超声心动图评价冠状动脉旁路移植术效果

本文报告我院61例冠脉搭桥手术前、后M型、二维和Doppler超声检查结果对比分析。结果表明:1,心梗并发室壁瘤的患者,因心腔增大及术后室间隔运动方向不正常,M型测定难于准确反映心功能改善状况。2,二维超声心动图能宏观心腔形态,评定心功能全貌。对手术疗效评估较客观。3,超声显示的室壁节段性异常是无创性获得左室壁缺血的最敏感表现。4,局部室壁运动分析与二维测定的心功能数值是一致的。本资料90%的患者术后有改善。

RESEARCH AND IMPLEMENTATION OF A WEB-BASED CAD SYSTEM

Computer aided design on the Internet/Intranet explores new frontiers in design environment. A new Web based CAD system is introduced. The users can install the CAD system on the server to build three dimensional models of products through a Web browser in any operation systems. No system installation and system maintenance are required. A new architecture and the database of system are discussed. The UML models of the system are presented. The proposed organization is implemented on the World Wide Web using Java and CORBA.

AN APPROACH TO FEATURE-BASED PARAMETRIC DESIGN FOR DIE AND MOULD

An approach to feature-based parametric design for die and mould is proposed in this paper.The assembly relationship and parts of the die and mould are described by feature.The dependent relationship of features is described by parent-child operator structure.The feature shape and location can be modified by design parameters.An expert system is used for deriving a geometry of the features which satisfies the given constraints.This approach provides a more natural and convenient method of representing a parametric model of the die and mould.

SOFTWARE SYSTEM FOR SELECTIVE LASER SINTERING

The advent of rapid prototyping & manufacturing techniques represents a major breakthrough in production engineering. This paper is concerned with the software system aspects of the selective laser sintering (SLS),i.e.the issues that deal with an external geometric CAD model to automatically control the physical layering fabrication process as directly as possible ,regardless of the source of the model. The general issues are described and some key methods are given in this paper.

Variant Computer Aided Process Planning System for Rotational Parts

The amount of material must be removed away to produce the final product should minimize, excess stock will increase not only the material cost, but also processing cost, fixture cost, tooling cost, and increases machine cycle times. Noticing in recent years that the world is running out of mineral resources, and the price of engineering materials will continually rise in the future, the percentage of the cost of manufactured part that is due to the cost of materials is also rising. This paper proposed a variant CAPP system for rotational parts based on the concept of group technology, this system accepts part features characteristics code number as an input and provides operation details for manufacturing route with the suitable primary processes required to produce the blank work piece as an output.

A CAD EXPERT SYSTEM OF AIRCRAFT MANUFACTURING COORDINATION

讨论了工程CAD专家系统特点，提出其一般结构。为了解决如飞机制造协调等复杂工程问题，实现一种层次分布式CAD专家系统（HDES）结构。HDES由元级、任务级两个水平的分布式专家系统组成：任务级专家系统（T－ES）主要用于应用设计，它们在其自己的设计领域中执行；元级专家系统（M－ES）则处理合作。介绍了层次－框架－规则的专家系统组织表示方法。

Research and development of a digital design system for hull structures

Methods used for digital ship design were studied and formed the basis of a proposed frame model suitable for ship construction modeling. Based on 3-D modeling software, a digital design system for hull structures was developed. Basic software systems for modeling, modifying, and assembly simulation were developed. The system has good compatibility, and models created by it can be saved in different 3-D file formats, and 2D engineering drawings can be output directly. The model can be modified dynamically, overcoming the necessity of repeated modifications during hull structural design. Through operations such as model construction, intervention inspection, and collision detection, problems can be identified and modified during the hull structural design stage. Technologies for centralized control of the system, database management, and 3-D digital design are integrated into this digital model in the preliminary design stage of shipbuilding.

Research on Design Optimization Strategy in Virtual Product Development

Simulation and optimization are the key points of virtual product development (VPD). Traditional engineering simulation software and optimization methods are inadequate to analyze the optimization problems because of its computational inefficiency. A systematic design optimization strategy by using statistical methods and mathematical optimization technologies is proposed. This method extends the design of experiments (DOE) and the simulation metamodel technologies. Metamodels are built to in place of detailed simulation codes based on effectively DOE, and then be linked to optimization routines for fast analysis, or serve as a bridge for integrating simulation software across different domains. A design optimization of composite material structure is used to demonstrate the newly introduced methodology.

Computer Assisted Designing System for Hands and Formability of Worsted Fabrics

Equations that can predict worsted fabrics’ properties such as bending, shearing, compression, surface and tension, were achieved by means of theoretical and experimental studies. By combining these equations with Kawabata’s hand and silhouette evaluation methods, a software system was established. Then the mechanical properties, hand and silhouette of a fabric can be predicted quickly and accurately in terms of fiber configurations, yarn and fabric structures. The predictive result if unsatisfied can be revised by the function of “Help for designing modification”.

Computer-Aided Detection System on Tangled Roller

The mechanical-touched detector was used commonly in textile production limes. It has some defect with high false alarm rate, response delay and high maintenance cost. In order to overcome such defects, a new kind device was developed and used to detect roller tangled in the production lines. It is based on image processing. The core algorithm was composed of Canny edge detection, removing interference, detection of perpendicularity line and detection of broken tow. After the four steps, the broken tow could be recognized quickly and correctly. The algorithm is robust and high efficiency. So, the detection device has characteristic of stable, quickly-response and low maintains cost. It can keep superiority with long lifespan even in more formidable conditions. It guarantees a safe and stable production condition.

Product-Oriented Integrated CAPP System

The necessi ty of product oriented integrated computer aided process planning (CAPP) is analy zed, and the system architecture and the main functions are described in detail. The key issues of the system, such as the product oriented process planning me thod, the human machine cooperation in process planning, the generation of manu facture bill of material (MBOM) and the dynamic data exchanging technology betwe en CAPP and enterprise resource planning (ERP), are discussed. The CAPP system h as been applied at a CIMS environment corporation successfully.

The Intelligent Teaching Resource Program： Applications to Writing

This paper examined the computer-assisted TRP （Teaching Resource Program）, which is an intelligent writing program. Different from previous research, this study emphasized TRP＇s integrative and holistic functions of intelligent analysis, intelligent scoring, and intelligent comment on writing pieces. In what follows, this paper conducted a study of intelligent essay scoring system related to intelligent analysis, intelligent scoring, and intelligent comment of the writing pieces. Also, this paper provided a literature review of existing computer-assisted essay scoring systems and analyzed the advantages and disadvantages of them. Based on these findings in our research, we can conclude that the integrative and holistic computer-assisted TRP can effectively analyze, score, and comment essays, consequently enhancing the writing performance. Some useful implications from this study include that the computer-assisted TRP should be further integrated with writing learning and instruction

The Design of Gear Parameters Visual System based on LISP

Article use Visual LISP development tools and DCL dialog technology, which implements the standard straight teeth, a two- dimensional cylindrical gear paranaetric drawing on AutoCAD platform, with easy to operate and improve design efficiency. We achieved that using the dialog box design input parameters, and gear parts of the design calculations, parameters proofreading and all kinds of gear design drawing different structures by programming. The output is fully automated computer-aided design system. The results show that the design of the system significantly improves the efficiency of the part design.

Structural Mechanics Analysis Using an FE-Mesh Adaption to Real, 3D Surface Detected Geometry Data

Within today＇s product development process, various FE-simulations （finite element） for the functional validation of the desired characteristics are made to avoid expensive testing with real components. Those simulations are performed with great effort for discretization, use of simulations conditions, like taking different non-linearities （i.e., material behavior, etc.） into account, to create meaningful results. Despite knowing the effects of deformations occurring during the production processes, always the non-deformed design model of a CAD-system （computer aided design） is used for the FE-simulations. It seems rather doubtful that further refinement of simulation methods makes sense, if the real manufactured geometry of the component is not considered for in the simulation. For an efficient exploit of the potential of simulation methods, an approach has been developed which offers a geometry model for simulation based on the existing CAD-model but with integrated production deviations as soon as a first prototype is at hand by adapting the FE-mesh to the real, 3D surface detected geometry.

Computer Aided Design of Geodesic Forms

Geodesic forms constitute an important family of structural systems. They are efficient and appealing and are employed frequently for dome structures. Data generation for geodesic forms has always been a difficult task, from the days of hand data generation using tables of coefficients to today＇s specially written computer programs with many limitations and shortcomings. Formex algebra is a mathematical system which is ideally suited for data generation and configuration processing. The objective of the present paper is to introduce the concepts of formex algebra through which data generation for polyhedric and geodesic forms can be handled with ease and elegance.

On Hybrid Computer-Aided Tools to Interface Design Data

Recognizing the drawbacks of stand-alone computer-aided tools in engineering, several hybrid systems are suggested with varying degree of success. In transforming the design concept to a finished product, in particular, smooth interfacing of the design data is crucial to reduce product cost and time to market. Having a product model that contains the complete product description and computer-aided tools that can understand each other are the primary requirements to achieve the interfacing goal. This article discusses the development methodology of hybrid engineering software systems with particular focus on application of soft computing tools such as genetic algorithms and neural networks. Forms of hybridization options are discussed and the applications are elaborated using two case studies. The forefront aims to develop hybrid systems that combine the strong side of each tool, such as, the learning, pattern recognition and classification power of neural networks with the powerful capacity of genetic algorithms in global search and optimization. While most optimization tasks need a certain form of model, there are many processes in the mechanical engineering field that are difficult to model using conventional modeling techniques. The proposed hybrid system solves such difficult-to-model processes and contributes to the effort of smooth interfacing design data to other downstream processes.

Modeling and Implementing ISO 13584-based Part Library

ISO 13584 (i.e. PLIB) is an international standard for the representation and exchange of CAD part libraries. It aims to provide an application-independent mechanism to enable the share of part library information between applications. In this paper, the approach of modeling part library conforming to ISO 13584 is presented. Also, a prototype of part library management system, i.e. BYL-PLIB, whose implementation is in agreement with ISO 13854 is developed to demonstrate the usefulness of proposed approach.

CAD/CAE system for the ring planetary reducer with small tooth number difference

A CAD/CAE system of the ring-type planetary reducer with small tooth number difference is presented. It is a parameterized CAD/CAE system adopting the object-oriented technique and comprising in itself the geometric feature database (including the modules of ring-plates with inner teeth, eccentric shaft modules and output shaft modules), standard component database and material database. In comparison with design by handwork , this computer aided design and analysis system has the advantages of improved quality, shortened design period and reduced cost. The reliability of the system has been verified by a illustrative example.

USING SYSTEM SIMULATION METHOD AND CAD TECHNIQUE TO SOLVE THE MINING ENGINEERING RELIABILITY IN SURFACE MINES

Subjected to various stochastic factors, surface mining engineering reliability is difficult to solve by using general reliability mathematical method.The concept of reliability measurement is introduced; And the authors have combined system simulation method with CAD technique and developed an interactive color character graphic design system for evaluating and solving the mining engineering reliability in surface mines under the given constraints.

Design and study of computer aided English learning system

Use the Internet for online learning has become one of the directions of the development of education, the traditional classroom learning, the breakthrough time and geographical constraints, more convenient interaction between teachers and students, learning resources are more abundant, more diverse learning styles, has broad application prospects. System uses B / S mode, the application of Java language, together with the MySQL database, high security and good performance.