When designing the thermal regime of composite structures and structures characterized by a mixed type of heat exchange due to its complex physico-chemical and geometric structure, it is often necessary to know its effective thermophysical characteristics. In this paper, we propose a method for restoring the effective thermal conductivity tensor as a function of temperature based on minimizing the root-mean-square error between the theoretical and experimental temperature field at the temperature sensor installation sites. This technique has been tested on the frame of the descent spacecraft "Eagle". Since these tasks are considered incorrect, it is necessary to apply regularization that mitigates the error of the input noisy data. The algorithm of conjugate gradients is chosen as the minimization method, as the most accurate method of the first order of convergence.

This paper presents a setup for studying the current-voltage characteristics of LEDs, as well as determining the band gap of the material and the wavelength of the LED radiation. The installation is structurally a monoblock with LEDs under investigation, which has connectors for connecting an external power supply and voltage and current meters. An electronic circuit is presented and the principle of its operation, a measuring circuit, and a printed circuit board drawing are described. A technique is described for measuring the band gap and wavelength of an LED using the current-voltage characteristic. This installation is used in the educational process when conducting laboratory classes in general physics when studying the topic "Elements of the band theory of solids." Also, the installation can be used for scientific research in semiconductor physics.

Every year the volume of corporate data to be analysed in financial controls increases, which makes it relevant to introduce Big Data processing techniques into the practice of control subjects. The purpose of the study is to develop and test three techniques of Big Data processing in order to solve the problems of public and private sector organisations carrying out activities in the field of financial control. As research methods, we have chosen three most promising and effective means of processing Big Data, which at the same time do not require the use of complicated mathematical apparatus or significant computer power for their implementation, namely, a statistical tool for detecting errors in financial data Benford's law, clustering method of K-means and the means BI-system Power BI. The result of the study is the confirmation of the effectiveness and cost efficiency of the considered techniques of processing Big Data and the justification of the practical possibility of their implementation as financial control tools. The research was conducted in the student Financial Intelligence Laboratory of NRNU MEPhI.

Mobile platforms based on hexapods are widespread and are used in various fields: dynamic simulators, robot manipulators, orientation systems. When designing such systems, computer modeling is used and an important issue is the creation of a simulation model of the hexapod control system and the assessment of the resulting positioning errors. The article presents a simulation model of a hexapod robot developed in the SolidWorks computer–aided design system. A mathematical description of the hexapod model, a robot diagram in the MATLAB program, as well as an algorithm for extracting errors between the given and received coordinates and angles of the center of the platform are presented. Diagrams of the change in the position of the center of the platform, the positioning errors of the rods and the efforts applied to each rod over a certain period of time to measure the positioning accuracy of the hexapod are shown.

The purpose of this work is to study the analytical solutions of a dynamic model with a constant delay. Models of this type are used in biomedical research, for example, in the study of the spread of infections, the distribution of drugs in the body. A modification of the multifractional absorption model (MFA model) including a delay is proposed, and its analytical solution is obtained. It allows you to adequately model the distribution in the blood of medicinal substances characterized by a non-standard mechanism of absorption of the dosage form upon oral administration. According to the literature data on the pharmacokinetics of the drug sumatriptan in volunteers after oral administration of 50 mg of the drug, the distribution of the substance in the blood was calculated using the proposed MFA model with a delay. The model made it possible to adequately describe the distribution, which is characterized by two peaks in the concentration of the drug in the blood.

In order to extend the operation life of the BN-600 reactor, it is necessary to validate operability of the permanent reactor elements – including the neutron reflector – that operate under the conditions with high damaging doses and high temperatures. It can be done through irradiating metal of simulating package inside a materials science assembly inserted in BN-600. The paper describes basic characteristics of the assembly, including design features and irradiation parameters. Described are the basic principles of selecting the location for the materials science assembly in the reactor and for specimens inside the assembly in order to ensure the required irradiation conditions for the metal specimens. With comparing the materials science assembly locations in the reactor core and in the radial blanket, the effect is discussed that the materials science assembly location has upon the characteristics of the reactor standard fuel assemblies and upon the neutron flux field. To calculate the irradiation parameters and the effect that the location has upon the materials science assembly, the same methods and programs are used as for the reactor core design work. The effect of the materials science assembly upon the reactor core neutronic characteristics has been shown to be minimum when the assembly is inserted in the radial blanket.