• 대한기계학회:학술대회논문집
• /
• 대한기계학회 2004년도 추계학술대회
• /
• pp.1721-1726
• /
• 2004

Heat rate is a representative index to estimate the performance of turbine cycle in nuclear power plant. Accuracy of heat rate calculation is dependent on the accuracy of measurement for plant status variables. Uncertainty of heat rate can be modeled using uncertainty propagation model. We developed practical estimation model of heat rate uncertainty using the propagation and regression model. The uncertainty model is used in the performance analysis system developed for the operating nuclear power plant.

• 품질경영학회지
• /
• 제31권3호
• /
• pp.193-204
• /
• 2003

In this paper, we consider a periodic preventive maintenance(PM) policy in which each PM reduces the hazard rate but remains the pattern of hazard rate unchanged. And the system undergoes only minimal repairs at failures between PM's. The expected cost rate per unit time is obtained. The optimal number N of PM and the optimal period x, which minimize the expected cost rate per unit time are discussed. Explicit solutions for the optimal periodic PM are given for the Weibull distribution case.

• 제어로봇시스템학회:학술대회논문집
• /
• 제어로봇시스템학회 1994년도 Proceedings of the Korea Automatic Control Conference, 9th (KACC) ; Taejeon, Korea; 17-20 Oct. 1994
• /
• pp.106-111
• /
• 1994

We proposed a new variable sampling rate model which expresses the phenomena with both rapid and slow components. A method for determining the variable sampling rate and the older of the time series model was explained. The proposed variable sampling rate model was evaluated based oil an information criterion(AIC). Tile variable sampling rate model brought smaller an information criterion than one of a constant sampling rate model of conventional type, and was proved to be effective as a prediction model of the system with both rapid and slow components.

• 대한치과의사협회지
• /
• 제22권12호통권187호
• /
• pp.1059-1066
• /
• 1984

As an appraisal of Water Fluoridation Program in Chungju, fluoride content in the water of that city was examined, and 1176 K primary school children aged from 6 to 13 were surveyed on their oral hygiene status. The results were as followings: 1. Fluoride content ............ 0.8 ppm 2. dmf rate ............ 59.27% DMF rate ............ 39.46% 3. dmf t rate/index ............ 27.75%/2.40 dmf s rate/index ............ 11.91%/5.14 4. DMF T rate/index ............ 6.12%/0.93 DMF S rate/index ............ 1.65%/1.26

• 충청수학회지
• /
• 제30권3호
• /
• pp.337-340
• /
• 2017

In this article, we present characterizations of the power distribution via the identical hazard rate of lower record values that $X_n$ has the power distribution if and only if for some fixed n, $n{\geq}1$, the hazard rate $h_W$ of $W=X_{L(n+1)}/X_{L(n)}$ is the same as the hazard rate h of $X_n$ or the hazard rate $h_V$ of $V=X_{L(n+2)}/X_{L(n+1)}$.

• 한국철도학회:학술대회논문집
• /
• 한국철도학회 2001년도 추계학술대회 논문집
• /
• pp.83-90
• /
• 2001

Generally, fare system is divided diminishing fare rate to distance into proportional fare rate to distance. In this paper, it is simulated the financial effect on the HSR operator introduced the diminishing fare rate to distance system. The diminishing fare rate to distance system increase the railroad demand, so profit of HSR operator is increased. We find that the diminishing fare rate to distance system is better than proportional fare rate to distance system.

• 기술혁신학회지
• /
• 제5권1호
• /
• pp.59-71
• /
• 2002

Risk, or exposure to uncertainty, is an inherent of risk-adjusted discount rate. It is therefore important part factor in the determination of risk-adjusted discount rate. This paper suggests the method to quantify risk and explains the process how to transfer quantified risk into incremental discount rate. The estimates of underlying risks will help determine the size of appropriate risk-adjusted discount rate with logical and scientific way when the technology valuation is made.

• 한국마이크로전자및패키징학회:학술대회논문집
• /
• 한국마이크로전자및패키징학회 2001년도 추계 기술심포지움
• /
• pp.230-234
• /
• 2001

본 연구에서는 Alumina(A1$_2$O$_3$) based Slurry를 이용하여 CU CMP를 할 때 첨가제의 영향을 Removal rate와 Etch rate 측면에서 조사하였다. 각각의 첨가제의 종류와 조성의 변화에 따라 Polishing에 미치는 영향을 연구하였다. Cu의 Removal rate는 Etch rate와 달리 Organic acid의 종류에 직접적으로 영향을 받는다. Citric acid는 높은 Removal rate와 슬러리 내에서 안정성이 가장 좋은 결과를 보이고 있다. Citric acid의 농도가 증가하면 증가할수록 Removal rate는 증가하였다. BTA의 농도에 따라서 Cu의 Removal rate와 Etch rate의 감소를 확인할 수 있다. EDTA의 농도에 따라서는 증가함을 볼 수 있다.

• KDI Journal of Economic Policy
• /
• 제39권2호
• /
• pp.75-98
• /
• 2017

This paper aims to estimate the social discount rate (SDR) rather than dig into its theoretical foundation. As SDRs can be derived by investigating both the rate of return on investment and the social time preference rate, we estimate the marginal productivity of both private and public capital and the time preference rate based on the Euler equation. In order to provide a single representative SDR, the weighted averages of the marginal productivity and time preference rate, whose weights are determined by the flow of funds data reflecting the social demand of funds, are presented. Based on the empirical results, we argue that the marginal productivity of private capital stands in the middle of the 3% range while that of public capital varies from 4.5% to 8.6%, with the time preference rate showing a decreasing trend from 3.2% in the early 2000s to 1.2% by around 2030. The single representative SDR or the weighted SDR is estimated to be approximately 3.0~4.5% and expected to continue its downward trend for the foreseeable future.

• 한국환경보건학회지
• /
• 제32권3호
• /
• pp.222-226
• /
• 2006

Smoking of tobacco cigarettes is associated with a rise in blood pressure together with increase in heart rate. This study was aimed to examine the acute effect of tobacco and non-tobacco cigarette smoking on the blood pressure and heart rate by randomized crossover study. In the results, systolic/diastolic blood pressure and heart rate changes after smoking were significantly different between male and female group. Blood pressure and heart rate were elevated after smoking, but statistical significance for the difference was identified only in the female group. Because Non-tobacco smoke made from leaves of E. ulmoides has no nicotine, its effect on blood pressure and heart rate was negligible. Remarkable difference of heart rate changes in women was observed between tobacco cigarette smoking group and non-tobacco cigarette smoking group.