IIT Madras is a public technical and research university located in Chennai, Tamil Nadu. Founded in 1959, it is recognised as an Institute of National Importance.

IIT Madras has been ranked as the top engineering institute in India for four years in a row by the National Institutional Ranking Framework of the MHRD

It currently offers undergraduate, postgraduate and research degrees across 16 disciplines in Engineering, Sciences, Humanities and Management. About 596 faculty belonging to science and engineering departments and centres of the Institute are engaged in teaching, research and industrial consultancy.

IIT Madras

Department of Humanities and Social Sciences

Department Of Physics

Department of Applied Mechanics

Department of Aerospace Engineering

Department of Ocean Engineering

Department Of Civil Engineering

Department of Metallurgical and Materials Engineering

Department of Mechanical Engineering

Department of Mathematics

World University root node

Economic and Political Weekly

Erratum: Sheer insensitivity (Economic and Political Weekly (2011))

The aim of this paper is to construct the parabolic version of the Donaldson-Uhlenbeck compactification for the moduli space of parabolic stable bundles on an algebraic surface with parabolic structures along a divisor with normal crossing singularities. We prove the non-emptiness of the moduli space of parabolic stable bundles of rank 2.

Fulltext

Proceedings of the Indian Academy of Sciences: Mathematical Sciences

Parabolic bundles on algebraic surfaces I - The Donaldson-Uhlenbeck compactification

In this paper, we present an approach to generate speaker invariant features for automatic speech recognition (ASR) using the idea of spectral centre of gravity(CG). This is based on the observation that if two signals are delayed versions of one another, then their CG's also differ by the same amount. We exploit this idea to appropriately shift the mel warped log compressed spectra using the estimated CG to obtain speaker invariant features. The use of such speaker invariant or normalised features helps improve the recognition performance of speaker-independent ASR. We show that our proposed approach is computationally efficient when compared to a commonly used method of normalisation called Vocal Tract Length Normalisation (VTLN). We present normalisation results to show that the performance of our proposed approach is comparable to conventional VTLN and yet has the advantage of computational efficiency. Copyright © 2008 ISCA.

Department of Electrical Engineering

Proceedings of the Annual Conference of the International Speech Communication Association, INTERSPEECH

Use of spectral centre of gravity for generating speaker invariant features for automatic speech recognition

Abstract is unavailable for this paper.

Michigan Math. J

Singularities of moduli spaces of vector bundles over curves in characteristic 0 and p

We study degenerations of rank 3 quadratic forms and of rank 4 Azumaya algebras, and extend what is known for good forms and Azumaya algebras. By considering line-bundle-valued forms, we extend the theorem of Max-Albert Knus that the Wittinvariant—the even Clifford algebra of a form—suffices for classification. An algebra Zariski-locally the even Clifford algebra of a ternary form is so globally up to twisting by square roots of line bundles. The general, usual and special orthogonal groups of a form are determined in terms of automorphism groups of its Witt-invariant. Martin Kneser’s characteristic-free notion of semiregular form is used.

Journal of Pure and Applied Algebra

Line-bundle-valued ternary quadratic forms over schemes

It is shown that the schematic image of the scheme of Azumaya algebra structures on a vector bundle of rank 4 over any base scheme is separated, of finite type, smooth of relative dimension 13 and geometrically irreducible over that base and that this construction base-changes well. This fully generalizes Seshadri's theorem in [16] that the variety of specializations of (2 x 2)-matrix algebras is smooth in characteristic ≠ 2. As an application, a construction of Seshadri in [16] is shown in a characteristic-free way to desingularize the moduli space of rank 2 even degree semi-stable vector bundles on a complete curve. As another application, a construction of Nori over ℤ (Appendix, [16]) is extended to the case of a normal domain which is a universally Japanese (Nagata) ring and is shown to desingularize the Artin moduli space [1] of invariants of several matrices in rank 2. This desingularization is shown to have a good specialization property if the Artin moduli space has geometrically reduced fibers - for example this happens over ℤ. Essential use is made of Kneser's concept [8] of 'semi-regular quadratic module'. For any free quadratic module of odd rank, a formula linking the half-discriminant and the values of the quadratic form on its radical is derived.

Limits of rank 4 Azumaya algebras and applications to desingularization