Santi Thompson

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With the explosive growth of internet technology robust methods are being developed to protect the proprietary rights of the multimedia. This paper considers the problem of embedding a binary watermark in a gray-level image using the concept of Visual Cryptography (VC). This paper proposes a watermarking scheme which offers better security than Hwang's(More)
A combined adaptive bounding and adaptive mutation technique is proposed both to improve the solution precision and to increase the convergence rate of genetic algorithms for continuous optimization problems. The proposed technique is tested over two benchmark continuous functions, and the results show that the proposed technique is superior to simple GAs(More)
{ This paper discusses the use of sectorised antenna array receivers for the reverse links of cellular code division multiple access (CDMA) systems. The distribution of users in the sector can seriously alter the sector capacity that can be achieved. Simulation results are presented to show the eeect of user clustering on system performance for a number of(More)
This paper proposes an adaptive zooming genetic algorithm (AZGA) for continuous optimisation problems. Other than gradually reducing the search space with a fixed reduction rate during the evolution process, the upper and lower boundaries for variables in the objective function are dynamically adjusted based on the distribution information of variables in(More)
This paper considers the performance of four channel identiication techniques for code division multiple access (CDMA) antenna array receivers. These techniques are based on the assumption that the interference is spatially white: they provide a spatial \matched lter" solution. Perturbation formulae are presented for estimating the attainable signal to(More)
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