Flow of autonomous traffic on a single multi-lane street

We investigate the behaviour of an original traffic model. The model considers a single multi-lane street, populated by autonomous vehicles directed from either end to the other. Lanes have no intrinsic directionality, and the vehicles are inserted at random at either end and any lane. Collision avoidance is fully automatic and, to enhance the transport capacity of the street, vehicles form_trains_ in which they may travel at high speed quite close to the vehicle in front. We report on the transit times for vehicles under a wide variety of conditions: vehicle insertion probability & imbalance and their maximum speed distribution. We also outline an interesting feature of the model, that the complex interactions of many vehicles are considerably more powerful than a simple "keep left" directive which each vehicle should obey.Comment: Latex, 18 pages, 12 figures. Need to add more reference

A General Framework for Scalability and Performance Analysis of DHT Routing Systems

In recent years, many DHT-based P2P systems have been proposed, analyzed, and certain deployments have reached a global scale with nearly one million nodes. One is thus faced with the question of which particular DHT system to choose, and whether some are inherently more robust and scalable. Toward developing such a comparative framework, we present the reachable component method (RCM) for analyzing the performance of different DHT routing systems subject to random failures. We apply RCM to five DHT systems and obtain analytical expressions that characterize their routability as a continuous function of system size and node failure probability. An important consequence is that in the large-network limit, the routability of certain DHT systems go to zero for any non-zero probability of node failure. These DHT routing algorithms are therefore unscalable, while some others, including Kademlia, which powers the popular eDonkey P2P system, are found to be scalable.Comment: 11 pages, 8 figures; to be published in IEEE DSN 200