Swarm Behaviour - People

People

A collection of people can also exhibit swarm behaviour, such as pedestrians or soldiers swarming the parapets. In Cologne, Germany, two biologists from the University of Leeds demonstrated flock like behaviour in humans. The group of people exhibited similar behavioural pattern to a flock, where if five percent of the flock changed direction the others would follow. If one person was designated as a predator and everyone else was to avoid him, the flock behaved very much like a school of fish. Understanding how humans interact in crowds is important if crowd management is to effectively avoid casualties at football grounds, music concerts and subway stations.

The mathematical modelling of flocking behaviour is a common technology, and has found uses in animation. Flocking simulations have been used in many films to generate crowds which move realistically. Tim Burton's Batman Returns was the first movie to make use of swarm technology for rendering, realistically depicting the movements of a group of bats using the boids system. The Lord of the Rings film trilogy made use of similar technology, known as massive, during battle scenes. Swarm technology is particularly attractive because it is cheap, robust, and simple.

An ant-based computer simulation using only six interaction rules has also been used to evaluate aircraft boarding behaviour.

Also, ants provided some guidance for Douglas A. Lawson, a systems analyst at Southwest Airlines.

Because we know that ants have accomplished these amazing things right based on very simple rules, we know that if we want to see something complicated happen—like completely filling the interior of an aircraft with people—we know that simple ant-type behavior is adequate to represent what's occurring," Lawson said. "So Southwest Airlines said, 'Help us figure out the most efficient way to help us get our passengers on a plane,' and you said, 'I know—I'll use ants'?" asked Salie. "Yeah, right. Because they do complicated things with very simple rules," Lawson said. Lawson used mathematically-modeled ants to determine the most efficient way of boarding a plane, which turns out to be open seating. "So Southwest's way of boarding without seat numbers is actually more efficient than when I board another airline and know exactly what my seat is?" asked Salie. "Right. When we simulated what the different airlines are doing, it turns out that with assigned seats, there's a one-third chance that you're going to ask two people to get up, whereas open seating—since the middle seat is the undesirable one—generally that's the one that's last to be filled, only one person is likely to get up, the person sitting near the aisle," said Lawson. "I may have to ask somebody to get up and get out of the way to let me get to a seat, and that's about it. So it's really simple. "So the ants are sort of an analogy—simple rules produce complicated transactions and events and major structures. and we can do the same thing in a little simulated world and represent very complicated processes," said Lawson.

Airlines have also used ant-based routing in assigning aircraft arrivals to airport gates. An airline system developed by Douglas A. Lawson uses swarm theory, or swarm intelligence—the idea that a colony of ants works better than one alone. Each pilot acts like an ant searching for the best airport gate. "The pilot learns from his experience what's the best for him, and it turns out that that's the best solution for the airline," Lawson explains. As a result, the "colony" of pilots always go to gates they can arrive and depart quickly. The program can even alert a pilot of plane back-ups before they happen. "We can anticipate that it's going to happen, so we'll have a gate available," says Lawson.

Swarm behaviour also occurs in traffic flow dynamics, such as the traffic wave. Bidirectional traffic can be observed in ant trails. In recent years this behaviour has been researched for insight into pedestrian and traffic models. Simulations based on pedestrian models have also been applied crowds which stampede because of panic.

Herd behaviour in marketing is used to explain the dependencies of customers' mutual behaviour. The Economist reported a recent conference in Rome on the subject of the simulation of adaptive human behaviour. It shared mechanisms to increase impulse buying and get people "to buy more by playing on the herd instinct." The basic idea is that people will buy more of products that are seen to be popular, and several feedback mechanisms to get product popularity information to consumers are mentioned, including smart card technology and the use of Radio Frequency Identification Tag technology. A "swarm-moves" model was introduced by a Florida Institute of Technology researcher, which is appealing to supermarkets because it can "increase sales without the need to give people discounts."

• Helbing D, Keltsch J, Molnar P (1997). "Modelling the evolution of human trail systems". Nature 388 (6637): 47–50. arXiv:cond-mat/9805158. Bibcode 1997Natur.388...47H. doi:10.1038/40353. PMID 9214501.
• Helbing D, Farkas I, Vicsek T (2000). "Simulating dynamical features of escape panic". Nature 407 (6803): 487–490. arXiv:cond-mat/0009448. Bibcode 2000Natur.407..487H. doi:10.1038/35035023. PMID 11028994.
• Helbing D, Farkas IJ, Vicsek T (2000). "Freezing by heating in a driven mesoscopic system". Physical review letters 84 (6): 1240–1243. arXiv:cond-mat/9904326. Bibcode 2000PhRvL..84.1240H. doi:10.1103/PhysRevLett.84.1240. PMID 11017488.