11,834 research outputs found

    SLIP4EX- a program for routine slope stability analysis to include the effects of vegetation, reinforcement and hydrological changes

    Get PDF
    SLIP4EX is a straightforward computer program developed in connection with the EU funded ECOSLOPES project for routine stability analysis and the assessment of the contribution of vegetation to slope stability. The slope section is drawn up and dimensions and parameters are fed in to the Microsoft Excel based program for stability calculations and comparisons of Factors of Safety using different methods of analysis (Bishop, Janbu, Fellenius, Simple, Greenwood). The background and assumptions involved in the derivation of each of the methods is briefly described. The simplicity of the program enables the user to understand the nature of the analysis, explore the parameter assumptions made and compare the different methods of analysis. Soil reinforcement by geosynthetic layers or anchors, and vegetation effects of enhanced cohesion, changed water pressures, mass of vegetation, wind forces and root reinforcement forces are readily included in the analysis. The program is freely available on request from the author

    Potential environmental impact of tidal energy extraction in the Pentland Firth at large spatial scales : results of a biogeochemical model

    Get PDF
    A model study was carried out of the potential large-scale (> 100 km) effects of marine renewable tidal energy generation in the Pentland Firth, using the 3-D hydrodynamics–biogeochemistry model GETM-ERSEM-BFM. A realistic 800 MW scenario and a high-impact scenario with massive expansion of tidal energy extraction to 8 GW scenario were considered. The realistic 800 MW scenario suggested minor effects on the tides, and undetectable effects on the biogeochemistry. The massive-expansion 8 GW scenario suggested effects would be observed over hundreds of kilometres away with changes of up to 10 % in tidal and ecosystem variables, in particular in a broad area in the vicinity of the Wash. There, waters became less turbid, and primary production increased with associated increases in faunal ecosystem variables. Moreover, a one-off increase in carbon storage in the sea bed was detected. Although these first results suggest positive environmental effects, further investigation is recommended of (i) the residual circulation in the vicinity of the Pentland Firth and effects on larval dispersal using a higher-resolution model and (ii) ecosystem effects with (future) state-of-the-art models if energy extraction substantially beyond 1 GW is planned

    POKES, PRODS, AND PUSHES: INFORMATION AVAILABILITY AND DECISION MAKING IN AMBIGUOUS ENVIRONMENTS

    Get PDF
    In this dissertation I investigate how changes in the availability of information influences decision making in inherently ambiguous environments. As the Internet has not only fostered connectivity, but also catalyzed information generation on an unprecedented scale, my objective is to revisit the concept of information availability and salience in the digital age. I conduct my empirical analysis in the contexts of entrepreneurship and healthcare, which are significant both theoretically as well as in terms of economic and public welfare. In essay one, I examine how rising perceptions of fashion, viz., increased media coverage and herding, influence the willingness of venture capitalists to fund non-co-located entrepreneurs. This essay contributes to extant theory on entrepreneur-VC co-location by identifying the effect that social trends, as opposed to factors which are native only to the focal entrepreneur, can have on the willingness to venture capitalists to fund non-co-located entrepreneurs. In essay two, I explore the interplay between the broadcast and social media, as well as the ability of these media to incentivize firm formation on the part of nascent entrepreneurs. Applying the lens of agenda setting theory I demonstrate that the social media will moderate the impact of the broadcast media when entrepreneurs and financiers seek to found and fund new ventures. This study augments existing literature by considering not only the intensity of non-novel information, but also how participation will impact decision making. The third essay investigates a persistent puzzle in the medical literature: how different physicians react to medical guideline release (i.e. the release of new and novel information) which call into question the efficacy of long standing treatment options. Situating this essay within two theoretical tensions in the literature, the trade-off between agility and routines and the debate between costless and costly information assimilation, I find that while physicians are discerning in their reaction to new information their reactions are not quick, creating significant public welfare deficits. Moreover, I find that physician characteristics, such as tenure, board certification, and freelancer status, significantly moderate physician response to new guidelines. Taken together these essays contribute to the literature on Information Systems and Strategic Management by augmenting understanding of the construct of information availability, and how it affects decision makers in ambiguous environments

    The influence of ethnic group composition on focus group discussions

    Get PDF
    BACKGROUND: Focus groups are commonly used to explore participants' experiences in health and social care research. Although it is suggested that having demographically homogenous groups may help put participants at ease, the evidence is sparse.The aims of the paper are to: explore the impact of relative ethnic homogeneity and heterogeneity of focus group participants on the group discussions; improve understanding of homogeneity and heterogeneity in focus groups; suggest ways to operationalise concepts such as being 'more comfortable' with other focus group participants. METHOD: Digitally recorded focus groups were undertaken with family carers of stroke survivors and were later transcribed and analysed using framework analysis. Groups were designated as more or less ethnically homogenous. More homogenous groups included, for example, only White British or Asian Indian participants whilst more heterogeneous groups comprised a mixture of, for example, Asian, White British and Black Caribbean participants. RESULTS: Forty-one carers participated in seven focus groups. Analysis revealed differences in discussions around ethnicity between the more or less ethnically homogenous groups. For example, participants in more ethnically homogenous focus groups were more likely to say ethnicity might influence perceptions of social care services. On the other hand, more heterogeneous groups emphasised similarity in carers' experiences, irrespective of ethnicity. Participants in the more homogenous groups were also more likely to make potentially controversial comments relating to ethnic differences. Additionally they appeared to be more at ease with each other discussing the topic. For example, they spontaneously mentioned ethnic differences earlier in these groups.In contrast, analysis of topics not specifically related to ethnicity, such as the difficult experiences of being a carer, produced no discernible patterns when comparing more and less homogenous focus groups. CONCLUSION: Considerations around focus group participant demographic homogeneity and heterogeneity are complex and these terms may be most usefully applied only in relative terms.Data derived from more homogenous groups complement data from more heterogeneous groups providing different perspectives. Depending on the focus of the discussion, having characteristics in common, such as being a carer can override other differences
    • 

    corecore