The quasi‐randomness of hypergraph cut properties

Let satisfy and suppose a k‐uniform hypergraph on n vertices satisfies the following property; in any partition of its vertices into k sets of sizes , the number of edges intersecting is (asymptotically) the number one would expect to find in a random k‐uniform hypergraph. Can we then infer that H is quasi‐random? We show that the answer is negative if and only if . This resolves an open problem raised in 1991 by Chung and Graham [J AMS 4 (1991), 151–196]. While hypergraphs satisfying the property corresponding to are not necessarily quasi‐random, we manage to find a characterization of the hypergraphs satisfying this property. Somewhat surprisingly, it turns out that (essentially) there is a unique non quasi‐random hypergraph satisfying this property. The proofs combine probabilistic and algebraic arguments with results from the theory of association schemes. © 2011 Wiley Periodicals, Inc. Numer Methods Partial Differential Eq, 2011     

Density of finite rank operators in the Banach space of p-compact operators

A Banach space X is said to have the kp-approximation property (kp-AP) if for every Banach space Y, the space F(Y,X) of finite rank operators is dense in the space Kp(Y,X) of p-compact operators endowed with its natural ideal norm kp. In this paper we study this notion that has been previously treated by Sinha and Karn (2002) in [15]. As application, the kp-AP of dual Banach spaces is characterized via density of finite rank operators in the space of quasi p-nuclear operators for the p-summing norm. This allows to obtain a relation between the kp-AP and Saphar's approximation property. As another application, the kp-AP is characterized in terms of a trace condition. Finally, we relate the kp-AP to the (p,p)-approximation property introduced in Sinha and Karn (2002) [15] for subspaces of Lp(μ)-spaces.     

Approximate selections of almost lower semicontinuous multimaps in C-spaces

We study the relations of almost lower semicontinuity, lower semicontinuity and other generalized lower semicontinuity; then we establish a new approximate selection theorem for almost lower semicontinuous multimaps with the generalized Zima type condition in C$C$-spaces. Our result unify and extend the approximate selection theorems in many published works.     

Representation of quasi‐monotone functionals by families of separating hyperplanes

We characterize when the level sets of a continuous quasi‐monotone functional defined on a suitable convex subset of a normed space can be uniquely represented by a family of bounded continuous functionals. Furthermore, we investigate how regularly these functionals depend on the parameterizing level. Finally, we show how this question relates to the recent problem of property elicitation that simultaneously attracted interest in machine learning, statistical evaluation of forecasts, and finance.     

On extended versions of Dancs-Hegedüs-Medvegyev’s fixed-point theorem

In this article, we establish some fixed-point (known also as critical point, invariant point) theorems in quasi-metric spaces. Our results unify and further extend in some regards the fixed-point theorem proposed by Dancs, S.; Hegedüs, M.; Medvegyev, P. (A general ordering and fixed-point principle in complete metric space. Acta Sci. Math. 1983;46:381–388), the results given by Khanh, P.Q., Quy D.N. (A generalized distance and enhanced Ekeland?s variational principle for vector functions. Nonlinear Anal. 2010;73:2245–2259), the preorder principles established by Qiu, J.H. (A pre-order principle and set-valued Ekeland variational principle. J. Math. Anal. Appl. 2014;419:904–937) and the results obtained by Bao, T.Q., Mordukhovich, B.S., Soubeyran, A. (Fixed points and variational principles with applications to capability theory of wellbeing via variational rationality. Set-Valued Var. Anal. 2015;23:375–398). In addition, we provide examples to illustrate that the improvements of our results are significant.     

拟Z-代数domain

基于一般子集系统Z,引入拟Z-代数domain的概念,研究了拟Z-代数domain的一些映射性质,并讨论了拟Z-代数domain与拟Z-连续domain之间的关系及拟Z-代数domain的乘积。     

碳纳米管的拉曼散射

本文报道了经电弧放电产生的阴极沉积物外壳与内芯，以及石墨电极的喇曼光谱。     

广义投影梯度型约束变尺度法

本文将广义投影梯度方向移植到约束变尺度算法之中，得到了一类新型算法：广义投影梯度型约束变尺度算法，并成功的使用了Ａｒｍｉｊｏ规则．该算法将广义投影类可行方向法和约束变尺度算法的优点溶为一体．并且由于使用了拟下降的概念，算法变得更为灵活．     

随机积分的拟必然逼近

该文证明了随机积分的拟必然逼近. 基于此,作者用更简化的方法得到并拓展了文献[8]的主要结果. 并且, 该方法可以应用到光滑两参数鞅情形.     

余代数和Morita-Takeuchi关系

本文证明了若余代数Ｃ和Ｄ是Ｍｏｒｉｔａ Ｔａｋｅｕｃｈｉ等价的，则Ｃ的子余代数格和Ｄ的子余代数格同构．设ＭΓ，ＮΓ是拟有限右Γ 余模，则（ｈ－Γ（Ｍ，Ｍ），ｈ－Γ（Ｎ，Ｎ）；ｈ－Γ（Ｎ，Ｍ），ｈ－Γ（Ｍ，Ｎ）；ｆ，ｇ）有Ｍｏｒｉｔａ Ｔａｋｅｕｃｈｉ关系．并给出了此Ｍ Ｔ关系是Ｍ Ｔ等价条件的及由已知的Ｍ Ｔ关系构造新的Ｍ Ｔ关系的方法．