Model reduction is motivated by the fact that complex process models may pre- vent the application of model-based process control. While extensive research on model reduction has been done in the past few decades, model reduction of systems exhibiting two-time scale behavior as well as parametric uncertainty has received little attention to date. This work addresses these types of problems in detail. Systems with two-time scale behavior can be described by differential-algebraic equations (DAEs). A new technique based on projections and system identification is presented for reducing this type of system. This method reduces the order of the differential equations as well as the number and complexity of the algebraic equations. Additionally, the algebraic equations of the resulting system can be replaced by an explicit expression for the algebraic variables such as a feed-forward neural network or partial least squares. This last property is important insofar as the reduced model does not require a DAE solver for its solution, but system trajectories can instead be computed with regular ordinary differential equation (ODE) solvers. For systems with uncertain parameters, two types of problems are investigated, including parameter reduction and parameter dependent model reduction. The pa- rameter reduction problem is motivated by the fact that a large number of parameters exist in process models while some of them contribute little to a system's input-output behavior. This portion of the work presents three novel methodologies which include (1) parameter reduction where the contribution is measured by Hankel singular val- ues, (2) reduction of the parameter space via singular value decomposition, and (3) a combination of these two techniques. Parameter dependent model reduction investigates how to incorporate the influ- ence of parameters in the procedure of conventional model reductions. An approach augmenting the input vector to include the parameters are developed to solve this problem. Finally, a nonlinear model predictive control scheme is developed in which the reduced models are used for the controller. Examples are investigated to illustrate these techniques. The results show that excellent performance can be obtained for the reduced models.

Obesity is a significant issue for health care systems over the world, including Taiwan. In particular, obesity is a chronic disease with monumental public health implications, which associated with metabolic syndrome, and weight reduction was suggested to first line treatment. The objective of the study is to explore the efficacy (including of body composition and blood biochemical lab data) after ear acupuncture combined therapy with diet and physical activity . Participants and Setting: 369 people which belong to overweight ( BMI¡Ù24 kg/m2) and obesity (BMI¡Ù 27kg/m2 ) and a 12-week body weight control trial (purposive sampling trial) from July to December 2006. Intervention: Ear acupuncture was treated weekly for 12 weeks and participants need to keep their regular daily diet and physical activity. Our objective is to explore the efficacy (including of body composition and blood biochemical laboratory data) after 12-week body weight control trial. Results: Participants and Setting: 369 people and a 12-week body weight control trial from July to December 2006, the average of body weight for participants reduction 13.9 ¡Ó 5.0 Kg (p<0.001). BMI for participants reduction 5.3 ¡Ó 1.8 (p<0.001). Body fat for participants reduction 8.8 ¡Ó 2.5 % (p<0.001). Waist circimference for participants reduction 12.8 ¡Ó 5.8 cm (p<0.001). Waist to hip ratio for participants reduction 0.03 ¡Ó0.04 (p<0.001).Fasting sugar for participants reduction 5.0 ¡Ó 12.0 mg/dl (p<0.001). Total cholesterol for participants reduction 30.1 ¡Ó 26.2 mg/dl (p<0.001). LDL-cholesterol for participants reduction 31.2 ¡Ó 24.8 mg/dl (p<0.001). HDL-cholesterol for participants increasing 7.4 ¡Ó 7.8 mg/dl (p<0.001). Triglyceride for participants reduction 24.5 ¡Ó 52.1 mg/dl (p<0.001) GPT for participants reduction 16.1 ¡Ó 24.3 mg/dl (p<0.001). Uric acid for participants reduction 1.0 ¡Ó 5.5 mg/dl (p<0.001). But hemoglobin for participants reduction 0.5 ¡Ó 0.6 g/dl (p<0.001). Conclusion: These findings indicate that 12-week body weight control trial can be effective in treating obesity.

Over the past three decades or so, metaheuristics has been one of the most important and successful techniques for finding the true or near optimal solution of complex problems. Instead of systematically enumerating and checking all the candidate solutions that would take forever to accomplish, it works by guessing the right directions for finding the true or near optimal solution so that the space searched, and thus the time required, can be significantly reduced. However, our observation shows that most of the metaheuristic algorithms face a common problem. That is, because of the requirements of convergence, they all involve a lot of redundant computations during the convergence process. In this thesis, we present a simple but efficient algorithm for solving the problem, called the Pattern Reduction algorithm (or PR for short). The proposed algorithm is motivated by the observation that some of the sub-solutions that are repeatedly computed during the convergence process can be considered as part of the final solutions and thus can be first compressed and then removed to eliminate the redundant computations at the later iterations during the convergence process. Since PR is basically a concept that is not limited to any particular metaheuristic algorithm, we present several methods derived from the concept for eliminating the duplicate computations of metaheuristics in the thesis. Although our simulation results show that they all perform well in terms of the computation time reduced, they are not perfect in terms of the quality of the end results because in some cases they will cause a small loss of the quality. For this reason, rather than how much computation time the proposed algorithm can reduce, our ultimate goal is to eliminate all the redundant computations while at the same time preserving or even enhancing the quality of the end result of metaheuristics alone.

Thesis (Ph. D.)--Lehigh University, 2002. / Includes vita. Includes bibliographical references (leaves 94-97).

Thesis (M. Phil.)--University of Hong Kong, 1984.

Thesis (Ph. D.)--University of Hong Kong, 1988.

This Master’s report presents the research leading to the development of a low power Wireless Sensor Network (WSN) and a discussion of an implementation of the WSN. This report assesses the power reduction techniques further by reviewing their influences upon functionality, throughput, latency, and data reliability. The software techniques were implemented on evaluation boards and actual performance gains were observed. Furthermore, the report provides insight into the selection of the processor, wireless protocol, and WSN architecture by comparing other options in regards to the power reduction, functionality, and data reliability. The architecture of the WSN consists of four sensor nodes, and a backbone router connected to a PC. The sensor nodes contain an application processor and a radio processor. The application processor is a Texas Instruments MSP430F5438 which is located on an MSP-EXP430F5438 evaluation board. The radio processor is a NIVIS Versa Node 210 that is located on a VS210 development board. The wireless protocol investigated is the ISA100.11a. / text

Gold has been considered catalytically inert due to its resistance to oxidation and corrosion. However, decades ago, it was discovered that gold nano-particles (<5nm) on metal oxides demonstrate superior chemical activity towards many reactions. These seminal findings spurred considerable interest in investigations of the mechanistic details of oxidative reactions on gold-based catalysts. However, the active site and structure of supported Au nanoclusters as well as the active oxygen species remains elusive. Achieving high selectivity toward partial oxidation products also remains a challenge. In this dissertation, an oxygen-covered Au(111) crystal under ultra vacuum conditions was used as a model system to gain insights into oxidative reactions in gold-based catalysis. I have been able to demonstrate that (i) surface-bound oxygen atoms are metastable at low temperature; (ii) the oxygen atoms participate in surface reactions as a Brønsted base or a nucleophilic base; and (iii) the acid-base reactions that have been observed on silver and copper may also occur on gold. Low temperature CO oxidation and the associated mechanistic aspects are investigated. CO reacts with hydroxyls formed from water-oxygen interactions to produce CO₂ on Au(111) populated with atomic oxygen at low temperatures. Directing an ¹⁶O beam toward C¹⁸O₂ pre-adsorbed Au(111), the formation of carbonate is significantly enhanced. This reaction is suggested to follow a hot-precursor-mediated mechanism. The identification of reaction pathways in oxidation of N-containing molecules such as ammonia and propylamine is presented. Abstraction of hydrogen from ammonia or propylamine by O atoms is the initial step in the surface decomposition of NHx (or RNHx-1) on Au(111). Atomic oxygen or hydroxyl-assisted dehydrogenation steps have lower barriers than the recombination steps under relevant conditions. 100% selectivity of N₂ or propionitrile can be obtained if the oxygen coverage is below the stoichiometric value. The surface oxidative chemistry of alcohols on Au(111) is also investigated. Except for methanol that is fully oxidized, alcohols initially undergo O-H bond cleavage (producing alcoxides) followed by selective β-C-H bond activation to form aldehydes or ketones. This finding reveals that the interaction of Au with the metal oxide support might not be essential to facilitate the reactions if active oxygen species are readily present, particularly at low temperatures. / text

published_or_final_version / Chinese Medicine / Doctoral / Doctor of Philosophy

This research investigated the mechanism, kinetics, and feasibility of chlorinated aliphatic compounds inactivation by electrochemical reduction using nickel and iron electrodes. Reactions of trichloroethylene (TCE) and tetrachloroethylene (PCE) with zerovalent iron were investigated to determine the role of atomic hydrogen in their reductive dechlorination using Tafel analysis and electrochemical impedance spectroscopy (EIS). Comparison of iron corrosion rates with those for TCE reaction showed that TCE reduction occurred almost exclusively via atomic hydrogen at low pH values and via atomic hydrogen and direct electron transfer at neutral pH values. In contrast, reduction of PCE occurred primarily via direct electron transfer at both low and neutral pH values. The EIS data showed that all the rate limitations for TCE and PCE dechlorination occurred during the transfer of the first two electrons. Carbon tetrachloride (CT) reductive dechlorination was studied at a nickel rotating disk electrode using chronoampermetry (CA) and EIS. Only trace levels of methylene chloride and chloromethane were produced, indicating that sequential hydrogenolysis was not the predominant pathway for methane production. EIS showed that the ratelimiting step for CT reduction was the transfer of the first electron to a physically adsorbed CT molecule. The feasibility of an electrochemical reductive dechlorination method for removing CT from potable water was carried out in a flow-through reactor using bare and polymer coated porous nickel electrodes. Destruction of half-life values for CT with the bare nickel electrode ranged from 3.5 to 5.8 minutes for electrode potentials ranging from -652 to -852 mV with respect to the standard hydrogen electrode (SHE). Faradic current efficiencies could be increased by 100 to 360% by coating the electrode with a silicone polymer. This research also investigated electrochemical oxidation of triclosan, a biocidal agent, using Ebonex® and boron-doped diamond (BDD) film anodes. Product analysis showed that breaking the ether linkage was easier than opening the aromatic ring. Microtox® testing indicated that residual triclosan accounted for nearly all the toxicity in the treated water, despite the fact that chlorinated byproduct concentrations were significantly higher than those of triclosan itself.