Wyniki wyszukiwania - Biblioteka Nauki

1

Morphos Configuration Engine: the Core of a Commercial Configuration System in CLP(FD)

100%

Campagna D. , De Rosa C. , Dovier A. , Montanari A. , Piazza C.

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2011

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tom Vol. 105, nr 1/2

105-133

EN

Product configuration systems are an emerging software technology that supports companies in deploying mass customization strategies. In this paper, we describe a CLP-based reasoning engine that we developed for a commercial configuration system. We first illustrate the advantages of the CLP approach to product configuration over other ones. Then, we describe the actual encoding of the considered product configuration problem as a constraint satisfaction problem. We devote a special attention to the key issues of constraint propagation and optimization as well as to the relevant process of assignment revision. A comparison with existing systems for product configuration concludes the paper.

2

Constraint-based scheduling in Oz/Mozart

100%

Sitek P. , Wikarek J. , Banaszak Z.

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tom Vol. 2, no 1

83--99

EN

In this paper we present how scheduling problems can be solved in the concurrent constraint programming (CCP) language Oz. Oz is the first high- level constraint language, which offers programmable search, modularity, expressiveness and an interface to invent new constraints using C++. As an example of scheduling problem the job-shop scheduling problem with manpower resources representation was considered. The objective discussed here is the minimization of the makespan. Allocating manpower to the jobs is more complicated than allocating machines, as different jobs and operations require different manpower. This problem is strongly NP-hard. We proposed the constraint programming (CP) based approach to decision support in this environment. The most important features of CP are declarative problem modeling, allowing a clear separation between the problem statement (variables and constraints) and the resolution of the problem.

3

Filtering algorithms for the unary resource constraint

88%

Vilim P.

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tom Vol. 18, no. 2

159-202

EN

Scheduling is one of the most successful application areas of constraint programming mainly due to special global constraints designed to model resource restrictions. Among scheduling constraints, the most useful and most studied constraint is probably the unary resource constraint. This paper presents state-of-the-art filtering algorithms for this important constraint. These algorithms are very fast (almost all of them has time complexity O(n log n) and furthermore they are able to take into account so called optional activities, that is, activities which may or may not appear in the schedule depending for example on a resolution of an alternative processing rule(s). In particular, this paper presents the following algorithms: overload checking, edge finding, not-first/not-last, detectable precedences and precedence energy.

4

Optymalizacja procesu wysyłki cukru

63%

Pytlak R. , Stecz W.

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tom nr 2

21--30

PL

W artykule rozważany jest proces wysyłki cukru do klientów cukrowni. Podstawowym celem naszej pracy było określenie efektywności procesów logistycznych w fabryce oraz znalezienie i korekta wąskich gardeł. Zaprezentowano wybrane sposoby optymalizacji procesów logistycznych. W pracy, dla potrzeb harmonogramowania, prezentujemy zastosowanie metod heurystycznych oraz metod wykorzystujących programowanie z ograniczeniami. Praca przedstawia również dyskusję metod optymalizacji procesów logistycznych oraz omawia trudności z ich zastosowaniem.

EN

We consider the sugar dispatching process at a sugar mill. The main goal of our work was to check an efficiency of the logistics system in the mill, find and correct the bottlenecks. Some methods for logistics processes optimization are presented. We base on the heuristics and CLP techniques for solving the scheduling problems. Some additional remarks about possibility of using the optimization methods in scheduling and logistics optimizations are presented too.

5

Optymalizacja procesu wysyłki cukru

63%

Pytlak R. , Stecz W.

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nr 2

21-30

EN

We consider the sugar dispatching process at a sugar mill. The main goal of our work was to check an efficiency of the logistics system in the mill, find and correct the bottlenecks. Some methods for logistics processes optimization are presented. We base on the heuristics and CLP techniques for solving the scheduling problems. Some additional remarks about possibility of using the optimization methods in scheduling and logistics optimizations are presented too.

6

Off-line and dynamic production scheduling - a comparative case study

63%

Bożek A. , Wysocki M.

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tom Vol. 7, No. 1

21--32

EN

A comprehensive case study of manufacturing scheduling solutions development is given. It includes highly generalized scheduling problem as well as a few scheduling modes, methods and problem models. The considered problem combines flexible job shop structure, lot streaming with variable sublots, transport times, setup times, and machine calendars. Tabu search metaheuristic and constraint programming methods have been used for the off-line scheduling. Two dynamic scheduling methods have also been implemented, i.e., dispatching rules for the completely reactive scheduling and a multi-agent system for the predictivereactive scheduling. In these implementations three distinct models of the problem have been used, based on: graph representation, optimal constraint satisfaction, and Petri net formalism. Each of these solutions has been verified in computational experiments. The results are compared and some findings about advantages, disadvantages, and suggestions on using the solutions are formulated.