The quality of cameras is currently increasing very fast meanwhile the price of them is decreasing. The possibilities of using a camera as a measurement and navigation instrument are thus getting bigger all the time. This thesis studies the transformation relations between a camera image and the scene in space that is projected to it. A theoretical derivation of the transform will be presented, and methods and algorithms for applications based on the transform will be developed. The above mentioned transform is called the camera matrix, which contains information about the camera attitude, the camera position, and the internal structure of the camera. Useful information for several different applications can be extracted from the camera image with the help of the camera matrix. In one of the applications, treated in this Master´s thesis, the camera attitude is estimated when the camera is calibrated and its position is known. Another application is that of absolute target positioning, where a point in a digital map is searched from its position in a camera image. Better accuracy in the measurements can though be obtained with relative target positioning i.e., estimation of distance and angle between two points in the digital map by picking them out in the image. This is because that the errors of the absolute target positioning for each of the two points are dependent and thus partly will cancel each other out when their relative position and angle is measured.

Dams are important large structures providing vital benefits to human life. These strategic structures are necessary in order to supply water and energy and to control floods. Moreover, dams have important roles in regional development and national economy. Thus, the design of dams deserves rigorous studies. Deterministic approach may be acceptable for design of dams and may satisfy safety requirements if large safety factors are used. However, such an approach will not be cost-effective in economic terms. High safety factors utilized in deterministic approaches necessitates large dimensions. One remedy for this overestimation is integrating statistical information and techniques, such as Monte-Carlo simulations into the analysis and design of dams. Probabilistic approaches may result in more economical and reasonable designs. CADAM is a software program which allows the user to analyze dams using Monte-Carlo simulation technique. Uncertainties associated with tensile strength, peak cohesion, peak friction coefficient, normal upstream reservoir elevation, drain efficiency and horizontal peak ground acceleration are incorporated into stability and stress analysis using Monte-Carlo simulations. In this thesis, utilization of CADAM software is demonstrated on a case study. Cindere dam is evaluated in terms of structural safety

The economic and safety hazards associated with the ability of gas hydrates to form in pipelines have prompted our interest in the inhibition of hydrate growth. Antifreeze proteins (AFPs) adsorb to ice surfaces and certain AFPs can also inhibit the growth of hydrates formed from water molecules organized in cage-like formations around a central small gas molecule. A Monte Carlo computational method for simulating the growth of ice crystals has been developed and it has proved useful in the understanding of the inhibition mechanism of these proteins. We have modified this crystal growth software in order to simulate the growth of large structure II gas hydrates, consisting of millions of water and gas molecules. This represents a first step towards investigating the effectiveness of novel compounds to inhibit hydrate growth in silico. Here, we describe these software modifications, and our efforts to incorporate type I AFP molecules into the hydrate growth simulations. Because both the docking interaction and inhibition mechanism for AFP towards hydrates remains unknown, we have set up a number of inhibitor screens to investigate possible AFP-hydrate docking models. Our goal is to reproduce the changes to gas hydrate morphology that have been observed in the presence of AFP, which will guide our choices for the binding alignment between AFPs and hydrates. This alignment will be instrumental for determining the AFPI-inhibition mechanism and should prove invaluable for the development of novel, hyperactive hydrate inhibitors.

No description available.

Diese Arbeit befaßt sich mit der Koppelung von Vertex-Modellen an die planaren $\phi^4$-Zufallsgraphen des Zugangs zur Quantengravitation über dynamische Polygonifizierungen. Das betrachtete System hat eine doppelte Bedeutung, einerseits als die Koppelung einer konformen Feldtheorie mit zentraler Ladung $C=1$ an zweidimensionale Euklidische Quantengravitation, andererseits als Anwendung von geometrischer, "annealed" Unordnung auf ein prototypisches Modell der statistischen Mechanik. Da das Modell mit Hilfe einer großangelegten Reihe von Monte Carlo Simulationen untersucht wird, müssen entsprechende Techniken für die Simulation von dynamischen Quadrangulierungen bzw. die dualen $\phi^4$-Graphen entwickelt werden. Hierzu werden verschiedene Algorithmen und die dazugehörigen Züge vorgeschlagen und hinsichtlich ihrer Ergodizität und Effizienz untersucht. Zum Vergleich mit exakten Ergebnissen werden die Verteilung der Koordinationszahlen bzw. bestimmte Analoga davon konstruiert. Für Simulationen des $F$-Modells auf $\phi^4$-Zufallsgraphen wird ein Ordnungsparameter für den antiferroelektrischen Phasenübergang mit Hilfe einer Plakettenspindarstellung formuliert. Ausführliche "finite-size scaling"-Analysen des Kosterlitz-Thouless-Phasenübergangs des $F$-Modells auf dem Quadratgitter und auf Zufallsgraphen werden vorgestellt und die Positionen der jeweiligen kritischen Punkte sowie die dazugehörigen kritischen Exponenten werden bestimmt. Die Rückreaktion des Vertex-Modells auf die Zufallsgraphen wird in Form der Koordinationszahlverteilung, der Verteilung der "Baby-Universen" und dem daraus resultierenden String-Suszeptibilitäts-Exponenten sowie durch die geometrische Zweipunktfunktion analysiert, die eine Schätzung der intrinsischen Hausdorff-Dimension des gekoppelten Systems liefert. / In this thesis, the coupling of ice-type vertex models to the planar $\phi^4$ random graphs of the dynamical polygonifications approach to quantum gravity is considered. The investigated system has a double significance as a conformal field theory with central charge $C=1$ coupled to two-dimensional Euclidean quantum gravity and as the application of a special type of annealed connectivity disorder to a prototypic model of statistical mechanics. Since the model is analyzed by means of large-scale Monte Carlo simulations, suitable simulation techniques for the case of dynamical quadrangulations and the dual $\phi^4$ random graphs have to be developed. Different algorithms and the associated update moves are proposed and investigated with respect to their ergodicity and performance. For comparison to exact results, the co-ordination number distribution of the dynamical polygonifications model, or certain analogues of it, are constructed. For simulations of the 6-vertex $F$ model on $\phi^4$ random graphs, an order parameter for its anti-ferroelectric phase transitions is constructed in terms of a "plaquette spin" representation. Extensive finite-size scaling analyses of the Kosterlitz-Thouless point of the square-lattice and random graph $F$ models are presented and the locations of the critical points as well as the corresponding critical exponents are determined. The back-reaction of the coupled vertex model on the random graphs is investigated by an analysis of the co-ordination number distribution, the distribution of "baby universes" and the string susceptibility exponent as well as the geometric two-point function, yielding an estimate for the internal Hausdorff dimension of the coupled system.

This dissertation contains five essays in the field of time series econometrics. The main issue discussed is the lack of coherence between small sample and asymptotic inference. Frequently, in modern econometrics distributional results are strictly only valid for a hypothetical infinite sample. Studies show that the attained actual level of a test may be considerable different from the nominal significance level, and as a concequence, too many true null hypotheses will falsely be rejected. This leads, in the extension, to applied users that too often reject evidence in the data for theoretical predictions. In large, the thesis discusses how computer intensive methods may be used to adjust the test distribution, such that the actual significance level will coincide with the desired nominal level. The first two essays focus on how to improve testing for persistence in data, through a bootstrap procedure within a univariate framework. The remaining three essays are studies of multivariate time series models. The third essay considers the identification problem of the basic stationary vector autoregressive model, which is also the basic-line econometric specification for maximum likelihood cointegration analysis. In the fourth essay the multivariate framework is expanded to allow for components of different integrating order and in this setting the paper discusses how fractional cointegration affects the inference in maximum likelihood cointegration analysis. The fifth essay consider once again the bootstrap testing approach, now in a multivariate application, to correct inference on long-run relations in maximum likelihood cointegration analysis. / Diss. Stockholm : Handelshögsk.

Ce travail porte sur l'étude de nanoparticules scintillatrices qui sont capables, par définition, de convertir un rayonnement ionisant en lumière visible ou proche UV. Si le processus de scintillation est actuellement bien connu dans le cas des matériaux macroscopiques, les perturbations susceptibles d'apparaître pour des nanomatériaux le sont moins. En effet, des modifications peuvent être induites par le confinement spatial et les spécificités de structure propres aux nanomatériaux. L'étude de ces perturbations constitue l'objet de cette thèse. Le manuscrit se divise en trois parties. La première vise à quantifier la fraction d'énergie qui se dépose dans une assemblée de nanoparticules après interaction avec un photon haute énergie (X ) ou en réalisant des simulations Monte Carlo basées sur le code de calcul Geant4. La deuxième partie présente un travail expérimental exploratoire qui consiste à comparer des mesures de spectroscopie résolue en temps pour des nanoparticules et un monocristal afin d'extraire des informations sur les étapes de thermalisation et de recombinaison radiative spécifiques aux nanoparticules. La dernière partie de ce manuscrit présente l'étude d'une application novatrice des nanoscintillateurs comme agents thérapeutiques. Ils sont alors utilisés pour activer sous excitation X l'effet photodynamique, base d'une thérapie anti-cancéreuse actuellement limitée au traitement de lésions superficielles / This work deals with scintillating nanoparticles, material able to convert ionizing radiations into visible or Ultra-Violet light. The scintillation process is currently well-known for bulk materials. However, for nanomaterials, several steps of the scintillation process are likely to be slightly modified mainly because of the spatial confinement of charges and the structure specificities in nanomaterials. The study of such perturbations is the aim of this thesis. The manuscript is divided into three parts. The first one aims to quantify the amount of deposited energy within a set of nanoparticles after the interaction with a high energy photon (X or –rays). We thus developed Monte Carlo simulations with the Geant4 toolkit to quantify this energy. The second part presents an exploratory experimental study that consists in comparing time resolved spectroscopy measurements for nanoparticles and a single crystal. The aim is to extract a few tendencies on the thermalization and on the radiative recombination processes specific to nanoscintillators. The last part of this thesis presents an application of nanoscintillators as therapeutic agents. In that case, they are used to activate the photodynamic effect under X-ray irradiation. This last effect is the basis of the photodynamic therapy, an anticancer treatment currently limited to superficial tumors

Made available in DSpace on 2014-06-11T19:22:54Z (GMT). No. of bitstreams: 0 Previous issue date: 2012-08-01Bitstream added on 2014-06-13T19:49:16Z : No. of bitstreams: 1 valle_rml_me_sjrp.pdf: 866733 bytes, checksum: 903cda2dc88f2ecf24f8cec8bd5ce702 (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / Neste trabalho utilizamos simulações de Monte Carlo para estudar as propriedades elétricas e conformacionais de polianfóteros fracos, investigando o efeito da estrutura primária, do pH da solução da valência dos contraíons. O polímero foi representado por um conjunto de esferas rígidas conectadas por um potencial harmônico (modelo bead-spring ) e os contraíons da solução, de valência 1, 2 e 3, foram tratados de maneira explícita segundo o modelo primitivo restrito. Todo o sistema foi confinado em uma célula esférica com o polímero fixado em seu centro. Dentre as análises de propriedades elétricas do polianfótero, foi observado que a fração de grupos básicos protonados se aproxima do caso ideal com o aumento da valência dos contraíons, para todas as sequências primárias estudadas. Diferentemente do que ocorre para homopolímeros carregados, nos quais os efeitos de correlação entre contraíons multivalentes provocam alta compactação da cadeia, o raio de giração de polienfóteros com contra ons trivalentes se mostrou muito próximo de cadeias (self-avoiding walk ). Em relação ao efeito da sequência primária, cadeias com baixa carga líquida apresentaram maior compactação nos casos de distribuição de monômero com menor número de blocos, assim como já previsto na literatura utilizando eletrólito implícito através da teoria de Debye-Hückel. A medida que aumentamos o valor de pH, o polinafótero ca carregado e conformações globulares não são mais observadas. Nestas condições, verificamos a formação de estruturas conhecidas como tadpoles apenas utilizando contraíons monovalente. Em nossa análise de Scaling, os valores conhecidos na literatura para o índice v da relação Rg ~ N vm foram obtidos para os casos Alternado (caso SAW) e Dibloco (caso globular) em regimes de pH nos quais a macromolécula está neutra apenas considerando diluição infinita / In this work we use the Monte Carlo simulations to study conformational and electrical properties of weak Polyampholytes and investigate the e ect of the primary structure, pH and the valency of the counterion on these conformations. The polymer was represented by a set of rigid spheres connected by a harmonic potential (bead-spring model) and the counterions of the solution of valency 1, 2 and 3 were treated explicitly according to the restricted primitive model. The system was enclosed in a spherical cell with the polymer set at its center. Among the analysis of electrical properties of the polyampholyte, it was observed that the fraction of protonated basic groups approaches the ideal case with the increase in valency of the counterion for all the primary sequence studied. Di erently from what occurs for homopolymers, in which the e ects of correlation between multivalent counterions cause high compression of the chain, the radius of gyration of polyampholytes considering trivalent counterions is very close to those obtained for Gaussian chains with excluded volume interaction (Self-Avoiding Walk ). Regarding the e ect of primary sequence, chains with low net charge showed higher compression in cases of fewer blocks monomers distribution, as already provided in previous work using implicit counterions by the Debye-H uckel theory. As the pH increased, the polyampholyte has a net charge and globular conformations are no longer observed. Accordingly, we observed the formation of structures known as tadpoles using monovalent counterions. In our analysis of Scaling, the known values for the index (in Rg N m) were obtained for Alternating case (SAW) and Diblock case (globular) in pH regimes in which the macromolecule has no net charge and only considering in nite dilution

Simulações computacionais são ferramentas essenciais para a compreensão num nível microscópico de diversos fenômenos que ocorrem na natureza. Em particular, simulações ab initio, isto é, de primeiros princípios, podem predizer novas propriedades e auxiliar na interpretação de resultados experimentais, sem a necessidade de potenciais empíricos os quais são ajustados para uma específica configuração do sistema. No entanto, mesmo para simulações ab initio são necessárias aproximações tanto para o cálculo de estrutura eletrônica quanto para a descrição dos movimentos nucleares. Nesta tese, novas aproximações para o funcional de energia de troca e correlação da Teoria do Funcional da Densidade (DFT) são propostas e testadas no cálculo de estrutura eletrônica de átomos, moléculas e sólidos. Para a descrição dos movimentos nucleares a técnica de Monte Carlo é utilizada, porém as energias totais são obtidas com a DFT. Propomos também uma nova metodologia que permite descrever movimentos intramoleculares de sistemas cujas frequências de vibração não podem ser tratadas classicamente. Como aplicações estudamos aglomerados de água e água líquida, mostrando a relevância dessa nova metodologia na descrição de propriedades estruturais, vibracionais e de momento de dipolo desses sistemas. / Computer simulations are essential tools for a microscopic understanding of many processes that occur in nature. In particular, ab initio simulations, i.e., first principles simulations, can predict new properties and support experimental results, without the need to use empirical potentials which are fitted for a specific configuration of the system. However, even in ab initio simulations it is necessary to do approximations for the electronic structure calculations and for the description of the nuclear movements. In this thesis, new approximations for the exchange-correlation energy functional of Density Functional Theory (DFT) are proposed and tested for atoms, molecules and solids. The description of the nuclear movements was done using the Monte Carlo technique, however the total energy calculations were obtained by DFT. We also propose a new methodology which allows the description of intramolecular movements whose vibrational frequencies can not be treated classically. As an illustration, we have studied water clusters and liquid water, showing the relevance of this new methodology on the description of structural, vibrational and of the dipole moment of these systems.

Studying the reactions where electrons and positrons collide and annihilate so that hadrons can be formed from their energy is an excellent tool when we try to improve our understanding of the standard model. Hadrons are composite quark systems held together by the strong force. By doing precise measurements of the, so called, cross section of the hadron production that was generated during the annihilation one can obtain information about the electromagnetic form factors, GE and GM, which describe the inner electromagnetic structure of hadrons. This will give us a better understanding of the strong force and the standard model.During my bachelor degree project I have been using data from the BESIII detector located at the Beijing Electron-Positron Collider (BEPC-II) in China. Uppsala university has several scientists working with the BESIII experiment. My task was to do a quality assurance of previous results for the reaction e+e-→ Lambda Lambda-Bar at a center of mass energy of 2.396 GeV. During a major part of the project I have been working with Monte Carlo data. Generating the reactions was done with two generators, ConExc and PHSP. The generators was used for different means. I have analyzed the simulated data to find a method of filtering out the background noise in order to extract a clean signal. Dr Cui Li at the hadron physics group at Uppsala university have worked with several selection criteria to extract these signals. The total efficiency of Cui Li's analysis was 14%. For my analysis I also obtained total efficiency of 14%. This gave me confidence that my analysis have been implemented in a correct fashion and that my analysis now can be transferred over to real data. It is also reassuring for Cui Li and the rest of the group that her analysis has been verified by and independently implemented selection algorithm. / Att studera vad som händer vid reaktioner där elektroner och positroner kolliderar och annihilerar så att hadroner kan bildas ur energin kan vara till stor hjälp när vi vill förstå standardmodellen och dess krafter, i synnerhet den starka kraften, som kan studeras i sådana reaktioner. Genom att utföra precisa mätningar av tvärsnitt för hadronproduktion får man fram de elektromagnetiska formfaktorerna GE och GM som beskriver hadronernas inre struktur. Hadroner är sammansatta system av kvarkar och den starka kraften binder dessa kvarkar.\\Under mitt examensarbete har jag använt mig av data från detektorn BESIII som finns vid BEPC-II (Beijing Electron-Positron Collider) i Kina. Uppsala universitet har flera forskare som jobbar med BESIII experimentet. Målet var att kvalitetssäkra den tidigare analys som gjorts för reaktionen e+e- → Lambda Lambda-Bar vid 2.396 GeV. Jag började med att göra Monte Carlo-simuleringar. Reaktionerna har genererats med två olika generatorer, ConExc och PHSP. Dessa generatorer har använts till olika ändamål. De genererade partiklarnas färd genom detektorn har sedan simulerats. Då bildas data av samma typ som dem man får från experiment. Jag har analyserat dessa simulerade data för att hitta en metod som kan filtrera bort bakgrundsstörningar samtidigt som intressanta data sparas. Kriterier utarbetade av Dr. Cui Li har använts för att skapa denna metod. Min algortim gav en total effektivitet på 14%, vilket stämmer bra med den tidigare algoritmen som Cui Li skapade, även där var effektiviteten 14%. Detta ger förtroende för min algortim och den stärker även Cui Lis resultat.