Collective Dynamics (E-Journal)
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Interdependence of flows when merge in rail tunnel evacuations
Full text linkThe understanding of merging flows during evacuation can have important implications for rail tunnels safety. This paper explores the interdependence of the merging of flows coming from the walkway with those exiting the train. Eight train exit configurations were tested using a mock-up of a rail car exit and a lateral walkway involving 77 participants (mean age 48; standard deviation 15; range 18-74). New measurements and data processing methods are proposed allowing statistical analysis to be performed. The results provide quantitative evidence of the preferences between flows. We found that the bias in the evacuation was slightly in favour of the walkway when train exit was at 0 m in height. Contrary to expectations a moderate dominance of walkway flow was observed at 0.8 m in height. Less variation was found for the train exit at 1.2 m in height with a clear priority of walkway flow. This happened despite deference behaviours performed by participants, i.e. people stopped to help those entering from the rail car. This novel contribution aims to provide a new method for those involved in development and validation of new and current evacuation modelling tools and those who want to improve their understanding of merging behaviour during evacuation in rail tunnels
Towards Real-Time Monitoring of the Hajj
Full text linkAn automated approach to explore the fundamental properties of high-density pedestrian traffic is outlined. The framework operates on video or time lapse images captured from surveillance cameras. For pedestrian velocity extraction, the framework incorporates cross-correlation based Particle Image Velocimetry (PIV) techniques. For pedestrian density estimation, the framework relies on the Machine Learning technique of the Boosted Regression Trees. The information collected from images in pixel coordinates are transformed to world coordinates with a pin-hole camera based projective transformation technique. The framework has been tested with high density crowd images acquired during the Muslim religious event, the Hajj. Accuracy and performance of the framework are reported
A Markov-chain Activity-based Model for Pedestrians in Office Buildings
Full text linkAs the number of people working in office buildings increases, there is an urgent need to improve building services, such as lighting and temperature control, within these buildings to increase energy efficiency and well-being of occupants. A pedestrian behaviour model that simulates office occupants’ movements and locations can provide the high spatial and temporal resolution data required for the testing, evaluation, and optimization of these control systems. However, since most studies in pedestrian research focus on modelling specific actions at the operational level or target situations where movement schedules do not have to modelled, a pedestrian behaviour model that can simulate complex situations over long time periods is missing. Therefore, this paper proposes a tactical level model to generate occupant movement patterns in office buildings. The Markov-chain activity-based model proposed here is data parsimonious, flexible in accepting different levels of information, and can produce high resolution output. The mathematical properties of the methodology are analyzed to understand their impact on the final results. Finally, the tactical level pedestrian behaviour model is face validated using a case study of an imaginary office with a simple layout
Efficient Quantification of Model Uncertainties When De-boarding a Train
Full text linkIt is difficult to provide live simulation systems for decision support. Time is limited and uncertainty quantification requires many simulation runs. We combine a surrogate model with the stochastic collocation method to overcome time and storage restrictions and show a proof of concept for a de-boarding scenario of a train
Social Force Modeling of the Pedestrian Motion in the Mataf
Full text linkTwo models for the motion in the Mataf of the Holy Mosque of Makkah that are applicable to any so-called social force or agent-based model are presented. The first model assigns a desired distance to the Kaaba to each pilgrim. The second model assumes that pilgrims desire to get as close as possible to the Kaaba until a tolerable density is reached. Both models are realistic: image data shows behaviours of both types. The models are very simple to incorporate into any computational crowd dynamics code, and yield results that correlate surprisingly well with observed data
Field Theory in Practice
Full text linkThe aim of this paper is to present K. Lewin’s Field Theory in practice, applying it to evacuation simulations. The construction of the field is discussed from the scratch in order to define the psychological space of a social event. Then, we illustrate the interplay of the physical and the psychological aspects of a mathematical model of human behavior presenting and discussing evacuation simulations of one event. At first we simulate the physical situation and then we calculate an evacuation time applying an elementary microscopic model. An empirical plausibility control is presented. When we apply mathematical modeling or cybernetic methods to social sciences we are said to be careful. Nevertheless, a social event might be considered, on a natural way, as a set of time series, from the point of view of statistics. In this paper we restrict ourselves to introduce probabilities of random variables associated to the physical and the psychological space and define a measure for the evacuation simulation: The entropy of the event, merging the physical and the psychological spaces
A study of evacuation efficiency of a hopper-shape exit by using mice under high competition
Full text linkExit is the bottleneck of an evacuation from a room and the flow rate through an exit is believed to be depended on its width. A series of experiments were conducted in a bi-dimensional container where mice were driven to pass through two kinds of exit of the identical width, i.e., a conventional exit and a hopper-shape exit. The evacuation efficiency of the two exits was experimentally compared by using mice under competition. The results showed that a hopper-shape exit reduces the escape time by 25% compared with a conventional exit. Further study was conducted with the presence of a column in front of the two exits. The presence of a column in front of the conventional exit increases the escape time by 22.5%. On the contrary, the placement of column in front of the hopper-shape exit reduces the escape time by 48%. The study showed that the escape efficiency could be greatly improved by appropriately redesigning configuration of exit
Experimental study on the influence of background music on pedestrian movement in high densities
Full text linkIt is interesting to investigate the effect of background music on pedestrian movement. This paper investigates the properties of crowd motion with external rhythms. With rhythm, pedestrians stop more frequently than without any rhythm. The stopping also increases with the increment of the tempo. Velocity and flow with rhythms are lower than that without any rhythm at high densities due to the more frequent stopping. Stepping behavior analysis shows that the step frequency with rhythms is smaller than that without any rhythm, especially at high densities. Dynamic coordinated behavior is weakened by music, which also affectsthe stepping behavior. Our study will be helpful for understanding the effect of background music on pedestrian movement
Noise-Induced Stop-and-Go Dynamics in Pedestrian Single-file Motion
Full text linkStop-and-go waves are a common feature of vehicular traffic and have also been observed in pedestrian flows. Usually the occurrence of this self-organization phenomenon is related to an inertia mechanism. It requires fine-tuning of the parameters and is described by instability and phase transitions. Here, we present a novel explanation for stop-and-go waves in pedestrian dynamics based on stochastic effects. By introducing coloured noise in a stable microscopic inertia-free (i.e. first order) model, pedestrian stop-and-go behaviour can be described realistically without requirement of instability and phase transition. We compare simulation results to empirical pedestrian trajectories and discuss plausible values for the model’s parameters
Follower-Leader Concept in Microscopic Analysis of Pedestrian Movement in a Crowd
Full text linkThis paper presents a microscopic analysis of factors influencing pedestrian movement and interactions with their surroundings for two considered modes: independent movement influenced only by the surrounding conditions and synchronized movement based on following another pedestrian. This study analyses which of these effects prevail in different phases of the movement. The results show that the significant value of correlation between pedestrian velocity and corresponding individual density is observed mainly during approaching the crowd. Contrarily, in the segment of pedestrian trajectory which corresponds to movement inside the crowd, correlation between the velocity of a follower and a leader is more important. This confirms that the pedestrian behaviour in a crowd is a complex field