The article discusses the conditions for observing effects that manifest themselves when the flame front propagates in the channels and represents a system of geometric and thermo-physical parameters affecting the combustion of a gas mixture in stationary and dynamic modes. An experimental study of the propagation of the front of an air-gas flame in a flat channel with a fixed piston is carried out. The formation of eddy currents in the flame front is detected. The hydrodynamics and flame structure depending on the parameters of the experiment are investigated.

The article is devoted to computing test for adiabatic compression of an ideal collisionless gas in one-dimensional space. There is a description of particle density changes grouped by particle velocity over time for analytical solutions. The created software description is presented. The soft-ware allows simulating ideal collisionless gas dynamics with moving boundaries in the three-dimensional space by Monte Carlo method. Computing test series with different particle numbers and boundary velocities are run. The comparison between numerical results and analytical solutions is also made. The article contains software performance testing.

Between experimentally different situations, exist special physical interrelations. The corresponding observables of the compared processes may occur to be expressed by dissimilar mathematical expressions. Hence, numerical correspondences appear between different mathematical functions. To a large measure, the use of the present-day computer algebra packages removes the distinction between elementary and transcendental functions. Nevertheless, the software implementation of algorithms for computation of these functions retain some differences that may manifest themselves, e.g., in multiple recursions. In any case, the numerical likelihood of the different analytical expressions could be of interest for applications. Here we point at several examples of physically based interpolations.

The article proposes the geometric models of water and water vapor physical state with a further analytical description using the mathematical apparatus of geometric modeling of processes and phenomena (BN-calculation). The initial values of water and water vapor physical state are taken from the i-d diagram of humid air to simulate this process. Geometric modeling is presented as two different response surfaces for moisture content and enthalpy of humid air. Geometric models are a two-parameter set that belongs to three-dimensional space. Each response surface was divided into three compartments with defined boundaries and analytically described using point equations for arcs of curves passing through preassigned points. This allowed accurately calculating the desired values of the parameters in the software package Maple. The analysis of the effectiveness of geometric modeling of moisture content and enthalpy of humid air is given. The effectiveness is presented graphically based on i-d diagrams, and calculated values obtained based on the developed geometric models. The proposed geometric models allow determining all the necessary values of parameters of water and water vapor physical state. This allows automating the design process, as well as optimizing the simulation using mathematical analysis methods.

Initially, heavy equipment was used, which allowed highly accurate determination of “holes” inside a network, to assess the quality of radio coverage. Nowadays a smartphone has a computer performance and could be used for the purposes of checking the quality and power of a received signal from the mobile network, especially for the future 5G network based on slicing technique. The authors of the article developed an application for Android smartphones that could get the measurement data from the base station. The connection to the GPS allows determining more accurately the weak points in the coverage of the mobile network. Authors analyze and optimize the energy performance of the application based on a balance between the frequency of collecting and sending data to the server and the number of active users.

The paper provides an analysis of modern technologies for visualizing the pore space of rocks on a scale of several nanometers and above. A comparative characteristic and effectiveness of the use of various methods for porosity determination of rocks are considered. These methods include using a permeameter and an x-ray microtomography. The pore space of specific rock lithotypes is studied using high-precision analytical equipment on real samples. Elements of the pore space of various physical characteristics such as pores and microchannels connecting them or closing, and the matrix elements (minerals and high-density inclusions) are identified. A 3D digital core model based on initial data is created. Algorithms are developed to visualize the porous structure of a digital core model, as well as its permeability and fracturing of the mountain pore space.

The article considers the dependence of temperature on resistance of some conductor and semiconductor materials. Property from a group of heat conductivity of six various materials of different markings is described. According to the results of measurements dependence of resistance on temperature is received. The obtained data are presented in the form of graphics charts. In the following, based on test results the temperature coefficient of resistance of materials with linear dependence is calculated.

The article is devoted to the issues of software analysis that allows evaluating the quality of software products and the minimum quality level with incomplete information about software systems. Assessing software quality is an important task. The level of complexity of the software product is continuously increasing, therefore increases the number of errors that may affect the quality of the software.

In 1989, I. R. Prigogine was the first to draw attention to the problem of unstable systems. Nobody paid attention to the article “The philosophy of instability”, although the Nobel laureate devoted the theory of the thermodynamics of non-equilibrium systems to unstable systems. In the framework of the new theory of chaos and self-organization, we reveal the statistical instability of samples obtained both from an individual test subject (in unchanged homeostasis) and for a group of different test subjects. A new problem of loss of homogeneity in the group consisting of unstable elements surfaces. New criteria for assessing the homogeneity of groups that go beyond the limits of modern deterministic and stochastic science are proposed. Therefore, new concepts and new approaches in biomedicine are needed.

The article considers the organization of the storage of electronic documents in the document management system DIRECTUM and the model of the reverse movement of documents as well. The condition for placing texts of electronic documents in operational and archival repositories is described. An approach to the smart distribution of the texts of documents between them is proposed. The proposed approach can be implemented using a software robot, which will not affect the system functionality of the document management system platform DIRECTUM.

The article considers the creation of an automated analyzer of turbid media. The analysis of the medium is based on a modified method of dynamic light scattering. The article presents the experimental techniques, as well as screenshots from the data processor.

The article discusses the performance of the Java and .NET virtual machine interaction program interfaces. The performance subject of the interaction program interfaces (IPI) of the Java and .NET virtual machines is revealed by describing the course of an experiment in determining the most productive interface from the existing ones. According to the results of the experiment, a conclusion is drawn not only about the performance of the program interfaces of interaction between the Java and .NET virtual machines, but also about the approach and the sense of testing performance for any program interfaces of interaction.

The paper presents a Petri net model of the software life cycle from requirements gathering to implementation via UML. The characteristic of the business processes of the software life cycle is given. The Case-model and the marked Petri net model with detailed description are constructed. Afterwards, the reachability tree is implemented. The authors analyzed the Petri net for security and limitations resulting in the reliability of software.

This article considers a description of the mathematical model of one of the pursuit problems when the pursued object moves along a surface defined by a point basis, and the pursuing object moves along another surface located above the original surface. The speeds of the objects in our problem are constant modulo values. The “inertness” of objects is modeled using an angular rate of rotation. The simulation of the movement process is performed in the computer system MathCAD. This article describes the computational algorithm that is used to develop a program in the MathCAD system that implements the process of pursuing and evading the problem in real time.

The article considers an overview of the methods of classification of telemetric systems, presents the results of the system analysis of telemetry errors arising in the process of controlling electric power systems. Principles of classification of telemetry parameter errors are obtained using the example of the electric power dispatching center. The application area of each method of classification is shown. A generalized description of the sources of information about possible errors in telemetry is proposed. A general description of the process of detecting errors and restoring the reliability of the telemetry parameters of the dispatching center of the joint-stock company “System Operator of the United Power System” of the Russian Federation without using automation is introduced. The data transmission standards used in the power industry are given. Examples of using primary telemetry parameters for the calculation of secondary ones are described. The ways of restoring the reliability of parameters containing gross errors are enumerated. A table example summarizing the properties of telemetry parameters for making a conclusion about the accuracy and elimination of errors of reference data is given. The automation process of the detection and recovery of the verification of telemetry parameters, in general, is demonstrated. The concepts for using artificial neural networks for automation process of verifying telemetry parameters are mentioned.