CAD System For Design Research Articles

M-Smart-An Improved Multi-Style Engineering Design CAD System for Clothing Thermal Functions

M-Smart-An Improved Multi-Style Engineering Design CAD System for Clothing Thermal Functions

Development and Application of CAD/CAE Technology in China Coal Mine Machinery Equipment

This paper briefly reviews the development and application process of the CAD/CAE technology in China coal mine machinery equipment, it is the process of from 2-D drafting to 3-D modeling, from Down-Top the building blocks design to Top-Down the really design process, from the geometry structure to comprehensive properties design; Then it introduces the CAD/CAE application status in the three aspects of interactive conventional design, secondary development professional software and virtual prototyping technology; And it also analyzes the development and application trend in constructing the based project database, building the development platform for dedicated equipments design, and using the collaborative design CAD system

Simulation of the weave structural design of synthetic woven fabrics

This study surveys the basic procedure of data base system of the fabric structural design which can be linked with existing pattern design and garment design CAD systems. For this purpose, the theoretical and empirical equations related to the fabric structural design are analyzed and discussed with various fabric specimens. The fabric structural parameters such as weave density coefficient, cover factor and yarn density coefficient of various kinds of fabrics are calculated using the empirical equations. These calculated fabric structural parameters of many kinds of polyester and nylon fabrics are compared and discussed with weave pattern, and materials such as polyester and nylon. Furthermore the difference between fabric structural parameters calculated by empirical equations are analyzed with polyester and nylon fabrics as a basic study for data base system of the fabric structural design. Finally, the weave density coefficients of polyester and nylon fabrics were analysed and discussed with shrinkages of dyeing and finishing processes, and also surveyed according to the weaving company and weave structural parameters such as weave pattern and denier.

니트 캐드 프로그램을 활용한 니트디자인 프로세스 적용 방안

The knitwear industry requires ways to satisfy a changing environment. This study suggests a knitwear design process using a knit CAD program. Such a process needs to implement a CAD system that develops a sufficient knit design system to advance the knitwear industry in both planning and manufacturing. In order to contextualize this research, this study reviewed the current state and problems of the knitwear industry and the market, and investigated the actual condition in which the CAD system is used in knit design by CAD system service providers. The findings of the study are as follows: First, All brands had individual ways to reduce the amount of lead-time. The knit designers pointed out that any given sample product is made in the form of a swatch; after the knitting step and prior to the manufacturing process. In women's wear brands, basting was inserted into the production process in order to reduce the amount of sample losses. Second, a CAD program enables the uses of swatches to see the adequacy of yams, textures, and style that simulate the completed style. Third, this study examined the efficiency of knit design process conducted by the knit design CAD system based on expert assessments, showing that the use of a knit CAD program in commercial knit design proved to be more efficient than in previous models.

A hybrid case-based reasoning CAD system for injection mould design

Injection mould design generally lies on the critical path of a new product development. The design efficiency will have significant impact on the overall lead time of a new product. This paper presents a prototype injection mould-design system using a hybrid case-based reasoning (HCBR) approach. Case-based reasoning (CBR) is a solving paradigm that uses previous episodes on solving problems similar to the problem at hand (the new problem) as the basis for solving the new problem. In this hybrid system, CBR is incorporated with generalized design knowledge, and provides a flexible and comprehensive model of design. The knowledge base of the system would be accessed by mould designers through interactive programs so that their own intelligence and experience could also be incorporated with the total mould design. The approach provides a workable model of mould design system with CBR and knowledge-based expert system intelligent support, which could suggest good and proven design solutions to new design problems quickly, avoiding the time necessary to create those designs from scratch, for the plastic products manufacturing industry.

A CAD system for multi-style thermal functional design of clothing

Designing clothing with good thermal functional performance is very demanding and time-consuming if we follow traditional design methods. An innovative method consisting of a CAD system, allowing the designer to perform multi-style clothing thermal functional design on a customized virtual human body, is presented in this paper. The new functionalities of the virtual system provide the abilities to perform intelligent design of different clothing styles and materials for different body parts according to individual design requirements, namely design of various categories of clothing, such as hat, coat, trousers, gloves and shoes in the same design scheme. The designed clothing can be worn on a virtual human body and set in various wearing scenarios. The thermal behaviors in the human body-clothing-environment are simulated to predict the thermal performance of clothing and thermal response of the human body at multi-parts. 2D/3D visualization and animation of the simulation results are presented to help the designers to preview and determine whether the thermal performance of clothing is satisfactory and then obtain feedback to improve their designs iteratively.

Towards the design of intelligent CAD systems: An ontological approach

Although many sophisticated CAD integrated environments have been developed and are currently adopted by enterprises in the design of mechanical parts and components, such kinds of tools should be extended in order to reach higher levels of performance. To this aim, Artificial Intelligence techniques are particularly suitable to provide CAD tools with a sort of “intelligence” typical of human experts. In particular a complex mechanical object to be designed exploiting CAD systems can be considered as an aggregation of simpler components that have to be put together in order to satisfy precise design rules owned by expert designers core knowledge. This paper presents an ontological approach to the problem of representing relationships among step-by-step more complex parts, in order to obtain a final product that fully meets initial requirements.

Quasi-Aesthetic Curves in Rational Cubic Bézier Forms

AbstractDesigning aesthetically appealing models is vital for the marketing success of industrial products. In this paper, we propose quasi-Aesthetic Curves that can be used in CAD systems for aesthetic shape design. Quasi-Aesthetic Curves represented in rational cubic Bezier Forms are curves whose logarithmic curvature histograms (LCHs) become nearly straight lines. The monotonicity of curvature of quasi-Aesthetic Curves is checked by the proposed method. We generate quasi-Aesthetic Curves by approximating the Aesthetic Curves whose LCHs are strictly represented by straight lines. We show that one Aesthetic Curve segment whose change of tangential angle is less than 90 deg. can be replaced by one quasi-Aesthetic Curve segment guaranteeing the monotonicity of the curvature in most of practical situations.

Preliminary Data-Base System for the Fabric Structural Design

This topic surveys the basic procedure of data base system of the fabric structural design which can be linked with existing pattern design and garment design CAD systems. For this purpose, the theoretical and empirical equations related to the fabric structural design are analyzed and discussed. The fabric structural parameters such as weave density coefficient, cover factor and yarn density coefficient of various kinds of fabrics are calculated using the empirical equations. These calculated fabric structural parameters of many kinds of polyester, nylon, worsted and cotton fabrics are compared and discussed with weave pattern, weaving loom and materials according to weaving manufacturer. Furthermore the difference between fabric structural parameters calculated by empirical equations are analyzed with polyester, nylon, worsted and cotton fabrics, and these structural parameters are analyzed and discussed with weave and finishing shrinkages. Finally, the case study of the data base system for fabric structural design is presented with weave pattern, weaving loom and weaving manufacturer, and also presented with the application fields to the existing woven fabric and clothing CAD systems.

Computerized analysis of tissue density effect on missed cancer detection in digital mammography

This paper presents a study of the analysis of breast density in missed cancer cases and the effect of tissue density on caner detection. A total of 100 missed cancer cases were collected. The breast density tissue was segmented with a statistical-based method. A set of tests was then applied to examine: (1) the differences in density between the mammograms at the detected stage and that at missed stage; (2) the density difference between the cancerous mammograms and their contra-lateral normal mammograms in the missed cancer cases; (3) the effect of breast density on CAD cancer detection. The results demonstrate that breast density is an important factor affecting not only radiologist's reading but also CAD performance. In order to improve early detection of breast cancer, a special effort should be directed to the high dense breast cases in CAD system design.

WE‐C‐330D‐02: Image Science and CAD: In Pursuit of a Fundamental Theoretical Basis for CAD Development

Computer‐aided diagnosis is still a very immature field, with very little theoretical framework upon which it is based. This is a major limitation in both developing systems and in evaluating them in a meaningful way. It is clear that in the future CAD will play a greater role in radiology, both as secondary reader and as a primary reader. The current clinical implementation of CAD is as second reader to radiologists. This will shift to CAD being used by a physician assistant and CAD as the primary reader and the radiologist as the secondary reader. Ultimately, CAD will be the only reader, at least for a subset of cases.However, to increase the development and adoption of new CAD systems, the field needs a better fundamental foundation. This foundation will come from several areas. First, as we gain a better understanding of human observers, we can use this information not only to develop more accurate CAD algorithms, but also importantly, to design CAD systems that can be integrated into the radiologists' workflow more fully. Second, models of CAD techniques need to be developed. In analogy to modeling ideal observers and human observers, much can be gained from modeling CAD schemes. Third, a thorough understanding of the interaction between the image and the CAD technique is needed. For example, if the shape of the NEQ curve of the image receptor changes, can we predict how the performance of the CAD technique will change.Medical imaging technology is rapidly changing. The current paradigm for developing CAD systems — try different techniques on hundreds of images — cannot keep pace with these changes, especially as new imaging systems are developed, where clinical images are scarce. Our goal should be to develop the field to the stage where it will be possible to model the imaging system's characteristics and then, guided by models of human observer performance, select from an array of image processing, artificial intelligence and pattern recognition techniques a group of techniques that will produce the optimum CAD system.This talk will present my vision for the future of CAD and what is necessary for the field to make rapid progress.Educational Objectives:1. Discuss future roles of CAD as both a secondary and the primary reader.2. Explain the fundamental limitations of CAD development.3. Discuss one possible approach to overcoming the limitations in the future.

CAD System for Human-Centered Design

Computer-Aided Design and Applications is an international journal on the applications of CAD and CAM. It publishes papers in the general domain of CAD plus in emerging fields like bio-CAD, nano-CAD, soft-CAD, garment-CAD, PLM, PDM, CAD data mining, CAD and the internet, CAD education, genetic algorithms and CAD engines. The journal is aimed at all developers and users of CAD technology to ptovide CAD solutions for various stages of design and manufacturing. The journal publishes all about Computer-Aided Design and Computer-Aided technologies.

A Broad-Band Lumped Element Analytic Model Incorporating Skin Effect and Substrate Loss for Inductors and Inductor Like Components for Silicon Technology Performance Assessment and RFIC Design

We present a broad-band lumped element planar inductor model that is suitable for RFIC design in silicon technologies. We provide extensions of the modeling methodology to similar components such as differential inductors, baluns, and solenoid inductors. The analytic computation of the physics-based model components, incorporating both metal skin effect and substrate loss, is described. The model is validated using measured data from over 200 inductors made with five different silicon back-end process technologies. The physics-based implementation of the model allows its use for determining the optimum process technology characteristics for specific radio frequency integrated circuit (RFIC) designs. The analytical based implementation with lumped elements enables effective integration into a robust CAD system for efficient design of RFIC circuits.

A CAD–CAE integration approach using feature-based multi-resolution and multi-abstraction modelling techniques

In spite of the widespread use of CAD systems for design and CAE systems for analysis, the two processes are not well integrated because CAD and CAE models inherently use different types of geometric models and there currently exists no generic, unified model that allows both design and analysis information to be specified and shared. In this paper, a new approach called the CAD/CAE-integrated approach is proposed and implemented by a feature-based non-manifold modelling system. The system creates and manipulates a single master model containing different types of all of the geometric models required for CAD and CAE. Both a solid model (for CAD) and a non-manifold model (for CAE) are immediately extracted from the master model through a selection process. If a design change is required, the master model is modified by the feature modelling capabilities of the system. As a result, the design and analysis models are modified simultaneously and maintained consistently. This system also supports feature-based multi-resolution and multi-abstraction modelling capabilities providing the CAD model at different levels of detail and the CAE model at various levels of abstraction.

3D virtual apparel design for industrial applications

The integration of physics-based models within CAD systems for garment design leads to highly accurate cloth shape results for virtual prototyping and quality evaluation tasks. To this aim, we present a physics-based system for virtual cloth design and simulation expressly conceived for design purposes. This environment should allow the designer to validate her/his style and design option through the analysis of garment virtual prototypes and simulation results in order to reduce the number and role of physical prototypes. Garment shapes are accurately predicted by including material properties and external interactions through a particle-based cloth model embedded in constrained Newtonian dynamics with collision management, extended to complex-shaped assembled and finished garments. Our model is incorporated within a 3D graphical environment, and includes operators monitoring the whole design process of apparel, e.g. panel sewing, button/dart insertion, multi-layered fabric composition, garment finishings, etc. Applications and case studies are considered, with analysis of CAD modelling phases and simulation results concerning several male and female garments.

CAD and CAE Integration Using Multi-Abstraction Mon-Manifold Modelling Method

AbstractIn spite of the widespread use of CAD systems for design and CAE systems for analysis, the two processes are not well integrated because CAD and CAE models inherently use different types of geometric models and there currently exists no generic, unified model that allows both design and analysis information to be specified and shared. In this paper a new approach called the CAD/CAE-integrated approach is proposed that creates and manipulates a single master model containing different types of all of the geometric models required for CAD and CAE. Both a solid model (for CAD) and a non-manifold model (for CAE) are immediately extracted from the master model through a selection process. If a design change is required, the master model is modified by the feature modelling capabilities of our system. As a result, the design and analysis models are modified simultaneously and maintained consistently. This system also supports feature-based multi-resolution and multi-abstraction modelling capabilities pr...

Sketching, concept development and automotive design

Sketching and its key role in concept design are identified, and the particular circumstances of automotive design described. A brief summary of work in the general field of concept sketching and visual thinking is presented. The particular characteristics of automotive design sketches; form lines, crown lines, area lines, shading and colouring are described, and a de-layering analysis undertaken. This demonstrates the primacy of form lines in the automotive design sketch. Observations, by video, of post-graduate students and six professional designers while sketching confirm the importance of the form lines in the design process, the interactive and iterative nature of concept development and the central role of the activity of sketching in this process. It is proposed that the design of CAD systems to support concept development must take account of the importance of sketching activity.

EMC Design CAD Systems for Printed Circuit Boards

EMC Design CAD Systems for Printed Circuit Boards

Construction of PC-based intelligent CAD system for cold forging process design — integration of CAD system and development of input method

The PC-based intelligent CAD system for cold forging process design has been developed in past research. The conventional system carries out the data input for every specific shape, and the process planning reasoning is carried out on the basis of the database made for each shape. By choosing this system constitution, it was advantageous to construct each inference system small-scale. However, the multiple of database and input/output system becomes a problem, when it is constructed by classifying system. Though system of one piece is small-scale, it becomes large as a whole system. It is necessary to integrate individual system in order to solve this problem. Construction of the input/output system that can deal with all products and the smart database become necessary for the reason. In this study, we developed the integrated process design system that constructed with classifying in order to avoid the multiple of the database. In this paper, input method of shape data that can deal with all product form is proposed. It is possible to deal with the identical format for all product forms by using this input method.

A component agent based open CAD system for collaborative design

The competitive market requires rapid product development. Virtual product development is a new development mode in this network times. It is featured by its dynamic development alliance, i.e., those partners are distributed in the world. This paper presents an open-system architecture for a collaborative CAD system supporting virtual product development. The software component technology is adopted to build the system. A component is a reusable application whose data and methods are exposed, and can be accessed and operated by other applications. In this system, each building element or assembly is designed as an independent component. The component agent (CA) method is used as the basic system modules. To manage these distributed CAs, a web-based interface manager is provided. The assembly shop is a product design space based on those CAs and the interface manager. To manage the collaborative session, a web-based design session manager is proposed. This paper describes such a system architecture.