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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

Detekce překážek / The obstacle detection

Hradiský, Marek January 2016 (has links)
Diploma thesis deals with design and the processing of video captured by Raspberry PI and the possibility of object detection in video. In this thesis is described Raspberry PI as well as video capturing by PiCamera module. There is also section about video processing by OpenCV.
92

Metody současné sebelokalizace a mapování pro hloubkové kamery / Methods for Simultaneous Self-localization and Mapping for Depht Cameras

Ligocki, Adam January 2017 (has links)
Tato diplomová práce se zabývá tvorbou fúze pozičních dat z existující realtimové im- plementace vizuálního SLAMu a kolové odometrie. Výsledkem spojení dat je potlačení nežádoucích chyb u každé ze zmíněných metod měření, díky čemuž je možné vytvořit přesnější 3D model zkoumaného prostředí. Práce nejprve uvádí teorií potřebnou pro zvládnutí problematiky 3D SLAMu. Dále popisuje vlastnosti použitého open source SLAM projektu a jeho jednotlivé softwarové úpravy. Následně popisuje principy spo- jení pozičních informací získaných vizuálními a odometrickými snímači, dále uvádí popis diferenciálního podvozku, který byl použit pro tvorbu kolové odometrie. Na závěr práce shrnuje výsledky dosažené datovou fúzí a srovnává je s původní přesností vizuálního SLAMu.
93

A Compton Camera for In-vivo Dosimetry in Ion-beam Radiotherapy

Kormoll, Thomas 22 February 2013 (has links)
In dieser Arbeit wird die Bildgebung durch eine Compton-Kamera zur Überwachung der Partikelstrahlentherapie erstmals an der Technischen Universität Dresden untersucht. Die inhärenten Beschränkungen der Methode wurden durch Berechnungen und Monte Carlo Simulationen studiert. Im Zuge dieser Untersuchungen erschien der Raumtemperatur-Halbleiter Cadmium Zink Tellurid als ein vielversprechendes Detektor-Material. Zur weiteren Untersuchung wurde eine einfache Compton-Kamera konstruiert bestehend aus einem Cadmium Zink Tellurid Detektor und einem ortsempfndlichen Szintillationsdetektor. Das System hat gezeigt, dass eine akkurate Bildgebung mit radioaktiven Punktquellen unter Laborbedingungen möglich ist. Weitere praktische Beschränkungen der Compton-Bildgebung unter Strahlbedingungen konnten durch Experimente an einem Protonen-Strahl hergeleitet werden. Durch die experimentellen Erfahrungen mit der in dieser Arbeit entwickelten Compton-Kamera konnten wertvolle Informationen gesammelt werden, die erlauben, die Bildrekonstruktion zu evaluieren und dazu beitragen, die weitere Forschung hin zu einer klinisch anwendbaren Compton-Kamera zu leiten.:Abstract/Zusammenfassung Illustration Index Index of Tables List of Abbreviations 0 Introduction 0.1 Motivation 0.2 Task 1 Physical Background 1.1 Interaction of Ionizing Radiation with Matter 1.1.1 Coherent Photon Scattering 1.1.2 Incoherent Photon Scattering 1.1.3 Complete Absorption in the Nuclear Electric Field 1.1.4 Pair Production 1.1.5 Total Photon Cross Section 1.1.6 Directly Ionizing Radiation 1.2 Prompt Gamma-rays from Nuclear Reactions 1.3 Detector Technology 1.3.1 Semiconductor Detectors 1.3.2 Scintillation Detectors 1.4 Compton Imaging 1.4.1 Image Formation 1.4.2 History and Application of Compton Cameras 1.5 Prompt Gamma-ray Imaging for In-vivo Dosimetry – Work of Other Groups 2 Design Study 2.1 Introduction 2.1.1 Emission Spectra – Available Data 2.2 Materials and Methods 2.2.1 Angular Resolution 2.2.2 Efficiency 2. Results 2.4 Conclusions 3 Prototype System 3.1 Overview 3.2 System Components 3.2.1 CdZnTe Detector and its Front-end-electronics 3.2.2 LSO Block-Detector 3.2.3 Mounting Frame 3.2.4 DAQ Hardware and Software 3.3 Results 3.3.1 Detector Performance 3.3.2 System Performance 3.4 Conclusions 4 Beam Experiments 4.1 Introduction 4.2 Materials and Methods 4.3 Results 4.3.1 Source Test 4.3.2 Beam Profile 4.3.3 Trigger Rate 4.3.4 Pixel Selection in the LSO 4.3.5 Phantom Measurement 4.4 Conclusions 5 Discussion Appendix A A.1 Technical Drawing of the CdZnTe Electrode Layout Bibliography Danksagung Erklärung / This work presents the first efforts at the Dresden University of Technology to study the feasibility of Compton imaging as a modality to monitor ion beam radiation therapy. The inherent limitations of the method have been studied by means of calculation and Monte Carlo simulation. As a result, the room-temperature semiconductor cadmium zinc telluride appeared as a promising detector material for a clinical device. For more detailed investigation, a simple Compton camera has been constructed comprising a cadmium zinc telluride detector and a position sensitive scintillation detector. This system has proven that accurate imaging of radioactive point sources in the laboratory is feasible. More practical restrictions of Compton imaging in beam conditions have been derived through experiments at a proton facility. Through the experimental work with the Compton camera developed in this work, valuable information was gathered which allowed to test the image reconstruction and to direct the further research towards a clinical Compton camera system.:Abstract/Zusammenfassung Illustration Index Index of Tables List of Abbreviations 0 Introduction 0.1 Motivation 0.2 Task 1 Physical Background 1.1 Interaction of Ionizing Radiation with Matter 1.1.1 Coherent Photon Scattering 1.1.2 Incoherent Photon Scattering 1.1.3 Complete Absorption in the Nuclear Electric Field 1.1.4 Pair Production 1.1.5 Total Photon Cross Section 1.1.6 Directly Ionizing Radiation 1.2 Prompt Gamma-rays from Nuclear Reactions 1.3 Detector Technology 1.3.1 Semiconductor Detectors 1.3.2 Scintillation Detectors 1.4 Compton Imaging 1.4.1 Image Formation 1.4.2 History and Application of Compton Cameras 1.5 Prompt Gamma-ray Imaging for In-vivo Dosimetry – Work of Other Groups 2 Design Study 2.1 Introduction 2.1.1 Emission Spectra – Available Data 2.2 Materials and Methods 2.2.1 Angular Resolution 2.2.2 Efficiency 2. Results 2.4 Conclusions 3 Prototype System 3.1 Overview 3.2 System Components 3.2.1 CdZnTe Detector and its Front-end-electronics 3.2.2 LSO Block-Detector 3.2.3 Mounting Frame 3.2.4 DAQ Hardware and Software 3.3 Results 3.3.1 Detector Performance 3.3.2 System Performance 3.4 Conclusions 4 Beam Experiments 4.1 Introduction 4.2 Materials and Methods 4.3 Results 4.3.1 Source Test 4.3.2 Beam Profile 4.3.3 Trigger Rate 4.3.4 Pixel Selection in the LSO 4.3.5 Phantom Measurement 4.4 Conclusions 5 Discussion Appendix A A.1 Technical Drawing of the CdZnTe Electrode Layout Bibliography Danksagung Erklärung
94

Interpretace fyzikálních grafů experty a začátečníky sledovaná oční kamerou / Interpretation of physics graphs by experts and novices followed by the eye-tracker

Vondráčková, Terézia January 2020 (has links)
This thesis is focused on identifying key aspects of mechanics graphs regarded by students and experts. It also contains observations of student's attention focused on each graph. This data was collected using eye tracking camera. 23 high school students and 14 experts participated in this research. Our group of experts contained graduate and post-graduate students as well as researchers from faculty of Mathematics and Physics at Charles University. Our results suggest that experts were able to memorize more information from each graph than high school students. Difference in focus on relevant parts of graphs was obvious from analyzing correct and incorrect answers of high school students and they consider axes and their labeling as the key parts of graphs in contrast to the students. Incorrectly answering students were more focused on parts with no relevance to the task in question. On the contrary, students with correct answers spent less time looking on non-relevant parts of graphs. Ideas of incorrectly answering students were mostly focused on wrong idea about graph as a sketch of real situation, or picture resembling physical situation.
95

Automated vehicle follower system based on a monocular camera / Automatiserat fordonsystem for foljning baserat pa en monokular kamera

JOHANSSON, JACOB, SCHRÖDER, JOEL January 2016 (has links)
This report proposes a solution for an automated vehicle follower based on one front-facing monocular camera that can be used to achieve platooning for a lower cost than the systems available on the market today. The sensor will be local to the automated follower vehicle, i.e. no Vehicle-to-Vehicle (V2V) communication. A state-of-the-art chapter describes di erent aspects of platooning, computer vision techniques, state of the art hardware developed especially for autonomous driving as well as systems closely related to the proposed solution. The theory behind the performed implementations such as trajectory, controls, image operations and vehicle models will be presented, followed by a chapter dedicated to the actual implementation. The experimental vehicle used to validate the solution was a modied 1=12 scale radio controlled (RC) car. An Arduino controls the steering and driving motor, and a PC mounted on the vehicle uses a webcam to capture images. The preceding vehicles position relative the follower vehicle was calculated from captured images from the webcam and a trajectory towards the preceding vehicles path was generated from a cubic curve. Measurements from a stereo vision system was used to evaluate the accuracy of the follower vehicle and minimal spacing needed between follower and preceding vehicle. The follower vehicle satisfy the behavior of following a preceding vehicle, but the accuracy of the follower vehicle should be improved to generate a more accurate trajectory before being tested on a larger scale vehicle. The solution shows that a monocular camera can be used to follow a vehicle, and with implementation of a GPS module and a fuzzy velocity controller it could be used to test on a full sized vehicle. / Denna rapport foreslar en losning som gor det mojligt att automatisera ett fordon genom en monokular kamera som foljer en framforvarande ledbil som skulle kunna anvandas inom platooning for en lagre kostnad an de losningar som nns pa marknaden idag. Sensorn ar lokal till det automatiserade fordonet och anvander sig inte utav V2V kommunikation. Ett state-of-the-art kapitel beskriver olika aspekter inom platooning av fordon, datorseende, specikt framtagen hardvara for automatiserade bilar samt automatiserande system som nns inkluderade i bilar idag. Teorin bakom implementationen av bilens trajektoria, reglerteknik, bildbehandlingsoperationer och fordonsmodeller presenteras ocksa. Teorin anvands sedan for att utveckla en prototyp som anvands till att besvara forskningsfragorna. Prototypfordonet ar en modierad radiostyrd bil i skala 1/12. En Arduino styr drivmotor och styrning medan en PC monterad pa bilen anvander sig av en webbkamera for att ta bilder. Ledbilens position relativt foljbilen beraknas med hjalp av bilderna och en bana att folja efter genereras av en tredjegradskurva. Matningar genom ett stereo vision system anvandes for att besvara fragor angaende noggranheten for den utvecklade efterfoljande bilen samt lagsta sakra avstand som kan anvandas mellan bilarna. Den utvecklade prototypbilen foljer efter ledbilen pa ett onskvart satt, dock borde trajektorian som den foljer utvecklas mera innan testning utfors pa storre fordon. Losningen pavisar att en monokular kamera kan anvandas for att folja efter en bil. Om systemet utokas med en GPS modul och en fuzzy hastighetskontroll kan denna losning testas med bilar i full storlek.
96

Characterization and calibration of a Full Stokes polarization camera

Carlsen, Tim, Ehrlich, André, Wendisch, Manfred 30 October 2017 (has links)
Initially unpolarized solar radiation is polarized in the atmosphere due to scattering processes at molecules and aerosols. Therefore, the measurement of the polarization state of solar radiation is of vital importance in remote sensing. A SALSA Full Stokes polarization camera measuring the complete Stokes vectors in real time is characterized within this work. The main focus lies on the radiometric calibration as well as the determination and validation of the calibration matrix based on a Data Reduction method. One main issue is the temporal instability of the calibration matrix, which gives rise to the need of a thorough calibration process. In accordance with theoretical expectations and model simulations, the SALSA Full Stokes polarization camera provides reliable measurement results under the condition of Rayleigh scattering. / Die beim Eintritt in die Atmosphäre unpolarisierte solare Strahlung wird durch Streuprozesse an Molekülen oder Aerosolpartikeln polarisiert. Die Messung des Polarisationszustandes der solaren Strahlung spielt deshalb in der Fernerkundung eine wichtige Rolle. Die vorliegende Arbeit charakterisiert eine SALSA Full Stokes Polarisationskamera, die den kompletten Stokes-Vektor in Echtzeit misst. Das Hauptaugenmerk liegt dabei auf der radiometrischen Kalibrierung sowie der Bestimmung und Validierung der Kalibrationsmatrix über die Methode der Datenreduktion. Die zeitliche Instabilität der Kalibrationsmatrix stellt ein großes Problem dar und stellt Anforderungen an den Umfang der Kalibrierung. Mit der SALSA Full Stokes Polarisationskamera sind zuverlässige Messungen unter einer rayleighstreuenden Atmosphäre möglich, die in Übereinstimmung mit den theoretischen Erwartungen und Modellsimulationen stehen.
97

Vývoj metody vizualizace a měření teplotních polí ve vzduchu pomocí termovize / Development of Method for Visualization and Measuring of Temperature Fields in Air with using Thermovision Camera

Pešek, Martin January 2014 (has links)
This work deals with the measurement of temperature fields in the air using an infrared camera. The dissertation describes the opportunity of measuring the temperature field in the air and the characterization of the developed measuring method. In the next part there are introduced the beginning of thermography imaging and the field of usability of the new infrared measuring method. Further, the theoretical foundations of the thermography measuring method in the temperature fields in the air are described. In the theoretic background there are described the analysis of heat conduction in an auxiliary material, the determination of dynamic properties of the method and the analysis of radiation, which has an influence on infrared imagining. This method requires an insertion of the auxiliary material into the non-isothermal air flow, which can allow for the study of the temperature distribution in air. For effective visualization of temperature fields in the air using an infrared camera, the selection of the appropriate auxiliary material, on which the air temperature displays, is crucial. In the next part of the doctoral thesis, there is a description of static measuring properties of auxiliary materials. The usability range of the measuring method is determined from these properties. In the thesis there are presented the description of the device for the measurement of 2D temperature fields in the air and the description of the measuring device for 3D measurements of temperature fields in the air using an infrared camera, which can also be used for measurements of temperature fields in small enclosed spaces through a viewing window. For the practical use of the method, the detailed methodology of measuring temperature fields in the air by an infrared camera was developed and its applicability was demonstrated on practice examples. The developed measuring method can be used in many areas of research and in practice.
98

Tvorba modelu (jeskyní) pomocí stereokamery / (Cave) Modelling Using Stereocamera

Haša, Jiří January 2009 (has links)
This document focuses on stereoscopic vision, machine vision and 3D scene reconstruction. First we create mathematic framework which is later used to determine solution for problems appearing during creation of scene reconstruction application.
99

SIYA - Slide Into Your Albums : Design and construction of a controllable dolly camera with object recognition / Konstruktion av en automatiserad kamerarigg med objektigenkänning.

Adeeb, Karam, Alveteg, Adam January 2019 (has links)
The scope of this project is to design, construct and build an automated camera rig with object recognition. The project explores if there are any advantages with an automated camera rig compared to a manual one, how an external camera module can be implemented to track an object and under what circumstances the camera module can register the objects for optimal performance. The construction is built to travel along a rail of two iron pipes. A camera is mounted on a small wagon that travels on top of the rail with the help of a DC-motor. On the wagon, an external camera module called Pixy2 detects a predetermined object that the user wants the main camera to detect and focus on. Using the feedback data from the Pixy2, two stepper motors run to rotate the main camera horizontally and vertically so that the object is placed in the middle of the frame while the wagon travels along the rail. / Syftet med detta projekt är att konstruera och bygga en automatiserad kamerarigg med objektigenkänning. Projektet undersöker om det finns några fördelar med en automatiserad kamerarigg gentemot en manuell, hur en extern kameramodul implementeras för att kamerariggen ska kunna följa ett objekt och under vilka förhållanden kameramodulen registrerar objekten bäst. Kamerariggen är byggd för att åka längsmed en räls som består av två järnrör. En filmkamera är monterad på en vagn som rullar ovanpå denna räls och drivs med hjälp av en DC-motor. Ovanpå vagnen ska en extern kameramodul vid namn Pixy2 upptäcka ett förbestämt objekt som användaren vill att filmkameran ska fokusera på. Med hjälp av återkoppling av datan som Pixy2 registrerar styrs två stycken stegmotorer som antingen roterar filmkameran horisontellt i x-led eller vertikalt i y-led tills objektet är placerat i mitten av Pixy2’s synfält. På detta sätt kommer konstruktionen att fokusera på objektet samtidigt som den rör sig i sidled på rälsen.
100

Fimp-bot : Robot för upplockning av cigarettfimpar / Fimp-bot : Robot for collection of cigarette butts

Geiberger, Philipp, Hanna, Ivan January 2019 (has links)
Cirka en miljard cigarettfimpar slängs på svenska gator varje år. Detta leder till risker för både människan och miljön som skulle kunna minskas betydligt med robotar som städar bort fimparna. Denna rapport behandlar ett konstruktionsförslag för en robot som utför just denna uppgift. Med tanke på givna begränsningar utvecklas endast funktionaliteten som krävs för att roboten skall kunna utföra sin uppgift i en idealiserad inomhusmiljö. En prototyp konstrueras för att kunna undersöka precisionen av detektering och upplockning av cigarettfimpar med den valda konstruktionen. För att kunna hitta cigarettfimpar drivs och styrs prototypen med två DC-motorer som är kopplade till separata H-bryggor. En ultraljudssensor upptäcker stora hinder så att prototypen kan undvika dessa. För detekteringen av cigarettfimparna används en Pixy-kamera som identifierar objekt genom att beräkna deras färgsignatur. Upptäcks en cigarettfimp styr prototypen mot denna. Sedan plockas fimpen upp med en mekanism baserad på servomotorer som styrs med en Arduino Uno mikrokontroller. Mekanismen består av en ramp med dörr som fälls ned och genom rampen leder in cigarettfimpen i en behållare. Konstruktionen har till stor del skapats med flertal elektriska komponenter, en byggsats samt i Solid Edge skapade och i 3D-skrivaren Ultimaker utskrivna delar. Resultat av utförda tester visar att Pixy-kameran är en svag punkt då den är väldigt ljuskänslig. Det är också mycket svårare för den att detektera fimpar i standardfärgen orange relativt röda fimpar. Tester av upplockning i goda ljusförhållanden och med röda cigarettfimpar ger 78% framgångskvot vilket visar på att konstruktionen fungerar väl. En framtida utvecklingsmöjlighet som minskade kvoten var dock att prototypen var opålitlig på att köra rakt. / Approximately one billion cigarette butts are thrown onto Swedish streets each year. This leads to risks both for the human and the environment that could be reduced considerably with robots that clean up the cigarette butts. This report deals with a construction proposal for a robot that performs exactly this task. Considering the restraints that this project faces only the functionality is developed that is required for the robot to be able to perform the task in an idealised indoor-environment. A prototype is constructed to be able to examine the precision of detection and collection of the cigarette butts for the chosen construction. To find cigarette butts the prototype is driving and steering with two DC-motors that are connected to separate H-bridges. A ultrasonic sensor detects large obstacles for the prototype to be able to avoid them. For detection of cigarette butts a Pixy-camera is used that identifies objects by calculating their colour signature. When a cigarette butt is detected the prototype steers towards it. Then it picks up the cigarette butt with a mechanism working with servomotors that are controlled by an Arduino Uno microcontroller. This mechanism is made up of a ramp with door that is tilted down onto the ground and leads the butt into a container.The construction was built using mainly multiple electric components, a building kit and parts designed in Solid Edge and 3D-printed in Ultimaker. Results of conducted tests show that the Pixy-camera is a weak spot as it is very light sensitive. Furthermore it is much harder for the camera to detect cigarette butts in standard colour orange compared to red cigarette butts. Tests of the cigarette butt collection performance showed a success ratio of 78% which shows that the construction works well. A future development for the prototype that lowered the success ratio was that it was unreliable at driving straight forward.

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