Dynamic stiffness vibration analysis using a high‐order beam model

This work presents the derivation of the exact dynamic stiffness matrix for a high‐order beam element. The terms are found directly from the solutions of the differential equations that describe the deformations of the cross‐section according to the high‐order theory, which include cubic variation of the axial displacements over the cross‐section of the beam. The model has six degrees of freedom at the two ends, one transverse displacement and two rotations, and the end forces are a shear force and two end moments. Using the dynamic stiffness matrix exact vibration frequencies for beams with various combinations of boundary conditions are tabulated and compared with results from the Bernoulli–Euler and Timoshenko beam models. Copyright © 2003 John Wiley & Sons, Ltd.     

蜗杆副的跑合工艺

叙述了蜗杆副跑合的目的、作用以及跑合过程的特点和跑合中应重视的几个问题。     

机器人骨骼-肌肉系统工程模拟的动态分析

用振动学理论对仿人机器人骨骼-肌肉系统工程模型进行了分析，并提出了一种控制振动的方法，提高仿人机器人运动精度和缩短达到稳定的时间，同时阐述了这种方法的可行性。     

Many-Body Terms in van der Waals Cohesion Energy of Nanotubes

We have developed a model for the calculation of van der Waals force for layered systems with axial symmetry. Our result can be applied to compute the cohesion of a carbon nanotube to a substrate, the cohesion between nanotubes, and between shells of multiwall nanotubes. We have obtained unusal power laws for the distance dependence of the many-body van der Waals potential.     

Web-based systems design: a study of contemporary practices and an explanatory framework based on “method-in-action”

This paper reports the findings of a detailed study of Web-based systems design (WBSD) practices in Ireland based on data collected over a 3-year period (2002–2005), the objectives of which were to (1) contribute towards a richer understanding of the current “real-world” context of WBSD by characterising the profile of a typical project (team size, timeframe, nature of requirements, etc.) and identifying the key challenges, constraints, and imperatives (i.e. “mediating factors”) faced by Web-based system designers, and (2) understand how those contextual parameters and mediating factors influence the activity of WBSD as regards the selection and enactment of whatever design practices are therefore engaged (i.e. the use of methods, procedures, etc.). Data was gathered through a survey which yielded 165 usable responses, and later through a series of semi-structured qualitative interviews. Using grounded theory, an explanatory conceptual framework is derived, based on an extension of the “method-in-action” model, the application of which to WBSD has not been previously investigated in depth. It is proposed that this framework of WBSD issues is valuable in a number of ways to educators, researchers, practitioners, and method engineers.     

MCRC��ǻ��չ��ճ�̽

本文根据MCRC引进装置的情况,对加拿大Delta公司的MCRC硫回收工艺作了初步探索,介绍了该方法的工艺特征,并评述了引进装置的性能考核结果。文中还结合四川气田建厂的环保要求,评价了MCRC方法的使用价值及意义。     

Multiagent learning using a variable learning rate

Learning to act in a multiagent environment is a difficult problem since the normal definition of an optimal policy no longer applies. The optimal policy at any moment depends on the policies of the other agents. This creates a situation of learning a moving target. Previous learning algorithms have one of two shortcomings depending on their approach. They either converge to a policy that may not be optimal against the specific opponents' policies, or they may not converge at all. In this article we examine this learning problem in the framework of stochastic games. We look at a number of previous learning algorithms showing how they fail at one of the above criteria. We then contribute a new reinforcement learning technique using a variable learning rate to overcome these shortcomings. Specifically, we introduce the WoLF principle, “Win or Learn Fast”, for varying the learning rate. We examine this technique theoretically, proving convergence in self-play on a restricted class of iterated matrix games. We also present empirical results on a variety of more general stochastic games, in situations of self-play and otherwise, demonstrating the wide applicability of this method.     

关于高职院校几点教学改革的思考

高等职业技术教育要求把握好理论教学与实践教学的关系，探索适合培养目标的教学方法，综合运用多种教学方法，十分重视搞好实践教学，适度调整教材结构和测评方法，把教书与育人结合起来。     

Appraisal as a Pervasive Determinant of Anger.

L. Berkowitz and E. Harmon-Jones (see record 2004-15096-001) challenge appraisal theories of emotion by describing 2 sets of conditions (physical discomfort and anger-related muscle actions) in which anger appears to be elicited in the absence of theoretically predicted appraisals. In response, the authors discuss the ability of the specific appraisal model they have developed (e.g., C. A. Smith & L. D. Kirby, 2000, 2001; C. A. Smith & R. S. Lazarus, 1990) to account for such instances of anger. First, a number of issues are clarified relevant to the authors' model, including the nature of both the cognitive operations underlying appraisal and the specific appraisals hypothesized to evoke anger. The authors then describe how their model can account for the instances of anger described by L. Berkowitz and E. Harmon-Jones and how both accounts might be tested. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Constructive Sets in Computable Sets

The original interpretation of the constructive set theory CZF in Martin-Loef‘s type theory uses the‘extensional identity types’.It is generally believed that these‘types’do not belong to type theory.In this paper it will be shown that the interpretation goes through without identity types.This paper will also show that the interpretation can be given in an intensional type theory.This reflects the computational nature of the interpretation.This computational aspect is reinforced by an ω-Set moel of CZF.