Thursday, September 23, 2010

[DMANET] Job Announcement: Ph.D. position - University of Antwerp

*** PhD position on multi-level vehicle routing problems ***
Application deadline: 1 December 2010

At the University of Antwerp (Belgium), there is a vacant position for a
pre-doctoral researcher in operations research (vehicle routing) at the
Faculty of Applied Economics. The ideal candidate has a good background in
operations research ( and mathematics, including
good programming skills and a good command of the English language.

The position is meant to conduct research on multi-level vehicle routing
problems. The work, which involves the implementation and testing of
heuristic optimization strategies, will be carried out in close
collaboration with Kenneth Sörensen and Peter Goos. The candidate is
expected to enroll the university's Ph.D. program and to obtain a Ph.D. at
the end of the project. A short project description can be found below. We
offer a four-year position (with annual evaluation), a net monthly grant of
about 1900 euro, and a stimulating working environment in a lively
cosmopolitan city.

For more information, please contact Kenneth Sörensen at Applications should be sent by email, and should
include [1] a detailed CV including description of background in operations
research as well as programming skills, [2] complete transcripts of
bachelor and master degrees, [3] a motivation letter and [4] (if available)
results on TOEFL/GMAT/GRE tests.

The deadline for application is 1 December 2010. Preferably, the candidate
should start working on 1 January 2011.

Short project description

The main aim of this project is to develop efficient solution methods for
several reallife multi-level vehicle routing problems. In multi-level
vehicle routing problems, decisions are taken on different levels. For
* In multi-depot vehicle routing problems, decisions need to be taken on
which customer to service from which depot, besides the typical routing
decisions (determining the sequence of the customers in the routes and the
assignment of customers to vehicles).
* In school bus routing problems, decisions to be taken include the
assignment of students to bus stops, the selection of bus stops to use, as
well as the typical routing decisions.
* In location-routing problems, the algorithm decides the optimal location
of distribution facilities, as well as the typical routing decisions.

A second research topic of this project is the search for the most
appropriate type of solution method for multi-level routing problems:
iterative or integrated. We will examine specifically whether integrated
optimization yields better results than sequential or iterative
optimization, and what the main influencing factors are for the differences
in performance.

A third important research topic that we intend to study is the interaction
between different neighborhoods that operate on different levels of a
multi-level problem. This will lead to a better understanding of the
working of these neighborhoods and their interaction, and make the design
of more powerful metaheuristics possible.

Finally, as a fourth research topic we intend to study the integration of
exact methods into the developed heuristics. More and more, the study of
so-called matheuristics, heuristics integrating mathematical programming
methods, are being viewed as an interesting research avenue. Progress in
the development of general integer programming solvers (such ILOG's Cplex)
during the last decade has been impressive, and has become such that using
these solvers for real-life (sub)problems has become an attractive option.
In fact, multi-level problems offer an interesting playground for this type
of methods, as some of the sub-problems can potentially be solved using
exact methods, whereas others
can be solved using neighborhood search heuristics.

For a more extensive description of the project, contact
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