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Topics in finite graph Ramsey theoryBorgersen, Robert David 18 January 2008 (has links)
For a positive integer $r$ and graphs $F$, $G$, and $H$, the graph Ramsey arrow notation $F \longrightarrow (G)^H_r$ means that for every $r$-colouring of the subgraphs of $F$ isomorphic to $H$, there exists a subgraph $G'$ of $F$ isomorphic to $G$ such that all the subgraphs of $G'$ isomorphic to $H$ are coloured the same. Graph Ramsey theory is the study of the graph Ramsey arrow and related arrow notations for other kinds of ``graphs" (\emph{e.g.}, ordered graphs, or hypergraphs). This thesis surveys finite graph Ramsey theory, that is, when all structures are finite.
One aspect surveyed here is determining for which $G$, $H$, and $r$, there exists an $F$ such that $F \longrightarrow (G)^H_r$. The existence of such an $F$ is guaranteed when $H$ is complete, whether ``subgraph" means weak or induced, and existence results are also surveyed when $H$ is non-complete. When such an $F$ exists, other aspects are surveyed, such as determining the order of the smallest such $F$, finding such an $F$ in some restricted family of graphs, and describing the set of minimal such $F$'s.
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Étude d'un problème d'optimisation en aéroélasticité avec incertitudesArnaud, Rémi 10 April 2014 (has links) (PDF)
La recherche en optimisation est un secteur crucial pour les constructeurs aéronautiques. La performance des appareils est un élément déterminant dans la compétition commerciale qui oppose les principaux manufacturiers du marché. L'incorporation de plus en plus massive des matériaux composites dans les avions de ligne dans les années 2000 illustre le désir des constructeurs de réduire la masse de leurs appareils pour en diminuer la consommation de kérozène. Parallèlement, la sécurité est devenue au fil des années une préoccupation majeure pour l'ensemble des acteurs. Cependant, l'emploi massif de matériaux composites, dont les propriétés physiques sont très intéressantes pour les constructeurs mais qui sont conçus avec une marge de tolérance pour des raisons de coût, induit des variations indésirables dans la structure, des incertitudes. Outre ces matériaux, d'autres éléments non prévisibles sont susceptibles de perturber la structure de l'appareil. Le modèle d'un avion en avant-projet est toujours amené à évoluer pour répondre aux évolutions des exigences du constructeur, mais des études de faisabilité doivent être menées avant que la structure ne soit totalement définie, afin de s'assurer de la viabilité du modèle. Des éléments non pris en compte dans la structure, comme les câbles, peuvent également avoir une influence non négligeable sur le comportement global de l'appareil. Ces incertitudes ont un impact non négligeable sur la stabilité de la structure en vol. Des études ont commencé à incorporer cet aspect incertain dans les processus d'optimisation, mais généralement en adaptant les algorithmes existants et sans exploiter la nature incertaine des problèmes. Afin de tenir compte de l'aspect incertain, on se propose de représenter ces incertitudes par des variables aléatoires et d'exploiter des outils théoriques développés dans d'autres domaines, notamment les outils des mathématiques financières.
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Topics in finite graph Ramsey theoryBorgersen, Robert David 18 January 2008 (has links)
For a positive integer $r$ and graphs $F$, $G$, and $H$, the graph Ramsey arrow notation $F \longrightarrow (G)^H_r$ means that for every $r$-colouring of the subgraphs of $F$ isomorphic to $H$, there exists a subgraph $G'$ of $F$ isomorphic to $G$ such that all the subgraphs of $G'$ isomorphic to $H$ are coloured the same. Graph Ramsey theory is the study of the graph Ramsey arrow and related arrow notations for other kinds of ``graphs" (\emph{e.g.}, ordered graphs, or hypergraphs). This thesis surveys finite graph Ramsey theory, that is, when all structures are finite.
One aspect surveyed here is determining for which $G$, $H$, and $r$, there exists an $F$ such that $F \longrightarrow (G)^H_r$. The existence of such an $F$ is guaranteed when $H$ is complete, whether ``subgraph" means weak or induced, and existence results are also surveyed when $H$ is non-complete. When such an $F$ exists, other aspects are surveyed, such as determining the order of the smallest such $F$, finding such an $F$ in some restricted family of graphs, and describing the set of minimal such $F$'s.
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Šípové jedy, jejich využití v toxikologii a medicíně / Arrow poisons, their us in toxicology and medicineBÁRTOVÁ, Lucie January 2010 (has links)
Abstract The introduction of physiologically and therapeutically effective drugs in anaesthetic treatment has meant a significant change. Their discovery has thus contributed to a minimisation of their negative effects on a living organism. As a result, anaesthesiology has become more controllable and safer. These new drugs translate into more comfort for the patient in the course of anaesthesiology as well as his or her rapid recovery resulting in a shorter period of hospitalisation. The research of new physiologically and therapeutically effective substances is a pre-requisition of a potential higher standard of medical care. Older substances, e.g. Alkuronium and Gallamin, which, due to their undesirable effects, have come out of use, have lost their significance. Nowadays, these substances have been generally replaced by substances with an intermedial effect, e.g. Rokuronium and Cisatrakurium, which, compared with Alkuronium and Gallamin, show a minimum of undesirable effects. One of the foremost objectives of the current pharmaceutical research is to find a replacement of Sukcinylcholin, which, in spite of its known side effects, has had a non-substitutable position in urgent intubation. As a result, its use is limited to out-patient application and a certain selection of patient categories. Let us hope that we shall see a replacement of Sukcinylcholin being introduced in treatment in the near future. This would mean a final solution of problems arising from its side effects limiting its scope of application.
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Sur la synchronisation et le cryptage de systèmes chaotiques à temps discret utilisant les techniques d'agrégation et la représentation en flèche des matrices / On synchronization and encryption of discrete-time chaotic systems using aggregation techniques and representation of arrow form matricesFilali, Rania Linda 04 June 2013 (has links)
L’objectif de cette thèse était de développer une méthode de synthèse de commande par retour d’état puis par observateurs offrant des conditions de synthèse non contraignantes dans le cas de systèmes non linéaires à temps discret. Dans cette méthode, est mise en exergue l’importance du choix de la description des systèmes sur l’étendue des résultats pouvant être obtenus lorsque la méthode d’étude de la stabilité est fixée. Ainsi l’utilisation des normes vectorielles comme fonction d’agrégation et du critère pratique de Borne et Gentina pour l’étude de la stabilité, associée à la description des systèmes par des matrices caractéristiques de forme en flèche de Benrejeb, a conduit à l’élaboration de nouvelles conditions suffisantes de stabilisation de systèmes dynamiques discrets non linéaires, formulées en théorèmes et corollaires. Ces résultats obtenus, sont ensuite exploités, avec succès, pour la formulation de nouvelles conditions suffisantes de vérification des propriétés de synchronisation pour les systèmes hyperchaotiques à temps discrets. Ensuite, le cas de synthèse d’observateur est validé dans deux types de transmission chaotique / The objective of this thesis was to develop a method for synthesizing control state feedback and observers by offering soft synthesis conditions in the case of nonlinear discrete-time systems. In this method, is highlighting the importance of choosing the systems description of the scope of what can be achieved when the stability study method is fixed. The use of of vector norms as an aggregation function and the practical Borne-Gentina criterion for stability study, associated to arrow form matrix of Benrejeb for system discription, lead to the development of new sufficient conditions for stabilization of nonlinear discrete dynamical systems, formulated as theorems and corollaries. These results are then used, with success, for the formulation of new sufficient conditions for checking properties of hyperchaotiques synchronization for discrete-time systems. Then, the synthesis of observer is validated in two types of chaotic transmission
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Tommy Atkins, War Office reform and the social and cultural presence of the late-Victorian army in Britain, c.1868-1899Gosling, Edward Peter Joshua January 2016 (has links)
This thesis examines the development of the soldier in late-Victorian Britain in light of the movement to rehabilitate the public image of the ordinary ranks initiated by the Cardwell-Childers Reforms. Venerated in popular culture, Tommy Atkins became a symbol of British imperial strength and heroism. Socially, however, attitudes to the rank-and-file were defined by a pragmatic realism purged of such sentiments, the likes of which would characterise the British public’s relationship with their army for over thirty years. Scholars of both imperial culture and the Victorian military have identified this dual persona of Tommy Atkins, however, a dedicated study into the true nature of the soldier’s position has yet to be undertaken. The following research will seek to redress this omission. The soldier is approached through the perspective of three key influences which defined his development. The first influence, the politics of the War Office, exposes a progressive series of schemes which, cultivated for over a decade, sought to redefine the soldier through the popularisation of military service and the professionalisation of the military’s public relations strategy and apparatus. A forgotten component of the Cardwell-Childers Reforms, the schemes have not before been scrutinised. Despite the ingenuity of the schemes devised, the social rehabilitation of the soldier failed, primarily, it will be argued, because the government refused to improve his pay. The public’s response to the Cardwell-Childers Reforms and the British perception of the ordinary soldier in the decades following their introduction form the second perspective. Through surveys of the local and London press and mainstream literature, it is demonstrated the soldier, in part as a result of the reforms, underwent a social transition, precipitated by his entering the public consciousness and encouraged by a resulting fascination in the military life. The final perspective presented in this thesis is from within the rank-and-file itself. Through the examination of specialist newspaper, diary and memoir material the direct experiences of the soldiers themselves are explored. Amid the extensive public and political discussion of their nature and status, the soldier also engaged in the debate. The perspective of the rank-and-file provides direct context for the established perspectives of the British public and the War Office, but also highlights how the soldier both supported and opposed the reforms and was acutely aware of the social status he possessed. This thesis will examine the public and political treatment of the soldier in the late-nineteenth century and question how far the conflicting ideas of soldier-hero and soldier-beggar were reconciled.
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Rubidium Packaging for On-Chip SpectroscopyHill, Cameron Louis 01 December 2015 (has links) (PDF)
This thesis presents rubidium packaging methods for integration using anti-resonant reflecting optical waveguides (ARROWs) on a planar chip. The atomic vapor ARROW confines light through rubidium vapor, increases the light-vapor interaction length, decreases the size of the atomic cell to chip scales, and opens up possibilities for waveguide systems on chips for additional optoelectronic devices. Rubidium vapor packaging for long-life times are essential for realizing feasibly useful devices. Considerations of outgassing, leaking and chemical compatibilities of materials in rubidium vapor cells lead to an all-metal design. The effect of these characteristics on the rubidium D2 line spectra is considered.
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Holmes, Alice, and Ezeulu: Western Rationality in the Context of British Colonialism and Western ModernitySchultz, Andrew B. 19 July 2007 (has links) (PDF)
This thesis examines Western rationality, contextualizing that subject in British colonialism and Western modernity. Using Scott Lash's description of academic characterizations of modernity, I explore the “high" modernity of the social sciences represented in the books Alice's Adventures in Wonderland by Lewis Carroll and The Hound of the Baskervilles by Arthur Conan Doyle. I then explore the cultural studies critique of that characterization of modernity in the book Arrow of God by Chinua Achebe. Using the theory of Jean Francois Lyotard, Martin Heidegger, and Theodor Adorno, I look at Western rationality through its manifestation in British colonialism. I argue that colonialism is a site where rationality's negative legacy is manifest, and that the paradoxical representations of rationality in the books by Carroll and Doyle indicate a problem with the assumption that Western rationality was a universal epistemology. Contrary to the British's own ideas of their rationality, I find that Western rationality is ultimately a culturally-grounded discourse. Using Chinua Achebe's Arrow of God, I examine the intersection between Western rationality and other forms of cultural knowledge, an intersection that occurred through British colonialism. Achebe argues against the universal model of Western rationality and posits instead a relative valuing of each culture's methods of arriving at truth. I use his novel to illustrate the limits of Western rationality and its claim to universality.
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Three-Dimensional Hydrodynamic Focusing for Integrated Optofluidic Detection EnhancementHamilton, Erik Scott 02 April 2020 (has links)
The rise of superbugs, including antibiotic-resistant bacteria, and virus outbreaks, such as the recent coronavirus scare, illustrate the need for rapid detection of disease pathogens. Widespread availability of rapid disease identification would facilitate outbreak prevention and specific treatment. The ARROW biosensor microchip can directly detect single molecules through fluorescence-based optofluidic interrogation. The nature of the microfluidic channels found on optofluidic sensor platforms sets some of the ultimate sensitivity and accuracy limits and can result in false negative test results. Yet higher sensitivity and specificity is desired through hydrodynamic focusing. Novel 3D hydrodynamic focusing designs were developed and implemented on the ARROW platform, an optofluidic lab-on-a-chip single-molecule detector device. Microchannels with cross-section dimensions smaller than 10 μm were formed using sacrificial etching of photoresist layers covered with plasma-enhanced chemical-vapor-deposited silicon dioxide on a silicon wafer. Buffer fluid carried to the focusing junction enveloped an intersecting sample fluid, resulting in 3D focusing of the sample stream. The designs which operate across a wide range of fluid velocities through pressure-driven flow were integrated with optical waveguides in order to interrogate fluorescing particles and confirm 3D focusing, characterize diffusion, and quantify optofluidic detection enhancement of single viruses on chip.
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Optofluidic Manipulation with Nanomembrane Platforms Used for Solid-State Nanopore IntegrationWalker, Zachary J. 16 June 2022 (has links) (PDF)
Nanopore technology has introduced new techniques for single particle detection and analysis. A nanopore consists of a small opening in a membrane on the nanometer scale. Nanopores are found in nature and are utilized for transporting molecules through biological membranes. Researchers have been able to mimic naturally forming biological nanopores and utilize them for a variety of sensing applications. Nanopores, fabricated either organically or inorganically, can be used for detecting biomarkers such as proteins, nucleic acids, and metabolites that translocate the membrane by way of the nanopore. Constant ionic current flow is measured through the nanopore by way of a sensitive ammeter. In the presence of a biomarker, the ionic current flow will be impeded, causing the electrical signal to drop. This drop uniquely corresponds to the type of particle passing through the nanopore. In this work, the thin membrane on which the nanopore resides is created through a newly developed meniscus shaped sacrificial technique. The sacrificial polymer material starts as a liquid and is confined to the microfluidic channel through the capillary effect, giving it the meniscus profile. It is used as a structural support on which a thin silicon dioxide layer is grown. The layer of oxide takes on the same natural meniscus shape as the sacrificial material. The polymer is subsequently etched, resulting in a hollow core liquid channel with a suspended meniscus membrane. This process allows a thin membrane to be fabricated on top of a microfluidic channel that ranges from 50-200 nm in thickness. The meniscus membrane is crucial to the success of nanopore formation. The nanoscale membrane allows for smaller, more precise nanopores to be created. Reduced nanopore dimensions are advantageous for the detection of smaller biomarkers. The platform described in this dissertation integrates solid-state naturally forming meniscus membranes with solid-core and optofluidic waveguides for nanopore detection applications. The waveguides allow for a particle trap to be introduced to the system. The ability to trap particles directly under the nanopore is critical to the speed of which the nanopore can operate. This dissertation focuses on the fabrication, characterization, and testing of an optofluidic platform that features a nanopore for rapid single molecule detection and analysis.
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