Taylor introduced a variable binding scheme for logic variables in his PARMA system, that uses cycles of bindings rather than the linear chains of bindings used in the standard WAM representation. Both the HAL and dPr...
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Taylor introduced a variable binding scheme for logic variables in his PARMA system, that uses cycles of bindings rather than the linear chains of bindings used in the standard WAM representation. Both the HAL and dProlog languages make use of the PARMA representation in their Herbrand constraint solvers. Unfortunately, PARMA's trailing scheme is considerably more expensive in both time and space consumption. The aim of this paper is to present several techniques that lower the cost. First, we introduce a trailing analysis for HAL using the classic PARMA trailing scheme that detects and eliminates unnecessary trailings. The analysis, whose accuracy comes from HAL's determinism and mode declarations, has been integrated in the HAL compiler and is shown to produce space improvements as well as speed improvements. Second, we explain how to modify the classic PARMA trailing scheme to halve its trailing cost. This technique is illustrated and evaluated both in the context of dProlog and HAL. Finally, we explain the modifications needed by the trailing analysis in order to be combined with our modified PARMA trailing scheme. Empirical evidence shows that the combination is more effective than any of the techniques when used in isolation.
Personal identification number (PIN) blocks are 64-bit strings that encode a PIN ready for encryption and secure transmission in banking networks. These networks employ tamper-proof hardware security modules (HSMs) to...
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Personal identification number (PIN) blocks are 64-bit strings that encode a PIN ready for encryption and secure transmission in banking networks. These networks employ tamper-proof hardware security modules (HSMs) to perform sensitive cryptographic operations. such as checking the correctness of a PIN typed by a customer. The use of these HSMs is controlled by an API designed to enforce security. PIN block attacks are unanticipated sequences of API commands which allow an attacker to determine the value of a PIN in an encrypted PIN block. This paper describes a framework for formal analysis of such attacks. Our analysis is probabilistic, and is automated using constraint logic programming and probabilistic model checking. (c) 2006 Elsevier B.V. All rights reserved.
The paper focuses on a selected class of decision problems related with the production flow planning in SMEs, particularly in new production orders. Verification of orders gives a possibility to evaluate whether resou...
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ISBN:
(纸本)9780780397583
The paper focuses on a selected class of decision problems related with the production flow planning in SMEs, particularly in new production orders. Verification of orders gives a possibility to evaluate whether resources capacity of a manufacturer is balanced with the orderer's requirements. The class of decision problems under analysis is included in the scope of organizational production preparation and can be naturally determined by available CLP (constraint logic programming) tools. The approach proposed in the paper is based on establishment of an interface which facilitates its task oriented use. The system has been presented on the basis of a sample order, execution in a manufacturer's company (Archimedes S.A.).
In this paper, we present a conception methodology based on system requirements, whithin which we propose to integrate formalisation and verification into the same process. This method uses the constraintprogramming ...
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ISBN:
(纸本)9787302139225
In this paper, we present a conception methodology based on system requirements, whithin which we propose to integrate formalisation and verification into the same process. This method uses the constraintprogramming paradigm to synthesize Petri nets corresponding to a formal expression of requirements as constraints over the PN structure. Some additional techniques are provided to incrementaly refine the synthesized net until it satisfies the whole requirements. http://***/stamp/***?tp=&arnumber=4281812
While constraint logic programming (CLP) is becoming a favorite tool for decision support systems (DSS), its utility to DSS is limited due to the lack of decision theoretic analysis capability. The combination of CLP ...
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While constraint logic programming (CLP) is becoming a favorite tool for decision support systems (DSS), its utility to DSS is limited due to the lack of decision theoretic analysis capability. The combination of CLP with decision theoretic analysis is therefore necessary for more fruitful CLP applications to DSS. In this paper, we propose a framework which embeds decision tree analysis into CLP. The framework provides an integrated representation of decision problems with logic, constraints, probability, and utility. The benefits are threefold. The first is to offer an integrated representation and reasoning mechanism for general knowledge-based decision analysis problems. The second is to provide support to automatic or computer-aided construction of decision trees from the declarative representation of decision problems so that a decision maker can get an intuitive decision scenario from decision trees without manual labor. Last of all, the mechanism of constraint propagation provided by CLP significantly reduces the complexity of decision trees by removing infeasible solutions. (C) 2002 Elsevier Science B.V. All rights reserved.
In this paper we study the relationship between constraintprogramming (CP) and Shortest Path (SP) problems. In particular, we show that classical, multicriteria, partially ordered, and modality-based SP problems can ...
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In this paper we study the relationship between constraintprogramming (CP) and Shortest Path (SP) problems. In particular, we show that classical, multicriteria, partially ordered, and modality-based SP problems can be naturally modeled and solved within the Soft constraint logic programming (SCLP) framework, where logicprogramming is coupled with soft constraints. In this way we provide this large class of SP problems with a high-level and declarative linguistic support whose semantics takes care of both finding the cost of the shortest path(s) and also of actually finding the path(s). On the other hand, some efficient algorithms for certain classes of SP problems can be exploited to provide some classes of SCLP programs with an efficient way to compute their semantics.
Multi Agent Systems (MAS) have become the key technology for decomposing complex problems in order to solve them more efficiently, or for problems distributed in nature. However, many industrial applications besides t...
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Multi Agent Systems (MAS) have become the key technology for decomposing complex problems in order to solve them more efficiently, or for problems distributed in nature. However, many industrial applications besides their distributed nature, also involve a large number of parameters and constraints among them, i.e. they are combinatorial. Solving such particularly hard problems efficiently requires programming tools that combine MAS technology with a programming schema that facilitates the modeling and solution of constraints. This paper presents MACLP (Multi Agent constraint logic programming), a logic-programming platform for building, in a declarative way, multi agent systems with constraint-solving capabilities. MACLP extends CSPCONS, a logicprogramming system that permits distributed program execution through communicating sequential Prolog processes with constraints, by providing all the necessary facilities for communication between agents. These facilities abstract from the programmer all the low-level details of the communication and allow him to focus on the development of the agent itself. (C) 2002 Elsevier Science Inc. All rights reserved.
In this paper, we present a framework for automatic generation of CHR solvers given the logical specification of the constraints. This approach takes advantage of the power of tabled resolution for constraintlogic pr...
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In this paper, we present a framework for automatic generation of CHR solvers given the logical specification of the constraints. This approach takes advantage of the power of tabled resolution for constraint logic programming, in order to check the validity of the rules. Compared to previous work (Apt and Monfroy 1999;Ringeissen and Monfroy 2000;Abdennadher and Rigotti 2000;Abdennadher and Rigotti 2001a), where different methods for automatic generation of constraint solvers have been proposed, our approach enables the generation of more expressive rules (even recursive and splitting rules) that can be used directly as CHR solvers.
Numerous real-life problems require certain variables to be assigneddifferent values. This requirement is encapsulated in constraints of difference. If x_1, x_2 denotetwo problem variables, the (nonlinear) constraint ...
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Numerous real-life problems require certain variables to be assigneddifferent values. This requirement is encapsulated in constraints of difference. If x_1, x_2 denotetwo problem variables, the (nonlinear) constraint of difference is x_1 ≠ x_2. Given that variablesx_1,..., x_n must all be pairwise different, a constraint of the type all_different(x_1,..., x_n)can be used to formulate in a compact manner the n(n - 1)/2 binary constraints of difference. Suchan n-ary constraint is also called a predicate because it imposes a logical condition on itsvariable set. constraintprogramming (CP) makes use of such elaborate predicates in order to providea natural modeling framework. Such models are solved by CP techniques designed to produce feasiblesolutions. Alternatively, Integer programming (IP) methods can be employed in cases where a logicpredicate can be represented by linear inequalities involving integer variables. Apparently, suchrepresentations are important not only because they enrich the arsenal of resolution techniques butalso because they motivate the integration of CP and IP in a unified modeling and algorithmicframework.
A grammar formalism based upon CHR is proposed analogously to the way Definite Clause Grammars are defined and implemented on top of Prolog. These grammars execute as robust bottom-up parsers with an inherent treatmen...
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A grammar formalism based upon CHR is proposed analogously to the way Definite Clause Grammars are defined and implemented on top of Prolog. These grammars execute as robust bottom-up parsers with an inherent treatment of ambiguity and a high flexibility to model various linguistic phenomena. The formalism extends previous logicprogramming based grammars with a form of context-sensitive rules and the possibility to include extra-grammatical hypotheses in both head and body of grammar rules. Among the applications are straightforward implementations of Assumption Grammars and abduction under integrity constraints for language analysis. CHR grammars appear as a powerful tool for specification and implementation of language processors and may be proposed as a new standard for bottom-up grammars in logicprogramming.
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