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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.
161

Roteamento baseado em entropia de mobilidade para sensores sem fio conectados a Internet das coisas

Tavares, Vitor Palmeira 26 February 2016 (has links)
Submitted by Divisão de Documentação/BC Biblioteca Central (ddbc@ufam.edu.br) on 2017-02-20T12:37:03Z No. of bitstreams: 2 license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Dissertação - Vitor P. Tavares.pdf: 4739238 bytes, checksum: 3b69389125b82fa3ac9d0094b5d47d3e (MD5) / Approved for entry into archive by Divisão de Documentação/BC Biblioteca Central (ddbc@ufam.edu.br) on 2017-02-20T12:37:19Z (GMT) No. of bitstreams: 2 license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Dissertação - Vitor P. Tavares.pdf: 4739238 bytes, checksum: 3b69389125b82fa3ac9d0094b5d47d3e (MD5) / Approved for entry into archive by Divisão de Documentação/BC Biblioteca Central (ddbc@ufam.edu.br) on 2017-02-20T12:37:31Z (GMT) No. of bitstreams: 2 license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Dissertação - Vitor P. Tavares.pdf: 4739238 bytes, checksum: 3b69389125b82fa3ac9d0094b5d47d3e (MD5) / Made available in DSpace on 2017-02-20T12:37:32Z (GMT). No. of bitstreams: 2 license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Dissertação - Vitor P. Tavares.pdf: 4739238 bytes, checksum: 3b69389125b82fa3ac9d0094b5d47d3e (MD5) Previous issue date: 2016-02-26 / FAPEAM - Fundação de Amparo à Pesquisa do Estado do Amazonas / Electronic devices known as smart devices are used in wireless sensor networks in a interactive and autonomous way with the physical world. These devices when connected to the internet through these networks become the internet ubiquitous. Wireless Sensor Networks have specific protocols, such as Routing Protocol for Low-Power and Lossy - RPL. The RPL is a consolidated routing protocol and was developed specifically for environments without mobility. Several proposals have been proposed to adapt RPL in order to achive mobility requirements and specific issues. This work aims to propose adjustments to the RPL in order to fill the mobility requirements. A proposal of framework based on mobility entropy to be integrated into the RPL and then simulated extensively in an emulator for Internet of things and wireless sensor networks.The mobility entropy-based architecture considers the displacement of nodes as a deciding factor to define the routes by which the nodes transmit and receive packets. The experimental results show that the proposed method can be effectively and efficiently to reduce packet loss and latency in networks with RPL mobility. / Dispositivos eletrônicos conhecidos como dispositivos inteligentes são utilizados em redes de sensores sem fio de forma interativa e autônoma com o mundo físico. Estes dispositivos quando conectados a internet através destas redes tornam a internet mais ubíqua. As redes de sensores sem fio possuem protocolos específicos, como o protocolo de roteamento para redes de baixa potência e perdas (do inglês, Routing Protocol for Low-Power and Lossy Networks - RPL). O RPL é um protocolo de roteamento consolidado e foi desenvolvido especificamente para ambientes sem mobilidade. Várias propostas tem sido desenvolvidas para adequar o RPL à mobilidade para atender requisitos ou questões específicas. Este trabalho tem como objetivo propor adequações para que o RPL corresponda as necessidades da mobilidade em sensores sem fio de forma abrangente. A metodologia consiste na proposta de uma arquitetura baseada em entropia de mobilidade para ser integrada ao RPL que é posteriormente simulada extensivamente em um emulador para internet das coisas e redes de sensores sem fio. Esta arquitetura baseada em entropia de mobilidade considera o deslocamento dos nodos como fator de decisão para definir as rotas pelas quais os nodos transmitem e recebem pacotes. Os resultados experimentais mostram que a metodologia proposta pode ser eficaz e eficiente para reduzir perda de pacotes e latência em redes RPL com mobilidade.
162

Geração automática de código para redes de sensores sem fio usando Communicating X-machine

Braga, Marcus de Lima 05 January 2012 (has links)
Submitted by Divisão de Documentação/BC Biblioteca Central (ddbc@ufam.edu.br) on 2016-02-18T18:24:40Z No. of bitstreams: 1 Dissertação - Marcus de Lima Braga.pdf: 6450946 bytes, checksum: 146975a14889793868be80d04a6c46c5 (MD5) / Approved for entry into archive by Divisão de Documentação/BC Biblioteca Central (ddbc@ufam.edu.br) on 2016-02-18T19:37:05Z (GMT) No. of bitstreams: 1 Dissertação - Marcus de Lima Braga.pdf: 6450946 bytes, checksum: 146975a14889793868be80d04a6c46c5 (MD5) / Approved for entry into archive by Divisão de Documentação/BC Biblioteca Central (ddbc@ufam.edu.br) on 2016-02-18T19:39:18Z (GMT) No. of bitstreams: 1 Dissertação - Marcus de Lima Braga.pdf: 6450946 bytes, checksum: 146975a14889793868be80d04a6c46c5 (MD5) / Made available in DSpace on 2016-02-18T19:39:18Z (GMT). No. of bitstreams: 1 Dissertação - Marcus de Lima Braga.pdf: 6450946 bytes, checksum: 146975a14889793868be80d04a6c46c5 (MD5) Previous issue date: 2012-01-05 / Não informada / Wireless Sensor Network (WSN) has attracted the interest of researchers in applications development that operate on monitoring and control of physical phenomena, relying on its autonomy and exibility, and on its distributed nature and pervasive. If for one hand, this interest provides the development of new applications, on the other it increases its complexity and therefore costs. This is easily understood due their restrictive features, which make the crucial stages of software development (modeling, veri cation and testing) become a non-trivial task. The programming is carried out very close to the operating system (low level), favoring the distraction in the application of logic and thus requiring more concentration of the developer, as well as technical training, rare among experts. This scenario enables the creation of methodologies and tools that support development on this platform. This study aims to use the formal method called Communicating X-Machine in the construction of WSN applications, o ering an intuitive approach and a modular development, providing to the programmer a higher level of abstraction, making it easier to build applications until the code generation in nesC language programming (TinyOS platform). So, this paper aims to facilitate the development of applications, from their modeling until the code generation, providing to the developer an increase in the level of abstraction, a better understanding of the problem through its partitioning and ease of building WSN applications. / Rede de Sensores Sem Fio (RSSF) tem despertado o interesse de pesquisadores no desenvolvimento de aplicações que atuem no monitoramento e controle de fenômenos físicos, apoiando-se em sua autonomia e exibilidade, e em sua natureza distribuída e pervasiva. Se por um lado, esse interesse proporciona o desenvolvimento de novas aplica- ções, por outro, eleva sua complexidade e consequentemente seus custos. Isto é facilmente entendido devido suas características restritivas, que fazem com que os estágios cruciais do desenvolvimento de software (modelagem, veri cação e testes) se tornem tarefas não triviais. A programação é realizada muito próxima ao sistema operacional (baixo nível), favorecendo a distração na aplicação da lógica e exigindo, portanto, ao desenvolvedor maior concentração, além de formação técnica rara entre os especialistas. Este cenário propicia a criação de metodologias e ferramentas que deem suporte ao desenvolvimento nesta plataforma. Este trabalho tem por objetivo utilizar o método formal Communicating X-Machine na construção de aplicações RSSF, oferecendo uma abordagem intuitiva e um desenvolvimento modular, provendo ao programador elevação no nível de abstração, facilitando a construção de aplicações até a geração de código na linguagem de programa- ção nesC (plataforma TinyOS). Portanto, o presente trabalho pretende facilitar o desenvolvimento de aplicações, desde sua modelagem até a geração de código, proporcionando ao desenvolvedor o aumento no nível de abstração, melhor entendimento do problema através de seu particionamento e facilidade na construção de aplicações em RSSF.
163

Um sistema de alerta para o monitoramento remoto do consumo de energia usando redes de sensores sem fio / An alert for remote monitoring of energy consumption using wireless sensor networks

Geraldo Pereira Rocha Filho 06 June 2014 (has links)
Determinar quais são os aparelhos eletrônicos de uma residência que possuem maior influência na conta de luz não é tarefa trivial. As Redes de Sensores Sem Fios (RSSF) auxiliam os usuários nessa tarefa, permitindo descobrir se há algum tipo de desperdício no ambiente monitorado e assim, auxiliá-los a fazer as devidas correções. Por isso, é fundamental usar nas smart grids métodos que detectam novidades, também conhecido como anomalias , de forma individual e autônoma, para os usuários quando algo anômalo surge no consumo de energia dos equipamentos eletrônicos. Tais anomalias podem surgir, por exemplo, quando um equipamento consome energia acima do esperado, o que pode indicar um defeito. Nesse contexto, este trabalho propõe um método inteligente, nomeado como Novelty Detection Power Meter (NodePM), para detectar as novidades no consumo de energia dos equipamentos eletrônicos monitorados por uma smart grid. O NodePM detecta as novidades considerando a entropia de cada equipamento monitorado, a qual é calculada com base em um modelo de cadeia de markov que é gerado através de um algoritmo de aprendizado de máquina. Para tanto, o NodePM é integrado a uma plataforma de monitoramento remoto de consumo de energia, que consiste de uma RSSF associada a uma aplicação em nuvem. Para validar o desempenho do NodePM foram feitos experimentos utilizando a análise de variância e testes paramétricos e não-paramétricos. Os resultados de tais experimentos, obtidos mediante a análise estatística, evidenciou a viabilidade do NodePM na plataforma desenvolvida / It is not a simple task to determine which pieces of elevtronic equipment have the greatest influence on the electricity bill. The Wireless Sensor Networks (WSN) assist users in this task, allowing to discover if there is any type of a waste in a monitored environment and thus, help them to take proper actions. Hence, it is of crucial importance to use intelligent methods in the smart grids for a novelty detection and to inform the users in an individual and autonomous way when some anomaly has occurred in the energy consumption of electronic equipment. These anomalies can arise, for instance, when a piece of equipment consumes more energy than expected. In this context, we propose an intelligent method, named the Novelty Detection Power Meter (NodePM), to detect the novelties in the energy consumption of electonic equipment monitored by a smart grid. The NodePM detects the novelties considering the entropy of each device monitored, which is calculed based on a Markov chain model that is generated through a machine learning algorithm. For this end, the NodePM is integrated into a platform for the remote monitoring of energy consumption, which consists of a WSN associated with a cloud application. To validate the performance of the NodePM, experiments were done using analysis of variance and parametric and non-parametric tests. The result of these tests, which were obtained from a statistical analysis, provided evidence of the feasibility of the NodePM in the platform that was developed
164

Redes de sensores sem fio na coleta de dados fisiológicos de bovinos para aplicações na zootecnia de precisão / Wireless sensor networks technology applied to bovine physiological data acquisition for precision animal production

Aldo Ivan Céspedes Arce 22 February 2008 (has links)
Este trabalho mostra a aplicação das redes de sensores sem fio na monitoração de variáveis fisiológicas de bovinos. A necessidade de experimentar técnicas de coleta de dados, que causem menos perturbações no comportamento natural dos animais de interesse da zootecnia de precisão, foi a principal motivação deste trabalho. Para testar a aplicabilidade da tecnologia das redes de sensores sem fio neste campo, foi desenvolvida uma infra-estrutura, utilizando técnicas de instrumentação eletrônica e comunicação sem fio via rádio-freqüência. A rede foi projetada com o protocolo floating base sensor network (FBSN) que implementa uma topologia adhoc com escolha aleatória dos nós. Os protótipos desenvolvidos foram utilizados para efetuar coletas de sinais cerebrais e temperaturas corporais de bovinos adultos. Foram desenvolvidos também os softwares embarcados e de supervisão e um simulador de deslocamento bovino, que foi utilizado como ferramenta de auxílio no projeto da infra-estrutura de monitoramento implementada. O consumo das fontes de energia e a relação custo-beneficio do sistema foram os principais itens avaliados. Os resultados obtidos mostraram que é possível utilizar redes de sensores sem fio como técnicas eficientes para coleta de dados fisiológicos de bovinos. / This work presents an application of wireless sensor networks technology used for bovine physiological variables monitoring. The main stimulus of this work was the precision animal production researcher\'s interest in developing and testing new techniques that could allow data acquisition with less interference in animal behavior. In order to test the feasibility of the wireless sensor network technology in this area, an infrastructure was developed using electronic instrumentation and radio frequency wireless communication techniques. The network was projected to support the floating base sensor network protocol that is a special kind of adhoc topology with randomic selection of path nodes. The developed prototypes were used to acquire brain electrical activity and body temperature from bovines. The development of supervisor and embedded software and a bovine\'s displacement simulator tool was also described here. The energy consumption and the cost-benefit relationship of the network nodes were the main evaluated features. The results obtained prove that the wireless sensor networks can be considered as an efficient technique to be used to acquire bovine\'s physiological data.
165

Infraestrutura de rede de sensores sem fio para ambientes assistivos / Wireless sensor network infrastructure for assistive environments

Teixeira, Fábio Vieira, 1987- 24 August 2018 (has links)
Orientador: Eleri Cardozo / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Elétrica e de Computação / Made available in DSpace on 2018-08-24T14:20:11Z (GMT). No. of bitstreams: 1 Teixeira_FabioVieira_M.pdf: 4888310 bytes, checksum: 3976274cd7d3de15a58a9eec18e4aab5 (MD5) Previous issue date: 2013 / Resumo: Na última década, as redes de sensores sem fio foram alvo de várias pesquisa em diversas áreas, entre elas a Robótica Móvel e Ambientes Inteligentes. Com o uso dessa tecnologia é possível estender as capacidades de sensoriamento de robôs móveis para o ambiente em que se encontram, além de aumentar a abrangência da conectividade sem fio. Devido à grande exploração da área e o grande avanço das tecnologias CMOS, novos módulos de sensoriamento, como câmeras, puderam ser desenvolvidos e embarcados em transceptores de baixo custo. A interconexão dessas fontes compostas de múltiplas mídias deu origem a uma nova tecnologia, as Redes de Sensores Multimídia Sem Fio. Essas redes possibilitam o desenvolvimento de uma grande quantidade de aplicações que antes não eram possíveis apenas com o uso de sensores escalares, por exemplo, em áreas relacionadas ao controle de tráfego, vigilância, automação residencial e cuidados com a saúde. Esta dissertação explora o uso desta nova tecnologia para o desenvolvimento de uma infraestrutura capaz de prover serviços a robôs móveis semi-autônomos em ambientes instrumentados para acessibilidade, a fim de auxiliá-los no cumprimento de seus objetivos / Abstract: In the last decade, Wireless Sensor Networks have been the subject of research in many areas, including Mobile Robotics and Smart Environments. Such technology enables the extension of the mobile robots' sensing capabilities towards the environment where they are operating, as well as the increasing of the wireless connectivity coverage. Due to the large exploration of the area and the steady advance of CMOS technologies, new sensing modules such as cameras have being developed and embedded into low cost transceivers. The interconnection of multiple media sources raised a new technology known as Wireless Multimedia Sensor Networks. These networks allow the development of a wide range of applications that were not possible before using only scalar sensors, especially in areas related to traffic control, surveillance, home automation, and health care. This dissertation explores this new technology for the development of an infrastructure that provides services to semi-autonomous mobile robots in environments instrumented for accessibility, in order to assist the accomplishment of the robot's goals / Mestrado / Engenharia de Computação / Mestre em Engenharia Elétrica
166

Research and implementation of an indoor positioning algorithm

Liu, Honggang January 2017 (has links)
The goal of the Internet of Things’ sensing technology is to provide LBS(location-based services); a key technology is finding out how to positioning the sensing devices. For positioning outdoors, mature tech-nology such as GPS and cellular network location can be used. There is little research about indoor positioning, and there is no finished product on the market. This paper shows how to use both Wi-Fi and ZigBee signal for position-ing; Wi-Fi to find the area position and ZigBee to find the coordinate position. The main contribution of this paper is described in the follow-ing: This paper will present an algorithm using kNN on a Wi-Fi signal, as a way to find the location area of users. The GPS signal cannot be used indoors, but there are usually numerous Wi-Fi signals, that can be used for indoor positioning. In this design, to build a dataset containing the number of locations and the Wi-Fi signal strength list of each location. When indoor positioning is needed, the KNN algorithm is used to compare the user’s Wi-Fi signal strength with the dataset and find the location number. When precise positioning is needed, the ZigBee signal should be used. In this paper two different methods for precise positioning in are used, one is an improved algorithm of triangle centroid algorithm where the positioning accuracy depends on the number of anchor points and the interval of each point. The other method is the neural network method. This method could give stable result with only four anchor points. Finally, there is a comparison of the methods mentioned in this paper : the Wi-Fi fingerprint method, the ZigBee triangle centroid algorithm, and neural network method.
167

Enabling communication between border router and 6LoWPAN-based WSN for Healthcare

LI, XUEYUN January 2011 (has links)
No description available.
168

A Diagnostic Tool for the Causes of Packet Corruption in Wireless Sensor Networks

Jiang, Wenxuan January 2015 (has links)
The two main causes of packet corruption in wireless sensor network are multipath fading and WiFi interference. Identifying the cause of the corruption can be used to improve the reliability of the transmission. If the corruption is caused by WiFi interference, the network could change the channel to a free one. If it is caused by multipath fading, the network could reroute the traffic away from the obstacles or shorten the distance. This project proposes a new method of corruption-causes-identification for the two causes mentioned. It is an immediate online diagnostic tool for IEEE 802.15.4 packets with a retransmission mechanism. It provides a statistical boundary with a processed deviation of RSSI value and the frame symbol error rate, and also a rechecking mechanism to check the decisions. In this model, the deviation of RSSI value is measured by the estimated RSSI value of correct packets and the current detected RSSI value. The benefit of the deviation design is that the statistical model hardly needs to retrain and correct the parameters in different transmission environments. The project also discusses two rechecking mechanism methods, one employs an individual secondary classification with its own characters; the other combines the neighbor packets' features to smooththe probable errors. To investigate the performance of the "frame symbol errorrate and deviation of RSSI values"-based diagnostic tool, the evaluation parts provide a comparison of different length packets. The conclusion is that this diagnostic tool provides a correct judgment of the accuracy of packet corruption caused by multipath fading up to 98.70%, and an accuracy of up to 92.99% for the WiFi-interferenced packet corruption.
169

Ubiquitous healthcare system based on a wireless sensor network

Chung, W.-Y. (Wan-Young) 17 November 2009 (has links)
Abstract This dissertation aimed at developing a multi-modal sensing u-healthcare system (MSUS), which reflects the unique properties of a healthcare application in a wireless sensor network. Together with health parameters, such as ECG, SpO2 and blood pressure, the system also transfers context-aware data, including activity, position and tracking data, in a wireless sensor network environment at home or in a hospital. Since packet loss may have fatal consequences for patients, health-related data are more critical than most other types of monitoring data. Thus, compared to environmental, agricultural or industrial monitoring, healthcare monitoring in a wireless environment imposes different requirements and priorities. These include heavy data traffic with wavelike parameters in wireless sensor network and fatal data loss due to the traffic. To ensure reliable data transfer in a wireless sensor network, this research placed special emphasis on the optimization of sampling rate, packet length and transmission rate, and on the traffic reduction method. To improve the reliability and accuracy of diagnosis, the u-healthcare system also collects context-aware information on the user’s activity and location and provides real-time tracking. Waveform health parameters, such as ECG, are normally sampled in the 100 to 400 Hz range according to the monitoring purpose. This type of waveform data may incur a heavy burden in wireless communication. To reduce wireless traffic between the sensor nodes and the gateway node, the system utilizes on-site ECG analysis implemented on the sensor nodes as well as query architecture. A 3D VRML viewer was also developed for the realistic monitoring of the user’s moving path and location. Two communication methods, an 802.15.4-based wireless sensor network and a CDMA cellular network are used by sensors placed on the users’ bodies to gather medical data, which is then transmitted to a server PC at home or in the hospital, depending on whether the sensor is within or outside the range of the wireless sensor network.
170

A trust-based adaptive access control model for wireless sensor networks

Maw, Htoo Aung January 2015 (has links)
Wireless Sensor Networks (WSNs) have recently attracted much interest in the research community because of their wide range of applications. One emerging application for WSNs involves their use in healthcare where they are generally termed Wireless Medical Sensor Networks (WMSNs). In a hospital, fitting patients with tiny, wearable, wireless vital sign sensors would allow doctors, nurses and others to continuously monitor the state of those in their care. In the healthcare industry, patients are expected to be treated in reasonable time and any loss in data availability can result in further decline in the patient's condition or can even lead to death. Therefore, the availability of data is more important than security concerns. The overwhelming priority is to take care of the patient, but the privacy and confidentiality of that patient's medical records cannot be neglected. In current healthcare applications, there are many problems concerning security policy violations such as unauthorised denial of use, unauthorised information modification and unauthorised information release of medical data in the real world environment. Current WSN access control models used the traditional Role-Based Access Control (RBAC) or cryptographic methods for data access control but the systems still need to predefine attributes, roles and policies before deployment. It is, however, difficult to determine in advance all the possible needs for access in real world applications because there may be unanticipated situations at any time. This research proceeds to study possible approaches to address the above issues and to develop a new access control model to fill the gaps in work done by the WSN research community. Firstly, the adaptive access control model is proposed and developed based on the concept of discretionary overriding to address the data availability issue. In the healthcare industry, there are many problems concerning unauthorised information release. So, we extended the adaptive access control model with a prevention and detection mechanism to detect security policy violations, and added the concept of obligation to take a course of action when a restricted access is granted or denied. However, this approach does not consider privacy of patients' information because data availability is prioritised. To address the conflict between data availability and data privacy, this research proposed the Trust-based Adaptive Access Control (TBA2C) model that integrates the concept of trust into the previous model. A simple user behaviour trust model is developed to calculate the behaviour trust value which measures the trustworthiness of the users and that is used as one of the defined thresholds to override access policy for data availability purpose, but the framework of the TBA2C model can be adapted with other trust models in the research community. The trust model can also protect data privacy because only a user who satisfies the relevant trust threshold can get restricted access in emergency and unanticipated situations. Moreover, the introduction of trust values in the enforcement of authorisation decisions can detect abnormal data access even from authorised users. Ponder2 is used to develop the TBA2C model gradually, starting from a simple access control model to the full TBA2C. In Ponder2, a Self-Managed Cell (SMC) simulates a sensor node with the TBA2C engine inside it. Additionally, to enable a full comparison with the proposed TBA2C model, the Break-The-Glass Role Based Access Control (BTGRBAC) model is redesigned and developed in the same platform (Ponder2). The proposed TBA2C model is the first to realise a flexible access control engine and to address the conflict between data availability and data privacy by combining the concepts of discretionary overriding, the user behaviour trust model, and the prevention and detection mechanism.

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