Robust Control Design for Large Space Structures

The control design problem for the class of future spacecraft referred to as large space structures (LSS) is by now well known. The issue is the reduced order control of a very high order, lightly damped system with uncertain system parameters, particularly in the high frequency modes. A design methodology which incorporates robustness considerations as part of the design process is presented. Combining pertinent results from multivariable systems theory and optimal control and estimation, LQG eigenstructure assignment and LQG frequency shaping, were used to improve singular value robustness measures in the presence of control and observation spillover

An all monolithic MOS A/D converter - Low power clocks, multiplexers, registers, and A/D converter Final report

Research and developments of monolithic, MOS, ten bit, analog to digital converte

Lost Ground: Neoliberalism, Charter Schools, and the End of Desegregation in St. Louis, Missouri

During the final decades of the twentieth century, U.S. urban education policy experienced a sea change in its orientation toward equity. Mid-century social liberalism and its programs for expanding access to public education resources through desegregation and more equitable funding gave way to neoliberal reforms focused on improving outcomes through deregulation, accountability regimes, and market discipline. Charter schools are the vanguard of neoliberal education reform. While much of the research on charters aims at either substantiating or critiquing their success claims relative to traditional public schools, in this dissertation, I examine the role of charter schools within the larger processes of urbanization. Specifically, I focus on St. Louis, Missouri, where, in 1998, a single piece of education reform legislation (Senate Bill 781) legalized charter schools and set an end for the largest and longest-running school desegregation program in U.S. history. Rather than legalize charters statewide, SB 781 restricted them to St. Louis and Kansas City, Missouri’s only two metropolitan areas to have operated court-enforced desegregation programs. Combining critical policy analysis and economic geography, I link both desegregation and charter schools to urban neoliberalization, arguing that racialized processes of accumulation structured (and continue to structure) uneven development in such a way to make educational equity-based reforms necessary and their failures inevitable. Here too, St. Louis has an important story to tell. With deindustrialization and suburbanization resulting in a 63 percent decline in population in just over 60 years, St. Louis, like many other Rust Belt cities, has wholly embraced neoliberalism’s entrepreneurial ethos. Through public-private partnerships and a portfolio of tax incentives, St. Louis has sacrificed public education in its efforts to attract capital back to the city. Rather than mitigating these issues, the neoliberal restructuring of public education in St. Louis has embraced the same market logics that contributed to educational divestment and school segregation. I argue for a more expansive approach to critical policy analysis in education, one that addresses the limitations of reform within the existing political economy and relocates educational issues and their solutions within a larger struggle for racial and economic justice

Electron paramagnetic resonance studies of slowly tumbling vanadyl spin probes in nematic liquid crystals

An analysis of EPR line shapes by the method of Polnaszek, Bruno, and Freed is made for slowly tumbling vanadyl spin probes in viscous nematic liquid crystals. The use of typical vanadyl complexes as spin probes for nematic liquid crystals is shown to simplify the theoretical analysis and the subsequent interpretation. Rotational correlation times tau and orientational ordering parameters S sub Z where slow tumbling effects are expected to be observed in vanadyl EPR spectra are indicated in a plot. Analysis of the inertial effects on the probe reorientation, which are induced by slowly fluctuating torque components of the local solvent structure, yield quantitative values for tau and S sub Z. The weakly ordered probe VOAA is in the slow tumbling region and displays these inertial effects throughout the nematic range of BEPC and Phase V. VOAA exhibits different reorientation behavior near the isotropic-nematic transition temperature than that displayed far below this transition temperature

ESR studies of the slow tumbling of vanadyl spin probes in nematic liquid crystals

ESR line shapes that are appropriate for slowly tumbling vanadyl spin probes in viscous nematic liquid crystals were calculated by the stochastic Liouville method. Because of the symmetry possessed by vanadyl, the analysis and interpretation of these line shapes was simplified considerably. Spectral line shapes agreed well with experimental spectra of VOAcAc in the nematic liquid crystal Phase V and BEPC. Deviations from Brownian rotational diffusion were noted. A slowly fluctuating torque analysis yielded good agreement with the experimental spectra