Model Predictive Control of a Nonlinear Aeroelastic System Using Volterra Series Representations

The purpose of this study is to investigate the potential effectiveness of using a Volterra-based Model Predictive Control strategy to control a nonlinear aeroelastic system. Model Predictive Control (MPC), also known as Receding Horizon Control (RHC), entails computing optimal control inputs over a finite time horizon, applying a portion of the computed optimal control sequence, and then repeating the process over the next time horizon. The Volterra series provides input-output models of a dynamical system in terms of a series of integral operators of increasing order, where the first-order Volterra operator models the linear dynamics and the higher-order operators model the nonlinear dynamics. In this thesis, Volterra-based Model Predictive Control is applied to simulated linear and nonlinear pitch-plunge aeroelastic systems. A linear MPC controller based on a first-order Volterra model is used to control the linear aeroelastic system, and the results are compared to those obtained using a standard LQR controller and a LQR-based MPC strategy. The controller is implemented for regulator and tracking cases for a free-stream velocity of 6 m/s, a condition for which the open-loop linear system is stable, and a free-stream velocity of 12.5 m/s, which corresponds to an unstable flutter condition. Nonlinear MPC controllers, using second- and third-order Volterra models, are then used to control the nonlinear aeroelastic system for regulator and tracking cases at the stable flight condition. The stability and performance of the linear and nonlinear Volterra-based MPC strategies are discussed, and a detailed analysis of the effect of different parameters such as the optimization horizon, control horizon and control discretization, is provided. The results show that the linear MPC controller is able to successfully track a reference input for the stable condition and stabilizes the system at the unstable flutter condition. It is also shown that the incorporation of the second- and third-order Volterra kernels in the nonlinear MPC controller provides superior performance on the nonlinear aeroelastic system compared to the results obtained using only a linear model

The genre, composition and hermeneutics of the Epistle of James

The present thesis aims to determine the genre, the compositional structure and the hermeneutics found in the letter of James. It is divided into five parts. Part one first examines the various proposals for the genre of James. James is found to be a "counter cultural" wisdom instruction challenging the hearers' worldview and to reorient them to the values acceptable to God. Part two examines the previous attempts to uncover the structure of James. Here I adopt discourse analysis, paying special attention to the formal features of wisdom instruction. Part three explores the importance of law and wisdom to the understanding of the hermeneutics of James. James is using the love command as hermeneutical principle in understanding the Torah and is comparable to that in Matthew. Wisdom, a gift from God, is involved in the "how" of the important hermeneutical task of applying and keeping the law in one's particular situation. It also manifests itself in one's keeping of the law. Part four investigates the meaning of the call to perfection and the predicament of doubleness in relation to law and wisdom in the context of early Jewish and Christian thought. By adhering to the implanted word, doing what this word/law requires, Christians will be on the way to perfection and to life/salvation. Part five looks at the importance of eschatology which provides the underlying framework for the hermeneutics found in James. In conclusion, James is seen as a wisdom instruction which adapts the teaching of Jesus, making it relevant to his readers. Our author exhorts his readers, the messianically renewed people of God, redeemed by the word of truth, to move along the way of perfection in obedience to the law, waiting for the coming of the Lord at the end of this age

Stromal Tumor Microenvironment in Chronic Lymphocytic Leukemia: Regulation of Leukemic Progression

Chronic Lymphocytic Leukemia (CLL), the most prevalent adult leukemia in western countries, which is highly heterogeneous with a very variable clinical outcome. Emerging evidence indicates that the stromal tumor microenvironment (STME) and stromal associated genes (SAG) play important roles in the pathogenesis and progression of CLL. However, the precise mechanisms by which STME and SAG are involved in this process remain unknown. In an attempt to explore the role of STME in this process, we examined the expression levels of stromal associated genes using gene expression profiling (GEP) of CLL cells from lymph nodes (LN) (n=15), bone marrow (BM) (n=18), and peripheral blood (PB) (n=20). Interestingly, LUM, MMP9, MYLK, ITGA9, CAV1, CAV2, FBN1, PARVA, CALD1, ITGB5 and EHD2 were found to be overexpressed while ITGB2, DLC1 and ITGA6 were under expressed in LN-CLL compared to BM-CLL and PB-CLL. This is suggestive of a role for LN-mediated TME in CLL cell survival/progression. Among these genes, expression of MYLK, CAV1 and CAV2 correlated with clinical outcome as determined by time to first treatment. Together, our studies show that members of the stromal signature, particularly in the CLL cells from lymph nodes, regulate CLL cell survival and proliferation and thus leukemic progression

Recursive properties of Dirac and Metriplectic Dirac brackets with Applications

In this article, we prove that Dirac brackets for Hamiltonian and non-Hamiltonian constrained systems can be derived recursively. We then study the applicability of that formulation in analysis of some interesting physical models. Particular attention is paid to the feasibility of implementation code for Dirac brackets in Computer Algebra System and analytical techniques for inversion of triangular matrices.Comment: 29 pages, Latex. Extended version of the article in Physica

The process of complex mental arithmetic : a comparison between novices and piano players

The mental representation and processes involved in complex mental arithmetic, and the effect of music training on mathematical processing are still unclear in the literature. There were two experiments in this thesis. In experiment 1, we investigated how complex mental arithmetic involving double-digit numbers are represented and processed mentally with a dual-task paradigm. Furthermore, to better understand how the processing pattern due to music training can potentially enhance one’s mathematical processing, we recruited a group of piano players and examined their differences compared with novices in experiment 2. In the first experiment, it was found that participants in general engaged more visuospatial processing in both double-digit addition and multiplication. There was a shift in processing pattern in multiplication, where the reliance on verbal processing in single-digit multiplication has been shifted to visuospatial processing in double-digit multiplication. Participants may use visuospatial processing to hold the intermediate solutions visually and to approximate numerosity. In the second experiment, it was found that piano players performed better in calculation tasks (especially in addition) under full attention. The superior performance among piano players may be related to their processing pattern as revealed by the dual task condition. Specifically, unlike novices, who employed more visuospatial than verbal processing to carry out complex arithmetic, piano players did not show such strong preference. The ability to not rely on a particular kind of processing may allow piano players to have greater flexibility in engaging either verbal or visuospatial processing in doing complex arithmetic. This is consistent with previous studies showing musicians having more bilateral connectivity compared to novices. This suggests that the effect of music training can be transferred to mathematical processing.published_or_final_versionPsychologyMasterMaster of Philosoph

Development of genotypic resistance testing for integrase inhibitor

published_or_final_versionMicrobiologyMasterMaster of Medical Science