Comparison of RDF Query Languages.

The purpose of this paper is to provide a rigorous comparison
of six query languages for RDF. We outline and categorize features
that any RDF query language should provide and compare the individual
languages along these features. We describe several practical usage
examples for RDF queries and conclude with a comparison of the expressiveness
of the particular query languages. The usecases, sample data and
queries for the respective languages are available on the web.

More on: http://www.aifb.uni-karlsruhe.de/WBS/pha/rdf-query/rdfquery.pdf#search=%22RDF%20query%20language%20comparison%22

http://www.aifb.uni-karlsruhe.de/WBS/pha/rdf-query/

From XML to RDF..

With the ongoing rapid increase in both volume and diversity of 'omic' data (genomics, transcriptomics, proteomics, and others), the development and adoption of data standards is of paramount importance to realize the promise of systems biology. A recent trend in data standard development has been to use extensible markup language (XML) as the preferred mechanism to define data representations. But as illustrated here with a few examples from proteomics data, the syntactic and document-centric XML cannot achieve the level of interoperability required by the highly dynamic and integrated bioinformatics applications. In the present article, we discuss why semantic web technologies, as recommended by the World Wide Web consortium (W3C), expand current data standard technology for biological data representation and management.

more on: http://www.nature.com/nbt/journal/v23/n9/full/nbt1139.html

UDDI as an Extended Web Service Registry..

Versioning, quality of service, and more...

http://webservices.sys-con.com/read/45102.htm

How to Version Schemas?

Version and source control for schemas and schema objects is badly needed by us all, especially in complex, multi-enterprise development situations. This paper describes how to support true versioning of schemas and fine-grained schema objects. An important conclusion is that schema evolution and schema development are essentially synonymous, in that the applicable techniques and requisite technology are the same for both.

http://www.idealliance.org/proceedings/xml04/papers/74/howToVersionSchemas.html#S1.

Versioning Web Services..

I found some thoughts on the versioning of web services which i think is the most important issue which needs to be considered by service providers.

more on: http://kalsey.com/2006/02/versioning_web_services/ and http://kalsey.com/2006/02/why_web_services_versioning_is_important/

XML vs RDF, An interesting debate on XMDR webpage..

After extensive discussion and investigation, we propose to use XML as both a data model and data exchange format for the XMDR Prototype. In addition to supporting the REST architectural style, this approach will greatly simplify both specification and development of an exemplar XMDR system. While we gave some consideration to using some less conventional representations (such as dialects of XMI and SCL), none seemed to have distinct advantages over the two major W3C formats: XML and RDF (W3C's Resource Description Framework). The exchange format is not for exchange between the registry and the sources of concept system (registry input), rather it is for exchange between the XMDR and clients. Concept systems may be received in the form of their native relational, hierarchical, or other data model. Internally, the XMDR may store the concept system in both its native data model, and the canonical XML data model.

for more details please visit http://hpcrd.lbl.gov/SDM/XMDR/arch/index.html

How do I model State, Let me count the ways by Ian Foster

We must sometimes define Web service interfaces that support operations on state, i.e., data values associated with a service that persist across operations, so that the result of one operation can depend on prior operations. We describe four different approaches to modeling state in Web service interfaces, based on the use of WSRF mechanisms, WS-Transfer mechanisms, distinct state identifiers, and simple HTTP, respectively. We show how each approach can be used to define an interface to a simple job management system, and summarize arguments that have been made for and against each approach.

http://www.gridforum.org/mail_archive/dais-wg/2005/05/doc00000.doc

Principals of metadata registries..

An excellent white paper on principal of metadata registries..

Principles of Metadata Registries

Types of Registries..

ISO 11179 Metadata Registrries - Data Semantics

OASIS ebXML registry - XML artifacts

UDDI - Web based business services regsitry

Database System registries (System catalogs/DD/Repository) - Schema, integrity and operational information

CASE Tool Repositories - Data model and application program logic

Ontological Registries - Concept structures

Software Component Registries - Software components

DCMI Regsitry - Descriptive records for information resources

Metadata Standards

XML and ISO/IEC 11179 data models.

www.epa.gov/sor/square_pegs_in_round_holes.pps

Some work on managing XML objects in an ISO/IEC 11179 Metadata Registry

Data models in brief..

Interesting discussion on relational and RDF data models

http://dannyayers.com/2005/07/16/data-models-in-brief/