检索结果-内蒙古大学图书馆

A Simulation Model for the Compression of Audio Information

International Journal of Modelling & Simulation 1996年第1期16卷 21-21页

作者： Kwong, S. Man, K. F. Department of Computer Science City University of Hong Kong Kowloon Hong Kong Department of Electronic Engineering City University of Hong Kong Kowloon Hong Kong University of Waterloo Control Data Canada Bell Northern Research City University of Hong Kong Department of Computer Science Cranfield Institute of Technology United Kingdom UK Aerospace Industry Electronic Engineering Department City University of Hong Kong IFAC Real-time Control Computing Working Group IFAC IEEE

Advances in signal processing allow us to model the audio signal in terms of mathematical representation. Compressed audio signal are also important for low-bit-rate media in order to minimize transmission cost. Applications such as movies on compact disc, audio conferencing, and digital television also require a good model for the audio compression. We present a model for compressed audio signal. By varying different modelling parameters, we obtain the simulation result of the proposed model of the audio coder. Simulation results found that it has a good compression Ssignal-to-noise ratio compared with NICAM, CD, and OCF coders.

关键词： Adaptive transform coding Discrete cosine transform Extended lapped transform Modified hermite transform Signal-to-noise ratio

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

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： Memory Operating systems Control systems

来源：评论

学校读者我要写书评

暂无评论

computing time-DELAY AND ITS EFFECTS ON real-time CONTROL-SYSTEMS

引用

IEEE TRANSACTIONS ON CONTROL SYSTEMS TECHNOLOGY 1995年第2期3卷 218-224页

作者： SHIN, KG CUI, XZ Real-Time Computing Laboratory Division of Comuuter Science and Engineering. Department of Electrical Engineering and Computer Science University of Michigan Ann Arbor MI USA

The reliability of a real-time digital control computer depends not only on the reliability of the hardware and software used, but also on the time delay in computing the control output, because of the negative effects of computing time delay on control system performance. For a given fixed sampling interval, the effects of computing time delay are classified into the delay and loss problems, The delay problem, occurs when the computing time delay is nonzero but smaller than the sampling interval, while the loss problem occurs when the computing time delay is greater than, or equal to, the sampling interval, i,e., loss of the control output, These two problems are analyzed as a means of evaluating real-time control systems, First, a generic analysis of the effects of computing time delay is presented along with necessary conditions for system stability, Then, we present both qualitative and quantitative analyses of the computing time delay effects on a robot control system, deriving upper bounds of the computing time delay with respect to system stability and system performance.

关键词： Delay effects real time systems Control systems Sampling methods System performance Stability analysis Digital control Hardware Software performance Performance analysis

来源：评论

学校读者我要写书评

暂无评论

PROBING AND FAULT INJECTION OF DEPENDABLE DISTRIBUTED PROTOCOLS

引用

computer JOURNAL 1995年第4期38卷 286-300页

作者： DAWSON, S JAHANIAN, F Real-Time Computing Laboratory Electrical Engineering and Computer Science Department University of Michigan Ann Arbor MI 48109-2122 United States

Ensuring that a distributed system with strict dependability constraints meets its prescribed specification is a growing challenge that confronts software developers and system engineers. This paper presents a technique for probing and fault injection of fault-tolerant distributed protocols. The proposed technique, called script-driven probing and fault injection, can be used for studying the behaviour of distributed systems and for detecting design and implementation errors of fault-tolerant protocols. The focus of this work is on fault injection techniques that can be used to demonstrate three aspects of a target protocol: detection of design or implementation errors;identification of violations of protocol specifications;and insight into design decisions made by the implementers. The emphasis of our approach is on experimental techniques intended to identify specific ''problems'' in a protocol or its implementation rather than the evaluation of system dependability through statistical metrics such as fault coverage. To demonstrate the capabilities of this technique, the paper describes a probing and fault injection toot, called the PFI tool (probe/fault injection tool), and a summary of several extensive experiments that studied the behaviour of two protocols: the Transmission Control Protocol (TCP) and a group membership protocol (GMP).

关键词：

来源：评论

学校读者我要写书评

暂无评论

Deterministic fault injection of distributed systems

引用

International Workshop on Theory and Practice in Distributed Systems

作者： Dawson, S Jahanian, F Real-Time Computing Laboratory Electrical Engineering and Computer Science Department University of Michigan Ann Arbor 48109-2122 MI United States

ISBN: (纸本)3540600426

Ensuring that a system meets its prescribed specification is a growing challenge that confronts software developers and system engineers. Meeting this challenge is particularly important for distributed systems with strict dependability and timeliness constraints. This paper presents a technique, called script-driven probing and fault injection, for the evaluation and validation of dependable protocols. The proposed approach can be used to demonstrate three aspects of a target protocol: i) detection of design or implementation errors, ii) identification of violations of protocol specifications, and iii) insight into design decisions made by the implementers. To demonstrate the capabilities of this technique, the paper briefly describes a probing and fault injection tool called the PFI tool, and several experiments on two protocols: the Transmission Control Protocol (TCP) [4, 24] and the Group Membership Protocol (GMP) [19]. The tool can be used to delay, drop, reorder, duplicate, and modify messages. It can also introduce new messages into the system to probe participants. In the case of TCP, we used the PFI tool to duplicate the experiments reported in [7] on several TCP implementations without access to the vendors' TCP source code in a very short time. We also ran several new experiments that are difficult to perform using past approaches based on packet monitoring and filtering. In the case of GMP, we used the tool to test the fault-tolerance capabilities of an implementation under various failure models including daemon/link crash, send/receive omissions, and timing failures. Furthermore, by selective reordering of messages and spontaneous transmission of new messages, we were able to guide a distributed computation into hard to reach global states without instrumenting the protocol implementation.

关键词： Transmission control protocol

来源：评论

学校读者我要写书评

暂无评论

PP-MESS-SIM: A simulator for evaluating multicomputer interconnection networks 28

PP-MESS-SIM: A simulator for evaluating multicomputer interc...

引用

28th Annual Simulation Symposium, ANSS 1995

作者： Rexford, Jennifer Dolter, James Feng, Wu-chang Shin, Kang G. Real-Time Computing Laboratory Department of Electrical Engineering and Computer Science University of Michigan Ann ArborMI48109-2122 United States

ISBN: (纸本)0818670916

This paper presents pp-mess-sim, an object-oriented discrete-event simulation environment for evaluating multicomputer networks. The simulator provides a toolboz of various network topologies, communication workloads, routing-switching algorithms, and router models. These router models can vary from high-level architectures to low-level specification of actual devices. By decoupling individual parts of the code, pp-mess-sim enables independent code development and creates a flexible and extensible environment for evaluating different aspects of network design. Sample simulation experiments capitalize on this flezibility to compare routing-switching schemes under various application workloads. © 1995 IEEE

关键词： Discrete event simulation

来源：评论

学校读者我要写书评

暂无评论

QoS-Sensitive protocol processing in shared-memory multiprocessor multimedia servers 3

QoS-Sensitive protocol processing in shared-memory multiproc...

引用

3rd IEEE Workshop on the Architecture and Implementation of High Performance Communication Subsystems, HPCS 1995

作者： Mehra, A. Shin, Kang G. Real-Time Computing Laboratory Department of Electrical Engineering and Computer Science University of Michigan Ann ArborMI48109-2122 United States

来源：评论

学校读者我要写书评

暂无评论

Non-preemptive scheduling of messages on controller area network for real-time control applications

Non-preemptive scheduling of messages on controller area net...

引用

1995 real-time Technology and Applications Symposium, RTAS 1995

作者： Zuberi, Khawar M. Shin, Kang G. Real-Time Computing Laboratory Department of Electrical Engineering and Computer Science University of Michigan Ann Arbor MI 48109-2122 United States

Scheduling messages on the controller area network (CAN) corresponds to assigning identifiers (IDs) to messages according to their priorities. If fixed priority scheduling such as deadline monotonic (DM) is used to calculate these priorities, then in general, it will result in low schedulability. Dynamic scheduling schemes such as earliest deadline (ED) can give greater schedulability, but they are not practical for CAN because if the ID is to reflect message deadlines then a long ID must be used. This increases the length of each message to the point that ED is no better than DM. Our solution to this problem is the mixed traffic scheduler (MTS), which is a cross between ED and DM, and provides high schedulability without needing long IDs. Through simulations, we compare the performance of MTS with that of DM and ED* (an imaginary scheduler which works like ED, except it needs only short IDs). We use a realistic workload in our simulations based on messages typically found in computer integrated manufacturing. Our simulations show that MTS performs much better than DM and at the same level as ED, except under high loads and tight deadlines, when ED* is superior. © 1995 IEEE.

关键词： real time control

来源：评论

学校读者我要写书评

暂无评论

OPEN FAULTS IN BICMOS GATES

引用

IEEE TRANSACTIONS ON computer-AIDED DESIGN OF INTEGRATED CIRCUITS AND SYSTEMS 1995年第5期14卷 567-575页

作者： MA, SC MCCLUSKEY, EJ Center for Reliable Computing Computer Systems Laboratory Department of Electrical Engineering and Computer Science University of Stanford Stanford CA USA

Opens in BICMOS structures are analyzed here. It is shown that some opens cannot be detected by stuck-fault or other functional tests, since some transistors in BiCMOS gates do not affect the logical function of the gate. A switch-level model for CMOS circuits is extended to include bipolar devices. With this switch-level model, opens that cannot be detected by stuck-faults or other functional tests are easily identified. It is also shown that, in BICMOS circuits, an open defect in one transistor can accelerate the wearout of another nondefective transistor.

关键词： BiCMOS integrated circuits Circuit faults Circuit testing Semiconductor device modeling Logic testing Delay MOSFETs Switching circuits Acceleration CMOS technology

来源：评论

学校读者我要写书评

暂无评论

A distributed table-driven route selection scheme for establishing real-time video channels

A distributed table-driven route selection scheme for establ...

引用

International Conference on Distributed computing Systems

作者： Chih-Che Chou K.G. Shin Real-Time Computing Laboratory Department of Electrical Engineering and Computer Science University of Michigan Ann Arbor MI USA

To guarantee the delivery of real-time messages before their deadline, a real-time connection or channel must be established before the transmission of any real-time messages. During this channel-establishment phase, one must first select a route between the source and destination of this channel and then reserve sufficient resources along this route so that the worst-case end-to-end delay over the selected route may not exceed the user-specified delay bound. We propose a table-driven distributed route-selection scheme that is guaranteed to find a "qualified" route, if any, that meets the performance requirement of the requested channel without compromising any of the existing guarantees. The proposed scheme uses the Bellman-Ford shortest path algorithm to build real-time delay tables, and hence, can solve the route-selection problem by a simple table look-up. Several examples are presented to demonstrate the effectiveness of the proposed distributed route-selection scheme.

关键词： Delay

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：