Journal of Physics Complexity最新文献_第10页

Minor extensions of the logistic equation for growth curves of word counts on online media: parametric observation of diversity of growth in society 网络媒体字数增长曲线逻辑方程的小扩展：社会增长多样性的参数观察

IF 2.7

Journal of Physics Complexity Pub Date : 2022-11-30 DOI: 10.1088/2632-072X/acda72

Hayafumi Watanabe

{"title":"Minor extensions of the logistic equation for growth curves of word counts on online media: parametric observation of diversity of growth in society","authors":"Hayafumi Watanabe","doi":"10.1088/2632-072X/acda72","DOIUrl":"https://doi.org/10.1088/2632-072X/acda72","url":null,"abstract":"To understand the growth phenomena in collective human systems, we analyzed monthly word count time series of new vocabularies extracted from approximately 1 billion Japanese blog articles from 2007 to 2019. In particular, we first introduced the extended logistic equation by adding one parameter to the original equation and showed that the model can consistently reproduce various patterns of actual growth curves, such as the logistic function, linear growth, and finite-time divergence. Second, by analyzing the model parameters, we found that the typical growth pattern is not only a logistic function, which often appears in various complex systems, but also a non-trivial growth curve that starts with an exponential function and asymptotically approaches a power function without a steady state. We also observed a connection between the functional form of growth and the peak-out behavior. Finally, we showed that the proposed model and statistical properties are also valid for Google Trends data (English, French, Spanish, and Japanese), which is a time series of the nationwide popularity of search queries.","PeriodicalId":53211,"journal":{"name":"Journal of Physics Complexity","volume":" ","pages":""},"PeriodicalIF":2.7,"publicationDate":"2022-11-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45488355","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

The stochastic nature of power-grid frequency in South Africa 南非电网频率的随机性

IF 2.7

Journal of Physics Complexity Pub Date : 2022-11-10 DOI: 10.1088/2632-072X/acb629

Leonardo Rydin Gorjão, J. Maritz

引用次数: 2

Klaus Hasselmann and Economics 克劳斯·哈塞尔曼与经济学

IF 2.7

Journal of Physics Complexity Pub Date : 2022-11-03 DOI: 10.1088/2632-072X/ac956e

C. Jaeger

{"title":"Klaus Hasselmann and Economics","authors":"C. Jaeger","doi":"10.1088/2632-072X/ac956e","DOIUrl":"https://doi.org/10.1088/2632-072X/ac956e","url":null,"abstract":"Klaus Hasselmann has earned the 2021 Nobel Prize in physics for his breakthroughs in analysing the climate system as a complex physical system. Since decades, as a leading climate scientist he is aware of the need for creative cooperation between climate scientists and researchers from other fields, especially economics. To facilitate such cooperation, he has designed a productive research program for economic analysis in view of climate change. Without blurring the differences between economics and physics, the Hasselmann program stresses the complexities of today’s economy. This includes the importance of heterogeneous actors and different time scales, of making major uncertainties explicit and bringing researchers and practitioners in close interaction. The program has triggered decades of collaborative research, especially in the network of the Global Climate Forum, that he has founded for this purpose. Research inspired by Hasselmann’s innovative ideas has led to a farewell to outdated economic approaches: single-equilibrium models, a single constant discount rate, framing the climate challenge as a kind of prisoner’s dilemma and framing it as a problem of scarcity requiring sacrifices from the majority of today’s population. Instead of presenting the climate problem as the ultimate apocalyptic narrative, he sees it as a challenge to be mastered. To meet this challenge requires careful research in order to identify underutilisation of human, technical and social capacities that offer the keys to a climate friendly world economy. Climate neutrality may then be achieved by activating these capacities through investment-oriented climate strategies, designed and implemented by different actors both in industrialised and developing countries. The difficulties to bring global greenhouse gas emissions down to net zero are enormous; the Hasselmann program holds promise of significant advances in this endeavour.","PeriodicalId":53211,"journal":{"name":"Journal of Physics Complexity","volume":" ","pages":""},"PeriodicalIF":2.7,"publicationDate":"2022-11-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47423294","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

General Vapnik–Chervonenkis dimension bounds for quantum circuit learning 量子电路学习的一般Vapnik-Chervonenkis维限

IF 2.7

Journal of Physics Complexity Pub Date : 2022-11-02 DOI: 10.1088/2632-072X/ac9f9b

Chih-Chieh Chen, Masaru Sogabe, Kodai Shiba, K. Sakamoto, T. Sogabe

引用次数: 1

Permutation entropy of indexed ensembles: quantifying thermalization dynamics 索引系综的排列熵：量化热化动力学

IF 2.7

Journal of Physics Complexity Pub Date : 2022-10-27 DOI: 10.1088/2632-072X/acd742

A. Aragoneses, A. Kapulkin, Arjendu K. Pattanayak

{"title":"Permutation entropy of indexed ensembles: quantifying thermalization dynamics","authors":"A. Aragoneses, A. Kapulkin, Arjendu K. Pattanayak","doi":"10.1088/2632-072X/acd742","DOIUrl":"https://doi.org/10.1088/2632-072X/acd742","url":null,"abstract":"We introduce ‘PI-Entropy’ Π(ρ˜) (the Permutation entropy of an Indexed ensemble) to quantify mixing due to complex dynamics for an ensemble ρ of different initial states evolving under identical dynamics. We find that Π(ρ˜) acts as an excellent proxy for the thermodynamic entropy S(ρ) but is much more computationally efficient. We study 1-D and 2D iterative maps and find that Π(ρ˜) dynamics distinguish a variety of system time scales and track global loss of information as the ensemble relaxes to equilibrium. There is a universal S-shaped relaxation to equilibrium for generally chaotic systems, and this relaxation is characterized by a shuffling timescale that correlates with the system’s Lyapunov exponent. For the Chirikov Standard Map, a system with a mixed phase space where the chaos grows with nonlinear kick strength K, we find that for high K, Π(ρ˜) behaves like the uniformly hyperbolic 2D Cat Map. For low K we see periodic behavior with a relaxation envelope resembling those of the chaotic regime, but with frequencies that depend on the size and location of the initial ensemble in the mixed phase space as well as K. We discuss how Π(ρ˜) adapts to experimental work and its general utility in quantifying how complex systems change from a low entropy to a high entropy state.","PeriodicalId":53211,"journal":{"name":"Journal of Physics Complexity","volume":" ","pages":""},"PeriodicalIF":2.7,"publicationDate":"2022-10-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45174614","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Synchronization of online social rhythms via avatar communications 通过化身通信同步在线社交节奏

IF 2.7

Journal of Physics Complexity Pub Date : 2022-10-26 DOI: 10.1088/2632-072X/acbd7d

Masanori Takano

引用次数: 0

Coexistence of coordination and anticoordination in nonlinear public goods game 非线性公共产品博弈中的协调与反协调共存

IF 2.7

Journal of Physics Complexity Pub Date : 2022-10-19 DOI: 10.1088/2632-072X/ac9bc0

Arunava Patra, V. Dubey, S. Chakraborty

引用次数: 0

Identification of city motifs: a method based on modularity and similarity between hierarchical features of urban networks 城市主题识别：一种基于模块化和城市网络层次特征相似性的方法

IF 2.7

Journal of Physics Complexity Pub Date : 2022-10-18 DOI: 10.1088/2632-072X/ac9446

G. Domingues, Eric K. Tokuda, L. da F Costa

{"title":"Identification of city motifs: a method based on modularity and similarity between hierarchical features of urban networks","authors":"G. Domingues, Eric K. Tokuda, L. da F Costa","doi":"10.1088/2632-072X/ac9446","DOIUrl":"https://doi.org/10.1088/2632-072X/ac9446","url":null,"abstract":"Several natural and theoretical networks can be broken down into smaller portions, henceforth called neighborhoods. The more frequent of these can then be understood as motifs of the network, being therefore important for better characterizing and understanding of its overall structure. Several developments in network science have relied on this interesting concept, with ample applications in areas including systems biology, computational neuroscience, economy and ecology. The present work aims at reporting a methodology capable of automatically identifying motifs respective to streets networks, i.e. graphs obtained from city plans by considering street junctions and terminations as nodes while the links are defined by the streets. Interesting results are described, including the identification of nine characteristic motifs, which have been obtained by three important considerations: (i) adoption of five hierarchical measurements to locally characterize the neighborhoods of nodes in the streets networks; (ii) adoption of an effective coincidence similarity methodology for translating datasets into networks; and (iii) definition of the motifs in statistical terms by using community finding methodology. The nine identified motifs are characterized and discussed from several perspectives, including their mutual similarity, visualization, histograms of measurements, and geographical adjacency in the original cities. Also presented is the analysis of the effect of the adopted features on the obtained networks as well as a simple supervised learning method capable of assigning reference motifs to cities.","PeriodicalId":53211,"journal":{"name":"Journal of Physics Complexity","volume":" ","pages":""},"PeriodicalIF":2.7,"publicationDate":"2022-10-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45897967","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 2

Dynamical fluctuations of a tracer coupled to active and passive particles 与主动和被动粒子耦合的示踪剂的动力学波动

IF 2.7

Journal of Physics Complexity Pub Date : 2022-10-11 DOI: 10.1088/2632-072X/acbf1a

Ion Santra

{"title":"Dynamical fluctuations of a tracer coupled to active and passive particles","authors":"Ion Santra","doi":"10.1088/2632-072X/acbf1a","DOIUrl":"https://doi.org/10.1088/2632-072X/acbf1a","url":null,"abstract":"We study the induced dynamics of an inertial tracer particle elastically coupled to passive or active Brownian particles. We integrate out the environment degrees of freedom to obtain the exact effective equation of the tracer—a generalized Langevin equation in both cases. In particular, we find the exact form of the dissipation kernel and effective noise experienced by the tracer and compare it with the phenomenological modeling of active baths used in previous studies. We show that the second fluctuation-dissipation relation (FDR) does not hold at early times for both cases. However, at finite times, the tracer dynamics violate (obeys) the FDR for the active (passive) environment. We calculate the linear response formulas in this regime for both cases and show that the passive medium satisfies an equilibrium fluctuation response relation, while the active medium does not—we quantify the extent of this violation explicitly. We show that though the active medium generally renders a nonequilibrium description of the tracer, an effective equilibrium picture emerges asymptotically in the small activity limit of the medium. We also calculate the mean squared velocity and mean squared displacement of the tracer and report how they vary with time.","PeriodicalId":53211,"journal":{"name":"Journal of Physics Complexity","volume":" ","pages":""},"PeriodicalIF":2.7,"publicationDate":"2022-10-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43784161","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 1

Local multifractality in urban systems—the case study of housing prices in the greater Paris region 城市系统中的局部多重分形——以大巴黎地区房价为例

IF 2.7

Journal of Physics Complexity Pub Date : 2022-10-04 DOI: 10.1088/2632-072X/ac9772

J. Lengyel, S. Roux, P. Abry, F. Sémécurbe, S. Jaffard

{"title":"Local multifractality in urban systems—the case study of housing prices in the greater Paris region","authors":"J. Lengyel, S. Roux, P. Abry, F. Sémécurbe, S. Jaffard","doi":"10.1088/2632-072X/ac9772","DOIUrl":"https://doi.org/10.1088/2632-072X/ac9772","url":null,"abstract":"Even though the study of fractal and multifractal properties has now become an established approach for statistical urban data analysis, the accurate multifractal characterisation of smaller, district-scale spatial units is still a somewhat challenging task. The latter issue is key for understanding complex spatial correlations within urban regions while the methodological challenge can be mainly attributed to inhomogeneous data availability over their territories. We demonstrate how the approach proposed here for the multifractal analysis of irregular marked point processes is able to estimate local self-similarity and intermittency exponents in a satisfactory manner via combining methods from classical multifractal and geographical analysis. With the aim of emphasizing general applicability, we first introduce the procedure on synthetic data using a multifractal random field as mark superposed on two distinct spatial distributions. We go on to illustrate the methodology on the example of home prices in the greater Paris region, France. In the context of complex urban systems, our findings proclaim the need for separately tackling processes on the geolocation (support) and any attached value (mark, e.g. home prices) of geospatial data points in an attempt to fully describe the phenomenon under observation. In particular, the results are indicators of the strength of global and local spatial dependency in the housing price structure and how these build distinct layered patterns within and outside of the municipal boundary. The derived properties are of potential urban policy and strategic planning relevance for the timely identification of local vulnerabilities while they are also intended to be combinable with existing price indices in the regional economics context.","PeriodicalId":53211,"journal":{"name":"Journal of Physics Complexity","volume":" ","pages":""},"PeriodicalIF":2.7,"publicationDate":"2022-10-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47347191","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 1