Analysis of energy detection of unknown signals under Beckmann fading channels

(c) 2017 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other users, including reprinting/ republishing this material for advertising or promotional purposes, creating new collective works for resale or redistribution to servers or lists, or reuse of any copyrighted components of this work in other works.The Beckmann fading is a general multipath fading model which includes Rice, Hoyt and Rayleigh fading as particular cases. However, the generality of the Beckmann fading also implies a significant increased mathematical complexity. Thus, relatively few analytical results have been reported for this otherwise useful fading model. The performance of energy detection for multi-branch receivers operating under Beckmann fading is here studied, and the inherent analytical complexity is here circumvented by the derivation of a closed-form expression for the generalized moment generating function (MGF) of the received signal-to-noise ratio (SNR), which is a new and useful result, as it is key for evaluating the receiver operating characteristics. The impact of fading severity on the probability of missed detection is shown to be less critical as the SNR decreases. Monte Carlo simulations have been carried out in order to validate the obtained theoretical expressions.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech. Proyecto MINECO-FEDER TEC2013-42711-R y TEC2013-44442-P. Junta de Andalucía P11-TIC-7109

Bay leaves extracts as active additive for food protective coatings

Ethanolic extracts of bay leaves were obtained using the Soxhlet method (extraction yield of 22.3 ± 1.2%) and further analyzed through different methods, thus determining the chemical composition with gas chromatography, phenolic content with the Folin–Ciocalteu technique (11.8 ± 0.4% wt.) and antioxidant power with the radical 2,2′-Azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) method (75.06%). Furthermore, its effect on the growth of two bacteria, Escherichia coli and Bacillus cereus, and on two yeasts, Candida glabrata and Saccharomyces cerevisiae, was determined, showing a minimum inhibitory concentration of 0.65 mg/mL on the growth of B. cereus. Finally, edible films were prepared using different polymers (carboxymethyl cellulose, gum Arabic, polyvinyl pyrrolidone, and polyvinyl alcohol) containing 0, 5, 10, or 15% wt. of bay leaf extract as troubleshooting for perishable fruits, specifically for cultivated strawberry. The prepared composites presented reduced water vapor permeabilities (up to 4.3 × 10−7 g·Pa−1·m−1·h−1), high specific transparencies (≈30%/mm), as well as the effective blocking of ultraviolet radiation (>99.9%). In vivo tests showed that the most suitable treatment for strawberry protection was the impregnation with a composite comprising polyvinyl alcohol and a 15% wt. bay leaf extract, resulting in a noteworthy reduction in mass loss (22% after 6 days). It can be asserted that food packaging with the designed composites would be an effective alternative for the reduction in postharvest losses

Impact of Fading Severity and Receive Antenna Correlation on TAS/MRC under Nakagami Fading

Transmit antenna selection (TAS) is well-known to allow a reduced signal processing complexity while maintaining the diversity order of a MIMO system. Assuming Nakagami fading, we show in this work that antenna correlation in a maximal ratio combining (MRC) receiver, as well as severe fading, have a beneficial impact on ergodic capacity if TAS is used at the transmit end. This is in sharp contrast to MRC reception when a single transmit antenna is considered. We also derive novel closed-form expressions for the average symbol error rate (ASER) of TAS/MRC for different M-ary modulations, generalizing previous works by considering receive antenna correlation where the eigenvalues of the receive correlation matrix have anarbitrary multiplicity. Monte Carlo simulations are performed to validate the analysis. Our results show that, contrary to the behavior of ergodic capacity, antenna correlation and severe fading always have a detrimental impact on ASER for the average SNR values of interest, as in those cases the ASER is dominated by the diversity gain.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech y proyecto Ministerio de Economía y Competividad/FEDER TEC2013-42711-

Thermal rectification in mass-graded next-nearest-neighbor Fermi-Pasta-Ulam lattices

We study the thermal rectification efficiency, i.e., quantification of asymmetric heat flow, of a one-dimensional mass-graded anharmonic oscillator Fermi-Pasta-Ulam lattice both with nearest-neighbor (NN) and next-nearestneighbor (NNN) interactions. The system presents a maximum rectification efficiency for a very precise value of the parameter that controls the coupling strength of the NNN interactions, which also optimizes the rectification figure when its dependence on mass asymmetry and temperature differences is considered. The origin of the enhanced rectification is the asymmetric local heat flow response as the heat reservoirs are swapped when a finely tuned NNN contribution is taken into account. A simple theoretical analysis gives an estimate of the optimal NNN coupling in excellent agreement with our simulation results.J.M.L.thanks Direccion General de Investigación Científica y Técnica, MINECO (Spain) for financial support through the project No. FIS2014-59462-P

Generalized MGF of Beckmann Fading with Applications to Wireless Communications Performance Analysis

The Beckmann distribution is a general multipath fading model for the received radio signal in the presence of a large number of scatterers, which can thence be modeled as a complex Gaussian random variable where both the in-phase and quadrature components have arbitrary mean and variance. However, the complicated nature of this distribution has prevented its widespread use and relatively few analytical results have been reported for this otherwise useful fading model. In this paper, we derive a closed-form expression for the generalized moment-generating function (MGF) of the signal-to-noise ratio (SNR) of Beckmann fading, which permits to circumvent the inherent analytical complexity of this model. This is a new and useful result, as it is key for evaluating several important performance metrics of different wireless communication systems and also permits to readily compute the moments of the output SNR. Thus, we obtain simple exact expressions for the energy detection performance in Beckmann fading channels, both in terms of the receiver operating characteristic (ROC) curve and of the area under ROC curve. We also analyze the outage probability in interference limited systems affected by Beckmann fading, as well as the outage probability of secrecy capacity in wiretap Beckmann fading channels. Monte Carlo simulations have been performed to validate the derived expressions.Universidad de Málaga. Campus de Excelencia Internacional. Andalucía Tech

Analysis and design of a centralized system of optical sources for transmission and reception in access network for 5G support

En el presente documento se propone un sistema pasivo óptico de 20 Gbps, para transmisión y recepción de dos servicios simultáneos en red de acceso, mediante modulación FM y POLMUX como técnica de centralización, aprovechando la polarización ortogonal de componentes magnéticas y eléctricas de un haz de luz coherente para el transporte de la información, brindando acceso a diferentes cantidades de usuarios o unidades de red óptica (ONU's) mediante el análisis del comportamiento de la señal con diferentes longitudes del enlace de fibra óptica y configuraciones en los divisores de polarización de la terminal de línea óptica de transmisión (OLT) .This document proposes a passive optical system of 20 Gbps, for transmission and reception of two simultaneous services in the access network, using FM modulation and POLMUX as a centralization technique, taking advantage of the orthogonal polarization of magnetic and electrical components from a coherent light beam to the transport of information, providing access to different amounts of users or optical network units (ONU's) by analyzing the behavior of the signal with different lengths of the fiber optic link and configurations in the polarization splitters of the optical link terminal (OLT)

Las competencias blandas en el emprendimiento.

El éxito en el mundo de los negocios no solo lo alcanza el sector empresarial mediante el logro de resultados efectivos en las áreas de producción, ventas y finanzas entre otras, todas propias de cualquier actividad académica; tampoco depende exclusivamente de una gestión gerencial organizacional óptima, pues aunque las dos características mencionadas sí constituyen el motor de crecimiento, desarrollo y proyección de una empresa; no garantizan la total supervivencia, rentabilidad y sostenibilidad empresarial en los contextos cambiantes del siglo XXI; pues existen otros factores que contribuyen al logro de dichos postulados

Arquitectura orientada a servicios : principios y fundamentos

SOA es mucho más que una arquitectura de TI, es un nuevo enfoque para las empresas que intentan unir tecnología y negocio. El mercado de este nuevo enfoque ha estado centrado en modelos de integración en donde las empresas aprovechaban la centralización y estandarización de los recursos tecnológicos. Pero esto es un concepto que evoluciona, y por ello, las Arquitecturas Orientadas a Servicios van a experimentar un cambio de paradigma, pasando de un modelo centrado en la integración a un modelo centrado en los procesos de negocio. La arquitectura antes mencionada es por tanto un marco de trabajo para el desarrollo de software y su implantación. Y aunque la mayoría de las definiciones identifican la utilización de Servicios Web (SOA y WSDL) en su implementación, una arquitectura orientada a servicios se puede implementar utilizando cualquier tecnología basada en servicios. La finalidad de la arquitectura es conseguir combinar distintos módulos funcionales para generar aplicaciones de carácter específico, proviniendo todos de servicios preexistentes, cuanto mayor sea la funcionalidad proporcionada por estos módulos, menor será el número de interfaces necesarios para alcanzar el objetivo deseado y cada interfaz conlleva un gasto de procesamiento adicional; sin embargo, cuando los módulos son excesivamente grandes resulta complicada su reutilización. Consecuentemente es necesario alcanzar el nivel de granulación adecuado. La expectativa creada por esta nueva arquitectura es que el coste marginal de creación de la enésima aplicación sea cero dado que el software requerido se encontrará ya disponible para satisfacer los requisitos; tan sólo se requerirá la coordinación entre los elementos.Incluye bibliografí

TRIBUNAL ARBITRAL DE SCHRADER CAMARGO INGENIEROS ASOCIADOS S.A. VS. REFINERÍA DE CARTAGENA S.A.- REFICAR

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METODOS GEOFISICOS APLICADOS A LA DE CELDAS ACTIVAS Y CLAUSURADAS DEL RELLENO SANITARIO "LA CORTADA" (NORTE DE SANTANDER)

En este trabajo se presenta una aplicación de algunas técnicas geofísicas no invasivas para la caracterización del relleno sanitario regional “La Cortada”, el cual se encuentra ubicado a 5 km del Municipio de Pamplona, en la Vereda la Chichira (Norte de Santander). Los métodos geofísicos aplicados en este estudio fueron; la Tomografía de Refracción Sísmica (TRS) y la Tomografía de Resistividad Eléctrica (TRE). A partir de estas técnicas se pueden determinar algunas propiedades como la resistividad eléctrica y la velocidad sísmica tipo P. El objetivo de este estudio fue identificar o delimitar la geometría del relleno sanitario específicamente de la zona de contacto entre los materiales de desecho y la roca fresca. Se adquirieron datos para 5 líneas de TRS, y 5 líneas de TRE en zonas activas y clausuradas del relleno sanitario. Este trabajo abarcó etapas de diseño, adquisición, procesamiento e interpretación de estos datos geofísicos. A través del análisis de los resultados en este trabajo, se obtuvieron anomalías de la resistividad eléctrica en sectores de las zonas activas y clausuradas que pueden estar asociadas a acumulación de contaminantes, también se obtuvo un rango de velocidades sísmicas de ondas P para los residuos sólidos y de la roca fresca. Finalmente, se comprobó que estas técnicas son útiles en la caracterización de este tipo de depósitos logrando evidenciar contrastes entre las propiedades físicas