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Article, Journal of Economics, Business and Law. 2011, 14, p.43-64

Article, Journal of Economics, Business and Law. 2010, 13, p.27-49

Article, Journal of Economics, Business and Law. 2010, 13, p.51-68

application/pdf, Journal of Economics, Business and Law. 2008, 11, p.47-66

Among many dimensional and dimensionless amplitude parameters, Kurtosis (4-th normalized moment of probability density function) is recognized to be the sensitive good parameter for machine diagnosis. Kurtosis has a value of 3.0 under normal condition and the value generally goes up as the deterioration proceeds. But there are cases that kurtosis value goes up and then goes down when damages increase as time passes. In this paper, simplified calculation method of kurtosis is introduced for the analysis of impact vibration including affiliated impact vibration. Affiliated impact vibration is approximated by triangle and simplified calculation method is introduced. Varying the shape of triangle, various models are examined and above phenomenon is traced and its reason is clarified by the analysis. Utilizing this method, the behavior of kurtosis is forecasted and analyzed while watching machine condition and correct diagnosis is executed., Article, Journal of Economics, Business and Law. 2007, 10, p.1-17

Among many amplitude parameters, Kurtosis and Bicoherence are recognized to be the sensitive good parameters for machine diagnosis. In this paper, simplified calculation method of coefficient of autocorrelation function of 1st order lag is introduced, and new deterioration factor of correlation of four variables is introduced consecutively. New deterioration factor is an absolute index of deterioration factor. Compared with the results obtained so far, the new method shows fairly good results. Varying N, the number of data, its characteristics are examined. When N is smaller, sensitivity is better. Therefore this parameter can be used as an index for the machine diagnosis of early failure stage especially., Article, Journal of Economics, Business and Law. 2007, 10, p.19-33

application/pdf, Among many dimensional and dimensionless amplitude parameters, Kurtosis (4-th normalized moment of probability density function) is recognized to be the sensitive good parameter for machine diagnosis. Kurtosis has a value of 3.0 under normal condition and the value generally goes up as the deterioration proceeds. In this paper, simplified calculation method of kurtosis is introduced for the analysis of impact vibration including affiliated impact vibration. Affiliated impact vibration is approximated by triangle and simplified calculation method is introduced. Furthermore absolute deterioration factor is introduced. Varying the shape of triangle, various models are examined. Newly proposed method proved to be a sensitive good index for machine diagnosis., Journal of economics, business and law. 2007, 9, p.17-27

application/pdf, Among many amplitude parameters, Kurtosis (4-th normalized moment of probability density function) is recognized to be the sensitive good parameter for machine diagnosis. On the other hand, new method of machine diagnosis can be considered utilizing higher order cumulants which have the characteristics that cumulants more than 3^ order are 0 under Gaussian distribution. Cumulants are stated in combination with the same order moment and the moments under that order. Simple calculation method is required on the maintenance site. Furthermore, the absolute deterioration factor such as Bicoherence would be much easier to handle because it takes the value of 1.0 under the normal condition and tends to be 0 when damages increase. In this paper, n^ normalized cumulant is considered so as to intensify the sensitivity of diagnosis. Also, simplified calculation method for this new parameter by impact vibration is introduced. Furthermore, absolute deterioration factor is introduced. New calculation method is examined whether it is a sensitive good parameter or not. Compared with the results obtained so far, the new method shows fairly good results., Journal of economics, business and law. 2006, 8, p.25-39

application/pdf, Among many dimensional and dimensionless amplitude parameters, Kurtosis (4-th normalized moment of probability density function) is recognized to be the sensitive good parameter for machine diagnosis. Kurtosis has a value of 3.0 under normal condition and the value generally goes up as the deterioration proceeds. But there are cases that kurtosis value goes up and then goes down when damages increase as time passes. In this paper, simplified calculation method of kurtosis is introduced for the analysis of impact vibration including affiliated impact vibration. Affiliated impact vibration is approximated by triangle and simplified calculation method is introduced. Varying the shape of triangle, various models are examined and above phenomenon is traced and its reason is clarified by the analysis. Utilizing this method, the behavior of kurtosis is forecasted and analyzed while watching machine condition and correct diagnosis is executed., Journal of economics, business and law. 2005, 7, p.17-27