Hypertyreos kännetecknas av en förhöjd funktion i tyreoidea vilket bidrar till en ökad frisättning av tyreoideahormonerna thyroxin och trijodtyronin som påverkar ämnesomsättningen i kroppen. Graves’ sjukdom, toxisk nodös struma och autonomt adenom är olika varianter av hypertyreos som behandlas med radiojodbehandling respektive tyreostatikabehandling eller med kirurgi. Vid radiojodbehandling är det viktigt att massan av tyreoidea bestäms korrekt för att undvika över- respektive underbehandling. För närvarande är planar scintigrafi (PS) den mätmetod som används på isotopterapiavdelningen vid Skånes universitetssjukhus i Lund. Vid PS erhålls tvådimensionella bilder som används för uppskattning av massan. De tvådimensionella bilderna ger ingen djupinformation vilket kan leda till att tjockleken av tyreoidea feluppskattas. Tjockleken behövs för att erhålla en korrekt tyreoideamassa, och för att minimera denna feluppskattning kan en SPECT/CT-mätning (Single-Photon Emission Computed Tomography/Computed Tomography) utföras där tredimensionella bilder erhålls. Syftet med denna studie är att utvärdera hur uppskattningen av tyreoideamassan skiljer sig mellan de två mätmetoderna samt hur radiojodbehandlingen kan påverkas av detta. Studien omfattade fantommätningar samt bildtagning på 19 deltagare med hypertyreos. Resultaten visade att massuppskattningen av tyreoidea skiljer sig mellan PS- och SPECT/CT-mätningar. SPECT/CT-mätningarna förväntades ge en bättre massuppskattning vilket ger att skillnaderna mellan mätmetoderna påvisade över respektive underbehandlingar av tyreoidea jämfört med standarddoserna somanvänds på kliniken. / Hyperthyroidism is characterized by an overactive thyroid which contributes to anexcessive production of the thyroid hormones triiodothyronine and thyroxine which are responsible for regulation of the metabolism. Graves’ disease, multinodular goiter and toxic adenoma are different disorders that are treated with antithyroid medications, radioiodine treatment or surgery. For radioiodine treatment the thyroid mass is an important parameter that needs to be determined correctly to avoid an incorrect treatment. The thyroid mass is currently estimated by planar scintigraphy (PS) at the department of radionuclide therapy at Skånes University Hospital in Lund. PS provides two-dimensional imaging of the thyroid, which is used to determine the mass of the thyroid. Two-dimensional images do not give any information about the depth information which can cause errors in estimation of the thyroid thickness. The thickness of the thyroid is essential to obtain a correct thyroid mass, to minimize the errors a three-dimensional imaging can be made with a SPECT/CT (Single-Photon Emission Computed Tomography-/Computed Tomography). The aim of this study is to evaluate how the estimation of the thyroid mass differs between the two measurement methods and also how that can affect the radioiodine treatment. The study included phantom measurements and 19 participants with hyperthyroidism. The results of this study showed that the estimation of the thyroid mass differ between the PS- and SPECT/CT-measurements. The SPECT/CT-measurements is assumed to give more accurate mass estimations and given this, the differences of estimated mass showed both over- and undertreated thyroid compared with the standard doses that are used in the clinic.

As the fifth generation of telecommunications is deployed, and the number of devices transmitting in the microwave bands grows, effective filtering technologies are becoming ever more important. When a filter is designed, some performance trade-offs have to be made, and one of them is the trade-off between filter size and electrical performance. This thesis addresses this tradeoff by proposing two fourth order all-pole Chebyshev filters in the Ku band realised in suspended integrated stripline technology, which combine a small physical footprint with high unloaded Q-values. These characteristics make it possible to create more compact systems, or increase the filtering capability in systems where the existing filter size is the limiting factor. The first filter was designed with the goal of maximum compactness, with the resonators made up of metallic strips on both sides of the microwave substrate, with intra-resonator capacitive coupling between the strip, and inter-resonator capacitive coupling mainly between adjacent resonators. The second filter was made slightly larger but with improved electrical performance, with the main difference being a via shorting the resonator strips together, largely confining the electric field to the suspended integrated stripline’s air cavity. The comparison between these filters allows a potential systems engineer to make an informed decision on how compact a filter could be while still providing good enough performance. Both filters had a return loss less than 20 dB in the entire passband, the first filter had an insertion loss ranging from -2.15 dB to -1.6 dB, and the second filter had an insertion loss ranging from -2 dB to -1.1 dB. / I takt med att den femte generationen av telekommunikationsteknologi utvecklas och lanseras så finner sig kommunikationssystem i en allt mer brusig signalmiljö. Fler och fler system kommer att behöva dela på det tillgängliga elektromagnetiska spektrat, och därmed behövs allt mer effektiv teknologi för att filtrera signalerna, både på mottagar- och sändarsidan. Trådlös kommunikation sker med hjälp av elektromagnetisk strålning inom radiospektrat, och dessa signaler kräver speciella mikrovågskomponenter för förstärkning och filtrering. Mikrovågsfilter konstrueras ofta som stora och materialkrävande kavitetsfilter i metall, eftersom denna typ av filter har lägst förluster av de vanligt förekommande filtertyperna. Den stora materialåtgången är en uppenbar nackdel ur en hållbarhetssynpunkt, och storleken på filtret kan i vissa kompakta tillämpningar utgöra en begränsning av ett systems filtreringsförmåga. Detta examensarbete presenterar därmed två nya filter för Ku-bandet i integrerad hängande-substrat-stripline-teknologi, vars konstruktion kombinerar ett kompakt format med relativt låga energiförluster. Dessa filter utgör ett alternativ för framtida system som både kan tillåta miniatyrisering av system där filtrena är den begränsande faktorn storleksmässigt, såväl som att möjliggöra ökad filteringskapabilitet för redan kompakta system. Det första filtret, vars mål var maximal kompakthet hade förluster mellan -2.15 dB och -1.6 dB i passbandet, medan det andra filtret hade något större dimensioner och hade förluster mellan -2 dB och -1.1 dB. Då filtrena konstruerades i form av diskreta komponenter med koaxialdon, så är de angivna förlusterna till viss del orsakade av donen och dess omgivande struktur i filtrena. Förlusterna kan alltså vidare minimeras om filtrena i stället konstrueras som en del av ett integrerat system, direkt anslutna till en eller flera angränsande komponenter.

<p>This thesis is devoted to introducing new problem formulations and exact solution methods for a class of continuous covering location models. The manuscript includes three self-contained studies which are organized as in the following. </p> <p> In the first study, we introduce the planar expropriation problem with non-rigid rectangular facilities which has many applications in regional planning and undesirable facility location domains. This model is proposed for determining the locations and formations of two-dimensional rectangular facilities. Based on the geometric properties of such facilities, we developed a new formulation which does not require employing distance measures. The resulting model is a mixed integer nonlinear program. For solving this new model, we derived a continuous branch-and-bound framework utilizing linear approximations for the tradeoff curve associated with the facility formation alternatives. Further, we developed new problem generation and bounding strategies suitable for this particular branch-and-bound procedure. We designed a computational study where we compared this algorithm with two well-known mixed integer nonlinear programming solvers. Computational experience showed that the branch-and-bound procedure we developed performs better than BARON and SBB both in terms of processing time and size of the branching tree.</p> <p> The second study is referred to as the planar maximal covering problem with single convex polygonal shapes and it has ample applications in transmitter location, inspection of geometric shapes and directional antenna location. In this study, we investigated maximal point containment by any convex polygonal shape in the Euclidean plane. Using a fundamental separation property of convex sets, we derived a mixed integer linear formulation for this problem. We were able to identify two types of special cuts based on the geometric properties of the shapes under study, which were later employed for developing a branch-and-cut procedure for solving this particular location model. We also evaluated the resultant bound quality after employing the afore-mentioned cuts. </p> <p> In the third study, we discuss the dynamic planar expropriation problem with single convex polygonal shapes. We showed how the basic problem formulations discussed in the first two studies extend to their diametric opposites, and further to models in higher dimensions. Subsequently, we allowed a dynamic setting where the shape under study is expected to function over a finite planning horizon and the system parameters such as the fixed point locations and expropriation costs are subject to change. The shape was permitted to relocate at the beginning of each time period according to particular relocation costs. We showed that this dynamic problem structure can be decomposed into a set of static problems under a particular vector of relocations. We discussed the solution of this model by two enumeration procedures. Subsequently, we derived an incomplete dynamic programming procedure which is suitable for this distinct problem structure. In this method, there is no need to evaluate all the branches of the branching tree and one proceeds with keeping the minimum stage cost. The evaluation of a branch is postponed until relocation takes place in the lower-level problems. With this postponing structure, the procedure turned out to be superior to the two enumeration procedures in terms of tree size. </p> / Thesis / Doctor of Philosophy (PhD)

As one of the most common minerals in crustal rocks, quartz has been widely used as an indicator for shock metamorphism. Shocked quartz is found in the Chicxulub impact crater, an impact crater that has been linked to the Cretaceous-Tertiary extinction ~66 million years ago. The microstructural deformation features found in the shocked quartz do not form randomly, and their orientation provides a better understanding of the impact cratering process. At present, there are no studies of EBSD data analysis of shocked quartz from Chicxulub. We investigated six thin sections from two samples from the M0077A borehole in the lower peak ring of the Chicxulub impact crater, using the Scanning Electron Microscopy (SEM)-EBSD technique. Both samples consist of shocked granite, with a significant amount of quartz.  Therefore, this study investigates the crystallographic preferred orientation (CPO) of shocked quartz and predicts the seismic velocities and anisotropy, based on the EBSD data. We carried out the analysis of EBSD data by using the MATLAB-based MTEX toolbox that can perform CPO analysis from pole figure plots and the prediction of seismic properties of minerals based on the Voigt-Reuss-Hill effective medium method. Although acquiring the EBSD data from these samples is challenging, leading to the lack of data measured, we found out that the prediction of P wave seismic velocity is in good agreement with other recent studies conducted in the same area. The range of predicted P wave velocities is 5.5-6.5 km/s with anisotropy of 8-15%. The actual observed laboratory measurements and in-situ seismic measurements are considerably smaller than this velocity range because our calculations do not incorporate pores or take microcracks into account.  A likely explanation for the large variability of anisotropy in shocked quartz is the relatively few mapped grains with EBSD, which would influence the CPO and lead to high predicted seismic anisotropy. Considering a greaternumber of grains in the CPO analysis, the CPO is reduced, and seismic anisotropy becomes smaller.

Thesis (MSc)--Stellenbosch University, 2013. / ENGLISH ABSTRACT: Range images are images that store at each pixel the distance between the sensor and a particular point in the observed scene, instead of the colour information. They provide a convenient storage format for 3-D point cloud information captured from a single point of view. Range image segmentation is the process of grouping the pixels of a range image into regions of points that belong to the same surface. Segmentations are useful for many applications that require higherlevel information, and with range images they also represent a significant step towards complete scene reconstruction. This study considers the segmentation of range images into planar surfaces. It discusses the theory and also implements and evaluates some current approaches found in the literature. The study then develops a new approach based on the theory of graph cut optimization which has been successfully applied to various other image processing tasks but, according to a search of the literature, has otherwise not been used to attempt segmenting range images. This new approach is notable for its strong guarantees in optimizing a specific energy function which has a rigorous theoretical underpinning for handling noise in images. It proves to be very robust to noise and also different values of the few parameters that need to be trained. Results are evaluated in a quantitative manner using a standard evaluation framework and datasets that allow us to compare against various other approaches found in the literature. We find that our approach delivers results that are competitive when compared to the current state-of-the-art, and can easily be applied to images captured with different techniques that present varying noise and processing challenges. / AFRIKAANSE OPSOMMING: Dieptebeelde is beelde wat vir elke piksel die afstand tussen die sensor en ’n spesifieke punt in die waargenome toneel, in plaas van die kleur, stoor. Dit verskaf ’n gerieflike stoorformaat vir 3-D puntwolke wat vanaf ’n enkele sigpunt opgeneem is. Die segmentasie van dieptebeelde is die proses waarby die piksels van ’n dieptebeeld in gebiede opgedeel word, sodat punte saam gegroepeer word as hulle op dieselfde oppervlak lê. Segmentasie is nuttig vir verskeie toepassings wat hoërvlak inligting benodig en, in die geval van dieptebeelde, verteenwoordig dit ’n beduidende stap in die rigting van volledige toneel-rekonstruksie. Hierdie studie ondersoek segmentasie waar dieptebeelde opgedeel word in plat vlakke. Dit bespreek die teorie, en implementeer en evalueer ook sekere van die huidige tegnieke wat in die literatuur gevind kan word. Die studie ontwikkel dan ’n nuwe tegniek wat gebaseer is op die teorie van grafieksnit-optimering wat al suksesvol toegepas is op verskeie ander beeldverwerkingsprobleme maar, sover ’n studie op die literatuur wys, nog nie gebruik is om dieptebeelde te segmenteer nie. Hierdie nuwe benadering is merkbaar vir sy sterk waarborge vir die optimering van ’n spesifieke energie-funksie wat ’n sterk teoretiese fondasie het vir die hantering van geraas in beelde. Die tegniek bewys om fors te wees tot geraas sowel as die keuse van waardes vir die min parameters wat afgerig moet word. Resultate word geëvalueer op ’n kwantitatiewe wyse deur die gebruik van ’n standaard evalueringsraamwerk en datastelle wat ons toelaat om hierdie tegniek te vergelyk met ander tegnieke in die literatuur. Ons vind dat ons tegniek resultate lewer wat mededingend is ten opsigte van die huidige stand-van-die-kuns en dat ons dit maklik kan toepas op beelde wat deur verskeie tegnieke opgeneem is, alhoewel hulle verskillende geraastipes en verwerkingsuitdagings bied.

The project contains adventurous research, with an aim to understand and design a planar Gunn diode with a novel integrated circuit configuration to extract the 2nd harmonic. This will potentially enhance the Gunn diode as a high frequency source towards frequencies in excess of 600 GHz. The RF performance from the above integrated circuit was achieved by design and simulation of radial and diamond stub resonators, which were used to short the fundamental oscillation frequency while allowing the second harmonic frequency to pass through to the load. The diamond stub resonator is a new configuration offering a number of advantages which include a higher loaded quality factor and occupies 55% less chip area than a comparable radial stub resonator. The designed novel circuits with integrated planar Gunn diode were fabricated using microwave monolithic integrated circuits (MMIC) technology at the James Watt Nanofabrication centre in Glasgow University. Full DC and microwave characterisation of the diodes and integrated circuits with diodes was carried out using a semiconductor analyser, network analyser (10 MHz to 110GHz) and spectrum analyser (10 MHz to 125GHz). The microwave measurements were carried out at the high frequency RF laboratories in Glasgow University. Both GaAs and InP based Gunn diodes were characterised and RF characterisation work showed that higher fundamental frequencies could be obtained from Gunn diodes fabricated on InGaAs on a lattice matched InP substrate. Planar Gunn diodes with an anode to cathode spacing of 4 microns giving a fundamental frequency of oscillation of 60 GHz were fabricated as an integrated circuit with coplanar waveguide (CPW) circuit elements to extract the second harmonic. A second harmonic frequency of 120 GHz with an RF output power of -14.11 dBm was extracted with very good fundamental frequency suppression. To the authors knowledge this was the first time second harmonic frequencies have been extracted from a planar Gunn diode technology. Aluminium gallium arsenide (AlGaAs) planar Gunn diodes were also designed with an integrated series inductor to match the diode at the fundamental frequency to obtain higher RF output powers. Devices with a 1 micron anode to cathode separation gave the highest fundamental oscillation frequency of 121 GHz the highest reported for a GaAs based Gunn diode and with an RF output power of -9 dBm. These circuits will have potential applications in secure communications, terahertz imaging etc.

This thesis investigates the computation of invariance kernels for planar nonlinear systems with one input, with application to wind turbine stability. Given a known bound on the absolute value of the input variations (possibly around a fixed non-zero value), it is of interest to determine if the system's state can be guaranteed to stay within a desired region K of the state space irrespective of the input variations. The collection of all initial conditions for which trajectories will never exit K irrespective of input variations is called the invariance kernel. This thesis develops theory to characterize the boundary of the invariance kernel and develops an algorithm to compute the exact boundary of the invariance kernel. The algorithm is applied to two simplified wind turbine systems that tap kinetic energy of the turbine to support the frequency of the grid. One system provides power smoothing, and the other provides inertial response. For these models, limits on speed and torque specify a desired region of operation K in the state space, while the wind is represented as a bounded input. The theory developed in the thesis makes it possible to define a measure called the wind disturbance margin. This measure quantifies the largest range of wind variations under which the specified type of grid support may be provided. The wind disturbance margin quantifies how the exploitation of kinetic energy reduces a turbine's tolerance to wind disturbances. The improvement in power smoothing and inertial response made available by the increased speed range of a full converter-interfaced turbine is quantified as an example.

Approved for public release; distribution is unlimited / The Linearly Tapered Slot Antenna (LTSA) had been investigated and developed experimentally; its applications have primarily been based on empirical designs. An accurate theoretical model based on Moment Methods (MM) is developed here to study the radiation characteristics of the LTSA. Using the MM solutions to the reaction integral equation, this thesis presents an analysis to model and explain the LTSA behavior. The effects of variable design parameters on radiation patterns are studied. Discussion is augmented by relating predicted radiation patterns to calculated current distributions on the antenna surface. Conclusions are made regarding optimum designs for the LTSA. Relevant observations are made concerning the extensive computational tasks and the computer resources required for the MM model. / http://archive.org/details/modelingbehavior00kell / Major, United States Army

Im Vortrag geht es um die Erstellung von Berechnungsmodellen zur Simulation ebener Koppelgetriebe in SimulationX. Der Fokus liegt hierbei auf der vollparametrischen Modellsteuerung während der Getriebesynthese in SimulationX. Neben Möglichkeiten zur Steuerung und Variation der Simulationsmodelle während der Berechnung wird die Entwicklung von Berechnungsmodulen zur Individualisierung des Berechnungsprozesses vorgestellt. Möglichkeiten zur Steuerung der Simulation und Co-Simulation bei anderen Programmen ist ebenfalls Thema weiterer Ansätze zur domänenübergreifenden Gesamtsimulation von Koppelgetrieben.

The development of organs such as the lung and kidney occurs by branching morphogenesis. Changes in the cytoskeletal architecture, cell-cell adhesion and cell polarity are necessary for the formation of new branches. Interactions and reciprocal signalling between epithelial and mesenchymal cells mediate these organised cell movements that give rise to a complex system of tubes suitable for the transport of gas or fluids. Mutations that disrupt formation of either the correct number, or shape of epithelial branches, affect lung function. This, in turn, can lead to congenital abnormalities such as cystadenomatoid malformations, pulmonary hypertension or lung hypoplasia. Defects in lung architecture are also associated with adult lung disease, particularly in cases of idiopathic lung fibrosis. Identifying the signaling pathways that drive epithelial tube formation will likely shed light on both congenital and adult lung disease. This study shows that mutations in the planar cell polarity (PCP) genes: Celsr1; Vangl2 and Scribble, lead to disrupted lung development and defects in lung architecture. Examination of Vangl2 mutant kidneys reveals similar impairment of branching morphogenesis. Detailed histological and immunocytochemical analysis reveals that lungs from Celsr1Crsh/Crsh, Vangl2Lp/Lp and ScribbleCrc/Crc mice are small and misshapen with fewer branches, and by late gestation exhibit thickened interstitial mesenchyme and defective saccular formation. Moreover, epithelial integrity is disrupted, cytoskeletal remodeling perturbed and mutant endoderm does not branch normally in response to the chemoattractant FGF10. In ex-vivo culture, inhibition of Rho kinase, an important downstream effector of the PCP signaling pathway, can mimic the branching defects observed in these three mouse mutants. Furthermore, all three proteins are present in restricted spatial domains within lung epithelium. ScribbleCrc/Crc lungs, the most severely affected line, exhibit additional defects in components of the tight and adherens junctions; this in turn affects lumen diameter. These findings show that components of the PCP pathway: Celsr1; Vangl2 and Scribble are required for normal foetal lung development, thereby revealing a novel signalling pathway critical for this process. Examination of postnatal mice was not possible as homozygous mutations result in embryonic lethality. However, an assessment of Vangl2Lp/+ mice reveals that loss of a single copy of Vangl2 is enough to cause defects in embryonic lung development that persist into adult life, affecting lung function. Similarly, Vangl2Lp/+ mice show a small but significant reduction in kidney glomeruli.