• 제목/요약/키워드: $C^*$ Estimation

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전자환경 측정에 의한 방전전류 파형추정과 절연진단의 기초 연구 (A Basic Study on the Estimation of Discharge Current Waveform and the Insulation Diagnosis by the Measurement of Electromagnetic Environment)

  • 박광서;김기채;김이국;박원주;이광식
    • 대한전기학회논문지:전기물성ㆍ응용부문C
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    • 제51권10호
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    • pp.492-499
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    • 2002
  • This paper presents the method for an estimation of discharge current waveform in short gap discharge by radiated electromagnetic fields. The method of current waveform estimation is to use the one antenna method (single field method) with a measured electric or magnetic field at given field point by a time domain antenna. In order to verify the availability of the estimation theory, the discharge current waveform estimation was performed by one antenna methods using the measured electric fields of Wilson & Ma and compared with experiments. In addition diagnosis technique for power equipments is able to prevent from large accidents by finding signs of tile accidents before they happen. From the results of the estimation of discharge current, we have a possibility for the application of insulation diagnosis technique for power equipments using S$F_6$ gas. From this point of view, this paper simulated discharge progress and partial discharge by using needle-plan electrodes system in S$F_6$, studied the distribution of frequency spectrum of the radiated electromagnetic waves using a biconical antenna and a spectrum analyzer. From the experimental results of this study, according to the consideration of the mutual relation between frequency spectrum of the radiated electromagnetic waves and discharge progress, it was confirmed that detecting Partial discharge and estimating discharge progress in S$F_6$ could be Possible.

멀티 프로세서 시스템-온-칩(MPSoC)을 위한 버스 매트릭스 구조의 빠르고 정확한 성능 예측 기법 (Fast and Accurate Performance Estimation of Bus Matrix for Multi-Processor System-on-Chip (MPSoC))

  • 김성찬;하순회
    • 한국정보과학회논문지:시스템및이론
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    • 제35권11호
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    • pp.527-539
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    • 2008
  • 본 논문은 큐잉 이론을 이용한 멀티 프로세서 시스템-온-칩(MPSoC)의 버스 매트릭스 기반 통신 구조에 대한 성능 예측 기법을 제안한다. 버스 매트릭스 기반 통신 구조는 다양한 설계 인자를 가지고 있어 이에 대한 성능 최적화는 방대한 설계 공간의 탐색을 필요로 하지만, 현재 널리 사용되고 있는 시뮬레이션에 기반한 방법은 많은 시간을 요하기 때문에 점점 짧아지고 있는 시장 적기 출하(time-to-market) 제약 조건을 만족하기 어렵다. 이러한 문제를 해결하기 위하여 본 논문에서는 시뮬레이션보다 훨씬 빠르면서 정확하게 성능을 예측할 수 있는 기법을 개발하였다. 제안한 성능 분석 기법은 고성능의 버스 매트릭스를 위해 사용되는 버스 프로토콜인 multiple outstanding transaction을 고려한다. 또한 지수 분포(exponential distribution)를 이용하여 비현실적으로 메모리 시스템을 모델하였던 기존의 연구들과 달리 실제적인 메모리 시스템 모델을 위하여 일반 분포(general distribution)를 이용하였다. 제안한 성능 예측 기법의 정확도 및 효율성을 검증하기 위하여 무작위로 생성된 버스 트랜잭션들과 4-채널 DVR 예제에 적용하였을 때, 사이클 단위의 정확도를 갖는 시뮬레이션과 비교하여 $10^5$배 이상 빠르면서 평균 94% 이상의 정확도를 갖는 것으로 분석되었다.

할로겐화합물의 표준생성열의 계산 (Semiempirical Estimation of Standard Enthalpy of Formation for Halogen Substituted Hydrocarbons)

  • 주광열;이필희
    • 대한화학회지
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    • 제24권2호
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    • pp.108-114
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    • 1980
  • 정전기적모델과 결합의 단순한 부가성을 이용하여 아주 극성인 화합물의 표준생성열$({\Delta}H_f\;^{\circ})$를 계산하는 간단한 방법을 제안하였다. 이 ${\Delta}H_f\;^{\circ}$에 대한 할로메탄의 bond 기여도는 각각 ${\Delta}H_f\;^{\circ}(C-F)=-36.44\;kcal/mole,\;{\Delta}H_f\;^{\circ}(C-Cl)=-2.57\;kcal/mole,\;{\Delta}H_f\;^{\circ}(C-Br)=5.32\;kcal/mole,\;{\Delta}H_f\;^{\circ}(C-I)=19.18\;kcal/mole,\;and\;{\Delta}H_f\;^{\circ}(C-H)=-3.61\;kcal/mole$로 얻어졌고 이 갑들과 정전기적 에너지들로부터 계산한 ${\Delta}H_f\;^{\circ}$는 실험치와 잘 일치함을 보였다.

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Sliding Mode Observer (SMO) using Aging Compensation based State-of-Charge(SOC) Estimation for Li-Ion Battery Pack

  • Kim, Jonghoon;Nikitenkov, Dmitry;Denisova, Valeria
    • 전력전자학회:학술대회논문집
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    • 전력전자학회 2013년도 추계학술대회 논문집
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    • pp.200-201
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    • 2013
  • This paper investigates a new approach for Li-Ion battery state-of-charge (SOC) estimation using sliding mode observer (SMO) technique including parameters aging compensation via recursive least squares (RLS). The main advantages of this approach would be low computational load, easiness of implementation along with the robustness of the method for internal battery model parameters estimation. The proposed algorithm was first tested on a set of acquired battery data using implementation in Simulink and later developed as C-code module for firmware application.

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Ground strain estimation for lifeline earthquake engineering

  • Koike, Takeshi;Maruyama, Osamu;Garciano, Lessandro Estelito
    • Structural Engineering and Mechanics
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    • 제25권3호
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    • pp.291-310
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    • 2007
  • Current seismic design guidelines in Japan are diverse in the seismic ground strain estimates, because the concepts on a horizontally propagating wave model are not consistent in various seismic design guidelines including gas, water and other underground structures. The purpose of this study is (a) to derive the analytical methods to estimate the ground strains for incident seismic waves, (b) to develop a statistical estimation technique of the ground strains, and finally (c) to compare the theoretical estimation with the observed data which was measured at 441 sites in the 1999 Chi-Chi Earthquake in Taiwan.

Empirical analysis of equating methods for elective subjects of College Scholastic Ability Test

  • Hyunchul Kim
    • Communications for Statistical Applications and Methods
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    • 제6권3호
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    • pp.977-994
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    • 1999
  • Five equating methos for elective subjects of College Scholastic Ability Test were analyzed under a common-items nonequivalent groups design using a real data set of 110 thousand examinees. Five methods were (a)two-stage linear equating (b) two-stage equi-percentile equating (c) Tucker equating (d) Frequency estimation equating and (e)Braun-Holland equating. The results indicated that Frequency estimation equating fits well and two-stage linear equating produces most different equating results from the Frequency estimation equating.

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웨이블릿 변환을 이용한 시간 지연 추정법 (Time Delay Estimation using Wavelet Transform)

  • 김도형;박영진
    • 한국음향학회:학술대회논문집
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    • 한국음향학회 2000년도 하계학술발표대회 논문집 제19권 1호
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    • pp.165-168
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    • 2000
  • A fast estimation method using wavelet transform for a time delay system is proposed. Main point of this method is to get the wavelet transform of the correlation between the input signal and delayed signal using transformed signals. But wavelet transform using Haar wavelet functions has basis with different phases and can offers a bisection method to estimate a time delay of a signal. Selective computation of the transform of correlation is performed and the computational complexity is reduced. Computational order of this method is O(N log N) and it is much love. than a simple correlation esimation when the length of signal is long.

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Estimation of Initial Concentrations of Phenanthrene and Atrazine from Soil Properties and Bioavailability During Aging

  • Chung, Namhyun
    • Journal of Applied Biological Chemistry
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    • 제44권4호
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    • pp.194-198
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    • 2001
  • Contaminated sites are often abandoned for an extended period of time, thus organopollutants becoming sequestered. The information on the initial concentrations of the contaminants would be helpful for the economic bioremediation of the chemicals. The present study estimated the initial concentrations of atrazine and phenanthrene through multiple regression analyses using soil properties and the amount of chemicals available in situ. Percentage mineralized or extracted was best correlated with organic C or logarithm of organic C, and the $R^2$ values were 0.548 and 0.894 for atrazine and phenanthrene, respectively. Estimation of the initial concentration of the chemicals was then calculated from both the percentage mineralized or extracted and the amount of chemicals extracted or mineralized. Results showed that the estimation of the initial concentration of the chemical at the time of contamination is feasible.

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OFDM 기반 CR 시스템을 위한 부분 주기도표 기반의 저복잡도 주파수 옵셋 추정 기법 (A Low-Complexity Frequency Offset Estimation Scheme Based on Partial Periodogram for OFDM-Based CR Systems)

  • 정다해;박종인;배진수;윤석호
    • 한국통신학회논문지
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    • 제36권10C호
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    • pp.635-640
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    • 2011
  • 본 논문은 직교 주파수 분할 다중화 (orthogonal frequency division multiplexing: OFDM) 기반 인지 무선 (cognitive radio: CR) 시스템을 위한 저복잡도 주파수 옵셋 추정 기법을 제안한다. 제안한 기법은 어떤 종류의 훈련심볼에도 적용할 수 있으며, 부분 주기도표를 이용함으로써 [9]의 기법에 비해 낮은 연산 복잡도를 갖는다. 모의실험을 통해 제안한 기법이 [9]의 기법과 거의 비슷한 추정 성능을 가짐을 보인다.

CPT결과를 이용한 사질토지반에 관입된 짧은 단일말뚝의 극한수평단위지지력 산정 (Estimation of Ultimate Lateral Resistance for Lateral Loaded Short Piles Using CPT Results in Sand)

  • 김민기;황성욱;경두현;이준환
    • 한국지반공학회:학술대회논문집
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    • 한국지반공학회 2008년도 춘계 학술발표회 초청강연 및 논문집
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    • pp.1083-1086
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    • 2008
  • In this study, Estimate solutions of ultimate lateral resistances for lateral loaded piles are proposed using cone penetration values, $q_c$ values, as CPT results. Cone penetration values, $q_c$ values measured on clean sand layers, are represented by factors for relative densities, axial stresses, and lateral stresses which are important on analysis of sandy soil layers. Also, these factors are same factors to consider existed estimations of ultimate lateral capacity. In this study, estimation of ultimate lateral capacity for lateral loaded piles using CPT results is proposed, and this estimation is verified by adequate analysis for effective reliability.

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