ericP beside rock near Nice

About Me

I am a sanitation engineer employed by the World Wide Web Consortium (W3C), working in Cambridge MA at MIT's fabulous Stata Center.

W3C Working Groups

In my time at W3C, I have worked at all three hosts: MIT's Computer Science and Artificial Intelligence Laboratory (CSAIL) in the USA, the European Research Consortium for Informatics and Mathematics (ERCIM) headquartered in France and Keio University in Japan. My major work responsibilities have included libwww and the client applications, a PEP model library, perl modules for RDF databases, SQL databases, RDF visualizers, annotations support, apache, mozilla,web services and lots of systems stuff. My interests lie in machine interpretation of data have lead me down the Semantic Web road, though that path is oddly ambiguous.


I am currently a team contact for the W3C Semantic Web Health Care and Life Sciences Interest Group (HCLSIG) and working part time on SPASQL.


And here's stuff I need to get around to:

  1. ACLs: Express W3C ACLs as SPASQL mapping rules. Tie back to XACML.
  2. EARL: Record lessons learned from DAWG's use of EARL. Geek with Sandro about EARL for RIF.
  3. SPARQLfed: Query-on-query functionality for SPARQLfed parser for ISWC paper. Compare expressivities between Defult DB Mapping and D2R.
  4. Turtle: Integrate semantic actions into Turtle Grammar to address PFPS's comments. Finish the eternal Turtle/N3 media types issue.
  5. POWDER: finish IRI= doc.
  6. learn etags.

Nerd Score

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Here's a bit of stuff I remember coming up on radar...


Given a BNF grammar, yacker writes parsers in C, C++, perl and python. I use it for tracking evolution in languages that I've implemented. Also nice to settle LL(1)/LALR(1) issues in real time.


WSDL (and its embedded XML Schema) have annotation mechansims. Adding WSDL and XML Schema annotations that associate RDF GraphTerms with allows a mapping between SPARQL triples and a locations in a SOAP message. See the write-up and the write-up of the subsidiary SPAT language.

MySQL+SPARQL — LillyGrants project

Having played with mapping SPARQL (and Algae2) queries to SQL, I decided to move that logic into mysqld, allowing arbitrary clients of the conventional MySQL protocol (perl, dbi, ODBC, JDBC) use of it with no modification. See the code, write-up and some earlier notes.


RDAL - RDF Annotations Language — another schema annotations, this time for Relax NG. RDAL associates semantic actions (stored in RNG Annotations) with call-outs to a generic API; implemented as a validating XSLT with callouts to another XSLT library.

media type identification

As web protocols are are more and more stacked, the conventional two-tier media-type mechanism becomes insufficient to hint to applications that they may or may not have some utility in looking at the entity. The list of IANA media types is available in a general IANA registry.

processing pipeline control

Machine understanding implies machines are told what consitutes sufficient processing. I actually don't even remember writing this proposal.

XML protocols:

XML Protocol Matrix

Briefly describe and contrast a set of XML protocols. RPC and messaging, mostly.

XML Processing Pipeline Model

The modularity of XML specifications deliniates a set of functionality boundries. Different documents will require differnet modules. This document is a plea for a taxonmy of modules names, ordering and optional processing directives.

RDF WSDL Mapping

provides an algorithmic transformation of WSDL document to an RDF model.

Annotated RDF WSDL Examples

example of use of the RDF WSDL Mapping.

web services use case: bike shop

NOT DONE - barely even started - don't look here.

semantic web web services survey

survey of web service research from the RDF perspective.

Enhanced XML DTD for XHTML, MathML, XVG, and some RDF

Adds RDF support for Creative Commons to a sample document.


Resource nodes to describe documents, analogous to i-nodes, implemented over http extensions.

RDF Topic Maps

Topic Maps describe associations of objects (identified by URI). RDF describes relationships between objects. This document describes a few algorithmic mappings between the two.

RDF tools:

RDF Databases, parsers, ...

perl libraries

Semantic schema annotation

The above perl RDF parser uses an XML-centric grammer with scripted actions associated with each production. This workes to parser many forms of XML. I hope this work leads language requirements for a general schema annotation language.

RDFXML to RDF database XSLT.

This provides an alternative to the an XML-centric grammer approach used by the perllib parser.


A way to present a user with policies from a published P3P policy.

Constrasting Knowledge Representation in MOF, Topic Maps and RDF.

Many communities decide to use RDF or Topic Maps or UML without understanding the overlaps or constrasts in expressivity of those systems. This paper attempts to reduce FUD (fear, uncertainty and doubg) and promote some common understanding.

RDF storage facilities:

Persistent RDF Databases

While rdf parsers allow us to access to RDF stored in XML or N3 documents, persistent triple stores provide more convenient access.

RDF <-> SQL interfaces.

For many applications, using a triple store is less efficient than using a database optimized for the particular data. This RDF SQL Mapping paper describes using such a database as an RDF database.

new RDF SQL mapping.

This paper explores RDF access to an OrderTracking database and demonstrates practical queries to the database.

Hetrogeneous RDF databases.

We can get much more efficient use of databases if we normalize our data into conventional relations. This paper demonstrates that this normalizations need not sacrifice flexibility of expression.

Source Attributions in RDF.

Many RDF database implementations support an attribution or context. There is no standard way to do this. This paper explores some alternatives and discusses their respective pros and cons.

RDF query facilities:

RDF query protocols

Similar to the XML protocol matrix.

storage implications on query efficiency

RDF SQL mapping paper also discusses this.

semantic grid

juncture between semantic web and the grid forum.

HTTP Protocols:

HTTP Extensions

Implementations for Apache and Mozilla.


Protocol Extension Protocol

Team Comments:


Abstrace API for access to RDF datastores. Has concrete bindings in SOAP and HTTP GET/PUT/POST/DELETE.

Recent & Upcoming Travel


  10 Jun 0800 UN173 BOSc→SFO  

  20 Jun 0810 AC563 SFO →YVR 

  25 Jun 1100 UA768 YVR →ORD (26 Jun)
  26 Jun 0630 UA525 ORD →BOS 


  31 Jul   1730 AF337 BOSe→CDGe 0645 (20 Oct)
  10 Aug   1315 AF332 CDGf→BOSe 1555

✈→→→ (DReSNet workshop on digital repositories in biological and medical research)

13-14 July		

✈→→→ (JA00)

4-9 Oct