A prototype semiorder database used for activity recognition in multi-sensory monitoring environments is described. Activities are spatio-temporal compositions of events, which are a type of atomic semantic units for such compositions. The focus is on the temporal composition of activities from events in the presence of bounded duration of temporal uncertainty in an event occurrence. Such temporal uncertainty forces the concurrency between event occurrences to be intransitive. Under certain assumptions, a subclass of partial orders, known as semiorders, models such intransitive concurrency appropriately. The semiorder database stores events and their semiorder temporal order of occurrences. A semiorder data model and the corresponding query language that embeds a semiorder pattern language are the main constituents of the semiorder database. We demonstrate this database and queries for activity recognition in a real time environment. The demonstration also includes a transducer subsystem for detection of events.

A collection of distributed databases forms an important architectural component of the ATON project for networked incidence management of highway traffic. The database sub-architecture supports the architectural integration of many thematic areas of the ATON, and provides many high level abstractions that semantically correspond to traffic incidents. These databases are queried for the detection of local or distributed traffic incidents by many distributed control and analysis algorithms. The abstract database sub-architecture leads to many databases of different types having different functions. The semantic event/activity database is one of them. The distributed multi-sensory sub-architecture detects atomic semantic events that occur in the environment. The event/activity database stores them and their temporal structures. An activity is a temporal composition of atomic events. A specialized query language is used to flexibly define and detect activities of interest. The query language embodies high level semantic pattern matching abstractions. Preliminary results of using the event/activity database are also presented.

We propose a distributed security architecture for incorporation into object oriented distributed computing systems, and in particular, into OMG's CORBA based object architectures. The primary objective of the security architecture is to make CORBA resilient to both component failures and malicious attacks. The core of the architecture is the notion of secure ORB node-an ORB node enhanced with "pluggable" system security objects interacting through generic security service APIs. System security objects coupled with protocols among them facilitate creation and management of clients, objects, and security information. Security services addressed in the paper include, but are in no way limited to, client/object authentication, access control, and integrity and confidentiality protections.>

An open architecture that achieves seamless binding between networking and multimedia devices is proposed. The building blocks of the binding architecture consist of a set of interfaces, methods and primitives. The former abstract the functionalities of multimedia networking devices and are realized as objects organized into a binding interface base. The methods and primitives are invoked for implementing binding applications. The binding architecture is embedded into a reference model for multimedia networking architectures that supports a clean separation between binding interfaces and binding algorithms. Communication between the objects realizing the binding interfaces is supported by CORBA. Public interfaces in the binding interface base are specified using CORBA IDL. The architecture is illustrated with a simple connection management algorithm and an example of computational binding.