Abstract: An infinite graph may have the property that two independent random walks on the graph  never meet each other, although each of them visits every vertex of the graph infinitely often.

Abstract: Adaptive MCMC algorithms are designed to tune the chain properly to decrease the time to convergence to stationary.

Abstract: Propp and Wilson showed how to generate a Markov chain which in a finite number of steps gives a sample from the stationary distribution supported by a countable set.

Abstract: Different logic-based knowledge representation formalisms have different limitations either with respect to expressivity or with respect to computational efficiency.

We discuss algorithms for the private analysis of network data. Such algorithms work on data sets that contain sensitive relationship information (for example, romantic ties).