Prof.
Hartmann Alexander
(University of Oldenburg)
25/05/2012, 09:00
We study the vertex-cover problem on Erdös-Reny random
graphs, where previously a phase transition at connectivity
c=e coinciding with an easy-hard transition of a branch-
and-bound algorithm in connection with the leave-removal
heuristic has been found. Hence, this algorithm works by
partially exploring the space of feasible configurations. In
this work, we consider an algorithm...
Dr
Alexander Mozeika
(Aalto University)
25/05/2012, 09:45
Equilibrium is a fundamental concept in statistical physics; it
assumes that while the system dynamics is governed by
microscopic interactions, some systems eventually reach a
state where macroscopic observables remain unchanged.
The evolution of many such systems is driven by the
corresponding Hamiltonian energy function and their states
converge to the equilibrium Gibbs-Boltzmann...
Prof.
Maria Magdolna Ercsey Ravasz
(Babes-Bolyai University)
25/05/2012, 10:45
The analog dynamical system we recently designed to
solve constraint satisfaction (Nature Physics 7, 966,
2011) opens potential new avenues to handle hard
optimization problems. As an example I will present our
Sudoku solver and show how it helps us define a type
of "Richter scale" to characterize the hardness of
Sudoku problems. These analog solvers are based on
the...
Dr
Eugen Czeizler
(Aalto University)
25/05/2012, 11:30
We consider the problem of finding, for a given 2D
pattern of coloured tiles, a minimal set of tiles
assembling this pattern (in the abstract Tile Assembly
Model of Winfree (1998)). This Patterned self-Assembly
Tile set Synthesis (PATS) problem was first introduced by
Ma and Lombardi (2008), and subsequently studied by
Goos and Orponen (2010), who presented an
exhaustive...
Prof.
Martin Weigt
(Université Pierre et Marie Curie)
25/05/2012, 14:00
Many families of homologous proteins show a remarkable
degree of structural and functional conservation, despite
their large variability in amino acid sequences. We have
developed a statistical-mechanics inspired inference
approach to link this variability (easy to observe) to
structure (hard to obtain), i.e. to infer directly co-evolving
residue pairs which turn our to form native...
Prof.
Matteo Marsili
(Abdus Salam ICTP)
25/05/2012, 15:15
I will present a general framework which can be used to
reconstruct probability distributions for strings of binary
variables. While the problem of inference can be analytically
controlled for small systems, a description of some of the
regularization prescriptions needed to treat large systems
will be provided, together with a discussion concerning their
symmetries. Finally,...
Dr
Mikko Vehkaperä
(KTH and Aalto University)
25/05/2012, 16:00
The sparse representation problem of recovering an N
dimensional sparse vector x from M < N linear observations
y = Dx given dictionary D is considered. The standard
approach is to let the elements of the dictionary be
independent and identically distributed (IID) zero-mean
Gaussian and minimize the l1 norm of x under the
constraint y = Dx. In this talk, we discuss the replica...
