2009/15 Scientific papers, Series B
Permanentní URI k tomuto záznamuhttps://hdl.handle.net/10195/38186
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Článek Otevřený přístup peer-reviewedpublished On the drive dynamics of a 4WS-car(Univerzita Pardubice, 2009) Weiner, Martin; Tesař, MiroslavIn the article study of drive dynamics of a 4WS-car (Four-Wheel Steering) based on the one-track model is resumed. Attention was focused on three single problems. At solving equations both analytical and numerical techniques were applicated. To effect calculations and plot outputs the programming language Matlab was used.Článek Otevřený přístup peer-reviewedpublished Modeling of stress in the car half axle(Univerzita Pardubice, 2009) Bucha, Jozef; Turza, JozefThe article describes the procedure for stress determining in the parts of car axle. It is designed and described model, where used modern programs and methods of calculation, which allows monitoring the size and distribution of stress in the components of the vehicle axle when the vehicle ride through road bumps with different speeds. Road unevenness is generated according to ISO 8608, allowing easy quantification of quality of roads. The proposed model is universal. It can be used in other mechanical engineering fields.Článek Otevřený přístup peer-reviewedpublished Experimental measurement and simulation of harmonic frequency incurred from Czech railway network(Univerzita Pardubice, 2009) Rajský, František; Vejvodová, EvaThis paper deals with modeling and simulation of processes in the distribution network of electric energy. For the scope of this paper, the simulation means the simulation of quality of electric energy with the main focus on voltage and harmonic frequencies of current in distribution network. The point of connection of distribution network to the traction network was chosen as the point where measurements were taken and simulation was done. Introduction part deals with AC and DC traction network. Then the article discusses the problem of modeling of different parts of the distribution network and traction network, such as: overhead line, contact line, Filtration Compensation Equipment, twelve-pulse rectifier, three-phase three-wire transformer, traction transformer and load of railway tractive stock. The mathematical model of each part was drawn-up leading in a complex model of DC traction network connected to the 22 kV distribution network and the complex model of the one-phase AC traction network to the 110 kV distribution network. Software Pspice was employed to obtain simulations of particular components. Results of those simulations were compared with experimental measurements which were taken at the railway lap of traction current converter plant Hoštka – Mělník (for DC traction network) and at the railway lap of the traction sub-station Bohatice (for AC traction network). Based on comparision of measured and simulated data of AC and DC traction network it could be concluded that current harmonic frequencies take similar values, particular diferences are discussed in the paper. Another conclusion is that measeured and simulated data do not meet limits for harmonic frequencies of current given by standards PNE 33 3430 and ČSN IEC 61 000-3 -4. Limits for harmonic frequencies of voltage stated in the standard ČSN EN 50 160 ed.2 are not exceeded.Článek Otevřený přístup peer-reviewedpublished Transport system equilibrium(Univerzita Pardubice, 2009) Salava, Daniel; Švadlenka, LiborEquilibrium in transport system is problem integrating itself some important aspects. Economical aspect by setting of transport system equilibrium is one of key parts of investigated problem. It means especially investigation of mutually related influence of macroeconomical and transport system each other. Other sight on equilibrium solves marketing problem of interaction of market cathegories in transport, thus transport demand and supply. Of course, technical and traffic provision face of transport system for its efficiency has the same importance. It is necessary of course for its perfect function to hold also relevant and adequate capability of transport infrastructure. This side of problem comprises thus spatial aspect, and that is why it is important to consider also possibilities of solution of interregional transportations equilibrium and next problem solution in context of transport network equilibrium. Modelling of these partial problems is naturally based on relevant factors, which influence directly and importantly particular areas of equilibrium and consequently it is possible to reflect them by means of mathematical expression. Problems of transport system equilibrium cannot be solved strictly in complex form, because there exist some various aspects of its solution. Economical viewpoint by setting of transport system equilibrium is one of parts of this problem, but important role for transport system efficiency is put also on technical and operational capaticies of this system, which requires for its function necessary of course sufficient infrastructure as well. This contribution otherwise comprises in previous text in general model form just possible solutions of system equilibrium from spatial viewpoint, thus reflects equilibrium solution of interregional or multiregional transportations, and next problem solution in sense of equilibrium on transport network. Modelling of this partial problems naturally works on relevant factors, which influence directly and significantly particular areas of equilibrium and simultaneously it is possible to express them by mathematical methods. The main goal and focusion of this paper is identification of relation between macroeconomical and transport system on basis of appropriately selected representative variables and then mathematical modelling of them from viewpoint of their mutual equal - balance state. Mission of solution results is not only verification of assumptions of concrete interaction between both systems, but on the basis of gained results also assessment of transport mode subsystems role in sense of their contribution to macroeconomical system. By transport system equilibrium modelling in relation to macroeconomical system, concrete data are applied from those final equilibrium model of both systems is derived including verification of its validity by means of relevant mathematical methods. Solution, detection and understanding to problem of relations between macroeconomical and transport system is created by appropriately selected representative variables of both systems and choice of structure and kind of enter data, which are quartal data of real gross domestic product in fixed prices of 2000 year and of traffic volumes in personal kilometres and tonal kilometres of passenger and freight transport for particular transport modes. Identification of mutual relation between selected variables of macroeconomical and transport system provides correlational analysis of stochastical components of time series. Before it, adequate smoothing and adjusting of data must be processed with verification of validity of gained results from used technique for smoothing. In cases, when correlation analysis confirms close dependences, regressional modelling is processed from viewpoint of mutual equilibrial state of both systems. State of variable of one system can also impact other system with certain delay, and that is why the attention is devoted also to delayed correlations of mutually inverse dependences with various time shifts. Results of regressional modelling including models followed from delayed correlations are veryfied by testing methods for examinations of regressional parametres and rate of explanation of reality by models. Mission of solution results is not only verifiation of assumptions of concrete interactions between both systems, but also assessment of role of partial transport modes to their support of economical system with additional ideas of causes.Článek Otevřený přístup peer-reviewedpublished Analysis of logistic centers´external enviroment in CR(Univerzita Pardubice, 2009) Kampf, Rudolf; Roudná, JanaThe logistic centre operates economically in the specific geographical point. The external environment, which is constantly changing and evolving, should be taken into an account by selecting this point. The SLEPT analysis can be used for mapping the current situation of the external environment. This analysis deals with social, legal, economical, political and technological factors, which effect on the logistic centre. The single factors should be fully explored and estimated their future development during this analysis. However all the factors effect on the logistic centre simultaneously and that’s why their impact can’t be assessed in isolation. There are briefly outlined these factors in this paper.Článek Otevřený přístup peer-reviewed The use of AHP method in the investment activities of company(Univerzita Pardubice, 2009) Hruška, Roman; Průša, PetrThis article deals with method of AHP (Analytic Hierarchy Process). The method of AHP is a systematic method for comparing a list of objectives or alternatives. We can use this method in the investment activities of company. In our example our company proposes three different types of investment (new company information system, transport modernization and using of RFID (Radio Frequency Identification) technology in the company). The output of method of AHP is the determination of sequence of single investments according to their importance for the company.Článek Otevřený přístup peer-reviewedpublished Planning method of logistics-distribution processes in function of distribution chains(Univerzita Pardubice, 2009) Babić, Darko; Ivaković Babić, Morana; Průša, PetrThe logistic activities represent an optimized response to the globalization processes, and the companies involved in such activities, with optimal planning of the logistic and distribution processes, realize higher profit and more stable position on the world market. Therefore, it is necessary to define the logistic and distribution processes, their elements and interrelations, effects, as well as planning process methods, and all this in order to optimize the operation of logistic operators. Logistic-distribution processes are very complex, i.e. they consist of a multitude of details that occur in reality, but cannot influence the planning. Precisely therefore it is necessary to solve the real problems by simplified copies of these problems, the so-called models, as the basis for making a plan. The presentation of the real problem, the simplest possible but with all the necessary details and not ignoring several serious real factors, is called modelling (“art of model creation”). The basic aim of planning the logistic and distribution processes is to achieve the uniformity and consistency i.e. continuity of the goods flows and the best possible usage of the traffic infrastructure and the transport means. The above analysis of observation and research of logistics-distribution systems and its elements show that it is not possible to define the exact methods that could be applied in all cases, ie in the business of every company, so as to completely solve the problems that occur in logistic and distribution systems . Namely, different companies have different basic logistic and distribution priorities, regardless of what they all do business together in the logistic and distribution system. So as a result of the study lists a method that may be applicable in most cases, as a function of distribution channels, whose function is important in all businesses from the logistics sector.Článek Otevřený přístup peer-reviewedpublished Regional public passenger transport service in macroscopic transport models(Univerzita Pardubice, 2009) Bulíček, Josef; Mojžíš, VlastislavThe paper is focused on selected aspects of estimating of public passenger transport service in regional areas by macroscopic transport models. The transport is envisaged as transport flows in this kind of models, but the regional public passenger transport service mainly has got discrete character. The basic preconditions for solution of these questions are characterized in the paper. The main accent is put on the linear programming model for acquirement of integer values for OD matrices with preservation of proportions in OD matrices calculated by transport gravity model.Článek Otevřený přístup peer-reviewedpublished Assumption in development of intermodal transport systems(Univerzita Pardubice, 2009) Nachtigall, PetrPresented paper is an abstract of author’s dissertation thesis on theme The Assumptions in Development of Intermodal Transport Systems, which deals with trend this will be observed in the future on the field of intermodal transport in Czech Republic and EU. Its goal is in finding ways, how to make intermodal transport more attractive for wider spectrum of haulers. Dissertation thesis is divided into five main chapters. In the first chapter is a state-of-the-art analysis of intermodal transport in Czech Republic as well as in EU. Emphasis is placed on technological respect of intermodal transport and its specifics in confrontation with direct road transport. There is propounded a hypothesis that variable costs of intermodal transport including accompanied might be lower than for direct road transport. This hypothesis is supported by expected mathematical curve of variable costs for accompanied intermodal transport and direct road transport. Another important part of the analysis is focused subvention support of intermodal transport on national and European level. Matter of common disadvantage of intermodal transport is very high costs for infrastructure development and buying of vehicles. Those costs are shown up in final price of the service, so that most dynamic development has nowadays types of intermodal transport with less input costs. Presumption of dissertation thesis is, that if intermodal transport systems will be free of input costs, than intermodal transport can be profitability. The input costs can be financed from European funds or national donation. One of the conditions for European projects is sustainability after the end of subsidy, so in the field of variable costs.Článek Otevřený přístup peer-reviewedpublished The experiences with utilizing of public relations in the urban public transport systems(Univerzita Pardubice, 2009) Drdla, Pavel; Bulíček, JosefThe points of issue embodied in the paper are situated in the category of public relations in the firms and companies. All of mentioned facts are thematically steered into rarely examined public transport companies, especially into the part of them, into companies operating in urban public transport services. The research of the general points of issue of public relations is most enlarged in the English-speaking countries, how it follows from studying of information sources and literature. The research of public relations by public transport transporters is significant as well in other countries on the same level. The core of the paper is consisted of the experiences with public relations in the urban public transport systems in the Czech Republic and in the Slovak Republic. The experiences have been gained by the extensive survey in both of these states.