T<scp>HE</scp> F<scp>LOW OF</scp> H<scp>UMAN</scp> C<scp>ROWDS</scp>

Hughes, R.

doi:10.1146/annurev.fluid.35.101101.161136

Cited by 572 publications

(324 citation statements)

References 11 publications

Supporting

Mentioning

319

Contrasting

Unclassified

Order By: Relevance

“…In addition, we observed that large numbers of organisms can behave similarly to a fluid. This viewpoint has been used to model the flow in human crowds (37). Understanding ant rafts also requires an additional considerationnamely, that they are water repellent en masse.…”

Section: Discussionmentioning

confidence: 99%

Fire ants self-assemble into waterproof rafts to survive floods

Mlot

Tovey²,

Hu³

2011

Proc. Natl. Acad. Sci. U.S.A.

245

239

View full text Add to dashboard Cite

Why does a single fire ant Solenopsis invicta struggle in water, whereas a group can float effortlessly for days? We use time-lapse photography to investigate how fire ants S. invicta link their bodies together to build waterproof rafts. Although water repellency in nature has been previously viewed as a static material property of plant leaves and insect cuticles, we here demonstrate a selfassembled hydrophobic surface. We find that ants can considerably enhance their water repellency by linking their bodies together, a process analogous to the weaving of a waterproof fabric. We present a model for the rate of raft construction based on observations of ant trajectories atop the raft. Central to the construction process is the trapping of ants at the raft edge by their neighbors, suggesting that some "cooperative" behaviors may rely upon coercion.cooperative animal behavior | surface tension | adhesive | emergent | differential equation

show abstract

Section: Discussionmentioning

confidence: 99%

Fire ants self-assemble into waterproof rafts to survive floods

Mlot

Tovey²,

Hu³

2011

Proc. Natl. Acad. Sci. U.S.A.

245

239

View full text Add to dashboard Cite

show abstract

“…The interest comes from both its connections with open scientific challenges related to the development of complex behaviors and pattern formation in nonequilibrium systems [1], as well as from its relevance to the design and safety of infrastructures [2]. Connections with statistical physics [3] and fluid dynamics descriptions [4] have been used to develop models capable of reproducing some of the features observed in crowd phenomenology [5][6][7]. From a macroscopic point of view, it is no surprise that crowds may be described, at least qualitatively, by means of fluidlike continuity equations for the local crowd density [7].…”

Section: Introductionmentioning

confidence: 99%

Fluctuations around mean walking behaviors in diluted pedestrian flows

et al. 2017

View full text Add to dashboard Cite

Understanding and modeling the dynamics of pedestrian crowds can help with designing and increasing the safety of civil facilities. A key feature of crowds is its intrinsic stochasticity, appearing even under very diluted conditions, due to the variability in individual behaviours. Individual stochasticity becomes even more important under densely crowded conditions, since it can be nonlinearly magnified and may lead to potentially dangerous collective behaviours. To understand quantitatively crowd stochasticity, we study the real-life dynamics of a large ensemble of pedestrians walking undisturbed, and we perform a statistical analysis of the fully-resolved pedestrian trajectories obtained by a year-long high-resolution measurement campaign. Our measurements have been carried out in a corridor of the Eindhoven University of Technology via a combination of Microsoft Kinect TM 3D-range sensor and automatic headtracking algorithms. The temporal homogeneity of our large database of trajectories allows us to robustly define and separate average walking behaviours from fluctuations parallel and orthogonal with respect to the average walking path. Fluctuations include rare events when individuals suddenly change their minds and invert their walking direction. Such tendency to invert direction has been poorly studied so far even if it may have important implications on the functioning and safety of facilities. We propose a novel model for the dynamics of undisturbed pedestrians, based on stochastic differential equations, that provides a good agreement with our experimental observations, including the occurrence of rare events.

show abstract

“…Incorporating complex systems principles into the STEM curriculum is pedagogically promising for three major reasons: (1) the same complex systems principle frequently arises across superficially distant areas in different guises (e.g., positive feedback loops in microphone feedback and in the popularity of TV shows), (2) different instantiations of the same principle frequently behave very similarly [e.g., Navier-Stokes equations can be used to describe and predict wind flow patterns around an air foil, water in a damn, or crowds of people fleeing a burning building (Hughes, 2003)], and (3) complex systems principles are not obvious categories that students will usually learn on their own (e.g., positive feedback loops are not conspicuous). Students will learn the concepts of dogs, tables, and pencils on their own, but may not ever think about water flow in toilet tanks and thermoregulatory feathers on a bird as both being instantiations of negative feedback systems.…”

Section: Complex Systems Principles Are Important But Difficult To Lmentioning

confidence: 99%

Instruction in Computer Modeling Can Support Broad Application of Complex Systems Knowledge

Tullis

Goldstone

2017

Front. Educ.

View full text Add to dashboard Cite

Learners often struggle to grasp the important, central principles of complex systems, which describe how interactions between individual agents can produce complex, aggregate-level patterns. Learners have even more difficulty transferring their understanding of these principles across superficially dissimilar instantiations of the principles. Here, we provide evidence that teaching high school students an agent-based modeling language can enable students to apply complex system principles across superficially different domains. We measured student performance on a complex systems assessment before and after 1 week training in how to program models using NetLogo (Wilensky, 1999a). Instruction in NetLogo helped two classes of high school students apply complex systems principles to a broad array of phenomena not previously encountered. We argue that teaching an agent-based computational modeling language effectively combines the benefits of explicitly defining the abstract principles underlying agent-level interactions with the advantages of concretely grounding knowledge through interactions with agent-based models.

show abstract

THE FLOW OF HUMAN CROWDS

Cited by 572 publications

References 11 publications

Fire ants self-assemble into waterproof rafts to survive floods

Fire ants self-assemble into waterproof rafts to survive floods

Fluctuations around mean walking behaviors in diluted pedestrian flows

Instruction in Computer Modeling Can Support Broad Application of Complex Systems Knowledge

Contact Info

Product

Resources

About