• Title/Summary/Keyword: Recursive Algorithm

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Design of an efficient routing algorithm on the WK-recursive network

  • Chung, Il-Yong
    • Smart Media Journal
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    • v.11 no.9
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    • pp.39-46
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    • 2022
  • The WK-recursive network proposed by Vecchia and Sanges[1] is widely used in the design and implementation of local area networks and parallel processing architectures. It provides a high degree of regularity and scalability, which conform well to a design and realization of distributed systems involving a large number of computing elements. In this paper, the routing of a message is investigated on the WK-recursive network, which is key to the performance of this network. We present an efficient shortest path algorithm on the WK-recursive network, which is simpler than Chen and Duh[2] in terms of design complexity.

Evaluation of Recursive PIV Algorithm with Correlation Based Correction Method Using Various Flow Images

  • Daichin;Lee, Sang-Joon
    • Journal of Mechanical Science and Technology
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    • v.17 no.3
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    • pp.409-421
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    • 2003
  • The hierarchical recursive local-correlation PIV algorithm with CBC (correlation based correction) method was employed to increase the spatial resolution of PIV results and to reduce error vectors. The performance of this new PIV algorithm was tested using synthetic images, PIV standard images of Visualization Society of Japan, real flows including ventilation flow inside a vehicle passenger compartment and wake behind a circular cylinder with riblet surface. As a result, most spurious vectors were suppressed by employing the CBC method, the hierarchical recursive correlation algorithm improved the sub-pixel accuracy of PIV results by decreasing the interrogation window size and Increased spatial resolution significantly. However, with recursively decreasing of interrogation window size, the SNR (signal-to-noise ratio) in the correlation plane was decreased and number of spurious vectors was increased. Therefore, compromised determination of optimal interrogation window size is required for given flow images, the performance of recursive algorithm is also discussed from a viewpoint of recovery ratio and error ratio in the paper.

Development of a Recursive Local-Correlation PIV Algorithm and Its Performance Test

  • Daichin Daichin;Lee Sang Joon
    • 한국가시화정보학회:학술대회논문집
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    • 2001.12a
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    • pp.75-85
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    • 2001
  • The hierarchic recursive local-correlation PIV algorithm with CBC(correlation based correction) method was developed to increase the spatial resolution of PIV results and to reduce error vectors. This new algorithm was applied to the single-frame and double-frame cross-correlation PIV techniques. In order to evaluate its performance, the recursive algorithm was tested using synthetic images, PIV standard images from Visualization Society of Japan, real flows including ventilation flow inside a vehicle passenger compartment and wake behind a circular cylinder with rib let surface. As a result, most spurious vectors were suppressed by employing CBC method. In addition, the hierarchical recursive correlation algorithm improved largely the sub-pixel accuracy of PIV results by decreasing the interrogation window size, increasing spatial resolution significantly.

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Adaptive System Identification Using an Efficient Recursive Total Least Squares Algorithm

  • Choi, Nakjin;Lim, Jun-Seok;Song, Joon-Il;Sung, Koeng-Mo
    • The Journal of the Acoustical Society of Korea
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    • v.22 no.3E
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    • pp.93-100
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    • 2003
  • We present a recursive total least squares (RTLS) algorithm for adaptive system identification. So far, recursive least squares (RLS) has been successfully applied in solving adaptive system identification problem. But, when input data contain additive noise, the results from RLS could be biased. Such biased results can be avoided by using the recursive total least squares (RTLS) algorithm. The RTLS algorithm described in this paper gives better performance than RLS algorithm over a wide range of SNRs and involves approximately the same computational complexity of O(N²).

An Efficient Recursive Total Least Squares Algorithm for Training Multilayer Feedforward Neural Networks

  • Choi Nakjin;Lim Jun-Seok;Sung Koeng-Mo
    • Proceedings of the Acoustical Society of Korea Conference
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    • autumn
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    • pp.527-530
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    • 2004
  • We present a recursive total least squares (RTLS) algorithm for multilayer feedforward neural networks. So far, recursive least squares (RLS) has been successfully applied to training multilayer feedforward neural networks. But, when input data contain additive noise, the results from RLS could be biased. Such biased results can be avoided by using the recursive total least squares (RTLS) algorithm. The RTLS algorithm described in this paper gives better performance than RLS algorithm over a wide range of SNRs and involves approximately the same computational complexity of $O(N^{2})$.

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Recursive Morphological Hybrid Median Filter (반복적 수리 형태학을 이용한 하이브리드 메디안 필터)

  • 정기룡
    • Journal of the Korean Institute of Navigation
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    • v.20 no.4
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    • pp.99-109
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    • 1996
  • Though median filter is used for removing noise and smoothing image. But, the result of it has distortion around edge. And then, this paper proposes new noise removing algorithm by recursive morphological processing. Basic operation is same each other, but there is some different processing method between recursive morphology and general morphology theory. This recursive morphological filter can be viewed as the weighted order static filter, and then it has a weighted SE(structuring element). Especially using this algorithm to remove the 10% gaussian noise, this paper confirmed that PSNR is improved about 0.642~1.5757 db reserving edge well better than the results of the traditional median filter.

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A novel recursive stochastic subspace identification algorithm with its application in long-term structural health monitoring of office buildings

  • Wu, Wen-Hwa;Jhou, Jhe-Wei;Chen, Chien-Chou;Lai, Gwolong
    • Smart Structures and Systems
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    • v.24 no.4
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    • pp.459-474
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    • 2019
  • This study develops a novel recursive algorithm to significantly enhance the computation efficiency of a recently proposed stochastic subspace identification (SSI) methodology based on an alternative stabilization diagram. Exemplified by the measurements taken from the two investigated office buildings, it is first demonstrated that merely one sixth of computation time and one fifth of computer memory are required with the new recursive algorithm. Such a progress would enable the realization of on-line and almost real-time monitoring for these two steel framed structures. This recursive SSI algorithm is further applied to analyze 20 months of monitoring data and comprehensively assess the environmental effects. It is certified that the root-mean-square (RMS) response can be utilized as an excellent index to represent most of the environmental effects and its variation strongly correlates with that of the modal frequency. More detailed examination by comparing the monthly correlation coefficient discloses that larger variations in modal frequency induced by greater RMS responses would typically lead to a higher correlation.

An Efficient Parallel Simulation Algorithm on Recursive Feedforward Network (Recursive Feedforword Network 상에서의 효율적인 병렬 시뮬레이션 알고리즘)

  • 옥시건
    • Journal of the Korea Society for Simulation
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    • v.4 no.2
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    • pp.79-92
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    • 1995
  • In this paper we present an efficient parallel simulation algorithm in recursive feedforward network(RFN) which can reduce the simulation delay while decreasing the number of null messages compared to the previous result. As a preprocessing step, we first determine the group and type of each oupput channel for the nodes using DFS(Depth First Search) algorithm, and show that the number of null messages as well as the simulation scheme. By the new scheme we decide if null messages are sent to the output channels or not according to the group to which it belongs.

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Recursive approximate overdetermined ARMA spectral estimation (순환 근사 과결정 ARMA 스펙트럼 추정)

  • 이철희;이석원;양흥석
    • 제어로봇시스템학회:학술대회논문집
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    • 1987.10b
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    • pp.446-450
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    • 1987
  • In this paper, overdetermined method is used for high resolution spectral estimation in case of short data record length. To reduce the computational effort and to obtain recursive form of estimation algorithm, we modify data matrix to have near-Toeplitz structure. Then, new recursive algorithm is derived in the form of fast Kalman algorithm. Two stage procedure is used for the estimation of ARMA parameters. First AR parameters are estimated by using overdetermined modified Yule-walker equation, and then MA parameters are implicitly estimated by estimating numerator spectral coefficients(NS).

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A New Recursive Least-Squares Algorithm based on Matrix Pseudo Inverses (ICCAS 2003)

  • Quan, Zhonghua;Han, Soo-Hee;Kwon, Wook-Hyun
    • 제어로봇시스템학회:학술대회논문집
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    • 2003.10a
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    • pp.927-931
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    • 2003
  • In this paper, a new Recursive Least-Squares(RLS) algorithm based on matrix pseudo-inverses is presented. The aim is to use the proposed new RLS algorithm for not only the over-determined but also the under-determined estimation problem. Compared with previous results, e.g., Jie Zhou et al., the derivation of the proposed recursive form is much easier, and the recursion form is also much simpler. Furthermore, it is shown by simulations that the proposed RLS algorithm is more efficient and numerically stable than the existing algorithms.

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