On coloring numbers of graph powers

The weak $r$-coloring numbers ${\mathrm{wcol}}_r\left(G\right)$ of a graph $G$ were introduced by the first two authors as a generalization of the usual coloring number $\mathrm{col}\left(G\right)$, and have since found interesting theoretical and algorithmic applications. This has motivated researchers to establish strong bounds on these parameters for various classes of graphs.Let $G^p$ denote the $p$th power of $G$. We show that, all integers $p>0$ and $\Delta \ge 3$ and graphs $G$ with $\Delta \left(G\right)\le \Delta$ satisfy $\mathrm{col}\left(G^p\right)\in O\left(p\cdot {\mathrm{wcol}}_{\lceil p∕2\rceil }\left(G\right){(\Delta -1)}^{\lfloor p∕2\rfloor }\right)$; for fixed tree width or fixed genus the ratio between this upper bound and worst case lower bounds is polynomial in $p$. For the square of graphs $G$, we also show that, if the maximum average degree $2k-2<\mathrm{mad}\left(G\right)\le 2k$, then $\mathrm{col}\left(G^2\right)\le (2k-1)\Delta \left(G\right)+2k+1$.     

Intertwining wavelets or multiresolution analysis on graphs through random forests

We propose a new method for performing multiscale analysis of functions defined on the vertices of a finite connected weighted graph. Our approach relies on a random spanning forest to downsample the set of vertices, and on approximate solutions of Markov intertwining relation to provide a subgraph structure and a filter bank leading to a wavelet basis of the set of functions. Our construction involves two parameters q and $q^{\prime }$. The first one controls the mean number of kept vertices in the downsampling, while the second one is a tuning parameter between space localization and frequency localization. We provide an explicit reconstruction formula, bounds on the reconstruction operator norm and on the error in the intertwining relation, and a Jackson-like inequality. These bounds lead to recommend a way to choose the parameters q and $q^{\prime }$. We illustrate the method by numerical experiments.     

零售商信息分享对双渠道绿色供应链绩效影响研究

研究了零售商市场需求预测信息分享对双渠道绿色供应链绩效的影响。运用不完全信息动态博弈方法建立并求解零售商信息分享和信息不分享下的绿色供应链决策模型,得到贝叶斯均衡解和各方最优期望利润。研究发现:在双渠道绿色供应链中,若零售商对市场需求预测较为乐观,信息分享使得制造商更有动机提高产品绿色度;此外零售商信息分享总是有利于制造商利润增加,但并非总是使得零售商利润损失。当制造商绿色投资效率较高时,信息分享使得零售商利润增加,反之,信息分享使得零售商利润降低。对整个绿色供应链利润的影响取决于渠道间竞争强度、直销渠道市场份额及制造商绿色投资效率。最后用数值仿真验证了模型和结论的有效性。     

The Generalized Order Tensor Complementarity Problems

The main propose of this paper is devoted to studying the solvability of the generalized order tensor complementarity problem. We define two problems: the generalized order tensor complementarity problem and the vertical tensor complementarity problem and show that the former is equivalent to the latter. Using the degree theory, we present a comprehensive analysis of existence, uniqueness and stability of the solution set of a given generalized order tensor complementarity problem.     

椰心叶甲虫综合防治脉冲动力学模型的周期解

椰心叶甲虫是棕榈科植物最主要的害虫之一.论文针对两类寄生蜂攻击椰心叶甲虫不同年龄阶段的特点,建立了阶段结构的脉冲定期喷洒药物和释放天敌的综合防治模型.通过重合度理论和分析工具,证明了该模型周期解的存在性,给出了周期解存在的充分条件,并通过数值模拟验证了理论结果的有效性.     

The chromatic number of random Borsuk graphs

We study a model of random graph where vertices are n i.i.d. uniform random points on the unit sphere S^d in , and a pair of vertices is connected if the Euclidean distance between them is at least 2??. We are interested in the chromatic number of this graph as n tends to infinity. It is not too hard to see that if ?>0 is small and fixed, then the chromatic number is d+2 with high probability. We show that this holds even if ?→0 slowly enough. We quantify the rate at which ? can tend to zero and still have the same chromatic number. The proof depends on combining topological methods (namely the Lyusternik–Schnirelman–Borsuk theorem) with geometric probability arguments. The rate we obtain is best possible, up to a constant factor—if ?→0 faster than this, we show that the graph is (d+1)‐colorable with high probability.25     

平面n次微分系统高次奇点的拓扑结构

本文讨论了平面n次微分系统高次奇点的拓扑结构,并给出了按右端多项式系数的判断准则.     

Prime Space of Lattice Implication Algebras

1.IntroductionPeoplehavepaidmoreattentiontolathcevaluedlogicsystem,whichwillbecomemuchbetterlogicalsystemforintelligentcomputer.InreferenceL1JXuYangpresentanalgebrastructure-latticeimplicationalgebrabycomblngthelatticewithimplicationalgebraastruevaluefieldoflatticevaluedlogicaIsystem.Afterthat,westudytheimplicationhomomor-phism,congruencerelationsandalgebraicstructureoflatticeimplicationalgebraanddiscussthefirstorderlogicalsystemFMbasedonlatticeimplicationalgebras,andobtainedseveralimpor-ta…     

关于映射同伦类的拓扑熵

设ｆ：Ｔ＾ｍ→Ｔ＾ｍ为ｍ维环面自映射，Ｎ＾∞（ｆ）是ｆ的渐近Ｎｉｅｌｓｅｎ数，本文应用Ｎｉｅｌｓｅｎ不动点理论，给出了ｌｏｇＮ＾∞（ｆ）是ｆ的同伦类的拓扑熵的最好下界的一个充要条件；并通过在齐性空间上引入等价度量，将此结论推广到了幂零流形自映射的情形。