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Dissertations / Theses on the topic 'Parallel Universes'
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1
Wynn, Freda A. "Alternative Realities/The Multiverse: A Metaphysical Conundrum." Digital Archive @ GSU, 2006. http://digitalarchive.gsu.edu/communication_theses/4.
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Films of every era reflect the concerns and fears of Western society. The acceleration of technology, the loss of a concrete world, the uneasy relationship with humans and ever increasing complex machines are inducing a fear of losing the ability to discern reality. The reality of ideas from science and the world around are woven into the narratives that we use to explain life.The films we watch reflect our hopes and fears and as the fears increase so do films with a shared theme of alternative realities. To know reality and search for the true Self is the job of the hero and the protagonist in recent alternative reality films.
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Lockridge, Tim. "Survival Tips For A Parallel Universe." Thesis, Virginia Tech, 2008. http://hdl.handle.net/10919/77492.
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Survival Tips For A Parallel Universe is a collection of poems concerned with sudden change, limitations, and the way those changes and limits might develop and burden intimate relationships. The collection’s central sequence, “Survival Tips For A Parallel Universe: Parts One, Two, Three, and Four,"? works through an imagined alternate world where the human and the mechanical suddenly and inexplicably merge, creating avenues of possibility that ultimately end in the unknowable, the unreachable, or failure. The surrounding poems further explore the nuance of the unknowable—through language both lyrical and plain-spoken—questioning reality and perception, specifically in their relation to memory, love, and desire. Likewise, the collection largely moves from a second person point-of-view to a first-person perspective, generating a shifting subject and a movement toward a tangible and more direct articulation of feeling and heart. While this collection draws a strong influence from the invention and tradition of the New York School of poetry, it also attempts a new way of speaking—and, in turn, a new way of knowing.Master of Fine Arts
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Wiswedel, Bernd. "Lernen in Parallelen Universen." [S.l. : s.n.], 2008. http://nbn-resolving.de/urn:nbn:de:bsz:352-opus-72999.
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Modir, Shanechi Maryam. "Universal codes for parallel Gaussian channels." Thesis, Massachusetts Institute of Technology, 2006. http://hdl.handle.net/1721.1/62894.
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Thesis (S.M.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 2006.Includes bibliographical references (p. 97).
In this thesis we study the design of universal codes for parallel Gaussian channels with 2 sub-channels present. We study the universality both in terms of the uncertainty in the relative quality of the two sub-channels for a fixed maximum rate, C*, and in terms of the uncertainty of the achievable maximum rate. In our architecture, we will convert the parallel Gaussian channel into a set of scalar Gaussian channels and use good base codes designed for the corresponding scalar channel in the coding schemes. In Chapter 2, a universal layered code with deterministic dithers is developed. The code is repeated across the two sub-channels with possibly different dithers. Symbols in each of the layer codewords can be combined using unitary transformations of dimension, m. A minimum mean squared error (MMSE) receiver combined with successive cancellation is used for decoding. We show that increasing m does not improve the efficiency. The efficiency increases by adding more layers up to a certain number and after that it saturates. We find an expression for this saturation efficiency. We show that partial CSIT improves the efficiency significantly. At the end we compare the performance of maximal ratio combining (MRC) and MMSE receivers and show that they are close in the coding scheme with no CSIT. In Chapter 3, we design an alternative universal code and extend it to be rateless. This is a sub-block structured code symmetric with respect to all layers that gets repeated across the two sub-channels and in time using i.i.d. Bernoulli (1/2) dithers. The decoder uses an MRC receiver combined with successive cancellation. We prove that in the limit of large L when L is increased exponentially with C*, the code is capacity achieving. We perform efficiency analyses when L is scaled linearly with C* and derive upper and lower bounds on the efficiency. We also show that the scheme has high efficiencies for practical ranges of C* using a low-rate good base code. We discuss the unknown time-varying behavior of the scheme and at the end briefly discuss the use of faster than Nyquist signaling to enable the scheme to have a high efficiency for higher C* values.
by Maryam Modir Shanechi.
S.M.
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Jin, Xin. "Parallel simulation of neural networks on SpiNNaker universal neuromorphic hardware." Thesis, University of Manchester, 2010. https://www.research.manchester.ac.uk/portal/en/theses/parallel-simulation-of-neural-networks-on-spinnaker-universal-neuromorphic-hardware(d6b8b72a-63c4-44ee-963a-ae349b0e379c).html.
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Artificial neural networks have shown great potential and have attracted much research interest. One problem faced when simulating such networks is speed. As the number of neurons increases, the time to simulate and train a network increases dramatically. This makes it difficult to simulate and train a large-scale network system without the support of a high-performance computer system. The solution we present is a "real" parallel system - using a parallel machine to simulate neural networks which are intrinsically parallel applications. SpiNNaker is a scalable massively-parallel computing system under development with the aim of building a general-purpose platform for the parallel simulation of large-scale neural systems. This research investigates how to model large-scale neural networks efficiently on such a parallel machine. While providing increased overall computational power, a parallel architecture introduces a new problem - the increased communication reduces the speedup gains. Modeling schemes, which take into account communication, processing, and storage requirements, are investigated to solve this problem. Since modeling schemes are application-dependent, two different types of neural network are examined - spiking neural networks with spike-time dependent plasticity, and the parallel distributed processing model with the backpropagation learning rule. Different modeling schemes are developed and evaluated for the two types of neural network. The research shows the feasibility of the approach as well as the performance of SpiNNaker as a general-purpose platform for the simulation of neural networks. The linear scalability shown in this architecture provides a path to the further development of parallel solutions for the simulation of extremely large-scale neural networks.
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Bajnoczki, Csongor. "Europe’s Parallel Media Universe: Cross-national analysis of populist media oppression in the EU." Wright State University / OhioLINK, 2018. http://rave.ohiolink.edu/etdc/view?acc_num=wright1527895414688351.
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Galluppi, Francesco. "Information representation on a universal neural Chip." Thesis, University of Manchester, 2013. https://www.research.manchester.ac.uk/portal/en/theses/information-representation-on-a-universal-neural-chip(77038a24-1f1e-4824-8725-4bd0d233626c).html.
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How can science possibly understand the organ through which the Universe knows itself? The scientific method can be used to study how electro-chemical signals represent information in the brain. However, modelling it by simulating its structures and functions is a computation- and communication-intensive task. Whilst supercomputers offer great computational power, brain-scale models are challenging in terms of communication overheads and power consumption. Dedicated neural hardware can be used to enhance simulation performance, but it is often optimised for specific models. While performance and flexibility are desirable simulation features, there is no perfect modelling platform, and the choice is subordinate to the specific research question being investigated. In this context SpiNNaker constitutes a novel parallel architecture, with communication and memory accesses optimised for spike-based computation, permitting simulation of large spiking neural networks in real time. To exploit SpiNNaker's performance and reconfigurability fully, a neural network model must be translated from its conceptual form into data structures for a parallel system. This thesis presents a flexible approach to distributing and mapping neural models onto SpiNNaker, within the constraints introduced by its specialised architecture. The conceptual map underlying this approach characterizes the interaction between the model and the system: during the build phase the model is placed on SpiNNaker; at runtime, placement information mediates communication with devices and instrumentation for data analysis. Integration within the computational neuroscience community is achieved by interfaces to two domain-specific languages: PyNN and Nengo. The real-time, event-driven nature of the SpiNNaker platform is explored using address-event representation sensors and robots, performing visual processing using a silicon retina, and navigation on a robotic platform based on a cortical, basal ganglia and hippocampal place cells model. The approach has been successfully exploited to run models on all iterations of SpiNNaker chips and development boards to date, and demonstrated live in workshops and conferences.
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Hopkins, Brian. "Modified ParaDex: Theory and hardware implementation of a 6-prismatic-spherical-universal parallel manipulator." Ohio : Ohio University, 2001. http://www.ohiolink.edu/etd/view.cgi?ohiou1173899557.
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Jayabalan, Arun. "Development of a Massively Parallel Coarse Grained Reconfigurable Fabric verification Environment using Universal Verification Methodology." Thesis, KTH, Skolan för informations- och kommunikationsteknik (ICT), 2016. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-206099.
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According to the International Roadmap for semiconductors (ITRS), there should be a 1000X improvement in performance with only 120% increase in the power budget and no increase in the design team size to deal with designs that are 10X more complex. One solution to cope with this complexity is to increase the granularity of the building blocks for developing new architectures. As a solution, Dynamically Reconfigurable Resource Array (DRRA) with Distributed Memory Architecture(DiMArch) was developed. As the design complexity increased, the need for verification became inevitable in the design flow. To include the feature of reusability, a reconfigurable verification environment is required to effectively verify the device under test (DUT) and also improve the productivity in the design cycle. The thesis work begins with the specification & design and also the verification plans for the DRRA and DiMArch. The major task of the thesis work is in developing a reconfigurable verification environment for the DRRA using Universal Verification Methodology (UVM) and a systemlevel verification test bench for the DiMArch . This thesis work also focuses on the possible power optimization in the design.
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McCaa, John Kimberly. "Fame, celebrity & mass media in the digital age| Daniel Boorstin's cultural decline, or passport to a parallel universe?" Thesis, The University of Texas at Dallas, 2015. http://pqdtopen.proquest.com/#viewpdf?dispub=3706639.
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An examination of the famous and celebrities within a country can offer a view to the values of its people. The Romans had Caesar, the Egyptians Cleopatra and in the early twentieth century Americans admired Charles Lindbergh. From each of them, scholars have learned something about the age in which they lived and the people of their time. Standards of beauty, behavior, and success have been gleaned by examining women and men held in the public spotlight. The historian Daniel Boorstin worried that that was changing in the United States by the twentieth century due to the growing influence of mass media. His 1961 book The Image: A Guide to Pseudo-Events in America warned that the country was straying from values that he believed made it great. Image and appearance, he warned, were replacing experience and achievement as most important in persons gaining public recognition. A proliferation of mass media manufactured "pseudo-events" was the cause he said, impacting not only who was recognized but the country's ideals. Boorstin labeled it a "cultural decline" that had started with the Graphic Revolution. Although changes in western society did take place and that change was revolutionary, this dissertation suggests a slow but steady "evolution" of the self was also underway and may be more descriptive of what was and is still occurring today. This study links industrialization, dramatic technological advances, and the conversion of American society from rural to urban dwellers to a transformation of the "self" that started as far back as the Reformation, as causes for the changes. That transformation sparked a slowly budding struggle over control of self-identity that continues to this day. A half century after Daniel Boorstin issued his warning, this dissertation explores not just the accuracy of his predictions but why and how many business and political interests and social elites still struggle to maintain some influence over how Americans perceive themselves through images, how concepts of fame and celebrity continue to evolve and why the scholarly conversation about mass media, culture and society generated by his original hypothesis may be more important to explore today than ever.
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Allsopp, Joseph. "Parallel Development of a Real-time Co-Simulation and MPC Control System for the Universal Water System." Thesis, Allsopp, Joseph (2018) Parallel Development of a Real-time Co-Simulation and MPC Control System for the Universal Water System. Honours thesis, Murdoch University, 2018. https://researchrepository.murdoch.edu.au/id/eprint/44812/.
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Model Predictive Control (MPC) has had great success within the process industry. With its optimising capabilities and ability to handle complex interactions, MPC helps reduce operating costs while increasing production rates. A comprehensive internal process model is a prerequisite for MPC and consequently the process must be disturbed extensively with test signals during development or following modifications. This project focuses on the development of a cooperative simulation (co-simulation) to facilitate the end to end design of an MPC control system to be ultimately used on its real-world counterpart.
Murdoch University’s Universal Water System (UWS) was used as the test case with Honeywell’s Profit Suite selected as the MPC software platform. Following the derivation of a process model from first principles and empirical data, offline and real-time simulations were developed in Matrix Laboratory (MATLAB) and connected to Profit Suite using an OLE for Process Control (OPC) server. The offline simulation was used to generate data for controller model identification and the real-time version was used to virtually commission the MPC controller and for operator training. Profit Stepper was used to recreate the controller’s internal model by applying test signals directly to the real-world process. Analysis of controller performance for both controller models and conventional feedback control indicated that even with an imperfect controller model, MPC performance was superior to Proportional and Integral control, particularly when control loop interaction and disturbances were prominent. However, it was noted that MPC performance did improve with model accuracy. The benefit of the simulated design approach is that the controller model can be created without having to disturb the plant but it is limited by the accuracy of the process model.
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Ritchie, Robert Peter. "Efficient Constructions for Deterministic Parallel Random Number Generators and Quantum Key Distribution." Miami University / OhioLINK, 2021. http://rave.ohiolink.edu/etdc/view?acc_num=miami1619099112895031.
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Gualtieri, Dan. "but we love you and we miss you and you should come to dinner." Bowling Green State University / OhioLINK, 2018. http://rave.ohiolink.edu/etdc/view?acc_num=bgsu1522319462153488.
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Horton, Brian (Saxophonist). "Tone Parallels in Music for Film: The Compositional Works of Terence Blanchard in the Diegetic Universe and a New Work for Studio Orchestra by Brian Horton." Thesis, University of North Texas, 2017. https://digital.library.unt.edu/ark:/67531/metadc1011761/.
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This research investigates the culturally programmatic symbolism of jazz music in film. I explore this concept through critical analysis of composer Terence Blanchard's original score for Malcolm X directed by Spike Lee (1992). I view Blanchard's music as representing a non-diegetic tone parallel that musically narrates several authentic characteristics of African-American life, culture, and the human condition as depicted in Lee's film. Blanchard's score embodies a broad spectrum of musical influences that reshape Hollywood's historically limited, and often misappropiated perceptions of jazz music within African-American culture. By combining stylistic traits of jazz and classical idioms, Blanchard reinvents the sonic soundscape in which musical expression and the black experience are represented on the big screen. My new work––Black Magic––is a musical response to the research found within this study. The through-composed piece is written in three movements for a studio orchestra. It is an homage to the musical, cultural, and entertainment contributions of African-Americans in the magical realm of Hollywood cinema.
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Tuma, Niemi Toivo. "When Braneworlds Collide." Thesis, Uppsala universitet, Teoretisk fysik, 2021. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-448725.
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This project is an investigation of a cosmological model consisting of a five dimensional AdS-vacuum with a flux. By discharges in the flux, four dimensional bubbles can nucleate in the vacuum and collide with each other while expanding. Our observable universe is considered to be localized on the membrane of such a bubble. The main purpose of the model was to find a possible explanation for dark energy and inflation. We compute the Friedmann equation for an expanding bubble, as well as analytical expressions for the two slow roll parameters ε and η related to slow roll inflation. We also show that there exists a set of parameters of the model where both slow roll parameters are small enough in order for inflation to last for at least 60 Hubble times. However, our model doesn’t survive all consistency checks with today’s observations. We conclude that even if the resulting slow roll parameters look promising, one has to either look harder for a set of ”good” fundamental parameters of the model, or further develop it to have a chance of surviving all consistency checks.Populärvetenskaplig sammanfattning: Det här projektet undersöker en kosmologisk modell bestående av ett femdimensionellt vakuum med negativ rumtidkrökning. I vakuumet finns ett elektriskt fält, som i högre dimensioner än fyra kallas flux (flöde). Urladdningar i detta flux gör det möjligt för fyrdimensionella bubblor att uppstå i vakuumet. Dessa vakuumbubblor expanderar snabbt och kommer så småningom att kollidera med varandra. Tanken är att vårt fyrdimensionella observerbara universum utgör en del av membranet på en av dessa expanderande vakuumbubblor. De andra vakuumbubblorna kan - om man vill - betraktas som parallella universum. Målet med detta projekt har varit att hitta en möjlig model för kosmisk inflation - epoken i vårt universums ungdom då rummet expanderade enormt snabbt under en väldigt kort tidsperiod. Inflationen i vår modell äger rum när vakuumbubblan för vårt universum kolliderar med andra vakuumbubblor. Vi lyckades visa att den här modellen kan ge upphov till inflation som varar tillräckligt länge för att det ska stämma överens med dagens observationer av vårt observerbara universum. Dock förutspår modellen även andra saker som inte stämmer överens med observationerna. Vår slutsats är att modellen ser lovande ut, men att man antingen behöver undersöka den noggrannare eller utveckla den på något sätt, om den ska ha en chans att stämma överens med universumet vi observerar.
Presentationen skedde över videolänk på grund av Covid-19.
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Salas, Leslie. "Mirrors and Vanities." Master's thesis, University of Central Florida, 2013. http://digital.library.ucf.edu/cdm/ref/collection/ETD/id/5697.
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Mirrors and Vanities is a multi-modal collection which showcases the diversity of working in long and short storytelling forms. Featured in this thesis are fiction, nonfiction, graphic narrative, and screenplay. Using unconventional approaches to storytelling in order to achieve emotional resonance with the audience while maintaining high standards for craft, these stories and essays explore the costs inherent to the subtle nuances of interpersonal relationships. The fiction focuses on the complications of characters keeping secrets. A husband discovers the truth behind his wife's miscarriage. A girl visits her fiance in purgatory. A boy crosses a line and loses his best friend. Meanwhile, the nonfiction centers on self-discovery and gender roles associated with power struggles. A schizophrenic threatens to ruin my mother's wedding. I rediscover my relationship with my father through food writing. Sword-work teaches me to fail and succeed at making martial art. The title work of the thesis is a collaged story highlighting the tribulations of a physicist fixated on recovering his lost love by manipulating the multiverse. The multi-modal format implicates the nebulosity of physics theories and how different aspects of the narrative can be presented in various formats to best suit the nature of the storytelling. Through the interactions of characters in mundane and extraordinary circumstances, the works in this thesis examine the consequences of choice, the contrast between reality and expectation, coming of age, and the Truth of narrative.M.F.A.
Masters
English
Arts and Humanities
Creative Writing
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Rossi, Elisabetta. "Unveiling the size of the Universe: the first accurate measurement of the Earth-Sun distance by Giovanni Domenico Cassini." Master's thesis, Alma Mater Studiorum - Università di Bologna, 2021. http://amslaurea.unibo.it/23751/.
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In the ambitious plan of King Louis XIV, France should have become culturally dominant in Europe. The First Minister of State Jean Baptiste Colbert suggested him to finance not only military campaigns but also scientific expeditions aimed to determine, with the highest possible accuracy, the extension of the colonial possessions, to show that France was the largest European power.
The astronomers of the Académie des Sciences (founded in 1666), being also geographers and cartographers, were the “leading actors” of those dangerous expeditions, as measuring the terrestrial coordinates (latitude and longitude) strongly required their skills: the desire for glory of the Roi Soleil had unexpectedly turned out into an improvement of astronomy.
All the expeditions were supervised by the Italian astronomer Giovanni Domenico Cassini (1625-1712) who had been warmly welcomed at the court of the Sun King, in 1669, and was living in the Observatoire Royal in Paris.
Cassini instructed the scientists who were chosen for the expeditions, checked their instruments and compiled a list of instructions concerning the observations they should have carried out.
Among the several expeditions organized by Cassini, the one to Cayenne (French Guiana) deserves particular attention as thanks to some observations carried out there (and simultaneously in Paris) Cassini obtained the first accurate measurement of the Earth-Sun distance.
Through a careful check and inspection of all the available original documents kept in the Archives in Paris, the history of the observations which were carried out in Cayenne, has been reconstructed and is presented in this work. Moreover, some almost unknown details concerning Cassini’s life and work are also shown.
The ambitious aim of this work is to make the reader go back in the past to perceive the atmosphere of an epoch in which, thanks also to the overseas expeditions, began to bloom what it was going to become the Age of Enlightenment.
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Koudella, Christophe. "Ondes internes de gravité en fluide stratifié: instabilités, turbulence et vorticité potentielle." Phd thesis, Ecole normale supérieure de lyon - ENS LYON, 1999. http://tel.archives-ouvertes.fr/tel-00005960.
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Une étude numérique de la dynamique d'ondes internes de gravité en fluide stablement stratifié est menée. On décrit un algorithme pseudo-spectralparallèle permettant d'intégrer les équations de Navier-Stokes sur une machine paralèele. En deux dimensions d'espace, on analyse la dynamique d'un
champ d'ondes internes propagatives, d'amplitude modérée et initialement plan et monochromatique. Le champ d'ondes est instable et déferle. Le déferlement produit une turbulence de petites échelles spatiales influencées par la stratification. L'étude
est étendue au cas tridimensionnel, plus réaliste. En trois dimensions, on étudie le même champ d'ondes internes, que l'on perturbe par un bruit infinitésimal ondulatoire tridimensionnel, mais on considère des ondes statiquement stables et
instables (grandes amplitudes). On montre que le déferlement d'une onde interne est un processus intrinsèquement tridimensionnel, y compris pour les ondes de faible amplitude. La tridimensionalisation du champ d'ondes s'opère dans les zones de l'espace où le champ de densité devient statiquement instable. L'effondrement gravitationnel d'une zone est de structure transverse au plan de propagation de l'onde. Les effets de la turbulence des petites échelles sur la production de la composante non propagatrice de l'écoulement, le mode de vorticité potentielle et la production d'un écoulement moyen, permet de conclure que seule une petite proportion de l'énergie mécanique initiale est convertie sous ses deux formes, la majeure partie étant dissipée par la dissipation visqueuse et conduction thermique. On reconsidère le mode de vorticiée potentielle par une approche Hamiltonienne non-canonique du fluide parfait stratifié. La dérivation d'un système de dynamique modifiée permet d'étudier la relaxation d'un écoulement stratifié, conservant sa vorticité potentielle et sa densité, vers un état stationnaire d'énergie minimale, correspondant au mode de vorticité potentielle.
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Kosowski, Adrian. "Time and Space-Efficient Algorithms for Mobile Agents in an Anonymous Network." Habilitation à diriger des recherches, Université Sciences et Technologies - Bordeaux I, 2013. http://tel.archives-ouvertes.fr/tel-00867765.
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Computing with mobile agents is rapidly becoming a topic of mainstream research in the theory of distributed computing. The main research questions undertaken in this study concern the feasibility of solving fundamental tasks in an anonymous network, subject to limitations on the resources available to the agent. The considered challenges include: exploring a graph by means of an agent with limited memory, discovery of the network topology, and attempting to meet with another agent in another network (rendezvous). The constraints imposed on the agent include the number of moves which the agent is allowed to perform in the network, the amount of state memory available to the agent, the ability of the agent to communicate with other agents, as well as its a priori knowledge of the network topology or of global parameters.
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Benjemaa, Mondher. "Etude et simulation numérique de la rupture dynamique des séismes par des méthodes d'éléments finis discontinus." Phd thesis, Université de Nice Sophia-Antipolis, 2007. http://tel.archives-ouvertes.fr/tel-00222870.
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Ce travail est dédié à l´étude et la simulation numérique de la rupture dynamique des séismes en deux et trois dimensions d´espace par une méthode d´éléments finis discontinus. Après avoir transformé le système de l´élastodynamique en un système hyperbolique symétrique du premier ordre, nous proposons un schéma numérique basé sur des flux centrés et un schéma explicite en temps de type saute-mouton. A travers l´étude d´une énergie discrète du système, nous spécifions les conditions aux limites sur la faille afin de prendre en compte de manière faible la rupture en mode cisaillant que nous traitons. Nous montrons, qu´en l´absence de tractions tangentielles sur la faille, cette énergie est parfaitement conservée. Nous illustrons la capacité de notre méthode à travers divers cas tests sur des configurations complexes grâce à une implémentation parallèle.
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Strugarek, Antoine. "Turbulence, transport et confinement : des tokamaks au magnétisme des étoiles." Phd thesis, Université Paris-Diderot - Paris VII, 2012. http://tel.archives-ouvertes.fr/tel-00765706.
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Cette thèse s'inscrit dans le contexte de l'étude de l'auto-organisation des plasmas chauds magnétisés. Nous nous intéressons en particulier aux deux objets que sont les étoiles et les tokamaks. Nous les étudions à l'aide de simulations numériques en utilisant des codes premiers principes dans le contexte des phénomènes de turbulence, de transport et de confinement dans les plasmas. La première partie de cette thèse s'attache à donner une introduction sur les caractéristiques des plasmas des étoiles et des tokamaks, ainsi que sur les raisons qui nous ont poussé à les étudier conjointement. Puis, nous développons en deuxième partie des travaux appliqués aux étoiles. A l'aide de simulations numériques, nous étudions pour la première fois en géométrie sphérique et en 3D l'interaction des mouvements turbulents avec un champ magnétique interne dans le Soleil, dans la région de la tachocline qui agit comme une barrière de transport du moment cinétique. Nous montrons qu'un tel champ magnétique ne peut expliquer l'épaisseur de la tachocline que nous observons, et donnons des pistes de réflexion pour comprendre cette épaisseur. Nous explorons également dans cette partie les implications que l'environnement d'une étoile (en particulier le vent de l'étoile, et les planètes gravitant autour) peut avoir sur son organisation interne. Cette étude nous permet aussi d'étudier l'interaction des vents stellaires avec les magnétosphères planétaires qui agissent comme des barrières de transport pour la matière. Des travaux spécifiques aux tokamaks sont ensuite présentés dans une troisième partie. Nous y développons une étude numérique des mécanismes expérimentaux conduisant à la création de barrières de transport dans les tokamaks. Ces barrières de transport permettent l'accès à des régimes de fusion nucléaire performants. Pour la première fois, nous montrons théoriquement comment déclencher la formation de ces barrières dans des simulations turbulentes de codes premiers principes. Enfin, la dernière partie présente les résultats des réflexions communes issue de cette thèse fai- sant le pont entre deux communautés scientifiques. L'utilisation d'une méthode spectrale originale pour l'analyse de phénomènes multi-échelles y est exposée. Elle est successivement développée puis appliquée pour mettre en évidence les mécanismes de saturation de la dynamo stellaire et de l'instabilité du gradient de température ionique dans les tokamaks. Un modèle unique traitant de l'interaction entre la turbulence et les écoulements de grande échelle est ensuite développé à la fois dans le contexte de la tachocline solaire et dans celui des tokamaks, formalisant l'analogie qui existe entre les deux objets de notre étude.
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Métivier, Ludovic. "Une méthode d'inversion non linéaire pour l'imagerie sismique haute résolution." Phd thesis, Université Paris-Nord - Paris XIII, 2009. http://tel.archives-ouvertes.fr/tel-00471293.
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Les développements récents de l'industrie pétrolière en matière d'exploration et de production, et la mise en place de techniques de séquestration souterraine du CO2, nécessitent des méthodes d'imagerie du sous-sol permettant d'obtenir une information structurale et quantitative à fine échelle. Les travaux présentés dans cette thèse s'intéressent au développement d'une telle méthode, permettant d'estimer la distribution d'impédance acoustique autour d'un puits. Elle s'inspire du problème 1D d'inversion de données sismiques de puits PSV (Profil Sismique Vertical), et en propose une extension multi-D. Cette généralisation se heurte à deux principaux problèmes. Le premier consiste en l'indétermination inhérente au problème inverse multi-D, combattue par l'introduction de termes de régularisation appropriés. Le second est l'importance des coûts de calcul nécessaires à la résolution de ce problème. Une méthode numérique adéquate est proposée, faisant intervenir une méthode d'optimisation couplant un algorithme de type Quasi-Newton et l'algorithme du gradient conjugué. De plus, un algorithme de décomposition de domaines permet le calcul distribué du gradient de la fonctionnelle par l'état adjoint. Les performances de cette nouvelle méthode d'imagerie sont évaluées dans un contexte d'implémentation 2D. D'autre part, la modélisation de la propagation des ondes acoustiques dans le sous-sol est réalisée à l'aide de couches absorbantes de type PML (Perfectly Matched Layers). Une étude mathématique de la stabilité des équations PML adaptées au contexte spécifique d'un milieu de propagation hétérogène est également menée.
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Roy, Fabrice. "Etude du système couplé Boltzmann sans collisions-Poisson pour la gravitation : simulations numériques de la formation des systèmes auto-gravitants." Phd thesis, Versailles-St Quentin en Yvelines, 2004. http://pastel.archives-ouvertes.fr/pastel-00002403.
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Nous étudions la formation et les propriétés des systèmes auto-gravitants à l'aide de simulations numériques à N corps d'effondrements gravitationnels. Nous effectuons dans un premier temps une synthèse des principaux résultats analytiques concernant les équations de Boltzmann sans collisions et de Poisson, qui modélisent les systèmes gravitationnels non collisionnels ainsi que certaines solutions analytiques de ce système couplé d'équations. Nous présentons ensuite les codes de calcul utilisés pour les simulations. Nous avons parallélisé certains de ces codes, nous introduisons donc le calcul parallèle et la bibliothèque d'échange de message MPI. Nous exposons enfin les résultats de nos simulations, et leurs analyses. Nous déduisons de ces analyses divers résultats pouvant expliquer différentes caractéristiques des systèmes auto-gravitants ainsi que les conditions initiales nécessaires au déclenchement des instabilités d'Antonov et d'orbites radiales.
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Ta, Quang Anh. "Modélisation des propriétés mécaniques anisotropes aléatoires et impacts sur la propagation des ondes élastiques." Phd thesis, Ecole Centrale Paris, 2011. http://tel.archives-ouvertes.fr/tel-00589052.
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L'objectif de ce travail de thèse est de prendre en compte à la fois l'hétérogénéité, l'anisotropie et des incertitudes dans la simulation 3D de la propagation d'ondes élastiques. Pour ce faire, dans un premier temps, on modélise le champ de propriétés mécaniques, ici le champ de tenseur d'élasticité, par un modèle de champ stochastique 3D des matrices définie-positives. La construction de ce modèle de champ est essentiellement fondée sur celle de Soize [2008]. Notre modèle conserve ainsi les propriétés principales du modèle de Soize comme le paramétrage minimal contrôlant l'amplitude de la fluctuation et la taille caractéristique de la variabilités patiale, le comportement local a priori arbitrairement anisotrope (anisotropie triclinique) et les propriétés mathématiques fondamentales. De plus, un nouveau paramètre est introduit dans ce modèle pour imposer un niveau d'anisotropie moyen souhaité. Dans un deuxième temps, on effectue des adaptations du code de calcul d'éléments finis spectraux, à savoir le code parallèle SPEC3D, afin d'une part de générer les réalisations du champ stochastique du tenseur d'élasticité et d'autre part de prendre en compte l'anisotropie dans la résolution numérique du problème élastodynamique. Des études paramétriques utilisant SPEC3D sont ensuite réalisées mettant en évidence les influences de l'anisotropie et des paramètres d'hétérogénéité sur la propagation d'ondes sismiques. En particulier, elles démontrent une dépendance directe entre la longueur de corrélation du champ de propriétés et le temps caractéristique d'apparition de la diffusion. Ce régime se manifeste par l'équipartition d'énergie entre les mouvements irrotationnels et rotationnels.
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Brossier, Romain. "Imagerie sismique à deux dimensions des milieux visco-élastiques par inversion des formes d'ondes : développements méthodologiques et applications." Phd thesis, Université de Nice Sophia-Antipolis, 2009. http://tel.archives-ouvertes.fr/tel-00451138.
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La connaissance des structures internes de la Terre, à différentes échelles, présente des enjeux majeurs d'ordres économiques, humains, environnementaux et scientifiques. Diverses méthodes d'imagerie ont été développées en utilisant les informations contenues dans les ondes sismiques. La méthode d'inversion des formes d'ondes construit des images quantitative haute résolution des paramètres physiques du sous-sol, en exploitant le champ d'onde complet, sous la forme d'un problème d'optimisation. Dans ce travail de thèse, je présente l'application de l'inversion des formes d'ondes en domaine fréquentiel, pour imager les paramètres visco-élastiques dans des géometries à deux dimensions à grands offsets. Dans un premier temps les développements méthodologiques et algorithmiques sont présentés. La modélisation de la propagation des ondes P-SV en domaine fréquentiel, le problème direct du processus d'imagerie, est assurée par une méthode d'éléments finis Galerkin discontinus, assurant une grande flexibilité dans le choix des ordres d'interpolation et dans l'utilisation de maillages triangulaires non-structurés. Le problème inverse est résolu sous une forme linéarisée, afin de limiter le nombre de simulations directes, et utilise l'algorithme quasi-Newton L-BFGS permettant de tirer bénéfice de l'estimation "économique" du Hessien. Le processus global d'imagerie est implémenté sous la forme d'un algorithme massivement parallèle destiné aux calculateurs modernes à mémoire distribuée. Dans un deuxième temps, les algorithmes développés sont appliqués à des cas d'étude. Des applications sont menées dans des modèles synthétiques réalistes représentatifs d'environnements terrestres et marins. Ces études montrent les difficultés associées à la reconstruction des paramètres élastiques à partir de données mettant en jeu des phénomènes de propagations complexes (ondes converties, multiples, ondes de surfaces...). Des solutions sont proposées sous forme de processus hiérarchiques multi-échelles, afin de limiter les effets des non-linéarités du problème inverse et ainsi d'améliorer la convergence du processus vers le minimum global. Enfin, la sensibilité de différentes normes et critères de minimisation est analysée, à partir de données bruités issues de modèles synthétiques réalistes, ainsi que sous l'approximation acoustique pour un jeu de données réelles pétrolière. Ces tests montrent certaines limites du formalisme classique basé sur la norme L2 dans l'espace des données, tandis que la norme L1 apparaît comme alternative robuste pour l'inversion de données décimées en domaine fréquentiel.
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Ta, Quang Anh. "Modélisation des propriétés mécaniques anisotropes aléatoires et impacts sur la propagation des ondes élastiques." Electronic Thesis or Diss., Châtenay-Malabry, Ecole centrale de Paris, 2011. http://www.theses.fr/2011ECAP0006.
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L’objectif de ce travail de thèse est de prendre en compte à la fois l’hétérogénéité, l’anisotropie et des incertitudes dans la simulation 3D de la propagation d’ondes élastiques. Pour ce faire, dans un premier temps, on modélise le champ de propriétés mécaniques, ici le champ de tenseur d’élasticité, par un modèle de champ stochastique 3D des matrices définie-positives. La construction de ce modèle de champ est essentiellement fondée sur celle de Soize [2008]. Notre modèle conserve ainsi les propriétés principales du modèle de Soize comme le paramétrage minimal contrôlant l’amplitude de la fluctuation et la taille caractéristique de la variabilités patiale, le comportement local a priori arbitrairement anisotrope (anisotropie triclinique) et les propriétés mathématiques fondamentales. De plus, un nouveau paramètre est introduit dans ce modèle pour imposer un niveau d’anisotropie moyen souhaité. Dans un deuxième temps, on effectue des adaptations du code de calcul d’éléments finis spectraux, à savoir le code parallèle SPEC3D, afin d’une part de générer les réalisations du champ stochastique du tenseur d’élasticité et d’autre part de prendre en compte l’anisotropie dans la résolution numérique du problème élastodynamique. Des études paramétriques utilisant SPEC3D sont ensuite réalisées mettant en évidence les influences de l’anisotropie et des paramètres d’hétérogénéité sur la propagation d’ondes sismiques. En particulier, elles démontrent une dépendance directe entre la longueur de corrélation du champ de propriétés et le temps caractéristique d’apparition de la diffusion. Ce régime se manifeste par l’équipartition d’énergie entre les mouvements irrotationnels et rotationnelsThe aim of this thesis is to take into account the heterogeneity, the anisotropy and the uncertainties within 3D numerical simulation of elastic waves propagation. Firstly, the elasticity tensor field is modeled by means of a stochastic tensor-valued field. Its construction is generalized from the model of Soize [2008]. Hence, our model preserves principle properties of the former : a small set of parameters controlling the whole dispersion and the characteristic size of spatial variability, a local behavior being a priori arbitrary anisotropic (triclinic anisotropy) andothers essential mathematical properties. Moreover, a new parameter is added in order to impose a desired anisotropy mean level. Secondly, we carry out adaptations of an existing spectral finite elements-based elastic waves simulation software, namely the SPEC3D parallel computing code. On the one hand a sample generator of the elasticity random field model is implemented and on the other hand anisotropic material behavior is introduced in the elastodynamic solver. Finally, numerical parametric studies are performed using SPEC3D highlighting influences of heterogeneity and anisotropy on elastic waves behavior. In particular, it is observed that the characteristic time beyond which a multiple scattering pattern can be approximated by a diffusion regime directly depends on the correlation length of elasticity tensor field model. This time is detected by an energy equipartition between rotational and irrotational movements
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Winder, Brian Geoffrey. "Achieving Complex Motion with Fundamental Components for Lamina Emergent Mechanisms." Diss., CLICK HERE for online access, 2008. http://contentdm.lib.byu.edu/ETD/image/etd2279.pdf.
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Chang, Kun-Che, and 張坤哲. "Parallel Universes and Pseudo-Knowledge: A Wuxia Narrative Research on Chang Da-Chun''s Novel Gang of The City State." Thesis, 2018. http://ndltd.ncl.edu.tw/handle/uasgvj.
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Wiswedel, Bernd [Verfasser]. "Lernen in parallelen Universen / vorgelegt von Bernd Wiswedel." 2009. http://d-nb.info/992510805/34.
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"Parallel field-induced universal conductance fluctuations in open quantum dots." Université catholique de Louvain, 2005. http://edoc.bib.ucl.ac.be:81/ETD-db/collection/available/BelnUcetd-03072005-122529/.
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CHUANG, KAI-CHIEH, and 莊凱傑. "Chinese Nationalism in a Parallel Universe – A Narrative Criticism of the 2015 Ma-Xi Meeting." Thesis, 2017. http://ndltd.ncl.edu.tw/handle/45exd5.
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碩士東吳大學
人權碩士學位學程
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Drawing on Walter Fisher’s Narrative Paradigm, this thesis aims to analyze Ma Ying-Jeou (馬英九) and Xi Jin-Ping’s (習近平) statements in the 2015 Ma-Xi Meeting (馬習會), in order to interpret the joint Chinese nationalism within their statements. On the basis of Fishers’ perspective, I regard both Ma and Xi’s statements as their rhetorical acts which intend to politically persuade the audience, citizens and voters. By writing narratives or telling ‘stories’, politicians emphasize on or even cover up certain facts, and embed their ideologies, policies and ideas into elements of the story such as characters, settings and plots. According to my analysis, both Ma and Xi’s statements present a joint Chinese nationalism and imagination. Their joint Chinese nationalism is very consistent and coherent on the level of narrative probability, but very incompatible and absurd on the level of narrative fidelity. In the context of contemporary Taiwan, which is very different from China, their joint Chinese nationalism is too far away from what Taiwanese people think and do, and has become a myth and even a joke within a parallel universe .
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Ngwenya, Themba M. A. "An investigation into the improvement in WCDMA system performance using multiuser detection and interference cancellation." Diss., 2004. http://hdl.handle.net/2263/25329.
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WCDMA is typically characterised as a system capable of providing mobile users with data rates up to 2 Mb/s and beyond. It has been termed an ultra high-speed, ultra high-capacity radio technology that will be able to carry a new range of fast, colourful media, such as colour graphics, video, animations, digital audio, Internet and e-mail that consumers will be able to access over their mobiles devices. This current study has researched on the various existing Multiuser detection (MUD) processes or proposals conducted by various research institutions around the world. It has identified the advantages that the past work offers, and it is these advantages that form the basis of the current research into the improvement techniques. The proposed Partial Parallel Pipelined Multiuser Detector (PPPMUD or P3MUD) has come about from two main flavours or directions of research. The first one seeks to promote the Soft Parallel Interference Cancellation technique as an effective bias mitigation technique. This bias occurring in the second stage decision statistics, exhibits a very harmful effect on system Bit Error Rate, (BER), particularly for large system loads. This current study goes further by carefully analysing the Soft Cancellation Factor, SCF behaviour to eventually derive and determine the optimum SCF value which exhibits positive characteristics when varied with the increasing system load (number of users). This optimum SCF value is called the universal SCF or SCFUNV, as it is theoretically supposed to perform favourably under various system loads. A favourable or acceptable performance would be characterised by low observed or measured BER during the system processing stages. A further enhancement to the operational performance of the SCFUNV algorithm is the SCFUNV Compensator, which is basically a compensation mechanism created by modelling the behaviour of the SCF values, and adjusts the SCFUNV depending on the system load, (number of simultaneous users). Thus, the SCFUNV is adaptively adjusted in order to perform acceptably under all load conditions. The second direction of research, as regards improvements in MUD techniques, involves the conventional Bit-Streaming, Pipelined Multiuser Detector. This came about due to the computational complexity as well as matrix inversions which affected earlier asynchronous multiuser detection techniques. This detector has a pipelined architecture which avoids multishot (block-based) detection and instead, processes the bits in a streaming fashion. The architecture consists of a matched filter followed by three stages of parallel interference cancellation, (PIC). This present study extends that research by outlining the advantages of incorporating the soft parallel interference cancellation technique, by way of the universal soft cancellation factor, (SCFUNV), into the conventional pipelined multiuser detector architecture to form the P3MUD architecture, which includes the compensator. The contributions of the proposed P3MUD system is that the observed BER output simulations are promising, with an observed overall decrease in the error rate for the P3MUD process, as compared to the conventional pipelined detection method. This decrease signifies an improvement offered by the proposed (P3MUD) algorithm. Further observed analysis indicates the possibility of decreasing the number of parallel interference cancellation stages from three to at least two, after the matched filter detection stage, without an observable change in system BER. Hence, the proposal of the two-stage P3MUD.Dissertation (MEng (Electronic))--University of Pretoria, 2006.
Electrical, Electronic and Computer Engineering
unrestricted
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Oluokun, Adedayo. "Tvorba závislostního korpusu pro jorubštinu s využitím paralelních dat." Master's thesis, 2018. http://www.nusl.cz/ntk/nusl-387891.
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The goal of this thesis is to create a dependency treebank for Yorùbá, a language with very little pre-existing machine-readable resources. The treebank follows the Universal Dependencies (UD) annotation standard, certain language-specific guidelines for Yorùbá were specified. Known techniques for porting resources from resource-rich languages were tested, in particular projection of annotation across parallel bilingual data. Manual annotation is not the main focus of this thesis; nevertheless, a small portion of the data was verified manually in order to evaluate the annotation quality. Also, a model was trained on the manual annotation using UDPipe.
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Nevanti, Kirsi. "In Real Life (Or Elsewhere) : om kreativa processer och parallella verkligheter i dokumentärfilm." Doctoral thesis, 2017. http://urn.kb.se/resolve?urn=urn:nbn:se:uniarts:diva-262.
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Reality isn’t what it appears to be. Contexts are not always clear and visible. People don’t always say what they really mean. And they don’t always mean what they say. When life is your stage manager, anything can happen. I often say, life is hard, my head is harder. Making documentaries is not for the faint-hearted.This PhD project explores creative processes and parallel realities in documentary film, and discusses and conceptualizes the artistic practice of documentary filmmaking. The project consists in part of artistic works and essays that are critical reflections on the creative process and how that process can be conceptualized. The cinematic centerpiece of the thesis is entitled Images and the Worlds of Being (2011–2016). Previous subprojects are A Shift Between Worlds (2013–2015) and an essay book entitled In Real Life (or Elsewhere) (2013). Between 2013 and 2017, more essays were written, some of them translated to English. All the Swedish essays are available in PDF format. All of the works in the PhD project explore creative processes and parallel realities in two different ways: A Shift Between Worlds (2013–2015) explores identity and parallel realities in the gendered world. These works are based on two workshops led by Diane Torr, “Man for a Day” and “Woman for a Day.” They resulted in several component works, including two video essays, two audio works and two large-format photographic works, the latter in collaboration with photographer Johan Bergmark, as well as a short commentary film entitled Diane Speaks Out (2016). Images and the Worlds of Being (2011–2016) – a VR Classic Style film – explores what happens when documentary images are shown on four screens forming the walls of a room. This work also focuses on the view through the camera lens through which the filmmaker meets the world, in a hypnotic tapestry of parallel realities in a tenderly portrayed, runaway present. A sort of logical reasoning about the illogic of our era, in search of elusive reality (to paraphrase Jean Baudrillard) – the presence in the act of seeing. An experiment in the forms of visual knowledge, outside the traditional display windows. Shooting location: The World.
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Micklethwait, Guy Roland. "Models of Time Travel: a comparative study using films." Phd thesis, 2012. http://hdl.handle.net/1885/9486.
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This research identifies the way the science of time travel is presented to the public through the medium of feature films, and discovers if this can be used to construct a comprehensive set of models about time travel and its consequences.
There is no universally accepted understanding of what constitutes the nature of time. Even though the fundamental laws of physics do not prohibit time travel, scientists and philosophers do not agree about what would happen if backwards time travel ever became a reality.
I identified models that scientists and philosophers have produced about the nature of time, time travel and other temporal phenomena. I then determined the model of time used in each of the 100 time travel films that I reviewed. I also used a verbal survey to elicit the personal models of time travel for each participant of three focus groups I conducted with members of the movie-going public. I compared these models of time with the personal models used by members of the movie-going public and synthesised them to develop a comprehensive set of 21 models of time. The "guyline" diagrams that I devised proved to be a very useful tool for analysing how the timelines of the time travellers behaved in each film.
My research has shown that an investigation of time travel in films can indeed be used to construct useful models of time based on the evidence of the 21 models that I developed. Furthermore, I showed that both my models of time travel and my guyline diagrams helped to structure conversations about time with members of the movie-going public. The findings of this thesis can be used by scientists, philosophers, filmmakers and the public to help them clarify our thinking about time travel, the nature of time, how it is communicated, and also in future research.
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BROM, Jiří. "Matematické metody a úlohy v astronomii." Master's thesis, 2016. http://www.nusl.cz/ntk/nusl-202658.
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The aim of this thesis is to create collections of examples for the subject Astronomy taught for students of pedagogical faculties, studying this discipline as a part of physics courses. Due to very different mathematical knowledge of students I have chosen typical and not much difficult examples oriented to several branches of astronomy. Each part of examples begins with a self-contained theoretical introduction. The difficulty rises gradually from trivial to more complicated examples. The examples are mainly focused on motions in radial gravitational fields.