This document discusses the Semantic Web and related technologies. It is comprised of several sections that describe key concepts such as the Semantic Web vision, Resource Description Framework (RDF), RDF Schema (RDFS), Web Ontology Language (OWL), and the Jena Semantic Web framework. The document provides examples and explanations of how these technologies relate to representing semantic data on the Web in a way that is accessible to machines.
Neno/Fhat: Semantic Network Programming Language and Virtual Machine Specific...Marko Rodriguez
• The Semantic Web is a distributed, flexible modeling framework.
• The Semantic Web is primarily descriptive in nature. The Semantic Web is used to describe web-pages, services, systems, etc.
• Neno is an object-oriented language that was designed specifically for the Semantic Web.
• Fhat is a virtual machine represented in the Semantic Web.
• With Neno/Fhat the Semantic Web now has a procedural component. The Semantic Web now includes object methods, algorithms, and computing machines.
• The Semantic Web can be made to behave like a distributed, general-purpose computer. Not just an information repository.
Neno/Fhat: Semantic Network Programming Language and Virtual Machine Specific...Marko Rodriguez
• The Semantic Web is a distributed, flexible modeling framework.
• The Semantic Web is primarily descriptive in nature. The Semantic Web is used to describe web-pages, services, systems, etc.
• Neno is an object-oriented language that was designed specifically for the Semantic Web.
• Fhat is a virtual machine represented in the Semantic Web.
• With Neno/Fhat the Semantic Web now has a procedural component. The Semantic Web now includes object methods, algorithms, and computing machines.
• The Semantic Web can be made to behave like a distributed, general-purpose computer. Not just an information repository.
Linked Open Data Libraries Archives Museums. This presentation is a basic overview of what LOD is and what technologies are needed to ensure the metadata around your collections is machine readable.
Development of Semantic Web based Disaster Management SystemNIT Durgapur
Semantic Web model In the field of disaster management to structurise the data such that any information needed during emergency will be easily available.
RDF is a general method to decompose knowledge into small pieces, with some rules about the semantics or meaning of those pieces. The point is to have a method so simple that it can express any fact, and yet so structured that computer applications can do useful things with knowledge expressed in RDF.
Open Knowledge Foundation Edinburgh meet-up #3Gill Hamilton
Lightning talks by
Gordon Dunsire on library standards and linked data
Gill Hamilton on recent initiatives with open and linked open data at National Library of Scotland
EC-WEB: Validator and Preview for the JobPosting Data Model of Schema.orgJindřich Mynarz
The presentation describes a tool for validating and previewing instances of Schema.org JobPosting described in structured data markup embedded in web pages. The validator and preview was developed to assist users of Schema.org to produce data of better quality. In this way, it tries to enhance usability of a part of Schema.org covering the domain of job postings. The paper discusses implementation of the tool and design of its validation rules based on SPARQL 1.1. Results of experimental validation of a job posting corpus harvested from the Web are presented. Among other findings, the results indicate that publishers of Schema.org JobPosting data often misunderstand precedence rules employed by markup parsers and that they ignore case-sensitivity of vocabulary names.
WebSpa is a tool that allows the quick, intuitive (and even fun) interrogation of arbitrary SPARQL endpoints. WebSpa runs in the web browser and does not require the installation of any additional software. The tool manages a large variety of pre-defined SPARQL endpoints and allows the addition of new ones. An user account gives the possibility of saving both the interrogation and its results on the local computer, as well as further editing of the queries. The application is written in both Java and Flex. It uses Jena and ARQ application programming interface in order to perform the queries, and the results are processed and displayed using Flex.
SDA2013 Pundit: Creating, Exploring and Consuming AnnotationsMarco Grassi
This paper presents Pundit, a novel semantic web annotation tool, and demonstrates its use in producing structured data out of users annotations. Pundit allows communities of scholars to produce machine-readable annotations that can be made public and thus consumable as web data via SPARQL and ad-hoc REST APIs.
Pundit is highly configurable and can deployed in custom instances to include well-defined and agreed annotation vocabularies. Such instances can be distributed as bookmaklets to community users so they can create uniformly structured data in a certain application scenario. Basing on the provided APIs, some demonstrative applications have been developed, exploring different use scenarios, ranging from philosophy to journalism and cultural heritage.
The main aim of this paper is to demonstrate how such uniformly structured annotations can be quickly re-used on the web to make information discoverable or to visualize it in interesting ways.
Understanding RDF: the Resource Description Framework in Context (1999)Dan Brickley
Dan Brickley, 3rd European Commission Metadata Workshop, Luxemburg, April 12th 1999
Understanding RDF: the Resource Description Framework in Context
http://ilrt.org/discovery/2001/01/understanding-rdf/
This tutorial explains the Data Web vision, some preliminary standards and technologies as well as some tools and technological building blocks developed by AKSW research group from Universität Leipzig.
Linked Open Data Libraries Archives Museums. This presentation is a basic overview of what LOD is and what technologies are needed to ensure the metadata around your collections is machine readable.
Development of Semantic Web based Disaster Management SystemNIT Durgapur
Semantic Web model In the field of disaster management to structurise the data such that any information needed during emergency will be easily available.
RDF is a general method to decompose knowledge into small pieces, with some rules about the semantics or meaning of those pieces. The point is to have a method so simple that it can express any fact, and yet so structured that computer applications can do useful things with knowledge expressed in RDF.
Open Knowledge Foundation Edinburgh meet-up #3Gill Hamilton
Lightning talks by
Gordon Dunsire on library standards and linked data
Gill Hamilton on recent initiatives with open and linked open data at National Library of Scotland
EC-WEB: Validator and Preview for the JobPosting Data Model of Schema.orgJindřich Mynarz
The presentation describes a tool for validating and previewing instances of Schema.org JobPosting described in structured data markup embedded in web pages. The validator and preview was developed to assist users of Schema.org to produce data of better quality. In this way, it tries to enhance usability of a part of Schema.org covering the domain of job postings. The paper discusses implementation of the tool and design of its validation rules based on SPARQL 1.1. Results of experimental validation of a job posting corpus harvested from the Web are presented. Among other findings, the results indicate that publishers of Schema.org JobPosting data often misunderstand precedence rules employed by markup parsers and that they ignore case-sensitivity of vocabulary names.
WebSpa is a tool that allows the quick, intuitive (and even fun) interrogation of arbitrary SPARQL endpoints. WebSpa runs in the web browser and does not require the installation of any additional software. The tool manages a large variety of pre-defined SPARQL endpoints and allows the addition of new ones. An user account gives the possibility of saving both the interrogation and its results on the local computer, as well as further editing of the queries. The application is written in both Java and Flex. It uses Jena and ARQ application programming interface in order to perform the queries, and the results are processed and displayed using Flex.
SDA2013 Pundit: Creating, Exploring and Consuming AnnotationsMarco Grassi
This paper presents Pundit, a novel semantic web annotation tool, and demonstrates its use in producing structured data out of users annotations. Pundit allows communities of scholars to produce machine-readable annotations that can be made public and thus consumable as web data via SPARQL and ad-hoc REST APIs.
Pundit is highly configurable and can deployed in custom instances to include well-defined and agreed annotation vocabularies. Such instances can be distributed as bookmaklets to community users so they can create uniformly structured data in a certain application scenario. Basing on the provided APIs, some demonstrative applications have been developed, exploring different use scenarios, ranging from philosophy to journalism and cultural heritage.
The main aim of this paper is to demonstrate how such uniformly structured annotations can be quickly re-used on the web to make information discoverable or to visualize it in interesting ways.
Understanding RDF: the Resource Description Framework in Context (1999)Dan Brickley
Dan Brickley, 3rd European Commission Metadata Workshop, Luxemburg, April 12th 1999
Understanding RDF: the Resource Description Framework in Context
http://ilrt.org/discovery/2001/01/understanding-rdf/
This tutorial explains the Data Web vision, some preliminary standards and technologies as well as some tools and technological building blocks developed by AKSW research group from Universität Leipzig.
Nelson Piedra , Janneth Chicaiza
and Jorge López, Universidad Técnica Particular de Loja, Edmundo
Tovar, Universidad Politécnica de Madrid,
and Oscar Martínez, Universitas
Miguel Hernández
Explore the advantages of using linked data with OERs.
Intelligent Expert systems can provide decisions for users for estimate from user preferences to find better destination from user profits. this present provides description of above system and suggest new approach for next researches.
Semantic - Based Querying Using Ontology in Relational Database of Library Ma...dannyijwest
The traditional Web stores huge amount of data in the form of Relational Databases (RDB) as it is good at
storing objects and relationships between them. Relational Databases are dynamic in nature which allows
bringing tables together helping user to search for related material across multiple tables. RDB are
scalable to expand as the data grows. The RDB uses a Structured Query Language called SQL to access
the databases for several data retrieval purposes. As the world is moving today from the Syntactic form to
Semantic form and the Web is also taking its new form of Semantic Web. The Structured Query of the RDB
on web can be a Semantic Query on Semantic Web.
Web of Data as a Solution for Interoperability. Case StudiesSabin Buraga
The paper draws several considerations regarding the use of Web of Data (Semantic Web) technologies – such as metadata vocabularies and ontological constructs – to increase the degree of interoperability within distributed systems. A number of case studies are presenting to express the knowledge in a
platform- and programming language-independent manner.
The Web of Linked Open Data, or LOD, is the most relevant achievement of the Semantic Web. Initially proposed by Tim Berners-Lee in a seminal paper published in Scientific American in 2001, the Semantic Web envisions a web where software agents can interact with large volumes of structured, easy to process data. It is now when users have at our disposal the first, mature results of this vision. Among them, and probably the most significant ones, are the different LOD initiatives and projects that publish open data in standard formats like RDF.
This presentation provides an overview and comparison of different LOD initiatives in the area of patent information, and analyses potential opportunities for building new information services based on largely available datasets of patent information. Information is based on different interviews conducted with innovation agents and on the analysis of professional bibliography and current implementations.
LOD opportunities are not only restricted to information aggregators, but also to end-users and innovation agents that need to face with the difficulties of dealing with large amounts of data. In both cases, the opportunities offered by LOD need to be assessed, as LOD has just become a standard, universal method to distribute, share and access data.
One day workshop Linked Data and Semantic WebVictor de Boer
As taught at UNIMAS July 2019. based on a three day summer school by Knud Hinnerk Moeller and Victor de Boer. Includes hands on excercises using SWI-Prolog ClioPatria
Indoor Positioning Using the OpenHPS FrameworkBeat Signer
Research paper presentation given at IPIN 2021, Lloret de Mar, Spain.
Hybrid positioning frameworks use various sensors and algorithms to enhance positioning through different types of fusion. The optimisation of the fusion process requires the testing of different algorithm parameters and optimal lowas well as high-level sensor fusion techniques. The presented OpenHPS open source hybrid positioning system is a modular framework managing individual nodes in a process network, which can be configured to support concrete positioning use cases or to adapt to specific technologies. This modularity allows developers to rapidly develop and optimise their positioning system while still providing them the flexibility to add their own algorithms. In this paper we discuss how a process network developed with OpenHPS can be used to realise a customisable indoor positioning solution with an offline and online stage, and how it can be adapted for high accuracy or low latency. For the demonstration and validation of our indoor positioning solution, we further compiled a publicly available dataset containing data from WLAN access points, BLE beacons as well as several trajectories that include IMU data.
Research paper: https://beatsigner.com/publications/indoor-positioning-using-the-openhps-framework.pdf
Personalised Learning Environments Based on Knowledge Graphs and the Zone of ...Beat Signer
Presentation given at CSEDU 2022, Virtual Event.
The learning of new knowledge and skills often requires previous knowledge, which can lead to some frustration if a teacher does not know a learner's exact knowledge and skills and therefore confronts them with exercises that are too difficult to solve. We present a solution to address this issue when teaching techniques and skills in the domain of table tennis, based on the concrete needs of trainers that we have investigated in a survey. We present a conceptual model for the representation of knowledge graphs as well as the level at which individual players already master parts of this knowledge graph. Our fine-grained model enables the automatic suggestion of optimal exercises in a player's so-called zone of proximal development, and our domain-specific application allows table tennis trainers to schedule their training sessions and exercises based on this rich information. In an initial evaluation of the resulting solution for personalised learning environments, we received positive and promising feedback from trainers. We are currently investigating how our approach and conceptual model can be generalised to some more traditional educational settings and how the personalised learning environment might be further improved based on the expressive concepts of the presented model.
Research paper: https://beatsigner.com/publications/personalised-learning-environments-based-on-knowledge-graphs-and-the-zone-of-proximal-development.pdf
Cross-Media Technologies and Applications - Future Directions for Personal In...Beat Signer
Webinar given at icity Lab Talks - The Digital Value Chain
In this talk, I will first provide an overview of the lab’s research on a general data-driven approach for cross-media information system and architectures based on the resource-selector-link (RSL) hypermedia metamodel. We will then have a look at several cross-media applications for personal information management and next-generation presentation solutions (MindXpres). Finally, I will outline the lab’s most recent research on tangible interaction and dynamic data physicalisation.
Codeschool in a Box: A Low-Barrier Approach to Packaging Programming CurriculaBeat Signer
Presentation given at CSEDU 2023, Prague, Czech Republic.
The tech industry is a fast-growing field, with many companies facing issues in finding skilled workers to fill their open vacancies. At the same time, many people have limited access to the quality education necessary to enter this job market. To address this issue, various small and often volunteer-run non-profit organisations have emerged to up-skill capable learners. However, these organisations face tight constraints and many challenges while trying to design and deliver high-quality education to their learners. In this position paper, we discuss some of these challenges and present a preliminary version of a curriculum packager addressing some of these issues. Our proposed solution, inspired by first-hand experience in these organisations as well as computing education research (CER), is based on a combination of micromaterials, study lenses and a companion mobile application. While our solution is designed for the specific context of small organisations providing vocational ICT training, it can also be applied to the broader domain of learning environments facing similar constraints.
Research paper: https://beatsigner.com/publications/codeschool-in-a-box-a-low-barrier-approach-to-packaging-programming-curricula.pdf
Towards a Framework for Dynamic Data PhysicalisationBeat Signer
Presentation given at the International Workshop Toward a Design Language for Data Physicalization, Berlin, Germany, October 2018
ABSTRACT: Advanced data visualisation techniques enable the exploration and analysis of large datasets. Recently, there is the emerging field of data physicalisation, where data is represented in physical space (e.g. via physical models) and can no longer only be explored visually, but also by making use of other senses such as touch. Most existing data physicalisation solutions are static and cannot be dynamically updated based on a user's interaction. Our goal is to develop a framework for new forms of dynamic data physicalisation in order to support an interactive exploration and analysis of datasets. Based on a study of the design space for dynamic data physicalisation, we are therefore working on a grammar for representing the fundamental physical operations and interactions that can be applied to the underlying data. Our envisioned extensible data physicalisation framework will enable the rapid prototyping of dynamic data physicalisations and thereby support researchers who want to experiment with new combinations of physical variables or output devices for dynamic data physicalisation as well as designers and application developers who are interested in the development of innovative dynamic data physicalisation solutions.
Paper: https://www.academia.edu/37336859/Towards_a_Framework_for_Dynamic_Data_Physicalisation
A workshop hosted by the South African Journal of Science aimed at postgraduate students and early career researchers with little or no experience in writing and publishing journal articles.
Normal Labour/ Stages of Labour/ Mechanism of LabourWasim Ak
Normal labor is also termed spontaneous labor, defined as the natural physiological process through which the fetus, placenta, and membranes are expelled from the uterus through the birth canal at term (37 to 42 weeks
June 3, 2024 Anti-Semitism Letter Sent to MIT President Kornbluth and MIT Cor...Levi Shapiro
Letter from the Congress of the United States regarding Anti-Semitism sent June 3rd to MIT President Sally Kornbluth, MIT Corp Chair, Mark Gorenberg
Dear Dr. Kornbluth and Mr. Gorenberg,
The US House of Representatives is deeply concerned by ongoing and pervasive acts of antisemitic
harassment and intimidation at the Massachusetts Institute of Technology (MIT). Failing to act decisively to ensure a safe learning environment for all students would be a grave dereliction of your responsibilities as President of MIT and Chair of the MIT Corporation.
This Congress will not stand idly by and allow an environment hostile to Jewish students to persist. The House believes that your institution is in violation of Title VI of the Civil Rights Act, and the inability or
unwillingness to rectify this violation through action requires accountability.
Postsecondary education is a unique opportunity for students to learn and have their ideas and beliefs challenged. However, universities receiving hundreds of millions of federal funds annually have denied
students that opportunity and have been hijacked to become venues for the promotion of terrorism, antisemitic harassment and intimidation, unlawful encampments, and in some cases, assaults and riots.
The House of Representatives will not countenance the use of federal funds to indoctrinate students into hateful, antisemitic, anti-American supporters of terrorism. Investigations into campus antisemitism by the Committee on Education and the Workforce and the Committee on Ways and Means have been expanded into a Congress-wide probe across all relevant jurisdictions to address this national crisis. The undersigned Committees will conduct oversight into the use of federal funds at MIT and its learning environment under authorities granted to each Committee.
• The Committee on Education and the Workforce has been investigating your institution since December 7, 2023. The Committee has broad jurisdiction over postsecondary education, including its compliance with Title VI of the Civil Rights Act, campus safety concerns over disruptions to the learning environment, and the awarding of federal student aid under the Higher Education Act.
• The Committee on Oversight and Accountability is investigating the sources of funding and other support flowing to groups espousing pro-Hamas propaganda and engaged in antisemitic harassment and intimidation of students. The Committee on Oversight and Accountability is the principal oversight committee of the US House of Representatives and has broad authority to investigate “any matter” at “any time” under House Rule X.
• The Committee on Ways and Means has been investigating several universities since November 15, 2023, when the Committee held a hearing entitled From Ivory Towers to Dark Corners: Investigating the Nexus Between Antisemitism, Tax-Exempt Universities, and Terror Financing. The Committee followed the hearing with letters to those institutions on January 10, 202
Biological screening of herbal drugs: Introduction and Need for
Phyto-Pharmacological Screening, New Strategies for evaluating
Natural Products, In vitro evaluation techniques for Antioxidants, Antimicrobial and Anticancer drugs. In vivo evaluation techniques
for Anti-inflammatory, Antiulcer, Anticancer, Wound healing, Antidiabetic, Hepatoprotective, Cardio protective, Diuretics and
Antifertility, Toxicity studies as per OECD guidelines
How to Make a Field invisible in Odoo 17Celine George
It is possible to hide or invisible some fields in odoo. Commonly using “invisible” attribute in the field definition to invisible the fields. This slide will show how to make a field invisible in odoo 17.
Introduction to AI for Nonprofits with Tapp NetworkTechSoup
Dive into the world of AI! Experts Jon Hill and Tareq Monaur will guide you through AI's role in enhancing nonprofit websites and basic marketing strategies, making it easy to understand and apply.
Operation “Blue Star” is the only event in the history of Independent India where the state went into war with its own people. Even after about 40 years it is not clear if it was culmination of states anger over people of the region, a political game of power or start of dictatorial chapter in the democratic setup.
The people of Punjab felt alienated from main stream due to denial of their just demands during a long democratic struggle since independence. As it happen all over the word, it led to militant struggle with great loss of lives of military, police and civilian personnel. Killing of Indira Gandhi and massacre of innocent Sikhs in Delhi and other India cities was also associated with this movement.
Exploiting Artificial Intelligence for Empowering Researchers and Faculty, In...Dr. Vinod Kumar Kanvaria
Exploiting Artificial Intelligence for Empowering Researchers and Faculty,
International FDP on Fundamentals of Research in Social Sciences
at Integral University, Lucknow, 06.06.2024
By Dr. Vinod Kumar Kanvaria
Natural birth techniques - Mrs.Akanksha Trivedi Rama University
Semantic Web - Lecture 09 - Web Information Systems (4011474FNR)
1. 2 December 2005
Web Information Systems
Semantic Web
Prof. Beat Signer
Department of Computer Science
Vrije Universiteit Brussel
http://www.beatsigner.com
2. November 28, 2014 Beat Signer - Department of Computer Science - bsigner@vub.ac.be 2
The Semantic Web
I have a dream for the Web [in which com-puters]
become capable of analyzing all the
data on the Web – the content, links, and
transactions between people and computers.
A 'Semantic Web', which should make this
possible, has yet to emerge, but when it
does, the day-to-day mechanisms of trade,
bureaucracy and our daily lives will be
handled by machines talking to machines.
The 'intelligent agents' people have touted
for ages will finally materialize.
Weaving the Web - The Original Design and Ultimate Destiny of the World Wide Web by Its Inventor,
Tim Berners-Lee, Harper San Francisco, September 1999
Tim Berners-Lee
3. November 28, 2014 Beat Signer - Department of Computer Science - bsigner@vub.ac.be 3
The Semantic Web ...
The Semantic Web is a vision: the idea of having data on
the Web defined and linked in a way that it can be used by
machines not just for display purposes, but for auto-mation,
integration and reuse of data across various
applications. Metadata provides a means to make
statements and create machine-readable statements.
W3C, 2003
4. November 28, 2014 Beat Signer - Department of Computer Science - bsigner@vub.ac.be 4
The Semantic Web ...
Meaning of data on the Web can not only be infered by
people but also discovered by machines without (or with
less) human intervention
Web of Data instead of Web of Documents
the Web as a huge decentralised database (knowledge base)
machine-accessible data
data may be interconnected similar to today's webpages
machine-readable metadata for existing web content
combination of data from different sources to derive new facts
machines (agents) may use logical reasoning to infer facts that
are not explicitly recorded
Crucial component of Web 3.0 or Giant Global Graph
5. November 28, 2014 Beat Signer - Department of Computer Science - bsigner@vub.ac.be 5
Video: The Future Internet
6. November 28, 2014 Beat Signer - Department of Computer Science - bsigner@vub.ac.be 6
Semantic Web Stack
The Semantic Web Stack
(or Semantic Web Cake)
describes the architecture
of the Semantic Web
URI/IRI
- unique identification of semantic
web resources
Unicode
- representing/manipulating text
in different languages
XML
- interchange of structured data
over the Web
Character set: UNICODE
Cryptography
Syntax: XML and XML Namespaces
Data interchange: RDF
Taxonomies: RDFS
Ontologies:
Querying: OWL
SPARQL
Unifying Logic
Trust
User interface and applications
Proof
Rules:
RIF/SWRL
Based on [http://en.wikipedia.org/wiki/File:Semantic-web-stack.png]
Identifiers:
URI/IRI
7. November 28, 2014 Beat Signer - Department of Computer Science - bsigner@vub.ac.be 7
Semantic Web Stack ...
XML Namespaces
- uniquely qualify markup from
multiple sources (integration)
Resource Description
Framework (RDF)
- define RDF triples and repre-sent
resource information in
a graph structure
RDF Schema (RDFS)
- create hierarchies of classes
and properties
Character set: UNICODE
Cryptography
Syntax: XML and XML Namespaces
Data interchange: RDF
Taxonomies: RDFS
Ontologies:
Querying: OWL
SPARQL
Unifying Logic
Trust
User interface and applications
Proof
Rules:
RIF/SWRL
Based on [http://en.wikipedia.org/wiki/File:Semantic-web-stack.png]
Identifiers:
URI/IRI
8. November 28, 2014 Beat Signer - Department of Computer Science - bsigner@vub.ac.be 8
Semantic Web Stack ...
Web Ontology Language
(OWL)
- language to define vocabularies
- extends RDFS with more ad-vanced
features (e.g. cardinality)
- enables reasoning based on
description logic
SPARQL
- query language to query any
RDF-based data
Rule Interchange Format
(RIF) and Semantic Web
Rule Language (SWRL)
- describe relations that cannot be
described in OWL
Character set: UNICODE
Cryptography
Syntax: XML and XML Namespaces
Data interchange: RDF
Taxonomies: RDFS
Ontologies:
Querying: OWL
SPARQL
Unifying Logic
Trust
User interface and applications
Proof
Rules:
RIF/SWRL
Based on [http://en.wikipedia.org/wiki/File:Semantic-web-stack.png]
Identifiers:
URI/IRI
9. November 28, 2014 Beat Signer - Department of Computer Science - bsigner@vub.ac.be 9
Semantic Web Stack ...
Unifying Logic
- logical reasoning (infer new
facts and check consistency)
Proof
- explain logical reasoning steps
Cryptography
- protect RDF data via encryption
- validate the source of facts by
digitally signing RDF data
Trust
- authentification of sources and
trustworthiness of derived facts
User Interface
- user interfaces for semantic web
applications
Character set: UNICODE
Cryptography
Syntax: XML and XML Namespaces
Data interchange: RDF
Taxonomies: RDFS
Ontologies:
Querying: OWL
SPARQL
Unifying Logic
Trust
User interface and applications
Proof
Rules:
RIF/SWRL
Based on [http://en.wikipedia.org/wiki/File:Semantic-web-stack.png]
Identifiers:
URI/IRI
10. November 28, 2014 Beat Signer - Department of Computer Science - bsigner@vub.ac.be 10
Resource Description Framework
The Resource Description Framework (RDF) has
been designed to describe
data and metadata about specific subjects
structure of data sets
relationships between bits of data
An RDF statement (triple) consists of three parts
subject
predicate (property)
object (value)
{person-1, name, "Niklaus Wirth"}
subject predicate object
11. November 28, 2014 Beat Signer - Department of Computer Science - bsigner@vub.ac.be 11
Resource Description Framework ...
Subjects, predicates and objects are all resources
Resource
anything that can be referenced by a URI
Literal
non-structured data (e.g. String, Integer, ...); is also a resource
a literal cannot be the subject of an RDF statement
Predicate
relation between two resources or between a resource and a
literal
RDF data is often stored in relational databases or so-called
triplestores (e.g. Apache Jena)
up to billions of triples
12. November 28, 2014 Beat Signer - Department of Computer Science - bsigner@vub.ac.be 12
RDF Graph
A set of RDF statements can be represented as a
directed labelled graph
note that in RDF we can only define statements about specific
instances but not about generic concepts
- ontologies have to be used to define statements about generic concepts
Beat
Signer
hasFamilyName
hasGivenName
http://wise.vub.ac.be/beat-signer
13. November 28, 2014 Beat Signer - Department of Computer Science - bsigner@vub.ac.be 13
RDF Graph ...
Anonymous resources have no explicit identifier
in the example, the "office" is an anonymous resource
anonymous resources are also called blank nodes or bnodes
blank nodes can only be used as subjects or objects
Beat Signer
hasGivenName hasFamilyName
http://wise.vub.ac.be hasDirector
http://wise.vub.ac.be/beat-signer
isMember
Lode
http://wise.vub.ac.be/lode-hoste
Hoste
hasFamily
Name
hasGivenName
isColleague
hasOffice
10F733 026293306
room phone
14. November 28, 2014 Beat Signer - Department of Computer Science - bsigner@vub.ac.be 14
RDF Reification
An RDF triple is not a resource and can therefore not
become subject of another statement
we have to reify the original statement
- make a resource out of the statement
Beat Signer
hasGivenName hasFamilyName
http://wise.vub.ac.be hasDirector
http://wise.vub.ac.be/beat/
isMember
Lode
http://wise.vub.ac.be/lode/
Hoste
hasGivenName
rdf:subject rdf:object
rdf:statement isColleague
rdf:type
rdf:Property
1
forYears
hasFamily
Name
15. November 28, 2014 Beat Signer - Department of Computer Science - bsigner@vub.ac.be 15
RDF Container Nodes
Special container resource types
bag
- number of unordered resources with potential duplicates
sequence
- ordered collection of resources
alternative
- one of the members can be selected
collection
- closed; once it has been defined, the
members can no longer be changed
http://wise.vub.ac.be/beat-signer
wearsShirt
http://shirt.org/shirt1
http://shirt.og/shirt2
RDF:_2
rdf:alternative
16. November 28, 2014 Beat Signer - Department of Computer Science - bsigner@vub.ac.be 16
Advantages of RDF
Simple
Enables the combination (merging) of data from
different data models
not easily possible in a relational database (different schemas)
The same resource can be annotated by different people
resource referenced by URI
separation of data and metadata
Well-defined standard
many tools available
- triplestores, parsers, editors, frameworks, ...
17. November 28, 2014 Beat Signer - Department of Computer Science - bsigner@vub.ac.be 17
RDF Schema (RDFS)
Vocabulary description language for RDF
domain vocabulary and structure
Define common concepts and relationships
classes (rdfs:Class) and subclasses (rdfs:subClassOf)
properties and sub-properties (rdfs:subPropertyOf)
domain (rdfs:domain) and range (rdfs:range) of a property
rdfs:seeAlso, rdfs:isDefinedBy (utility properties)
rdfs:label, rdfs:comment
...
Provides the basic elements for the definition of
ontologies
18. November 28, 2014 Beat Signer - Department of Computer Science - bsigner@vub.ac.be 18
RDF Schema Example
Beat Signer
hasGivenName hasFamilyName
Researcher
http://wise.vub.ac.be/beat-signer
Lode
http://wise.vub.ac.be/lode-hoste
Hoste
isColleague
hasGivenName hasFamilyName
rdf:type rdf:type
Person isColleague
rdfs:Class rdf:Property
rdf:type rdf:type rdfs:domain
rdfs:range
rdfs:subClassOf
rdfs:Literal rdfs:Literal rdfs:Literal rdfs:Literal
rdf:type rdf:type rdf:type rdf:type
19. November 28, 2014 Beat Signer - Department of Computer Science - bsigner@vub.ac.be 19
Advantages of RDFS
With RDFS we have a richer expressiveness
(e.g. subClassOf) than with RDF
Simple reasoning (e.g. type hierarchy)
Many existing tools to deal with RDFS
However, some things cannot be expressed; for example
"a person must have a family name"
"a person can have at most one family name" (cardinality)
"if Beat is a colleague of Lode then Lode is a colleague of Beat"
(transitivity)
these issues are addressed by the Web Ontology
Language (OWL)
20. November 28, 2014 Beat Signer - Department of Computer Science - bsigner@vub.ac.be 20
RDF(S) / XML Serialisation
Syntax not so easy to learn
many different ways to construct the same statement
long URIs are hard to read
{http://wise.vub.ac.be/beat-signer, isColleague,
http://wise.vub.ac.be/lode-hoste}
<rdf:RDF xmlns:rdf="http://www.w3.org/1999/02/22-rdf-syntax-ns#">
<rdf:Description rdf:about="http://wise.vub.ac.be/beat-signer">
<isColleague rdf:resource="http://wise.vub.ac.be/lode-hoste"/>
<hasGivenName>Beat</hasGivenName>
...
</rdf:Description>
...
</rdf:RDF>
21. November 28, 2014 Beat Signer - Department of Computer Science - bsigner@vub.ac.be 21
RDF Notation 3 (N3)
Short non-XML serialisation
separate predicates with a semicollon
finish subject definition with a full stop
Note that the N3 notation offers more features than are
necessary for RDF(S) serialisation
e.g. support for RDF-based rules
<http://wise.vub.ac.be/beat-signer> isColleague <http://wise.vub.ac.be/lode-hoste>;
...
hasGivenName "Beat".
22. November 28, 2014 Beat Signer - Department of Computer Science - bsigner@vub.ac.be 22
RDF Turtle Notation
Terse RDF Triple Language
Subset of N3 language
only describes RDF features (RDF graph model)
Syntax looks similar to Notation 3
http://www.w3.org/TeamSubmission/turtle/
Many RDF frameworks (e.g. Jena) offer Turtle parser
and serialisation features
23. November 28, 2014 Beat Signer - Department of Computer Science - bsigner@vub.ac.be 23
RDF Applications
Annotea project
defines an RDF schema for the types of annotations that can be
used to annote webpages
RSS
some RSS versions use RDF(S) / XML serialisation
Dublin Core
widely used to describe digital media (also in standard HTML)
- bibliographic metadata such a title, creator, description, ...
uses RDF(S) / XML serialisation as one possible representation
<head>
...
<meta name="DC.Subject" content="Interactive Paper, Cross-media ..."/>
<meta name="DC.Description" content="Beat Signer does research on ..."/>
</head>
24. November 28, 2014 Beat Signer - Department of Computer Science - bsigner@vub.ac.be 24
SPARQL Query Language
RDF query language which can be used to
extract information as URIs, literals, blank nodes or subgraphs
SPARQL SELECT queries return variable bindings
SPARQL querying relies on graph pattern matching
Example
get the name and mbox of all subjects that have both of these
properties defined
SELECT ?name ?mbox
WHERE { ?x foaf:name ?name .
?x foaf:mbox ?mbox }
25. November 28, 2014 Beat Signer - Department of Computer Science - bsigner@vub.ac.be 25
Web Ontology Language (OWL)
OWL evolved from DAML+OIL
DAML is the DARPA Agent Markup Language
OIL stands for Ontology Inference Layer
There exist 3 different OWL sublanguages (flavours) with
different expressivness
OWL Full
- maximum expressiveness (full language)
- no computational guarantee
OWL DL
- maximal OWL Full subset that is still computationally decidable
OWL Lite
- classification hierarchy and simple constraints (limited cardinality constraints)
- weakest of the three variants
26. November 28, 2014 Beat Signer - Department of Computer Science - bsigner@vub.ac.be 26
Jena Semantic Web Framework
Open source Semantic Web framework for Java
create and access data from RDF graphs via an RDF API
offers an OWL API
data can be stored in files, databases or accessed via URLs
http://jena.sourceforge.net
RDF graphs can be serialised into different formats
RDF/XML
Notation 3
Turtle
relational database
SPARQL query interface
Multiple reasoners
27. November 28, 2014 Beat Signer - Department of Computer Science - bsigner@vub.ac.be 27
Protégé
Free open source platform
to create, manipulate and
visualise ontologies
Two modelling tools
Protégé-Frames editor
- build and populate frame-based
ontologies
- Java API for plug-ins
Protégé-OWL editor
- build Semantic Web ontologies
28. November 28, 2014 Beat Signer - Department of Computer Science - bsigner@vub.ac.be 28
Swoogle
Search engine for seman-tic
web data (RDF)
ontologies
instance data
single terms
Ranking of semantic web
documents
inspired by Google's
PageRank
Developed at the
University of Maryland
http://swoogle.umbc.edu
29. November 28, 2014 Beat Signer - Department of Computer Science - bsigner@vub.ac.be 29
Friend of a Friend (FOAF)
Personal information and connections to friends in RDF
http://www.foaf-project.org
<rdf:RDF xmlns:rdf="http://www.w3.org/1999/02/22-rdf-syntax-ns#"
xmlns:rdfs="http://www.w3.org/2000/01/rdf-schema#" xmlns:foaf="http://xmlns.com/foaf/0.1/">
<foaf:Person>
<foaf:name>Beat Signer</foaf:name>
<foaf:title>Prof.</foaf:title>
<foaf:givenname>Beat</foaf:givenname>
<foaf:family_name>Signer</foaf:family_name>
<foaf:nick>Beat</foaf:nick>
<foaf:mbox_sha1sum>ce6d419869307d57839feef6445a9d64f784eb36</foaf:mbox_sha1sum>
...
<foaf:knows>
<foaf:Person>
<foaf:name>Moira C. Norrie</foaf:name>
<foaf:mbox_sha1sum>4cb61b36a6feaa48c78acbb51fcce7cb356afdd6</foaf:mbox_sha1sum>
<rdfs:seeAlso rdf:resource="http://www.globis.ethz.ch/people/norrie.rdf">
</foaf:Person>
</foaf:knows>
...
</foaf:Person>
</rdf:RDF>
30. November 28, 2014 Beat Signer - Department of Computer Science - bsigner@vub.ac.be 30
Friend of a Friend (FOAF) ...
First social Semantic Web
application
Miller and Brickley, 2000
Describe a social network
without a central database
links can be followed by
spiders (data mining)
no unique identifier
- identification by description
(pedicates and objects)
"six degrees of separation" or
"small world phenomenon"
FOAFNaut browser
[http://rdfweb.org/images/foaf/foafnaut-screenshot-path.jpg]
31. November 28, 2014 Beat Signer - Department of Computer Science - bsigner@vub.ac.be 31
Semantic Wikis
Use Semantic Web
technologies to provide
machine-processable
Wiki content
page content
link metadata
Ontology reasoning
much richer query interface
Existing semantic Wikis
DBPedia
Semantic MediaWiki
...
32. November 28, 2014 Beat Signer - Department of Computer Science - bsigner@vub.ac.be 32
Linked Data
Link different data sources (URIs) on the Web
provide metadata about the resources via RDF/XML, N3, etc.
provide links to resources in other data sets on the Web
Linked Open Data community project
RDF tripes from DBPedia, GeneID, ACM, etc. (>30 billion triples)
links between those triples (>500 million links)
http://lod-cloud.net/versions/2014-08-30/lod-cloud.svg
33. November 28, 2014 Beat Signer - Department of Computer Science - bsigner@vub.ac.be 33
Semantic Desktops
Apply Semantic Web tech-nologies
to personal infor-mation
management (PIM)
inter-application data sharing
enhancement of limited
filesystem functionality
- add document metadata
Examples
Haystack
Nepomuk
Nepomuk Integration with Dolphin (KDE 4.0)
34. November 28, 2014 Beat Signer - Department of Computer Science - bsigner@vub.ac.be 34
GoodRelations
Lightweight ontology for expressing
product information in e-commerce web applications
Product features
offers
prices
units
...
Adopted by various companies
Yahoo
BestBuy
...
Leads to enhanced product search functionality
35. November 28, 2014 Beat Signer - Department of Computer Science - bsigner@vub.ac.be 35
Microformats
Add semantics to (X)HTML pages
Makes use of specific (X)HTML tag attributes
class and rel attributes
- e.g. rel="nofollow" for search engines
Specific microformats
hCard: contact information
hCalendar: event information
hProduct: product information
Alternative solutions
semantic web (RDFa)
GRDDL
- Gleaning Resource Descriptions from Dialects of Language
- can convert from microformats to semantic web data (RDF)
36. November 28, 2014 Beat Signer - Department of Computer Science - bsigner@vub.ac.be 36
hCard Microformat Example
Some search engines (e.g. Google and Yahoo) start to
pay attention to different types of microformats
<head profile="http://www.w3.org/2006/03/hcard">
...
</head>
...
<div class="vcard">
<div class="fn">Lode Hoste</div>
<div class="org">Vrije Universiteit Brussel</div>
<div class="tel">32 2629 3306</div>
<a class="url" href="http://wise.vub.ac.be/members/lode-hoste">
http://wise.vub.ac.be/members/lode-hoste</a>
</div>
37. November 28, 2014 Beat Signer - Department of Computer Science - bsigner@vub.ac.be 37
RDF in Attributes (RDFa)
Add a set of attribute extensions to XHTML for
embedding RDF metadata
Different vocabularies
FOAF, video, audio, commerce, …
Search engines (e.g. Yahoo and Google) process certain
RDFa metadata (e.g. product information)
<p xmlns:dc=http://purl.org/dc/elements/1.1/
about="http://www.amazon.com/...">
and the will to live. <span property="dc:creator">Simpson</span>
dedicates the book <cite property="dc:title">Touching the Void</cite> to
the... The book was published in <span property="dc:date"
content="1989-12-01">December 1989</span>.
</p>
38. November 28, 2014 Beat Signer - Department of Computer Science - bsigner@vub.ac.be 38
Microdata
Add machine readable metadata (semantics) to
HTML5 documents in the form of key/value pairs
can be used by crawlers, search engines (SEO) and browsers to
provide a richer browsing experience
alternative to Microformats and RDFa
W3C Working Draft
<section itemscope itemtype="http://data-vocabulary.org/Person">
Hello, my name is <span itemprop="name">Beat Signer</span> and I am a
<span itemprop="title">Professor</span> at the
<span itemprop="affiliation">Vrije Universiteit Brussel. </span>
<section itemprop="address" itemscope itemtype="http://data
-vocabulary.org/Address">My address is:
<span itemprop="street-address">Pleinlaan 2</span>,
<span itemprop="postal-code">1050 </span>
<span itemprop="locality">Brussels</span>,
<span itemprop="country-name">Belgium</span>.
</section>
</section>
39. November 28, 2014 Beat Signer - Department of Computer Science - bsigner@vub.ac.be 39
Exercise 9
Semantic Web
working with linked data
40. November 28, 2014 Beat Signer - Department of Computer Science - bsigner@vub.ac.be 40
References
Tim Berners-Lee, James Hendler and Ora
Lassila, The Semantic Web, Scientific American
Magazine, May 2001
http://www.scientificamerican.com/article.cfm?id=the-semantic-
web
The Future Internet: Service Web 3.0
http://www.youtube.com/watch?v=off08As3siM
Resource Description Framework (RDF)
http://www.w3.org/RDF/
Thomas B. Passin, Explorer's Guide to the Semantic
Web, Manning Publications, March 2004
41. November 28, 2014 Beat Signer - Department of Computer Science - bsigner@vub.ac.be 41
References ...
Linked Data
http://linkeddata.org