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Full-Text Articles in Physical Sciences and Mathematics
Self-Authentication Of Audio Signals By Chirp Coding, Jonathan Blackledge, Eugene Coyle
Self-Authentication Of Audio Signals By Chirp Coding, Jonathan Blackledge, Eugene Coyle
Conference papers
This paper discusses a new approach to ‘watermarking’ digital signals using linear frequency modulated or ‘chirp’ coding. The principles underlying this approach are based on the use of a matched filter to provide a reconstruction of a chirped code that is uniquely robust in the case of signals with very low signal-to-noise ratios. Chirp coding for authenticating data is generic in the sense that it can be used for a range of data types and applications (the authentication of speech and audio signals, for example). The theoretical and computational aspects of the matched filter and the properties of a chirp …
Tight Lower Bound For The Sparse Travelling Salesman Problem, Fredrick Mtenzi
Tight Lower Bound For The Sparse Travelling Salesman Problem, Fredrick Mtenzi
Conference papers
The Sparse Travelling Salesman Problem (Sparse TSP) which is a variant of the classical Travelling Salesman Problem (TSP) is the problem of finding the shortest route of the salesman when visiting cities in a region making sure that each city is visited at least once and returning home at the end. In the Sparse TSP, the distance between cities may not obey the triangle inequality; this makes the use of algorithms and formulations designed for the TSP to require modifications in order to produce near-optimal results. A lower bound for optmisation problems gives us the quality guarantee of the near-optimal …
Poisson Structures Of Equations Associated With Groups Of Diffeomorphisms, Rossen Ivanov
Poisson Structures Of Equations Associated With Groups Of Diffeomorphisms, Rossen Ivanov
Conference papers
A class of equations describing the geodesic flow for a right-invariant metric on the group of diffeomorphisms of Rn is reviewed from the viewpoint of their Lie-Poisson structures. A subclass of these equations is analogous to the Euler equations in hydrodynamics (for n = 3), preserving the volume element of the domain of fluid flow. An example in n = 1 dimension is the Camassa-Holm equation, which is a geodesic flow equation on the group of diffeomorphisms, preserving the H1 metric.
Two Component Integrable Systems Modelling Shallow Water Waves, Rossen Ivanov
Two Component Integrable Systems Modelling Shallow Water Waves, Rossen Ivanov
Conference papers
Our aim is to describe the derivation of shallow water model equations for the constant vorticity case and to demonstrate how these equations can be related to two integrable systems: a two component integrable generalization of the Camassa-Holm equation and the Kaup - Boussinesq system.