We present novel branch-and-check and logic-based Benders decomposition techniques for the Travelling Purchaser Problem, an important optimization problem with applications in vehicle routing, logistics, and warehouse...
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ISBN:
(数字)9783319339542
ISBN:
(纸本)9783319339542;9783319339535
We present novel branch-and-check and logic-based Benders decomposition techniques for the Travelling Purchaser Problem, an important optimization problem with applications in vehicle routing, logistics, and warehouse management. Our master problem determines a set of markets and directed travel arcs that satisfy product purchase constraints with relaxed travel costs. Our subproblem identifies subtours within this master assignment and produces a set of generalized subtour elimination cuts. We show that the proposed technique demonstrates strong performance on the asymmetric problem variants, finding optimal solutions to previously unsolved instances, while performing competitively on a number of symmetric problem classes. Furthermore, our model is implemented unchanged for the four problem variants whereas other state-of-the-art approaches are variant-specific.
Most of contemporary software systems are implemented using an object-oriented approach. Modeling phases – during which software engineers analyze requirements to the future system using some modeling language – are...
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We present a new approach for solving first-order Markov decision processes combining first-order state abstraction and heuristic search. In contrast to existing systems, which start with propositionalizing the decisi...
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We present a new approach for solving first-order Markov decision processes combining first-order state abstraction and heuristic search. In contrast to existing systems, which start with propositionalizing the decision process and then perform state abstraction on its propositionalized version we apply state abstraction directly on the decision process avoiding propositionalization. Secondly, guided by an admissible heuristic, the search is restricted to those states that are reachable from the initial state. We demonstrate the usefulness of the above techniques for solving first-order Markov decision processes within a domain dependent system called FluCaP which participated in the probabilistic track of the 2004 international Planning Competition. Working toward a domain independent implementation we present novel approaches to θ-subsumption involving literal and object contexts.
asprin offers a framework for expressing and evaluating combinations of quantitative and qualitative preferences among the stable models of a logic program. In this paper, we demonstrate the generality and flexibility...
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this volume contains the refereed proceedings of the 13thinternationalconference on logicprogramming and Nonmonotonic Reasoning, LPNMR 2015, held in September 2015 in Lexington, KY, USA. the 290long and 11 short pa...
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ISBN:
(数字)9783319232645
ISBN:
(纸本)9783319232638
this volume contains the refereed proceedings of the 13thinternationalconference on logicprogramming and Nonmonotonic Reasoning, LPNMR 2015, held in September 2015 in Lexington, KY, USA. the 290long and 11 short papers presented together with 3 invited talks, the paper reporting on the Answer Set programming competition, and four papers presented by LPNMR student attendees at the doctoral consortium were carefully reviewed and selected from 60 submissions. LPNMR is a forum for exchanging ideas on declarative logicprogramming, nonmonotonic reasoning, and knowledge representation. the aim of the LPNMR conferences is to facilitate interactions between researchers interested in the design and implementation of logic-based programming languages and database systems, and researchers who work in the areas of knowledge representation and nonmonotonic reasoning.
Answer Set programming (ASP) is a powerful declarative programming paradigm that has been successfully applied to many different domains. Recently, ASP has also proved successful for hard optimization problems like co...
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High-performance SAT solvers based on systematic search generally use either conflict driven clause learning (CDCL) or lookahead techniques to gain efficiency. Both styles of reasoning can gain from a preprocessing ph...
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High-performance SAT solvers based on systematic search generally use either conflict driven clause learning (CDCL) or lookahead techniques to gain efficiency. Both styles of reasoning can gain from a preprocessing phase in which some form of deduction is used to simplify the problem. In this paper we undertake an empirical examination of the effects of several recently proposed preprocessors on both CDCL and lookahead-based SAT solvers. One finding is that the use of multiple preprocessors one after the other can be much more effective than using any one of them alone, but that the order in which they are applied is significant. We intend our results to be particularly useful to those implementing new preprocessors and solvers.
thanks to the high expressive power and the rule-based nature of declarative languages, their influences are growing in the fields of AI, knowledge representation, and so on. On the other hand, since the notion of &qu...
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ISBN:
(纸本)9783642140549
thanks to the high expressive power and the rule-based nature of declarative languages, their influences are growing in the fields of AI, knowledge representation, and so on. On the other hand, since the notion of "equality" plays a crucial role on such languages, in this paper we focus in the design of a flexible (fuzzy) but efficient (lazy) notion of equality for hybrid declarative languages amalgamating functional-fuzzy-logic features. Here, we show that, by extending at a very low cost the notion of "strict equality" typically used in lazy functional-logic languages (Curry, Toy), and by relaxing it to the more flexible one of similar equality used in fuzzy-logicprogramming languages (Likelog, Bousi similar to Prolog), similarity relations can be successfully treated while mathematical functions are lazily evaluated in a given program. Our method represents a very easy, low-cost way, for fuzzifying lazy functional-logic languages and it can be implemented at a very high abstraction level by simply performing a static pre-process at compilation time which only manipulates the program at a syntactic level (i.e., the underlying operational mechanism based on rewriting/narrowing remains untouched).
We present a, formally specified first order temporal logic. We give its syntax, semantics, and describe its implementation using the Eclipse constraint logicprogramming language. the main feature of the implementati...
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ISBN:
(纸本)3540676899
We present a, formally specified first order temporal logic. We give its syntax, semantics, and describe its implementation using the Eclipse constraint logicprogramming language. the main feature of the implementation is a graphical user interface. Because color coded symbols and graphs are used, the interface assumes no logical knowledge on the part of the user.
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