1,696 research outputs found

    Urban wind energy conversion: the potential of ducted turbines

    Get PDF
    The prospects for urban wind power are discussed. A roof-mounted ducted wind turbine, which uses pressure differentials created by wind flow around a building, is proposed as an alternative to more conventional approaches. Outcomes from tests at model and prototype scale are described, and a simple mathematical model is presented. Predictions from the latter suggest that a ducted turbine can produce very high specific power outputs, going some way to offsetting its directional sensitivity. Further predictions using climate files are made to assess annual energy output and seasonal variations, with a conventional small wind turbine and a photovoltaic panel as comparators. It is concluded that ducted turbines have significant potential for retro-fitting to existing buildings, and have clear advantages where visual impact and safety are matters of concern

    Multipath Parameter Estimation from OFDM Signals in Mobile Channels

    Full text link
    We study multipath parameter estimation from orthogonal frequency division multiplex signals transmitted over doubly dispersive mobile radio channels. We are interested in cases where the transmission is long enough to suffer time selectivity, but short enough such that the time variation can be accurately modeled as depending only on per-tap linear phase variations due to Doppler effects. We therefore concentrate on the estimation of the complex gain, delay and Doppler offset of each tap of the multipath channel impulse response. We show that the frequency domain channel coefficients for an entire packet can be expressed as the superimposition of two-dimensional complex sinusoids. The maximum likelihood estimate requires solution of a multidimensional non-linear least squares problem, which is computationally infeasible in practice. We therefore propose a low complexity suboptimal solution based on iterative successive and parallel cancellation. First, initial delay/Doppler estimates are obtained via successive cancellation. These estimates are then refined using an iterative parallel cancellation procedure. We demonstrate via Monte Carlo simulations that the root mean squared error statistics of our estimator are very close to the Cramer-Rao lower bound of a single two-dimensional sinusoid in Gaussian noise.Comment: Submitted to IEEE Transactions on Wireless Communications (26 pages, 9 figures and 3 tables

    Overcoming isolation in distance learning: Building a learning community through time and space

    Get PDF
    The rise in popularity of distance education programmes, taught through web-based media, belies the difficulty in preparing, delivering and studying on such programmes. Preparing and providing quality material and a rich learning experience are key challenges. The physical and temporal separation of tutor and student, and between students themselves, can lead to feelings of isolation. The lack of interaction and discussion between students on non-cohort based courses lessens the richness of the learning experience and omits a significant element of the constructivist approach to learning. In order to provide maximum flexibility for students to study at a time, pace and subject issue of their choosing, the University of the West of England’s (UWE) MA Spatial Planning programme is delivered entirely online at a distance and asynchronously.This research investigates this pedagogic problem through examining the experiences of distance learning students at UWE, exploring issues and barriers to collaborative study, and exploring student isolation. Recommendations are generated for building a learning community on a non-cohort asynchronous programme of study. These include: providing service level agreements to clarify expectations; designating ‘staging points’ to encourage and motivate; developing student generated content as footprints ‘buried’ in the material; humanising the material; and introducing mechanisms to provide students with their peer’s thoughts/views on course material

    Overcoming isolation in distance learning: Building a learning community through time, space and sector

    Get PDF
    The rise in popularity of distance education programmes, taught through web-based media, belies the difficulty in preparing, delivering and studying on such programmes. Preparing and providing quality material and a rich learning experience are key challenges. The physical and temporal separation of tutor and student, and between students themselves, can lead to feelings of isolation. The lack of interaction and discussion between students on non-cohort based courses lessens the richness of the learning experience and omits a significant element of the constructivist approach to learning. In order to provide maximum flexibility for students to study at a time, pace and subject issue of their choosing, the University of the West of England’s (UWE) MA Spatial Planning programme is delivered entirely online at a distance and asynchronously.This research investigates this pedagogic problem through examining the experiences of distance learning students at UWE, exploring issues and barriers to collaborative study, and exploring student isolation. Recommendations are generated for building a learning community on a non-cohort asynchronous programme of study. These include: providing service level agreements to clarify expectations; designating ‘staging points’ to encourage and motivate; developing student generated content as footprints ‘buried’ in the material; humanising the material; and introducing mechanisms to provide students with their peer’s thoughts/views on course material

    Spatio-temporal influence of tundra snow properties on Ku-band (17.2 GHz) backscatter

    Get PDF
    During the 2010/11 boreal winter, a distributed set of backscatter measurements was collected using a ground-based Ku-band (17.2 GHz) scatterometer system at 26 open tundra sites. A standard snow-sampling procedure was completed after each scan to evaluate local variability in snow layering, depth, density and water equivalent (SWE) within the scatterometer field of view. The shallow depths and large basal depth hoar encountered presented an opportunity to evaluate backscatter under a set of previously untested conditions. Strong Ku-band response was found with increasing snow depth and snow water equivalent (SWE). In particular, co-polarized vertical backscatter increased by 0.82 dB for every 1 cm increase in SWE (R2 = 0.62). While the result indicated strong potential for Ku-band retrieval of shallow snow properties, it did not characterize the influence of sub-scan variability. An enhanced snow-sampling procedure was introduced to generate detailed characterizations of stratigraphy within the scatterometer field of view using near-infrared photography along the length of a 5m trench. Changes in snow properties along the trench were used to discuss variations in the collocated backscatter response. A pair of contrasting observation sites was used to highlight uncertainties in backscatter response related to short length scale spatial variability in the observed tundra environment

    Adaptive Golf Device

    Get PDF
    Our primary objective was to design a golf device that enables its user, who has limited leg movement and control, to be able to produce a balanced golf swing. Ultimately, the device maximizes the golfer\u27s independence, and increases the accuracy of and power behind each shot. Specifically, the device was designed around the needs and requirements of Dr. Joshua Pate, Professor of Adapted Recreation at James Madison University. Dr. Pate has cerebral palsy limiting his lower body mobility and making it difficult for him to produce a balanced golf swing

    A real time, longitudinal, qualitative evaluation of the first two cohorts to participate in the Queen’s Nurse Development Programme.

    Get PDF
    Background: The Queens Nurse Development Programme (QNDP) has been delivered to community nurses in Scotland since 2017, born out of a commitment to reintroduce the Queen’s Nurse title in Scotland after 50 years. The aim of the QNDP was to connect individuals with a shared passion for delivering high - quality nursing throughout Scotland’s communities, to create a safe space where participants could develop and grow on a personal level to become change makers, to inspire others, help those most in need and champion community nursing. As such, the participants selected were employed in a wide-range of diverse roles, from throughout Scotland. The programme takes place over a nine-months, during which participants engaged with a varied programme involving residential workshops, where they experienced a range of creative and contemplative awareness based change practices, the development of a practice issue, and individual coaching. This report presents an independent evaluation of the QNDP based on the first two cohorts of participants to engage with the programme (2017 & 2018). Evaluating the QNDP is important to optimise the programme for subsequent cohorts of Queen’s nurses and to inform the transferability of the programme to other professions and contexts. Methods: A comprehensive, longitudinal, qualitative evaluation, where data was collected at various time points, using interviews, focus groups and a ‘member-checking’ event with all 41 QNDP participants (20 fromcohort 1 and 21 fromcohort 2), as well as 12 community nursing managers and the 3 QNDP facilitators. The purpose was to uncover and explore perceptions and experiences of the QNDP: what was learned; how this was implemented into everyday practice; as well as the impacts and sustainability of changes. The data was analysed using Braun and Clarke’s six-point framework of analysis; familiarisation, coding, generating themes, reviewing themes, defining and naming themes and writing up (Clarke et al., 2015). Double coding and independent analysis ensured trustworthy, rigorous and valid findings. Summary and Conclusions: Participants were overwhelmingly positive about the programme, and appreciated its design, facilitation, approach and methods utilised, as well as the resulting impacts and outcomes. Engaging with the QNDP led to an unexpected ‘journey of self-discovery and transformation’, with notable self-development, growth and positive change. Essentially, the programme enabled participants to see through a new lens, re-position themselves and embody new (person-centred) ways of being and doing, which transcended both their personal and professional lives as community nurses, colleagues, ‘leaders’, service providers, networkers, family members and friends. The participants perceptions of this work and learning was that as it was personal, changing their thinking and identity and therefore, the impact of the programme and the personal and professional transformation and changes introduced were perceived to be sustainable for the rest of their professional life and beyond. The programme facilitated the building of close bonds with their peers which enabled them to confidently share problems and challenges, reinforce their learnings and new thinking, and engage them in a journey of transformation. As such, a community of practice has been created within and across the cohorts which has the potential to become a social movement as intended by QNIS. The programme also equipped them with novel, creative approaches, skills and tools that they were able to share with colleagues, friends and family. Thus, the programme achieved a key aim of connecting individuals and equipping QNDP participants with a range of new skills. The findings of this evaluation and the QNDP are likely to be transferable to other health and social care professionals and beyond the Scottish context

    Concert recording 2015-03-22

    Get PDF
    [Track 01]. Walking street ; [Track 02]. Pan man / Steve Erquiaga -- [Track 03]. Cherokee / Ray Noble -- [Track 04]. Wave / Antonio Caros Jobim -- [Track 05]. Alone together / Arthur Schwartz -- [Track 06]. Up jumped spring / Freddie Hubbard -- [Track 07]. Blues for Alice / Charlie Bird Parker -- [Track 08]. Stella by starlight / Victor Young ; solo arranged by Jared Guinn
    • …
    corecore