Micrometre-scale plasticity size effects in metals and ceramics: theory and experiment.

PhDThis thesis comprises studies of size effects in the plasticity of metals and ceramics at length scales of the order of micrometres and includes both experimental work and theoretical development. Experimental results are presented for foil flexure (nickel and copper)and nanoindentation (ceramics and hard metals).These studies were conducted because existing data does not cover a range broad enough or with sufficient precision to test various theories. With the developed bending technique more accurate data is obtained covering a wide range of strain, especially around the key region of the elastic-plastic transition. Moreover, the interaction between grain and thickness size effect is successfully studied by varying the ratio of grain size over thickness of the foils. After carefully calibrating the indenters, the macroscopic indentation yield strength for ceramics and high strength metals is determined in a direct way by using spherical nanoindentation. The magnitude of size effect is significantly different between metals and ceramics. By comparing the Berkovich and spherical indentation size effect, the results implies that the contact size, a, is the most fundamental length scale in the indentation size effect, independent of the indenter shape. The indentation strength is found to be inversely scaled with the square root of a. The slip-distance theory (based on (Conrad et al, 1967)) with an effective length scale reconciling intrinsic and extrinsic size effects appears able to account for the size effects in all contexts, without requiring strain gradient plasticity theory or an implicit characteristic length

Fusing Continuous-valued Medical Labels using a Bayesian Model

With the rapid increase in volume of time series medical data available through wearable devices, there is a need to employ automated algorithms to label data. Examples of labels include interventions, changes in activity (e.g. sleep) and changes in physiology (e.g. arrhythmias). However, automated algorithms tend to be unreliable resulting in lower quality care. Expert annotations are scarce, expensive, and prone to significant inter- and intra-observer variance. To address these problems, a Bayesian Continuous-valued Label Aggregator(BCLA) is proposed to provide a reliable estimation of label aggregation while accurately infer the precision and bias of each algorithm. The BCLA was applied to QT interval (pro-arrhythmic indicator) estimation from the electrocardiogram using labels from the 2006 PhysioNet/Computing in Cardiology Challenge database. It was compared to the mean, median, and a previously proposed Expectation Maximization (EM) label aggregation approaches. While accurately predicting each labelling algorithm's bias and precision, the root-mean-square error of the BCLA was 11.78$\pm$0.63ms, significantly outperforming the best Challenge entry (15.37$\pm$2.13ms) as well as the EM, mean, and median voting strategies (14.76$\pm$0.52ms, 17.61$\pm$0.55ms, and 14.43$\pm$0.57ms respectively with $p<0.0001$)

The Performance of Canadian Pooled Equity Funds

In this paper, we evaluate and rank the performance of 65 Canadian Equity Pooled Funds. We adopt traditional performance measures to evaluate pooled fund managers’ performances from January 1999 to December 2008. We employ the geometric mean as a reward measure, standard deviation and beta coefficient as risk measures, and Capital Asset Pricing Model (CAPM) risk-adjusted measures that include Jensen’s (1968) alpha, the Treynor (1965) ratio, the Sharpe (1966) ratio, and Modigliani and Modigliani’s (1997) M-Squared. Treynor-Mazuy (1966) and Henriksson-Merton (1981) are used to measure market-timing. According to our results, thirty-five percent of 65 Canadian Equity Pooled Funds managers have abnormal returns in terms of Jensen’s (1968) alpha. Only eight pooled fund managers have market-timing ability. None of 65 pooled fund managers has both selectivity and market-timing ability at the same time

Reliability Enhancement of Predictive Computational Models in Hydroscience and Engineering

Source: ICHE Conference Archive - https://mdi-de.baw.de/icheArchiv

Impacts of Reduced Inequalities on Quality Education:Examining the Relationship between Regional Sustainability and Higher Education

Although the United Nations&rsquo; Sustainable Development Goals (SDGs) advocate, through SDG 4 and SDG 10, equitable quality education and the reduction of inequalities within and between countries, respectively, few studies have examined how inequalities in regional sustainability influence higher education. Therefore, this study aims to examine the relationship between regional sustainability and higher education in China using fixed-effects panel modelling. A systematic force framework showing how regional sustainability drives higher education was constructed from economic, social, and environmental perspectives, and the endogeneity in the process of how regional sustainability affects higher education was explored by introducing one-year lagged values as instrumental variables. Our results show that regional sustainability has a significant impact on higher educational attainment in China, with differing effects in the eastern, central, and western regions, respectively. In central China, economic sustainability plays a significant positive role in higher educational attainment; in the western region, economic and social sustainability have stronger positive effects, while environmental sustainability has significantly negative effects. In terms of policy implications, our findings can be used to support regional development policies to promote regional higher education