球形零件拉深过程中克服内皱的平面压边力确定

本文利用修正了的内皱模型，结合拉深过程中的几何条件及应力应变分析，推导了在平面压边情况下球形零件拉深过程中不发生内皱的判据;进而求解出拉深过程中克服内皱的最小压边力．所得公式可用于模具设计或供软件开发参考．     

PLUG-IN ESTIMATION OF GENERAL LEVEL SETS

Given an unknown function (e.g. a probability density, a regression function, …) f and a constant c, the problem of estimating the level set L(c) ={f≥c} is considered. This problem is tackled in a very general framework, which allows f to be defined on a metric space different from . Such a degree of generality is motivated by practical considerations and, in fact, an example with astronomical data is analyzed where the domain of f is the unit sphere. A plug‐in approach is followed; that is, L(c) is estimated by L_n(c) ={f_n≥c} , where f_n is an estimator of f. Two results are obtained concerning consistency and convergence rates, with respect to the Hausdorff metric, of the boundaries ?L_n(c) towards ?L(c) . Also, the consistency of L_n(c) to L(c) is shown, under mild conditions, with respect to the L₁ distance. Special attention is paid to the particular case of spherical data.     

SL(2,R)上球函数的求和定理

基于经典的Fourier级数求和法,利用逼近恒同核与函数做卷积和球函数的Fourier展开公式给出了SL(2,R)上球函数的一般求和定理.     

球面径向基函数插值逼近的误差估计

研究了球面上由不同光滑度的核所生成且嵌套的两个再生核Hilbert空间之间的插值逼近问题．证明了一个空间的函数可用光滑性更好的子空间中的函数进行插值逼近，并给出了插值误差的上界估计．     

新型高校智库开展协同创新的探索与思考--以浙江师范大学非洲研究院为个案

新型高校智库建设面临重要契机。以浙江师范大学非洲研究与中非合作协同创新中心为个案,探讨高校智库开展协同创新的紧迫性和可行性,在现状分析的基础上,提出“服务国家战略,创建互动合作机制”、“服务地方建设,深化校地协同模式”、“服务高校发展,强化多元学科融合”等建议,以期强化高校智库的协同创新,完善智库建设,提升软实力。     

Modes of Cognitive Praxis in Transnational Alternative Policy Groups

Abstract

Transnational alternative policy groups (TAPGs) are networks and centres within and around which counter-hegemonic knowledge is produced and mobilized among subaltern communities and critical social movements. Based on in-depth interviews with practitioners at 16 TAPGs, this article presents eight modes of cognitive praxis and discusses how they appear in the work of alternative policy groups. The eight modes are not sealed off from each other, but overlap and interpenetrate. In combination, these modes of cognitive praxis strive to produce transformative knowledge concomitantly with knowledge-based transformation. The analysis evidences tracings of a double dialectic in the cognitive praxis of alternative policy groups: a dialectic of theory and practice, and one of dialogue. It is in a forward movement—fostering solidaristic dialogue among counterpublics in combination with the iterative integration of theory and practice—that alternative knowledge makes its indispensable contribution to counter-hegemony.     

面向决策的美国一流智库智慧产品生产流程研究

随着世界范围内智库在政府决策过程中日益突出其影响力,中国政府对智库建设也给予高度重视与支持.美国智库不仅起步早、数量多,而且形成了一批国际影响力强的一流智库,为中国智库建设提供了良好的借鉴经验.文章从信息资源角度,认为美国一流智库产生的关键在于科学、完善的智慧产品生产流程,按照美国智库隶属机构的不同,选取兰德公司、布鲁金斯学会和胡佛研究所三所美国一流智库为代表,分析美国一流智库智慧产品生产的一般流程,包括课题选择、资料收集、研究分析、转识成智等关键过程.通过对关键过程的详细分析和案例介绍,以期为中国特色新型智库建设提供借鉴.     

Testing high-dimensional normality based on classical skewness and Kurtosis with a possible small sample size

Abstract

By using the idea of principal component analysis, we propose an approach to applying the classical skewness and kurtosis statistics for detecting univariate normality to testing high-dimensional normality. High-dimensional sample data are projected to the principal component directions on which the classical skewness and kurtosis statistics can be constructed. The theory of spherical distributions is employed to derive the null distributions of the combined statistics constructed from the principal component directions. A Monte Carlo study is carried out to demonstrate the performance of the statistics on controlling type I error rates and a simple power comparison with some existing statistics. The effectiveness of the proposed statistics is illustrated by two real-data examples.     

Supersmooth testing on the sphere over analytic classes

We consider the nonparametric goodness-of-fit test of the uniform density on the sphere when we have observations whose density is the convolution of an error density and the true underlying density. We will deal specifically with the supersmooth error case which includes the Gaussian distribution. Similar to deconvolution density estimation, the smoother the error density the harder is the rate recovery of the test problem. When considering nonparametric alternatives expressed over analytic classes, we show that it is possible to obtain original separation rates much faster than any logarithmic power of the sample size according to the ratio of the regularity index of the analytic class and the smoothness degree of the error. Furthermore, we show that our fully data-driven statistical procedure attains these optimal rates.     

夫琅和费衍射区内的Talbot效应

本文对球面波照明一维振幅型光栅时，在夫琅和费衍射区内的Ｔａｌｂｏｔ自然像进行了研究，得到了其成像条件，并与菲涅尔衍射区的成像条件作了比较。