Global ETD Search

261	Metody potlačení strukturního šumu typu spekle / Speckle noise suppression methods in ultrasound images Teplý, Lukáš Unknown Date (has links) Ultrasound investigation is one of meaningful imaging at present. Advantages of ultrasound are, that it hasn´t side effects as a rtg radiation and it is noninvasive. Ultrasound diagnostic is exploited in all branch of medicine (urology, cardiology, orthopeadist, gynecology etc.) to display organs, tissues and cavities of the human body. We use display in 2D, 3D and most modern display in 4D. We can encounter with many kinds of artifact. Artifacts are described more closely at 3rd chapter. Speckle noise deteriorates informative yiled of ultrasound picture. We try to remove speckle noise by simpler methods or more complex methods of filtration. These methods are described at 5th chapter. Programme for speckle filtering from pictures is part of this master´s thesis.
262	Filtrace signálů EKG s využitím vlnkové transformace / Wavelet filtering of ECG Signals Ryšánek, Jan January 2012 (has links) This work deals with the possibilities of filtering the ECG signal, representing the first part, which is the basis for successful delineation and follow diagnosis of the ECG signal. Filtration in this case is mean to suppress interference from electrical grid, noise of electrical grid. The content of the work is description of filters realized trough wavelet transform and linear filtering as a means to successful filtration of interference. There are method of stationary wavelet transform - dyadic wavelet transform, wavelet packet transform and wavelet wiener filtering method. Linear filtering includes two narrow-band FIR filters. The objective of this work is to propose different methods of wavelet and linear filters in Matlab, filtering of ECG signals and compare the success of filtration methods. ECG signals used in this work are from the CSE database.
263	Erwin A. Schmidl: Habsburgs jüdische Soldaten 1788–1918 Weber, Elisabeth 13 August 2019 (has links) No description available. info:eu-repo/classification/ddc/290 ddc:290 info:eu-repo/classification/ddc/940 ddc:940
264	Evaluation of a Novel Reconstruction Framework for Gamma Knife Cone-Beam CT - The Impact of Scatter Correction and Noise Filtering on Image Quality and Co-registration Accuracy / Utvärdering av nytt rekonstruktionsramverk för Cone-Beam CT på Gammakniven - Effekten av spridningskorrigering och brusfiltrering på bildkvalitet och noggrannhet av co-registrering Hägnestrand, Ida January 2023 (has links) The Gamma Knife is a non-invasive stereotactic radiosurgery system used for treatments of deep targets in the brain. Accurate patient positioning is needed for precise radiation delivery to the target. The two latest versions of the Gamma Knife allow fractionated treatment by co-registering Cone-beam computed tomography (CBCT) images of the patient's position in the Gamma Knife with a diagnostic magnetic resonance (MR) image used for treatment planning. However, CBCT images often suffer from artifacts that degrade image quality, which may result in less accurate co-registration. This thesis project investigates the potential of a new reconstruction framework developed by Elekta, which incorporates scattering correction and noise filters, for the reconstruction of Gamma Knife CBCT images. The performance of the new reconstruction framework, along with its noise filter and scatter correction, is quantified using image quality metrics of phantoms, including contrast, uniformity, spatial resolution, and CT-number accuracy. Additionally, brain CBCT images of five patients are co-registered with their diagnostic MR images, and the mean target registration error is measured. The results indicate that the new reconstruction framework, without using scatter correction and noise filtering, performs equally well as the current framework in reconstructing Gamma Knife CBCT images, as it achieved similar image quality and co-registration accuracy. However, when the scatter correction was used, there were improvements in image uniformity and CT-number accuracy without compromising spatial resolution. Additionally, the introduction of a noise filter resulted in an improved contrast-to-noise ratio and low contrast visibility with minimal compromise of spatial resolution. Despite these image quality enhancements, there were no consistent improvements in co-registration accuracy, indicating that the co-registration is not sensitive to scatter or noise artefacts. / Gammakniven är en medicinteknisk apparat som används för icke-invasiv stereotaktisk strålkirurgi vid behandling av djupa mål i hjärnan. För att uppnå precision i strålbehandlingen krävs noggrann patientpositionering. De två senaste versionerna av Gammakniven tillåter fraktionerad behandling genom att co-registrera cone-beam computed tomography (CBCT)-bilder av patientens position i Gammakniven med en diagnostisk magnetresonans (MR)-bild som används för behandlingsplanering. Tyvärr lider CBCT-bilder ofta av artefakter som kan försämra bildkvaliteten och därmed minska precisionen i co-registreringen. Detta examensarbete undersöker ett nytt rekonstruktionsramverk som utvecklats av Elekta. Det nya rekonstruktionsramverket och dess tillhörande brusfilter och spridningskorrigering utvärderas för rekonstruktion av Gammaknivens CBCT bilder med hjälp av bildkvalitetsmått för fantomer, såsom kontrast, uniformitet, spatial upplösning och noggrannhet i CT-nummer. Dessutom co-registreras CBCT-bilder från fem patienter med deras diagnostiska MR-bilder, och det genomsnittliga registreringsfelet mäts. Resultaten visar att det nya rekonstruktionsramverket, utan användning av spridningskorrigering och brusfiltrering, presterar lika bra som det nuvarande ramverket för rekonstruktion av CBCT-bilder från Gammakniven. Båda ramverken ger liknande bildkvalitet och noggrannhet i co-registreringen av bilderna. Vid användning av spridningskorrigering observerades förbättringar i uniformiteten och noggrannheten i CT-nummer utan att den spatiala upplösningen försämrades. Införandet av brusfilter resulterade i ett förbättrat kontrast-brus-förhållande och synlighet av svaga kontrastskillnader med endast lite avkall på den spatiala upplösningen. Trots dessa förbättringar i bildkvaliteten observerades ingen konsekvent förbättring av noggrannheten i co-registreringen av bilderna, vilket tyder på att co-registreringen inte påverkas av spridnings- eller brusartefakter i stor utsträckning. Gamma Knife Cone-beam computed tomography Image quality Image reconstruction Co-registration Contrast Uniformity Spatial resolution Scatter correction Wiener filter Noise filter Patient positioning Stereotactic radiosurgery Gammakniv Strålkniv Cone-Beam Computed Tomography Bildkvalitet Bildrekonstruktion Co-registrering Kontrast Uniformitet Spatial upplösning Spridningskorrigering Wienerfilter Brusfilter Stereotaktisk strålkirurgi Physical Sciences Fysik
265	Demokratie und pacta sunt servanda Fulda, Christian B. 10 October 2002 (has links) Das Demokratieprinzip ist im Völkerrecht verankert. Seine normativen Grundlagen sind zum einen das Vertragsrecht, insbesondere der Internationale Pakt über bürgerliche und politische Rechte, sowie die regionalen Verankerungen in Europa und in Amerika durch die Satzungen der jeweiligen internationaler Organisationen und ihrer Menschenrechtsinstrumente. Substantielle vertragliche Verpflichtungen ergeben sich auch aus den bilateralen Verträgen der EG. Zum anderen fußt es auf der Staatenpraxis, insbesondere im Rahmen der UNO. So ist die internationale Gemeinschaft auf die Errichtung demokratischer Strukturen verpflichtet, wenn sie staatliche Funktionen in failed states übernimmt oder den Wiederaufbau eines Staatswesens begleitet. Die Demokratieresolutionen der UNO lassen erkennen, daß alle Staaten verpflichtet sind, das Ziel der Demokratie anzustreben und erreichte demokratische Errungenschaften zu gewährleisten. Das Demokratieprinzip beinhaltet normativ die Legitimation staatlichen Handelns durch freie Wahlen und die Absicherung durch Menschenrechte, Gewaltenteilung und Rechtsstaatlichkeit. Staatliche Entscheidungen bedürfen daher einer legitimierenden Rückbindung an den frei geäußerten Willen des konstituierenden Staatsvolkes, wobei die Freiheit dieser Willensäußerung in dynamischer Perspektive die Freiheit der Willensänderung garantiert. Sowohl der Vertragsschluß als Akt staatlichen Handelns als auch der Inhalt des Vertrages bedürfen der Legitimation, und zwar über die Zeit hinweg. Das geltende Völkervertragsrecht berücksichtigt das Demokratieprinzip jedoch nur unzureichend. Die Verletzung innerstaatlichen Rechts beim Vertragsschluß kann nur eingeschränkt geltend gemacht werden. Es existiert auch kein Verfahren, mit dem die fortdauernde Legitimation eines Vertrages überprüft werden könnte. Angesichts der Zunahme von Verträgen, die innere Angelegenheiten der Gesellschaften regeln, bedarf das Spannungsverhältnis einer Lösung. Das Problem wird illustriert durch Frankreichs Ausstieg aus der NATO, Senegals Kündigung der Seerechtskonventionen, den Streit um den deutschen Atomausstieg, das Verfahren um den Donaustaudamm Gabcíkovo Nagymaros, die Frage der Vereinbarkeit von Drogenkonsumräumen mit den UN-Anti-Drogenkonventionen, das Schiedsverfahren zwischen Aminoil und Kuwait sowie der Kündigung des ABM-Vertrages durch die USA. Ein erster Ansatz zur Lösung kann in einer Neuinterpretation der völkervertragsrechtlichen Regeln liegen. So bietet sich der Grundsatz der "demokratiefreundlichen Interpretation" an. Internes Recht, das der Kontrolle der Exekutive dient, muß beim Vertragsschluß Berücksichtigung finden. Und Verträgen, die "innere Angelegenheiten" betreffen, kann ein implizites Kündigungsrecht zugebilligt werden. Der wesentliche Ansatz ist aber kautelarjuristischer Natur. Revisions-, Experimentier- und Kündigungsklauseln können bei der Abfassung von Verträgen die Vertragsbeziehung so ausgestalten, daß zukünftige Meinungsänderungen berücksichtigt werden können. Schließlich ist de lege ferenda ein Recht auf Revision, kombiniert mit einem subsidiären Kündigungsrecht, wünschenswert. Mit einem solchen Mechanismus könnten neue normative Lösungen eingeführt werden und die Legitimation bestehender Normen auf den Prüfstand gestellt werden. / International law provides for a democratic principle. It is based both on treaty law and customary law. The International Covenant for Civil and Political Rights as well as the regional treaties in Europe and the Americas - the statutes of the respective regional organisations and their human rights instruments - form a substantial body of treaty obligations toward democracy, which is complemented by bilateral treaties of the EC safeguarding democracy. State practice, especially within the framework of the UN, indicates an obligation to establish democratic structures whenever the international community takes upon itself the task of nation building in failed states. The democracy resolutions of the UN point out that all member states are obliged to strive for democracy and uphold democratic achievements so far. The normative democratic principle includes the legitimation of public affairs through free and fair elections and the guarantee of human rights, separation of powers and the rule of law. Acts of states therefore must be legitimised through the freely expressed will of the people. Under a dynamic perspective, the free will includes the possibility for changes of policy. The conclusion of treaties as an act of state as well as the content of the treaty as a rule of law need to be legitimised through the times. The current law of treaties does not acknowledge the democratic principle, however. Violations of internal law at the conclusion of a treaty can only be claimed to a limited extent. Nor does international law provide for a formal procedure to validate the on-going support for the content of the treaty. Facing an ever-growing expansion of the number of treaties dealing with the internal affairs of societies, solutions must be found. The problem is being illustrated by France's withdrawal from NATO, Senegal's withdrawal from the Geneva Conventions on the Law of the Sea, the dispute related to the question of the use of nuclear energy in Germany, the judgement of the ICJ in the Gabcíkovo-Nagymaros case, the question of the compatibility of drug consumption rooms with UN anti-drug conventions, the dispute settlement award in the Aminoil case and last not least the denunciation of the ABM treaty by the US. Realigning the interpretation of the law of treaties to the democratic principle is one way to deal with the problem. Interpretation of treaties should take into account the democratic principle. Internal law controlling the executive has to be complied with where conclusion of treaties is concerned. And treaties dealing with "internal affairs" can be considered to contain an implicit right of withdrawal or denunciation. The proper solution lies in respecting the democratic principle when drafting treaties, though. Clauses of revision, clauses allowing for experiments and clauses of denunciation or withdrawal help shaping a contractual relationship that can take into account changes of the political will. Last not least, a right of revision is recommended de lege ferenda, combined with a subsidiary right of denunciation or withdrawal. Such a mechanism allows for introducing new normative solutions and for validating the on-going legitimation of existing treaty rules. (See also the English summary at the end of the thesis.) Völkerrecht Demokratie Europarat Europäische Menschenrechtskonvention OAS Amerikanische Menschrechtskonvention Assoziationsabkommen der EG UNO Kambodscha Haiti Dayton Ost-Timor Afghanistan Demokratieresolutionen Vertragsrecht Wiener Vertragsrechtskonvention Vertragsschluß Kündigung Revision NATO Atomausstieg Drogenkonsumräume ABM-Vertrag Gabcíkovo-Nagymaros Public International Law Democracy Council of Europe European Convention on Human Rights OAS American Convention on Human Rights Inter-American Democratic Charter Treaties of association of the EC UNO Cambodia Haiti Dayton East-Timor Afghanistan Resolutions on democracy Law of treaties Vienna Convention on the Law of Treaties conclusion of treaties denunciation or withdrawal revision NATO nuclear energy drug consumption rooms ABM treaty Gabcíkovo-Nagymaros 340 Recht 19 Recht PR 2207 ddc:340
266	Nonlinear Dynamic Modeling, Simulation And Characterization Of The Mesoscale Neuron-electrode Interface Thakore, Vaibhav 01 January 2012 (has links) Extracellular neuroelectronic interfacing has important applications in the fields of neural prosthetics, biological computation and whole-cell biosensing for drug screening and toxin detection. While the field of neuroelectronic interfacing holds great promise, the recording of high-fidelity signals from extracellular devices has long suffered from the problem of low signal-to-noise ratios and changes in signal shapes due to the presence of highly dispersive dielectric medium in the neuron-microelectrode cleft. This has made it difficult to correlate the extracellularly recorded signals with the intracellular signals recorded using conventional patch-clamp electrophysiology. For bringing about an improvement in the signalto-noise ratio of the signals recorded on the extracellular microelectrodes and to explore strategies for engineering the neuron-electrode interface there exists a need to model, simulate and characterize the cell-sensor interface to better understand the mechanism of signal transduction across the interface. Efforts to date for modeling the neuron-electrode interface have primarily focused on the use of point or area contact linear equivalent circuit models for a description of the interface with an assumption of passive linearity for the dynamics of the interfacial medium in the cell-electrode cleft. In this dissertation, results are presented from a nonlinear dynamic characterization of the neuroelectronic junction based on Volterra-Wiener modeling which showed that the process of signal transduction at the interface may have nonlinear contributions from the interfacial medium. An optimization based study of linear equivalent circuit models for representing signals recorded at the neuron-electrode interface subsequently iv proved conclusively that the process of signal transduction across the interface is indeed nonlinear. Following this a theoretical framework for the extraction of the complex nonlinear material parameters of the interfacial medium like the dielectric permittivity, conductivity and diffusivity tensors based on dynamic nonlinear Volterra-Wiener modeling was developed. Within this framework, the use of Gaussian bandlimited white noise for nonlinear impedance spectroscopy was shown to offer considerable advantages over the use of sinusoidal inputs for nonlinear harmonic analysis currently employed in impedance characterization of nonlinear electrochemical systems. Signal transduction at the neuron-microelectrode interface is mediated by the interfacial medium confined to a thin cleft with thickness on the scale of 20-110 nm giving rise to Knudsen numbers (ratio of mean free path to characteristic system length) in the range of 0.015 and 0.003 for ionic electrodiffusion. At these Knudsen numbers, the continuum assumptions made in the use of Poisson-Nernst-Planck system of equations for modeling ionic electrodiffusion are not valid. Therefore, a lattice Boltzmann method (LBM) based multiphysics solver suitable for modeling ionic electrodiffusion at the mesoscale neuron-microelectrode interface was developed. Additionally, a molecular speed dependent relaxation time was proposed for use in the lattice Boltzmann equation. Such a relaxation time holds promise for enhancing the numerical stability of lattice Boltzmann algorithms as it helped recover a physically correct description of microscopic phenomena related to particle collisions governed by their local density on the lattice. Next, using this multiphysics solver simulations were carried out for the charge relaxation dynamics of an electrolytic nanocapacitor with the intention of ultimately employing it for a simulation of the capacitive coupling between the neuron and the v planar microelectrode on a microelectrode array (MEA). Simulations of the charge relaxation dynamics for a step potential applied at t = 0 to the capacitor electrodes were carried out for varying conditions of electric double layer (EDL) overlap, solvent viscosity, electrode spacing and ratio of cation to anion diffusivity. For a large EDL overlap, an anomalous plasma-like collective behavior of oscillating ions at a frequency much lower than the plasma frequency of the electrolyte was observed and as such it appears to be purely an effect of nanoscale confinement. Results from these simulations are then discussed in the context of the dynamics of the interfacial medium in the neuron-microelectrode cleft. In conclusion, a synergistic approach to engineering the neuron-microelectrode interface is outlined through a use of the nonlinear dynamic modeling, simulation and characterization tools developed as part of this dissertation research. Whole cell biosensors cell sensor interface neuron electrode interface neuroelectronic interfacing microelectrode arrays meas field effect transistor (fet) arrays limitations of equivalent circuit models volterra wiener modeling nonlinear dynamic modeling nonlinear impedance spectroscopy lattice boltzmann method lattice poisson boltzmann method multiphysics solver entrance flow problem surface chemical reaction electroosmotic flow ionic electrodiffusion primitive model of electrolyte charge relaxation dynamics electrolytic nanocapacitor effect of nanoscale confinement overlapping electric double layers electric double layer relaxation viscous drag force on ions in a solvent Physics
267	Highway Development Decision-Making Under Uncertainty: Analysis, Critique and Advancement El-Khatib, Mayar January 2010 (has links) While decision-making under uncertainty is a major universal problem, its implications in the field of transportation systems are especially enormous; where the benefits of right decisions are tremendous, the consequences of wrong ones are potentially disastrous. In the realm of highway systems, decisions related to the highway configuration (number of lanes, right of way, etc.) need to incorporate both the traffic demand and land price uncertainties. In the literature, these uncertainties have generally been modeled using the Geometric Brownian Motion (GBM) process, which has been used extensively in modeling many other real life phenomena. But few scholars, including those who used the GBM in highway configuration decisions, have offered any rigorous justification for the use of this model. This thesis attempts to offer a detailed analysis of various aspects of transportation systems in relation to decision-making. It reveals some general insights as well as a new concept that extends the notion of opportunity cost to situations where wrong decisions could be made. Claiming deficiency of the GBM model, it also introduces a new formulation that utilizes a large and flexible parametric family of jump models (i.e., Lévy processes). To validate this claim, data related to traffic demand and land prices were collected and analyzed to reveal that their distributions, heavy-tailed and asymmetric, do not match well with the GBM model. As a remedy, this research used the Merton, Kou, and negative inverse Gaussian Lévy processes as possible alternatives. Though the results show indifference in relation to final decisions among the models, mathematically, they improve the precision of uncertainty models and the decision-making process. This furthers the quest for optimality in highway projects and beyond. highway development decision making under uncertainty real options jump processes infinitely divisible distributions Lévy processes measure theory characteristic function characteristic exponent Lévy jump measure probability measure cádlág stochastic process Wiener process Poisson process compound Poisson process finite activity models jump diffusion models Merton model Gaussian jump process Kou model double exponential jump process leptokurtic volatility smile infinite activity models pure jumps process generalized hyperbolic model modified Bessel function negative inverse Gaussian model geometric Brownian motion model log-normal distribution model normality assumption heavy-tailed distribution asymmetric distribution quantile-quantile plot Rydberg algorithm parameter calibration moments cummulants sum of squares Monte Carlo simulation least-squares regression backward dynamic programming discrete-time Markov chain land price traffic demand highway service quality index data collection traffic volume Annual Average Daily Traffic Ontario Ministry of Transportation Land Registry Office Freedom of Information Act seasonality value of transportation types of transportation systems importance of highway systems cost of wrong decisions monetary cost private sector cost human cost land expropriation environmental cost irreversibility cost factor time cost factor political cost factor opportunity cost opportunity cost of wrong decisions economic cost of wrong decisions economic cost of mis-estimation economic profit of wrong decisions cost of inaction price of making right decisions scope of decisions rehabilitation decision land acquisition decision expansion decision uncertainty modeling land acquisition cost expropriation cost construction cost material cost Montréal-Mirabel International Airport Pickering Airport 407 Express Toll Route Highway 407 Statistics
268	Highway Development Decision-Making Under Uncertainty: Analysis, Critique and Advancement El-Khatib, Mayar January 2010 (has links) While decision-making under uncertainty is a major universal problem, its implications in the field of transportation systems are especially enormous; where the benefits of right decisions are tremendous, the consequences of wrong ones are potentially disastrous. In the realm of highway systems, decisions related to the highway configuration (number of lanes, right of way, etc.) need to incorporate both the traffic demand and land price uncertainties. In the literature, these uncertainties have generally been modeled using the Geometric Brownian Motion (GBM) process, which has been used extensively in modeling many other real life phenomena. But few scholars, including those who used the GBM in highway configuration decisions, have offered any rigorous justification for the use of this model. This thesis attempts to offer a detailed analysis of various aspects of transportation systems in relation to decision-making. It reveals some general insights as well as a new concept that extends the notion of opportunity cost to situations where wrong decisions could be made. Claiming deficiency of the GBM model, it also introduces a new formulation that utilizes a large and flexible parametric family of jump models (i.e., Lévy processes). To validate this claim, data related to traffic demand and land prices were collected and analyzed to reveal that their distributions, heavy-tailed and asymmetric, do not match well with the GBM model. As a remedy, this research used the Merton, Kou, and negative inverse Gaussian Lévy processes as possible alternatives. Though the results show indifference in relation to final decisions among the models, mathematically, they improve the precision of uncertainty models and the decision-making process. This furthers the quest for optimality in highway projects and beyond. highway development decision making under uncertainty real options jump processes infinitely divisible distributions Lévy processes measure theory characteristic function characteristic exponent Lévy jump measure probability measure cádlág stochastic process Wiener process Poisson process compound Poisson process finite activity models jump diffusion models Merton model Gaussian jump process Kou model double exponential jump process leptokurtic volatility smile infinite activity models pure jumps process generalized hyperbolic model modified Bessel function negative inverse Gaussian model geometric Brownian motion model log-normal distribution model normality assumption heavy-tailed distribution asymmetric distribution quantile-quantile plot Rydberg algorithm parameter calibration moments cummulants sum of squares Monte Carlo simulation least-squares regression backward dynamic programming discrete-time Markov chain land price traffic demand highway service quality index data collection traffic volume Annual Average Daily Traffic Ontario Ministry of Transportation Land Registry Office Freedom of Information Act seasonality value of transportation types of transportation systems importance of highway systems cost of wrong decisions monetary cost private sector cost human cost land expropriation environmental cost irreversibility cost factor time cost factor political cost factor opportunity cost opportunity cost of wrong decisions economic cost of wrong decisions economic cost of mis-estimation economic profit of wrong decisions cost of inaction price of making right decisions scope of decisions rehabilitation decision land acquisition decision expansion decision uncertainty modeling land acquisition cost expropriation cost construction cost material cost Montréal-Mirabel International Airport Pickering Airport 407 Express Toll Route Highway 407 Statistics

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