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Ismar H.,University of Sarajevo | Burzic Z.,Military Technical Institute | Kapor N.J.,University of Belgrade | Kokelj T.,University of Defence
Strojniski Vestnik/Journal of Mechanical Engineering | Year: 2012

Material toughness becomes more significant material mechanical property, as well as design variable with recent advances of fracture mechanics understanding. Also, toughness is a particularly important parameter for novel structural materials such as high-strength steels. Furthermore, due to the fact that high-strength steels are mainly used in various welded structures, evaluation of welded joint mismatched properties, including toughness, become particularly important. Therefore, the following paper presents investigation results of impact and quasi-static toughness distribution and mismatch on high-strength steels welds. Welded joint's characteristic heterogeneous zones are obtained by mean of real welding and welding simulation. Finally, relation terms between various mechanical properties, including toughness, for further simplified engineering prediction are provided. © 2012 Journal of Mechanical Engineering. All rights reserved. Source

Jakovljevic M.,University of Kragujevac | Rankovic A.,University of Kragujevac | Rancic N.,University of Defence | Jovanovic M.,University of Kragujevac | And 3 more authors.
Value in Health Regional Issues | Year: 2013

Objective: Assessment of costs matrix and patterns of prescribing of radiology diagnostic, radiation therapy, nuclear medicine, and interventional radiology services. Another aim of the study was insight into drivers of inappropriate resource allocation. Methods: An in-depth, retrospective bottom-up trend analysis of services consumption patterns and expenses was conducted from the perspective of third-party payer, for 205,576 inpatients of a large tertiary care university hospital in Serbia (1,293 beds) from 2007 to 2010. Results: A total of 20,117 patients in 2007, 17,436 in 2008, 19,996 in 2009, and 17,579 in 2010 were radiologically examined, who consumed services valued at €2,713,573.99 in 2007, €4,529,387.36 in 2008, €5,388,585.15 in -2009, and €5,556,341.35 in 2010. Conclusions: The macroeconomic crisis worldwide and consecutive health policy measures caused a drop in health care services diversity offered in some areas in the period 2008 to 2009. In spite of this, in total it increased during the time span observed. The total cost of services increased because of a rise in overall consumption and population morbidity. An average radiologically examined patient got one frontal chest graph, each 7th patient got an abdomen ultrasound examination, each 19th patient got a computed tomography endocranium check, and each 25th patient got a head nuclear magnetic resonance. Findings confirm irrational prescribing of diagnostic procedures and necessities of cutting costs. The consumption patterns noticed should provide an important momentum for policymakers to intervene and ensure higher adherence to guidelines by clinicians. © 2013 International Society for Pharmacoeconomics and Outcomes Research (ISPOR). Source

Pamucar D.,University of Defence | Atanaskovic P.,University of Novi Sad | Milicic M.,University of Novi Sad
Tehnicki Vjesnik | Year: 2015

The railway level crossings (RLCs), places where a railway line and road cross each other at the same level, are considered to be potentially dangerous points for all traffic participants. In general, level crossings may be fitted with automatic and/or mechanically-operated signaling/interlocking systems (RLCsAO) that allow passing of trains by lowering the barrier for the road users. In addition, there are also RLCs provided only with traffic signs and related inventory that have no barriers at all (RLCsNO). Protection of these level crossings by introducing the automatic signaling/interlocking system (AO) calls for significant investments considering the fact that equipment required for RLC modernization is very expensive, not to mention the great number of RLCsNO planned for improvement. Therefore it cannot be expected all level crossings without barriers (RLCsNO) to be upgraded at the same time so as traffic safety level can be properly increased. The method to be followed when choosing which RLC is to be provided with the adequate safety equipment depends on certain criteria relevant for making the proper investment decision. The paper herein deals with modeling of fuzzy logic-based approach that will offer adequate support to management when prioritizing RLCsNO to be provided with automatic signaling/interlocking system (AO). Seven (7) criteria that may affect the investment decision have been identified. The experience-based knowledge of managers (experts) was transferred into the fuzzy logic rule-based system to create the unique knowledge base to be used for making decision on investment priorities (list of RLC according to priorities). The output is a criterion function value that may be applied to any RLC analyzed. Based on the obtained value of the criterion function, RLCsNO are classified in line with investment priorities. The paper also shows a research that covered 88 RLCsNO planned for upgrading on the territory of the City of Belgrade out of which only 25 were nominated for investment due to limited financial resources. © 2015, Strojarski Facultet. All rights reserved. Source

Burita L.,University of Defence at Brno | Burita L.,Tomas Bata University in Zlin | Hruza P.,University of Defence
2013 Military Communications and Information Systems Conference, MCC 2013 | Year: 2013

The paper describes the creation of the Knowledge Management System (KMS) based on Lessons Learned documents that were prepared at the Institute of Doctrine of the Military Academy. The objective of the KMS is to provide an access to the available information for the preparation of troops for foreign missions in a user-friendly way. The paper presents the research methodology, the analysis of the documents, the creation of ontology and the KMS development. One of the requirements for the solution was the implementation of the batch information input and the automation of the information context creation. © 2013 Military University of Technology. Source

Peric S.,University of Defence | Peric S.,University of Belgrade | Nedic B.,University of Kragujevac | Trifkovic D.,University of Defence | Vuruna M.,University of Defence
Strojniski Vestnik/Journal of Mechanical Engineering | Year: 2013

During the past few decades, special attention has been devoted to developing modern instruments and methods of monitoring the tribomechanical characteristics of technical systems. Today, various physical, chemical and tribological methods are used in tribomechanical systems diagnosis. Scientific experience in technical system exploitation and maintenance has shown that the most effective way to predict failure is based on parameters that are reliable indicators of wear. Analysis of oil samples, which contain particles due to the wear process, enables an evaluation of the tribology condition of the system in the early phases of its use. This paper deals with tribological tests that are part of the oil analysis and are used to access the condition of the system. Furthermore, the results of experimental research on the tribological characteristics of the oil sampled from engines and gear transmissions of the vehicles (Mercedes O 345, PUCH 300GD and PINZGAUER 710M) are shown. All of these road vehicle were in regular use by the Serbian armed forces. The performed research has revealed some significant changes in the tribological characteristics of oil for engine and gear transmission lubrication.. These changes directly depend on the condition of the entire engine and transmission elements, i.e. depend on their functional characteristics. The presented method of oil analysis should contribute to an early detection of failures due to friction and wear processes in vehicle engines and reduce the need for preventive maintenance. © 2013 Journal of Mechanical Engineering. Source

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