1,720,972 research outputs found
Documenting and analysing to preserve: An integrated approach between laser scanning and Computational Fluid Dynamics. The case study of the column of the temple of Hera Lacinia near Crotone
No full textThe study presents the results of a multidisciplinary research that integrates terrestrial laser scanning (TLS) and computational fluid dynamics (CFD) to document and analyse an archaeological asset subject to natural hazards. The experimentation was conducted on the surviving column of the temple of Hera Lacinia, located in Capo Colonna near Crotone (Italy). The column, the fragments of the crepidoma and of the foundation constitute the most visible remains of the peripteral Doric temple (second quarter of the 5th century B.C.), belonging to the most important sanctuary of Magna Graecia. The temple, the sanctuary and the other ancient buildings, which are in the area of the Capo Colonna promontory, were destroyed over the centuries to obtain construction material. Today the column and the remains of the temple are located inside the National Archaeological Park of Capo Colonna, protected from human action, but sub-ject to natural phenomena which are dangerous or potentially dangerous in the long term. The wind exerts a constant erosion of the surface of the column and wear of the lower part of the shaft due to the continuous oscillations to which it is subjected; moreover, the wind thrust could add up to a possible seismic action. On the other hand, the geomorphological evolution of the promontory (coastal erosion and subsidence) causes the coastline to recede, and is responsible for landslides affecting the column-basement system. Starting from the point cloud acquired by the TLS, a mesh of the column, basement and surrounding terrain was created, aimed both at documentation, graphic analysis and CFD. The survey enabled the description of the current state of the column-basement system, documenting and measuring the shapes of the column, as well as the different inclinations of the individual parts caused by instabil-ity of the ground. Furthermore, the CFD model of the Hera Lacinia column was developed. The model is based on the three-dimensional Reynolds-Averaged Navier-Stokes (RANS) equations with the k-epsilon closure turbulence model. The oncoming wind was modelled according to the results obtained from 70 years of statistics analysis (from 1950-2021) of wind hourly data (streamwise and spanwise components). The in-teraction between wind flow and the Hera Lacinia column geometry shows very complex phenomenona. The adopted numerical model was able to simulate correctly the main phenomena involved such as the flow separation occurring around the column as well as the wake behind it. Particular attention was paid to investigating the most damaged areas of the column, identified by analysing recent images of the column, where the values of the time-averaged drag and lift forces were obtained. In order to obtain the erosion-based damage prediction future research will focus on the analysis of air flow erosion of the Hera-Lacinia column, starting from the measurements in situ of the main air characteristics and using the latter as the fluid for the numerical simulation, and by also considering different values of wind speed and directions.(c) 2023 Consiglio Nazionale delle Ricerche (CNR). Published by Elsevier Masson SAS. All rights reserved
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
An integrated approach for coastal risk assessment: traditional methodologies and social perception
No full textNel presente lavoro si propone un approccio innovativo per la valutazione del rischio costiero che integra un modello tradizionale basato sul modello Driver ‐ Pressures – States – Impacts ‐ Response (DPSIR) con la percezione del rischio da parte degli attori coinvolti nella gestione della fascia costiera e nelle attività che su di essa si sviluppano. Nello specifico, il coinvolgimento di stakeholder e policy makers viene analizzato attraverso il metodo Future Workshop e mediante sessioni di lavoro individuali complementari strutturate attraverso lʹutilizzo di mappe cognitive “fuzzy”. Il modello è applicato su un sito pilota situato a Margherita di Savoia nella regione Puglia (Sud Italia). I risultati mostrano come, attraverso l’utilizzo del modello DPSIR, sia possibile indentificare i siti maggiormente colpiti dai fenomeni di erosione e inondazione costiera a scala regionale, ma che gli indicatori fisici, soprattutto quelli legati all’esposizione, possono rappresentare solo in parte le problematiche esistenti a livello locale. Lʹapproccio integrato proposto in questo studio evidenzia la necessità di condurre studi più dettagliati per valutare il rischio a livello comunale includendo sia la modellazione analitico‐matematica dei processi fisici per la stima della vulnerabilità che la conoscenza esperienziale degli attori locali coinvolti nella valutazione dellʹesposizione. Dal confronto tra l’indice calcolato e il rischio percepito, emerge come nonostante imprenditori e amministratori locali siano ben consapevoli della storia dellʹarea, essi riconoscano soltanto in parte i processi attualmente in corso responsabili del degrado della fascia costiera. Lʹeccessivo sfruttamento della costa e l’antropizzazione incontrollata sono riconosciuti tra le principali cause dei processi erosivi ulteriormente aggravati dalle opere di difesa realizzate per contrastare l’arretramento della linea di riva. In linea con i risultati derivanti dall’applicazione del modello di rischio DPSIR, che mostra chiaramente processi erosivi notevoli a partire dal 1960, i rischi legati ai processi di erosione sono ben riconosciuti e percepiti dagli attori coinvolti, fondamentalmente per gli impatti negativi che questi hanno sulle attività economiche. Al contrario, non emerge il riconoscimento del rischio associato alle inondazioni, che invece colpiscono frequentemente lʹarea di studio, causando danni ingenti soprattutto alle attività agricole che si sviluppano
lungo la costa. Probabilmente, le inondazioni sono così strettamente associate allʹerosione costiera nella percezione comune, che gli attori locali ne associano le cause esclusivamente all’arretramento della spiaggia emersa, non considerando gli impatti negativi del cambiamento climatico in atto, che si traducono nell’innalzamento del l.m.m. e nel verificarsi più frequente di mareggiate intense, poiché difficilmente collocano la realtà locale in un contesto più globale.The paper presents an innovative approach for coastal risk assessment which integrates a traditional DPSIR index‐based model with social perception of risk. Specifically, stakeholder’s and policy makers’ engagement is considered by means of the Future Workshop method and complementary individual working sessions structured through the use of Fuzzy‐Cognitive Maps. The model is applied on a test
site located at Margherita di Savoia in Puglia region (South Italy). Results mainly show that DPSIR method allows to identify coastal erosion and flooding hot spots at the regional scale, but it cannot be
exhaustive for local contexts, especially when exposure is considered. The integrated approach proposed in this study highlights the need to do more detailed studies to assess risk at the municipal level both including mathematical modelling of the involved physical processes in vulnerability estimation and the experiential knowledge of local actors in exposure evaluation. Moreover, the analysis shows that, nevertheless local actors are aware of the history of the area, they partially recognize the processes currently ongoing. The excessive exploitation of the coast is recognized as one of the main causes of erosion processes further worsened by coastal protection structures. According to the DPSIR risk model, which clearly shows remarkable erosive processes from 1960, stakeholders and policy makers perceive the risk of coastal erosion for the test site, whereas they do not recognize the risk associated with flooding that instead frequently affects the study area. Probably floods are so closely associated with coastal erosion that local actors subsumed them into erosive processes. Also, climate change’s negative impacts are not perceived by the actors and it could be since they have difficulties placing the local reality in a more global context
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