This paper describes a life cycle model for performing level-playing field comparisons of the emissions, costs, and energy efficiency trade-offs of alternative fuel vehicles (AFV) through the fuel production chain and over a vehicle lifetime. The model is an improvement over previous models...

Existing probabilistic solutions to the ground-holding problem in air traffic control are of a static nature, with ground-holds assigned to aircraft at the beginning of daily operations. In this paper we present an optimal dynamic solution that simplifies the structure of the control mechanism...