• Title/Summary/Keyword: estimation algorithm

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A Study on State Estimation Algorithm in Power System Using Inverse Lemma (Inverse Lemma를 이용한 상태추정 알고리즘의 개선에 관한 연구)

  • Moon, Y.H.;Park, J.D.;Park, J.K.
    • Proceedings of the KIEE Conference
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    • 1996.11a
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    • pp.182-185
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    • 1996
  • The purpose of slate estimation in power system is to estimate the best-fit Slate variables from the measurements contaminated by various kind of noise. But because the majority of state estimation modules in EMS lack the convergence characteristics, sometimes the desirable outputs can't be obtained. So, in this paper, the new algorithm using the load now output as initial values in the state estimation calculation is proposed to guarantee the convergence. And if the load now outputs were used as the initial values in the calculation, the change in each step would be small compared to the original method using the flat start point. And the Inverse Lemma is used in the algorithm to calculate the new stale in each iteration step for reducing the calculation time. The proposed algorithm was tested on the IEEE 14, 30, 118 bus systems. Eventually, we were able to verity that the differences between the results obtained by the original method and proposed method were relatively small, and the effectiveness of the proposed algorithm increased when applied to the bigger systems.

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An Estimation Algorithm for the Earth Parameter and Resistivity using Artificial Neural Network (신경회로망을 이용한 대지파라미터와 대지저항률 해석 알고리즘)

  • Ryu, Bo-Hyuk;Kim, Jung-Hoon
    • Proceedings of the KIEE Conference
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    • 2005.07a
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    • pp.563-565
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    • 2005
  • In this study, a algorithm to estimate Equivalent earth resistivity and Earth parameter using Artificial Neural Network(ANN) was proposed. Structures of the soil are grouped by using SOM algorithm before estimation. Earth parameter and Equivalent earth resistivity are obtained by using BP algorithm. The effectiveness of the proposed algorithm was verified. In the case study. afterwards, the algorithm proposed in this study will be used in more applications and gained more reliability.

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Adaptive Selection of Fast Block Matching Algorithms for Efficient Motion Estimation (효율적인 움직임 추정을 위한 고속 블록 정합 알고리듬의 적응적 선택)

  • Kim, Jung-Jun;Jeon, Gwang-Gil;Jeong, Je-Chang
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.33 no.1C
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    • pp.19-33
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    • 2008
  • A method that is adaptively selecting among previous fast motion estimation algorithms and a newly proposed fast motion estimation algorithm(UCDS) is presented in this paper. The algorithm named AUDC and a newly proposed fast motion estimation algorithms are based on the Diamond Search(DS) algorithm and Three Step Search(TSS). Although many previous fast motion estimation algorithms have lots of advantages, those have lots of disadvantages. So we thought better adaptive selection of fast motion estimation algorithms than only using one fast motion estimation algorithm. Therefore, we propose AUDC that is using length of the MV, Search Point, SAD of the neighboring block and adaptively selecting among Cross Three Step Search(CTSS), Diamond Search(DS) and Ungraded Cross Diamond Search(UCDS). Experimental results show that the AUDC is much more robust, provides a faster searching speed, and smaller distortions than other popular fast block-matching at algorithms.

Improved Timing Synchronization Algorithm for OFDM Systems (다경로 페이딩 채널에서의 OFDM 심볼 동기 알고리즘)

  • 박병준;고은석;천현수;강창언;홍대식
    • Proceedings of the IEEK Conference
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    • 2000.06a
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    • pp.41-44
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    • 2000
  • In this paper, an improved timing synchronization method for OFDM system is proposed. In multipath fading channels, timing offset estimation algorithm based on simple correlation metric can cause inter-symbol interference (ISI). The proposed algorithm promises accurate timing offset estimation, which can be achieved by simple windowing. The estimation errors in several multipath channels are evaluated in computer simulations.

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Comparison of SRM rotor position estimation algorithm using flux-current methods (자속 모델 기준 추종방식을 이용한 SRM 회전자 위치평가알고리즘 비교)

  • 안재황
    • Proceedings of the KIPE Conference
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    • 2000.07a
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    • pp.697-700
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    • 2000
  • This paper introduces a new rotor position estimation algorithm for the SRM based on the magnetizing curves of aligned and unaligned rotor positions. The flux linkage is calculated by the measured data from phase voltage and phase current and the calculated data are used as the input of magnetizing profiles for rotor position detection. Each of the magnetizing profiles consisted of the methods using the neural network and fuzzy algorithm And also the optima phase is selected by phase selector. To demonstrate the promise of this approach the proposed rotor position estimation algorithms are verified by the experiment results or variable spee range.

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Enhanced Cross Search algorithm using Predicted Motion Vector for Fast Block Motion Estimation

  • Ko, Byung-Kwan;Kwak, Tong-Ill;Hwang, Bo-Hyun;Yun, Jong-Ho;Choi, Myung-Ryul
    • 한국정보디스플레이학회:학술대회논문집
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    • 2008.10a
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    • pp.749-752
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    • 2008
  • Various Motion Estimation (ME) algorithms have been proposed since ME requires large computational complexity. The proposed algorithm employs Enhanced Cross Search Pattern (ECSP) using motion vector of neighbor-blocks to search the motion vector. The experimental results show that proposed algorithm reduces the search point up to 35% compared to conventional methods.

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Maximum Likelihood Estimation for the Laplacian Autoregressive Time Series Model

  • Son, Young-Sook;Cho, Sin-Sup
    • Journal of the Korean Statistical Society
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    • v.25 no.3
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    • pp.359-368
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    • 1996
  • The maximum likelihood estimation is discussed for the NLAR model with Laplacian marginals. Since the explicit form of the estimates cannot be obtained due to the complicated nature of the likelihood function we utilize the automatic computer optimization subroutine using a direct search complex algorithm. The conditional least square estimates are used as initial estimates in maximum likelihood procedures. The results of a simulation study for the maximum likelihood estimates of the NLAR(1) and the NLAR(2) models are presented.

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On A Symbolic Method for Error Estimation of a Mixed Interpolation

  • Thota, Srinivasarao
    • Kyungpook Mathematical Journal
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    • v.58 no.3
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    • pp.453-462
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    • 2018
  • In this paper, we present a symbolic formulation of the error obtained due to an approximation of a given function by the mixed-interpolating function. Using the proposed symbolic method, we compute the error evaluation operator as well as the error estimation at any arbitrary point. We also present an algorithm to compute an approximation of a function by the mixed interpolation technique in terms of projector operator. Certain examples are presented to illustrate the proposed algorithm. Maple implementation of the proposed algorithm is discussed with sample computations.

Mass Estimation of a Permanent Magnet Linear Synchronous Motor by the Least-Squares Algorithm (선형 영구자석 동기전동기의 최소자승법을 적용한 질량 추정)

  • Lee, Jin-Woo
    • Proceedings of the KIPE Conference
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    • 2005.07a
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    • pp.427-429
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    • 2005
  • In order to tune the speed controller in the linear servo applications the accurate information of a mover mass including a load mass is always required. This paper suggests the mass estimation method of a permanent magnet linear synchronous motor(PMLSM) by using the parameter estimation method of Least-Squares algorithm. First, the deterministic autoregressive moving average(DARMA) model of the mechanical dynamic system is derived. The application of the Least-Squares algorithm shows that the mass can be accurately estimated both in the simulation results and in the experimental results.

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A Study on Driver's Perception over the Change of the Headlamp's Illuminance : 4. Development of the Standard and the Algorithm for Limiting Brightness Change (전조등 조도변동에 대한 운전자의 인식연구 : 4. 조도변동 기준 및 평가 알고리즘 개발)

  • Kim, Gi-Hoon;Kim, Huyn-Ji;An, Ok-Hee;Lim, Tae-Young;Min, Jae-Woong;Lim, Jun-Chae;Kang, Byung-Do;Kim, Hoon
    • Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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    • v.21 no.10
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    • pp.13-21
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    • 2007
  • Based on the measurement results, a limit value for the change of the brightness of the headlamp, and an estimation algorithm considering the driver's safety was developed. Limitation values concerning being uncomfortable, blinking, and brightness change were indicated based on a subjective estimation of the psychological estimation. Also a safety estimation algorithm and a limitation value for stopping safely without the threat of obstacles to the vehicle were indicated by the perception measurement.