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Examples of using semantic web technologies in real world applications [closed]

Are you working on a (probably commercial) product which uses RDF/OWL/SPARQL technologies? If so, can you please describe your product?

The best tool for visualizing ontologies? [closed]

I am looking to visualize ontologies for understanding and making others understand. I would prefer to have top-down hierarchy of classes. I have used OntoGraph which comes with Protégé, but I am not happy with the figure :(. I have also used Microsoft Visio and stencils available for Ontology, but that too has not impressed me.

Through this question I would like to know which is the best tool for visualizing an ontology for general purpose, and/or for specific purpose (like writing an academic paper).

Thanks.

~Codera

Are there any tools to visualize a RDF graph? (please include a screenshot)

I'm looking for a tool that will render a RDF graph in a reasonably useful graphic format. The primary purpose of the graphic format being inclusion into a PowerPoint slide or printing on a large plotter for management review.

I am currently using TopBraid Composer which does a reasonably well at visualizing a single entity but doesn't seem to have a clear way of visualizing the entire graph (as a whole).

Anyone know of any good solutions to this problem?

What is the best way to learn about RDF / OWL? [closed]

What references offer a good summary/tutorial for using RDF/OWL? There seem to be enough tools (Protege, Topbraid, Jena, etc.) that knowing the syntax of the markup languages is not necessary, but knowing the concepts is, of course, still critical.

I'm working through the w3c documents (particularly the RDF Primer) but I'd like to find other resources/techniques to use as well.

Is there any killer application for Ontology/semantics/OWL/RDF yet? [closed]

I got interested in semantic technologies after reading a lot of books, blogs and articles on the net saying that it would make data machine-understandable, allow intelligent agents make great reasoning, automated & dynamic service composition etc..

I am still reading the same stuff from 2 years. The number of articles/blogs/semantic-conferences have increased considerably. But I am still unable to see any killer-application. Why is it so? Or is there some application/product (commercial/open-source) already existing, which actually is doing all that being boasted of?

To put it more precisely, is there any product that leverages semantic technologies (esp RDF/OWL/SPARQL) and is delivering functionality/performance/maintainability, which would not have been possible with the existing (no-semantic) technologies? Some product that is completely dependent on semantic technologies and really adds value to the customers and generating revenues?

What is the best PHP lib/class to generate RSS/Atom [closed]

I have to produce RSS/Atom feed in various applications, and I want to know a good lib/class wich is able to produce both, and which already handle all common problems.

For example the one I used for year does not put the right format for date, so my feed is not well handled by several aggregators.

Thanks, Cédric

Update : Why I am looking for a lib? Because the one I used for years, which I had hacked a few, have a little problem. Maybe a specification is not correctly followed. http://stackoverflow.com/questions/182615/why-my-rss-feed-duplicate-some-entries

Great RDF visualization tools [closed]

I want to find some great tools or styles to visualize my RDF data so that it can give viewers a shock when they access the RDF data.

The problem is that the visualization tools I get now can just generate some simple styles(node,edge...)like below:

They look ugly because edges take up too many spaces and nodes are too small.I don't think this kind of graphs can give viewers any different experiences from viewing sheets or tables directly.

I want to know if there are any new visualization tools or just styles that can give users really different experiences so that they can feel how invaluable linked data are...

Any suggestions or recommendations?

Rails application architecture to work with RDF storage

I need to make an application, that saves the data in the RDF storage for subsequent processing. I have several solutions and don't know what to choose:

1. Use classical application architecture with AR/Mongoid + RDF rendering + crawler, that agregates RDF data and saves it to the storage. It's comfortable, but I need to create a crawler and feed him data on every save.
2. Use spira ORM and save directly to the RDF storage. Here I don't need to write a crawler, but I need to make backend for auth plugin and to implement everything, that don't support spira.
3. Use classical architecture + additional spira models, so that I would have 2 model classes for each entity, ex: User in AR + UserSpira in Spira, where on save event of User Spira object is saved too.

What application architecture to choose? May be some other solutions?

Any configuration management software using RDF?

Do any configuration management software (such as Puppet, Chef, Pallet, SmartFrog, etc.), open or closed source, using RDF data model to describe and configure infrastructure and software running on it?

Alternatively, is there an RDF vocabulary or OWL ontology which could be useful in such domain?

Which Triplestore for rapid semantic web development?

Ease of installation/use is the most important factor here - not performance.

Small is OK as large datasets are not expected.

Parse large RDF in Python

I'd like to parse a very large (about 200MB) RDF file in python. Should I be using sax or some other library? I'd appreciate some very basic code that I can build on, say to retrieve a tag.

Thanks in advance.

exploratory SPARQL queries?

whenever i start using sql i tend to throw a couple of exploratory statements at the database in order to understand what is avaliable, and what form the data takes.

eg.

show tables

describe table

select * from table

could anyone help me understand the way to complete a similar exploration of an rdf datastore using a SPARQL endpoint?

Thanks :)

Differences between rdf:resource, rdf:about and rdf:ID

What are the conceptual differences between rdf:resource, rdf:about, and rdf:ID. I did some investigation but the difference between them are not clear for me yet. For example, whether rdf:ID is used when declaring a resource for the first time, rdf:resource is used for referencing an already existing resource, etc.

I would be glad if you provide some little examples.

Simple example of reification in RDF

Could anybody be so kind to give me a simple example of reification in RDF? I want to see if I understood it correctly.

For example, I propose the following case

Tolkien -> wrote -> Lord of the rings
           /|\
            |
        Wikipedia said that

How would you write it with and without reification (i.e. as a simple RDF statement with no need for reification)?

Difference between domain and range in rdf schema?

could you please explain me the difference between rdfs:domain and rdfs:range with an example? and when should i use domain and when range? i have read h w3c rdf primer but i did not understand the difference