• 제목/요약/키워드: Estimation algorithm

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유전자 알고리즘을 이용한 유출모형의 매개변수 추정 (Parameter Estimation of Runoff Model Using the Genetic Algorithm)

  • 조현경;이영화
    • 한국환경과학회지
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    • 제12권10호
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    • pp.1109-1116
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    • 2003
  • The genetic algorithm is investigated fer parameters estimation of SED (storage - effective drainage) model from the Wi-stream watershed in Nakdong river basin. In the practical application of model, as a number of watershed parameters do not measure directly, it is desirable to make a good estimation from the known rainfall and runoff data. For the estimation of parameters of the SED model using the genetic algorithm, parameters of Green-Ampt equation(SM, K$\_$s/) for the estimation of an effective rainfall and initial storage(y$\_$in/) used in SED model are obtained a regression equation with 5, 10, 20 days antecedent precipitation. And as a consequence of computation, the parameters were obtained to satisfy the proposed objective function. From the comparison of observed and computed hydrographs, it shows a good agreement in the shape and the rising limb, peak, falling limb of hydrograph, so the SED model using the genetic algorithm shows a suitable model for runoff analysis in river basin.

잡음 ARMA 프로세스의 적응 매개변수추정 (Adaptive Parameter Estimation for Noisy ARMA Process)

  • 김석주;이기철;박종근
    • 대한전기학회논문지
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    • 제39권4호
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    • pp.380-385
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    • 1990
  • This Paper presents a general algorithm for the parameter estimation of an antoregressive moving average process observed in additive white noise. The algorithm is based on the Gauss-Newton recursive prediction error method. For the parameter estimation, the output measurement is modelled as an innovation process using the spectral factorization, so that noise free RPE ARMA estimation can be used. Using apriori known properties leads to algorithm with smaller computation and better accuracy be the parsimony principle. Computer simulation examples show the effectiveness of the proposed algorithm.

Efficient Search Algorithm for Fast Motion Estimation

  • Park, Dong-Min;Kwak, Tong-Ill;Hwang, Bo-Hyun;Yun, Jong-Ho;Choi, Myung-Ryul
    • 한국정보디스플레이학회:학술대회논문집
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    • 한국정보디스플레이학회 2008년도 International Meeting on Information Display
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    • pp.737-740
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    • 2008
  • Block-matching motion estimation plays an important role in video coding. In this paper, we propose an Efficient Search Algorithm for Fast Motion Estimation. The proposed algorithm detects motion variation for reducing computational complexity before determining motion vector. Experimental results show that the proposed algorithm has good performance than conventional algorithms through quantitative evaluation.

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Prony based Multipath Channel Parameter Estimation not Requiring the Number of Received Rays

  • Lim, Jun-Seok;Sung, Koeng-Mo
    • The Journal of the Acoustical Society of Korea
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    • 제15권1E호
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    • pp.65-69
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    • 1996
  • This paper presents an algorithm for multipath channel parameter estimation by an improved Prony method. This algorithm applies a modified regularized spectral estimation to the conventional SVD Prony method. This method requires no a priori information on the number of multipath. The performance of the proposed algorithm is almost the same as that of the SVD based multipath channel parameter estimation algorithm.

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Integer Frequency Offset Estimation of OFDM Systems

  • Yoon, Dae-Gung;Han, Dong-Seog
    • 한국정보기술응용학회:학술대회논문집
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    • 한국정보기술응용학회 2005년도 6th 2005 International Conference on Computers, Communications and System
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    • pp.255-258
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    • 2005
  • A blind-mode integer frequency offset estimation algorithm is proposed for an OFDM system. Imperfect integer frequency offset estimation causes ambiguity in the data sub-carrier position. Morelli's blind integer frequency offiet estimation algorithm exploits the likelihood function by comparing the power in sub-carriers. It, however, shows performance degradation when there is the fractional frequency offset. The proposed algorithm solves this by using interpolation in the frequency domain. In this algorithm, it is exploited that the effect of the frequency offset is shown as a shift of power spectrum. By calculating the covariance of over-sampled samples, most approximate samples to integer point are obtained. It enables integer frequency offset estimation less affected by fractional frequency offset.

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Computational Complexity Analysis of Cascade AOA Estimation Algorithm Based on FMCCA Antenna

  • Kim, Tae-yun;Hwang, Suk-seung
    • Journal of Positioning, Navigation, and Timing
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    • 제11권2호
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    • pp.91-98
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    • 2022
  • In the next generation wireless communication system, the beamforming technique based on a massive antenna is one of core technologies for transmitting and receiving huge amounts of data, efficiently and accurately. For highly performed and highly reliable beamforming, it is required to accurately estimate the Angle of Arrival (AOA) for the desired signal incident to an antenna. Employing the massive antenna with a large number of elements, although the accuracy of the AOA estimation is enhanced, its computational complexity is dramatically increased so much that real-time communication is difficult. In order to improve this problem, AOA estimation algorithms based on the massive antenna with the low computational complexity have been actively studied. In this paper, we compute and analyze the computational complexity of the cascade AOA estimation algorithm based on the Flexible Massive Concentric Circular Array (FMCCA). In addition, its computational complexity is compared to conventional AOA estimation techniques such as the Multiple Signal Classification (MUSIC) algorithm with the high resolution and the Only Beamspace MUSIC (OBM) algorithm.

A Hybrid Estimation of Distribution Algorithm with Differential Evolution based on Self-adaptive Strategy

  • Fan, Debin;Lee, Jaewan
    • 인터넷정보학회논문지
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    • 제22권1호
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    • pp.1-11
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    • 2021
  • Estimation of distribution algorithm (EDA) is a popular stochastic metaheuristic algorithm. EDA has been widely utilized in various optimization problems. However, it has been shown that the diversity of the population gradually decreases during the iterations, which makes EDA easily lead to premature convergence. This article introduces a hybrid estimation of distribution algorithm (EDA) with differential evolution (DE) based on self-adaptive strategy, namely HEDADE-SA. Firstly, an alternative probability model is used in sampling to improve population diversity. Secondly, the proposed algorithm is combined with DE, and a self-adaptive strategy is adopted to improve the convergence speed of the algorithm. Finally, twenty-five benchmark problems are conducted to verify the performance of HEDADE-SA. Experimental results indicate that HEDADE-SA is a feasible and effective algorithm.

Expectation-Maximization 기반의 새로운 OFDM 채널 추정 방식 (A Novel Expectation-Maximization based Channel Estimation for OFDM Systems)

  • 김남겸;손인수;신재호
    • 한국통신학회논문지
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    • 제34권4C호
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    • pp.397-402
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    • 2009
  • 대용량의 데이터 전송을 위해 최근에 많이 사용되고 있는 OFDM 시스템은 다중경로페이딩에는 유리하지만 시간 선택성 페이딩에서는 자유롭지 못하고 이를 위해 채널추정이 필요하게 된다. 이를 위해 본 논문에서는 기존의 EM 알고리즘의 성능을 향상시키기 위해 LPC 알고리즘을 접목시킨 EM-LPC 알고리즘을 제안했다. 이 알고리즘은 기존의 EM 알고리즘의 M-Step 다음에 LPC 알고리즘을 사용하여 미리 다음 pilot 데이터를 추정할 수 있게된다. 또한 interpolation을 통한 데이터 수정도 가능하게 된다. 살펴본 결과 EM-LPC 알고리즘이 기존의 LS 알고리즘과 EM 알고리즘보다 좋은 성능을 내는 것을 볼 수 있었다. 또한 EM 루프의 반복도 역시 줄어드는 것을 볼 수 있었다.

빠른 다단계 연속 제거 알고리즘 (A Fast Multilevel Successive Elimination Algorithm)

  • Soo-Mok Jung
    • 한국컴퓨터산업학회논문지
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    • 제4권10호
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    • pp.761-767
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    • 2003
  • 본 논문에서는 비디오코딩의 움직임 추정을 위한 빠른 다단계 연속제거 알고리즘(FMSEA: Fast Multilevel Successive Elimination Algorithm)을 제안하였다. FMSEA의 움직임 추정 정확도는 Multilevel Successive Elimination Algorithm(MSEA)과 동일하다. 부분 왜곡 제거 기법을 사용하는 FMSEA는 MSEA의 연산량을 효과적으로 줄일 수 있다 실험을 통하여 제안된 알고리즘의 효율성을 확인하였다.

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동영상의 블록내 지역성을 이용하는 효율적인 다단계 연속 제거알고리즘 (An Efficient Multi-level Successive Elimination Algorithm using the Locality in Block)

  • 정수목
    • 디지털산업정보학회논문지
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    • 제5권4호
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    • pp.179-187
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    • 2009
  • In this paper, an efficient multi-level successive elimination algorithm using the locality in block was proposed for motion estimation. If SAD(sum of absolute difference) is calculated from large absolute difference values to small absolute difference values, SAD is increased rapidly. So, partial distortion elimination in SAD calculation can be done very early. Hence, the computations of SAD calculation can be reduced. In this paper, an efficient algorithm to calculate SAD from large absolute difference values to small absolute difference values by using the locality in block. Experimental results show that the proposed algorithm is an efficient algorithm with 100% motion estimation accuracy for the motion estimation of motion vectors.