Szemináriumok

Kari Nyílt Nap

Időpont: 
2018. 11. 16.
09:00 to 16:00
Hely: 
BME K épület

Sok szeretettel várunk minden kedves érdeklődőt a Budapesti Műszaki és Gazdaságtudományi Egyetem Természettudományi Karának Nyílt Napjára 2018. november 16-án (pénteken) a BME dísztermében.

Részletes információk: http://felvi.physics.bme.hu/nyiltnap

Operator semigroups, innovative integrators, and flood prevention

Időpont: 
2018. 11. 15. 10:15
Hely: 
H306
Előadó: 
Csomós Petra

The talk summarizes our results obtained when studying the possible application of innovative integrators (operator splitting  procedures and exponential integrators) to optimal control problems. We introduce the innovative integrators considered, and present the advantages and drawbacks of their use. After introducing the abstract optimal control problem having a linear quadratic cost function, we prove the convergence of innovative integrators applied to it. To do so, we briefly summarize the main results in operator semigroup theory, used in the proof. As an example, we treat the linear quadratic regulator problem of the one-dimensional and two-dimensional shallow water equations, and illustrate our results by numerical experiments.

The results are based on the joint works with Johannes Winckler (Tübingen) and Hermann Mena (Innsbruck).

Moving average network examples for asymptotically stable periodic orbits of monotone maps

Időpont: 
2018. 11. 08. 10:15
Hely: 
H306
Előadó: 
Garay Barna

For a certain type of discrete--time nonlinear consensus dynamics, asymptotically stable periodic orbits are constructed. Based on a simple ordinal pattern assumption, the Frucht graph, two Petersen septets, hypercubes, a technical class of circulant graphs (containing Paley graphs of prime order), and complete graphs are considered -- they are all carrying moving average monotone dynamics admitting asymptotically stable periodic orbits with period 2. Carried by a directed graph with 594 (multiple and multiple loop) edges on 3 vertices, also the existence of asymptotically stable r-periodic orbits, r=3,4,... is shown.

Ergodicity in nonautonomous linear ordinary differential equations

Időpont: 
2018. 10. 25. 10:15
Hely: 
H306
Előadó: 
Pituk Mihály (Matematika Tanszék, Pannon Egyetem, Veszprém)

The weak and strong ergodic properties of the positive solutions of nonautonomous linear ordinary differential equations will be considered. We will show that if the coefficient matrix function is bounded, essentially nonnegative and uniformly irreducible, then the normalized positive solutions are asymptotically equivalent to the Perron vectors of the strongly positive transition matrix at infinity (weak ergodicity). If, in addition, the coefficient matrix function is uniformly continuous, then the convergence of the normalized positive solutions to the same strongly positive limiting vector (strong ergodicity) is equivalent to the convergence of the Perron vectors of the coefficient matrices. 

This is a joint work with Professor Christian Pötzsche (Alpen-Adria University Klagenfurt, Austria).

Oldalak