Transcript Aplicații web semantice - Cursuri Automatica si Calculatoare
Semantic Web Applications Introduction Vlad Posea
• http://www.ted.com/talks/tim_berners_lee_o n_the_next_web.html
On the next web
• • • Web 1.0 = a way to reframe the way we use information Overcome the need for systems to be interoperable in order for people to better access each others’ documents => TBL was frustrated – => he built a system to overcome that – Great idea – linking documents - hypertext
Which is the problem that still frustrates people and TBL?
• • Turns out that there is still huge unlocked potential. There is still a huge frustration that people have because we haven't got data on the web as data.
Which is the difference between document and data?
– On the web we have links between documents not between data sets
Web evolution
• • • Web today “So, imagine that that link could have gone to virtually any document you could imagine.” Web of documents • • • Web tomorrow “but I want to think about a world where everybody has put data on the web and so virtually everything you can imagine is on the web. and then calling that linked data.” Web of data
how do we get to the next web?
• • those things that start with http: --we're using them not just for documents now,we're using them for things that the documents are about.
Web 1.0: • URLs – used to identify documents • Semantic web: • URIs – used to identify data (resources)
relations url that identifies a data resource
how do we get to the next web?
• TBL’s rules: – All kinds of conceptual things, they have names now that start with HTTP.
– I get important information back about the data I’m looking up using a standard format – when I get back that information it's got relationships
How do we create the semantic web
• write a program to take the data, extract it from Wikipedia, and put it into a blob of linked data on the web, which he called dbpedia.
How do we create the semantic web
• • write a program to take the data, extract it from Wikipedia, and put it into a blob of linked data on the web, which he called dbpedia.
American government data would be available on the Internet in accessible formats (england’s data already is)
How do we create the semantic web
• • • write a program to take the data, extract it from Wikipedia, and put it into a blob of linked data on the web, which he called dbpedia.
American government data would be available on the Internet in accessible formats (england’s data already is) data is about our lives. You just -- you log on to your social networking site, your favorite one, you say, "This is my friend." Bing! Relationship. Data. You say, "This photograph, it's about -- it depicts this person. "
How do we create the semantic data?
• • • Extract data from web sites and publish it in semantic formats When you develop a web site make sure the data is also available in semantic formats Fetch semantic data from social web sites
What is it good for?
• • Answer questions based on relations between different data concepts: – What proteins are involved in signal transduction and also related to pyramidal neurons?
– All soccer players, who played as goalkeeper for a club that has a stadium with more than 40.000 seats and who are born in a country with more than 10 million inhabitants (dbpedia example) Query the web like you would query a database!
Web 2.0 + Semantic Web
• • => Social Semantic Web social semantic web is all about everybody doing their bit and it creates an incredible resource because everybody else does theirs. And that is what linked data is all about. It's about people doing their bit to produce a little bit, and it all connecting.
What I want you to do
• Create linked data and make it available on the web – Choose a domain that you’re interested in – Make an ontology of the domain (linking it to existing ontologies) – Extract data from the web and create a semantic repository – Make the data available for search by other applications – Create a web application that uses the semantic data that you have
What others want you to do
• • • • • http://challenge.semanticweb.org
Challenge at the biggest international conference The requirements represent practically the guidelines for the development of the Semantic Web Minimal requirements – also needed for our project Additional Desirable Features – what you will actually need for a commercial product.
Minimal requirements
• • • • • • The application has to be an end-user application The information sources used – should be under diverse ownership or control – – should be heterogeneous (syntactically, structurally, and semantically) should contain substantial quantities of real world data The meaning of data has to play a central role.
Meaning must be represented using Semantic Web technologies.
Data must be manipulated/processed in interesting ways to derive useful information and this semantic information processing has to play a central role in achieving things that alternative technologies cannot do as well, or at all;
Additional Desirable Features
• •
The application provides an attractive and functional Web interface (for human users)
The application should be scalable (in terms of the amount of data used and in terms of distributed components working together). Ideally, the application should use all data that is currently published on the Semantic Web.
• •
Rigorous evaluations have taken place that demonstrate the benefits of semantic technologies, or validate the results obtained.
Novelty, in applying semantic technology to a domain or task that have not been considered before Italic=interesting from the research point of view
Bold = interesting from the commercial point of view
Additional Desirable Features
• • • • • •
Functionality is different from or goes beyond pure information retrieval The application has clear commercial potential and/or large existing user base
Contextual information is used for ratings or rankings
Multimedia documents are used in some way
There is a use of dynamic data (e.g. workflows), perhaps in combination with static information
The results should be as accurate as possible (e.g. use a ranking of results according to context)
• • • •
Examples: Semantic Web Challenge winners - 2010
NCBO Resource Index: Ontology-Based Search and Mining of Biomedical Resources – winner 2010 http://www.cs.vu.nl/~pmika/swc/submissions /swc2010_submission_4.pdf
Uses ontologies on BioPortal to annotate resources with concepts from the ontologies Semantics used in finding synonyms, autocomplete on search, identify hierarchies of concepts
• • •
Examples: Semantic Web Challenge winners - 2010
Linking Open Government Data http://logd.tw.rpi.edu/ http://www.cs.vu.nl/~pmika/swc/submissions /swc2010_submission_16.pdf
The TWC LOGD Portal is a semantic web application dedicated to publishing Linked Data versions of OGD and sharing tools, services and expertise supporting an OGD ecosystem. It serves data users ranging from informed citizens, to domain experts, to developers consuming and creating novel
• • •
Examples: Semantic Web Challenge winners - 2010
shortipedia.org http://www.cs.vu.nl/~pmika/swc/submissions /swc2010_submission_18.pdf
Aggregating semantic data + curating by volunteer users (just like wikipedia)
• • •
Examples: Semantic Web Challenge winners - 2009
http://www.cs.vu.nl/~pmika/swc/documents/ TrialX-healthx-iswc09-challenge.pdf
- matching patients with clinical trials based on patient records http://www.cs.vu.nl/~pmika/swc/documents/ VisiNav-paper.pdf
Exploration of web datasets http://www.cs.vu.nl/~pmika/swc/documents/ Sig.ma:%20Live%20views%20on%20the%20w eb%20of%20data-sigma.pdf
Visualisation of the web of data
• • •
Examples: Semantic Web Challenge winners - 2008
paggr.com – creates mashups from semantic data DBPediaMobile – integrates DBPedia data with Google Maps HealthFinland - single national entry-point for health information, health promotion and health-related news
Evolution of the domain
2008 2009 2010 Output data in semantic formats Aggregate data on a small scale Visualize data Develop tools Develop tools (visualisation) number of sources Aggregate data on a large scale Complex applications Aggregating data on that take advantage of larger scale from a small all the existing data and tools Evolution from development of tools, small applications, output of semantic data from a single domain to complex applications aggregating large number of data sources providing complex services
Example
• • • • Domain: Romanian Tourism Ontology concepts: Hotel, Resort, Activity, City, Camera,… Data sources: tourism web sites Semantic interogations – Hotel at least 2 stars where you can practice archery – Hostel in the Apuseni mountains with a place where the children can play – Hotel that the girlfriend would like:)
Nume: Rating (nr stele) Contact: foaf:Person Facilit ăți
How do you gain points
• • 5 points exam 5 points project – described in the previous slides
http://www.ted.com/talks/tim_berners_lee_the _year_open_data_went_worldwide.html
References
• • http://www.scientificamerican.com/article.cf
m?id=the-semantic-web http://www.ted.com/talks/tim_berners_lee_o n_the_next_web.html