Studies have shown that composition and L2 writing teachers give different scores (Golombek, Weigle, Boldt, & Valsecchi, 2003) and focus on different features (Brown, 1991) when assessing student writing, which is assumed to be due to the differences in their background and training (Santos, 1992; Atkinson & Ramanathan, 1995). Error gravity is thought to be one reason why composition and L2 writing teachers give different scores (Rifkin & Roberts, 1995). Common methods for examining error gravity were to analyze scores and responses given by the raters and to have raters reflect on the rating process and analyze their responses. Only one study had used eye-tracking methodology to explore the raters’ reading behaviors (Eckstein, Briney, Chan & Blackwell, 2018). The current study built on Eckstein et al.’s study to examine how composition and L2 writing teachers rate grammar errors differently. The researchers identified three native-like errors and three nonnative-like errors and introduced them into eight paragraphs written by students in a first-year composition class. The researchers asked composition and L2 writing teachers to read and assess the eight paragraphs while an eye-tracker measured their eye-movements. We assume that what raters look at while assessing the paragraphs reflects what they are cognitively processing (Rayner, 1998). The results indicate that composition and L2 writing teachers assign significantly different scores to grammar (L2 writing teachers assign higher scores), yet their reading behaviors are similar. This indicates that teachers with different backgrounds do not process grammar errors differently, but rather reach different scores based on other differences.

La présente thèse, intitulée ``Investigations on electric-magnetic duality in gravity and higher spin theories'', constitue un étude sur la dualité dans les théories de la gravitation et de spins élevés dans le cadre des symétries cachées qui apparaissent après la réduction dimensionnelle de la Relativité Générale et la Supergravité. Elle a comme but de clarifier, en utilisant le formalisme Hamiltonien, la relation entre le graviton et son champ dual (en général, un tenseur de symétrie mixte (D-3,1)) en dimension abitraire, ainsi que la recherche de la généralisation de la symetrie de dualité, par méthodes identiques, aux théories de champs de spin élevé et l'exploration du comportement des champs fermioniques sous l'action de la dualité. La thèse est divisé en cinq chapitres. Le premier chapitre constitue une introduction au sujet des dualités et symétries cachées dans les théories de l'electromagnetisme, la gravitation et la supergravité. Le deuxième chapitre est dédié à l'étude de la dualité dans la gravité linéarisée à dimension D=4: d'abord, on rappelle comment résoudre les contraintes du formalisme Hamiltonien en termes de deux prépotentiels et la forme que l'action prenne après cette résolution. De plus, on reformule l'action en termes de certaines tenseurs invariantes de jauge et trouve une expression non-locale de l'action en termes de deux métriques. En outre, on établisse l'estructure des equations de mouvement covariantes comme une condition de ``twisted self-duality'' et vérifie qu'elles sont equivalentes à un sous-ensemble de celles-ci qui ne contient pas des dérivées temporelles de deuxième ordre. Ce sous-ensemble est aussi obtenu comme les equations de mouvement qui se derivent de l'action écrite en termes des prépotentiels. Dans le troisième chapitre, on généralise cette construction ci-dessus à dimension arbitraire D, où le champ dual du graviton est décrit par un tenseur de symétrie mixte (D-3,1): les contraintes sont résolues en termes de prépotentiels, qu'on utilise afin de construire une action locale, pour finalement obtenir son expression non-locale en termes du graviton et son champ duel. Dans le dernier chapitre, on étudie l'extension de la dualité au système de l'hypergravité linéarisée: la contrainte fermionique est résolue, et les transformations de supersymétrie pour les prépotentiels sont obtenues, ainsi que l'action de la dualité sur les champs fermioniques. / Option Physique du Doctorat en Sciences / info:eu-repo/semantics/nonPublished

The AdS/CFT correspondence is one of the most important discoveries in theoretical physics in recent years. It states that certain quantum mechanical theories can actually be described by classical gravity in one higher dimension, in a spacetime called anti-de Sitter (AdS) space. This means that to compute any measurable quantity in the quantum theory, we can instead do a computation in classical general relativity, and vice versa. What makes this duality so useful is that it relates theories with weak coupling to theories with strong coupling and thus provides a new tool for tackling strongly coupled quantum field theories, which are notoriously difficult to handle using conventional methods. Originally discovered in the context of string theory, this duality has now found a wide range of applications, from condensed matter physics to high temperature plasmas in quantum chromodynamics (QCD).During the course of my PhD I have mostly studied time dependent processes, in particular thermalization processes, in quantum field theories using the AdS/CFT correspondence. On the gravity side, this is dual to dynamical formation of black holes from the collapse of matter fields. By studying the gravitational collapse process in detail, we can then draw conclusions about the dynamical formation of a thermal state in the dual quantum field theory. Certain quantum field theories (such as QCD) enjoy a property called confinement, which in the case of QCD states that quarks can not be isolated. Using mostly numerical methods, I have studied how confinement affects thermalization in quantum field theories. We found that sometimes the system never thermalizes and field theory observables undergo interesting quasiperiodic behaviour. In another line of research, I have studied formation of black holes in three dimensions which due to the simplified nature of three-dimensional gravity can be done using analytical methods. This has led to the discovery of new solutions of three-dimensional gravity corresponding to the formation of black holes without spherical symmetry, which can provide a deeper understanding of thermalization in two-dimensional quantum field theories. In a third line of research, I have studied higher spin gravity in three dimensions, an exotic extension of three-dimensional gravity which includes fields with spin higher than two, and found a new method to construct black hole solutions carrying higher spin charge. / Doctorat en Sciences / info:eu-repo/semantics/nonPublished

This thesis explores metric properties of Liouville quantum gravity (LQG), a random geometry with conformal symmetries introduced in the context of string theory by Polyakov in the 80’s. Formally, it corresponds to the Riemannian metric tensor “e^{γh}(dx² + dy²)” where h is a planar Gaussian free field and γ is a parameter in (0, 2). Since h is a random Schwartz distribution with negative regularity, the exponential e^{γh} only makes sense formally and the associated volume form and distance functions are not well-defined. The mathematical language to define the volume form was introduced by Kahane, also in the 80’s. In this thesis, we explore a renormalization approach to make sense of the distance function and we study its basic properties.

This paper aims to explore the relationship between China's investment in Central and Eastern European countries (CEECs) and China-CEECs trade. Since the 1950s, the research on the relationship between foreign direct investment (FDI) and foreign trade has become one of the topics of theoretical and empirical analysis. Many scholars have conducted extensive studies on the relationship between FDI and trade from different perspectives and theoretical and empirical perspectives. Under the background of "the Belt and Road", the CEECs, as important trading partners in this strategy, have gradually expanded their trade with China. This paper explores the current situation and characteristics of China's direct investment and trade with the CEECs from the perspective of the relationship between FDI and foreign trade. The development of China's direct investment and trade with the CEECs is explored from the perspectives of total volume, country, and products by qualitative analysis. Meanwhile, the trade gravity model is established to empirically analyze the influence of China's direct investment in the CEECs on China-CEECs trade scale from the three aspects of total trade volume, export, and import. The results show that China's direct investment in the CEECs has a long-term positive effect on the scale of...

Simulations of the circulation in the middle atmosphere during northern winter performed with a nonlinear, mechanistic, global circulation model show that the upper mesospheric jet is greatly overestimated and also the position with respect to latitude and height does not correspond to observations. Apart from that also the winter wind reversal in the mesopause region, evoked by breaking gravity waves (GWs), is located too low around 80km, but is observed to be usually around 100 km. These discrepancies are planned to be eliminated by modifying the distribution of GW amplitudes driving the GW parameterization. This distribution is currently based on potential GW energy data derived from GPS radio occultation measurements and has to be replaced by a distribution based on momentum flux estimates applying midfrequency approximation. The results show a weaker mesospheric jet more realistically tilted towards lower latitudes with height. Also the meridional circulation extending from the summer to the winter pole decelerates and less GWs are propagating into the mesosphere. By additionally varying the GW amplitudes in magnitude and time, the wind reversal is shifted upwards and the mesospheric jet is slowed down. / Simulationen der Zirkulation der mittleren Atmosphäre während des nordhemisphärischen Winters unter Verwendung eines nicht-linearen mechanistischen globalen Zirkulationsmodells ergaben beim Vergleich mit Messungen, dass der simulierte, mesosphärische Jet stark überschätzt wird und dessen Position von den Beobachtungen abweicht. Die in der Mesopausenregion einsetzende Windumkehr, hervorgerufen durch brechende Schwerewellen, befindet sich in etwa 80 km anstatt in 100 km. Diese Diskrepanzen sollen eliminiert werden. Hierfür wird die Verteilung der Schwerewellenamplituden, die die Schwerewellenparametrisierung innerhalb des Modells antreibt, am oberen Rand der Troposphäre modifiziert. Diese basiert derzeit auf global beobachteten, zonal gemittelten Daten der potentiellen Energie von Schwerewellen abgeleitet aus GPS Radiookkultationsmessungen und soll durch eine auf Impulsflüssen basierende Verteilung ersetzt werden. Das Modellexperiment zeigt, dass der mesosphärische Jet mit der Höhe in Richtung niedriger Breiten geneigt ist und abgebremst wird. Zudem schwächt die Meridionalzirkulation vom Sommer- zum Winterpol leicht ab und weniger Schwerewellen dringen bis in die Mesosphäre vor. Zusätzlich wird durch zeitliche und unterschiedlich starke Variation der Schwerewellenamplitude die Windumkehr verlagert und der mesosphärische Jet abgebremst.

Having the ability to predict enrollment is an important task for any school's recruiting team. The purpose of this study was to identify significant factors that can be used to predict the spatial distribution of enrollments. As a case study, we used East Tennessee State University (ETSU) pharmacy school, a regional pharmacy school located in the Appalachian Mountains. Through the application of a negative binomial regression model, we found that the most important indicators of enrollment volume for the ETSU pharmacy school were Euclidean distance, probability (based on competing pharmacy schools' prestige, driving distance between schools and home and tuition costs), and the natural barrier of the Appalachian Mountains. Using these factors, together with other control variables, we successfully predicted the spatial distribution of enrollments for ETSU pharmacy school. Interestingly, gender also surfaced as a variable for predicting the pharmacy school's enrollment. We found female students are more sensitive to the geographic proximity of home to school.

Global analyses of gravity wave activity in the stratosphere are presented for the first time using German Low Earth Orbit (LEO) satellite CHAMP. Temperature profiles obtained from CHAMP/GPS radio occultations are first compared with ground based instruments. In general, good agreement is found between these different techniques. Monthly mean Ep values of potential energy, Ep values, being a measure of gravity wave activity, which is estimated with radiosonde observations are compared with CHAMP/GPS data and found that radiosonde observed Ep values are higher than those estimated with radio occultations. There exists a strong diurnal variation of gravity wave activity. From the global morphology of gravity wave activity, large values Ep are noticed even at mid latitudes during winter months besides the tropical latitudes but not during equinoxes suggesting that wave activity, especially at stratospheric heights, is not only modulated due to orography (mountain/lee waves) but mainly depends on seasonal variations at respective latitudes. Latitudinal and vertical variation of gravity wave activity reveals the existence of large Ep values below 25 km and low values in between 25 and 30 km in all the seasons near equator. During southern hemisphere winter, large values are noticed. During equinoxes, these values are nearly same between northern and southern hemispheres (NH and SH) at mid-latitudes. During the months of solstices, Ep distribution involves a larger hemispheric asymmetry at middle and higher latitudes. Large values of Ep are noticed at SH polar latitudes during Sep-Oct months and the latitude range is wider (±300° latitude in both the hemispheres) with large Ep values in all the seasons except winter. / Zum ersten Mal werden globale Analysen der Schwerewellenaktivität, bestimmt unter Verwendung des CHAMP LEO-Satelliten, vorgestellt. Temperaturprofile der CHAMP/RO-Okkultationen werden zunächst mit bodengestützten Messungen verglichen. Generell ist die Übereinstimmung gut. Monatliche Mittelwerte der potentiellen Energie Ep, die als Maß für Schwerewellenaktivität gilt, wurden aus Radisonden- und CHAMP-Messungen bestimmt, wobei die CHAMP-Daten höhere Werte lieferten. Es existiert eine deutlicher Tagesgang von Ep. Die globale Morphologie der Schwerewellenaktivität zeigt hohe Werte nicht nur am Äquator, sondern auch in mittleren Breiten, dies aber nicht während der Äquinoktien. Dies weist darauf hin, dass Schwerewelleaktivität nicht nur orographisch angetrieben ist, sondern in verschiedenen Breiten vom Jahresgang abhängt. Die Breiten- und Höhenabhängigkeit der Schwerewellenaktivität zeigt zwischen 25 und 30 km niedrige, unterhalb von 25 km hohe Werte von Ep am Äquator. Während des Winters in der Südhemisphäre sind die Werte hoch, während zu den Äquinoktien hohe Werte in mittleren Breiten beider Hemisphären zu finden sind. Während der Solstitien zeigt die Ep-Verteilung stärkere hemisphärische Asymmetrie. Hohe Werte von Ep werden während des südpolaren Frühjahrs gemessen. Der äquatoriale Bereich hoher Varianz ist in allen Jahreszeiten außer im Winter breit (±300°).

In 1920, Rudolf Bach proposed an action based on the square of the Weyl tensor or CabcdCabcd where the Weyl tensor is an invariant under a scaling of the metric. A variation of the metric leads to the field equation known as the Bach equation. In this dissertation, the same action is analyzed, but as a conformal gauge theory. It is shown that this action is a result of a particular gauging of this group. By treating it as a gauge theory, it is natural to vary all of the gauge fields independently, rather than performing the usual fourth-order metric variation only. We show that solutions of the resulting vacuum field equations are all solutions to the vacuum Einstein equation, up to a conformal factor—a result consistent with local scale freedom. We also show how solutions for the gauge fields imply there is no gravitational self energy.

Look up! Travelling over your head in the air are waves. They are present all the time in the atmosphere all over the Earth. Now imagine throwing a small rock in a pond and watching the ripples spread out around it. The same thing happens in the atmosphere except the rock is a thunderstorm, the wind blowing over a mountain, or another disturbance. As the wave (known as a gravity wave) travels upwards the thinning air allows the wave to grow larger and larger. Eventually the gravity wave gets too large – and like waves on the beach – it crashes causing whitewater or turbulence. If you are in the shallow water when the ocean wave crashes or breaks, you would feel the energy and momentum from the wave as it pushes or even knocks you over. In the atmosphere, when waves break they transfer their energy and momentum to the background wind changing its speed and even direction. This affects the circulation of the atmosphere. These atmospheric waves are not generally visible to the naked eye but by using special instruments we can observe their effects on the wind, temperature, density, and pressure of the atmosphere. This dissertation discusses the use of a specialized camera to study gravity waves as they travel through layers of the atmosphere 50 miles above the Andes Mountains and change the temperature. First, we introduce the layers of the atmosphere, the techniques used for observing these waves, and the mathematical theory and properties of these gravity waves. We then discuss the camera, its properties, and its unique feature of acquiring temperatures in the middle layer of the atmosphere. We introduce the observatory high in the Andes Mountains and why it was selected. We will look at the nightly fluctuations (or willy-nillyness) and long-term trends from August 2009 until December 2017. We compare measurements from the camera with similar measurements obtained from a satellite taken at the same altitude and measurements from the same camera when it was used at a different location, over Hawaii. Next, we measure the amount of change in the temperature and compare it to a nearby location on the other side of the Andes Mountains. Finally, we look for a specific type of gravity wave caused by wind blowing over the mountains called a mountain wave and perform statistics of those observed events over a period of six years. By understanding the changes in atmospheric properties caused by gravity waves we can learn more about their possible sources. By knowing their sources, we can better understand how much energy is being transported in the atmosphere, which in turn helps with better weather and climate models. Even now –all of this is going on over your head!