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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.
371

Contribution à la flexibilité et à la rapidité de conception des systèmes automatisés avec l'utilisation d'UML

Chiron, Fabien 01 December 2008 (has links) (PDF)
La dynamique actuelle des marchés entraîne avec elle une complexité croissante des demandes du client et nécessairement des contraintes de production. Les méthodologies traditionnelles de conception de systèmes montrent leurs limites dans des contextes très changeants pour lesquels les spécifications sont amenées à évoluer rapidement, des éléments technologiques particuliers de réalisation étant souvent pris en compte trop tôt dans le travail d'étude, limitant la versabilité des développements. Les entreprises doivent alors capitaliser au maximum les efforts menés dans les phases amont de spécification pour optimiser les temps d'étude. Notre travail de recherche s'intéresse plus précisément au domaine des systèmes antomatisés et se propose de répondre à la problématique précédente en utilisant des techniques issues du monde de l'informatique pour la réalisation des sytèmes physiques, comme l'OOA (Approche Orienté Objet) et la modélisation objet UML (Langage de Modélisation Unifié) avec la perspective d'une spécialisation tardive et d'une génération automatique selon les cibles technologiques choisies, comme le préconise la logique IDM (Ingéniérie Dirigée par les Modèles). L'originalité de ce mémoire est de décrire une méthodologie et une organisation de travail pour la conception des systèmes automatisés, en s'appuyant sur le concept d'objet d'automatisme multi-facettes. De plus, nous proposons une utilisation de l'extension SysML (Langage de Modélisation des Systèmes) pour la représentation d'éléments d'automatismes particuliers, les blocs fonctions de la norme IEC 61131-3, à travers le stéréotype "block". Enfin nous montrons comment il est possible d'obtenir une première génération de code automate en passant par les spécifications PLCopen, définissant un lien entre une syntaxe XML (Langage de balisage eXtensible), se voulant standard, et les langages de la norme IEC 61131-3. Le passage par cette représentation standardisée permet de garder l'indépendance des implémentations vis-à-vis d'un environnement intégré de développement particulier. Le processus de conception décrit a été appliqué à un cas d'étude industriel réel appartenant au domaine de la palettisation robotisée.
372

Gnafuy : 基於行動裝置下的分散式運算研究 / Gnafuy : a framework for ubiquitous mobile computation

陳晉杰, Chen, Jin Jie Unknown Date (has links)
隨著科技日新月異的發展,智慧型手機本身通訊與運算能力也隨著軟體和硬體的改善而不斷地增強,其便利性與高機動性的特色使得越來越多人持有智慧型手機,最後成為人們生活中不可或缺的部份。總觀來說,持有與使用率的上升,不知不覺的形成一種共享經濟與無所不在的行動運算網絡。 基於普及性與相對優秀的運算效能,我們設計與實作出Gnafuy,一個基於行動裝置下的分散式運算框架,希望借用世界上所有閒置行動運算裝置的資源來實行無所不在的運算。 我們發展出一套應用程式介面(API)供開發者依照自己的需求來撰寫自己的分散式運算程式,藉由遵循Gnafuy所制定的應用程式介面,開發者可只專注在演算法本身的開發,而不需要在意其演算法如何被分配到手機上以及待處理資料的分配情形。本篇文章還討論了Gnafuy所採用的分散式運算的程式模型,以及我們如何藉由一個手機應用程式將任務部署至自願者的智慧型手機中,我們發展出一套伺服器端的機制來增加訊息傳遞的成功率,以及偵測計算後回傳結果是否正確,排除被惡意程式污染的客戶端結果。
373

[en] DEVELOPMENT AND EVALUATION OF A MOBILE GAME TO ENCOURAGE COMMUNICATION AMONG CHILDREN WITH AUTISM / [pt] DESENVOLVIMENTO E AVALIAÇÃO DE UM JOGO EM DISPOSITIVOS MÓVEIS PARA ESTIMULAR A COMUNICAÇÃO DE CRIANÇAS COM AUTISMO

PAULA CECCON RIBEIRO 26 February 2014 (has links)
[pt] Em torno de 50 por cento das pessoas com autismo apresentam dificuldades em desenvolver qualquer tipo de linguagem funcional. Este estudo apresenta o desenvolvimento e avaliação de um jogo colaborativo multiusuário para interface tangível portável. O jogo foi projetado a partir de requerimentos de um grupo de crianças com autismo, visando estimular a comunicação mediante estratégias colaborativas. Para isso, o jogo foi projetado para interação por duplas de usuários. Cada usuário dispõe de uma interface tangível portável para compartilhar recursos do jogo. Esse compartilhamento e observado pela dupla numa tela maior. O jogo foi avaliado seguindo aspectos de pesquisa relacionados com o interesse dos usuários frente a tecnologia, a percepção de cada usuario do seu interlocutor e as intenções de comunicação geradas entre os usuários para conseguirem colaborar entre si. Foram realizados testes durante 8 semanas com 4 crianças com autismo. Os resultados indicam que tanto o ambiente proporcionado pela tecnologia utilizada quanto as estratégias do jogo permitiram estimular nos usuários, em um ou outro grau, a comunicação através desse espaço de compartilhamento. / [en] About 50 per cent of people diagnosed with autism have dificulties in developing any kind of functional language. This paper presents the development and evaluation of a multi-user collaborative game for mobile tangible interfaces. The game was designed based on requirements of a group of children with autism, in order to stimulate communication through collaborative strategies. The game was designed for interaction by pairs of users. Each user has a mobile tangible interface to share game resources and a TV as a shared space. The game was evaluated following research aspects related to the interest of the users on the technology, the perception of each user s interlocutor and communication intentions observed between the users to collaborate with each other. Tests were carried out for 8 weeks with 4 children with autism. The results indicate that both the environment provided by the technology used as well as the strategies of the game have stimulated the users communication through this shared space.
374

[en] A MIDDLEWARE AND AN APPLICATION FOR COLLABORATIVE PRESENTATION SHARING ON HANDHELDS / [pt] UM MIDDLEWARE E APLICATIVO PARA APRESENTAÇÃO COLABORATIVA PARA DISPOSITIVOS MÓVEIS

MARCELO ANDRADE DA GAMA MALCHER 21 February 2008 (has links)
[pt] A atual evolução dos dispositivos computacionais móveis e a crescente ubiqüidade de redes sem fio possibilitam o desenvolvimento de serviços e aplicativos para colaboração entre usuários móveis nos mais variados ambientes como em domicílios, lugares públicos, universidades, empresas, entre outros. Em uma sala de aula, acredita-se que o uso de dispositivos móveis (com capacidade de comunicação sem fio) torna o aprendizado mais interativo e estimulante. Este trabalho descreve um aplicativo distribuído, denominado iPH (Interactive Presenter for Handhelds), que possibilita o compartilhamento e a co-edição de transparências entre o instrutor e os aprendizes em sala de aula, e os componentes de middleware utilizados no desenvolvimento do mesmo. O iPH pode ser executado em diferentes tipos de dispositivos como tablet pcs, notebooks e handhelds (palmtops ou smartphones), e acessa informações de contexto computacional do dispositivo para efetuar auto-adaptações na sua funcionalidade, para entre outros, melhorar a interação com o usuário. / [en] The ongoing improvement of portable devices and the increasing ubiquity of wireless networks enable the development of services and applications for anyplace- any-time collaboration among mobile users in many different environments, such as at home, in public areas, in universities, in companies, among others. It is expected that the use of portable, wireless-enabled devices in classrooms improves the interaction and engagement in the learning process. This work describes a distributed application named iPH (Interactive Presenter for Handhelds) that supports the sharing and co-edition of presentations among an instructor and students of a classroom, as well as the middleware components used for the development of iPH. This system can be executed on a wide range of devices, such as tablets, notebooks and handhelds (palmtops or smartphones), and uses the device`s context information to adapt itself to improve, for example, the interaction with the user.
375

[en] CONTEXT-SENSITIVE EXCEPTION HANDLING / [pt] TRATAMENTO DE EXCEÇÕES SENSÍVEL AO CONTEXTO

KARLA NAZARE FERREIRA DAMASCENO 23 October 2006 (has links)
[pt] Tratamento de erros em aplicações móveis sensíveis ao contexto não é uma tarefa trivial devido às características peculiares destes sistemas, como mobilidade, comunicação assíncrona e aumento de imprevisibilidade. Mecanismos convencionais de tratamento de exceções não podem ser utilizados por vários motivos. Primeiro, a propagação de erros deve considerar as mudanças contextuais que ocorrem constantemente nestes sistemas. Segundo, as atividades de recuperação de erros e a estratégia de tratamento de exceções também precisam freqüentemente ser selecionadas de acordo com as informações de contexto. Terceiro, a própria caracterização de uma exceção pode depender do contexto dos dispositivos envolvidos. Embora vários middlewares orientados a contexto ofereçam suporte ao desenvolvimento de aplicações móveis, estes sistemas raramente fornecem suporte adequado ao tratamento de exceções. Este trabalho realiza uma análise das soluções existentes para tratamento de exceções, considerando os requisitos de sensibilidade ao contexto. Além disso, são propostos um modelo para tratamento de exceções sensível ao contexto e um mecanismo implementado a partir de MoCA (Mobile Collaboration Architecture). MoCA é um middleware publish-subscribe que oferece suporte ao desenvolvimento de aplicações móveis colaborativas através da incorporação de serviços de contexto. Finalmente, este trabalho avalia o mecanismo de exceções proposto através de sua utilização em alguns protótipos de aplicações colaborativas desenvolvidas a partir de MoCA. Através do mecanismo, foram implementadas diferentes estratégias de tratamento de exceções que consideram as informações de contexto das aplicações. / [en] Context-sensitive exception handling on mobile systems is not a trivial task due to their intrinsic characteristics: mobility, asynchrony and increased unpredictability. Conventional mechanisms of exception handling can not be used for many reasons. First, error propagation needs considering the contextual changes that often occur in these systems. Second, error recovery and exception handling strategies also frequently need to be selected according to contextual information. Third, the characterization of an exception may depend on the contextual situation of involved devices. Even though there are now several context-oriented middleware systems that provide support for the development of mobile applications, they rarely provide explicit and adequate features for contextsensitive exception handling. This work presents an analysis of existing exception handling mechanisms, which to some extent consider the context-awareness requirements. Besides, it proposes a general model for context-sensitive exception handling and a supporting mechanism implemented using the MoCA (Mobile Collaboration Architecture) infrastructure. MoCA is a publish-subscribe middleware supporting the development of collaborative mobile applications by incorporating explicit services to empower software agents with contextsensitiveness. Finally, this paper reports our experience in implementing contextaware exception handling strategies in some prototype collaborative applications built with the MoCA system.
376

An uncertainty-aware reputation system in mobile networks: analysis and applications

Unknown Date (has links)
Many emerging mobile networks aim to provide wireless network services without relying on any infrastructure. The main challenge in these networks comes from their self-organized and distributed nature. There is an inherent reliance on collaboration among the participants in order to achieve the aimed functionalities. Therefore, establishing and quantifying trust, which is the driving force for collaboration, is important for applications in mobile networks. This dissertation focuses on evaluating and quantifying trust to stimulate collaboration in mobile networks, introducing uncertainty concepts and metrics, as well as providing the various analysis and applications of uncertainty-aware reputation systems. Many existing reputation systems sharply divide the trust value into right or wrong, thus ignoring another core dimension of trust: uncertainty. As uncertainty deeply impacts a node's anticipation of others' behavior and decisions during interaction, we include it in the reputation system. Specifically, we use an uncertainty metric to directly reflect a node's confidence in the sufficiency of its past experience, and study how the collection of trust information may affect uncertainty in nodes' opinions. Higher uncertainty leads to higher transaction cost and reduced acceptance of communication. We exploit mobility to efficiently reduce uncertainty and to speed up trust convergence. We also apply the new reputation system to enhance the analysis of the interactions among mobile nodes, and present three sample uncertainty-aware applications. We integrate the uncertainty-aware reputation model with game theory tools, and enhance the analysis on interactions among mobile nodes. / Instead of reactively protecting the mobile networks from existing attacks as in the traditional security paradigms, the analysis in this dissertation gives more insights on nodes' rationality in the interaction, which will enable the mechanism design in mobile networks to be security and incentive compatible. Moreover, we present three sample applications, in which we clearly identify the challenges, specifically formalize the problems, and cleverly employ the uncertainty mitigation schemes. These applications show that the uncertainty definition and mitigation schemes can benefit a broad range of applications, including fields such as security, network services, and routing. / by Feng Li. / Vita. / Thesis (Ph.D.)--Florida Atlantic University, 2009. / Includes bibliography. / Electronic reproduction. Boca Raton, Fla., 2009. Mode of access: World Wide Web.
377

Secure routing in wireless sensor networks

Unknown Date (has links)
This research addresses communication security in the highly constrained wireless sensor environment. The goal of the research is twofold: (1) to develop a key management scheme that provides these constrained systems with the basic security requirements and evaluate its effectiveness in terms of scalability, efficiency, resiliency, connectivity, and flexibility, and (2) to implement this scheme on an appropriate routing platform and measure its efficiency. / The proposed key management scheme is called Hierarchical Key Establishment Scheme (HIKES). In HIKES, the base station, acting as the central trust authority, empowers randomly selected sensors to act as local trust authorities, authenticating on its behalf the cluster members and issuing to them all secret keys necessary to secure their communications. HIKES uses a novel key escrow scheme that enables any sensor node selected as a cluster head to generate all the cryptographic keys needed to authenticate other sensors within its cluster. This scheme localizes secret key issuance and reduces the communication cost with the base station. The key escrow scheme also provides the HIKES with as large an addressing mechanism as needed. HIKES also provides a one-step broadcast authentication mechanism. HIKES provides entity authentication to every sensor in the network and is robust against most known attacks. We propose a hierarchical routing mechanism called Secure Hierarchical Energy-Efficient Routing protocol (SHEER). SHEER implements HIKES, which provides the communication security from the inception of the network. SHEER uses a probabilistic broadcast mechanism and a three-level hierarchical clustering architecture to improve the network energy performance and increase its lifetime. / Simulation results have shown that HIKES provides an energy-efficient and scalable solution to the key management problem. Cost analysis shows that HIKES is computationally efficient and has low storage requirement. Furthermore, high degree of address flexibility can be achieved in HIKES. Therefore, this scheme meets the desired criteria set forth in this work. Simulation studies also show that SHEER is more energy-efficient and has better scalability than the secure version of LEACH using HIKES. / by Jamil Ibriq. / Thesis (Ph. D.)--Florida Atlantic University, 2007. / Includes bibliography. / Also available in print. / Electronic reproduction. Boca Raton, FL : 2007. Mode of access: World Wide Web.
378

An Ant Inspired Dynamic Traffic Assignment for VANETs: Early Notification of Traffic Congestion and Traffic Incidents

Unknown Date (has links)
Vehicular Ad hoc NETworks (VANETs) are a subclass of Mobile Ad hoc NETworks and represent a relatively new and very active field of research. VANETs will enable in the near future applications that will dramatically improve roadway safety and traffic efficiency. There is a need to increase traffic efficiency as the gap between the traveled and the physical lane miles keeps increasing. The Dynamic Traffic Assignment problem tries to dynamically distribute vehicles efficiently on the road network and in accordance with their origins and destinations. We present a novel dynamic decentralized and infrastructure-less algorithm to alleviate traffic congestions on road networks and to fill the void left by current algorithms which are either static, centralized, or require infrastructure. The algorithm follows an online approach that seeks stochastic user equilibrium and assigns traffic as it evolves in real time, without prior knowledge of the traffic demand or the schedule of the cars that will enter the road network in the future. The Reverse Online Algorithm for the Dynamic Traffic Assignment inspired by Ant Colony Optimization for VANETs follows a metaheuristic approach that uses reports from other vehicles to update the vehicle’s perceived view of the road network and change route if necessary. To alleviate the broadcast storm spontaneous clusters are created around traffic incidents and a threshold system based on the level of congestion is used to limit the number of incidents to be reported. Simulation results for the algorithm show a great improvement on travel time over routing based on shortest distance. As the VANET transceivers have a limited range, that would limit messages to reach at most 1,000 meters, we present a modified version of this algorithm that uses a rebroadcasting scheme. This rebroadcasting scheme has been successfully tested on roadways with segments of up to 4,000 meters. This is accomplished for the case of traffic flowing in a single direction on the roads. It is anticipated that future simulations will show further improvement when traffic in the other direction is introduced and vehicles travelling in that direction are allowed to use a store carry and forward mechanism. / Includes bibliography. / Dissertation (Ph.D.)--Florida Atlantic University, 2016. / FAU Electronic Theses and Dissertations Collection
379

Face Processing Using Mobile Devices

Unknown Date (has links)
Image Processing and Computer Vision solutions have become commodities for software developers, thanks to the growing availability of Application Program- ming Interfaces (APIs) that encapsulate rich functionality, powered by advanced al- gorithms. To understand and create an e cient method to process faces in images by computers, one must understand how the human visual system processes them. Face processing by computers has been an active research area for about 50 years now. Face detection has become a commodity and is now incorporated into simple devices such as digital cameras and smartphones. An iOS app was implemented in Objective-C using Microsoft Cognitive Ser- vices APIs, as a tool for human vision and face processing research. Experimental work on image compression, upside-down orientation, the Thatcher e ect, negative inversion, high frequency, facial artifacts, caricatures and image degradation were completed on the Radboud and 10k US Adult Faces Databases along with other images. / Includes bibliography. / Thesis (M.S.)--Florida Atlantic University, 2016. / FAU Electronic Theses and Dissertations Collection
380

PeLeP: um modelo de perfil de aprendiz orientado à aprendizagem ubíqua / PeLeP pervaise learning profile

Levis, Darci 22 February 2007 (has links)
Made available in DSpace on 2015-03-05T13:59:41Z (GMT). No. of bitstreams: 0 Previous issue date: 22 / Nenhuma / A computação ubíqua traz várias potencialidades para os processos de ensino e aprendizagem. Do ponto de vista educacional, o desfio é a criação de um ambiente de aprendizagem móvel que proporcione recursos apropriados para o aprendiz. No cenário da aprendizagem ubíqua, a criação de um Perfil de Aprendiz, que una suas localizações, interesses e informações referentes a seu estudo torna-se importante. A dissertação apresenta o PeLeP-Pervasive Learning Profile, queconsiste em um modelo de aprendiz voltado para sistemas de suporte à aprendizagem ubíqua. O objetivo do PeLeP-Pervasive é possibilitar que aplicações educacionais possam explorar o ensino e a aprendizagem ubíquos, baseando-se em um perfil organizado em categorias que contém informações da vida cotidiana do aprendiz. O perfil do aprendiz no PeLeP é refinado e enriquecido através de inferências. estas, são baseadas na mobilidade do aprendiz por contexto, pelas tarefas que ele executa nos mesmos dentro de um ambiente de computação ubíqua. / The ubiquitous computing brings several potentialities for the processes of teaching and learning. Of the educational point of view, the callenge it is the creation of an environment of mobile learning that provides resources adapted for the learner. In the scenario of the learning ubiquitous, the creation of a Learner Profile, that unites yours locations, interests and referring information its study he/she becomes important. This dissertation presents PeLeP – Pervasive Learning Profile, which consists in a learner profile model oriented to ubiquitous learning systems. PeLeP aims to let applications explore ubiquitous education and learning through user profiles organized by categories containing information about that learner’s daily life. Learner profiles in PeLeP are defined and enriched through inferences. These inferences are based on several factors, such as learner’s mobility between contexts, and the tasks he executes in each of them while inside a ubiquitous computing environment

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