The digital photography is still trying to catch-up with its analogous counterpart and recording light direction is one of the most recent area of interest. The first and still the only one light-field camera for consumers, the Lytro camera, has reached market in 2011. This work introduces the light-field theory and recording with special emphasis on illustrating the principles in 2D, gives an overview of current hardware and ongoing research in the area and analyses the Lytro camera itself, describing the closed file formats and protocols it uses so that further research can be conducted. An important contribution of the work is a .NET portable library for developers, supplemented by a file editor as well as an application for wireless communication with the camera based on the library. Finally, the theory is used to discuss implications for light-field registration and linear panoramas. Powered by TCPDF (www.tcpdf.org)

We have studied magnetic properties of the intermetallic NdPd5Al2 com- pound by means of specific heat and magnetization measurements and neutron scattering. The compound crystallizes in the tetragonal I4/mmm space group with lattice parameters a =4.147 ˚A and c =14.865 ˚A, orders antiferromagnet- ically below TN =1.3 K and presents large magnetocrystalline anisotropy due to the crystal-field effects. The obtained magnetic phase diagram is charac- terized by two distinct magnetically ordered phases similarly to structurally re- lated tetragonal RTX5 and R2TX8 compounds. The zero-field antiferromagnetic phase is characterized by the propagation vector k = (1 2 00) and antiferromag- netic coupling of Nd moments along the teragonal c-axis with the amplitude of magnetic moments of 2.22 µB/Nd as was revealed by neutron diffraction. The transition from the paramagnetic to magnetically ordered in zero field is the first-order phase transition. The CF excitations in NdPd5Al2 were detected by means of INS at 3.0 meV, 7.4 meV, 8.6 meV and 17.1 meV. We further compare our findings about CF in NdPd5Al2 obtained from INS, susceptibility analysis and first-principles calculations and confront them with the experimental mag- netization and magnetic specific heat data. Our results will be also discussed with respect to related...

The master thesis studies the impact of the entropy gradient on the vorticity of ve- locity field, particularly by applying the linear momentum balances. These balances are formulated for Thermo-viscous fluids (later fluids) and Thermo-viscous-elastic ma- terial (later solids) with the other balances (energy, mass, etc.). In order to derive these balances, the Classical continuum mechanics approach is used along with the respec- tive Variational principles. The thesis emphasizes the Variational principles applica- tion representing the modification of the Bateman principle [Bat29] and its comparison with the Classical approach, linked to the L. Crocco work [Cro37], particularly in the case of vorticity generation. It is pointed that by the definition of the dissipative en- tropy sdis a harmony of both approaches can be achieved and that, in the case of an appropriate limit, the direct effect of the entropy gradient on the vorticity of velocity field can be demonstrated. By applying this conclusion the relationship between the change of circulation among a closed curve and released heat on the given geometry is indicated.

El cáncer colorrectal (CCR) constituye en la actualidad la neoplasia más frecuente en España. Hasta un 30% de los casos de CCR se incluyen dentro del CCR familiar y alrededor de un 3-5% se deben a mutaciones en genes de elevada penetrancia que siguen una herencia mendeliana Éstos últimos incluyen al CCR hereditario no polipósico: principalmente el Síndrome de Lynch (SL), debido a mutaciones germinales en los genes de sistema reparador de errores (MMR) MLH1, MSH2, MSH6 y PMS2; y varios síndromes polipósicos, como la poliposis adenomatosa familiar, asociada al gen APC y la poliposis asociada al gen MUTYH. En aproximadamente un 70% de los casos analizados de pacientes con sospecha de SL no se encuentran mutaciones germinales y en torno a un 10% de estos casos, con pérdida de expresión de MLH1 e hipermetilación del promotor de dicho gen en su tumor, se explican por epimutaciones constitucionales en MLH1. No obstante, la prevalencia de este fenómeno en la población general es desconocida. También existen casos de CCR con elevada carga familiar, pero sin alteración del sistema MMR, de los que se desconoce su origen genético (CCR familiar tipo X). Lo mismo ocurre para algunos casos de poliposis adenomatosa con agregación familiar, que no se explican por mutaciones en los genes APC o MUTYH. Recientemente se han descrito dos mutaciones recurrentes en los genes POLE y POLD1 (p.Leu424Val y p.Ser478Asn respectivamente) como responsables de un pequeño porcentaje de estos casos de CCR y poliposis no clasificados pero, debido a la escasez de casos descritos hasta la fecha, fenotipo clínico exacto no se ha definido. Así, los objetivos de este trabajo han sido: en primer lugar, determinar la prevalencia de las epimutaciones constitucionales en MLH1 como una causa de SL en una serie no seleccionada de CCR y compararla con la prevalencia de este fenómeno en una serie seleccionada; y en segundo lugar, analizar la prevalencia de las mutaciones recurrentes en los genes POLE y POLD1 en casos de CCR y poliposis familiar de aparición temprana, sin mutación en los genes responsables de los síndromes de sospecha, y así contribuir a definir el fenotipo clínico asociado a las mutaciones en dichos genes. Se evaluó la prevalencia de epimutaciones constitucionales de MLH1 en una cohorte de CCR no seleccionado, y se comparó con una cohorte de CCR familiar seleccionado. Así, no se detectaron epimutaciones constitucionales en MLH1 en la población no seleccionada. No obstante, el 15,6% de la serie seleccionada fueron positivos para epimutaciones en MLH1. Por otro lado, se realizó la búsqueda de mutaciones recurrentes en POLE y POLD1 en casos de CCR y/o poliposis familiar mediante ensayos de genotipado KASPar y/o secuenciación Sanger. Se identificó la mutación POLE_p.Leu424Val como mutación de novo, ningún caso presentó la mutación POLD1_p.Ser478Asn, pero se identificó una nueva mutación en POLD1: p.Leu474Pro, con patogenicidad sustentada mediante diversas aproximaciones, en una familia de CCR familiar tipo X con también casos de cáncer de endometrio. Así, estos resultados sugieren una prevalencia insignificante de epimutaciones constitucionales en MLH1 en cohortes no seleccionadas de CCR. Así, el análisis de epimutación constitucional en MLH1 debería dirigirse exclusivamente a pacientes que cumplen los criterios revisados de Bethesda y cuyo tumor presente pérdida de expresión y metilación de MLH1. Por otro lado, las mutaciones en POLE y POLD1 explican una pequeña proporción de casos de CCR y poliposis familiar. La secuenciación de al menos estas mutaciones recurrentes debería considerarse en el diagnóstico genético rutinario de los casos con sospecha de CCR o poliposis hereditarios, sin mutaciones en los genes de sospecha clásicos.

In this thesis, we have explained the different types of DAC (Digital-to-Analog) architectures and their advantages and disadvantages. We have mainly focused on current-steering digital-to-analog design for achieving high speed and high performance. The current-steering DAC is designed using binary weighted architecture. The benefits of this architecture is that it occupies less area, consumes less power and the number of control signals required are very less. The requirements for high speed and high performance DAC are discussed in detail. The circuit is implemented in a state-of-the-art 65 nm process, with a supply voltage of 1.2 V and at a sampling speed of 2 GHz. The resolution of the DAC is 8-bits. The design of 8-bit current-steering DAC converts 8 most significant bits (MSBs) into their binary weighted equivalent, which controls 256 unit current sources. The performance of the DAC is measured using the static and dynamic  parameters. In communication applications the static performance measures such as INL and DNL are not of utmost importance. In this work, we have mainly concentrated on the dynamic performance characteristics like SNR (Signal to Noise Ratio) and SFDR (Spurious Free Dynamic Range). For measuring the dynamic parameters, frequency domain analysis is a better choice. Also, we have discussed how the pole-zero analysis can be used to arrive at the dynamic performance metrics of a unit element of the DAC at higher frequencies. Different methods were discussed here to show the effects of poles and zeroes on the output impedance of a unit element at higher frequencies, for example, by hand calculation, using Mathematica and by using cadence. After extensive literature studies, we have implemented a technique in cadence, to increase the output impedance at higher frequencies. This technique is called as “complimentary current solution technique”. This technique will improve the output impedance and SFDR compared to the normal unit element design. Our technique contains mostly analog building blocks, like, current mirrors, biasing scheme and switching scheme and few digital blocks like D-ff (D-flip flop). The whole system is simulated and verified in MATLAB. Dynamic performances of the DAC such as SNR and SFDR are found with the help of MATLAB.

<p>An on-line identifier using Functional Link Network (FLN) and Pole-shift (PS) controller for power system stabilizer (PSS) application are presented in this thesis. To have the satisfactory performance of the PSS controller, over a wide range of operating conditions, it is desirable to adapt PSS parameters in real time. Artificial Neural Networks (ANNs) transform the inputs in a low-dimensional space to high-dimensional nonlinear hidden unit space and they have the ability to model the nonlinear characteristics of the power system. The ability of ANNs to learn makes them more suitable for use in adaptive control techniques.</p> <p>On-line identification obtains a mathematical model at each sampling period to track the dynamic behavior of the plant. The ANN identifier consisting of a Functional link Network (FLN) is used for identifying the model parameters. A FLN model eliminates the need of hidden layer while retaining the nonlinear mapping capability of the neural network by using enhanced inputs. This network may be conveniently used for function approximation with faster convergence rate and lesser computational load.</p> <p>The most commonly used Pole Assignment (PA) algorithm for adaptive control purposes assign the pole locations to fixed locations within the unit circle in the z-plane. It may not be optimum for different operating conditions. In this thesis, PS type of adaptive control algorithm is used. This algorithm, instead of assigning the closed-loop poles to fixed locations within the unit circle in the z-plane, this algorithm assumes that the pole characteristic polynomial of the closed-loop system has the same form as the pole characteristic of the open-loop system and shifts the open-loop poles radially towards the centre of the unit circle in the z-plane by a shifting factor &alpha; according to some rules. In this control algorithm, no coefficients need to be tuned manually, so manual parameter tuning (which is a drawback in conventional power system stabilizer) is minimized. The PS control algorithm uses the on-line updated ARMA parameters to calculate the new closed-loop poles of the system that are always inside the unit circle in the z-plane.</p> <p>Simulation studies on a single-machine infinite bus and on a multi-machine power system for various operating condition changes, verify the effectiveness of the combined model of FLN identifier and PS control in damping the local and multi-mode oscillations occurring in the system. Simulation studies prove that the APSSs have significant benefits over conventional PSSs: performance improvement and no requirement for parameter tuning.</p>

This report presents a new way of control engineering. Dc motor speed controlled by three controllers PID, pole placement and Fuzzy controller and discusses the advantages and disadvantages of each controller for different conditions under loaded and unloaded scenarios using software Matlab. The brushless series wound Dc motor is very popular in industrial application and control systems because of the high torque density, high efficiency and small size. First suitable equations are developed for DC motor. PID controller is developed and tuned in order to get faster step response. The simulation results of PID controller provide very good results and the controller is further tuned in order to decrease its overshoot error which is common in PID controllers. Further it is purposed that in industrial environment these controllers are better than others controllers as PID controllers are easy to tuned and cheap. Pole placement controller is the best example of control engineering. An addition of integrator reduced the noise disturbances in pole placement controller and this makes it a good choice for industrial applications. The fuzzy controller is introduce with a DC chopper to make the DC motor speed control smooth and almost no steady state error is observed. Another advantage is achieved in fuzzy controller that the simulations of three different controllers are compared and concluded from the results that Fuzzy controller outperforms to PID controller in terms of steady state error and smooth step response. While Pole placement controller have no comparison in terms of controls because designer can change the step response according to nature of control systems, so this controller provide wide range of control over a system. Poles location change the step response in a sense that if poles are near to origin then step response of motor is fast. Finally a GUI of these three controllers are developed which allow the user to select any controller and change its parameters according to the situation.

<p>An on-line identifier using Functional Link Network (FLN) and Pole-shift (PS) controller for power system stabilizer (PSS) application are presented in this thesis. To have the satisfactory performance of the PSS controller, over a wide range of operating conditions, it is desirable to adapt PSS parameters in real time. Artificial Neural Networks (ANNs) transform the inputs in a low-dimensional space to high-dimensional nonlinear hidden unit space and they have the ability to model the nonlinear characteristics of the power system. The ability of ANNs to learn makes them more suitable for use in adaptive control techniques.</p> <p>On-line identification obtains a mathematical model at each sampling period to track the dynamic behavior of the plant. The ANN identifier consisting of a Functional link Network (FLN) is used for identifying the model parameters. A FLN model eliminates the need of hidden layer while retaining the nonlinear mapping capability of the neural network by using enhanced inputs. This network may be conveniently used for function approximation with faster convergence rate and lesser computational load.</p> <p>The most commonly used Pole Assignment (PA) algorithm for adaptive control purposes assign the pole locations to fixed locations within the unit circle in the z-plane. It may not be optimum for different operating conditions. In this thesis, PS type of adaptive control algorithm is used. This algorithm, instead of assigning the closed-loop poles to fixed locations within the unit circle in the z-plane, this algorithm assumes that the pole characteristic polynomial of the closed-loop system has the same form as the pole characteristic of the open-loop system and shifts the open-loop poles radially towards the centre of the unit circle in the z-plane by a shifting factor &alpha; according to some rules. In this control algorithm, no coefficients need to be tuned manually, so manual parameter tuning (which is a drawback in conventional power system stabilizer) is minimized. The PS control algorithm uses the on-line updated ARMA parameters to calculate the new closed-loop poles of the system that are always inside the unit circle in the z-plane.</p> <p>Simulation studies on a single-machine infinite bus and on a multi-machine power system for various operating condition changes, verify the effectiveness of the combined model of FLN identifier and PS control in damping the local and multi-mode oscillations occurring in the system. Simulation studies prove that the APSSs have significant benefits over conventional PSSs: performance improvement and no requirement for parameter tuning.</p>

This thesis presents a systematic scheme to design the optimal efficiency operations and axial force control of a single-sided permanent-magnet axial-flux motor with center pole (SPAMC) through the detailed mathematical model and operational analysis. According to the rotating magnetic field theory combining with the recoil line characteristics of permanent magnet and the magnetic equivalent circuit, appropriate projection of the stator currents to achieve the optimal efficiency operations and axial force control can be realized. From these evaluations, a feasible operational guidance for SPAMC field oriented control (FOC) framework can be successfully developed. Finally, based on the proposed operational scheme, a DSP-based drive system has been successfully implemented, and the optimal efficiency operations and axial force control objectives can be achieved.

In this thesis, an LMI-based pole-clustering characterization for descriptor systems is investigated. A necessary and sufficient condition for checking simultaneously the regularity, impulse immunity, and finite eigenvalues locating in the generalized LMI regions is derived. Since uncertainty exists inevitably in control systems, we propose two sufficient conditions to guarantee the robust pole clustering in the generalized LMI regions for uncertain descriptor systems with two types of uncertainties, i.e. the norm bounded uncertainty and the convex polytopic uncertainty. The LMI-based state feedback controller design methods are developed as well. Finally, the validity and the feasibility of our theoretical results are verified by the numerical simulation results of several examples.