EXERCISES INF3580 SPRING 2010 WEEK 9
A bird.
This document contains exercises made for INF3580. Please send any comments, errors, bug or improvement reports to this exercise set to martige@ifi.uio.no. Feedback is most welcome! Alphabetically thanks to Audun Stolpe, Espen H. Lian, Martin Giese and Rune Dahl for feedback.
The main curriculum for INF3580 spring 2010 is Semantic Web Programming by John Hebeler et al., Wiley Publishing, 2009. They have a website with additional articles and all source code used in the book at http://semwebprogramming.org/. Auxiliary curriculum is the book Foundations of Semantic Web Technologies by Hitzler, Krützsch, Rudolph, CRC Press 2009.
Keep all the work you do for these exercises in a safe
place. Setting up a version control system like cvs, svn or
git for the work you do is smart. You can create a svn repository
on IfI's svn server, see their help section for more
information. There is also a walk-through from old INF3120 on how to
set up a svn repository and connect it to Eclipse, but news is
that you'll need the plug-in subclipse to make it work. Please
contact me if you have any smart tips to share.
1 Even more OWL
Read
- Semantic Web Programming: chapter 4, 5
- Foundations of Semantic Web Technologies: chapter 4, 5.
1.1 The Simpsons in OWL 2
In this exercise we will extend the family ontology by using OWL 2 vocabulary. OWL 2 adds expressivity to OWL DL without becoming undecidable. For an overview of the new features of OWL 2 see OWL 2 Web Ontology Language: New Features and Rationale.
1.1.1 Exercise
Create a new ontology which imports the family OWL ontology we made in last week's exercises.
1.1.2 Exercise
State that a person have exactly one gender.
1.1.3 Exercise
Explain what owl keys are.
How would you state that fam:hasName is key for Person?
1.1.3.1 Tip
At the time of writing this exercise Protege 4 does not seem to support OWL keys, but claimed in 16. June 2009 to be out with a 4.1. alpha version which will support /the late entry OWL 2 features that didn't make it into Protege 4.0, e.g., keys/. Protege 4.0 Release – June 16, 2009.
1.1.4 Exercise
Identify the correct characteristics of all properties in the ontology, i.e., which properties are
- asymmetric
- reflexive
- irreflexive
Explain what asymmetric, reflexive and irreflexive properties are. Use examples.
1.1.4.1 Tip
Note that the exercise says "identify" and not "add". The reason for this is that not all combinations of property characteristics are admissible in OWL 2. Adding more property characteristics carelessly will cause reasoners to report errors. For more information see the paper The even more irresistible SROIQ by Horrocks et al. SROIQ is the description logic which is the logical basis for OWL 2.
1.1.5 Exercise
Explain what it means for two properties to be disjoint. Add the natural disjoint axioms for properties in the ontology.
1.1.6 Exercise
Explain what property chaining is. Using property chaining, define the properties
-
fam:hasAunt -
fam:hasGrandParent -
fam:hasUncle
as equivalent to the correct property chain.
Create two new properties
-
:hasGrandMother -
:hasGrandFather
in the same manner.
1.1.7 Exercise
Define a class Minor as a Person which is under the age of 18.
Define a class Juvenile as a Person which is under the age of 16.
1.1.8 Exercise
Add a class Job and a object property hasJob with domain Person and range Job.
Define a class Retiree as a Person which is over 66 years old and has no Job.
Date: 2010-04-12 15:49:26 CEST
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