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251	Movimentos sob atração focal em campos vetoriais planares / Motions under focal attraction in planar vector fields MARTINS, Tiberio Bittencourt de Oliveira 29 August 2008 (has links) Made available in DSpace on 2014-07-29T16:02:23Z (GMT). No. of bitstreams: 1 Dissertacao Tiberio Bittencourt.pdf: 638703 bytes, checksum: b4eef7616f38b5efeb40a4c5c26e0b75 (MD5) Previous issue date: 2008-08-29 / In this work, we develop the article On the motion under focal attraction in a rotating medium , of J. Sotomayor, which deals with a bidimensional differential system that model the following Biological problem: in a shallow recipient with circular section, with liquid in, spinning with angular speed ω, there are platyhelminthes, flatworms organisms, they are attracted by a fix lighting point near of the border of the recipient and they swim with a speed v in the direction of the this point. The problem is to show that there exists an equilibrium point where platyhelminthes go to cluster by the time passing. It s analyzed the dynamic of the model: existence of critical points and stability of the system and bifurcations. We analyzed three modifications of this system too. In the last part, it s discussed a criterium for non existence of periodic orbits of a planar vector fields in a simply connected region. / Neste trabalho, desenvolvemos o artigo On the motion under focal attraction in a rotating medium de J. Sotomayor [9] que trata de um sistema de equações diferenciais bidimensional que modela o seguinte problema na Biologia: num recipiente raso de seção circular, com líquido, girando a uma velocidade angular ω, existem platelmintos, organismos vermiforme, eles s ao atra´ıdos por um ponto luminoso fixo perto da borda do recipiente e nadam com uma velocidade v em direçãoa este ponto. O problema é mostrar que existe um ponto de equilíbrio onde os platelmintos vão se aglomerar com o passar do tempo. É analisada a dinâmica da modelagem: existência de pontos de equilibrio e estabilidade do sistema e bifurcaçoes. Analisamos tambem tres modificaçoes desse sistema. Na parte final, e discutido um criterio para determinaçao da ausencia de orbitas periodicas em campos vetoriais planares. Campos vetoriais planares Biologia Equações diferenciais bidimencionais Dinâmica de modelagem Platelmintos
252	Bank Customer Churn Prediction : A comparison between classification and evaluation methods Tandan, Isabelle, Goteman, Erika January 2020 (has links) This study aims to assess which supervised statistical learning method; random forest, logistic regression or K-nearest neighbor, that is the best at predicting banks customer churn. Additionally, the study evaluates which cross-validation set approach; k-Fold cross-validation or leave-one-out cross-validation that yields the most reliable results. Predicting customer churn has increased in popularity since new technology, regulation and changed demand has led to an increase in competition for banks. Thus, with greater reason, banks acknowledge the importance of maintaining their customer base. The findings of this study are that unrestricted random forest model estimated using k-Fold is to prefer out of performance measurements, computational efficiency and a theoretical point of view. Albeit, k-Fold cross-validation and leave-one-out cross-validation yield similar results, k-Fold cross-validation is to prefer due to computational advantages. For future research, methods that generate models with both good interpretability and high predictability would be beneficial. In order to combine the knowledge of which customers end their engagement as well as understanding why. Moreover, interesting future research would be to analyze at which dataset size leave-one-out cross-validation and k-Fold cross-validation yield the same results. machine learning cross-validation k-fold leave-one-out random forest decision trees k-nearest neighbor logistic regression supervised learning supervised statistical learning binary classification customer churn bank customer churn. Probability Theory and Statistics Sannolikhetsteori och statistik
253	Automatic Flight Maneuver Identification Using Machine Learning Methods Bodin, Camilla January 2020 (has links) This thesis proposes a general approach to solve the offline flight-maneuver identification problem using machine learning methods. The purpose of the study was to provide means for the aircraft professionals at the flight test and verification department of Saab Aeronautics to automate the procedure of analyzing flight test data. The suggested approach succeeded in generating binary classifiers and multiclass classifiers that identified six flight maneuvers of different complexity from real flight test data. The binary classifiers solved the problem of identifying one maneuver from flight test data at a time, while the multiclass classifiers solved the problem of identifying several maneuvers from flight test data simultaneously. To achieve these results, the difficulties that this time series classification problem entailed were simplified by using different strategies. One strategy was to develop a maneuver extraction algorithm that used handcrafted rules. Another strategy was to represent the time series data by statistical measures. There was also an issue of an imbalanced dataset, where one class far outweighed others in number of samples. This was solved by using a modified oversampling method on the dataset that was used for training. Logistic Regression, Support Vector Machines with both linear and nonlinear kernels, and Artifical Neural Networks were explored, where the hyperparameters for each machine learning algorithm were chosen during model estimation by 4-fold cross-validation and solving an optimization problem based on important performance metrics. A feature selection algorithm was also used during model estimation to evaluate how the performance changes depending on how many features were used. The machine learning models were then evaluated on test data consisting of 24 flight tests. The results given by the test data set showed that the simplifications done were reasonable, but the maneuver extraction algorithm could sometimes fail. Some maneuvers were easier to identify than others and the linear machine learning models resulted in a poor fit to the more complex classes. In conclusion, both binary classifiers and multiclass classifiers could be used to solve the flight maneuver identification problem, and solving a hyperparameter optimization problem boosted the performance of the finalized models. Nonlinear classifiers performed the best on average across all explored maneuvers. Flight Aircraft Machine Learning Flight Dynamics Classification Supervised Learning Support Vector Machines Neural Networks Logistic Regression Feature Selection Recursive Feature Elimination Feature Representation k-fold cross-validation maneuvers flight maneuvers Control Engineering Reglerteknik
254	The Dynamics of Twisted Tent Maps Chamblee, Stephen Joseph 12 July 2013 (has links) Indiana University-Purdue University Indianapolis (IUPUI) / This paper is a study of the dynamics of a new family of maps from the complex plane to itself, which we call twisted tent maps. A twisted tent map is a complex generalization of a real tent map. The action of this map can be visualized as the complex scaling of the plane followed by folding the plane once. Most of the time, scaling by a complex number will \twist" the plane, hence the name. The "folding" both breaks analyticity (and even smoothness) and leads to interesting dynamics ranging from easily understood and highly geometric behavior to chaotic behavior and fractals. twisted tent map complex dynamical system dynamics fractal coded-coloring escape-time fold folding reflect filled-in Julia set twisted tent map TTM complex plane polygon Fractals Julia sets Symbolic dynamics Twist mappings (Mathematics) Chaotic behavior in systems
255	"An Hungry Man Dreameth": Transcendental Film Theory and Stylistic Trends in Recent Institutional Films of the LDS Church Lewis, Mark T. 01 May 2016 (has links) To the religiously minded, few things carry greater importance than a connection to the divine. For centuries, the literature of prophets and the work of gifted artists have served to create a liminal space where man and Maker can meet. The advent of cinema and the creation of the Internet pose unique questions for the artist seeking to lead an audience toward an encounter with God. In a modern world where discretionary time is dominated by on-demand video streaming, the value of understanding cinema and its myriad potential is particularly relevant. As a religious organization, The Church of Jesus Christ of Latter-day Saints has eagerly (and to a certain extent, uniquely) embraced and used film to further its aims. This thesis will further the conversation already begun on the topic of spirituality in official LDS Church productions, particularly adding new analysis regarding the form and content of more recent institutionally produced films. How do stylistic trends in recent official film productions of the LDS Church relate to the broader academic and theological discussion regarding cinematic spirituality? After the introduction and thesis overview in Chapter 1, Chapter 2 will provide a survey of prominent works regarding cinematic spirituality. Theories that entertain how movies speak to human spirits are varied and highly subjective. Many theories about what makes a work "spiritual" grow from particular religious traditions and are informed by that theorist's beliefs about God's nature. Some theories are dependent on loosely measured criteria (editing pace, complexity of music, distance between camera and subject, etc.), while others rely almost entirely on the "feeling" a work conveys (which may or may not be determined by objectively measurable parts).Chapter 3 relates the prominent theories laid out in Chapter 2 to the cinematic efforts made by The Church of Jesus Christ of Latter-day Saints in the past two decades. Examining the form and content of these media projects will reveal trends that indicate inherent assumptions on the part of the LDS Church's media department regarding the purpose and potential of spirituality and film. Chapter 4 explores how the Church's typical approach compares and contrasts with films made by independent Latter-day Saint filmmakers. Some stylistic possibilities will be derived from the efforts of Mormon artists more generally and may have implications for how Latter-day Saint films could help spiritually engage audiences. Mormon cinema LDS Church media Mormon Messages I'm a Mormon Mormon film the Life of Jesus Christ Bible Videos Joseph Smith: Prophet of the Restoration Meet the Mormons Spirituality and film cinematic transcendence Paul Schrader Craig Detweiler Dean Duncan Religion
256	Continuity and event in Leibniz and Deleuze Movahedi Pour, Hamed 06 1900 (has links) La continuité a un statut compliqué pour Deleuze et Leibniz. Chez Leibniz, la continuité est omniprésente dans ses mathématiques et sa métaphysique, mais il est aussi le théoricien de l'individualité absolue des monades, qui peuvent être interprétées comme des discontinuités irréductibles. Chez Deleuze, le champ Idéal est parfois considéré comme une continuité, mais il se caractérise aussi par une affirmation de divergence (et d'incompossibilité), qui pourrait impliquer une sorte de discontinuité dans l'ordre virtuel. Cette étude aborde ce problème chez les deux penseurs et révèle le rôle de la continuité dans leur métaphysique. En effet, un concept deleuzien de continuité est reconstitué en explorant Le pli, Différence et répétition, et Logique du sens. Il est montré comment la continuité (chez les deux penseurs), en tant que concept mathématique, se transforme en une notion métaphysique indispensable à la philosophie de l'événement de Deleuze. Cette recherche développe les nuances conceptuelles d'une notion deleuzienne de continuité et identifie ses différents types, à savoir la continuité divergente, la continuité intensive, la continuité torsionnelle et la continuité ten(or)sionnelle. Cette analyse permet de mettre au premier plan la correspondance architectonique de la métaphysique de Deleuze dans ces trois livres, une architecture empreinte de continuité et de pli. / Continuity has a complicated status for Deleuze and Leibniz. For Leibniz, continuity is prevalent in his mathematics and metaphysics, but he is also known to be the theoretician of the absolute individuality of monads, which can be interpreted as irreducible discontinuities. For Deleuze, the Ideal field is sometimes regarded as continuity, but it is also characterized by an affirmation of divergence (and incompossibility), which might imply a kind of discontinuity in the virtual order. This study engages with this problem in both thinkers and discloses the role of continuity in their metaphysics. Indeed, a Deleuzian concept of continuity is reconstituted while exploring The Fold, Difference and Repetition, and Logic of Sense. It is shown how continuity (in both thinkers), as a mathematical concept, turns into a metaphysical notion that is indispensable for Deleuze’s philosophy of event. This research unfolds the conceptual nuances of a Deleuzian notion of continuity and identifies its different types, namely, divergent continuity, intensive continuity, torsional continuity, and ten(or)sional continuity. This analysis allows us to foreground the architectonic correspondence of Deleuze's metaphysics in these three books, an architecture imbued with continuity and fold. Deleuze Leibniz Continuity Event Fold Divergent continuity Intensive continuity Torsional continuity Tenorsional continuity Dramatization-poeticization Continuité Événement Pli Dramatisation-poétisation Continuité divergente Continuité intensive Continuité torsionnelle Continuité ten(or)sionnelle Philosophy / Philosophie (UMI : 0422)
257	Multifunctional Laminated Composites for Morphing Structures Chillara, Venkata Siva Chaithanya 13 September 2018 (has links) No description available. Aerospace Materials Automotive Materials Engineering Mechanical Engineering Mechanics laminated composite multifunctional prestressed curvature zero Poisson ratio anisotropy elastomer analytical model morphing bistable fold origami actuation fender skirt shape memory alloys fluidic strain energy minimization automotive
258	Charakterisierung der lokalen Kontrolle des Stoffwechsels und der Durchblutung im subkutanen Fettgewebe Adams, Frauke 12 May 2006 (has links) Ein wichtiger Regulator der Lipolyse im Fettgewebe ist das sympathische Nervensystem. Über die Bedeutung präsynaptischer Faktoren (z.B. der lokalen Noradrenalinfreisetzung) des Fettgewebes ist jedoch wenig bekannt. Zudem sezerniert das Fettgewebe Signalmoleküle, die die lokale Lipolyse beeinflussen können, z.B. Angiotensin II (Ang II). Die Lipolyse hängt zudem von der Durchblutung und der Zellularität des Gewebes ab. Es wurde geprüft, ob (I) die lokale neuronale Noradrenalinfreisetzung die Durchblutung und den Stoffwechsel im subkutanen abdominalen Fettgewebe (SAF) beeinflußt und geschlechtsspezifische Unterschiede vorliegen, (II) Ang II die Durchblutung und den Stoffwechsel des SAF inhibiert, (III) Durchblutung und Stoffwechsel des SAF bei Schlanken von der Hautfaltendicke abhängen. 42 Normalgewichtige (18 Männer, 24 Frauen) wurden mit der Mikrodialysetechnik untersucht. Das adrenerge System des SAF wurde mit Isoproterenol (Iso) und Tyramin (Tyr) charakterisiert. Mittels Ethanol-Dilutionstechnik, [Glycerol], [Lactat] und [Glucose] im Dialysat wurden Änderungen in Durchblutung, Lipolyse, Glycolyse und Glucoseversorgung abgeschätzt. Die Hautfaltendicke wurde mittels Caliper-Technik bestimmt. Niedrigere Tyr-Dosen erhöhten die Lipolyse im SAF, die Durchblutung blieb konstant. Der Lipolyseanstieg war bei den Frauen größer als bei den Männern, war aber auch unter Iso bei den Frauen höher. Ang II verminderte zumindest im SAF der Frauen leicht die Durchblutung und indirekt die Lipolyse. Die Hautfaltendicke korrelierte geschlechtsunabhängig negativ-linear mit der Durchblutung und der Lipolyse. Die lokale neuronale Noradrenalinfreisetzung spielt eine wichtige Rolle in der Regulation der Lipolyse des SAF. Die geschlechtsspezifischen Unterschiede sind auf postsynaptische Faktoren zurückzuführen. Ang II beeinflußt die Durchblutung und die Lipolyse des SAF nur gering. Durchblutung und Stoffwechsel des SAF sind schon bei Normalgewichtigen mit zunehmender Hautfaltendicke vermindert. / The sympathetic nerve system is one important regulator of lipolysis. The regulatory role of neuronal transmitter release (e.g. of norepinephrine) and re-uptake in adipose tissue is only poorly understood. Furthermore, adipose tissue secretes hormones, e.g. angiotensin II (Ang II), which can affect adipose tissue lipolysis. Finally, lipolysis depends on blood flow and cellularity of adipose tissue. Aims of this thesis were (I) to characterize the impact of local neuronal norepinephrine release on blood flow and metabolism in subcutaneous abdominal adipose tissue (SAT) and to assess possible gender effects, (II) to proof if Ang II inhibits lipolysis and blood flow in SAT, and (III) to test if SAT thickness is negatively correlated with blood flow and metabolism even in non-obese subjects. 42 lean subjects (18 men, 24 women) were studied using microdialysis technique. Tyramine (Tyr) and isoproterenol (Iso) were used to characterize adrenergic response of SAT. Dialysate [ethanol], [glycerol], [lactate], and [glucose] were measured to assess tissue blood flow (ethanol dilution technique), lipolysis, glycolysis, and nutritive supply. Skin fold thickness was taken to assess thickness of SAT. During perfusion with lower Tyr doses, ethanol ratio remained unchanged, whereas lipolysis increased. The lipolytic response was higher in women vs. men, a gender difference was also observed for Iso-stimulated lipolysis. During perfusion with Ang II, blood flow and lipolysis decreased slightly at least in women. Skin fold thickness was negatively correlated with tissue perfusion and lipolysis without gender-specific differences. Neuronal norepinephrine release plays an important role in the regulation of lipolysis of SAT. The gender difference is explained by a difference in postsynaptic adrenergic sensitivity. Ang II has a minimal effect on local blood flow and metabolism. Increased SAT thickness is associated with reduced tissue perfusion and lipid metabolism, even in lean subjects. Sympathisches Nervensystem Lipolyse adrenerge Rezeptoren Hautfaltendicke sympathetic nervous system lipolysis adrenergic receptors skin fold thickness 610 Medizin und Gesundheit 33 Medizin WX 2300 XG 2104 XG 2121 ddc:610
259	Strukturuntersuchungen an Proteinen der bakteriellen Stressantwort: NblA von Anabaena sp. PCC 7120 und Csp:ssDNA-Komplexe von Bacillus caldolyticus und Bacillus subtilis Bienert, Ralf 11 December 2006 (has links) Die meisten Cyanobakterien und Chloroplasten von Rotalgen verfügen über Phycobilisomen, große lichtsammelnde Multiproteinkomplexe, die an der cytoplasmatischen Seite der Thylakoidmembran gebunden vorliegen. Unter stickstofflimitierten Bedingungen werden die Phycobilisomen proteolytisch abgebaut. Dieser Prozess schützt vor Fotoschäden unter den gegebenen Stressbedingungen und liefert gleichzeitig einen großen Vorrat an Stickstoff enthaltenden Substanzen. Das Gen nblA, welches in allen Phycobilisomen enthaltenden Organismen vorkommt, kodiert für ein Polypeptid von ungefähr 7 kDa, das eine Schlüsselrolle im Abbau der Phycobilisomen einnimmt. Die Wirkungsweise von NblA dabei wird jedoch bisher kaum verstanden. Ein Selenomethioninderivat von NblA des filamentösen Cyanobakteriums Anabaena sp. PCC 7120 wurde in Escherichia coli rekombinant hergestellt, gereinigt und kristallisiert. Die Röntgenkristallstruktur von NblA wurde mithilfe der single-wavelength anomalous dispersion-Methode bis zu einer Auflösung von 1,8 Angstrom bestimmt. Das finale Modell verfügt über einen kristallographischen R-Wert von 18,2% und einen freien R-Wert von 21,7%. Das kleine NblA-Protein von 65 Aminosäuren besteht aus zwei alpha-Helices, die in einem ca. 37°-Winkel in einer antiparallelen, V-förmigen Anordnung zueinander stehen. Zwei dieser Monomere bilden die grundlegende strukturelle Einheit von NblA, ein vier-Helix-Bündel, bei dem sich die Spitzen der "Vs" auf der gleichen Seite des Dimers überlagern und über eine nicht-kristallographische zweizählige Achse miteinander verknüpft sind. Auf der Grundlage von Bindungsstudien und der Kenntnis der NblA-Struktur konnte ein Modell für die Bindung von NblA an die Phycobilisomenstruktur postuliert werden. / Cyanobacterial light harvesting complexes, the phycobilisomes, are proteolytically degraded when the organisms are starved for combined nitrogen, a process referred to as chlorosis or bleaching. Gene nblA, present in all phycobilisome-containing organisms, encodes a protein of about 7 kDa that plays a key role in phycobilisome degradation. To gain deeper insights into the mode of action of NblA in this degradation process the crystal structure of NblA was determined and a model of its binding to phycobilisomes was proposed. For this purpose, NblA from Anabaena sp. PCC 7120 was produced as selenomethionine NblA derivative in Escherichia coli B834 (DE3), purified and crystalized. NblA crystals grew as long, but thin rods and belong to the monoclinic space group P2(1) with cell parameters of a = 43.2 A, b = 95.9 A, c = 104.8 A and Beta = 97.0°. They contain twelve NblA monomers in the asymmetric unit. The crystal structure with a resolution of 1.8 A was determined using the single-wavelength anomalous dispersion (SAD) technique and refined to final values for Rwork and Rfree of 0.182 and 0.217, respectively. The small NblA polypeptide of 65 amino acids consists of two alpha-helices which are assembled at a ~37° angle in an antiparallel, V-shaped arrangement. Two NblA monomers form the basic structural unit of NblA, a four-helix bundle with the tips of the V superimposing on the same side of a dimer. The dimer is formed by two molecules related by a non-crystallographic dyad axis. Based on the crystal structure presented here, pull-down experiments, and peptide scan data a model of binding of NblA to phycobilisomes was proposed. Considering the entire phycobilisome structure, NblA is predicted to bind via its amino acids Leu51 and Lys53 to the trimer-trimer interface of the phycobiliprotein hexamers. Cyanobakterien Phycobilisom Proteolyse NblA Chlorosis Kristall Struktur Kälteschock OB-Faltungstyp Phycobilisome Cyanobacteria Proteolysis NblA Chlorosis Crystal Structure Cold shock OB-Fold 570 Biologie 32 Biologie WF 5200 ddc:570
260	Demography of Birch Populations across Scandinavia Sendrowski, Janek January 2022 (has links) Boreal forests are particularly vulnerable to climate change, experiencing a much more drastic increase in temperatures and having a limited amount of more northern refugia. The trees making up these vast and important ecosystems already had to adapt previously to environmental pressures brought about by the repeated glaciations during past ice ages. Studying the patterns of adaption of these trees can thus provide valuable insights on how to mitigate future damage. This thesis presents and analyses population structure, demo- graphic history and the distribution of fitness effects (DFE) of the diploid Betula pendula and tetraploid B. pubescens across Scandinavia. Birches–being widespread in boreal forests as well as having great economical importance–constitute superb model species. The analyses of this work confirm the expectations on postglacial population expansion and diploid-tetraploid introgression. They furthermore ascertain the presence of two genetic clusters and a remarkably similar DFE for the species. This work also contributes with a transparent, reproducible and reusable pipeline which facilitates running similar analyses for related species. birch betula pubescens pendula betula pubescens betula pendula silver birch downy birch demography population structure distribution of fitness effects DFE dadi UMAP PCA ADMIXTURE polyDFE ice age glaciation tree boreal forest climate change adaption tetraploid diploid-tetraploid introgression Scandinavia genetic cluster pipeline snakemake bioinformatics reproducible population genetics postglacial population expansion demographic history FEEMS site-frequency spectrum SFS last glacial maximum LGM workflow python population expansion population growth EST-SFS 0-fold degenerate 4-fold degenerate maximum likelihood estimation MLE variant call format VCF single-nucleotide polymorphism SNP Bioinformatics (Computational Biology) Bioinformatik (beräkningsbiologi)

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