Institute of Mathematics and Statistics,
University of Kent at Canterbury,
Statistics Seminar -- Lent Term 1999
Thursday, 4th March 1999
2:00pm Professor David Siegmund
(Stanford Univesrity and
Isaac Newton Institute -Cambridge)
"Searching for Signals against a Noisy Background"
ABSTRACT
Problems in medical imaging, astrophysics, gene mapping, and sequence
alignment involve observations of a random field $Z_u$ for $u \in U$,
where $U$ is a subset of $r$ dimensional Euclidean space (often $r =1,2,$
or 3). Over most of the space $U$, $Z_u$ is random noise; but in a
relatively small part of the space it may contain a signal that one wants
to detect and locate as precisely as possible. A natural formulation
leads to a class of irregular statistical problems, where standard large
sample maximum likelihood theory and the asymptotic equivalence of
maximum likelihood and Bayesian procedures may not hold. In this talk I
will describe the scientific background of some of these problems and
show that their common features make it possible to develop a unified
theoretical approach for signal detection and localization. In
particular, I
will describe approximations for the p-value of the likelihood ratio test
for signal detection, which involves the maximum of a random field. An
important distinction is between processes where $Z_u$ has smooth sample
paths and process where it does not. While probabilistic methods
play an important role in both cases, geometric methods can be
particularly useful in the first case.
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Further details of the seminar programme and abstracts of
forthcoming talks are available from:
http://www.ukc.ac.uk/IMS/statistics/people/T.Sapatinas/Seminars/
seminars.html
All are very welcome. The Statistics Seminars will be held in
Mathematics Lecture Theatre in the Institute of Mathematics and
Statistics, Cornwallis Building.
The following WWW page contain details of how to get to the campus,
and how to find your way around:
http://www.ukc.ac.uk/ukc/location.html
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Dr Theofanis Sapatinas,
Lecturer in Statistics,
Postal Address: Institute of Mathematics and Statistics,
University of Kent at Canterbury,
Canterbury, Kent CT2 7NF,
United Kingdom.
Tel: ++(44)-1227-827253
Fax: ++(44)-1227-827932
E-mail: [log in to unmask]
Web: http://www.ukc.ac.uk/IMS/statistics/people/T.Sapatinas/
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