210 research outputs found

    Fissioned Triangular Schemes via the Cross-ratio

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    AbstractA construction of association schemes is presented; these are fission schemes of the triangular schemesT (n) where n=q+ 1 with q any prime power. The key observation is quite elementary, being that the natural action of PGL(2, q) on the 2-element subsets of the projective line PG(1, q) is generously transitive. In addition, some observations on the intersection parameters and fusion schemes of these association schemes are made

    Fissioned Triangular Schemes Via the Cross-Ratio

    Get PDF
    A construction of association schemes is presented; these are fission schemes of the triangular schemes T(n) where n=q + 1with q any prime power. The key observation is quite elementary, being that the natural action of PGL(2,q) on the 2-element subsets of the projective line PG(1,q) is generously transitive. Also some observations on the intersection parameters and fusion schemes of these association schemes are made.

    On 3-Hypergraphs with Forbidden 4-Vertex Configurations

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    “All citizens of the world can save a life” — The World Restart a Heart (WRAH) initiative starts in 2018

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    “All citizens of the world can save a life”. With these words, the International Liaison Committee on Resuscitation (ILCOR) is launching the first global initiative – World Restart a Heart (WRAH) – to increase public awareness and therefore the rates of bystander cardiopulmonary resuscitation (CPR) for victims of cardiac arrest. In most of the cases, it takes too long for the emergency services to arrive on scene after the victim's collapse. Thus, the most effective way to increase survival and favourable outcome in cardiac arrest by two- to fourfold is early CPR by lay bystanders and by “first responders”. Lay bystander resuscitation rates, however, differ significantly across the world, ranging from 5 to 80%. If all countries could have high lay bystander resuscitation rates, this would help to save hundreds of thousands of lives every year. In order to achieve this goal, all seven ILCOR councils have agreed to participate in WRAH 2018. Besides schoolchildren education in CPR (“KIDS SAVE LIVES”), many other initiatives have already been developed in different parts of the world. ILCOR is keen for the WRAH initiative to be as inclusive as possible, and that it should happen every year on 16 October or as close to that day as possible. Besides recommending CPR training for children and adults, it is hoped that a unified global message will enable our policy makers to take action to address the inequalities in patient survival around the world.Revisión por pare

    Metal-insulator transition in a doubly orbitally degenerate model with correlated hopping

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    In the present paper we propose a doubly orbitally degenerate narrow-band model with correlated hopping. The peculiarity of the model is taking into account the matrix element of electron-electron interaction which describes intersite hoppings of electrons. In particular, this leads to the concentration dependence of the effective hopping integral. The cases of the strong and weak Hund's coupling are considered. By means of a generalized mean-field approximation the single-particle Green function and quasiparticle energy spectrum are calculated. Metal-insulator transition is studied in the model at different integer values of the electron concentration. With the help of the obtained energy spectrum we find energy gap width and criteria of metal-insulator transition.Comment: minor revisions, published in Phys. Rev.
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