Global ETD Search
Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
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Showing 1 to 18 of 18 for “"Small Disturbances"”.
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A novel method for power system stabilizer design
… power system when subjected to both large and small disturbances. Large disturbances are caused by severe changes in the power system, e.g. a short-circuit on a transmission line, loss of a large generator or load, loss of a tie-line between two systems. Small disturbances in the form of load …
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A novel method for power system stabilizer design
… power system when subjected to both large and small disturbances. Large disturbances are caused by severe changes in the power system, e.g. a short-circuit on a transmission line, loss of a large generator or load, loss of a tie-line between two systems. Small disturbances in the form of load …
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Numerical simulations of subsonic aeroelastic behavior and flutter suppression by active control
… behavior may be modeled without restrictions to small disturbances or periodic motions. A vortex-lattice method is used to model the aerodynamics. This method accounts for nonlinear effects associated with high angles of attack, unsteady behavior, and deformations of the wing. The vortex-lattice …
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Chaos Theory, Theology, and Curriculum: Striving Towards the Impossibility of the Gift
<p>It was once thought that small influences could not have a large impact on a grand scale. However, in the 1960s Edward Lorenz discovered that very small disturbances in weather conditions could have a great effect on huge weather systems. With an understanding of chaos theory, which posits that …
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Numerical simulation of a single emitter colloid thruster in pure droplet cone-jet mode
… a satellite's relative position and cancelling small disturbances. One candidate technology that holds promise for these type of missions are colloidal thrusters. These thrusters are electrostatic accelerators which do not rely on gas ionization (plasma), are intrinsically small, and operate at …
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An investigation of the performance of a stationary siphoning type of roof ventilator
… to be approximately linear. It was observed that small disturbances in the air currents around the Ventilator head seriously affect the discharge and that for maximum effectiveness, it is necessary to have ample window opening in the room to be ventilated.
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An experimental demographic approach to exotic plant success: <b>Cynoglossum officinale</b> in its native and introduced ranges
… of insect herbivore pressure and creation of small scale disturbances revealed several important results. First, specialist herbivores reduced plant size and fecundity in Germany, but generalist herbivores had no effect on plant performance in Montana. Second, in both ranges, seedling …
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An experimental demographic approach to exotic plant success: <b>Cynoglossum officinale</b> in its native and introduced ranges
… of insect herbivore pressure and creation of small scale disturbances revealed several important results. First, specialist herbivores reduced plant size and fecundity in Germany, but generalist herbivores had no effect on plant performance in Montana. Second, in both ranges, seedling …
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Numerical study of the nonlinear dynamics of the acoustic drops and bubbles
… together by surface tension and perturbed by small disturbances is of great interest to many researchers. Its essential physical nature is characterized by a nonlinear moving-boundary problem complicated by the interfacial stress interaction between two domains, each governed by their own …
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Load Learning and Topology Optimization for Power Networks
… assesses the robustness of power grids to small disturbances and is used to study the optimal placement of new lines on existing networks as well as the design of radial topologies for new networks.
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Sensitivity Analysis of Partial Differential Equations With Applications to Fluid Flow
… We use model problems to illustrate that small unmodeled disturbances can cause transition through movement or bifurcation of equilibria. We also demonstrate that small wall roughness can lead to transition by causing the linearized system to become unstable. Sensitivity methods are used …
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Autonomous Landing of an Unmanned Aerial Vehicle on an Unmanned Surface Vessel using Model Predictive Control with an Adaptive-Covariance Extended Kalman Filter
… wave-induced USV states, but that higher wave disturbances require a larger number of states in the wave dynamics model along with a lower NIS threshold to ensure efficient filter performance. The results also demonstrate that, once the prediction and control horizons have been properly …
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Improved Dynamical Analysis Tools for DFIG Wind Farms via Traditional and Koopman Linearizations
… negatively impact the response of the grid to disturbances in certain ways due to inherent challenges harnessing the wind as an energy sources. These negative impacts (and the advent of powerful personal computing) require an increase in the sophistication of power system models. Thus, there …
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Modeling of Nonlinear Unsteady Aerodynamics, Dynamics and Fluid Structure Interactions
… the major assumptions such as (1) flat wake, (2) small angle of attack, (3) small disturbances to the mean flow components, and (4) time-invariant free-stream. The kinematics of the wake vortices is simulated numerically while the wake and bound circulation distribution and, consequently, the …
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The dynamics of unsteady strait and sill flow
… of various steady solutions with respect to small disturbances. Of the four types of steady solution, the one in which hydraulic control occurs is found to be the most stable. This is verified by numerical experiments in which the steady, controlled flow is perturbed by disturbances generated …
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Axisymmetric and non-axisymmetric modes of instability for flow between rotating cylinders with a transverse pressure gradient
… case where the annulus between the cylinders is small and the numerical results are confined to the case where the outer cylinder is stationary. In considering the stability of such a system one seeks to determine the reaction of the system when subjected to small disturbances. If the …
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The differences in grass species composition and the effects on fire behaviour in an African mesic savanna
… advantage may be mitigated by landscape scale disturbances, including fire and small disturbances, such as game trails created by animals. Different grass clades appear to differ in productivity and moisture content with Andropogoneae (Themeda triandra and related species) being highly …
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Applications and developments of chemometric methods for process analytical chemistry
… found that the MW spectra are more sensitive to small disturbances in the process variation and it is a better technique for endpoint determination and process upset detection. The NIR spectra does not appear to be as representative of the process, possibly due to the limitations of sampling with …