Managing Temporal Knowledge in Port Management Systems

Large ports need to deal with a number of disparate activities:the movement of ships, containers and other cargo, theloading and unloading of ships and containers, customs activities.As well as human resources, anchorages, channels, lighters,tugs, berths, warehouse and other storage spaces have to beallocated and released. The efficient management of a port involvesmanaging these activities and resources, managing theflows of money involved between the agents providing and usingthese resources, and providing management information.Many information systems will be involved.Many applications have to deal with a large amount of datawhich not only represent the perceived state of the real world atpresent, but also past and/or future states. These applicationsare not served adequately by today's computer managementand database systems. In particular, deletions and updates insuch systems have destructive semantics. This means that previousdatabase contents (representing previous perceived statesof the real world) cannot be accessed anymore.A review of how define temporal data models, based ongeneralizing a non-temporal data model in to a temporal one toimprove port management is presented. This paper describes apractical experiment which supports managing temporal dataalong with the corresponding prototype implementations.