The non-gaussianity of processes observed in financial markets and relatively good performance of gaussian models can be reconciled by replacing the Brownian motion with Lévy processes whose Lévy densities decay as exp(−λ|x|) or faster, where λ > 0 is large. This leads to asymptotic pricing models. The leading term, P0, is the price in the Gaussian model with the same instantaneous drift and va...

Solitons, defined as nonlinear waves which can reflect from boundaries or transmit through each other, are found in conservative, fully integrable systems. Similar phenomena, dubbed quasi-solitons, have been observed also in dissipative, "excitable" systems, either at finely tuned parameters (near a bifurcation) or in systems with cross-diffusion. Here we demonstrate that quasi-solitons can be ...

We report the empirical discovery of an exceptionally high cross-B electron transport rate in magnetized plasmas, in which transverse currents are driven with abruptly applied high power. Experiments in three different magnetic geometries are analyzed, covering several orders of magnitude in plasma density, magnetic field strength, and ion mass. It is demonstrated that a suitable normalization ...

We study the problems involved in the recursive de nition of (quasi) orders on terms, focussing on the question of establishing well-de nedness, and the properties required for partial and quasi-orders: irre exivity and transitivity, and re exivity and transitivity, respectively. These properties are in general di cult to establish and this has in many cases come down in the literature as folkl...

in the present work, the extraction of zinc from a sphalerite concentrate using sodium nitrate as an oxidant in a sulfuric acid solution was investigated. the effective parameters such as the temperature, sulfuric acid and sodium nitrite concentrations, stirring speed, particle size, and solid/liquid (s/l) ratio were analyzed. the dissolution rate increased with increase in the sulfuric acid an...

background and aims. cad/cam systems facilitate the use of zirconia substructure materials for all-ceramic copings. this in vitro study investigated the marginal and internal fit of zirconia copings made with cad/cam system and slip-casting method. materials and methods. sixteen cad/cam made zirconia copings and 16 slip-cast made zirconia copings were fabricated and cemented with glass-ionomer ...