93 research outputs found

    Modern Integrated Associations: Comparative Analysis of Economic Growth Factors

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    In the article, the results of the research, which purpose is to ground and assess the factors of economic growth of regional integration communities and national economies of member countries that develop them, are presented. The foreign trade, mutual trade turnover, and domestic demand are allocated as such factors. The authors has applied the novelty in their methodology which in contrast to the traditional assessment method of growth factors of integration communities and their participants, is based on comparison of two components — external and domestic demand, based on dividing the external demand on two components: the first one is pure export (the difference between export and import is a component of cumulative demand) of goods in integration community, i.e. the pure export of mutual trade; the second one is a pure export of foreign trade of goods outside of the integration association. Scope of the research is seven most known regional integrated units arose at different times and being at different stages of development — the European Union, North American Free Trade Area, Association of Southeast Asian Nations, Southern American Common Market, Asia-Pacific Economic Cooperation, and also member countries of the Eurasian integration — the Customs Union and Common Free Market Zone developed into the Eurasian Economic Union in January 1, 2015. In conclusion, it is noted that the integration develops successfully only in the conditions of the rise in national economies of the participating countries. Crisis economies have to deal more with internal problems than to resolve integration issues.The article has been prepared within the project «Eurasian integration: asymmetries and efficiency» with financial support of the grant № 1275/GF4 of the Ministry of Education and Science of the Republic of Kazakhstan»

    Computer Architectures to Close the Loop in Real-time Optimization

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    © 2015 IEEE.Many modern control, automation, signal processing and machine learning applications rely on solving a sequence of optimization problems, which are updated with measurements of a real system that evolves in time. The solutions of each of these optimization problems are then used to make decisions, which may be followed by changing some parameters of the physical system, thereby resulting in a feedback loop between the computing and the physical system. Real-time optimization is not the same as fast optimization, due to the fact that the computation is affected by an uncertain system that evolves in time. The suitability of a design should therefore not be judged from the optimality of a single optimization problem, but based on the evolution of the entire cyber-physical system. The algorithms and hardware used for solving a single optimization problem in the office might therefore be far from ideal when solving a sequence of real-time optimization problems. Instead of there being a single, optimal design, one has to trade-off a number of objectives, including performance, robustness, energy usage, size and cost. We therefore provide here a tutorial introduction to some of the questions and implementation issues that arise in real-time optimization applications. We will concentrate on some of the decisions that have to be made when designing the computing architecture and algorithm and argue that the choice of one informs the other

    Global Dimension of Polynomial Rings in Partially Commuting Variables

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    For any free partially commutative monoid M(E,I)M(E,I), we compute the global dimension of the category of M(E,I)M(E,I)-objects in an Abelian category with exact coproducts. As a corollary, we generalize Hilbert's Syzygy Theorem to polynomial rings in partially commuting variables.Comment: 11 pages, 2 figure

    Software and hardware code generation for predictive control using splitting methods

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    This paper presents SPLIT, a C code generation tool for Model Predictive Control (MPC) based on operator splitting methods. In contrast to existing code generation packages, SPLIT is capable of generating both software and hardware-oriented C code to allow quick prototyping of optimization algorithms on conventional CPUs and field-programmable gate arrays (FPGAs). A Matlab interface is provided for compatibility with existing commercial and open-source software packages. A numerical study compares software, hardware and heterogeneous implementations of splitting methods and investigates MPC design trade-offs. For the considered testcases the reported speedup of hardware implementations over software realizations is 3x to 11x

    Nonlinear predictive control on a heterogeneous computing platform

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    Nonlinear Model Predictive Control (NMPC) is an advanced control technique that often relies on computationally demanding optimization and integration algorithms. This paper proposes and investigates a heterogeneous hardware implementation of an NMPC controller based on an interior point algorithm. The proposed implementation provides flexibility of splitting the workload between a general-purpose CPU with a fixed architecture and a field-programmable gate array (FPGA) to trade off contradicting design objectives, namely performance and computational resource usage. A new way of exploiting the structure of the Karush-Kuhn-Tucker (KKT) matrix yields significant memory savings, which is crucial for reconfigurable hardware. For the considered case study, a 10x memory savings compared to existing approaches and a 10x speedup over a software implementation are reported. The proposed implementation can be tested from Matlab using a new release of the Protoip software tool, which is another contribution of the paper. Protoip abstracts many low-level details of heterogeneous hardware programming and allows quick prototyping and processor-in-the-loop verification of heterogeneous hardware implementations

    Longitudinal vibrations of underground pipelines of finite length in medium surrounded by soil with different properties along pipeline length

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    An analysis of the dynamic response of an underground main pipeline under a longitudinal wave propagating in soil along the pipe is given in the article. The problem of the longitudinal wave impact on a pipeline of finite length, interacting with soil according to the elastic-viscous law, is considered. The ends of the pipeline are fixed to massive nodes that interact with the medium according to linear laws. Along the length of the pipeline, the coefficients of the elastic and viscous pipeline-soil interaction change depending on the coordinate. In this article, the influence of the coefficients of elastic and viscous interaction of the "pipe-soil" system is studied when these coefficients are coordinate functions. The variability of the values of the coefficients along the length of the pipeline leads to a change in displacements from 0 to 15% and strain from 0 to 18%, compared with the case when these coefficients are constant. Depending on the length of the pipeline, the response of the pipeline to seismic action is different. This is especially evident at the boundary points. Considering the weight of nodes leads largely to a decrease in the strain of the pipeline relative to the soil strain at the boundary points

    Theory of proximity effect in superconductor/ferromagnet heterostructures

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    We present a microscopic theory of proximity effect in the ferromagnet/superconductor/ferromagnet (F/S/F) nanostructures where S is s-wave low-T_c superconductor and F's are layers of 3d transition ferromagnetic metal. Our approach is based on the solution of Gor'kov equations for the normal and anomalous Green's functions together with a self-consistent evaluation of the superconducting order parameter. We take into account the elastic spin-conserving scattering of the electrons assuming s-wave scattering in the S layer and s-d scattering in the F layers. In accordance with the previous quasiclassical theories, we found that due to exchange field in the ferromagnet the anomalous Green's function F(z) exhibits the damping oscillations in the F-layer as a function of distance z from the S/F interface. In the given model a half of period of oscillations is determined by the length \xi_m^0 = \pi v_F/E_ex, where v_F is the Fermi velocity and E_ex is the exchange field, while damping is governed by the length l_0 = (1/l_{\uparrow} + 1/l_{\downarrow})^{-1} with l_{\uparrow} and l_{\downarrow} being spin-dependent mean free paths in the ferromagnet. The superconducting transition temperature T_c(d_F) of the F/S/F trilayer shows the damping oscillations as a function of the F-layer thickness d_F with period \xi_F = \pi/\sqrt{m E_ex}, where m is the effective electron mass. We show that strong spin-conserving scattering either in the superconductor or in the ferromagnet significantly suppresses these oscillations. The calculated T_c(d_F) dependences are compared with existing experimental data for Fe/Nb/Fe trilayers and Nb/Co multilayers.Comment: 13 pages, REVTeX4, 8 PS-figures; improved version, submitted to PR

    Layered ferromagnet-superconductor structures: the π\pi state and proximity effects

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    We investigate clean mutilayered structures of the SFS and SFSFS type, (where the S layer is intrinsically superconducting and the F layer is ferromagnetic) through numerical solution of the self-consistent Bogoliubov-de Gennes equations for these systems. We obtain results for the pair amplitude, the local density of states, and the local magnetic moment. We find that as a function of the thickness dFd_F of the magnetic layers separating adjacent superconductors, the ground state energy varies periodically between two stable states. The first state is an ordinary "0-state", in which the order parameter has a phase difference of zero between consecutive S layers, and the second is a "π\pi-state", where the sign alternates, corresponding to a phase difference of π\pi between adjacent S layers. This behavior can be understood from simple arguments. The density of states and the local magnetic moment reflect also this periodicity.Comment: 12 pages, 10 Figure
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