Computer aided structural analysis

A tutorial survey directed to the practicing engineer who is interested in computerized techniques for static and dynamic structural analysis.The discussion is directed to the general questions which occur in the application of computer aided analysis. Consideration is given to structural modeling, input preparation procedures, solutions algorithms, numerical errors, and output interpretation. The emphasis is on large general purpose programs and on establishing a definition of the current state of the art.     

Computer aided instruction in the skills of linguistic analysis

Students on the B.A. (honours) in Communication Studies at Sheffield City Polytechnic study linguistics as part of their degree. These students seem to vary considerably in their abilities to analyse sentences. The difficulties that they experience seem to be the same for each successive intake even though the difficulties may not be shared by many students in any particular year. Thus, the teacher of linguistic analysis often needs to resort to individual student tuition to deal with the same problems year after year. The computer aided instruction program described in this paper seeks to overcome these problems. It enables students to progress at their own rate through a series of exercises designed to instruct them in immediate constituent analysis. The program was found to be very successful in achieving its linguistic objectives and also in producing a remarkably high degree of interest in computers.     

Computer aided analysis of field distribution: rectangular geometries

An explosive seeding technique for the solution of field equations has been developed and applied to an investigation of the electrical behaviour of integrated-circuit Hall plates. Output formats have been sought which allow rapid and efficient computer-aided design. The effects of electrode size and position, plate aspect ratio and magnetic field strength have been studied and criteria for design considered.     

Computer diagnosis system for thermal analysis by BEM aided with simple CAD

With the aid of the supercomputer we have performed three-dimensional simulations in practical cpu time. At the same time, though, huge amounts of output data must be treated automatically by post processors, so that only necessary information will be extracted and changes of models, mesh subdivisions, or boundary conditions will be taken into account. This type of information processing cannot be attained by conventional postprocessors, and a new concept of postprocessing and system must be developed in the sense of computer-aided engineering or computer diagnosis. We present a computer tomographic system COMTOS-BEM based on three-dimensional boundary element analysis; it houses its own geometric modeling and automatic mesh generation. Furthermore, it supports design feedback reactions to change modeling or meshing, make recalculations, and renew boundary conditions. In this paper, we state the basic concept of the proposed computer diagnosis system and present the necessary geometric modeling and processing and boundary element formulations. Some numerical examples illustrate the validity and effectiveness of our system in practice.     

Computer aided laboratory instruction

In order to give students a basic introduction to real-time applications in physics the Computer Aided Instruction Laboratory was set up at the Universität Karlsruhe. This paper describes the computer system installed and some of the on-line experiments connected.     

Computer aided reliability for optimum maintenance planning

Computer aided Maintenance planning for mechanical equipment is presented in this work to implement the optimized extensive maintenance plan at a specific time horizon. The objective is to interchange the unscheduled corrective maintenance into scheduled preventive maintenance depending on historical data of equipment. This work is concerned with development of reliability analysis based on Weibull distribution. An optimization technique has been developed to provide the optimized preventive maintenance plan for the whole equipment during a required time horizon.     

Computer aided part manufacturing

The decisions made by manufacturing engineers have to be flavoured by the value system of the times. The rapid change in value systems caused by the human/environmental revolution, will bring about the beginning of a new epoch in manufacturing. This will make old ways of doing things obsolete, but also create new possibilities. Therefore, manufacturing industry may change to a new pattern better adapted to the new environments.In order to meet this challenge in the Norweigan society, an industrial concept, a cell concept, has been developed by the Production Engineering Laboratory NTH-SINTEF. Vital parts of the cell concept have been tested in a full scale pilot plant, in which a variety of diesel engine parts are machined.Part programming, machine loading and scheduling in the cell together with the cell control functions, are performed computer aided, using a three level computer hierarchy.     

Computer aided setup planning for machining processes

This paper deals with an automatic setup planning system for machining processes of prismatic parts. The proposed system concurrently implements both machining sequences of reference surfaces and machining sequences of features for the purpose of minimizing number of setups in setup planning. Experienced planners' knowledge are represented as rules and used for machining sequences of reference surfaces and they are implemented by using EXSYS. A case study is performed to evaluate the performance of the proposed system.     

Computer graphics aided geometric modeling and mesh generation schemes for preprocessing and finite element analysis

The paper describes automated generation and editing schemes together with the development of computer-aided geometric models for general applications. For the construction of general finite element models of complex shapes, conventional approaches typical of wireframe, surface, or solid modeling cannot be effectively utilized for generating continuum solid models as well as discrete models simultaneously. In view of these facts, features to generate and model two-dimensional as well as threedimensional continuum and discrete models by isoparametric mapping/solid geometrical modeling techniques via a common interactive processor are described. The proposed scheme is demonstrated for modeling structural, thermal, or flow networks that are commonly encountered in engineering applications. In a research environment, the techniques addressed in this paper should prove to be very useful in providing flexibility and thereby significantly reducing the work load of frequent CAD users.     

Computer aided model building and CAL

Model building has become an educational objective at the tertiary and the secondary level. There are reservations in regard to the suitability of computer simulations for integrating modelling into the education process. Interactive simulation systems can be designed to meet educational requirements, presenting a preprogrammed simulation environment which only has to be supplied with the model itself. The model can be supplied as a set of statements (“missinglink” program) or as a block diagram representing the structure of the system. Examples are presented for both possibilities and their respective characteristics are discussed.     

Computer aided optimal plastic design

An interactive method for optimal plastic design of structures that obey the square yield criterion is presented. Sections of fixed dimensions such as standard sections can be used for design and realistic cost estimates can be used in assessment. The design is developed interactively by upgrading in steps, using the rate of increase of strength per unit incremental cost as a guide. The entire method is explained by establishing the physical meaning of the expressions derived. The method is suitable for implementation in microcomputers.     

Computer aided EDM electrode design

A large number of EDM electrodes are used in die and mold manufacturing. However, the electrode design is very time consuming. This paper introduces a computer-aided electrode design system for die and mold manufacturing. Using this system, when the electrode boundaries are selected, the electrode tool, its holder, and a work coordinate system are created automatically. An algorithm of sharp corner uncut detection for electrode design is also developed. With this algorithm, sharp corner uncut can be detected by calculating the surface angles at their common edges. The system has been tested and proved to be able to shorten the electrode design lead-time significantly.     

Computer aided process planning for tape automated bonding

This paper describes the design and development of a knowledge based Computer Aided Process Planning (CAPP) system for Printed Circuit Board assembly. The domain considered uses both Surface Mount Technology (SMT) and Tape Automated Bonding (TAB) components. The structure and design of the CAPP system, and its inputs and outputs are discussed.     

计算机辅助诊断算法平台

针对计算机辅助诊断系统已成为制约医疗器械硬件发展的关键因素,提出一个医学影像辅助诊断算法平台（Computer Aided Diagnosis Algorithm Platform,CADAP）,帮助研发人员高效、便捷地开发面向人体多种疾病的计算机辅助诊断系统．平台集成医学影像三维可视化、图像增强、图像分割、ROI（Regionof Interest）检测、特征提取与分类等关键算法,并引入工作流技术,采用组件与多层体系结构建立一个算法流程可以动态管理和复用的算法平台．     

Current-mode subthreshold MOS circuits for analog VLSI neuralsystems

An overview of the current-mode approach for designing analog VLSI neural systems in subthreshold CMOS technology is presented. Emphasis is given to design techniques at the device level using the current-controlled current conveyor and the translinear principle. Circuits for associative memory and silicon retina systems are used as examples. The design methodology and how it relates to actual biological microcircuits are discussed.