• Title/Summary/Keyword: statistical method

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Training for Huge Data set with On Line Pruning Regression by LS-SVM

  • Kim, Dae-Hak;Shim, Joo-Yong;Oh, Kwang-Sik
    • Proceedings of the Korean Statistical Society Conference
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    • 2003.10a
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    • pp.137-141
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    • 2003
  • LS-SVM(least squares support vector machine) is a widely applicable and useful machine learning technique for classification and regression analysis. LS-SVM can be a good substitute for statistical method but computational difficulties are still remained to operate the inversion of matrix of huge data set. In modern information society, we can easily get huge data sets by on line or batch mode. For these kind of huge data sets, we suggest an on line pruning regression method by LS-SVM. With relatively small number of pruned support vectors, we can have almost same performance as regression with full data set.

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Empirical Statistical Power for Testing Multilocus Genotypic Effects under Unbalanced Designs Using a Gibbs Sampler

  • Lee, Chae-Young
    • Asian-Australasian Journal of Animal Sciences
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    • v.25 no.11
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    • pp.1511-1514
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    • 2012
  • Epistasis that may explain a large portion of the phenotypic variation for complex economic traits of animals has been ignored in many genetic association studies. A Baysian method was introduced to draw inferences about multilocus genotypic effects based on their marginal posterior distributions by a Gibbs sampler. A simulation study was conducted to provide statistical powers under various unbalanced designs by using this method. Data were simulated by combined designs of number of loci, within genotype variance, and sample size in unbalanced designs with or without null combined genotype cells. Mean empirical statistical power was estimated for testing posterior mean estimate of combined genotype effect. A practical example for obtaining empirical statistical power estimates with a given sample size was provided under unbalanced designs. The empirical statistical powers would be useful for determining an optimal design when interactive associations of multiple loci with complex phenotypes were examined.

Higher Order Statistical Analysis of Sound-Vibration Signal in Rolling Element Bearing with defects (결함이 있는 회전요소 베어링에서 음향-진동 신호의 고차 통계해석)

  • 이해철
    • Proceedings of the Korean Society of Machine Tool Engineers Conference
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    • 1999.10a
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    • pp.49-56
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    • 1999
  • This paper present a study on the application of sound pressure and vibration signals to detect the presence of defects in a rolling element bearing using a statistical analysis method. The well established statistical parameters such as the crest factor and the distribution of moments including kurtosis and skewless are utilized in this study. In addition, other statistical parameters derived from the beta distribution function are also used. A comparison study on the performance of the different types of parameter used is also performed. The statistical analysis is used because of its simplicity and quick computation. Under ideal conditions, the statistical method can be used to identify the different types of defect present in the bearing. In addition, the results also reveal that there is no significant advantages in using the beta function parameters when compared to using kurtosis and the crest factor for detecting and identifying defects in rolling element bearings from both sound and vibration signals.

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Reproducibility of Statistical Motor Unit Number Estimate in Amyotrophic Lateral Sclerosis: Comparisons between Size-and Number-Weighted Modifications (근위축성 측삭 경화증에서의 Statistical Motor Unit Number Estimate 재연성: Size-and Number-Weighted Modifications간의 비교)

  • Kwon, Oh Yun;Lee, Kwang-Woo
    • Annals of Clinical Neurophysiology
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    • v.5 no.1
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    • pp.27-33
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    • 2003
  • Background: Motor unit number estimation (MUNE) can directly assess motor neuron populations in muscle and quantify the degree of physiologic and/or pathologic motor neuron degeneration. A high degree of reproducibility and reliability is required from a good quantitative tool. MUNE, in various ways, is being increasingly applied clinically and statistical MUNE has several advantages over alternative techniques. Nevertheless, the optimal method of applying statistical MUNE to improve reproducibility has not been established. Methods: We performed statistical MUNE by selecting the most compensated compound muscle action potential (CMAP) area as a test area and modified the results obtained by weighted mean surface-recorded motor unit potential (SMUP). Results: MUNE measures in amyotrophic lateral sclerosis (ALS) patients showed better reproducibility with sizeweighted modification. Conclusions: We suggest size-weighted MUNE testing of "neurogenically compensated"CMAP areas present an optimal method for statistical MUNE in ALS patients.

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A Study on the Condition Monitoring for Rolling Element Bearing using Higher Order Statistical Analysis of Sound-Vibration Signal (음향-진동 신호의 고차 통계해석을 이용한 회전요소 베어링의 상황감시에 관한 연구)

  • 이해철;이준서;차경옥
    • Journal of Advanced Marine Engineering and Technology
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    • v.24 no.4
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    • pp.405-413
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    • 2000
  • This paper present study on the application of sound pressure and vibration signals to detect the presence of defects in a rolling element bearing using a statistical analysis method. The well established statistical parameters such as the crest factor and the distribution of moments including kurtosis and skew are utilized in this study. In addition, other statistical parameters derived from the beta distribution function are also used. A comparison study on the performance of the different types of parameter used is also performed. The statistical analysis is used because of its simplicity and quick computation. Under ideal conditions, the statistical method can be used to identify the different types of defect present in the bearing. In addition, the results also reveal that there is no significant advantages in using the beta function parameters when compared to using kurtosis and the crest factor for detecting and identifying defects in rolling element bearings from both sound and vibration signals.

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Review on the Application of Statistical Methods to Maritime Traffic Safety Assessment

  • Gong, In-Young
    • Proceedings of the Korean Institute of Navigation and Port Research Conference
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    • v.1
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    • pp.35-40
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    • 2006
  • For the maritime traffic safety assessment of vessels navigating in harbor or fairway, simulation techniques by using shiphandling simulator system have been traditionally used. When designing the simulation experiments and when analyzing the simulation results, however, there has been a little systematic method. Ship-handling simulations can be regarded as a kind of statistical experiment by using ship-handling simulator system, which means that shiphandling simulation conditions should be designed statistically and that the simulation results should be statistically analyzed as well. For the safe and economic design of harbor and fairway, reasonable decisions based upon the scientific analysis of shiphandling simulation results are indispensable. In this paper, various statistical methods, such as Bayes theorem, statistical hypothesis testing, and probability distributions, are reviewed with a view to application to maritime traffic safety assessment. It is expected that more reasonable decisions on harbor and fairway design can be made from shiphandlers' view point by using statistical methods.

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eXtended Statistical Combination of Uncertainties (XSCU) Method for Digital Nuclear Power Plants

  • In, Wang-Kee;Hwang, Dae-Hyun;Kim, Joon-Sung;Auh, Geun-Sun
    • Nuclear Engineering and Technology
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    • v.30 no.6
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    • pp.617-627
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    • 1998
  • A technically more direct Statistical Combination of Uncertainties (SCU) method, extended SCU (XSCU), was developed to statistically combine the uncertainties associated with the DNBR alarm setpoint and the DNBR trip setpoint of digital nuclear power plants. The Modified SCU (MSCU) method is currently used as the USNRC approved design method to perform the same function. In this study, the MSCU and XSCU methods were compared in terms of the total uncertainties, and the thermal margins to the DNBR alarm and trip setpoints. The MSCU method resulted in small total uncertainties due to large negative biases which are unphysical. The XSCU method gives virtually unbiased total uncertainties which are physically meaningful in order to represent the actual magnitude of the total uncertainties associated with the DNBR alarm and trip setpoints. But the thermal margins to the DNBR alarm and trip setpoints by the MSCU method agree with those by the XSCU method within allowable statistical Variations.

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Prediction of Effective Horsepower for G/T 4 ton Class Coast Fishing Boat Using Statistical Analysis (통계해석에 의한 G/T 4톤급 연안어선의 유효마력 추정)

  • Park, Chung-Hwan;Shim, Sang-Mog;Jo, Hyo-Jae
    • Journal of Ocean Engineering and Technology
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    • v.23 no.6
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    • pp.71-76
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    • 2009
  • This paper describes a statistical analysis method for predicting a coast fishing boat's effective horsepower. The EHP estimation method for small coast fishing boats was developed, based on a statistical regression analysis of model test results in a circulating water channel. The statistical regression formula of a fishing boat's effective horsepower is determined from the regression analysis of the resistance test results for 15 actual coast fishing boats. This method was applied to the effective horsepower prediction of a G/T 4 ton class coast fishing boat. From the estimation of the effective horsepower using this regression formula and the experimental model test of the G/T 4 ton class coast fishing boat, the estimation accuracy was verified under 10 percent of the design speed. However, the effective horsepower prediction method for coast fishing boats using the regression formula will be used at the initial design and hull-form development stage.

Local Influence in Quadratic Discriminant Analysis

  • Jung, Kang-Mo
    • Communications for Statistical Applications and Methods
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    • v.6 no.1
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    • pp.43-52
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    • 1999
  • The local influence method is adapted to quadratic discriminant analysis for the identification of influential observations affecting the estimation of probability density function probabilities and log odds. The method allows a simultaneous perturbation on all observations so that it can identify multiple influential observations. The proposed method is applied to a real data set and satisfactory result is obtained.

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