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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.
171

Mission and spiritual mapping in Africa

Van der Meer, Erwin 11 1900 (has links)
Spiritual mapping is an emerging trend within Evangelicalism which is affecting Christian mission globally. Spiritual mapping maintains that Satan has assigned territorial demons to every geo-political unit in the world. Territorial demons hold the people in their locality in spiritual bondage to sin, false religion or other evils.Spiritual mapping is the practice of identifying these territorial demons in order to loosen the influence of these demons by means of strategic level spiritual warfare (SLSW). SLSW refers to the practice of 'territorial exorcism' through identificational repentance, prayer walks, proclamation and other means. Spiritual mapping can be appreciated for its focus on liberating people and societies from evil. However, spiritual mapping and its underlying theology is defective from a biblical, historical and contextual perspective and is potentially harmful for church and mission in Africa. Further missiological reflection on a spiritual warfare dimension in mission is necessary within the global hermeneutical community. / Christian Spirituality, Church History and Missiology / M.Th. (Missiology)
172

Growing Resilience through Interaction with Nature (GRIN)

Marselle, Melissa January 2013 (has links)
Well-being is fundamental for health. However, health and well-being are under threat by increased prevalence of depression and physical inactivity. Interaction with the natural environment may prevent these critical health issues, as research has shown that walking outdoors contributes to better well-being than walking indoors. The aim of this thesis was to investigate outdoor group walks as a potential public health intervention to enhance positive mental and emotional well-being, reduce stress, and foster resilience. This thesis evaluated Walking for Health, a national group walking programme in England using a nonexperimental, longitudinal design. Individuals who did (Group Walkers) and did not (Non-Group Walkers) take part in outdoor group walks completed two online questionnaires about their mental and emotional well-being, and covariates. To gain a broader understanding of how outdoor group walks may contribute to positive well-being, integrations were proposed between the Attention Restoration Theory and the psycho-evolutionary model, and the theories of coping and resilience. Findings show that Group Walkers had greater mental well-being and positive affect, and less negative affect, depression and perceived stress than Non-Group Walkers. Group walking had no affect on social well-being, connectedness to nature or resiliency. Outdoor group walk participation affected positive well-being through a decrease in perceived stress, and an increase in physical activity. Group Walkers demonstrated resilience against adversity on negative affect. No evidence of resilience from outdoor group walks was found for mental well-being, positive affect or depression. Group walks in farmland and green corridor environments may further boost mental well-being, and reduce negative affect and perceived stress, when compared to group walks in the urban environment. This research suggests that outdoor group walks are effective at improving mental and emotional well-being, and could be a useful public health intervention to reduce stress and foster resilience. Implications for theory are discussed.
173

A NEAR LAUNCH FLIGHT SAFETY SYSTEM UTILIZING TELEMETRY SIGNAL RADIO INTERFEROMETRY

Winstead, Michael L., Saenz, Karen J. 10 1900 (has links)
International Telemetering Conference Proceedings / October 27-30, 1997 / Riviera Hotel and Convention Center, Las Vegas, Nevada / Flight Safety concerns increase proportionally with increasing missile performance. These concerns are greatest in the near launch arena where a missile has the greatest potential energy. Systems such as radar, GPS tracking systems, and optics are normally of limited use in this arena for a number of reasons. A system was required that would provide useful tracking data in the first few seconds of a missile launch. This system has met that requirement providing nominal path deviation data from the launcher out to as much as 120 seconds. The tracking system described herein uses the principle of radio interferometry to derive phase difference measurements between carefully spaced antennas. These measurements are transmitted to the Operational Display Facility and converted to a usable angular deviation plot for use by Flight Safety Personnel. This paper provides an elementary radio interferometer system background and discusses this particular system setup and use. Some detail is provided on the premission simulation and setup of the system as well as the real-time display setup and output of the final data product.
174

Decentralized network control, optimization and random walks on networks / Contrôle de réseau décentralisé, optimisation et marches aléatoires sur réseaux

De Bacco, Caterina 08 September 2015 (has links)
Dans les dernières années, plusieurs problèmes ont été étudiés à l'interface entre la physique statistique et l'informatique. La raison étant que, souvent, ces problèmes peuvent être réinterprétés dans le langage de la physique des systèmes désordonnés, où un grand nombre de variables interagit à travers champs locales qui dépendent de l'état du quartier environnant. Parmi les nombreuses applications de l'optimisation combinatoire le routage optimal sur les réseaux de communication est l'objet de la première partie de la thèse. Nous allons exploiter la méthode de la cavité pour formuler des algorithmes efficaces de type ‘’message-passing’’ et donc résoudre plusieurs variantes du problème grâce à sa mise en œuvre numérique. Dans un deuxième temps, nous allons décrire un modèle pour approcher la version dynamique de la méthode de la cavité, ce qui permet de diminuer la complexité du problème de l'exponentielle de polynôme dans le temps. Ceci sera obtenu en utilisant le formalisme de ‘’Matrix Product State’’ de la mécanique quantique.Un autre sujet qui a suscité beaucoup d'intérêt en physique statistique de processus dynamiques est la marche aléatoire sur les réseaux. La théorie a été développée depuis de nombreuses années dans le cas que la topologie dessous est un réseau de dimension d. Au contraire le cas des réseaux aléatoires a été abordé que dans la dernière décennie, laissant de nombreuses questions encore ouvertes pour obtenir des réponses. Démêler plusieurs aspects de ce thème fera l'objet de la deuxième partie de la thèse. En particulier, nous allons étudier le nombre moyen de sites distincts visités au cours d'une marche aléatoire et caractériser son comportement en fonction de la topologie du graphe. Enfin, nous allons aborder les événements rares statistiques associées aux marches aléatoires sur les réseaux en utilisant le ‘’Large deviations formalism’’. Deux types de transitions de phase dynamiques vont se poser à partir de simulations numériques. Nous allons conclure décrivant les principaux résultats d'une œuvre indépendante développée dans le cadre de la physique hors de l'équilibre. Un système résoluble en deux particules browniens entouré par un bain thermique sera étudiée fournissant des détails sur une interaction à médiation par du bain résultant de la présence du bain. / In the last years several problems been studied at the interface between statistical physics and computer science. The reason being that often these problems can be reinterpreted in the language of physics of disordered systems, where a big number of variables interacts through local fields dependent on the state of the surrounding neighborhood. Among the numerous applications of combinatorial optimisation the optimal routing on communication networks is the subject of the first part of the thesis. We will exploit the cavity method to formulate efficient algorithms of type message-passing and thus solve several variants of the problem through its numerical implementation. At a second stage, we will describe a model to approximate the dynamic version of the cavity method, which allows to decrease the complexity of the problem from exponential to polynomial in time. This will be obtained by using the Matrix Product State formalism of quantum mechanics. Another topic that has attracted much interest in statistical physics of dynamic processes is the random walk on networks. The theory has been developed since many years in the case the underneath topology is a d-dimensional lattice. On the contrary the case of random networks has been tackled only in the past decade, leaving many questions still open for answers. Unravelling several aspects of this topic will be the subject of the second part of the thesis. In particular we will study the average number of distinct sites visited during a random walk and characterize its behaviour as a function of the graph topology. Finally, we will address the rare events statistics associated to random walks on networks by using the large-deviations formalism. Two types of dynamic phase transitions will arise from numerical simulations, unveiling important aspects of these problems. We will conclude outlining the main results of an independent work developed in the context of out-of-equilibrium physics. A solvable system made of two Brownian particles surrounded by a thermal bath will be studied providing details about a bath-mediated interaction arising for the presence of the bath.
175

Marches quantiques ouvertes / Open quantum walks

Bringuier, Hugo 13 June 2018 (has links)
Cette thèse est consacrée à l'étude de modèles stochastiques associés aux systèmes quantiques ouverts. Plus particulièrement, nous étudions les marches quantiques ouvertes qui sont les analogues quantiques des marches aléatoires classiques. La première partie consiste en une présentation générale des marches quantiques ouvertes. Nous présentons les outils mathématiques nécessaires afin d'étudier les systèmes quantiques ouverts, puis nous exposons les modèles discrets et continus des marches quantiques ouvertes. Ces marches sont respectivement régies par des canaux quantiques et des opérateurs de Lindblad. Les trajectoires quantiques associées sont quant à elles données par des chaînes de Markov et des équations différentielles stochastiques avec sauts. La première partie s'achève avec la présentation de quelques pistes de recherche qui sont le problème de Dirichlet pour les marches quantiques ouvertes et les théorèmes asymptotiques pour les mesures quantiques non destructives. La seconde partie rassemble les articles rédigés durant cette thèse. Ces articles traîtent les sujets associés à l'irréductibilité, à la dualité récurrence-transience, au théorème central limite et au principe de grandes déviations pour les marches quantiques ouvertes à temps continu. / This thesis is devoted to the study of stochastic models derived from open quantum systems. In particular, this work deals with open quantum walks that are the quantum analogues of classical random walks. The first part consists in giving a general presentation of open quantum walks. The mathematical tools necessary to study open quan- tum systems are presented, then the discrete and continuous time models of open quantum walks are exposed. These walks are respectively governed by quantum channels and Lindblad operators. The associated quantum trajectories are given by Markov chains and stochastic differential equations with jumps. The first part concludes with discussions over some of the research topics such as the Dirichlet problem for open quantum walks and the asymptotic theorems for quantum non demolition measurements. The second part collects the articles written within the framework of this thesis. These papers deal with the topics associated to the irreducibility, the recurrence-transience duality, the central limit theorem and the large deviations principle for continuous time open quantum walks.
176

Análise, simulações e aplicações algorítmicas de caminhadas quânticas / Analysis, simulations and algorithmic applications of quantum walks

Marquezino, Franklin de Lima 26 February 2010 (has links)
Made available in DSpace on 2015-03-04T18:51:17Z (GMT). No. of bitstreams: 1 thesisMarquezino.pdf: 1984026 bytes, checksum: aab2f346b43ad780233318adb7219d76 (MD5) Previous issue date: 2010-02-26 / Conselho Nacional de Desenvolvimento Cientifico e Tecnologico / Quantum computing is a model of computation based on the laws of quantum mechanics, which can be used to develop faster algorithms. The development of efficient quantum algorithms, however, is a highly challenging task. A recent successful approach is the use of quantum walks. In this work, we have studied the quantum walk on the hypercube, obtaining the exact stationary distribution and analyzing properties of its mixing time both in the ideal and in the noisy set-ups, with noise generated by broken links. We have also studied the walk in a two-dimensional grid, where we have obtained its stationary distribution analytically and have explored the relation between mixing time and the complexity of the search algorithm for this graph. We have developed a computational tool for numerical simulation of quantum walks in one- and two-dimensional grids with several boundary conditions. Finally, we have studied some algorithms for search on graphs and have numerically analyzed the impact of decoherence over their performances. / A computação quântica é um modelo computacional baseado nas leis da mecânica quântica, que pode ser utilizado para desenvolver algoritmos mais eficientes que seus correspondentes clássicos. O desenvolvimento de algoritmos quânticos eficientes, no entanto, é uma tarefa altamente desafiadora. Uma abordagem recente que vem se mostrando bem-sucedida é a utilização de caminhadas quânticas. Neste trabalho, estudamos a caminhada quântica no hipercubo, calculando analiticamente sua distribuição estacionária e analisando propriedades de seu mixing time, tanto na situação ideal como na situação com descoerência gerada por ligações interrompidas. Também estudamos a caminhada na malha bidimensional, calculando sua distribuição estacionária analiticamente e explorando a relação entre o mixing time e a complexidade do algoritmo de busca nesse grafo. Desenvolvemos uma ferramenta computacional para simulação numérica de caminhadas quânticas em malhas uni- e bidimensionais com diversas condições de contorno. Finalmente, estudamos alguns algoritmos de busca em grafos e analisamos numericamente o impacto que a descoerência exerce sobre seus desempenhos.
177

Otimização de funções contínuas usando algoritmos quânticos / Quantum continuous function optimization algorithms

Lara, Pedro Carlos da Silva 22 April 2015 (has links)
Submitted by Maria Cristina (library@lncc.br) on 2015-09-23T18:31:34Z No. of bitstreams: 1 tese_pedro.pdf: 954527 bytes, checksum: e9834fab8c799933912f185f0a422658 (MD5) / Approved for entry into archive by Maria Cristina (library@lncc.br) on 2015-09-23T18:31:58Z (GMT) No. of bitstreams: 1 tese_pedro.pdf: 954527 bytes, checksum: e9834fab8c799933912f185f0a422658 (MD5) / Made available in DSpace on 2015-09-23T18:32:21Z (GMT). No. of bitstreams: 1 tese_pedro.pdf: 954527 bytes, checksum: e9834fab8c799933912f185f0a422658 (MD5) Previous issue date: 2015-04-22 / Conselho Nacional de Desenvolvimento Científico e Tecnológico / Optimization algorithms are known to have a wide range of applications in various areas of knowledge. Thus, any improvement in the performance of optimization algorithms generate great impact in solving various problems. Thus, this work indroduces the area of quantum algorithms for global optimization (maximization/minimization) of continuous functions through different quantum search methods and classical local optimization algorithms. In this case, the use of search quantum algorithms is tied directly to performance with respect to the classical method: using a quantum computer can find an element in an unsorted database using only $O(\sqrt{N})$ queries. / Algoritmos de otimização são conhecidos por apresentarem uma vasta gama de aplicações em diversas áreas do conhecimento. Desta forma, qualquer melhoria no desempenho dos algoritmos de otimização gera grande impacto na resolução de diversos problemas. Neste sentido, este trabalho introduz a área de algoritmos quânticos para a otimização global (maximização/minimização) de funções contínuas através de diferentes métodos quânticos de busca e algoritmos clássicos de otimização local. Neste caso, a utilização de algoritmos quânticos de busca está diretamente associada ao desempenho com relação ao método clássico: usando um computador quântico pode-se encontrar um elemento em um banco de dados não-ordenado usando apenas $O(\sqrt{N})$ consultas.
178

Application des marches aleatoires a l'etude des sous-groupes des groupes lineaires / Application of random walks to the study of subgroups of linear groups

Aoun, Richard 27 May 2011 (has links)
Dans cette thèse, nous utilisons et contribuons à la théorie des produits de matrices aléatoires afin d'étudier des propriétés génériques des éléments et des sous-groupes des groupes linéaires. Notre premier résultat donne une version probabiliste de l'alternative de Tits : nous montrons que si M_n et M'_n sont deux marches aléatoires indépendantes sur un groupe linéaire de type fini non virtuellement résoluble alors presque sûrement les deux marches finiront par engendrer un sous-groupe libre non abélien à deux générateurs. Cela répond par l'affirmative à une question de Guivarc'h et de Gilman, Miasnikov et Osin. Plus précisément, nous montrons que la probabilité que M_n et M'_n n'engendrent pas un sous-groupe libre décroit exponentiellement vite vers zéro. Notre outil principal est la théorie des produits de matrices aléatoires. Durant la preuve, nous établissons de nouveaux théorèmes limites dans cette théorie, d'une part en généralisant des résultats connus dans le cadre des produits de matrices à valeurs dans les corps archimédiens à tout corps local, d'autre part en donnant des résultats qui sont nouveaux même sur R. Par exemple, nous montrons que sous des hypothèses naturelles sur la marche aléatoire, les composantes suivant K de M_n dans la décomposition KAK deviennent asymptotiquement indépendantes avec vitesse exponentielle. Dans la deuxième partie de la thèse, nous utilisons ces résultats pour étudier la transience des sous-variétés des groupes algébriques. Un de nos résultats peut être formulé comme suit: soient H un sous-groupe non élémentaire de SL_2(R), une probabilité adaptée sur H ayant un moment exponentiel, alors pour toute sous-variété algébrique propre V de SL_2(R), la probabilité que la marche aléatoire appartienne à V décroit exponentiellement vite vers zéro. Par conséquent, la sous-variété algébrique V est transiente pour la marche aléatoire. Nous généralisons cet énoncé au cas ou la marche aléatoire est adaptée sur un groupe Zariski dense des points réels d'un groupe algébrique défini et déployé sur R. Ces résultats sont à comparer avec des travaux récents de Kowalski et de Rivin. / In this thesis, we use and contribute to the theory of random matrix products in order to study generic properties of elements and subgroups of linear groups. Our first result gives a probabilistic version of the Tits alternative : we show that two independent random walks M_n and M'_n on a non virtually solvable finitely generated linear group will eventually generate a non abelian free subgroup. This answers a question of Guivarc'h and Gilman, Miasnikov and Osin. We show in fact that the probability that M_n and M'_n do not generate a free subgroup decreases exponentially fast to zero. Our methods rely deeply on random matrix products theory. During the proof we give some new limit theorems concerning this theory, some of them will be the generalization of known results for matrices taking value in archimedean fields to arbitrary local fields, others will be new even over R. For example, we show that under natural assumptions on the random walk, the K-parts of M_n in the KAK decomposition become asymptotically independent with exponential speed. Next, we use these properties to study the transience of algebraic subvarieties in algebraic groups. One of our results can be formulated as follows: let H be a non elementary subgroup of SL_2(R), a probability measure with an exponential moment whose support generates H, then for every proper algebraic subvariety V of SL_2(R), the probability that the random walk lies in V decreases exponentially fast to zero. This shows that every proper algebraic subvariety is transient for the random walk. We generalize this result to the case where the support of the probability measure generates a Zariski dense subgroup of the real points of an algebraic group defined and split over R. These results share common flavor with recent works of Kowalski and Rivin
179

Generalizations of Szego Limit Theorem : Higher Order Terms and Discontinuous Symbols

Gioev, Dimitri January 2001 (has links)
No description available.
180

Tryggheten på Brynäs - en uppföljning av Gävle kommuns trygghetsvandring

Forslund, Ida January 2010 (has links)
Studien var en uppföljning av en trygghetsvandring i stadsdelen Brynäs i Gävle som gjordes 2008 med medverkan av boende i stadsdelen och tjänstemän från kommunen. Syftet med denna undersökning var att ta reda på hur de boende uppfattar trygghet i stadsmiljö utifrån sig själva och med avseende på vissa i förväg formulerade punkter. Syftet var också att utvärdera hur boende i stadsdelen Brynäs uppfattar tryggheten i området efter de förändringar som Gävle kommun gjort i den byggda miljön. Resultaten visade att det viktigaste för tryggheten var generellt att ha kontroll på och överblick över vad som händer runtomkring en. Denna känsla kunde minska eller öka genom olika faktorer i den byggda miljön. Med tanke på detta kändes öppna platser tryggare än trånga och belysning ökade tryggheten till viss del. Det var också viktigt är att området kändes välskött och att det fanns mycket folk runtomkring en. Trafiksituationen på Brynäs uppfattades som väldigt otrygg. Angående oskötta miljöer kom diskussionerna ofta in på socialt utsatta miljöer och människor i sådana miljöer, som upplevdes som brottsbenägna. Människor som vistades i stadsmiljö var minst lika viktiga som miljöerna – miljöerna var ett medel för att dölja eller avslöja dessa människor.Resultaten visade också att informanterna till största delen inte märkt de förändringar som Gävle kommun genomfört. / This study was a follow up on a project on satefy in Brynäs, performed by the community of Gävle. The aim of the study was to investigate the perceptions of safety in Brynäs by the people living there, from the persons´ spontaneous points of view and from certain subjects already specified from present research. The aim of the study was also to examine how people on Brynäs percieve some interventions in the built urban environment in Brynäs that the community of Gävle made between 2008 and 2010. The results showed that the most important factors that make the environment feel safe was that it should give people an overview of the surroundings. The informants said that overview of the surroundings made them feel in control of what happens around them. The informants thought a lot about areas with low socioeconomic status and the people living there as correlated with increaesed risks of crime. The people appearing in urban environments were as important for the perceptions of safety as the environments themselves – the environment could hide or show people able to comitting crimes to other people. The informants had mostly not noticed the interventions in the built environment made by the community of Gävle.

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