Communications - Scientific Letters of the University of Zilina, 2013 (vol. 15), issue 4

Articles

Articles

Application of the Rail Vehicle's Monitoring System in the Process of Suspension Condition Assessment

Rafal Melnik, Bogdan Sowinski

Communications - Scientific Letters of the University of Zilina 2013, 15(4):3-8 | DOI: 10.26552/com.C.2013.4.3-8  

Rail vehicle's suspension determines riding dynamics, safety and comfort. Its condition should be checked regularly, and even monitored continuously. In order to acquire information on suspension condition during commercial operation, the rail vehicles' monitoring system has been developed at Monitoring of Technical State of Construction and Evaluation of its Lifespan Project (MONIT). The aim of the system is qualitative assessment of suspension condition based on acceleration signals recorded on bogie frames and body.The experimental tests of the system were performed on wagons with introduced suspension damages: stiffness reduction of primary suspension...

Contribution to the Methodology of the Determination of the Thermal Conductivity Coefficients Λ of Materials Applied in the Railway Subbase Structure

Libor Izvolt, Peter Dobes, Martin Mecar

Communications - Scientific Letters of the University of Zilina 2013, 15(4):9-17 | DOI: 10.26552/com.C.2013.4.9-17  

The paper focuses on the methodology of determination of thermal conductivity coefficients λ of the construction materials of railway subbase. The determination of the thermal conductivity coefficients λ depends on the determination of the specific heat capacity and the time interval as sub-parameters. The paper presents specialized equipment for the determination of these parameters, the stated procedures and the method of test evaluation.The paper focuses on the presentation of the results of the experimental determination of the thermal conductivity coefficients λ of selected construction materials (clay, track ballast, fraction...

Estimation of Shear Stiffness of Interlayer Connection in Two-Layer Composite Beams Based on Analysis of Natural Frequencies

Zbigniew Perkowski, Mariusz Czabak, Karolina Gozarska

Communications - Scientific Letters of the University of Zilina 2013, 15(4):18-20 | DOI: 10.26552/com.C.2013.4.18-20  

The paper shows possibilities of testing composite two-layer beams with flexible connectors (like bolts in steel-concrete beams and nails in wooden-concrete ones) offered by analysis of their natural frequencies. It enables an estimation of shear compliance for the interlayer connection if Young's moduli of layers are known thanks to finding the global minimum of function of errors between model and measured natural frequencies of beam. The considerations are illustrated by the results of our own laboratory-tests.

Beam-Column Resistance According to Slovak Standard and Eurocodes

Peter Janik, Josef Vican

Communications - Scientific Letters of the University of Zilina 2013, 15(4):21-26 | DOI: 10.26552/com.C.2013.4.21-26  

The article deals with the verification of resistance of torsionally restrained hot-rolled beam-columns of H or I cross-sectional shape and also of the perpendicular hollow cross-section subjected to the biaxial bending and axial compression. Results of analysis of the beam-column resistances according to methods of former STN 73 1401 [1] and the current STN EN 1993-1-1 [2] are compared with results of numerical approaches. The observed members are subjected to the normal force and to the transverse loads uniformly distributed along the length of both axes. The cross-sections of HEB 300, IPE 300 and RHS 300x200x10 were chosen to compare obtained results.

Analysis of the Impact of Microclimate in a Roof Space on a Gothic Truss Construction

Renata Korenkova, Peter Krusinsky, Peter Pisca

Communications - Scientific Letters of the University of Zilina 2013, 15(4):27-31 | DOI: 10.26552/com.C.2013.4.27-31  

The research in the field of historical trusses, carried out at the workplace of authors for a long time, is focused on monitoring and analysing microclimate with the aim of specifying environmental conditions that would be suitable for preservation of a historical structure for further generations. Currently, this investigation is running together with a blanket screening of historical trusses in Slovakia [1 and 2]. In each truss, there was recorded the general technical state as well as the way of ventilation in a roof space. To define the impact of microclimate in a roof space on the lifetime period and sustainability of a historical truss, long-term...

Design and Stability of Long Span Railway Arch Bridge

Josef Vican, Jozef Gocal, Jaroslav Odrobinak, Richard Hlinka

Communications - Scientific Letters of the University of Zilina 2013, 15(4):32-38 | DOI: 10.26552/com.C.2013.4.32-38  

The bow-string arch bridge across the Vah River was designed on the main Slovak railway line. Total length of the bridge is almost 451 m, while the lengths of two main spans are 124.8 m. To analyse behaviour of the bridge, spatial transformation model was developed using FEM software. The Eurocodes were applied for all verification procedures. Bridge global analysis and verification of arches against buckling is discussed in more detail. The variation of upper bracing system and its influence on out-of-plane buckling of the arches is presented. Together with an architecture point of view, a minimum load amplifier to reach the elastic instability αcr...

Appropriate Information System in Road Freight Transport Based on the Carriers' Requirements and Costs

Dusan Halaj, Stefania Semanova

Communications - Scientific Letters of the University of Zilina 2013, 15(4):39-43 | DOI: 10.26552/com.C.2013.4.39-43  

The article is focused on the carriers' requirements and costs of the information systems in road freight transport. Based on the carriers' requirements for information and services as well as the costs of individual information systems, a recommended system or a combination of information systems, which are the most advantageous for carriers, is proposed.

Option of Solid Pollutants Abatement in Flue Gas Path

Katarina Sulovcova, Jozef Jandacka

Communications - Scientific Letters of the University of Zilina 2013, 15(4):44-47 | DOI: 10.26552/com.C.2013.4.44-47  

Biomass combustion produces gaseous and solid pollution. Solid pollutants are small particles which are getting into the air with smoke and may be harmful to the environment, the human and animal health. Therefore, it is important to decrease their amount in the ambient atmosphere. Particulate matter sources are not only big combustion devices but also small combustion devices which are quite common and widely used. It is necessary to mention that the small boilers are not as monitored as bigger ones. Therefore, they are potentially a large source of pollution. The main objective of this work is to reduce particulate matter concentration produced by...

Survey of Device Calibration Techniques for Fingerprinting Localization Algorithms

Juraj Machaj, Peter Brida

Communications - Scientific Letters of the University of Zilina 2013, 15(4):48-53 | DOI: 10.26552/com.C.2013.4.48-53  

In the paper device calibration algorithms for indoor positioning systems based on fingerprinting localization framework are discussed and compared. Device calibration should play important role in development of localization systems based on Wi-Fi since heterogeneous devices have different receiver parameters. This fact causes that the positioning system cannot provide position estimates with sufficient accuracy. In this paper different calibration approaches will be described and two state of art automatic calibration techniques will be compared in the simulations.

The Structure and Mechanical Properties of Domex 700 MC Steel

Magdalena Mazur, Robert Ulewicz, Frantisek Novy, Pawel Szataniak

Communications - Scientific Letters of the University of Zilina 2013, 15(4):54-57 | DOI: 10.26552/com.C.2013.4.54-57  

Nowadays fine-grained, quench and tempered steels are more and more used in design of modern semitrailers constructions. High mechanical properties and durability of this type of steel are its advantage. This paper summarizes the results of research together with the data available by the manufacturer SSAB company. The combination of the special features provided by this material enables construction of lighter semitrailer's components, which would result in a semiauto with a lower weight of its own. This paper presents the results of mechanical properties of Domex 700 MC steel.

Modelling Vulnerability of Transportation Network Using Influence Diagrams

Michal Titko, Adam Zagorecki

Communications - Scientific Letters of the University of Zilina 2013, 15(4):58-62 | DOI: 10.26552/com.C.2013.4.58-62  

The transportation network (TN) is important to serve the national priorities such as economic sustainability and growth, but it as well plays important role in disaster management and is subject to hazards. The understanding of the TN resilience and vulnerabilities is important for the national security. In this work we focus on the notion of TN vulnerability. We propose the use of a decision-theoretic approach based on Influence Diagrams (IDs). We argue that the use of IDs (1) provides an improved framework for risk assessment through more elaborate combining probabilities and consequences, and (2) facilitates knowledge elicitation from human experts...

Identification of the Main Problems in Using Cooperative Management in Slovak Enterprises and the Proposal of Convenient Recommendations

Josef Vodak, Jakub Soviar, Viliam Lendel

Communications - Scientific Letters of the University of Zilina 2013, 15(4):63-67 | DOI: 10.26552/com.C.2013.4.63-67  

The main purpose of the article is to present some knowledge in cooperative management focused on the area of management and marketing and to show possibility to use the cooperation in a company practice effectively. The article contains drafts for successful functioning of the cooperation in practice. There are also identified the main fields of potential problems which should be discussed by responsible participants within cooperation to achieve effective functioning. The solution of the questions researched within the article needs to use several methods depending on the character of particular parts of the solution.

Use of Correlation Analysis to Examine Relationship Between Tax Burden and Business Environment in Selected EU Countries

Magdalena Brezaniova

Communications - Scientific Letters of the University of Zilina 2013, 15(4):68-72 | DOI: 10.26552/com.C.2013.4.68-72  

The aim of the article is to examine the relationship between tax burden and business environment in Slovakia, Czech Republic and Germany. The examination is carried out using correlation analysis to identify the level of dependence between selected indicators of tax burden and number of business entities in selected countries. The article contains also analysis and comparison of found facts.

Computer Aided Simulation Analysis For Computation Of Modal Analysis Of The Freight Wagon

Pavol Stastniak, Jozef Harusinec

Communications - Scientific Letters of the University of Zilina 2013, 15(4):73-79 | DOI: 10.26552/com.C.2013.4.73-79  

This paper deals with theoretical and practical aspects of modal analysis, which belongs to the tests for design of new rail wagons. The paper describes the process for calculating the eigenfrequencies of the wagon with non-standard design and dimensions and strength analysis of the modified construction of bogie type Y25. This computer aided simulation analysis significantly reduces the time to verify the static and dynamic evaluation of rail vehicles.

3D Laser Scanning of Railway Line

Jana Izvoltova, Peter Pisca, Vladimir Kotka, Marian Mancovic

Communications - Scientific Letters of the University of Zilina 2013, 15(4):80-84 | DOI: 10.26552/com.C.2013.4.80-84  

3D laser scanning is very useful method to reach digital terrain model as the common output of map making. The paper deals with an application of 3D laser scanning in railway track measurements, which belong to the field of engineering surveying. Experimental measurements were carried out on the ballast-less railway construction with the purpose to determine its track geometry by the combination of terrestrial and laser scanning methods. Measurements were carried out in conformity with conditions involved in corresponding technical standards. Surveyors used a variety of firmware, CAD and mathematical software for laser scanning processing to reach...

Modelling Fire Severity and Evacuation in Tunnels

Vladimir Mozer

Communications - Scientific Letters of the University of Zilina 2013, 15(4):85-90 | DOI: 10.26552/com.C.2013.4.85-90  

Adequate design methods and tools are vital to any construction project, especially when its complexity and value are high. Tunnels, road or railway, are a good example of such structures. This paper deals with the topic of computer modelling utilization in the design and evaluation of fire safety in tunnels. The capabilities of selected software - Fire dynamics simulator + Evac - are demonstrated on a practical example - Tunnel Lucivna in the Slovak Republic. In this example case, both fire and evacuation modelling is used in conjunction to assess the overall fire safety of the tunnel. The results show the effects of fire on the tunnel structure as...

Sustainable Mobility In the city Of Bratislava - Tram Priority

Jan Fischer

Communications - Scientific Letters of the University of Zilina 2013, 15(4):91-95 | DOI: 10.26552/com.C.2013.4.91-95  

United Nations Development Programme (UNDP), acting as an implementing agency of the Global Environment Facility (GEF) implemented the project "Sustainable Mobility in the City of Bratislava". One component of the project deals with a higher level of priority to Bratislava's trams.Driving time information from the ITCS of Bratislava public transport operator was evaluated with Hamburg-Consults software "planfahrt" in order to find obstacles responsible for slowing down tram operation. Thereafter measures based on best practice solutions were introduced for a fast and reliable tram operation: "The tram stops at stations only".Integral part was the simulation...

Participative Management Style and its Relation to Employee Willingness to Accept Job Offer in the Same Company Once Again

Monika Rolkova

Communications - Scientific Letters of the University of Zilina 2013, 15(4):96-99 | DOI: 10.26552/com.C.2013.4.96-99  

Participative management style is based on the involvement of employees in decision-making and problem-solving in the company, as well as on supporting their high autonomy and own initiative. The article describes outcomes of the research which examines the interaction between the management style and willingness of employees to accept job offer in the current company once again if they were asked in the future. Results confirmed that there is highly significant correlation between the belief of employees they would accept the job offer in the same enterprise again and their satisfaction with current management style as well as use of the elements...