this paper deals with the problem of user-server assignment in online social network systems. online social network applications such as facebook, twitter, or instagram are built on an infrastructure of servers that enables them to communicate with each other. a key factor that determines the facility of communication between the users and the servers is the expected transmission time (ett). a ...

We define the well-known puzzle of Battleships as a decision problem and prove it to be NPcomplete, by means of a parsimonious reduction. By applying Valiant and Vazirani’s (1986) result we immediately obtain that the variant of this problem, viz. promising that there is a unique solution, is NP-complete as well, under randomized reductions. As this finding is in sheer contrast with the general...

Background For the purpose of understanding the Food and Drug Administration’s (FDA’s) concerns regarding online promotion of prescription drugs advertised directly to consumers, this study examines notices of violations (NOVs) and warning letters issued by the FDA to pharmaceutical manufacturers.   Methods The FDA’s warning letters and NOVs, which were issued to pharmaceutical companies over a...