Augmented shared workspaces are an instance of augmented reality which move the collaborative work from the desktop to the real workplace, enabling higher interaction level with coworkers and allowing implementation o...
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ISBN:
(纸本)0769513301
Augmented shared workspaces are an instance of augmented reality which move the collaborative work from the desktop to the real workplace, enabling higher interaction level with coworkers and allowing implementation of advanced techniques of human-machine interfaces. In this paper, we advocate the employment of a constraint system as the document model (or program) for the implementation of augmented reality applications. We show that constraint technology is synergistic with augmented reality and collaborative work in many aspects. An architecture model based on agents and constraints is then proposed. Our point of view is supported by the observation of this technology being employed in Computer Graphics and Human-Computer Interaction research and the implementation of typical cases.
constraint logic programming has become a promising new technology for solving complex combinatorial problems. In this paper, we investigate how (constraint) logicprogramming can support the modelling part when solvi...
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constraint logic programming has become a promising new technology for solving complex combinatorial problems. In this paper, we investigate how (constraint) logicprogramming can support the modelling part when solving discrete optimisation problems. First, we show that the basic functionality of algebraic modelling languages can be realised very easily in a pure logicprogramming system like PROLOG and that, even without using constraints, various additional features are available. Then we focus on the constraint-solving facilities offered by constraint logic programming systems. In particular, we explain how the constraint solver of the constraint logic programming language CLP(PB) can be used in modelling 0-1 problems.
This paper presents an original method to generate test sequences. From formal specifications of the system to be tested, an equivalent system of constraints is derived, and then, the domain of each state variable of ...
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ISBN:
(纸本)076951426X;0769514278
This paper presents an original method to generate test sequences. From formal specifications of the system to be tested, an equivalent system of constraints is derived, and then, the domain of each state variable of this system is partitioned into subdomains. Using this partition, limit states are computed with a specific solver that uses constraint logic programming with sets. This specific solver is then used to build test sequences by traversing the constrained reachability graph of the specifications. Finally, the formal specifications is used as an oracle by using them to determine the expected output for a given input. The results of an industrial case-study of the Smart Card GSM 11-11 standard are presented and discussed.
Configuration and diagnosis problem-solvers are commonly championed as successes of applied artificial intelligence techniques. A common problem is that problem-solvers typically encode task-specific representation as...
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Configuration and diagnosis problem-solvers are commonly championed as successes of applied artificial intelligence techniques. A common problem is that problem-solvers typically encode task-specific representation assumptions and simplifications in their domain theories, hindering the reuse of the domain theories between the problem-solvers. While model-based reasoning techniques have been shown to provide an interesting approach to sharing component and device specifications, their respective mechanisations are generally too inefficient. We show how constraint logic programming languages provide a flexible environment in which constraint-based specifications can be effectively shared and efficiently mechanised by exploiting constraint solving and propagation techniques tightly integrated with the backtracking search mechanism of logicprogramming languages. A component specification language is presented and the mappings from the language to the constraint system and strategies for guiding the search are defined for the respective problem-solvers. (C) 1998 Elsevier Science Inc. All rights reserved.
This article introduces AJACS (Another Java constraintprogramming System), a toolkit for Concurrent constraintprogramming implemented in the Java language. It comes as a successor to our previous work in implementin...
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This article introduces AJACS (Another Java constraintprogramming System), a toolkit for Concurrent constraintprogramming implemented in the Java language. It comes as a successor to our previous work in implementing constraintprogramming idioms in Java, GC [5], in that it represents an attempt to deal with some of GC's inadequacies in terms of performance whilst providing a setting which is adequate to express problems in a way that can be easily solved in a parallel execution environment, as provided by a concurrent programming setting. We claim that AJACS provides a very flexible toolkit for use in general applications that may benefit from constraintprogramming techniques. We also claim that AJACS allows for the coding of CSP problems whose solution is amenable to a practically effortless parallelization.
Operational research (OR) and artificial intelligence (AI) models are primary contributors to the area of intelligent decision support systems (IDSS). constraint logic programming (CLP) has been used successfully to s...
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Operational research (OR) and artificial intelligence (AI) models are primary contributors to the area of intelligent decision support systems (IDSS). constraint logic programming (CLP) has been used successfully to substantiate the integration of OR and AI. We present a meta-level modular representation for integrating OR and AI models using CLP in an IDSS framework. The use of this representation is illustrated using a CLP-like meta-language, and the potential usefulness of this language is demonstrated using an example from the dairy industry. International Federation of Operational Research Societies 2001.
This paper describes a number of key modeling issues for the development of tools for solving nonlinear discrete/continuous problems where logic/disjunctive constraints are included in the formulation. A generalized h...
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This paper describes a number of key modeling issues for the development of tools for solving nonlinear discrete/continuous problems where logic/disjunctive constraints are included in the formulation. A generalized hybrid representation of these problems is presented. A comparison between constraint logic programming (CLP) and generalized disjunctive programming (GDP) is established together with several constraint transformations from CLP to GDP. The components and expressions of a modeling language for setting up disjunctions and logicconstraints are proposed. The language allows the specification of problems with complex logic formulations. A parser is developed for the analysis and translation of the logic sentences into files ready to be used by the solvers. An overview of the solution algorithms is also given together with several aspects about the implementation as a superset of GAMS mathematical programming language. Examples illustrating the capabilities of the proposed system are described. (C) 2000 Elsevier Science Ltd. All rights reserved.
This article presents a method for the resolution of a material handling scheduling problem. The case studied is a real industrial problem. It consists of finding a cyclic schedule for hoist movements in a treatment s...
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This article presents a method for the resolution of a material handling scheduling problem. The case studied is a real industrial problem. It consists of finding a cyclic schedule for hoist movements in a treatment surface shop. In this kind of facility, several hoists are used for all the handling operations and they have to share common zones. Then it is necessary to control that there is no collision. The mathematical formulation of the problem is based on a combination of disjunctive constraints. The constraints describe either movement schedule or collision avoidance. The resolution procedure presented identifies all the collision configurations and then uses a branch and bound-like algorithm to find the optimal solution of a given problem. The language chosen for our implementation is the constraint logic programming language: Prolog IV, which is able to solve constraints with rational variables. It actively uses the constraint propagation mechanism that can be found in several languages.
Studying independence of goals has proven very useful in the context of logicprogramming. In particular, it has provided a formal basis for powerful automatic parallelization tools, since independence ensures that tw...
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Studying independence of goals has proven very useful in the context of logicprogramming. In particular, it has provided a formal basis for powerful automatic parallelization tools, since independence ensures that two goals may be evaluated in parallel while preserving correctness and efficiency. We extend the concept of independence to constraintlogic programs (CLP) and prove that it also ensures the correctness and efficiency of the parallel evaluation of independent goals. Independence for CLP languages is more complex than for logicprogramming as search space preservation is necessary but no longer sufficient for ensuring correctness and efficiency Two additional issues arise. The first is that the cost of constraint solving may depend upon the order constraints are encountered. The second is the need to handle dynamic scheduling. We clarify these issues by proposing various types of search independence and constraint solver independence, and show how they can be combined to allow different optimizations, from parallelism to intelligent backtracking. Sufficient conditions for independence which can be evaluated "a priori" at run-time are also proposed. Our study also yields new insights into independence in logicprogramming languages. In particular, we show that search space preservation is not only a sufficient but also a necessary condition for ensuring correctness and efficiency of parallel execution.
Global analyzers traditionally read and analyze the entire program at once, in a nonincremental way. However, there are many situations which are not well suited to this simple model and which instead require reanalys...
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Global analyzers traditionally read and analyze the entire program at once, in a nonincremental way. However, there are many situations which are not well suited to this simple model and which instead require reanalysis of certain parts of a program which has already been analyzed. In these cases, it appears inefficient to perform the analysis of the program again from scratch, as needs to be done with current systems. We describe how the fixed-point algorithms used in current generic analysis engines for (constraint) logicprogramming languages can be extended to support incremental analysis. The possible changes to a program are classified into three types: addition, deletion, and arbitrary change. For each one of these, we provide one or more algorithms for identifying the parts of the analysis that must be recomputed and for performing the actual recomputation. The potential benefits and drawbacks of these algorithms are discussed. Finally, we present some experimental results obtained with an implementation of the algorithms in the PLAI generic abstract interpretation framework. The results show significant benefits when using the proposed incremental analysis algorithms.
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