Sławomir Samolej

Distributed Internet systems modeling using TCPNs

This paper presents a timed coloured Petri nets based programming tool that supports modeling and performance analysis of distributed World Wide Web environments. A distributed Internet system model, initially described in compliance with queueing theory (QT) rules, is mapped onto the Timed coloured petri net (TCPN) structure by means of queueing system templates. Then, it is executed and analyzed using design/CPN toolset. The proposed distributed Internet systems modeling and design methodology has been applied for evaluation of several system architectures under different external loads.

HTCPNs---Based modelling and evaluation of dynamic computer cluster reconfiguration

An extension of HTCPNs-based software tool for Internet systems modelling and evaluation has been proposed in the paper. After the extension the tool provides new possibilities for modelling and analysis of dynamic cluster reconfiguration algorithm. Some implementation details of the algorithm has been presented. The algorithm has been preliminary assessed by simulation.

Using Computer Graphics, Vision and Gesture Recognition Tools for Building Interactive Systems Supporting Therapy of Children

The paper presents a prototype of a system which can be used as a therapeutic and educational tool for children with developmental problems. Natural body movements and gestures are used in the system to interact with virtual objects displayed on the screen. Nowadays such systems can be built with the use of widely available free software tools for both graphical and vision applications. Such tools are also shortly presented in the paper.

ARINC 653 Based Time-Critical Application for European SCARLETT Project

The SCAlable & ReconfigurabLe Electronics plaTforms and Tools project (SCARLETT) was started by European Commission to develop the concept of IMA 2G Avionics. The paper mentions the main objectives of the SCARLET project and presents a sample time-critical application developed for it. The time-critical application is an ARINC 653 based and is a part of a distributed control system working in AFDX network environment. Its task is to control an elevator’s actuator of a typical airliner. The paper presents the structure of the application, its timing schedule, and dedicated control algorithms and error detection mechanism built-in it. Selected application tests conclude the paper.

HTCPNs: based tool for web-server clusters development

A new software tool for web-server clusters development is presented. The tool consist of a set of predefined Hierarchical Timed Coloured Petri Net (HTCPN) structures - patterns. The patterns make it possible to naturally construct typical and experimental server-cluster structures. The preliminary patterns are executable queueing systems. A simulation based methodology of web-server model analysis and validation has been proposed. The paper focuses on presenting the construction of the software tool and the guidelines for applying it in cluster-based web-server development.

Computer vision and graphics based system for interaction with mentally and physically disabled children

The paper presents a prototype of a system which can be used as a therapeutic and educational tool for children with developmental problems. Natural body movements and gestures are used in the system to interact with virtual objects displayed on the screen. Nowadays such systems can be easily built with the use of widely available free software tools for both graphical and vision applications. Such tools are also shortly presented in the paper.

The Airspeed Automatic Control Algorithm for Small Aircraft

This paper presents selected results authors have reached during research of airspeed control algorithm developed for Single Engine Piston Light (SEPL) aircraft powered by piston engine with constant-pitch propeller in tractor configuration. There are some theoretical discussions about control law’s structure and methods of adjusting them to control plant’s operational features in this paper. Moreover, practical implementation of developed algorithm is described. Finally, results achieved both during computer simulations and flight tests are presented and discussed.

Communication and Control Software Development for Experimental Unmanned Aerial System – Selected Issues

Recently the functionality and applicability of Unmanned Aerial Systems have been dynamically growing. In the paper such an experimental system, based on the “MP-02 Czajka” ultra light plane, is presented. Generation of the C source code for the autopilot firmware in the Matlab environment is discussed. Furthermore, several issues raised during implementation of the STANAG 4586 communication protocol are considered.

Consequences of the Form of Restrictions in Coloured Petri Net Models for Behaviour of Arrival Stream Generator Used in Performance Evaluation

Coloured Petri Nets formalism is commonly used for modelling various aspects of communication systems. Simulations of such models facilitate performance evaluation. Typically during the simulation a stream of data (tokens) is produced in the part of the model called stream generator, as an input for the latter part of the model. In the paper different models of stream generators are discussed, as well as their influence on distribution of resulting tokens, during the simulation in the CPN Tools software.