I have moved to The Pennsylvania State University. You can find my Penn State page here.
If you are looking for my Ph.D. dissertation, it is here.

Prasenjit Mitra

1714 Heavenly Bamboo Court,
San Jose, CA 95131
Email Address : mitra@.db.stanford.edu*
(408) 254-4904 (r)
(650) 723-3605 (o)
Ph.D. Candidate in Electrical Engineering, Stanford University, Stanford, CA
Curriculum Vitae
Research Statement
Teaching Statement


  • Graduate: M.S.  University of Texas at Austin, in Computer Science December, 1994.
  • Undergraduate: B.Tech.(Hons.)  Indian Institute Technology, Kharagpur, in Computer Science and Engineering August, 1993.

  • I went to high-school at Don Bosco School, Bandel, in West Bengal, India.

  • Research Interests:

    Databases, with an emphasis on designing techniques and tools to enable integration and interoperation of data and knowledge over the Internet and across enterprises. In particular: schema matching, query optimization, ontology composition, and information extraction.

    I am working on the OntoAgents research project at Infolab along with my advisor Prof. Gio Wiederhold to design and implement the ONtology CompositION(ONION) system.

    The primary roadblock preventing the success of data integration and interoperation systems is the absence of effective tools to establish semantic mappings between large data sources. We have worked on building a Semantic Knowledge Articulation Toolkit that employs a strategy that uses lexical, structural and instance information present in the data sources to find such semantic mappings. Using these semantic mappings, I demonstrated how to compose information from multiple data sources. I utilized ontologies - schema-like structures containing metadata regarding the terms and relationships in the sources - wherever available, to add precision to our data integration efforts. To systematize the composition of information from multiple sources I designed an Ontology-Composition Algebra and showed how to optimize the composition of information from multiple data sources based on the properties of the algebraic operators.

    For an overview of the ONION system please consult the ONION paper that was published in EDBT 2000. The articulation generator has been discussed in the Fusion '99 paper and the ECAI workshop 2002 paper on resolving terminological heterogeneity.


    On ONION

    The following papers give a system overview, discusses the basic concepts, the data model and the ontology algebra:

  • Prasenjit Mitra, Martin Kersten and Gio Wiederhold: Graph-Oriented Model for Articulation of Ontology Interdependencies".
    Stanford University Technical Note, CSL-TN-99-411, August, 1999 and in Proceedings of the 7th International Conference on Extending Database Technology, EDBT 2000. Available as [PDF].

  • Prasenjit Mitra, Gio Wiederhold and Stefan Decker: A Scalable Framework for Interoperation of Information Sources.
    Proceedings of the 1st International Semantic Web Working Symposium (SWWS `01), Stanford University, Stanford, CA, July 29-Aug 1, 2001, Jul. 2001. Available as [PDF].
    Slightly enhanced version in the "Selected Papers from the Semantic Web Working Symposium" book. Available as [Postscript][PDF].

  • Prasenjit Mitra, and Gio Wiederhold: An Algebra for Semantic Interoperability of Information Sources.
    Proceedings of 2nd. IEEE Symp. on BioInformatics and Bioengineering, BIBE 2001, Bethesda, MD, Nov. 2001. Available as [Postscript][PDF].

  • Prasenjit Mitra, Gio Wiederhold and Jan Jannink: Semi-automatic Integration of Knowledge Sources.
    Proceedings of Fusion '99, Sunnyvale, USA, July 1999. Available as [PS].

  • Prasenjit Mitra, and Gio Wiederhold: Resolving Terminological Heterogeneity in Ontologies.
    Proceedings of Workshop on Ontologies and Semantic Interoperability at the 15th European Conference on Artificial Intelligence (ECAI), 2002. Lyon, France, July 2002. Available as [PDF]

    On Answering Queries Using Views:

    The following paper highlights the Shared Variable Bucket algorithm that ONION uses:

  • Prasenjit Mitra: " An Algorithm for Answering Queries Efficiently Using Views";
    Stanford University Technical Report, 21st September, 1999 and also in Proceedings of the Australasian Database Conference, Jan 2001.

  • Foto Afrati, Chen Li, and Prasenjit Mitra: Answering Queries Using Views with Arithmetic Comparisons.
    Proceedings of the ACM Symposium on Principles of Database Systems (PODS), June 3-6, 2002 Madison, Wisconsin. [PS][PDF]
  • Other publications:

  • Stefan Decker, Prasenjit Mitra, Sergey Melnik: Framework for the Semantic Web: An RDF Tutorial.
    In IEEE Internet Computing. November/December 2000.

  • Stefan Decker, Jan Jannink, Sergey Melnik, Prasenjit Mitra, Steffen Staab, Rudi Studer and Gio Wiederhold: An Information Food Chain for Advanced Applications on the WWW.
    Proceedings of the Fourth European Conference on Research and Advanced Technology for Digital Libraries (ECDL '2000), Lisbon, 2000.

  • Jan Jannink, Prasenjit Mitra, Srinivasan Pichai, Gio Wiederhold, Erich Neuhold, and Rudi Studer: An Algebra for Semantic Interoperation of Seminstructured Data; in 1999 IEEE Knowledge and Data Engineering Exchange Workshop, Chicago, USA, November 1999.
  • Prasenjit Mitra, David Payne, Lance Shuler, Robert van de Geijn, and Jerrell Watts: " Fast Collective Communication Libraries, Please "; in Proceedings of the Intel Supercomputing Users' Group Meeting, 1995 and Department of Computer Sciences, The Unversity of Texas, Technical Report, TR-95-22, June 1995. c.

  • Pallab Dasgupta, Prasenjit Mitra, and P.P. Chakraborty: Multiobjective Search in VLSI Design; in Proceedings of the 7th IEEE/CSI International Symposium on VLSI Design, Calcutta, India, January 1994.

    * Please remove the extra dot from my email address listed above to get my correct email address. It is put in to discourage automatic spamming routines that parse the page and decipher email addresses. Sorry about that!