• Title/Summary/Keyword: Fast Convergence

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Research on the Improvement of Convergence Characteristics of the Fast Decoupled Load Flow (고속분할법의 수렴특성 개선에 관한 연구)

  • Lee, In-Yong
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.25 no.5
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    • pp.403-408
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    • 2012
  • In this paper, we propose useful load flow algorithms called FEDL (fast enhanced decoupled load flow). The proposed load flow method can improve the convergence characteristics particularly when the P-Q coupling becomes significant and the power system operating states deviate from the conditions required for stable convergence of the FDL by reflecting in part the effects of the off-diagonal terms in the Jacobian. In our test with IEEE AEP-30 bus system and RTS-96 73-bus system, it converge even when the fast decoupled load flow (FDL) and its variations keeping load flow matrices constant experience convergence problems. Test results show promising performances of the proposed algorithms in their convergence characteristics both in number of iterations and overall convergence speeds.

Modification of the Reference Signal for Fast Convergence in LMS-based Adaptive Equalizers (LMS 기반 적응 등화기에서 빠른 수렴을 위한 기준신호 변형)

  • 이기헌;최진호;박래홍;송익호;박재혁;이병욱
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.19 no.5
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    • pp.939-951
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    • 1994
  • In adaptive equalizers based on least mean squares (LMS) algorithms, the convergence rate is determined by the convariance matrix of an input signal. When the eigenvalue spread of the convariance matrix is close to unity, the convergence rate is quite fast. In this paper, for fast convergence of LMS-based adaptive equalizers we propose a modified reference signal pertinent to the statistical channel. From the theoretical analysis and computer simulation, it is shown that the proposed modification method is quite effective for fast convergence of LMS-based adaptive equalizers.

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fast running FIR filter structure based on Wavelet adaptive algorithm for computational complexity (웨이블렛 기반 적응 알고리즘의 계산량 감소에 적합한 Fast running FIR filter에 관한 연구)

  • Lee, Jae-Kyun;Lee, Chae-Wook
    • Proceedings of the Korea Institute of Convergence Signal Processing
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    • 2005.11a
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    • pp.250-255
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    • 2005
  • In this paper, we propose a new fast running FIR filter structure that improves the convergence speed of adaptive signal processing and reduces the computational complexity. The proposed filter is applied to wavelet based adaptive algorithm. Actually we compared the performance of the proposed algorithm with other algorithm using computer simulation of adaptive noise canceler based on synthesis speech. As the result, the frequency domain algorithm is prefer than the existent time domain. we analyzed the Wavelet algorithm, short-length fast running FIR algorithm, fast-short-length fast running FIR algorithm and proposed algorithm.

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A Fast Algorithm for Real-time Adaptive Notch Filtering

  • Kim, Haeng-Gihl
    • Journal of information and communication convergence engineering
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    • v.1 no.4
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    • pp.189-193
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    • 2003
  • A new algorithm is presented for adaptive notch filtering of narrow band or sine signals for embedded among broad band noise. The notch filter is implemented as a constrained infinite impulse response filter with a minimal number of parameters, Based on the recursive prediction error (RPE) method, the algorithm has the advantages of the fast convergence, accurate results and initial estimate of filter coefficient and its covariance is revealed. A convergence criterion is also developed. By using the information of the noise-to-signal power, the algorithm can self-adjust its initial filter coefficient estimate and its covariance to ensure convergence.

Fast short length running FIR structure in discrete wavelet adaptive algorithm

  • Lee, Chae-Wook
    • Journal of the Institute of Convergence Signal Processing
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    • v.13 no.1
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    • pp.19-25
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    • 2012
  • An adaptive system is a well-known method for removing noise from noise-corrupted speech. In this paper, we perform a least mean square (LMS) based on wavelet adaptive algorithm. It establishes the faster convergence rate of as compared to time domain because of eigenvalue distribution width. And this paper provides the basic tool required for the FIR algorithm whose algorithm reduces the arithmetic complexity. We consider a new fast short-length running FIR structure in discrete wavelet adaptive algorithm. We compare FIR algorithm and short-length fast running FIR algorithm (SFIR) to the proposed fast short-length running FIR algorithm(FSFIR) for arithmetic complexities.

FC-MMA Adaptive Equalization Algorithm to improve the Convergence Speed of MMA in 16-QAM System (16-QAM 시스템에서 MMA의 수렴 속도를 개선시킨 FC-MMA 적응 등화 알고리즘)

  • Lim, Seung-Gag
    • The Journal of the Institute of Internet, Broadcasting and Communication
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    • v.14 no.1
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    • pp.93-99
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    • 2014
  • This paper deals with the FC-MMA (Fast Convergence-Multi Modulus Algorithm) which is improving the convergence characteristics of the MMA (Multiple Modulus Algorithm) adaptive equalization algorithm that is used for the minimization of the intersymbol interference which occurs in the time dispersive communication channel. In the time varying charateristics and the abnormal situation like as outage of the communication channel, the adaptive equalizer needs to adapting the new environment more rapidly. For this problem, the residual isi and the maximum distortion performance index which are meaning the convergence characteristics are widely adapted in the adaptive equalizer. The 16-QAM signal is transmitted and it was confirmed that the proposed algorithm, the FC-MMA has the fast convergence performance such as in the 1.75 times fast in residual isi and 2.5 times fast in the maximum distortion in order to reaching the steady state compare to the MMA algorithm in the same channel environment by the computer simulation.

GPS L5 Acquisition Schemes for Fast Code Detection and Improved Doppler Accuracy

  • Joo, In-One;Sin, Cheon-Sig;Lee, Sang-Uk;Kim, Jae-Hoon
    • ETRI Journal
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    • v.32 no.1
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    • pp.142-144
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    • 2010
  • In this letter, we propose GPS L5 acquisition schemes to detect a fast code phase and improve the accuracy of the Doppler frequency. The proposed approach is based on the code-phase changes which occur during the acquisition processing time originating in the Doppler frequency. The proposed schemes detect a fast code phase within about 1 chip near the estimated code phase and improve the accuracy of the Doppler frequency by up to about 4 times in comparison with the popular Septentrio receiver. The feasibility of the proposed schemes is demonstrated through simulation.

Adaptive Time-delayed Control with Integral Sliding-mode Surface for Fast Convergence Rate of Robot Manipulator (로봇 머니퓰레이터에서의 수렴속도 향상을 위한 적분 슬라이딩 모드 기반 적응 시간 제어 기법)

  • Baek, Jae-Min;Kang, Min-Seok
    • IEMEK Journal of Embedded Systems and Applications
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    • v.16 no.6
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    • pp.307-312
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    • 2021
  • This paper proposes an adaptive time-delayed control approach with the integral sliding-mode surface for the fast convergence rate of robot manipulators. Adaptive switching gain aims to guarantee the system stability in such a way as to suppress time-delayed estimation error in the proposed control approach. Moreover, it makes an effort to increase the convergence ability in reaching the phase. An integral sliding-mode surface is employed to achieve a fast convergence rate in the sliding phase. The stability of the proposed one is proved to be asymptotically stable in the Lyapunov stability. The efficiency of the proposed control approach is illustrated with a tutorial example in robot manipulator, which is compared to that of the existing control approach.

Fast Ray Reordering and Approximate Sibson Interpolation for Foveated Rendering on GPU

  • Kwon, Oh-Seok;park, Keon-kuk;Yoon, Joseph;Kim, Young-Bong
    • Journal of Korea Multimedia Society
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    • v.22 no.2
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    • pp.311-321
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    • 2019
  • Virtual reality applications in Head-Mounted Displays require high frame rates and low latency rendering techniques. Ray tracing offers many benefits, such as high-quality image generation, but has not been utilized due to lower performance than rasterization. But that can obtain good result combined with gaze-tracking technology and human visual system's operation principle. In this paper, we propose a method to optimize the foveated sampling map and to maintain the visual quality through the fast voronoi nearest interpolation. The proposed method further reduces the computational cost that has been improved by the previous foveated sampling. It also smoothes the voronoi boundary using adaptive sibson interpolation, which was not possible in real-time. As a result, the proposed method can render real-time high-quality images with low visual difference.

WHEN CAN SUPPORT VECTOR MACHINE ACHIEVE FAST RATES OF CONVERGENCE?

  • Park, Chang-Yi
    • Journal of the Korean Statistical Society
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    • v.36 no.3
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    • pp.367-372
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    • 2007
  • Classification as a tool to extract information from data plays an important role in science and engineering. Among various classification methodologies, support vector machine has recently seen significant developments. The central problem this paper addresses is the accuracy of support vector machine. In particular, we are interested in the situations where fast rates of convergence to the Bayes risk can be achieved by support vector machine. Through learning examples, we illustrate that support vector machine may yield fast rates if the space spanned by an adopted kernel is sufficiently large.