CS 6999 Semantic Web Techniques |
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Assignment 4 |
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This is syntactically and semantically
simplified RDF metadata about NRC IIT - e-Business's and UNB's homepages: <rdf:RDF>
<rdf:Description
about="http://www.iit.nrc.ca/www/E_Business/Research.html"> <name>NRC IIT - e-Business</name> <founded>2001</founded> <field>e-Business</field> <hosted-by
rdf:resource="http://www.unb.ca"/>
</rdf:Description>
<rdf:Description about="http://www.unb.ca"> <name>University of New
Brunswick</name>
<founded>1785</founded> <hosts
rdf:resource="http://www.iit.nrc.ca/www/E_Business/Research.html"/>
</rdf:Description> </rdf:RDF> 1.
Is this markup a well-formed XML element
(answer "yes" or "no")? Hint: A tag name or attribute
name of the form prefix:name is a legal XML name. 2.
Draw the directed labeled graph (DLG) that is the RDF diagram of the
- possibly corrected - markup. 3.
Which arcs of the DLG are represented as tags
with content and which arcs are empty tags using attributes (indicate this
directly in the RDF diagram with a "C" on content arcs and an
"A" on attribute arcs). Give RDF's technical terms for the nodes
that are targeted by the two kinds of arcs (fill in the blanks in the
following sentences): "Content arcs are targeting RDF
l_______" "Attribute arcs are targeting RDF
r________" 4.
If we remove all arc labels from such an RDF
DLG, indicate whether we obtain one or more of the following (write
"yes" or "no"): Node-labeled tree: DAG (directed acyclic graph): Directed graph: 5.
Give a set of Prolog facts representing the
same DLG as the markup does. 6.
Indicate the ways in which some or all of
these Prolog facts are only special cases of Horn facts (give as many answers
as possible from "some, yes", "all, yes", "some,
no", "all, no"): Ground facts (without variables as
arguments): Numeric facts (all arguments are numbers): Binary facts (2-argument facts): Datalog facts (without constructor terms as
arguments): Modal facts (make assertions about embedded
propositions): |
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Maintained by Bruce Spencer