二维任意形状寄生电阻电容的边界元计算

由于集成电路技术高速发展,精确提取任意形状寄生电阻电容变得十分重要,本文以直接边界元素法为基础,利用圆弧样条插值近似任意曲线边界,使插值曲线具有整体一阶连续性,并克服了大挠度与多值的困扰。在直线边界使用线性连续元,在曲线边界使用二次连续无。对两邻国为直线的角点,我们曾提出处理角点处存在多重法的导数的一种方法。这里,它被推广到角点邻边含曲线段的情形。数值结果表明模拟器是可行的。     

Crashworthiness design of vehicle by using multiobjective robust optimization

Although deterministic optimization has to a considerable extent been successfully applied in various crashworthiness designs to improve passenger safety and reduce vehicle cost, the design could become less meaningful or even unacceptable when considering the perturbations of design variables and noises of system parameters. To overcome this drawback, we present a multiobjective robust optimization methodology to address the effects of parametric uncertainties on multiple crashworthiness criteria, where several different sigma criteria are adopted to measure the variations. As an example, a full front impact of vehicle is considered with increase in energy absorption and reduction of structural weight as the design objectives, and peak deceleration as the constraint. A multiobjective particle swarm optimization is applied to generate robust Pareto solution, which no longer requires formulating a single cost function by using weighting factors or other means. From the example, a clear compromise between the Pareto deterministic and robust designs can be observed. The results demonstrate the advantages of using multiobjective robust optimization, with not only the increase in the energy absorption and decrease in structural weight from a baseline design, but also a significant improvement in the robustness of optimum.     

网络状态感知的标识映射系统研究

可扩展性是当今路由系统面临的最主要的问题之一;学术界一致认为位置与标识分离的思想是解决路由可扩展性问题的最有效的方法;然而,在位置与标识分离的网络中,如何设计一个高效的映射服务系统仍是一个难题;文中提出了影响映射服务系统性能的三个主要因素,并基于对这三个主要因素的分析,提出了一个网络状态感知的标识映射系统NAMS; NAMS包含两个关键元素:网络感知Agent和服务节点;我们认为,NAMS是解决高效映射服务系统设计实现问题的有效途径.     

基于ARM9和FAT的高速海量数据采集系统

针对一些控制系统,为了能够快速获取实时数据,并借助上位机系统进行离线分析,提出了移植FAT文件系统到ARM中,将实时采集的海量数据保存到SD卡的设计方案;该方案以S3C2440 ARM9为嵌入式平台,结合文件系统和SD卡存储技术设计了数据采集系统,应用MATLAB等软件对数据进行分析处理,实现了对控制系统模型的矫正;经飞思卡尔智能车系统的设计证明,这种方案在系统建模和系统特性分析上具有较强的应用价值.     

Excel中公式和函数教学的研究与探讨

公式和函数是Excel教学中的重点与难点,电子表格中的数据运算正是通过公式和函数完成的,只有掌握了它们的使用,才能在日常的Excel使用中提高工作效率。该文介绍了Excel中公式和函数教学中的一些方法与体会。     

MCLA教学法在教学实践中的应用

MCLA是一种基于任务的学习方法,它是学生在教师的引导下,培养独立解决实际问题能力,侧重培养实际应用技能的一种新型教学模式.该文探讨了MCLA的教学方法及其实施的关键环节,阐述了这种教学法的特点,并以浙江丽水广播电视大学成人脱产班为例讲述了使用MCLA方法进行的实践教学改革.     

在网格虚拟组织中构建远程教育系统模型

网格技术已经成为当前国际计算机技术研究的热点和前沿领域,它代表了继Internet技术和Web技术之后的第三次技术浪潮。随着其不断发展完善,必然会推动远程教育的发展。该文以网格基础理论为基石,以远程教学平台为研究对象,论述了基于网格技术的远程教育系统模型构成及其工作过程,从而达到共享各种异构教学资源、整合各种教学服务的目的。     

硬盘数据恢复技术与应用

计算机及网络应用过程中,由于各种原因造成存储数据丢失或损坏经常发生,这会给用户带来很多困扰。因此,研究数据恢复技术是十分必要的。本文简明扼要的对硬盘存储原理、数据恢复实现过程、常用数据恢复软件和技巧做了介绍。     

基于ZigBee无线传输技术的电子听诊器

设计一种基于ZigBee无线传输技术的实用电子听诊器,能够采集和处理人体心音数据,并将处理后的数据通过无线传输方式发送出去,接收端通过USB通信接口将数据传输到上位机进行实时显示.该设计运用MEMS麦克风采集心音信号,前置放大和滤波端提供信号放大和滤波等调理功能.无线传输模块采用TI公司的集成无线收发芯片CC2530.     

Computational investigation of interactions between human H2 receptor and its agonists

Type 2 histamine receptor (H(2)R) is widely distributed in the body. Its main function is modulating the secretion of gastric acid. Most gastric acid-related diseases are closely associated with it. In this study, a combination of pharmacophore modeling, homology modeling, molecular docking and molecular dynamics methods were performed on human H(2)R and its agonists to investigate interaction details between them. At first, a pharmacophore model of H(2)R agonists was developed, which was then validated by QSAR and database searching. Afterwards, a model of the H(2)R was built utilizing homology modeling method. Then, a reference agonist was docked into the receptor model by induced fit docking. The 'induced' model can dramatically improve the recovery ratio from 46.8% to 69.5% among top 10% of the ranked database in the simulated virtual screening. The pharmocophore model and the receptor model matched very well each other, which provided valuable information for future studies. Asp98, Asp186 and Tyr190 played key roles in the binding of H(2)R agonists, and direct interactions were observed between the three residues and agonists. Residue Tyr250 could also form a hydrogen bond with H(2)R agonists. These findings would be very useful for the discovery of novel and potent H(2)R agonists.