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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.
1

Clock synchronization and dominating set construction in ad hoc wireless networks

Zhou, Dong, January 2005 (has links)
Thesis (Ph. D.)--Ohio State University, 2005. / Title from first page of PDF file. Includes bibliographical references (p. 145-149).
2

High-accuracy Acoustic Sensing System with A 2D Transceiver Array: An FPGA-based Design

Zhengxin Jiang (18126316) 08 March 2024 (has links)
<p dir="ltr">The design of hardware platform in acoustic sensing is critical. The number and the spatial arrangement of microphones play a huge role in sensing performance. All microphones should be properly processed for simultaneous recording. This work introduces an FPGA-based acoustic transceiver system supporting acoustic sensing with custom acoustic signals. The system contains 16 microphones and a speaker synchronized during sensing processes. The microphones were arranged into an ‘L’ shape with eight microphones on each line for a better resolution of angle estimation on two dimensions. The microphones were placed on a specifically designed PCB to achieve an optimal distance of the half-wavelength of acoustic signals for optimized sensing performance. A microphone interface was implemented on Ultra96-V2 FPGA for handling the simultaneous high-speed data streams. The system features an implementation of full-level data transmission up to the top-level Python program. To evaluate the sensing performance of the system, we conducted an experiment used Frequency Modulated Continuous Wave (FMCW) as the transmitted acoustic signal. The result of evaluation shown the accurate sensing of range, velocity and relative angle of a moving hand on the two dimensions corresponding to the microphone groups.</p>
3

Desenvolvimento de um demodulador digital e de um ambiente de simulaçao para sistema de telemedidas / Development of a digital demodulator and a simulation environment for a telemetry system

Okajima, Henri Shinichi de Souza 16 August 2018 (has links)
Orientador: Luís Geraldo Pedroso Meloni / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Elétrica e de Computação / Made available in DSpace on 2018-08-16T06:39:32Z (GMT). No. of bitstreams: 1 Okajima_HenriShinichideSouza_M.pdf: 2252019 bytes, checksum: df6b064fa2391bdd5665b43e140c56b1 (MD5) Previous issue date: 2010 / Resumo: Esta dissertação apresenta os resultados obtidos com a pesquisa e implementação de um sistema de demodulação para o receptor de rastreio de um radar de telemedidas. Um radar de telemedidas é responsável pela identificação de um conjunto de medidas realizadas no objeto espacial e enviadas para a antena através de um transponder. A antena de telemedidas deve rastrear o objeto, mantendo-se sempre apontada na direção deste. Para realizar esta função foi utilizada a técnica de monopulso de um canal. Na técnica de monopulso de um canal, cabe ao demodulador digital do receptor executar uma identificação de envoltória e uma demultiplexação temporal que deve permitir encontrar os valores angulares dos erros. A implementação resultou em uma placa de demodulador digital, realizada com um Field Programmable Gate Array (FPGA) da família Cyclone II, e um controlador Freescale, embarcados em uma Placa de Circuito Impresso (PCI) de quatro camadas, projetada para interfacear sinais digitais para controle do sistema de telemedidas e para condicionar os sinais analógicos para posterior processamento. Além de ter interface com placas específicas (por exemplo, CAF - Controle automático de freqüência, CAG - controle automático de ganho, Gerador de Teste, etc), possui também uma interface Controller Area Network (CAN) para comunicação com os módulos de controle de servomecanismos da antena e de interface usuário. Foi desenvolvido também um ambiente de simulação para o demodulador digital em Matlab permitindo verificar a coerência com os resultados esperados e traçar cenários de testes / Abstract: This project presents the results obtained by the research and development of a Demodulation System for a telemetry radar tracking receiver. A telemetry radar system is responsible for identifying a set of measures taken from a spatial artifact and is transmitted by a transponder to its antenna. The telemetry antenna must track the spatial object, maintaining the antenna pointing in the correct direction. To execute this function a single channel monopulse technique is applied. Since the single channel monopulse technique is used, a digital demodulator task is then run for amplitude identification and the de-multiplexing time frame must occur in order to calculate the angle values of errors. This process is explained during the dissertation after the presentation of the main characteristics of radars and some aspects of telemetry systems. The solution is a digital demodulator electronic board, build with an FPGA (Field Programmable Gate Array) from Altera Cyclone II® family, and a Freescale® controller, over a multilayer PCB (Printed Circuit Board) projected to interface with digital signals for the Telemetry Control System and to conditioning analogical signals for processing tasks. The developed board has the CAN (Controller Area Network) interface to communicate with the servomechanism control modules associated with the Antenna and is placed in an armored drawer - to avoid electromagnetic noises - as well as to interact with other specific board functions.A simulation environment was achieved for the digital demodulator in Matlab, allowing the results verification and allowing to establish others testing scenarios / Mestrado / Telecomunicações e Telemática / Mestre em Engenharia Elétrica
4

<b>RIVER RESTORATION INTELLIGENCE AND VERIFICATION (RRIV): DEVELOPMENT OF A LOW-COST, VERSATILE EMBEDDED SYSTEM FOR BROAD-SCALE MONITORING OF WATER QUALITY AND GREENHOUSE GAS EMISSIONS</b>

Ken Yao Chong (16805982) 09 August 2023 (has links)
<p>Sensor technology is evolving rapidly, offering new opportunities for environmental data collection. Yet, despite the large number of sensors now available, there is a lack of logging platforms that can be used to operate these sensors in situ. To address this shortfall, River Restoration Intelligence and Verification (RRIV) has developed an environmental data logger that meets the needs of the environmental sensing community. This platform has several advantages that reduce the time, effort, and technical know-how required to deploy environmental sensors. An extensive low-power mode is available, and hardware such as a real-time clock with an independent power source is incorporated. A driver system has been developed that allows users to incorporate sensors into the platform with minimal effort. RRIV loggers also include a command line interface that allows user to add or remove sensors, calibrate sensors, or configure deployments without the need for C/C++ programming, something that is not possible with out-of-the-box microcontrollers such as Arduino and ST Nucleo products. The technology incorporated into RRIV and how it is applied and deployed in the field is described. This includes a description of power consumption. Protocols and descriptions of case construction are also included. RRIV loggers configured to monitor carbon dioxide and methane are used to demonstrate how this platform is used in the field.</p>
5

Hardware Implementation of Learning-Based Camera ISP for Low-Light Applications

Preston Rashad Rahim (17676693) 20 December 2023 (has links)
<p dir="ltr">A camera's image signal processor (ISP) is responsible for taking the mosaiced and noisy image signal from the image sensor and processing it such a way that an end-result image is produced that is informative and accurately captures the scene. Real-time video capture in photon-limited environments remains a challenge for many ISP's today. In these conditions, the image signal is dominated by the photon shot noise. Deep learning methods show promise in extracting the underlying image signal from the noise, but modern AI-based ISPs are too computationally complex to be realized as a fast and efficient hardware ISP. An ISP algorithm, BLADE2 has been designed, which leverages AI in a computationally conservative manner to demosaic and denoise low-light images. The original implementation of this algorihtm is in Python/PyTorch. This Thesis explores taking BLADE2 and implementing it on a general purpose GPU via a suite of Nvidia optimization toolkits, as well as a low-level implementation in C/C++, bringing the algorithm closer to FPGA realization. The GPU implementation demonstrated significant throughput gains and the C/C++ implementation demonstrated the feasibility of further hardware development.</p>
6

Methods for protecting intellectual property of IP cores designers / Méthodes pour la protection de la propriété intellectuelle des concepteurs de composants virtuels

Colombier, Brice 19 October 2017 (has links)
La conception de circuits intégrés est aujourd'hui une tâche extrêmement complexe. Cela pousse les concepteurs à adopter une approche modulaire, où chaque bloc fonctionnel est décrit de manière indépendante. Ces blocs fonctionnels, appelés composants virtuels, sont vendus par leurs concepteurs à des intégrateurs système qui les utilisent dans des projets complexes. Cette division a pour conséquence une hausse inquiétante des cas de copie illégale des composants virtuels. Afin de lutter contre cette menace sur la propriété intellectuelle des concepteurs, l'objectif de cette thèse était de mettre au point un système complet d'activation à distance de composants virtuels, permettant au concepteur de savoir exactement combien de composants virtuels sont effectivement utilisés. Pour cela, les deux premières contributions de cette thèse portent sur la modification de la logique combinatoire d'un composant virtuel afin de le rendre activable. La première méthode permet de forcer les sorties à une valeur fixe de manière contrôlée. La seconde est une technique efficace de sélection de nœuds à altérer, encore une fois de manière contrôlée, afin de rendre le composant virtuel temporairement inutilisable. La troisième contribution de cette thèse est une méthode légère de correction d'erreurs à appliquer aux réponses issues des fonctions physiques non-clonables, qui constituent un identifiant intrinsèque des instances du composant virtuel. Réutilisant un protocole de correction d'erreurs issu de l'échange quantique de dés, cette méthode est beaucoup plus légère que les codes correcteurs d'erreurs classiquement utilisés pour cette application / Designing integrated circuits is now an extremely complex task. This is why designers adopt a modular approach, where each functional block is described independently. These functional blocks, called intellectual property (IP) cores, are sold by their designers to system integrators who use them in complex projects. This division led to the rise of cases of illegal copying of IP cores. In order to fight this threat against intellectual property of lP core designers, the objective of this PhD thesis was to develop a secure remote activation scheme for IP cores, allowing the designer to know exactly how many IP cores are currently used. To achieve this, the first two contributions of thesis thesis deal with the modification of combinational logic of an IP core to make it activable. The first method allows to controllably force the outputs to a fixed logic value. The second is an efficient technique to select the nodes to controllably alter, so that the IP core is temporarily unusable. The third contribution of this thesis is a lightweight method of error correction to use with PUF (Physical Undonable Functions) responses, which are an intrinsic identifier of instances of the lP core. Reusing an error-correction protocol used in quantum key ex.change, this method is much more lightweight than error-correcting
7

Introduction des techniques numériques pour les capteurs magnétiques GMI (Giant Magneto-Impedance) à haute sensibilité : mise en œuvre et performances / Introduction of digital techniques for high sensitivity GMI (Giant Magneto-Impedance) magnetic sensors : implementation and performances

Traore, Papa Silly 19 October 2017 (has links)
La Magneto-Impédance Géante (GMI) consiste en une forte variation de l’impédance d’un matériau ferromagnétique doux parcouru par un courant d’excitation alternatif haute fréquence lorsqu’il est soumis à un champ magnétique extérieur. Ce travail de thèse introduit de nouvelles techniques numériques et les pistes d’optimisation associées pour les capteurs GMI à haute sensibilité. L'originalité réside dans l'intégration d'un synthétiseur de fréquence et d'un récepteur entièrement numérique pilotés par un processeur de traitement de signal. Ce choix instrumental se justifie par le souhait de réduire le bruit de l’électronique de conditionnement qui limite le niveau de bruit équivalent en champ. Ce dernier caractérise le plus petit champ mesurable par le capteur. Le système de conditionnement conçu est associé à la configuration magnétique off-diagonal pour accroître la sensibilité intrinsèque de l’élément sensible. Cette configuration magnétique consiste en l’utilisation d’une bobine de détection autour du matériau ferromagnétique. Cette association permet en outre d’obtenir une caractéristique impaire de la réponse du capteur autour du champ nul, et par conséquent de pouvoir mettre en œuvre et d’utiliser le capteur sans avoir recours à une polarisation magnétique. Ce choix permet ainsi d’éliminer, ou au moins de minimiser les problématiques liées aux offsets des dispositifs GMI, tout en validant l’intérêt de cette configuration magnétique, notamment sur le choix du point de fonctionnement. Une modélisation des performances en bruit de toute la chaîne de mesure, incluant le système de conditionnement numérique, est réalisée. Une comparaison entre les niveaux de bruit équivalent en champ attendus par le modèle et mesurés est effectuée. Les résultats obtenus ont permis de dégager des lois générales d’optimisation des performances pour un capteur GMI numérique. Partant de ces pistes d’optimisation, un prototype de capteur complet et optimisé a été implémenté sur FPGA. Ce capteur affiche un niveau de bruit équivalent en champ de l’ordre de 1 pT/√Hz en zone de bruit blanc. En outre, ce travail permet de valider l’intérêt des techniques numériques dans la réalisation de dispositifs de mesure à haute sensibilité. / The Giant Magneto-Impedance (GMI) is a large change of the impedance of some soft ferromagnetic materials, supplied by an alternating high-frequency excitation current, when they are submitted to an external magnetic field. This thesis presents the design and performance of an original digital architecture for high-sensitivity GMI sensors. The core of the design is a Digital Signal Processor (DSP) which controls two other key elements: a Direct Digital Synthesizer (DDS) and a Software Defined Radio (SDR) or digital receiver. The choice of these digital concepts is justified by the will to reduce the conditioning electronics noise that limits the equivalent magnetic noise level. The latter characterizes the smallest measurable field by the sensor. The developed conditioning system is associated with the off-diagonal magnetic configuration in order to increase the intrinsic sensitivity of the sensitive element. This magnetic configuration consists of the use of an additional a pick-up coil wound around the ferromagnetic material. This association also makes it possible to obtain an asymmetrical characteristic (odd function) of the sensor response near the zero-field point and to consequently allow for sensor implementation and use without any bias magnetic field. Thus, this choice eliminates, or at least minimizes, the problems related to the offset cancelling of the GMI devices. Also, it validates the advantage of this magnetic configuration, especially the choice of the operating point. Modeling of the noise performance of the entire measurement chain, including the digital conditioning, is performed. A comparison between the expected and measured equivalent magnetic noise levels is then carried out. The results yield general optimization laws for a digital GMI sensor. Using these laws, an optimized prototype of a GMI sensor is designed and implemented on FPGA. An equivalent magnetic noise level in a white noise zone region of approximately 1 pT/√ Hz is obtained. Furthermore, this work also makes it possible to validate the interest of digital techniques in the realization of a high-sensitivity measuring devices.
8

Sistema para controle de maquinas robotizadas utilizando dispositivos logicos programaveis / System to control of robotic machines using programmable logic devices

Guardia Filho, Luiz Eduardo 07 June 2005 (has links)
Orientador: Marconi Kolm Madrid / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Eletrica e de Computação / Made available in DSpace on 2018-08-04T17:12:57Z (GMT). No. of bitstreams: 1 GuardiaFilho_LuizEduardo_M.pdf: 2405031 bytes, checksum: b724836217b8586950a9ffabcd235f35 (MD5) Previous issue date: 2005 / Resumo: Este trabalho de mestrado teve o propósito de projetar e construir um sistema de hard-ware capaz de realizar o controle de máquinas robotizadas em tempo real. Foi dada uma abordagem usando técnicas de processamento paralelo e eletrônica reconfigurável com o uso de dispositivos lógicos programáveis. Mostrou-se em função dos resultados das implementações que o sistema proposto é eficiente para ser utilizado no controle de robôs baseado em modelos matemáticos complexos como cinemático direto/inverso, dinâmico e de visão artificial. Esse mesmo sistema prevê sua utilização para os quatro níveis hierárquicos envolvidos em plantas que se utilizam de controle automático: supervisão, tarefas, trajetória e servomecanismos. O sistema possui interfaces de comunicação USE e RS-232, conversores A/D e D/A, sistema de processamento de imagens (entradas e saídas de sinais de vídeo analógico), portas E/S, chaves e leds para propósito geral. A eficiência foi comprovada através de experimentações práticas utilizando sistemas robóticos reais como: sistema de um pêndulo acionado, robô redundante de 4GDL denominado Cobra, e solução em hardware de funções importantes no sentido da resolução dos modelos matemáticos em tempo real como funções transcendentais / Abstract: This work had as purpose the project and build of a hardware system with abilities to accomplish the real time control of robotic machines. It was given an approach using tech-niques of parallel processing and programmable electronics configuration with programmable logic devices. According to the implementation results, it was shown that this proposed sys-tem is efficient to be used for controlling robots based on complex mathematical models, like direct/inverse kinematics, dynamics and artificial vision. This system foresees its use for the four hierarchical levels involved in industrial plants that use automatic control: supervision, tasks, trajectory /path and servomechanisms. The system has USE and RS-232 communica-tion interfaces, A/D and D/A converters, image processing capabilities (with input/output for analog video signals), I/O ports, and switches and leds for general purpose. Its efficiency is demonstrated through practical experimentations using real robotic systems as: a driven pendu-lum system, a redundant 4 DOF robot called "Cobra", and a hardware solution for important functions in the sense of real time mathematical models computing, like the transcendental functions / Mestrado / Automação / Mestre em Engenharia Elétrica
9

ENERGY-EFFICIENT SENSING AND COMMUNICATION FOR SECURE INTERNET OF BODIES (IOB)

Baibhab Chatterjee (9524162) 28 July 2022 (has links)
<p>The last few decades have witnessed unprecedented growth in multiple areas of electronics spanning low-power sensing, intelligent computing and high-speed wireless connectivity. In the foreseeable future, there would be hundreds of billions of computing devices, sensors, things and people, wherein the technology will become intertwined with our lives through continuous interaction and collaboration between humans and machines. Such human-centric ideas give rise to the concept of internet of bodies (IoB), which calls for novel and energy-efficient techniques for sensing, processing and secure communication for resource-constrained IoB nodes.As we have painfully learnt during the pandemic, point-of-care diagnostics along with continuous sensing and long-term connectivity has become one of the major requirements in the healthcare industry, further emphasizing the need for energy-efficiency and security in the resource-constrained devices around us.</p> <p>  </p> <p>  With this vision in mind, I’ll divide this dissertation into the following chapters. The first part (Chapter 2) will cover time-domain sensing techniques which allow inherent energy-resolution scalability, and will show the fundamental limits of achievable resolution. Implementations will include 1) a radiation sensing system for occupational dosimetry in healthcare and mining applications, which can achieve 12-18 bit resolution with 0.01-1 µJ energy dissipation, and 2) an ADC-less neural signal acquisition system with direct Analog to Time Conversion at 13pJ/Sample. The second part (Chapters 3 and 4) of this dissertation will involve the fundamentals of developing secure energy-efficient electro-quasistatic (EQS) communication techniques for IoB wearables as well as implants, and will demonstrate  2 examples: 1) Adiabatic Switching for breaking the αCV^2f limit of power consumption in capacitive voltage mode human-body communication (HBC), and 2) Bi-Phasic Quasistatic Brain Communication (BP-QBC) for fully wireless data transfer from a sub-6mm^3, 2 µW brain implant. A custom modulation scheme, along with adiabatic communication enables wireline-like energy efficiencies (<5pJ/b) in HBC-based wireless systems, while the BP-QBC node, being fully electrical in nature, demonstrates sub-50pJ/b efficiencies by eliminating DC power consumption, and by avoiding the transduction losses observed in competing technologies, involving optical, ultrasound and magneto-electric modalities. Next in Chapter 5, we will show an implementation of a reconfigurable system that would include 1) a human-body communication transceiver and 2) a traditional wireless (MedRadio) transceiver on the same integrated circuit (IC), and would demonstrate methods to switch between the two modes by detecting the placement of the transmitter and receiver devices (on-body/away from the body). Finally, in Chapter 6, we shall show a technique of augmenting security in resource-constrained devices through authentication using the Analog/RF properties of the transmitter, which are usually discarded as non-idealities in a digital transceiver chain. This method does not require any additional hardware in the transmitter, making it an extremely promising technique to augment security in highly resource-constrained scenarios. Such energy-efficient intelligent sensing and secure communication techniques, when combined with intelligent in-sensor-analytics at the resource-constrained nodes, can potentially pave the way for perpetual, and even batteryless systems for next-generation IoT, IoB and healthcare applications.</p>
10

<b>Digital Health And Improvement Of Healthcare Access</b>

Mateus Schmitt (18445557) 26 April 2024 (has links)
<p dir="ltr">Digital Health technologies have revolutionized healthcare delivery, offering innovative solutions that enhance access, improve patient outcomes, and optimize the use of resources. Despite this advancement, health outcomes remain disparate across different social groups, with underprivileged populations at an increased risk of poor health outcomes due to inadequate access to care. Digital Health technologies serve as a critical intervention in mitigating these disparities, particularly for groups affected by geographical, economic, and infrastructural barriers.<br><br>The purpose of this study was to conduct a review of the current state of Digital Health technologies, including Software as a Medical Device (SaMD), Wearable Health, Portable Diagnostic Devices, and remote care platforms, and their impact on healthcare accessibility. Employing qualitative methodology, this metasynthesis emphasized an important discovery: the need for a paradigm shift among stakeholders in healthcare towards integrated and digitally-driven patient care. This shift requires more than just an understanding of new technologies. It demands a fundamental re-evaluation of patient care methods and the orchestration of the entire healthcare system towards integrated digital practices. Importantly, this study found that the pace of digitalization must be carefully managed and cultural factors must be considered and signals the urgency for a balanced approach to digital integration in healthcare.</p>

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