• Title/Summary/Keyword: Pressure-distribution

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Mechanical Analysis of golf driving stroke motion (골프드라이빙 스트로크시 역학적 분석)

  • Park, Kwang-Dong
    • Korean Journal of Applied Biomechanics
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    • v.12 no.1
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    • pp.205-219
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    • 2002
  • This research seeks to identify the plantar pressure distribution graph and change in force in connection with effective golf drive strokes and thus to help ordinary golfers have appropriate understanding on the moving of the center of weight and learn desirable drive swing movements. To this end, we conducted surveys on five excellent golfers to analyze the plantar pressure applied when performing golf drive strokes, and suggested dynamic variables quantitatively. 1) Our research presents the desire movements as follows. For the time change in connection with the whole movement, as a golfer raises the club head horizontally low above ground from the address to the top swing, he makes a semicircle using the left elbow joint and shaft and slowly turns his body, thus lengthening the time. And, as the golfer twists the right waist from the middle swing to the impact with the head taking address movement, and does a quick movement, thus shortening the time. 2) For the change in pressure distribution by phase, to strike a strong shot with his weight imposed from the middle swing to the impact, a golfer uses centrifugal force, fixes his left foot, and makes impact. This showed greater pressure distribution on the left sole than on the right sole. 3) For the force distribution graph by phase, the force in the sole from the address to halfway swing movements is distributed to the left foot with 46% and to the right foot with 54%. And, with the starting of down swing, as the weight shifts to the left foot, the force is distributed to the left sole with 58%. Thus, during the impact and follow through movements, it is desirable for a golfer to allow his left foot to take the weight with the right foot balancing the body. 4) The maximum pressure distribution and average of the maximum force in connection with the whole movement changed as the left (foot) and right (foot) supported opposing force, and the maximum pressure distribution also showed much greater on the left sole.

Effects of Gastrocnemius Muscle Length on the Dynamic Balance and Antero-posterior Pressure Distribution of Foot (장딴지근 길이가 동적 균형 및 발바닥의 앞뒤 압력 분포에 미치는 영향)

  • Lee, Won-Hwee
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.20 no.6
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    • pp.150-157
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    • 2019
  • The purpose of this study was investigate the effect of gastrocnemius(GCM) muscle length on the dynamic balance and antero-posterior pressure distribution of foot. Thirty subjects were recruited and each subject was classified with control experimental and control group according to GCM muscle length. The experimental group included subjects with shortness of GCM muscle length, the control group included subjects with normal length of GCM. The dynamic balance and antero-posterior pressure distribution of foot were measured by Biorescue equipment. To evaluate dynamic balance, we collected data of limit of stability in antero-posterior direction. We analyzed the data by using independent t-test. The alpha level was set 0.05. The results showed that the dynamic balance and antero-posterior pressure distribution of foot were significantly different between two groups (p<0.05). This study suggests that the shortness of GCM affects anterior limited of stability in dynamic balance and anterior pressure distribution of foot. Therefore, it is important to maintain optimal GCM muscle length for normal balance ability and prevention of musculoskeletal disease.

A Study on the Characteristic of Contact Pressure for CPB (Cold Pad Batch) Padder Roll Controlled by Hydraulic Single Cell (단일 유압 Cell로 제어되는 CPB(Cold Pad Batch)용 패더롤의 접촉압력 특성 연구)

  • Cho, Kyung-Chul;Lee, Eun-Ha;Jo, Soon-Ok;Park, Si-Woo;Hwang, Youn-Sung;Kim, Soo-Youn
    • Textile Coloration and Finishing
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    • v.29 no.2
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    • pp.86-96
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    • 2017
  • To make uniform pressure distributed over the contact surface was necessary to cold pad batch dyeing machine. In this study, to confirm characteristic of flexibility and the contact pressure distribution through experimental analysis of padder roll were controlled by hydraulic cell. When there were no load pressure only inner pressure, the value of displacement in the center of padder were greater than the end of the padder. The results of this study showed that the padder had the optimum value of inner pressure for uniform contact pressure distribution. Measuring the contact pressure in a padder system were driven by using a pre-scale film. Uniform contact pressure distribution of cell padder were a linearly with load pressure and inner pressure. When the load pressure was less than 8 tons, the inner pressure for the uniform contact pressure was 1~4 bar. The padder roll performance curves proposed in this study were available for practical production environments and various roll designs.

Measurement of Unsteady Total Pressure downstream of an 1-Stage Axial Turbine (1단 축류터빈 로터의 후류에서 비정상 전압력 측정에 관한 연구)

  • Kang, Jeong-Seek;Cha, Bong-Jun;Yang, Soo-Seok;Lee, Dae-Sung
    • 유체기계공업학회:학술대회논문집
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    • 2005.12a
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    • pp.318-323
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    • 2005
  • To evaluate the accurate performance of turbomachinery, it is important to measure the unsteady flow phenomena downstream of the rotor blade. This paper presents the development of the fast-response total pressure probe for the measurement of the total pressure field at the exit of rotor and the result of measurement in a 1-stage axial turbine. The fast-response total pressure probe was fabricated by installing a fast-response pressure sensor near the head of a Kiel probe. And it measured the phase-lock averaged total pressure downstream of an 1-stage axial turbine. The developed probe successfully measured the accurate total pressure distribution at rotor exit and made possible to evaluate the loss distribution and the accurate performance of turbomachinery.

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OPTIMUM AIR PRESSURE FOR AN AIR-CELL SEAT TO ENHANCE RIDE COMFORT

  • YOO W. S.;PARK D. W.;KIM M. S.;HONG K. S.
    • International Journal of Automotive Technology
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    • v.6 no.3
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    • pp.251-257
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    • 2005
  • Several air cells are installed in the seat cushion to adjust the stiffness of seat by changing the air pressure. To select proper air pressure in the air cells, two kinds of tests are performed. For the pressure distribution on the seat, the maximum pressure and mean pressure are compared. And for the dynamic ride values, SEAT (Seat Effective Amplitude Transmissibility) values are calculated and compared. These experiments are carried out with three different drivers, three different vehicle speeds on the highway and two different speed on the primary road, and three different air pressures. From the real car tests, optimum air cell pressure depending on the vehicle speed and driver's weight are recommended.

Measurement of Oil Pressure Distribution between the Piston and Cylinder in Hydraulic Piston Pump (유압 피스톤 펌프의 피스톤과 실린더 사이에서의 압력측정)

  • 김영환;박태조
    • Proceedings of the Korean Society of Tribologists and Lubrication Engineers Conference
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    • 2000.06a
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    • pp.237-242
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    • 2000
  • In this paper, an experiment was carried out to measure the hydrodynamic oil pressure distribution in the clearance gap between a piston and cylinder. The results showed that the pressure distributions are highly affected by the eccentricity of the piston. Therefore present experimental method can be used to enhance the performance of hydraulic piston pumps. Further experimental studies for various operating conditions and improvement in data acquisition methods are required to obtain more accurate results.

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Study on the Fuel Vapor Distribution of the Stratified Charge in a DISI Engine by PLIF Technique (직분식 전기점화 엔진에서 PLIF기법에 의한 성층 혼합기의 분포특성 연구)

  • Kim, S.S.
    • Journal of Power System Engineering
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    • v.12 no.6
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    • pp.64-69
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    • 2008
  • The spatial fuel distribution of the stratified charge of a high pressure 6-hole injector was examined in a single cylinder optical direct injection spark ignition(DISI) engine. The effects of in-cylinder charge motion, and fuel injection pressure, and coolant temperature were investigated using a planar LIF(Laser Induced Fluorescence) technique. It was confirmed that the in-cylinder tumble flow played more effective role in the spatial fuel distribution of the stratified charge than the swirl flow during the compression stroke and the fuel distribution area increased due to the activation of the fuel vaporization by the increase of the coolant temperature. But, the increase of the fuel supplying pressure could not change the pattern of the fuel vapor distribution against the expectation.

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Measurement of Spray Distribution of Swirl Injector by Tomography method (토모그래피 기법을 이용한 스월 인젝터의 분무 분포 계측)

  • Park, Gu-Jeong;Cho, Seong-Ho;Chung, Jae-Mook;Kim, Tae-Sung;Yoon, Young-Bin
    • Proceedings of the Korean Society of Propulsion Engineers Conference
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    • 2011.04a
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    • pp.39-44
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    • 2011
  • This study constructed the spray distribution by the Tomography method at high pressure condition. The constructed spray distribution was compared with the images by Indirect Photography method so that the spray size was confirmed and took the boundary of the distribution. It was confirmed that the Tomography applies to construct the distribution at high pressure.

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Nonlinearly Distributed Active Earth Pressure on n Translating Rigid Retaining Wall : I. Formulation (평행이동하는 강성옹벽에 작용하는 비선형 주동토압 : I. 정식화)

  • 백규호
    • Journal of the Korean Geotechnical Society
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    • v.19 no.1
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    • pp.181-189
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    • 2003
  • The active earth pressure against a rigid retaining wall has been generally calculated using either Rankine's or Coulomb's formulation. Both assume that the distribution of active earth pressure exerted against the wall is triangular. However, many experimental results show that the distribution of the active earth pressure on a rigid rough wall is nonlinear. These results do not agree with the assumption used in both Rankine's and Coulomb's theories. The nonlinearity of the active earth pressure distribution results from arching effects in the backfill. Several researchers have attempted to estimate the active earth pressure on a rigid retaining wall, considering arching effect in the backfill. Their equations, however, have some limitations. In this paper, a new formulation for calculating the active earth pressure on a rough rigid retaining wall undergoing horizontal translation is proposed. It takes into account the arching effects that occur in the backfill.

Determination Methods of Pressure Monitoring Location in Water Distribution System (상수관망에서 수압모니터링지점 선정방법)

  • Kwon, Hyuk Jae
    • Journal of Korea Water Resources Association
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    • v.46 no.11
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    • pp.1103-1113
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    • 2013
  • In this study, determination methods of the pressure monitoring location in water distribution system were introduced and applied to sample pipe network. The best determination method of the pressure monitoring location was suggested and applied to the real city pipe network. Three kinds of determination methods of pressure monitoring locations are categorized such as the sensitivity analysis according to changing roughness coefficient, pressure contribution analysis, and sensitivity analysis according to changing demand. Further-more, pressure contribution analysis and sensitivity analysis from the results of unsteady analysis were conducted and compared each other. From the results, the most accurate and simplest method was selected in this study. Therefore, the best method can be applied for the pressure management or leakage detection as a determination method of pressure monitoring location in water distribution system.