This paper summarizes and continues the previous papers of the authors. We consider some models of optimization problems that arise when building large communication networks. The topology of the communication network is formalized by an undirected graph. The coordinates of the vertices of an undirected graph (nodes of the communication network) are usually set in advance in some way, and a set of edges must be constructed for this set of vertices. The main (and sometimes the only) goal, both of our previous articles and of this article, can be formulated as follows: for some special additional requirements, it is necessary to construct a set of edges of the graph that satisfies these requirements; these edges should have the minimum possible total length. Another important idea is to modify the standard algorithms for working with graphs in order to be able to consider dynamic models (when the input data changes slightly), and it should be possible to use the results of previous calculations when changing the input data. From the point of view of graph theory, all these problems have long been solved, but in practice, the implementation of the corresponding algorithms is fraught with great difficulties: first, in real conditions, we consider graphs consisting of several thousand vertices; second, as we have already noted, the construction of large communication networks usually involves a dynamic change in requirements. The consequence of the two circumstances given is that often even algorithms of quadratic complexity often cannot be applied. For each of our models of optimization problems, we present one or more possible algorithms (primarily heuristic ones) designed to solve it. Our proposed algorithms are usually iterative, and this fact fits well into the capabilities needed to build algorithms that work with dynamically changing data.

The saas.jinr.ru service is an attempt to simplify the usage of the JINR Multifunctional Information and Computing Complex (MICC) of the Joint Institute for Nuclear Research (JINR). It aims at providing a simple problem-oriented web-interface to help students and beginner researchers in the physics domain to abstract away the complexity of the computing infrastructure and to focus on the actual research. In this paper we show our approach to one of the problems within the scope of the project: interactive data visualization in a web-browser. When approaching this problem, we considered two major requirements to the system: first, users may not have any programming skills, so any interaction should be performed using simple visual components; second, the system must be horizontally scalable to cope with irregular user work-sessions. The paper describes how we used Bokeh and Dask for integrating our data visualization solution within the Django framework to deal with the first requirement, and the JINR cloud for service scaling. Application of cloud technologies facilitates dynamic distribution of workload across virtual machines, thus making it possible for us to control the balance between efficient hardware utilization and end-user experience. Shared in this work resulting software architecture and applied solutions, as well as some performance considerations, can be used as an example when designing other cloud-native scientific applications.

The article describes the development of a virtual research environment for solving the tasks of mathematical modeling of superconducting electronics and spintronics, which are intensively developing areas of condensed matter physics. Despite the ample capacities of existing software packages for numerical modeling of physical and technical systems, including the construction of models and visualization of calculation results, it is not always possible to study a specific physical problem, since many systems are not yet included in the packages, and many problems require specialized algorithms to solve them. The range of problems related to the study of systems based on Josephson junctions can serve as an example. The proposed virtual research environment combines convenient tools based on web technologies for building models and an interface, performing calculations on the HуbriLIT heterogeneous computing platform and visualizing calculation results, as well as provides different research groups with an environment for organizing joint studies, exchanging models and calculation results.

Bankruptcy prediction model is an issue that has consistently interested in various fields. Recently, as technology for dealing with unstructured data...

This article discusses issues surrounding the training of specialists in distributed information systems using innovative methods and technologies in a virtual computer lab environment with an integrated knowledge management system. The article clearly shows how complex knowledge, skills, and professional competencies should be taught to IT specialists. It provides a detailed exploration of the architecture of the Virtual Computer Lab (VCL) and describes the successful experience of using the VCL in classes taught by the Department of Systems Analysis and Control at the Dubna State University. The new practice with containers is different compared to hardware virtualization case and effectively complements it for a wide range of practical educational tasks dedicated to the mastering distributed information systems in a virtual computer lab. For the underlying operating system kernel can be used for all containers and improves payload on the north of a similar configuration. The article provides a detailed description of containerization technology to improve the efficiency of IT-training and features of container management in a distributed environment.

The paper discusses the problem of common transport system creation from system-wide positions. Much attention is focused on two aspects – active self-maintenance in the environment with disorganization and dual nature of an organized object – as a system and as an element of a super-system. These roles for transport are expressed in the presence of two main tasks, for the system it is «transportation», for the element of the national economy – «ensuring economic cooperation by reliable and efficient transport links». In the first case, losses in the interaction of transport and production are attributed to production, in the second – to transport. Therefore, in the latter case, transport has to adapt to the rhythms of production. Self-maintenance on transport is provided by adaptive, flexible, controlled operation. Controlling creates so-called dynamic reserves that replace the actual, static reserves. To organize the common transport system in a market economy conditions it is necessary to use «system integrators». Functions of the «system integrators» should be performed by forwarding companies. Methods of calculation and optimization should represent system properties of transport objects. For optimal control of traffic volume the paper proposes to use a dynamic transportation problem and a dynamic coordination method instead of a transport linear programming problem. The latter allows calculating not only the optimal modes of transportation, but also the adaptive coordination of production and consumption rhythms. These methods have been successfully applied in the empty car traffic volume control and in the calculation of the coordinated supply of goods to seaports. Simulation modeling is considered as the main method of calculation. Authors present two simulation systems: ISTRA for modeling railway stations and IMETRA for modeling transport junctions and large ranges. They have built-in mechanisms for representing the adaptive control. The optimization methods and modeling systems have passed state registration.

The current level of development of wireless devices makes it possible to use a cheap wireless interface in virtually all areas of electronics, where previously mainly wired solutions were used. Many objects additionally use a lot of wireless control and management devices, wireless relays, locks, video surveillance. Overlapping of frequency devices in open bands is widespread, these devices stop working for long distances or do not accept requests at all. The work is devoted to the study of Mesh networks with the traditional method of routing AODV and with the previously developed method based on PainlessMesh and software-configurable networks. As an object of research, IoT devices are used, used in large-scale objects. A study will be made of the loss of packets and the delay in the transmission of packets for both protocols under investigation.