Evaluating pointing errors on ergodic capacity of DF relay-assisted FSO communication systems

Ergodic capacity of decode-and-forward (DF) relay-assisted free-space optical (FSO) communication systems when line of sight is available is analyzed over gamma-gamma fading channels with pointing errors. Novel closed-form approximate ergodic capacity expression is obtained in terms of the H-Fox function for a 3-way FSO communication system when the α-μ distribution to efficiently approximate the probability density function (PDF) of the sum of gamma-gamma with pointing errors variates is considered. Moreover, we present a novel asymptotic expression at high signal-to-noise ratio (SNR) for the ergodic capacity of DF relay-assisted FSO systems. The main contribution in this work lies in an in-depth analysis about the impact of pointing errors on the ergodic capacity for cooperative FSO systems. In order to maintain the same performance in terms of capacity, it is corroborated that the presence of pointing errors requires an increase in SNR, which is related to the fraction of the collected power at the receive aperture, i.e. A 0 . Simulation results are further demonstrated to confirm the accuracy and usefulness of the derived results.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech. The authors wish to acknowledge the financial support given by Spanish MINECO Project TEC2012-32606

La conservación de bienes culturales muebles en El Salvador: una tarea por hacer

La conservación y restauración ha tomado un lugar preponderante para la cultura en todo el mundo. Desde la antigüedad, y más específicamente desde la época medieval, el renacimiento o el barroco, se aplicaban prácticas para la conservación de edificios, pinturas murales, esculturas y pinturas con un enfoque de prevención del deterioro. La institución responsable de recolectar, estudiar, conservar y exhibir el patrimonio cultural que forma sus colecciones es el museo, en cualquiera de sus expresiones. La actividad de mayor responsabilidad que se deriva es la conservación, ya que sin obras en buen estado no existen materiales para exhibir.Universidad Tecnológica de El Salvado

El proceso de revisión del Concordato de 1953.

Material incluido en el volumen especial de la revista del Instituto Martín de Azpilcueta, Universidad de Navarra : Ius Canonicum (1999), en honor de Javier Hervada

Effects of heat and burning on testing methods for blood and semen

Thesis (M.S.)--Boston UniversityPerpetrators of crime may sometimes attempt to destroy links that connect them to the crime scene. Limited information is known about the appearance and behavior of blood or semen stains collected from fire scenes. The purpose of this study is to observe the effects of high temperatures and flame exposure on blood and semen stains using current traditional presumptive (phenolphthalein, AP Spot test and ALS fluorescence) and confirmatory (ABAcard® Hematrace®, microscopic identification of spermatozoa and RSIDTM-Semen) testing methods. Liquid blood and semen was applied to swatches of denim, synthetic leather and carpet, and allowed to dry. In Part I of this study, the stains were exposed for various amounts of time to 130°C, 150°C, 170°C and 190°C using a laboratory oven. When bloodstains were exposed to high temperatures, 
 reaction times using phenolphthalein increased and only bloodstains on denim were undetected within one minute at the most extreme conditions. Scraping was determined to be a better collection method than swabbing to test samples exposed to higher temperatures, and some samples required longer than the typical 10-15 second time frame used by most forensic labs to yield a positive reaction. Detection of human hemoglobin using ABAcard® Hematrace® was not possible after 1 hour at 130°C, making it a less sensitive test for bloodstains exposed to high temperatures than phenolphthalein. Semen stains exhibited fluorescence using an alternate light source after limited exposure to all temperatures, but more successfully on denim and synthetic leather than on carpet. AP Spot test was successful on all semen stains on synthetic leather, and on a number of samples on denim and carpet. Microscopic identification of sperm was most successful on denim but became impossible at higher temperatures and exposure times. Semenogelin testing was most successful on carpet and could be detected even under the most extreme conditions. Additionally, as temperature increased, semen stains darkened in color and appeared visually similar to bloodstains. [TRUNCATED

Análisis de recursos online en inglés para niños: un caso práctico con una propuesta de plantilla de evaluación

Internet provides us, as teachers, with a wide range of tools and resources for practising English in an online environment. However, due to the vast amount of digital resources at our disposal today, and taking into account that not everything found on the net is reliable, we have no other option but to evaluate the resources. On the other hand, on the net we can find several already-created templates for analysing online resources. But, quite often, most of these templates include many indicators that will make the task of evaluating more time consuming, or do not include indicators for assessing the adequacy of the site as far as level, theme and linguistic skills of a foreign language, in our case, English, are concerned. The purpose of this paper is to propose a template enabling ESL or EFL teachers to gather suitable information per online resource and also to analyse some real sites in accordance with the parameters and indicators of the template.Internet nos ofrece a los docentes una gran variedad de herramientas y recursos para practicar inglés en un entorno online. Sin embargo, debido a la gran cantidad de recursos digitales que están a nuestra disposición, y teniendo en cuenta que no todo lo que se encuentra en la red es fiable, no tenemos otra opción que evaluar nosotros mismos estos recursos. Por otro lado, en la red podemos encontrar plantillas creadas para analizar recursos online. Pero, a menudo, muchas de estas plantillas incluyen muchos indicadores que requieren mucho tiempo para su evaluación o bien no contemplan indicadores para evaluar la idoneidad del recurso en lo que respecta a nivel, temática y destrezas lingüísticas de una lengua extranjera, en nuestro caso, inglés. El objetivo de este artículo es proponer una plantilla que posibilite a los docentes de inglés como segunda lengua/lengua extranjera reunir suficiente información de cada recurso digital y analizar también algunos recursos reales de acuerdo con los parámetros e indicadores propuestos en la plantilla

Estrategias de branding para posicionamiento de marca : "Roland Novedades", María Auxiliadora, Py

La investigación aborda el desarrollo de estrategias de branding online y offline para posicionamiento de marca de la empresa Roland Novedades. La empresa, es unipersonal de tipo familiar dedicada a la comercialización de prendas de vestir y calzados, para damas caballeros y niños en la localidad de Tomás Romero Pereira, teniendo gran impacto en el desarrollo de la región, pues la misma aporta impuestos que contribuyen al país, asimismo ofrece oportunidad laboral a los ciudadanos. El branding o la creación y gestión de marca es un proceso integrativo, que busca construir marcas poderosas; es decir, marcas ampliamente conocidas, asociadas a elementos positivos, deseadas y compradas por una base amplia de consumidores. Se presenta y desarrolla el branding como una técnica que puede ser adaptada a las empresas, marcas, personas y lugares. En este caso, es abordado en función a una marca-empresa del mercado de María Auxiliadora de manera a lograr el posicionamiento de la misma y posteriormente su reconocimiento. La investigación es de tipo documental y de campo, enfoque o paradigma, mixto y de alcance descriptivo. Los instrumentos de recolección de datos fueron la encuesta mediante cuestionarios a clientes y entrevistas a propietarios y competidores. Los resultados obtenidos sirven de base para analizar las estrategias de branding necesarias para la empresa Roland Novedades, los cuales fueron contrastados con la teoría investigada para que el análisis cobrara mayor relevancia. Se determinan las estrategias necesarias, mediante el desarrollo de un Plan de Posicionamiento de Marca. El aporte: brindar propuestas y recomendaciones que sirvan de base para la toma de decisiones, realizar ajustes, innovar, posicionar la marca en el mercado.Fil: Flores, Beatriz. Universidad Nacional de Itapúa (Paraguay)Fil: Castillo, Beatriz. Universidad Nacional de Itapúa (Paraguay

Que associações automáticas prevalecem? Efeitos de priming de congruência e inverso em estereotipia de género implícita

Objectives. This study aimed to test whether gender stereotypes remain automatically activated following cues related to gender, despite years of promoting equality, and how it could correspond with explicit measures. Method. Seventy undergraduates performed a sequential priming task, in which the gender categories were presented subliminally. Culturally specifi c gender stereotypes were used as targets. In addition, other signifi cant variables related to gender (self-assignment of stereotypes, identity and ideology) were assessed explicitly. Results. At fi rst, the results showed a non-priming effect, indicating no implicit gender stereotyping. However, a more detailed observation of the data revealed that participants could be differentiated according to the effects that appeared: the congruency and the reverse priming effects. Conclusion. While gender stereotypes were automatically activated in Group 1 (positive socres), implicit stereotype inhibition seemed to take place in Group 2 (negative scores). Egalitarian goal activation is assumed to explain the reverse effect. The activation of different contents from the same primes emphatically suggests that more effort is needed to develop strong egalitarian commitments. Results also support the potential dynamic of gender stereotypes, even at an implicit level.Objetivos. Evaluar si los estereotipos de género continúan activándose automáticamente tras presentar claves relacionadas con el género, y cómo esta activación se correspondería con medidas explícitas. Método. Setenta estudiantes universitarios realizaron una tarea de priming secuencial en la que se presentaron subliminalmente los primes mujer y hombre (categorías de género). Los targets fueron estereotipos de género culturalmente signifi cativos. Además, otras variables relacionadas con el género (autoasignación de estereotipos, identidad e ideología) se evaluaron explícitamente. Resultados. En un principio, los resultados no mostraron ningún efecto de priming, señalando la ausencia de estereotipia de género implícita. Sin embargo, una inspección más detallada de los datos reveló que los participantes podían diferenciarse según los diferentes efectos que habían aparecido: congruencia e inverso. Conclusión. Mientras que en el Grupo 1 (puntajes positivos) los estereotipos de género se activaron automáticamente, en el Grupo 2 (puntajes negativos) se produjo una inhibición implícita de estereotipos. La activación de una meta igualitaria podría explicar el efecto inverso. La activación de contenidos diferentes derivada de los mismos primes enfatiza la necesidad de realizar más esfuerzos para desarrollar compromisos igualitarios fi rmes. Los resultados también apoyan la potencial dinámica de los estereotipos de género, incluso a nivel implícito.Escopo. Avaliar se os estereótipos de género continuam se ativando automaticamente depois de presentar claves relacionadas com o género, e como esta ativação pode se corresponder com medidas explícitas. Metodologia. Setenta estudantes realizaram uma tarefa de priming sequencial na que se apresentaram subliminarmente os primes mulher e homem (categorias de género). Os objetivos foram estereótipos de gênero culturalmente signifi cativos. Além, outras variáveis relacionadas com o género (auto-alocação de estereótipos, identidade e ideologia) foram avaliadas explicitamente. Resultados. Num principio, os resultados não mostraram efeito nenhum de priming, assinalando a ausência de estereotipia de gênero implícita. No entanto, uma inspeção mais detalhada dos dados revelou que os participantes podiam ser diferenciados segundo os efeitos diferentes que tinham aparecido: congruência e inverso. Conclusão. Enquanto que no grupo 1 (contagens positivas) os estereótipos de gênero foram ativados automaticamente, no Grupo 2 (contagens negativas) foi produzida uma inibição implícita de estereótipos. A ativação de uma meta igualitária pode explicar o efeito inverso. A ativação de conteúdos diferentes derivada dos mesmos primes enfatiza a necessidade de fazer mais esforços para desenvolver compromissos igualitários fi rmes. Os resultados também apoiam a potencial dinâmica dos estereótipos de gênero, mesmo no nível implícito

Impact of nonzero boresight pointing error on ergodic capacity of MIMO FSO communication systems

A thorough investigation of the impact of nonzero boresight pointing errors on the ergodic capacity of multiple-input/multiple-output (MIMO) free-space optical (FSO) systems with equal gain combining (EGC) reception under different turbulence models, which are modeled as statistically independent, but not necessarily identically distributed (i.n.i.d.) is addressed in this paper. Novel closed-form asymptotic expressions at high signal-to-noise ratio (SNR) for the ergodic capacity of MIMO FSO systems are derived when different geometric arrangements of the receive apertures at the receiver are considered in order to reduce the effect of nonzero inherent boresight displacement, which is inevitably present when more than one receive aperture is considered. As a result, the asymptotic ergodic capacity of MIMO FSO systems is evaluated over log-normal (LN), gamma-gamma (GG) and exponentiated Weibull (EW) atmospheric turbulence in order to study different turbulence conditions, different sizes of receive apertures as well as different aperture averaging conditions. It is concluded that the use of single-input/multiple-output (SIMO) and MIMO techniques can significantly increase the ergodic capacity respect to the direct path link when the inherent boresight displacement takes small values, i.e. when the spacing among receive apertures is not too big. The effect of nonzero additional boresight errors, which is due to the thermal expansion of the building, is evaluated in multiple-input/single-output (MISO) and single-input/single-output (SISO) FSO systems. Simulation results are further included to confirm the analytical results.The authors are grateful for financial support from the Junta de Andalucía (research group Communications Engineering (TIC-0102))

Novel approximation of misalignment fading modeled by Beckmann distribution on free-space optical links

A novel accurate and useful approximation of the well-known Beckmann distribution is presented here, which is used to model generalized pointing errors in the context of free- space optical (FSO) communication systems. We derive an approximate closed form probability density function (PDF) for the composite gamma-gamma (GG) atmospheric turbulence with the pointing error model using the proposed approximation of the Beckmann distribution, which is valid for most practical terrestrial FSO links. This approximation takes into account the effect of the beam width, different jitters for the elevation and the horizontal displacement and the simultaneous effect of nonzero boresight errors for each axis at the receiver plane. Additionally, the proposed approximation allows us to delimit two different FSO scenarios. The first of them is when atmospheric turbulence is the dominant effect in relation to generalized pointing errors, and the second one when generalized pointing error is the dominant effect in relation to atmospheric turbulence. The second FSO scenario has not been studied in-depth by the research community. Moreover, the accuracy of the method is measured both visually and quantitatively using curve-fitting metrics. Simulation results are further included to confirm the analytical results.Junta de Andalucía (research group "Communications Engineering (TIC-0102)") and Universidad de Málaga