• 혜화의학회지
• /
• 제14권1호
• /
• pp.59-65
• /
• 2005

One case of patient with adult polycystic kidney disease was reported in this clinical study. After the study, the results were as follows: The adult polycystic kidney disease(APCK) is inheritant disease in which cysts are distributed throught the cortex and medulla of both kidneys. It belongs to Hematuria in oriental medicine field. For this patient, it was effective to appliment acupuncture Hap-kok, Kok-chi, Oe-gwan, Chok-samni, Chok-imup, Sam-umgyo, Su-bun, Tae-chung and Hae-gye showed a great effect on decreasing the pain and increasing the volume of urine. For this patient, it was effective to dispense Gamiwuiryungtang(加味胃苓湯), Ohryungsan(五苓散) and Chungsimyeonjaeum(淸心蓮子飮), Dosubokryungtang(導水茯苓湯).

• 태양에너지
• /
• 제20권3호
• /
• pp.75-84
• /
• 2000

The purpose of this research is to study on the heat transfer characteristics of separate type heat pipe with a rotor. The heat transfer characteristics of the rotor condenser are various on input heat of evaporator, rotational speeds of rotor, and working fluid amount. The results obtained from the study are as follows. 1. Magnetic fluid using seal of the rotor operated in stability by a variation of temperature and rotation speeds. The configuration of magnetic fluid seal assembly was adequate. 2. Steam ejector is effective in recovering working fluid condensate in the rotor. When steam ejector is operating, the heat flux of working fluid does not change, with the wall temperature in the rotor. 3. The optimum design conditions on working fluid amount and rotational speeds are effective in evaporator volume 50%, rotational speeds 200rpm, 300rpm, and operating temperature $80^{\circ}C$. With working fluid amount increasing, overall heat transfer coefficient decreases linearly.

• International Journal of Automotive Technology
• /
• 제8권2호
• /
• pp.233-241
• /
• 2007

A lumped parameter model is proposed for the analysis of dynamic behaviour of a Passive Hydraulic Engine Mount (PHEM), incorporating inertia track and throttle, which is characterized by effective and efficient vibration isolation behaviour in the range of both low and high frequencies. Most of the model parameters, including volume compliance of the throttle chamber, effective piston area, fluid inertia and resistance of inertia track and throttle are identified by an experimental approach. Numerical predictions are obtained through a finite element method for responses of dynamic stiffness of the rubber spring. The experiments are made for the purpose of PHEM validation. Comparison of numerical results with experimental observations has shown that the present PHEM achieves good performance for vibration isolation.

• 소성∙가공
• /
• 제10권1호
• /
• pp.35-41
• /
• 2001

The high temperature deformation behavior of SCM 440 can be characterized by the hot torsion test in the temperature ranges of $900^{\circ}C$~$1100^{\circ}C$ and strain rate ranges of 0.05/sec~5/sec. The aim of this paper is to establish the quantitative equation of the volume fraction of dynamic recrystallization (DRX) as a function of processing variables, such as strain rate ($\varepsilon$), temperature (T), and strain ('$\varepsilon$). During hot deformation, the evolution of microstructure could be analyzed from work hardening rate ($\theta$). For the exact prediction of dynamic softening mechanism the critical strain ($\varepsilon_c$), the strain for maximum softening rate ($\varepsilon^*$ and Avrami' exponent (m') were quantitatively expressed by dimensionless parameter, Z/A, respectively. The transformation-effective strain-temperature curve for DRX could be composed. It was found that the calculated results were agreed with the experimental data for the steel at any deformation conditions.

• 항공우주시스템공학회지
• /
• 제15권6호
• /
• pp.59-65
• /
• 2021

In this paper, the transmission characteristics of the multi-layered composite material with wire mesh and honeycomb core for aircraft applications have been analyzed with the proposed method. The proposed method converts the conductive wire mesh into effective layer, while for the dielectric honeycomb core, effective permittivity has been derived based on volume fraction with the proposed method. The proposed method has been verified through comparison with full-wave simulation and revealed excellent. In addition, the calculation time of the proposed method is a few order of magnitude faster in comparison with the full-wave simulation.

• 센서학회지
• /
• 제28권4호
• /
• pp.231-235
• /
• 2019

We investigated the facile and effective strategy for sensitive and selective $C_2H_5OH$ sensors based on the In-decorated NiO nanoigloos. The In-decorated NiO nanoigloos is fabricated by RF sputtering using 750 nm-diameter polystyrene beads using a soft-template. The morphological evolution based on the Van der Drift model was generated through a heterojunction between In metal and NiO, resulting in a pyramidal rough surface. Upon decorating the In on the NiO surface, high sensitivity and selectivity to $C_2H_5OH$ were observed, and gas sensing mechanism was demonstrated by a high surface-to-volume and double Schottky barrier. We are confident that the method presented in this study will have a significant impact on the fabrication of effective nanostructures and their application for the gas sensors.

• Geomechanics and Engineering
• /
• 제25권4호
• /
• pp.341-345
• /
• 2021

1D sand compression response to ko-loading experiences volume contraction from low to high effective stress regimes. Previous study suggested compressibility model with physically correct asymptotic void ratios at low and high stress levels and examined only for both remolded clays and natural clays. This study extends the validity of Enhanced Terzaghi model for different sand types complied from 1D compression data. The model involved with four parameters can adequately fit 1D sand compression data for a wide stress range. The low stress obtained from fitting parameters helps to identify the initial fabric conditions. In addition, strong correlation between compressibility and the void ratio at low stress facilitates determination of self-consistent fitting parameters. The computed tangent constrained modulus can capture monotonic stiffening effect induced by an increase in effective stress. The magnitude of tangent stiffness during large strain test should not be associated with small strain stiffness values. The use of a single continuous function to capture 1D stress-strain sand response to ko-loading can improve numerical efficiency and systematically quantify the yield stress instead of ad hoc methods.

• 한국환경과학회지
• /
• 제30권8호
• /
• pp.613-619
• /
• 2021

Soil water enters the atmosphere via evapotranspiration, where it transforms into atmospheric water vapor and plays important role in the surface-atmosphere energy exchange. Soil conditions have a direct influence on the effective rainfall, and initial soil moisture conditions are important for quantitatively evaluating the effective rainfall in a watershed. To examine the sensitivity of the initial saturation to hydrologic outflow, a two-dimensional distributed FLO-2D hydrologic model was applied to a small watershed. The initial saturation was set to 0.3, 0.5, and 0.7 and the obtained results were compared. The Green-ampt model was chosen to calculate the penetration loss. Depending on the initial soil moisture, the peak flow rate varied by up to 60%, and the total water volume in the watershed by approximately 40%.

• Steel and Composite Structures
• /
• 제44권5호
• /
• pp.685-690
• /
• 2022

In this paper, the equivalent material properties of cellular metamaterials with different types of perforations have been presented using finite element (FE) simulation of tensile test in Abaqus commercial software. To this end, a Representative Volume Element (RVE) has been considered for each type of cellular metamaterial with regular array of circular, square, oval and rectangular perforations. Furthermore, both straight and perpendicular patterns of oval and rectangular perforations have been studied. By applying Periodic Boundary conditions (PBC) on the RVE, the actual behavior of cellular material under uniaxial tension has been simulated. Finally, the effective Young's modulus, Poisson's ratio and mass density of various metamaterials have been presented as functions of relative density of the RVE

• 대한방사선기술학회지:방사선기술과학
• /
• 제36권1호
• /
• pp.39-47
• /
• 2013

본 연구의 목적은 방사선 조사 용적 내 포함되는 소장의 용적 감소를 위해 복부판(Belly board, 벨리보드)과 소장변위도구(Small Bowel Displacement Device, SBDD)를 사용한 직장암 환자에서 방사선 치료 영역 내 포함되는 소장의 용적과 비만도 와의 상관성을 보고, 비만지표의 적용을 통해 SBDD의 사용지표를 삼고자 한다. 실험은 2012년 1월부터 4월까지 수술 전 혹은 수술 후 벨리보드와 SBDD를 사용해 골반부위에 방사선치료를 받은 29명의 직장암 환자를 대상으로 분석하였다. 방사선 치료는 3문 조사로 시행하였으며 1.8 Gy의 분할선량으로 중심점에 45 Gy를 조사한 계획만을 분석하였다. 환자의 키, 몸무게, 체질량지수(body mass index, BMI), 허리 엉덩이 둘레비(waist hip ratio, WHR)를 측정하여 비만도를 조사하였다. 조사되는 선량의 90%이상 들어가는 소장의 용적(high dose volume of small bowel, $HDV_{sb}$)과 33%이상 들어가는 소장의 용적(low dose volume of small bowel, $LDV_{sb}$)을 방광의 총 용적(total volume of bladder, $TV_{bladder}$) 및 비만도에 따라 비교하여 그 상관관계를 통계학적으로 분석하였다. 분석결과 수술여부 및 성별 WHR은 $HDV_{sb}$, $LDV_{sb}$에 크게 미치는 영향이 없었고 $HDV_{sb}$, $LDV_{sb}$와 BMI(p=0.031/0.083), $TV_{bladder}$ (p<0.05)는 통계적으로 유의하였다. BMI가 $HDV_{sb}$와는 유의 하지만 $LDV_{sb}$와는 크게 유의하지 않았다. (p=0.031, p>0.05) BMI는 $HDV_{sb}$와 음의 상관관계(${\beta}$=-0.402)가 있었으며 $TV_{bladder}$는 $HDV_{sb}$, $LDV_{sb}$와 음의 상관관계(${\beta}$=-0.497/-0.522)가 있었다. 특히 BMI 23 미만인 경우(BMI Group2)보다 그 이상인 경우 $HDV_{sb}$에 영향을 미치며 음의 상관성(${\beta}$=-0.525)이 있었다.($LDV_{sb}$, $HDV_{sb}$와 유의확률 각각 p=0.059, p=0.027) BMI가 23 이상인 집단(BMI Group1)에서는 $TV_{bladder}$와 $HDV_{sb}$, $LDV_{sb}$가 통계학적으로 유의하였고(p<0.04) 음의 상관성을 보였다. 비만지표인 BMI가 23 이상인 과체중 및 비만군의 직장암 방사선 치료 시 벨리보드와 SBDD를 동시에 사용하는 경우 조사용적 내 포함되는 소장의 용적을 감소시키는데 더 효과적이었다. 그러므로 벨리보드를 사용하는 직장암의 방사선 치료 시 BMI 23 이상인 한국인 환자에게는 소장변위도구를 동시에 사용 할 것을 권장한다.