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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.
471

A Novel Active Contour Framework. Multi-component Level Set Evolution under Topology Control

Segonne, Florent, Pons, Jean-Philippe, Fischl, Bruce, Grimson, Eric 01 June 2005 (has links)
We present a novel framework to exert a topology control over a level set evolution. Level set methods offer several advantages over parametric active contours, in particular automated topological changes. In some applications, where some a priori knowledge of the target topology is available, topological changes may not be desirable. A method, based on the concept of simple point borrowed from digital topology, was recently proposed to achieve a strict topology preservation during a level set evolution. However, topologically constrained evolutions often generate topological barriers that lead to large geometric inconsistencies. We introduce a topologically controlled level set framework that greatly alleviates this problem. Unlike existing work, our method allows connected components to merge, split or vanish under some specific conditions that ensure that no topological defects are generated. We demonstrate the strength of our method on a wide range of numerical experiments.
472

Control of pulmonary surfactant secretion : an evolutionary perspective

Wood, Philip (Philip Gregory), 1967- January 1999 (has links) (PDF)
Bibliography: leaves 209-254. Attempts to construct an evolutionary overview of the regulation of surfactant secretion among the vertebrates. A detailed whole animal and in vitro study of the factors that control surfactant secretion and function in the central Australian agamid lizard Pogona vitticeps was undertaken. Type II pneumocytes were also isolated and cultured from Australian lungfish, North American bullfrogs and fat-tailed dunnarts.
473

Manual and automatic control of an active suspension for high-speed off-road vehicles /

Efatpenah, Keyanoush, January 1999 (has links)
Thesis (Ph. D.)--University of Texas at Austin, 1999. / Vita. Includes bibliographical references (leaves 459-466). Available also in a digital version from Dissertation Abstracts.
474

A near-infrared view of luminous quasars : black hole masses, outflows and hot dust

Coatman, Liam January 2017 (has links)
Supermassive black holes (BHs) and their host-galaxies are thought to evolve in tandem, with the energy output from the rapidly-accreting BH regulating star formation and the growth of the BH itself. The goal of better understanding this process has led to much work focussing on the properties of quasars at high redshifts, $z\gtrsim 2$, when cosmic star formation and BH accretion both peaked. At these redshifts, however, ground-based statistical studies of the quasar population generally have no access to the rest-frame optical spectral region, which is needed to measure H$\beta$-based BH masses and narrow line region outflow properties. The cornerstone of this thesis has been a new near-infrared spectroscopic catalogue providing rest-frame optical data on 434 luminous quasars at redshifts $1.5 \lesssim z \lesssim 4$. At high redshift, $z \gtrsim 2$, quasar BH masses are derived using the velocity-width of the CIV broad emission-line, based on the assumption that the observed velocity-widths arise from virial-induced motions. However, CIV exhibits significant asymmetric structure which suggests that the associated gas is not tracing virial motions. By combining near-infrared spectroscopic data (covering the hydrogen Balmer lines) with optical spectroscopy from SDSS (covering CIV), we have quantified the bias in CIV BH masses as a function of the CIV blueshift. CIV BH masses are shown to be over-estimated by almost an order of magnitude at the most extreme blueshifts. Using the monotonically increasing relationship between the CIV blueshift and the mass ratio BH(CIV)/BH(H$\alpha$) we derive an empirical correction to all CIV BH-masses. The correction depends only on the CIV line properties and therefore enables the derivation of un-biased virial BH mass estimates for the majority of high-luminosity, high-redshift, spectroscopically confirmed quasars. Quasars driving powerful outflows over galactic scales is a central tenet of galaxy evolution models involving 'quasar feedback' and significant resources have been devoted to searching for observational evidence of this phenomenon. We have used [OIII] emission to probe ionised gas extended over kilo-parsec scales in luminous $z\gtrsim2$ quasars. Broad [OIII] velocity-widths and asymmetric structure indicate that strong outflows are prevalent in this population. We estimate the kinetic power of the outflows to be up to a few percent of the quasar bolometric luminosity, which is similar to the efficiencies required in recent quasar-feedback models. [OIII] emission is very weak in quasars with large CIV blueshifts, suggesting that quasar-driven winds are capable of sweeping away gas extended over kilo-parsec scales in the host galaxies. Using data from a number of recent wide-field photometric surveys, we have built a parametric SED model that is able to reproduce the median optical to infrared colours of tens of thousands of AGN at redshifts $1 < z < 3$. In individual objects, we find significant variation in the near-infrared SED, which is dominated by emission from hot dust. We find that the hot dust abundance is strongly correlated with the strength of outflows in the quasar broad line region, suggesting that the hot dust may be in a wind emerging from the outer edges of the accretion disc.
475

Encouraging public transportation to increase active commutation in Manhattan, KS

Singh, Annapurna January 1900 (has links)
Master of Regional and Community Planning / Department of Landscape Architecture/Regional and Community Planning / John W. Keller / Transportation is a means of commutation for goods and people and is also an indicator of socioeconomic status of a community. Recently, there has been much debate and research on the impact of transportation on the health care of a community. Lately, it has been proved that increased dependence of people on cars has led to lack of exercise in their daily life. This lack of exercise has been identified as the root cause of severe cardiovascular ailments like high blood pressure, hypertension and even several types of cancers. As a solution, many planners are now proposing public transit (which forces people to walk to and from transit stations) and other active modes of transport like bikes etc. as alternative transportation options to improve community health and reduce dependence on cars. These options not only help people incorporate exercise in their daily life but a reduction in car usage reduces the demand for parking spaces, traffic congestions, carbon footprints of communities and is fuel efficient. This project based in the City of Manhattan is aimed at suggesting measures to enhance the use of public transit among students at Kansas State University to help incorporate more exercise in their daily lives. The project encompassed an observational study to identify the options currently available for transit and factors which affected transit ridership in the city. The observational study was followed by discussion with a focus group to draw views and opinions. These opinions and views were included in a questionnaire for an online survey to identify areas or measures which were most likely to enhance transit ridership positively and cost effectively. This project provides suggestive guidelines regarding students’ opinion about transit in Manhattan. These suggestions could be used to guide policies and strategies for enhancing transit ridership in the city.
476

Aktivně a pasivně řízené akciové otevřené podílové fondy

Klimešová, Iveta January 2011 (has links)
No description available.
477

Statistická a finanční analýza společnosti VELOX-WERK s.r.o. Hranice

Matějíčná, Iva January 2011 (has links)
No description available.
478

Representing Organizational Structures in Enterprise Architecture: an Ontology-based Approach

PEREIRA, D. C. 27 February 2015 (has links)
Made available in DSpace on 2016-08-29T15:33:21Z (GMT). No. of bitstreams: 1 tese_8607_MSC Thesis - Diorbert - FINAL(1).pdf: 3922223 bytes, checksum: b3e393525cb2dc99d26745cd7397ee7b (MD5) Previous issue date: 2015-02-27 / Enterprise Architecture (EA) promotes the establishment of a holistic view of the structure and way of working of an organization. One of the aspects covered in EA is associated with the organizations active structure, which concerns who undertakes organizational activities. Several approaches have been proposed in order to provide a means for representing enterprise architecture, among which ARIS, RM-ODP, UPDM and ArchiMate. Despite the acceptance by the community, existing approaches focus on different purposes, have limitations on their conceptual scopes and some have no real world semantics well-defined. Besides modeling approaches, many ontology approaches have been proposed in order to describe the active structure domain, including the ontologies in the SUPER Project, TOVE, Enterprise Ontology and W3C Org Ontology. Although specified for semantic grounding and meaning negotiation, some of proposed approaches have specific purposes and limited coverage. In addition, some of them are not defined using formal languages and others are specified using languages without well-defined semantics. This work presents a well-founded reference ontology for the organizational domain. The organizational reference ontology presented covers the basic aspects discussed in the organizational literature, such as division of labor, social relations and classification of structuring units. Further, it also encompasses the organizational aspects defined in existing approaches, both modeling and ontology approaches. The resulting ontology is specified in OntoUML and extends the social concepts of UFO-C.
479

Public Mass Shootings Impact on the Public’s Firearm Carrying Habits: Evidence of a Moral Panic

January 2018 (has links)
abstract: Public mass shootings occur at a rate in the U.S. that is higher than any other developed country. These event initiate wide spread media attention. The media attention these events achieve have shown to impact the public behavior (e.g., increased firearm sales). However, the impact public mass shootings have on firearm storage and carry habits of the public is not well understood. Using data collected from the Transportation Security Administration, this study examines how mass shootings have led to moral panics occurring within the U.S. through the examination of the firearm carrying habits among the population immediately following mass shootings. The results indicate that loaded firearms with rounds in the chamber detected by the TSA have significantly increased since 2012. Further, firearms detected immediately following a public mass shooting had a higher proportion of firearms loaded with a round in the chamber relative to 7 days prior to the shooting. Moreover, the increase in proportions of firearms found loaded with a round in the chamber exponentially decays as days past the initial shooting, these events occur at a higher rate than the decay rate can normalize these occurrences. I conclude that in the wake of these shootings a moral panic ensues that is partially responsible for the change in the general public’s arming configuration habits. Further research is needed in to determine the impact on crime, and public health related issues due to this change in the public’s firearm carrying habits. / Dissertation/Thesis / Masters Thesis Criminology and Criminal Justice 2018
480

CANDELS: Elevated Black Hole Growth in the Progenitors of Compact Quiescent Galaxies at z ∼ 2

Kocevski, Dale D., Barro, Guillermo, Faber, S. M., Dekel, Avishai, Somerville, Rachel S., Young, Joshua A., Williams, Christina C., McIntosh, Daniel H., Georgakakis, Antonis, Hasinger, Guenther, Nandra, Kirpal, Civano, Francesca, Alexander, David M., Almaini, Omar, Conselice, Christopher J., Donley, Jennifer L., Ferguson, Harry C., Giavalisco, Mauro, Grogin, Norman A., Hathi, Nimish, Hawkins, Matthew, Koekemoer, Anton M., Koo, David C., McGrath, Elizabeth J., Mobasher, Bahram, Pérez González, Pablo G., Pforr, Janine, Primack, Joel R., Santini, Paola, Stefanon, Mauro, Trump, Jonathan R., van der Wel, Arjen, Wuyts, Stijn, Yan, Haojing 07 September 2017 (has links)
We examine the fraction of massive (M-* > 10(10)M(circle dot)) compact star-forming galaxies (cSFGs) that host an active galactic nucleus (AGN) at z similar to 2. These cSFGs are likely the direct progenitors of the compact quiescent galaxies observed at this epoch, which are the first population of passive galaxies to appear in large numbers in the early Universe. We identify cSFGs that host an AGN using a combination of Hubble WFC3 imaging and Chandra X-ray observations in four fields: the Chandra Deep Fields, the Extended Groth Strip, and the UKIDSS Ultra Deep Survey field. We find that 39.2(-3.6)(+3.9)% (65/166) of cSFGs at 1.4 < z < 3.0 host an X-ray detected AGN. This fraction is 3.2 times higher than the incidence of AGN in extended star-forming galaxies with similar masses at these redshifts. This difference is significant at the 6.2 sigma level. Our results are consistent with models in which cSFGs are formed through a dissipative contraction that triggers a compact starburst and concurrent growth of the central black hole. We also discuss our findings in the context of cosmological galaxy evolution simulations that require feedback energy to rapidly quench cSFGs. We show that the AGN fraction peaks precisely where energy injection is needed to reproduce the decline in the number density of cSFGs with redshift. Our results suggest that the first abundant population of massive quenched galaxies emerged directly following a phase of elevated supermassive black hole growth and further hints at a possible connection between AGN and the rapid quenching of star formation in these galaxies.

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