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  1. 6 Applied Computer Science
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  1. 6 Banaszak Z.
  2. 5 Bocewicz G.
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1
Content available Constraint Programming for Flexible Flow Shop Scheduling Problem with Repeated Jobs and Repeated Operations
Czerniachowska Kateryna, Wichniarek Radosław, Żywicki Krzysztof
Advances in Science and Technology. Research Journal
|
2023
|
Vol. 17, no 3
280--293
EN
The manufacturing process relies heavily on production scheduling to guarantee effective production schedules, reduce costs and product shortages, and get away from delays, interruptions, and waste products. Scheduling issues have been effectively solved via constraint programming. In this paper, we consider a constraint programming formulation of the flexible flow shop scheduling problem with repeated jobs and operations repetitions. We also implemented seven fast heuristics and compared the results with the constraint programming solution. The results from using the CPLEX solver as a solution tool were satisfactory. Computational experiments demonstrate that using constraint programming can be significantly more advantageous than using heuristics.
2
Content available Some efficient algorithms to deal with redundancy allocation problems
Es-Sadqi Mustapha, Idrissi Abdellah, Benhassine Ahlem
Journal of Automation Mobile Robotics and Intelligent Systems
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2020
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Vol. 14, No. 4
48--57
EN
In this paper, we will discuss some algorithms in order to better optimize the problems of redundancy allocation in multi-state systems. The goal is to find the optimal configuration of the system that maximizes the availability and minimizes the investment cost. The availability will be evaluated using the universal generating function. In first step, our contribution consists in improving the genetic algorithm. In a second step, in the framework of the Constraint Programming, we propose a new method of optimization based on the Forward Checking as solver. Finally, we used the top-k method in our choice that helps us to get the best k elements from all possible values with highest availability. In comparison with the chosen study, our methods yield better results that satisfy the constraints of the problem in a shorter time.
3
Content available remote Automated generation of business process models using constraint logic programming in Python
Paszun Tymoteusz, Wiśniewski Piotr, Kluza Krzysztof, Ligęza Antoni
Annals of Computer Science and Information Systems
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2019
|
Vol. 18
733--742
EN
High complexity of business processes in real-life organizations is a constantly rising issue. In consequence, modeling a workflow is a challenge for process stakeholders. Yet, to facilitate this task, new methods can be implemented to automate the phase of process design. As a main contribution of this paper, we propose an approach to generate process models based on activities performed by the participants, where the exact order of execution does not need to be specified. Nevertheless, the goal of our method is to generate artificial workflow traces of a process using Constraint Programming and a set of predefined rules. As a final step, the approach was implemented as a dedicated tool and evaluated on a set of test examples that prove that our method is capable of creating correct process models.
4
Content available Off-line and dynamic production scheduling - a comparative case study
Bożek A., Wysocki M.
Management and Production Engineering Review
|
2016
|
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.
5
Content available remote Nondeterministic Programming in Java with JSetL
Rossi G., Bergenti F.
Fundamenta Informaticae
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2015
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Vol. 140, nr 3/4
393--412
EN
JSetL is a Java library that endows Java with a number of facilities that are intended to support declarative and constraint (logic) programming. In this paper we show how JSetL can be used to support general forms of nondeterministic programming in an object-oriented framework. This is obtained by combining different but related facilities, such as logical variables, set data structures, unification, along with a constraint solver that allows the user to solve nondeterministic constraints as well as to define new constraints using the nondeterminism handling facilities provided by the solver itself. Thus, the user can define her/his own general nondeterministic procedures as new constraints, letting the constraint solver handle them. The proposed solutions are illustrated through a number of concrete Java programs using JSetL, including the implementation of simple Definite Clause Grammars.
6
Content available Optimization of sugar dispatching process
Pytlak R.
Research in Logistics & Production
|
2014
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Vol. 4, No. 2
105--118
7
Content available Optymalizacja procesu wysyłki cukru
Pytlak R., Stecz W.
Gospodarka Materiałowa i Logistyka
|
2014
|
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.
8
Content available remote Coalitions of Arguments : An Approach with Constraint Programming
Bistarelli S., Santini F.
Fundamenta Informaticae
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2013
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Vol. 124, nr 4
383--401
EN
The aggregation of generic items into coalitions leads to the creation of sets of homogenous entities. In this paper we accomplish this for an input set of arguments, and the result is a partition according to distinct lines of thought, i.e., groups of 'coherent' ideas. We extend Dung's Argumentation Framework (AF) in order to deal with coalitions of arguments. The initial set of arguments is partitioned into not-intersected subsets. All the found coalitions show the same property inherited by Dung, e.g., all the coalitions in the partition are admissible (or conflict-free, complete, stable): they are generated according to Dung's principles. Each of these coalitions can be assigned to a different agent. We use Soft Constraint Programming as a formal approach to model and solve such partitions in weighted AFs: semiring algebraic structures can be used to model different optimization criteria for the obtained coalitions. Moreover, we implement and solve the presented problem with JaCoP, a Java constraint solver, and we test the code over a small-world network.
9
Content available remote Morphos Configuration Engine: the Core of a Commercial Configuration System in CLP(FD)
Campagna D., De Rosa C., Dovier A., Montanari A., Piazza C.
Fundamenta Informaticae
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2011
|
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.
10
Content available Models and tools for improving efficiency in Constraint Logic Programming
Ligęza A.
Decision Making in Manufacturing and Services
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2011
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Vol. 5, no. 1-2
69-78
EN
Constraint Satisfaction Problems typically exhibit strong combinatorial explosion. In this paper we present some models and techniques aimed at improving efficiency in Constraint Logic Programming. A hypergraph model of constraints is presented and an outline of strategy planning approach focused on entropy minimization is put forward. An example cryptoaritmetic problem is explored in order to explain the proposed approach.
11
Content available CP-based decision support for scheduling
Relich M.
Applied Computer Science
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2011
|
Vol. 7, no 1
7-17
EN
The paper presents the declarative approach to design of a reference model aimed at project prototyping. The reference model contains the finite set of decision variables, their domains and linking those constraints, i.e. can be seen as a kind of Constraint Satisfaction Problem. Consequently, the model considered can be treated as a knowledge base specifying both a class of enterprises and the projects that could be conducted on their base. So, the model provides a platform for rapid prototyping of alternative versions of project scheduling. The routine queries can be formulated in the straight or reverse way. In that context, the proposed reference model can be implemented in constraint programming (CP) techniques
12
Content available remote A method involving constraint programming for generating integral graphs without ± 1 in the spectrum : a case study
Zwierzyński K., Meissner A., Niwińska M.
Studia z Automatyki i Informatyki
|
2010
|
T. 35
105-114
EN
We consider a method where the constraint programming over finite domains is used for describing relationships among some properties of graphs. The process of constraint solving results in the set of values, which act as input parameters for the graph generation algorithm. In this way, the space of possibly generated graphs is reduced. We present a case study of the application of this approach to the problem of finding all connected, integral, non-regular and bipartite graphs, with a maximum vertex degree four not containing ± 1 in the spectrum (i.e., SL4-graphs).
PL
W artykule rozważa się wariant metody konstruowania grafów poprzez generowanie a następnie przeszukiwanie klas grafów, do których należą rozpatrywane grafy. Proponuje się przy tym zastosowanie metodyki programowania z więzami (ang. constraint programming over finite domains) do opisywania zależności, jakie zachodzą między niektórymi właściwościami grafów. W ten sposób ogranicza się a zarazem precyzuje zbiór parametrów algorytmu generującego grafy. W konsekwencji, zostaje zredukowana przestrzeń, którą należy przeszukiwać. Praca zawiera analizę przykładu zastosowania tego ujęcia do skonstruowania wszystkich spójnych, nieregularnych, dwudzielnych grafów całkowitych o maksymalnym stopniu wierzchołków równym 4 niezawierających ± 1 w spektrum.
13
Content available remote Zastosowanie technik programowania z ograniczeniami do planowania zadań w środowiskach wieloprojektowych
Bocewicz G., Banaszak Z., Bach I.
Pomiary Automatyka Robotyka
|
2009
|
R. 13, nr 2
152-164
PL
Efektywne wykorzystanie zdolności produkcyjnych stanowi o konkurencyjności dysponującego nimi przedsiębiorstwa. W tym kontekście istotnego znaczenia nabierają badania związane z planowaniem zadań w przedsięwzięciach. Przedstawiony model referencyjny problemu decyzyjnego łączy oczekiwania użytkownika z możliwościami wykorzystania dostępnych zdolności realizacji przedsięwzięć. Z kolei jego specyfikacja, w terminach problemu spełniania ograniczeń, pozwala na ocenę alternatywnych wariantów przebiegu przedsięwzięć w systemach programowania z ograniczeniami.
EN
The way enterprise capabilities are used decides about its competitiveness among other ones. In that context modeling aimed at production tasks allocation planning plays a crucial role especially at concurrently executed production orders. The introduced reference model employing constraint programming (CP) paradigm describes both an enterprise and a set of project-like production orders. Moreover, encompassing consumer orders requirements and available production capabilities, the model provides the formal framework allowing one to develop a class of decision support systems aimed at interactive production process planning subject to multiproject environment constraints.
14
Content available remote CP-driven approach to multicriteria decision making based on imprecise data
Bach I., Bocewicz G.
Foundations of Computing and Decision Sciences
|
2008
|
Vol. 33, No. 2
119-130
EN
Multi-criteria decision-making encompass different aspects of Small and Medium Size Enterprise functioning, e.g. money flow, personnel allocation, task oriented scheduling, etc. In general multi-criteria decision making is aimed at determining an company preferences (e.g. financial benefits, intangible benefits, availability of resources, risk level, etc.), and customers requirements (e.g. specified by the time of implementation and budget of the relevant production orders). Moreover all decisions are usually time and financially constrained. Considering above, decision problems are specified by the diverse character of information (including distinct and imprecise data). The approach considered regards of the Logic-Algebraic Method based and Constraint Programming methodology aimed at interactive and multi-criteria decision making. In case the data introduced are specified by a membership function its representation can be discretized and replaced by an ordered set of discrete values. It means, instead of standard fuzzy-set-like operations, e.g. fuzzy complement, intersection, union, and fuzzy inference rules, a set of constraints is considered. In such approach both: distinct and imprecise data as well as linking them relations are treated in a unified form of discrete Constrained Satisfaction Problem. Moreover, implementation of multi-criteria decision making directly follows from the nature of constraint programming paradigm (constraints propagation and variables distribution). The way of possible approach implementation is illustrated in the example enclosed.
15
Content available remote Filtering algorithms for the unary resource constraint
Vilim P.
Archives of Control Sciences
|
2008
|
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.
16
Content available Knowledge based and CLP-driven approach to multi-robot task allocation for multiproduct job shop
Bocewicz G., Mądry M., Banaszak Z.
Applied Computer Science
|
2008
|
Vol. 4, no 1
18--29
EN
Constraint Programming (CP) is an emergent software technology for declarative description and effective solving of large combinatorial problems especially in the area of integrated production planning. In that context, CP can be considered as an appropriate framework for development of decision making software supporting scheduling of multi-robot in a multi-product flow shop. The paper deals with multi-resource problem in which more than one shared renewable resource type may be required by manufacturing operation and the availability of each type is time-windows limited. The problem belongs to a class of NP-complete ones. The aim of the paper is to present a knowledge based and CLP-driven approach to multi-robot task allocation framework providing a prompt service to a set of routine queries stated both in straight and reverse way. Provided example concentrates on the first case taking into account both an accurate and an uncertain specification of robots operation time..
17
Content available Decision support tool for projects portfolio prototyping
Bocewicz G., Bach I., Banaszak Z.
Applied Computer Science
|
2008
|
Vol. 4, no 2
43--62
EN
Constraint Programming (CP) is an emergent software technology for declarative description and effective solving of large combinatorial problems especially in the area of projects portfolio prototyping. The paper deals with multi-resource and multi-criteria problem in which more than one shared renewable resource type may be required by manufacturing operation and the availability of each type is time-windows limited. The problem belongs to a class of NP-complete ones. The aim of the paper is to present a knowledge based and CP-driven approach to resource allocation conflicts resolution framework. Proposed framework stands behind a methodology aimed at task oriented DSS tolls designing. The Portfolio Project Prototyping System designed due to this methodology provides a prompt and interactive service to a set of routine queries stated both in straight and reverse way. Multiple illustrative examples are discussed.
18
Content available Towards intelligent decision support for application service providing
Sitek P., Wikarek J.
Applied Computer Science
|
2007
|
Vol. 3, no 1
125--142
EN
Decision support systems (DSS) provide decision-makers with an interactive environment for analyses of information with various models to help solve unstructured and NP-hard problems. The important aspect of DSS is a technical and technological approach to the design and implementation of the above systems. A traditional approach to DSS engineering and implementation requires a great deal of effort for its maintenance. However, the enterprises would like to concentrate on its core competitiveness instead of non-core activities like IT maintenance. As a result of this, IT outsourcing has became a very popular event. Thus there is a growing need for intelligent decision support tools capable of assisting a decision maker in many problems in SMEs (Small and Medium Sized Enterprises). In this paper we present the use of declarative programming (constraint logic programming and relational SQL database) as an environment and framework for such decision support systems in an application service providing (ASP) model.
19
Content available Implementation of declarative framework for decision support system in scheduling problems
Sitek P., Wikarek J.
Applied Computer Science
|
2007
|
Vol. 3, no 2
69--86
EN
Scheduling problems appear frequently at different levels of decisions. They are usually characterized by many types of constraints, which make them unstructured and difficult to solve (NP-complete). Traditional mathematical programming approaches are deficient because their representation of constraints is artificial (using 0-1 variables). Unlike traditional approaches, constraint logic programming (CLP) provides for a natural representation of heterogeneous constraints. In CLP we state the problem requirements by constraints; we do not need to specify how to meet these requirements. In this paper we propose a declarative framework for decision support system (DSS) for constrained search problems implemented by CLP and relational SQL database. We illustrate this concept by the implementation of a DSS for scheduling problems with external resources in different production organization environments.
20
Content available remote Constraint satisfaction problem based modelling and value ordering based heuristic for nurse scheduling
Djeffal L., Goncalves G., Babes M.
Journal of Applied Computer Science
|
2006
|
Vol. 14, nr 2
7-28
EN
Nurse Scheduling Problem (NSP) consists of assigning shift-types (morning, afternoon and night) to qualified personnel over a certain planning period. It is a difficult and time-consuming task. In this paper we present a formulation of the hospital Nurse Scheduling Problem just like Constraint Satisfaction Problem "CSP" based constraint programming in order to find a solution, which minimizes the violation of Nurses' preferences. We would suggest a flexibility tool for helping to decide and for making negotiation easier. Our originality lies in the modelling of the problem, by defining the global constraints and in the algorithm of resolution to solve it, by proposing a new value ordering based heuristic for assignment of the decision variables taking into account the set of Nurses preferences. Our heuristic is based on the structure of the CSP and on the properties of constraints. It allows the reduction of the search space for solution and returns a solution within few second.
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