1,721,168 research outputs found
Data-driven geological multi-hazard risk analysis at urban scale
No full textThis research work explores the intricate domain of geological multi-hazard risk assessment in urban environments, with a particular focus on the Municipality of Rome, Italy. By leveraging data-driven methodologies, advanced Machine Learning techniques, and open-access data, this study addresses the challenges posed by ground instability hazards, including landslides, subsidence, and sinkholes. The research offers valuable insights, innovative models, and practical applications, contributing to urban resilience enhancement and risk mitigation.
As the global trend of urbanization continues to transform landscapes and increase population concentration in cities, the understanding and management of geological hazards in urban areas have never been more critical. This research encompasses three key articles published within the thesis, to delve into geological multi-hazard risk analysis in the urban context.
In Chapter 2, we tackle the challenge of integrating fragmented, incomplete, and often unreliable data sources for landslide hazard assessment. Recognizing the crucial role of hazard evaluation in risk mitigation policies, we focused on making the most of available data. The methods employed include landslide inventory review, boosting the training dataset, and optimizing Machine Learning-based susceptibility analysis. The research explores temporal recurrence by analysing multi-temporal landslide inventories and historical rainfall databases, offering valuable insights into hazard probability. The integration of spatial and temporal attributes led to the creation of Rome's first large-scale landslide hazard product. This product, designed for statutory purposes, represents a significant milestone in improving the resilience of urban areas.
Chapter 3 delves into the world of Machine Learning techniques for landslide susceptibility mapping, emphasizing the significance of data quality. The study compared various models, with the ExtraTreesClassifier emerging as the most reliable choice. However, recognizing the rarity of high-quality, site-specific landslide inventories, the research examines the reliability of open-source landslide susceptibility maps at different spatial scales. By conducting a thorough statistical and spatial analysis, the research highlights the impact of mapping unit and analysis scale on prediction accuracy. Furthermore, the fusion of multiple low-resolution susceptibility maps is introduced, offering a promising approach to overcome data limitations. This milestone not only improves our understanding of landslide susceptibility mapping but also provides practical tools for large-scale assessments in urban environments.
The development of a novel model for multi-risk assessment takes centre stage in Chapter 4. The model's goal is to support decision-makers and risk managers in prioritizing buildings exposed to ground instability hazards, including landslides, subsidence, and sinkholes. By integrating spatial hazard assessments, satellite interferometric data, building characteristics, and asset market values, the model calculates a multi-risk score, enabling the ranking of urban buildings. The research offers a detailed explanation of how each dataset contributes to the overall risk assessment, from spatial hazard to potential economic damage and activity rates. The data harmonization process leads to a practical, semi-quantitative approach for multi-risk assessment, fostering a more proactive stance in mitigating ground instability hazards.
This Ph.D. work could bring relevant insights for geological multi-hazard risk assessment and urban resilience. Its findings lay the foundation for further research, fostering safer, more resilient cities worldwide
Poster P15: Excited states of molecular solutes with Quantum Monte Carlo: vertical transition and geometry optimization
No full textRecently, we have developed a novel Polarizable Continuum Model (PCM), which includes both surface and volume polarization of the dielectric medium (pure SVPE scheme), designed for the Quantum Monte Carlo (QMC) treatment of the solute. In particular, the treatment of volume polarization, due to quantum mechanical penetration of the solute charge density in the solvent domain, is based on quantum Monte Carlo techniques. The method allows to accurately solve Poisson's equation of the solvation model coupled with the Schrödinger equation for the solute [1,2,3]. The present model has been now extended to treat the effects of solvation in solute vertical electronic transitions and to the search of the solute equilibrium geometry in the excited states. For the first case, here we show the results of our study
performed on fast n → pi* and pi → pi* vertical transitions of s-trans- acrolein in water [4]. To perform calculations in a non-equilibrium solvation regime for the solute excited state, we have added a correction to the global dielectric polarization charge density, obtained self consistently with the solute ground-state wave function by assuming a linear-response scheme. The calculated solvatochromic shifts are properly described. For the second case, we start from recent
advances made to carry out the ground- and excited-state geometry optimization within QMC [5]. For the present purpose, we have extended the calculation of the forces to include solvent e_ects through our QMC implementation of PCM [6]. We show results, performed at the variational Monte Carlo level, on the excited-state geometry optimization of some small organic molecules in water solution and we make a comparison with the more widely used TDDFT and CASPT2 methods.
[1] C. Amovilli, C. Filippi, F. M. Floris, J. Phys. Chem. B (2006) 110 26225.
[2] C. Amovilli, C. Filippi, F. M. Floris, J. Chem. Phys. (2008) 129 244106.
[3] F. M. Floris, C. Filippi, C. Amovilli, J. Chem. Phys. (2012) 137 075102.
[4] F. M. Floris, C. Filippi, C. Amovilli, J. Chem. Phys. (2014) 140 034109.
[5] R. Guareschi, C. Filippi, J. Chem. Theor. Comput. (2013) 9 5513.
[6] R. Guareschi, F. M. Floris, C. Amovilli, C. Filippi, in preparation (2014)
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
FALESCE QUEI IN SARDINIA SUNT
No full textThe aim of this paper is the analysis of epigraphical and archaeological evidence of the spreading of Italic patterns in Sardinia during late republican age
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
Un anonimo funzionario equestre da Tarrhi: proposte per la ricostruzione di un testo
No full textUn piccolo frammento di marmo (AE, 1971,127), rinvenuto a Tarrhi, è attribuibile a un’iscrizione forse onoraria dedicata dagli abitanti della colonia a un personaggio di ordine equestre, del quale si riporta la carriera in ordine discendente. Suggestivo ma difficilmente dimostrabile il riferimento del testo a L. Valerius Datus, prefetto della flotta del Miseno e poi prefetto dei vigili durante il principato di CaracallaA small marble fragment (AE, 1971,127), found in Tarrhi is perhaps to be referred to a honorary inscription dedicated by the inhabitants of the colony to a member of the equestrian order, whose career is given in a descending order. Suggestive but difficult to prove that the text is attributable to L. Valerius Datus, praefectus classis Misenensis and then praefectus vigilum during the reign of the emperor Caracalla
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