Numerical modeling of chaotic behavior for small-scale movements of demersal fishes in coastal water |
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| Authors: | Yong-Hae KIM |
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| Institution: | Institute of Marine Industry, College of Marine Science, Gyeongsang National University, Tong-Young, Kyeognam 650-160, Korea, |
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| Abstract: | ABSTRACT: The presented model involves the application of chaos theory to generate fish movements resulting from environmental stimuli. The model uses three steps within a model neural network such as input stimuli, central decision making and response output resulting in fish movements. The stimuli in the first step include the main abiotic and biotic factors, which could be quantified as an intensity parameter that was then normalized as a ratio between 0 and 1. The decision-making process can be generated using chaos dynamics with the stimuli parameters. The response of fish movements from the output signal representing movement speed and direction of fish can be re-regulated as main movement pattern depending on physiological state or life cycle by third response filtering. The simulation results seen as a movement pattern for sea bream and flounder using this neural chaotic model fitted very well to the observations of fish tracked in the sea by ultrasonic tracking methods. It was also revealed that the fish movement components generated as movement velocity and direction when in tidal flow had similar patterns to those patterns seen in field observations with similar irregular and chaotic variations with time. |
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| Keywords: | chaotic decision making demersal fish movement model |
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