• 산업공학
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• 제25권3호
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• pp.309-318
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• 2012

Forecasting probability or likelihood of technology development success has been a crucial factor for critical decisions in technology management such as R&D project selection and go or no-go decision of new product development (NPD) projects. This paper proposes an analytic network process (ANP) approach to forecasting of technology development success. Reviewing literature on factors affecting technology development success has constructed the ANP model composed of four criteria clusters : R&D characteristics, R&D competency, technological characteristics, and technological environment. An alternative cluster comprised of two elements, success and failure is also included in the model. The working of the proposed approach is provided with the help of a case study example of MRAM (magnetic random access memory) technology.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2002년도 ICCAS
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• pp.91.1-91
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• 2002

1. Introduction Present study presents the basic concept of a Solid Freeform Fabrication System using a rapid prototyping procedure and optimal control for a transferring and accumulating system. And it developed a novel rapid prototyping process that can use ceramic or metal as well as polymer as a basic material. 2. Solid Freeform Fabrication System 2.1 Basic Theory A 3D CAD data of the model is converted to the 2D cross-section data of the slides. A ceramic or metal tape of thickness 0.5-1.5mm is cut by a laser beam with the cross-section data of the slide. A 3D model was obtained by transferring and accumulating the slides. The final product is manufactured by sin...

• Nuclear Engineering and Technology
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• 제54권9호
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• pp.3415-3421
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• 2022

This paper is aimed to find out the impact of the geometrical parameters, mainly the radius and the height of a cylinder, on the SGEMP response including the famous scaling law in the classical cylinder model using a homemade PIC code UNIPIC-3D. We computed the electric fields at the center and at the edge on the emission head face with different radii and heights under normal X-rays incidence. The results show that the electric field will increase with the radius but decrease with the height. We analyze the scaling law that links the electric field product and fluence product, and whereafter an irreconcilable contradiction raises when the radius is changeable, which limits the application range of the scaling law. Moreover, the field-height-radius relation is found and described by a combination of logarithmic and minus one-quarter numerical fitting law firstly. Particle and magnetic field distributions are used to explain all the behaviors of the fields reasonably. All the findings will assist the evaluation of SGEMP response in spacecraft protection.

• Asian Journal of Innovation and Policy
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• 제10권3호
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• pp.274-293
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• 2021

Utilizing outside knowledge for innovation is an important task for companies in the competitive economy. Due to the rapid advance in the internet communication technology, the number and quality of innovation sourcing methods are increasing. We select co-creation, personalization and in-house R&D as the representative forms of innovation sourcing and suggest a game theory model that enables the comparative analysis between them. The decision and surplus outcome of the innovation mechanisms are compared under various settings of the input parameters of the model. The stakeholders voluntarily participate into all mechanisms when the product price is moderately high and the participation cost is low, while co-creation is the only feasible one when the product quality is niche. When the participation cost is relatively high, personalization outperforms co-creation.

• 대한기계학회논문집A
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• 제27권5호
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• pp.807-814
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• 2003

3D printers are widely used to verify the designs in the early stage of product development, and are required to have short build time. However, the build time is still too long for a quick design review for engineers. This research focuses on how to split the prototype in order to reduce the build time and improve surface roughness. In order to verify the feasibility of prototype splitting, the build time and the roughness have been experimentally measured for various parts and build orientations. Based on the experimental results an expert system was developed for splitting the original CAD mod el by using an efficient splitting method. It can recommend a splitting plane based on build time, surface roughness and the number of divided parts. It is shown that the model splitting reduces the build time significantly and improves surface quality wit bout rough surfaces where the support was removed.

• 한국건설관리학회논문집
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• 제23권6호
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• pp.119-124
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• 2022

최근 적층제조기술을 활용한 건축 상품 시공방법이 제안되고 있다. 적층제조기술은 건축 상품 시공과정을 자동화하여 작업자 안전을 확보한다. 또한, 비정형 형상의 구현효율성이 높아 건축물과 기반시설제조과정에 적용 가능성을 주목 받고 있다. 적층제조기술은 현대의 건설 산업에서 요구되는 컴퓨터 기반의 시공자동화, 자원관리, 시공기간예측 등을 만족할 수 있는 기술이다. 하지만, 아직 부족한 누적 데이터와 표준, 규제, 운영방법 등에 의해 산업 적용이 제한되고 있다. 본 연구에서는 건축 적층제조기술 적용가능성을 분석하기 위해 2개의 적층제조시스템으로 건축 상품을 제조한다. 또한 각 건축 상품은 적층생산결정모델을 통해 적합한 제조시스템으로 투입하는 방법이 적용되고, 실증 실험을 통해 제조과정의 문제를 확인한다. 결과적으로 건축 상품의 품질 향상을 위한 확장된 적층생산결정모델을 제안한다.

• 한국정보통신학회논문지
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• 제12권4호
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• pp.611-619
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• 2008

본 논문에서 구현한 2.5D 맵핑(mapping) 시스템은 다양한 질감과 패턴에 따른 패션 의상의 모델 사진 이미지를 그대로 살려 외각선 영역 위에 드레이핑(draping)함으로써 새로운 디자인을 창출할 수 있고, 직접 샘플이나 시제품을 제작하지 않고도 시뮬레이션만으로 의상 작품을 확인할 수 있다. 또한 원단 디자인과 최종 제품의 상태를 정확하게 예측할 수 있는 기능을 제공하며, 원단과 모델 사진 이미지의 데이터베이스 구축으로 쉽고 빠르게 드레이핑함으로써 패션 업계의 경쟁력 향상과 비용 절감 효과를 가져 올 수 있다. 2.5D 맵핑 시스템은 보다 자연스러운 드레이핑을 위하여 메쉬 워프 알고리즘 모듈, 명암 추출과 적용 모듈, 맵핑 영역 추출 모듈, 메쉬 생성과 변형 모듈, 2.5D 맵핑 모듈로 구성하여 구현하였다. 향후 연구과제는 2.5D 맵핑 시스템의 구현 기술을 기반으로 하여 3D 의복 기술과 3D 인체 구현 기술을 접목한 3D 패션 디자인 시스템을 연구하여 2.5D 맵핑 기술의 표현 한계를 극복할 계획이다.

• Interaction and multiscale mechanics
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• 제1권2호
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• pp.279-301
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• 2008

This paper develops a 3D homogenization based continuum damage mechanics (HCDM) model for fiber reinforced composites undergoing micromechanical damage under monotonic and cyclic loading. Micromechanical damage in a representative volume element (RVE) of the material occurs by fiber-matrix interfacial debonding, which is incorporated in the model through a hysteretic bilinear cohesive zone model. The proposed model expresses a damage evolution surface in the strain space in the principal damage coordinate system or PDCS. PDCS enables the model to account for the effect of non-proportional load history. The loading/unloading criterion during cyclic loading is based on the scalar product of the strain increment and the normal to the damage surface in strain space. The material constitutive law involves a fourth order orthotropic tensor with stiffness characterized as a macroscopic internal variable. Three dimensional damage in composites is accounted for through functional forms of the fourth order damage tensor in terms of components of macroscopic strain and elastic stiffness tensors. The HCDM model parameters are calibrated from homogenization of micromechanical solutions of the RVE for a few representative strain histories. The proposed model is validated by comparing results of the HCDM model with pure micromechanical analysis results followed by homogenization. Finally, the potential of HCDM model as a design tool is demonstrated through macro-micro analysis of monotonic and cyclic damage progression in composite structures.

• 한국CDE학회논문집
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• 제22권1호
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• pp.37-43
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• 2017

3D printing techniques can be used in various application fields and many researches have been reported. FDM (Fused Deposition modeling) can make multi-material or multi-color models with the simultaneous use of two or more filaments. In a dual-nozzle FDM printers, while the active nozzle is working, the remaining nozzle will be idle. The remaining molten resins inside an idle nozzle can ooze out unwantedly. The spill over from the resting nozzle produces unwanted remaining on the fabricated product. In this research, we suggest a method for optimizing building position of a model to minimize the unwanted spill-over that could possibly contaminate the final product. The method is based on minimizing the two intersection volumes. The first intersection volume is obtained by intersecting the volume defined by the first material and the Minkowski sum between the volume of the first material and the vector obtained by subtracting the center point of the first nozzle from the center point of the second nozzle. The second intersection volume can be obtained by reversing the role of the first and second volumes and nozzles. Some results obtained from the implementation using the Parasolid (Siemens) geometric modeling kernel is presented.

• 한국정보통신학회논문지
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• 제11권5호
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• pp.875-881
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• 2007

최근 멀티미디어 분야에서 새로운 수익모델로 주목받고 있는 PPL(Product Placement)을 활용하여 멀티미디어 콘텐츠 화면의 주목도를 분석하였다. 이를 위해 컴퓨터 화면을 9사분면으로 분할한 후 각각의 위치에 2D, 3D 숫자 정지 영상, 숫자 부분 동영상, 동영상 등을 배치하여 영상의 유형과 위치에 따라 사용자의 주목도에 어떠한 변화가 있는가에 관해 연구하였다. 분석 결과 2D 숫자 정지 영상과 동영상의 경우엔 5사분면에 높은 주목도를 나타냈으며, 3D 숫자 정지영상과 동영상의 경우 역시 일관성 있게 5사분면에 높은 주목도를 나타냈다. 특히 정지영상 내 동영상이 존재하는 부분 동영상의 경우엔 동영상이 존재하는 분면에 압도적인 주목도를 나타냈다. 이는 영상의 노출형태가 사용자의 주목도에 유의미한 영향을 미치는 것으로 정지영상보다는 동영상 형태의 노출이 사용자의 주목효과(attention of effects)를 높일 수 있는 것을 의미한다. 이 같은 연구결과는 멀티미디어 콘텐츠 화면에서의 PPL 제작 시 어떤 위치에 PPL을 배치해야 사용자의 주목도를 극대화할 수 있는가에 대한 문제를 해결하는데 기여할 수 있을 것으로 사료된다.