伝染病モデルの言葉を入れかえただけ。人口の40%は何度見ても買わないが、接触相手には含まれる点が要点。

オフィスビル・人口・住宅の3つを就業率と居住率でつなぐ。政策3（集合住宅の助成：住宅あたりの居住者数4→15）が最も効果的であることを確かめる。

位置と速度の2つのストックが互いを打ち返して振動になる。摩擦係数0で単振動、0より大きくすると減衰振動。

宿題用。角度と角速度がストック。sinが入るので振幅が大きいと周期が伸びる。

位置がストック、速度がフロー。d = v × ts の意味を確かめる。

Removed the volcanic Island influx and added an influx from CaCO3 dissolution.

A simple agent based foraging model. Consumer agents will move between fertile patches consuming them.

This model compares exponential growth vs logistic growth of a Quokka population. Quokka's are a small creature which are native to the Australian continent. This population increases due to addition of joey's that enter the initial quokka population through each quokka mother that gives birth. The loss of numbers is the quokka's leaving the population by death. This whole system keeps the quokka population in equilibrium and can also act as a guide to sustainability, as it allows us to view birth and death rates of a population. We can then work with the numbers of this model to decide how we want to approach this population with sustainability in mind. For example, a high birth rate means we would need to find methods to control the population to create a sustainable environment which is able to maintain this population. 

A very simple 

This model compares exponential growth vs logistic growth of a Quokka population. Quokka's are a small creature which are native to the Australian continent. This population increases due to addition of joey's that enter the initial quokka population through each quokka mother that gives birth. The loss of numbers is the quokka's leaving the population by death. This whole system keeps the quokka population in equilibrium and can also act as a guide to sustainability, as it allows us to view birth and death rates of a population. We can then work with the numbers of this model to decide how we want to approach this population with sustainability in mind. For example, a high birth rate means we would need to find methods to control the population to create a sustainable environment which is able to maintain this population. 

Page 39 in Limits to Growth (30y update)

Page 30 in Limits to Growth (30y update)