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Geomorphologic approach to sinthesis of direct runoff hydrograph from the Upper Tiber River basin, Italy
No full textRank Exponent-Based Reduction of Higher Order Electric Vehicle Systems
No full textElectric vehicles (EVs) are gaining an ever-growing popularity in the society as the green vehicles of the next future, i.e., vehicles independent of oil and not producing greenhouse gases. The modelling of these vehicles is made complex by their higher-order nature. Hence, reduction methods are more and more proposed in the literature. To the best of the authors' knowledge, this is the first paper proposing to exploit both the rank exponent (RE)-based reduced order (RO) modeling of higher-order electric vehicle system (HOEVS) of order five, and the error minimization based reduction approach by employing the grey-wolf optimization (GWO) algorithm. The Markov parameters (MaPas) and time moments (TiMos) of HOEVS, and its ROEV model (ROEVM) are exploited for obtaining the desired ROEVM of order two. For error minimization, a weight associated objective function is framed by utilizing HOEVS's and ROEVM's MaPas and TiMos. The weight ascertainment is done based on transient and step responses of desired ROEVM with respect to HOEVS. The GWO algorithm is then employed to optimize the weighted objective function under defined constraints. Firstly, steady state matching constraint is employed to ensure that ROEVM accurately captures the steady state behavior of HOEVS. Secondly, the Hurwitz stability criterion is incorporated as a constraint to guarantee the stability of ROEVM. To validate the effectiveness of the presented approach, a comparative analysis with other reduction methods has been carried out, in terms of the step, impulse, Nichols, Bode, and error plots along with time domain specifications and error indices. The responses and tabulated data showcase the superiority of the proposed method, thus confirming the efficacy and efficiency of our approach in reducing the order of electric vehicle systems
Geomorphologic approach to synthesis of direct runoff hydrograph from the Upper Tiber River basin, Italy
No full textThe effective rainfall-direct runoff relationship was investigated for forty events on tour large basins by using a geomorphologic representation of the instantaneous unit hydrograph (IUH) proposed by Gupta et al. (1980). These basins are a part of the Upper Tiber River basin located in Central Italy and range in area from 934 km2 to 4,147 km2. For each event the volume of direct runoff was obtained by hydrograph separation. The effective rainfall hyetograph was then determined by using the two-term Philip infiltration equation in conjunction with a volume balance analysis. The geomorphologic parameters required by the IUH were extracted from a topographic map of each basin with the map scale of 1:200,000. It was found that the dimensionless form of the IUH remained practically Constant from one basin to another. By convoluting the geomorphologic IUH, derived for each basin, with the effective rainfall, the direct runoff hydrograph was synthesized for each event. The model results compare reasonably well with observations of each basin. The maximum and mean errors in computing peak flow were 33% and 15% respectively. Furthermore, the magnitudes of these errors did not depend upon the basin area. A sensitivity analysis of the model structure revealed that its order of geomorphologic representation could be reduced by at least one without a significant loss of accuracy. This small reduction in order amounted to a considerable reduction in geomorphologic complexity and computational effort. The model results were quite sensitive to basin lag and sorptivity parameter of the infiltration equation. A 10% variation in basin lag resulted in approximately 10% variation of computed peak discharge. However, a 10% variation in sorptivity produced an approximately 20% mean variation in computed peak discharge
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
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