Veranstaltungen

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Dienstag, 23.10.2018, 10:15 Uhr (WIAS-406)
Seminar Nichtlineare Optimierung und Inverse Probleme
Dr. D. Tiba, Romanian Academy, Bucharest:
Optimal control methods in shape optimization
mehr ... Veranstaltungsort
Weierstraß-Institut, Mohrenstr. 39, 10117 Berlin, 4. Etage, Weierstraß-Hörsaal (Raum: 406)

Veranstalter
WIAS Berlin
Mittwoch, 24.10.2018, 14:00 Uhr (WIAS-ESH)
Berliner Oberseminar „Nichtlineare partielle Differentialgleichungen” (Langenbach-Seminar)
Prof. Dr. P. Colli, Università di Pavia, Italien:
Shape memory alloys, phase-field models, Cahn--Hilliard systems
mehr ... Veranstaltungsort
Weierstraß-Institut, Mohrenstr. 39, 10117 Berlin, Erdgeschoss, Erhard-Schmidt-Hörsaal

Abstrakt
The title collects some special keywords for research fields in the framework of phase transitions and free boundary problems describing an important research area receiving attention, interest, and a number of significant contributions from Jürgen Sprekels. This talk will offer the speaker the possibility of reviewing some models, problems, and results in the analysis and optimal control of the related systems of partial differential equations. And, more than that, it will be a pleasure for him to recall some thirty years enjoying math by his collaboration with J. Sprekels.

Veranstalter
WIAS Berlin
Mittwoch, 24.10.2018, 15:00 Uhr (WIAS-ESH)
Berliner Oberseminar „Nichtlineare partielle Differentialgleichungen” (Langenbach-Seminar)
Dr. D. Tiba, Romanian Academy, Bucharest:
Implicit parametrizations and applications in optimization and control
mehr ... Veranstaltungsort
Weierstraß-Institut, Mohrenstr. 39, 10117 Berlin, Erdgeschoss, Erhard-Schmidt-Hörsaal

Abstrakt
The talk will discuss necessary conditions (with less Lagrange multipliers), perturbations and general algorithms in non-convex optimization problems. Optimal control problems with mixed constraints, governed by ordinary differential equations, will also be studied in this context. The treatment is based on a recent approach to implicit systems, constructing parametrizations of the corresponding manifold, via iterated Hamiltonian equations.

Veranstalter
WIAS Berlin
Donnerstag, 25.10.2018, 11:30 Uhr (WIAS-406)
Seminar Interacting Random Systems
A. Agazzi, Duke University, USA:
Large deviations and recurrence for chemical reaction networks
mehr ... Veranstaltungsort
Weierstraß-Institut, Mohrenstr. 39, 10117 Berlin, 4. Etage, Weierstraß-Hörsaal (Raum: 406)

Abstrakt
The microscopic dynamics of well-stirred networks of chemical reactions are modeled as jump Markov processes. At large volume, one may expect in this framework to have a straightforward application of large deviation theory. This is not at all true, for the jump rates are typically neither globally Lipschitz, nor bounded away from zero, with both blowup and absorption as quite possible scenarios. In joint work with Amir Dembo and Jean-Pierre Eckmann, we utilize Lyapunov stability theory to bypass this challenges and to characterize a large class of network topologies that satisfy the full Wentzell-Freidlin theory of asymptotic rates of exit from domains of attraction. The extension of such results to the estimation of transitions times between metastable states further requires the positive recurrence of such processes. This property depends critically on dynamics at of the jump Process when the concentration of some of the components are small. Precise statements on the connection between this property and the structure of the underlying network are an active area of research.

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Seminar Interacting Random Systems

Veranstalter
WIAS Berlin