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Inverse Analysis for the optimization of a multiparametric geotechnical model in a transient seepage scenario|Analisi Inversa per l'ottimizzazione di un modello geotecnico multiparametrico in uno scenario di filtrazione transitoria
No full textThe accurate characterization of the transient water flow through unsaturated domains requires a precise knowledge of model parameters that govern the complex interactions of soil and fluid properties with boundary conditions. Inverse Analysis, a powerful computational technique, has emerged as a cornerstone in the process of estimating these parameters based on observational data. The paper explores the application of Inverse Analysis to transient seepage problems in unsaturated domains, providing insights into the use of indirect estimation techniques for determining critical model parameters. The transient seepage analyses refer to a specific case study, a river embankment section along the river Secchia (Modena, Italy), which has been extensively monitored for many years, providing a large database of observations to be used in such indirect process. By discussing potentials and limitations of this approach, when applied to multi-parametrical and multi-layered domains, the paper aims to foster a deeper understanding of its role in refining the accuracy and reliability of seepage models. Moreover, a comprehensive exploration of the use of both qualitative (graphical comparison) and quantitative (metrics and indices) methodologies for assessing the performance of indirect simulations is carried out with the final aim of identifying a fast and effective strategy to guide the choice of the most suited set of optimized model parameters
Learning from a well-documented geotechnical cold case : the Two Towers of Bologna, Italy.
Get PDFThe Garisenda Tower and the Asinelli Tower, also widely known as the Two Towers, are the best preserved and famous medieval towers in the city of Bologna (Northern Italy). Standing one close to the other, right in the heart of the city centre, the Two Towers are delicate remains of the old towered city, which counted more than 75 towers in the 12th century.
The foundations of historic towers and the surrounding soil often hide major hazards for the long-term preservation of these heritage structures. The initial fundamental step to this aim is indeed a deep understanding of their original conception, foundations and subsoil. However, the idea that also such elements are an integral part of the overall structure, and thus subjected to the same conservation rules, is relatively new. The present paper outlines the investigation criteria applied to the soil-foundation systems of the Two Towers of Bologna and describes the authenticity of their characteristics, through the interpretation of new experimental data and the analysis of historical documents. A geotechnical perspective on this type of monuments turns out to be crucial in order to effectively understand the soil-structure interaction mechanisms, which govern their safety conditions over time. This study also aims to better understand the reasons why the Two Towers of Bologna, despite their numerous similarities, have reached completely different structural configurations.
The methodology described to investigate this case study, which required the integration of several aspects, can be usefully applied to any historic tower
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
Climate control on stacked paleosols in the Pleistocene of the Po Basin (northern Italy)
Get PDFPaleosols are recurrent features in alluvial successions and provide information about past sedimentary dynamics and climate change. Through sedimentological analysis on six sediment cores, the mud-dominated succession beneath the medieval ‘Two Towers’ of Bologna was investigated down to 100 m depth. A succession of weakly developed paleosols (Inceptisols) was identified. Four paleosols (P1, P2, P3 and PH) were radiocarbon-dated to 40–10 cal ka bp. Organic matter and CaCO3 determinations indicate low groundwater levels during soil development, which spanned periods < 5 ka. The development and burial of soils, which occurred synchronously in the Bologna region and in other sectors of the Po Plain, are interpreted to reflect climatic and eustatic variations. Climatic oscillations, at the scale of the Bond cycles, controlled soil development and burial during Marine Isotope Stage (MIS) 3 (P1 and P2). Rapid sea-level oscillations probably induced soil development at the MIS 3/2 transition (P3) and favored burial of PH after 10 ka bp. Weakly developed paleosols in alluvial successions can provide clues to millennial-scale climatic and environmental variations. In particular, the paleosol-bearing succession of the Po Plain represents an unprecedent record of environmental changes across the Late Pleistocene (MIS 3 and 2) in the Mediterranean region
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
Calibrazione mediante analisi inversa dei parametri idraulici e di ritenzione di un rilevato arginale soggetto ad erosione retrogressiva per sottofiltrazione
No full textIl contributo descrive una strategia per la modellazione numerica bidimensionale del moto di filtrazione in regime transitorio che si sviluppa in una sezione arginale del fiume Po, al variare del livello idrometrico del fiume. La sezione di indagine, che si trova in località Guarda Ferrarese (FE), è sede di un ‘’fontanazzo‘’ (sand boil) storico, che si riattiva in concomitanza di eventi di piena anche di media intensità.
Il codice utilizzato per le analisi è il software commerciale Hydrus 2D di Pc-Progress, che è stato utilizzato per condurre dapprima le simulazioni dirette, quindi quelle indirette (Inverse Analysis) al fine di ottimizzare i parametri idraulici e di ritenzione del modello numerico elaborato. Durante una recente campagna di indagine geotecnica sono state svolte prove in sito e installati piezometri tipo Casagrande per il monitoraggio della falda superficiale e del primo acquifero. Le informazioni raccolte sono state utilizzate per individuare il range di variazione dei parametri, al fine dell’ottimizzazione degli stessi, e per condurre le simulazioni indirette. Il contributo costituisce un primo step di analisi, fondamentale per calibrare i modelli di filtrazione della sezione di studio. Questo tipo di analisi contribuisce a migliorare la metodologia di analisi del fenomeno di erosione retrogressiva (Backward erosion piping), problematica che mette a rischio la stabilità di numerose sezioni arginali del bacino idrografico del fiume Po, in vista dell’elaborazione di avanzati modelli numerici che non solo siano descrittivi dei fenomeni osservati ma anche predittivi nel medio-lungo periodo
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