5,367 research outputs found

    L- and K-band LMSS propagation measurements using MARECS-B, OLYMPUS, and ACTS

    Get PDF
    L-band measurements of land mobile satellite systems (LMSS) propagation effects were last made at the end of 1988, but some voids were left in the database, making modeling of low elevation roadside tree shadowing and multipath reflections difficult for some path geometries. Transmission of a pilot tone from MARECS-B at 55 deg West during Sep. and Dec. 1991 gave an opportunity to fill the gaps in the experimental results. Two campaigns during which fade data were obtained at elevation angles from 7 deg to 40 deg are described. Below 15 deg, specular terrain reflections in a non-shadowing, hilly environment were observed to introduce significant fading. Although the reflecting surface was at a distance of up to several km, it is shown that the reflected signals are delayed by less than 1 microsec. Mobile measurements were also attempted receiving the 20 GHz Olympus beacon, but antenna pointing problems restricted first results to straight-line driving

    Study of a signal processor employing a synthetic phase isolator

    Get PDF
    Evaluation of signal data processor employing synthetic phase isolator techniqu

    A feasibility study of signal processing to improve antenna gain Final report

    Get PDF
    Feasibility of signal processor with phase isolator for adaptive antenna arra

    Pre service primary teachers’ approaches to mathematical generalisation

    Get PDF
    In our teaching with primary pre-service teachers (PSTs), each of us includes generalising tasks in the context of mathematical reasoning. We set out to explore the value of such activity from the perspective of PSTs and their approaches to generalisation. In this paper, we focus on one PST’s mathematical reasoning when working on the ‘flower beds’ problem. We analyse the ways in which this PST attends to: looking for a relationship; seeing structure within a single figure in a sequence; and seeing sameness and difference between figures in a sequence. We consider what motivates shifts in attention, we reflect on the significance of students’ prior experience, and of student collaboration in our teaching sessions

    A framework for exploring gender equality outcomes from WASH programmes

    Full text link
    This paper aims to assist practitioners and researchers in planning, identifying, and documenting gender outcomes associated with water, sanitation, and hygiene (WASH) programmes by proposing a conceptual framework for classifying gender equality changes. Gender outcomes that have been attributed to WASH initiatives encompass those directly related to improved services as well as outcomes that move into areas of relationships, power, and status. There is a growing body of literature identifying WASH-related gender outcomes; however the types of outcomes described vary considerably and further work is needed to inform a comprehensive picture of WASH and gender links. The framework proposed in this paper is based on a synthesis of outcomes reported in WASH literature to date, empirical research in Fiji and Vanuatu, and insights from gender and development literature. It is hoped that the framework will support practitioners to engage with the inherent complexity of gender inquiry, contributing to sector knowledge about the potential for WASH initiatives to advance gender equality. © Practical Action Publishing, 2013

    Biological Records Centre Annual Report 2005-2006

    Get PDF
    The period covered by this report is the first year of a new six-year partnership between CEH and JNCC. For this period, there is increased emphasis on targeted survey, on analysis and interpretation and on communications and outreach. These activities were always part of BRC’s work, but they have been given greater prominence as a result of rapid developments in information technology. Data are increasingly reaching BRC in electronic form, so that the effort of data entry and collation is reduced. The data, collected by many volunteers and then collated and analysed at BRC, document the changing status and distribution of plants and animals in Britain. Distribution maps are published in atlases and are available via the internet through the NBN Gateway. The effects of change or loss of habitats, the influence of climate change and the consequences of changing water quality are all examples of the environmental factors that affect our biodiversity and which BRC aims to document and understand. The results are vital for developing environmental policies, to support conservation, and for fundamental ecological research. BRC is funded jointly by JNCC and NERC through a partnership based on a Memorandum of Agreement (MoA). The partnership started in 1973 when the Nature Conservancy was divided to form the successor bodies Nature Conservancy Council (NCC) and Institute of Terrestrial Ecology (ITE). NCC was in turn divided further to form JNCC and three Country Agencies, while ITE was merged with other NERC units to form CEH. Through all these changes, the partnership has been maintained. A six-year memorandum of agreement ended on 31 January 2005 (Hill et al. 2005). The present report covers the first full year, 2005-6, of the new agreement for 2005-2010. Rapid progress in information technology continues to be highly beneficial for BRC, whose data are increasingly used by the UK country conservation agencies, environmental consultants, NGOs, research workers, policy makers and volunteers. It is gratifying to know that, through our ability to display data on the National Biodiversity Network (NBN) Gateway, some of our data suppliers now have immediate access to their own data in a convenient form. The year 2005-6 has been one of steady progress, with new datasets added to BRC, substantial additions to existing data, and improved communication with the NBN Gateway. The most high profile activity of the year has been the Harlequin Ladybird Survey, which has enabled us to observe the early stages of colonization by a mobile insect in greater detail than has been possible in any previous case
    • 

    corecore