Arc-length technique for nonlinear finite element analysis

Nonlinear solution of reinforced concrete structures, particularly complete load-deflection response, requires tracing of the equilibrium path and proper treatment of the limit and bifurcation points. In this regard, ordinary solution techniques lead to instability near the limit points and also have problems in case of snap-through and snap-back. Thus they fail to predict the complete load-displacement response. The arc-length method serves the purpose well in principle, Received wide acceptance in finite element analysis, and has been used extensively. However modifications to the basic idea are vital to meet the particular needs of the analysis. This paper reviews some of the recent developments of the method in the last two decades, with particular emphasis on nonlinear finite element analysis of reinforced concrete structures.     

Optimization of block-floating-point realizations for digital controllers with finite-word-length considerations

INTRODUCTIONDuetothefinitewordlength (FWL)effect,acasualcontrollerimplementationmaydegradethedesignedclosed loopperformanceorevendestabilizethedesignedstableclosed loopsys tem ,ifthecontrollerimplementationstructureisnotcarefullychosen .Theeffectsoffinite…     

Finite element simulation of stress intensity factors in elastic-plastic crack growth

INTRODUCTION The finite element method (FEM) has been widely employed for solving linear elastic and elas-tic-plastic fracture problems. The evaluation of stress intensity factors in 2D geometries by FEM is a tech-nique widely used for non-standard crack configura-tions. Basically, there are two groups of estimation methods, those based on field extrapolation near the crack tip (Chan et al., 1970; Shih et al., 1976) and those using the energy release when the crack propagates. However…     

With permission: education policy,space and everyday globalisation in London’s east end

This paper attempts to make sense of a public–private partnership in London’s East End. I am interested in how policy directions, in terms of cultural practices, may operate as links between transnational corporations and education provision, and, additionally, how concepts of space and place provide possibilities for different understandings of educational policy change in local instances. I examine the philanthropic practices of a corporation and the practices of schools receiving this philanthropy, and suggest that these are practices of ‘everyday globalisation’ occurring as part of a specific policy direction, Excellence in Cities.     

Effect of boundary conditions and convection on thermally induced motion of beams subjected to internal heating

Numerical exercises are presented on the thermally induced motion of internally heated beams under various heat transfer and structural boundary conditions. The dynamic displacement and dynamic thermal moment of the beam are analyzed taking into consideration that the temperature gradient is independent as well as dependent on the beam displacement. The effect of length to thickness ratio of the beam on the thermally induced vibration is also investigated. The type of boundary conditions has its influence on the magnitude of dynamic displacement and dynamic thermal moment. A sustained thermally induced motion is observed with progress of time when the temperature gradient being evaluated is dependent on the forced convection generated due to beam motion. A finite element method (FEM) is used to solve the structural equation of motion as well as the heat transfer equation.     

对我国高师教育技术专业本科培养目标的研究

该文运用罗杰考夫曼(Roger Kaufman)提出的组织要素模型(OEM)就教育技术师范专业的本科毕业生的定位问题进行了研究,得出了:要让我们输出的“产品”产生良好的社会效果棗运用教育技术真正实现素质教育的目标,在现阶段高师教育技术专业本科的培养目标可以定位在“培养德、智、体全面发展的、掌握现代教育理论与技术的、具有正确的教育理念的、能将信息技术与小学(初中)学科内容进行整合的、能运用教学设计理论对教学活动进行设计的小学(或初中)教师”。     

基础网作图法——效果图手绘表现实技探究

针对效果图手绘表现市场应用和教学现状上的问题,提出了创建绘图前期空间模式、运用系列版式类型改良绘制条件和方法的"基础网作图法",并介绍了该作图法的具体实施手段和步骤,使效果图的手绘表现和教学更具实效性和可操作性。     

用于人体中心无线网络的平面倒F天线仿真

仿真了用于构建人体中心无线网络的蓝牙通信系统平面倒F天线.依据天线理论和人体中心无线网络的特定需求,选择工作于蓝牙频段的平面倒F天线为仿真对象.通过对电磁场EDA仿真软件的整体了解,选择美国REMCOM公司的全波三维电磁仿真软件XFDTD作为仿真平台.仿真结果为,在2.45 GHz的中心频率下,电压驻波比1.31,输入阻抗50.4-j13.3Ω,频带宽度130 MHz,相对带宽5.3%,天线系统效率79.94%.该性能优良的窄带天线,可满足人体中心无线网络的通信需求.     

数学标记语言MathML

随着网络技术的发展,各个科研领域之间的信息交流日趋频繁,针对数学公式在Web上的应用,W3C组织提出了一种基于XML的数学标记语言(简称MathML)。该文通过简要介绍MathML的发展状况、语法结构以及相关的工具软件,为数学公式在Web上的应用提供了一种全新的解决方案。     

椭圆曲线密码体制中有限域算法的分析

密码技术是信息安全的关键技术，密码算法又是密码技术的核心。谈文简单介绍了公开密码密钥体制，并给出了ECC的优点。但椭圆曲线密码体制中有限域上的运算速度极大地影响它的实现速度。本文通过论述椭圆曲线密码体制中有限域理论，分析了素域、二进制有限域中加法、采法的实现算法，并给出了利于硬件实现的算法。