the demand for the calibration of neutron detectors, there is a need for new calibration services. In this context, the Calibration Laboratory of Instituto de Pesquisas Energéticas e Nucleares (IPEN), São Paulo, which already offers calibration services of radiation detectors with standard X, gamma, beta and alpha beams, has recently projected a new test laboratory for neutron detectors. This work evaluated the contribution of dispersed neutron radiation in this laboratory, using the cone shadow method and a Bonner sphere spectrometer to take the measurements at a distance of 100 cm from the neutron source. The dosimetric quantities H⁎(10) and H⁎(10) were obtained at the laboratory, allowing the calibration of detectors. (author)

Training Classifiers with Shadow Features for Sensor-Based Human Activity Recognition.

Science.gov (United States)

Fong, Simon; Song, Wei; Cho, Kyungeun; Wong, Raymond; Wong, Kelvin K L

2017-02-27

In this paper, a novel training/testing process for building/using a classification model based on human activity recognition (HAR) is proposed. Traditionally, HAR has been accomplished by a classifier that learns the activities of a person by training with skeletal data obtained from a motion sensor, such as Microsoft Kinect. These skeletal data are the spatial coordinates (x, y, z) of different parts of the human body. The numeric information forms time series, temporal records of movement sequences that can be used for training a classifier. In addition to the spatial features that describe current positions in the skeletal data, new features called 'shadow features' are used to improve the supervised learning efficacy of the classifier. Shadow features are inferred from the dynamics of body movements, and thereby modelling the underlying momentum of the performed activities. They provide extra dimensions of information for characterising activities in the classification process, and thereby significantly improve the classification accuracy. Two cases of HAR are tested using a classification model trained with shadow features: one is by using wearable sensor and the other is by a Kinect-based remote sensor. Our experiments can demonstrate the advantages of the new method, which will have an impact on human activity detection research.

Training Classifiers with Shadow Features for Sensor-Based Human Activity Recognition

Directory of Open Access Journals (Sweden)

Simon Fong

2017-02-01

Full Text Available In this paper, a novel training/testing process for building/using a classification model based on human activity recognition (HAR is proposed. Traditionally, HAR has been accomplished by a classifier that learns the activities of a person by training with skeletal data obtained from a motion sensor, such as Microsoft Kinect. These skeletal data are the spatial coordinates (x, y, z of different parts of the human body. The numeric information forms time series, temporal records of movement sequences that can be used for training a classifier. In addition to the spatial features that describe current positions in the skeletal data, new features called ‘shadow features’ are used to improve the supervised learning efficacy of the classifier. Shadow features are inferred from the dynamics of body movements, and thereby modelling the underlying momentum of the performed activities. They provide extra dimensions of information for characterising activities in the classification process, and thereby significantly improve the classification accuracy. Two cases of HAR are tested using a classification model trained with shadow features: one is by using wearable sensor and the other is by a Kinect-based remote sensor. Our experiments can demonstrate the advantages of the new method, which will have an impact on human activity detection research.

Evaluation and comparison of signal to noise ratio according to histogram equalization of heart shadow on chest image

International Nuclear Information System (INIS)

Kim, Ki Won; Lee, Eul Kyu; Jeong, Hoi Woun; Kang, Byung Sam; Kim, Hyun Soo; Min, Jung Whan; Son, Jin Hyun

2017-01-01

The purpose of this study was to measure signal to noise ratio (SNR) according to change of equalization from region of interest (ROI) of heart shadow in chest image. We examined images of chest image of 87 patients in a University-affiliated hospital, Seoul, Korea. Chest images of each patient were calculated by using Image. We have analysis socio-demographical variables, SNR according to images, 95% confidence according to SNR of difference in a mean of SNR. Differences of SNR among change of equalization were tested by SPSS Statistics21 ANOVA test for there was statistical significance 95%(p < 0.05). In SNR results, with the quality of distributions in the order of original chest image, original chest image heart shadow and equalization chest image, equalization chest image heart shadow(p < 0.001). In conclusion, this study would be that quantitative evaluation of heart shadow on chest image can be used as an adjunct to the histogram equalization chest image

Evaluation and comparison of signal to noise ratio according to histogram equalization of heart shadow on chest image

Energy Technology Data Exchange (ETDEWEB)

Kim, Ki Won [Dept. of Radiology, Kyung Hee University Hospital at Gang-dong, Seoul (Korea, Republic of); Lee, Eul Kyu [Inje Paik University Hospital at Jeo-dong, Seoul (Korea, Republic of); Jeong, Hoi Woun [The Baekseok Culture University, Cheonan (Korea, Republic of); Kang, Byung Sam; Kim, Hyun Soo; Min, Jung Whan; Son, Jin Hyun [The Shingu University, Seongnam (Korea, Republic of)

2017-06-15

The purpose of this study was to measure signal to noise ratio (SNR) according to change of equalization from region of interest (ROI) of heart shadow in chest image. We examined images of chest image of 87 patients in a University-affiliated hospital, Seoul, Korea. Chest images of each patient were calculated by using Image. We have analysis socio-demographical variables, SNR according to images, 95% confidence according to SNR of difference in a mean of SNR. Differences of SNR among change of equalization were tested by SPSS Statistics21 ANOVA test for there was statistical significance 95%(p < 0.05). In SNR results, with the quality of distributions in the order of original chest image, original chest image heart shadow and equalization chest image, equalization chest image heart shadow(p < 0.001). In conclusion, this study would be that quantitative evaluation of heart shadow on chest image can be used as an adjunct to the histogram equalization chest image.

Nuclear shadowing and the optics of hadronic fluctuations

Energy Technology Data Exchange (ETDEWEB)

Mankiewicz, L. E-mail: lech_mankiewicz@camk.edu.pl; Piller, G.; Vaenttinen, M.; Weise, W

2001-06-04

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.

Shadow Cost of Public Funds and Privatization Policies

OpenAIRE

Sato, Susumu; Matsumura, Toshihiro

2017-01-01

We investigate the optimal privatization policy in mixed oligopolies with shadow cost of public funds (excess burden of taxation). The government is concerned with both the total social surplus and the revenue obtained by the privatization of a public firm. We find that the relationship between the shadow cost of public funds and the optimal privatization policy is non-monotone. When the cost is moderate, then higher the cost is, the lower is the optimal degree of privatization. ...

Gaining Control of Iraq's Shadow Economy

National Research Council Canada - National Science Library

Ramirez, David S

2007-01-01

.... These conditions fuel a sprawling, decades-old shadow economy manipulated by elements of organized crime, militias, and insurgents to fund attacks on Coalition forces, infrastructure and innocent Iraqi civilians...

THE OBJECTIFICATION OF DEFINITION OF THE PURCHASING POWER OF CONSUMERS IN SHADOW ECONOMY

Directory of Open Access Journals (Sweden)

N. Tyukhtenko

2016-04-01

Full Text Available The paper analyzed the level of truthfulness of information as to actual volume revenues of workers of the shadow economy. Revealed results of actual solvency of the local population by goods production, work execution, services rendering. Discovered action of currency fluctuation. Analyzed sales of new cars in Ukraine for 2010-2014. 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 of the sale market of new cars. Defined the optimal selling price of new vehicles in Kherson. Calculated potential market volume of new vehicles and optimal logistic route of their realization in the Kherson region.

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.

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.

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. Copyright © 2015 Elsevier B.V. All rights reserved.

A locally adaptive algorithm for shadow correction in color images

Science.gov (United States)

Karnaukhov, Victor; Kober, Vitaly

2017-09-01

The paper deals with correction of color images distorted by spatially nonuniform illumination. A serious distortion occurs in real conditions when a part of the scene containing 3D objects close to a directed light source is illuminated much brighter than the rest of the scene. A locally-adaptive algorithm for correction of shadow regions in color images is proposed. The algorithm consists of segmentation of shadow areas with rank-order statistics followed by correction of nonuniform illumination with human visual perception approach. The performance of the proposed algorithm is compared to that of common algorithms for correction of color images containing shadow regions.

The Effect of Topographic Shadowing by Ice on Irradiance in the Greenland Ice Sheet Ablation Zone

Science.gov (United States)

Leidman, S. Z.; Rennermalm, A. K.; Ryan, J.; Cooper, M. G.; Smith, L. C.

2017-12-01

Accurately predicting runoff contributions to global sea level rise requires more refined surface mass balance (SMB) models of the Greenland Ice Sheet (GrIS). Topographic shadowing has shown to be important in the SMB of snow-covered regions, yet SMB models for the GrIS generally ignore how surface topography affects spatial variability of incoming solar radiation on a surface. In the ablation zone of Southwest Greenland, deeply incised supraglacial drainage features, fracturing, and large-scale bed deformation result in extensive areas of rough surface topography. This topography blocks direct radiation such that shadowed areas receive less energy for melting while other topographic features such as peaks recieve more energy. In this study, we quantify how shadowing from local topography features changes incoming solar radiation. We apply the ArcGIS Pro Solar Radiation Toolset to calculate the direct and diffuse irradiance in sunlit and shadowed areas by determining the sun's movement for every half hour increment of 2016. Multiple digital elevation models (DEMs) with spatial resolutions ranging from 0.06 to 5m were derived from fixed wing and quadcopter UAV imagery collected in summer 2016 and the ArcticDEM dataset. Our findings show that shadowing significantly decreases irradiance compared to smoothed surfaces where local topography is removed. This decrease is exponentially proportional to the DEM pixel sized with 5m DEMs only able to capture a small percentage of the effect. Applying these calculations to the ArcticDEM to cover a larger study area indicates that decreases in irradiance are nonlinearly proportional to elevation with highly crevassed areas showing a larger effect from shadowing. Even so, shading at higher elevations reduces irradiance enough to result in several centimeters snow water equivalence (SWE) per year of over-prediction of runoff in SMB models. Furthermore, analysis of solar radiation products shows that shadowing predicts albedo

SHADOW3: a new version of the synchrotron X-ray optics modelling package

International Nuclear Information System (INIS)

Sanchez del Rio, Manuel; Canestrari, Niccolo; Jiang, Fan; Cerrina, Franco

2011-01-01

SHADOW3, a new version of the X-ray tracing code SHADOW, is introduced. A new version of the popular X-ray tracing code SHADOW is presented. An important step has been made in restructuring the code following new computer engineering standards, ending with a modular Fortran 2003 structure and an application programming interface (API). The new code has been designed to be compatible with the original file-oriented SHADOW philosophy, but simplifying the compilation, installation and use. In addition, users can now become programmers using the newly designed SHADOW3 API for creating scripts, macros and programs; being able to deal with optical system optimization, image simulation, and also low transmission calculations requiring a large number of rays (>10 6 ). Plans for future development and questions on how to accomplish them are also discussed

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.

Error analysis of the phase-shifting technique when applied to shadow moire

International Nuclear Information System (INIS)

Han, Changwoon; Han Bongtae

2006-01-01

An exact solution for the intensity distribution of shadow moire fringes produced by a broad spectrum light is presented. A mathematical study quantifies errors in fractional fringe orders determined by the phase-shifting technique, and its validity is corroborated experimentally. The errors vary cyclically as the distance between the reference grating and the specimen increases. The amplitude of the maximum error is approximately 0.017 fringe, which defines the theoretical limit of resolution enhancement offered by the phase-shifting technique

MPPT-Based Control Algorithm for PV System Using iteration-PSO under Irregular shadow Conditions

Directory of Open Access Journals (Sweden)

M. Abdulkadir

2017-02-01

Full Text Available The conventional maximum power point tracking (MPPT techniques can hardly track the global maximum power point (GMPP because the power-voltage characteristics of photovoltaic (PV exhibit multiple local peaks in irregular shadow, and therefore easily fall into the local maximum power point. These conditions make it very challenging, and to tackle this deficiency, an efficient Iteration Particle Swarm Optimization (IPSO has been developed to improve the quality of solution and convergence speed of the traditional PSO, so that it can effectively track the GMPP under irregular shadow conditions. This proposed technique has such advantages as simple structure, fast response and strong robustness, and convenient implementation. It is applied to MPPT control of PV system in irregular shadow to solve the problem of multi-peak optimization in partial shadow. In order to verify the rationality of the proposed algorithm, however, recently the dynamic MPPT performance under varying irradiance conditions has been given utmost attention to the PV society. As the European standard EN 50530 which defines the recommended varying irradiance profiles, was released lately, the corresponding researchers have been required to improve the dynamic MPPT performance. This paper tried to evaluate the dynamic MPPT performance using EN 50530 standard. The simulation results show that iterative-PSO method can fast track the global MPP, increase tracking speed and higher dynamic MPPT efficiency under EN 50530 than the conventional PSO.

SHADOW3: a new version of the synchrotron X-ray optics modelling package

Energy Technology Data Exchange (ETDEWEB)

Sanchez del Rio, Manuel, E-mail: srio@esrf.eu [European Synchrotron Radiation Facility, 6 Jules Horowitz, 38000 Grenoble (France); Canestrari, Niccolo [CNRS, Grenoble (France); European Synchrotron Radiation Facility, 6 Jules Horowitz, 38000 Grenoble (France); Jiang, Fan; Cerrina, Franco [Boston University, 8 St Mary’s Street, Boston, MA 02215 (United States)

2011-09-01

SHADOW3, a new version of the X-ray tracing code SHADOW, is introduced. A new version of the popular X-ray tracing code SHADOW is presented. An important step has been made in restructuring the code following new computer engineering standards, ending with a modular Fortran 2003 structure and an application programming interface (API). The new code has been designed to be compatible with the original file-oriented SHADOW philosophy, but simplifying the compilation, installation and use. In addition, users can now become programmers using the newly designed SHADOW3 API for creating scripts, macros and programs; being able to deal with optical system optimization, image simulation, and also low transmission calculations requiring a large number of rays (>10{sup 6}). Plans for future development and questions on how to accomplish them are also discussed.

Three-Dimensional Reconstruction Optical System Using Shadows Triangulation

Science.gov (United States)

Barba, J. Leiner; Vargas, Q. Lorena; Torres, M. Cesar; Mattos, V. Lorenzo

2008-04-01

In this work is developed a three-dimensional reconstruction system using the Shades3D tool of the Matlab® Programming Language and materials of low cost, such as webcam camera, a stick, a weak structured lighting system composed by a desk lamp, and observation plane in which the object is located. The reconstruction is obtained through a triangulation process that is executed after acquiring a sequence of images of the scene with a shadow projected on the object; additionally an image filtering process is done for obtaining only the part of the scene that will be reconstructed. Previously, it is necessary to develop a calibration process for determining the internal camera geometric and optical characteristics (intrinsic parameters), and the 3D position and orientation of the camera frame relative to a certain world coordinate system (extrinsic parameters). The lamp and the stick are used to produce a shadow which scans the object; in this technique, it is not necessary to know the position of the light source, instead the triangulation is obtained using shadow plane produced by intersection between the stick and the illumination pattern. The webcam camera captures all images with the shadow scanning the object, and Shades3D tool processes all information taking into account captured images and calibration parameters. Likewise, this technique is evaluated in the reconstruction of parts of the human body and its application in the detection of external abnormalities and elaboration of prosthesis or implant.

A circuit-based photovoltaic module simulator with shadow and fault settings

Science.gov (United States)

Chao, Kuei-Hsiang; Chao, Yuan-Wei; Chen, Jyun-Ping

2016-03-01

The main purpose of this study was to develop a photovoltaic (PV) module simulator. The proposed simulator, using electrical parameters from solar cells, could simulate output characteristics not only during normal operational conditions, but also during conditions of partial shadow and fault conditions. Such a simulator should possess the advantages of low cost, small size and being easily realizable. Experiments have shown that results from a proposed PV simulator of this kind are very close to that from simulation software during partial shadow conditions, and with negligible differences during fault occurrence. Meanwhile, the PV module simulator, as developed, could be used on various types of series-parallel connections to form PV arrays, to conduct experiments on partial shadow and fault events occurring in some of the modules. Such experiments are designed to explore the impact of shadow and fault conditions on the output characteristics of the system as a whole.

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…

The inclusion of shadowing effect in the reaction-rates calculation

International Nuclear Information System (INIS)

Monteiro, M.A.M.

1990-03-01

A method for the Resonance Integral calculation in the fuel and moderator regions is presented including the Shadowing effect. This effect appears due to the presence of several fuel rods in a infinite moderator region. The method is based on the approximations to the J (ζ, β) function and theirs partial derivatives in relation to β. The dependence of the Resonance Integral in the J (ζ, β) comes from the rational approximation to the neutron escape probability. The final results are obtained in a very simple and fast way, and show the good accuracy of the method. (author)

Mapping the ultrasonic defect shadow in a pitch-catch mode

International Nuclear Information System (INIS)

Licht, H.; Hallet, J.B.

1981-06-01

In ultrasonic testing of metallic structures, the sound reflected from a discontinuity is usually used to determine its location and size. Here is described a technique for locating and sizing a discontinuity by mapping the shadow(s) it casts. A brief description of the technique is given. Results obtained from artificial notches and fatigue cracks are outlined and discussed

Shadow corrosion evaluation in the Studsvik R2 reactor

International Nuclear Information System (INIS)

Sanders, Ch.; Lysell, G.

2000-01-01

Post-irradiation examination has shown that increased corrosion occurs when zirconium alloys are in contact with or in proximity to other metallic objects. The observations indicate an influence of irradiation from the adjacent component as the enhanced corrosion occurs as a 'shadow' of the metallic object on the zirconium surface. This phenomenon could ultimately limit the lifetime of certain zirconium alloy components in the reactor. The Studsvik R2 materials test reactor has an In-Core Autoclave (INCA) test facility especially designed for water chemistry and materials research. The INCA facility has been evaluated and found suitable for shadow corrosion studies. The R2 reactor core containing the INCA facility was modeled with the Monte Carlo N-Particle (MCNP) code in order to evaluate the electron deposition in various materials and to develop a hypothesis of the shadow corrosion mechanism. (authors)

Gaining Control of Iraq's Shadow Economy

National Research Council Canada - National Science Library

Ramirez, David S

2007-01-01

.... The shadow economy is also used extensively by the poor and women for subsistence living. The combined effect for Iraqi citizens is they have to survive in a country without adequate institutions and poor governance...

Shadows on the wall

International Nuclear Information System (INIS)

Swift, Diana.

1984-01-01

Canadian antinuclear groups, because of their shifting stances and fluid overlapping membership, are compared with shadows on a wall. They can be roughly classified as environmental, pacifist, concerned with energy, religious, or dedicated to nuclear responsibility. The author considers that such groups, despite their arguably unrealistic attitudes, have raised public awareness of the ethical, practical and financial aspects of power development in Canada and the world

Estimating the shadow prices of SO2 and NOx for U.S. coal power plants: A convex nonparametric least squares approach

International Nuclear Information System (INIS)

Mekaroonreung, Maethee; Johnson, Andrew L.

2012-01-01

Weak disposability between outputs and pollutants, defined as a simultaneous proportional reduction of both outputs and pollutants, assumes that pollutants are byproducts of the output generation process and that a firm can “freely dispose” of both by scaling down production levels, leaving some inputs idle. Based on the production axioms of monotonicity, convexity and weak disposability, we formulate a convex nonparametric least squares (CNLS) quadratic optimization problem to estimate a frontier production function assuming either a deterministic disturbance term consisting only of inefficiency, or a composite disturbance term composed of both inefficiency and noise. The suggested methodology extends the stochastic semi-nonparametric envelopment of data (StoNED) described in Kuosmanen and Kortelainen (2011). Applying the method to estimate the shadow prices of SO 2 and NO x generated by U.S. coal power plants, we conclude that the weak disposability StoNED method provides more consistent estimates of market prices. - Highlights: ► Develops methodology to estimate shadow prices for SO 2 and NO x in the U.S. coal power plants. ► Extends CNLS and StoNED methods to include the weak disposability assumption. ► Estimates the range of SO 2 and NO x shadow prices as 201–343 $/ton and 409–1352 $/ton. ► StoNED method provides more accurate estimates of shadow prices than deterministic frontier.

Correcting the relationship between PRI and shadow fraction for the blue sky effect

Science.gov (United States)

Mõttus, Matti

2016-04-01

The Photochemical Reflectance Index (PRI) is defined as the normalized difference ratio of leaf reflectance at two specific wavelengths in the green spectral region. Its value depends on the status of leaf carotenoid content, and especially that of the xanthophyll cycle pigments. Due to the dependence on the xanthophyll cycle, when the photosynthetic apparatus of green leaves is close to the saturation limit, their PRI becomes dependent on light conditions. Therefore, by measuring the PRI of leaves in the same canopy under different local irradiance conditions on a sunny day, it should be possible to determine the saturation level of the leaves. In turn, this gives information on the light use efficiency (LUE) of the vegetation canopy. The average light conditions of visible foliage elements are often quantified with the shadow fraction -- the fraction of visible foliage not lit by direct sunlight. The dependence of PRI on the shadow fraction has been used to remotely measure canopy LUE on clear days. Variations in shadow fraction have been achieved with multiangular measurement. However, besides photosynthetic downregulation, the dependence of canopy PRI on shadow fraction is affected by the blue sky radiation caused by scattering in the atmosphere. To quantify this effect on remotely sensed PRI, we present the underlying definitions relating leaf and canopy PRI and perform the required calculations for typical midsummer conditions in Central Finland. We demonstrate that the effect of blue sky radiation on the variation of PRI with canopy shadow fraction is similar in shape and magnitude to that of LUE variations reported in literature. Next, we propose a new method to assess these PRI variations in structured vegetation. We investiagate this blue sky effect on the PRI -- shadow fraction relationship with high spatial (60 cm) and spectral (9.8 nm) resolution airborne imaging spectroscopy data from Hyytiälä, Finland. We evaluate the spectral irradiance in

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