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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

Εκτίμηση βάθους σκηνής από κάμερα τοποθετημένη σε αυτοκίνητο που κινείται

Καπρινιώτης, Αχιλλέας 10 June 2014 (has links)
Στη διπλωματική αυτή εργασία αναλύεται η εκτίμηση του βάθους μίας άκαμπτης σκηνής από κάμερα τοποθετημένη σε αυτοκίνητο που κινείται. Στο κεφάλαιο 1 γίνεται μία εισαγωγή στον τομέα της Υπολογιστικής Όρασης και δίνονται μερικά παραδείγματα εφαρμογών της. Στο κεφάλαιο 2 περιγράφονται βασικές αρχές της προβολικής γεωμετρίας που χρησιμοποιείται ως μαθηματικό υπόβαθρο για τα επόμενα κεφάλαια. Στο κεφάλαιο 3 γίνεται λόγος για το θεωρητικό μοντέλο της κάμερας, των παραμέτρων της και των παραμορφώσεων που υπεισέρχονται στο μοντέλο αυτό. Στο κεφάλαιο 4 αναφέρεται η διαδικασία βαθμονόμησης της κάμερας, μαζί με την υλοποίησή της. Στο κεφάλαιο 5 παρουσιάζονται γενικές κατηγορίες των στερεοσκοπικών αλγορίθμων που χρησιμοποιούνται, καθώς και τα κατάλληλα μέτρα ομοιότητάς τους. Στο κεφάλαιο 6 γίνεται αναφορά στον ανιχνευτή γωνιών Harris και γίνεται η εφαρμογή του τόσο ως προς την ανίχνευση των γωνιών, όσο και ως προς την αντιστοίχιση των 2 εικόνων. Στο κεφάλαιο 7 αναλύεται η θεωρία του αλγόριθμου SIFT και δίνεται ένα παράδειγμα ανίχνευσης και αντιστοίχισης χαρακτηριστικών. Στο κεφάλαιο 8 επισημαίνονται οι βασικές αρχές της επιπολικής γεωμετρίας, καθώς η σημασία της διόρθωσης των εικόνων. Στο κεφάλαιο 9 αναφέρεται η συνολική διαδικασία που ακολουθήθηκε, μαζί με την περιγραφή και την υλοποίηση των μεθόδων εκτίμησης βάθους που χρησιμοποιήθηκαν. / The current master’s thesis analyzes the depth estimation of a rigid scene from a camera attached to a moving vehicle. The first chapter gives an introduction to the field of Computer Vision and provides some examples of its applications. The second chapter describes basic principles of projective geometry that are being used as mathematical background for the next chapters. The third chapter refers to the theoretical modeling of a camera, along with its parameters and the distortions that appear in this model. The forth chapter deals with the camera calibration procedure, along with its implementation. Chapter five presents general categories of stereoscopic algorithms, along with their similarity measures. Chapter six talks about Harris corner detector and its implementation in detecting corners and in the matching process as well. Chapter 7 analyzes the SIFT algorithm theory and gives an example of detecting and matching features. Chapter 8 highlights basic principles of epipolar geometry and stresses out the importance of image rectification. Chapter nine presents the procedure that has been followed, along with the description and implementation of the depth estimation methods that have been used.
172

Kol-14 datering : En litteraturstudie över hur kol-14 isotopen används för datering, samt utveckling och tillämpning av djup-åldersmodeller inom naturgeografin.

Magnusson, Erik January 2013 (has links)
This literature study concerned the use and function of the radioactive isotope carbon-14, as a dating method of organic material, within the scientific field of physical geography. In this report it is presented the need of atmospheric calibration curves and the development of these as a necessity to translate carbon-14 years to calibrated calendar years. A number of common age-depth models that is used to give an approximation of an accumulation sequence and its related dates over the actual time period in different natural archives is presented and discussed. Different problems that commonly occur when age-depth models are utilized as for instance reservoir effects, contaminations or other age deviations are addressed and analyzed. The software CLAM in presented and discussed and was also used to produce age-depth models. In order to test the impact of different age-depth models used to date the immigration of Picea Abies in the Swedish landscape during Holocene, five lake sediment cores and their pollen profiles was remodeled using CLAM. The outcome of the remodeling suggest that the impact of choosing “wrong” age-depth model was of little importance for these chosen lakes, as the deviating ages between the statistically best and the statistically worst model, was just 2% on average. Calendar years derived from carbon-14 dating should not be considered an absolute truth as it is always an uncertainty involved, and the choice of age-depth model for dating a sequence should be based on scientific knowledge of the actual area.
173

Factors affecting meiofaunal colonization and assemblage structure in marine soft sediments

Boeckner, Matthew J. Unknown Date
No description available.
174

The potential of forest floor transfer for the reclamation of boreal forest understory plant communities

Fair, Jordana Michelle Unknown Date
No description available.
175

THERMOBAROMETRY OF METAMORPHOSED PSEUDOTACHYLYTE AND DETERMINATION OF SEISMIC RUPTURE DEPTH DURING DEVONIAN CALEDONIAN EXTENSION, NORTH NORWAY

Leib, Susan E. 01 January 2013 (has links)
Crustal faulting has long been known as the source of shallow seismicity, and the seismogenic zone is the depth (3-15 km) within the crust that is capable of co-seismic slip, largely under brittle conditions. However, some continental seismicity occurs at depths >> 15 km. I performed thermobarometry of mylonitic pseudotachylyte to determine the P-T of a seismogenic extensional fault in the Caledonian Norwegian margin. Two shear zones (Eidsfjord and Fiskfjord) located in northern Norway exhibit brittle extension propagating into the ductile regime of the lower crust as evidenced by the presence of pseudotachylyte. Averages from Eidsfjord (653 ± 38°C and 570 ± 115 MPa) and Fiskfjord (680 ± 70°C and 1121 ± 219 MPa) correspond to depths of co-seismic slip of 21 ±4 km and 41 ± 9 km, respectively. These depths are 5-25 km below the depth of the standard seismogenic zone in mature fault systems, and require another mechanism (e.g. dynamic downward rupture, unusually high shear stresses) to account for seismogenic rupture at such depths. Assuming Eidsfjord and Fiskfjord were uplifted at the same time, and considering they are currently at the same crustal level, Fiskfjord was uplifted a greater amount and at a faster rate as it was initially located at a greater crustal depth.
176

Ground freeze-thaw, snow and roads in northern Sweden

Sarady, Maria January 2014 (has links)
In this thesis freeze-thaw along roads in northern Sweden is examined. The examinations are put in a context of changing climate and its amplification towards the Arctic region on earth. The research focuses on the impact of a warmer climate on ground freeze-thaw and in exten- sion road maintenance in the region. The investigation is presented through two scientific papers, where the first examines how ground temperatures are developed during a single frost season experiment, where a natural accumulation of snow cover and a continual removal of snow cover occur respectively. In the second paper, ground temperature data from sub-Arctic Sweden that has been logged by the Swedish Transport Administration, has been collected and freeze-thaw cycles have been calculated and analysed. The results are related to regional landscape factors and are in the context of regional climate change discussed to reach understanding of challenges for road maintenance in the region and opportunities to reach resilience. The results in Paper 1 show that also a thin cover of snow has impact on the freeze-thaw frequency, duration and intensity that occur in and on the surface of the ground. Furthermore the results show that the ground temperatures rise in due to an increase in snow cover amounts and that this process occurs in several steps. Paper 2 shows that the occurrence of ground freeze-thaw is affected by the proximity to open waters. Warmer temperatures in the air may cause later ice freeze-up and earlier ice break-up on lakes, rivers and on the Gulf of Bothnia and roads in northern Sweden are in general situated on the coast or near rivers. Ground temperatures around 0 °C has a high negative impact on road stability and a warmer and wetter climate in northern Sweden may thus increase road deterioration. The economic development in Sweden stays dependent on extraction of natural resources in sub-Arctic Sweden and thus it is of major concern to main- tain and improve road infrastructure in the region.
177

捷克非營利組織的公共關係策略: 以「People in Need」為例 / Public Relations of Czech NPO: Case of “People in Need”

韋嘉敏, Veronika Tomanova Unknown Date (has links)
捷克非營利組織的公共關係策略: 以「People in Need」為例 / This study deals with the topic of public relations in the context of the nonprofit sector in Czech Republic. It focuses on the Czech NPO People in Need, established shortly after the Fall of communism with aim to facilitate humanitarian aid and has grown into one of the largest NPOs in Central and Eastern Europe over the past two decades. The aim of this study is to monitor how People in Need uses public relations in order to support their organizational goals. The research covers the communication channels and the strategies used by People in Need to communicate with the public, the ways NPO access the media relations and the reflection of the cooperation between journalists and NPO representatives. Data for this qualitative study were gathered employing technique of in-depth interviews.
178

Vergence eye movements and dyslexia

Riddell, Patricia Mary January 1987 (has links)
No description available.
179

Holistic Education: The Flow and Pulse of Learning

Nigh, Kelli 11 January 2012 (has links)
Situated in the holistic education field, this research explores the mind/body experiences of six youth who remained in a drama group from the time they were children to their late adolescence. In the first phase of this research these participants reflected on their experiences of the imagination, thought and felt sensation as they engaged in meditation and mind/body warm-up exercises during the drama years. The participants applied their understanding of mind/body awareness to a question posed by Vivian Darroch-Lozwoski; what happens when we attend to nature feelingly? Over the course of one year, the youth explored the above question, individually and collectively through dreaming, reveries, the imagination, experiences of energy and as they wandered in nature. The inquiry directly addresses the existential, ontological and epistemological implications of holistic mind/body development and outlines approaches for gentling the mind and body to nature.
180

Holistic Education: The Flow and Pulse of Learning

Nigh, Kelli 11 January 2012 (has links)
Situated in the holistic education field, this research explores the mind/body experiences of six youth who remained in a drama group from the time they were children to their late adolescence. In the first phase of this research these participants reflected on their experiences of the imagination, thought and felt sensation as they engaged in meditation and mind/body warm-up exercises during the drama years. The participants applied their understanding of mind/body awareness to a question posed by Vivian Darroch-Lozwoski; what happens when we attend to nature feelingly? Over the course of one year, the youth explored the above question, individually and collectively through dreaming, reveries, the imagination, experiences of energy and as they wandered in nature. The inquiry directly addresses the existential, ontological and epistemological implications of holistic mind/body development and outlines approaches for gentling the mind and body to nature.

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