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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.
81

Search for H -] bb̄ in association with a tt̄ pair in proton proton collisions at s=14 TeV

Schmidt, Alexander. January 2007 (has links)
University, Diss., 2006--Karlsruhe.
82

A comparison of seafloor sonar classification methods through the use of error matrices and 3 dimensional GIS visualization : a multibeam sonar investigation of Nehalem Bank, Oregon /

Lanier, Andrew S. January 1900 (has links)
Thesis (M.S.)--Oregon State University, 2007. / Printout. Includes bibliographical references (leaves 101-106). Also available on the World Wide Web.
83

Temporal and spatial patterns of modern shelf sedimentation in the Adriatic Sea /

Palinkas, Cynthia. January 2005 (has links)
Thesis (Ph. D.)--University of Washington, 2005. / Vita. Includes bibliographical references (leaves 130-139).
84

Algorithm for computation of the acoustic plane-wave reflection coefficient of the ocean bottom /

Martinez, David Richard. January 1979 (has links)
Thesis (Elec.E)--M.I.T., Dept. of Electrical Engineering and Computer Science, 1979. / Supervised by Alan V. Oppenheim and George V. Frisk. Bibliography: leaves 132-133.
85

B-Identifikation im Level-2-Trigger des ATLAS-Experiments

Kootz, Andreas. January 2005 (has links) (PDF)
Wuppertal, Univ., Diss., 2005.
86

A study of the velocity structure in a marine boundary layer : instrumentation and observations /

Tochko, John Steven. January 1978 (has links)
Thesis--Massachusetts Institute of Technology and the Woods Hole Oceanographic Institution. / Includes bibliographical references (p. 181-186).
87

Seabed classification from acoustic echosounder returns

Caughey, David Arthur 01 August 2018 (has links)
Efforts to extract information regarding the surficial composition of the ocean bottom have increased in the last decade as increases in the availability of computing power have corresponded with advances in signal processing techniques. The ability to extract information from acoustic echosounders is especially desirable due to the relatively low cost and ease of deployment of such systems. Products already exist for the acquisition and logging of echosounder returns. An acoustic return is comprised of the incoherent backscatter from individual scatterers within the annulus of insonification that occurs when a spherically-spreading transmit pulse intersects with the ocean floor. The return is a convolution of the source ping, and the impulse response modeled by the backscatter profile. Most echosounders, generate an envelope of the received signal. The bottom impulse response undergoes a dilation linear with depth due to simple geometry which can be corrected with time-scale normalization. Under certain circumstances it may be necessary to deconvolve the source ping from the envelope of the return prior to time-scale normalization. It is shown that this can be done by modelling the envelope generation function with a finite sum discrete convolution and the Hilbert transform of the source signal. A second-order Volterra kernel can be derived using a standard predictor network with constrained optimization. Other factors which contribute to the quality of the return include off-vertical transducer angles which in fact improve the classification by eliminating the nulls that occur in the bottom impulse response due to transducer beam pattern. Spatial averaging can have the effect of beam widening if the transducer angle varies. Simple feature extraction algorithms are shown to be moderately effective in providing separability. The computational cost of combining the resulting feature sets can be reduced if the individual feature sets are scaled appropriately, reduced and then combined, prior to a reduction to the final dimensionality. The resulting feature space axes contain contributions from both the principal axes of the individual feature sets, as well as cross-algorithmic terms. Blind clustering of the data is provided through a two-step modification of the K-means algorithm. The first step generalizes it to use arbitrary classification metrics, and the second embeds this generalized kernel within a second kernel which modifies the covariance. The resulting K-stats kernel is very robust when successively applied to a growing number of clusters. / Graduate
88

Materiais híbridos formados por nanofilmes moleculares depositados sobre nanofilmes metálicos produzidos por processo bottom-up em substratos vítreos para uso como parte ativa de nanodispositivos

Schneider, Ricardo 31 January 2008 (has links)
Made available in DSpace on 2014-06-12T22:58:12Z (GMT). No. of bitstreams: 2 arquivo4277_1.pdf: 4341020 bytes, checksum: 14c9ce1c7a9f4c1c01f64ebee2dd8876 (MD5) license.txt: 1748 bytes, checksum: 8a4605be74aa9ea9d79846c1fba20a33 (MD5) Previous issue date: 2008 / No presente trabalho, foi desenvolvido e caracterizado um sistema híbrido formado pela evaporação térmica de um nanofilme molecular de complexo de terra rara sobre um filme fino metálico, obtido por um processo bottom-up. Para a produção do novo híbrido, o complexo fotônico Eu(btfa)3bipy foi depositado sobre um substrato recoberto por um filme de prata nanoestruturado formado pela redução térmica de íons de prata seguido do crescimento e migração de nanopartículas de prata para a superfície do material vítreo. A luminescência do complexo de terra rara sobre o substrato vítreo foi monitorada em função do tempo de tratamento na temperatura de transição vítrea (Tg), e do crescimento do nanofilme autoformado, este, por sua vez, monitorado por microscopia de força atômica (AFM). Amostras de dois sistemas GAPAgF e GAPAgO foram obtidas pela fusão dos materiais de partida em um forno resistivo, seguido por um tratamento térmico próximo da Tg para produzir um filme de prata nanoestruturado na superfície das amostras, apresentando uma aparência metálica. O novo substrato vítreo ativo GAPAgO possui uma enorme velocidade de crescimento do nanofilme se comparada com a cinética de crescimento do vidro ativo GAPAgF, previamente estudado. O crescimento das nanopartículas foi monitorado por AFM em ambos os sistemas, em função do tempo de tratamento térmico, apresentando o crescimento de nanoestruturas de prata com 100 nm somente em dois minutos de tratamento térmico. A energia de ativação E relacionada com cristalização, e o fator de freqüência υ foi calculado para êtsr composições do sistema GAPAgO. O resultado indica uma instabilidade deste vidro se relacionado com o sistema GAPAgF previamente estudado. A morfologia da superfície foi avaliada em função da atmosfera durante o tratamento térmico. O sistema GAPAgO apresentou uma geometria preferencial de crescimento do nanofilme na superfície do vidro. Medidas de fluorescência do íon Eu3+ no complexo Eu(btfa)3 Palavras chave: Nanopartículas de prata, Plásmons, processo bottom up. bipy foram analisadas como uma função do tempo de tratamento, mostrando um melhor aumento da luminescência em amostras com superfícies mais rugosas. As propriedades fotônicas das amostras foram analisadas, e os sistemas foram caracterizados por DRX, AFM e XPS. O objetivo final deste trabalho é de usar esses novos materiais, como substratos ativos para nanodispositivos
89

Discretionary thrift at the bottom of the pyramid

Nkosi, John Henry 29 July 2012 (has links)
The purpose of this research is to investigate the concept of discretionary thrift amongst low income consumers. Flatters and Willmott (2009) identified discretionary thrift as an advancing trend amongst affluent developed nation consumers. These consumers temper their spending habits depending on product or occasion; there are certain products for which consumers are willing to pay a premium (behaviour associated with materialism) and there are others that consumers are looking to save money on (behaviour associated with frugality). Thrift for low income consumers, especially in emerging market settings, is not considered discretionary; rather, it is portrayed as ‘necessary’ to ensure survival. This study followed a descriptive, quantitative design and surveyed 154 individuals considered to be at the bottom of South Africa’s income pyramid. There is sufficient evidence from this research to support the proposition of discretionary thrift amongst low income consumers. Low income consumers were found to save money by paying as little as possible (behaviour associated with frugality) for fast moving consumer goods with low functional and status risk and were found to willingly pay the required premium (behaviour associated with materialism) for socially visible aspirational brands of clothing and fast moving consumer goods. The level of frugality and materialism expressed with respect to these products was not influenced by age or level of education. However, the level of frugality expressed with respect to these products was affected by an individual’s gross and disposable income. / Dissertation (MBA)--University of Pretoria, 2012. / Gordon Institute of Business Science (GIBS) / unrestricted
90

The Floor of the Mediterranean Sea

Ryan, William B. F. January 1969 (has links)
The bathymetry, magnetic anomalies, gravity anomalies and sediment layer is presented to support a young Western Mediterranean no older than 25 million years and an Eastern Mediterranean as old as 200 million years. A buried salt layer is detected in seismic reflection profiles lying below a sediment cover whose base is 4 to 5 million years in age. The seafloor in the eastern Mediterranean is being actively deformed by compressional folding and thrusting beneath the Mediterranean Ridge. The Western Mediterranean opened by rifting and is floored by oceanic crust.

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