Eddie C. Shek

Semantic multicast: intelligently sharing collaborative sessions

We introduce the concept of semantic multicast to implement a large-scale shared interaction infrastructure providing mechanisms for collecting, indexing, and disseminating the information produced in collaborative sessions. This infrastructure captures the interactions between users (as video, text, audio and other data streams) and promotes a philosophy of filtering, archiving, and correlating collaborative sessions in user and context sensitive groupings. The semantic multicast service efficiently disseminates relevant information to every user engaged in the collaborative session, making the aggregated streams of the collaborative session available to the correct users at the right amount of detail. This contextual focus is accomplished by introducing proxy servers to gather, annotate, and filter the streams appropriate for specific interest groups. Users are subscribed to appropriate proxies, based on their profiles, and the collaborative session becomes a multi-level multicast of data from sources through proxies and to user interest groups.

Sharing experiences from scientific experiments

The ESP2Net project is developing technologies that enable effective collaborative scientific data sharing to support collaboration among scientists, accelerate production of scientific data products, and improve understanding of the science. We have defined a Scientific Experiment Markup Language (SEML) to capture scientific experiments in hypermedia documents as a basic unit of information sharing. A collection of SEML documents can be viewed as an online electronic experiment logbook that captures the entire experiment experience by including the process and interrelationships between experiments to allow an experiment to be re-created. Complementary means of sharing the experiences from scientific experiments (browsing, searching, dissemination, and mining) are provided by integrating OASIS transparent distributed scientific object access, Conquest dynamic distributed query processing services, and active information dissemination services introduced in semantic multicast.

Dynamic multicast information dissemination in hybrid satellite-wireless networks

We have developed Intelligent Information Dissemination Services (IIDS) to support the dissemination and maintenance of extended situation awareness over a hybrid satellite-wireless network information infrastructure. One of the goals of IIDS is to transparently handle the mismatches in characteristics of satellite and terrestrial wireless networks, allow effective utilization of available bandwidth, and support timely delivery of highly relevant information. IIDS achieve the above by implementing user profile aggregation that incrementally aggregates users into communities sharing common interests to enable multicast-based information dissemination. Based on the user grouping, semantic profile matching customizes information streams based on matching user group interest profiles. By taking into account of expected changes in user profiles. profile-oriented data dissemination achieves predictive push and caching that anticipates future user needs and minimizes latency of data request by making data available before they are explicitly requested. The IIDS software has been deployed on the Digital Wireless Battlefield Network that integrates commercial off-theshelf satellite and wireless products.

Semantic agents for content-based discovery in distributed image libraries

The amount, size, and diversity of multimedia information libraries accessible over the Internet and intranets are continuously increasing. This explosion of information demands content-based network information discovery in order to avoid overloading users with irrelevant information during access. Distributed agent systems promise to be a platform to deliver the scalability and extensibility required by dynamic heterogeneous distributed digital libraries. The authors describe the integration of content-based image indexing techniques in a distributed agent system to allow effective and scalable information discovery in large-scale distributed image libraries.

Intelligent information dissemination services in hybrid satellite-wireless networks

The need for rapid deployment and user mobility suggest the use of a hybrid satellite‐wireless network infrastructure for important situation awareness and emergency response applications. An Intelligent Information Dissemination Service (IIDS) has been developed to support the dissemination and maintenance of extended situation awareness throughout such a network information infrastructure in a seamless manner. One of the goals of IIDS is to transparently handle the mismatches in characteristics of satellite and terrestrial wireless networks, allow effective utilization of available bandwidth, and support timely delivery of highly relevant information. IIDS achieves the above by implementing user profile aggregation that incrementally aggregates users into communities sharing common interests to enable multicast‐based information dissemination. Based on the user grouping, semantic profile matching customizes information streams based on matching user group interest profiles. By taking into account expected changes in user profiles, profile‐oriented data dissemination achieves predictive push and caching that anticipates future user needs and minimizes latency of data request by making data available before they are explicitly requested. Finally, bandwidth‐aware filtering adapts information streams to resource bandwidth availability to gracefully hide the bandwidth mismatch between the satellite and wireless links in the hybrid network infrastructure. The IIDS software has been deployed on the Digital Wireless Battlefield Network (DWBN) that integrates commercial off‐the‐shelf satellite and wireless products into a heterogeneous satellite/wireless hybrid network for supporting wireless mobile multimedia services.

Exploiting data lineage for parallel optimization in extensible DBMSs

Extensibility and high query performance are important requirements of advanced large scale information systems since complex data analysis often requires the use of application-specific operations that have to be introduced by the user issuing the query. Towards the goal of supporting automatic parallelization of queries containing complex user-defined evaluators in an extensible DBMS, we devised a relevance window model to capture the inherent data lineage characteristics of evaluators on multidimensional data sets. Informally, the relevance window of an evaluator defines the scope of influence input data records have on the value of records in the output data space. An evaluators relevance window constrains the data partitioning opportunities available for an evaluator.

Dynamic online collaborative information sharing in semantic multicast

Semantic multicast defines a large scale shared interaction infrastructure which provides a seamless environment for collecting, indexing, and disseminating the information produced in collaborative sessions to the correct users in the right amount of detail using IP multicast as the underlying data communication mechanism. A semantic multicast graph is discovered and constructed to organize user requests into a hierarchy of group requests that represents an increasingly specialized range and quality of semantic topics as one goes down the hierarchy. It establishes a logical flow of collaboration stream between interest groups. A semantic multicast graph is mapped onto a hierarchy of cooperating network content agents that gather information streams and incrementally enrich, archive and filter the streams for the semantic coverage of specific interest groups in the graph. Through this mechanism, the semantic multicast framework amortizes processing on information streams by automatically moving common operations on information streams needed to satisfy multiple user requests to content agents providing the services.

Extensible Parallel Query Processing for Exploratory Geoscientific Data Mining

Exploratory data mining and analysis requires a computing environment which provides facilities for the user-friendly expression and rapid execution of “scientific queries.” In this paper, we address research issues in the parallelization of scientific queries containing complex user-defined operations. In a parallel query execution environment, parallelizing a query execution plan involves determining how input data streams to evaluators implementing logical operations can be divided to be processed by clones of the same evaluator in parallel. We introduced the concept of “relevance window” that characterizes data lineage and data partitioning opportunities available for an user-defined evaluator. In addition, we developed a query parallelization framework by extending relational parallel query optimization algorithms to allow the parallelization characteristics of user-defined evaluators to guide the process of query parallelization in an extensible query processing environment. We demonstrated the utility of our system by performing experiments mining cyclonic activity, blocking events, and the upward wave-energy propagation features from several observational and model simulation datasets.

High-speed digital wireless battlefield network

In the past two years, the Digital Wireless Battlefield Network consortium that consists of HRL Laboratories, Hughes Network Systems, Raytheon, and Stanford University has participated in the DARPA TRP program to leverage the efforts in the development of commercial digital wireless products for use in the 21st century battlefield. The consortium has developed an infrastructure and application testbed to support the digitized battlefield. The consortium has implemented and demonstrated this network system. Each member is currently utilizing many of the technology developed in this program in commercial products and offerings. These new communication hardware/software and the demonstrated networking features will benefit military systems and will be applicable to the commercial communication marketplace for high speed voice/data multimedia distribution services.

Information Dissemination Applications

Satellite networks have unique advantage in applications like rapid deployment, situation awareness, and emergency response. The satellite network is often paired with terrestrial wireless networks to form a hybrid satellite-wireless infrastructure to support user mobility [Zhang and Dao, 1996; Dao and Perry, 1996]. However, the mismatches in characteristics of satellite and terrestrial wireless networks must be handled properly to allow effective utilization of available bandwidth, and timely delivery of highly relevant information. We have developed an Intelligent Information Dissemination Services (IIDS) model to address this. We believe it is the right model to support the dissemination and maintenance of extended situation awareness throughout such a network information infrastructure in a seamless manner.