Final Presentation on Semantic Web

1. Infromation Reprentation,
Structured Data and Semantics
Yogendra Tamang
070-MSCS-670

2. OUTLINE
• XML, DTD and XML Schema, XSLT
• Meta data Standards.
• Information Representation in Semantic Web
• RDF, RDFS
• Syntactic Formats
• RDF/XML, N-triples, Turtles etc.
• Embedded Formats
• RDFs, Microformats, eRDF, HTML5, GRDDL, SPARQL

3. XML
Thing! Elements
XML
Documents Epilogue
Prolog
XML
Declaration and
Reference
Tag,
Attributes
and
Content
<?xml version="1.0" encoding="UTF-16"?>
<!DOCTYPE book SYSTEM "book.dtd">
<lecturer>David Billington</lecturer>

4. XML
• Comments and Processing Instructions
<!-- This is a comment -->
<?stylesheet type="text/css" href="mystyle.css"?>

5. DTD and XML Schema
• Used for defining the structure
• what values an attribute may take
• which elements may or must occur within other elements, etc.
<lecturer>
<name>David Billington</name>
<phone> +61 − 7 − 3875 507 </phone>
</lecturer>
<!ELEMENT lecturer (name,phone)>
<!ELEMENT name (#PCDATA)>
<!ELEMENT phone (#PCDATA)>

6. DTD
Disjunctions:
<!ELEMENT lecturer (name|phone)>
<!ELEMENT lecturer((name,phone)|(phone,name))>

7. DTD
<order orderNo="23456" customer="John Smith" date="October 15, 2002">
<item itemNo="a528" quantity="1"/>
<item itemNo="c817" quantity="3"/>
</order>
<!ELEMENT order (item+)>
<!ATTLIST order orderNo ID #REQUIRED
customer CDATA #REQUIRED
date CDATA #REQUIRED>
<!ELEMENT item EMPTY>
<!ATTLIST item itemNo ID #REQUIRED
quantity CDATA #REQUIRED
comments CDATA #IMPLIED>

8. XML Schema
<schema http://www.w3.org/2000/10/XMLSchema version="1.0">
Element and Attribute Types using Data Types
• Numerical data types: integer, Short etc.
• String types: string, ID, IDREF, CDATA etc.
• Date and time data types: time, Month etc.
• User defined(Simple and Comlpex)

9. XML Namespaces and XPATH
• Form:
xmlns:prefix="location“
• XPATH:
Operates on Tree data model and is core for XML query lanaguage

10. XSLT
• XSLT specifies rules with which an input XML document
is transformed to
• another XML document
• an HTML document
• plain text

11. RDF
• It provides a uniform framework for interchange of
data and metadata between applications
• XML does not provide any means of talking about the
semantics (meaning) of data
• Object-Attribute-Value

12. RDF
• Fundamental Concepts:
• resources
• properties
• statements

13. Statements
• Triples
• (x, P, y)  P(x, y)

14. RDFS Core Classes
• rdfs:Resource, the class of all resources
• rdfs:Class, the class of all classes
• rdfs:Literal, the class of all literals (strings)
• rdf:Property, the class of all properties.
• rdf:Statement, the class of all reified statements

15. RDFS Core Properties
• rdf:type, which relates a resource to its class
• The resource is declared to be an instance of that class
• rdfs:subClassOf, which relates a class to one of its
superclasses
• All instances of a class are instances of its superclass
• rdfs:subPropertyOf, relates a property to one of its
superproperties
• rdfs:domain,
• rdfs:range,

16. RDF Sparql Query
• SPARQL is based on matching graph patterns
• Example:
PREFIX rdf: <http://www.w3.org/1999/02/22-rdf-syntax-ns#>
PREFIX rdfs: <http://www.w3.org/2000/01/rdf-schema#>
SELECT ?c
WHERE
{
?c rdf:type rdfs:Class .
}

17. RDFa
• RDFa is an extension to HTML5 that helps you markup things like
People, Places, Events, Recipes and Reviews. Search Engines and Web
Services use this markup to generate better search listings and give
you better visibility on the Web, so that people can find your website
more easily

18. Microformats
• microformats are a set of simple, open data formats built upon
existing and widely adopted standards

19. MicroFormats Tools and Code generators

23. Ntriples

24. Green Turtle RDFa

25. Green Triples
• an implementation of RDFa 1.1 for browsers
• When triples are discovered in a web page, a little green turtle
will appear in the address bar. If you click on that turtle, you can
view the triple graph.

28. References
• “Semantic Web Primer”, Grigoris Antoniou, Frank van Harmelen
• http://rdfa.info/
• https://code.google.com/p/green-turtle/
• http://microformats.org/wiki/about