Planning: Applied Rationality or Contingent Practice?

This paper develops an interactional approach to planning in organisations that draws out the relevance of both rationalist and contingent models of planning. The distinction between these two models is developed in the light of the modernist / postmodernist debate to provide a set of theoretical issues to with planning in organisations. These issues are explored in the context of planning carried out in two empirically studied settings, a health authority and a school. The two models are found to provide resources for organisations and participants in these settings, both to proceed with planning activity and to account for it. Neither model is however adequate to describe the process of planning which is always a practical and situated activity whose character emerges in the process of interaction

Dealing with dirt : servicing and repairing cars.

This paper explores the significance of dirt in the work of technicians who service and repair private cars. Rather than being useful in understanding how dirt is dealt with, the historical and anthropological analyses of dirt are shown to be overly concerned with cultural significance and the idea that dirt is no more than ‘matter out of place’. Such accounts suppress the more common sense approach that dirt is unpleasant to human beings and is to be avoided if possible. In work such as garage servicing and repairs, dirt has to be confronted and dealt with pragmatically, according to the consequences of its presence, rather than symbolically according to its cultural meaning. The writing of Sartre on slime provides a more persuasive explanation both for the ambivalence towards ambiguous materials of slime and dirt and for the moral connotations that attach to them. Everett Hughes’s account of a ‘moral division of labour’ in which distinctions are made concerning dirty work fits with some of the visible hierarchical distinctions in the garage setting. But it is the variability of practices, both between garages and between technicians in a similar setting, that suggests dealing with dirt is a practical matter that is not prescribed by ritual or cultural significance

Relics of spatial curvature in the primordial non-gaussianity

We study signatures in the Cosmic Microwave Background (CMB) induced by the presence of strong spatial curvature prior to the epoch of inflation which generated our present universe. If inflation does not last sufficiently long to drive the large-scale spatial curvature to zero, then presently observable scales may have left the horizon while spatial slices could not be approximated by a flat, Euclidean geometry. We compute corrections to the power spectrum and non-gaussianity of the CMB temperature anisotropy in this scenario. The power spectrum does not receive significant corrections and is a weak diagnostic of the presence of curvature in the initial conditions, unless its running can be determined with high accuracy. However, the bispectral non-gaussianity parameter f_NL receives modifications on the largest observable scales. We estimate that the maximum signal would correspond to f_NL ~ 0.3, which is out of reach for present-day microwave background experiments.Comment: 23 pages, uses ioplatex.sty. v2: only bibliographic change

Observations of acoustic emission activity during gear defect diagnosis.

It is widely recognised that acoustic emission (AE) is gaining ground as a non- destructive technique (NDT) for health diagnosis on rotating machinery. The source of AE is attributed to the release of stored elastic energy that manifests itself in the form of elastic waves that propagate in all directions on the surface of a material. These detectable AE waves can provide useful information about the health condition of a machine. This paper reports on part of an ongoing experimental investigation on the application of AE for gear defect diagnosis. Furthermore, the possibility of monitoring gear defects from the bearing casing is examined. It is concluded that AE offers a complimentary tool for health monitoring of gears

Fixed-Form Variational Posterior Approximation through Stochastic Linear Regression

We propose a general algorithm for approximating nonstandard Bayesian posterior distributions. The algorithm minimizes the Kullback-Leibler divergence of an approximating distribution to the intractable posterior distribution. Our method can be used to approximate any posterior distribution, provided that it is given in closed form up to the proportionality constant. The approximation can be any distribution in the exponential family or any mixture of such distributions, which means that it can be made arbitrarily precise. Several examples illustrate the speed and accuracy of our approximation method in practice

Forecasting the public finances in the Treasury

This article describes the methods used by the Treasury and other government departments for making forecasts of the public finances. A highly detailed approach is required because of the Treasury’s budgetary role, but the aggregated results are subjected to careful ‘top-down’ checks. Forecasts have a necessary role in fiscal policy. But they are subject to large margins of error, and should be presented and used with caution.

Anagram-free Graph Colouring

An anagram is a word of the form $WP$ where $W$ is a non-empty word and $P$ is a permutation of $W$. We study anagram-free graph colouring and give bounds on the chromatic number. Alon et al. (2002) asked whether anagram-free chromatic number is bounded by a function of the maximum degree. We answer this question in the negative by constructing graphs with maximum degree 3 and unbounded anagram-free chromatic number. We also prove upper and lower bounds on the anagram-free chromatic number of trees in terms of their radius and pathwidth. Finally, we explore extensions to edge colouring and $k$-anagram-free colouring.Comment: Version 2: Changed 'abelian square' to 'anagram' for consistency with 'Anagram-free colourings of graphs' by Kam\v{c}ev, {\L}uczak, and Sudakov. Minor changes based on referee feedbac