• 한국철도학회논문집
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• 제9권6호
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• pp.772-777
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• 2006

Three-dimensional numerical study is performed for the flow analysis around the rolling stock with square cross section (Mugungwha train model). The height (H) of rolling stock is considered as the characteristic length and the total length of rolling stock is 40 which correspond to 1/2 unit of rolling stock. The gap between the surface and rolling stock is 0.17H which is average value. The relative velocity between the surface and rolling stock is assumed to be zero and Re=10,000 based on the characteristic length. Low Re ${\kappa}-{\epsilon}$[15] is employed for the calculation of turbulence which resolve all the way to the solid surface (laminar sub-layer). Large flow separation occurred at the front head of train and a pair of vortex is generated on both top and side of rolling stock. The behavior of vortices on the top of the rolling stock is believed to affect the performance of the pantograph which should be intensively investigated. The difference between the high pressure in the front stagnation region of train and the low pressure in the rear separated region causes a large pressure drag. A large pair or vortex are generated in the rear of train and the size of vortex is increased more than the size of cross section of train.

• 산업경영시스템학회지
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• 제33권3호
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• pp.79-86
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• 2010

Causing by economic stagnation and financial management difficulty of the domestic small and medium business company, the actual condition which enlarges the plan of politic funds increased from the government. The government authority as the SBC (small and medium business promotion corporation) evaluates the domestic small and medium business company, and directly executes a governmental politic funds. Financial analysis is a important factor of enterprise evaluation among various valuation bases. However because of applying to the whole domestic manufacturing industry on financial evaluation, Current financial evaluation index effectively cannot reflect the feature of a regional industry. A whole manufacturing industry index considers a standard for the comparison evaluation of domestic manufacturing industry and compares with the other industries and the world-wide nation industry change, But, there is a difference from indexes of corresponding industry in specific regions. This paper proposes a model of evaluation index for the efficient execution of politic funds. We considers three manufacturing industries for proposed model which are shipbuilding, machine tool and airline industries in Gyeongsangnam-do region.

• 대한한방부인과학회지
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• 제28권2호
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• pp.174-182
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• 2015

Objectives : AMH (Anti-Müllerian Hormone) is considered a sensitive marker of ovarian reserve, and it tends to be included among basic fertility tests. This paper is to report four pregnancies which were achieved by subfertile women with low AMH level after Korean medical treatments. Methods : Four cases of pregnancy by subfertile women, aged 34 to 37, with low AMH level (0.04 to 0.76 ng/mL), after Korean medical treatments between July 2012 and May 2015, were analysed. The patients were diagnosed as Kidney deficiency (腎虛), Blood extravasation (瘀血) and/or Liver Qi stagnation (肝氣 鬱結). Herbal medicine, acupuncture, pharmacopuncture and moxibustion treatments were applied. Results : The four subfertile women with low AMH level achieved pregnancy after Korean medical treatments. Conclusions : The case report suggests that Korean medical treatment can be an effective option for subfertile women with low AMH level before Assisted Reproductive Technology.

• 한국재난정보학회 논문집
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• 제5권2호
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• pp.88-106
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• 2009

The potential risks of Korean public security has been increasing by economic stagnation. As a result of this, a feeling of unrest about our society causes expansion of private security industry as well as necessity of professional education. It has been 15years to produce security expert in colleges which is professional education institute, and academic efforts and contributions to society are shown remarkable results for the period. A private security industry had got public interest as a potential favorable job, because of increasing dependence of public to take care of unrest facts. Many colleges have introduced courses about public security because of facing necessity of professional education system. Then total 59 institutes including 22 universities and 37 colleges introduce courses of public security. Although name of courses are diverse depends on institution, purpose of course or members of course, the ultimate purpose of these courses is preventing public from crimes and managing public security. A fixed and out of date education system of universities in Korea can not produce talent person who people, companies and government want. The institutions have been recruiting many student so far, and it shows growth of the industry in quantity aspects. However quality aspect of the industry has been failed because it is hard to get a job for graduated students. Consequently, to improve quality of the industry people need cooperation of institution, professors and students.

• 동력기계공학회지
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• 제12권5호
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• pp.48-53
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• 2008

Heat exchangers are commonly used in practice in a wide range of application, from heating and air-conditioning system in a household, to chemical processing and power production in a large plant. Heat transfer in a heat exchanger usually involves convection in each fluid and conduction through the wall separating the two fluids. The heat transfer characteristics of tube banks of in-line arrangements of four circular cylinders in a cross flow are compared for a range of tube locations and Reynolds numbers. The in-line pitch ratio was set up in the range of $1.5\leq L/d\leq4.0$, where L is the center to center distance and d the circular cylinder diameter, and in the Reynolds number of $13,000\leq Re\leq50,000$. The local and mean Nusselt numbers were estimated, and then. Subsequently, the heat transfer characteristics of four circular cylinders were found to exhibit a strong dependency upon the cylinder spacing and separation point of their upstream cylinders.

• 대한기계학회논문집
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• 제16권8호
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• pp.1583-1594
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• 1992

본 연구에서는 동층류 축대칭 확산화염에서 이전까지의 화염해석 방법들을 면 밀히 고찰하여 층류 확산화염 방식의 연소문제를 해결하는데 있어서 접근이 용이하고 타당성을 가지는 화염해석 방법을 찾아내는데 있으며 매연 입자에 관한 생성및 산화모 델을 총체적으로 연결하여 실험결과와의 비교를 통해 적절한 모델인수를 결정하며 복 사효과와 열영동효과를 고려하여 화염해석과 화염내의 매연입자의 분포를 예측하는데 있다.

• Journal of Advanced Marine Engineering and Technology
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• 제34권8호
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• pp.1094-1099
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• 2010

수중에 있는 구 주위의 3차원 층류유동을 수치 해석하였다. 유한체적법을 기반으로 나비에 스톡스 방정식을 비구조격자로 풀어 물체주위의 동역학 현상을 규명하였다. 보티시티, 속도, 동압, 레지듀얼, 항력계수 등의 데이터를 가지고 분석하였다. 레이놀드 수는 425, 300, 250, 100 이다. 구 사이의 거리가 작은 경우가 구 한 개의 후류 유동보다 안정됨을 보였고 구 사이의 간격이 커짐에 따라 유동현상은 불안정하게 나타났다. 후방의 구는 정체압력의 감소를 보였고 이로 인해 저항이 줄어들게 됨을 알 수 있었다. 항력계수의 비교는 본 수치계산이 타당함을 입증하였다.

• 대한기계학회논문집B
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• 제24권8호
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• pp.1128-1138
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• 2000

Pumping action in ejector systems is generally achieved through the mixing of a high-velocity and high-energy stream with a lower-velocity and lower-energy stream within a duct. The design and performance evaluation of the ejector systems has developed as a combination of scale-model experiments, empiricism and theoretical analyses applicable only to very simplified configurations, because of the generic complexity of the flow phenomena. In order to predict the detailed performance characteristics of such systems, the flow phenomena throughout the operating regimes of the ejector system should be fully understood. This paper presents the computational results for the two-dimensional supersonic ejector system with a second throat. The numerical simulations are based on a fully implicit finite volume scheme of the compressible Reynolds-averaged Navier-Stokes equation in a domain that extends from the stagnation chamber to the diffuser exit. For a wide range of the operating pressure ratio the flow field inside the ejector system is investigated in detail. The results show that the supersonic ejector systems have an optimal throat area for the operating pressure ratio to be minimized.

• 대한한의학회지
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• 제25권1호
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• pp.96-110
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• 2004

The GyoJungEuiSeoGuk(교정의서국, the bureau for revising of medical books) which was established in the 2nd year of InJong GaWoou of Song dynasty, made comparative analyzation about various kinds of publication and reference materials of all classical medical books that was published until Jin Han and Su Dang dynasty, revised the medical books like as Bozushinnongboncho(보주신농본초), Zungkwangbojuhwangjenegyungsomun(중황보주황제내경소문), Shanghanlon(상한론), Bigupchunggumyobang (비급천금요방), Magkyung (맥경), Hwangjechimgugapeulgyung(황제침구갑을경), Oedaebiyo (외대비요), Chunggumikbang(천금익방) etc. The signification of such revision was not only to preserve the materials which may be lost before, bibliographically and also make the books of Hwangjenegyung(황제내경), Shanghanlon(상한론) etc. become more regularly. And it made the foundation of Korean Medical research depends on the documentary records so as to make it have big development by deductive method till the beginning of modem age. The success of GyoJungEuiSeoGuk indicates that the stagnation of Korean Medical research due to $it^{circ}{\Phi}s$ behind with the development of politics-economy, social culture and scientific technology which based on western scientific culture. So we may draw the conclusion that the success of scientific research needs to parallel with the external and internal factors of the surrounding science.

• 대한기계학회논문집B
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• 제24권12호
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• pp.1670-1677
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• 2000

An experimental investigation on heat transfer characteristics of two-dimensional heated blocks using a confined impinging slot jet has been performed. The effect of jet Reynolds number(Re=3900, 5800, 9700), streamwise block spacing(p/w=0.5, 1, 1.5) and dimensionless nozzle to block distance(H/B=1, 2, 4, 6) have been examined with five isothermally heated blocks. With the measurement of jet mean velocity and turbulence intensity distributions at nozzle exit, initially turbulent regimes, are classified. To clarify local heat transfer characteristics, naphthalene sublimation technique as used. The maximum Nusselt number at the stagnation point for the jet Reynolds number is occurred at H/B=4. Besides, the local and a average heat transfer of heated blocks increase with decreasing streamwise block spacing and increasing jet Reynolds number.