• 대한의용생체공학회:의공학회지
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• 제21권2호
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• pp.213-218
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• 2000

Pressure distributions of the soft tissue are valuable for understanding and diagnosing the disease characteristics due to the mechanical loading. Our system measures dynamic pressure distributions in real-time under the general PC environment, and analyzes various foot disorders. Main features of the developed system are as follows: (1) With the resistive pressure sensor matrix of 40${\times}$40 cells, the data is sent to the PC with the maximum sampling rate of 40 frames/sec. (2) For each frame, contact area, pressure and force are analyzed by graphic forms. Thus, various biomechanical parameters are easily determined at specific areas of interests. (3) A certain stance phase can be chosen for the analysis from the continuous walking, and the detailed biomechanical analysis can be done according to an arbitrary line dividing anterior/posterior or medial/lateral plantar areas. (4) The center of pressure (COP) is calculated and traced from the pressure distribution data, and thus the movement of the COP is monitored in detail. A few experiments revealed that our system successfully measured the dynamic plantar distribution during normal walking.

• The Journal of Korean Physical Therapy
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• 제21권4호
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• pp.43-49
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• 2009

Purpose: This study examined the dynamic peak plantar pressure under the foot areas in those with a functional leg length inequality. Methods: The dynamic peak plantar pressure under the foot areas in an experimental group with a functional leg length inequality (n=20) and a control group (n=20) was assessed a using the Mat-Scan system (Tekscan, USA). The peak plantar pressure under the hallux, 1st, 2nd, 3-4th and 5th metatarsal head (MTH), mid foot, and heel was measured while the subject was walking on the Mat-Scan system. Results: The experimental group had significantly higher peak plantar pressure under all foot areas when the dynamic peak plantar pressure in the short leg and long leg sides was compared. The control group had a significantly higher peak plantar pressure under the 1st, 2nd, 3-4th, and 5th MTH when the dynamic peak plantar pressure in the short leg and long leg sides were compared. The experimental group showed a significantly larger difference in the dynamic peak plantar pressure under the hallux, 1st, 2nd, 3-4th and 5th MTH, mid foot and heel than the control group. Conclusion: A functional leg length inequality leads to an increase in the weight distribution and dynamic peak plantar pressure in the side of the short leg.

• 한국산학기술학회논문지
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• 제20권6호
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• pp.150-157
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• 2019

본 연구의 목적은 장딴지근 길이가 동적 균형과 발의 앞뒤 압력분포에 어떤 영향을 미치는지 알아보는 것이다. 연구기간은 2018년 12월 3일부터 21일까지로 30명의 연구대상자를 장딴지근 길이 검사를 통해 장딴지근의 정상길이를 가진 대조군과 장딴지근 길이의 단축이 있는 실험군으로 분류하였다. 동적 균형과 발의 앞뒤 압력분포는 Biorescue장비를 사용하여 평가하였으며 동적 균형을 평가하기 위해 앞쪽과 뒤쪽 방향의 안정성 한계를 데이터로 수집하였다. 군간 동적 균형과 발의 앞뒤 압력분포에 유의한 차이가 있는지 알아보기 위하여 독립 t 검정을 이용하여 분석하였고, 통계학적 유의수준은 0.05로 하였다. 연구 결과 군간 동적 균형과 발의 앞뒤 압력분포는 유의한 차이가 있었다(p<0.05). 이러한 연구 결과를 통해 장딴지근 길이의 단축은 앞쪽으로 동적 균형 및 발의 앞쪽 압력 분포에 영향을 미친다는 것을 제안하고 그러므로 근골격계 질환 예방과 정상적인 균형능력을 위해 장딴지근의 적절한 길이를 유지하는 것은 중요하다.

• 한국지진공학회논문집
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• 제27권5호
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• pp.193-202
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• 2023

In this paper, a dynamic centrifuge model test was conducted on a 24.8-meter-deep excavation consisting of a 20 m sand layer and 4.8 m bedrock, classified as S3 by Korean seismic design code KDS 17 10 00. A braced excavation wall supports the hole. From the results, the mechanism of seismically induced earth pressure was investigated, and their distribution and loading points were analyzed. During earthquake loadings, active seismic earth pressure decreases from the at-rest earth pressure since the backfill laterally expands at the movement of the wall toward the active direction. Yet, the passive seismic earth pressure increases from the at-rest earth pressure since the backfill pushes to the wall and laterally compresses at it, moving toward a passive direction and returning to the initial position. The seismic earth pressure distribution shows a half-diamond distribution in the dense sand and a uniform distribution in loose sand. The loading point of dynamic thrust corresponding with seismic earth pressure is at the center of the soil backfill. The dynamic thrust increased differently depending on the backfill's relative density and input motion type. Still, in general, the dynamic thrust increased rapidly when the maximum horizontal displacement of the wall exceeded 0.05 H%.

• 대한수학회논문집
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• 제16권1호
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• pp.137-152
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• 2001

Steady two-dimensional flows due to an applied pressure distribution in water of finite depth are considered. Gravity is included in the dynamic boundary condition. Gravity is included in the dynamic boundary condition. The problem is solved numerically by using the boundary integral equation technique. It is shown that, for both supercritical and subcritical flows, solutions depend on three parameters: (i) the Froude number, (ii) the magnitude of applied pressure distribution, and (iii) the span length of pressure distribution. For supercritical flows, there exist up to two solutions corresponding to the same value of Froude number for positive pressures and a unique solution for negative pressures. For subcritical flows, there are solutions with waves behind the applied pressure distribution. As the Froude number decreases, these waves when the Froude numbers approach the critical values.

• 대한인간공학회지
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• 제22권3호
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• pp.57-73
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• 2003

Although body pressure distribution is sensitive to movements and is relatively simple to measure even in small space, there are few researches involving applications to driver's posture and its change. The main objective in this study is the application of body pressure distribution measurements for the prediction of the driver's posture and its change. This requires quantitative analyses of the dynamic body pressure distribution, which is the change of body pressure distribution with time. The experiment involved 16 male subjects who drove for 45 minutes in a seating buck. Measurement time, stature group, and lumbar support prominence were selected as independent variables, with subjective ratings of driver's discomfort, body posture data of hip, torso. knee angle, and body pressure data variables as dependent variables. The body pressure change variables and subjective ratings were found to increase as the measurement time increased and body pressure ratio variables reflected the torso angle. From the results and analysis of the body posture data and subjective rating results, it was predicted that the seats and the design of the lumbar supports used in the experiment was not fit for tall subjects, which could also be confirmed through the body pressure distribution data.

• 대한의용생체공학회:의공학회지
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• 제18권4호
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• pp.439-446
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• 1997

증가하고 있는 주요 족부질환인 엄지발가락외반증의 특성을 이해하기 위하여 본 연구를 수행하였다.23명의 엄지발가락외반증 환자들에 관한 방사선학적 연구와 함께 자유보행시의 족저압력분포를 측정하였다. 또한 본 연구에서는 족저압력 분포를 상세히 분석하기 위한 해부학적으로 적절한 구역설정을 제시하였다. 족저압력분포를 측정한 결과, 엄지발가락외반증이 심한 환자일수록 중족골 부위의 압력, 접촉면 적과 시간, 충격량 등이 현저하게 증가함을 알 수 있었다. 엄지발가락외반증은 신발의 선정이 잘못됨에 의하는 경우가 적지 않았다. 족저압력집중은 족부질환에 있어서 매우 중요하므로, 신발의 설계에 있어서 적절한 족저압력분포를 고려하여야 한다.

• International Journal of Naval Architecture and Ocean Engineering
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• 제8권2호
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• pp.153-168
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• 2016

Sloshing phenomenon is a complicated free surface flow problem that increases the dynamic pressure on the sidewalls and the bottom of the storage tanks. When the storage tanks are partially filled, it is essential to be able to evaluate the fluid dynamic loads on the tank's perimeter. In this paper, a numerical code was developed to determine the pressure distribution on the rectangular and trapezoidal storage tanks' perimeters due to liquid sloshing phenomenon. Assuming the fluid to be inviscid, the Laplace equation and the nonlinear free surface boundary conditions were solved using coupled boundary element - finite element method. The code performance for sloshing modeling was validated using Nakayama and Washizu's results. Finally, this code was used for partially filled rectangular and trapezoidal storage tanks and free surface displacement, pressure distribution and horizontal and vertical forces exerted on the tanks' perimeters due to liquid sloshing phenomenon were estimated and discussed.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 1997년도 춘계학술대회 논문집
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• pp.244-249
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• 1997

Internal and external heat sources will cause to deform to machine elements in the contact joint of structure,which results in the change of contact pressure distribution different from initial assembly. Heat induced variations of contact pressure will change the static and dynamic properties such as contact stiffness,damping as well as contact heat conduction in the structure. In order to design and control the intelligent machine tool operating in variant conditions more sophisticatedly, the good prediction for the changes of prescribed propeties are strongly required especially in the contact elements adjacent to the rotational or linear bearing This paper presents some computational and experimental results in regard to static and dynamic characteristics of the press-fitted bush and shaft assembly which is a model of the bearing innerrace and shaft assembly. In the condition of heat generation on the outer surface of the bush,the effects of changes in the negative clearance and the heat flux on pressure distribution and dynamic properties are investigated. Results of this study show that the edge effect of the bush and the initial clearance have effects on the transient dynamic characteristics significantiy.

• The Journal of Korean Physical Therapy
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• 제22권1호
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• pp.47-51
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• 2010

Purpose: The purpose of this study was to determine whether there are any differences, with and without a toe spreader (TS), in dynamic foot pressure distribution in children with spastic diplegic cerebral palsy. Methods: Dynamic foot pressure recording using the RSscan system were obtained during walking in 12 participants (male=7, female=5) with and without TS. Mean force was measured for four different plantar regions; great toe, forefoot, midfoot, hindfoot. Displacement of center of pressure (COP), velocity of COP displacement and stance time were also measured during gait. Results: TS walking exhibited statistically significant decrease of mean force under great toe and forefoot (p<0.05), compared with a barefoot walking. Also, TS walking exhibited statistically significant increase of antero-posterior displacement of COP (p>0.05). Conclusion: These findings indicate the potential clinical utility of toe spreader to correct dynamic foot pressure during stance phase in children with spastic diplegic cerebral palsy.