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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.
101

Proposta de linguagem geradora de imagens em impressoras de página / A page description language for raster non impact printers.

Mario Antonio Stefani 16 August 1990 (has links)
Uma compacta linguagem descritora de páginas, destinada a impressoras não-impacto de estrutura raster é apresentada. Tal linguagem foi implementada usando o processador gráfico TMS4010, da Texas Instruments e possui uma estrutura muito similar à encontrada nas linguagens interpretativas encadeadas. A linguagem é totalmente modular e interativa, e se utiliza um modelo gráfico simples, visando simular as tarefas normalmente encontradas nas artes tipográficas. São efetuadas comparações com outras linguagens comerciais, visando avaliar suas possibilidades. Uma pequena introdução à tecnologia das impressoras laser é apresentada. / A small Page description language intended for raster non-impact printers is presented. The language is implemented using the Texas Instruments TMS4010 Graphics system processor and its structure is similar that encountered in threaded interpretative languages. The language is fully modular and interactive, and uses a simple graphic model to simulate the same common tasks encoutered in typographical arts. Comparison are made with other comercial languages to perform some evaluations on its possibilities. A small introduction on the laser printer technology is presented.
102

Efficient Feature Extraction for Shape Analysis, Object Detection and Tracking

Solis Montero, Andres January 2016 (has links)
During the course of this thesis, two scenarios are considered. In the first one, we contribute to feature extraction algorithms. In the second one, we use features to improve object detection solutions and localization. The two scenarios give rise to into four thesis sub-goals. First, we present a new shape skeleton pruning algorithm based on contour approximation and the integer medial axis. The algorithm effectively removes unwanted branches, conserves the connectivity of the skeleton and respects the topological properties of the shape. The algorithm is robust to significant boundary noise and to rigid shape transformations. It is fast and easy to implement. While shape-based solutions via boundary and skeleton analysis are viable solutions to object detection, keypoint features are important for textured object detection. Therefore, we present a keypoint featurebased planar object detection framework for vision-based localization. We demonstrate that our framework is robust against illumination changes, perspective distortion, motion blur, and occlusions. We increase robustness of the localization scheme in cluttered environments and decrease false detection of targets. We present an off-line target evaluation strategy and a scheme to improve pose. Third, we extend planar object detection to a real-time approach for 3D object detection using a mobile and uncalibrated camera. We develop our algorithm based on two novel naive Bayes classifiers for viewpoint and feature matching that improve performance and decrease memory usage. Our algorithm exploits the specific structure of various binary descriptors in order to boost feature matching by conserving descriptor properties. Our novel naive classifiers require a database with a small memory footprint because we only store efficiently encoded features. We improve the feature-indexing scheme to speed up the matching process creating a highly efficient database for objects. Finally, we present a model-free long-term tracking algorithm based on the Kernelized Correlation Filter. The proposed solution improves the correlation tracker based on precision, success, accuracy and robustness while increasing frame rates. We integrate adjustable Gaussian window and sparse features for robust scale estimation creating a better separation of the target and the background. Furthermore, we include fast descriptors and Fourier spectrum packed format to boost performance while decreasing the memory footprint. We compare our algorithm with state-of-the-art techniques to validate the results.
103

Tvorba konceptu category managementu / Creating the Concept of Category Management

Lepař, Martin January 2012 (has links)
The goal of this thesis is to define proces of creating the concept of category management and to apply the proces via existing assortment concept of certain retail company. The theoretical part covers basics of category management, merchandising and other related disciplines and its influence to creating concepts. Practical part includes detailed description of creating the concept, realized by retail company, selling Do it yourself products. Creation proces will start by anylysing current sutiation, following by determination of category strategy and objectives and implemetation of new concept.
104

GIS využití krajiny obce Jinačovice / Land use GIS of Jinačovice municipality

Kelblová, Kristýna January 2013 (has links)
This master thesis focuses on the development of the GIS in the Jinačovice municipality, particularly on the land use. The core data used for the research has been gathered by aerial photography since 1950. Other data sources include other types of maps, especially Cadastral map, ZABAGED data and statistical data. An analysis of the Land use has been carried out as well as additional analyses of the area. The research has been conducted specifically for the Jinačovice municipality.
105

Elektrochemische Metallabscheidung mit Kapillarsonden

Müller, Anne-Dorothea 09 April 2001 (has links)
Es wird ein Verfahren zur lokalisierten elektrochemischen Abscheidung metallischer Strukturen aus Kapillarsonden vorgestellt. Der experimentelle Aufbau, die Herstellung der Sonden, das Arbeiten im Nahfeld der Probe (Scherkraft-Abstandsdetektion)sowie die verschiedenen Beschaltungmöglichkeiten der elektrochemischen Zelle werden ausführlich beschrieben. Ergänzend zu den experimentellen Arbeiten werden einerseits numerische Simulationen gezeigt, die zur Veranschaulichung der Potentialverteilung in der Apexregion dienen und qualitativ beschreiben, wie sich das Schichtdickenprofil der abgeschiedenen Strukturen mit den einstellbaren Parametern (Elektrodenpotentiale, Spitze-Probe-Abstand) variieren läßt. Andererseits werden die verschiedenen Beschaltungsmöglichkeiten der Zelle anhand von Schaltungssimulationen verglichen und so die Wahl des günstigsten Arbeitspunktes für die in den Experimenten verwendete (bi)-potentiostatische Abscheidung diskutiert. Mit dieser Anordnung wurden lokalisiert Cluster in einer porösen Aluminiumoxidmembran deponiert und anschließend abgebildet. In weiteren Strukturierungsversuchen wurden Kupfer bzw. Gold lokalisiert elektrochemisch auf ITO abgeschieden, wobei das Schichtwachstum simultan optisch in Transmission beobachtet wurde. Es werden u.a. Strukturen erzeugt, deren laterale Abmessungen kleiner als der Kapillardurchmesser sind (Fokussierung, max. Verhältnis 8:1). Die derzeit kleinsten elektrochemisch erzeugbaren Strukturen haben eine laterale Ausdehnung von ca. 5 Mikrometern. / A method for the localized electrochemical deposition of metal structures using capillary tips is presented. The experimental set-up, the tip preparation, the distance detection in near-field operation (shear-force detection), as well as the different types of circuiting of the electrochemical cell are described in detail. In addition to the experimental work, numerical simulations for the qualitative visualization of the potential distribution around the apex region show, how the films thickness profile can be adjusted with the variable parameters (electrode voltages, tip-sample distance). Circuit simulations of the electrochemical cell allow to pre-estimate the optimum working conditions for the used (bi)-potentiostatic electrode set-up. With this method, clusters have been deposited in a thin film of porous alumin oxide and imaged in shear-force mode. Gold and copper structures have been deposited on ITO, while the film growth was observed optically. The lateral dimension of the deposited structures can be smaller than the inner diameter of the capillaries (maximum focus: 8:1). The smallest structures produced in this work have lateral dimensions of 5 micrometers.
106

Zur Erzeugung hochauflösender datenschutzkonformer Mischrasterkarten

Dießelmann, Markus, Meinel, Gotthard January 2013 (has links)
Die zunehmende Verfügbarkeit adressbezogener Daten im Zusammenhang mit der Nutzung geometrischer Raster zur Raumuntergliederung haben die Voraussetzungen für kleinräumige Analysen deutlich verbessert. Bei der Verwendung personenbezogener Daten müssen datenschutzrechtliche Vorgaben eingehalten werden, falls die Rasterzellen zu wenig Fallzahlen enthalten. Vielfach werden diese Rasterzellen ausgeblendet, wodurch Informationen in der Karte verloren gehen. Eine datenschutzkonforme Alternative stellt die Aggregation von Rasterzellen dar, bis die Fallzahlen einen vorgegebenen Grenzwert überschreiten. In diesem Beitrag werden Möglichkeiten vorgestellt und bewertet, nach denen sich datenschutzkonforme Mischrasterkarten erzeugen lassen. Besonderes Augenmerk wird auf die Auflösungsverluste der erzeugten Mischrasterkarten gelegt, um geeignete Datengrundlagen für kleinräumige Analysen zu schaffen.
107

Haftkräfte zwischen technisch rauen Oberflächen

Fritzsche, Jörg 07 October 2016 (has links)
Die eingereichte Dissertation beschäftigt sich mit der messtechnischen Erfassung sowie der Modellierung von Haftkräften zwischen rauen Oberflächen. Dabei wurden durch Variation von Flüssigkeiten sowie dem Nutzen beschichteter Oberflächen verschiedene Benetzungseigenschaften eingestellt und untersucht. Zusätzlich wurden neben dem Kontaktwinkel der untersuchten Systeme die freien Ober- und Grenzflächenenergien bestimmt und mit den Kräften korreliert. Es zeigte sich, dass Haftkräfte auf rauen Oberflächen stets über mehrere Größenordnungen verteilt vorliegen. Die Beschreibung der ermittelten Verteilungen ist dabei entweder durch statistischer Funktionen oder zumindest teils auch durch eine im Rahmen der Arbeit entwickelten Modellierung möglich. Weiterhin zeigte sich, dass eine Unterteilung in verschiedene Haftmechanismen (durch Kapillarbrücken oder van der Waals- sowie polare Wechselwirkungen) vorgenommen werden kann. Kapillarbrücken bilden dabei die größten Kräfte aus. Sie entstehen auf Grund nanoskaliger Blasen (Nanobubbles), welche vor allem auf schlecht benetzenden Oberflächen existieren.
108

Einblendungen. Eine deutsch-jüdische Filmgeschichte in fünf Teilen

Praetorius-Rhein, Johannes, von Haselberg, Lea Wohl 17 June 2020 (has links)
No description available.
109

Study of the hydrothermal aging of Pd/γ-Al2O3 catalysts for lean CO oxidation

Revilla Nebreda, María Consuelo 31 July 2023 (has links)
To limit the environmental impact from fuel based transport of goods and mobility, the knowledge-based improvement of the hydrothermal long-term stability of Pd exhaust catalysts is demanded. Thus, the present study evaluates the performance of hydrothermally aged Pd/gamma-Al2O3 powder catalysts on lean CO oxidation (60-200°C) in the presence of H2O, and discusses structure-activity correlations. A decline in the number of Pd surface sites is quantified with growing aging temperature (650-950°C), and correlates with the decrease in the CO oxidation activity in transient state. However, unexpected shifts in the activation energy of the steady state CO oxidation are observed for the different aging temperatures and total time on stream. The characterization of the active Pd sites of the aged and non-aged catalysts before and after the CO oxidation indicate that the oxidation state of Pd changes during the lean and wet CO oxidation. The observed trends of the oxidation state of Pd correlate with the determined variations of the activation energy, successfully elucidating structure sensitivity of the CO oxidation at temperatures of 750°C or higher, and with changing total time on stream.:1 Introduction and aims 2 Fundamentals 2.1 Emissions from combustion engines 2.2 Diesel exhaust after-treatment systems 2.3 Pd catalysts for CO oxidation 2.3.1 Characterization and CO oxidation activity of Pd catalysts 2.3.2 Mechanism of the CO oxidation on Pd catalysts 2.3.3 Influence of H2O on the CO oxidation on Pd catalysts 2.3.4 Structure sensitivity of the CO oxidation on Pd catalysts 2.4 Thermal and hydrothermal aging of supported Pd catalysts 2.4.1 Sintering and phase transformations of γ-Al2O3 2.4.2 Sintering of Pd in supported catalysts 2.4.3 Kinetic modelling of the CO oxidation on aged Pd catalysts 3 Materials and methods 37 3.1 Preparation of the Pd/γ-Al2O3 catalyst 3.2 Hydrothermal aging of the catalyst 3.3 Performance of the catalytic CO oxidation 3.3.1 Temperature-programmed CO oxidation 3.3.2 Steady state CO oxidation 3.4 Characterization of the catalysts 3.4.1 N2 physisorption 3.4.2 Temperature-programmed desorption of H2 3.4.3 Scanning transmission electron microscopy 3.4.4 X-ray diffraction 3.4.5 X-ray photoelectron spectroscopy 4 Results and discussion 4.1 Transient CO oxidation activity of the non-aged and aged Pd/γ-Al2O3 catalysts 12 Contents 4.2 Quantification of the active sites of the non-aged and aged Pd/γ-Al2O3 catalysts 4.2.1 Number of Pd surface sites 4.2.2 Pd particle sizes 4.2.3 Pd crystallite sizes 4.2.4 Content of surface Pd 4.2.5 Comparative discussion of the quantification of the active sites 4.3 Investigation of the aging mechanism of the Pd/γ-Al2O3 catalysts 4.4 Steady state CO oxidation kinetics of the non-aged and aged Pd/γ-Al2O3 catalysts 4.4.1 Activation energy of the steady state CO oxidation and discussion of structure sensitivity 4.4.2 Dispersion of Pd after the steady state CO oxidation 4.4.3 Oxidation state of Pd after the steady state CO oxidation 4.4.4 Comparative discussion of the transient and steady state CO oxidation activity 4.5 Summarizing discussion of the structure-activity correlations of the nonaged and aged Pd/γ-Al2O3 catalysts for CO oxidation 5 Conclusions and outlook Bibliography List of Figures List of Tables A Annexes
110

Determination of the actual morphology of core-shell nanoparticles by advanced X-ray analytical techniques: A necessity for targeted and safe nanotechnology

Müller, Anja 07 April 2022 (has links)
Obwohl wir sie oft nicht bewusst wahrnehmen, sind Nanopartikel heutzutage in den meisten Bereichen unseres Alltags präsent, unter anderem in Lebensmitteln und ihren Verpackungen, Medizin, Medikamenten, Kosmetik, Pigmenten und in elektronischen Geräten wie Computermonitoren. Ein Großteil dieser Partikel weist, beabsichtigt oder unbeabsichtigt, eine Kern-Schale Morphologie auf. Einfachheitshalber wird diese Morphologie eines Kern-Schale-Nanopartikels (CSNP) oft als ideal angenommen, d.h. als ein sphärischer Kern, der komplett von einer Schale homogener Dicke bedeckt ist, mit einer scharfen Grenzfläche zwischen Kern- und Schalenmaterial. Außerdem wird vielfach auch davon ausgegangen, alle Partikel der Probe hätten gleiche Schalendicken. Tatsächlich weichen die meisten realen CSNPs in verschiedenster Weise von diesem Idealmodell ab, mit oft drastischen Auswirkungen darauf, wie gut sie ihre Aufgabe in einer bestimmten Anwendung erfüllen. Das Thema dieser kumulativen Doktorarbeit ist die exakte Charakterisierung der wirklichen Morphologie von CSNPs mit modernen Röntgen-basierten Methoden, konkret Röntgen-Photoelektronen-Spektroskopie (XPS) und Raster-Transmissions-Röntgen-Mikroskopie (STXM). Der Fokus liegt insbesondere auf CSNPs, die von einer idealen Kern-Schale-Morphologie abweichen. Aufgrund der enormen Vielfalt an CSNPs, die sich in Material, Zusammensetzung und Form unterscheiden, kann eine Messmethode nicht völlig unverändert von einer Probe auf eine andere übertragen werden. Nichtsdestotrotz, da die als Teil dieser Doktorarbeit präsentierten Artikel eine deutlich ausführlichere Beschreibung der Experimente enthalten als vergleichbare Publikationen, stellen sie eine wichtige Anleitung für andere Wissenschaftler dafür dar, wie aussagekräftige Informationen über CSNPs durch Oberflächenanalytik erhalten werden können. / Even though we often do not knowingly recognize them, nanoparticles are present these days in most areas of our daily life, including food and its packaging, medicine, pharmaceuticals, cosmetics, pigments as well as electronic products, such as computer screens. The majority of these particles exhibits a core-shell morphology either intendedly or unintendedly. For the purpose of practicability, this core-shell nanoparticle (CSNP) morphology is often assumed to be ideal, namely a spherical core fully encapsulated by a shell of homogeneous thickness with a sharp interface between core and shell material. It is furthermore widely presumed that all nanoparticles in the sample possess the same shell thickness. As a matter of fact, most real CSNPs deviate in several ways from this ideal model with quite often severe impact on how efficiently they perform in a specific application. The topic of this cumulative PhD thesis is the accurate characterization of the actual morphology of CSNPs by advanced X-ray analytical techniques, namely X-ray photoelectron spectroscopy (XPS) and scanning transmission X-ray microscopy (STXM). A special focus is on CSNPs which deviate from an ideal core-shell morphology. Due to the vast diversity of nanoparticles differing in material, composition and shape, a measurement procedure cannot unalteredly be transferred from one sample to another. Nevertheless, because the articles in this thesis present a greater depth of reporting on the experiments than comparable publications, they constitute an important guidance for other scientists on how to obtain meaningful information about CSNPs from surface analysis.

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