Floating-point exponentiation units for reconfigurable computing

The high performance and capacity of current FPGAs makes them suitable as acceleration co-processors. This article studies the implementation, for such accelerators, of the floating-point power function xy as defined by the C99 and IEEE 754-2008 standards, generalized here to arbitrary exponent and mantissa sizes. Last-bit accuracy at the smallest possible cost is obtained thanks to a careful study of the various subcomponents: a floating-point logarithm, a modified floating-point exponential, and a truncated floating-point multiplier. A parameterized architecture generator in the open-source FloPoCo project is presented in details and evaluated.

Finite element simulation of sandwich panels of plasterboard and rock wool under mixed mode fracture

This paper presents the results of research on mixed mode fracture of sandwich panels of plasterboard and rock wool. The experimental data of the performed tests are supplied. The specimens were made from commercial panels. Asymmetrical three-point bending tests were performed on notched specimens. Three sizes of geometrically similar specimens were tested for studying the size effect. The paper also includes the numerical simulation of the experimental results by using an embedded cohesive crack model.The involved parameters for modelling are previously measured by standardised tests.

Blends of babassu, palm kernal and coconut mame with fossil kerosene: low carbon number methyl esters as a possible source for renewable jet fuel

Three different oils: babassu, coconut and palm kernel have been transesterified with methanol. The fatty acid methyl esters (FAME) have been subjected to vacuum fractional distillation, and the low boiling point fractions have been blended with fossil kerosene at three different proportions: 5, 10 and 20% vol.

Generalized synchronization in relay systems with instantaneous coupling

We demonstrate the existence of generalized synchronization in systems that act as mediators between two dynamical units that, in turn, show complete synchronization with each other. These are the so-called relay systems. Specifically, we analyze the Lyapunov spectrum of the full system to elucidate when complete and generalized synchronization appear. We show that once a critical coupling strength is achieved, complete synchronization emerges between the systems to be synchronized, and at the same point, generalized synchronization with the relay system also arises. Next, we use two nonlinear measures based on the distance between phase-space neighbors to quantify the generalized synchronization in discretized time series. Finally, we experimentally show the robustness of the phenomenon and of the theoretical tools here proposed to characterize it.

Evaluaci��n de un forward modelling de ondas s��smicas : aplicaci��n pr��ctica del efecto source ghost

Se ha utilizado un programa de modelizaci��n de ondas s��smicas por m��todos finitos en dos dimensiones para analizar el efecto Source Ghost en profundidades de 4, 14, 24 y 34 metros. Este efecto se produce cuando se dispara una fuente enterrada y, debido al contacto suelo-aire, se genera una onda reflejada que, en cierto momento, se superpone con la onda principal, produci��ndose una disminuci��n de la amplitud de la onda (Source Ghost). Los resultados te��ricos del efecto se han comparado con los resultados pr��cticos del programa de modelizaci��n concluy��ndose que es posible determinar el rango de frecuencias afectado por el efecto. Sin embargo, la distancia entre receptor y fuente es una nueva variable que desplaza el efecto hacia frecuencias m��s altas impidiendo su predicci��n. La utilizaci��n de una t��cnica de procesamiento b��sica como la correcci��n del Normal Move-Out (NMO) en el apilado de las trazas, contrarresta la variable distancia receptor-fuente, y por tanto es posible calcular el rango de frecuencias del efecto Source Ghost. Abstract A seismic wave forward modeling in two dimensions using finite-difference method has been used for analyzing the Source Ghost effect at depths between 4-34 meters. A shot from a buried source generates a down going reflection due to the free surface boundary and, at some point, it interferes with the main wave propagation causing a reduction of wave amplitude at some frequency range (Source Ghost). Theoretical results and experimental results provided by the forward modeling are compared for concluding that the forward modeling is able to identify the frequency range affected by the source ghost. Nevertheless, it has been found that the receiver-source distance (offset) is a new variable that modifies the frequency range to make it unpredictable. A basic seismic processing technique, Normal Move-Out (NMO) correction, has been used for a single twenty fold CMP gather. The final stack shows that the processing technique neutralize the offset effect and therefore the forward modeling is still capable to determine the affected frequency range by the source ghost regardless the distance between receiver and source.

Gesti��n de la informaci��n en redes de sensores inal��mbricos

La gesti��n del conocimiento (KM) es el proceso de recolectar datos en bruto para su an��lisis y filtrado, con la finalidad de obtener conocimiento ��til a partir de dichos datos. En este proyecto se pretende hacer un estudio sobre la gesti��n de la informaci��n en las redes de sensores inal��mbricos como inicio para sentar las bases para la gesti��n del conocimiento en las mismas. Las redes de sensores inal��mbricos (WSN) son redes compuestas por sensores (tambi��n conocidos como motas) distribuidos sobre un ��rea, cuya misi��n es monitorizar una o varias condiciones f��sicas del entorno. Las redes de sensores inal��mbricos se caracterizan por tener restricciones de consumo para los sensores que utilizan bater��as, por su capacidad para adaptarse a cambios y ser escalables, y tambi��n por su habilidad para hacer frente a fallos en los sensores. En este proyecto se hace un estudio sobre la gesti��n de la informaci��n en redes de sensores inal��mbricos. Se comienza introduciendo algunos conceptos b��sicos: arquitectura, pila de protocolos, topolog��as de red, etc.��� Despu��s de esto, se ha enfocado el estudio hacia TinyDB, el cual puede ser considerado como parte de las tecnolog��as m��s avanzadas en el estado del arte de la gesti��n de la informaci��n en redes de sensores inal��mbricos. TinyDB es un sistema de procesamiento de consultas para extraer informaci��n de una red de sensores. Proporciona una interfaz similar a SQL y permite trabajar con consultas contra la red de sensores inal��mbricos como si se tratara de una base de datos tradicional. Adem��s, TinyDB implementa varias optimizaciones para manejar los datos eficientemente. En este proyecto se describe tambi��n la implementaci��n de una sencilla aplicaci��n basada en redes de sensores inal��mbricos. Las motas en la aplicaci��n son capaces de medir la corriente a trav��s de un cable. El objetivo de esta aplicaci��n es monitorizar el consumo de energ��a en diferentes zonas de un ��rea industrial o dom��stico, utilizando redes de sensores inal��mbricas. Adem��s, se han implementado las optimizaciones m��s importantes que se han aprendido en el an��lisis de la plataforma TinyDB. Para desarrollar esta aplicaci��n se ha utilizado como sensores la plataforma open-source de creaci��n de prototipos electr��nicos Arduino, y el ordenador de placa reducida Raspberry Pi como coordinador. ABSTRACT. Knowledge management (KM) is the process of collecting raw data for analysis and filtering, to get a useful knowledge from this data. In this project the information management in wireless sensor networks is studied as starting point before knowledge management. Wireless sensor networks (WSN) are networks which consists of sensors (also known as motes) distributed over an area, to monitor some physical conditions of the environment. Wireless sensor networks are characterized by power consumption constrains for sensors which are using batteries, by the ability to be adaptable to changes and to be scalable, and by the ability to cope sensor failures. In this project it is studied information management in wireless sensor networks. The document starts introducing basic concepts: architecture, stack of protocols, network topology��� After this, the study has been focused on TinyDB, which can be considered as part of the most advanced technologies in the state of the art of information management in wireless sensor networks. TinyDB is a query processing system for extracting information from a network of sensors. It provides a SQL-like interface and it lets us to work with queries against the wireless sensor network like if it was a traditional database. In addition, TinyDB implements a lot of optimizations to manage data efficiently. In this project, it is implemented a simple wireless sensor network application too. Application���s motes are able to measure amperage through a cable. The target of the application is, by using a wireless sensor network and these sensors, to monitor energy consumption in different areas of a house. Additionally, it is implemented the most important optimizations that we have learned from the analysis of TinyDB platform. To develop this application it is used Arduino open-source electronics prototyping platform as motes, and Raspberry Pi single-board computer as coordinator.

Micromechanical basis for shear strength of rock discontinuities

The theoretical basis for evaluating shear strength in rock joints is presented and used to derive an equation that governs the relationship between tangential and normal stress on the joint during situations of slippage between the joint faces. The dependent variables include geometric dilatancy, the instantaneous friction angle, and a parameter that considers joint surface roughness. The effect roughness is studied, and the aforementioned formula is used to analyse joints under different conditions. A mathematical expression is deduced that explains Barton's value for the joint roughness coefficient (JRC) according to the roughness geometry. In particular, when the Hoek and Brown failure criterion is used for a rock in the contact with the surface roughness plane, it is possible to determine the shear strength of the joint as a function of the relationship between the uniaxial compressive strength of the wall with the normal stress acting on the wall. Finally, theoretical results obtained for the geometry of a three-dimensional joint are compared with those of the Barton's formulation

A proposal for an Internet of Things-based monitoring system composed by low capability, open source and open hardware devices

The Internet of Things makes use of a huge disparity of technologies at very different levels that help one to the other to accomplish goals that were previously regarded as unthinkable in terms of ubiquity or scalability. If the Internet of Things is expected to interconnect every day devices or appliances and enable communications between them, a broad range of new services, applications and products can be foreseen. For example, monitoring is a process where sensors have widespread use for measuring environmental parameters (temperature, light, chemical agents, etc.) but obtaining readings at the exact physical point they want to be obtained from, or about the exact wanted parameter can be a clumsy, time-consuming task that is not easily adaptable to new requirements. In order to tackle this challenge, a proposal on a system used to monitor any conceivable environment, which additionally is able to monitor the status of its own components and heal some of the most usual issues of a Wireless Sensor Network, is presented here in detail, covering all the layers that give it shape in terms of devices, communications or services.

Agricultural use of organic wastes as source of nitrogen and phosphorus: risks and opportunities

El nitr��geno (N) y el f��sforo (P) son nutrientes esenciales en la producci��n de cultivos. El desarrollo de los fertilizantes de s��ntesis durante el siglo XX permiti�� una intensificaci��n de la agricultura y un aumento de las producciones pero a su vez el gran input de nutrientes ha resultado en algunos casos en sistemas poco eficientes incrementando las p��rdidas de estos nutrientes al medio ambiente. En el caso del P, este problema se agrava debido a la escasez de reservas de roca fosf��rica necesaria para la fabricaci��n de fertilizantes fosfatados. La utilizaci��n de residuos org��nicos en agricultura como fuente de N y P es una buena opci��n de manejo que permite valorizar la gran cantidad de residuos que se generan. Sin embargo, es importante conocer los procesos que se producen en el suelo tras la aplicaci��n de los mismos, ya que influyen en la disponibilidad de nutrientes que pueden ser utilizados por el cultivo as�� como en las p��rdidas de nutrientes de los agrosistemas que pueden ocasionar problemas de contaminaci��n. Aunque la din��mica del N en el suelo ha sido m��s estudiada que la del P, los problemas importantes de contaminaci��n por nitratos en zonas vulnerables hacen necesaria la evaluaci��n de aquellas pr��cticas de manejo que pudieran agravar esta situaci��n, y en el caso de los residuos org��nicos, la evaluaci��n de la respuesta agron��mica y medioambiental de la aplicaci��n de materiales con un alto contenido en N (como los residuos procedentes de la industria vin��cola y alcoholera). En cuanto al P, debido a la mayor complejidad de su ciclo y de las reacciones que ocurren en el suelo, hay un mayor desconocimiento de los factores que influyen en su din��mica en los sistemas suelo-planta, lo que supone nuevas oportunidades de estudio en la evaluaci��n del uso agr��cola de los residuos org��nicos. Teniendo en cuenta los conocimientos previos sobre cada nutriente as�� como las necesidades espec��ficas en el estudio de los mismos, en esta Tesis se han evaluado: (1) el efecto de la aplicaci��n de residuos procedentes de la industria vin��cola y alcoholera en la din��mica del N desde el punto de vista agron��mico y medioambiental en una zona vulnerable a la contaminaci��n por nitratos; y (2) los factores que influyen en la disponibilidad de P en el suelo tras la aplicaci��n de residuos org��nicos. Para ello se han llevado a cabo incubaciones de laboratorio as�� como ensayos de campo que permitieran evaluar la din��mica de estos nutrientes en condiciones reales. Las incubaciones de suelo en condiciones controladas de humedad y temperatura para determinar el N mineralizado se utilizan habitualmente para estimar la disponibilidad de N para el cultivo as�� como el riesgo medioambiental. Por ello se llev�� a cabo una incubaci��n en laboratorio para conocer la velocidad de mineralizaci��n de N de un compost obtenido a partir de residuos de la industria vin��cola y alcoholera, ampliamente distribuida en Castilla-La Mancha, regi��n con problemas importantes de contaminaci��n de acu��feros por nitratos. Se probaron tres dosis crecientes de compost correspondientes a 230, 460 y 690 kg de N total por hect��rea que se mezclaron con un suelo franco arcillo arenoso de la zona. La evoluci��n del N mineral en el suelo a lo largo del tiempo se ajust�� a un modelo de regresi��n no lineal, obteniendo valores bajos de N potencialmente mineralizable y bajas contantes de mineralizaci��n, lo que indica que se trata de un material resistente a la mineralizaci��n y con una lenta liberaci��n de N en el suelo, mineraliz��ndose tan solo 1.61, 1.33 y 1.21% del N total aplicado con cada dosis creciente de compost (para un periodo de seis meses). Por otra parte, la mineralizaci��n de N tras la aplicaci��n de este material tambi��n se evalu�� en condiciones de campo, mediante la elaboraci��n de un balance de N durante dos ciclos de cultivo (2011 y 2012) de mel��n bajo riego por goteo, cultivo y manejo agr��cola muy caracter��sticos de la zona de estudio. Las constantes de mineralizaci��n obtenidas en el laboratorio se ajustaron a las temperaturas reales en campo para predecir el N mineralizado en campo durante el ciclo de cultivo del mel��n, sin embargo este modelo generalmente sobreestimaba el N mineralizado observado en campo, por la influencia de otros factores no tenidos en cuenta para obtener esta predicci��n, como el N acumulado en el suelo, el efecto de la planta o las fluctuaciones de temperatura y humedad. Tanto el ajuste de los datos del laboratorio al modelo de mineralizaci��n como las predicciones del mismo fueron mejores cuando se consideraba el efecto de la mezcla suelo-compost que cuando se aislaba el N mineralizado del compost, mostrando la importancia del efecto del suelo en la mineralizaci��n del N procedente de residuos org��nicos. Dado que esta zona de estudio ha sido declarada vulnerable a la contaminaci��n por nitratos y cuenta con diferentes unidades hidrol��gicas protegidas, en el mismo ensayo de campo con mel��n bajo riego por goteo se evalu�� el riesgo de contaminaci��n por nitratos tras la aplicaci��n de diferentes dosis de compost bajo dos reg��menes de riego, riego ajustado a las necesidades del cultivo (90 �� 100% de la evapotranspiraci��n del cultivo (ETc)) o riego excedentario (120% ETc). A lo largo del ciclo de cultivo se estim�� semanalmente el drenaje mediante la realizaci��n de un balance h��drico, as�� como se tomaron muestras de la soluci��n de suelo y se determin�� su concentraci��n de nitratos. Para evaluar el riesgo de contaminaci��n de las aguas subterr��neas asociado con estas pr��cticas, se utilizaron algunos ��ndices medioambientales para determinar la variaci��n en la calidad del agua potable (��ndice de Impacto (II)) y en la concentraci��n de nitratos del acu��fero (��ndice de Impacto Ambiental (EII)). Para combinar par��metros medioambientales con par��metros de producci��n, se calcul�� la eficiencia de manejo. Se observ�� que la aplicaci��n de compost bajo un r��gimen de riego ajustado no aumentaba el riesgo de contaminaci��n de las aguas subterr��neas incluso con la aplicaci��n de la dosis m��s alta. Sin embargo, la aplicaci��n de grandes cantidades de compost combinada con un riego excedentario supuso un incremento en el N lixiviado a lo largo del ciclo de cultivo, mientras que no se obtuvieron mayores producciones con respecto al riego ajustado. La aplicaci��n de residuos de la industria vin��cola y alcoholera como fuente de P fue evaluada en suelos calizos caracterizados por una alta capacidad de retenci��n de P, lo cual en algunos casos limita la disponibilidad de este nutriente. Para ello se llev�� a cabo otro ensayo de incubaci��n con dos suelos de diferente textura, con diferente contenido de carbonato c��lcico, hierro y con dos niveles de P disponible; a los que se aplicaron diferentes materiales procedentes de estas industrias (con y sin compostaje previo) aportando diferentes cantidades de P. A lo largo del tiempo se analiz�� el P disponible del suelo (P Olsen) as�� como el pH y el carbono org��nico disuelto. Al final de la incubaci��n, con el fin de estudiar los cambios producidos por los diferentes residuos en el estado del P del suelo se llev�� a cabo un fraccionamiento del P inorg��nico del suelo, el cual se separ�� en P soluble y d��bilmente enlazado (NaOH-NaCl-P), P soluble en reductores u ocluido en los ��xidos de Fe (CBD-P) y P poco soluble precipitado como Ca-P (HCl-P); y se determin�� la capacidad de retenci��n de P as�� como el grado de saturaci��n de este elemento en el suelo. En este ensayo se observ�� que, dada la naturaleza caliza de los suelos, la influencia de la cantidad de P aplicado con los residuos en el P disponible s��lo se produc��a al comienzo del periodo de incubaci��n, mientras que al final del ensayo el incremento en el P disponible del suelo se igualaba independientemente del P aplicado con cada residuo, aumentando el P retenido en la fracci��n menos soluble con el aumento del P aplicado. Por el contrario, la aplicaci��n de materiales org��nicos menos estabilizados y con un menor contenido en P, produjo un aumento en las formas de P m��s l��biles debido a una disoluci��n del P retenido en la fracci��n menos l��bil, lo cual demostr�� la influencia de la materia org��nica en los procesos que controlan el P disponible en el suelo. La aplicaci��n de residuos aument�� el grado de saturaci��n de P de los suelos, sin embargo los valores obtenidos no superaron los l��mites establecidos que indican un riesgo de contaminaci��n de las aguas. La influencia de la aplicaci��n de residuos org��nicos en las formas de P inorg��nico y org��nico del suelo se estudi�� adem��s en un suelo ��cido de textura areno francosa tras la aplicaci��n en campo a largo plazo de esti��rcol vacuno y de compost obtenido a partir de biorresiduos, as�� como la aplicaci��n combinada de compost y un fertilizante mineral (superfosfato tripe), en una rotaci��n de cultivos. En muestras de suelo recogidas 14 a��os despu��s del establecimiento del experimento en campo, se determin�� el P soluble y disponible, la capacidad de adsorci��n de P, el grado de saturaci��n de P as�� como diferentes actividades enzim��ticas (actividad deshidrogenasa, fosfatasa ��cida y fosfatasa alcalina). Las diferentes formas de P org��nico en el suelo se estudiaron mediante una t��cnica de adici��n de enzimas con diferentes substratos espec��ficos a extractos de suelo de NaOH-EDTA, midiendo el P hidrolizado durante un periodo de incubaci��n por colorimetr��a. Las enzimas utilizadas fueron la fosfatasa ��cida, la nucleasa y la fitasa las cuales permitieron identificar mono��steres hidrolizables (monoester-like P), di��steres (DNA-like P) e inositol hexaquifosfato (Ins6P-like P). La aplicaci��n a largo plazo de residuos org��nicos aument�� el P disponible del suelo proporcionalmente al P aplicado con cada tipo de fertilizaci��n, suponiendo un mayor riesgo de p��rdidas de P dado el alto grado de saturaci��n de este suelo. La aplicaci��n de residuos org��nicos aument�� el P org��nico del suelo resistente a la hidr��lisis enzim��tica, sin embargo no influy�� en las diferentes formas de P hidrolizable por las enzimas en comparaci��n con las observadas en el suelo sin enmendar. Adem��s, las diferentes formas de P org��nico aplicadas con los residuos org��nicos no se correspondieron con las analizadas en el suelo lo cual demostr�� que ��stas son el resultado de diferentes procesos en el suelo mediados por las plantas, los microorganismos u otros procesos abi��ticos. En este estudio se encontr�� una correlaci��n entre el Ins6P-like P y la actividad microbiana (actividad deshidrogenasa) del suelo, lo cual refuerza esta afirmaci��n. Por ��ltimo, la aplicaci��n de residuos org��nicos como fuente de N y P en la agricultura se evalu�� agron��micamente en un escenario real. Se estableci�� un experimento de campo para evaluar el compost procedente de residuos de bodegas y alcoholeras en el mismo cultivo de mel��n utilizado en el estudio de la mineralizaci��n y lixiviaci��n de N. En este experimento se estudi�� la aplicaci��n de tres dosis de compost: 1, 2 y 3 kg de compost por metro lineal de plantaci��n correspondientes a 7, 13 y 20 t de compost por hect��rea respectivamente; y se estudi�� el efecto sobre el crecimiento de las plantas, la acumulaci��n de N y P en la planta, as�� como la producci��n y calidad del cultivo. La aplicaci��n del compost produjo un ligero incremento en la biomasa vegetal acompa��ado por una mejora significativa de la producci��n con respecto a las parcelas no enmendadas, obteni��ndose la m��xima producci��n con la aplicaci��n de 2 kg de compost por metro lineal. Aunque los efectos potenciales del N y P fueron parcialmente enmascarados por otras entradas de estos nutrientes en el sistema (alta concentraci��n de nitratos en el agua de riego y ��cido fosf��rico suministrado por fertirrigaci��n), se observ�� una mayor acumulaci��n de P uno de los a��os de estudio que result�� en un aumento en el n��mero de frutos en las parcelas enmendadas. Adem��s, la mayor acumulaci��n de N y P disponible en el suelo al final del ciclo de cultivo indic�� el potencial uso de estos materiales como fuente de estos nutrientes. ABSTRACT Nitrogen (N) and phosphorus (P) are essential nutrients in crop production. The development of synthetic fertilizers during the 20th century allowed an intensification of the agriculture increasing crop yields but in turn the great input of nutrients has resulted in some cases in inefficient systems with higher losses to the environment. Regarding P, the scarcity of phosphate rock reserves necessary for the production of phosphate fertilizers aggravates this problem. The use of organic wastes in agriculture as a source of N and P is a good option of management that allows to value the large amount of wastes generated. However, it is important to understand the processes occurring in the soil after application of these materials, as they affect the availability of nutrients that can be used by the crop and the nutrient losses from agricultural systems that can cause problems of contamination. Although soil N dynamic has been more studied than P, the important concern of nitrate pollution in Nitrate Vulnerable Zones requires the evaluation of those management practices that could aggravate this situation, and in the case of organic wastes, the evaluation of the agronomic and environmental response after application of materials with a high N content (such as wastes from winery and distillery industries). On the other hand, due to the complexity of soil P cycle and the reactions that occur in soil, there is less knowledge about the factors that can influence its dynamics in the soil-plant system, which means new opportunities of study regarding the evaluation of the agricultural use of organic wastes. Taking into account the previous knowledge of each nutrient and the specific needs of study, in this Thesis we have evaluated: (1) the effect of the application of wastes from the winery and distillery industries on N dynamics from the agronomic and environmental viewpoint in a vulnerable zone; and (2) the factors that influence P availability in soils after the application of organic wastes. With this purposes, incubations were carried out in laboratory conditions as well as field trials that allow to assess the dynamic of these nutrients in real conditions. Soil incubations under controlled moisture and temperature conditions to determine N mineralization are commonly used to estimate N availability for crops together with the environmental risk. Therefore, a laboratory incubation was conducted in order to determine the N mineralization rate of a compost made from wastes generated in the winery and distillery industries, widely distributed in Castilla-La Mancha, a region with significant problems of aquifers contamination by nitrates. Three increasing doses of compost corresponding to 230, 460 and 690 kg of total N per hectare were mixed with a sandy clay loam soil collected in this area. The evolution of mineral N in soil over time was adjusted to a nonlinear regression model, obtaining low values of potentially mineralizable N and low constants of mineralization, indicating that it is a material resistant to mineralization with a slow release of N, with only 1.61, 1.33 and 1.21% of total N applied being mineralized with each increasing dose of compost (for a period of six months). Furthermore, N mineralization after the application of this material was also evaluated in field conditions by carrying out a N balance during two growing seasons (2011 and 2012) of a melon crop under drip irrigation, a crop and management very characteristic of the area of study. The mineralization constants obtained in the laboratory were adjusted to the actual temperatures observed in the field to predict N mineralized during each growing season, however, this model generally overestimated the N mineralization observed in the field, because of the influence of other factors not taken into account for this prediction, as N accumulated in soil, the plant effect or the fluctuations of temperature and moisture. The fitting of the laboratory data to the model as well as the predictions of N mineralized in the field were better when considering N mineralized from the soil-compost mixture rather than when N mineralized from compost was isolated, underlining the important role of the soil on N mineralization from organic wastes. Since the area of study was declared vulnerable to nitrate pollution and is situated between different protected hydrological units, the risk of nitrate pollution after application of different doses compost was evaluated in the same field trial with melon under two irrigation regimes, irrigation adjusted to the crop needs (90 or 100% of the crop evapotranspiration (ETc)) or excedentary irrigation (120% ETc). Drainage was estimated weekly throughout the growing season by conducting a water balance, samples of the soil solution were taken and the concentration of nitrates was determined. To assess the risk of groundwater contamination associated with these practices, some environmental indices were used to determine the variation in the quality of drinking water (Impact Index (II)) and the nitrates concentration in the groundwater (Environmental Impact Index (EII)). To combine environmental parameters together with yield parameters, the Management Efficiency was calculated. It was observed that the application of compost under irrigation adjusted to the plant needs did not represent a higher risk of groundwater contamination even with the application of the highest doses. However, the application of large amounts of compost combined with an irrigation surplus represented an increase of N leaching during the growing season compared with the unamended plots, while no additional yield with respect to the adjusted irrigation strategy is obtained. The application of wastes derived from the winery and distillery industry as source of P was evaluated in calcareous soils characterized by a high P retention capacity, which in some cases limits the availability of this nutrient. Another incubation experiment was carried out using two soils with different texture, different calcium carbonate and iron contents and two levels of available P; to which different materials from these industries (with and without composting) were applied providing different amounts of P. Soil available P (Olsen P), pH and dissolved organic carbon were analyzed along time. At the end of the incubation, in order to study the changes in soil P status caused by the different residues, a fractionation of soil inorganic P was carried out, which was separated into soluble and weakly bound P (NaOH-NaCl- P), reductant soluble P or occluded in Fe oxides (CBD-P) and P precipitated as poorly soluble Ca-P (HCl-P); and the P retention capacity and degree of P saturation were determined as well. Given the calcareous nature of the soils, the influence of the amount of P applied with the organic wastes in soil available P only occurred at the beginning of the incubation period, while at the end of the trial the increase in soil available P equalled independently of the amount of P applied with each residue, increasing the P retained in the least soluble fraction when increasing P applied. Conversely, the application of less stabilized materials with a lower content of P resulted in an increase in the most labile P forms due to dissolution of P retained in the less labile fraction, demonstrating the influence of organic matter addition on soil P processes that control P availability in soil. As expected, the application of organic wastes increased the degree of P saturation in the soils, however the values obtained did not exceed the limits considered to pose a risk of water pollution. The influence of the application of organic wastes on inorganic and organic soil P forms was also studied in an acid loamy sand soil after long-term field application of cattle manure and biowaste compost and the combined application of compost and mineral fertilizer (triple superphosphate) in a crop rotation. Soil samples were collected 14 years after the establishment of the field experiment, and analyzed for soluble and available P, P sorption capacity, degree of P saturation and enzymatic activities (dehydrogenase, acid phosphatase and alkaline phosphatase). The different forms of organic P in soil were determined by using an enzyme addition technique, based on adding enzymes with different substrate specificities to NaOH-EDTA soil extracts, measuring the hydrolyzed P colorimetrically after an incubation period. The enzymes used were acid phosphatase, nuclease and phytase which allowed to identify hydrolyzable monoesters (monoester-like P) diesters (DNA-like P) and inositol hexakisphosphate (Ins6P-like P). The long-term application of organic wastes increased soil available P proportionally to the P applied with each type of fertilizer, assuming a higher risk of P losses given the high degree of P saturation of this soil. The application of organic wastes increased soil organic P resistant to enzymatic hydrolysis, but no influence was observed regarding the different forms of enzyme hydrolyzable organic P compared to those observed in the non-amended soil. Furthermore, the different forms of organic P applied with the organic wastes did not correspond to those analyzed in the soil which showed that these forms in soil are a result of multifaceted P turnover processes in soil affected by plants, microorganisms and abiotic factors. In this study, a correlation between Ins6P-like P and the microbial activity (dehydrogenase activity) of soil was found, which reinforces this claim. Finally, the application of organic wastes as a source of N and P in agriculture was evaluated agronomically in a real field scenario. A field experiment was established to evaluate the application of compost made from wine-distillery wastes in the same melon crop used in the experiments of N mineralization and leaching. In this experiment the application of three doses of compost were studied: 1 , 2 and 3 kg of compost per linear meter of plantation corresponding to 7, 13 and 20 tonnes of compost per hectare respectively; and the effect on plant growth, N and P accumulation in the plant as well as crop yield and quality was studied. The application of compost produced a slight increase in plant biomass accompanied by a significant improvement in crop yield with respect to the unamended plots, obtaining the maximum yield with the application of 2 kg of compost per linear meter. Although the potential effects of N and P were partially masked by other inputs of these nutrients in the system (high concentration of nitrates in the irrigation water and phosphoric acid supplied by fertigation), an effect of P was observed the first year of study resulting in a greater plant P accumulation and in an increase in the number of fruits in the amended plots. In addition, the higher accumulation of available N and P in the topsoil at the end of the growing season indicated the potential use of this material as source of these nutrients.

An��lisis de la cadena de valor, canales cortos de comercializaci��n y horticultura multifuncional como opciones de puesta en valor: Caso de la Huerta de Aranjuez

La Vega de Aranjuez ha sido desde hace siglos conocida por la notoriedad de sus jardines y huertas hist��ricas y tambi��n, en ��pocas m��s recientes, por ser la despensa de Madrid. A mediados del siglo XX, sin embargo, con las transformaciones que el sector agrario ha experimentado no s��lo a nivel local, sino a escala global, empez�� un proceso de declive que se ha acentuado en los ��ltimos a��os. Paralelamente, en el a��o 2001, la Unesco declara el Paisaje Cultural de Aranjuez, como Patrimonio de la Humanidad con un valor universal excepcional. Parte de lo que sustenta este reconocimiento a nivel internacional radica en las peculiaridades del paisaje que conforma la actividad agraria. El cambio de orientaci��n, eminentemente hortofrut��cola hacia cultivos extensivos y superficies en barbecho, y la p��rdida de importancia del sector, no han pasado desapercibidos para la administraci��n local y han sido varios los intentos de recuperaci��n y dinamizaci��n del sector en los ��ltimos a��os. La investigaci��n de la que es objeto esta Tesis Doctoral surgi�� por iniciativa del Ayuntamiento de Aranjuez, que en al a��o 2010 dese�� conocer la situaci��n del sector hort��cola en el municipio, para lo cual, encarg�� un estudio a la UPM-ETSIA. Para conocer la realidad desde una perspectiva integral, se plante�� abordar el an��lisis desde la perspectiva de Cadena de Valor. Las implicaciones de este concepto, su evoluci��n y su papel como instrumento de an��lisis de la cadena alimentaria, han sido revisadas y presentadas en el ep��grafe del Marco Conceptual. Por cadena de valor se entiende el conjunto de procesos desde el consumidor, a trav��s de los proveedores que proporcionan productos, servicios e informaci��n que a��aden valor hacia los clientes (Lambert & Cooper, 2000; Chen, 2004). Para el an��lisis de la situaci��n del sector hort��cola en Aranjuez, se procedi�� en varios pasos, los cuales constituyeron la primera fase de la investigaci��n y contemplaron lo siguiente: 1. La identificaci��n de los problemas y de las demandas de los actores de la cadena, realizando cortes transversales en el mercado a distintos niveles para conocer los puntos de vista de los operadores de la cadena (Gunasekaran & Patel ,2004; Rojas, 2009; Schiefer, 2007). Para ello se dise��aron cuestionarios y se dirigieron a representantes de cinco eslabones de la cadena presentes en el caso de estudio: Agricultores (15), Mayoristas (11), Detallistas (55), Consumidores (85) y Restaurantes (36), tanto en Aranjuez como en Madrid (un total de 202). 2. An��lisis D.A.F.O de cada uno de los eslabones y de la cadena completa, como herramienta para identificar y sintetizar la problem��tica y las potencialidades del sector. 3. An��lisis global de la Cadena de Valor mediante el M��todo de Organizaci��n Sectorial, seg��n Briz, de Felipe y Briz (2010), el cual permite estudiar aspectos de la estructura, la conducta y el funcionamiento de la cadena. 4. Jornada de an��lisis por parte de un Panel de Expertos en la sede de la Fundaci��n Foro Agrario, en la cual se presentaron las conclusiones del an��lisis de la cadena de valor y se plantearon estrategias para la dinamizaci��n del sector. Con los resultados del an��lisis en esta primera fase de la investigaci��n, se obtuvo una panor��mica de la cadena de valor. Algunos de los aspectos m��s destacados son los siguientes: ��� El eslab��n productivo en Aranjuez est�� muy atomizado y trabaja por lo general de forma independiente. Cultiva hasta veinte productos hort��colas diferentes, entre los cuales los frutales est��n casi en desaparici��n y hay poca presencia de producto ecol��gico. Le preocupan los precios poco estables y bajos y por lo general no trabaja con contratos. ���������El eslab��n mayorista pr��cticamente carece de presencia en Aranjuez y est�� representado en su mayor��a por operadores de Mercamadrid, los cuales demandan mayores vol��menes y mejor normalizaci��n de los productos hort��colas procedentes de Aranjuez. ��� El eslab��n detallista consultado es diverso (con representaci��n de comercios minoristas, supermercados e hipermercados) y tambi��n demanda mayores vol��menes de producci��n y mejoras en la normalizaci��n. Un 80% conoce los productos de Aranjuez, especialmente el esp��rrago y la fresa-fres��n citados en un 74% y 63% de los casos respectivamente. ��� En el eslab��n de consumidores, el 79% de los encuestados da importancia a la procedencia de los productos hort��colas y un 82% conoce los productos de la Huerta de Aranjuez, siendo los m��s consumidos el esp��rrago y el fres��n. Un 42% de los encuestados compra producto ecol��gico por razones de salud, sabor y buscando la ausencia de qu��micos. ��� El eslab��n de restaurantes es un gran consumidor de hortalizas, la gran mayor��a de los productos incluidos en el an��lisis se oferta en m��s del 75% de los casos. Las m��s presentes son tomate y esp��rrago. La fresa y el fres��n (en un 83% de los casos), y el esp��rrago (72%) seguido de la alcachofa (44%) son los productos de Aranjuez que m��s se conocen en el conjunto de los restaurantes entrevistados. El 75% de los restaurantes prefiere el producto fresco frente al procesado o congelado. La mayor��a de los restaurantes locales (92%) estar��a dispuesto a incluir en su carta una diferenciaci��n para los productos de Aranjuez. Sin embargo, en el resto de restaurantes el porcentaje es mucho menor (21%). Entre las conclusiones del an��lisis se evidenci�� que un 52% de las ventas de los agricultores se realizaba sin intermediarios y un 69% de los consumidores se manifestaba interesado en adquirir productos de Aranjuez directamente del campo a su casa. Se identific�� de esta manera que el acortamiento de la cadena se est�� utilizando como una forma de crear valor. Para profundizar en este aspecto, se plante�� una segunda fase en la investigaci��n. Adem��s de estudiar diversos aspectos de los canales cortos de comercializaci��n, se plante�� estudiar el enfoque multifuncional de la horticultura, como estrategia para poner en valor la Huerta ribere��a. Para dar una coherencia con la fase anterior, el planteamiento se realiz�� tambi��n desde la perspectiva de la cadena de valor, orientando la consulta hacia el eslab��n consumidor. De esta manera, se realiz�� una consulta mediante cuestionario a 221 consumidores sobre diferentes aspectos relativos a los Canales Cortos de Comercializaci��n (CCC) y la Horticultura Multifuncional (HM)1, lo cual permiti�� realizar un an��lisis cuantitativo de diferentes variables. Para completar la visi��n integral de la cadena corta, se seleccionaron 6 proyectos significativos que son ejemplos de diversas tipolog��as de canales cortos de comercializaci��n en Aranjuez y Madrid, como representantes del denominado eslab��n de ���Promotores de CCC��� y se consult�� tambi��n a la Asociaci��n de Productores de la Huerta de Aranjuez, constituida formalmente en el a��o 2014, como representante del eslab��n Productor. Para la obtenci��n de informaci��n, la cual tiene un car��cter cualitativo en el caso de estos dos eslabones de la cadena, se realizaron cuestionarios y Estudios de Caso de cada proyecto. Los cuestionarios de esta segunda fase de consulta a los eslabones de la cadena corta contuvieron cuestiones relativas a los canales cortos de comercializaci��n, tanto a nivel general (concepto de canal corto, puntos fuertes y ventajas que aportan, dificultades para su desarrollo, factores clave para su ��xito) como para el caso concreto de la Huerta de Aranjuez (perfil del consumidor, factores implicados en la compra de verduras, utilizaci��n de diversas modalidades de canal corto, relaci��n con las tecnolog��as de la informaci��n y comunicaci��n (TICs) y la producci��n ecol��gica o la importancia del factor confianza). Tambi��n aspectos relacionados con la Horticultura Multifuncional, como son, la valoraci��n de diferentes actividades o proyectos de car��cter agro-tur��stico, educativo, social o terap��utico, o la percepci��n del consumidor de las actividades de huerta como fuente de bienestar y como agente satisfactor de diversas necesidades humanas. Para completar la visi��n sobre estos dos temas, CCC y HM, se realiz�� una consulta mediante cuestionario a Expertos en el campo de los canales cortos de comercializaci��n, procedentes del ��mbito acad��mico, y a Profesionales en activo trabajando en proyectos de horticultura social y terap��utica. La informaci��n aportada, aunque tiene car��cter cualitativo, complementa el estudio ofreciendo la perspectiva acad��mica en el caso de los canales cortos y ampl��a la informaci��n sobre la horticultura multifuncional, tratando cuestiones relativas al desempe��o profesional o a la formaci��n existente en Espa��a en el campo de la horticultura social y terap��utica. Los resultados de esta segunda fase de la investigaci��n, entre otras cuestiones, evidenciaron que: ��� Los canales cortos de comercializaci��n implican mucho m��s que la simple reducci��n de intermediarios y comprenden una gran diversidad de tipolog��as. ��� Los casos estudiados, est��n enfocados en su mayor��a al producto ecol��gico y su funcionamiento est�� muy fundamentado en el uso de TICs y en el factor confianza. ��� En relaci��n a la compra de verduras en el ��mbito de los canales cortos, son aspectos muy valorados por el consumidor la calidad del producto, la rapidez y frescura con la que llega del campo a la mesa y que el Producto sea recogido en su punto ��ptimo de maduraci��n. ��� Las actividades en el ��mbito de la horticultura multifuncional son valoradas positivamente por los consumidores, siendo las m��s puntuadas las de huerto educativo, huerto terap��utico, seguidas de visitas guiadas y degustaciones de productos de huerta en restaurantes. ��� Por lo general existe una valoraci��n muy alta de la huerta como fuente de bienestar y de satisfacci��n de necesidades humanas b��sicas, especialmente las de una alimentaci��n saludable y de conexi��n con la naturaleza. Para terminar esta s��ntesis de la investigaci��n realizada, se presentan las principales conclusiones a nivel global de la Tesis, que son las siguientes: 1. La metodolog��a de cadena de valor ha resultado adecuada para conocer la complejidad y el funcionamiento del sector hort��cola arancetano desde una perspectiva integral. 2. La Huerta de Aranjuez cuenta con importantes fortalezas, sustentadas en la calidad de sus suelos y en la fama que mantienen sus productos, pero tambi��n debilidades. Esto supone poco volumen de producci��n, que dificulta la relaci��n con mayoristas y grandes detallistas. 3. El acortamiento de la cadena, mediante canales cortos de comercializaci��n se ha identificado como una forma de creaci��n de valor en la cadena. Existen oportunidades de abastecimiento a consumidores de Madrid mediante canales cortos, sin embargo, las modalidades que requieren mayor organizaci��n o requisitos de producci��n ecol��gica todav��a no est��n desarrolladas. 4. La producci��n ecol��gica podr��a ser una estrategia para crear valor pero todav��a es un m��todo de cultivo muy minoritario en la cadena productiva arancetana. 5. Las peculiaridades de la Huerta de Aranjuez propician la puesta en pr��ctica del enfoque multifuncional de la horticultura como v��a de desarrollo econ��mico. Los resultados apuntan a una posible demanda de servicios que contemplen actividades de horticultura de car��cter educativo, terap��utico y agro-tur��stico, conducidas por profesionales. Existe una percepci��n positiva sobre el potencial de la huerta como fuente de bienestar y de satisfacci��n de necesidades humanas b��sicas. 6. La puesta en marcha de proyectos empresariales en el ��mbito de la horticultura social es una apuesta interesante para crear valor en la huerta que ha sido valorada positivamente por los eslabones de la cadena corta consultados. 7. El campo de la Horticultura Multifuncional que contempla aspectos educativos, sociales y terap��uticos conforma una disciplina con posibilidades de desarrollo que en la investigaci��n se perciben como limitadas por la falta de profesionales y su acceso a una formaci��n adecuada en Espa��a. El estudio de los Canales Cortos de Comercializaci��n y de la Horticultura Multifuncional como v��as de puesta en valor en el caso de la Huerta de Aranjuez ha tenido un car��cter exploratorio y en gran parte cualitativo en esta Tesis Doctoral. Ambos conceptos han desvelado cierta complejidad y requieren de un mayor conocimiento en diversos aspectos para su puesta en pr��ctica con ��xito. Se abre, por tanto, un campo para futuras investigaciones que profundicen en estos ��mbitos. ABSTRACT La Vega de Aranjuez has been known for centuries for the reputation of its orchards and historic gardens and, more recently, as the pantry of Madrid. However, in the mid-twentieth century, with the transformations in agriculture, not only locally, but globally, began a process of decline that has been accentuated in recent years. Meanwhile, in 2001, Unesco declared Aranjuez Cultural Landscape, as a World Heritage Site with outstanding universal value. Part of what underpins this international recognition lies in the peculiarities of the landscape created by farming. The shift, from an eminently horticultural vocation to extensive field crops and fallow surfaces, and the loss of importance of the sector, have not gone unnoticed for local authorities and have been several attempts at recovery and revitalization of the sector in recent years. The beginning of this research came at the initiative of the municipality of Aranjuez, which in 2010 wanted to know the situation of the horticultural sector, for which he commissioned a study by the UPM-ETSIA. To know reality from an integral perspective, it was proposed to approach the analysis from the perspective of value chain. The implications of this concept, its evolution and its role as an instrument of analysis of the food chain, have been reviewed and presented in Chapter 3.2. The value chain concept refers to all the processes from the consumer, through suppliers who provide products, services and information that add value to customers (Lambert & Cooper, 2000; Chen, 2004). For the analysis of the situation of the horticultural sector in Aranjuez, which constituted the first phase of research, it proceeded in several steps: 1. Identifying the problems and demands of the actors in the chain, making transverse cuts in the market at different levels to meet the views of the chain operators (Gunasekaran & Patel , 2004; Rojas, 2009; Schiefer, 2007). Questionnaires were designed for it and went to representatives of the five links in the chain: Farmers (15), Wholesalers (11), Retailers (55), Consumers (85) and Restaurants (36), both in Aranjuez and Madrid (a total of 202). 2. SWOT analysis of each chain actor and of the whole supply chain, as a tool to identify and synthesize the problems and potential of the sector. 3. Analysis of the whole supply chain by Industrial Organization Method according to Briz et al. (2010), which allows to study aspects of the structure, conduct and performance of the chain. 4. Analysis by a Panel of Experts at Foro Agrario Foundation headquarters, where the conclusions of the analysis were presented and strategies for the revitalization of the sector were raised. The results of the analysis in this first phase of the research, presented an overview of the value chain. Some of the highlights are: - The productive sector in Aranjuez is very fragmented and usually works independently. With a wide variety of horticultural products (up to 20), fruit crops almost disappearing and little presence of organic product. Is concerned about the unstable and low prices and usually does not work with contracts. - The wholesale sector with virtually no presence in Aranjuez is represented mostly by Mercamadrid operators, who demand higher volumes and better standardization of horticultural products from Aranjuez. - The retailer sector is diversified (with representation from retailers, supermarkets and hypermarkets) and also demand higher production volumes and improved standardization. 80% know the products of Aranjuez, especially asparagus and strawberry-strawberry cited by 74% and 63% of cases respectively. - Among the consumers, 79% give importance to the origin of horticultural products and 82% know the products from Aranjuez, the most consumed asparagus and strawberries. 42% buy organic products for health, taste and absence of chemicals. - Restaurants are big consumers of vegetables, most of the products included in the analysis is offered in over 75% of cases. The most: tomato and asparagus. Strawberry (83% of cases), and asparagus (72%) followed by the artichoke (44%) are the products of Aranjuez more known in all the surveyed restaurants. 75% of the restaurants prefer fresh product against processed or frozen. Most local restaurants (92%) would be willing to include in their menu a differentiation for products of Aranjuez. However, for those restaurants from Madrid the percentage is much lower (21%). Among the conclusions of the analysis it showed that 52% of sales were realized from farmers without intermediaries and 69% of consumers expressed interest in acquiring products directly from field to table. It has been identified that the shortening of the chain is being used as a way to create value. To deepen this aspect, a second phase investigation arose. Besides studying various aspects of the short supply chains, it was also proposed to study the functional approach of horticulture as a strategy to add value. To provide consistency with the previous phase, the focus was also conducted from the perspective of the value chain, directing the query to consumers. Thus, again it was used the questionnaire as a methodological tool, and 221 consumers were asked about different aspects of the Short Suppy Chains (SSC) and Multifunctional Horticulture (MH)2, which allowed a quantitative analysis of several variables. To complete the comprehensive view of the short chain, 6 significant projects were selected as examples of different types of short supply chains in Aranjuez and Madrid, representing "SSC Promoters" and also the ���Asociaci��n de Productores de la Huerta de Aranjuez���, formally constituted in 2014, was asked representing the productive sector. The Study Case and again the questionnaire were elected as methodological tools in a qualitative analysis. The questionnaires of this second phase of research contained short supply chain issues, as a general topic (short supply chain concept, strengths and advantages they bring difficulties for its development, key factors success) and also refered to the case of Aranjuez (consumer profile, factors involved in the purchase of vegetables, use of several types of short supply chains, relation with information and communication technologies (ICTs) and organic production or the importance of trust in short supply chains). It also contemplated aspects of multifunctional horticulture, such as the valuation of different activities (agro-tourism, educational, social or therapeutic horticulture) and consumer perception about horticultural activities as a source of welfare and satisfactor of human needs. To complete the vision of these two issues, SSC and MH, experts in the field of short supply chains and professionals working in the field of social and therapeutic horticulture were asked. The qualitative information provided, complements the study offering a new perspective in the value chain analysis, such as those relating to job performance, the difficulties encountered or training existing in our country in the field of social and therapeutic horticulture. The results of this second phase of research showed that: Short supply chains involve much more than simply reducing intermediaries and cover a wide range of types. The cases studied are mostly focused on ecological product and its operation is heavily based on the use of ICTs and the trust factor. In connection with the purchase of vegetables in the field of short supply chains, product quality, speed and freshness with which comes from the field to the table and products picked at its peak maturation, are aspects highly valued by the consumer. Activities in the field of multifunctional horticulture are positively valued by consumers, the most scored: the educational garden, therapeutic garden, followed by guided tours and tastings of vegetables from Aranjuez in restaurants. Horticultural activities were highly valuated as a source of welfare and satisfaction of human needs, especially those of healthy eating and connection with nature. To complete this summary, the main conclusions of the research are presented as follows: 1. The value chain approach has been adequate to meet the complexity and operation of the horticultural sector in Aranjuez from a holistic perspective. 2. La Huerta de Aranjuez has important strengths, underpinned by the quality of its soils and fame that keep their products, but also weaknesses. This implies low volume of production, which makes difficult the link with wholesalers and large retailers. 3. The shortening of the chain by short supply chains has been identified as a way of creating value in the chain. Opportunities exist to supply consumers from Madrid by short supply chains, however, methods that require greater organization or requirements of organic production are not yet developed. 4. Organic production could be a strategy to create value but is not generally being implemented in the production chain. 5. The peculiarity of the Huerta de Aranjuez favours the implementation of the multifunctional approach as a means of economic development. The results point to a possible demand for multifunctional horticulture that include educational, therapeutic and agro-tourism activities. There is a positive perception of the potential of horticultural activities as a source of welfare and satisfaction of basic human needs. 6. The implementation of business projects in the field of social horticulture are an interesting way to create value that has been highly valued in the short supply chain. 7. The field of Multifunctional Horticulture which includes educational, social and therapeutic aspects, forms a discipline with possibilities of development, which in research are seen as limited by the lack of professionals and access to adequate training in our country. The study of Short Supply Chains and Multifunctional Horticulture as strategies to create value in the case of the Huerta de Aranjuez has an exploratory character and largely qualitative in this research. Both concepts have revealed some complexity and require greater knowledge in various aspects for successful implementation. It opens therefore a field for future research to deepen in these areas.

Desarrollos metodol��gicos y aplicaciones hacia el c��lculo de la peligrosidad s��smica en el ecuador continental y estudio de riesgo s��smico en la ciudad de Quito

En el presente trabajo de tesis se desarrolla, en primer lugar, un estudio de peligrosidad s��smica en Ecuador continental, siguiendo una metodolog��a probabilista zonificada. El estudio se plantea a escala regional y presenta como principales aportaciones: 1) la elaboraci��n de un Estado del Arte sobre Tect��nica y Geolog��a de Ecuador, concluyendo con la identificaci��n de las principales fuentes s��smicas; 2) La confecci��n de un Cat��logo S��smico de proyecto, recopilando informaci��n de distintas agencias, que ha sido homogeneizado a magnitud momento, Mw, depurado de r��plicas y premonitores y corregido por la falta de completitud para la estimaci��n de tasas en diferentes rangos de magnitud; 3) la propuesta de un nueva zonificaci��n s��smica, definiendo las zonas sismogen��ticas en tres reg��menes tect��nicos: cortical, subducci��n interfase y subducci��n in-slab; 4) la caracterizaci��n s��smica de cada zona estimando los par��metros de recurrencia y Magnitud M��xima (Mmax), considerando para este ��ltimo par��metro una distribuci��n de valores posibles en funci��n de la sismicidad y tect��nica, tras un exhaustivo an��lisis de los datos existentes; 5) la generaci��n de mapas de peligrosidad s��smica de Ecuador continental en t��rminos de aceleraci��n pico (PGA) y espectral SA (T= 1s) , en ambos casos para periodos de retorno (PR) de 475, 975 y 2475 a��os; 6) La estimaci��n de espectros de peligrosidad uniforme (UHS) y sismos de control mediante desagregaci��n de la peligrosidad, para PR de 475 y 2475 a��os en 4 capitales de provincia: Quito, Esmeraldas, Guayaquil y Loja. Una segunda parte del trabajo se destina al c��lculo del riesgo s��smico en el Barrio Mariscal Sucre de Quito, lo que supone incidir ya a una escala municipal. Como principales contribuciones de este trabajo se destacan: 1) definici��n del escenario s��smico que m��s contribuye a la peligrosidad en Quito, que actuar�� como input de c��lculo del riesgo; 2) caracterizaci��n de la acci��n s��smica asociada a ese escenario, incluyendo resultados de microzonaci��n y efecto local en la zona de estudio; 3) Elaboraci��n de una Base de Datos partiendo de informaci��n catastral e identificaci��n de las tipolog��as dominantes; 4) Asignaci��n de clases de vulnerabilidad y obtenci��n de porcentajes de da��o esperado en cada clase ante la acci��n s��smica definida previamente, con la consiguiente representaci��n de mapas de vulnerabilidad y da��o; 5) mapas de indicadores globales del riesgo s��smico; 6) Base de datos georreferenciada con toda la informaci��n generada en el estudio. Cabe destacar que el trabajo, aunque no formula nuevos m��todos, si plantea una metodolog��a integral de c��lculo del riesgo s��smico, incorporando avances en cada fase abordada, desde la estimaci��n de la peligrosidad o la definici��n de escenarios s��smicos con car��cter hibrido (probabilista-determinista), hasta la asignaci��n de vulnerabilidades y estimaci��n de escenarios de da��o. Esta tesis trata de presentar contribuciones hacia el mejor conocimiento de la peligrosidad s��smica en Ecuador y el riesgo s��smico en Quito, siendo uno de los primeros estudios de tesis que se desarrolla sobre estos temas en el pa��s. El trabajo puede servir de ejemplo y punto de partida para estudios futuros; adem��s de ser replicable en otras ciudades y municipios de Ecuador. -------------------- ABSTRACT: ------------------ This thesis first develops a study of seismic hazard in mainland Ecuador, following a zoned, probabilistic methodology. The study considers a regional scale and presents as main contributions: 1) The development of a State of Art on the Tectonics and Geology of Ecuador, concluding with the identification of the main seismic sources; 2) The creation of a Seismic Catalog project, collecting information from different agencies, which has been homogenized to Moment magnitude, Mw, purged from aftershocks and premonitories and corrected for the lack of completeness to estimate rates in different maggnitude ranges; 3) The proposal of a new seismic zoning, defining the seismogenic zones in three tectonic regimes: cortical, subduction interface and subduction in-slab; 4) The seismic characterization of each zone, estimating the parameters of recurrence and Maximum Magnitude (Mmax), considering the latter as a distribution of possible values, depending on the seismicity and tectonics, and after a thorough analysis of the existing data; 5) Seismic hazard maps of continental Ecuador in terms of peak ground acceleration (PGA) and spectral SA(T=1), and return periods (PR) of 475, 975 and 2475 years; 6) Uniform hazard spectra (UHS) and control earthquakes obtained by hazard disaggregation, for PR 475 and 2475 years in four provincial capitals: Quito, Esmeraldas, Guayaquil and Loja. The second section focuses on the calculation of seismic risk in the Quito Mariscal Sucre parish, which is already supposed to be influencing at a municipal level. The main contributions here are the: 1) Definition of the seismic scenario that contributes most to the hazard in Quito, which acts as an input in the risk calculation; 2) Characterization of the seismic action associated with that scenario, including results of micro-zoning and local effect in the study area; 3) Development of a database, based on cadastral data and identification of key typologies; 4) Allocation of vulnerability classes and obtaining percentages of damage expected in each class faced with the seismic action previously defined, with the consequent representation of maps of vulnerability and damage; 5) Global maps of seismic risk indicators; 6) Geo-referenced database with all the information generated in the study. It should be noted that although new methods are not prescribed, this study does set a comprehensive methodology for the calculation of seismic risk, incorporating advances in each phase approached, from the hazard estimation, or definition of seismic scenarios applying a hybrid (deterministic-probabilistic) method, to the allocation of vulnerabilities and estimation of damage scenarios. This thesis aims to present contributions leading to a better understanding of seismic hazard in Ecuador and seismic risk in Quito, and is one of the first studies in the country to develop such themes. This study can serve as an example and starting point for future studies, which could replicate this methodology in other cities and municipalities.

Automated wordlength optimization framework for multi-source statistical interval-based analysis of nonlinear systems with control-flow structures

El uso de aritm��tica de punto fijo es una opci��n de dise��o muy extendida en sistemas con fuertes restricciones de ��rea, consumo o rendimiento. Para producir implementaciones donde los costes se minimicen sin impactar negativamente en la precisi��n de los resultados debemos llevar a cabo una asignaci��n cuidadosa de anchuras de palabra. Encontrar la combinaci��n ��ptima de anchuras de palabra en coma fija para un sistema dado es un problema combinatorio NP-hard al que los dise��adores dedican entre el 25 y el 50 % del ciclo de dise��o. Las plataformas hardware reconfigurables, como son las FPGAs, tambi��n se benefician de las ventajas que ofrece la aritm��tica de coma fija, ya que ��stas compensan las frecuencias de reloj m��s bajas y el uso m��s ineficiente del hardware que hacen estas plataformas respecto a los ASICs. A medida que las FPGAs se popularizan para su uso en computaci��n cient��fica los dise��os aumentan de tama��o y complejidad hasta llegar al punto en que no pueden ser manejados eficientemente por las t��cnicas actuales de modelado de se��al y ruido de cuantificaci��n y de optimizaci��n de anchura de palabra. En esta Tesis Doctoral exploramos distintos aspectos del problema de la cuantificaci��n y presentamos nuevas metodolog��as para cada uno de ellos: Las t��cnicas basadas en extensiones de intervalos han permitido obtener modelos de propagaci��n de se��al y ruido de cuantificaci��n muy precisos en sistemas con operaciones no lineales. Nosotros llevamos esta aproximaci��n un paso m��s all�� introduciendo elementos de Multi-Element Generalized Polynomial Chaos (ME-gPC) y combin��ndolos con una t��cnica moderna basada en Modified Affine Arithmetic (MAA) estad��stico para as�� modelar sistemas que contienen estructuras de control de flujo. Nuestra metodolog��a genera los distintos caminos de ejecuci��n autom��ticamente, determina las regiones del dominio de entrada que ejercitar��n cada uno de ellos y extrae los momentos estad��sticos del sistema a partir de dichas soluciones parciales. Utilizamos esta t��cnica para estimar tanto el rango din��mico como el ruido de redondeo en sistemas con las ya mencionadas estructuras de control de flujo y mostramos la precisi��n de nuestra aproximaci��n, que en determinados casos de uso con operadores no lineales llega a tener tan solo una desviaci��n del 0.04% con respecto a los valores de referencia obtenidos mediante simulaci��n. Un inconveniente conocido de las t��cnicas basadas en extensiones de intervalos es la explosi��n combinacional de t��rminos a medida que el tama��o de los sistemas a estudiar crece, lo cual conlleva problemas de escalabilidad. Para afrontar este problema presen tamos una t��cnica de inyecci��n de ruidos agrupados que hace grupos con las se��ales del sistema, introduce las fuentes de ruido para cada uno de los grupos por separado y finalmente combina los resultados de cada uno de ellos. De esta forma, el n��mero de fuentes de ruido queda controlado en cada momento y, debido a ello, la explosi��n combinatoria se minimiza. Tambi��n presentamos un algoritmo de particionado multi-v��a destinado a minimizar la desviaci��n de los resultados a causa de la p��rdida de correlaci��n entre t��rminos de ruido con el objetivo de mantener los resultados tan precisos como sea posible. La presente Tesis Doctoral tambi��n aborda el desarrollo de metodolog��as de optimizaci��n de anchura de palabra basadas en simulaciones de Monte-Cario que se ejecuten en tiempos razonables. Para ello presentamos dos nuevas t��cnicas que exploran la reducci��n del tiempo de ejecuci��n desde distintos ��ngulos: En primer lugar, el m��todo interpolativo aplica un interpolador sencillo pero preciso para estimar la sensibilidad de cada se��al, y que es usado despu��s durante la etapa de optimizaci��n. En segundo lugar, el m��todo incremental gira en torno al hecho de que, aunque es estrictamente necesario mantener un intervalo de confianza dado para los resultados finales de nuestra b��squeda, podemos emplear niveles de confianza m��s relajados, lo cual deriva en un menor n��mero de pruebas por simulaci��n, en las etapas iniciales de la b��squeda, cuando todav��a estamos lejos de las soluciones optimizadas. Mediante estas dos aproximaciones demostramos que podemos acelerar el tiempo de ejecuci��n de los algoritmos cl��sicos de b��squeda voraz en factores de hasta x240 para problemas de tama��o peque��o/mediano. Finalmente, este libro presenta HOPLITE, una infraestructura de cuantificaci��n automatizada, flexible y modular que incluye la implementaci��n de las t��cnicas anteriores y se proporciona de forma p��blica. Su objetivo es ofrecer a desabolladores e investigadores un entorno com��n para prototipar y verificar nuevas metodolog��as de cuantificaci��n de forma sencilla. Describimos el flujo de trabajo, justificamos las decisiones de dise��o tomadas, explicamos su API p��blica y hacemos una demostraci��n paso a paso de su funcionamiento. Adem��s mostramos, a trav��s de un ejemplo sencillo, la forma en que conectar nuevas extensiones a la herramienta con las interfaces ya existentes para poder as�� expandir y mejorar las capacidades de HOPLITE. ABSTRACT Using fixed-point arithmetic is one of the most common design choices for systems where area, power or throughput are heavily constrained. In order to produce implementations where the cost is minimized without negatively impacting the accuracy of the results, a careful assignment of word-lengths is required. The problem of finding the optimal combination of fixed-point word-lengths for a given system is a combinatorial NP-hard problem to which developers devote between 25 and 50% of the design-cycle time. Reconfigurable hardware platforms such as FPGAs also benefit of the advantages of fixed-point arithmetic, as it compensates for the slower clock frequencies and less efficient area utilization of the hardware platform with respect to ASICs. As FPGAs become commonly used for scientific computation, designs constantly grow larger and more complex, up to the point where they cannot be handled efficiently by current signal and quantization noise modelling and word-length optimization methodologies. In this Ph.D. Thesis we explore different aspects of the quantization problem and we present new methodologies for each of them: The techniques based on extensions of intervals have allowed to obtain accurate models of the signal and quantization noise propagation in systems with non-linear operations. We take this approach a step further by introducing elements of MultiElement Generalized Polynomial Chaos (ME-gPC) and combining them with an stateof- the-art Statistical Modified Affine Arithmetic (MAA) based methodology in order to model systems that contain control-flow structures. Our methodology produces the different execution paths automatically, determines the regions of the input domain that will exercise them, and extracts the system statistical moments from the partial results. We use this technique to estimate both the dynamic range and the round-off noise in systems with the aforementioned control-flow structures. We show the good accuracy of our approach, which in some case studies with non-linear operators shows a 0.04 % deviation respect to the simulation-based reference values. A known drawback of the techniques based on extensions of intervals is the combinatorial explosion of terms as the size of the targeted systems grows, which leads to scalability problems. To address this issue we present a clustered noise injection technique that groups the signals in the system, introduces the noise terms in each group independently and then combines the results at the end. In this way, the number of noise sources in the system at a given time is controlled and, because of this, the combinato rial explosion is minimized. We also present a multi-way partitioning algorithm aimed at minimizing the deviation of the results due to the loss of correlation between noise terms, in order to keep the results as accurate as possible. This Ph.D. Thesis also covers the development of methodologies for word-length optimization based on Monte-Carlo simulations in reasonable times. We do so by presenting two novel techniques that explore the reduction of the execution times approaching the problem in two different ways: First, the interpolative method applies a simple but precise interpolator to estimate the sensitivity of each signal, which is later used to guide the optimization effort. Second, the incremental method revolves on the fact that, although we strictly need to guarantee a certain confidence level in the simulations for the final results of the optimization process, we can do it with more relaxed levels, which in turn implies using a considerably smaller amount of samples, in the initial stages of the process, when we are still far from the optimized solution. Through these two approaches we demonstrate that the execution time of classical greedy techniques can be accelerated by factors of up to ��240 for small/medium sized problems. Finally, this book introduces HOPLITE, an automated, flexible and modular framework for quantization that includes the implementation of the previous techniques and is provided for public access. The aim is to offer a common ground for developers and researches for prototyping and verifying new techniques for system modelling and word-length optimization easily. We describe its work flow, justifying the taken design decisions, explain its public API and we do a step-by-step demonstration of its execution. We also show, through an example, the way new extensions to the flow should be connected to the existing interfaces in order to expand and improve the capabilities of HOPLITE.

CLIMA ORGANIZACIONAL E BURNOUT: UM ESTUDO COM SERVIDORES P��BLICOS FEDERAIS

As condi����es inadequadas vivenciadas nas organiza����es afligem n��o s�� os trabalhadores da iniciativa privada, pois s��o igualmente encontradas no segmento estatal, contrariando a expectativa de que o aparato governamental eliminaria as condi����es insalubres e criaria outras melhores nas quais prevalecesse �� promo����o de sa��de. Diante desse panorama questionou-se porque, uma vez que, pelo menos do ponto de vista da sociedade leiga, esses servidores est��o submetidos a condi����es privilegiadas de trabalho. O presente estudo objetivou identificar e descrever poss��veis rela����es entre o clima organizacional e o burnout em servidores p��blicos de uma institui����o federal de ensino. Objetivou-se ainda descrever o clima organizacional predominante. A pesquisa realizada teve cunho quantitativo, tipo estudo de caso e explorat��ria. A coleta de dados deu-se por meio das escalas ECO (escala de clima organizacional), ECB (escala de caracteriza����o do burnout) e um question��rio sociodemogr��fico, todos os instrumentos autoaplic��veis eletronicamente dispon��veis �� institui����o. Participaram do estudo 201 servidores p��blicos federais, com idade m��dia de 37 anos, majoritariamente de n��vel superior e casados. Os resultados revelaram que cerca de um quarto dos participantes raramente experimentaram burnout, no entanto outra quarta parte deles frequentemente experimentaram altos n��veis de burnout, resultado bastante expressivo. Os servidores perceberam clima organizacional mediano, destacando-se a boa coes��o entre os colegas de trabalho e a percep����o de baixa recompensa. Merece destaque a grande dispers��o entre as percep����es de clima, o que permite inferir haver subclimas n��o identificados nesta investiga����o, possivelmente ocasionados por uma for��a de clima fraca e pela participa����o dos servidores de unidades de ensino geograficamente distintas, geridas por gestores locais com relativa autonomia. Os resultados dos c��lculos de correla����o revelaram que, quanto menos os participantes percebem apoio da chefia e da organiza����o, coes��o entre colegas, e mais controle/press��o, mais exaustos se sentem, mais desumanizam as pessoas com quem tratam e mais se decepcionam no trabalho e vice-versa. Conforto f��sico menor est�� associado a maior desumaniza����o e a mais decep����o no trabalho e vice-versa; e que controle/press��o, relaciona-se positiva e fracamente com desumaniza����o e vice-versa. Desta forma, a hip��tese de que existe associa����o entre burnout e clima organizacional foi confirmada. Os resultados tamb��m revelaram que os servidores com burnout, perceberam pior clima organizacional que os seus pares sem burnout, confirmando a segunda hip��tese. Esses servidores tamb��m se mostraram neutros quanto �� percep����o de apoio da chefia e conforto f��sico; n��o percebem controle press��o, nem recompensa; todavia percebem coes��o entre os colegas. Esses resultados sugerem que os participantes t��m se apoiado nessas rela����es para suportar a indiferen��a e aus��ncia de est��mulos experimentados no trabalho. Os resultados obtidos nesse estudo permitiram concluir que o clima organizacional �� fraco, provavelmente influenciado por uma cultura organizacional fraca, explicando a heterogeneidade da percep����o do clima organizacional pelos servidores. Al��m disso, embora haja burnout entre poucos participantes, h�� que se atentar que cerca de um quarto deles, encontra-se acometido desta s��ndrome e isto poder�� contagiar os demais.

Novel dimeric interface and electrostatic recognition in bacterial���Cu,Zn superoxide���dismutase

Eukaryotic Cu,Zn superoxide dismutases (CuZnSODs) are antioxidant enzymes remarkable for their unusually stable ��-barrel fold and dimer assembly, diffusion-limited catalysis, and electrostatic guidance of their free radical substrate. Point mutations of CuZnSOD cause the fatal human neurodegenerative disease amyotrophic lateral sclerosis. We determined and analyzed the first crystallographic structure (to our knowledge) for CuZnSOD from a prokaryote, Photobacterium leiognathi, a luminescent symbiont of Leiognathid fish. This structure, exemplifying prokaryotic CuZnSODs, shares the active-site ligand geometry and the topology of the Greek key ��-barrel common to the eukaryotic CuZnSODs. However, the ��-barrel elements recruited to form the dimer interface, the strategy used to forge the channel for electrostatic recognition of superoxide radical, and the connectivity of the intrasubunit disulfide bond in P. leiognathi CuZnSOD are discrete and strikingly dissimilar from those highly conserved in eukaryotic CuZnSODs. This new CuZnSOD structure broadens our understanding of structural features necessary and sufficient for CuZnSOD activity, highlights a hitherto unrecognized adaptability of the Greek key ��-barrel building block in evolution, and reveals that prokaryotic and eukaryotic enzymes diverged from one primordial CuZnSOD and then converged to distinct dimeric enzymes with electrostatic substrate guidance.

The roles of language processing in a spoken language interface.

This paper provides an overview of the colloquium's discussion session on natural language understanding, which followed presentations by M. Bates [Bates, M. (1995) Proc. Natl. Acad. Sci. USA 92, 9977-9982] and R. C. Moore [Moore, R. C. (1995) Proc. Natl. Acad. Sci. USA 92, 9983-9988]. The paper reviews the dual role of language processing in providing understanding of the spoken input and an additional source of constraint in the recognition process. To date, language processing has successfully provided understanding but has provided only limited (and computationally expensive) constraint. As a result, most current systems use a loosely coupled, unidirectional interface, such as N-best or a word network, with natural language constraints as a postprocess, to filter or resort the recognizer output. However, the level of discourse context provides significant constraint on what people can talk about and how things can be referred to; when the system becomes an active participant, it can influence this order. But sources of discourse constraint have not been extensively explored, in part because these effects can only be seen by studying systems in the context of their use in interactive problem solving. This paper argues that we need to study interactive systems to understand what kinds of applications are appropriate for the current state of technology and how the technology can move from the laboratory toward real applications.