Communications - Scientific Letters of the University of Zilina, 2016 (vol. 18), issue 3

Articles

Articles

Diagnostic Rule Mining Based on Artificial Immune System for a Case of Uneven Distribution of Classes in Sample

Sergey Subbotin, Andrii Oliinyk, Vitaly Levashenko, Elena Zaitseva

Communications - Scientific Letters of the University of Zilina 2016, 18(3):3-11 | DOI: 10.26552/com.C.2016.3.3-11  

The problem of development automation of classification rules synthesis on the basis of negative selection in the case of uneven distribution of classes in the sample is solved. The method for the synthesis of classification rules on the basis of negative selection in the case of uneven distribution of class instances of sample is proposed. This method uses a priori information about instances of all classes of the sample. The software implementing the proposed method is developed. Some experiments on the solution of practical problem of gas turbine air-engine blade diagnosis are conducted.

Min-Max Robust Emergency Service System Design

Jaroslav Janacek, Marek Kvet

Communications - Scientific Letters of the University of Zilina 2016, 18(3):12-18 | DOI: 10.26552/com.C.2016.3.12-18  

This paper deals with the emergency service system design using the weighted p-median problem formulation. In such systems, not only the disutility of an average user is minimized, but also the disutility of the worst situated users must be taken into account. To cope with both objectives, we suggest a composed method. In the first phase, the disutility of the worst situated user is minimized. The second phase is based on the min-sum approach to optimize the average user's disutility. To formulate the mathematical models, the radial approach is used mainly for its excellent performance characteristics. Within this paper, we concentrate on effective...

New Exact Iterative Method for the Capacitated Vehicle Routing Problem

Zuzana Borcinova, Stefan Pesko

Communications - Scientific Letters of the University of Zilina 2016, 18(3):19-21 | DOI: 10.26552/com.C.2016.3.19-21  

The aim of the Capacitated Vehicle Routing Problem is to find a set of minimum total cost routes for a fleet of capacitated vehicles, to serve a set of customers. This problem belongs into category of NP hard problems that can be exactly solved only for small instances. In this paper we propose an exact iterative method for the CVRP based on the solution of Mixed Linear Programming model, which is able to solve problem for relatively larger instances in acceptable computing time.

Mathematical Model for Charter Flights Planning at Airports with High Air Traffic Volume

Vojtech Graf, Dusan Teichmann, Michal Dorda

Communications - Scientific Letters of the University of Zilina 2016, 18(3):22-27 | DOI: 10.26552/com.C.2016.3.22-27  

The article is devoted to a problem of flight timetable planning for charter airlines if air transport is operated at airports with high air traffic volume. It is typical for such airports that air transport is subject to time slots. That means aircraft can take-off or land only in given time intervals. A suitable tool for solving such type of the task is linear programming which has been successfully employed for planning in other transport systems. In the article a mathematical model which is able to plan a flight timetable for a given set of flights is presented.

Customer Capital as a Key Factor of E-Commerce Market Development

Dalibor Gottwald, Libor Svadlenka, Hana Pavlisova

Communications - Scientific Letters of the University of Zilina 2016, 18(3):28-33 | DOI: 10.26552/com.C.2016.3.28-33  

The importance of customer satisfaction has always been crucial to development of every single market in general. E-commerce market has gained importance during the last few years - especially in terms of annual turnover of e-commerce market. This trend is the result of changes in customer behavior. Increasing customer loyalty is one of the keys to business success. Active customer policy is necessary for the development of the market in individual states. The central point of the issue is to find concrete social constructs which can explain customer behavior in recent years. The main objective of the research is to define the area of selected variables...

Big vs Small Data in Micro and Small Companies

Zoran Cekerevac, Zdenek Dvorak, Ludmila Prigoda, Petar Cekerevac

Communications - Scientific Letters of the University of Zilina 2016, 18(3):34-40 | DOI: 10.26552/com.C.2016.3.34-40  

This article deals with the challenges that are faced by micro and small enterprises using data. After naming main hypotheses of the research, the attention is paid to definitions of big and small data and to their comparison. In the paper, analyses of the connections between big data and Internet are given. The main attention is paid to the use of big data in micro and small enterprises through the analyses of needed skills, organizational changes and big data management including possible pros and cons. As a special item, the analysis of risks and implementation is given. The analyses are supported with a lot of research results and numerous literature...

Ad Hoc Grid Resource Management: Grid Security

Slavomir Kavecky, Penka Martincova

Communications - Scientific Letters of the University of Zilina 2016, 18(3):41-49 | DOI: 10.26552/com.C.2016.3.41-49  

The purpose of security in ad hoc grid environments is to support secure execution of tasks on shared resources and to protect the resources from malicious user actions. The concept of trust management is capable to solve the security issues by incorporating trust into the process of decision making. The quality of the decisions is dependent on a correct assessment and representation of trustworthiness assigned to the potentially collaborating parties. In most cases the value of trustworthiness is derived at least from direct trust and recommendations, but other factors as risk, uncertainty, context dependent information and attributes characterizing...

Location Problems in Transportation Networks

Peter Czimmermann

Communications - Scientific Letters of the University of Zilina 2016, 18(3):50-53 | DOI: 10.26552/com.C.2016.3.50-53  

It is known that many optimisation problems on networks are NP-hard. However, it seems that the real transport networks have some interesting properties which allow us to find a "good" solution in reasonable time. In this paper, we suggest and study some new parameters of the transportation networks which could be useful in optimisation problems. We define the evenness and the robustness of the solution. We also concern ourselves with the statistical distribution of distances and edge values in transportation networks.

System Oriented Sustainable Supply Chain Management Innovations in Automotive Industry - Skoda Auto Case Study

Jiri Cee, Oleksii Dieiev, David Holman, Radim Lenort, David Stas, Pavel Wicher

Communications - Scientific Letters of the University of Zilina 2016, 18(3):54-59 | DOI: 10.26552/com.C.2016.3.54-59  

System thinking and system theory are currently widely used in a variety of subjects and fields. Sustainability Supply Chain Management is defined as the strategic, transparent integration and achievement of an organization's social, environmental, and economic goals. The automotive industry is known as one of the most competitive branches in the industrial sphere. Efficient and effective deliveries of complete cars are fundamentally dependent on the performance of the delivery concept in the whole supply chain. The aim of the article is to research and define the fundamental principles and assumptions of system oriented innovations utilized in the...

Elimination of Negative Impacts of Steel Scrap as a Charge Component during the Production of Synthetic Cast Iron

Peter Futas, Alena Pribulova, Jozef Petrik, Marcela Malindzakova, Andrea Rosova, Beata Grabowska

Communications - Scientific Letters of the University of Zilina 2016, 18(3):60-64 | DOI: 10.26552/com.C.2016.3.60-64  

The article presents the research results of omitting the steel scrap component from the production process of synthetic gray cast iron. The quality of synthetic iron produced in electric induction furnaces (EIF) is influenced by numerous factors. Its characteristic attributes are high values of mechanical properties (Rm, HB), but also its tendency to form chill out and shrinkages, foundry stress and sensitivity to hardness change at different casting wall thicknesses. Possibilities of offsetting and eliminating such negative effects were tested by introducing metallurgical countermeasures based on the properties of flake graphite alloys.

Assessment of Dynamic Parameters of Rail Fastening

Jaroslav Smutny, Lubos Pazdera, Vladimir Tomandl, Herbert Seelmann

Communications - Scientific Letters of the University of Zilina 2016, 18(3):65-70 | DOI: 10.26552/com.C.2016.3.65-70  

The paper is devoted to the analysis and comparison of the dynamic parameters of the rail fastening used in a standard way in the core railway network of the Czech Republic, i.e. the elastic rail fastening Vossloh W 14 and Pandrol FC. The paper also includes the description of the measurement and evaluation method. The conclusion of the paper is devoted to recommendations for further measurement and practical applications.

Cutting Metal Sheet with a Punch with Internal Heating

Jan Moravec

Communications - Scientific Letters of the University of Zilina 2016, 18(3):71-77 | DOI: 10.26552/com.C.2016.3.71-77  

This paper describes issues related to the process of cutting with a punch with internal heating. The theoretical part explains the effects related to thermal expansion, conduction and transfer of heat in the body of punches. The experimental part refers to the design of a tool with an internally heated punch. Experimental results are summarised and the process is analysed in the discussion.

Material Analysis of Degraded Steam Turbine Rotor

Petr Jonsta, Irena lckova, Zdenek Jonsta, Roman Heide

Communications - Scientific Letters of the University of Zilina 2016, 18(3):78-82 | DOI: 10.26552/com.C.2016.3.78-82  

This article deals with structural, fractographic and non-destructive analysis of a defective rotor made of 26NiCrMoV14-5 steel and assessment of possible technological failures resulting in the occurrence of cracking and subsequent defects. Metallographic analysis of the microstructure and evaluation of the steel metallographic purity were executed, including analysis of inclusions present and ultrasonic testing. Attention was paid to fractographic analysis of fracture areas. Degradation possibilities were monitored in relation to technological failures. The aim was to elucidate the cause of the rotor defect hindering its operational use.

Reliability and Safety of Structural Elements in the Gigacycle Region of Loading

Frantisek Novy, Robert Ulewicz, Otakar Bokuvka, Libor Trsko, Jan Lago

Communications - Scientific Letters of the University of Zilina 2016, 18(3):83-87 | DOI: 10.26552/com.C.2016.3.83-87  

The authors of this paper, based on their own results, discuss fatigue properties of low-alloyed fine-grained steel STRENX 700MC obtained in the ultra-high-cycle region (gigacycle fatigue) with regard to the reliability and safety of structural elements. According to obtained data it is obvious that fatigue strength continuously decreases with increasing number of cycles to failure (in a range from N = 10(7) to N = 10(10) cycles). Fatigue limit σc determined usually at N = 2 × 10(6) / 10(7) cycles does not meet the requirements of reliability and safety of structural elements. Design of structural elements which will be working in the ultra-high-cycle...

Resource Reservation Schemes for Optical Burst Switching Networks

Michaela Solanska, Miroslav Markovic, Milan Dado

Communications - Scientific Letters of the University of Zilina 2016, 18(3):88-92 | DOI: 10.26552/com.C.2016.3.88-92  

Since the current optical communication networks are based on internet protocol and demands for transmission capacity and speed are growing, the optical burst switching presents the solution for future high-speed wavelength division multiplexing optical networks. In order to successfully transmit bursts over optical burst switching network, resource reservation schemes have to be implemented. According to the way of resource reservation, reservation schemes use one-way reservation or two-way reservation. The schemes with one-way reservation are used mainly for optical burst switching networks. The survey of one-way resource reservation schemes is presented....

The Need for Innovation of Security Education for Strengthening the Results of Traditional Teaching at Universities

Martina Vackova, Lucia Kovacova, Maria Kancirova, Peter Losonczi

Communications - Scientific Letters of the University of Zilina 2016, 18(3):93-97 | DOI: 10.26552/com.C.2016.3.93-97  

This article deals with security education and the possibilities of innovative methods application in this kind of education at universities. The continuous development of science and technology, as well as constantly changing social needs which are closely tied to the emergence of new security risks and threats, dynamically affect the entire system of education. Therefore, an urgent need for the implementation of these requirements arises. There is a need to address the number of key roles in the framework of security education in the spirit of innovation methods in order to improve teaching and, subsequently increase the efficiency of the process.

Religious Existentialism as a Countermeasure to Moralistic Therapeutic Deism

Katarina Valcova, Martina Pavlikova, Marie Roubalova

Communications - Scientific Letters of the University of Zilina 2016, 18(3):98-104 | DOI: 10.26552/com.C.2016.3.98-104  

Moralistic Therapeutic Deism (MTD) is a new spiritual trend that is increasingly changing the religious landscape of in the Euro-American cultural provenience. Though appealing to the generation of 'emerging adults' (age 18-25), MTD results in undesirable life-outcomes that prompt religious scholars, theologians, and sociologists to carefully study its roots, expressions, and possible alternatives. Using S. Kierkegaard's religious existentialism as a case study, the authors argue that religious existentialism has the potential to face the detrimental effects of MTD and to reinvigorate stagnating religious communities.

Hybrid Analytical Performance Models of Parallel Computers

Peter Hanuliak, Michal Hanuliak

Communications - Scientific Letters of the University of Zilina 2016, 18(3):105-111 | DOI: 10.26552/com.C.2016.3.105-111  

The paper is a follow up to the performance modelling of dominant parallel computers (NOW, GRID) with analytical hybrid models (mixed) based on combinations of a more precisely developed corrected standard analytical model (M/M/1and M/M/m) and on an improved analytical model (M/D/1and M/D/m). Firstly, the paper briefly describes the steps of development of parallel computer architectures and then it summarises the basic concepts of performance evaluation. In the case of using SMP parallel system as node computer, the suggested models use for all the activities of node combinations of M/M/m and M/D/1 or M/D/m and M/M/1different (hybrid) queuing theory...