In this paper, we study the vaccination of graphs against the outbreak of infectious diseases, in the following natural model generalizing a model by Aspnes et al.: An infectious disease breaks out at a random node of the graph and propagates along the edges of the graph. Vaccinated nodes cannot be infected, nor pass on the infection, whereas all other nodes do. The decisions on which nodes get vaccinated must be made before the random outbreak location is known. There is a cost associated with vaccination and a different cost with getting infected.

In this paper, we study the price of anarchy of traffic routing, under the assumption that users are partially altruistic or spiteful. We model such behavior by positing that the "cost" perceived by a user is a linear combination of the actual latency of the route chosen (selfish component), and the increase in latency the user causes for others (altruistic component). We show that if all users have a coefficient of at least β > 0 for the altruistic component, then the price of anarchy is bounded by 1/β, for all network topologies, arbitrary commodities, and arbitrary semi-convex latency functions. We extend this result to give more precise bounds on the price of anarchy for specific classes of latency functions, even for β < 0 modeling spiteful behavior. In particular, we show that if all latency functions are linear, the price of anarchy is bounded by 4/(3+2β--β2).

Rake receiving is a crucial technique in spread spectrum system. Typical rake receivers, implemented all-digitally, entail considerable power consumption. Though generally regarded as a promising low power solution, analog rake receivers have not been widely adopted because of formidable design complexity in integrating the overall analog and digital systems. In this paper, we present a practical scheme to realize a digitally-controlled mixed-signal rake receiver with both software and hardware simulation results demonstrating the efficiency of the proposed system. Synthesis and SPICE simulations using 0.18/spl mu/m CMOS technology show that the power consumption is less than 2.5 mW while operating at 16 MHz clock rate at 1.5 V supply voltage.

As wireless communication services become more prevalent, bandwidth requirement increases dramatically. As such, the concept of cognitive radio (CR) has recently received much attention. In this paper, we present a MIMO-OFDM based CR system capable of dynamically adjusting its system parameters according to spectrum allocation. From system simulation, the proposed transceiver is shown to be a promising solution for CR applications.