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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.
141

Self-organized traffic flows: a sequential conflict resolution approach

Hand, Troy S. 20 September 2013 (has links)
This thesis discusses the effect of sequential conflict resolution maneuvers of a continuous flow of agents through a finite control volume. Video analysis of real world traffic flows that exhibit self-organized capabilities is conducted to extract characteristics of those agents. A tool is created which stabilizes the input video and extracts motion from it using the background subtraction method. I discuss the tool in detail as I created it to be user friendly and easily modifiable for other uses. The aim of the video analysis I conduct is to determine characteristics of agents in self-organized traffic flow. Comparisons are made with agents under sequential conflict resolution schemes and those that exhibit these self-organized capabilities to determine if agents under sequential control can approach the behaviors of those in self-organized environment. Flow geometries are studied and generalized with the goal of determining stability characteristics of arbitrary flow geometries. Stability analysis includes analytical proof of bounds on the conflict resolution maneuvers.
142

O-minimality, nonclassical modular functions and diophantine problems

Spence, Haden January 2018 (has links)
There now exists an abundant collection of conjectures and results, of various complexities, regarding the diophantine properties of Shimura varieties. Two central such statements are the Andre-Oort and Zilber-Pink Conjectures, the first of which is known in many cases, while the second is known in very few cases indeed. The motivating result for much of this document is the modular case of the Andre-Oort Conjecture, which is a theorem of Pila. It is most commonly viewed as a statement about the simplest kind of Shimura varieties, namely modular curves. Here, we tend instead to view it as a statement about the properties of the classical modular j-function. It states, given a complex algebraic variety V, that V contains only finitely many maximal special subvarieties, where a special variety is one which arises from the arithmetic behaviour of the j-function in a certain natural way. The central question of this thesis is the following: what happens if in such statements we replace the j-function with some other kind of modular function; one which is less well-behaved in one way or another? Such modular functions are naturally called nonclassical modular functions. This question, as we shall see, can be studied using techniques of o-minimality and point-counting, but some interesting new features arise and must be dealt with. After laying out some of the classical theory, we go on to describe two particular types of nonclassical modular function: almost holomorphic modular functions and quasimodular functions (which arise naturally from the derivatives of the j-function). We go on to prove some results about the diophantine properties of these functions, including several natural Andre-Oort-type theorems, then conclude by discussing some bigger-picture questions (such as the potential for nonclassical variants of, say, Zilber-Pink) and some directions for future research in this area.
143

Experiências educativas: ressonâncias de intercessões fílmicas

Cardonetti, Vivien Kelling 12 1900 (has links)
This work intends to put into motion different fluxes of thinking through three filmic intersections, inspiring uS to think the education experience. This study considers what has the power of affecting and disturbing in a filmic encounter, making the production of different arrangements and contextures possible. Through the experience of watching the short film 'Los colores de las flores' (along with students from the distance undergraduate course in Special Education at Federal University of Santa Maria - UFSM), the issues triggered by the encounter with the movie 'A invenção de Hugo Cabret' (watched along with students and supervisors at the Institutional Program of Teaching Initiation Grant - PIBID - in Visual Arts at UFSM), and the crossing between the movie 'O Balão Branco' and Jorge Larrosa's book 'Pedagogia Profana' (established by Visual Arts undergraduate students in the courses Supervised Teaching Practice II and IV), it was possible to propose problematizations in relation to these intersections and teaching, dialoguing with two lines of thought which overflow and move the thinking in this thesis: multiplicity and evento The problematizations arisen from the inter-relation among the filmic images, the spaces of inventive incidence with the child potency, the narratives and diaries produced by the undergraduate students involved in this investigation, and the concepts operated in this research, specially the French philosophers Gilles Deleuze and Félix Guattari's concepts, acted as a resonance vector, driving the questioning of the unquestionable, and stimulating the invention of multiple and unique scenes in education through the echoes passed on. / Este trabalho intenciona movimentar diferentes fluxos de pensamentos a partir de três intercessões fílmicas, incitando a pensar a experiência educativa. Busca-se dar atenção àquilo que tem a potência de afetar e inquietar em um encontro fílmico, possibilitando a produção de diferentes arranjos e tessituras. A partir da experiência em assistir ao curta-metragem ‘Los colores de las flores’ (com os acadêmicos do Curso de Graduação a Distância de Educação Especial – EAD – da Universidade Federal de Santa Maria – UFSM), das questões disparadas pelo encontro com o filme ‘A Invenção de Hugo Cabret’ (assistido junto aos acadêmicos e supervisoras do Programa Institucional de Bolsa de Iniciação à Docência – PIBID – das Artes Visuais da UFSM) e do atravessamento entre o filme ‘O Balão Branco’ e o livro ‘Pedagogia Profana’, de Jorge Larrosa (com os acadêmicos da Graduação em Artes Visuais da UFSM, nas disciplinas de Estágio Supervisionado III e IV), foi possível tecer problematizações em relação a essas intercessões e a docência, dialogando com duas vertentes que transbordam e movimentam o pensamento desta tese: multiciplicidade e acontecimento. As problematizações suscitadas a partir do cruzamento das imagens fílmicas selecionadas, dos espaços de incidência inventiva com a potência infante, das narrativas e dos diários produzidos pelos acadêmicos envolvidos na investigação e dos conceitos operados na pesquisa, especialmente os conceitos dos filósofos franceses Gilles Deleuze e Félix Guattari, agiram como um vetor de ressonâncias, impulsionando o questionamento do inquestionável e possibilitando, a partir dos ecos repercutidos, inventar múltiplas e singulares cenas para a educação.
144

Correlational Analysis of Drivers Personality Traits and Styles in a Distributed Simulated Driving Environment

Abbas, Muhammad Hassan, Khan, Mati-ur-Rehman January 2007 (has links)
In this thesis report we conducted research study on driver's behavior in T-Intersections using simulated environment. This report describes and discusses correlation analysis of driver's personality traits and style while driving at T-Intersections. The experiments were performed on multi user driving simulator under controlled settings, at Linköping University. A total of forty-eight people participated in the study and were divided into groups of four, all driving in the same simulated world. During the experiments participants were asked to fill a series of well-known self-report questionnaires. We evaluated questionnaires to get the insight in driver's personality traits and driving style. The self-report questionnaires consist of Schwartz's configural model of 10 values types and NEO-five factor inventory. Also driver's behavior was studied with the help of questionnaires based on driver's behavior, style, conflict avoidance, time horizon and tolerance of uncertainty. Then these 10 Schwartz's values are correlated with the other questionnaires to give the detail insight of the driving habits and personality traits of the drivers.
145

Cvičebnice Mongeova promítání / Workbook of Monge projection

Pajerová, Nikola January 2016 (has links)
In this thesis there can be found various examples from Monge projection. The theory is summarized in the beginning, which is important of understanding the projection and for solving the examples. There are also examples of solving axial affinity and central collineation. Then there is a chapter about the projection of all types of angular and rotational solids, which are solved at the secondary schools. Then follows a chapter, where the sections of these solids are constructed. In the last chapter, there are solved intersection of solids from each type. Powered by TCPDF (www.tcpdf.org)
146

Understanding molecular dynamics with coherent vibrational spectroscopy in the time-domain

Liebel, Matz January 2014 (has links)
This thesis describes the development of several spectroscopic methods based on impulsive vibrational spectroscopy as well as of the technique itself. The first chapter describes the ultrafast time domain Raman spectrometer including the development of two noncollinear optical parametric amplifiers for sub-10 fs pulse generation with 343 or 515 nm pumping. In the first spectroscopic study we demonstrate, for the first time, that impulsive vibrational spectroscopy can be used for recording transient Raman spectra of molecules in excited electronic states. We obtain spectra of beta-carotene with comparable, or better, quality than established frequency domain based nonlinear Raman techniques. The following two chapters address the questions on the fate of vibrational coherences when generated on a reactive potential energy surface. We photoexcite bacteriorhodopsin and observe anharmonic coupling mediated vibrational coherence transfer to initially silent vibrational modes. Additionally, we are able to correlate the vibrational coherence activation with the efficiency of the isomerisation reaction in bR. Upon generation of vibrational coherence in the second excited electronic state of beta-carotene, by excitation from the ground electronic state, we are able to follow the wavepacket motion out of the Franck-Condon region. We observe vibrationally coherent internal conversion, through a conical intersection, into the first excited electronic state and are hence able to demonstrate that electronic surface crossings can occur in a vibrationally coherent fashion. Additionally, we find strong evidence for vibronic coupling mediated back and forth crossing between the two electronic states. As a combination of this work we develop a IVS based technique that allows for the direct recording of background and baseline free Raman spectra in the time domain. Several proof of principle experiments highlight the capabilities of this technique for time resolved Raman spectroscopy. In the final chapter we present work on weak-field coherent control. Here, we address the question of whether a photochemical reaction can be controlled by the phase term of an electric excitation field, in the one photon excitation limit. We study the systems rhodamine 101, bacteriorhodopsin, rhodopsin and isorhodopsin and, contrary to previous reports, find no evidence for one photon control.
147

Images et fibres des applications rationnelles et algèbres d'éclatement / Images and fibers of rational applications and burst algebra

Tran, Quang Hoa 17 November 2017 (has links)
Les applications rationnelles sont des objets fondamentaux en géométrie algébrique. Elles sont utilisées pour décrire certains objets géométriques, tels que la représentation paramétrique d'une variété algébrique rationnelle. Plus récemment, les applications rationnelles sont apparues dans des contextes d'informatique pour l'ingénierie, dans le domaine de la modélisation de formes, en utilisant des méthodes de conception assistée par ordinateur pour les courbes et les surfaces. Des paramétrisations des courbes et des surfaces sont utilisées de manière intensive afin décrire des objets dans la modélisation géométrique, tel que structures des voitures, des avions. Par conséquent, l'étude des applications rationnelles est d'intérêt théorique dans la géométrie algébrique et l'algèbre commutative, et d'une importance pratique dans la modélisation géométrique. Ma thèse étudie les images et les fibres des applications rationnelles en relation avec les équations des algèbres de Rees et des algèbres symétriques. Dans la modélisation géométrique, il est important d'avoir une connaissance détaillée des propriétés géométriques de l'objet et de la représentation paramétrique avec lesquels on travaille. La question de savoir combien de fois le même point est peint (c'est-à-dire, correspond à des valeurs distinctes du paramètre), ne concerne pas seulement la variété elle-même, mais également la paramétrisation. Il est utile pour les applications de déterminer les singularités des paramétrisations. Dans les chapitres 2 et 3, on étudie des fibres d'une application rationnelle de P^m dans P^n qui est génériquement finie sur son image. Une telle application est définie par un ensemble ordonné de (n+1) polynômes homogènes de même degré d. Plus précisément, dans le chapitre 2, nous traiterons le cas des paramétrisations de surfaces rationnelles de P^2 dans P^3, et y donnons une borne quadratique en d pour le nombre de fibres de dimension 1 de la projection canonique de son graphe sur son image. Nous déduisons ce résultat d'une étude de la différence du degré initial entre les puissances ordinaires et les puissances saturées. Dans le chapitre 3, on affine et généralise les résultats sur les fibres du chapitre précédent. Plus généralement, nous établissons une borne linéaire en d pour le nombre de fibres (m-1)-dimensionnelles de la projection canonique de son graphe sur son image, en utilisant des idéaux de mineurs de la matrice jacobienne.Dans le chapitre 4, nous considérons des applications rationnelles dont la source est le produit de deux espaces projectifs.Notre principal objectif est d'étudier les critères de birationalité pour ces applications. Tout d'abord, un critère général est donné en termes du rang d'une couple de matrices connues sous le nom "matrices jacobiennes duales". Ensuite, nous nous concentrons sur des applications rationnelles de P^1 x P^1 vers P^2 en bidegré bas et fournissons de nouveaux critères de birationalité en analysant les syzygies des équations de définition de l'application; en particulier en examinant la dimension de certaines parties bigraduées du module de syzygies. Enfin, les applications de nos résultats au contexte de la modélisation géométrique sont discutées à la fin du chapitre. / Rational maps are fundamental objects in algebraic geometry. They are used to describe some geometric objects,such as parametric representation of rational algebraic varieties. Lately, rational maps appeared in computer-engineering contexts, mostly applied to shape modeling using computer-aided design methods for curves and surfaces. Parameterized algebraic curves and surfaces are used intensively to describe objects in geometric modeling, such as car bodies, airplanes.Therefore, the study of rational maps is of theoretical interest in algebraic geometry and commutative algebra, and of practical importance in geometric modeling. My thesis studies images and fibers of rational maps in relation with the equations of the symmetric and Rees algebras. In geometric modeling, it is of vital importance to have a detailed knowledge of the geometry of the object and of the parametric representation with which one is working. The question of how many times is the same point being painted (i.e., corresponds to distinct values of parameter), depends not only on the variety itself, but also on the parameterization. It is of interest for applications to determine the singularities of the parameterizations. In the chapters 2 and 3, we study the fibers of a rational map from P^m to P^nthat is generically finite onto its image. More precisely, in the second chapter, we will treat the case of parameterizations of algebraic rational surfaces. In this case, we give a quadratic bound in the degree of the defining equations for the number of one-dimensional fibers of the canonical projection of the graph of $\phi$ onto its image,by studying of the difference between the initial degree of ordinary and saturated powers of the base ideal. In the third chapter, we refine and generalize the results on fibers of the previous chapter.More generally, we establish a linear bound in the degree of the defining equations for the number of (m-1)-dimensional fibers of the canonical projection of its graph onto its image, by using ideals of minors of the Jacobian matrix.In the fourth chapter, we consider rational maps whose source is a product of two subvarieties, each one being embedded in a projective space. Our main objective is to investigate birationality criteria for such maps. First, a general criterion is given in terms of the rank of a couple of matrices that came to be known as "Jacobian dual matrices". Then, we focus on rational maps from P^1 x P^1 to P^2 in very low bidegrees and provide new matrix-based birationality criteria by analyzing the syzygies of the defining equations of the map, in particular by looking at the dimension of certain bigraded parts of the syzygy module. Finally, applications of our results to the context of geometric modeling are discussed at the end of the chapter.
148

Opérateurs de typage non-idempotents, au delà du lambda-calcul / Non-idempotent typing operators, beyond the lambda-calculus

Vial, Pierre 07 December 2017 (has links)
L'objet de cette thèse est l'extension des méthodes de la théorie des types intersections non-idempotents, introduite par Gardner et de Carvalho, à des cadres dépassant le lambda-calcul stricto sensu.- Nous proposons d'abord une caractérisation de la normalisation de tête et de la normalisation forte du lambda-mu calcul (déduction naturelle classique) en introduisant des types unions non-idempotents. Comme dans le cas intuitionniste, la non-idempotence nous permet d'extraire du typage des informations quantitatives ainsi que des preuves de terminaison beaucoup plus élémentaires que dans le cas idempotent. Ces résultats nous conduisent à définir une variante à petits pas du lambda-mu-calcul, dans lequel la normalisation forte est aussi caractérisée avec des méthodes quantitatives. - Dans un deuxième temps, nous étendons la caractérisation de la normalisation faible dans le lambda-calcul pur à un lambda-calcul infinitaire étroitement lié aux arbres de Böhm et dû à Klop et al. Ceci donne une réponse positive à une question connue comme le problème de Klop. À cette fin, il est nécessaire d'introduire conjointement un système (système S) de types infinis utilisant une intersection que nous qualifions de séquentielle, et un critère de validité servant à se débarrasser des preuves dégénérées auxquelles les grammaires coinductives de types donnent naissance. Ceci nous permet aussi de donner une solution au problème n°20 de TLCA (caractérisation par les types des permutations héréditaires). Il est à noter que ces deux problèmes n'ont pas de solution dans le cas fini (Tatsuta, 2007).- Enfin, nous étudions le pouvoir expressif des grammaires coinductives de types, en dehors de tout critère de validité. Nous devons encore recourir au système S et nous montrons que tout terme est typable de façon non triviale avec des types infinis et que l'on peut extraire de ces typages des informations sémantiques comme l'ordre (arité) de n'importe quel lambda-terme. Ceci nous amène à introduire une méthode permettant de typer des termes totalement non-productifs, dits termes muets, inspirée de la logique du premier ordre. Ce résultat prouve que, dans l'extension coinductive du modèle relationnel, tout terme a une interprétation non vide. En utilisant une méthode similaire, nous montrons aussi que le système S collapse surjectivement sur l'ensemble des points de ce modèle. / In this dissertation, we extend the methods of non-idempotent intersection type theory, pioneered by Gardner and de Carvalho, to some calculi beyond the lambda-calculus.- We first present a characterization of head and strong normalization in the lambda-mu calculus (classical natural deduction) by introducing non-idempotent union types. As in the intuitionistic case, non-idempotency allows us to extract quantitative information from the typing derivations and we obtain proofs of termination that are far more elementary than those in the idempotent case. These results leads us to define a small-step variant of the lambda-mu calculus, in which strong normalization is also characterized by means of quantitative methods.- In the second part of the dissertation, we extend the characterization of weak normalization in the pure lambda-calculus to an infinitary lambda-calculus narrowly related to Böhm trees, which was introduced by Klop et al. This gives a positive answer to a question known as Klop's problem. In that purpose, it is necessary to simultaneously introduce a system (system S) featuring infinite types and resorting to an intersection operator that we call sequential, and a validity criterion in order to discard unsound proofs that coinductive grammars give rise to. This also allows us to give a solution to TLCA problem #20 (type-theoretic characterization of hereditary permutations). It is to be noted that those two problem do not have a solution in the finite case (Tatsuta, 2007).- Finally, we study the expressive power of coinductive type grammars, without any validity criterion. We must once more resort to system S and we show that every term is typable in a non-trivial way with infinite types and that one can extract semantical information from those typings e.g. the order (arity) of any lambda-term. This leads us to introduce a method that allows typing totally unproductive terms (the so-called mute terms), which is inspired from first order logic. This result establishes that, in the coinductive extension of the relational model, every term has a non-empty interpretation. Using a similar method, we also prove that system S surjectively collapses on the set of points of this model
149

Cyclist Path Choices Through Shared Space Intersections in England

Duncan, Allison Boyce 11 March 2016 (has links)
In the last several years, there has been growing worldwide interest in making streets safer for all users--pedestrians, cyclists, and motorists. One approach, shared space, is a traffic calming technique as well as urban design concept. This technique strives to fully integrate the roadway into the urban fabric by removing elements such as lane markings, curbs, and traffic signs. By removing these elements and creating a more plaza-like space, these sites become ambiguous and no user group as priority. The technique is relatively new, and the majority of existing research concerns pedestrians only. This mixed methods research focused on six intersections in England with the goal of understanding how bicycle riders perceive and travel through shared space intersections. Using video observations of the six sites in three cities, three shared and three control, this project analyzed the variations in the paths cyclists rode through the intersections. Data were collected on several variables related to both the cyclists and their interactions with the site itself such as helmet use and riding through crosswalks. Path analysis required the development a new evaluative variable in order to compare individual paths by how much deviation there was in each path ridden as compared to other cyclists. Site-specific surveys addressed the perceptions, bicycling experience, demographics, and path and route preferences by cyclists at both shared space and control intersections. The analysis indicated that cyclists rode similarly through both shared and control intersections, and that a large percentage of riders preferred to ride farther from motor vehicles when given the space to do so. This project offered further insight in how to best design shared space projects for nonmotorized users by looking at the spatial layout and the elements that most influenced a rider’s path choice. Results indicated that, in these cases, shared space was not the panacea for nonmotorized users as some literature suggests, but nonetheless appeared to be a valid form of traffic calming. This research offered further insight in how to best design shared space projects for nonmotorized users by looking at the spatial layout and the elements that most influenced a rider’s path choice.
150

Bicyclist Compliance at Signalized Intersections

Thompson, Samson Ray Riley 30 March 2015 (has links)
This project examined cyclist red light running behavior using two data sets. Previous studies of cyclist compliance have investigated the tendencies of cyclists to run red lights on the whole by generalizing different maneuvers to their end outcome, running a red light. This project differentiates between the different types of red light running and focuses on the most egregious case, gap acceptance, which is when a cyclist runs a red light by accepting a gap in opposing traffic. Using video data, a mathematical model of cyclist red light running was developed for gap acceptance. Similar to other studies, this analysis utilized only information about the cyclist, intersection, and scenario that can be outwardly observed. This analysis found that the number of cyclists already waiting at the signal, the presence of a vehicle in the adjacent lane, and female sex were deterrents to red light running. Conversely, certain types of signal phasing, witnessing a violation, and lack of helmet increased the odds that a cyclist would run the red light. Interestingly, while women in general are less likely to run a red light, those who witnessed a violation were even more prone that men who had witnessed a violation to follow suit and run the red light themselves. It is likely that the differing socialization of women and men leads to different effects of witnessing a previous violator. The analysis also confirmed that a small subset of cyclists, similar to that found in the general population, are more prone to traffic violations. These cyclists are more willing to engage in multiple biking-related risk factors that include not wearing a helmet and running red lights. Although the model has definite explanatory power regarding decisions of cyclist compliance, much of the variance in the compliance choices of the sample is left unexplained. This points toward the influence of other, not outwardly observable variables on the decision to run a red light. Analysis of survey data from cyclists further confirms that individual characteristics not visible to the observer interact with intersection, scenario, and visible cyclist characteristics to result in a decision to comply (or not) with a traffic signal. Furthermore, cyclist characteristics, in general, and unobservable individual characteristics, specifically, play a larger role in compliance decisions as the number of compliance-inducing intersection traits (e.g. conflicting traffic volume) decrease. One such unobservable trait is the regard for the law by some cyclists, which becomes a more important determinant of compliance at simpler intersections. Cyclists were also shown to choose non-compliance if they questioned the validity of the red indication for them, as cyclists. The video and survey data have some comparable findings. For instance, the relationship of age to compliance was explored in both data analyses. Age was not found to be a significant predictor of non-compliance in the video data analysis while it was negatively correlated with stated non-compliance for two of the survey intersections. Gender, while having significant effects on non-compliance in the video dataset, did not emerge as an important factor in the stated non-compliance of survey takers. Helmet use had a consistent relationship with compliance between the video and survey datasets. Helmet use was positively associated with compliance in the video data and negatively associated with revealed non-compliance at two of the survey intersections. When coupled with the positive association between normlessness and stated willingness to run a red light, the relationship between helmet use and compliance solidifies the notion that a class of cyclists is more likely to consistently violate signals. It points towards a link between red light running and individuals who do not adhere to social norms and policies as strictly as others. Variables representing cyclists and motorists waiting at the signal were positively related to signal compliance in the video data. While an increased number of cyclists may be a physical deterrent to red light running, part of the influence on compliance that this variable and the variable representing the presence of a vehicle may be due to accountability of cyclists to other road users. This relationship, however, was not revealed in the stated non-compliance data from the survey. Efforts to increase cyclist compliance may not be worth a jurisdiction's resources since nearly 90% of cyclists in the video data were already compliant. If a problem intersection does warrant intervention, different methods of ensuring bicyclist compliance are warranted depending on the intersection characteristics. An alternative solution is to consider the applicability of traffic laws (originally designed for cars) to bicyclists. Creating separation in how laws affect motorists and cyclists might be a better solution for overly simple types of intersections where cyclists have fewer conflicts, better visibility, etc. than motorists. Education or other messaging aimed at cyclists about compliance is another strategy to increase compliance. Since cyclists appear to feel more justified in running red lights at low-volume, simple-looking intersections, it would probably be prudent to target messaging at these types of intersections. Many cyclists are deterred by high-volume and/or complicated looking intersections for safety reasons. Reminding cyclists of the potential dangers at other intersections may be a successful messaging strategy. Alternatively, reminding cyclists that it is still illegal to run a red light even if they feel safe doing so may be prudent. Additionally, messaging about the purpose of infrastructure such as bicycle-specific signals or lights that indicate detection at a signal may convince cyclists that stopping at the signal is in their best interest and that the wait will be minimal and/or warranted.

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