检索结果-内蒙古大学图书馆

International Symposium on Parallel Processing

作者： B. Ramkumar P. Banerjee Department of Electrical & Computer Engineering University of Iowa USA Center for Reliable and High-Perf Computing Coordinated Science Laboratory University of Illinois USA

The authors describe a new portable algorithm for parallel circuit extraction. The algorithm is built as part of the ongoing ProperCAD project: a portable object-oriented parallel environment for CAD applications that is built on top of the CHARM system. The algorithm, unlike prior approaches like PACE is asynchronous and is based on a coarse-grained dataflow execution model. Performance of circuit extraction is presented on four parallel machines: an Encore Multimax, a Sequent Symmetry, a NCUBE 2 hypercube, and a network of Sun Sparc workstations. The extractor runs unchanged on all these machines.< >

关键词： Parallel algorithms Very large scale integration Object oriented modeling Concurrent computing Workstations Circuit testing Runtime library Portable computers Application software Parallel machines

来源：评论

学校读者我要写书评

暂无评论

Generalized agreement between concurrent fail-stop processes 7th

引用

7th International Workshop on Distributed Algorithms, WDAG 1993

作者： Burns, James E. Cruz, Rolando I. Loui, Michael C. College of Computing Georgia Institute of Technology AtlantaGA30332 United States ATS&T Bell Laboratories NapervilleIL60566 United States Department of Electrical and Computer Engineering Coordinated Science Laboratory University of Illinois at Urbane-Champaign UrbanaIL61801 United States Bell Communications Research Red BankNJ07701 United States

ISBN: (纸本)9783540572718

For a system of concurrent processes that can fail by stopping, we study a generalization of the traditional binary agreement problem having more than two possible input values. We provide bounds on the number of possible inputs for which agreement is possible in a system of n concurrent processes that communicate using read-modify-write operations on m shared memory cells of sizes r1,…,rm. Let V be the set of input values. We present an agreement protocol for two processes with (formula presented), where rm=maxj,{rj}. For m=1 and m=2, we prove that this upper bound on |V| is the best possible. A protocol for n processes is fully resilient if it tolerates up to n−1 failures;a fully resilient protocol is wait-free, because no process needs to wait for any other. In a write-once protocol, each memory cell changes value at most once during each execution of the protocol. We present a fully resilient write-once agreement protocol for (formula presented). We show that no fully resilient write-once agreement protocol exists when (formula presented) and n≥m. © Springer-Verlag Berlin Heidelberg 1993.

关键词： Memory architecture

来源：评论

学校读者我要写书评

暂无评论

DERIVATION AND APPLICATION OF HARD DEADLINES FOR real-time CONTROL-SYSTEMS

引用

IEEE TRANSACTIONS ON SYSTEMS MAN AND CYBERNETICS 1992年第6期22卷 1403-1413页

作者： SHIN, KG KIM, HB Real Time Computing Laboratory the Department of Electrical Engineering and Computer Science University of Michigan Ann Arbor MI USA

The computation-time delay in the feedback controller of a real-time control system may cause failure to update the control input during one or more sampling periods. If this delay exceeds a certain limit called a hard deadline, either the necessary conditions for system stability are violated or the system leaves the allowed state-space. In such a case a dynamic failure is said to occur to the system. A method for calculating the hard deadlines in linear time-invariant control systems by considering system stability and the allowed state-space is presented. To derive necessary conditions for (asymptotic) system stability, the state difference equation is modified based on an assumed maximum delay and the probability distribution of delays whose magnitudes are less than, or equal to, the assumed maximum delay. Moreover, the allowed state-space-which is derived from given input and state constraints-is used to calculate the hard deadline as a function of time and the system state. A one-shot delay model in which a single event causes a dynamic failure is also considered. The knowledge of hard deadline is then applied to the design of error recovery in a triple modular redundant (TMR) controller computer.

关键词： real time systems Control systems Delay effects Stability Feedback Sampling methods Difference equations computer errors Error correction Process control

来源：评论

学校读者我要写书评

暂无评论

MINIMUM-time COLLISION-FREE TRAJECTORY PLANNING FOR DUAL-ROBOT SYSTEMS

引用

IEEE TRANSACTIONS ON ROBOTICS AND AUTOMATION 1992年第5期8卷 641-644页

作者： SHIN, KG ZHENG, Q Real-Time Computing Laboratory Department of Electrical Engineering and Computer Science University of Michigan Ann Arbor MI USA

Collision-free multirobot motion planning can be achieved in two steps: path planning and trajectory planning. Path planning finds for the robots geometric paths to avoid collision with static obstacles and trajectory planning determines how fast each robot must move along its geometric path to avoid collision with other moving robots. For a dual-robot system, a simple trajectory planning strategy is to let each robot move along its path as fast as possible and delay one robot at its initial position to avoid collision with the other robot. We derive in this paper a sufficient condition under which this simple (thus easy to implement) strategy for dual-robot systems can achieve time optimality as well as collision avoidance, i.e., the two robots reach their final positions without colliding with each other in the minimum amount of time. A demonstrative example is presented, showing how this strategy can be used for loading and unloading applications.

关键词： COLLISION AVOIDANCE COLLISION REGION MINIMUM-time TRAJECTORY PLANNING MULTIROBOT SYSTEMS

来源：评论

学校读者我要写书评

暂无评论

MONITORING AND DEBUGGING DISTRIBUTED real-time PROGRAMS

引用

SOFTWARE-PRACTICE & EXPERIENCE 1992年第10期22卷 863-877页

作者： DODD, PS RAVISHANKAR, CV Real-Time Computing Laboratory Department of Electrical Engineering and Computer Science The University of Michigan Ann Arbor Michigan 48109-2122 U.S.A.

In this paper we describe the design and implementation of an integrated monitoring and debugging system for a distributed real-time computer system. The monitor provides continuous, transparent monitoring capabilities throughout a real-time system's lifecycle with bounded, minimal, predictable interference by using software support. The monitor is flexible enough to observe both high-level events that are operating system- and application-specific, as well as low-level events such as shared variable references. We present a novel approach to monitoring shared variable references that provides transparent monitoring with low overhead. The monitor is designed to support tasks such as debugging real-time applications, aiding real-time task scheduling, and measuring system performance. Since debugging distributed real-time applications is particularly difficult, we describe how the monitor can be used to debug distributed and parallel applications by deterministic execution replay.

关键词： PROGRAM MONITORING DEBUGGING real-time SYSTEMS

来源：评论

学校读者我要写书评

暂无评论

real-time COMMUNICATION IN LOCAL AREA RING NETWORKS 17

REAL-TIME COMMUNICATION IN LOCAL AREA RING NETWORKS

引用

17TH CONF ON LOCAL computer NETWORKS

作者： ZHENG, Q SHIN, KG Real-Time Computing Laboratory Department of Electrical Engineering and Computer Science University of Michigan Ann Arbor 48109-2122 MI United States

ISBN: (纸本)0818630957

timed token protocols are almost exclusively used for medium access control in local area ring networks. We consider in this paper the feasibility of using buffered transmission which has the advantages of eliminating the token passing overhead and relieving the network interface from the complex token handling operations. By establishing real-time channels (each of which is a unidirectional virtual connection), the end- to-end delivery delay of real-time packets can also be controlled more flexibly than the timed token protocols. We first review the concept of real-time channel (RTC) and the RTC establishment procedures. Its performance is then compared with the FDDI timed token protocol. Our simulation results show that the buffered transmission in local area ring networks equipped with real-time channels enhances both the networks' throughput and the ability to support heterogeneous real-time traffic. The implementation of the network interface is also examined with an example design showing the feasibility of real-time channels in high-speed local area networks. © 1992 IEEE.

关键词： Medium access control

来源：评论

学校读者我要写书评

暂无评论

DESIGN AND EVALUATION OF real-time COMMUNICATION FOR FIELDBUS BASED MANUFACTURING SYSTEMS 17

DESIGN AND EVALUATION OF REAL-TIME COMMUNICATION FOR FIELDBU...

引用

17TH CONF ON LOCAL computer NETWORKS

作者： SHIN, KG CHOU, CC Real-Time Computing Laboratory Department of Electrical Engineering and Computer Science University of Michigan Ann Arbor 48109-2122 MI United States

ISBN: (纸本)0818630957

It is well-known that the ability to support predictable inter-process communication is of great significance to manufacturing and process control systems. In this paper, we propose a strategy for a soon-to-be industrial standard, the SP-50 Field Bus, to support both intra-cell and inter-cell real-time communications. We first describe our strategy in detail and show that it is compatible with the current FieldBus draft proposal. Under our strategy, the capacity of each link is divided into two parts. The first part is managed by the local Link Active Scheduler (LAS) for intra-cell (intra-link) communication. The second part is managed by the global network manager for inter-cell (inter-link) communication. By dividing the link capacity in this way, our strategy can allow for fast local intra-cell connection establishment, while supporting global inter- cell connections. Numerical examples are also given for a typical manufacturing network. © 1992 IEEE.

关键词： computer COMMUNICATION NETWORKS MANUFACTURING SYSTEMS FIELDBUS real-time COMMUNICATION real-time CHANNEL

来源：评论

学校读者我要写书评

暂无评论

Communication-oriented assignment of task modules in hypercubic multicomputers 12

Communication-oriented assignment of task modules in hypercu...

引用

12th International Conference on Distributed computing Systems, ICDCS 1992

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

ISBN: (纸本)0818628650

The problem of mapping a task that is composed of interacting modules onto a hypercube multicomputer is formulated and solved by minimizing an objective function called the communication traffic. The objective function allows module assignments to be found with the usual straightforward combinatorial optimization techniques. The problem of finding an assignment that minimizes the communication traffic is proved to be NP-hard, so a standard state-space search algorithm as well as other heuristic algorithms are used to find optimal/suboptimal solutions. The relative performances of various algorithms are evaluated using simulations. The assignments obtained from these algorithms are evaluated using an event-driven simulator to learn how they perform in real-world execution environments. © 1992 IEEE.

关键词： Heuristic algorithms

来源：评论

学校读者我要写书评

暂无评论

Allocation of periodic task modules with precedence and deadline constraints in distributed real-time systems

Allocation of periodic task modules with precedence and dead...

引用

1992 real-time Systems Symposium, RTSS 1992

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

ISBN: (纸本)0818631953

This papei addresses the problem of allocating (assigning and scheduling) periodic task modules to processing nodes (PNs) in distributed real-time systems subject to task precedence and timing constraints. Using the branch-and-bound technique, a module allocation algorithm (MAA) is proposed to find an "optimal" allocation that maximizes the probability of meeting task deadlines. The task system within a planning cycle is first modeled with a task flow graph (TG) which describes computation and communication modules as well as the precedence constraints among them. To incorporate both timing and logical correctness into module allocation, the probability of meeting task deadlines is used as the objective function. The MAA is then applied to find an optimal allocation of task modules in a distributed system. The timing aspects embedded in the objective function drive the MAA not only to assign task modules to PNs, but also to use a module scheduling algorithm (MSA) (with polynomial time complexity) for scheduling all modules assigned to each PN so that all tasks may be completed in time. Several numerical examples are presented to demonstrate the effectiveness and practicality of the proposed algorithms. © 1992 IEEE.

关键词： Scheduling algorithms

来源：评论

学校读者我要写书评

暂无评论

Modeling resource contention among distributed periodic processes 4

Modeling resource contention among distributed periodic proc...

引用

4th IEEE Symposium on Parallel and Distributed Processing, SPDP 1992

作者： Welch, Lonnie R. Stoyenko, Alexander D. Marlowe, Thomas J. Real-Time Computing Laboratory Department of Computer and Information Science New Jersey Institute of Technology NewarkNJ07102 United States

ISBN: (纸本)0818632003

Modern real-time systems consist of distributed periodic processes that have critical timing constraints and share replicated resources. A mathematical model of the resource requirements of periodic processes that are specified using RT-Chari [9] is described. We provide novel techniques for computing "rates of progress" for clients of resources and show how to use the rates to predict the execution times of processes. © 1992 IEEE.

关键词： real time 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：