The paper discusses the matters of required gain approximation in the frequency range of operation using the Chebyshev criterion and Remez exchange algorithm. The equiripple problems have been solved, which yields polynomials in the form of the fourth order multipliers that approximate the different gains with different frequency ratios. The obtained polynomials make it possible to implement bandpass amplifiers with the required selectivity and gain. The dependencies of figures of merit (for dynamic and frequency ranges, frequency response stability) on the relationship of transfer function sensitivity to element parameters deviations have been analyzed. The criterion of optimality for bandpass amplifiers circuits in the form of the product of gain by transfer function sensitivity to active element parameters deviations has been defined. A circuit design for the fourth order bandpass amplifiers employing a single active element has been suggested. Design ratios for elements’ parameters that provide the minimum value of the optimality criterion over the frequency range of operation have been calculated. Comparison of the suggested and known fourth order function implementation has been made. It has been proved that the figures of merit of selective amplifiers constructed according to the suggested circuit design can be significantly improved.

Keywords: approximation, frequency response, selective amplifier, active two-port network, integrated amplifier, sensitivity characteristics, dynamic range, intermediate frequency amplifier, a noise level, a function of sensitivity

The article lists the main sources (objects and processes) that generate costs - a total of 19 possible sources, grouped into four groups. To monitor and take measures to reduce costs, it is advisable to build a formalized model and on its basis a software system that would allow to estimate all costs. This article is devoted to the construction of this model. An article on the estimation of total costs for all possible factors leading to losses and costs in warehouse freight turnover is not available in the literature.

Keywords: warehouses, warehouse, transport logistics, costs, functional scheme

The X-ray absorption spectroscopy (XAS) is a powerful tool for local atomic structure investigation of materials with different origin including nanocomposites. The extended X-ray absorption fine structure spectroscopy (EXAFS) is very sensitive to the details of local environment of X-ray photon absorbing atom. In order to perform quantitative study of EXAFS data the preliminary calculations of scattering phases and amplitudes of photo-electron in the crystal are required. The quality of this calculation highly affects on precision of such results, such as inter-atomic distances and coordination numbers. An existing methods use iterative self-consisted approach for the estimation of interatomic potential which could be neglected using fixed potential value in interatomic region (“muffin-tin”-zero). The Hedin-Lundqvist exchange potential is commonly used. The paper presents the results of the development and testing of computer code HFampl for the first-principle calculation of scattering phases and amplitudes within “muffin-tin” approximation using exact Hartree-Fock (HF) exchange potential. The development using GNU compilers collection has allowed an execution of the codes in any compatible operating systems (Windows, Linux, Mac). The atomic configurations were prepared for the most elements of the periodic table. The program tests performed on metals, oxides and iron-containing aqueous solutions demonstrated good applicability of the phases and amplitudes for the precise structural analysis, which allows accuracy up to 1% in interatomic distance calculation. Such accuracy in distances determination is as good as accuracy of common program packages. But values of other parameters (such as reduction factor and Debye-Waller parameter) are more realistic in case of application scattering phases and amplitudes obtained with HFampl code.

Keywords: Photoelectron Scattering Phases And Amplitudes For The Determination Of Atomic Structure By EXAFS Spectroscopy

This article presents the results of tests of samples on the basis of equiatomic alloy with shape memory effect. The obtained system of dimensionless quantities that adequately describe the elastic-plastic deformation. It is established that the assessment of scale effects in modeling shockproof device-based alloy with shape memory effect leads to the technical ability of extrapolation of experimental results to other objects to generate the initial data of the mathematical model under the condition of similarity of characteristics of external loads.

Keywords: shock proof device, elastic-plastic deformation, shape memory effect, protection of the joints, scale factor

Nanocrystalline TiO2 films are used as transparent layer n-type conductivity in the perovskite solar cells. The work presents the numerical diffusion-drift modeling of the transport processes and the accumulation of charge carriers in the heterostructure of TiO2 / perovskite / p-type semiconductor. The basis of the simulation put stationary physical and topological model based on drift-diffusion equations and semiconductor system allowing to model perovskite solar cells with a variety of electro-technological and constructive parameters. Obtained photovoltaic solar cell characteristics and plotted the efficiency of the TiO2 film thickness. The optimal thickness of the TiO2 film is 50-100 nm, thereby increasing the perovskite solar cell efficiency.

Keywords: Solar cell, thin film, titanium dioxide, p-i-n structure, numerical modeling

A strategic map for the IT company was developed. The problem of modeling a balanced system of indicators for an IT company based on colored Petri nets is considered. To organize the analysis of the structure of the system of balanced indicators, the goals and indicators are presented in the form of a colored Petri net consisting of a set of classical Petri nets. To organize a vertical and horizontal analysis of the structure of a balanced scorecard, the goals and indicators are presented in the form of a colored Petri net consisting of a set of classical Petri nets. The model proposed by the authors of the BSC on the basis of a colored Petri net, reflecting the "horizontal" and "vertical" structure of the BSC, allows modeling the dynamics of achievement of goals and changes in the indicators of the BSC based on cognitive analysis.

Keywords: BSC, IT-company, balanced scorecard, colored Petri net, model, strategic map, horizontal structure, vertical structure

During the motion analysis (design, model, body) a certain amount of data in the form of accelerometer readings with increments of 0.001 seconds – about a million of lines. At any instance of time we have to solve the problem of determining the acceleration of specified point of the solid body, taken as the pole. Therefore, our goal is to reduce the time for each iteration for determining the acceleration of the given solid body pole.

Keywords: solid body, center of mass, instantaneous angular velocity and acceleration

In this study, the task of optimizing the supercomputer CPU cooling system with a heat pump in the reverse Stirling cycle through numerical modeling of heat transfer processes in the test object The article presents numerical modeling of heat transfer processes in the cooling system of the supercomputer processors with a heat pump on the return cycle. We investigated the numerical model of heat transfer process in the system of CPU "cold" cylinder and heat pump system "hot cylinder" - coolant. As a result, obtained according to the thermal resistance of the system of CPU "cold" cylinder and heat pump system "hot cylinder" - coolant depending on the coefficient of heat transfer and on the value of COP of the heat pump

Keywords: processor, heat flow, the thermal resistance of the Laplace equation, heat pump, heat exchange, reverse Stirling cycle cooling system

In the article possibilities and elements for PHIL simulation of multifunctional modular systems (MFMS) are considered. For this purpose, mathematical studies of such systems were carried out, the tasks of their basic elements were singled out, and the main task was to create a universal modular model. The structure of the energy MFMS and its problems from the position of graph theory are determined. The analysis of the existing methods of PHIL simulation is presented, as well as the structure of the simulated fragment of the system at the junction of the two modules is defined with using the "coupling" method of the scheme. As a result, conclusions were drawn about the possibility of applying a PHIL simulation to the MFMS.

Keywords: PHIL simulation, modular systems, macro task, power hardware-in-the-loop simulation, analog-digital system, numerical part, analog part, Gauss-Seidel method, Jacobi method

The main maintenance of a diversification of production as activity of subjects of managing is considered. being shown in purchase of the operating enterprises, the organizations of the new enterprises, redistribution of investments in interests of the organization and development of new production on available floor spaces. The most important organizational economic targets of a diversification of management are presented by innovative activity of the industrial enterprise.

Keywords: mathematical modeling, numerical methods, biological tissues, oncology, microwave radiothermometry, heat transfer, radiation fields

Is considered a two-dimensional finite element analysis of unsteady thermal regime is made of heterogeneous layers of composite construction. The degree of influence of individual geometric design changes on the character of distribution of temperature on its volume. Heat is produced from internal volumetric sources of heat, removal of heat from the outer surface by convection. The calculation of the temperature field using two-dimensional heat conduction equation (Fourier equation)

Keywords: numerical calculation, finite element, heat conduction, convection, Fourier equation, temperature field, layer, plate, heterogeneity, design

The paper presents the results of a comparative analysis of estimates of the levels of emotional perception, is satisfied in full and shortened semantic scales. The studies were performed on specific experimental data obtained in the measurement of deprivation attitudes of students Academy of architecture and construction DSTU at the end of 2016. It is found that the decrease in the number of signs in the semantic scale to the optimum leads to small changes in the assessments of emotional perception. At the individual level the changes are mostly (70%) not more than 10%,and in the whole group even less.

Keywords: relative deprivation, semantic space, factor analysis, rating scale, experimental regularity, factorization of scales, psychophysiological nature of the law of factorization, the optimal set

This paper presents an overview of modern adaptive control systems for vehicle. It shows simulation results of vehicle flight with using the adaptation algorithm for position-control system, with estimation loop of additional disturbances, and with the reference mathematical model and astatism. The simulation results for two cases (for given constant coefficients of adapting and using the automatic settings adjustment coefficients) are presented.

Keywords: adaptive control, helicopter, position-trajectory control, observer, estimation, vehicle, flight,simulation

This article describes one part of the development of the testing device of the magnetostrictive materials. Overview of the various designs of magnetizing systems and methods for increasing the sensitivity of the measuring device was made. The application of artificial neural networks to determine the magnetic properties of materials of the tested samples was reviewed

Keywords: magnetostrictive materials, magnetic characteristics, magnetization curve of the material, full-scale model experiment , modeling of magnetic circuits, magnetic shunt, Artificial Neural Networks.

An algorithm for the synthesis of the optimal values ​​of the parameters of precision manufacturing, assembly and balancing of assembly units and parts of machinery for agricultural purposes on the basis of the simulation of its dynamics. It is shown that the accuracy of the parameters of execution units of a conflict affect the cost of production and operation of the machine. This is the basis of the optimal values ​​of these parameters for the search criteria to minimize the amount of these costs. Along with the optimized parameters into account other characteristics of the aggregates (their weight, mode of operation and so forth.), Which are related to the optimization of resources. A variation of the latter with the search for the optimal solution provides the required quality indicators of the unit. The proposed method of synthesis parameters tested calculation accuracy performance rotor grinding drum crusher feed DB-5. These calculations showed the possibility of redistribution of allowances for the execution of the test drum sizes for optimal reduction of production costs.

Keywords: agricultural machinery, machine, design, accuracy performance optimization

The article describes development of the algorithm and realizing software application for mathematical model of stationary liquid stream influence to the spherical body under viscous film. The algorithm is designed to obtain the formula for calculating of stationary liquid stream influence to the spherical particle. Realizing software application is created. In Russia all rights for the software application are protected by the state certificate of computer program registration.

Keywords: algorithm, viscous liquid, viscous film, mathematical modeling, software application, liquid stream influence, spherical body

The article discusses the development of graph databases in the rapidly growing volume of generated and processed data. The purpose of this paper is to analyze graph data models, demonstrate their advantages over the others, as well as the formulation of the problem of the development of a new method of representing graphs in computer memory.

Keywords: database, data structure, graph data model, SQL, NoSQL, indexing, data analysis, data scheme, graph representation

The paper considers the method of experimental evaluation of the signal / noise ratio in relation to space communication systems. The basis of the high-precision evaluation method laid experimental signal / noise ratio is implemented by measuring the average number of the envelope of the additive mixture signal emissions and narrowband normal random process.

Keywords: Space communication system, command-and-measurement system, signal / noise ratio, the number of emissions, the envelope of the additive mixture, rms noise level restrictions, the sub-carrier frequency

In this paper discussed the main problems when choosing the optimal reservation of information systems. The algorithm of optimization of redundant information systems. Defines the basic concepts of developing mathematical models of redundant information systems. Given and illustrated by an example of calculation of the main reliability characteristics of a redundant information system.

Keywords: mathematical model, simulation, redundancy, information system

This article deals with the carrying out of econometric analysis by means of panel data models (pooled model, fixed effects model) of the volume of innovative goods, works and services in the Russian Federation (RF) from 2010 up to 2014 years. The dependence has been revealed between the volume of innovative goods, works, services and such explanatory factors as the number of personnel involved in scientific research and development; internal expenses for the scientific researched and development of the Russian Federation; used advanced manufacturing technologies; coefficient of inventive activity; innovation activity of organizations.

Keywords: econometric analysis, panel data, innovation, science, integrated model of panel data (pooled model), a model of panel data with fixed effects (fixed effects model)

An algorithm for the synthesis of the amplitude-phase distribution in quasi-circular antenna array for a given amplitude-phase radiation pattern is considered in the article. Selection of amplitude-phase radiation pattern as the set is due to the ability to use the most simple method of amplitude-phase synthesis of amplitude-phase radiation pattern. The predetermined amplitude-phase radiation pattern parameters (width of main lobe, level of side-lobes) are selected on the basis of physically realizable amplitude-phase pattern. The amplitude-phase radiation pattern may be formed using an circular or linear antenna. The solution is reduced to the formation of an overdetermined system of linear algebraic equations for the unknown complex amplitudes of the excitation currents in quasi-circular antenna array. The coefficients of the unknowns in the system of equations are amplitude-phase radiation pattern each of emitters for certain number of angular. The number of lines exceeds the number of emitters in a part of the antenna. The question of the possibility of saving the amplitude-phase radiation pattern parameters in the transition from the ring to the quasi-circular antenna array are discussed. Achieved mean square difference between the ring and the amplitude-phase distribution pattern quasi-circular antennas does not exceed 0,001.

Keywords: ring and quasi-circular antenna array, capability of pattern, amplitude-phase distribution synthesis

The simulation of the magnetic field distribution in magnetic conductors of electrotechnical devices for the purpose of assessment of their characteristics in the operation modes is considered. The task has a form of the boundary value problem for the elliptic type equation in the ferromagnetic environment with nonlinear characteristics. We suggest using block elements in the form of arbitrary configured multipolar networks in the combination with nonlinear multangulars. The veber-ampere characteristics of the multipolar network are the result of a single solution of the boundary value problems for the multangulars forming block elements. The boundary value problems are solved using a complex finite element method, which provides direct solution for equations of constraints between magnetic strains and multipole fluxes. The nonlinearity of the characteristics is taken into account as a result of calculating the field distribution at the boundary of the multipoles by correcting the magnetic permeabilities of the block elements, which is performed iteratively.

Keywords: electrotechnical system, magnetic circuit, boundary value problem, block element, multipolar, complex boundary element, conductivity matrix

The process of profiling tubes with rollers was considered. The method of solving the problem was considered. The stress-strain state of the metal in this process was determined, the equations of relative deformations was given, the shear strain intensity in cylindrical coordinates are given for the case of a plane homogeneous deformed state. The stress state index was defined

Keywords: Pipe profiling, deformation, stress, flat pattern, mathematical model, stress concentration, stress-strained state, stress state index

In this paper, we describe the developed formalized method for the synthesis of virtual models of process equipment that allows in computer-aided programming systems of multi-axis CNC machines to associate a mathematical model of the machines and their three-dimensional models in a single model and also automates the process of creating virtual models of machine tools of various types in these systems.

Keywords: automation of the process of preparation of control programs, formalized method of synthesis of virtual machine models

The article proposes a new formulation of the knapsack problem, and also considers the mathematical model used to solve the problem of choosing the optimal strategy for information protection of distributed systems. The essence of the new task is expressed in the use of a set of goals when completing a knapsack.

Keywords: Information security, information protection, distributed system, combinatorial problem, mathematical modeling, knapsack problem, equivalence, model of threats.