A vehicle space where vehicles move around is structured in a space tree whose nodes are space objects. Higher-level objects denote broader area than lower level ones. Each vehicle first decides a broad path which includes higher-level objects, and the path is made more detailed as the vehicle is approaching to the destination. Vehicles are modeled as transactions which hold objects. There are kinds of vehicles, on three points, removable, stoppable, and retreatable. In this paper, we discuss three schemes, i.e. close, semiopen, and open ones for locking and releasing objects with respect to types of vehicles.
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- 1.Deen, S. M., Hamada, S., and Takizawa, M., “Broad Path Decision in Vehicle System,” Proc. of the 3rd International Conf. on Database and Expert Systems Applications (DEXA'92), 1992, pp.8–13.Google Scholar
- 2.Eswaren, K. P., Gray, J., Lorie, R. A., and Traiger, I. L., “The Notion of Consistency and Predicate Locks in Database Systems,” CACM, Vol. 19, No.11, 1976, pp. 624–637.Google Scholar
- 3.Moss, J. E., “Nested Transactions: An Approach to Reliable Distributed Computing,” The MIT Press Series in Information Systems, 1985.Google Scholar
- 4.Takizawa, M. and Deen, S. M., “Lock Mode Based Resolution of Uncompensatable Deadlock,” Proc. of the Far-east Workshop on Future Database Systems, 1992, pp.168–175.Google Scholar