We study the pinning dynamics of magnetic flux (vortex) lines in a disordered type-II superconductor. Using numerical simulations of a directed elastic line model, we extract the pinning time distributions of vortex line segments. We compare different model implementations for the disorder in the surrounding medium: discrete, localized pinning potential wells that are either attractive and repu...

PhFit, a new Phase-type fitting tool is presented in this paper. PhFit allows for approximating distributions or set of samples not only by continuous but by discrete Phasetype distributions as well. The implemented algorithms separate the fitting of the body and the tail part of the distribution which results in satisfactory fitting also for heavy-tail distributions. Moreover, PhFit allows the...

This paper deals with chain graphs under the classic Lauritzen-Wermuth-Frydenberg interpretation. We prove that almost all the regular Gaussian distributions that factorize with respect to a chain graph are faithful to it. This result has three important consequences. First, chain graphs are more powerful than undirected graphs and acyclic directed graphs for representing regular Gaussian distr...

We provide the first necessary and sufficient conditions in the literature for the existence of maximal elements in a non-binary choice framework. As an application, the characterization of the existence of maximal elements for acyclic binary relations obtained in Rodŕıguez-Palmero and Garćıa-Lapresta, 2002, Mathematical Social Sciences 43, 55-60, is deduced as a Corollary. Further characteriza...

For propositional formulas we present a new transformation into satisfiability equivalent 3-CNF formulas of linear length. The main idea is to represent formulas as parallel-serial graphs. This is a subclass of directed acyclic multigraphs where the edges are labeled with literals and the AND operation (respectively, the OR operation) is expressed as parallel (respectively, serial) connection.

Wild, M., Cover preserving embedding of modular lattices into partition lattices, Discrete Mathematics 112 (1993) 207-244. When is a finite modular lattice couer preserving embeddable into a partition lattice? We give some necessary, and slightly sharper sufficient conditions. For example, the class of cover preserving embeddable modular lattices strictly contains the class of acyclic modular l...

In this paper the two identical unit cold standby systems with single repairman has been discussed.The concept of inspection policy has also been introduced for detecting the kind of failures (major or minor) before the failed unit get repaired by some repair mechanism.The model has been design for the system to calculate the various important measures of reliability i.e MTSF, steady state avai...

Estimation of L norms of Fourier multipliers is known to be hard. It is usually connected to some interesting types of PDE, see several such PDE for several Fourier multipliers on the line in a recent paper of Kalton and Verbitsky [13]. Sometimes, but much more rarely, one can establish sharp L estimates for Fourier multipliers in several variables. Riesz transforms are examples of success. The...

We apply a simple linearization, well known in solid state physics, to approximate the evolution at early times of cosmological N-body simulations of gravity. In the limit that the initial perturbations, applied to an infinite perfect lattice, are at wavelengths much greater than the lattice spacing l, the evolution is exactly that of a pressureless self-gravitating fluid treated in the analogo...

We survey some of the central results in the complexity theory of discrete neural networks, with pointers to the literature. Our main emphasis is on the computational power of various acyclic and cyclic network models, but we also discuss brieey the complexity aspects of synthesizing networks from examples of their behavior.