Studia Informatica


Volume: 2(9)
Year: 2007
Publishing: Publishing House of University of Podlasie
Scientific Editor: Andrzej Wisniewski
ISSN: 1731-2264

Contents

Drabowski M.,
Coherent synthesis of heterogeneous system – an ant colony optimization approach
pp. 9-18
Abstract: The paper presents an innovative approach to solving the problems of computer system synthesis based on ant colony optimization method. We describe algorithm realizations aimed to optimize resource, selection and task scheduling, as well as the adaptation of those algorithms for coherent synthesis realization. We then present selected analytical experiments proving the correctness of the coherent synthesis concept and indicate its practical motivations.
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Świtalski P., Seredynski F.,
Game Theoretical Model Applied to Scheduling in Grid Computing
pp. 19-27
Abstract: We consider a grid computational model which consist of a number of computation nodes and a number of users. Each user generates a computation load (jobs) requesting computational and communication resources. A deadline for each job is also defined. We propose a scheduling algorithm which is based on Iterated Prisoner's Dilemma (IPD) under the Random Pairing game, where nodes (players) of the grid system decide about their behavior: cooperate or defect. In this game players play a game with randomly chosen players and receive payoffs. Each player has strategies which define its decision. Genetic algorithm (GA) is used to evolve strategies to optimize a criterion related to scheduling problem. In this paper we show that GA is able to discover a strategy in the IPD model providing a cooperation between node-players, which permits to solve scheduling problem in grid.
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Wasielewska K., Seredynski F.,
LCS Approach to Tasks Scheduling Problem in the Two Processor System
pp. 29-39
Abstract: In this paper we propose an approach to solve multiprocessor scheduling problem with use of rule-based learning machine – Learning Classifier System (LCS). LCS combines reinforcement learning and evolutionary computing to produce adaptive systems. We interpret the multiprocessor scheduling problem as multi-step problem, where a feedback is given after some number steps. We show that LCS is able to solve scheduling tasks of a parallel program in the two processor system.
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Tobiasz M., Śmierzchalski R.,
Formation control of marine vehicles during replenishment operations
pp. 43-53
Abstract: Formation control consists in stabilising distances between ships during their motion at the same speed. Due to necessary coordination of motion of the ships, a structure is composed which allows constant distance to be kept between the ships with an assumed accuracy. Formation control makes use of the Leader-Follower algorithm. The steering structure includes the superior formation controller and real-time trajectory controllers. Direct course and speed steering is executed using PD fuzzy controllers. The application of advanced technologies provides opportunities for reducing the number of crew involved in at-sea reloading activities and increasing ship safety during operations of this type.
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Lach E.,
Automatic Strategies for Autonomous Virtual Characters
pp. 57-68
Abstract: Technique presented in the paper concerns automatic generation of strategies controlling virtual characters’ behaviour. Virtual people are currently widely used in many applications, especially in computer games, films and educational systems. A lot of researches focus on creating intelligent characters capable of deciding about their actions. The fully acceptable solution has not yet been found. The paper presents the problem of generating strategies by means of modified genetic programming. A new Guide-Path technique is introduced.
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Wisniewski A.,
Critical Phenomena: Towards Modeling with Cellular Automata
pp. 69-76
Abstract: The paper presents basic description methods of critical phenomena, i.e. first-order, continuous phase transitions, and an overview of the self-organized criticality concept. In this approach an attempt is made to identify the determinant factors of modeling critical events using cellular automata.
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