Mohamed Shalaby

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Cognitive radio is an emerging technology, which aims to upgrade the spectrum utilization by allowing the secondary users to operate at the spectrum bands vacated by the primary users. A cognitive radio system model was simulated and the performance of the energy detector was evaluated by using different wireless channel models. These models include(More)
We present techniques for creating an approximate implicit representation of space curves and of surfaces of revolution. In both cases, the proposed techniques reduce the problem to that of implicitization of planar curves. For space curves, which are described as the intersection of two implicitly defined surfaces, we show how to generate an approximately(More)
We compare several methods for approximate implicitization by piece-wise polynomials which have been developed by the authors, and a linear-algebra-based numerical method for implicitization which is provided as a part of MAPLE. We investigate both quantitative criteria (such as computing time, memory use, and the error of the approximation) and qualitative(More)
We present a new method for constructing a low degree <i>C</i><sup>1</sup> implicit spline representation of a given parametric planar curve. To ensure the low degree condition, quadratic B-splines are used to approximate the given curve via orthogonal projection in Sobolev spaces. Adaptive knot removal, which is based on spline wavelets, is used to reduce(More)
We report on approximate techniques for conversion between the implicit and the parametric representation of curves and surfaces, i.e., implicitization and parameterization. It is shown that these techniques are able to handle general free-form surfaces, and they can therefore be used to exploit the duality of implicit and parametric representations. In(More)
AIM To study the possible interactions of metoclopramide, domperidone and erythromycin in streptozotocin-induced diabetic mice treated with insulin by various parameters. METHODS Effects of the individual as well as combined drugs were studied in diabetic mice via estimation of the blood glucose and serum insulin levels, small intestinal transit (SIT),(More)
Notebook and Laptop Original Equipment Manufacturers (OEMs) place great emphasis on creating unique system designs to differentiate themselves in the mobile market. These systems are developed from the `outside in' with the focus on how the system is perceived by the end-user. As a consequence, very little consideration is given to the interconnections or(More)