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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.
341

Implementation of Bluetooth Baseband Behavioral Model in C Language

Kuo, Ying-Chi January 2005 (has links)
This master thesis is as a final project in the Division of Computer Engineering at the Department of Electrical of Engineering, Linköping University, Sweden. The purpose of the project is to set up a baseband behavioral model for a Bluetooth system based on standards. In the model, synchronization in demodulation part has been focused on. Simulation results are analyzed later in the report to see how the method in demodulation works. Some suggestions and future works for receiver are provided to improve the performances of the model.
342

Cascading Web Services in Mobile Environments : Bridging Wireless and Wired Networks for Data Transactions

Kajtazi, Miranda, Vogel, Bahtijar January 2007 (has links)
Cascading Web Services represent a collection of services offered in a system consisting of multiple devices and multiple interacting platform independent networks. ‘Cascading’ enables Web Services to exploit access in diverse environments without manual intervention. The aim of this thesis is to investigate how Mobile Web Services interact with multiple other Web Services by allowing the generated content to cascade. These services are demonstrated as a technical design solution, in a number of cases within the field of Learning technologies. Communication among devices is preceded using request-response commands by cascading these commands between different Web Services that are self-contained and independent on their context or state. The system signifies a typical Service Oriented Architecture (SOA) based on a distributed system. Cascading Web Services involve multiple transport networks including Bluetooth Technology, GPRS, Wi-Fi, and Wired Networks. Whereas the protocol of this communication is to bridge Wired and Wireless networks for data transactions, specifically from a Bluetooth location-based network. A number of particular cases will be illustrated in the context of ‘educational outdoor activities’, to demonstrate how the system solution works involving users.
343

Estudo da taxa de absorção específica e análise de dosimetria em protótipos de óculos e fone de ouvido para dispositivos de comunicação operando próximo da cabeça do usuário

Álvarez Pizarro, Yuli Andrea January 2015 (has links)
Dois dispositivos de comunicação sem fio populares são considerados nesta pesquisa. Em primeiro lugar, o fone de ouvido que utiliza tecnologia Bluetooth, sendo um dos acessórios móveis mais econômicos do mercado e os óculos para dispositivos de comunicação que são uma representação da nova visão futurista. A absorção de ondas eletromagnéticas na cabeça humana durante um certo período de tempo, pode conduzir a problemas de saúde. A Taxa de Absorção Específica (SAR) foi simulada em quatro modelos diferentes para duas abordagens que realizam variações nos parâmetros dielétricos dos tecidos da cabeça. Estes resultados foram comparados com as recomendações internacionais (IEC 62209-2, 2010; ICNIRP, 2009; IEEE C95.1,2005; WHO, 2006; IEEE, 2002). O primeiro modelo utilizado foi o Manequim Antropomórfico Específico (SAM phantom), bem como três modelos realistas de cabeça humana (ou seja, um adulto de 34 anos e duas crianças de 10 e 6 anos). As simulações foram executadas utilizando o método de diferenças finitas (FDTD) e a frequência usada para alimentar as antenas foi de 2,45 GHz. Além disso foram feitas medidas experimentais de potência transmitida pelo dispositivo Bluetooth. / Two popular wireless communication devices are considered in this research. Firstly, the handset Bluetooth which is one of the most economic mobile accessories and the eyewear Communicating Device which are a representation of the new futuristic vision. It is well known that the absorption of electromagnetic waves on the human head for a certain period of time may lead to health problems such as headaches. The Specific Absorption Rate (SAR) is simulated to four different head models for two approaches that perform variations in the dielectric parameters in the head tissues and compared with the available international recommendations (IEC 62209-2, 2010; ICNIRP, 2009; IEEE C95.1,2005; WHO, 2006; IEEE, 2002). The first model used is the Specific Anthropomorphic Mannequin (SAM phantom), as well as three realistic models of human head (i.e., a 34 years old adult and two children of 10 and 6 years old). The simulations were performed using the finite difference time domain (FDTD) method and the frequency used to feed the antennas was 2.45 GHz. Experimental measurements of transmission power in Bluetooth device are also described.
344

Sistema digital de instrumentação sem fio de uma mola Helicoidal TI-NI usando tecnologia zigbee, usb e linux

de Santana Bezerra Ramos, Jadeilson 31 January 2010 (has links)
Made available in DSpace on 2014-06-12T17:35:16Z (GMT). No. of bitstreams: 2 arquivo2009_1.pdf: 3503480 bytes, checksum: 85d90aa1952ca122f373c0f061692038 (MD5) license.txt: 1748 bytes, checksum: 8a4605be74aa9ea9d79846c1fba20a33 (MD5) Previous issue date: 2010 / Conselho Nacional de Desenvolvimento Científico e Tecnológico / O padrão zigbee foi utilizado na instrumentação de molas helicoidais de Ti-Ni utilizando, assim, a porta USB para comunicação de dados sem fio com o laptop e a mola utilizando a plataforma operacional Linux. Um estudo do comportamento da tensão elétrica da mola Ti-Ni sob a variação da corrente elétrica e distensão mecânica foi feito. Foi observado que para condições normais de temperatura e ambiente, o sistema apresentou variação linear na faixa analisada. E que uma análise estatística para uma faixa de operação de corrente e comprimentos constantes, a mola apresentou condições suficientes para a instrumentação. Foram desenvolvidos programas para que as tecnologias zigbee, microcontrolador, PIC16F877A e USB pudessem se comunicar entre si. A implementação do algoritmo sugerido mostrou-se, ao longo dos testes, um desempenho positivo. Uma análise do erro que o sistema de instrumentação sem fio poderia introduzir no monitoramento foi feita. Com isso, constatou-se que o erro absoluto do mesmo não apresentou nenhuma influência no monitoramento da distensão mecânica da mola. Os resultados mostraram-se favoráveis ao objetivo da dissertação e foi verificado que o monitoramento sem fio de distensão mecânica da mola Ti-Ni apresentou confiabilidade considerável
345

Proposta de um sistema computacional para verificação do estado de funcionamento de escadas rolantes à distância / Proposal of a computer system for verification of the state of operation of escalators at the distance

Paulo Rogério da Silva 29 November 2008 (has links)
O objetivo do presente trabalho é apresentar uma proposta de sistema computacional para verificação do estado de funcionamento de escadas rolantes por meio de comunicação sem fio. O sistema computacional proposto neste trabalho é composto de uma interface instalada diretamente no painel de controle da escada rolante com o objetivo de coletar informações que permitam identificar o estado de funcionamento desses equipamentos e transmiti-las para um computador remoto por meio de uma estrutura de rede sem fio construída sob o padrão Bluetooth. O sistema proposto possibilita que a inspeção periódica do estado de funcionamento seja feita sem a interrupção do serviço ao público, a qual ocorre somente quando a leitura de dados informar alguma não conformidade ou em períodos pré-estabelecidos pelo fabricante, para troca de peças por fadiga. Dessa forma, possibilita-se um ganho de qualidade e produtividade das equipes de manutenção, as quais poderão realizar uma quantidade maior de inspeções com menor tempo de execução do trabalho e um aumento do tempo de disponibilidade das escadas rolantes aos usuários. O presente trabalho apresenta a arquitetura básica de hardware e software desenvolvidos e discute questões de segurança e confiabilidade do sistema proposto, os ganhos de produtividade para as equipes de manutenção, bem como o aumento do tempo de disponibilidade dos serviços prestados por escadas e esteiras rolantes frente a indicadores mundiais de qualidade de serviço. / The objective of the present work is to present a proposal of computer system for verification of the state of operation of escalator through communication without thread. The computer system proposed in this work it is composed of an interface installed directly in the panel of control of the escalator with the objective of collecting information that allow to identify the state of operation of those equipments and to transmit them for a remote computer through a net structure without thread built under the pattern Bluetooth. The proposed system makes possible that the periodic inspection of the operation state is made without the interruption of the service to the public, which only happens when the reading of data informs some non conformity or in periods established by the manufacturer, for change of pieces for fatigue. In that way, it is made possible a quality earnings and productivity of the maintenance teams, which can accomplish a larger amount of inspections with smaller time of execution of the work and an increase of the time of readiness of the escalator to the users. The present work presents the basic architecture of hardware and software developed and it discusses subjects of safety and reliability of the proposed system, the productivity earnings for the maintenance teams, as well as the increase of the time of readiness of the services rendered by escalator front to world indicators of service quality.
346

Finding Social Location Using Bluetooth

Hayat, Umer January 2009 (has links)
From the last few years many location based system have been introduced e.g. facebook, orkut, youtube and my-space etc. These networks are specially developed for personal computers. Some location based systems are also introduced for mobile device e.g. Plazes, MamJam, Slam and Jambo. All these type of networks are using the concept of social location, which provides the platform where people can join or make communities according to their interests. Numbers of users on these networks are increasing day by day due to their popularity. This popularity gives the opportunity for researchers to explore the characteristics of these social networks at large scale. This knowledge will be then used to improve the existing networks or to develop new networks. Already developed systems for mobile devices are using different techniques (e.g. Radio Frequency Identification, GPS, GSM, WAP etc.) to determine the location of any person. In this thesis, I am going to develop a prototype of system that will find the social location of an individual using passive Bluetooth scanning of mobile devices. The main idea behind this prototype is that the data obtained should be flexible to target different social needs and as well as different social location applications. The research will explore some more areas of Bluetooth by extending its dimension in social location system. The expected output from this research will help human being to overcome some of their social problems. Social location obtained from the prototype can be used to fulfill different social needs of human being. Keywords: Social location, Bluetooth, Physical location, GPRS, Mobile applications.
347

WOSP : Wireless Open Source Platform

Karlsson, Andreas January 2001 (has links)
The hot spot in the market of embedded systems today are opening up the systems so the world around can communicate with it. The idea of this Master Thesis is to show a way to wirelessly open up an embedded system to the world. The goal of the project is to build a prototype for machine-to-machine applications. This project clarifies the practical issues that rise when the idea is implemented. In this project an embedded WAP-server has been developed. All software components used are open source even the development environment. This means that there will be no license costs at all. The server runs on top of Axis? Bluetooth communication stack. The operating system used is eCos, which is open source and shipped by Red Hat. The system runs on an evaluation board equipped with an ARM7 processor, 256 KB RAM and 256 KB ROM. The report can be found at http://www.combitechsystems.com/node2866.asp
348

Beacone : En ny BLE beacon med Wi-Fi-stöd för uppdatering av URL / Beacone : A new BLE Beacon with Wi-Fi support for URL update

Fryxelius, Jonathan, Runeson, Johannes January 2017 (has links)
Ända sedan radion uppfanns har trådlös kommunikation varit ett mål för modern teknologi. Trots över 100 års teknologisk utveckling är radiosignaler högst relevanta, och används idag både för traditionell enkelriktad radiosändning, men också som grund för Bluetoothteknologin, som stöds av allt från bilar till telefoner och högtalare. Den här avhandlingen beskriver framtagandet av en speciell typ av Bluetoothsändare, så kallad beacon, som dessutom tillämpar trådlös nätverksanslutning för att utvidga beacons klassiska funktionalitet och ge nya möjligheter. Den nya produkten kallas Beacone. Som stöd för dess funktionalitet utvecklas ett webbgränssnitt och en mobilapplikation. Resultatet utvärderas och möjliga förbättringar diskuteras. Arbetet visar att det under flera omständigheter finns fördelar med en nätverksansluten beacon, som tillhandahåller möjligheter som inte annars hade funnits. / Ever since the invention of the radio, wireless communication has been the goal for modern technology. Despite 100 years of technological development, radio waves remain highly relevant, and are today used both in traditional one-way radio transmission, but also as the foundation for Bluetooth technology, which is supported by cars, phones, speakers, and everything in between. This report describes the development of a special Bluetooth transmitter, a so-called beacon, which also features wireless network connection to expand the traditional functionality of beacons and yield new opportunities. The new product is named Beacone. Supportive software, such as a web interface and a mobile cellphone application, is also developed. The result is evaluated, and possible improvements are discussed. The work shows that there are circumstances where Wi-Fi connectivity provides benefits which would not be available without it.
349

Evaluation of Wireless Techniques for Short-Range Communication / Utvärdering av trådlösa tekniker för kommunikation över korta avstånd

Söderkvist, Jonas January 2003 (has links)
On radar level gauges currently shipped by Saab Rosemount, some adjustments of the unit's parameters has to be performed in the field. Presently, this is a cumbersome procedure; the operator has to be very close to the gauge and he either has to carry with him a bulky configuration unit or use a basic control unit on the gauge. A wireless solution, where a portable device and a receiver replace the control unit, would both allow the operator to work from a distance and eliminate the need for the bulky device. The most conspicuous restraint for such a solution is a very low allowed power dissipation. The reason for this is that some gauges do not have a separate power supply, but are fed directly off the communication bus. A viable solution should also be commercially available and robust enough to operate in an industrial environment. To meet these requirements both a theoretical and a practical assessment was conducted, where the two techniques for wireless communication, IrDA, and Bluetooth, was given special consideration. As for the portable device, the market for hand-held computers was investigated and ultimately a PDA from Palm was selected for this project. Together with this PDA, a prototype for each of the two wireless techniques was tested to ascertain their performance with respect to power dissipation, communication range, and communication robustness. This investigation revealed that Bluetooth could be used over a much greater distance than IrDA and it did also provide a more robust solution overall. IrDA is nonetheless also a competent technique, and has its primary advantage in terms of much lower power dissipation compared to Bluetooth.
350

Bluetooth Enhanced Data Rate Baseband Modeling and Implementation

Zou, Lei January 2006 (has links)
The main issue of this thesis is making the behaviour model of Bluetooth EDR (enhanced data rate) baseband signal processing. This Bluetooth baseband project is part of the soft defined radio project at electrical engineering department, Linköping University. In this project, both the basic rate and EDR model were built and simulated. The GFSK and π/4 DQPSK digital modulation and demodulation were implemented in C code. The BER was tested to evaluate the demodulation results. Furthermore, the error correction (FEC) and the error checking (HEC,CRC) were also implemented according to the Bluetooth standards. The CRC flag was detected to test the payload demodulation results. Especially, GFSK and π/4 DQPSK specifications have to be combined with each other at sample rate of ADC. Finally, the basic rate and EDR model were simulated to measure the BER and CRC performance. From the simulation results, the receiver filter, synchronization and channel condition were three key points in this Bluetooth EDR system implementation. So we get further understanding about the Bluetooth system specification and DSP implementation methods.

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