13,183 research outputs found
Event Analysis of Pulse-reclosers in Distribution Systems Through Sparse Representation
The pulse-recloser uses pulse testing technology to verify that the line is
clear of faults before initiating a reclose operation, which significantly
reduces stress on the system components (e.g. substation transformers) and
voltage sags on adjacent feeders. Online event analysis of pulse-reclosers are
essential to increases the overall utility of the devices, especially when
there are numerous devices installed throughout the distribution system. In
this paper, field data recorded from several devices were analyzed to identify
specific activity and fault locations. An algorithm is developed to screen the
data to identify the status of each pole and to tag time windows with a
possible pulse event. In the next step, selected time windows are further
analyzed and classified using a sparse representation technique by solving an
l1-regularized least-square problem. This classification is obtained by
comparing the pulse signature with the reference dictionary to find a set that
most closely matches the pulse features. This work also sheds additional light
on the possibility of fault classification based on the pulse signature. Field
data collected from a distribution system are used to verify the effectiveness
and reliability of the proposed method.Comment: Accepted in: 19th International Conference on Intelligent System
Application to Power Systems (ISAP), San Antonio, TX, 201
External and internal noise surveys of London primary schools
Internal and external noise surveys have been carried out around schools in London, UK, to provide information on typical levels and sources to which children are exposed while at school. Noise levels were measured outside 142 schools, in areas away from flightpaths into major airports. 86% of the schools surveyed were exposed to noise from road traffic, the average external noise level outside a school being 57 dB LAeq. Detailed internal noise surveys have been carried out in 140 classrooms in 16 schools, together with classroom observations. It was found that noise levels inside classrooms depend upon the activities in which the children are engaged, with a difference of 20 dB LAeq between the 'quietest' and 'noisiest' activities. The average background noise level in classrooms exceeds the level recommended in current standards. The number of children in the classroom was found to affect noise levels. External noise influenced internal noise levels only when children were engaged in the quietest classroom activities. The effects of the age of the school buildings and types of window upon internal noise were examined but results were inconclusive
Using meta-patterns to construct patterns
International audienceThe pattern notion defines techniques allowing the existing knowledge reuse. Usually, the knowledge encapsulated in these patterns is stored in classic library repositories that quickly become overcrowded. To solve this problem, [1] proposes the use of process maps in order to organize and select them. But the completeness of the maps is a very important problem that has to be solved in order to offer a useful guidance to the method engineer. This paper proposes a guideline pattern construction technique guiding engineers when creating the maps
A local-global principle for linear dependence of noncommutative polynomials
A set of polynomials in noncommuting variables is called locally linearly
dependent if their evaluations at tuples of matrices are always linearly
dependent. By a theorem of Camino, Helton, Skelton and Ye, a finite locally
linearly dependent set of polynomials is linearly dependent. In this short note
an alternative proof based on the theory of polynomial identities is given. The
method of the proof yields generalizations to directional local linear
dependence and evaluations in general algebras over fields of arbitrary
characteristic. A main feature of the proof is that it makes it possible to
deduce bounds on the size of the matrices where the (directional) local linear
dependence needs to be tested in order to establish linear dependence.Comment: 8 page
Goal setting and strategies to enhance goal pursuit in adult rehabilitation: summary of a Cochrane systematic review and meta-analysis
This is the author proof version of an article accepted for publication in European Journal of Physical and Rehabilitation Medicine 2016.Final version available from the publisher.This paper is based on a Cochrane Review published in the Cochrane Database of Systematic Reviews (CDSR) 2015, Issue 7, Art. No.: CD009727, DOI:
10.1002/14651858 (see www.thecochranelibrary.com for information?Article first published online: January 15, 2016.INTRODUCTION: Goal setting is considered an essential part of rehabilitation, but approaches to goal setting vary with no consensus regarding
the best approach. The aim of this systematic review and meta-analysis was to assess the effects of goal setting and strategies to enhance the
pursuit of goals on improving outcomes in adult rehabilitation.
EVIDENCE ACQUISITION: We searched CENTRAL, MEDLINE, EMBASE, four other databases and three trial registries for randomized
control trials (RCTs), cluster RCTs, or quasi-RCTs published before December 2013. Two reviewers independently screened all search results,
then critically appraised and extracted data on all included studies. We identified 39 trials, which differed in clinical context, participant populations,
research question related to goal use, and outcomes measured. Eighteen studies compared goal setting, with or without strategies to
enhance goal pursuit, to no goal setting.
EVIDENCE SYNTHESIS: These 18 studies provided very low-quality evidence for a moderate effect size that any type of goal setting is better
than no goal setting for improving health-related quality of life or self-reported emotional status (N.=446, standard mean difference [SMD]=0.53,
95% confidence interval [CI]: 0.17 to 0.88), and very low-quality evidence of a large effect size for self-efficacy (N.=108, SMD=1.07, 95%Â CI: 0.64 to 1.49). Fourteen studies compared a structured approach to goal setting to âusual careâ goal setting, where some goals may have been set
but no structured approach was followed. These studies provided very low-quality evidence for a small effect size that more structured goal setting
results in higher patient self-efficacy (N.=134, SMD=0.37, 95%Â CI: 0.02 to 0.71). No conclusive evidence was found to support the notion
that goal setting, or structured goal setting in comparison to âusual careâ goal setting, changes outcomes for patients for measures of participation,
activity, or engagement in rehabilitation programs.
CONCLUSIONS: This review found a large and increasing amount of research being conducted on goal setting in rehabilitation. However, problems
with study design and diversity in methods used means the quality of evidence to support estimated effect sizes is poor. Further research is
highly likely to change reported estimates of effect size arising from goal setting in rehabilitation.SDâs position at the University of Exeter Medical School is supported by the National Institute for Health Research (NIHR) Collaboration for Leadership
in Applied Health Research and Care South West Peninsula at the Royal Devon and Exeter NHS Foundation Trust. The views expressed are those of the
author(s) and not necessarily those of the National Health Service (NHS), the NIHR or the Department of Health
Quantum mechanical ab-initio simulation of the electron screening effect in metal deuteride crystals
In antecedent experiments the electron screening energies of the d+d
reactions in metallic environments have been determined to be enhanced by an
order of magnitude in comparison to the case of gaseous deuterium targets. The
analytical models describing averaged material properties have not been able to
explain the experimental results so far. Therefore, a first effort has been
undertaken to simulate the dynamics of reacting deuterons in a metallic lattice
by means of an ab-initio Hartree-Fock calculation of the total electrostatic
force between the lattice and the successively approaching deuterons via path
integration. The calculations have been performed for Li and Ta, clearly
showing a migration of electrons from host metallic to the deuterium atoms.
However, in order to avoid more of the necessary simplifications in the model
the utilization of a massive parallel supercomputer would be required.Comment: 11 pages, 12 figures, svjour class. To be published in Eur. Phys. J.
Goal setting and strategies to enhance goal pursuit for adults with acquired disability participating in rehabilitation.
Published onlineJournal ArticleMeta-AnalysisResearch Support, Non-U.S. Gov'tReviewBACKGROUND: Goal setting is considered a key component of rehabilitation for adults with acquired disability, yet there is little consensus regarding the best strategies for undertaking goal setting and in which clinical contexts. It has also been unclear what effect, if any, goal setting has on health outcomes after rehabilitation. OBJECTIVES: To assess the effects of goal setting and strategies to enhance the pursuit of goals (i.e. how goals and progress towards goals are communicated, used, or shared) on improving health outcomes in adults with acquired disability participating in rehabilitation. SEARCH METHODS: We searched CENTRAL, MEDLINE, EMBASE, four other databases and three trials registers to December 2013, together with reference checking, citation searching and contact with study authors to identify additional studies. We did not impose any language or date restrictions. SELECTION CRITERIA: Randomised controlled trials (RCTs), cluster-RCTs and quasi-RCTs evaluating the effects of goal setting or strategies to enhance goal pursuit in the context of adult rehabilitation for acquired disability. DATA COLLECTION AND ANALYSIS: Two authors independently reviewed search results for inclusion. Grey literature searches were conducted and reviewed by a single author. Two authors independently extracted data and assessed risk of bias for included studies. We contacted study authors for additional information. MAIN RESULTS: We included 39 studies (27 RCTs, 6 cluster-RCTs, and 6 quasi-RCTs) involving 2846 participants in total. Studies ranged widely regarding clinical context and participants' primary health conditions. The most common health conditions included musculoskeletal disorders, brain injury, chronic pain, mental health conditions, and cardiovascular disease.Eighteen studies compared goal setting, with or without strategies to enhance goal pursuit, to no goal setting. These studies provide very low quality evidence that including any type of goal setting in the practice of adult rehabilitation is better than no goal setting for health-related quality of life or self-reported emotional status (8 studies; 446 participants; standardised mean difference (SMD) 0.53, 95% confidence interval (CI) 0.17 to 0.88, indicative of a moderate effect size) and self-efficacy (3 studies; 108 participants; SMD 1.07, 95% CI 0.64 to 1.49, indicative of a moderate to large effect size). The evidence is inconclusive regarding whether goal setting results in improvements in social participation or activity levels, body structure or function, or levels of patient engagement in the rehabilitation process. Insufficient data are available to determine whether or not goal setting is associated with more or fewer adverse events compared to no goal setting.Fourteen studies compared structured goal setting approaches, with or without strategies to enhance goal pursuit, to 'usual care' that may have involved some goal setting but where no structured approach was followed. These studies provide very low quality evidence that more structured goal setting results in higher patient self-efficacy (2 studies; 134 participants; SMD 0.37, 95% CI 0.02 to 0.71, indicative of a small effect size) and low quality evidence for greater satisfaction with service delivery (5 studies; 309 participants; SMD 0.33, 95% CI 0.10 to 0.56, indicative of a small effect size). The evidence was inconclusive regarding whether more structured goal setting approaches result in higher health-related quality of life or self-reported emotional status, social participation, activity levels, or improvements in body structure or function. Three studies in this group reported on adverse events (death, re-hospitalisation, or worsening symptoms), but insufficient data are available to determine whether structured goal setting is associated with more or fewer adverse events than usual care.A moderate degree of heterogeneity was observed in outcomes across all studies, but an insufficient number of studies was available to permit subgroup analysis to explore the reasons for this heterogeneity. The review also considers studies which investigate the effects of different approaches to enhancing goal pursuit, and studies which investigate different structured goal setting approaches. It also reports on secondary outcomes including goal attainment and healthcare utilisation. AUTHORS' CONCLUSIONS: There is some very low quality evidence that goal setting may improve some outcomes for adults receiving rehabilitation for acquired disability. The best of this evidence appears to favour positive effects for psychosocial outcomes (i.e. health-related quality of life, emotional status, and self-efficacy) rather than physical ones. Due to study limitations, there is considerable uncertainty regarding these effects however, and further research is highly likely to change reported estimates of effect
International capital mobility in an era of globalisation: adding a political dimension to the 'FeldsteinâHorioka Puzzle'
The debate about the scope of feasible policy-making in an era of globalisation continues to be set within the context of an assumption that national capital markets are now perfectly integrated at the international level. However, the empirical evidence on international capital mobility contradicts such an assumption. As a consequence, a significant puzzle remains. Why is it, in a world in which the observed pattern of capital flows is indicative of a far from globalised reality, that public policy continues to be constructed in line with more extreme variants of the globalisation hypothesis? I attempt to solve this puzzle by arguing that ideas about global capital market integration have an independent causal impact on political outcomes which extends beyond that which can be attributed to the extent of their actual integration
Ground-state properties of rutile: electron-correlation effects
Electron-correlation effects on cohesive energy, lattice constant and bulk
compressibility of rutile are calculated using an ab-initio scheme. A
competition between the two groups of partially covalent Ti-O bonds is the
reason that the correlation energy does not change linearly with deviations
from the equilibrium geometry, but is dominated by quadratic terms instead. As
a consequence, the Hartree-Fock lattice constants are close to the experimental
ones, while the compressibility is strongly renormalized by electronic
correlations.Comment: 1 figure to appear in Phys. Rev.
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