Positive value of information in games

We exhibit a general class of interactive decision situations in which all the agents benefit from more information. This class includes as a special case the classical comparison of statistical experiments à la Blackwell. AMS 2000 Subject Classification:Primary 91A35.The work of Bruno Bassan and Marco Scarsini was partially supported by MIUR-COFIN. The authors express their thanks to Sylvain Sorin for enlightening comments.     

Coordination through De Bruijn sequences

Let (x_t) be an n-periodic sequence in which the first n elements are drawn i.i.d. according to some rational distribution. We prove there exists a constant C such that whenever mlnm?Cn, with probability close to 1, there exists an automaton of size m that matches the sequence at almost all stages.     

The Folk Theorem for finitely repeated games with mixed strategies

This paper proves a Folk Theorem for finitely repeated games with mixed strategies. To obtain this result, we first show a similar property for finitely repeated games with terminal payoffs.     

Repeated communication through the mechanism and

We consider the “and” communication device that receives inputs from two players and outputs the public signal yes if both messages are yes, and outputs no otherwise. We prove that no correlation can securely be implemented using this device, even when infinitely many stages of communication are allowed. Received December 1998/Final version November 2000     

The anodic oxidation of gold + palladium alloys

The anodic oxidation of Au+Pd alloys has been studied in solutions of 1 M H₂SO₄ and 0.1 M K₂SO₄ by voltammetric methods. A linear relationship between oxide reduction maximum and bulk alloy composition, often used to determine the surface composition of homogeneous alloys, could be shown to hold only for alloys up to 60 at% gold. At higher gold content the Au oxide peak must be additionally evaluated. With continuous cycling in acid solution the anodic dissolution of Pd, especially from gold-rich places, leads to a rather heterogeneous surface. The O--chemisorption is not governed by a transfer mechanism from Pd to Au surface atoms. The alloys are able to absorb the oxygen species generated in the positive potential region; however, this ability decreases with increase of the gold content.     

Informationally optimal correlation

This papers studies an optimization problem under entropy constraints arising from repeated games with signals. We provide general properties of solutions and a full characterization of optimal solutions for 2 × 2 sets of actions. As an application we compute the minmax values of some repeated games with signals.     

Investigations on the adsorption and electrocatalytic oxidation of carbon monoxide on gold + palladium alloys

A bifunctional mechanism of electrocatalysis was found for the CO-oxidation at Au + Pd alloys. The synergetic effect works best at the 20% Au alloy. The different behaviour of An + Pd and Ag + Pd alloys was assigned to the formation of CO-induced ensembles of Pd-atoms at Au + Pd alloys with high gold content, which is possible due to a high mobility of Pd-atoms at the surface. As CO could be shown to react preferably with the Au-oxide species, the course of the energy of activation for the gas phase reaction might be understood on the-basis of geometric effects.     

Alloy formation at the deposition of palladium on gold at room temperature

Palladium is shown to be deposited underpotentially on gold electrodes in 1 M H₂OSO₄. The deposit forms an alloy according to a t^1/2 law. The rate of alloy formation is strongly dependent on the potential. The diffusion coefficient is about 10^?16 cm² s^?1. This value is discussed in comparison with earlier measurements on gold-palladium alloys at higher temperatures.