Semantic web

Agenda

• World Wide Web

• Semantic Web

• Semantic Web Tools and Applications

• Linking Open Data

• Social Semantic Web

• Open Government

Agenda

World Wide Web

• Semantic Web




• Open Government

World Wide Web

a system of interlinked hypertext documents accessed via the Internet

Web Architecture

Document

Identifier Protocol

URI HTTP

HTML

an application protocol for

distributed, collaborative,

hypermedia information systems

a string of characters

used to identify a name

or a resource

the main markup language for

displaying web pages and other

information that can be displayed

in an web browser

HTML is used

to display web pages

for human.

<a href="http://en.wikipedia.org/wiki/Html">

HTML

</a>

<a href="http://en.wikipedia.org/wiki/World_Wide_Web">

Web

</a>

hyperlink

hyperlink

Hyperlink in HTML is

a reference to document.

What is problem?

Cars.com AutoTrader.com

same

information,

but …

How to use it for machine as data?

Agenda

• World Wide Web

Semantic Web




• Open Government

providing a common framework that allows data to be shared and

reused across application, enterprise, and community boundaries

A6

Car

Gasoline

3.0L V6

24V GDI

8-Speed

Automatic Sedan

4

AWD

115”

type

transmission

wheelbase

engine

fuel

drivetrain

doors

body_style

Basic Concept for Data Description

on the Semantic Web

Semantic Web Layer Cake

URI (Uniform Resource Identifier)

a string of characters used to identify a name or a resource

URN (Uniform Resource Name)

URL (Uniform Resource Locator) +

URI

urn:isbn:0451450523

urn:isan:0000-0000-9E59-0000-O-0000-0000-2

urn:issn:0167-6423

ftp://[email protected]

http://en.example.org/wiki/url

to be used as a general method for conceptual description or

modeling of information that is implemented in web resources, using a

variety of syntax formats

http://www.cars.com/car#A6

http://www.cars.com/car#Car

http://www.cars.com/car#Gasoline

http://www.cars.com/car#GDI

http://www.cars.com/car#Auto_8-Speed http://www.cars.com/car#Sedan

4

http://www.cars.com/car#AWD

115”

http://www.w3.org/1999/02/22-rdf-syntax-ns#type

http://www.cars.com/car#transmission

http://www.cars.com/car#wheelbase

http://www.cars.com/car#engine

http://www.cars.com/car#fuel

http://www.cars.com/car#drivetrain

http://www.cars.com/car#doors

http://www.cars.com/car#body_style

RDF Example

XML (Extensible Markup Language)

a markup language that defines a set of rules for encoding

documents in a format that is both human-readable and machine-

readable

<?xml version="1.0" encoding="utf-8"?>

<note>

<to>Tove</to>

<from>Jani</from>

<heading>Reminder</heading>

<body>Don't forget me this weekend!</body>

</note>

RDF/XML

an XML syntax for writing down and exchanging RDF graphs,

called RDF/XML

<?xml version="1.0"?>

<!DOCTYPE rdf:RDF [<!ENTITY xsd "http://www.w3.org/2001/XMLSchema#">]>

<rdf:RDF xmlns:rdf="http://www.w3.org/1999/02/22-rdf-syntax-ns#"

xmlns:car="http://www.cars.com/car#"

xml:base="http://www.cars.com/car">

<rdf:Description rdf:ID="A6">

<rdf:type rdf:resource="Car" />

<car:engine rdf:resource="GDI" />

<car:body_style rdf:resource="Sedan" />

<car:doors rdf:datatype="&xsd;int">4</car:doors>

...

</rdf:Description>

...

</rdf:RDF>

RDFS (RDF Schema)

a set of classes with certain properties using the RDF extensible

knowledge representation language, providing basic elements

for the description of ontologies, otherwise called RDF vocabularies,

intended to structure RDF resources

car:Car

car:Vehicle

rdfs:subClassOf

rdf:Property

car:body_style rdfs:domain

rdfs:range

rdfs:Class

rdf:type

rdf:type

car:Style

rdf:type

car:A6

rdf:type

car:Sedan rdf:type car:body_style

TBox - terminological component

ABox - assertion component

Ontology

knowledge representation as a set of concepts within a domain, and

the relationships between those concepts

formal, explicit specification of a shared conceptualisation

"Ontologies are often equated with taxonomic hierarchies of

classes, class definitions, and the subsumption relation, but

ontologies need not be limited to these forms. Ontologies are

also not limited to conservative definitions — that is,

definitions in the traditional logic sense that only introduce

terminology and do not add any knowledge about the world.

To specify a conceptualization, one needs to state axioms

that do constrain the possible interpretations for the defined

terms."

OWL (Web Ontology Language)

a family of knowledge representation languages for authoring

ontologies on the Semantic Web

Semantics of RDF, RDFS, and OWL

Each language for the Semantic Web provides a formal meaning

based on a model-theoretic semantics in its abstract syntax.

<x, y> is in IEXT(I(rdfs:subClassOf))

if and only if x and y are in IC

and ICEXT(x) is a subset of ICEXT(y)

car:Car

car:Vehicle

rdfs:subClassOf

car:A6

rdf:type

rdf:type

Language for the Rule Description

SWRL (Semantic Web Rule Language) is a proposal for a Semantic

Web rules-language, combining sublanguages of the OWL Web Ontology

Language (OWL DL and Lite) with those of the Rule Markup Language

(Unary/Binary Datalog).

<ruleml:imp>

<ruleml:_rlab ruleml:href="#example1"/>

<ruleml:_body>

<swrlx:individualPropertyAtom swrlx:property="hasParent">

<ruleml:var>x1</ruleml:var> <ruleml:var>x2</ruleml:var>

</swrlx:individualPropertyAtom>

<swrlx:individualPropertyAtom swrlx:property="hasBrother">



</ruleml:_body>

<ruleml:_head>

<swrlx:individualPropertyAtom swrlx:property="hasUncle">



</ruleml:_head>

</ruleml:imp>

hasParent(?x1,?x2) ∧ hasBrother(?x2,?x3) ⇒ hasUncle(?x1,?x3)

Inference

being able to derive new data from data that you already know

hasParent hasParent

hasWife

if hasParent(?x, ?y)

hasParent(?x, ?z)

Man(?y)

Woman(?z)

then hasWife(?y, ?z)

SPARQL

an RDF query language, that is able to retrieve and manipulate data

stored in Resource Description Framework format

PREFIX foaf: <http://xmlns.com/foaf/0.1/>

SELECT ?name ?email

WHERE {

?person a foaf:Person.

?person foaf:name ?name.

?person foaf:mbox ?email.

}

Agenda

• World Wide Web

• Semantic Web

Semantic Web Tools and Applications



• Open Government

Ontology Editor

Protégé

a free, open source ontology editor and knowledge-base framework

TopBraid Composer

a visual modeling environment from industry experts for creating and

managing domain models and ontologies in the Semantic Web standards

RDF, RDFS and OWL

OntoStudio

a professional developing environment of ontologies for ontologies and

rules with components for the integration of heterogeneous data sources

tools that provide complex development environments for Semantic Web applications, going

beyond a simple library for a programming language

TopBraid Composer

Class Panel Property Panel Editing Panel

Programming Environment

for the Semantic Web

Jena

a Java framework to construct Semantic Web Applications for RDF, RDFS

and OWL, SPARQL, GRDDL

OWL API

a Java interface and implementation for the W3C Web Ontology Language

OWL

Sesame

an open source RDF database with support for RDFS inferencing and

querying

tools that provide a working environment to develop Semantic Web applications in the forms

of application libraries, modules, etc

Triple Store

Jena

TDB which provides a lightweight, scalable non-transactional storage and

SDB which is a SPARQL database subsystem for Jena

OpenLink Virtuoso

a SQL-ORDBMS and Web Application Server hybrid (aka Universal Sever)

that provides SQL, XML, and RDF data management in a single

multithreaded server process

Oracle Spatial 11g

an open, scalable, secure and reliable RDF management platform based

on a graph data model

OWLIM

the most scalable semantic repository that includes triple store, inference

engine and SPARQL query engine

tools that can be installed to serve as RDF databases

OpenLink Virtuoso

SPARQL Endpoint tools that can be serve as SPARQL endpoints to large data sets

OpenLink Virtuoso

the Virtuoso SPARQL query service that implements the SPARQL Protocol

for RDF providing SPARQL query processing

Online Demo: http://demo.openlinksw.com/sparql/

Pubby

a Linked Data interface to local or remote SPARQL protocol servers

Most of triple stores support a interface for SPARQL.

Reasoner tools that can perform reasoning tasks, typically based on RDFS, OWL, or some rule engine

Jena, OWL API, OpenLink Virtuoso, Pellet, …

Most of programing environments and triple stores support reasoning

based on RDF, RDFS, and OWL semantics and rule.

RDB2RDF tools can be used to extract RDF data from a Relational Database, using either RDB2RDF

Direct Mapping or R2RML

D2RQ

a system for accessing relational databases as virtual, read-only RDF

graphs

Sponger

the Linked Data middleware component of Virtuoso that generates Linked

Data from a variety of data sources, supporting a wide variety of data

representation and serialization formats

online search engines specialized in OWL and/or RDF content, possibly including ontologies and vocabularies

Swoogle

a search engine for Semantic Web ontologies, documents, terms

and data published on the Web

Watson

web interface for searching ontologies and semantic documents using keywords

Naver Semantic Movie Search

Apple’s Siri

an intelligent personal assistant and knowledge navigator

which works as an application for Apple's iOS

a natural language user interface to answer questions, make

recommendations, and perform actions by delegating requests to a set of

Web services

How Siri Works Siri’s knowledge is

represented in a unified

modeling system that

combines ontologies,

inference networks, pattern

matching agents, dictionaries,

and dialog models. ... Siri isn’t

a source of data, so it doesn’t

expose data using Semantic

Web standards.

http://c2499022.cdn.cloudfiles.rackspacecloud.com/wp-content/uploads/2011/10/Siri-iPhone-4S-iOS-main.jpg

Google’s Semantic Search

They decided to call it

“Knowledge Graph”.

Knowledge Graph

a knowledge base used by Google to enhance its search engine's search

results with semantic-search information gathered from a wide

variety of sources

Agenda

• World Wide Web

• Semantic Web


Linking Open Data


• Open Government

Linking Open Data

a method of publishing structured data to share information in a

way that can be read automatically by computers based on standard Web

technologies such as HTTP and URIs

Components for LOD

• URIs (specifically, of the dereferenceable variety)

• HTTP

• Resource Description Framework (RDF)

• Serialization formats (RDFa, RDF/XML, N3, Turtle, and others)

Four Principles of Linked Data

1. Use URIs to identify things.

2. Use HTTP URIs so that these things can be referred to and looked up

("dereferenced") by people and user agents.

3. Provide useful information about the thing when its URI is

dereferenced, using standard formats such as RDF/XML.

4. Include links to other, related URIs in the exposed data to improve

discovery of other related information on the Web.

Linked Open Data star scheme

★ make your stuff available on the Web

(whatever format) under an open license

★★ make it available as structured data

(e.g., Excel instead of image scan of a table)

★★★ use non-proprietary formats

(e.g., CSV instead of Excel)

★★★★ use URIs to identify things, so that people can

point at your stuff

★★★★★ link your data to other data to provide context

http://lab.linkeddata.deri.ie/2010/star-scheme-by-example/

2007-11-10 2008-09-18

2009-07-14

2010-09-22

2011-09-19

DBPedia

a project aiming to extract structured content from the information

created as part of the Wikipedia project using the Resource

Description Framework (RDF) to represent the extracted

information

more than 3.64 million things, out of which 1.83 million are classified in

a consistent ontology

2,724,000 links to images and 6,300,000 links to external web pages

over 1 billion pieces of information (RDF triples)

//upload.wikimedia.org/wikipedia/commons/7/73/DBpediaLogo.svg

DBPedia Lookup Services

http://wiki.dbpedia.org/Lookup?v=18ln

Faceted Wikipedia Search based on DBPedia

http://dbpedia.neofonie.de/browse/

DBPedia Mobile

http://wiki.dbpedia.org/DBpediaMobile

Freebase

a large collaborative knowledge base consisting of metadata

composed mainly by its community members

Linked Data on BBC

Data from Wikipedia

Data from MusicBrainz

Best Buy with GoodRelations

<div class="vcard" typeof="gr:LocationOfSalesOrServiceProvisioning" about="#store_1796">

<div class="hours" rel="gr:hasOpeningHoursSpecification">

<li class="day0" typeof="gr:OpeningHoursSpecification" about="#storehours_sun">

<span rel="gr:hasOpeningHoursDayOfWeek" resource="http://purl.org/goodrelations/v1#Sunday" class="day">

<span property="gr:opens" datatype="xsd:time" content="11:00:00" class="open">

...

Agenda

• World Wide Web

• Semantic Web



Social Semantic Web

• Open Government

Social Semantic Web

a Web of collective knowledge

systems, which are able to provide

useful information based on

human contributions and which

get better as more people

participate

Syntax Semantic

World Wide Web URIs, HTML, HTTP

Semantic Web RDFS, OWL, SPARQL

Social Web Wikis, blogs, social networks

Social

Semantic Web SIOC, DBpedia, Twine

Vocabularies for SSW

FOAF (Friend of a friend)

a phrase used to refer to someone that one does not know well, literally, a

friend of a friend

SIOC (Semantically-Interlinked Online Communities)

methods for interconnecting discussion methods such as blogs, forums

and mailing lists to each other

SKOS (Simple Knowledge Organization System)

formal languages designed for representation of thesauri, classification

schemes, taxonomies, subject-heading systems, or any other type of

structured controlled vocabulary

MOAT (Meaning Of A Tag)

a Semantic Web framework to publish semantically-enriched content from

free-tagging one

Facebook’s Open Graph Protocol

simple protocol for enabling any web page to become a rich object in a social graph

Myungjin Lee

is a friend of

is a friend of

is a friend of

is a friend of

like

watch

watch

cook

like

http://a2.twimg.com/profile_images/508181218/disney_1.jpg

In 2010, we extended the social graph, via the

Open Graph protocol, to include 3rd party web

sites and pages that people liked throughout

the web. We are now extending the Open Graph

to include arbitrary actions and objects created

by 3rd party apps and enabling these apps to

integrate deeply into the Facebook experience.

Myungjin Lee

cook

http://example.com/cookie.html

Social Object

http://www.facebook.com/mjinlee

http://example.com/cookie.html

http://samples.ogp.me/Recipe

Stuffed Cookies

me:cook rdf:type

http://example.com/zhen/cookie.jpg

The Turducken of Cookies

http://example.com/zhen/cookie.html

og:title

og:image

og:description og:url

http://a2.twimg.com/profile_images/508181218/disney_1.jpg

Twitter Annotations

to add one or more annotations that represent structured metadata

about the tweet

How to make Annotations on your tweets

First element is a type.

Every Annotations has a type.

Type maps to attribute and value pair.

Second element is one or more attribute names with values.

http://r.github.com/annotationsformatter/

Agenda

• World Wide Web

• Semantic Web




Open Government

Open Government Data

By “open”, “open” data is free for

anyone to use, re-use and re-

distribute.

By “government data” we mean data

and information produced or

commissioned by government or

government controlled entities.

Open

Gov Data

Open

Data

Open

Gov

Data

Gov

Open

Gov

Data

Publishing Open Government Data

Step 1: The quickest and easiest way to make data available on the

Internet is to publish the data in its raw form (e.g., an XML file of polling

data from past elections). However, the data should be well-structured like

XML, RDF and CSV.

Step 2: Create an online catalog of the raw data so people can discover

what has been posted.

Step 3: Make the data both human- and machine-readable:

• enrich your resources with semantics, metadata, and identifiers;

• encode the data using open and industry standards - especially XML

- or create your own standards based on your vocabulary;

• make your data human-readable by either converting to (X)HTML,

or by using real-time transformations through CSS or XSLT.

• use permanent patterned and/or discoverable "Cool URIs";

• allow for electronic citations in the form of standardized hyperlinks.

Data.gov (the United States Government)

Data.gov.uk (HM Government)

A Timeline of Open Government Data

Data-Gov Wiki

a project for investigating open government datasets using semantic web

technologies

http://data-gov.tw.rpi.edu/wiki/The_Data-gov_Wiki

Clean Air Status and Trends - Ozone

Code for America

a non-partisan, non-political 501(c)3 organization founded in

2009 to bring web-industry professionals to work with city governments

in the United States in order to promote openness, participation,

and efficiency in municipal governments

http://codeforamerica.org/

SolarCity

DataMarket

a privately held Icelandic company that specialises in providing access

to and visually displaying data from public and, to a lesser extent,

private institutions and companies

Conte

nts

Searc

h o

n th

e S

em

antic

Web

Dr. Myungjin Lee

e-Mail : [email protected] Twitter : http://twitter.com/MyungjinLee

Facebook : http://www.facebook.com/mjinlee SlideShare : http://www.slideshare.net/onlyjiny/

http://iwec.yonsei.ac.kr:8080/iwb/

References http://www.w3.org/2001/sw/wiki/

http://www.wikipedia.org

http://www.slideshare.net/Cloud/the-social-semantic-web

http://www.slideshare.net/onlyjiny/social-semantic-web-on-facebook-open-graph-protocol-and-twitter-annotations

http://www.slideshare.net/onlyjiny/inference-on-the-semantic-web

http://www.novaspivack.com/technology/how-hisiri-works-interview-with-tom-gruber-cto-of-siri

http://linkeddata.org/

http://www.slideshare.net/HaklaeKim/open-government-data-linked-data-and-the-missing-blocks-in-korea

http://opengovernmentdata.org/

Semantic web

Technology

Transcript of Semantic web