• 제목/요약/키워드: Correlation of Pressure Distribution Analysis

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초등학교 야구선수들의 우세손에 따른 족저압과 신체 정렬간의 상관관계 분석 (Correlation Analysis between Plantar Pressure and Body Alignment According to the Dominant Hand of Elementary School Baseball Players)

  • 정모범
    • 대한물리의학회지
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    • 제16권3호
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    • pp.115-121
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    • 2021
  • PURPOSE: This study analyzed the correlation between the plantar pressure and body alignment according to the dominant hand of elementary school baseball players. METHODS: The subjects consisted of 32 elementary school baseball players. The 32 players were classified in the right-hand dominant group (Rt. Group, n = 22) and left-hand dominant group (Lt. group, n = 10). The plantar pressure was measured using a pedoscan to determine the maximum pressure and pressure distribution. The body alignment was measured using a fometric 4D to measure the trunk imbalance angle (TI), pelvic tilt angle (PTi), pelvic torsion angle (PTo), pelvis rotation angle (PR), kyphotic angle (Ky), lordotic angle (Lo), and trunk torsion angle (TT). RESULTS: Participants showed correlations in the Rt. group, according to the left maximum pressure, Lo (r = .592, p < .05), and TT (r = .514, p < .05); according to the right maximum pressure, PR (r = .539, p < .05), and Lo (r = .503, p < .05). In the left pressure distribution, the PR (r = -.521, p < .05) showed a negative correlation. In the Lt. group, the PT (r = -.591, p < .05) showed a negative correlation in the left pressure distribution. CONCLUSION: These results can be used as basic data for a body analysis study of elementary school baseball players in the future.

보행시 족저압 분포와 척추 측만의 상관관계 연구 (The study of correlation between foot-pressure distribution and scoliosis)

  • 박재현;장화선;정재우;노시철;최흥호
    • 센서학회지
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    • 제17권3호
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    • pp.210-216
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    • 2008
  • The propose of this study is evaluating which correlation of foot pressure distribution and scoliosis that happen by walking to 20'th Mens that have not experienced a scoliosis. The propose of this study is evaluating which correlation of foot pressure distribution and scoliosis that happen by walking to 20'th Mens that have not experienced a scoliosis. Measurement and analysis of Foot Pressure was executed by using by F-scan System. Degree of scoliosis was expressed as a angle used x-ray image of 5-lumbar from 4-thoracic vertebra The correlation between result of foot pressure and degree of scoliosis was evaluated under 0.05 interrelationship, and variables used for analysis were showed high correlation.

A Study on Correlation Between Pressure Variations and Augmentation of Heat Transfer in Acoustic Fields

  • Oh, Yool-Kwon;Yang, Ho-Dong
    • Journal of Mechanical Science and Technology
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    • 제18권9호
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    • pp.1630-1639
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    • 2004
  • The present paper investigated the correlation between the acoustic pressure variations and the augmentation of heat transfer in the ultrasonic induced acoustic fields. The augmentation ratios of heat transfer coefficient were experimentally measured and were compared with the profile of the pressure distribution in the acoustic fields predicted by numerical analysis. For numerical analysis, a coupled finite element-boundary element method (coupled FE-BEM) was applied. The results of the present study reveal that the acoustic pressure is higher near two ultrasonic transducers than other points where no ultrasonic transducer was installed. The augmentation trend of heat transfer is similar with the profile of the acoustic pressure distribution. In other words, as the acoustic pressure increases, the higher augmentation ratio of heat transfer is obtained. Numerical and experimental studies clearly show that the acoustic pressure variations are closely related to the augmentation of heat transfer in the acoustic fields.

비만인의 족저부 압력 분포 차이와 비만지표와의 상관성 연구 (A Study of the Correlation between Plantar Pressure and Obses Index in obses women.)

  • 소문기;임형호;송윤경
    • 척추신경추나의학회지
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    • 제2권1호
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    • pp.115-125
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    • 2007
  • Objectives : The limited number of studies to date have mainly focused on the effect of obesity on the characteristics of plantar foot pressures. This study is designed to find the correlation between plantar pressure and obese index. Methods : This study assessed the body composition of 30 obese women using bioelectrical impidence analysis and Gaitview AFA-50. The static and dynamic plantar pressure was determined from electronic footprints captured using a capacitive pressure distribution platform during standing and walking. The data were analysed by independent t-test and Pearson Correlation. Results : Positive correlations were noted between body weight, body mass index(BMI), waist circumference(WC), waist-hip ratio(WHR) and difference of fore and rear plantar pressure. And negative correlations were noted between body weight, BMI, WC, WHR and difference of left and right plantar pressure. Conclusions : The findings of this pilot study suggest that body composition influences the waight distribution in overweight and obese subjects.

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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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    • 제4권4호
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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.

고등학교 야구선수들의 신체정렬과 족저압 분포 간의 상관관계 분석 (Correlation between body alignment and foot pressure in high School Baseball Players)

  • 박치복;정호진;박성환
    • 한국산학기술학회논문지
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    • 제20권12호
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    • pp.224-229
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    • 2019
  • 본 연구는 고등학교 야구선수를 대상으로 신체정렬과 족저압 분포 분석하여 올바른 자세지도와 스포츠 손상 및 부상 예방 프로그램에 참고 자료를 제공하는데 그 목적이 있다. 연구 대상자 32명을 대상으로 실시하였다. 신체정렬은 척추에서 몸통의 좌우기울기, 등뼈의 뒤굽음각, 허리뼈의 앞굽음각, 골반에서는 골반의 기울기, 골반의 뒤틀림을 측정하였고 족저압은 각 발의 좌우 체중분포, 각 발의 최대압력을 측정하였다. 측정항목에 대한 평균과 표준편차를 산출하여 도표화하였고, 신체정렬과 족저압 분포의 상관관계를 알아보기 위해 pearson's cerrelation analysis를 사용하여 분석하였다. 모든 통계학적 유의 수준은 0.05로 설정하였다. 신체정렬과 족저압 분포 간의 상관관계를 분석한 결과 척추에서 허리뼈의 앞굽음각과 좌우 최대압력에서 양의 상관관계가 나타났다. 몸통의 좌우기울기, 등뼈의 뒤굽음각, 골반의 기울기, 골반의 뒤틀림과 각 발의 좌우 체중분포, 각 발의 최대압력에서는 상관관계가 나타나지 않았다. 본 연구를 통해 허리뼈의 앞굽음각이 증가될수록 발의 한쪽에 힘이 더 실리게 되어 최대압력이 증가하는 양의 상관관계를 나타내는 것을 알 수 있었다. 향후 운동선수들의 신체정렬과 족저압 분포에 대한 운동프로그램의 참고 자료가 될 것으로 사료된다.

3차원 고세장비 공동 주위의 난류유동 및 음향 특성에 관한 수치적 연구 (NUMERICAL ANALYSIS FOR TURBULENT FLOW AND AERO-ACOUSTIC OVER A THREE DIMENSIONAL CAVITY WITH LARGE ASPECT RATIO)

  • 문바울;김재수
    • 한국전산유체공학회:학술대회논문집
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    • 한국전산유체공학회 2008년도 학술대회
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    • pp.297-301
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    • 2008
  • The flight vehicles have cavities such as wheel wells and bomb bays. The flow around a cavity is characterized as unsteady flow because of the formation and dissipation of vortices due to the interaction between the freestream shear layer and cavity internal flow, the generation of shock and expansion waves. Resonance phenomena can damage the structures around the cavity and negatively affect aerodynamic performance and stability. The flow field is observed to oscillate in the "shear layer mode" with low aspect ratio. In the present study, numerical analysis was performed for cavity flows by the unsteady compressible three dimensional Reynolds-Averaged Navier-Stokes (RANS) equations with Wilcox's $\kappa$-$\omega$ turbulence model. The flow field is observed to oscillate in the shear layer mode" with large aspect ratio. Based on the SPL(Sound Pressure Level) analysis of the pressure variation at the cavity trailing edge, the dominant frequency was analyzed and compared with the results of Rossiter's formul. The aero-acoustic wave analyzed with CPD(Correlation of Pressure Distribution).

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3차원 고세장비 공동 주위의 난류유동 및 음향 특성에 관한 수치적 연구 (NUMERICAL ANALYSIS FOR TURBULENT FLOW AND AERO-ACOUSTIC OVER A THREE DIMENSIONAL CAVITY WITH LARGE ASPECT RATIO)

  • 문바울;김재수
    • 한국전산유체공학회:학술대회논문집
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    • 한국전산유체공학회 2008년 추계학술대회논문집
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    • pp.297-301
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    • 2008
  • The flight vehicles have cavities such as wheel wells and bomb bays. The flow around a cavity is characterized as unsteady flow because of the formation and dissipation of vortices due to the interaction between the freestream shear layer and cavity internal flow, the generation of shock and expansion waves. Resonance phenomena can damage the structures around the cavity and negatively affect aerodynamic performance and stability. The flow field is observed to oscillate in the "shear layer mode" with low aspect ratio. In the present study, numerical analysis was performed for cavity flows by the unsteady compressible three dimensional Reynolds-Averaged Navier-Stokes (RANS) equations with Wilcox's ${\kappa}-{\varepsilon}$ turbulence model. The flow field is observed to oscillate in the "shear layer mode" with large aspect ratio. Based on the SPL(Sound Pressure Level) analysis of the pressure variation at the cavity trailing edge, the dominant frequency was analyzed and compared with the results of Rossiter's formul. The aero-acoustic wave analyzed with CPD(Correlation of Pressure Distribution).

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INFLUENCE OF INITIAL COMBUSTION IN SI ENGINE ON FOLLOWING COMBUSTION STAGE AND CYCLE-BY-CYCLE VARIATIONS IN COMBUSTION PROCESS

  • Lee, Kyung-Hwan;Kim, Kisung
    • International Journal of Automotive Technology
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    • 제2권1호
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    • pp.25-31
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    • 2001
  • It is necessary to understand the combustion process and cycle-by-cycle variation in combustion to improve the engine stability and consequently to improve the fuel economy and exhaust emissions. The pressure related parameters instead of mass fraction burned were compared for the effect of initial combustion pressures on the following combustion and the analysis of cycle-by-cycle variation in combustion for two pen injected SI engines. The correlation between IMEP and pressures at referenced crank angles showed almost the same trends for equivalence ratios, but the different mixture preparations indicated different tendency. The dependency of IMEP on pressure at the referenced crank angles increases as the mixture becomes leaner for both engines. The mixture distribution in the combustion chamber was varied with the coolant temperature and intake valve deactivation due to the evaporation of fuel and air motion. The correlation between pressure related parameters were also compared for the coolant temperatures and air motion.

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필댐의 안전관리를 위한 주요 계측 데이터의 최적 분석기법에 대한 사례 연구 (A case study on an optimal analysis technique of primary measurements for safety management of fill dam)

  • 전현철;윤성규;김지성;임은상;강기천
    • 한국수자원학회논문집
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    • 제54권spc1호
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    • pp.1155-1166
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    • 2021
  • 본 연구에서는 필댐의 주요계측기인 침투수량계, 정상침하계, 간극수압계의 최적 분석기법을 제안하기 위해 통계분석을 수행하였고, 이와 더불어 저수위, 강우량 데이터와의 상관관계 분석을 수행하였다. 계측기별 기술통계 분석 결과를 토대로 간극수압계는 주성분 분석을 통해 3그룹 또는 2그룹으로 분류가 가능하였고, 저수위가 상관성이 큰 그룹의 경우는 계측기 간의 상관성도 크게 나타났다. 침투수량의 경우는 극심한 비대칭 분포를 보이고 있어 정량적 분석을 위해 분류나무 분석을 통해 무강수, 강수시의 평균 침투수량을 추정할 수 있었다. 정상침하계의 경우는 상관분석 결과 계측기간의 상관성은 큰 것으로 나타났지만, 저수위계와의 관계에서는 유의미한 선형관계를 나타내지 못하여 이를 보다 상세히 분석하기 위해 EMD분석을 수행 하였다. 필댐의 주요 계측항목으로 간극수압계, 침투수량계, 정상침하계의 거동분석을 위해서는 각각 주성분 분석, 분류나무 분석, 데이터 필터 기법을 적용이 가능할 것으로 판단되며, 향후 유사한 계측항목에 적용이 가능할 것으로 판단된다.