• Proceedings of the Korean Operations and Management Science Society Conference
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• 2003.05a
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• pp.217-224
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• 2003

ISO 14649 is a new interface (or language) standard for the CAD-CAM -CNC chain, currently under establishment by ISO TC184 SCI and SC4 . Upon completion, it will replace ISO 6983, so called M amp; G codes used for CNC since 1950' s. As the new language is being established, a new CNC controller called STEP-CNC (STEP­compliant CNC), capable of carrying out various intelligent tasks using the new language as an input, receives worldwide attention. In this paper, we present a distributed architecture for STEP-NC system based on the generic paradigm of STEP-NC. The STEP-NC system is consisted of 3 sub-systems: 1) CGS (Code Generation System), 2) CES (Code Edit System), and 3) ACS (Autonomous Control System). Also presented in this paper is algorithm for delta volume decomposition, a crucial algorithm for developing CGS. First method is based on the cutting tool and the second method is based on the turning features commonly used in the shop floor. An illustrative example is given to compare the two methods, and to illustrate usage scenario of the delta volume in the turning STEP- NC system under development.

• Transactions of the Korean Society of Mechanical Engineers
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• v.17 no.5
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• pp.1095-1105
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• 1993

Shape rolling processes to produce H-section beams are numerically simulated by the simplified three-dimensional finite element method. The 2-dimensional finite element method, used for the generalized plane strain condition, is combined with the slab method. Computer simulation results of the 19-passes in H-section beam rolling in practice include the grid distortions, the cross-sectional area changes, the roll separating forces, and the roll torques. Also, the amount of side spread can be found during the multi-pass rolling simulations. The finite element mesh system is remeshed with I-DEAS whenever the billet distorts severely. This study would contribute to CAD/CAM of shape rolling process through the optimal roll pass schedule.

• Korean Journal of Computational Design and Engineering
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• v.8 no.1
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• pp.48-54
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• 2003

In a design-to-manufacturing environment, the product data is shared by various CAD/CAM/CAE systems with little integration or substantial data redundancy. The main purpose of this paper is to build a database containing all the features required for STEP-NC machining and to show how a STEP-NC repository can support the complete process for machining. A STEP-NC database schema has been constructed and several query functions have been built for the purpose of implementing the retrieving system of a STEP-NC database. The EXPRESS data model of ISO 14649 has been mapped to the database data definition language of the Oracle database. To apply the STEP-NC database to an industry example, the ISO 14649 part program has been stored into the STEP-NC database. To implement example scenarios, the sample query interface has been built.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2012.11a
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• pp.225-226
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• 2012

Nowadays the widely used media in architecture include visualizations, animations and three-dimensional models. An optimized 3D digital method using active CAM(Computer Aided Manufacturing) and CNC(Computerized Numerical Control) imaging is developed for accurate shape and 3D measurements in freeform buildings in this paper. In contrast to a conventional building using auto CAD system and others, the proposed active digital optimization is based on a combination of 3D numerical data and parametric 3D model. The objective of this paper is therefore to present digital optimization method for constructability of freeform building. The 3D digital optimization method is appropriate to serious variations in freeform shape. The developed digital optimization method is necessary to be carried out to verify the robustness and accuracy for constructability.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.14 no.6
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• pp.142-148
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• 2015

3D printing technology is a promising technique for fabricating complex 3D architectures based on the CAD/CAM system, and it has been extensively investigated to manufacture structures in the fields of mechanical engineering, space technology, automobiles, and biomedical and electrical applications. Recent advances in the 3D printing of soft structures have received attention for the application of the construction of flexible sensors of soft robotics or the recreation of tissue/organ-specific microenvironments. In this review paper, we would like to focus on delivering state-of-the-art fabrication of soft structures with 3D printing technology and its various applications.

• Transactions of the Korean Society of Mechanical Engineers
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• v.11 no.6
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• pp.1005-1013
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• 1987

For the factory automation and unmanned machine operation, it is very important to manufacture highly reliable and efficient chip breakers for optimal chip control. In this research, using the CALMA CAD/CAM SYSTEM, the manufacturing process of 3-dimensional chip breakers is established. Using the results of the cutting test of the selected chip breakers with double-step grooves, the chip breaking mechanism is schematically analysed. An expression for the chip breaking relation is derived which considers chip material behavior following LUDWIK's stress-strain curve, chip breaking criterion and the shape of chip breakers. This contains the thickness of chip, the radius of chip curl, and the mechanical properties of chip materials. It is found that the expression agrees very closely with the experimental results.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2002.05a
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• pp.69-72
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• 2002

The geometry parameter of tool such as rake angle and clearance angle is defined clearly to solve the difference in communication between design and measurement stage. Using the developed simulation program, wheel is properly determined and end mill can be manufactured accurately. The performance test with well defined end mill provides sufficient information to decide optimal geometry. For machining hardened steel, end mills are designed and manufactured. Optimal rake angle and clearance angle is obtained from performance test. A specific software for automatic end mill production is developed far simulation and fur generation of NC code as Cad/CAM system.

• Journal of the Korean Society for Precision Engineering
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• v.17 no.4
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• pp.48-68
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• 2000

The high-speed machining technology of difficult-to-cut material is needed to achieve the high-efficiency of die manufacturing. The high-speed machining is applied in automobile, airplane and electricityㆍelectro industry etc, because it can improve machining efficiency and productivity with high speed, high power and high rotation. In this study, high speed machinability, tool wear characteristics and its monitoring, characteristics of damaged layer, machinability of difficult-to-cut material, characteristics of a free curved surface and method of CAD/CAM system were introduced to acquire the shortening of machining time, the improvement of machining efficiency and the high quality of machined surface. Therefore, we establish the stabilization condition of difficult-to-cut material machining and present the optimal cutting condition for high-efficiency cutting.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2004.10a
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• pp.471-474
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• 2004

In this paper, a NURBS surface interpolator is proposed which can deal with shapes defined from CAD/CAM programs on a surface basis and can improve contour accuracy. The proposed interpolator is based on newly defined G-codes and includes online tool-path planning suitable for NURBS surface machining. The real-time interpolation algorithm, considering an effective machining method for each machining process and minimum machining time, is executed in an online manner. The proposed interpolator is implemented on a PC-based 3-axis CNC milling system and evaluated through actual machining in terms of machining time and regulation of feedrate and cutting force in comparison with the existing method.

• Computational Structural Engineering
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• v.3 no.3
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• pp.62-65
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• 1990

RISC System/6000은 유닉스 시스템인 AIX를 오퍼레이팅 시스템으로 채택하였고, 기존의 RISC기술에 혁신적인 진보를 이룩하여 가격 대 성능비를 크게 높임과 동시에 시스템의 기능을 극도로 최적화 시킨 새로운 차원의 아이비엠의 고성능 시스템패밀리이다. 이 시스템은 새로운 RISC 시스템 구조인 POWER(Performance Optimization With Enhanced RISC) 개념과 제2세대 수퍼스칼라 기법 및 마이크로 채널 아키텍쳐로 설계되어 있다. 특히 하나의 사이클에서 4개 이상의 명령어를 병렬처리 하도록 설계된 수퍼스칼라 기능을 통하여 복잡한 그래픽 또는 이미지 처리 및 고도의 수치해석 기능이 뛰어나다. RISC시스템/6000은 과학기술계산업무나 멀티사용자의 일반 비즈니스용으로도 모두 뛰어난 범용 컴퓨터로 그래픽 프로세서의 선택과 함께 CAD/CAM이나 그래픽/애니메이션전용 시스템을 구성할 수 있으며, 최고 512 사용자에 이르는 멀티 사용자 시스템을 구성하여 사용할 수 있다. 이전의 유닉스 시스템에 있어서 큰 약점이었던 사용자 인터페이스와 멀티 사용자 및 테스킹이 크게 강화 되었으며, 기존의 IBM 시스템 및 타 기종과도 네트워크 구성이 용이하고 수백여종의 과학기술 적용업무를 이용할 수 있다.