The subject matter of the article is the processes of synthesis of the information and telecommunication network (ITN) for solving applied problems of safety-critical systems (SCS). The goal is to develop a mathematical model for the optimal distribution of applied tasks of safety-critical systems over the ITN nodes. The tasks to be solved are: to formalize the procedure of distribution of applied tasks and SCS software over the ITN nodes; to develop a mathematical model of optimal distribution in order to minimize the cost of network resources; to select an effective algorithm for solving it. The methods used are: alternative-graph approach, mathematical optimization models, methods for solving nonlinear integer programming problems with Boolean variables. The following results were obtained: the task of selecting the ITN optimal structure was formulated according to the alternative-graph model of information processing; in addition to structural characteristics, the requirements for the parameters necessary for performing applied tasks were taken into account while constructing a mathematical model; when minimizing the cost of a computing resource, constraints related to the capabilities for financing the development and operation of the network are taken into account; the costs for organizing additional connections among the network nodes are considered as well. As a result, a mathematical model of distributing SCS applied problems over the ITN environment was obtained in order to minimize the total costs of computing resource, data transmission, network setting and maintenance. This model is a non-linear integer programming problem with Boolean variables. Taking into account the specific nature of the objective function and model constraints with the use of pseudo-Boolean functions, the original task is reduced to a linear form. The obtained model represents the canonical form of the linear optimizing problem of large-dimensional Boolean programming, for which the method of the recession vector is effective. Conclusions. The scientific novelty of the results obtained is as follows: 1) the optimization model of distributing applied tasks over the nodes of the computer network was improved by defining the objective function in order to minimize the costs of both computational and data transmission and the constraints caused by the requirements for the technical and information structure of the network; 2) methods for solving the problems of optimizing the ITN structure on the basis of models of nonlinear Boolean programming by transforming the initial task into a linear form and applying the recession vector method was further developed, which makes obtaining a quasi-optimal solution of the problem in the context of large dimension possible. K e ywor d s : information and telecommunication network; applied problems; optimal distribution; cost minimization; nonlinear model; Boolean variables.

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The subject matter of the study is the processes of planning supply logistics taking into account swings in demand and prices for products. The goal is to develop models and applied information technology for managing enterprise supplies taking into consideration the unforeseen demand swings. The following tasks were solved: a process model of supply logistics was developed, a model for forecasting demand for products was developed, a model for calculating the optimal volume of orders for various demand options was developed, the structure and modules of the applied information technology for supply logistics management was developed. The following methods were used: structural process models, methods for regression analysis and time series forecasting, inventory management models, STATISTICA software package, object-oriented programming methods. The following results were obtained: the generalized pattern of supply logistics was developed; the supplement of the first block of this pattern with the processes of marketing research of demand for products and planning supply volumes according to the forecasted demand and the probability of a shortage or surplus of products due to unforeseen swings in demand was substantiated; the application of the methods of regression analysis and forecasting of time series to assess the market factors of supply logistics was considered; the model for determining the optimal stock size was studied taking into account storage costs and probable shortages; the architecture of the applied information technology for planning supply logistics was developed; the proposed IT enables analyzing and predicting changes in the main market factors and, in accordance with the results obtained, solving inventory management tasks efficiently. In this case, the deficit and backordered demand can be taken into account. The operation of IT modules was illustrated by a test case. Conclusions. The use of IT is efficient in making decisions on logistics planning of business processes, as well as in analyzing the efficiency of logistics for a certain period of time. Further, the specified technology is going to be supplemented with the capabilities of solving inventory logistics problems.

The subject matter of the article is the processes of structural synthesis and parametric analysis of information and telecommunication networks (ITN). The aim is to develop the methodological apparatus which will enable obtaining ITN structural and technical parameters in order to ensure the operation of safety-critical systems (SCS), adaptive to external conditions and resistant to risks. The tasks to be solved are: to formulate principles and definition of the structure of the risk-adaptive management methodology of ITN SCS parameters; to determine the composition of the methodical apparatus and the applied means of the suggested methodology. General scientific methods used are: system analysis, structural and parametric synthesis, methods of decomposition and aggregation, methods of risk-adaptive management. The following results are obtained. The diagram of the main stages of ITN analysis is presented. In this case, the elements of the distributed architecture of ITN SCS are defined. The requirements for calculating the characteristics of the information and technical structures of the network are listed. The ways of fixing SCS applications at the functional nodes of the network are considered. The steps that are performed at the stage of solving the task of network setting are defined. The stage of matching task settings and operational management is a part of adaptive control. The above steps of analysis, synthesis and management of ITN are the basis of the structure of the risk-adaptive ITN SCS management methodology, which includes the following elements: principles, models, methods, and applied means. The methodology is based on the principles of decomposition, matching of goals and coordination of management, stream analysis and modeling of processes, adaptive and risk-based management. The composition and peculiarities of models (mathematical and systemic) and methods which are the basis of the methodical apparatus are determined. The applied part of the methodology is implemented by the information technology of adaptive management of distribution of network traffic. On ITN basis, the problem of interaction of technical and software means in the management of traffic distribution and organization of collecting, processing and transmitting information in the management system is solved. Adaptive management is provided by solving the tasks of setting the mode. Risk orientation is represented by two contours of feedback, which involves assessment and risk management at the stages of structural and parametric synthesis and distribution of network traffic. Conclusions. The implementation of the suggested methodology for ITN synthesis and management will enable the operation of SCS that is adaptive to external conditions and risk-resistant, which contributes to the improvement of the system safety.

The subject of the study in the article is methods and tools for the creation and implementation of distance learning systems (DLS). The interactive capabilities used in the distance education system, programs and information delivery systems allow for feedback, dialogue and ongoing support that are not possible in most traditional learning systems. The purpose of the article is to create a collaborative environment for developing software products in the system of distance learning by forming an interactive platform with the help of Sphere Engine, which provides the ability to debug the code in many programming languages. At the same time, the following tasks are solved: a review and comparison of existing systems of distance learning; analysis of the functional and features of the Sphere Engine platform; development of the integration algorithm of the service with the system Moodle. Methods: methods of information processing, methods and information technologies for the creation of electronic distance learning courses. Results. As a result of the review and comparison of existing distance learning systems and software verification tools, the tools that best meet the needs for collaborative development environments, namely the Moodle DLS and the Sphere Engine service, are selected. The analysis of the functional and features of the Sphere Engine platform is carried out: a diagram of the work of the api compilers of the service is shown, which illustrates the process of execution of the program from the moment of its sending to the results of execution; The concept of a pool script in graphical form is provided. A prototype collaborative development environment created in the form of a web application is created, the prototype architecture is described. An algorithm for integration of the Sphere Engine service with the Moodle system is developed. In detail, the stages of the integration algorithm are considered on the example of testing the work environment of the development of the course "Web-technologies and web-design". Conclusions. An interactive module is created with the help of Sphere Engine, which allows you to perform laboratory work on programming disciplines and to carry out full control over their execution. Thus, the degree of automation of the educational process in institutions of higher education increases.