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901.
Zdzisław Brzeźniak Utpal Manna Akash Ashirbad Panda 《Journal of Differential Equations》2019,266(10):6204-6283
In this work we consider a stochastic evolution equation which describes the system governing the nematic liquid crystals driven by a pure jump noise in the Marcus canonical form. The existence of a martingale solution is proved for both 2D and 3D cases. The construction of the solution relies on a modified Faedo–Galerkin method based on the Littlewood–Paley-decomposition, compactness method and the Jakubowski version of the Skorokhod representation theorem for non-metric spaces. We prove that in the 2-D case the martingale solution is pathwise unique and hence deduce the existence of a strong solution. 相似文献
902.
Hans-E. Porst 《Applied Categorical Structures》2004,12(4):355-360
Subdirect representations are investigated in varieties which are defined by operations of not necessarily finite arity. It is shown that, in this context, Birkhoff's Subdirect Representation Theorem does not hold. However, a class of unranked varieties is identified which admit subdirect representations by subdirectly irreducibles and are even residually small. 相似文献
903.
This paper presents an extensive bibliography of the archival material on model management, and an analysis of that material. It argues that the three general approaches to model management can be observed, called here the data-model analogy, knowledge-based and model-representation approaches. For the period 1970 to 1989, 57 journals were exhaustively searched for articles dealing with model management; 152 articles were identified. An informal analysis shows that model creation and execution have been the major model management functions addressed by research, and that mathematical programming and simulation have been the dominant model areas. Applications have addressed the extremes of Operations Research models, namely policy and strategy at one extreme and operations at the other, with many applications in accounting and finance also prevalent. A formal analysis using factor analysis shows that research in model management has moved away from speculation and focus on certain limited aspects of the subject towards the practical implementation of model management systems. Further, a regression model shows that the model-representation approach has tended to yield implemented systems, whereas the data-model analogy approach has not. Directions for future research and development are suggested. 相似文献
904.
We use a generalization of Wiener's 1/f theorem to prove that for a Gabor frame with the generator in the Wiener amalgam space W(L∞,?1)(Rd), the corresponding frame operator is invertible on this space. Therefore, for such a Gabor frame, the canonical dual belongs also to W(L∞,?1)(Rd). 相似文献
905.
We give a new construction of the rational Urysohn space UQ, which yields a finite presentation of UQ. This may be viewed as an extension of the finite presentation of the generic partial order. 相似文献
906.
Tangent cone and (regular) normal cone of a closed set under an invertible variable transformation around a given point are investigated, which lead to the concepts of θ−1-tangent cone of a set and θ−1-subderivative of a function. When the notion of θ−1-subderivative is applied to perturbation functions, a class of augmented Lagrangians involving an invertible mapping of perturbation variables are obtained, in which dualizing parameterization and augmenting functions are not necessarily convex in perturbation variables. A necessary and sufficient condition for the exact penalty representation under the proposed augmented Lagrangian scheme is obtained. For an augmenting function with an Euclidean norm, a sufficient condition (resp., a sufficient and necessary condition) for an arbitrary vector (resp., 0) to support an exact penalty representation is given in terms of θ−1-subderivatives. An example of the variable transformation applied to constrained optimization problems is given, which yields several exact penalization results in the literature. 相似文献
907.
In this paper we give a survey about the Roper-Suffridge extension operator and the developments in the theory of univalent
mappings in several variables to which it has led. We begin with the basic geometric properties (most of which now have a
number of different proofs) and discuss relations with the theory of Loewner chains and generalizations and modifications
of the operator, some of which are very recent.
Dedicated to Professor Sheng GONG on the occasion of his 75th birthday 相似文献
908.
Wojciech Chojnacki 《Proceedings of the American Mathematical Society》1998,126(2):491-497
We show that a theorem of Kisynski on the generation of Banach-algebra homomorphisms of certain convolution algebras is equivalent to the Hille-Yosida theorem on the generation of operator-valued one-parameter semigroups.
909.
G. G. Amanzhaev 《Mathematical Notes》1998,64(5):557-561
For discrete analogs of classes of functions of finite smoothness, we study the quantity log Approx characterizing the minimal
necessary length of tables that allow us to reconstruct functions from these classes with error not exceeding 1 in the metric
of the spaceL
p
.
Translated fromMatematicheskie Zametki, Vol. 64, No. 5, pp. 643–647, November, 1998.
The author wishes to express his gratitude to his scientific adviser O. B. Lupanov for setting the problem and attention to
the author's work.
This research was supported by the Russian Foundation for Basic Research under grant No. 96-01-01068. 相似文献
910.
关于G-分次环与G-集的Smash积的几个结果 总被引:1,自引:0,他引:1
设G为任意群,本文借助于环的矩阵表示给出了G-分次环与任意可迁G-集的Smash积是素环或单环的刻画。 相似文献