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991.
992.
Summary. The integrated autocovariance and autocorrelation time are essential tools to understand the dynamical behavior of a Markov
chain. We study here these two objects for Markov chains with rare transitions with no reversibility assumption. We give upper
bounds for the autocovariance and the integrated autocorrelation time, as well as exponential equivalents at low temperature.
We also link their slowest modes with the underline energy landscape under mild assumptions. Our proofs will be based on large
deviation estimates coming from the theory of Wentzell and Freidlin and others [4, 3, 12], and on coupling arguments (see
[6] for a review on the coupling method).
Received 5 August 1996 / In revised form: 6 August 1997 相似文献
993.
Variable space search for graph coloring 总被引:1,自引:0,他引:1
Alain Hertz Matthieu Plumettaz Nicolas Zufferey 《Discrete Applied Mathematics》2008,156(13):2551-2560
Let G=(V,E) be a graph with vertex set V and edge set E. The k-coloring problem is to assign a color (a number chosen in {1,…,k}) to each vertex of G so that no edge has both endpoints with the same color. We propose a new local search methodology, called Variable Space Search, which we apply to the k-coloring problem. The main idea is to consider several search spaces, with various neighborhoods and objective functions, and to move from one to another when the search is blocked at a local optimum in a given search space. The k-coloring problem is thus solved by combining different formulations of the problem which are not equivalent, in the sense that some constraints are possibly relaxed in one search space and always satisfied in another. We show that the proposed algorithm improves on every local search used independently (i.e., with a unique search space), and is competitive with the currently best coloring methods, which are complex hybrid evolutionary algorithms. 相似文献
994.
Nonlinear amplitude equations for the near-threshold behavior of twisted extensible elastic rods under tension with inertial
and dissipative dynamics are derived. In the inertial case localized solutions to the amplitude equations are derived and
a linear stability criterion for the pulse solutions is obtained using the Hamiltonian formulation of the problem. 相似文献
995.
Alain Quilliot 《Discrete Applied Mathematics》2008,156(17):3267-3275
We present a theoretical framework, which is based upon notions of ordered hypergraphs and antichain polyhedra, and which is dedicated to the combinatorial analysis of preemptive scheduling problems submitted to parallelization constraints.This framework allows us to characterize specific partially ordered structures which are such that induced preemptive scheduling problems may be solved through linear programming. To prove that, in the general case, optimal preemptive schedules may be searched inside some connected subset of the vertex set of an Antichain Polyhedron. 相似文献
996.
The aim of this paper is to present a procedure of construction of constitutive equations within the framework of Continuum
Mechanics. The main focus of our effort is to introduce the geometric change at a high level of strain and the damage which
are generally developed in simple tests (tension, shear) of polymeric materials such as polypropylene compounds or copolymers
(PP). High-resolution strain-mapping techniques are employed to determine the surface strain fields and, consequently, a measurement
of the volume change. A phenomenological model based upon experimental observations was developed to reproduce the main behavior,
e.g., the stress strain curves, including the volume change and their consequences. State Variables are defined and related
to their evolution in relation with the state laws. The identification of the resulting model was made by reproducing the
data issued from basic tests (Tension, Iosipescu Shear).
Published in Russian in Vysokomolekulyarnye Soedineniya, Ser. A. 2008, Vol. 50, No. 5, pp. 850–861.
This article was submitted by the authors in English. 相似文献
997.
Masamichi Tsuboi Yoshiaki Hamada Lucien Henry Jean Chazelas Alain Valentin 《Journal of Molecular Spectroscopy》1984,108(2):328-342
The infrared absorption spectrum of NH2NH2 vapor has been observed in the region 899–1077 cm?1, where the antisymmetric wagging band (va = 1 ← 0) appears, by the use of a Fourier transform spectrometer with a practical resolution of 0.003 cm?1. In the region 925.0–925.6 cm?1, the spectrum was also observed with a tunable diode laser, and a component, β, of the pQ2 cluster has been further resolved. Most of the absorption lines assignable to β-pP2(J″), γ-pP2(J″), β-pQ2(J″), γ-rQ0(J″), β-rR0(J″), and γ-rR0(J″), where J″ = 2 ~ 15, have been identified. From these observed transition frequencies, in combination with the ground state energy levels given by microwave spectroscopy, the energy level structure of the K′ = 1 rotational states was determined. From this, the following molecular parameters for the va = 1 state were determined: molecular asymmetry, B′-C″ = 0.00017 cm?1; a parameter q5 describing an umbrella motion Coriolis interaction (q5K) about the a axis, q5 = ?0.0030 cm?1; its J(J + 1) variation, q5j = 0.00014 cm?1; and a parameter describing an umbrella-motion K-type doubling g5J(J + 1), g5 = 0.000021 cm?1. 相似文献
998.
Alain Deronzier 《Tetrahedron letters》1984,25(27):2867-2868
The reduction of tropylium cation (Tr+) with the concomitant oxidation of O,O′-dialkyldithiophosphate anions (dtp?) have been achieved by visible irradiation of their acetonitrile solution in presence of a bipyridinium dication ; the later via its charge transfer complex with dtp? acts as a light-harvest and as an electron relay. 相似文献
999.
1000.
A stochastic variational inequality is proposed to model a white noise excited elasto-plastic oscillator. The solution of
this inequality is essentially a continuous diffusion process for which a governing diffusion equation is obtained to study
the evolution in time of its probability distribution. The diffusion equation is degenerate, but using the fact that the degeneracy
occurs on a bounded region we are able to show the existence of a unique solution satisfying the desired properties. We prove
the ergodic properties of the process and characterize the invariant measure. Our approach relies on extending Khasminskii’s
method (Stochastic Stability of Differential Equations, Sijthoff and Noordhoff, 1980), which in the present context leads to the study of degenerate Dirichlet problems with nonlocal boundary conditions.
This research was partially supported by a grant from CEA, Commissariat à l’énergie atomique and by the National Science Foundation
under grant DMS-0705247. 相似文献