Kutin M.,Institut Gosa |
Adamovic Z.,Technical Faculty
Russian Journal of Nondestructive Testing | Year: 2010
The paper shows the results obtained in the comparative testing of the welded joints using conventional methods and thermography. The testing aim, using specimen tension of butt welded joint for S 355J2G3 steel (removed from the parts of lug assembly of dredger anchor steel-wire rope Sch Rs 1760/5 × 32) was to determine the tensile features of welded joint by introducing the load transversally to the welded joint. The temperature changes on the tested sample were continuously recorded by thermography, providing to predict attaining the critical stresses, which cause the appearance of fissures, that is, to define the criteria on determining the maximum sample temperature alteration in the field of the elastic and elastoplastic strains. © Pleiades Publishing, Ltd., 2010.
Rankovic A.,Technical Faculty |
Saric A.T.,University of Novi Sad
15th International Power Electronics and Motion Control Conference and Exposition, EPE-PEMC 2012 ECCE Europe | Year: 2012
This paper proposes an algorithm for distribution state estimation with included unmonitored (or partially monitored) photovoltaic generation and wind turbine&asynchronous generator based models, as well as distributed loads. These data are treated as pseudo measurements and included in the state estimation with lower weights. Initial state estimations for unmonitored (partially monitored) distributed generation and loads are calculated from the weather forecast data or daily load profiles, respectively. The pseudo measurements are additionally re-adjusted by the optimal load/generation reallocation procedure to fit the real-time measurements inside the weighted least square (WLS) based state estimation algorithm. The results and practical aspects of the proposed methodology are demonstrated on characteristic real-life urban distribution network with 40 buses. © 2012 IEEE.
Petrovic P.B.,Technical Faculty
Measurement Techniques | Year: 2013
A new method of measuring active power and the effective (root mean square) value of alternating signals in half the time required by other existing methods, is proposed. The measurement is made by simple summation of samples of the instantaneous power without adjusting the measurement time depending on the signal frequency. Mathematical modeling enables the accuracy of the proposed algorithm to be estimated. © 2013 Springer Science+Business Media New York.
Stojkovic S.,Technical Faculty
International Journal of Electrical Engineering Education | Year: 2011
The paper presents a simulation model of the three final spans and one 110/35/10 kV/kV/ kV distribution transformer substation (TS) bay. In order to demonstrate the insulation coordination procedure to students, we used this model to provide simulations of backflash and propagation of travelling waves to substation components. For this purpose, we used ATP-EMTP (Alternative Transients Program) software, which, owing to its user-friendly graphical user interface, can be effectively used for both scientific and educational purposes. Aiming for the modernisation of the Insulation Coordination curriculum, we are proposing modified problem-based learning which combines a classical approach with true problem-based learning (PBL). The pedagogical method and ATP-EMTP simulation model presented in this paper are primarily focused on undergraduate students (the fouryear programme), but can also be appropriate at higher levels of education.
Stokic E.,Clinical Center Vojvodina |
Brtka V.,Technical Faculty |
Srdic B.,University of Novi Sad
Computers in Biology and Medicine | Year: 2010
This paper aims to investigate possible application of the rough set approach to table-organized data in the medical domain, which reveals some relationships among sagittal abdominal diameter, anthropometric parameters and cardiovascular risk factors. When applied to table-organized data, the methodology based on the rough set theory is capable of producing decision rules in the form of If-Then rules. Such rules are suitable for inspection, examination and further analysis. By examination of the selected 30 decision rules, sagittal abdominal diameter could point out a group of obese and preobese patients with high content of visceral fat with different combination and composition of cardiovascular risk factors. These results suggest that sagittal abdominal diameter could be a clinically useful marker for identification of risk factors, combination and structure of total cardiovascular risk by applying different rules in obese and preobese persons. © 2010 Elsevier Ltd.