333 research outputs found
The Accounting Network: how financial institutions react to systemic crisis
The role of Network Theory in the study of the financial crisis has been
widely spotted in the latest years. It has been shown how the network topology
and the dynamics running on top of it can trigger the outbreak of large
systemic crisis. Following this methodological perspective we introduce here
the Accounting Network, i.e. the network we can extract through vector
similarities techniques from companies' financial statements. We build the
Accounting Network on a large database of worldwide banks in the period
2001-2013, covering the onset of the global financial crisis of mid-2007. After
a careful data cleaning, we apply a quality check in the construction of the
network, introducing a parameter (the Quality Ratio) capable of trading off the
size of the sample (coverage) and the representativeness of the financial
statements (accuracy). We compute several basic network statistics and check,
with the Louvain community detection algorithm, for emerging communities of
banks. Remarkably enough sensible regional aggregations show up with the
Japanese and the US clusters dominating the community structure, although the
presence of a geographically mixed community points to a gradual convergence of
banks into similar supranational practices. Finally, a Principal Component
Analysis procedure reveals the main economic components that influence
communities' heterogeneity. Even using the most basic vector similarity
hypotheses on the composition of the financial statements, the signature of the
financial crisis clearly arises across the years around 2008. We finally
discuss how the Accounting Networks can be improved to reflect the best
practices in the financial statement analysis
Voting Behavior, Coalitions and Government Strength through a Complex Network Analysis
We analyze the network of relations between parliament members according to
their voting behavior. In particular, we examine the emergent community
structure with respect to political coalitions and government alliances. We
rely on tools developed in the Complex Network literature to explore the core
of these communities and use their topological features to develop new metrics
for party polarization, internal coalition cohesiveness and government
strength. As a case study, we focus on the Chamber of Deputies of the Italian
Parliament, for which we are able to characterize the heterogeneity of the
ruling coalition as well as parties specific contributions to the stability of
the government over time. We find sharp contrast in the political debate which
surprisingly does not imply a relevant structure based on establised parties.
We take a closer look to changes in the community structure after parties split
up and their effect on the position of single deputies within communities.
Finally, we introduce a way to track the stability of the government coalition
over time that is able to discern the contribution of each member along with
the impact of its possible defection. While our case study relies on the
Italian parliament, whose relevance has come into the international spotlight
in the present economic downturn, the methods developed here are entirely
general and can therefore be applied to a multitude of other scenarios.Comment: 6 pages, 4 figure
Report on Italian Research in Organic Food and Farming (2000–2005)
In Italy since the eighties, the scientific community opened a discussion on how to face many agricultural critical points, reconsidering old but renewed approaches to make agriculture more environment and consumer-friendly.
In 1988 the first coordinated project on OF&F (Biological and integrated control of crop and forest pest and disease) was financed by MIPAF, involving 46 researchunits (research centres and universities).
But it was only in the last decade that interest in organic farming really took off, when production methods continued to develop, along with consumers’ keen concern to be supplied with more wholesome, environment-friendly products. There was a major increase in the number of producers, and new initiatives got on the way for processing and marketing organic products.
Italy has become the European country with the largest cultivated surface (954,361 ha, including 246,318 ha under conversion from conventional to organic farming, in 2004). The total surface is mainly cultivated with forage crops and pastures (48 %); the rest is devoted to cereals (20 %), fruit tree, including vineyards and olive-tree (18 %), vegetables and industrial crops (4 %). These data refer to land cultivated under provision of EC Regulation 2092/91 and its modifications.
The gradual recognition of the organic farming potential to create a high added value food market and socio-economic benefits to farmers, producing positive effects on environment, public health, social and rural development and animal welfare as well, has driven the European Union and Italy to adopt specific legislation and promote research actions.
The following different European acts issued after the Council Regulation 2091/92, have all recognized organic farming as a strategic tool to realize a sustainable development of European society: the Council Regulation EC 1257/1999 supporting rural development; the EU Commission Strategy for Sustainable Development in 2001, the Sixth Community Environment Action Programme in 2002 and, finally, the mid-term review of the Common Agricultural Policy in 2003.
The European Action Plan for Organic Food and Farming (OF&F Plan) has been issued in June 2004, strongly supported by Italy during its EU chairing semester (June-December 2003). This document aims “to assess the situation and to lay down the basis for policy development in the coming years, thereby providing an overall strategic vision for organic farming’s contribution to the common agricultural policy (CAP)”. The Commission recognizes the dual key role of OF&F in food market and land management and the importance of research on organic farming and processing methods to exploit this potential (Action 7). Therefore, an important part of the country’s policies aimed at developing the organic sector has been addressed to strengthen research and training at different levels, adopting specific research programmes and farmers training to ensure the innovation transfer into agricultural practice with close cooperation among researchers, advisory services, farmers and the food production chain.
As other Member States and Regions, Italy has adopted a national Action Plan on OF&F research in 2002. The Action Plan was devoted mainly to the development of organic farming, focusing on agro-environmental programmes, market development, research and production capacity building.
In December 2005, a new National Strategic Plan on OF&F has been approved which does not
include specific research priorities, but is a reference framework of actions to strengthen the whole OF&F production chain
Credit default swaps networks and systemic risk
Credit Default Swaps (CDS) spreads should reflect default risk of the underlying corporate debt. Actually, it has been recognized that CDS spread time series did not anticipate but only followed the increasing risk of default before the financial crisis. In principle, the network of correlations among CDS spread time series could at least display some form of structural change to be used as an early warning of systemic risk. Here we study a set of 176 CDS time series of financial institutions from 2002 to 2011. Networks are constructed in various ways, some of which display structural change at the onset of the credit crisis of 2008, but never before. By taking these networks as a proxy of interdependencies among financial institutions, we run stress-test based on Group DebtRank. Systemic risk before 2008 increases only when incorporating a macroeconomic indicator reflecting the potential losses of financial assets associated with house prices in the US. This approach indicates a promising way to detect systemic instabilities
The structural intervention of St. Torcato Church : documentation and analysis of the strengthening works
Dissertação de mestrado em Structural Analysis of Monuments and Historical ConstructionsThe church of São Torcato represents a masterpiece of the carving skills of Minho craftsmen. However,
the arise of several structural anomalies of medium and high intensity, identified since 1976, prompted
the beginning of a careful examination of the building that is still ongoing. The aim of this thesis is the
retracing of the subsequent investigation steps that were able to identify the causes of the problems,
the discussion on the strengthening works planned on the building and the relative assessment of the
eventual harm induced by the intervention.
The steps that have been followed for this discussion had started from the historical framework of the
church construction, in order to understand how such phases could have trigged the damage phenomena.
Subsequently, all the monitoring systems and surveys have been listed in order to understand the
logical steps that have been followed to estimate the causes of such problems. The relative strengthening
program has been discussed and cross-checked in all its aspect in order to evaluate a possible
enhancement on the design. A minor design has been carried out as response of a new demand of the
institution involved in the conservation of the building: the replacement of the crosses on top of both
spires. Finally, the data of the static monitoring system placed on the tower since 2009 was analyzed
and confronted to the actual situation, in order to evaluate the presence of interference with the structure
induced by the executive works.
From the analysis of the previous investigations it was possible to build a complete picture of the mechanical
characteristics of the church and the causes which trigged the existent damage phenomena.
Furthermore, it was possible to understand the level of activity of the damage and the effectiveness of
the system of interventions that was designed in order to face the problems of the church. A cross-check
on such interventions confirmed its reliability and enhanced as much as possible its defective parts.
The analysis of the cross was satisfying except for one of the mathematical models, which should be
improved after specific studies of the roof element.
The future tasks will have to take into account the effective development of the intervention works and
the comparison with both static and dynamic monitoring data. It is also necessary to perform more specific
computational analysis regarding the mechanical behavior of the building considering cracked models
and FEM that contemplate both settlement and thermal condition at the same time. Furthermore,
several direct tests should be carried on the intervention wastes (such as coring samples) in order to
evaluate the reliability of the non-destructive tests performed on the structure.O Santuário de São Torcato representa a obra-prima em cantaria granito de toda a região do Minho.
Todavia, devido Ă existĂŞncia de um conjunto de anomalias estruturais de severidade moderada a severa
foi necessário realizar um estudo de inspeção e diagnostico, que culminou na elaboração de um
projeto de reforço, cujos trabalhos para a estabilização das fundações das torres estão precisamente
em curso.
O objetivo da presente dissertação é de registar e analisar as diferentes fases de investigação que
permitiram a identificação das anomalias e as suas causas, o acompanhamento da obra em curso,
incluindo a validação e controlo da intervenção em curso através da monitorização estrutural.
A dissertação começou com a análise histórica da construção do santuário, a fim de compreender se
o processo construtivo introduziu dano. Posteriormente, todas as inspeções, diagnósticos e monitorizações
estruturais realizadas foram apresentadas para melhor se compreender como se determinaram
as causas dos problemas estruturais. A intervenção de reforço estrutural foi discutida sobre todos
os seus aspetos e também foi realizada uma análise para a substituição das cruzes no topo das duas
torres, uma vez que estas se encontram muito deterioradas. Finalmente, os dados do sistema de monitorização
estático, instalado desde 2009, foram analisados e confrontados com a situação atual (no
decorrer de trabalhos de reforço), com o objetivo de avaliar o impacto da intervenção na construção e
se, eventualmente,
AtravĂ©s da análise dos anteriores estudos foi possĂvel determinar as caracterĂsticas mecânicas/estruturais
do santuário e as causas que levaram ao aparecimento das anomalias existentes. Foi também
possĂvel compreender o nĂvel de atividade das anomalias e a assertividade da intervenção estrutural
proposta para a estabilização das mesmas. A verificação da conformidade do projeto reafirmou a sua
necessidade e permitiu melhorar a eficiência de algumas das medidas de intervenção. A análise da
substituição das cruzes foi satisfatória, com a exceção de um dos modelos que deverá ser aprofundada
para melhor avaliar a sua estabilidade.
Como tarefas futuras propõem-se a continuidade do acompanhamento dos trabalhos de intervenção
e da análise dos dados dos sistemas de monitorização estático e dinâmico, quer durante, quer depois
da intervenção. TambĂ©m será necessária a realização de análises numĂ©ricas mais especĂficas sobre
o comportamento mecânico do edifĂcio considerando o tanto dano devido aos assentamentos da
fundação, como o efeito da variação térmica na construção. Além disso, vários ensaios deverão ser
realizados sobre os materiais sobrantes da intervenção (tais como os tarolos de carotagem), a fim de
validar a confiabilidade dos ensaios nĂŁo destrutivos realizados na estrutura.La chiesa di San Torcato rappresenta un capolavoro nel paesaggio architettonico di GuimarĂŁes, emblema
delle altissime capacità delle maestranze locali. Infelicemente, l’insorgere d’innumerevoli anomalie
di moderata ed elevata intensità ha richiesto esami dettagliati dell’edificio, avviati alla fine degli anni
settanta e protratti continuativamente fino ad oggi.
L’obiettivo di questa tesi e la riproposizione delle varie investigazioni che hanno permesso di identificare
i fattori scatenanti dei danni dell’edificio, la discussione dei lavori di rinforzo pianificati per sopperire a
tali problematiche e la verifica dell’eventuale alterazione della struttura indotta dall’esecuzione dell’intervento.
La trattazione del tema è iniziata dalla ricostruzione del processo evolutivo della chiesa, così da relazionare
l’edificio al suo complesso quadro storico. Successivamente, tutti i sistemi di monitoraggio utilizzati
e le indagini eseguite sono stati organizzati e descritti, in modo da ripercorrere il lungo processo
logico che ha portato alla scoperta delle cause dei problemi attuali. L’intervento è stato discusso e
vagliato da un attento calcolo, così da individuare e migliorare eventuali punti carenti del programma.
Un progetto minore è stato eseguito personalmente come richiesto dall’istituzione coinvolta nella conservazione
dell’edificio: la sostituzione delle croci sulla sommità dei campanili. Infine, i dati ricavati dai
sistemi di monitoraggio statici, installati dal 2009 sono stati analizzati e confrontati con la situazione
attuale, in modo da poter riscontrare la presenza di un eventuale danno indotto dai lavori.
Dalle analisi delle precedenti investigazioni è stato possibile ricostruire il quadro completo delle caratteristiche
meccaniche dell’edificio e delle cause che hanno scatenato gli attuali fenomeni di decadimento.
Inoltre, è stato possibile conoscere il livello di attività del danno e l’efficienza del sistema d’interventi
pianificato. Una verifica incrociata di tale progetto ne ha confermato l’affidabilità , ed ha permesso di
migliorare il più possibile le sue prestazioni. L’analisi della croce è stata soddisfacente ad esclusione di
uno dei modelli matematici utilizzati: tale schema dovrebbe essere migliorato a seguito di esami specifici
sugli elementi decorativi.
I compiti futuri dovranno prevedere l’analisi dell’effettivo sviluppo dei lavori esecutivi e lo studio incrociato
con i dati dei sistemi di monitoraggio sia dinamici sia statici. SarĂ inoltre necessario eseguire
analisi computazionali piĂą specifiche che tengano conto della reale mappa dei danni, oltre che modelli
a elementi finiti dell’edificio che contemplino l’azione congiunta dei cedimenti differenziali del suolo e
delle variazioni termiche. Inoltre, test distruttivi dovrebbero essere sviluppati sui preziosi scarti delle esecuzioni
(come ad esempio i carotaggi delle torri) così da valutare l’affidabilità dei ND-test eseguiti sulla
struttura e aggiornare le sue caratteristiche meccaniche
Note of the COASTAL AND MARINE GEOMORPHOLOGICAL MAP Island of San Pietro (SW Sardinia) Scale 1:25.000
Nel presente lavoro vengono descritti i caratteri geomorfologici e strutturali dell’area
marina ed insulare dell'Isola di San Pietro (Sardegna SW).
Nonostante la limitata estensione, di poco più di 50 km2 di superficie, l’Isola è caratterizzata
da una elevata geodiversitĂ , legata alla presenza di numerose formazioni e ben riconoscibili
tipi di rocce vulcaniche, laviche (rioliti, ignimbriti, ignimbriti riolitiche, comenditi,
diaspri, ecc.) e tufacee (tufi, piroclastiti cineriti, cineriti pomicee, ocre rosse e gialle),
riferibili al ciclo calcoalcalino oligo-miocenico.
I processi geomorfologici legati alle acque, all’alterazione meteorica, al vento ed alla dinamica
litorale hanno generato forme interne (tafoni, sculture alveolari, drappeggi, forme a
fungo, valli sospese, ecc.) e soprattutto costiere (insenature a rias, scogliere, isolotti,
colonne e pinnacoli, grotte costiere), talora dai connotati spettacolari quali duomi (Capo
Sandalo, Cala Fico, ecc.), mineralizzazioni manganesifere, strutture di flusso (lave commenditiche
di Bricco di Nasca e Montagna di Ravenna), convolute (lave commenditiche
di Cala Fico) e fessurazioni colonnari.
Dettagliate ricerche sul campo e analisi di laboratorio condotte utilizzando le fotografie
aeree, le ortofotocarte e le immagini satellitari, hanno permesso di esaminare e classificare
le morfologie riconducibili ai processi geomorfologici associati all'azione degli agenti
esogeni e delle forze endogene.
L’interpretazione geologico-geomorfologica del settore marino è stata condotta principalmente
attraverso lo studio dei dati Side Scan Sonar supportati dalle osservazioni dirette
effettuate durante i rilievi in immersione. Per le aree pericostiere (tra 0 e -15 m) sono
stati analizzati i fotogrammi e le immagini satellitari di recente acquisizione. Tale procedura, associata alle osservazioni dirette raccolte in immersione, ha consentito di determinare la litologia degli affioramenti rocciosi sommersi, di ricostruire i limiti tra litotipi differenti, di rilevare le evidenze di lineamenti tettonici, di rilevare lo stato evolutivo delle
forme del rilievo costiero e sottomarino, di rilevare le principali facies sedimentarie e di
riconoscere evidenze di stazionamento del livello marino (paleolinee di riva). I rilievi e le
verifiche in immersione sono stati finalizzati alla validazione delle ipotesi interpretative
dei dati geofisici Side Scan Sonar. Le attivitĂ di interpretazione sono state condotte in
ambiente CAD e GIS mentre la restituzione finale è stata ottenuta tramite software di grafica
vettoriale.The Island of San Pietro, situated on the SW coast of Sardinia, covers an area of
roughly 51 square kilometres. Geologically, the island is composed almost entirely of
volcanic rock, with minor outcrops of Tyrrhenian fossil-bearing sandy conglomerates,
of eolian sandstones, ancient and recent alluvial deposits, dunal sands and sediments
deposited in palustrine and marshy environments.
In spite of its small size, the island boasts a wealth of geodiversity, with the occurrence
of a variety of effusive magmatic rocks formed during the Oligo-Miocene volcanic
cycle that affected the whole of Sardinia. During this cycle numerous units were
emplaced as well as various, easily distinguishable types of volcanic rocks, namely
lava (rhyolite, rhyolitic ignimbrite, comendite, retinite, diaspore, etc.) and tuff (tuff,
pyroclastite, cinerite, pumiceous cinerite, red and yellow ochre), sometimes with spectacular
domes (for instance at Capo Sandalo and Cala Fico) manganese bearing mineralizations,
emission centres, lava flow surface structures (comendite lava at Bricco
di Nasca and Montagna di Ravenna), convolute flow structures (comendite lava at
Cala Fico) and spectacular columnar fracturing.
Detailed field surveys and laboratory investigations conducted using aerial photographs,
orthophotographs and satellite images allowed to examine and classify those
landforms attributable to geomorphological processes associated with water, weathering,
wind and coastal dynamics.
The marine environment was geologically-geomorphologically interpreted chiefly by
examining the Side Scan Sonar data, supplemented with direct observations during
underwater surveys. For the pericoastal areas (between 0 and -15 m), photograms and
recently acquired satellite imagery were analysed. Side scan sonograms together with
direct underwater observations were used to determine lithology of submerged rock
outcrops, to reconstruct boundaries between different rock types, to detect evidence of
tectonic lines, to determine the evolution of coastal and underwater relief forms, to
identify the main sedimentary facies and evidence of sea level stand (palaeo shore
line). Interpretive hypothesis of the side scan sonar data were validated by means of
underwater surveys.
Data from land and sea surveys were interpreted in CAD and GIS environments, while
final rendering was obtained using vector graphics software
Tweet-tales: moods of socio-economic crisis?
The widespread adoption of highly interactive social media like Twitter, Facebook and other platforms allow users to communicate moods and opinions to their social network. Those platforms represent an unprecedented source of information about human habits and socio-economic interactions. Several new studies have started to exploit the potential of these big data as fingerprints of economic and social interactions.
The present analysis aims at exploring the informative power of indicators derived from social media activity, with the aim to trace some preliminary guidelines to investigate the eventual correspondence between social media indices and available labour market indicators at a territorial level. The study is based on a large dataset of about 4 million Italian-language tweets collected from October 2014 to December 2015, filtered by a set of specific keywords related to the labour market. With techniques from machine learning and user’s geolocalization, we were able to subset the tweets on specific topics in all Italian provinces. The corpus of tweets is then analyzed with linguistic tools and hierarchical clustering analysis. A comparison with traditional economic indicators suggests a strong need for further cleaning procedures, which are then developed in detail. As data from social networks are easy to obtain, this represents a very first attempt to evaluate their informative power in the Italian context, which is of potentially high importance in economic and social research
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