1,721,172 research outputs found
Social physics: uncovering human behaviour from communication
No full text| openaire: EC/H2020/654024/EU//SoBigData | openaire: EC/H2020/662725/EU//IBSENIn the post year 2000 era the technologies that facilitate human communication have rapidly multiplied. While the adoption of these technologies has hugely impacted the behaviour and sociality of people, specifically in urban but also in rural environments, their "digital footprints' on different data bases have become an active area of research. The existence and accessibility of such large population-level datasets, has allowed scientists to study and model innate human tendencies and social patterns in an unprecedented way that complements traditional research approaches like questionnaire studies. In this review, we focus on data analytics and modelling research - along the lines of Social Physics - as it has been carried out using the mobile phone datasets to get insight into the various aspects of human sociality, burstiness in communication, mobility patterns, and daily rhythms.Peer reviewe
Enhanced robustness of evolving open systems by the bidirectionality of interactions between elements
No full text| openaire: EC/H2020/662725/EU//IBSENLiving organisms, ecosystems, and social systems are examples of complex systems in which robustness against inclusion of new elements is an essential feature. A recently proposed simple model has revealed a general mechanism by which such systems can become robust against inclusion of elements with totally random interactions when the elements have a moderate number of links. The interaction is, however, in many systems often intrinsically bidirectional like for mutual symbiosis and competition in ecology. This study reports the strong reinforcement effect of the bidirectionality of the interactions on the robustness of evolving systems. We show that the system with purely bidirectional interactions can grow with twofold average degree, in comparison with the purely unidirectional system. This drastic shift of the transition point comes from the reinforcement of each node, not from a change in structure of the emergent system. For systems with partially bidirectional interactions we find that the regime of the growing phase gets expanded. In the dense interaction regime, there exists an optimum proportion of bidirectional interactions for the growth rate at around 1/3. In the sparsely connected systems, small but finite fraction of bidirectional links can change the system's behaviour from non-growing to growing.Peer reviewe
Ecology of the digital world of Wikipedia
No full text| openaire: EC/H2020/871042/EU//SoBigData-PlusPlus Funding Information: FO was partly supported by JSPS KAKENHI grant number 21K19826. JK and KK acknowledge support from EU HORIZON 2020 INFRAIA-2019-1 (SoBigData++) No. 871042. KK also acknowledges the Visiting Fellowship at The Alan Turing Institute, UK. TS was partly supported by JSPS KAKENHI grant number 18K03449. FO, JK, and TS thank for hospitality of Aalto University. Publisher Copyright: © 2021, The Author(s).Wikipedia, a paradigmatic example of online knowledge space is organized in a collaborative, bottom-up way with voluntary contributions, yet it maintains a level of reliability comparable to that of traditional encyclopedias. The lack of selected professional writers and editors makes the judgement about quality and trustworthiness of the articles a real challenge. Here we show that a self-consistent metrics for the network defined by the edit records captures well the character of editors’ activity and the articles’ level of complexity. Using our metrics, one can better identify the human-labeled high-quality articles, e.g., “featured” ones, and differentiate them from the popular and controversial articles. Furthermore, the dynamics of the editor-article system is also well captured by the metrics, revealing the evolutionary pathways of articles and diverse roles of editors. We demonstrate that the collective effort of the editors indeed drives to the direction of article improvement.Peer reviewe
Detailed-level modelling of influence spreading on complex networks
No full textPublisher Copyright: © The Author(s) 2024.The progress in high-performance computing makes it increasingly possible to build detailed models to investigate spreading processes on complex networks. However, current studies have been lacking detailed computational methods to describe spreading processes in large complex networks. To fill this gap we present a new modelling approach for analysing influence spreading via individual nodes and links on various network structures. The proposed influence-spreading model uses a probability matrix to capture the spreading probability from one node to another in the network. This approach enables analysing network characteristics in a number of applications and spreading processes using metrics that are consistent with the quantities used to model the network structures. In addition, this study combines sub-models and offers a comprehensive look at different applications and metrics previously discussed in cases of social networks, community detection, and epidemic spreading. Here, we also note that the centrality measures based on the probability matrix are used to identify the most significant nodes in the network. Furthermore, the model can be expanded to include additional properties, such as introducing individual breakthrough probabilities for the nodes and specific temporal distributions for the links.Peer reviewe
Social structure formation in a network of agents playing a hybrid of ultimatum and dictator games
No full text| openaire: EC/H2020/654024/EU//SoBigDataHere we present an agent-based model where agents interact with other agents by playing a hybrid of dictator and ultimatum games in a co-evolving social network. The basic assumption about the behaviour of the agents in both games is that they try to attain superior socioeconomic positions relative to other agents. As the model parameters we have chosen the relative proportions of the dictator and ultimatum game strategies being played between a pair of agents in a single social transaction and a parameter depicting the living costs of the agents. The motivation of the study is to examine how different types of social interactions affect the formation of social structures and networks, when the agents have a tendency to maximise their socioeconomic standing. We find that such social networks of agents invariably undergo a community formation process from simple chain-like structure to more complex networks as the living cost parameter is increased. The point where this occurs, depends also on the relative proportion of the dictator and ultimatum games being played. We find that it is harder for complex social structures to form when the dictator game strategy in social transactions of agents becomes more dominant over that of the ultimatum game.Peer reviewe
Stochastic block model reveals maps of citation patterns and their evolution in time
No full text| openaire: EC/H2020/654024/EU//SoBigDataIn this study we map out the large-scale structure of citation networks of science journals and follow their evolution in time by using stochastic block models (SBMs). The SBM fitting procedures are principled methods that can be used to find hierarchical grouping of journals that show similar incoming and outgoing citations patterns. These methods work directly on the citation network without the need to construct auxiliary networks based on similarity of nodes. We fit the SBMs to the networks of journals we have constructed from the data set of around 630 million citations and find a variety of different types of groups, such as communities, bridges, sources, and sinks. In addition we use a recent generalization of SBMs to determine how much a manually curated classification of journals into subfields of science is related to the group structure of the journal network and how this relationship changes in time. The SBM method tries to find a network of blocks that is the best high-level representation of the network of journals, and we illustrate how these block networks (at various levels of resolution) can be used as maps of science.Peer reviewe
Temporal inactivation enhances robustness in an evolving system
No full text| openaire: EC/H2020/662725/EU//IBSEN | openaire: EC/H2020/654024/EU//SoBigDataWe study the robustness of an evolving system that is driven by successive inclusions of new elements or constituents with m random interactions to older ones. Each constitutive element in the model stays either active or is temporarily inactivated depending upon the influence of the other active elements. If the time spent by an element in the inactivated state reaches T W , it gets extinct. The phase diagram of this dynamic model as a function of m and T W is investigated by numerical and analytical methods and as a result both growing (robust) as well as non-growing (volatile) phases are identified. It is also found that larger time limit T W enhances the system's robustness against the inclusion of new elements, mainly due to the system's increased ability to reject 'falling-together' type attacks. Our results suggest that the ability of an element to survive in an unfavourable situation for a while, either as a minority or in a dormant state, could improve the robustness of the entire system.Peer reviewe
Frustrated opinion dynamics on real networks and its predictors
No full textPublisher Copyright: Copyright © 2023 Kuroda, Kaski and Shimada.Indirect reciprocity is a type of social dynamics in which the attitude of an individual toward another individual is either cooperative or antagonistic, and it can change over time through their actions and mutual monitoring. This opinion dynamics is found to be frustrating in certain edge density regimes on random graphs when all the components adopt the Kandori rule, which is one of the norms of indirect reciprocity. In this study, we conducted an exhaustive analysis of so-called “leading-eight” norms of indirect reciprocity dynamics and found that three of them (the Kandori and other two rules) keep the opinion dynamics frustrated on random graphs. We investigated the frustrated opinion dynamics of these three norms on real acquaintance networks and observed that the degree of frustration of the system can be inferred when the network properties such as the number of triangular connections and number of quads are properly taken into account. This study also reveals that the closeness centrality of a triangular representation is a good predictor of the degree of local frustration. Furthermore, it is also found that better prediction is achieved when we do not consider all the reachable triads in the calculation of a focal triad’s closeness centrality. This result suggests that it is sufficient to predict the opinion dynamics by considering only the proximity triads within a certain observation radius from that triad. This finding may facilitate the analysis of real-world cooperative relationships consisting of a vast number of triads.Peer reviewe
Differences of communication activity and mobility patterns between urban and rural people
No full text| openaire: EC/H2020/654024/EU//SoBigData | openaire: EC/H2020/871042/EU//SoBigData-PlusPlusHuman mobility and other social activity patterns influence various aspects of society such as urban planning, traffic predictions, crisis resilience, and epidemic prevention. The behaviour of individuals, like their communication frequencies and movements, are shaped by societal and socio-economic factors. In addition, the differences in the geolocation of people as well as their gender and age cast effects on their activity patterns. In this study we focus on investigating these patterns by using mobile phone data, specifically the call detail records (CDRs), to analyze the social communication and mobility patterns of people. This dataset can provide us insight into the individual and population-level behaviours in rural and urban environments on a daily, weekly and seasonal basis. The results of our analyses show that in the urban areas people have high calling activity but low mobility, while in the rural areas they show the opposite behaviour, i.e. low calling activity combined with high mobility. Overall, there is a decreasing trend in people’s mobility through the year even though their calling activity remained consistent except for the holidays during which time the communication frequency drops markedly. We have also observed that there are significant differences in the mobility between the work days and free days. Finally, the age and gender of individuals have also been observed to play a role in the seasonal patterns differently in urban and rural areas.Peer reviewe
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