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Mafické a intermediální intruze jako průvodci peraluminických granitů krušnohorského batolitu / Mafic and intermediate intrusions accompanying peraluminious granites of the Krušné hory Mts.batholitHolečková, Pavla January 2012 (has links)
Mafic and intermediate intrusions commonly accompany Variscan granitoid plutons in Europe. They are documented from different localities of Iberian Peninsula, from the French Massif Central, Schwarzwald, from different parts of the Bohemian Massif, in Romania, Greece, Corsica and Sardinia. They comprise wide petrographic varieties from quartz gabbros, diorites, granodiorites to monzonites. They usually constitute small bodies or veins, they often occur as mafic microgranular enclaves (MME) in granodiorites and in some granites. Dioritic intrusions are characterized by a relatively high amounts of lithophile elements (Rb, Sr, Ba, Cs, LREE), and they are simultaneously high in compatible elements (Ni, Cr, V a Co). Their isotopic ratios 87 Sr/86 Sr are in all compared locations similar and are close to the Bulk Earth (0.704 - 0.708). εNd values show larger scatter, some intrusions have more crustal composition (to -8), on the other hand, another intrusions have εNd positive, that points to a contribution of basic magma. The age of dioritic intrusions differs according to individual locality suggesting more than one magmatic episode. The oldest occur in the French Massif Central (361 - 365 Ma), whereas the youngest are documented in Iberia (312 - 310 Ma). The oldest mafic intrusions in the Bohemian...
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Stochastické diferenciální rovnice s gaussovským šumem a jejich aplikace / Stochastic Differential Equations with Gaussian Noise and Their ApplicationsCamfrlová, Monika January 2020 (has links)
In the thesis, multivariate fractional Brownian motions with possibly different Hurst indices in different coordinates are considered and a Girsanov-type theo- rem for these processes is shown. Two applications of this theorem to stochastic differential equations driven by multivariate fractional Brownian motions (SDEs) are given. Firstly, the existence of a weak solution to an SDE with a drift coeffi- cient that can be written as a sum of a regular and a singular part and a diffusion coefficient that is dependent on time and satisfies suitable conditions is shown. The results are applied for the proof of existence of a weak solution of an equation describing stochastic harmonic oscillator. Secondly, the Girsanov-type theorem is used to find the maximum likelihood scalar estimator that appears in the drift of an SDE with additive noise. 1
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Image-space Tensor Field Visualization Using a LIC-like MethodEichelbaum, Sebastian, Hlawitschka, Mario, Hamann, Bernd, Scheuermann, Gerik 14 December 2018 (has links)
Tensors are of great interest to many applications in engineering and in medical imaging, but a proper analysis and visualization remains challenging. Physics-based visualization of tensor fields has proven to show the main features of symmetric second-order tensor fields, while still displaying the most important information of the data, namely the main directions in medical diffusion tensor data using texture and additional attributes using color-coding, in a continuous representation. Nevertheless, its application and usability remains limited due to its computational expensive and sensitive nature.
We introduce a novel approach to compute a fabric-like texture pattern from tensor fields motivated by image-space line integral convolution (LIC). Although, our approach can be applied to arbitrary, non-selfintersecting surfaces, we are focusing on special surfaces following neural fibers in the brain.We employ a multipass rendering approach whose main focus lies on regaining three-dimensionality of the data under user interaction as well as being able to have a seamless transition between local and global structures including a proper visualization of degenerated points.
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Advances in MINLP for Optimal Distillation Column SequencingRadhakrishna Tumbalam Gooty (9759830) 14 December 2020 (has links)
<div>Designing configurations for multicomponent distillation, a ubiquitous process in chemical and petrochemical industries, is often challenging. This is because, as the number of components increases, the number of admissible distillation configurations grows rapidly and these configurations vary substantially in their energy needs. Consequently, if a method could identify a few energy-efficient choices from this large set of alternatives, it would be extremely attractive to process designers. Towards this, we develop the first mixed-integer nonlinear programming (MINLP) based solution approach that successfully identifies the most energy-efficient distillation configuration for a given separation. Current sequence design strategies are largely heuristic. The rigorous approach presented here can help reduce the significant energy consumption and consequent greenhouse gas emissions by separation processes. </div><div> </div><div>In addition to the combinatorial complexity, the challenge in solving this problem arises from the nonconvex fractional terms contained in the governing equations. We make several advances to enable solution of these problems.</div><div><br></div><div>(1). We propose a novel search space formulation by embedding convex hulls of various important substructures. We prove that the resulting formulation dominates all the prior formulations in the literature.</div><div><br></div><div>(2). We derive valid cuts to the problem by exploiting the monotonic nature of the governing equations. </div><div><br></div><div>(3). We adapt the classical Reformulation-Linearization Technique (RLT) for fractional terms. Our RLT variant exploits the underlying mathematical structure of the governing equation, and yields a provably tighter convex relaxation.</div><div><br></div><div>(4). We construct the simultaneous hull of multiple nonlinear terms that are constrained over a polytope obtained by intersecting a hypercube with mass balance constraints. This yields a tighter convex relaxation than the conventional approach where the nonlinear terms are convexified individually over a box.</div><div><br></div><div>(5). A key challenge in constructing a valid convex relaxation has been that the denominator of certain fractions in the governing equation can approach arbitrarily close to zero. Using our RLT variant, we construct the first valid relaxation. </div><div><br></div><div>(6). We leverage powerful mixed-integer programming (MIP) solvers by implementing a discretization-based solution procedure with an adaptive partitioning scheme.</div><div><br></div><div>With extensive computational experiments, we demonstrate that the proposed approach outperforms the state-of-the-art in the literature. The formulation can be tailored to other objectives by appending the relevant constraints. Here, we present an extension that identifies the distillation configuration that has the highest thermodynamic efficiency. Finally, we illustrate the practicality of the developed approaches with case studies on crude fractionation and natural gas liquid recovery. </div>
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Fractional exhaled nitric oxide in pulmonary hypertensionPaz, Miguel Ángel 24 July 2018 (has links)
BACKGROUND: Pulmonary Hypertension (PH) is a common form of high blood pressure in the lungs. It affects the pulmonary arteries, which normally allow blood to flow from the right heart to the lungs. Nitric Oxide (NO) is a potential mediator for establishing PH and decreasing its availability is implicated in the pathogenesis of PH.
HYPOTHESIS: We tested the hypothesis that Fractional Exhaled Nitric Oxide (FeNO) is a good indicator to assess disease severity that may add to understanding the disease.
METHODS: The aim of the study was to measure FeNO levels in consecutive PH patients and seek correlations with the 6 Minute walk distance (6MWD) within different World Health Organization (WHO) groups and New York Health Association Function Class (NYHA FC). Assignment to groups I or IV was done respecting the current guidelines. All values were taken at Tufts Medical Center PAH clinic visits. FeNO levels were measured utilizing the NIOX device.
RESULTS: FeNO levels were highest in WHO Group 1 and lowest in WHO Group 5 patients. There was a strong inverse correlation between FeNO and 6MWD for each NYHA FC. (Pearson correlation of -0.986, p = 0.014). Within WHO Groups, we found significantly inverse correlations between FeNO and 6MWD in PH Group 4 (p= 0.012) and PH Group 5 (p=0.001). NYHA FC correlated with 6MWD across all WHO Groups (P=0.001).
CONCLUSION: We report for the first time FeNO levels in all WHO Groups of PH. FeNO levels are low in early disease. FeNO levels correlate inversely with the severity of PH in WHO Group 4 and 5 patients. The increase in FeNO in more severe patients may reflect the degree of oxidative stress and inflammation in severe PH. Further studies to determine whether FeNO may be a biomarker in early disease, especially in PH Group 4 and 5 warrants further investigation.
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The Quantum Hall EffectGrälls, Conrad January 2020 (has links)
The quantum Hall effect occurs when a conductor carrying a current is placed in a perpendicular magnetic field. If certain conditions are met, such as strong magnetic field and low temperature, the resistivity becomes quantised, taking values of integer or fractional multiples of h/e2. By analysing the movement of electrons in a magnetic field classically and quantum mechanically information about the integer quantum Hall effect and the fractional quantum Hall effect can be gathered, using the two different gauge potentials of Landau gauge and Symmetric gauge. Resistance Metrology is one field of study that the quantum Hall effect has greatly impacted by providing a way to universally maintain the ohm, with significantly less uncertainty than previously. / Den kvantmekaniska hall-effekten uppstår när en strömbärande ledare placeras i ett vinkelrätt magnetfält. Om vissa villkor är uppfyllda, såsom starkt magnetfält och låg temperatur, blir resistiviteten kvantiserad. Given av heltal (integer) eller fraktions-(fractional) multiplar av h/e2. Genom att analysera elektroners rörelse i ett magnetfält klassiskt och kvantmekaniskt fås information om Hall-effekterna; integer quantum Hall effect och fractional quantum Hall effect, med hjälp av de två gauge potentialerna Landau gauge och Symmetrisk gauge. Resistansmetrologi är ett forskningsområde som kvant Hall-effekten har starkt påverkat genom att tillhandahålla ett sätt att universellt upprätthålla ohm-enheten med betydligt mindre osäkerhet än tidigare.
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Locating Unknown Wireless Devices Using Stimulated Emissions and the Fractional Fourier TransformGustafsson, Per January 2013 (has links)
Unknown wireless devices that use receiver architectures with a mixer may be detected and located using stimulated emissions. Transmitting a known stimulation signal and correlating leaked mixer products allows measurement of the TOF and thus range. The FRFT improves the detection of the stimulated emissions by compressing the energy of the stimulated emissions to a single axis value. The stimulation signal has many parameters that may be optimized for maximum detection distance or minimum range error or somewhere in between. The primary limiting factor for the parameters is the processing time, as the algorithm to compute the discrete FRFT is computationally intensive at the time of this report. The tests performed in this investigation achieved 45+meters detection distance with < 3 meters of range error, with potential for farther detection distance.
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Management of Two-Row Winter Malting Barley to meet Yield and Quality RequirementsMcGlinch, Gregory Joseph January 2021 (has links)
No description available.
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Fraktionale Modellierung und Parametrierung von technischen SpulenAbuaisha, Tareq, Kertzscher, Jana 19 November 2019 (has links)
Die genaue Abbildung des Verhaltens von technischen Spulen über einen weiten Frequenzbereich ist für eine präzise Modellierung von technischen Maschinen notwendig. Technische Spulen mit einem ferromagnetischen Kern zeigen andere Eigenschaften als ideale Spulen [1, 2]. Dies ist auf die Wirbelstromverluste, Hystereseverluste und ab einem bestimmten Frequenzbereich auftretenden Skineffektverlusten zurückzuführen. In diesem Beitrag werden zwei Verfahren der Modellierung von technischen Spulen, das klassische Modell und das fraktionale Modell, miteinander verglichen. Für beide Modelle werden die Parameter anhand der Methode der kleinsten Fehlerquadrate (MKQ) identifiziert. Die gewonnenen Ergebnisse werden an Messungen validiert.
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Decentralized Coordination of Multiple Autonomous VehiclesCao, Yongcan 01 May 2010 (has links)
This dissertation focuses on the study of decentralized coordination algorithms of multiple autonomous vehicles. Here, the term decentralized coordination is used to refer to the behavior that a group of vehicles reaches the desired group behavior via local interaction. Research is conducted towards designing and analyzing distributed coordination algorithms to achieve desired group behavior in the presence of none, one, and multiple group reference states. Decentralized coordination in the absence of any group reference state is a very active research topic in the systems and controls society. We first focus on studying decentralized coordination problems for both single-integrator kinematics and double-integrator dynamics in a sampled-data setting because real systems are more appropriate to be modeled in a sampled-data setting rather than a continuous setting. Two sampled-data consensus algorithms are proposed and the conditions to guarantee consensus are presented for both fixed and switching network topologies. Because a number of coordination algorithms can be employed to guarantee coordination, it is important to study the optimal coordination problems. We further study the optimal consensus problems in both continuous-time and discrete-time settings via an linear-quadratic regulator (LQR)-based approach. Noting that fractional-order dynamics can better represent the dynamics of certain systems, especially when the systems evolve under complicated environment, the existing integer-order coordination algorithms are extended to the fractional-order case. Decentralized coordination in the presence of one group reference state is also called coordinated tracking, including both consensus tracking and swarm tracking. Consensus tracking refers to the behavior that the followers track the group reference state. Swarm tracking refers to the behavior that the followers move cohesively with the external leader while avoiding inter-vehicle collisions. In this part, consensus tracking is studied in both discrete-time setting and continuous-time settings while swarm tracking is studied in a continuous-time setting. Decentralized coordination in the presence of multiple group reference states is also called containment control, where the followers will converge to the convex hull, i.e., the minimal geometric space, formed by the group references states via local interaction. In this part, the containment control problem is studied for both single-integrator kinematics and double-integrator dynamics. In addition, experimental results are provided to validate some theoretical results.
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