In this paper we show that, paradoxically, what looks like a “universal improvement” or a “straight-forward improvement” which enables better security and better reliability on a theoretical level, may in fact, within certain operational contexts, introduce new exposures and attacks, resulting in a weaker operational cryptosystem. We demonstrate a number of such dangerous “improvements”. This i...

The recent increase in the notifications of tuberculosis infections has focused the attention of healthcare professionals on reasons for the disease's resurgence. This article describes how directly observed therapy and an enlightened approach to health promotion for groups of people perceived as being at risk, could prevent further increases in incidence.

We discuss the estimation of the asymptotic covariance matrix of semiparametric maximum likelihood estimators by the observed proole information. We show that a discretized version of the second derivative of the proole likelihood function yields consistent estimators of minus the eecient information matrix.

The ability to gather information can affect outcomes in auctions and other games of incomplete information. We investigate situations where agents have a choice about which information, or signals, to observe, and are informed about the signal choices of others. Our models cover common-value games where agents decide whether to coordinate on observed information, and games mixing privateand co...

When agents like mobile robots make observations while carrying out a course of actions, a formalization of the observed information is needed in order to reason about it. When doing so in the situation calculus, a seemingly straightforward approach turns out to be inappropriate since it leads to unintended results and has an unfortunate sensitivity with respect to different forms of successor ...

In the present work, the origin of antiprotons observed in cosmic rays (above the atmosphere) is analyzed in details. We have considered the origin of the primaries, (which their interactions with the interstellar medium is one of the most important sources of antiprotons) is a supernova type II then used a diffusion model for their propagation. We have used the latest parameterization for anti...