562 research outputs found

    A description of a system of programs for mathematically processing on unified series (YeS) computers photographic images of the Earth taken from spacecraft

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    A description of a batch of programs for the YeS-1040 computer combined into an automated system for processing photo (and video) images of the Earth's surface, taken from spacecraft, is presented. Individual programs with the detailed discussion of the algorithmic and programmatic facilities needed by the user are presented. The basic principles for assembling the system, and the control programs are included. The exchange format within whose framework the cataloging of any programs recommended for the system of processing will be activated in the future is displayed

    Metastability of (d+n)-dimensional elastic manifolds

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    We investigate the depinning of a massive elastic manifold with dd internal dimensions, embedded in a (d+n)(d+n)-dimensional space, and subject to an isotropic pinning potential V(u)=V(u).V({\bf u})=V(|{\bf u}|). The tunneling process is driven by a small external force F.{\bf F}. We find the zero temperature and high temperature instantons and show that for the case 1d61\le d\le 6 the problem exhibits a sharp transition from quantum to classical behavior: At low temperatures T<TcT<T_{c} the Euclidean action is constant up to exponentially small corrections, while for T>Tc,T> T_{c}, SEucl(d,T)/=U(d)/T.{S_{\rm Eucl}(d,T)}/{\hbar} = {U(d)}/{T}. The results are universal and do not depend on the detailed shape of the trapping potential V(u)V({\bf u}). Possible applications of the problem to the depinning of vortices in high-TcT_{c} superconductors and nucleation in dd-dimensional phase transitions are discussed. In addition, we determine the high-temperature asymptotics of the preexponential factor for the (1+1)(1+1)-dimensional problem.Comment: RevTeX, 10 pages, 3 figures inserte

    Free-energy distribution functions for the randomly forced directed polymer

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    We study the 1+11+1-dimensional random directed polymer problem, i.e., an elastic string ϕ(x)\phi(x) subject to a Gaussian random potential V(ϕ,x)V(\phi,x) and confined within a plane. We mainly concentrate on the short-scale and finite-temperature behavior of this problem described by a short- but finite-ranged disorder correlator U(ϕ)U(\phi) and introduce two types of approximations amenable to exact solutions. Expanding the disorder potential V(ϕ,x)V0(x)+f(x)ϕ(x)V(\phi,x) \approx V_0(x) + f(x) \phi(x) at short distances, we study the random force (or Larkin) problem with V0(x)=0V_0(x) = 0 as well as the shifted random force problem including the random offset V0(x)V_0(x); as such, these models remain well defined at all scales. Alternatively, we analyze the harmonic approximation to the correlator U(ϕ)U(\phi) in a consistent manner. Using direct averaging as well as the replica technique, we derive the distribution functions PL,y(F){\cal P}_{L,y}(F) and PL(F){\cal P}_L(F) of free energies FF of a polymer of length LL for both fixed (ϕ(L)=y\phi(L) = y) and free boundary conditions on the displacement field ϕ(x)\phi(x) and determine the mean displacement correlators on the distance LL. The inconsistencies encountered in the analysis of the harmonic approximation to the correlator are traced back to its non-spectral correlator; we discuss how to implement this approximation in a proper way and present a general criterion for physically admissible disorder correlators U(ϕ)U(\phi).Comment: 16 pages, 5 figure

    Thermally activated Hall creep of flux lines from a columnar defect

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    We analyse the thermally activated depinning of an elastic string (line tension ϵ\epsilon) governed by Hall dynamics from a columnar defect modelled as a cylindrical potential well of depth V0V_{0} for the case of a small external force F.F. An effective 1D field Hamiltonian is derived in order to describe the 2D string motion. At high temperatures the decay rate is proportional to F5/2T1/2exp[F0/FU(F)/T],F^{{5}/{2}}T^{-{1}/{2}} \exp{\left [{F_{0}}/{F}-{U(F)}/{T}\right ]}, with F0F_{0} a constant of order of the critical force and U(F) \sim{\left ({\epsilon V_{0}})}^{{1}/{2}}{V_{0}/{F}} the activation energy. The results are applied to vortices pinned by columnar defects in superclean superconductors.Comment: 12 pages, RevTeX, 2 figures inserte

    NONPROCEDURAL SYNTHESIS OF SCENARIOS OF PROFESSIONAL TRAINING OF ERGATIC SYSTEM OPERATORS

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    Предлагается технология непроцедурного синтеза сценариев профессиональной подготовки операторов эргатических систем. Применение функционально-целевого подхода обеспечивает формальный синтез на основе концептуальной модели сценариев профессиональной подготовки, в структурно-алгоритмической организации которых отражена структура предметной области. Такой подход позволяет осуществить рационально обоснованный синтез сценариев профессиональной подготовки с точки зрения целей функционирования эргатической системыThe study is aimed at developing information technology to support the nonprocedural synthesis of scenarios for professional training of ergatic system operators. The application of the functionally-targeted approach provides a formal basis for synthesis based on the conceptual model of professional training scenarios which structural-algorithmic organization reflects the structure of the domain. This approach allows for rationally justified synthesis and choice of scenarios of professional training from the perspective of ergatic system operation goal

    Marginal Pinning of Quenched Random Polymers

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    An elastic string embedded in 3D space and subject to a short-range correlated random potential exhibits marginal pinning at high temperatures, with the pinning length Lc(T)L_c(T) becoming exponentially sensitive to temperature. Using a functional renormalization group (FRG) approach we find Lc(T)exp[(32/π)(T/Tdp)3]L_c(T) \propto \exp[(32/\pi)(T/T_{\rm dp})^3], with TdpT_{\rm dp} the depinning temperature. A slow decay of disorder correlations as it appears in the problem of flux line pinning in superconductors modifies this result, lnLc(T)T3/2\ln L_c(T)\propto T^{3/2}.Comment: 4 pages, RevTeX, 1 figure inserte

    Quantum depinning of a pancake-vortex from a columnar defect

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    We consider the problem of the depinning of a weakly driven (FFcF\ll F_{c}) pancake vortex from a columnar defect in a Josephson-coupled superconductor, where FF denotes the force acting on the vortex (FcF_{c} is the critical force). The dynamics of the vortex is supposed to be of the Hall type. The Euclidean action SEucl(T)S_{Eucl}(T) is calculated in the entire temperature range; the result is universal and does not depend on the detailed form of the pinning potential. We show that the transition from quantum to classical behavior is second-order like with the temperature TcT_{c} of the transition scaling like F4/3.F^{{4}/{3}}. Special attention is paid to the regime of applicability of our results, in particular, the influence of the large vortex mass appearing in the superclean limit is discussed.Comment: 11 pages, RevTeX, 4 figures inserte

    Chemostratigraphy of Neoproterozoic carbonates: implications for 'blind dating'

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    The delta C-13(carb) and Sr-87/Sr-86 secular variations in Neoproteozoic seawater have been used for the purpose of 'isotope stratigraphy' but there are a number of problems that can preclude its routine use. In particular, it cannot be used with confidence for 'blind dating'. The compilation of isotopic data on carbonate rocks reveals a high level of inconsistency between various carbon isotope age curves constructed for Neoproteozoic seawater, caused by a relatively high frequency of both global and local delta C-13(carb) fluctuations combined with few reliable age determinations. Further complication is caused by the unresolved problem as to whether two or four glaciations, and associated negative delta C-13(carb) excursions, can be reliably documented. Carbon isotope stratigraphy cannot be used alone for geological correlation and 'blind dating'. Strontium isotope stratigraphy is a more reliable and precise tool for stratigraphic correlations and indirect age determinations. Combining strontium and carbon isotope stratigraphy, several discrete ages within the 590-544 Myr interval, and two age-groups at 660-610 and 740-690 Myr can be resolved

    THE APPLICATION OF THE VIRTUAL REALITY FOR TRAINING OPERATORS OF MOBILE OBJECTS

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    In this paper the formulation of the problem and the results of pilot study in the field of application of the virtual reality for training operators of mobile objects are proposed. The main goal of the research is to assess the “sensitivity” of the operator’s skills and algorithms of their development to the acceleration that are inevitable in mobile controlled objects. This approach allows creating individual trajectories of operator training, in which the combination of training in a physical system and virtual reality is rationally justifiedОбозначены задачи и представлены результаты экспериментальных исследований в области применения систем виртуальной реальности для обучения операторов подвижных объектов управления. Основной целью проведенных исследований была оценка «чувствительности» профессиональных навыков оператора и алгоритмов их развития при перегрузках, которые неизбежны в подвижных объектах. Сделан вывод в том, что такой подход позволяет создавать индивидуальные траектории обучения оператора, в которых рационально обосновано сочетание обучения в физической системе и виртуальной реальности
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