连体球形金属壳体整体成形实验研究

连体球形金属壳体是一种理想的组合式容器，并可通过组合件的增减来改变容器的总容量.但由于此类容器制造困难，使其广泛应用受到限制.连体球形壳体整体成形技术成果，为此类容器制造提供了一种简便易行的高能成形的新方法.     

石脑油储罐的腐蚀原因及防护对策研究

通过实地调查、测量和综合分析,对茂民石化乙烯工业公司石脑油储罐的腐蚀状况进行综合研究,并对其腐蚀原因提出了全新的防护理念和对策措施,提高了石脑油储罐的使用寿命,获得较好的社会和经济效益。     

复惠斯原理研究

给出了用分布在闭合曲面上的球面子波或复源点，表示三维波传播问题的数学公式。即实惠更斯原理和复惠更斯原理的数学表示。其中实惠更斯原理的数学表示说明惠更斯原理的次级点源假说是可行的，而不必如Ｍｉｌｌｅｒ（１９９１）所认为的，必须以时空偶极子取代点源假说；复惠更斯原理的数学表示则为利用复射线研究复杂初波场在复杂介质中的传播提供了理论依据。     

球坐标系中的复源点方案及其意义

从球坐标的角度考虑,建议一种引入复源点虚坐标的方案,利用这种方案可以实现对非高斯波束场的直接模拟,文中例举了以这种方案对孔径衍射场的复源点仿真。     

试论我国大学智库功能发展的困局——中美比较的视角

智库是以思想成果服务于社会、以价值理性占主导的社会组织。通过对美国智库的初步分析,认为智库最重要的作用是观察社会现象、反思社会问题并提供解决方案。它的生命力取决于它的独立性与思考力。与政府官员相比,它的考量有更多的社会与历史关怀,具有前瞻性;与社会公众相比,它的想法超越琐碎和局部,具有全局感;与高校学者相比,它的研究与探索又有更多的应用意味与政策落点。智库思想独立的关键在于制度设置上的独立性。总的来讲,美国主要智库的制度都至少具备经费独立、组织结构与决策独立、研究成果审核严谨独立三方面的特性。我国智库行业发展刚刚起步,制度尚未健全,大学中的智库亦未能超越,产生高质量的思想成果尚需时日。     

美国大学智库影响力和运行机制研究——以斯坦福大学胡佛研究所为例

胡佛研究所作为隶属于斯坦福大学的大学智库,连续三年位于全球大学智库排行榜的前两位。从斯坦福大学胡佛研究所的影响力和运行机制角度出发,探究胡佛研究所在人员构成、项目管理运作及资金筹集方面的成功因素,指出我国高校智库建设中应注意加强机构的人员分配,结合高校自身的发展构建独具特色的研究目标、拓宽机构的资金渠道以及提高科研成果的水平和形式。     

The BIAS of the maximum likelihood estimators of the von mises-fisher concentration parameters

It is shown that the bias of the maximum likelihood estimators of the concentration parameters of the von Mises and Fisher distributions is considerable. New estimators which are either nearly unbiased or nearly median unbiased are proposed.     

球面径向基函数网络逼近

文章研究球面径向基平移网络的逼近问题．对一类核函数,构造了球面平移网络,证明了该网络在连续函数空间中的稠密性．     

A Geometric Examination of Linear Model Assumptions

From a geometric perspective, linear model theory relies on a single assumption, that (‘corrected’) data vector directions are uniformly distributed in Euclidean space. We use this perspective to explore pictorially the effects of violations of the traditional assumptions (normality, independence and homogeneity of variance) on the Type I error rate. First, for several non‐normal distributions we draw geometric pictures and carry out simulations to show how the effects of non‐normality diminish with increased parent distribution symmetry and continuity, and increased sample size. Second, we explore the effects of dependencies on Type I error rate. Third, we use simulation and geometry to investigate the effect of heterogeneity of variance on Type I error rate. We conclude, in a fresh way, that independence and homogeneity of variance are more important assumptions than normality. The practical implication is that statisticians and authors of statistical computing packages need to pay more attention to the correctness of these assumptions than to normality.     

Underground storage tanks (UST): A closer investigation statistical implications to changing the shape of a UST

ABSTRACT

Gasoline service stations that use underground storage tanks (UST) assume that the manufactured tank is an ideal cylindrical shape. This cross-sectional shape plays a crucial role in determining a functional form for the volume of liquid that remains inside the tank. In industry, these formulas are used to compute strapping charts. But realistically, the manufacture, assembly, and installation of a tank may have deviation from the actual tank design (for which strapping charts had been developed). A theoretical volume function (based on tank dimensions) is used alongside of statistical methodology to reconcile volume differences in gasoline dispensed at the pump meters versus that displaced inside the tank. Statistical inventory reconciliation of this nature falls within the family of leak detection methods approved by the EPA (Environmental Protection Agency) and the California Water Resources Board. This methodology can also be used to assess deformation of the cross-sectional shape of the tank. We consider a deformation to an ellipse. Through simulation, we estimate the tank dimensions based on a nonlinear model with normal errors. The use of normal errors naturally facilitates a likelihood ratio test. Through this exploration, an approximation function is developed to help improve the power of the likelihood ratio test.