1,720,980 research outputs found
A box-model approach for reservoir operation during extreme rainfall events: A case study
No full textExtreme rainfall events in an urban area pose various challenges to the water resource managers in terms of flood mitigation, inundation, water conservation and harvesting for drinking water supply. The objective of this study is to apply the box-model approach to evaluate reservoir operation during extreme rainfall events. A large water supply reservoir in Chennai was chosen to carry out this study. A box model, based on input–output parameters, is proposed to simulate the reservoir operation and hydraulic behaviour. Hydrologic Engineering Centre-Hydrologic Modelling System (HEC-HMS) has been used to simulate the reservoir inflow hydrograph and to understand the run-off characteristics of the basin. Three extreme rainfall events occurred in past have been selected for the analysis. Three different scenarios have been framed to assess the reservoir performance. Reducing the initial storage to 50% and releasing water at the beginning of the event gives a possible solution for flood mitigation in reducing the outflow volume by 9–37% and delaying the time to peak by 1–6 h. Though the reduced outflow volume from this reservoir is less, it can help to mitigate the flood inundation to a significant extent. Thus the box-model approach presented here can be utilised as a simple tool to generate the various combinations of outflow hydrographs for any reservoir
Discrete Boltzmann Equation model of polydisperse shallow granular flows
No full textA polydisperse shallow mixture consisting of N p solid phases (N p ≥ 1) and one fluid phase (the ambient fluid) is a reliable model for several industrial and environmental flows, as e.g. landslides, avalanches, debris flows and fluidized beds. The description and prediction of these flows is of primary importance, mainly with respect to the mitigation and protection from natural hazards. This paper is aimed at deriving the polydisperse shallow granular flow equations by depth-averaging mass and momentum equations of the mixture and at formulating an equivalent Discrete Boltzmann Equation (hereinafter DBE) model as solution method. The reason is the simplicity and the versatility of the DBE, which consists of a set of purely advective, linear, first order partial differential equations, whose numerical integration does not need sophisticated methods. Both 1D and 2D benchmarks, concerning with the propagation of discontinuities in three-phase shallow granular flows, are obtained by applying the finite differences Lax-Friedrichs (hereinafter LF) method to the polydisperse shallow granular flow equations. The overall agreement is good, showing that the DBE and the LF numerical results are equivalent
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
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
Depth averaged modelling of loose rectangular granular piles collapsing in water
No full textThe collapse of a submerged granular pile under the action of the gravity force is investigated by means of a depth averaged model (hereinafter DAM). The granular pile is a mixture of solid particles and ambient liquid, totally covered by a layer of ambient liquid. The DAM is obtained by depth-averaging the mass and momentum equations of the mixture and the ambient fluid and is aimed at providing estimates of technical quantities regarding the considered phenomenon. The DAM is numerically solved by adopting an equivalent Discrete Boltzmann Equation model (hereinafter DBE) as solution method. The main advantage yielded by the DBE is the possibility to turn the original system of strongly non linear partial differential equations, which would require the resort to complex numerical schemes, into a purely advective, linear, first order one. Previously published experimental and numerical data, relative to the collapse of loose rectangular granular piles in water, are reproduced by the proposed model and a satisfactory agreement is found, revealing that the DAM is able to describe reliably the overall dynamics, in terms of quantities of technical interest as the height of the submerged granular flow and the instantaneous position of its front
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