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A gas turbine engine is a complex and non-linear system. Its dynamic response changes at different operating points. The exogenous inputs: atmospheric conditions and Mach number, also add disturbances and uncertainty to the dynamic. To satisfy the transient time response as well as safety requirements for its entire operating range is a challenge for control system design in the gas turbine industry. Although the recent design of engine control units includes some advanced control techniques to increase its control robustness and adaptability to the changing environment, the classic scheduling technique still plays the decisive role in determining the control values due to its better reliability under normal circumstances. Producing the schedules requires iterative experiments or simulations in all possible circumstances for obtaining the optimal engine performance. The techniques, such as scheduling method or linear control methods, are still lack of development for control of transient performance on most commercial simulation tools. Repetitive simulations are required to adjust the control values in order to obtain the optimal transient performance. In this project, a generalised model predictive controller was developed to achieve an online transient performance optimisation for the entire operating range. The optimal transient performance is produced by the controller according to the predictions of engine dynamics with consideration of constraints. The validation was conducted by the application of the control system on the simulated engines. The engines are modelled to component-level by the inter-component volume method. The results show that the model predictive controller introduced in this project is capable of providing the optimal transient time response as well as operating the engine within the safety margins under constant or varying environmental conditions. In addition, the dynamic performance can be improved by introducing additional constraints to engine parameters for the specification of smooth power transition as well as fuel economy.

In the era of big data, it is essential to implement practical security and privacy measures to ensure the lawful use of data and provide users with trust and assurance. In the dissertation, I address this issue through several key steps. Firstly, I delve into the problem of conditional secret disclosure, representing it using graphs to determine the most efficient approach for storing and disclosing secrets. Secondly, I extend the conditional disclosure of secrets problem from a single secret to multiple secrets and from a bipartite graph to an arbitrary graph. Thirdly, I remove security constraints to observe how they affect the efficiency of storage and recovery. In our final paper, I explore the secure summation problem, aiming to determine the capacity of total noise. Throughout the dissertation, I leverage information-theoretic tools to address security and privacy concerns.

In this dissertation, I focused attention on the narratives of what I defined as “these new generation rural migrant female workers.” In explaining their existence, I addressed the issue of significance in highlighting what I have termed “macro discourse”—the One-Child policy, the Household Responsibility System, and the discursive reality that they have been embedded in, along with the “micro discourses” that were represented in the discourses of the rural migrant female workers. In order to approach these new generation rural migrant female workers’ identity (re)construction in both macro and micro narratives, I engaged in a rhetorical analysis of the two policies and the social-historical discourse that they were embedded in as well as went to the field to conduct 20 in-depth interviews with members from this group of female workers.Under the guide of Nietzsche’s understanding of discourse and language as well as Foucault’s theory of discourse, I asked: 1) What and how image(s) of new generation rural migrant female workers have been constructed in the One-Child policy and the HRS? 2) How, if at all, the policies are reflected in the stories told by these new generation rural migrant female workers? 3) What, if possible, alternative understanding of the relationship between discourse and agency can be offered as rural migrant female workers talk about their way of acting/negotiating/reconstructing their identities? and 4) How might questions 2 and 3 provide a deeper conception of these new generation rural migrant female workers in this particular historical time?Nietzsche’s aesthetic language philosophy as well as Foucault’s theory of discourse offered me lenses to carefully examine the texts of the two policies and the social-historical discourse that they were ensconced within. Meanwhile, the abductive nature of grounded theory offered me insights as I was analyzing the raw materials collected from the field about what to focus on when examining the texts of the two policies and the interview data.Therefore, as I analyzed the two political texts—the Open Letter and the HRS, I answered the first research question in Chapter Four. I noted that these new generation rural migrant female workers, a group born after the launch of the OL and the HRS, were described in the OL to be “the origin of problems” for the family and for the country as they would definitely jeopardize the progress of the “Four Modernization” and retard economic development.In Chapter Five, through analyzing the 20 in-depth interviews with these new generation rural migrant female workers, I answered the second research question as I argued that the rural migrant female workers’ stories were around two themes: receiving love and care from their parents, and experiencing hardships in the discourses that they have lived in. While the love and care that they received was mainly embodied with the authenticity of parenting, the hardships that they have suffered as they grew up were mixed with issues from gender to economy, and politics to rural/urban dualism.In the last chapter, after juxtaposing Chapters Four and Five and doing a comparison study on both macro and micro narratives, I offered answers to research questions three and four. Being described as sacrifice-able individuals even before their birth, these new generation rural migrant female workers left the governmental portrayal alone and learned to be authors for their own lives. In order to do so, they focused on the construction of “a complete home,” “jia” in their words, the whole meaning of their lives. For my participants, “jia” means 1) all the reasons that they wanted promotions in their jobs, 2) the careful protection of every family member’s heart, the well planned family life, and the comfortable and cozy place, and 3) where life is. In addition, they started to narrative their own understandings of “peasant-worker.” “Peasant-worker,” the word for word translation from the Chinese phrase “nong min gong,” the term that was first brought up in 1984 was finally left in that period of history.

Mass spectrometry-based proteomics is focused on identifying the entire suite of proteins and their post-translational modifications (PTMs) in a cell, organism, or community. In particular, quantitative proteomics measures abundance changes of thousands of proteins among multiple samples and provides network-level insight into how biological systems respond to environmental perturbations. Various quantitative proteomics methods have been developed, including label-free, metabolic labeling, and isobaric chemical labeling. This dissertation starts with systematic comparison of these three methods, and shows that isobaric chemical labeling provides accurate, precise, and reproducible quantification for thousands of proteins. Based on these results, we applied this approach to characterizing the proteome of Arabidopsis seedlings treated with Strigolactones (SLs), a new class of plant hormones that modulate various developmental processes. Our study reveals that SLs regulate the expression of a range of proteins that have not been assigned to SL pathways, which provides novel targets for follow-up genetic and biochemical characterization of SL signaling. The same approach was also used to measure how elevated temperature impacts the physiology of individual microbial groups in an acid mine drainage (AMD) microbial community, and shows that related organisms differed in their abundance and functional responses to temperature. Elevated temperature repressed carbon fixation by two Leptospirillum genotypes, whereas carbon fixation was significantly up-regulated at higher temperature by a third member of this genus. Further, we developed a new proteomic approach that harnessed high-resolution mass spectrometry and supercomputing for direct identification and quantification of a broad range of PTMs from an AMD microbial community. We find that PTMs are extraordinarily diverse between different growth stages and highly divergent between closely related bacteria. The findings of this study motivate further investigation of the role of PTMs in the ecology and evolution of microbial communities. Finally, a computational approach has been developed to improve the sensitivity of phosphopeptide identification. Overall, the research presented in the dissertation not only reveals biological insights with existing quantitative proteomics methods, but also develops novel methodologies that open up new avenues in studying PTMs of proteins (e.g. PTM cross-talk).

Abstract: The electron-phonon interaction is one of the fundamental interactions in almost all condensed matter materials. In conventional superconductors, the electron-phonon interaction is the glue that attracts two electrons to one another to form a pair. A strong electron-phonon interaction leads to the concept of a polaron, which is an electron with lattice distortions around it. The small polaron is a polaron with spatial extent comparable to an interatomic dimension of the solid. Evidence for polarons has been identified in many experiments in superconductors and semiconductors. In this thesis we present exact calculations of the polaron. Specifically we have refined Trugman's method to solve the ground state of an electron-phonon coupled system in the whole parameter regime, and we also generalized this method to treat spin-orbit coupled systems. The most difficult regimes, which is the strong-coupling regime and the small phonon frequency limit, have been solved by these refinements. There are three representative kinds of electron-phonon interaction, the Holstein model, the Fr"ohlich model and the BLF-SSH model. In this thesis we have addressed the first and the third one. The second one, the Fr"ohlich model, is very similar to the Holstein model but the interaction is nonlocal. For the Holstein model we have observed the expected smooth crossover from free electrons to small polarons, while for the BLF-SSH model, we have studied the weak coupling regime with perturbation theory and derived a new analytical result for the one-dimensional problem.

This thesis presents a study on core loss calculations in rotating electrical machines. The basic concepts concerning magnetic moments, ferromagnetism, magnetic domains and magnetic hysteresis are introduced. The three-term models for alternating and rotational core losses in electrical steel sheets are presented. Several core loss measurement techniques are reviewed and an experiment is carried out to measure the total core losses in an electrical sheet steel sample under alternating and rotational magnetic fields of various frequencies and amplitudes. The coefficients in the loss models for alternating and rotational core losses are obtained through curve fitting process. The theory of electromagnetic fields is presented through the Maxwell equations and field scalar equations. A detailed review on core loss models for rotating electrical machines is presented. A rotational core loss model is adopted to calculate the core losses in a PM motor. The total core loss in the PM motor is obtained by summing the element losses using a MATLAB program. An experiment is conducted to measure the total core loss in the PM motor. The calculated total core loss in the PM motor is compared with the experimental results. The calculated total core losses are about 19% lower than the tested results. Various possible causes for this discrepancy are discussed