1,721,078 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
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
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Direct Measurement of Ozone Response to Emissions Perturbations in California
Full text linkLack of recent progress in reducing ground-level ozone (O3) concentrations to comply with health-based standards in California has motivated a reanalysis of emissions control strategies. Effective O3 control strategies account for the O3 sensitivity of its two primary precursors: volatile organic compounds (VOCs) and nitrogen oxides (NOx=NO+NO2), and then target the anthropogenic sources that emit the limiting precursor. In this dissertation, we developed a transportable smog chamber system to directly measure the response of O3 to perturbations in precursor NOx and VOCs under ambient atmosphere in the field. The chamber measurements were combined with field measurements, statistical analysis and box modeling to analyze the O3 photochemistry in California. Long-term measurements of O3 sensitivity at Sacramento, CA in 2020 observed seasonal trends that shifted from VOC-limited in winter towards NOx-limited in summer and back to VOC-limited in fall. These trends were confirmed to be widespread across California using satellite measurements of O3 sensitivity (TROPOMI HCHO/NO2). A comprehensive measurement of O3 sensitivity and VOCs were made at two sites (Pasadena and Redlands) in Southern California as part of the Re-Evaluating the Chemistry of Air Pollutants in California (RECAP-CA) field campaign (July ~ October, 2021). Redlands observed a similar seasonal trend as observed in Sacramento, where O3 sensitivity was VOC-limited in July and October and transitioned towards the NOx-limited in August and September, but Pasadena was stable in the VOC-limited regime. An observation-constrained box model was developed to calculate the O3 isopleth for Pasadena and Redlands. The isopleth suggests that an additional ~40% NOx reduction is needed to move 95% of the days with O3 concentrations above 70 ppb to the NOx-limited regime where further NOx reductions will result in lower O3 concentrations. VOC concentrations measured at Redlands were apportioned to nine source types using a Positive Matrix Factorization (PMF) model. The observation-constrained model was then configured with a tagging technique to quantify the VOC factor contributions to O3 formation. Biogenic VOCs (BVOCs) made the largest contribution (26.6%) to O3 formation in Redlands, followed by traffic VOCs (21.2%), Volatile chemical products (VCPs) (19%), and plant decomposition (14.9%). High O3 episodes were not driven by increased VOC emissions from any single source, but rather were associated with stagnation events. This implies that VOC controls optimized to reduce O3 concentrations would look similar in both the NOx-limited and VOC-limited regimes
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
Air Pollution Environmental Justice Analysis in California using Advanced Chemical Transport Modeling Systems
Full text linkAir pollution exposure is associated with increased risk for multiple adverse health outcomes including neurological disorders, asthma, diabetes, ischemic heart disease, and death. Race/ethnicity and income are predictors for air pollution exposure across most cities in the United States due to past discriminatory housing practices such as redlining. Future public policies must address this Environmental Justice issue so that all socio-economic groups have access to clean air.Predicting air pollution exposure disparities under different future scenarios is a difficult task because non-linear chemistry governs the formation of many pollutants. Historical relationships between pollutant concentrations and land-use or even pollutant concentrations and emissions may therefore not be useful when predicting future conditions. Chemical Transport Models (CTMs) predict air pollution concentrations based on fundamental chemical and physical equations that can accurately transition to future conditions. The research in this thesis explores how to refine CTM inputs and configuring CTM spatial resolution to accurately quantify air pollution exposure disparities in the present day and in the future.
In Chapter 2, ten major spatial surrogates describing the detailed locations of air pollution emissions in California are created/updated for the base year 2010 and future years from 2015 to 2040. The updated spatial surrogates generally improve CTM predictions for PM mass and EC concentrations in the Sacramento area (~10% for PM, ~3% for EC), the Bay Area (~3% for PM, ~1.5% for EC), and the region surrounding Los Angeles (~5% for PM, ~4% for EC). The updated spatial surrogates also improve predicted NOx concentrations in the core region of Los Angeles (~6%).
Chapter 3 explores the relationship between domain size and spatial resolution that affects predicted air pollution disparities in present day and future simulations when data support from measurements is not available. Overall WRF/Chem CTM accuracy improves approximately 9% as spatial resolution increases from 4 km to 250 m in present-day simulations. Exposure disparity results are consistent with previous findings: minorities experience higher exposure than White residents. Predicted exposure disparities are found to be a function of the model configuration. CTM configurations that use spatial resolution/domain size of 1 km / 103 km2 and 4 km / 104 km2 over Los Angeles can detect a 0.5 µg m-3 exposure difference with statistical power greater than 90%.
Chapter 4 conducts a comprehensive analysis of health co-benefits, racial disparities, and source / composition in air pollution exposure under six future energy scenarios and four future meteorology scenarios in California for future year 2050. Deeper reductions in the carbon intensity of energy sources progressively are found to reduce exposure to PM2.5 mass and PM0.1 mass for all California residents. The three energy scenarios that achieve an ~80% reduction in GHG emissions relative to 1990 levels simultaneously produce the greatest reduction in PM exposure for all California residents and the greatest reduction in the racial disparity of that exposure. The EJ assessment shows that adoption of low-carbon energy sources in the year 2050 reduces the race/ethnicity disparity in air pollution exposure in California by as much as 20% for PM2.5 mass and by as much as 40% for PM0.1 mass.
Future studies should apply the methods developed in this thesis to other locations across the United States in order to better understand how future policies such as a transition to low carbon energy can help to reduce air pollution exposure disparities by race/ethnicity
Author-wise bibliometric analysis based on entropy.
No full textAuthor-wise bibliometric analysis based on entropy.</p
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