Schooling of the fish - Revision history

Jakub: /* Leadership */

2013-01-13T15:51:37Z

‎Leadership

Jakub: /* Resources */

2013-01-13T15:50:17Z

‎Resources

Jakub: /* Controls */

2013-01-13T15:47:34Z

‎Controls

Jakub: /* Conclusion */

2013-01-13T15:45:16Z

‎Conclusion

Jakub: /* Model and reality */

2013-01-13T15:43:25Z

‎Model and reality

Jakub: /* Model and reality */

2013-01-13T15:30:15Z

‎Model and reality

Jakub: /* Model and reality */

2013-01-13T15:29:49Z

‎Model and reality

Jakub: /* Model and reality */

2013-01-13T15:22:41Z

‎Model and reality

Jakub: /* World and Agents */

2013-01-13T15:08:27Z

‎World and Agents

Jakub at 15:01, 13 January 2013

2013-01-13T15:01:12Z

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 ** Based on world definition the world has no boundaries - so the fish continuously swim through the world without the need to avoid the edges which would become a considerable influence in regard to the hypothesis
 * Leader selection strategies
-** Due to one of the short comings mentioned in Model limitations there are only two leader selection strategies. Based on this restriction I imposed on the model, there are no leader selection strategies that would embed discussed property in themselves. (more on this constraint in later chapter)
+** Due to one of the short comings mentioned in Model limitations there are only two leader selection strategies. Based on this restriction I imposed on the model, there are no leader selection strategies that would embed discussed property in themselves.

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 =Resources=
 =Model source code=
 [[File:Schooling_of_the_fish.nlogo]]

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 Fish properties define agents basic physical capabilities - they restrict their movement, define their perceptual field and number of agents in the simulation.
-* fish-count slider - number of fish in population
+* fish-count slider - number of fish in population (0 - 50 fish)
-* cohorence-of-school slider - minimal distance from leader in the school
+* cohorence-of-school slider - minimal distance from leader in the school (0 - 5 patches)
-* visibility-angle slider - scope of the perceptual field
+* visibility-angle slider - scope of the perceptual field (30 - 70 degrees)
-* visibility-range slider - depth of the perceptual field
+* visibility-range slider - depth of the perceptual field (0 - 7 patches)
 === Leader selection ===

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 =Conclusion=
 This report presented an agent-based model of schooling behavior of the fish. The model is based on simulating the behavior of each fish independently. By common interactions between fish a school emerges and approximate the real concept of schools. The animation showing simulated schools built from this model seems to correspond to the observer's intuitive notion of what constitutes school-like motion. However it is really difficult to objectively measure how valid this model is, I do believe I managed to capture the essence of the schooling of the fish. By exposing the user to the controls of agent perception, leader selection and population control user is able to achieve many variations on schooling behavior.
 =Model source code=
 [[File:Schooling_of_the_fish.nlogo]]

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 Although shoaling fish can relate to each other in a loose way, with each fish swimming and foraging somewhat independently, they are nonetheless aware of the other members of the group as shown by the way they adjust behaviour such as swimming, so as to remains close to the other fish in the group. Shoaling groups can include fish of disparate sizes and can including mixed-species subgroups. If, as a further addition, the shoal becomes more tightly organised, with the fish synchronizing their swimming so they all move at the same speed and in the same direction, then the fish are said to be '''schooling'''. Schooling fish are usually of the same species and the same age/size. Fish schools move with the individual members precisely spaced from each other. The schools undertake complicated manoeuvres, as though the schools have minds of their own. Based on the definition above I truly feel the way that the model nicely approximates it since modeled fish are of the same sex and size and try to behave in described mannor.
-When it comes to the shape of the school however, the model does not always approximate any easily identifiable shape. Some fish in an attempt to defend themselves form a ball shaped school or others form a large blobs of fish with no identifiable shape. This is mainly based on leader selection strategies in combination with coherence of the school and it seams like proposed strategies do not always identify with better known shapes of the schools. Also I find it hard to bind the model with any particular kind of fish.
+When it comes to the shape of the school however, the model does not always approximate any easily identifiable shape. Some fish in an attempt to defend themselves form a ball shaped school or others form a large blobs of fish with no identifiable shape. This is mainly based on leader selection strategies in combination with coherence of the school and it seams like proposed strategies do not always identify with better known shapes of the schools. Also I find it hard to bind the model with any particular kind of fish. But since most of the hypotheses were drawn from an experts in the field of analyzing schooling behavior I am satisfied with the resulting performance of the model.
 =Conclusion=

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 =Model and reality=
-In this chapter I plan on assessing how my model fits the reality. Let me start by simple definition of schooling and how to approach it. For this purpose I will use wikipedia article defining schooling in following fashion. An '''aggregation''' of fish is the general term for any collection of fish that have gathered together in some locality. Fish aggregations can be structured or unstructured. An unstructured aggregation might be a group of mixed species and sizes that have gathered randomly near some local resource, such as food or nesting sites. If, in addition, the aggregation comes together in an interactive, social way, they are said to be '''shoaling'''. Although shoaling fish can relate to each other in a loose way, with each fish swimming and foraging somewhat independently, they are nonetheless aware of the other members of the group as shown by the way they adjust behaviour such as swimming, so as to remains close to the other fish in the group. Shoaling groups can include fish of disparate sizes and can including mixed-species subgroups. If, as a further addition, the shoal becomes more tightly organised, with the fish synchronizing their swimming so they all move at the same speed and in the same direction, then the fish are said to be '''schooling'''. Schooling fish are usually of the same species and the same age/size. Fish schools move with the individual members precisely spaced from each other. The schools undertake complicated manoeuvres, as though the schools have minds of their own. Based on the definition above I truly feel the way that the model nicely approximates it since modeled fish are of the same sex and size and try to behave in described mannor.
+In this chapter I plan on assessing how my model fits the reality. Let me start by simple definition of schooling and how to approach it. For this purpose I will use wikipedia article defining schooling in following fashion. An '''aggregation''' of fish is the general term for any collection of fish that have gathered together in some locality. Fish aggregations can be structured or unstructured. An unstructured aggregation might be a group of mixed species and sizes that have gathered randomly near some local resource, such as food or nesting sites. If, in addition, the aggregation comes together in an interactive, social way, they are said to be '''shoaling'''.
 When it comes to the shape of the school however, the model does not always approximate any easily identifiable shape. Some fish in an attempt to defend themselves form a ball shaped school or others form a large blobs of fish with no identifiable shape. This is mainly based on leader selection strategies in combination with coherence of the school and it seams like proposed strategies do not always identify with better known shapes of the schools. Also I find it hard to bind the model with any particular kind of fish.

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 Ranking function yields values from the interval <math><0; 1></math>. Fish can be categorized based on their rank as follows (in big enough population):
-* strong leader - rank higher than <math>0.3</math>
+* strong leader - rank higher than <math>0.4</math>
-* leader - rank from the interval <math>(0; 0.3)</math>
+* leader - rank from the interval <math>(0; 0.4)</math>
 * follower - rank equal to <math>0</math>
 * both leader and follower - cannot be determined based solely on ranking function

← Older revision		Revision as of 15:01, 13 January 2013
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		+	* '''Author:''' Jakub Stas, [mailto:xstaj68@vse.cz xstaj68]
		+	* '''Project name:''' Schooling of the fish
		+	* '''Class:''' 4IT495 Simulation of systems (WS 2012/2013)
		+	* '''Model type:''' Agent-based model
		+	*'''Software used:''' NetLogo
		+
	=Problem definition=		=Problem definition=
	The aggregate motion of a flock of birds, a herd of land animals, or a school of fish is a beautiful and familiar part of the natural world. A school exhibits many contrasts. It is made up of discrete fish yet overall motion seems fluid. It is simple in concept yet is so visually complex. This simulation proposes that the leaders can emerge as a consequence of a self-organized process based on local rules of dynamic interactions among individuals. Schools are an example of self-organized behaviour in a group where one can study the leadership properties of the individuals. Simulation proposed to monitor and analyze the leadership properties of the school and given individuals. Based on this analysis I tried to identify key factors that influence emergence of the leaders.		The aggregate motion of a flock of birds, a herd of land animals, or a school of fish is a beautiful and familiar part of the natural world. A school exhibits many contrasts. It is made up of discrete fish yet overall motion seems fluid. It is simple in concept yet is so visually complex. This simulation proposes that the leaders can emerge as a consequence of a self-organized process based on local rules of dynamic interactions among individuals. Schools are an example of self-organized behaviour in a group where one can study the leadership properties of the individuals. Simulation proposed to monitor and analyze the leadership properties of the school and given individuals. Based on this analysis I tried to identify key factors that influence emergence of the leaders.