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This paper defines a variable transfer function that is used to compensate for low frequency structural resonances in a turret so that stabilization of a closed loop servo system can be achieved. Three circuits for implementing this compensation are presented. They are: the feedforward three amplifier biquad, the summing four amplifier biquad, and the single amplifier biquad with pole-zero cancellation. Design equations allowing the engineer to go directly from the given transfer function to the actual component values are developed for each circuit. A comparison of the final circuit designs is also presented.

<p>The synthesis of novel oxadiazole antibiotics more water soluble than previously published analogues within the group will be discussed in this thesis as part of synthesizing a library with increased sp3 character.  These analogues were tested against S. aureus and MRSA strains to determine the most active compounds then percent hemolysis confirmed little RBC lysis among the compounds.  Synergistic activity was also tested for HSGN-2241 previously synthesized within the group.  Biofilm eradication assays were completed for HSD 1919 alongside time kill assays.</p>

This dissertation studies the feedback control of the dynamic response of multi-story structures to seismic excitations. The seismic excitations are represented by arbitrary unknown stochastic disturbances. The research consists of modeling of the structure with a control system and a control design in the state space. A combination of the extended Hamilton's principle and the Hierarchical Finite Element Method (HFEM) was used to derive the discrete differential equations of motion. This method exhibits superior accuracy with fewer degrees of freedom (DOF). The discrete equation were realized in the state space, where the Multiple Channel Control (MCC) model, the Single Channel Control (SCC) model and the Special Single Channel Control (SSCC) model were proposed. The MCC model is a general multiple input/multiple output (MIMO) dynamic system; the SSCC model is a single input/multiple output (SIMO) dynamic system; which requires only one actuator acting on the base; the SCC model has duality. On one hand, the system can be classified as MIMO when control actuators are regarded as the input. On the other hand, it can be regarded as a SIMO system when control signal as the input. Moreover, three different types of control methodologies, the Linear Quadratic Gaussian (LQG) control, the Disturbance Accommodating Control (DAC), and the hybrid LQG/DAC approaches, were successfully developed to actively mitigate the vibration of the multi-story structures subjected to the seismic disturbance. In addition, the Kalman filter was used as an optimal observer to estimate the state of the system in the LQG and the LQG/DAC design. Finally a numerical simulation of a four-story structure was carried out under nine cases. The cases covered various combinations of the three models and the three control designs to verify the effectiveness of control technique developed in this study. The simulation results found were quite encouraging. The results show each combination has its preponderance corresponding to special priority. In general, the hybrid LQG/DAC control in conjunction with the SSCC model is the best choice. / Ph. D.

An active network is a computer network in which new protocols can be installed at run-time in any node within the network. For example, the deployment of Internet multicast technology has been slow because service providers have been reluctant to upgrade and reconfigure their routing nodes. Under the active network scheme, users who desire multicast services can have the service automatically installed without any direct intervention by the user or the provider. One major question in realizing active networks is how the code for the new active library can be found, or resolved, and retrieved. A model of the resolution and retrieval mechanisms is the major focus of this research. To validate the model, a proof-of-concept experimental system that realizes a simple active network architecture was developed. An active library resolution service model, suitable for a global Internet, was investigated using this experimental platform and a simulation system. The two protocol components that were built and studied are the active transport protocol and the active library resolution protocol. The experimental and simulation systems were used to evaluate the extensibility, overhead, resolution time, scalability, and policy constraint support of the service. Extensibility and policy constraint support are an integral part of the proposed design. For libraries located on servers that are at most ten hops away from the requesting source, the resolution time is under 2.6 seconds. Simulations of networks of different sizes and with different error rates exhibit linear resolution time and overhead characteristics, which indicates potential scalability. Behavior under high loss rates showed better than expected performance. The results indicate that the library resolution concept is feasible and that the proposed strategy is a good solution. / Ph. D.

Recently much research has focused on the control of enclosed sound fields, particularly in automobiles. Both Active Noise Control (ANC) and Active Structural Acoustic Control (ASAC) techniques are being applied to problems stemming from power train noise and road noise (noise due to the interaction of the tires with the surface of the road). Due to the low frequency characteristics of these noise problems, large acoustic sources are required to obtain efficient control of the sound field. This creates demand in the automobile industry for compact lightweight sources. This work is concerned with the application of active control to power train noise, as well as road noise in the interior cabin of a sport utility vehicle using advanced, compact lightweight piezoelectric acoustic sources. First, a test structure approximately the same size as the automobile was built to study the principles of active noise control in a cavity. A finite element model of the cavity was created in order to optimize the positions of the error sensors and the control sources. Experimental work was performed with the optimized actuator and sensor locations in order to validate the model, and draw conclusions regarding the conditions to obtain global control of the sound field. Second, a broad-band feedforward filtered-X LMS algorithm was used to control power train noise. Preliminary power train noise tests were conducted using arrangements of four microphones and up to four commercially available speakers for control. Attenuation of seven decibel (dB) at the error sensors was measured in the 40-500 Hz frequency band. The dimensions of the zone of quiet generated by the control were measured, and show that noise reductions were obtained for a large volume surrounding the error sensors. Next, advanced speakers were implemented for active control of power train noise. The results obtained with different arrangements of these speakers were very similar to those obtained with the commercially-available speakers. These advanced speakers use piezoelectric devices to induce the displacement of a speaker membrane, which radiates sound. Their lighter weight and compact dimensions are a significant advantage over conventional speakers, for their application in automobile. Third, preliminary results were obtained for active control of road noise. The controller used an optimized set of four reference signals to control the noise at one error sensor using one control source. Two sets of tests were conducted. The first set of tests was performed on a dynamometer, which simulates the effects of the road on the tires. The second set of tests was performed on a rough road. Reduction of two to four decibel of the sound pressure level at the error sensor was obtained between 100 and 200 Hz. / Master of Science