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Uso de regresão linear múltipla e redes neurais artificiais na estimativa da interferência de plantas daninhas em cultivos agrícolas
Get PDFThe efficiency of weed control in agricultural crops depends on the adoption of the
control method at the right time, minimizing the interference of the weed community.
However, a definition of the beginning and end of the control season is difficult to
measure by the producer due to the particularities of the weed community, the crops,
and the management and edaphoclimatic conditions of each cultivation site. One of the
alternatives to solve this problem is the use of models based on statistical methods or
methods of machine learning developed in the field of artificial intelligence that can be
adequate to predict the loss of yield of agricultural cultures due to the interference of
weeds. Thus, the objective was to verify if the RLM and RNAs models can predict the
beginning of weed control, compare the effectiveness of RNAs with traditional
sigmoidal models and also evaluate the ability of RNAs to estimate weed control for
different crops and acceptable productivity loss classes and thereby validate a new
alternative for modeling and predicting competition between weeds and agricultural
crops. The experiments were conducted at the Rafael Fernandes Experimental Farm,
Mossoró, RN. The design used was in randomized blocks, with three replications. The
treatments consisted of six periods for the beginning of weed control (0, 7, 14, 21, 28,
32 and 42) days after emergence (DAE) for the onion culture and for the sesame and the
melon foramen (130, 260, 390, 520, 650, 1300) and (130, 260, 390, 520, 972) degrees
days (GD) after sowing sesame and transplanting melon seedlings, respectively. The
RLM models based on non-destructive and destructive inputs on the weed community
are able to estimate losses of onion productivity, however with low precision. The ANN
models considering only the coexistence period and the irrigation system have similar
performance to the Multiple Linear Regression models. However, the inclusion of
variables related to weed density (non-destructive) and fresh matter (destructive) in
RNA models raises the predictive capacity of networks to values close to 99% correct.
The RNA model, which made a combination of non-destructive (density) and
destructive (Matter Fresh) inputs, dispenses with other more specific inputs such as the
C3 / C4 and Monocotyledons / Eudicotyledons (M / E) species. The weed interference
period is the main factor to infer the degree of weed interference in the Sesame and
Melon cultures. The models of RNAs with the best performance can indicate the
beginning of weed control, since they are able to accurately estimate losses caused by
weed interferenceA eficiência no controle das plantas daninhas nos cultivos agrícolas depende da adoção
do método de controle na época correta, minimizando a interferência da comunidade
infestante. Todavia, a definição do início e fim da época de controle é de difícil
mensuração pelo produtor devido às particularidades da comunidade infestante, das
culturas e das condições de manejo e edafoclimáticas de cada local de cultivo. Uma das
alternativas para a solução deste problema é o uso de modelos baseados em métodos
estatísticos ou métodos de aprendizado de máquina desenvolvidos no campo da
inteligência artificial que possam ser adequados para fazer previsões da perda de
rendimento de culturas agrícolas em virtude da interferência de plantas daninhas. Dessa
forma, este estudo tem como objetivo comparar a eficácia de modelos matemáticos
empíricos como as Regressões Lineares Múltiplas (RLM) com modelos de Redes
Neurais Artificiais (RNAs) para modelagem da interferência de plantas daninhas em
estimar o início do controle de plantas daninhas em diferentes classes de perdas de
produtividades aceitáveis de culturas agrícolas. Os experimentos foram realizados
durante os anos de 2016, 2017 e 2018, usando para o estudo as culturas do melão,
gergelim e cebola. O delineamento utilizado foi em blocos ao acaso, com três
repetições. Os tratamentos do primeiro experimento, referente à cultura da cebola foram
compostos por seis períodos para o início do controle de plantas daninhas (0, 7, 14, 21,
28, 32 e 42) e expressos em dias após a emergência (DAE), ao passo que no segundo
experimento, para as culturas do gergelim e do meloeiro, os períodos foram (130, 260,
390, 520, 650, 1300 e (130, 260, 390, 520, 972), respectivamente, expressos em graus
dias (GD) após a semeadura do gergelim e o transplantio das mudas de melão. Os
resultados demonstraram que modelos RLM baseados em entradas não destrutivas e
destrutivas sobre a comunidade de plantas daninhas são capazes de estimar as perdas de
produtividade da cebola, porém com baixa precisão. Os modelos de RNAs considerando
apenas o período de convivência e sistema de irrigação possuem desempenho similar a
modelos de Regressão Linear Múltipla. No entanto, a inserção das variáveis
relacionadas à densidade de plantas daninhas (não destrutiva) e a matéria fresca
(destrutiva) nos modelos de RNAs eleva a capacidade preditiva das redes para valores
próximos a 99% de acerto. O modelo de RNAs que fizeram a combinação de entradas
não-destrutiva (Densidade) e destrutiva (Matéria Fresca) dispensa outras entradas mais
específicas, como a relação de espécies C3/C4 e Monocotiledôneas/Eudicotiledôneas
(M/E). O período de interferência de plantas daninhas é o principal fator para inferir o
grau de interferência das plantas daninhas nas culturas do gergelim e meloeiro. Os
modelos de RNAs com melhor performance podem indicar o início do controle de
plantas daninhas, uma vez que são capazes de estimar com precisão as perdas causadas
pela interferência das plantas daninhasCoordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPE
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
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
Author Under Sail The Imagination of Jack London, 1893-1902
No full textIn Author Under Sail, Jay Williams offers the first complete literary biography of Jack London as a professional writer engaged in the labor of writing. It examines the authorial imagination in London's work, the use of imagination in both his fiction and nonfiction, and the ways he defined imagination in the creative process in his business dealings with his publishers, editors, and agents. In this first volume of a two-volume biography, Williams traverses the years 1893 to 1902, from London's "Story of a Typhoon" to The People of the Abyss. The Jack London who emerges in the pages of Author Under Sail is a writer whose partnership with publishers, most notably his productive alliance with George Brett of Macmillan, was one of the most formative in American literary history. London pioneered many author models during the heyday of realism and naturalism, blurring the boundaries of these popular genres by focusing on absorption and theatricality and the representation of the seen and unseen. London created an impassioned, sincere, and extremely personal realism unlike that of other American writers of the time. Author Under Sail is a literary tour de force that reveals the full range of London as writer, creative citizen, and entrepreneur at the same time it sheds light on the maverick side of machine-age literature.Intro -- Title Page -- Copyright Page -- Dedication -- Contents -- Acknowledgments -- Introduction -- 1. Spirit Truth -- 2. From Absorption to Theatricality and Back Again -- 3. "I Will Build a New Present" -- 4. Sons as Authors -- 5. Fathers as Publishers -- 6. The Daughter as Author -- 7. Lovers as Authors -- 8. At Sea with the Family -- 9. Yellow News, Yellow Stories -- 10. The Return Home -- Notes -- Bibliography -- Index -- About Jay WilliamsIn Author Under Sail, Jay Williams offers the first complete literary biography of Jack London as a professional writer engaged in the labor of writing. It examines the authorial imagination in London's work, the use of imagination in both his fiction and nonfiction, and the ways he defined imagination in the creative process in his business dealings with his publishers, editors, and agents. In this first volume of a two-volume biography, Williams traverses the years 1893 to 1902, from London's "Story of a Typhoon" to The People of the Abyss. The Jack London who emerges in the pages of Author Under Sail is a writer whose partnership with publishers, most notably his productive alliance with George Brett of Macmillan, was one of the most formative in American literary history. London pioneered many author models during the heyday of realism and naturalism, blurring the boundaries of these popular genres by focusing on absorption and theatricality and the representation of the seen and unseen. London created an impassioned, sincere, and extremely personal realism unlike that of other American writers of the time. Author Under Sail is a literary tour de force that reveals the full range of London as writer, creative citizen, and entrepreneur at the same time it sheds light on the maverick side of machine-age literature.Description based on publisher supplied metadata and other sources.Electronic reproduction. Ann Arbor, Michigan : ProQuest Ebook Central, YYYY. Available via World Wide Web. Access may be limited to ProQuest Ebook Central affiliated libraries
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