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441.
The combined effects of vertical heterogeneity of permeability and local thermal non-equilibrium (LTNE) on the onset of ferromagnetic convection in a ferrofluid saturated Darcy porous medium in the presence of a uniform vertical magnetic field are investigated. A two-field model for temperature representing the solid and fluid phases separately is used. The eigenvalue problem is solved numerically using the Galerkin method for different forms of permeability heterogeneity function Γ(z) and their effect on the stability characteristics of the system has been analyzed in detail. It is observed that the general quadratic variation of Γ(z) with depth has more destabilizing effect on the system when compared to the homogeneous porous medium case. Besides, the influence of LTNE and magnetic parameters on the criterion for the onset of ferromagnetic convection is also assessed. 相似文献
442.
Four compounds in the system (Li, Na)VO3 were synthesized and their structures refined in the space group . Site population analysis showed that their compositions are (Na0.5Li0.5)VO3, (Na0.62Li0.38)VO3, (Na0.71Li0.29)VO3 and (Na0.84Li0.16)VO3. All have the structure of LiVO3 and α-NaVO3 which are related to the silicate pyroxenes. Structural data of eight compounds in the system (K, Na, Li)VO3 were compiled, and correlations were established by multiple regression analyses between the effective ionic radii rM1 and rM2 of the alkali metal ions and various structural parameters. The size of the M2 site and the relative displacement of the (VO3)∞ chains are found to depend primarily on rM2 only. The size of the M1 site and the amount of chain rotation are affected by both rM1 and rM2. Changes in lattice parameters are related to the chain movements. The anomalous chain configuration of LiVO3 is also discussed. 相似文献
443.
Robust Principal Component Analysis plays a key role in various fields such as image and video processing, data mining, and hyperspectral data analysis. In this paper, we study the problem of robust tensor train (TT) principal component analysis from partial observations, which aims to decompose a given tensor into the low TT rank and sparse components. The decomposition of the proposed model is used to find the hidden factors and help alleviate the curse of dimensionality via a set of connected low-rank tensors. A relaxation model is to minimize a weighted combination of the sum of nuclear norms of unfolding matrices of core tensors and the tensor norm. A proximal alternating direction method of multipliers is developed to solve the resulting model. Furthermore, we show that any cluster point of the convergent subsequence is a Karush-Kuhn-Tucker point of the proposed model under some conditions. Extensive numerical examples on both synthetic data and real-world datasets are presented to demonstrate the effectiveness of the proposed approach. 相似文献
444.
On Cauchy differences of all orders 总被引:1,自引:0,他引:1
Summary This paper deals with the problem of characterizing higher order Cauchy differences of mappings on groups and semigroups. Symmetric, first order Cauchy differencesf(x + y)–f(x)–f(y) for mapsf between groups were characterized by Jessen, Karpf, and Thorup [8] through the use of first partial Cauchy differences. Our results are similar and extend their result to higher order differences. Our results also extend those of Heuvers [6] for mappings between vector spaces over the rationals. 相似文献
445.
446.
Error Bounds of Constrained Quadratic Functions and Piecewise Affine Inequality Systems 总被引:1,自引:0,他引:1
We consider the error bounds for a piecewise affine inequality system and present a necessary and sufficient condition for this system to have an error bound, which generalizes the Hoffman result. Moreover, we study the error bounds of the system determined by a quadratic function and an abstract constraint. 相似文献
447.
Che Tat Ng 《Results in Mathematics》2003,44(3-4):340-361
The functional equation ?(h(x)) ? ?(h(y)) + ?(y) = ?(h(x ? y) + y) was solved by Aczél, Luce and Marley on the assumption that the functions are different iable. They posed the question of its strictly monotonic continuous solutions. The problem is solved using a uniqueness theorem. The continuity assumption on the functions is removed and the equation is also solved on a restricted domain. 相似文献
448.
449.
D. Dalili P. Lhenoret R. Lucas C. Mazur C. Ngô M. Ribrag T. Suomijarvi E. Tomasi B. Boishu A. Genoux Lubin C. Lebrun J. F. Lecolley F. Lefebvres M. Louvel R. Regimbart J. C. Adloff A. Kamili G. Rudolf F. Scheibling 《Zeitschrift für Physik A Hadrons and Nuclei》1984,318(3):371-372
The Qβ-values of99Rb,99,100Sr and100Y have been measured for the first time at the mass separator OSTIS of the ILL; for99Y,99,100Zr and100Nb, the results of earlier experiments were confirmed with reduced experimental errors. The two-neutron binding energies derived from the experimental Qβ-values clearly indicate that the nuclei100Sr and100Y are strongly deformed. 相似文献
450.
We study the Clarke–Rockafellar directional derivatives of the regularized gap functions (and of some modified ones) for the
variational inequality problem (VIP) defined by a locally Lipschitz but not necessarily differentiable function on a closed
convex set in an Euclidean space. As applications we show that, under the strong monotonicity assumption, the regularized
gap functions have fractional exponent error bounds and consequently that the sequences provided by an algorithm of Armijo
type converge to the solution of the (VIP).
The research of this author was supported by an Earmarked Grant from the Research Council of Hong Kong. 相似文献