• Title/Summary/Keyword: Physical shape

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Rapid Manufacturing of 3D Prototype from 3D scan data using VLM-ST (단속형 가변적층쾌속조형공정을 이용한 3차원 스캔데이터로부터 3차원 시작품의 쾌속 제작)

  • 이상호;안동규;김효찬;양동열;박두섭;채희창
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 2002.05a
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    • pp.536-539
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    • 2002
  • The reverse engineering (RE) technology can quickly generate 3D point cloud data of an object by capturing the surface of a model using a 3D scanner. In the rapid prototyping (RP) technology, prototypes are rapidly produced from 3D CAD models in a layer-by-layer additive basis. In this paper, a physical human head shape is duplicated using a new RP process, the Transfer-type Variable Lamination Manufacturing process using expandable polystyrene foam sheet (VLM-ST), after the point cloud data of a human head shape measured from 3D SNX scanner are converted to STL file. From the duplicated human head shape, it has been shown that the VLM-ST process in connection with the 3D scanner is a fast and efficient process in that shapes with free surface, such as the human head shape, can be duplicated with ease. Considering the measurement time and the shape duplication time, the use of 3D SNX scanner and the VLM-ST process is expected to reduce the lead-time fur the development of new products in comparison with the other existing RE-RP connected manufacturing systems.

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A Study on Classification of Chinese Women - Focusing on the Body Index - (북경(北京)과 상해(上海에)에 거주하는 중국(中國) 성인여성(成人女性)의 체형 유형화(體形 類型化)에 관한 연구(硏究) -지수(指數)를 중심(中心)으로-)

  • Kim, Eun-Hee;Sohn, Hee-Soon
    • Journal of Fashion Business
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    • v.11 no.5
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    • pp.124-135
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    • 2007
  • To understand tendency of body shapes of Chinese women who reside in Beijing and Shanghai for improving the match of exported clothes to China, this categorizes the bodies by extracting the elements of the objects and understanding body promotion. To categorize the subject by not size factor but form factor, data were compared and analyzed mainly with index based on measurement of the body. This selected specimen as 1381 of Chinese women from 19 to 50 selected in random sampling in Shanghai and Beijing from 23th, June to 7th August in 2004. 1. Chinese women is generally separated in 7.09 parts and upper body including waist shapes round. 2. The elements indicating the women's physical properties are obesity, the size of upper part, front shape, side shape, shoulder and back shape, perpendicular size and lower part length, body shape. 3. The Chinese are categorized by three factors. Normal shape which is not both fat and skinny, records the highest in the ranking.

Effect of Heat Flux on the Melting Efficiency and Penetration Shape in TIG Welding (TIG 용접에서 열유속이 용융효율과 용입형상에 미치는 영향)

  • Oh, Dong-Soo;Cho, Sang-Myung
    • Journal of Welding and Joining
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    • v.27 no.2
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    • pp.44-50
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    • 2009
  • The characteristics of arc pressure, current density and heat flux distribution are important factors in understanding physical arc phenomena, which will have a marked effect on the penetration, size and shape of a weld in TIG welding. The purpose of this study is to find out the effect of the heat flux on the melting efficiency and penetration shape in TIG welding using the results of the previous investigators. The conclusions obtained permit to draw a proper method which derived the heat flux distributions by arc pressure distribution measurements, but previous researchers calculated heat flux and current distribution with the heat intensity measurements by the calorimetry. Heat flux of Ar gas arc was concentrated at the central part and distributed low from the arc axis to the radial direction, that of He mixing arc was lower than that of Ar gas, and it was wide distributed to radial direction. That showed a similar characteristic with the Nestor's by calorimetry calculated values. Throughout heat flux drawn in this study was discussed melting efficiency and penetration shape on Ar gas and He mixing gas arc.

Simulating the influence of pore shape on the Brazilian tensile strength of concrete specimens using PFC2D

  • Haeri, Hadi;Sarfarazi, Vahab;Zhu, Zheming;Marji, Mohammad Fatehi
    • Computers and Concrete
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    • v.22 no.5
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    • pp.469-479
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    • 2018
  • The Brazilian tensile strength of concrete samples is a key parameter in fracture mechanics since it may significantly change the quality of concrete materials and their mechanical behaviors. It is well known that porosity is one of the most often used physical indices to predict concrete mechanical properties. In the present work the influence of porosity shape on concrete tensile strength characteristics is studied, using a bonded particle model. Firstly numerical model was calibrated by Brazilian experimental results and uniaxial test out puts. Secondly, Brazilian models consisting various pore shapes were simulated and numerically tested at a constant speed of 0.016 mm/s. The results show that pore shape has important effects on the failure pattern. It is shown that the pore shape may play an important role in the cracks initiation and propagation during the loading process which in turn influence on the tensile strength of the concrete samples. It has also been shown that the pore size mainly affects the ratio of uniaxial compressive strength to that of the tensile one in the simulated material samples.

Generation of Unit Shape Layer on CAD/CAM System for VLM-ST (VLM-ST용 CAD/CAM 시스템에서 단위 형상층 생성 방법 및 적용예)

  • 이상호;안동규;최홍석;양동열;문영복;채희창
    • Korean Journal of Computational Design and Engineering
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    • v.7 no.3
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    • pp.148-156
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    • 2002
  • Most Rapid Prototyping (RP) processes adopt a solid Computer Aided Design (CAD) model, which will be sliced into thin layers of constant thickness in the building direction. Each cross-sectional layer is successively deposited and, simultaneously, bonded onto the previous layer; and eventually the stacked layers from a physical part of the model. A new RP process, the transfer-type Variable Lamination Manufacturing process using expandable polystyrene foam sheet (VLM-ST), has been developed to reduce building time and to improve the surface finish of parts with the thick layers and a sloping surface. This paper describes the generation of Unit Shape Layer (USL), the cutting path data of the linen. hotwire cutter for the VLM-ST process. USL is a three-dimensional layer with a thickness of more than 1 mm and a side slope, and it is the basic unit of cutting and building in the VLM-ST process. USL includes data such as layer thickness, positional coordinates, side angles of each layer, hotwire cutting speed, the heat input to the hotwire, and reference shape. The procedure of generating USL is as follows: (1)Generation of the mid-slice from the CAD model, (2)Conversion of the mid-slice into a simply connected domain, (3)Generation to the reference shape for the mid-slice, (4)Calculation of the rotation angle of the hotwire of the cutting system.

A Study on the Use of 3D Human Body Surface Shape Scan Data for Apparel Pattern Making (의류 패턴 설계를 위한 삼차원 인체 체표면 스캔 데이터 활용에 관한 연구)

  • 천종숙;서동애;이관석
    • The Research Journal of the Costume Culture
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    • v.10 no.6
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    • pp.709-717
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    • 2002
  • In the apparel industry, the technology has been advanced rapidly. The use of 3D scanning systems fur the capture and measurement of human body is becoming common place. Three dimensional digital image can be used for design, inspection, reproduction of physical objects. The purpose of this study is to develop a method that drafts men's basic bodice pattern from scanned 3D body surface shape data. In order to pursue this purpose the researchers developed pattern drafting algorithm. The 3D scanner used in this study was Cyberware Whole Body Scanner WB-4. The bodice pattern drafting algorithm from 3D body surface shape data developed in this study is as follows. First, convert geometric 3D body surface data to 3D polygonal mesh data. Second, develop algorithm to lay out 3D polygonal patches onto a plane using Auto Lisp program. The polygon meshes are coplanar, and the individual mesh is continuously in contact with next one The bodice front surface shape data in polygonal patches form was lined up in bust and waist levels. The back bodice was drafted by lining up the polygonal mesh in scapula, chest, and waist levels. in the drafts, gaps between polygons were formed into the darts.

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A Pilot Study of the Effects of an 8-week School-Based Weight Loss Program on Obesity, Shape Satisfaction, and Shape Esteem in Obese Children (비만 아동에서 8주간의 학교 체중 조절 프로그램 실시 후 비만도, 체형 만족도 및 체형 존중감 변화에 대한 예비연구)

  • Nam, Jung-He;Kim, Soo-Kyung;Kim, Hyun-Jung
    • The Korean Journal of Food And Nutrition
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    • v.22 no.2
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    • pp.286-292
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    • 2009
  • This study was conducted to examine the effects of an 8-week weight loss program, on body composition, body shape satisfaction, body shape esteem in 15 obese children. This program included nutritional education and regular physical fitness. After completion of this program, height and body weight increased slightly but body compositions changed. BMI, degree of obesity, and body fat levels dropped slightly, however these differences were not significant. After the 8-week program body weight increased from $63.61{\pm}8.80\;kg$ to $64.07{\pm}9.11\;kg$, degree of obesity and BMI decreased from $151.73{\pm}13.62%$, and $29.08{\pm}2.35$ to $146.60{\pm}12.92%$, and $28.57{\pm}2.26$, respectively, and the percentage of body fat decreased slightly from $42.70{\pm}4.87%$ to $41.46{\pm}4.88%$. There were slight changes in weight of body muscle and lean body mass from $19.62{\pm}3.48\;kg$ and $36.17{\pm}5.78\;kg$ to $20.30{\pm}3.64\;kg$ and $37.16{\pm}6.18\;kg$, respectively. LBM and amount of muscle were higher after this weight loss program. The body shape esteem score increased from $7.60{\pm}4.01$ to $9.00{\pm}6.20$. There was no significant difference in body shape satisfaction before and after the program, and the participants also wanted to be leaner. Finally, body weight, BMI, and body fat showed negative correlations to body shape esteem.

Estimation of Single Vegetation Volume Using 3D Point Cloud-based Alpha Shape and Voxel (3차원 포인트 클라우드 기반 Alpha Shape와 Voxel을 활용한 단일 식생 부피 산정)

  • Jang, Eun-kyung;Ahn, Myeonghui
    • Ecology and Resilient Infrastructure
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    • v.8 no.4
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    • pp.204-211
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    • 2021
  • In this study, information on vegetation was collected using a point cloud through a 3-D Terrestrial Lidar Scanner, and the physical shape was analyzed by reconfiguring the object based on the refined data. Each filtering step of the raw data was optimized, and the reference volume and the estimated results using the Alpha Shape and Voxel techniques were compared. As a result of the analysis, when the volume was calculated by applying the Alpha Shape, it was overestimated than reference volume regardless of data filtering. In addition, the Voxel method to be the most similar to the reference volume after the 8th filtering, and as the filtering proceeded, it was underestimated. Therefore, when re-implementing an object using a point cloud, internal voids due to the complex shape of the target object must be considered, and it is necessary to pay attention to the filtering process for optimal data analyzed in the filtering process.

Analysis of the Changes in Lower Body Measurements and Shapes of Women in Their 20s for Slacks Pattern Development (슬랙스 패턴개발을 위한 20대 여성의 하반신 주요 부위별 치수 및 체형 변화 분석)

  • Kim, Jimin;Um, Sohee;Lee, Youngsook;Kim, Yongmun;Woo, Hyunri
    • Journal of Fashion Business
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    • v.26 no.1
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    • pp.30-40
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    • 2022
  • This study aims to provide basic information on the changes in lower body measurements and shapes of women in their 20s for developing better fitting slacks patterns and a more applicable sizing system that can be widely utilized for women of all ages. Factor and cluster analysis were performed on 1,360 women's direct measurement data within the age group from the 5th (2004) and 7th (2015) Korean Human Body Measurement Investigation. The factor analysis identified four factors and explained 82.54% of the total variance; Factor 1, horizontal measurements of lower body; Factor 2, vertical lengths of lower body; Factor 3, measurements of leg and hip areas; Factor 4, lengths of hip and crotch areas. The cluster analysis categorized the lower body shapes of each age group into four shapes; Shape 1, a petite lower body with short legs; Shape 2, a long lower body with medium built; Shape 3, an obese abdomen and legs; Shape 4, a short and slim lower body. Shape 4 (36.5%), Shape 2 (31.2%), Shape 1 (27.8%), and Shape 3 (4.5%) were placed in the order of frequency from the highest to lowest among all the age groups. The findings of this study showed gradual changes in the lower body measurements and shapes of women in their 20s and relevant physical features of each age group. They can be utilized for developing women's slacks patterns with better fitting and more comfort.

A Cohort Study of Physical Activity and All Cause Mortality in Middle-aged Men in Seoul (서울시 중년남성에서 육체적 활동량이 총 사망률에 미치는 영향에 관한 코호트 연구)

  • Kim, Dae-Sung;Koo, Hye-Won;Kim, Dong-Hyon;Bae, Jong-Myon;Shin, Myung-Hee;Lee, Moo-Song;Lee, Chung-Min;Ahn, Yoon-Ok
    • Journal of Preventive Medicine and Public Health
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    • v.31 no.4 s.63
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    • pp.604-615
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    • 1998
  • Although previous studies revealed the association of physical activity with mortality rate, it is unclear whether there is a linear trend between physical activity and mortality rate. In this study, the association of physical activity with the risk of all-cause mortality was analysed using Cox's proportional hazard model for a cohort of 14,204 healthy Korean men aged 40-59 years followed up for 4 years(Jan. 1993-Dec. 1996). Physical activity and other life style were surveyed by a postal questionnaire in December 1992. Total of 14,204 subjects were grouped into quartiles by physical activity. Using death certificate data, 123 deaths were identified. The second most active quartile had a lowest mortality .ate with relative risk of 0.44(95% C.I. : 0.23-0.84) compared with most sedentary quartile, showing a J-shape pattern of physical activity-mortality curve. By examining the difference in proportion of cause of the death between most active quartile and the other quartiles, there was no significant difference of proportional mortality from cardiovascular deaths, cerebrovascular deaths or deaths from trauma. The covariates were stratified into two group between which the trend of RR was compared to test the effect modification. There was no remarkable effect modification by alcohol intake, smoking, body mass index, calorie consumption, percent fat consumption. In conclusion, moderate activity was found to have more protective effect on all-cause mortality than vigorous activity and that the J-shape pattern of physical activity-mortality curve was not due to the difference of mortality pattern or effect modification by alcohol intake, smoking, body mass index, calorie consumption and percent fat consumption.

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