• 한국자동차공학회논문집
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• 제11권3호
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• pp.161-166
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• 2003

In order to improve the fatigue lift of a lower control arm in the vehicle suspension, a new shape optimization procedure is presented. In this approach, the shape control point concept is introduced to reduce the numbers of shape design variables. Also, the two-level orthogonal way is employed to evaluate the design sensitivity of fatigue life with respect to those shape design variables, because the analytical design sensitivity information is not directly supplied from the commercial CAE softwares. In this approach, only the six design variables are used to approximate the shape of lower control arm. Then, performed are only 10 fatigue life analyses including the baseline design, 8 DOE models and the final design. The final design, the best combination obtained from the sensitivity information, can maximize the fatigue lift nearly two times as that of the baseline design, while reducing the 12 percentage of weight than it.

• Bulletin of the Korean Chemical Society
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• 제35권3호
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• pp.805-810
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• 2014

The shape invariant potentials are proved to be exactly solvable, i.e. the wave functions and energies of a particle moving under the influence of the shape invariant potentials can be algebraically determined without any approximations. It is well known that the SWKB quantization is exact for all shape invariant potentials though the SWKB quantization itself is approximate. This mystery has not been mathematically resolved yet and may not be solved in a concrete fashion even in the future. Therefore, in the present work, to understand (not prove) the mystery an attempt of deriving exactly solvable potentials directly from the SWKB quantization has been made. And it turns out that all the derived potentials are shape invariant. It implicitly explains why the SWKB quantization is exact for all known shape invariant potentials. Though any new potential has not been found in this study, this brute-force derivation of potentials helps one understand the characteristics of shape invariant potentials.

• 소성∙가공
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• 제8권5호
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• pp.454-464
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• 1999

A new blank design method is proposed to predict the optimum initial blank shape in the sheet metal forming process. The rollback method for blank shape design takes the difference between the deformed blank contour and the target contour shape into account. the minimization object function R is proposed. Based on the method, a computer program composed of blank design module, FE-analysis module and mesh generation module is developed. The rollback method is applied to square cup, reentrant cross section, L-shaped cup drawing process with the flange of uniform size around its periphery to confirm its validity. The optimum initial blank shape is obtained from an arbitrary blank shape after several modifications. Good agreements are recognized between the numerical results and the published experimental results for initial blank shape and thickness strain distribution. It is concluded that the rollback method is an effective and convenient method for an optimum blank shape design.

• International Journal of CAD/CAM
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• 제8권1호
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• pp.69-72
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• 2009

In this paper, we present a new shape descriptor, which is named Poisson equation-Fourier-Mellin moment Descriptor. We solve the Poisson equation in the shape area, and use the solution to get feature function, which are then integrated using Fourier-Mellin moment to represent the shape. This method develops the Poisson equation-geometric moment Descriptor proposed by Lena Gorelick, and keeps both advantages of Poisson equation-geometric moment and Fourier-Mellin moment. It is proved better than Poisson equation-geometric moment Descriptor in shape recognition and classification experiments.

• 한국정밀공학회지
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• 제23권8호
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• pp.89-99
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• 2006

In this paper a new shape reconstruction method that allows us to construct surface models from very large sets of points is presented. In this method the global domain of interest is divided into smaller domains where the problem can be solved locally. These local solutions of subdivided domains are blended together according to weighting coefficients to obtain a global solution using partition of unity function. The suggested approach gives us considerable flexibility in the choice of local shape functions which depend on the local shape complexity and desired accuracy. At each domain, a quadratic polynomial function is created that fits the points in the domain. If the approximation is not accurate enough, other higher order functions including cubic polynomial function and RBF(Radial Basis Function) are used. This adaptive selection of local shape functions offers robust and efficient solution to a great variety of shape reconstruction problems.

• 복식문화연구
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• 제19권3호
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• pp.449-459
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• 2011

The purpose of this study is investigate the feature of the body shape of obese males and to propose a new apparel sizing system considering the body size of obese men through an the analysis of the body measurement of obese men in their twenties as reported in the 'Fifth Korean National Physical Standard Reports'. For this study, a new apparel sizing system for casual wear was proposed for obese men in their twenties after a body measurement of 159 obese men in their 20s with a BMI of 25 and over as reported in the 'Fifth Korean National Physical Standard Reports' conducted by SIZEKOREA. This study sought to investigate the features of obese men's bodies by comparing the body shape between obese men and ordinary men. The result of shows that width, depth and circumference items influencing the width size when producing clothes are larger in the case of an obese body shape than an ordinary body shape, and that the stature, total length, arm length and outside leg length influencing the length size are similar between an obese body shape and an ordinary body shape. Therefore, it was confirmed that an apparel sizing system specializing in clothes for obese customers is required. As a result of this study of the features of body shape, the control dimensions for such an apparel sizing system were determined to be the stature and chest circumference of upper garments and the stature and waist circumference(omphalion) for lower garments. The interval between the sizes was 5cm for the stature and was irregular for the chest and waste circumference. Consequently, 8 sizes were proposed for upper garments and 9 sizes were proposed for lower garments.

• 정보처리학회논문지:소프트웨어 및 데이터공학
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• 제6권1호
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• pp.23-28
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• 2017

Shape from focus (SFF) 기법은 카메라 렌즈를 다양한 초점 거리로 놓고 촬영한 영상을 이용해 물체의 3차원 정보를 추출하는 방법이다. 이 논문에서는 미소 객체(microscopic object)의 3차원 깊이 정보를 추출하기 위해 수학적 모폴로지의 기울기 연산자를 이용하는 새로운 SFF방법을 제안한다. 전통적으로 SFF 기법에서는 초점의 품질을 측정하기 위해 하나의 초점 측도(focus measure)를 사용한다. 그러나 미소 객체의 복잡한 형태와 텍스쳐 특성에 따라 하나의 초점 측도만을 사용하는 것은 충분하지가 않은데, 본 논문에서는 향상된 초점 측도를 위해 다수의 형태소(multi-structuring elements)를 사용하는 모폴로지 연산자를 사용하는 방법을 제안한다. 최종적으로 모든 초점 측도 결과를 통합하여 최적의 깊이 맵을 계산하게 된다. 실험을 통해 제안된 알고리즘이 기존의 방법들에 비해 3차원 형상 복원 측면에서 더 정밀한 깊이 맵을 제공하는 것을 알 수 있었다.

• Wind and Structures
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• 제37권2호
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• pp.95-104
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• 2023

The latest revision of AS/NZS 1170.2 incorporates some new research and knowledge on strong winds, climate change, and shape factors for new structures of interest such as solar panels. Unlike most other jurisdictions, Australia and New Zealand covers a vast area of land, a latitude range from 11° to 47°S climatic zones from tropical to cold temperate, and virtually every type of extreme wind event. The latter includes gales from synoptic-scale depressions, severe convectively-driven downdrafts from thunderstorms, tropical cyclones, downslope winds, and tornadoes. All except tornadoes are now covered within AS/NZS 1170.2. The paper describes the main features of the 2021 edition with emphasis on the new content, including the changes in the regional boundaries, regional wind speeds, terrain-height, topographic and direction multipliers. A new 'climate change multiplier' has been included, and the gust and turbulence profiles for over-water winds have been revised. Amongst the changes to the provisions for shape factors, values are provided for ground-mounted solar panels, and new data are provided for curved roofs. New methods have been given for dynamic response factors for poles and masts, and advice given for acceleration calculations for high-rise buildings and other dynamically wind-sensitive structures.

• 한국의류학회지
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• 제32권4호
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• pp.598-607
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• 2008

Bast fibers were applied for various usages from fabrics to household care products long time ago. In this study, we investigated the physical characteristrus of water retted & chemically rotted fibers of Yucca, New Zealand hemp, Corn, Kuzu vine, Indian mallow, and Mulberry paper that have been harvested by domestic cultivation. Water retting is more effective than chemical rotting for six kinds of plant fibers. When all fibers were rotted chemically with 1% sodium hydroxide, only Kuzu vine and Indian mallow were retted. Indian mallow, Yucca, New Zealand hemp, and Com fibers have higher tensile strength than any other fibers. The crystallinity of Kuzu vine, Indian mallow, Yucca, New Zealand hemp, and Corn was as low as 60% but Yucca, New Zealand hemp were flexible. Yucca had fewer lumina whereas New Zealand hemp more lumina in cross sectional shape. Especially com fibers have a structure like sponge, and Indian mallow had a net shape. The longitudinal section of New Zealand hemp showed smooth and long shape. Mulberry paper was proved to be short and thin, which is quite appropriate for making paper. In this study, we found that plant fibers for living material could be used for cloth materials.

• 소성∙가공
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• 제18권4호
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• pp.283-289
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• 2009

The multi-stage shape drawing is used to obtain long shaped products with high levels of dimensional accuracy and quality. It is important to design the cross sectional shapes of the intermediate passes to meet the required dimensional accuracy of the final product in the multi-stage shape drawing. Until now, the cross sectional shapes of the intermediate passes have been designed by the experiences. It is still remained unsolved problem to design the cross sectional shapes of intermediate pass drawing dies in the multi-pass shape drawing. In this study, a new technique is proposed to design the cross sectional shapes of intermediate passes. The proposed method is applied to a multi-stage shape drawing for a LM-guide which is one of the representative shape drawing products. In order to verify the effectiveness of the proposed method, FE-simulation and experiments have been carried out. The dimensional accuracy of the proposed method is compared with that of the conventional shape drawing process designed by the industrial engineers.