• Title/Summary/Keyword: Variable step

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Variable Selection with Regression Trees

  • Chang, Young-Jae
    • The Korean Journal of Applied Statistics
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    • v.23 no.2
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    • pp.357-366
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    • 2010
  • Many tree algorithms have been developed for regression problems. Although they are regarded as good algorithms, most of them suffer from loss of prediction accuracy when there are many noise variables. To handle this problem, we propose the multi-step GUIDE, which is a regression tree algorithm with a variable selection process. The multi-step GUIDE performs better than some of the well-known algorithms such as Random Forest and MARS. The results based on simulation study shows that the multi-step GUIDE outperforms other algorithms in terms of variable selection and prediction accuracy. It generally selects the important variables correctly with relatively few noise variables and eventually gives good prediction accuracy.

Performance Comparison of Step-Size Update Methods for Modified CMA (변형된 CMA의 수렴상수 갱신 방법의 성능 비교)

  • Oh, Kil-Nam
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.12 no.9
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    • pp.4147-4152
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    • 2011
  • Compared to the constant modulus algorithm (CMA), the modified CMA (MCMA) is easy not only to improve the steady-state performance but also to be expanded to higher-order constellations by using fewer moduli with evenly spaced. In this paper, it is shown that the MCMA is sufficient to achieve satisfactory steady-state performance by applying a variable step-size to the MCMA without switching to an hard decision-directed algorithm. Two new methods varying the step-size are proposed, and the performance improvement of the MCMA with the new methods of variable step-size is presented as compared to the CMA and the fixed step-size MCMA through computer simulations.

On Estimating of Kullback-Leibler Information Function using Three Step Stress Accelerated Life Test

  • Park, Byung-Gu;Yoon, Sang-Chul;Cho, Ji-Young
    • International Journal of Reliability and Applications
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    • v.1 no.2
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    • pp.155-165
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    • 2000
  • In this paper, we propose some estimators of Kullback- Leibler Information functions using the data from three step stress accelerated life tests. This acceleration model is assumed to be a tampered random variable model. Some asymptotic properties of proposed estimators are proved. Simulations are performed for comparing the small sample properties of the proposed estimators under use condition of accelerated life test.

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Kurtosis Driven Variable Step-Size Normalized Least Mean Square Algorithm for RF Repeater

  • Han, Yong-Sik;Yang, Woon-Geun
    • Journal of information and communication convergence engineering
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    • v.8 no.2
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    • pp.159-162
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    • 2010
  • This paper presents a new Kurtosis driven Variable Step-Size Normalized Least Mean Square (KVSSN-LMS) algorithm to prevent repeater from oscillation due to feedback signal of radio frequency (RF) repeater. To get better Mean Square Error (MSE) performance, step-size is adjusted using the kurtosis. The proposed algorithm shows the better performance of steady state MSE. The proposed algorithm shows a better ERLE performance than that of KVSS-LMS, VSS-NLMS, NLMS algorithms.

A LMS algorithm with variable step size (가변 스텝 크기를 갖는 LMS 알고리즘)

  • 김관준;이철희;남현도
    • 제어로봇시스템학회:학술대회논문집
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    • 1993.10a
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    • pp.224-227
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    • 1993
  • In this paper, a new LMS algorithm with a variable step size (VVS LMS) is presented. The change of step size .mu. at each iteration, which increases or decreases according to the misadaptation degree, is computed by a proportional fuzzy logic controller. As a result the algorithm has very good convergence speed and low steady-state misadjustment. The norm of the cross correlation between the estimation error and input signal is used. As a measure of the misadaptation degree. Simulation results are presented to compare the performance of the VSS LMS algorithm with the normalized LMS algorithm.

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A LMS Algorithm with Fuzzy Variable Step Size (퍼지 가변 스텝 크기 LMS 알고리즘)

  • Lee, Chul-Heu;Kim, Koan-Jun
    • Journal of Industrial Technology
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    • v.13
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    • pp.33-41
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    • 1993
  • In this paper, a new LMS algorithm with a fuzzy variable step size (FVS LMS) is presented. The change of step size ${\mu}$, at each iteration which is increases or decreases according to the misadaptation degree, is computed by a proportional fuzzy logic controller. As a result the algorithm has very good convergence speed and low steady-state misadjustment. As a measure of the misadaptation degree, the norm of the cross correlation between the estimation error and input signal is used. Simulation results are presented to compare the performance of the FVSS LMS algorithm with the normalized LMS algorithm.

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Exponentiality Test of the Three Step-Stress Accelerated Life Testing Model based on Kullback-Leibler Information

  • Park, Byung-Gu;Yoon, Sang-Chul;Lee, Jeong-Eun
    • Journal of the Korean Data and Information Science Society
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    • v.14 no.4
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    • pp.951-963
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    • 2003
  • In this paper, we propose goodness of fit test statistics based on the estimated Kullback-Leibler information functions using the data from three step stress accelerated life test. This acceleration model is assumed to be a tampered random variable model. The power of the proposed test under various alternatives is compared with Kolmogorov-Smirnov statistic, Cramer-von Mises statistic and Anderson-Darling statistic.

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The Design of Variable Delay Line Circuit Using Indirect Frequency Synthesizer (간접 주파수 합성기를 이용한 가변 신호지연 회로 설계)

  • 윤영태;민경일;오승협
    • Journal of the Korean Institute of Telematics and Electronics A
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    • v.29A no.2
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    • pp.33-40
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    • 1992
  • The design method of signal delay line system using indirect frequency synthesizer is presented. The variable signal delay line system with 2[nsec] step of delay time at center frequency 60[MHz], bandwidth 500[KHz] and range 5.24-5.81[x10S0-6Tsec] is designed and fabricated. The results were met with good characteristics to be variable delay time of average 2.01[nsec] per step.

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Subband Affine Projection Adaptive Filter using Variable Step Size and Pipeline Transform (가변 적응상수와 파이프라인 변환을 이용한 부밴드 인접투사 적응필터)

  • Choi, Hun;Ha, Hong-Gon;Bae, Hyeon-Deok
    • Journal of the Institute of Electronics Engineers of Korea SP
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    • v.46 no.1
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    • pp.104-110
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    • 2009
  • In this paper, we suggest a new technique which employ the pipelined architecture for the implementation of the SAP adaptive filter using variable step size. According as SAP adaptive filter is sufficiently decomposed, a simplified SAP adaptive filter can be derived, and the weights of adaptive sub-filters can be updated by a simple formular without a matrix inversion. The convergence speed and the steady state error of the simplified SAP adaptive filter are improved by using variable step size. For practical implementation, the simplified SAP adaptive sub-filters are transformed by the pipeline technique.

Variable Step Size Adaptive Algorithm using Instantaneous Absolute Value Based on System Generator (시스템 제너레이터 환경에서 순시 절대값을 이용한 가변스텝사이즈 적응알고리즘)

  • Lee, Chae-Wook;Ryu, Jeong-Tak
    • Journal of Korea Society of Industrial Information Systems
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    • v.21 no.3
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    • pp.1-6
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    • 2016
  • As the convergence speed of time domain adaptive algorithm on the LMS(Least Mean Square) becomes slow when eigen value distribution width is spread, So variable step size algorithm is used widely. But it needs a lot of calculation load. In this paper we consider new algorithm, which can reduce calculations and improve convergence speed, uses instantaneous absolute value of average noise signal adapting the exponential function. For the performance of proposed algorithm is tested and simulated to system generator. As the result we show the variable step size adaptive algorithm in proportion to instantaneous absolute value is more stable and efficient than others.