7,722 research outputs found
EU membership was a cultural symbol which Remainers approved and Leavers disliked
Provision of more facts and objective information would have been of marginal significance in the Brexit vote. Michael Cunningham (University of Wolverhampton) offers his reflections on the EU referendum that point to the existence of substantial political limitations of evidence. He argues that one observes a widespread tendency among many voters to be resistant to facts challenging positions they hold. He ..
The political limitations of evidence: a critique of the electoral reform society's it's good to talk
The Electoral Reform Society has called for more and better quality information to improve democratic debate in relation to referendums. This article argues that, particularly in relation to the European Union referendum, this would have had a marginal impact, because much of the debate was not reducible to facts and emotional and dispositional factors were of particular significance in the campaign
In-situ, real time gas composition measurements for SOFC's using laser spectroscopy
The use of standard gas composition measurement techniques, such as gas chromatography, in large scale solid oxide fuel cells (SOFC's) operating at high temperatures can be both complex and time consuming. One of the main constraints is the necessity to condense out the water vapour present in the gas streams prior to measurement in the Gas Chromatograph (GC). True gas compositions can only be extracted through back-calculation, with each measurement taking in the order of minutes, and a number of measurement points needed to make the final measurement. For system status monitoring such a time delay between condition changes and measurement is a serious disadvantage. One of the main concerns for systems running on natural gas is the risk of methane slippage through the internal reformer, which increases the risk of carbon formation on the SOFC anode, invariably leading to irreversible loss of performance. It is therefore highly advantageous to measure gas stream compositions within the SOFC system in real time, enabling a rapid response to composition deviation outside of acceptable limits. Gas chromatography can never be made to work as a real-time system status monitoring product solution. A suitable, in-situ, solution for measurement is tuneable diode laser spectroscopy, TDLS. Using this technique it is possible to measure both the gas concentration and system pressure simultaneously for a number of different species, without condensing out the water vapour: reducing analysis time considerably and reducing errors associated with back calculation. In this paper, data taken on an operational fuel cell system is presented for methane, and a comparison with results obtained using a GC is made
Preconditioning Kernel Matrices
The computational and storage complexity of kernel machines presents the
primary barrier to their scaling to large, modern, datasets. A common way to
tackle the scalability issue is to use the conjugate gradient algorithm, which
relieves the constraints on both storage (the kernel matrix need not be stored)
and computation (both stochastic gradients and parallelization can be used).
Even so, conjugate gradient is not without its own issues: the conditioning of
kernel matrices is often such that conjugate gradients will have poor
convergence in practice. Preconditioning is a common approach to alleviating
this issue. Here we propose preconditioned conjugate gradients for kernel
machines, and develop a broad range of preconditioners particularly useful for
kernel matrices. We describe a scalable approach to both solving kernel
machines and learning their hyperparameters. We show this approach is exact in
the limit of iterations and outperforms state-of-the-art approximations for a
given computational budget
Assessing housing quality and its impact on health, safety and sustainability
Background The adverse health and environmental
effects of poor housing quality are well established. A
central requirement for evidence-based policies and
programmes to improve housing standards is a valid,
reliable and practical way of measuring housing quality
that is supported by policy agencies, the housing sector,
researchers and the public.
Methods This paper provides guidance on the
development of housing quality-assessment tools that
link practical measures of housing conditions to their
effects on health, safety and sustainability, with
particular reference to tools developed in New Zealand
and England.
Results The authors describe how information on
housing quality can support individuals, agencies and the
private sector to make worthwhile improvements to the
health, safety and sustainability of housing. The
information gathered and the resultant tools developed
should be guided by the multiple purposes and end users
of this information. Other important issues outlined
include deciding on the scope, detailed content, practical
administration issues and how the information will be
analysed and summarised for its intended end users.
There are likely to be considerable benefits from
increased international collaboration and standardisation
of approaches to measuring housing hazards. At the
same time, these assessment approaches need to
consider local factors such as climate, geography,
culture, predominating building practices, important
housing-related health issues and existing building
codes.
Conclusions An effective housing quality-assessment
tool has a central role in supporting improvements to
housing. The issues discussed in this paper are designed
to motivate and assist the development of such tools
Fuzzy Modeling and Parallel Distributed Compensation for Aircraft Flight Control from Simulated Flight Data
A method is described that combines fuzzy system identification techniques with Parallel Distributed Compensation (PDC) to develop nonlinear control methods for aircraft using minimal a priori knowledge, as part of NASAs Learn-to-Fly initiative. A fuzzy model was generated with simulated flight data, and consisted of a weighted average of multiple linear time invariant state-space cells having parameters estimated using the equation-error approach and a least-squares estimator. A compensator was designed for each subsystem using Linear Matrix Inequalities (LMI) to guarantee closed-loop stability and performance requirements. This approach is demonstrated using simulated flight data to automatically develop a fuzzy model and design control laws for a simplified longitudinal approximation of the F-16 nonlinear flight dynamics simulation. Results include a comparison of flight data with the estimated fuzzy models and simulations that illustrate the feasibility and utility of the combined fuzzy modeling and control approach
Exploring the Relationship between Membership Turnover and Productivity in Online Communities
One of the more disruptive reforms associated with the modern Internet is the
emergence of online communities working together on knowledge artefacts such as
Wikipedia and OpenStreetMap. Recently it has become clear that these
initiatives are vulnerable because of problems with membership turnover. This
study presents a longitudinal analysis of 891 WikiProjects where we model the
impact of member turnover and social capital losses on project productivity. By
examining social capital losses we attempt to provide a more nuanced analysis
of member turnover. In this context social capital is modelled from a social
network perspective where the loss of more central members has more impact. We
find that only a small proportion of WikiProjects are in a relatively healthy
state with low levels of membership turnover and social capital losses. The
results show that the relationship between social capital losses and project
performance is U-shaped, and that member withdrawal has significant negative
effect on project outcomes. The results also support the mediation of turnover
rate and network density on the curvilinear relationship
An Investigation of the Effects of Categorization and Discrimination Training on Auditory Perceptual Space
Psychophysical phenomena such as categorical perception and the perceptual magnet effect indicate that our auditory perceptual spaces are warped for some stimuli. This paper investigates the effects of two different kinds of training on auditory perceptual space. It is first shown that categorization training, in which subjects learn to identify stimuli within a particular frequency range as members of the same category, can lead to a decrease in sensitivity to stimuli in that category. This phenomenon is an example of acquired similarity and apparently has not been previously demonstrated for a category-relevant dimension. Discrimination training with the same set of stimuli was shown to have the opposite effect: subjects became more sensitive to differences in the stimuli presented during training. Further experiments investigated some of the conditions that are necessary to generate the acquired similarity found in the first experiment. The results of these experiments are used to evaluate two neural network models of the perceptual magnet effect. These models, in combination with our experimental results, are used to generate an experimentally testable hypothesis concerning changes in the brain's auditory maps under different training conditions.Alfred P. Sloan Foundation and the National institutes of Deafness and other Communication Disorders (R29 02852); Air Force Office of Scientific Research (F49620-98-1-0108
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