[Dottorcomp] Seminari di Matematica Applicata. Martedì 21 giugno. Austin Buchanan

[Stefano Lisini]

Seminari di Matematica Applicata, Dipartimento di Matematica "F. Casorati"
e Istituto del CNR IMATI "E. Magenes" di Pavia.

Martedì 21 giugno 2022, alle ore 15.00 precise, presso l'aula Beltrami del
Dipartimento di Matematica,

Austin Buchanan (Oklahoma State University)terrà un seminario dal titolo:

Imposing contiguity constraints in political districting models
Il seminario verrà anche trasmesso in diretta su zoom al link:

https://us02web.zoom.us/j/83344185446?pwd=RHRGai91RkZQTjg0eEVRMWQ5WXFjZz09

Abstract.
Beginning in the 1960s, techniques from operations research began to be
used to generate political districting plans. A classic example is the
integer programming model of Hess et al. (Operations Research 13, 998-1006,
1965). Due to the model’s compactness-seeking objective, it tends to
generate contiguous or nearly contiguous districts, although none of the
model’s constraints explicitly impose contiguity. Consequently, Hess et al.
had to manually adjust their solutions to make them contiguous. Since then,
there have been several attempts to adjust the Hess model and other models
so that contiguity is explicitly ensured. In this talk, we review two
existing models for imposing contiguity, propose two new ones, and
analytically compare them in terms of their strength and size. We conduct
an extensive set of numerical experiments to evaluate their performance.
While many believe that contiguity constraints are particularly difficult
to deal with, we find that the districting problem considered by Hess et
al. does not become harder when contiguity is imposed. In fact, a
branch-and-cut implementation of a cut-based model generates, for the first
time, optimally compact districting plans for 21 different US states at the
census tract level. To encourage future research in this area, and for
purposes of transparency, we make our test instances and source code
publicly available. This is joint work with Hamidreza Validi and Eugene
Lykhovyd.
---------------------

Pagina web dei Seminari di Matematica Applicata
https://matematica.unipv.it/ricerca/cicli-di-seminari/seminari-di-matematica-applicata/
-------------- parte successiva --------------
Un allegato HTML è stato rimosso...
URL: http://ipv01.unipv.it/pipermail/dottorcomp/attachments/20220616/be1be709/attachment.htm