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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.
171

Možnosti rozvoje a zajištění bezpečnosti dálkově řízených letadel (RPAS) v ČR / Development opportunities and ensure the safety of remote-controlled aircraft (RPAS) in Czech Republic

Habrnal, Lukáš January 2015 (has links)
Tato diplomová práce se zabývá možnostmi rozvoje a zajištěním bezpečnosti dálkově řízených letadel (RPAS) v ČR. Práce je rozdělena do 3 hlavních částí: legislativní, technické a bezpečnostní. V legislativní části najdeme současné a připravované předpisy pro RPAS. Technická část popisuje vývoj bezpilotního letectví až k dnešním civilním RPAS, které jsou popsány na příkladech používaných v ČR. V poslední části je věnován prostor oblastem, které, především z bezpečnostního hlediska, omezují rozvoj RPAS.
172

Inspektionsmetoder för inre vattenvägar i vattenkraftverk / Inspection methods for internal waterways in hydropower plants

Sundberg, Sebastian, Amsköld, Tobias January 2015 (has links)
Den svenska vattenkraften står för nästan 50 % av landets elproduktion vilket gör dess konstruktioner till en viktig del av samhällets infrastruktur. För att ett vattenkraftverk ska fungera effektivt och säkert ställs höga krav på komponenternas funktion och kondition. I dagsläget genomförs därför rutinmässiga kontroller på, i och runt dessa anläggningar. För de aggregatnära inre vattenvägarna genomförs detta ca vart åttonde år i samband med reparationer av turbinerna, vilka då måste tömmas på vatten. För till- och utloppstunnlarna, som ofta är drivna i berg, finns det dock inte några sådana rutiner. Detta i kombination med att majoriteten av Sveriges vattenkraftverk har uppnått en ålder på över 50 år gör att branschen har börjat bli intresserade av att få kännedom om skicket på tunnlarna. Att genom-föra inspektioner genom att torrlägga dessa är dock en tidsödande process som kräver att kraftverket är avstängt under en lång tid och därmed ger en stor ekonomisk förlust för ägaren. Detta arbete har därför utförts med syfte att utvärdera till vilken grad inspektioner med undervattensfarkoster, ROV, kan användas som alternativ till inspektioner av inre vatten-vägar, både aggregatnära och i till- och utloppstunnlarna. En litteraturstudie har genomförts, om vattenkraftverk, vanliga skador, dagens inspektionsmetoder samt hur en ROV är uppbyggd och fungerar. Arbetet innefattar även tre praktiska moment bestående av deltagande på en inspektion av torrlagda aggregatnära inre vattenvägar och en inspektion med ROV i en 2,5 km lång utloppstunnel samt egna försök med inhyrd ROV för att undersöka vilka typer av betongskador som är möjliga att detektera. Resultatet från samtliga delar i arbetet pekar på att besiktningar med ROV kan övervägas för flera olika typer av inspektioner. För till- och utloppstunnlar är denna typ av inspektion många gånger den enda rimliga. För de aggregatnära inre vattenvägarna ger dagens inspektionsmetoder med torrläggning ett fullgott resultat, men ROV skulle kunna vara ett alternativ vid svårtillgängliga delar, t.ex. på grund av utformning eller stora läckage. / Swedish hydro power accounts for nearly 50 % of the country's electricity production which makes the constructions within this production system an important part of the societal infrastructure. To ensure safe and efficient operation of these hydroelectric power plants high demands are put on the components function and condition. Therefore, routine inspections are carried out inside and around these facilities. For the waterways directly connected to the power station, such as penstocks, wicket gates and draft tubes, these checkups are made about every eight years simultaneously as planned repairs of the turbine, when the waterways have to be emptied. For the head and trail race tunnels, which often are driven in bedrock, there are no such routines. This, in combination with the fact that the majority of the Swedish hydroelectric plants have attained the age of over 50 years, has led to an increased interest within the industry in ways to increase their knowledge about the condition of these water passageways. To conduct inspections by draining the tunnels is however a very time consuming process that requires the power plant to be turned off for a long time causing a major financial loss for the owner. The purpose of this master thesis is to assess the extent to which inspections with remotely operated vehicles, ROV, can be used as an alternative method for inspections of covered waterways, both those close to the power house and the head and tail race tunnels. A literature study of hydro power plants, common damages, current inspection methods and the construction and function of an ROV, has been conducted. The method also includes three practical activities, participation at inspections in drained waterways and at an ROV inspection of a 2.5 km tail race tunnel. Furthermore, tests with a rented ROV were carried out to investigate what type of concrete damages that are possible to detect using this method. The result from all parts in this thesis indicates that examinations by ROV can be considered for several types of inspections. For head and tail race tunnels, this type of inspection is often the only reasonable method. For the waterways directly connected to the power station, current inspection methods by draining show good result. But the ROV could here be an alternative in inaccessible areas, for instance due to waterway design or heavy leakage for instance.
173

Unmanned ground vehicles: adaptive control system for real-time rollover prevention

Mlati, Malavi Clifford 04 1900 (has links)
Real-Time Rollover prevention of Unmanned Ground Vehicle (UGV) is very paramount to its reliability and survivability mostly when operating on unknown and rough terrains like mines or other planets.Therefore this research presents the method of real-time rollover prevention of UGVs making use of Adaptive control techniques based on Recursive least Squares (RLS) estimation of unknown parameters, in order to enable the UGVs to adapt to unknown hush terrains thereby increasing their reliability and survivability. The adaptation is achieved by using indirect adaptive control technique where the controller parameters are computed in real time based on the online estimation of the plant’s (UGV) parameters (Rollover index and Roll Angle) and desired UGV’s performance in order to appropriately adjust the UGV speed and suspension actuators to counter-act the vehicle rollover. A great challenge of indirect adaptive control system is online parameter identification, where in this case the RLS based estimator is used to estimate the vehicles rollover index and Roll Angle from lateral acceleration measurements and height of the centre of gravity of the UGV. RLS is suitable for online parameter identification due to its nature of updating parameter estimate at each sample time. The performance of the adaptive control algorithms and techniques is evaluated using Matlab Simulink® system model with the UGV Model built using SimMechanics physical modelling platform and the whole system runs within Simulink environment to emulate real world application. The simulation results of the proposed adaptive control algorithm based on RLS estimation, show that the adaptive control algorithm does prevent or minimize the likely hood of vehicle rollover in real time. / Electrical and Mining Engineering / M. Tech. (Electrical Engineering)
174

Aircraft Based GPS Augmentation Using an On-Board RADAR Altimeter for Precision Approach and Landing of Unmanned Aircraft Systems

Videmsek, Andrew R. 02 June 2020 (has links)
No description available.
175

Sediment Dispersal Processes and Anthropogenic Impacts at Rex Lake, Summit County, Ohio

Mitchell, Stephanie Bianca 17 September 2015 (has links)
No description available.
176

The role of the ocean in convective burst initiation: implications for tropical cyclone intensification

Hennon, Paula Ann 05 January 2006 (has links)
No description available.
177

Influence of seasonally variable hypoxia on epibenthic communities in a coastal ecosystem, British Columbia, Canada

Chu, Jackson Wing Four 25 April 2016 (has links)
Natural cycles of environmental variability and long-term deoxygenation in the ocean impose oxygen deficiency (hypoxia) on marine communities. My research exploits a naturally occurring hypoxia cycle in Saanich Inlet, British Columbia, Canada where I combined spatial surveys with remotely operated vehicles, ecological time-series from the subsea cabled observatory VENUS, and lab-based respirometry experiments to examine the influence of seasonally variable oxygen conditions on epibenthic communities. In situ oxygen thresholds established for dozens of fish and invertebrate species in this system show they naturally occur in lower oxygen levels than what general lethal and sublethal thresholds would predict. Expansion of hypoxic waters induced a loss of community structure which was previously characterized by disjunct distributions among species. Communities in variable hypoxia also have scale-dependent structure across a range of time scales but are primarily synchronized to a seasonal oscillation between two phases. Time-series revealed timing of diurnal movement in the slender sole Lyopsetta exilis and reproductive behavior of squat lobster Munida quadrispina in the hypoxia cycle. Hypoxia-induced mortality of sessile species slowed the rate of community recovery after deoxygenation. The 10-year oxygen time-series from VENUS, revealed a significant increase in the annual low-oxygen period in Saanich Inlet and that deoxygenation has occurred in this system since 2006. Differences in the critical oxygen thresholds (O2crit) and standard metabolic rates of key species (spot prawn Pandalus platyceros, slender sole, and squat lobster) determined the lowest in situ oxygen at which populations occurred and explained disproportionate shifts in distributions and community respiration. Finally, a meta-analysis on global O2crit reported for crustaceans showed that hypoxia tolerance differs among major ocean basins. Long-term trends of deoxygenation suggest a future regime shift may occur when the duration at which a system remains below critical oxygen levels exceeds the time needed for communities to recover. Species-specific traits will determine the critical threshold and the nature of the community response in systems influenced by variable states of oxygen deficiency. However, oceanographic and evolutionary history provides context when determining the regional response of benthic communities influenced by rapidly changing environments. / Graduate / 0329 / 0416 / 0433 / jwfchu@gmail.com
178

[en] ROBOTIC SYSTEM FOR MONITORING WATER QUALITY IN LENTIC ENVIRONMENTS / [pt] SISTEMA ROBÓTICO PARA MONITORAMENTO DA QUALIDADE DA ÁGUA EM AMBIENTES LÊNTICOS

MARCOS AURELIO PINTO MARZANO JR 18 February 2019 (has links)
[pt] Nas últimas décadas, a crescente conscientização ambiental levou ao reconhecimento da necessidade do uso responsável dos recursos hídricos. Para garantir isso, a boa gestão de reservatórios hídricos requer um monitoramento ambiental adequado, com medições confiáveis dos parâmetros de qualidade da água em vários pontos do reservatório, permitindo o controle da qualidade da água e seus impactos na fauna, flora e comunidades ribeirinhas dos reservatórios. O monitoramento das variáveis ambientais dos reservatórios é atualmente realizado por processo tradicional de coleta manual. Infelizmente, no Brasil, as iniciativas de produzir um sistema robótico aquático com tecnologia nacional e de baixo custo, quando comparado a equivalentes importados, são ainda raras e se restringem a algumas poucas instituições acadêmicas, não tendo sido localizado nenhum fabricante comercial deste tipo de veículo no país. Visando preencher esta lacuna, o presente trabalho teve como objetivo o desenvolvimento do protótipo de um sistema robótico aquático capaz de se locomover autonomamente em lagoas, lagos e reservatórios, coletando informações físico-químicas da água e armazenando estes dados na memória. Além disso, foi incluído no protótipo uma câmera de vídeo, sistema de iluminação e um sistema de controle remoto, objetivando o controle pela equipe em terra. Nos testes realizados em dias ensolarados e chuvosos, o robô apresentou boa dirigibilidade, estabilidade e manobrabilidade. O vaso de pressão do sistema robótico resistiu às pressões necessárias durante os testes, a eletrônica conseguiu atender as especificações de projeto e o software conseguiu estabelecer um controle de navegação, cumprindo o trajeto de uma rota estabelecida. / [en] In recent decades, the growing environmental awareness has led to the recognition of the need for responsible use of water resources. To ensure this, the good management of water reservoirs requires adequate environmental monitoring, with reliable measurements of water quality parameters in various parts of the reservoir, allowing the control of water quality and its impacts on fauna, flora and riverine communities of the reservoirs. Monitoring environmental variables of the reservoirs is currently performed by traditional process of manual collection. Unfortunately, in Brazil, initiatives to produce a water robotic system with national and low cost technology, compared to imported equivalents, are still rare and restricted to a few academic institutions, and no commercial manufacturer of this type of vehicle was found in the country. Aiming to fill this gap, the main objective of this study was to develop a prototype of a water robotic system capable of autonomously navigate in ponds, lakes and reservoirs, collecting physicochemical information of water and storing this data in memory. Moreover, a video camera, illumination and a remote control system were included in the prototype, allowing the team on the ground to control the prototype. In tests conducted in sunny and rainy days, the robot presented good handling, stability and maneuverability. The robotic system pressure vessel resisted pressures required during testing, the electronics met the design specifications and the software was able to establish a navigation control, fulfilling the path of an established route.
179

Design, testing and demonstration of a small unmanned aircraft system (SUAS) and payload for measuring wind speed and particulate matter in the atmospheric boundary layer

Riddell, Kevin Donald Alexander 13 May 2014 (has links)
The atmospheric boundary layer (ABL) is the layer of air directly influenced by the Earth’s surface and is the layer of the atmosphere most important to humans as this is the air we live in. Methods for measuring the properties of the ABL include three general approaches: satellite-based, ground- based and airborne. A major research challenge is that many contemporary methods provide a restricted spatial resolution or coverage of variations of ABL properties such as how wind speed varies across a landscape with complex topography. To enhance our capacity to measure the properties of the ABL, this thesis presents a new technique that involves a small unmanned aircraft system (sUAS) equipped with a customized payload for measuring wind speed and particulate matter. The research presented herein outlines two key phases in establishing the proof-of-concept of the payload and its integration on the sUAS: (1) design and testing and (2) field demonstration. The first project focuses on measuring wind speed, which has been measured with fixed wing sUASs in previous research, but not with a helicopter sUAS. The second project focuses on the measurement of particulate matter, which is a major air pollutant typically measured with ground- based sensors. Results from both proof-of-concept projects suggest that ABL research could benefit from the proposed techniques.
180

Legality of use of drones / Legalita užití dronů

Slabá, Tereza January 2015 (has links)
The thesis analyses the legality of the use of drones in warfare based on the examination of three specific case studies. Firstly the use of armed drones in Afghanistan 2001 and 2002, then Pakistan drone strikes ongoing since 2004 and lastly the Yemen case study. A developed legal framework is used to assess the legality of the use of drones. Furthermore, it briefly touches upon the aspects of morality and ethics of the use of the unmanned aerial vehicles in combat.

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