The analysis of the foundations of modern cryptographic systems is carried out. Problems of classical cryptography arising in the development of quantum computers are considered. Considered are cryptographic protocols of quantum key distribution, their advantages and disadvantages. The analysis of stands for simulation of quantum key distribution available on the market is carried out. The rationale for the need to develop a training system has been made. The authors have developed a system for modeling and demonstrating quantum cryptographic protocols BB84, B92 and BB84 (4 + 2), intended for a detailed study of the principles of quantum cryptographic protocols in dynamics. The system provides the process of work both in text and graphic form. The developed system fully meets the needs of teaching students modern quantum information security technologies.

Keywords: information security; encryption; quantum cryptography; modeling; education system

As part of the development of the stages of pre-project and design preparation, a set of procedures is carried out, starting with planning further stages of the implementation of a construction project, ending with obtaining a construction permit. The article describes the main provisions of the methodology for choosing rational organizational and technological solutions at the stages of pre-project and design preparation of an object for construction, and also presents the results of its implementation in construction practice. The methodology defines the main procedures at the stages of pre-project and design preparation of facilities for construction; factors influencing the duration of the procedures at the stages of pre-project and design preparation of facilities for construction. On the basis of the methodology for choosing rational organizational and technological solutions at the stages of pre-project and design preparation for the construction of an object, organizational and managerial models for passing the stages with determining the duration of procedures, taking into account the influence of factors, have been developed. The proposed methodology, used in the practice of the organization, made it possible to take into account the influence of factors on the duration of the stages of pre-design and design preparation of the above facilities for construction, thereby reducing it.

Keywords: technical customer, developer, stages of pre-design and design preparation of facilities for construction, organizational and technological solutions

In the modern world, the number of different complex technical systems is only increasing every year, and any system incorporates or uses a third-party communication system. Disruption of the communication system and its elements functioning can lead to a situation where a complex technical system cannot realize its functions. It is required to ensure the guaranteed functioning of the communication system and its elements. One of the ways to ensure the stable operation of complex technical systems is the implementation of the control function by the control system, while in the process of system operation it is necessary to take into account not the characteristics and parameters of individual elements that describe their operation, but the ability of the system to perform tasks and functions. The paper proposes an approach to describing the functioning of a communication system through the formation of the system functioning profile, which is a set of matrices, which is used in the control system.

Keywords: functional stability, criticality, communication system, control system, complex technical system, functions, tasks, profile, regulations

It is reported that recently, in many sectors of human activity, there has been an increasing interest in involving chatbots in company, organization or firm websites and in various applications to provide necessary assistance. This article deals with the current definitions of a chatbot and artificial intelligence. A chatbot is a computer program that imitates human speech using artificial intelligence. Artificial intelligence is a science and technology based on such disciplines as computer science, biology, psychology, linguistics, mathematics, and engineering. In the educational field, chatbots are useful for providing guidance and information about courses, admission processes and procedures, academic programs and academic services. However, these virtual assistants have limited mechanisms that could help the teaching and learning process. Attention is drawn to the fact that these mechanisms should be beneficial to all people involved. For this reason, the Voronezh State Industrial and Humanitarian College (GBPOU VO «VGPGK») was identified as the subject area in the development of a chatbot in the social network "VKontakte" for the page of an educational organization.The article considers the possibilities of using chatbots in the social network "VKontakte" for an educational organization focused on students and their parents. The article gives information about the development of the client part of the chatbot, namely the possibility of launching an electronic assistant using the page of the social network, the description of the data storage system for the chatbot and the server part. It is specially noted the variants of solutions for realization of a chatbot and the functioning of a chatbot.

Keywords: chatbot, website, server, client part, applications, social network, "VKontakte", mobile devices, artificial intelligence, computer program, information, educational sphere, message, training, data storage, electronic assistant

The work is devoted to the problems of protecting the document management system of public administration bodies. The aim of the work is to build a simulation model of the implementation of a targeted computer attack, taking into account the simultaneous (occurring with a slight delay) response of the security tools of the document management system. For modeling, it is proposed to use the apparatus of Petri-Markov networks, combining the representation of the change of states of the attacked system in the form of Markov (semi-Markov) processes and the expressive capabilities of Petri nets to describe the interaction of processes. The constructed model reflects both the specifics of attacks with increased user privileges, and the features of document processing processes, as well as the mechanisms used to counteract unauthorized access. Computational experiments conducted using the constructed simulation model allow us to assess possible risks and make a decision on choosing the most effective system of protection against the considered type of attacks.

Keywords: electronic document management system, computer attack, simulation modeling, Petri-Markov network

The most significant advantage of composite structures compared to structures made of traditional materials is the ability to control the characteristics of the structure in order to obtain an optimal design. In the general case, the initial physical characteristics of the material of the composite structure are random variables. Consequently, the required quantities (stresses, strains, critical loads, etc.) are also random variables. The problem of statistical modeling of a composite structure is ultimately reduced to the problem of transforming random variables. To solve this problem, the Monte Carlo method is used. The object of study is a multi-walled plate under the action of compressive loads. The purpose of this work is to construct point estimates of the coefficients of both general and local stability for a multi-walled plate, as well as to test statistical hypotheses about the equality of the stability coefficients to their theoretical values. The initial parameters are the elastic moduli in the longitudinal and transverse directions, as well as the shear modulus of the construction material. The following were used as output values: sample mean, standard deviation, skewness and kurtosis coefficients. All calculations were carried out in the environment of the MAXIMA package. It is shown that the distribution of the overall stability coefficient practically does not differ from the normal distribution. The coefficient of local stability has a slight positive asymmetry and a steeper peak compared to the normal curve. The results obtained allow us to conclude that the spread of the elastic characteristics of the material does not significantly affect the coefficients of the general and local stability of the multi-walled plate.

Keywords: statistical modeling, statistical hypothesis, multiwall plate, stability, critical load, composite material

The article is devoted to the use of renewable energy sources, namely geothermal energy for home heating. Methods of installation, advantages and disadvantages of geothermal heating are investigated. A comparative analysis of the cost of 1 MJ of heat received from various energy sources was carried out, and the efficiency of using heat pumps for heating buildings was proved. It was noted that in connection with the global problem of greenhouse gas emissions, this decision is relevant and paramount for achieving hydrocarbon neutrality. The introduction of geothermal heating methods can be a huge step towards green energy.

Keywords: system, temperature, geothermal heating, heat pump, compressor, evaporator, condenser, carbon footprint, ecology, green energy

The water sector in Syria suffers from longstanding problems and faces many challenges in terms of water supply and quality sanitation. These challenges include water scarcity, increasing water demand due to population growth and conflicts in the region, rapid urbanization, water pollution, limited access to drinking water and sanitation in rural areas, inefficient water distribution system in addition to constant network failures, as well as lack of financial resources, inefficient water pricing system and methods, cost recovery and asset management. As a result, the need for a significant quantitative increase and qualitative improvement of engineering infrastructure facilities (water supply and sanitation systems) and parts of distribution networks, in addition to the technical capabilities and development of resource management methods, which in turn leads to improved management of water supply and sanitation systems and the welfare of the population in the region, clearly becomes apparent.

Keywords: water supply and sanitation systems, Syrian Arab Republic (SAR), reconstruction, consequences of military operations, urban planning

A model of interaction between a railway and a seaport has been developed in the presence of a governing body. Interaction functions are described for the proposed model, analytical solutions for the static model are found, and the simulation speed is compared without and with the use of analytics. Next, a dynamic model is considered and an algorithm for finding an equilibrium for this model is proposed. The subsequent use of parallel programming methods will make it possible to plan interaction in this model to a better extent.

Keywords: mathematical model, simulation modeling, Stackelberg equilibrium, hierarchical game, mixed transportation, railway transport, port

For prototyping virtual resources, there are modern UI/UX development applications that have the means to build highly productive interaction algorithms, for example, Figma or its promising new competitor Pixso. These programs support the joint redating of projects, and also allow planning and discussion of ideas and stages of work here, in the environment. The correctly chosen method of interaction leads to a multiple increase in productivity. One of the recognized approaches to project planning and management is the Agile design methodology.

Keywords: team, layout, prototype, website, methodology, formal language, brainstorming, frame, project, interface, plugin, editor

The work is devoted to the problems of strategic planning in the digital technology market. The aim of the work is to build a decision support procedure for choosing a strategy, based on internal (related to the characteristics of the firm choosing the strategy) and external (conditioned by the state of the market) factors. It is assumed that the elementary strategy is described by the type, direction and applied area of activity. In this case, the possibility of combining several elementary strategies is considered. The main result of the work is a procedure for choosing a combined strategy based on the application of a genetic algorithm. The use of the methodological apparatus of evolutionary calculations is due to the large number of possible options for combined strategies and the complexity of their evaluation, which makes a complete enumeration of options impractical. The final choice is made by the decision maker based on their own preferences.

Keywords: IT market, decision support, genetic algorithm

The article presents the study results of a soil-like fraction contamination at a landfill located on the territory of the Traktorozavodsky district of Volgograd with heavy metals. The soil-like fraction's pollution level was assessed using a cumulative chemical pollution index (Zc) and its modifications. It was determined that the contamination levels with heavy metals are dependent on a used cumulative chemical pollution index modification. The use of the average geometric values of a cumulative chemical pollution index (Zc) is preferred for a pollution assessment of a soil-like fraction. Because the pollution level of a studied soil-like fraction was assessed as hazardous, its use as a recultivation material can only be permitted after a detoxification.The main pollutants in the soil-like fraction are cadmium, copper, and nickel.

Keywords: landfills, soil-like fraction, heavy metals, pollution level

The algorithm and code listing of the developed self-learning chatbot are presented. Able to maintain a conversation with the user, switch to training mode in the absence of the necessary information, analyze the context of the conversation for "forbidden" words. The Trim function is used, which removes extraneous characters represented in the tr property. And also an additional option "Solve arithmetic problems" is implemented in case of a request from the user. When implementing the latter option, a recursive descent algorithm based on three nested recursive functions was used, while the binary tree is filled in. A function has been developed to divide the incoming string into tokens. The chatbot code is developed in C++/C# based on the principles of object-oriented programming with the development of classes.

Keywords: artificial intelligence, machine learning, voice assistant chatbot, learning mode, tokens, recursive descent, binary tree

The article confirms the need for a systematic approach to the scientific justification of the electronic document management systems security(EDMS) and the relevance of the study, presents the results of the analysis of guidance documents regarding the development of mathematical models and existing experience, summarizes the procedure for the scientific justification of EDMS security, highlights the main trends in modeling today, a new approach to the construction of EDMS security models is proposed, defines its role and place in the existing theory and practice.

Keywords: Security models of computer systems, security policy, electronic document management system, systematic approach

Despite the existing differentiation of the regions of the Russian Federation in terms of natural and climatic conditions and the level of socio-economic development, the main principle of the state cadastral valuation is aimed at the uniformity of its implementation. The study in this paper is aimed at revealing the concept of "regional features" as a factor leading to a discrepancy in the methodology for determining the cadastral value of real estate at the regional level. The article highlights the factors of regional specifics that form the features of the appraisal work to determine the cadastral value of land plots in 2022 on the territory of St. Petersburg and the Perm Territory, as well as recommendations for improving the existing unified methodology.

Keywords: state cadastral valuation, mass valuation, taxation, cadastral value, market value, differentiation of regions, regional peculiarity, real estate object, land plot