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1
Rindberg, Jonas. "Kartdataimport för fälttillämpning." Thesis, Högskolan Dalarna, Datateknik, 2006. http://urn.kb.se/resolve?urn=urn:nbn:se:du-2404.
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I dagsläget kan WM-datas Fältmodul i deras MoveITS-system inte hantera kartdata i andra format än Shape. Fältmodulen är en TabletPC som kör operativsystemet Windows XP. Den kan användas för att redigera viss geografisk information som exempelvis skyltpositioner. Fältmodulen används av Stockholms Tekniska kontor för inventering av skyltstolpar.Stockholms Tekniska kontor ska börja leverera sina kartor i GML (Geography Markup Language). Men eftersom WM-datas Fältmodul inte klarar av det formatet skulle det här examensarbetet gå ut på att ta fram komponenter för hantering av det. Då det under examensarbetets gång har varit svårt att få tag i information runt GML har istället en större fokus blivit lagd på MIF (MapInfo Interchange Format). Eftersom det finns andra kommuner som använder MIF finns det intresse från WM-data att det tas fram komponenter även för detta format.Ett stort antal klasser har utvecklats för hantering av MIF-filer. Dessa klasser är helt utvecklade i C# och har gjorts under examensarbetets gång utifrån de specifikationer som finns för formatet från företaget MapInfo. För GML har det tagits fram information som kan ligga till grund för utveckling av komponenter för hantering av det formatet.
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Dias, Ricardo Ferreira. "O espaço das sequências mid somáveis e operadores mid somantes." Universidade Federal da Paraíba, 2017. http://tede.biblioteca.ufpb.br:8080/handle/tede/9836.
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Previous issue date: 2017-08-18<br>Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES<br>The main goal of this work is to study a new sequence space introduced in 2014 by
Karn and Sinha, namely the space of mid p-summable sequences. More speci cally, we
will study a recent work by G. Botelho and J.R. Campos, which deepens the seminal
study of this space and presents new classes of operators involving the new space and
the classical sequence spaces of absolutely and weakly p-summable sequences, called
absolutely mid p-summing and weakly mid p-summing operators. From this, we study
a new factorization theorem, involving these new classes of operators, for the absolutely
p-summing operators.<br>O principal objetivo desta dissertação é estudar um novo espaço de sequências introduzido
por Karn e Sinha em 2014, a saber, o espaçoo das sequências mid p-somáveis.
Mais especi camente, estudaremos um recente trabalho de G. Botelho e J. R. Campos
que aprofunda o estudo seminal do espa co e apresenta novas classes de operadores
envolvendo este novo espa co e os espa cos cl assicos de sequ^encias absolutamente e
fracamente p-somáveis, denominados operadores absolutamente mid p-somantes e operadores
fracamente mid p-somantes. A partir disto, estudamos um novo teorema de
fatoração, envolvendo estas novas classes de operadores, para os operadores absolutamente
p-somantes.
mid p-somáveis; Operadores absolutamente e fracamente mid p-somantes.
3
Schuller, Peter. "Calibration of MIDI, the mid-infrared interferometer for the VLTI." [S.l.] : [s.n.], 2002. http://deposit.ddb.de/cgi-bin/dokserv?idn=965507084.
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JUNIOR, ADY CAMBRAIA. "ENVELOPE OF MID-PLANES." PONTIFÍCIA UNIVERSIDADE CATÓLICA DO RIO DE JANEIRO, 2015. http://www.maxwell.vrac.puc-rio.br/Busca_etds.php?strSecao=resultado&nrSeq=25484@1.
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PONTIFÍCIA UNIVERSIDADE CATÓLICA DO RIO DE JANEIRO<br>COORDENAÇÃO DE APERFEIÇOAMENTO DO PESSOAL DE ENSINO SUPERIOR<br>PROGRAMA DE SUPORTE À PÓS-GRADUAÇÃO DE INSTS. DE ENSINO<br>O Envelope de Retas Médias - ERM consiste da união de três conjuntos invariantes afins: o Affine Envelope Symmetry Set - AESS; o Mid-Parallel Tangents Locus - MPTL; e a Evoluta Afim - EA. O ERM de curvas
planas convexas é um assunto que tem sido muito explorado. Porém, não existe na literatura nenhum estudo do ERM para superfícies. Por isso, o objetivo principal desta tese é generalizar o ERM de curvas convexas para superfícies convexas. Para tanto, dividimos a tese em duas partes. A primeira consiste de uma revisão sobre a geometria afim de curvas planas e do estudo do ERM com uma nova abordagem. Na segunda parte realizamos uma breve introdução da geometria afim de hipersuperfícies e a generalização do ERM. Na generalização do ERM, trabalhamos com superfícies, definimos os planos médios e estudamos o que denominamos Envelope de Planos Médios -EPM. Provamos que, o EPM assim como o ERM, é formado por três conjuntos invariantes afins: a Superfície de Centros de 3 mais 3-Cônicas - SC3C; o Mid-Parallel Tangents Surface -MPTS; e a Evoluta de Curvas Médias - ECM.<br>The Envelope of Mid-Lines - EML consists of the union of three affine
invariant sets: the Affine Envelope Symmetry Set - AESS; the Mid-Parallel
Tangents Locus - MPTL; and the Affine Evolute. The EML of convex
planar curves is a subject that has been very explored. However, there is
no study in the literature of the EML for surfaces. Therefore, the main
objective of this thesis is to generalize the EML of convex curves to convex
surfaces. We divide the writing into two parts. The first part consists of a
study of the EML with a new approach. In the second part we consider the
EML for surfaces, that we call Envelope of Mid-Planes - EMP. We prove
that, the EMP, like the EML, is formed by three affine invariant sets: the
Centers of 3 plus 3-Conics Surface - C3CS; the Mid-Parallel Tangents Surface
-MPTS; and the Medial Curves Evolute - MCE.
5
Sorenson, Peter David, and peter sorenson@rmit edu au. "Signs of mid-life: images from the contemporary Australian mid-life male psyche." RMIT University. Applied Communication, 2005. http://adt.lib.rmit.edu.au/adt/public/adt-VIT20060428.113457.
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This research project investigates images from the contemporary Australian mid-life psyche, exploring the contribution to individual transformation made through the creation of, and reflective engagement with, personal imagery. Asking the question: 'What do contemporary Australian mid-life males consider to be a rich and sustaining inner life?' This project documents the visual images, descriptions, and reflections of a group of five participants, discussing the individuals' experiences of aesthetic self-inquiry with reference to divergent theories of psychology, art therapy and philosophy of aesthetics.
6
Thompson, Timothy David. "The take-up of farm woodland grants in Mid-Wales." Thesis, University of Wales Trinity Saint David, 1996. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.683133.
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Law, Tze-leung. "An examination of the enironmental impacts of the hillside escalator in Mid-Levels /." Hong Kong : University of Hong Kong, 1995. http://sunzi.lib.hku.hk/hkuto/record.jsp?B14803434.
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Lin, Shu-fen. "'Democratization' in Taiwan (mid-1980s - mid-1990s) revisited : in pursuit of a radical democracy." Thesis, University of Essex, 2000. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.410323.
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Dusunur, Doga. "Thermal structure of Mid-Ocean Ridges (Lucky Strike, Mid-Atlantic Ridge) and magma chambers." Paris, Institut de physique du globe, 2008. http://www.theses.fr/2008GLOB0002.
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Modéliser la structure thermique de la croûte océanique est une étape importante pour comprendre la création de la croûte océanique qui couvre les deux tiers de la surface de notre planète. La production magmatique à l'axe de la dorsale et le refroidissement de la lithosphère océanique en fonction du temps et de l'espace sont des facteurs clés pour comprendre la création de la croûte océanique, qui est déterminée en premier lieu par la structure thermique des dorsales. Les modèles thermiques classiques ne prédisent pas l'existence de chambres magmatiques stationnaires le long des dorsales qui ont un taux d'expansion inférieur à 30 mm/an. L'identification par imagerie sismique d'une chambre magmatique sous le volcan et le champ hydrothermal de Lucky Strike sur la dorsale médio-Atlantique représente une opportunité unique d'étudier la structure thermique des dorsales lentes. Nous présentons ici conjointement des données microsismiques et une modélisation thermique qui nous permettent d'éclaircir la nature des chambres magmatiques éphémères aux dorsales lentes, de contraindre les échelles de temps associées aux changements dans l'alimentation magmatique et les paramètres nécessaires à l'existence d'une chambre magmatique, et nous renseignent sur les différents mécanismes qui peuvent conduire au refroidissement et à la disparition d'une chambre magmatique. Les résultats de l'analyse microsismique, de la modélisation thermique et les contraintes temporelles dérivées des contraintes géologiques suggèrent qu'il existe un apport focalisé au centre du segment, et ce de façon régulière, et que cet apport est maintenu sur des périodes de temps étendu, pouvant conduire à une chambre magmatique durable. Cette thèse, tout en traitant des processus actifs au segment Lucky Strike, fournit un modèle plus général pour comprendre et étudier d'autres segments de dorsales lentes, et comprendre comment se forme la croûte océanique le long de ces segments<br>Modeling the thermal state of the oceanic crust is an important task to understand the construction of oceanic crust which covers two thirds of the surface of our planet. The interplays among magma delivery to the axis and cooling of the oceanic lithosphere as a function of both space and time are key factors to understand the creation of the oceanic crust, which is primarily determined by the overall thermal structure of mid-ocean ridges. Classical thermal models do not predict steady state axial magma chambers (AMCs) along mid-ocean ridges at spreading rates less than 30 mm/year. The identification and seismic imaging of an axial magma chamber underlying the Lucky Strike central volcano and hydrothermal field at the Mid-Atlantic Ridge provides a unique opportunity to study the thermal structure of slow spreading ridges. Here we present coupled microseismic data and thermal modeling to provide insight on the nature of ephemeral magma chambers at slow-spreading ridges, to constrain the timescales associated with changes in melt supply and the parameters that can create them, and to shed light on the different mechanisms that can result on the cooling and disappearance of these structures. Both the coupled microseismic and thermal modeling results, and the time-constraints derived from the geological constraints put forward, suggest that focused melt supply to the segment center is required regularly, and that this supply is maintained over extended periods of time, that can lead to a durable magma chamber. This thesis, while focusing on the processes occurring at the Lucky Strike, provide a more general template to both understand and study other slow-spreading ridge segments, and to gain insight on how the oceanic crust is formed along them
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Shankar, Raji. "Mid-Infrared Photonics in Silicon." Thesis, Harvard University, 2013. http://dissertations.umi.com/gsas.harvard:10988.
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The mid-infrared wavelength region (2-20 µm) is of great utility for a number of applications, including chemical bond spectroscopy, trace gas sensing, and medical diagnostics. Despite this wealth of applications, the on-chip mid-IR photonics platform needed to access them is relatively undeveloped. Silicon is an attractive material of choice for the mid-IR, as it exhibits low loss through much of the mid-IR. Using silicon allows us to take advantage of well-developed fabrication techniques and CMOS compatibility, making the realization of on-chip integrated mid-IR devices more realistic. The mid-IR wavelengths also afford the opportunity to exploit Si's high third-order optical nonlinearity for nonlinear frequency generation applications. In this work, we present a Si-based platform for mid-IR photonics, with a special focus on micro-resonators for strong on-chip light confinement in the 4-5 μm range. Additionally, we develop experimental optical characterization techniques to overcome the inherent difficulties of working in this wavelength regime. First, we demonstrate the design, fabrication, and characterization of photonic crystal cavities in a silicon membrane platform, operational at 4.4 μm (Chapter 2). By transferring the technique known as resonant scattering to the mid-IR, we measure quality (Q) factors of up to 13,600 in these photonic crystal cavities. We also develop a technique known as scanning resonant scattering microscopy to image our cavity modes and optimize alignment to our devices. Next, we demonstrate the electro-optic tuning of these mid-IR Si photonic crystal cavities using gated graphene (Chapter 3). We demonstrate a tuning of about 4 nm, and demonstrate the principle of on-chip mid-IR modulation using these devices. We then investigate the phenomenon of optical bistability seen in our photonic crystal cavities (Chapter 4). We discover that our bistability is thermal in origin and use post-processing techniques to mitigate bistability and increase Q-factors. We then demonstrate the design, fabrication, and characterization grating-coupled ring resonators in a silicon-on-sapphire (SOS) platform at 4.4 μm, achieving intrinsic Q-factors as high as 278,000 in these devices (Chapter 5). Finally, we provide a quantitative analysis of the potential of our SOS devices for nonlinear frequency generation and describe ongoing experiments in this regard (Chapter 6).<br>Engineering and Applied Sciences
11
Scheffler, Thomas. "Chancen und Möglichkeiten des Duroplast für MID-Anwendungen." Universitätsbibliothek Chemnitz, 2016. http://nbn-resolving.de/urn:nbn:de:bsz:ch1-qucosa-198598.
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Cora, Elisa. "Analyses structurales et fonctionnelles de la voie des ARNpi." Thesis, Grenoble, 2014. http://www.theses.fr/2014GRENV002.
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Les ARNs interagissant avec Piwi (ARNpi ou piRNA en anglais pour Piwi-interacting RNAs) interagissent avec les protéines de la branche PIWI de la famille des Argonautes. Ils participent à la répression des transposons dans la ligne germinale. Les ARNpi sont produits à partir de deux mécanismes: la biogenèse primaire et le cycle d'amplification Ping-Pong. Plusieurs questions fondamentales sur la biogenèse et la fonction des piRNAs sont encore ouvertes. Le travail de ce mémoire est concentré sur deux caractéristiques au niveau de la séquence dans les populations des ARNpi, le U1-biais et le biais de brin, dont les origines restent mystérieuses. Nos analyses ont révélé de nouvelles fonctions au protéines Piwi, dont les domaines MID et PIWI jouent un rôle essentiel dans la définition des deux biais. La structure cristalline du domaine MID de MIWI montre que l'uridine peut être favorisé comme premier nucléotide au niveau de l'extrémité 5' des ARNpi. De la même manière, nos résultats obtenus grâce aux études in vivo des protéines Piwi de Bombyx mori démontrent que le module MID-PIWI est essentiel pour déterminer le bias de brin des ARNpi s'associant avec les protéines Piwi. De plus, nous avons confirmé le rôle de la méthylation de la région N-terminale des protéines Piwi pour leur localisation dans la cellule. Ensemble, ces résultats offrent de nouveaux détails pour la compréhension de la biogenèse des ARNpi.Les protéines Piwi ne sont pas les seuls composants dans la voie des ARNpi. Des tests génétiques ainsi que des analyses biochimiques ont identifié plusieurs éléments impliqués dans la voie des ARNpi, cependant leurs fonctions restent obscures. J'ai étudié la protéine Vreteno, contenant des domaines Tudor, qui est impliquée dans le processus de biogenèse primaire des ARNpi. En utilisant la lignée cellulaire BmN4, nous avons identifié in vivo un complexe contenant Vreteno, des longues molécules d'ARN antisens, pouvant representer les précurseurs des ARNpi associés avec Siwi, ainsi que d'autres composants de la voie ARNpi, comme Ago3, BmTdrd12 et Spindle-E. De plus amples analyses sont nécessaires pour comprendre les fonctions de Vreteno dans la voie des ARNpi.Enfin, nous avons également étudié le rôle de l'hélicase à ARN Vasa dans la voie des piRNAs. Nos résultats démontrent que Vasa assemble un complexe régulé par l'ATP sur le ARN messager des transposons, afin de produire de nouveaux ARNpi secondaires avec orientation sens. En étudiant les différentes étapes de la voie des ARNpi, nos analyses ont fourni des informations importantes pour la compréhension de la biogénèse des ARNpi<br>Piwi-interacting RNAs (piRNAs) associate to members of the PIWI clade of Argonaute proteins and are responsible for silencing of transposable elements in animal germ lines. piRNAs are produced through two biogenesis pathways, known as primary processing and Ping-Pong amplification cycle. There are many fundamental questions regarding piRNA biogenesis and function that are unsolved. In this thesis I have been focusing on the presence of two sequences features in piRNA populations, the U1-bias and the strand-bias, whose determination is not understood. Our analyses have revealed new features of the Piwi proteins, whose MID and PIWI domains play an essential role in the definition of both piRNA biases. The crystal structure of the MID domain of MIWI shows that uridine can be favored as the first nucleotide at the 5' end, while our in vivo results on Bombyx mori Piwi proteins demonstrate that the MID-PIWI module is essential to determine the strand bias of piRNAs that associate to the Piwi protein. Moreover we have confirmed the role of the methylation status of the N-terminus of Piwi protein for determining their localization. Altogether these findings provide new insights in the understanding of piRNA biogenesis.Piwi proteins are not the only components acting in the piRNA pathway. Genetic screenings and biochemical analyses have identified several other factors, which have been involved in the piRNA pathway, but whose functions remain elusive. I have focused on the Tudor domain-containing protein Vreteno, which has been involved in the primary biogenesis pathway. Using BmN4 cells, we have identified an in vivo complex of Vreteno, containing long antisense RNA molecules, which might represent the precursor of Siwi-piRNAs, and other piRNA known factors, like Ago3, BmTdrd12 and Spindle-E. Further analyses are required for the understanding of Vreteno functions in the piRNA pathway.Finally, we have also investigated the role of the RNA helicase Vasa in the piRNA pathway. Our results show that Vasa assembles an ATP-gated Ping-pong complex on transposon mRNAs to generate new sense-oriented secondary piRNAs. By looking at different step in the piRNA pathway our analyses have provided important insights for the understanding of the piRNA biogenesis
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Reid, William David Kenneth. "Trophodynamics on mid-ocean ridges." Thesis, University of Newcastle Upon Tyne, 2012. http://hdl.handle.net/10443/1744.
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The global mid-ocean ridge (MOR) system is ~60 000 km long and accounts for 9% of the seafloor. Deep-sea organisms living on MOR have two potential energy sources; chemosynthesis and the downward flux of photosynthetic organic matter. This study examines the trophodynamics of benthic fauna collected from non-vent sites north and south of the Charlie-Gibb Fracture Zone (CGFZ) on the Mid-Atlantic Ridge (MAR) and hydrothermal vents fields (E2 and E9) on the East Scotia Ridge (ESR) using stable isotopes of carbon (δ13C), nitrogen (δ15N) and sulphur (δ34S). δ13C and δ34S values revealed the MAR benthos was sustained by photosynthetic primary production and no chemosynthetic food source was detected. δ15N values of benthic invertebrates were lower than the surficial sediments at the southern site but this did not occur at the northern site. Benthic invertebrates appeared to comprise a separate food chain to bentho-pelagic fishes and crustaceans but size-based trends in δ13C and δ15N revealed at certain life history stages bentho-pelagic fishes may consume benthic fauna. Size-based trends in δ13C and δ15N trends varied spatially and temporally in some bentho-pelagic fishes, which suggested differences in feeding plasticity among the species. Spatial differences among sites were observed in δ13C, δ15N and δ34S of the ESR vent fauna. These were thought to reflect differences in the vent fluid chemistry, vent derived carbon fixation pathways and incorporation of photosynthetic organic matter into the vent system depending on the species and the magnitude of the difference among sites. Size and sex were important determinants of intra-population variability in stable isotope values of three species of vent fauna but this was not consistent among sites. Abstract ii The present study revealed the importance of undertaking a tri-isotope approach to deep-sea trophic studies in order to elucidate production sources and at different sizes deep-sea organisms can link different trophic pathways.
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Hughes, Margaret. "Shopping potential in Mid Wales." Thesis, University of Wales Trinity Saint David, 1994. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.683000.
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Tran, Ngoc Linh. "Mid-Infrared Intersubband Polaritonic Devices." Thesis, université Paris-Saclay, 2020. http://www.theses.fr/2020UPAST001.
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Les polaritons intersousbandes (ISB) sont le résultat du régime de couplage fort lumière-matière entre les transitions intesousbandes de puits quantiques dopés et un mode photonique en microcavité. En raison de leur nature bosonique, les polaritons ISB peuvent être sujet à une diffusion stimulée par l'état final via différents mécanismes tels que la diffusion polariton-polariton ou la diffusion polariton-phonon. Les polaritons ISB sont très prometteurs dans la perspective du développement d'une nouvelle classe de laser, qui repose sur la diffusion stimulée par l'état final au lieu de l'inversion de population des lasers classiques. Cette thèse est consacrée au développement de dispositifs optoélectroniques (lasers et modulateurs) basés sur les polaritons ISB. À cet égard, nous avons développé une plateforme de cavité métal-métal (MIM) avec une ouverture périodique sur le miroir métallique supérieur, qui peut être utilisée pour réaliser des expériences d'injection électrique et optique dans les polaritons ISB. Nous avons démontré la formation des polaritons ISB et leur immunité à la présence d'un élargissement inhomogène. En outre, nous avons optimisé la largeur de ligne des transitions ISB par une technique de croissance d’épitaxie appelée interruption de croissance. En utilisant ces cavités MIM, nous avons réussi à démontrer la diffusion des polaritons vers un état final via leur interaction avec des phonons optiques longitudinaux (LO) sous injection résonante de lumière cohérente. Nous avons également développé des modulateurs d'amplitude en espace libre, qui reposent sur le changement de réflectance du régime de couplage fort auquel un biais de radiofréquence (RF) est appliqué. Enfin, nous avons montré l'existence d'une nouvelle forme d'état excitonique dans la bande de conduction des puits quantiques dopés. Pour cette démonstration, nous avons profité du fort confinement offert par le résonateur MIM pour lier ensemble les charges répulsives d'une transition ionisante<br>Intersubband (ISB) polaritons are the result of the strong light-matter coupling regime between intersubband transitions in doped quantum wells and a microcavity photonic mode. Owing to their bosonic nature, ISB polaritons can be subject to final state stimulated scattering via different mechanism such as polariton-polariton scattering or polariton-phonon scattering. ISB polaritons hold great promises in view of the development of a novel class of laser, which rely on final state stimulated scattering instead of the population inversion in conventional lasers. This thesis is devoted to the development of optoelectronic devices (lasers and modulators) based on ISB polaritons. In this respect, we have developed a metal-metal (MIM) cavity platform with a periodic opening on the top metallic mirror, which can be employed to perform both electrical and optical injection experiments within ISB polaritons.We have demonstrated the formation of ISB polaritons and their immunity to the presence of inhomogeneous broadening. In addition, we have optimized the linewidth of ISB transitions via an epitaxial growth technique known as growth interruption. Using these MIM cavities, we have successfully demonstrated the evidence of polaritons scattering towards a final state via their interaction with longitudinal optical (LO) phonons under resonant injection of coherent light. We have also developed free-space amplitude modulators, which rely on the change of reflectance of the strong coupling regime to which a radio frequency (RF) bias is applied. Finally, we have shown the existence of a new form of excitonic state within the conduction band of doped Quantum Wells. For this demonstration, we have taken advantage of the strong confinement offered by MIM resonator to bind together the repulsive charges of an ionizing transition.frequency range. In the presented work, we have developed a metal-metal cavity platform with a periodic opening on the top metallic mirror, which can be employed to perform both electrical and optical injection experiments. We have shown the formation of ISB polaritons and we have addressed an issue related to polaritons, i.e., the immunity of ISB polaritons to the presence of inhomogeneous broadening in active regions with high doping. In addition, we have optimized the linewidth of ISB transitions via epitaxial growth techniques such as modulation doping and the growth interruption. Using the metal-metal cavity platform, we have successfully demonstrated the optical pumping experiment into a bright polariton state to reveal the evidence of the polariton scattering towards a final state via interaction with the longitudinal optical (LO) phonon. We have also developed free-space amplitude modulators, which rely on the modulation of the strong coupling regime at a high speed via an applied electric field. Lastly, we have experimentally investigated a new type of the strong coupling regime for bound-to-continuum transitions in quantum well. This finding indicated that the strong light-matter coupling can non-perturbatively modify the excitation nature (ionizing), leading to the formation of polariton modes with the bound state nature
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Flores, Yuri Victorovich. "Mid-infrared quantum cascade lasers." Doctoral thesis, Humboldt-Universität zu Berlin, Mathematisch-Naturwissenschaftliche Fakultät, 2015. http://dx.doi.org/10.18452/17224.
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Quantenkaskadenlaser (QCLs) wurden vor gerade zwanzig Jahren erfunden und haben seitdem stetig im weltweiten Markt der optoelektronischen Bauelemente für den Infrarot an Bedeutung gewonnen. Anwendungsbeispiele für aktuelle und potenzielle Einsatzgebiete von QCLs sind photoakustische Spektroskopie, Umweltüberwachung, Simulation von heißen Körpern, und optische Freiraumdatenübertragung. Rekord optische Leistungen von 14 W und Leistungseffizienzen zwischen 15-35 % wurden bei mittelinfraroten QCLs für Betriebstemperaturen zwischen 80-300 K erreicht. Die weitere Verbesserung dieser Eigenschaften hängt nicht nur von Aspekten wie Wärmemanagement und Chip-Packaging ab, sondern auch von Verbesserungen im Laserdesign zwecks der Reduzierung des Ladungsträgerleckstroms. Dennoch sind die verschiedenen Mechanismen und Komponenten des Leckstroms in Quantenkaskadenlasern leider noch nicht gründlich untersucht worden. Die vorliegende Arbeit liefert a realistische Beschreibung der Ladungsträgertransports in QCLs. Wir beschreiben u.a. Leckströme vom Quantentopf- in höhere Zustände und diskutieren elastische und inelastische Streumechanismen von Ladungsträgern bei mittelinfraroten Quantenkaskadenlasern. Wir illustrieren außerdem die Notwendigkeit zur Berücksichtigung der Elektronentemperatur für eine vollständigere Analyse der Ladungsträgertransporteigenschaften von Quantenkaskadenlasern. Methoden zur experimentellen Ermittlung des temperaturabhängigen Leckstroms in Quantenkaskadenlasern werden präsentiert. Unser Ansatz liefert eine Methode zur effektiven Analyse von der QCL-Leistung und Vereinfacht die Optimierung von QCL aktive Regionen.<br>Two decades after their invention in 1994, quantum-cascade lasers (QCLs) become increasingly important in the global infrared optoelectronics market. Photoacoustic spectroscopy, environment monitoring, hot object simulation, and free-space communication systems are selected examples of the current and potential applications of QCLs. Record optical powers as large as 14 W and power-conversion efficiencies ranging between 15-35 % have been reported for MIR QCLs for temperatures 80-300 K. Further improvement of these characteristics depends not only of aspects as heat management and chip-packaging, but also on improving the active-region design to reduce several leakage channels of charge carriers. However, mechanisms through which leakage of charge carriers affects QCLs performance have not been thoroughly researched. A better understanding of the several (non-radiative) scattering mechanisms involved in carrier transport in QCLs is needed to design new structures and optimize their performance. This work provides a realistic description of charge carriers transport in QCLs. We discuss in particular carrier leakage from QCL quantum-well confined states into higher and lower states. The two main mechanisms for non-radiative intersubband scattering in MIR QCLs are electron-longitudinal-optical-phonon scattering and interface roughness-induced scattering. We present methods for the experimental determination of the leakage current in QCLs at and above laser threshold, which allowed us to estimate the sheet distributions of conduction band states and better understand the impact of temperature activated leakage on QCLs characteristics. We found that even at temperatures low enough to neglect ELO scattering, carriers leakage due to IFR becomes significant for devices operating at high electron temperatures. Altogether, this approach offers a straightforward method to analyze and troubleshoot new QCL active region designs and optimize their performance.
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Gabriel, Schenk. "A type of king : the figure of Arthur in mid-nineteenth to mid-twentieth century literature." Thesis, University of Oxford, 2014. http://ora.ox.ac.uk/objects/uuid:6c284cea-e72c-49b0-ba87-29cf7b960ba9.
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This thesis analyses the figure of Arthur, in a period spanning the mid-nineteenth to mid-twentieth centuries, when that figure became increasingly protean and multifaceted, and the audience for the Arthurian legend grew in both size and variety. It argues that many authors wrote through Arthur, as well as about Arthur, using the figure to understand and test their own ideas about ideals (e.g. of manliness, kingship, or heroism) as well as problems (such as war, despotism, or ungodliness). This thesis analyses Arthur by considering him as a 'type', using a definition of the term that highlights a paradox: a type, in a scientific sense, is both perfect (an exemplary model) and normal (common enough to be representative). When applied to Arthur, it means that he is both a perfect, or near perfect, example, but is also to some extent a 'normal' human being. Different authors analysed in this thesis emphasise different aspects of the figure, according to whether they focus on Arthur's perfection or his normality. Other meanings of the word 'type' are also applied when relevant: the idea is not to force all versions of Arthur into a single or definitive category, but to retain the complexity of how Arthur is characterised and written about in texts. The ultimate aim of this thesis is to put the figure of Arthur into critical focus, and explain why he has been returned to so often in history.
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Yeo, Isobel Alice L. "Detailed studies of mid-ocean ridge volcanism at the Mid-Atlantic Ridge (45°N) and elsewhere." Thesis, Durham University, 2012. http://etheses.dur.ac.uk/4944/.
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This thesis provides a comprehensive study of the Axial Volcanic Ridge (AVR) at 45˚30 N on the Mid-Atlantic Ridge. A number of datasets were collected over the area, including: EM120 ship based bathymetry, TOBI sidescan sonar, Isis high-resolution bathymetry, Isis video and sampling dives and crustal magnetisation surveys. In this thesis I seek to explore the questions of the volcanic building blocks of AVRs and their spatial and temporal evolution in a number of ways. Very detailed volcanological mapping of the seafloor is used to provide semi-quantitative estimates of the relative proportions of different lava morphologies on and off the AVR and within the upper oceanic crust. I find that the AVR is characterised by predominantly pillow lavas while the flatter areas of seafloor around the AVR are covered by higher effusion rate lava morphologies. These observations are combined with the bathymetry and sidescan sonar datasets to elucidate the detailed nature of the building blocks of AVRs, which I find to be volcanic hummocks, composed predominantly of pillow lavas. These hummocks are morphologically the same as pillow mounds described at intermediate-spreading rate ridges. From these observations we identify common collapse scarps and associated talus deposits, which if buried may contribute significantly to increased porosity and lower seismic velocity in seismic layer 2A. Sediment cover is used as a proxy for seafloor age, and suggests that both the AVR and the flat seafloor around it are a similar age. Statistical analysis of the distribution and size of volcanic hummocks on the AVR finds their numbers to have been vastly underestimated in previous studies. I also show that hummock density is very variable across the AVR, possibly corresponding to many discrete melt sources. Evidence from 45˚N does not support either a uniform, long period life cycle model as has been proposed, or a steady state AVR. Instead I suggest that the AVR is the surface representation of robust magma supply, and irregular nature of this melt supply will control the surface appearance of the AVR.
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Castro, Esparza Alejandra. "Algoritmo Genético para el problema de formación de Células de Manufactura con secuencia." Thesis, Universidad de las Américas Puebla, 2013. http://catarina.udlap.mx/u_dl_a/tales/documentos/mid/castro_e_a/.
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En esta tesis se estudia el Problema de Formación de Células de Manufactura
(MCFP por sus siglas en inglés) que considera la secuencia de las partes, se
aplica un algoritmo genético para resolver este problema. El algoritmo intenta
reducir al máximo los movimientos intercelulares, asignado cada máquina a la
célula más conveniente de tal manera que se minimicen dichos movimientos.
El algoritmo propuesto utiliza un procedimiento de búsqueda local para
mejorar la calidad de las soluciones. El algoritmo propuesto obtiene buenos
resultados ya que tuvo la capacidad para encontrar todos los resultados
óptimos para todas las instancias de prueba por lo menos en una ocasión.
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Gopalan, Kavitha Kalavoor. "Optical surfaces for mid-infrared sensing." Doctoral thesis, Universitat Politècnica de Catalunya, 2018. http://hdl.handle.net/10803/663484.
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The mid-infrared (mid-IR) spectral region, with wavelengths between 3 and 15 µm, is known for a wide range of applications ranging from spectroscopic sensing to thermal imaging. However, despite the strong technological interest, optoelectronic devices in the mid-IR are expensive and often inferior in performance compared to their visible and near-IR counterparts.
In this thesis, we combine ultrathin materials, e.g. graphene, and novel substrates to develop optical surfaces for applications in the mid-IR.First, we demonstrate a novel uncooled photodetector, combining graphene with a ferroelectric (pyroelectric) substrate. More specifically, we develop a graphene on z-cut lithium niobate (LiNbO3) pyro-resistive platform that supports dynamic tunablity of the responsivity. We also develop a model to identify the key parameters that influence the performance of such detectors and can therefore provide guidelines to improve their performance.
Second, we introduce ultra-thin yttria-stabilized zirconia (YSZ), a ceramic material, as a novel platform for IR nano-optics. In particular, we combine YSZ substrates with metallic nanostructures and graphene to demonstrate plasmonic, polarizing and transparent heating devices, which enable high temperature processing and can withstand harsh environments thanks to the high thermal and chemical stabilities of YSZ. Additionally, the mechanical flexibility of YSZ substrates also makes them ideally suited for manufacturing foldable or bendable devices and for low cost large-scale roll-to-roll fabrication processes. Finally, we investigate for the first time electrostatically tunable graphene nano-hole array surfaces by performing a detailed experimental study of structures with periods as low as 100 nm. We obtain a clear plasmonic response from these surfaces in the range 1300-1600 cm-1. We also demonstrated for the first time that these tunable nanostructures can be fabricated by scalable nano-imprint technique. Such large area plasmonic nanostructures are suitable for industrial applications, for example, surface-enhanced infrared absorption (SEIRA) sensing. This is because they combine an easy design, extreme field confinement and the possibility to excite multiple plasmon modes for multiband sensing, a feature not readily available in nanoribbons or other localized resonant geometries.
The results contained in this thesis are particularly relevant with regard to extending the use of materials, such as graphene combined with specific substrates (LiNbO3 or zirconia), to mid-IR photodetection, enhanced absorption and molecular sensing.<br>La región espectral del infrarrojo medio (mid-IR), de longitudes de onda entre los 3 y los 15µm, se conoce por su vasto número de aplicaciones: desde la detecciónespectroscópica hasta la imagen térmica. No obstante, a pesar de su gran interéstecnológico, los dispositivos optoelectrónicos en el mid-IR son caros y, a menudo,con rendimientos inferiores al compararlos con sus homólogos en la región visibley en el infrarrojo cercano. En esta tesis, combinamos materiales ultrafinos(e.g. grafeno) con nuevos substratos para desarrollar superficies ópticas conaplicaciones en el mid-IR.Primero, mostramos los resultados de un fotodetector innovador, que nonecesita ser enfriado, fabricado combinando grafeno con un substrato ferroeléc-trico (piroeléctrico). Más específicamente, desarrollamos un artefacto de grafenodispuesto sobre niobato de litio (LiNbO3) cortado en la dirección z, que admiteuna modulación dinámica de su capacidad de respuesta. También desarrollamosun modelo matemático con el propósito de identificar los parámetros claves queinfluyen en el rendimiento de estos fotodetectores y, en consecuencia, propor-cionar una serie de pautas para mejorarlo. En segundo lugar, introducimos la circonita estabilizada con óxido de itrioultrafina (YSZ) como material cerámico vanguardista en el campo de la nanoóp-tica en el IR. En particular, combinamos substratos de YSZ con nanoestructurasmetálicas y grafeno para demostrar la idoneidad de dispositivos plasmónicos,transparentes y polarizadores, que posibilitan el procesamiento a alta temper-atura y que pueden soportar condiciones ambientales más duras gracias a laexcelente estabilidad térmica y química de la YSZ. Además, la flexibilidad delos substratos de YSZ hace de éstas, unas estructuras ideales para la manufactura de dispositivos flexibles y plegables, cuyo proceso rollo-a-rollo de fabricacióna gran escala es de bajo coste. Finalmente, investigamos por vez primera las superficies de grafeno modu-ladas electrostáticamente con patrones de nano-orificios, cuyos periodos llegana distancias tan pequeñas como los 100 nm, por medio de un exhaustivo estudioexperimental. A través del mismo, obtenemos una respuesta plasmónica claraen el rango de los 1300-1600cm-1. También demostramos por primera vez, queestas nanoestrucutras modulables pueden ser fabricadas mediante técnicas es-calables de nanoimpresión. Las grandes dimensiones de dichas nanoestructurasplasmónicas, las hacen plenamente apropiadas para aplicaciones industrialescomo, por ejemplo, la detección por absorción infrarroja amplificada de super-ficie (SEIRA, por sus siglas en inglés). Esto ocurre debido a que combinan undiseño simple, con un confinamiento extremo del campo y con la posibilidad deexcitar diferentes modos plasmónicos, lo que es de gran utilidad para la detec-ción multi-banda, una característica difícil de conseguir con cintas de grafeno uotras geometrías localizadas resonantes. Los resultados integrados en esta tesisson particularmente relevantes con respecto a la extensión de la utilización demateriales como el grafeno en combinación con substratos específicos (LiNbO3o circonita) para la fotodetección en el mir-IR, la absorción amplificada y ladetección molecular.
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Lam, Lai-kwan, and 林麗君. "Messianic elements in mid-Tang thought." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2001. http://hub.hku.hk/bib/B31953086.
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Pointon, Vivien Frances Turner. "Mid-Victorian Plymouth : a social geography." Thesis, University of Plymouth, 1989. http://hdl.handle.net/10026.1/1099.
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In the 19th century, the two settlements of Plymouth and East Stonehouse grew and coalesced into one urban area. Natural population increase and immigration both contributed to the rapid population growth which gave impetus to the urban expansion. Analysis of the unpublished census manuscripts for I85I and I87I revealed clear patterns of distrihution indicating segregation according to demographic, occupational and birthplace characteristics. There was severe overcrowding, population density was higher than that of mid-Victorian London and Liverpool, and the consequences for local public health and on the morphology of the urban area were substantial. Deprivation and poverty occurred not only in the older, cramped parts of Plymouth but also i n newly-built housing areas, such was the demand for accommodation. This provided an impetus for suburbanisation. Mid-Victorian Plymouth was a thriving, cosmopolitan trading port with a large fishing fleet and it was an important military and naval base. The town also served southwest Devon and southeast Cornwall as a market for local goods and produce. The local economy supported a wide-ranging employment structure, responding to infrastructural improvements, and provided a magnet for immigrants primarily from rural Devon and Cornwall but also from many other parts of Britain and from Ireland. Women formed a greater than average section of the local population, the towns attracted country girls to work as domestic servants and, also, many women were temporarily deserted as their husbands' occupations took them away from home. Principal component analyses show that, following a rapid phase of population growth i n the 1840s and 1850s, the combined population of Plymouth and Stonehouse entered a period of slower growth when immigration gave way to natural increase. The later phase is identified as a time of consolidation as immigrants settled and the local economy prospered, the population became more integrated and homogeneous.
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Wood, R. G. "Rossby waves in mid-latitude oceans." Thesis, University of Essex, 1987. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.379474.
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Landick, Marie. "The determination of French mid-vowels." Thesis, King's College London (University of London), 1990. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.301734.
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Sommerville, R. "Mid-course guidance for artillery projectiles." Thesis, Cranfield University, 1996. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.338034.
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Ryley, Joshua Claydon. "Turbine blade mid-chord internal cooling." Thesis, University of Oxford, 2014. http://ora.ox.ac.uk/objects/uuid:14469a51-517c-400c-b477-4fb432c8b648.
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Modern gas turbine engines operate at temperatures well above the melting point of the metal components. This has driven manufactures to develop sophisticated cooling methods which minimise the use of coolant to maximise engine efficiency by enabling further increases in operating temperature. This thesis investigates the cooling performance of engine representative mid-chord internal cooling passages for turbine blades. The work forms part of a larger E.C. FP7 project ERICKA (Engine Representative Internal Cooling Knowledge Applications).This thesis provides detailed maps of heat transfer coefficient (HTC) under a number of conditions, new experimental techniques, and has lead to a better understanding of the impact HTC distributions have on the thermal performance of a turbine blade at engine conditions. Transient liquid crystal experiments have been conducted on a large scale model of an engine representative internal cooling passage at three aspect ratios (width:height (chord length:spanwise length), 1:2, 1:3 and 1:4). Spatially resolved maps of Nusselt number have been produced for the full surface of the internal cooling passages. Little information exists in the literature for more engine representative geometries, and it is rare for spatial measurements to be presented over the full surface. The detailed maps provide validation data for CFD within the ERICKA programme. A novel method which produces spatially resolved maps in areas with highly non-one-dimensional heat transfer has been developed and validated. This method couples transient finite element analysis and data from transient liquid crystal experiments. Applied to the ribbed passage geometry, this produced spatially resolved maps of HTC over the rib surface. To the author’s best knowledge this is the first time spatial HTC maps have been presented for an engine representative rib. Industry best practice methods for internal cooling passage design typically apply averaged values of HTC, in part due to lack of spatially resolved data. To determine the significance of this approximation on blade design and life, experimental measurements have been applied to finite element (FEA) models at typical engine conditions. Application of a 3D HTC distribution to a FEA model of a section of ribbed wall demonstrated a significant under prediction (up to 58%) of localised thermal gradients when an average value is applied compared to a spatially resolved profile. This work demonstrated good agreement between distributions taken from experimental data and CFD predictions, indicating that CFD distributions may be more appropriate than bulk values in the design process. A 2D FEA study was undertaken to quantify the impact of HTC distribution approximations and aspect ratio on cooling of a generic turbine section. This study considered multiple adjacent internal cooling passages. It was confirmed that multi-pass arrangements offer greater heat removal for a given mass flow rate. Also a symmetric heat transfer profile with a higher HTC on the ribbed wall is the most desirable distribution. Use of average values significantly impacted the metal temperature, causing an underprediction up to 13◦C and 8◦C in the maximum and average values respectively. Based on the experimental HTC data, the 1:3 aspect ratio passage offered the lowest metal temperatures. Applying HTC distributions from CFD data (calculated with using the centreline temperature) showed, in general, good agreement, with the lowest metal temperatures (by up to 8◦C) in the 1:4 aspect ratio passage. Use of and HTC distribution provided by CFD prediction based on the mixed bulk temperature, produced average and peak metal temperatures 16◦C and 17◦C, respectively, lower in the 1:4 aspect ratio passage than the next best design. This highlights the need for appropriate and consistent method to be used in the analysis. As expected, reducing the passage aspect ratio led to increases in both thermal gradient and total pressure loss.
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McKerracher, Mark James. "Agricultural development in Mid Saxon England." Thesis, University of Oxford, 2014. http://ora.ox.ac.uk/objects/uuid:42a637f9-eac7-4a37-bc4b-20403dd7c974.
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Over the past decade, historians and archaeologists have become increasingly aware that the Mid Saxon period in England (7th-9th centuries AD) witnessed a transformation in agricultural practices. According to the emergent consensus, in contrast to the heavily pastoral, broadly subsistence-based mode of agriculture characteristic of the Early Saxon period (5th-7th centuries), Mid Saxon agriculture was geared towards higher levels of surplus production and placed a greater emphasis upon arable farming. The increased cultivation of bread wheat and the specialist production of sheep’s wool have been identified as particularly important innovations of this period. This thesis represents the first attempt to explore agricultural development in Mid Saxon England on a systematic archaeological basis. It considers settlement, zooarchaeological, and archaeobotanical evidence in detail, with a special emphasis on charred plant remains. The analyses utilize data gathered from excavation reports, published and unpublished, covering two case study regions: (i) the Upper/Middle Thames valley and environs, and (ii) East Anglia and Essex. In addition, a sub-assemblage of charred plant remains from a Mid Saxon monastic site at Lyminge (Kent) is studied at first hand. In this way, a series of agricultural innovations is identified in the archaeological record, including in particular: specialized pastoralism, an increased emphasis on sheep in some regions, an expansion of arable production, growth in fibre production, growth in cereal surpluses, a consequent investment in specialist storage and processing facilities, and a general diversification of crop spectra. These innovations were contingent upon, and adapted to, local environmental factors. The process of agricultural development is thought to have begun in the 7th century and continued through the 8th and 9th centuries, facilitated and stimulated by newly consolidated élite landholdings and, probably, a growing population.
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Alker, Z. "Street violence in mid-Victorian Liverpool." Thesis, Liverpool John Moores University, 2014. http://researchonline.ljmu.ac.uk/4483/.
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Shen, Li. "Semiconductor waveguides for mid-infrared photonics." Thesis, University of Southampton, 2015. https://eprints.soton.ac.uk/386873/.
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Mid-infrared semiconductor photonics is an emerging field with wide ranging applications. One stream of research is focused on extending the well-developed silicon-based waveguide platforms into longer wavelength regimes because of the inherent transparency window of silicon in the mid-infrared regime as well as its favourable nonlinear properties. Alternative approach is to investigate the optical properties of new materials (i.e. germanium) that offer favourable properties such as broader transparency windows and large nonlinearities, etc. In this thesis, two types of novel mid-infrared waveguide platforms were investigated. The first was the semiconductor optical fibres, an innovative platform that incorporates the functional semiconductors within the robust fibre geometry. A range of different core materials were characterised from the telecommunications band into the mid-infrared regime including polycrystalline silicon, hydrogenated amorphous silicon and hydrogenated amorphous germanium. Particularly, the large nonlinearity of the hydrogenated amorphous silicon core fibres was measured systematically cross this wavelength regime previously unknown for these fibres. With the knowledge of the key nonlinear parameters including nonlinear absorption and refraction, supercontinuum generation was demonstrated in the mid-infrared where the two-photon absorption was negligible. The measurements in the mid-infrared represent the first characterisation of the material beyond 1.55 μm. The second platform was the germanium on silicon waveguides, which can be fabricated using similar techniques to the silicon integrated waveguides and are thus compatible with the widely used complementary metal-oxide-semiconductor platform. The results presented in this thesis represent the first comprehensive linear and nonlinear transmission loss characterisations of this new class of waveguide for selected mid-infrared wavelengths. By exploiting the free carriers and two-photon absorption mechanisms, high speed all-optical modulation was demonstrated across selected mid-infrared wavelengths.
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Alexander, Amanda S. "Mid-Ohioan's perceptions of fair trade." The Ohio State University, 2007. http://rave.ohiolink.edu/etdc/view?acc_num=osu1406626549.
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Werner, Kevin Thomas. "Ultrafast Mid-Infrared Laser-Solid Interactions." The Ohio State University, 2019. http://rave.ohiolink.edu/etdc/view?acc_num=osu1546542784608798.
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Braithwaite, Karen. "Stratigraphy of the mid-Carboniferous boundary." Thesis, University of Leeds, 1995. http://etheses.whiterose.ac.uk/160/.
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This study investigates the stratigraphy of the newly defined mid-Carboniferous boundary. The selection of the mid-Carboniferous stratotype section should reconcile problems between the different mid-Carboniferous biostratigraphies developed throughout the world and provide a standard against which other successions can be correlated. The nature of the mid-Carboniferous boundary in the Clare Basin has been investigated. Various geochemical analyses have been conducted on a mid-Carboniferous section and it has been possible to construct a chart relating these various geochemical parameters to relative sea-level. It is shown that although deposition is complete through the interval, there is a geochemical expression of a lowstand during the lowest Chokierian. Additionally, doubt is cast on the presumption that all sediments deposited outside 'marine bands' are non marine. A model has been developed for mid-Carboniferous deposition in the Clare Basin. It is envisaged that the shelves of the Clare Basin were flooded during the early Namurian leading to an environment suitable for phosphate authigenesis. During a major regression in the Pendleian/lower Arnsbergian the phosphate was reworked into a lag. The lowstand of the basal Chokierian is marked by a thin lag on the shelves, whilst deposition was continuous in the basin centre. Later Chokierian times are marked by a widespread transgression. The mid-Carboniferous stratotype has been chosen at Arrow Canyon,Nevada. Microfacies studies show that deposition was on a winnowed carbonate platform showing reworking of bioclasts. Faunal diversity and eveness studies have also been conducted on this section. No drop in diversity is seen at the mid-Carboniferous boundary, although a drop in eveness is seen, whether this relates to a specialised fauna or selective winnowing of bioclasts is unknown. Correlations between America and western Europe show that conodonts are strongly facies controlled and it is unlikely that the appearance of Declinognathodus noduliferus is truly isochronous between sections, and thus is an unwise choice for defining the mid-Carboniferous boundary. Additionally it is suggested that Arrow Canyon was a poor choice for the stratotype section due to both the possibility of reworking, the presence of an unconformity in the section and possible doubts over the conodont record at this locale. The Rhachistognathus minutus zone is recognized as a new conodont zone across the Arnsbergian/Chokierian boundary.
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Keogh, Richard A. "Catholic loyalty in mid-Victorian Ireland." Thesis, Northumbria University, 2012. http://nrl.northumbria.ac.uk/36125/.
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Tsogkas, Stavros. "Mid-level representations for modeling objects." Thesis, Université Paris-Saclay (ComUE), 2016. http://www.theses.fr/2016SACLC012/document.
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Dans cette thèse, nous proposons l'utilisation de représentations de niveau intermédiaire, et en particulier i) d'axes médians, ii) de parties d'objets, et iii) des caractéristiques convolutionnels, pour modéliser des objets.La première partie de la thèse traite de détecter les axes médians dans des images naturelles en couleur. Nous adoptons une approche d'apprentissage, en utilisant la couleur, la texture et les caractéristiques de regroupement spectral pour construire un classificateur qui produit une carte de probabilité dense pour la symétrie. Le Multiple Instance Learning (MIL) nous permet de traiter l'échelle et l'orientation comme des variables latentes pendant l'entraînement, tandis qu'une variante fondée sur les forêts aléatoires offre des gains significatifs en termes de temps de calcul.Dans la deuxième partie de la thèse, nous traitons de la modélisation des objets, utilisant des modèles de parties déformables (DPM). Nous développons une approche « coarse-to-fine » hiérarchique, qui utilise des bornes probabilistes pour diminuer le coût de calcul dans les modèles à grand nombre de composants basés sur HOGs. Ces bornes probabilistes, calculés de manière efficace, nous permettent d'écarter rapidement de grandes parties de l'image, et d'évaluer précisément les filtres convolutionnels seulement à des endroits prometteurs. Notre approche permet d'obtenir une accélération de 4-5 fois sur l'approche naïve, avec une perte minimale en performance.Nous employons aussi des réseaux de neurones convolutionnels (CNN) pour améliorer la détection d'objets. Nous utilisons une architecture CNN communément utilisée pour extraire les réponses de la dernière couche de convolution. Nous intégrons ces réponses dans l'architecture DPM classique, remplaçant les descripteurs HOG fabriqués à la main, et nous observons une augmentation significative de la performance de détection (~14.5% de mAP).Dans la dernière partie de la thèse nous expérimentons avec des réseaux de neurones entièrement convolutionnels pous la segmentation de parties d'objets.Nous réadaptons un CNN utilisé à l'état de l'art pour effectuer une segmentation sémantique fine de parties d'objets et nous utilisons un CRF entièrement connecté comme étape de post-traitement pour obtenir des bords fins.Nous introduirons aussi un à priori sur les formes à l'aide d'une Restricted Boltzmann Machine (RBM), à partir des segmentations de vérité terrain.Enfin, nous concevons une nouvelle architecture entièrement convolutionnel, et l'entraînons sur des données d'image à résonance magnétique du cerveau, afin de segmenter les différentes parties du cerveau humain.Notre approche permet d'atteindre des résultats à l'état de l'art sur les deux types de données<br>In this thesis we propose the use of mid-level representations, and in particular i) medial axes, ii) object parts, and iii)convolutional features, for modelling objects.The first part of the thesis deals with detecting medial axes in natural RGB images. We adopt a learning approach, utilizing colour, texture and spectral clustering features, to build a classifier that produces a dense probability map for symmetry. Multiple Instance Learning (MIL) allows us to treat scale and orientation as latent variables during training, while a variation based on random forests offers significant gains in terms of running time.In the second part of the thesis we focus on object part modeling using both hand-crafted and learned feature representations. We develop a coarse-to-fine, hierarchical approach that uses probabilistic bounds for part scores to decrease the computational cost of mixture models with a large number of HOG-based templates. These efficiently computed probabilistic bounds allow us to quickly discard large parts of the image, and evaluate the exact convolution scores only at promising locations. Our approach achieves a $4times-5times$ speedup over the naive approach with minimal loss in performance.We also employ convolutional features to improve object detection. We use a popular CNN architecture to extract responses from an intermediate convolutional layer. We integrate these responses in the classic DPM pipeline, replacing hand-crafted HOG features, and observe a significant boost in detection performance (~14.5% increase in mAP).In the last part of the thesis we experiment with fully convolutional neural networks for the segmentation of object parts.We re-purpose a state-of-the-art CNN to perform fine-grained semantic segmentation of object parts and use a fully-connected CRF as a post-processing step to obtain sharp boundaries.We also inject prior shape information in our model through a Restricted Boltzmann Machine, trained on ground-truth segmentations.Finally, we train a new fully-convolutional architecture from a random initialization, to segment different parts of the human brain in magnetic resonance image data.Our methods achieve state-of-the-art results on both types of data
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Strand, Adam, and Kristoffer Edhborg. "Upptäcka vinstmanipulering med Den Modifierade Jonesmodellen : En studie på Stockholmsbörsens Mid cap lista." Thesis, Södertörns högskola, Institutionen för samhällsvetenskaper, 2013. http://urn.kb.se/resolve?urn=urn:nbn:se:sh:diva-18904.
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Syfte: Syftet med denna uppsats är att undersöka ifall vinstmanipulering förekommer bland företagen på Nasdaq OMX Nordic samt att analysera ifall att VD-byte är kopplat till detta fenomen. Metod: Studien har använt sig av Den Modifierade Jonesmodellen som är en periodiseringsbaserad modell för vinstmanipulering. Undersökningen är en kvantitativ studie och har utgått från årsredovisningar mellan åren 2007-2011 från börsnoterade bolag på Stockholms Mid Cap lista, totalt 295 observationer. Fyra hypoteser blir statistiskt testade. Teori: Denna del tar upp flera teorier som är kopplade till uppsatsens undersökning, bland annat genom Agentteorin och Designad redovisning. Agentteorin grundar sig på att alla individer nyttomaximerar, vilket kan vara en förklaring till varför redovisningsmanipulering existerar. Designad redovisning används för att nå förutbestämda mål genom att välja rätt redovisningsteknik. Inom denna teori finns flera begrepp och de som tas upp i uppsatsen är: vinstutjämning, vinstmanipulering samt kreativ redovisning i form av Big Bath. Dessutom tas tre tidigare vetenskapliga studier upp som undersöker kopplingar mellan VD-byten och vinstmanipulering: Resultat: Studien finner 35 VD-byten och majoriteten av de diskretionära periodiseringarna är negativa. De fyra testerna finner inga statistiska skillnader. Slutsatser: Undersökningen ger en indikation på att vinstmanipulering förekommer. Det framkommer ingen signifikant skillnad mellan år då VD-byte genomförts och år då det inte skett något byte.
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Scheffler, Thomas. "Chancen und Möglichkeiten des Duroplast für MID-Anwendungen." Technische Universität Chemnitz, 2014. https://monarch.qucosa.de/id/qucosa%3A20415.
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Lynch, Ryan. "High Returns and Low Volatility: The Case for Mid-Cap Stocks." Digital Commons @ East Tennessee State University, 2018. https://dc.etsu.edu/honors/450.
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This study examines excess risk-adjusted returns generated by mid-cap firms with an average market equity between $2.4 billion and $5.5 billion in 2017. Researchers have heavily studied the small-firm effect since its identification in the early 1980s, leading investors to overweight small-cap securities. Additional investments in the small-cap segment caused the small-cap anomaly to weaken. This study finds that excess returns of small-cap firms compared to mid-cap firms are not statistically significant in the periods 1946 – 2017 and 1982 -2017. However, mid-cap firms generate significantly higher 3-year average returns relative to small and large-cap firms after the initial identification of the small-cap anomaly (1982 – 2017). Further, mid-cap securities generate a higher risk-adjusted return after the small-cap anomaly was identified. This study hypothesizes the mid-cap anomaly results from greater growth potential for mid-caps relative to large-caps while still being large enough to weather economic storms. This study also hypothesizes that non-size related factors have the largest impact on the mid-cap segment. The results support the existence of a mid-cap anomaly; however, the results suggest the anomaly is not a result of the growth potential of firms within the segment. Additionally, the results suggest non-size related factors such as book-to-market and operating profitability have the smallest impact on mid-cap securities. Therefore, this study concludes excess returns generated by mid-cap securities represent a true anomaly that is not dependent upon non-size related factors.
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Tipton, Jessica Elizabeth. "Multilingualism in the Russian nobility : a case study on the Vorontsov family (mid-1700s to mid-1800s)." Thesis, University of Bristol, 2017. https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.761206.
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Le, Roux Petrus Jacobus. "The geochemistry of selected mid-ocean ridge basalts from the Southern mid-Atlantic ridge (40°- 55°S)." Doctoral thesis, University of Cape Town, 2000. http://hdl.handle.net/11427/4207.
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Summary in English.<br>Includes bibliographical references.<br>In 1993, dredge-sampling from 40.6°S to 525.5°S, during cruise 9309 of the R/V Maurice Ewing, greatly increased the number of basalts recovered from this section of the southern Mid-Atlantic Ridge (SMAR), and significantly expanded the global suite of samples from slow-spreading ridges.
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Hartsel, Laura M. "Why are mid-career teachers leaving the profession?" Ashland University / OhioLINK, 2016. http://rave.ohiolink.edu/etdc/view?acc_num=ashland1460392005.
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McDaniel, Sean A. "Mid-IR Ultrafast Laser Inscribed Waveguides and Devices." University of Dayton / OhioLINK, 2017. http://rave.ohiolink.edu/etdc/view?acc_num=dayton1512639558935449.
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Wiggan, Nickolas James. "Palynological insights into the Mid Jurassic dinoflagellate radiation." Thesis, University of Cambridge, 2017. https://www.repository.cam.ac.uk/handle/1810/269278.
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Dinoflagellates are a diverse group of flagellated eukaryotes, the majority of which are marine plankton, and are one of the most important groups of primary producers in the world’s oceans. The dinoflagellate fossil record is based on their zygotic resting cysts; this record indicates that the Bajocian of the Mid Jurassic (~170–168 Ma) represents a critical interval in dinoflagellate evolutionary history, marked by a rapid increase in the diversity of cysts from the family Gonyaulacaceae. From the Bajocian onwards, the Gonyaulacaceae have remained one of the most diverse and abundant groups of dinoflagellate cysts in the fossil record. Even so, Bajocian dinoflagellate cysts themselves have received relatively little study, leaving the patterns of this radiation unresolved. In this thesis, I examine the Bajocian diversification of gonyaulacacean dinoflagellate cysts in northwest Europe via quantitative palynological analysis, and relate this into a broader stratigraphic and palaeoenvironmental context. The dinoflagellate cyst record of the three key study areas demonstrates an increase in gonyaulacacean dinoflagellate cyst diversity through the Bajocian, irrespective of differing palaeoenvironmental settings. However, palynological and sedimentological data record systematic changes in lithostratigraphic composition and/or depositional environment which reflect changes in sea level. The integration of these data with biostratigraphic records indicates that the pattern of the radiation in Europe was strongly influenced by sea level, with the increase in gonyaulacacean diversity mirroring a major second-order transgression. On a finer scale, the main pulses of first appearances correlate with third-order transgressive episodes. A rise in sea level, coupled with changes in the tectonic configuration of ocean gateways, appears to have controlled the pattern of diversification in Europe. These palaeoceanographic changes may have enhanced water-mass transfer between Europe, the northwest Tethys Ocean, and the Hispanic Corridor, which promoted the floral interchange of dinoflagellates. Comparison to global data demonstrates that gonyaulacacean dinoflagellate cysts increased in diversity on a global scale through the Mid Jurassic. Whilst sea level rise and associated large-scale palaeoenvironmental shifts appear to have controlled the pattern of dinoflagellate cyst appearances in several regions (e.g. eastern Canada, Israel), there is no direct correlation between dinoflagellate cyst diversity and sea level rise on a global scale. Within dinoflagellate cyst assemblages from Europe, the spatial and temporal distribution of key taxa can be related to differing palaeoenvironmental settings of the basins studied; but certain patterns may reflect wider palaeoenvironmental drivers. Carbon isotope records generated for this thesis, and their correlation to other European sections, demonstrate that the Early Bajocian in Europe was marked by a positive shift in δ13C. Previous work has linked this carbon cycle perturbation to a phase of enhanced continental weathering and associated run-off. In several European basins, the Early Bajocian was marked by an acme of the genus Dissiliodinium; this genus may have bloomed in response to elevated nutrient levels. Intriguingly, a similar pattern is seen within dinoflagellate cyst assemblages from Australia, indicating this interval of palaeoenvironmental change may have had a global extent.
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Whittaker, Joanne. "Tectonic consequences of mid-ocean ridge evolution and subduction." University of Sydney, 2008. http://hdl.handle.net/2123/3971.
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Doctor of Philosophy(PhD)<br>Mid-ocean ridges are a fundamental but insufficiently understood component of the global plate tectonic system. Mid-ocean ridges control the landscape of the Earth's ocean basins through seafloor spreading and influence the evolution of overriding plate margins during midocean ridge subduction. The majority of new crust created at the surface of the Earth is formed at mid-ocean ridges and the accretion process strongly influences the morphology of the seafloor, which interacts with ocean currents and mixing to influence ocean circulation and regional and global climate. Seafloor spreading rates are well known to influence oceanic basement topography. However, I show that parameters such as mantle conditions and spreading obliquity also play significant roles in modulating seafloor topography. I find that high mantle temperatures are associated with smooth oceanic basement, while cold and/or depleted mantle is associated with rough basement topography. In addition spreading obliquities greater than > 45° lead to extreme seafloor roughness. These results provide a predictive framework for reconstructing the seafloor of ancient oceans, a fundamental input required for modelling ocean-mixing in palaeoclimate studies. The importance of being able to accurately predict the morphology of vanished ocean floor is demonstrated by a regional analysis of the Adare Trough, which shows through an analysis of seismic stratigraphy how a relatively rough bathymetric feature can strongly influence the flow of ocean bottom currents. As well as seafloor, mid-ocean ridges influence the composition and morphology of overriding plate margins as they are consumed by subduction, with implications for landscape and natural resources development. Mid-ocean ridge subduction also effects the morphology and composition of the overriding plate margin by influencing the tectonic regime experienced by the overriding plate margin and impacting on the volume, composition and timing of arc-volcanism. Investigation of the Wharton Ridge slab window that formed beneath Sundaland between 70 Ma and 43 Ma reveals that although the relative motion of an overriding plate margin is the dominant force effecting tectonic regime on the overriding plate margin, this can be overridden by extension caused by the underlying slab window. Mid-ocean ridge subduction can also affect the balance of global plate motions. A longstanding controversy in global tectonics concerns the ultimate driving forces that cause periodic plate reorganisations. I find strong evidence supporting the hypothesis that the plates themselves drive instabilities in the plate-mantle system rather than major mantle overturns being the driving mechanism. I find that rapid sub-parallel subduction of the Izanagi mid-ocean ridge and subsequent catastrophic slab break o_ likely precipitated a global plate reorganisation event that formed the Emperor-Hawaii bend, and the change in relative plate motion between Australia and Antarctica at approximately 50 Ma
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Poindexter, Scott H. "Analysis of mid-grade Naval aviator retention." Thesis, Monterey, Calif. : Springfield, Va. : Naval Postgraduate School ; Available from National Technical Information Service, 1998. http://handle.dtic.mil/100.2/ADA356023.
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Thesis (M.S. in Operations Research) Naval Postgraduate School, September 1998.<br>"September 1998." Thesis advisor(s): William Krebs, Samuel Buttrey. Includes bibliographical references (p. 53-55). Also available online.
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Medina, Valles María del Socorro. "Orographic enhancement of mid-latitude cyclone precipitation /." Thesis, Connect to this title online; UW restricted, 2005. http://hdl.handle.net/1773/10028.
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Fujita, Kazuue. "Mid-infrared InGaAs/InAlAs Quantum Cascade Lasers." 京都大学 (Kyoto University), 2014. http://hdl.handle.net/2433/192129.
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Coogan, Laurance Andrew. "Magma plumbing beneath the Mid-Atlantic Ridge." Thesis, University of Leicester, 1998. http://hdl.handle.net/2381/30468.
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A suite of fresh,~0.75 Ma old, gabbroic samples from ODP Hole 923A on the Mid-Atlantic ridge just south of the Kane Fracture Zone, 23°N, have been studied texturally and by electron probe and ion probe. This hole penetrated ∼70 mbsf recovering 40 m of core from the basal 55 m of the hole. The core is dominated by two interlayed lithologies: poikilitic olivine gabbros and brown-pyroxene gabbros, plus volumetrically minor microgabbros, oxide gabbros and leucocratic veins. Poikilitic olivine gabbros are plagioclase +/- olivine cumulates with relatively primitive mineral composition. Horizons of poikilitic olivine gabbros in the core represent magma chamber replenishment in which the replenishing magma ponded at the base of the chamber and fractionated. Variations in plagioclase trace element compositions (e.g. La/Nd and Ba/K) in part reflect compositional variation in their parental melts derived from the mantle. Calculated equilibrium melt compositions are highly LREE depleted (Lan/Ndn as low as 0.25). Brown-pyroxene gabbros are olivine - plagioclase - clinopyroxene cumulates which have more evolved mineral compositions than poikilitic olivine gabbros. A series of major and trace element characteristics of the rocks, and textural phenomena, indicate that post-cumulus processes were important in their formation. In particular, extreme variations in incompatible element abundances, and fractionation of Zr and Y (and REE's), from the core to rim of clinopyroxene crystals occurs. It is proposed that the fractionation of the interstitial melt was caused by reaction between migration interstitial melt and the crystal assemblage (magmatic metasomatism). This led to the interstitial melt becoming highly evolved in terms of incompatible elements whilst the major elements were efficiently buffered by the crystals.
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Hamza, Taha Mohamed. "Doped ZnO nanostructures for Mid Infrared plasmonics." Thesis, Lyon, 2017. http://www.theses.fr/2017LYSEC051/document.
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L'objectif de ce travail est de réaliser des substrats pour l’effet SEIRA (surface enhanced IR absorption) pour mesurer de faibles volumes de gaz ambiants possédant une signature moléculaire de 3,3 μm à 5,1 μm en exploitant la forte amplification de champ électrique due à la résonance plasmon de surface localisés. A cette fin, nous avons démontré la modulation des résonances de plasmon de surface localisées MIR (LSPR) dans les nanocristaux de ZnO dopés (NCs) dopés à Ga ou Al ainsi que dans des nanofils (NWs) de ZnO dopés Ga (GZO) et dans des nanofils coeur/coquille de ZnO/GZO. En ce qui concerne l’accordabilité de MIR LSPR dans les NC, nous avons modulé la résonance plasmon de surface dans des NC de ZnO dopés Ga et Al, de 3 à 5 μm en faisant varier la teneur en Al et en Ga de 3 à 9 at.%. L’incorporation des dopants s’est révélée homogène jusqu’à 6%. Au-delà (9%), l’incorporation était fortement hétérogène, révélant que la limite de solubilité était atteinte. Les NC présentent une faible activation des impuretés. L'activation était aussi faible que 8%. Les LSPR présentaient également un fort élargissement (largeur-à-mi-hauteur FWHM). Pour accroitre l'activation des dopants, nous avons synthétisés les NC dans des conditions pauvres en O et en passivant les NC synthétisés dans des conditions riches en O (en les isolant dans des matrices telles que Al2O3 et SiO2). Nous avons ainsi augmenté l'activation de 8% à 20% pour les deux stratégies. De plus, l'incorporation des NC dans les matrices a réduit l'élargissement spectral de moitié (de 2200 cm-1 pour les NC déposés à 1100 cm-1 pour les NC noyés en matrice). En correspondance, les effets d’auto-assemblage des nanocristaux sur leur LSPR ont été modélisés par simulation FDTD. Cela a fourni des indications quant aux mécanismes responsable de l’élargissement inhomogènes des LSPR de nanocristaux de GZO. Outre les nanoparticules, nous avons étudié des nanofils ZnO dopés Ga (GZO) et coeur/coquille (ZnO/GZO) synthétisés par CVD d’organométalliques . La première conclusion importante est que le gallium produit un fort effet surfacatnt lors de la croissance MOCVD de GZO. Au lieu de former des nanofils de section hexagonale, l’introduction de Ga modifie nettement l’énergie de surface des faces latérales et conduit à al formation de structures de type « sapins de Noël ». Ce constat est aussi valable pour les coquilles de GZO déposées sur coeur de ZnO. Dans ce cas, les coquilles démouillent et forment des structures hiérarchiques en branches. Concernant les propriétés optiques de ces objets, les mesures de FTIR-photo acoustiques ont démontré une signature d’absorption reliée à la présence de Ga et pouvant être accordée selon la teneur en Ga. Cette absorption reproduit le comportement d’une résonance plasmon de surface. Cette résonance a pu être accordée de 1600 à 1900 cm-1<br>The scope of this thesis is about developing SEIRA (surface enhanced IR absorption) platform to probe low volumes of environmental gases that possess molecular signature from 3.3 μm to 5.1 μm leveraging the high field amplification of localised surface plasmon resonance (LSPR). To realise SEIRA, we demonstrated tuning MIR LSPR in Al or Ga doped ZnO nanocrystals (NCs) as well as in GZO or core-shell (ZnO/GZO) nanowires (NWs). Regarding tuning MIR LSPR in NCs, we demonstrated tunable MIR LSPR in Ga and Al doped ZnO NCs from 3 to 5 μm varying the Al or Ga content from 3 to 9 at.%. The incorporation of dopant was homogeneous up to 6%. At 9% dopant concentration, the incorporation was inhomogeneous, revealing the solubility limit has been reached. However, the NCs exhibited low activation of impurities. The activation was as low as 8%. The LSPR were characterised by large broadening as well. In order to enhance the dopant activation, we synthesized the NCs in O-poor conditions as well as passivated the NCs fabricated in O-rich condictions (by isolating and embedding them in matrices such as Al2O3 and SiO2 matrices). Both strategies improved the dopant activation from 8% up to 20%. Moreover, for assemblies of NCs dispersed in matrices, the broadening (FWHM) of the LSPR was reduced by half (from 2200 cm-1 in as-deposited NCs to 1100 cm-1 in embedded NCs). Correspondingly, the effect of the self-assembly of the nanocrystals on their LSPR was modeled by FDTD simulation and provided hindsight into the mechanisms responsible for the heterogeneous broadening of the LSPR. Finally, we have studied Ga-doped ZnO (GZO) and core-shell (ZnO/GZO) NW synthesized by MOCVD. The first important conclusion is that Ga plays a major surfactant role during the MOCVD growth of GZO. Instead of leading to hexagonal NWs, the introduction of Ga during the synthesis led to faceted “Christmas-tree” like architectures. The same observation held for core-shell ZnO-GZO nanowires; in the latter case, the GZO shell resulted in a dewetting branched architecture. Regarding their optical properties, photo-acoustic FTIR measurements revealed an absorption feature related to the Ga content, likely to be assigned to a plasmonic effect. This resonance could be tuned from 1600 to 1900 cm
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Gaiger, Frances Jean. "Mid-Pleistocene Extinction of Deep-Sea Ostracoda?" Thesis, University of Canterbury. Geological Sciences, 2006. http://hdl.handle.net/10092/1349.
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A global extinction event has been documented in protozoan foraminifera in the late Pliocene to Pleistocene. The timing of the extinction event varied depending on location, however for Ocean Drilling Project Site 1125, disappearances occurred between 2.5 and 0.57 Ma, with the major decline approximately 1.1 Ma. In order to determine if this event affected benthic organisms other than protozoans, this study was undertaken to determine how podocopid ostracods (Crustacea) recovered Ocean Drilling Program Site 1125 responded. The present study was hindered by the small number of valves recovered; the fact that a large proportion of taxa found were undescribed and new to science; and the current state of taxonomic scheme that is under significant revision. These factors meant that a comprehensive comparison could not be achieved. Despite this, counts of ostracod valves and assessments of diversity from this study reveal a significant increase in both parameters from approximately 900-600 ka. Three possible causes were investigated to account for this increase, sediment type and sample size; affects of taphonomy, mainly dissolution; or an actual biotic 'event'. Statistical analyses showed that although sample size did have some effect, it was not the sole reason for the increase in ostracod numbers. Dissolution had an expected affect on the percentage of juveniles but no correlations were found with other sample characteristics. Sedimentation rate was investigated but this also proved unrelated. Therefore, it is suggested that the increase in total ostracod valves and diversity which occurs between 900 and 600 ka was in fact a natural, biotic 'event'. This preliminary evidence suggests that an oceanographic event that has negatively impacted on the foraminifers has had the reverse affect on the ostracod assemblage, in the sense that both population size and diversity increase during that time.
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Rudnicki, Mark David. "Hydrothermal plumes at the Mid-Atlantic Ridge." Thesis, University of Cambridge, 1990. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.359701.
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