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1
Acampora, Alessandro. "Nonlinear simulation and design of microwave, multi-device distributed autonomous circuits." Doctoral thesis, Universitat Politècnica de Catalunya, 2013. http://hdl.handle.net/10803/128791.
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It is widely believed that many drawbacks in today's wireless communication paradigm might be relieved by enabling high carrier frequency transmission, and endowing both the network and the user equipment with some degree of reconfigurability. The urgency of a new
framework in wireless digital transmission which should allow for higher bit rate, lower latency and tighter delay constraints, led us to investigate the fundamental building blocks which, at the circuital/device level, will foster a change towards more efficient communication schemes, delivering a more satisfactory end user experience.
Specifically, this work deals with the inherently analog devices, found at the core of each transceiver module and capable of providing the carrier signal; these are the oscillators. In particular, two distinct classes of oscillators are regarded central to our contribution. One class is
constituted by N-push oscillators, which thanks to coupling effect of N identical core oscillators allow N-fold harmonic generation (and thus high frequency transmission). The second class is constituted by wideband tunable oscillators, whose topology derives from a feedback distributed amplifier and therefore called distributed oscillators; by adequately altering the bias level at each section Distributed Voltage Controlled Oscillators can be implemented (which can scan a wide frequency range). The introductory part of this work, deals with their operation principles in great detail.
As microwave oscillators are nonlinear devices, a full nonlinear analysis, synthesis, and optimization is considered for their implementation. Consequently, nonlinear numerical techniques have been reviewed in the second part of the thesis. Particularly, the role of Harmonic
Balance simulations and the auxiliary generator/probe method for obtaining the oscillator solutions has been emphasized; the overall research goal of this dissertation is to show that the former techniques are very effective in obtaining detailed information about the periodic steady state behavior for the two class of circuits being investigated.
A triple-push oscillator topology has been initially considered. Provided a certain phase distribution is maintained among the oscillating elements, the output power of the third harmonic increases while the lower order harmonics cancel out, which represents the default operating mode. Due to circuit symmetry, to the presence of delay in the coupling network and to unavoidable mismatches, unwanted oscillating modes might coexist with the intended one. A design strategy relying on the Harmonic Balance parametric analysis of the oscillating voltage at a selected node in the coupling network with respect to coupling phase and coupling strength is presented, to the aim of quenching undesired oscillation modes. Moreover the design of a four stage reverse mode distributed voltage controlled oscillator
(DVCO) has been described. All the design steps have been reported, from a very idealized, purely behavioral design to a very concrete one, involving details derived from electromagnetic simulations. Harmonic Balance techniques were used to evaluate its tuning function, output power and DC current consumption, which have been completely characterized across the tuning bandwidth. Finally, a method for an optimized design with reduced variations in the output power has been presented. An alternative implementation, targeting wider tuning ranges/ higher oscillation frequencies was introduced. The measurements performed on the fabricated prototypes revealed good agreement with the simulation results, confirming the validity of the approach.
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Miller, Benjamin D. "Improvised explosive device placement detection from a semi-autonomous ground vehicle." Thesis, Monterey, Calif. : Naval Postgraduate School, 2006. http://bosun.nps.edu/uhtbin/hyperion.exe/06Dec%5FMiller%5FBenjamin.pdf.
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Thesis (M.S. in Applied Physics)--Naval Postgraduate School, December 2006.Thesis Advisor(s): Richard Harkins, Nancy Haegel. "December 2006." Includes bibliographical references (p. 91-92). Also available in print.
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Liu, Qinyuan (Qingyuan Chen), and Albert Hernández. "Design of autonomous robot device for accurate pacing of track athletes." Thesis, Massachusetts Institute of Technology, 2008. http://hdl.handle.net/1721.1/45329.
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Thesis (S.B.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering, 2008.Includes bibliographical references (leaf 42).
Given the health and weight gain concerns plaguing the country, there is currently a great need for products that encourage athletic activity. A robotic pacing device that facilitates running along a track was developed to help fulfill this requirement. The need for this device, determined from interviews and a survey of experienced running athletes and coaches, was found to be substantial for a number of age groups and experience levels of runners. An experimental robot prototype was designed and manufactured to aid in pacing runners around a track. The robot was designed to accurately follow the lines of the track using IR sensors that detect reflectivity of the track's surface. The prototype was tested and optimized to determine a successful control logic that reduced error and the amount of overshoot the robot experiences as it adjusts to follow the lines at high speeds. Large overshoots lead to robot malfunction and breakdown in the logic as the robot reaches curves in the track. The optimized prototype currently has the capability of running full lengths around various shaped tracks that incorporate white lines dividing dark colored lanes at speeds of up to eight miles per hour. In this form, the robot might be useful for beginner runners, runners that are doing distance training, and physical education classes that have access to running tracks. Future versions of the robot pacing device will need to incorporate additional features in order to be useful for the full range of people that want to use this product, including a flexible user interface that allows users to program the robot to their needs, a more sophisticated robot control system that allows for accurate control based on the dynamics of the robot, and a more durable cover that is easily spotted by runners looking straight ahead.
by Qinyuan (Chen) Liu and Albert Hernandez.
S.B.
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Anandani, Vijay. "Autonomous vehicle control using electroencephalography signals extracted from NeuroSky MindWave device." Thesis, California State University, Long Beach, 2016. http://pqdtopen.proquest.com/#viewpdf?dispub=10182137.
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The current project presents the hardware implementation and experimental testing of a system that uses electroencephalography (EEG) signals to control the motions of a vehicle through a brain-computer interface device. The user's brain activity is monitored continuously by the NeuroSky MindWave headset, and the EEG signals are processed and provided as inputs to the vehicle control system. The brain functions of interest are the user's attention level, meditation level and ocular blink rate. The values of these signals are transmitted to a microcontroller, which will command the vehicle's motor to initiate motion, stop, or change direction based on the user's brain activity. The current project can find a significant number of applications, since about 17% of the population have disabilities and one million people use wheelchairs, including manually and electrically powered chairs.
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Wendell, Dawn M. (Dawn Marie) 1983. "Conditioning planaria : device design based on an autonomous, large-scale parallel approach." Thesis, Massachusetts Institute of Technology, 2004. http://hdl.handle.net/1721.1/32795.
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Thesis (S.B.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering, 2004.Includes bibliographical references (leaves 27-29).
Current behavioral research is conducted on planaria that have been conditioned manually, one at a time by a person. In an attempt to instrument at an organism level, a design for an environment that automatically conditions multiple planaria in parallel was produced. This design consisted of a testing chamber that could stimulate the planaria using electrical shock and light. A computer program was also written to automatically record the results of the experiments for later analysis by researchers. This design was tested and the results were inconclusive based on technical issues with the experimental procedure. Further research is necessary to determine the validity of this device's ability to condition planaria.
by Dawn M. Wendell.
S.B.
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Bleakley, Steven Shea, and steven bleakley@qr com au. "Time Frequency Analysis of Railway Wagon Body Accelerations for a Low-Power Autonomous Device." Central Queensland University, 2006. http://library-resources.cqu.edu.au./thesis/adt-QCQU/public/adt-QCQU20070622.121515.
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This thesis examines the application of the techniques of Fourier spectrogram and wavelet analysis to a low power embedded microprocessor application in a novel railway and rollingstock monitoring system.
The safe and cost effective operation of freight railways is limited by the dynamic performance of wagons running on track. A monitoring system has been proposed comprising of low cost wireless sensing devices, dubbed Health Cards, to be installed on every wagon in the fleet. When marshalled into a train, the devices would sense accelerations and communicate via radio network to a master system in the locomotive. The integrated system would provide online information for decision support systems.
Data throughput was heavily restricted by the network architecture, so significant signal analysis was required at the device level. An electronics engineering team at Central Queensland University developed a prototype Health Card, incorporating a 27MHz microcontroller and four dual axis accelerometers. A sensing arrangement and online analysis algorithms were required to detect and categorise dynamic events while operating within the constraints of the system.
Time-frequency analysis reveals the time varying frequency content of signals, making it suitable to detect and characterise transient events. With efficient algorithms such as the Fast Fourier Transform, and Fast Wavelet Transform, time-frequency analysis methods can be implemented on a low power, embedded microcontroller.
This thesis examines the application of time-frequency analysis techniques to wagon body acceleration signals, for the purpose of detecting poor dynamic performance of the wagon-track system. The Fourier spectrogram is implemented on the Health Card prototype and demonstrated in the laboratory. The research and algorithms provide a foundation for ongoing development as resources become available for system testing and validation.
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Mokhtar, Maizura. "Bio-Inspired Autonomous Hardware Neuro-controller Device on an FPGA Inspired by the Hippocampus." Thesis, University of York, 2008. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.490697.
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One method in achieving artificial intelligence is by emulating biological concepts onto an electronic device, specifically how a biological organism governs its behaviour. This research project investigates how the hippocampus works; and attempts to model this region of the brain onto an electronic device. The hippocampus is chosen because this is one of the regions in the brain responsible for learning and memory. This study uses models of the pyramidal neurons in the hippocampus as well as its spatial representation as the design components for a hardware neuro-controller module. The method chosen to model the individual neurons is the two-dimensional bio-inspired Izhikevich algorithm that has the ability to describe a variety of neuron dynamic behaviours observed in the brain. The hippocampus-inspired spiking neural network architecture also includes place cells/place field representation, a rate-based representation that provides spatial representation of the environment to the hippocampus. A biological nervous system is a dynamical system; it is governed by the learning rules that adjust the strength of connectivity between the neurons in the neural network. These learning rules are implemented to the hippocampus-inspired spiking neural network to allow the neural network to perform its task of path navigation. Following successful simulations of the software prototype of the neural network architecture in performing its desired task, this architecture is then synthesized onto a Field Programmable Gate Array (FPGA) device. This is to allow the neural network architecture to be utilized as a neuro-controller device for the purpose of path navigation, creates memories, and thus achieving autonomy.
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Ringaby, Erik. "Optical Flow Computation on Compute Unified Device Architecture." Thesis, Linköping University, Department of Electrical Engineering, 2008. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-15426.
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There has been a rapid progress of the graphics processor the last years, much because of the demands from computer games on speed and image quality. Because of the graphics processor’s special architecture it is much faster at solving parallel problems than the normal processor. Due to its increasing programmability it is possible to use it for other tasks than it was originally designed for.
Even though graphics processors have been programmable for some time, it has been quite difficult to learn how to use them. CUDA enables the programmer to use C-code, with a few extensions, to program NVIDIA’s graphics processor and completely skip the traditional programming models. This thesis investigates if the graphics processor can be used for calculations without knowledge of how the hardware mechanisms work. An image processing algorithm calculating the optical flow has been implemented. The result shows that it is rather easy to implement programs using CUDA, but some knowledge of how the graphics processor works is required to achieve high performance.
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Genot, Anthony. "DNA autonomous devices." Thesis, University of Oxford, 2011. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.543551.
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Cervia, Giulia. "Coordination d’appareils autonomes sur canaux bruités : régions de capacité et algorithmes de codage." Thesis, Cergy-Pontoise, 2018. http://www.theses.fr/2018CERG0960/document.
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Les réseaux de 5ème génération se caractérisent par la communication directe entre machines (M2M) et l’Internet des Objets, un réseau unifié d’objets connectés. Dans ce contexte, les appareils communicants sont des décideurs autonomes qui coopérent, coordonnent leurs actions et se reconfigurent de manière dynamique enfonction de leur environnement. L’enjeu est de développer des algorithmes efficaces pour coordonner les actions des appareils autonomes constituant le réseau.La théorie de l’information nous permet d’étudier le comportement de long-terme des appareils grâce aux distributions de probabilité conjointes. En particulier, nous sommes intéressés par la coordination forte, qui exige que la distribution induite sur les suites d’actions converge en distance L^1 vers une distribution i.i.d. cible.Nous considérons un model point-à-point composé d’une source d’information, d’un encodeur, d’un canal bruité, d’un décodeur, d’une information commune et nous cherchons à coordonner les signaux en entrée et en sortie du canal avec la source et sa reconstruction.Nos premiers résultats sont des bornes intérieures et extérieure pour la région de coordination forte, c’est-à-dire l’ensemble des distributions de probabilité conjointes réalisables et la quantité d’information commune requise.Ensuite, nous caractérisons cette région de coordination forte dans trois cas particuliers: lorsque le canal est parfait, lorsque le décodeur est sans perte et lorsque les variables aléatoires du canal sont indépendantes des variables aléatoires de la source. L’étude de ce dernier cas nous permet de remettre en cause le principe de séparation source-canal pour la coordination forte. Nous démontrons également que la coordination forte offre “gratuitement” des garanties de sécurité au niveau de la couche physique.Par ailleurs, nous étudions la coordination sous l’angle du codage polaire afin de développer des algorithmes de codage implémentables. Nous appliquons la polarisation de la source de manière à créer un schéma de codage explicite qui offre une alternative constructive aux preuves de codage aléatoires5G networks will be characterized by machine to machine communication and the Internet of Things, a unified network of connected objects. In this context, communicating devices are autonomous decision-makers that cooperate, coordinate their actions, and reconfigure dynamically according to changes in the environment.To do this, it is essential to develop effective techniques for coordinating the actions of the nodes in the network.Information theory allows us to study the long-term behavior of the devices through the analysis of the joint probability distribution of their actions. In particular, we are interested in strong coordination, which requires the joint distribution of sequences of actions to converge to an i.i.d. target distribution in L^1 distance.We consider a two-node network comprised of an information source and a noisy channel, and we require the coordination of the signals at the input and at the output of the channel with the source and the reconstruction. We assume that the encoder and decoder share a common source of randomness and we introduce a state capturing theeffect of the environment.The first objective of this work is to characterize the strong coordination region, i.e. the set of achievable joint behaviors and the required minimal rates of common randomness. We prove inner and outer bounds for this region. Then, we characterize the exact coordination region in three particular cases: when the channel is perfect, when the decoder is lossless and when the random variables of the channel are separated from the random variables of the source.The study of the latter case allows us to show that the joint source-channel separation principle does not hold for strong coordination. Moreover, we prove that strong coordination offers “free” security guarantees at the physical layer.The second objective of this work is to develop practical codes for coordination: by exploiting the technique of source polarization, we design an explicit coding scheme for coordination, providing a constructive alternative to random coding proofs
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Nyström, Daniel. "Colorimetric and Multispectral Image Acquisition." Licentiate thesis, Linköping University, Linköping University, Department of Science and Technology, 2006. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-8866.
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The trichromatic principle of representing color has for a long time been dominating in color imaging. The reason is the trichromatic nature of human color vision, but as the characteristics of typical color imaging devices are different from those of human eyes, there is a need to go beyond the trichromatic approach. The interest for multi-channel imaging, i.e. increasing the number of color channels, has made it an active research topic with a substantial potential of application.
To achieve consistent color imaging, one needs to map the imaging-device data to the device-independent colorimetric representations CIEXYZ or CIELAB, the key concept of color management. As the color coordinates depend not only on the reflective spectrum of the object but also on the spectral properties of the illuminant, the colorimetric representation suffers from metamerism, i.e. objects of the same color under a specific illumination may appear different when they are illuminated by other light sources. Furthermore, when the sensitivities of the imaging device differ from the CIE color matching functions, two spectra that appear different for human observers may result in identical device response. On contrary, in multispectral imaging, color is represented by the object’s physical characteristics namely the spectrum which is illuminant independent. With multispectral imaging, different spectra are readily distinguishable, no matter they are metameric or not. The spectrum can then be transformed to any color space and be rendered under any illumination.
The focus of the thesis is high quality image-acquisition in colorimetric and multispectral formats. The image acquisition system used is an experimental system with great flexibility in illumination and image acquisition setup. Besides the conventional trichromatic RGB filters, the system also provides the possibility of acquiring multi-channel images, using 7 narrowband filters. A thorough calibration and characterization of all the components involved in the image acquisition system is carried out. The spectral sensitivity of the CCD camera, which can not be derived by direct measurements, is estimated using least squares regression, optimizing the camera response to measured spectral reflectance of carefully selected color samples.
To derive mappings to colorimetric and multispectral representations, two conceptually different approaches are used. In the model-based approach, the physical model describing the image acquisition process is inverted, to reconstruct spectral reflectance from the recorded device response. In the empirical approach, the characteristics of the individual components are ignored, and the functions are derived by relating the device response for a set of test colors to the corresponding colorimetric and spectral measurements, using linear and polynomial least squares regression.
The results indicate that for trichromatic imaging, accurate colorimetric mappings can be derived by the empirical approach, using polynomial regression to CIEXYZ and CIELAB. Because of the media-dependency, the characterization functions should be derived for each combination of media and colorants. However, accurate spectral data reconstruction requires for multi-channel imaging, using the model-based approach. Moreover, the model-based approach is general, since it is based on the spectral characteristics of the image acquisition system, rather than the characteristics of a set of color samples.
Report code: LiU-TEK-LIC- 2006:70
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Celý, Martin. "Zvýšení účinnosti spalovacího motoru pro malé autonomní prostředky." Master's thesis, Vysoké učení technické v Brně. Fakulta strojního inženýrství, 2021. http://www.nusl.cz/ntk/nusl-444982.
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The work deals with the analysis of various possibilities of increasing the efficiency of a small internal combustion engine potentially usable for use in the field of autonomous devices of smaller dimensions. It contains an outline of the problems of modern smaller autonomous means and an analysis of available drives designed for them, especially an analysis of propulsion by internal combustion engines. In his next part of the work he provides information about the created mathematical model of the demonstration internal combustion engine in the GT-Power program and an analysis of places where and in what ways its efficiency can be increased. The design of two such components together with the evaluation of the achieved results offers the conclusion of this work.
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Pettersson, Tobias. "Synchronization of flywheel position between autonomous devices." Thesis, Linköpings universitet, Datorteknik, 2012. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-78546.
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More computing power will be required in Scania’s future engine control units. Calculations is therefore needed to be performed on new hardware such as an FPGA. One problem that arises is synchronization of flywheelposition. This master thesis examines the opportunities existing Scania hardware has to perform synchronization of flywheel position. Different concepts for synchronization have been developed and compared with each other. One of the concepts have been implemented and made possible witha PCB-adapter. The results show that synchronization is possible within given real-time requirements. Finally, an analysis to series production has been made. It show the challenges that an FPGA will face when integrated into a future engine control unit.
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Zhou, Wei. "Autonomous smart antenna systems for future mobile devices." Thesis, University of Edinburgh, 2015. http://hdl.handle.net/1842/9959.
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Along with the current trend of wireless technology innovation, wideband, compact size, low-profile, lightweight and multiple functional antenna and array designs are becoming more attractive in many applications. Conventional wireless systems utilise omni-directional or sectored antenna systems. The disadvantage of such antenna systems is that the electromagnetic energy, required by a particular user located in a certain direction, is radiated unnecessarily in every direction within the entire cell, hence causing interference to other users in the system. In order to limit this source of interference and direct the energy to the desired user, smart antenna systems have been investigated and developed. This thesis presents the design, simulation, fabrication and full implementation of a novel smart antenna system for future mobile applications. The design and characterisation of a novel antenna structure and four-element liner array geometry for smart antenna systems are proposed in the first stage of this study. Firstly, a miniaturised microstrip-fed planar monopole antenna with Archimedean spiral slots to cover WiFi/Bluetooth and LTE mobile applications has been demonstrated. The fundamental structure of the proposed antenna element is a circular patch, which operates in high frequency range, for the purpose of miniaturising the circuit dimension. In order to achieve a multi-band performance, Archimedean spiral slots, acting as resonance paths, have been etched on the circular patch antenna. Different shapes of Archimedean spiral slots have been investigated and compared. The miniaturised and optimised antenna achieves a bandwidth of 2.2GHz to 2.9GHz covering WiFi/Bluetooth (2.45GHz) and LTE (2.6GHz) mobile standards. Then a four-element linear antenna array geometry utilising the planar monopole elements with Archimedean spiral slots has been described. All the relevant parameters have been studied and evaluated. Different phase shifts are excited for the array elements, and the main beam scanning range has been simulated and analysed. The second stage of the study presents several feeding network structures, which control the amplitude and phase excitations of the smart antenna elements. Research begins with the basic Wilkinson power divider configuration. Then this thesis presents a compact feeding network for circular antenna array, reconfigurable feeding networks for tuning the operating frequency and polarisations, a feeding network on high resistivity silicon (HRS), and an ultrawide-band (UWB) feeding network covering from 0.5GHz to 10GHz. The UWB feeding network is used to establish the smart antenna array system. Different topologies of phase shifters are discussed in the third stage, including ferrite phase shifters and planar phase shifters using switched delay line and loaded transmission line technologies. Diodes, FETs, MMIC and MEMS are integrated into different configurations. Based on the comparison, a low loss and high accurate Hittite MMIC analogue phase shifter has been selected and fully evaluated for this implementation. For the purpose of impedance matching and field matching, compact and ultra wideband CPW-to-Microstrip transitions are utilised between the phase shifters, feeding network and antenna elements. Finally, the fully integrated smart antenna array achieves a 10dB reflection coefficient from 2.25GHz to 2.8GHz, which covers WiFi/Bluetooth (2.45GHz) and LTE (2.6GHz) mobile applications. By appropriately controlling the voltage on the phase shifters, the main beam of the antenna array is steered ±50° and ±52°, for 2.45GHz and 2.6GHz, respectively. Furthermore, the smart antenna array demonstrates a gain of 8.5dBi with 40° 3dB bandwidth in broadside direction, and has more than 10dB side lobe level suppression across the scan. The final stage of the study investigates hardware and software automatic control systems for the smart antenna array. Two microcontrollers PIC18F4550 and LPC1768 are utilised to build the control PCBs. Using the graphical user interfaces provided in this thesis, it is able to configure the beam steering of the smart antenna array, which allows the user to analyse and optimise the signal strength of the received WiFi signals around the mobile device. The design strategies proposed in this thesis contribute to the realisation of adaptable and autonomous smart phone systems.
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Eltaher, Eltazy Mohammed Khalid. "Modelling and applications of autonomous flow control devices." Thesis, Heriot-Watt University, 2017. http://hdl.handle.net/10399/3321.
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Inflow Control technology has been employed in long, horizontal wells completions since the early 1990s. Their introduction prompted the extension of reservoir and well simulators to support their modelling and optimisation. More recently, Autonomous Flow Control Devices (AFCDs) have further improved well performance. However, the impact of AFCDs on reservoir management cannot yet be confidently predicted since their (autonomous) discrimination and control of the different fluid phases presents new modelling challenges that require extension of today’s wellbore/reservoir models and workflows. Novel methods to visualise and optimise AFCD completions are also required. This thesis shows how to use widely available, commercial codes to reliably simulate wells completed with AFCDs. Workflows for the optimal design and quantification of the economic value of such completions have been developed. The resulting predictions are compared with published data (AFCD calibration curves). They are used to evaluate the AFCD-completions “added-value” for a range of reservoir types, device specifications and fluids. This work particularly addresses: i. Performance of the device - little published data on AFCD multi-phase flow performance is available. Also, commercial reservoir simulators provide just one equation to capture the underlying physics of all AFCD types. ii. Wellbore model - a representative reservoir/wellbore model and the previously ignored physics (stratified flow in the annulus and well trajectory alteration) are now essential since an AFCD’s performance is strongly fluid-sensitive. The above AFCD modelling and optimisation challenges are addressed by: 1) Developing an AFCD performance model that honours published data. Equations and modelling recommendations for several commercial AFCDs along with a range of modelling options, some novel and bespoke, are presented. The impact of uncertain multiphase flow performance on the AFCD well’s “Added-Value” is quantified. 2) Increasing the accuracy of commercial well/reservoir simulators when modelling AFCD completions by recommending how to model the well trajectory, the reservoir/well segmentation and the multiphase flow performance. 3) Comparing the performance of optimised AFCD- and ICD-completions in multiple reservoir models to illustrate how various reservoir management challenges can be met.
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Koo, Bon Ho Brandon. "Autonomous active ankle exo-skeleton devices provide metabolic cost reduction." Thesis, Massachusetts Institute of Technology, 2019. https://hdl.handle.net/1721.1/123284.
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Thesis: S.B., Massachusetts Institute of Technology, Department of Mechanical Engineering, 2019Cataloged from PDF version of thesis.
Includes bibliographical references (pages 35-36).
In this thesis, I designed and conducted an experiment that looks to confirm the metabolic cost decrease associated with the usage of an autonomous active ankle exoskeleton. The primary method to identify the associated metabolic costs was through the comparison of cardiovascular and respiratory activity during gait with and without the use of the exoskeleton. Rates of oxygen consumption, carbon dioxide production, and pulse were recorded for both control and experimental trials. Using these physiological responses, associated energy expenditure rates were calculated. The results of these trials suggest the presence of a quantifiable reduction in energy expenditure rate seen by the implementation of an autonomous active ankle exoskeleton in flat-terrain walking protocols. Additionally, the time to convergence, defined as the time a particular data-set takes to reach steady-state, was calculated using the same physiological responses. The results of this observation suggest that the time to convergence of metabolic indicators is much shorter than previously assumed. Finally, the potential benefits of utilizing a custom exoskeleton interface are quantified and elaborated.
by Bon Ho Brandon Koo.
S.B.
S.B. Massachusetts Institute of Technology, Department of Mechanical Engineering
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Duan, Quiyi. "Autonomous and Intelligent Radio Switching." BYU ScholarsArchive, 2008. https://scholarsarchive.byu.edu/etd/1835.
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With the proliferation of mobile applications and the abundance of wireless devices, it is increasingly common for devices to support multiple radios. When two devices are communicating they should choose the best available radio based on user preference and application requirements. This type of “radio switching” should happen automatically, so that the system optimizes performance dynamically. To achieve this objective, we design an Autonomous and Intelligent Radio Switching (AIRS) system to leverage the radio heterogeneity common in today's wireless devices. The AIRS system consists of three key components. First, we design a radio preference evaluation module to dynamically select the best radio according to users' preference, application's QoS requirements, and the device battery usage. Second, we propose a link quality measurement and prediction module to predict the radio quality under a variety of mobility and interference conditions. Third, we present a radio switching decision making module to switch to the preferred available radio intelligently, based on the preference and link quality evaluations. The AIRS system maintains connectivity, as well as improves link quality, via dynamic and intelligent radio switching, regardless of interference or collisions from the interfaces of other devices. The radio preference evaluation module is able to generate and adjust a preference list dynamically. Multiple users' requirements are satisfied in a mutually beneficial manner and the selected radio is Pareto optimal. The link prediction module is able to achieve an accuracy above 90% under a variety of mobility and interference conditions. The module can dynamically increase the link measurement interval and significantly reduce its power consumption, without sacrificing accuracy. The decision algorithm uses several parameters to avoid switching radios too frequently, and is able to provide dynamic, but stable radio switching, while balancing the competing objectives of high throughput and low power consumption. Overall, the AIRS system is able to achieve high goodput (application level throughput) and long battery life as applied to handoff management in a frequently changing mobile environment.
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Imran, Naveed. "Autonomous Recovery of Reconfigurable Logic Devices using Priority Escalation of Slack." Doctoral diss., University of Central Florida, 2013. http://digital.library.ucf.edu/cdm/ref/collection/ETD/id/5949.
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Field Programmable Gate Array (FPGA) devices offer a suitable platform for survivable hardware architectures in mission-critical systems. In this dissertation, active dynamic redundancy-based fault-handling techniques are proposed which exploit the dynamic partial reconfiguration capability of SRAM-based FPGAs. Self-adaptation is realized by employing reconfiguration in detection, diagnosis, and recovery phases.
To extend these concepts to semiconductor aging and process variation in the deep submicron era, resilient adaptable processing systems are sought to maintain quality and throughput requirements despite the vulnerabilities of the underlying computational devices. A new approach to autonomous fault-handling which addresses these goals is developed using only a uniplex hardware arrangement. It operates by observing a health metric to achieve Fault Demotion using Reconfigurable Slack (FaDReS). Here an autonomous fault isolation scheme is employed which neither requires test vectors nor suspends the computational throughput, but instead observes the value of a health metric based on runtime input. The deterministic flow of the fault isolation scheme guarantees success in a bounded number of reconfigurations of the FPGA fabric.
FaDReS is then extended to the Priority Using Resource Escalation (PURE) online redundancy scheme which considers fault-isolation latency and throughput trade-offs under a dynamic spare arrangement. While deep-submicron designs introduce new challenges, use of adaptive techniques are seen to provide several promising avenues for improving resilience. The scheme developed is demonstrated by hardware design of various signal processing circuits and their implementation on a Xilinx Virtex-4 FPGA device. These include a Discrete Cosine Transform (DCT) core, Motion Estimation (ME) engine, Finite Impulse Response (FIR) Filter, Support Vector Machine (SVM), and Advanced Encryption Standard (AES) blocks in addition to MCNC benchmark circuits. A significant reduction in power consumption is achieved ranging from 83% for low motion-activity scenes to 12.5% for high motion activity video scenes in a novel ME engine configuration. For a typical benchmark video sequence, PURE is shown to maintain a PSNR baseline near 32dB. The diagnosability, reconfiguration latency, and resource overhead of each approach is analyzed. Compared to previous alternatives, PURE maintains a PSNR within a difference of 4.02dB to 6.67dB from the fault-free baseline by escalating healthy resources to higher-priority signal processing functions. The results indicate the benefits of priority-aware resiliency over conventional redundancy approaches in terms of fault-recovery, power consumption, and resource-area requirements. Together, these provide a broad range of strategies to achieve autonomous recovery of reconfigurable logic devices under a variety of constraints, operating conditions, and optimization criteria.Ph.D.
Doctorate
Electrical Engineering and Computer Science
Engineering and Computer Science
Electrical Engineering
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Hewitt, Daniel. "Detecting freeplay in mechanical systems : for the development of autonomous sensing devices." Thesis, University of Bristol, 2016. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.701380.
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This thesis is a study of freeplay - gaps between notionally connected components in mechanical systems. For some systems any amount of freeplay can complicate closed loop control design and introduce energetic impacts between bearing components. The work was motivated by freeplay present in the control systems-of rotorcraft and explores the viability of developing sensing devices to detect freeplay during operation. In this work a generic freeplay model is introduced from first principles which predicts potential measures of a system that could indicate the level freeplay. To validate these measures a mechanical experiment is constructed which represents a minimum working example of a freeplay system. It is designed to exclude as many sources of variability as possible and offers unparalleled completeness and acuity of generated data. A novel mathematical model is derived (and found to be in good agreement with the gathered experimental data) which validates the theorised damage sensitive features. Freeplay sensitive features are used as detection metrics in two real systems. First, on data gathered from the experiment; A freeplay detection system was created which determined the level of freeplay to a high accuracy using data gathered from a single accelerometer. Second, to strain measurements taken from a rotorcraft in flight; It was found that some metrics derived from earlier work were not good predictors of freeplay on rotorcraft data, but, using a selection of data processing techniques, a bespoke freeplay detection system was successful for many flight conditions. The work in this thesis is a strong indicator that detection of freeplay is possible for certain classes of systems using autonomous devices. Positive identification of freeplay in a simple and a complex freeplay system have been shown and a critical review is offered of the conclusions, limitations and some opportunities for future study.
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Min, Hong-Seok. "The development of microbatteries based on three-dimensional architectures for autonomous micro devices." Diss., Restricted to subscribing institutions, 2007. http://proquest.umi.com/pqdweb?did=1320958771&sid=1&Fmt=2&clientId=1564&RQT=309&VName=PQD.
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Young, Forrest C. "Phoenix autonomous underwater vehicle (AUV) : networked control of multiple analog and digital devices using LonTalk /." Monterey, Calif. : Springfield, Va. : Naval Postgraduate School ; Available from National Technical Information Service, 1997. http://handle.dtic.mil/100.2/ADA342308.
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Thesis (M.S. in Electrical Engineering)) Naval Postgraduate School, December 1997."December 1997." Thesis advisor(s): Xiaoping Yun, Don Brutzman. DTIC Descriptors: Underwater Vehicles, Autonomous Navigation, Digital Communications, Signal Processing, Robotics, Real Time, Robots, Computer Architecture, Theses, Analog to Digital Converters, Digital To Analog Converters. Author(s) subject terms: Autonomous Underwater Vehicle, AUV, Networked Control, Lon Works Technology, LonTalk, LonBuilder. Includes bibliographical references (p. 93-94). Also available online.
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Korkmaz, Ozan. "Modeling And Control Of Autonomous Underwater Vehicle Manipulator Systems." Phd thesis, METU, 2012. http://etd.lib.metu.edu.tr/upload/12615051/index.pdf.
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In this thesis, dynamic modeling and nonlinear control of autonomous underwater vehicle manipulator systems are presented. Mainly, two types of systems consisting of a 6-DOF AUV equipped with a 6-DOF manipulator subsystem (UVMS) and with an 8-DOF redundant manipulator subsystem (UVRMS) are modeled considering hydrostatic forces and hydrodynamic effects such as added mass, lift, drag and side forces. The shadowing effects of the bodies on each other are introduced when computing the hydrodynamic forces. The system equations of motion are derived recursively using Newton&ndashEuler formulation. The inverse dynamics control algorithms are formulated and trajectory tracking control of the systems is achieved by assigning separate tasks for the end effector of the manipulator and for the underwater vehicle. The proposed inverse dynamics controller utilizes the full nonlinear model of the system and consists of a linearizing control law that uses the feedback of positions and velocities of the joints and the underwater vehicle in order to cancel off the nonlinearities of the system. The PD control is applied after this complicated feedback linearization process yielding second order error dynamics. The thruster dynamics is also incorporated into the control system design. The stability analysis is performed in the presence of parametric uncertainty and disturbing ocean current. The effectiveness of the control methods are demonstrated by simulations for typical underwater missions.
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Pashaei, Vida. "Flexible Body-Conformal Ultrasound Systems for Autonomous Image-Guided Neuromodulation." Case Western Reserve University School of Graduate Studies / OhioLINK, 2021. http://rave.ohiolink.edu/etdc/view?acc_num=case1621006180331273.
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La, Barbera Gaspare. "Dimensionamento di un sistema wireless epidermico energeticamente autonomo per il monitoraggio di parametri fisiologici." Master's thesis, Alma Mater Studiorum - Università di Bologna, 2016. http://amslaurea.unibo.it/10211/.
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Il presente lavoro di Tesi è stato incentrato sul dimensionamento di un sistema wireless epidermico abile a monitorare parametri fisiologici. La fase iniziale del lavoro è stata spesa per indagare le varie tipologie di sorgenti utili ad effettuare Energy Harvesting in contesti applicativi biomedicali, ed analizzare lo stato dell’arte in merito ai sistemi miniaturizzati, passivi, interfacciabili alla superficie corporea, configurabili nel settore di ricerca e-skin. Il corpo centrale del lavoro è stato quello di dimensionare un nuovo sistema wireless epidermico, energeticamente autonomo. Tale sistema è stato strutturato in tre catene costitutive. La prima di queste definita di Energy Harvesting e storage, presenta una cella solare, un boost converter –charger per il management della potenza ed una thin film battery come elemento di storage. La seconda catena è configurabile come quella di ricezione, in cui l’elemento cruciale è una Wake-Up Radio (WUR), la cui funzione è quella di abilitare il sistema di misura costituito da Microcontroller e sensore solo quando un Reader comunicherà la corretta sequenza di bit abilitanti alla lettura. La presente scelta ha mostrato vantaggi in termini di ridotti consumi. La terza ed ultima catena del sistema per mezzo di Microcontrollore e Transceiver consentirà di trasmettere via RF il dato letto al Reader. Una interfaccia grafica utente implementata in Matlab è stata ideata per la gestione dei dati. La sezione ultima della Tesi è stata impostata analizzando i possibili sviluppi futuri da seguire, in particolare integrare il sistema completo utilizzando un substrato flessibile così come il Kapton e dotare il sistema di sensoristica per misure biomediche specialistiche per esempio la misura del SpO2.
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Richter, Viktor [Verfasser]. "Addressing in Smart Environments. An Investigation of Human Conversational Behaviours Towards Devices and Autonomous Agents in a Smart Environment / Viktor Richter." Bielefeld : Universitätsbibliothek Bielefeld, 2020. http://d-nb.info/1211474860/34.
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Horák, Vojtěch. "Zážehový spalovací motor pro malé autonomní prostředky." Master's thesis, Vysoké učení technické v Brně. Fakulta strojního inženýrství, 2020. http://www.nusl.cz/ntk/nusl-417761.
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The thesis deals with the design of a small-volume four-stroke internal combustion engine with a maximum displacement of 10 cc and a power of 1 kW for autonomous devices of smaller dimensions. In addition to the analysis of individual propulsions for small aircraft, there is also a chapter with the comparison of an internal combustion engine and an electric motor with similar power. Another part of the work is the creation of a thermodynamic model in the GT Power program and its subsequent optimization to increase the overall efficiency of the engine.
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Khan, Z. (Zaheer). "Coordination and adaptation techniques for efficient resource utilization in cognitive radio networks." Doctoral thesis, Oulun yliopisto, 2011. http://urn.fi/urn:isbn:9789514295980.
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Abstract The aim of this thesis is to devise coordination and adaptation techniques that enable the wireless devices operating in a cognitive network to utilize their available resources efficiently. The first part of this thesis considers the case where multiple autonomous devices sense the frequency channels sequentially in some sensing order for spectrum opportunities. In particular, the first part is interested in the scenario where devices with false alarms autonomously select the sensing orders in which they visit channels, without coordination from a centralized entity. An adaptive persistent sensing order selection strategy that allows autonomous adaptations to collision-free sensing orders is proposed and evaluated. It is shown that the proposed strategy converges and maximizes cognitive network throughput compared to a random selection of sensing orders. The second part of this thesis considers the case where distributed devices interact with one another to cooperate to fulfill tasks or to improve the efficiency of network resource usage. Tools from coalition formation game theory are adopted to devise dynamic cooperative strategies for distributed devices. Dynamic coalition formation methods, are proposed for two different network scenarios: 1) Distributed devices operating in an interference channel; 2) Distributed devices performing spectrum sensing. It is observed that in distributed spectrum sensing if the devices pursue their goals selfishly then coalition formation may lead to a suboptimal equilibrium where devices, through their interactions, reach an undesirable coalition structure from a network point of view. The proposed selfish model of dynamic coalition formation is then extended to determine whether and how the coalitional behavior of devices will change if coalition formation is ''not entirely selfish''. It is observed that for the problem of distributed spectrum sensing, average throughput per device is increased when devices cooperate to maximize the overall gains of the group as compared to when they cooperate to increase their individual gains. Finally, in the last part of the thesis, to reduce spectrum sensing overhead and total energy consumption of a cognitive radio network, the problem of sensor selection is considered. Different techniques for selecting devices with the best detection performance are proposed, and it is shown that the proposed device selection methods are able to offer significant gains in terms of system performance as compared to a random selection of devicesTiivistelmä Tämän työn tavoitteena oli kehittää koordinointi- ja adaptointimenetelmiä, jotka mahdollistavat langattomien laitteiden toiminnan kognitiivisessa verkossa ja tarjolla olevien resurssien tehokkaan käytön. Työn ensimmäisessä osassa käsitellään tapausta, jossa useat itsenäiset laitteet havainnoivat taajuuskanavien spektriominaisuuksia sekventiaalisesti jossakin järjestyksessä. Ensimmäisessä osassa ollaan erityisesti kiinnostuneita skenaariosta, jossa virheellisen hälytyksen antava laite automaattisesti valitsee kanavien havainnointijärjestyksen, joka tapahtuu ilman keskusyksikön koordinointia. Tässä työssä ehdotetaan ja evaluoidaan adaptiivinen jatkuva havainnointijärjestyksen valintastrategia, joka sallii itsenäisen sopeutumisen törmäysvapaaseen havainnointijärjestykseen. Osoitetaan, että ehdotettu strategia suppenee ja maksimoi kognitiivisen verkon kapasiteetin verrattuna satunnaiseen havainnointijärjestysten valintaan. Työn toisessa osassa pohditaan tilannetta, jossa hajautetut laitteet vuorovaikuttavat keskenään yhteistyössä suorittaakseen tehtäviään tai parantaakseen verkon resurssien käytön tehokkuutta. Peliteoreettisia työkaluja koalitioiden muodostamiseen mukautetaan dynaamisten yhteistoiminnallisten strategioiden laatimiseen hajautetuille laitteille. Dynaamisia koalitioiden muodostamismenetelmiä ehdotetaan kahteen erilaiseen verkkoskenaarioon: 1) hajautetut laitteet toimivat häiriöllisessä kanavassa, 2) hajautetut laitteet suorittavat spektrin havainnointia. Havaitaan, että jos hajautetussa spektrin havainnoinnissa laitteet tavoittelevat päämääriään itsekkäästi, niin koalitioiden muodostaminen voi johtaa alioptimaaliseen tasapainotilaan, jossa laitteet keskinäisen vaikutuksensa kautta saavuttavat verkon näkökulmasta epätoivotun koalitiorakenteen. Ehdotettua itsekästä mallia dynaamiseen koalitioiden muodostamiseen laajennetaan ottamaan selville, miten laitteiden koalitiokäyttäytyminen muuttuu, jos koalitioiden muodostaminen ei ole täydellisen itsekästä. Havaitaan, että hajautetun spektrin havainnoinnin probleemassa, keskimääräinen laitekohtainen kapasiteetti kasvaa kun laitteet tekevät yhteistyötä maksimoidakseen ryhmän kokonaishyödyn verrattuna siihen, jos ne tekevät yhteistyötä lisätäkseen yksittäisiä etujaan. Työn viimeisessä osassa pohditaan sensorien valintaongelmaa. Siinä ehdotetaan erilaisia menetelmiä, jotka valitsevat parhaan suorituskyvyn omaavat laitteet ja näytetään, että ehdotetut laitteiden valintamenetelmät pystyvät tarjoamaan merkittäviä suorituskykyetuja verrattuna satunnaiseen laitteiden valintaan
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Sampson, Nicholas. "Teaching materials and the autonomous language teacher a study of tertiary English teachers in Hong Kong /." Thesis, Click to view the E-thesis via HKUTO, 2009. http://sunzi.lib.hku.hk/hkuto/record/B43085477.
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Leiding, Benjamin [Verfasser], Dieter [Akademischer Betreuer] Hogrefe, Dieter [Gutachter] Hogrefe, Clemens [Gutachter] Cap, and Volker [Gutachter] Skwarek. "The M2X Economy – Concepts for Business Interactions, Transactions and Collaborations Among Autonomous Smart Devices / Benjamin Leiding ; Gutachter: Dieter Hogrefe, Clemens Cap, Volker Skwarek ; Betreuer: Dieter Hogrefe." Göttingen : Niedersächsische Staats- und Universitätsbibliothek Göttingen, 2020. http://d-nb.info/1202604986/34.
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Malleron, Kevin. "Modélisation multiphysique, caractérisation et conception de transducteurs magnétoélectriques pour l'alimentation de capteurs biomédicaux autonomes." Thesis, Sorbonne université, 2018. http://www.theses.fr/2018SORUS203.
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Afin d'éviter une opération de remplacement de la batterie d'un dispositif biomédical, nous proposons d'utiliser une technique innovante de rechargement sans fils utilisant des matériaux magnétoélectriques. L'effet magnétoélectrique extrinsèque est principalement issu de la combinaison de deux phénomènes : piézoélectricité et magnétostriction. L'idée est de réaliser une transmission d'énergie sans fils basée sur les techniques d'induction en champ proche : on applique un champ magnétique, le récepteur qui servira de transducteur d'énergie sera composé d'un matériau magnétostrictif, qui, sous l'effet du champ magnétique va se déformer, les contraintes mécaniques sont transmises au matériau piézoélectrique qui se polarise. On mesure alors une tension électrique aux bornes du piézoélectrique qui peut ensuite servir à alimenter ou recharger un dispositif électronique. Cette thèse contribue au développement de cette technique en proposant des pistes d'améliorations de la puissance transmissible afin de pouvoir alimenter des capteurs avec un transducteur le plus petit possible. Pour ce faire, une modélisation par éléments finis 2D est présentée ainsi que des mesures de puissance et le développement du banc de caractérisation associéIn order to avoid surgery for battery replacement or recharge, we propose to use an innovative technique to wirelessly recharge the battery using magnetoelectric materials. The magnetoelectric effect is issued of two combined phenomena: piezoelectricity and magnetostriction. The idea is to achieve a wireless power transmission based on the near magnetic field techniques: the source energy is emitted via a magnetic field and the receptor which will transduce the energy is a magnetoelectric material. The magnetostrictive part of the magnetoelectric transducer is subjected to a stress due to the magnetic field. The stress is transmitted to the piezoelectric part which will produce an electric field. The electric voltage collected from the electrodes of the piezoelectric material will be used to power or recharge electronic devices. This thesis contributes to the development of this technique by proposing improving ways for energy transmission to powering sensors with the smallest transducer possible. An 2D finite element model his presented with power measurements and the characterizing bench associated
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Erlandsson, Niklas. "Utilizing machine learning in wildlife camera traps for automatic classification of animal species : An application of machine learning on edge devices." Thesis, Linnéuniversitetet, Institutionen för datavetenskap och medieteknik (DM), 2021. http://urn.kb.se/resolve?urn=urn:nbn:se:lnu:diva-104952.
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A rapid global decline in biodiversity has been observed in the past few decades, especially in large vertebrates and the habitats supporting these animal populations. This widely accepted fact has made it very important to understand how animals respond to modern ecological threats and to understand the ecosystems functions. The motion activated camera (also known as a camera trap) is a common tool for research in this field, being well-suited for non-invasive observation of wildlife. The images captured by camera traps in biological studies need to be classified to extract information, a traditionally manual process that is time intensive. Recent studies have shown that the use of machine learning (ML) can automate this process while maintaining high accuracy. Until recently the use of machine learning has required significant computing power, relying on data being processed after collection or transmitted to the cloud. This need for connectivity introduces potentially unsustainable overheads that can be addressed by placing computational resources on the camera trap and processing data locally, known as edge computing. Including more computational power in edge and IoT devices makes it possible to keep the computation and data storage on the edge, commonly referred to as edge computing. Applying edge computing to the camera traps enables the use of ML in environments with slow or non-existent network accesss since their functionality does not rely on the need for connectivity. This project shows the feasibility of running machine learning algorithms for the purpose of species identification on low-cost hardware with similar power to what is commonly found in edge and IoT devices, achieving real-time performance and maintaining high energy efficiency sufficient for more than 12 hours of runtime on battery power. Accuracy results were mixed, indicating the need for more tailor-made network models for performing this task and the importance of high quality images for classification.
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Liu, Yinling. "Conception et vérification du système d'Information pour la maintenance aéronautique." Thesis, Lyon, 2019. http://www.theses.fr/2019LYSEI133.
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Le soutien opérationnel est l’un des aspects les plus importants pour la maintenance aéronautique. Il vise essentiellement à fournir un portefeuille de services permettant d’implémenter la maintenance avec un niveau élevé d’efficacité, de fiabilité et d’accessibilité. L’une des principales difficultés du support opérationnel est qu’il n’existe pas de plate-forme intégrant tous les processus de maintenance des avions afin de réduire les coûts et d’améliorer le niveau de service. Il est donc nécessaire de réaliser un système autonome de maintenance des avions dans lequel toutes les informations de maintenance peuvent être collectées, organisées, analysées et gérées de manière à faciliter la prise de décision. Pour ce faire, une méthodologie innovante a été proposée, qui concerne la modélisation, simulation, vérification formelle et analyse des performances du système autonome mentionné. Trois axes ont été abordés dans cette thèse. Premier axe concerne la conception et simulation d'un système autonome pour la maintenance aéronautique. Nous proposons une conception innovante d'un système autonome prenant en charge la prise de décision automatique pour la planification de la maintenance. Deuxième axe vise la vérification de modèles sur des systèmes de simulation. Nous proposons une approche plus complète de la vérification des comportements globaux et des comportements opérationnels des systèmes. Troisième axe porte sur l'analyse de la performance des systèmes de simulation. Nous proposons une approche consistant à combiner un système de simulation à base d’agent avec une approche « Fuzzy Rough Nearest Neighbor », afin de mettre en œuvre la classification et prévision efficaces des pannes pour la maintenance des avions avec des données manquantes. Finalement, des modèles et systèmes de la simulation ont été proposés. Des expérimentations de la simulation illustrent la faisabilité de l’approche proposéeOperational support is one of the most important aspects of aeronautical maintenance. It aims to provide a portfolio of services to implement maintenance with a high level of efficiency, reliability and accessibility. One of the major difficulties in operational support is that there is no platform that integrates all aircraft maintenance processes in order to reduce costs and improve the level of service. It is therefore necessary to build an autonomous aircraft maintenance system in which all maintenance information can be collected, organized, analyzed and managed in a way that facilitates decision-making. To do this, an innovative methodology has been proposed, which concerns modelling, simulation, formal verification and performance analysis of the autonomous system mentioned. Three axes were addressed in this thesis. The first axis concerns the design and simulation of an autonomous system for aeronautical maintenance. We offer an innovative design of an autonomous system that supports automatic decision making for maintenance planning. The second axis is the verification of models on simulation systems. We propose a more comprehensive approach to verifying global behaviours and operational behaviours of systems. The third axis focuses on the analysis of the performance of simulation systems. We propose an approach of combining an agent-based simulation system with the “Fuzzy Rough Nearest Neighbor” approach, in order to implement efficient classification and prediction of aircraft maintenance failures with missing data. Finally, simulation models and systems have been proposed. Simulation experiments illustrate the feasibility of the proposed approach
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Hyde, Janet Catherine. "An investigation into the use of Visual Technology for the Autonomous Learning of mathematics (VITALmaths) video clips through the medium of cell phones in the teaching of mathematics in selected South African Grade 9 classes: a case study." Thesis, Rhodes University, 2012. http://hdl.handle.net/10962/d1003500.
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This qualitative study examines the use of Visual Technology for the Autonomous Learning of mathematics (VITALmaths) video clips in three Grade 9 classrooms in the Eastern Cape, South Africa, two of which are in well-resourced ex-Model C schools and one in a semi-rural township school. The rapid development of mobile technology, especially in Africa, has opened up previously unexplored avenues in economy, communication and education (Aker & Mbiti, 2010), with a number of mobile learning initiatives being launched in South Africa (Botha & Ford, 2007; Vosloo & Botha, 2009). The VITALmaths project was developed collaboratively between the University of Applied Sciences Northwestern Switzerland and Rhodes University in South Africa (Linneweber-Lammerskitten, Schäfer and Samson, 2010). As the main platform for dissemination of the video clips is the cell phone, the study looked at the various aspects involved in the use of cell phones by learners in the classroom, as well as the incorporation of the clips into the teaching of three teachers. Consideration was given to whether or not the clips assisted the teachers in teaching, as well as whether or not they encouraged further exploration. The study was divided into six stages during which data was collected and analysed using an interpretive approach throughout. Data collection methods included semistructured interviews, questionnaires, observation, journals and reflective essays. The study revealed the participating teachers, having incorporated the clips into several lessons, found that these had a meaningful effect on their teaching practice, as well as on the engagement of the learners in the lessons. The majority of the learners involved in the study had access to cell phones, either their own or borrowed, and were able to download the video clips onto their phones from the website (www.ru.ac.za/vitalmaths). A number of learners found that the clips helped them find examples of specific mathematical concepts outside of the classroom, thus leading to further enquiry and exploration, while several learners downloaded and viewed additional clips. Overall findings showed that the VITALmaths video clips could be incorporated into teaching with relative ease.
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Razghandi, Khashayar [Verfasser], Claudia [Akademischer Betreuer] Fleck, Ingo [Akademischer Betreuer] Burgert, and Manfred [Akademischer Betreuer] Wagner. "Passive hydro-actuated unfolding of ice plant seed capsules as a concept generator for autonomously deforming devices / Khashayar Razghandi. Gutachter: Ingo Burgert ; Claudia Fleck ; Manfred Wagner. Betreuer: Claudia Fleck." Berlin : Technische Universität Berlin, 2015. http://d-nb.info/1070580570/34.
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Basaran, Dilek. "Design, Production And Development Of Mini/micro Robots To Form A Cooperative Colony." Master's thesis, METU, 2003. http://etd.lib.metu.edu.tr/upload/1058874/index.pdf.
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Design, production and development of individual mini/micro robots and then formation of their cooperative colony are the main topics of this thesis. The produced mini/micro robots are as small and light as possible. In addition, they are multifunctional (programmable), flexible and intelligent while maintaining a very low production cost. Mini/micro robots, called MinT-DB series are able to communicate with each other to work cooperatively. Moreover, these robots can be the basis for the future studies considering the application of artificial intelligence and modeling of live colonies in the nature.
Traditional design, production and assembly techniques have been used widely up to now. However, none of them were related with the mini/micro scale. Therefore, this thesis can help people in understanding the difficulties of the design, production, and assembly of the mini/micro systems under the light of the reported science.
In this thesis, instead of examining a specific application field of mini/micro robotic systems, a technology demonstrative work is carried out. Therefore, this thesis contributes to the mini/micro robotic technology, which is also very new and popular in today’
s world, with the robots having the dimensions of 7.5x6x6 cm.
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Choi, Young Sang. "A study of human-robot interaction with an assistive robot to help people with severe motor impairments." Diss., Atlanta, Ga. : Georgia Institute of Technology, 2009. http://hdl.handle.net/1853/29701.
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Thesis (Ph.D)--Industrial and Systems Engineering, Georgia Institute of Technology, 2010.Committee Chair: Kemp, Charles; Committee Member: Glass, Jonathan; Committee Member: Griffin, Paul; Committee Member: Howard, Ayanna; Committee Member: Thomaz, Andrea. Part of the SMARTech Electronic Thesis and Dissertation Collection.
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Jaume, Bennasar Andrés. "Las nuevas tecnologías en la administración de justicia. La validez y eficacia del documento electrónico en sede procesal." Doctoral thesis, Universitat de les Illes Balears, 2009. http://hdl.handle.net/10803/9415.
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La tesis se encarga de analizar, por un lado, la integración y el desarrollo de las nuevas tecnologías en la Administración de Justicia; y, por otro, los parámetros que constituyen la validez y eficacia del documento electrónico. La primera cuestión se centra en la configuración de los Sistemas de Información de la Oficina Judicial y del Ministerio Fiscal, así como de la informatización de los Registros Civiles, donde el art. 230 LOPJ es la pieza clave. Se estudian sus programas, aplicaciones, la videoconferencia, los ficheros judiciales y las redes de telecomunicaciones que poseen la cobertura de la firma electrónica reconocida, donde cobran gran relevancia los convenios de colaboración tecnológica. La digitalización de las vistas quizá sea una de las cuestiones con más trascendencia, teniendo en cuenta que el juicio es el acto que culmina el proceso. Aunque no todos los proyectos adoptados en el ámbito de la e.justicia se han desarrollado de forma integral, ni han llegado a la totalidad de los órganos judiciales. El objetivo final es lograr una Justicia más ágil y de calidad, a lo cual aspira el Plan Estratégico de Modernización de la Justicia 2009-2012 aprobado recientemente.
En referencia a la segunda perspectiva, no cabe duda que el Ordenamiento jurídico y los tribunales, en el ámbito de la justicia material, otorgan plena validez y eficacia al documento electrónico. Nuestra línea de investigación se justifica porque cada vez son más los procesos que incorporan soportes electrónicos de todo tipo, ya sea al plantearse la acción o posteriormente como medio de prueba (art. 299.2 LEC). Entre otros temas examinamos el documento informático, la problemática que rodea al fax, los sistemas de videograbación y el contrato electrónico.
La tesi s'encarrega d'analitzar, per una part, la integració i el desenvolupament de les noves tecnologies dins l´Administració de Justícia; i, per l'altra, els paràmetres que constitueixen la validesa i l'eficàcia del document electrònic.
La primera qüestió es centra en la configuració dels Sistemes d´Informació de l´Oficina Judicial i del Ministeri Fiscal, així com de la informatització dels Registres Civils, on l'art. 230 LOPJ es la peça clau. S'estudien els seus programes, aplicacions, la videoconferència, el fitxers judicials i les xarxes de telecomunicacions que tenen la cobertura de la firma electrònica reconeguda, on cobren gran rellevància els convenis de col·laboració tecnològica. La digitalització de les vistes tal vegada sigui una de les qüestions amb més transcendència, tenint amb compte que el judici es l'acte que culmina el procés. Però no tots el projectes adoptats en l'àmbit de la e.justicia s'han desenvolupat d'una manera integral ni han arribat a la totalitat dels òrgans judicials. L'objectiu final es assolir una Justícia més àgil i de qualitat, al que aspira el Pla Estratègic de Modernització de la Justícia 2009-2012 aprovat recentment.
En referència a la segona perspectiva, no hi ha dubte que l´Ordenament jurídic i els tribunals, en l'àmbit de la justícia material, donen plena validesa i eficàcia al document electrònic. La nostra línia d'investigació es justifica perquè cada vegada son més el processos que incorporen suports electrònics de tot tipus, ja sigui quant es planteja l'acció o posteriorment como a medi de prova (art. 299.2 LEC). Entre altres temes examinem el document informàtic, la problemàtica que envolta al fax, els sistemes de videogravació i el contracte electrònic.
The thesis seeks to analyse, on the one hand, the integration and development of the new technologies in the Administration of Justice; and, on the other, the parameters which constitute the validity and efficiency of the electronic document.
The first question centres on the configuration of the Information Systems of the Judicial Office and the Public Prosecutor, as well as the computerisation of the Civil Registers, where the art. 230 LOPJ it's the part key. Their programmes, applications, the Video Conferencing, the judicial registers and the telecommunication networks which are covered by the recognised electronic signatures, are studied, where the agreements on technological collaboration gain great relevance. The digitalisation of evidence might perhaps be one of the questions with most consequence, bearing in mind that the judgment is the act by which the process is culminated. Although not all the projects adopted within the compass of e.justice have developed completely nor have reached all the judicial organs. The final objective is to achieve an agile, quality Justice, to which the recently approved Strategic Plan for the Modernisation of Justice aspires.
With reference to the second perspective, there is no doubt that the juridical Ordinance and the tribunals within the compass of material justice grant full validity and efficacy to the electronic document. Our line of investigation is justified because there are more and more processes which are sustained by electronic supports of all kinds, whether it be at the establishment of the action or later, as a proof of it (art. 299.2 LEC). Amongst other things, we examine the computerised document, the problems which surround the fax, the systems for video recording and the electronic contract.
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Yeh, Ting Hao, and 葉庭豪. "A Mechanism for Autonomous Multi-Group Formation and Communication in Wi-Fi Direct Device to Device Networks." Thesis, 2016. http://ndltd.ncl.edu.tw/handle/fg4x3p.
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Wang, Meng Chien, and 王孟謙. "A Study on the Autonomous Driving Device in the Era of Internet of Vehicle." Thesis, 2018. http://ndltd.ncl.edu.tw/handle/gy6vgb.
Full textAbstract:
碩士國立臺北科技大學
管理學院EMBA大上海專班
106
In the future intelligent transportation, the Internet of cars will play an important role, and it will also bring about an important revolution to the needs of the future life on the human trip. First, in this paper, we introduce the promotion process of the Internet of things, and then promote the business opportunities and blue sea of the human travel demand, and give the main direction of the paper. On the issue of the Internet of vehicles, this paper first introduces the concept of car networking, and its overall development, and then describes the architecture and key technologies of the car network, and analyzes the specific applications related to life, and takes advantage of the related Seminar on car networking to focus on the relevant discussions and experts and industry predecessors. The problem is discussed in depth, and the discussion and consultation process are carried out to demonstrate the content and point of view. The final feasible practice and suggestions are extracted. Finally, the technical application of the automatic driving system of the think Federation car is given, and the key and hidden defects and problems in the application of these technologies are also analyzed. The suggestions and feasible directions for future application and connection of this technology will be the end of this thesis.
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Lima, Rodrigo Olival. "Autonoumous Nervous System biosignal processing via EDA and HRV from a wearable device." Master's thesis, 2018. http://hdl.handle.net/10362/59608.
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The assessment of changes in the autonomous nervous system (ANS) with certain diseases and
pathologies conditions, has been demonstrated to have important prognostic and diagnostic
value, so delineating the role of autonomous activity is important to prevent health diseases.
There are many approaches to directly measure the sympathetic and parasympathetic nervous
system, although, most of themare invasive and unable to provide continuous monitoring,
leading to inaccurate assessment of the autonomous nervous system.
Heart rate variability (HRV) and Electrodermal activity (EDA) are presented has noninvasive
methods to assess the ANS, by computing the spectral analysis of both HRV and EDA biosignals.
The combination of these signals is necessary to correctly measure the activity of the sympathetic
and parasympathetic system, due to the fact that frequency analysis of HRV only provides
the level of unbalance between these two systems, while EDA reflects only activity from the
sympathetic system. ANS biosignal processing via HRV and EDA from a wearable device was
studied in this thesis, in order to provide continuous monitoring. A wearable device is the ideal
solution, as HRV can be calculated with photoplethysmography signals from the wrist and EDA
from the fingers, providing wireless and continuous monitoring of the subjects.
The extraction of the HRV and EDA features, that describe the activity of the sympathetic
and parasympathetic system, were obtained by submitting the subjects to a mental arithmetic
stress test, and then compared to the baseline values, in order to verify changes in the autonomous
nervous system between the two situations.
The distinct response to stress for the subjects was then predicted usingmachine-learning
classification mechanisms, with the ability to predict how the subject will respond when submitted
to a situation of stress, using only time-domain features, instead of frequency-domain
features, which reduces the time needed to performthe classification.
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Lindt, Melissa. "Consumer attitudes towards new underlying concepts in autonomous driving cars : instrumental versus experiential activity potentials." Master's thesis, 2018. http://hdl.handle.net/10400.14/25637.
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Autonomous driving is one of four major trends that will substantially shape the future automotive industry. The increasing importance of software-driven products in this sector, may drive technology companies to enter the market of autonomous vehicles. As the vehicle drives itself, drivers will gain additional free time that may be used otherwise. This additional free time is the basis for new in-car activities which will provide the opportunity to spend the commute time meaningfully. This empirical study investigates consumers’ attitudes towards such in-car activities. Therefore, various possibilities were clustered into experiential, such as entertainment or sleeping, and instrumental, such as communication or productivity, in-car activities. Findings indicated a general consumer interest and a higher rating of instrumental activities compared to experiential activities. Furthermore, it was found that with increasing free time the interest in instrumental activities decreases. The study revealed that consumers with a high willingness to adopt new technologies stated a higher receptiveness for instrumental activities. Similarly, persons with a higher willingness of technology adaptation consider purchasing an autonomous driving car from technology companies entering the market. Traditional car brands need to consider changing market structures and consumer needs to defend their position which might be threatened by new market players. Considering the increasing importance of technology experiences within the vehicle, such in-car activities may represent a crucial driver for success and customer satisfaction.A condução autónoma é uma das quatro tendências principais que irão definir substancialmente a industria automóvel. A crescente importância de produtos baseados em software neste setor pode levar as empresas de tecnologia a entrar no mercado de veículos autónomos. À medida que o veículo se movimenta, os condutores ganham tempo livre que pode ser usado de outra forma. Esse tempo livre adicional é a base para novas atividades no carro que proporcionarão a oportunidade de gastar o tempo de viagem de maneira significativa. Este estudo empírico investiga as atitudes dos consumidores em relação a tais atividades no carro. Deste modo, várias possibilidades foram agrupadas em experiência, como entretenimento ou sono, e instrumental, como comunicação ou produtividade, atividades no carro. Os resultados indicaram um interesse geral do consumidor e uma classificação mais alta de atividades instrumentais em comparação com atividades experienciais. Além disso, constatou-se que, com o aumento do tempo livre, o interesse pelas atividades instrumentais diminui. O estudo revelou que os consumidores com maior disposição para adotar novas tecnologias apresentaram maior receptividade para atividades instrumentais. Da mesma forma, pessoas com maior disposição de adaptação tecnológica consideram a compra de um carro de condução autónoma de empresas de tecnologia que entraram no mercado. As marcas de carros tradicionais precisam de reconsiderar a possibilidade de mudar as estruturas de mercado e as necessidades dos consumidores para defender sua posição, que pode ser ameaçada pelos novos participantes do mercado. Considerando a crescente importância das experiências tecnológicas no veículo, essas atividades no carro podem representar um fator crucial para o sucesso e a satisfação do cliente.
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JARMAROVÁ, Lenka. "Příprava kampaně k propagaci zařízení autonomní detekce a signalizace v rámci preventivně výchovné činnosti na úseku požární ochrany." Master's thesis, 2013. http://www.nusl.cz/ntk/nusl-154714.
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The preparation of campaign promoting autonomous detection and signaling devices within activities of preventive education in section of fire protection We can come across fires of buildings designed for living every day, therefore is very important to try to prevent them. The most accessible way is the installation of autonomous detection and signaling devices, which is currently obligatory to all newly designed and built houses. These devices detect emerging fire, subsequently inform about possible threat and at the same time they allow enough time for the population rescue. To achieve the main aims of thesis, it was needed to study specialized literature and write theoretical part which explains basic concepts connected to the topic, defines the dangers in the place of fire, followed by classification of toxic substances which are released during the fire and finally describes autonomous detection and signaling devices. The integral part contains the graphic layouts focused on the comparison of statistical data from 2001 till 2011, mostly tracking fires and number of killed and injured people during the household fires, which is compared to the number of killed and injured people and fires in general. There was made questionnaire for 50 public respondents from the city Zábřeh after completing the theoretical part. These respondents were chosen on purpose in cooperation with the fire station Zábřeh, which is part of Fire Rescue Service of Olomouc district. We defined hypothesis: The knowledge of Zábřeh population about own life and property protection against the fire are insufficient. The hypothesis was defined using descriptive and mathematical statistics. However, our hypothesis wasn´t confirmed so we can consider awareness of Zábřeh population to be sufficient but not excellent. Therefore, there is still need to increase their legal responsibility. The practical part further includes the analysis of questionnaire answers, which is aimed to evaluate the accuracy of answered questions. Last but not least, the thesis presents the set of promotional campaigns which are ordered by the ability to properly effect on the population via web pages, daily press, TV broadcast or printed materials. The most wanted way would be TV campaign, which is unfortunately expensive and time-consuming; therefore, it seems to be the best option to create web pages or printed material aimed for general public. The both promotional campaigns should be provided by Ministry of the Interior - general directorate of Fire Rescue Service of Czech Republic.
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Callaway, Robert K. "An autonomous circuit for measurement of photovoltaic devices parameters." Thesis, 1986. http://hdl.handle.net/10945/21691.
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Aggarwal, Saurabh. "Content Distribution in Social Groups." Thesis, 2014. http://hdl.handle.net/2005/3036.
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We study Social Groups consisting of self-interested inter-connected nodes looking for common content. We can observe Social Groups in various socio-technological networks, such as Cellular Network assisted Device-to-Device communications, Cloud assisted Peer-to-Peer Networks, hybrid Peer-to-Peer Content Distribution Networks and Direct Connect Networks. Each node wants to acquire a universe of segments at least cost. Nodes can either access an expensive link to the content distributor for downloading data segments, or use the well-connected low cost inter-node network for exchanging segments among themselves.
Activation of an inter-node link requires cooperation among the participating nodes and reduces the cost of downloading for the nodes. However, due to uploading costs, Non-Reciprocating Nodes are reluctant to upload segments, in spite of their interest in downloading segments from others. We define the Give-and-Take (GT) criterion, which prohibits non-reciprocating behaviour in Social Groups for all nodes at all instants. In the “Full Exchange” case studied, two nodes can exchange copies of their entire segment sets, if each node gains at least one new segment from the other.
Incorporating the GT criterion in the Social Group, we study the problem of downloading the universe at least cost, from the perspective of a new node having no data segments. We analyze this NP-hard problem, and propose algorithms for choosing the initial segments to be downloaded from the content distributor and the sequence of nodes for exchange. We compare the performance of these algorithms with a few existing P2P downloading strategies in terms of cost and running time.
In the second problem, we attempt to reduce the load on the content distributor by choosing a schedule of inter-node link activations such that the number of nodes with the universe is maximized. Link activation decisions are taken by a central entity, the facilitator, for achieving the social optimum. We present the asymptotically optimal Randomized algorithm. We also present other algorithms, such as the Greedy Links algorithm and the Polygon algorithm, which are optimal under special scenarios of interest. We compare the performances of all proposed algorithms with the optimal value of the objective. We observe that computationally intensive algorithms exhibit better performance.
Further, we consider the problem of decentralized scheduling of links. The decisions of link activations are made by the participating nodes in a distributed manner. While conforming to the GT criterion for inter-node exchanges, each node's objective is to maximize its utility. Each node tries to find a pairing partner by preferentially exploring nodes for link formation. Unpaired nodes choose to download a segment using the expensive link with Segment Aggressiveness Probability (SAP). We present linear complexity decentralized algorithms for nodes to choose their best strategy. We present a decentralized randomized algorithm that works in the absence of the facilitator and performs close to optimal for large number of nodes. We define the Price of Choice to benchmark performance of Social Groups (consisting of non-aggressive nodes) with the optimal. We evaluate the performance of various algorithms and characterize the behavioural regime that will yield best results for node and Social Group as well.
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(8771336), Rafatul Faria. "Autonomous Probabilistic Hardware for Unconventional Computing." Thesis, 2020.
Find full textAbstract:
In this thesis, we have proposed a new computing platform called probabilistic spin logic (PSL) based on probabilistic bits (p-bit) using low barrier nanomagnets (LBM) whose thermal barrier is of the order of a kT unlike conventional memory and spin logic devices that rely on high thermal barrier magnets (40-60 kT) to retain stability. p-bits are tunable random number generators (TRNG) analogous to the concept of binary stochastic neurons (BSN) in artificial neural network (ANN) whose output fluctuates between a +1 and -1 states with 50-50 probability at zero input bias and the stochastic output can be tuned by an applied input producing a sigmoidal characteristic response. p-bits can be interconnected by a synapse or weight matrix [J] to build p-circuits for solving a wide variety of complex unconventional problems such as inference, invertible Boolean logic, sampling and optimization. It is important to update the p-bits sequentially for proper operation where each p-bit update is informed of the states of other p-bits that it is connected to and this requires the use of sequencers in digital clocked hardware. But the unique feature of our probabilistic hardware is that they are autonomous that runs without any clocks or sequencers.To ensure the necessary sequential informed update in our autonomous hardware it is important that the synapse delay is much smaller than the neuron fluctuation time.
We have demonstrated the notion of this autonomous hardware by SPICE simulation of different designs of low barrier nanomagnet based p-circuits for both symmetrically connected Boltzmann networks and directed acyclic Bayesian networks. It is interesting to note that for Bayesian networks a specific parent to child update order is important and requires specific design rule in the autonomous probabilistic hardware to naturally ensure the specific update order without any clocks. To address the issue of scalability of these autonomous hardware we have also proposed and benchmarked compact models for two different hardware designs against SPICE simulation and have shown that the compact models faithfully mimic the dynamics of the real hardware.
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Leiding, Benjamin. "The M2X Economy – Concepts for Business Interactions, Transactions and Collaborations Among Autonomous Smart Devices." Doctoral thesis, 2019. http://hdl.handle.net/21.11130/00-1735-0000-0005-12E4-5.
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Ho, Kuan-Lin, and 何冠霖. "Guidance of an Autonomous Vehicle for Security Patrolling in Park Areas Using Multiple Onboard KINECT Devices." Thesis, 2013. http://ndltd.ncl.edu.tw/handle/91647187974372843950.
Full textAbstract:
碩士國立交通大學
多媒體工程研究所
101
A vision-based autonomous vehicle system equipped with KINECT devices for security patrolling on sidewalks in outdoor environments is proposed. A small-size vehicle with three onboard KINECT devices is designed to build the system. At first, a learning procedure is proposed for a trainer to guide the vehicle to extract specific features, including navigation path, color/depth information, pre-selected landmark objects, and vehicle location with respect to the landmark. Next, a strategy of vehicle navigation with a line-following capability is proposed, by which the vehicle may be guided to navigate according to the node data of the learned path, detect along-path landmarks using SURFs, and match the features with the learned data based on the measures of contrast difference and Euclidean distance. In addition, a vehicle location estimation technique for path correction utilizing the landmark matching result is proposed, which is based on the use of an ICP algorithm with the depth information as input according to the criterion of minimum MSE. Furthermore, techniques of ramp and curb-line detection have also been proposed, both for use to guide the vehicle safely on the path as well as to provide environment features and adjust the vehicle orientation. Good experimental results show the flexibility and feasibility of the proposed methods for the application of security patrolling in outdoor environments.
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Chou, Kuo-Yu, and 周國裕. "Reliability of VLSI-Level Chips, Active Devices under CMOS I/O Pads, and Autonomous Design of Technology Intellectual Property." Thesis, 2002. http://ndltd.ncl.edu.tw/handle/14781603578601567337.
Full textAbstract:
博士國立交通大學
電子工程系
91
This dissertation presents the modeling and characterization of reliability of the large-die-size VLSI-level chip in two different back-end CMOS technologies, generic 0.18 $\mu m$ six-level AlCu-hydrosilsesquioxane (HSQ) and specific dual-damascene Cu-fluorinated SiO$_{2}$ (FSG). The impacts of area and location of a chip, the material from which it is encapsulated, the geometry of the test structures, accelerated stressing operations on the reliability testing are investigated. On the other hand, a novel method, active devices placed under CMOS I/O pads, has been stringently proven to be feasible in this dissertation. Additionally, new-developed programming language, technology independent description language (TIDL), relates to a layout method for autonomous design of technology intellectual property. Using a special-designed large-die-size test chip with a variety of the sensitive top two metal test structures, The shape parameter in AlCu/HSQ back-end technology is the same for temperature cycling (TC) and thermal shock (TS) reliability testing induced stresses. The same brittle fracture failure mechanism occurs in each case since the Paris Law exponent lies in the range for brittle fracture. The failures induced by both TC and TS operations are independent of the number of sites in the chip corner. The area of the chip and the geometry of the test structure can affect the magnitude of the intrinsic stress. Such intrinsic stress directly influences the stress, changing the $N_{63}$ of the data lines in the Weibull plot. Additionally, CTE mismatches induced by interactions between compound materials and the silicon chip also alter the magnitude of the intrinsic stress, impacting S to result in the different $N_{63}$ of the data lines in the Weibull plot. Finally, test chips fabricated in generic 0.18 $\mu m$ six-level AlCu/HSQ technology and specific dual damascene Cu/FSG technology just for top two-level metal differ significantly in the failure rate during tests of the reliability of the chip assembly. The results show that the mechanical and electrical performance of the packaged test chip depends strongly on the back-end process, which thus greatly impacts the failure distribution and the failure mechanism. This thesis examines active devices, including electrostatic discharge protection (ESD) device and ring-oscillator circuit, under CMOS I/O pads. The 1.2 $\mu m$ aluminum metal film is deposited on the 1.0 $\mu m$ top most copper metal layer for an effective bonding mechanism stressing buffer layer to protect active devices under CMOS I/O pads. The high current I-V curve measured in the second breakdown trigger point (V$_{t2}$, I$_{t2}$) of ESD protection devices under various metal level stack structures, shows that (i) I$_{t2}$ depends very weakly on the number of metal levels used, as expected given specific junction power dissipation criteria; and (ii) V$_{t2}$ increases with the number of metal level stacks of I/O pads because of increased dynamic impedance due to the presence of more metal levels, as clarified by a simple $RC$ model. Moreover, no noticeable degradation in the speed of the ring-oscillator circuit, as measured for a variety of test structures subjected to bonding mechanical stress, thermal stress by temperature cycling and $dc$ electrical stress by transmission line pulse, as well as $ac$ electrical stress by capacitive-coupling experiments. Accordingly, active devices under CMOS I/O pads is independent of bonding pad metal level structures. The programming approach using a new-developed syntax, technology independence description language, for autonomous design of technology intellectual property (TIP) in submicron, deep submicron, ultra deep submicron, nanoscale and beyond CMOS process technologies has been realized in this dissertation. Design of TIPs based on TIDL syntax models variables of TIPs in a descriptive approach, independent of technology and design rules change, and parameterizes TIP creation so that TIDL-programmed TIPs can be built in the previous well-proven technology knowledge, parameters of device simulation profile, and embedded new technology know-how, process constraints and checking ranges, physical design rules and reliability description. Such TIPs satisfy semiconductor technology development and manufacturing with autonomously instant revisability, portability, reusability, compatibility, and standardizability, and alleviate the error-prone, time-consuming and expensive development of TIPs created by a free-hand layout.
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Ferreira, André Filipe Gonçalves. "Development of autonomous and reusable devices for 3d localization and communication, integrated into protective clothing for high temperatures and in unstructured environments." Doctoral thesis, 2018. http://hdl.handle.net/1822/55904.
Full textAbstract:
Philosophy Doctorate Thesis Electronic and Computers EngineeringThe availability of a reliable and accurate indoor positioning system (IPS) for emergency responders during on-duty missions is regarded as an essential tool to improve situational awareness of both the emergency responders and the incident commander. This tool would facilitate the mission planning, coordination and accomplishment, as well as, decrease the number of on-duty deaths. Due to the absence of global positioning system (GPS) signal in indoor environments, many other signals and sensors have been proposed for indoor usage. However, the challenging scenarios faced by emergency responders imply explicit restrictions and requirements on the design of an IPS, making the use of some technologies, techniques, and methods inadequate on these scenarios. Alongside with the position information, monitoring physiological and environmental parameters is also vital to improve the emergency responders’ safety. So, to monitor all these parameters, a cyber -physical system (CPS), designated by PROTACTICAL CPS, is proposed. This system aims to improve the decision making at several emergency responders’ operation stages (e.g., emergency responder, teams, and incident commander), and is capable of detecting, in real-time, life-threatening scenarios. Different sensor nodes, called node-PROTACTICAL, are integrated into a personal protective equipment (PPE) to acquire the desired parameters. Two wireless networks are used to send the acquired information to the incident commander, a wireless body sensor network (WBSN) and an Ad-Hoc network. The former relies on the ZigBee technology and is responsible for managing the communication with the nodes-PROTACTICAL. On the other hand, the Ad-Hoc network relies on Wi-Fi technology and is responsible for the communication between the PPE and the incident commander. For the estimation of the emergency responder’s position, a hybrid IPS integrated into the PROTACTICAL CPS is proposed. This IPS is based on an indirect remote positioning topology and is composed of three modules (radio signal-based, IMU-based, and data fusion). The present work focuses essentially on the design and evaluation of an IPS for emergency responders. This involves the definition of the specific requirements, selection of technologies, evaluation of positioning methods and their combination to overcome the limitations imposed by the emergency responders’ scenarios. For the radio signal-based module, the ultra-wideband (UWB) technology was selected because of its immunity to noise and high accuracy of the ranging measurements. A measurement campaign was carried out to assess the performance of the ranging measurements under different propagation conditions and, the worst scenario occurs when the signal is blocked by the human body. So, non-line-ofsight (NLOS) identification and error mitigation algorithms are proposed to reduce the ranging measurement error under NLOS conditions. Then, four positioning algorithms are compared and evaluated under different conditions (e.g., environments with different propagation conditions, static and dynamic target, and with or without NLOS influence due to the human body). The previous study confirmed some weaknesses that can be compensated by another positioning method and thus a pedestrian dead reckoning (PDR) system based on foot-mounted inertial sensors is proposed and evaluated. This system is capable of, simultaneously, estimating the distance travelled and the emergency responder’s attitude. An extended Kalman filter (EKF) aided by zero velocity updates (ZUPT) is implemented to refine the emergency responder’s position and heading. Finally, a data fusion algorithm based on a Kalman filter is proposed to combine the UWB and PDR estimates. The data fusion algorithm is assisted by a decision-making algorithm that rejects the UWB position estimation when two or more ranging measurements are in NLOS. The performance of the data fusion method is assessed with three UWB positioning algorithms.
A existência de um sistema de localização indoor (IPS) confiável e preciso que possa ser utilizado por equipas de emergência durante as suas missões é considerado uma ferramenta essencial para melhorar a perceção da situação pelas equipas de emergência e pelo comando. Esta ferramenta facilitaria o planeamento, coordenação e realização da missão, além de diminuir o número de acidentes graves e mesmo fatais. Devido à ausência de sinal do sistema de posicionamento global (GPS) em muitas situações, muitas outras tecnologias e sensores foram propostos para uso em edifícios e ambientes sem cobertura GPS. No entanto, os cenários enfrentados pelas equipas de emergência impõem restrições e requisitos específicos sobre a conceção do IPS, tornando o uso de algumas tecnologias, técnicas e métodos inadequados nesses casos. Juntamente com a informação da posição, a monitorização de parâmetros fisiológicos e ambientais também é importante para melhorar a segurança das equipas de emergência. Assim, para monitorizar todos esses parâmetros, é proposto um cyber-physical system (CPS), designado por PROTACTICAL CPS. Este sistema visa melhorar a tomada de decisões nos vários estágios da missão (por exemplo, ao nível do bombeiro, das equipas e do comando) e é capaz de detetar, em tempo real, cenários que ameaçam a vida das equipas de emergência. Diferentes nós sensores, chamados nó-PROTACTICAL, são integrados em um equipamento de proteção pessoal (EPI) para a aquisição dos parâmetros desejados. A informação adquirida é enviada ao comandante através de duas redes sem fios, uma wireless body sensor network (WBSN) e uma rede Ad-Hoc. A primeira baseia-se na tecnologia ZigBee e é responsável por assegurar a comunicação com os nós-PROTACTICAL. Por outro lado, a rede Ad-Hoc depende da tecnologia Wi-Fi e é responsável pela comunicação entre o EPI e o comando. Para a localização indoor, é proposto um IPS híbrido integrado no PROTACTICAL CPS. Este IPS é baseado na topologia de posicionamento remoto indireto e é composto por três módulos (baseado em sinal de rádio, baseado em IMU e fusão de dados). O presente trabalho incide no design e avaliação de um IPS para equipas de emergência. Isso envolve a definição dos requisitos específicos, seleção das tecnologias, avaliação dos algoritmos de localização e a sua combinação de modo a superar as limitações impostas pelos cenários das equipas de emergência. Para o módulo baseado em sinal de rádio, a tecnologia ultra-wideband (UWB) foi selecionada devido à sua imunidade ao ruído e precisão das medições de distância. Foi realizado um conjunto de testes para avaliar o desempenho destas medições em diferentes condições de propagação, verificando-se que o pior cenário ocorre quando o sinal é bloqueado pelo corpo humano. Para ultrapassar esta dificuldade, é proposto um algoritmo para a identificação das medições de distância obtidas sem linha de visão (NLOS) e assim mitigar o erro das respetivas medições. De seguida, quatro algoritmos de posicionamento são comparados e avaliados sob diferentes condições (p.e., ambientes com diferentes condições de propagação, alvo estático e dinâmico e com ou sem influência do NLOS devido ao corpo humano). O estudo anterior confirmou algumas fragilidades que podem ser compensadas por outro método de localização e, desse modo, é proposto e avaliado um sistema de pedestrian dead reckoning (PDR) baseado em sensores inerciais montados no pé. Este sistema é capaz de estimar a distância percorrida e a direção do movimento. Um filtro Kalman estendido (EKF) auxiliado por atualizações de velocidade zero (ZUPT) é implementado para refinar a posição e a direção do movimento do utilizador. Finalmente, propõe-se um algoritmo de fusão de dados baseado no filtro de Kalman para combinar as estimativas de posição provenientes dos subsistemas UWB e PDR. O algoritmo de fusão de dados é assistido por um algoritmo de decisão que rejeita a estimativa da posição UWB quando duas ou mais medidas de variação estão em NLOS. O desempenho do método de fusão de dados é avaliado com três algoritmos de posicionamento UWB.
Fundação para a Ciência e a Tecnologia (FCT), for the financial support under the PhD scholarship SFRH/BD/91477/2012. I would also like to acknowledge the doctoral program in Electronics and Computer Engineering for supporting this work.