research position avaliable

I have a three-year research position avaliable on the EPSRC-funded project: 
Spatial Logics for Querying Data on the Web. The official start date is 1st 
April 2003 although there should be some flexiblity with this. Please email
me  if you are interested. The position would suit someone  with experience 
in one or more of the following areas: foundations of distributed systems,  
database theory, programming language semantics in general, more practical 
experience in distributed systems, languages for XML, type theory, spatial 
logics, finite model theory.

Details can be found below and at http://www.doc.ic.ac.uk/~pg/spatial.html

Salary will be on the RA1A scale, currently 17,451-26,229 per annum depending 
on age and experience. Candidates should preferably have  a PhD or  an 
equivalent  research background.

Formal applications should include a full CV, a statement of  research 
interests, pointers to relevant publications, and contact details for 2-3 

Best wishes,

Philippa Gardner
Imperial College, London


Project title: Spatial Logics for Querying Data on the Web 

The (unofficial) collaborators on this project are Luca Cardelli and 
Giorgio Ghelli. 

Project Aims: 

Semi-structured data (such as XML) plays an important role in the 
exchange of information between globally distributed applications. 
Whilst the research community mostly agree on defining semi-structured 
data using labelled directed graphs or trees with `graphical links', the 
study of how to query, modify and manipulate such data is still very active. 
This research project focusses on the study of spatial logics for reasoning 
about semi-structured data, and the application of these logics to provide 
query languages for manipulating such data. We will introduce a `trees with 
pointers model', a new data structure for representing data on the Web. Our 
model focusses on dangling pointers which we believe occur naturally: for 
example, a link to a webpage that is currently down. Dangling pointers are
used by O'Hearn and Reynolds in their work on pointer arithmetic, but are not 
emphasised by existing semi-structured data models. We will develop a spatial 
logic for our model, which allows us to reason locally about disjoint 
substructures. We will design a query language  which integrates well with
our model and logic, and compare our approach with existing languages such as 
XML-QL and XDuce. We will extend our models to incorporate 
dynamically-changing structure, as a step towards understanding the dynamic 
nature of the Web.

PhD students associated with the project:

Sergio Maffeis, funded by Microsoft Research, Cambridge
Uri Zarfaty, funded by EPSRC