Arquitetura multiprocessada e reconfigurável para a síntese de redes de Petri em hardware

Uma arquitetura reconfigurável e multiprocessada para a implementação física de Redes de Petri foi desenvolvida em VHDL e mapeada sobre um FPGA. Convencionalmente, as Redes de Petri são transformadas em uma linguagem de descrição de hardware no nível de transferências entre registradores e um processo de síntese de alto nível é utilizado para gerar as funções booleanas e tabelas de transição de estado para que se possa, finalmente, mapeá-las num FPGA (Morris et al., 2000) (Soto and Pereira, 2001). A arquitetura proposta possui blocos lógicos reconfiguráveis desenvolvidos exclusivamente para a implementação dos lugares e das transições da rede, não sendo necessária a descrição da rede em níveis de abstração intermediários e nem a utilização de um processo de síntese para realizar o mapeamento da rede na arquitetura. A arquitetura permite o mapeamento de modelos de Redes de Petri com diferenciação entre as marcas e associação de tempo no disparo das transições, sendo composta por um arranjo de processadores reconfiguráveis, cada um dos quais representando o comportamento de uma transição da Rede de Petri a ser mapeada e por um sistema de comunicação, implementado por um conjunto de roteadores que são capazes de enviar pacotes de dados de um processador reconfigurável a outro. A arquitetura proposta foi validada num FPGA de 10.570 elementos lógicos com uma topologia que permitiu a implementação de Redes de Petri de até 9 transições e 36 lugares, atingindo uma latência de 15,4ns e uma vazão de até 17,12GB/s com uma freqüência de operação de 64,58MHz.

Desenvolvimento de uma arquitetura multiprocessada e reconfigurável para a síntese de redes de Petri em hardware

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

IPSFlow: Um framework para Sistema de Prevenção de Intrusão baseado em Redes Definidas por Software

Os Sistemas de Detecção e Prevenção de Intrusão (Intrusion Detection Systems – IDS e Intrusion Prevention Systems - IPS) são ferramentas bastante conhecidas e bem consagradas no mundo da segurança da informação. Porém, a falta de integração com os equipamentos de rede como switches e roteadores acaba limitando a atuação destas ferramentas e exige um bom dimensionamento de recursos de hardware como processamento, memória e interfaces de rede de alta velocidade, utilizados para implementá-las. Diante de diversas limitações deparadas por pesquisadores e administradores de redes, surgiu o conceito de Rede Definida por Software (Software Defined Network – SDN), que ao separar os planos de controle e de dados, permite adaptar o funcionamento da rede de acordo com as necessidades de cada um. Desta forma, devido à padronização e flexibilidade propostas pelas SDNs, e das limitações apresentadas dos IPSs, esta dissertação de mestrado propõe o IPSFlow, um framework que utiliza uma rede baseada na arquitetura SDN e o protocolo OpenFlow para a criação de um IPS com ampla cobertura e que permite bloquear um tráfego caracterizado pelos IDS(s) como malicioso no equipamento mais próximo da origem. Para validar o framework, experimentos no ambiente virtual Mininet foram realizados utilizando-se o Snort como IDS para analisar tráfego de varredura (scan) gerado pelo Nmap de um host ao outro. Os resultados coletados apresentam que o IPSFlow funcionou conforme planejado ao efetuar o bloqueio de 85% do tráfego de varredura.

Fresamento de Eucalyptus grandis

The process of milling wood is widely used in operations such as planing and manufacturing frames . Machines like planers , desengrossadeiras , routers , moldureiras and machining centers employ the milling process for cutting wood . In this work the process of milling CNC machining center of Eucalyptus grandis was studied because this is very much used in furniture , but without consistent studies on this process . This work a CNC machining center brand TECH Z1 for analysis of surface quality ( Ra ) in relation to the variation of cutting speed and feed in concordant and discordant tangential milling and face milling was used . We used Eucalyptus grandis . Four forward speeds ( 3, 5 , 7, and 9 m / min ) for four shear rates ( 5,9; 8,4; 10,9 and 13,4 m/s ) were used. Was used for testing a cutter finishing top speed steel with helical teeth 16mm in diameter . 6 repetitions for each test condition were performed . From the results it was observed that the best results for roughness Vc = 10,9 m / s were obtained for the milling concordant with the forward speed Vf = 7 m / min. As for Vf = 5 m / min the best finish was achieved with Vc = 8,4 m /s in discordant for milling . The feedrate and cutting influenced the roughness . The senses of concordant and discordant and cut the top and the top had a significant difference in roughness

Router and Firewall Redundancy with OpenBSD and CARP

As more reliance is placed on computing and networking systems, the need for redundancy increases. The Common Address Redundancy Protocol (CARP) protocol and OpenBSD’s pfsync utility provide a means by which to implement redundant routers and firewalls. This paper details how CARP and pfsync work together to provide this redundancy and explores the performance one can expect from the open source solutions. Two experiments were run: one showing the relationship between firewall state creation and state synchronization traffic and the other showing how TCP sessions are transparently maintained in the event of a router failure. Discussion of these simulations along with background information gives an overview of how OpenBSD, CARP, and pfsync can provide redundant routers and firewalls for today’s Internet.

Cooperative communication and distributed detection in wireless sensor networks

Recent progress in microelectronic and wireless communications have enabled the development of low cost, low power, multifunctional sensors, which has allowed the birth of new type of networks named wireless sensor networks (WSNs). The main features of such networks are: the nodes can be positioned randomly over a given field with a high density; each node operates both like sensor (for collection of environmental data) as well as transceiver (for transmission of information to the data retrieval); the nodes have limited energy resources. The use of wireless communications and the small size of nodes, make this type of networks suitable for a large number of applications. For example, sensor nodes can be used to monitor a high risk region, as near a volcano; in a hospital they could be used to monitor physical conditions of patients. For each of these possible application scenarios, it is necessary to guarantee a trade-off between energy consumptions and communication reliability. The thesis investigates the use of WSNs in two possible scenarios and for each of them suggests a solution that permits to solve relating problems considering the trade-off introduced. The first scenario considers a network with a high number of nodes deployed in a given geographical area without detailed planning that have to transmit data toward a coordinator node, named sink, that we assume to be located onboard an unmanned aerial vehicle (UAV). This is a practical example of reachback communication, characterized by the high density of nodes that have to transmit data reliably and efficiently towards a far receiver. It is considered that each node transmits a common shared message directly to the receiver onboard the UAV whenever it receives a broadcast message (triggered for example by the vehicle). We assume that the communication channels between the local nodes and the receiver are subject to fading and noise. The receiver onboard the UAV must be able to fuse the weak and noisy signals in a coherent way to receive the data reliably. It is proposed a cooperative diversity concept as an effective solution to the reachback problem. In particular, it is considered a spread spectrum (SS) transmission scheme in conjunction with a fusion center that can exploit cooperative diversity, without requiring stringent synchronization between nodes. The idea consists of simultaneous transmission of the common message among the nodes and a Rake reception at the fusion center. The proposed solution is mainly motivated by two goals: the necessity to have simple nodes (to this aim we move the computational complexity to the receiver onboard the UAV), and the importance to guarantee high levels of energy efficiency of the network, thus increasing the network lifetime. The proposed scheme is analyzed in order to better understand the effectiveness of the approach presented. The performance metrics considered are both the theoretical limit on the maximum amount of data that can be collected by the receiver, as well as the error probability with a given modulation scheme. Since we deal with a WSN, both of these performance are evaluated taking into consideration the energy efficiency of the network. The second scenario considers the use of a chain network for the detection of fires by using nodes that have a double function of sensors and routers. The first one is relative to the monitoring of a temperature parameter that allows to take a local binary decision of target (fire) absent/present. The second one considers that each node receives a decision made by the previous node of the chain, compares this with that deriving by the observation of the phenomenon, and transmits the final result to the next node. The chain ends at the sink node that transmits the received decision to the user. In this network the goals are to limit throughput in each sensor-to-sensor link and minimize probability of error at the last stage of the chain. This is a typical scenario of distributed detection. To obtain good performance it is necessary to define some fusion rules for each node to summarize local observations and decisions of the previous nodes, to get a final decision that it is transmitted to the next node. WSNs have been studied also under a practical point of view, describing both the main characteristics of IEEE802:15:4 standard and two commercial WSN platforms. By using a commercial WSN platform it is realized an agricultural application that has been tested in a six months on-field experimentation.

Design and Performance Evaluation of Network-on-Chip Communication Protocols and Architectures

The scale down of transistor technology allows microelectronics manufacturers such as Intel and IBM to build always more sophisticated systems on a single microchip. The classical interconnection solutions based on shared buses or direct connections between the modules of the chip are becoming obsolete as they struggle to sustain the increasing tight bandwidth and latency constraints that these systems demand. The most promising solution for the future chip interconnects are the Networks on Chip (NoC). NoCs are network composed by routers and channels used to inter- connect the different components installed on the single microchip. Examples of advanced processors based on NoC interconnects are the IBM Cell processor, composed by eight CPUs that is installed on the Sony Playstation III and the Intel Teraflops pro ject composed by 80 independent (simple) microprocessors. On chip integration is becoming popular not only in the Chip Multi Processor (CMP) research area but also in the wider and more heterogeneous world of Systems on Chip (SoC). SoC comprehend all the electronic devices that surround us such as cell-phones, smart-phones, house embedded systems, automotive systems, set-top boxes etc... SoC manufacturers such as ST Microelectronics , Samsung, Philips and also Universities such as Bologna University, M.I.T., Berkeley and more are all proposing proprietary frameworks based on NoC interconnects. These frameworks help engineers in the switch of design methodology and speed up the development of new NoC-based systems on chip. In this Thesis we propose an introduction of CMP and SoC interconnection networks. Then focusing on SoC systems we propose: • a detailed analysis based on simulation of the Spidergon NoC, a ST Microelectronics solution for SoC interconnects. The Spidergon NoC differs from many classical solutions inherited from the parallel computing world. Here we propose a detailed analysis of this NoC topology and routing algorithms. Furthermore we propose aEqualized a new routing algorithm designed to optimize the use of the resources of the network while also increasing its performance; • a methodology flow based on modified publicly available tools that combined can be used to design, model and analyze any kind of System on Chip; • a detailed analysis of a ST Microelectronics-proprietary transport-level protocol that the author of this Thesis helped developing; • a simulation-based comprehensive comparison of different network interface designs proposed by the author and the researchers at AST lab, in order to integrate shared-memory and message-passing based components on a single System on Chip; • a powerful and flexible solution to address the time closure exception issue in the design of synchronous Networks on Chip. Our solution is based on relay stations repeaters and allows to reduce the power and area demands of NoC interconnects while also reducing its buffer needs; • a solution to simplify the design of the NoC by also increasing their performance and reducing their power and area consumption. We propose to replace complex and slow virtual channel-based routers with multiple and flexible small Multi Plane ones. This solution allows us to reduce the area and power dissipation of any NoC while also increasing its performance especially when the resources are reduced. This Thesis has been written in collaboration with the Advanced System Technology laboratory in Grenoble France, and the Computer Science Department at Columbia University in the city of New York.

Enhancing quality of service in software-defined networks

Resource management is of paramount importance in network scenarios and it is a long-standing and still open issue. Unfortunately, while technology and innovation continue to evolve, our network infrastructure system has been maintained almost in the same shape for decades and this phenomenon is known as “Internet ossification”. Software-Defined Networking (SDN) is an emerging paradigm in computer networking that allows a logically centralized software program to control the behavior of an entire network. This is done by decoupling the network control logic from the underlying physical routers and switches that forward traffic to the selected destination. One mechanism that allows the control plane to communicate with the data plane is OpenFlow. The network operators could write high-level control programs that specify the behavior of an entire network. Moreover, the centralized control makes it possible to define more specific and complex tasks that could involve many network functionalities, e.g., security, resource management and control, into a single framework. Nowadays, the explosive growth of real time applications that require stringent Quality of Service (QoS) guarantees, brings the network programmers to design network protocols that deliver certain performance guarantees. This thesis exploits the use of SDN in conjunction with OpenFlow to manage differentiating network services with an high QoS. Initially, we define a QoS Management and Orchestration architecture that allows us to manage the network in a modular way. Then, we provide a seamless integration between the architecture and the standard SDN paradigm following the separation between the control and data planes. This work is a first step towards the deployment of our proposal in the University of California, Los Angeles (UCLA) campus network with differentiating services and stringent QoS requirements. We also plan to exploit our solution to manage the handoff between different network technologies, e.g., Wi-Fi and WiMAX. Indeed, the model can be run with different parameters, depending on the communication protocol and can provide optimal results to be implemented on the campus network.

Information-centric communication in mobile and wireless networks

Information-centric networking (ICN) is a new communication paradigm that has been proposed to cope with drawbacks of host-based communication protocols, namely scalability and security. In this thesis, we base our work on Named Data Networking (NDN), which is a popular ICN architecture, and investigate NDN in the context of wireless and mobile ad hoc networks. In a first part, we focus on NDN efficiency (and potential improvements) in wireless environments by investigating NDN in wireless one-hop communication, i.e., without any routing protocols. A basic requirement to initiate informationcentric communication is the knowledge of existing and available content names. Therefore, we develop three opportunistic content discovery algorithms and evaluate them in diverse scenarios for different node densities and content distributions. After content names are known, requesters can retrieve content opportunistically from any neighbor node that provides the content. However, in case of short contact times to content sources, content retrieval may be disrupted. Therefore, we develop a requester application that keeps meta information of disrupted content retrievals and enables resume operations when a new content source has been found. Besides message efficiency, we also evaluate power consumption of information-centric broadcast and unicast communication. Based on our findings, we develop two mechanisms to increase efficiency of information-centric wireless one-hop communication. The first approach called Dynamic Unicast (DU) avoids broadcast communication whenever possible since broadcast transmissions result in more duplicate Data transmissions, lower data rates and higher energy consumption on mobile nodes, which are not interested in overheard Data, compared to unicast communication. Hence, DU uses broadcast communication only until a content source has been found and then retrieves content directly via unicast from the same source. The second approach called RC-NDN targets efficiency of wireless broadcast communication by reducing the number of duplicate Data transmissions. In particular, RC-NDN is a Data encoding scheme for content sources that increases diversity in wireless broadcast transmissions such that multiple concurrent requesters can profit from each others’ (overheard) message transmissions. If requesters and content sources are not in one-hop distance to each other, requests need to be forwarded via multi-hop routing. Therefore, in a second part of this thesis, we investigate information-centric wireless multi-hop communication. First, we consider multi-hop broadcast communication in the context of rather static community networks. We introduce the concept of preferred forwarders, which relay Interest messages slightly faster than non-preferred forwarders to reduce redundant duplicate message transmissions. While this approach works well in static networks, the performance may degrade in mobile networks if preferred forwarders may regularly move away. Thus, to enable routing in mobile ad hoc networks, we extend DU for multi-hop communication. Compared to one-hop communication, multi-hop DU requires efficient path update mechanisms (since multi-hop paths may expire quickly) and new forwarding strategies to maintain NDN benefits (request aggregation and caching) such that only a few messages need to be transmitted over the entire end-to-end path even in case of multiple concurrent requesters. To perform quick retransmission in case of collisions or other transmission errors, we implement and evaluate retransmission timers from related work and compare them to CCNTimer, which is a new algorithm that enables shorter content retrieval times in information-centric wireless multi-hop communication. Yet, in case of intermittent connectivity between requesters and content sources, multi-hop routing protocols may not work because they require continuous end-to-end paths. Therefore, we present agent-based content retrieval (ACR) for delay-tolerant networks. In ACR, requester nodes can delegate content retrieval to mobile agent nodes, which move closer to content sources, can retrieve content and return it to requesters. Thus, ACR exploits the mobility of agent nodes to retrieve content from remote locations. To enable delay-tolerant communication via agents, retrieved content needs to be stored persistently such that requesters can verify its authenticity via original publisher signatures. To achieve this, we develop a persistent caching concept that maintains received popular content in repositories and deletes unpopular content if free space is required. Since our persistent caching concept can complement regular short-term caching in the content store, it can also be used for network caching to store popular delay-tolerant content at edge routers (to reduce network traffic and improve network performance) while real-time traffic can still be maintained and served from the content store.

B-Neck: A Distributed and Quiescent Max-Min Fair Algorithm

The problem of fairly distributing the capacity of a network among a set of sessions has been widely studied. In this problem, each session connects via a single path a source and a destination, and its goal is to maximize its assigned transmission rate (i.e., its throughput). Since the links of the network have limited bandwidths, some criterion has to be defined to fairly distribute their capacity among the sessions. A popular criterion is max-min fairness that, in short, guarantees that each session i gets a rate λi such that no session s can increase λs without causing another session s' to end up with a rate λs/ <; λs. Many max-min fair algorithms have been proposed, both centralized and distributed. However, to our knowledge, all proposed distributed algorithms require control data being continuously transmitted to recompute the max-min fair rates when needed (because none of them has mechanisms to detect convergence to the max-min fair rates). In this paper we propose B-Neck, a distributed max-min fair algorithm that is also quiescent. This means that, in absence of changes (i.e., session arrivals or departures), once the max min rates have been computed, B-Neck stops generating network traffic. Quiescence is a key design concept of B-Neck, because B-Neck routers are capable of detecting and notifying changes in the convergence conditions of max-min fair rates. As far as we know, B-Neck is the first distributed max-min fair algorithm that does not require a continuous injection of control traffic to compute the rates. The correctness of B-Neck is formally proved, and extensive simulations are conducted. In them, it is shown that B-Neck converges relatively fast and behaves nicely in presence of sessions arriving and departing.

A big data platform for large scale event processing

To date, big data applications have focused on the store-and-process paradigm. In this paper we describe an initiative to deal with big data applications for continuous streams of events. In many emerging applications, the volume of data being streamed is so large that the traditional ‘store-then-process’ paradigm is either not suitable or too inefficient. Moreover, soft-real time requirements might severely limit the engineering solutions. Many scenarios fit this description. In network security for cloud data centres, for instance, very high volumes of IP packets and events from sensors at firewalls, network switches and routers and servers need to be analyzed and should detect attacks in minimal time, in order to limit the effect of the malicious activity over the IT infrastructure. Similarly, in the fraud department of a credit card company, payment requests should be processed online and need to be processed as quickly as possible in order to provide meaningful results in real-time. An ideal system would detect fraud during the authorization process that lasts hundreds of milliseconds and deny the payment authorization, minimizing the damage to the user and the credit card company.

Redes y servicios ubicuos para Internet de las Cosas en dispositivos llevables

En las últimas décadas se han producido importantes avances tecnológicos, lo que ha producido un crecimiento importante de las Redes Inalámbricas de Sensores (RIS), conocidas en inglés como Wireless Sensor Networks (WSN). Estas redes están formadas por un conjunto de pequeños nodos o también, conocidos como motas, compuestos por diversos tipos de sensores. Las Redes Inalámbricas de Sensores pueden resultar muy útiles en entornos donde el despliegue de redes cableadas, formadas por ordenadores, encaminadores u otros dispositivos de red no sea posible. Sin embargo, este tipo de redes presentan una serie de carencias o problemas que dificultan, en ocasiones, su implementación y despliegue. Este Proyecto Fin de Carrera tiene como principales objetivos: diseñar e implementar un agente que haga uso de la tecnología Bluetooth para que se pueda comunicar tanto con la arquitectura orientada a servicios, vía radio, como con el módulo Bioharness para obtener parámetros fisiológicos; ofrecer una serie de servicios simples a la Red Inalámbrica de Sensores; diseñar un algoritmo para un sistema de alarmas; realizar e implementar una pasarela entre protocolos que usen el estándar IEEE802.15.4 (ZigBee) y el estándar IEEE802.15.1 de la Tecnología Bluetooth. Por último, implementar una aplicación Android para el reloj WiMM y que este pueda recibir alarmas en tiempo real a través del la Interfaz Bluetooth. Para lograr estos objetivos, en primer lugar realizaremos un estudio del Estado del Arte de las Redes Inalámbricas de Sensores, con el fin de estudiar su arquitectura, el estándar Bluetooth y los dispositivos Bluetooth que se han utilizado en este Proyecto. Seguidamente, describiremos detalladamente el firmware iWRAP versión 4, centrándonos en sus modos de operación, comandos AT y posibles errores que puedan ocurrir. A continuación, se describirá la arquitectura y la especificación nSOM, para adentrarnos en la arquitectura orientada a servicios. Por último, ejecutaremos la fase de validación del sistema y se analizarán los resultados obtenidos durante la fase de pruebas. ABSTRACT In last decades there have been significant advances in technology, which has resulted in important growth of Wireless Sensor Networks (WSN). These networks consist of a small set of nodes, also known as spots; equipped with various types of sensors. Wireless Sensor Networks can be very useful in environments where deployment of wired networks, formed by computers, routers or other network devices is not possible. However, these networks have a number of shortcomings or challenges to, sometimes, their implementation and deployment. The main objectives of this Final Project are to design and implement an agent that makes use of Bluetooth technology so you can communicate with both the service-oriented architecture, via radio, as with Bioharness module for physiological parameters; offer simple services to Wireless Sensor Network, designing an algorithm for an alarm system, make and implement a gateway between protocols using the standard IEEE802.15.4 (ZigBee) and IEEE802.15.1 standard Bluetooth Technology. Finally, implement an Android application for WiMM watch that can receive real-time alerts through the Bluetooth interface. In order to achieve these objectives, firstly we are going to carry out a study of the State of the Art in Wireless Sensor Network, where we study the architecture, the Bluetooth standard and Bluetooth devices that have been used in this project. Then, we will describe in detail the iWRAP firmware version 4, focusing on their operation modes, AT commands and errors that may occur. Therefore, we will describe the architecture and specification nSOM, to enter into the service-oriented architecture. Finally, we will execute the phase of validation of the system in a real application scenario, analyzing the results obtained during the testing phase.

SLBN: A Scalable Max-min Fair Algorithm for Rate-Based Explicit Congestion Control

The growth of the Internet has increased the need for scalable congestion control mechanisms in high speed networks. In this context, we propose a rate-based explicit congestion control mechanism with which the sources are provided with the rate at which they can transmit. These rates are computed with a distributed max-min fair algorithm, SLBN. The novelty of SLBN is that it combines two interesting features not simultaneously present in existing proposals: scalability and fast convergence to the max-min fair rates, even under high session churn. SLBN is scalable because routers only maintain a constant amount of state information (only three integer variables per link) and only incur a constant amount of computation per protocol packet, independently of the number of sessions that cross the router. Additionally, SLBN does not require processing any data packet, and it converges independently of sessions' RTT. Finally, by design, the protocol is conservative when assigning rates, even in the presence of high churn, which helps preventing link overshoots in transient periods. We claim that, with all these features, our mechanism is a good candidate to be used in real deployments.

A framework for building distributed social network websites

Las redes son la esencia de comunidades y sociedades humanas; constituyen el entramado en el que nos relacionamos y determinan cómo lo hacemos, cómo se disemina la información o incluso cómo las cosas se llevan a cabo. Pero el protagonismo de las redes va más allá del que adquiere en las redes sociales. Se encuentran en el seno de múltiples estructuras que conocemos, desde las interaciones entre las proteínas dentro de una célula hasta la interconexión de los routers de internet. Las redes sociales están presentes en internet desde sus principios, en el correo electrónico por tomar un ejemplo. Dentro de cada cliente de correo se manejan listas contactos que agregadas constituyen una red social. Sin embargo, ha sido con la aparición de los sitios web de redes sociales cuando este tipo de aplicaciones web han llegado a la conciencia general. Las redes sociales se han situado entre los sitios más populares y con más tráfico de la web. Páginas como Facebook o Twitter manejan cifras asombrosas en cuanto a número de usuarios activos, de tráfico o de tiempo invertido en el sitio. Pero las funcionalidades de red social no están restringidas a las redes sociales orientadas a contactos, aquellas enfocadas a construir tu lista de contactos e interactuar con ellos. Existen otros ejemplos de sitios que aprovechan las redes sociales para aumentar la actividad de los usuarios y su involucración alrededor de algún tipo de contenido. Estos ejemplos van desde una de las redes sociales más antiguas, Flickr, orientada al intercambio de fotografías, hasta Github, la red social de código libre más popular hoy en día. No es una casualidad que la popularidad de estos sitios web venga de la mano de sus funcionalidades de red social. El escenario es más rico aún, ya que los sitios de redes sociales interaccionan entre ellos, compartiendo y exportando listas de contactos, servicios de autenticación y proporcionando un valioso canal para publicitar la actividad de los usuarios en otros sitios web. Esta funcionalidad es reciente y aún les queda un paso hasta que las redes sociales superen su condición de bunkers y lleguen a un estado de verdadera interoperabilidad entre ellas, tal como funcionan hoy en día el correo electrónico o la mensajería instantánea. Este trabajo muestra una tecnología que permite construir sitios web con características de red social distribuída. En primer lugar, se presenta una tecnología para la construcción de un componente intermedio que permite proporcionar cualquier característica de gestión de contenidos al popular marco de desarrollo web modelo-vista-controlador (MVC) Ruby on Rails. Esta técnica constituye una herramienta para desarrolladores que les permita abstraerse de las complejidades de la gestión de contenidos y enfocarse en las particularidades de los propios contenidos. Esta técnica se usará también para proporcionar las características de red social. Se describe una nueva métrica de reusabilidad de código para demostrar la validez del componente intermedio en marcos MVC. En segundo lugar, se analizan las características de los sitios web de redes sociales más populares, con el objetivo de encontrar los patrones comunes que aparecen en ellos. Este análisis servirá como base para definir los requisitos que debe cumplir un marco para construir redes sociales. A continuación se propone una arquitectura de referencia que proporcione este tipo de características. Dicha arquitectura ha sido implementada en un componente, Social Stream, y probada en varias redes sociales, tanto orientadas a contactos como a contenido, en el contexto de una asociación vecinal tanto como en proyectos de investigación financiados por la UE. Ha sido la base de varios proyectos fin de carrera. Además, ha sido publicado como código libre, obteniendo una comunidad creciente y está siendo usado más allá del ámbito de este trabajo. Dicha arquitectura ha permitido la definición de un nuevo modelo de control de acceso social que supera varias limitaciones presentes en los modelos de control de acceso para redes sociales. Más aún, se han analizado casos de estudio de sitios de red social distribuídos, reuniendo un conjunto de caraterísticas que debe cumplir un marco para construir redes sociales distribuídas. Por último, se ha extendido la arquitectura del marco para dar cabida a las características de redes sociales distribuídas. Su implementación ha sido validada en proyectos de investigación financiados por la UE. Abstract Networks are the substance of human communities and societies; they constitute the structural framework on which we relate to each other and determine the way we do it, the way information is diseminated or even the way people get things done. But network prominence goes beyond the importance it acquires in social networks. Networks are found within numerous known structures, from protein interactions inside a cell to router connections on the internet. Social networks are present on the internet since its beginnings, in emails for example. Inside every email client, there are contact lists that added together constitute a social network. However, it has been with the emergence of social network sites (SNS) when these kinds of web applications have reached general awareness. SNS are now among the most popular sites in the web and with the higher traffic. Sites such as Facebook and Twitter hold astonishing figures of active users, traffic and time invested into the sites. Nevertheless, SNS functionalities are not restricted to contact-oriented social networks, those that are focused on building your own list of contacts and interacting with them. There are other examples of sites that leverage social networking to foster user activity and engagement around other types of content. Examples go from early SNS such as Flickr, the photography related networking site, to Github, the most popular social network repository nowadays. It is not an accident that the popularity of these websites comes hand-in-hand with their social network capabilities The scenario is even richer, due to the fact that SNS interact with each other, sharing and exporting contact lists and authentication as well as providing a valuable channel to publize user activity in other sites. These interactions are very recent and they are still finding their way to the point where SNS overcome their condition of data silos to a stage of full interoperability between sites, in the same way email and instant messaging networks work today. This work introduces a technology that allows to rapidly build any kind of distributed social network website. It first introduces a new technique to create middleware that can provide any kind of content management feature to a popular model-view-controller (MVC) web development framework, Ruby on Rails. It provides developers with tools that allow them to abstract from the complexities related with content management and focus on the development of specific content. This same technique is also used to provide the framework with social network features. Additionally, it describes a new metric of code reuse to assert the validity of the kind of middleware that is emerging in MVC frameworks. Secondly, the characteristics of top popular SNS are analysed in order to find the common patterns shown in them. This analysis is the ground for defining the requirements of a framework for building social network websites. Next, a reference architecture for supporting the features found in the analysis is proposed. This architecture has been implemented in a software component, called Social Stream, and tested in several social networks, both contact- and content-oriented, in local neighbourhood associations and EU-founded research projects. It has also been the ground for several Master’s theses. It has been released as a free and open source software that has obtained a growing community and that is now being used beyond the scope of this work. The social architecture has enabled the definition of a new social-based access control model that overcomes some of the limitations currenly present in access control models for social networks. Furthermore, paradigms and case studies in distributed SNS have been analysed, gathering a set of features for distributed social networking. Finally the architecture of the framework has been extended to support distributed SNS capabilities. Its implementation has also been validated in EU-founded research projects.

Desarrollo de aplicaciones de comunicaciones inalámbricas en sistemas de monitorización estructural desarrollados en aeronáutica.

Los Sistemas de SHM o de monitorización de la integridad estructural surgen ante la necesidad de mejorar los métodos de evaluación y de test no destructivos convencionales. De esta manera, se puede tener controlado todo tipo de estructuras en las cuales su correcto estado o funcionamiento suponga un factor crítico. Un Sistema SHM permite analizar una estructura concreta capturando de manera periódica el estado de la integridad estructural, que en este proyecto se ha aplicado a estructuras aeronáuticas. P.A.M.E.L.A. (Phase Array Monitoring for Enhanced Life Assessment) es la denominación utilizada para definir una serie de equipos electrónicos para Sistemas SHM desarrollados por AERNOVA y los Grupos de Diseño Electrónico de las universidades UPV/EHU y UPM. Los dispositivos P.A.M.E.L.A. originalmente no cuentan con tecnología Wi-Fi, por lo que incorporan un módulo hardware independiente que se encarga de las comunicaciones inalámbricas, a los que se les denomina Nodos. Estos Nodos poseen un Sistema Operativo propio y todo lo necesario para administrar y organizar la red Mallada Wi-Fi. De esta manera se obtiene una red mallada inalámbrica compuesta por Nodos que interconectan los Sistemas SHM y que se encargan de transmitir los datos a los equipos que procesan los resultados adquiridos por P.A.M.E.L.A. Los Nodos son dispositivos empotrados que llevan instalados un firmware basado en una distribución de Linux para Nodos (o Routers), llamado Openwrt. Que para disponer de una red mallada necesitan de un protocolo orientado a este tipo de redes. Entre las opciones de protocolo más destacadas se puede mencionar: DSDV (Destination Sequenced Distance Vector), OLSR (Optimized Link State Routing), B.A.T.M.A.N-Adv (Better Approach To Mobile Adhoc Networking Advance), BMX (una versión de B.A.T.M.A.N-Adv), AODV (Ad hoc On-Demand Distance Vector) y el DSR (Dynamic Source Routing). Además de la existencia de protocolos orientados a las redes malladas, también hay organizaciones que se dedican a desarrollar firmware que los utilizan, como es el caso del firmware llamado Nightwing que utiliza BMX, Freifunk que utiliza OLSR o Potato Mesh que utiliza B.A.T.M.A.N-Adv. La ventaja de estos tres firmwares mencionados es que las agrupaciones que las desarrollan proporcionan las imágenes precompiladas del sistema,listas para cargarlas en distintos modelos de Nodos. En este proyecto se han instalado las imágenes en los Nodos y se han probado los protocolos BMX, OLSR y B.A.T.M.A.N.-Adv. Concluyendo que la red gestionada por B.A.T.M.A.N.-Adv era la que mejor rendimiento obtenía en cuanto a estabilidad y ancho de banda. Después de haber definido el protocolo a usar, se procedió a desarrollar una distribución basada en Openwrt, que utilice B.A.T.M.A.N.-Adv para crear la red mallada, pero que se ajuste mejor a las necesidades del proyecto, ya que Nightwing, Freifunk y Potato Mesh no lo hacían. Además se implementan aplicaciones en lenguaje ANSI C y en LabVIEW para interactuar con los Nodos y los Sistemas SHM. También se procede a hacer alguna modificación en el Hardware de P.A.M.E.L.A. y del Nodo para obtener una mejor integración entre los dos dispositivos. Y por ultimo, se prueba la transferencia de datos de los Nodos en distintos escenarios. ABSTRACT. Structural Health Monitoring (SHM) systems arise from the need of improving assessment methods and conventional nondestructive tests. Critical structures can be monitored using SHM. A SHM system analyzes periodically a specific structure capturing the state of structural integrity. The aim of this project is to contribute in the implementation of Mesh network for SHM system in aircraft structures. P.A.M.E.L.A. (Phase Array Monitoring for Enhanced Life Assessment) is the name for electronic equipment developed by AERNOVA, the Electronic Design Groups of university UPV/EHU and the Instrumentation and Applied Acoustics research group from UPM. P.A.M.E.L.A. devices were not originally equipped with Wi-Fi interface. In this project a separate hardware module that handles wireless communications (nodes) has been added. The nodes include an operating system for manage the Wi-Fi Mesh Network and they form the wireless mesh network to link SHM systems with monitoring equipment. Nodes are embedded devices with an installed firmware based on special Linux distribution used in routers or nodes, called OpenWRT. They need a Mesh Protocol to stablish the network. The most common protocols options are: DSDV (Destination Sequenced Distance Vector), OLSR (Optimized Link State Routing), BATMAN-Adv (Better Approach To Mobile Ad-hoc Networking Advance), BMX (a version of BATMAN-Adv) AODV (Ad hoc on-Demand Distance Vector) and DSR (Dynamic Source Routing). In addition, there are organizations that are dedicated to develope firmware using these Mesh Protocols, for instance: Nightwing uses BMX, Freifunk use OLSR and Potato Mesh uses BATMAN-Adv. The advantage of these three firmwares is that these groups develop pre-compiled images of the system ready to be loaded in several models of Nodes. In this project the images were installed in the nodes. In this way, BMX, OLSR and BATMAN-Adv have been tested. We conclude that the protocol BATMAN-Adv has better performance in terms of stability and bandwidth. After choosing the protocol, the objective was to develop a distribution based on OpenWRT, using BATMAN-Adv to create the mesh network. This distribution is fitted to the requirements of this project. Besides, in this project it has been developed applications in C language and LabVIEW to interact with the Nodes and the SHM systems. The project also address some modifications to the PAMELA hardware and the Node, for better integration between both elements. Finally, data transfer tests among the different nodes in different scenarios has been carried out.