Tharaka Devadithya's space: Notes

Concepts Related to RDF

Wed, 20 Dec 2006 22:39:42 GMT

Semi-Structured Data - Peter Wood
Description Logic - Course Notes
Sub-graph Isomorphism Problem (distributed)

RDF Vs. XML

XML and RDF (blog)
Why RDF model is different from the XML model (link)
- In XML, there are many ways to represent something like "The author of the page is Ora". In RDF, there is only one way.
- While all the different ways may convey some meaning for the human reader, it will not be the case for a computer.
- Querying in XML is more complex due to many ways of representing the same thing.
- Mapping from XML to RDF is many-to-one.
Using XML for Data (link)
- An XML document can't have disjoint parts and therefore XML doesn't map 1-1 with a directed, labeled graph.
Is RDF/XML Good for Anything? (link)
- XML is designed to describe trees. RDF/XML is a transfer syntax for graphs.

What the Semantic Web can represent (link)

The Semantic Web and Entity-Relationship models
- RDF is similar to E-R model except that relationships are first class objects in RDF.
- In RDF, the set of slots of an object is not defined when the class of an object is defined.
The Semantic Web and Relational Databases
- In DB, a query can join tables by any comlumns which match by datatype.

SPARQL Vs. RDQL

From RDQL to SPARQL (blog)

Advantages of SPARQL

Supports named graphs - query contains a FROM clause to specify the graph
Supports queries with typed literals
Sort results

Ontologies

Wed, 20 Dec 2006 21:26:39 GMT

Misconceptions about OWL Reasoning - Harry Chen
... this classification could create misconceptions that lead people to wrongly interpret the properties of different OWL reasoning. For example, a common belief is that when you build an ontology, you should attempt to stay within OWL-DL because OWL-DL reasoners is more efficient that OWL-Full reasoners. Some others believe that the use of OWL-Full will always cause intractable computation performance in a reasoner.

Undecidable systems - Quoll

...just because a system is undecidable does not mean that it is useless. Turing complete languages (such as Java or C) are not guaranteed to complete (while(true) {...}) and yet these languages are still quite useful. Programmers just have to be careful that their constructs terminate.

Academic

Thu, 28 Sep 2006 12:29:07 GMT

Writing and Presenting Your Thesis or Dissertation

Graduate school survival guide

How To Write a Thesis Statement

Technical Stuff

Mon, 21 Aug 2006 22:05:03 GMT

Member as offset from object address - Discussion