• Elastomers and Composites
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• 제47권4호
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• pp.347-354
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• 2012

사출성형에 CAE (Computer Aided Engineering)을 적용함으로써 사출 성형품 설계와 공정조절에 큰 도움이 된다. 또한 성형의 효율성을 최대화하고 개발기간의 단축, 그리고 고품질 제품을 확보하는데 도움이 크다. 특히 신제품 개발에 대한 설계방안을 제시하고 실패율을 감소시킬 수 있다. 현재 사출성형의 CAE는 2D는 물론 3D도 해석이 가능한데 이 두 가지 방식은 약간의 차이를 가짐에도 불구하고 해석 상 차이에 관한 비교 및 일반적인 가이드라인이 정해져 있지 않다. 본 연구에서는 제품의 두께, 형상 그리고 유한요소 수에 따른 2차원 해석과 3차원 해석을 비교하였다. 그리고 실험을 통해 얻은 캐비티 내의 압력과 온도를 해석결과와 비교하였다. 본 연구를 통하여 사출성형의 2D해석과 3D해석에 대한 가이드라인을 제시하고자 하였다.

• 한국소성가공학회:학술대회논문집
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• 한국소성가공학회 2001년도 추계학술대회 논문집
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• pp.190-194
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• 2001

The integration of rapid prototyping and tooling has the potential for the rapid net shape manufacturing of three-dimensional parts with geometrical complexity. In this study, a new rapid prototyping process, transfer type of Variable Lamination Manufacturing (VLM-ST), was proposed to manufacture net shape of 3-D prototypes. In order to examine the efficiency and applicability of the proposed process, various 3-D parts, such as a world-cup logo, and extruded cross and a knob shape, were fabricated on the apparatus. In addition, the new rapid tooling process, which is a triple reverse process, was proposed to manufacture of 3-D functional part using VLM-ST prototypes and the plastic part of the knob shape was produced by the new rapid tooling process.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2001년도 하계종합학술대회 논문집(5)
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• pp.93-96
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• 2001

Tactile display devices use an array of pins mounted in the form of a matrix to present three-dimensional shapes to the user by raising and lowering. With a denser matrix of mounted pins, it can be expected that shape identification will be become easier and the time required for identification will also become shorter, but that problems of difficulty in fabrication will arise. It is necessary to consider such trade-offs in the development of such devices. This study conducted experiments to study the effect of pin pitch on shape identification as Part of the fundamental investigation of this subject. The experiment used three tactile display devices with pin pitches of In, 2mm and 3mm for geometrical shape identification, with response time and rate of misidentification taken as the performance data. Surfaces, edgs and vertices of three-dimensional shapes were used as the shape primitives for displayed shapes and several of each type were selected for presentation. The results obtained revealed that performance has different relationships to pin pitch with different shape primitives.

• 기술사
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• 제27권3호
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• pp.121-131
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• 1994

3차원 자유 형상 곡면으로 이루어진 선형을 부분적으로 표현하기란 매우 힘들다. 선박 설계에 컴퓨터를 이용한 기술이 적용되기 시작하면서, 기하학적 모델링 기법이 개발되어 왔다. 선형 모델링에서,곡률 변화가 심한 선체 곡면의 국부적인 곡면 형상을 Blending 기법을 써서 표현하는 연구는 이루어지지 않았다. Blend곡면을 써서, 설계시에 도면상에 표시되는 작은 곡면을 부드럽게 표현하는 방법을, 선체표면과 돌출된 접합 부분을 Blending 하고져 하였다. 본 연구에서는, 두개의 Base곡면에 Blend반지름을 입력 했을 때, Blend곡면에 Blending방법을 이용하여 공간 좌표인 Offsets 데이터를 얻을 수 있도록 선박 설계에 적용하여 보았다.

• 한국공작기계학회:학술대회논문집
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• 한국공작기계학회 2003년도 춘계학술대회 논문집
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• pp.428-432
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• 2003

The technical combination of RP and RT has a potential for rapid manufacturing of three-dimensional parts. In the present work a new RP system, $VLM-_{ST}$, is proposed to manufacture net shapes of 3D prototypes. ㅁ human head shape and a kob shape are manufactured by the $VLM-_{ST}$ apparatus. In addition, a new RT technology, which utilizes a RTV molding technique and a triple reverse process technique, is proposed to manufacture net shapes of 3D plastic parts using prototypes of $VLM-_{ST}$. A plastic part of the knob shape os produced by the proposed RT technology. The combination of the proposed RP and RT enables the manufacturing of a plastic knob within two days.

• 한국소성가공학회:학술대회논문집
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• 한국소성가공학회 2005년도 추계학술대회 논문집
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• pp.277-280
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• 2005

A shape optimization is applied to achieve a design objective in three-dimensional forging processes. In multi-stage forging processes, among the important design aspects, the die shape fur preforming is regarded as the design variable since it influences the forged part relatively higher than the others. The rigid-plastic finite element method and the sensitivity method are employed and formulated to solve a formulated optimization problem. An approximation scheme is also used for the direction search during the optimization. The upset forging of a square box is selected as a test example in order to demonstrate and verify the optimization process of this study. After the optimization, the optimized shape of the die yields a finial product of desire shape.

• 한국의상디자인학회지
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• 제18권1호
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• pp.169-181
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• 2016

This study analyzed the characteristics and patterns of men's drawers panties to get basic data for their design. For this, drawers panties in 7 different brands (4: domestic brands, 3: imported brands) in terms of a front-center shape were collected, and the shape of men's drawers panties, characteristics of the materials, dimensions & type of patterns by the part and front-center patterns were analyzed. The study results found the followings: First, in terms of the shape of men's drawers panties, the front-center part were designed to rest the penis and scrotum in a natural and comfortable manner without a pee slit. They were seamless on the sides except for one product with side seams. Second, the drawer panties were made of elastic polyurethane materials. Specifically, domestic brand items used warm, elastic and durable nylon, polyester and rayon and polyurethanes while imported brands were mostly made of absorbent and sanitary polyurethanes. Third, regarding a size of drawer panties by part, imported brands were large in waist circumference. In terms of waist breadth at the front center, there was difference depending on an oval type. In addition, the front length at the front center differed by product, revealing difference in three-dimensional effect at the front center. The side length also differed greatly by product, which means that there might be a great difference in wear comfort. Fourth, in terms of the patterns of men's drawers panties, there was difference in side seams, center back seam and front-center patterns. Among a total of 7 products, only one product had side seams, and center back seams were found in two products only. Fifth, in terms of front-center patterns, the drawer panties can be divided into three types, creating three-dimensional effect not to give any pressure on the crotch: i) the cutting line only at the bottom of the front center part where the penis is rested, ii) puff created at the front center by adding a transverse line to the center line, iii) cutting transverse line to separate the penis from the testicles.

• 보존과학회지
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• 제35권1호
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• pp.71-80
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• 2019

This study examined the applicability of digital technologies based on three-dimensional(3D) scanning, modeling, and printing to the restoration of damaged artifacts. First, 3D close-range scanning was utilized to make a high-resolution polygon mesh model of a roof-end tile with a missing part, and a 3D virtual restoration of the missing part was conducted using a haptic interface. Furthermore, the virtual restoration model was printed out with a 3D printer using the material extrusion method and a PLA filament. Then, the additive structure of the printed output with a scanning electron microscope was observed and its shape accuracy was analyzed through 3D deviation analysis. It was discovered that the 3D printing output of the missing part has high dimensional accuracy and layer thickness, thus fitting extremely well with the fracture surface of the original roof-end tile. The convergence of digital virtual restoration based on 3D scanning and 3D printing technology has helped in minimizing contact with the artifact and broadening the choice of restoration materials significantly. In the future, if the efficiency of the virtual restoration modeling process is improved and the material stability of the printed output for the purpose of restoration is sufficiently verified, the usability of 3D digital technologies in cultural heritage restoration will increase.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1991년도 한국자동제어학술회의논문집(국내학술편); KOEX, Seoul; 22-24 Oct. 1991
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• pp.715-719
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• 1991

In manufacturing process, usually 2-dimensional part drawing is used as a basic data. If a designer wants to recognize 2-dimensional drawing and formulate 3-dimensional shape, a proper feature recognition rule is required as a prerequisite step. These rules are converted Into knowledge base, should be ed separately in the recognition program and can be referenced In similar way of database application. In this paper, basic feature recognition rules are addressed in structure type knowledge base, and the application system is formulated which can be operated separately with existing data driven program.

• 한국의류학회지
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• 제30권11호
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• pp.1598-1607
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• 2006

The purpose of this study was to analyze the proportion of gathered skirts using a three-dimensional measurement system. And in this experiment, we have attempted to accumulate three-dimensional data of wearing model and find out adequate methods for analyzing shape of clothes. The experimental design consists of two factorial designs. We established three different kinds of fabrics, ratio of gathers. The measurement tool for three-dimensional model was whole body 3D scanner(Exima-WBS2H). Analysis program used in experiment is RapidForm 2004 PP1 and Pattern Design 2000. Data analysis utilizes SPSS WIN 10.0 Package. As the results show, there were different effect of gather and proportion of shapes among the measurements of width, thickness and areas made by different lines of vision in cross-sectional silhouette. And there were difference shapes of section area at each part of gathered skirts between vertical-outline silhouette and vortical-plane silhouette made by gathering conditions. And also the cross-sectional silhouettes and vertical silhouettes were related to shape of clothes.