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Overcoming restrictive technologies in police call centres: A human agency perspective
Call centres in the police force are restrictive information systems which tend to present call
operators with constraints that they need to overcome using their experience in order to offer
better services to the public. This paper is looking at how elements of human agency come in
to play and help users’ enactment against restrictive technologies. Information systems
research on human agency has been mainly focused on the examination of whether agency
lies within human or machines or both while in this paper we take a different approach and
we clearly describe how human agency is enacted in practice. We use empirical data from
contact centres and operational rooms of five UK police forces. After extensive observations
we present how police call handlers manipulate digital information efficiently through human
agency. The theoretical framework is based on the three elements of agency theory (iteration,
projectivity and practical evaluation) The research findings assert that call handlers
overcome the restrictions of the system by forming human-digital networks and using mental
structures from their past experience in order to cope with the task at hand. The paper
concludes by drawing implications for theory and practice and suggests future research
directions
A critical layer model for turbulent pipe flow
A model-based description of the scaling and radial location of turbulent
fluctuations in turbulent pipe flow is presented and used to illuminate the
scaling behaviour of the very large scale motions. The model is derived by
treating the nonlinearity in the perturbation equation (involving the Reynolds
stress) as an unknown forcing, yielding a linear relationship between the
velocity field response and this nonlinearity. We do not assume small
perturbations. We examine propagating modes, permitting comparison of our
results to experimental data, and identify the steady component of the velocity
field that varies only in the wall-normal direction as the turbulent mean
profile. The "optimal" forcing shape, that gives the largest velocity response,
is assumed to lead to modes that will be dominant and hence observed in
turbulent pipe flow.
An investigation of the most amplified velocity response at a given
wavenumber-frequency combination reveals critical layer-like behaviour
reminiscent of the neutrally stable solutions of the Orr-Sommerfeld equation in
linearly unstable flow. Two distinct regions in the flow where the influence of
viscosity becomes important can be identified, namely a wall layer that scales
with and a critical layer, where the propagation velocity is equal
to the local mean velocity, that scales with in pipe flow. This
framework appears to be consistent with several scaling results in wall
turbulence and reveals a mechanism by which the effects of viscosity can extend
well beyond the immediate vicinity of the wall.Comment: Submitted to the Journal of Fluid Mechanics and currently under
revie
On the design of optimal compliant walls for turbulence control
This paper employs the theoretical framework developed by Luhar et al. (J.
Fluid Mech., 768, 415-441) to consider the design of compliant walls for
turbulent skin friction reduction. Specifically, the effects of simple
spring-damper walls are contrasted with the effects of more complex walls
incorporating tension, stiffness and anisotropy. In addition, varying mass
ratios are tested to provide insight into differences between aerodynamic and
hydrodynamic applications. Despite the differing physical responses, all the
walls tested exhibit some important common features. First, the effect of the
walls (positive or negative) is greatest at conditions close to resonance, with
sharp transitions in performance across the resonant frequency or phase speed.
Second, compliant walls are predicted to have a more pronounced effect on
slower-moving structures because such structures generally have larger
wall-pressure signatures. Third, two-dimensional (spanwise constant) structures
are particularly susceptible to further amplification. These features are
consistent with many previous experiments and simulations, suggesting that
mitigating the rise of such two-dimensional structures is essential to
designing performance-improving walls. For instance, it is shown that further
amplification of such large-scale two-dimensional structures explains why the
optimal anisotropic walls identified by Fukagata et al. via DNS (J. Turb., 9,
1-17) only led to drag reduction in very small domains. The above observations
are used to develop design and methodology guidelines for future research on
compliant walls
JISC Final Report: IncReASe (Increasing Repository Content through Automation and Services)
The IncReASe (Increasing Repository Content through Automation and Services) was an eighteen month project (subsequently extended to twenty months) to enhance White Rose Research Online (WRRO)1. WRRO is a shared repository of research outputs (primarily publications) from the Universities of Leeds, Sheffield and York; it runs on the EPrints open source repository platform. The repository was created in 2004 and had steady growth but, in common with many other similar repositories, had difficulty in achieving a “critical mass” of content and in becoming truly embedded within researchers’ workflows. The main aim of the IncReASe project was to assess ingestion routes into WRRO with a view to lowering barriers to deposit. We reviewed the feasibility of bulk import of pre-existing metadata and/or full-text research outputs, hoping this activity would have a positive knock-on effect on repository growth and embedding. Prior to the project, we had identified researchers’ reluctance to duplicate effort in metadata creation as a significant barrier to WRRO uptake; we investigated how WRRO might share data with internal and external IT systems. This work included a review of how WRRO, as an institutional based repository, might interact with the subject repository of the Economic and Social Research Council (ESRC). The project addressed four main areas: (i) researcher behaviour: we investigated researcher awareness, motivation and workflow through a survey of archiving activity on the university web sites, a questionnaire and discussions with researchers (ii) bulk import: we imported data from local systems, including York’s submission data for the 2008 Research Assessment Exercise (RAE), and developed an import plug-in for use with the arXiv2 repository (iii) interoperability: we looked at how WRRO might interact with university and departmental publication databases and ESRC’s repository. (iv) metadata: we assessed metadata issues raised by importing publication data from a variety of sources. A number of outputs from the project have been made available from the IncReASe project web site http://eprints.whiterose.ac.uk/increase/. The project highlighted the low levels of researcher awareness of WRRO - and of broader open access issues, including research funders’ deposit requirements. We designed some new publicity materials to start to address this. Departmental publication databases provided a useful jumping off point for advocacy and liaison; this activity was helpful in promoting awareness of WRRO. Bulk import proved time consuming – both in terms of adjusting EPrints plug-ins to incorporate different datasets and in the staff time required to improve publication metadata. A number of deposit scenarios were developed in the context of our work with ESRC; we concentrated on investigating how a local deposit of a research paper and attendant metadata in WRRO might be used to populate ESRC’s repository. This work improved our understanding of researcher workflows and of the SWORD protocol as a potential (if partial) solution to the single deposit, multiple destination model we wish to develop; we think the prospect of institutional repository / ESRC data sharing is now a step closer. IncReASe experienced some staff recruitment difficulties. It was also necessary to adapt the project to the changing IT landscape at the three partner institutions – in particular, the introduction of a centralised publication management system at the University of Leeds. Although these factors had some impact on deliverables, the aims and objectives of the project were largely achieved
Quantification of the density of cooperative neighboring synapses required to evoke endocannabinoid signaling
The spatial pattern of synapse activation may impact on synaptic plasticity. This applies to the synaptically-evoked endocannabinoid-mediated short-term depression at the parallel fiber (PF) to Purkinje cell synapse, the occurrence of which requires close proximity between the activated synapses. Here, we determine quantitatively this required proximity, helped by the geometrical organization of the cerebellar molecular layer. Transgenic mice expressing a calcium indicator selectively in granule cells enabled the imaging of action potential-evoked presynaptic calcium rise in isolated, single PFs. This measurement was used to derive the number of PFs activated within a beam of PFs stimulated in the molecular layer, from which the density of activated PFs (input density) was calculated. This density was on average 2.8μm in sagittal slices and twice more in transverse slices. The synaptically-evoked endocannabinoid-mediated suppression of excitation (SSE) evoked by ten stimuli at 200Hz was determined from the monitoring of either postsynaptic responses or presynaptic calcium rise. The SSE was significantly larger when recorded in transverse slices, where the input density is larger. The exponential description of the SSE plotted as a function of the input density suggests that the SSE is half reduced when the input density decreases from 6 to 2μm. We conclude that, although all PFs are truncated in an acute sagittal slice, half of them remain respondent to stimulation, and activated synapses need to be closer than 1.5μm to synergize in endocannabinoid signaling. © 2013 The authors
Magnetization in electron- and Mn- doped SrTiO3
Mn-doped SrTiO_3.0, when synthesized free of impurities, is a paramagnetic
insulator with interesting dielectric properties. Since delocalized charge
carriers are known to promote ferromagnetism in a large number of systems via
diverse mechanisms, we have looked for the possibility of any intrinsic,
spontaneous magnetization by simultaneous doping of Mn ions and electrons into
SrTiO_3 via oxygen vacancies, thereby forming SrTi_(1-x)Mn_xO_(3-d), to the
extent of making the doped system metallic. We find an absence of any
enhancement of the magnetization in the metallic sample when compared with a
similarly prepared Mn doped, however, insulating sample. Our results, thus, are
not in agreement with a recent observation of a weak ferromagnetism in metallic
Mn doped SrTiO_3 system.Comment: 10 pages and 4 figure
A low-order decomposition of turbulent channel flow via resolvent analysis and convex optimization
We combine resolvent-mode decomposition with techniques from convex
optimization to optimally approximate velocity spectra in a turbulent channel.
The velocity is expressed as a weighted sum of resolvent modes that are
dynamically significant, non-empirical, and scalable with Reynolds number. To
optimally represent DNS data at friction Reynolds number , we determine
the weights of resolvent modes as the solution of a convex optimization
problem. Using only modes per wall-parallel wavenumber pair and temporal
frequency, we obtain close agreement with DNS-spectra, reducing the wall-normal
and temporal resolutions used in the simulation by three orders of magnitude
Aortic arch tortuosity with PHACE syndrome : a rare case scenario
PHACE syndrome is a rare neurocutaneous disorder characterised by an association of infantile haemangiomas with structural anomalies of brain, cerebral vasculature, eye, aorta and chest wall.1 Coarctation of aorta (COA) is most the common cardiac anomaly reported in PHACE syndrome. COA or interrupted aortic arch in PHACE is unique and complex both in location and character compared to the typical coarctation anatomy. Arterial tortuosity of the cerebral vasculature has been well described in literature in PHACE syndrome. We present a rare case of tortuous aortic arch continuing as descending aorta in an infant with PHACE syndrome.peer-reviewe
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