We address the question of how a third-party payer (e.g. an insurer) decides what providers to contract with. Two different mechanisms are studied and their properties compared. A first mechanism consists in the thirdparty payer setting up a bargaining procedure with both providers. The second mechanism is the so-called “any willing provider” where the third-party payer announces a contract and...

In this paper we propose an e-commerce protocol with the following features: (1) ensures true fair exchange, (2) does not require manual dispute resolution in case of unfair behavior by any party, (3) does not require the active involvement of a trusted third party, (4) allows the customer to verify that the product he is about to receive is the one he is paying for, and (5) can be used for the...

Trust is playing an important role in communications and transactions. Based on different reasons of trust, different trusted domains, possibly disjoint, are formed in mobile communications, preventing complete systems from working properly. What is lacked therein is a bridge that can link domains, across trust gaps to establish a complete trusted mobile communication system. In this paper, the...

I start by defining the cosmological parameters H0, Ωm and ΩΛ. Then I show how the age of the universe depends on them, followed by the evolution of the scale parameter of the universe for various values of the density parameters. Then I define strategies for measuring them, and show the results for the recent determination of these parameters from measurements on supernovas of type 1a. Implica...

The optimal decision for an agent to make at a given game situation often depends on the decisions that other agents make at the same time. Rational agents will try to find a stable equilibrium before taking an action. Rational agents can use the negotiation mechanism to reach the equilibrium. In the previous work, we proposed the communication actions of paying guarantee or compensation to con...

A number of real-world search tasks (i.e. police search, detection of improvised explosive devices (IEDs)) require searchers to search exhaustively across open ground. In the present study, we simulated this problem by asking individuals (Experiments 1a and 1b) and dyads (Experiment 2) to search for coin targets pseudo-randomly located in a bounded area of open grassland terrain. In Experiment ...

Electronic cash (E-cash) is the digital counterpart of cash payment. They allow users to spend anonymously unless they “double spend” their electronic coins. However, it is not possible to prevent users from misbehaving under some other subjective definitions of misbehavior, such as money laundering. One solution is to incorporate a trusted third party (TTP), which, upon complaint, uses its pow...

BY THIRD PARTIES (NON-PARENTS) Ronald W. Nelson Rose & Nelson Overland Park, Kansas

In this work we present a flexible tool for tumor progression, which simulates the evolutionary dynamics of cancer. Tumor progression implements a multi-type branching process where the key parameters are the fitness landscape, the mutation rate, and the average time of cell division. The fitness of a cancer cell depends on the mutations it has accumulated. The input to our tool could be any fi...

This article studies the properties of a distributed mechanism to perform the Vickrey auction. This mechanism, which was originally presented in López, Núñez, Rodríguez, and Rubio (2004), has the main characteristic that most of the information concerning the bids is kept private for both bidders and the auctioneer without the necessity of any trusted third party. In particular, after the aucti...