京都大学 / 0048 / 新制・課程博士 / 博士(理学) / 甲第20954号 / 理博第4406号 / 新制||理||1633(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 沼田 英治, 准教授 森 哲, 教授 中川 尚史 / 学位規則第4条第1項該当 / Doctor of Science / Kyoto University / DFAM

No description available.

No description available.

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.

No description available.

No description available.

Informed traders trade options on underlying securities to lower transaction costs and increase financial leverage for price trend and variance strategies. Options markets play a significant role in price discovery by incorporating private information about future prices for an underlying security into option prices. I generate a new model-free volatility measure to calculate the "distance from arbitrage bounds" from minute-by-minute option series for the S&P 500 index and 30 individual underlying stocks. These iron butterfly arbitrage bounds (IBBs) use intraday call and put option prices from the Bloomberg database. Narrow and wide IBBs are expected to reveal the options market valuation of volatility by market participants. Data series is gathered by using successive one-minute intervals from the Bloomberg database. The data comprise the most recent bid and ask option prices and volumes. I collect S&P 500 index values and index options and use 30 underlying stock prices and option prices for the contracts that have the largest option trading volume during the sampling interval. These bid and ask prices reflect the information generated by intraday price pressures implied by S&P 500 index options or stock options. Consistent with the option micro-structure literature, I find that the IBB measure for actively traded stock options attains its highest level immediately after the open of the market, declines steadily throughout the first trading hour and remains relatively stable until market close. However, index IBBs behave differently. S&P 500 index option IBB attains its lowest level during the first hour of the trading day, then increases and remains relatively stable until market close. I present new evidence regarding the dynamic relation between stock returns and innovations in expected volatility by using the minute-by-minute change in implied volatility (IV) as a proxy. Unlike the relationship between individual stock returns and their respective changes in implied idiosyncratic volatility, I find that all the coefficients on the market volatility index (VIX) term are negative and significant. Therefore, the evidence supports the explanation that the negative relationship between stock returns and expected volatility innovations is primarily related to the systematic component of the expected volatility. I also test whether narrow and wide IBB values capture incremental information to explain the return-volatility relationship. Results indicate that neither narrow IBB nor wide IBB values provide additional information beyond that provided by VIX and IV. The results are robust to five-minute and ten-minute sampling frequencies.

Thesis (MSc)--Stellenbosch University, 2013. / Please refer to full text to view abstract.

Heliconius butterflies exhibit Müllerian mimicry, in which two or more unpalatable species share a mutual advantage from having a common conspicuous colour pattern. These tropical butterflies have impressive visual signals, which are under conflicting selection pressures, as they are used in choosing potential mates and defending against visual predators through aposematic coloration. As both selection pressures are likely to be strong, different elements of the signal might be adapted for different receivers. Here, I combine sensory ecology with behavioural ecology to explain Heliconius colours signals of different co-mimic pairs. I explore how mimicry in Heliconius is perceived both from the perspective of predators and conspecifics, using visual abilities of both butterflies and birds. The different visual sensitivities of avian predators, H. erato females and males make them to perceive Heliconius coloration in different ways. My work suggests that having the ability to see in the ultra-violet light range enables higher discrimination between co-mimics both for birds and butterflies. Heliconius warning colours transmit a consistent signal across time of the day and habitat in a tropical forest for avian vision. In contrast through Heliconius vision there is evidence that patterns are more conspicuous in their own habitats. All these traits could facilitate communication between co-mimics and reduce the cost of confusion in courtship while still maintaining the advantages of Müllerian mimicry against predation. I conducted a field experiment to show that attack rates on a novel distasteful butterfly reduced over time, suggesting that Heliconius wing colouration can enhance aversion among predators. Finally, I have shown that Heliconius butterflies use leaf shape as a cue to approach their host plants, demonstrating the potential for Heliconius to drive negative frequency dependent selection on the leaf shape of their Passiflora host plants. Overall these results highlight ecological interactions between Heliconius butterflies, their predators and host plants.

Les travaux effectués dans le cadre de la présente thèse concernent l'analyse et les améliorations apportées à la transformée de Hough Standard (SHT), utilisée en traitement d'image comme simple outil de détection de segments de lignes droites. La transformée de Hough a reçu, depuis sa proposition en 1962, une attention particulière de la part de la communauté. La HT est considérée comme une méthode robuste, dont le principe repose sur la transformation le problème initial de détection de segments de lignes droites en un problème de section de sommets dans l'espace des paramètres, appelé aussi espace HT ou espace de Hough. Les points candidats dans l'espace image sont mis en correspondance points dans l'espace de Hough, en utilisant Le principe avancé par la transformée de Hough est qu'il existe un nombre infini de lignes qui passent par un point, dont la seule différence est l'orientation (l'angle). La transformée de Hough permet de déterminer lesquelles de ces lignes passent au plus près du domaine d'intérêt. Les cellules dans l'espace de Hough échantillonné obtiennent des votes des points candidats. Les maxima locaux, correspondant aux sommets sont construit lorsque les cellules considérées obtiennent plus de votes que les cellules voisines. Les sommets détectés alors dans l'espace des paramètres sont transformée dans l'espace image pour validation. Malheureusement, les opérations les opérations de transformation directe, de l'espace image vers l'espace des paramètres, et inverse engendrent des opérations d'approximation, ce qui est la source de plusieurs problèmes de la transformée de Hough, qui affectent les aspects de robustesse, précision et résolution. On se propose de résoudre ces problèmes dans le cadre des travaux engagés dans le cadre de la thèse. Les contributions, détaillées ci-dessous, ont pu être proposées. A) Pour adresser le problème de limitation en termes de résolution de la SHT, les points concernent la sélection d'une bonne résolution, l'extension de la résolution de la SHT et l'utilisation des techniques de super-résolution pour la HT ont été couverts et de nouvelles propositions ont été faites et qui sont d'une utilité certaine pour les applications de traitement d'image.- la relation entre la performance de la HT et la résolution est proposée, ce qui permet de garantir le bon choix.- Une technique de super-résolution ets proposée en s'appuyant sur le principe de la HT- Une auto-similarité dans les échantillons HT a été découverte et a été utilisée pour obtenir une résolution supérieure de la HT avec un grande fidélité. B) Pour adresser le problème de la précision de la SHT, les erreurs de la HT ont été analysées, lorsque l'on fait subir des transformations géométriques à l'image source. Les erreurs ainsi détectées ont été utilisées pour compenser le manque de précision de la SHT, aboutissant ainsi à une HT plus précise. Afin de permettre l'évaluation de performance des approches proposées dan sel cadre de la thèse, une transformée de Hough idéale est proposée comme référence / The thesis addresses the improvements of the Standard Hough Transform (SHT) for image processing applications. As a common tool for straight line segment detection, the Hough Transform (HT) has received extensive attention since its proposal in 1962. HT is robust since it converts the straight line detection problem to a peak seeking problem in the parameter space (also called HT space or Hough space). Feature points in the image space are mapped to the parameter space, according to the normal formulation of the possible straight lines crossing them. The cells in the digitalised parameter space obtain votes from the feature points. The local maxima, corresponding to peaks are built when corresponding cells obtain more votes than the ones around them. The peaks detected in the parameter space are then mapped back to the image space for validation. Unfortunately, when mapping feature points in the image space to the parameter space in conjunction with the voting process, rounding operations are employed, which leads to several problems of HT. The robustness, accuracy and resolution are all affected. This thesis aims to solve these problems, and the following contributions were made towards this goal : A) Because of the resolution limitation of SHT, the topics of how to select a “good” resolution, how to extend the resolutions of SHT and how to employ the super-resolution technique in HT are covered. In the research of these topics, several outputs are obtained, which are helpful to image processing applications. These include:- The map of HT performance versus resolutions is drawn, according to which “good” choices of resolutions can be found.- HT resolutions are extended by geometrical analysis of the HT butterflies.- Super resolution HT is proposed with consideration to the features of HT.- Self-similarity of the HT butterflies is discovered and employed to obtain high resolution HT with high reliability. B) For the accuracy defect of SHT, the error system of HT is studied when the image is shifted in the image space. The detection errors are employed to compensate for the defect, and an accurate HT is proposed. In order to evaluate existing HT varieties, an ideal HT is proposed as a standard