A proposed framework for characterising uncertainty and variability in rock mechanics and rock engineering

This thesis develops a novel understanding of the fundamental issues in characterising and propagating unpredictability in rock engineering design. This unpredictability stems from the inherent complexity and heterogeneity of fractured rock masses as engineering media. It establishes the importance of: a) recognising that unpredictability results from epistemic uncertainty (i.e. resulting from a lack of knowledge) and aleatory variability (i.e. due to inherent randomness), and; b) the means by which uncertainty and variability associated with the parameters that characterise fractured rock masses are propagated through the modelling and design process. Through a critical review of the literature, this thesis shows that in geotechnical engineering – rock mechanics and rock engineering in particular – there is a lack of recognition in the existence of epistemic uncertainty and aleatory variability, and hence inappropriate design methods are often used. To overcome this, a novel taxonomy is developed and presented that facilitates characterisation of epistemic uncertainty and aleatory variability in the context of rock mechanics and rock engineering. Using this taxonomy, a new framework is developed that gives a protocol for correctly propagating uncertainty and variability through engineering calculations. The effectiveness of the taxonomy and the framework are demonstrated through their application to simple challenge problems commonly found in rock engineering. This new taxonomy and framework will provide engineers engaged in preparing rock engineering designs an objective means of characterising unpredictability in parameters commonly used to define properties of fractured rock masses. These new tools will also provide engineers with a means of clearly understanding the true nature of unpredictability inherent in rock mechanics and rock engineering, and thus direct selection of an appropriate unpredictability model to propagate unpredictability faithfully through engineering calculations. Thus, the taxonomy and framework developed in this thesis provide practical tools to improve the safety of rock engineering designs through an improved understanding of the unpredictability concepts.Open Acces

A psychometric modeling approach to fuzzy rating data

Modeling fuzziness and imprecision in human rating data is a crucial problem in many research areas, including applied statistics, behavioral, social, and health sciences. Because of the interplay between cognitive, affective, and contextual factors, the process of answering survey questions is a complex task, which can barely be captured by standard (crisp) rating responses. Fuzzy rating scales have progressively been adopted to overcome some of the limitations of standard rating scales, including their inability to disentangle decision uncertainty from individual responses. The aim of this article is to provide a novel fuzzy scaling procedure which uses Item Response Theory trees (IRTrees) as a psychometric model for the stage-wise latent response process. In so doing, fuzziness of rating data is modeled using the overall rater's pattern of responses instead of being computed using a single-item based approach. This offers a consistent system for interpreting fuzziness in terms of individual-based decision uncertainty. A simulation study and two empirical applications are adopted to assess the characteristics of the proposed model and provide converging results about its effectiveness in modeling fuzziness and imprecision in rating data

Teachers’ Intrinsic Orientation, Self-Efficacy, Background Characteristics, and Effective Teaching:A Multilevel Moderated Mediation Modeling

Teachers’ intrinsic orientation for the profession (TIOP) refers to a compound trait derived from the meaningfulness and positive affect teachers attribute to the profession. It can be validly measured by three conceptually correlated yet empirically separable factors of autonomous motivation, enthusiasm for teaching, and enthusiasm for the subject. Grounded in the previous findings of non-significant direct relationships between TIOP and effective teaching, the present study further tested the hypothesized indirect relationships between the two constructs. To better understand the underlying relational mechanisms, the potential mediating role of self-efficacy and the moderating effects of both teacher- and school-level background factors were addressed in single- and multi-level models. A total of 239 beginning teachers from 32 Dutch secondary schools responded to the questionnaires at the beginning of the first career year. Actual teaching behaviour was observed by means of classroom observations. The results of lower-level mediation analysis confirm the mediating effect of self-efficacy on the relationship between TIOP and activating teaching behaviour at career entry. The results of single- and cross-level moderated mediation analysis show that self-efficacy significantly mediates the links between TIOP and three specific teaching behaviour domains: providing safe and stimulating learning climate, classroom management, and clarity of instruction. These effects were respectively moderated by teachers’ qualification, age, and gender. The present study makes a unique contribution to understanding the importance of TIOP for beginning teachers’ well-being and effective teaching, providing insights for both teacher educators and mentors

Rationalizing Noneconomic Damages: A Health-Utilities Approach

Studdert et al examine why making compensation of noneconomic damages in personal-injury litigation more rational and predictable is socially valuable. Noneconomic-damages schedules as an alternative to caps are discussed, several potential approaches to construction of schedules are reviewed, and the use of a health-utilities approach as the most promising model is argued. An empirical analysis that combines health-utilities data created in a previous study with original empirical work is used to demonstrate how key steps in construction of a health-utilities-based schedule for noneconomic damages might proceed

The Assessment of Motivation in the Learning of EFL at University Level: Validation of the English Language Learning Motivation Scale (ELLMS) at Four Spanish State Universities

Successful performance in the study of English as a Foreign Language is known to be subject to psychological constructs such as type of motivation, degree of self-regulated learning and levels of anxiety and burnout, or academic fatigue. The present study—conducted at the University of Valladolid Segovia Campus—served a double purpose. Firstly, it was used to validate the English Language Learner Motivation Scale (ELLMS) in a sample of university students who were studying this language but whose degrees were in subjects other than English Language or Linguistics. Secondly, it demonstrated that intrinsic motivation is associated with less anxiety and greater self-regulation and self-efficacy in the English language learning process. To both ends, we created a 94-question online survey which blended items from four other instruments measuring levels of anxiety, self-regulation and burnout. This questionnaire, delivered to 214 students from four different Spanish universities, produced interesting results. To begin with, it confirmed the first objective of the study and validated ELLMS as a viable instrument to measure motivation in this population, as well as confirming the presence of the three psychological factors envisaged in the original theoretical proposal and which the reader can find defined and analysed in depth in this paper: intrinsic motivation, external regulation and introjected regulation. The variable introjected regulation was negatively correlated with anxiety but positively with reported levels of burnout informed. With regard to external regulation, the results were not conclusive. This paper considers both the educational implications of these results and the impact that these variables have on the learning of English as a Foreign Language

Exaggerating good governance: Regime type and score inflation among executive survey informants

Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/146313/1/gove12330_am.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/146313/2/gove12330.pd

The Relationship Between Organizational Culture, Intrinsic Motivation, And Employee Performance: A Systematic Review And Meta-Analysis

The purpose of this study was to explore the relationship between specific organizational cultural factors (autonomy and meaningful work), intrinsic motivation, and employee performance through a systematic review and meta-analysis. Three separate studies were performed, one for each predictor variable: autonomy, meaningful work, and organizational culture/climate. The meta-analyses included only studies that contained correlations for all three variables and were set in a business environment. The first study concluded that autonomy is a predictor of performance; this relationship is partially mediated through intrinsic motivation. The second study concluded that meaningful work is a predictor of performance. The third study was conducted for comparative purposes only and no solid conclusions could be drawn from this study. The data sets for studies two and three were small, which led to some problematic results and the use of caution when interpreting them. The overall study helped to provide another method for practitioners to assist organizations in increasing intrinsic motivation and performance of employees by having organizational cultures that support the autonomy of employees. This study uncovered several additional suggestions for further research, including more empirical research into the main variables of the study

Uncertainty in Engineering

This open access book provides an introduction to uncertainty quantification in engineering. Starting with preliminaries on Bayesian statistics and Monte Carlo methods, followed by material on imprecise probabilities, it then focuses on reliability theory and simulation methods for complex systems. The final two chapters discuss various aspects of aerospace engineering, considering stochastic model updating from an imprecise Bayesian perspective, and uncertainty quantification for aerospace flight modelling. Written by experts in the subject, and based on lectures given at the Second Training School of the European Research and Training Network UTOPIAE (Uncertainty Treatment and Optimization in Aerospace Engineering), which took place at Durham University (United Kingdom) from 2 to 6 July 2018, the book offers an essential resource for students as well as scientists and practitioners