<p> The dual configuration is innovated as a new approach in sensitivity reduction. Three types of sensitivity due to variations in plant parameters are discussed. It has been shown that cost insensitive and terminal insensitive designs are indeed achievable by applying the dual configuration to implement the optimal control. </p> <p> The theory has been developed for a general class of optimal systems and the linear systems with quadratic cost functionals have been analytically evaluated to illustrate the theory. </p> / Thesis / Master of Engineering (ME)

As device feature sizes shrink to nano-scale, continuous technology scaling has led to a large increase in parameter variability during semiconductor manufacturing process. According to the source of uncertainty, parameter variations can be classified into three categories: process variations, environmental variations, and temporal variations. All these variation sources exert significant influences on circuit performance, and make it more challenging to characterize parameter variability and achieve robust, low-power designs. The scope of this dissertation is conquering parameter variability and successfully designing efficient yet robust integrated circuit (IC) systems. Previous experiences have indicated that we need to tackle this issue at every design stage of IC chips. In this dissertation, we propose several robust techniques for accurate variability characterization and efficient performance prediction under parameter variations. At pre-silicon verification stage, a robust yield prediction scheme under limited descriptions of parameter uncertainties, a robust circuit performance prediction methodology based on importance of uncertainties, and a robust gate sizing framework by ElasticR estimation model, have been developed. These techniques provide possible solutions to achieve both prediction accuracy and computation efficiency in early design stage. At on-line validation stage, a dynamic workload balancing framework and an on-line self-tuning design methodology have been proposed for application-specific multi-core systems under variability-induced aging effects. These on-line validation techniques are beneficial to alleviate device performance degradation due to parameter variations and extend device lifetime.

Wood-frame shear wall structures are widely used for residential and commercial buildings. These buildings are lightweight, have very ductile connections and includes multiple load paths. The main objective of this dissertation is to evaluate the seismic performance of a wide range of wood-frame shear wall building designs under the influence of modeling and analysis parameter variations. The first step towards the broad objective of seismic performance evaluation is to identify the different modeling and analysis parameters that can have a potential influence in the seismic response variations. The major variations considered in this study include level of critical damping, analytical modeling of damping, hysteresis model shape variations, ground motion characteristics, level of gravity loads, and floor acceleration variations. A subset of building model designs that were originally designed for the development of FEMA P-695 methodology is adapted for the numerical evaluations and a baseline for the variations is established. To study the sensitivity of inherent damping in wood-frame shear wall structures, an extensive literature survey is completed to find the experimentally observed damping levels in these buildings. Later, nonlinear dynamic analysis is performed for the range of damping levels using different Rayleigh damping models. Ground motion scaling methods, source-to-site distance, and peak intensity levels are the selected variations in ground characteristic group. To assist with the ground motion scaling procedures, a computational toolkit is created to produce amplitude and spectrum matched ground motions for response history analysis. The particular hysteresis model CASHEW that is used for the wood-frame shear wall system has a specific load-displacement shape which is a function of the shear wall design. Three key parameters of this model are varied in a range of values that were observed during experimental tests and seismic performance responses are computed for this variations. From the performance evaluations it is observed that the seismic response is quite sensitive to several of the modeling parameter variations and analysis variations mentioned above and has a unique response based on the design of the building. The range of performance variations for the different models are outlined in the chapters included in this dissertation. / Ph. D.