1,625 research outputs found

    Toward Legalization of Poker: The Skill vs. Chance Debate

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    This paper sheds light on the age-old argument as to whether poker is a game in which skill predominates over chance or vice versa. Recent work addressing the issue of skill vs. chance is reviewed. This current study considers two different scenarios to address the issue: 1) a mathematical analysis supported by computer simulations of one random player and one skilled player in Texas Hold\u27Em, and 2) full-table simulation games of Texas Hold\u27Em and Seven Card Stud. Findings for scenario 1 showed the skilled player winning 97 percent of the hands. Findings for scenario 2 further reinforced that highly skilled players convincingly beat unskilled players. Following this study that shows poker as predominantly a skill game, various gaming jurisdictions might declare poker as such, thus legalizing and broadening the game for new venues, new markets, new demographics, and new media. Internet gaming in particular could be expanded and released from its current illegality in the U.S. with benefits accruing to casinos who wish to offer online poker

    Range of orbital angular momenta available for complete fusion between heavy ions

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    The same compound nucleus, 158Er, has been formed through three different entrance channels, with projectiles 16O, 40Ar and 84Kr. Excitation functions for reactions (HI, 5n) and (HI, 6n) are well fitted by statistical model calculations, provided that a certain window in orbital angular momentum should be taken in order to produce complete fusion in the case of Ar ions and Kr ions. Curiously enough, low l-waves should be avoided. It implies that, during the interaction leading to complete fusion, the energy dissipation by tangential friction should be rather large

    A Lagrangian dynamic subgrid-scale model turbulence

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    A new formulation of the dynamic subgrid-scale model is tested in which the error associated with the Germano identity is minimized over flow pathlines rather than over directions of statistical homogeneity. This procedure allows the application of the dynamic model with averaging to flows in complex geometries that do not possess homogeneous directions. The characteristic Lagrangian time scale over which the averaging is performed is chosen such that the model is purely dissipative, guaranteeing numerical stability when coupled with the Smagorinsky model. The formulation is tested successfully in forced and decaying isotropic turbulence and in fully developed and transitional channel flow. In homogeneous flows, the results are similar to those of the volume-averaged dynamic model, while in channel flow, the predictions are superior to those of the plane-averaged dynamic model. The relationship between the averaged terms in the model and vortical structures (worms) that appear in the LES is investigated. Computational overhead is kept small (about 10 percent above the CPU requirements of the volume or plane-averaged dynamic model) by using an approximate scheme to advance the Lagrangian tracking through first-order Euler time integration and linear interpolation in space

    X-rays Trace the Volatile Content of Interstellar Objects

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    The non-detection of a coma surrounding 1I/`Oumuamua, the first discovered interstellar object (ISO), has prompted a variety of hypotheses to explain its nongravitational acceleration. Given that forthcoming surveys are poised to identify analogues of this enigmatic object, it is prudent to devise alternative approaches to characterization. In this study, we posit X-ray spectroscopy as a surprisingly effective probe of volatile ISO compositions. Heavily ionized metals in the solar wind interact with outgassed neutrals and emit high-energy photons in a process known as charge exchange, and charge exchange induced X-rays from comets and planetary bodies have been observed extensively in our Solar System. We develop a model to predict the X-ray flux of an ISO based on its chemical inventory and ephemeris. We find that while standard cometary constituents, such as H2_2O, CO2_2, CO, and dust are best probed via optical or infrared observations, we predict strong X-ray emission generated by charge exchange with extended comae of H2_2 and N2_2 -- species which lack strong infrared fluorescence transitions. We find that XMM-Newton would have been sensitive to charge exchange emission from 1I/`Oumuamua during the object's close approach to Earth, and that constraints on composition may have been feasible. We argue for follow-up X-ray observations of newly discovered ISOs with close-in perihelia. Compositional constraints on the general ISO population could reconcile the apparently self-conflicting nature of 1I/`Oumuamua, and provide insight into the earliest stages of planet formation in extrasolar systems.Comment: Accepted to The Astrophysical Journal. 18 pages, 6 figure
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