• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2006년도 춘계 학술발표회 논문집
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• pp.1038-1045
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• 2006

The Green Wall is highest eco-system among a segmental retaining wall systems. Recently, the demand of high segmental retaining wall (SRW) is increased in domestic. The soil nailing system is applied in order to maintain the high SRW stability for steeper slope. However, the proper design approach that can consider the earth pressure reduction effects in soil nailing system has not been proposed. This study was performed to introduce the design case by 'Two-Body Translation mechanism' to be able to consider distribution of earth pressure in the soil nailing when designing the green wall using soil nailing system. Also, this study attempts to evaluate the earth pressure change when advanced soil nailing system is constructed using $FLAC^{2D}$ ver. 3.30 program and 'Two-Body Translation mechanism'. Also in this study, various parametric studies using numerical methods as shear strength reduction (SSR) technique and limit equilibrium technique were carried out. In the parametric study, the length ratio and the bond ratio of the soil nailing were changed to identify the earth pressure reduction effect of the retaining wall reinforced by soil nailing.

• International Journal of Aeronautical and Space Sciences
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• 제18권1호
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• pp.70-81
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• 2017

Various components of an engine nozzle are modeled as flexible multi-body components that are operated under high temperature and pressure. In this paper, in order to predict complex behavior of an engine nozzle, thermo-fluid-flexible multi-body dynamics coupled analysis framework was developed. Temperature and pressure on the nozzle wall were obtained by the steady-state flow analysis for a two-dimensional nozzle. The pressure and temperature-dependent material properties were delivered to the flexible multi-body dynamics analysis. Then the deflection and strain distribution for a nozzle configuration was obtained. Heat conduction and thermal analyses were done using MSC.NASTRAN. The present framework was validated for a simple nozzle configuration by using a one-way coupled analysis. A two-way coupled analysis was also performed for the simple nozzle with an arbitrary joint clearance, and an asymmetric flow was observed. Finally, the total strain result for a realistic nozzle configuration was obtained using the one-way and two-way coupled analyses.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2001년도 춘계학술대회논문집E
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• pp.223-228
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• 2001

This study was obtained the pressure distribution of a falling body that is deadrise angle $0^{\circ}$ and deadrise angle $5^{\circ}$ upon a water surface by the experiment with the impact machine. The theoretical equation was obtained the air region and the interface and the water region which devide 3 parties between the body and the water surface for an investigation of the complete phenomena. Pressure distributions and histories compare favorably with available experimental data. The numerical results are similar to the experimental results for the impact force type with $Fo(1+cos{\pi}t/tc)$.

• 대한인간공학회지
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• 제30권4호
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• pp.495-501
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• 2011

The objective of this study was to evaluate the convenience of the tractor seatbelt. We selected four healthy men as subjects. We measured their body pressure and examined the comfort of the seatbelt, while driving 50m on three different types of agricultural road with two types of seatbelts: automatic and manual. As results, when they used manual seatbelt, subjective uncomfortable rate was much higher than the automatic seatbelt on all types of road. Especially, body pressure was undistributed while using manual seatbelt on rough road.

• 대한인간공학회지
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• 제24권4호
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• pp.23-30
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• 2005

The mailman's shoes should be designed in due consideration of occupational features they spend most of times to walk. For that reason, the shoes required functions to reduce the foot fatigue and to protect body by dispersing the body weight to the whole foot. In this research, for the functional improvement of the insole, insoles are investigated and analyzed by biomechanics experimentation. Under the base of these experimental results, we develop insoles that can reduce the body load and muscular-skeletal disorder. The pressures are concentrated on the metatarsus and heel by the result of analyzing pressure distributions of the using shoes. Accordingly, we offer the prototype functional insole that is ranked from high pressure to low pressure on the base of a shock absorb function. This prototype functional insole is examined for statistical significance by pressure distribution areas. The experimental results show that pressure areas are dispersed to whole foot, for this reason, pressures of the metatarsus and heel are reduced. Results of this research can not only improve the function of insoles which is suitable for occupational features, but also be a base on constructing data bases for biomechanics gait insoles.

• 한국산학기술학회논문지
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• 제20권6호
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• pp.402-409
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• 2019

치매 환자나 혼자 힘으로 전혀 움직이지 못하는 노인 환자는 간병 인력 부족으로 낙상 사고 및 욕창 발생 가능성이 매우 크다. 본 논문에서는 이러한 문제를 해결하기 위해 일정 주기마다 감지한 압력 세기를 기준으로 머리, 어깨, 엉덩이 등 주요 신체 부위를 판별하여 환자의 누운 자세를 판별할 수 있는 알고리즘을 제안한다. 신체적 특성에 무관하게 신체 부위 판별이 가능하도록 격자 구조로 압력 센서를 배치한 스마트 매트를 제작하였다. 스마트 매트는 $7{\times}7$ 배열 크기의 2개 모듈을 조합하여 구성하였다. 각 모듈은 모두 49개의 FSR-406 센서로 구성되며 독립적으로 압력을 감지한다. 각 모듈에 대해 필터를 사용한 누적 압력 합 등 압력 분포를 이용해 상체 또는 하체에 해당하는 신체 부위를 순차적으로 판별한다. 제안한 알고리즘은 머리, 어깨, 엉덩이 부위 등 계층-1에 속한 신체 부위간 포함 관계를 조사해 5가지 누운 자세를 판별할 수 있다.

• Structural Engineering and Mechanics
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• 제70권4호
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• pp.479-497
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• 2019

In the current code design, the use of a uniform internal pressure coefficient of cooling towers as internal suction cannot reflect the 3D characteristics of flow field inside the tower body with different ventilation rate of shutters. Moreover, extreme weather such as heavy rain also has a direct impact on aerodynamic force on the internal surface and changes the turbulence effect of pulsating wind. In this study, the world's tallest cooling tower under construction, which stands 210m, is taken as the research object. The algorithm for two-way coupling between wind and rain is adopted. Simulation of wind field and raindrops is performed iteratively using continuous phase and discrete phase models, respectively, under the general principles of computational fluid dynamics (CFD). Firstly, the rule of influence of 9 combinations of wind speed and rainfall intensity on the volume of wind-driven rain, additional action force of raindrops and equivalent internal pressure coefficient of the tower body is analyzed. The combination of wind velocity and rainfall intensity that is most unfavorable to the cooling tower in terms of distribution of internal pressure coefficient is identified. On this basis, the wind/rain loads, distribution of aerodynamic force and working mechanism of internal pressures of the cooling tower under the most unfavorable working condition are compared between the four ventilation rates of shutters (0%, 15%, 30% and 100%). The results show that the amount of raindrops captured by the internal surface of the tower decreases as the wind velocity increases, and increases along with the rainfall intensity and ventilation rate of the shutters. The maximum value of rain-induced pressure coefficient is 0.013. The research findings lay the basis for determining the precise values of internal surface loads of cooling tower under extreme weather conditions.

• 한국의학물리학회지:의학물리
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• 제32권4호
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• pp.153-158
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• 2021

Purpose: This study evaluated the features of a pressure mapping system for patient motion monitoring in radiation therapy. Methods: The pressure mapping system includes an MS 9802 force sensing resistor (FSR) sensor with 2,304 force sensing nodes using 48 columns and 48 rows, controller, and control PC (personal computer). Radiation beam attenuation caused by pressure mapping sensor and signal perturbation by 6 and 10 mega voltage (MV) photon beam was evaluated. The maximum relative pressure value (mRPV), average relative pressure value (aRPV), the center of pressure (COP), and area of pressure distribution were obtained with/without radiation using the upper body of an anthropomorphic phantom for 30 minutes with 15 MV. Results: It was confirmed that the differences in attenuation induced by the FSR sensor for 6 and 10 MV photon beams were small. The differences in mRPV, aRPV, area of pressure distribution with/without radiation are about 0.6%, 1.2%, and 0.5%, respectively. The COP values with/without radiation were also similar. Conclusions: The characteristics of a pressure mapping system during radiation treatment were evaluated on the basis of attenuation and signal perturbation using radiation. The pressure distribution measured using the FSR sensor with little attenuation and signal perturbation by the MV photon beam would be helpful for patient motion monitoring.

• 대한산업공학회지
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• 제25권1호
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• pp.75-86
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• 1999

The improvement of automotive seating system, particularly for the driver, has been the subject of intense interest. In this study, the methods for evaluating the seating comfort are investigated. A subjective evaluation has been the general method for evaluating the seating comfort of automotive seat. Therefore, the survey using the roadside interview is conducted. In addition, the subjective evaluation with a questionnaire using the laboratory set-up is investigated. With this subjective evaluation, in order to evaluate the comfort objectively, the body pressure distribution, seat physical characteristics and eletromygram are investigated. These objective evaluation methods are compared with the subjective evaluation. As a result, the body pressure distribution, seat physical characteristics and electromyogram are recommended as the objective technique for the seating comfort evaluation.

• 대한기계학회논문집
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• 제5권4호
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• pp.354-361
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• 1981

This study aims to compare stress concentratior factors in a loaded elastic body of the infinite plate with pressure coefficients of a fluid in the potential flow. First in view of hydrodynamics, when a single elliptic cylinder in the form of a bluff body stands in the potential flow, the pressure distribution(doefficient, C$\_$p/around the elliptic cylicder which is changed according to the position(angular displacements)is theoretically analyzed and calulated; secondly, in view of theory of elasticity, when an eliptic hole which is made on a flat plate gets tension, the stress distribution(factor) around the elliptic hole which is changed according to the position(angular displacements )is theoretically(K$\_$t/) and experimentally (K$\_$e/) measured; and finally. The results are compard and examined.