• 전기학회논문지
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• 제60권4호
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• pp.830-837
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• 2011

A turbine control system which has been operated for years in a nuclear power plant was retrofitted with a newly developed digital control system. After completion of the retrofit, turbine valve tests were performed to ensure the integrity of each valve's control function. The sequence of each valve test is composed of a closing process and a reopening process. To minimize megawatt variation which normally occurs during the test sequence, we employed a kind of compensator algorithm in the new digital control system which also have been used in the old system. There were difficulties finding optimal parameter settings for our new compensator algorithm because the power plant didn't allow us to perform necessary tuning procedures while the turbine is on load operation. Therefore an alternative measure for the compensator tuning which is independent of the turbine actual operation had to be implemented. So, a process model for the test was required to overcome this situation. We analyzed the operation data of the test and implemented the process model by use of input and output variable relations. Also we verified the process model by use of another condition's operating data. The result shows that the output of model is similar to the actual operation data.

• 한국화재소방학회논문지
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• 제25권2호
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• pp.95-100
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• 2011

본 연구는 현장방염처리 물품에 대한 성능검사와 관련하여 불합리한 제도를 개선하고, 합리적인 방염성능검사 방법을 통하여 현장방염처리 물품에 대한 방염의 신뢰성을 확보하는데 궁극적인 목적이 있다. 이를 위해 최근 2년 동안 일선 소방관서에서 실시한 현장방염처리 물품에 대한 방염성능검사 실적을 토대로 최근에 사용되는 인테리어 마감자재 및 현장방염처리 경향에 대한 분석을 하였다. 또한 현장방염처리물품에 대한 성능검사 방법 및 절차, 방염처리업 등록제도의 문제점 등을 분석하여 현 실정에 적합한 방염성능검사 방법 및 성능검사의 신뢰성 확보를 위한 개선방안을 제시하고자 하였다.

• Quantitative Bio-Science
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• 제36권1호
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• pp.23-31
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• 2017

Datasets from DNA microarray experiments, which are in the form of large matrices of expression levels of genes, often have missing values. However, the existing statistical methods including the principle components analysis (PCA) and Hotelling's t-test are not directly applicable for the datasets having missing values due to the fact that they assume the observed dataset is complete in general. Many methods have been proposed in previous literature to impute the missing in the observed data. Troyanskaya et al. [1] study the k-nearest neighbor (kNN) imputation, Kim et al. [2] propose the local least squares (LLS) method and Rubin [3] propose the multiple imputation (MI) for missing values. To identify differentially expressed genes, we propose a new testing procedure when the missing exists in the observed data. The proposed procedure uses the Stouffer's z-scores and combines the test results of individual imputed samples, which are dependent to each other. We numerically show that the proposed test procedure based on MI performs better than the existing test procedures based on single imputation (SI) by comparing their ROC curves. We apply the proposed method to analyzing a public microarray data.

• 대한조선학회논문집
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• 제57권6호
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• pp.345-352
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• 2020

This study aims to investigate the crabbing motion of the research vessel "NARA" by full-scale maneuvering trials. The crabbing test method refers to ITTC recommended procedures and guidelines. In order to minimize the fluctuation of the heading angle due to the external force acting on the hull during the pure lateral motion, the tests are conducted using the dynamic positioning system applied to the ship. The test results are analyzed by applying a low-pass filter to remove the noise included in the measurement data. Three conditions are set to define the steady state of crabbing motion. The index to be derived from the crabbing test is quantitatively presented. The ship is confirmed to be capable of the lateral motion of up to 0.844m/s in Beaufort 3.

• 한국신뢰성학회:학술대회논문집
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• 한국신뢰성학회 2001년도 정기학술대회
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• pp.105-111
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• 2001

In this study, for improvement of pneumatic valve reliability, we grasped the falling-off problem in efficiency of domestic valve and performed detailed analysis the relating International standards, and we also decided sampling method and reliability evaluation items to be evaluated valves. And, in addition, we describe the developed evaluation standard to increase the competition power and to improve the reliability of domestic pneumatic valve manufacturers through deciding of test conditions and thesis of evaluation procedures to each evaluation items.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 1994년도 봄 학술발표회 논문집
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• pp.187-190
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• 1994

During the initial design phases for prestressed concrete structures, the mecessary information concerning the physical properties of the hardened concrete such as creep, drying shrinkage, modulus of elasticity, and Poisson's ratio are obtained from design assumptions or accepted standards. But these assumptions may not totally reflect the actual long-term behavior of the concrete. So they may be of limited use in predicting the actual behavior. The purpose of this paper is to describe the test procedures and methods of evaluation which were used during the long-term study.

• 한국수학교육학회지시리즈A:수학교육
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• 제38권2호
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• pp.165-172
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• 1999

$\sub$e/$\^$2/, that were results from those three sources of such imperfection. Especially to eliminate the differences in severity among many raters the randomization procedure of raters sample was very effective in enhancing the reliability of ratings with comparatively small groups of examinees and raters. And we also introduced the new rating methods, i.e. the 2-step diagnostic procedures to check the sizes of the reliability stability of raters and the sore adjustment method to enumerate the optimal mean values in rating the examinees.

• 품질경영학회지
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• 제17권2호
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• pp.93-100
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• 1989

Nonlinear rank statistics for the simple tree alternatives problem are considered. Pitman efficiencies between several procedures are studied. A new maximin procedure is suggested and shown to have good efficiency properties. Additionally, it is desirable to terminate the experiment early comparing well known rank statistics or multiple comparison test statistics.

• 응용통계연구
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• 제8권2호
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• pp.187-200
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• 1995

본 논문에서는 회귀모형에서의 오차항이 비선형시계열(nonlinear time series)을 따르는 경우에 오차항이 선형인지를 검정하는 방법에 대해서 연구하고 있다. 이를 위해서 회귀계수의 대표본 성질을 규명하고 잔차를 이용한 오차항의 선형성 검정통계량을 유도하고 그 성질을 연구해 보았다.

• 품질경영학회지
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• 제27권4호
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• pp.256-265
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• 1999

In this paper, we Present the implementation of statistical process control software by using XLISP-STAT which is a kind of object oriented language under Windows environment. This software can be used to generate the graphic objects for various control charts, histogram and plots using the full-down menu system. This software can also be used to calculate control limits, process capability indices and test procedures for normality.