A Bayesian formulation of search, control and the exploration/exploitation trade-off

A new approach to optimisation is introduced based on a precise probabilistic statement of what is ideally required of an optimisation method. It is convenient to express the formalism in terms of the control of a stationary environment. This leads to an objective function for the controller which unifies the objectives of exploration and exploitation, thereby providing a quantitative principle for managing this trade-off. This is demonstrated using a variant of the multi-armed bandit problem. This approach opens new possibilities for optimisation algorithms, particularly by using neural network or other adaptive methods for the adaptive controller. It also opens possibilities for deepening understanding of existing methods. The realisation of these possibilities requires research into practical approximations of the exact formalism.

Social control and knowledge in democratic societies

In this article we introduce the notions of knowledge policy and the politics of knowledge. These have to be distinguished from the older, well-known terms of research policy, or science and technology policy. While the latter aim to foster the development of innovations in knowledge and its applications, the former is aware of side effects of new knowledge and tries to address them. While research policy takes the aims of innovations as largely unproblematic (insofar as they help improving national competitiveness), knowledge policy tries to govern (regulate, control, restrict, or even forbid) the production of knowledge.

"Well did you feel jealous?" Control and ideology in police interviews with rape complainants

The methods used by the UK Police to investigate complaints of rape have unsurprisingly come under much scrutiny in recent times, with a 2007 joint report on behalf of HM Crown Prosecution Service Inspectorate and HM Inspectorate of Constabulary concluding that there were many areas where improvements should be made. The research reported here forms part of a larger project which draws on various discourse analytical tools to identify the processes at work during police interviews with women reporting rape. Drawing on a corpus of video recorded police interviews with women reporting rape, this study applies a two pronged analysis to reveal the presence of these ideologies. Firstly, an analysis of the discourse markers ‘well’ and ‘so’ demonstrates the control exerted on the interaction by interviewing officers, as they attach importance to certain facts while omitting much of the information provided by the victim. Secondly, the interpretative repertoires relied upon by officers to ‘make sense’ of victim’s accounts are subject to scrutiny. As well as providing micro-level analyses which demonstrate processes of interactional control at the local level, the findings of these analyses can be shown to relate to a wider context – specifically prevailing ideologies about sexual violence in society as a whole.

Quantifying the pathology of neurodegenerative disorders:Quantitative measurements, sampling strategies and data analysis

The use of quantitative methods has become increasingly important in the study of neurodegenerative disease. Disorders such as Alzheimer's disease (AD) are characterized by the formation of discrete, microscopic, pathological lesions which play an important role in pathological diagnosis. This article reviews the advantages and limitations of the different methods of quantifying the abundance of pathological lesions in histological sections, including estimates of density, frequency, coverage, and the use of semiquantitative scores. The major sampling methods by which these quantitative measures can be obtained from histological sections, including plot or quadrat sampling, transect sampling, and point-quarter sampling, are also described. In addition, the data analysis methods commonly used to analyse quantitative data in neuropathology, including analyses of variance (ANOVA) and principal components analysis (PCA), are discussed. These methods are illustrated with reference to particular problems in the pathological diagnosis of AD and dementia with Lewy bodies (DLB).

The role of leader-member exchanges in mediating the relationship between locus of control and work reactions

The relationship between locus of control, the quality of exchanges between subordinates and leaders (LMX), and a variety of work-related reactions (intrinsic/extrinsic job satisfaction, work-related well-being, and organizational commitment) are examined. It was predicted that people with an internal locus of control develop better quality relations with their manager and this, in turn, results in more favourable work-related reactions. Results from two different samples (N=404, and N=51) supported this prediction, and also showed that LMX either fully, or partially, mediated the relationship between locus of control and all the work-related reactions.

Simultaneous clock recovery and data regeneration using a nonlinear optical loop mirror as an all-optical mixer

High-speed optical clock recovery, demultiplexing and data regeneration will be integral parts of any future photonic network based on high bit-rate OTDM. Much research has been conducted on devices that perform these functions, however to date each process has been demonstrated independently. A very promising method of all-optical switching is that of a semiconductor optical amplifier-based nonlinear optical loop mirror (SOA-NOLM). This has various advantages compared with the standard fiber NOLM, most notably low switching power, compact size and stability. We use the SOA-NOLM as an all-optical mixer in a classical phase-locked loop arrangement to achieve optical clock recovery, while at the same time achieving data regeneration in a single compact device