检索结果-内蒙古大学图书馆

A massively parallel hardware architecture for ray-tracing

International Journal of High Performance systems Architecture 2009年第1期2卷 26-34页

作者： Nery, A.S. Nedjah, N. França, F.M.G. Computer Architecture and Microelectronics Laboratory Systems Engineering and Computer Science Program COPPE P.O. Box 68511 21941-972 Rio de Janeiro Brazil Department of Electronics Engineering and Telecommunications Faculty of Engineering Universidade do Estado do Rio de Janeiro Rua Sao Francisco Xavier 524 Sala 5145-F Maracana 20.550-900 Rio de Janeiro RJ Brazil Universidade Federal do Rio de Janeiro Rio de Janeiro Brazil Department of Electronics Engineering and Telecommunications Faculty of Engineering State University of Rio de Janeiro Brazil Brazil

Real time performance of non-interactive rendering of three-dimensional scenes is usually unachievable. Ray tracing is one of the methods used for rendering such scenes. The performance achieved by a sequential software-based implementation of ray tracing is far from satisfactory. In contrast, many parallel implementations of ray tracing have been enabling real time performance, as the underlying algorithm can be massively parallelised. Thus, it is expected that a custom parallel design in hardware is likely to achieve the acceptable performance standards. In this paper, we propose a hardware architecture, which we call GridRT, capable of dealing with the main desirable features of ray tracing, such as shadows and reflections effects, imposing low requirements in terms of silicon area while achieving acceptable performance in terms of rendering time. This architecture achieves is efficient yet compact as it explores the massive parallelism offered by the intrinsic structure of the algorithm. The design exploits the usage the spatial data structure of regular grids. Copyright © 2009 Inderscience Enterprises Ltd.

关键词： Ray tracing

来源：评论

学校读者我要写书评

暂无评论

On using grid of collocated APs to improve performance of wireless VoD systems

On using grid of collocated APs to improve performance of wi...

引用

5th International Latin American Networking Conference, LANC 2009

作者： De Pinho, Leonardo Bidese De Amorim, Claudio Luis Computer Engineering - Campus Bage UNIPAMPA - Federal University of Pampa P.O. Box 07 Bage RS 96400-970 Brazil COPPE - Systems Engineering Program UFRJ - Federal University of Rio de Janeiro P.O. Box 68.511 Rio de Janeiro RJ 21941-972 Brazil

ISBN: (纸本)9781605587752

In previous work we showed that Collocated Wireless Access Points coupled with appropriate management of their non-overlapping channels could be used for building Scalable Wireless Video-On-Demand (SWVoD) systems within a limited covered area. In this paper, we introduce the Grid of collocated Access Points or simply GAPS, a novel approach that uses clusters of Collocated Access Points as the basic blocks to efficiently build SWVoD systems for a wider covered area. In GAPS, each basic block is responsible for a distinct part of the covered area and the amount of APs per block can be set either statically or dynamically depending on the client concentration pattern (CCP). We present in details the framework of GAPS and report simulated performance results that indicated that GAPS could significantly decrease the blocking rate of video requests in comparison with previous design based on fixed distribution of basic blocks. In addition, GAPS had the advantage of sustaining the lower blockage rate over larger covered areas. Also, we showed that the higher setup cost of dynamic grids was fully compensated by handling changes on CCP much better than the static scheme so that GAPS could generate a higher monthly net income according to our cost metric. Copyright 2009 ACM.

关键词： Video on demand

来源：评论

学校读者我要写书评

暂无评论

Impact of region-based faults on the connectivity of wireless networks

Impact of region-based faults on the connectivity of wireles...

引用

Annual Allerton Conference on Communication, Control, and Computing

作者： Arunabha Sen Sujogya Banerjee Pavel Ghosh Shahrzad Shirazipourazad Computer Science and Engineering Program School of Computing Informatics and Decision Systems Engineering Arizona State University Tempe AZ USA

ISBN: (纸本)9781424458707

The last few years have seen considerable interest in the wireless networking research community in analyzing the connectivity of wireless ad-hoc networks formed by a set of nodes distributed in a two dimensional plane (deployment area) with a (i) uniform probability density function and (ii) uniform transmission range. Although several important and interesting results are known in this domain, most of the connectivity studies consider a fault-free scenario where all nodes are available for network formation and do not consider failures among nodes caused by one reason or another. In very few studies where faults are considered, they are usually considered to be random in nature, i.e., the probability of a node failing is independent of its location in the deployment area. However, such fault scenario is inadequate to capture many realistic situations where the faulty nodes are spatially correlated. This is particularly true in combat environment where an enemy bomb can destroy a subset of nodes confined to a region. In this paper we investigate the impact of region-based faults on the connectivity of wireless networks. Through analysis and simulation, we provide results relating the probability of a network being connected as transmission range and the size of fault-region are varied. If d min (G) denotes the minimum node degree of the network, we provide the analytical expression for P(d min (G) ¿ k), which represents the probability of the minimum node degree being at least k, for k = 1. Moreover, we compute P(¿(G) ¿ k), where ¿(G) represents the connectivity of the graph G formed by the distribution of nodes in the deployment area and examine the relationship between P(d min (G) ¿ k) and P(¿(G) ¿ k) when k = 1.

关键词： Wireless networks Distributed computing Weapons Analytical models computer science computer networks Informatics systems engineering and theory Ad hoc networks Probability density function

来源：评论

学校读者我要写书评

暂无评论

Comparison of threshold selection methods for microarray gene co-expression matrices

引用

BMC Research Notes 2009年第1期2卷 1-6页

作者： Borate, Bhavesh Chesler, Elissa Langston, Michael Saxton, Arnold Voy, Brynn Genome Science and Technology Program University of Tennessee Knoxville TN United States Department of Electrical Engineering and Computer Science University of Tennessee Knoxville TN United States Oak Ridge National Laboratory Systems Genetics Group Biosciences Division Oak Ridge TN United States Department of Animal Science University of Tennessee Knoxville TN United States

Background. Network and clustering analyses of microarray co-expression correlation data often require application of a threshold to discard small correlations, thus reducing computational demands and decreasing the number of uninformative correlations. This study investigated threshold selection in the context of combinatorial network analysis of transcriptome data. Findings. Six conceptually diverse methods - based on number of maximal cliques, correlation of control spots with expressed genes, top 1% of correlations, spectral graph clustering, Bonferroni correction of p-values, and statistical power - were used to estimate a correlation threshold for three time-series microarray datasets. The validity of thresholds was tested by comparison to thresholds derived from Gene Ontology information. Stability and reliability of the best methods were evaluated with block bootstrapping. Two threshold methods, number of maximal cliques and spectral graph, used information in the correlation matrix structure and performed well in terms of stability. Comparison to Gene Ontology found thresholds from number of maximal cliques extracted from a co-expression matrix were the most biologically valid. Approaches to improve both methods were suggested. Conclusion. Threshold selection approaches based on network structure of gene relationships gave thresholds with greater relevance to curated biological relationships than approaches based on statistical pair-wise relationships. © 2009 Saxton et al;licensee BioMed Central Ltd.

关键词： Spectral Cluster Maximal Clique Threshold Estimate Biological Relationship Spectral Graph

来源：评论

学校读者我要写书评

暂无评论

A neuromorphic head direction cell system

A neuromorphic head direction cell system

引用

IEEE International Symposium on Circuits and systems (ISCAS)

作者： Tarek M. Massoud Timothy K. Horiuchi Electrical and Computer Engineering Department Institute of Systems Research Neuroscience and Cognitive Science Program University of Maryland College Park MD USA

ISBN: (纸本)9781424438273

The head direction (HD) cell system in the brain of mammals is thought to be part of the neural circuitry supporting their spatial navigation capabilities. In this paper we present a neuromorphic VLSI system that mimics the operation of the HD system. Relying on spiking neurons and attractor dynamics, this system can be used to represent and retain the current estimate of head orientation in the environment and integrate angular velocity to update this estimate. The presented system is a first step towards more general odometry systems that could be used for modeling biological navigation systems.

关键词： Neuromorphics Neurons High definition video Navigation Very large scale integration Biological system modeling Brain Neuroscience Cognitive science Educational institutions

来源：评论

学校读者我要写书评

暂无评论

Dynamic screen division for load balancing the raycasting of irregular data

Dynamic screen division for load balancing the raycasting of...

引用

IEEE International Conference on Cluster Computing

作者： Bernardo B. Labronici Cristiana Bentest Lucia Maria A. Drummond Ricardo Farias Computer Science Department Federal Fluminense University Niterói RJ Brazil Department of System Engineering State University of Rio de Janeiro Rio de Janeiro RJ Brazil System Engineering and Computer Science Program-COPPE Centro de Tecnologia Rio de Janeiro RJ Brazil

Parallel rendering algorithms usually suffer from high load imbalance during execution, due to the irregular nature of the datasets. In this paper, we propose a new load balancing scheme for tile-based parallel rendering that includes strategies for load estimation, tile decomposition and tile assignment. The load estimation strategy computes the rendering cost for each pixel, and uses it as a prediction for the next frame. The tile decomposition strategy adaptively divides the screen into tiles based on the computed costs, until an evenly tile partition is achieved. The tile assignment strategy distributes the tiles among rendering processors, based on a 2-optimal scheduling. Experimental results show that our scheme achieves significant performance gains by reducing the load imbalance when compared to the traditional tile subdivision and static random distribution schemes.

关键词： Load management Tiles Rendering (computer graphics) Concurrent computing Parallel processing computer science Costs Data visualization Data engineering systems engineering and theory

来源：评论

学校读者我要写书评

暂无评论

AAAI 2008 workshop reports

AAAI 2008 workshop reports

引用

作者： Anand, Sarabjot Singh Bunescu, Razvan Carvcdho, Vitor Chomicki, Jan Conitzer, Vincent Cox, Michael T. Dignum, Virginia Dodds, Zachary Dredze, Mark Furcy, David Gabrilovich, Evgeniy Göker, Mehmet H. Guesgen, Hans Hirsh, Haym Jannach, Dietmar Junker, Ulrich Ketter, Wolfgang Kobsa, Alfred Koenig, Sven Lau, Tessa Lewis, Lundy Matson, Eric Metzler, Ted Mihalcea, Rada Mobasher, Bamshad Pineau, Joelle Poupart, Pascal Raja, Anita Ruml, Wheeler Sadeh, Norman Shani, Guy Shapiro, Daniel Smith, Trey Taylor, Matthew E. Wagstaff, Kiri Walsh, William Zhou, Rong Department of Computer Science University of Warwick United Kingdom School of Electrical Engineering and Computer Science Ohio University United States Microsoft Live Labs United States computer science and engineering University at Buffalo United States Computer science and economics Duke University United States Intelligent Computing group of BBN Technologies Utrecht University Netherlands Department of Computer science Harvey Mudd College United States University of Pennsylvania United States University of Wisconsin United States Yahoo Research PricewaterhouseCoopers Center for Advanced Research United States Department of Computer science School of Engineering and Advanced Technology Massey University New Zealand Departent of Computer science Rutgers University United States Department of Computer Science Dortmund University of Technology. Germany ILOG Rotterdam School of Management Erasmus University Netherlands Donald Bren School of Information and Computer Sciences University of California Irvine United States Depatrment of Computer science University of Southern California United States IBM Almaden Research Center United States Department of Computer Information Technology Southern New Hampshire University United States Computer and Information Technology Program College of Technology Purdue University United States Hughes Program for Religion and Science Dialogue Oklahoma City University United States Department of Computer Science and Engineering University of North Texas United States School of Computing DePaul University United States Department of Computer Science McGill University Canada School of Computer Science University of Waterloo Canada Department of Software and Information Systems University of North Carolina Charlotte United States University of New Hampshire United States Microsoft Research Institute for the Study of Learning and Expertise Applied Reactivity Inc. United States NASA Ames Research Center Carnegie Mellon University West

AAAI was pleased to present the AAAI-08 Workshop program, held Sunday and Monday, July 13-14, in Chicago, Illinois, USA. The program included the following 15 workshops: Advancements in POMDP Solvers;AI Education Workshop Colloquium;Coordination, Organizations, Institutions, and Norms in Agent systems, Enhanced Messaging;Human Implications of Human-Robot Interaction;Intelligent Techniques for Web Personalization and Recommender systems;Metareasoning: Thinking about Thinking;Multidisciplinary Workshop on Advances in Preference Handling;Search in Artificial Intelligence and Robotics;Spatial and Temporal Reasoning;Trading Agent Design and Analysis;Transfer Learning for Complex Tasks;What Went Wrong and Why: Lessons from AI Research and Applications;and Wikipedia and Artificial Intelligence: An Evolving Synergy. Copyright © 2009, Association for the Advancement of Artificial Intelligence. All rights reserved.

关键词： Human robot interaction

来源：评论

学校读者我要写书评

暂无评论

Abstracts from the 2011 Joint Annual Meeting of the Society for Northwestern Vertebrate Biology and Washington Chapter of the Wildlife Society, Held at the Wesley Inn, Gig Harbor, Washington, March 23–25, 2011

引用

Northwestern Naturalist 2011年第2期92卷 136-166页

作者： Michael J. Adams Christopher A. Pearl Jessica Y. Adkins Daniel D. Roby Ladd Bayliss Peter J. Loschl Donald E. Lyons Yasuko Suzuki Hannah E. Anderson Sarah T. Hamman Keith B. Aubry Catherine M. Raley John J. Rohrer Eric C. Lofroth Scott H. Fitkin Michael L. Best Hartwell H. Welsh Jamie B. Bettaso Don T. Ashton Hartwell H. Welsh Scott McBain Lindsay M. Biga Andrew R. Blaustein Susan F. Brady R. Steven Wagner Daniel J. Selski James E. Johnson R. Bruce Bury Wynn W. Cudmore Hartwell H. Welsh Nathan D. Chelgren Tara Chestnut Chaucney W. Anderson Julie Kirshtein Megan T. Cook Tiffany S. Garcia Stephen Corn Erin Muths Amanda Kissel Rick Scherer Eric Delvin Jonathan D. Bakker Peter W. Dunwiddie Diana L. Dishman Deborah A. Duffield Harriet R. Huber Dyanna M. Lambourn Karen M. Dvornich Greg Falxa Gary M. Fellers Patrick M. Kleeman David Miller Brandon Fessler Jason T. Irwin Daniel D. Beck R. Steven Wagner Marc P. Hayes John A. Frew Christian E. Grue Chris R. Friesen Robert T. Mason Stevan J. Arnold Suzanne Estes Tiffany S. Garcia Katie M. Dugger Josh Johnson Mike Rochelle A. J. Kroll Stephanie S. Gervasi Caren S. Goldberg Dan Davis Erica Bree Rosenblum Bill Bosworth Lisette P. Waits Purnima Govindarajulu Gregory A. Green Steve Negri Jennifer R. Griffiths Daniel E. Schindler Christian E. Grue Karen M. Dvornich Adam G. Hansen David A. Beauchamp Casey M. Baldwin Marc P. Hayes Gretchen Padgett-Flohr Blake R. Hossack Winsor H. Lowe Paul Stephen Corn Aaron N. Johnston Kris Kendell Dave Prescott Scott Stevens Peter M. Kiffney Carol Volk Kerensa A. King Christian E. Grue James M. Grassley Andrew J. Kroll Matt Hane Josh Johnston Mike Rochelle Stuart Farber Niels Leuthold Michael J. Adams John P. Hayes Bo Li Michael T. Brett Kent B. Livezey Ilon E. Logan Teresa J. Lorenz Kimberly A. Sullivan Amanda V. Bakian Deanna Lynch Nancy Thomas Krysten Schuler Steven Jeffries Joshua Malt Kelly R. McAllister Joanne P. Schuett-Hames Aimee P. McIntyre Jay E. Jones Eric M. Lund Frithiof T. Waterstrat Jack N. Giovanini Stephen D. Duke Marc P. Hayes US Forest Service Pacific Northwest Research Station Olympia WA 98512 kaubry@fs.fed.us US Forest Service Okanogan-Wenatchee National Forest Methow Valley Ranger District Winthrop WA 98862 British Columbia Ministry of Environment Victoria BC V8W9M1 Washington Department of Fish and Wildlife Winthrop WA 98862 Humboldt State University 1 Harpst St. Arcata CA 95521 addsmike14@*** US Forest Service Pacific Southwest Research Station 1700 Bayside Dr. Arcata CA 95521 hwelsh@fs.fed.us US Fish and Wildlife Service Arcata Field Office 1655 Heindon Road Arcata CA 95521 jamie_bettaso@fws.gov Redwood Sciences Laboratory US Forest Service1700 Bayview Drive Arcata CA 99521 dashton@fs.fed.us hwelsh@fs.fed.us McBain &amp Trush 980 7th Street Arcata CA 95521 scott@*** Oregon State University Environmental Sciences Graduate Program Corvallis OR 97331 lindsay.biga@science.oregonstate.edu Oregon State University Department of Zoology Corvallis OR 97331 US Geological Survey Forest and Rangeland Ecosystem Science Center 3200 SW Jefferson Way Corvallis OR 97331 buryb@usgs.gov Life Science Department Chemeketa Community College Salem OR 97309 wynn.cudmore@chemeketa.edu US Forest Service Redwood Sciences Laboratory 1700 Bayview Drive Arcata CA 95521 hwelsh@fs.fed.us USGS Oregon Water Science Center 2130 SW 5th Avenue Portland OR 97207 chestnut@usgs.gov USGS Headquarters 12201 Sunrise Valley Drive Reston VA 20192 US Geological Survey Northern Rocky Mountain Science Center Aldo Leopold Wilderness Research Institute 790 E. Beckwith Avenue Missoula MT 59801 scorn@usgs.gov US Geological Survey Fort Collins Science Center 2150 Centre Avenue Building C Fort Collins CO 80526 Department of Biological Sciences Simon Fraser University Burnaby BC V5A 1S6 Colorado State University Department of Fishery and Wildlife Biology Fort Collins CO 80523 The Nature Conservancy 120 Union Ave SE Olympia WA 98501 edelvin@tnc.org School of Forest Resources University of Washington Seattle WA

来源：评论

学校读者我要写书评

暂无评论

GridRT: A Massively Parallel Architecture for Ray-Tracing Using Uniform Grids

GridRT: A Massively Parallel Architecture for Ray-Tracing Us...

引用

Euromicro Symposium on Digital System Design

作者： Alexandre Solon Nery Nadia Nedjah Felipe Maia Galvão Franca Systems Engineering and Computer Science Program Universidade Federal do Rio de Janeiro Brazil Department of Electronics Engineering and Telecommunications Universidade do Estado do Rio de Janeiro Brazil

In this paper, we propose an architecture, which we call GridRT, capable of dealing with the main features, such as shadows and reflections effects, of Ray Tracing used for rendering three-dimensional scenes. This architecture achieves an efficient overall performance yet using a simple and compact massively parallel design. The design exploits the usage of Xilinx ® Floating Point Operator IP Core and the spatial data structure of Regular Grids.

关键词： Parallel architectures Ray tracing Layout computer architecture Rendering (computer graphics) Optical reflection Data structures computer graphics Pipelines Pixel

来源：评论

学校读者我要写书评

暂无评论

Analysis and balancing of social network to improve the knowledge flow on multidisciplinary teams

Analysis and balancing of social network to improve the know...

引用

International Conference on computer Supported Cooperative Work in Design

作者： Rafael Studart Monclar Jonice Oliveira Jano Moreira de Souza Graduate School and Research in Engineering (COPPE)-Department of Computer and Systems Engineering (PESC) Federal University of Rio de Janeiro Rio de Janeiro Brazil Institute of Mathematics and Statistics (IME)-Informatics and Computer Science Department(DICC) UERJ-State of Rio de Janeiro University Rio de Janeiro Rio de Janeiro Brazil

ISBN: (纸本)9781424435340

Man as a social being, as a being in social relations, is in constant motion. Such mobility affects the social networks that Man builds throughout one's existence. Networks that can consist of dozens, hundreds or even thousands of other people, with various degrees of mobility. During the formation of such networks, problems can arise, such as elements that concentrate many relationships, very isolated individuals or peripheral members of a network, people who are the only link between two distinct groups, agglomerations of people in isolated points. This can cause a series of losses to the most important element that flows through social networks: knowledge. In scientific social networks, this assertion takes even more importance, mainly on account of the mobility of researchers and the excess of knowledge circulating in it, making it more vulnerable to the movements of Man. It is with the intent of solving this problem that our work seeks to achieve success, as it analyzes the scientific social networks based on the GCC tool detects the problems related to them, and suggests recommendations of relationships to users considered harmful to the flow of knowledge in the network. We call this process of social network balancing. For the evaluation of this work we conducted a comparison with several similar proposals, and developed a working prototype, which in turn was used to make our case studies.

关键词： Social network services Knowledge engineering computer networks Design engineering systems engineering and theory Knowledge management Collaborative work Telephony Mathematics Statistical analysis

来源：评论

学校读者我要写书评

暂无评论

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案：

请选择收藏分类：

通借通还

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：