Semantic Web

1. Semantic Web Faculty of Computer Science, IBA

2. Agenda • Overview of course and grading policy. • What is Semantic Web? Why we need it? Quratulain

3. Course Description • The World Wide Web (WWW) has changed the way in which people conduct business and shared knowledge. The explosive growth of the Web has led the problem of information overload. The Semantic Web can be seen as the solution to the problems of WWW. • In this course, we examine existing Semantic Web technologies: XML, RDF (Resource Description Framework), OWL (Web Ontology Language), understand the role of ontology, ontology modeling, reasoning, and querying mechanisms. • Latest papers published in recent Semantic Web conference proceedings and journals are also discussed. • This course also offers a practical experience using Protégé ontology editor, Jena ontology API with JAVA programming language. Students are required to complete the semantic web project at the end of the semester. Quratulain

4. Text Books • The Semantic Web primer by Grigoris Antoniou and Frank van Harmelen, MIT press. • Semantic Web Programming by John Hebeler, Matthew Fisher, Ryan Blace and Andrew Perez-Lopez. Quratulain

5. Tentative Course Outline • The Semantic Web Vision • Semantic Web Architecture • Structured Web Document in XML • Ontology languages: • RDF (Resource Description Framework) • RDFS (RDF Schema) • OWL (Web Ontology Language) • Ontology Development using Protégé editor • Ontology Querying • Ontology Reasoning and Description Logic (DL) • Semantic Web Application Areas • Ontology programming with Jena API • Ontology Engineering Quratulain

6. Tools and Programming Language • Protégé ontology editor • Jena ontology API • JAVA programming language • Eclipse IDE for JAVA programming Quratulain

7. Grading Policy • Midterm Exams: 30% • Final Exam: 30% • Assignments: 20% • Project: 20% Quratulain

8. Course Wiki • Check the website frequently for relevant links on tutorials, updated syllabus, lectures and assignments http://cse661semanticwebfall2011.wikispaces.com/ Quratulain

9. Contact Information • Email: quratrajput@yahoo.com • Cell: 03452324452 • Counseling hours: Tuesday and Thursday (3:00PM to 6:00PM) Quratulain

10. Course Feedback • First time course is being offered. • I encourage positive/negative feedback about how the class is going. Quratulain

11. Any question regarding course description. ? Quratulain

12. Today’s Web <tr> <td width="43%" align="left" valign="top" class="td"><div align="justify"><br /> IBA has 80 full time and 85 part time and visiting faculty members teaching courses in Management, Marketing, HR, Strategy, Finance, Economics, Quantitative Methods, Organizational Behavior, Computer Sciences, Ethics, Social Sciences, Chinese, Arabic. <br> &nbsp;</div></td> <td width="57%" valign="top" class="td"><div align="right"><br /> <img border="0" src="images/grp_fullfac_011010_small.jpg" width="400" height="147"></div></td> </tr> <tr> • HTML provides only presentation layout to the web content. Such as font size, color, hyperlinks. • Understandable by human. Quratulain

13. Today’s Web • Automatically generated data from databases also presented on web pages without following database structure. • For example, online library. • Once the query is performed on library database, the search result display on the web page as a text. Quratulain

14. Today’s Web • Querying • Find PhD scholarship in the field of Computer Science in Europe? • Lot of hard work require by users: • Search different scholarship web sites. • Read the detail of each scholarship ads. • Finally you can get information. • Not possible to review each scholarship ads due to large size of web content. Quratulain

15. Today’s Web Quratulain

16. Limitation of Today’s Web • Search results are highly depends on keywords. • High recall but low precision • Human involvement necessary to combine results. • Information is not processable by machines. • Lack of semantics. • Due to large size of web content, user cannot utilize most of the available information. • The structure of Web contents is heterogeneous. Therefore information cannot share or integrate automatically among web pages. Quratulain

17. Limitation of Today’s Web • No Querying system is available. • If the location of information is fixed then wrappers can be written to get information automatically. But specific to a website and become obsolete if the change location has been changed. • Other techniques based on Artificial Intelligence and computational linguistic can be applied for text processing but not capable enough. • Due to heterogeneous structure of web content not possible to apply one technique consistently over a large scale of web content. Quratulain

18. Today’s Web: impossible queries • Find the information about people that start using glasses before the age of 30? • Find information in data repository • Find average price of Honda civic model of the year 2000? • Find airline ticket with cheapest price from Karachi to Bangkok. • Delegating complex tasks to web “agents” • Book me a holiday next weekend somewhere warm, not too far away, and where they speak French or English Quratulain

19. Semantic Web Vision • Provide semantics to the web content. • Information on the web can be process by machine. • Automatic integration of information from different web pages. • Not only assigned metadata but also conceptualization of a domain knowledge. Processor Speed RAM Brand Hard disk I have an excellent condition HP Pavilion dv2500 Special Edition laptop with a core duo 1.5ghz processor 250gb hd and 2gb ram. It comes with Windows Vista Home Premium 32-bit. The case has a few scratches and the battery life is currently low lasting only 10-20min. However, if replaced probably for $30-40 it should last close to 6 hours. I am looking for $450 or best offer. Price Quratulain

20. Use Ontologies to provide semantic User definable and domain specific markup HTML: <H1>IBA FCS program</H1><UL> <LI>Instructor: Quratulain<LI>Course: Semantic Web </UL> XML: <FCS-Courses><title>IBA FCS program </title><instructor>Quratulain</instructor><Course>Semantic Web</Course></FCS-Courses> Quratulain

21. Semantic Web • According to W3C “an evolving extension of the World Wide Web in which web content can be … read and used by software agents, thus permitting them to find, share and integrate information more easily” Quratulain

22. From Today’s Web to Semantic Web • Examples • Knowledge management • B2C E-Commerce • B2B E-Commerce Quratulain

23. Knowledge Management • Knowledge management concerns itself with acquiring, accessing, and maintaining knowledge within an organization • Key activity of large businesses: internal knowledge as an intellectual asset from which they can increase their competitiveness. • Most information is currently available in a weakly structured form (e.g. text, audio, video) Quratulain

24. Knowledge management: Limitation of current technology • Searching information: Depends on keyword based search. • Extracting information: Human time and effort are required. • Maintaining information: Consistent information and remove outdated once. • Uncovering information: Difficult to apply data mining techniques on weakly structure document • Viewing information: Hard to realize a restricted view of information over Web. Quratulain

25. Semantic Web Enabled Knowledge Management • Knowledge will be organized in conceptual spaces according to its meaning. • Automated tools for maintenance and knowledge discovery • Semantic query answering • Query answering over several documents • Defining who may view certain parts of information (even parts of documents) will be possible. 25 Quratulain

26. The Semantic Web Impact: E-Commerce • A typical scenario: user visits one or several online shops, browses their offers, selects and orders products. • Ideally humans would visit all, or all major online stores; but too time consuming • Shopbots are a useful tool but have limitations • Rely on wrappers • Reprogrammed is costly if there is a change in online stores. • Relies on textual analysis 26 Quratulain

27. Semantic Web Enabled E-Commerce • Software agents that can interpret the product information and the terms of service. • Pricing and product information, delivery and privacy policies will be interpreted and compared to the user requirements. • Information about the reputation of shops • Sophisticated shopping agents will be able to conduct automated negotiations 27 Chapter 1 A Semantic Web Primer Quratulain

28. Semantic Web Impact • Wikis • Social networks • Tags • User Profiles Quratulain

29. Ontology • Knowledge Representation using Ontologies • Definition: • Wikipedia: is a formal representation of knowledge as a set of concepts within a domain, and the relationships between those concepts. It is used to reason about the entities within that domain, and may be used to describe the domain. • Webopedia: computer-based resources that represent agreed domain semantics...relatively generic knowledge that can be reused by different kinds of applications or tasks. • Gruber: A formal, explicit specification of a shared conceptualization Quratulain

30. Ontologies and Relational Databases • Similarities • Both use a model to identify common classes and properties • ER model can be seen as a simple hierarchical ontology • Differences • Ontologies are broader in scope (rules, incomplete knowledge) • Ontologies provide a way for automated reasoning to occur in order to discover new relationships between entities Quratulain Ramez Elmasri, Shamkant B. Navathe: Fundamentals of Database Systems, 3rd Edition. Benjamin/Cummings 2000

31. Reading Assignment • Berners-Lee, Hendler, Lassila, The Semantic Web, Scientific American, May 2001 • http://kill.devc.at/system/files/scientific-american_0.pdf Quratulain