• Title/Summary/Keyword: Drop height

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A Study on Sizing System for Middle Aged Men (중년 남성의 치수 체계에 관한 연구)

  • Sung Ok-jin;Yang Chung-eun
    • Journal of the Korean Society of Clothing and Textiles
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    • v.29 no.6
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    • pp.764-771
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    • 2005
  • This study is to increase the efficiency for the suitability of clothing measurement and the production utility factors by setting up the measurement system with middle-aged men's physical characteristics. For this purpose this study measured the body sizes of middle-aged men and analyzed basic sizing items such as drop, height, and bust according to the ISO and KS systems and classified these sizes based on body shapes and heights. As a result, an internationally-compatible measuring system is presented in this study. The most common body shapes are portly (Drop 6) and regular (Drop 12) types and these two types form $74.7\%$. The height of 164cm$(31.2\%)$ and 170cm$(38.2\%)$ cover $69.4\%$; and the most general sizes of busts are 92, 96 and 100 and these sizes occupy $74.7\%$. In consideration of the ranges of height and bust, the general sizes (7 regular types and 9 portly types) are selected to present the standardized measurements; the mark for the top is height-bust-waist and the mark for the bottom is stature-waist-hip.

A curtain traveling pluviator to reconstitute large scale sand specimens

  • Kazemi, Majid;Bolouri, Jafar B.
    • Geomechanics and Engineering
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    • v.14 no.2
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    • pp.131-139
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    • 2018
  • The preparation of repeatable and uniformly reconstituted soil specimens up to the specified conditions is an essential requirement for the laboratory tests. In this study for large samples replication, the simultaneous usage of the traveling pluviation and curtain raining technique is used to develop a new method, called the curtain travelling pluviator (CTP). This simple and cost effective system is based on the air pluviation approach, whilst reducing the sample production time, can reproduce uniform samples with relative densities ranging from 25% to 96%. In order to investigate the resulting suitability and uniformity from the proposed method, a series of tests is performed. The effect of curtain traveling velocity, curtain width, drop height, and flow rate on the parameters of the sample is thoroughly investigated. Increase in the curtain velocity and drop height leads to the increase in relative density for the sand specimen. Increase in curtain width typically resulted in the reduction of relative density. Test results reveal that the terminal drop height for the sand specimen in this study is more than 500 mm. Relative density contour lines are presented that can be utilized in optimizing the drop height and curtain width parameters. Sample uniformity in the vertical and horizontal orientation is investigated through the sampling containers. Increasing relative density tends to result in the higher sample repeatability and uniformity.

A Study on the Sizing System for Clothes of Lower Body -females from l9 to 24 years old- (하의 치수 체계에 관한 연구 -만 19 ~ 24세 여자를 중심으로-)

  • 문명옥
    • Journal of the Korean Society of Clothing and Textiles
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    • v.26 no.7
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    • pp.1036-1042
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    • 2002
  • The purpose of this study was to set up the sizing system for clothes of lower body. Sample size was 191 females and their age ranges were from 19 to 24 years old. The lower body types for the sizing system were categorised by height and drop value of lower body(hip circumference-waist circumference). The results were as follows. 1. The Thick waist (drop value of lower body<21) and the Slender waist (drop value of lower body$\geq$27) had the low coverage rates of 14.2% and 11.5%, and the Normal waist (21$\leq$ drop value of lower body<27) had the high coverage rate of 72.8%. 2. The height could be divided into three groups and thar covered 97.5%. The Short(152cm) covered 2l.0%, the Regular(160cm) 58.7% and the Tall(168cm) 17.8%. 3. The size interval of hip circumference was 4cm and the intervals of waist circumference were 3cm and 4cm. The interval of slacks length was 4∼5cm according to three height groups.

The Effect of Raised Heel Insole and Landing Height on the Shock Absorption Mechanism during Drop Landing (드롭 착지 시 착지의 높이와 키 높이 깔창이 충격흡수 기전에 미치는 영향)

  • Cho, Joon-Haeng;Kim, Ro-Bin
    • Korean Journal of Applied Biomechanics
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    • v.24 no.2
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    • pp.131-138
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    • 2014
  • The purpose of this study was to analyse the effect of the drop height on lower extremity and lower back kinematics and kinetics during drop landing with the use of raised heel insole. Furthermore we investigated the change that occurred in our body. Joint ROM, eccentric work and contribution to total work were calculated in 11 male college students performing drop landing with 8 motion analysis cameras and 1 forceplate. The result were as follows. First, the ROM and eccentric work were increased in all joints with the increase of the drop height. Second, the ankle ROM and eccentric work were decreased with the use of the insole. Third, the use of the lower back was increased as the use of the ankle decreased with the insole. Based on these results, we can infer that putting on the insole may contribute to chronic injury. We recommend not to use the insole during physical activity.

The effect of Arch Support Taping on Plantar Pressure and Navicular Drop Height in subjects with Excessive pronated foot during 6 Weeks (6주간의 활지지 테이핑(arch support taping) 적용이 과도하게 엎침된 발의 발바닥압력과 발배뼈 높이에 미치는 영향)

  • Kim, Tae-Ho;Koh, Eun-Kyung;Jung, Do-Young
    • Journal of the Korean Society of Physical Medicine
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    • v.6 no.4
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    • pp.489-496
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    • 2011
  • Purpose : The purpose of this study was to identify the effect of an arch support taping on navicular drop height and plantar pressure in the subjects with excessive pronated foot for 6 weeks. Methods : The fifteen subjects with the pronated foot group and the fifteen subjects with the normal foot group volunteered for this study. Both groups were applied arch support taping at 3 times a week during 6 weeks. Subjects were assessed navicular drop test to evaluate pronation of subtalar joint and plantar pressure on treadmill for pressure measuring system during walking with a bare foot state at pre- taping, after 3 weeks, and after 6 weeks. A two-way repeated analysis of variance design was used to examine the difference of navicular drop height and plantar pressure in the pronation foot group and the normal foot group. Results : The pronated foot group had significantly decreased both the navicular drop height and the plantar pressure under the medial midfoot than the normal foot group after 6 weeks(p<.01). Conclusions : This study proposed that an arch support taping can be support to lift navicular bone as well as to transfer the foot pressure from medial midfoot to lateral midfoot in individuals with excessive pronated foot.

Characteristics of Fin-Side Heat-Transfer and Pressure Drop in a Condenser for Automobile (자동차용 응축기의 휜 열전달 및 압력강하 특성)

  • 곽경민;이홍열
    • Transactions of the Korean Society of Automotive Engineers
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    • v.12 no.3
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    • pp.152-158
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    • 2004
  • An experimental study was performed to determine the fin-side heat transfer and pressure drop of a condenser for automobile. Five sample with different fin height and louver angle were tested, 9mm, 8mm, 7.5mm, 5.4mm and 4.5mm. Results are presented as plot of Colburn j-factor(or heat transfer coefficients) and friction factor(or pressure drop) against the Reynolds number(or inlet air velocity) based on louver pitch, in the range of 110 to 480. The results show that both heat transfer and pressure drop on the fin are mainly affected by the louver angle in a lower range of air velocity, but, by the fin height in a higher range of air velocity. The performance of 5.4mm fin is the highest, compared to other fin sample.

NUMERICAL ANALYSIS OF THE IMPACTING AND SPREADING DYNAMICS OF THE ELLIPSOIDAL DROP ON THE PERFECT NON-WETTING SOLID SURFACE (완전 비습윤 고체 표면 위 타원형 액적의 충돌 및 퍼짐 거동에 대한 수치적 연구)

  • Yun, S.
    • Journal of computational fluids engineering
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    • v.21 no.4
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    • pp.90-95
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    • 2016
  • Leidenfrost drops with ellipsoidal shaping can control the bouncing height by adjusting the aspect ratio(AR) of the shape at the moment of impact. In this work, we focus on the effect of the AR and the impact Weber number(We) on the non-axisymmetrical spreading dynamics of the drop, which plays an important role in the control of bouncing. To understand the impact dynamics, the numerical simulation is conducted for the ellipsoidal drop impact upon the perfect non-wetting solid surface by using volume of fluid method, which shows the characteristics of the spreading behavior in each principal axis. As the AR increases, the drop has a high degree of the alignment into one principal axis, which leads to the consequent suppression of bouncing height with shape oscillation. As the We increases, the maximum spreading diameters in the principal axes both increase whereas the contact time on the solid surface rarely depends on the impact velocity at the same AR. The comprehensive understanding of the ellipsoidal drop impact upon non-wetting surface will provide the way to control of drop deposition in applications, such as surface cleaning and spray cooling.

Analysis of the Differences of the Shock Absorption Strategy between Drop-Landing and Countermovement-Jump (드롭 착지와 착지 후 점프 시 충격흡수 기전의 차이 분석)

  • Cho, Joon-Haeng;Kim, Kyoung-Hun;Koh, Young-Chul
    • Korean Journal of Applied Biomechanics
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    • v.22 no.4
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    • pp.379-386
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    • 2012
  • The aim of this study was to investigate and identify the differences in lower extremity energy dissipation strategies between drop-landing and countermovement-jump maneuvers. Fourteen recreational athletes(Age : $23.3{\pm}2.1years$, Height : $172.3{\pm}4.0cm$, Weight : $69.2{\pm}4.7kg$) were recruited and instructed to perform drop-landing from 45 cm height and countermovement-jump from 45 cm to 20 cm height. The landing phase was taken as the time between initial contact and peak knee flexion. A motion-capture system consisting of eight infra-red cameras was employed to collect kinematics data at a sampling rate of 200 Hz and a force-plate was used to collect GRF data at a sampling rate of 2000 Hz. Paired t-test was performed to determine the difference in kinematics and kinetics variables between each task. During the countermovement-jump task, all of lower extremity joint ROM and the hip joint eccentric moment were decreased and the ankle joint plantarflexion moment was increased than drop-landing task. In the eccentric work during countermovement-jump task, the ankle joint displayed greater while knee and hip joint showed lesser than drop-landing. Therefore, the knee joint acted as the key energy dissipater during drop-landing while the ankle joint contributed the most energy dissipation during countermovement-jump. Our findings collectively indicated that different energy dissipation strategies were adopted for drop-landing and countermovement-jump.

The Effect of Visual & Cognitive Information of Landing Height on Landing Strategy during Drop Landing (드롭랜딩 시 낙하높이에 대한 시각 및 인지 정보가 착지 전략에 미치는 영향)

  • Eun, Seon-Deok;Yang, Jong-Hyun;Kim, Yong-Woon;Kang, Myeong-Soo;Kwak, Chang-Soo
    • Korean Journal of Applied Biomechanics
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    • v.22 no.4
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    • pp.405-411
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    • 2012
  • The purpose of this study was to determine the effects of landing height information on landing strategy during a drop landing. Ten healthy male subjects(age: $22.1{\pm}1.9year$, height: $178.4{\pm}7.8cm$, mass: $75.3{\pm}9.4kg$) participated in this study. Each participant was asked to jump with both legs off a 40 cm high box on one of the three plates with different thickness (0 cm, 13 cm, 26 cm). In the first condition, subjects were given both cognitive and visual information about the jumping heights. In the second, they were given only cognitive information without visual one, and in the third, no information about the height was provided to subjects. (Only the data collected from the 40 cm height landing were analyzed and reported in the present study.) The results showed that landing strategies during a double-leg drop landing from 40 cm height were not significantly affected by visual and cognitive information blockages. Also, there were no statistically significant differences in landing strategies between the three conditions even though the mean differences attained in this study seemed to warrant further studies investigating the relationship between landing strategies and cognitive information.

Effects of Navicular Drop on Lumbar Disc Herniation (주상골 하강이 요추 추간판 탈출증에 미치는 영향)

  • Hwang, Gwon-Pil;Jung, Min-Keun;Park, Hyun-Sik
    • The Journal of Korean Academy of Orthopedic Manual Physical Therapy
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    • v.19 no.2
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    • pp.19-22
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    • 2013
  • Background: Excessive pronation of the feet can cause excessive inner rotation of the femur, followed by increased stress in the gluteus maximum, increased front slope of the pelvis, and lumbar lordosis, which leads to lumbar pain. The aim of the present study was to use the navicular drop test to examine foot pronation that can cause lumbar lordosis and to determine whether the navicular drop is lower in patients diagnosed with lumbar disc than in patients without this diagnosis. Methods: The Navicular Drop score was set by subtracting the navicular height at a standing position from the navicular height in a sitting position. The Navicular Drop measurements for college student with and without Lumbar Herniated Intervertebral Disc were compared using an independent t-test. Results: The control group were measured right $7.44{\pm}2.96$ and left $8.04{\pm}3.23$. The experimental group were measured right $2.12{\pm}1.33$ and left $2.80{\pm}1.29$. Therefore significant difference was found between the two groups (p<0.05). Conclusions: The navicular drop affected lumbar herniated intervertebral disc.

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