Performance evaluation of space-time block coding using a realistic mobile radio channel

This paper presents a performance evaluation of space-time block coding (STBC) employing a realistic mobile radio channel model in macrocellular and urban environments. The bit error rate (BER) is computed by Monte-Carlo simulations in the down-link to evaluate its sensitivity to channel correlation. We consider a horizontal uniform linear array at the base station (BS) formed by up to four antenna elements, and one and two uncorrelated antenna elements at the mobile station (MS). The channel model includes the probability density function (pdf) of the azimuth and delay of the impinging waves and their expected power conditioned on the azimuth and delay. The statistical properties of the model are extracted from macrocellular measurements made in urban environments. Simulation results show that the use of STBC can provide significant gains with acceptable sensitivity to the channel correlation under realistic conditions.Peer ReviewedPostprint (published version

Multi-instance learning with application to the profiling of multi-victim homicides

Altres ajuts: acords transformatius de la UABHomicide involving multiple victims has a significant negative effect on society. Criminal profiling consists of determining the traits of an unknown offender based on those of the crime and the victims, with a view to their identification. To provide the most likely profile of the perpetrator of a multi-victim homicide, we propose a predictive model of supervised machine learning based on a Bayesian Network. Conventional classifiers can generate the perpetrator's profile according to the traits of each of the victims of the same homicide, but the profiles may differ from one another. To address this issue, we consider the Multi-Instance (MI) learning framework, in which the victims of the same incident form a bag, and each bag is associated with a unique label for each of the perpetrator's features. We introduce the unanimity MI assumption in this domain, and accordingly allocate a label to the bag based on the labels and probabilities the Bayesian Network has assigned its instances, using a combination rulefrom those of the ensemble of classifiers. We apply this methodology to the Federal Bureau of Investigation (FBI) homicide database to compare three combination rules empirically in the validation process, as well as theoretically, using the one that ultimately proves to be the best to build the final model, which is then applied in some illustrative examples to achieve the criminal profile. PID2021-123733NB-I0

Modelo de software para el análisis de riesgo de inundación utilizando el enfoque sistématico, caso: Valle de Chalco Solidaridad

Para la realización del modelo fue necesario identificar las causas sistémicas de una inundación y todos los componentes principales que la conforman, además particularmente -y por ser motivo de esta tesis- la inundación del 5 de febrero de 2010 en Valle de Chalco Solidaridad. Se caracterizaron las causas sistémicas de la inundación que ahí tuvo efecto y después se obtuvo propiamente el modelo de software para el análisis de riesgo de inundación, para posteriormente diseñar y validar los experimentos realizados

O lazer no quotidiano dos estudantes: de educação secundária em Espanha

Partiendo de la interrelación existente entre la educación cultural de las personas y el uso que hacen de sus tiempos cotidianos, en el artículo se pone de manifiesto la relevancia que tiene el ocio en el desarrollo humano. Más aún cuando nos referimos a adolescentes y jóvenes que, dada la realidad socio familiar que les ha venido impuesta, ven condicionada la satisfacción de muchas de las necesidades básicas que favorecen una vida de y con calidad, en cuyo logro el derecho al ocio adquiere un protagonismo clave. En este sentido, se presentarán parte de los resultados de un proyecto de investigación, cuyo objetivo principal residía en conocer e interpretar cómo inciden los tiempos escolares en los procesos de socialización adolescente y juvenil, así como en los modos de configurar su tiempo libre. Más en concreto: se analizarán algunos de los datos obtenidos en un cuestionario diseñado ad hoc y aplicado a una muestra de 3.306 alumnos/as de entre 12 y 17 años que cursaban Educación Secundaria Obligatoria (ESO) en centros educativos de la geografía española en el curso académico 2010-2011. Conocer la utilización que hace este colectivo de sus tiempos, tiene para nosotros en este artículo una doble finalidad: reflexionar en qué medida las actividades que realizan favorecen la adquisición de aprendizajes de carácter cultural; indagar si existe alguna relación significativa entre la edad, el contexto familiar y las actividades que llevan a cabo.Considering the interrelation between people’s cultural education and how they use their daily time, this article highlights the relevance of leisure time in human development. Especially when we refer to the group of young people who, given the social and familial reality that has been imposed to them, feels limitations in what concerns the satisfaction of their basic needs, among them enjoying a leisure time that favors their quality of life. In this sense, we present some results of a research project carried out on Spanish territory and whose main objective was to learn and interpret how time in school is reflected in students’ socialization process, as well as how they configure leisure time. The data were obtained by a questionnaire designed ad hoc that was applied to a sample of 3.306 youth, from 12 to 17 years, who attended Secundary Education (ESO)3 in Spanish High Schools in the academic year of 2010-2011. Our intention is to know how students spend their time, with two purposes: reflecting about the extent to which their activities favor the acquisition of cultural learning cultural, and whether there is any significant relationship between age and type of recreational activities they undertake.Partindo da inter-relação entre a educação cultural das pessoas e o uso que fazem dos seus tempos quotidianos, este artigo evidencia a relevância que têm os tempos de lazer no desenvolvimento humano. Especialmente quando nos referimos ao grupo de adolescentes e jovens que, dada a realidade sociofamiliar que lhes tem sido imposta, vê condicionada a satisfação de muitas das necessidades básicas que possibilitam uma vida de e com qualidade, na qual o direito ao lazer adquire um protagonismo chave. Neste sentido, serão apresentados parte dos resultados de um projeto de investigação cujo objetivo principal era conhecer e interpretar os modos como configuram os seus tempos livres e como os tempos escolares se refletem nos processos de socialização adolescente e juvenil. Concretamente, serão analisados alguns dos dados obtidos pelo questionário desenhado ad hoc e aplicado a uma amostra de 3.306 jovens com 12 e 17 anos que frequentavam a Educación Secundaria Obligatoria (ESO) nos centros educativos do território espanhol no curso académico de 2010-2011. Conhecer a utilização que os adolescentes e jovens fazem dos seus tempos tem uma dupla finalidade: refletir em que medida as atividades que realizam favorecem a aquisição de aprendizagens de caráter cultural; questionar se existe alguma relação significativa entre a idade e as atividades que realizam

Towards a complete Binary Key System for the Speaker Diarization Task

International audienceSpeaker diarization is the task of partitioning an audio stream into homogeneous segments according to speaker identity. Today state-of-the-art speaker diarization systems have achieved very competitive performance. However, any small improvement in Diarization Error Rate (DER) is usually subject to very large processing times (real time factor above one), which makes systems not suitable for some time-critical, real-life applications. Recently, a novel fast speaker diarization technique based on speaker modeling using binary keys was presented. The proposed technique speeds up the process up to ten times faster than real-time with little increase of DER. Although the approach shows great potential, the presented results are still preliminary. The goal of this paper is to further investigate this technique, in order to move towards a complete binary-key based system for the speaker diarization task. Preliminary experiments in Speech Activity Detection (SAD) based on binary keys show the feasibility of the binary key modeling approach for this task. Furthermore, the system has been tested on two different kinds of test data: meeting audio recordings and TV shows. The experiments carried out on NIST RT05 and REPERE databases show promising results and indicate that there is still room for further improvement

Estudio metalúrgico de causas de falla del puente pescadero

Se trata de un puente en arco de una sola luz de 120 m, el cual colapsó después de 10 años de servicio. Con base en elementos estructurales extraídos del puente de falla, se realizó un estudio fractográfico, mecáni co y químico, con el fin de establecer las posibles causas de fallas del puente desde el punto de vista metalúrgico. En nudos de unión de pendolón-arco se observan fracturas por fatiga en uniones soldadas en varios sitios, lo cual es evidenciado por una apariencia de fractura suave de crecimiento estable de grietas combinada con una zona de apariencia fibrosa de fractura súbita final de colapso del puente. Dado que el colapso del puente es precedido por la generación de grietas en uniones soldadas, se considera importante examinar la combinación de las propiedades de resistencia y tenacidad con el fin de estudiar tanto la capacidad de soporte de carga como de la tolerancia de defectos de las uniones soldadas

Speaker diarization and speech recognition in the semi-automatization of audio description : an exploratory study on future possibilities?

This article presents an overview of the technological components used in the process of audio description, and suggests a new scenario in which speech recognition, machine translation, and text-to-speech, with the corresponding human revision, could be used to increase audio description provision. The article focuses on a process in which both speaker diarization and speech recognition are used in order to obtain a semi-automatic transcription of the audio description track. The technical process is presented and experimental results are summarizedEste artículo presenta una visión panorámica de los componentes tecnológicos usados en el proceso de audiodescripción y propone un nuevo escenario en el que se aplicarían el reconocimiento de habla, la traducción automática y la síntesis de habla, con su correspondiente revisión humana, para incrementar la cantidad de audiodescripciones disponibles. El artículo describe un proceso en el que la diarización y el reconocimiento de habla permiten obtener una transcripción semiautomática de la audiodescripción. El artículo presenta detalladamente el proceso técnico así como un resumen de los resultados experimentales.- In a second languag

Ampliación del sistema de comunicación interno en una empresa

Este Trabajo de Fin de Grado consiste en la rearquitectura completa de una aplicación iOS cuyo uso es la gestión de las vacaciones de los empleados de una empresa. Esta aplicación ya existente en la empresa requiere de un cambio completo de la misma: cambio de la arquitectura, interfaces, patrón de acceso a datos y la inclusión de tests automáticos para mejorar la calidad del "producto". También incluye un incremento de la funcionalidad de la aplicación.Grado en Ingeniería Informátic