漁具研究へのシステム工学的アプローチ-I

トラップ・モデル

抄録

When a trap is set in the field where fish density is constant, let it be supposed that the number of fish and fish current in a trap at a time are x₁(t), x₂(t), the trap model is described as a second-order system.
For the first experiment, a thousand carp were prepared. The shape of trap is dual trap type (i. e., Fig. 1.).
When fish density is low, the trap model presents randomness, but in proportion to being higher, the trap model gets deterministic, and damping factor increases. The relation between ξ (damping ratio) and ρ (fish density ratio) was discussed by means of least square method and shown as follows;
ξ = 0.05 ρ^1.48
where ρ is the fish density ratio normalized with unit density (one fish per fish length square).