We describe an ongoing project, to develop a general theory of computation and specification over classes of structures, modelling abstract data types. Applications include logic programming module development and har...
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We work in the context of abstract data types, modelled as classes of many-sorted algebras. We develop notions of computability over such data types, in particular notions of primitive recursiveness and μ-recursivene...
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作者：
Addis, T.R.Knowledge Systems Group
Computer Science Department University of Reading Whiteknights Reading Berkshire RG6 2AX PO Box 220 United Kingdom
Knowledge-based systems provide intellectual assistance through the manipulation of symbols. The theoretical basis for this manipulation is derived from the logic research programme which restricts the creation of mod...
— This paper presents an exploratory approach to the development of a tool for integrating existing databases. The intent is to meet specific requirements and to achieve flexibility through the creation of an “open...
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ISBN:
(纸本)0897913477
— This paper presents an exploratory approach to the development of a tool for integrating existing databases. The intent is to meet specific requirements and to achieve flexibility through the creation of an “open” system. The methodology assumes an integration model which captures the essential characteristics of a distributed system within a knowledge base. The model and the underlying knowledge base may be used to represent the distributed environment and to define requirements for the shared use of heterogeneous databases. An interactive method is proposed which allows the user to proceed in an iterative fashion in specifying system attributes and resolving design conflicts. The project is at present in the definition phase; current work is aimed at the identification of generic multidatabase services, and their abstraction in a form amenable for storage in the knowledge base.
The ISO specification language LOTOS is presented, together with the results of a project involving the evaluation of its usefulness in an industrial environment. LOTOS is a mixture of concepts taken from CCS and CSP,...
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The problem of finding the spatial correspondence between an object and the image of the object under perspective projection is investigated and a new technique is demonstrated. This technique is based on a geometrica...
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The problem of finding the spatial correspondence between an object and the image of the object under perspective projection is investigated and a new technique is demonstrated. This technique is based on a geometrical description, or model, of the object and a least squares solution of the resulting nonlinear equations. An analysis of performance and a comparison with Lowe's previous work is given. Three further areas of applications in model based vision are discussed.
Labelling sets of 2D image features as model features is a constraint satisfaction problem that occurs in model-based vision. The labelling must be consistent with constraints that describe how image features originat...
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Labelling sets of 2D image features as model features is a constraint satisfaction problem that occurs in model-based vision. The labelling must be consistent with constraints that describe how image features originating from the modelled object would appear in the image. This paper discusses how an assumption-based truth maintenance system (ATMS) can be used to solve such a constraint-satisfaction problem. The ATMS is used to limit the number of constraints applied, and to represent the multiple sets of consistent labels that are possible. The effectiveness of the ATMS in limiting the constraints is analysed.
Two methods are proposed to improve the schedules of job-shops determined by using heuristic priority rules. One is to modify the priority of a job, which is the most critical to its duty date, by assuming the shorten...
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Two methods are proposed to improve the schedules of job-shops determined by using heuristic priority rules. One is to modify the priority of a job, which is the most critical to its duty date, by assuming the shortening of the duty date. It is verified that the maximum lateness in due dates is decreased by 34 %. The other method is to modify the operation speeds of jobs so as to maximize the total cost performance of the factory by changing the weight on running cost. It is shown that the cost performance of the total system improved by nearly 62 %.
As optimization of strategies to process queries in a Distributed DataBase (DDB) uses various techniques to estimate the sizes of partial results and other parameters pertaining to the distributed environment, if thes...
ISBN:
(纸本)9780897912990
As optimization of strategies to process queries in a Distributed DataBase (DDB) uses various techniques to estimate the sizes of partial results and other parameters pertaining to the distributed environment, if these estimates are inaccurate the strategies may be far from optimal. Dynamic query execution, which may be used to alleviate this problem, is examined in this paper. Execution of a strategy is assumed to proceed through three phases: (i) monitoring phase in which processors monitor the progress of the strategy execution; (ii) decision making phase in which they may decide to correct the current strategy because it is not optimal due to inaccurate estimates used in its formulation; and (iii) corrective phase in which the current strategy is aborted and a new, corrective strategy is initiated. Methods applicable to each phase and their integration is examined in detail in terms of overhead, complexity and accuracy of information used in correcting a strategy.
This paper describes a modularized AI system being built to help improve electromagnetic compatibility (EMC) among shipboard topside equipment and their associated systems. CLEER is intended to act as an easy to use i...
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This paper describes a modularized AI system being built to help improve electromagnetic compatibility (EMC) among shipboard topside equipment and their associated systems. CLEER is intended to act as an easy to use integrator of existing expert knowledge and pre-existing data bases and large scale analytical models. Due to these interfaces; to the need for portability of the software; and to artificial intelligence related design requirements (such as the need for spatial reasoning, expert data base management, model base management, track-based reasoning, and analogical (similar ship) reasoning) it was realized that traditional expert system shells would be inappropriate, although relatively off-the-shelf AI technology could be incorporated. In the same vein, the rapid prototyping approach to expert system design and knowledge engineering was not pursued in favor of a rigorous systems engineering methodology. The critical design decisions affecting CLEER's development are summarized in this paper along with lessons learned to date all in terms of “how,” “why,” and “when” specific features are being developed.
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