• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 2009.10a
• /
• pp.735-736
• /
• 2009

• Korean Journal of Computational Design and Engineering
• /
• v.6 no.4
• /
• pp.236-243
• /
• 2001

A key factor far realizing the internet-based virtual manufacturing system(VMS) and virtual enter-prise(VE) is how to precisely and effectively represent the machine elements and mechanics. In this paper, we present methods to represent the numerically controlled machine tools in the internet environment. The method is composed of: 1) geometrical modeling of the machine tools, 2) kinematic modeling for the movements of the machine tools, and 3) representing the developed model in the internet infrastructure. Based on the models. a web-based virtual machine tools (WVMT) is developed, and it can be accessed at hrrp://wvmt.postech.ac.kr. The WVMT can be used for various purposes: 1) web-based virtual manufacturing system, 2) web-based CAM system, and 3) CNC educational tools for the vocational school through internet.

• CDE review
• /
• v.4 no.2
• /
• pp.36-41
• /
• 1998

To survive in the intensive world wide automotive market, more and more automotive companies are investing their resources into concurrent engineering systems (CE) based on the combined CAD/CAM/CAE/ PDM technology. The main objectives of CE in automotive companies are the quality improvement of products and the reduction of cost and time to market. Remarkable effects are appearing from some of these companies. As shown in this paper, these successful automotive companies have been focusing on establishing the new process and methodology in applying CE into their car development process.

• The Journal of the Korean dental association
• /
• v.50 no.3
• /
• pp.118-125
• /
• 2012

CAD/CAM systems (computer-aided design / computer-aided manufacturing) used for decades in restorative dentistry have its application to implant dentistry. This study aimed to overview CAD/CAM systems used implant dentistry, especially emphasizing custom implant abutments manufacturing. CAD/CAM custom abutments present the advantages of being specific to each patient and providing a better fit than the stock and cast custom abutments. This cutting edge technology of virtual-designed and computer-milled implant abutments will likely replace traditional implant restorative protocols and become the standard for implant dentistry in the foreseeable future.

• Korean Journal of Computational Design and Engineering
• /
• v.2 no.4
• /
• pp.253-266
• /
• 1997

Pencil-curve machining, which is a single-pass ball-end milling along a concave edge on adie surface, is widely employed in die-surface machining. The cutter-path used for pencil-curve machining, which is the trajectory of the “ball-center point” of a ball-endmill sliding along a concave-edge region on the die surface, is called pencil-curve. Presented in the paper is a pencil-curve tracing algorithm in which “concave-type” sharp edges are computed from a “virtually digitized” model of the tool-envelope surface. The resulting “initial” pencil-cures are then refuted by applying a series of fairing operations. illustrative examples and methods for enhancing accuracy are also presented. The proposed pencil-curve tracing algorithm has been successfully implemented in a commercial CAM system specialized in die-machining and in the CAD/CAM system CATIA.

• International Journal of CAD/CAM
• /
• v.2 no.1
• /
• pp.39-44
• /
• 2002

This paper presents a structure and architecture of an integrated simulation method (ISM) to meet the requirements of virtual factory engineering (VFE). Combining CAD, VR and discrete event simulation techniques, the ISM provides static and dynamic simulation functions for implementation of VFE throughout the lifecycle. The static simulation can be used to evaluate the factory layout. The dynamic simulation enables us to evaluate ergonomics of factory, process performance of production system, feasibility of production plan and operation of factory, and to train operators safely, which cover the whole VFE lifecycle. The principles of the key techniques of VFE, including virtual factory data management system (VFDMS), static and dynamic simulation, are also discussed. To demonstrate and validate the ISM, a case study has been carried out in an assembly factory.

• Transactions on Control, Automation and Systems Engineering
• /
• v.4 no.1
• /
• pp.23-31
• /
• 2002

We proposed a concept of a desktop micro device factory for visually servoed teleoperated microassembly assisted by a virtual reality (VR) interface. It is composed of two micromanipulators equipped with micro tools operating under a light microscope. First a manipulator, control method for the micro object to follow a planned trajectory in pushing operation is proposed undo. vision based-position control. Then, we present the cooperation control strategy of the micro handling operation under vision-based force control integrating a sensor fusion framework approach. A guiding-system based on virtual micro-world exactly reconstructed from the CAD-CAM databases of the real environment being considered is presented for the imprecisely calibrated micro world. Finally, some experimental results of microassembly tasks performed on millimeter-sized components are provided.

• Korean Journal of Computational Design and Engineering
• /
• v.1 no.3
• /
• pp.203-214
• /
• 1996

An information sharing system, namely World Design View, is developed for browsing product design data on the World Wide Web environment. For the last few years information sharing has been rapidly emerging as an important research issue in the areas of concurrent engineering, product data management, virtual manufacturing, and so on. Since we are mainly concerned with product development, the key information that needs be communicated and shared is product data. The developed system puts the major advantages of STEP, OODB, and VRML together. The STEP standard provides a consistent data exchange format and application interfaces among different CAD/CAM systems. OODB is efficient and effective in dealing with complex data structures often found in engineering applications. Virtual worlds for 3-D product models can be created by VRML which is networked via the global Internet and hyperlinked with WWW. The World Design View system can support for members of virtual design teams, possibly distributed all over the world, to share 3-D shape information quickly and easily.

• International Journal of CAD/CAM
• /
• v.8 no.1
• /
• pp.41-44
• /
• 2009

This paper describes an implementation of virtual teeth modeling for a haptic dental simulation. The system allows dental students to practice dental procedures with realistic tactual feelings. The system requires fast and stable haptic rendering and volume modeling techniques working on the virtual tooth. In our implementation, a volumetric implicit surface is used for intuitive shape modification without topological constraints and haptic rendering. The volumetric implicit surface is generated from input geometric model by using a closest point transformation algorithm. And for visual rendering, we apply an adaptive polygonization method to convert volumetric teeth model to geometric model. We improve our previous system using new octree design to save memory requirement while increase the performance and visual quality.

• Journal of Mechanical Science and Technology
• /
• v.14 no.10
• /
• pp.1089-1103
• /
• 2000

A Problem of relevant interest to some industries is that of obtaining optimum two-dimensional layout. To solve this provlem, one is given a number of rectangular sheets and an order for a specified number of each of certain types of two-dimensional regular and irregular shapes. The aim is to cut the the shapes out of the sheets in such a way as to minimize the amount of waste produced. A DCS (Distributed Control System) is an integrated system which applies the decentralization concept to a control system handling both sequential and analog control. A DCS performs many operations such as data gathering, data processing, data storing and monitoring the operatin conditions for the operator. IN this paper, we propose a genetic algorithm based on rotation parameters from which the best pattern of layout is found as well as a layout method for better performance time. A DCS for the plate cutting process system, which is performed by a virtual system, is also identified.