Communications - Scientific Letters of the University of Zilina, 2008 (vol. 10), issue 2
Articles
Computability of the Emergency Service System Design Problem
Jaroslav Janacek, Ludmila Janosikova
Communications - Scientific Letters of the University of Zilina 2008, 10(2):5-9 | DOI: 10.26552/com.C.2008.2.5-9 
The paper deals with emergency medical system design using methods of mathematical programming. The problem consists in optimal location of stations, where ambulance vehicles should be placed. Several possible objective functions are discussed and the relevant mathematical programming models are presented. The comparison of the solutions is reported based on the computational experiments in the conditions of the Slovak Republic.
Villon - A Tool for Simulation of Operation of Transportation Terminals
Norbert Adamko, Peter Marton
Communications - Scientific Letters of the University of Zilina 2008, 10(2):10-14 | DOI: 10.26552/com.C.2008.2.10-14
The paper deals with the modelling of transportation terminals operation (e.g. marshalling yards, factories, train care centres, airports, etc.) utilizing generic simulation tool Villon, which was developed using agent based simulation architecture ABAsim. Villon is complete simulation tool providing support for creation, configuration, experimentation and results evaluation tasks connected with simulation modelling of transportation terminals. Villon's unique features like its flexibility, detailed microscopic modelling of operation of various types of terminals, flowchart driven definition of operational procedures, user interaction, selection of...
Improvement of Road Tunnel Ventilation through Predictive Control
Jozef Hrbcek, Ales Janota
Communications - Scientific Letters of the University of Zilina 2008, 10(2):15-19 | DOI: 10.26552/com.C.2008.2.15-19
Design of an effective ventilation system for the road tunnel is usually a challenging task whose solution is less or more tending to optimum. Predictive control seems to be apromising approach that can help to improve properties of existing ventilation systems applied in road tunnels. Advantages of predictive control result mainly from its ability to solve both SISO and MIMO tasks, to have regard for dynamics of process changes in a broad extent, to compensate effect of measurable and non-measurable failures and to formulate the task as an "optimization control task" considering limiting conditions of control actions, changes of control actions and...
Numerical Investigation of Optical Burst Switching
Milan Dado, Stanislav Krajci, Jozef Dubovan, Dusan Sabol
Communications - Scientific Letters of the University of Zilina 2008, 10(2):20-24 | DOI: 10.26552/com.C.2008.2.20-24
The simulation analysis of aphysical layer of the "all optical burst switching" using aVPI Photonics™ simulation program is presented in this article. The optical burst networks adopt dedicated control channel to transmit headers of burst, at the same time the payload is transmitted on the other optical data channels after the offset time. We have proposed OBS network with four data channels and one control channel consisting of the following main optical elements: lasers with external modulation, awavelength converter using Kerr effect cross phase modulation (XPM) in optical semiconductor amplifiers (SOA), awavelength switch 4x4 and photodetector....
Photonic Crystals - Optical Structures for Advanced Technology
Daniel Kacik, Ivan Martincek, Dusan Pudis, Norbert Tarjanyi, Ivan Turek
Communications - Scientific Letters of the University of Zilina 2008, 10(2):25-29 | DOI: 10.26552/com.C.2008.2.25-29
This paper presents experimental results in the field of photonic crystals investigation. There are presented our results of experimental investigation of one-dimensional photonic crystals appearing in nature, two-dimensional photonic crystals we formed in LiNbO3 and thin photoresist layers and results of our investigation of chromatic dispersion of photonic crystal fibers as well as the influence of fiber bending on their transmittance.
Real Behaviour and Remaining Lifetime of Bridge Structures
Josef Vican, Jozef Gocal, Branislav Melis, Peter Kotes, Patrik Kotula
Communications - Scientific Letters of the University of Zilina 2008, 10(2):30-37 | DOI: 10.26552/com.C.2008.2.30-37
The paper presents results of research activities of the Department of Structures and Bridges in the field of investigation of the real behaviour, reliability and durability of existing bridge structures. There are introduced two cases of these research activities in the paper having significant effects on the determining bridge remaining lifetime, which is the basic information from the viewpoint of bridge rehabilitation. The third presented research activity is devoted to the possibility of bridge RC beams strengthening using the FRP lamellas and strips from the viewpoint of determining the resistance of the strengthened RC beams.
Evaluation of the Soil Elastic Modules by Means of Box Tests
Jan Bencat, Milan Cibulka, Milan Hrvol
Communications - Scientific Letters of the University of Zilina 2008, 10(2):39-43 | DOI: 10.26552/com.C.2008.2.39-43
The experimental measurements results of static and dynamic elastic modules (Es, ED) and initial tangent modules (Go, Eo) of soils evaluated by means of box tests application techniques for calculation of these modules via static and dynamic loading half - space test means (SLT, DLT) and via shear wave velocity measurements tests are given. In the cross - hole method, body wave velocities are commonly evaluated from visual determinations of arriva timel of the waves at receivers. Additional time - determination techniques based on correlation and spectral analysis are discussed. The correlation technique is based on the cross - correlation function...
Pavement Diagnosis as Integrant of the Pavement Management System
Jan Celko, Martin Decky, Jozef Komacka, Matus Kovac
Communications - Scientific Letters of the University of Zilina 2008, 10(2):44-49 | DOI: 10.26552/com.C.2008.2.44-49
The paper integrates the most important scientific information of the authors in the field of diagnostics of road pavements. Basic attributes of pavement serviceability (evenness, skid resistance) and pavement bearing capacity are the core of the paper. The results of simulations of dynamic systems, outputs of the models developed at the authors place, the correlations to the world established parameters of evenness and skid resistance are presented in the paper. Objective scientific outputs have formed an effectual base for development the Slovak Pavement Management System (PMS). The principles of the Slovak PMS are described.
Models of Processes as Components of Air Passenger Flow Model
Martin Matas, Andrej Novak
Communications - Scientific Letters of the University of Zilina 2008, 10(2):50-54 | DOI: 10.26552/com.C.2008.2.50-54
The paper presents the model of air passenger processes at airports for single source and two source processes. It shall be used as a component for the development of passenger flow model. In the paper the single source model is applied on passenger check-in process. It is based on deterministic queuing model where cumulative diagrams of the flow are used for calculations. As input data the model requires the arrival and service profile of passengers at the check-in. The arrival profile is a cumulative number of passengers arriving to the server during the time. The service profile is a cumulative number of passengers which can be served by the check-in...
The Impact of a Demographic Trend on the Demand for Scheduled Bus Transport in the Slovak Republic
Jozef Gnap, Vladimir Konecny
Communications - Scientific Letters of the University of Zilina 2008, 10(2):55-59 | DOI: 10.26552/com.C.2008.2.55-59
Scheduled bus transport is an important and irretrievable transport system from society point of view. All age groups of population use this transport system to satisfy their own transport requirements. The performance of scheduled bus transport has markedly decreased recently. The performance level is affected not only by fare prices and incomes of population but also by the change in population structure. Population represents potential demand for scheduled bus transport services.
Zilina University Concept of Digital Factory
Milan Gregor, Stefan Medvecky
Communications - Scientific Letters of the University of Zilina 2008, 10(2):60-66 | DOI: 10.26552/com.C.2008.2.60-66
This paper focuses on the Digital Factory technologies, the areas of their application, as well as its benefits for industry. The paper presents the Digital Factory concept built in the framework of co-operation of the University of Zilina and the Central European Institute of Technology (CEIT).
Increasing the Security Level in the Slovak Republic
Ladislav Simak
Communications - Scientific Letters of the University of Zilina 2008, 10(2):67-71 | DOI: 10.26552/com.C.2008.2.67-71
Increasing the security level in every country is a complicated process that affects all spheres of social life and requires a longer period of time. The improvement of the security system in the Slovak Republic has been taking place continuously since the country joined the European Union and NATO and has not been finished so far.
Discrete and Differential Equations in Applied Mathematics
Miroslava Ruzickova
Communications - Scientific Letters of the University of Zilina 2008, 10(2):72-78 | DOI: 10.26552/com.C.2008.2.72-78
In the contribution we map investigations performed in mathematics at the Faculty of Science in 2003-2007. Main directions developed at the faculty are described and some of the latest achievements are presented. We illustrate some results from control theory for discrete delayed equations, perturbed linear problems for discrete equations, results concerning the structure of solutions of delayed differential equations, results of orthogonal polynomials, and adescription of some numerical investigations in discrete least-squares and collocation methods for numerical solution of a boundary value and eigenvalue problems. Some of accompanying mathematical...