• Title/Summary/Keyword: Surface Expansion

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An ergonomic Study on the function of Slacks -On the Expansion and Contraction of the Skin Surface of the Lower Body- (Slacks의 기능성에 관한 인간공학적 연구 -동하부 및 대퇴부의 신축을 중심으로-)

  • 함옥상
    • Journal of the Korean Home Economics Association
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    • v.19 no.2
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    • pp.151-163
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    • 1981
  • This study was to investigate the changes of shape of the surface square measurements, the rate, measurements of expansion and contraction and correlation. In this study was found the following: 1. According to the developmental illustration of the shell it was revealed that there was a great change in the thigh area of the body. When the leg was raised and the waist bent forward the front sections of the abdomen were contracted and the center back of the hip was expanded. 2. It was found that the contraction was present in the girth of the back section and front section was expanded in the rate of the body surface. In the length from the middle waist to hip the front area showed a great deal of contraction the back area of the hip & thigh revealed a great deal of expansion. 3. By the somatometry, the measurements of the expansion and contraction of the body surface, there was a great change in waist and hip. It revealed that the maximum expansions of waist and hip line in the chair were 1.8cm and 4.08cm respectively. Therefor, when slacks are made at least the amount of ease of 1.8cm of waist line and 4cm of hip line must be made and the allowance of the center back of hip area must be made. 4. It revealed that there was a correlation between waist and hip girth.

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A Study on the Mechanism of Arm Surface Changes for the development of Sleeve Drafting Standard (소매설계기준 개발을 위한 상지체표변화구조에 관한 연구)

  • 최해주
    • Journal of the Korean Society of Clothing and Textiles
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    • v.20 no.5
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    • pp.852-859
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    • 1996
  • The factors and mechanism of arm surface changes were analyzed by regression analysis for the relationship between changes in arm joint angle and arm surface changes, according to the direction of upper extremity motion. Body surface change patterns among subjects were tested also. Experiments were carried out on 3 female subjects of different body types to examine 26 motions in 4 directions for 4 upper extremity parts. The major conclusions of the study are as follows: 1. The expansion or contraction of arm surface length depends on the direction of upper extremity motion. 2. Arm surface length changes by linear expansion or contraction according to the joint angle of the direction of motion. The mechanism of arm surface changes is represented by a linear relation between arm surface changes and the (actors of the direction of upper extremity motion and arm joint angle. 3. Arm surface length shows the same pattern of body surface changes regardless of body type. A quantitative model of body surface changes at upper extremity should be developed for functional sleeve design.

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MAGNETIC HELICITY PUMPING BY TWISTED FLUX TUBE EXPANSION

  • CHAE JONGCHUL;MOON Y.-J.;RUST D. M.;WANG HAIMIN;GOODE PHILIP R.
    • Journal of The Korean Astronomical Society
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    • v.36 no.1
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    • pp.33-41
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    • 2003
  • Recent observations have shown that coronal magnetic fields in the northern (southern) hemisphere tend to have negative (positive) magnetic helicity. There has been controversy as to whether this hemispheric pattern is of surface or sub-surface origin. A number of studies have focused on clarifying the effect of the surface differential rotation on the change of magnetic helicity in the corona. Meanwhile, recent observational studies reported the existence of transient shear flows in active regions that can feed magnetic helicity to the corona at a much higher rate than the differential rotation does. Here we propose that such transient shear flows may be driven by the torque produced by either the axial or radial expansion of the coronal segment of a twisted flux tube that is rooted deeply below the surface. We have derived a simple relation between the coronal expansion parameter and the amount of helicity transferred via shear flows. To demonstrate our proposition, we have inspected Yohkoh soft X-ray images of NOAA 8668 in which strong shear flows were observed. As a result, we found that the expansion of magnetic fields really took place in the corona while transient shear flows were observed in the photosphere, and the amount of magnetic helicity change due to the transient shear flows is quantitatively consistent with the observed expansion of coronal magnetic fields. The transient shear flows hence may be understood as an observable manifestation of the pumping of magnetic helicity out of the interior portions of the field lines driven by the expansion of coronal parts as was originally proposed by Parker (1974).

An Ergonomic Study on the Function of the Basic Pattern of Clothing -On the Expansion and Contraction of the Skin Surface of the Upper Body- (의복 원형의 기능성에 관한 인간공학적 연구)

  • 함옥상
    • Journal of the Korean Home Economics Association
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    • v.17 no.4
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    • pp.1-14
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    • 1979
  • The functional problems of the basic pattern of clothing are a matter of the first importance to clothing construction. Therefore, the ergonomic analysis of the expansion and contraction of the upper body surface, due to motion, has become required. thus in order to obtain the measurements and rate of expansion and contraction of the upper body surface following from its motions, the development figure of " Shell" and somatometry were employed. The results obtained through the investigation can be summarized as follows : 1) According to the developmental figures of "Shell" the latitudes centering around the shoulder line present contractive tendencies by arm movement. The longitudes around the center back waist length are expansive tendencies when bent forward. In the case of a 15$^{\circ}$ lean backward posture, the longitudes around the center front waist length are expansive tendencies. 2) By somatometry, the region from the scapula to the axilla point the upper back with presents the greatest expansion (more than 30%). The region from scapla to arm presents the maximum rate of contraction. In considering the longitude , under the axilla waist length and the bust point waist length generally shows the greatest rate of expansion. 3) The bust point waist length and under the axilla waist length are of great importance to the basic pattern of clothing. and have expansive tendencies(6.3cm). Among the latitudes, the upper back width has the greatest tendency for expansion (7.83 cm). 4) The region which presents the greatest rate of the expansion and contraction is in the proximity of the arm. These results testify that the amount of room of the back width must be given consideration in constructing the basic pattern of clothing.pattern of clothing.

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Effect of the top coating surface tension and thermal expansion matching on the electrical properties of single-walled carbon nanotube network films (표면장력과 열팽창계수 불일치가 단일벽 탄소나노튜브 필름의 전도성에 미치는 영향 연구)

  • Kim, Jun-Suk;Han, Joong-Tark;Jeong, Hae-Deuk;Jeong, Hee-Jin;Jeong, Seung-Yol;Lee, Geon-Woong
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2010.03b
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    • pp.42-42
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    • 2010
  • We have characterized the previously undescribed parameters for engineering the electrical properties of single-walled carbon nanotube (SWCNT) films for technological applications. The surface tension of the top coating passivation material and matching coefficients of thermal expansion for the substrate and carbon nanotube network are two crucial parameters for the fabrication of reliable and highly conductive single-walled carbon nanotube network thin films.

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Effect of the top coating surface tension and thermal expansion matching on the electrical properties of single-walled carbon nanotube network films (표면장력과 열팽창계수 불일치가 단일벽 탄소나노튜브 필름의 전도성에 미치는 영향 연구)

  • Kim, Jun-Suk;Han, Joong-Tark;Jeong, Hee-Jin;Jeong, Seung-Yol;Lee, Geon-Woong
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2010.06a
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    • pp.278-278
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    • 2010
  • We have characterized the previously undescribed parameters for engineering the electrical properties of single-walled carbon nanotube (SWCNT) films for technological applications. The surface tension of the top coating passivation material and matching coefficients of thermal expansion for the substrate and carbon nanotube network are two crucial parameters for the fabrication of reliable and highly conductive single-walled carbon nanotube network thin films.

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Change of Thermal Environment with Urban Expansion (도시 확장에 따른 온열환경의 변화)

  • Kim, Sang-Jin
    • Journal of the Korean Solar Energy Society
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    • v.27 no.2
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    • pp.95-101
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    • 2007
  • The surface changes due to urban expansion and the increase of artificial heat releases have brought significant climate changes such as heat island phenomenon in urban area. Furthermore, these changes also have brought serious problems such as air temperature increase, wind changes, and air pollution in urban area. Comprehensive analytical technologies considering various effects are required to analyse complicated mechanism of climate changes, and review the efficient measures. In this research, the effect of the urban expansion in Tokyo and Bangkok area on urban environment will be discussed. By using CFD, urban development and the mechanism of global warming and wind change are studied in those two cities. As a result of numerical research, the surface changes of city could bring the environmental changes in urban area.

Expansion performance and mechanical properties of expansive grout under different curing pressures

  • Yiming Liu;Yicheng Ye;Nan Yao;Changzhao Chen
    • Geomechanics and Engineering
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    • v.33 no.4
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    • pp.327-339
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    • 2023
  • The expansion capacity and strength of expansive grout have a significant influence on the stress state of a supported rock mass and the strength of a grout-rock mass structure. The expansion and strength characteristics are vital in grouting preparation and application. To analyze the expansion performance and mechanical properties of expansive grout, uniaxial compressive strength (UCS) tests, expansion ratio tests, XRD, SEM, and microscopic scanning tests (MSTs) of expansive grout under different curing pressure conditions were conducted. The microevolution was analyzed by combining the failure characteristics, XRD patterns, SEM images, and surface morphologies of the specimens. The experimental results show that: (1) The final expansion ratio of the expansive grout was linear with increasing expansion agent content and nonlinear with increasing curing pressure. (2) The strength of the expansive grout was positively correlated with curing pressure and negatively correlated with expansion agent content. (3) The expansion of expansive grout was related mainly to the development of calcium hydroxide (Ca(OH)2) crystals. With an increase in expansion agent content, the final expansion ratio increased, but the expansion rate decreased. With an increase in the curing pressure, the grout expansion effect decreased significantly. (4) The proportion of the concave surfaces at the centre of the specimen cross-section reflected the specimen's porosity to a certain extent, which was linear with increasing expansion agent content and curing pressure.

Prediction of Impact Energy Absorption in a High Weight Drop Tester by Response Surface Methodology (반응표면법을 사용한 고 중량물 낙하시험기의 충격에너지 흡수량 예측 연구)

  • Kang, Hoon;Jang, Jin-Seok;Kim, Da-Hye;Kang, Ji-Heon;Yoo, Wan-Seok;Lee, Jae-Wook
    • Journal of the Korean Society of Manufacturing Process Engineers
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    • v.15 no.3
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    • pp.44-51
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    • 2016
  • This paper presents the characteristics of the energy absorption in an expansion tube type impact absorber that is applied to a high weight drop tester and the use of a response surface methodology to predict the impact energy absorption. In order to identify the characteristics of the energy absorption, a set of finite element analysis was conducted with Abaqus Explicit. Moreover, the ISCD-II sampling method and a first order polynomial were used to build a response surface. As a result, we demonstrated that the impact energy could be controlled by four main design variables, namely an expansion pipe's thickness, inner radius, pressing die's expansion angle and expansion ratio. Additionally, we observed the relationship between the four main design variables and the impact energy absorbing time, displacement, and maximum impact force.

Analysis of the Residual Stress due to Cold Expansion and Stress Intensity Factor in CT specimen Using Finite Element Method (유한요소법을 이용한 CT 시편의 홀확장 잔류응력 및 응력확대계수 해석)

  • Jang, Jae-Soon;Yang, Won-Ho;Kim, Cheol;Ko, Myung-Hoon;Cho, Myoung-Rae
    • Proceedings of the KSME Conference
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    • 2001.06a
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    • pp.603-608
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    • 2001
  • Recently, cold expansion of fastener holes is commonly used in the aerospace industry to increase the fatigue endurance of airframes. Cold expansion process is used as the retardation of crack initiation in the hole. This treatment leads to an improvement of fatigue behavior due to the compressive residual stresses developed on the hole surface. The residual stress profile depends on the cold expansion ratio. In the present paper, it is shown that residual stress is redistributed due to the application of cold expansion process for CT specimen. It is further shown that residual stress increases in proportion to cold expansion ratio. It is thought that crack growth rate increases as cold expansion ratio.

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