Global ETD Search

21	Increasing temporal, structural, and spectral resolution in images using exemplar-based priors Holloway, Jason 16 September 2013 (has links) In the past decade, camera manufacturers have offered smaller form factors, smaller pixel sizes (leading to higher resolution images), and faster processing chips to increase the performance of consumer cameras. However, these conventional approaches have failed to capitalize on the spatio-temporal redundancy inherent in images, nor have they adequately provided a solution for finding $3$D point correspondences for cameras sampling different bands of the visible spectrum. In this thesis, we pose the following question---given the repetitious nature of image patches, and appropriate camera architectures, can statistical models be used to increase temporal, structural, or spectral resolution? While many techniques have been suggested to tackle individual aspects of this question, the proposed solutions either require prohibitively expensive hardware modifications and/or require overly simplistic assumptions about the geometry of the scene. We propose a two-stage solution to facilitate image reconstruction; 1) design a linear camera system that optically encodes scene information and 2) recover full scene information using prior models learned from statistics of natural images. By leveraging the tendency of small regions to repeat throughout an image or video, we are able to learn prior models from patches pulled from exemplar images. The quality of this approach will be demonstrated for two application domains, using low-speed video cameras for high-speed video acquisition and multi-spectral fusion using an array of cameras. We also investigate a conventional approach for finding 3D correspondence that enables a generalized assorted array of cameras to operate in multiple modalities, including multi-spectral, high dynamic range, and polarization imaging of dynamic scenes. high speed video compressive sensing flutter shutter video camera FSVC multi-spectral imaging multispectral imaging camera array 3D stereo cross channel point correspondence HDR imaging generalized assorted cameras GAC
22	Untersuchungen zu Trageigenschaften von plattenförmigen Betonleichtbauelementen in Kreuz-Kanal-Technologie Jäger, Wolfram 21 July 2022 (has links) Die Herstellung von Stahlbeton erfordert einen hohen Energie- und Ressourceneinsatz, vor allem im Bereich der Zement- und Stahlproduktion. Stahlbetonbauteile sind gekennzeichnet durch hohe Traglasten, aber auch durch hohe Eigengewichte. Bei Beanspruchung auf Biegung wird Beton eigentlich nur im Bereich der Druckzone und zum Schutz der Bewehrung in der Zugzone benötigt. Dem können sich bisher platten- oder scheibenförmige Bauteile nicht anpassen. Der Beton wird über den gesamten Querschnitt eingesetzt. Natürlich wird er dabei auch zur Übertragung der Schubkräfte zwischen Druck- und Zugzone benötigt. Setzt man ihn über den vollen Querschnitt ein, bringt er einen hohen Anteil an Eigenlast in das Tragmodell ein und damit wird ein Teil der Tragfähigkeit durch die Eigenlast aufgebraucht. [Aus: Motivation und Ziel] / The production of reinforced concrete requires a high input of energy and resources, especially in the area of cement and steel production. Reinforced concrete components are characterised by high load-bearing capacities but also by high dead weights. When stressed in bending, concrete is actually only needed in the compression zone and to protect the reinforcement in the tension zone. Until now, slab or wall-shaped components have not been able to adapt to this. The concrete is used over the entire crosssection. Of course, it is also needed to transmit the shear forces between the compression and tension zones. If it is used over the full cross-section, it introduces a high proportion of dead load into the load-bearing model and thus part of the load-bearing capacity is used up by the dead load. info:eu-repo/classification/ddc/624 ddc:624
23	Cooperative wireless channel characterization and modeling: application to body area and cellular networks Liu, Lingfeng 23 March 2012 (has links) Cooperative wireless communication is an attractive technique to explore the spatial channel resources by coordination across multiple links, which can greatly improve the communication performance over single links. In this dissertation, we study the cooperative multi-link channel properties by geometric approaches in body area networks (BANs) and cellular networks respectively.<p><p>In the part of BANs, the dynamic narrowband on-body channels under body motions are modeled statistically on their temporal and spatial fading based on anechoic and indoor measurements. Common body scattering is observed to form inter-link correlation between links closely distributed and between links having synchronized movements of communication nodes. An analytical model is developed to explain the physical mechanisms of the dynamic body scattering. The on-body channel impacts to simple cooperation protocols are evaluated based on realistic measurements. <p><p>In the part of cellular networks, the cluster-level multi-link COST 2100 MIMO channel model is developed with concrete modeling concepts, complete parameterization and implementation methods, and a compatible structure for both single-link and multi-link scenarios. The cluster link-commonness is introduced to the model to describe the multi-link properties. The multi-link impacts by the model are also evaluated in a distributed MIMO system by comparing its sum-rate capacity at different ratios of cluster link-commonness. / Doctorat en Sciences de l'ingénieur / info:eu-repo/semantics/nonPublished Electricité Sciences exactes et naturelles Wireless communication systems Wireless sensor networks Transmission sans fil Réseaux de capteurs sans fil visibility region capacity channel modeling cooperative wireless communication multiple cylinder scattering Doppler spectrum 2.4 GHz IEEE 802.15.6 UWB COST 2100 channel model MIMO cooperative relay cluster DMC BAN body area network distributed MIMO diversity polarization MPC on-body channel dynamic body scattering surface wave fading shadowing pathloss cross-channel correlation

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