• 제목/요약/키워드: power relationship

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Taylor's Power Law and Quasilikelihood

  • Park, Heung-Sun;Cho, Ki-Jong
    • 한국통계학회:학술대회논문집
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    • 한국통계학회 2003년도 추계 학술발표회 논문집
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    • pp.253-256
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    • 2003
  • In ecological studies, animal science, or entomology, the variance of count is considered to have the power of the mean relationship with the mean count as Taylor (1961) presented his famous 'Taylor's Power Law'. In this talk, we are going to review the development of TPL and its extension toward pest management sampling scheme. Different estimation methods are compared. Quasilikelihood approach is suggested to incorporate covariate information. Possible extensions will be discussed.

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다이오드 정류기와 인버터를 이용한 순간 전압 강하 보상기 (Sag Voltage Compensator using Diode Rectifier and Series Inverter)

  • 이준기;박덕희;김희중;한병문;소용철
    • 전력전자학회:학술대회논문집
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    • 전력전자학회 1999년도 전력전자학술대회 논문집
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    • pp.448-451
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    • 1999
  • This paper describes controller development for a dynamic voltage compensator using a shunt diode converter and series inverter. The control system was designed using 1/4 period integrator and vector relationship between the supply voltage and load voltage. A simulation model and scaled hardware model were developed for analyzing performance of the controller and the whole system. Both results confirm that the dynamic compensator can restore the load voltage under the fault of the distribution system.

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실시간 요금 제도 및 기술 전망 (The Perspective on Real Time Pricing)

  • 유인협;이진기;김선익
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 2002년도 하계학술대회 논문집 A
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    • pp.435-437
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    • 2002
  • This Paper presents the technical perspective on the Real Time Pricing(RTP). So far customer has no control on the electricity pricing. But the price hike in California makes changes in the electricity demand and pricing. In such environments. RTP has become an important role in Demand Side Management. Here the system configuration, advantages of RTP are described. Also the relationship between RTP and AMR is considered.

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연삭동력을 이용한 숫돌수명 판정 (Determination of decision of wheel life using grinding power)

  • 이상태
    • 한국공작기계학회:학술대회논문집
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    • 한국공작기계학회 1999년도 추계학술대회 논문집 - 한국공작기계학회
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    • pp.204-209
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    • 1999
  • The dressing time monitoring in cylindrical grinding is very important with respect to machining efficiency. Therefore, the purpose of this paper is to determine the wheel life by monitoring behavior of grinding power for Wa, 19A and GC. For this purpose, we investigated indirectly the attritious wear of grain edge, the loading of grinding wheel and the breakage of grain through the grinding power and the surface roughness under various grinding conditions. From obtained the results, the relationship between the wheel life and the average sectional chip area is examined to guide for the determination of dressing time.

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터빈 발전기 부하용 XLPE 6.6kV 케이블의 절연층 절연상태와 습도의 상관관계 (Relationship Between Humidity and Insulation Status of XLPE 6.6kV Cables for the Load of Electric Turbine Generator)

  • 엄기홍
    • 한국인터넷방송통신학회논문지
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    • 제16권5호
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    • pp.185-190
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    • 2016
  • 국내 발전소에서 운전 중인 XLPE 케이블(또는 CV케이블)은 많은 경우 포설된 지 40년에 이르고 있다. 설치 후 운전 상태에 있는 대부분의 CV 케이블은 6~8년의 기간이 경과하면 열화가 발생하기 시작하고, 근래에 포설한 케이블이라 할지라도 사고가 발생할 수가 있으며, 사고 발생으로 인하여 막대한 손실을 초래하게 된다. 사고를 미연에 방지하기 위하여 케이블의 동작상태를 정기적으로 감시 확인하여야 한다. 우리는 케이블의 사고를 체계적으로 감시 및 예방하기 위한 목적으로 측정 시스템을 개발하였다. 이 장비는 수 년 동안 충남 태안에 소재한 한국서부발전주식회사(Korean Western Power Co. Ltd.)에서 케이블의 동작 상태를 감시하고 있다. 이 논문에서 시스템의 기능 및 동작 원리를 소개하고, 터빈 발전기 부하용 XLPE 고압케이블의 절연층 절연상태와 습도의 상간관계를 제시한다.

SP-Creep 시험의 응력 및 변형률 환산에 의한 초임계압 발전설비용 9Cr1Mo강의 크리프 특성 평가 (Creep Characterization of 9Cr1Mo Steel Used in Super Critical Power Plant by Conversion of Stress and Strain for SP-Creep Test)

  • 백승세;박정훈;유효선
    • 대한기계학회논문집A
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    • 제30권9호
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    • pp.1034-1040
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    • 2006
  • Due to the need of increasing thermal efficiency, supercritical pressure and temperature have been utilized in power plants. It is well known that 9Cr1Mo steel is suitable fer use in power plants operating at supercritical conditions. Therefore, to ensure the safety and the soundness of the power plant, creep characterization of the steel is important. In this study, the creep characterization of the gCr1Mo steel using small punch creep(SP-Creep) test has been described. The applied load and the central displacement of the specimen in SP-Creep test have been converted to bearing stress and strain of uc, respectively. The converted SP-Creep curves clearly showed the typical three-stage behavior of creep. The steady-state creep rate and the rupture time of the steel logarithmically changed with the bearing stress and satisfied the Power law relationship. Furthermore, the Larson-Miller parameter of the SP-Creep test agreed with that of the tensile creep test. From the comparison with low Cr-Mo steels, the creep characteristics of 9Cr1Mo steel proved to be superior. Thus, it can be confirmed that the 9Cr1Mo steel is suitable for supercritical power plant.

교과과정으로서의 결혼준비교육 프로그램개발을 위한 기초연구 -W대학교 학생을 중심으로- (A Exploratory Study for the Development of Premarital Preparation Education as Curriculum)

  • 홍달아기;신현실
    • 한국가정과학회지
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    • 제4권2호
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    • pp.29-47
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    • 2001
  • The purpose of this study is to provide marital information that premarital preparation education program is to actively help families happiness, to be reinforced by the developmental service and the protective service. The premarital education program to help unmarried or premarital couples to begin initial adaptation for successful marriage. This program is to enrich the marital relationship provided with the wholesome, potent marital system as center of a family. and further to development preserve. enhance a healthy, genial family relationship. Particularly the elevated marital relationship. The data were collected for 122 collage students. The data were analyzed by statistical methods such as frequency percentage. This program is for college students as curriculum. So it was consisted of fourteen-sessions. The sessions included as follows: Intimacy & Love. Mate Selection. Understanding Together, Communication, Family Stress & Coping, Understanding Marriage & Family Dynamics. Gender Role & Power Intimacy. Sexuality & Relationship. Financial Management, Marriage Preparation. Evaluation.

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OFDM 통신 시스템에서 비선형 증폭기 특성을 고려한 전력 효율과 대역 효율 (Power and Spectrum Efficiencies Considering the HPA Nonlinearity in OFDM Communication System)

  • 이재은;윤기후;이준서;유흥균
    • 한국전자파학회논문지
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    • 제14권6호
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    • pp.543-549
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    • 2003
  • OFDM 시스템뿐만 아니라 통신 시스템에서는 HPA(High Power Amplifier)의 비선형 특성을 고려하는 것이 중요하다. 본 논문에서는 OFDM통신 시스템에서 전력 효율과 대역효율을 동시에 고려한 새로운 성능 평가지수(D)를 분석한다. IBO(Input Backoff)의 크기와 부반송파 수에 따라 다른 값을 갖는 비선형 왜곡 잡음 성분(Nd)을 고려하며, 대역폭의 변화에 따른 대역 효율을 사용하여 성능 지수를 구함으로써 IBO에 대해 서로 상반관계 (tradeoff)에 있는 전력 효율과 대역 효율의 특성을 분석하였다.

Simulation for Pitch Angle Control Strategies of a Grid-Connected Wind Turbine System on MATLAB/Simulink

  • 노경수;최준호
    • 조명전기설비학회논문지
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    • 제21권1호
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    • pp.91-97
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    • 2007
  • This paper presents a pitch angle controller of a grid-connected wind turbine system for extracting maximum power from wind and implements a modeling and simulation of the wind turbine system on MATLAB/Simulink. It discusses the maximum power control algorithm for the wind turbine and presents, in a graphical form, the relationship of wind turbine output, rotor speed, and power coefficient with wind speed when the wind turbine is operated under the maximum power control algorithm. The objective of pitch angle control is to extract maximum power from wind and is achieved by regulating the blade pitch angle during above-rated wind speeds in order to bypass excessive energy in the wind. Case studies demonstrate that the pitch angle control is carried out to achieve maximum power extraction during above-rated wind speeds and effectiveness of the proposed controller would be satisfactory.

데이터 마이닝을 이용한 양방향 전력거래상의 단기수요예측기법 (Short-term demand forecasting method at both direction power exchange which uses a data mining)

  • 김형중;이종수;신명철;최상열
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 2004년도 하계학술대회 논문집 A
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    • pp.722-724
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    • 2004
  • Demand estimates in electric power systems have traditionally consisted of time-series analyses over long time periods. The resulting database consisted of huge amounts of data that were then analyzed to create the various coefficients used to forecast power demand. In this research, we take advantage of universally used analysis techniques analysis, but we also use easily available data-mining techniques to analyze patterns of days and special days(holidays, etc.). We then present a new method for estimating and forecasting power flow using decision tree analysis. And because analyzing the relationship between the estimate and power system ceiling Trices currently set by the Korea Power Exchange. We included power system ceiling prices in our estimate coefficients and estimate method.

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