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991.
In this paper we continue to study properties of the value function and of optimal solutions of a semilinear Mayer problem in infinite dimensions. Applications concern systems governed by a state equation of parabolic type. In particular, the issues of the joint Lipschitz continuity and semiconcavity of the value function are treated in order to investigate the differentiability of the value function along optimal trajectories.The research of P. Cannarsa was partially supported by the Italian National Project MURST Equazioni di Evoluzione e Applicazioni Fisico-Matematiche. 相似文献
992.
993.
It is shown that for a large class of Lie groups (called weakly algebraic groups) including all connected semisimple Lie groups the following holds: for any probability measure on the Lie group the set of all two-sided convolution factors is compact if and only if the centralizer of the support of inG is compact. This is applied to prove that for any connected Lie groupG, any homomorphism of any real directed (submonogeneous) semigroup into the topological semigroup of all probability measures onG is locally tight. 相似文献
994.
We consider a representation of the entropy production for a completely positive, trace-preserving dynamical semigroup satisfying detailed balance with respect to its faithful stationary state denned on aW*-algebra(): it is expressed as a positive Hermitian form on(), which is analogous to the quantum correlation functions used in the Kubo theory. By considering this Hermitian form as a variation function of a vector in(), an exact characterization of the stationary states of semigroups in a certain class is obtained. On this basis, the problem of characterizing the stationary states discussed by Spohn and Lebowitz for manyreservoir open systems is solved without the restriction to situations near thermal equilibrium. 相似文献
995.
Generalized result with a unified proof of global existence to a class of reaction‐diffusion systems 下载免费PDF全文
We prove in this paper a generalized result with a unified proof of global existence in time of classical solutions to a class of a reaction diffusion system with triangular diffusion matrix on a bounded domain in . The system in question is ut=aΔu ? f(x,t,u,v), vt=cΔu + dΔv + ρf(x,t,u,v), , t > 0 with f(x,t,0,η) = 0 and f(x,t,ξ,η)≤Kφ(ξ)eση, for all x∈Ω, t > 0, ξ≥0, η≥0; where ρ, K and σ are real positive constants. Copyright © 2016 John Wiley & Sons, Ltd. 相似文献
996.
Xian Hua Tang 《数学学报(英文版)》2016,32(4):463-473
We consider the nonlinear difference equations of the form
Lu=f(n, u), n∈Z,
where L is a Jacobi operator given by(Lu)(n)=a(n)u(n+1)+a(n-1)u(n-1)+b(n)u(n) for n∈Z, {a(n)} and {b(n)} are real valued N-periodic sequences, and f(n, t) is superlinear on t. Inspired by previous work of Pankov [Discrete Contin. Dyn. Syst., 19, 419-430(2007)] and Szulkin and Weth [J. Funct. Anal., 257, 3802-3822(2009)], we develop a non-Nehari manifold method to find ground state solutions of Nehari-Pankov type under weaker conditions on f. Unlike the Nehari manifold method, the main idea of our approach lies on finding a minimizing Cerami sequence for the energy functional outside the Nehari-Pankov manifold by using the diagonal method. 相似文献
997.
998.
为了解决当前图像伪造检测算法主要是在图像空域中定位伪造区域,难以降低图像维数,使其复杂度大;且不能有效检测几何变换篡改形式的伪造区域,导致其鲁棒性不佳的不足,本文提出了离散小波变换耦合静电场理论的图像伪造检测算法。首先,引入离散小波变换,提取伪造图像的低频子带,降低图像空间;再基于静电场理论,将提取子带映射到虚拟电场中,提取鲁棒性较强的特征,利用Radix排序算法对特征完成重组,形成特征矩阵;最后,定义相同仿射变换,并用其处理排序矩阵,完成伪造区域检测。实验测试结果显示:与当前的移动复制伪造检测技术相比,本文算法具有更高的定位效率与检测精度;同时拥有较强的鲁棒性,有效抗击几何变换篡改。 相似文献
999.
1000.