• Journal of Electrical Engineering and Technology
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• 제7권3호
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• pp.304-311
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• 2012

So far, the importance for an accurate load model has been constantly raised and its necessity would be further more emphasized. Currently used load model for analysis of power system in Korea was developed 10 years ago, which is aggregated by applying the statistically estimated load compositions to load models based on individual appliances. As modern appliances have diversified and rapidly changed, the existing load model is no longer compatible with current loads in the Korean power system. Therefore, a measurement based load model is more suitable for modern power system analysis because it can accurately include the load characteristics by directly measuring target load. This paper proposes a ZIP model employing a Kalman-filter as the estimation algorithm for the model parameters. The Kamlan-filter based parameter identification offers an advantage of fast parameter determination by removing iterative calculation. To verify the proposed load model, the four-second-interval real data from the Korea Energy Management System (K-EMS) is used.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2001년도 ICCAS
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• pp.157.4-157
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• 2001

An effective approach to detect and diagnose multiple failures in a dynamic system is proposed for the case where the measurement noise is correlated sequentially in time. It is based on the modified interacting multiple-model (MIMM) estimation algorithm in which a generalized decorrelation process is developed by employing the autoregressive (AR) model for the correlated measurement noise. Numerical example for the nuclear steam generator is provided to illustrate the enhanced performance of the proposed algorithm.

• Journal of Electrical Engineering and information Science
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• 제3권2호
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• pp.267-273
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• 1998

This paper introduces an adaptive algorithm determining the measurement-track association problem in multi-target tracking(MTT). We model the target and measurement relationships with mean field theory and then define a MAP estimate for the optimal association. Based on this model, we introduce an energy function defined over the measurement space, that incorporates the natural constraints for target tracking. To find the minimizer of the energy function, we derived a new adaptive algorithm by introducing the Lagrange multipliers and local dual theory. Through the experiments, we show that this algorithm is stable and works well in general environments. Also the advantages of the new algorithm over other algorithms are discussed.

• Communications for Statistical Applications and Methods
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• 제17권3호
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• pp.349-356
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• 2010

The ordinary least squares based estimator of the disturbance variance in a regression model for spatial panel data is shown to be asymptotically unbiased and weakly consistent in the context of SAR(1), SMA(1) and SARMA(1,1)-disturbances when there is measurement error in the regressor matrix.

• 대한산업공학회지
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• 제30권2호
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• pp.84-92
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• 2004

A process control procedure is proposed when 100% inspection is performed in a process with excellent capability. Only the incomplete measurement data is assumed to be available, i.e. the specific measurement value of the quality characteristic is not available for each item but it can be determined to be smaller or larger than any prescribed value. In the suggested model, a signal limit is introduced to determine whether the process under study is in control or not. If the quality characteristic of an incoming item exceeds the upper signal or the lower signal limit, the process is determined to be stopped or not by comparing the number of consecutively accepted items with a predetermined threshold number. The procedure is designed based on the type I and II errors. The performance of the model is evaluated by the expected number of items produced under the in-control and out-of-control states until the process is stopped.

• 한국항공우주학회지
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• 제48권7호
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• pp.489-495
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• 2020

충격파 터널에서 항력 측정을 위하여 가속도계 기반 시스템을 설계 및 구축하고, 마하 6 유동조건에서 원뿔형 모델의 항력계수를 측정하였다. 항력 측정 시스템의 마찰력을 보정하기 위하여 간단하고 직관적인 교정 방식을 제시하고, 항력 측정 결과를 단순 원뿔형 모델의 전산유체역학 해석 결과와 비교, 분석하였다. 다양한 형상의 지지대를 이용하여 지지대에 의한 항력 측정 간섭 영향을 파악하고 이를 최소화하기 위한 디자인을 제시하였다. 수정된 지지대를 이용하여 항력계수를 측정한 결과, 지지대에 의한 항력계수 오차가 작아지는 것이 확인되었다.

• 대한안전경영과학회지
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• 제16권1호
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• pp.239-250
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• 2014

The purpose of this research is to implement and develop the Economic Cost Driver Size(ECDS) extended model to determine the optimal cash driver size with measurement complexity cost and allocation fail cost. ECDS model can be used to seek both measurement accuracy and time efficiency of the Activity-Base Costing (ABC). The study also develops Activity Priority Number (APN) to evaluate the importance of nonvalue-added activities improvement and to determine the representative cost driver of value-added activities when applying ECDS model. APN consists of Severity Priority Number (SPN), Undetectablitiy Priority Number (UPN) and Occurrence Priority Number (OPN). APN can be obtained from lower-stream activity, current activity, upper-stream activity in terms of hierarchical dependency of SIPOC (Supplier, Input, Process, Output, and Customer). In order to seek both efficiency of invested capital and reduction of overhead cost, the paper proposes the integrated ABC and Economic Value Added (EVA) model using redesigned ABC-based statement of comprehensive income and EVA-based statement of financial position. For a better understanding of the proposed ABC-EVA integrated model, numerical examples are demonstrated in this paper. Cost drivers of ABC and capital drivers of EVA in the proposed model can be used to reduce activity overhead cost from ABC-based statement of comprehensive income and to lessen activity capital charge from EVA-based statement of financial position.

• 한국분무공학회지
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• 제20권4호
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• pp.217-222
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• 2015

In this study, Injection rate tests of a Diesel common-rail injector have been performed with injection volume measurement type injection rate test system EMI21 for construction of injector model can be used in an engine calibration mean valued model. The measuring principle of the test system is based on measurement of dispalcement of a movable measurement piston by the volume of fluid released by the injector. From these injection rate test results, the characteristics on shape of instantaneous injection rate and injection fuel amount have been investigated and injection fuel amount calculation equation based on test results has been newly constructed. This equation is very simple and calculation error is less than 5% with test results for wide range injection pressure (200~1800 bar) and injection duration ($200{\sim}1800{\mu}s$) conditions. So, it is anticipated that newly constructed simple injection fuel amount model in this study can be efficiently used on engine calibration and control model.

• 디지털융복합연구
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• 제6권2호
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• pp.157-164
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• 2008

The current research utilized as its target population who are current users of web based information system in Korea. The research validated the dimensions by studying he constructs within the context of the web based information system user population. Correlation was found between Flow dimensions retained as components of a ross-Cultural Model. It was determined that these two dimensions-Intrinsic Interest and Control-are significant predictors of user success. The Cross-Cultural Model was validated, and it is therefore suggested as a basis for further study of user success indicators in he cross-cultural enterprise environment.

• 전기학회논문지
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• 제65권4호
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• pp.652-658
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• 2016

In practical control systems differences between nominal and real systems arise from internal uncertainties and/or external disturbances. This paper presents a model-based low-order disturbance observer for a sinusoidal disturbance with unknown constant offset. By using the disturbance model of a biased harmonic signal, the proposed method can successfully estimate the biased sinusoidal disturbance with unknown amplitude and phase but known frequency. At the first stage of the observer design, a model-based disturbance observer is designed when all the system states are measurable. Next, a sufficient condition is presented for the proposed observer to estimate the sinusoidal disturbance with a minimal-order additional dynamics using only output measurement. Comparative computer simulations are performed to test the performance of the proposed method. The simulation results show the enhanced performance of the proposed disturbance observer.