• 제목/요약/키워드: Estimating functions

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Length-biased Rayleigh distribution: reliability analysis, estimation of the parameter, and applications

  • Kayid, M.;Alshingiti, Arwa M.;Aldossary, H.
    • International Journal of Reliability and Applications
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    • v.14 no.1
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    • pp.27-39
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    • 2013
  • In this article, a new model based on the Rayleigh distribution is introduced. This model is useful and practical in physics, reliability, and life testing. The statistical and reliability properties of this model are presented, including moments, the hazard rate, the reversed hazard rate, and mean residual life functions, among others. In addition, it is shown that the distributions of the new model are ordered regarding the strongest likelihood ratio ordering. Four estimating methods, namely, method of moment, maximum likelihood method, Bayes estimation, and uniformly minimum variance unbiased, are used to estimate the parameters of this model. Simulation is used to calculate the estimates and to study their properties. Finally, the appropriateness of this model for real data sets is shown by using the chi-square goodness of fit test and the Kolmogorov-Smirnov statistic.

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A study of Efficient Access to homepage

  • Yamagata, Osamu.;Sakamoto, Masahiro.;Tsuda, Kazuo.
    • Proceedings of the IEEK Conference
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    • 2000.07b
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    • pp.707-710
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    • 2000
  • WWW(World wide Web) is a place where many laymen receive and send the information at the worldwide. A visualization of WWW is very important as one of functions helping to retrieve and browse the information. However, as the information volume displayed at one time is limited by a screen size, it is useful to limit the volume of information capable for users to browse. In this report, we propose the page-index, which extract its information according to degree of user’s interest. This index is a numbers, which relate the user’s interest with verbal and structural characteristics of homepages. The homage-index constructed with sequence of this index are useful to help a user’s browsing. We constructed the estimating system about an article of commerce and really tried to estimate. From this trial, we verified the usefulness of the page-index, homepage-index.

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The Vaguelette-Curvelet Decomposition for Image Deblurring

  • Cho, Changhun;Katsaggelos, Aggelos K.;Paik, Joonki
    • IEIE Transactions on Smart Processing and Computing
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    • v.2 no.3
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    • pp.140-147
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    • 2013
  • We present a vaguelette-curvelet decomposition based image deblurring algorithm. We first perform denoising based on the hard-thresholding rule by estimating unknown curvelet coefficients. The proposed algorithm then calculates vaguelette functions by deconvolving the curvelet bases by the point spread function. Vaguelette transform is finally performed to make a clearly restored image. Since the proposed algorithm uses the curvelet transform to sensitively express the edges in all directions, it is possible to restore images with more naturally preserved edges in all directions.

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An Experimental Study on the Creep and Shrinkage for the Segment Concrete in PSC Box Girder Bridge (PSC 박스거더 교량에 사용된 세그먼트 콘크리트의 크리프 및 건조수축에 관한 실험적 연구)

  • 최한태;윤영수;이만섭
    • Journal of the Korea Concrete Institute
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    • v.11 no.3
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    • pp.23-34
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    • 1999
  • In designing PSC box girder bridge, the dead load, prestressing force, creep and shrinkage of concrete are the main factors which influence the camber and deflection of segmental concrete structure under construction. Among these factors the creep and shrinkage are the functions of the time-dependent property which, therefore, must considered with time. The prediction model for estimating creep and shrinkage of concrete has been suggested by ACI, CEB/FIP, JSCE and KSCE design code. In this study the creep and shrinkage test were carried out for four curing ages of concrete which was applied to the pretressed concrete box-girder bridge at a construction site, and the results of test were compared to the values of prediction by the design code. Shrinkage test shows that the test results are similar to KSCE-96 and JSCE-96 but very higher than other prediction model and creep test results are generally similar to ACI-209 and DSCE-96 but lower than other prediction models in contrast to shrinkage test.

Time-dependent Material Properties in FCM Segment of Prestressed Concrete Box-Girder Bridge

  • Yoon, Young-Soo;Choi, Han-Tae;Kwon, Soon-Beom
    • KCI Concrete Journal
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    • v.11 no.3
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    • pp.99-107
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    • 1999
  • In designing the Prestressed concrete box-girder bridge. dead load, prestressing force, creep and shrinkage of concrete are the main factors which influence the camber and deflection of segmental concrete structure under construction. Among these factors the creep and shrinkage are the functions of the time-dependent property which. therefore, must be considered with time. The prediction model for estimating creep and shrinkage of concrete has been suggested by ACI, CEB/FIP, JSCE and KSCE design code and EMM, AEMM, RCM, IDM and SSM has been suggested for analytical method in consideration of time-dependent characteristics. In this study the creep test was carried out for four different curing ages of concrete which were applied to the Prestressed concrete structure at the construction site, and the results of test were compared with the values of creep prediction proposed by the design code. Also the creep test was performed with step-wise incremental stresses and the results were compared to the analytical values.

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Dynamic Analysis of Transverse type Switched Reluctance Motor using Matlab (Matlab을 이용한 횡자속형 SRM의 동특성 해석)

  • Kim, Kyung-Ho;Cho, Yun-Hyun;Jeoung, Yeon-Ho;Kang, Do-Hyun
    • Proceedings of the KIEE Conference
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    • 2000.11b
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    • pp.256-258
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    • 2000
  • This paper is proposed the modeling and computational methods for estimating the steady and dynamic characteristics of a transverse flux type SRM. To obtain characteristics parameters of the transverse flux type SRM which is considered the magnetic non-linearity phenomena. the magnetic equivalent parameters of SRM are computed by the finite element method as functions of the input current and angular displacement. Dynamic characteristics of the designed transverse flux type SRM is simulated and estimated by Matlab/simlunk.

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The Estimation of Link Travel Speed Using Hybrid Neuro-Fuzzy Networks (Hybrid Neuro-Fuzzy Network를 이용한 실시간 주행속도 추정)

  • Hwang, In-Shik;Lee, Hong-Chul
    • Journal of Korean Institute of Industrial Engineers
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    • v.26 no.4
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    • pp.306-314
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    • 2000
  • In this paper we present a new approach to estimate link travel speed based on the hybrid neuro-fuzzy network. It combines the fuzzy ART algorithm for structure learning and the backpropagation algorithm for parameter adaptation. At first, the fuzzy ART algorithm partitions the input/output space using the training data set in order to construct initial neuro-fuzzy inference network. After the initial network topology is completed, a backpropagation learning scheme is applied to optimize parameters of fuzzy membership functions. An initial neuro-fuzzy network can be applicable to any other link where the probe car data are available. This can be realized by the network adaptation and add/modify module. In the network adaptation module, a CBR(Case-Based Reasoning) approach is used. Various experiments show that proposed methodology has better performance for estimating link travel speed comparing to the existing method.

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Empirical Fragility Curves for Bridge (교량의 경험적 손상도 곡선)

  • Lee, Jong-Heon;Kim, Woon-Hak;Choi, Jung-Ho
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.6 no.1
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    • pp.255-262
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    • 2002
  • This paper presents a statistical analysis of empirical fragility curves for bridge. The empirical fragility curves are developed utilizing bridge damage data obtained from the 1995 Hyogoken Nanbu(Kobe) earthquake. Two-parameter lognormal distribution functions are used to represent the fragility curves with the parameters estimated by the maximum likelihood method. This paper also presents methods of testing the goodness of fit of the fragility curves and estimating the confidence intervals of the two parameters(median and log-standard deviation) of the distribution. An analytical interpretation of randomness and uncertainty associated with the median is provided.

Wavelet Estimation of Regression Functions with Errors in Variables

  • Kim, Woo-Chul;Koo, Ja-Yong
    • Communications for Statistical Applications and Methods
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    • v.6 no.3
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    • pp.849-860
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    • 1999
  • This paper addresses the issue of estimating regression function with errors in variables using wavelets. We adopt a nonparametric approach in assuming that the regression function has no specific parametric form, To account for errors in covariates deconvolution is involved in the construction of a new class of linear wavelet estimators. using the wavelet characterization of Besov spaces the question of regression estimation with Besov constraint can be reduced to a problem in a space of sequences. Rates of convergence are studied over Besov function classes $B_{spq}$ using $L_2$ error measure. It is shown that the rates of convergence depend on the smoothness s of the regression function and the decay rate of characteristic function of the contaminating error.

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A Piecewise Weibull Distribution in Reliability and its Estimation (신뢰성이론에서의 피스와이즈 와이블분포와 그 추정)

  • Jeong, Hai-Sung
    • Journal of Korean Society for Quality Management
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    • v.24 no.2
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    • pp.65-76
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    • 1996
  • In general, most industrial products exhibit bath-tub shaped curve for their failure rate functions. This distributional life model can be obtained by the Piecewise Weibull distribution. The least squares, maximum likelihood, and mixed methods of estimating the parameters of the Piecewise Weibull distribution are compared. The comparison is made by using the empirical mean squared errors of (a) the parameter estimates and (b) the estimated change-points, to summarize the results of 1000 simulated samples of three sizes - each 100, 150 and 200. The results are that the mixed method estimation comes to be the best as the sample sizes increase.

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