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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.
101

Protocol for a Systematic Literature Review on Security-related Research in Ubiquitous Computing

Kusen, Ema, Strembeck, Mark 18 December 2014 (has links) (PDF)
Context: This protocol is as a supplementary document to our review paper that investigates security-related challenges and solutions that have occurred during the past decade (from January 2003 to December 2013). Objectives: The objective of this systematic review is to identify security-related challenges, security goals and defenses in ubiquitous computing by answering to three main research questions. First, demographic data and trends will be given by analyzing where, when and by whom the research has been carried out. Second, we will identify security goals that occur in ubiquitous computing, along with attacks, vulnerabilities and threats that have motivated the research. Finally, we will examine the differences in addressing security in ubiquitous computing with those in traditional distributed systems. Method: In order to provide an overview of security-related challenges, goals and solutions proposed in the literature, we will use a systematic literature review (SLR). This protocol describes the steps which are to be taken in order to identify papers relevant to the objective of our review. The first phase of the method includes planning, in which we define the scope of our review by identifying the main research questions, search procedure, as well as inclusion and exclusion criteria. Data extracted from the relevant papers are to be used in the second phase of the method, data synthesis, to answer our research questions. The review will end by reporting on the results. Results and conclusions: The expected results of the review should provide an overview of attacks, vulnerabilities and threats that occur in ubiquitous computing and that have motivated the research in the last decade. Moreover, the review will indicate which security goals are gaining on their significance in the era of ubiquitous computing and provide a categorization of the security-related countermeasures, mechanisms and techniques found in the literature. (authors' abstract) / Series: Working Papers on Information Systems, Information Business and Operations
102

Data stream mining in fog computing environment with feature selection using ensemble of swarm search algorithms

Ma, Bin Bin January 2018 (has links)
University of Macau / Faculty of Science and Technology. / Department of Computer and Information Science
103

"Construção de aplicações de captura e acesso baseada em recorrência de funcionalidades" / "Building capture and access applications based on recurrence of funcionalities"

Cattelan, Renan Gonçalves 19 April 2004 (has links)
Aplicações de captura e acesso exploram o paradigma de computação ubíqua --- que consiste em popular o ambiente com aplicações e dispositivos computacionais a fim de auxiliar transparentemente as pessoas na realização de suas atividades --- para dar apoio à captura automática de informação em experiências ``ao vivo' e à correspondente geração de documentos passíveis de armazenamento, recuperação, visualização e extensão ao longo do tempo. Devido à sua natureza distribuída, à heterogeneidade dos dispositivos computacionais envolvidos e à diversidade nas funcionalidades providas, essas aplicações são difíceis de se construir e requerem infra-estruturas e serviços de software que auxiliem o desenvolvedor nessa tarefa. Este trabalho investiga a construção e o uso de aplicações de captura e acesso por meio do desenvolvimento da xINCA, uma infra-estrutura estendida baseada em componentes de software reutilizáveis que englobam as funcionalidades recorrentes nessa classe de aplicações. A xINCA é uma extensão da infra-estrutura INCA --- uma infra-estrutura de baixo nível que provê abstrações de comunicação para aplicações de captura e acesso. Complementares, as infra-estruturas INCA e xINCA provêem um modelo simplificado para o desenvolvimento de aplicações de captura e acesso, considerando aspectos de projeto, implementação e reuso. Associada ao modelo de armazenamento do serviço StRES, a xINCA tem ainda papel na estruturação da informação capturada com o uso de XML e tecnologias correlatas. / Capture and access applications explore the ubiquitous computing paradigm --- that basically consists on populating the environment with computational devices and applications to transparently assist people on their activities --- to support the automatic capture of information on live experiences and generate corresponding documents that can be further stored, retrieved, visualized and extended. Due to their distributed nature, heterogeneity of involved devices and variety of provided functionalities, capture and access applications are hard to build and require software infrastructures and services that help the developer out on his task. This work investigates the building and use of capture and access applications through the development of xINCA, a component-based software infrastructure comprising the most common func-tio-na-li-ties present in such a class of applications. xINCA is an extension of INCA --- a low-level infrastructure that provides communication abstractions for capture and access applications. Complementary, INCA and xINCA provide a simplified model for the development of capture and access applications, concerning design, implementation and reuse aspects. Allied with the StRES storage model, xINCA also plays an important role on the structuring of captured information by using XML and corresponding technologies.
104

Uso de informações de contexto em segurança computacional / Use of context information on computer security

Milagres, Francisco Gomes 07 October 2004 (has links)
Diariamente, novos sistemas ubíquos são desenvolvidos e integrados ao nosso cotidiano, cuja presença às vezes não é percebida pelos seus usuários. O objetivo deste trabalho é investigar as questões de segurança e privacidade existentes nos paradigmas de computação ubíqua e ciente de contexto. Utilizando um protótipo de TV interativa - TV-I (Goularte, 2003) - que possui características de mobilidade e ciência de contexto, este trabalho define um conjunto de requisitos mínimos para a garantia de segurança e privacidade em sistemas ubíquos. É também objetivo deste trabalho utilizar informações contextuais para gerenciamento dinâmico de requisitos de segurança e privacidade por meio de políticas expressas em linguagem EPAL. Para validar os resultados desta pesquisa, foi implementado o Gerente de Segurança como um serviço do protótipo TV-I. A principal característica desse gerente é controlar o acesso a informações pessoais por meio de informações de contexto fornecidas pelo Gerente de Contexto, de autoria de Santos (2004) / Every day, new ubiquitous systems are being developed and integrated into our daily routines, whose presence is sometimes not even perceived by the casual user. The aim of this work is to investigate questions of security and privacy in ubiquitous and context aware computing. Using a prototype for interactive television - TV-I (Goularte, 2003) - that has characteristics of mobility and contextual-awareness, this work defines a set of basic requirements that are fundamental in order to guarantee security and privacy in ubiquitous systems. Furthermore, this work uses contextual information in order to dynamically manage security and privacy requirements according to security and privacy policies that are expressed in the EPAL language. In order to validate the experimental results, a Security Manager has been implemented as a service of the TV-I prototype. The principal characteristic of this manager is to enforce access control over the personal information using contextual information of the ubiquitous system, and which is supplied via the Context Manager, designed by Santos (2004).
105

An attitude compensation technique for a MEMS motion sensor based digital writing instrument.

January 2006 (has links)
Luo Yilun. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2006. / Includes bibliographical references (leaves 87-91). / Abstracts in English and Chinese. / Chapter 1. --- Introduction --- p.1 / Chapter 1.1. --- Organization --- p.3 / Chapter 2. --- Architecture of MAG-μIMU --- p.5 / Chapter 2.1. --- Hardware for Attitude Filter --- p.5 / Chapter 2.2. --- Handwriting Recording for a Digital Writing Instrument --- p.7 / Chapter 3. --- Inertial Tracking for Handwriting --- p.9 / Chapter 3.1. --- Spatial Descriptions and Transformations --- p.9 / Chapter 3.1.1. --- Vector Description and Position of a Frame --- p.9 / Chapter 3.1.2. --- Coordinate Transformation and Orientation of a Frame --- p.10 / Chapter 3.1.3. --- Kinematics for Digital Writing Instruments --- p.12 / Chapter 3.1.4. --- Vector Rotation --- p.16 / Chapter 3.2. --- Euler Angles for Rotation in Space --- p.17 / Chapter 3.3. --- Euler Angles Attitude Kinematics --- p.19 / Chapter 3.4. --- Singular Problem --- p.19 / Chapter 4. --- Attitude in Quaternion --- p.22 / Chapter 4.1. --- Quaternion Operations --- p.22 / Chapter 4.1.1. --- Quaternion Conjugate --- p.23 / Chapter 4.1.2. --- Quaternion Norm --- p.24 / Chapter 4.1.3. --- Quaternion Inverse --- p.24 / Chapter 4.2. --- Orientation Description in Quaternion --- p.24 / Chapter 4.3. --- Attitude Kinematics in Quaternion --- p.25 / Chapter 5. --- Kalman Filter --- p.27 / Chapter 5.1. --- Time Update --- p.28 / Chapter 5.2. --- Measurement Update --- p.29 / Chapter 5.2.1. --- Maximum a Posterior Probability --- p.29 / Chapter 5.2.2. --- Batch Least-Square Estimation --- p.31 / Chapter 5.2.3. --- Measurement Update in Kalman Filter --- p.34 / Chapter 5.3. --- Kalman Filter Summary --- p.36 / Chapter 6. --- Extended Kalman Filter --- p.38 / Chapter 7. --- Attitude Extended Kalman Filter --- p.41 / Chapter 7.1. --- Time Update Model --- p.41 / Chapter 7.1.1. --- Attitude Strapdown Theory for a Quaternion --- p.41 / Chapter 7.1.2. --- Error Model for Time Update --- p.42 / Chapter 7.2. --- Measurement Update Model --- p.43 / Chapter 7.2.1. --- Error Model for the Measurement Update --- p.45 / Chapter 7.3. --- Summary --- p.46 / Chapter 8. --- Experiment Results --- p.47 / Chapter 8.1. --- Experiment for Attitude EKF based on MAG-μIMU --- p.47 / Chapter 8.1.1. --- Simulation Test --- p.48 / Chapter 8.1.2. --- Experiment Test --- p.49 / Chapter 8.2. --- Writing Application based on Attitude EKF Compensation --- p.52 / Chapter 8.2.1. --- Stroke Segment Kalman Filter --- p.54 / Chapter 8.2.2. --- Zero Velocity Compensation --- p.58 / Chapter 8.2.3. --- Complementary Attitude EKF for Writing Experiment --- p.60 / Chapter 9. --- Future Work --- p.73 / Chapter 9.1. --- Unscented Kalman Filter --- p.73 / Chapter 9.1.1. --- Least-square Estimator Structure --- p.73 / Chapter 9.1.2. --- Unscented Transform --- p.74 / Chapter 9.1.3. --- Unscented Kalman Filter --- p.76 / Chapter 9.2. --- Experiment Result --- p.81 / Chapter 10. --- Conclusion --- p.85 / Chapter 10.1. --- Attitude Extended Kalman Filter --- p.85 / Chapter 10.2. --- Complementary Attitude EKF --- p.85 / Chapter 10.3. --- Unscented Kalman Filter --- p.86 / Chapter 10.4. --- Future Work --- p.86 / Bibliography --- p.87 / Appendix A --- p.92
106

Ubiservices: um modelo para administração de serviços em ambientes ubíquos

Brand, Gustavo Bervian 28 April 2010 (has links)
Made available in DSpace on 2015-03-05T14:01:49Z (GMT). No. of bitstreams: 0 Previous issue date: 28 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / Com a evolução acelerada dos dispositivos computacionais, diminuição de tamanho e custo, ocorre uma imersão das pessoas no mundo digital. Com o uso de mais tecnologia, abundante e barata, surgem ambientes que tiram proveito da computação ubíqua, permitindo aos seus usuários uma interatividade e acesso a informações de forma fácil, ágil e natural. No entanto, ambientes ubíquos foram definidos em função da necessidade de uma grande infra-estrutura instalada para funcionar adequadamente, algo que não é uma realidade atualmente. Este trabalho apresenta uma alternativa aos ambientes ubíquos clássicos: um modelo para administração de serviços chamado Ubiservices. O objetivo do Ubiservices é fornecer conectividade em ambientes formados através de redes Ad Hoc não estruturadas, com aplicações como migração, replicação, publicação e busca de informações e serviços nesta rede. A interconexão das redes Ad Hoc ocorre através de uma rede overlay de forma transparente ao usuário, utilizando tecnologias existentes que, devi / With the fast evolution of the computing devices, its reduced size and cost, there is an immersion of people in the digital world. With the use of more technology, abundant and cheap, there are environments that can take advantage of the ubiquitous computing, allowing users to interact and have access to information easily, quickly and naturaly. However, ubiquitous environments were defined needing a large installed infrastructure to work properly, something that is not a reality nowadays. This work presents an alternative to the classic ubiquitous environments called Ubiservices. Its goal is to provide connectivity to environments made up of unstructured Ad Hoc networks, besides applications like migration, replication, publishing and search of information and services at the network. The interconnection of Ad Hoc networks occurs through an overlay network, user transparently, using existing technologies that, properly adapted and refined, can create a network that allows different mesh networks to interact
107

UbiPri : middleware para controle e gerenciamento de privacidade em ambientes ubíquos / UBiPri : middleware control and privacy management in ubiquitous environments

Leithardt, Valderi Reis Quietinho January 2015 (has links)
Atualmente em vários países já existem mais dispositivos e meios de comunicações que habitantes e a medida que a tecnologia avança a troca de informação tende a aumentar exponencialmente. Com isso, ganha destaque a área denominada computação ubíqua, que visa o desenvolvimento de aplicativos para automatizar processos, antes manuais, a fim de proporcionar conforto, rapidez e conexão aos usuários com seus dispositivos. Nos estudos realizados decorrer desta tese identificou–se a necessidade de desenvolver e controlar informações privadas fundamentadas no local, aqui denominado ambiente ubíquo. O problema de pesquisa identificado foi a grande heterogeneidade de dispositivos e comunicações nestes sistemas, tornando-os vulneráveis e expondo os dados de seus usuários. Assim, observou-se a necessidade de um modelo taxonômico de privacidade que engloba características necessárias para controlar e gerenciar a privacidade de dados em ambientes ubíquos. A partir dessa taxonomia desenvolveu–se um protótipo com base em um middleware estruturado em camadas necessárias para prover os controles e gerenciamentos necessários nestes ambientes. Os primeiros testes e resultados se mostraram promissores, tendo seus resultados publicados em conferências internacionais da área que nortearam os estudos para uma melhoria do tratamento e filtragem de dados. Também foi possível a ampliação dos controles e gerenciamento de parâmetros automáticos com aumento e redução de definição do tipo de perfil do usuário em adição são apresentados os resultados obtidos em diferentes cenários de uso e aplicação. Para tanto, o protótipo desenvolvido permite selecionar opções de variáveis atribuídas individualmente a cada ambiente de acordo com suas necessidades, com isso, a solução proposta visa ser empregada no gerenciamento de privacidade em ambientes ubíquos. Os resultados obtidos nos testes realizados comprovam a viabilidade e contribuição cientifica do modelo desenvolvido. O aplicativo UbiPri foi disponibilizado para utilização no google play store, podendo ser instalado e configurado na plataforma android. / Currently in many countries there are already more devices and communication means inhabitants and as technology advances the exchange of information tends to increase exponentially. As a result, stands out the area called ubiquitous computing, which aims to develop applications to automate processes before hand in order to provide comfort, speed and connecting users with their devices. In studies carried out throughout this thesis it identified the need to develop and control private information based on location, here called ubiquitous environment. The identified research problem was the great heterogeneity of devices and communications in these systems, making them vulnerable and exposing the data of its users. Thus, there was the need for a taxonomic model of privacy that encompasses features needed to control and manage data privacy in ubiquitous environments. From this taxonomy developed a prototype based on a middleware structured in layers to provide the necessary controls and managements required in these environments. The first tests and results were promising, with the results published in international conferences in the area that guided the studies for improved treatment and filtering of data. It was also possible the expansion of controls and management parameters with automatic increase and decrease setting in the user profile type in addition the results obtained are presented in different usage scenarios and application. Thus, the prototype allows you to select options variables individually assigned to each environment according to their needs, with it, the proposed solution is intended to be used in the privacy management in ubiquitous environments. The results obtained in the tests prove the feasibility and scientific contribution of the developed model. The UbiPri application was made available for use in the google play store and can be installed and configured on android platform.
108

Suporte para a criatividade musical cotidiana : mixDroid Segunda Geração / Support for everyday musical creativity : mixDroid Second Generation

Farias, Flávio Miranda de January 2015 (has links)
Atualmente é comum ver jovens e adultos utilizando das novas tecnologias digitais para atividades musicais como entretenimento. No entanto, a maioria limita-se somente ao papel de ouvinte, munidos de seus players de som, dificilmente ousando criar suas próprias composições ou sons, às vezes pelo custo de aplicações pagas, outras vezes pela complexidade inerente a aplicações voltadas a músicos. Esta pesquisa foi focada em simplificar a prática musical voltada ao público leigo e descompromissado. Quando se trata de software voltado a este nicho, não existem muitos disponíveis. Neste trabalho utilizamos conceitos e técnicas da Música Ubíqua para preencher esta lacuna: foi desenvolvido o protótipo mixDroid 2G CS, que propicia recursos para criação de mixagens em dispositivos móveis. Com este protótipo foram realizados testes com alunos de uma instituição de nível técnico em informática, utilizando equipamentos portáteis como celulares e tabletes Android. Neste volume, serão apresentados conceitos e definições técnicas do mixDroid 2G CS, assim como dois experimentos com usuários reais. Com base nos resultados dos experimentos, analisamos as implicações dos perfis dos produtos criativos e o desempenho dos sujeitos e indicamos as limitações e as perspectivas abertas para seu uso em atividades criativas, discutindo a sua viabilidade e possíveis aplicações futuras. / Nowadays, it is common to see young people and adults using new digital technologies for music production as entertainment. However, most people are only listeners, hardly ever daring to create their own compositions or sounds because of the cost and the complexity of the programs targeted for musicians. The purpose of this research is to simplify music production for the public without musical experience. In this study, we used concepts and techniques of Ubiquitous Music to solve various problems: a prototype software called mixDroid 2G CS was developed, which uses a new interaction metaphor for mixing sonic content on mobile devices. Tests were conducted with students of an institution devoted to technical courses in computer science. Targeting the use of portable devices, the Android system was used on a variety of cell phones and tablets. In this volume, I will present concepts and the technical description of mixDroid 2G CS, including two experiments with real users. Based on the results of the experiments, I analyzed the implications of the creative's products profiles and the subjects' performance during the tasks, and indicated the limitations and perspectives for its use in creative activities, discussing the feasibility of its application in future projects.
109

On the Selection of Just-in-time Interventions

Jaimes, Luis Gabriel 20 March 2015 (has links)
A deeper understanding of human physiology, combined with improvements in sensing technologies, is fulfilling the vision of affective computing, where applications monitor and react to changes in affect. Further, the proliferation of commodity mobile devices is extending these applications into the natural environment, where they become a pervasive part of our daily lives. This work examines one such pervasive affective computing application with significant implications for long-term health and quality of life adaptive just-in-time interventions (AJITIs). We discuss fundamental components needed to design AJITIs based for one kind of affective data, namely stress. Chronic stress has significant long-term behavioral and physical health consequences, including an increased risk of cardiovascular disease, cancer, anxiety and depression. This dissertation presents the state-of-the-art of Just-in-time interventions for stress. It includes a new architecture. that is used to describe the most important issues in the design, implementation, and evaluation of AJITIs. Then, the most important mechanisms available in the literature are described, and classified. The dissertation also presents a simulation model to study and evaluate different strategies and algorithms for interventions selection. Then, a new hybrid mechanism based on value iteration and monte carlo simulation method is proposed. This semi-online algorithm dynamically builds a transition probability matrix (TPM) which is used to obtain a new policy for intervention selection. We present this algorithm in two different versions. The first version uses a pre-determined number of stress episodes as a training set to create a TPM, and then to generate the policy that will be used to select interventions in the future. In the second version, we use each new stress episode to update the TPM, and a pre-determined number of episodes to update our selection policy for interventions. We also present a completely online learning algorithm for intervention selection based on Q-learning with eligibility traces. We show that this algorithm could be used by an affective computing system to select and deliver in mobile environments. Finally, we conducts posthoc experiments and simulations to demonstrate feasibility of both real-time stress forecasting and stress intervention adaptation and optimization.
110

Architectures et mécanismes de sécurité pour l'auto-protection des systèmes pervasifs

He, Ruan 30 November 2010 (has links) (PDF)
Contributions principales Les éléments précédents identifient les principes de conception de base pour construire un canevas logiciel d'auto-protection. Différentes technologies peuvent être choisies pour réaliser ces principes. Les contributions principales de cette thèse décrivent des mécanismes développés et mis en œuvre pour réaliser notre canevas logiciel d'auto-protection. Il s'agit des éléments suivants : - Une architecture a trois couches pour l'auto-protection : un espace d'exécution fournit un environnement d'exécution pour des applications; un plan de contrôle supervise l'espace d'exécution ; et un plan autonome guide le plan de contrôle en prenant en compte l'etat du systeme, l'evolution des risques, la strategie de securite definie par l'administrateur, et les preferences de l'utilisateur. - Une approche du contrôle d'acces a base d'attributs: l'approche proposee (appelee G-ABAC) exprime les politiques d'autorisation en se basant sur des attributs. Cette approche apporte a la fois une neutralite vis-a-vis du modele de contrôle d'acces, et une flexibilite permettant des manipulations elementaires sur ces politiques. - Un canevas logiciel a base de politiques pour realiser la gestion autonome de la securite : l'approche a base de politiques a montre ses avantages pour l'administration des systemes complexes et dynamiques. Un canevas logiciel autonome de politiques de securite (ASPF) fournit une solution coherente et decentralisee pour administrer les politiques d'autorisation pour les systemes pervasifs a grande echelle. L'integration des patrons autonomes ameliore egalement la souplesse et la facilite d'adaptation au contexte. - Un noyau de securite embarque pour l'application des politiques de contrôle d'acces : les politiques d'autorisation denies precedemment sont appliquees par une architecture d'autorisation au niveau du systeme d'exploitation. Ce noyau appele VSK contrôle l'acces aux ressources d'une maniere dynamique an de reduire le surcoût des mecanismes d'autorisation. Ce mecanisme permet egalement de supporter dierents types de politiques d'autorisation. - Un langage dedie (Domain-Specic Language ou DSL) pour la specication de politiques d'adaptation : toutes les adaptations de notre canevas logiciel d'auto-protection de bout en bout sont contr^olees par des strategies de haut niveau appelees politiques d'adaptation. Un DSL tenant compte de nombreux facteurs pour les decisions d'adaptation. est deni pour specier ces politiques.

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