检索结果-内蒙古大学图书馆

Non-clausal deductive techniques for computing prime implicants and prime implicates 4th

4th International Conference on Logic programming and Automated Reasoning, LPAR 1993

作者： Ramesh, Anavai Murray, Neil V. Inst. for Programming and Logics Dept. of Computer Science State Univ. of N.Y. at Albany AlbanyNY12222 United States

ISBN: (纸本)9783540569442

Several methods to compute the prime implicants and the prime implicates of a negation normal form (NNF) formula are developed and implemented. An algorithm PI is introduced that is an extension to negation normal form of an algorithm given by Jackson and Pais. The PI algorithm alone is sufficient in a computational sense. However, it can be combined with path dissolution, and it is shown empirically that this is often an advantage. None of these variations rely on conjunctive normal form or on disjunctive normal form. A class of formulas is described for which reliance on CNF or on DNF results in an exponential increase in the time required to compute prime implicants/implicates. The possibility of avoiding this problem with efficient structure preserving clause form translations is examined briefly and appears unfavorable. © Springer-Verlag Berlin Heidelberg 1993.

关键词： computer circuits

来源：评论

学校读者我要写书评

暂无评论

Real-time refinement: Semantics and application 18th

引用

18th International Symposium on Mathematical Foundations of computer Science, MFCS 1993

作者： Scholefield, David Zedan, Hussein Jifeng, He Formal Systems Research Group Department of Computer Science University of York Heslington York United Kingdom Programming Research Group Oxford University Keble Road Oxford United Kingdom

ISBN: (纸本)9783540571827

A formal framework for a calculus of real-time systems is presented. Specifications and program statements are combined into a single language called TAM (the Temporal Agent Model), that allows the user to express both functional and timing properties. A specification oriented semantics for TAM is given, along with the definition of a refinement relation and a calculus which is sound with respect to that relation. A simple real-time program is also developed using the calculus. © 1993, Springer Verlag. All rights reserved.

关键词： Semantics

来源：评论

学校读者我要写书评

暂无评论

Real space process algebra

引用

Formal Aspects of Computing 1993年第6期5卷 481-529页

作者： Baeten, J.C.M. Bergstra, J.A. Department of Computer Science Eindhoven University of Technology MB Eindhoven 5600 P.O. Box 513 Netherlands Programming Research Group University of Amsterdam Amsterdam Netherlands Department of Philosophy Utrecht University Utrecht Netherlands

The real time process algebra of Baeten and Bergstra [Formal Aspects of Computing, 3, 142-188 (1991)] is extended to real space by requiring the presence of spatial coordinates for each atomic action, in addition to the required temporal attribute. It is found that asynchronous communication cannot easily be avoided. Based on the state operators of Baeten and Bergstra [Information and Computation, 78, 205-245 (1988)] and following Bergstra et al. [Proc. Seminar on Concurrency, LNCS 197, Springer, 1985, pp. 76-95], asychronous communication mechanisms are introduced as an additional feature of real space process algebra. The overall emphasis is on the introductory explanation of the features of real space process algebra, and characteristic examples are given for each of these. © 1993 BCS.

关键词： Asynchronous communication Broadcasting Priorities Process algebra Real space process algebra Real time process algebra State operator

来源：评论

学校读者我要写书评

暂无评论

CHIP in plain logic

CHIP in plain logic

引用

IEEE Pacific Rim Conference on Communications, computers and Signal Processing

作者： M.R. Levy M.H. van Emden Logic Programming Laboratory Department of Computer Science University of Victoria Victoria BC Canada

The programming language Prolog allows succinct representation of a wide variety of scheduling problems. To speed up execution, a new version called CHIP (Constraint Handling In Prolog) was introduced that maintains the programming advantages of Prolog. CHIP achieves its speed by keeping track of the sets of possible values for each variable. In this way, a search can be abandoned as soon as any such set becomes empty. This mechanism is made part of the unification algorithm. CHIP maintains the conventional orientation of logic towards single values. Thus, an awkward theoretical structure results from interfacing with set orientation in unification. This problem is solved by using a set-orientation for the entire logic.< >

关键词： Logic programming computer languages Job shop scheduling Laboratories computer science Processor scheduling Assembly Hospitals Educational institutions

来源：评论

学校读者我要写书评

暂无评论

The industrial take-up of formal methods in safety-critical and other areas: A perspective 1st

The industrial take-up of formal methods in safety-critical ...

引用

1st International Symposium of Formal Methods Europe, FME 1993

作者： Bowen, Jonathan Stavridou, Victoria Oxford University Computing Laboratory Programming Research Group 11 Keble Road OxfordOX1 3QD United Kingdom Department of Computer Science Royal ttolloway University of London Egham SurreyTW20 0EX United Kingdom

ISBN: (纸本)9783540566625

Formal methods may be at the crossroads of acceptance by a wider industrial community. In order for the techniques to become widely used, the gap between theorists and practitioners must be bridged effectively. In particular, safety-critical systems offer an application area where formal methods may be engaged usefully to the benefit of all. This paper discusses some of the issues concerned with the general acceptance of formal methods and concludes with a summary of the current position and how the formal methods community could proceed to improve matters in the future. © 1993, Springer Verlag. All rights reserved.

关键词： Formal methods

来源：评论

学校读者我要写书评

暂无评论

Towards automatic evaluation of drawing analysis performance-A statistical model of cadastral map

Towards automatic evaluation of drawing analysis performance...

引用

International Conference on Document Analysis and Recognition

作者： D. Madej A. Sokolowski Department of Computer Technology and Programming Bilkent University Ankara Turkey IFTR Polish Academy of Sciences Poland Academy of Economics krakow Poland and Department of Economics Bilkent University Ankara Turkey

Automatic evaluation of drawing-to-CAD conversion performance is addressed. The generating model of artificial images in the domain of cadastral maps was built. The proposed model was close to the authentic drawings on the level of graphic primitives and on the level of map understanding. The shape of the parcel was characterized by the number of corners, line lengths and respective angles. The model of a house consists of 12 random variables, while the 13th variable describes the location of the house in a parcel. The parameters of probability distributions have been estimated from the sample of 115 parcels and 127 houses. The goodness-of-fit for all distributions was very high.< >

关键词： Performance analysis Performance evaluation Image converters Shape Image generation Automatic testing Paper technology Automatic programming Graphics Random variables

来源：评论

学校读者我要写书评

暂无评论

PERFORMANCE TESTING OF SHIPBOARD ELECTRONIC SYSTEMS

引用

NAVAL ENGINEERS JOURNAL 1993年第3期105卷 118-124页

作者： HARDER, G MARTIN, RA PE George Harder:is an electronics engineer for Naval Undersea Warfare Center Detachment Norfolk's Electromagnetic Engineering Branch located at the Norfolk Shipboard Electronic Systems Evaluation Facility (SESEF) site. He is responsible for fleet electromagnetic readiness (FEMR) inspections on board Navy ships and provides computer programming support to SESEF. Mr. Harder has a bachelor of science degree in electrical engineering from the University of Florida and has qualified for his professional engineering license in the state of Virginia. Robert A. Martin:is a supervisor electronics engineer employed by the Naval Undersea Warfare Center Detachment Norfolk. He functions as the branch head for the Electromagnetic Engineering Office which is responsible for the operation of the Norfolk Shipboard Electronic Systems Evaluation Facility (SESEF) and the Fleet Electromagnetic Readiness (FEMR) Program. Mr. Martin received a bachelor of science degree in electrical engineering from the University of Akron.

Performance evaluation of shipboard electronic systems entails debugging the systems in a laboratory environment, placing them in service and relving on svstem operators to provide feedback. General testing can be performed at selected sites by system designers, but each site where equipment is to be installed can offer unique problems. It is impossible to predict all the scenarios. Unique problems are more the rule than the exception when equipment is destined for Navy ships. Ship deployments make for difficult logistics when sending test teams to evaluate system failures. So, out of necessity, if newly installed equipment receives the proper inputs and generates the proper outputs, it is accepted and becomes the sailor's responsibilitv to maintain. In cases where documentation is ambiguous or incomplete, it is left to the sailor's ingenuity to continue testing and training on equipment. This is generallv obtained through computer simulations and back-to-back testing which can provide results for ideal conditions, but does not take the dynamics of interference into account. Remote site testing is the only way to get a true representation of equipment performance and training problems. Electronic system operators on board Navy vessels are fortunate, thev have help. There exists an organization available near major naval ports worldwide whose existence is to test electronic systems performance. The testing utilizes electronic systems as they would normally be configured for operations. This organization is the Shipboard Electronic Svstem Evaluation Facility (SESEF).

关键词：

来源：评论

学校读者我要写书评

暂无评论

CONCURRENT BOUNDARY-ELEMENT COMPUTATION

引用

INTERNATIONAL JOURNAL OF NUMERICAL MODELLING-ELECTRONIC NETWORKS DEVICES AND FIELDS 1993年第2期6卷 83-98页

作者： MCDOWALL, DS LEE, TW FUSCO, VF Microwave Research Group Department of Electrical and Electronic Engineering The Queen's University of Belfast Ashby Building Stranmillis Road Belfast BT9 5AH Northern Ireland U.K. D. Stewart McDowall was born in Dublin epublic of Ireland in 1967. He received the M. Eng. degree in Electrical and Electronic Engineering from the Queen's University of Belfast in 1990. In the same year he was presented with a Distinction Award from the Department of Education of Northern Ireland and he is currently pursuing his Ph.D. in the Microwave Research Group at Q.U.B. His principal research area is the electromagnetic field mapping of microwave systems using concurrient programming. He is an Associate Member of the Institute of Electrical Engineers. Lee Thaim Wee was awarded the degree of B. Eng. in Electronics from the Queen's University of Belfast in July 1991. He is currently serving in the Malaysian Armed Forces. Vincent F. Fusco was educated at the Queen's Univeristy of Belfast where he obtained the degree of Ph.D. in 1982. He has worked as a research engineer on short-range radar and radio telementry systems. Currently he is a reader in Microwave Communications in the School of Electrical Engineering and Computer Science the Queen's Univeristy of Belfast. His current research interests include non-linear microwave circuit simulation and concurrent programming techniques for electromagnetic field problems with particular emphasis on EMC applications. He has published numerous research papers in these areas. He is the author of the bookMicrowave Circuits Analysis and Computer Aided Design Prentice-Hall 1987. Dr Fusco is a Chartered Electrical Engineer and a Member of the Institute of Electrical Engineers.

A major limitation of the boundary element method (BEM) for the solution of electrical potential problems is the long computational time required. However, a large portion of the calculations involved can be viewed as being parallel in nature and can therefore be computed concurrently. This paper makes an effort to increase the efficiency of the BEM process using transputer-based multiprocessor computing techniques. The algorithms developed may equally well be applied to any multiprocessor system. The application selected to demonstrate the technique is the solution of an electrostatic problem governed by a two-dimensional Laplace equation. A parallel algorithm for problem setup and field extraction using BEM is designed and implemented on a transputer array. Special attention is directed to the utilization of the parallel processors to achieve maximum efficiency. The analysis in this work concentrates on the communication strategies for passing data between processors as well as a consideration of the workload attributed to each processor. The parallel algorithms were implemented using 3L Parallel Fortran;however, the choice of topology for the overall BEM implementation was limited by the fact that certain parts of the algorithm could only utilize a pipeline configuration of processors. Comprehensive results for the parallel BEM algorithm are given and they are encouraging, indicating that parallel processing has much to offer when applied to the boundary element method.

关键词： Boundary element method

来源：评论

学校读者我要写书评

暂无评论

TLM MODELING USING AN SIMD computer

引用

INTERNATIONAL JOURNAL OF NUMERICAL MODELLING-ELECTRONIC NETWORKS DEVICES AND FIELDS 1993年第4期6卷 299-304页

作者： TAN, CC FUSCO, VF The Queen's University of Belfast Department of Electrical & Electronic Engineering Ashby Building Stranmillis Road Belfast BT9 5AH U.K. Chun Chia Tan obtained a first-class honours degree from The Queen's University of Belfast. He was awarded an IEE prize for best final-year project. His current research interests include the modelling of electromagnetic fields using parallel processing techniques. At present Mr Tan is working as an electrical engineer in Malaysia. Vincent F. Fusco was educated at The Queen's University of Belfast where he obtained the degree of Ph.D. He has worked as a research engineer on short-range radar and radio telementry systems. Currently he is a Reader in Microwave Commnications in the School of Electrical Engineering and Computer Science The Queen's Univeristy of Belfast. His current research interests include non-linear microwave circuit simulation and concurrent programming techniques for electromagnetic field problems. He has acted as consultant to a number of major companies and has published numerous research papers in these areas. He is author of the bookMicrowave Circuits Analysis and Computer Aided Design(Prentice Hall 1987). Dr Fusco is a Chartered Electrical Engineer and a Member of the Institute of Electrical Engineers.

A major limitation of the transmission-line matrix (TLM) method used to solve Maxwell's equations is the long computation time required. The TLM scattering calculations involved can, however, be viewed as parallel in nature. This paper describes an effort to reduce computational time by using an SIMD, DAP multiprocessor computer employed to solve a two-dimensional TLM electromagnetic field formulation. A parallel algorithm based on the TLM scattering algorithm is designed and implemented using FORTRAN-PLUS Enhanced on an AMT DAP 510 machine. Here the connectivity of the DAP is exploited to simulate the intrinsic scattering behaviour on which the TLM algorithm relies. The results show that parallel processing on an SIMD machine such as the DAP is advantageous, especially for higher-order mesh sizes.

关键词： Electric lines

来源：评论

学校读者我要写书评

暂无评论

On the Complexities of Non-Horn Clause Logic programming

引用

Journal of computer Science & Technology 1992年第2期7卷 114-122页

作者：聂旭民 Institute for Programming and Logics Department of computer science State University of New York at AlbanyAlbanyNew York 12222U.S.A.

There have been active work to extend the Prolog style Horn Clause logic programming to non-Horn *** this paper,we will analyze the complexities of several such *** purpose is to understand the computational complexity of these inference *** analyses do not prove that any one system is better than the others all the *** they do suggest that one system may be better than the others for some particular *** also discuss the effect of caching.

关键词： Prolog On the Complexities of Non-Horn Clause Logic programming

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：