• Title/Summary/Keyword: HoQ

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Optimization research of decoupling capacitor and practical using q-factor (Decoupling capacitor의 최적화 연구 및 Q-factor의 활용)

  • Kim, June-Ho;Yu, Jin-Keon;Kim, Byung-Ki;Nah, Wan-Soo
    • Proceedings of the KIEE Conference
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    • 2009.07a
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    • pp.2205_2206
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    • 2009
  • Decoupling capacitor는 Power Plane의 특정 주파수 대역에서 Anti-resonance가 발생, 전력 전달에 저해가 될 시에 부착되어 원활한 전력전달을 하기위한 도구로 많이 사용되어 왔다. 하지만 De-cap(Decoupling capacitor)을 어느 위치에 어떤 용량으로 부착하여야 하는지 문제점이 제기되고 이를 해결하기 위해 무작정 설치하여 보는 번거로움이 있었다. 본 문에서는 De-cap의 적절한 사용법에 대한 방법과 Q-factor의 적용법을 제시한다.

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Ecological Niche Breadth of Q. mongolica and Overlap with Q. acutissima and Q. variabilis along with Three Environment Gradients (세 가지 환경구배에 따른 신갈나무의 생태적 지위폭과 상수리나무, 굴참나무와의 생태적 중복역)

  • Lee, Ho-Jong;You, Young-Han
    • Korean Journal of Environmental Biology
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    • v.27 no.2
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    • pp.191-197
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    • 2009
  • In order to characterize the ecological traits of Q. mongolica, we treated the seedlings of this species with three environmental factors, light, moisture and nutrient gradients from March to October 2007, and measured morphological and ecological 17 characters. Lastly calculated ecological niche breadth and niche overlap between Q. mongolica-Q. acutissima and Q. mongolica-Q. variabilis, and analysed them with a special reference to ecological distribution pattern and their competition relationship in Korea. The ecological niche breadth of Q. mongolica showed the lowest in nutrient treatment, but the highest in soil moisture treatment. The ecological niche value under light was intermediate. On comparison of the ecological niche breadth of three oak species, Q. mongolica showed the highest in light environment, which might be a reason for the dominant distribution in the forest plant community, Korea. The ecological niche overlap of Q. mongolica-Q. acutissima and Q. mongolica-Q. varabilis was the widest in moisture treatment, but the narrowest in nutrient treatment and the intermediate in light one. These results means that these three oak species be most competitive in moisture environment than light or nutrient one, and that there are least differentiated among oak species for soil moisture condition. Cluster and PCA ordination showed that Q. mongolica and Q. acutissima were more closely arranged than Q. mongolica and Q. variabilis. From these results, it can be explained that Q. mongolica have more similar ecological niche with Q. acutissima than with Q. variabilis, consequently competition between Q. mongolica and Q. acutissima is intensive than Q. mongolica and Q. variabilis for environment condition, especially in soil moisture.

Partial Discharge Pattern Recognition using Neural Network (뉴우럴 네트워크에 의한 부분방전 패턴 인식)

  • Lee, June-Ho;Hozumi, Naohiro;Okamoto, Tatsuki
    • Proceedings of the KIEE Conference
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    • 1995.07c
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    • pp.1304-1306
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    • 1995
  • In this study, a neural network algorithm through a data standardization method was developed to discriminate the phase-shifted partial discharge(PD) patterns such as a $\phi$-q-n pattern. Considering the PD measurement in the field, it is not so easy to acquire absolute phase angles of PD pulses. As a consequence, one of the significant problems to be solved in applying the neural network algorithm to practical systems is to develop a method that can discriminate phase-shifted $\phi$-q-n patterns. Therefore, authors established a new method which could convert phase-shifted $\phi$-q-n patterns to a standardized $\phi$-q-n pattern which was not influenced by phase shifting. This new standardization method improved the recognition performance of a neural network for the phase-shifted $\phi$-q-n patterns considerably.

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The research on the AC machine modeling using the d-q transform (d - q 변환을 이용한 교류기 모델링에 관한 연구)

  • Park, Jin-Ho;Hong, Sun-Ki;Kim, Beom-Hun
    • Proceedings of the KIEE Conference
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    • 2011.07a
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    • pp.1878-1879
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    • 2011
  • 주로 사용하는 3상 교류 전동기는 3상의 전압, 전류가 인가되며, 이 3상인 a, b, c상 변수들을 변환하여 d. q, 0축으로 이루어진 직교 좌표계상의 변수로 변환하는 것을 좌표 변환 이라고 하며 통상적으로 교류기의 모델링 또는 해석 시 이 방식을 통하여 실행한다. 기본적으로 좌표 변환 즉 d - q변환은 사용하나 그 이후에 d축과 q축의 전류와 자속쇄교수 구해가는 방식과 d축과 q축을 해석하는 관점의 변화에 따라 모델링에 사용되는 수식이 변환하며 이러한 수식들을 활용하여 모델링을 함으로써 서로의 장단점을 비교하며, 그 비교를 통하여 교류기에 이론적으로 더 근접하고 단순화된 모델링에 대해 연구했다. 그래서 본론에서는 3가지 모델링을 비교한다. 각각의 모델링마다의 장점과 단점이 있으며 그러한 장단점을 비교하여 교류기에 더 근접한 모델링을 결정했다.

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CODES OVER POLYNOMIAL RINGS AND THEIR PROJECTIONS

  • Park, Young Ho
    • Korean Journal of Mathematics
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    • v.17 no.4
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    • pp.385-397
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    • 2009
  • We study codes over the polynomial ring ${\mathbb{F}}_q[D]$ and their projections to the finite rings ${\mathbb{F}}_q[D]/(D^m)$ and the weight enumerators of self-dual codes over these rings. We also give the formula for the number of codewords of minimum weight in the projections.

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Simplistic Determination of Operation Parameters for Simulated Moving Bed (SMB) Chromatography for the Separation of Ketoprofen Enantiomer

  • Park, Tae-Hyun;Yoon, Tae-Ho;Kim, In-Ho
    • Biotechnology and Bioprocess Engineering:BBE
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    • v.10 no.4
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    • pp.341-345
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    • 2005
  • Since it is troublesome to estimate adequate flow rates in four sections of SMB chromatography, a systematic determination of the flow rates has been suggested by using ketoprofen as a model chiral enantiomer. S-ketoprofen. less retained species, was separated from raffinate stream and the variation in its purity was dependent on the changes of the flow rate of section 4 ($Q_4$), the raffinate flow rate ($Q_{raf}$), and the feed flow rate ($Q_{feed}$) under a fixed switch­ing time t$^{\ast}$. When one parameter was changed at the given experimental condition, purities of product were changed and these phenomena has be well explained by the triangle theory.