In contrast to other nonparameteric regression techniques, smoothing parameter selection for spline estimators can be performed not only by employing criteria that approximate the average mean squared error (e.g. generalized cross validation), but also by making use of the maximum likelihood (or empirical Bayes) paradigm. In the later case, the function to be estimated is assumed to be a realization of some stochastic process, rather than from a certain class of smooth functions. Under this assumption both smoothing parameter selectors for spline estimators are well-studied and known to perform similar. A more interesting problem is the properties of smoothing parameter estimators in the frequentist framework, that is if the underlying function is non-random. In this talk we discuss the asymptotic properties of both smoothing parameter selection criteria for general low-rank (or so-called penalized) spline smoothers in

报告人： Professor Li Deli(加拿大Lakehead大学数学科学系教授）报告(一)题目：On the Central Limit Theorem along Subsequencesof Sums of Independent Random Variables(独立随机变量子序列的中心极限定理)时间：2012年5月25日（周五）下午 4:00开始报告(二)题目：A Comparison Theorem for the Law of LargeNumbers in Banach Spaces(Banach空间关于大数定律的比较定理)时间：2012年5月31日（周四）上午9:00开始地点：数学...

报告人：杨启帆教授（浙江大学）题目： 从数学建模看数学教育在人才培养中的作用时间：2012年5月21日，星期一上午10：00—11：00地点：数学系致远楼107欢迎各位参加

数学系（致远楼）107 欢迎广大师生参加 数学系、数学所 摘要： Given a vector space, its affinization is the direct sum of its negative, positive and zero parts. I recently found that on the tensor algebra of the negative part of the affinization, there is an algebraic structure satisfying the axioms for open-string vertex algebras (algebras introduced by Kong and me in 2004) and also an additional meromorphicity property. I call such an algebra a meromorphic open-string vertex algebra. A meromorphic open-string vertex algebra does not satisfy the Jacobi identity, the commutator formula, locality, commutativity, skew-symmetry or even the associator formula. But it still satisfies the most fundamental property for a quantum field theory: the existence of operator product expansion. In fact, it satisfies associativity, a stronger property implies the operator product expansion

Motivated by group algebra codes, permutation codes are introduced and self-dual permutation codes are studied. Further, a characterization of indecomposable orthogonal decompositions of symmetric semisimple modules and a criterion for the hyperbolic symmetric semisimple modules are obtained, and some applications to the self-dual permutation codes are shown

报告人：范更华福州大学教授, 副校长全国政协委员Journal of Graph Theory 常务编委范更华教授曾经获得国家杰出青年基金入选科学院百人工程教育部科技一等奖(单独)国家自然科学二等奖(单独)报告题目：Integral Flows时间：2012年5月7日星期一下午3：30开始地点: 数学系致远楼107

In this talk, we will brief introduce the loop group methods for CMC surfaces. The main steps of the loop group procedure will be discussed

致远楼 107 摘要： We will establish a bijective correspondence between finite type associative cones in $/R^7$ and their spectral data, which consists of a hexagonal algebraic curve and a planar flow of line bundles in its Jacobian. We characterize the spectral data by identifying various symmetries on them. We prove generic smoothness of these spectral curves, compute their genus, and compute the dimension of the moduli of such curves. Then we identify a Prym-Tjurin subtorus of the Jacobian, in which the direction of the flow must lie, and compute its dimension. Finally we characterize finite type special Lagrangian cones in $/C^3$ as a subclass of such associative cones in terms of the spectral data. These computations are mainly motivated by Hitchin's recent work on G_2 spectral curves and Langland duality.