• 대한전기학회:학술대회논문집
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• 대한전기학회 2002년도 합동 추계학술대회 논문집 정보 및 제어부문
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• pp.54-57
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• 2002

In this paper model reference adaptive control (MRAC) of linear time-varying(LTV) systems is considered. MRAC for a linear time invariant(LTI) system does not assure the boundedness of the output and parameter estimation errors in the presence of time variations of the parameters. However, changing the adaptive laws such as use of $\sigma$-modification can result in the boundedness of the output and parameter estimation errors[5]. Together with the $\sigma$-modification in the adaptive law, we also modify the control law by adding an additional term to the standard control law. The additional term leads to smaller bounds of the output and parameter estimation errors when compared to the case where only the standard control law is applied.

• 대한원격탐사학회지
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• 제24권5호
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• pp.483-496
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• 2008

Qualified ground control points (GCPs) are required to construct a digital elevation model (DEM) from a pushbroom stereo pair. An inverse geolocation algorithm for extracting GCPs from ERS SAR data and the SRTM DEM was recently developed. However, not all GCPs established by this method are accurate enough for direct application to the geometric correction of pushbroom images such as SPOT, IRS, etc, and thus a method for selecting and removing inaccurate points from the sets of GCPs is needed. In this study, we propose a method for evaluating GCP accuracy and winnowing sets of GCPs through orientation modeling of pushbroom image and validate performance of this method using SPOT stereo pair of Daejon City. It has been found that the statistical distribution of GCP positional errors is approximately Gaussian without bias, and that the residual errors estimated by orientation modeling have a linear relationship with the positional errors. Inaccurate GCPs have large positional errors and can be iteratively eliminated by thresholding the residual errors. Forty-one GCPs were initially extracted for the test, with mean the positional error values of 25.6m, 2.5m and -6.1m in the X-, Y- and Z-directions, respectively, and standard deviations of 62.4m, 37.6m and 15.0m. Twenty-one GCPs were eliminated by the proposed method, resulting in the standard deviations of the positional errors of the 20 final GCPs being reduced to 13.9m, 8.5m and 7.5m in the X-, Y- and Z-directions, respectively. Orientation modeling of the SPOT stereo pair was performed using the 20 GCPs, and the model was checked against 15 map-based points. The root mean square errors (RMSEs) of the model were 10.4m, 7.1m and 12.1m in X-, Y- and Z-directions, respectively. A SPOT DEM with a 20m ground resolution was successfully constructed using a automatic matching procedure.

• 한국통신학회:학술대회논문집
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• 한국통신학회 1984년도 춘계학술발표회논문집
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• pp.5-8
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• 1984

Several pitch detection algorithms are studied and compared with the standard pitch detector in a terms of some kinds of errors and each of speaders. Various types of errors are defined, and rank the performance of pitch detectors.

• 한국통신학회:학술대회논문집
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• 한국통신학회 1984년도 춘계학술발표회논문집
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• pp.60-62
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• 1984

Several pitch detection algorithms are studied and compared with the standard pitch detector in a terms of some kinds of errors and each of speaders. Various types of errors are defined, and rank the performance of pitch detectors.

• 산업경영시스템학회지
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• 제6권9호
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• pp.35-38
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• 1983

In this paper major subject is to investigate the measurement errors affecting on the determination of observation numbers, which are required for work measurement, to set up the standard work time. The main consider is, however, with clarification of the differences between measurement errors in case of cycle operation being observed based on the continuous and the work elements observation.

• Journal of the Korean Data and Information Science Society
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• 제24권4호
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• pp.885-893
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• 2013

This paper considers Bayes estimations of the small area means under Fay-Herriot model with measurement errors. We provide empirical Bayes predictors of small area means with the corresponding jackknifed mean squared prediction errors. Also we obtain hierarchical Bayes predictors and the corresponding posterior standard deviations using Gibbs sampling. Numerical studies are provided to illustrate our methods and compare their eciencies.

• 대한산업공학회지
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• 제17권2호
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• pp.97-105
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• 1991

In developing a regression relationship for a standard data system in work measurement, job characteristics are frequently measured with error when measurements are made in the field under less controlled conditions or when accurate instruments are not available. This paper concerns with the prediction of the total task time when job characteristics are measured with error. Integrated mean square error of prediction(IMSE) is developed as a measure of the effect of errors in job characteristics on the predicted total task time. By evaluating how IMSE is affected by the measurement error in each job characteristic, we can determine which error should be controlled to develop a desirable standard data system.

• 한국잠사곤충학회지
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• 제15권1호
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• pp.27-30
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• 1973

본 연구는 조사검정의 정도를 높이고 또한 조사검정을 보다 효율적으로 수행하는데 기여하기 위한 기초자료를 얻고자 하였던바 다음과 같은 결과를 얻었다. 1. 검정시료량에 대한 해서율 및 생사량비율의 표준편차와 변이계수는 시료량의 증가에 따라서 점차감소하는 경향을 보였는데 300입이상의 시험구에서는 시료량의 다소에 따른 유의차를 인정할 수 없었다. 2. 해서율에 대한 표준오차는 300 입구와 400 입구간의 유의차를 인정할 수 없었다. 3. 생사량비율에 대한 표준오차는 300 입구와 500 입구 및 600 입구간의 유의차를 인정할 수 없었다. 4. 견사장에 대한 표준편차, 표준오차 및 변이계수는 시료량의 다소에 따론 유의차를 인정할 수 없었다. 5. 이상의 연구결과를 종합하여 볼때 견사검정에 있어서의 적정시료량은 300입으로 추정된다.

• 한국연초학회지
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• 제22권1호
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• pp.91-98
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• 2000

This study was carried out to evaluate the uncertainty in the analysis of menthol content from the mentholated cigarette. Menthol in the sample cigarette was extracted with methanol containing an anethole as an internal standard, and then analyzed by gas chromatography. As the sources of uncertainty associated with the analysis of menthol, were the following points tested, such as the weighing of sample, the preparation of extracting solution, the pipetting of extracting solution into the sample, the preparation of standard solution, the precision of GC injections for standard & sample solution, the GC response factor of standard solution, the reproducibility of menthol analysis, and the determination of water content in tobacco, etc. For calculating the uncertainties, type A of uncertainty was evaluated by the statistical analysis of a series of observation, and type B by the information based on supplier's catalogue and/or certificated of calibration. Sources of uncertainty were subsequently included and mathematically combined with the uncertainty arising from the assessment of accuracy to provide the overall uncertainty. It was shown that the main source of uncertainty came from the errors in the reproducibility of menthol and water determination, the purity of menthol reference material in the preparation of standard solution, and the precision of GC injections for sample solution. The errors in sample weighing and volume measurement contributed relatively little to the overall uncertainty. The expanded uncertainty in the mentholated cigarettes, Korean and American brand, at 0.95 level of statistical confidence was $\pm$0.06 and $\pm$0.07 mg/g for a menthol content of 1.89 and 2.32 mg/g, respectively.

• 한국세라믹학회지
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• 제33권8호
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• pp.928-934
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• 1996

X-선 형광분석법을 사용하여 표준검정곡선법으로 시멘트 중의 주, 부성분들을 정량하고 습식법과 분석결과를 비교하였다. 이때, 표준시료 및 미지시료는 용융 케스트 비드법으로 준비하였다. 표준시멘트(227A372)의 오차분석결과 주성분인 CaO, SiO2, Al2O3, Fe2O3 및 부성분중의 MgO, SrO는 상대오차가 1% 이내이었으며, 부성분중 So3, K2O, TiO2, Na2O P2O5 및 Mn2O3는 5% 이하의 상대오차를 가졌다. 부성분의 상대오차는 시료준비오차가 가장 큰 부분을 차지하였다. X-선 형광분석과 습식분석을 비교한 결과 시멘트 분석의 측정값간의 최대혀용범위를 만족하므로, X-선 형광분석법을 시멘트 화학분석에 적용할 수 있을 것으로 판단된다. 그리고, 기존의 습식법으로 분석하기 어려운 시멘트내에 존재하는 미량성분인 P2O5, SrO 및 Mn2O3 의 정밀정확한 분석 또한 가능하였다.