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Optimal random sampling for spectrum estimation in DASP applications

Andrzej Tarczynski, Dongdong Qu (2005)

International Journal of Applied Mathematics and Computer Science

In this paper we analyse a class of DASP (Digital Alias-free Signal Processing) methods for spectrum estimation of sampled signals. These methods consist in sampling the processed signals at randomly selected time instants. We construct estimators of Fourier transforms of the analysed signals. The estimators are unbiased inside arbitrarily wide frequency ranges, regardless of how sparsely the signal samples are collected. In order to facilitate quality assessment of the estimators, we calculate...

Optimality conditions for maximizers of the information divergence from an exponential family

František Matúš (2007)

Kybernetika

The information divergence of a probability measure P from an exponential family over a finite set is defined as infimum of the divergences of P from Q subject to Q . All directional derivatives of the divergence from are explicitly found. To this end, behaviour of the conjugate of a log-Laplace transform on the boundary of its domain is analysed. The first order conditions for P to be a maximizer of the divergence from are presented, including new ones when P  is not projectable to .

Optimality of the Width- w Non-adjacent Form: General Characterisation and the Case of Imaginary Quadratic Bases

Clemens Heuberger, Daniel Krenn (2013)

Journal de Théorie des Nombres de Bordeaux

We consider digit expansions j = 0 - 1 Φ j ( d j ) with an endomorphism Φ of an Abelian group. In such a numeral system, the w -NAF condition (each block of w consecutive digits contains at most one nonzero) is shown to minimise the Hamming weight over all expansions with the same digit set if and only if it fulfills the subadditivity condition (the sum of every two expansions of weight 1 admits an optimal w -NAF).This result is then applied to imaginary quadratic bases, which are used for scalar multiplication in elliptic...

Optimally approximating exponential families

Johannes Rauh (2013)

Kybernetika

This article studies exponential families on finite sets such that the information divergence D ( P ) of an arbitrary probability distribution from is bounded by some constant D > 0 . A particular class of low-dimensional exponential families that have low values of D can be obtained from partitions of the state space. The main results concern optimality properties of these partition exponential families. The case where D = log ( 2 ) is studied in detail. This case is special, because if D < log ( 2 ) , then contains all probability...

Order statistics and ( r , s ) -entropy measures

María Dolores Esteban, Domingo Morales, Leandro Pardo, María Luisa Menéndez (1994)

Applications of Mathematics

K. M. Wong and S. Chen [9] analyzed the Shannon entropy of a sequence of random variables under order restrictions. Using ( r , s ) -entropies, I. J. Taneja [8], these results are generalized. Upper and lower bounds to the entropy reduction when the sequence is ordered and conditions under which they are achieved are derived. Theorems are presented showing the difference between the average entropy of the individual order statistics and the entropy of a member of the original independent identically distributed...

Parallel implementation of local thresholding in Mitrion-C

Tomasz Kryjak, Marek Gorgoń (2010)

International Journal of Applied Mathematics and Computer Science

Mitrion-C based implementations of three image processing algorithms: a look-up table operation, simple local thresholding and Sauvola's local thresholding are described. Implementation results, performance of the design and FPGA logic utilization are discussed.

Parametric logarithmic type image processing for contrast based auto-focus in extreme lighting conditions

Corneliu Florea, Laura Florea (2013)

International Journal of Applied Mathematics and Computer Science

While most of state-of-the-art image processing techniques were built under the so-called classical linear image processing, an alternative that presents superior behavior for specific applications comes in the form of Logarithmic Type Image Processing (LTIP). This refers to mathematical models constructed for the representation and processing of gray tones images. In this paper we describe a general mathematical framework that allows extensions of these models by various means while preserving...

Planning identification experiments for cell signaling pathways: An NFκB case study

Krzysztof Fujarewicz (2010)

International Journal of Applied Mathematics and Computer Science

Mathematical modeling of cell signaling pathways has become a very important and challenging problem in recent years. The importance comes from possible applications of obtained models. It may help us to understand phenomena appearing in single cells and cell populations on a molecular level. Furthermore, it may help us with the discovery of new drug therapies. Mathematical models of cell signaling pathways take different forms. The most popular way of mathematical modeling is to use a set of nonlinear...

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