Effect of Reluctant Players in Demographic Prisoner\u27s Dilemma Game

We consider the effect of reluctant player on emergence of cooperation in Demographic Prisoner\u27s Dilemma game. Players are initially randomly distributed in square lattice of cells. In each period, players move to random cell in von Neumann neighbors if unoccupied and play PD game against neighboring player. If wealth (accumulated payoff) of player becomes negative or his age becomes greater than his lifetime, he dies. If his wealth becomes greater than some amount and there is an unoccupied cell in neighbors, he has an offspring. We introduce global move, global play, and reluctant players who use extended forms of Tit for Tat. TFT uses Cooperate (C) at the first period and thereafter immediately replies with the same move to the opponent\u27s. Unlike TFT, a reluctant player may start with Defect (D) at the first period and delay replying with the opponent\u27s move in the last play to an opponent in the current play. Some types of reluctant players are considered by extent of delay. We investigate, by Agent-Based Simulation, the emergence of cooperation where there are reluctant players as well as AllC\u27s and AllD\u27s, and show some cases where cooperation is emerged more frequently with reluctant players than without them.14th Czech-Japan Seminar on Data Analysis and Decision Making under UncertaintyHejnice, Czech RepublicSeptember 18-21, 201

Subparsec-scale dynamics of a dusty gas disk exposed to anisotropic AGN radiation with frequency-dependent radiative transfer

We explore the gas dynamics near the dust sublimation radius of active galactic nucleus (AGN). For the purpose, we perform axisymmetric radiation hydrodynamic simulations of a dusty gas disk of radius $\approx 1\,\mathrm{pc}$ around a supermassive black hole of mass $10^{7}\,\mathrm{M_{\odot}}$ taking into account (1) anisotropic radiation of accretion disk, (2) X-ray heating by corona, (3) radiative transfer of infrared (IR) photons reemitted by dust, (4) frequency dependency of direct and IR radiations, and (5) separate temperatures for gas and dust. As a result, we find that for Eddington ratio $\approx 0.77$, a nearly neutral, dense ($\approx 10^{6\operatorname{-}8}\;\mathrm{cm^{-3}}$), geometrically-thin ($h/r<0.06$) disk forms with a high velocity ($\approx 200 \sim 3000\;\mathrm{km/s}$) dusty outflow launched from the disk surface. The disk temperature is determined by the balance between X-ray heating and various cooling, and the disk is almost supported by thermal pressure. Contrary to \citet{krolik07:_agn}, the radiation pressure by IR photons is not effective to thicken the disk, but rather compresses it. Thus, it seems difficult for a radiation-supported, geometrically-thick, obscuring torus to form near the dust sublimation radius as far as the Eddington ratio is high ($\sim 1$). The mass outflow rate is $0.05$-$0.1\;\mathrm{M_{\odot}}/\mathrm{yr}$ and the column density of the outflow is $N_{\mathrm{H}}\lesssim 10^{21}\;\mathrm{cm^{-2}}$. To explain observed type-II AGN fraction, it is required that outflow gas is extended to larger radii ($r\gtrsim 10\;\mathrm{pc}$) or that a denser dusty wind is launched from smaller radii ($r\sim 10^{4}\;R_{g}$).Comment: 40 pages, 33 figures, 7 tables; accepted for publication in Monthly Notices of the Royal Astronomical Societ

授業を補助するプログラム(2)-協力ゲーム-

論

提携形ゲームのいくつかの解とその縮小ゲームによる一貫性

論

資源利用権の保留負担割当問題

論

A Time Sequential Variable-Threat Nash\u27s Bargaining Problem

論

On the distribution of 1550-nm photon pairs efficiently generated using a periodically poled lithium niobate waveguide

We report on the generation of photon pairs in the 1550-nm band suitable for long-distance fiber-optic quantum key distribution. The photon pairs were generated in a periodically poled lithium niobate waveguide with a high conversion-efficiency. Using a pulsed semiconductor laser with a pulse rate of 800 kHz and a maximum average pump power of 50 muW, we obtained a coincidence rate of 600 s^-1. Our measurements are in agreement with a Poissonian photon-pair distribution, as is expected from a comparison of the coherence time of the pump and of the detected photons. An average of 0.9 photon pairs per pulse was obtained.Comment: 12 pages, 3 figure