共查询到20条相似文献,搜索用时 171 毫秒
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Sans résumé
Les A. ont été soutenus par l’Interpol. 相似文献
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本文给出了空间L ̄a,2(D×D,)的一个完全正交分解,定义了一系列Toeplitz型与Hankel型算子,并且证明了它们的有界性,紧性及其Schatten-vonNeumann性质. 相似文献
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广义D运输问题 总被引:1,自引:1,他引:0
白国仲 《数学的实践与认识》2009,39(23)
D运输问题是一类要求将货物在某一个时间以前如数运抵目的地的运输问题,比如节日物资的运输问题.基于物流管理的需要,提出了广义D运输问题.广义D运输问题是各个销地对货物的运抵时间有不同要求,即各个销地对于货物的需求时间不一定相同的一般情况.建立了广义D运输问题的数学模型,引入了可实施解、满意解、最优解等概念,给出了求解方法和一个计算例子. 相似文献
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Tatsuo Nishitani 《Annali dell'Universita di Ferrara》2006,52(2):395-430
Abstract The well posedness of the Cauchy problem for the operator P=Dt2–Dxa(t,x)nDx,
with data on t=0 is studied assuming a ∈ CN(
(R)), s0>1 and sufficiently close to 1, a(t,x)≥ 0. Well posedness is proved in Gevrey classes γ(s), for
, n≥ n0.
Keywords: Partial differential equations, Cauchy problem, Well posedness 相似文献
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3D打印技术的兴起在许多领域掀起了新的研究热点,《3D打印中的优化设计》应用课题针对几何处理领域中的许多相关问题做了系统性的研究,其中包括在3D打印中通过几何模型的结构优化以节省打印材料和打印时间的问题,三维几何模型保持特征的去噪和构建问题,以及三维几何模型的序贯重建和多余分支去除问题.相关问题中多涉及含有复杂约束的优化问题,以及压缩感知和稀疏优化问题.本文简要总结了上述问题的研究方法,并从几何优化的角度阐述了其中运筹学原理与方法的运用,表明了运筹学工具在相关领域研究中的重要性和有效性. 相似文献
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In this paper, we extend the lattice Constructions D, \(D'\) and \(\overline{D}\) (this latter is also known as Forney’s code formula) from codes over \(\mathbb {F}_p\) to linear codes over \(\mathbb {Z}_q\), where \(q \in \mathbb {N}\). We define an operation in \(\mathbb {Z}_q^n\) called zero-one addition, which coincides with the Schur product when restricted to \(\mathbb {Z}_2^n\) and show that the extended Construction \(\overline{D}\) produces a lattice if and only if the nested codes are closed under this addition. A generalization to the real case of the recently developed Construction \(A'\) is also derived and we show that this construction produces a lattice if and only if the corresponding code over \(\mathbb {Z}_q[X]/X^a\) is closed under a shifted zero-one addition. One of the motivations for this work is the recent use of q-ary lattices in cryptography. 相似文献
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We consider a nonlinear Schrödinger equation with power nonlinearity, either on a compact manifold without boundary, or on the whole space in the presence of harmonic confinement, in space dimension one and two. Up to introducing an extra superlinear damping to prevent finite time blow up, we show that the presence of a sublinear damping always leads to finite time extinction of the solution in 1D, and that the same phenomenon is present in the case of small mass initial data in 2D. 相似文献
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