• Title/Summary/Keyword: Pressure Distribution

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Investigation of the body distribution of load pressure and virtual wear design of short pants harnesses in flying condition (플라잉 상태에서 바지형태의 하네스에 대한 하중압력 분포 측정 및 가상착의 적용)

  • Kwon, MiYeon
    • Journal of the Korea Fashion and Costume Design Association
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    • v.23 no.3
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    • pp.11-21
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    • 2021
  • Virtual reality is currently mainly used in games, but is starting to be applied as a variety of media fields, such as broadcasting and film. Virtual reality provides more fun than reality, and can provide new experiences in areas that cannot be experienced in reality due to the constraints of time, space, and environment. In particular, as the social non-contact arena has increased due to COVID-19, it is being applied to education, health, and medical industries. The contents are further expanding into design and military fields. Therefore, the purpose of this study was to observe the change in distribution of load and pressure felt by the body in the flying state while wearing a short pants harness, which are mainly used in the game and entertainment industry. In the experiment, the average pressure in the flying state was measured by attaching a pressure sensor to the back and front of a human mannequin. As a result, it was confirmed that the load concentrated on the waist in the flying state was 44 N, with a pressure of 1353 kPa. The pressure distribution was concentrated in front of the center of gravity, and was measured was at 98% by the pressure sensors, with an average pressure value of approximately 15 kPa, and a pressure value of approximately 12 kPa at the back, which was measured at 67% by the pressure sensor. The results of the load and pressure distribution measurement are presented as fundamental data to improve the wearability and comfort of harnesses in the future, and are compared to actual measured pressure values by analyzing the clothing pressure in flight through virtual wear of harnesses through the CLO 3D program.

Prediction of Extreme Sloshing Pressure Using Different Statistical Models

  • Cetin, Ekin Ceyda;Lee, Jeoungkyu;Kim, Sangyeob;Kim, Yonghwan
    • Journal of Advanced Research in Ocean Engineering
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    • v.4 no.4
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    • pp.185-194
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    • 2018
  • In this study, the extreme sloshing pressure was predicted using various statistical models: three-parameter Weibull distribution, generalized Pareto distribution, generalized extreme value distribution, and three-parameter log-logistic distribution. The estimation of sloshing impact pressure is important in design of liquid cargo tank in severe sea state. In order to get the extreme values of local impact pressures, a lot of model tests have been carried out and statistical analysis has been performed. Three-parameter Weibull distribution and generalized Pareto distribution are widely used as the statistical analysis method in sloshing phenomenon, but generalized extreme value distribution and three-parameter log-logistic distribution are added in this study. Additionally, statistical distributions are fitted to peak pressure data using three different parameter estimation methods. The data were obtained from a three-dimensional sloshing model text conducted at Seoul National University. The loading conditions were 20%, 50%, and 95% of tank height, and the analysis was performed based on the measured impact pressure on four significant panels with large sloshing impacts. These fittings were compared by observing probability of exceedance diagrams and probability plot correlation coefficient test for goodness-of-fit.

Study on Relationship between Discomfort and Body Pressure Distribution on the Seat under Height of Footrest and Angle of Seatpan (발판 높이와 의자밑판 각도에 따른 체압분포 변화와 불편함의 상관성 평가)

  • Park, Dong-Woon;Ahn, Se-Jin;Yoo, Wan-Suk
    • Transactions of the Korean Society of Automotive Engineers
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    • v.15 no.6
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    • pp.38-43
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    • 2007
  • In this paper, a study is described on finding a relationship between discomfort and body pressure distribution. In the first step, experiments were conducted to find correlation between pressure distribution and discomfort. The experiments of 12 people on 9 seats were performed. In the second step, parameters and correlation coefficients were determined between the measured body pressure distribution and median values of the subjective evaluations of 12 subjects using psychophysical power law.

The Characteristics on Arc Pressure Distribution of TIG Welding with Shield Gas Mixing Ratio (TIG 용접에서의 실드 가스 혼합비에 따른 아크 압력분포 특성)

  • Oh Dong-Soo;Kim Yeong-Sik;Cho Sang-Myung
    • Journal of Welding and Joining
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    • v.23 no.1
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    • pp.41-47
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    • 2005
  • Arc pressure is one of important factors in understanding physical arc phenomena. Especially it affects on the penetration, size and shape of TIG welding. Some researches were reported on the effect of arc pressure in low and middle current region. But there are not any research in high current region. The purpose of this study is to investigate the arc pressure distribution with mixing ratio of shield gas such as Ar and He gases. A Cu block with water cooling was specifically designed and used as an anode electrode in order to measure the arc pressure in high current region. Then, the arc pressure distribution was measured with change in welding current and mixing ratio of shield gases. The arc force was obtained by numerically integrating the measured results. As the results, it was shown that the arc pressure was concentrated at the central part of the arc in middle and high current regions when a pure Ar gas was used. In case of Ar + He mixing gas, the arc pressure was much lower than that of pure Ar gas. In addition, it was widely distributed to radial direction.

A Study on a Fuzzy Controller for the Electronic Braking Force Distribution System (전자식 차량 제동력 배분 시스템을 위한 퍼지제어기의 연구)

  • 김승대;김훈모
    • Transactions of the Korean Society of Automotive Engineers
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    • v.8 no.6
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    • pp.220-229
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    • 2000
  • In the brake systems a proportioning valve which reduces the brake pressure at each wheel cylinder for anti-locking of rear wheels is closely related with the safety of vehicles. But, it is impossible for a present proportioning valve to exactly control brake pressure because mechanically it is an open loop control system. So, in this paper we describe a electronic brake pressure distribution system using a fuzzy controller in order to exactly control brake pressure using a close loop control system. The object of electronic brake pressure distribution system is to change an cut-in pressure and an valve slop of proportioning valve in order to obtain better good performance of brake system than with mechanical system.

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The Effect of Pressure on the Abnormal Grain Growth in Alumina (알루미나의 비정상 입자성장에 미치는 압력의 영향)

  • Park, Hoon;Park, Sang-Yeup
    • Journal of the Korean Ceramic Society
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    • v.37 no.7
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    • pp.617-624
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    • 2000
  • Abnormal grain growth in alumina was investigated during sinter-HIP process for better understanding of pressure effect on microstructural development. Abnormal grain growth of monolithic alumina was observed near surface region rather than interior region of specimen. Finite element analysis was used to estimate the pressure distribution developed in the specimen. Pressure distribution analysis was in good agreement with grain size distributjion in the specimen. The results of finite element analysis provided that abnormal grain growth monolithic alumina was resulted from the inhomogeneous pressure distribution in the specimen. MgO addition in alumina was effective for the suppression of abnormal grain growth in alumina under inhomogeneous pressure distribution during sinter-HIP process.

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Spray Distribution Measurement at High Ambient Pressure (고압 환경 하에서의 분무 분포 측정)

  • Cho, Seong-Ho;Im, Ji-Hyuk;Yoon, Young-Bin;Choi, Seong-Man;Han, Young-Min
    • Journal of the Korean Society of Visualization
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    • v.6 no.1
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    • pp.59-65
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    • 2008
  • Distribution of spray was measured. Optical Line Patternator (OLP) was used to measure the planar distribution of the spray from a swirl-coaxial type injector. Ambient pressure was varied and injection pressure was fixed in experiment. As ambient pressure increased, spray distribution was changed from hallow cone to solid cone shape, and spray angle was decreased. Limitation in measuring dense spray was found at high ambient pressure condition.

Size of Sink mark according to the operation conditions in injection molding (사출성형에서 캐비티내의 압력분포와 sink mark와의 관계)

  • Ahn, J.H.;Hwang, S.J.;Lyu, M.Y.
    • Proceedings of the Korean Society for Technology of Plasticity Conference
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    • 2007.05a
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    • pp.217-220
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    • 2007
  • The quality of product depends on a lots of injection molding conditions at each operation stage and mainly was effected by pressure and temperature. The objective of this study was to investigate the relationship between the product quality and the distribution of pressure in a cavity with operation condition change. Specimen having some ribs was designed and the mold was prepared and temperature and pressure sensors were installed in the mold. PP was used and pressure distribution was measured with operation condition change. The relationship between the sink mark and the pressure in a cavity was investigated by measurement of the level of sink mark. The level of sink mark was decreased at the cross of plane and rib by increasing of pressure in a cavity, so the pressure should be controlled properly in order to get the required quality.

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The Effect of Pressure-time Condition Affect in Properties of Superplastic Formed part (압력 조건이 초소성 성형품의 성질에 미치는 영향)

  • Lee, Yeong-Seon;Lee, Jeong-Hwan
    • 연구논문집
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    • s.29
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    • pp.185-194
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    • 1999
  • The shape and thickness distribution according to the pressure-time curve were carried out using the FEM and experiment. Also, mechanical properties were investigated. The square cup parts have been formed with pressure-time curve generated by result of analysis. The tensile strength and elongation have been investigated according to applied pressure conditions using the tensile test specimen obtained from the superplastic formed cup. We can use to predict the shape of formed part under the applied pressure using the FEM analysis. In the case of optimum pressure condition, the thickness distribution and mechanical properties were improved. From this study, we can find the important of optimum pressure-time condition. We have investigated about the forming of airplane part and fuel tank for motorcycle. If the applied load used in boundary conditions was appropriate, the simulation result coincides with the formed part. However, it is very difficult to define the pressure condition in complicated shape. Thus, it is need to develop the optimum pressure condition for superplastic forming.

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Numerical Analysis of Pressure Distribution in Piston-Cylinder Unit for Accurate Pressure Measurement (유압측정을 위한 피스톤-실린더 간격내의 압력분포에 대한 수치해석)

  • U, Sam-Yong;Park, Jong-Ho
    • Transactions of the Korean Society of Mechanical Engineers B
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    • v.20 no.9
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    • pp.2909-2915
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    • 1996
  • Precise and accurate pressure measurements are obtained using deadweight piston gauges. Pressure distribution and elastic distortion in the piston-cylinder unit are the leading factors in determination of effective area. The distortion depends upon the pressure distribution in the clearance between piston and cylinder and those are coupled each other. Considering the viscosity pressure relation of oil and governing flow equation in the clearance, a new numerical iterative algorithm is developed. The disagreement between the monotonous and sharp pressure profiles is an indication that the pressure profile will be different for each piston and cylinder unit due to material variances.