Distribution of marine litter at bathyal and abyssal depths in the Mediterranean Sea

The distribution, type and quantity of marine litter accumulated on the bathyal and abyssal Mediterranean seafloor has been studied in the framework of the Spanish national projects PROMETEO and DOS MARES and the ESF-EuroDEEP project BIOFUN. Litter was collected with an otter trawl and Agassiz trawl while sampling for megafauna on the Blanes canyon and adjacent slope (Catalan margin, north-western Mediterranean) between 900 and 2700 m depth, and on the western, central and eastern Mediterranean basins at 1200, 2000 and 3000 m depth. All litter was sorted into 8 categories (hard plastic, soft plastic, glass, metal, clinker, fabric, longlines and fishing nets) and weighed. The distribution of litter was analysed in relation to depth, geographic area and natural (bathymetry, currents and rivers) and anthropogenic (population density and shipping routes) processes. The most abundant litter types were plastic, glass, metal and clinker. Lost or discarded fishing gear was also commonly found. On the Catalan margin, although the data indicated an accumulation of litter with increasing depth, mean weight was not significantly different between depths or between the open slope and the canyon. We propose that litter accumulated in the canyon, with high proportions of plastics, has predominantly a coastal origin, while litter collected on the open slope, dominated by heavy litter, is mostly ship-originated, especially at sites under major shipping routes. Along the trans-Mediterranean transect, although a higher amount of litter seemed to be found on the Western Mediterranean, differences of mean weight were not significant between the 3 geographic areas and the 3 depths. Here, the shallower sites, also closer to the coast, had a higher proportion of plastics than the deeper sites, which had a higher proportion of heavy litter and were often affected by shipping routes. The weight of litter was also compared to biomass of megafauna from the same samples. On the Blanes slope, the biomass of megafauna was significantly higher than the weight of litter between 900 and 2000 m depth and no significant differences were found at 2250 and 2700 m depth. Along the trans-Mediterranean transect, no significant differences were found between biomass and litter weight at all sites except in two sites: the Central Mediterranean at 1200 m depth, where biomass was higher than litter weight, and the Eastern Mediterranean at 1200 m depth, where litter weight was higher than biomass. The results are discussed in the framework of knowledge on marine litter accumulation, its potential impact on the habitat and fauna and the legislation addressing these issues.

Bóvedas y contrarresto del Colegio de Nuestra Señora de la Antigua de Monforte de Lemos : geometría, construcción y mecánica

El Colegio de Nuestra Señora de la Antigua de Monforte de Lemos (1593-1619) constituye el principal ejemplo del clasicismo herreriano de Galicia. Esta tesis analiza los aspectos técnicos de la construcción de sus bóvedas de cantería, en el marco disciplinar de la Historia de la Construcción. El Colegio contiene varios tipos de bóvedas entre las que destacan su cúpula trasdosada y su escalera monumental. Además, se conservan los documentos notariales históricos que describen las obras y una de las monteas más importantes de Galicia. Las bóvedas han sufrido movimientos y algunas presentan importantes deformaciones, que han suscitado preocupación sobre su estabilidad. El estudio se organiza en tres epígrafes: geometría, construcción y mecánica, tres aspectos estrechamente interrelacionados en este tipo de estructuras. La parte de estudio geométrico parte de un levantamiento en el que se emplea una estación total sin reflectante, una técnica que permite una medición muy precisa de la forma real de las bóvedas. Como complemento se ha recurrido a técnicas de escáner fotográfico. Con los datos de las mediciones se han elaborado los dibujos de las bóvedas, y analizado sus medidas e irregularidades. Se ha incluido un análisis metrológico por métodos inductivos, que ha puesto de manifiesto la unidad utilizada en la construcción. El estudio se completa con la recopilación de las reglas de dimensionamiento que figuran en los tratados, que se comparan con las dimensiones de las bóvedas analizadas. En el estudio constructivo se registran los despieces y la configuración constructiva y se contrastan, por un lado, con las soluciones que aparecen en los principales tratados de los siglos XVI, XVII y XVIII, y por otro, con las descripciones que se encuentran en los documentos históricos del Colegio. Se ha prestado especial atención al estudio de estos documentos, que han permitido conocer algunos aspectos originales del proceso de construcción de estas bóvedas. En una de las paredes del claustro se ha identificado una montea inédita cuyo levantamiento y análisis se incorpora en esta parte. En el estudio mecánico se analiza la estabilidad dentro del marco teórico del Moderno Análisis Límite de Estructuras de Fábricas. La comprensión del comportamiento estructural, unida a la precisión de los levantamientos, ha permitido explicar los movimientos de las fábricas e inferir la geometría original de algunas de las bóvedas, no siempre evidente en los casos de fuertes deformaciones. Los estudios realizados hasta ahora en bóvedas de los siglos XVI y XVII permiten vislumbrar un panorama de soluciones constructivas más rico que el que recogen los tratados históricos. Las nuevas técnicas de medición sin contacto abren nuevas posibilidades para analizar estas estructuras. Los casos estudiados todavía son escasos y se necesita un conjunto más amplio para poder realizar un análisis general. Esta tesis aporta el estudio de uno de esos casos con el fin de contribuir al mejor conocimiento de la construcción en España en los siglos XVI y XVII. ABSTRACT The Colegio de Nuestra Señora de la Antigua (1593-1619), in Monforte de Lemos, Spain, is the best example in Galicia of the classicism influenced by the Monastery of El Escorial and his architect, Juan de Herrera. This thesis analyzes the technical aspects of the construction of its masonry vaults within the discipline of Construction History. The Colegio exhibits various types of vaults, among which the extradosed ashlar dome and the grand staircase are particularly worth mentioning. In addition, the legal documents containing thorough specifications of the work, as well as one of the construction drawings at actual size —one of the best examples in Galicia—, have both been preserved to this date. Some of the vaults have undergone important deformations that have raised concerns about their stability. The study is organized in three sections: geometry, construction, and mechanics, the three clearly interrelated in this type of structures. The geometrical study starts out with a metric survey using a reflectorless total station, a technique that allows a very precise measurement of the actual shape of the vault. This technique was complemented with the use of a photo-based 3D scanner. The resulting measurements were used to draw the vaults, and analyze their dimensions and irregularities. An inductive metrological analysis, which was able to reveal the exact metric unit utilized during the construction, is included in this section. The section is completed with the gathering of the dimensional rules appearing in the various historical treatises, which are compared with the dimensions of the actual vaults. The construction study deals with the quartering of the structure, whose results are compared, on the one hand, with the approaches appearing in the main treatises of the 16th- 18th centuries, and on the other, with the descriptions in the historical documents of the Colegio itself. Special attention has been paid to the study of these documents, which have revealed some original aspects in the construction process of the vaults. In one of the cloister’s walls, a hitherto unheard-of construction drawing at actual size was found. Its survey and analysis is included in this section. The mechanical study analyzes the Colegio's vaults stability within the theoretical frame of the Modern Limit Analysis of Masonry Structures. The interpretation of the structural behavior, coupled with the precision of the surveys, has allowed a deep understanding of the masonry’s movements and the original geometry of some of the vaults —not always evident in the case of strong deformations— has been inferred. The studies dealing with XVI and XVII century vaults conducted up to this date show a landscape of constructive solutions far richer than the one suggested in the historical treatises. The new contactless measuring techniques offer exciting possibilities for the analysis of these structures. The cases studied are still few and more would be needed before a general analysis can be attempted. This thesis constitutes one such additional case and its goal is to improve our understanding of Spanish construction in the 16th-17th centuries.

Floating car data augmentation based on infrastructure sensors and neural networks

The development of new-generation intelligent vehicle technologies will lead to a better level of road safety and CO2 emission reductions. However, the weak point of all these systems is their need for comprehensive and reliable data. For traffic data acquisition, two sources are currently available: 1) infrastructure sensors and 2) floating vehicles. The former consists of a set of fixed point detectors installed in the roads, and the latter consists of the use of mobile probe vehicles as mobile sensors. However, both systems still have some deficiencies. The infrastructure sensors retrieve information fromstatic points of the road, which are spaced, in some cases, kilometers apart. This means that the picture of the actual traffic situation is not a real one. This deficiency is corrected by floating cars, which retrieve dynamic information on the traffic situation. Unfortunately, the number of floating data vehicles currently available is too small and insufficient to give a complete picture of the road traffic. In this paper, we present a floating car data (FCD) augmentation system that combines information fromfloating data vehicles and infrastructure sensors, and that, by using neural networks, is capable of incrementing the amount of FCD with virtual information. This system has been implemented and tested on actual roads, and the results show little difference between the data supplied by the floating vehicles and the virtual vehicles.

Estudio de estabilidad de barreras de contención hidráulicas mediante tomografia eléctrica y placa de carga en Zaragoza

El objetivo del presente proyecto es definir las actuaciones encaminadas a restaurar el sistema actual de defensa del río Ebro en el tramo Pradilla de Ebro- Boquiñeni (Zaragoza), con el propósito de reducir el riesgo por inundaciones en los núcleos de población del mismo nombre, para lo que se ha realizado una campaña de reconocimiento del Terreno mediante técnicas geofísicas. La campaña de prospección ha consistido en la realización de perfiles de tomografía eléctrica para determinar la distribución de los niveles geoeléctricos en la zona obteniéndose la profundidad y variabilidad del nivel freático y la distribución aparente de los niveles biológicos. En base a las anomalías detectadas en las secciones de resistividad se han llevado a cabo ensayos in situ con placa de carga dinámica con el fin de determinar las características portantes de las barreras. La correlación de ambos estudios permite localizar las zonas de debilidad estructural para así poder establecer las recomendaciones oportunas de cara a restaurar los diques de protección, de forma que puedan cumplir con su función de contención frente a los caudales de crecida. ABSTRACT The aim of this project is so define the interventions required to restore the current defense system of Ebro River in the stretch between Pradilla de Ebro and Boquiñeni (Zaragoza), in order to reduce flood risk in the population centers of the same name, for what a soil survey has been done using geophysical techniques. The geophysical prospecting campaign has consisted on the realization of electrical tomography profiles to determine the distribution of due geoelectric levels in the area, the depth and variability of the water table and the distribution of apparent lithology level. Based on anomalies detected in resistivity sections, dynamic loading plate test were carried out in situ in order to determine the load bearing characteristics of the safety barriers. The correlation o f both studies makes possible to locate die areas o f structural weakness, with the objective of establishing appropriate recommendations to restore the embankments so that they can meet their retaining functions against flood flows.

User benefit assessment by a dynamic LUTI model for Madrid

Assessing users’ benefit in a transport policy implementation has been studied by many researchers using theoretical or empirical measures. However, few of them measure users’ benefit in a different way from the consumer surplus. Therefore, this paper aims to assess a new measure of user benefits by weighting consumer surplus in order to include equity assessment for different transport policies simulated in a dynamic middle-term LUTI model adapted to the case study of Madrid. Three different transport policies, including road pricing, parking charge and public transport improvement have been simulated through the Metropolitan Activity Relocation Simulator, MARS, the LUTI calibrated model for Madrid). A social welfare function (WF) is defined using a cost benefit analysis function that includes mainly costs and benefits of users and operators of the transport system. Particularly, the part of welfare function concerning the users, (i.e. consumer surplus), is modified by a compensating weight (CW) which represents the inverse of household income level. Based on the modified social welfare function, the effects on the measure of users benefits are estimated and compared with the old WF ́s results as well. The result of the analysis shows that road pricing leads a negative effect on the users benefits specially on the low income users. Actually, the road pricing and parking charge implementation results like a regressive policy especially at long term. Public transport improvement scenario brings more positive effects on low income user benefits. The integrated (road pricing and increasing public services) policy scenario is the one which receive the most user benefits. The results of this research could be a key issue to understanding the relationship between transport systems policies and user benefits distribution in a metropolitan context.

Influence of Atmospheric Conditions on mmWave CATR Facilities: Formulation and Compensation Scheme

The performance of a CATR relies on the planarity of the synthesized test wave, which is generated within a bounded volume for which specifications are drawn. Millimetre-wave facilities deal with the classical limitations of this frequency band, among which two become critical in our analysis: time-extensive acquisition campaigns and impact of environmental variables. Both features become more evident when increasing the frequency of operation. The variation in atmospheric variables, such as humidity, temperature and pressure has an influence over the performance of all the elements of the facility. The instrumentation behavior is influenced both by the warming up process, and the ambience conditions that surround the equipment. On the changes of the atmosphere itself, they affect the electromagnetic wave propagation, given the physical link between the conditions of the atmosphere and its electric properties as an electromagnetic waves propagation medium

Algoritmos de agrupación para flujos de datos en entornos centralizados y distribuidos

Los avances en el hardware permiten disponer de grandes volúmenes de datos, surgiendo aplicaciones que deben suministrar información en tiempo cuasi-real, la monitorización de pacientes, ej., el seguimiento sanitario de las conducciones de agua, etc. Las necesidades de estas aplicaciones hacen emerger el modelo de flujo de datos (data streaming) frente al modelo almacenar-para-despuésprocesar (store-then-process). Mientras que en el modelo store-then-process, los datos son almacenados para ser posteriormente consultados; en los sistemas de streaming, los datos son procesados a su llegada al sistema, produciendo respuestas continuas sin llegar a almacenarse. Esta nueva visión impone desafíos para el procesamiento de datos al vuelo: 1) las respuestas deben producirse de manera continua cada vez que nuevos datos llegan al sistema; 2) los datos son accedidos solo una vez y, generalmente, no son almacenados en su totalidad; y 3) el tiempo de procesamiento por dato para producir una respuesta debe ser bajo. Aunque existen dos modelos para el cómputo de respuestas continuas, el modelo evolutivo y el de ventana deslizante; éste segundo se ajusta mejor en ciertas aplicaciones al considerar únicamente los datos recibidos más recientemente, en lugar de todo el histórico de datos. En los últimos años, la minería de datos en streaming se ha centrado en el modelo evolutivo. Mientras que, en el modelo de ventana deslizante, el trabajo presentado es más reducido ya que estos algoritmos no sólo deben de ser incrementales si no que deben borrar la información que caduca por el deslizamiento de la ventana manteniendo los anteriores tres desafíos. Una de las tareas fundamentales en minería de datos es la búsqueda de agrupaciones donde, dado un conjunto de datos, el objetivo es encontrar grupos representativos, de manera que se tenga una descripción sintética del conjunto. Estas agrupaciones son fundamentales en aplicaciones como la detección de intrusos en la red o la segmentación de clientes en el marketing y la publicidad. Debido a las cantidades masivas de datos que deben procesarse en este tipo de aplicaciones (millones de eventos por segundo), las soluciones centralizadas puede ser incapaz de hacer frente a las restricciones de tiempo de procesamiento, por lo que deben recurrir a descartar datos durante los picos de carga. Para evitar esta perdida de datos, se impone el procesamiento distribuido de streams, en concreto, los algoritmos de agrupamiento deben ser adaptados para este tipo de entornos, en los que los datos están distribuidos. En streaming, la investigación no solo se centra en el diseño para tareas generales, como la agrupación, sino también en la búsqueda de nuevos enfoques que se adapten mejor a escenarios particulares. Como ejemplo, un mecanismo de agrupación ad-hoc resulta ser más adecuado para la defensa contra la denegación de servicio distribuida (Distributed Denial of Services, DDoS) que el problema tradicional de k-medias. En esta tesis se pretende contribuir en el problema agrupamiento en streaming tanto en entornos centralizados y distribuidos. Hemos diseñado un algoritmo centralizado de clustering mostrando las capacidades para descubrir agrupaciones de alta calidad en bajo tiempo frente a otras soluciones del estado del arte, en una amplia evaluación. Además, se ha trabajado sobre una estructura que reduce notablemente el espacio de memoria necesario, controlando, en todo momento, el error de los cómputos. Nuestro trabajo también proporciona dos protocolos de distribución del cómputo de agrupaciones. Se han analizado dos características fundamentales: el impacto sobre la calidad del clustering al realizar el cómputo distribuido y las condiciones necesarias para la reducción del tiempo de procesamiento frente a la solución centralizada. Finalmente, hemos desarrollado un entorno para la detección de ataques DDoS basado en agrupaciones. En este último caso, se ha caracterizado el tipo de ataques detectados y se ha desarrollado una evaluación sobre la eficiencia y eficacia de la mitigación del impacto del ataque. ABSTRACT Advances in hardware allow to collect huge volumes of data emerging applications that must provide information in near-real time, e.g., patient monitoring, health monitoring of water pipes, etc. The data streaming model emerges to comply with these applications overcoming the traditional store-then-process model. With the store-then-process model, data is stored before being consulted; while, in streaming, data are processed on the fly producing continuous responses. The challenges of streaming for processing data on the fly are the following: 1) responses must be produced continuously whenever new data arrives in the system; 2) data is accessed only once and is generally not maintained in its entirety, and 3) data processing time to produce a response should be low. Two models exist to compute continuous responses: the evolving model and the sliding window model; the latter fits best with applications must be computed over the most recently data rather than all the previous data. In recent years, research in the context of data stream mining has focused mainly on the evolving model. In the sliding window model, the work presented is smaller since these algorithms must be incremental and they must delete the information which expires when the window slides. Clustering is one of the fundamental techniques of data mining and is used to analyze data sets in order to find representative groups that provide a concise description of the data being processed. Clustering is critical in applications such as network intrusion detection or customer segmentation in marketing and advertising. Due to the huge amount of data that must be processed by such applications (up to millions of events per second), centralized solutions are usually unable to cope with timing restrictions and recur to shedding techniques where data is discarded during load peaks. To avoid discarding of data, processing of streams (such as clustering) must be distributed and adapted to environments where information is distributed. In streaming, research does not only focus on designing for general tasks, such as clustering, but also in finding new approaches that fit bests with particular scenarios. As an example, an ad-hoc grouping mechanism turns out to be more adequate than k-means for defense against Distributed Denial of Service (DDoS). This thesis contributes to the data stream mining clustering technique both for centralized and distributed environments. We present a centralized clustering algorithm showing capabilities to discover clusters of high quality in low time and we provide a comparison with existing state of the art solutions. We have worked on a data structure that significantly reduces memory requirements while controlling the error of the clusters statistics. We also provide two distributed clustering protocols. We focus on the analysis of two key features: the impact on the clustering quality when computation is distributed and the requirements for reducing the processing time compared to the centralized solution. Finally, with respect to ad-hoc grouping techniques, we have developed a DDoS detection framework based on clustering.We have characterized the attacks detected and we have evaluated the efficiency and effectiveness of mitigating the attack impact.