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Melbourne, Australia

Shiwakoti N.,Institute of Transport Studies | Sarvi M.,Institute of Transport Studies | Rose G.,Institute of Transport Studies | Burd M.,Monash University
Transportation Research Record | Year: 2010

An interesting aspect of collective dynamics of various biological entities is that they are emergent systems. A literature review examines how the fundamental principles of emergent systems can be applied to model collective pedestrian dynamics. A simulation model is then proposed on the basis of modifications of collective animal dynamics. Recent findings from experiments with panicking Argentine ants are presented to illustrate how such experiments can be used to study collective pedestrian traffic. Despite the difference in speed, size, and other biological details of the panicking individuals, the model proved capable of explaining the collective dynamics. The model's robustness is demonstrated by comparing its ability to simulate the collective traffic of panicking ants as well as collective human traffic. The lack of complementary data during emergency and panic situations is a challenge for model development. Empirical data from biological organisms can play a valuable role in the development of pedestrian traffic models from a theoretical perspective and in instances in which model validation is based on empirical data collected by video. Such a novel framework, which is based on complementary expertise, can be used as a basis for the design of solutions for the safe egress of pedestrians.

Shiwakoti N.,Institute of Transport Studies | Sarvi M.,Institute of Transport Studies | Rose G.,Institute of Transport Studies | Burd M.,Monash University
Transportation Research Record | Year: 2011

Collective egress comes into play during emergencies such as natural disasters or terrorist attacks, when rapid egress is essential for escape. An important aspect of collective egress under emergency conditions is the turning movement when a sudden change in the direction or the layout of the escape area occurs. Previous case studies of crowd disasters have highlighted the importance of such turning movements; however, both qualitative and quantitative studies seldom address this phenomenon specifically for emergency and panic situations. The paucity of complementary data on human panic presents a considerable challenge to undertaking quantitative analysis. The study described in this paper uses empirical data from real-life video footage of a crowd stampede and from panicking ants, paired with a simulation model, to demonstrate how potential problems and consequences of turning movements during collective dynamics can be studied. With this modeling tool, it may be possible to develop evacuation strategies and design solutions that can prevent stampedes and trampling, which occur when large groups of people try to escape from confined spaces where escape path directions abruptly change.

Shiwakoti N.,Institute of Transport Studies | Sarvi M.,Institute of Transport Studies | Burd M.,Monash University
Journal of Insect Behavior | Year: 2014

Crowd behaviors can have large fitness consequences for social organisms. Here we ask if there are similarities in the crowd dynamics of organisms that differ in body size, manner of locomotion, cognitive abilities, and state of alarm. Existing models of human crowd behavior have not been tested for their generality across species and body size nor across routine and emergency movements. We explore this issue by comparing the traffic dynamics of humans and of Argentine ants (Linepithema humile) to the predictions of our own model which was designed to simulate pedestrian movement. Some parameter values in the model were directly measured on ants but others were allometrically scaled from the human values to ant values based on the body mass difference. The model, with appropriately scaled parameters, correctly predicted two important properties of crowd behaviour for both organisms in a variety of circumstances: the flow rates and the distribution of time headways between successive ants in the escape sequence. The ability of a model of human pedestrian dynamics to predict behaviours of ant aggregations through allometric scaling of some parameter values suggests that there are fundamental features of crowd behavior that transcend the biological idiosyncrasies of the organisms involved. © 2013 Springer Science+Business Media New York.

Chun C.,Institute of Transport Studies | Xie S.,Institute of Transport Studies | Siqi W.,Institute of Transport Studies | Sze C.,Institute of Transport Studies | And 2 more authors.
Optical Engineering | Year: 2013

We introduce a generalized camera calibration model that is able to determine the camera parameters without requiring perfect rectangular road-lane markings, thus overcoming the limitations of state-of-the-art calibration models. The advantage of the new model is that it can cope in situations where road-lane markings do not form a perfect rectangle, making calibration by trapezoidal patterns or parallelograms possible. The model requires only four reference points-the lane width and the length of the left and right lane markings-to determine the camera parameters. Through real-world surveying experiments, the new model is shown to be effective in defining the 2D/3D transformation (or vice versa) when there is no rectangular pattern on the road, and can also cope with trapezoidal patterns, near-parallelograms, and imperfect rectangles. This development greatly increases the flexibility and generality of traditional camera calibration models. © 2013 Society of Photo-Optical Instrumentation Engineers (SPIE).

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