检索结果-内蒙古大学图书馆

Realizations of focus invariance in optical-digital systems with wave-front coding

APPLIED OPTICS 1997年第35期36卷 9157-9166页

作者： Bradburn, S Cathey, WT Dowski, ER The authors are with the Imaging Systems Laboratory Opto-electronic Computing Systems Center Department of Electrical and Computer Engineering University of Colorado at Boulder Boulder Colorado 80309-0525.

We report experimental verification of an extended depth of focus (EDF) system with near-diffraction-limited performance capabilities. Dowski and Cathey [Appl. Opt. 34, 1859-1866 (1995)] described the theory of this system in detail. We can create an EDF system by modifying a standard incoherent optical system with a special cubic phase plate placed at the aperture stop. We briefly review the theory and present the first optical experimental verification of this EDF system. The phase plate codes the wave front, producing a modified optical transfer function. Once the image is transformed into digital form, a signal-processing step decodes the image and produces the final in-focus image. We have produced a number of images from various optical systems using the phase plate, thus demonstrating the success of this EDF system. (C) 1997 Optical Society of America.

关键词： extended depth of focus focus invariant optical-digital imaging systems image formation

来源：评论

学校读者我要写书评

暂无评论

Dust & magnet: Multivariate information visualization using a magnet metaphor

引用

Information Visualization 1997年第4期4卷 239-256页

作者： Yi, Ji Soo Melton, Rachel Stasko, John Jacko, Julie A. Laboratory for Human–Computer Interaction and Health Care Informatics School of Industrial and Systems Engineering Georgia Institute of Technology Atlanta GA United States College of Computing/GVU Center Georgia Institute of Technology Atlanta GA United States

The use of multivariate information visualization techniques is intrinsically difficult because the multidimensional nature of data cannot be effectively presented and understood on real-world displays, which have limited dimensionalities. However, the necessity to use these techniques in daily life is increasing as the amount and complexity of data grows explosively in the information age. Thus, multivariate information visualization techniques that are easier to understand and more accessible are needed for the general population. In order to meet this need, the present paper proposes Dust & Magnet, a multivariate information visualization technique using a magnet metaphor and various interactive techniques. The intuitive magnet metaphor and subsequent interactions facilitate the ease of learning this multivariate information visualization technique. A visualization tool such as Dust & Magnet has the potential to increase the acceptance of and utility for multivariate information by a broader population of users who are not necessarily knowledgeable about multivariate information visualization techniques. © 2005, SAGE Publications. All rights reserved.

关键词： interaction magnet metaphor Multivariate information visualization

来源：评论

学校读者我要写书评

暂无评论

Reducing uncertainty about common-mode failures

Reducing uncertainty about common-mode failures

引用

International Symposium on Software Reliability Engineering (ISSRE)

作者： J. Voas A. Ghosh F. Charron L. Kassab Reliable Software Technologies Corporation Sterling VA USA Naval Research Laboratory Center for High Assurance Computer Systems Washington D.C. DC USA

Multi-version programming is employed in fault-tolerant computer systems in order to provide protection against common-mode failure in software. Multi-version programming involves building diverse software implementations of critical functions. The premise of building diverse versions is that the likelihood of a programming error in one version causing a failure in an identical manner as an error in another version is reduced. Skeptics of multi-version programming have correctly pointed out that common-mode failures between redundant diverse versions can reduce the return on investment in creating diverse versions. To date, other than using historical data from other projects, there has been no way to estimate the potential for a given multi-version programming system to suffer a common-mode failure. This paper presents an algorithm and software analysis prototype to reduce the uncertainty of whether software flaws in diverse versions can result in common-mode failure. The analysis uses software fault-injection techniques to subject one or more versions to anomalous behavior. From this, we can predict how the software will behave if real faults exist in the multiple versions.

关键词： Uncertainty computer errors Fault tolerant systems Protection Functional programming Investments Software algorithms Failure analysis Algorithm design and analysis Software prototyping

来源：评论

学校读者我要写书评

暂无评论

Parallel global routing algorithms for standard cells

Parallel global routing algorithms for standard cells

引用

International Symposium on Parallel Processing

作者： Z. Xing J. Chandy P. Banerjee Computer and Systems Research Laboratory University of Illinois Urbana IL USA Cadence Design Systems Chelmsford MA USA Center for Parallel and Distributed Computing Northwestern University Evanston IL USA

In this paper, we propose three different parallel algorithms based on a state-of-the-art global router called TimberWolfSC. The parallel algorithms have been implemented by using the Message Passing Interface (MPI), and have been evaluated on a wide range of parallel platforms such as the Sun Sparccenter 1000 and the Intel Paragon. Our experimental results show good speedups and qualities from two of these parallel algorithms. We have been able to reduce runtimes of some circuits from half an hour to 5 minutes, obtained speedups of about 4.0 to 5.0 on 8 processors, with less than 2-3% degradation of quality of the solutions.

关键词： Routing Parallel algorithms Distributed computing Message passing Pins Wire Contracts Concurrent computing Laboratories Sun

来源：评论

学校读者我要写书评

暂无评论

Using ZPL to develop a parallel chaos router simulator 96

Using ZPL to develop a parallel chaos router simulator

引用

1996 Winter Simulation Conference (WSC 96)

作者： Richardson, W Bailey, ML Sanders, WH Department of Electrical and Computer Engineering University of Arizona Tucson AZ Computer Science Department University of Arizona Tucson AZ Center for Reliable and High-Performance Computing Coordinated Science Laboratory University of Illinois at Urbana-Champaign Urbana IL

ISBN: (纸本)0780333837

This paper reports on our experience in writing a parallel version of a chaos router simulator using the new data-driven parallel language ZPL. The simulator is a large program that tests the capabilities of ZPL. The (parallel) ZPL program is compared with the existing serial implementation on two very different architectures: a 16-processor Intel Paragon and a cluster of eight Alpha workstations. On the Paragon, the simulator performs best when simulating medium- to large-sized routers, and on the Alpha cluster, it performs best when simulating large routers. Thus a user can choose the parallel platform best suited to the router size.

关键词： Parallel processing systems

来源：评论

学校读者我要写书评

暂无评论

Parallel algorithms for force directed scheduling of flattened and hierarchical signal flow graphs

Parallel algorithms for force directed scheduling of flatten...

引用

IEEE International Conference on computer Design: VLSI in computers and Processors, (ICCD)

作者： P. Prabhakaran P. Banerjee Center for Reliable and High-Performance Computing Coordinated Science Laboratory University of Illinois Urbana IL USA Center for Parallel and Distributed Computing Department of Electrical and Computer Engineering Northwestern University Evanston IL USA

In this paper we present some novel algorithms for scheduling hierarchical signal flow graphs in the domain of high-level synthesis. There are several key contributions of this paper. First, we develop a novel extension of the force directed scheduling problem which naturally handles loops and conditionals by coming up with a scheme of scheduling hierarchical signal flow graphs. Second, we develop three new parallel algorithms for the scheduling problem. Third, our parallel algorithms are portable across a wide range of parallel platforms. We report results on a set of high-level synthesis benchmarks on 8-processor SGI Challenge and a network of 4 SUN SPARCstation5 work stations. Finally, while some parallel algorithms for VLSI CAD reported by earlier researchers have reported a loss of qualities of results, our parallel algorithms produce exactly the same results as the sequential algorithms on which they are based.

关键词： Parallel algorithms Flow graphs Processor scheduling Concurrent computing Scheduling algorithm Contracts Cost function Broadcasting

来源：评论

学校读者我要写书评

暂无评论

Fault/failure analysis of the Tandem NonStop-UX operating system

Fault/failure analysis of the Tandem NonStop-UX operating sy...

引用

Conference on Digital Avionics systems (DASC)

作者： R.K. Iyer Mei-Chen Hsueh I. Lee Center for Reliable and High-Performance Computing Coordinated Science Laboratory University of Illinois Urbana IL USA Systems Development Group Tandem Computers Inc.orporated Cupertino CA USA

This paper presents the results of an analyse's of failures in several releases of Tandem's NonStop-UX operating system. NonStop-UX is based on UNIX System V. The analysis covers software failures from the field and failures reported by Tandem's test center. Faults are classified based on the status of the reported failures, the locations of the code that detected the problems, the panic messages generated by the systems, the faulty source modules, and the types of developer's mistakes. We present distributions of the failure and repair times for unique and duplicate failures. We also discuss how the analysis results can be used for assessing the dependability of the operating system and guiding improvement efforts.

关键词： Failure analysis Operating systems Kernel System testing computer crashes Software testing Fault detection Hardware Data structures Information analysis

来源：评论

学校读者我要写书评

暂无评论

Numerical performability evaluation of a group multicast protocol

引用

Distributed systems Engineering 1996年第1期3卷 39-52页

作者： Malhis, Luai M. Sanders, William H. Schlichting, Richard D. Center for Reliable and High-Performance Computing Coordinated Science Laboratory University of Illinois Urbana-Champaign IL 61801 United States Department of Computer Science University of Arizona Tucson AZ 85721 United States

Multicast protocols that provide message ordering and delivery guarantees are becoming increasingly important in distributed system design. However, despite the large number of such protocols, little analytical work has been done concerning their performance, especially in the presence of message loss. This paper illustrates a method for determining the performability of group multicast protocols using stochastic activity networks, a stochastic extension to Petri nets, and reduced base model construction. In particular, we study the performability of one such protocol, called Psync, under a wide variety of workload and message loss probabilities. The specific focus is on measuring two quantities, the stabilization time - that is, the time required for messages to arrive at all hosts - and channel utilization. The analysis shows that Psync works well when message transmissions are frequent, but it exhibits extremely long message stabilization times when transmissions are infrequent and message losses occur. We use this information to suggest a modification to Psync that greatly reduces stabilization time in this situation. The results provide useful insights into the behaviour of Psync, as well as serving as a guide for evaluating the performability of other group multicast protocols. © 1996 The British computer Society,.

关键词：

来源：评论

学校读者我要写书评

暂无评论

Virtual memory versus file interfaces for large, memory-intensive scientific applications 96

Virtual memory versus file interfaces for large, memory-inte...

引用

Proceedings of the 1996 ACM/IEEE conference on Supercomputing

作者： Yoonho Park Ridgway Scott Stuart Sechrest High Performance Computing Center University of Houston Houston TX Software Systems Research Laboratory Department of Electrical Engineering and Computer Science University of Michigan Ann Arbor MI

ISBN: (纸本)9780897918541

Scientific applications often require some strategy for temporary data storage to do the largest possible simulations. The use of virtual memory for temporary data storage has received criticism because of performance problems. However, modern virtual memory found in recent operating systems such as Cenju-3/DE give application writers control over virtual memory policies. We demonstrate that custom virtual memory policies can dramatically reduce virtual memory overhead and allow applications to run out-of-core efficiently. We also demonstrate that the main advantage of virtual memory, namely programming simplicity, is not lost.

关键词： custom policies

来源：评论

学校读者我要写书评

暂无评论

Virtual Memory versus File Interface for Large, Memory-Intensive Scientific Applications

Virtual Memory versus File Interface for Large, Memory-Inten...

引用

Supercomputing Conference

作者： Yoonho Park R. Scott S. Sechrest High performance computing center University of Houston Houston TX USA Software Systems Research Laboratory Department of Electrical Engineering and Computer Science University of Michigan Ann Arbor MI USA

关键词： Memory Operating systems Control systems

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：