Many languages for computer systems simulation (like GPSS and CSim) use a stochastic model of systems with the provision of adding procedural code for those aspects of the system that cannot be captured easily by a st...
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Many languages for computer systems simulation (like GPSS and CSim) use a stochastic model of systems with the provision of adding procedural code for those aspects of the system that cannot be captured easily by a stochastic model. However, they do not support the hierachical simulation of complex systems well. Complex computer systems may have to be simulated at various levels of abstraction in the interests of tractability: the flexibility of being able to freely move between the different levels of abstraction is very desirable. For example, in the area of computer architecture, one might have analytical models, detailed simulation models and trace-driven models. In addition, these languages do not have user-friendly interfaces for specification of the simulated system. In this paper, we discuss the design and implementation of a simulation package for hierachical simulation of non-real-time computer systems: a Simulator Generator from a Graphical System Specification (SIGGSYS). A new language for system specification has been designed. In addition, the package has the following components: A graphical user interface to aid specification of the system to be simulated. A rear end that generates C++ code that implements a simulator for the specified system. A complete object library along with the header files that implement a functionally complete set of C++ base classes which can be built upon. C++ has been chosen as the intermediate language so that the modeller can use its support for objectorientedprogramming. (C) 1997 John Wiley & Sons, Ltd.
As a part of a substation-level decision support system, a new intelligent Hierarchical Fault Diagnosis System for on-line fault diagnosis is presented in this paper. The proposed diagnosis system divides the fault di...
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As a part of a substation-level decision support system, a new intelligent Hierarchical Fault Diagnosis System for on-line fault diagnosis is presented in this paper. The proposed diagnosis system divides the fault diagnosis process into two phases. Using time-stamped information of relays and breakers, phase I identifies the possible fault sections through the Group Method of Data Handling (GMDH) networks, and phase II recognizes the types and detailed situations of the faults identified in phase I by using a fast bit-operation logical inference mechanism. The diagnosis system has been practically verified by testing on a typical Taiwan power secondary transmission system. Test results show that rapid and accurate diagnosis can be obtained with flexibility and portability for fault diagnosis purpose of diverse substations.
This paper describes the incorporation of seven stand-alone clustering programs into S-PLUS, where they can now be used in a much more flexible way. The original Fortran programs carried out new cluster analysis algor...
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This paper describes the incorporation of seven stand-alone clustering programs into S-PLUS, where they can now be used in a much more flexible way. The original Fortran programs carried out new cluster analysis algorithms introduced in the book of Kaufman and Rousseeuw (1990). These clustering methods were designed to be robust and to accept dissimilarity data as well as objects-by-variables data. Moreover, they each provide a graphical display and a quality index reflecting the strength of the clustering. The powerful graphics of S-PLUS made it possible to improve these graphical representations considerably. The integration of the clustering algorithms was performed according to the object-oriented principle supported by S-PLUS. The new functions have a uniform interface, and are compatible with existing S-PLUS functions. We will describe the basic idea and the use of each clustering method, together with its graphical features. Each function is briefly illustrated with an example. (C) 1997 Elsevier Science B.V.
A scalable processor architecture for multi-threaded Java(TM) application is presented . The proposed architecture consists of multiple application-specific processing elements , each able to execute a single thread a...
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A scalable processor architecture for multi-threaded Java(TM) application is presented . The proposed architecture consists of multiple application-specific processing elements , each able to execute a single thread at one time. The architecture is evaluated by implementing a portable and scalable Java machine on an FPGA board for demonstration.
As modern programming methodologies migrate from computer science to scientific computing, developers of numerical software are faced with new possibilities and challenges. Based on experiences from an ongoing project...
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As modern programming methodologies migrate from computer science to scientific computing, developers of numerical software are faced with new possibilities and challenges. Based on experiences from an ongoing project that develops C++ software for the solution of partial differential equations, this article has its focus on object-oriented design of iterative solvers for linear systems of equations. Special attention is paid to possible conflicts that have to be resolved in order to achieve a very flexible, yet efficient, code.
The Parallel Virtual Machine (PVM) is a software system that enables a collection of heterogeneous computer systems to be used as a coherent and flexible concurrent computation resource. We show that genetic algorithm...
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The Parallel Virtual Machine (PVM) is a software system that enables a collection of heterogeneous computer systems to be used as a coherent and flexible concurrent computation resource. We show that genetic algorithms can be implemented using a Parallel Virtual Machine and C++. Problems with constraints are also discussed.
In this contribution we describe an object-oriented software architecture for image segmentation, 3-D pose estimation as well as Bayesian object recognition: models are represented by densities, model generation corre...
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In this contribution we describe an object-oriented software architecture for image segmentation, 3-D pose estimation as well as Bayesian object recognition: models are represented by densities, model generation corresponds to parameter estimation tasks, and the identification applies the Bayesian decision rule. We show results of 3-D object recognition experiments based on the observation of 2-D points or lines. (C) 1997 Elsevier Science B.V.
This paper presents a model for automatically parallelizing compiler based on C++ which consists of compile-time and run-time parallelizing *** paper also describes a method for finding both intra-object and inter-obj...
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This paper presents a model for automatically parallelizing compiler based on C++ which consists of compile-time and run-time parallelizing *** paper also describes a method for finding both intra-object and inter-object parallelism. The parallelism detection is completely transparent to users.
Workflow systems are receiving increased attention as they intend to facilitate the operations of enterprises by coordinating and streamlining business activities. The need for automated support and operational models...
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Workflow systems are receiving increased attention as they intend to facilitate the operations of enterprises by coordinating and streamlining business activities. The need for automated support and operational models that allow workflow applications to coordinate units of work across multiple servers-according to business defined rules and routes-is becoming critical for the proper management of such activities. In this paper, we describe a Transaction-oriented Workflow Environment (TOWE) for programming workflow activities. The novelty of our approach resides in the proposed unified abstraction, class libraries, to support workflow activities. The fundamental concept used in the TOWE system is based on the symbiosis of object-oriented programming and interprocess communication concepts. In TOWE, the concurrency abstractions are represented by process objects, active objects acting as processes, which involve asynchronous, location-independent, and application specific process invocations.
Our theoretical framework views programming as search in three problem spaces: rule, instance, and representation. The main objectives of this study are to find out how programmers change representation while working ...
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Our theoretical framework views programming as search in three problem spaces: rule, instance, and representation. The main objectives of this study are to find out how programmers change representation while working in multiple problem spaces, and how representation change increases the difficulty of programming tasks. Our theory of programming indicates that programming is similar to the way scientists discover and test theories. That is, programmers generate hypotheses in the rule space and test these hypotheses in the instance space. Moreover, programmers change their representations in the representation space when rule development becomes too difficult or alternative representations are available. We conducted three empirical studies with different programming tasks: writing a new program, understanding an existing program, and reusing an old program. Our results indicate that considerable cognitive difficulties stem from the need to change representations in these tasks. We conclude by discussing the implications of viewing programming as a scientific discovery for the design of programming environments and training methods.
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