1,720,979 research outputs found
Visualizing the Pareto surface
No full text1 online resource (PDF, 19 pages, includes illustrations)Hosseini, Bamdad; Liu, Guoqing; Puelz, Charles; Tracht, Samantha; Smilovic, Mikhail. (2012). Visualizing the Pareto surface. Retrieved from the University Digital Conservancy, https://hdl.handle.net/11299/181207
The limits of increasing food production with irrigation in India
No full textGrowing populations and dietary shifts to include higher proportions of meat are projected to double global food demand by 2050. Previous global studies have proposed and evaluated possible solutions by closing agricultural yield gaps, defined as the difference between current and potential crop yields. We compliment previous studies by developing a method for more accurately calculating potential changes in cereal grain production under different irrigation scenarios, explicitly incorporating yield differences associated with different sources of irrigation. Irrigating with groundwater often leads to higher crop yields than irrigating with surface water because of the greater facility to tailor both the volumes of water and the timing of application. Two possible scenarios for increasing production in India are examined, the first where all non-irrigated fields are irrigated proportionally to the State-specific distribution of irrigation sources, and the second where all non-irrigated fields are irrigated with groundwater: Rice production increases by 14 and 25 % in scenarios 1 and 2 respectively, but wheat production increases by only 3 % in both scenarios. Increased irrigation water consumption from irrigating fields that are currently non-irrigated is estimated at 31 % for rice and 3 % for wheat using the Global Crop Water Model. A third scenario estimates the potential loss in production without the use of irrigation: rice would be 75 % and wheat 51 % of current production. Our methodology and results can help policy makers estimate the current and potential contribution of irrigation sources to agricultural production and food security in India and can with facility be applied elsewhere
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
The extremes and in-betweens of irrigation: new methods to evaluate potential changes in agricultural production and crop water use
No full textAgriculture uses more water than any other human activity in the world. Projections of increasing demands on agriculture along with climatic change and variability necessitate evaluating the current and potential contributions of irrigation water to agriculture, and initiatives to improve production while reducing our demands on surface and groundwater systems. This thesis develops and demonstrates new procedures to determine appropriate estimates of agricultural production and water use resulting from proposed changes in irrigation water use. This research improves on previous efforts to evaluate the increasing or decreasing of full irrigation at regional-scale, and presents the first broadly-applicable methodology for evaluating supplemental irrigation at nested spatiotemporal scales.Irrigation has generally been evaluated at its extremes, defining areas exclusively as either fully irrigated or non-irrigated. Previous efforts to estimate the contributions of irrigation to current yields and evaluate potential changes in production have determined generalizations relating irrigated and non-irrigated yields from temporally and spatially limited statistical data. Such efforts have admittedly limited their investigations by evaluating only the extremes of irrigation and further by correlating the separate contributions of surface water and groundwater to production. This research first improves on estimating the potential of the extremes, that is increasing or decreasing full irrigation, by evaluating changes in irrigated area as they relate specifically to irrigation-source. Further, this research develops and demonstrates the first broadly-applicable methodologies for evaluating the in-betweens of full and non-irrigation, namely supplemental irrigation. Supplemental irrigation holds significant opportunity to increase agricultural and water productivity, and reduce water use. By recognising a system of irrigation different than the extremes, including potentially reducing water use on irrigated fields and increasing limited water use on non-irrigated fields at appropriate and opportune times, the in-betweens of irrigation allow for the benefits of supporting production while not necessarily further appropriating water for irrigation.This thesis first evaluates the potential changes in agricultural production and water use resulting from the complete expansion of full irrigation under two scenarios related to the adoption of specific irrigation sources, demonstrated for rice and wheat in India. The results show a potential increase in production of 14-25% for rice and 3% for wheat, with a 31% and 3% increase in water use respectively. Similarly, the study investigates the decreases in agricultural production from stopping irrigation, and we estimate that rice would be at 60% of current production, and wheat at 51%. Together, these two evaluations showcase the end ranges of the relationship between agricultural production and irrigation water use. Specifically, this is achieved by partitioning region-specific rice and wheat production into that related to irrigated and non-irrigated areas, and further by irrigation source. This partitioning of production by irrigation source, to the best of our knowledge, is novel. The partitions are used to estimate potential increases in agricultural production, and evaluating such increases as explicitly related to irrigation source, is similarly novel.L'agriculture est l'activité humaine qui utilise le plus d'eau au monde. Les projections de demande croissante d'agriculture, au même titre que les changements et la variabilité du climat, nécessitent une évaluation des contributions présentes et potentielles d'irrigation dédiée à l'agriculture ainsi que des initiatives pour améliorer la production tout en réduisant nos demandes sur les systèmes d'eaux de surfaces et souterraines. Cette thèse développe et démontre de nouvelles procédures afin d'estimer la production agricole et la consommation d'eau résultant des changements proposés en irrigation. Ces procédures améliorent les efforts antérieurs pour évaluer l'augmentation ou la réduction d'irrigation totale à une échelle régionale. De plus, elles évaluent de façon innovatrice une irrigation complémentaire à des échelles spatio-temporelles.L'irrigation est généralement évaluée à ses extrêmes, en définissant les aires d'agriculture complètement irriguées ou non-irriguées. L'estimation des contributions d'irrigation aux cultures présentes et l'évaluation des changements potentiels de rendement, tels que fait anciennement, ont pu déterminer les généralisations reliées entre les cultures des aires irriguées et non-irriguées à partir d'une banque de données statistiques limitée, provenant principalement des États-Unis. Ces investigations antérieures sont limitées car elles n'évaluaient que les extrêmes d'irrigation et corrélaient les contributions séparées de l'eau de surface et de l'eau souterraine à la production agricole. La présente recherche améliore premièrement les évaluations du potentiel de rendement agricole aux extrêmes d'irrigation en reconnaissant les contributions séparées des eaux de surfaces et des eaux souterraines à la production. Deuxièmement, cette thèse développe et démontre les premières méthodes largement applicables pour l'évaluation du rendement agricole des zones intermédiaires entre les aires complètement irriguées et celles non-irriguées, c'est-à-dire l'irrigation complémentaire. L'irrigation complémentaire rend possible l'augmentation de la productivité agricole tout en réduisant la consommation d'eau. L'adoption d'un système d'irrigation autre que les extrêmes qui prend en compte des paramètres tels une potentielle baisse de consommation d'eau dans les champs irrigués et une hausse de consommation d'eau dans les champs non-irrigués à de moments opportuns, crée des zones intermédiaires d'irrigation et permet ainsi un support accru pour la production tout en minimisant l'irrigation. Cette thèse évalue en premier lieu les changements potentiels en production agricole et de consommation d'eau suite à une expansion complète d'irrigation en utilisant deux scénarios reliés à l'adoption de sources d'irrigation spécifiques, et ce, démontré pour le riz et le blé en Inde. Les résultats démontrent une augmentation potentielle de rendement de 14-25% pour le riz et 3% pour le blé associé à une augmentation d'irrigation de 31% et 3% respectivement
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
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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