• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 752
  • 158
  • 140
  • 54
  • 49
  • 27
  • 23
  • 22
  • 13
  • 10
  • 9
  • 7
  • 6
  • 5
  • 5
  • Tagged with
  • 1411
  • 1214
  • 377
  • 291
  • 289
  • 265
  • 251
  • 224
  • 212
  • 166
  • 164
  • 144
  • 143
  • 131
  • 126
  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
351

SDN no contexto de IoT : refatoração de middleware para monitoramento de pacientes crônicos baseada em software-defined networking / SDN in the IoT context : software-defined networking based refactoring of a middleware for chronic patients monitoring

Arbiza, Lucas Mendes Ribeiro January 2016 (has links)
Algumas palavras e definições comumente utilizadas quando se está falando de Software-Defined Networking, como programabilidade, flexibilidade, ou gerenciamento centralizado, parecem muito apropriadas ao contexto de um outro paradigma de rede: Internet of Things. Em redes domésticas já não é incomum a existência de dispositivos projetados para segurança, climatização, iluminação, monitoramento de saúde e algumas formas de automação que diferem entre si em diversos aspectos, como no modo de operar e de se comunicar. Lidar com este tipo de cenário, que pode diferir bastante daquilo que estamos acostumados na gerência de redes e serviços, fazendo uso dos recursos tradicionais como ferramentas e protocolos bem estabelecidos, pode ser difícil e, em alguns casos, inviável. Com o objetivo de possibilitar o monitoramento remoto de pacientes com doenças crônicas através de dispositivos de healthcare disponíveis no mercado, uma proposta de middleware foi desenvolvida em um projeto de pesquisa para contornar as limitações relacionadas à interoperabilidade, coleta de dados, gerência, segurança e privacidade encontradas nos dispositivos utilizados. O middleware foi projetado com o intuito de executar em access points instalados na casa dos pacientes. Contudo, as limitações de hardware e software do access point utilizado refletem no desenvolvimento, pois restringem o uso de linguagens de programação e recursos que poderiam agilizar e facilitar a implementação dos módulos e dos mecanismos necessários. Os contratempos encontrados no desenvolvimento motivaram a busca por alternativas, o que resultou na refatoração do middleware através de Software-Defined Networking, baseando-se em trabalhos que exploram o uso desse paradigma em redes domésticas. O objetivo deste trabalho é verificar a viabilidade da utilização de Software-Defined Networking no contexto de Internet of Things, mais especificamente, aplicado ao serviço de monitoramento de pacientes da proposta anterior e explorar os possíveis benefícios resultantes. Com a refatoração, a maior parte da carga de serviços da rede e do monitoramento foi distribuída entre servidores remotos dedicados, com isso os desenvolvedores podem ir além das restrições do access point e fazer uso de recursos antes não disponíveis, o que potencializa um processo de desenvolvimento mais ágil e com funcionalidades mais complexas, ampliando as possibilidades do serviço. Adicionalmente, a utilização de Software-Defined Networking proporcionou a entrega de mais de um serviço através de um único access point, escalabilidade e autonomia no gerenciamento das redes e dos dispositivos e na implantação de serviços, fazendo uso de recursos do protocolo OpenFlow, e a cooperação entre dispositivos e serviços a fim de se criar uma representação digital mais ampla do ambiente monitorado. / Some words and definitions usually employed when talking about Software-Defined Networking such as programmability, frexibility, or centralized management sound very appropriate to the context of another network paradigm: Internet of Things. The presence of devices designed for security, air conditioning, lighting, health monitoring and some other automation resources have become common in home networks; those devices may be different in many ways, such as the way they operate and communicate, between others. Dealing with this kind of scenario may differ in many ways from what we are familiar regarding networking and services management; the use of traditional management tools and protocols may be hard or even unfeasible. Aiming to enable the health monitoring of patients with chronical illnesses through using off-the-shelf healthcare devices a middleware proposal was developed in a research project to circumvent interoperability, data collecting, management, security and privacy issues found in employed devices. The middleware was designed to run on access points in the homes of the patients. Although hardware and software limitations of the used access points reflect on the development process, because they restrict the use of programming languages and resources that could be employed to expedite the implementation of necessary modules and features. Development related mishaps have motivated the search for alternatives resulting in the middleware refactoring through Software-Defined Networking, based on previous works where that paradigm is used in home networks. This work aims to verify the feasability of the employment of Software- Defined Networking in the Internet of Things context, and its resulting benefits; specifically in the health monitoring of chronic patients service from the previous proposal. After refactoring most of the network and services load was distributed among remote dedicated servers allowing developers to go beyond the limitations imposed by access points constraints, and to make use of resources not available before enabling agility to the development process; it also enables the development of more complex features expanding services possibilities. Additionally Software-Defined Networking employment provides benefits such as the delivering of more than only one service through the same access point; scalability and autonomy to the network and devices monitoring, as to the service deployment through the use of OpenFlow resources; and devices and services cooperation enabling the built of a wider digital representation of the monitored environment.
352

Experimental Comparison of Radio Duty Cycling Protocols for Wireless Sensor Networks

Uwase, Marie-Paule 30 October 2018 (has links) (PDF)
Wireless sensor networks are often battery powered and therefore their power consumption is of critical importance. Power requirements can be reduced by switching off radios when they are not needed and by using multi-hop communications to reduce the length of the radio links. Multi-hop communications however require message routing through the network. The Routing Protocol for lossy networks (RPL) has been designed by the Internet Engineering Task Force (IETF) for seamless integration of wireless sensor networks in the Internet. For switching on and off radios, radio duty cycling (RDC) protocols have been added to the traditional medium access control (MAC) protocols. Despite the fact they belong to different layers in the communications stack, it is intuitively clear that the choice of a specific RDC protocol for saving energy can influence the performances of RPL. Exploring experimentally this influence was the initial goal of this research. A 25 nodes wireless sensor network using Zolertia Z1 motes and the Contiki software was used for this investigation. Performance measurements without RDC protocol and with the three different RDC protocols readily available in Contiki were organized and the results of the experiments were compared. Unfortunately, with all three RDC protocols, serious malfunctions obscured the experimental results. Those malfunctions did not show up in absence of a RDC protocol and they could not be reproduced by our simulation studies. To tackle this issue, the behavior of the RDC protocols was scrutinized by means of experimental set-ups that eliminated as much as possible all non RDC related issues. Many, quite varied, malfunctions were discovered which all could have caused the observed RPL issues. Further research and better experimental set-ups made clear that all the discovered RDC malfunctions could be attributed to two real-world facts that were not considered by the implementers of the Contiki RDC protocols. The first cause is the small frequency difference between hardware real time clocks in stand-alone motes. The second is that the threshold built in the receiver to detect radio activity is much higher than the minimum level of signal that the same receiver can decode. Work-arounds have been designed for the observed malfunctions and they have been tested by means of a systematic comparison of the performance of the three modified RDC protocols. / Doctorat en Sciences de l'ingénieur et technologie / info:eu-repo/semantics/nonPublished
353

Negative space of things : a practice-based research approach to understand the role of objects in the Internet of Things

Shingleton, Duncan James January 2018 (has links)
This is a practice-based research thesis situated in the research context of the 'Internet of Things', and critiques contemporary theoretical discourse related to the 21st century turn of connecting everyday objects to the World Wide Web. In the last decade we have seen the 'Internet of Things' articulated predominately through three commercial design fictions, each a response to the shift towards pervasive", "ubiquitous" (Weiser 1991), or "context-ware" (Schilit, 1994) computing; where we inhabit spaces with objects capable of sensing, recording and relaying data about themselves and their environments. Through reflecting upon these existing design fictions, through a new combination of theories and practice-based research that embodies them, this thesis proposes a recovery to understanding the role of objects in the 'Internet of Things', which this author believes has been lost since its conception in the mid 2000s. In 2000, HP Labs presented Cooltown, which addressed what HP identified as the 'convergence of Web technology, wireless networks, and portable client devices provides'. Cooltown's primary discourse was to provide 'new design opportunities for computer/communications systems, through an infrastructure to support "web presence" for people, places and things.' (Anders 1998; Barton & Kindberg 2002). IBM's Smarter Planet followed this in 2008 and shifted importance from the act of connecting objects to understanding the value of data as it flows between these objects in a network (Castells 1996; Sterling 2005; Latour 2005). Finally, Cisco presented The Internet of Everything in 2012 and moved the argument on one stage further, identifying that the importance of connected objects lies in the sum of their communication across silos of networks, where data can provide potential insight from which you can improve services (Bleecker 2006). Despite these design and theoretical fictions, the affordances of the Internet of Things first proposed in the mid 2000s has regressed from data to product, driven largely by unchanged discourse argued by those designers at its conception and also the enticement of being the next Google acquisition; instead of pigeons reporting on the environmental conditions of a city (Da Costa 2006), we have thermostats controllable from your smartphone (www.scottishpower.co.uk/connect). Therefore the aim of this thesis is to re-examine the initial potential of the Internet of Things, which is tested through a series of design interventions as research for art and design, (produced as part of my EPSRC funded doctoral studies on the Tales of Things and Electronic Memory research project and also whilst employed as a research assistant on two EPSRC funded research programmes of work Sixth Sense Transport, and The Connected High Street), to understand how we use data to allow an alternative discourse to emerge in order to recover the role of a networked object, rather than producing prototypical systems.
354

An Approach to QoS-based Task Distribution in Edge Computing Networks for IoT Applications

January 2018 (has links)
abstract: Internet of Things (IoT) is emerging as part of the infrastructures for advancing a large variety of applications involving connections of many intelligent devices, leading to smart communities. Due to the severe limitation of the computing resources of IoT devices, it is common to offload tasks of various applications requiring substantial computing resources to computing systems with sufficient computing resources, such as servers, cloud systems, and/or data centers for processing. However, this offloading method suffers from both high latency and network congestion in the IoT infrastructures. Recently edge computing has emerged to reduce the negative impacts of tasks offloading to remote computing systems. As edge computing is in close proximity to IoT devices, it can reduce the latency of task offloading and reduce network congestion. Yet, edge computing has its drawbacks, such as the limited computing resources of some edge computing devices and the unbalanced loads among these devices. In order to effectively explore the potential of edge computing to support IoT applications, it is necessary to have efficient task management and load balancing in edge computing networks. In this dissertation research, an approach is presented to periodically distributing tasks within the edge computing network while satisfying the quality-of-service (QoS) requirements of tasks. The QoS requirements include task completion deadline and security requirement. The approach aims to maximize the number of tasks that can be accommodated in the edge computing network, with consideration of tasks’ priorities. The goal is achieved through the joint optimization of the computing resource allocation and network bandwidth provisioning. Evaluation results show the improvement of the approach in increasing the number of tasks that can be accommodated in the edge computing network and the efficiency in resource utilization. / Dissertation/Thesis / Doctoral Dissertation Computer Engineering 2018
355

VIPLE Extensions in Robotic Simulation, Quadrotor Control Platform, and Machine Learning for Multirotor Activity Recognition

January 2018 (has links)
abstract: Machine learning tutorials often employ an application and runtime specific solution for a given problem in which users are expected to have a broad understanding of data analysis and software programming. This thesis focuses on designing and implementing a new, hands-on approach to teaching machine learning by streamlining the process of generating Inertial Movement Unit (IMU) data from multirotor flight sessions, training a linear classifier, and applying said classifier to solve Multi-rotor Activity Recognition (MAR) problems in an online lab setting. MAR labs leverage cloud computing and data storage technologies to host a versatile environment capable of logging, orchestrating, and visualizing the solution for an MAR problem through a user interface. MAR labs extends Arizona State University’s Visual IoT/Robotics Programming Language Environment (VIPLE) as a control platform for multi-rotors used in data collection. VIPLE is a platform developed for teaching computational thinking, visual programming, Internet of Things (IoT) and robotics application development. As a part of this education platform, this work also develops a 3D simulator capable of simulating the programmable behaviors of a robot within a maze environment and builds a physical quadrotor for use in MAR lab experiments. / Dissertation/Thesis / Masters Thesis Computer Science 2018
356

Les identités au centre de la mise en oeuvre de comportements dans le cadre de collectifs multi-agents : application au Web des Objets / Towards an Identity-based Cooperation in Coexisting Multiagent Systems

Khalfi, El mehdi 28 November 2018 (has links)
Avec le développement des objets connectés, les agents embarqués déployés dans des environnements physiques et les applications multi-agents qui les impliquent deviennent de plus en plus populaires. Ces systèmes multi-agents sont amenés à partager le même environnement physique. Cette cohabitation d'agents de systèmes différents, qui n'ont pas nécessairement été prévus pour interagir entre eux par les concepteurs, les amène cependant à se solliciter. Un agent peut alors participer à la réalisation d'objectifs incompatibles avec les siens ou ceux de ses collectifs. Pour éviter ces situations, nous proposons un modèle d'agent basé sur les identités pour l'aider à décider de sa participation ou non à des actions collectives. / Embedded agents deployed in physical environments are increasingly interoperable, and are likely to coexist with agents of others systems in a same physical space. So, an agent needs to be able to cooperate with agents from other systems and to form coalitions with unfamiliar teammates. However, before committing to cooperate with others, an agent must take into account that it may get involved in the achievement of objectives that are incompatible with its own, with the global objectives of its system, or with those derived from its previously joined coalitions. To avoid such situations, we propose an identity-based cooperation mechanism. This mechanism involves creating and sustaining the agent identity, and a commitment process to reason about identities when solicited to participate in a collective trans-MAS action.
357

A Flexible FPGA-Assisted Framework for Remote Attestation of Internet Connected Embedded Devices

Patten, Jared Russell 01 March 2018 (has links)
Embedded devices permeate our every day lives. They exist in our vehicles, traffic lights, medical equipment, and infrastructure controls. In many cases, improper functionality of these devices can present a physical danger to their users, data or financial loss, etc. Improper functionality can be a result of software or hardware bugs, but now more than ever, is often the result of malicious compromise and tampering, or as it is known colloquially "hacking". We are beginning to witness a proliferation of cyber-crime, and as more devices are built with internet connectivity (in the so called "Internet of Things"), security should be of the utmost concern. Embedded devices have begun to seamlessly merge with our daily existence. Therefore the need for security grows as it more directly affects the safety of our data, property, and even physical health. This thesis presents an FPGA-assisted framework for remote attestation, a security service that allows a remote device to prove to a verifying entity that it can be trusted. In other words, it presents a protocol by which a device (be it an insulin pump, vehicle, etc.) can prove to a user (or other entity) that it can be trusted - i.e. that it has not been "hacked". This is accomplished through executable code integrity verification and run-time monitoring. In essence, the protocol verifies that a device is running authorized and untampered software and makes it known to a verifier in a trusted fashion. We implement the protocol on a physical device to demonstrate its feasibility and to examine its performance impact.
358

Monsters and Mayhem: Physical and Moral Survival in Stephen King's Universe

Davis, Jaime L. 06 March 2012 (has links)
The goal of my thesis is to analyze physical and moral survival in three novels from King's oeuvre. Scholars have attributed survival in King's universe to factors such as innocence, imaginative capacity, and career choice. Although their arguments are convincing, I believe that physical and moral survival ultimately depends on a character's knowledge of the dark side of human nature and an understanding of moral agency. I have chosen three novels that span several decades of Kings work-'Salem's Lot, Needful Things, and Desperation-to illustrate the relationship between knowledge and survival. In 'Salem's Lot, King uses the main character's interest in the horror genre to emphasize the importance of an exposure to the dark side of human nature. In Needful Things, King vividly shows the dire consequences of naiveté, or in other words, uneducated innocence. Desperation represents a culmination of King's ideas. The final novel in my analysis shows the power of youth tempered by knowledge of human nature and informed by religious conviction. King links religion and horror to show the power of both in religious survival and to show the ultimate morality of horror.
359

Arquitectura tecnológica basada en internet of things para monitorear las jornadas de pesca artesanal / Technological architecture based on internet of things to monitor the journeys of artisanal fishing

Ambrosio Mallqui, Jaime Jesus, Preguntegui Martinez, Leysa Jimena 27 September 2019 (has links)
En el Perú, la actividad pesquera artesanal es realizada por personas, grupos o pequeñas empresas y es definida como aquella que se realiza con o sin el empleo de embarcaciones. En caso de emplearlas, sus capacidades de bodega pueden llegar hasta 32,6 m3 de volumen y hasta 15 m de eslora con predominancia al trabajo manual durante la faena de pesca (IMARPE, 2017). Esta actividad, se caracteriza por no contar con tecnología o contar con tecnología precaria debido a la reducida cantidad de capital y energía. Por otro lado, cuentan con pequeñas embarcaciones de pesca, faenas de pesca cortas, áreas de pesca cercanas a la costa y su producción es para el consumo local. (Universidad del Pacífico, 2015). En el último censo realizado por PRODUCE e INEI se tenía cerca de 44.161 pescadores artesanales (IMARPE, 2017). Esta actividad, se ha convertido en un sector importante porque contribuye a la economía (IMARPE, 2017), especialmente en zonas costeras y a nivel nacional por su contribución a los índices de empleos (Universidad del Pacífico, 2015), contribuyendo a la reducción de la pobreza y a la seguridad alimenticia del país (FAO, 2016). Por tal motivo, el propósito del proyecto es implementar una arquitectura tecnológica basada en Internet of Things para monitorear las jornadas de pesca artesanal por medio de sensores y controladores. La motivación del presente trabajo radica en dos puntos importantes: Primero, brindar una infraestructura tecnológica a los pescadores artesanales. Segundo, monitorear las actividades de los pescadores artesanales. / In Peru, the artisanal fishing activity is carried out by individuals, groups, relatives or small businesses and is carried out with or without the use of boats. In case of using them, the capacity of boat can reach up to 32.6 m3 of volume and up to 15 m of length with predominance to manual work during the fishing operation (IMARPE, 2017). This activity is characterized by not having technology or having precarious technology due to the reduced amount of capital and energy. On the other hand, they have small fishing boats, short fishing operations, fishing areas near the shore and their production is for local consumption. (Universidad del Pacífico, 2015). In the last census conducted by PRODUCE and INEI there were about 44,161 artisanal fishermen (IMARPE, 2017). This activity has become an important sector because it contributes to the economy (IMARPE, 2017), especially in coastal areas and at the national level for its contribution to the indexes of employment (Universidad del Pacífico, 2015), contributing to the reduction of poverty and food security of the country (FAO, 2016). For this reason, the purpose of the project is to implement a technological architecture based on Internet of Things to monitor the journeys of artisanal fishing through sensors and controllers. The motivation of this work lies in two important points: First, to provide a technological infrastructure to artisanal fishermen. Second, to monitor the activities of artisanal fishermen. / Tesis
360

Cloud Services for Building the Modern Internet of Things : An Examination of IoT Cloud Service Providers

Sääf, Alexander January 2019 (has links)
As the IoT has grown in popularity, modern Cloud Providers have begun offering IoT-specific features. These features could provide IoT developers with a lot of aid, but they are new and relatively unexplored. This study aims to explore these IoT-specific features in order to build a better foundation for developers looking to leverage them to improve their IoT systems or development process. To do this, a literature study combined with a case study was carried out. The literature study gives insight into the current research around IoT and IoT cloud providers, for example with common issues and possible applications. The case study provides a reference of how a simple proof-of-concept system can be developed using two of the available providers: AWS IoT and Azure IoT.

Page generated in 0.2439 seconds