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Number of items: 5.
Article
Automatic Ontology-Based Knowledge Extraction from Web Documents
http://jb4-2.eprints-hosting.org/2154
To bring the Semantic Web to life and provide advanced knowledge services, we need efficient ways to access and extract knowledge from Web documents. Although Web page annotations could facilitate such knowledge gathering, annotations are rare and will probably never be rich or detailed enough to cover all the knowledge these documents contain. Manual annotation is impractical and unscalable, and automatic annotation tools remain largely undeveloped. Specialized knowledge services therefore require tools that can search and extract specific knowledge directly from unstructured text on the Web, guided by an ontology that details what type of knowledge to harvest. An ontology uses concepts and relations to classify domain knowledge. Other researchers have used ontologies to support knowledge extraction,1,2 but few have explored their full potential in this domain. The Artequakt project links a knowledge-extraction tool with an ontology to achieve continuous knowledge support and guide information extraction. The extraction tool searches online documents and extracts knowledge that matches the given classification structure. It provides this knowledge in a machine-readable format that will be automatically maintained in a knowledge base (KB). Users could further enhance knowledge extraction using a lexicon-based term expansion mechanism that provides extended ontology terminology.
Harith Alani
Sanghee Kim
David E. Millard
Mark J. Weal
Wendy Hall
Paul H. Lewis
Nigel R. Shadbolt
http://jb4-2.eprints-hosting.org/2154
To bring the Semantic Web to life and provide advanced knowledge services, we need efficient ways to access and extract knowledge from Web documents. Although Web page annotations could facilitate such knowledge gathering, annotations are rare and will probably never be rich or detailed enough to cover all the knowledge these documents contain. Manual annotation is impractical and unscalable, and automatic annotation tools remain largely undeveloped. Specialized knowledge services therefore require tools that can search and extract specific knowledge directly from unstructured text on the Web, guided by an ontology that details what type of knowledge to harvest. An ontology uses concepts and relations to classify domain knowledge. Other researchers have used ontologies to support knowledge extraction,1,2 but few have explored their full potential in this domain. The Artequakt project links a knowledge-extraction tool with an ontology to achieve continuous knowledge support and guide information extraction. The extraction tool searches online documents and extracts knowledge that matches the given classification structure. It provides this knowledge in a machine-readable format that will be automatically maintained in a knowledge base (KB). Users could further enhance knowledge extraction using a lexicon-based term expansion mechanism that provides extended ontology terminology.
Harith Alani
Sanghee Kim
David E. Millard
Mark J. Weal
Wendy Hall
Paul H. Lewis
Nigel R. Shadbolt
Conference or Workshop Item
Social Web Communities
http://jb4-2.eprints-hosting.org/2160
Blogs, Wikis, and Social Bookmark Tools have rapidly emerged on the Web. The reasons for their immediate success are that people are happy to share information, and that these tools provide an infrastructure for doing so without requiring any specific skills. At the moment, there exists no foundational research for these systems, and they provide only very simple structures for organising knowledge. Individual users create their own structures, but these can currently not be exploited for knowledge sharing. The objective of the seminar was to provide theoretical foundations for upcoming Web 2.0 applications and to investigate further applications that go beyond bookmark- and file-sharing. The main research question can be summarized as follows: How will current and emerging resource sharing systems support users to leverage more knowledge and power from the information they share on Web 2.0 applications? Research areas like Semantic Web, Machine Learning, Information Retrieval, Information Extraction, Social Network Analysis, Natural Language Processing, Library and Information Sciences, and Hypermedia Systems have been working for a while on these questions. In the workshop, researchers from these areas came together to assess the state of the art and to set up a road map describing the next steps towards the next generation of social software.
Harith Alani
Steffen Staab
Gerd Stumme
http://jb4-2.eprints-hosting.org/2160
Blogs, Wikis, and Social Bookmark Tools have rapidly emerged on the Web. The reasons for their immediate success are that people are happy to share information, and that these tools provide an infrastructure for doing so without requiring any specific skills. At the moment, there exists no foundational research for these systems, and they provide only very simple structures for organising knowledge. Individual users create their own structures, but these can currently not be exploited for knowledge sharing. The objective of the seminar was to provide theoretical foundations for upcoming Web 2.0 applications and to investigate further applications that go beyond bookmark- and file-sharing. The main research question can be summarized as follows: How will current and emerging resource sharing systems support users to leverage more knowledge and power from the information they share on Web 2.0 applications? Research areas like Semantic Web, Machine Learning, Information Retrieval, Information Extraction, Social Network Analysis, Natural Language Processing, Library and Information Sciences, and Hypermedia Systems have been working for a while on these questions. In the workshop, researchers from these areas came together to assess the state of the art and to set up a road map describing the next steps towards the next generation of social software.
Harith Alani
Steffen Staab
Gerd Stumme
Thesaural and Spatial Knowledge in Cultural Heritage Information Retrieval Systems
http://jb4-2.eprints-hosting.org/2148
There is an increasing interest by cultural heritage organisations in developing hypermedia information systems to provide efficient ways to document, maintain, and search their data collections, and to open them to public access. However, search and retrieval of spatial data is known to suffer from many difficulties. Places normally have different versions of names, often change in size, boundaries, and centre co-ordinates. Furthermore, similarity between places is hard to calculate due to the wide range of characteristics associated with places and the complexity of inferring spatial relationships. This paper presents the research project OASIS, which attempts to improve spatial retrieval using a spatial hierarchy of places, enriched with thematic and geographical thesauri. OASIS applies a set of spatial measures to improve access by imprecisely matching places names.
Harith Alani
Christopher Jones
Douglas Tudhope
http://jb4-2.eprints-hosting.org/2148
There is an increasing interest by cultural heritage organisations in developing hypermedia information systems to provide efficient ways to document, maintain, and search their data collections, and to open them to public access. However, search and retrieval of spatial data is known to suffer from many difficulties. Places normally have different versions of names, often change in size, boundaries, and centre co-ordinates. Furthermore, similarity between places is hard to calculate due to the wide range of characteristics associated with places and the complexity of inferring spatial relationships. This paper presents the research project OASIS, which attempts to improve spatial retrieval using a spatial hierarchy of places, enriched with thematic and geographical thesauri. OASIS applies a set of spatial measures to improve access by imprecisely matching places names.
Harith Alani
Christopher Jones
Douglas Tudhope
Winnowing Ontologies based on Application Use
http://jb4-2.eprints-hosting.org/2144
The requirements of specific applications and services are often over estimated when ontologies are reused or built. This sometimes results in many ontologies being too large for their intended purposes. It is not uncommon that when applications and services are deployed over an ontology, only a few parts of the ontology are queried and used. Identifying which parts of an ontology are being used could be helpful to winnow the ontology, i.e., simplify or shrink the ontology to smaller, more fit for purpose size. Some approaches to handle this problem have already been suggested in the literature. However, none of that work showed how ontology-based applications can be used in the ontology-resizing process, or how they might be affected by it. This paper presents a study on the use of the AKT Reference Ontology by a number of applications and services, and investigates the possibility of relying on this usage information to winnow that ontology.
Harith Alani
Stephen Harris
Ben O'Neil
http://jb4-2.eprints-hosting.org/2144
The requirements of specific applications and services are often over estimated when ontologies are reused or built. This sometimes results in many ontologies being too large for their intended purposes. It is not uncommon that when applications and services are deployed over an ontology, only a few parts of the ontology are queried and used. Identifying which parts of an ontology are being used could be helpful to winnow the ontology, i.e., simplify or shrink the ontology to smaller, more fit for purpose size. Some approaches to handle this problem have already been suggested in the literature. However, none of that work showed how ontology-based applications can be used in the ontology-resizing process, or how they might be affected by it. This paper presents a study on the use of the AKT Reference Ontology by a number of applications and services, and investigates the possibility of relying on this usage information to winnow that ontology.
Harith Alani
Stephen Harris
Ben O'Neil
Ranking Ontologies with AKTiveRank
http://jb4-2.eprints-hosting.org/2138
Ontology search and reuse is becoming increasingly important as the quest for methods to reduce the cost of constructing such knowledge structures continues. A number of ontology libraries and search engines are coming to existence to facilitate locating and retrieving potentially relevant ontologies. The number of ontologies available for reuse is steadily growing, and so is the need for methods to evaluate and rank existing ontologies in terms of their relevance to the needs of the knowledge engineer. This paper presents AKTiveRank, a prototype system for ranking ontologies based on a number of structural metrics.
Harith Alani
Christopher Brewster
Nigel Shadbolt
http://jb4-2.eprints-hosting.org/2138
Ontology search and reuse is becoming increasingly important as the quest for methods to reduce the cost of constructing such knowledge structures continues. A number of ontology libraries and search engines are coming to existence to facilitate locating and retrieving potentially relevant ontologies. The number of ontologies available for reuse is steadily growing, and so is the need for methods to evaluate and rank existing ontologies in terms of their relevance to the needs of the knowledge engineer. This paper presents AKTiveRank, a prototype system for ranking ontologies based on a number of structural metrics.
Harith Alani
Christopher Brewster
Nigel Shadbolt