• 재활복지공학회논문지
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• 제9권2호
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• pp.145-151
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• 2015

본 연구에서는 3D 스캐닝에서 획득한 이미지 정보를 바탕으로 3차원 그래픽 제품설계와 3D 프린팅 기술을 적용한 보조기 제작방법을 제시하였다. 뇌성마비 환자를 대상으로 4가지 종류의 보조기를 기존의 수작업이 아닌 전산화된 작업 기술을 적용하여 제작해봄으로써 방법과 절차에 대한 기준을 마련하고, 이 기술이 임상적으로 사용 가능한지 여부에 대해 확인했다. 보조기 사용 시 환자만족도와 보조기 제작시간, 인장강도 등의 비교를 통하여 정량적, 정성적으로 제작방법의 적용 가능성을 검증한 결과 기존의 열가소성 수지가 표출했던 문제를 보완하고 대체가능한 방법이 될 가능성이 있음을 확인하였다.

• 한국정보처리학회논문지
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• 제5권1호
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• pp.86-96
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• 1998

객체 지향 설계 모델에서 클래스 계층구조는 소프트웨어 재사용성과 복잡한 시스템 설계시에 효율적이다. 본 논문에서는 래피드 프로토타입핑 기법을 사용한 객체 지향 클래스 계층 구조 설계 방법을 제시한다. 이 방법은 객체 모델링 단계에서 식별된 클래스들을 새로운 분류 방법을 사용하여 관계성 식별과 유사성을 측정한다. 여기에는 클래스의 속성과 메소드의 측정이 요구된다. 하나의 설계 모듈인 클래스 계층구조는 대화식으로 반복적인 작업을 통하여 생성되며, 각 모듈은 참조 관계, 상속 관계, 복합 관계로 구성된다. 이들 정보는 구형 및 프로그램 유지보수시에 도움을 주기 위하여 테이블에 저장하여 클래스 관계성을 그래프로 표현하고 노드클래스를 아이콘화 하였다. 따라서 새로운 클래스 추가 및 삭제 작업이 용이하여 클래스 계층 구조 재구성과 설계정보 재사용시에 효율적이다. 본 논문에서 제시하는 방법은 프로토타입 시스템으로 뿐만 아니라 실제 시스템에 최종 전환할 수 있기 때문에 시스템 분석, 설계, 구현의 능률을 높일 수 있다.

• 한국시뮬레이션학회논문지
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• 제16권4호
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• pp.23-31
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• 2007

함정 전투체계의 대공전 기능은 전투함의 생존성을 결정짓는 핵심기능이다. 본 논문에서는 차기고속정 전투체계의 대공전 설계에 있어서 효과적인 개발 방법론으로 모델 기반의 시뮬레이션 기법을 적용하고 있다. 적용된 방법론에서는 대공전 기능이 유한상태기계시스템으로 모델링되고 있으며 모델링 결과로 부터 직접 시뮬레이션을 수행하는 모델기반의 시뮬레이션을 통해 모델의 정확성과 운용의 효과성을 평가하여 설계 시스템을 프로토타입핑하였다. 이러한 결과를 토대로 실제 시스템의 특성을 반영하기 위해 HILS 시뮬레이션을 수행하였으며 최종적으로 구현된 시스템을 완성하였다. 모델기반의 시뮬레이션 기법은 단계적이 반복적인 설계과정을 거치게 됨으로써 개발과정에서 발생할 수 있는 위험요소를 최소화 시킬 수 있기 때문에 고비용 및 고신뢰성이 요구되는 국방분야에서 효과적인 개발방법론으로 적용할 수 있다.

• 한국정밀공학회지
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• 제17권9호
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• pp.189-195
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• 2000

RP techniques have their unique characteristics according to the working principles : star-stepped surface of parts due to layer-by-layer stacking low build speed caused by line-by-line solidification to fish one layer and post processing to improve surface finish etc The objective of this study is to propose a new RP technique Variable Deposition Mnanufacturing (VDM) which can make up for the disadvantages of the existing RP techniques and to develop an apparatus to implement the technique. The proposed process can greatly reduce the build time and improve the surface finish of parts generated. Experiments are carried out to obtain the range of temperature of molten material to maintain its fluidity and to investigate the effect of gas cooling on the preservation of the slopes. Some simple shapes such as a line-shape an S-shape and a circle-shape are fabricated from Ethylene Vinyl Acetatecopolymer(EVA) In order to examine the applicability of VDM to more general shapes a tensile specimen and a yo-yo shape were manufactured by the proposed RP method using EVA material as a trial approach. The current basic study shows a high potential of practical use of the proposed VDM process to prototyping of a general three-dimensional shape.

• 대한기계학회논문집A
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• 제28권12호
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• pp.1958-1967
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• 2004

This paper describes the method to rapidly fabricate the large-sized physical model with the envelope model size of more than 600 mm${\times}$ 600 mm${\times}$ 600 mm using two type semi-automatic VLM-ST processes in connection with the reverse engineering technology. The fabrication procedure of the large-sized solid shape is as follows: (1) Generation of STL data from 3D scan data using 3D scanner, (2) generation of shell-type STL data by Boolean operation, (3) division of shell-type STL data into several pieces by solid splitting, (4) generation of USL data for each piece with VLM-Slicer, (5) fabrication of each piece by cutting and stacking according to USL data using VLM-ST apparatus, (6) completion of a shell-type prototype by zigzag stacking and assembly for each piece, (7) completion of a 3D solid shape by foam backing, (8) surface finish of a completed 3D solid shape by coating and sanding. In order to examine the applicability of the proposed method, the miniature of the Mount Rushmore Memorial has been fabricated. The envelope model size of the miniature of the Mount Rushmore Memorial is 1,453 mm${\times}$ 760 mm${\times}$ 853 mm in size. From the result of the fabricated miniature of the Mount Rushmore Memorial, it has been shown that the method to fabricate the large object using two type semi-automatic VLM-ST processes in connection with the reverse engineering technology are very fast and efficient.

• 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.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2004년도 추계학술대회 논문집
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• pp.1295-1298
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• 2004

Selective Laser Sintering(SLS) method is one of Rapid Prototyping(RP) technologies. It is used to fabricate desirable part to sinter powder and stack the fabricated layer. To develop this SLS machine, it needs effective scanning path and the development of scanning device. This paper shows how to make fast scanning path with respect to scan spacing, laser beam size and scanning direction from 2-dimensional sliced file generated in commercial CAD/CAM software. Also, we develop the scanning device and its control algorithm to precisely follow the generated scanning path. Scanning path affects precision and total machining time of the final fabricated part. Sintering occurs using infrared laser which has high thermal energy. As a result, shrinkage and curling of the fabricated part occurs according to thermal distribution. Therefore, fast scanning path generation is needed to eliminate the factors of quality deterioration. It highly affects machining efficiency and prevents shrinkage and curling by relatively lessening the thermal distribution of the surface of sintering layer. To generate this fast scanning path, adaptive path generation is needed with respect to the shape of each layer, and not simply x, y scanning, but the scanning of arbitrary direction must be enabled. This paper addresses path generation method to focus on fast scanning, and development of scanning system and control algorithm to precisely follow generated path.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2005년도 ICCAS
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• pp.2175-2178
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• 2005

Selective Laser Sintering(SLS) method is one of Rapid Prototyping(RP) technologies. It has been used to fabricate desirable part to sinter powder and stack the fabricated layer. Since the sintering process occurs using infrared laser having high thermal energy, shrinkage and curling of the fabricated part occurs according to thermal distribution. Therefore, the fast scanning path generation is necessary to eliminate the factors of quality deterioration. In case of fabricating larger size parts, the unique scanning device and scanning path generation should be considered. In this paper, the development of SLS machines being capable of large size fabrication(800${\times}$1000${\times}$800 mm, W${\times}$D${\times}$H) will be addressed. The dual laser system and the unique scanning device have been designed and built, which employ CO2 lasers and dynamic 3-axis scanners. The developed system allows scanning a larger planar surface with the desired laser spot size. Also, to generate the fast scanning paths, adaptive path generation is needed with respect to the shape of each layer, and not simply x, y scanning, but the scanning of arbitrary direction should be enabled. To evaluate the suggested method, the complex part will be used for the experiment fabrication.

• 제어로봇시스템학회논문지
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• 제22권10호
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• pp.811-816
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• 2016

In light of recently developed 3D printers for rapid prototyping, there is increasing attention on the 3D scanner as a 3D data acquisition system for an existing object. This paper presents a prototypical 3D scanner based on a striped laser light image. In order to solve the problem of shadowy areas, the proposed 3D scanner has two cameras with one laser light source. By using a horizontal rotation table and a rotational arm rotating about the latitudinal axis, the scanner is able to scan in all directions. To remove an additional optical filter for laser light pixel extraction of an image, we have adopted a differential image method with laser light modulation. Experimental results show that the scanner's 3D data acquisition performance exhibited less than 0.2 mm of measurement error. Therefore, this scanner has proven that it is possible to reconstruct an object's 3D surface from point cloud data using a 3D scanner, enabling reproduction of the object using a commercially available 3D printer.

• 품질경영학회지
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• 제42권2호
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• pp.145-152
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• 2014

Purpose: As the number of people directly employed in making things declines, the cost of labour as a proportion of the cost of production and delivery will diminish too. This will make to move the focus of quality management because new manufacturing techniques make it cheaper and faster to respond to changing local tastes Methods: This discussion is induced by understanding that change the point of view of quality. Results: Mark-processing method using a mold of 3D-printer is different from traditional manufacturing methods. Design, rapid prototyping of products produced by the right way, many changes in many industries will be created. Therefore, the design will be more emphasis on the importance of quality. Conclusion: As manufacturing goes digital, a Quality great change is now gathering pace. It will allow things to be made economically in much smaller numbers, more flexibly and with a much lower input of labour, thanks to new materials, completely new processes such as 3D printing. So we must change the vantage point of quality, from process to Design, R&D, and Delivery.