We present a rigorous derivation for off-lattice implementations of the so-called "random-walk" algorithm recently introduced by Wang and Landau [Phys. Rev. Lett. 86, 2050 (2001)]. Originally developed for discrete systems, the algorithm samples configurations according to their inverse density of states using Monte Carlo moves; the estimate for the density of states is refined at each simulati...

Continuous Petri Nets (CPN) can be used to approximate classical discrete Petri nets which suffer from the state explosion problem. In this paper we focus on the control of timed CPN (TCPN), aiming to drive the system from an initial state to a desired final one. This problem is similar to the set-point control problem in a general continuous-state system. In a previous work, a simple and effic...

In the last decade, the world of software development has evolved rapidly. This evolution has led to Component-Based Software Development (CBSD), which in turn has generated tremendous interest in the development of plug-and-play reusable software, leading to the concept of Commercial Off The Shelf (COTS) software components. The use of COTS is increasingly becoming commonplace. This is mainly ...

For the known spectral methods (Galerkin, Tau, Collocation) the condition number behaves like 0(N4) (N: maximal degree of polynomials). We introduce a spectral method with an 0(N2) condition number. The advantages with respect to propagation of rounding errors and preconditioning are demonstrated. A direct solver for constant coefficient problems is given. Extensions to variable coefficient pro...

Field inhomogeneity and susceptibility variations, coupled with a long readout, can result in image blurring in spiral imaging. Many correction methods based on a priori off-resonance information, such as an acquired field map, have been proposed in the literature. Automatic off-resonance correction methods are alternative approaches that estimate a field map from the image data themselves. In ...

We present a domain decomposition approach for the computation of the electromagnetic field within periodic structures. We use a Schwarz method with transparent boundary conditions at the interfaces of the domains. Transparent boundary conditions are approximated by the perfectly matched layer method (PML). To cope with Wood anomalies appearing in periodic structures an adaptive strategy to det...