Three different methods for automated geometry theorem proving-a generalized version of Dixon resultants, Gröbner bases and characteristic sets--axe reviewed. The main focus is, however, on the use of the general...
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We develop a general constraint logic programming (CLP) based framework for specification and verification of real time systems. Our framework is based on the notion of timed automata that have traditionally been used...
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We develop a general constraint logic programming (CLP) based framework for specification and verification of real time systems. Our framework is based on the notion of timed automata that have traditionally been used for specifying real time systems. In our framework, a user models the ordering of real time events as the grammar of a language accepted by a timed automata, the real time constraints on these events are then captured as denotations of the grammar productions specified by the user. The grammar can be specified as a Definite Clause Grammar (DCG), while the denotations can be specified in constraint logic. The resulting specification can hence be regarded as a constraint logic program (CLP), and is executable. Many interesting properties of the real time system can be verified by posing appropriate queries to this CLP program. A major advantage of our approach is that it is constructive in nature, i.e., it can be used for computing the conditions under which a property will hold for a given real time system. Our framework also suggests new types of formalisms that we call constraint automata and timed push down automata.
作者：
Chris McDonaldKamran KazemiProgramming
Languages and Systems Group Department of Computer Science The University of Western Australia Crawley Western Australia 6907
The parallel programming community has long recognized the need for a simple programming environment offering interprocess communication between heterogeneous systems. As the Parallel Virtual Machine environment, PVM,...
ISBN:
(纸本)9780897918893
The parallel programming community has long recognized the need for a simple programming environment offering interprocess communication between heterogeneous systems. As the Parallel Virtual Machine environment, PVM, has emerged to meet this goal, an increasing number of educational institutions are choosing PVM to support their teaching of parallel and distributed computing using networks of workstations. However, it is often the nature of PVM's design and implementation that can severely limit its success in a teaching environment. This paper first motivates and then describes improvements to the PVM environment which increase both robustness and efficiency in an educational setting.
This paper demonstrates how the demultiplexor is used for making a new tree embedded in a MIN and how the Augmented Generalized Cube Network is designed using this tree. Evaluation of its performance and examination o...
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ISBN:
(纸本)0818682272
This paper demonstrates how the demultiplexor is used for making a new tree embedded in a MIN and how the Augmented Generalized Cube Network is designed using this tree. Evaluation of its performance and examination of its characteristics are also included. The demultiplexor was originally used for providing tolerance for destination link failures. The above shows that the AGCN gets better performance than other MINs. Not only does the AGCN have all of the Generalized Cube Network's features but it also offers multiple paths using a new embedded tree and intrastage links. Its self-adaptive routing in the last stage can alleviate tree saturation and contribute greatly to performance improvement.
Fail-safety is a system attribute which ensures that a program either completes its execution satisfying its post-conditions in the normal manner or signals its failure to do so to its operating environment. Such an a...
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Fail-safety is a system attribute which ensures that a program either completes its execution satisfying its post-conditions in the normal manner or signals its failure to do so to its operating environment. Such an attribute is desirable of any system as it ensures the correctness of results which are produced. A very few modern sequential programming languages offer program fail-safety through the judicious use of a well designed exception handling mechanism. In this paper the exception handling techniques used in those sequential systems are developed to provide the guidelines for fail-safe concurrent system design. (C) 1997 Elsevier science Ltd.
We show that elementary ACI10 unification is in P, even with constant restrictions. As a corollary, we prove that validity of quantified Horn formulae can be tested in O(n2) time. Solvability of elementary disunificat...
We show that elementary ACI10 unification is in P, even with constant restrictions. As a corollary, we prove that validity of quantified Horn formulae can be tested in O(n2) time. Solvability of elementary disunification problems modulo ACI10 is shown to be NP-hard.
Renovation of business-critical software is becoming increasingly important. We identify fundamental notions and techniques to aid in system renovation and sketch some basic techniques: generic language technology to ...
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The paper describes MICE, a prototype implementation of MPI on the Converse interoperable parallel programming environment. It is based on MPICH, a public-domain implementation of MPI and uses the Abstract Device Inte...
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The paper describes MICE, a prototype implementation of MPI on the Converse interoperable parallel programming environment. It is based on MPICH, a public-domain implementation of MPI and uses the Abstract Device Interface (ADI) which has been retargeted on top of Converse. MICE makes use of message-managers and allows use of thread-objects to let MPI modules co-exist with other types of computations and communication (such as a library computation in Charm++ or asynchronous computations in multipol) within a single application. It also makes it possible to interoperate PVM (in a restricted form) and MPI modules. Thread-objects make it possible to build multi-threaded MPI programs. This MPI implementation demonstrates that it is possible to provide interoperability without any significant performance degradation.
作者：
Chris McDonaldProgramming
Languages and Systems Group Department of Computer Science The University of Western Australia Crawley Western Australia
One of the greatest benefits provided by computer networks, in particular local area networks, is the ability to access files served by other computers in a network. Whereas file system concepts are first introduced i...
ISBN:
(纸本)9780897917575
One of the greatest benefits provided by computer networks, in particular local area networks, is the ability to access files served by other computers in a network. Whereas file system concepts are first introduced in Operating Systems units, many file system concepts need to be readdressed and generalized in later computer Networks units. Moreover, as students become increasingly familiar with internetworking and programs such as ftp, many of the strong links between the Operating Systems and computer Networks units may be reinforced. This paper discusses the successes experienced with two strongly related projects offered in our third year computer Networks unit. Each project requires students to support a minimal distributed file system by implementing user-level libraries which redefine a handful of operating system system calls supporting remote file access.
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