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Leyva SG, Pagonabarraga I. Clogging transition and anomalous transport in driven suspensions in a disordered medium. Phys Rev E 2024; 109:014618. [PMID: 38366435 DOI: 10.1103/physreve.109.014618] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2023] [Accepted: 01/05/2024] [Indexed: 02/18/2024]
Abstract
We study computationally the dynamics of forced, Brownian particles through a disordered system. As the concentration of mobile particles and/or fixed obstacles increase, we characterize the different regimes of flow and address how clogging develops. We show that clogging is preceded by a wide region of anomalous transport, characterized by a power law decay of intermittent bursts. We analyze the velocity distribution of the moving particles and show that this abnormal flow region is characterized by a coexistence between mobile and arrested particles, and their relative populations change smoothly as clogging is approached. The comparison of the regimes of anomalous transport and clogging with the corresponding scenarios of particles pushed through a single bottleneck show qualitatively the same trends highlighting the generality of the transport regimes leading to clogging.
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Affiliation(s)
- Sergi G Leyva
- Departament de Física de la Matèria Condensada, Universitat de Barcelona, Carrer de Martí i Franqués 1, 08028 Barcelona, Spain and Universitat de Barcelona Institute of Complex Systems (UBICS), Universitat de Barcelona, 08028 Barcelona, Spain
| | - Ignacio Pagonabarraga
- Departament de Física de la Matèria Condensada, Universitat de Barcelona, Carrer de Martí i Franqués 1, 08028 Barcelona, Spain and Universitat de Barcelona Institute of Complex Systems (UBICS), Universitat de Barcelona, 08028 Barcelona, Spain
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2
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HDRLM3D: A Deep Reinforcement Learning-Based Model with Human-like Perceptron and Policy for Crowd Evacuation in 3D Environments. ISPRS INTERNATIONAL JOURNAL OF GEO-INFORMATION 2022. [DOI: 10.3390/ijgi11040255] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/04/2022]
Abstract
At present, a common drawback of crowd simulation models is that they are mainly simulated in (abstract) 2D environments, which limits the simulation of crowd behaviors observed in real 3D environments. Therefore, we propose a deep reinforcement learning-based model with human-like perceptron and policy for crowd evacuation in 3D environments (HDRLM3D). In HDRLM3D, we propose a vision-like ray perceptron (VLRP) and combine it with a redesigned global (or local) perceptron (GOLP) to form a human-like perception model. We propose a double-branch feature extraction and decision network (DBFED-Net) as the policy, which can extract features and make behavioral decisions. Moreover, we validate our method’s ability to reproduce typical phenomena and behaviors through experiments in two different scenarios. In scenario I, we reproduce the bottleneck effect of crowds and verify the effectiveness and advantages of HDRLM3D by comparing it with real crowd experiments and classical methods in terms of density maps, fundamental diagrams, and evacuation times. In scenario II, we reproduce agents’ navigation and obstacle avoidance behaviors and demonstrate the advantages of HDRLM3D for crowd simulation in unknown 3D environments by comparing it with other deep reinforcement learning-based models in terms of trajectories and numbers of collisions.
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Viot P, Page G, Barré C, Talbot J. Weak clogging in constricted channel flow. Phys Rev E 2022; 105:014604. [PMID: 35193281 DOI: 10.1103/physreve.105.014604] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2021] [Accepted: 12/16/2021] [Indexed: 06/14/2023]
Abstract
We investigate simple models of a monodisperse system of soft, frictionless disks flowing through a two-dimensional microchannel in the presence of a single or a double constriction using Brownian dynamics simulation. After a transient time, a stationary state is observed with an increase in particle density before the constriction and a depletion after it. For a constriction width to particle diameter ratio of less than 3, the mean particle velocity is reduced compared to the unimpeded flow and it falls to zero for ratios of less than 1. At low temperatures, the particle mean velocity may vary nonmonotonically with the constriction width. The associated intermittent behavior is due to the formation of small arches of particles with a finite lifetime. The distribution of the interparticle exit times rises rapidly at short times followed by an exponential decay with a large characteristic time, while the cascade size distribution displays prominent peaks for specific cluster sizes. Although the dependence of the mean velocity on the separation of two constrictions is not simple, the mean flow velocity of a system with a single constriction provides an upper envelope for the system with two constrictions. We also examine the orientation of the leading pair of particles in front of the constriction(s). With a single constriction in the intermittent regime, there is a strong preference for the leading pair to be orientated perpendicular to the flow. When two constrictions are present, orientations parallel to the flow are much more likely at the second constriction.
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Affiliation(s)
- Pascal Viot
- Laboratoire de Physique Théorique de la Matière Condensée, Sorbonne Université, CNRS UMR 7600, 4, place Jussieu, 75005 Paris, France
| | - Gregory Page
- Laboratoire de Physique Théorique de la Matière Condensée, Sorbonne Université, CNRS UMR 7600, 4, place Jussieu, 75005 Paris, France
| | - Chloé Barré
- Laboratoire de Physique Théorique de la Matière Condensée, Sorbonne Université, CNRS UMR 7600, 4, place Jussieu, 75005 Paris, France
| | - Julian Talbot
- Laboratoire de Physique Théorique de la Matière Condensée, Sorbonne Université, CNRS UMR 7600, 4, place Jussieu, 75005 Paris, France
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A novel social distance model reveals the sidewall effect at bottlenecks. Sci Rep 2021; 11:20982. [PMID: 34697362 PMCID: PMC8546059 DOI: 10.1038/s41598-021-00486-1] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2021] [Accepted: 10/12/2021] [Indexed: 11/08/2022] Open
Abstract
Intermittent and periodic outbreaks of infectious diseases have had profound and lasting effects on societies throughout human history. During the global spread of SARS-CoV-2 and the resulting coronavirus disease (COVID-19), social distance has been imposed worldwide to limit the spread of the virus. An additional deliberate intention of keeping a minimum safety distance from neighbors can fundamentally alter the "social force" between individuals. Here, we introduce a new "social distance" term inspired by gas molecular dynamics and integrate it into an existing agent-based social force model to describe the dynamics of crowds under social-distanced conditions. The advantage of this "social distance" term over the simple increasing of the repulsive range of other alternatives is that the fundamental crowd properties are precisely described by our model parameters. We compare the new model with the Helbing and Molnar's classical model and experimental data, and show that this new model is superior in reproducing experimental data. We demonstrate the usability of this model with a bottleneck motion base case. The new model shows that the bottleneck effect can be significantly alleviated through small wall modifications. Lastly, we explain the mechanism of this improvement and conclude that this improvement is due to spatial asymmetry.
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Gao GJJ, Yang FL, Holcomb MC, Blawzdziewicz J. Enhanced flow rate by the concentration mechanism of Tetris particles when discharged from a hopper with an obstacle. Phys Rev E 2021; 103:062904. [PMID: 34271757 DOI: 10.1103/physreve.103.062904] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2020] [Accepted: 05/13/2021] [Indexed: 11/07/2022]
Abstract
We apply a holistic two-dimensional (2D) Tetris-like model, where particles move based on prescribed rules, to investigate the flow rate enhancement from a hopper. This phenomenon was originally reported in the literature as a feature of placing an obstacle at an optimal location near the exit of a hopper discharging athermal granular particles under gravity. We find that this phenomenon is limited to a system of sufficiently many particles. In addition to the waiting room effect, another mechanism able to explain and create the flow rate enhancement is the concentration mechanism of particles on their way to reaching the hopper exit after passing the obstacle. We elucidate the concentration mechanism by decomposing the flow rate into its constituent variables: the local area packing fraction ϕ_{l}^{E} and the averaged particle velocity v_{y}^{E} at the hopper exit. In comparison to the case without an obstacle, our results show that an optimally placed obstacle can create a net flow rate enhancement of relatively weakly driven particles, caused by the exit-bottleneck coupling if ϕ_{l}^{E}>ϕ_{o}^{c}, where ϕ_{o}^{c} is a characteristic area packing fraction marking a transition from fast to slow flow regimes of Tetris particles. Utilizing the concentration mechanism by artificially guiding particles into the central sparse space under the obstacle or narrowing the hopper exit angle under the obstacle, we can create a manmade flow rate peak of relatively strongly driven particles that initially exhibit no flow rate peak. Additionally, the enhanced flow rate can be maximized by an optimal obstacle shape, particle acceleration rate toward the hopper exit, or exit geometry of the hopper.
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Affiliation(s)
- Guo-Jie Jason Gao
- Department of Mathematical and Systems Engineering, Shizuoka University, Hamamatsu, Shizuoka 432-8561, Japan
| | - Fu-Ling Yang
- Department of Mechanical Engineering, National Taiwan University, Taipei 10617, Taiwan
| | - Michael C Holcomb
- Department of Physics and Geosciences, Angelo State University, San Angelo, Texas 76909-0904, USA
| | - Jerzy Blawzdziewicz
- Department of Physics and Astronomy, Texas Tech University, Lubbock, Texas 79409-1051, USA.,Department of Mechanical Engineering, Texas Tech University, Lubbock, Texas 79409-1021, USA
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Chen ZH, Wu ZX, Guan JY. Twofold effect of self-interest in pedestrian room evacuation. Phys Rev E 2021; 103:062305. [PMID: 34271713 DOI: 10.1103/physreve.103.062305] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2021] [Accepted: 05/27/2021] [Indexed: 11/07/2022]
Abstract
Evacuation dynamics of pedestrians in a square room with one exit is studied. The movement of the pedestrians is guided by the static floor field model. Whenever multiple pedestrians are trying to move to the same target position, a game theoretical framework is introduced to address the conflict. Depending on the payoff matrix, the game that the pedestrians are involved in may be either hawk-dove or prisoner's dilemma, from which the reaped payoffs determine the capacities, or probabilities, of the pedestrians occupying the preferred vacant sites. The pedestrians are allowed to adjust their strategies when competing with others, and a parameter κ is utilized to characterize the extent of their self-interest. It is found that self-interest may induce either positive or negative impacts on the evacuation dynamics depending on whether it can facilitate the formation of collective cooperation in the population or not. Particularly, a resonance-like performance of evacuation is realized in the regime of prisoner's dilemma. The effects of placing an obstacle in front of the exit and the diversity of responses of the pedestrians to the space competition on the evacuation dynamics are also discussed.
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Affiliation(s)
- Ze-Hao Chen
- Institute of Computational Physics and Complex Systems, Lanzhou University, Lanzhou, Gansu 730000, China
| | - Zhi-Xi Wu
- Institute of Computational Physics and Complex Systems, Lanzhou University, Lanzhou, Gansu 730000, China.,Lanzhou Center for Theoretical Physics and Key Laboratory of Theoretical Physics of Gansu Province, Lanzhou University, Lanzhou, Gansu 730000, China
| | - Jian-Yue Guan
- Institute of Computational Physics and Complex Systems, Lanzhou University, Lanzhou, Gansu 730000, China.,Lanzhou Center for Theoretical Physics and Key Laboratory of Theoretical Physics of Gansu Province, Lanzhou University, Lanzhou, Gansu 730000, China
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Deutsch A, Friedl P, Preziosi L, Theraulaz G. Multi-scale analysis and modelling of collective migration in biological systems. Philos Trans R Soc Lond B Biol Sci 2020; 375:20190377. [PMID: 32713301 PMCID: PMC7423374 DOI: 10.1098/rstb.2019.0377] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/11/2020] [Indexed: 02/06/2023] Open
Abstract
Collective migration has become a paradigm for emergent behaviour in systems of moving and interacting individual units resulting in coherent motion. In biology, these units are cells or organisms. Collective cell migration is important in embryonic development, where it underlies tissue and organ formation, as well as pathological processes, such as cancer invasion and metastasis. In animal groups, collective movements may enhance individuals' decisions and facilitate navigation through complex environments and access to food resources. Mathematical models can extract unifying principles behind the diverse manifestations of collective migration. In biology, with a few exceptions, collective migration typically occurs at a 'mesoscopic scale' where the number of units ranges from only a few dozen to a few thousands, in contrast to the large systems treated by statistical mechanics. Recent developments in multi-scale analysis have allowed linkage of mesoscopic to micro- and macroscopic scales, and for different biological systems. The articles in this theme issue on 'Multi-scale analysis and modelling of collective migration' compile a range of mathematical modelling ideas and multi-scale methods for the analysis of collective migration. These approaches (i) uncover new unifying organization principles of collective behaviour, (ii) shed light on the transition from single to collective migration, and (iii) allow us to define similarities and differences of collective behaviour in groups of cells and organisms. As a common theme, self-organized collective migration is the result of ecological and evolutionary constraints both at the cell and organismic levels. Thereby, the rules governing physiological collective behaviours also underlie pathological processes, albeit with different upstream inputs and consequences for the group. This article is part of the theme issue 'Multi-scale analysis and modelling of collective migration in biological systems'.
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Affiliation(s)
- Andreas Deutsch
- Department of Innovative Methods of Computing, Center for Information Services and High Performance Computing, Technische Universität Dresden, Dresden, Germany
| | - Peter Friedl
- Department of Cell Biology, Radboud Institute for Molecular Life Sciences, Radboud University Medical Centre, Nijmegen, The Netherlands
- Cancer Genomics Center, Utrecht, The Netherlands
- Department of Genitourinary Medicine, University of Texas MD Anderson Cancer Center, Houston, TX, USA
| | - Luigi Preziosi
- Department of Mathematical Sciences, Politecnico di Torino, Torino, Italy
| | - Guy Theraulaz
- Centre de Recherches sur la Cognition Animale, Centre de Biologie Intégrative, Université de Toulouse, CNRS, UPS, Toulouse, France
- Centre for Ecological Sciences, Indian Institute of Science, Bengaluru, India
- Institute for Advanced Study in Toulouse, Toulouse, France
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Echeverría-Huarte I, Zuriguel I, Hidalgo RC. Pedestrian evacuation simulation in the presence of an obstacle using self-propelled spherocylinders. Phys Rev E 2020; 102:012907. [PMID: 32795081 DOI: 10.1103/physreve.102.012907] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2020] [Accepted: 06/15/2020] [Indexed: 11/07/2022]
Abstract
We explore the role that the obstacle position plays in the evacuation time of agents when leaving a room. To this end, we simulate a system of nonsymmetric spherocylinders that have a prescribed desired velocity and angular orientation. In this way, we reproduce the nonmonotonous dependence of the pedestrian flow rate on the obstacle distance to the door. For short distances, the obstacle delays the evacuation because the exit size is effectively reduced; i.e., the distance between the obstacle and the wall is smaller than the door width. By increasing the obstacle distance to the door, clogging is reduced leading to an optimal obstacle position (maximum flow rate) in agreement with results reported in numerical simulations of pedestrian evacuations and granular flows. For further locations, however, a counterintuitive behavior occurs as the flow rate values fall again below the one corresponding to the case without obstacle. Analyzing the head-times distribution, we evidence that this new feature is not linked to the formation of clogs, but is caused by a reduction of the efficiency of the agent's instantaneous flow rate when the exit is not blocked.
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Affiliation(s)
- I Echeverría-Huarte
- Departamento de Física, Facultad de Ciencias, Universidad de Navarra, E-31080 Pamplona, Spain
| | - I Zuriguel
- Departamento de Física, Facultad de Ciencias, Universidad de Navarra, E-31080 Pamplona, Spain
| | - R C Hidalgo
- Departamento de Física, Facultad de Ciencias, Universidad de Navarra, E-31080 Pamplona, Spain
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Pattanayak S, Singh JP, Kumar M, Mishra S. Speed inhomogeneity accelerates information transfer in polar flock. Phys Rev E 2020; 101:052602. [PMID: 32575321 DOI: 10.1103/physreve.101.052602] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2020] [Accepted: 04/10/2020] [Indexed: 11/07/2022]
Abstract
A collection of self-propelled particles (SPPs) shows coherent motion and exhibits a true long-range-ordered state in two dimensions. Various studies show that the presence of spatial inhomogeneities can destroy the usual long-range ordering in the system. However, the effects of inhomogeneity due to the intrinsic properties of the particles are barely addressed. In this paper we consider a collection of polar SPPs moving at inhomogeneous speed (IS) on a two-dimensional substrate, which can arise due to varying physical strengths of the individual particles. To our surprise, the IS not only preserves the usual long-range ordering present in homogeneous speed models but also induces faster ordering in the system. Furthermore, the response of the flock to an external perturbation is also faster, compared to the Vicsek-like model systems, due to the frequent update of neighbors of each SPP in the presence of the IS. Therefore, our study shows that an IS can promote information transfer in a moving flock.
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Affiliation(s)
- Sudipta Pattanayak
- S. N. Bose National Centre for Basic Sciences, J D Block, Sector III, Salt Lake City, Kolkata 700106, India
| | - Jay Prakash Singh
- Department of Physics, Indian Institute of Technology (BHU), Varanasi 221005, India
| | - Manoranjan Kumar
- S. N. Bose National Centre for Basic Sciences, J D Block, Sector III, Salt Lake City, Kolkata 700106, India
| | - Shradha Mishra
- Department of Physics, Indian Institute of Technology (BHU), Varanasi 221005, India
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10
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Sun D, Lu H, Cao J, Wu Y, Guo X, Gong X. Flow mechanisms and solid flow rate prediction of powders discharged from hoppers with an insert. POWDER TECHNOL 2020. [DOI: 10.1016/j.powtec.2020.03.053] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
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Improvement in flow rate through an aperture on a conveyor belt: Effects of bottom wall and packing configurations. POWDER TECHNOL 2019. [DOI: 10.1016/j.powtec.2019.01.053] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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Kulkarni A, Thampi SP, Panchagnula MV. Sparse Game Changers Restore Collective Motion in Panicked Human Crowds. PHYSICAL REVIEW LETTERS 2019; 122:048002. [PMID: 30768343 DOI: 10.1103/physrevlett.122.048002] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/01/2017] [Revised: 11/04/2018] [Indexed: 06/09/2023]
Abstract
Using a dynamic variant of the Vicsek model, we show that the emergence of disorder from an orderly moving human crowd is a nonequilibrium first-order phase transition. We also show that this transition can be reversed by modifying the dynamics of a few agents, deemed as game changers. Surprisingly, the optimal placement of these game changers is found to be in regions of maximum local crowd speed. The presence of such game changers is effective owing to the discontinuous nature of the underlying phase transition. Thus our generic approach provides strategies to (i) delay crowd crush and (ii) design safe evacuation procedures, two aspects that are of paramount importance in maintaining safety of mass gatherings of people.
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Affiliation(s)
- Ajinkya Kulkarni
- Department of Applied Mechanics, Indian Institute of Technology Madras, Chennai 600036, India
| | - Sumesh P Thampi
- Department of Chemical Engineering, Indian Institute of Technology Madras, Chennai 600036, India
| | - Mahesh V Panchagnula
- Department of Applied Mechanics, Indian Institute of Technology Madras, Chennai 600036, India
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Vamsi Krishna Reddy A, Kumar S, Anki Reddy K, Talbot J. Granular silo flow of inelastic dumbbells: Clogging and its reduction. Phys Rev E 2018; 98:022904. [PMID: 30253544 DOI: 10.1103/physreve.98.022904] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2018] [Indexed: 06/08/2023]
Abstract
We study the discharge of inelastic, two-dimensional dumbbells through an orifice in the bottom wall of a silo using discrete element method (DEM) simulations. As with spherical particles, clogging may occur due to the formation of arches of particles around the orifice. The clogging probability decreases with increasing orifice width in both cases. For a given width, however, the clogging probability is much higher for the nonspherical particles due to their arbitrary orientations and the possibility of geometrical interlocking. We also examine the effect of placing a fixed, circular obstacle above the orifice. The clogging probability depends strongly on the vertical and lateral position of the obstacle, as well as its size. By suitably placing the obstacle the clogging probability can be significantly reduced compared to a system with no obstacle. We attempt to elucidate the clogging reduction mechanism by examining the packing fraction, granular temperature, and velocity distributions of the particles in the vicinity of the orifice.
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Affiliation(s)
- A Vamsi Krishna Reddy
- Department of Chemical Engineering, Indian Institute of Technology Guwahati, Guwahati 781039, India
| | - Sonu Kumar
- Department of Chemical Engineering, Indian Institute of Technology Guwahati, Guwahati 781039, India
| | - K Anki Reddy
- Department of Chemical Engineering, Indian Institute of Technology Guwahati, Guwahati 781039, India
| | - Julian Talbot
- Sorbonne Université, CNRS, Laboratoire de Physique Théorique de la Matière Condensée, LPTMC, F-75005 Paris, France
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Abstract
This paper investigates the effect of the form of an obstacle on the time that a crowd takes to evacuate a room, using a toy model. Pedestrians are modeled as active soft matter moving toward a point with intended velocities. An obstacle is placed in front of the exit, and it has one of four shapes: a cylindrical column, a triangular prism, a quadratic prism, or a diamond prism. Numerical results indicate that the evacuation-completion time depends on the shape of the obstacle. Obstacles with a circular cylinder (C.C.) shape yield the shortest evacuation-completion time in the proposed model.
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Affiliation(s)
- Ryosuke Yano
- Tokio, Marine and Nichido Risk Consulting Co. Ltd., 1-5-1 Otemachi, Chiyoda-ku, Tokyo, Japan
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15
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Shahhoseini Z, Sarvi M. Collective movements of pedestrians: How we can learn from simple experiments with non-human (ant) crowds. PLoS One 2017; 12:e0182913. [PMID: 28854221 PMCID: PMC5576663 DOI: 10.1371/journal.pone.0182913] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2017] [Accepted: 07/26/2017] [Indexed: 11/27/2022] Open
Abstract
Introduction Understanding collective behavior of moving organisms and how interactions between individuals govern their collective motion has triggered a growing number of studies. Similarities have been observed between the scale-free behavioral aspects of various systems (i.e. groups of fish, ants, and mammals). Investigation of such connections between the collective motion of non-human organisms and that of humans however, has been relatively scarce. The problem demands for particular attention in the context of emergency escape motion for which innovative experimentation with panicking ants has been recently employed as a relatively inexpensive and non-invasive approach. However, little empirical evidence has been provided as to the relevance and reliability of this approach as a model of human behaviour. Methods This study explores pioneer experiments of emergency escape to tackle this question and to connect two forms of experimental observations that investigate the collective movement at macroscopic level. A large number of experiments with human and panicking ants are conducted representing the escape behavior of these systems in crowded spaces. The experiments share similar architectural structures in which two streams of crowd flow merge with one another. Measures such as discharge flow rates and the probability distribution of passage headways are extracted and compared between the two systems. Findings Our findings displayed an unexpected degree of similarity between the collective patterns emerged from both observation types, particularly based on aggregate measures. Experiments with ants and humans commonly indicated how significantly the efficiency of motion and the rate of discharge depend on the architectural design of the movement environment. Practical applications Our findings contribute to the accumulation of evidence needed to identify the boarders of applicability of experimentation with crowds of non-human entities as models of human collective motion as well as the level of measurements (i.e. macroscopic or microscopic) and the type of contexts at which reliable inferences can be drawn. This particularly has implications in the context of experimenting evacuation behaviour for which recruiting human subjects may face ethical restrictions. The findings, at minimum, offer promise as to the potential benefit of piloting such experiments with non-human crowds, thereby forming better-informed hypotheses.
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Affiliation(s)
- Zahra Shahhoseini
- Centre for Disaster Management and Public Safety, School of Engineering, The University of Melbourne, Australia
- * E-mail:
| | - Majid Sarvi
- Centre for Disaster Management and Public Safety, School of Engineering, The University of Melbourne, Australia
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Zuriguel I, Janda Á, Arévalo R, Maza D, Garcimartín Á. Clogging and unclogging of many-particle systems passing through a bottleneck. EPJ WEB OF CONFERENCES 2017. [DOI: 10.1051/epjconf/201714001002] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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17
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Pastor JM, Garcimartín A, Gago PA, Peralta JP, Martín-Gómez C, Ferrer LM, Maza D, Parisi DR, Pugnaloni LA, Zuriguel I. Experimental proof of faster-is-slower in systems of frictional particles flowing through constrictions. PHYSICAL REVIEW. E, STATISTICAL, NONLINEAR, AND SOFT MATTER PHYSICS 2015. [PMID: 26764754 DOI: 10.1088/1367-2630/aaf4ca] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/16/2023]
Abstract
The "faster-is-slower" (FIS) effect was first predicted by computer simulations of the egress of pedestrians through a narrow exit [D. Helbing, I. J. Farkas, and T. Vicsek, Nature (London) 407, 487 (2000)]. FIS refers to the finding that, under certain conditions, an excess of the individuals' vigor in the attempt to exit causes a decrease in the flow rate. In general, this effect is identified by the appearance of a minimum when plotting the total evacuation time of a crowd as a function of the pedestrian desired velocity. Here, we experimentally show that the FIS effect indeed occurs in three different systems of discrete particles flowing through a constriction: (a) humans evacuating a room, (b) a herd of sheep entering a barn, and (c) grains flowing out a 2D hopper over a vibrated incline. This finding suggests that FIS is a universal phenomenon for active matter passing through a narrowing.
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Affiliation(s)
- José M Pastor
- Departamento de Física, Facultad de Ciencias, Universidad de Navarra, E-31080 Pamplona, Spain
| | - Angel Garcimartín
- Departamento de Física, Facultad de Ciencias, Universidad de Navarra, E-31080 Pamplona, Spain
| | - Paula A Gago
- Departamento de Ingeniería Mecánica, Facultad Regional La Plata, Universidad Tecnológica Nacional, Av. 60 Esq. 124 S/N, 1900 La Plata, Argentina
- Consejo Nacional de Investigaciones Científicas y Técnicas, Av. Rivadavia 1917 (1033), C. A. de Buenos Aires, Argentina
| | - Juan P Peralta
- Departamento de Ingeniería Mecánica, Facultad Regional La Plata, Universidad Tecnológica Nacional, Av. 60 Esq. 124 S/N, 1900 La Plata, Argentina
| | - César Martín-Gómez
- Departamento de Construcción, Instalaciones y Estructuras, Escuela Técnica Superior de Arquitectura, Universidad de Navarra, E-31080 Pamplona, Spain
| | - Luis M Ferrer
- Departamento de Patología Animal, Facultad de Veterinaria, Universidad de Zaragoza, Miguel Servet 177, 50013 Zaragoza, Spain
| | - Diego Maza
- Departamento de Física, Facultad de Ciencias, Universidad de Navarra, E-31080 Pamplona, Spain
| | - Daniel R Parisi
- Consejo Nacional de Investigaciones Científicas y Técnicas, Av. Rivadavia 1917 (1033), C. A. de Buenos Aires, Argentina
- Instituto Tecnológico de Buenos Aires, 25 de Mayo 444, (1002) C. A. de Buenos Aires, Argentina
| | - Luis A Pugnaloni
- Departamento de Ingeniería Mecánica, Facultad Regional La Plata, Universidad Tecnológica Nacional, Av. 60 Esq. 124 S/N, 1900 La Plata, Argentina
- Consejo Nacional de Investigaciones Científicas y Técnicas, Av. Rivadavia 1917 (1033), C. A. de Buenos Aires, Argentina
| | - Iker Zuriguel
- Departamento de Física, Facultad de Ciencias, Universidad de Navarra, E-31080 Pamplona, Spain
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