Articles
Vol. 24 No. 4 (2012)
Published on 25.07.2012
Krešimir Grilec, Gojko Marić, Katica Miloš
2012 (Vol 24), Issue 4
The requirements for weight reduction and improvement of performances in the design of transport means are often in contradiction to the requirements for increased safety. One of the possible ways of meeting these requirements is the application of metal foams. Thanks to cellular structure of aluminium foam along with low weight, the capability of noise and vibration damping, they feature also excellent capabilities of absorbing impact energy. Their application in the production of impact-sensitive elements of mobile or stationary transport means has significantly contributed to the reduction of the impact or collision consequences.
The focus of this paper is on improving the energy absorption characteristics of aluminium foams considering the significance of their application for the technology of traffic and transport.
The paper analyzes the influence of the chemical composition and density on the compression behaviour of aluminium foam. The aluminium foam samples were produced from Alulight precursor. The capability of samples to absorb mechanical energy has been estimated according to the results of compression tests. The tests were performed on a universal test machine. The test results showed that aluminium foams feature good energy absorption and the absorption capability decreases with the foam density. The Alulight AlMgSi 0.6 TiH2 - 0.4 foam can absorb more energy than Alulight AlSi 10 TiH2 – 0.8 foam.
Milan Janic, Tomislav Jovanović
2012 (Vol 24), Issue 4
This paper deals with estimating possible effects in terms of mitigating the social and environmental impacts which could be achieved by operating the rail freight train instead of the road truck services in the given Trans-European transport corridor during the specified period of time. In general, these impacts embrace noise, congestion, traffic incidents/accidents (Safety), and energy consumption and related GHG emissions (Greenhouse Gases). Each type of impact, specific to particular mode, is analyzed and modeled, thus enabling its quantitative estimation and intermodal comparison under the given circumstances. In particular, energy consumption and related GHG emissions and their costs have been under focus. The total costs of the above-mentioned impacts in the given case have also been estimated. Thus, they both represent a solid base for the assessment of the social-environmental feasibility of the future similar cases.
Goran Kos, Predrag Brlek, Igor Franolić
2012 (Vol 24), Issue 4
This study consists of the analysis of public passenger transport in Zadar County, that is, transport on the County and school lines and suggestions of transport rationalization. The rationalization comprises the application of the County and school lines integration, as well as suggestions of other measures which aim to reduce transport costs financed by Zadar County. The objectives to rationalize public passenger transport have been defined, all County transport lines of schoolchildren and other passengers have been analysed as well as actual deficiencies in the city, County and school transport needs. Road transport infrastructure, carriers and transportation vehicles have been analysed. The future transport demand has been reviewed and the prediction of passengers on lines has been provided. Within the next five to ten years no relevant changes will take place, meaning that the balance in transport supply and demand will not be disrupted significantly. This study presents the measures for transport cost reduction and increase in the safety level in the performance of public transport.
Valentina Radojičić, Goran Marković, Milan Janković, Borko Drašković
2012 (Vol 24), Issue 4
This paper proposes a modification of traffic forecast model generated by residential and small business (SOHO, Small Office Home Office) users. The model includes forecasted values of different relevant factors and competition on broadband market. It allows forecasting the number of users for various broadband technologies and interaction impact of long-standing technologies as well as the impact of the new technology entrant on the market. All the necessary parameters are evaluated for the Serbian broadband market. The long-term forecasted results of broadband traffic are given. The analyses and evaluations performed are important inputs for the transport network resources planning.
Igor Rudan, Pavao Komadina, Renato Ivče
2012 (Vol 24), Issue 4
International studies have determined a strong connection between maritime casualties and human error. Most of the studied effects of human factor on casualties in maritime transport are connected to individual ship crew member’s subjective approach to solving the problem. Therefore, the aim of this research was to determine the relationship between different subjective definitions of a near miss in situations of immediate danger of collision for different categories of examinees. The categories of officers and masters with regard to years of service, type of ship they are on board, ship’s size, etc., were considered. Over a period of four years the research was performed on officers and masters (N=234) that attended specialized courses (3 to 6 attendants) on navigation simulators of the Faculty of Maritime Studies in Rijeka. Based on the results obtained by nonparametric tests for small independent samples, certain significant differences with respect to differently defined divisions of the examinees were identified.
Zdravko Schauperl, Mladen Nikšić, Davor Kolednjak
2012 (Vol 24), Issue 4
The paper studies the influence of liquefied petroleum gas as alternative fuel on the condition of the internal combustion engine. The traffic, energy, economic and ecological influence as well as the types of fuel are studied and analyzed in an unbiased manner, objectively, and in detail, and the obtained results are compared with the condition of the engine of a vehicle powered by the stipulated fuel, petrol Eurosuper 95. The study was carried out on two identical passenger cars with one being fitted with gas installation. The obtained results show that properly installed gas installations in vehicles and the usage of LPG have no significant influence on the driving performances, but they affect significantly the ecological and economic parameters of using passenger cars.
Filip Taner, Ante Galić, Tonči Carić
2012 (Vol 24), Issue 4
This paper addresses the Vehicle Routing Problem with Time Windows (VRPTW) and shows that implementing algorithms for solving various instances of VRPs can significantly reduce transportation costs that occur during the delivery process. Two metaheuristic algorithms were developed for solving VRPTW: Simulated Annealing and Iterated Local Search. Both algorithms generate initial feasible solution using constructive heuristics and use operators and various strategies for an iterative improvement. The algorithms were tested on Solomon’s benchmark problems and real world vehicle routing problems with time windows. In total, 44 real world problems were optimized in the case study using described algorithms. Obtained results showed that the same distribution task can be accomplished with savings up to 40% in the total travelled distance and that manually constructed routes are very ineffective.
Edvard Tijan, Adrijana Agatić, Bojan Hlača
2012 (Vol 24), Issue 4
The paper researches the necessity and requirements for Port Community System (PCS) implementation in Croatian seaport clusters. The authors define the Port Community and analyze the basic features of seaport clusters and Port Community Members (PCM). The most important documents in seaport operations are identified and analyzed. The role of Port Authority as the most important factor of PCS implementation in the Croatian seaports is defined. The Seaport Information and Communication Technology (ICT) systems are defined and analyzed, and phases of ICT integration in Port Community are determined, along with the current status of the Croatian seaports regarding ICT integration. The potential benefits of PCS implementation in the Croatian seaports are stressed. Finally, a definite need for PCS implementation is determined, in order to achieve and maintain the Croatian seaport competitiveness in global maritime transport industry.