1,720,968 research outputs found
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe 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
Full text link“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
Full text linkWe 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
Spatiotemporal Climate Variability over Senegal and its Relationships with Global Climate
No full textClimate variability over Senegal and its relationships with global climate is examined for the period 1971-1998. Monthly observed rainfall for 20 stations over Senegal, monthly mean temperature for 12 stations and monthly average CMAP data were averaged for the months of June July, August and September, to generate seasonal rainfall totals for the wet season and climate indices averaged over the study period. The monthly SST data is the NOAA Extended Reconstructed SST data (ERSST) provided by the NOAA-CIRES Climate Diagnostics Center in Boulder, Colorado.
The monthly, seasonal and annual temperature and precipitation distributions are mapped analyzed using ArcGIS Spatial Analyst. Rainfall distribution over Senegal is dominated by a N-S gradient, and temperature distribution by an E-W gradient.
The mapping of the coefficient of variation for all stations reveals that for both rainfall and the number of rainy days, June is the month that exhibits the greater variability, especially in the West and North of the country. As regard to temperatures, the months from January to April are accountable for most of the variability, especially in the sub-arid areas of the North and Northwest.
Trends in precipitation and temperature are estimated using a linear regression analysis and interpolation maps for the slopes. Areas of positive slopes are limited for rainfall (Northeast and Southwest of Senegal), but important and statistically significant for temperature throughout the country.
To investigate the climate variability over Senegal two EOF analyses are performed: for 1971-1998 using observations, and for 1979-7998 using additional CMAP data. The first analysis reveals a strong domination of the first EOF mode for rainfall over Senegal. The corresponding time series mostly fluctuates on a high frequency mode. Its correlations with Atlantic and Pacific SST don't show a strong relationship leading to predictability. However, the second mode for September is well correlated with North Atlantic SST. Despite modest coefficients, the best results are found with Pacific Ocean SST (lag correlation).
The second EOF analysis (1979-1998) includes CMAP data and is conducted over Senegal and West Africa. The first West African mode agrees strongly with Lamb's rainfall index. One of our major findings is that EOF2 for West Africa is well correlated with EOF1 for Senegal rainfall. This relationship is supported by the projection of NCEP winds on EOF2 mode, and the grid-point correlation between the time series of EOF2 over West Africa and the Atlantic SST. Series for CMAP rainfall over Senegal show good correlation with the South Atlantic SST. Good coefficients are observed during the pre-wet season (January through May) and may offer some predictability for the rainy season. In the Pacific Ocean, the greatest coefficients (up to -0.72) are observed during the April-July period, which can provide hints for the coming rainy season.
The different results obtained in the two analyses suggest an evolution in the relationship between SST fields and Senegal or West African rainfall. The correlations show that the relationships between the South Atlantic and Senegal or West Africa were stronger in the 1979-1988-period, especially for CMAP rainfall over Senegal and West Africa. The CMAP data is robust and suitable for analyses over West Africa. Based on this liability, it has been possible to use CMAP data in a second EOF analysis, as a validation for the first analysis only based on observed precipitation.
Given the specificity of the coastal West Africa, traditional indices used by policy makers and end users for the whole Sahel-Sudan region will not work for Senegal
Dispelling the Myths Behind First-author Citation Counts
Full text linkWe 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
Impacts of land surface properties on temperature trends over the United States: Assessment using the US historical climate network and North American regional reanalysis datasets
No full textTemperature trends result from natural and anthropogenic factors. The latter was first seen as the result of radiative forcings, mainly the increasing concentrations of greenhouse gases. However, the increasing evidence that some non-radiative forcings such as land use/land cover (LULC) change may also be major factors contributing to climate change has prompted the National Research Council (NRC, 2005) to recommend the broadening of the climate change issue to include LULC processes as an important climate forcing. In addition, at the station level, increasing attention has been given to non-climatic biases that affect temperature records due to changes of the local environment at the vicinity of the station, changes in instrumentation and/or observations practices. This study (i) uses comparisons between in-situ observations and reanalysis datasets as an independent method to estimate temperature trends and variability and evaluate adjustments made to temperature records to correct non-climatic biases, (ii) uses the Observation Minus Reanalysis (OMR) method to investigate the impacts of sensitivity of surface temperature trends to LULC change over the conterminous United States and (iii) compares temperature and equivalent temperature (which is a variable that combines both temperature and moisture) and analyzes their respective correlation to vegetation properties. The comparison between the reanalysis and in-situ temperature observations shows that the reanalysis faithfully captures the intraseasonal and interannual variability of the station observations and also provides valuable information about the effects of individual station location (well or poorly sited) on temperature observations. Moreover, the comparison between surface observations and the North American Regional Reanalysis (NARR) using the Mean Square Difference (MSD) method is efficient in detecting LULC changes that took place at the vicinity of stations or changes related to observation practices, and in evaluating the impacts of adjustments performed on raw observations. OMR trends were found to be sensitive to land cover types and results indicate that land use conversion often results in more warming than cooling. Overall, our results confirm the robustness of the OMR method for capturing patterns of LULC changes at local and regional scales. The comparison between temperature and equivalent temperature demonstrates that atmospheric heat content may help to quantify the differences between surface and tropospheric trends, and hence the impact of land cover types on the surface temperature changes. Moreover, equivalent temperature is more correlated to biomass increase, vegetation transpiration and other surface moisture characteristics. Overall, this study suggests that in addition to considering the greenhouse gases-driven radiative forcings, multi-decadal and longer climate models simulations must further include LULC changes
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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