DESIGN OF EFFICIENT IN-NETWORK DATA PROCESSING AND DISSEMINATION FOR VANETS

By providing vehicle-to-vehicle and vehicle-to-infrastructure wireless communications, vehicular ad hoc networks (VANETs), also known as the “networks on wheels”, can greatly enhance traffic safety, traffic efficiency and driving experience for intelligent transportation system (ITS). However, the unique features of VANETs, such as high mobility and uneven distribution of vehicular nodes, impose critical challenges of high efficiency and reliability for the implementation of VANETs. This dissertation is motivated by the great application potentials of VANETs in the design of efficient in-network data processing and dissemination. Considering the significance of message aggregation, data dissemination and data collection, this dissertation research targets at enhancing the traffic safety and traffic efficiency, as well as developing novel commercial applications, based on VANETs, following four aspects: 1) accurate and efficient message aggregation to detect on-road safety relevant events, 2) reliable data dissemination to reliably notify remote vehicles, 3) efficient and reliable spatial data collection from vehicular sensors, and 4) novel promising applications to exploit the commercial potentials of VANETs. Specifically, to enable cooperative detection of safety relevant events on the roads, the structure-less message aggregation (SLMA) scheme is proposed to improve communication efficiency and message accuracy. The scheme of relative position based message dissemination (RPB-MD) is proposed to reliably and efficiently disseminate messages to all intended vehicles in the zone-of-relevance in varying traffic density. Due to numerous vehicular sensor data available based on VANETs, the scheme of compressive sampling based data collection (CS-DC) is proposed to efficiently collect the spatial relevance data in a large scale, especially in the dense traffic. In addition, with novel and efficient solutions proposed for the application specific issues of data dissemination and data collection, several appealing value-added applications for VANETs are developed to exploit the commercial potentials of VANETs, namely general purpose automatic survey (GPAS), VANET-based ambient ad dissemination (VAAD) and VANET based vehicle performance monitoring and analysis (VehicleView). Thus, by improving the efficiency and reliability in in-network data processing and dissemination, including message aggregation, data dissemination and data collection, together with the development of novel promising applications, this dissertation will help push VANETs further to the stage of massive deployment.

Space density distribution of galaxies in the absolute magnitude - rotation velocity plane: a volume-complete Tully-Fisher relation from CALIFA stellar kinematics

We measured the distribution in absolute magnitude - circular velocity space for a well-defined sample of 199 rotating galaxies of the Calar Alto Legacy Integral Field Area Survey (CALIFA) using their stellar kinematics. Our aim in this analysis is to avoid subjective selection criteria and to take volume and large-scale structure factors into account. Using stellar velocity fields instead of gas emission line kinematics allows including rapidly rotating early-type galaxies. Our initial sample contains 277 galaxies with available stellar velocity fields and growth curve r-band photometry. After rejecting 51 velocity fields that could not be modelled because of the low number of bins, foreground contamination, or significant interaction, we performed Markov chain Monte Carlo modelling of the velocity fields, from which we obtained the rotation curve and kinematic parameters and their realistic uncertainties. We performed an extinction correction and calculated the circular velocity v_circ accounting for the pressure support of a given galaxy. The resulting galaxy distribution on the M-r - v(circ) plane was then modelled as a mixture of two distinct populations, allowing robust and reproducible rejection of outliers, a significant fraction of which are slow rotators. The selection effects are understood well enough that we were able to correct for the incompleteness of the sample. The 199 galaxies were weighted by volume and large-scale structure factors, which enabled us to fit a volume-corrected Tully-Fisher relation (TFR). More importantly, we also provide the volume-corrected distribution of galaxies in the M_r - v_circ plane, which can be compared with cosmological simulations. The joint distribution of the luminosity and circular velocity space densities, representative over the range of -20 > M_r > -22 mag, can place more stringent constraints on the galaxy formation and evolution scenarios than linear TFR fit parameters or the luminosity function alone.

The EU landing obligation and European small-scale fisheries: What are the odds for success?

A landing obligation was formally implemented in the European Union (EU) for the first time, as part of the recent reform of the EU Common Fisheries Policy (CFP). Given the reasonable success of the landing obligation in some countries such as the Faroe Islands, Iceland and Norway, this policy is seen as a viable approach to tackle the long-recognized discarding problem in EU waters. However, there has been some debate on whether there is sufficient evidence to support the feasibility of such a measure in the EU-CFP. The EU landing obligation will implicitly include all small-scale fisheries (SSF) provided the species captured are subject to catch limits or minimum sizes (in the case of the Mediterranean). SSF were included irrespective of the fact that the discarding problem in the EU has been historically associated with medium- to large-scale fleets (in particular largely mixed species trawl fisheries). Additionally, past experiences with a discard ban policy are still limited to specific countries and/or specific fisheries. This paper examined the appropriateness and feasibility of the recently implemented EU landing obligation in SSF. The effects in the long-term are unpredictable, but available evidence suggests that in the short to medium-term a landing obligation is likely to bring more negative social, economic and ecological impacts than benefits. (C) 2015 Elsevier Ltd. All rights reserved.

Acoso laboral y sus efectos en la salud del trabajador : revisión de la literatura

Introducción: Desde los años 80 se viene haciendo énfasis en el acoso laboral, conocido en otros países como Mobbing, describiéndose como una forma de abuso y violencia psicológica en el lugar de trabajo, realizado ya sea por una sola persona o por un grupo de personas y que por sus implicaciones se estima de alto impacto para los trabajadores, y las organizaciones. Considerando la importancia y prevalencia del mobbing en la sociedad actual, se convierte en un tema relevante para el área de salud ocupacional. Objetivo: El objetivo de este estudio fue identificar los efectos del acoso laboral generados en la salud del trabajador. Metodología: Se realizó una revisión sistemática utilizando el método PRISMA, de las publicaciones vigentes entre los años 2006 a 2016 sobre los efectos del acoso laboral en la salud del trabajador. En la búsqueda se obtuvieron 778 artículos de los cuales 27 cumplían con los criterios de inclusión. Resultados: se encontró que la prevalencia del acoso laboral puede ser diferente de acuerdo a la definición utilizada, instrumento de medida y población estudiada, la cual fluctúa entre el 7% al 88% según el estudio analizado. Además se evidenció que la prevalencia también difiere dependiendo de quién sea el perpetrador del acoso, si el líder o jefe es el acosador es mayor (60,3%) que cuando es causado por colegas o por clientes (41,5%). El impacto del acoso laboral, según la mayoría de los estudios, es que provoca efectos negativos en la salud emocional del trabajador siendo la depresión una de las principales consecuencias con una relación estadísticamente significativa (p<0,001). Las enfermedades del aparato respiratorio y del sistema musculo esquelético y del tejido conectivo fueron las que se presentaron con mayor frecuencia en los trabajadores que sufren de acoso con un 43,5% y un 37.8% respectivamente. Conclusiones: éstos resultados demuestran que el acoso laboral no solamente es un problema desde el punto de vista organizacional, sino que conlleva consecuencias en la salud mental y física de los trabajadores que lo sufren. Palabras clave: Mobbing, workplace, acoso laboral, acoso psicológico, bullying, harassment, salud ocupacional, occupational health.

la influencia de la felicidad en las decisiones de inversión de activos de largo plazo para una muestra de siete gerentes financieros en la ciudad de Bogotá en el año 2016.

El presente artículo contribuye con la investigación de las Finanzas Corporativas del Comportamiento, rama de las finanzas corporativas que considera que el individuo que toma decisiones financieras no es completamente racional y que por hecho existen sesgos psicológicos que influyen en sus decisiones. Este documento se enfoca, desde el punto de vista conceptual y también mediante el análisis de un estudio de campo, en la influencia de la felicidad en las decisiones de inversión en activos de largo plazo para un grupo de siete gerentes ubicados en la ciudad de Bogotá en el año 2016. En el documento se abarca el concepto general de las finanzas corporativas del comportamiento, se define la felicidad y se presentan sub-variables determinantes para la felicidad del individuo como lo son: salud, balance vida/trabajo, educación y habilidades, conexiones sociales y medio ambiente. Finalmente se presenta cómo éstas afectan a los gerentes financieros en sus decisiones de acuerdo a la investigación realizada.

Spatial, environmental and human influences on the distribution of otter (Lutra lutra) in the Spanish provinces

In a previous survey of otters ( Lutra lutra L. 1758) in Spain, different causes were invoked to explain the frequency of the species in each province. To find common causes of the distribution of the otter in Spain, we recorded a number of spatial, environmental and human variables in each Spanish province. We then performed a stepwise linear multiple regression of the proportion of positive sites of otter in the Spanish provinces separately on each of the three groups of variables. Geographic longitude, January air humidity, soil permeability and highway density were the variables selected. A linear regression of the proportion of otter presence on these variables explained 62.4% of the variance. We then used the selected variables in a partial regression analysis to specify which proportions of the variation are explained exclusively by spatial, environmental and human factors, and which proportions are attributable to interactions between these components. Pure environmental effects accounted for only 5.5% of the variation, while pure spatial and pure human effects explained 18% and 9.7%, respectively. Shared variation among the components totalled 29.2%, of which 10.9% was explained by the interaction between environmental and spatial factors. Human factors explained globally less variance than spatial and environmental ones, but the pure human influence was higher than the pure environmental one. We concluded that most of the variation in the proportion of occurrences of otter in Spanish provinces is spatially structured, and that environmental factors have more influence on otter presence than human ones; however, the human influence on otter distribution is less structured in space, and thus can be more disruptive. This effect of large infrastructures on wild populations must be taken into account when planning large-scale conservation policies