A design method and its CAD prototype system for surface micromachined MEMS devices

Microsystem Technologies - Now the MEMS design method of “bottom–up” (mask-to-shape-to-function) has been adopted widely. However, it is complicated, time-consuming and not...     

CAD tools for aesthetic engineering

The role of computers and of computer-aided design tools for the creation of geometrical shapes that will be judged primarily by aesthetic considerations is reviewed. Examples are the procedural generation of abstract geometrical sculpture or the shape optimization of constrained curves and surfaces with some global ‘cost’ functional. Different possibilities for such ‘beauty functionals’ are discussed. Moreover, rapid prototyping tools based on layered manufacturing now add a new dimension to the visualization of emerging designs. Finally, true interactivity of the CAD tools allows a more effective exploration of larger parts of the design space and can thereby result in an actual amplification of the creative process.     

Adding agility to CAD: Integrating product data management tools into an organization

The integration of product data management (PDM) software tools into a manufacturing company requires both technical and organizational considerations. Using an information processing paradigm, the impact of PDM on the design process and group activities are assessed. Using ongoing work with the furniture industry in the Southeastern United States as an example, the relationship of job design and the product development process to the introduction of PDM is examined. © 1997 John Wiley & Sons, Inc.. Inc.     

Impact of CAD tools on creative problem solving in engineering design

This paper presents the results of a survey of CAD users that examined the ways in which their computational environment may influence their ability to design creatively. This extensive online survey builds upon the findings of an earlier observational case study of the use of computer tools by a small engineering team. The case study was conducted during the conceptual and detailed stages of the design of a first-to-world product. Four mechanisms by which CAD tools may influence the creative problem solving process were investigated: enhanced visualisation and communication, circumscribed thinking, premature design fixation and bounded ideation. The prevalence of these mechanisms was examined via a series of questions that probed the user’s mode of working, attitudes, and responses to hypothetical situations. The survey showed good support for the first three mechanisms and moderate support for the fourth. The results have important implications for both the users and designers of CAD tools.     

面向装配的CAD技术研究

面向装配的设计DFA(Design for Assembly）是并行工程的一个有效工具。本文系统阐述了DFA的发展 、意义及其与传统的考虑装配工艺性的区别;介绍DFA的主要内容和几个典型的DFA分析方法,重点分析Boothroyd-Dewhurst方法和步骤;叙述集成CAD技术的DFA应解决的问题及典型的DFA分析软件;最后总结了DFA的研究特点。     

Integrating language and database for CAD applications

This paper focuses on some issues related to the integration of databases and programming language concepts and the usefulness of this integration for integrity maintenance. The first section explains why compilation should be independent of the database and presents some consequences of this independence. The second section shows how procedures become integral parts of the database and serve to implement automatic maintenance of designer-defined integrity by being automatically invoked upon database operations. The third section develops a particular scheme for integrity maintenance with these procedures. Finally, in the fourth section, semantic integrity is extended to system integrity and it is suggested that the scheme developed in the third section can apply to system integrity.     

Integrating VR and CAD

Suppliers of advanced computer-aided design and engineering applications (CAD/CAE) intend to make interactive, immersive visualization an integral part of their product offerings. Adding virtual reality (VR) capability helps reduce users' design-cycle time and cut costs. Advances in computing power and 3D visualization functionality enable this logical evolution of technology. While many VR companies have established procedures for importing data from CAD applications into VR applications, Dassault Systemes takes a different approach to integrating CAD with VR. Through collaboration with Fakespace, the company is developing native support for immersive visualization display devices within its Catia Version 5 applications. The paper discusses the functionality required to enable immersive visualization and hands-on interactivity within CAD applications. It also describes the joint development effort to bring this functionality into Catia     

CAD of ECM tools

The last two decades have witnessed a rapid development in the application of electrochemical machining (ECM) techniques in production industries. However, there are tool design problems which hinder its application. Available analytical methods for the design of ECM tools do not yield satisfactory results.

In this paper, the finite-element technique is used which has proved superior to all other techniques. Also, details are given of the method employed for the computation of metal removal and gap in ECM. Relevant computer programs are included.     

Integrating techniques and tools for testing automation

This article presents two tools to generate test cases, one for Java programs and one for .NET programs, as well as a structured testing process whereby such tools can be used in order to help in process automation. The main innovation in this work is the joint use of diverse techniques and technologies, which have been separately applied to test automation: reflection to extract the class structure; regular expressions to describe test templates and test cases; JUnit and NUnit as test case execution frameworks; mutation and MuJava as test case quality measurers; serialization to deal with the parameters of complex data types; and once more, reflection, to facilitate the test engineer in the task of writing the oracle. Finally, the article presents an experiment carried out to validate the work. Copyright © 2006 John Wiley & Sons, Ltd.     

CAD tools for bridging microsystems and foundries

To move microsystems from research prototypes to an industrial market, CMP, the French multiproject wafer service, has adapted an existing commercial tool to the automated design of micromachined devices     

An object-oriented program shell for integrating CAD software tools

The number of CAD programs and their capabilities have risen greatly in recent times. As well, the number of Application Programmer Interface (API) products and the number of representation standards for display, database storage and communication has also risen. These applications, API products and representation standards are generally not compatible except through specific, individually programmed interfaces. Incompatibility of API software products arises because of: (i) different representations for the same information, and (ii) different ways of communicating with the API products. This article describes the derivation of a generic software architecture to overcome the second source of incompatibility. The derivation employs the “box structure” (system engineering) software development methodology in a generic, high level manner; by considering activities performed with current CAD software, but without going into the details. The objective is to determine the types of software objects required and the types of messages that must be passed between them. The result is an architecture in which Tool objects embodying individual software tools are plugged into a Shell object which holds the Tool’s together as a single program, provides for interactions between Tool’s and controls when each Tool is active. In this way separately developed software tools can be combined seamlessly into a highly graphical and interactive environment.     

CAD智能工程数据库集成系统

从设计过程入手,通过对共性工程数据及其关系的讨论,基于C/S结构的分布式计算,引入知识工程,建立知识库,应用推理机制,提出了一种CAD技术集成方案和系统实现原型,通过开发方便的操作工具,使得共性工程数据库中的数据的使用和管理具有智能化,方便设计人员使用和提高设计效率。     

An efficient DIPIE algorithm for CAD of electrostatically actuated MEMS devices

Pull-in parameters are important properties of electrostatic actuators. Efficient and accurate analysis tools that can capture these parameters for different design geometries, are therefore essential. Current simulation tools approach the pull-in state by iteratively adjusting the voltage applied across the actuator electrodes. The convergence rate of this scheme gradually deteriorates as the pull-in state is approached. Moreover, the convergence is inconsistent and requires many mesh and accuracy refinements to assure reliable predictions. As a result, the design procedure of electrostatically actuated MEMS devices can be time-consuming. In this paper a novel Displacement Iteration Pull-In Extraction (DIPIE) scheme is presented. The DIPIE scheme is shown to converge consistently and far more rapidly than the Voltage Iterations (VI) scheme (>100 times faster!). The DIPIE scheme requires separate mechanical and electrostatic field solvers. Therefore, it can be easily implemented in existing MOEMS CAD packages. Moreover, using the DIPIE scheme, the pull-in parameters extraction can be performed in a fully automated mode, and no user input for search bounds is required.     

MEMS降阶宏模型仿真平台研究

随着MEMS系统级设计成为研究的热点,MEMS系统级CAD的开发日益重要.论文介绍了一种基于降阶宏模型MEMS系统级仿真平台,通过有限元方法提取MEMS器件几何物理数据.建立MEMS器件有限元模型.利用Krylov子空间算法缩聚自由度建立宏模型,通过系统级仿真平台对此进行系统级仿真. 整个流程通过VC++编译器调用ANSYS、嵌入封装的算法动态链接库、集成SIMULINK系统仿真器完成.并用双端固支梁实例对所有模块加以验证,仿真结果准确,计算效率较高.     

Integrating computer-mediated tools into the language curriculum

Abstract The study reported in this paper investigated second-year junior college students' attitudes and perceptions towards the web as an educational resource. The students in southern Taiwan were given an introduction to Internet use for research projects. Study data was collected using surveys and observation. Factor analysis was employed to identify six areas for further t -test analysis: cognitive disorientation, learning anxiety, perceived enhancement of language ability, perceived enhancement of cultural under-standing, the web considered as a useful search tool and the overall perception of language learning on the web. The study showed that computer networks have the potential to empower students when they are implemented appropriately. Some pedagogical suggestions are made for the effective use of computer networking for second and foreign language learning.     

Integrating program analyses with programmer productivity tools

Because software continues to grow in size and complexity, programmers increasingly rely on productivity tools to understand, debug, and modify their programs. These tools typically use program analyses to produce information for the programmer. This is problematic because it is based on the assumption that the programmer and program analyses all use the same vocabulary. If the programmer and analyses did not use the same vocabulary then the results of the analyses will be meaningless to the programmer. For example, ‘v124 may be NULL’ does not mean much to the programmer but ‘myStack may be NULL’ is meaningful. Often, the programmer and analyses prefer different vocabularies. While the programmer prefers his programs' source code, an analysis will prefer a simplified representation. Unfortunately, writing an analysis that works on the source code is difficult because the analysis must deal with the idiosyncracies of the source language (e.g. nested classes). In comparison, writing an analysis on SSA form is easy but the output of the analysis is not meaningful to the programmer; it must somehow be translated into something the programmer understands. We present a system, RTalk, that makes it easy to support both the programmers' and the analysis' needs. RTalk generates a translator between the programmers' and the analysis' vocabulary. Thus both the programmer and the analysis can use the vocabulary most natural to them. We demonstrate the effectiveness of RTalk by describing program understanding and program optimization tools that we have already built using RTalk. Copyright © 2011 John Wiley & Sons, Ltd.