OWL API - a key to semantic web

Hello! It's been a while....since my last post but I  had a lot of things to do!!!

Okay... Let's start! 

Today I will introduce OWL API which has been my best friend the last two months as I use it  evryday in the implementation of my thesis.

OWL API is a Java API  and reference implemantation for creating, manipulating and serializing OWL ontologies. The latest version of the API is focused towards OWL 2.

The OWL API is  open source and is available under LGPL License.

The OWL API includes the following components:

• An API for OWL 2 and an efficient in-memory reference implementation
• RDF/XML parser and writer
• OWL/XML parser and writer
• OWL Functional Syntax parser and writer
• Turtle parser and writer
• KRSS parser
• OBO Flat file format parser
• Reasoner interfaces for working with reasoners such as FaCT++, HermiT, Pellet and Racer

In my opinion OWL API has very good Documentantion (there are some examples of code in the official site)  and a great mail list!
Check it out!

Cheers,

Angeliki

Semantic Web books: Semantic Web Primer

Hello! I thought it would be nice to post details about some books I've read about Semantic Web.

The first book I I've read was "A Semantic Web Primer" by Grigoris Antoniou and Frank van Harmelen.

This is a good book for someone who wants to understand how RDF, OWL and ontologies work. But there are no examples of how can anybody  actually use RDF and OWL in applications.

A more formal description of the book:

The development of the Semantic Web, with machine-readable content, has the potential to revolutionize the World Wide Web and its use. A Semantic Web Primer provides an introduction and guide to this emerging field, describing its key ideas, languages, and technologies. Suitable for use as a textbook or for self-study by professionals, it concentrates on undergraduate-level fundamental concepts and techniques that will enable readers to proceed with building applications on their own. It includes exercises, project descriptions, and annotated references to relevant online materials. A Semantic Web Primer is the only available book on the Semantic Web to include a systematic treatment of the different languages (XML, RDF, OWL, and rules) and technologies (explicit metadata, ontologies, and logic and inference) that are central to Semantic Web development. The book also examines such crucial related topics as ontology engineering and application scenarios. 

After an introductory chapter, topics covered in succeeding chapters include XML and related technologies that support semantic interoperability; RDF and RDF Schema, the standard data model for machine-processable semantics; and OWL, the W3C-approved standard for a Web ontology language more extensive than RDF Schema; rules, both monotonic and nonmonotonic, in the framework of the Semantic Web; selected application domains and how the Semantic Web would benefit them; the development of ontology-based systems; and current debates on key issues and predictions for the future.

You can take a limited inside look here

Cheers,

Angeliki

Jena - a semantic web framework

Hello! Today I will introduce Jena - a framework for building semantic web applications.


From the official site of Jena:

Jena is a Java framework for building Semantic Web applications. It provides a programmatic environment for RDF, RDFS and OWL, SPARQL and includes a rule-based inference engine.

Jena is open source and grown out of work with the HP Labs Semantic Web Programme.

The Jena Framework includes:

• A RDF API
• Reading and writing RDF in RDF/XML, N3 and N-Triples
• An OWL API
• In-memory and persistent storage
• SPARQL query engine

Besides, Jena's documentation in sourceforge I found very useful this article by IBM for an introduction on how Jena works.

Another useful link, is this youtube video, which gives detailed instructions on using Jena in Netbeans. I don't know what language is this, but I understood what to do. :)

Cheers,

Angeliki

Semantic Web keywords

• Semantic Web: Semantic Web is a group of methods and technologies to allow machines to understand the meaning - or "semantics" - of information on the "World Wide Web". (wikipedia)
• Ontology: In computer and information science, an ontology 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 (see reasoning definition)about the entities within that domain, and may be used to describe the domain.(wikipedia)
• Reasoning : Reasoning is the cognitive process of looking for reasons, beliefs, conclusions, actions or feelings. (wikipedia)
• OWL: The Web Ontology Language (OWL) is a family of knowledge representation languages for authoring ontologies. The languages are characterised by formal semantics and RDF/XML-based serializations for the Semantic Web. OWL is endorsed by the World Wide Web Consortium (W3C) and has attracted academic, medical and commercial interest. In October 2007, a new W3C working group was started to extend OWL with several new features as proposed in the OWL 1.1 member submission. This new version, called OWL 2, soon found its way into semantic editors such as Protégé and semantic reasoners such as Pellet,RacerPro, FaCT++ and HermiT. (wikipedia)

Cheers,
Angeliki