• 한국원자력학회:학술대회논문집
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• 한국원자력학회 2003년도 추계학술발표대회 요약집
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• pp.475.2-475.2
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• 2003

• 한국자기학회:학술대회 개요집
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• 한국자기학회 2008년도 Asian Magnetics Conference
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• pp.145.1-145.1
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• 2008

• 한국CDE학회논문집
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• 제11권2호
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• pp.128-137
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• 2006

In this paper, a CAD/CAE integrated optimal design system is developed, in which design and analysis process is automated using CAD/CAE softwares for a complex model in which the modeling by parametric feature is not easy to apply. Unigraphics is used for CAD modeling, in which the process is automated by using UG/Knowledge Fusion for modeling itself and UG/Open API function for the other functions respectively. Structural analyses are also carried out automatically by ANSYS using the imported parasolid model. The developed system is applied for the PLS(Plasma Lighting System) consisting of more than 20 components, which is a next generation illumination system that is used to illuminate stadium or outdoor advertizing panel. The analyses include responses by static, wind and impact loads. As a result of analyses, tilt assembly, which is a link between upper and lower body, is found to be the most critical component bearing higher stresses. Experiment is conducted using MTS to validate the analysis result. Optimization is carried out using the software Visual DOC for the tilt assembly to minimize material volume while maintaining allowable stress level. As a result of optimization, the maximum stress is reduced by 57% from the existing design, though the material volume has increased by 21%.

• 한국CDE학회논문집
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• 제4권4호
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• pp.327-338
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• 1999

In this paper, we propose the framework of an integrated design system as a CAD system of a new concept that can incorporate the design information. Current CAD systems are powerful in representing the shape of a product with solid models but cannot provide the design information that is used or created in designing the product. Therefore an integrated design system is proposed to enable the storage and usage of the design information in addition to the shape manipulation. In order to represent the design information, we define element object that represents design element such as a part, a sub-assembly or an assembly by using object-oriented methodology. The element object carries various design information such as design parameters, documents, catalogues, functions, and behaviors as well as shapes. By using the stored information, the system can provide a designer with some functions to assist design activity such as interrogating necessary information, setting design parameters and goals, and constructing constraints among design elements. A mailing system is also constructed among element objects to assist a collaborative design. In addition, an evolutionary design method using genetic algorithms is realized within the proposed framework.

• International Journal of CAD/CAM
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• 제2권1호
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• pp.39-44
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• 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.

• 한국고분자학회:학술대회논문집
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• 한국고분자학회 2006년도 IUPAC International Symposium on Advanced Polymers for Emerging Technologies
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• pp.300-300
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• 2006

Nondestructive nanostructural analysis is indispensable in the development of nano-materials and nano-fabrication processes for use in nanotechnology applications. In this paper, we demonstrate for the first time a quantitative, nondestructive analysis of nanostructured thin films supported on substrates and their templated nanopores by using grazing incidence X-ray scattering and data analysis with a derived scattering theory. Our analysis disclosed that vertically oriented nanodomain cylinders had formed in 20-100 nm thick films supported on substrates consisting of a mixture of poly(styrene-b-methyl methacrylate) (PS-b-PMMA) and PMMA homopolymer, and that the PMMA nanodomains were selectively etched out by ultraviolet light exposure and a subsequent rinse with acetic acid, resulting in a structure consisting of hexagonally packed cylindrical nanopores.

• 한국통신학회논문지
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• 제25권4B호
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• pp.734-742
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• 2000

기존의 거리영상을 이용한 모델베이스기반 3차원 물체인식에서는 주로 거리영상 분할과정을 통한 면정합이나 그래프매칭 등의 방법을 이용하였으나, 이러한 방법은 인간의 인식체계와는 동떨어져 있는 경우가 대부분이다. 본 논문에서는 인간의 인식체계와 유사한 체적기반의 수퍼쿼드릭(superquadric) 물체표현과 이를 확장한 물체인식과정을 보인다. 먼저 3차원 물체에 대한 체적특성을 수퍼쿼드릭 계수를 이용한 부품기반 수퍼쿼드릭 모델(PBSM ; part-based superquadirc model) 로 기술하며, 면 특성 및 체적소간의 접합관계 등을 함께 이용하여 물체의 일부 가려짐이나 시점에 의한 비선형적인 형상변화(nonlinear shape change)에도 강건하도록 한다. 입력되는 물체로부터 추출된 수퍼쿼드릭 계수와 모델물체의 계수들간의 매칭을 거쳐 인식에 이른다. 본 논문에서는 실험결과를 통하여 이러한 병합된 방법이 임의의 기계조립 부품의 위치와 자세를 판정하고 인식하는데 유용함을 입증하였다.

• 한국CDE학회논문집
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• 제11권4호
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• pp.289-302
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• 2006

It is becoming a common trend that many designers work on a very complex assembly together in a collaborative environment. In this environment, every designer should be able to see the whole assembly in a full detail or in a rough shape at least. Even though the hardware technology is being improved very rapidly, it is very difficult to display a very complex assembly at a speed to allow smooth interactions for designers. This problem could be solved if a designer could manipulate his portion of the assembly in a full resolution while the remaining portion of the assembly is displayed in a rough resolution. It is also desired that the remaining portion is converted to the full resolution when needed. To realize this environment, the capabilities to simplify the portions of an assembly and to reset to the original resolution should be added to the current CAD systems. Thus operators realizing multi-resolution on B-rep are proposed in this paper. They are: wrap-around, smooth-out, and thinning operator. Through appropriately applying these operators sequentially, an assembly model of any desired resolution can be easily generated. Of course, the assembly can go back to the finer resolution. In this paper, the data structures and the processes to realize these operators are described and a prototype modeling system with these operators is also demonstrated.

• 산업공학
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• 제21권1호
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• pp.131-140
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• 2008

To shorten product development time and cost, integrated information managements of product, manufacturing process and resource are essential. In the area of material addressing, process engineers should make their decisions in the manner of collaborative engineering in order to reduce the manufacturing preparation time and cost in the product development and production. A digital virtual factory which is an united digital model of entire factory could be very useful for these areas. In this paper, the digital virtual factory is constructed and used for material addressing and analysis of an automotive general assembly shop. We developed the material addressing system for automotive general assembly shops using digital virtual factory models and nesting algorithms, and applied it to realistic problems of a Korean automotive company as an convenient and effective way of material addressing.

• 한국경영과학회지
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• 제37권3호
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• pp.39-55
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• 2012

This paper presents an endosymbiotic evolutionary algorithm (EEA) to solve both problems of line balancing and model sequencing in a mixed-model two-sided assembly line (MMtAL) simultaneously. It is important to have a proper balancing and model sequencing for an efficient operation of MMtAL. EEA imitates the natural evolution process of endosymbionts, which is an extension of existing symbiotic evolutionary algorithms. It provides a proper balance between parallel search with the separated individuals representing partial solutions and integrated search with endosymbionts representing entire solutions. The strategy of localized coevolution and the concept of steady-state genetic algorithms are used to improve the search efficiency. The experimental results reveal that EEA is better than two compared symbiotic evolutionary algorithms as well as a traditional genetic algorithm in solution quality.