首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 15 毫秒
1.
In this paper, we introduce a multipermutation-based intersection theorem on the product space of several unit simplices, called the simplotope. This theorem gives a substantial generalization of an intersection result of Scarf on the unit simplex (Ref. 1). By using this new result, we also obtain a multipermutation-based generalization of the Brouwer fixed-point theorem on the simplotope. Furthermore, we apply this new result to an economic equilibrium model with indivisibilities and obtain an equilibrium existence theorem.  相似文献   

2.
    
We survey some geometric and analytic results under the assumptions of combinatorial curvature bounds for planar/semiplanar graphs and curvature dimension conditions for general graphs.  相似文献   

3.
Constant composition codes(CCCs)are a new generalization of binary constant weight codes and have attracted recent interest due to their numerous applications. In this paper, a new combinatorial approach to the construction of CCCs is proposed, and used to establish new optimal CCCs.  相似文献   

4.
    
We present a recursive construction of a (2t + 1)‐wise uniform set of permutations on 2n objects using a combinatorial design, a t‐wise uniform set of permutations on n objects and a (2t + 1)‐wise uniform set of permutations on n objects. Using the complete design in this procedure gives a t‐wise uniform set of permutations on n objects whose size is at most t2n, the first non‐trivial construction of an infinite family of t‐wise uniform sets for . If a non‐trivial design with suitable parameters is found, it will imply a corresponding improvement in the construction. © 2013 Wiley Periodicals, Inc. Random Struct. Alg., 46, 531–540, 2015  相似文献   

5.
Optical orthogonal code (OOC) has good correlation properties. It has many important applications in a fiber-optic code-division multiple access channel. In this paper, a combinatorial construction for optimal(15p, 5,1) optical orthogonal codes withp congruent to 1 modulo 4 and greater than 5 is given by applying Weil's Theorem. From this, whenv is a product of primes congruent to 1 modulo 4 and greater than 5, an optimal (15v, 5, 1)-OOC can be obtained by applying a known recursive construction.  相似文献   

6.
    
Recently, two new constructions of disjoint difference families in Galois rings were presented by Davis, Huczynska, and Mullen and Momihara. Both were motivated by a well‐known construction of difference families from cyclotomy in finite fields by Wilson. It is obvious that the difference families in the Galois ring and the difference families in the finite field are not equivalent. A related question, which is in general harder to answer, is whether the associated designs are isomorphic or not. In our case, this problem was raised by Davis, Huczynska, and Mullen. In this paper, we show that, in most cases, the 2‐ designs arising from the difference families in Galois rings and those arising from the difference families in finite fields are nonisomorphic by comparing their block intersection numbers.  相似文献   

7.
The convergence of the Luus-Jaakola search method for unconstrained optimization problems is established.Notation E n Euclideann-space - f Gradient off(x) - 2 f Hessian matrix - (·) T Transpose of (·) - I Index set {1, 2, ...,n} - [x i1 *(j) ] Point around which search is made in the (j + 1)th iteration, i.e., [x 1l *(j) ,x 2l *(j) ,...,x n1 *(j) ] - r i (i) Range ofx il *(i) in the (j + 1)th iteration - l 1 mini {r i (0) } - l 2 mini {r i (0) } - A j Region of search in thejth iteration, i.e., {x E n:x il *(j-1) –0.5r i (j-1) x ix il *(j-1) +0.5r i (j-1) ,i I} - S j Closed sphere with center origin and radius j - Reduction factor in each iteration - 1– - (·) Gamma function Many discussions with Dr. S. N. Iyer, Professor of Electrical Engineering, College of Engineering, Trivandrum, India, are gratefully acknowledged. The author has great pleasure to thank Dr. K. Surendran, Professor, Department of Electrical Engineering, P.S.G. College of Technology, Coimbatore, India, for suggesting this work.  相似文献   

8.
宋艳红  单墫 《大学数学》2005,21(3):63-66
采用组合的方法,对∑nk=0n+kknk(m-1)n-k=∑nk=0nk2mk这一等式提供了一种全新的证明.此外,还提供了一种完全不用微积分的代数证明.  相似文献   

9.
Kurzweil-Henstock integrals related to local systems and the wide Denjoy integral are discussed in the frame of their comparability and compatibility. Dedicated to the memory of Ralph Henstock (1923–2007)  相似文献   

10.
C. Radoux (J. Comput. Appl. Math., 115 (2000) 471-477) obtained a computational formula of Hankel determinants on some classical combinatorial sequences such as Catalan numbers and polynomials, Bell polynomials, Hermite polynomials, Derangement polynomials etc. From a pair of matrices this paper introduces two kinds of numbers. Using the first kind of numbers we give a unified treatment of Hankel determinants on those sequences, i.e., to consider a general representation of Hankel matrices on the first kind of numbers. It is interesting that the Hankel determinant of the first kind of numbers has a close relation that of the second kind of numbers.  相似文献   

11.
The strong conical hull intersection property for convex programming   总被引:2,自引:0,他引:2  
The strong conical hull intersection property (CHIP) is a geometric property of a collection of finitely many closed convex intersecting sets. This basic property, which was introduced by Deutsch et al. in 1997, is one of the central ingredients in the study of constrained interpolation and best approximation. In this paper we establish that the strong CHIP of intersecting sets of constraints is the key characterizing property for optimality and strong duality of convex programming problems. We first show that a sharpened strong CHIP is necessary and sufficient for a complete Lagrange multiplier characterization of optimality for the convex programming model problem where C is a closed convex subset of a Banach space X, S is a closed convex cone which does not necessarily have non-empty interior, Y is a Banach space, is a continuous convex function and g:XY is a continuous S-convex function. We also show that the strong CHIP completely characterizes the strong duality for partially finite convex programs, where Y is finite dimensional and g(x)=−Ax+b and S is a polyhedral convex cone. Global sufficient conditions which are strictly weaker than the Slater type conditions are given for the strong CHIP and for the sharpened strong CHIP. The author is grateful to the referees for their constructive comments and valuable suggestions which have contributed to the final preparation of the paper.  相似文献   

12.
Qualitatively independent systems, a previously recognized type of combinatorial design, have been recently shown to have industrial applications involving the testing of complex systems. For these applications, even small reductions on the size of a qualitatively independent system can be significant. This article discusses some new techniques that result in reduced constructions. © 1998 John Wiley & Sons, Inc. J Combin Designs 6: 411–416, 1998  相似文献   

13.
基于组合过程模型给出其轨道对目标集的首次通过概率及首中点的分布函数 ,并由此给出直线上n步随机游动的首次通过概率及首中点分布函数的一类显式 .  相似文献   

14.
In this paper, the fine triangle intersection problem for a pair of maximum kite packings is investigated. Let Fin(v) = {(s,t) : a pair of maximum kite packings of order v intersecting in s blocks and s+t triangles}. Let Adm(v) = {(s, t) : s + t ≤ bv , s,t are non-negative integers}, where b v = v(v 1)/8 . It is established that Fin(v) = Adm(v)\{(bv-1, 0), (bv-1,1)} for any integer v ≡ 0, 1 (mod 8) and v ≥ 8; Fin(v) = Adm(v) for any integer v ≡ 2, 3, 4, 5, 6, 7 (mod 8) and v ≥ 4.  相似文献   

15.
Alon, Babai and Suzuki proved the following theorem: Let p be a prime and let K, L be two disjoint subsets of {0, 1, ... , p – 1}. Let |K| = r, |L| = s, and assume r(s – r + 1) p – 1 and n s + k r where k r is the maximal element of K. Let be a family of subsets of an n-element set. Suppose that (i) |F| K (mod p) for each F ;(ii) |E F| L (mod p) for each pair of distinct sets E, F . Then
They conjectured that the condition that r(s – r + 1) p – 1 in the theorem can be dropped and the same conclusion should hold. In this paper we prove that the same conclusion holds if the two conditions in the theorem, i.e. r(s – r + 1) p – 1 and n s + k r are replaced by a single more relaxed condition 2sr n.  相似文献   

16.
Let f:XSbe a projective morphism of Noetherian schemes. We assume fpurely of relative dimension dand finite Tor-dimensional. We associate to d+1 invertible sheaves on Xa line bundle I X/S ( ) on Sdepending additively on the , commuting to good base changes and which represents the integral along the fibres of fof the product of the first Chern classes of the . If d=0, I X/S ( ) is the norm N X/S ( ).  相似文献   

17.
    
A Hankel type determinant solution for an integrable semi-discrete equation is presented. As an application, the relations between the solution and combinatorial numbers are discussed, which lead to new combinatorial numbers. The so-called Motzkin-like numbers are obtained, and the corresponding combinatorial interpretation is given. Additionally, it is also shown that some lattice paths have connections with the special solution.  相似文献   

18.
In this paper we describe a decision-theoretic framework for comparing a number of heuristics in terms of accuracy for a given combinatorial optimization problem. The procedure takes both expected accuracy and downside risk into account and is quite easy to implement.  相似文献   

19.
    
Let Ψ(t,k) denote the set of pairs (v,λ) for which there exists a graphical t‐(v,k,λ) design. Most results on graphical designs have gone to show the finiteness of Ψ(t,k) when t and k satisfy certain conditions. The exact determination of Ψ(t,k) for specified t and k is a hard problem and only Ψ(2,3), Ψ(2,4), Ψ(3,4), Ψ(4,5), and Ψ(5,6) have been determined. In this article, we determine completely the sets Ψ(2,5) and Ψ(3,5). As a result, we find more than 270,000 inequivalent graphical designs, and more than 8,000 new parameter sets for which there exists a graphical design. Prior to this, graphical designs are known for only 574 parameter sets. © 2006 Wiley Periodicals, Inc. J Combin Designs 16: 70–85, 2008  相似文献   

20.
将软集合理论应用到可换BCI-代数中,给出了软可换BCI-代数的概念,讨论了软可换BCI-代数和软BCI-代数之间的关系,研究了软可换BCI-代数的扩展交、限制交、限制并以及限制差分等性质.最后,研究了软可换BCI-代数的同态性质.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号