切割點之估計

Cutoff point estimation

侯智飛(Zhi-Fei Hou)

指導教授 ： 陳鄰安

國立交通大學/理學院/統計學研究所/碩士(2009年)

https://doi.org/10.6842/NCTU.2009.00142

摘要

切割點在建構使用基因影響表現分析的離群和或離群平均上扮演重要角色。我們在這篇論文中考慮了切割點的估計，其中樣本切割點估計量的近似分配，我們討論一種是根據經驗分位數來推導的，另一個是根據Chen和Chiang(1996)發展的對稱分位數來推導的。在檢測離群值的近似變異數和檢定力顯示由對稱分位數估計的樣本切割點跟經驗分位數比較起來是非常有競爭力的。

關鍵字

切割點 ； 經驗分位數 ； 檢定力比較 ； 對稱分位數

並列摘要

Cutoff point plays a vital role in constructing outlier sum or outlier mean which is used for gene influential expression analysis. We consider the estimation of the cutoff point in this paper. Asymptotic distributions of sample cutoff point estimates, one based on empirical quantiles and one based on symmetric quantiles of Chen and Chiang(1996), are developed. Comparisons of asymptotic variance and power for detecting outliers are performed showing that the version of sample cutoff point based on symmetric quantiles is very competitive with the one based on the empirical quantile.

並列關鍵字

cutoff points ； empirical quantile ； power comparison ； symmetric quantile

參考文獻

Agrawal, D., Chen, T., Irby, R., et al. (2002). Osteopontin identified as lead marker of colon cancer progression, using pooled sample expression profiling. J. Natl. Cancr Inst. 94, 513-521

Alizadeh, A. A., Eisen, M. B., Davis, R. E., et al. (2000). Distinct types of diffuse large Be-cell lymphoma identified by gene expression profiling. Nature, 403, 503-511

Chen, L.-A. and Chiang, Y.C. (1996). Symmetric type quantile and trimmed means for location and linear

regression model. Journal of Nonparametric Statistics.7,171-185

Chen, L.-A. Chen, D.-T. and Chan, W. (2008). P value for outlier sum in differential gene expression analysis. Submitted to Biometrika for publication (In revision).