The growing number of wireless devices and wireless systems present many challenges on the design and operation of these networks. We focus on massively dense ad hoc networks and cellular systems. We use the continuum modeling approach, useful for the initial phase of deployment and to analyze broad-scale regional studies of the network. We study the routing problem in massively dense ad hoc networks, and similar to the work of Nash, and Wardrop, we define two principles of network optimization: user- and system-optimization. We show that the optimality conditions of an appropriately constructed optimization problem coincides with the user-optimization principle. For different cost functions, we solve the routing problem for directional and omnidirectional antennas. We also find a characterization of the minimum cost paths by extensive use of Green's theorem in directional antennas. In many cases, the solution is characterized by a partial differential equation. We propose its numerical analysis by finite elements method which gives bounds in the variation of the solution with respect to the data. When we allow mobility of the origin and destination nodes, we find the optimal quantity of active relay nodes. In Network MIMO systems and MIMO broadcast channels, we show that, even when the channel offers an infinite number of degrees of freedom, the capacity is limited by the ratio between the size of the antenna array at the base station and the mobile terminals position and the wavelength of the signal. We also find the optimal mobile association for the user- and system-optimization problem under different policies and distributions of the users.

This dissertation describes the design and implementation of a system that has been designed to extract 3D information from pairs of 2D images. System input consists of two images taken by an ordinary digital camera. System output is a full 3D model extracted from 2D images. There are no assumptions about the positions of the cameras during the time when the images are being taken, but the scene must not undergo any modifications. The process of extracting 3D information from 2D images consists of three basic steps. First, point matching is performed. The main contribution of this step is the introduction of an approach to matching image segments in the context of an approximation space. The second step copes with the problem of estimating external camera parameters. The proposed solution to this problem uses 3D geometry rather than the fundamental matrix widely used in 2D to 3D conversion. In the proposed approach (DirectGS), the distances between reprojected rays for all image points are minimised. The contribution of the approach considered in this step is a definition of an optimal search space for solving the 2D to 3D conversion problem and introduction of an efficient algorithm that minimises reprojection error. In the third step, the problem of dense matching is considered. The contribution of this step is the introduction of a proposed approach to dense matching of 3D object structures that utilises the presence of points on lines in 3D space. The theory and experiments developed for this dissertation demonstrate the usefulness of the proposed system in the process of digitizing 3D information. The main advantage of the proposed approach is its low cost, simplicity in use for an untrained user and the high precision of reconstructed objects. / October 2007

In this thesis we have studied baryon resonances generated from the dynamical interaction of two hadrons. We are interested on this study as an alternative approach to explain the increasing number of observed charmed states which apparently do not fit into the traditional three quark picture of a baryon. In particular, we study baryon molecules with JP = ½ - which can be formed from the attractive interaction of a pseudoscalar meson (0-) and a ground state baryon (1/2+) in s-wave (L = 0). Therefore our aim is to contribute to the understanding of the observed charm baryon spectra by checking if the dynamical origin can explain those states which are candidates to be a baryon resonance with JP =1/2-. The important feature of our model is the description of the meson-baryon interaction in terms of the t-channel vector meson exchange which is fully solved without any approximation. The first part of the thesis is devoted to study these sort of baryon molecules in free space. In order to learn about the nature of a baryon it is important to study its different types of decays. For this reason, we will calculate the strong decays of dynamically generated resonances into meson-baryon components, as well as the electromagnetic transition of such hadron molecules into the lowest-lying ground states. In the second part of the thesis we have included medium and temperature effects on the formalism to study the properties of the charmed baryon resonant states in hot and dense matter. This will allow us as well to study the properties of charmed mesons (D, D, Ds and Ds) in the nuclear medium which will be simultaneously dressed in the self-consistent calculation for the first time. The behaviour of these mesons will influence the charmonium production whose suppression is connected with the possible formation of quark-gluon plasma at a dense matter and high temperature scenario. / En esta tesis se han estudiado las resonancias bariónicas generadas a partir de la interacción dinámica de dos hadrones. Estamos interesados en este estudio como un enfoque alternativo para explicar el creciente número de estados observados con quark encanto y que aparentemente no encajan en la imagen tradicional de tres quarks de un barión. En particular, se estudian las moléculas de bariones con JP = ½ - que pueden formarse a partir de la interacción atractiva de un mesón pseudoescalar (0-) y un barión del estado fundamental ( 1/2+) en onda s (L = 0). Por tanto, nuestro objetivo es comprobar si el origen dinámico puede explicar aquellos estados que son candidatos a ser una resonancia bariónica con JP =1/2-. La característica importante del modelo es la descripción de la interacción mesón-barión en términos del canal t de intercambio de mesones vectoriales, que está resuelto sin ningún tipo de aproximación.La primera parte de la tesis está dedicada a estudiar este tipo de moléculas en el espacio libre. Con el fin de aprender sobre la naturaleza de un barión es importante estudiar sus diferentes tipos de desintegración. Por esta razón, calculamos las desintegraciones fuertes de las resonancias en canales mesón-barión, así como la transición electromagnética a bariones de estado fundamental.En la segunda parte de la tesis se ha incluido en el formalismo los efectos del medio y de la temperatura para estudiar las propiedades de los estados de bariones encantados en materia caliente y densa. Esto nos permitirá también estudiar las propiedades de los mesones encantados (D, D, Ds y Ds) en el medio nuclear, que serán vestidos autoconsistentemente en el cálculo por primera vez. El comportamiento de estos mesones influirá en la producción de “charmonium”, cuya supresión está relacionada con la posible formación de plasma de quark-gluón en materia densa y caliente.

Methods for measuring deformation and motion of the human heart in-vivo are crucial in the assessment of cardiac function. Applications ranging from basic physiological research, through early detection of disease to follow-up studies, all rely on the quality of the measurements of heart dynamics. This thesis presents new improved magnetic resonance imaging methods for acquisition, image reconstruction and visualization of cardiac motion and deformation.As the heart moves and changes shape during the acquisition, synchronization to the heart dynamics is necessary. Here, a method to resolve not only the cardiac cycle but also the respiratory cycle is presented. Combined with volumetric imaging, this produces a five-dimensional data set with two cyclic temporal dimensions. This type of data reveals unique physiological information, such as interventricular coupling in the heart in different phases of the respiratory cycle.The acquisition can also be sensitized to motion, measuring not only the magnitude of the magnetization but also a signal proportional to local velocity or displacement. This allows for quantification of the motion which is especially suitable for functional study of the cardiac deformation. In this work, an evaluation of the influence of several factors on the signal-to-noise ratio is presented for in-vivo displacement encoded imaging. Additionally, an extension of the method to acquire multiple displacement encoded slices in a single breath hold is also presented.Magnetic resonance imaging is usually associated with long scan times, and many methods exist to shorten the acquisition time while maintaining acceptable image quality. One class of such methods involves acquiring only a sparse subset of k-space. A special reconstruction is then necessary in order to obtain an artifact-free image. One family of these reconstruction techniques tailored for dynamic imaging is the k-t BLAST approach, which incorporates data-driven prior knowledge to suppress aliasing artifacts that otherwise occur with the sparse sampling. In this work, an extension of the original k-t BLAST method to two temporal dimensions is presented and applied to data acquired with full coverage of the cardio-respiratory cycles. Using this technique, termed k-t2 BLAST, simultaneous reduction of scan time and improved spatial resolution is demonstrated. Further, the loss of temporal fidelity when using the k-t BLAST approach is investigated, and an improved reconstruction is proposed for the application of cardiac function analysis.Visualization is a crucial part of the imaging chain. Scalar data, such as regular anatomical images, are straightforward to display. Myocardial strain and strain-rate, however, are tensor quantities which do not lend themselves to direct visualization. The problem of visualizing the tensor field is approached in this work by combining a local visualization that displays all degrees of freedom for a single tensor with an overview visualization using a scalar field representation of the complete tensor field. The scalar field is obtained by iterated adaptive filtering of a noise field, creating a continuous geometrical representation of the myocardial strain-rate tensor field.The results of the work presented in this thesis provide opportunities for improved imaging of myocardial function, in all areas of the imaging chain; acquisition, reconstruction and visualization.

Recent algorithms for video coding achieve a high-quality transmission at moderate bit rates. On the other hand, those coders are very sensitive to transmission errors. Many research projects focus on methods to conceal such errors in the decoded video sequence. Motion compensated prediction is commonly used in video coding to achieve a high compression ratio. This thesis proposes an algorithm which uses the motion compensated prediction of a given video coder to predict a sequence of several complete frames, based on the last correctly decoded images, during a transmission interruption. The proposed algorithm is evaluated on a video coder which uses a dense motion field for motion compensation. A drawback of predicting lost fields is the perceived discontinuity when the decoder switches back from the prediction to a normal mode of operation. Various approaches to reduce this discontinuity are investigated.

Groundwater at many existing and former industrial sites and disposal areas is contaminated by halogenated organic compounds that were released into the environment. The chlorinated solvent trichloroethylene (TCE) is one of the most ubiquitous of these compounds. In situ chemical oxidation (ISCO) has been successfully used for the removal of TCE. The objective of this study was to apply the ISCO technology to remediate TCE-contaminated groundwater. In this study, potassium permanganate (KMnO4) was used as the oxidant during the ISCO process. The study consisted bench-scale and pilot-scale experiments. In the laboratory experiments, the major controlling factors included oxidant concentrations, effects of soil oxidant demand (SOD) on oxidation efficiency, and addition of dibasic sodium phosphate on the inhibition of production of manganese dioxide (MnO2). Results show that higher molar ratios of KMnO4 to TCE corresponded with higher TCE oxidation rate under the same initial TCE concentration condition. Moreover, higher TCE concentration corresponded with higher TCE oxidation rate under the same molar ratios of KMnO4 to TCE condition. Results reveal that KMnO4 is a more stable and dispersive oxidant, which is able to disperse into the soil materials and react with organic contaminants effectively. Significant amount of MnO2 production can be effectively inhibited with the addition of Na2HPO4. Results show that the increase in the first-order decay rate was observed when the oxidant concentration was increased, and the half-life was approximately 24.3 to 251 min. However, the opposite situation was observed when the second-order decay rate was used to describe the reaction. Results from the column experiment show that the breakthrough volumes were approximately 50.4 to 5.06 pore volume (PV). Injection of KMnO4 would cause the decrease in TCE concentration through oxidation. Results also indicate that the addition of Na2HPO4 would not inhibit the TCE removal rate. In the second part of this study, a TCE-contaminated site was selected for the conduction of pilot-scale study. A total of eight remediation wells were installed for this pilot-scale study. The initial TCE concentrations of the eight wells were as follows: C1 = 0.59 mg/L, C1-E = 0.64 mg/L, C1-W = 0.61 mg/L, EW-1 = 0.65 mg/L, EW-1E = 0.62 mg/L, EW-1W = 0.57 mg/L, C2 = 0.62 mg/L, C3 = 0.35 mg/L. C1, EW-1, C2, and C3 were located along the groundwater flow direction from the upgradient (C1) to the downgradient location (C3), and the distance between each well was 3 m. C1-E and C1-W were located in lateral to C1 with a distance of 3 m to C1. EW-1E and EW-1W were in lateral to EW-1 with a distance of 3 m to EW-1. In the first test, 2,700 L of KMnO4 solution was injected into each of the three injection wells (C1, C1-E, and C1-W) with concentration of 5,000 mg/L. Three injections were performed with an interval of 6 hr between each injection. After injection, the TCE concentrations in those three wells dropped down to below detection limit (<0.0025 mg/L). However, no significant variations in TCE concentrations were observed in other wells. In the second test, 2,700 L of KMnO4 solution was injected into injection well (EW-1) with concentration of 5,000 mg/L. Six injections were performed with an interval of 6 hr between each injection. After injection, the TCE concentrations in the injection well dropped down to below detection limit (<0.0025 mg/L). TCE concentrations in (C1, C1-E, C1-W, EW-1E, EW-1W, C2, and C3) dropped to 0.35-0.49 mg/L. After injection, no significant temperature and pH variation was observed. However, increase in conductivity and oxidation-reduction potential (ORP) was observed. This indicates that the KMnO4 oxidation process is a potential method for TCE-contaminate site remediation. The groundwater conductivity increased from 500 £gS/cm to 1,000 £gS/cm, and ORP increased from 200 to 600 mv. Increase in KMnO4, MnO2, and total Mn was also observed in wells. Results from the slug tests show that the hydraulic conductivity remained in the range from 10-4 to 10-5 m/sec before and after the KMnO4 injection.

Interparticle interactions determine the microstructure, stability, rheology, and optical properties of concentrated colloidal suspensions involved in paint, paper, cosmetic, and pharmaceutical industries, etc. Frequency domain photon migration (FDPM) involves modeling the photon transport in a multiple scattering medium as a diffusion process in order to simultaneously determine isotropic scattering and absorption coefficients from measured amplitude attenuation and phase shift of the propagating photon density wave. Using FDPM, we investigated the impact of electrostatic interaction upon the optical properties and structure of dense charged suspensions. We demonstrated that electrostatic interactions among charged polystyrene latex may significantly affect the light scattering properties and structure of dense suspensions at low ionic strength (<0.06 mM NaCl equivalent) by actual FDPM measurement. We showed that the structure factor models addressing electrostatic interaction can be used to describe the microstructure of charged suspensions and quenched scattering due to electrostatics, and demonstrated that FDPM has the potential to be a novel structure and surface charge probe for dense suspensions. We also showed that the FDPM measured isotropic scattering coefficients may respond to the change in effective particle surface charge, and displayed the potential of using FDPM for probing particle surface charge in concentrated suspensions. We presented that the interference approximation implies a linear relationship between the absorption coefficient and volume fraction of suspension. We illustrated that FDPM measured absorption coefficient varies linearly with suspension volume fraction and affirmed the interference approximation from a perspective of light absorption. The validation of the interference approximation enables us to develop the methodology for estimating absorption efficiencies and imaginary refractive indices for both particles and suspending fluid simultaneously using FDPM. We further demonstrated a novel application of FDPM measured absorption coefficients in determining pigment absorption spectra, and displayed the potential of using FDPM as a novel analytical tool in pigment and paint industry.

The use of hazardous toxic substances is very common in the industrial sector. The substances are often stored in tanks in storage compartments or transported between industrial premises. In case of an accident involving these substances, severe harm can affect both population and the environment. This leaves a demand for an accurate prediction of the substance concentration distribution to mitigate the risks as much as possible and in advance create suitable safety measures. Toxic gases and vapors are often denser than air making it affected by negative buoyancy forces. This will make the gas descend and spread horizontally when reaching the ground. Swedish Defence Research Agency (FOI) carries today a model called LillPello for simulating the dispersion of gases, yet it does not account for the specific case of a dense gas. Therefore, this thesis aims to implement the necessary effects needed to accurately simulate the dispersion of a dense gas. These effects were implemented in Fortran 90 by solving five conservation equations for energy, momentum (vertical and horizontal) and mass. The model was compared against experimental data of a leak of ammonia (NH3). By analyzing the result of the simulations in this thesis, we can conclude that the overall result is satisfactory. We can notice a small concentration underestimation at all measurement points and the model produced a concentration power law coefficient which lands inside the expected range. Two out of the three statistical quantities Geometric Mean (MG), Geometric Variance (VG) and Factor of 2 (FA2) produced values within the ranges of acceptable values. The drawback of the model as it is implemented today is its efficiency, so the main priority for the future of this thesis is to improve this. The model should also be analyzed on more experiments to further validate its accuracy. / Användandet av giftiga ämnen är vanligt inom den industriella sektorn. Ämnena är oftast lagrade i behållare positionerade i lagringsutrymmen eller så transporteras ämnena mellan industrilokaler. I samband med en olycka innehållande dessa substanser kan stora skador drabba både befolkning och miljön. Detta leder till ett behov av att noggrant kunna förutspå koncentrationsfördelningen för att minska riskerna, samt i förväg kunna skapa lämpliga säkerhetsåtgärder. Giftiga gaser och ångor är oftast tyngre än luft vilket gör att gasen blir påverkad av negativ bärkraft. Detta gör att gasen sjunker och sprids horisontalt när den når marken. Totalförsvarets Forskningsinstitut (FOI) besitter idag en modell kallad LillPello som simulerar spridning av gaser, men den hanterar inte det specifika fallet av en tunggas. Därför siktar detta projekt på att, in i LillPello, implementera de nödvändiga effekterna som behövs för att korrekt kunna simulera spridningen av en tunggas. Dessa effekter är implementerad i Fortran 90 genom att lösa fem konserveringsekvationer för energi, momentum (vertikal och horisontell) samt massa. Modellen jämfördes mot data från ett fältexperiment där ammoniak (NH3) släpptes ut. Genom att analysera resultatet från simuleringar kan vi dra slutsatsen att det övergripande resultatet är tillfredsställande. Vi kan notera en underskattning för alla koncentrationsmätningar i simuleringarna och modellen producerade en potenslagsexponent vars värde hamnade innanför den accepterade gränsen. Två utav de tre beräknade statistiska kvantiteterna: Geometriskt medelvärde (MG), Geometrisk varians (VG) och Faktor av 2 (FA2) producerade värden inom de acceptabla gränserna. Största nackdelen med modellen är dess effektivitet och därför är största prioritet för det fortsatta arbetet inom detta projekt att effektivisera implementeringen. Modellen ska även bli vidare analyserad mot fler experiment för att validera dess noggrannhet.

Rheological properties of idealised models which exhibit all the non-Newtonian flow phenomenology commonly seen in dense suspensions are investigated by particulate-dynamics computer-simulations. The objectives of these investigations are: (i) to establish the origins of various aspects of dense suspension rheology such as shear-thinning, shear thickening and dilatancy; (ii) to elucidate the different regions of a typical dense suspension rheogram by examining underlying structures and shear induced anisotropies in kinetic energy, diffusivity and pressure; (iii) to investigate the scaling of the simplest idealised model suspension; i.e. the hard-sphere model in Newtonian media and its relationship to the isokinetic flow curves obtained through non-equilibrium molecular dynamics (NEMD) simulations; (iv) to preliminarily determine the effect of perturbations present in all real colloidal suspensions, namely particle size polydispersity and a slight 'softness' of the interparticle potential. Non-equilibrium isokinetic simulations have been performed upon ;systems of particles interacting through the classical hard-sphere potential and a perturbation thereof, in which the hard-core is surrounded by a 'slightly soft' repulsive skin. The decision to base the present work upon isokinetic studies was made in order to obtain a better under- standing of suspension rheology by making a direct connection with previous NEMD studies of thermal systemst(93). These studies have shown that the non-linear behaviour exhibited by these systems under shear is atttributable to a shear-induced perturbation of the equilibrium phase behaviour. The present study shows this behaviour to correspond to the high shear region of the generalised suspension flow curve.

Cystatin Related Epididymal Spermatogenic protein (CRES) is expressed in both the testis and epididymis and found associated with spermatozoa. It appears as non-glycosylated (14 and 12 kDa) and glycosylated isoforms (19 and 17 kDa). The role of CRES is enigmatic and dependent on localization of its isoforms, which is the objective of this study. The initial approach was to investigate testicular and epididymal origins of these isoforms by immunohistochemistry and immunogold cytochemistry. To further pinpoint CRES localization we then selectively extracted and fractionated epididymal spermatozoa in order to find by immunoblotting which sperm fractions contained CRES isoforms. Immunohistochemical analysis of mouse spermatogenesis showed that CRES was expressed in the tail cytoplasm of elongating spermatids from step 9-16, with a pattern reminiscent of outer dense fibre (ODF) proteins. Ultrastructural immunocytochemistry revealed that the immunogold label was concentrated over growing ODFs and mitochondrial sheath in the testes which persisted in spermatozoa through the epididymis. Sequential extractions of isolated sperm tails with Triton X-100-dithiothreitol (DTT) to remove the mitochondrial sheath, whose extract contained an unrelated 66 kDa immunoreactive band, followed by either sodium dodecyl sulfate (SDS)-DTT or urea-DTT to solubilise accessory fibres of the tail revealed a 14 kDa immunoreactive band associated with the ODF. In addition, Western blots revealed glycosylated and non-glycosylated CRES isoforms in nonyl phenoxylpolyethoxylethanol (NP40) extracts of the caput, but not cauda, sperm. Immunohistochemical analysis of the caput and cauda epithelium showed that CRES is secreted by the Golgi apparatus of the ii initial segment, fills the proximal caput lumen, and disappears by mid caput. Western blots of caput and cauda tissue and luminal fluid revealed 14 and 19 kDa immunoreactive bands in caput tissues and luminal fluid, but not in the cauda. This study concludes that there are two origins of CRES, one arising in the testis and the other in the epididymis. Testicular CRES is ionically and covalently associated with the ODF while epididymal CRES is detergent soluble and is most likely associated temporarily with the surface of caput epididymal sperm. / Thesis (Master, Anatomy & Cell Biology) -- Queen's University, 2010-09-03 14:22:01.913