Finite element modeling of the upsetting of an anisotropic cylindrical workpiece

Anisotropic material deformation is modeled with the application of the finite element method. Hill's yield criterion is used for simplified conditions of the upsetting process. The largest flow stress direction is determined to be parallel to all the three coordinate axes by turns. It is discovered that the base of the cylinder can take an oval shape when the flow stress directions of various values lie in the base plane. In this case, the smaller axis of the oval corresponds to the largest flow stress direction. When the flow stress directions of various values lie in the longitudinal section plane of the workpiece, its shape remains cylindrical. The deformation load is higher in this case. © 2017 Author(s)

Annihilation of edge dislocations in smectic A liquid crystals

This paper presents a theoretical study of the annihilation of edge dislocations in the same smectic plane in a bulk smectic-A phase. We use a time-dependent Landau-Ginzburg approach where the smectic ordering is described by the complex order parameter psi( r--> ,t) =eta e(iphi) . This quantity allows both the degree of layering and the position of the layers to be monitored. We are able to follow both precollision and postcollision regimes, and distinguish different early and late behaviors within these regimes. The early precollision regime is driven by changes in the phi ( r--> ) configuration. The relative velocity of the defects is approximately inversely proportional to the interdefect separation distance. In the late precollision regime the symmetry changes within the cores of defects also become influential. Following the defect collision, in the early postcollision stage, bulk layer order is approached exponentially in time. At very late times, however, there seems to be a long-time power-law tail in the order parameter fluctuation relaxation

Evaluating the flow stress of electrical steel under cold rolling in terms of the strain-rate hardening effect

The flow stress of the Fe+3%Si electrical steel under actual cold rolling conditions is evaluated on the basis of the approximation of the existing data on the work hardening and strain-rate hardening of this steel during cold tensile testing. It has been discovered that ductility is significant during electrical steel cold rolling and, besides, that its value is lower for large strains and strain rates than for low strains and strain rates. © 2016 Author(s)

Design of a socio-economic processes monitoring system based on network analysis and big data

Socio-economic policy should satisfy the interests of the society as much as possible and contribute to improving the quality of life. This actualizes the role of developing the theoretical and methodological foundations for building an innovative information system for monitoring the socio-economic situation and population responses. The study built and tested an algorithm for supporting management decisions based on the collection of large data sets of socio-economic information based on the principles of the digital economy and processing them through network analysis. The algorithm is focused on building a monitoring system that presupposes a synergy of the authorities and the society, not only in its pensionary part, but also among the masses, which are diverse in their representativeness. The result of the study was the formation of a theoretical and methodological framework for creating a system for making management decisions and assessing the effectiveness of the activities of government bodies, based on the principles of reflection of the final beneficiaries of economic policy.peer-reviewe

The growth of the digital retail services market in a down economy: problems and prospects

Rapid developments of information technologies and transition to the digital national economy require consumers and business communities to reconsider their behavior patterns. In this case the past 2020 served as a digitization catalyst. The authors proceed with the research of the digital services market and its segments. In the framework of the study, of particular interest is the digital retail services market development in a down national economy in 2020, caused by the new Covid-19 coronavirus infection pandemic. Retail services market is a promising and the most important market segment, integrated into a weekly human life cycle providing goods on the B2C market. The aim of the research is to reveal trends in the digital retail services development in a down economy and to identify the priority areas for this digital market segment development in the medium term. The research objectives are to consider the development trends of online stores and the relevance of marketplaces and mobile applications in the conditions of changing consumer behavior patterns, to identify which prospects of retail development to target in the context of national digitization. The methodological basis of the research comprises analysis, grouping and comparison. The forced change in the consumer behavior patterns and the introduction of a number of restrictions for entrepreneurs have led to changes in the entire retail market landscape and a shift to the digital segment. Additionally, the business community has also changed. A number of retail businesses were forced to withdraw from the market as it was impossible to carryout their activities under new conditions

STRAIN CHARACTERISTICS OF SOILS AND THE METHODS OF THEIR DETERMINATIO

A method is proposed for determining the strain characteristics of soils under dynamic loads, based on the results of experiments on dynamic compression of soils in laboratory conditions on a device of dynamic loading and for solving a wave problem, the statement of which is identical to the statement of the experiment. With the proposed method, the dynamic and static compression moduli, the unloading modulus, the viscosity coefficient of loess soil in the range of seismic loads were determined in accordance with the elastic-viscoelastic soil model developed by G.M. Lyakhov

NbS3_{3}: A unique quasi one-dimensional conductor with three charge density wave transitions

Through transport, compositional and structural studies, we review the features of the charge-density wave (CDW) conductor of NbS$_{3}$ (phase II). We highlight three central results: 1) In addition to the previously reported CDW transitions at $T_{P1}$ = 360\,K and $T_{P2}$ = 150\,K, another CDW transition occurs at a much higher temperature $T_{P0}$ = 620-650\,K; evidence for the non-linear conductivity of this CDW is presented. 2) We show that CDW associated with the $T_{P2}$ - transition arises from S vacancies acting as donors. Such a CDW transition has not been observed before. 3) We show exceptional coherence of the $T_{P1}$-CDW at room-temperature. Additionally, we report on the effects of uniaxial strain on the CDW transition temperatures and transport.Comment: 16 pages, 18 figure

Detailed study of dissipative quantum dynamics of K-2 attached to helium nanodroplets

We thoroughly investigate vibrational quantum dynamics of dimers attached to He droplets motivated by recent measurements with K-2 [1]. For those femtosecond pump-probe experiments, crucial observed features are not reproduced by gas phase calculations but agreement is found using a description based on dissipative quantum dynamics, as briefly shown in [2]. Here we present a detailed study of the influence of possible effects induced by the droplet. The helium droplet causes electronic decoherence, shifts of potential surfaces, and relaxation of wave packets in attached dimers. Moreover, a realistic description of (stochastic) desorption of dimers off the droplet needs to be taken into account. Step by step we include and study the importance of these effects in our full quantum calculation. This allows us to reproduce and explain all major experimental findings. We find that desorption is fast and occurs already within 2-10 ps after electronic excitation. A further finding is that slow vibrational motion in the ground state can be considered frictionless.Comment: 17 pages, 5 figure

МЕХАНИЗМ УПРАВЛЕНИЯ БАНКОВСКИМИ РИСКАМИ (КИБЕРНЕТИЧЕСКИЙ ПОДХОД)

The establishment of a flexible and dynamic bank risk management system is a crucial condition for a stable and profitable operation of banks. The risk management system of a commercial bank is understood both in the broad and narrow sense. In the broad sense, the banking risk management system is viewed upon as the following set of components: international risk management standards and adopting institutions; the state regulation of monetary relations including the monetary policy; the central bank activities; mechanisms of state supervision and control of the activities of lending institutions as well as other measures that may have a direct or an indirect impact on the state of the banking system. In the narrow sense, the risk management system means a system of regulation and supervision of the central bank activities based on federal laws, rules and regulations as well as organizational structures and risk management mechanisms used by commercial banks. The formal difference between the banking risk management mechanism and the risk management system is that the former has a particular object and management tools. The risk management mechanism consists of several levels: international, national and intra-bank. It includes the following interrelated elements: governance, risk management mechanism tools, information, resource, management object. Based on the research findings, the paper presents the structure of the bank risk management mechanism, describes its elements and defines the main objectives to be achieved with the management mechanism.Формирование гибкой и динамичной системы управления банковскими рисками является одним из главнейших условий стабильного и прибыльного функционирования банков. В статье система управления рисками в коммерческом банке понимается как в широком, так и узком смысле. В широком смысле под системой управления банковскими рисками понимается следующая совокупность элементов: международные стандарты по управлению рисками и организации, их принимающие, государственное регулирование денежно-кредитных отношений, включая денежно-кредитную политику, деятельность Центрального банка, механизмы государственного надзора и регулирования за деятельностью кредитных организаций, а также иные меры, которые прямо или косвенно могут повлиять на состояние банковской системы. В узком смысле под системой управления рисками понимается система регулирования и надзора за банковской деятельностью Центрального банка на основе федеральных законов, нормативов и постановлений, а также организационные структуры и механизмы управления рисками в коммерческих банках. Формальным отличием механизма управления банковскими рисками от системы управления рисками заключается в наличии конкретного объекта и инструментария для управления. Механизм управления рисками состоит из нескольких уровней: международного, национального и внутрибанковского. Включает следующие взаимосвязанные элементы: управленческие, инструментарий механизма управления рисками, информационные, ресурсные, объект управления. В результате исследования в статье представлена структура механизма управления банковскими рисками, дана характеристика его элементов, определены главные задачи механизма управления