1,721,213 research outputs found
Advanced Computer Technologies for Integrated Agro-Hydrologic Systems Modeling: Coupled Crop and Hydrologic Models for Agricultural Intensification Impacts Assessment
Full text linkL'accoppiamento di modelli idrologici e di coltura sta diventando sempre più un compito importante quando si affrontano gli studi sui sistemi agro-idrologici. Sia per la conservazione delle risorse che per il miglioramento dei sistemi di coltivazione, le complesse interazioni tra regime idrologico e componenti di gestione delle colture richiedono un approccio integrativo per essere pienamente compresi. Tuttavia, la letteratura offre risorse limitate sull'accoppiamento di modelli che si rivolgono agli scienziati ambientali. In effetti, le guide principali sono destinate principalmente agli specialisti di computer e le rendono difficili da comprendere e da applicare. Per colmare questa lacuna, presentiamo un'estesa ricerca sui modelli di coltura e sui modelli idrologici che si rivolgono agli studi di modellizzazione agro-idrologica della terra nella sua complessità integrativa. L'obiettivo principale è capire la relazione tra l'intensificazione agricola e il suo impatto sull'equilibrio idrologico. Abbiamo fornito documentazione, classificazioni, applicazioni e riferimenti delle tecnologie disponibili e delle tendenze di sviluppo.
Abbiamo applicato i risultati dell'indagine accoppiando il modello idrologico DREAM con il modello di coltura DSSAT. Entrambi i modelli sono stati aggiornati sia sulla sorgente del codice (DREAM) che sulla base operativa (DSSAT) per l'interoperabilità e la parallelizzazione. Il modello risultante opera su una griglia e su un passo giornaliero. Il modello viene applicato nell'Italia meridionale per analizzare l'effetto dell'applicazione del fertilizzante sulla generazione di ruscellamento tra il 2000 e il 2013. I risultati dello studio mostrano un impatto significativo dell'applicazione dell'azoto sulla resa idrica. Infatti, quasi 71,5 mila metri cubi di acqua piovana per ogni chilogrammo di azoto e per ettaro vengono persi come riduzione del coefficiente di deflusso. Inoltre, una correlazione significativa tra la quantità di applicazioni di azoto e il deflusso si trova su base annuale con il coefficiente di Pearson di 0,93.Coupling hydrologic and crop models is increasingly becoming an important task when addressing agro-hydrologic systems studies. Either for resources conservation or cropping systems improvement, the complex interactions between hydrologic regime and crop management components requires an integrative approach in order to be fully understood. Nevertheless, the literature offers limited resources on models’ coupling that targets environmental scientists. Indeed, major of guides are are destined primarily for computer specialists and make them hard to encompass and apply. To address this gap, we present an extensive research to crop and hydrologic models coupling that targets earth agro-hydrologic modeling studies in its integrative complexity. The primary focus is to understand the relationship between agricultural intensification and its impacts on hydrologic balance. We provided documentations, classifications, applications and references of the available technologies and trends of development.
We applied the results of the investigation by coupling the DREAM hydrologic model with DSSAT crop model. Both models were upgraded either on their code source (DREAM) or operational base (DSSAT) for interoperability and parallelization. The resulting model operates at a grid base and daily step. The model is applied southern Italy to analyze the effect of fertilizer application on runoff generation between 2000 and 2013. The results of the study show a significant impacts of nitrogen application on water yield. Indeed, nearly 71.5 thousand cubic-meter of rain water for every kilogram of nitrogen and per hectare is lost as a reduction of runoff coefficient. Furthermore, a significant correlation between the nitrogen applications amount and runoff is found at a yearly basis with Pearson’s coefficient of 0.93.Le couplage des modèles hydrologiques et culturaux est une tâche importante lorsqu’on aborde les études de systèmes agro-hydrologiques. Que ce soit pour la conservation des ressources ou l’amélioration des systèmes de culture, les interactions complexes entre le régime hydrologique et les composantes de la gestion des cultures nécessitent une approche intégrative pour être pleinement comprises. Néanmoins, la littérature offre des ressources limitées sur le couplage de modèles qui cible les scientifiques. En effet, la plupart des guides sont principalement destinés aux informaticiens et sont difficiles à appliquer. Pour combler cette lacune, nous présentons une recherche approfondie sur le couplage des modèles de cultures et des modèles hydrologiques, qui cible les études de modélisation agro-hydrologique dans leur complexité intégrative. L'objectif principal est de comprendre la relation entre l'intensification agricole et ses impacts sur l'équilibre hydrologique. Nous avons fourni des documentations, des classifications, des applications et des références des technologies disponibles et des tendances de développement.
Nous avons appliqué les résultats de l'enquête en couplant le modèle hydrologique DREAM au modèle de culture DSSAT. Les deux modèles ont été mis à niveau soit sur leur code source (DREAM), soit sur leur base opérationnelle (DSSAT) pour assurer l’interopérabilité et la parallélisation. Le modèle résultant est appliqué dans le sud de l'Italie pour analyser l'effet de l'application d'engrais sur la production de ruissellement entre 2000 et 2013. Les résultats de l'étude montrent un impact significatif de l'application d'azote sur l'apport en eau. En effet, près de 71 500 mètres cubes d'eau de pluie par kilogramme d'azote et par hectare sont perdus sous la forme d'une réduction du coefficient de ruissellement. De plus, une corrélation significative entre la quantité d’application d’azote et le ruissellement est constatée chaque année avec un coefficient de Pearson de 0,93
Interpretazione e decisione. Diritto ed economia. Atti del XVI. Congresso Nazionale della Società Italiana di Filosofia giuridica e politica
No full text
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
Biotechnical characteristics of root systems of typical Mediterranean species
No full textVegetation can significantly contribute to stabilise sloping terrain by adding cohesion to soil: this reinforcement depends on the morphological characteristics of the root systems and the tensile strength of single roots. The paper presents the results of research carried out in order to evaluate the biotechnical characteristics of the root system of three typical Mediterranean plant species which can affect slope stability. The species considered in the present study are Lygeum spartum L. (a perennial herbaceous monocotyledonous), Atriplex halimus L. and Pistacia lentiscus L. (two dicotyledonous shrub species). The plant specimens were collected in the Basilicata region (Southern Italy) by in situ excavation to obtain the whole root systems. Single root specimens for each species were sampled and tested for tensile strength measurement, and the complete root systems were analysed to evaluate the root density distribution with depth in terms of Root Area Ratio. The resulting data have been used to calculate the reinforcing effect in terms of increased shear strength of the soil using the model of Wu (1976, Investigation of landslides on Prince of Wales Island. Geotech. Eng. Rep. 5 Civil Eng. Dep. Ohio State Univ. Columbus, Ohio, USA) and Waldron (1977, Soil Sci. Soc. Am. J. 41(3), 843-849), a simple and widespread model based on the reinforced earth theory. The results show that root reinforcement exerted by L. spartum is stronger than the reinforcement exerted by P. lentiscus and A. halimus in the upper layers of the soil, while P. lentiscus presents higher reinforcement values in deeper horizons. A. halimus presents lower values than either of the other species studied
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
- …
