On Computation of Groebner Bases for Linear Difference Systems

In this paper we present an algorithm for computing Groebner bases of linear ideals in a difference polynomial ring over a ground difference field. The input difference polynomials generating the ideal are also assumed to be linear. The algorithm is an adaptation to difference ideals of our polynomial algorithm based on Janet-like reductions.Comment: 5 pages, presented at ACAT-200

Inequality and Transformation of Social Structures in Transitional Economies

The transition to a market economy in Eastern Europe and the Former Soviet Union (FSU) has been associated with greater inequality and social stratification. Living standards have fallen for the majority of people, unemployment and poverty are high, the distribution of assets and earnings has changed radically, and social benefits have fallen. The social distance between the 'winners' and 'losers' of the reforms has widened dramatically. This paper prepared within the UNU-WIDER project on 'Income Distribution and Social Structure during the Transition' analyses trends in social stratification and their causes with the aim of drawing social policy conclusions. Social structures have been deeply affected by macroeconomic and social-sector reforms. Privatization shifted assets towards the wealthy while changes in labour markets have led to the rise in earnings inequality. In the pretransitional socialist societies which were stratified into 'status groups' where social capital rather than economic capital—and social networks rather than market power—determined a person's status. With the transition, people's prospects in life are being increasingly determined by their possession of assets, goods and income opportunities. This study considers emerging social classes and groups—a new elite—the product of rising capitalism, and the new commercial, managerial, and professional middle classes. The large majority of the population, however, consists of blue-collar workers, farmers, and state-sector employees bearing the social costs of the transition. The bottom of the social hierarchy has enlarged due to a considerable number of socially deprived and marginalized people who fell into long-term poverty. The slowly reforming economies of the FSU have particularly high inequality and social polarization. Central Europe's transition countries have shown smaller increases in income inequality. Many professional workers there, especially the young have successfully entered the market economy. In contrast, an extremely wealthy and powerful economic elite has emerged in Russia and some other FSU countries amidst impoverishment and deprivation of a large part of the population. Social polarization has large economic costs. Thus, a more active social policy—promoting better livelihoods and more investment in human capital—could have large economic returns. But there is also a need for more effective public transfers and income redistribution policies to alleviate and reduce poverty. Social cohesion cannot be ignored

Poverty Alleviation in the Course of Transition: Policy Options for Russia

Digitised version produced by the EUI Library and made available online in 2020

Kyrgyzstan A Case Study of Social Stratification

Kyrgyzstan is one of the poorer countries undergoing transition from a centrally planned to a market economy. Unlike its neighbour Uzbekistan, Kyrgyzstan followed a rather radical reform strategy, introduced liberal macroeconomic reforms and large-scale privatization. Having laid major foundations for a market economy these reforms have entailed high social costs and profound changes from largely egalitarian social structures to greater inequality and social stratification. Major social consequences of the transition include a decline in living standards for the majority, the appearance of unemployment, radical shifts in distribution of assets, increases in earnings inequality, changes in the welfare system associated with decline in major social benefits. These factors lead to re-ranking of relative income positions and social status of many social and professional groups. One of the most important outcomes has been increasing social distance between the 'winners' and 'losers' of the reforms.This paper analyses the process of social stratification and the social structure emerging in Kyrgyzstan in the course of transition. Macroeconomic policies, privatization, agrarian reforms and changes in social security regime are considered as determinants of social stratification together with other factors, such as social networks (the role of community and clan relationship), ethnicity, the strength and role of institutions.This paper further focuses on income inequality and examines transformation of the old and characteristics of the new social classes and groups: the new elite, the middle class and the poor. This analysis is based on original 1993 KPMS and 1997 LSMS data. One of the major conclusions of the study is that the country needs a strong income redistribution policies addressing the very high level of inequality and massive poverty which present a major challenge to successful transition and sustainable development

Comparison of prices depending on factors in the secondary housing market

The article considers the issue of pricing for the secondary real estate market regarding local causes (physical properties of housing). The aim of the study was to verify the following hypotheses: the influence of the pricing factors of residential real estate on its value is determined by its price segment and the influence of infrastructure on the value of apartments in different cities is the same. In the hypothesis test, data were used on the secondary housing market of the cities of Novosibirsk and Krasnoyarsk, taken from the site of «CIAN» apartment sale announcements and from various open data sources. During the study, non-parametric methods of machine learning, model-agnostic methods for the interpretation of predictive models, hierarchical clustering are involved. As a result of the work, the first hypothesis was confirmed and the second hypothesis was refuted, the high accuracy of forecasting the cost of an apartment was achieved, and the peculiarities of price formation for secondary housing objects were revealed and described

The Orb-Weaving Spider Algorithm for Training of Recurrent Neural Networks

The quality of operation of neural networks in solving application problems is determined by the success of the stage of their training. The task of learning neural networks is a complex optimization task. Traditional learning algorithms have a number of disadvantages, such as «sticking» in local minimums and a low convergence rate. Modern approaches are based on solving the problems of adjusting the weights of neural networks using metaheuristic algorithms. Therefore, the problem of selecting the optimal set of values of algorithm parameters is important for solving application problems with symmetry properties. This paper studies the application of a new metaheuristic optimization algorithm for weights adjustment—the algorithm of the spiders-cycle, developed by the authors of this article. The approbation of the proposed approach is carried out to adjust the weights of recurrent neural networks used to solve the time series forecasting problem on the example of three different datasets. The results are compared with the results of neural networks trained by the algorithm of the reverse propagation of the error, as well as three other metaheuristic algorithms: particle swarm optimization, bats, and differential evolution. As performance criteria for the comparison of algorithms of global optimization, in this work, descriptive statistics for metrics of the estimation of quality of predictive models, as well as the number of calculations of the target function, are used. The values of the MSE and MAE metrics on the studied datasets were obtained by adjusting the weights of the neural networks using the cycling spider algorithm at 1.32, 25.48, 8.34 and 0.38, 2.18, 1.36, respectively. Compared to the inverse error propagation algorithm, the cycling spider algorithm reduced the value of the error metrics. According to the results of the study, it is concluded that the developed algorithm showed high results and, in the assessment of performance, was not inferior to the existing algorithm

Structural and Electrocatalytic Properties of Platinum and Platinum-Carbon Layers Obtained by Magnetron-Ion Sputtering

This article is devoted to further development of magnetron sputtering technology for catalysts and catalysts layer production for fuel cells and other electrochemical devices. Platinum-carbon films with Pt content up to 95⁻97 wt % were deposited using different sputtering regimes—DC (direct current) sputtering with and without application of a pulse negative bias voltage to the titanium substrate and also bipolar pulse sputtering with frequency of 10 kHz and 100 kHz. Composite platinum carbon targets were used for sputtering. Characteristics of platinum-carbon films were compared with those of platinum films deposited using the same regimes. The main methods of investigation were scanning transmission electron microscopy (STEM) with energy dispersive X-ray spectroscopy; potentiostatic and potentiodynamic methods. The catalytic activity of platinum-carbon films increased with platinum content and at a platinum concentration of 95⁻97 wt % became higher than that of platinum films sputtered in the same regimes. It was proposed that carbon atoms deposited on the substrate limited the mobility of the deposited platinum species and inhibited Pt cluster growth. Platinum-carbon films produced by pulsed DC magnetron sputtering with pulsed frequency 100 kHz consisted of narrow Pt columns with dome nanotops forming a well-developed surface. The porosity and specific surface of these columnar nanopillar films were higher compared with those of pure platinum films deposited under the same conditions. Moreover, the platinum-carbon films deposited using a bipolar pulse regime with a frequency of 100 kHz had the highest specific surface, porosity (30%) and catalytic activity in hydrogen and oxygen evolution due to a high ion current density and reduced pulse duration which inhibited the growth of large platinum globules