background the increase in high-risk injections and unsafe sexual behaviors has led to increased hiv infection prevalence among intravenous drug users (idus). the high costs of hiv/aids care and low financial resources necessitate an economic evaluation to make the best decision for the control of hiv/aids. objectives this study was conducted to determine the cost-effectiveness of methadone mai...

some servers are to be located at nodes of a network. demand for services of these servers is located at each node and a subset of the nodes is to be chosen to locate one server in each. each customer selects a server with a probability dependent on distance and a certain amount of benefit is achieved after giving service to the customer. customers may waive receiving service with a known proba...