The Fudgets system is a toolkit for developing graphical applications in the lazy functional programming language Haskell. In this paper we develop an operational semantics for a subset of this system, inspired by ide...
ISBN:
(纸本)9781581130249
The Fudgets system is a toolkit for developing graphical applications in the lazy functional programming language Haskell. In this paper we develop an operational semantics for a subset of this system, inspired by ideas from concurrency theory. A semantic theory based on bisimulation is defined and shown to be a congruence. We consider two applications of this theory: firstly, some equational rules useful for reasoning about Fudget programs are verified; secondly, we show how the operational semantics can be used to check the correctness of implementations of the Fudgets system.
We introduce a technique to compute several information estimations for Boolean and multivalued functions. Special features of these estimations for completely and incompletely specified logic functions, including sym...
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We introduce a technique to compute several information estimations for Boolean and multivalued functions. Special features of these estimations for completely and incompletely specified logic functions, including symmetric logic functions are investigated. Finally, we give an algorithm for determining various information measures for logical functions based on decision trees.
In the paper we give a straightforward, highly efficient, scalable implementation of common matrix multiplication operations. The algorithms are much simpler than previously published methods, yield better performance...
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.
Query Refinement is an essential information retrieval tool that interactively recommends new terms related to a particular query. This paper introduces concept recall, an experimental measure of an algorithm's ab...
ISBN:
(纸本)0897918363
Query Refinement is an essential information retrieval tool that interactively recommends new terms related to a particular query. This paper introduces concept recall, an experimental measure of an algorithm's ability to suggest terms humans have judged to be semantically related to an information need. This study uses precision improvement experiments to measure the ability of an algorithm to produce single term query modifications that predict a user's information need as partially encoded by the query. An oracle algorithm produces ideal query modifications, providing a meaningful context for interpreting precision improvement results. This study also introduces RMAP, a fast and practical query refinement algorithm that refines multiple term queries by dynamically combining precomputed suggestions for single term queries. RMAP achieves accuracy comparable to a much slower algorithm, although both RMAP and the slower algorithm lag behind the best possible term suggestions offered by the oracle. We believe RMAP is fast enough to be integrated into present day Internet search engines: RMAP computes 100 term suggestions for a 160,000 document collection in 15 ms on a low-end PC.
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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Solving the eigenvalue problems is of great importance in the dynamic analysis of mechanical systems and structures. The paper presents the computer programs in C++ and their implementation in order to determine the e...
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Solving the eigenvalue problems is of great importance in the dynamic analysis of mechanical systems and structures. The paper presents the computer programs in C++ and their implementation in order to determine the eigenvalues and eigenvector using Hotelling's method combined with the power method. To show the implementation method of the programs there were analyzed mechanical systems with many degrees of freedom for which the module forms of the eigenvectors were represented graphically.
The performance of a distributed system depends upon the efficiency of job distribution among processing nodes, as well as that of its system architecture and operating system. The paper presents an extended C languag...
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ISBN:
(纸本)0818680679
The performance of a distributed system depends upon the efficiency of job distribution among processing nodes, as well as that of its system architecture and operating system. The paper presents an extended C language, ParaC, that supports efficient parallel programming on distributed systems. ParaC is designed to reduce the effort of job distribution on distributed programming environments. Our design includes the description of design goals for the parallel language, the definition of a programming model and the design of ParaC constructs. The paper also addresses the detailed design issues related to translation and finally presents our prototype.
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.
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