• Title/Summary/Keyword: Front to back ratio

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An Experimental Study on the Inclined Earth Retaining Structure in Clay (점토지반내의 IER 지주식 흙막이의 실험적 고찰)

  • Jeong, Dong-Uk;Im, Jong-Chul;Yoo, Jae-Won;Seo, Min-Su;Koo, Young-Mo;Kim, Sung-Jin
    • Journal of the Korean Geotechnical Society
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    • v.29 no.6
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    • pp.63-75
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    • 2013
  • Inclined Earth Retaining Structure Method (IER Method), was developed in order to improve the mechanical properties of the existing earth retaining method. IER consists of two supports, which are front and back supports. In the IER method, back support is very effective for the reduction of the earth pressure acting on the front support. In this study, the effects of back support and fixing conditions of lower ends of supports are analysed by laboratory model tests in clay. The test results show that back support reduces the Leteral displacement of IER effectively, and according to the results the effect of interval and fixing condition of back support was analysed.

A Study of Beam Tilted Antenna by Aperture Coupled Microstrip Array (개구 급전 마이크로스트립 배열에 의한 빔 틸팅 안테나에 관한 연구)

  • 고진현;하재권;박덕규
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • 1999.11a
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    • pp.151-155
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    • 1999
  • We proposed the beam tilted antenna by aperture coupled microstrip array, found out the values of design parameters by using Ensemble 5.1 of Ansoft Co., and analysed the performance of fabricated antenna. In order to point to the fixed satellite on the nothern hemisphere, 3 dB beamwidth of this antenna is 25$^{\circ}C$ to 65$^{\circ}C$. Operation bandwidth is 2.51GHz to 2.59GHz. The structure of this antenna is composed by 3 types of squared patches; reflector, driver, and director. The maximum antenna gain is 6.2dB at 2.56GHz and elevation angle of 42$^{\circ}C$. Front-to-Back ratio is more than 13dB at the same condition.

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Ergonomic Differences between Baby Carriers by Certain Wearing Positions

  • Cho, Sunghak;Kim, Chihwan
    • Journal of International Academy of Physical Therapy Research
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    • v.10 no.2
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    • pp.1774-1778
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    • 2019
  • Background : Methods of wearing a baby carrier have suggested; however, there have been no studies suggesting ideal ways. Objective : To investigate muscular fatigue and balance of the waist during baby carrier are worn on the front, the side, and the back of the body. Design: Randomized controlled clinical trial (single blind) Methods : The subjects of this study were 20 healthy men and women in their 20s, who underwent tests of muscular fatigue and balance of the waist bones based on types of wearing baby carrier. Electromyogram (EMG) patches were attached to the L2 and the L4 for testing muscular fatigue, while a device for measuring proprioceptive senses was used to assess balance ability. The measurements were performed before wearing the baby carrier and after 30 minutes of normal walking. The methods of wearing the baby carrier included wearing on the front, the side, and the back of the body. Results : The time taken to adjust the balance was shorter than other types of wearing during the baby carrier were worn on the side, and the ratio of lumbar flexion and relaxation was shown insignificant. Conclusions : These results suggested that wearing the carriers on the side was most effective on reducing fatigue and enhancing balance ability of the waist.

A study on the improvement of seamless knitwear neck design - Focused on the methods of knitting on the V-neck part of pullovers - (무봉제 니트웨어의 네크디자인 향상을 위한 연구 - V-네크 풀오버의 네크단 편성방법을 중심으로 -)

  • Ki, Hee-Sook
    • Journal of the Korea Fashion and Costume Design Association
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    • v.21 no.4
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    • pp.69-79
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    • 2019
  • This study aims to seek knitting methods that can enhance the neck design of seamless knitwear and to find out how to improve the designs by comparing and analyzing the characteristics of the knitting methods used for v-neck pullovers. The investigator analyzed the characteristics of the knitting methods and assessed the wearing sensation by using six different pieces of clothing for the experiment. The results were analyzed based on a variance analysis (ANOVA). Among the items showing significant results, the Duncan-test was used for more intensive research. As a result, while using the basic pattern of knitting methods, Experiment Clothes A ended up binding on the back neckline, and not making the hem of back. Also, the neck was the widest. In the case of the special neck, Experimental Clothes B (1:1), which had the least number of the knitting course in relation to the knitting ratio, the bottom part of the back body had the most wrinkles. According to the result of wearing sensation, the front part, the side part, and the back part showed similar results (p<0.000) in all items. Specifically, the appearance of the Experiment Clothes A (normal) in both the front and rear aspects were evaluated as the best. In the case of the special neck, the Experimental Clothes F was ranked the highest, whereas the Experimental Clothes B (1:1) was ranked the lowest. Based on the results of the study, it seems possible to provide concrete and technical data for the planning of unique and productive designs. With regard to seamless knitwear neck designs, a comparative analysis of the knitting method of v-neck pullovers will be of practical use in the development and manufacturing of the product.

A Study on Split Grading Methods for Women's Pants and Increase Rate of Body Size of Adult Women (성인 여성의 연령대별 인체 부위 간 치수증감률을 반영한 바지 그레이딩에 관한 연구)

  • Baek, Rise;Song, Hwa Kyung
    • Journal of the Korean Society of Clothing and Textiles
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    • v.43 no.6
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    • pp.877-890
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    • 2019
  • This study investigated the location of grading lines and grading amount defined by 17 women's wear brands for a pants item by target age groups (20-30, 30-40, and 40-50). This study utilized 6th Size Korea data and a script-based on a 3D scan measurement program to analyze the increase rate of body size in order to suggest a grading deviation distribution ratio for the pants using regression analysis. This study found that most brands appropriately divided grading amount at front thigh girth and back hip girth into the side and center by 1:1. Most brands divided the grading amount at the front hip girth into the side and center by 1:1; however, the ratio found from Size Korea is 0.8:1.2 for the 20-30 age group, 0.7:1.3 for the 30-40 age group, and 0.6:1.4 for the 40-50 age group. Regarding the back thigh girth, the brands targeting 20-30s, 30-40s, and 40-50s respectively assigned the grading amount into the side and center by 1:1, 1:1.2, and 1:1.3. However, the ratio found from Size Korea is 1.4:0.6 for the 20-30 age group, 1.7:0.3 for the 30-40 age group, and 1.3:0.7 for the 40-50 age group. The results can be utilized in improving the grading system of the pants item.

Investigation of Sound Absorbing Characteristics of the Railway Noise Barrier by Changing the Configuration of the Front Perforated Panel and Absorbing Material (철도 방음벽의 전면 타공과 흡음재에 의한 흡음성능 고찰)

  • Kim, Kwanju;Kim, Sanghun;Park, Jinkyu
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2013.10a
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    • pp.575-580
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    • 2013
  • This study focused on the identification of sound characteristics according to the configuration of sound absorption material and perforated panel dimensions. Noise barriers consist of front perforated panel, sound absorption material and back plate. Noise barriers' acoustic performance should be required to meet the NRC of 0.7. The absorbing performance of the noise barrier relies on the opening ratio of perforated panel and the efficiency of the absorbing material. This study try to find out the possibilities of applications to railway usage.

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Response of a laterally loaded pile group due to cyclic loading in clay

  • Shi, Jiangwei;Zhang, Yuting;Chen, Long;Fu, Zhongzhi
    • Geomechanics and Engineering
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    • v.16 no.5
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    • pp.463-469
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    • 2018
  • In offshore engineering, lateral cyclic loading may induce excessive lateral movement and bending strain in pile foundations. Previous studies mainly focused on deformation mechanisms of single piles due to lateral cyclic loading. In this paper, centrifuge model tests were conducted to investigate the response of a $2{\times}2$ pile group due to lateral cyclic loading in clay. After applying each loading-unloading cycle, the pile group cannot move back to its original location. It implies that residual movement and bending strain are induced in the pile group. This is because cyclic loading induces plastic deformation in the soil surrounding the piles. As the cyclic load increases from 62.5 to 375 kN, the ratio of the residual to the maximum pile head movements varies from 0.30 to 0.84. Moreover, the ratio of the residual to the maximum bending strains induced in the piles is in a range of 0.23 to 0.82. The bending strain induced in the front pile is up to 3.2 times as large as that in the rear pile. Thus, much more protection measures should be applied to the front piles to ensure the serviceability and safety of pile foundations.

A Numerical Study on the Drag of Axial Cylinder (종축 실린더의 항력에 대한 수치 해석적 연구)

  • Lee, Hyun-Bae;Choi, Jung-Kyu;Kim, Hyoung-Tae
    • Journal of the Society of Naval Architects of Korea
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    • v.49 no.6
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    • pp.512-520
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    • 2012
  • In this study, the numerical analysis for the flows around an axial cylinder is carried out in order to investigate the basic characteristics of drag of blunt body. A variation of drag and flow separation for the axial cylinder is investigated according to the length-diameter ratio. Also, the flow separation around the head is removed by rounding-off the front edge of the body to analyze the effect of drag reduction. Most of the drag turns out to be a pressure drag component and the variation of drag is caused by the change of pressure and velocity which is affected strongly by the flow separation at the edges of the axial cylinder. Especially, it is found that the pressure drag component acting on the back of axial cylinder, as known as the base drag, mainly changes the drag. As the length-diameter ratio of axial cylinder increases, the drag sharply decreases and the minimum is shown when the length-diameter ratio is about 2.4. Also, as the length-diameter ratio increases further above 2.4, the drag increases at a slower rate. The pressure drag is almost constant when the length-diameter ratio is greater than 8, but the increase of friction drag component is the reason for the increase of the drag. When flow separation is removed completely at the front edge of the axial cylinder, the pressure drag component is reduced to 12~17%, but the total drag is reduced to only 17%~32% due to the friction drag component that increases linearly proportional to the length-diameter ratio.

Analysis of Lower body on Korean Young Women and the Effect of the Lower body Type on the Shape of Flare Skirt (II) (한국 미혼 여성의 하반신체형 분석과 체형변인이 플레어스커트 입체성능에 미치는 영향(II))

  • 조정미
    • Journal of the Korean Home Economics Association
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    • v.30 no.3
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    • pp.15-32
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    • 1992
  • The purpose of this study was to detect the effect of the lower body type on the shape of flare skirts. The subjects for the wearing test were 50 female students, who were controlled in their hip and waist shapes. The skirts used for wearing test were six types(three flar angles $\times$ two fabric types). The effect of lower body type on the shape of flare skirts was determind by the hemline trace method and the silhouette photography. The data were then analyzed by the repeated measures of analysis of variance and the SNK multiple range test. The results obtained from this study were as follows : 1) When a flare skirt made with larger flare angle and better drapable fabric was worn, the numeric of the nodes increased as the drop value(hip - waist) increased. When a flare skirt made with smaller flare angle was worn, the width of horizontal sectio of hemline increased as the drop value increased. The hemline uneveness decreased on the sides and back as the drop value increased. When a flare skirt made with worse drapable fabric was worn, the sides angle of the flarskirt increased as the drop value increased. 2) When a flare skirt made with larger flare angle was worn, the numeric of nodes increased as the ratio of dropped hip increased. The wave-height increased and the back variation ratio of wave-height was higher than the front variation ratio of wave-height as the ratio of dropped hip increased. The hemiline uneveness decreased on the back as the ratio of dropped hip increased. When a flare skirt made with larger flare angle was worn, the sides angle of the flare skirt increased as the ratio of dropped hip increased.

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A Clothing-Ergonomics Study on the Variation of Upper Arm Skin Surface According to Arm Movements - on the arm movements to the vertical direction in front and in side - (신체동작에 따른 상지형태변화에 관한 피복인간공학적 연구 - 전방수직동작과 측방수직동작을 중심으로 -)

  • Kim Hae-Kyung;Park Eun-Joo;Jeon Eun-Kyung
    • Journal of the Korean Society of Clothing and Textiles
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    • v.13 no.1 s.29
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    • pp.49-58
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    • 1989
  • A clothing-erogonomics study was performed to investigate the difference of the upper arm skin skin surface and the relationship among the three aspects of upper arm (height of sleeve rap, sleeve width and armhole girth) by changing arm movements. Plaster cast was used for this experimental research. Arm movements consist of 9 types; just carmly standing on ($0^{\circ}$), and each 4 types ($45^{\circ},\;90^{\circ},\;135^{\circ},\;180^{\circ}$) to the vertical direction in front and in side. The results were as follows; 1) As the arm-movement angle increased, the height of sleeve cap decreased and that ratio was largest in the portion A-B3. 2) The steeve width was enlarged with the increment of movement angle in all portions of upper arm except B1-B5. 3) As increasing the movement angle, the whole armhole girth decreased and the ratio o(front armhole girth (F-A) was larger than that of back. 4) In the vertical direction in front, the height o( the sleeve caps was larger, the sleeve widths were smaller than in the vertical direction in side in all movement types, but there was no significant difference in arm-hole girth between the two cases. 5) There were significantly negative relationships between measurements in height of sleeve cap and those in sleeve width, and also between those in height of sleeve cap and in arm-hole girth. And significantly positive relationships were found between neasurements in height of sleeve cap and those in arm-hole girth.

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