Master of Science (MS)
First Committee Member
Ashok K. Singh
Number of Pages
Environmental engineers and scientists often encounter trace level concentrations of contaminants that fall below the detection limit (DL) are reported as 'less than DL'. The common method of dealing with non-detects in a multivariate sample is the substitution method in which each observation 'less than DL' is replaced by a suitable value (0, DL/2 or DL) with DL/2 being the recommended method; In this thesis, the applicability of Kaplan-Meier method, which was developed for estimating the survival function in the presence of right censored data, is investigated. Some simulated examples are presented.
Covariance; Detects; Estimation; Matrix; Presence
University of Nevada, Las Vegas
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Saravanan, Shanmugapriya, "Estimation of the covariance matrix in presence of non-detects" (2005). UNLV Retrospective Theses & Dissertations. 1906.