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The aim of this study was to determine the change in the value of morpho-metric parameters of antlers and the total trophy score in relation to the age of roe deer (Capreolus capreolus L.). The study was conducted on 228 roe deer trophies from the "Barajevska reka" hunting ground in Serbia, aged one to seven years. From the second to the fourth year, the growth of antlers was the most intense, and the differences compared to one year old animals were significant (P lt 0.001). The highest average length of the branches was monitored in six years old animals (22.4 ± 2.05 cm), with significant differences (P lt 0.001) compared to younger animals, except for the three years old animals (P>0.05). From the second to the fifth year, a gradual increase in antler weight (from 192.2 ± 30.41 g to 221.9 ± 61.86 g) and antler volume (from 74 cm3 to 90 cm3 ) was observed, with the highest values of antler weight (291.8 ± 58.43 g and 319.1 ± 98.89 g, respectively) and antler volume (123.8 cm3 and 121.2 cm3) in six and seven year old animals. Overall trophy scores increased from year one to year seven (42.6 ± 7.86 vs 97.4 ± 27.40), with differences in trophy scores for animals aged six and seven years significantly greater than for animals aged one to five years (P lt 0.001). The highest quality antlers have six and seven year olds, at which time their hunting should be conducted. Cilj rada je bio da se utvrdi promena vrednosti mernih elemenata ocene parogova i ukupne ocene trofeja u odnosu na uzrast srndaća (Capreolus capreolus L.). Istraživanje je obavljeno na 228 trofeja srndaća iz lovišta "Barajevska reka" u Srbiji, uzrasta od jedne do sedam godina. Od druge do četvrte godine rast rogovlja je bio najintenzivniji, a utvrđene razlike su bile signifikantne (P lt 0,001) u odnosu na jednogodišnje jedinke. Najveća prosečna dužina grana parogova je zabeležena u periodu oko šeste godine (22,4±2,05 cm), pri čemu su utvrđene razlike bile signifikantne (P lt 0,001) u odnosu na mlađe jedinke, osim u odnosu na jedinke u starosti od tri godine (P>0,05). Od druge do pete godine uočen je postepeni porast mase rogovlja (od 192,2±30,41 g do 221,9±61,86 g) i zapremine rogovlja (od 74 cm3 do 90 cm3 ), dok su vrednosti mase rogovlja (291,8±58,43 g i 319,1±98,89 g) i zapremine rogovlja (123,8 cm3 i 121,2 cm3 ) kulminirale kod jedinki u starosti šest i sedam godina. Ukupne ocene trofeja su rasle od prve do sedme godine (42,6±7,86 prema 97,4±27,40), pri čemu su razlike u ocenama trofeja kod jedinki uzrasta šest i sedam godina bile signifikantno više u odnosu na jedinke starosti od jedne do pet godina (P lt 0,001). Najkvalitetnije rogovlje imaju jedinke uzrasta šest i sedam godina, kada bi trebalo i vršiti odstrel.

Load flow is the most used calculations in power system operation planning. Renewable resources have caused that system operator has to do power flow analysis and/or contingency analysis as fast as possible in order to predict next step in power system control. LU Decomposition of Jacobian matrix remains the most computationally expensive task during Newton–Raphson iterative method. Computational time appears to be critical issue when load flow calculation is performed on large power system load flow models. In this case, Jacobian matrix LU decomposition should not be performed in iterations in which convergence rate is not violated but performed in iterations in which convergence rate drop below specified level. In other words, modified Newton–Raphson Method which eliminates the repeated Jacobian matrix LU decomposition and generic Newton–Raphson method are combined depending on convergence rate. The paper presents application of proposed combined Newton–Raphson method which is based on convergence rate control. Comparison of combined, Shamanskii, generic, and modified Newton–Raphson methods is carried out taking into consideration computational time and number of iterations required to achieve convergence of load flow models of various dimensions.

Power plant electricity production control is very much dependent on the type of power plant. Some types, such as storage hydro, have very good power control capabilities. On the other hand, electricity production of wind power plants is strongly dependent on the wind that is forecasted with some degree of uncertainty. If wind power plant production misses the schedule submitted to transmission system operator, the production of another power plant has to be altered in order to compensate mismatch of scheduled power production. This specially refers to sudden changes caused by outage of wind generators as a result of high wind speed. Wind power plants control could cause unpredictable power flows in the transmission network if their production is controlled by power plants that are not located in their electrical vicinity. This paper reviews the Balkans region characterized by high wind potential, the existing hydro power plants enabling efficient power control, and potential for construction of perspective hydro power plants, making this region very suitable for construction of large wind power plants.