Thursday, November 24, 2005

Ideas for the aggregation of distributed (P2P) RDF and Topic Maps

This blog entry is about some ideas on how to aggregate content with markup in RDF and topic maps which is distributed over the web. The aggregation may also be accomplished P2P-like.

1. Problem space/application areas
-----------------------------------
I want to use existing RDF/Topic Maps annotations. Those can be understood as disaggregations of underlying texts, dervice by humans annotating.

My aggregation will lead to innovative knowledge products and knowledge services.

I will not only aggregate assertions, but also aggregate (compose) knowledge services. A knowledge service can be implemented with TMRAP on top of a topic map.

See e.g. the slides of my talk
kPeer (Knowledge Peers): Informationssuche beim verteilten SemBloggen

The project "SemNetMan" (Semantisch basiertes Netzwerkmanagement) [1] combines:
SNA (Social Network Analysis) with Semantic Web Technologies

Similarly, Peter Mika is doing his dissertation research [2] on Social Networks and the Semantic Web, applying it to Flink [3].

I myself want to achieve semblogging, integration of content from weblogs which have semantic markup.

2. Architecture
---------------
According to [4], three elements are useful for this:
(1) RTM (RDF to topic maps mapping),
(2) PSIs, and
(3) topic map content distributed on the web

RTM is currently implemented in the commercial solution OKS and the Omnigator, and according to the slides, a TMAPI implementation is also under way (but I do not know the status and which backend would support that already).

A tutorial-like description for RTM mapping (for SKOS) is given in [5], and a description of RTM itself can be found in [6, 7].

So, where do I get a PSI collection from?

TopicMapster (TMShare) [8] is the idea of exchanging topic map fragments in P2P fashion.

This has meanwhile become possible in practice with TMRAP (Topic Maps Remote Access Protocol) [9] (version 1.0 will be available end of 2005 in OKS)
It is a web service for Topic Maps
For an explanation, see [10, 11]

Which (free) topic map software does/will support TMRAP?
(There seems to be some early TMRAP support in TM4J? (see Sourceforge-CVS of TM4Web)

Alternative approaches:
TMIP [12], or SNAPI [13]

3. Technical tools
-----------------
To collect RDF triples from various sources into one store, one could use, on an experimental basis, RDF::Scutter [14]. It is a web robot collecting distributed RDF into a central store.

It is based on RDF::Redland [15], a Perl binding for Redland framework [16]. Redland itself is a "free, open source C library for parsing, storing and querying RDF files"

(Yes, there is also a Java binding for Redland) [17]

Redland is useing RDQL for queries [18]

Two tutorials how to use RDF::Redland from Perl [19, 20]

To bind RDF triples to Perl objects in general, one can use Class::RDF [21]

References
[1]
http://www.semantics2005.net/semnetman-semantisch-basiertes-management-sozialer-netzwerke.workshop.60.11.htm

[2]
http://www.cs.vu.nl/~pmika/research.html
http://www.cs.vu.nl/~pmika/research/papers/VUBIS-PhDproposal.doc

[3]
http://flink.semanticweb.org/

[4]
[Garshol & Naito 2004] Realization of seamless knowledge: connecting distributed RDF and Topic Maps", presented 2004-11-06 at SIG-SWO-A403-04
http://www.jaist.ac.jp/ks/labs/kbs-lab/sig-swo/papers/SIG-SWO-A403/SIG-SWO-A403-04.pdf (2 pages, Abstract)
http://www.knowledge-synergy.com/topicmaps/document/sig-swo.pdf (16 slides, PDF)

[5]
Garshol, Marius: SKOS in Topic Maps
Blog entry 2005-10-24
http://www.garshol.priv.no/blog/10.html

[6]
The RTM RDF to topic maps mapping: Definition and introduction
2003-12-28
http://www.ontopia.net/topicmaps/materials/rdf2tm.html

[7]
Lars Marius Garshol: Living with topic maps and RDF: Topic maps, RDF, DAML, OIL, OWL, TMCL
http://www.ontopia.net/topicmaps/materials/tmrdf.html

[8]
Ahmed, Khalil (2003): TMShare - Topic Map Fragment Exchange In a Peer-To-Peer Application. In: Procs. XML Europe 2003, 2003. http://www.idealliance.org/papers/dx_xmle03/papers/02-03-03/02-03-03.html
http://www.techquila.com/topicmapster.html

[9]
Pepper, Steve (2004-04-17): Topic Maps Remote Access Protocol 0.2
(Technical report)
http://www.jtc1sc34.org/repository/0507.htm

[10]
[Garshol 2006] Garshol, Lars Marius (2006): TMRAP: A Web Service Protocol for Topic Maps. Procs. TMRA'05, International Workshop on Topic Map Research and Applications, Leipzig, Oct 6-7, 2005. Springer (under preparation)
Online: http://www.informatik.uni-leipzig.de/~tmra05/PRES/LMGa.pdf (slides)

[11]
[Pepper & Garshol 2004] Pepper, Steve & Garshol, Lars Marius (2004): Seamless Knowledge. Spontaneous Knowledge Federation using Topic Maps. Late breaking talk, presented at Extreme Markup Languages 2004, Montréal, Quebec, Canada, August 2-6.
Online:
http://www.ontopia.net/topicmaps/materials/Seamless%20Knowledge%20with%20TMRAP.ppt
(slides, with title: Seamless Knowledge. Spontaneous Knowledge Federation using TMRAP)

[12]
Barta, Robert: TMIP, a RESTful Topic Maps Interaction Protocol,
Presentation at Extreme Markup 2005
http://www.mulberrytech.com/Extreme/Proceedings/xslfo-pdf/2005/Barta01/EML2005Barta01.pdf

[13]
SNAPI - Semantic Network API
http://sourceforge.net/projects/snapi

[14]
RDF::Scutter
http://search.cpan.org/~kjetilk/RDF-Scutter-0.1/lib/RDF/Scutter.pm

[15]
RDF::Redland
http://search.cpan.org/~djbeckett/Redland-0.9.14.1/

[16]
Redland
http://librdf.org/

[17]
Java-Binding for Redland
http://librdf.org/docs/java.html

[18]
RDQL
http://www.w3.org/Submission/RDQL/

[19]
http://www.robertprice.co.uk/robblog/archive/2004/10/Querying_RDF_In_Perl_with_RDF_Redland.shtml

[20]
Barta, Robert (Perl expert in the topic maps community)
http://james.bond.edu.au/courses/inft73371/043/redland.mc

[21]
Class::RDF
http://search.cpan.org/~zooleika/Class-RDF-0.20/