The author examines nonlinear aeroelastic responses of air vehicle systems. Herein, the governing equations for a cantilevered configuration are developed and the methods of analysis are explored. Based on the developed nonlinear bending-bending-torsion equations, internal resonance, which is possible in future air vehicles, and the possible cause of limit cycle oscillations of aircraft wings with stores are investigated. The nonlinear equations have three types of nonlinearities caused by wing flexibility, store geometry and aerodynamic stall, and retain up to third-order nonlinear terms. The internal resonance conditions are examined by the Method of Multiple Scales and demonstrated by time simulations. The effect of velocity change for various physical parameters and stiffness ratio is investigated through bifurcation diagrams derived from Poinar´e maps. The dominant factor causing limit cycle oscillations is the stiffness ratio between in-plane and out-of-plane motion.

This thesis analyzes different light localization phenomena in waveguide arrays. We report on the observation of quasi-Bloch oscillations, a new type of dynamic localization in the spatial evolution of light in curved, coupled optical waveguides. The delocalization and final relocalization of an optical beam in a waveguide array is shown by spatially resolving the optical intensity at various propagation distances. Through comparison to different structures, quasi-Bloch oscillations are shown to be robust beyond the nearest-neighbor tight-binding approximation.

This thesis analyzes different light localization phenomena in waveguide arrays. We report on the observation of quasi-Bloch oscillations, a new type of dynamic localization in the spatial evolution of light in curved, coupled optical waveguides. The delocalization and final relocalization of an optical beam in a waveguide array is shown by spatially resolving the optical intensity at various propagation distances. Through comparison to different structures, quasi-Bloch oscillations are shown to be robust beyond the nearest-neighbor tight-binding approximation.

Previous correlations have been established between the El Nino Southern Oscillation (ENSO) and both the tropical north Atlantic sea-surface temperatures (SSTs) and precipitation anomalies in the southeastern and mid-Atlantic states. Both bivariate and partial correlations are used over a five and six-month lag to assess the relevance the tropical Atlantic SSTs have in eastern United States precipitation patterns. Significant correlations between Pacific SSTs and precipitation were found during winter months which agree with previous literature. The relationship with the Atlantic SSTs was less robust, as some significant values were established over three seasons, excluding winter. Only the spring season showed a partial explanation of the Atlantic SST's role in the precipitation's response to Pacific SSTs. These relationships did not occur during the times when significant correlations were made between Pacific SSTs and precipitation. / Department of Geography

<p>We describe the measurement of muon neutrino disappearance due to</p><p>neutrino oscillation using the Tokai-2-Kamiokande (T2K) experiment's Run 1-4 (6.57&times;10<super>20</super> POT)</p><p>data set. We analyze the data using the conventional</p><p>Pontecorvo-Maki-Nakagawa-Sakata (PMNS) mixing</p><p>matrix for the three Standard Model neutrinos. The output of the</p><p>analysis is a measurement of the parameters sin<super>2</super>&theta;₂₃, &Delta;m<super>2</super>₃₂ for the normal hierarchy and sin<super>2</super>&theta;₂₃, &Delta;m<super>2</super>₁₃ for</p><p>the inverted hierarchy. The best-fit oscillation</p><p>parameters for the normal hierarchy are found to be</p><p>(sin<super>2</super>&theta;₂₃, &Delta;m<super>2</super>₃₂) = ( 0.514, 2.51&times;10<super>-3</super> eV<super>2</super>/c<super>4</super>}). The 90% 1D confidence interval -- determined for both parameters</p><p>using the Feldman-Cousins procedure -- is for the normal hierarchy</p><p>0.428 < sin<super>2</super>&theta;₂₃ < 0.598 and</p><p>2.34&times;10<super>-3</super> eV<super>2</super>/c<super>4</super> < &Delta;m<super>2</super>₃₂ < 2.68\times10^{-3} eV<super>2</super>/c<super>4</super>. </p><p>For the inverted hierarchy, the best-fit oscillation parameters are</p><p>(sin<super>2</super>&theta;₂₃, &Delta;m<super>2</super>₁₃) = (0.511, 2.48&times;10<super>-3</super> eV<super>2</super>/c<super>4</super>. The 90\% 1D Feldman-Cousins confidence intervals for the inverted hierarchy are 2.31&times;10<super>-3</super> eV<super>2</super>/c<super>4</super> < \Delta m^2_{13} < 2.64&times;10<super>-3</super> eV<super>2</super>/c<super>4</super>.</p> / Dissertation

A prototype time projection chamber has been designed and constructed to study the performance that can be expected by the large scale time projection chambers in the ND280m detector of the Tokai to Kamioka (T2K) neutrino oscillation experiment. Tests using the prototype will indicate any changes necessary to the fullscale design in order to meet the physics goals of the detectors. Some TPC gas parameters are measured, including the drift velocity, diffusion constant, and electron attachment coefficient. The spatial resolution of the TPC is also measured, and results are presented for two candidate TPC gasses.

Traditional power system stability assessment based on full model computation shows its drawbacks in real-time applications where fast variations are present at both demand side and supply side. This work presents the use of data mining techniques, in particular the Decision Trees (DTs), for fast evaluation of power system oscillatory stability and voltage stability from synchrophasor measurements. A regression tree-based approach is proposed to predict the stability margins. Modal analysis and continuation power flow are the tools used to build the knowledge base for off-line DT training. Corresponding metrics include the damping ratio of critical electromechanical oscillation mode and MW-distance to the voltage instability region. Classification trees are used to group an operating point into predefined stability state based on the value of corresponding stability indicator. A novel methodology for knowledge base creation has been elaborated to assure practical and sufficient training data. Encouraging results are obtained through performance examination. The robustness of the proposed predictor to measurement errors and system topological variations is analyzed. A scheme has been proposed to tackle the problem of when and how to update the data mining tool for seamless online stability monitoring. The optimal placement for the phasor measurement units (PMU) based on the importance of DT variables is suggested. A measurement-based voltage stability index is proposed and evaluated using field PMU measurements. It is later revised to evaluate the impact of wind generation on distribution system voltage stability. Next, a new data mining tool, the Probabilistic Collocation Method (PCM), is presented as a computationally efficient method to conduct the uncertainty analysis. As compared with the traditional Monte Carlo simulation method, the collocation method could provide a quite accurate approximation with fewer simulation runs. Finally, we show how to overcome the disadvantages of mode meters and ringdown analyzers by using DTs to directly map synchrophasor measurements to predefined oscillatory stability states. The proposed measurement-based approach is examined using synthetic data from simulations on IEEE test systems, and PMU measurements collected from field substations. Results indicate that the proposed method complements the traditional model-based approach, enhancing situational awareness of control center operators in real time stability monitoring and control.

The theory of time scales is introduced by Stefan Hilger in his PhD thesis in 1998 in order to unify continuous and discrete analysis. In our thesis, by making use of the time scale calculus we study the oscillation of nonlinear matrix differential equations of second order. the first chapter is introductory in nature and contains some basic definitions and tools of the time scales calculus, while certain well-known results have been presented with regard to oscillation of the solutions of second order matrix equations and some new oscillation criteria for the same type equations have been established in the second chapter.

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In this thesis, a reversible Lotka-Volterra model was proposed to study the nonlinear oscillation of the Belousov-Zhabotinsky(BZ) reaction in a closed isothermal chemical system. The reaction zone can be divided into two zones, oscillation zone and transition zone, where the oscillation time and the transition time and the number of the complete oscillations are estimated. By applying the geometric singular perturbation method, it was proved that there exist an oscillation axis in the oscillation zone, a strongly stable two-dimensional invariant manifold in transition zone, on which there is also a one-dimensional stable invariant manifold, which is the part of the central axis. There is no oscillation in the vicinity of the equilibrium, as indicated by Onsager's reciprocal symmetry relation. Furthermore, the damped oscillation is studied in terms of the action-action-angle variables. In the end, the model reference control technique is employed to control the oscillation amplitude in the BZ reaction.