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Global sustainability relies on our capacity of understanding and guiding urban systems and their metabolism adequately. It has been proposed that bigger and denser cities are more resource-efficient than smaller ones because they tend to demand less infrastructure, consume less fuel for transportation and less energy for cooling/heating in per capita terms. This hypothesis is also called Brand’s Law. However, as cities get bigger, denser and more resource-efficient, they also get richer, and richer inhabitants consume more, potentially increasing resource demand and associated environmental impacts. In this paper, we propose a method based on scaling theory to assess Brand’s Law taking into account greenhouse gas (GHG) emissions from both direct (energy and fuels locally consumed) and indirect (embedded in goods and services) sources, measured as carbon footprint (CF). We aim at understanding whether Brand’s Law can be confirmed once we adopt a consumption-based approach to urban emissions. By analyzing the balance between direct and indirect emissions in a theoretical urban system, we develop a scaling theory relating carbon footprint and city size. Facing the lack of empirical data on consumption-based emissions for cities, we developed a model to derive emission estimations using well-established urban metrics (city size, density, infrastructure, wealth). Our results show that, once consumption-based CF is considered, Brand’s Law falls apart, as bigger cities have greater purchase power, leading to greater consumption of goods and higher associated GHG. Findings also suggest that a shift in consumption patterns is of utmost importance, given that, according to the model, each new monetary unit added to the gross domestic product (GDP) or to other income variables results in a more than proportional increase in GHG emissions. This work contributes to a broader assessment of the causes of emissions and the paradigm shift regarding the assumption of efficiency in the relationship of city size and emissions, adding consumption behavior as a critical variable, beyond Brand’s Law.
Joao Meirelles; Fabiano Ribeiro; Gabriel Cury; Claudia Binder; Vinicius Netto. More from Less? Environmental Rebound Effects of City Size. Sustainability 2021, 13, 4028 .
AMA StyleJoao Meirelles, Fabiano Ribeiro, Gabriel Cury, Claudia Binder, Vinicius Netto. More from Less? Environmental Rebound Effects of City Size. Sustainability. 2021; 13 (7):4028.
Chicago/Turabian StyleJoao Meirelles; Fabiano Ribeiro; Gabriel Cury; Claudia Binder; Vinicius Netto. 2021. "More from Less? Environmental Rebound Effects of City Size." Sustainability 13, no. 7: 4028.
Revista de Morfologia Urbana. Uma publicação do PNUM Portuguese-Speaking Network of Urban Morphology
Fabiano Ribeiro. A física das cidades. Revista de Morfologia Urbana 2020, 8, e00159 -e00159.
AMA StyleFabiano Ribeiro. A física das cidades. Revista de Morfologia Urbana. 2020; 8 (1):e00159-e00159.
Chicago/Turabian StyleFabiano Ribeiro. 2020. "A física das cidades." Revista de Morfologia Urbana 8, no. 1: e00159-e00159.
Revista de Morfologia Urbana. Uma publicação do PNUM Portuguese-Speaking Network of Urban Morphology
Vinicius M. Netto; Fabiano Ribeiro. In Memoriam. Revista de Morfologia Urbana 2020, 8, e00175 -e00175.
AMA StyleVinicius M. Netto, Fabiano Ribeiro. In Memoriam. Revista de Morfologia Urbana. 2020; 8 (1):e00175-e00175.
Chicago/Turabian StyleVinicius M. Netto; Fabiano Ribeiro. 2020. "In Memoriam." Revista de Morfologia Urbana 8, no. 1: e00175-e00175.
Nos últimos anos, a nova Ciência das Cidades se estabeleceu como uma abordagem quantitativa fértil para o entendimento dos fenômenos urbanos. Um de seus pilares é a proposição de que os sistemas urbanos apresentam comportamentos universais de escala de variáveis socioeconômicas, de infraestrutura e de serviços básicos individuais. Este artigo discute até onde essa proposição é realmente universal, testando-a frente a uma ampla variedade de métricas urbanas de um país em desenvolvimento. Apresentamos uma exploração dos expoentes de escala(mento) de mais de 60 variáveis do sistema urbano brasileiro. A estimação dos expoentes é um desafio técnico, dado que a definição de "município" no Brasil segue critérios políticos e não considera as características da paisagem, a densidade e os serviços domiciliares básicos. Considerando que os municípios brasileiros podem não ser iguais ao que se entende por assentamento urbanizado, selecionamos os mais assemelhados a "cidades" através de um procedimento sistemático de corte da densidade e estimamos os expoentes desse subconjunto. Para validar nossos achados, comparamos nossos resultados para as mesmas variáveis com outros estudos baseados em métodos alternativos. Os resultados mostram que as variáveis socioeconômicas analisadas seguem uma relação de escala superlinear com a população das cidades, enquanto a maioria das variáveis de infraestrutura e de serviços básicos domiciliares seguem os esperados regimes sublinear e linear, respectivamente. No entanto, algumas delas fogem dos regimes esperados, botando em dúvida a hipótese universal do escalamento urbano / leis de escala. Nossa conclusão é de que esses desvios são produto de decisões e políticas impostas "de cima para baixo". Mesmo que nossa análise abranja um período de apenas 10 anos e, portanto, não seja suficiente para permitir conclusões definitivas, há indícios de que os expoentes de escala dessas variáveis estão evoluindo e que os desvios podem ser apenas comportamentos restritos no tempo que não impedem os sistemas urbanos de atingir o regime esperado em algum momento futuro.
João Vitor Meirelles; Camilo Rodrigues Neto; Fernando Fagundes Ferreira; Fabiano L Ribeiro; Claudia Rebeca Binder. Evolução das leis de escala urbanas. Revista de Morfologia Urbana 2020, 8, e00168 -e00168.
AMA StyleJoão Vitor Meirelles, Camilo Rodrigues Neto, Fernando Fagundes Ferreira, Fabiano L Ribeiro, Claudia Rebeca Binder. Evolução das leis de escala urbanas. Revista de Morfologia Urbana. 2020; 8 (1):e00168-e00168.
Chicago/Turabian StyleJoão Vitor Meirelles; Camilo Rodrigues Neto; Fernando Fagundes Ferreira; Fabiano L Ribeiro; Claudia Rebeca Binder. 2020. "Evolução das leis de escala urbanas." Revista de Morfologia Urbana 8, no. 1: e00168-e00168.
Does the scaling relationship between population sizes of cities with urban metrics like economic output and infrastructure (transversal scaling) mirror the evolution of individual cities in time (longitudinal scaling)? The answer to this question has important policy implications, but the lack of suitable data has so far hindered rigorous empirical tests. In this paper, we advance the debate by looking at the evolution of two urban variables, GDP and water network length, for over 5500 cities in Brazil. We find that longitudinal scaling exponents are city-specific. However, they are distributed around an average value that approaches the transversal scaling exponent provided that the data is decomposed to eliminate external factors, and only for cities with a sufficiently high growth rate. We also introduce a mathematical framework that connects the microscopic level to global behaviour, finding good agreement between theoretical predictions and empirical evidence in all analyzed cases. Our results add complexity to the idea that the longitudinal dynamics is a micro-scaling version of the transversal dynamics of the entire urban system. The longitudinal analysis can reveal differences in scaling behavior related to population size and nature of urban variables. Our approach also makes room for the role of external factors such as public policies and development, and opens up new possibilities in the research of the effects of scaling and contextual factors.
Fabiano L. Ribeiro; Joao Meirelles; Vinicius M. Netto; Camilo Rodrigues Neto; Andrea Baronchelli. On the relation between transversal and longitudinal scaling in cities. PLOS ONE 2020, 15, e0233003 .
AMA StyleFabiano L. Ribeiro, Joao Meirelles, Vinicius M. Netto, Camilo Rodrigues Neto, Andrea Baronchelli. On the relation between transversal and longitudinal scaling in cities. PLOS ONE. 2020; 15 (5):e0233003.
Chicago/Turabian StyleFabiano L. Ribeiro; Joao Meirelles; Vinicius M. Netto; Camilo Rodrigues Neto; Andrea Baronchelli. 2020. "On the relation between transversal and longitudinal scaling in cities." PLOS ONE 15, no. 5: e0233003.
Vinicius M. Netto; João Meirelles; Fabiano L Ribeiro; Claudia R. Binder; Romano Wyss; Emanuele Massaro. Cities and Entropy: Assessing Urban Sustainability as a Problem of Coordination. Sustainability Assessment of Urban Systems 2020, 438 -459.
AMA StyleVinicius M. Netto, João Meirelles, Fabiano L Ribeiro, Claudia R. Binder, Romano Wyss, Emanuele Massaro. Cities and Entropy: Assessing Urban Sustainability as a Problem of Coordination. Sustainability Assessment of Urban Systems. 2020; ():438-459.
Chicago/Turabian StyleVinicius M. Netto; João Meirelles; Fabiano L Ribeiro; Claudia R. Binder; Romano Wyss; Emanuele Massaro. 2020. "Cities and Entropy: Assessing Urban Sustainability as a Problem of Coordination." Sustainability Assessment of Urban Systems , no. : 438-459.
In this study, we show the convergence and new properties of persistence length, λN, for the self-avoiding random Walk model (SAW) using Monte Carlo data. We generate high precision estimates of several conformational quantities with pivot algorithm for the square, hexagonal, triangular, cubic and diamond lattices with path lengths of 103 steps. For each lattice, we accurately estimate the asymptotic limit λ∞, which corroborates the convergence of λN to a constant value, and allows us to check the universality on the λN/λ∞ curves. Based on the λ∞ estimates we make an ansatz for λ∞ dependency with lattice cell and spatial dimension, we also find a new geometric interpretation for the persistence length.
C R F Granzotti; Fabiano L Ribeiro; Alexandre Souto Martinez; Marco Antonio Alves da Silva. Persistence length convergence and universality for the self-avoiding random walk. Journal of Physics A: Mathematical and Theoretical 2019, 52, 075002 .
AMA StyleC R F Granzotti, Fabiano L Ribeiro, Alexandre Souto Martinez, Marco Antonio Alves da Silva. Persistence length convergence and universality for the self-avoiding random walk. Journal of Physics A: Mathematical and Theoretical. 2019; 52 (7):075002.
Chicago/Turabian StyleC R F Granzotti; Fabiano L Ribeiro; Alexandre Souto Martinez; Marco Antonio Alves da Silva. 2019. "Persistence length convergence and universality for the self-avoiding random walk." Journal of Physics A: Mathematical and Theoretical 52, no. 7: 075002.
In the last decades, power grids and other energy transmission networks have received attention from the network literature. In this work, we studied one of the most important static features of power grids, their topology, with focus on the Brazilian Power Grid (BPG). We obtained the spatial structure of the BPG from the ONS (Electric System National Operator), consisting of its high-voltage transmission lines, electric stations and substations. Some traits had to be ignored, such as the local low-voltage substations and as well the dynamic features of the network. We analyzed the complex network of the BPG and its statistics, such as the mean degree, the degree distribution, the network size and the clustering coefficient to characterize the complex network. We also detected critical locations in the network and, therefore, points that are more susceptible to cascading failures and even to blackouts. Our results show that the BPG is functional against random failures, regarding random removal of links and connections, in terms of the size of the largest cluster. We observe that when a fraction ρ of the links are randomly removed, the network may break down into smaller, disconnected parts. However, the largest component of the power grid remains connected. We believe that even a static study of the network topology can help to identify the critical situations and also prevent failures and possible blackouts.
Gabriela Da Cruz Martins; Fabiano Ribeiro; Leonardo Santos Oliveira; Fabricio Luchesi Forgerini. Complex network analysis of the Brazilian power grid. Scientia Plena 2018, 14, 1 .
AMA StyleGabriela Da Cruz Martins, Fabiano Ribeiro, Leonardo Santos Oliveira, Fabricio Luchesi Forgerini. Complex network analysis of the Brazilian power grid. Scientia Plena. 2018; 14 (10):1.
Chicago/Turabian StyleGabriela Da Cruz Martins; Fabiano Ribeiro; Leonardo Santos Oliveira; Fabricio Luchesi Forgerini. 2018. "Complex network analysis of the Brazilian power grid." Scientia Plena 14, no. 10: 1.
From physics to the social sciences, information is now seen as a fundamental component of reality. However, a form of information seems still underestimated, perhaps precisely because it is so pervasive that we take it for granted: the information encoded in the very environment we live in. We still do not fully understand how information takes the form of cities, and how our minds deal with it in order to learn about the world, make daily decisions, and take part in the complex system of interactions we create as we live together. This paper addresses three related problems that need to be solved if we are to understand the role of environmental information: (1) the physical problem: how can we preserve information in the built environment? (2) The semantic problem: how do we make environmental information meaningful? and (3) the pragmatic problem: how do we use environmental information in our daily lives? Attempting to devise a solution to these problems, we introduce a three-layered model of information in cities, namely environmental information in physical space, environmental information in semantic space, and the information enacted by interacting agents. We propose forms of estimating entropy in these different layers, and apply these measures to emblematic urban cases and simulated scenarios. Our results suggest that ordered spatial structures and diverse land use patterns encode information, and that aspects of physical and semantic information affect coordination in interaction systems.
Vinicius M. Netto; Edgardo Brigatti; João Meirelles; Fabiano L Ribeiro; Bruno Pace; Caio Cacholas; Patricia Sanches. Cities, from Information to Interaction. Entropy 2018, 20, 834 .
AMA StyleVinicius M. Netto, Edgardo Brigatti, João Meirelles, Fabiano L Ribeiro, Bruno Pace, Caio Cacholas, Patricia Sanches. Cities, from Information to Interaction. Entropy. 2018; 20 (11):834.
Chicago/Turabian StyleVinicius M. Netto; Edgardo Brigatti; João Meirelles; Fabiano L Ribeiro; Bruno Pace; Caio Cacholas; Patricia Sanches. 2018. "Cities, from Information to Interaction." Entropy 20, no. 11: 834.
From physics to the social sciences, information is now seen as a fundamental component of reality. However, a form of information seems still underestimated, perhaps precisely because it is so pervasive that we take it for granted: the information encoded in the very environment we live in. We still do not fully understand how information takes the form of cities, and how our minds deal with it in order to learn about the world, make daily decisions, and take part in the complex system of interactions we create as we live together. This paper addresses three related problems that need to be solved if we are to understand the role of environmental information: (1) the physical problem: how can we preserve information in the built environment? (2) The semantic problem: how do we make environmental information meaningful? And (3) the pragmatic problem: how do we enact environmental information in our daily lives? Attempting to devise a solution to these problems, we introduce a three-layered model of information in cities, namely environmental information in physical space, environmental information in semantic space, and the information enacted by interacting agents. We propose forms of calculating entropy in these different layers, and apply these measures to archetypal urban cases and simulated scenarios. Our results suggest that ordered spatial structures and diverse land use patterns encode information, and that aspects of physical and semantic information affect coordination in interaction systems.
Vinicius M. Netto; Edgardo Brigatti; João Meirelles; Fabiano L. Ribeiro; Bruno Pace; Caio Cacholas; Patricia Sanches. Cities, from Information to Interaction. 2018, 1 .
AMA StyleVinicius M. Netto, Edgardo Brigatti, João Meirelles, Fabiano L. Ribeiro, Bruno Pace, Caio Cacholas, Patricia Sanches. Cities, from Information to Interaction. . 2018; ():1.
Chicago/Turabian StyleVinicius M. Netto; Edgardo Brigatti; João Meirelles; Fabiano L. Ribeiro; Bruno Pace; Caio Cacholas; Patricia Sanches. 2018. "Cities, from Information to Interaction." , no. : 1.
During the last years, the new science of cities has been established as a fertile quantitative approach to systematically understand the urban phenomena. One of its main pillars is the proposition that urban systems display universal scaling behavior regarding socioeconomic, infrastructural and individual basic services variables. This paper discusses the extension of the universality proposition by testing it against a broad range of urban metrics in a developing country urban system. We present an exploration of the scaling exponents for over 60 variables for the Brazilian urban system. Estimating those exponents is challenging from the technical point of view because the Brazilian municipalities’ definition follows local political criteria and does not regard characteristics of the landscape, density, and basic utilities. As Brazilian municipalities can deviate significantly from urban settlements, urban-like municipalities were selected based on a systematic density cut-off procedure and the scaling exponents were estimated for this new subset of municipalities. To validate our findings we compared the results for overlaying variables with other studies based on alternative methods. It was found that the analyzed socioeconomic variables follow a superlinear scaling relationship with the population size, and most of the infrastructure and individual basic services variables follow expected sublinear and linear scaling, respectively. However, some infrastructural and individual basic services variables deviated from their expected regimes, challenging the universality hypothesis of urban scaling. We propose that these deviations are a product of top-down decisions/policies. Our analysis spreads over a time-range of 10 years, what is not enough to draw conclusive observations, nevertheless we found hints that the scaling exponent of these variables are evolving towards the expected scaling regime, indicating that the deviations might be temporally constrained and that the urban systems might eventually reach the expected scaling regime.
Joao Meirelles; Camilo Rodrigues Neto; Fernando Fagundes Ferreira; Fabiano L Ribeiro; Claudia Rebeca Binder. Evolution of urban scaling: Evidence from Brazil. PLOS ONE 2018, 13, e0204574 .
AMA StyleJoao Meirelles, Camilo Rodrigues Neto, Fernando Fagundes Ferreira, Fabiano L Ribeiro, Claudia Rebeca Binder. Evolution of urban scaling: Evidence from Brazil. PLOS ONE. 2018; 13 (10):e0204574.
Chicago/Turabian StyleJoao Meirelles; Camilo Rodrigues Neto; Fernando Fagundes Ferreira; Fabiano L Ribeiro; Claudia Rebeca Binder. 2018. "Evolution of urban scaling: Evidence from Brazil." PLOS ONE 13, no. 10: e0204574.
From physics to the social sciences, information is now seen as a fundamental component of reality. However, a form of information seems still underestimated, perhaps precisely because it is so pervasive that we take it for granted: the information encoded in the very environment we live in. We still do not fully understand how information takes the form of cities, and how our minds deal with it in order to learn about the world, make daily decisions, and take part in the complex system of interactions we create as we live together. This paper addresses three related problems that need to be solved if we are to understand the role of environmental information: (1) the physical problem: how can we preserve information in the built environment? (2) The semantic problem: how do we make environmental information meaningful? and (3) the pragmatic problem: how do we use environmental information in our daily lives? Attempting to devise a solution to these problems, we introduce a three-layered model of information in cities, namely environmental information in physical space, environmental information in semantic space, and the information enacted by interacting agents. We propose forms of estimating entropy in these different layers, and apply these measures to emblematic urban cases and simulated scenarios. Our results suggest that ordered spatial structures and diverse land use patterns encode information, and that aspects of physical and semantic information affect coordination in interaction systems.
Vinicius M. Netto; Edgardo Brigatti; João Meirelles; Fabiano L. Ribeiro; Bruno Pace; Caio Cacholas; Patricia Mara Sanches. Cities, from information to interaction. 2018, 1 .
AMA StyleVinicius M. Netto, Edgardo Brigatti, João Meirelles, Fabiano L. Ribeiro, Bruno Pace, Caio Cacholas, Patricia Mara Sanches. Cities, from information to interaction. . 2018; ():1.
Chicago/Turabian StyleVinicius M. Netto; Edgardo Brigatti; João Meirelles; Fabiano L. Ribeiro; Bruno Pace; Caio Cacholas; Patricia Mara Sanches. 2018. "Cities, from information to interaction." , no. : 1.
Resumo Como ações pessoais, aparentemente caóticas, podem gerar os imensos sistemas de interações em que vivemos? Neste artigo, buscamos responder a esta pergunta sugerindo que há um papel para as cidades, na forma de coordenar nossas ações. Investigamos esse processo explorando um conceito particular: a “entropia” ou como sistemas lidam com a incerteza e imprevisibilidade na transição de ações individuais para sistemas de ação. Examinando as condições de (i) as ações como dependentes da informação em seu ambiente e de (ii) a cidade como ambiente de informação, propomos que (iii) a cidade produz diferenças na probabilidade de que certas interações venham a ser realizadas. Investigamos este processo através de simulações de diferentes cenários, de modo a identificar o espaço como uma condição necessária, mas não suficiente, para reduzir entropia social. Finalmente, sugerimos que os estados e flutuações da entropia são uma parte vital da reprodução social, e revelam profundas conexões entre sistemas sociais, informacionais e espaciais.
Vinicius M. Netto; João Meirelles; Fabiano L Ribeiro. Cidade e interação: o papel do espaço urbano na organização social. urbe. Revista Brasileira de Gestão Urbana 2018, 10, 249 -267.
AMA StyleVinicius M. Netto, João Meirelles, Fabiano L Ribeiro. Cidade e interação: o papel do espaço urbano na organização social. urbe. Revista Brasileira de Gestão Urbana. 2018; 10 (2):249-267.
Chicago/Turabian StyleVinicius M. Netto; João Meirelles; Fabiano L Ribeiro. 2018. "Cidade e interação: o papel do espaço urbano na organização social." urbe. Revista Brasileira de Gestão Urbana 10, no. 2: 249-267.
How can individual acts amount to coherent systems of interaction? In this paper, we attempt to answer this key question by suggesting that there is a place for cities in the way we coordinate seemingly chaotic decisions. We look into the elementary processes of social interaction exploring a particular concept, “social entropy,” or how social systems deal with uncertainty and unpredictability in the transition from individual actions to systems of interaction. Examining possibilities that (i) actions rely on informational differences latent in their environments and that (ii) the city itself is an information environment to actions, we propose that (iii) space becomes a form of creating differences in the probabilities of interaction. We investigate this process through simulations of distinct material scenarios, to find that space is a necessary but not sufficient condition for the reduction of entropy. Finally, we suggest that states and fluctuations of entropy are a vital part of social reproduction and reveal a deep connection between social, informational, and spatial systems.
Vinicius M. Netto; Joao Meirelles; Fabiano L. Ribeiro. Social Interaction and the City: The Effect of Space on the Reduction of Entropy. Complexity 2017, 2017, 1 -16.
AMA StyleVinicius M. Netto, Joao Meirelles, Fabiano L. Ribeiro. Social Interaction and the City: The Effect of Space on the Reduction of Entropy. Complexity. 2017; 2017 ():1-16.
Chicago/Turabian StyleVinicius M. Netto; Joao Meirelles; Fabiano L. Ribeiro. 2017. "Social Interaction and the City: The Effect of Space on the Reduction of Entropy." Complexity 2017, no. : 1-16.
For years, the comprehension of the tumor growth process has been intriguing scientists. New research has been constantly required to better understand the complexity of this phenomenon. In this paper, we propose a mathematical model that describes the properties, already known empirically, of avascular tumor growth. We present, from an individual-level (microscopic) framework, an explanation of some phenomenological (macroscopic) aspects of tumors, such as their spatial form and the way they develop. Our approach is based on competitive interaction between the cells. This simple rule makes the model able to reproduce evidence observed in real tumors, such as exponential growth in their early stage followed by power-law growth. The model also reproduces (i) the fractal-space distribution of tumor cells and (ii) the universal growth behavior observed in both animals and tumors. Our analyses suggest that the universal similarity between tumor and animal growth comes from the fact that both can be described by the same dynamic equation—the Bertalanffy-Richards model—even if they do not necessarily share the same biological properties.
Fabiano L. Ribeiro; Renato Vieira Dos Santos; Angélica Sousa da Mata. Fractal dimension and universality in avascular tumor growth. Physical Review E 2017, 95, 042406 .
AMA StyleFabiano L. Ribeiro, Renato Vieira Dos Santos, Angélica Sousa da Mata. Fractal dimension and universality in avascular tumor growth. Physical Review E. 2017; 95 (4):042406.
Chicago/Turabian StyleFabiano L. Ribeiro; Renato Vieira Dos Santos; Angélica Sousa da Mata. 2017. "Fractal dimension and universality in avascular tumor growth." Physical Review E 95, no. 4: 042406.
Socio-economic related properties of a city grow faster than a linear relationship with the population, in a log–log plot, the so-called superlinear scaling . Conversely, the larger a city, the more efficient it is in the use of its infrastructure, leading to a sublinear scaling on these variables. In this work, we addressed a simple explanation for those scaling laws in cities based on the interaction range between the citizens and on the fractal properties of the cities. To this purpose, we introduced a measure of social potential which captured the influence of social interaction on the economic performance and the benefits of amenities in the case of infrastructure offered by the city. We assumed that the population density depends on the fractal dimension and on the distance-dependent interactions between individuals. The model suggests that when the city interacts as a whole, and not just as a set of isolated parts, there is improvement of the socio-economic indicators. Moreover, the bigger the interaction range between citizens and amenities, the bigger the improvement of the socio-economic indicators and the lower the infrastructure costs of the city. We addressed how public policies could take advantage of these properties to improve cities development, minimizing negative effects. Furthermore, the model predicts that the sum of the scaling exponents of social-economic and infrastructure variables are 2, as observed in the literature. Simulations with an agent-based model are confronted with the theoretical approach and they are compatible with the empirical evidences.
Fabiano L. Ribeiro; Joao Meirelles; Fernando F. Ferreira; Camilo Rodrigues Neto. A model of urban scaling laws based on distance dependent interactions. Royal Society Open Science 2017, 4, 160926 .
AMA StyleFabiano L. Ribeiro, Joao Meirelles, Fernando F. Ferreira, Camilo Rodrigues Neto. A model of urban scaling laws based on distance dependent interactions. Royal Society Open Science. 2017; 4 (3):160926.
Chicago/Turabian StyleFabiano L. Ribeiro; Joao Meirelles; Fernando F. Ferreira; Camilo Rodrigues Neto. 2017. "A model of urban scaling laws based on distance dependent interactions." Royal Society Open Science 4, no. 3: 160926.
How can individual acts amount to coherent systems of interaction? In this paper, we attempt to answer this key question by suggesting that there is a place for cities in the way we coordinate seemingly chaotic decisions. We look into the elementary processes of social interaction exploring a particular concept, “social entropy,” or how social systems deal with uncertainty and unpredictability in the transition from individual actions to systems of interaction. Examining possibilities that (i) actions rely on informational differences latent in their environments and that (ii) the city itself is an information environment to actions, we propose that (iii) space becomes a form of creating differences in the probabilities of interaction. We investigate this process through simulations of distinct material scenarios, to find that space is a necessary but not sufficient condition for the reduction of entropy. Finally, we suggest that states and fluctuations of entropy are a vital part of social reproduction and reveal a deep connection between social, informational, and spatial systems.
Vinicius M. Netto; João Vitor Meirelles; Fabiano L. Ribeiro. Social Interaction and the City: The Effect of Space on the Reduction of Entropy. 2017, 1 .
AMA StyleVinicius M. Netto, João Vitor Meirelles, Fabiano L. Ribeiro. Social Interaction and the City: The Effect of Space on the Reduction of Entropy. . 2017; ():1.
Chicago/Turabian StyleVinicius M. Netto; João Vitor Meirelles; Fabiano L. Ribeiro. 2017. "Social Interaction and the City: The Effect of Space on the Reduction of Entropy." , no. : 1.
In this work, some phenomenological growth models based only on the population information (macroscopic level) are deduced in an intuitive way. These models, for instance Verhulst, Gompertz and Bertalanffy-Richards models, are introduced in such a way that all the parameters involved have a physical interpretation. A model based on the interaction (distance dependent) between the individuals (microscopic level) is also presented. This microscopic model have some phenomenological models as particular cases. In this approach, the Verhulst model represents the situation in which all the individuals interact in the same way, regardless of the distance between them (mean field approach). Other phenomenological models are retrieved from the microscopic model according to two quantities: i) the way that the interaction decays as a function the distance between two individuals and ii) the dimension of the spatial structure formed by the individuals of the population. This microscopic model allows understanding population growth by first principles, because it predicts that some phenomenological models can be seen as a consequence of interaction at individual level. The microscopic model discussed here paves the way to finding universal patterns that are common to all types of growth, even in systems of very different nature.
Fabiano L. Ribeiro. An attempt to unify some population growth models from first principles. Revista Brasileira de Ensino de Física 2016, 39, 1 .
AMA StyleFabiano L. Ribeiro. An attempt to unify some population growth models from first principles. Revista Brasileira de Ensino de Física. 2016; 39 (1):1.
Chicago/Turabian StyleFabiano L. Ribeiro. 2016. "An attempt to unify some population growth models from first principles." Revista Brasileira de Ensino de Física 39, no. 1: 1.
The comprehension of tumor growth is a intriguing subject for scientists. New researches has been constantly required to better understand the complexity of this phenomenon. In this paper, we pursue a physical description that account for some experimental facts involving avascular tumor growth. We have proposed an explanation of some phenomenological (macroscopic) aspects of tumor, as the spatial form and the way it growths, from a individual-level (microscopic) formulation. The model proposed here is based on a simple principle: competitive interaction between the cells dependent on their mutual distances. As a result, we reproduce many empirical evidences observed in real tumors, as exponential growth in their early stages followed by a power law growth. The model also reproduces the fractal space distribution of tumor cells and the universal behavior presented in animals and tumor growth, conform reported by West, Guiot {\it et. al.}\cite{West2001,Guiot2003}. The results suggest that the universal similarity between tumor and animal growth comes from the fact that both are described by the same growth equation - the Bertalanffy-Richards model - even they does not necessarily share the same biophysical properties.
Fabiano L. Ribeiro; Renato Vieira Dos Santos; Angélica S. Mata. Fractal Dimension and Universality in Avascular Tumor Growth. 2016, 1 .
AMA StyleFabiano L. Ribeiro, Renato Vieira Dos Santos, Angélica S. Mata. Fractal Dimension and Universality in Avascular Tumor Growth. . 2016; ():1.
Chicago/Turabian StyleFabiano L. Ribeiro; Renato Vieira Dos Santos; Angélica S. Mata. 2016. "Fractal Dimension and Universality in Avascular Tumor Growth." , no. : 1.
We propose some models of single species with Allee effect based on physical principles. A method is used to obtain the expression for the per capita growth rate (a macroscopic information) starting from the characteristics of interactions between the individuals (a microscopic information). We assume that the agents in a model of a single species interact according to the distance between them. Moreover these agents must (i) cooperate with their nearest neighbors, (ii) compete with neighbors at an intermediate distance, and (iii) being indifferent to those who are far away. Using these assumptions and based on fundamental physical principles, we find what appears to be a new way of establishing models of single species with Allee effect.
Renato Vieira Dos Santos; Fabiano L. Ribeiro; Alexandre Souto Martinez. Models for Allee effect based on physical principles. Journal of Theoretical Biology 2015, 385, 143 -152.
AMA StyleRenato Vieira Dos Santos, Fabiano L. Ribeiro, Alexandre Souto Martinez. Models for Allee effect based on physical principles. Journal of Theoretical Biology. 2015; 385 ():143-152.
Chicago/Turabian StyleRenato Vieira Dos Santos; Fabiano L. Ribeiro; Alexandre Souto Martinez. 2015. "Models for Allee effect based on physical principles." Journal of Theoretical Biology 385, no. : 143-152.