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seminars:stat:180503 [2018/05/06 08:24]
qyu created
seminars:stat:180503 [2018/05/06 08:47] (current)
qyu
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 +<WRAP centeralign>##​Statistics Seminar##\\ Department of Mathematical Sciences</​WRAP>​
 +
 +<WRAP 70% center>
 +^  **DATE:​**|Thursday,​ May 3, 2018 |
 +^  **TIME:​**|1:​00pm -- 2:15pm |
 +^  **LOCATION:​**|WH 100E |
 +^  **SPEAKER:​**|Junyi Dong, Binghamton ​ University |
 +^  **TITLE:​**|Marginal Distribution Method ​ |
 +</​WRAP>​
 +\\ 
 +
 +<WRAP center box 80%>
 +<WRAP centeralign>​**Abstract**</​WRAP>​
 +Let Z be the covariate vector and Y
 +be the response variable with the joint cumulative distribution function
 +F.  Given a random sample from F,
 +in order to analyze the data based on a certain
 + ​proportional hazards (PH) model,
 +one needs to test the null hypothesis Ho:
 +F belongs to the Ph model first.
 +The existing tests to achieve this task make use of the residuals and
 +are invalid in  certain situations, such as
 +when
 + $F$ is not
 +from any PH model. To overcome this disadvantage,​
 +we propose a valid model checking test of Ho.
 +It is based on the weighted average of the  difference between
 +two estimators of the marginal distribution
 +of the response variable: its non-parametric maximum likelihood
 +estimator
 +and its estimator under the PH model.
 +This test is called the marginal distribution (MD) test.
 +We give the theoretical justification of the MD test.
 +The simulation study suggests that
 + the MD test is always consistent,
 + ​whereas
 +the existing tests  may be invalid and they are often  unlikely ​ to reject the wrong PH model assumption
 + when they are not valid.
 +
 +</​WRAP>​
 +
 +
 +
 +