Primary User (PU) signal detection is critical for cognitive radio networks as it allows a secondary user to find spectrum holes for opportunistic reuse. Eigenvalue based detection has many advantages, such as it does not require knowledge on primary user signal or noise power level. However, most of the work on eigenvalue based detection methods presented in the literature require multiple sen...

Expressions are given for the maximum and minimum values of Poisson’s ratio ν for materials with cubic symmetry. Values less than −1 occur if and only if the maximum shear modulus is associated with the cube axis and is at least 25 times the value of the minimum shear modulus. Large values of |ν| occur in directions at which the Young’s modulus is approximately equal to one half of its 111 valu...

The above inequality, which is an immediate consequence of Bernstein’s inequality on the derivative of a trigonometric polynomial, is best possible with equality holding for the polynomial p(z)= λzn, λ being a complex number. If we restrict ourselves to the class of polynomials having no zeros in |z| < 1, then the above inequality can be sharpened. In fact Erdös conjectured and later Lax [7] pr...

We study the kernels Kn,s(z) in the remainder terms Rn,s(f) of the Gauss-Turán quadrature formulae for analytic functions on elliptical contours with foci at ±1, when the weight ω is a generalized Chebyshev weight function. For the generalized Chebyshev weight of the first (third) kind, it is shown that the modulus of the kernel |Kn,s(z)| attains its maximum on the real axis (positive real semi...

Let f (z) be an arbitrary entire function and M(f ,r) = max |z|=r | f (z)|. For a polynomial P(z) of degree n, having no zeros in |z| < k, k ≥ 1, Bidkham and Dewan (1992) proved max |z|=r |P (z)| ≤ (n(r + k) n−1 /(1 + k) n)max |z|=1 |P(z)| for 1 ≤ r ≤ k. In this paper, we generalize as well as improve upon the above inequality.