1,720,956 research outputs found
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
Assessing Ecosystem Service Benefits of Improved Soil Management Practices at the Field and Watershed Scales
No full textPoor soil management limits the soil functions of water infiltration and storage and enhances water and soil losses. Amidst recurring droughts and declining water availability, improved soil management practices such as no-tillage (NT) and cover crops (CC) could play a critical role in improving soil ecosystem services while sustaining agriculture and mitigating negative impacts of climate change. The goal of this Dissertation research was to quantify the potential soil and water conservation benefits of adopting improved soil management practices at the field and watershed scales using hydrologic models and Unmanned Aerial System (UAS)- based measurements in the Texas Blackland Prairies and Rolling Plains regions. This was achieved by using the Precision Agricultural Landscape Modeling System (PALMS) and Agricultural Policy / Environmental eXtender (APEX) models and developing regression models based on UAS data.
PALMS field-scale simulations indicated a substantial increase in plant available water in the soil under NT over conventional tillage (CT), especially during dry years. At the watershed scale, APEX was trained to follow the Curve Number-Precipitation relationship, which was developed based on rainfall-runoff measurements from CT and NT fields at Riesel, TX. Changing management on all croplands of the Bushy Creek Watershed from CT to NT resulted in a 25% and 57% reduction in average annual runoff and sediment loss, respectively at the watershed outlet, most of which occurred during the months with high intensity rainfall. Simulated average reduction in annual runoff and sediment loss with NT management under projected future climate ranged between 27���33% and 55���59%, respectively, compared to CT management under historic climate.
The effects of CCs and tillage management on crop growth were assessed using the UAS imageries collected during cotton growing season from a long-term CC/NT experimental field at Chillicothe, TX. Vegetation indices from plant pixels were found to be highly effective in distinguishing between the effects of different soil management practices. The UAS imageries were also found to be useful for predicting soil water content by developing regression models. Overall, this research revealed several benefits of improved soil management practices at field and watershed scales under current and projected future climatic conditions
Seasonal Variation of Infiltration Rates Through Pond Bed in a Managed Aquifer Recharge System
Get PDFManaged Aquifer Recharge (MAR) has become a powerful tool for increasing water supplies around the world. The Torreele Waste Water Treatment Plant (TWWTP) in Belgium uses MAR to recharge the aquifer with treated wastewater in order to sustain the potable water supply on the Belgian coast. The treated water from the TWWTP is transported to two infiltration ponds where it is recharged into a 30m deep phreatic aquifer by the natural process of infiltration under gravity. One of the challenges of the MAR facility is the reduced infiltration rates during the winter season when pond water temperatures vary from 4 °C to 10 °C. The infiltration capacity is approximately 50.5 to 100 % higher in summer as compared to that in winter.
Several factors including pumping rate around ponds, natural recharge, tidal influences of the North Sea and pond-water temperature were identified as potential causes for the variation of recharge rate. This study involves the identification of the predominant factor influencing the rate of infiltration through the pond bed. Correlation statistics and linear regression analysis have been used to determine the sensitivity of infiltration rate to the aforementioned factors. Results showed that water temperature has the maximum impact on infiltration rate. Cyclic variations in water viscosity, occurring as a result of seasonal temperature changes, influence the saturated hydraulic conductivity of the pond bed. A lower infiltration rate through the pond bed is observed during the winter months due to increased viscosity, which results in a decline in saturated hydraulic conductivity of the sandy soil. Temporal changes in the vertical hydraulic gradient is another factor that could alter infiltration rate as the pumping rate around the pond causes fluctuations in the groundwater level.
Two groundwater flow models have been developed in visual MODFLOW to simulate the water movement under the pond bed. The response of groundwater levels to artificial recharge from the pond under hypothetical scenarios for summer and winter months are assessed to obtain the differences in flux and track the effects of variation of hydraulic conductivity during the two seasons. It is observed from the models that higher leakance through infiltration pond bed in summer corresponds to the reduced heads in the monitoring wells and lower leakance corresponds to the higher heads, hence proving the impact of temperature influenced hydraulic conductivity in variation of infiltration rate
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
- …
