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准传递定向图上的Seymour点
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作者 李瑞娟 史杰 张新鸿 《高校应用数学学报(A辑)》 北大核心 2020年第2期245-252,共8页
有向图D是准传递的,如果对D中任意三个不同的顶点x, y和z,只要在D中存在弧xy, yz, x和z之间就至少存在一条弧. Seymour二次邻域猜想为:在任何一个定向图D中都存在一个顶点x,满足d^+D(x)d^++D(x).这里,定向图是指没有2圈的有向图.称满足S... 有向图D是准传递的,如果对D中任意三个不同的顶点x, y和z,只要在D中存在弧xy, yz, x和z之间就至少存在一条弧. Seymour二次邻域猜想为:在任何一个定向图D中都存在一个顶点x,满足d^+D(x)d^++D(x).这里,定向图是指没有2圈的有向图.称满足Seymour二次邻域猜想的点为Seymour点. Fisher证明了Seymour二次邻域猜想适用于竞赛图,也就是每个竞赛图至少包含一个Seymour点. Havet和Thomassé证明了,无出度为零的点的竞赛图至少包含两个Seymour点.注意到,竞赛图是准传递有向图的子图类.研究Seymour二次邻域猜想在准传递定向图上的正确性,通过研究准传递定向图与扩张竞赛图的Seymour点之间的关系,证明了准传递定向图上Seymour二次邻域猜想的正确性,得到:每个准传递定向图至少包含一个Seymour点;无出度为零的点的准传递定向图至少包含两个Seymour点. 展开更多
关键词 准传递定向图 Seymour二次邻域猜想 扩张竞赛图
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矩阵方程AX-X^(T)B=C的解 被引量:2
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作者 樊赵兵 卜长江 《大学数学》 2004年第5期100-102,共3页
通过引入矩阵的广义逆构造性地给出矩阵方程AX-X^(T)B=C的特解,同时通过不同的方法给出其所对应的齐次方程AX-X^(T)B=O解的两种不同形式.从而得到了矩阵方程AX-X^(T)B=C两种不同形式的解.
关键词 广义逆 矩阵方程 {1}逆
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Markov process functionals in finance and insurance 被引量:7
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作者 GENG Xian-min LI Liang 《Applied Mathematics(A Journal of Chinese Universities)》 SCIE CSCD 2009年第1期21-26,共6页
The Markov property of Markov process functionals which are frequently used in economy, finance, engineering and statistic analysis is studied. The conditions to judge Markov property of some important Markov process ... The Markov property of Markov process functionals which are frequently used in economy, finance, engineering and statistic analysis is studied. The conditions to judge Markov property of some important Markov process functionals are presented, the following conclusions are obtained: the multidimensional process with independent increments is a multidimensional Markov process; the functional in the form of path integral of process with independent increments is a Markov process; the surplus process with the doubly stochastic Poisson process is a vector Markov process. The conditions for linear transformation of vector Markov process being still a Markov process are given. 展开更多
关键词 Markov process functional process with independent increments risk process
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PARTITION A GRAPH WITH SMALL DIAMETER INTO TWO INDUCED MATCHINGS 被引量:6
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作者 杨爱峰 原晋江 《Applied Mathematics(A Journal of Chinese Universities)》 SCIE CSCD 2004年第3期245-251,共7页
Given a simple graph G and a positive integer k, the induced matching k-partition problem asks whether there exists a k-partition (V 1, V 2, ..., V k) of V(G) such that for each i(1≤i≤k), G[V i] is 1-regular. This p... Given a simple graph G and a positive integer k, the induced matching k-partition problem asks whether there exists a k-partition (V 1, V 2, ..., V k) of V(G) such that for each i(1≤i≤k), G[V i] is 1-regular. This paper studies the computational complexity of this problem for graphs with small diameters. The main results are as follows: Induced matching 2-partition problem of graphs with diameter 6 and induced matching 3-partition problem of graphs with diameter 2 are NP-complete; induced matching 2-partition problem of graphs with diameter 2 is polynomially solvable. 展开更多
关键词 induced matching PARTITION COLORING
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NEW METHODS FOR CHARACTERIZING D-η-PROPERLY PREQUASI-INVEX FUNCTIONS 被引量:4
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作者 Luo Hezhi Wu Huixian Zhu Yihua 《Applied Mathematics(A Journal of Chinese Universities)》 SCIE CSCD 2006年第1期107-112,共6页
The D-η-proper prequasi invexity of vector-valued functions is characterized by means of (weak) nearly convexity and density of sets. Under weaker assumptions, some equivalent conditions for D-η-proper prequasi-in... The D-η-proper prequasi invexity of vector-valued functions is characterized by means of (weak) nearly convexity and density of sets. Under weaker assumptions, some equivalent conditions for D-η-proper prequasi-invexity are derived. 展开更多
关键词 D-η-properly prequasi-invex function (weak) nearly convex set invex set lower D-semicontinuity density.
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GENERALIZED FUZZY FILTERS OF BL-ALGEBRAS 被引量:5
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作者 Ma Xueling Zhan Jianming Xu Yang 《Applied Mathematics(A Journal of Chinese Universities)》 SCIE CSCD 2007年第4期490-496,共7页
The concept of quasi-coincidence of a fuzzy interval value with an interval valued fuzzy set is considered. In fact, this is a generalization of quasi-coincidence of a fuzzy point with a fuzzy set. By using this new i... The concept of quasi-coincidence of a fuzzy interval value with an interval valued fuzzy set is considered. In fact, this is a generalization of quasi-coincidence of a fuzzy point with a fuzzy set. By using this new idea, the notion of interval valued (∈,∈ ∨q)-fuzzy filters in BL-algebras which is a generalization of fuzzy filters of BL-algebras, is defined, and related properties are investigated. In particular, the concept of a fuzzy subgroup with thresholds is extended to the concept of an interval valued fuzzy filter with thresholds in BL-algebras. 展开更多
关键词 FILTER interval valued (∈ ∨q)-fuzzy filter interval valued fuzzy filter with thresholds.
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ASYMPTOTIC SURROGATE CONSTRAINT METHOD AND ITS CONVERGENCE FOR A CLASS OF SEMI-INFINITE PROGRAMMING 被引量:2
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作者 Wan Zhongping Wu Guoming 《Applied Mathematics(A Journal of Chinese Universities)》 SCIE CSCD 1999年第4期485-491,共7页
A class of constrained semi-infinite minimax problem is transformed into a simple constrained problem,by means of discretization decomposition and maximum entropy method,making use of surrogate constraint.The paper de... A class of constrained semi-infinite minimax problem is transformed into a simple constrained problem,by means of discretization decomposition and maximum entropy method,making use of surrogate constraint.The paper deals with the convergence of this asymptotic approach method. 展开更多
关键词 Sem i-infinite m inim ax program m ing discretization decom position m ethod m axim um en-tropy m ethod surrogate constraint CONVERGENCE
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WAVELET ESTIMATION IN NONPARAMETRIC MODEL UNDER MARTINGALE DIFFERENCE ERRORS 被引量:3
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作者 梁汉营 张冬霞 吕保献 《Applied Mathematics(A Journal of Chinese Universities)》 SCIE CSCD 2004年第3期302-310,共9页
This paper is concerned with the heteroscedastic regression model Y i=g(x i)+σ iei(1?i?n) under correlated errors e i, where it is assumed that σ i Emphasis>/2 =f(u i), the design points (x i, ui) are known and n... This paper is concerned with the heteroscedastic regression model Y i=g(x i)+σ iei(1?i?n) under correlated errors e i, where it is assumed that σ i Emphasis>/2 =f(u i), the design points (x i, ui) are known and nonrandom, and g and f are unknown functions. Assuming that unobserved disturbances e i are martingale differences. The strong uniform convergence rates and r-th moment uniform convergence rates of wavelet estimator of g are investigated. Also, the strong uniform convergence rates are discussed for wavelet estimator of f. MR Subject Classification 62G05 Keywords regression function - martingale difference error - wavelet estimator - uniform convergence rate Partially supported by the National Natural Science Foundation of China (10171079). 展开更多
关键词 MR Subject Classification 62G05
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STABILITY ANALYSIS OF EQUILIBRIUM FOR MICROORGANISMS IN CONTINUOUS CULTURE 被引量:2
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作者 Li Xiaohong Feng Enmin Xiu Zhilong 《Applied Mathematics(A Journal of Chinese Universities)》 SCIE CSCD 2005年第4期377-383,共7页
The problem of equilibrium of non-linear dynamic system for microorganism in continuous culture is considered in this paper. The existence of equilibrium point is proved. The conclusion that the equilibrium is the con... The problem of equilibrium of non-linear dynamic system for microorganism in continuous culture is considered in this paper. The existence of equilibrium point is proved. The conclusion that the equilibrium is the continuous function of the dilution rate and substrate concentration in medium in a certain range is concluded. And the stability criterion of equilibrium is obtained. In theory, it explains the multiplicity shown in laboratory. 展开更多
关键词 equilibrium point STABILITY continuous culture.
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ASYMPTOTIC NORMALITY OF WAVELET ESTIMATOR IN HETEROSCEDASTIC REGRESSION MODEL 被引量:1
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作者 Liang Hanying Lu Yi 《Applied Mathematics(A Journal of Chinese Universities)》 SCIE CSCD 2007年第4期453-459,共7页
The following heteroscedastic regression model Yi = g(xi) +σiei (1 ≤i ≤ n) is 2 considered, where it is assumed that σi^2 = f(ui), the design points (xi,ui) are known and nonrandom, g and f are unknown f... The following heteroscedastic regression model Yi = g(xi) +σiei (1 ≤i ≤ n) is 2 considered, where it is assumed that σi^2 = f(ui), the design points (xi,ui) are known and nonrandom, g and f are unknown functions. Under the unobservable disturbance ei form martingale differences, the asymptotic normality of wavelet estimators of g with f being known or unknown function is studied. 展开更多
关键词 regression function martingale difference error wavelet estimator asymptotic normality.
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Hlder continuity for a class of X-elliptic equations with singular lower order term 被引量:1
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作者 JIN Yong-yang 《Applied Mathematics(A Journal of Chinese Universities)》 SCIE CSCD 2009年第1期56-64,共9页
The regularity for a class of X-elliptic equations with lower order termLu+vu=-∑i,j=1 mXj^*(aij(x)Xiu)+vu=μis studied, where X = {X1,..., Xm} is a family of locally Lipschitz continuous vector fields, v is in... The regularity for a class of X-elliptic equations with lower order termLu+vu=-∑i,j=1 mXj^*(aij(x)Xiu)+vu=μis studied, where X = {X1,..., Xm} is a family of locally Lipschitz continuous vector fields, v is in certain Morrey type space and μ a nonnegative Radon measure. The HSlder continuity of the solution is proved when μ satisfies suitable growth condition, and a converse result on the estimate of μ is obtained when u is in certain HSlder class. 展开更多
关键词 X-elliptic operator Hlder continuity Morrey type space
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BIFURCATION AND COMPLEXITY IN A RATIO-DEPENDENT PREDATOR-PREY CHEMOSTAT WITH PULSED INPUT 被引量:1
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作者 Zhao Zhong Song Xinyu 《Applied Mathematics(A Journal of Chinese Universities)》 SCIE CSCD 2007年第4期379-387,共9页
In this paper, a three dimensional ratio-dependent chemostat model with periodically pulsed input is considered. By using the discrete dynamical system determined by the stroboscopic map and Floquet theorem, an exact ... In this paper, a three dimensional ratio-dependent chemostat model with periodically pulsed input is considered. By using the discrete dynamical system determined by the stroboscopic map and Floquet theorem, an exact periodic solution with positive concentrations of substrate and predator in the absence of prey is obtained. When β is less than some critical value the boundary periodic solution (xs(t), O, zs(t)) is locally stable, and when β is larger than the critical value there are periodic oscillations in substrate, prey and predator. Increasing the impulsive period T the system undergoes a series of period-doubling bifurcation leading to chaos, which implies that the dynamical behaviors of the periodically pulsed ratio-dependent predator-prey ecosystem are very complex. 展开更多
关键词 chemostat model periodical solution stability bifurcation.
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Heat flow of harmonic maps from noncompact manifolds 被引量:1
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作者 WANG Meng LIU Xiao-feng 《Applied Mathematics(A Journal of Chinese Universities)》 SCIE CSCD 2008年第4期431-436,共6页
The global existence of the heat flow for harmonic maps from noncompact manifolds is considered. When L^m norm of the gradient of initial data is small, the existence of a global solution is proved.
关键词 heat flow noncompact complete manifold harmonic map
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ENUMERATION OF (0,1)-MATRICES WITH CONSTANT ROW AND COLUMN SUMS 被引量:1
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作者 Tan Zhonghua Gao Shanzhen Heinrich Niederhausen 《Applied Mathematics(A Journal of Chinese Universities)》 SCIE CSCD 2006年第4期479-486,共8页
Let fs,t(m, n) be the number of (0, 1) - matrices of size m × n such that each row has exactly s ones and each column has exactly t ones (sm = nt). How to determine fs,t(m,n)? As R. P. Stanley has obser... Let fs,t(m, n) be the number of (0, 1) - matrices of size m × n such that each row has exactly s ones and each column has exactly t ones (sm = nt). How to determine fs,t(m,n)? As R. P. Stanley has observed (Enumerative Combinatorics I (1997), Example 1.1.3), the determination of fs,t(m, n) is an unsolved problem, except for very small s, t. In this paper the closed formulas for f2,2(n, n), f3,2(m, n), f4,2(m, n) are given. And recursion formulas and generating functions are discussed. 展开更多
关键词 (0 1)-matrices labelled ball arrangement generating function.
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ON THE EXISTENCE OF INFINITELY MANY CRITICAL POINTS OF THE EVEN FUNCTIONAL integral from n=Q to (F(x,u,Du))+integral from n=■Q to (G(x,u))
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作者 严树森 《Acta Mathematica Scientia》 SCIE CSCD 1989年第2期231-240,共10页
In this paper we deal with the existence of infinitely many critical points of the even functional I(u)=integral from n=Q to (F(x,u,Du))+integral from n=(?)Q to (G(x,u)), u∈W^(1,p)(Ω),where G(x, u)=integral from n=o... In this paper we deal with the existence of infinitely many critical points of the even functional I(u)=integral from n=Q to (F(x,u,Du))+integral from n=(?)Q to (G(x,u)), u∈W^(1,p)(Ω),where G(x, u)=integral from n=o to u (g(x,t)dt), under the weak structure conditions on F(x, u, q) by the Mountain Pass Lemma. 展开更多
关键词 ON THE EXISTENCE OF INFINITELY MANY CRITICAL POINTS OF THE EVEN FUNCTIONAL integral from n=Q to x u Du ON THE EXISTENCE OF INFINITELY MANY CRITICAL POINTS OF THE EVEN FUNCTIONAL integral from n Q to x u
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INJECTIVE MAPS ON PRIMITIVE SEQUENCES OVER Z/(p^e)
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作者 Sun Zhonghua Qi Wenfeng 《Applied Mathematics(A Journal of Chinese Universities)》 SCIE CSCD 2007年第4期469-477,共9页
Let Z/(p^e) be the integer residue ring modulo p^e with p an odd prime and integer e ≥ 3. For a sequence a over Z/(p^e), there is a unique p-adic decomposition a- = a-0 +a-1 .p +… + a-e-l .p^e-1 where each a-... Let Z/(p^e) be the integer residue ring modulo p^e with p an odd prime and integer e ≥ 3. For a sequence a over Z/(p^e), there is a unique p-adic decomposition a- = a-0 +a-1 .p +… + a-e-l .p^e-1 where each a-i can be regarded as a sequence over Z/(p), 0 ≤ i ≤ e - 1. Let f(x) be a primitive polynomial over Z/(p^e) and G'(f(x),p^e) the set of all primitive sequences generated by f(x) over Z/(p^e). For μ(x) ∈ Z/(p)[x] with deg(μ(x)) ≥ 2 and gad(1 + deg(μ(x)),p- 1) = 1, setφe-1 (x0, x1,… , xe-1) = xe-1. [μ(xe-2) + ηe-3(x0, X1,…, xe-3)] + ηe-2(x0, X1,…, xe-2) which is a function of e variables over Z/(p). Then the compressing mapφe-1 : G'(f(x),p^e) → (Z/(p))^∞ ,a-→φe-1(a-0,a-1, … ,a-e-1) is injective. That is, for a-,b-∈ G'(f(x),p^e), a- = b- if and only if φe-1 (a-0,a-1, … ,a-e-1) = φe-1(b-0, b-1,… ,b-e-1). As for the case of e = 2, similar result is also given. Furthermore, if functions φe-1 and ψe-1 over Z/(p) are both of the above form and satisfy φe-1(a-0,a-1,…,a-e-1)=ψe-1(b-0, b-1,… ,b-e-1) for a-,b-∈G'(f(x),p^e), the relations between a- and b-, φe-1 and ψe-1 are discussed 展开更多
关键词 integer residue ring linear recurring sequence primitive sequence injective map.
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Bin-objective shape optimization based on linear programming model of arch dam
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作者 金海 林皋 阳明盛 《Journal of Harbin Institute of Technology(New Series)》 EI CAS 2007年第3期436-439,共4页
Bin-objective shape optimization of arch dam based on linear programming model is discussed to minimize both dam volume and maximal tensile stress.The importance of weight coefficient of the above two objectives is ch... Bin-objective shape optimization of arch dam based on linear programming model is discussed to minimize both dam volume and maximal tensile stress.The importance of weight coefficient of the above two objectives is chosen according to the value of importance ratio.The influence of weight coefficient to the optimization result is discussed in detail and the numerical example shows that both the model and method proposed is doable. 展开更多
关键词 OPTIMIZATION arch dam linear programming bin-objective
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Ass(M/N)and Ann(M/N)on the Noetherian Module M
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作者 黄天民 田维胜 《Chinese Quarterly Journal of Mathematics》 CSCD 1993年第4期83-88,共6页
Let R is a noetherian ring,M is a finitely generated R-module.This paper studies the relation between associated prime Ass(M/N)and annihilator Ann(M/N),and has given the necessary and sufficient conditions of Ass(M/N)... Let R is a noetherian ring,M is a finitely generated R-module.This paper studies the relation between associated prime Ass(M/N)and annihilator Ann(M/N),and has given the necessary and sufficient conditions of Ass(M/N)=Ann(M/N). 展开更多
关键词 associated prime ideal annilhilator primary decomposition primary submodule
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A note about the cyclotomic polynomial Φ_(pq)(x) and some related results
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作者 ZHU Feng-xiang QI Wen-feng 《Applied Mathematics(A Journal of Chinese Universities)》 SCIE CSCD 2008年第2期245-250,共6页
. The expression of cyclotomic polynomial Фpq (x) is concerned for a long time. A simple and explicit expression of Фpq (x) in Z[x] has been showed. The form of the factors of Фpq (x) over F2 and the upper, l... . The expression of cyclotomic polynomial Фpq (x) is concerned for a long time. A simple and explicit expression of Фpq (x) in Z[x] has been showed. The form of the factors of Фpq (x) over F2 and the upper, lower bounds of their Hamming weight are provided. 展开更多
关键词 cyclotomic polynomial Фpq(x) COEFFICIENT factor.
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NONTRIVIAL SOLUTIONS FOR A CLASS OF NON-DIVERGENCE EQUATIONS ON POLARIZABLE CARNOT GROUP
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作者 刘海峰 钮鹏程 《Applied Mathematics(A Journal of Chinese Universities)》 SCIE CSCD 2006年第2期157-164,共8页
Some new properties of polarizable Carnot group are given.By choosing a proper constant a nontrivial solution of a class of non-divergence Dirichlet problem on the polarizable Carnot group is constructed.Thus the mult... Some new properties of polarizable Carnot group are given.By choosing a proper constant a nontrivial solution of a class of non-divergence Dirichlet problem on the polarizable Carnot group is constructed.Thus the multi-solution property of corresponding non-homogeneous Dirichlet problem is proved and the best possible of LQ norm in the famous Alexandrov-Bakelman-Pucci type estimate is discussed. 展开更多
关键词 Dirichlet problem polarizable Carnot group Alexandrov-Bakelman-Pucci estimate.
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