检索结果-南通市图书馆

Minimal Elements in the poset of Graphic Sequences

在线全文

学校读者我要写书评

暂无评论

Journal of Mathematical Research and Exposition 2000年第2期20卷 171-176页

作者：李炯生胡跃进中国科学技术大学数学系合肥2300262 徽州师范专科学校数学系安徽黄山242700

A nonincreasing sequence ( of n nonnegative integers is said to be graphic if it is the degree sequence of a simple graph G of order n. The set of all graphic sequences of n terms with even sum 2m and trace f is a poset G_(n,m,f) under majorization relation. The paper characterizes the minimal elements in the poset G_(n,m,f) and determines the number of minimal elements in various posets of graphic sequences.

关键词： graph graphic sequence poset minimal elements.

Some Combinatorial Identities on Lattice-Point poset

在线全文

学校读者我要写书评

暂无评论

Journal of Mathematical Research with Applications 1998年第1期 39-44页

作者： Ma Xinrong (Department of Mathematics, Suzhou University, Suzhou 215006)

ＳｏｍｅＣｏｍｂｉｎａｔｏｒｉａｌＩｄｅｎｔｉｔｉｅｓｏｎＬａｔｉｃｅ－ＰｏｉｎｔＰｏｓｅｔ⒇ＭａＸｉｎｒｏｎｇ（ＤｅｐａｒｔｍｅｎｔｏｆＭａｔｈｅｍａｔｉｃｓ，ＳｕｚｈｏｕＵｎｉｖｅｒｓｉｔｙ，Ｓｕｚｈｏｕ２１５０... 详细信息

ＳｏｍｅＣｏｍｂｉｎａｔｏｒｉａｌＩｄｅｎｔｉｔｉｅｓｏｎＬａｔｉｃｅ－ＰｏｉｎｔＰｏｓｅｔ⒇ＭａＸｉｎｒｏｎｇ（ＤｅｐａｒｔｍｅｎｔｏｆＭａｔｈｅｍａｔｉｃｓ，ＳｕｚｈｏｕＵｎｉｖｅｒｓｉｔｙ，Ｓｕｚｈｏｕ２１５００６）ＡｂｓｔｒａｃｔＴｈｉｓｐａ...

关键词： poset identity convolution.

Cyclic posets and triangulation clusters

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Science China Mathematics 2019年第7期62卷 1289-1316页

作者： Kiyoshi Igusa Gordana Todorov Department of Mathematics Brandeis University Waltham MA 02454 USA Department of Mathematics Northeastern University Boston MA 02115 USA

Triangulated categories coming from cyclic posets were originally introduced by the authors in a previous paper as a generalization of the constructions of various triangulated categories with cluster *** give an overview, and then analyze "triangulation clusters" which are those corresponding to topological triangulations of the 2-disk. Locally finite nontriangulation clusters give topological triangulations of the "cactus space" associated to the "cactus cyclic poset".

关键词： cactus cyclic poset cluster structure triangulated categories Frobenius categories cocycle

The Semimodularity of Cardinal Power of posets

在线全文

学校读者我要写书评

暂无评论

Chinese Quarterly Journal of Mathematics 1997年第1期12卷 47-51,页

作者：胡长流

Let X,Y be any posets,the semimodularity of cardinal power Yx with base Y and exponent X is studied. Some necessary or sufficient conditions for Yx to be semimodular are gaven,

关键词： poset cardinal power of posets seimodularity

Algebra and Coalgebra on posets

在线全文

学校读者我要写书评

暂无评论

Open Journal of Applied Sciences 2022年第7期12卷 1232-1242页

作者： Rongrong Yuan Huilan Li School of Mathematics and Statistics Shandong Normal University Jinan China

A lot of combinatorial objects have algebra and coalgebra structures and posets are important combinatorial objects. In this paper, we construct algebra and coalgebra structures on the vector space spanned by posets. Firstly, by associativity and the unitary property, we prove that the vector space with the conjunction product is a graded algebra. Then by the definition of free algebra, we prove that the algebra is free. Finally, by the coassociativity and the counitary property, we prove that the vector space with the unshuffle coproduct is a graded coalgebra.

关键词： Conjunction Product Unshuffle Coproduct poset Graded Free

Graph Properties and Stratified Presentations of Partially Ordered Sets

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Algebra Colloquium 2016年第1期23卷 51-63页

作者： Jin Guo Tongsuo Wu Department of Mathematics Shanghai Jiaotong University Shanghai 200240 China

In this paper, we introduce some new definitions such as the U＊L＊ condition to describe the zero-divisor graph G = F（P） of a poser P, and give a new and quick proof to a main result in [2, 4]. By deleting a typical vertex with least degree, we provide an algorithm for finding a maximum clique of a finite graph G. We study some properties of the zero-divisor graphs of posets concerning diameters and girths. We also provide stratified presentations of posets.

关键词： poset chromatic number clique number deleting method stratified presentation

Polynomials with Palindromic and Unimodal Coefficients

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Acta Mathematica Sinica,English Series 2015年第4期31卷 565-575页

作者： Hua SUN Yi WANG Hai Xia ZHANG School of Mathematical Sciences Dalian University of Technology

Let f（q） = arq^r ＋…＋asqs, with ar ≠ 0 and as ≠ 0, be a real polynomial. It is a palindromic polynomial of darga n if r＋s= n and ar＋i =as-i for all i. Polynomials of darga n form a linear subspace Pn（q） of R（q）n＋l of dimension [n/2] ＋ 1. We give transition matrices between two bases {q^j（1 ＋ q ＋… q^n-2j）}, {q^j（1 ＋ q）^n-2j } and the standard basis {q^j（1 ＋ q^n-2j）} of Pn （q）. We present some characterizations and sufficient conditions for palindromic polynomials that can be expressed in terms of these two bases with nonnegative coefficients. We also point out the link between such polynomials and rank-generating functions of posets.

关键词： Unimodal sequence palindromic sequence linear space poset

Strong Sperner property of the subgroup lattice of an Abelian p-group

在线全文

学校读者我要写书评

暂无评论

Science China Mathematics 2000年第7期43卷 693-702页

作者：王军王毅 Department of Applied Mathematics Dalian University of Technology Dalian 116024 China

Letn andk be arbitrary positive integers,p a prime number and L(k n)(p) the subgroup lattice of the Abelianp-group (Z/p k ) n . Then there is a positive integerN(n,k) such that whenp N(n,k),L (k N )(p) has the strong ... 详细信息

关键词： poset subgroup lattice Sperner property.

Representations of a Pair of Posers

在线全文

学校读者我要写书评

暂无评论

Acta Mathematica Sinica,English Series 1995年第4期11卷 408-416页

In this article we determine the pairs of posets which are finitely represented.

关键词： poset Representation Finitely represented