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Activity Number:
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6
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Type:
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Invited
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Date/Time:
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Sunday, July 29, 2007 : 2:00 PM to 3:50 PM
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Sponsor:
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Section on Nonparametric Statistics
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| Abstract - #307844 |
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Title:
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Asymptotically Optimal Tests Under Loss of Identifiability in Semiparametric Models
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Author(s):
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Rui Song and Michael Kosorok*+ and Jason Fine
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Companies:
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The University of North Carolina at Chapel Hill and The University of North Carolina at Chapel Hill and University of Wisconsin-Madison
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Address:
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Department of Biostatistics , Chapel Hill , NC, 27599-7420,
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Keywords:
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Semiparametric methods ; Optimal tests ; Loss of identifiability ; Change-point models ; Transformation models ; Mixture models
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Abstract:
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We consider tests of hypotheses when the parameters are not identifiable under the null in semiparametric models. Under a weighted average power criterion, exponential average tests are characterized and shown to be asymptotically optimal. The results can be applied to a variety of semiparametric models, for example, tests of presence of change-point in transformation models, tests of regression parameters in gamma frailty models, and tests of the number of mixture components in finite components mixture models are discussed. We also propose a modified weighted bootstrap for computing the critical values of the test statistic.
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