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Applied Computer Science Volume 3, Number 2, 2007

COONSTRAINT PROGRAMMING APPROACH TO MULTIPRODUCT SCHEDULING

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 small and medium sized enterprises (SMEs) in the course of projects portfolio prototyping. The problem considered aims at finding a computationally effective approach for scheduling a new projects portfolio subject to constraints imposed by an availability of time-constrained resources. The problem belongs to a class of multi-mode project scheduling problems where the problem of finding a feasible solution is NP-complete. The aim of the paper is to present a CP modeling framework providing a prompt service to a set of routine queries stated both in straight and reverse way, e.g., concerning the projects portfolio makespan implied by a given resources allocation, and the feasible resources allocation guaranteeing an assumed projects portfolio makespan. The way the responses to the routine requests can be guaranteed while may be available in an on-line mode is illustrated in the example enclosed.

GENETIC ALGORITHM AS OPTIMIZING TOOL IN LINE BALANCING PROCESS

This article deals with assembly line balancing problem and with possibility of using genetic algorithm as an optimizing tool in balancing process. There is briefly described line balancing problem and the main goals of balancing. Also it is shown here how genetic algorithm work and what are the advantages of this tool.

IMPLEMENTATION OF DECLARATIVE FRAMEWORK FOR DECISION SUPPORT SYSTEM IN SCHEDULING PROBLEMS

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.

USING VIRTUAL REALITY TO DEVELOP SIX LEGGED WALKING ROBOT CONTROL SYSTEM

This contribution presents the first results of our work related to design and development of a six legged walking robot. Real prototype was created along with its virtual counterpart that is simulated in virtual environment. A control system was created and tested on virtual model. This control system was then directly used to control real robotic construction.

COMPUTER VISION BASED UGV STEERING

This report deals with a computer vision system for unmanned ground vehicle. The concentrated aspects include the comparison between image and model and intrinsic and extrinsing parameters of camera.

METHODOLOGY FOR ANALYSIS OF FUNCTIONING AND IMPROVEMENT OF PRODUCTION SYSTEMS BASING ON COMPUTER SIMULATION

Modelling and simulation with optimization finds wide usage in the improvement of production systems. Production systems are so complex, that without computer it is not possible to realize detailed analysis of processes taking place in them. The methodology for realization of simulation projects with ARENA for improving production processes is presented in this paper.

THE IMPACT OF ERP SYSTEM ON ECONOMIC SITUATION OF ENTERPRISE: CASE STUDY

The implementation of ERP system is performed to integrate business processes, efficient charge of company resources and give important data for decision support. Implementing of ERP system is expensive and time consuming. Therefore a great number of research activities are focused on key success factors of ERP implementations but only few deals with long term impact of ERP system on enterprise performance. In the article the relationship between implementation of ERP and values of important economic ratios of enterprises is analyzed. The analysis is a base for presented evaluation methodology of ERP system from economic point of view. As an example, an enterprise is taken into
account that implemented ERP system in 2001. The illustrative examples are given.

SAFE MANUAL HANDLING IN INDUSTRIAL PRODUCTION

This section provides the technical information for using the revised lifting equation to evaluate a variety of two-handed manual lifting tasks. Definitions, restrictions/limitations, and data requirements for the revised lifting equation are also provided.

SYSTEMIC ANALYSIS OF MODELS OF DYNAMIC SYSTEMS OF SHAFT MACHINING IN ELASTICDEFORMABLE CONDITION

The paper presents methodology of developing models of dynamic systems of machining shafts in the elastic-deformable condition. The specifics of dynamic system (DS) identification concerning straight turning and straight and plunge grinding of low-rigidity shafts is presented. The specifics of the process of lowrigidity elements machining is taken into account through the introduction of suitable equations of constraint reflecting additional elastic strain in one of the equations describing the control force effect. Systemic analysis of the developed models is performed, and their hierarchical structure is given.