1,720,954 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
Assesment of Equipment Performance Variables for Improved Management during Tillage Operations
Get PDFDeep tillage operations required to alleviate compaction layers in soils found especially in the southeast region of the United States remain to be one of the largest areas of energy and fuel expense for agricultural producers. Good farm managers look for more efficient fuel utilization techniques with improved productivity. The objectives of this research were to: 1) develop an in-field monitoring system to display and collect various real-time tractor and implement performance data; 2) collect and analyze tractor and implement performance data while varying different equipment operational variables during deep tillage operations; and 3) quantify fuel usage and cost savings for the implementation of site-specific equipment management strategies. Four different experiments were performed. A depth performance experiment investigated subsoiler draft and fuel consumption requirements for two different tillage depths (22.8 cm and 35.6 cm). The effects of tillage time rotation on energy requirements of three different
subsoilers were also studied. The third experiment evaluated the effects of speed on equipment performance and energy requirements between two different subsoilers. The final experiment investigated the response of three different tire pressures on equipment performance and was used to highlight the value of spatially collected equipment data.
Results from the depth performance experiment indicated that a 130% and 23% increase in draft and fuel consumption, respectively, occurred between the shallow and deeper tillage depths. Draft more than doubled over a 12.7 cm depth difference indicating tillage at shallower depths can save energy and fuel costs. The tillage rotation experiment resulted in increases in fuel consumption, draft and axle torque in the triennial year rotation compared to annual and biennial rotations. The implement speed experiment showed that the Kelley Manufacturing Company (KMC) subsoiler had a 115.0%, 7.1%, and 37.3% increase in fuel consumption, axle torque, and implement draft respectively from a slow to fast speed. A 105.0%, 2.3%, and 27.8% increase in fuel consumption, axle torque, and implement draft, respectively, resulted between slow and fast speeds for the Paratill™. The data from the tire pressure experiment showed a 4.6%, 69.0%, and 17.1% increase in fuel consumption, tire slip, and axle torque, respectively, between the low and high air pressure treatments. Spatially, field variables effected equipment performance data with 17% to 23% increases in fuel consumption depending on travel direction and terrain differences. In conclusion, these experiments differentiated equipment performance between some of the available modern tillage implements and operational variables to quantify fuel usage and potential cost savings for alternative methods of performing tillage operations
Cover Crop Management and Nutrient Type Effects on Collard and Cotton Growth
No full textProducing fresh vegetables and fiber, such as collards (Brassica oleracea L. var. viridis) and cotton (Gossypium herbaceum L.), in cover crop residue while minimizing soil disturbance can be helpful in lowering environmental impacts. Furthermore, using different types of fertilization, including poultry litter, for cotton can also promote soil health and manage input costs. Two experiments were performed to investigate 3 different residue management methods including rolled/crimped (Roll), mowed (Mow), and mowed + incorporated by tillage (MowIncorp) and their effects on a collard and cotton production system.
Collards were grown in both an iron clay pea (Vigna unguiculata L.) and pearl millet (Pennisetum glaucum L.) cover crop and results showed that cover crop type influenced collard productivity in the 2015, 2016, and 2017 seasons. Pearl millet produced more biomass (P=0.0013) with a three-year average of 8461 kg ha−1 compared to 6465 kg ha−1 for iron clay pea. Carbon sequestration was evident in both cropping systems with 10.5% (from 5.04 to 5.57 g C kg-1) and 8.1% (from 5.08 to 5.49 g C kg-1) increases in total soil carbon for pearl millet and iron clay pea, respectively, in the top 15 cm of soil over three seasons. Overall, collard yield in the iron clay pea cover crop produced more (P<0.0001) with a 3-year average of 7268 kg ha-1 compared to 4724 kg ha-1 for the pearl millet.
The cotton experiment investigated the residue management methods for a single rye cover crop and four different nutrient treatments for the 2022-2023 seasons. All nutrient treatments included the same amount of nitrogen (100.9 kg N ha-1) and consisted of: 100% poultry litter at preplant (PL), 67% poultry litter at preplant + 33% liquid urea ammonium nitrate (UAN) at sidedress (PLUAN), 33% granular fertilizer pre-plant + 67% liquid urea ammonium nitrate at sidedress (FERT), and a no nutrient applied control (NONE). Sidedress applications were performed prior to flowering using a coulter with knife spaced 10 cm from cotton row. Results show that nutrient treatments were the main influence on cotton growth with 11% taller plants, 31.8% greater dry weight, and 13.4% more cotton bolls, respectively, for the inorganic fertilizer treatments (FERT) compared to the poultry litter (PL) treatment in 2022. The FERT treatment had 10.7% taller plants, 16.9% greater dry weight, and 9.3% more cotton bolls compared to the PL treatment in 2023. The Mow method hindered emergence for the 2022 and 2024 seasons where rye dry biomass was 6464 and 5982 kg ha-1, respectively, but no differences in emergence were evident across methods in 2023 with rye biomass production of 3723 kg ha-1. For both seasons, no significant differences were realized between any of the nutrient treatments for seed cotton yield, but the yield was lower for MowIncorp in 2023 compared to the Roll and Mow. In conclusion, poultry litter was successful in sustaining cotton yield similar to inorganic fertilizers under cover crop residue management without tillage
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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