ACE ORB Research Articles

An ontology-based semantic service for cooperative urban equipments

The development of SOA (service oriented architecture) applications is a paradigm to consider for the integration of services which usually requires the incorporation of distributed artificial intelligence technologies or multi agent systems (MAS) to achieve their objectives. This is the case of transportation field, where the improvement of urban data networks and embedded systems allow the implementation of complex distributed services based on intelligent transportation systems. One of the challenges of this kind of systems is the discovery of services. Typically, discovery of services lacks of intelligence, or the result of this process returns a lot of nonsense information. However, the field of transportation requires quick and accurate requests and answers to deal with emergencies or incidents in the traffic flow. For this purpose, this paper proposes the development of a specific service called semantic service (an ontology-based semantic communication service) developed in TAO (The ACE ORB) of CORBA (common object request broker architecture). This service is able to provide a communication support for distributed environment in conjunction with a set of base libraries like Redland (RDF language bindings) for interacting with ontologies written in RDF and RDFS format. A parser Raptor (RDF Syntax Library) is used for analyzing sequences of symbols to determine the grammatical structure, and a syntax query language, Rasqal (RDF Query Library) is used to build and execute queries. Both, Raptor and Rasqal were designed to work with the Redland library. The main objective is to manage ontological information and interoperate with implemented services in embedded urban devices. Obtained results demonstrate the feasibility and effectiveness of the proposed approach.

Using principle patterns to optimize real-time ORBs

Increasing quality-of-service requirements pose challenges in both design and optimization for real time CORBA middleware. The authors describe TAO (The Ace ORB), an object request broker that provides end-to-end QoS guarantees. In discussing TAO, we focus on object-adapter and ORB-core optimizations in three key dimensions in high performance, real time ORB end system design: server-side concurrency, memory management, and CORBA request demultiplexing.