Using synthetic data we study the possibility of determining 1-D velocity models of the upper crust from P- and S-wave arrival times in the case of a narrow depth interval of seismic sources and sparse distribution of stations. The test is tailored to a similar real situation in one subregion of the western part of the Corinth Gulf, Greece. Two kinds of models are studied: (i) models composed of layers with constant velocity gradients, and (ii) models composed of homogeneous layers. To derive the structural models from arrival times, the Neighbourhood Algorithm of Sambridge (1999) is used, combined with the grid search for source locations. Weighted P- and S-wave arrival time residuals are used as the misfit function. Accurate and perturbed synthetic arrival times are used. The velocities at medium depths, with a fast velocity increase, are well determined in both models for the accurate data. However, the determination of velocity is less certain in the uppermost 5 km for the gradient model, and in the deepest layer for the model composed of homogeneous layers for the perturbed data. The presence or absence of hypocentres in the uppermost or in the second layer influences notably the obtained velocity in these layers in both models., Jaromír Janský, Vladimír Plicka and Oldřich Novotný., and Obsahuje bibliografii
In this paper, we study the problem of finding deterministic (also known as feedback or closed-loop) Markov Nash equilibria for a class of discrete-time stochastic games. In order to establish our results, we develop a potential game approach based on the dynamic programming technique. The identified potential stochastic games have Borel state and action spaces and possibly unbounded nondifferentiable cost-per-stage functions. In particular, the team (or coordination) stochastic games and the stochastic games with an action independent transition law are covered.
Vysvětlíme tři hlavní významy slova chaos: v běžné řeči, v řecké mytologii a v teorii dynamických systémů. Dále se soustředíme na deterministický chaos jako typ chování nelineárních dynamických systémů. Uvedeme definice a vysvětlíme základní pojmy a budeme diskutovat vlastnosti a důsledky chaotických řešení. Uvedeme kvantitativní kritérium pro odlišení náhodných a deterministických systémů. Na závěr zmíníme souvislosti mezi deterministickým chaosem a výtvarným uměním., Pavel Pokorný., and Obsahuje seznam literatury
Many physiological and pathological processes in the cardiac tissue have been shown to be associated with a release of endothelin (ET) peptides and with induction of specific ET-receptors and G-protein-coupled ion channels. However, the exact mechanism regulating ET-receptors in the myocardium is controversial. The response to ET-1, the most important member of the ET family, is rapidly attenuated by down-regulation of ET-receptors. The internalization of ET-1 bound to two subclasses of specific receptors (ETA and ETB) that are abundant in the myocardium has been hypothesized to activate and/or inhibit a variety of intracellular signal transducing systems. The [125I]ET-1, BQ-3020 and selective ET-antagonists were used to study the subtype-selective component of regulation of ET-1 receptors in myocardial membranes. We determined the characteristics of [125I]ET-1 binding and [3H]thymidine incorporation in whole cell saturation studies and measured Ca 2+ channel induction and the total number of inactive Ca2+ channels in photoaffinity studies with [3H]azidopine. Here we demonstrate four important components of the complex ET-1 response in human, porcine and rat myocardium, leading to aberrant responses of cells. After ET-1 induction, adaptive subtype-ETB selective down-regulation predominated in human embryonic fibroblasts, in porcine membrane vesicles and in microsomal membranes of renal hypertensive rats, with preferential high affinity ET-1 binding to ETA receptors and with the resultant ETA mediated proliferative and mitogenic activation of human fibroblasts. The ET-1 induction was also accompanied by profound inactivation of Ca2+ channels in myocardial membranes., J. Dřímal, M. Mislovičová, A. Ismail, F. Monček., and Obsahuje bibliografii
This presented work is concerned with a friction element impact and detuning mass impact of the bending oscillation of a couple of blades with a friction element embodied between the blade shrouds. Either of the blades is discretized by FEM using beam elements and continuously distributed weight is concentraed in nodal points. One of the blades is excited by harmonic varying force. The friction element, which is considered as a rigid body, is pulled using constant tension force into a wedge gap between the blade shrouds. The detuning of this system is caused by an additional mass mounting on one of the blade shrouds. Numerical simulation results are compared with results of the equivalent linearization method. The effects of the friction and detuning on the blades vibration suppression are analyzed. and Obsahuje seznam literatury