Cryptography and Network Security Group- Gurumurthi V Ramanan




 


Publications

(with K.R. Sujith) Procrustes Analysis and Moore-Penrose Inverse Based Classifiers for Face Recognition

in Advances in Biometric Person Authentication: International Wokshop on Biometric Recognition Systems, IWBRS 2005, Beijing, China, October 22-23, 2005. Proceedings Editors:  Stan Z. Li, Zhenan Sun, Tieniu Tan, Sharath Pankanti, Gérard Chollet, David Zhang.

ABSTRACT:

We propose two new classifiers, one based on the classical Procrustes analysis and the other on the Moore-Penrose inverse in the context of face recognition. The Procrustes based classifier has recognition rates of 97.5%, 96.19%, 71.40% and 96.22% for the ORL, YALE, GIT and the FERET database respectively. The Moore-Penrose classifier has comparative recognition rates of 98%, 99.04%, 87.40% and 96.22% for the same databases. In addition to these classifiers, we also propose new parameters that are useful for comparing classifiers based on their discriminatory power and not just on their recognition rates. We also compare the performance of our classifiers with the baseline PCA and LDA techniques as well as the recently proposed discriminative common vectors technique for the above face databases.

 

(with P. Rajamannar) Roweis-Saul Classifier for Machine Learning 

in NINETH INTERNATIONAL SYMPOSIUM ON ARTIFICIAL INTELLIGENCE AND MATHEMATICS, 2006, FORT LAUDERDALE, FLORIDA.

ABSTRACT:

In 2000, Saul and Roweis proposed locally linear embedding as a tool for  nonlinear dimensionality reduction. In this paper, we modify the LLE algorithm and formulate it as a classifier  in a manner reminiscent of He et al.  Our experiments with the ORL, YALE, FERET face databases and MNIST handwritten  database show that our classifier has recognition rates of 95.42%, 96.67%,  95.28% and 92.50% respectively, clearly outperforming the baseline PCA and  LDA classifiers as well as the recently proposed Laplacianfaces.  We also point out some relationships between the Roweis-Saul classifier, PCA and LDA.


(with S. Anand) Periodicity, Complementarity and Complexity of 2-adic FCSR Combiner Generators 

accepted in ACM Symposium on Information, Computer and Communications Security(ASIACCS'06).


ABSTRACT:

Feedback with carry shift registers are nonlinear analogues of Linear Feedback  Shift Registers (LFSRs). Like the LFSRs, FCSRs are easy to implement and are important primitives  in stream cipher design. In this paper, we investigate the properties of combiner generators that use two 2-adic Feedback-with-Carry Shift Registers (FCSRs) as primitives  and the XOR operation as the combiner function. When the two FCSRs have odd prime power connection integers with 2 as a  primitive root, we determine the period of the output sequence. We prove that if the prime factors of the connection integers of the two  FCSRs belong to different equivalence classes modulo 4, then the output sequence is symmetrically complementary. We use this fact to derive upper bounds on the linear complexity and the 2-adic complexity of the output sequence of the FCSR-combiner.



Theses

  1. S. Anand - Search algorithms for FCSR architectures and properties of the FCSR combiner generator

    Thesis submitted to FACULTY OF ELECTRICAL ENGINEERING.

  2. P. Rajamannar -

    Variations on the theme of locally linear embedding and their applications in machine learning.

    MS Thesis submitted to FACULTY OF INFORMATION AND COMMUNICATION ENGINEERING.

  3. K.R. Sujith - An algebraic framework for classifier development and its application in Face Recognition

    MS Thesis submitted to FACULTY OF INFORMATION AND COMMUNICATION ENGINEERING.