Thesis (Ph. D.)--University of Texas at Austin, 2005. / Supervisor: Anthony P. Ambler. Vita. Includes bibliographical references.

Thesis (M.S.)--State University of New York at Binghamton, Industrial and Systems Engineering Department, 2006. / Includes bibliographical references.

The aim of this project is to investigate the potential use of multivariable control theory in multi-channel dynamic structural testing. The ideal behaviour of a control system for dynamic testing is analysed and this is used to provide the specifications for control schemes for both sinusoidally derived and random loadings. The need for an integrated multivariable control system approach is shown. An experimental test rig is used to test the applicability of multivariable control methods to dynamic testing. The rig consists of a cantilever beam which can be excited into vibration by two electrodynamic shakers. The displacement on two locations on the beam is measured by Linear Variable Displacement Transducers (LVDTs). The rig is configured to provide the worst possible cross-coupling between different input-output pairs. Analytical modelling of the test is accomplished by regarding the cantilever beam as continuous elastic body. The order of the models, which can be either in state-space or in transfer function matrix form, is a function of the frequency range over which accurate modelling is required. The output variable can be displacement, velocity or force. The analytical modelling led to programs for the simulation of the beam for any given input time series and for a varying number of vibrators and output measurement transducers. The locations of both shakers and output sensors can be varied at will by a procedure which is transparent to the user. The multivariable control methods used for controller design are the characteristic locus and the Nyquist array method with recent extensions. Emphasis waS given during the design process to producing robust performance and stability. Both the characteristic locus and the Nyquist array designs were assessed using singular value decomposition analysis and were found to perform satisfactorily. The merits of both designs are analysed and compared. In the initial stages of the project a considerable amount of time was devoted to developing a C.A.D. package for multivariable control. The features of this package are described. Also software development based on the MATLAB package is discussed.

It is beyond doubt that technology has changed the way people in modern society live their daily lives. While a modern society eagerly adopts new technology, the loss of the services provided by these technologies is hardly ever considered. Therefore, this research project will evaluate the importance of communication technology and how critical it is for an individual. Furthermore, this research will provide a framework to improve the availability of current communication technologies from the perspective of the individual.

Thesis (M.S. in Mechanical Engineering)--Naval Postgraduate School, December 2009. / Thesis Advisor(s): Kwon, Young ; Pollak, Randall. "December 2009." Description based on title screen as viewed on February 1, 2010. Author(s) subject terms: Carbon Nanotube, Thermal Energy Storage Systems, Characterization of Nanofluids, Static Phase Change Materials, Heat Transfer Nanofluid Systems. Includes bibliographical references (p. 73-77). Also available in print.

Thesis (Ph. D.)--Ohio University, August, 1990. / Title from PDF t.p.

Thesis (M.S.)--Ohio University, August, 1997. / Title from PDF t.p.

We theoretically study steady-state nonequilibrium properties of various open electronic systems subject to time-independent external bias. A charge current is established across each system by its coupling to two external particle reservoirs maintained at different chemical potentials. We discuss the impact of intra-reservoir electron correlations on transport, and examine how reservoir-generated dissipation and nonequilibrium-induced decoherence influence these systems. The effect of intra-lead electron interactions on transport is investigated in the context of a phonon-coupled single molecule transistor driven by Luttinger-liquid source and drain leads. The semi-classical master equation approach is used to compute current and noise characteristics of the device for various interaction strengths in the leads. The results suggest the possibility of tuning the Fano factor of the device using intra-lead electron interactions. The Keldysh path integral formalism is used to theoretically formulate models that describe the remaining open nonequilibrium systems. We consider voltage-induced electron-phonon scattering and electron mass enhancement due to phonons in a model metallic system. The possibility of adjusting the acoustic phonon velocity and the Thomas-Fermi screening length with external voltage is discussed. The effects of dissipation is investigated in an open BCS superconducting graphene, where the dissipation-induced rearrangement of its ground state from the BCS superconductor to the Fermi liquid is examined. The results theoretically infer prospects for a voltage-tuned metal-to-BCS quantum phase transition in graphene. Lastly, we develop a theory of nonequilibrium quantum criticality in open itinerant Ising and Heisenberg magnets. Both departures from equilibrium at conventional quantum critical points and the physics of phase transitions induced by the nonequilibrium drive are analyzed.

We theoretically study steady-state nonequilibrium properties of various open electronic systems subject to time-independent external bias. A charge current is established across each system by its coupling to two external particle reservoirs maintained at different chemical potentials. We discuss the impact of intra-reservoir electron correlations on transport, and examine how reservoir-generated dissipation and nonequilibrium-induced decoherence influence these systems. The effect of intra-lead electron interactions on transport is investigated in the context of a phonon-coupled single molecule transistor driven by Luttinger-liquid source and drain leads. The semi-classical master equation approach is used to compute current and noise characteristics of the device for various interaction strengths in the leads. The results suggest the possibility of tuning the Fano factor of the device using intra-lead electron interactions. The Keldysh path integral formalism is used to theoretically formulate models that describe the remaining open nonequilibrium systems. We consider voltage-induced electron-phonon scattering and electron mass enhancement due to phonons in a model metallic system. The possibility of adjusting the acoustic phonon velocity and the Thomas-Fermi screening length with external voltage is discussed. The effects of dissipation is investigated in an open BCS superconducting graphene, where the dissipation-induced rearrangement of its ground state from the BCS superconductor to the Fermi liquid is examined. The results theoretically infer prospects for a voltage-tuned metal-to-BCS quantum phase transition in graphene. Lastly, we develop a theory of nonequilibrium quantum criticality in open itinerant Ising and Heisenberg magnets. Both departures from equilibrium at conventional quantum critical points and the physics of phase transitions induced by the nonequilibrium drive are analyzed.

Thesis (M.S.)--Missouri University of Science and Technology, 2009. / Vita. The entire thesis text is included in file. Title from title screen of thesis/dissertation PDF file (viewed November 25, 2009) Includes bibliographical references (p. 23-24).