Dear scheduling researcher,
We are delighted to announce the talk given by Maurice Queyranne (Sauder
School, UBC).
The title is "On Polyhedral Approaches to Scheduling Problems".
The seminar will take place on Zoom on Wednesday, June 22 at 13:00 UTC.
Join Zoom Meeting
https://cesnet.zoom.us/j/91083429684?pwd=QlJXcHB4dGtLdE40b1hGaEVMbTNFdz09
Meeting ID: 910 8342 9684
Passcode: 190280
You can follow the seminar online or offline on our Youtube channel as well:
https://www.youtube.com/channel/UCUoCNnaAfw5NAntItILFn4A
The abstract follows.
The formulation of scheduling problems as mathematical optimization
problems is a useful step in deriving exact solutions, or approximate
solutions with performance guarantees. We give a brief overview of
polyhedral approaches, which aim to apply the power of linear and
mixed-integer optimization to certain classes of scheduling problems, in
particular those with min-sum type of objectives such as to minimize
weighted sums of completion dates. The choice of decision variables is
the prime determinant of such formulations. Constraints, such as facet
inducing inequalities for corresponding polyhedra, are often needed, in
addition to those just required for the validity of the initial
formulation, in order to derive useful dual bounds and structural
insights. Alternative formulations are based on various types of
decision variables, such as: start date and completion date variables,
that simply specify when a task is performed; linear ordering variables,
that prescribe the relative order of pairs of tasks; traveling salesman
variables, which capture immediate succession of tasks and changeovers;
assignment and positional date variables, which specify the assignment
of tasks to machine or to positions; and time-indexed variables which
rely on a discretization of the planning horizon, in particular machine
switch-on and switch-off variables in production planning and unit
commitment in power generation. We point out relationship between
various models, and emphasize the role of supermodular polyhedra and
greedy algorithms.
The next talk in our series will be in September.
For more details, please visit https://schedulingseminar.com/
With kind regards
Zdenek, Mike and Guohua
--
Zdenek Hanzalek
Industrial Informatics Department,
Czech Institute of Informatics, Robotics and Cybernetics,
Czech Technical University in Prague,
Jugoslavskych partyzanu 1580/3, 160 00 Prague 6, Czech Republic
https://rtime.ciirc.cvut.cz/~hanzalek/
Dear scheduling researcher,
We are delighted to announce the talk given by Nicole Megow (Universität
Bremen).
The title is "Learning-Augmented Online Algorithms for Scheduling and
Routing".
The seminar will take place on Zoom on Wednesday, June 8 at 13:00 UTC.
Join Zoom Meeting
https://cesnet.zoom.us/j/93281103550?pwd=ckU0dWRRYWFUb2tRV2duakRjMVgyZz09
Meeting ID: 932 8110 3550
Passcode: 197150
You can follow the seminar online or offline on our Youtube channel as well:
https://www.youtube.com/channel/UCUoCNnaAfw5NAntItILFn4A
The abstract follows.
Online optimization refers to solving problems where an initially
unknown input is revealed incrementally, and irrevocable decisions must
be made not knowing future requests. The assumption of not having any
prior knowledge about future requests seems overly pessimistic. Given
the success of machine-learning methods and data-driven applications,
one may expect to have access to predictions about future requests.
However, simply trusting them might lead to very poor solutions, as
these predictions come with no quality guarantee. In this talk we
present recent developments in the young line of research that
integrates such error-prone predictions into algorithm design to break
through worst case barriers. We discuss different prediction models and
algorithmic challenges with a focus on online scheduling and routing and
give an outlook to network design problems.
The next talk in our series will be given by:
Maurice Queyranne (Sauder School, UBC)| June 22 | On Polyhedral
Approaches to Scheduling Problems
For more details, please visit https://schedulingseminar.com/
With kind regards
Zdenek, Mike and Guohua
--
Zdenek Hanzalek
Industrial Informatics Department,
Czech Institute of Informatics, Robotics and Cybernetics,
Czech Technical University in Prague,
Jugoslavskych partyzanu 1580/3, 160 00 Prague 6, Czech Republic
https://rtime.ciirc.cvut.cz/~hanzalek/