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981.
The simple \(GL(n,\mathbb {C})\)-modules are described by using semistandard Young tableaux. Any semistandard skew tableau can be transformed into a well defined semistandard tableau by a combinatorial operation, the Schützenberger jeu de taquin. Associated to the classical Lie groups \(SP(2n,\mathbb {C})\), \(SO(2n+1,\mathbb {C})\), there are other notions of semistandard Young tableaux and jeux de taquin. In this paper, we study these various jeux de taquin, proving that each of them has a simple and explicit formulation as a step-by-step sliding. Any of these jeux de taquin is the restriction of the orthogonal one, associated to \(SO(2n+1,\mathbb {C})\).  相似文献   
982.
The class of vehicle routing problems involves the optimization of freight or passenger transportation activities. These problems are generally treated via the representation of the road network as a weighted complete graph. Each arc of the graph represents the shortest route for a possible origin–destination connection. Several attributes can be defined for one arc (travel time, travel cost, etc.), but the shortest route modeled by this arc is computed according to a single criterion, generally travel time. Consequently, some alternative routes proposing a different compromise between the attributes of the arcs are discarded from the solution space. We propose to consider these alternative routes and to evaluate their impact on solution algorithms and solution values through a multigraph representation of the road network. We point out the difficulties brought by this representation for general vehicle routing problems, which drives us to introduce the so-called fixed sequence arc selection problem (FSASP). We propose a dynamic programming solution method for this problem. In the context of an on-demand transportation (ODT) problem, we then propose a simple insertion algorithm based on iterative FSASP solving and a branch-and-price exact method. Computational experiments on modified instances from the literature and on realistic data issued from an ODT system in the French Doubs Central area underline the cost savings brought by the proposed methods using the multigraph model.  相似文献   
983.
This paper reports the results of the thermal stability study of M–YSZ (M=Ni, Cu, Co, Cu–Co, Ni–Cu–Co) SOFC anode cermets materials at different heat treatment temperatures. The cermets were elaborated by atmospheric plasma spraying (APS) with optimized conditions and then submitted to heat treatments at 800 and 1000 °C, respectively. Scanning electron microscopy and X-ray diffraction were used to characterize, respectively, the morphology and structure of obtained films, before and after thermal annealing. A correlation was made between the differential scanning calorimetry analysis results and those obtained by X-ray diffraction. Focusing, in this study, on YSZ matrix thermal stability, the obtained results were as follows: the monometallic cermets with the lowest amount of metal and the trimetallic one exhibited a good stability at 800 °C, whereas at 1000 °C, all considered cermets were unstable with a eutectoid decomposition of YSZ matrix.  相似文献   
984.
In this article we are interested in the numerical computation of spectra of non-self adjoint quadratic operators. This leads to solve nonlinear eigenvalue problems. We begin with a review of theoretical results for the spectra of quadratic operators, especially for the Schrödinger pencils. Then we present the numerical methods developed to compute the spectra: spectral methods and finite difference discretization, in infinite or in bounded domains. The numerical results obtained are analyzed and compared with the theoretical results. The main difficulty here is that we have to compute eigenvalues of strongly non-self-adjoint operators which are very unstable.  相似文献   
985.
We consider a Navier–Stokes type system with a Korteweg stress tensor, coupled with a concentration equation without diffusion. We give a result concerning the local in time existence (and uniqueness) of strong solution for any data (and the global in time existence defined in a interval (0,T) for T<+ fixed if data are small enough), in the case of a bounded domain Ω?R3. To cite this article: M. Sy et al., C. R. Acad. Sci. Paris, Ser. I 342 (2006).  相似文献   
986.
The homogenization of periodic dielectric structures in harmonic regime usually leads to an effective permittivity tensor ?eff. It has been observed by Bouchitté and Felbacq [Waves Random Media 7 (1997) 245–256], that in the high contrast case (high conductivity fibers), this tensor depends on the angular frequency ω. In this Note, we enlight a new effect induced by microscopic resonances which leads in parallel to a possibly negative effective permeability μeff(ω) (although the original medium is assumed to be nonmagnetic i.e. μ=1). To cite this article: G. Bouchitté, D. Felbacq, C. R. Acad. Sci. Paris, Ser. I 339 (2004).  相似文献   
987.
The aim of this paper was to determine whether fractal processes underlie the dynamics of self-esteem and physical self. Twice a day for 512 consecutive days, four adults completed a brief inventory measuring six subjective dimensions: global self-esteem, physical self-worth, physical condition, sport competence, attractive body, and physical strength. The obtained series were submitted to spectral analysis, which allowed their classification as fractional Brownian motions. Three fractal analysis methods (Rescaled Range analysis, Dispersional analysis, and Scaled Windowed Variance analysis) were then applied on the series. These analyses yielded convergent results and evidenced long-range correlation in the series. The self-esteem and physical self series appeared as anti-persistent fractional Brownian motions, with a mean Hurst exponent of 0.21. These results reinforce the conception of self-perception as the emergent product of a dynamical system composed of multiple interacting elements.  相似文献   
988.
Vortex streets formed behind oscillating bluff bodies consist of arrays of groups of two, three, or four vortices classified as 2S, P+S, and 2P shedding modes, respectively. The prevailing dominant mode depends primarily on the amplitude and the frequency of the oscillation and on the Reynolds number. We investigate the effect of noise at the inflow on the stability of these vortex modes in laminar flow past a circular cylinder. We employ stochastic simulations based on a new polynomial chaos method to study the shedding-mode switching from a P+S pattern to a 2S mode in the presence of noise.  相似文献   
989.
It is common knowledge that in an infinite periodic medium, for instance, an infinite photonic crystal, the direction of propagation of a monochromatic wave packet is given by the normal to the isofrequency diagram. We show that this is no longer true in a finite size medium, due to the existence of evanescent waves near the interfaces of the photonic crystal. We derive a renormalized isofrequency diagram giving the correct direction. We give a physical interpretation, showing that this phenomenon can be considered as a generalized Goos-H?nchen effect.  相似文献   
990.
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