1,720,978 research outputs found
Hydrogeology of the southern Middle Tiber Valley (Central Italy)
No full textThe aim of this work is to contribute to the hydrogeological knowledge regarding the southern Middle Tiber Valley focusing on the continental and marine units that fill the Paglia-Tiber graben in the northern Latium Region (central Italy). An important hydrogeological survey was performed in the summer of 2008, and a considerable quantity of piezometric, physio-chemical and flow data were collected. Four geological cross sections were realized, and a hydrogeological map and a groundwater quality map of the area were produced to obtain a conceptual groundwater flow mode
Hydrogeological setting of a Rome city sector: shallow groundwater in the right side of Tiber River inside the G.R.A highway
No full textThis paper presents a detailed hydrogeological study of a Rome city sector, in the right side of Tiber River, inside the G.R.A. highway. A hydrogeological model of this city sector has been developed through geologic-stratigraphical analysis also of data provided by the Environmental Protection Department of Roma Capitale (Municipality of Rome) and the observation of historical topographic and thematic maps. This model is more detailed than the most recent Hydrogeological Map of Rome (1:50.000 scale), published in 2015, and allowed identifying the shallowest groundwater flow systems for the first time. This detailed model can be a very useful tool for agencies and administrations managing the protection of groundwater resources
Parameterization, sensitivity analysis, and inversion: an investigation using groundwater modeling of the surface-mined Tivoli-Guidonia basin (Metropolitan City of Rome, Italy)
No full textWith respect to model parameterization and sensitivity analysis, this work uses a practical example to suggest that methods that start with simple models and use computationally frugal model analysis methods remain valuable in any toolbox of model development methods. In this work, groundwater model calibration starts with a simple parameterization that evolves into a moderately complex model. The model is developed for a water management study of the Tivoli- Guidonia basin (Rome, Italy) where surface mining has been conducted in conjunction with substantial dewatering. The approach to model development used in this work employs repeated analysis using sensitivity and inverse methods, including use of a new observation-stacked parameter importance graph. The methods are highly parallelizable and require few model runs, which make the repeated analyses and attendant insights possible. The success of a model development design can be measured by insights attained and demonstrated model accuracy relevant to predictions. Example insights were obtained: (1) A long-held belief that, except for a few distinct fractures, the travertine is homogeneous was found to be inadequate, and (2) The dewatering pumping rate is more critical to model accuracy than expected. The latter insight motivated additional data collection and improved pumpage estimates. Validation tests using three other recharge and pumpage conditions suggest good accuracy for the predictions considered. The model was used to evaluate management scenarios and showed that similar dewatering results could be achieved using 20 % less pumped water, but would require installing newly positioned wells and cooperation between mine owners
Can we calibrate a complex groundwater model just by running an automatic calibration code? A case study from Italy: The Acque Albule Plain model (Rome)
No full textThis note presents a calibration of a model of a complex groundwater system located in central Italy, in the subsiding Acque Albule (AA) Plain near Rome (Italy). There are two main aquifers in this system. The first is the limestone fractured bedrock, partially confined by Pliocene-Pleistocene deposits, while the second one is within the fractured travertine and is unconfined. These two aquifers are hydraulically connected in correspondence of the centre of the plain, where deep hydrothermal water upwells from the limestone bedrock through the Plio-Pleistocene deposits into the travertine. The AA groundwater model is applied to a 55-km 2 area and is developed by using MODFLOW-2005, discretized by 100 m × 100 m cells and three layers. The calibration process applied to this model consists of several steps using estimation methods along with sensitivity analysis and geological information. The final model fit shows the importance not only of applying automatic estimation methods for calibration processes, but also the need to change the conceptual model and collect new data to understand the system better. Copyright © 2011 IAHS Press
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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