• 한국시뮬레이션학회:학술대회논문집
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• 한국시뮬레이션학회 1999년도 춘계학술대회 논문집
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• pp.212-216
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• 1999

We propose a method for simulation optimization using stochastic genetic algorithm(GA) to get the best design and operating policies in a Direct-Input-Output Automated Manufacturing System (DIOMS).

• 전기전자학회논문지
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• 제22권1호
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• pp.110-120
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• 2018

본 논문에서는, 볼-빔 시스템에 입-출력 궤환 선형화 기법을 적용하여 추종 궤적 r(t)를 추종하도록 제어기를 설계하였다. 설계한 제어기로 시뮬레이션 및 실험에 적용한 결과, 실험에서 오차가 크게 발생하였다. 이러한 이유는 외란 및 입력정합조건을 만족하지 못해 발생한 것으로 판단되어 볼-빔 시스템의 기존 모델링에서 적절한 외란을 추가하여, 시뮬레이션을 통해 실험 결과와 비슷한 유효한 모델링임을 입증하였다. 그러나, 여전히 저하된 성능으로 인해 bang-bang 제어기를 추가로 적용하였다. 결과적으로, 시스템의 불확실성에 대해 강인하고 향상된 성능을 시뮬레이션 및 실험결과를 통해 검증하였다.

• 한국전기전자재료학회논문지
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• 제21권3호
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• pp.213-216
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• 2008

The voltages for pixel electrodes on LCD panels are supplied with analog voltages from LCD Driver ICs (LDIs). The latest LDI developed for large LCD TV's has suffered from the degradation of analog output characteristics (target voltage: AVO and output voltage deviation: dVO). By the failure analysis, humps in $I_D-V_G$ curves have been observed in high voltage (HV) NMOS devices for input transistors in amplifiers. The hump is investigated to be the main cause of the deviation for the driving current in HV NMOS transistors. It also makes the matching between two input transistors worse and consequently aggravates the analog output characteristics. By simply modifying the active layout of HV NMOS transistors, this hump was removed and the analog characteristics (AVO &dVO) were improved significantly. In the help of the improved analog characteristics, it also became possible to reduce the size of the input transistors less than a half of conventional transistors and significantly improve the integration density of LDIs.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1996년도 하계학술대회 논문집 A
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• pp.376-378
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• 1996

This paper presents a new PFC control method which replaces a fast line current measurement with a filtered load current measurement. Using the power balance relation between the input and the output of the boost converter. the input current can be described as the function of load current. Thus the PWM signal which effects the switching control of the boost converter is generated using the PFC input voltage, the PFC output voltage and the load current as input variables. By using a filter between the bridge rectifier and a dc-to-dc converter, the input voltage of the dc-to-dc converter is forced to always maintain above zero volt. Then the input current traces a sinewave in phase. The proposed scheme accomplishes a very high power factor and a low harmonic distortion of the line current. The validity of this scheme is demonstrated through simulation.

• 한국경영과학회:학술대회논문집
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• 대한산업공학회/한국경영과학회 2000년도 춘계공동학술대회 논문집
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• pp.601-604
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• 2000

In this paper, we compare the classification performance of both data fusion and clustering algorithms (Data Bagging, Variable Selection Bagging, Parameter Combining, Clustering) to logistic regression in consideration of various characteristics of input data. Four factors used to simulate the logistic model are (1) correlation among input variables (2) variance of observation (3) training data size and (4) input-output function. Since the relationship between input & output is not typically known, we use Taguchi design to improve the practicality of our study results by letting it as a noise factor. Experimental study results indicate the following: Clustering based logistic regression turns out to provide the highest classification accuracy when input variables are weakly correlated and the variance of data is high. When there is high correlation among input variables, variable bagging performs better than logistic regression. When there is strong correlation among input variables and high variance between observations, bagging appears to be marginally better than logistic regression but was not significant.

• Nuclear Engineering and Technology
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• 제33권5호
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• pp.457-467
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• 2001

It is well known that the performance of a fuzzy neural network strongly depends on the input features selected for its training. In its applications to sensor signal estimation, there are a large number of input variables related with an output As the number of input variables increases, the training time of fuzzy neural networks required increases exponentially. Thus, it is essential to reduce the number of inputs to a fuzzy neural network and to select the optimum number of mutually independent inputs that are able to clearly define the input-output mapping. In this work, principal component analysis (PCA), genetic algorithms (CA) and probability theory are combined to select new important input features. A proposed feature selection method is applied to the signal estimation of the steam generator water level, the hot-leg flowrate, the pressurizer water level and the pressurizer pressure sensors in pressurized water reactors and compared with other input feature selection methods.

• 기술혁신학회지
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• 제21권4호
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• pp.1313-1344
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• 2018

본 연구는 정부 R&D보조금의 정책적 효과를 규명하기 위해 투입, 관리, 후속, 인지부가성이 산출부가성에 미치는 영향을 규명한다. 또한 투입, 관리, 후속, 인지부가성과 산출부가성의 관계에 대해 정부 R&D보조금 수혜 경험의 조절효과를 분석한다. 실증분석을 위해 연구개발특구 입주기업 중 연구개발특구육성사업에 참여한 경험이 있는 기업을 대상으로 설문조사를 시행하여 수집한 126개 기업의 응답 자료를 분석하였다. 분석결과 투입, 관리, 후속, 인지부가성과 산출부가성의 관계는 모두 긍정적 효과가 있는 것으로 확인되었고, R&D보조금 수혜경험의 조절효과에서는 투입효과성(R&D보조금 ${\times}$ 투입부가성)과 인지효과성(R&D보조금 ${\times}$ 인지부가성)에서 긍정적인 조절효과를 확인하였다. 추가적으로, 종업수가 많을수록, 업력이 낮을수록, NT와 ST산업에서, 첨단기술기업일수록 산출부가성에 긍정적인 영향을 끼치는 것으로 나타났다. 본 연구를 통해 그 동안 국내에서 진행되지 않았던 미시적 관점의 행동부가성에 대한 실증을 실시하여 국내 혁신클러스터 단위에서 투입 행동부가성과 산출부가성관의 관계, R&D보조금 수혜경험의 조절효과를 새롭게 규명하였다.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2000년도 전력전자학술대회 논문집
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• pp.270-273
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• 2000

A new phase shift PWM parallel-input/series-output modularized dual converter is proposed in this paper. This converter is operated with a fixed duty ratio and its output voltage is regulated by phase shift between each module. Since the operating duty ratio of each module is fixed it is sufficient to implement a simple open loop drive circuitry for each module and the cost of total system can be much reduced. The operation of the converter is analyzed in this paper and verified by computer simulation.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1993년도 한국자동제어학술회의논문집(국내학술편); Seoul National University, Seoul; 20-22 Oct. 1993
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• pp.1213-1218
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• 1993

Variable structure control is applied to the robust output tracking control problem of general nonlinear multi-input multi-output (MIMO) systems. Using the concept of relative degree and minimum phase, input/output(I/O) linearization is undertaken. For I/O the linearized system, a new sliding hyperplanes design method is proposed. In this procedure, we can construct very robust and efficient sliding mode controller for general nonlinear systems of relative degree higher than two. The control results are illustrated by adopting a numerical example.

• Journal of the Korean Data and Information Science Society
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• 제18권2호
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• pp.301-314
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• 2007

The aim of this paper is to deal with a method to construct a separate fuzzy regression model with crisp input and fuzzy output data using a best response function for the center and the width of the predicted output. Also we introduce the crisp mean and variance of the predicted fuzzy value and also give some examples to compare a performance of the proposed fuzzy model with various other fuzzy regression model.