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
the main markup language for
displaying web pages and other
information that can be displayed
in an web browser

HTML
Document

HTTP URI
an application protocol for a string of characters
distributed, collaborative,
Protocol Identifier used to identify a name
hypermedia information systems or a resource

HTML is used
to display web pages
for human.

Hyperlink in HTML is
a reference to document. <a href="http://en.wikipedia.org/wiki/Html">
HTML
</a>
<a href="http://en.wikipedia.org/wiki/World_Wide_Web">
Web
</a>
hyperlink

hyperlink

What is problem?
AutoTrader.com
Cars.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

Basic Concept for Data Description
on the Semantic Web

Gasoline

3.0L V6
AWD
24V GDI
fuel
engine
drivetrain
wheelbase
4 A6 115”
doors
transmission
body_style type
8-Speed
Sedan Automatic

Car

URI (Uniform Resource Identifier)

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

URI

URN
(Uniform Resource Name)
+ URL
(Uniform Resource Locator)

urn:isbn:0451450523 ftp://asmith@ftp.example.org
urn:isan:0000-0000-9E59-0000-O-0000-0000-2 http://en.example.org/wiki/url
urn:issn:0167-6423

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

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

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

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

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

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

4 http://www.cars.com/car#A6 115”

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

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

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

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

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

TBox - terminological component
rdf:type car:Vehicle rdf:Property

rdfs:Class rdfs:subClassOf rdf:type

rdf:type
car:Car car:body_style
rdfs:domain

rdf:type rdfs:range

car:A6 car:Sedan car:Style
car:body_style rdf:type

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.

car:Vehicle

rdfs:subClassOf

<x, y> is in IEXT(I(rdfs:subClassOf))
car:Car rdf:type
if and only if x and y are in IC
and ICEXT(x) is a subset of ICEXT(y) rdf:type

car:A6

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).

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

<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>

Inference

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

hasWife
if hasParent(?x, ?y)
hasParent(?x, ?z)
Man(?y)
hasParent hasParent
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
tools that provide complex development environments for Semantic Web applications, going
beyond a simple library for a programming language

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

TopBraid Composer

Class Panel
Editing Panel Property Panel

Programming Environment
for the Semantic Web
tools that provide a working environment to develop Semantic Web applications in the forms
of application libraries, modules, etc

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

Triple Store
tools that can be installed to serve as RDF databases

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

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

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.

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)

Faceted Wikipedia Search based on DBPedia

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

 Social Web Social
 Wikis, blogs, social networks Semantic Web
 SIOC, DBpedia, Twine

World Wide Web Semantic Web
 URIs, HTML, HTTP RDFS, OWL, SPARQL

Syntax Semantic

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

watch is a friend of

is a friend of

is a friend of

is a friend of

watch
Myungjin Lee

like
like

cook

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.

Social Object
cook

Myungjin Lee

http://example.com/cookie.html

http://www.facebook.com/mjinlee
http://samples.ogp.me/Recipe

me:cook
rdf:type
og:title Stuffed Cookies

http://example.com/cookie.html og:image
http://example.com/zhen/cookie.jpg

og:url
og:description
The Turducken of Cookies

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

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

Open By “open”, “open” data is free
for
anyone to use, re-use and re-
distribute.
Open Open
Data Open Gov
Gov By “government data” we mean data
Data
and information produced or
Data Gov
Data commissioned by government or
Gov government controlled entities.

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)

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/

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

Contents Search on the Semantic Web

Dr. Myungjin Lee
e-Mail : xml@yonsei.ac.kr
Twitter : http://twitter.com/MyungjinLee
Facebook : http://www.facebook.com/mjinlee
SlideShare : http://www.slideshare.net/onlyjiny/

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

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