[Forum SIS] Seminar of Prof. Zamar (UBC)

[Claudio Agostinelli]

Dipartimento di Scienze Ambientali, Informatica e Statistica
Universita' Ca' Foscari
Venezia

Announce of Seminar

Prof. Ruben Zamar
Department of Statistics
University of British Columbia

Ensembling Classification Models Based on Phalanxes of Variables with
Applications in Drug Discovery

21 March 2013 at 10.30am
Aula ex Consiglio di Statistica
Palazzo Ala C2
San Giobbe, Venezia

Anyone interested is invited to participate

Abstract:
Statistical detection of rare cases in highly unbalanced two class
situations is an interesting and challenging problem. We are interested
in detecting rare chemical compounds that are active against a
biological target, such as lung cancer tumor cells, as part of a drug
discovery process. Instead of predicting the classes of the compounds,
we rank all of the compounds in terms of their probability of activity
to produce a shortlist containing the maximum number of actives. We have
used four assay data sets and five rich - in terms of number of
variables – descriptor sets for each of the four assays. Capitalizing on
the richness of variables in a descriptor set, we form the phalanxes by
grouping variables together. The variables in a phalanx are good to put
together, whereas the variables in different phalanxes are good to
ensemble. We then form our ensemble by growing a random forest in each
phalanx and aggregating them over the phalanxes. The performance of the
ensemble of phalanxes is found to be better than its competitors random
forest and regularized random forest. Our ensemble performs very well
when there are many variables in a descriptor set and when the
proportion of active compounds is very small. In other words, the harder
the problem is the better the ensemble of phalanxes performs relative to
alternative procedures.

"Nota automatica aggiunta dal sistema  di posta
Il 5 per mille per sostenere i giovani ricercatori di Ca' Foscari.
E' un atto volontario, non costa nulla e non sostituisce l'8 per mille.
Scegli Ca' Foscari: codice fiscale 80007720271
Please note that the above message is addressed only to individuals filing
Italian income tax returns. -- "
-------------- next part --------------
A non-text attachment was scrubbed...
Name: claudio.vcf
Type: text/x-vcard
Size: 701 bytes
Desc: not available
URL: <http://www.stat.unipg.it/pipermail/sis/attachments/20130318/c331d455/attachment.vcf>