3,401 research outputs found
DLCQ and Plane Wave Matrix Big Bang Models
We study the generalisations of the Craps-Sethi-Verlinde matrix big bang
model to curved, in particular plane wave, space-times, beginning with a
careful discussion of the DLCQ procedure. Singular homogeneous plane waves are
ideal toy-models of realistic space-time singularities since they have been
shown to arise universally as their Penrose limits, and we emphasise the role
played by the symmetries of these plane waves in implementing the flat space
Seiberg-Sen DLCQ prescription for these curved backgrounds. We then analyse
various aspects of the resulting matrix string Yang-Mills theories, such as the
relation between strong coupling space-time singularities and world-sheet
tachyonic mass terms. In order to have concrete examples at hand, in an
appendix we determine and analyse the IIA singular homogeneous plane wave -
null dilaton backgrounds.Comment: 29 pages, v2: reference added + minor cosmetic correction
Application of the European Customer Satisfaction Index to Postal Services. Structural Equation Models versus Partial Least Squares
Customer satisfaction and retention are key issues for organizations in today’s competitive market place. As such, much research and revenue has been invested in developing accurate ways of assessing consumer satisfaction at both the macro (national) and micro (organizational) level, facilitating comparisons in performance both within and between industries. Since the instigation of the national customer satisfaction indices (CSI), partial least squares (PLS) has been used to estimate the CSI models in preference to structural equation models (SEM) because they do not rely on strict assumptions about the data. However, this choice was based upon some misconceptions about the use of SEM’s and does not take into consideration more recent advances in SEM, including estimation methods that are robust to non-normality and missing data. In this paper, both SEM and PLS approaches were compared by evaluating perceptions of the Isle of Man Post Office Products and Customer service using a CSI format. The new robust SEM procedures were found to be advantageous over PLS. Product quality was found to be the only driver of customer satisfaction, while image and satisfaction were the only predictors of loyalty, thus arguing for the specificity of postal services.European Customer Satisfaction Index; ECSI; Structural Equation Models; Robust Statistics; Missing Data; Maximum Likelihood
Editorial: The engaged university
Gateways has been a place where university researchers and community members join together to better understand the broad range of issues confronting communities across the globe, including academic communities. It is well positioned to promote a healthy debate among community members, researchers and policy-makers around scores of problems. We will continue to be a resource that is free to the thousands of our readers
Sustainability in the theology curriculum
This is the author's PDF version of a book chapter available in Sustainability education: Perspectives and practice across higher education. Edited by Paula Jones, David Selby, and Stephen Sterling. London: Earthscan, 2010. This book chapter was reproduced with the kind permission of EasthScan.This book chapter discusses how theology has the potential to contribute to education for sustainable development
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