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Performance of the H.263 Video Compression Standard

Journal of VLSI Signal Processing Systems for Signal, Image, and Video Technology 1997年第2-3期17卷 101-111页

作者： Girod, Bernd Steinbach, Eckehard Färber, Nikolaus Telecommunications Institute University of Erlangen-Nuremberg 91058 Erlangen Cauerstrasse 7 Germany Georgia Institute of Technology United States University of Hannover Germany Inst. F. Theor. N. University of Hannover Germany Massachussetts Inst. of Technology Cambridge MA United States Research Laboratory of Electronics United States Department of Media Technology Media Laboratory Germany Department of Computer Graphics Germany Academy of Media Arts Cologne Germany Computer Science Section Cologne University Germany Digital Signal Processing Group Georgia Institute of Technology Atlanta GA United States Dept. of Elec. Eng./Telecom. University of Erlangen-Nuremberg Germany Telecommunications Institute Germany Vivo Software Inc. Waltham MA United States University of Karlsruhe Germany University of Essex United Kingdom ESIEE Paris France Image Communication Group Telecommunications Institute University of Erlangen-Nuremberg Germany University of Munich Germany Telecommunications Institute University of Erlangen-Nuremberg Germany Image Communication Group

The draft international standard ITU-T H.263 is closely related to the well known and widely used ITU-T Recommendation H.261. However, H.263 does provide the same subjective image quality at less than half the bit-rate. In this paper we investigate to what extend single enhancements of H.263 contribute to this performance gain, and consider the trade-off quality vs. complexity. Based on typical test sequences, H.263 with its various modes is compared to H.261 on the basis of rate distortion curves at bit-rates up to 128 kbps. At 64 kbps, the performance gain of H.263 in its default mode compared to H.261 is approximately 2 dB. This improvement is achieved with only little increase of complexity, and is mainly due to more accurate motion compensation with half-pel accuracy. Considering the trade-off quality vs. complexity, the combination of the optional coding-modes "Advanced prediction mode" and "PB-frames mode" is a good compromise, resulting in an additional performance gain of 1.5 dB PSNR at 64 kbps. The "Syntax-based arithmetic coding mode" on the other hand, offers only a very small performance gain (0.1 dB at 64 kbps) for its increased computational complexity. Results from profiling an H.263 software codec are presented in order to support complexity considerations of the optional coding-modes.

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Developing a prototype concurrent design tool for composite topside structures

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NAVAL ENGINEERS JOURNAL 1997年第3期109卷 279-290页

作者： Dirlik, S Hambric, S Azarm, S Marquardt, M Hellman, A Bartlett, S Castelli, V Steve Dirlik:began his career at the Naval Surface Warfare Center Carderock Division in 1981 as an aerospace engineer co-op student. He completed his bachelor of science degree in aeropace and ocean engineering from Virginia Polytechnic Institute and State University in 1985 and his master of science degree in aerospace engineering from the University of Maryland in 1990. Mr. Dirlik recently completed a master of science program in applied physics at The Johns Hopins University and currently works in the Radar Cross Section and Target Physics Branch of the Signatures Directorate at the Naval Surface Warfare Center Corderoke Division. He has worked on Navy low observable programs since 1990. Stephen Hambric:is a research associate at the Applied Research Laboratory at The Pennsylvania State University. He received his B. S. and M.S. degree in mechanical engineering from Virginia Polytechnic Institute and State University and his D. Sc. in mechnical engineering from the George Washington University. He has worked on several computer aided multidiscikplinary design and optimization projects over the years including an automated propeller design system and a structural acoustic optimization capability. Dr. Shpour Azarm:is currently working as an associate professor with the Design and Manufacturing Group of the Department of Mechanical Engineering at the University of maryland at College Park. Dr Azarm's expertise is in the areas of optimization-based designed and concurrent design and optimization of multidisciplinary systems. He was a consultant at Black & Decker Corporation (summer 1996) and worked as a Navy senior summer faculty fellow (summer 1995) and a NASA summer faculty fellow (summer 1994). He was a visiting scientist at NASA Langley Research Center for Multidisciplinary Analysis and Applied Structural Optimzatiom at the University of Siegen in Germany (spring 1992) and the Design Institute of the Technical University of Denmark (summer 1990). Dr Azarm was an associate technical editor of the ASME Jour

A prototype concurrent engineering tool has been developed for the preliminary design of composite topside structures for modern navy warships. This tool, named GELS for the Concurrent Engineering of Layered Structures, provides designers with an immediate assessment of the impacts of their decisions on several disciplines which are important to the performance of a modern naval topside structure, including electromagnetic interference effects (EMI), radar cross section (RCS), structural integrity, cost, and weight. Preliminary analysis modules in each of these disciplines are integrated to operate from a common set of design variables and a common materials database. Performance in each discipline and an overall fitness function for the concept are then evaluated. A graphical user interface (GUI) is used to define requirements and to display the results from the technical analysis modules. Optimization techniques, including feasible sequential quadratic programming (FSQP) and exhaustive search are used to modify the design variables to satisfy all requirements simultaneously. The development of this tool, the technical modules, and their integration are discussed noting the decisions and compromises required to develop and integrate the modules into a prototype conceptual design tool.

关键词： Warships

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Zoom navigation exploring large information and application spaces 96

Zoom navigation exploring large information and application ...

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3rd International Workshop on Advanced Visual Interfaces, AVI 1996

作者： Rüger, Michael Preim, Benihard Ritier, Alf Department of Simulation and Graphics Faculty of Computer Science Otto-von-Guericke University of Magdeburg P.O. BOX 4120 D-39016 Magdeburg Germany

ISBN: (纸本)0897918347

We present the concept of ZOOM NAVIGATION, a new interaction paradigm to cope with visualization and navigation problems as found in large information and application spaces. It is based on the pluggable zoom, an object-oriented component derived from the variable zoom fisheye algorithm. Working with a limited screen space we apply a degree-of-inierest (DOI) function to guide the level of detail used in presenting information. Furthermore we determine the user's information and navigation needs by analysing the interaction history. This leads to the definition of the aspect-of-interest (AOI) function. The AOI is evaluated in order to choose one of the several information aspects, under which an item can be studied. This allows us to change navigational affordance and thereby enhance navigation. In this paper we describe the ideas behind the pluggable zoom and the definition of DOI and AOI functions. The application of these functions is demonstrated within two case studies, the ZOOM ILLUSTRATOR and the ZOOM NAVIGATOR. We discuss our experience with these implemented systems. © 1996 ACM.

关键词： Navigation

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Sensitivity analysis of iterative design processes

Sensitivity analysis of iterative design processes

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IEEE International Conference on computer-Aided Design

作者： E.W. Johnson J.B. Brockman R. Vigeland Department of Computer Science and Engineering University of Notre Dame USA Mentor Graphics Corporation USA

As design processes continue to increase in complexity, it is important to base process improvements on quantitative analysis. In this paper we develop an analytical approach to analyze sequential design processes using sensitivity analysis. Two applications illustrate this approach, one involving a Pareto analysis of an ASIC design process and the other an optimization of a software design process to determine the lower bound of the process completion time.

关键词： Sensitivity analysis Process design Equations Monitoring computer science Design engineering computer graphics Application software Pareto analysis Application specific integrated circuits

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Parallel programming with CAPSE-a case study

Parallel programming with CAPSE-a case study

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Euromicro Workshop on Parallel and Distributed Processing

作者： B. Gruber G. Haring D. Kranzlmuller J. Volkert Institute of Applied Computer Science and Information Systems Department of Advanced Computer Engineering University of Technology Vienna Vienna Austria Institute of Computer Science Department for Graphics and Parallel Processing Johannes Kepler University Linz Linz Austria

The CAPSE environment for computer Aided Parallel Software Engineering is intended to assist the developer in the crucial task of parallel programming. The methodology of CAPSE is based on direct manipulative graphical creation and editing of scalable workload characterizations of MIMD algorithms. This paper presents the basic concepts of this methodology and an example of a parallel Poisson solver. The workload characterization representing the computation and communication behavior of the algorithm is based on directed acyclic task graphs, which achieve scalability by composing the task graph of scalable basic patterns instead of single node and arcs. The composition and the usage of these basic patterns is described in the light of designing the Poisson solver algorithm. The resulting task graph is used to predict the program's performance on a nCUBE 2 distributed memory machine and the PAPS simulator.

关键词： Parallel programming computer aided software engineering Concurrent computing computer science Information systems Scalability Distributed computing computer graphics Parallel processing Algorithm design and analysis

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An implementation of the Impala programming language

An implementation of the Impala programming language

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IEEE International Conference on Algorithms and Architectures for Parallel Processing (ICAP)

作者： Danru Wang D.B.K. Kiong B. Lian Department of Information Systems and Computer Science National University of Singapore Singapore Silicon Graphics Private Limited Singapore

Impala is a strongly-typed imperative parallel programming language based on CSP. We implement it on SunOS using the multithreading facilities, to obtain a convenient and practical parallel programming tool. In this p... 详细信息

关键词： computer languages Parallel programming Multithreading

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Introduction to Partitioning and Scheduling Minitrack

Introduction to Partitioning and Scheduling Minitrack

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Annual Hawaii International Conference on System sciences (HICSS)

作者： I. Ahmad H.D. Simon Tao Yang Department of Computer Science Honk Kong University of Science and Technology Kowloon Hong Kong China Silicon Graphics Corporation Mountain View CA USA Department of Computer Science University of California Santa Barbara CA USA

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Visualization of water quality data for the Chesapeake Bay 96

Visualization of water quality data for the Chesapeake Bay

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IEEE Conference on Visualization

作者： A.B. Forgang B. Hamann C.F. Cerco Computer Graphics Laboratory Department of Computer Science University of California Davis USA Environmental Laboratory Waterways Experiment Station U.S. Army Corps of Engineers USA

ISBN: (纸本)9780897918640

We discuss a visualization system for the comparison of simulated and measured water quality. The system extends SCIRT (Site Characterization Interactive Research Toolkit), an interactive system originally developed at the NSF Engineering Research Center for Computational Field Simulation at Mississippi State University. The ongoing study of the Chesapeake Bay presents research in 3D visualization of model-data comparisons.

关键词： Data visualization Probes Computational modeling computer science Scattering computer graphics Pollution measurement Interactive systems Military computing Analytical models

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Timing driven placement reconfiguration for fault tolerance and yield enhancement in FPGAs 96

Timing driven placement reconfiguration for fault tolerance ...

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European Design and Test (ED&TC) Conference

作者： A. Mathur C.L. Liu Silicon Graphics Inc. Mountain View CA USA Department of Computer Science University of Illinois Urbana-Champaign IL USA

ISBN: (纸本)9780818674235

The architectural regularity of FPGAs provides an inherent redundancy which can be exploited for fault tolerance and yield enhancement. In this paper we examine the problem of reconfiguring the placement of a circuit on an FPGA to tolerate a given fault pattern in the array of CLBs. The primary objective of the placement reconfiguration is to minimize timing degradation. The concept of a slack neighborhood graph is used as a general tool for timing driven reconfiguration with a low increase in critical path delay. Our algorithm simultaneously achieves both provably low timing degradation and low re-programming cost. For a wide range of fault probabilities and circuits our algorithm successfully reconfigures the placement with less than 1% degradation in the circuit delay.

关键词： Timing Fault tolerance Field programmable gate arrays Circuit faults Degradation Delay Reconfigurable logic Programmable logic arrays Logic circuits Routing

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Categorizing network traffic in update-based protocols on scalable multiprocessors

Categorizing network traffic in update-based protocols on sc...

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International Symposium on Parallel Processing

作者： R. Bianchini T.J. LeBlanc J.E. Veenstra COPPE Systems Engineering UFRJ Brazil Department of Computer Science University of Rochester Rochester NY USA Silicon Graphics Inc. USA

Categorizes the coherence traffic in update-based protocols and shows that, for most applications, more than 90% of all updates generated by such a protocol are unnecessary. We identify application characteristics that generate useless update traffic, and compare the isolated and combined effects of several software and hardware techniques for eliminating useless updates. These techniques include dynamic and static hybrid protocols, a data re-mapping strategy, and coalescing write buffers. Our simulations show that these techniques are effective for different types of useless updates. Overall, software caching (where dynamic data re-mapping is performed under programmer or compiler control) has the potential to significantly increase the percentage of useful traffic in applications. When software caching is not applicable, either the static or the dynamic protocol generates the least useless traffic. Although coalescing write buffers provide great reductions in the total number of messages transferred, these buffers do not necessarily increase the percentage of useful traffic.

关键词： Telecommunication traffic Protocols Application software Traffic control Character generation Hardware Software performance Programming profession Program processors

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