Multiobjectives bihistogram equalization for image contrast enhancement

The global histogram equalization (HE) has been the most frequently adopted image contrast enhancement technique. A brightness and detail‐preserving HE method with good contrast enhancement effect has been a goal of much recent research in HE. Nevertheless, producing a well‐balanced HE is deemed to be a daunting task. In this article, we propose a novel framework of HE with the aim of taking three desirable properties into account: brightness preservation, detail preservation, and contrast enhancement. We termed the proposed method as multipurpose beta optimized bi‐HE (MBOBHE). MBOBHE consists of performing the histogram optimization separately in both subhistograms after the segmentation of histogram using an optimized separating point based on the three performance criteria using a weighted‐sum aggregated objective function (AOF). Both quantitative and qualitative results indicate that MBOBHE outperforms other existing bi‐HE methods, in terms of comprehensive performance of HE that is capable of providing a holistic view. © 2014 Wiley Periodicals, Inc. Complexity 20: 22–36, 2014     

General decay of solutions of a wave equation with a boundary control of memory type

In this paper we consider a semilinear wave equation, in a bounded domain, where the memory-type damping is acting on a part of the boundary. We establish a general decay result, from which the usual exponential and polynomial decay rates are only special cases. Our work allows certain relaxation functions which are not necessarily of exponential or polynomial decay and, therefore, generalizes and improves earlier results in the literature.     

An efficient serial distributed arithmetic algorithm for FPGA implementation of digital up conversion

This article deals with a computationally efficient serial distributed arithmetic algorithm producing a device efficient field programmable gate array implementation. The proposed algorithm takes half the computations time as compared to the conventional symmetric algorithms. The algorithm is analyzed for a direct conversion transmitter of ionospheric radar. Matching and buffering criterion are used to reduce the arithmetic process. The algorithm can be extended to applications with similar characteristics, particularly for System On Chip (SOC) techniques. © 2005 Wiley Periodicals, Inc. Complexity 11: 24–29, 2005     

A strong consistency of a nonparametric estimate of entropy under random censorship

The purpose of this Note is to provide the rate of strong consistency for a nonparametric estimator of entropy under random censorship. We also establish an uniform-in-bandwidth consistency for this estimator. To cite this article: S. Bouzebda, I. Elhattab, C. R. Acad. Sci. Paris, Ser. I 347 (2009).     

Exponential decay for a quasilinear viscoelastic equation

We consider the following nonlinear viscoelastic equation together with Dirichlet-boundary conditions, in a bounded domain Ω and ρ > 0. We prove an exponential decay result for a class of relaxation functions. Our result is established without imposing the usual relation between g and its derivative (© 2009 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)     

Photodissociation of sodium iodide and resonant ionization of sodium atom produced

Resonant ionization spectroscopy (RIS) and resonant ionization mass spectroscopy (RIMS) are employed to detect the photodissociation product of sodium iodide molecules in a molecular beam in an intense laser field in the absence of the buffer gases. Time of flight mass spectra is recorded. In particular, the appearances of multiphoton ionization are discussed.     

On averaging of the non-periodic conductivity coefficient using two-scale extensions

We consider a second order elliptic equation with known rapidly oscillated coefficient. The equation appears to describe such problems as heat transfer in composite materials, flow in non-homogeneous porous media as well as in many others. For the periodic coefficient the averaging procedure is well known. The non-periodic case is still a challenging problem. We present a two-scale extension approach and apply it on one numerical example in 2D. (© 2005 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)