Optimal Uncertainty Quantification

We propose a rigorous framework for Uncertainty Quantification (UQ) in which the UQ objectives and the assumptions/information set are brought to the forefront. This framework, which we call \emph{Optimal Uncertainty Quantification} (OUQ), is based on the observation that, given a set of assumptions and information about the problem, there exist optimal bounds on uncertainties: these are obtained as values of well-defined optimization problems corresponding to extremizing probabilities of failure, or of deviations, subject to the constraints imposed by the scenarios compatible with the assumptions and information. In particular, this framework does not implicitly impose inappropriate assumptions, nor does it repudiate relevant information. Although OUQ optimization problems are extremely large, we show that under general conditions they have finite-dimensional reductions. As an application, we develop \emph{Optimal Concentration Inequalities} (OCI) of Hoeffding and McDiarmid type. Surprisingly, these results show that uncertainties in input parameters, which propagate to output uncertainties in the classical sensitivity analysis paradigm, may fail to do so if the transfer functions (or probability distributions) are imperfectly known. We show how, for hierarchical structures, this phenomenon may lead to the non-propagation of uncertainties or information across scales. In addition, a general algorithmic framework is developed for OUQ and is tested on the Caltech surrogate model for hypervelocity impact and on the seismic safety assessment of truss structures, suggesting the feasibility of the framework for important complex systems. The introduction of this paper provides both an overview of the paper and a self-contained mini-tutorial about basic concepts and issues of UQ.Comment: 90 pages. Accepted for publication in SIAM Review (Expository Research Papers). See SIAM Review for higher quality figure

Time reclaimed: temporality and the experience of meaningful work

The importance of meaningful work has been identified in scholarly writings across a range of disciplines. However, empirical studies remain sparse and the potential relevance of the concept of temporality, hitherto somewhat neglected even in wider sociological studies of organizations, has not been considered in terms of the light that it can shed on the experience of work as meaningful. These two disparate bodies of thought are brought together to generate new accounts of work meaningfulness through the lens of temporality. Findings from a qualitative study of workers in three occupations with ostensibly distinct temporal landscapes are reported. All jobs had the potential to be both meaningful and meaningless; meaningfulness arose episodically through work experiences that were shared, autonomous and temporally complex. Schutz’s notion of the ‘vivid present’ emerged as relevant to understanding how work is rendered meaningful within an individual’s personal and social system of relevances

Club does not imply the existence of a Suslin tree

We prove that club does not imply the existence of a Suslin tree, so answering a question of I. Juhasz

Human Resources and the Resource Based View of the Firm

The resource-based view (RBV) of the firm has influenced the field of strategic human resource management (SHRM) in a number of ways. This paper explores the impact of the RBV on the theoretical and empirical development of SHRM. It explores how the fields of strategy and SHRM are beginning to converge around a number of issues, and proposes a number of implications of this convergence

Placing relationships in the foreground: the role of workplace friendships in engagement

We explore the role of workplace friendships as a lens for understanding the emotional element and relational context for personal engagement (Kahn, 1990). The review of engagement theory differentiates personal engagement, recognising the role emotions play in enabling individuals’ ‘preferred selves’. Workplace relationships and friendship provide a conceptual discussion of individuals in social and workplace roles in engagement, drawing on friendship, emotion, attachment theories, particularly Kahn’s work. A case study drawn from recent research illustrates our discussion before concluding with ideas for the development of a future research agenda in answer to recent calls for work on the social context of engagement

A realist evaluation of the management of a well- performing regional hospital in Ghana

<p>Abstract</p> <p>Background</p> <p>Realist evaluation offers an interesting approach to evaluation of interventions in complex settings, but has been little applied in health care. We report on a realist case study of a well performing hospital in Ghana and show how such a realist evaluation design can help to overcome the limited external validity of a traditional case study.</p> <p>Methods</p> <p>We developed a realist evaluation framework for hypothesis formulation, data collection, data analysis and synthesis of the findings. Focusing on the role of human resource management in hospital performance, we formulated our hypothesis around the high commitment management concept. Mixed methods were used in data collection, including individual and group interviews, observations and document reviews.</p> <p>Results</p> <p>We found that the human resource management approach (the actual intervention) included induction of new staff, training and personal development, good communication and information sharing, and decentralised decision-making. We identified 3 additional practices: ensuring optimal physical working conditions, access to top managers and managers' involvement on the work floor. Teamwork, recognition and trust emerged as key elements of the organisational climate. Interviewees reported high levels of organisational commitment. The analysis unearthed perceived organisational support and reciprocity as underlying mechanisms that link the management practices with commitment.</p> <p>Methodologically, we found that realist evaluation can be fruitfully used to develop detailed case studies that analyse how management interventions work and in which conditions. Analysing the links between intervention, mechanism and outcome increases the explaining power, while identification of essential context elements improves the usefulness of the findings for decision-makers in other settings (external validity). We also identified a number of practical difficulties and priorities for further methodological development.</p> <p>Conclusion</p> <p>This case suggests that a well-balanced HRM bundle can stimulate organisational commitment of health workers. Such practices can be implemented even with narrow decision spaces. Realist evaluation provides an appropriate approach to increase the usefulness of case studies to managers and policymakers.</p

Job insecurity, employee anxiety, and commitment: The moderating role of collective trust in management

This article examines the moderating effect of collective trust in management on the relation between job insecurity (both objective and subjective) and employee outcomes (work-related anxiety and organisational commitment). This is contextualised in the modern British workplace which has seen increased employment insecurity and widespread cynicism. We use matched employer-employee data extracted from the British Workplace Employment Relations Survey (WERS) 2011, which includes over 16,000 employees from more than 1100 organisations. The multilevel analyses confirm that objective job insecurity (loss of important elements of a job such as cuts in pay, overtime, training, and working hours) are significantly correlated with high levels of work-related anxiety and lower levels of organisational commitment. These correlations are partially mediated by subjective job insecurity (perception of possible job loss). More importantly, collective trust in management (a consensus of management being reliable, honest and fair) significantly attenuates the negative impact of objective job insecurity on organisational commitment, and reduces the impact of subjective job insecurity on work-related anxiety. Theoretical and practical implications and limitations of these effects are discussed