Physica A: Statistical Mechanics and its Applications最新文献

{"title":"On the impact of zealots in a population of susceptible agents in a best-of-n problem within a heterogeneous network","authors":"Thierry Njougouo ,&nbsp;Andreagiovanni Reina ,&nbsp;Elio Tuci ,&nbsp;Timoteo Carletti","doi":"10.1016/j.physa.2024.130198","DOIUrl":"10.1016/j.physa.2024.130198","url":null,"abstract":"<div><div>Both humans and social animals live in groups and are frequently forced to choose between options with different qualities. When there are no leader agents controlling the group decision, consensus can be achieved through repeated interactions among group members. Various studies on collective decision-making illustrate how the dynamics of the opinions are determined by the structure of the social network and the methods that individuals use to share and update their opinion upon a social interaction. In this paper, we are interested in further exploring how cognitive, social, and environmental factors interactively contribute to determining the outcome of a collective best-of-<span><math><mi>n</mi></math></span> decision process involving asymmetric options, i.e., different costs and/or benefits for each option. We propose and study a novel model capturing those different factors, (i) the cognitive load in processing social information, (ii) the number of zealots (i.e., asocial agents who never change their opinion), (iii) the option qualities, (iv) the social connectivity structure, and (v) the degree centrality of the asocial agents (i.e., the number of neighbours). By using the heterogeneous mean-field approach, we study the impact of the above-mentioned factors in the decision dynamics. Our findings indicate that when susceptible agents, i.e., individuals who change their opinion to conform with others, use the voter model as a mechanism to update their opinion, both the number and the degree of connectivity of the zealots can lead the population to converge towards the lowest quality option. Instead, when susceptible agents use methods demanding a larger cognitive cost (e.g., the majority rule), the group is marginally impacted by the presence of zealots. The results of the analytical model are complemented and extended by agent-based simulations. Our analysis also shows that the network topology can modulate the influence of zealots on group dynamics. In fact, in homogeneous networks where all nodes have the same degree, any location of the zealots has similar impact on the group dynamics. Instead, when the network is heterogeneous, our simulations confirm the model predictions showing that placing the zealots in the network hubs (nodes with several neighbours) has a much larger impact than placing them in lower-degree nodes.</div></div>","PeriodicalId":20152,"journal":{"name":"Physica A: Statistical Mechanics and its Applications","volume":"655 ","pages":"Article 130198"},"PeriodicalIF":2.8,"publicationDate":"2024-11-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142654976","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Attention-based CNN model for motor imagery classification from nonlinear EEG signals","authors":"Dong-Mei Lv ,&nbsp;Wei-Dong Dang ,&nbsp;Jia-Heng Feng ,&nbsp;Zhong-Ke Gao","doi":"10.1016/j.physa.2024.130191","DOIUrl":"10.1016/j.physa.2024.130191","url":null,"abstract":"<div><div>Motor imagery (MI)-based brain–computer interface (BCI) provides a promising solution for the limb rehabilitation of stroke patients. For better rehabilitation performance, high-precision classification of MI-related EEG signals plays a critical role. However, this is still a challenging problem for multi-category MI signals. In this paper, we focus on four commonly used stroke rehabilitation actions, and propose a modular temporal–spatial attention-based CNN (MTSACNN) model for MI classification. In detail, we carry out the MI experiments and acquire the EEG signals related to imagining left/right fist clenching and left/right wrist dorsiflexion. MTSACNN model firstly extracts the low-order MI features through the temporal–spatial feature extraction module (TSFE module). Especially, a group attention mechanism is proposed for intra-group information interaction. Secondly, considering the short- and long-term working characteristics of brain, high-order temporal features are further extracted and fused by the multi-level feature fusion module (MLFF module). Finally, four auxiliary losses are arranged in the classification module (C module) to speed up the model optimization process. The experimental results show that MTSACNN model can achieve good performance in decoding rehabilitation-related MI brain intentions, achieving an average classification accuracy of 72.05% for fourteen subjects. This work is beneficial to promote the construction of high-performance stroke rehabilitation BCI system.</div></div>","PeriodicalId":20152,"journal":{"name":"Physica A: Statistical Mechanics and its Applications","volume":"655 ","pages":"Article 130191"},"PeriodicalIF":2.8,"publicationDate":"2024-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142655063","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"An unsupervised group detection method for understanding group dynamics in crowds","authors":"Nipun Choubey ,&nbsp;Ashish Verma ,&nbsp;Anirban Chakraborty","doi":"10.1016/j.physa.2024.130195","DOIUrl":"10.1016/j.physa.2024.130195","url":null,"abstract":"<div><div>Pedestrian groups arrive in large numbers in crowd gatherings, especially of a spiritual nature. Various studies have been done on crowd control in public spaces by analysing the behaviour of pedestrian groups. Understanding group dynamics can help better plan pedestrian facilities and large events. Many existing group sensing models primarily determine social bonding between pedestrians using spatiotemporal parameters, such as distance, directional movement, and overlapping time. However, social bonding determined based on these parameters assumes the bonding to be symmetric, spatially and temporally static and is unaffected by neighbourhood. Our study addresses the issue by relaxing such assumptions and developing an unsupervised group detection model based on potential candidates. The proposed model can handle temporal and spatial variations more effectively than those based on simple spatiotemporal parameters. The model developed is assessed both quantitatively and qualitatively. New metrics are introduced for quantitative evaluation, comparing predicted groups and ground truth instead of pedestrian pairs with ground truth. A visualisation method is developed for the qualitative assessment. Group splits and group merges are calculated to assist in understanding crowd movement patterns. Overall, this study helps in further exploring and assessing groups, which can improve understanding of crowd dynamics.</div></div>","PeriodicalId":20152,"journal":{"name":"Physica A: Statistical Mechanics and its Applications","volume":"655 ","pages":"Article 130195"},"PeriodicalIF":2.8,"publicationDate":"2024-10-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142587418","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Intersection eco-driving strategies under mixed traffic environment: An novel cooperation of traffic signal and vehicle trajectory planning","authors":"Heng Ding,&nbsp;Yuan Sun,&nbsp;Liangwen Wang,&nbsp;Xiaoyan Zheng,&nbsp;Wenjuan Huang,&nbsp;Xiaoshan Lu","doi":"10.1016/j.physa.2024.130203","DOIUrl":"10.1016/j.physa.2024.130203","url":null,"abstract":"<div><div>In a mixed traffic environment where connected and autonomous vehicles (CAVs) coexist with human-driven vehicles (HVs), the utilization of CAV information is important for improving eco-driving and reducing energy consumption at signalized intersections. This paper proposes a two-layer control method for signalized intersections that uses CAV information. The upper layer generates a dynamic signal NEMA timing scheme by estimating the virtual arrival times of both HVs and CAVs, to minimize the total vehicle delays. This is achieved through a hybrid heuristic algorithm that integrates sequential genetic algorithms (GA) and particle swarm algorithms (PSO) to identify the optimal signal scheme. The lower layer develops a generic distributed CAV eco-driving strategy based on the optimal signal timings. The strategy considers various factors such as signal state, queue information, the preceding vehicle, and collision avoidance, to optimize the ecological trajectory of CAVs under the mixed traffic flow. An event-triggered update reference eco-trajectory rule is applied to reduce computational cost and handle the impact of traffic uncertainty. Finally, comparative analyses with fixed controls, induction timing controls and max pressure controls show that the proposed method can reduce the average vehicle delays, fuel consumption, and emissions across different traffic conditions and varying CAV penetration rates.</div></div>","PeriodicalId":20152,"journal":{"name":"Physica A: Statistical Mechanics and its Applications","volume":"655 ","pages":"Article 130203"},"PeriodicalIF":2.8,"publicationDate":"2024-10-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142587420","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Optimal control strategy for electric vehicle platoons in dynamic wireless charging lane considering charge demand differences","authors":"Yang Wang ,&nbsp;Minghui Ma ,&nbsp;Shidong Liang ,&nbsp;Yansong Wang ,&nbsp;Ningning Liu","doi":"10.1016/j.physa.2024.130190","DOIUrl":"10.1016/j.physa.2024.130190","url":null,"abstract":"<div><div>During peak traffic hours in merging areas, traffic demand often exceeds supply, making it difficult to eliminate traffic congestion, though it can be mitigated to some extent. As a result, congestion is inevitable. Deploying Dynamic Wireless Charging (DWC) lanes in these low-speed zones can provide electric vehicles with more charging time during unavoidable congestion. Based on this analysis, DWC lanes could be strategically located near frequently congested merging areas. However, by applying certain control measures and guiding vehicles to adjust their speed during congestion, low-battery vehicles can receive more charging time, while high-battery vehicles can accelerate through the merging area, creating a win-win scenario. Existing research focuses on intersections and single-vehicle charging, overlooking potential applications near merging areas and the varying charging needs among vehicles. To address this gap, this paper introduces an optimized control strategy for electric vehicle platoons considering their charging requirements. The proposed scheme assumes DWC lanes are deployed ahead of merging areas in congested ways, leveraging low-speed movement during merging for charging. We assign different charging values to each vehicle based on battery levels, providing a solid basis for control. In order to manage platoons with varying battery capacities, we propose two control schemes for platoon leaders: Self-oriented Control and Group-oriented Control. At the microscopic level, we consider the impact of car-following models on fleet behavior, employing a different car-following models for control. At the macroscopic level, we design experiments on mainline and ramp sections under various Market Penetration Rates (MPRs) to assess the impact of intelligent connected vehicle penetration on traffic flow. Finally, we validate the proposed control strategies using SUMO simulations. Self-oriented Control and Group-oriented Control each prove effective in different scenarios. Furthermore, inappropriate selection of car-following models during simulations may lead to erroneous conclusions. This study underscores the potential of connected and autonomous vehicles in addressing diverse charging needs on DWC facilities.</div></div>","PeriodicalId":20152,"journal":{"name":"Physica A: Statistical Mechanics and its Applications","volume":"655 ","pages":"Article 130190"},"PeriodicalIF":2.8,"publicationDate":"2024-10-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142654977","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Interface-packing analysis of F1-ATPase using integral equation theory and manifold learning","authors":"Takashi Yoshidome,&nbsp;Shota Arai","doi":"10.1016/j.physa.2024.130201","DOIUrl":"10.1016/j.physa.2024.130201","url":null,"abstract":"<div><div>It has been shown that the translational entropy of water plays a key role in biological processes such as protein folding and ligand binding. Under the physiological condition, tightly packed protein conformations like native structures are achieved so that the translational entropy of water is maximized. In this study, we investigate the rotation mechanism of a rotary protein motor, F₁-ATPase, by analyzing the packing at the interfaces between the subunits. The packing at the interface between a subunit pair is analyzed using the change in the solvent entropy upon forming subunit pair, <span><math><mrow><mo>∆</mo><mi>S</mi></mrow></math></span>. It is found that as the γ subunit rotates, the <span><math><mrow><mo>∆</mo><mi>S</mi></mrow></math></span> value of a α-β subunit pair decrease because the interface packing becomes loose. However, because the interface packing of another α-β subunit pair becomes tighter upon the rotation, <span><math><mrow><mo>∆</mo><mi>S</mi></mrow></math></span> of this α-β subunit pair increases, leading to a compensation of the decrease in <span><math><mrow><mo>∆</mo><mi>S</mi></mrow></math></span>. Such compensation would be necessary to maximize the solvent entropy of F₁-ATPase. In this study, packing at the interfaces between the subunits is also analyzed using a manifold-learning technique, and it is suggested a possibility that a qualitative estimation of the <span><math><mrow><mo>∆</mo><mi>S</mi></mrow></math></span> values of some α-β subunit pairs can be predicted using a manifold-learning technique.</div></div>","PeriodicalId":20152,"journal":{"name":"Physica A: Statistical Mechanics and its Applications","volume":"655 ","pages":"Article 130201"},"PeriodicalIF":2.8,"publicationDate":"2024-10-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142587417","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Estimating thresholds for the contact process with permanent immunity on complex networks","authors":"D.S.M. Alencar ,&nbsp;T.F.A. Alves ,&nbsp;F.W.S. Lima ,&nbsp;R.S. Ferreira ,&nbsp;G.A. Alves ,&nbsp;A. Macedo-Filho","doi":"10.1016/j.physa.2024.130183","DOIUrl":"10.1016/j.physa.2024.130183","url":null,"abstract":"<div><div>We present an improvement in estimating the epidemic threshold for a modified susceptible-infected-removed model. We applied the pair heterogeneous mean-field theory on heterogeneous quenched networks. Our theoretical results are compared with extensive Monte Carlo simulations concerning the model dynamics on random regular and power-law networks. The epidemic thresholds obtained using pair heterogeneous mean-field theory agree with simulation results. We analyze the critical scaling of the model as well. At last, epidemic outbreaks emerge for infective probabilities above the critical threshold.</div></div>","PeriodicalId":20152,"journal":{"name":"Physica A: Statistical Mechanics and its Applications","volume":"655 ","pages":"Article 130183"},"PeriodicalIF":2.8,"publicationDate":"2024-10-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142573078","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Social dilemmas, network reciprocity, and small-world property","authors":"F.B. Pereira ,&nbsp;R.S. Ferreira ,&nbsp;D.S.M. Alencar ,&nbsp;T.F.A. Alves ,&nbsp;G.A. Alves ,&nbsp;F.W.S. Lima ,&nbsp;A. Macedo-Filho","doi":"10.1016/j.physa.2024.130184","DOIUrl":"10.1016/j.physa.2024.130184","url":null,"abstract":"<div><div>We revisit two evolutionary game theory models, namely the Prisoner and the Snowdrift dilemmas, on top of small-world networks. These dynamics on networked populations (individuals occupying nodes of a graph) are mainly concerned with the competition between cooperating or defecting by allowing some process of revision of strategies. Cooperators avoid defectors by forming clusters in a process known as <em>network reciprocity</em>. This defense strategy is based on the fact that any individual interacts only with its nearest neighbors. The minimum cluster, in turn, is formed by a set of three completely connected nodes, and the bulk of these triplets is associated with the transitivity property of a network. We show that the transitivity increases eventually, assuming a constant behavior when observed as a function of the number of contacts an individual has. We investigate the influence of the network reciprocity on that transitivity-increasing regime on promoting cooperative behavior. The dynamics of small-world networks are compared with those of random regular and annealed networks, the latter typically studied as the well-mixed approach. The Snowdrift Game converges to an annealed scenario as randomness and coordination numbers increase. In contrast, the Prisoner’s Dilemma becomes more severe against the cooperative behavior under an increasing network reciprocity regime.</div></div>","PeriodicalId":20152,"journal":{"name":"Physica A: Statistical Mechanics and its Applications","volume":"655 ","pages":"Article 130184"},"PeriodicalIF":2.8,"publicationDate":"2024-10-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142573079","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Short-term freeway traffic speed multistep prediction using an iTransformer model","authors":"Yajie Zou ,&nbsp;Yubin Chen ,&nbsp;Yajiao Xu ,&nbsp;Hao Zhang ,&nbsp;Siyang Zhang","doi":"10.1016/j.physa.2024.130185","DOIUrl":"10.1016/j.physa.2024.130185","url":null,"abstract":"<div><div>Accurate prediction of the freeway traffic speed is important for enhancing intelligent transportation management and assisting with route planning. Current traffic speed prediction studies usually neglect predictions extending to an hour or longer. Thus, to address this gap, the inverted Transformer (iTransformer) model is utilized to predict freeway speeds across intervals from 5 to 150 minutes. The iTransformer model provides a global view by encapsulating the entire time series from each detector into variate tokens, allowing it to capture the complex patterns and dependencies that change over time. Additionally, a multi-head attention mechanism is employed to identify short-term and long-term speed patterns. This study validates the prediction performance of iTransformer by using the traffic speed data from an interstate freeway in Minnesota, comparing it against traditional traffic prediction methods and two other Transformer models. Results indicate that the iTransformer model outperforms these benchmark approaches, particularly when predicting speed over 60 minutes for peak hour periods.</div></div>","PeriodicalId":20152,"journal":{"name":"Physica A: Statistical Mechanics and its Applications","volume":"655 ","pages":"Article 130185"},"PeriodicalIF":2.8,"publicationDate":"2024-10-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142587419","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Depletion forces beyond the diluted limit","authors":"Néstor M. de los Santos-López ,&nbsp;Marco A. Ramírez-Guízar ,&nbsp;Gabriel Pérez-Ángel ,&nbsp;José M. Méndez-Alcaraz ,&nbsp;Ramón Castañeda-Priego","doi":"10.1016/j.physa.2024.130180","DOIUrl":"10.1016/j.physa.2024.130180","url":null,"abstract":"<div><div>The determination of the effective interactions in many-body systems still possesses a tremendous challenge in Condensed Matter Physics. The problem mainly resides in the fact that, on the one hand, there is not a unique route to obtain the effective forces between the ”observable” constituents and, on the other hand, one typically considers that the diluted limit of those components always corresponds to the effective forces at all particle concentrations. In the particular case of colloidal dispersions, it is very important to have experimental, theoretical, and computational tools that allow us to determine, accurately and without using significant approximations, the effective interactions between colloids. In this contribution, we report on a detailed study of depletion potentials in colloidal mixtures at finite concentration, namely, binary and ternary mixtures of disks (in two dimensions or 2D) and spheres (in three dimensions or 3D). To this end, the depletion forces between the large colloidal species are determined through a recently developed scheme based on the so-called contraction of the description, which has been extended and built at the level of the bare forces, i.e., we basically consider that all particles interact through the bare potentials and the net force acting on a given particle is determined by the second’s Newton law. This scheme can be easily adapted to Molecular Dynamics simulations. To verify the physical consistency of the formalism, we explicitly show that in the diluted limit of large particles, the resulting depletion potential reproduces correctly the AO-Vrij limit. As further proof of the accuracy of the results, a comparison of the structure of the large colloids in the whole mixture with the one that results using exclusively the depletion potential is carried out. In <span><math><mrow><mn>3</mn><mi>D</mi></mrow></math></span>, the results are explicitly compared with the potential of mean force and those obtained with the integral equations formalism. We also report a new colloidal stability mechanism based on the use of two different species of depletant agents at low and equal concentrations. Although we highlight the fact that the depletion potential depends on the concentration of the large species, we show that this dependence can be eliminated when the colloidal dispersion is open to a reservoir of small particles, i.e., when the chemical potential of small particles is fixed. Finally, we report the effects of polydispersity on the depletion interaction between large colloids.</div></div>","PeriodicalId":20152,"journal":{"name":"Physica A: Statistical Mechanics and its Applications","volume":"655 ","pages":"Article 130180"},"PeriodicalIF":2.8,"publicationDate":"2024-10-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142573081","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}