1,720,955 research outputs found
Spatial and temporal trend analysis of temperature extremes in Tanzania
No full textThis study examines the effects of extreme temperature events, defined explicitly as the 98th percentile temperature for heat, in Tanzania from 1981 to 2023. The study utilises percentile analysis, z-score calculations, and trend mapping to highlight the prevalence of extreme temperatures. The z-score analysis examines the occurrence of extreme temperatures and their distribution in terms of frequency and space. It identified Tanzania’s mid-eastern and north-western regions as areas with a high concentration of extreme temperatures over the previous 43 years. The study analyses the length of extreme occurrences and reveals changing patterns. In 2020, the events were shorter, while in 2021 and 2022, they became longer-lasting, and there was a notable concentration of extended anomalies near the northern coastline. In 2023, the highest temperatures ever recorded were observed, with more than half of the regions seeing prolonged periods of extreme temperatures lasting for a week and significant deviations from the norm staying for four weeks or more. This was particularly notable in the southern regions of Lindi and Mtwara. The harmonic trend analysis of temperature shows an upward temperature trend noticeably in regions such as Arusha, Kilimanjaro, Kagera, Morogoro, Simiyu, and Shinyanga and is somewhat inconspicuous in most areas
Land use/cover changes and vulnerability to flooding in the harts catchment, South Africa
Get PDFThesis (M.Sc.(Environmental Science) North-West University, Mafikeng Campus, 2012The purpose of this study was to determine the hydrological impacts of land use/land cover
(LULC) change in the Harts River catchment from 1990 to 2010 using an integration of
remote sensing, Geographic Information System and statistical methods. Hydrological data of
rainfall and river discharge were statistically analysed to reveal the changes and trends from
1990 to 2010. Changes in year-to-year relationships between precipitation and discharge
suggested that discharge was relatively higher in the second half than in the first half of the
study period. In fact, a weak correlation of 0.39 was found between precipitation and river
discharge. The positive trend in discharge in the Harts River coincided with major changes in
land cover over the study area. The LULC changes showed a decrease of vegetation cover
from 758345 ha in 1990 to 736879ha in 2008, while barren land increased from 226670 ha in
1990 to 324322 ha in 2008 (an increase of 97652 ha). The coupIing of surface observations,
remote sensing, and statistical analysis demonstrated the impact of changes in LULC on peak
river discharge and hence flooding behaviour on the Harts River catchment.Master
Analysing the spatial pattern of road networks in Kimberley, South Africa
Get PDFThe increasing burden on South African road networks necessitates sustainable solutions that conclude their spatial configuration and arrangement. A deeper understanding of the existing road network’s spatial organisation is, therefore, required. This study evaluates the structural design of road networks in Kimberley, South Africa, using spatial network science and open-source OpenStreetMap data. Nonplanar-directed multigraphs for Kimberley are constructed to analyse the structural and morphological characteristics of the network. The study area was evaluated with several network-analysis methods such as completeness, degree of centrality, betweenness, closeness, and PageRank. The study found that Kimberley has a low degree of centrality of 0.00111. This indicates that the road network should be less congested because there are fewer vulnerable spots. Because of the availability of two-way streets, the total edge length in the Kimberley network is nearly double the total street length. There are 2.97 streets radiating from Kimberley nodes on average. This suggests that three-way intersections are prevalent in Kimberley. Centrality measures and analysing the effects in terms of accessibility to the commerce and services of the city show how the legacy of racial segregation, poverty, and isolation from social and economic opportunities impedes the places within Kimberley. Results from the study also indicate that the informal sections of Galeshewe are fine-grained in terms of road network, while Kimberley CBD and nearby districts have coarse grain roads. This pattern contributes to the relative overall low average street segment length (a proxy for block size) of 107 metres in Kimberley
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
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