Posts Tagged ‘Introduction’

Introduction to: Reasoners

Name Tag: Hello, we are ReasonersReasoning is the task of deriving implicit facts from a set of given explicit facts. These facts can be expressed in OWL 2 ontologies and stored RDF triplestores. For example, the following fact: “a Student is a Person,” can be expressed in an ontology, while the fact: “Bob is a Student,” can be stored in a triplestore. A reasoner is a software application that is able to reason. For example, a reasoner is able to infer the following implicit fact: “Bob is a Person.”

Reasoning Tasks

Reasoning tasks considered in OWL 2 are: ontology consistency, class satisfiability, classification, instance checking, and conjunctive query answering.

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Introduction to: Triplestores

Badge: Hello, my name is TriplestoreTriplestores are Database Management Systems (DBMS) for data modeled using RDF. Unlike Relational Database Management Systems (RDBMS), which store data in relations (or tables) and are queried using SQL, triplestores store RDF triples and are queried using SPARQL.

A key feature of many triplestores is the ability to do inference. It is important to note that a DBMS typically offers the capacity to deal with concurrency, security, logging, recovery, and updates, in addition to loading and storing data. Not all Triplestores offer all these capabilities (yet).

Triplestore Implementations

Triplestores can be broadly classified in three types categories: Native triplestores, RDBMS-backed triplestores and NoSQL triplestores. Read more

Getting Started with the Semantic Web Using SPARQL with R

A new article on R Bloggers explains how to get “up and running on the Semantic Web” using SPARQL with R in under five minutes. The article states, “We’ll use data at the Data.gov endpoint for this example. Data.gov has a wide array of public data available, making this example generalizable to many other datasets. One of the key challenges of querying a Semantic Web resource is knowing what data is accessible. Sometimes the best way to find this out is to run a simple query with no filters that returns only a few results or to directly view the RDF. Fortunately, information on the data available via Data.gov has been cataloged on a wiki hosted by Rensselaer. We’ll use Dataset 1187 for this example. It’s simple and has interesting data – the total number of wildfires and acres burned per year, 1960-2008.” Read more

Infographic: The Importance of RDFa

Mind Development and Design has shared an infographic on The Importance of RDFa. The article states, “RDFa (or Resource Description Framework – in – attributes) is a W3C Recommendation that adds a set of attribute-level extensions to HTML, XHTML and various XML-based document types for embedding rich metadata within Web documents. What does that mean? It means that RDFa give your content more meaning… it allows content to make sense to the search engines.” Read more

Video: Linked Data for Libraries

The OCLC has created a video entitled Linked Data for Libraries. The fourteen minute video provides an introduction to the concepts and technology behind linked data as well as how linked data works and how it is used in libraries.

According to the organization website, “OCLC is a nonprofit, membership, computer library service and research organization dedicated to the public purposes of furthering access to the world’s information and reducing information costs. Read more

Presentation: SPARQL, Queries, & Linked Data

A new presentation from the ICWE Conference is available online. The presentation is titled An Introduction to SPARQL and Queries over Linked Data: “Nowadays, more and more datasets are published on the Web adhering to the Linked Data principles. The availability of this data, including the existence of data-level connections between datasets, presents exciting opportunities for the next generation of Web-based applications. As a consequence, consuming Linked Data is a highly relevant topic in the context of Web engineering. Our introductory tutorial aims to provide participants with an understanding of one of the basic aspects of Linked Data consumption, that is, querying Linked Data.” Read more

Linked Data: An Introduction

John Goodwin has written a useful introduction to linked data. He begins, “In the early 1990s there began to emerge a new way of using the internet to link documents together. It was called the World Wide Web. What the Web did that was fundamentally new was that it enabled people to publish documents on the internet and link them such that you could navigate from one document to another. Part of Sir Tim Berners-Lee’s original vision of the Web was that it should also be used to publish, share and link data. This aspect of Sir Tim’s original vision has gained a lot of momentum over the last few years and has seen the emergence of the Linked Data Web.” Read more

Semantic Web Lessons from Cambridge Semantics

As part of their Semantic University, Cambridge Semantics has published a number of helpful “lessons” covering concepts related to the Semantic Web. Since we last checked in with this excellent tutorial series, they have added several lessons:

Semantic Web vs. Semantic Technologies – “That Semantic Web technologies and semantic technologiesboth start with semantic is often a source of confusion. This short lesson clarifies the relationship between Semantic Web technologies and semantic technologies.” Read more

Introduction to: RDFa

Name Badge - Hello, My Name is RDFaSimply put, RDFa is another syntax for RDF. The interesting aspect of RDFa is that it is embedded in HTML. This means that you can state what things on your HTML page actually mean. For example, you can specify that a certain text is the title of a blog post or it’s the name of a product or it’s the price for a certain product. This is starting to be commonly known as “adding semantic markup”.

Historically, RDFa was specified only for XHTML. Currently, RDFa 1.1 is specified for XHTML and HTML5. Additionally, RDFa 1.1 works for any XML-based language such as SVG. Recently, RDFa Lite was introduced as “a small subset of RDFa consisting of a few attributes that may be applied to most simple to moderate structured data markup tasks.” It is important to note that RDFa is not the only way to add semantics to your webpages. Microdata and Microformats are other options, and I will discuss this later on. As a reminder, you can publish your data as Linked Data through RDFa. Inside your markup, you can link to other URIs or others can link to your HTML+RDFa webpages.

Why publish RDFa? Read more

Learn Ontology Development at SemTechBiz DC

In less than one week SemTechBiz DC will arrive at the Kellogg Conference Hotel in Washington, DC. The conference, which takes place November 29-December 1, 2011, will feature highly-anticipated sessions led by top thinkers in the fields of Open Government, Content Management, Enterprise Data Management, Linked Data, and much more.

Featured Presentation

Photo of Presenters Elisa Kendall and Deborah L. McGuinness

Elisa Kendall and Deborah L. McGuinness

Ontology 101: An Introduction to Knowledge Representation and Ontology Development with Elisa Kendall, Partner – Thematix LLC and Deborah McGuinness, Tetherless World Chaired Constellation Professor – Rensselaer Polytechnic Institute (RPI)

This presentation will provide an introductory-level technical examination of ontologies. Read more

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