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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.
11

Applications of demand analysis for the dairy industry using household scanner data

Stockton, Matthew C. 17 February 2005 (has links)
This study illustrates the use of ACNielsen Homescan Panel (HSD) in three separate demand analyses of dairy products: (1) the effect of using cross-sectional data in a New Empirical Industrial Organization (NEIO) study of ice cream firm mergers in San Antonio; (2) the estimation of hedonic price models for fluid milk by quart, halfgallon and gallon container sizes; (3) the estimation of a demand system including white milk, flavored milk, carbonated soft drinks, bottled water, and fruit juice by various container sizes. In the NEIO study a standard LA/AIDS demand system was used to estimate elasticities evaluating seven simulated mergers of ice cream manufactures in San Antonio in 1999. Unlike previously published NEIO work, it is the first to use crosssectional data to address the issue associated with inventory effects. Using the method developed by Capps, Church and Love, none of the simulated price effects associated with the mergers was statistically different from zero at the 5% confidence level. In 1995 Nerlove proposed a quantity-dependent hedonic model as a viable alternative to the conventional price-dependent hedonic model as a means to ascertain consumer willingness to pay for the characteristics of a given good. We revisited Nerlove’s work validating his model using transactional data indigenous to the HSD. Hedonic models, both price-dependent and quantity-dependent, were estimated for the characteristics of fat content, container type, and brand designation for the container sizes of gallon, half- gallon, and quart. A rigorous explanation of the interpretation between the estimates derived from the two hedonic models was discussed. Using the Almost Ideal Demand System (AIDS), a matrix of own-price, crossprice, and expenditure elasticities was estimated involving various container sizes of white milk, flavored milk, carbonated soft drinks, bottled water, and fruit juices, using a cross-section of the 1999 HSD. We described price imputations and the handling of censored observations to develop the respective elasticities. These elasticities provided information about intra-product relationships (same product but different sizes), intrasize relationships (different products same container size), and inter-product relationships (different products and different sizes). This container size issue is unique in the extant literature associated with non-alcoholic beverage industry.
12

Household- and Market-Level Perspectives on the Peter Pan Peanut Butter Recall Using Nielsen Homescan Panel Data

Bakhtavoryan, Rafael 2011 December 1900 (has links)
Using household level scanner data for 2006, 2007, and 2008, this dissertation consists of four studies, which present household- and market-level analyses of food safety issues concerning the 2007 Peter Pan recall on the demand for peanut butter at the category level and at the brand level. Findings of the first study suggested that the recall had a statistically significant positive effect on the demand for peanut butter at the category level. At the brand level, spillover effects were evident in that the demand for Jif was positively affected, while the demand for Skippy was negatively affected. The second study examined structural change in the demand for peanut butter using demand system models corresponding to the pre-recall and the post-recall periods. Matrices of own-price, cross-price, and expenditure elasticities were calculated for both recall periods, and upon comparison, there were statistical differences in the corresponding estimated elasticities. In general, most price elasticities in the post-recall period were larger in absolute value than the comparable elasticities in the pre-recall period. The third study investigated the impact of household socio-economic characteristics associated with choices to purchase peanut butter across the pre- and the post-recall periods. Four choice scenarios were no buy-no buy, buy-no buy, no buy-buy, and buy-buy. Socio-economic characteristics considered included age, employment, education, race, ethnicity, presence of male and/or female household head, region, age and presence of children in the household, household size, and income. While the results varied by brand, region was the socio-demographic characteristic that was consistently significant among the choice scenarios for the respective peanut butter brands. Conditional on households purchasing peanut butter in both the pre- and the post-recall periods, the final analysis examined the influence of the same aforementioned socio-economic variables as well as the change in the own price on the change in the quantity purchased. The results varied across brands, but the principal drivers of the conditional change in the quantity purchased were the change in the own price and the age and presence of children in the household.
13

Assessment of Flatbed Scanner Method for Quality Assurance Testing of Air Content and Spacing Factor in Concrete

Nezami, Sona 16 July 2013 (has links)
The flatbed scanner method for air void analysis of concrete is investigated through a comparison study with the standard ASTM C457 manual and Rapid Air 457 test methods. Air void parameters including air content and spacing factor are determined by image analysis of a large population of scanned samples through contrast enhancement and threshold determination procedures. It is shown that flatbed scanner method is giving comparable results to manual and Rapid Air 457 methods. Furthermore, a comparison of the air void chord length distributions obtained from the two methods of flatbed scanner and Rapid Air 457 has been implemented in this research. The effect of having different settings in the scanning process of scanner method is also investigated. Moreover, a threshold study has been performed that showed the flatbed scanner method can be employed in combination with manual and Rapid Air 457 methods as a time and cost saving strategy.
14

Assessment of Flatbed Scanner Method for Quality Assurance Testing of Air Content and Spacing Factor in Concrete

Nezami, Sona 16 July 2013 (has links)
The flatbed scanner method for air void analysis of concrete is investigated through a comparison study with the standard ASTM C457 manual and Rapid Air 457 test methods. Air void parameters including air content and spacing factor are determined by image analysis of a large population of scanned samples through contrast enhancement and threshold determination procedures. It is shown that flatbed scanner method is giving comparable results to manual and Rapid Air 457 methods. Furthermore, a comparison of the air void chord length distributions obtained from the two methods of flatbed scanner and Rapid Air 457 has been implemented in this research. The effect of having different settings in the scanning process of scanner method is also investigated. Moreover, a threshold study has been performed that showed the flatbed scanner method can be employed in combination with manual and Rapid Air 457 methods as a time and cost saving strategy.
15

Entwicklung eines Lasertrackersystems mit Galvanometerscanner zur 3D-Positionsbestimmung

Wachten, Christian January 2009 (has links)
Zugl.: Freiburg (Breisgau), Univ., Diss., 2009
16

Real-time 3D scanning

Weise, Thibaut January 2009 (has links)
Zugl.: Zürich, Techn. Hochsch., Diss., 2009
17

Klassifikationsverfahren zur Materialerkennung Grenzschichterkennung mittels laserinduzierter Fluoreszenez in mineralischen Lagerstätten am Beispiel der Braunkohlegewinnung /

Bayer, Arne Kristoffer. Unknown Date (has links) (PDF)
Techn. Hochsch., Diss., 2004--Aachen.
18

Low-cost bimorph adaptive mirrors

Ellis, Edric Mark January 1999 (has links)
This thesis describes the modeling and manufacture of bimorph mirrors as well as an example of their application. A general review of adaptive optics is provided, paying particular attention to those technologies which would allow adaptive optics to be employed in non-astronomical situations. The first stage of the theoretical analysis of the bimorph mirror involves developing a mechanical model of the laminated structure. This is carried out using standard thin plate laminate theory; this results in expressions for the overall sensitivity of a bimorph mirror. The mechanical model also leads to an equation describing the response of the surface of the mirror to a given applied voltage. An analytical solution is developed, and its implementation described. Using this analytical solution, the performance of a bimorph mirror under various operating conditions is analysed. Particular attention is paid to the case of correcting phase fluctuations that have a Kolmogorov spectrum. The process of manufacturing bimorph mirrors is described in some detail, and results of this procedure are presented. Results from various bimorph mirrors are analysed, and the comparisons with the theory are presented. A possible use of bimorph mirrors in laser scanner systems is described. A simple demonstration system is described, and results from its operation are presented. A detailed design for a laser printer using adaptive optics is presented, along with the associated deformable mirror requirements.
19

Avaliação da qualidade posicional planimétrica de dados Lidar em duas áreas urbanas no município do Recife/PE

Silva, Mirele Viegas da 04 June 2014 (has links)
Submitted by Amanda Silva (amanda.osilva2@ufpe.br) on 2015-03-05T15:17:55Z No. of bitstreams: 2 DISSERTAÇÃO Mirele Viegas da Silva.pdf: 7784954 bytes, checksum: 56193e4339b0daaaa3548129ff171819 (MD5) license_rdf: 1232 bytes, checksum: 66e71c371cc565284e70f40736c94386 (MD5) / Made available in DSpace on 2015-03-05T15:17:55Z (GMT). No. of bitstreams: 2 DISSERTAÇÃO Mirele Viegas da Silva.pdf: 7784954 bytes, checksum: 56193e4339b0daaaa3548129ff171819 (MD5) license_rdf: 1232 bytes, checksum: 66e71c371cc565284e70f40736c94386 (MD5) Previous issue date: 2014-06-04 / O laser scanner aerotransportado, ALS (Airborne Laser Scanner), também conhecido como LIDAR (Light Detection and Ranging), consiste atualmente numa das tecnologias mais utilizadas para a aquisição de enormes volumes de dados num curto período de tempo. Essa tecnologia envolve a emissão de um pulso eletromagnético em direção à superfície tendo como produto as coordenadas plani-altimétricas e a intensidade do feixe refletido pelo objeto atingido. A posição tridimensional somente pode ser calculada, se em qualquer momento, a posição e orientação do sistema de laser se façam conhecidos com respeito a um sistema de coordenadas, isso é possível devido ao fato que o sistema dispõe de GPS (Global Positioning System)/GNSS (Global Navigation Satellite System) e INS (Inertial Navigation System), auxiliando diretamente no georreferenciamento das imagens e nuvens de pontos adquiridas. O conjunto de dados do laser scanner é uma alternativa poderosa para ser aplicado na otimização de técnicas de mapeamento fotogramétrico, permitindo um ótimo desempenho para extrair informação espacial tridimensional. A imagem fotogramétrica permite, por sua vez, a extração exata de feições planimétricas. Este trabalho descreve uma metodologia para avaliar feições planimétricas em áreas urbanas obtidas com a tecnologia laser scanner aerotransportado tendo, como objetivo, estudar a qualidade posicional planimétrica das feições pontuais em imagens provenientes do laser scanner (imagens de intensidade), através da comparação da saída de dados deste com os dados provenientes do método fotogramétrico aéreo e topográfico. Na presente pesquisa, foi concentrada a detecção principalmente de feições planimétricas de telhados e arruamentos. O método de avaliação da acurácia foi baseado na análise de pontos e medidas de feições lineares obtidas com imagens de intensidade do sistema laser scanner comparadas com medidas obtidas em levantamento GNSS e restituição fotogramétrica de duas áreas localizada no Campus da Universidade Federal de Pernambuco e no bairro da Macaxeira, município de Recife/PE, avaliando de acordo com o Padrão de Exatidão Cartográfico para Produtos Cartográficos Digitais – PEC PCD.
20

Bestimmung der Dichte des Bodens: Einsatz optischer 3D-Messverfahren zur Volumenbestimmung unregelmäßiger Geometrien im Erdbau

Wendt, Enrico, Thiele, Ralf 19 October 2021 (has links)
Zumeist sind Gründungen horizontal eben hergestellte Flächen, dessen Nachweis über die direkte Ermittlung der Dichte im Feld durch verschiedene Verfahren, wie z.B. Flüssigkeitsersatz-Verfahren, sichergestellt ist. Jedoch gibt es auch komplexe Körper im Erdbau, wie z.B. bei der Herstellung eines Rohrzwickelbereichs bei wassergeführten Leitungen, welche bisher nur mit indirekten Aufschlussverfahren nachgewiesen werden konnten. Aufgrund von Entwicklungen neuer Technologien zum Einbau von Rohrleitungen, könnte die Bettung zukünftig direkt in einer formgebenden Verdichtung stattfinden. Die Wirkung einer solchen Herstellung wird in ersten Zügen in dieser Arbeit untersucht. Dafür wird die Wirksamkeit eines Vibrationsverdichters zur formgebenden Verdichtung überprüft. Da es sich hierbei um die ersten Versuche mit dem Prototypen auf freier Arbeitsfläche handelt, müssen noch weitere Versuche mit Verbesserungen des Geräts vorgenommen werden. Um die Verdichtungswirkung des Vibrationsverdichters überprüfen zu können, wurde in dieser Arbeit ein optisches Messverfahren zur direkten Dichtebestimmung entwickelt, da dies über herkömmliche Methoden bei unregelmäßigen Körpern im Erdbau nicht möglich ist. Dafür wird eine gesicherte Arbeitsumgebung hergestellt und die Dichte mit einem handgeführten 3D-Scanner nachgewiesen. Die Versuche mit dem optischen Messverfahren haben im Vergleich zu den herkömmlichen Dichtebestimmungs-Methoden eine sehr hohe Genauigkeit aufgewiesen. Außerdem konnte der 3D-Scanner bei der Analyse von unregelmäßigen Erdkörpern überzeugen, weshalb es das Potential hat, eine reelle Ergänzung der Verfahren zur In-situ Dichtebestimmung zu werden, um die bestehende geotechnische Lücke zu schließen. Weiterführende Forschungen könnten sich mit einer verbesserten formgebenden Verdichtung und dessen Auswertung über das optische Messverfahren beschäftigen.:1 Überblick und Ziele 2 Ausgangslage 3 Stand der Technik 4 Auswahl und Umgang mit dem Probeboden 4.1 Klassifizierung 4.2 Möglichkeiten zum reproduzierbaren lockeren Einbau feuchter Bodenproben 4.3 Homogenitätsprüfung 4.4 Zusammenfassung der Materialkennwerte 5 Herkömmliche Verfahren zur Dichtebestimmung 5.1 Vergleich am Proctortopf 5.2 Probeneinbau 5.3 Dichte mit Setzungsmessung 5.4 Dichte bei definiertem Volumen 5.5 Wasserersatz-Verfahren 5.6 Gipsersatz-Verfahren 5.7 Zusammenfassung und Fazit 6 Dichtebestimmung mittels 3D-Scanner 6.1 3D-Scanner „Artec Leo“ 6.1.1 Funktionsweise und Genauigkeiten 6.2 Neue Möglichkeit zur Volumenbestimmung 7 Versuchsstand 7.1 Entwickelte Gegenstände zur Versuchsdurchführung 7.2 Probeneinbau 7.3 Verdichtung mittels Vibrationsverdichter 7.4 Zusammenfassung und Fazit 8 Auswertung 8.1 Vergleich der herkömmlichen Dichtebestimmungsverfahren 8.2 Vergleich des Dichtebestimmungsverfahrens mittels 3D-Scanner 8.3 Ergebnisse aus den Versuchen am Versuchsstand 8.4 Zusammenfassung und Fazit 9 Ergebnisbeurteilung und Ausblick

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