Showing papers by "Shyan-Ming Yuan published in 1999"

A new architecture for integration of CORBA and OODB

Abstract: Object oriented database system (OODB) supports an object oriented data model with the functionality of persistency and transaction semantics. In order to facilitate the use of OODB, the Object Database Management Group (ODMG) defined a standard for object database management systems. On the other hand, the Object Management Group (OMG) defined the Common Object Request Broker Architecture (CORBA), which is an emerging standard of distributed object technology providing the interconnection network between distributed objects. For the sake of matching these two object models, taking the advantages of merging both of them, and building a more sophisticated infrastructure, the integration of CORBA and OODB is currently an urgent and important issue in distributed object systems. Instead of using Object Database Adapter (ODA) suggested by the ODMG, we provide a novel way of reusing the Object Transaction Service (OTS) and wrapping techniques to introduce OODB into CORBA automatically. Through our design, CORBA clients or OODB object implementers do not need to learn any knowledge of each other. In addition, error recovery is also provided to guarantee the consistency of object states. The whole task for integrating CORBA and OODB is done transparently by our proposed preprocessor, which plays an important role in solving problems encountered by ORB and OODB vendors easily.

An agent-based search engine based on the Internet search service on the CORBA

Abstract: Search services are important tools in the World Wide Web. In general, these standard Web search engines are far from ideal. Many researchers have therefore implemented the multi-engine search service (MESS) using meta-broker. However these MESS prove difficult when integrating a new search engine. On the other hand, applications that need the search service ability also prove difficult using these MESS. In this paper we propose an Internet search service (ISS) based on CORBA. We follow the style of Common Object Service Specification to define the interface of ISS, so that it is not only easily to integrate any search engine into multi-search services, but can also be queried by application programs. In addition, two search engine agents are implemented in our project, one is for Yahoo and the other is for AltaVista. Programmers can use this interface to code their search engine agent or to query the search service in their applications. Finally, we build a heterogeneous search engine agent based on this architecture.

Federated query service based on CORBA

Abstract: The current information technology trend is toward the distribution of data among numbers of autonomous and heterogeneous repositories. Object Query Service is specified by OMG to provide uniform interfaces for users to retrieve information based on predicate based query, despite data heterogeneity. We propose a sophisticated architecture for querying federated information for the CORBA paradigm based on the Object Query Service framework. The dissimilarity between our system and other implementations of Query Service, which focus on query processing and system performance is that we concentrate on the requirements, behaviors, scalability as well as the extensibility of the federated query system from different participants' points of view. We design a prototype called "Octopus" to demonstrate the feasibility of our architecture. We also share the experiences learned while designing the federated query service.