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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.
111

A Surveillance System to Create and Distribute Geo-Referenced Mosaics Using SUAV Video

Andersen, Evan D. 14 June 2008 (has links)
Small Unmanned Aerial Vehicles (SUAVs) are an attractive choice for many surveillance tasks. However, video from an SUAV can be difficult to use in its raw form. In addition, the limitations inherent in the SUAV platform inhibit the distribution of video to remote users. To solve the problems with using SUAV video, we propose a system to automatically create geo-referenced mosiacs of video frames. We also present three novel techniques we have developed to improve ortho-rectification and geo-location accuracy of the mosaics. The most successful of these techniques is able to reduce geo-location error by a factor of 15 with minimal computational overhead. The proposed system overcomes communications limitations by transmitting the mosaics to a central server where there they can easily be accessed by remote users via the Internet. Using flight test results, we show that the proposed mosaicking system achieves real-time performance and produces high-quality and accurately geo-referenced imagery.
112

Fluvial Processes in Motion: Measuring Bank Erosion and Suspended Sediment Flux using Advanced Geomatic Methods and Machine Learning

Hamshaw, Scott Douglas 01 January 2018 (has links)
Excessive erosion and fine sediment delivery to river corridors and receiving waters degrade aquatic habitat, add to nutrient loading, and impact infrastructure. Understanding the sources and movement of sediment within watersheds is critical for assessing ecosystem health and developing management plans to protect natural and human systems. As our changing climate continues to cause shifts in hydrological regimes (e.g., increased precipitation and streamflow in the northeast U.S.), the development of tools to better understand sediment dynamics takes on even greater importance. In this research, advanced geomatics and machine learning are applied to improve the (1) monitoring of streambank erosion, (2) understanding of event sediment dynamics, and (3) prediction of sediment loading using meteorological data as inputs. Streambank movement is an integral part of geomorphic changes along river corridors and also a significant source of fine sediment to receiving waters. Advances in unmanned aircraft systems (UAS) and photogrammetry provide opportunities for rapid and economical quantification of streambank erosion and deposition at variable scales. We assess the performance of UAS-based photogrammetry to capture streambank topography and quantify bank movement. UAS data were compared to terrestrial laser scanner (TLS) and GPS surveying from Vermont streambank sites that featured a variety of bank conditions and vegetation. Cross-sectional analysis of UAS and TLS data revealed that the UAS reliably captured the bank surface and was able to quantify the net change in bank area where movement occurred. Although it was necessary to consider overhanging bank profiles and vegetation, UAS-based photogrammetry showed significant promise for capturing bank topography and movement at fine resolutions in a flexible and efficient manner. This study also used a new machine-learning tool to improve the analysis of sediment dynamics using three years of high-resolution suspended sediment data collected in the Mad River watershed. A restricted Boltzmann machine (RBM), a type of artificial neural network (ANN), was used to classify individual storm events based on the visual hysteresis patterns present in the suspended sediment-discharge data. The work expanded the classification scheme typically used for hysteresis analysis. The results provided insights into the connectivity and sources of sediment within the Mad River watershed and its tributaries. A recurrent counterpropagation network (rCPN) was also developed to predict suspended sediment discharge at ungauged locations using only local meteorological data as inputs. The rCPN captured the nonlinear relationships between meteorological data and suspended sediment discharge, and outperformed the traditional sediment rating curve approach. The combination of machine-learning tools for analyzing storm-event dynamics and estimating loading at ungauged locations in a river network provides a robust method for estimating sediment production from catchments that informs watershed management.
113

Airborne Infrared Target Tracking with the Nintendo Wii Remote Sensor

Beckett, Andrew 1984- 14 March 2013 (has links)
Intelligence, surveillance, and reconnaissance unmanned aircraft systems (UAS) are the most common variety of UAS in use today and provide invaluable capabilities to both the military and civil services. Keeping the sensors centered on a point of interest for an extended period of time is a demanding task requiring the full attention and cooperation of the UAS pilot and sensor operator. There is great interest in developing technologies which allow an operator to designate a target and allow the aircraft to automatically maneuver and track the designated target without operator intervention. Presently, the barriers to entry for developing these technologies are high: expertise in aircraft dynamics and control as well as in real- time motion video analysis is required and the cost of the systems required to flight test these technologies is prohibitive. However, if the research intent is purely to develop a vehicle maneuvering controller then it is possible to obviate the video analysis problem entirely. This research presents a solution to the target tracking problem which reliably provides automatic target detection and tracking with low expense and computational overhead by making use of the infrared sensor from a Nintendo Wii Remote Controller.
114

Géométrie 3D des lits de rivière par stéréophotogrammétrie à travers l'eau

Feurer, Denis 20 November 2008 (has links) (PDF)
Les considérations environnementales occupent une place croissante dans l'opinion publique ainsi que dans les politiques nationales et internationales. Le cas de la rivière en est un exemple particulièrement frappant : au centre d'enjeux multiples et pour certains hautement stratégiques (énergie, irrigation), elle est le théâtre d'un conflit d'usages donnant lieu à l'établissement de compromis particulièrement fins pour la gestion de la ressource. Dans les approches les plus courantes, la description de l'état et du fonctionnement d'un hydrosystème tel que celui de la rivière est effectuée par la mesure de variables physiques ou la mise en relation des variables d'intérêt avec les paramètres physiques quantifiables caractérisant le milieu (modèles hydrauliques, modèles hydrobiologiques). L'objectif de ce travail est donc de proposer une réponse à la question de la mesure de la géométrie de la rivière par télédétection. On s'attache tout d'abord à décrire le contexte particulier de la rivière mentionné plus haut puis à effectuer un état de l'art faisant ressortir une lacune pour la restitution du relief immergé par stéréo à travers l'eau avec des moyens légers. On propose ensuite une méthode complète d'acquisition d'images et de traitements permettant d'estimer le relief immergé de rivière. Le travail effectué repose sur la mise en oeuvre de moyens technologiques légers permettant une grande flexibilité pour l'acquisition des données. On se base sur les méthodes de stéréorestitution du relief, pour lesquelles on propose une adaptation au contexte spécifique de la photogrammétrie à travers l'eau. Enfin, on met en place des méthodes de correction des mesures brutes intégrant des contraintes a priori (cohérence hydraulique ; cohérence spatiale) pour la correction de l'effet de réfraction. L'application de la méthode développée en conditions opérationnelles sur une rivière peu profonde à fond de galets montre que la mesure du relief immergé par stéréophotogrammétrie est possible, et permet une représentation de la topographie du lit d'une qualité compatible avec les modèles hydrobiologiques (modèles habitat-poisson). On a ainsi développé, testé, validé et determiné les conditions d'application d'une méthode de mesure de la géométrie de la rivière par télédétection originale et complémentaire des technologies existantes.
115

Development of Tools to Assess the Effects of Lunasin on Normal Development and Tumor Progression in Drosophila Melanogaster

Jones, Gillian E. 01 August 2013 (has links)
Soy contains many bioactive molecules known to elicit anti-cancer effects. One such peptide, Lunasin, has been shown to selectively act on newly transformed cells while having no cytotoxic effect on non-tumorigenic or established cancer cell lines. In this study we attempt to understand the developmental effects of Lunasin overexpression in vivo and create reagents that will help us understand Lunasin’s anti tumorigenic effects in an intact organism. cDNA encoding lunasin and EGFP-lunasin were cloned into pUAST and microinjected into Drosophila embryos. Tissue-specific overexpression of EGFP-Lun in the resulting transgenic lines was accomplished by crossing transgenics to various GAL4 driver lines. Progeny were assessed for phenotypic alterations and no phenotypic abnormalities were observed in tissues expressing EGFP-Lunasin, supporting current studies that show Lunasin does not affect normal cells. Previous studies have localized Lunasin to the nuclear compartment. To test if this was the case for EGFP-Lun, subcellular localization of EGFP-Lun was determined via fluorescence microscopy. Salivary glands from EGFP-Lun expressing individuals were dissected, fixed, and mounted in Vectashield® with the nuclear stain, DAPI. Our results demonstrate that EGFP-Lun, like native Lunasin, is localized to the nucleus. Eight transgenic lines were mapped to specific chromosomes and EGFP-Lun transgenic line GEJ1-L2 was balanced in preparation for use in tumor suppression studies. In summary, we have created and characterized transgenic flies capable of overexpressing Lunasin under the control of the GAL4/UAS system. Localization of EGFP-Lunasin to the nucleus and data on the phenotypic consequence of its overexpression in flies is presented. Finally, reagents created as part of this thesis will aid experiments aimed at understanding the effects of Lunasin on benign and invasive tumors.
116

Short range reconnaissance unmanned aerial vehicle / S.J. Kersop.

Kersop, Stefanus Jacobus January 2009 (has links)
Unmanned aerial vehicles (UAVs) have been used increasingly over the past few years. Special Forces of various countries utilise these systems successfully in war zones such as Afghanistan. The biggest advantage is rapid information gathering without endangering human lives. The South African National Defence Force (SANDF) also identified the need for local short range aerial reconnaissance and information gathering. A detailed literature survey identified various international players involved in the development of small hand-launch UAV systems. Unfortunately, these overseas systems are too expensive for the SANDF. A new system had to be developed locally to comply with the unique requirements, and budget, of the SANDF. The survey of existing systems provided valuable input to the detailed user requirement statement (URS) for the new South African development. The next step was to build a prototype using off-the-shelf components. Although this aircraft flew and produced good video images, it turned out to be unreliable. The prototype UAV was then replaced with a standard type model aircraft, purchased from Micropilot. Some modifications were needed to ensure better compliance with the URS. Laboratory and field tests proved that the aircraft can be applied for aerial images, within range of 10 km from the ground control station (GCS). The major limitation is that it can only fly for 40 minutes. Furthermore, the airframe is not robust, needing repairs after only 15 flights. Although the system has shortcomings, it has already been used successfully. It is expected that improved battery technologies and sturdier light-weight materials will further help to improve the system beyond user specifications. / Thesis (MIng (Electrical Engineering))--North-West University, Potchefstroom Campus, 2010.
117

Short range reconnaissance unmanned aerial vehicle / S.J. Kersop.

Kersop, Stefanus Jacobus January 2009 (has links)
Unmanned aerial vehicles (UAVs) have been used increasingly over the past few years. Special Forces of various countries utilise these systems successfully in war zones such as Afghanistan. The biggest advantage is rapid information gathering without endangering human lives. The South African National Defence Force (SANDF) also identified the need for local short range aerial reconnaissance and information gathering. A detailed literature survey identified various international players involved in the development of small hand-launch UAV systems. Unfortunately, these overseas systems are too expensive for the SANDF. A new system had to be developed locally to comply with the unique requirements, and budget, of the SANDF. The survey of existing systems provided valuable input to the detailed user requirement statement (URS) for the new South African development. The next step was to build a prototype using off-the-shelf components. Although this aircraft flew and produced good video images, it turned out to be unreliable. The prototype UAV was then replaced with a standard type model aircraft, purchased from Micropilot. Some modifications were needed to ensure better compliance with the URS. Laboratory and field tests proved that the aircraft can be applied for aerial images, within range of 10 km from the ground control station (GCS). The major limitation is that it can only fly for 40 minutes. Furthermore, the airframe is not robust, needing repairs after only 15 flights. Although the system has shortcomings, it has already been used successfully. It is expected that improved battery technologies and sturdier light-weight materials will further help to improve the system beyond user specifications. / Thesis (MIng (Electrical Engineering))--North-West University, Potchefstroom Campus, 2010.
118

Jämförelse av metod vid stabilitetsanalys i bergslänter / Comparison of Methods for Slope Stability Analysis

Ekberg Bergman, Emelie January 2018 (has links)
En bergslänts stabilitet styrs av berggrundens egenskaper, så som sprickegenskaper och bergkvalité. För att uppnå önskad stabilitet i en bergslänt behöver de bergmekaniska parametrarna kartläggas och analyseras för att fastställa risker och stabilitetsåtgärder. Syftet med studien är att utvärdera kvalitén på bergteknisk data från digitalfotogrammetriska 3D-modeller genom att jämföra resultatet med manuella mätningar från konventionell kartläggning. Målet är även att utforska potentialen för användning av fotogrammetrisk 3D-modellering vid stabilitetsanalyser i bergslänter genom att utvärdera den bergtekniska analys som kan göras utifrån fotogrammetrisk data. Sprickmätningar framtagna från 3D-modellen visade sig ha samma kvalité som manuella mätningar tagna enligt konventionell metod. Den UAS-baserade fotogrammetrin kan dock inte ersätta den konventionella analysen helt vid stabilitetsanalyser men kan användas som ett kompletterande verktyg i bergtekniska undersökningar. Fotogrammetrin möjliggör datainsamling från ett säkrare avstånd vilket minskar riskmomenten som den konventionella metoden medför vid arbete i fält. Den digitala metoden visade sig även ha fler fördelar såsom möjligheten av kartläggning och analysering framför datorn för mindre tids- och kostnadskrävande moment, digital datalagring samt att slänter med begränsad åtkomst kan karteras. / The stability of a rock slope is controlled by the rock’s mechanical properties, such as rock quality and facets. To achieve the desired stability in a rock slope, the mechanical parameters need to be mapped and analysed to determine possible failures and decide necessary stability measures. The purpose of this study is to evaluate the quality of rock technical data from digital photogrammetry 3D models by comparing the result with manual measurements from conventional mapping. The goal is also to explore the potential uses of photogrammetric 3D models for rock slope stability analyses by evaluate the photogrammetric data. Facets extracted from 3D models were found to have the same quality as manual measurements. However, the UAS-based method cannot completely replace the conventional method but can be useful as a complementary tool. Photogrammetry enables the collection of data from a safer distance, which reduces workplace hazards that the conventional method entails. The digital method also proved to have more advantages, such as the possibility of digital mapping and analysing which is less costly and time-consuming, digital data storage and the possibility to access outcrops that can’t be mapped with manually measurements due to inaccessibility.
119

Modelo de arquitetura em camadas para interconexão de sistemas em SANT / Layered architecture model for interconnection of systems in UAS

Emerson Alberto Marconato 11 November 2016 (has links)
Modelos de arquitetura têm sido utilizados para permitir o desenvolvimento mais adequado e estruturado de sistemas, desde os mais simples até os mais complexos. A utilização desses modelos em sistemas embarcados, principalmente quando se trata de sistemas embarcados críticos, como é o caso de veículos aéreos não tripulados (VANT), visam a permitir conformidades de padrões, redução no tempo de produção, redução e facilidade no processo de manutenção e desenvolvimento. Sistemas embarcados críticos possuem requisitos específicos, tais como alta confiabilidade e resposta em tempo real, segurança e desempenho. A definição de um modelo arquitetural que permita que esses quesitos sejam levados em consideração, propicie o atendimento aos padrões, além de permitir o desenvolvimento correto e acelerado é inovador, permitindo que não só a comunidade científica venha a ter benefícios com a sua concepção, mas também a indústria brasileira possa ganhar. Nesse sentido, este trabalho desenvolveu um modelo de arquitetura para a interconexão de sistemas aéreos não tripulados (SANTs) em Unified Modeling Language (UML)/System Modelling Language (SysML) denominado LARISSA (Layered ARchitecture model for Interconnection of SystemS in uAs). Como resultado deste trabalho foi possível a modelagem e especificação completa de um SANT fazendo uso desse modelo e a realização de diversos experimentos que permitiram validar o LARISSA. Os experimentos, focados na parte de comunicação, permitiram a concepção de um simulador de redes de VANTs. Os resultados obtidos demonstraram a eficiência e a eficácia do modelo de arquitetura LARISSA, além da sua flexibilidade em permitir que diferentes experimentos possam ser realizados, o que auxilia na obtenção de dados que facilitam o processo de certificação desses VANTs. / Architecture models have been used to allow more adequate and structured development of systems, from the simplest to the most complex. The use of models in embedded systems are used to enable compliance standards, reduction in production time and ease of maintenance and development, especially when it comes to critical embedded systems such as unmanned aerial vehicles. Critical embedded systems have specific requirements, such as high reliability and real-time response, security and performance. The definition of an architectural model that deals with these requirements and standards and provides the service to standards allowing the correct and fast development is innovative and will provide benefits to the scientific and industrial communities. In this sense, this work developed an architectural model for the interconnection of Unmanned Aerial Systems (UAS) in Unified Modeling Language (UML)/System Modelling Language (SysML) called LARISSA (Layered ARchitecture model for Interconnection of SystemS in uAs). As a result of this development it was possible the modelling and specification of a complete UAS and the conduction of several experiments that allowed LARISSA validation. The experiments focused on the communication enabled the design of a UAV networks simulator. The results showed the efficiency and effectiveness of LARISSA architecture model, as well as its flexibility in carrying out different experiments, which helps in getting data to facilitate the certification process of these UAVs.
120

Automatic Dependent Surveillance-Broadcast for Detect and Avoid on Small Unmanned Aircraft

Duffield, Matthew Owen 01 May 2016 (has links)
Small unmanned aircraft systems (UAS) are rapidly gaining popularity. As the excitement surrounding small UAS has grown, the Federal Aviation Administration (FAA) has repeatedly stated that UAS must be capable of detecting and avoiding manned and unmanned aircraft. In developing detect-and-avoid (DAA) technology, one of the key challenges is identifying a suitable sensor. Automatic Dependent Surveillance-Broadcast (ADS-B) has gained much attention in both the research and consumer sectors as a promising solution. While ADS-B has many positive characteristics, further analysis is necessary to determine if it is suitable as a DAA sensor in environments with high-density small UAS operations. To further the understanding of ADS-B, we present a characterization of ADS-B measurement error that is derived from FAA regulations. Additionally, we analyze ADS-B by examining its strengths and weaknesses from the perspective of DAA on small UAS. To demonstrate the need and method for estimation of ADS-B measurements, we compare four dynamic filters for accuracy and computational speed. The result of the comparison is a recommendation for the best filter for ADS-B estimation. We then demonstrate this filter by estimating ADS-B measurements that have been recorded from the National Airspace System (NAS). We also present a novel long-range, convex optimization-based path planner for ADS-B-equipped small UAS in the presence of intruder aircraft. This optimizer is tested using a twelve-state simulation of the ownship and intruders.We also consider the effectiveness of ADS-B in high-density airspace. To do this we present a novel derivation of the probability of interference for ADS-B based on the number of transmitting aircraft. We then use this probability to document the need for limited transmit range for ADS-B on small UAS. We further leverage the probability of interference for ADS-B, by creating a tool that can be used to analyze self-separation threshold (SST) and well clear (WC) definitions based on ADS-B bandwidth limitations. This tool is then demonstrated by evaluating current SST and WC definitions and making regulations recommendations based on the analysis. Coupling this tool with minimum detection range equations, we make a recommendation for well clear for small UAS in ADS-B congested airspace. Overall these contributions expand the understanding of ADS-B as a DAA sensor, provide viable solutions for known and previously unknown ADS-B challenges, and advance the state of the art for small UAS.

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