Feedback control of unstable cellular solidification fronts

We present a numerical and experimental study of feedback control of unstable cellular patterns in directional solidification (DS). The sample, a dilute binary alloy, solidifies in a 2D geometry under a control scheme which applies local heating close to the cell tips which protrude ahead of the other. For the experiments, we use a real-time image processing algorithm to track cell tips, coupled with a movable laser spot array device, to heat locally. We show, numerically and experimentally, that spacings well below the threshold for a period-doubling instability can be stabilized. As predicted by the numerical calculations, cellular arrays become stable, and the spacing becomes uniform through feedback control which is maintained with minimal heating.Comment: 4 pages, 4 figures, 1 tabl

Triple molybdates one-, one - and three(two)valence metals

The authors thank Ph. D. M. K. Alibaeva, Ph. D. I. A. Gudkova and Ph. D. I. V. Korolkova for participation in the research.The review summarizes experimental data on the phase formation, structure and properties of new complex oxide compounds group - triple molybdates containing tetrahedral molybdate ion, two different singly charged cation, together with tri- or divalent cation. The several structural families of these compounds were distinguished and it shown that many of them are of interest as luminescent, laser, ion-conducting or nonlinear optical materials.The work is executed at partial support of the Russian Foundation for basic research (projects No. 08-03-00384, 13-03-01020 and 14-03-00298)

Information support system for regional human resource development

In paper suggest a concept of information support system for human resource management at a regional level. We identify the main factors that affect quantitative and qualitative characteristics of regional human resource, including educational system, demographic and migration processes, and present a concept of the Program for its development. As a tool for information support of the Program propose a distributed information system with interfaces for various groups of users: regional administration, population and organization

New triple molybdate and tungstate Na5Rb7Sc2(XO4)9 (X = Mo, W)

New compounds of the composition Na5Rb7Sc2(XO4)9 (X = Mo, W) were obtained via the ceramic technology. The sequences of chemical transformations occurring during the formation of these compounds were established, and their primary characterization was performed. Both Na5Rb7Sc2(XO4)9 (X = Mo, W) were found to melt incongruently at 857 K (X = Mo) and 889 K (X = W). They are isostructural to Ag5Rb7Sc2(XO4)9 (X = Mo, W), Na5Cs7Ln2(MoO4)9 (Ln = Tm, Yb, Lu) and crystallize in the trigonal crystal system (sp. gr. R32). The crystal structures were refined with the Rietveld method using the powder X-ray diffraction data. The thermal expansion of Na5Rb7Sc2(WO4)9 was studied by high-temperature powder X-ray diffraction; it was shown that this triple tungstate belongs to high thermal expansion materials

Sistema de apoio à informação para o desenvolvimento de recursos humanos regionais

In this paper we suggest a concept of information support system for human resource management at a regional level. We identify the main factors that affect quantitative and qualitative characteristics of regional human resource, including educational system, demographic and migration processes, and present a concept of the Program for its development. As a tool for information support of the Program we propose a distributed information system with interfaces for various groups of users: regional administration, population and organizations. To assess the effectiveness of the activities of the Program we suggest a decision support system based on the agent model of regional human resource dynamics. The model reflects demographical situation in the region, migration flows, educational system, economy and social environment in the region and functions of the regional administration.En este documento, sugerimos un concepto de sistema de soporte de información para la gestión de recursos humanos a nivel regional. Identificamos los principales factores que afectan las características cuantitativas y cualitativas del recurso humano regional, incluidos el sistema educativo, los procesos demográficos y de migración, y presentamos un concepto del Programa para su desarrollo. Como herramienta para el soporte de información del Programa, proponemos un sistema de información distribuido con interfaces para varios grupos de usuarios: administración regional, población y organizaciones. Para evaluar la efectividad de las actividades del programa, sugerimos un sistema de apoyo a las decisiones basado en el modelo de agente de la dinámica regional de recursos humanos. El modelo refleja la situación demográfica en la región, los flujos migratorios, el sistema educativo, la economía y el entorno social en la región y las funciones de la administración regional.Neste artigo, sugerimos um conceito de sistema de suporte à informação para a gestão de recursos humanos em nível regional. Identificamos os principais fatores que afetam as características quantitativas e qualitativas dos recursos humanos regionais, incluindo o sistema educacional, os processos demográficos e de migração, e apresentamos um conceito do Programa para o seu desenvolvimento. Como ferramenta de apoio informacional ao Programa, propomos um sistema de informação distribuída com interfaces para vários grupos de usuários: administração regional, população e organizações. Para avaliar a eficácia das atividades do programa, sugerimos um sistema de apoio à decisão baseado no modelo de agente da dinâmica dos recursos humanos regionais. O modelo reflete a situação demográfica na região, os fluxos migratórios, o sistema educacional, a economia e o meio social da região e as funções da administração regional

DEVELOPMENT OF INTERNATIONAL BUSINESS IN THE CONTEXT OF GLOBALIZATION CHANGES

У статті проведено аналіз наслідків фінансової кризи для міжнародної торгівлі як однієї з форм міжнародного бізнесу. Виділено чотири основних способи підтримки міжнародної торгівлі фінансовим сектором, які демонструють прямий зв’язок між ними. Визначено, що вплив фінансових криз на міжнародний бізнес можна визначити опосередковано шляхом порівняння динаміки основних показників ключових економік світу (Китай, Велика Британія, США, Німеччина) та України як безпосереднього відображення платоспроможності суб’єктів міжнародного бізнесу. З огляду на це, на основі даних МВФ було проведено аналіз показників ВВП у поточних цінах, дефлятора ВВП, валового боргу сектору державного управління, чисельності населення, рівня безробіття, загального обсягу інвестицій, обсягу експорту та обсягів імпорту товарів та послуг. За результатами проведеного аналізу встановлено, що фінансова криза негативно вплинула на зростання економіки досліджуваних держав: міжнародний імідж чотирьох досліджуваних країн (США, Німеччина, Велика Британія, Китай та Україна) знизився. Такі тенденції негативно відображуються на розвитку міжнародного бізнесу цих держав. Установлено, що більшість із досліджуваних країн зазнала значних утрат економіки, їхній посткризовий період триває й донині. Проаналізувавши наслідки кризи та зробивши висновки з аналізу, можна сміливо стверджувати, що вона мала різнобічний вплив на фінансовий сектор та міжнародний бізнес. Окрім позитивних чинників, які у цілому може чинити міжнародна торгівля як прояв міжнародного бізнесу на фінансовий сектор, та навпаки, результати проведеного аналізу показників розвитку національної економіки провідних держав світу та України дали змогу виділити реальні наслідки фінансової кризи 2008 р

Risk-based Regulation of Russian Universities: Risk Indicators and Their Use for State Control Purposes

The article is devoted to the identification and analysis of indicators of the risk of low-quality education in Russian universities. In 2021-2022, the approach to higher education inspections has changed significantly: accreditation monitoring has been introduced, it includes eight indicators. However, this monitoring was formed by the expert community, so the results of its testing in practice have yet to be analyzed. The purpose of this work is to identify risk factors for estimation the likelihood of violations of mandatory requirements by universities, and to develop recommendations for expanding the set of risk indicators included in accreditation monitoring. The main methods used in the work are methods of quantitative analysis, including econometric modeling. The novelty of the work is determined by the approach used: risk indicators are identified using a quantitative econometric analysis of data on the observed characteristics and results of inspections of Russian universities in 2015-2019. The results of the study indicate the possibility of supplementing the set of accreditation monitoring indicators. As additional indicators, first of all, various characteristics of research activities of universities can be used. Such a change in accreditation monitoring will increase its effectiveness as a preliminary assessment tool used in the implementation of a risk-based approach to state control. In cases where the assessment of even extended monitoring is ambiguous, the quantitative model proposed by the authors can be used

Mathematical model of the competition life cycle under limited resources conditions: Problem statement for business community

Present study is devoted to the development of competition life cycle mathematical model in the closed business community with limited resources. Growth of each agent is determined by the balance of input and output resource flows: input (cash) flow W is covering the variable V and constant C costs and growth dA/dt of the agent's assets A. Value of V is proportional to assets A that allows us to write down a first order non-stationary differential equation of the agent growth. Model includes the number of such equations due to the number of agents. The amount of resources that is available for agents vary in time. The balances of their input and output flows are changing correspondingly to the different stages of the competition life cycle. According to the theory of systems, the most complete description of any object or process is the model of its life cycle. Such a model describes all stages of its development: from the appearance ("birth") through development ("growth") to extinction ("death"). The model of the evolution of an individual firm, not contradicting the economic meaning of events actually observed in the market, is the desired result from modern AVMs for applied use. With a correct description of the market, rules for participants' actions, restrictions, forecasts can be obtained, which modern mathematics and the economy can not give. © 2017 Author(s).15-06-04863Present study was carried out under financial support of the Russian Fund of Fundamental Research grant № 15-06-04863 "Mathematical models of local payment system lifecycles"

Magnetic properties of the antiferromagnetic spin-1/2 chain system β\beta-TeVO4_{4}

The magnetic susceptibility and magnetization of high quality single crystal beta-TeVO4 are reported. We show that this compound, made of weakly coupled infinite chains of VO5 pyramids sharing corners, behaves as a S = 1/2 one-dimensional Heisenberg antiferromagnet. From magnetic experiments we deduce the intrachain antiferromagnetic coupling constant J/kB = 21.4 $\pm$ 0.2 K. Below 5 K a series of three phase transitions at 2.26, 3.28 and 4.65 K is observed.Comment: Accepted for publication in Physical Review