Transaction model of vehicle movement

This paper discusses how to nd a path in a space for a vehicle to move to the destination. The space is composed of space objects structured in a hierarchical tree named a space tree. Higher-level objects denote broader area than lower-level ones in the space tree. Vehicles rst nds broader paths which include higher-level objects in the space tree, and then the path is made more detailed as the vehicles are approaching to the destinations. A movement of each vehicle v on an object o is atomic, i.e. v can either pass o or not. Vehicles are modeled as transactions which hold objects in the space tree. There are kinds of vehicles with respect to how to move on the space. For example, cars can stop but airplane cannot, packets can be removed but trains cannot, and cars can back but cannot in the motorway. In this paper, we discuss three schemes, i.e. close, semi-open, and open ones on when the vehicles release the objects, and discuss how the schemes can be adopted to the vehicle types and the evaluation of the schemes. Keyword: Distributed system, Broad scheduling, Transaction.