http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
배관용 틸팅디스크 체크밸브의 손실저항 절감에 관한 연구
김정환(J. H. Kim),박재현(J. H. Park),이현식(H. S. Lee),남시환(S. H. Nam),황성홍(S. H. Hwang) 한국마린엔지니어링학회 2006 한국마린엔지니어링학회 학술대회 논문집 Vol.2006 No.-
In generally, under the influence of over-pressure drop, serious problems such as cavitation, choked flow, flashing and vibration has been coming around the tilting disk check valve. A PIV experiment to examine the cause of energy loss has been performed and the improvement configuration of valve seat based on this visualization results is proposed. In the visualization results, flows in the piping system became instability under the influence of the shape of boss. This unstable flows induces sudden pressure drop in the piping system. So, we change the configuration of boss as a streamlined design to be stabilized the flows. A pressure measurement has been performed to know that the influence of the configuration change. In result, the rate of pressure loss reduction is about 22% at the position of No. 2 and 24.2% at the position of No. 6 in comparison with pre-improved shape.
진강규(G. G. Jin),이윤형(Y. H. Lee),이현식(H. S. Lee),진상훈(S. H. Jin),이승환(S. H. Lee),소명옥(S. M. So),황승욱(S. W. Hwang) 한국마린엔지니어링학회 2007 한국마린엔지니어링학회 학술대회 논문집 Vol.2007 No.-
Controlling engine coolant temperature is one of the tasks performed by today's cooling systems. In this paper, we present the PID control of vehicle cooling systems with a hydraulic coupling to overcome the inherent problem with direct-drive fans. The PID controller is tuned by a real-coded genetic algorithm(RCGA) and anti-windup is incorporated with the PID controller. Simulation is carried out to show the performance.
김정환(J. H. Kim),이현식(H. S. Lee),김정렬(J. H. Kim),김진구(J. G. Kim) 한국마린엔지니어링학회 2006 한국마린엔지니어링학회 학술대회 논문집 Vol.2006 No.-
A numerical investigation was performed to determine the effect of airfoil on the optimum flap height and tip clearance using NACA0015 Wells turbine. A Navier-Stokes code, CFX-10 were used to calculate the flow field of the Wells turbine. The basic feature of the Wells turbine is that even though the cyclic airflow produces oscillating axial forces on the airfoil blades, the tangential force on the rotor is always in the same direction. Geometry used in defining the 3-D numerical grid is based upon that of an experimental test rig. This paper tries to analyze the solidities and flow rate of Wells turbine with the numerical analysis.
김병만(B.M.Kim),강원룡(W.L.Kang),박승수(S.S.Park),이현식(H.S.Lee),진강규(G.G.Jin) 한국해양대학교 해사산업연구소 1999 海事産業硏究所論文集 Vol.9 No.-
This paper presents a scheme for designing a fuzzy model-based controller for two-tank systems. The fuzzy model is characterized by fuzzy "if-then" rules which represent local input-output relationships at several operating points whose consequence parts are called linear subsystems of a nonlinear system The parameters of the fuzzy model are adjusted by a genetic algorithm. Then an optimal state feedback controller is obtained based on the fuzzy model. A simulation on a two-tank system illustrates the performance of the proposed controller.
정상임부와 임신중독환자의 혈장 Renin 활성도 및 Aldosterone 농도에 미치는 이뇨의 효과
김한석,이현식,이장규,성호경,고주환,조석신 대한핵의학회 1973 핵의학 분자영상 Vol.7 No.1
The changes of plasma renin activity, aldosterone concentration, serum sodium, and potassium levels were studied before and after the water loading followed by diuretics injection. The materials were: 13 non-, 11 normal-, and 11 toxemic pregnancy cases. The plasma renin activity and aldosterone concentration of the cord and postpartum blood were also measured. Following were the results: 1. The plasma renin activity was elevated significantly in normal pregnancy, and slightly in toxemic pregaancy. The serum sodium levels were decreased in pregnancy. 2. The plasma aldosterone concentration was slightly decreased in normal pregnancy, and slightly increased in toxemic pregnancy, however, statistically insignificant. 3. The plasma renin activity of the cord and postpartum blood were lower than those of pregnancy cases. 4. The changes of plasma renin activity after the diuretic administration showed an initial increase, which recovered within 2 hours. These changes were the least in normal pregnancy, and the most in toxemic pregnancy. 5. The changes of plasma aldosterone concentration after the diuretic administration were similar to those of plasma renin activity, although the variations were not so wide.