In response to a paper by J. H. Fetzer (Commun. ACM, vol. 31, pp. 1048-1063, 1988) and the subseuqent decision, a clarification is given of what is meant by program verification and what are its benefits and limitatio...
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ISBN:
(纸本)0818620412
In response to a paper by J. H. Fetzer (Commun. ACM, vol. 31, pp. 1048-1063, 1988) and the subseuqent decision, a clarification is given of what is meant by program verification and what are its benefits and limitations. An explanation is presented as to why formal verification can only, at best, guarantee the correct operation of an algorithm. For real systems (e.g., a program running on a real machine) all one can aim for is to achieve a high degree of confidence that the design is correct. This is done by applying validation techniques (e.g. testing, debugging, simulation, formal verification, etc.), fault-tolerant techniques, and good design methods. A comparison is made of the methods of science with the methods used in software design with regard to verification.
A method for introducing data persistence in modular languages is presented;the method is based on an extension of the module concept that performs in the framework of an object-oriented paradigm. Application of the m...
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ISBN:
(纸本)0818620412
A method for introducing data persistence in modular languages is presented;the method is based on an extension of the module concept that performs in the framework of an object-oriented paradigm. Application of the method to Modula-2, a language that supports modularity and encapsulation, is described. The method, however, is more general, being a simple and powerful approach to introducing data persistence which can be applied to existing languages or considered in the design of new ones.
A comparison by practical evaluation of several general-purpose distributed simulation algorithms that use different ways of bringing parallelism to the simulation of computer networks is presented. A description is g...
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ISBN:
(纸本)0818620412
A comparison by practical evaluation of several general-purpose distributed simulation algorithms that use different ways of bringing parallelism to the simulation of computer networks is presented. A description is given of the characteristics of computer networks relevant to distributed simulation, an approach to their modeling, and the characteristics of the parallel computer architecture used. The authors' simulation goals and how these influence the simulator are described. The results and conclusions of the comparison of different strategies for parallelization are also given.
The authors introduce OBJECTEXT, an object-oriented data model for hypertext systems, featuring an extensible set of typed, structured nodes. It is argued that the integration of object-oriented principles can give hy...
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ISBN:
(纸本)081862065X
The authors introduce OBJECTEXT, an object-oriented data model for hypertext systems, featuring an extensible set of typed, structured nodes. It is argued that the integration of object-oriented principles can give hypertexts a clearer, more formal framework and reduce the problem of user disorientation without sacrificing generality or flexibility. It is also argued that hypertexts are a special case of semantic models in general, and of the object-oriented paradigm in particular. An implementation of the system, developed in Prolog, is discussed.
Aspects of methodology in correction with large DP projects are discussed. It is pointed out that methodology is a mapping of the stages of a project and/or the deliverables produced by each of those stages against ti...
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ISBN:
(纸本)081862065X
Aspects of methodology in correction with large DP projects are discussed. It is pointed out that methodology is a mapping of the stages of a project and/or the deliverables produced by each of those stages against time or against state of completeness. It is further noted that individual resistance to methodology on technical grounds is a positive force, and on psycho-social grounds is a natural reaction to a change in the work context. The introduction of methodology into large DP projects should be defined as a prototyping effort.
The testing of real-time systems within the framework of the distributed real-time system MARS (MAintainable Real-time System) is considered. After a brief survey of the available literature and an overview of the bac...
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ISBN:
(纸本)0818620412
The testing of real-time systems within the framework of the distributed real-time system MARS (MAintainable Real-time System) is considered. After a brief survey of the available literature and an overview of the background of this work, a proposed test strategy for MARS is described, and two architectures for testbeds that allow actual test execution in two different test modes are derived. The specification, development, and implementation on one specific test tool, the environmental simulator, is then considered and its use in the proposed test strategy is discussed. The principles described are currently being applied to the construction of an experimental application for MARS.
Space systems are characterized by a low-intensity process noise resulting from uncertain forces and moments. In many cases, their scalar measurement channels can be assumed to be independent, with one-dimensional int...
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Space systems are characterized by a low-intensity process noise resulting from uncertain forces and moments. In many cases, their scalar measurement channels can be assumed to be independent, with one-dimensional internal dynamics. The nominal operation of these systems can be severely damaged by faults in the sensors. A natural method that can be used to yield fault tolerant estimates of such systems is the interacting multiple model (IMM) filtering algorithm, which is known to provide very accurate results. However, having been derived for a general class of systems with switching parameters, the IMM filter does not utilize the independence of the measurement errors in different channels, nor does it exploit the fact that the process noise is of low intensity. Thus, the implementation of the IMM in this case is computationally expensive. A new estimation technique is proposed herein, that explicitly utilizes the aforementioned properties. In the resulting estimation scheme separate measurement channels are handled separately, thus reducing the computational complexity. It is shown that, whereas the IMM complexity is exponential in the number of fault-prone measurements, the complexity of the proposed technique is polynomial. A simulation study involving spacecraft attitude estimation is carried out. This study shows that the proposed technique closely approximates the full-blown IMM algorithm, while requiring only a modest fraction of the computational cost.
this article describes the approach that was used for building service processor of Multiprocessor computersystems (MPCS) Elbrus-1 and Elbrus-2. This service processor has gotten the name Universal engineering Consol...
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ISBN:
(纸本)9781538647417
this article describes the approach that was used for building service processor of Multiprocessor computersystems (MPCS) Elbrus-1 and Elbrus-2. This service processor has gotten the name Universal engineering Console (UEC). In addition, the article describes the hardware structure of UEC and different softwaresystems. All those systems have been designed for off-line setting-up and repair of MPCS components: central processor units, input-output processors, data transfer processors, and technical status controlling device. Also described are structure and general features of UEC special real-time operating system that was intended for setting-up and repair processes of MPCS hardware devices automation, UEC simulation system that was used to build system prototype is also briefly described.
Although Smart-Phones are becoming major in computersystems nowadays, and as multimedia is the most important applications running on the mobile platforms, there is no clear branch for smart phone software engineerin...
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ISBN:
(纸本)9781479938247
Although Smart-Phones are becoming major in computersystems nowadays, and as multimedia is the most important applications running on the mobile platforms, there is no clear branch for smart phone softwareengineering. In this paper, we make a survey on the latest and most well-known frameworks on mobile multimedia softwareengineering. Categorizing the mobile application frameworks is also a main issue that will be discussed. The concentration will be on the cross-platform environments (tools) as the most important applications resulted from the market statistics.
Nowadays, there is a growing need for Management systems to manage various autonomous systems. These Management systems are difficult to test, since their functionality includes exchange of information with various de...
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ISBN:
(纸本)0769520472
Nowadays, there is a growing need for Management systems to manage various autonomous systems. These Management systems are difficult to test, since their functionality includes exchange of information with various devices and applications via the network communication. There is a need for efficient methods of development and testing to minimize development time and cost. The solution suggested in this paper is an Offline Simulation Model, where the simulation and the tested Management System are placed on the same computer. This model decouples the testing of the functional aspects of the developed Management System from the testing of the communication aspects. This method saves a great deal of human effort, and therefore reduces development time and cost.
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