Discerning the basis of phenotypic and genotypic differences within and between taxa is crucial for understanding the evolution of species, subspecies or varieties and races. In this dissertation, I have presented three studies, which use morphological characters and genetic Amplified Fragment Length Polymorphisms (AFLPs) to differentiate cytotypes, populations and species of the genus Xanthisma. The first study is aimed at clarifying the species status of Haplopappus ravenii, which has been considered to be a separate species by some taxonomists and a race of Xanthisma gracile by other researchers. Considering the morphological species concept and the genotypic cluster definition of a species, there was insufficient distinction in either dataset to support these taxa as distinct species. It was found that H. ravenii is more appropriately classified as a a cytotype or a race of X. gracile. In the second study, the genetic structure of X. gracile was quantified across populations occupying distinct habitat types (desert, grasslands, and pinyon juniper woodlands) in order to test the hypothesis of local adaptation and to determine the potential for intraspecific divergence. Samples from desert habitats showed higher genetic divergence than samples in the other two habitats. This study is indicative of local adaptation of populations and that changes in climate and habitat play a very important role in the genetic differentiation of plant systems. The third study evaluated the taxonomy of Xanthisma spinulosum and three of its subspecies that co-occur in Arizona. Herbarium specimens representative of the three subspecies were used to test for significant morphological and genetic divergence that would support their recognition. The morphological characters originally utilized by taxonomists who named these taxa were not significantly different among the three taxa. This finding was further supported by the molecular data, suggesting the presence of one contiguous species. This dissertation aims at stressing the importance of taxonomic status and understanding the role that environment can play on shaping differentiation between taxa.

京都大学 / 新制・課程博士 / 博士(理学) / 甲第24457号 / 理博第4956号 / 新制||理||1707(附属図書館) / 京都大学大学院理学研究科生物科学専攻 / (主査)准教授 中野 隆文, 教授 本川 雅治, 教授 森 哲 / 学位規則第4条第1項該当 / Doctor of Science / Kyoto University / DGAM

In this study I analyse how authors of alternate history books use history in their works based on the central themes the authors use in their books. The source material used in this study is three different alternate history books from three different authors based on three different time periods.  The results of this study were that you can find connections between the central themes the authors use to the use of history. While the works the authors have produces primarily exist to entertain the reader and to tell a entertaining story the Authors also use history in an ideological way to show support or legitimise social and political movements that they support. The authors also showcase a moral use of history to condemn certain historical practises and social norms and using this critique to show a desire for change and to critique certain modern uses of history by certain groups.

It is reasonable to assume that an aircraft might experience some in-flight discrete source damage caused by various incidents. It is, thus, necessary to evaluate the impact of such damage on the performance of the aircraft. This study is focused on evaluating the effect of a simple discrete damage in an aircraft wing on its static and dynamic response. The damaged wing is modeled by a thin-walled beam with a longitudinal crack the response of which can be obtained analytically. As uncertainties are present in the location and size of the crack as well as in the applied loads, their effects are incorporated into the framework consisting of structural response, crack propagation and aeroelasticity. The first objective of this study is to examine the effect of damage represented by a crack on the wing flexibility that influences its deformation and aero-elastic divergence characteristics. To study this, the thin-walled beam is modeled by Benscoter thin-walled beam theory combined with Gunnlaugsson and Pedersen compatibility conditions to accurately account for the discontinuity at the interface of the cracked and uncracked beam segments. Instead of conducting a detailed finite element analysis, the solution is obtained in an exact sense for general distributed loads representing the wind pressure effects. This analytical approach is shown to provide very accurate values for the global beam response compared with the detailed finite element shell analysis. This analytical solution is, then, used to study the beam response probabilistically. The crack location and size are assumed to be uncertain and are, thus, characterized by random variable. For a specified limit state, the probability of failure can be conveniently calculated by the first order second moment analysis using the safety index approach. The same analytical solution is also used to study the aero-elastic divergence characteristics of a wing, the inner structure of which is represented by a thin-walled beam with a crack of uncertain size and position along the beam. The second objective of this study is to examine the time growth of a crack under dynamic gust type of loading to which a wing is likely to be exposed during flight. Damage propagating during operation further deteriorates the safety of the aircraft and it is necessary to study its time growth so that its impact on the performance can be evaluated before it reaches its unstable state. The proposed framework for the crack growth analysis is based on classical fracture mechanics where the remaining flight time is obtained by Monte Carlo simulation in which various uncertainties are taken into account. To obtain equivalent cyclic loading required for crack growth analysis, random vibration analysis of the thin-walled beam is conducted for stochastic wind load defined by a gust load spectral density function. The probability of failure represented by the crack size approaching the critical crack size within the flight duration or the remaining flight time before a crack reaches its limiting value are obtained. This study with a simple representation of a wing and damage is anticipated to provide initial guidance for future studies to examine the impact of discrete source damage on the in-flight performance of the aircrafts, with the ultimate goal of minimizing the adverse effect and enhancing the safety of aircrafts experiencing damage. / Ph. D.

Identifying the forces responsible for driving genomic divergence during speciation is a major goal of research in evolutionary biology. Thus, many efforts have focused on disentangling these forces by modeling the evolutionary histories of interacting populations. Here, population genomic datasets and a diffusion approximation method is used to model the demographic scenarios that influence divergence between Heliconius erato and the incipient species Heliconius himera. The models support an isolation-with-migration scenario, with relatively low and heterogeneous rates of introgression between H. himera and H. erato cyrbia. Additionally, the models suggest a history of selection driving divergence and introgression patterns among H. himera and H. erato. Collectively, these results support H. himera’s status as an incipient species within the H. erato radiation and highlight the interplay of selection and demographic history in shaping heterogeneous patterns of genomic divergence between hybridizing species.

No description available.

京都大学 / 新制・課程博士 / 博士(理学) / 甲第24079号 / 理博第4846号 / 新制||理||1693(附属図書館) / 京都大学大学院理学研究科生物科学専攻 / (主査)教授 田村 実, 教授 工藤 洋, 教授 松下 智直 / 学位規則第4条第1項該当 / Doctor of Science / Kyoto University / DGAM

This thesis reports on a numerical investigation into the three-dimensional flow divergence around a high solidity vertical axis wind turbine. Three-dimensional unsteady Reynolds averaged Navier-Stokes simulations of an H-type vertical axis wind turbine were used to examine the impact of turbine aspect ratio and tip speed ratio on the flow divergence. The turbine height was changed to alter the turbine aspect ratio, while keeping the diameter constant, to ensure that the solidity and tip speed ratio values were comparable between the different aspect ratios tested. The power output of the turbine consistently increased with aspect ratio and the optimal tip speed ratio for peak performance was negligibly affected. The flow divergence results showed that larger aspect ratio turbines had significantly more flow divergence with a 1 m/s entrance velocity difference between the smallest and largest cases. These two results where contradictory as a larger aspect ratio turbine was more efficient even though it had a smaller fraction of the upstream flow entering the upwind pass. The reason for this result was that impact of the tip effects, which caused a power reduction near the end of the blades. The distance from the blade tips that experienced a power reduction was constant for turbines of aspect ratio one and greater, resulting in a smaller turbine having a greater fraction of its height effected by the tips. This caused the overall power output for a smaller aspect ratio turbine to be lower even though its centre performance was higher, due to an increased entrance velocity. The change in flow divergence with tip speed ratio was also examined to better understand the driving force behind the divergence. It was found that the turbine power output was not the direct cause of flow divergence. The blade forces, specifically the force generated in the upstream direction had a strong linear correlation with the upstream flow divergence. / Thesis / Master of Applied Science (MASc)

Dissertation abstract Title: Cross-entropy based combination of discrete probability distributions for distributed de- cision making Author: Vladimíra Sečkárová Author's email: seckarov@karlin.mff.cuni.cz Department: Department of Probability and Mathematical Statistics Faculty of Mathematics and Physics, Charles University in Prague Supervisor: Ing. Miroslav Kárný, DrSc., The Institute of Information Theory and Automation of the Czech Academy of Sciences Supervisor's email: school@utia.cas.cz Abstract: In this work we propose a systematic way to combine discrete probability distributions based on decision making theory and theory of information, namely the cross-entropy (also known as the Kullback-Leibler (KL) divergence). The optimal combination is a probability mass function minimizing the conditional expected KL-divergence. The ex- pectation is taken with respect to a probability density function also minimizing the KL divergence under problem-reflecting constraints. Although the combination is derived for the case when sources provided probabilistic type of information on the common support, it can applied to other types of given information by proposed transformation and/or extension. The discussion regarding proposed combining and sequential processing of available data, duplicate data, influence...

La localisation d’un véhicule via les techniques de SLAM (Simultaneous Localization And Mapping pour cartographie et localisation simultanées) a connu un essor important durant les 20 dernières années. Pourtant, peu d’approches ont tenté d’étendre ces algorithmes à une flotte de véhicules malgré les nombreuses applications potentielles. C’est ici l’objectif de cette thèse. Pour ce faire, une approche de SLAM monoculaire pour un seul véhicule a d’abord été développée. Celle-ci propose de coupler un filtre de Kalman étendu avec une représentation cartésienne des amers afin de produire des cartes de faible densité mais de qualité. En effet, l’extension à plusieurs véhicules nécessite des échanges permanents par l’intermédiaire de communications sans fil. Avec peu d’amers dans les cartes, notre approche s’accommode bien du nombre de véhicules de la flotte. Des capteurs peu onéreux ont aussi été privilégiés (une unique caméra et un odomètre) afin de réduire le coût d’une extension multivéhicule. Des correctifs ont été proposés afin d’éviter les problèmes de divergence induits par les choix précédents. Des expérimentations ont montré que la solution de SLAM produite était légère et rapide tout en fournissant une localisation de qualité. La dérive, inhérente à tout algorithme de SLAM, a également fait l’objet d’une analyse. Celle-ci a été intégrée au SLAM par l’intermédiaire d’une architecture dédiée et d’un modèle dynamique. Le but est de pouvoir rendre consistante la localisation fournie par le SLAM, même en l’absence d’estimation de la dérive. Cela permet d’effectuer des fermetures de boucle ou encore d’intégrer des informations géo-référencées de manière naturelle tout en conservant l’intégrité de la solution. En multivéhicule, cet aspect est un point clef puisque chaque véhicule dérive différemment des autres. Il est donc important de le prendre en compte. Enfin, le SLAM a été étendu à plusieurs véhicules. Une structure générique a été prévue afin que notre approche monoculaire puisse être remplacée par n’importe quel algorithme de SLAM. Notre architecture décentralisée évite la consanguinité des données (le fait de compter deux fois une même information) et gère les défaillances réseau, que cela soit des ruptures de communication ou encore des latences dans la réception des données. La partie statique du modèle de dérive permet également de prendre en compte le fait que les positions initiales des véhicules d’une flotte puissent être inconnues. L’intégrité est ainsi maintenue en permanence. Enfin, notre approche étant entièrement décentralisée, elle a pu être testée et validée en simulation et avec des expérimentations réelles dans diverses configurations (convoi en colonne ou en ligne, avec 2 ou 3 véhicules). / The localization of a vehicle with the use of SLAM techniques (Simultaneous Localization And Mapping) has been extensively studied during the last 20 years. However, only a few approaches have tried to extend these algorithms to a fleet of vehicles despite the many potential applications. It is the objective of this thesis. First of all, a monocular SLAM for a single vehicle has been developed. This one proposes to pair an Extended Kalman Filter with a Cartesian representation for landmarks so as to produce accurate low density maps. Indeed, the extension of SLAM to several vehicles requires permanent communications inside the fleet. With only a few landmarks mapped, our approach scales nicely with the number of vehicles. Cheap sensors have been favored (a single camera and an odometer) in order to spread more easily the use of multi-vehicle applications. Correctives have been proposed in order to avoid the divergence problems induced by such a scheme. The experiments showed that our SLAM is able to furnish good localization results while being light and fast.The drift affecting every SLAM algorithm has also been studied. Its integration inside the SLAM process, thanks to a dedicated architecture and a dynamic model, allows to ensure consistency even without an estimation of it. Loop closures or the integration of geo-referenced information becomes straightforward. They naturally correct all the past positions while still maintaining consistency. In a multi-vehicle scenario, it is a key aspect as each vehicle drifts differently from one another. It is consequently important to take it into account. Our SLAM algorithm has then been extended to several vehicles. A generic structure has been used so as to allow any SLAM algorithm to replace our monocular SLAM. The multi-vehicle architecture avoids data incest (double-counting information) and handles network failures, be they communication breakdowns or latencies when receiving data. The static part of the drift model allows to take into account the fact that the initial positions of the different vehicles composing the fleet might be unknown. Consistency is thus permanently preserved. Our approach has been successfully tested using simulations and real experiments with various settings (row or column convoy with 2 or 3 vehicles) in a fully decentralized way.