Communications - Scientific Letters of the University of Zilina, 2006 (vol. 8), issue 3
Articles
Management of Street Routing Problems Using Decision Support System
Peter Matis
Communications - Scientific Letters of the University of Zilina 2006, 8(3):5-8 | DOI: 10.26552/com.C.2006.3.5-8 
Servicing a large number of customers in a city zone is often a part of many logistics chains. The capacity of one delivery vehicle is limited, and at the same time, it usually serves a large number of customers. These problems are NP hard and often called a Street Routing Problem (SRP). Problems of this category are similar to the problems named as Vehicle Routing Problem (VRP). In this paper, these problems are explored and potential solution paths for their management are described. As presented in the paper, the management of street routing problems could be effectively done only by using decision support systems or other informatics systems, such...
A Time Limited Vehicle Routing Problem
Jan Pelikan
Communications - Scientific Letters of the University of Zilina 2006, 8(3):9-11 | DOI: 10.26552/com.C.2006.3.9-11
A vehicle routing problem is a classical problem in operation research consisting in delivery routes optimization in communications network containing depot of all routes and a given number of cities, which is necessary to include in delivery routes. The demand of all cities is given and the condition is that the sum of demands of the cities on the route should be less or equal to the capacity of a vehicle.The paper deals with a modification of the vehicle routing problem in which the capacity of a vehicle is not limited but the times of pickup to all cities are limited by a given value. A similar problem and model can be formulated for optimization...
Cost Reduction by Means of Alternative Solutions
Zsolt Tibor Kosztyan, Zoltan Perjes, Andrea Bencsik
Communications - Scientific Letters of the University of Zilina 2006, 8(3):12-16 | DOI: 10.26552/com.C.2006.3.12-16
In some projects the offered remuneration is lower than the estimated total costs. There are three possibilities to handle this problem. The first two is either to resign from the implementation, or to accept it knowing that we will loose money, but can regain it later in another project. In this latter case we have to determine the optimal resource allocation with minimal total cost. In the scheduling phase we can use some cost minimizing method. After that we can determine the lower and the upper bound of the start time of the activities. The next step is to determine a feasible solution and then the optimal resource allocation. The third possibility...
On a Certain Transport Scheduling Problem for Heterogeneous Bus Fleet
Peter Czimmermann
Communications - Scientific Letters of the University of Zilina 2006, 8(3):17-18 | DOI: 10.26552/com.C.2006.3.17-18
In this paper we consider a certain transport scheduling problem for heterogeneous bus fleet. We suppose that some restrictions are given for sets of vehicles and trips. We study some special cases of this problem that can be solved in polynomial time.
Lagrangean Relaxation Based Approximate Approach to the Capacitated Location Problem
Jaroslav Janacek, Lydia Gabrisova
Communications - Scientific Letters of the University of Zilina 2006, 8(3):19-24 | DOI: 10.26552/com.C.2006.3.19-24
When a distribution system is to be designed, limits on terminal capability often must be taken into account. These capacity constraints in this and other facility location problems constitute severe obstacles in exact solving processes. Within this paper, we focused on study of approximate methods based on Lagrangean relaxation of the capacity constraints, which has several advantageous properties. The first of them is that the relaxed problem, known as the uncapacitated location problem, can be solved exactly even for real sized instances [6], [4]. The second useful property of the Lagrangean relaxation is that the objective function value of the...
Combinatorial Auctions for Selling Network Capacity
Petr Fiala
Communications - Scientific Letters of the University of Zilina 2006, 8(3):25-28 | DOI: 10.26552/com.C.2006.3.25-28
The network economy is a term for today's global relationship among economic subjects characterized by massive connectivity. Today's network systems provide the infrastructure and foundation for the functioning of societies and economies. They come in many forms and include physical networks such as transportation and logistical networks, communication networks, energy networks, as well as more abstract networks as economic, financial, social, and knowledge networks. The paper presents modeling of auctions in network economy. Auctions are important market mechanisms for the allocation of goods and services. Combinatorial auctions are those auctions...
Mathematics in Applied Informatics Education - New Choices and Challenges
Michal Kaukic
Communications - Scientific Letters of the University of Zilina 2006, 8(3):29-32 | DOI: 10.26552/com.C.2006.3.29-32
In this paper, new ways of teaching Mathematics, which have been opened by the widespread of computers and notebooks and also by adequate software tools, are discussed. Based on our experience, we advocate the use of Open Source software as the mainstream tools in Mathematics and Informatics education. We give the more concrete examples of tools, used for teaching of Numerical Analysis topics, which can be successfully explored also for majority of other subjects in Applied Informatics and Mathematics. Some recommendations for the choices of suitable software and for further coordination in this field are given.
Feature Extraction Using Pulse-Coupled Neural Network in Isolated Speech Recognition
Matus Jurecka
Communications - Scientific Letters of the University of Zilina 2006, 8(3):33-36 | DOI: 10.26552/com.C.2006.3.33-36
This article presents achieved results concerning an feature extraction in isolated speech recognition problem using the Pulse-Coupled Neural Network (PCNN) approach. PCNN based feature extraction is analyzed for a direct Pulse Coded Modulation (PCM) input and a Fast Fourier Transform (FFT) coefficients input.
Choosing the Right Type and Location of the City Public Transport Stops
Ivana Olivkova
Communications - Scientific Letters of the University of Zilina 2006, 8(3):37-41 | DOI: 10.26552/com.C.2006.3.37-41
This paper is concerned to tram stop safety in the Czech Republic. Recently some experimental solutions of tram stops (with alternative successes) have been realized in Prague and Brno. These experimental solutions of tram stops, which very often emerged as trial and error, were based on elevated carriageways. Due to the fact that there is lack of qualified information and projection recommendations, I would like to present the selection of information based on real operation experience. The paper has been compiled using results of the grant project No. 103/04/0476 "Proposal of financing traffic attendance methodology", which is being realised thanks...
Quality of Front-Line Work = Human Resource Management?
Andrea Bencsik, Judit Feher
Communications - Scientific Letters of the University of Zilina 2006, 8(3):42-47 | DOI: 10.26552/com.C.2006.3.42-47
"Good quality" human resource management is a source of competitive advantage for companies in the field of personal services, especially in customer service.Customers' opinion of overall service quality is very much influenced by the impression, when they encounter front-line staff. HR management can be regarded as "good quality" if it is able to ensure that staff members working on the front line are professionally and emotionally well-prepared, and committed. It can only perform its function if it is able to adopt a new approach. As an internal service provider it strives to support workers in both meeting corporate requirements and achieving their...
Time-Temperature Curve Definition According to Fuel Type
Milan Dj. Blagojevich
Communications - Scientific Letters of the University of Zilina 2006, 8(3):48-51 | DOI: 10.26552/com.C.2006.3.48-51
An idealized temperature curve of compartment fire has three, distinct phases: growth phase - development phase from ignition to flashover, steady-burning phase, and decay phase. The experimental results performed in recent years show that the standard temperature curve proposed by the International Standards Organization (ISO) as well as ASTM E119 time-temperature curve selected for a standard fire resistance test do not satisfactorily describe fire phases for different fuel types. In this paper we propose the definition of the time-temperature curve by means of a unique function in which the fuel type is defined with parameters.
Domains of Safety
Jerzy M. Wolanin
Communications - Scientific Letters of the University of Zilina 2006, 8(3):52-53 | DOI: 10.26552/com.C.2006.3.52-53
It is considered that providing safety in universal dimension is exclusively responsibility of a public authority and the authority is fully responsible for efficient implementation of systems concerned with it. In reality, there is no prospect of not having incidents and therefore, there is no absolute safety. If such ideas exist anywhere, they are only theoretical concepts. Safety is a condition of the surroundings and natural environment of a local community. The condition level is defined by the degree of existing risk in that community. The risk is ubiquitous and inevitable as it exists in nature and civilian space. So the local governing body...