My research interests include (but are not limited to:)) pattern recognition, information retrieval, online communities, bioinformatics, cryptography, and statistical natural language processing. I also like working on practical inventions.

Refereed Publications

  1. U. Topkara, M. Topkara, M. J. Atallah, "Passwords for Everyone: Secure Mnemonic-based Accessible Authentication", Proceedings of the 2007 USENIX Annual Technical Conference, Santa Clara, CA, June 17-22, 2007. (paper, presentation)
  2. M. Topkara, U. Topkara, M. J. Atallah, "Information Hiding through Errors: A Confusing Approach", Proceedings of the SPIE International Conference on Security, Steganography, and Watermarking of Multimedia Contents, January 29- February 1, 2007, San Jose, CA. (paper)
  3. U. Topkara, M. J. Atallah, M. Topkara,"Passwords Decay, Words Endure: Secure and Re-usable Multiple Password Mnemonics ", Proceedings of 22d Annual ACM Symposium on Applied Computing (SAC 07), Seoul, Korea, March 2007. (paper, presentation)
  4. M. Topkara, U. Topkara, M. J. Atallah, "Words Are Not Enough: Sentence Level Natural Language Watermarking", Proceedings of ACM Workshop on Content Protection and Security (in conjuction with ACM Multimedia), Santa Barbara, CA, October 27, 2006. (paper)
  5. U. Topkara, M. Topkara, M. J. Atallah, "The Hiding Virtues of Ambiguity: Quantifiably Resilient Watermarking of Natural Language Text through Synonym Substitutions", Proceedings of ACM Multimedia and Security Workshop, Geneva, Switzerland, September 26-27, 2006. (paper, presentation)
  6. S. Jeyaraman, U. Topkara, "Have the cake eat it too: Infusing Usability into Password Authentication Systems", Proceedings of the 21st Annual Computer Security Applications Conference, Tucson, AZ, December 5-9, 2005.
  7. Mehmet Koyuturk, Yohan Kim, Umut Topkara, Shankar Subramaniam, Wojciech Szpankowski, and Ananth Grama, "Pairwise alignment of protein interaction networks", Journal of Computational Biology, 13(2), 182-199, 2006.
  8. Y. Kim, M. Koyuturk, U. Topkara, A. Grama, S. Subramaniam, "Inferring Functional Information from Domain Co-evolution", Bioinformatics, 22(1), 40-49, 2006.
  9. M. Topkara, U. Topkara, C. Taskiran, E. Lin, M. J. Atallah, E. J. Delp, "A Hierarchical Protocol for Increasing the Stealthiness of Steganographic Methods", Proceedings of the ACM Multimedia and Security Workshop, Magdeburg, Germany, September 20-21, 2004.
  10. M. Atallah, V. Raskin, C. F. Hempelmann, M. Karahan, R. Sion, U. Topkara, K. E. Triezenberg, "Natural Language Watermarking and Tamperproofing", Proc. of the Information Hiding Workshop IHW 2002, Lecture Notes in Computer Sciences, Springer Verlag (LNCS).
  11. Zhirong Wang, Umut Topkara, Tanja Schultz, Alex Waibel, "Towards Universal Speech Recognition", IEEE International Conference on Multimodal Interfaces, Pittsburgh, PA, USA, October 14-16, 2002.

Theses and Dissertations

  1. U. Topkara, "Information Security Applications of Natural Language Processing Techniques", PhD Dissertation, Purdue University Computer Science Department, West Lafayette, 2007. (pdf)
  2. U. Topkara, "Prefix-Suffix Based Statistical Language Models of Turkish", MS Thesis, Bilkent University Computer Engineering Department, Ankara, 2001. (pdf)

Other Publications

  1. U. Topkara, C. X. Song, S. P. Park, J. Woo, P. Smith, "SORCERESS: A Scalable, Extensible Real-Time Status Service for TeraGrid Condor Resources", Proceedings of the 2007 Teragrid Conference, Madison, WI, JUne 4-8, 2007.
  2. C. X. Song, U. Topkara, J. Woo, and S.P. Park. "Assessing Reliability of Grid Software Systems Using Emergent Features," The 2nd Workshop on Reliability and Robustness in Grid Computing Systems, the 19th Open Grid Forum (OGF19), Chapel Hill, NC. January 31, 2007.
  3. U. Topkara, C.X. Song, J. Woo, S.P. Park, "Connected in a Small World: Rapid Integration of Biological Resources", Grid Computing Environments Workshop (in conjuction with Supercomputing'06), Tampa, FL, November 5, 2006. (paper) (presentation)
  4. Carol Song, Umut Topkara, Jungha Woo, Sang Phill Park, and Minou Bina. Enabling Advanced Bioinformatics Research through SALSA: A Scalable, Simple Architecture, TG06, Indianapolis, 2006.
  5. C. Taskiran, U.Topkara, M. Topkara, E. J. Delp, "Attacks on Lexical Natural Language Steganography Systems", Proceedings of the SPIE International Conference on Security, Steganography, and Watermarking of Multimedia Contents VI, January 15 - 19, 2006, San Jose, CA.
  6. A. Kumcu, U. Topkara, A. Unal, "RFID Technology in Healthcare Industry", Krannert Technology Forecast 2004-2006, Krannert School of Management, Purdue University, 2004.
  7. A. Kumcu, U. Topkara, A. Unal, "D-TRACK, Providing Intelligent Drug Administration Technologies for Patient Safety", Purdue Life Sciences Business Plan Competition, March 2004.
  8. M.J. Atallah, S. Bangalore, D. Hakkani-Tur, M. Karahan, S. Katzenbeisser, O. Rambow, G. Riccardi, and U. Topkara. "Proposal for natural language watermarking". Summer Workshops at the Center Language and Speech Processing Proposal Evaluations, 2003.
  9. U. Topkara, I. Uysal, I. Yoncaci, "Networks with Dynamic Topologies: A Greedy Algorithm for Satellite Placement Problem", BAS2000, Ankara, 2000. (pdf)
  10. E. Cetin, E. Ozkural, U. Topkara, "Viewing Station: A Software for Viewing and Analysis of DICOM images", Conference of Internet in Turkey, Ankara, 1999.