Simulating transient compressible flows involving shock waves presents challenges to the CFD practitioner in terms of the mesh quality required to resolve discontinuities and prevent smearing. This document discusses a novel two-dimensional Cartesian anisotropic mesh adaptation technique implemented for transient compressible flow. This technique, originally developed for laminar incompressible flow, is efficient because it refines and coarsens cells using criteria that consider the solution in each of the cardinal directions separately. In this document the method will be applied to compressible flow. The procedure shows promise in its ability to deliver good quality solutions while achieving computational savings. Transient shock wave diffraction over a backward step and shock reflection over a forward step are considered as test cases because they demonstrate that the quality of the solution can be maintained as the mesh is refined and coarsened in time. The data structure is explained in relation to the computational mesh, and the object-oriented design and implementation of the code is presented. Refinement and coarsening algorithms are outlined. Computational savings over uniform and isotropic mesh approaches are shown to be significant.

<p>This final year project describes the linearisation method Cartesian feedback and the design of such a feedback with a 2.4GHz power amplifier. </p><p>To investigate the functionality of the Cartesian feedback ideal blocks with no current consumption were made and then gradually analog circuits were introduced into the feedback. The Cartesian feedback design consists of a subtracter, a modulator and a preamplifier in the top path and a demodulator and a filter in the feedback path. The blocks that are discussed in this report are the subtracter and the modulator unit. The circuits are designed in a 0.35µm SiGe BiCMOS technology. </p><p>The result of the Cartesian feedback showed an increase in 1dB compression point by 6.2dBm and the IMD was improved by 17dB.</p>

This paper seeks to forge a grounds for conversation between the affective turn in contemporary theory and a vital materialist ontology. This conversation focuses on materials and their affects through the experience of weirdness. I use weirdness to describe a register of enchantment which is disruptive and alienating, rather than enticing and delightful. The project is motivated by a desire for ways to think about our relationship to the natural world that afford for fuller experiences of perception. The paper works through four major sections; the first three form a conceptual framework while the fourth is an exercise in mobilizing the concepts through subjective readings of affect. It begins by establishing a concept of vitalism with which to think about interactions with a moving, active world and, in following vitalism across borders of embodied flora and fauna, agitates the notion of what constitutes life. To put vitalism into a dynamic of engagement between entities, I then chart processes of affect through various conditions and situations, such as haunting, hallucination, anticipation and psychotropics. I then address the concept of the event in order to trace the contours of affect as it manifests through situated, temporal passages of force. This conceptual netting culminates in episodic readings of affective experiences, taking a kaleidoscopic form oriented toward anxious fascination. / text

I argue that despite the fact that there can be no strong refutation of skepticism it remains that ignoring skeptical hypotheses and relying on one’s sensory experience are both sound epistemic practices. This argument comes in the form of arguing that we are justified in ignoring skeptical hypotheses on the grounds that (1) they are merely logically possible, and (2) the merely logically possible is rarely relevant in the context of everyday life. I suggest that (2) is true on the grounds that the context of everyday life is one in which our epistemic pursuit of truth is mixed with other pragmatic goals. The result of this mix is that the pursuit of truth can conflict with our goal of avoiding error in such a way that we must choose to prioritize one goal over the other. The above choice implies that skepticism comes at an epistemic cost not acknowledge in the contemporary literature on external world skepticism. This epistemic cost of skepticism means that the relative risk of error involved in relying on sensory experience is not as epistemically problematic as has often been assumed. These considerations allow an anti-skeptical position in which relying on sensory experience is prima-facie justified despite the possibility of being a brain in a vat. In this paper I explore what such a position might look like and what the implications of such a view might be for relevant alternatives positions, the closure debate, and the concept of differing epistemic perspectives in contemporary epistemology.

A Cartesian method for solution of the steady two-dimensional Euler equations is produced. Dynamic data structures are used and both geometric and solution-based adaptations are applied. Solution adaptation is achieved through solution-based gradient information. The finite volume method is used with cell-centered approach. The solution is converged to a steady state by means of an approximate Riemann solver. Local time step is used for convergence acceleration. A multistage time stepping scheme is used to advance the solution in time. A number of internal and external flow problems are solved in order to demonstrate the efficiency and accuracy of the method.

Viscoelastic fluid flow with immersed boundaries of complex geometry is widely found both in nature and engineering processes. Examples include haemocytes moving in human blood flow, self-propulsion of microscopic organisms in complex liquids, hydraulic fracturing with sand in oil flow, and suspension flow with viscoelastic medium. Computational modelling of such systems is important for understanding complex biological processes and assisting engineering designs. Conventional simulation methods use conformed meshes to resolve the boundaries of complex geometry. Dynamically updating the conformed mesh is computationally expensive and makes parallelization difficult. In comparison, Cartesian grid methods are more promising for large scale parallel simulation. Using Cartesian grid methods to simulate viscoelastic fluid flow with complex boundaries is a relatively unexplored area. In this thesis, a sharp interface Cartesian grid method (SICG) and a smoothed interface immersed boundary method (SIIB) are developed in order to simulate viscoelastic fluids in complex geometries. The SICG method shows a better prediction of the stress on stationary boundaries while the SIIB method shows reduced non-physical oscillations in the computation of drag and lift forces on moving boundaries. Parallel implementations of both solvers are developed. Convergence of the numerical schemes is shown and the implementations are validated with a few benchmark problems with both stationary and moving boundaries. This study also focuses on the simulation of flows past 2D cylindrical or 3D spherical particles. Lateral migration of particles induced by inertial and viscoelastic effects are investigated with different flow types. Equilibrium positions of inertia-induced migration are reported as a function of the particle Reynolds number and the blockage ratio. The migration in the viscoelastic fluid is simulated from zero elastic number to a finite elastic number. The inclusion of both inertial and viscoelastic effects on the lateral migration of a particle is the first of its kind. New findings are reported for the equilibrium positions of a spherical particle in square duct flow, which suggest the need for future experimental and computational work.

Title: Reasoning in Description Logics Author: Mgr. Jaromír Malenko Department: Department of Theoretical Computer Science and Mathematical Logic, Faculty of Mathematics and Physics, Charles University in Prague Supervisor: Prof. RNDr. Petr Štěpánek, DrSc.; Department of Theoretical Computer Science and Mathematical Logic, Faculty of Mathematics and Physics, Charles University in Prague Keywords: Description logic, Reasoner, Cartesian product, Non-monotonic reasoning Abstract: We deal with several aspects of reasoning in Description Logics. First, since description logic (DL) is a subset of First Order Logic (FOL), we use a FOL reasoner to reason in DL. We implemented dl2fol, a DL reasoner that takes an ontology (a DL theory with rules), translates it into a FOL theory, passes this set of formulae to an underling FOL reasoner, and interprets the result in terms of given ontology. This is an effective method for reasoning with newly introduced language constructors. However, we observed longer running times and that satisfiability of some DL concepts wasn't proved due to FOL undecidability. Second, we extend two DLs by introducing new language construct: cartesian product (CP) of concepts and roles. This allows for expressing relationships, that are not expressible by other means in weaker DLs. We...

A grande maioria dos robôs industriais disponíveis no mercado é de alto desempenho, principalmente com relação à precisão de posicionamento. Este aspecto é um dos fatores que mais influencia no seu preço final, levando em consideração toda a complexa cadeia de elementos que fazem com que o robô opere corretamente, desde os motores e componentes mecânicos, passando pela arquitetura e sistemas de controle até o sistema de programação. Tendo isto em vista, este trabalho visa projetar um robô industrial com preço mais acessível, adequado para o uso em processos industriais que não necessitem altos níveis de precisão. Para a redução de custos de fabricação e de componentes do robô, este trabalho viabiliza o uso de atuadores pneumáticos lineares como fonte motriz, pois os mesmos são relativamente baratos, leves, não poluentes, de fácil montagem e operação, além de apresentarem uma boa relação peso/potência. Para tanto, foi implementado uma estratégia de controle por modos deslizantes com objetivo de superar as dificuldades impostas pelo comportamento não-linear dos componentes pneumáticos. Com relação à redução de custos de programação e operação do robô, desenvolveu-se um ambiente de programação off-line, através de softwares de auxilio à manufatura e de engenharia usualmente encontrados em ambientes industriais. A estratégia fundamental neste trabalho, foi o desenvolvimento de uma metodologia de projeto própria, concebida especificamente para a aplicação em projetos de robôs industriais, com os atributos de facilidade de execução e modularidade das fases envolvidas. A qual, no presente trabalho, apresenta o desenvolvimento de um robô cartesiano com três graus de liberdade acionado por atuadores pneumáticos lineares. / The great majority of industrial robots available in the market have high performance, especially relative to position accuracy. This aspect is one of the factors that most influence its final price, taking into account all complicated web elements that makes the robot operates in the correct form, since the actuators and the constructive part, passing by the architecture and control systems until the system of programming. According to these, the present work aims to project an industrial robot with more accessible costs, adequate to use in industrial process that not require high level of accuracy. For the reduction of manufacture and components costs of the robot, this work make viable to use of pneumatic actuators like a motive source, because are relatively cheap, light, not pollutants, easy assembly and operation, besides presenting a good relation weight/power. For such purpose, the strategy of control was implemented by sliding mode control for the objective to surpass the difficulties imposed by the non-linear behavior of the pneumatic components. About the reduction of programming and operation costs of the robot, an off-line programming environment was developed through manufacturing aided software and a software of engineering both usually found in industrial environments. The basic strategy in this work, was the development of an own methodology of project, conceived specifically for the application in projects of industrial robots, with the attributes of easiness of execution and modularization of the wrapped phases. That methodology, in the present work, presents the development of a Cartesian robot with three degrees of freedom actuated by pneumatic servo drive.

A grande maioria dos robôs industriais disponíveis no mercado é de alto desempenho, principalmente com relação à precisão de posicionamento. Este aspecto é um dos fatores que mais influencia no seu preço final, levando em consideração toda a complexa cadeia de elementos que fazem com que o robô opere corretamente, desde os motores e componentes mecânicos, passando pela arquitetura e sistemas de controle até o sistema de programação. Tendo isto em vista, este trabalho visa projetar um robô industrial com preço mais acessível, adequado para o uso em processos industriais que não necessitem altos níveis de precisão. Para a redução de custos de fabricação e de componentes do robô, este trabalho viabiliza o uso de atuadores pneumáticos lineares como fonte motriz, pois os mesmos são relativamente baratos, leves, não poluentes, de fácil montagem e operação, além de apresentarem uma boa relação peso/potência. Para tanto, foi implementado uma estratégia de controle por modos deslizantes com objetivo de superar as dificuldades impostas pelo comportamento não-linear dos componentes pneumáticos. Com relação à redução de custos de programação e operação do robô, desenvolveu-se um ambiente de programação off-line, através de softwares de auxilio à manufatura e de engenharia usualmente encontrados em ambientes industriais. A estratégia fundamental neste trabalho, foi o desenvolvimento de uma metodologia de projeto própria, concebida especificamente para a aplicação em projetos de robôs industriais, com os atributos de facilidade de execução e modularidade das fases envolvidas. A qual, no presente trabalho, apresenta o desenvolvimento de um robô cartesiano com três graus de liberdade acionado por atuadores pneumáticos lineares. / The great majority of industrial robots available in the market have high performance, especially relative to position accuracy. This aspect is one of the factors that most influence its final price, taking into account all complicated web elements that makes the robot operates in the correct form, since the actuators and the constructive part, passing by the architecture and control systems until the system of programming. According to these, the present work aims to project an industrial robot with more accessible costs, adequate to use in industrial process that not require high level of accuracy. For the reduction of manufacture and components costs of the robot, this work make viable to use of pneumatic actuators like a motive source, because are relatively cheap, light, not pollutants, easy assembly and operation, besides presenting a good relation weight/power. For such purpose, the strategy of control was implemented by sliding mode control for the objective to surpass the difficulties imposed by the non-linear behavior of the pneumatic components. About the reduction of programming and operation costs of the robot, an off-line programming environment was developed through manufacturing aided software and a software of engineering both usually found in industrial environments. The basic strategy in this work, was the development of an own methodology of project, conceived specifically for the application in projects of industrial robots, with the attributes of easiness of execution and modularization of the wrapped phases. That methodology, in the present work, presents the development of a Cartesian robot with three degrees of freedom actuated by pneumatic servo drive.

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