The Latin hypercube design is a popular choice of experimental design when computer simulation is used to study a physical process. These designs guarantee uniform samples for the marginal distribution of each single input. A number of methods have been proposed for extending the uniform sampling to higher dimensions. We show how to construct Latin hypercube designs in which all main effects ar...

We characterize, up to a conjecture, probability distributions of finite all order moments with ultraspherical type generating functions for orthogonal polynomials. 1. Motivation: Meixner families There is a one to one correspondance between probability distributions on the real line and polynomials of a one variable satisfying a three-terms recurrence relation subject to some positivity condit...

We apply random matrix theory to complex networks. We show that nearest neighbor spacing distribution of the eigenvalues of the adjacency matrices of various model networks, namely scale-free, small-world, and random networks follow universal Gaussian orthogonal ensemble statistics of random matrix theory. Second, we show an analogy between the onset of small-world behavior, quantified by the s...

Let μ be a probability measure on the real line with finite moments of all orders. Apply the Gram-Schmidt orthogonalization process to the system {1, x, x, . . . , xn, . . . } to get orthogonal polynomials Pn(x), n ≥ 0, which have leading coefficient 1 and satisfy (x − αn)Pn(x) = Pn+1(x) + ωnPn−1(x). In general it is almost impossible to use this process to compute the explicit form of these po...

Absfracf This paper considers Multi-Carrier CDMA (MCCDMA) communication systems. Recently, the asymptotic performance of a multiuser MMSE receiver for a MC-CDMA system has been established, assuming orthogonal spreading codes and equal powers. A similar study has also been conducted for a DS-CDMA system, considering in this ease unequal powers. The introduction of orthogonal codes can he consid...

Digital age today has shown increasing reliance on digital media and rapid distribution of digital contents. The issues of piracy and copyright are of immense concern in this exponentially increasing digital revolution. In this paper, authors propose use of bi-orthogonal wavelet transform as an effective tool to address copyright infringement issues. A synergistic combination of bi-orthogonal w...

In a fast fading channel, the orthogonality of the two consecutive Space Time Block Codes (STBC)-Orthogonal Frequency Division Multiplexing ( OFDM) symbols will be destroyed and the received signals cannot be perfectly separated. TR(Tone Reservation) is a technique designed to combat this problem by reserving a number of carries(tone) in the frequency domain to generate a cancellation signal in...

A general method for constructing asymmetric orthogonal arrays of arbitrary strength is proposed. Application of this method is made to obtain several new families of tight asymmetric orthogonal arrays of strength three. A procedure for replacing a column with 2 symbols in an orthogonal array of strength three by several 2-symbol columns, without disturbing the orthogonality of the array, leads...

The study of Wiener-Levinson digital filters leads to certain classes of polynomials orthogonal on the unit circle (Szego polynomials). Here we present theorems that show that the unknown frequencies in a periodic discrete time signal can be determined from the limiting behavior (as N -+ co) of the zeros of fixed degree Szego polynomials that are orthogonal with respect to a distribution define...

Abstract Using the theory of exponential Riordan arrays and orthogonal polynomials, we demonstrate that the general Eulerian polynomials, as defined by Xiong, Tsao and Hall, are moment sequences for simple families of orthogonal polynomials, which we characterize in terms of their three-term recurrence. We obtain the generating functions of this polynomial sequence in terms of continued fractio...