1,721,161 research outputs found
Closure to "Deducing a drain spacing formula by applying dimensional analysis and self-similarity theory" by Vito Ferro
No full textThis paper is a closure of the discussions to the paper "Deducing a drain spacing formula by applying dimensional analysis and self-similarity theory
Comparing theoretically supported rainfall‐runoff erosivity factors at the Sparacia (South Italy) experimental site
No full textInterpreting rainfall‐runoff erosivity by a process‐oriented scheme allows to conjugate the
physical approach to soil loss estimate with the empirical one. Including the effect of runoff in
the model permits to distinguish between detachment and transport in the soil erosion process.
In this paper, at first, a general definition of the rainfall‐runoff erosivity factor REFe including
the power of both event runoff coefficient QR and event rainfall erosivity index EI30 of the
Universal Soil Loss Equation (USLE) is proposed. The REFe factor is applicable to all USLE‐based
models (USLE, Modified USLE [USLE‐M] and Modified USLE‐M [USLE‐MM]) and it allows to
distinguish between purely empirical models (e.g., Modified USLE‐M [USLE‐MM]) and those
supported by applying theoretical dimensional analysis and self‐similarity to Wischmeier
and Smith scheme. This last model category includes USLE, USLE‐M, and a new model, named
USLE‐M based (USLE‐MB), that uses a rainfall‐runoff erosivity factor in which a power of runoff
coefficient multiplies EI30. Using the database of Sparacia experimental site, the USLE‐MB is
parameterized and a comparison with soil loss data is carried out. The developed analysis shows
that USLE‐MB (characterized by a Nash–Sutcliffe Efficiency Index NSEI equal to 0.73 and a root
mean square error RMSE = 11.7 Mg ha−1) has very similar soil loss estimate performances as
compared with the USLE‐M (NSEI = 0.72 and RMSE = 12.0 Mg ha−1). However, the USLE‐MB
yields a maximum discrepancy factor between predicted and measured soil loss values (176) that
is much lower than that of USLE‐M (291). In conclusion, the USLE‐MB should be preferred in the
context of theoretically supported USLE type models
Caratteri energetici della precipitazione dedotti dalle distribuzioni dimensionali delle gocce di pioggia rilevate in Sicilia
No full textUna delle distribuzioni più utilizzate, per la sua flessibilità di adattamento e le numerose conferme sperimentali riscontrate, è la legge di Ulbrich che, come dimostrato da Carollo e Ferro (2011) utilizzando le 19189 distribuzioni misurate in Sicilia nel periodo Giugno 2006 – Marzo 2010, combinata con la relazione proposta da Ferro (2001) per la stima della velocità terminale delle gocce di pioggia, consente di calcolare la potenza cinetica in funzione dei parametri della distribuzione e dell’intensità della precipitazione. Nella memoria sono riportati i risultati ottenuti a partire dalle distribuzioni dimensionali delle gocce (DSD) di pioggia rilevate, nel periodo Giugno 2006 – Marzo 2014, mediante un disdrometro ottico installato presso il Dipartimento di Scienze Agrarie e Forestali dell’Università degli studi di Palermo. L’insieme delle DSD, rilevate con scansione temporale del minuto, è costituito da oltre 42000 distribuzioni. Nella memoria viene preliminarmente presentata una verifica dell’applicabilità della legge di Ulbrich utilizzando, come metodo di stima dei parametri, sia quello della massima verosimiglianza sia il metodo dei momenti, di più semplice applicazione. Successivamente, è mostrato che i valori di potenza cinetica dedotti dalle misure disdrometriche risultano sovrapponibili ad analoghe misure rilevate in aree territoriali differenti (Francia meridionale, Mississippi) e consentono di testare positivamente la relazione dedotta da Carollo e Ferro (2011). Le misure di potenza cinetica, inoltre, non hanno mostrato una dipendenza dal periodo dell’anno in cui accade l’evento meteorico. Infine è riportato il confronto tra le misure di potenza cinetica e la relazione di Wischmeier e Smith che dimostra l’applicabilità della suddetta relazione anche in ambiti territoriali molto diversi da quelli di originaria deduzione.One of the most applied drop size distribution, because of its flexibility and its applicability in different climatic conditions, is the Ulbrich’s law. As demonstrated by Carollo and Ferro (2011) using 19189 DSDs measured in Sicily in the period June 2006 – March 2010, the Ulbrich’s law combined with the relationship proposed byFerro (2001) for estimating terminal drop velocity allows to calculate the kinetic power as function of DSD parameters and rainfall intensity.
This paper shows the results obtained by DSDs measured in the period June 2006- March 2014 using the optical disdrometer installed at the Department of Agricultural and Forestry Sciences of University of Palermo. The dataset of DSD, that are recorded with a 1 min sampling time, is constituted of more than 42000 distributions.
At first, the reliability of Ulbrich’s law for reproducing measured DSDs is tested using both the maximum likelihood and the momentum method. The kinetic power values, calculated by Sicilian disdrometric measurements, overlap to similar values detected in other sites (Southern France, Mississippi) and allow to positively test the relationship deduced by Carollo and Ferro (2011). Kinetic power measurements are not dependent on the period of the year in which the rainfall event occurs.
Finally, the relationship proposed by Wischmeier and Smith for evaluating the specific and unit rainfall kinetic energy was positively tested
Assessing Stage-Discharge Relationships for Circular Overflow Structure
No full textCircular overflow structures are used in irrigation and drainage networks as water measuring structures. Different approaches can be found in the literature to formulate the stage-discharge relationship of the circular weir. They are mainly categorized in three groups: (1)methods trying to simplify the complex elliptic integrals coming from the theoretical discharge equation; (2)methods that use the orifice formula and a discharge coefficient specific for the circular weir; and (3)approaches using dimensional analysis and Buckingham's Theorem. In this study, a nondimensional stage-discharge formula was obtained using Buckingham's Theorem to define the flow over the sharp-crested circular weir. Then the current available methods and experimental data from the literature were employed to calibrate the theoretically deduced stage-discharge relationship. The effect of the approach channel on the stage-discharge formula was also investigated using the experimental data available in the literature. Finally, the performances of different stage-discharge relationships are discussed and practical suggestions are provided
Vito Ferro
No full textSeries 328 | Board of Pardons | Prisoners' pardon application case files | Vito FerroCase files consist of letters to the Governor, a formal application for a pardon, petitions and letters of support from the public and officials connected to the case. Cases illustrate the process of review by the board of cases of prisoners incarcerated in the Utah prison system to determine if they should be released before their regular sentence ended
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
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