To facilitate the detection of various vulnerabilities, there are many different tools (scanners) that can help analyze the security of web applications and facilitate the development of their protection. But these tools for the most part can only identify problems, and they are not capable of fixing them. Therefore, the knowledge of the security developer is a key factor in building a secure Web resource. To resolve application security problems, developers must know all the ways and vectors of various attacks in order to be able to develop various protection mechanisms. This review discusses two of the most dangerous vulnerabilities in the field of Web technologies: SQL injections and XSS attacks (cross-site scripting – XSS), as well as specific cases and examples of their application, as well as various approaches to identifying vulnerabilities in applications and threat prevention. Cross-site scripting as well as SQL-injection attacks are related to validating input data. The mechanisms of these attacks are very similar, but in the XSS attacks the user is the victim, and in the SQL injection attacks, the database server of the Web application. In XSS attacks, malicious content is delivered to users by means of a client-side programming language such as JavaScript, while using SQL injection, the SQL database query language is used. At the same time, XSS attacks, unlike SQL injections, harm only the client side leaving the application server operational. Developers should develop security for both server components and the client part of the web application.

The paper addresses the development of technology for controlling access to digital portals and platforms based on assessments of personal characteristics of user behavior built into the interface. In distributed digital platforms and portals using personal data, big data is collected and processed using specialized applications using computer networks. In accordance with the law, the data is stored on internal corporate servers and data centers. Special attention is paid to the tasks of differentiation and control of access in modern information systems. Wide availability and mass scale of services should be accompanied by more careful control and user verification. Access control to such systems cannot be ensured only through technologies and information security tools; efficiency can be increased through software and hardware architectural solutions. The paper proposes to expand the currently developing SIEM technology (Security information and event management), which combines the concept of security event management and information security management, with blocks of user behavior analysis. As a characteristic that can be measured without overloading communication channels and is independent of the type of device used, the psychomotor reaction time is proposed, measured as the performance of actions with the interface. A technological solution has been developed for implementation in a wide range of digital platforms: banking, medical, educational, etc. The results of experimental research using a digital platform of mass psychological research are presented. For the research, data from a mass survey were used when answering (in the form of a choice from the available options) to questions about the level of education. Analysis of the reaction time data showed the possibility of standardization and the same indicators of specific users when answering different questions.

Electrical energy from power plants to industrial facilities and settlements is mostly transmitted by wire-connected air or underground lines covering vast territories. However, in some rare cases there is a need for wireless transmission of electrical power to objects located in hard-to-reach areas. The problem of wireless transmission of electrical energy will become especially urgent as space electric power industry based on the placement of solar power plants in outer space is being developed. In this regard, several countries are conducting studies on the problem of electrical energy transmission using both laser and microwave radiation. The fundamentals of building systems for wireless transmission of electrical energy over short distances using microwave radiation are considered. Two options for constructing such systems are analyzed and calculated: using parabolic antennas and using phased array antennas. For both options the main parameters of systems for wireless transmission of electrical energy at 200 m were calculated. In the first case, powerful microwave devices are used: a magnetron or a direct-flight klystron; in the second case, microwave powerful field-effect transistors. For the second option the summation of the powers of microwave generators by means of their mutual synchronization is proposed.

Antennas are one of the main elements of radio engineering systems. Phased antenna arrays (PAR), which make it possible to regulate the direction of radiation due to the ability to control the phases or phase differences of the emitted signal, are the most effective types of antennas. The size, design and shape of the PAR depend on the tasks to be solved, the type of emitters and the nature of their location. The article discusses the transformation of an equidistant PAR into a non-equidistant antenna array in order to reduce the level of side lobes and suppress diffraction maxima with a given minimum distance between the emitters. A model of a non-equidistant antenna array and calculation formulas for its analysis are presented. The method presented in the work based on iterative calculation methods makes it possible to select the main parameters of a non-equidistant PAR taking into account the bonds formed between neighboring radiating elements. The coordinates of the emitter elements of the non-equidistant PAR were calculated in a program using the MATLAB language. At the same time, a method was implemented to search for the optimal arrangement of emitters relative to each other, in which the directional pattern of the antenna array will have a minimum level of diffraction maxima and the required level of side lobe. According to the results of the program execution, the coordinates of the new non-equidistant PAR were obtained. The non-equidistant phased array antenna simulated according to the calculation results showed a complete absence of diffraction maxima, in contrast to the equidistant array, but it was not possible to sufficiently obtain the required level of side lobes. The calculated antenna radiation patterns presented for comparison showed the advantages of a non-equidistant antenn array.

Wide used method of digital filters design consists in transformation of analog filter-prototype with required performances into digital filter. This method is applicable if the transformation preserves optimality of filter performances under specified set of quality indexes (QI). It was denoted earlier that such situation is possible when gain-frequency response (GFR) and phase-frequency response are optimized simultaneously. The task of simultaneous optimization of digital filters GFR and step response (SR) is also important but yet a little explored. Alternative method of this problem solving consists in search of digital filter transfer function (TF) which is optimal under GFR and SR QI’s. To investigate capabilities of the first method we found examples of analog filters Pareto-optimal under rise time and transient duration. Other QI’s of these filters fulfilled specified constraints. Then these filters were transformed into digital filters. Bilinear transformation and transformation with invariant impulse response were applied. Further we did the search of digital filters optimal under the same set of QI’s. In either method the hybrid heuristic algorithm was applied for search optimal solutions in the space of TF poles and zeroes coordinates. The results of investigation demonstrated that digital filters developed via search are superiorly under specified set of QI’s then digital filters developed via transformation of analog filters. Accordingly Pareto-optimality for QI of GFR and SR is not preserved during such transformation and direct search must be applied to optimized digital filters simultaneously in frequency and time domains. Further in some cases analog filters developed via reverse bilinear transformation of the found optimal digital filters are superiorly under the same set of QI’s then analog filters developed using search. In such cases using of digital filter-prototypes for design of analog filters is practical.

The paper presents an overview of studies on the influence of the main parameters of ferrites on their ability to absorb electromagnetic radiation in the megahertz range (more than 10 dB). The main advantage of ferrites is a high refractive index (more than 1000) in the megahertz range due to the combination of high values of magnetic and dielectric permeability, which makes it possible to produce radio-absorbing coatings of small thickness (less than 10 mm) that effectively absorb electromagnetic radiation. Studies show that the attenuation of the power of electromagnetic radiation reflected from the surface of the ferrite is due to both interference processes and the processes of dissipation of electromagnetic energy during propagation in the ferrite. The inversely proportional relationship between the refractive index and the frequency of electromagnetic radiation in the megahertz range provides the condition for the interference minimum of the reflected radiation at a constant thickness of the ferrite coatings. A high refractive index slows down the speed of propagation of electromagnetic waves in ferrites, which enhances the processes of dissipation of their energy. The paper presents studies on the influence of the basic chemical composition of ferrites, alloying additives, microstructure parameters and technological modes on their magnetic and dielectric permeability. Studies have shown that an excess of iron oxide in excess of stoichiometry, which provides the semiconducting properties of ferrite grains, significantly increases the dielectric constant. High values of the dielectric constant of ferrites are provided by a combination of the dielectric properties of grain-boundary layers and the semiconducting properties of the grains themselves, which form the barrier capacity of grain boundaries according to the Okazaki mechanism. Alloying ferrites with oxides TiO₂, Bi₂O₃, CaO in an amount of up to 1 wt.% allows increasing the electrical resistance and dielectric constant of grain-boundary layers, providing an increase in the dielectric constant of ferrite as a whole. It has been established that the formation of a dense coarse-grained structure provides an increase in both the magnetic permeability and permittivity.

This article describes the application of optical nanocomponents for their further use in computer and information systems. it was revealed It was found on the basis of the analysis that the improvement of existing nanocomponents will allow to realize their full potential, as well as to find the use of nanoantennas in the field of creating communication lines on device boards as devices for receiving and transmitting data. Nanoantennas are promising devices that are already successfully used in modern microscopy devices. However, recently, optical antennas have begun to be applied in devices used in other areas of human life. As a result, the use of this technology can lead to an increase in the speed and volume of data transfer between the components of the integrated circuit. This, in turn, will increase the quality and speed of calculations in complex equations. A modeling technology has been proposed, and calculations of the necessary geometric parameters have been made, which will be suitable for the goals set by this work. On the basis of the proposed technology, four models that meet the required parameters have been developed. Calculations of the created three-dimensional models of nanoantennas have been performed. As a result of the study, a model has been identified that has the most balanced parameters suitable for its further use as the main device for receiving and transmitting data on three-dimensional integrated circuits.

The study of ultrafast laser interaction with graphene-like materials based on transition metal dichalcogenides attracts most scientific groups. It is connected with potential use of these materials in flexible optoelectronic devices of visible and THz range. In this paper the parameters of generation of terahertz field from the surface of bulk layered crystal and monolayer film of tungsten diselenide are analyzed. Generation of terahertz radiation from the surface of experimental samples was studied by the terahertz time-domain spectroscopy in reflection geometry. Bulk layered crystals of tungsten diselenide were grown by gas transport reactions. Monolayers of tungsten diselenide crystals were grown by chemical vapor deposition on a silicon substrate. The bandwidth of the generated terahertz radiation from the surface of the bulk layered tungsten diselenide crystal was ~ 3.5 THz. For tungsten diselenide monolayer the spectrum bandwidth of the generated THz radiation was ~ 2.5 THz. The peak amplitude of the generated terahertz field for both samples was at a frequency of ~ 1 THz. Research of the influence of the angle of rotation of a polarization plane of optical femtosecond pump on peak-to-peak amplitude of the generated terahertz field from the surface of investigated samples was carried out. Symmetry analysis of the azimuthal dependence of THz radiation made it possible to separate the mechanisms of THz radiation and evaluate their contribution. The analysis results confirm that the only possible contribution to the generation of terahertz radiation in a tungsten diselenide monolayer crystal is the second order nonlinear optical effect – optical rectification. One of the contributions to the generation of tungsten diselenide is a nonlinear-optical effect of the third order – surface optical rectification.

The paper shows the approach and the result of taking into account the mutual influence of on-board subsystems of a complex technical object along the DC power supply circuits. Technical objects are understood as a mobile, energy-intensive vehicle, such as an aircraft, a surface or submarine vessel, or a railway locomotive with strong magnetic fields. The aim of the work is to create a simple and intuitive tool for mathematical modeling of the magnetic field vector at an arbitrarily specified observation point. The task is being solved in order to improve the accuracy of magnetic measurements on board, in particular, in navigation problems. On-board DC networks are considered, to which the approach of mathematical modeling is applied. The disadvantages of commercial programs of a similar purpose are noted. The binding of the objects under consideration to the general coordinate system is described. An analytical algorithm for calculating the magnetic field vector from the on-board cable network with a pronounced 3D trajectory is shown. Examples of visualization of the simulation results are given. An algorithm for calculating the induction vector based on the Biot-Savard law is considered. The algorithm for the analytical solution of the problem is described in detail. A specific power cable of the on-board network is considered. The cable is given by a set of straight conductors with current. The ways of future improvement of the created product with the transition from one observation point to the field map in a given three-dimensional zone of arbitrary position, volume and orientation are outlined. The obtained result is considered as an element of the procedure for achieving electromagnetic compatibility of energy-intensive and highly sensitive subsystems of a modern complex technical object.

For non-stationary objects with parameters, which could be changed significantly during operation, using conventional controllers in the form of proportional-integraldifferential regulators may not provide the required quality of the system. Therefore, it is desirable to create an adaptive automatic control system with the structure and parameters of the control regulator that are purposefully changed to ensure the system adaptation, that is based on information about the properties of the object of regulation and external influences, to the changing operating conditions. The problem of designing adaptive systems is one of the most important in control theory and related fields. This is conditioned by two factors: the complexity of solving the problem as a whole and the presence of a large number of technically diverse situations that need to be adapted and optimized. In the paper, an adaptive system for the automatic control of the speed of a gas turbine engine, which includes a magnetic amplifier, a DC motor with a gearbox, a fuel supply valve and a tachogenerator, is developed. For adaptive control execution, three proportional-integral-differential controllers were proposed: "classic", fuzzy and neurofuzzy. The parameters of the "classic" controller were optimized using linear programming methods. The membership functions and the rule base were proposed for the fuzzy controller. An adaptation algorithm was selected for the neuro-fuzzy controller. Three controllers were used for three engine-operating modes: low-gas, cruiser and maximum during the computer simulation of the system. A comparative analysis of the quality of the three regulators was performed and it is based on the obtained transient characteristics. The derived results can be used in the development of automatic control systems for gas turbine engines.

Asymptotic and functional relations connecting the characteristics of scattered near and far fields with elastic and spectral characteristics of thin-walled elongated elastic shells described by the Love theory were found. The study was carried out by the method of two-scale expansions. For the near scattered field, recurrent systems of boundary value problems for Laplace and Poisson equations were obtained, the solutions of which were found explicitly. The radiation patterns of the scattered field were obtained using the theory of wave potentials for the Helmholtz equation. Asymptotic formulas for the potential densities of simple and double layers were found. This made it possible to present the asymptotics of the scattered field directivity diagram in the form of parametric integrals that depend on the angles of incidence and observation, frequency, surface shape, and material characteristics of the shell. The asymptotic method was effective for strongly elongated shells when the ratio of the maximum longitudinal diameter to the maximum diameter of rotation is more than ten. For such highly elongated bodies, the use of various difference and iterative schemes is problematic due to the difficulties of triangulating the shell surface. Numerical implementations of calculations of directional diagrams of a spheroidal steel shell in water at different angles of incidence of plane waves in a wide frequency range are given. The numerical calculations performed in this work are not tied to a specific frequency, since the geometric dimensions are given in wavelengths. Calculations have shown that the radiation pattern for elongated bodies begins to differ from the spherically symmetrical one at values kl > 4. When the wave size of the shell increases, the lobes of the directional diagram appear. The lobes direction depends on the above parameters. The number of lobes, their direction and power can be changed by using special distributions of the shell surface impedances.

The problem of risk assessment at the stages of the product life cycle using both qualitative and quantitative approaches is investigated, and a generalized algorithm for selecting a fuzzy risk assessment model with different input data and system requirements is proposed for the effective use of statistical information and expert assessments. The "risk-based approach" allows to reduce the cost of correcting possible errors in the future and reduce the uncertainty when performing subsequent actions. It is noted that the results of SWOT analysis, as a rule, are of a qualitative descriptive nature, and do not contain specific recommendations. The provisions of modern standards on risk analysis are analyzed and the classification of risk analysis methods is given in accordance with the provisions of the national standard GOST R 58771-2019 "Risk management. Technologies for risk assessment", in which the key is the concept of uncertainty, estimated using different scales of gradation of risk damage and probability of its occurrence. An approach based on fuzzy logic and a hybrid fuzzy neural network model is proposed, which allows to present the used criteria in a con-venient form and implement a logical conclusion using simple and visual production rules. At the same time, the effectiveness and accuracy of the developed risk assessment system based on fuzzy logic is mainly determined by the quality of expert information and the consistency of the methods used to obtain it. To improve the accuracy of the results, it is proposed to use collective expert estimates with subsequent analysis of the consistency of the obtained expert estimates by determining the coefficients of variation, rank correlation, concordation, and so on. A generalized algorithm of expert assessment is presented, which is recommended to follow when developing expert systems for risk analysis. Various models of fuzzy inference (Mamdani, Takagi-Sugeno, hybrid neuro-fuzzy inference) are considered. An algorithm for constructing a fuzzy risk analysis system based on an effective method for obtaining expert assessments and analyzing statistical information is proposed. It is suggested that if there is a priori information about previously occurred events that can be used for risk analysis and fore casting, the fuzzy conclusion should be refined using widely known methods of mathematical statistics, optimization algorithms, for example, gradient descent, simplex method or genetic algorithms. An example of developing a risk assessment system when an enterprise enters into contracts with both the customer and co-executors is given.