Stochastically Stable Equilibria in Coordination Games with Multiple Populations

We investigate the equilibrium selection problem in n-person binary coordination games by means of adaptive play with mistakes (Young 1993). The size and the depth of a particular type of basins of attraction are found to be the main factors in determining the selection outcome. The main result shows that if a strategy has the larger basin of attraction, and if it is deep enough, then the strategy constitutes a stochastically stable equilibrium. The existence of games with multiple stochastically stable equilibria is an immediate consequence of the result. We explicitly address the qualitative difference between selection results in multi-dimensional stochastic evolution models and those in single dimensional models, and shed some light on the source of the difference.Equilibrium selection, stochastic stability, unanimity game, coordination game

Multiplicity and Sensitivity of Stochastically Stable Equilibria in Coordination Games

We investigate the equilibrium selection problem in n-person binary coordination games by means of the adaptive play with mistakes (Young 1993). We show that whenever the difference between the deviation losses of respective equilibria is not overwhelming, the stochastic stability exhibits a notable dependence on payoff parameters associated with strategy profiles where the numbers of players for the respective strategies are nearly equal. This feature necessitates the existence of games that possess multiple stochastically stable equilibria.Equilibrium selection, stochastic stability, unanimity game, coordination game

Multiuser Parallel Transmission with 1-tap Time Domain Beamforming by Millimeter Wave Massive Antenna Arrays

This paper investigates the feasibility of multiuser parallel transmission by sub-array beamforming using millimeter wave bands in which the Line-of-Sight (LoS) dominant channel environment is expected. Focusing on high beamforming gain provided by the massive antenna array, each sub-array conducts first eigenmode transmission and thus one stream is allocated per user without null steering. This paper also proposes 1-tap time domain beamforming (TDBF) as the same weight is applied to all frequency components. It reduces computation complexity as well as suppressing the effect of additive noise on weight derivation. Computer simulation results show that increasing the subarray spacing stably improves signal-to-interference power ratio (SIR) performance and that the proposed 1-tap TDBF can match the performance of the frequency domain first eigenmode transmission as a rigorous solution

Multiple Stochastically Stable Equilibria in Coordination Games

In an (n,m)-coordination game, each of the n players has two alternative strategies. A strategy generates positive payoff only if there are at least m-1 others who choose the same, where m>n/2. The payoff is nondecreasing in the number of such others so that there are exactly two strict equilibria. Applying the adaptive play with mistakes (Young 1993) to (n,m)-coordination games, we point out potential complications inherent in many-person games. Focusing on games that admit simple analysis, we show that there is a nonempty open set of (n,m)-coordination games that possess multiple stochastically stable equilibria, which may be Pareto ranked, if and only if m>(n+3)/2, which in turn is equivalent to the condition that there is a strategy profile against which every player has alternative best responses.Equilibrium selection, stochastic stability, unanimity game, coordination game, collective decision making

Accretion of Solid Materials onto Circumplanetary Disks from Protoplanetary Disks

We investigate accretion of solid materials onto circumplanetary disks from heliocentric orbits rotating in protoplanetary disks, which is a key process for the formation of regular satellite systems. In the late stage of gas-capturing phase of giant planet formation, the accreting gas from protoplanetary disks forms circumplanetary disks. Since the accretion flow toward the circumplanetary disks affects the particle motion through gas drag force, we use hydrodynamic simulation data for the gas drag term to calculate the motion of solid materials. We consider wide range of size for the solid particles ($10^{-2}$-$10^6$m), and find that the accretion efficiency of the solid particles peaks around 10m-sized particles because energy dissipation of drag with circum-planetary disk gas in this size regime is most effective. The efficiency for particles larger than 10m size becomes lower because gas drag becomes less effective. For particles smaller than 10m, the efficiency is lower because the particles are strongly coupled with the back-ground gas flow, which prevent particles from accretion. We also find that the distance from the planet where the particles are captured by the circumplanetary disks is in a narrow range and well described as a function of the particle size.Comment: 12 pages, 11 figures, accepted for publication in Ap

Construction of Optimal Linear Codes by Geometric Puncturing

Dedicated to the memory of S.M. Dodunekov (1945–2012)Abstract. Geometric puncturing is a method to construct new codes. ACM Computing Classification System (1998): E.4.∗This research was partially supported by Grant-in-Aid for Scientific Research of Japan Society for the Promotion of Science under Contract Number 24540138

Seraglio

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Investment in the Development of Latvian Music Pedagogy by Latvians Living beyond Latvia

History of music pedagogy is developed by great personalities. Wherever Latvia’s musicians have been brought by their life routes – music has been above any difficulties encountered. The artist’s education has to be represented in two directions – historical and systematic. Without a clear insight into one’s own national history of art, no one can grow into a real artist. Explorations in history of music pedagogy can more objectively assess the present and prognosticate perspectives in the future. The more we learn about the Latvian by descent artists’ creative activities, their working methods and results beyond Latvia, the greater is our desire to use their experiences in our own work, as the child development is always in the centre of researches. One of collaboration ways is the’’ International Latvian Young Musicians Camp’’ headed by the director – professor, Dr.paed. Ingrīda Gutberga, a Latvian living abroad, well-known as an organist, conductor, pianist, chair person of Boston Latvian Heritage foundation. The participants of the camp are young musicians from all over the world enjoying guidance of internationally renowned music pedagogues