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  • 學位論文

Significance Analysis of Microarrays via Adjusted T Statistics

指導教授 : 許文郁

摘要


In microarray experiments, numerous genes are tested at the same time, and some of them are with low variability. When detecting differentially expressed genes under two biological states, traditional t-test statistics would be very large because of the small denominator. Thus, many of these genes will be mistakenly declared significance via traditional t-test. The adjusted t statistic is to deal with this problem by adding a reasonable constant to the denominator of traditional t-test statistic. This paper suggests a method to select the added constant with data under a mixture model. Expectation-Maximization algorithm is used to estimate MLE of parameters of incomplete data and cope with the mixture components. The criterion of selecting appropriate adjustment is based on the goodness-of -fit test statistic for middle portion data and the postulated model. The simulation results confirm that adjusted t statistics perform better for significance analysis of microarrays.

參考文獻


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