J. López-Bonilla

Steganographic method based on wavelets and center weighted median filter

In this paper, we present a robust steganographic method for hidden information in the wavelet domain. The proposed method uses the Iterative Center Weighted Median (ICWM) algorithm to estimate the noisy areas of an RGB image. We propose to use the noisy pixels or areas as places to hidden information to provide good invisibility and fine detail preservation of processed images. The proposed method consistently identifies if the wavelets coefficients of an image contains noisy or not, this algorithm works with variances and standard deviations of the same wavelet coefficients of image.

Krige Method Application for the Coverage Analysis of a Node-B in a WCDMA Network

This paper shows the procedure and application of the Krige Method (or Kriging) for the analysis of the power level radiated by a Base Station (also called Node B), through a group of samples of this power level, measured at different positions and distances. These samples were obtained using an spectrum analyzer, which will allow to have georeferenced measurements, to implement the interpolation process and generate coverage maps, making possible to know the power level distribution and therefore understand the behavior and performance of the Node B.

Equidistant and Non-Equidistant Sampling for Method of Moments Applied to Pocklington Equation

We present a non-equidistant sampling for the method of moments in the solution of Pocklington equation operator, to prove the reduction of segments junctions and conductor far end discontinuities. Comparison of equidistant and non-equidistant sampling is presented, obtaining E field over the surface of a lambda/2 dipole.

Three–dimensional effective mass Schrödinger equation: harmonic and Morse-type potential solutions

In this work, a scheme to generate exact wave functions and eigenvalues for the spherically symmetric three-dimensional position-dependent effective mass Schrödinger equation is presented. The methodology is implemented by means of separation of variables and point canonical transformations that allow to recognize a radial dependent equation with important differences as compared with the one-dimensional position dependent mass problem, which has been widely studied. This situation deserves to consider the boundary conditions of the emergent problem. To obtain specific exact solutions, the methodology requires known solutions of ordinary one-dimensional Schrödinger equations. We have preferred those applications that use the harmonic oscillator and the Morse oscillator solutions.

Performance Characterization Parameters on Voice and Data Transmission in Mobile Terminals to Cellular Networks

This work presents the experimental results related to performance measurements in GSM and GPRS cellular data networks. Two Mobile Terminals were used, in order to take place the scenario. Power Level, Power vs. Time, Modulation Analysis, Modulation Spectrum, (BER) Bit Error Rate and Throughput were considered in this analysis.

Robust steganographic method based on center weighted median algorithm

In this paper, a robust method for hidden information in the wavelet domain is presented. The proposed steganographic method uses the Wavelet domain iterative center weighted median (WDICWM) algorithm to estimate the noise areas of an RGB color image. The noise areas or pixels are proposed as places to hidden information to provide good invisibility and fine detail preservation of processed images. The proposed steganographic method consistently identifies if the wavelets coefficients of an image contains noise pixels or not, this algorithm works with variances and standard deviations of the same wavelet coefficients of image. The experimental results from a known technique are compared with the proposed method to demonstrate its performance in terms of objective and subjective sense.

UNA PROPUESTA DIDÁCTICA PARA LA CARACTERIZACIÓN DE DISPOSITIVOS Y REDES ELÉCTRICAS DE RADIOFRECUENCIA EN LA BANDA DE 100 KHz A 500 MHz

Resumen es: En este articulo se presenta un esquema didactico de prueba y medicion para la caracterizacion en el dominio de la frecuencia de componentes y circuitos ...

On the Melzak and Wilf Identities

Authors use the Stirling numbers of the second kind to show an identity of Wilf, which in turn implies a formula of Melzak. To cite this article [Montiel-Pérez, J. H., López-Bonilla, J., & Vidal-Beltrán, S. (2017). On the Melzak and Wilf Identities. The Journal of Middle East and North Africa Sciences, 3(11), 1-3]. (P-ISSN 24129763) (e-ISSN 2412-8937). www.jomenas.org. 1

Position-Dependent Mass Schrödinger Equation for the Morse Potential

The position dependent mass Schrodinger equation (PDMSE) has a wide range of quantum applications such as the study of semiconductors, quantum wells, quantum dots and impurities in crystals, among many others. On the other hand, the Morse potential is one of the most important potential models used to study the electronic properties of diatomic molecules. In this work, the solution of the effective mass one-dimensional Schrodinger equation for the Morse potential is presented. This is done by means of the canonical transformation method in algebraic form. The PDMSE is solved for any model of the proposed kinetic energy operators as for example the BenDaniel-Duke, Gora-Williams, Zhu-Kroemer or Li-Kuhn. Also, in order to solve the PDMSE with Morse potential, we consider a superpotential leading to a special form of the exactly solvable Schrodinger equation of constant mass for a class of multiparameter exponential-type potential along with a proper mass distribution. The proposed approach is general and can be applied in the search of new potentials suitable on science of materials by looking into the viable choices of the mass function.

Experimental Analysis of Voice and Data Transmission Parameters for Mobile Terminals in Cellular Data Networks

This work presents the experimental results related to performance measurements in GSM and GPRS cellular data networks. Two Mobile Terminals were used, in order to take place the scenario. Power Level, Power vs Time, Modula-tion Analysis, Modulation Spectrum, (BER) Bit Error Rate and Throughput were considered in this analysis.