• 대한통합의학회지
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• 제1권2호
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• pp.37-46
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• 2013

Purpose : The purpose of the research was to analyze foot pressure, foot temperature, and correlation between foot pressure and foot temperature to grasp impact on foot pressure and body temperature distribution chart depending on functional difference of leg length. Method : After measuring leg length, put 15 students whose functional difference of leg length was over 10mm to difference group and 15 students whose functional difference of leg length was under 5mm to normal group and categorize soles of foot into 6 sections of hallux head, 1st metatarsal head, 2-4 metatarsal head, 5 metatarsal head, lateral heel, and then measure by foot pressure analyzer to analyze characteristic of pressure distribution and classify into front of the lower leg, back of the lower leg, soles of foot and measure by body temperature analyzer to analyze by checking body temperature. Result : Weight difference depending on foot pressure and body temperature was bigger when functional difference of leg length was bigger, and it could be confirmed that foot pressure and body temperature of short leg side were higher than those of short leg side. Thus, if difference exists in leg length, weight load on short leg side increases which results in higher foot pressure and body temperature, therefore enabling an assumption that mechanical problem will occur in short leg. Conclusion : When functional leg length inequality, weight bearing and pressure was getting high as a result, temperature was getting high in short leg.

• Journal of Advanced Marine Engineering and Technology
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• 제34권5호
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• pp.695-702
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• 2010

Numerical analysis information will be very useful to improve fluid system. General information about an internal gas flow is presented by numerical analysis approach. Relating with hydrogen compressing system, which have an important role in hydrogen energy utilization, this should be a useful tool to observe the flow quickly and clearly. Flow characteristic analysis, including pressure and turbulence kinetic energy distribution of hydrogen gas coming to the cylinder of a reciprocating compressor are presented in this paper. Suction-passage model is designed based on real model of hydrogen compressor. Pressure boundary conditions are applied considering the real condition of operating system. The result shows pressure and turbulence kinetic energy are not distributed uniformly along the passage of the Hydrogen system. Path line or particles tracks help to demonstrate flow characteristics inside the passage. The existence of vortices and flow direction can be precisely predicted. Based on this result, the design improvement, such as reducing the varying flow parameters and flow reorientation should be done. Consequently, development of the better hydrogen compressing system will be achieved.

• 태양에너지
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• 제18권3호
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• pp.217-228
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• 1998

축류비가 5이고 형상비가 7인 장방형(長方形) 노즐을 사용하여 연직 상향의 3차원 자유 충돌 수분류계를 구성하였다. 수평 충돌판에 상향의 장방형 충돌수분류가 충돌할 때, 보조수를 동반하지 않은 단일수분류 및 보조수를 동반하는 수분류에 대하여 노즐-충돌판 사이의 거리, 노즐출구 속도를 변수로하여 노즐의 긴변 방향과 짧은 변 방향에 대하여 전압 및 정압 분포를 측정하였다. 이때 충돌판상에서 정압이 영이 되는 국소 위치까지의 거리인 충돌 반폭을 구하고, 최고 압력을 나타내는 정체점을 기준으로 무차원 정압 분포식을 제시하였다. 또한 각 실험조건에서 정체점상에서의 충돌속도를 구하였으며, 충돌속도는 노즐-전열면간 거리가 증가함에 따라 감소하며 그 감쇄율은 삼차원 자유 분류의 특성감쇄 영역의 유동 특성을 갖는다.

• 한국안전학회지
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• 제20권1호
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• pp.36-41
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• 2005

PCV(Positive Crankcase Ventilation) valve acts as a flow control valve to get a re-combustion of blow-by gas by having it flow from a crankcase to an inlet manifold suction tube. The blow-by gas of the crankcase should be eliminated or taken properly because it cause corrosion to critical parts, and contributes to increase crankcase pressure that can cause a drop in efficiency. The excessive stress and strain on the PCV valve that remove these harmful gas would be bring the difficult on the flow rate control and failure of the valve. Those condition inevitably induce the accident. Therefore, this study purpose is FEM evaluation of the stresses and deformation in the X3 PCV model according to the change of the differential pressure between inlet and outlet. From results, the maximum equivalent stresses increased linearly according to the increase of the differential pressure at the about 50mm from the inlet position and were under the yield strength of the valve. And the deformations were relatively small regardless of the in-outlet differential pressure variation.

• 상하수도학회지
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• 제9권2호
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• pp.84-96
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• 1995

The dewatering characteristics of the sewage sludge was investigated through the experimental observations and model simulations. The activated sludge and the anaerobically digested sludge were examined for the dewaterability evaluation within the pressure range of $0{\sim}10^6N/m^2$. Modified Buchner funnel test and compression test by the consolidometer were conducted to evaluate average specific resistance, porosity, and moisture percentage of filter cake. Shirato's technique of compression-permeability test was followed for the pressure range lower than about $10^2N/m^2$. The flocculation effects on sludge dewatering was also examined for ferric chloride and polymeric flocculant. The application of hydrated lime which can be used for flue-gas desulfurization showed improved moisture percentage, and was thought to have positive feasibility in combined system of sludge dewatering and incineration. Determined characteristic constants were applied to Tiller's cake filtration model to simulate liquid pressure distribution and porosity distribution in cake. Model simulations showed a sharp drop of the porosity close to the cake-medium interface for the highly compressible material such as the activated sludge and the anaerobically digested sludge.

• Tribology and Lubricants
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• 제21권6호
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• pp.249-255
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• 2005

In this paper, the friction characteristic of engine bearings has been analyzed in terms of a friction loss power, a minimum film thickness and an oil film pressure. This analysis has been focused on the fuel economy improvement with a low viscosity engine oil such as SAE 0W-40, which is used for a friction loss reduction and increased for a Diesel fuel economy. The friction loss power, the minimum oil film thickness and oil film pressure distribution for plain bearings of a Diesel engine are analyzed using an AVL's EXCITE program with a conventional engine oils of SAE 5W-40 and 10W-40, and a low viscosity engine oil of SAE 0W-40. The computed results indicate that a viscosity of engine oils is closely related to the friction loss power and the decreased minimum film thickness in which is a key parameter of a load carrying capacity of an oil film pressure distribution. When the low viscosity engine oil is supplied to engine bearings, it does not affect to the formation of a minimum oil film thickness. But the friction loss power has been significantly affected by low viscosity engine oil at a low operating temperature of 0. Based on the FEM computed results, the low viscosity engine oil at a low temperature range will be an important factor for an improvement of the fuel economy improvement.

• The Journal of Korean Physical Therapy
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• 제29권4호
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• pp.218-222
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• 2017

Purpose: Driving is an important activity that is affected by various motor and cognitive deficits after stroke. On the other hand, there is no standard screening tool to evaluate the sitting asymmetry during driving, which is the stereotyped postural characteristic observed in patients with stroke. Therefore, this study compared the buttock pressure during simulated driving between healthy adults and patients with stroke. Methods: Ten post-stroke patients and ten healthy subjects participated in the experiment. The participants experienced simulated driving of 6.1 km during approximately 5 minutes for adaptation. The driving scenario consisted of 3.5 km urban traffic conditions, 10 km straight highway, and 7 km curved or hilly rural roads. Force sensitive application (FSA) was used to analyze the distribution of the buttock pressure on the driver's seat. The symmetry index (SI) was determined using the average buttock pressure of each side of the buttock. The closer SI is to zero, the higher the symmetry of buttock pressure. Results: These studies showed that the SI of healthy subjects was significantly closer to zero than that of the stroke patients. Conclusion: The buttock pressure of the stroke patients showed more asymmetry than that of the healthy subjects during simulated driving. Therefore, a therapeutic approach is needed for symmetrical sitting to improve the driving performance.

• 한국표면공학회지
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• 제24권3호
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• pp.119-124
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• 1991

Recently, the trend of research in hard coating is concentrate on developing the process of ionization rate under low operating pressure, to get the thin film with high adhesion and dense microstructures. In this study ionization rate enhancement type PVD process using permanent magnet is developed, which enhances the ionization rate by confining the plasma suppressing the wall loss of electron. By the result to investigate the characteristic of glow discharge, the ionization rate of this process is enhanced about twice as high as that of triod BARE process (about 26%), and more dense TiN microstructures are obtained in this process. Cylindrical ion energy analyzer is made and attached in front of a quadrupole mass filter for the analysis of the energy distribution of reactive gas and activated gas ions from the plasma zone. To analyze the operation mechanism of ion energy analyzer, computer simulation is performed by calculation the electric field environment using finite element method. By these analyses of ion energy distribution of outcoming ions from the plasma zone, it is found that magnetic field enhances ion kinetic energy as well as ionization rate. The other results of this study is that the foundation of feed-back system is constructed, which automatically control the partial pressure of reactive gas. In can be possible by recording the data of mass spectrum and ion energy analysis using A-D converter.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2003년도 춘계학술대회
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• pp.1942-1947
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• 2003

The valve is the key part which governs the efficiency, noise and reliability of the compressor, so the development of analytical model about valve performance is necessary. As the valve leed is opened and closed by pressure pulsation, the flow characteristic of the refrigerant passing the valve is very important. In the present study, a circular disk with inclination is assumed to be the valve reed of a reciprocating compressor and numerical analysis of three dimensional velocity fields are perfomed for the radial flow through the valve model. The effective flow and force area which are required to predict the efficiency of the valve are measured and compared with the numerical analysis in this research.

• 대한기계학회논문집B
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• 제31권4호
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• pp.376-383
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• 2007

This research represents the catalytic converter for application in the motorcycle. We have to consider about catalytic converter for reducing exhaust gas strength regarding the displacement volume enlargement. The catalytic converter has been widely used to satisfy the regulations of pollutant emissions from automobiles. Recently, all catalytic converter researches are about automobile. Study about motorcycle catalytic converter has not been conducted yet. In this study, flow uniformity and pressure distribution were simulated in the monolithic inlet of catalytic converter for motorcycle. Exhaust pulsation pressure was set as transient condition about. It was found that flow uniformity shown in base model (0.85) was lower than megaphone model (0.98).