Journal articles: 'Crowd-structure interactions'

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Xia, Tong, Junjie Lin, Yong Li, Jie Feng, Pan Hui, Funing Sun, Diansheng Guo, and Depeng Jin. "3DGCN: 3-Dimensional Dynamic Graph Convolutional Network for Citywide Crowd Flow Prediction." ACM Transactions on Knowledge Discovery from Data 15, no. 6 (June 28, 2021): 1–21. http://dx.doi.org/10.1145/3451394.

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Crowd flow prediction is an essential task benefiting a wide range of applications for the transportation system and public safety. However, it is a challenging problem due to the complex spatio-temporal dependence and the complicated impact of urban structure on the crowd flow patterns. In this article, we propose a novel framework, 3- D imensional G raph C onvolution N etwork (3DGCN), to predict citywide crowd flow. We first model it as a dynamic spatio-temporal graph prediction problem, where each node represents a region with time-varying flows, and each edge represents the origin–destination (OD) flow between its corresponding regions. As such, OD flows among regions are treated as a proxy for the spatial interactions among regions. To tackle the complex spatio-temporal dependence, our proposed 3DGCN can model the correlation among graph spatial and temporal neighbors simultaneously. To learn and incorporate urban structures in crowd flow prediction, we design the GCN aggregator to be learned from both crowd flow prediction and region function inference at the same time. Extensive experiments with real-world datasets in two cities demonstrate that our model outperforms state-of-the-art baselines by 9.6%∼19.5% for the next-time-interval prediction.

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BELLOMO, N., D. KNOPOFF, and J. SOLER. "ON THE DIFFICULT INTERPLAY BETWEEN LIFE, "COMPLEXITY", AND MATHEMATICAL SCIENCES." Mathematical Models and Methods in Applied Sciences 23, no. 10 (July 12, 2013): 1861–913. http://dx.doi.org/10.1142/s021820251350053x.

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This paper presents a revisiting, with developments, of the so-called kinetic theory for active particles, with the main focus on the modeling of nonlinearly additive interactions. The approach is based on a suitable generalization of methods of kinetic theory, where interactions are depicted by stochastic games. The basic idea consists in looking for a general mathematical structure suitable to capture the main features of living, hence complex, systems. Hopefully, this structure is a candidate towards the challenging objective of designing a mathematical theory of living systems. These topics are treated in the first part of the paper, while the second one applies it to specific case studies, namely to the modeling of crowd dynamics and of the immune competition.

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Kim, HaeJung Maria, Kyung Wha Oh, and Hye Jung Jung. "Socialization on Sustainable Networks: The Case of eBay Green’s Facebook." Sustainability 12, no. 8 (April 24, 2020): 3476. http://dx.doi.org/10.3390/su12083476.

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Given that novel merchandising informatics is seen as a better approach to studying eco-friendly markets, this study aimed to explore consumer socialization of sustainable networks based on the theory of consumer socialization. By employing social network analysis using the NodeXL program, we examined the social class hierarchy, investigated the structure of social agent–learner relationships, and explored the social learning properties of the eBay Green Team Facebook network. The results indicated that the network has been structured as a ‘tight-crowd network’ through 76,482 interactions among 1612 actors from 19 clusters. Specifically, the centrality measure revealed the top influentials and their interactions with other eBay Green participants. The semantic analysis discerned the salient words, which implies that consumers gain utility from this network. We concluded that sustainable networks in social media can provide an account of the socialization of consumer attitudes and the role of top influentials in sustaining the relational network.

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Shahhoseini, Zahra, and Majid Sarvi. "Traffic Flow of Merging Pedestrian Crowds: How Architectural Design Affects Collective Movement Efficiency." Transportation Research Record: Journal of the Transportation Research Board 2672, no. 20 (September 18, 2018): 121–32. http://dx.doi.org/10.1177/0361198118796714.

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The need for developing reliable and rigorous models that can replicate and make predictions of pedestrian crowd evacuations has necessitated an understanding of the impact of architecture on individuals’ interactions with their surroundings and the behavioral rules that govern their movements. Due to the challenges of providing such behavioral data from natural evacuations and previous crowd incidents, simulation-based and laboratory-based evacuation experiments have recently been employed as innovative data-provision approaches to study crowd behavior notably under emergency conditions. This study explores pioneer experiments of emergency escape with a view to investigating the relationship between spatial constraints and collective behavior of human crowds. Here, we make use of two types of empirical and analytical data obtained from a large number of well-controlled laboratory and evacuation simulation experiments. This study presents findings corresponding to how and to what extent the presence of conflicting layouts in egress areas, particularly merging corridors, affect the collective motion of pedestrians. The focus of attention will be on measures of performance at macroscopic level derived from both observations. Our results suggested that the movement patterns observed in both types of experiments are sensitive to the angle between the two merging streams and the symmetry/asymmetry of the merging layouts, with symmetric layouts almost invariably outperforming the asymmetric counterparts. Also, within each symmetry/asymmetry structural type, the angle at which the flows combined with each other affected the efficiency of discharge. Our findings provide further evidence as to the significant role of the architectural structure of the movement area in facilitating the traffic flow of heavy crowds of pedestrians.

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HIRAO, Akihiro, TOMOKI IKENAGA, and YUKIKAZU YAMAGUCHI. "Examinations on the methodology for discussing issues of urban places by analyzing interactions between the crowd of visitors and spatial structure." Proceedings of The City Planning Institute of Japan, Kansai Branch 14 (2016): 145–48. http://dx.doi.org/10.11361/cpijkansai.14.0_145.

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Aleksandrov, Mitko, David J. Heslop, and Sisi Zlatanova. "3D Indoor Environment Abstraction for Crowd Simulations in Complex Buildings." Buildings 11, no. 10 (September 29, 2021): 445. http://dx.doi.org/10.3390/buildings11100445.

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This paper presents an approach for the automatic abstraction of built environments needed for pedestrian dynamics from any building configuration. The approach assesses the usability of navigation mesh to perform realistically pedestrian simulation considering the physical structure and pedestrian abilities for it. Several steps are examined including the creation of a navigation mesh, space subdivision, border extraction, height map identification, stairs classification and parametrisation, as well as pedestrian simulation. A social-force model is utilised to simulate the interactions between pedestrians and an environment. To perform quickly different 2D/3D geometrical queries various spatial indexing techniques are used, allowing fast identification of navigable spaces and proximity checks related to avoidance of people and obstacles in built environments. For example, for a moderate size building having eight floors and a net area of 13,000 m2, it takes only 104 s to extract the required building information to run a simulation. This approach can be used for any building configuration extracting automatically needed features to run pedestrian simulations. In this way, architects, urban planners, fire safety engineers, transport modellers and many other users without the need to manually interact with a building model can perform immediately crowd simulations.

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Kornberger, Martin. "The visible hand and the crowd: Analyzing organization design in distributed innovation systems." Strategic Organization 15, no. 2 (May 10, 2016): 174–93. http://dx.doi.org/10.1177/1476127016648499.

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The effectiveness and creativity of Linux, Wikipedia, and a plethora of other distributed innovation systems have attracted the attention of scholars, practitioners, and policy makers. The hallmark of these distributed innovation systems is that value creation transcends the boundaries of hierarchically organized firms. To date, only relatively few studies have focused on the organization design of distributed innovation systems. This conceptual article addresses this lacuna by asking, how does organization design structure relationships in distributed innovation systems, including interactions between the “visible hand” of the manager and the “crowd” of distributed innovation? The purpose of this article is to shift the unit of analysis of organization design from the individual firm to networks of actors providing a framework to study how design organizes distributed innovation systems. In order to do so, three design mechanisms (interface design, the design of participatory architectures, and the design of evaluative infrastructures) are proposed through which firms and other network actors organize their encounter in “the open” and through which they manage communication, coordination of tasks, and control in distributed innovation systems.

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Wang, Jing-hong, Siu-ming Lo, Jin-hua Sun, Qing-song Wang, and Hong-lin Mu. "Qualitative simulation of the panic spread in large-scale evacuation." SIMULATION 88, no. 12 (September 11, 2012): 1465–74. http://dx.doi.org/10.1177/0037549712456884.

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A small amount of literature has been produced on the study of panic spread in a large-scale emergency evacuation, especially that which involves rescue guidance. In a large-scale evacuation action, there are complicated interactions between people and the disaster environment, and it is very difficult to present such interactions in quantitative functions or specific values. In this paper, a qualitatively simulated approach to model and study the panic spread is proposed. First, the internal structure of the evacuation system is described and various internal and external phenomena related to the change of evacuees’ behaviors in the evacuation process are qualitatively interpreted. Based on the qualitative knowledge, a qualitative simulation model of a large-scale evacuation system is established. The calculation results of inverse group matrix verify the rationality and stability of our model. According to the implementation of a series of scenarios with different input, some uncertainty factors that can affect the panic spread in the evacuation process are analyzed, in which the spread of disaster, the rescue guidance, and the normal emotional evacuees are mainly considered. This model reproduces a well-known phenomenon in crowd evacuation, namely “fast is slow”, and confirms that the severity of disaster exponentially positively correlates with the panic spread, and the effectiveness of rescue guidance is influenced by the leading emotion in the crowds as a whole.

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Pécol, Philippe, Stefano Dal Pont, Silvano Erlicher, and Pierre Argoul. "Modelling crowd-structure interaction." Mécanique & Industries 11, no. 6 (November 2010): 495–504. http://dx.doi.org/10.1051/meca/2010057.

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Ye, Yuanjian, Renjie Zhang, Yiqing Zhao, Yuanyuan Yu, Wenxin Du, and Tinggui Chen. "A Novel Public Opinion Polarization Model Based on BA Network." Systems 10, no. 2 (April 9, 2022): 46. http://dx.doi.org/10.3390/systems10020046.

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At present, the polarization of online public opinion is becoming more frequent, and individuals actively participate in attitude interactions more and more frequently. Thus, online views have become the dominant force in current public opinion. However, the rapid fermentation of polarized public opinion makes it very easy for actual topic views to go to extremes. Significantly, negative information seriously affects the healthy development of the social opinion ecology. Therefore, it is beneficial to maintain national credibility, social peace, and stability by exploring the communication structure of online public opinions, analyzing the logical model of extreme public attitudes, and guiding the communication of public opinions in a timely and reasonable manner. Starting from the J–A model and BA network, this paper explores the specific attributes of individuals and opinion network nodes. By incorporating parameters such as individual conformity and the strength of individual online relationships, we established a model of online group attitude polarization, then conducted simulation experiments on the phenomenon of online opinion polarization. Through simulations, we found that individual conformity and the difference in environmental attitude greatly influence the direction of opinion polarization events. In addition, crowd mentality makes individuals spontaneously choose the side of a particular, extreme view, which makes it easier for polarization to form and reach its peak.

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Gao, Yan-an, and Qing-shan Yang. "A Theoretical Treatment of Crowd–Structure Interaction." International Journal of Structural Stability and Dynamics 18, no. 01 (January 2018): 1871001. http://dx.doi.org/10.1142/s0219455418710013.

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A vertical crowd–structure interaction model including the interaction amongst pedestrians is developed to study the structural performances of the supporting structure with social force effect. This model can be used to analyze the vibration problem of footbridge under a large crowd excitation. The social force is firstly introduced to describe the dynamic interaction amongst the bipedal models with damping-spring legs modeling pedestrian movement on a three-dimensional plate structure. The social force determines the walking direction and velocity of pedestrian. Numerical studies show that the structural dynamic performances can be remarkably changed under the crowd action. The natural frequency of structure is decreased and is time-varying with an increase in the crowd density. However, the damping ratio of structure is increased. The proposed model could well describe the crowd–structure dynamic interaction.

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Gao, Feng, Li Lin Cao, and Xing Hua Li. "Study on Human-structure Dynamic Interaction in Civil Engineering." E3S Web of Conferences 38 (2018): 03013. http://dx.doi.org/10.1051/e3sconf/20183803013.

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The research of human-structure dynamic interaction are reviewed. Firstly, the influence of the crowd load on structural dynamic characteristics is introduced and the advantages and disadvantages of different crowd load models are analyzed. Then, discussing the influence of structural vibration on the human-induced load, especially the influence of different stiffness structures on the crowd load. Finally, questions about human-structure interaction that require further study are presented.

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Alexander, N. A. "Theoretical treatment of crowd–structure interaction dynamics." Proceedings of the Institution of Civil Engineers - Structures and Buildings 159, no. 6 (December 2006): 329–38. http://dx.doi.org/10.1680/stbu.2006.159.6.329.

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Ploeger, A. "Psychological Care of Passengers During and After Hijacking." Journal of the World Association for Emergency and Disaster Medicine 1, no. 2 (1985): 201–3. http://dx.doi.org/10.1017/s1049023x00065596.

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This report refers to interviews with 53 of the passengers of the Lufthansa aircraft “Landshut,” liberated in 1977 in Mogadishu, Somalia and to information acquired during group-psychotherapy with 16 of these passengers. The psychological care during hijacking depends on the aim and situation of: a) the hijackers; b) the hostages; and c) the extorted.a) The hijackers are usually motivated by political aims. They feel that their crime is mitigated by their ideology. They are aware of the high risk of their undertaking and the violent counter-actions of the authorities, but they are highly motivated personally and socially. Hence, they are continually in a state of extreme expectant tension with most intensive perception and alert awareness. This activates the high intelligence they may have, but it is combined with a disturbance of their perception of reality. Usually there are several hijackers. Their communication with each other is characterized by a strong hierarchy structure, where the giving and acceptance of command is strictly defined. Their social situation is that of a “group”. The group interactions give them some relief of anxiety.b) Unlike the hijackers, the social situation of the hostages is that of a “crowd”. They have arrived at this situation by chance and usually without knowing each other personally. Since the formation of a group among the passengers would be an additional danger for the hijackers and would disturb their orientation and weaken their power, any verbal or non-verbal communication and any moving among the passengers is prohibited.

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Zeng, Dongjun, Haoqi Wang, and Jun Chen. "Dynamic Reliability Analysis of Large-Span Structures under Crowd Bouncing Excitation." Buildings 12, no. 3 (March 10, 2022): 332. http://dx.doi.org/10.3390/buildings12030332.

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Bouncing is one of the most common human crowd activities on civil infrastructures such as sports stadiums and concert halls, where the audience tends to make their bodies jump up and down to celebrate or participate in sport and musical events. Dynamic loads are thus generated and exerted on the structures, giving unpleasant structural vibration, which may affect the functionality of the structure or even lead to a panic of the crowd. Although researchers have studied human-induced vibration from many perspectives including load models, calculation methods, criteria for serviceability evaluation, etc., there has been minimal work regarding crowd-induced reliability analysis, mainly because the stochastic feature of the crowd load as well as the mechanism describing the crowd–structure interaction is still not clear. In this paper, a framework to calculate crowd-induced structural vibration that considers the crowd–structure interaction effect is proposed and is validated through an experimental test. The dynamic parameters of the bouncing person in the crowd are adopted from a previous statistical study. The feasibility of a probability density evolution method (PDEM) is proved to be effective to calculate structural stochastic vibration under the bouncing crowd. The dynamic reliability of the structure is thus analyzed based on the stochastic responses. Results show that the consideration of the crowd–structure interaction effect significantly affects the dynamic reliability, which is also dependent on various factors including bouncing frequency, failure criteria, limit threshold, human model parameter distribution, etc. This paper provides a foundation for the performance-based vibration serviceability design of large-span structures.

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Gao, Yan-An, Qing-Shan Yang, and Jing-Wei Qin. "Bipedal Crowd–Structure Interaction Including Social Force Effects." International Journal of Structural Stability and Dynamics 17, no. 07 (September 2017): 1750079. http://dx.doi.org/10.1142/s0219455417500791.

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This paper proposes a vertical crowd-structure interaction (CSI) model, considering the social force interaction effect among pedestrians. Pedestrian, as the basic unit of crowd, is modeled by a dynamic bipedal system with one lump mass and two compliance legs. The CSI model can be applied to self-determining the walking velocities of pedestrians instead of the sensitive passive control force for a stable gait from the original human–structure interaction (HSI) model. The damping compliance legs are responsible for the energy transfer between the pedestrian and the supporting structures during the dynamic walking process. Numerical studies with several pedestrians walking on a simply supported beam show an improvement of the damping property of the structure, but a decrease of the deterioration of natural frequency of the structure. The experiences gained in this study can be adopted for further study on the more complicated social force interaction among pedestrians in a large crowd passing some slender structures such as large-span footbridge.

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Alhadhira, Abdullah, Michael S. Molloy, Marcel Casasola, Ritu R. Sarin, Michael Massey, Amalia Voskanyan, and G. R. Ciottone. "Use of Dimensional Analysis in the X-, Y-, and Z-Axis to Predict Occurrence of Injury in Human Stampede." Disaster Medicine and Public Health Preparedness 14, no. 2 (July 5, 2019): 248–55. http://dx.doi.org/10.1017/dmp.2019.47.

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ABSTRACTBackground:Human stampedes (HS) may result in mass casualty incidents (MCI) that arise due to complex interactions between individuals, collective crowd, and space, which have yet to be described from a physics perspective. HS events were analyzed using basic physics principles to better understand the dynamic kinetic variables that give rise to HS.Methods:A literature review was performed of medical and nonmedical sourced databases, Library of Congress databases, and online sources for the term human stampedes resulting in 25,123 references. Filters were applied to exclude nonhuman events. Retrieved references were reviewed for a predefined list of physics terms. Data collection involved recording frequency of each phrase and physics principle to give the final proportions of each predefined principle used a single-entry method for each of the 105 event reports analyzed. Data analysis was performed using the R statistics packages “tidyverse”, “psych”, “lubridate”, and “Hmisc” with descriptive statistics used to describe the frequency of each observed variable.Results:Of the 105 reports of HS resulting in injury or death reviewed, the following frequency of terms were found: density change in a limited capacity, 45%; XY-axis motion failure, 100%; loss of proxemics, 100%; deceleration with average velocity of zero, 90%; Z-axis displacement pathology (falls), 92%; associated structure with nozzle effect, 93%; and matched fluid dynamic of high pressure stagnation of mass gathering, 100%.Conclusions:Description or reference to principles of physics was seen in differing frequency in 105 reports. These include XY-axis motion failure of deceleration that leads to loss of human to human proxemics, and high stagnation pressure resulting in the Z-axis displacement effect (falls) causing injury and death. Real-time video-analysis monitoring of high capacity events or those with known nozzle effects for loss of proxemics and Z-axis displacement pathology offers the opportunity to prevent mortality from human stampedes.

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Xiong, Jiecheng, Jun Chen, and Colin Caprani. "Spectral analysis of human-structure interaction during crowd jumping." Applied Mathematical Modelling 89 (January 2021): 610–26. http://dx.doi.org/10.1016/j.apm.2020.07.030.

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Ortiz, Albert Ricardo, Daniel Gómez, and Peter Thomson. "Characterising the human-structure interaction effect of the Olympic Stadium in Cali, Colombia." Ingeniería e Investigación 29, no. 1 (January 1, 2009): 13–23. http://dx.doi.org/10.15446/ing.investig.v29n1.15138.

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This paper presents the results of analysing the human-structure interaction effect of the Olympic Stadium in Cali, Colombia. Acceleration in the southern and western grandstands due to ambient vibration, free vibration and forced vibration tests were measured during football matches and musical performances. The data was processed using the power spectrum and time-frequency distribution, thus characterising the crowd motion for each of these events. A laboratory setup consisting of a rigid single stand was tested for characterising the jumping and damping effect of a person with regard to their posture. The loads obtained from such characterisation were incorporated into a finite element model of the southern and western grandstands to calculate the structures’ structural response. A coupling effect was observed between the loads caused by the crowd and the corresponding structural response. An increase of up to 200% in the damping of the human-structure system was observed when the structure was fully occupied by a crowd. Colombian national building code provisions for the dynamic loading of structures due to crowds are discussed.

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Gao, Yan-An, Qing-Shan Yang, and Yun Dong. "A Three-Dimensional Pedestrian–Structure Interaction Model for General Applications." International Journal of Structural Stability and Dynamics 18, no. 09 (September 2018): 1850107. http://dx.doi.org/10.1142/s0219455418501079.

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A three-dimensional (3D) pedestrian–structure interaction (PSI) system based on the biomechanical bipedal model is presented for general applications. The pedestrian is modeled by a bipedal mobile system with one lump mass and two compliant legs, which comprise damping and spring elements. The continuous gaits of the pedestrian are maintained by a self-driven walking kinetic energy, which is a new driven mechanism for the mobile unit. This self-driven mechanism enables the pedestrian to operate at a varying total energy level, as an important component for further modeling of the crowd-structure dynamic interaction. Numerical studies show that the pedestrian walking on the structure leads to a reduction in the natural frequency, but an increase in the damping ratio of the structure. This model can also reproduce the reaction forces between the feet and structure, similar to those measured in the field. In addition, the proposed model can well describe the 3D pedestrian–structure dynamic interaction. It is recommended for use in further study of more complicated scenarios such as the dynamic interaction between a large scale kinetic crowd and slender footbridge.

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Hu, Yue, Zhixiang Fang, Xinyan Zou, Haoyu Zhong, and Lubin Wang. "Two-Stage Tour Route Recommendation Approach by Integrating Crowd Dynamics Derived from Mobile Tracking Data." Applied Sciences 13, no. 1 (January 1, 2023): 596. http://dx.doi.org/10.3390/app13010596.

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Tourism activities essentially represent the interaction between crowds and attractions. Thus, crowd dynamics are critical to the quality of the tourism experience in personalized tour recommendations. In order to generate dynamic, personalized tour routes, this paper develops a tourist trip design problem with crowd dynamics (TTDP-CD), which is quantified with the crowd dynamics indicators derived from mobile tracking data in terms of crowd flow, crowd interaction, and crowd structure. TTDP-CD attempts to minimize the perceived crowding and maximize the assessed value of destinations while minimizing the total distance and proposes a two-stage route strategy of “global optimization first, local update later” to deal with the sudden increase in crowding in realistic scenarios. An evolutionary algorithm is extended with container-index coding, mixed mutation operators, and a global archive to create a personalized day tour route at the urban scale. To corroborate the performance of this approach, a case study was carried out in Dalian, China. The results demonstrate that the suggested method outperforms previous approaches, such as NSGA-II, MOPSO, MOACO, and WSM, in terms of performance and solution quality and decreases real-time crowding by an average of 7%.

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Yuan, Jian, Suhui Yu, Cong Liu, Chengqiang Gao, Wei Wang, Lin He, and Feng Fan. "Investigation of Dynamic Responses and Vibration Serviceability of Temporary Grandstands by a 3 DOF Interaction Model due to Swaying Motion." Shock and Vibration 2022 (January 6, 2022): 1–32. http://dx.doi.org/10.1155/2022/6217148.

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Excessive vibration of temporary grandstand by the crowd has lateral rhythmic motions, which attracted increasing attention in the recent years. This paper focuses on experiments where a temporary grandstand occupied by 20 participants is oscillated by a shaking table with a series of random waves and the crowd-induced rhythmic swaying motions at lateral direction, respectively. The dynamic forces that were induced by participants who have swayed at 0.5–1.8 Hz are recorded by a tri-axial human biomechanics force plate. A new relationship between the annoyance rate and structural acceleration at logarithmic coordinate is investigated and proposed, and the swaying load model is given. Based on these experimental results, a simplified three-degree-of-freedom lumped dynamic model of the joint human–structure system is reinterpreted. Afterwards, combined with a feasible range of crowd/structural dynamic parameters, a series of interaction models are analyzed, the vibration dose value (VDV) of the structure is obtained and discussed, and the notable parameters for interaction model are predicted. The experimental results show that the lateral serviceability limit is 1.29 m/s1.75 and the upper boundary is 2.32 m/s1.75. The dynamic response of model indicated that the VDV of structure will be decreased with increasing the mass of static crowd and damping ratio of the dynamic crowd. The max response of the model is α ≤ 0.6, f2 = 1.8 Hz or α > 0.6, f2 = 1.5 Hz or f1 = 2.5–3.5 Hz. It may be used as a reference value in vibration safety and serviceability assessment of TDGs, to estimate realistically the vibration response on the occasions when the crowds are swaying.

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Kratochvil, Ondrej, and Jiri Krizan. "Analysis of Footbridges under Human Induced Loads." Applied Mechanics and Materials 769 (June 2015): 180–84. http://dx.doi.org/10.4028/www.scientific.net/amm.769.180.

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The paper deals with a dynamic response of footbridge structure which is loaded by a movement of pedestrians. Interaction between crowd and footbridge structure is a complex problem. It is important to take into account load generated by the movement of pedestrians during the computation, but also change of load influenced by a response of the structure. It means practically that the response of the structure has influence on the movement of pedestrians. Computation of the response has to be performed in several steps. The first step is backward modification of load represented by the crowd movement. Next step is recalculation of the structure with newly compiled load. This approach can bring near the real behaviour of the structure which is exposed by the continuous movement of pedestrians..

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Wang, Yi He, and Na Yang. "Study on Dynamic Responses of Human-Structure Interaction System." Applied Mechanics and Materials 438-439 (October 2013): 775–78. http://dx.doi.org/10.4028/www.scientific.net/amm.438-439.775.

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t has previously been shown that human-structure dynamic system received much attention as a major topic in the serviceability performance and safety problems. In this study, the structure occupied by human are considered as a two degrees-of-freedom system. The dynamic characteristics of human-structure system are investigated by deriving the eigenvalue equation of the system. The response of structure to a person walking across it at various rates of walking is also researched. The results show that the pair natural frequencies of coupled system have a contrary trend when the crowd densities increase. It also demonstrates that the resonant situation occurs when structural fundamental frequency is equal to or an integer multiple of the pacing frequency.

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Yang, N., and Y. T. Jia. "Human-Induced Response and Reliability Analysis of Stochastic Dynamic System." Journal of Physics: Conference Series 2202, no. 1 (June 1, 2022): 012040. http://dx.doi.org/10.1088/1742-6596/2202/1/012040.

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Abstract This paper proposed a method analyzing crowd-induced stochastic vibration response by the dynamic reliability method. The efficiency of the probability density evolution method (PDEM) is improved by embedding the Kullback-Leibler (K-L) relative sensitivity analysis in response analysis of stochastic dynamic system. Then the complicated point selection technique of high dimension uncertain variables is avoided. The proposed method is illustrated by the response analysis of random crowd-structure interaction system where the load parameter randomness is considered. The acceleration induced by the crossing of crowd is predicted with the proposed method. Results obtained highlight the computation improvement in PDEM probabilistic response analysis in high dimension dynamic system. And the method could be used as an efficient way to predict and evaluate vibration serviceability of structures with human-induced vibration.

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Yuan, Jian, Lin He, Feng Fan, and Cong Liu. "THE DYNAMIC PARAMETERS OF PASSIVE HUMAN AT TEMPORARY DEMOUNTABLE GRANDSTANDS DURING EXPOSURE TO LATERAL VIBRATION." Journal of Civil Engineering and Management 24, no. 4 (June 29, 2018): 265–83. http://dx.doi.org/10.3846/jcem.2018.3073.

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Modelling the interaction between crowds and temporary demountable grandstands with identifying the human dynamic properties are challenges for structure optimal design. In this paper, for investigating and understanding the human and structural lateral dynamic features. A demountable grandstand was tested to obtain its model parameters firstly. Then it is tested at amplitudes between 0.16 m/s2 to 1.54 m/s2 with 75 random waves through a shaking table when occupied by twenty persons. Afterword a simplified two-degree of freedom lumped dynamic model of the joint human-structure system is reinterpreted. Utilizing the state-space model, the passive crowd dynamic parameters are obtained, based on root mean square accumulation error analysis. Statistical analysis of the predictive results concludes that seated crowd model damping ratio is 0.5, and the probable natural frequency is 2.0 Hz with the model mass ratio 0.7. For standing crowd model, the probable natural frequency is 1.5 Hz with the model mass damping ratio 0.4, and the model mass ratio is 0.7. It may have ability to serve as a reference value that can be utilized in vibration safety and serviceability assessment of TDGs, to estimate realistically the vibration response on the occasions when crowd are seated or standing.

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Venuti, Fiammetta, and Luca Bruno. "Crowd-structure interaction in lively footbridges under synchronous lateral excitation: A literature review." Physics of Life Reviews 6, no. 3 (September 2009): 176–206. http://dx.doi.org/10.1016/j.plrev.2009.07.001.

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Toso, Marcelo André, Herbert Martins Gomes, and José Luis Vital de Brito. "Crowd-structure interaction: Investigating the spatiality and synchronization of a pedestrian force model." Journal of Constructional Steel Research 133 (June 2017): 510–21. http://dx.doi.org/10.1016/j.jcsr.2017.03.007.

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Salyards, Kelly A., and Yue Hua. "Assessment of dynamic properties of a crowd model for human–structure interaction modeling." Engineering Structures 89 (April 2015): 103–10. http://dx.doi.org/10.1016/j.engstruct.2015.01.016.

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Yuan Yuan, Jianwu Fang, and Qi Wang. "Online Anomaly Detection in Crowd Scenes via Structure Analysis." IEEE Transactions on Cybernetics 45, no. 3 (March 2015): 548–61. http://dx.doi.org/10.1109/tcyb.2014.2330853.

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Wang, Haoqi, Zhuoran Zhang, and Jun Chen. "Prediction of structural responses induced by single-person jumping through a physical principle based on transfer functions." Advances in Structural Engineering 25, no. 1 (October 2, 2021): 146–57. http://dx.doi.org/10.1177/13694332211046343.

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The vibration caused by human excitation has become a key factor at the structural design stage of large-span structures including footbridges, sport stadia, and high-rise buildings. As the structures tend to become slenderer and lighter, the mass of the crowd is not negligibly small compared with the mass of the structure. In such cases, the crowd and the structure form a coupling system through a mechanism known as human–structure interaction (HSI). Researchers found that the structural responses with and without HSI are different. However, the interaction effect on the structural responses has rarely been quantitatively evaluated from the perspective of human system parameters. In this paper, a novel method using a physical principle to predict jumping-induced structural responses is proposed, in which the structural response is expressed as the multiplication of a series of transfer functions representing human system and structural dynamic properties. Structural responses of a large-span concrete structure under jumping excitation are predicted using the proposed method and identified human system parameters. Comparison with measured responses shows satisfactory agreement. The proposed method provides a solution to consider HSI effect on the calculation of structural responses in the vibration serviceability design for large-span structures.

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Jiménez-Alonso, Javier Fernando, Andres Sáez, Elsa Caetano, and Alvaro Cunha. "A crowd-structure interaction model to analyze the lateral lock-in phenomenon on footbridges." International Journal of Computational Methods and Experimental Measurements 6, no. 4 (November 3, 2017): 764–71. http://dx.doi.org/10.2495/cmem-v6-n4-764-771.

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Konstandina, Mamica Skenderi, and Geoffrey Gatharia Gachino. "International technology transfer: evidence on foreign direct investment in Albania." Journal of Economic Studies 47, no. 2 (April 5, 2020): 286–306. http://dx.doi.org/10.1108/jes-02-2018-0076.

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PurposeThe purpose of this paper is to examine the presumed role played by foreign direct investment (FDI) in transferring technology from home country into a host country. This paper uses data from Albanian manufacturing industry; first, to examine whether foreign presence results in technology transfer and, if yes, what type of technology is more prevalent and to what extent? Second, the paper attempts to investigate the purported determinants of technology transfer.Design/methodology/approachThe paper uses two main methodological approaches; first, the technology transfer was determined using an arithmetic index developed using simple arithmetic average. This index is determined using all the industries and taking six key components of technology into consideration. They included: products; production processes; technology and innovation; supplier and customers system; human resource management, training and reporting system; financial management, marketing and organizational structure. Second, assuming a limited dependent relationship between the variables and the technology transfer, a Tobit technique was proposed to examine the significant determinants of technology transfer. Technology transfer was proxied by the technology transfer index developed.FindingsThe results clearly demonstrate that FDI plays an important role in technology transfer and that notwithstanding the industrialization of Albania. As per the technology transfer index developed, product-related technology transfer ranked highest followed by the process-related technology. The Tobit results generated indicated that firm age, performance, absorptive capacity, labor mobility, innovation, demonstration effect and systematic support were all key determinants of technology transfer. Surprisingly, size of the firm did not seem to matter.Research limitations/implicationsThe results have possible managerial and policy ramifications. First, the government should continue to provide basic infrastructure. Second, the government needs to formulate policies focused on human capital accumulation. Third, policies should be focused on firm learning and innovation in order to build technological and absorptive capabilities. Moreover, there should be increased effort to facilitate and encourage R&D. Fourth, the government should coordinate and support the institutions especially those that play a crucial role in industrial investment promotion. Fifth, the government should encourage systemic interactions among different entities. Sixth, since high competition from foreign firms can crowd out domestic investment, strategic measures to regulate such competition should be enacted.Originality/valueThe novelty in this paper is the broad conceptualization of technology transfer to include not only the direct but also the indirect mode of technology transfer, which often takes place in the form of spillovers. The physical technology transfer, as well as, its actual impact in the economy is examined to ascertain that technology transfer indeed takes place. The analytical framework adopted overlaps international business, technology transfer and technological innovation literature strands to examine the holistic process of technology transfer.

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Bruno, Luca, and Fiammetta Venuti. "Crowd–structure interaction in footbridges: Modelling, application to a real case-study and sensitivity analyses." Journal of Sound and Vibration 323, no. 1-2 (June 2009): 475–93. http://dx.doi.org/10.1016/j.jsv.2008.12.015.

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Jiménez‐Alonso, Javier Fernando, Andrés Sáez, Elsa Caetano, and Álvaro Cunha. "Lateral crowd‐structure interaction model to analyse the change of the modal properties of footbridges." Structural Control and Health Monitoring 26, no. 6 (April 2019): e2356. http://dx.doi.org/10.1002/stc.2356.

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McRobie, Allan, Guido Morgenthal, Danny Abrams, and John Prendergast. "Parallels between wind and crowd loading of bridges." Philosophical Transactions of the Royal Society A: Mathematical, Physical and Engineering Sciences 371, no. 1993 (June 28, 2013): 20120430. http://dx.doi.org/10.1098/rsta.2012.0430.

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Parallels between the dynamic response of flexible bridges under the action of wind and under the forces induced by crowds allow each field to inform the other. Wind-induced behaviour has been traditionally classified into categories such as flutter, galloping, vortex-induced vibration and buffeting. However, computational advances such as the vortex particle method have led to a more general picture where effects may occur simultaneously and interact, such that the simple semantic demarcations break down. Similarly, the modelling of individual pedestrians has progressed the understanding of human–structure interaction, particularly for large-amplitude lateral oscillations under crowd loading. In this paper, guided by the interaction of flutter and vortex-induced vibration in wind engineering, a framework is presented, which allows various human–structure interaction effects to coexist and interact, thereby providing a possible synthesis of previously disparate experimental and theoretical results.

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Ouyang, Lijun, Caihong Wang, Bin Zhen, and Jian Xu. "Lateral Vibrations of a Cable-Stayed Bridge under Crowd Excitation." Mathematical Problems in Engineering 2015 (2015): 1–11. http://dx.doi.org/10.1155/2015/309645.

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A cable-stayed bridge model under crowd excitation is established in this paper by considering the geometric nonlinear property of the cables. Lateral vibrations of the model are investigated by employing the center manifold theory, and the first-order approximation solution of the periodic vibration of the bridge is derived by using the energy method. Numerical simulations are carried out to verify the validity of our analytical expressions. Our research shows that the existence of the cables can reduce the amplitude and frequency of the bridge, especially for the large amplitude case. This might explain why measured data of a cable-stayed bridge (T-bridge in Japan) vibrating under crowd excitation are much less than the theoretical results reported in previous studies in which the cable-stayed bridge is viewed as a single-degree-of-freedom system. Our analysis results suggest that the structure types of footbridges should not be easily ignored in the study of pedestrian-footbridge interaction.

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Li, Wenjun, Linsen Deng, Peng Liu, Yitao Fan, Jiaxin Wang, Xingli Sha, and Xianglin Kong. "A Monte Carlo simulation model of epidemic problem incorporating the interplaying between the crowd panic and infectious disease." Modern Physics Letters B 35, no. 23 (July 8, 2021): 2150394. http://dx.doi.org/10.1142/s0217984921503942.

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In this paper, based on a multi-layer network consisting of a social network and a physical contact network, we propose a microscopic Monte Carlo simulation model to reproduce the interaction and spread phenomena in the crowd from complex network perspective. The model mainly is used to reproduce the epidemic spread in the situation that the crowd becomes panic showing preventive control behaviors. This coupled microscopic simulation model considers variable infectious rate, recovery rate, panic heterogeneity and preventive measures suitable for studying different actual scenarios. Under the proposed framework, we can take quantitative analysis to measure the influences of various infectious rate, recovery rate, network structure and preventive measures on the spreading of diseases and panic. By comparing a large number of statistical results of the simulation experiments to study different scenarios, it is displayed that the established micro-simulation framework has certain advantages in scalability to consider more different actual scenarios and facilitating the researchers to grasp the global trend to learn what consequences the individual behavior will make.

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Yao, S., J. R. Wright, A. Pavic, and P. Reynolds. "Experimental study of human-induced dynamic forces due to bouncing on a perceptibly moving structure." Canadian Journal of Civil Engineering 31, no. 6 (December 1, 2004): 1109–18. http://dx.doi.org/10.1139/l04-081.

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This paper describes the first direct measurements of human-induced dynamic forces due to bouncing on a perceptibly moving force platform. A unique test rig, permitting a person to bounce physically on an idealized "single-degree-of-freedom system" with variable natural frequency and mass, is described and the test methodology explained. A set of representative results for different structure and bouncing frequencies is presented for one test subject. These results clearly demonstrate the effect that the flexibility of the structure has on the levels of force and dynamic response achieved. In particular, it was established that the applied force drops considerably when the subject bounces at a frequency fairly close to the natural frequency of the structure. However, it was found that it was physically not possible to bounce at or very close to the natural frequency for the configuration of the test rig chosen. Finally, the acceleration and displacement responses indicate that both the first and second harmonics of the bouncing force are capable of producing a near resonant response.Key words: crowd loading, flexible structure, dynamics, human-structure interaction, bouncing, jouncing, bobbing.

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Leisner, Scott M., and James E. Schoelz. "Joining the Crowd: Integrating Plant Virus Proteins into the Larger World of Pathogen Effectors." Annual Review of Phytopathology 56, no. 1 (August 25, 2018): 89–110. http://dx.doi.org/10.1146/annurev-phyto-080417-050151.

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The first bacterial and viral avirulence ( avr) genes were cloned in 1984. Although virus and bacterial avr genes were physically isolated in the same year, the questions associated with their characterization after discovery were very different, and these differences had a profound influence on the narrative of host-pathogen interactions for the past 30 years. Bacterial avr proteins were subsequently shown to suppress host defenses, leading to their reclassification as effectors, whereas research on viral avr proteins centered on their role in the viral infection cycle rather than their effect on host defenses. Recent studies that focus on the multifunctional nature of plant virus proteins have shown that some virus proteins are capable of suppression of the same host defenses as bacterial effectors. This is exemplified by the P6 protein of Cauliflower mosaic virus (CaMV), a multifunctional plant virus protein that facilitates several steps in the infection, including modulation of host defenses. This review highlights the modular structure and multifunctional nature of CaMV P6 and illustrates its similarities to other, well-established pathogen effectors.

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Gallegos-Calderón, Christian, Javier Naranjo-Pérez, Iván M. Díaz, and José M. Goicolea. "Identification of a Human-Structure Interaction Model on an Ultra-Lightweight FRP Footbridge." Applied Sciences 11, no. 14 (July 20, 2021): 6654. http://dx.doi.org/10.3390/app11146654.

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Due to the high strength-to-weight ratio of fibre reinforced polymers (FRPs), human-induced vibration problematic remains as a subject to be fully comprehended in order to extend the use of composites in Bridge Engineering. Thus, this paper studies an ultra-lightweight FRP footbridge, which presents excessive vertical vibrations when the fourth harmonic of a walking pedestrian is synchronised with the structure’s fundamental frequency. Focusing on the vertical bending mode, at 7.66 Hz, the bridge dynamic behaviour was assessed under the action of a single pedestrian crossing the facility at a step frequency of 1.9 Hz. As an over prediction of the footbridge response was computed using a moving force (MF) model available in a design guideline, a mass-spring-damper-actuator (MSDA) system was adopted to depict a walker. Hence, Human-Structure Interaction (HSI) phenomenon was considered. Employing the experimental results, parameters of the MSDA system were identified, leading to a HSI model that considers the first fourth harmonics of a walking human. Additionally, a parametric analysis was carried out, determining that the damping ratio of the human body and the load factor associated to the fourth harmonic are the most relevant parameters on the estimation of the response. The identified HSI model may be used as a first approximation to accurately predict the dynamic response of ultra-lightweight composite structures and should be extended to account for crowd-induced loads.

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Niu, Yunyun, Jieqiong Zhang, Yongpeng Zhang, and Jianhua Xiao. "Modeling Evacuation of High-Rise Buildings Based on Intelligence Decision P System." Sustainability 11, no. 17 (August 28, 2019): 4685. http://dx.doi.org/10.3390/su11174685.

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High-rise buildings usually have more complex architectural structures and hold more people than single-storey buildings. Currently, crowd management under emergent conditions, especially rapid evacuations of high-rise buildings, is a worldwide problem. In this study, a bio-inspired simulation technology extracted from a cell migration process, namely Intelligent Decision System (IDPS), was used to model the dynamic evacuation of high-rise buildings and calculate the evacuation time for different scenarios. This work was motivated by the comparability between the pedestrian movement behavior and cell migration process. Specific structure information of high architecture was also described in IDPS. A case study was done about evacuation simulation of a 12-storey teaching building in China University of Geosciences in Beijing. The simulation results showed that evacuation time varied with different parameters, such as density threshold, interaction probability, walking speed, population distribution, and stair width. With the proper density threshold and good interaction probability, the load balance of staircases and exits can be improved. For staircases with high utilization ratios, it was recommended that the evacuation process can be accelerated by widening the staircases appropriately. Finally, the impact of initial number of evacuees at each floor level was also analyzed in view of safety management.

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Nguyen, Tuan Dung, Georgiana Lyall, Alasdair Tran, Minjeong Shin, Nicholas George Carroll, Colin Klein, and Lexing Xie. "Mapping Topics in 100,000 Real-Life Moral Dilemmas." Proceedings of the International AAAI Conference on Web and Social Media 16 (May 31, 2022): 699–710. http://dx.doi.org/10.1609/icwsm.v16i1.19327.

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Moral dilemmas play an important role in theorizing both about ethical norms and moral psychology. Yet thought experiments borrowed from the philosophical literature often lack the nuances and complexity of real life. We leverage 100,000 threads—the largest collection to date—from Reddit’s r/AmItheAsshole to examine the features of everyday moral dilemmas. Combining topic modeling with evaluation from both expert and crowd-sourced workers, we discover 47 fine-grained, meaningful topics and group them into five meta-categories. We show that most dilemmas combine at least two topics, such as family and money. We also observe that the pattern of topic co-occurrence carries interesting information about the structure of everyday moral concerns: for example, the generation of moral dilemmas from nominally neutral topics, and interaction effects in which final verdicts do not line up with the moral concerns in the original stories in any simple way. Our analysis demonstrates the utility of a fine-grained data-driven approach to online moral dilemmas, and provides a valuable resource for researchers aiming to explore the intersection of practical and theoretical ethics.

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Everhart, Chad. "Valle Crucis Mobile Performance Stage: A Transformative Response to a Changing Landscape." Journal of Appalachian Studies 19, no. 1-2 (April 1, 2013): 108–23. http://dx.doi.org/10.2307/42635929.

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Abstract In general, buildings are comprised of numerous inactive elements and rooted to a site. With the exception of a few operable doors and windows, buildings are static. What if architecture were able to move and transform? Can a building serve multiple purposes and change appearances in an effort to adapt to its users and context? To address the vernacular architecture and fragile floodplains of the Valle Crucis community, students and faculty from Appalachian State’s Building Science Program designed and built a mobile, off-grid performance stage for Valle Crucis Community Park. Since the park’s former performance accommodations could no longer handle the large crowds at weekly events, a new performance stage was needed. Unfortunately, because most of the park was recently designated as a floodplain, permanent structures were not allowed unless constructed upwards of ten feet above the ground, causing acoustic, visual, and crowd interaction problems for a stage. Through extensive research and creative problem solving, a design solution was reached: build a transformable structure that serves multiple junctions and can be moved based upon user needs as well as flooding.

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Dai, Ruoxuan. "Analysis of Fan Culture and its Formation Mechanism in the Age of Mass Media." BCP Education & Psychology 7 (November 7, 2022): 138–44. http://dx.doi.org/10.54691/bcpep.v7i.2626.

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With the development of Internet media technology, fans are playing a more and more important role, and their behavior has an important impact on society, which is a social and cultural force that cannot be ignored. The development of film and television industry and the spread of IP dramas are inseparable from the promotion of fans. Fans' culture is constantly moving from the small crowd to the public, from being misunderstood to understanding. Today, fan culture has become a cultural phenomenon that can't be ignored, and the existence of fan groups has attracted more and more attention and discussion from all walks of life. The continuous development of new media technology and Internet technology has changed the power structure of the audience to obtain and disseminate information, and promoted the empowerment of groups on the basis of self-empowerment, thus promoting the empowerment of society and organizations. The formation of fan culture is also bound to be inseparable from the interaction between individual fans and culture. From emotion to identity to active participation, this series of interaction processes completed the evolution from individual to fan. On this basis, it further extends the process of how the fan culture, which was originally a minority culture, merged into popular culture. This paper also further reflects on whether fan culture is a form of "carnival".

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Van Hauwermeiren, Jeroen, Katrien Van Nimmen, Benedicte Vanwanseele, and Peter Van den Broeck. "Contact Force Reconstruction from the Lower-Back Accelerations during Walking on Vibrating Surfaces." Vibration 4, no. 1 (March 10, 2021): 205–31. http://dx.doi.org/10.3390/vibration4010015.

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Current models describing the effect of crowd-induced loading require a full-scale validation. To measure the lower-back accelerations during such validation, low-cost accelerometers are used to ensure a sufficient scalability. The goal is to verify to what extent the low-cost sensors can be used for the contact force reconstruction in case the pedestrian walks on a vibrating surface. First, a data set is collected comprising the simultaneous registration of the lower-back accelerations and the contact forces. Three contact force reconstruction methods are presented to accurately reconstruct the contact force in case of walking on a rigid surface. Second, the focus is on the contact force reconstruction in case of walking on a vibrating surface. A numerical study is performed adopting quantities of the Eeklo Benchmark Dataset providing a realistic framework. The additional lower-back accelerations as a result of the vibrating surface are estimated numerically. It is found that directly reconstructing the total contact force leads to inaccurate results. Instead, it is more suited to reconstruct the contact force one would induce on a rigid surface and combine this with an independent model to account for human–structure interaction. The conclusions of this numerical example are case-specific while the presented methodology is generic and can be readily extended to virtually any other structure.

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Zadorozhny, Vladimir, Patrick Manning, Daniel J. Bain, and Ruth Mostern. "Collaborative for Historical Information and Analysis: Vision and Work Plan." Journal of World-Historical Information 1, no. 1 (February 20, 2013): 1–14. http://dx.doi.org/10.5195/jwhi.2013.2.

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This article conveys the vision of a world-historical dataset, constructed in order to provide data on human social affairs at the global level over the past several centuries. The construction of this dataset will allow the routine application of tools developed for analyzing “Big Data” to global, historical analysis. The work is conducted by the Collaborative for Historical Information and Analysis (CHIA). This association of groups at universities and research institutes in the U.S. and Europe includes five groups funded by the National Science Foundation for work to construct infrastructure for collecting and archiving data on a global level. The article identifies the elements of infrastructure-building, shows how they are connected, and sets the project in the context of previous and current efforts to build large-scale historical datasets. The project is developing a crowd-sourcing application for ingesting and documenting data, a broad and flexible archive, and a “data hoover” process to locate and gather historical datasets for inclusion. In addition, the article identifies four types of data and analytical questions to be explored through this data resource, addressing development, governance, social structure, and the interaction of social and natural variables.

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Cuevas, Rocío G., Javier F. Jiménez-Alonso, Francisco Martínez, and Iván M. Díaz. "Assessment of the Lateral Vibration Serviceability Limit State of Slender Footbridges Including the Postlock-in Behaviour." Applied Sciences 10, no. 3 (February 2, 2020): 967. http://dx.doi.org/10.3390/app10030967.

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The lateral vibration serviceability of slender footbridges has been the subject of many studies over the last few decades. However, in spite of the large amount of research, a common criterion has not been set yet. Although the human–structure interaction phenomenon is widely accepted as the main cause of the sudden onset of high amplitudes of vibration, the current design recommendations do not include an expression for the auto-induced component of the pedestrian action and, as a consequence, it is not possible to evaluate the footbridge comfort once the lock-in effect has developed. Hence, the purpose of this paper is to propose a general formulation, which allows the analysis of the different load scenarios that the footbridge will experience during its overall life cycle. An important advantage over most current design guidelines is that the procedure permits the evaluation of the comfort level of the footbridge, even with crowd densities above the “critical number”, and thus takes informed decisions about the possible use of external devices to control the vibration response, depending on the probability of occurrence of the problem. The performance of the proposed method is successfully evaluated through numerical response simulations of two real footbridges, showing a good agreement with the experimental data.

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Bak-Coleman, Joseph B., Christopher K. Tokita, Dylan H. Morris, Daniel I. Rubenstein, and Iain D. Couzin. "Collective wisdom in polarized groups." Collective Intelligence 1, no. 1 (August 2022): 263391372211047. http://dx.doi.org/10.1177/26339137221104788.

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The potential for groups to outperform the cognitive capabilities of even highly skilled individuals, known as the “wisdom of the crowd”, is crucial to the functioning of democratic institutions. In recent years, increasing polarization has led to concern about its effects on the accuracy of electorates, juries, courts, and congress. While there is empirical evidence of collective wisdom in partisan crowds, a general theory has remained elusive. Central to the challenge is the difficulty of disentangling the effect of limited interaction between opposing groups (homophily) from their tendency to hold opposing viewpoints (partisanship). To overcome this challenge, we develop an agent-based model of collective wisdom parameterized by the experimentally-measured behaviour of participants across the political spectrum. In doing so, we reveal that differences across the political spectrum in how individuals express and respond to knowledge interact with the structure of the network to either promote or undermine wisdom. We verify these findings experimentally and construct a more general theoretical framework. Finally, we provide evidence that incidental, context-specific differences across the political spectrum likely determine the impact of polarization. Overall, our results show that whether polarized groups benefit from collective wisdom is generally predictable but highly context-specific.

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Macdonald, John H. G. "Lateral excitation of bridges by balancing pedestrians." Proceedings of the Royal Society A: Mathematical, Physical and Engineering Sciences 465, no. 2104 (December 16, 2008): 1055–73. http://dx.doi.org/10.1098/rspa.2008.0367.

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On its opening day, the London Millennium Bridge (LMB) experienced unexpected large amplitude lateral vibrations due to crowd loading. This form of pedestrian–structure interaction has since been identified on several other bridges of various structural forms. The mechanism has generally been attributed to ‘pedestrian synchronous lateral excitation’ or ‘pedestrian lock-in’. However, some of the more recent site measurements have shown a lack of evidence of pedestrian synchronization, at least at the onset of the behaviour. This paper considers a simple model of human balance from the biomechanics field—the inverted pendulum model—for which the most effective means of lateral stabilization is by the control of the position, rather than the timing, of foot placement. The same balance strategy as for normal walking on a stationary surface is applied to walking on a laterally oscillating bridge. As a result, without altering their pacing frequency, averaged over a large number of cycles, the pedestrian effectively acts as a negative (or positive) damper to the bridge motion, which may be at a different frequency. This is in agreement with the empirical model developed by Arup from the measurements on the LMB, leading to divergent amplitude vibrations above a critical number of pedestrians.

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Journal articles on the topic 'Crowd-structure interactions'

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