The World Wide Web is the most important information space in the world. With the change of the web during the last decade, today’sWeb 2.0 offers everybody the possibility to easily publish information on the web. For instance, everyone can have his own blog, write Wikipedia articles, publish photos on Flickr or post status messages via Twitter. All these services on the web offer users all around the world the opportunity to interchange information and interconnect themselves with other users. However, the information, as it is usually published today, does not offer enough semantics to be machine-processable. As an example, Wikipedia articles are created using the lightweight Wiki markup language and then published as HyperText Markup Language (HTML) files whose semantics can easily be captured by humans, but not machines.

This work deals with roman building terracotas in the area between Vindobona and Brigetio and along Danubian Limes. The first part describes manufacturing of roman bricks, inscriptions, marks and stamps which are used on them. Second part summarizes finds of roman bricks alongside roman buildings on limes romanus. In the third part is considered metodology of research, also there is a focus on Petrological analyses and support of computer software. In this section are tested new ways of comparing of brickstamps with the help of morphometry and accurate measuerment of the stamps. Last part focuses on production and distribution of building material mainly trough river roads. In the end I calculated needed ammount of building material along with the time of production and the time of transportation to the roman forts.

This paper deals with roman fortifications in Egypt. The main emphasis is laid on roman fortresses on forts. Their descriptions are included in the first part of the paper. Another fortification's elements, history of roman province and mentions of forts in ancient writings, which put the forts in geographical and historical context, are described more shortly. The paper includes a brief part about roman navy too. In the second part of the paper the author tries to point out the functions of forts, development of fortification system, the architectural similarities between forts in Egypt and to find architectural parallels in other parts of Roman Empire.

Diese Arbeit betrachtet einen Mikro-Makro-Übergang für die atomare Kette mit Wechselwirkungen zwischen nächsten Nachbarn, deren Dynamik durch ein nichtlineares aber konvexes Wechselwirkungspotential und durch die Newtonschen Bewegungsgleichungen bestimmt ist. Um einen Mikro-Makro-Übergang zu etablieren, wählen wir eine geeignete Skalierung und lassen die Zahl der Teilchen gegen Unendlich laufen. Dabei steht der Fall mit Temperatur im Vordergrund, so dass auf der makroskopischen Skala mikroskopische Oszillationen beschrieben werden müssen. Nach einer Einführung werden im zweiten Kapitel die Grundlagen der atomaren Kette zusammengefasst, und die wesentlichen Probleme beim Mikro-Makro-Übergang mit Temperatur diskutiert. Dabei wird besonders auf die Skalierung, die mikroskopischen Anfangsdaten und die Beschreibung der mikroskopischen Oszillationen eingegangen. Im dritten Kapitel werden so genannte Traveling-Waves betrachtet: Das sind exakte, hochgradig symmetrische Lösungen der atomaren Kette, die generisch von vier Parametern abhängen, und die als Lösungen von Differenzen-Differentialgleichungen bestimmt werden. Im Einzelnen werden die Existenz von Traveling-Waves, ihre thermodynamischen Eigenschaften und ihre Approximierbarkeit untersucht. Im vierten Kapitel werden modulierte Traveling-Waves betrachtet, mit deren Hilfe dann makroskopische Modulationsgleichungen abgeleitet werden. Diese lassen sich als die Erhaltungssätze für Masse, Impuls, Wellenzahl und Entropie interpretieren. Anschließend wird das Rechtfertigungsproblem diskutiert und für einen Spezialfall auch gelöst. Im fünften Kapitel werden numerische Simulationen von Anfangswertproblemen, unter anderem Riemann--Probleme, ausführlich untersucht, wobei die Strukturuntersuchung der auftretenden mikroskopischen Oszillationen im Vordergrund steht. Es zeigt sich, dass die mikroskopischen Oszillationen in vielen Fällen durch modulierte Traveling-Waves beschrieben werden können. / The subject matter of this thesis is a micro-macro transition for the atomic chain with nearest neighbor interaction. The interaction potential is assumed to be nonlinear but convex, and the dynamics of the chain is governed by Newton''s law of motion. To establish the micro-macro transition we choose an appropriate scaling, and let the number of particles tend to infinity. We mainly concentrate on the case with temperature, and therefore we have to describe microscopic oscillations on the macroscopic scale. We start with an introduction in the first chapter. Afterwards in the second chapter we summarize the basics of the atomic chain, and discuss the most important problems concerning a micro-macro transition with temperature. In particular we emphasize the scaling, the microscopic initial data, and the description of the microscopic oscillations. In the third chapter we consider traveling waves: These are highly symmetric solutions of the atomic chain depending on four parameters, and they result as solutions of difference-differential equations. We study the existence of traveling waves, their thermodynamic properties, and we derive schemes for their approximation. The fourth chapter is devoted to modulated traveling waves, because they allow to derive macroscopic modulation equations. These modulation equations can be interpreted as the macroscopic conservations laws for mass, momentum, wave number and entropy. Afterwards we discuss the justification problem, which is moreover solved for a special example. Within the fifth chapter we investigate several numerical simulations of initial value problems for the atomic chain including some Riemann problems. We mainly focus on the structure of the resulting microscopic oscillations, and we will identify many situations in which the microscopic oscillations can be described in terms of modulated traveling waves.

Diese Arbeit beschäftigt sich mit drei Aspekten der AdS/CFT-Korrespondenz, die alle einen Schritt über die klassische SUGRA-Näherung hinausgehen. Zuerst diskutieren wir den BMN Grenzfall der Korrespondenz und untersuchen insbesondere das Verhalten der quantenfeldtheoretischen Propagatoren. Dabei weisen wir nach, dass die Propagatoren im für den BMN Fall relevanten Hintergrund ebener Wellen semiklassisch (WKB) exakt beschrieben werden. Danach wird im Rahmen der AdS/CFT-Korrespondenz der Grenzfall verschwindender Kopplung der konformen Feldtheorie betrachtet. Zur technischen Vereinfachung geschieht dies für das Beispiel des O(N)-Vektormodells. Dabei wird die OPE der Vierpunktfunktionen so umgeschrieben, dass sie strukturelle Ähnlichkeit mit Witten-Diagrammen einer korrespondierenden Theorie von Strömen mit höherem Spin hat. Außerdem wird das O(N)- Vektormodell bei großem N am wechselwirkenden Infrarot-Fixpunkt untersucht. Im letzten Punkt wenden wir uns schließlich der ursprünglichen AdS/CFTDualität unter Mitnahme der nächstführenden Ordnung der 1/N-Entwicklung zu. Für die Deformationen der CFT durch relevante Doppelspur-Operatoren finden wir bei Zustandssummen und konformen Anomalien exakte Übereinstimmung zwischen direkter und AdS-seitiger indirekter Rechnung. Damit wird ein nicht trivialer Test der Korrespondenz über die SUGRA-Näherung hinaus erbracht. / This thesis deals with three corners of the AdS/CFT Correspondence that lie one step beyond the classical supergravity (SUGRA) approximation. We first explore the BMN limit of the duality and study, in particular, the behavior of field theoretic propagators in the corresponding Penrose limit. We unravel the semiclassical (WKB-) exactness of the propagators in the resulting plane wave background metric. Then, we address the limit of vanishing coupling of the conformal field theory (CFT) at large N. In the simplified scenario of Higher Spin/O(N) Vector Model duality, the conformal partial wave (CPW) expansion of scalar four-point functions are reorganized to make them suggestive of a bulk interpretation in term of a consistent truncated massless higher spin theory and their corresponding exchange Witten graphs. We also explore the connection to the interacting O(N) Vector Model at its infra-red fixed point, at leading large N. Finally, coming back to the gauge theory, we study the effect of a relevant double-trace deformations of the boundary CFT on the partition function and its dual bulk interpretation. We show how the one-loop computation in the Anti-de Sitter (AdS) space correctly reproduces the partition function and conformal anomaly of the boundary theory. In all, we get a clean test of the duality beyond the classical SUGRA approximation in the AdS bulk and at the corresponding next-to-leading 1/N order of the CFT at the conformal boundary.

De nombreuses avancées ont été réalisées en termes de géométries instrumentales, mouvements de travail et procédés de fabrication des limes endodontiques. Cependant, peu de recherches se sont tournées vers l’utilisation d’alliages à mémoire de forme (AMF) autres que le Nickel-Titane (NiTi). Ce travail se propose de développer un instrument endodontique constitué d’un nouvel AMF aux propriétés mécaniques et antimicrobiennes très prometteuses : le CuAlBe monocristallin. Après une première analyse par éléments finis des paramètres géométriques adéquats pour une lime endodontique en AMF monocristallin à base de CuAlBe, plusieurs prototypes ont été fabriqués puis testés en rotation continue selon un protocole de pénétration / retrait (P/R) dans des canaux artificiels. Des limes endodontiques en NiTi, déjà commercialisées, ont été également testées avec le même protocole. L’objectif de ces recherches était de montrer que les instruments endodontiques en CuAlBe monocristallin présentaient des performances mécaniques équivalentes à ceux en NiTi, en plus de leurs propriétés antimicrobiennes / Many advances have been made in terms of instrumental geometry, working motion and manufacturing processes of endodontic files. However, since the discovery of Nickel-Titanium (NiTi) shape memory alloys (SMA), few research has been carried out on new SMAs. In this context, this work aims to develop an endodontic instrument machined from a new SMA with very promising mechanical and antimicrobial properties: the single crystal CuAlBe. Following a finite element analysis in order to determine adequate geometric parameters for a single crystal CuAlBe SMA endodontic instrument, prototypes were machined and tested following a continuous rotation penetration / removal (P/R) protocol in artificial canals. Endodontic files made of NiTi SMA, already commercialized, were also tested with the same protocol. The aim of this researches is to show that CuAlBe endodontic instruments could lead equivalent mechanical performances to NiTi instruments in addition of their antimicrobial properties

La navigation sur l’arc atlantique à l’époque romaine est un sujet immense qui pâtit encore trop souvent de l’avis sceptique de chercheurs obnubilés par la Méditerranée. Il a donc fallu détricoter le mythe de l’océan infranchissable par l’étude approfondie des éléments interdépendants constitutifs de la navigation fluvio-maritime et moteurs de l’économie de l’arc atlantique, à savoir : l’amer, le navire et le port. Aussi l’étude de l’organisation du commerce atlantique sur les voies fluviales et maritimes, de La Corogne à Boulogne-sur-Mer, a-t-elle abouti à l’établissement d’une typologie « atlantique » tripartite. / Navigation in the Atlantic arc – enlarged to the English Channel and the North Sea – in Roman period, is a vast topic that, too often, still suffers from the sceptical opinion of researchers obsessed with the Mediterranean. It has been necessary to unravel the myth of the impassable Ocean, by means of a deep study of the mutually dependent elements forming the maritime and fluvial navigation and driving force of the Atlantic arc economy: the landmark, the vessel and the harbour. Moreover, the study of the organization of the Atlantic trade through the maritime and fluvial routes, from A Coruña to Boulogne-sur-Mer, have result in the establishment of a three-party ‘Atlantic’ typology.

In this thesis I investigate several aspects of local quantum criticality, a concept of key importance in a number of physical contexts ranging from critical heavy fermion compounds to quantum dot systems. Quantum critical points are associated with second order phase transitions at zero temperature. In contrast to their finite-temperature counterparts, the zero-point motion cannot be neglected near a quantum critical point. As a result, the incorporation of quantum dynamics leads to an effective dimension larger than the spatial dimension of the system for the order parameter fluctuations within the Ginzburg-Landau-Wilson treatment of criticality. This so-called quantum-to-classical mapping works well for the critical properties in insulating systems but apparently fails in systems containing gapless fermions. This has been experimentally most clearly been demonstrated within a particular class of intermetallic compounds called heavy fermions. A particular way in which the Ginzburg-Landau-Wilson paradigm fails is for critical Kondo destruction that seems to underlie the unconventional quantum criticality seen in the heavy fermions. I focus on studying the properties of critical Kondo destruction and the emergence of energy-over-temperature-scaling in systems without spatial degrees of freedom, i.e., so-called quantum impurity systems. In particular, I employ large-N techniques to address critical properties of this class of quantum phase transitions in and out of equilibrium. As quantum critical systems are characterized by a scale-invariant spectrum with many low-lying excitations, it may appear that any perturbation can lead to a response beyond the linear response regime. Understanding what governs the non-linear response regime near quantum criticality is an interesting area. Here, I first present a path integral version of the Schrieffer-Wolff transformation which relates the functional integral form of the partition function of the Anderson model to that of its effective low-energy model. The equivalence between the low-energy sector of the Anderson model in the Kondo regime and the spin-isotropic Kondo model is usually established via a canonical transformation performed on the Hamiltonian, followed by a projection. The resulting functional integral assumes the form of a spin path integral and includes a geometric phase factor, i.e. a Berry phase. The approach stresses the underlying symmetries of the model and allows for a straightforward generalization of the transformation to more involved models. As an example of the efficiency of the approach I apply it to a single electron transistor attached to ferromagnetic leads and derive the effective low-energy model of such a magnetic transistor. As Kondo screening is a local phenomenon, it and its criticality can be studied using the appropriate impurity model. A general impurity model to study critical Kondo destruction is the pseudogap Bose-Fermi Kondo model. Here, I concentrate on the multi-channel version of the model using the dynamical large-N study. This model allows to study the non-trivial interplay between two different mechanisms of critical Kondo destruction. The interplay of two processes that can each by itself lead to critical Kondo destruction. The zero-temperature residual entropy at various fixed points for the model is also discussed. The two channel Anderson model exhibits several continuous quantum phase transitions between weak- and strong-coupling phases. The non-crossing approximation (NCA) is believed to give reliable results for the standard two-channel Anderson model of a magnetic impurity in a metal. I revisit the reliability of the NCA for the standard two channel Anderson model (constant conduction electron density of states) and investigate its reliability for the two-channel pseudogap Anderson model. This is done by comparing finite-temperature, finite-frequency solutions of the NCA equations and asymptotically exact zero-temperature NCA solutions with numerical renormalization-group calculations. The phase diagram of this model is well established. The focus here will be on the dynamical scaling properties obtained within the NCA. Finally, I study the thermal and non-thermal steady state scaling functions and the steady-state dynamics of the pseudogap Kondo model. This model allows us to study the concept of effective temperatures near fully interacting as well as weak-coupling fixed points and compare the out-of-equilibrium scaling properties of critical Kondo destruction to those of the traditional spin-density wave (SDW) scenario. The differences I identify can be experimentally probed. This may be helpful in identifying the nature of the quantum critical points observed in certain heavy fermion compounds.

Cette thèse a pour objet de mener une réflexion sur les différentes fonctions entre la frontière de Germanie supérieure et celle de Germanie, en insistant plus particulièrement sur sa dimension militaire et sa place dans la stratégie de défense de l’Empire. L’étude de ce limes est particulièrement intéressante des Sévères à Dioclétien, car c’est une période où il connaît de nombreuses transformations et adaptations jusqu’à son abandon et le retour sur la 'ripa ' du Rhin. Après avoir défini le limes et ses fonctions, nous verrons que les échanges y sont limités entre le monde romain et germanique et qu’il est efficace pour lutter contre les raids de faible intensité. Son abandon s’explique à la fois par les guerres civiles et par les mutations dans le monde germanique. Après l’unité retrouvée de l’Empire, les empereurs créent une nouvelle ligne de défense sur le Rhin qui est complétée par la création d’un Etat-tampon, l’Alamannia. / This thesis aims to reflect on the different functions between the upper border of Germany and that of Germany, with particular emphasis on its military dimension and its place in the Empire defense strategy. The study of the limes is particularly interesting from the Severi to Diocletian, because this is a period when it has many changes and adjustments to its abandonment and the return on the 'ripa' the Rhine. After defining the limes and its function, we will see that trading is limited between the Roman and Germanic world and that effective against low-intensity raids. Its abandonment is explained both by civil wars and by changes in the Germanic world. After the rediscovered unity of the Empire, the emperors created a new line of defense on the Rhine which is complemented by the creation of a buffer state, the Alamannia.

Das Wechselspiel zwischen String- und Eichtheorien hat in den letzten Jahren zu vielen neuen Einsichten geführt. Das herausragendste Beispiel ist die sogenannte AdS/CFT Korrespondenz, eine Dualität zwischen Stringtheorien auf Anti-de Sitter-Räumen (AdS) und konformen Eichtheorien auf deren Rand. Die Untersuchung von Stringtheorie auf ebenfrontigen Gravitationswellen, die sich im sogenannten Penrose-Limes aus AdS-Raumzeiten gewinnen lassen, erlaubt es, diese Dualität über die niederenergetische Supergravitationsnäherung hinausgehend zu überprüfen. Verallgemeinerte ebenfrontige Gravitationswellen sind auch für sich gesehen interessant, da sie eine grosse Klasse von Raumzeiten bilden, die exakte klassische Lösungen der Stringtheorie sind. In dieser Arbeit werden Aspekte der Stringtheorie auf ebenfrontigen Gravitationswellen untersucht. Besonderes Interesse gilt dabei der Verbindung dieser Stringtheorien zu Eichtheorien. Wechselwirkungen von Strings in derjenigen Gravitationswellen-Raumzeit mit maximaler Supersymmetrie werden im Rahmen der Lichtkegel-Stringfeldtheorie behandelt. Viele Ergebnisse, die für den Fall der flachen Minkowski-Raumzeit bekannt sind, werden dabei vollständig auf die komplizierteren ebenfrontigen Gravitationswellen verallgemeinert. Die führenden nicht-planaren Korrekturen zu den anomalen Dimensionen von Operatoren in der Eichtheorie, die eine duale Beschreibung von Stringzuständen liefern, werden innerhalb der Lichtkegel-Stringfeldtheorie reproduziert. / The interplay between string and gauge theory has led to many new insights in recent years. The most prominent example is the AdS/CFT correspondence, a duality between string theory on Anti-de Sitter (AdS) spaces and conformal gauge theories defined on their boundary. The study of string theory on plane wave backgrounds, which are connected to AdS by the Penrose limit, opens up the possibility of testing this duality beyond the low-energy supergravity approximation. Generalized plane wave geometries are interesting in themselves, as they provide a large class of exact classical space-time backgrounds for string theory. In this thesis aspects of string theory on plane wave backgrounds are studied, with an emphasis on the connection to gauge theory. String interactions in the plane wave space-time with maximal supersymmetry are investigated in the framework of light-cone string field theory. In the process, many results that had been found for the case of flat Minkowski space-time are generalized to the more complex plane wave background. The leading non-planar corrections to the anomalous dimensions of gauge theory operators dual to string states are recovered within light-cone string field theory.