Within the framework of hydrodynamic description, the dynamics of nonlinear cylindrical Langmuir waves has been studied for an isothermal plasma where ions form a stationary background. The problem is considered in the electrostatic formulation for two-dimensional geometry. Using a partial, exact solution for the equations of hydrodynamics, a system of differential equations describing the dynamics of electrons with the finite temperature is obtained. In these calculations, a parabolic on radius, concave temperature profile associated with an electron density changing only in time was used. In the framework of this model, the influence of initial conditions and thermal effects on the regular dynamics of excited waves and the development of hydrodynamic singularities in the electron beam is discussed. Estimates are obtained that specify the permissible range of plasma parameters at which either regular wave behavior is realized or the electron wave breaks down. It is shown that the development of singular behavior due to the intrinsic nonlinearity can be avoided by taking into account the thermal effects and the initial rotation of electron beam. These results may be useful for establishing the mechanisms of nonequilibrium energy/momentum transfer in plasma media with finite electron and ion temperatures.

Estimations specifying the admissible range of plasma parameters are derived

The generalized Gerdjikov–Ivanov equation is considered. In recent years, this equation has been intensively studied, since this equation is used to describe pulse propagation in optical fiber. Unlike the classical Gerdjikov–Ivanov equation, the equation under study does not pass the Painlevé test and the Cauchy problem for this equation cannot be solved by the inverse scattering method. This version of the Gerdjikov –Ivanov equation has only a limited number of conservation laws. Using multipliers and direct calculations, conservation laws for the equation under consideration are constructed in this paper and two conservation laws are found without restrictions on the parameters of the equation. One more additional conservation law is found under an additional restriction on the parameters of the equation. In this paper, first integrals for ordinary differential equations are also obtained by reducing the conservation laws to the variables of a traveling wave in the generalized Gerdjikov–Ivanov equation. Analytical solutions of the equation under consideration are found. Exact solutions of the generalized Gerdjikov–Ivanov equation are presented in the form of optical solitons, as well as through the Jacobi elliptic functions. Using auxiliary integrals, conserved quantities for an optical soliton are calculated. Conservative densities correspond to physical quantities: power, momentum, and energy. The obtained conserved quantities are of practical use in numerical and neural network modeling of pulse propagation processes in optical fiber.

The nonlinear Schrödinger equation of a general form is investigated, in which the chromatic dispersion and the potential are given by two arbitrary functions. The equation under consideration is a natural generalization of a wide class of related nonlinear equations that are often encountered in various sections of theoretical physics, including nonlinear optics, superconductivity, and plasma physics. Exact solutions of the nonlinear Schrödinger equation of general form are found, which are expressed in quadratures. One-dimensional non-symmetry reductions are described, which reduce the studied partial differential equation to simpler ordinary differential equations or systems of such equations. Special attention is paid to equations whose dispersion is given by a power function. The exact solutions obtained in this work can be used as test problems intended to assess the accuracy of numerical methods for integrating nonlinear equations of mathematical physics.

The article provides a group analysis of nonlinear second-order partial differential equations that model the propagation of shear waves in a nonlinear elastic cylindrical shell interacting with an external elastic medium. The equations contain cubic nonlinearity and generalize the well-known models of Lin – Reissner – Tsian and Khokhlov – Zabolotskaya. Their classical symmetries are found using a universal algorithm of commutative algebra, which consists of constructing a Gröbner basis of a system of defining equations to find the explicit form of the generating function of the symmetry group. To construct solutions that are invariant under a group of shifts in the space of independent variables, the hodograph method was used, which made it possible to move from a nonlinear partial differential equation to a system of linear equations with variable coefficients. For the self-similar regime, invariant under extensions, a nonlinear equation is obtained, the linear part of which is exactly solved in terms of Bessel functions and trigonometric functions. The conditions necessary for the physical realizability of exact solutions are established.

In the rapidly evolving field of software development, companies are increasingly using the DevOps paradigm to improve speed and quality. However, managing DevOps processes comes with significant challenges. Although the Project Management Body of Knowledge (PMBOK) provides industry-independent best practices, there is a gap in understanding the feasibility of achieving its success factors in DevOps projects. The purpose of the study is to identify key success factors in IT DevOps project management that are considered important but are not always realized in practice. A questionnaire survey was conducted using fuzzy set theory and fuzzy hierarchy analysis method to solve multi-criteria decision making problems. The analysis resulted in a ranked list of actions, with two groups: actions that are neglected and actions that are given more attention than required. These results indicate inconsistencies between recognized success factors and actual management practices. Addressing these mismatches is critical to improving DevOps project management efficiency, optimizing resource allocation, and improving project success rates. These findings provide a basis for developing strategies that better integrate PMBOK principles into DevOps processes.

A promising system for creating new-generation biosensors is a solid-state pore whose size is comparable to the size of a molecule under study. The essence of particle detection and analysis consists in registration of ionic currents flowing through the pore. At the moment when a molecule of the investigated object penetrates the pore, the current value changes depending on the size and shape of the particle. Consequently, the scale of these changes can be a sign that allows detection of certain particles. Interpretation of the results of experiments on measuring the volt-ampere characteristics (VAC) of nanopores is a complex problem, one of the solutions of which can be the creation of a numerical model of a solid-state nanopore. The paper presents the creation of a mathematical model of the studied samples of solid-state pores in silicon nitride membrane in COMSOL MultiPhysics® program. The process of ionic current flow through pores of different diameters has been modeled and the corresponding VACs have been obtained. To verify the model, a method of measuring the VAC of real membrane samples has been created, which has been worked out during a number of experiments on measuring the VAC of samples with pores of 1–57 microns and 55–140 nm in diameter. It is found that the deviation of the modeling results from the experimental results is of the order of 30 % for measurements of pores with diameters smaller than 70 nm and does not exceed 10–15 % in other cases. The work shows the response of the system to the transmission of gold nanoparticles with a diameter of 40 nm. There are no full-scale works on creation of similar mathematical models of solid-state pores and their measurement in Russia. This work can serve as a starting point for a large series of experiments on the measurement of solid-state nanopores.

The negative dynamics of the incidence of cancer gives high importance and relevance to the task of improving the effectiveness of diagnostic methods. Worldwide, more than 10 million cases of pathology are detected annually including 2.2 million cases of lung cancer of which 1.8 million cases are fatally. Early differential and accurate diagnosis of the disease is traditionally considered an important task of medicine. The aim of the work is to create an automated system for processing the results of objective control for the differential diagnosis of malignant neoplasms in the chests and to increase the accuracy and speed of diagnosis with its help. The resulting product is an artificial intelligence system based on a neural network that analyzes images and their multiple classification. Image analysis allows not only record the absence of presence of malignant neoplasms but also in the latter case to make a differential diagnosis of adenocarcinoma, large cell carcinoma and squamous cell lung cancer. The results of this product significantly exceed the achievements of other systems described and currently available the resulting product has an error of 3.5 % while the error of existing analogues is at least 7.1 % which is twice the error of the resulting system. The proposed product makes it possible to reduce the number of incorrectly diagnosed diagnoses by 2 times compared to currently existing analogues which is a significant achievement.

The construction industry is actively implementing digital solutions to support the technological processes
of construction and assembly works (C&I). Especially relevant is the digitalization of executive documentation
production. Modern standards and regulations already describe recommendations for information systems of
electronic document management at construction sites, as well as the characteristics that the documentation should
have in digital form. However, they do not regulate the stages of construction control inspections when forming
sets of executive documentation. Due to the technical demand, the information system of executive documentation
should be flexible and universal for application to any type of construction object. The development of a digital tool
requires complex analytics on unification of construction control business processes, which represents the objective
of this paper. In the study, the authors reviewed regulatory resources describing the requirements for conducting
key acceptance activities on capital construction projects, namely incoming, surveying, operational and acceptance
inspections. A taxonomy of construction and assembly activities has been compiled, for which unified groups of
control procedures are applicable. A set of standardized business processes was developed using the method of
graphical simulation. The means of system analysis were used to determine responsible executors and deadlines for
inspection activities. The paper concludes with a description of current limitations for digitalization of development
and maintenance of executive documentation.

А number of fusion installations and stands are currently used in Russia in the course of research in the field of controlled thermonuclear fusion. These scientific studies are of great importance for the development of the national program on plasma physics and in the active phases of their implementation require modern means of automated information support (for example, ensuring timely regulated access to computing facilities for calculations). The presence of a unified IT-platform is also required for interaction with colleagues, as well as access to scientific news, regulatory information and reference, events and other thematic agendas. Thus, the task of creating unified, modern IT-solution that would provide information exchange on research topics through a web interface is extremely urgent. A unique domestic infrastructural hardware platform of the common IT-space for fusion research (FusionSpace.RU) is being developed in Russia, which includes a number of functional capabilities for obtaining data from fusion installations and stands for the following display and analysis. This paper summarizes the creation of a portal for information exchange as a unified interface for interaction between researchers of the Russian fusion community. Basic problems and architecture were defined, and technologies for their implementation were selected and tested in the course of this work. The solutions considered provide the possibility of information interaction of participants of the Russian fusion community within an IT-platform of FusionSpace.RU. Conclusions are presented based on the results of the study.