This paper describes an approach to ontology negotiation between agents supporting intelligent information management. Ontologies are declarative (data-driven) expressions of an agent's “world”: the objects, operations, facts and rules that constitute the logical space within which an agent performs. Ontology negotiation enables agents to cooperate in performing a task, even if they are based on different ontologies.Our objective is to increase the opportunities for “strange agents” – that is, agents not necessarily developed within the same framework or with the same contextual operating assumptions – to communicate in solving tasks when they encounter each other on the web. In particular, we have focused on information search tasks.We have developed a protocol that allows agents to discover ontology conflicts and then, through incremental interpretation, clarification and explanation, establish a common basis for communicating with each other. We have implemented this protocol in a set of Java classes that can be added to a variety of agents, irrespective of their underlying ontological assumptions. We have demonstrated the use of the protocol, through this implementation, in a test-bed that includes two large scientific archives: NASA's Global Change Master Directory and NOAA's Wind and Sea Index.This paper presents an overview of different methods for resolving ontology mismatches and motivates the Ontology Negotiation Protocol (ONP) as a method that addresses some problems with other approaches. Much remains to be done. The protocol must be tested in larger and less familiar contexts (for example, numerous archives that have not been preselected) and it must be extended to accommodate additional forms of clarification and ontology evolution.

Ontology negotiation between intelligent information agents

The efficient query and extraction of web data is often difficult, because web data does not conform to any data organization standard. In addition, the development of web search technology is still at a relatively early stage. Search engines provide only primitive data query capabilities, and require a detailed syntactic specification to retrieve relevant data. Furthermore, web data exists in a myriad of formats including PDF documents, images, and sound clips that are difficult to be queried. This research proposes a smart web query (SWQ) method for the semantic retrieval of web data. The SWQ method uses domain semantics represented as context ontologies to specify and formulate appropriate web queries to search. This method also relies on semantic search filters to identify and rank relevant web pages semi-automatically. Unlike traditional ontologies that are structured in a hierarchy, terms and their relationships that pertain to a particular domain are organized with a flexible structure by the context ontologies. An SWQ engine is being developed to test the proposed method. Financial trading (e.g. stocks, bonds, unit trusts) is adapted as an example domain (i.e., context) to test and validate the SWQ method and engine.

A smart web query method for semantic retrieval of web data

Contextual ontologies are ontologies that characterize a concept by a set of properties that vary according to context. Contextual ontologies are now crucial for users who intend to exchange information in a domain. Existing ontology languages are not capable of defining such type of ontologies. The objective of this paper is to formally define a contextual ontology language to support the development of contextual ontologies. In this paper, we use description logics as an ontology language and then we extend it by introducing a new contextual constructor.

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Contextual ontologies: motivations, challenges, and solutions

On the definition of generic multi-layered ontologies for urban applications

Identifying critical variables for coastal profiling in ICZM planning-A systems approach

The ocean, is fundamentally important to many areas of modern society and thus improved knowledge of the ocean is essential. Ocean scientists have made remarkable progress in observation technology, modeling and assimilation in physical oceanography, acoustics, and biology. To some extent, such advances have been confined to each discipline. Therefore a great demand has arisen for a modern distributed computing and networking infrastructure within which we bring together advanced modeling, observation tools and field estimation methods. The paper describes a knowledge network of distributed heterogeneous data and software resources for multidisciplinary ocean research.

The digital ocean

The objective of the Poseidon Coastal Zone Management System project is to develop a distributed data and software architecture to locate, retrieve, utilize, and visualize information about the coastal ocean environment. The article focuses on the issues related to efficiently identifying and creating the data needed for a given task. Since scientific data sets often do not contain information about the environment in which the data was obtained, we need a method of distinguishing data based on external information, or metadata. This metadata needs to be standardized in order to facilitate searching. While many metadata standards exist, none of them are adequate for representing all the information needed for coastal zone management. We have therefore implemented existing metadata standards in an expandable object oriented structure known as the Warwick Framework. Furthermore, since metadata is expensive and tedious to produce, we have developed a Web based software tool that simplifies the process and reduces the storage of redundant information. While we can search the metadata for the information we need, we still need a common vocabulary, or ontology, to ensure that we can identify data unambiguously. Since no existing vocabulary encapsulates all aspects of the ocean sciences and ocean systems management, we have facilitated the production of such a resource by creating a Web based tool that will allow specialists with the requisite domain knowledge to populate the ontology independently. The tool handles all the logistical issues of storage, maintenance and distribution.

P.C.H. Wariyapola

Papers

The digital ocean

Ontology and metadata creation for the Poseidon distributed Coastal Zone Management System