1,702 research outputs found
A Florentine family in crisis: the Strozzi in the fifteenth century.
No full textPhDIn 1434 the Strozzi lineage had held a leading position in
Florentine society and government for at least one hundred and fifty
years, and was one of the largest and wealthiest of the city's
patrician lineages. The records of the catasto of 1427 and of the
scrutiny of 1433 are used to give a profile of the dominant social,
economic and political position of the Strozzi before the advent of
Medicean dominance. Their record of electoral success, and the
political and cultural leadership of influential and respected men
such as Palla di Nofri and Matteo di Simone, with other factors, put
the Strozzi amongst the greatest enemies of the victorious Medicean
regime of late 1434. The effects of political opposition and exile
on the lineage are examined both directly, through records of office-holding,
and indirectly through such indicators as marriage alliances
and household wealth. The two most prominent lines of the Strozzi
were exiled after 1434. Palla di Nofri's life and preoccupations in
his Paduan exile are examined, together with the lives of his sons;
none of these Strozzi ever returned to Florence, pursued as they were
by the enmity of the Medicean regime. The very different careers of
Filippo di Matteo and his brother Lorenzo are also examined: how they
succeeded in founding a lucrative bank in Naples, and in returning to
Florence to 'rebuild' (rifare) the position of the Strozzi lineage
there. The final decades of the century saw the Strozzi in an
economically more secure position, due substantially to the efforts
of Filippo. Except for a very small number of its members admitted
into the regime, most of the lineage is here shown to have remained
excluded from significant political office until after the fall of
the Medici regime in 1494
Selected letters of Alessandra Strozzi
No full textThe letters of Alessandra Strozzi provide a vivid and spirited portrayal of life in fifteenth-century Florence. Among the richest autobiographical materials to survive from the Italian Renaissance, the letters reveal a woman who fought stubbornly to preserve her family's property and position in adverse circumstances, and who was an acute observer of Medicean society. Her letters speak of political and social status, of the concept of honor, and of the harshness of life, including the plague and the loss of children. They are also a guide to Alessandra's inner life over a period of twenty-three years, revealing the pain and sorrow, and, more rarely, the joy and triumph, with which she responded to the events unfolding around her.This edition includes translations, in full or in part, of 35 of the 73 extant letters. The selections carry forward the story of Alessandra's life and illustrate the range of attitudes, concerns, and activities which were characteristic of their author
Nonlinear Resonance Interaction between Conjugate Circumferential Flexural Modes in Single-Walled Carbon Nanotubes
No full textThis paper presents an investigation on the dynamical properties of single-walled carbon nanotubes (SWCNTs), and nonlinear modal interaction and energy exchange are analysed in detail. Resonance interactions between two conjugate circumferential flexural modes (CFMs) are investigated. The nanotubes are analysed through a continuous shell model, and a thin shell theory is used to model the dynamics of the system; free-free boundary conditions are considered. The Rayleigh–Ritz method is applied to approximate linear eigenfunctions of the partial differential equations that govern the shell dynamics. An energy approach, based on Lagrange equations and series expansion of the displacements, is considered to reduce the initial partial differential equations to a set of nonlinear ordinary differential equations of motion. The model is validated in linear field (natural frequencies) by means of comparisons with literature. A convergence analysis is carried out in order to obtain the smallest modal expansion able to simulate the nonlinear regimes. The time evolution of the nonlinear energy distribution over the SWCNT surface is studied. The nonlinear dynamics of the system is analysed by means of phase portraits. The resonance interaction and energy transfer between the conjugate CFMs are investigated. A travelling wave moving along the circumferential direction of the SWCNT is observed
A perspective on early detection systems models for COVID-19 spreading
No full textThe ongoing COVID-19 epidemic highlights the need for effective tools capable of predicting the onset of infection outbreaks at their early stages. The tracing of confirmed cases and the prediction of the local dynamics of contagion through early indicators are crucial measures to a successful fight against emerging infectious diseases (EID). The proposed framework is model-free and applies Early Warning Detection Systems (EWDS) techniques to detect changes in the territorial spread of infections in the very early stages of onset. This study uses publicly available raw data on the spread of SARS-CoV-2 mainly sourced from the database of the Italian Civil Protection Department. Two distinct EWDS approaches, the Hub-Jones (H&J) and Strozzi-Zaldivar (S&Z), are adapted and applied to the current SARS-CoV-2 outbreak. They promptly generate warning signals and detect the onset of an epidemic at early surveillance stages even if working on the limited daily available, open-source data. Additionally, EWDS S&Z criterion is theoretically validated on the basis of the epidemiological SIR. Discussed EWDS successfully analyze self-accelerating systems, like the SARS-CoV-2 scenario, to precociously identify an epidemic spread through the calculation of onset parameters. This approach can also facilitate early clustering detection, further supporting common fight strategies against the spread of EIDs. Overall, we are presenting an effective tool based on solid scientific and methodological foundations to be used to complement medical actions to contrast the spread of infections such as COVID-19
Hoop stresses in the con-rod small end
No full textHaving in mind con-rods for motorbike and car engines, and spurred by the disagreements evidenced in the pertinent literature, the maximum circumferential stresses within the small end are investigated analytically, photoelastically, and numerically. The analytical models are based upon a plane assumption, and they adopt both beam and theory of elasticity idealizations. The plane photoelastic study concentrates on small ends with outer to inner radii ratios ranging from 1.2 to 1.5. A plane numerical model aimed at thoroughly mimicking the pin ovalization is developed, and a design chart of the peak hoop stress within the small end is provided for a wide spectrum of small end and pin geometries, for zero initial clearance. Such diagrams allow a prompt preliminary dimensioning of the small end to be carried out, which may be refined by effecting a three-dimensional finite element study of the specific conrod geometry. The consequences of an initial clearance between small end bore and gudgeon pin are examined for selected geometries, and three-dimensional aspects are explored for specific con-rod shapes
Supply chain risk management: a new methodology for a systematic literature review
No full textPurpose perspective and as a research area. Given the relevance of the topic, the aim of the present paper is to present a focused literature review, investigating the process of knowledge creation, transfer and development from a dynamic perspective within the context of SCRM.– Supply chain risk management (SCRM) has recently gained increasing attention in the supply chain context, both from the practitioners’ Design/methodology/approach literature review approach to identify the most relevant articles to be included in the study with the citation network analysis in order to unfold the dynamics of the field under study. The authors define this new methodology as systematic literature network analysis.– A review of the literature on SCRM was undertaken. The new proposed methodology combines the systematic Findings identified and, by analysing the evolution over time of key concepts, a number of research directions were identified and discussed.– The paper demonstrates that there are a number of key themes in the field of SCRM. The contributions that influenced the field were Research limitations/implications moving and thus the recognition of streams of research that appear most promising. However, the application of the research methodology, and in particular of the citation network analysis, requires the support of specific computer programs. Moreover, the underlying assumption of the citation network analysis is that, by analysing the network of citations made to and from articles, it is possible to explain the flows of knowledge used to generate new results. This is only partially true since the spread of measures based on impact assessment led many researchers to an excessive use of citations, even if their content is not always decisive for the outcome of their work.– The dynamic nature of current literature review allows the identification of the directions in which research is Practical implications Furthermore from the evidence of the performed literature review some managerial insights can be derived on how to manage supply chain risk: by considering uncertainty in the design of supply chains, by understanding the impact of risks arising from network collaboration and interactions between supply chain partners, by developing proactive mitigation capabilities to hedge the increasing level of risk.– The present paper outlines a research agenda that may facilitate the development of models for managing supply chain risk. Originality/value of a dynamic perspective in order to analyse theory development.– The novelty of this research lies in the combination of two existing methodologies for reviewing the literature and in the adoptio
VENEZIA SUBSIDENCE MONITORING SERVICE IN THE LAGOON OF VENICE FOR REGIONAL ADMINISTRATIVE AND WATER AUTHORITIES DATA USER PROGRAMME (DUP), II PERIOD Executive Summary
No full textThe scope of the project “VENEZIA - Subsidence monitoring service in the Lagoon of Venice for regional administrative and water authorities” was to define and implement a land subsidence monitoring service in the Lagoon of Venice for regional and administrative authorities. In order to provide the best knowledge of the land subsidence process around the Lagoon of Venice, SAR-based monitoring techniques (differential SAR interferometry and interferometric point target analysis) were integrated with levelling and GPS surveys into an overall information system.
Land subsidence due to natural and anthropogenic causes has represented one of the most serious environmental problems for the Lagoon of Venice and its catchment (Tosi et al., 2002, Carbognin and Tosi, 2003, Carbognin et al., in press). Land subsidence has increased the vulnerability and the geological hazard (i.e. river flooding, riverbank stability, intrusion of seawater in the aquifer system, deteriorating of the littoral sectors with a general coastline regression and an increment of the sea bottom slope close to the shoreline) of these areas, a large portion of which lies below the mean sea level. After the regulation of groundwater exploitation from the Venetian aquifer-aquitard system, a remarkable slowing down of the induced subsidence in Marghera (industrial zone), in the historical center of Venice and along the littorals was ascertained in the 1970’s. Recent studies (Carbognin and Tosi, 2003) have shown that land subsidence is still in progress in the southern and northern coastal areas and in the nearby mainland, where groundwater is extracted from artesian wells, thicker and more compressible Holocene sediments are present, and organic soil oxidation takes place in reclaimed areas.
Until 1999, levelling of the Venice region was carried out only along the coast and the lagoon edges and the monitoring network was composed by benchmarks along single levelling lines; a fine grid network was established only in the city of Venice. In recent years, the levelling network has been updated to cover all the southern part of the Lagoon, and plans exist to cover also the northern sector. The same network used for the levelling surveys is also considered for differential GPS measurements. In addition to these ground-based methods, differential SAR interferometry using long series of SAR data (Wegmüller and Strozzi, 1998; Strozzi et al, 2001) and interferometric point target analysis (IPTA) (Wegmüller et al., 2003, Werner et al., 2003) have emerged as very promising tools for the monitoring of land subsidence at high spatial resolution.
The VENEZIA project was organized along a service definition phase, a service implementation phase and a service quality assessment phase. Important elements of the project were the definition, implementation and validation of the service for interferometric point target analysis and the integration of the SAR-based monitoring techniques with levelling and GPS surveys into an overall information system capable to provide the best knowledge of the subsidence process to the authorities that manage the Po Plain area around the Lagoon of Venice.Gamma Remote Sensing; Istituto di Scienze Marine - Consiglio Nazionale delle Ricerche; ESA-ESRINPublished6A. Monitoraggio ambientale, sicurezza e territorioope
Analysing the attractiveness, availability and accessibility of healthcare providers via social network analysis (SNA)
No full textDue to the increasing pressure on resource limitations and the need for efficiency improvements, effective healthcare service planning should analyse trends in citizens’ demand for healthcare services, as well as patients’ choices of healthcare providers, which are determined not only by prestige, but also by physical accessibility and availability. The main objective of the present study is to explore the benefits of adopting the social network analysis (SNA) approach to investigate the determinants of a patient's choice of healthcare provider as a way to support better resource allocation decisions in healthcare systems. For the purpose of the analysis, administrative data was used to track the flow of patients within orthopaedic departments of the Lombardy region (Italy) in 2014. A network was developed with two types of nodes: those of orthopaedic departments in the regional hospitals (114 nodes), and those of municipalities (5092 nodes). Using the Louvain algorithm, the communities and sub-communities were determined on the basis of patients’ choices, without any prior geographical considerations or planned catchment areas. Traditional SNA measures and other novel indicators, specifically developed for this study, were applied: in particular, attractiveness (i.e. the preference that patients assign to a certain department against the others available in the same reference area) and confinement (of demand) (i.e. the degree of the unique use of a certain department). A decision support matrix based on these indicators was defined for decision makers to use in evaluating department profiles, and optimizing the location of services and allocation of resources, while preserving accessibility to care and patients’ preferences. The decision support matrix was also evaluated on the basis of real practice and decisions made by regional healthcare managers
On Developing Tangible Interfaces for Video Streaming Control: a Real Case Study
No full textThis paper presents a novel tangible user interface for the dynamic control and manipulation of multiple video streams. Streams can be activated, triggered and managed based on the physical use of markers attached to cubes on a table top, whose movement is recognized by a camera placed on top of the working area. Markers can be associated to a single video stream, as well as a group of streams. Videostreams can be played out, paused, stopped, put in foreground, maximized or minimized, thanks to the use of our tangible interface; audio volumes of different streams can be controlled. Needless to say, streams can be distributed at different servers, or dynamically generated at distributed nodes in real-time. We claim that such an interface results as quite intuitive and easy-to-use, and can be employed in several videostreaming-based application domains, such as tele-conferencing, video-on-demand, video mixing. Results coming from an experimental assessment confirm the viability of our approach
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