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Fault analysis based on high-resolution data acquisition is growing in use as it offers a more complete picture of faults, which provides an opportunity to deal with failures more effectively. However, with increasing volumes of data being collected, it becomes impossible for engineers to interpret every fault instance. To solve this, this thesis proposes novel power network fault detection and diagnosis methods applied to continuous high-frequency Power Quality (PQ) data. These novel methods deliver online anomaly segmentation, fault classification, and automatic fault labelling. The work addresses the need for increasing levels of situational awareness in distribution networks and its corresponding data-related challenges. The combination of these contributions can achieve automatic extraction of information from operational PQ data without excessive manual effort. This research uses simulated cases and operational data to validate the effectiveness of the contributions. The significance of this research is that it extracts critical information from continuous PQ data streams and automatically interprets the segmented signals, which reduces the demand for expert interpretation. In addition, it can operate through intensive monitoring at a single point on the network, which enhances the observability of the distribution network without installing excessive amounts of sensors.

Abstract: Metabolic syndrome, a major public health challenge, is identified as a collection of impaired glucose metabolism, central obesity, elevated blood pressure and dyslipidemia. It is estimated that approximately 25% of the world’s population has metabolic syndrome. Insulin resistance, a pathologic state in which target cells fail to respond to normal levels of circulating insulin, is a common feature of most types of metabolic disorders, including type 2 diabetes. Food protein derived bioactive peptides have attracted extensive attention during the past decades and have great potential for the development of functional foods and/or nutraceuticals for the management and prevention of metabolic syndrome. IRW (Ile-Arg-Trp) was initially identified as an inhibitor of angiotensin converting enzyme (ACE) from egg white protein ovotransferrin. For the past decade, our research group found various activities of IRW. However, the structural requirements of IRW especially which amino acid of IRW is the most important is unknown. Two dipeptides, IR and RW, three amino acids, I, R and W, as well as eight tripeptides, ARW, IAW, IRA, IWR, RIW, RWI, WIR, and WRI were designed to understand the structure and activity relationship of IRW. Tumour necrosis factor-α (TNF-α) induced insulin resistant skeletal muscle L6 cell was applied for the study, and IRW was used as the positive control. Among the tested peptides and amino acids, only IRA and IR showed comparable effects as that of IRW: enhanced glucose uptake, improvement in the impaired insulin signaling pathway and increased glucose transporter protein 4 (GLUT4) translocation in TNF-α treated L6 myotubes. This result demonstrated that C-terminal W is not essential to the activity of IRW. Next, we studied the bioactivity of IR and IRA in a high-fat diet (HFD) induced insulin resistant mouse model, IRW was included as a positive control. Both IRA and IR improved fasting and decreased fasting insulin in HFD induced glucose intolerance mice. While both IRA and IR increased Akt phosphorylation and peroxisome proliferator-activated receptor gamma (PPARγ) abundance in skeletal muscle, only IRA significantly enhanced phosphorylation of 5’ AMP-activated protein kinase (AMPK). Our study also showed a reduced local renin angiotensin system (RAS) activity by peptide treatment, but only IR increased mas-receptor (Mas-R) level in skeletal muscle. Our animal study supports the cell experiment’s conclusion that C-terminal residue W of IRW is not essential for the activity of IRW, but the mechanisms of action by these two peptides are different. This thesis supports that the C-terminal residue, W, of IRW is dispensable for regulating the activity of IRW. This result help us to understand the structure and activity relationship of IRW.

Nanoporous (np) materials with pore size below 100 nano-meters exist naturally in biological and mineral structures, and synthetic np materials have been used industrially for centuries. Np materials have attracted significant research interest in recent decades, as the development of new characterization techniques and nanotechnology allow the observation and design of np materials at a new level. This study focuses on two np materials: nanoporous silicon (np-Si) and nanoporous palladium (np-Pd). Silicon (Si), because of its high capacity to store lithium (Li), is increasingly becoming an attractive candidate as anode material for Li ion batteries (LIB). One significant problem with using Si as an anode is the large strain that accompanies charge-discharge cycling, due to swelling of the Si during Li insertion and deinsertion. Np-Si offers a large amount of free volume for Li absorption, which could allow the anode material to swell without cracking. A new method to fabricate thin films of high-purity (100% Si content) np-Si, which is promising as an anode material for LIB, is demonstrated and discussed in this study. Microstructural characterization, chemical analysis, battery performance testing and mechanical behavior of thin film np-Si are discussed here. Palladium (Pd) is considered an ideal and reliable hydrogen sensor and storage material, due to its fast response and selectivity for hydrogen gas. This research not only demonstrates a method to fabricate np-Pd thin films, but also proposes a method to fabricate bulk np-Pd. The uniformly crack-free and sponge-like np-Pd thin film provides high sensitivity to low concentrations of H2, showing promise as a hydrogen sensor material. Stress changes during hydrogenation/dehydrogenation were measured using wafer curvature. For bulk np-Pd, ultra-fine pore sizes were achieved by electrochemically dealloying bulk PdNi alloy. Mechanical behavior of bulk np-Pd was studied using in-situ transmission electron microscopy (TEM). Scanning electron microscopy (SEM) and x-ray diffraction were also used to characterize the structure and morphology of np-Pd. This doctoral research has involved the optimization of fabrication conditions and investigations of microstructural evolution during processing, yielding an improved understanding of the properties, mechanical behavior and potential applications of np-Si and np-Pd.

This paper shows how accounting conservatism affects the efficiency of debt contracting when the optimal debt contract allows parties to renegotiate. In my model allowing for renegotiation is optimal because both borrowers and lenders have access to non-contractible “soft information”, in addition to the more objective accounting information. I show that conservative accounting can increase the efficiency of debt contracting when the other soft information is also sufficiently conservative (to be defined in the paper). However, when the soft information is aggressive, conservative accounting is detrimental to the efficiency of debt contracting. Thus, whether more conservative financial reporting is good for debt contracting depends on the interaction between the informational characteristics of the accounting system and other available information. Interestingly, the result that the informational characteristics of the accounting system should be the same as those of the soft information stands in contrast to the conjecture proposed by many studies -- that accounting needs to be conservative because other information, such as that offered by management, is opportunistically aggressive.