Am 22.07.2011 um 19:27 schrieb Rupert Westenthaler: > Hi > > Let me add my first comments > >> >> LMF Core >> ======== >> >> The core component of the Linked Media Framework is a Linked Data Server >> that allows to expose data following the Linked Data Principles: >> * Use URIs as names for things. >> * Use HTTP URIs, so that people can look up those names. >> * When someone looks up a URI, provide useful information, using the >> standards (RDF, SPARQL). >> * Include links to other URIs, so that they can discover more things. >> The Linked Data Server implemented as part of the LMF goes beyond the Linked >> Data principles by extending them with Linked Data Updates and by >> integrating management of metadata and content and making both accessible in >> a uniform way. In addition to the Linked Data Server, the LMF Core also >> offers a SPARQL endpoint. >> > > The Linked Data Server incl. the LMF extensions (content+metadata and > full CRUD) functionality would be a very nice extension for STANBOL: > (1) because it is central for the plant Contenthub.(2) it is also > relevant for the Entityhub and (3) if we design this component smart, > that it should be possible that it could provide an easy way for many > existing CMS systems to support LOD for there contents.
Number (3) is actually the central argument that we had for LMF, just that our partners are not really CMS providers. They are more in the media asset management and document management area. But the same arguments and approaches hold there ;-) I have some ideas on how to do this integration properly. At the moment, the LMF stores content itself, which is not really practical. It would be much more reasonable to have a configurable redirect from the content URIs to the respective content management systems (could even be several different at the same time using some kind of configurable mapping - a content management system, a media asset management system, a wiki ...) > >> LMF Modules >> =========== >> >> As extension for the LMF Core, we are working on a number of optional >> modules that can be used to extend the functionality of the Linked Media >> Server: >> >> Implemented: >> * LMF Semantic Search offers a highly configurable Semantic Search service >> based on Apache SOLR. Several semantic search indexes can be configured in >> the same LMF instance using an RDF Path Language that allows traversal over >> several Linked Data sources. > > At first this sounds similar to the SolrYard used by the Entityhub but > in the details it is very different. [...] Thanks for the clarification, I should maybe have emphasised this. SOLR can indeed be used for many different purposes - in our case it is actually exposed to the user and not only used internally. Therefore we want the SOLR service to be "as much SOLR as possible", because we want users to be able to use existing SOLR tools like the great AJAX-SOLR. > >> * LMF Reasoner implements a rule-based reasoner that allows to process >> Datalog-style rules over RDF triples; the LMF Reasoner is based on the >> reasoning component developed in the KiWi project, the predecessor of the LMF >> > > In my opinion this component may have the biggest impact if used in > combination with the LMF Semantic Search/Indexing component - adding > the possibility to use Rules (in addition to the RDF Path Language) > to specify how to build documents for the semantic index. > If this can solve the licencing Issues with current Reasoners would be > interesting. I think the current Rule/Reasoner functionality is based > on OWL-DL and SWRL and I do not know how that relates to Datalog-style > rule languages. The problem I have with existing reasoners is that they are either only Description Logics or Description Logics+Rules. In both cases they introduce the high complexity of DL reasoning, but DL reasoning is mostly only interesting for consistency and schema checking. Even if the DL people claim that DL is decidable, this only means that the reasoner will terminate eventually in finite time - but this may be in 1000 years.;-) A purely rule-based reasoner can be much more efficient. >> > > However the LMF provides also a lot of Semantic CMS capabilities. > Features like "LMF Versioning", "LMF Permissions" and its dependency > to Hibernate are hints about that. Stanbol explicitly excludes such > stuff because one can typically already find this features in the > existing CMS stacks of potential Stanbol users. The dependency to Hibernate is mostly for the triple store, not for CMS capabilities. And this is something I don't see how to avoid in the near future because we need to store additional information about triples for reasoning and versioning. Versioning is also of triples, not of content. As such it is probably also interesting to the Stanbol community. Permissions is a topic that will likely become highly relevant for Stanbol as well. We actually only added it because it is a requirement of the SNML technology partners. There are e.g. many cases where only selected people should have access to the metadata or even the fact of existance of a resource (consider a document about a medical treatment ...). The real Semantic CMS functionality in the LMF should go away anyways, even in the SNML scenarios. Because they are very similar to the CMS scenarios in IKS anyways ... so this is a good opportunity to do it :) Greetings, Sebastian -- | Dr. Sebastian Schaffert [email protected] | Salzburg Research Forschungsgesellschaft http://www.salzburgresearch.at | Head of Knowledge and Media Technologies Group +43 662 2288 423 | Jakob-Haringer Strasse 5/II | A-5020 Salzburg
