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  • 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.
71

Mot nätverkssjukvård i komplex miljö : - behov av en vetenskaplig syn på ledning för säker vård och effektiv resursanvändning / Towards networked healthcare in complex environment : – need for a developed scientific view on management for safe care and efficient use of resources

Lagerstedt, Marianne January 2016 (has links)
Since 2008 advanced home healthcare agencies (ASiH) in a larger Swedish county council has underwent a transformation, to become part of a coming concept: networked healthcare (NVS). NVS means that intermediate multi-organizational healthcare (IMV) will be produced often in the home, and from 2013 to an increasing number of patients in different age groups with different diagnoses and medical conditions - in large variability of needs. At the same time IMV has proved to be not simply practical to implement in a resource-efficient and patientsafe way. Based on theories from Command and Control Science the safetyproblem that arise in connection with IMV is a sign of the less known increasing need of the direction and coordination support that IMV requires. With a casestudy based research approach with interactive elements, different qualitative methods has been used in two phases between 2008 - 2013. The first phase is characterized by a phenomenological approach, while the second phase has a critical hermeneutic approach. Research methods includes fieldvisits with informal discussions, in-depth interviews, validation with respondents and two different methodologies for textanalysis. The main result shows that practical aggravating circumstances for safe care consists of lesser known and from 2013 increasing problems with direction and coordination, through expanded advanced IMV in the home as a part of NVS concept. This also as a result of inadequate and inappropriate direction and coordination support for IMV. The thesis concludes that the NVS represents a resource intensive health care concept, which requires a new view on the management issue and a network-related methodology for direction and coordination. This is to promote ethical, equitable, patientsafe and dignified advanced IMV so an optimized use of resources can be implemented, through shared responsibility and coordination in patientuniquely designed networkconstellations as a given work model. / <p>QC 20160926</p>
72

Lusten att lära : En studie kring varför människor väljer att lära sig något de inte måste / The desire to learn

Bergman, Madeleine January 2019 (has links)
This study focuses on historical reenactment, and the informal learning that takes place within that subculture. Through observations during events, and informal semi-structured interviews I have tried to identify some of the aspects that contribute to the motivation to learn that is prominent within the historical reenactment community. Why do people choose to learn things that they do not have to? What can I learn from that, and use to improve my own teaching? The study finds that some of the key facors for the motivation to learn is: having a social context that gives feedback and encouragement, beeing able to get practical use out of the knowledge you try to obtain, feeling satisfied with your own work, and having an enthusiastic teacher who can capture your curiosity.   The study also includes photographic works that aim to show some of the informal learning that takes place within the historical reenactment community. The purpose is also to initiate thoughts and discussions concerning informal learning and learning processes in general. Along with the photographs there are sounds taken from the interviews made during the study. The people heard give their perspective on the motivation to learn. Both photographs and sound were displayed in the Vårutställning at Konstfack.   Lastly I put forward some suggestions as to how teaching might be improved in order to help students feel more motivated to learn.
73

Exploring educators experiences implementing open educational practices

Paskevicius, Michael 17 December 2018 (has links)
This research focuses on how educators are using openly accessible sources of knowledge and open-source tools in ways that impact their pedagogical designs. Using a phenomenological approach with self-identifying open education practitioners, I explore how open educational practices (OEP) are being actualized in formal higher education and impacting learning design. Specifically, I examine how educators are bringing elements of openness into their everyday teaching and learning practice using educational technologies. I draw upon Giddens (1986) structuration theory, further developed for use in technology adoption research most notably by DeSanctis and Poole (1994) and Orlikowski (2000). This approach positions technologies as being continually socially constructed, interpreted, and put into practice. In an organizational context, the use of technology is intrinsically linked with institutional properties, rules and norms, as well as individual perceptions and knowledge. The findings suggest that OEP represents an emerging form of learning design, which draws from existing models of constructivist and networked pedagogy. Open technologies are being used to support and enable active learning experiences, presenting and sharing learners work in real-time, allowing for formative feedback, peer review, and ultimately, promoting community-engaged coursework. By designing learning in this way, faculty offer learners an opportunity to consider and practice developing themselves as public citizens and develop the knowledge and literacies for working with copyright and controlling access to their online contributions, while presenting options for extending some of those rights to others. Inviting learners to share their work widely, demonstrates to them that their work has inherent value beyond the course and can be an opportunity to engage with their community. Dataset available: https://doi.org/10.5683/SP2/CA77BB / Graduate
74

Eléments d'observation et d'estimation pour les systèmes contrôlés en réseaux / Elements of Observation and Estimation for Networked Control Systems

Etienne, Lucien 08 April 2016 (has links)
Les systèmes de contrôle en réseau sont un champ actif de recherche, où les différentes composantes du réseau sont spatialement distribué et tentent d'atteindre un objectif global. Ils apparaissent naturellement lors l'interaction d'un système piloté par ordinateur avec le monde physique.Avec les systèmes de contrôle en réseau une classe connexe des systèmes est décrit par les systèmes Cyber-physique, où les capacités de calcul embarqué peuvent interagir avec le monde physique.Dans ce travail, nous allons considérer la tâche classique d'observation et d'estimation et étudier les cas où les contraintes induite par le réseau nécessite une adaptation des mécanismes classique d'observation et d'estimation.Dans les système de contrôle en raison de limitation des capteurs (pour des raisons pratiques telles que la réduction des coûts) certains états ou paramètre du système ne sont pas connus. Dans ce contexte, la notion classique d'observabilitéexprime la capacité de déduire de la mesure les valeurs d'intérêt.Premièrement nous considérons le problème de la réduction de l'échantillonnage par l'utilisation de échantillonnage événementiel et ce pour plusieurs classes de systèmes. Ensuite, une procédure d'estimation et de contrôle sera proposé pour résoudre le problème du consensus dans un système multi-agent.Considérant enfin une dynamique de véhicule plus complexe, nous nous concentrons sur l'estimation du coefficient de frottement de la route pour résoudre un problème de suivi. / Network control systems is an active field of study where interacting component spatially distributed try to achieve a global goal. They naturally emerge from the interaction of computer driven mechanism and the physical world.Along with network control system a related class of systems is described by the so called: Cyber-physical systems, where integrated physical computational capabilities can interact.In this work we will consider the classical task of observation and estimation and investigate cases where network induced constraint calls for adapted observation and estimation scheme.In control system due to limitation in sensors ( for practical reason such as cost reduction) all the value of interest (whether the some unmeasured state or unknown parameter)are unknown. The classical notion of observabilityaccount for the ability to deduce from measurement those value of interest.First sampling reduction by use of event trigger will be studied for several class of systems. Then an estimation and control scheme will be establish to solve the problem of consensus in a multi agents system.Finally considering a more complex vehicle dynamic we focus on the estimation of tire road friction coefficient to solve a tracking problem.
75

Multi-agent persistent monitoring of a finite set of targets

Yu, Xi 20 February 2018 (has links)
The general problem of multi-agent persistent monitoring finds applications in a variety of domains ranging from meter to kilometer-scale systems, such as surveillance or environmental monitoring, down to nano-scale systems such as tracking biological macromolecules for studying basic biology and disease. The problem can be cast as moving the agents between targets, acquiring information from or in some fashion controlling the states of the targets. Under this formulation, at least two questions need to be addressed. The first is the design of motion trajectories for the agents as they move among the spatially distributed targets and jointly optimize a given cost function that describes some desired application. The second is the design of the controller that an agent will use at a target to steer the target's state as desired. The first question can be viewed in at least two ways: first, as an optimal control problem with the domain of the targets described as a continuous space, and second as a discrete scheduling task. In this work we focus on the second approach, which formulates the target dynamics as a hybrid automaton, and the geometry of the targets as a graph. We show how to find solutions by translating the scheduling problem into a search for the optimal route. With a route specifying the visiting sequence in place, we derive the optimal time the agent spends at each target analytically. The second question, namely that of steering the target's state, can be formulated from the perspective of the target, rather than the agent. The mobile nature of the agents leads to intermittencontrol, such that the controller is assumed to be disconnected when no agent is at the target. The design of the visiting schedule of agents to one target can affect the reachability (controllability) of this target's control system and the design of any specific controller. Existing test techniques for reachability are combined with the idea of lifting to provide conditions on systems such that reachability is maintained in the presence of periodic disconnections from the controller. While considering an intermittently connected control with constraints on the control authority and in the presence of a disturbance, the concept of 'degree of controllability' is introduced. The degree is measured by a region of states that can be brought back to the origin in a given finite time. The size of this region is estimated to evaluate the performance of a given sequence.
76

Controle baseado em eventos para sistemas em tempo discreto

Groff, Leonardo Broering January 2016 (has links)
Este trabalho aborda o problema de controle baseado em eventos para sistemas em tempo discreto, considerando que o sistema possui os dispositivos atuadores e sensores em nós diferentes e separados por uma rede de comunicação. A estratégia baseada em eventos consiste em reduzir a utilização da rede ao transmitir as informações do sensor para o atuador apenas quando um evento é gerado pela violação de um determinado limiar pela função de disparo. Primeiramente, são formuladas condições para a estabilidade de um sistema linear com realimentação estática de estados sob a estratégia proposta, com base na teoria de Lyapunov. Como as condições são postas na forma de desigualdades matriciais lineares (LMIs, do inglês linear matrix inequalities), problemas de otimização convexos podem ser utilizados na determinação dos parâmetros da função de disparo, bem como na resolução do problema de co-design, ou seja, do projeto simultâneo do controlador e da função de disparo, os quais são providos na sequência. A partir deste resultado básico, a metodologia é estendida para o caso em que ocorre a saturação do atuador. A seguir, é apresentada a extensão da metodologia para o caso em que o estado da planta não está disponível para o sensor, sendo então utlizado um observador de estados, considerando-se tanto o caso em que o modelo da planta utilizado no observador corresponde exatamente à dinâmica real da planta quanto o caso em que este modelo apresenta incertezas. Exemplos numéricos são apresentados para ilustrar todas as classes de sistemas consideradas, com os quais constata-se que a estratégia proposta é eficiente na redução da utilização dos recursos da rede de comunicação. / This work approaches the problem of event-triggered control for discrete time systems, considering that the system has the actuator and sensor devices in different nodes, separated by a communication network. The event-triggered strategy consists in reducing the utilization of the network by only transmitting the information from the sensor to the actuator when an event is generated by the violation of a determined threshold by the trigger function. Firstly, conditions for the stability of a linear system with a static state feedback under the proposed strategy are formulated based on the Lyapunov theory. Since the conditions are given in the form of linear matrix inequalities (LMIs), convex optimization problems can be used for the determination of the trigger function parameters, as well as the co-design of the feedback gain and the trigger function, which are given next. From this basic result, the methodology is extended to the case where occurs the saturation of the actuator. Following, the extension of the methodlogy to the case in which the plant states are not available for measure is presented, and a state-observer is used, considering both the case that the plant model corresponds exactly to the real plant dynamics and the case where this model has uncertainties. Numeric examples are shown to illustrate all the system classes considered, with which it is found that the proposed strategy is efficient in the reduction of the network resources utilization.
77

Battery-free Visible Light Sensing

Soleiman, Andreas January 2019 (has links)
In this thesis, we show that it is possible to design a battery-free light sensing system that can sense and communicate hand gestures while operating fully on harvested power from indoor light. We present two main innovations that push our system to tens of microwatts of power to enable battery-free operation. First, we introduce a novel visible light sensing system that can track variations in light intensity by using a solar cell as a sensor. Solar cells are unlike photodiodes optimized for energy yield in the visible light region and hence do not require any power hungry active components such as an operational amplifier. Furthermore, solar cells can operate under more diverse light conditions as they are not susceptible to saturation under bright light. Second, we devise two ultra-low power communication mechanisms based on radio frequency backscatter to transmit sensor readings at various resolutions without the need of any energy-expensive computational blocks.  We design two battery-free and self-powered hardware prototypes that are based on these two innovations. Our first design utilizes an on-board comparator based circuit to perform a 1-bit digitization of changes in light readings, consuming only sub-microwatt of power for digitization. For our second prototype, we design an analog backscatter mechanism that can map raw sensor readings directly to backscatter transmissions. We demonstrate the feasibility of our designs when sensing significant changes in light intensity caused by shadows from hand gestures, and reconstruct these at a receiving device. Our results demonstrate the ability to sense and communicate various hand gestures at a peak power of 20 microwatts when performing 1-bit digitization, and a mean power of 60 microwatts when performing analog backscatter. Both designs represent orders of magnitude improvement in terms of power consumption over state-of-the-art visible light sensing systems. / Battery-free Visible Light Sensing / MobiCom: G: Battery-free Visible Light Sensing
78

CODES : an interactive novice-oriented web-based environment for cooperative musical prototyping / Um ambiente cooperativo e interativo na web para prototipação musical

Miletto, Evandro Manara January 2009 (has links)
Criação musical é considerada uma atividade individual realizada por músicos. Desde que a música tem servido como motivação natural para formação de comunidades, novas modalidades tem sido criadas por meio do uso da tecnologia e uma potencial convergência de atividades sociais e a criação musical é campo denominado Networked Music (música em rede), que permite que pessoas explorem as implicações da interconexão de seus computadores e compartilhem experiências musicais como atividades sociais através da música. Esta tese assume que um ambiente de música em rede, se projetado especificamente para isso, pode estimular formas sociais de criação musical, mesmo para usuários leigos em música - pessoas que não possuem conhecimento musical. O objetivo desta tese é investigar como a tecnologia musical pode proporcionar suporte adequado para criação musical e discutir como é possível eliminar obstáculos naturais para esta atividade, bem como definir requisitos orientados especificamente para leigos em música. Como resultado principal e ambiente para teste desta pesquisa, apresentar CODES (Cooperative Music Prototypes Design - Projeto de Protótipos Musicais Cooperativos) - um ambiente baseado na Web, direcionado e projetado para suportar criação musical cooperativa por leigos em música. A natureza prototípica de CODES está projetada e contruída sob uma perspectiva orientada a leigos, para proporcionar-lhes condições para experimentação com música combinando, ouvindo e rearranjando padrões sonoros para criar peças musicais simples - chamadas Protótipos Musicais. Ainda, os usuários de CODES podem cooperar com parceiros num processo de criação de protótipos musicais cíclico e colaborativo (chamado Prototipação Musical Cooperativa ), usando mecanismos de percepção, argumentação e negociação personalizados para permitir que um estágio consensual final seja atingido. Ao longo deste volume, os principais conceitos, princípios, requisitos e características de CODES são apresentados e os detalhes do projeto, implementação e avaliação com usuários reais são descritos. / Music creation is considered as mostly a solitary activity performed by musicians. Since music has traditionally served as a natural motivation for community formation, new modalities have been created by means of use of technology, and one potential convergency of social activities and music making is the field of "Networked Music". It allows people to explore the implications of interconnecting their computers, and share musical experience as a social activity through music. This thesis assumes that a networked music environment - if specifically designed for that - can stimulate social ways of music creation, even by novices in music - people assumed to have no previous knowledge of music. The goal of this thesis is to investigate how networked music technology can provide adequate support for music creation, to discuss how it is possible to overcome a set of natural barriers, and to define requirements specifically oriented to users novices in music, and, as the main result and testbed of this research, to introduce CODES (Cooperative Music Prototypes Design) - a Web-based novice-oriented environment designed to support cooperative music creation. The prototypical nature of CODES is designed and built in order to provide a novice-oriented perspective, as a novice may experiment with music by combining, listening and rearranging pre-defined sound patterns to create simple musical pieces - called Music Prototypes. Furthermore, CODES users may cooperate with partners in a cyclical and collaborative process of music prototypes creation - called Cooperative Music Prototyping, using customized awareness, argumentation, and negotiation mechanisms until a final consensual music prototype stage is reached. Throughout this volume, the main concepts, principles, requirements and characteristics of CODES are presented, and the details of design, implementation of CODES and its evaluation by actual users are described.
79

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.
80

Secure Mobile Authentication for Linux Workstation log on

Habib, Usman January 2010 (has links)
Password based logon schemes have many security weaknesses. For secure environments smart card and biometric based authentication solutions are available as replacement for standard password based systems. Nevertheless, the cost of deployment and maintenance of these systems is quite high. On the other hand, mobile network operators have a huge base of deployed smart cards that can be reused to provide authentication in other spheres significantly reducing costs. In this project we present a study of how mobile phones can be used to provide a secure low-cost two-factor workstation logon solution.To find and study the available mobile phone based authentication architectures and come up with workstation logon architecture the study of relevant technologies utilized in these solutions: UMTS networks, Bluetooth communication, Remote Authentication Dial in User Service (RADIUS), authentication and authorization in Windows, Linux, and MAC OS X. The analysis of available mobile phone based authentication schemes like SIM Strong schemes based on EAP-SIM, Session-ID based schemes, and OTP based schemes are also added.A solution for Linux workstation logon process has been proposed in the thesis using the Pluggable Authentication Module (PAM). The Solution uses 2 factors for authentication, one is the static password and the second factor is the mobile based authentication using a 13 character long OTP. With adding the existing technology and giving the administrator the option of selecting the authentication method for user makes the solution more suitable for an enterprise.

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