• Proceedings of the KIEE Conference
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• 1996.07b
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• pp.1359-1361
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• 1996

This paper describes a design of real time fuzzy controller using Minimum fuzzy control Rule Selection Method(MRSM). The control algorithm of dynamic systems needs less computation time and memory. To reduce the computation time of fuzzy logic controller, minimum number of rules are to be selected for the fuzzy input variable. The universe of discourse is divided by the number of linguistic labels to allocate the assigned membership function to the fuzzy input variables. In this case, since fuzzy input variables are continuous, scale factor SU is tuned independently. According to increment of SU control surface is improved to adapt the change of system parameter. At this, crisp control surface is increased. With the increament of crisp control surface, fuzzy control surface is reduced. When error state deviates from desirable error state, crisp control surface is more useful than fuzzy control surface for obtaining fast rising time.

• Current Optics and Photonics
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• v.4 no.4
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• pp.310-316
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• 2020

We propose and experimentally demonstrate an all-optical radio frequency (RF) spectrum broadening system based on time compression. By utilizing the procedure of dispersion compensation values, the frequency domain is broadened by compressing the linear chirp optical pulse which has been multiplexed by the radio frequency. A detailed mathematical description elucidates that the time compression is a very preferred scheme for spectrum broadening. We also report experimental results to prove this method, magnification factor at 2.7, 8 and 11 have been tested with different dispersion values of fiber, the experimental results agree well with the theoretical results. The proposed system is flexible and the magnification factor is determined by the dispersion values, the proposed scheme is a linear system. In addition, the influence of key parameters, for instance optical bandwidth and the sideband suppression ratio (SSR), are discussed. Magnification factor 11 of the proposed system is demonstrated.

• Journal of Families and Better Life
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• v.25 no.6
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• pp.121-131
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• 2007

The purpose of this study was first to reveal the factors of time management behaviors of college students. The second purpose was to examine the effects of those factors on the satisfaction of time management. The data were collected from 400 college students in Seoul by a self-administered questionnaire. Frequencies, Cronbach's alpha, Factor analysis, Pearson's correlation analysis and Multiple linear regression were conducted by SPSS WIN12.0. The major findings were as follows. First, factor analysis of 20 items on the time management behaviors related questions revealed six factors: establishment of standards, reality, overlapping, checking, adjusting and facilitating. Second, many factors such as facilitating, establishment of standards, reality, overlapping were significant in the regression analyses for the satisfaction of time management. Especially, establishment of standards and facilitating had high levels of effort on the satisfaction of time management. In combination, these results suggest that establishment of standards and facilitating are very important factors for high satisfaction of time management.

• Journal of the Korean Home Economics Association
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• v.43 no.11 s.213
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• pp.211-224
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• 2005

The purposes of this study were firstly to reveal the sub-dimensions of time management behaviors and secondly to group workers by time management behaviors. The major findings of this study were as follows. (1)Factor analysis of the 36 items on the time management behaviors instrument revealed three components: factor planning, relations-intention, and urgency. (2)Workers were categorized into four types by the level of those three factors of time management behaviors: 'accomplishment type'($28.31\%$), 'chronic-urgency type'($24.39\%$), 'valuing-job type'($23.73\%$) and 'valuing-human relations type'($23.57\%$). (3)The accomplishment type gained the highest points on the time management satisfaction score, and the level of important${\cdot}$non-urgencies was the highest score, indicating that the accomplishment type had good time management. However, the level of unimportant${\cdot}$urgencies was the highest score. Therefore, this type should try to reduce the level of unimportant${\cdot}$urgencies.

• Journal of Korean Society for Quality Management
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• v.31 no.3
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• pp.193-204
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• 2003

In this paper, we consider a periodic preventive maintenance(PM) policy in which each PM reduces the hazard rate but remains the pattern of hazard rate unchanged. And the system undergoes only minimal repairs at failures between PM's. The expected cost rate per unit time is obtained. The optimal number N of PM and the optimal period x, which minimize the expected cost rate per unit time are discussed. Explicit solutions for the optimal periodic PM are given for the Weibull distribution case.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 1991.10a
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• pp.73-78
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• 1991

In this study of stacked type film chip capacitor, the important parameters are heat-treated temperature, pressure and time. We measured the temperature dependence of dielectric properties and dissipation factor and the frequency dependence of dielectric properties, dissipation factor, ESR(Equivalent Series Resistance) and impedance in stacked type film capacitor. As a result, the best conditions of heat-treated temperature, pressure and time were proved to be 130$^{\circ}C$, 10kg/$\textrm{cm}^2$ and 3hrs, respectively.

• Proceedings of the KIPE Conference
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• 1999.07a
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• pp.126-129
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• 1999

This paper presents a new averaged model for controlled on time boost power factor correction (PFC) circuit. The proposed model accurately predicts the average behavior of the PFC circuit, and offers a good alternative in studying the large signal dynamics of the circuit. The accuracy of the model is verified through both computer simulation and experiments.

• Proceedings of the KIPE Conference
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• 1998.10a
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• pp.642-647
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• 1998

A new small-signal model for the controlled on-time boost power factor correction (PFC) circuit is presented. The proposed small-signal model is valid up to high frequencies over lKHz. The model can be used in designing the voltage feedback compensation of PFC circuits, the control bandwidth of which is maximized with auxiliary means of removing the low-frequency ripple from the output. The accuracy of the model is confirmed by a 200W experimental hardware

• Proceedings of the Korean Society of Developmental Biology Conference
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• 1998.07a
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• pp.63-65
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• 1998

생쥐의 초기발생과정에서 배아 세포질의 제거로 nucleus/cytoplasm ratio를 증가시켰을 경우, 발생과 gene expression에는 영향을 미치지 않았으나 형태형성은 촉진되었다. 또, nucleus/cytoplasm ratio의 변화 없이 발생후기의 cytoplasm으로 일부 치환된 배아에서 발생과 gene expression, 형태형성은 모두 촉진되었다. 이상의 결과로 보아 초기배아의 gene expression과 형태형성과정에서 일어나는 time schedule의 조절은 nucleus/cytoplasm ratio가 직접적으로 영향을 미치지 않고 난자와 배아 내에 존재하는 cytoplasm factor에 의해 조절 받으며, 특히 형태 형성의 time schedule은 cytoplasmic factor와 이들에 의해 조절되는 물질의 상대적인 농도에 의해 조절될 것으로 여겨진다.

• Proceedings of the Korea Institute of Convergence Signal Processing
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• 2001.06a
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• pp.113-116
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• 2001

The conventional K-means algorithm is widely used in vector quantizer design and clustering analysis. Recently modified K-means algorithm has been proposed where the codevector updating step is as fallows: new codevector = current codevector + scale factor (new centroid - current codevector). This algorithm uses a fixed value for the scale factor. In this paper, we propose a new algorithm for the enhancement of learning time in fuzzy c-means a1gorithm. Experimental results show that the proposed method produces codebooks about 5 to 6 times faster than the conventional K-means algorithm with almost the same Performance.