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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
91

Implantation dans le matériel de fonctionnalités temps-réel dans une caméra intelligente ultralégère spécialisée pour la prise de vue aérienne / Implementation of real-time functionalities in in the hardware of ultra-light intelligent camera specialized for the aerial imaging

Audi, Ahmad 14 December 2017 (has links)
Au cours des dernières années, les drones civils sont devenus un outil intéressant dans la photographie aérienne et dans les travaux de photogrammétrie. Cela a poussé le LOEMI (Laboratoire d’Opto-Electronique, Métrologie et Instrumentation) de l'IGN (Institut National de l'Information Géographique et Forestière) de mettre au point une nouvelle caméra aérienne mieux adaptée pour l'exploitation photogrammétrique et métrologiques des images que les caméras grand public. Cette caméra est composée essentiellement d'un capteur CMOS ``global-shutter'', d'une centrale inertielle IMU, et d'un système sur puce (FPGA + 2 CPUs) pour la gestion de l'acquisition des images. Ce SoC/FPGA ouvre la porte à l'implémentation temps-réel des algorithmes de traitement d'image. Parmi les travaux futurs de l'IGN, on peut distinguer certaines applications qui nécessitent l'acquisition des images aériennes avec un temps d'exposition long, comme par exemple les prises de vue aériennes en bande spectrale étroite et les prises de vue aériennes de nuit. Ce type de prises de vue manifeste un flou de bougé dans les images dû aux mouvements erratiques du drone. Cette thèse consiste en l'implémentation dans la caméra légère de l'IGN d'un algorithme qui permet de remédier ce problème de flou de bougé. La première partie de ce travail a été consacrée au développement de la méthode qui consiste à acquérir plusieurs images avec un temps de pose court, puis utiliser un algorithme de traitement d'image afin de générer une image empilée finale avec l'équivalent d'un temps de pose long. Les paramètres des orientations correctes pour le ré-échantillonnage des images sont obtenus par l'estimation de la transformation géométrique entre la première image et la nième image à partir des points d'intérêts détectés par FAST dans la première image et les points homologues obtenus par corrélation dans les autres images accélérées par les capteurs inertiels intégrés à la caméra. Afin d'accélérer le traitement de calcul de notre algorithme, certaines phases sont accélérées en les implémentant dans le matériel (SoC/FPGA).Les résultats obtenus sur des jeux de tests acquis avec un drone type Copter 1B UAV et la caméra ultra-légère de l'IGN montrent que l'image finale empilée ne présente pas un flou de bougé. Les résultats de temps des différentes phases de l'algorithme montrent aussi que l'exécution de notre algorithme a un temps quasi-nulle. Un des sous-produits intéressants de ces travaux est la ré-étalonnage des capteurs IMU / In the recent years, the civilian UAVs (Unmanned Aerial Vehicles) have become an interesting tool in aerial photography and in photogrammetry. This led the LOEMI (Laboratoire d'Opto-électronique, de Métrologie et d'Instrumentation) team of IGN (Institut National de l'Information Géographique) to design an light-weight digital camera better adapted for exploiting photogrammetry and metrology applications than consumer cameras. This camera consists essentially of a CMOS ``global shutter'' sensor, an inertial measurement unit IMU, and a system on chip (FPGA + 2 CPUs) used originally to acquire image data from the sensor. This SoC/FPGA-based camera opens the door to implement in hardware some real-time image processing algorithms. Night-time surveys and narrow spectral band with imagery are one of the next applications targeted by IGN, this type of applications needs a long-exposure time imagery that usually exhibits a motion blur due to erratic movements of the UAV. This thesis consists in the implementation on the light-weight IGN camera of an alogirithm which makes it possible to remedy this problem of motion blur. The first part of this work was devoted to the development of the method which consists in acquiring several images with a short exposure time and then using an image processing algorithm in order to generate a stacked image with the equivalent of a long-exposure time. To obtain the correct parameters for the resampling of images, the presented method accurately estimates the geometrical relation between the first and the nth image, taking into account the internal parameters and thedistortion of the camera. Features are detected in the first image by the FAST detector, than homologous points on other images are obtained by template matching aided by the IMU sensors. In order to speed up the processing of our algorithm, some phases are accelerated by implementing them in the hardware (SoC / FPGA).The results obtained on real surveys show that the final stacked image does not present a motion blur. The time results of the different phases of the algorithm also show that the execution of the algorithm has a quasi-zero time. One of the interesting byproducts of this work is the recalibration of the IMU sensors
92

Airbourne WiFi Networks Through Directional Antenna: An Experimental Study

Gu, Yixin 05 1900 (has links)
In situations where information infrastructure is destroyed or not available, on-demand information infrastructure is pivotal for the success of rescue missions. In this paper, a drone-carried on demand information infrastructure for long-distance WiFi transmission system is developed. It can be used in the areas including emergency response, public event, and battlefield. The WiFi network can be connected to the Internet to extend WiFi access to areas where WiFi and other Internet infrastructures are not available. In order to establish a local area network to propagate WIFI service, directional antennas and wireless routers are used to create it. Due to unstable working condition on the flying drones, a precise heading turning stage is designed to maintain the two directional antennas facing to each other. Even if external interferences change the heading of the drones, the stages will automatically rotate back to where it should be to offset the bias. Also, to maintain the same flying altitude, a ground controller is designed to measure the height of the drones so that the directional antennas can communicate to each other successfully. To verify the design of the whole system, quite a few field experiments were performed. Experiments results indicates the design is reliable, viable and successful. Especially at disaster areas, it’ll help people a lot.
93

Efecto de la estratificación atmosférica en la distribución vertical de aerosoles segregados por tamaño en la atmósfera de Santiago

Carrasco Carrasco, Paula Daniela 10 1900 (has links)
Seminario de Título entregado a la Universidad de Chile en cumplimiento parcial de los requisitos para optar al Título de Química Ambiental. / A la fecha, 12 de las 15 regiones de Chile conforman zonas saturadas de MP10 y/o MP2.5, lo que deja en evidencia el grave problema ambiental que enfrenta el país. En la actualidad, el monitoreo de la calidad del aire en Santiago, una de las zonas saturadas de Chile, se lleva a cabo a través de 11 estaciones de monitoreo fijas en superficie distribuidas en la Región Metropolitana, las cuales conforman la Red de Monitoreo Automático de la Calidad del Aire y Meteorología (red MACAM). Las mediciones son de carácter superficial y por lo tanto permiten registrar las concentraciones de contaminantes y su variabilidad espacial en dos dimensiones (2D); no obstante, los contaminantes se mueven e interactúan en toda la capa de mezcla conforme lo permiten las condiciones atmosféricas, incluyendo escenarios sinópticos que inducen la transferencia, acumulación y la formación de contaminantes a escalas regionales, lo que es trascendental a la hora de prevenir, controlar y modelar la contaminación atmosférica en tres dimensiones. Con el objetivo de responder a la necesidad de información que existe con respecto a la concentración de aerosoles en altura y el efecto de la estratificación atmosférica sobre su distribución vertical, se analizaron las condiciones de estabilidad atmosférica a través del estudio de perfiles verticales de variables meteorológicas (temperatura, punto de rocío, presión y humedad relativa) y concentración de material particulado segregado por tamaño (n/L y μg/m3), utilizando un monitor continuo de partículas 11-C y sensores acoplados a un vehículo aéreo no tripulado o Drone. Se realizaron cinco campañas de medición que permitieron definir el modo de vuelo en ascenso a velocidad constante como el más apropiado y reproducible y evidenciar el efecto de las zonas de estabilidad sobre la concentración de MP en altura. Se comprobó que la estratificación atmosférica limita el desplazamiento vertical de aerosoles, afectando principalmente y en mayor magnitud las fracciones de mayor tamaño (diámetro entre 1.00 μm y 10.0 μm), cuyas concentraciones en número disminuyen considerablemente luego de una inversión en la mayoría de los casos, esto explica que la fracción más afectada en masa (μg/m3) sea el MP10, ya que son las partículas más gruesas las que más contribuyen en la masa de la muestra. En consecuencia, las partículas del tamaño mencionado disminuyen su contribución en el número total de partículas por litro en altura, siendo ésta la mayor diferencia al comparar la distribución de MP en altura con la distribución de MP en superficie. Finalmente, se clasificaron los aerosoles según su distribución de tamaño en altura y en superficie en dos vuelos seleccionados. Para ambos vuelos, se clasificaron como polidispersos los aerosoles en superficie y se determinó que la clasificación de monodisperso o polidisperso de una muestra de partículas en altura puede deberse tanto a la diferencia de altura de la medición como a la intensidad de la estratificación atmosférica en ambos vuelos. / To date, 12 of the 15 regions of Chile conform saturated zones with MP10 and/or MP2.5, which shows the serious environmental problem facing the country. Currently, the air quality monitoring in Santiago, one of the saturated zones of Chile, is carried out through 11 fixed surface monitoring stations distributed in the Metropolitan Region, which make up the Automatic Monitoring Network of Air Quality and Meteorology (MACAM network). The measurements are superficial and therefore allow recording the concentrations of pollutants and their spatial variability in two dimensions (2D); however, pollutants move and interact throughout the mix layer as atmospheric conditions allow, including synoptic scenarios that induce the transfer, accumulation and formation of pollutants at regional scales, which is crucial to preventing, control and model air pollution in three dimensions. In order to respond to the need for information that exists regarding the concentration of aerosols in height and the atmospheric stratification’s effect on its vertical distribution, the atmospheric stability conditions were analyzed through a vertical profile of meteorological variables (temperature, dew point, pressure and relative humidity) and concentration of particulate material segregated by size (n/L and μg/m3) study, using a portable laser aerosol spectrometer and sensors coupled to an unmanned aerial vehicle or Drone. Five measurement campaigns were carried out that allowed defining the ascending flight mode at constant speed as the most appropriate and reproducible and evidencing the effect of the stability zones on the MP concentration at height. It was verified that atmospheric stratification limits the vertical displacement of aerosols, affecting mainly and in greater magnitude the larger fractions (diameter between 1.00 μm and 10.0 μm), whose concentrations in number decrease considerably after an investment in most cases, this explains that the fraction most affected in mass (μg/m3) is the MP10, since it is the thickest particles that contribute the most in the mass of the sample. Consequently, the particles of the mentioned size decrease their contribution in the total number of particles per liter in height, this being the biggest difference when comparing the distribution of MP in height with the distribution of MP in surface. Finally, the aerosols were classified according to their size distribution of height and surface in two selected flights. For both flights, surface aerosols were classified as polydispersed and it was determined that the monodisperse or polydisperse classification of a sample of particles in height may be due both to the height difference of the measurement and to the intensity of the atmospheric stratification in both flights.
94

Flybot Secutity - Seguridad Aérea

Zúñiga, Christhal, Amigo, Juan 08 1900 (has links)
Tesis para optar al grado de Magíster en Gestión y Administración de Empresas / Christhal Zúñiga [Parte I Análisis estratégico y de mercado], Juan Amigo [Parte II Análisis organizativo - financiero] / Autores no envían autorización para el acceso a texto completo de su documento / Debido a la topografía de Chile existen numerosas actividades industriales y productivas que se desarrollan en zonas de difícil acceso en las cuales los drones pueden ser de gran ayuda. Para apoyar a estas empresas en labores de seguridad, vigilancia y monitoreo, se creó una propuesta de valor que consiste en generar eficiencia operacional mediante la utilización de tecnología avanzada de seguridad y monitoreo a través de drones, así como la prevención de incidentes para lograr eficiencia en los procesos de los clientes y el acceso a las imágenes captadas por los equipos vía web en tiempo real. Además se propone dar un aporte a la gestión realizando informes de incidentes y de monitoreo periódico. El mercado objetivo son las empresas de distribución y generación de energía, de telecomunicaciones, mineras, empresas que cuenten grandes estructuras (puentes, edificios, torres de alta tensión, generadores eólicos de gran tamaño, etc.) y empresas de seguridad que prestan servicios a las antes mencionadas. Existen dos factores claves para el éxito de la compañía, el primero consiste en la disponibilidad del servicio, 24 horas durante 365 días del año, y la oportunidad, que consiste en garantizar tiempos de respuesta acordes a las necesidades de los clientes. Las operaciones están enfocadas en asegurar el cumplimiento de estas dos premisas mediante una estructura funcional liviana, flexible y dinámica. Además, el diseño de los sistemas y procesos se hará bajo la lógica de redundancia (N+1), esto es, cada recurso crítico utilizado en los procesos críticos (N) contará con un recurso adicional como backup (+1). En términos prácticos, si se necesita de 1 equipo dron para cubrir un radio de 100 km, se dispondrá de otro equipo de similares características para cubrir la misma zona en caso de falla del primero. Según el análisis financiero realizado, el negocio es intensivo en uso de capital y encuentra el punto de equilibrio alrededor del tercer año cuando logra tener una cobertura a nivel nacional lo que favorece la rentabilidad de este negocio lucrativo en el mediano y largo plazo. Una vez que se haya cubierto la brecha de aprendizaje, esta solución puede ser escalable a otras industrias así como a nivel sudamericano debido a que existen otros países con configuración geográfica similar a la Chilena.
95

Towards battery health management for lithium polymer battery-powered small-size rotary-wing unmanned aerial vehicles

Sierra Páez, Gina Katherine January 2018 (has links)
Doctora en Ingeniería Eléctrica / Little work has been done on Battery Health Management (BHM) for rotary-wing Unmanned Aerial Vehicles (UAVs) despite the fact that they have become increasingly popular. They are highly maneuverable and enable both safe and low-cost experimentation in mapping, navigation, and testing of control algorithms in three dimensions. Also, they can perform maneuvers that cannot be achieved by their fixed-wing counterparts (e.g., hover in place, and take off and land vertically (VTOL)). However, small-size aircraft typically have weight, size and cost constraints. Thus, as small-size UAVs become more prevalent, the need for computationally efficient software will increase. This thesis proposes a holistic framework for the design, implementation and experimental validation of Battery Health Management (BHM) systems in small-size rotatory-wing Unmanned Aerial Vehicles (UAVs) that allows to accurately (i) estimate the State of Charge (SOC), and (ii) predict the End of Discharge (EOD) time of lithium-polymer batteries in small-size multirotors by using a model-based prognosis architecture that is efficient and feasible to implement in low-cost hardware. The proposed framework includes a simplified battery model that incorporate the electric load dependence, temperature dependence and SOC dependence by using the concept of Artificial Evolution to estimate some of its parameters, along with a novel Outer Feedback Correction Loop (OFCL) during the estimation stage which adjusts the variance of the process noise to diminish bias in Bayesian state estimation and helps to compensate problems associated with incorrect initial conditions in a non-observable dynamic system. Also, it provides an aerodynamic-based characterization of future power consumption profiles and utilizes a new definition of probability of failure to mitigate the risk. A quadrotor has been used as the validation platform. This thesis is the first research effort towards BHM for small-size rotary-wing UAVs validated beyond numerical simulations, and that addresses the problem from an efficient approach for constrained computing platforms. A proper prognosis of the EOD time is not only necessary to verify if the mission goal(s) can be accomplished but also essential to aid in online decision-making activities such as fault mitigation and mission replanning. Therefore, the results of this work will allow making decisions about the flight and having enough confidence in those decisions so that the mission objectives can be optimally achieved. Given that: (i) the flight times in battery-powered UAVs are indeed short, (ii) most flight plans are highly conservatives due to they suffer from uncertainties in estimating the remaining charge, (iii) applications in urban zones are limited due to the risk associated with accidental battery run-down during the flight, and (iv) UAVs are ideally suited for long endurance applications; it hopes the results of this research become a significant contribution to the battery-powered rotary-wing UAVs field. / Este trabajo ha sido parcialmente financiado por CONICYT bajo la beca CONICYT-PCHA/Doctorado Nacional /2014-63140178
96

Bezpilotní války: Jak liberální demokracie legitimizuje útoky a zabíjení pomocí dronů v zahraničí / Unmanned Warfare: How Liberal Democracy Legitimizes Drone Attacks and Killings Abroad

Kocourek, Tomáš January 2017 (has links)
Diploma thesis " and Killings Abroad" is dedicated to depiction of employment of armed unmanned aerial administration's officials. The thesis is based on constructivist conception of world affairs isn't employed in order to describe objective realit Obama administration's of "us" and "them", that has proved to be very flexible in this study, underpins legitimization of
97

The implementation of development technologies and the future of drones : The way forward with sustainable technological solutions through a focus on drones and the SDGs

Cotte, Jonathan January 2021 (has links)
The chase for technological advancements is a train which the whole world wants to catch in order to streamline and expand on the current systems found within each respective society. New technological solutions are constantly being invented and re-invented for the purpose of accommodating to new development strategies. But much of the systems being introduced in the development sector are not well known by the general public, and examples of practical solutions and the importance of local adaptation are often left behind promises of prosperity and revenue. To understand how to implement localized technological solutions is through this paper realized to be one of the first steppingstones that will lay the foundation for development. Drones have become a worldwide sensation, known for its versatile and adaptable nature and now being introduced in even more areas never thought of before. By being involved with healthcare, security, agriculture, transport, military, observation and humanitarian assistance have made drones a lucrative solution that many seek to incorporate.  This thesis explores some of the applications listed above through a structured focus comparison of case studies in order to expand the knowledge about drones as a sustainable development solution, while also exploring the importance and challenges in the implementation of similar solutions. By using the Technology Justice framework, we will be able to understand how the solutions can be sustainable and acquire longevity in development projects when used as a solution to reach development. We can see the importance of the local context and how the lack of it can cause the projects to collapse even before they begin. Let us embark on a journey taking us through the present day of technological solutions and the implementation of them to understand how to make them right.
98

Investigating the Threats of Unmanned Aircraft Systems (UAS) at Airports

Cheng Wang (9745922) 15 December 2020 (has links)
Safety is the top priority for the aviation industry and a safe airport environment is essential to aviation safety. However, due to the increasing prevalence of UAS in recent years, UAS sightings have become a potential threat to airports. When UAS appear in the vicinity of airports, they bring safety concerns and result in negative operational and economic impacts on airports. Since the FAA’s mission is to provide the safest and most efficient aerospace system in the world, further research regarding the threat of UAS sightings to airports is needed. The purpose of this study is to investigate the threat of UAS to airports and in the national airspace system (NAS). This study includes three primary components: the analysis of 6,551 Federal Aviation Administration (FAA) UAS sighting reports, a case study of the impacts of the UAS sighting at Newark Liberty International Airport (EWR) on January 22, 2019, and a synthesis of airport operator perspectives based on interviews with airport personnel at five airports. The analysis of UAS sighting reports shows the characteristics of UAS sightings, the case study on EWR UAS illustrates the impact of the UAS sighting at the airport, and interview results illustrate the current perspective of airport operators regarding the risk of UAS. Along with the results, the scientific methods of identifying and analyzing the characteristics of UAS sightings in controlled airspace close to airports could be used by researchers to study UAS sightings in the future. Findings from this study may be beneficial to multiple stakeholders, including airport personnel, regulators, entrepreneurs, and vendors in the aviation industry. <br>
99

An Examination of the Percussion Writing in the Chamber Works of George Crumb, 1960-1980 with Three Recitals of Selected Works of Bergsma, Kurka, Miyoshi, Niimi, Takemitsu, and Others

LedBetter, Robert B. 08 1900 (has links)
In this study, the unique style of percussion writing in the chamber works of George Crumb, written between 1960 and 1980, is examined. The principal aspects examined within this study include: the extended instrumental techniques, the use of percussion within the musical imagery, soloistic treatment, compositional and notational procedures, and specific performance problems pertaining to the chamber work Songs, Drones, and Refrains of Death.
100

THE CONTEMPORARY CHALLENGES OF DRONE WARFARE : A descriptive and critical analysis on the contemporary challenge of integrating just war theory with artificial intelligence in warfare.

Hägg, Joel January 2021 (has links)
Due to the rapid technological advancements of the 21st century the fundamental nature of warfare has changed. Drones along with autonomous weapon systems has presented new challenges to the traditional concept and internal interpretations of just war theory. The purpose of this thesis is to present an analytical summary of the academic debate surrounding the emergence of AI technology, and how it has challenged the core principles embodied within jus in bello and jus ad bellum. Furthermore, the thesis explores the ethical issues external to just war theory principles, with a focus on how AI technology has established unique challenges for drone operators as a consequence of this contemporary phenomenon of war. This is done through a descriptive idea analysis and a critical analysis based on existing empirical material on the current academic debate on this issue.  While the advantages of drones and LAWS are evidently presented throughout this thesis, the repercussions are equally as important to contemplate. Thus, the findings in this thesis concludes that it is difficult to argue in favour or against the emergence of AI technology in war, as relevant arguments exist on both sides of the spectrum. However, the challenges for future just war theorists will be to adjust and reinterpret the moral foundations embodied within the principles of jus in bello and jus ad bellum to adhere to this contemporary phenomenon of war.

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