1,068 research outputs found

    Modifications of thick-target model: re-acceleration of electron beams by static and stochastic electric fields

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    We study two modifications of the collisional thick-target model (CTTM) based on the global and local re-acceleration of non-thermal electrons by static and stochastic electric fields during their transport from the coronal acceleration site to the thick-target region in the chromosphere. We concentrate on a comparison of the non-thermal electron distribution functions, chromospheric energy deposits, and HXR spectra obtained for both considered modifications with the CTTM itself. The results were obtained using a relativistic test-particle approach. We simulated the transport of non-thermal electrons with a power-law spectrum including the influence of scattering, energy losses, magnetic mirroring, and also the effects of the electric fields corresponding to both modifications of the CTTM. We show that both modifications of the CTTM change the outcome of the chromospheric bombardment in several aspects. The modifications lead to an increase in chromospheric energy deposit, change of its spatial distribution, and a substantial increase in the corresponding HXR spectrum intensity.Comment: 15 pages, 14 figures, 3 tables, to be published in Astronomy and Astrophysic

    Service of Process Abroad—Is There Anything Left of the Hague Service Convention after Volkswagenwerk A.G. v. Schlunk?

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    Can tournaments induce rational play in the centipede game? Exploring dominance vs. strategic uncertainty

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    We compare behavior in a one-shot Centipede game across several payoff structures including nonlinear payoff tournaments. Assuming Nash to be optimal, results suggest nonlinear tournament payoffs based on overall relative rewards are not sufficient to increase Nash results in the one-shot Centipede style setting. Evidence suggests that reducing strategic uncertainty is more important than increasing dominance in promoting Nash play.Centipede game, payoff tournaments, experiment, strategic uncertainty, dominance

    Applications systems verification and transfer project. Volume 4: Operational applications of satellite snow cover observations. Colorado Field Test Center

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    The study was conducted on six watersheds ranging in size from 277 km to 3460 km in the Rio Grande and Arkansas River basins of southwestern Colorado. Six years of satellite data in the period 1973-78 were analyzed and snowcover maps prepared for all available image dates. Seven snowmapping techniques were explored; the photointerpretative method was selected as the most accurate. Three schemes to forecast snowmelt runoff employing satellite snowcover observations were investigated. They included a conceptual hydrologic model, a statistical model, and a graphical method. A reduction of 10% in the current average forecast error is estimated when snowcover data in snowmelt runoff forecasting is shown to be extremely promising. Inability to obtain repetitive coverage due to the 18 day cycle of LANDSAT, the occurrence of cloud cover and slow image delivery are obstacles to the immediate implementation of satellite derived snowcover in operational streamflow forecasting programs

    The Interacting Branching Process as a Simple Model of Innovation

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    We describe innovation in terms of a generalized branching process. Each new invention pairs with any existing one to produce a number of offspring, which is Poisson distributed with mean p. Existing inventions die with probability p/\tau at each generation. In contrast to mean field results, no phase transition occurs; the chance for survival is finite for all p > 0. For \tau = \infty, surviving processes exhibit a bottleneck before exploding super-exponentially - a growth consistent with a law of accelerating returns. This behavior persists for finite \tau. We analyze, in detail, the asymptotic behavior as p \to 0.Comment: 4 pages, 4 figure
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