A lack of adequate and flexible topology support in the popular message passing systems such as Parallel Virtual Machine was a major factor in the development of our Virtual Process Topology Environment. This parallel...
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A lack of adequate and flexible topology support in the popular message passing systems such as Parallel Virtual Machine was a major factor in the development of our Virtual Process Topology Environment. This parallel programming environment provides high level abstractions for interprocess communication, relieving the application developer of the cumbersome task of mapping logical neighbours to their task identifiers within message passing systems. The novel approach of separating topological specification from the APIs provided extreme flexibility to the developers of the applications using regular topologies. We believed that the task of supporting process topologies could be made even easier and, in this paper present our new method which uses recurrence relations to define topologies. Within the new environment, the recurrence relationships can be passed to the topology server which then is used in the generation of the topological specification.
In modern circuit design, the Shannon decomposition of switching functions is widely used. On the other hand, in information theory of telecommunication, the Shannon entropy used as a measure to represent the informat...
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In modern circuit design, the Shannon decomposition of switching functions is widely used. On the other hand, in information theory of telecommunication, the Shannon entropy used as a measure to represent the information in numerical values, is a key notion. In this paper, we relate these two concepts, belonging to different areas, into an approach to the minimisation of exclusive-or sum-of-products (AND/EXOR) expressions for switching functions. The Shannon decomposition, and the closely related Davio decomposition for AND/EXOR expressions are interpreted in terms of basic concepts in the information theory. Thanks to that, we have proposed an entropy based strategy for minimization of AND/EXOR expressions. We have provided a comparison and an experimental verification of this strategy with some known heuristic minimization strategies using benchmarks. In some cases, our program Info-EXOR produces extremely better results. Moreover, the information theory interpretation of classical decomposition of switching functions offers a new point of view to the existing design styles.
Whereas it is generally acknowledged that code tangling reduces the quality of software and that aspect-oriented programming (AOP) is a means of addressing this problem, there is — as yet — no clear definition or ch...
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One of the major difficulties in controlling software development project cost overruns and schedule delays has been developing practical and accurate software cost models. Software development could be modeled as an ...
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One of the major difficulties in controlling software development project cost overruns and schedule delays has been developing practical and accurate software cost models. Software development could be modeled as an economic production process and we therefore propose a theoretical approach to software cost modeling. Specifically, we present the Minimum Software Cost Model (MSCM), derived from economic production theory and systems optimization. The MSCM model is compared with other widely used software cost models, such as COCOMO and SLIM, on the basis of goodness of fit and quality of estimation using software project data sets available in the literature. Judged by both criteria, the MSCM model is comparable to, if not better than, the SLIM, and significantly better than the rest of the models. In addition, the MSCM model provides some insights about the behavior of software development processes and environment, which could be used to formulate guidelines for better software project management polic es and practices.
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.
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.
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.
We goal of the work is to derive four-voice music pieces from given musical plans, which describe the harmonic flow and the intentions of a desired composition. We developed the experimentation platform COMPOzE for in...
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We goal of the work is to derive four-voice music pieces from given musical plans, which describe the harmonic flow and the intentions of a desired composition. We developed the experimentation platform COMPOzE for intention based composition. COMPOzE is based on constraint programming over finite domains of integers. We argue that constraint programming provides a suitable technology for this task and that the libraries and tools available for the constraint programming system Oz effectively support the implementation of COMPOzE. This work links the research areas of automatic music composition on one hand and finite domain constraint programming on the other, and contributes the tool COMPOzE, which practically demonstrates the potential of constraint programming to open up new areas of application for automatic music composition.
Results of extensive computational experiments aimed at comparing performance quality (accuracy of an approximate solution and the running time) of the Threshold Accept (TA) approach versus the Simulated Annealing (SA...
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This paper details the use of a circuit-based EM modelling technique combined with a harmonic balance simulator used to model the radiation from the microstrip bodies comprising an active antenna circuit. The modellin...
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This paper details the use of a circuit-based EM modelling technique combined with a harmonic balance simulator used to model the radiation from the microstrip bodies comprising an active antenna circuit. The modelling approach adopted for the planar bodies in the circuit will be shown to allow the use of concurrent algorithms in order to reduce overall computational time.
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