• Title/Summary/Keyword: Back-surface shape

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The Morphological Characteristics of Morus tiliaefolia Makino Growing Wild in the Korean Peninsula (한반도에 자생하는 돌뽕나무(Morus tiliaefolia Makino)의 형태학적 특성)

  • 박광준
    • Journal of Sericultural and Entomological Science
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    • v.44 no.1
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    • pp.13-18
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    • 2002
  • The morphorogical characteristics of the Morus tiliaefolia growing wild in the Korean peninsula are as follows. The chromosome number of somatic cell is 2n=84,that is hexaploid. The shape of male inflorescence is a long cylinder shape of 3.6∼6.0 cm. The length of female inflorescence is 1.8 cm, red violet or violet and the weight of mulberry fruits is 1.39∼1.65 g. The winter bud is very big in comparison with the branch and the accessory bud does not exist. The leaf is big and lobed leaf or entire leaf, the density of lenticell is 9.42$\pm$1.29 ㎠. The length of leaf trichome is 236∼438 ㎛ and the distribution density is 16∼37/25 ㎟ and heigh density of leaf back. The trichome shape of the leaf surface is cylinder shaped, in the leaf back it is thin and long corn shaped.

A Study on CFD of Turbo fan and Fabrication of Turbo Fan with Honeycombs by PBF (터보 팬의 유동해석 및 허니콤 구조가 적용된 터보 팬의 PBF 3D 프린팅 제작에 관한 연구)

  • Jin, Chul-Kyu;Lee, Haesoo;Lee, Un-Gil;Woo, Jae-Hyeog
    • Journal of the Korean Society of Industry Convergence
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    • v.25 no.5
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    • pp.899-908
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    • 2022
  • In this study, a study was conducted to localize a large aluminum turbo fan used for tank powerpack. The turbo fan was scanned with a 3D scanner and then 3D modeling was performed. Computational fluid dynamics (CFD) were performed from the performance conditions of the fan, and structural analysis was performed using the pressure data obtained from CFD. The fan was reduced to 1/5 size by applying the geometric similarity. A 1/5 size fan has a honeycomb structure inserted into the front shroud and back shroud to reduce the weight by 5.3%. A 1/5 size fan was printed using a PBF 3D printer, and a 1/5 size fan with honeycombs was also printed. The pressure drop of 8.67 kPa and the required power of 138.19 kW, which satisfies the performance conditions of the fan, were confirmed from the results of CFD. The values of the maximum deformation amount of 0.000788 mm and the maximum effective stress of 0.241 MPa were confirmed from the structural analysis results. The fan printed by the PBF 3D printer had the same shape as the modeling, and the shape was perfect. There are no defects anywhere in appearance. However, the condition of the outer surface of the fan's back shroud is rough compared to other locations. The fan in which the honeycomb was inserted was also perfectly output, and the shape of the honeycomb was the same as the modeling.

Development of tight-fit torso patterns for adult males somatotype 20s~40s using 3D somatic surface shape (3D체표면 입체형상을 활용한 20~40대 성인남성의 체형유형별 타이트 핏 토르소원형 설계)

  • Hong, Eun-Hee
    • The Research Journal of the Costume Culture
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    • v.29 no.6
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    • pp.904-921
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    • 2021
  • The aim of this study was to develop a body type suitable for adult men aged from their 20s to their 40s and to present a method of drafting related patterns. To this end, the somatic surface pattern data from previous studies were used. The research method involved drafting torso patterns for each type by setting and distributing the ease to the somatic surface pattern. Appearance evaluation was performed with virtual clothing. Then, the torso pattern for each body type was completed and presented as a draft method. SPSS was used for data analysis in this study. The research results are as follows. Types 1, 2, and 3 were set to 7%, 6%, 5%; 7%, 6%, 4%; and 6.5%, 7%, and 6% for chest, waist, and hip circumference measurements, respectively. The ratio of front to back was 50%:50%, 50%:50%, and 50%:50% of the spare for each body part for Type 1; 70%:30%, 50%:50%, and 60%:40% for Type 2, and 60%:40%, 70%:30%, and 60%:40% for Type 3. A tight-fit torso pattern for each body type suitable for adult males in their 20s to 40s was drafted, which was modified and supplemented through the evaluation of the first and second virtual wear. Considering the practicality of this approach, for generalization of the patterns, the items of the pattern were converted into a drafting method and presented as a draft method.

Surface Mounted Permanent Magnet Synchronous Motor Design for Torque Ripple Reduction in EPS (EPS용 표면부착형 영구자석 동기전동기의 토크 리플 저감)

  • Lim, Seung-Bin;Park, Hyun-Jong;Kang, Dong-Woo;Ham, Sang-Hwan;Lee, Ju
    • Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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    • v.24 no.8
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    • pp.27-31
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    • 2010
  • Torque ripple of the motor used in EPS raises vibration problem on steering system. To solve this problem, this paper proposes a optimum design for torque ripple reduction of Surface-mounted Permanent Magnet Synchronous Motor(SPMSM) in EPS. Through analyis back-EMF using Finite element method as changing the shape of permanent magnet and stator shoe, we presented the method of torque ripple redution.

Somatotype of Women's Upper Body in their thirties through a Development Figure of the Surface of the Body (체표면 전개도에 의한 30대 여자 상반신의 유형분석)

  • 최은주
    • Journal of the Korean Society of Clothing and Textiles
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    • v.22 no.2
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    • pp.203-214
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    • 1998
  • The purpose of this study is to classify the upper body of women into several kinds of somatotypes, using the method of Surgical Tape and making their shells. The subjects are 53 females 30 to 39 years-old. Fifty-three anthropometric data are measured per shell of bodysurface; six somatotype factors are obtained through principal component analysis and orthogonal rotation by the method of Varimax, Somatotype of women's upper body is achieved by cluster analysis, using the standardized factor score as an independent variable and the FASTCLUS of SAS by Kmeans. The results are as follows: 1. The number of the factors which explain the somatotype is six and those factors comprise 76.12 percent of total variance. Factor 1: related to the size of shape in the front of upper body Factor S: related to the size of shape in the back of upper body Factor 3: related to the type of the upper chest over the chest circumference line Factor 4: related to the length of·the upper body Factor 5: related to the part of the neck Factor 6: related to the type of the lower chest under the chest circumference line 2. Cluster analysis results in classification of upper body into five clusters. Cluster L: the length is the largest and the circumference is small. The part of waist is the largest and widest among surface areas. Cluster 2: Slender body line from chest to waist is characteristic. The length is longer. The part of upper and lower chest is larger among surface areas. Cluster S: the circumference is the smallest and armhole is small. The length and surface area are small. Cluster 4: the circumference and armhole is the largest. The length is the smallest. Cluster 5: the circumference is average and the length is a little long. The body line(silhouette) from chest to waist is curved slightly.

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A Study on the Variation of the Skin Surface According to Arm Movement by $Moir\'{e}$ Photography Method -In the area of uppearm and shoulder blade- ($Moir\'{e}$ Photography법에 의한 동작시 체표면 형태 변화에 관한 연구 -상지 및 견갑골 부위를 중심으로-)

  • Kim Haekyung;Cho Jungmee;Suh Chuyeon
    • Journal of the Korean Society of Clothing and Textiles
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    • v.14 no.4 s.36
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    • pp.292-304
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    • 1990
  • The surface change of upperarm and shoulder blade area are caused by the extensive upper limb movement, thus it is necessary to measure the amount of change for constructing the clothing. Moire photography was taken after plastic casters of upperarm and shoulder blade area was prepared. 1. For the shoulder blade area, subjects showed the same change of surface area for the various limb positions, wherease, for the upperarm only at the $0^{\circ}\;and\;180^{\circ}$ limb position, same change was observed. 2. As the movement of the upperarm was increased, surface area of axillary part was increased and that of shoulder part was decreased. 3. To make a bodice pattern, the minimum size of the back with the ease were $\frac{B}{4}$+3.13 cm R for normal wear and $\frac{B}{4}$+5.75 cm for active wear. 4. As the movement of the arm was increased, the cross section for the upperarm were changed to elliptical shape. 5. For each horizontal basic line, there was a positive correlation between the amount of change of shoulder blad area and that of upperarm area.

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Surface Roughness Discrimination with Whisker Tactile Sensors Modeling Rodent Whiskers (쥐 수염을 모델로 하는 수염 촉각 센서의 물체 표면 거칠기 구별에 관한 연구)

  • Baek, Seung-Hun;Kim, Dae-Eun
    • Journal of the Institute of Electronics Engineers of Korea SC
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    • v.47 no.4
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    • pp.55-60
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    • 2010
  • Rodents can recognize objects by using their whiskers. Not only rodents but also mammals use their whiskers to recognize objects. However, rodents can discriminate surface roughness in micrometer resolution throughout their whisker sensing. Rats can distinguish an target object's shape, roughness and surface pattern by moving their whisker back and forth freely. Mechanoreceptors surrounding the whisker in their follicle measure deflection and vibration of the whisker. In this paper, we designed biomimetic whiskers modeling rodent whiskers and showed the characteristic properties to extract the information of surface roughness.

The Study on the Lower Limb Surface Changes Caused by the Limb Movements (Part 1) (동작에 따른 하지피부면의 변화에 관한 연구 (제일보) - 탈관절과 슬관절 굴신을 중심으로 -)

  • 박영득
    • Journal of the Korean Home Economics Association
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    • v.20 no.4
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    • pp.1-12
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    • 1982
  • This study was to investigate the changes of shape of the lower limb surface, the rate of the measurement of expansion and contraction and correlation coefficient between variables caused by hip joint and knee joint movements. The results of the investigation are as follows; 1. According to the development figure of shell when the leg was raised $45^{\circ}$forward($M_{2}$), total length of F.L shortened while B.L lengthened. This result is contarary to $M_{3}$raising the leg $15^{\circ}$ backward. In both $M_{2}$, $M_{3}$movements, the rate of expansion and contraction to the course direction was insignificant. When hip joint was bent $15^{\circ}$ with knee joint $120^{\circ}$bent ($M_{4}$) and hip joint was bent $30^{\circ}$ with knee joint $90^{\circ}$ bent($M_{5}$), upper section of back hip expanded while the front hip section contracted slightly. In the Movement of sitting on the chair($M_{6}$), abdomen, front hip section and upper thight section contracted to the wale direction remarkably while the back hip section expanded conspicuously. 2. According to the rate of expansion and contraction of skin (surface) by the somatometry. In $M_{2}$, C.F.L. upper and middle thight girth contracted and B.L, C.L, L.L expanded. This fact is contarary to M3. In M4, M5, C.F.L showed remarkable contraction and C.B.L expanded remarkably. In $M_{6}$, C.B.L contracted most of all the items measured and knee girth, F.L, L.L, C.B.L, hip girth expanded conspicuously. 3. According to the correlation coefficient between variables. In various movements, the correlation among girth items commonly showed a high or middle grade, the correlation among length items also commonly showed a low grade and that girth and length items showed a very low grade commonly. Waist girth, hip grith, F.L, B.L, L.L items showed that there were significant correlation.

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Variation of Cone Crack Shape in Ceramic Materials According to Spherical Impact Velocity (입자충격속도에 따른 세라믹재료의 콘크랙 형상 변화)

  • O, Sang-Yeop;Sin, Hyeong-Seop;Seo, Chang-Min
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.26 no.2
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    • pp.380-386
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    • 2002
  • Damage behaviors induced in silicon carbide by an impact of particle having different material and size were investigated. Especially, the influence of the impact velocity of particle on the cone crack shape developed was mainly discussed. The damage induced by spherical impact was different depending on the material and size of particles. Ring cracks on the surface of specimen were multiplied by increasing the impact velocity of particle. The steel particle impact produced larger ring cracks than that of SiC particle. In the case of high velocity impact of SiC particle, radial cracks were produced due to the inelastic deformation at the impact site. In the case of the larger particle impact, the damage morphology developed was similar to the case of smaller particle one, but a percussion cone was farmed from the back surface of specimen when the impact velocity exceeded a critical value. The zenithal angle of cone cracks developed into SiC material decreased monotonically with increasing of the particle impact velocity. The size and material of particle influenced more or less on the extent of cone crack shape. An empirical equation, $\theta$= $\theta$$\sub$st/, v$\sub$p/(90-$\theta$$\sub$st/)/500 R$\^$0.3/($\rho$$_1$/$\rho$$_2$)$\^$$\frac{1}{2}$/, was obtained as a function of impact velocity of the particle, based on the quasi-static zenithal angle of cone crack. It is expected that the empirical equation will be helpful to the computational simulation of residual strength in ceramic components damaged by the particle impact.

Belt Pattern Making for Hip-hugger garment using 3D Body Scan Data (3차원 인체 스캔 데이터를 활용한 Hip-hugger 의류용 벨트 패턴 설계)

  • Park, Soon-Jee;Choi, Sin-Ae
    • Fashion & Textile Research Journal
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    • v.10 no.5
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    • pp.652-659
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    • 2008
  • This study was designed to testify the possibility and devise the method to manipulate the 3D body scan data to produce rounded-belt pattern adaptable to hip-type variation of women in their 20's. The results of this research were as follows : Firstly, based on drop-value distribution of hip and waist girth, 151 subjects were classified into three hip-types; Type 1 (15.23%) was 'cylinder type', showing lowest drop-value, Type 2 (69.54%) was 'average type' and Type3 (15.23%) was 'hourglass type' showing highest drop-value. Secondly, using CAD program, design lines for round shape belt were set on the surface of 3D scan data of representative subject of each type. And divided 3D surfaces were flattened onto the plane by the internal tools of CAD program. The measure, 'lifting value of round belt pattern', implying the level of curve ratio of pattern was higher in back than front. This result might be linked to the fact that the hip part is more protruded than the abdomen part. And the measures also showed highest values in Type 3(hourglass type) and lowest in Type 1(cylinder type), meaning that the pattern of Type 3 showed more rounded shape than that of Type 1. This finding implied that round belt for body type having high drop-value should be shaped more curved. Thirdly, difference ratios of outline length and area between 3D curves(body surface) and 2D plane(pattern) were 4.5% and 1.3%, respectively. This result demonstrated and solidified the feasibility of designing digital garment pattern from 3D body scan data.