Book chapter
Средства компьютерного моделирования механических процессов в электронной аппаратуре
In book
In operation results of computer simulation of characteristics of the standard analog device - the heterodyne executed on the printed circuit board from the composite dielectric having feeble conductivity are explained. Results of simulation showed that increase in specific bulk conductivity of material of the printed circuit board to 2·10 -7 Ohm -1 -m -1 practically does not change operating characteristics of a heterodyne. The possibility of effective use of the composite poorly carrying out dielectrics in standard radio engineering devices allowing to prevent origin of electrostatic discharges is set.
Computer simulations and experimental investigation for characteristics of the standard analog device – the heterodyne executed on the printed circuit board with replacement insulators from the composite dielectric having controlled dark conductivity have been carried out. Results of simulation showed that increase in conductivity of material of the printed circuit board (PCB) up to 2·10-7 Ω-1 ·m-1 practically does not change operating characteristics of a heterodyne in the range of the frequencies of 9 - 37 MHz. Simulation results are in good agreement with experimental data. Possibility of their effective use in space application devices, which prevents emergence of electrostatic discharges it, has been shown.
Mathematical and computer simulation of economic processes.
The results concern roll pass design for rolling a round bar of a 20mm diameter from a 55mm diameter input. Concerning materials, this roll pass design must cover a wide range of steels, from low-carbon micro-alloyed steels to stainless steels. The roll pass design proposal takes into consideration lower plasticity of certain steels. The comparison was enabled by suggesting two roll pass designs. The classical oval-round roll pass design, where the maximum extension coefficient is set to 1.55 in oval and 1.22 in round grooves. The second roll pass design uses a combination of smooth part of the roll (curves) and round roll passes. Distribution of the extension coefficient in individual passes is similar to that of oval-round series. The paper also compares values of energy-force parameters calculated analytically using the method of finite elements. If we compare the distribution of temperature, stress and size of the grain, it is proved that the oval-round roll pass designs are the best as far as the balanced distribution of the above-mentioned values is concerned. The roll pas design combining smooth part of the roll with a round part does not achieve such balance. However, its advantage lies in far lower requirement for the needed length of the working part of the roll. Five passes are carried out on the smooth part of the roll, which considerably cuts down the required length of the roll body. Therefore it is this variant that will be used in the laboratory of wire rolling created within the project RMSTC.
The problems of analysis and prediction in social networks are interpreted for the domain of marketing (other applications are also possible). Algorithms of determination of the strong subgroups and satellites for a network are implemented using the programming language R and tested on model examples. An original algorithm of calculation of the final opinions is proposed, implemented in R and also tested on the model examples. The main idea is that all control efforts in marketing (and other problem domains) should be directed only to the members of strong subgroups because they and only they determine the final opinions of all members of the network. Based on this idea, two problems of the opinions control on networks are studied. First, a static game in normal form where the players maximize the final opinions of all members of a target audience by means of the marketing impact to the initial opinions of some members of the strong subgroups. Second, a dynamic (difference) game in normal form where the players solve the problem of maximization of the sum of opinions of the members of a target audience by means of the closed-loop strategies of impact to the current opinions of the members of strong subgroups. In both cases we received the analytical solutions and conducted their comparative analysis. More complicated versions of the models are studied numerically on the base of the method of qualitatively representative scenarios in computer simulation.
The problems of analysis and prediction in social networks are interpreted for the domain of marketing (other applications are also possible). Algorithms of determination of the strong subgroups and satellites for a network are implemented using the programming language R and tested on model examples. An original algorithm of calculation of the final opinions is proposed, implemented in R and also tested on the model examples. The main idea is that all control efforts in marketing (and other problem domains) should be directed only to the members of strong subgroups because they and only they determine the final opinions of all members of the network. Based on this idea, two problems of the opinions control on networks are studied. First, a static game in normal form where the players maximize the final opinions of all members of a target audience by means of the marketing impact to the initial opinions of some members of the strong subgroups. Second, a dynamic (difference) game in normal form where the players solve the problem of maximization of the sum of opinions of the members of a target audience by means of the closed-loop strategies of impact to the current opinions of the members of strong subgroups. In both cases we received the analytical solutions and conducted their comparative analysis. More complicated versions of the models are studied numerically on the base of the method of qualitatively representative scenarios in computer simulation.