1,720,985 research outputs found
Monitoring river morphological changes using high resolution multitemporal sar images: a case study on orco river, italy
No full textEnhancing sediment transport model reliability through Sensitivity Analysis: A Case Study in the Po River
No full textThe limited observational data on river bedload presents a significant challenge in understanding sediment transport processes. However, with recent advancements in computing capability, availability of remotely sensed data, and smart sensors, it is nowadays possible to model these transport processes in river networks at catchment scale. Nevertheless, the results of these models are often not robust due to inherited uncertainty and the stochastic nature of the input parameters.
To manage these uncertainties and improve the robustness of model outputs, sensitivity analysis plays a crucial role. Sensitivity analysis is a method to study how changes in a numerical model's input factors contribute to variations in its output.
This project aims to apply Global Sensitivity Analysis (GSA) techniques to the D-CASCADE (Dynamic CAtchment Sediment Connectivity And Delivery) model, for the Po River network in Italy. D-CASCADE is a network-based (or graph-based) model that simulates material movement as distinct transport processes at the reach scale, or ‘cascades,’ defined by their provenance, sediment volume, and interactions downstream, at daily timestep.
To conduct the GSA, we use the SAFE toolbox, supporting both the generation of 5,000 random input factor combinations within defined ranges and distributions, as well as the quantification of the impact of each input factor's variation on the output.
In this work, we focus on the sensitivity estimation of active channel widths and riverbed slopes for every reach of the simulated network. These two input factors are key drivers of the transport capacity and the consequent sediment fluxes generated for the various sediment transport formulas implemented in D-CASCADE. The active transport width (the portion of the channel where bedload transport is active for a specific discharge) is largely unknown, even in data-rich contexts. Hydraulic slopes are also often unknown and generally replaced with topographic slopes which are largely dependent on the quality of the DEM used. Active widths and slopes are then structurally inherently uncertain although they drive the model results. Through GSA, we evaluate how simultaneous random changes in these two input factors affect the simulated sediment fluxes and budgets. Results are analyzed both at the reach scale (sensitivity to local parameters) and the network scale (sensitivity to upstream parameters).
The presented methodology allows us to obtain important information about the effects of structural uncertainties in sediment transport modelling at network scale. These findings provide a foundation for enhancing the model's accuracy and resolving uncertainty in sediment transport prediction
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
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
Café fluvial : Mapping, monitoring and modelling fluvial connectivity and river processes at the network scale
No full textLe jeudi 14 décembre, Simone Bizzi et Barbara Belletti viendront nous présenter les travaux qu'ils mènent dans le cadre de leurs post-doctorats autour d'une communication intitulée : "Mapping, monitoring and modelling fluvial connectivity and river processes at the network scale" Rendez-vous le jeudi 14 décembre à 13h30 à l'ENS de Lyon (15 parvis René Descartes, 69007, Lyon), en salle D4.235 (anciennement bâtiment Recherche, salle R230) pour les écouter et discuter avec eux de leurs travaux...
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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