75 research outputs found

    The Myth about Universal Higher Education: Russia in the International Context

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    This is the final version. Available from the National Research University Higher School of Economics (HSE) via the DOI in this recordIt is widely believed that higher education in Russia has become almost universal and more people go to universities compared to most European countries. In this paper we explore this issue empirically with the Russian and European census data and data from the Trajectories in Education and Careers (TREC), a longitudinal cohort study. According to the 2010 census, only 34% of people aged between 25 and 34 in Russia have university degrees, which is nearly the same as in most Eastern European countries and slightly fewer than in Western Europe. The TREC data show that only about 50% of 2012 ninthgrade graduates were university students in 2015. The expansion of higher education in Russia has been in line with the overall European trends. Similar to other countries, there have been changes to the gender composition of university students in Russia over the last two decades, with girls being more likely to attend university than boys. The analysis of social backgrounds of students with different educational trajectories reveals a considerable social inequality within the Russian education system. Eighty-four percent of school graduates with university-educated parents are admitted to university, as compared to only 32% of children from less-educated families. Graduation from ninth grade represents an educational fork that is crucial for inequality, as children from less socially advantaged families tend to opt for vocational education at this stage. Graduation from eleventh grade is a less important educational transition: at least 80% of high school students get admitted to university after graduating from 11th grade

    Deformation of geometry and bifurcation of vortex rings

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    We construct a smooth family of Hamiltonian systems, together with a family of group symmetries and momentum maps, for the dynamics of point vortices on surfaces parametrized by the curvature of the surface. Equivariant bifurcations in this family are characterized, whence the stability of the Thomson heptagon is deduced without recourse to the Birkhoff normal form, which has hitherto been a necessary tool.Comment: 26 page

    Numerical Simulation of Vortex Crystals and Merging in N-Point Vortex Systems with Circular Boundary

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    In two-dimensional (2D) inviscid incompressible flow, low background vorticity distribution accelerates intense vortices (clumps) to merge each other and to array in the symmetric pattern which is called ``vortex crystals''; they are observed in the experiments on pure electron plasma and the simulations of Euler fluid. Vortex merger is thought to be a result of negative ``temperature'' introduced by L. Onsager. Slight difference in the initial distribution from this leads to ``vortex crystals''. We study these phenomena by examining N-point vortex systems governed by the Hamilton equations of motion. First, we study a three-point vortex system without background distribution. It is known that a N-point vortex system with boundary exhibits chaotic behavior for N\geq 3. In order to investigate the properties of the phase space structure of this three-point vortex system with circular boundary, we examine the Poincar\'e plot of this system. Then we show that topology of the Poincar\'e plot of this system drastically changes when the parameters, which are concerned with the sign of ``temperature'', are varied. Next, we introduce a formula for energy spectrum of a N-point vortex system with circular boundary. Further, carrying out numerical computation, we reproduce a vortex crystal and a vortex merger in a few hundred point vortices system. We confirm that the energy of vortices is transferred from the clumps to the background in the course of vortex crystallization. In the vortex merging process, we numerically calculate the energy spectrum introduced above and confirm that it behaves as k^{-\alpha},(\alpha\approx 2.2-2.8) at the region 10^0<k<10^1 after the merging.Comment: 30 pages, 11 figures. to be published in Journal of Physical Society of Japan Vol.74 No.

    Networked buffering: a basic mechanism for distributed robustness in complex adaptive systems

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    A generic mechanism - networked buffering - is proposed for the generation of robust traits in complex systems. It requires two basic conditions to be satisfied: 1) agents are versatile enough to perform more than one single functional role within a system and 2) agents are degenerate, i.e. there exists partial overlap in the functional capabilities of agents. Given these prerequisites, degenerate systems can readily produce a distributed systemic response to local perturbations. Reciprocally, excess resources related to a single function can indirectly support multiple unrelated functions within a degenerate system. In models of genome:proteome mappings for which localized decision-making and modularity of genetic functions are assumed, we verify that such distributed compensatory effects cause enhanced robustness of system traits. The conditions needed for networked buffering to occur are neither demanding nor rare, supporting the conjecture that degeneracy may fundamentally underpin distributed robustness within several biotic and abiotic systems. For instance, networked buffering offers new insights into systems engineering and planning activities that occur under high uncertainty. It may also help explain recent developments in understanding the origins of resilience within complex ecosystems. \ud \u

    A Weakened Transcriptional Enhancer Yields Variegated Gene Expression

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    Identical genes in the same cellular environment are sometimes expressed differently. In some cases, including the immunoglobulin heavy chain (IgH) locus, this type of differential gene expression has been related to the absence of a transcriptional enhancer. To gain additional information on the role of the IgH enhancer, we examined expression driven by enhancers that were merely weakened, rather than fully deleted, using both mutations and insulators to impair enhancer activity. For this purpose we used a LoxP/Cre system to place a reporter gene at the same genomic site of a stable cell line. Whereas expression of the reporter gene was uniformly high in the presence of the normal, uninsulated enhancer and undetectable in its absence, weakened enhancers yielded variegated expression of the reporter gene; i.e., the average level of expression of the same gene differed in different clones, and expression varied significantly among cells within individual clones. These results indicate that the weakened enhancer allows the reporter gene to exist in at least two states. Subtle aspects of the variegation suggest that the IgH enhancer decreases the average duration (half-life) of the silent state. This analysis has also tested the conventional wisdom that enhancer activity is independent of distance and orientation. Thus, our analysis of mutant (truncated) forms of the IgH enhancer revealed that the 250 bp core enhancer was active in its normal position, ∼1.4 kb 3′ of the promoter, but inactive ∼6 kb 3′, indicating that the activity of the core enhancer was distance-dependent. A longer segment – the core enhancer plus ∼1 kb of 3′ flanking material, including the 3′ matrix attachment region – was active, and the activity of this longer segment was orientation-dependent. Our data suggest that this 3′ flank includes binding sites for at least two activators

    The self-organizing fractal theory as a universal discovery method: the phenomenon of life

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    A universal discovery method potentially applicable to all disciplines studying organizational phenomena has been developed. This method takes advantage of a new form of global symmetry, namely, scale-invariance of self-organizational dynamics of energy/matter at all levels of organizational hierarchy, from elementary particles through cells and organisms to the Universe as a whole. The method is based on an alternative conceptualization of physical reality postulating that the energy/matter comprising the Universe is far from equilibrium, that it exists as a flow, and that it develops via self-organization in accordance with the empirical laws of nonequilibrium thermodynamics. It is postulated that the energy/matter flowing through and comprising the Universe evolves as a multiscale, self-similar structure-process, i.e., as a self-organizing fractal. This means that certain organizational structures and processes are scale-invariant and are reproduced at all levels of the organizational hierarchy. Being a form of symmetry, scale-invariance naturally lends itself to a new discovery method that allows for the deduction of missing information by comparing scale-invariant organizational patterns across different levels of the organizational hierarchy

    APPLICATION OF INDUSTRIAL GAS TURBINE DIGITAL TWIN

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    The paper considers the concept of a digital twin of a technical device and the vision of this issue by various companies. The features of using digital twins of gas turbine plants are analyzed. The main goals and tasks to be solved by the digital twin of the gas turbine unit at the stage of operation are formulated.В работе рассмотрено понятие цифрового двойника технического устройства и видение настоящего вопроса различными компаниями. Проанализированы особенности применения цифровых двойников газотурбинных установок. Сформулированы основные цели и задачи, которые должен решать цифровой двойник газотурбинной установки на этапе эксплуатации
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