In investigation of consequences of atmosphere and commutating striking voltages, for simulation of the overvoltage are used the models of generators whose RC circuits have standard passive parameters of the elements upon which the form of striking overvoltage depends. According to IEC 62 305-1 standard, these formulas in the theoretical model serve for dimensioning the RC circuit of the generator of striking voltages although the definitions of time constants and passive parameters have only axiomatic character. Related to classical solution, this paper presents the model formed by mathematical procedure the solutions of which give sufficiently accurate values of time constants and essential parameters of RC circuit as well as the shape of striking voltage wave. The formulas for voltages and currents in model contain parameters of passive elements, and their accuracy has been confirmed by diagrams obtained in simulation by means of adapted psbtrnsrg.mdl part of MATLAB program. Theoretical model is suitable for simulation of standard wave forms of striking atmospheric and commutating overvoltages which replace laboratory testing.

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Contemporary architectonic design mostly relies on the software tools which enable the engineers to analyze multiple factors affecting a space, and to timely detect and correct certain errors in designing, resulting from attempting to satisfy certain aspects of a space at the expense of others. Those tools which apart from architecture itself also consider other fields of science, depending on the function of these areas are important; thus in the lecture halls designing process, adequate software for analysis is used. In addition to a number of acoustic parameters characterizing the acoustic response of a room, in terms of design, one of the most important factors affecting the acoustics of the indoor areas is reverberation time, which is characterized by the architectonic parameters: room volume (dimensions), shape (form) and materialization (finish material). In this paper, for the purposes of acoustic analysis of the A amphitheater, the parametric values obtained in two ways, by experimental measuring and by software-Autodesk Ecotect and Autodesk Revit Architecture are compared. The software is increasingly used in contemporary architectonic software because of the option to analyze acoustics of indoor space, so there is a need to analyzed the values provided by the software and compare them with actually measured reverberation time.

Underground installations are networks of metal pipes and cables in space at a certain distance from the ground surface. Insulating layers of metal pipes of underground installations (gas, plumbing, electrical...) do not provide their full protection against corrosion and breakdowns. In urban areas, wandering currents (electric rail or earthing of power plants) repeatedly increase failures in underground installations in the environment. That is why a certain kind of protection is foreseen for the protection of metal pipes of underground installations against corrosion and destruction from wandering currents. However, until today there is no universal method for calculating the parameters of stationary and quasi-stationary electric fields of wandering currents and a general solution for arbitrary configuration, but it is possible to form a model algorithm for controlling the state and failures of insulation of underground electrical installations. Solutions for wandering currents could be determined by the criterion of similarity to transient currents on power lines. In the paper, in program MATLAB Simulink a simulation for the correction of wandering currents using foreign grounding has been performed on certain parts of underground installations. It has been shown that the solution of the task is possible with help of the model-algorythm which allows a determinaitn of the power on isolation layer of the cable sheat, and with simulation of the different versions of schedule of protective equipment, their optimal schedule could be determined.

The decision of Roman Emperor Trajan to build this famous bridge also influenced the stone constructions of the associated castra on both sides of the Danube, in the areas of today's village of Kostol in Serbia and the town of Drobeta-Turnu Severin in Romania. For this reason, we analyse in this paper the castrum Pontes in Serbia, which we suppose was characterized by dimensional relations between the constituent elements. Certain relations noticed in the plan of castrum fortifications can also be observed in the plan of an individual building -within the main principia.The classical plan of a Roman principia and the specific geometric relations in the case of Pontes Principia influence certain social relations of users and this building. An analysis of analogous solutions in the auxiliary castra of Limes also contributes to a better definition of the functions of certain rooms of the principia. However, by applying modern software designed for architectural analyses, we can study the above relationships more thoroughly and offer suggestions for functions that have not been determined yet.