• Communications for Statistical Applications and Methods
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• 제8권1호
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• pp.209-217
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• 2001

We obtain the approximate maximum likelihood estimators (AMLEs) for the scale and location parameters $\theta$ and $\mu$ in the three-parameter Weibull distribution based on Type-II censored samples. We also compare the AMLEs with the modified maximum likelihood estimators (MMLEs) in the sense of the mean squared error (MSE) based on complete sample.

• Journal of the Korean Data and Information Science Society
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• 제1권
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• pp.47-57
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• 1990

A method which determines the number of replications in the simulation is proposed, particularly for small-sample comparison of estimators. This method takes the smallest number of replications that makes the difference of mean square errors be statistically significant and provides an efficient algorithm for calculating the standard error of the mean square error. Two examples are illustrated, the first one is on comparison of mean and median ; the second, the Kaplan-Meier type and Buckley-James type estimators of a quantile function with censored data.

• 품질경영학회지
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• 제24권2호
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• pp.54-64
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• 1996

The inspection policy and inspection error are very critical factors which influence the outgoing quality. In other words, such factors influence the acceptance rate of the incoming matarials. Hence, the outgoing lot size is varied. This paper presents a method to compute the break-even point(pb1, pb2) under these two factors, which canbe used to determine the economic acceptance inspection type.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2005년도 ICCAS
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• pp.2468-2473
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• 2005

Because the rain gauges of tipping bucket type can easily use the digital signal, the rain gauges are widely used for the meteorological observation. In general, the resolution of rain gauges of tipping bucket type can be categorized by the 0.1mm, 0.5mm, and 1.0mm classes. But, the error of the tipping bucket rain gauges is made by the intensity of rainfalls and is expected to make the standard calibration method for error measurement. Thus, we developed the hardware of standard calibration facility for rain gauges by weighting measurement method and proposed the standard procedure by rainfall intensity in this study Also, we calculated the error for the rainfall intensity and obtained useful result through the proposed calibration method.

• Communications for Statistical Applications and Methods
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• 제27권1호
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• pp.47-64
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• 2020

In this paper, we derive some estimators of the scale parameter of the exponentiated half-logistic distribution based on the multiply Type-I hybrid censoring scheme. We assume that the shape parameter λ is known. We obtain the maximum likelihood estimator of the scale parameter σ. The scale parameter is estimated by approximating the given likelihood function using two different Taylor series expansions since the likelihood equation is not explicitly solved. We also obtain Bayes estimators using prior distribution. To obtain the Bayes estimators, we use the squared error loss function and general entropy loss function (shape parameter q = -0.5, 1.0). We also derive interval estimation such as the asymptotic confidence interval, the credible interval, and the highest posterior density interval. Finally, we compare the proposed estimators in the sense of the mean squared error through Monte Carlo simulation. The average length of 95% intervals and the corresponding coverage probability are also obtained.

• 한국항해항만학회지
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• 제42권3호
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• pp.159-166
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• 2018

해양사고를 야기한 선원들의 행동오류 식별은 해양사고 예방, 저감 또는 억제에 중요한 단서가 된다. 본 연구의 목적은 SRKBB(Skill-, Rule-, and Knowledge Based Behavior) 이론을 이용하여 해양사고 종류별로 선원들의 행동오류를 식별하는데 있다. 행동오류 식별을 위하여 9년간(2008~2016)의 해양사고 재결서 1,744건에 기록된 사고내용을 수집한 후, 사고를 야기한 선원들의 행동오류를 SBBE(Skill-Based Behavioral Error), RBBE(Rule-Based Behavioral Error), KBBE(Knowledge-Based Behavioral Error) 세 가지 종류로 분류하였다. 행동오류 분류를 위하여 SRKBB 이론을 적용한 행동오류 분류용 프레임워크를 제안하고, 이 프레임워크를 이용하여 행동오류 데이터를 구축하였다. 사고종류별 행동오류의 빈도를 분석한 결과, 충돌사고는 SBBE가 가장 높은 빈도로 관측되었고, 이어서 RBBE가 두 번째로 높은 빈도로 관측되었다. 이에 반하여 좌초, 전복 및 침몰 등의 사고는 KBBE 중에서 높은 빈도로 관측되었다. 연구결과, 해양사고 종류별로 선원들의 행동오류 식별이 가능하였고, 해양사고 종류별 사고 예방에 필요한 선원들의 행동오류 보정에 관한 단서를 확보할 수 있었다.

• 전기학회논문지
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• 제58권8호
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• pp.1624-1632
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• 2009

In this study, we introduce the design methodology of an optimized Interval Type-2 fuzzy controller. The fixed MF design of type-1 based FLC leads to the difficulty of rule-based control design for representing the linguistically uncertain expression. In the Type-2 FLC as the expanded type of Type-1 FLC, we can effectively improve the control characteristic by using the footprint of uncertainty(FOU) of membership function. Type-2 FLC has a robust characteristic in the unknown system with unspecific noise when compared with Type-1 FLC. Through computer simulation as well as practical experiment, we compare their performance by applying both the optimized Type-1 and Type-2 fuzzy cascade controllers to ball and beam system. To evaluate each controller performance, we consider controller characteristic parameters such as maximum overshoot, delay time, rise time, settling time and steady-state error.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2006년도 추계학술대회 논문집
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• pp.1529-1535
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• 2006

Human error is one of the major contributors to the railway accidents or incidents. In order to develop an effective countermeasure to remove or reduce human errors, a systematic analysis should be preferentially performed to identify their causes, characteristics, and types of human error induced in accidents or incidents. This paper introduces a case study for human error analysis of the railway accidents and incidents. For the case study, more than 1,000 domestic railway accidents or incidents that happened during the year of 2004 have been investigated and a detailed error analysis was performed on the selected 90 cases, which were obviously caused by human error. This paper presents a classification structure for human error analysis, and summarizes the analysis results such as causes of the events, error modes and types, related worker, and task type.

• 한국융합학회논문지
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• 제8권12호
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• pp.23-29
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• 2017

본 논문은 1mm 이하의 극소형 패키지 개발을 위한 금형 기술을 소개한다. 또한 이 금형 기술을 사용하여 산출된 결과들의 오류 패턴을 분석한다. 기존의 극소형 금형 구조는 일체형이었는데 EDM의 표면이 거칠어 오류율을 증가시키는 원인이 되었다. 이 원인으로 인해 금형의 크기를 더 줄이는데 방해요소로 작용하였다. 이에 반해 제안하는 금형기술은 기존의 일체형 방식에서 벋어나 조립식 방법을 사용하여 일체식의 한계를 극복하고자 한다. 또한 새로 제안된 금형 구조를 이용해 산출한 결과에 결함 패턴을 분류하고, 각 패턴의 발생 확률을 분석하여 검출기를 개발하려는 기초 자료로 사용하려 한다.

• 대한수학회보
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• 제48권1호
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• pp.95-104
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• 2011

We improve some inequalities of Ostrowski-like type and further generalize them.