非局部损伤模型的客观性研究

为了解非局部模型在模拟应变软化现象时的客观性,文中首先介绍了几种常用的非局部模型,而后针对一个受拉杆问题,采用解析方法研究这些非局部模型能否解决进行应变软化问题数值模拟时存在的两个问题:网格依赖性和零能量消耗问题,得到了杆端位移关于应力、网格尺寸的表达式,并用图解表明这种关系。发现有的模型能够较好地解决这两个问题,而有些模型却不能克服这两个问题,解答也不能客观地反映结构的实际响应。因此有必要进一步深入研究非局部模型。     

An objective finite element approximation of the kinematics of geometrically exact rods and its use in the formulation of an energy–momentum conserving scheme in dynamics

We present in this paper a new finite element formulation of geometrically exact rod models in the three‐dimensional dynamic elastic range. The proposed formulation leads to an objective (or frame‐indifferent under superposed rigid body motions) approximation of the strain measures of the rod involving finite rotations of the director frame, in contrast with some existing formulations. This goal is accomplished through a direct finite element interpolation of the director fields defining the motion of the rod's cross‐section. Furthermore, the proposed framework allows the development of time‐stepping algorithms that preserve the conservation laws of the underlying continuum Hamiltonian system. The conservation laws of linear and angular momenta are inherited by construction, leading to an improved approximation of the rod's dynamics. Several numerical simulations are presented illustrating these properties. Copyright © 2002 John Wiley & Sons, Ltd.     

分类问题中基于信息论度量的客观评价研究

基于信息论度量而系统性地研究了拒识分类中客观评价问题. 定义了客观评价度量为一类无自由参数描述的函数. 该定义是为了从技术上可以简单地判别度量或评价在“客观性”或“主观性”中的归属. 建议了应用并考察24个信息度量. 它们分别来自于互信息、散度、交叉熵的定义. 不同于传统的性能类度量是基于经验公式或用户直觉上的定义, 信息类度量是构建在更为普适的理论基础上. 该类度量可以对二值分类中的“误差类别”与“拒识类别”进行区分, 而不需求人们输入代价信息. 针对拒识分类评价中更为关注的需求, 提出了三个“元度量(meta-measure)”用于考察度量. 由此用户可以在更高知识层面上测评度量的各自优缺点. 应用数值实例比较了24个信息度量. 对其中最优的信息度量进行了在“误差”与“拒识”代价性质方面的解析分析.     

论我国现代化进程中的主客体互动关系

现代化是主体和客体互动的过程 ,它离不开人的精神因素和人的现代化 .本文阐释了精神因素的作用 ,分析了我国现代化进程中精神因素面临的问题 ,说明构建现代精神因素、寻找塑造现代人的途径与对策的重要性、紧迫性 .     

光的轨迹

光在西方传统的写实绘画中是一个重要的造型元素,也是西方写实绘画的一个主要特征.本文追踪光在写实绘画中的历史发展轨迹,分析绘画用光的起源、成熟及其演变,试图探寻其规律,并研究光在绘画中作为视觉语言的审美价值.     

图像分割质量评价的二型模糊集方法

图像分割质量的评价是图像分割技术和算法研究的重要环节,在图像分析和计算机视觉中有着重要应用。依据二型模糊集在不精确性描述方面的独特优势,提出一种图像分割评判指标的二型模糊集表示方法,引入两种二型模糊集的模糊性度量作为图像分割质量的评判标准,构建图像分割质量评价模型。模拟实验验证了该模型的有效性和实用性。     

多模型估计方法应用于人体脉象客观化研究的思考

通过对近年来人体脉象客观化的综合分析,指出目前应用信号处理和智能诊断方法对人体脉象研究的局限性和不足,提出采用多模型估计方法应用于脉象识别,综合反映人体脉象的特征信息,并对关键信息参数进行识别,为中医脉象诊断的客观化提供新方法。     

Faking of a scored life history blank as a function of criterion objectivity.

This study investigated the role of the criterion in determining the transparency of a scoring key. When college students (N = 55) were instructed to fake a life history questionnaire, they were able to do so, but a scoring key empirically derived from a subjective criterion of creativity (ratings) was more transparent than one based upon an objective criterion (patent disclosures). It also appeared that prior exposure to the questionnaire facilitated faking on the former key more than on the latter. Also investigated was the possibility that the difference in transparency was attributable to the subjective key having been biased by a fallacious stereotype. To evaluate this possibility, recruiting interviewers (N = 79) filled out the questionnaire as they thought a creative scientist would. As expected, they selected a greater proportion of the item choices thought to be associated with creativity than of those actually demonstrated to be correlated with creative output. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Personality test scores in the management hierarchy.

Scores on a brief personality test for 457 Ss classified in 5 hierarchical management categories (from I-President, V.P., etc., to V-Clerks and Factory Workers) revealed valid hierarchy trends for the traits (poor) adjustment, emotionality, detail and social dominance, and no valid trends for the traits extraversion, drive and objectivity. The criterion of validity of trend was a single classification analysis of variance of the trait scores for the five hierarchical levels giving an F-ratio significant at the .05 level or better. The independence of these trends of age, education and objectivity was also studied. For all the traits there was a substantial and normally distributed dispersion around the mean at every level of the hierarchy. (PsycINFO Database Record (c) 2010 APA, all rights reserved)