On Friday there will be an invited talk and several tutorials, demos and helpdesk sessions for polymake users.
Participants are encouraged to use a laptop with an installed version of polymake in the tutorials. If you have any polymake problem you want to get help during the workshop please describe your problem during the sign up process.
The workshop will take place in the E-N building of TU Berlin in the rooms 058 and 057. See here for a pin.
Please fill out the registration form!
| Friday | |||
|---|---|---|---|
| 09:00-09:30 | Registration | ||
| 09:30-10:30 | Talk: Polyhedral Computations using Linear Optimization Oracles | ||
| Marc Pfetsch | |||
| 10:30-11:00 | Break and Helpdesk | ||
| 11:00-12:00 | Tut: polymake Basics E-N 058 | Tut: TBA E-N 057 | |
| Paul Mücksch & Igor | Marcel Wack | ||
| 12:00-14:00 | Lunch and Coffee | ||
| 14:00-15:00 | Tut: application tropical | Tut: TBA | |
| Lena Weis | TBA | ||
| 15:00-15:30 | Break and Helpdesk | ||
| 15:30-16:30 | Use cases | ||
| Secondary fans | |||
| Kamillo Ferry | |||
| Algebraic shifting | |||
| Fabian Lenzen | |||
| 16:30-18:15 | Helpdesk | ||
| ~18:45 | Dinner (self paid, at Café Hardenberg) | ||
This talk will cover two topics in which polyhedral computations are based on an indirect access to the underlying polyhedron via an oracle that can solve linear optimization problems. In both cases, the oracle is given by the (computationally expensive) solution of a mixed-integer linear optimization problem.
The first topic deals with the computation of so-called local cuts. These are inequalities that can be added during a branch-and-cut algorithm to solve mixed-integer linear problems. The idea is to generate these inequalities by using small (local) subproblems for which the oracle is reasonably fast in practice. The inequalities can be constructed using a so-called Frank-Wolfe algorithm, which computes a projection onto the polyhedron.
The second topic is about sensitivity analysis of mixed-integer linear optimization problems. We would like to compute the normal cone at a particular vertex. Since the polyhedron is not directly accessible, an algorithm that iteratively builds the cone is designed. In each main iteration the cone is possibly extended by a ray that is computed using the oracle and a beneath-and-beyond step is performed.
The developer meeting takes place on Thursday and Saturday surrounding the conference. If you want to participate in the developer meeting as well, please let us know by email. Developers can find more information here.
Please contact us with any questions about the workshop. To email us, please use LASTNAME@math.tu-berlin.de.