CA-CFAR Adjustment Factor Correction with a priori Knowledge of the Clutter Distribution Shape Parameter

Oceanic and coastal radars operation is affected because the targets information is received mixed with and undesired contribution called sea clutter. Specifically, the popular CA-CFAR processor is incapable of maintaining its design false alarm probability when facing clutter with statistical variations. In opposition to the classic alternative suggesting the use of a fixed adjustment factor, the authors propose a modification of the CA- CFAR scheme where the factor is constantly corrected according on the background signal statistical changes. Mathematically translated as a variation in the shape parameter of the clutter distribution, the background signal changes were simulated through the Weibull, Log-Normal and K distributions, deriving expressions which allow choosing an appropriate factor for each possible statistical state. The investigation contributes to the improvement of radar detection by suggesting the application of an adaptive scheme which assumes the clutter shape parameter is known a priori. The offered mathematical expressions are valid for three false alarm probabilities and several windows sizes, covering also a wide range of clutter conditions

César Vallejo en la poesía de Joaquín Vásquez Aguilar

Artículo número 6 de la Sección Variaciones. 12 páginas. tyvlliiiTras ser ignorado por la crítica, en 2010 Joaquín Vásquez Aguilar es rescatado por la Universidad Autónoma de Chiapas y el coneculta, con la publicación de El pico de la garza más blanca. Obra reunida y Poesía reunida. En este ensayo se reflexiona sobre las características de su poesía, la cual abreva de su infancia en la costa chiapaneca. En algunos poemas usa un lenguaje coloquial; en otros, los de clara influencia de César Vallejo, apuesta por la desautomatización del lenguaje y la experimentación formal. Sus temáticas siempre buscan la belleza de las cosas simples, elementales.After being ignored by critics, in 2010 Joaquín Vásquez Aguilar is rescued by the Autonomous University of Chiapas and coneculta, with the publication of El pico de la garza más blanca. Obra reunida and Poesía reunida. This article reflects on the characteristics of his poetry, which always refers to his childhood on the coast of Chiapas. In some poems he uses a colloquial language; in others, those of clear influence of César Vallejo, bet on the deautomatization of language and formal experimentation. His themes always look for the beauty of simple and elementary things

Identification of Influencers in eWord-of-Mouth communities using their Online Participation Features

[EN] The identification of influencers in any type of online social network is of paramount importance, as they can significantly affect consumers’ purchasing decisions. This paper proposes the utilization of a self-designed web scraper to extract meaningful information for the identification of influencers and the analysis of how this new set of variables can be used to predict them. The experimental results from the Ciao UK website will be used to illustrate the proposed approach and to provide new insights in the identification of influencers. Obtained results show the importance of the trust network, but considering the intensity and the quality of both trustors and trustees.Olmedilla, M.; Arenas-Márquez, FJ.; Martinez-Torres, MR.; Toral, SL. (2016). Identification of Influencers in eWord-of-Mouth communities using their Online Participation Features. En CARMA 2016: 1st International Conference on Advanced Research Methods in Analytics. Editorial Universitat Politècnica de València. 38-45. https://doi.org/10.4995/CARMA2016.2016.3642OCS384

Hyperbolicity of direct products of graphs

It is well-known that the different products of graphs are some of the more symmetric classes of graphs. Since we are interested in hyperbolicity, it is interesting to study this property in products of graphs. Some previous works characterize the hyperbolicity of several types of product graphs (Cartesian, strong, join, corona and lexicographic products). However, the problem with the direct product is more complicated. The symmetry of this product allows us to prove that, if the direct product G(1) x G(2) is hyperbolic, then one factor is bounded and the other one is hyperbolic. Besides, we prove that this necessary condition is also sufficient in many cases. In other cases, we find (not so simple) characterizations of hyperbolic direct products. Furthermore, we obtain good bounds, and even formulas in many cases, for the hyperbolicity constant of the direct product of some important graphs (as products of path, cycle and even general bipartite graphs).This work was supported in part by four grants from Ministerio de Economía y Competititvidad (MTM2012-30719, MTM2013-46374-P, MTM2016-78227-C2-1-P and MTM2015-69323-REDT), Spain

Estrés académico y ansiedad en estudiantes del décimo ciclo de enfermería de una universidad privada de Lima,2023

The objective of this study was: To analyze how academic stress is related to anxiety in tench cycle nursing students of a private university in Lima, 2023. Methodology: The method was hypothetical deductive, quantitative approach, applied type research, correlational design. The population was 123 students and the sample consisted of 93 students. The technique for data collection was the survey, and the instrument was the questionnaire. The questionnaires SISCO SV-21 for academic stress and the C. Spielberg Anxiety Rating Scale for anxiety Rating Scale for anxiety were applied. The results showed that 36.6% of students presented moderate stress with moderate anxiety; in the stressors dimension of academic stress with anxiety there is moderate stress with moderate anxiety in 31.2; in the symptoms dimension of academic stress with anxiety they presented moderate stress with moderate anxiety in 34.4%; and in the coping strategies dimension of academic stress with anxiety they presented moderate stress and moderate anxiety in 29.0%. It was concluded that academic stress and anxiety present a negative correlation (Rho= -.090) and (Sig. = .393) that is, there is no statistically significant relationship.Este estudio tuvo como Objetivo: Analizar cómo el estrés académico se relaciona con la ansiedad en estudiantes del décimo ciclo de enfermería de una universidad privada de Lima, 2023. Metodología: El método fue hipotético deductivo, enfoque cuantitativo, investigación de tipo aplicada, diseño correlacional. La Población fue 123 estudiantes y su muestra estuvo conformada por 93 estudiantes. La técnica para la recolección de datos fue la encuesta, y para instrumento fue el cuestionario. Se aplicó los cuestionarios SISCO SV-21 para el estrés académico y para la ansiedad la Escala de Valoración de la Ansiedad de C. Spielberg. Los resultados mostraron que el 36.6% de estudiantes presentaron estrés moderado con ansiedad moderado; en la dimensión estresores del estrés académico con la ansiedad existe estrés moderado con ansiedad moderado en 31.2%; en la dimensión síntomas del estrés académico con ansiedad presentaron estrés moderado con ansiedad moderado en 34.4%; y en la dimensión estrategias de afrontamiento del estrés académico con ansiedad presentaron estrés moderado y ansiedad moderado en 29.0%. Se concluyó que el estrés académico y la ansiedad presentan una correlación negativa (Rho= -.090) y (Sig. = .393), es decir no existe relación estadísticamente significativa

Un software FOSS para la gestión de las fotografías obtenidas por fototrampeo

La constante innovación tecnológica y al abaratamiento de los dispositivos, han hecho que el fototrampeo se convierta en una técnica ampliamente utilizada para la realización de inventarios biológicos, generando gran cantidad de registros de alto interés ecológico. El principal objetivo de esta comunicación es presentar una herramienta de software libre (FOSS), desarrollada para facilitar el manejo de datos, obtenidos mediante fototrampeo en un espacio protegido de la Comunidad Valenciana. Así, a partir de un estudio iniciado en 2009, se ha analizado la composición de la comunidad de vertebrados en el Parque Natural de la Sierra de Mariola. Para la realización de los muestreos se han empleado cámaras de infrarrojos con sensor de movimiento (Moultrie Game Spy I-60®), obteniendo un total de 29,941 contactos que han servido para determinar la abundancia de las especies muestreadas en las 63 cuadrículas (2*2 Km) establecidas en la zona de estudio. La aplicación FOSS, denominada “Camera Trap Manager”, se ha diseñado para agilizar el tratamiento de esta información y funciona sobre la plataforma .NET, pudiendo ser utilizada en varios sistemas operativos. Además, este software dispone de un interfaz de usuario muy intuitivo, capacidad de extraer automáticamente distintos tipos de metadatos (fecha, hora, fase lunar, localización, temperatura, presión atmosférica, etc), basados en el estándar Exif; disponibilidad de listas taxonómicas para permitir a los usuarios etiquetar fácilmente las imágenes con las identidades de las especies, capacidad de análisis y creación de informes. El uso de esta aplicación ha permitido simplificar el procesado, análisis y edición de datos, consiguiendo una significativa reducción de los costes económicos y temporales. Mientras que en el procesado manual se alcanzaba una media de 55 fotografías/hora, el uso de esta herramienta permite procesar más de 1,000 fotografías/hora, obteniendo una mayor cantidad de información. Finalmente, se pone de manifiesto la gran utilidad de esta aplicación, que puede ser adaptada a las necesidades de otros proyectos de gestión de fauna, haciendo su uso extensivo no solamente a los profesionales del sector, sino a todos aquellos que requieran procesar gran cantidad de imágenes de fototrampeo

EFECTO DE DECOLORACIÓN POR PLASMA NO TÉRMICO EN COLORANTES TEXTILES DISUELTOS: NEGRO ÁCIDO 194

Artículo de investigaciónIn this work, we show that cold plasma (electrical discharge) acting on the liquidatmosphere interface can change some macroscopic and microscopic parameters of wastewater with dissolved dyes, a process characterized by the study of physical and chemical variables, such as the voltage and current of the electrical discharge, temperature, volume, absorbance, electrical conductivity, pH, chemical oxygen demand (COD), and total organic carbon (TOC). The dye used is Acid Black 194 (AB194) in a water solution (250 mL) with a concentration of 0.1 mM and the addition of FeSO4 at 1.0 mM. The initial values of pH and electrical conductivity were 2.54 and 1.55 S/cm, respectively, at a temperature of 21.5 ºC. Nonthermal plasma was generated with a DC power supply at a potential of 700 V and 133 mA, which was maintained throughout the process, until an exposure time of 45 min. This physicochemical method is environmentally friendly because it does not generate polluting waste.UAEM 4307/2017/CI

Carbon nanotubes as catalysts for wet peroxide oxidation: The effect of surface chemistry

Three magnetic carbon nanotube (CNT) samples, named A30 (N-doped), E30 (undoped) and E10A20 (selectively N-doped), synthesized by catalytic chemical vapor deposition, were modified by introducing oxygenated surface groups (oxidation with HNO3, samples CNT-N), and by heat treatment at 800 °C for the removal of surface functionalities (samples CNT-HT). Both treatments lead to higher specific surface areas. The acid treatment results in more acidic surfaces, with higher amounts of oxygenated species being introduced on Ndoped surfaces. Heat-treated samples are less hydrophilic than those treated with nitric acid, heat treatment leading to neutral or basic surfaces, only N-quaternary and N-pyridinic species being found by XPS on N-doped surfaces. These materials were tested in the catalytic wet peroxide oxidation (CWPO) of highly concentrated 4-nitrophenol solutions (4-NP, 5 g L−1) at atmospheric pressure, T=50 °C and pH=3, using a catalyst load of 2.5 g L−1 and the stoichiometric amount of H2O2 needed for the complete mineralization of 4-NP. The high temperature treatment enhanced significantly the activity of the CNTs towards CWPO, evaluated in terms of 4-NP and total organic carbon conversion, due to the increased hydrophobicity of their surface. In particular, E30HT and E10A20HT were able to remove ca. 100% of 4-NP after 8 h of operation. On the other hand, by treating the CNTs with HNO3, the activity of the less hydrophilic samples decreased upon increasing the concentration of surface oxygen-containing functionalities, whilst the reactivity generated inside the opened nanotubes improved the activity of the highly hydrophilic A30 N.This work is a result of project “AIProcMat@N2020 - Advanced Industrial Processes and Materials for a Sustainable Northern Region of Portugal 2020”, with the reference NORTE-01-0145-FEDER-000006, supported by NORTE 2020, under the Portugal 2020 Partnership Agreement, through the ERDF and of Project Associate Laboratory LSRE-LCM - UID/EQU/50020/2019 - funded by national funds through FCT/MCTES (PIDDAC). M. Martín Martínez acknowledges the postdoc grant 2017-T2/AMB-5668 from Comunidad de Madrid, Programme “Atracción de talento investigador”. B. Machado acknowledges the exploratory project under FCT Investigator Programme (ref. IF/00301/ 2015) with the financial support of FCT/MCTES through national funds (PIDDAC). S. Morales Torres acknowledges the financial support from University of Granada (Reincorporación Plan Propio).info:eu-repo/semantics/publishedVersio

Canales y márgenes de comercialización de caprinos en Tejupilco y Amatepec, estado de México

Con el objetivo de analizar los canales y márgenes de comercialización de la carne de caprino, se realizó una investigación en los municipios de Tejupilco y Amatepec, Estado de México durante 2004-2005. Se determinó el canal de comercialización más utilizado por los agentes participantes de dicho mercado y se calcularon los márgenes absolutos y relativos, a través de la obtención de sus valores equivalentes y de los costos y ganancias de cada agente participante. De 133 productores entrevistados, 96.5% realiza la venta en pie. El productor obtuvo 46.5% del precio real que pagó el consumidor final por kilogramo de carne cruda y el intermediario 53.5%. Considerando la birria como producto final, el productor alcanzó 20.42% de las ganancias de todo el proceso y los intermediarios 79.58%; los birrieros obtuvieron la mayor parte (79.58%) del margen total de comercialización. El canal de comercialización más común fue productor, acopiador regional, birriero y consumidor final. Se concluye que el birriero obtuvo las mayores relaciones beneficio costo (8.86 y 8.61)

Carbon nanotubes as catalysts for wet peroxide oxidation: structure-reactivity relationships

Magnetic neat and N-doped carbon nanotubes with different properties have been synthesized by chemical vapour deposiüon and tested in the catalytic wet peroxide oxidation of 4-nitrophenol solutions (5 g L') at relatively mild operating conditions (atmospheric pressure, T = 50 °C, pH = 3)~using a catalyst load = 2.5 g L-' and [H202]o = 17.8 g L-1. The results demonstrate that the catalyst hydrophobicity/ hydrophilicity is a detenninant property in the CWPO reaction, since it affects the rate ofH202 decomposition. The controlled formation ofreactive radicais (HO* and HOO*) at hydrophobic surfaces avoids the formation of non-reactive species (02 and H20), increasing