Logistics and Transport (E-Journal)
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Optimisation of Railway Polynomial Transition Curves with Different Number of Terms
Get PDFThis paper presents the results of research of influence of degree and number of polynomial terms of railway transition curves (TCs) on their dynamical properties. The research performed for needs of this work are planned numeric tests. The search for the proper shape means the evaluation of the curve properties based on chosen dynamical quantity and generation of such shape with the use of mathematically understood optimisation methods.For the needs of this work advanced vehicle model, dynamical track - vehicle and vehicle - passenger interactions as well as optimisation methods were exploited. The subject of the analysis are odd degree polynomial transition curves of the 5th, 7th, 9th and 11th degree. For each degree of the polynomial a range of acceptable number of polynomial terms was determined. One dynamical quantity - minimum of integral of vehicle body lateral acceleration - being the results of simulation of railway vehicle advanced model is exploited in the determination of quality function (QF)
Multiscale Modelling in Railway Engineering
Get PDFThe article presents the design and operation of selected types of physical simulation models of the railway track subgrade and transport earthen structures. These models include:- model section of railway track for testing vertical displacements,- test bench physical simulation models of reinforced railway track subgrade,- multiscale physical simulation model of the retaining wall made of reinforced ground stabilizing the transport embankment,The paper discusses the research of the displacement state of the models constructed. The results of research can be the foundation for designing subgrade reinforcements in modernised railway tracks
Using Diagnostic Information for Planning an Energy-Optimal Path of an Autonomous Vehicle
Get PDFThe article has presented a general idea for an algorithm that would allow for determining the optimal parameters of vehicle movement. The sources of energy dissipation have been assumed as follows: damage to the engine and the drive. In addition, the mathematical basis have been presented for assessing the impact of damage resulting from problems such as axial misalignment on the dissipated energy. In the second part of the paper, the concept of the algorithm has been detailed, paying special attention to certain problems that have arisen, and an algorithm has been proposed that determines the optimal movement parameters for a simplified case, when the vehicle is moving along a path determined in advance. In addition, the results of applying the algorithm for a simple case have been presented, as well as the impact of the particular energy dissipation parameters of the model on the optimal velocity profile of the vehicle. The plans for further research include estimating the impact of other damages, such as damaged bearings or demagnetising, on the energy dissipation. Further work on an algorithm is also planned that would allow for simultaneous determining of an optimal path as well as an optimal velocity profile
Risk Management in Logistics Enterprises: Findings from the 2013 Empirical Study
Get PDFRecent developments and events – e.g. trend to globalization, outsourcing activities, shorter life time cycles, but also natural disasters and others – have led to the increase of risks in business. Furthermore, regional and global financial and economic crises have brought additional and often unexpected risks into business. Therefore, risk management has been identified as one of the important management tasks supporting a company in reaching its objectives. In many countries, implementation and use of risk management is required by law. In Germany, the so - called KonTraG (Corporate Sector Supervision and Transparency Act) prescribes risk management for all incorporated companies.Although there is no mandated risk management for other legal forms of organizations, the KonTraG has also impact on those forms of organizations, especially on attestation by external auditors.This paper focuses on the industrial sector of logistics service providers (LSPs). The logistics service industry in Germany is a fragmented market. Although there are some ‘big players’, i.e. large LSPs, that are involved in national and international logistics activities, there also exists a large number of small and medium - sized enterprises (SMEs).For those small and medium - sized LSPs, risk management is not compulsory. Nevertheless, they face at least the same risks as the big players – if not even more (e.g. due to smaller market shares and lower market power).There is a number of questions involved with risk management in logistics enterprises: Is risk management an approach used by LSPs – and to what extend? Who initiates risk management in logistics enterprises? What is the degree of maturity of risk management in the logistics industry? What tools and methods are used by LSPs? Are companies evaluating risk management as beneficial?Not much research has been conducted in the logistics service industry so far. Thus, to answer those questions, the authors started to conduct a first empirical study in 2008. This study was followed by a second field study in 2011, i.e. directly after the first global financial and economic crisis. In 2013, the authors carried out the third empirical study on the status of risk management in logistics enterprises in Germany. The study allows for both stating the current status of risk management and identifying developments and trends in the logistics industry related to risk management.This paper intends to highlight the most important findings from the 2013 field study and to evaluate the status quo of risk management in logistics enterprises. It also specifies room for improvement to reach a higher degree of professionalism in risk management in the logistics industry
Challenges of Aviation Personnel Training at Higher Educational Institutions
Get PDFThe Ukrainian airlines’ fleet consists of civil aircrafts, 80 percents of which are manufactured abroad, in particular in the United States of America and in Western Europe. That is why it requires training of aviation specialists who perform maintenance operations of foreign and national modern aircrafts in accordance with the international standards. Principal aspects of national educational standards for aircrafts maintenance personnel training harmonization with EASA Regulations have been analyzed to show how to adjust the educational and training programs and curricula for training of aircrafts maintenance personnel according to Part-66 standards
The Importance of Logistics in Creating Entrepreneurial Network Structures
Get PDFBuilding entrepreneurial companies is associated with taking actions to enable their general development, leading to application of innovative solutions, both in technology and management. Modern economy and pervasive crisis force entrepreneurs to search for alternative means for supporting the progress in order to be able to fight for customers against ‘foreign countries of cheaper production’ and, at the same time, to not being forced to use "drastic" methods of reducing production costs. This paper presents the already existing solutions that are not fully used in Polish reality, which are the network structures (clusters) that have beneficial economic impact and build integrated supply chains. The author is taking a theoretical attempt to connect concept of supply chains and clusters. Consolidation will relieve the individual companies and thereby will create opportunities to take new - common – actions, which together will create entrepreneurial network structure and bring individual benefits
Educational Tasks of Logistics in the Knowledge-Based Economy
Get PDFThe aim of the article is to present adaptation of logistics information technology to the state's needs in the knowledge based society. This subject is closely linked to energy management, which must include power generation development models in countries. The essence of the presented considerations is to trigger changes in the reconstruction of the energy infrastructure - activate the PROSUMER value chai
New Technologies in the Global Aero - Space Engineering Education
Get PDFNew technologies in the global aero - space engineering education are considered. The paper paid special attention to the civil aviation hazards and risks in the context of global aviation development trends. The paper deals with challenges of new aviation specialties creation, including features of 1, 2 and 3 education cycles. The paper introduces practical experience of the National Aviation University according to the new technologies in the aero - space engineering education implementation
