Towards a fuzzy-based multi-classifier selection module for activity recognition applications

Performing activity recognition using the information provided by the different sensors embedded in a smartphone face limitations due to the capabilities of those devices when the computations are carried out in the terminal. In this work a fuzzy inference module is implemented in order to decide which classifier is the most appropriate to be used at a specific moment regarding the application requirements and the device context characterized by its battery level, available memory and CPU load. The set of classifiers that is considered is composed of Decision Tables and Trees that have been trained using different number of sensors and features. In addition, some classifiers perform activity recognition regardless of the on-body device position and others rely on the previous recognition of that position to use a classifier that is trained with measurements gathered with the mobile placed on that specific position. The modules implemented show that an evaluation of the classifiers allows sorting them so the fuzzy inference module can choose periodically the one that best suits the device context and application requirements.

Short paper: From streaming data to linked data. A case study with bike sharing systems

Current methods and tools that support Linked Data publication have mainly focused so far on static data, without considering the growing amount of streaming data available on the Web. In this paper we describe a case study that involves the publication of static and streaming Linked Data for bike sharing systems and related entities. We describe some of the challenges that we have faced, the solutions that we have explored, the lessons that we have learned, and the opportunities that lie in the future for exploiting Linked Stream Data.

Procesos de dualización en la sociedad de la información: algunas polémicas públicas de índole tecnológica

La tecnología ha cambiado el mundo, pero las consecuencias de estos cambios en la sociedad no siempre se han pronosticado bien. Las Tecnologías de la Información transformaron el método de producción industrial. La nueva industria produce ideas y conceptos, no objetos. Este cambio ha dado como resultado una sociedad dualizada, ha desaparecido gran parte de la clase media y han aumentado las diferencias entre la clase alta y la baja. Las exigencias educativas de los nuevos puestos de trabajo innovadores son superiores a los de la industria tradicional, pero inferiores en los puestos de trabajo de producción. Además, el número de puestos de trabajo disponibles de este tipo es menor que en la industria tradicional, se necesita menos mano de obra, los procesos se pueden automatizar, las tareas mecánicas se aprenden en poco tiempo y son trabajos temporales, cuyo número dependerá de la demanda global. Para que el proceso de innovación funcione, las empresas se reúnen en las zonas financieras de grandes ciudades, como Nueva York o Londres, que fueron las primeras con acceso a las redes de telecomunicación. De esta manera se producen sinergias que contribuyen a mejorar el proceso innovador global. Estas ideas y conceptos que cambian el mundo necesitan de este entorno de producción, que no puede ser replicado, y son tan importantes que su acceso está restringido para la mayor parte del mundo por distintos mecanismos de control. El despliegue de las redes de telecomunicaciones inalámbricas ha sido enorme en los últimos años. El cliente busca llamar desde cualquier lugar y llevar un acceso a Internet en teléfono móvil. Para conseguirlo, las operadoras de telefonía móvil necesitan poner antenas de telefonía móvil en las ciudades, pero la instalación cerca de edificios no está siendo fácil. Pocos quieren tener una antena cerca por los problemas de salud de las personas que padecen los que ya viven o trabajan cerca de una. Los efectos del electromagnetismo en los seres humanos no están claros y provocan desconfianza hacia las antenas. La digitalización de los contenidos, que ha sido necesaria para transmitir contenido en Internet, permite que cualquier persona con un ordenador y una conexión a Internet pueda publicar un disco, una película o un libro. Pero esa persona también puede copiar los originales y enviarlos a cualquier lugar del mundo sin el permiso del autor. Con el fin de controlar la copia no autorizada, los derechos de autor se están usando para cambiar leyes e incluir sistemas de censura en Internet. Estos sistemas permiten a los autores eliminar el contenido ilegal, pero también pueden ser usados para censurar cualquier tipo de información. El control de la información es poder y usarlo de una manera o de otra afecta a todo el planeta. El problema no es la tecnología, que es solo una herramienta, es la forma que tienen los gobiernos y las grandes empresas de usarlo. Technology has changed the world, but the consequences of these changes in society have not always been well predicted. The Information Technology transformed the industrial production method. The new industry produces ideas and concepts, not objects. This change has resulted in a society dualized, most of the middle class has disappeared and the differences between high and low class have increased. The educational requirements of new innovative jobs are higher than the ones of the traditional industry, but lower in production jobs. Moreover, the number of available jobs of this type is lower than in the traditional industry, it takes less manpower, processes can be automated, mechanical tasks are learned in a short time and jobs are temporary, whose number depends on global demand. For the innovation process works, companies meet in the business districts of large cities, like New York or London, which were the first with access to telecommunications networks. This will produce synergies that improve the overall innovation process. These ideas and concepts that change the world need this production environment, which cannot be replicated, and are so important that their access is restricted to most of the world by different control mechanisms. The deploy of wireless telecommunications networks has been enormous in recent years. The client seeks to call from anywhere and to bring Internet access in his mobile phone. To achieve this, mobile operators need to put cell towers in cities, but the installation near buildings is not being easy. Just a few want to have an antenna closely because of the health problems suffered by people who already live or work near one. The effects of electromagnetism in humans are unclear and cause distrust of antennas. The digitization of content, which has been necessary to transmit Internet content, allows anyone with a computer and an Internet connection to be able to publish an album, a movie or a book. But that person can also copy the originals and send them anywhere in the world without the author's permission. In order to control the unauthorized copying, copyright is being used to change laws and include Internet censorship systems. These systems allow authors to eliminate illegal content, but may also be used to censor any information. The control of knowledge is power and using it in one way or another affects the whole planet. The problem is not technology, which is just a tool, but the way that governments and large corporations use it.

Open Technologies for prototyping the Internet of Things

The worldwide "hyper-connection" of any object around us is the challenge that promises to cover the paradigm of the Internet of Things. If the Internet has colonized the daily life of more than 2000 million1 people around the globe, the Internet of Things faces of connecting more than 100000 million2 "things" by 2020. The underlying Internet of Things’ technologies are the cornerstone that promises to solve interrelated global problems such as exponential population growth, energy management in cities, and environmental sustainability in the average and long term. On the one hand, this Project has the goal of knowledge acquisition about prototyping technologies available in the market for the Internet of Things. On the other hand, the Project focuses on the development of a system for devices management within a Wireless Sensor and Actuator Network to offer some services accessible from the Internet. To accomplish the objectives, the Project will begin with a detailed analysis of various “open source” hardware platforms to encourage creative development of applications, and automatically extract information from the environment around them for transmission to external systems. In addition, web platforms that enable mass storage with the philosophy of the Internet of Things will be studied. The project will culminate in the proposal and specification of a service-oriented software architecture for embedded systems that allows communication between devices on the network, and the data transmission to external systems. Furthermore, it abstracts the complexities of hardware to application developers. RESUMEN. La “hiper-conexión” a nivel mundial de cualquier objeto que nos rodea es el desafío al que promete dar cobertura el paradigma de la Internet de las Cosas. Si la Internet ha colonizado el día a día de más de 2000 millones1 de personas en todo el planeta, la Internet de las Cosas plantea el reto de conectar a más de 100000 millones2 de “cosas” para el año 2020. Las tecnologías subyacentes de la Internet de las Cosas son la piedra angular que prometen dar solución a problemas globales interrelacionados como el crecimiento exponencial de la población, la gestión de la energía en las ciudades o la sostenibilidad del medioambiente a largo plazo. Este Proyecto Fin de Carrera tiene como principales objetivos por un lado, la adquisición de conocimientos acerca de las tecnologías para prototipos disponibles en el mercado para la Internet de las Cosas, y por otro lado el desarrollo de un sistema para la gestión de dispositivos de una red inalámbrica de sensores que ofrezcan unos servicios accesibles desde la Internet. Con el fin de abordar los objetivos marcados, el proyecto comenzará con un análisis detallado de varias plataformas hardware de tipo “open source” que estimulen el desarrollo creativo de aplicaciones y que permitan extraer de forma automática información del medio que les rodea para transmitirlo a sistemas externos para su posterior procesamiento. Por otro lado, se estudiarán plataformas web identificadas con la filosofía de la Internet de las Cosas que permitan el almacenamiento masivo de datos que diferentes plataformas hardware transfieren a través de la Internet. El Proyecto culminará con la propuesta y la especificación una arquitectura software orientada a servicios para sistemas empotrados que permita la comunicación entre los dispositivos de la red y la transmisión de datos a sistemas externos, así como facilitar el desarrollo de aplicaciones a los programadores mediante la abstracción de la complejidad del hardware.

Unattended motion detection system based on the mammalian retina

Sensing systems in living bodies offer a large variety of possible different configurations and philosophies able to be emulated in artificial sensing systems. Motion detection is one of the areas where different animals adopt different solutions and, in most of the cases, these solutions reflect a very sophisticated form. One of them, the mammalian visual system, presents several advantages with respect to the artificial ones. The main objective of this paper is to present a system, based on this biological structure, able to detect motion, its sense and its characteristics. The configuration adopted responds to the internal structure of the mammalian retina, where just five types of cells arranged in five layers are able to differentiate a large number of characteristics of the image impinging onto it. Its main advantage is that the detection of these properties is based purely on its hardware. A simple unit, based in a previous optical logic cell employed in optical computing, is the basis for emulating the different behaviors of the biological neurons. No software is present and, in this way, no possible interference from outside affects to the final behavior. This type of structure is able to work, once the internal configuration is implemented, without any further attention. Different possibilities are present in the architecture to be presented: detection of motion, of its direction and intensity. Moreover, some other characteristics, as symmetry may be obtained.

SMArc: a proposal for a smart, semantic middleware architecture focused on Smart City energy management

Among the main features that are intended to become part of what can be expected from the Smart City, one of them should be an improved energy management system, in order to benefit from a healthier relation with the environment, minimize energy expenses, and offer dynamic market opportunities. A Smart Grid seems like a very suitable infrastructure for this objective, as it guarantees a two-way information flow that will provide the means for energy management enhancement. However, to obtain all the required information, another entity must care about all the devices required to gather the data. What is more, this entity must consider the lifespan of the devices within the Smart Grid—when they are turned on and off or when new appliances are added—along with the services that devices are able to provide. This paper puts forward SMArc—an acronym for semantic middleware architecture—as a middleware proposal for the Smart Grid, so as to process the collected data and use it to insulate applications from the complexity of the metering facilities and guarantee that any change that may happen at these lower levels will be updated for future actions in the system.

Sistemas de gestión de sensores mediante tecnologías M2M

En el proyecto se lleva a cabo un estudio práctico sobre dos escenarios donde intervienen dispositivos relacionados con el Internet de las cosas. También se puede situar como una solución de comunicación M2M. Comunicación máquina a máquina implica un sistema central que es capaz de conectarse con otros sistemas en varios lugares. La conexión permite que el sistema central recoja o envíe datos a cada lugar remoto para su procesamiento. El primer escenario consta de la configuración y montaje de un microcontrolador conocido como Waspmote que se encarga de recoger variables atmosféricas gracias a un conjunto de sensores y enviar los datos a un router multiprotocolo Meshlium mediante tecnología Zigbee, un tipo de red orientada a redes de sensores. Este montaje tiene como fin instalar una estación meteorológica en el campus de la universidad y poder almacenar y administrar sus datos. La segunda parte dos dispositivos de hardware libre como son un Arduino con capacidad GPRS y una RaspberryPi conectada a la red cableada enviaran datos por ejemplo de temperatura y luminosidad a una red social de sensores conocida como Xively, gestionaremos nuestros dispositivos sobre esta plataforma gratuita, que nos permite dar de alta dispositivos, almacenar y representar los datos en tiempo real y consultarlos vía Web o mediante una aplicación móvil realizada para este caso por medio de funciones ofrecidas por Xively. He diseñado una aplicación Android que permite la consulta de datos y administración de sensores por un usuario, intenta abstraer al usuario de la complejidad técnica y acercar los objetos conectados, en este caso sensores. Se han detallado las configuraciones y el proceso de instalación de todos los dispositivos. Se explican conceptos para entender las tecnologías de comunicación, Zigbee y Http, este protocolo participara a nivel de aplicación realizando peticiones o enviando datos, administrando la capacidad y por tanto ahorro. ABSTRACT. The project takes a practical study on two scenarios which involved related to the Internet of Things devices. It can also be placed as a M2M communication solution. Machine to machine communication involves a central system that is able to connect with other systems in several places. The connection allows the central system to collect or send data to each remote location for processing. The first stage consists of the configuration and setup of a microcontroller known as Waspmote which is responsible to collect atmospheric variables by a set of sensors and send the data to a multiprotocol router Meshlium by Zigbee technology, a type of sensor networks oriented network. This assembly aims to set up a weather station on the campus of the university and to store and manage their data. The second part two devices free hardware like Arduino with GPRS capacity and RaspberryPi connected to the wired network send data, temperature and luminosity to a social network of sensors known as Xively, manage our devices on this free platform, which allows us to register devices, store and display data in real time and consult the web or through a mobile application on this case by means of functions offered by Xively. I have designed an Android application that allows data consultation and management of sensors by a user, the user tries to abstract the technical complexity and bring the connected objects, in this case sensors. Were detailed settings and the installation of all devices. Concepts are explained to understand communication technologies, Zigbee and Http, this protocol participate performing application-level requests or sending data, managing capacity and therefore savings.

Integración de SSN con una ontología de servicios

Los servicios en red que conocemos actualmente están basados en documentos y enlaces de hipertexto que los relacionan entre sí sin aportar verdadera información acerca de los contenidos que representan. Podría decirse que se trata de “una red diseñada por personas para ser interpretada por personas”. El objetivo principal de los últimos años es encaminar esta red hacia una web de conocimiento, en la que la información pueda ser interpretada por agentes computerizados de manera automática. Para llevar a cabo esta transformación es necesaria la utilización de nuevas tecnologías especialmente diseñadas para la descripción de contenidos como son las ontologías. Si bien las redes convencionales están evolucionando, no son las únicas que lo están haciendo. El rápido crecimiento de las redes de sensores y el importante aumento en el número de dispositivos conectados a internet, hace necesaria la incorporación de tecnologías de la web semántica a este tipo de redes. Para la realización de este Proyecto de Fin de Carrera se utilizará la ontología SSN, diseñada para la descripción semántica de sensores y las redes de las que forman parte con el fin de permitir una mejor interacción entre los dispositivos y los sistemas que hacen uso de ellos. El trabajo desarrollado a lo largo de este Proyecto de Fin de Carrera gira en torno a esta ontología, siendo el principal objetivo la generación semiautomática de código a partir de un modelo de sistemas descrito en función de las clases y propiedades proporcionadas por SSN. Para alcanzar este fin se dividirá el proyecto en varias partes. Primero se realizará un análisis de la ontología mencionada. A continuación se describirá un sistema simulado de sensores y por último se implementarán las aplicaciones para la generación automática de interfaces y la representación gráfica de los dispositivos del sistema a partir de la representación del éste en un fichero de tipo OWL. ABSTRACT. The web we know today is based on documents and hypertext links that relate these documents with each another, without providing consistent information about the contents they represent. It could be said that its a network designed by people to be used by people. The main goal of the last couple of years is to guide this network into a web of knowledge, where information can be automatically processed by machines. This transformation, requires the use of new technologies specially designed for content description such as ontologies. Nowadays, conventional networks are not the only type of networks evolving. The use of sensor networks and the number of sensor devices connected to the Internet is rapidly increasing, making the use the integration of semantic web technologies to this kind of networks completely necessary. The SSN ontology will be used for the development of this Final Degree Dissertation. This ontology was design to semantically describe sensors and the networks theyre part of, allowing a better interaction between devices and the systems that use them. The development carried through this Final Degree Dissertation revolves around this ontology and aims to achieve semiautomatic code generation starting from a system model described based on classes and properties provided by SSN. To reach this goal, de Dissertation will be divided in several parts. First, an analysis about the mentioned ontology will be made. Following this, a simulated sensor system will be described, and finally, the implementation of the applications will take place. One of these applications will automatically generate de interfaces and the other one will graphically represents the devices in the sensor system, making use of the system representation in an OWL file.

Caracterización no destructiva del proceso de curado en materiales cementicios

La calidad del hormigón prefabricado se determina mediante ensayos de rotura a compresión en probetas transcurridos los 28 días de curado, según establece la EHE-08. Sin embargo, en la plantas de prefabricados es necesario además saber cuándo el hormigón está listo para ser procesado (destensado, cortado, trasladado), por lo que es necesario hacer ensayos de resistencia a la compresión entre las 48 y 72 horas, este tiempo se determina a partir de la experiencia previa adquirida y depende de las condiciones de cada planta. Si las probetas no han alcanzado el valor establecido, normalmente debido a un cambio en las condiciones climatológicas o en los materiales utilizados como el tipo de cemento o agregados, la solución adoptada suele ser dejar curar el material más horas en la pista para que alcance la resistencia necesaria para ser procesado. Si sigue sin alcanzarla, lo cual sucede muy ocasionalmente, se intenta analizar cuál ha sido el motivo, pudiéndose tirar toda la producción de ese día si se comprueba que ha sido un fallo en la fabricación de la línea, y no un fallo de la probeta. Por tanto, esta metodología de control de calidad, basada en técnicas destructivas, supone dos tipos de problemas, costes y representatividad. Los métodos no destructivos que más se han aplicado para caracterizar el proceso de curado del hormigón son los ultrasónicos y la medida de la temperatura como se recoge en la bibliografía consultada. Hay diferentes modelos que permiten establecer una relación entre la temperatura y el tiempo de curado para estimar la resistencia a compresión del material, y entre la velocidad de propagación ultrasónica y la resistencia. Aunque estas relaciones no son generales, se han obtenido muy buenos resultados, ejemplo de ello es el modelo basado en la temperatura, Maturity Method, que forma parte de la norma de la ASTM C 1074 y en el mercado hay disponibles equipos comerciales (maturity meters) para medir el curado del hormigón. Además, es posible diseñar sistemas de medida de estos dos parámetros económicos y robustos; por lo cual es viable la realización de una metodología para el control de calidad del curado que pueda ser implantado en las plantas de producción de prefabricado. En este trabajo se ha desarrollado una metodología que permite estimar la resistencia a la compresión del hormigón durante el curado, la cual consta de un procedimiento para el control de calidad del prefabricado y un sistema inalámbrico de sensores para la medida de la temperatura y la velocidad ultrasónica. El procedimiento para el control de calidad permite realizar una predicción de la resistencia a compresión a partir de un modelo basado en la temperatura de curado y otros dos basados en la velocidad, método de tiempo equivalente y método lineal. El sistema inalámbrico de sensores desarrollado, WilTempUS, integra en el mismo dispositivo sensores de temperatura, humedad relativa y ultrasonidos. La validación experimental se ha realizado mediante monitorizaciones en probetas y en las líneas de prefabricados. Los resultados obtenidos con los modelos de estimación y el sistema de medida desarrollado muestran que es posible predecir la resistencia en prefabricados de hormigón en planta con errores comparables a los aceptables por norma en los ensayos de resistencia a compresión en probetas. ABSTRACT Precast concrete quality is determined by compression tests breakage on specimens after 28 days of curing, as established EHE-08. However, in the precast plants is also necessary to know when the concrete is ready to be processed (slack, cut, moved), so it is necessary to test the compressive strength between 48 and 72 hours. This time is determined from prior experience and depends on the conditions of each plant. If the samples have not reached the set value, usually due to changes in the weather conditions or in the materials used as for example the type of cement or aggregates, the solution usually adopted is to cure the material on track during more time to reach the required strength for processing. If the material still does not reach this strength, which happens very occasionally, the reason of this behavior is analyzed , being able to throw the entire production of that day if there was a failure in the manufacturing line, not a failure of the specimen. Therefore, this method of quality control, using destructive techniques, involves two kinds of problems, costs and representativeness. The most used non-destructive methods to characterize the curing process of concrete are those based on ultrasonic and temperature measurement as stated in the literature. There are different models to establish a relationship between temperature and the curing time to estimate the compressive strength of the material, and between the ultrasonic propagation velocity and the compressive strength. Although these relationships are not general, they have been very successful, for example the Maturity Method is based on the temperature measurements. This method is part of the standards established in ASTM C 1074 and there are commercial equipments available (maturity meters) in the market to measure the concrete curing. Furthermore, it is possible to design inexpensive and robust systems to measure ultrasounds and temperature. Therefore is feasible to determine a method for quality control of curing to be implanted in the precast production plants. In this work, it has been developed a methodology which allows to estimate the compressive strength of concrete during its curing process. This methodology consists of a procedure for quality control of the precast concrete and a wireless sensor network to measure the temperature and ultrasonic velocity. The procedure for quality control allows to predict the compressive strength using a model based on the curing temperature and two other models based on ultrasonic velocity, the equivalent time method and the lineal one. The wireless sensor network, WilTempUS, integrates is the same device temperature, relative humidity and ultrasonic sensors. The experimental validation has been carried out in cubic specimens and in the production plants. The results obtained with the estimation models and the measurement system developed in this thesis show that it is possible to predict the strength in precast concrete plants with errors within the limits of the standards for testing compressive strength specimens.

RDSZ: an approach for lossless RDF stream compression

In many applications (like social or sensor networks) the in- formation generated can be represented as a continuous stream of RDF items, where each item describes an application event (social network post, sensor measurement, etc). In this paper we focus on compressing RDF streams. In particular, we propose an approach for lossless RDF stream compression, named RDSZ (RDF Differential Stream compressor based on Zlib). This approach takes advantage of the structural similarities among items in a stream by combining a differential item encoding mechanism with the general purpose stream compressor Zlib. Empirical evaluation using several RDF stream datasets shows that this combi- nation produces gains in compression ratios with respect to using Zlib alone.

Resource allocation in GMD and SVD-based MIMO System

Singular-value decomposition (SVD)-based multiple-input multiple output (MIMO) systems, where the whole MIMO channel is decomposed into a number of unequally weighted single-input single-output (SISO) channels, have attracted a lot of attention in the wireless community. The unequal weighting of the SISO channels has led to intensive research on bit- and power allocation even in MIMO channel situation with poor scattering conditions identified as the antennas correlation effect. In this situation, the unequal weighting of the SISO channels becomes even much stronger. In comparison to the SVD-assisted MIMO transmission, geometric mean decomposition (GMD)-based MIMO systems are able to compensate the drawback of weighted SISO channels when using SVD, where the decomposition result is nearly independent of the antennas correlation effect. The remaining interferences after the GMD-based signal processing can be easily removed by using dirty paper precoding as demonstrated in this work. Our results show that GMD-based MIMO transmission has the potential to significantly simplify the bit and power loading processes and outperforms the SVD-based MIMO transmission as long as the same QAM-constellation size is used on all equally-weighted SISO channels.

A Dynamically Adaptable Image Processing Application Trading Off Between High Performance, Consumption and Dependability in Real Time

As embedded systems evolve, problems inherent to technology become important limitations. In less than ten years, chips will exceed the maximum allowed power consumption affecting performance, since, even though the resources available per chip are increasing, frequency of operation has stalled. Besides, as the level of integration is increased, it is difficult to keep defect density under control, so new fault tolerant techniques are required. In this demo work, a new dynamically adaptable virtual architecture (ARTICo3) to allow dynamic and context-aware use of resources is implemented in a high performance Wireless Sensor node (HiReCookie) to perform an image processing application.

Power-Aware Multi-Objective Evolvable Hardware System on an FPGA

Dynamic and Partial Reconfiguration (DPR) allows a system to be able to modify certain parts of itself during run-time. This feature gives rise to the capability of evolution: changing parts of the configuration according to the online evaluation of performance or other parameters. The evolution is achieved through a bio-inspired model in which the features of the system are identified as genes. The objective of the evolution may not be a single one; in this work, power consumption is taken into consideration, together with the quality of filtering, as the measure of performance, of a noisy image. Pareto optimality is applied to the evolutionary process, in order to find a representative set of optimal solutions as for performance and power consumption. The main contributions of this paper are: implementing an evolvable system on a low-power Spartan-6 FPGA included in a Wireless Sensor Network node and, by enabling the availability of a real measure of power consumption at run-time, achieving the capability of multi-objective evolution, that yields different optimal configurations, among which the selected one will depend on the relative “weights” of performance and power consumption.

Eventual election of multiple leaders for solving consensus in anonymous systems

In classical distributed systems, each process has a unique identity. Today, new distributed systems have emerged where a unique identity is not always possible to be assigned to each process. For example, in many sensor networks a unique identity is not possible to be included in each device due to its small storage capacity, reduced computational power, or the huge number of devices to be identified. In these cases, we have to work with anonymous distributed systems where processes cannot be identified. Consensus cannot be solved in classical and anonymous asynchronous distributed systems where processes can crash. To bypass this impossibility result, failure detectors are added to these systems. It is known that ? is the weakest failure detector class for solving consensus in classical asynchronous systems when amajority of processes never crashes. Although A? was introduced as an anonymous version of ?, to find the weakest failure detector in anonymous systems to solve consensus when amajority of processes never crashes is nowadays an open question. Furthermore, A? has the important drawback that it is not implementable. Very recently, A? has been introduced as a counterpart of ? for anonymous systems. In this paper, we show that the A? failure detector class is strictly weaker than A? (i.e., A? provides less information about process crashes than A?). We also present in this paper the first implementation of A? (hence, we also show that A? is implementable), and, finally, we include the first implementation of consensus in anonymous asynchronous systems augmented with A? and where a majority of processes does not crash.

Herramienta Web para el modelado de consultas CEP (Complex Event Processing)

RESUMEN En los últimos años, debido al incremento en la demanda por parte de las empresas de tecnologías que posibiliten la monitorización y el análisis de un gran volumen de datos en tiempo real, la tecnología CEP (Complex Event Processing) ha surgido como una potencia en alza y su uso se ha incrementado notablemente en ciertos sectores como, por ejemplo, la gestión y automatización de procesos de negocios, finanzas, monitorización de redes y aplicaciones, así como redes de sensores inteligentes como el caso de estudio en el que nos centraremos. CEP se basa en un lenguaje de procesamiento de eventos (Event Processing Language,EPL) cuya utilización puede resultar bastante compleja para usuarios inexpertos. Esta complejidad supone un hándicap y, por lo tanto, un problema a la hora de que su uso se extienda. Este Proyecto Fin de Grado (PFG) pretende dar una solución a este problema, acercando al usuario la tecnología CEP mediante técnicas de abstracción y modelado. Para ello, este PFG ha definido un lenguaje de modelado específico dominio, sencillo e intuitivo para el usuario inexperto, al que se ha dado soporte mediante el desarrollo de una herramienta de modelado gráfico (CEP Modeler) en la que se pueden modelar consultas CEP de forma gráfica, sencilla y de manera más accesible para el usuario. ABSTRACT Over recent years, more and more companies demand technology for monitoring and analyzing a vast volume of data in real time. In this regard, the CEP technology (Complex Event Processing) has emerged as a novel approach to that end, and its use has increased dramatically in certain domains, such as, management and automation of business processes, finance, monitoring of networks and applications, as well as smart sensor networks as the case study in which we will focus. CEP is based on in the Event Processing Language (EPL). This language can be rather difficult to use for new users. This complexity can be a handicap, and therefore, a problem at the time of extending its use. This project aims to provide a solution to this problem, trying to approach the CEP technology to users through abstraction and modelling techniques. To that end, this project has defined an intuitive and simple domain-specific modelling language for new users through a web tool (CEP Modeler) for graphically modeling CEP queries, in an easier and more accessible way.