andrea rapisarda - Academia.edu (original) (raw)
Papers by andrea rapisarda
Nuclear Physics, Mar 1, 1993
We report here on the measurements of one-particle transfer cross sections and quasi-elastic scat... more We report here on the measurements of one-particle transfer cross sections and quasi-elastic scattering of 32S+64Ni at energies around and well below the Coulomb barrier. The experiment has been performed with the Legnaro Recoil Mass Spectrometer. We have measured the excitation function at 0era = 170 ° from Ejab = 68.3 to 92.4 MeV and the angular distribution at Elab = 81.3 MeV from 0cm = 120 ° to 170 °. The results have been analysed in the framework of the complex WKB theory and the semiclassical approach based on Coulomb trajectories.
PLOS ONE
It is a widespread belief that success is mainly due to innate qualities rather than external for... more It is a widespread belief that success is mainly due to innate qualities rather than external forces. This is particularly true in sports competitions, where individual talent is usually considered the main, if not the only, ingredient to reach success. In this study, we explore the limits of this belief by quantifying the relative weight of talent and chance in fencing, a combat sport involving a weapon, with the help of both real data and agent-based simulations. Fencing competitions are structured as direct elimination tournaments, where randomness is explicitly present in some rules. We focused on épée, which is one of three disciplines. We collected data on international competition results and annual rankings, in the range 2008–2020, for male and female fencers under 20 years old (Junior category). Then, we built the model calibrated on our dataset and parametrized by just one free variable a, describing the importance of talent—and, consequently, of chance—in competitions (a ...
Frontiers in Physics
The rise of disinformation in the last years has shed light on the presence of bad actors that pr... more The rise of disinformation in the last years has shed light on the presence of bad actors that produce and spread misleading content every day. Therefore, looking at the characteristics of these actors has become crucial for gaining better knowledge of the phenomenon of disinformation to fight it. This study seeks to understand how these actors, meant here as unreliable news websites, differ from reliable ones. With this aim, we investigated some well-known fake and reliable news sources and their relationships, using a network growth model based on the overlap of their audience. Then, we peered into the news sites’ sub-networks and their structure, finding that unreliable news sources’ sub-networks are overall disassortative and have a low–medium clustering coefficient, indicative of a higher fragmentation. The k-core decomposition allowed us to find the coreness value for each node in the network, identifying the most connectedness site communities and revealing the structural org...
It is a widespread belief that success is mainly due to innate qualities, rather than to external... more It is a widespread belief that success is mainly due to innate qualities, rather than to external forces.This is particularly true in sport competitions, where individual talent is usually considered the main, if not the only, ingredient in order to reach success. In this study, with the help of both real data and agent-based simulations, we explore the limits of this belief by quantifying the relative weight of talent and chance in fencing, a combat sport involving a weapon. Fencing competitions are structured as direct elimination tournaments, where randomness is explicitly present in some rules. Our dataset covers the last decade of international events and consists of both single competition results and annual rankings for male and female fencers under 20 years old (Junior category). Our model is calibrated on the dataset and parametrized by just one free variable 'a' describing the importance of talent - and, consequently, of chance - in competitions (a = 1 indicates th...
Frontiers in Physics, 2021
In early January 2020, after China reported the first cases of the new coronavirus (SARS-CoV-2) i... more In early January 2020, after China reported the first cases of the new coronavirus (SARS-CoV-2) in the city of Wuhan, unreliable and not fully accurate information has started spreading faster than the virus itself. Alongside this pandemic, people have experienced a parallel infodemic, i.e., an overabundance of information, some of which is misleading or even harmful, which has widely spread around the globe. Although social media are increasingly being used as the information source, web search engines, such as Google or Yahoo!, still represent a powerful and trustworthy resource for finding information on the Web. This is due to their capability to capture the largest amount of information, helping users quickly identify the most relevant, useful, although not always the most reliable, results for their search queries. This study aims to detect potential misleading and fake contents by capturing and analysing textual information, which flow through search engines. By using a real-...
Research in Transportation Economics, 2019
Limiting private cars' use while promoting sustainable modes of transport is one of the main chal... more Limiting private cars' use while promoting sustainable modes of transport is one of the main challenges of urban transport planning. In this context, characterized by scarce resources and increasing demand for mobility, Demand Responsive Shared Transport (DRST) services can bridge the gap between shared low-quality public transport and unsustainable individual private transport. Taking advantage of Information and Communication Technologies (ICT), they can supply transport solutions ranging from flexible transit to ride sharing services, providing real-time "on demand" mobility through fleets of vehicles shared by different passengers. The optimal design of a DRST service requires a trade-off among efficiency (from the operators' point of view), service quality (from the users' point of view) and sustainability (from the community's point of view). In this paper, an agentbased model (ABM) fed with GIS data is used to explore different system configurations of a specific type of DRST service, i.e. flexible transit, and to estimate the transport demand and supply variables that make the service feasible and convenient. The model reproduces a mixed fixed/flexible route transit service with different fleet size and vehicle capacity in the city of Ragusa (Italy) with the aim to: (i) make a first test of the ABM model with GIS-based demand and road network models; (ii) explore different vehicle dispatching strategies; (iii) find appropriate indicators to monitor the service quality and efficiency. Simulation results show the impact of fleet composition and route choice strategy on the system performance. In particular, they show an optimal range of operating vehicles that minimizes a total unit cost indicator, accounting both for passenger travel time and vehicle operation cost. By reproducing the microinteraction between demand and supply agents (i.e. passengers and vehicles), it is possible to monitor the macroscopic behaviour of the system, and derive useful suggestions for the correct planning, management and optimization of DRST services.
AIP Conference Proceedings, 2007
We analyze the role of the correlated fluctuations, with a correlation time T^, in the dynamics o... more We analyze the role of the correlated fluctuations, with a correlation time T^, in the dynamics of an overdamped Josephson junction in the presence of a periodic driving signal.
AIP Conference Proceedings, 2007
ABSTRACT
In this paper we present experimental results concerning Acoustic Emission (AE) recorded during c... more In this paper we present experimental results concerning Acoustic Emission (AE) recorded during cyclic compression tests on two different kinds of brittle building materials, namely concrete and basalt. The AE inter-event times were investigated through a non-extensive statistical mechanics analysis which shows that their decumulative probability distributions follow q-exponential laws. The entropic index q and the relaxation parameter q 1=Tq, obtained by fitting the experimental data, exhibit systematic changes during the various stages of the failure process, namely (q; Tq) linearly align. The Tq = 0 point corresponds to the macroscopic breakdown of the material. The slope, including its sign, of the linear alignment appears to depend on the chemical and mechanical properties of the sample. These results provide an insight on the warning signs of the incipient failure of building materials and could therefore be used in monitoring the health of existing structures such as building...
Individual sports competitions provide a natural setting for examining the relative importance of... more Individual sports competitions provide a natural setting for examining the relative importance of talent and luck in achieving success. The belief that success is primarily due to individual abilities and hard work rather than external factors is especially strong in this context. Thus, individual talent is regarded as the most important – if not the only – component in ensuring a successful career for players. In this study, we test this belief through detailed data analysis and comparison with an agent-based model, using tennis as a case study due to its popularity and competition structure in direct-elimination tournaments. Our dataset covers the last decade (2010-2019) of main international events in the ATP circuit and consists of tourney results and annual rankings for professional male players. We show that our agent-based model, calibrated on the dataset, can reproduce the main stylized facts observed in real data, including the results of single tournaments and the developm...
arXiv (Cornell University), Dec 12, 2017
In this paper we discuss the problems of modern representative democracy and we look at the selec... more In this paper we discuss the problems of modern representative democracy and we look at the selection of legislators by lot as a way to tame some of the drawbacks of that system. It is recalled at the beginning that resorting to sortition for the selection of public officers used to be a popular way of taming factionalism in public affairs. Factionalism is assumed to be detrimental to public affairs as public officers may favour their own faction (a tribe or a party) instead of pursuing the general interest. Moreover they tend to overinvest in strengthening their power, thus engaging in power struggles with opposing factions, unlikely to benefit society. In this respect we present a new mathematical model aiming at describing a more efficient parliament where sortition is brought to bear. It will be shown that starting from a parliament working with two parties (or coalitions), where the costs of representative democracy are quite apparent through the detrimental effects of party discipline, one can beneficially move towards a parliament where independent legislators, randomly selected from the population of constituents, sit alongside elected members who belong to a party and are subjected to party discipline. The paper shows that increasing the number of independent legislators up to a point enhances the efficiency of the parliament and puts into check the factionalism likely to arise from party discipline. 9 Cfr. Najemy (1982) for 'scrutinio e tratta' and Wolfson (1899) for 'brevia'. 10 "Dappoich'è Fiorentini ebbono novelle della morte del duca, ebbono più consigli e ragionamenti e avvisi, come dovessono riformare la città di reggimento e signoria per modo comune, acciocché si levassono le sette tra' cittadini": Villani (1845), III, p.103. 11 "Capitulum ad evitandum quod aliquis qui non sit de consilio generali debeat stare ad sortes recipiendas, et ad evitandum contentiones super hoc": Statuta Communis Parmae (1855), II, p. 39. In fact, beyond factions, sortition was also intended to reduce corruption and violence: see Wolfson (1899), p. 12.
It is a widespread belief that success is mainly due to innate qualities, rather than to external... more It is a widespread belief that success is mainly due to innate qualities, rather than to external forces. This is particularly true in sport competitions, where individual talent is considered the only ingredient in order to reach success. In this study, we propose to explore the relative weight of talent and luck in individual sports through agent-based models. In particular, we chose fencing as case study, that is a combat sport involving a weapon. Fencing competitions are structured as direct elimination tournaments, where randomness is explicitly present in some rules. Our dataset covers the last decade of international events and consists of both single competition results and annual rankings for male and female fencers under 20 years old (Junior category). We show that our agent-based approach, calibrated on the dataset and parametrized by just one free variable a describing the importance of talent in competitions (a = 1 indicates the ideal scenario where only talent matters,...
arXiv: Geophysics, 2017
The analysis of the seismic vulnerability of urban centres has received a great attention in the ... more The analysis of the seismic vulnerability of urban centres has received a great attention in the last century. In order to estimate the seismic vulnerability of a densely populated urban area, it would in principle be necessary to develop in-depth analyses for predicting the dynamic behaviour of the individual buildings and their structural aggregation. Such analyses, however, are extremely cost-intensive, require great processing time and above all expertise judgement. It is therefore very useful to define simplified rules for estimating the seismic vulnerability of whole urban areas. In the last decades, the Self-Organized Criticality (SOC) scenario has gained increasing credibility as a mathematical framework for explaining a large number of naturally occurring extreme events, from avalanches to earthquakes dynamics, from bubbles and crises in financial markets to the extinction of species in the evolution or the behaviour of human brain activity. All these examples show the intr...
In this paper we discuss the problems of modern representative democracy and we look at the rando... more In this paper we discuss the problems of modern representative democracy and we look at the random selection of legislators as an extreme form of the proportional political representation, arguing that it is the way to make representative democracy as close to direct democracy as possible. In this respect we present a new mathematical model which attempts at describing a more efficient parliament where part of the members are selected by lot. It will be shown that starting from a parliament working with two parties (or coalitions), where the costs of representative democracy are quite apparent, one can beneficially move towards a parliament where independent legislators, randomly selected from the population of constituents, sit alongside with party members. The paper shows that increasing the number of independent legislators up to a point enhances the efficiency of the parliament.
arXiv: Geophysics, 2019
The analysis of the seismic vulnerability of urban centres has received a great attention in the ... more The analysis of the seismic vulnerability of urban centres has received a great attention in the last century, due to the progressive concentration of buildings in metropolitan areas. In order to estimate the seismic vulnerability of a densely populated urban area, it would in principle be necessary to develop in-depth analyses for predicting the dynamic behaviour of the individual buildings and their structural aggregation when subjected to the expected earthquake. Furthermore, in order to correctly estimate the soil structure interaction, reliable geological data for each site should be available. These detailed seismic analyses, however, are extremely cost-intensive, require great processing time and expertise judgement. The aim of the present study is to propose a new methodology able to combine information and tools coming from different scientific fields in order to reproduce the effects of a seismic input in urban areas, with known geological features, and to estimate the ent...
Scientific Reports, 2021
An amendment to this paper has been published and can be accessed via a link at the top of the pa... more An amendment to this paper has been published and can be accessed via a link at the top of the paper.
Physica A: Statistical Mechanics and its Applications, 2021
In this paper we present a new analytical model of a Parliament and investigate the beneficial ef... more In this paper we present a new analytical model of a Parliament and investigate the beneficial effects of the selection of legislators by lot in order to reduce some of the drawbacks of modern representative democracies. Resorting to sortition for the selection of public officers used to be in the past a popular way of taming factionalism in public affairs. Factionalism is assumed to be detrimental since public officers tend to favour their own faction instead of pursuing the general interest. In this respect our mathematical model shows in a rigorous way how it is possible to improve the efficiency of a Parliament by introducing the use of sortition to select part of its members. It will be shown that, starting from a Parliament working with two parties (or coalitions), where the costs of representative democracy are quite apparent through the detrimental effects of party discipline, one can beneficially move towards a Parliament where independent, randomly selected legislators sit alongside elected members. In particular, we show that increasing the number of independent legislators up to a critical point enhances the efficiency of the Parliament and puts into check the factionalism likely to arise from party discipline.
Journal of Statistical Mechanics: Theory and Experiment, 2019
Growing network models have been shown to display emergent quantum statistics when nodes are asso... more Growing network models have been shown to display emergent quantum statistics when nodes are associated to a fitness value describing the intrinsic ability of a node to acquire new links. Recently it has been shown that quantum statistics emerge also in a growing simplicial complex model called Network Geometry with Flavor which allows for the description of many-body interactions between the nodes. This model depends on an external parameter called flavor that is responsible for the underlying topology of the simplicial complex. When the flavor takes the value s = −1 the d-dimensional simplicial complex is a manifold in which every (d − 1)-dimensional face can only have an incidence number n α ∈ {0, 1}. In this case the faces of the simplicial complex are naturally described by the Bose-Einstein, Boltzmann and Fermi-Dirac distribution depending on their dimension. In this paper we extend the study of Network Geometry with Flavor to fractional values of the flavor s = −1/m in which every (d − 1)-dimensional face can only have incidence number n α ∈ {0, 1, 2,. .. , m}. We show that in this case the statistical properties of the faces of the simplicial complex are described by the Bose-Einstein or the Fermi-Dirac distribution only. Finally we comment on the spectral properties of the networks constituting the underlying structure of the considered simplicial complexes.
Heavy Ion Physics and Its Applications, 1996
ABSTRACT
Nuclear Physics, Mar 1, 1993
We report here on the measurements of one-particle transfer cross sections and quasi-elastic scat... more We report here on the measurements of one-particle transfer cross sections and quasi-elastic scattering of 32S+64Ni at energies around and well below the Coulomb barrier. The experiment has been performed with the Legnaro Recoil Mass Spectrometer. We have measured the excitation function at 0era = 170 ° from Ejab = 68.3 to 92.4 MeV and the angular distribution at Elab = 81.3 MeV from 0cm = 120 ° to 170 °. The results have been analysed in the framework of the complex WKB theory and the semiclassical approach based on Coulomb trajectories.
PLOS ONE
It is a widespread belief that success is mainly due to innate qualities rather than external for... more It is a widespread belief that success is mainly due to innate qualities rather than external forces. This is particularly true in sports competitions, where individual talent is usually considered the main, if not the only, ingredient to reach success. In this study, we explore the limits of this belief by quantifying the relative weight of talent and chance in fencing, a combat sport involving a weapon, with the help of both real data and agent-based simulations. Fencing competitions are structured as direct elimination tournaments, where randomness is explicitly present in some rules. We focused on épée, which is one of three disciplines. We collected data on international competition results and annual rankings, in the range 2008–2020, for male and female fencers under 20 years old (Junior category). Then, we built the model calibrated on our dataset and parametrized by just one free variable a, describing the importance of talent—and, consequently, of chance—in competitions (a ...
Frontiers in Physics
The rise of disinformation in the last years has shed light on the presence of bad actors that pr... more The rise of disinformation in the last years has shed light on the presence of bad actors that produce and spread misleading content every day. Therefore, looking at the characteristics of these actors has become crucial for gaining better knowledge of the phenomenon of disinformation to fight it. This study seeks to understand how these actors, meant here as unreliable news websites, differ from reliable ones. With this aim, we investigated some well-known fake and reliable news sources and their relationships, using a network growth model based on the overlap of their audience. Then, we peered into the news sites’ sub-networks and their structure, finding that unreliable news sources’ sub-networks are overall disassortative and have a low–medium clustering coefficient, indicative of a higher fragmentation. The k-core decomposition allowed us to find the coreness value for each node in the network, identifying the most connectedness site communities and revealing the structural org...
It is a widespread belief that success is mainly due to innate qualities, rather than to external... more It is a widespread belief that success is mainly due to innate qualities, rather than to external forces.This is particularly true in sport competitions, where individual talent is usually considered the main, if not the only, ingredient in order to reach success. In this study, with the help of both real data and agent-based simulations, we explore the limits of this belief by quantifying the relative weight of talent and chance in fencing, a combat sport involving a weapon. Fencing competitions are structured as direct elimination tournaments, where randomness is explicitly present in some rules. Our dataset covers the last decade of international events and consists of both single competition results and annual rankings for male and female fencers under 20 years old (Junior category). Our model is calibrated on the dataset and parametrized by just one free variable 'a' describing the importance of talent - and, consequently, of chance - in competitions (a = 1 indicates th...
Frontiers in Physics, 2021
In early January 2020, after China reported the first cases of the new coronavirus (SARS-CoV-2) i... more In early January 2020, after China reported the first cases of the new coronavirus (SARS-CoV-2) in the city of Wuhan, unreliable and not fully accurate information has started spreading faster than the virus itself. Alongside this pandemic, people have experienced a parallel infodemic, i.e., an overabundance of information, some of which is misleading or even harmful, which has widely spread around the globe. Although social media are increasingly being used as the information source, web search engines, such as Google or Yahoo!, still represent a powerful and trustworthy resource for finding information on the Web. This is due to their capability to capture the largest amount of information, helping users quickly identify the most relevant, useful, although not always the most reliable, results for their search queries. This study aims to detect potential misleading and fake contents by capturing and analysing textual information, which flow through search engines. By using a real-...
Research in Transportation Economics, 2019
Limiting private cars' use while promoting sustainable modes of transport is one of the main chal... more Limiting private cars' use while promoting sustainable modes of transport is one of the main challenges of urban transport planning. In this context, characterized by scarce resources and increasing demand for mobility, Demand Responsive Shared Transport (DRST) services can bridge the gap between shared low-quality public transport and unsustainable individual private transport. Taking advantage of Information and Communication Technologies (ICT), they can supply transport solutions ranging from flexible transit to ride sharing services, providing real-time "on demand" mobility through fleets of vehicles shared by different passengers. The optimal design of a DRST service requires a trade-off among efficiency (from the operators' point of view), service quality (from the users' point of view) and sustainability (from the community's point of view). In this paper, an agentbased model (ABM) fed with GIS data is used to explore different system configurations of a specific type of DRST service, i.e. flexible transit, and to estimate the transport demand and supply variables that make the service feasible and convenient. The model reproduces a mixed fixed/flexible route transit service with different fleet size and vehicle capacity in the city of Ragusa (Italy) with the aim to: (i) make a first test of the ABM model with GIS-based demand and road network models; (ii) explore different vehicle dispatching strategies; (iii) find appropriate indicators to monitor the service quality and efficiency. Simulation results show the impact of fleet composition and route choice strategy on the system performance. In particular, they show an optimal range of operating vehicles that minimizes a total unit cost indicator, accounting both for passenger travel time and vehicle operation cost. By reproducing the microinteraction between demand and supply agents (i.e. passengers and vehicles), it is possible to monitor the macroscopic behaviour of the system, and derive useful suggestions for the correct planning, management and optimization of DRST services.
AIP Conference Proceedings, 2007
We analyze the role of the correlated fluctuations, with a correlation time T^, in the dynamics o... more We analyze the role of the correlated fluctuations, with a correlation time T^, in the dynamics of an overdamped Josephson junction in the presence of a periodic driving signal.
AIP Conference Proceedings, 2007
ABSTRACT
In this paper we present experimental results concerning Acoustic Emission (AE) recorded during c... more In this paper we present experimental results concerning Acoustic Emission (AE) recorded during cyclic compression tests on two different kinds of brittle building materials, namely concrete and basalt. The AE inter-event times were investigated through a non-extensive statistical mechanics analysis which shows that their decumulative probability distributions follow q-exponential laws. The entropic index q and the relaxation parameter q 1=Tq, obtained by fitting the experimental data, exhibit systematic changes during the various stages of the failure process, namely (q; Tq) linearly align. The Tq = 0 point corresponds to the macroscopic breakdown of the material. The slope, including its sign, of the linear alignment appears to depend on the chemical and mechanical properties of the sample. These results provide an insight on the warning signs of the incipient failure of building materials and could therefore be used in monitoring the health of existing structures such as building...
Individual sports competitions provide a natural setting for examining the relative importance of... more Individual sports competitions provide a natural setting for examining the relative importance of talent and luck in achieving success. The belief that success is primarily due to individual abilities and hard work rather than external factors is especially strong in this context. Thus, individual talent is regarded as the most important – if not the only – component in ensuring a successful career for players. In this study, we test this belief through detailed data analysis and comparison with an agent-based model, using tennis as a case study due to its popularity and competition structure in direct-elimination tournaments. Our dataset covers the last decade (2010-2019) of main international events in the ATP circuit and consists of tourney results and annual rankings for professional male players. We show that our agent-based model, calibrated on the dataset, can reproduce the main stylized facts observed in real data, including the results of single tournaments and the developm...
arXiv (Cornell University), Dec 12, 2017
In this paper we discuss the problems of modern representative democracy and we look at the selec... more In this paper we discuss the problems of modern representative democracy and we look at the selection of legislators by lot as a way to tame some of the drawbacks of that system. It is recalled at the beginning that resorting to sortition for the selection of public officers used to be a popular way of taming factionalism in public affairs. Factionalism is assumed to be detrimental to public affairs as public officers may favour their own faction (a tribe or a party) instead of pursuing the general interest. Moreover they tend to overinvest in strengthening their power, thus engaging in power struggles with opposing factions, unlikely to benefit society. In this respect we present a new mathematical model aiming at describing a more efficient parliament where sortition is brought to bear. It will be shown that starting from a parliament working with two parties (or coalitions), where the costs of representative democracy are quite apparent through the detrimental effects of party discipline, one can beneficially move towards a parliament where independent legislators, randomly selected from the population of constituents, sit alongside elected members who belong to a party and are subjected to party discipline. The paper shows that increasing the number of independent legislators up to a point enhances the efficiency of the parliament and puts into check the factionalism likely to arise from party discipline. 9 Cfr. Najemy (1982) for 'scrutinio e tratta' and Wolfson (1899) for 'brevia'. 10 "Dappoich'è Fiorentini ebbono novelle della morte del duca, ebbono più consigli e ragionamenti e avvisi, come dovessono riformare la città di reggimento e signoria per modo comune, acciocché si levassono le sette tra' cittadini": Villani (1845), III, p.103. 11 "Capitulum ad evitandum quod aliquis qui non sit de consilio generali debeat stare ad sortes recipiendas, et ad evitandum contentiones super hoc": Statuta Communis Parmae (1855), II, p. 39. In fact, beyond factions, sortition was also intended to reduce corruption and violence: see Wolfson (1899), p. 12.
It is a widespread belief that success is mainly due to innate qualities, rather than to external... more It is a widespread belief that success is mainly due to innate qualities, rather than to external forces. This is particularly true in sport competitions, where individual talent is considered the only ingredient in order to reach success. In this study, we propose to explore the relative weight of talent and luck in individual sports through agent-based models. In particular, we chose fencing as case study, that is a combat sport involving a weapon. Fencing competitions are structured as direct elimination tournaments, where randomness is explicitly present in some rules. Our dataset covers the last decade of international events and consists of both single competition results and annual rankings for male and female fencers under 20 years old (Junior category). We show that our agent-based approach, calibrated on the dataset and parametrized by just one free variable a describing the importance of talent in competitions (a = 1 indicates the ideal scenario where only talent matters,...
arXiv: Geophysics, 2017
The analysis of the seismic vulnerability of urban centres has received a great attention in the ... more The analysis of the seismic vulnerability of urban centres has received a great attention in the last century. In order to estimate the seismic vulnerability of a densely populated urban area, it would in principle be necessary to develop in-depth analyses for predicting the dynamic behaviour of the individual buildings and their structural aggregation. Such analyses, however, are extremely cost-intensive, require great processing time and above all expertise judgement. It is therefore very useful to define simplified rules for estimating the seismic vulnerability of whole urban areas. In the last decades, the Self-Organized Criticality (SOC) scenario has gained increasing credibility as a mathematical framework for explaining a large number of naturally occurring extreme events, from avalanches to earthquakes dynamics, from bubbles and crises in financial markets to the extinction of species in the evolution or the behaviour of human brain activity. All these examples show the intr...
In this paper we discuss the problems of modern representative democracy and we look at the rando... more In this paper we discuss the problems of modern representative democracy and we look at the random selection of legislators as an extreme form of the proportional political representation, arguing that it is the way to make representative democracy as close to direct democracy as possible. In this respect we present a new mathematical model which attempts at describing a more efficient parliament where part of the members are selected by lot. It will be shown that starting from a parliament working with two parties (or coalitions), where the costs of representative democracy are quite apparent, one can beneficially move towards a parliament where independent legislators, randomly selected from the population of constituents, sit alongside with party members. The paper shows that increasing the number of independent legislators up to a point enhances the efficiency of the parliament.
arXiv: Geophysics, 2019
The analysis of the seismic vulnerability of urban centres has received a great attention in the ... more The analysis of the seismic vulnerability of urban centres has received a great attention in the last century, due to the progressive concentration of buildings in metropolitan areas. In order to estimate the seismic vulnerability of a densely populated urban area, it would in principle be necessary to develop in-depth analyses for predicting the dynamic behaviour of the individual buildings and their structural aggregation when subjected to the expected earthquake. Furthermore, in order to correctly estimate the soil structure interaction, reliable geological data for each site should be available. These detailed seismic analyses, however, are extremely cost-intensive, require great processing time and expertise judgement. The aim of the present study is to propose a new methodology able to combine information and tools coming from different scientific fields in order to reproduce the effects of a seismic input in urban areas, with known geological features, and to estimate the ent...
Scientific Reports, 2021
An amendment to this paper has been published and can be accessed via a link at the top of the pa... more An amendment to this paper has been published and can be accessed via a link at the top of the paper.
Physica A: Statistical Mechanics and its Applications, 2021
In this paper we present a new analytical model of a Parliament and investigate the beneficial ef... more In this paper we present a new analytical model of a Parliament and investigate the beneficial effects of the selection of legislators by lot in order to reduce some of the drawbacks of modern representative democracies. Resorting to sortition for the selection of public officers used to be in the past a popular way of taming factionalism in public affairs. Factionalism is assumed to be detrimental since public officers tend to favour their own faction instead of pursuing the general interest. In this respect our mathematical model shows in a rigorous way how it is possible to improve the efficiency of a Parliament by introducing the use of sortition to select part of its members. It will be shown that, starting from a Parliament working with two parties (or coalitions), where the costs of representative democracy are quite apparent through the detrimental effects of party discipline, one can beneficially move towards a Parliament where independent, randomly selected legislators sit alongside elected members. In particular, we show that increasing the number of independent legislators up to a critical point enhances the efficiency of the Parliament and puts into check the factionalism likely to arise from party discipline.
Journal of Statistical Mechanics: Theory and Experiment, 2019
Growing network models have been shown to display emergent quantum statistics when nodes are asso... more Growing network models have been shown to display emergent quantum statistics when nodes are associated to a fitness value describing the intrinsic ability of a node to acquire new links. Recently it has been shown that quantum statistics emerge also in a growing simplicial complex model called Network Geometry with Flavor which allows for the description of many-body interactions between the nodes. This model depends on an external parameter called flavor that is responsible for the underlying topology of the simplicial complex. When the flavor takes the value s = −1 the d-dimensional simplicial complex is a manifold in which every (d − 1)-dimensional face can only have an incidence number n α ∈ {0, 1}. In this case the faces of the simplicial complex are naturally described by the Bose-Einstein, Boltzmann and Fermi-Dirac distribution depending on their dimension. In this paper we extend the study of Network Geometry with Flavor to fractional values of the flavor s = −1/m in which every (d − 1)-dimensional face can only have incidence number n α ∈ {0, 1, 2,. .. , m}. We show that in this case the statistical properties of the faces of the simplicial complex are described by the Bose-Einstein or the Fermi-Dirac distribution only. Finally we comment on the spectral properties of the networks constituting the underlying structure of the considered simplicial complexes.
Heavy Ion Physics and Its Applications, 1996
ABSTRACT