Institutions and Long-Run Growth in the UK: the Role of Standards

In this paper we consider the relationship between the standards created by national standards bodies and long run economic growth, exploring the relationship in the context of the UK and the British Standards Institution (BSI). We suggest that standards provide a key enabling mechanism for the widespread diffusion of major technologies, while being generally supportive of incremental innovation and general technological understanding. In order to further understanding of this mechanism we measure the ‘output’ of the BSI by estimating the size of the BSI ‘catalogue’ available to the economy since its inception in 1901. The measure allows us to estimate an augmented production function for the UK economy over the period 1948-2002. Within a co-integrating framework, we find a statistically significant and unique co-integrating vector between labour productivity, the capital-labour ratio, exogenous technological progress and the BSI catalogue. The long-run elasticity of labour productivity with respect to the standards stock is estimated to be about 0.05, so that the rapid growth of the catalogue in the postwar period is associated with about 13% of the aggregate growth in labour productivity.standards, technological change, productivity.

Real-time FGPA implementation of a neuromorphic pitch detection system

This thesis explores the real-time implementation of a biologically inspired pitch detection system in digital electronics. Pitch detection is well understood and has been shown to occur in the initial stages of the auditory brainstem. By building such a system in digital hardware we can prove the feasibility of implementing neuromorphic systems using digital technology. This research not only aims to prove that such an implementation is possible but to investigate ways of achieving efficient and effective designs. We aim to achieve this complexity reduction while maintaining the fine granularity of the signal processing inherent in neural systems. By producing an efficient design we present the possibility of implementing the system within the available resources, thus producing a demonstrable system. This thesis presents a review of computational models of all the components within the pitch detection system. The review also identifies key issues relating to the efficient implementation and development of the pitch detection system. Four investigations are presented to address these issues for optimal neuromorphic designs of neuromorphic systems. The first investigation aims to produce the first-ever digital hardware implementation of the inner hair cell. The second investigation develops simplified models of the auditory nerve and the coincidence cell. The third investigation aims to reduce the most complex stage of the system, the stellate chopper cell array. Finally, we investigate implementing a large portion of the pitch detection system in hardware. The results contained in this thesis enable us to understand the feasibility of implementing such systems in real-time digital hardware. This knowledge may help researchers to make design decisions within the field of digital neuromorphic systems

Statistical Analyses and Reproducible Research

For various reasons, it is important, if not essential, to integrate the computations and code used in data analyses, methodological descriptions, simulations, etc. with the documents that describe and rely on them. This integration allows readers to both verify and adapt the statements in the documents. Authors can easily reproduce them in the future, and they can present the document\u27s contents in a different medium, e.g. with interactive controls. This paper describes a software framework for authoring and distributing these integrated, dynamic documents that contain text, code, data, and any auxiliary content needed to recreate the computations. The documents are dynamic in that the contents, including figures, tables, etc., can be recalculated each time a view of the document is generated. Our model treats a dynamic document as a master or ``source\u27\u27 document from which one can generate different views in the form of traditional, derived documents for different audiences. We introduce the concept of a compendium as both a container for the different elements that make up the document and its computations (i.e. text, code, data, ...), and as a means for distributing, managing and updating the collection. The step from disseminating analyses via a compendium to reproducible research is a small one. By reproducible research, we mean research papers with accompanying software tools that allow the reader to directly reproduce the results and employ the methods that are presented in the research paper. Some of the issues involved in paradigms for the production, distribution and use of such reproducible research are discussed

Sexting and Mental Health: A School-based Longitudinal Study Among Youth in Texas

Background: Sexting has emerged as a common socio-cultural problem in our society today. Few studies have estimated the prevalence of sexting among younger middle school youth and even fewer have assessed the relationship between sexting and mental health outcomes like anxiety and depression symptoms among middle school youth. Objectives: To estimate the prevalence of sexting among sixth and seventh-grade middle school students in a large urban school district in Southeast Texas and to assess its relationship with mental health outcomes (both anxiety and depression) among these youth. Methods: A retrospective analysis of an existing three-year randomized, two-arm, nested longitudinal study was conducted. Associations between sexting and depression symptoms; and sexting and anxiety symptoms were assessed via univariate and multivariate logistic analysis. Results: The prevalence of sexting among sixth graders was found to be 12%. Compared to youth who were not engaged in sexting, engagement in sexting was associated with significantly increased odds of depression and anxiety symptoms. Conclusion: Sexting is common among youth and is associated with poorer mental health outcomes such as anxiety and depression among these youth, but further validation of these findings is needed