URL: http://bombadil.mindlab.umd.edu/cgi-bin/urchin
Date created: 2004-07-29
Description:
Urchin is a customizable RSS aggregator and filter written in Perl. It consists of two main parts: a web-based user interface to query its database and an administration unit that allows the control for managing channels in the database. Administrators can add RSS 0.9*, 1.0, and 2.0 channels to the Urchin, where items are converted into RDF and stored in its native mySQL database. Using the web interface, user can query the database using Urchin-specific keywords, plaintext, or the RCQL query language. Urchin can then display the results as several output formats, including RSS 1.0 and RSS 0.91 feeds. This aggregation allows each user to create a RSS feed tailored to the individual's interest from the available channels in the database. In addition, Urchin is suitable for building a RSS portal service.
The Urchin-Kowari project replaces the mySQL database with the specialized RDF triple store Kowari. This takes advantage of the fact that all data in Urchin are RDF statements and Kowari is a specialized RDF database. Urchin and Kowari communicate via SOAP, and can be running on different machines. This decoupling of interface and storage allows users the freedom to access any available Kowari server on the Web. In Urchin-Kowari, the core Urchin functionalities are preserved as much as possible. The Web interface retains its look, but query syntax has been modified. Raw iTQL queries to the storage replace the RCQL queries. Many Urchin keywords are being developed. Administrative control of the channels is also preserved.
The current implementation is written using Urchin 0.90 and Kowari 1.0.5
(pre-release, dated July 29, 2004).
Contact:
Kendall Clark
University of Maryland, MIND Laboratory
Taowei David Wang
University of Maryland, MIND Laboratory
Jay Banerjee
University of Maryland, MIND Laboratory
More information:
Original Urchin information page (now v. 0.92),
Original Kowari information page
A new property 'skos:hasTopConcept' has been added to the SKOS Core vocabulary. This property replaces the class skos:TopConcept, which is now deprecated.
This new property is added to support the modelling of concepts that are members of more than one scheme, and where a concept may be a top concept in one scheme and not in another.
So now, to indicate that some concept is a top concept in a specific scheme, do e.g. the following:
@prefix skos: <http://www.w3.org/2004/02/skos/core#>.
@prefix ex: <http://example.org/>.
ex:myConceptScheme
skos:hasTopConcept ex:conceptA;
skos:hasTopConcept ex:conceptB;
skos:hasTopConcept ex:conceptC.
The RDF description of the new property skos:hasTopConcept is as follows:
<rdf:Property rdf:ID="hasTopConcept"> <rdfs:label>has top concept</rdfs:label> <rdfs:domain rdf:resource="#ConceptScheme"/> <rdfs:range rdf:resource="#Concept"/> <rdfs:comment>Use this property to indicate that a concept is a top concept in a specific concept scheme.</rdfs:comment> <rdfs:isDefinedBy rdf:resource="http://www.w3.org/2004/02/skos/core"/> <vs:term_status>testing</vs:term_status> <owl:versionInfo>This property replaces the deprecated skos:TopConcept class.</owl:versionInfo> <dct:replaces rdf:resource="#TopConcept"/> <dct:created>2004-08-19</dct:created> </rdf:Property>
The RDF description of the old class skos:TopConcept is now as follows:
<owl:DeprecatedClass rdf:ID="TopConcept">
<rdfs:label>Top Concept</rdfs:label>
<rdfs:comment>A concept that sits at the top of the concept hierarchy.</rdfs:comment>
<rdfs:isDefinedBy rdf:resource="http://www.w3.org/2004/02/skos/core"/>
<vs:term_status>unstable</vs:term_status>
<owl:versionInfo>This class is now deprecated. To indicate that a concept is a top concept in a scheme, now use the skos:hasTopConcept property.</owl:versionInfo>
<dct:isReplacedBy rdf:resource="#hasTopConcept"/>
<dct:modified>2004-08-19</dct:modified>
</owl:DeprecatedClass>
The SKOS Mapping RDF Vocabulary has been moved to the w3.org namespace.
The new namespace for SKOS Mapping is:
http://www.w3.org/2004/02/skos/mapping#
The HTTP link for the source RDF is:
http://www.w3.org/2004/02/skos/mapping.rdf
This is now the permanent home for SKOS Mapping. Apologies for any
inconvenience caused.
Some minor mostly technical (and not design) changes to the SKOS Core vocabulary:
- the XML doctype has been changed to 'rdf:RDF'
- the entity 'vs' has been added with value the vocab status namespace
- xmlns:vs added
- dct:modified date updated
- dc:title for the schema changed to 'SKOS Core RDF Vocabulary'
- dc:contributor added for members of public-esw-thes list
- rdfs:isDefinedBy property added for each term
- the initial XML comment at the top of the file has been rewritten
Term status values have been added to all the terms in the SKOS Core RDF Vocabulary. The initial values are as follows:
Nothing has been given an initial value of 'stable' to allow for the rdfs:comments to be modified. (The idea is that once a term reaches a 'stable' status, it is understood that none of its properties will change further.)
Please feel free to recommend any of these terms for a 'stable' status if you feel they deserve to be so, and the rdfs:comments are satisfactory.
Following the successful spanish-language workshop in Spain, the SWAD-E project will be taking advantage of an opportunity to participate in a workshop in Argentina in August. This continues the outreach to non-english speaking developers that is one of the goals of the project.
Thanks to the Universidad Kennedy of Buenos Aires, Diego Ferreyra of the Argentine government, Eva Méndez, Leandro Mariano López, and others, the workshop bring developers together to discuss their work, and examine how to learn from the SWAD-E project to further development of the Semantic Web. The workshop will take advantage of two conferences taking place in Buenos Aires bringing interested participants from around South America who will be able to participate in the workshop.
Further visibility of work being done in non-english languages, such as spanish and french, should increase the quality of work taking place across Europe, not just in the english-speaking countries of the world. The investment made by the SWAD-E project in this area has already shown important returns in increased dissemination of work in a number of languages, and in collaboration that has improved the quality of individual projects.
There are a number of presentations and documents in languages other than english linked from the project home page. Other resources include the recent workshop on "metadata in a multilingual world", and the geographic information project being developed primarily in french.
An occasional meeting of W3Québec, a group who are interested in web standards in francophone Canada, was the opportunity to talk about the Semantic Web. It motivated some work on translation of existing resources, and hopefull also some more development by francophones, which can only help dissemination across Europe and particularly french-speaking Africa.
Material produced for the session included a french translation of Hera, a tool designed to help assess web accesibility and produce results in RDF, as well as a french version of my "Introduction to RDF via CWM" (I really should make an english version, although there is plenty of material in english already).
Thanks to all who participated, especially Karl Dubost of W3C for his lively explanations and re-explanations, Monique and Alex for logistics support, and above all Catherine Roy, who organised the whole thing.