BayesProject: Fast computation of a projection direction for multivariate changepoint detection

Statistics and Computing - This article focuses on the challenging problem of efficiently detecting changes in mean within multivariate data sequences. Multivariate changepoints can be detected by...     

Bourdieu's distinction between philosophical and sociological approaches to Science Studies*

Sociological inquiry into the natural sciences has shown that they are contingent, social constructions. However, Science Studies research has been obstructed by epistemological conflicts about the nature of science and theoretical perspectives upon studying it. Bourdieu's sociology of science is under‐utilized in this field, as he addresses these obstructions and offers a way forward. Bourdieu argues that researchers have failed to distinguish between sociological and philosophical approaches in social science, thus committing the ‘scholastic fallacy’. In conjunction with this fallacy, the logic of the Science Studies field produces a tendency towards disciplinary confusion, philosophical radicalization, and crisis. These patterns were expressed in the ‘science wars’. The field has followed a philosophical path rather than a sociological one, and its progress has been obstructed. While some of Bourdieu's philosophical arguments remain problematic, his reflexive sociology allows us to differentiate philosophical from sociological approaches, providing an alternative direction for Science Studies.     

Minimum spectral connectivity projection pursuit

Statistics and Computing - We study the problem of determining the optimal low-dimensional projection for maximising the separability of a binary partition of an unlabelled dataset, as measured by...     

Subnational migration in the United Kingdom: producing a consistent time series using a combination of available data and estimates

There is no single framework in place in the United Kingdom for collating and harmonizing the data on migration taking place between the subnational administrative units that constitute the home nations, together with the flows of international migration between these areas and the ‘rest of the world’. This paper proposes the construction of complete matrices of subnational migration statistics on an annual basis which can then be used to monitor migration trends throughout the UK in a comprehensive manner. The paper reviews how various ‘known’ flows are estimated by the national statistics agencies and develops estimates to fill in the gaps in the matrices. It then looks at changing patterns of migration in the UK between 2001/2002 and 2010/2011, showing that migration exhibits most activity in the middle of the decade. Flows within the home nations are the most consistent over time, while the patterns of international migration and migration across the borders of the home nations exhibit more substantial change. The latter flows, although relatively small in magnitude, have not previously been studied at the subnational level in any detail. Patterns of subnational internal and international net migration are found to be negatively correlated.     

Relationships between psychological capital,job satisfaction,and organizational commitment in the Saudi oil and petrochemical industries

During the past decade, Saudi Arabia experienced a significant social, economic, and organizational change. The rapid economic growth created a need for seasoned management professionals and necessitated the development of human capital. Psychological capital, a newly developed construct by academics and practitioners, is defined as the extent to which an individual operates in a positive psychological state, and this state is characterized by high self-efficacy, optimism, hope, and resiliency. By measuring the positive psychological constructs, an organization can learn about employees’ positive psychological states and how training and support can promote positive psychological states. Improving the positive psychological capital can lead to better organizational commitment, favorable organizational citizenship behaviors, lower employee absenteeism, and higher job satisfaction. This quantitative study examined the relationship among psychological capital, job satisfaction, and organizational commitment through a sample of managers in the Saudi Arabian oil and petrochemical industries.     

Multivariate locally stationary 2D wavelet processes with application to colour texture analysis

In this article we propose a novel framework for the modelling of non-stationary multivariate lattice processes. Our approach extends the locally stationary wavelet paradigm into the multivariate two-dimensional setting. As such the framework we develop permits the estimation of a spatially localised spectrum within a channel of interest and, more importantly, a localised cross-covariance which describes the localised coherence between channels. Associated estimation theory is also established which demonstrates that this multivariate spatial framework is properly defined and has suitable convergence properties. We also demonstrate how this model-based approach can be successfully used to classify a range of colour textures provided by an industrial collaborator, yielding superior results when compared against current state-of-the-art statistical image processing methods.     

The Effects of Imputing the Missing Standard Deviations on the Standard Error of Meta Analysis Estimates

A common problem in the meta analysis of continuous data is that some studies do not report sufficient information to calculate the standard deviation (SDs) of the treatment effect. One of the approaches in handling this problem is through imputation. This article examines the empirical implications of imputing the missing SDs on the standard error (SE) of the overall meta analysis estimate. The simulation results show that if the SDs are missing under Missing Completely at Random and Missing at Random mechanism, imputation is recommended. With non random missing, imputation can lead to overestimation of the SE of the estimate.