Plant / Controller Optimization with applications to Integrated Surface Sizing and Feedback Controller Design for Autonomous Underwater Vehicles (AUVs)

This paper describes a solution to the following plant controller optimization (PCO) problem: given an autonomous underwater vehicle (AUV) - with a fixed baseline body configuration - that is required to operate over a finite number of representative trimming conditions in the vertical plane, determine the optimal size of the bow and stern control surfaces so that a weighted average J of the power required at trimming is minimized, subject to the conditions that: i) a given set of open loop requirements are met, and ii) stabilizing feedback controllers can be designed to meet desired time and frequency closed loop performance requirements about each trimming point. The solution proposed is rooted in the theory of Linear Matrix Inequalities (LMIs) and leads to efficient PCO algorithms that build on a recently released LMI Toolbox.The work of C. Silvestre and A. Pascoal was partially supported by the Portuguese PRAXIS XXI Programme under the INFANTE project. The work of the first author was also supported by NATO Scholarship 17/A/94/PO The second author benefited from a NATO Fellowship during his 1996-98 sabbatical at the Naval Postgraduate School

Polyproline is a minimal antifreeze protein mimetic and enhances the cryopreservation of cell monolayers

Tissue engineering, gene therapy, drug screening and emerging regenerative medicine therapies are fundamentally reliant on high-quality adherent cell culture, but current methods to cryopreserve cells in this format can give low cell yields and requires large volumes of solvent 'antifreezes'. Herein we report polyproline is a minimum (bio)synthetic mimic of antifreeze proteins, which is accessible by solution, solid phase and recombinant methods. We demonstrate that polyproline has ice recrystallization inhibition activity linked to its amphipathic helix and that it enhances the DMSO- cryopreservation of adherent cell lines. Polyproline may be a versatile additive in the emerging field of macromolecular cryoprotectants

Causation, Measurement Relevance and No-conspiracy in EPR

In this paper I assess the adequacy of no-conspiracy conditions employed in the usual derivations of the Bell inequality in the context of EPR correlations. First, I look at the EPR correlations from a purely phenomenological point of view and claim that common cause explanations of these cannot be ruled out. I argue that an appropriate common cause explanation requires that no-conspiracy conditions are re-interpreted as mere common cause-measurement independence conditions. In the right circumstances then, violations of measurement independence need not entail any kind of conspiracy (nor backwards in time causation). To the contrary, if measurement operations in the EPR context are taken to be causally relevant in a specific way to the experiment outcomes, their explicit causal role provides the grounds for a common cause explanation of the corresponding correlations.Comment: 20 pages, 1 figur

Noisy Kuramoto-Sivashinsky equation for an erosion model

We derive the continuum equation for a discrete model for ion sputtering. We follow an approach based on the master equation, and discuss how it can be truncated to a Fokker-Planck equation and mapped to a discrete Langevin equation. By taking the continuum limit, we arrive at the Kuramoto-Sivashinsky equation with a stochastic noise term.Comment: latex (w/ multicol.sty), 4 pages; to appear in Physical Review E (Oct 1996

Assessing the spatial impact of policy interventions on real-estate values: an exemplar of the use of the hybrid hedonic/repeat-sales method

This paper sets out to make a contribution to the extensive literature that seeks to develop methods that allow rigorous and robust analysis of the spatial and temporal impacts of public policy interventions on property (real-estate) values. It argues that the hybrid repeat-sales/hedonic method developed in real-estate studies over the last 30 years has considerable, but as yet under-developed, potential as a policy analysis tool. Using data from Glasgow, UK, the empirical analysis illustrates how the technique can be used to understand the spatial spillovers and the dynamic temporal effects of a historic £100 million state-led, area-based, urban-renewal programme, New Life for Urban Scotland. The paper concludes by arguing that, with the rise in the availability of rich geocoded, micro-datasets, this framework is sufficiently flexible to be used to evaluate the real-estate market impacts of a wide range of public policy interventions. Significantly, as the case study demonstrates, the framework overcomes some of the sustained criticisms of the more commonly used hedonic modelling approach. There is, however, still much to do to enhance the technical qualities of the models through further application

Socially-mediated arousal and contagion within domestic chick broods

Emotional contagion – an underpinning valenced feature of empathy – is made up of simpler, potentially dissociable social processes which can include socially-mediated arousal and behavioural/physiological contagion. Previous studies of emotional contagion have often conflated these processes rather than examining their independent contribution to empathic response. We measured socially-mediated arousal and contagion in 9-week old domestic chicks (n = 19 broods), who were unrelated but raised together from hatching. Pairs of observer chicks were exposed to two conditions in a counterbalanced order: air puff to conspecifics (AP) (during which an air puff was applied to three conspecifics at 30 s intervals) and control with noise of air puff (C) (during which the air puff was directed away from the apparatus at 30 s intervals). Behaviour and surface eye temperature of subjects and observers were measured throughout a 10-min pre-treatment and 10-min treatment period. Subjects and observers responded to AP with increased freezing, and reduced preening and ground pecking. Subjects and observers also showed reduced surface eye temperature - indicative of stress-induced hyperthermia. Subject-Observer behaviour was highly correlated within broods during both C and AP conditions, but with higher overall synchrony during AP. We demonstrate the co-occurrence of socially-mediated behavioural and physiological arousal and contagion; component features of emotional contagion