The problem of developing alternative energy sources with high efficiency was posed back in the middle of the 20th century. One of the possible ways to solve it is the development of systems based on direct absorption solar collectors based on nanofluids. Systems of this kind are the most environmentally friendly and modern, the disadvantages of which include the complexity of maintenance and climatic restrictions of widespread use. The aim of this paper is to determine ways to increase the efficiency of heat transfer in systems for collecting and storing solar energy by means of mathematical modeling of heat and mass transfer processes in direct absorption solar collectors based on nanofluids. When constructing a mathematical model, the contributions of the diffusion and electrostrictive components were taken into account. A mathematical model of heat and mass transfer in a liquid-phase medium with nanoparticles under the action of a light field is investigated, taking into account one-dimensional concentration convection in the form of a boundary-value problem for a system of second-order partial differential equations. The reported study was funded by RFBR, project number 19-31-90070.

The problem of developing alternative energy sources with a high efficiency was raised in the middle of the 20th century. One of the possible ways to solve it is the development of systems based on direct absorption solar collectors based on nanofluids. Systems of this kind are the most environmentally friendly and modern, the disadvantages of which include the complexity of maintenance and climatic restrictions of widespread use. The purpose of this paper is to determine ways to improve the efficiency of heat transfer in solar energy collection and storage systems by means of mathematical modeling of heat and mass transfer processes in direct absorption solar collectors based on nanofluid. When constructing a mathematical model, the contributions of the diffusion and electrostrictive components were taken into account. A mathematical model of heat and mass transfer in a liquid-phase medium with nanoparticles under the influence of a light field has been studied. It takes into account one-dimensional concentration convection in the form of a boundary value problem for a system of second-order partial differential equations. An algorithm for the numerical simulation of such processes has been developed and implemented in software, the main element of which is a conservative finite-difference scheme of the second order of approximation. The effect of particle motion velocity and the effect of reflection of the light flux on the conditions for the processes of heat and mass transfer in a direct absorption solar collector has been numerically studied. The reported study was funded by RFBR, project number 19-31-90070. To carry out the calculations, the computing resources of the Center for Collective Use "Data Center of the Far Eastern Branch of the Russian Academy of Sciences" were used.

Fast Fourier transform is widely used to solve numerous scientific and engineering problems. In particular, this transform is behind the software dealing with speech and image recognition, signal analysis, modeling of properties of new materials and substances, etc. Newly emerging high-performance hybrid computing systems, as well as systems with alternative architectures, require research on discrete Fourier transform computation efficiency on these new platforms. The results of such research allow assessing the feasibility of certain solutions for building modern computing and data processing centers. This paper presents the results of such research covering modern hybrid computing systems based on the IBM POWER and Intel Xeon processors, as well as on NVIDIA Tesla co-processors. The analysis is carried out, and conclusions are presented on their performance when executing fast Fourier transforms. The impact of the existing architectural aspects of the hardware (CPU simultaneous multithreading mode, GPU data transfer bus, etc.) on the transform performance efficiency is assessed. The obtained results are used to provide recommendations on the optimal operation modes and settings of the considered mathematical libraries.

In recent years, taking into account the development of the needs of human society, a great need has arisen for the automation of various processes. To solve such problems, are used neural network technologies, which are attempts to reproduce the human nervous system, are actively gaining great popularity. In particular, neural networks are actively used in the tasks of classifying objects on images, and therefore, based on this, the task of developing new or modifying existing algorithms is relevant. This article presents an analysis of existing algorithms for using neural systems to classify objects in images, as well as technologies for constructing machine vision systems. An attempt is made to develop the architecture of a system for detecting objects on images, is capable of scaling both vertically and horizontally, which is characterized by sufficient accuracy and speed. Based on the developed architecture, a system for automating the process of classifying objects in images was developed. To give recommendations, a software module was developed that uses machine learning to identify the rules by which the class of the image object should be made. Neural models implementing the classification of objects in images were also configured and trained. The classification results are checked on a real data set, which is similar in composition of attributes to that which will be during production use of the system.

Information technology has affected almost all areas of human activity. The solution of increasingly complex technical problems leads to a constant complication of electronic devices by which these tasks are solved. For the normal operation of powerful semiconductor devices and high-performance computing systems, it is necessary to ensure their effective cooling. The possibility of using nanofluids to remove excess heat in such systems is one of the main reasons for the increased interest in them around the world. The approach used in this work to the study of properties and processes in nanofluids is based on the use of mathematical modeling methods. A mathematical model of heat and mass transfer in a liquid-phase medium with nanoparticles under the influence of a light field is studied taking into account one-dimensional concentration convection in the form of an initial-boundary-value problem for a system of nonlinear partial differential equations of the second order. A finite-difference algorithm for the numerical simulation of such processes is developed and software implemented. The results can be used in the development and study of effective methods for controlling heat transfer processes.

Nowadays people have to interact with huge amount of data. Recommender systems are all about help them with it. Particulaly, music listener often has large playlist and not each track he likes the same. This article describes a way to evaluate music rating based on implicit assessments.