Volume 13 (2012): Issue 1 (January 2012)

Two technical regulations for capacity estimation of roundabouts are valid in the Slovak Republic at the present time. Each of these regulations is based on a different theory of capacity estimation which affects the outcome of the capacity of roundabouts and their evaluation. The capacity of various roundabouts was estimated according to both methods in the previous analysis made at our department [3] and in some cases different results of the evaluation were achieved. The question is: which one of the mentioned theories better reflects a real capacity of the roundabout? For this reason some of the existing roundabouts in the town Žilina were selected and they were evaluated according to both methods and a micro simulation using PTV Vissim software. The geometrical parameters of roundabout, real driving behaviour (speed, proportions, acceleration, etc.) and also pedestrian behaviour were taken into account in the microscopic models. The first assumption for capacity evaluation by a microscopic traffic model is a calibration process which is based on traffic surveys results. Thus created models allow several capacity analyses during the peak traffic loading. Then, the results of micro-simulation can be compared with the capacity evaluation according to the technical regulations. The article deals with creation and calibration of microscopic traffic models and with the mentioned comparing of results.

The problem of multi-criteria choice of alternatives with accounting the multiple stakeholders' preferences has been considered. The model for solution with the composition of fuzzy sets has been described. The mathematical formulation and justification of the solution using a fuzzy utility functions is given. Corresponding numerical calculations and graphic example are presented.

The focus of the research is the analysis and assessment of Air Traffic Control (ATC) maintenance and technical service processes. Deriving from the general ATC process model, which is the part of the Air Transport System, the related ATC Services including a Key Performance Indicator System were developed. A theoretical analysis was performed to develop a special correlation matrix between the Air Transport System to ATC service and ATC technical services, which reflect the top-down approach of process modelling proceeding. A particular research of different international ATC service organization, selected by defined parameter was performed for analysis. The analysis was implemented with different scientific research methods. Basing on this international research, a detailed SWOT analysis and conclusions of each ATC organization itself and additionally a parameter-oriented comparison between the different organizations and their specifics were performed. The results of this research were described in a SWOT analysis, rating assessment of utilization of the theoretical methods and qualified evaluation of implemented KPI System. For final maintenance process evaluation an ATC-Maintenance Process Maturity method based on ISO /IEC Standard 15504 was developed. The results and developments of the research will be the essential prerequisite for the further research of dissertation and development of a harmonized ATC Meta Frame Maintenance Process Model as a part of the Air Transport System on macro model level and deriving to the ATC specific Maintenance Service Model on micro level for the specific ATC organization basing on service and business modelling methods.

In the situation where a large increase in trade and freight transport volumes in the Baltic Sea Region (BSR) is expected and in which the BSR is facing a major economic restructuring, efforts to achieve more integrated and sustainable transport and communication links within the BSR are needed. One of these efforts is the development of logistics centres (LCs) and their networking, which will continue to have an impact on improving communication links, spatial planning practices and approaches, logistics chain development and the promotion of sustainable transport modes. These factors will reflect on logistics processes both in major gateway cities and in remote BSR areas.

The importance of logistics systems as a whole is not seen clearly enough. Logistics actors see that logistics operations are not appreciated as much as other fields of activity. In addition, logistics centres and the importance of logistics activities to the business life of areas and the employment rate should be brought up better.

In the paper main goal and tasks of national approach for LCs development are discussed. Strategic focus of new activities in this area is on the integration of various networks within and between logistics centres in order to improve and develop the quality of logistics networks as well as to spatially widen the networking activities.

The most important factor affecting the quality of transportation heavy goods is safety and security. Risk evaluation and management is one of the key issues during the planning oversized goods safe transportation and investments into transport infrastructure reconstruction. Usually it is international transportation and decision-making requires through analysis of the problem both, on the national and international scale and only then the most rational decision (transportation route) can be made with the view of the effective risk lowering, i.e. seeking the last possible reconstruction costs. The objective of the risk evaluation when investing into infrastructure reconstruction is to safeguard heavyweight or oversized goods transportation. When making the quantitative and economic assessment of the risk the theory of chances and mathematic statistics are most commonly used methods, because they are denoted to describe an event or process in case of ambiguous possibilities.

In present paper the authors consider the complete statements of initial-boundary problems for the modelling of various aspects of aqueous (3 models) and atmospheric systems (2 models) in Latvia. All the proposed models are described in terms of differential equations theory (using both ordinary differential equations and partial differential equations) and are regarded to be the evolutional models. Two of the three aqueous system models being studied are intended to describe the natural aquatic media ecosystems while the other models are aimed at studying environmental pollution processes.

This article primarily deals with identification of postal items and transport units in the logistic chain of postal operators. Nowadays, the identification is carried through barcodes and optical character recognition. In this article we would like to specify, how the transport units can be identified in the transmission process by RFID technology. In the carriage of postal items it is necessary to decide what type of transport is used for that purpose, what the flows of items are and what their intensity is. The RFID technology is complex, combining a number of different computing and communication technologies to achieve the desired objectives. Each object, which has to be identified, is stuck inside of a small object known as an RFID tag. RFID tag has a unique identifier, through which you can store additional information about the object. Equipments which are known under the name of RFID readers wirelessly, communicate with RFID tags with a view to identify RFID tags attached as well as the possibility to read and update information stored in the RFID label.

The article describes the scheme of the transport process, including planned technology and there is also simulated a real postal process in conditions close to operational.