In an expected reachability-time game (ERTG) two players, Min and Max, move a token along the transitions of a probabilistic timed automaton, so as to minimise and maximise, respectively, the expected time to reach a target. These games are concurrent since at each step of the game both players choose a timed move (a time delay and action under their control), and the transition of the game is ...

We study the fully-dynamic all pairs shortest path problem for graphs with arbitrary non-negative edge weights. It is known for digraphs that an update of the distance matrix costs Õ(n) worst-case time [Thorup, STOC ’05] and Õ(n) amortized time [Demetrescu and Italiano, J.ACM ’04] where n is the number of vertices. We present the first average-case analysis of the undirected problem. For a rand...

Data replication places physical copies of a shared logical item onto different sites. Optimistic replication (OR) allows a program at some site to read or update the local replica at any time. An update is tentative because it may conflict with a remote update. Such conflicts are resolved after the fact, in the background. Replicas may diverge occasionally but are expected to converge eventual...

We give optimal algorithms for generating discrete random variables for changing distributions. We discuss two models of how distributions may change. In both models, we obtain a solution with constant update time, constant expected generate time, and linear space.

In formalizing a ‘veil of ignorance’ type procedure, this paper considers how an agent’s preferences over a set of alternatives change as he is placed at an increasing ‘distance’ from the consequences of his choices. A definition for such ‘removed preferences’ is presented and its properties studied. As an application, it is demonstrated that decreasingly impatient agents are ‘essentially’ expo...

For a wireless network to effectively deliver services to the mobile users, it must have an efficient way to track them. The location management fulfills this task through location registration and paging. Many location management strategies, such as profile-based scheme (PBS), have been proposed to reduce the signaling traffic caused by the location update and paging. In the PBS scheme, the sy...

We develop a randomized kinetic data structure that maintains a partition of the moving points into two sets such that the corresponding cut is with probability at least 1−% a (1− )-approximation of the Euclidean MaxCut. The data structure answers queries of the form “to which side of the partition belongs query point p?” in O(2 O(1) log n/ ) time. Under linear motion the data structure process...

Currently, the influenza vaccine is updated only when there is at least a 4-fold difference [measured by the hemagglutination inhibition (HI) assay] between the current vaccine strain and an expected epidemic strain. It is not clear if this is the optimal strategy, especially for individuals vaccinated every year. Using a computer model, we determined the vaccine efficacy resulting from 12 diff...

The paper presents the specification, development and initial performance evaluation of the Simplicity Device (SD), which is one of the key components of the SIMPLICITY Architecture. The SD is both a portable personalization device and a hardware Single-Sign-On (SSO) token. It accommodates the Simplicity User Profile (SUP), which contains user context related information and has been designed a...