La correspondance AdS/CFT est la première réalisation précise de la dualité jauge/gravité. Jusqu’à maintenant la correspondance AdS/CFT reste une conjecture. La dualité de N = 4 SYM et la théorie des cordes est un exemple le plus notable de correspondance AdS/CFT. Un des obstacles principaux à l’explorer est le fait que le régime de couplage faible pour la théorie de jauge est le régime de couplage fort pour la théorie des cordes et vice versa. Par conséquent, aussi longtemps que les méthodes perturbatives sont appliquées, on ne peut pas comparer les observables de deux cotés de la correspondance directement en dehors de quelques cas particuliers. A ce stade, l’énorme symétrie de N = 4 SYM joue un rôle important en permettant le calcul exact des observables de la théorie au moins dans la limite planaire. Cette thèse est consacrée au calcul des fonctions à trois, l’un des principaux observables de N = 4 SYM, et est composée de deux parties. Dans la première partie nous considérons l’approche générale pour le calcul des fonctions à trois points sur la base de soi-disant vertex de spin, qui est inspiré de la théorie de champs des cordes. Dans la deuxième partie, nous considérons un type spécifique de fonctions à trois points appelés lourd-lourd-léger, qui sont caractérisés par la propriété que la longueur de l’un des opérateurs est beaucoup plus petite des longueurs de deux autres. Il s’avère que ces fonctions de corrélations peuvent être identifiées à des facteurs de forme diagonaux et ainsi on peut appliquer les résultats concernant les facteurs de forme. / N=4 SYM theory has been drawing the attention of a lot of physicists during two last decades mainly due to the two aspects: AdS/CFT correspondence and integrability. AdS/CFT correspondence is the first precise realization of the gauge/string duality whose history starts in the 60's, when a string theory was considered as a candidate for describing the strong interactions. In 1997 Maldacena made a proposal about the duality between certain conformal field theories (CFT) and string theories defined on the product of AdS space and some compact manifold, which implies a one to one map between the observables of the gauge and string counterparts. Up to now AdS/CFT correspondence still remains a conjecture. The duality of N=4 SYM and the appropriate string counterpart is the most notable example of the AdS/CFT correspondence. One of the main obstructions to exploring it is the fact that weak coupling regime for the gauge theory is the strong coupling regime for the string theory and vice versa. Therefore as long as perturbative methods are applied, one can not compare the observables of dual counterparts directly apart from some specific cases. At this point the huge symmetry of N=4 SYM plays an important role allowing exact computation of the theory observables at least in the planar limit. This property of the theory is called integrability. The observables of the N=4 SYM are Wilson loops and correlation functions built out of gauge invariant operators. The space-time dependence of the two- and three-point correlators is fixed by the conformal symmetry up to some parameters: dimensions of the operators in the case of two-point functions and dimensions of the operators and structure constants in the case of three-point functions. It's commonly accepted to refer to the problem of finding the dimensions of the operators as the spectral problem. On the classical level the operator dimension is equal to the sum of the dimensions of the fundamental fields out of which the operator is composed. When the interaction is turned on, the conformal dimension gets quantum correction. In order to compute three-point functions, apart from the conformal dimensions of corresponding operators one needs to compute the structure constants. In CFT computation of the higher-point correlators eventually can be reduced to computation of two- and three-point functions by means of the operator product expansion. Therefore two- and three-point functions appear to be building blocks of any correlator of the theory. This thesis is devoted to computation of three-point functions and consists of two parts. In the first part we consider the general approach for computing three-point functions based on the so-called spin vertex, which is inspired from the string field theory. In the second part we consider a specific kind of three-point functions called heavy-heavy-light, which are characterized by the property that the length of one of the operators is much smaller the lengthes of other two. It happens that this kind of correlators can be considered as diagonal form factors which supposes that in this case one can apply the results obtained in the form factor theory.

Diploma thesis deals with the ADS-B system and its possible use at the Airport Václav Havel in Prague. In the beginning of this thesis there is described the history leading to the introduction of this system and then the ADS-B is explained. In this thesis is also included a schedule for the introduction of the system. Them the application is presented to the airport with integrity verification, functionality, reliability and safety.

This article investigates the effectiveness of bathroom print ads. Using liquor as the product domain, field study data (n = 146) indicate a high level of ad (60%) and product category (80%) recall. Contrary to the literature and the researchers' hypothesis, respondents had a significantly higher level of recall for copy dominant than for visual dominant ads. Hypotheses suggesting that color advertisements would outperform non-color advertisements and interactions between ages and visual-based versus copy-based stimuli and gender and visual-based versus copy-based stimuliwere not supported by the data. The implications for practitioners of the effectiveness of copy rich ads and suggested directions for future research are discussed.

The impact of air travel on the climate, along with its increasing share in CO2 emissions have raised the demand for sustainable air travel solutions. The current aircraft technologies have seen significant improvement throughout the years. Although, the rate at which new aircraft technologies are developed can not keep up with the increased demand for air travel. Hence, a different approach to reduce the aviation’s impact on climate can be achieved by optimizing the vertical flight path in order to reduce the fuel consumption, i.e. using dynamic programming. Upon departure, an optimization of the vertical flight path is initiated and an optimal flight plan is suggested to the flight crew.  The fuel saving produced by the optimal flight plan is a potential saving that can only be fully achieved if the flight crew chose to fly according to the optimized flight path. However, restrictions from the Air Traffic Control, as well as the flight crew’s willingness to follow the optimized flight path can affect the achieved saving. Hence, a tool is developed in order to compute trip fuel consumption from post-flight data obtained from the Automatic Dependent Surveillance-Broadcast (ADS-B) surveillance technology. A method to identify the start and end positions of cruise segments is successfully implemented. Two methods of calculating the fuel are implemented and compared. The first method is based on simulating the actual flight, which uses the same performance model as for the simulation of the operational flight plan trip and optimized trip. The second method is based on utilizing the ADS-B data to obtain the aircraft speed which in return can be used as a parameter to obtain the fuel flow of the aircraft, hence the trip is not simulated. The results reveals that the simulation method produces flight trajectories that are comparable to the operational and optimized flight plans since they use the same model structure. However, using ADS-B data to obtain fuel consumption represents the actual flight trajectory more accurately.  Furthermore, an optimization algorithm based on the onboard Flight Management Computer is implemented. According to the results, the FMC optimization offers a sufficient optimization of the cruise phase, when compared to the OFP trip, however performs worse than the dynamic programming, which provides a global optimal solution. / Flygresornas inverkan på klimatet, tillsammans med dess ökande andel av CO2-utsläppen, har ökat kraven på hållbara flygplanslösningar. Den nuvarande flygplansteknologin har genomgått betydande förbättringar genom åren. Men takten för vilken ny flygplansteknik utvecklas kan inte hålla jämna steg med den ökade efterfrågan på flygresor. Däremot kan ett annat tillvägagångssätt för att minska flygets påverkan på klimatet uppnås genom att optimera den vertikala flygvägen för att minska bränsleförbrukningen, d.v.s. med hjälp av högupplösta väderdata. Vid avgång initieras en dynamisk programmering där optimering av den vertikala flygbanan och en optimal färdplan föreslås för flygbesättningen.  Bränslebesparingen som den optimala färdplanen ger är en besparingspotential som endast kan uppnås fullt ut om flygbesättningen väljer att flyga enligt den. Restriktioner från flygledningen, samt flygbesättningens vilja att följa den optimerade färdplanen kan dock påverka den uppnådda besparingen. Därav utvecklas ett verktyg för att beräkna färdens bränsleförbrukning från postflight data erhållna från Automatic Dependent Surveillance-Broadcast (ADS-B) övervakningsteknologi. En metod för att identifiera start- och slutpositionerna för kryssningssegment implementeras framgångsrikt. Två metoder för att beräkna bränslet implementeras och jämförs. Den första metoden baseras på att simulera den faktiska flygningen. Denna metod använder samma prestandamodell som för simuleringen av den operativa färdplanens resa och den optimerade resan. Den andra metoden baseras på att använda ADS-B-data för att erhålla flygplanets hastighet, som i sin tur kan användas som en parameter för att få fram flygplanets bränsleflöde vid en tidpunkt. Resultaten visar att simuleringsmetoden ger flygbanor som är rättvist jämförbara med de operativa och optimerade flygplanerna, då de använder samma modell. Men att använda ADS-B-data för att få bränsleförbrukning representerar den faktiska flygbanan mer exakt.  Dessutom implementeras en optimeringsalgoritm baserad på den inbyggda Flight Management Computer. Enligt resultaten erhåller FMC-optimeringen en tillfredsställande optimering av kryssningsfasen, jämfört med OFP-resan, men presterar sämre än den dynamiska programmeringen, vilket alltid ger en global optimal lösning.

The Universal Access Transceiver (UAT) is one of the two datalinks available in Automatic Dependent Surveillance Broadcast (ADS-B) system to facilitate air traffic control and flight tracking of small and general-purpose aircraft. By allowing aircraft to be tracked passively through a radio broadcast of the aircraft position and flight information, flight safety can be ensured and air traffic order is maintained. With the ADS-B initiative, surveillance is encouraged to cover not only residential areas but also remote regions where the infrastructure of a radar station is less likely to be available. Hence a passive, low-power, compact and portable device that receives the radio signal and shares the extracted flight information to control center is welcomed so that air traffic control and surveillance to nearby aircraft can be made possible without massive infrastructure cost. The aim of this thesis project is to develop a compact and portable solution of ADS-B UAT receiver using FPGA to demodulate the received UAT signal and extract valid UAT messages from it, as an extensional function to Skysense’s former product of ADS-B 1090ES receiver. The work presented herein mainly focuses on the development of FPGA functions of the receiver which comprises demodulating the digitized UAT signal and extract UAT payload message from the samples. This work demonstrates the design process and implementation of a 978 MHz UAT receiver using Altera Cyclone IV FPGA. The final demonstrated design is capable of demodulating sampled UAT signal and transfer the demodulated raw data bits to a processing unit through UART interface. Simulation result and synthesis report together with analysis are presented. / Universal Access Transceiver (UAT) är en av de två datalänkar som finns tillgängliga i Automatic Dependent Surveillance-Broadcast (ADS-B)-systemet för att underlätta flygkontroll och spårning av små och allmännyttiga flygplan. Genom att tillåta att flygplan spåras passivt genom en radiosändning av flygplanets position och flyginformation kan flygsäkerheten garanteras och flygordningen upprätthållas. Med ADS-B-initiativet uppmuntras övervakningen att inte bara omfatta bostadsområden utan även avlägsna regioner där det är mindre sannolikt att en radarstations infrastruktur är tillgänglig. Därför välkomnas en passiv, energisnål, kompakt och bärbar enhet som tar emot radiosignalen och delar den extraherade flyginformationen till kontrollcentralen så att flygkontroll och övervakning till närbelägna flygplan kan göras möjlig utan enorma infrastrukturkostnader. Syftet med detta avhandlingsprojekt är att utveckla en kompakt och bärbar lösning med ADS-B UAT-mottagare med FPGA som tilläggsfunktion till produkten ADS-B 1090ES-mottagare från företaget Skysense AB. Det arbete som presenteras här fokuserar främst på utvecklingen av FPGA-funktioner hos mottagaren, vilka består av att demodulera den digitaliserade UAT-signalen och extrahera UAT-meddelandet om nyttolast från proverna. Detta arbete visar designprocessen för och genomförandet av en 978 MHz UAT-mottagare med Altera Cyclone IV FPGA. Den slutgiltiga demonstrerade konstruktionen kan demodulera en samplad UAT-signal och överföra de demodulerade rådatabitarna till en behandlingsenhet genom UART-gränssnittet. Simuleringsresultat och sammanfattande rapport presenteras tillsammans.

Integrabilität hat sich als ein mächtiges Werkzeug zur Berechnung von Observablen in der AdS/CFT-Korrespondenz erwiesen. Zunächst für das planare Spektralproblem entdeckt, wurden auch Methoden zur Berechnung von Mehrpunktfunktionen entwickelt. In dieser Arbeit wird diese Korrespondenz für AdS5/CFT4 und AdS3/CFT2 betrachtet mit dem Ziel, den integrablen Formalismus zu erweitern. Teil I behandelt Integrabilität in der N=4 SYM-Theorie, wo der Hexagon-Formalismus die Berechnung von Dreipunktfunktionen ermöglicht. Dazu wird der Korrelator in zwei hexagonale Stücke zerlegt. Die lokalen Operatoren müssen im Spinkettenbild als Bethe-Zustand zerschnitten und ein verschränkter Zustand konstruiert werden. Der Hexagon-Formalismus wird hier auf Sektoren mit höherem Rang erweitert, wobei die operatorartige Struktur erhalten und nur minimale Informationen aus dem geschachtelten Bethe-Ansatz genutzt werden. Weiterhin erlaubt die Betrachtung von Doppelanregungen im Spinkettenbild die Realisierung aller Felder der N=4 SYM-Theorie. Der chirale Yang-Mills-Feldstärketensor wird aus vier Fermionen in führender Ordnung der Kopplung konstruiert, eine Methode zur Einsetzung des Lagrangeoperators im Hexagon-Formalismus wird vorgeschlagen und ein erster Test durchgeführt. Teil II behandelt den Hexagon-Formalismus für Superstrings auf AdS3xS3xT4 Hintergründen mit einer Mischung von Ramond-Ramond und Neveu-Schwarz-Neveu-Schwarz Flüssen. Der Formfaktor wird für Ein- und Zwei-Teilchen-Zustände konstruiert und lässt sich für viele Teilchen unter Nutzung der S Matrix verallgemeinern. Schließlich werden die thermodynamischen Bethe-Ansatz (TBA)-Gleichungen betrachtet, die von Frolov und Sfondrini für das Spektrum von Strings auf reinem Ramond-Ramond AdS3xS3xT4 Hintergrund konstruiert wurden. Bei schwacher Kopplung lassen sich die TBA-Gleichungen erheblich vereinfachen. Der Beitrag zu den anomalen Dimensionen in führender Ordnung ist auf masselose Anregungen zurückzuführen. / Integrability proved to be a powerful tool to calculate observables in the AdS/CFT correspondence. At first discovered in the planar spectral problem, methods have since been devised for calculating higher-point functions as well. In this thesis we will consider two instances of the correspondence, that is AdS5/CFT4 as well as AdS3/CFT2, aiming at extending the integrability framework. In Part I we focus on integrability in N=4 SYM theory, where the hexagon form factor provides a formalism to calculate three-point functions. For this, the correlator is cut into two hexagonal patches. Considering the local operators in the spin chain picture, the Bethe states also need to be cut, resulting in an entangled state. In this thesis, we extend the hexagon formalism to higher-rank sectors, while preserving its operator-like structure and importing a minimum of information from the nested Bethe ansatz. Moreover, considering double excitations in the spin chain picture allows us to accommodate for the full set of fields in N=4 SYM theory. We build the chiral Yang-Mills field strength tensor from four fermions at leading order in the coupling, put forward a Lagrangian insertion method in the hexagon formalism and perform a first test. In Part II we propose a hexagon formalism for superstrings in AdS3×S3×T4 backgrounds with an arbitrary mixture or Ramond-Ramond and Neveu-Schwarz-Neveu-Schwarz fluxes. We bootstrap the hexagon form factor for one- and two-particle states from symmetry and give a proposal for the evaluation of many particle states in terms of the theorie's S matrix. Finally, we consider the thermodynamic Bethe ansatz (TBA) equations constructed by Frolov and Sfondrini for the spectrum of strings on the pure-Ramond-Ramond AdS3×S3×T4 background. Here we study the small tension limit of the mirror TBA equations and find that the equations simplify considerably. We observe that the leading-order contribution to the anomalous dimensions is due to massless excitations.

The impact of air travel on the climate, along with its increasing share in CO2 emissions haveraised the demand for sustainable air travel solutions. The current aircraft technologies haveseen significant improvement throughout the years. Although, the rate at which new aircrafttechnologies are developed can not keep up with the increased demand for air travel. Hence, adifferent approach to reduce the aviation’s impact on climate can be achieved by optimizing thevertical flight path in order to reduce the fuel consumption, i.e. using dynamic programming.Upon departure, an optimization of the vertical flight path is initiated and an optimal flight planis suggested to the flight crew. The fuel saving produced by the optimal flight plan is a potential saving that can only be fullyachieved if the flight crew chose to fly according to the optimized flight path. However, restrictionsfrom the Air Traffic Control, as well as the flight crew’s willingness to follow theoptimized flight path can affect the achieved saving. Hence, a tool is developed in order tocompute trip fuel consumption from post-flight data obtained from the Automatic DependentSurveillance-Broadcast (ADS-B) surveillance technology. A method to identify the start andend positions of cruise segments is successfully implemented. Two methods of calculating thefuel are implemented and compared. The first method is based on simulating the actual flight,which uses the same performance model as for the simulation of the operational flight plantrip and optimized trip. The second method is based on utilizing the ADS-B data to obtain theaircraft speed which in return can be used as a parameter to obtain the fuel flow of the aircraft,hence the trip is not simulated. The results reveals that the simulation method produces flighttrajectories that are comparable to the operational and optimized flight plans since they use thesame model structure. However, using ADS-B data to obtain fuel consumption represents theactual flight trajectory more accurately. Furthermore, an optimization algorithm based on the on-board Flight Management Computeris implemented. According to the results, the FMC optimization offers a sufficient optimizationof the cruise phase, when compared to the OFP trip, however performs worse than the dynamicprogramming, which provides a global optimal solution / Flygresornas inverkan på klimatet, tillsammans med dess ökande andel av CO2-utsläppen, harökat kraven på hållbara flygplanslösningar. Den nuvarande flygplansteknologin har genomgåttbetydande förbättringar genom åren. Men takten för vilken ny flygplansteknik utvecklas kaninte hålla jämna steg med den ökade efterfrågan på flygresor. Däremot kan ett annat tillvägagångssättför att minska flygets påverkan på klimatet uppnås genom att optimera den vertikalaflygvägen för att minska bränsleförbrukningen, d.v.s. med hjälp av högupplösta väderdata. Vidavgång initieras en dynamisk programmering där optimering av den vertikala flygbanan och enoptimal färdplan föreslås för flygbesättningen. Bränslebesparingen som den optimala färdplanen ger är en besparingspotential som endast kanuppnås fullt ut om flygbesättningen väljer att flyga enligt den. Restriktioner från flygledningen,samt flygbesättningens vilja att följa den optimerade färdplanen kan dock påverka denuppnådda besparingen. Därav utvecklas ett verktyg för att beräkna färdens bränsleförbrukningfrån post-flight data erhållna från Automatic Dependent Surveillance-Broadcast (ADS-B) övervakningsteknologi.En metod för att identifiera start- och slutpositionerna för kryssningssegmentimplementeras framgångsrikt. Två metoder för att beräkna bränslet implementeras ochjämförs. Den första metoden baseras på att simulera den faktiska flygningen. Denna metodanvänder samma prestandamodell som för simuleringen av den operativa färdplanens resa ochden optimerade resan. Den andra metoden baseras på att använda ADS-B-data för att erhållaflygplanets hastighet, som i sin tur kan användas som en parameter för att få fram flygplanetsbränsleflöde vid en tidpunkt. Resultaten visar att simuleringsmetoden ger flygbanor somär rättvist jämförbara med de operativa och optimerade flygplanerna, då de använder sammamodell. Men att använda ADS-B-data för att få bränsleförbrukning representerar den faktiskaflygbanan mer exakt. Dessutom implementeras en optimeringsalgoritm baserad på den inbyggda Flight ManagementComputer. Enligt resultaten erhåller FMC-optimeringen en tillfredsställande optimering avkryssningsfasen, jämfört med OFP-resan, men presterar sämre än den dynamiska programmeringen,vilket alltid ger en global optimal lösning.

One of the phenomenal results emerging from string theory is the AdS/CFT correspondence or gauge-gravity duality: In certain cases a theory of gravity is equivalent to a "dual" gauge theory, very similar to the one describing non-gravitational interactions of fundamental subatomic particles. A difficult problem on one side can be mapped to a simpler and solvable problem on the other side using this correspondence. Thus one of the theories can be understood better using the other. The mapping between theories of gravity and gauge theories has led to new approaches to building models of particle physics from string theory. One of the important features to model is the phenomenon of confinement present in strong interaction of particle physics. This feature is not present in the gauge theory arising in the simplest of the examples of the duality. However this N = 4 supersymmetric Yang-Mills gauge theory enjoys the property of being integrable, i.e. it can be exactly solved in terms of conserved charges. It is expected that if a more realistic theory turns out to be integrable, solvability of the theory would lead to simple analytical expressions for quantities like masses of the hadrons in the theory. In this thesis we show that the existing models of confinement are all nonintegrable--such simple analytic expressions cannot be obtained. We moreover show that these nonintegrable systems also exhibit features of chaotic dynamical systems, namely, sensitivity to initial conditions and a typical route of transition to chaos. We proceed to study the quantum mechanics of these systems and check whether their properties match those of chaotic quantum systems. Interestingly, the distribution of the spacing of meson excitations measured in the laboratory have been found to match with level-spacing distribution of typical quantum chaotic systems. We find agreement of this distribution with models of confining strong interactions, conforming these as viable models of particle physics arising from string theory.

We investigate phase transitions in holographic models of QCD. In chapter I, we explore the effect of constant external U(1) fields on the physics of chiral symmetry breaking, as realized in the D3/D7 model. We discover that this model exhibits the phenomenon of magnetic catalysis, which is what one would expect from a weakly coupled field theory intuition. In chapter II, we continue exploring the effect of external U(1) fields but now on the backreacted D3/D7 model, where the backreaction is obtained via a smearing procedure. We again find the magnetic catalysis effect, however the results differ from the previous case depending on the backreaction parameters. In chapter III, we investigate lattices of instantons in the D4/D8 model of chiral symmetry breaking. These instanton lattices can change dimensionality, and in particular we investigate the 1D [right arrow] 2D transition as a simpler case of the more complicated 3D [right arrow] 4D transition which is conjectured to be holographically dual to the baryonic to quarkyonic phase transition. Besides this interpretation, one could also view this as a hypothetical condensed matter system. We have a lattice of instantons dominated by two-body forces, whose interactions depend not only on their mutual distance in physical space but also on their relative orientations in the internal isospace. We obtain a rich variety of instanton crystals whose description could serve to be useful beyond holography. / text

Mobile apps (or apps) are software applications developed to run on mobile devices such as smartphones and tablets, among other devices. The number of apps has grown tremendously since Apple opened the first app store in 2008. For example, in March of 2009 the Google Play app store (formerly known as Android Market) had only 2,300 apps, and by mid of 2013 there were more than 800,000 apps. Given the accelerated rate of growth in the number of apps, new software engineering challenges have emerged in order to help ease the software development practices of app developers. In this thesis we examine three examples of these challenges, namely code reuse in mobile apps, app ratings, and the use of ad libraries within apps. We carry out our case studies on thousands of Android apps from the Google Play market. We find that code reuse in mobile apps is considerably higher than in desktop/server apps. However, identical copies of mobile apps are rare. We find that the current ratings system is not able to capture the dynamics of the evolving nature of apps. Thus, we were able to show the need for a more elaborate rating system for the apps. Finally, we observe that a considerable number of free-to-download apps are dependant on ads for their revenue. Our findings suggest that "ad maintenance" is a tough challenge that developers of mobile apps have to face. / Thesis (Master, Computing) -- Queen's University, 2013-08-04 22:03:54.577