1,720,983 research outputs found
The impact of soils, weather and trees on water infrastructure failure.
Get PDFThe uninterrupted supply and reliable distribution of drinking water is fundamental
in a modern society; however, water pipelines are subject to a range of
operational and environmental factors which can lead to asset failure. For the
privatised water-sector in the UK, utility companies are moving towards the
deployment of statistical models for proactive asset management. For some
companies, statistical models have facilitated the migration away from static
annual burst targets, to targets which are dynamic and adjusted to observed
environmental conditions. There is an increasing need for the development of
accurate pipeline failure prediction models to support asset management and
regulatory reporting. This thesis evaluates several quantitative measures to
improve current methods of pipeline failure prediction. The aim of this thesis is to
establish the impact of soils, weather and trees on water infrastructure failure and
to develop a series of material-specific drinking water pipeline failure models for
an entire distribution network.
A quantitative assessment investigating the impact of data cleaning on the
attained model error of a series of previously developed models was conducted.
Material-specific variable selection and step-wise modelling approaches was
used to construct a series of improved statistical models, which have an
increased representation of the environmental factors leading to pipeline failure.
A detailed national tree inventory was investigated for its use in enhancing
pipeline failure predictions and for calculating failure rates of different pipe
materials under varying soil shrink swell and tree density conditions. The value in
creating separate winter and summer pipeline failure models was also evaluated,
to increase representation of the highly seasonal nature of pipeline failure. Finally,
a satellite approach was used to generate soil-related land surface deformation
measurements across a regional area was investigated. The result is a series of
enhanced statistical models for the prediction of water pipeline failure and a
greater understanding into the environmental drivers leading to asset failure.PhD in Water, including Desig
Soil-related geohazard assessment for climate-resilient UK infrastructure
Get PDFUK (United Kingdom) infrastructure networks are fundamental for maintaining
societal and economic wellbeing. With infrastructure assets predominantly
founded in the soil layer (< 1.5m below ground level) they are subject to a range
of soil-related geohazards. A literature review identified that geohazards
including, clay-related subsidence, sand erosion and soil corrosivity have
exerted significant impacts on UK infrastructure to date; often resulting in both
long-term degradation and ultimately structural failure of particular assets.
Climate change projections suggest that these geohazards, which are
themselves driven by antecedent weather conditions, are likely to increase in
magnitude and frequency for certain areas of the UK through the 21st century.
Despite this, the incorporation of climate data into geohazard models has
seldom been undertaken and never on a national scale for the UK.
Furthermore, geohazard risk assessment in UK infrastructure planning policy is
fragmented and knowledge is often lacking due to the complexity of modelling
chronic hazards in comparison to acute phenomenon such as flooding. With HM
Government's recent announcement of £50 million planned infrastructure
investment and capital projects, the place of climate resilient infrastructure is
increasingly pertinent. The aim of this thesis is therefore to establish whether
soil-related geohazard assessments have a role in ensuring climate-resilient UK
infrastructure.
Soil moisture projections were calculated using probabilistic weather variables
derived from a high-resolution version of the UKCP09 (UK Climate Projections2009) weather generator. These were then incorporated into a geohazard
model to predict Great Britain's (GB) subsidence hazard for the future scenarios
of 2030 (2020-2049) and 2050 (2040-2069) as well as the existing climatic
baseline (1961-1990). Results suggest that GB is likely to be subject to
increased clay-related subsidence in future, particularly in the south east of
England.
This thesis has added to scientific understanding through the creation of a
novel, national-scale assessment of clay subsidence risk, with future
assessments undertaken to 2050. This has been used to help create a soil-
informed maintenance strategy for improving the climate resilience of UK local
roads, based on an extended case study utilising road condition data for the
county of Lincolnshire, UK. Finally, a methodological framework has been
created, providing a range of infrastructure climate adaptation stakeholders with
a method for incorporating geohazard assessments, informed by climate
change projections, into asset management planning and design of new
infrastructure.
This research also highlights how infrastructure networks are becoming
increasingly interconnected, particularly geographically, and therefore even
minor environmental shocks arising from soil-related geohazards can cause
significant cascading failures of multiple infrastructure networks. A local
infrastructure hotspot analysis methodology and case-study is provided
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Get PDF“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Get PDFWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Dispelling the Myths Behind First-author Citation Counts
Get PDFWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
koamabayili/VECTRON-author-checklist: VECTRON author checklist
No full textWe have done our best to complete the author checklist relating to the use of animals in the hut study. Note that the objective for the hut study was to evaluate the IRS treatment applications for residual efficacy against Anopheles mosquitoes, including the local An. coluzzii mosquito population. Cows were only used to attract mosquitoes into the huts and no tests were carried out directly on the cows. The author checklist is intended for use with studies where experiments are carried out on animals, which is why we have had such difficulty in completing this for the hut study, as many of the questions do not relate to how the cows were used
Author-wise bibliometric analysis based on entropy.
No full textAuthor-wise bibliometric analysis based on entropy.</p
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