I need to store RDF triples, while keeping track of modifications. Is there anything out there for this service? Alternatively, how would you keep track of revision while using a context-aware triplestore ? Edit: please note that I don't need only the changeset. I also need to see the triples at any time in the past. ...
I'm a firm believer in learning a platform or technology by playing with it. So I've kind of glanced at SPARQL and thus far haven't really gotten to into it because it just ... looks daunting (as does everything at first). I'd like an environment with a couple of documents that I can cross reference and query. My temptation is to do SQL...
I'm trying to convert last.fm xml data into rdf using xslt and am getting this error: ERROR [http-8080-1] (RDFDefaultErrorHandler.java:40) - (line 3 column 24): {E202} Expecting XML start or end element(s). String data "Joseph Arthur" not allowed. Maybe a striping error. Can anyone explain to me what a striping error is, or in general w...
I'd like to learn more about RDF/SPARQL implementation internals, but most of the frameworks are (necessarily) somewhat complicated by real-world performance and implementation consideratins. I am curious if there is a "reference" implementation that would be suitable as a low-level teaching tool? What is the RDF/SPARQL implementation t...
Hi, I am very new to working with semantic data and have a quick question that i cant find an answer to. When creating an rdf schema are you essentially creating a class as per OOP i.e. declaring all properties etc that are valid. If this is the case then say I want a property called 'title' which I actually intend on using dcterms:tit...
I'm setting up a tourism website and wish to use semantic web in it. I'm also interested in using RDF ontologies. So, I was wondering if anyone could tell me, if exists anything for this, that says "This Hotel is located in Foo" or "This Restaurant has a 3 points rating in the Foo community" or "This itinerary it's for three days and it...
I've been working to apply the hCalendar microformat to the events displayed on my web site. However, from my research, I get the impression that microformats are not recommended (or at least looked down upon by some). Instead, RDF seems to be the preferred way for representing semantic-rich information. However, I'm confounded by RDF...
I would like to store my personal data in a FOAF file on my own server. There is a group of us doing the same thing. We need a couple of custom fields that the standard FOAF implementation doesn't have, ie: availability. How can I add the availability field, and still keep the FOAF file validated? I guess I use the RDF format outside of...
I'm looking for a general purpose API/web service/tool/etc... that allows convert a given HTML page to an RDF graph as specific as possible (most probably using a back bone ontology and/or mapper). ...
Hi, I have a RDF file thats used to track item revisions. Using this data I can traceback the changes made to an item through its lifetime. Once a specific has changed the corresponding data is placed as a new revision. Have a look.. @prefix rdf: <http://www.w3.org/1999/02/22-rdf-syntax-ns#> . @prefix rdfs: <http://www.w3.org/2000/0...
I'm planning a system that combines various data sources and lets users do simple queries on these. A part of the system needs to act as an abstraction layer that knows all connected data sources: the user shouldn't [need to] know about the underlying data "providers". A data provider could be anything: a relational DBMS, a bug tracking...
Can I represent ontology by using XML? Why it is considered better to represent ontology by RDF? ...
hi, I'm trying to deserialize the following XML node (RDF actually) into a class. <rdf:Description rdf:about="http://d.opencalais.com/genericHasher-1/dae360d4-25f1-34a7-9c70-d5f7e4cfe175"> <rdf:type rdf:resource="http://s.opencalais.com/1/type/em/e/Country"/> <c:name>Egypt</c:name> </rdf:Description> [Serializable] ...
Hi there does anyone know of any good software for visualising an rdf triple store as an actual graph? I am using an arc2 triplestore and have already tried the visualizer plug in that is available from semasols site but I cant get it to work: I keep getting theis error: XML Parsing Error: no element found Location: data:image/svg+xml;b...
When using the skos vocabulary, is it possible to provide a descriptive label to describe a relationship between two concepts. for example you can have two concepts linked by skos:related but hwo do you say exactly how they are related. ...
If you are building an RSS parser, how important is it to build support for RDF? Are any new feeds being published in only RDF? My thinking was that RSS 2.0 (and Atom) have replaced RDF. I actually had not heard of RDF until a client pointed out some feeds that are RDF-only. ...
I am using php's simple xml and xpath to parse an rdf xml file and am struggling to get a list of all the rdf:about values. Any advice? ...
Hi, what would be the xpath for the following: Find all child nodes with a specific attibute value but starting from a node with a specific attribute value. This is kind of related to a question I posted earlier about parsing and rdf xml file - I thought I had solved it but not quite yet. For example I am trying to parse and grab all ...
I like these a lot, and would like to use them for everything. Why would doing RDF triple stores for everyday programming (Entities/Tables), such as Contacts, Customers, Company etc. be a bad idea. Are there short falls in the technology that I have not come across. I was concerned about retrieving data, but I think this is covered wit...
Hi Guys, 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/s...