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71.
We establish an example of a functorial lift from generic cuspidal representations of a similitude group of the type A 1×C 2 to generic representations of Spin7. Our construction uses the theta correspondence associated to the dual pair of the type (A 1×C 2 B 3) inside E 7. We also consider another theta correspondence associated to the dual pair of type (A 1×C 2 A 1×A 1) in D 6 and show that these two pairs fit into a tower and the standard properties of a tower of theta correspondences hold.  相似文献   
72.
Our paper studies the topology of uniform convergence on compact sets on the space of densely continuous forms (introduced by Hammer and McCoy (1997)), usco and minimal usco maps. We generalize and complete results from Hammer and McCoy (1997) concerning the space D(X,Y) of densely continuous forms from X to Y. Let X be a Hausdorff topological space, (Y,d) be a metric space and D k (X,Y) the topology of uniform convergence on compact sets on D(X,Y). We prove the following main results: D k (X,Y) is metrizable iff D k (X,Y) is first countable iff X is hemicompact. This result gives also a positive answer to question 4.1 of McCoy (1998). If moreover X is a locally compact hemicompact space and (Y,d) is a locally compact complete metric space, then D k (X,Y) is completely metrizable, thus improving a result from McCoy (1998). We study also the question, suggested by Hammer and McCoy (1998), when two compatible metrics on Y generate the same topologies of uniform convergence on compact sets on D(X,Y). The completeness of the topology of uniform convergence on compact sets on the space of set-valued maps with closed graphs, usco and minimal usco maps is also discussed.  相似文献   
73.
We construct a new family of cyclic difference sets with parameters ((3 d – 1)/2, (3 d – 1 – 1)/2, (3 d – 2 – 1)/2) for each odd d. The difference sets are constructed with certain maps that form Jacobi sums. These new difference sets are similar to Maschietti's hyperoval difference sets, of the Segre type, in characteristic two. We conclude by calculating the 3-ranks of the new difference sets.  相似文献   
74.
对覆盖广义Rough集中的隶属关系、隶属函数进行了定义,并利用隶属函数定义了集合的Rough包含与Rough相等,得到一些与Pawlak的Rough集不同的性质。  相似文献   
75.
在标准Rough集理论的指导下,利用偏序关系性质构造了不同分类,并以此为基础探讨了上、下近似集,从而构建了基于偏序关系的Rough集模型。新模型将Rough集理论的应用范围由等价关系扩展到偏序关系。为了更好地增强模型的实用性和灵括性,一方面从程度、精度、概率等角度出发分别对其进行了扩展,另一方面引入依赖度使其适用于研究各种非严格的偏序关系。给出了实例分析,并结合现实生活中的现象阐述了模型的应用价值。  相似文献   
76.
马海成  扈生彪 《数学季刊》2003,18(2):163-167
In this paper,we show that there exist precisely W(A) Ferrers matrices F(C1,C2,…,cm)such that the rook polynomials is equal to the rook polynomial of Ferrers matrix F(b1,b2,…,bm), where A={b1,b2-1,…,bm-m 1} is a repeated set,W(A) is weight of A.  相似文献   
77.
The structure of any a.s. self-similar set K(w) generated by a class of random elements {gn,wσ} taking values in the space of contractive operators is given and the approximation of K(w) by the fixed points {Pn,wσ} of {gn,ow} is obtained. It is useful to generate the fractal in computer.  相似文献   
78.
无界区域R1上推广的B-BBM方程的整体吸引子   总被引:4,自引:0,他引:4  
本文研究了无界区域R^1上推广的B—BBM方程的长时间动力学行为,证明了该方程整体吸引子的存在性.  相似文献   
79.
Banach空间中二阶积分-微分方程的初值问题   总被引:5,自引:0,他引:5  
使用锥理论及单调迭代技术,首先讨论了Banach空间中一阶积分-微分方程初值问题的最小最大解的存在性,并在此基础上讨论了带有一阶微分项的二阶积分-微分方程初值问题的最小最大解的存在性。  相似文献   
80.
A result of Balas and Yu (1989) states that the number of maximal independent sets of a graph G is at most p+1, where is the number of pairs of vertices in G at distance 2, and p is the cardinality of a maximum induced matching in G. In this paper, we give an analogue of this result for hypergraphs and, more generally, for subsets of vectors in the product of n lattices =1××n, where the notion of an induced matching in G is replaced by a certain binary tree each internal node of which is mapped into . We show that our bounds may be nearly sharp for arbitrarily large hypergraphs and lattices. As an application, we prove that the number of maximal infeasible vectors x=1××n for a system of polymatroid inequalities does not exceed max{Q,logt/c(2Q,)}, where is the number of minimal feasible vectors for the system, , , and c(,) is the unique positive root of the equation 2c(c/log–1)=1. This bound is nearly sharp for the Boolean case ={0,1}n, and it allows for the efficient generation of all minimal feasible sets to a given system of polymatroid inequalities with quasi-polynomially bounded right-hand sides . This research was supported by the National Science Foundation (Grant IIS-0118635), and by the Office of Naval Research (Grant N00014-92-J-1375). The second and third authors are also grateful for the partial support by DIMACS, the National Science Foundation's Center for Discrete Mathematics and Theoretical Computer Science.Mathematics Subject Classification (2000):20E28, 20G40, 20C20  相似文献   
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