• Title/Summary/Keyword: LEE Myong-ki

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A Study on the Phonemic Segmentation of an Initial Affricate (초성파찰음의 음소분류에 관한 연구)

  • Kim, Ki-Woon;Lee, Ki-Young;Bae, Chul-Soo;Choi, Kap-Seok
    • Proceedings of the KIEE Conference
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    • 1988.07a
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    • pp.33-36
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    • 1988
  • In this paper, the starting point of affricate is detected from the first predictor coefficient of a 12-pole linear predictive coding (LPC) analysis and phonemic segmentation is done through measuring short time energy and zero crossing rate. By this segmentation method, the duration of an aspirate can be mearsured in order to detect an aspirate or not.

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Fuzzy-Logic Based Service Restoration of Primary Distribution Systems (퍼지 로직을 이용한 배전계통 복구)

  • Lee, Seung-Jae;Lim, Seong-Il;Kim, Ki-Hwa;An, Bok-Shin;Kim, Dae-Hwan
    • Proceedings of the KIEE Conference
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    • 1995.11a
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    • pp.67-70
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    • 1995
  • Service restoration has become more important function in the distribution systems. Conventional scheme considers only the single criterion such as margin, switching number and thus lacks the practical power. This paper proposes a new scheme adopting tile fuzzy decision making technique, general ins a more effective restoration plan.

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A Study on the Phonemic Segmentation by Likelihood Ratio (Likelihood Ratio에 의한 음소분류에 관한 연구)

  • Lee, Ki-Young;Bae, Chul-Soo;Choi, Kap-Seok
    • Proceedings of the KIEE Conference
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    • 1988.07a
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    • pp.20-24
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    • 1988
  • This paper proposed the phonemic segmentation method that employed two types of Likelihood Ratio that measures the change of spectral structure. By this method, isolated digits and words of VCV form are segmented into phoneme-unit and especially, first-burst part in an aspirated bilabial plosive is divided.

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Basic Structure for Hierarchical Adaptive Protection System (적응보호를 위한 계층적 시스템의 기본구조)

  • Lee, Seung-Jae;Kim, Ki-Hwa;Oh, Jung-Hwan;Lim, Dong-Jin
    • Proceedings of the KIEE Conference
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    • 1995.07b
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    • pp.584-587
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    • 1995
  • Recent development in the digital relay technology has introduced the adaptive relaying system which adopts the relays to the current operating states. This paper proposes the hierarchical digital protection system whose design has been based on 154 kV S/S. Applying the newest communication networking, the system provides the new protection capabilities improving the system reliability and speed.

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A Preliminary Design of Fuzzy Protective Relay (Fuzzy 보호계전기의 기본 설계)

  • Lee, Seung-Jae;Kang, Sang-Hee;Kim, Ki-Hwa;Kim, Il-Dong
    • Proceedings of the KIEE Conference
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    • 1996.07b
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    • pp.668-670
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    • 1996
  • The conventional relay which determines the fault state based on the current and voltage has a certain limitations due to the uncertainties involved in the data and the decision making criteria. This study proposes the fuzzy relay applying the Belief-Measure to make a decision on the fault based on the various criteria and integrated data.

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Indole Derivatives I, The Kinetics and Mechanism of the Nucleopilic Addition of Thiourea to 1-Benzylindole-3-Acetophenone (인돌유도체 I, 1-Benzylindole-3-acetophenone유도체에 대한 Thiourea의 친핵성 첨가반응 메카니즘과 그 반응속도론적 연구)

  • Lee, Ki-Chang;Hwang, Sung-Kwu;Ryu, Jung-Wook;Hwang, Young-Hyun;Sung, Ki-Chun
    • Journal of the Korean Applied Science and Technology
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    • v.8 no.2
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    • pp.175-181
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    • 1991
  • The kinetics of the addition of 1-benzylindole-3-(p-substituted) acetophenone derivatives was investigated by ultraviolet spectrophotometery in 30% dioxane -$H_2O\;at\;25^{\circ}C$. A rate equation which can be applied over wide pH range was obtained. The Substituent effects on 1-benzylindole-3-(p-substituted) acetophenone derivatives were studied, and addition were facilitated by electron attracting groups. On the base of the rate equation, substituent effect, and general base effect the plausible addition mechanism was proposed : Below pH 3.0, only neutral thiourea molecule was added to the carbon-carbon double bond, and in the range of pH 0.0${\sim}$14.0, netural thiourea molecule and thiourea anion competitively attacted the double bond. By contrast, above pH 10.0, the reaction was dependent upon only the addition of thiourea anion.

A Study on the Nucleophilic Addition Reaction of L-cysteine for PVS (PVS 유도체에 대한 L-Cysteine의 친핵성 첨가반응에 관한 연구)

  • Lee, Ki-Chang;Lee, Kwang-Iil;Yoon, Chul-Hun;Hwang, Sung-Kwy;Kong, Seung-Dae
    • Journal of the Korean Applied Science and Technology
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    • v.12 no.2
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    • pp.99-105
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    • 1995
  • Phenylvinylsulfone derivatives were synthesized by Kirners condition. The structure of these compounds were ascertained by means of ultraviolet, melting point, IR and $^1H-NMR$ spectra. The nucleophilic addtion reaction kinetics of L-cysteiene for phenylvinylsulfone was investigated by ultraviolet spectrophotometery in 40% $EtOH-H_2O$ at $25^{\circ}C$. The rate equations which were applied over a wide pH $1.0{\sim}13.0$ range. On the basis of general base catalysis and confirmation of addtion reaction product, the nucleophilic addtion reaction kinetics of L-cysteiene for phenylvinylsulfone were measured by the pH change. From the result of the above caption, a plausible nucleophilic addtion reaction mechanism of L-cysteiene for phenylvinylsulfone was proposed. These compounds may by used ad the starting materials for the preparation of the engineering plastics or the germicide.

Nucleophilic Addition Reaction of Thioglycolic acid to 2-Fluorenylidene chalcone Derivatives (2-Fluorenylidene chalcone유도체에 대한 Thioglycolic acid의 친핵성 첨가 반응에 관한 연구)

  • Lee, Ki-Chang;Lee, Kwang-Il;Hwang, Yong-Hyun;Ryu, Jung-Wook;Yoon, Cheol-Hun
    • Journal of the Korean Applied Science and Technology
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    • v.13 no.1
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    • pp.107-113
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    • 1996
  • Fluorenylidene chalcone derivatives were synthesized by condensation. The structure of these compounds were ascertained by means of UV, melting point, IR and $^1H-NMR$ spectra. The nucleophilic addition reaction kinetics of Thioglycolic acid to fluorenylidene chalcone was investigate by UV in 20% $dioxane-H_2O$ at $25^{\circ}C$. The rate equation which were applied over a wide $pH1.0{\sim}13.0$ range. On the basis of general base catalysis and confirmation of addition reaction product, the nucleophilic addtion reaction kinetics of thioglycolic acid to fluorenylidene chalcone were measured by the pH change. From the result of the above caption, a plausible nucleophilic addition reaction mechanism of thioglycolic acid to fluorenylidene chalcone was proposed. These compounds may be used as the starting materials for the preparation of the engineering plastics or the germicide.

Operational Characteristic Analysis of DC Micro-grid with Detail Model of Distributed Generation (분산전원 세부모델을 적용한 DC Micro-grid의 동작특성 분석)

  • Lee, Ji-Heon;Kwon, Ki-Hyun;Lee, Hye-Yeon;Han, Byung-Moon
    • Proceedings of the KIEE Conference
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    • 2008.10c
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    • pp.151-153
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    • 2008
  • DC 마이크로그리드는 태양광과 연료전지와 같은 DC 출력의 분산전원, 풍력이나 가스엔진과 같은 AC 출력의 분산전원이 이차전지나 수퍼커패시터와 같은 에너지 저장장치와 직류로 결합되어 있는 구조로, 최근 급증하고 있는 디지털부하에 고품질, 고신뢰도 전력을 공급하는 새로운 직류배전시스템이다. 본 연구에서는, 먼저 DC 마이크로그리드의 한 시스템 구성을 가정하고, 이들 분산전원과 에너지저장의 컨버터를 제어하는 기법을 제안하였다. 또한 PSCAD/EMTDC 소프트웨어를 사용하여 각각의 분산전원의 세부모델을 구현하고, 이를 DC 마이크로그리드로 구성한 후 분산전원의 생산량, 에너지저장의 저장량, 부하의 소모량, 연계 계통의 공급량을 타당한 시나리오로 가정하여 전체 마이크로그리드의 동작을 분석하였다.

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