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@PHDTHESIS{Ziegler:210495,
author = {Ziegler, Ute},
othercontributors = {Herty, Michael},
title = {{M}athematical modelling, simulation and optimisation of
dynamic transportation networks : with applications in
production and traffic},
address = {Aachen},
publisher = {Publikationsserver der RWTH Aachen University},
reportid = {RWTH-CONV-143622},
pages = {IV, 172 S. : graph. Darst.},
year = {2012},
note = {Prüfungsjahr: 2012. - Publikationsjahr: 2013; Aachen,
Techn. Hochsch., Diss., 2012},
abstract = {In this work we provide a general classification of dynamic
transportation networks (DTNs), which represent macroscopic
PDE/ODE-based descriptions of network flow problems. There
is a broad variety of versions depending on the application;
for example it is possible to model buffers, where particles
can be stored. Furthermore, we can describe the evolution of
density by conservation laws and model different kinds of
coupling conditions. Afterwards we consider optimisation
techniques. We discuss the advantages of mixed integer
optimisation and presented a general strategy how DTNs can
be transformed into linear mixed-integer optimization
Problems (short MIPs). Furthermore, we show how the
knowledge of the problem structure can be used to introduce
bounding heuristics which are extremely efficient to speed
up the optimisation procedure. Within this frame, we present
specific models with application in production and traffic.
The first is a novel production model for the time-changing
repair worker assignment. The main idea is to keep the
system performance optimal whenever machines have failed and
must be repaired. In general, available workers are limited
and therefore a decision has to be made on which machines
are repaired first. The resulting optimisation question is
how the optimal worker schedule looks like to maximise the
production flow. This issue is intensively analysed and
numerical case studies comparing fixed and time-changing
schedules are presented. The numerical results show the
different opportunities of our modelling approach. With
respect to the second application, we consider the LWR-based
traffic flow network model. We show how coupling conditions
of several junction types can be transformed into easily
linearisable min-terms. We introduce a numerical framework
for the Hamilton-Jacobi formulation of traffic flow and show
how this correctly resolves the dynamics at the junction. We
present simulations for a roundabout and compare them with
existing results and computed travel times for certain
routes through the network depending on the starting time of
the travel. Moreover, we model traffic light settings for
LWR-based traffic flow networks that can easily be adapted
to arbitrary junction types and network topologies and
discuss requirements for secure traffic light settings. We
show the necessity of additional requirements on the
switching time rate to avoid inapplicably frequent
fluctuations which appear when mixed integer optimisation
techniques are used, and solve this problem with previously
derived techniques. Furthermore, we use the knowledge of the
problem structure to develop bounding heuristics to speed up
the optimisation process by providing feasible solutions for
the subproblems within the $Branch\&Bound$ procedure. The
resulting improvements for the optimisation procedure are
remarkable and indicate the potential of combining
simulation techniques with Branch $\&$ Bound procedures.},
keywords = {Gemischt-ganzzahlige Optimierung (SWD) / Netzwerk (SWD) /
Dynamik (SWD) / Mathematische Modellierung (SWD) / Heuristik
(SWD)},
cin = {110000 / 114620},
ddc = {510},
cid = {$I:(DE-82)110000_20140620$ / $I:(DE-82)114620_20140620$},
shelfmark = {35R02 * 90B20 * 90B30 * 35Q93 * 90C57},
typ = {PUB:(DE-HGF)11},
urn = {urn:nbn:de:hbz:82-opus-44522},
url = {https://publications.rwth-aachen.de/record/210495},
}