• 한국식품조리과학회지
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• 제10권4호
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• pp.351-356
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• 1994

Comparisions were made for cooking times, internal temperatures, thiamin contents and textural properties of various portion weights of egg mixture cooked in a microwave oven at high and/or low power levels and in a conventional double boiler. The mean internal temperatures of conventionally cooked egg mixtures were 76.4~80.7$^{\circ}C$. When cooking was made by steaming, the mean internal temperature were comparable among samples. With the microwave cooking, the range of mean temperature was 83.8~96.4$^{\circ}C$, and they were significantly higher than the conventionally cooked egg mixtures. The hardness determination was conducted using universal testing machine and a taste panel. Samples cooked with steam or with larger portion weight had softer texture than samples cooked by microwaves or smaller amount, respectively. Mean internal temperature was significantly(r=0.99, p<0.05) correlated with mechanical hardness determination. Statistical analyses indicated no significant difference in the thiamin content among various treatments.

• Communications for Statistical Applications and Methods
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• 제13권3호
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• pp.607-619
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• 2006

We consider the problem of testing the existence of change in mean and estimating the change-point when the data are from the normal distribution. A change-point estimator using the likelihood ratio test statistic, Gombay and Horvath (1990) test statistic, and nonparametric change-point estimator using Carlstein (1988) empirical distribution are studied when there exists one change-point in the mean. A power study is done to compare the change test statistics. And a comparison study of change-point estimators for estimation capability is done via simulations with S-plus software.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2004년도 하계학술대회 논문집 A
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• pp.464-466
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• 2004

This paper proposes a method to consider an aging failure probability and survival probability of power system components unlike uses only aging failure probability in existing mean life calculation. The estimates of the mean and its standard deviation is calculated by using Weibull distribution and each estimated parameters is obtained from Data Analytic Method (Type II Censoring). The parameter estimation using Data Analytic Method is simpler and faster than a traditional calculation method. This paper shows how to calculate the mean life and its standard deviation by the proposed method and illustrates a exactness using real historical records of generator utilities in korea.

• Journal of the Korean Statistical Society
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• 제26권2호
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• pp.199-210
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• 1997

Using regression methods based on quasi-likelihood equation, one only needs to specify the conditional mean and variance functions for the response variable in the analysis. In this paper, an omnibus lack-of-fit test is proposed to test the validity of these two functions. Our test is consistent against the alternative under which either the mean or the variance is not the one specified in the null hypothesis. The large-sample null distribution of our test statistics can be approximated through simulations. Extensive numerical studies are performed to demonstrate that the new test preserves the prescribed type I error probability. Power comparisons are conducted to show the advantage of the new proposal.

• 한국태양에너지학회 논문집
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• 제38권1호
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• pp.13-24
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• 2018

As part of the "Carbon free Island 2030" policy, the local government of Jeju Island is currently working to reduce carbon through renewable energy supply. However, renewable energy is difficult to predict due to intermittent characteristics. If the share of renewable energy increase, it is difficult to plan of supply of electricity to grid due to that characteristic of renewable. In this paper analyze the fluctuation rate and the capacity credit of wind power and PV to find out how much wind power and PV contribute to supply of electricity of power system in Jeju. As a result mean value of variation rate of wind power and PV is about 3%, 5% and capacity credit is about 10% and 2% respectively.

• 한국소음진동공학회논문집
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• 제11권9호
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• pp.398-405
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• 2001

The maximum and mean indicated pressure of two stroke low speed diesel engine has been continuously increased with a view of increasing engine power and also reducing fuel consumption. As a result, axial excitation has been increased comparing to that of the previous one. So the axial vibration damper in standard one is applied to all two stroke low speed diesel engine at the free end of crankshaft. Though many studies were carried out for marine use, few has been made for diesel power plant because there was little demand for power plant. Nowadays, diesel engine is much to be used for many benefits. In this paper, the optimum design of axial vibration on the 65 kW diesel power plant with tow 9K80MC-S engines of 9 cylinders was carried out. And the axial-torsional coupled vibration of this shafting system is identified by theoretical analysis and vibration measurement.

• 대한전자공학회논문지
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• 제6권1호
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• pp.1-11
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• 1969

TRIGA MARK-II 원자로의 각출력에 대한 주파수스펙트럼을 측정하므로서 원자로의 전달함수의 계수율을 선정하였다. 랜덤한 파일잡음의 검출은 전전력에서 10-7A인 평행원부형 전리함을 이용하였다. 주파수스펙트럼은 동조형대역통과 여파기를 가지고 해석하여 원자로의 동특성과 그 피라미터를 구하고 전력측정을 하였다.

• Journal of Power Electronics
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• 제10권6호
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• pp.660-666
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• 2010

This paper presents the approach followed to develop a course that introduces reliability into the design of power electronics converters. The course is part of the curriculum of a master of science in electrical engineering program, and it is aimed at providing reliability tools that can be used in a straightforward manner, while avoiding the mathematical intricacies. The reliability calculations are performed according to the Military Handbook 217, using the evaluation version of a commercial software package which greatly reduces the computational burden usually associated with this task. The course assessment shows that, after attending the course, students were able to improve the mean time between failures in a power-electronics converter, from a minimum of 5%, up to 100%.

• 전기학회논문지
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• 제57권4호
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• pp.560-566
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• 2008

Today, as the power trades between generation companies and power customer are liberalized, the uncertainty level of operated power system is rapidly increased. Therefore, transmission operators as decision makers for transmission expansion are required to establish a deliberate investment plan for effective operations of transmission facilities considering forecasted conditions of power system. This paper proposes the methodology for the optimal solution of transmission expansion in deregulated power system. The paper obtains the expected value of transmission congestion cost for various scenarios by using occurrence probability. In addition, the paper assumes that increasing rates of loads are the probability distribution and indicates the location of expanded transmission line, the time for transmission expansion with the minimum cost for the future by performing the Montecarlo simulation. To minimize the investment risk as the variance of the congestion cost, Mean-Variance Markowitz portfolio theory is applied to the optimization model by the penalty factor of the variance. By the case study, the optimal solution for transmission expansion plan considering the feature of market participants is obtained.

• 통합자연과학논문집
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• 제11권4호
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• pp.204-208
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• 2018

Comparison of different optimizer performance in photovoltaic power modeling using artificial neural deep learning techniques is described in this paper. Six different deep learning optimizers are tested for Long-Short-Term Memory networks in this study. The optimizers are namely Adam, Stochastic Gradient Descent, Root Mean Square Propagation, Adaptive Gradient, and some variants such as Adamax and Nadam. For comparing the optimization techniques, high and low fluctuated photovoltaic power output are examined and the power output is real data obtained from the site at Mokpo university. Using Python Keras version, we have developed the prediction program for the performance evaluation of the optimizations. The prediction error results of each optimizer in both high and low power cases shows that the Adam has better performance compared to the other optimizers.