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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

On the construction of point processes in statistical mechanics

Nehring, Benjamin, Poghosyan, Suren, Zessin, Hans January 2013 (has links)
By means of the cluster expansion method we show that a recent result of Poghosyan and Ueltschi (2009) combined with a result of Nehring (2012) yields a construction of point processes of classical statistical mechanics as well as processes related to the Ginibre Bose gas of Brownian loops and to the dissolution in R^d of Ginibre's Fermi-Dirac gas of such loops. The latter will be identified as a Gibbs perturbation of the ideal Fermi gas. On generalizing these considerations we will obtain the existence of a large class of Gibbs perturbations of the so-called KMM-processes as they were introduced by Nehring (2012). Moreover, it is shown that certain "limiting Gibbs processes" are Gibbs in the sense of Dobrushin, Lanford and Ruelle if the underlying potential is positive. And finally, Gibbs modifications of infinitely divisible point processes are shown to solve a new integration by parts formula if the underlying potential is positive.
2

Medidas DLR e transições de fase tipo volume em shifts de Markov com alfabeto enumerável / DLR Measures and Volume-Type Phase Transitions in Markov shifts with Enumerable Alphabet

Beltrán, Elmer Rusbert Calderón 29 March 2019 (has links)
Introduzimos a extensão natural da definição de medida DLR para medidas sigma-finitas em shift de Markov com alfabeto enumerável. Provamos que o conjunto de medidas DLR contém o conjunto de medidas conformes associadas aos potenciais satisfazendo a condição de Walters. No caso BIP ou quando o potencial normaliza o operador de Ruelle, provamos que as noções de DLR e conformes coincidem. No shift de renewal obtemos uma caracterização de quando as medidas conformes são infinitas, estudamos o problema para descrever os casos em que o conjunto de medidas conformes pula de medidas finitas para infinitas quando consideramos altas e baixas temperaturas, respectivamente. / We introduce the natural extension of the definition of DLR measure for sigma-finite measures on countable Markov shifts. We prove that the set of DLR measures contains the set of conformal measures associated to Walters potentials. In the BIP case or when the potential normalizes the Ruelle\'s operator we prove that the notions of DLR and conformal coincide. On renewal type shifts we obtained a characterization when the conformal measures are infinite, we study the problem to describe the cases when the set of conformal measures jumps from finite to infinite measures when we consider high and low temperatures, respectively.
3

Study of The Effect of Convective Heat Transfer on Cooling of Overhead Line Conductors Based on Wind Tunnel Experimental Results / Studie av Effekten av Konvektiv Värmeöverföring vid Kylning av Ledningsledare Baserat på Experimentellt Resultat från Vindtunneln

Naim, Wadih January 2018 (has links)
It is important to keep an overhead power line within rated operating conditions. Thus,an accurate prediction of the conductor's thermal and electrical behavior leads to an increasein reliability and eciency. Under DLR operation, the current rating is adjustedbased on ambient weather and solar conditions to allow for dynamic line loading. Therating adjustment takes into account the cooling mechanisms acting on the conductor. Inthis thesis, cooling by means of convective heat transfer is studied based on wind tunnelexperimental measurements of three dierent conductor samples. Convection contributesto most of the cooling; however, it is aected by wind speed and direction. Two angle ofattacks were studied (40 and 90), where perpendicular ow was found to result in bettercooling. The location of boundary layer separation highly aects the surface distribution ofcooling, which is non-uniform. Oblique wind ow results in reduction in overall cooling dueto earlier boundary layer separation. Finally, the surface average convective heat transfercoecient correlates non-linearly with the Reynolds number, where higher wind speeds andlarger conductor diameters can lead to signicant improvements in cooling while keepingrelatively low current densities. The existing standards of IEEE and CIGRE were found tooverestimate the eect of convective cooling for the specic experimental cases. / Det är viktigt att hålla en kraftöverföringsledning inom nominella driftsförhållanden.Således leder en korrekt förutsägelse av ledarens termiska och elektriska beteende till en ökad tillförlitlighet och effektivitet. Under DLR-drift justeras nuvärdet baserat på omgivande väder och solförhållanden för att möjliggöra dynamisk belastning. Klassificeringsjusteringen tar hänsyn till de kylmekanismer som verkar på ledaren. I denna avhandling studeras kylning med hjälp av konvektiv värmeöverföring baserat på provning av vindtunnel av tre olika ledartyper. Konvektion bidrar till det mesta av kylningen. Det påverkas dock av vindhastighet och riktning. Två angreppsvinkelar studerades (40◦ och 90◦), där vinkelrätt flöde befanns resultera i bättre kylning. Placeringen av ytskiktseparationen har stor inverkan på ytfördelningen av kylning, vilken är ojämn. Skrå vindflöde resulterar i minskning av den totala kylningen på grund av tidigare separering av gränsskiktet. Slutligen korrelerar den ytvärdesöverföringskoefficienten för ytvärdet icke-linjärt med Reynolds-talet, där högre vindhastigheter och större ledardiametrar kan leda till signifikanta förbättringar i kylning samtidigt som relativt låga strömtäthet hålls. De befintliga standarderna för IEEE och CIGRE visade sig överskatta effekten av konvektiv kylning för de specifika experimentellafallen.
4

Simulation and Visualisation Software for an Elastic Aircraft for High Altitudes based on Game Engine Technology

Stamat, Liviu January 2018 (has links)
No description available.
5

Bacillus subtilis biofilm formation under extreme terrestrial and simulated extraterrestrial conditions

Fuchs, Felix Matthias 13 May 2020 (has links)
No description available.
6

Application des librairies de codons dégénérés à l'étude du mécanisme de repliement et de la stabilisation de la structure du domaine liant ras de Raf

Campbell-Valois, François-Xavier January 2005 (has links)
Thèse diffusée initialement dans le cadre d'un projet pilote des Presses de l'Université de Montréal/Centre d'édition numérique UdeM (1997-2008) avec l'autorisation de l'auteur.
7

Application des librairies de codons dégénérés à l'étude du mécanisme de repliement et de la stabilisation de la structure du domaine liant ras de Raf

Campbell-Valois, François-Xavier January 2005 (has links)
Thèse diffusée initialement dans le cadre d'un projet pilote des Presses de l'Université de Montréal/Centre d'édition numérique UdeM (1997-2008) avec l'autorisation de l'auteur.
8

Addressing Adaptive Structure Technology to Reduce the Airframe Noise(Link) / Adaptive Slat Design and Relative Stress & Damage Analysis

Sahin, Hakan January 2012 (has links)
ABSTRACTThe purpose of this thesis is to design and analyze the new generation leading edge slat of a commercial jet to reduce the structural noise with the application of new conceptual design approaches. Recent scientific research show that the leading edge slats account for the structural noise during the flight operation therefore, when the leading edge slat is deployed under different flight conditions, an open gap/slot is formed between the high lift device and the wing box. However, since the leading edge slat includes flexible sections, it is assumed that defining an adaptive system inside the leading edge slat may reduce the structural noise by utilizing bending properties of these flexible sections. Hence, electromechanical actuator designing gains also great importance in the whole process. In this study, we have used, finite element modelling of the slat structure to examine the required structural deformations and strengths; our work is based on the software ANSYS/Workbench. To be realistic in deciding the right geometry in the follow up steps, we have first studied a generic geometry having no aerodynamics or actuator forces application. The whole simulation was performed by defining dummy forces and dummy material properties. The simulation lead to having a global overview of the mechanical behaviour of the structure; further, once the influent parameters were tested, realistic aerodynamic forces and material properties were defined, and as a result of bending of the flexible sections the required gap closure was formed between the trailing edge of the slat and the wing box. Subsequently, the suitable actuator design and required strength analysis are also performed on the last section. This study has also proved that the use of adaptive systems on the leading edge slats improves flight comfort by reducing the structural noise and provides less fuel consumption; this is significant for the long run considerations of aeroplane manufacturers. / es Zentrum für Luft- und Raumfahrt e. V. (DLR)
9

Development of a Data Analysis Tool for the EDEN ISS Project

BRYSON, Christopher January 2022 (has links)
The EDEN ISS project, initiated by the German Aerospace Center (DLR) focuses on the development of greenhouses for future Space habitats on the Moon and Mars. For this, they run a full-size experiment in Antarctica in collaboration with NASA. This experiment is remotely controlled and monitored by the mission control team in Bremen, Germany. The aim of this thesis is to improve the accessibility of the data being pulled from the greenhouse in Antarctica and delivered to the mission control room. Furthermore, it promises to provide the EDEN ISS team with a set of tools to quickly and easily analyze historical data from the numerous sensors and devices currently installed inside the greenhouse module. To accomplish this, the development of a Data Analysis Tool was designed and programmed in Python, which generates accurate graphs and plots in a fast and user-friendly manner. This tool provides the user with a Graphical User Interface (GUI) which includes a set of easy-to-use tools to modify and manipulate the available data throughout the entire experiment’s lifetime, covering the years from 2018 to 2021. By using this tool, the EDEN ISS team can access relevant data and reach informed conclusions regarding the functionality and stability of the greenhouse experiment module in Antarctica.
10

What Are Radiologists' Perceptions in Regard to Image Quality and Increased Utilization Due to Vendor Provided Deep Learning Signal to Noise Ratio and Deep Learning Reconstruction on 3.0T Magnetic Resonance Imagine?

Venturi, Gianni 02 August 2023 (has links)
No description available.

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