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一类广义Bent型S-Box的构造 总被引:1,自引:0,他引:1
王章雄 《数学的实践与认识》2002,32(6):999-1002
S-box是密码理论与实践中十分重要的一种装置 ,它的密码性能由其分量函数所决定 .于是 ,选择适当的分量函数来构造 S-box就成了一个重要的研究课题 .在一定意义上 ,Bent函数是最优良的密码函数 .本文通过函数序列半群和置换群来构造其任何非零线性组合为 Bent函数与线性函数之和的函数组 ,从而可由 Bent函数构造出具有高度非线性度和其他良好性状的 S-box 相似文献
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Jeroen Suijs Peter Borm Herbert Hamers Marieke Quant Maurice Koster 《Annals of Operations Research》2005,137(1):117-140
This paper focuses on sharing the costs and revenues of maintaining a public network communication structure. Revenues are
assumed to be bilateral and communication links are publicly available but costly. It is assumed that agents are located at
the vertices of an undirected graph in which the edges represent all possible communication links. We take the approach from
cooperative game theory and focus on the corresponding network game in coalitional form which relates any coalition of agents
to its highest possible net benefit, i.e., the net benefit corresponding to an optimal operative network. Although finding
an optimal network in general is a difficult problem, it is shown that corresponding network games are (totally) balanced.
In the proof of this result a specific relaxation, duality and techniques of linear production games with committee control
play a role. Sufficient conditions for convexity of network games are derived. Possible extensions of the model and its results
are discussed.
The research of Jeroen Suijs has been made possible by a fellowship of the Royal Netherlands Academy of Arts and Sciences. 相似文献
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We provide simple constructive proofs of balancedness of classes of m-PS (m-Parallel Sequencing) games, which arise from sequencing situations with m parallel machines. This includes the setting that is studied by Calleja et al. (2001) and Calleja et al. (2002), who provided a complex constructive proof and a simple non-constructive proof of balancedness of a restricted class
of 2-PS games, respectively. Furthermore, we provide a counterexample to illustrate that our balancedness results cannot be
extended to a general setting. 相似文献
5.
The seminal contribution of Debreu and Scarf (Int Econ Rev 4:235–246, 1963) connects the two concepts of core and competitive
equilibrium in exchange economies. In effect, their core-equilibrium equivalence result states that, when the set of economic
agents is replicated, the set of core allocations of the replica economy shrinks to the set of competitive allocations. Florenzano
(J Math Anal Appl 153:18–36, 1990) defines the fuzzy core as the set of allocations which cannot be blocked by any coalition
with an arbitrary rate of participation and then shows the asymptotic limit of cores of replica economies coincides with the
fuzzy core. In this note, we provide an elementary proof of the non-emptiness of the fuzzy core for an exchange economy. Hence,
in motivation, our result is similar to the contribution of Vohra (On Scarf’s theorem on the non-emptiness of the core: a
direct proof through Kakutani’s fixed point theorem. Brown University Working Paper, 1987) and Shapley and Vohra (Econ Theory
1:108–116, 1991) for the core. Unlike the classical Debreu–Scarf limit theorem (Debreu and Scarf in Int Econ Rev 4:235–246,
1963) and its numerous extensions our result does not require any asymptotic intersection—or limit—of the set of core allocations
of replica economies.
The author would like to thank the Netherlands Organisation for Scientific Research (NWO) for financial support. 相似文献
6.
On unconditionally positive implicit time integration for the DG scheme applied to shallow water flows 下载免费PDF全文
We present a new unconditionally positivity‐preserving (PP) implicit time integration method for the DG scheme applied to shallow water flows. This novel time discretization enhances the currently used PP DG schemes, because in the majority of previous work, explicit time stepping is implemented to deal with wetting and drying. However, for explicit time integration, linear stability requires very small time steps. Especially for locally refined grids, the stiff system resulting from space discretization makes implicit or partially implicit time stepping absolutely necessary. As implicit schemes require a lot of computational time solving large systems of nonlinear equations, a much larger time step is necessary to beat explicit time stepping in terms of CPU time. Unfortunately, the current PP implicit schemes are subject to time step restrictions due to a so‐called strong stability preserving constraint. In this work, we hence give a novel approach to positivity preservation including its theoretical background. The new technique is based on the so‐called Patankar trick and guarantees non‐negativity of the water height for any time step size while still preserving conservativity. In the DG context, we prove consistency of the discretization as well as a truncation error of the third order away from the wet–dry transition. Because of the proposed modification, the implicit scheme can take full advantage of larger time steps and is able to beat explicit time stepping in terms of CPU time. The performance and accuracy of this new method are studied for several classical test cases. Copyright © 2014 John Wiley & Sons, Ltd. 相似文献
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Pedro Calleja Peter Borm Herbert Hamers Flip Klijn Marco Slikker 《Annals of Operations Research》2002,109(1-4):265-277
This paper considers a special class of sequencing situations with two parallel machines in which each agent has precisely two jobs to be processed, one on each machine. The costs of an agent depend linearly on the final completion time of his jobs. We describe a procedure that provides an optimal processing order of the jobs for some particular classes. Furthermore, we study cooperative games arising from these sequencing situations. Our main result will be on the balancedness of these games. 相似文献
10.
Herings P. J. J. Talman A. J. J. 《Journal of Optimization Theory and Applications》1998,96(2):311-335
In all existing intersection theorems, conditions are given under which a certain subset of a collection of sets has a nonempty intersection. In this paper, conditions are formulated under which the intersection is a continuum of points satisfying some interesting topological properties. In this sense, the intersection theorems considered in this paper belong to a new class. The intersection theorems are formulated on the unit cube and it is shown that both the vector of zeroes and the vector of ones lie in the same component of the intersection. An interesting application concerns the model of an economy with price rigidities. Using the intersection theorems of this paper, it is easily shown that there exists a continuum of zero points in such a model. The intersection theorems treated give a generalization of the well-known lemmas of Knaster, Kuratowski, and Mazurkiewicz (Ref. 1), Scarf (Ref. 2), Shapley (Ref. 3), and Ichiishi (Ref. 4). Moreover, the results can be used to sharpen the usual formulation of the Scarf lemma on the cube. 相似文献