| | SLO | ENG | Cookies and privacy

Bigger font | Smaller font

Search the digital library catalog Help

Query: search in
search in
search in
search in
* old and bologna study programme

Options:
  Reset


1 - 10 / 80
First pagePrevious page12345678Next pageLast page
1.
Local and global stimuli in reinforcement learning
Danyang Jia, Hao Guo, Zhao Song, Lei Shi, Xinyang Deng, Matjaž Perc, Zhen Wang, 2021, original scientific article

Abstract: In efforts to resolve social dilemmas, reinforcement learning is an alternative to imitation and exploration in evolutionary game theory. While imitation and exploration rely on the performance of neighbors, in reinforcement learning individuals alter their strategies based on their own performance in the past. For example, according to the Bush-Mosteller model of reinforcement learning, an individual's strategy choice is driven by whether the received payoff satisfies a preset aspiration or not. Stimuli also play a key role in reinforcement learning in that they can determine whether a strategy should be kept or not. Here we use the Monte Carlo method to study pattern formation and phase transitions towards cooperation in social dilemmas that are driven by reinforcement learning. We distinguish local and global players according to the source of the stimulus they experience. While global players receive their stimuli from the whole neighborhood, local players focus solely on individual performance. We show that global players play a decisive role in ensuring cooperation, while local players fail in this regard, although both types of players show properties of "moody cooperators". In particular, global players evoke stronger conditional cooperation in their neighborhoods based on direct reciprocity, which is rooted in the emerging spatial patterns and stronger interfaces around cooperative clusters.
Keywords: evolutionary game theory, cooperation, learning, social physics
Published in DKUM: 03.03.2025; Views: 0; Downloads: 0
.pdf Full text (5,68 MB)
This document has many files! More...

2.
The self-organizing impact of averaged payoffs on the evolution of cooperation
Attila Szolnoki, Matjaž Perc, 2021, original scientific article

Abstract: According to the fundamental principle of evolutionary game theory, the more successful strategy in a population should spread. Hence, during a strategy imitation process a player compares its payoff value to the payoff value held by a competing strategy. But this information is not always accurate. To avoid ambiguity a learner may therefore decide to collect a more reliable statistics by averaging the payoff values of its opponents in the neighborhood, and makes a decision afterwards. This simple alteration of the standard microscopic protocol significantly improves the cooperation level in a population. Furthermore, the positive impact can be strengthened by increasing the role of the environment and the size of the evaluation circle. The mechanism that explains this improvement is based on a self-organizing process which reveals the detrimental consequence of defector aggregation that remains partly hidden during face-to-face comparisons. Notably, the reported phenomenon is not limited to lattice populations but remains valid also for systems described by irregular interaction networks.
Keywords: evolutionary game theory, cooperation, learning, social physics
Published in DKUM: 03.03.2025; Views: 0; Downloads: 0
.pdf Full text (2,21 MB)
This document has many files! More...

3.
Seasonal payoff variations and the evolution of cooperation in social dilemmas
Attila Szolnoki, Matjaž Perc, 2019, original scientific article

Abstract: Varying environmental conditions affect relations between interacting individuals in social dilemmas, thus affecting also the evolution of cooperation. Oftentimes these environmental variations are seasonal and can therefore be mathematically described as periodic changes. Accordingly, we here study how periodic shifts between different manifestations of social dilemmas affect cooperation. We observe a non-trivial interplay between the inherent spatiotemporal dynamics that characterizes the spreading of cooperation in a particular social dilemma type and the frequency of payoff changes. In particular, we show that periodic changes between two available games with global ordering best be fast, while periodic changes between global and local ordering games best be slow for cooperation to thrive. We also show that the frequency of periodic changes between two local ordering social dilemmas is irrelevant, because then the process is fast and simply the average cooperation level of the two is returned. The structure of the interaction network plays an important role too in that lattices promote local ordering, whilst random graphs hinder the formation of compact cooperative clusters. Conversely, for local ordering the regular structure of the interaction network is only marginally relevant as role-separating checkerboard patterns do not rely on long-range order.
Keywords: cooperation, social dilemma, social physics, phase transition, mixed games
Published in DKUM: 26.02.2025; Views: 0; Downloads: 2
.pdf Full text (1,69 MB)
This document has many files! More...

4.
Evolutionary dynamics of any multiplayer game on regular graphs
Chaoqian Wang, Matjaž Perc, Attila Szolnoki, 2024, original scientific article

Abstract: Multiplayer games on graphs are at the heart of theoretical descriptions of key evolutionary processes that govern vital social and natural systems. However, a comprehensive theoretical framework for solving multiplayer games with an arbitrary number of strategies on graphs is still missing. Here, we solve this by drawing an analogy with the Balls-and-Boxes problem, based on which we show that the local configuration of multiplayer games on graphs is equivalent to distributing k identical co-players among n distinct strategies. We use this to derive the replicator equation for any n-strategy multiplayer game under weak selection, which can be solved in polynomial time. As an example, we revisit the second-order free-riding problem, where costly punishment cannot truly resolve social dilemmas in a well-mixed population. Yet, in structured populations, we derive an accurate threshold for the punishment strength, beyond which punishment can either lead to the extinction of defection or transform the system into a rock-paper-scissors-like cycle. The analytical solution also qualitatively agrees with the phase diagrams that were previously obtained for non-marginal selection strengths. Our framework thus allows an exploration of any multi-strategy multiplayer game on regular graphs.
Keywords: evolutionary game theory, cooperation, network, social physics
Published in DKUM: 26.02.2025; Views: 0; Downloads: 3
.pdf Full text (5,41 MB)
This document has many files! More...

5.
Unified digital law enforcement environment - necessity and prospects for creation in the "BRICS countries"
Evgenii Nikitin, Cocou Marius Mensah, 2020, original scientific article

Abstract: The article examines the prospects for the development of an interstate association of BRICS member nations and concludes that it is necessary to expand cooperation in addition to the economic sphere through other areas, in particular, the organization of interaction to combat crime. The article focuses on the fact that an important area of joint cooperation between the BRICS member nations will be activities in the field of security and combating crime. The main promising areas of cooperation between the BRICS member nations in the field of security are formulated and forms of joint activities in these areas are proposed. This area of cooperation of the BRICS member nations should be based on modern information technologies, which is due to the need for coordination of law enforcement activities of the BRICS member nations. The article analyzes the joint system for preventing international crime in the BRICS member nations and concludes that no improvement of this system is possible without appropriate information support for law enforcement based on general principles and approaches. To this end, the necessity of creating a Unified Digital Environment for Law Enforcement Services in the BRICS member nations is substantiated, which implies the speed of achieving the objectives of law enforcement in the BRICS member nations; reduction of corruption risks in this area; as well as automation of individual work processes by replacing a human resource with software. The article describes the concept of a Unified Digital Environment for Law Enforcement Services of the BRICS member nations, substantiates the components that make up its structure. The modern methods of information processing that can be used to build the specified information system are presented. Possible interested users of this environment are highlighted and the capabilities of the Unified Digital BRICS Law Enforcement Services Environment provided to these users are presented.
Keywords: digital law, digitalization of law, information technology, law enforcement, BRICS, international cooperation, fight against crime, law digital environments
Published in DKUM: 30.01.2025; Views: 0; Downloads: 5
.pdf Full text (1,10 MB)
This document has many files! More...

6.
Cooperation on interdependent networks by means of migration and stochastic imitation
Sayantan Nag Chowdhury, Srilena Kundu, Maja Duh, Matjaž Perc, Dibakar Ghosh, 2020, original scientific article

Abstract: Evolutionary game theory in the realm of network science appeals to a lot of research communities, as it constitutes a popular theoretical framework for studying the evolution of cooperation in social dilemmas. Recent research has shown that cooperation is markedly more resistant in interdependent networks, where traditional network reciprocity can be further enhanced due to various forms of interdependence between different network layers. However, the role of mobility in interdependent networks is yet to gain its well-deserved attention. Here we consider an interdependent network model, where individuals in each layer follow different evolutionary games, and where each player is considered as a mobile agent that can move locally inside its own layer to improve its fitness. Probabilistically, we also consider an imitation possibility from a neighbor on the other layer. We show that, by considering migration and stochastic imitation, further fascinating gateways to cooperation on interdependent networks can be observed. Notably, cooperation can be promoted on both layers, even if cooperation without interdependence would be improbable on one of the layers due to adverse conditions. Our results provide a rationale for engineering better social systems at the interface of networks and human decision making under testing dilemmas.
Keywords: cooperation, interdependent networks, mobile agents, prisoner's dilemma, snowdrift game, game theory, mobility, rational agents
Published in DKUM: 15.01.2025; Views: 0; Downloads: 5
.pdf Full text (3,51 MB)
This document has many files! More...

7.
Ranking the invasions of cheaters in structured populations
Guoli Yang, Matteo Cavaliere, Cheng Zhu, Matjaž Perc, 2020, original scientific article

Abstract: The identification of the most influential individuals in structured populations is an important research question, with many applications across the social and natural sciences. Here, we study this problem in evolutionary populations on static networks, where invading cheaters can lead to the collapse of cooperation. We propose six strategies to rank the invading cheaters and identify those which mostly facilitate the collapse of cooperation. We demonstrate that the type of successful rankings depend on the selection strength, the underlying game, and the network structure. We show that random ranking has generally little ability to successfully identify invading cheaters, especially for the stag-hunt game in scale-free networks and when the selection strength is strong. The ranking based on degree can successfully identify the most influential invaders when the selection strength is weak, while more structured rankings perform better at strong selection. Scale-free networks and strong selection are generally detrimental to the performance of the random ranking, but they are beneficial for the performance of structured rankings. Our research reveals how to identify the most influential invaders using statistical measures in structured communities, and it demonstrates how their success depends on population structure, selection strength, and on the underlying game dynamics.
Keywords: cooperation, cheating, network, population, evolution
Published in DKUM: 07.01.2025; Views: 0; Downloads: 4
.pdf Full text (6,72 MB)
This document has many files! More...

8.
Association between productivity and journal impact across disciplines and career age
Andre S. Sunahara, Matjaž Perc, Haroldo V. Ribeiro, 2021, original scientific article

Abstract: The association between productivity and impact of scientific production is a long-standing debate in science that remains controversial and poorly understood. Here we present a large-scale analysis of the association between yearly publication numbers and average journal-impact metrics for the Brazilian scientific elite. We find this association to be discipline specific, career age dependent, and similar among researchers with outlier and nonoutlier performance. Outlier researchers either outperform in productivity or journal prestige, but they rarely do so in both categories. Nonoutliers also follow this trend and display negative correlations between productivity and journal prestige but with discipline-dependent intensity. Our research indicates that academics are averse to simultaneous changes in their productivity and journal-prestige levels over consecutive career years. We also find that career patterns concerning productivity and journal prestige are discipline-specific, having in common a raise of productivity with career age for most disciplines and a higher chance of outperforming in journal impact during early career stages.
Keywords: network, cooperation, social physics, complex system
Published in DKUM: 10.12.2024; Views: 0; Downloads: 8
.pdf Full text (1,10 MB)
This document has many files! More...

9.
Diverse strategic identities induce dynamical states in evolutionary games
Irene Sendiña-Nadal, Inmaculada Leyva, Matjaž Perc, David Papo, Marko Jusup, Zhen Wang, Juan A. Almendral, Pouya Manshour, Stefano Boccaletti, 2020, original scientific article

Abstract: Evolutionary games provide the theoretical backbone for many aspects of our social life: from cooperation to crime, from climate inaction to imperfect vaccination and epidemic spreading, from antibiotics overuse to biodiversity preservation. An important, and so far overlooked, aspect of reality is the diverse strategic identities of individuals. While applying the same strategy to all interaction partners may be an acceptable assumption for simpler forms of life, this fails to account for the behavior of more complex living beings. For instance, we humans act differently around different people. Here we show that allowing individuals to adopt different strategies with different partners yields a very rich evolutionary dynamics, including time-dependent coexistence of cooperation and defection, systemwide shifts in the dominant strategy, and maturation in individual choices. Our results are robust to variations in network type and size, and strategy updating rules. Accounting for diverse strategic identities thus has far-reaching implications in the mathematical modeling of social games.
Keywords: cooperation, evolutionary game theory, social physics, collective dynamics, complex system
Published in DKUM: 20.11.2024; Views: 0; Downloads: 4
.pdf Full text (4,71 MB)
This document has many files! More...

10.
Strategically positioning cooperators can facilitate the contagion of cooperation
Guoli Yang, Matteo Cavaliere, Cheng Zhu, Matjaž Perc, 2021, original scientific article

Abstract: The spreading of cooperation in structured population is a challenging problem which can be observed at diferent scales of social and biological organization. Generally, the problem is studied by evaluating the chances that few initial invading cooperators, randomly appearing in a network, can lead to the spreading of cooperation. In this paper we demonstrate that in many scenarios some cooperators are more infuential than others and their initial positions can facilitate the spreading of cooperation. We investigate six diferent ways to add initial cooperators in a network of cheaters, based on diferent network-based measurements. Our research reveals that strategically positioning the initial cooperators in a population of cheaters allows to decrease the number of initial cooperators necessary to successfully seed cooperation. The strategic positioning of initial cooperators can also help to shorten the time necessary for the restoration of cooperation. The optimal ways in which the initial cooperators should be placed is, however, non-trivial in that it depends on the degree of competition, the underlying game, and the network structure. Overall, our results show that, in structured populations, few cooperators, well positioned in strategically chosen places, can spread cooperation faster and easier than a large number of cooperators that are placed badly.
Keywords: cooperation, evolutionary game theory, social physics, collective dynamics, complex system
Published in DKUM: 22.10.2024; Views: 0; Downloads: 3
.pdf Full text (5,68 MB)
This document has many files! More...

Search done in 0.2 sec.
Back to top
Logos of partners University of Maribor University of Ljubljana University of Primorska University of Nova Gorica