Tim Furche

Contact.

eMail:
Paper mail (work):: Department of Computer Science, Oxford University
Wolfson Building, Parks Road
Oxford OX1 3QD
United Kingdom
Office:: 351, Wolfson Building, Parks Road
Telefon (office):: +44-1865-6-10643
Paper mail (home):: Flat 8 Summertown Court
264-266 Woodstock Road
Oxford OX2 7NW
United Kingdom

Currently working on...

Implementation of Web Query Language Reconsidered: Beyond Tree and Single-Language Algebras at (Almost) No Cost

continuation of my Doctoral thesis (supervisor François Bry, reviewer Georg Gottlob), “summa cum laude”. Institute for Informatics, University of Munich.

In my thesis, I introduce a novel class of graphs (CIGs), that is a proper subclass of trees and forests, yet still exhibits linear time and space complexity for tree query evaluation. This class of graphs is complemented by a query algebra, called CIQCAG. CIQCAG evaluates any graph query on any form of graph, yet is linear for tree queries on CIGs. Read on »

RDFLog: Taming Existence in RDF Querying

Work in progress, published at WLP and RR.

We have reconsidered the combination of RDF and rules, paying particular attention to the novel features of RDF such as blank nodes or RDFS. The result, called RDFLog, illustrates (a) the cost of blank nodes for RDF querying, (b) decidable fragments of RDF-based rule languages, and (c) establishes a new normal form for RDF rules with blank nodes. A prototype for fast, XSB-based evaluation of RDF queries with (possibly recursive) rules and blank nodes in any position is available. Read on »

Quo Vadis, Web Queries?

Work in progress, published in Proc. Int'l. Workshop on Semantic Web Technology (Web4Web), 2008, and in KiWi Deliverable D2.1.

Various query languages for Web and Semantic Web data, both for practical use and as an area of research in the scientific community, have emerged in recent years. At the same time, the broad adoption of the internet where keyword search is used in many applications, e.g. search engines, has familiarized casual users with using keyword queries to retrieve information on the internet. Unlike this easy-to-use querying, traditional query languages require knowledge of the language itself as well as of the data to be queried. Keyword-based query languages for XML and RDF bridge the gap between the two, aiming at enabling simple querying of semi-structured data, which is relevant, e.g., in the context of the emerging Semantic Web. This article presents an overview of traditional query languages for XML and RDF, focused on emerging preeminent exemplars in each ﬁeld, and contrasts these languages with the ﬁeld of keyword querying for XML and RDF. Read on »

A bit about…

I've been working as a researcher on databases and the Semantic Web for over 6 years. In that time I've been involved

in establishing an equivalent, forward-only normal form for XPath that is now widely cited and used;
in the design and implementation of a streaming processor for nearly full XPath with close to time and space optimal complexity for any XPath evaluation;
in the design and implementation of the first versatile Web query language Xcerpt that combines ease of use with the ability to access data in different Web formats;
in the development of a linear time and space evaluation of tree queries on a substantially larger sets of graphs than covered by previous methods;
in the design and implementation of an algebra and abstract machine common to most Web query languages such as Xcerpt, XQuery, XPath, Xcerpt, and SPARQL, that provides the best-known complexity for evaluating each of these languages.

My current focus is on the last two items, in particular on further investigation of linear time and space evaluation for a novel class of graphs, called continuous-image graphs, introduced in my doctoral thesis. Read on »

I am also interested in applications of logic and logic programming to Web information systems. We are currently investigating, with colleagues from Oxford University, the impact of existential knowledge (or blank nodes) on querying RDF with rules. We have established a normal form for rules with existential quantifiers (where no universal quantifier occurs in the scope of an existential one) and proved that this normal form is equivalent to rules where universal and existential quantifiers can arbitrarily alternate. Read on »

Curriculum vitae

2010–: Senior Post-Doc in the DIADEM ERC project at the Department of Computer Science, Oxford University
2008–2010: Research and teaching assistant at the University of Munich
2004–2008: Research assistant in the EU network of excellence REWERSE at the University of Munich
2003: Diploma in computer science with distinction at the University of Munich
2000–2001: External consultant for IT-Startup Yollo AG (design and development of Web 2.0 editor for movies with ad synchronisation)
1996–1998: Software engineer at the Diakonissenanstalt Stuttgart
1996: High school diploma (Abitur) with distinction in computer science, history, and ancient greek at the Eberhard-Ludwigs-Gymnasium, Stuttgart

Awards, Scholarships, and Distinctions

2008: summa cum laude dissertation in computer science
2003: diploma in computer science with distinction
1995: awarded scholarship by the German National Merit Foundation (“Studienstiftung des Deutschen Volkes”)
1995: first place in state contest on ancient greek by Humanismus Heute
1995: accepted to nation-wide summer school for intellectually gifted students (“Deutsche SchülerAkademie”) on the topic of incompleteness of formal systems supported by the german ministry for education and research and the “Stifterverband für die Deutsche Wissenschaft”

Publications.
peer-reviewed

2011

Taking the OXPath down the Deep Web

with Andrew Sellers, Georg Gottlob, Giovanni Grasso, and Christian Schallhart. In Proc. Int'l. Conf. on Extending Database Technology (EDBT). 2011. Read on »

2010

Not So Creepy Crawler: Crawling the Web with XQuery

with Franziska von dem Bussche, Klara Weiand, Benedikt Linse, and François Bry. In Proc. Future Internet Symposium (FIS), (System demonstration). 2010. Read on »

KWilt: A Semantic Patchwork for Flexible Access to Heterogeneous Knowledge

with Klara Weiand, Steffen Hausmann, and François Bry. In Proc. Int'l. Conf. on Web Reasoning and Rule Systems (RR). 2010. Read on »

A RPL through RDF: Expressive Navigation in RDF Graphs

with Harald Zauner, Benedikt Linse, Tim Furche, and François Bry. In Proc. Int'l. Conf. on Web Reasoning and Rule Systems (RR). 2010. Read on »

PEST: Term-Propagation over Wiki Structures as Eigenvector Computation

with Klara Weiand, Fabian Kneißl, and François Bry. In Proc. Workshop on Semantic Wikis (SemWiki), Best paper award. 2010. Read on »

Not So Creepy Crawler: Easy Crawler Generation with Standard XML Queries

with Franziska von dem Bussche, Klara Weiand, Benedikt Linse, and François Bry. In Proc. Int'l. World Wide Web Conf. (WWW), (System demonstration). 2010. Read on »

2009

The Perfect Match: RPL and RDF Rule Languages

with Francois Bry, Benedikt Linse. In Proc. Int'l. Conf. on Web Reasoning and Rule Systems (RR), 2009. Read on »

SPARQLog: SPARQL with Rules and Quantification

with Francois Bry, Clemens Ley, Benedikt Linse, Bruno Marnette, and Olga Poppe. In R. De Virgilio, F. Giunchiglia, and L. Tanca, editors, Semantic Web Information Management: A Model-based Perspective. Springer, 2009. Read on »

Labeling RDF Graphs for Linear Time and Space Querying

with Francois Bry and Antonius Weinzierl. In R. De Virgilio, F. Giunchiglia, and L. Tanca, editors, Semantic Web Information Management: A Model-based Perspective. Springer, 2009. Read on »

Web Queries: From a Web of Data to a Semantic Web

with Francois Bry and Klara Weiand. Tutorial at Int'l. Conf. on Web Information System Engineering (WISE). 2009. Read on »

Four Lessons in Versatility or How Query Languages Adapt to the Web

with François Bry, Benedikt Linse, Alexander Pohl, Antonius Weinzierl, and Olga Yestekhina . In F. Bry and J. Maluszynski, editors, Semantic Techniques for the Web. Springer, 2009. Read on »

Semantic Web Query Languages

with James Bailey, Francois Bry, and Sebastian Schaffert. In M. T. Özsu and L. Liu, editors, Encyclopedia of Database Systems. Springer, 2009. Read on »

2008

Quo Vadis, Web Queries?

with Klara Weiand and François Bry. In Proc. Int'l. Workshop on Semantic Web Technology (Web4Web), 2008. Read on »

Xcerpt^RDF: A Pattern-based Answer to the Versatile Web Challenge

with François Bry and Benedikt Linse. In Proc. Workshop on (Constraint) Logic Programming (WLP), 2008. Read on »

RDFLog: It's like Datalog for RDF

with François Bry, Clemens Ley, Benedikt Linse, and Bruno Marnette. In Proc. Workshop on (Constraint) Logic Programming (WLP), 2008. Read on »

Taming Existence in RDF Querying

with François Bry, Clemens Ley, Benedikt Linse, and Bruno Marnette. In Proc. Int'l. Conf. on Web Reasoning and Rule Systems (RR) (Poster), 2008. Read on »

Simulation Subsumption or Déjà vu on the Web

with François Bry and Benedikt Linse. In Proc. Int'l. Conf. on Web Reasoning and Rule Systems (RR), 2008. Read on »

Implementation of Web Query Language Reconsidered: Beyond Tree and Single-Language Algebras at (Almost) No Cost

Doctoral thesis (supervisor François Bry, reviewer Georg Gottlob), “summa cum laude”. Institute for Informatics, University of Munich. Read on »

2007

Modular Web Queries---From Rules to Stores

with Uwe Aßmann, Sacha Berger, François Bry, Jakob Henriksson, and Jendrik Johannes. In Proc. Int'l. Workshop on Scalable Semantic Web Knowledge Base Systems (SSWS), LNCS 4806. 2007. Read on »

A Generic Module System for Web Rule Languages: Divide and Rule

with Uwe Aßmann, Sacha Berger, François Bry, Jakob Henriksson, and Paula-Lavinia Pătrânjan. In Proc. Int'l. RuleML Symp. on Rule Interchange and Applications, LNCS 4824. 2007. Read on »

Visual Languages: A Matter of Style

with Sacha Berger, François Bry, and Christoph Wieser. In Proc. Workshop on Visual Languages and Logic (VLL). 2007. Read on »

Completing Queries: Rewriting of Incomplete Web Queries under Schema Constraints

with Sacha Berger, François Bry, and Andreas J. Häusler. In Proc. Int'l. Conf. on Web Reasoning and Rule Systems (RR), LNCS 4524. 2007. Read on »

Querying the Web Reconsidered: Design Principles for Versatile Web Query Languages

with François Bry, Liviu Badea, Christoph Koch, Sebastian Schaffert, and Sacha Berger. In A. Sheth and M. D. Lytras (eds.), Semantic Web-Based Information Systems: State-of-the-Art Applications. 2007.

Foundations of Rule-Based Query Answering

with François Bry, Norbert Eisinger, Thomas Eiter, Georg Gottlob, Clemens Ley, Benedikt Linse, Reinhard Pichler, and Fang Wei. In G. Antoniou, U. Aßmann, C. Baroglio, S. Decker, N. Henze, P.-L. Pătrânjan, and R. Tolksdorf (eds.) Tutorial Lectures Int'l. Summer School ‘Reasoning Web’, LNCS 4636. 2007. Read on »

GRDDLing with Xcerpt: Learn one, get one free!

with François Bry, Alina Hang, and Benedikt Linse. In Proc. European Semantic Web Conf. (ESWC), (System demonstration). 2007. Read on »

2006

Rich Clients need Rich Interfaces: Query Languages for XML and RDF Access on the Web

with James Bailey, François Bry, Benedikt Linse, Paula-Lavinia Pătrânjan, and Sebastian Schaffert. In Proc. of German XML-Tage, (Tutorial). 2006. Read on »

The Web and Semantic Web Query Language Xcerpt

with Sacha Berger, François Bry, Benedikt Linse, and Sebastian Schaffert. In AIS SIGSEMIS and OSR Semantic Web Fact Book 2005. 2006. Read on »

Beyond XML and RDF: The Versatile Web Query Language Xcerpt

with Sacha Berger, François Bry, Benedikt Linse, and Andreas Schroeder. In Proc. Int'l. World Wide Web Conf. (WWW), (System demonstration). 2006. Read on »

Effective and Efficient Data Access in the Versatile Web Query Language Xcerpt

with Sacha Berger, François Bry, Benedikt Linse, and Andreas Schroeder. In Proc. Int'l. Workshop on Principles and Practice of Semantic Web Reasoning (PPSWR), (System demonstration), LNCS 4187. 2006. Read on »

Xcerpt and visXcerpt: Integrating Web Querying

with Sacha Berger, François Bry, and Tim Furche. In Informal Proc. ACM SIGPLAN Workshop on Programming Language Technologies for XML (Plan-X), (System demonstration). 2006. Read on »

Vorführung von Xcerpt und visXcerpt, Anfragesprachen für das Web

with Sacha Berger, François Bry, Benedikt Linse, and Andreas Schroeder. In Proc. GI-Workshop on Grundlagen von Datenbanken, (System demonstration). 2006. Read on »

Let's Mix It: Versatile Access to Web Data in Xcerpt

with François Bry, and Benedikt Linse. In Proc. of Workshop on Information Integration on the Web (IIWeb). 2006. Read on »

Data Model and Query Constructs for Versatile Web Query Languages: State-of-the-Art and Challenges for Xcerpt

with François Bry and Benedikt Linse. In Proc. Int'l. Workshop on Principles and Practice of Semantic Web Reasoning (PPSWR), LNCS 4187. 2006. Read on »

AMachoS - Abstract Machine for Xcerpt: Architecture and Principles

with François Bry and Benedikt Linse. In Proc. Int'l. Workshop on Principles and Practice of Semantic Web Reasoning (PPSWR), LNCS 4187. 2006. Read on »

Efficient Evaluation of n-ary Conjunctive Queries over Trees and Graphs

with François Bry, Benedikt Linse, and Andreas Schroeder. In Proc. ACM Int'l. Workshop on Web Information and Data Management (WIDM). 2006. Read on »

RDF Querying: Language Constructs and Evaluation Methods Compared

with Benedikt Linse, François Bry, Dimitris Plexousakis, and Georg Gottlob. In Tutorial Lectures Int'l. Summer School `Reasoning Web', LNCS 4126. 2006. Read on »

Querying the Semantic Web: A Case Study

with Loïc Royer, Benedikt Linse, Thomas Wächter, François Bry, and Michael Schroeder. In C. J. Baker and K.-H. Cheung (eds.), Revolutionizing Knowledge Discovery in the Life Sciences. 2006. Read on »

2005

Web and Semantic Web Query Languages: A Survey

with James Bailey, François Bry, and Sebastian Schaffert. In Tutorial Lectures Int'l. Summer School `Reasoning Web', LNCS 3564. 2005. Read on »

Querying the Standard and Semantic Web using Xcerpt and visXcerpt

with Sacha Berger, Fran\c{c}ois Bry, Oliver Bolzer, Sebastian Schaffert, and Christoph Wieser. In Proc. European Semantic Web Conf. (ESWC), (System demonstration). 2005. Read on »

The XML Stream Query Processor SPEX

with François Bry, Fatih Coskun, Serap Durmaz, Dan Olteanu, and Markus Spannagel. In Proc. Int'l. Conf. on Data Engineering (ICDE), (System demonstration). 2005. Read on »

Querying the Web Reconsidered: Design Principles for Versatile Web Query Languages

with François Bry, Liviu Badea, Christoph Koch, Sebastian Schaffert, and Sacha Berger. In Journal of Semantic Web and Information Systems, 1(2). 2005. Read on »

How to Query the GeneOntology

with Andreas Doms, Albert Burger, and Michael Schroeder. In Symposium on Knowledge Representation in Bioinformatics (KRBIO). 2005. Read on »

XML Perspectives on RDF Querying: Towards integrated Access to Data and Metadata on the Web

with François Bry, and Oliver Bolzer. In Proc. GI-Workshop on Grundlagen von Datenbanken. 2005. Read on »

Marriages of Convenience: Triples and Graphs, RDF and XML

with François Bry, and Oliver Bolzer. In Proc. Int'l. Workshop on Principles and Practice of Semantic Web Reasoning (PPSWR), LNCS 3703. 2005. Read on »

2004

Xcerpt and visXcerpt: Twin Query Languages for the Semantic Web

with Sacha Berger, François Bry, Oliver Bolzer, Sebastian Schaffert, and Christoph Wieser. In Proc. Int'l. Semantic Web Conf. (ISWC), (System demonstration). 2004. Read on »

Data Retrieval and Evolution on the (Semantic) Web: A Deductive Approach

with François Bry, Paula-Lavinia Pătrânjan, and Sebastian Schaffert. In Proc. Int'l. Workshop on Principles and Practice of Semantic Web Reasoning (PPSWR), LNCS 3208. 2004. Read on »

Datenströme

with François Bry, and Dan Olteanu. In Informatik Spektrum, 27(2). 2004. Read on »

An Efficient Single-Pass Query Evaluator for XML Data Streams

with Dan Olteanu, and François Bry. In Data Streams Track,Proc. ACM Symp. on Applied Computing (SAC), (System demonstration). 2004. Read on »

2003

Optimizing Multiple Queries against XML Streams

Diploma thesis (supervisor François Bry, Dan Olteanu), “1,0”. Institute for Informatics, University of Munich. Read on »

Evaluating Complex Queries against XML streams with Polynomial Combined Complexity

with Dan Olteanu, Tim Furche, and François Bry. In Proc. British National Conf. on Databases (BNCOD). 2003. Read on »

2002

XPath: Looking Forward

with Dan Olteanu, Holger Meuss, Tim Furche, and François Bry. In Proc. EDBT Workshop on XML-Based Data Management, LNCS 2490. 2002. Read on »

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Teaching.

Courses, Lectures, Exercises

2009: Exercises for Markup-Sprachen und semi-strukturierte Daten, substitute lecturer
2008–2009: Exercises for Übersetzerbau: Abstrakte Maschinen, substitute lecturer
2008: Exercises for Informatik IV (supervision with Norbert Eisinger)
2006: Graduate seminar on Data Modelling for the Semantic Web (design and supervision with Prof. F. Bry)
2005: Graduate seminar on Query Languages and Visualisation for the Semantic Web (design and supervision with Prof. F. Bry)
2001: Lab course on XML and E-Commerce (supervision with Dan Olteanu and Prof. F. Bry)
2000: Lab course on XML and E-Commerce (design and supervision with Tim Geisler and Prof. F. Bry)
1997: Industrial training at the Diakonissenanstalt Stuttgart on standard software (repeated half-day beginner and three-day advanced courses)

Software.

2008: AMaχoS: linear time and space query engine for XQuery, XPath, SPARQL, and Xcerpt. Prototypical implementation of Xcerpt 2.0.
2007: RDFLog: Prototype for fast, XSB-based evaluation of RDF queries with (possibly recursive) rules and blank nodes in any position; Xcerptware: A version of Xcerpt with modules created in collaboration with the authors of the Reuseware composition framework
2004: SPEX (Streamed and Progressive Evaluation of XPath queries): nearly full-featured evaluator for XPath on streams (but: no value-based joins) with polynomial combined complexity
2003: MQ-SPEX: Multi-query optimizer for SPEX that outputs networks of SPEX's streaming operators that allow the concurrent evaluation of multiple queries. Multiple optimization algorithms for problem size up to hundreds of queries.
2002: Streaming Content Manager: interactive Javascript editor for composing presentations from streaming movies and ads, including fully visual placement of ad position, ad length, etc. Developed for the now-defunct Yollo AG.

Reviewing.

Evaluator for National and International Funding Agencies

2009: EU Framework 7 Call 5, ICT Objective 4.3 “Intelligent Information Management”: independent expert evaluator for both consensus and hearing stage.

I work on information systems for the Web: linear evaluation of Web queries on graph data, reasoning, web extraction, web and object search, and streamed query evaluation.

Contact.

Currently working on...

A bit about…

Curriculum vitae

Awards, Scholarships, and Distinctions

Publications. peer-reviewed

Querying the Web Reconsidered: Design Principles for Versatile Web Query Languages

Teaching.

Software.

Reviewing.

Evaluator for National and International Funding Agencies

Membership in program committees

External reviewer

Publications.
peer-reviewed