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Fixed Quota versus Fixed Effort

Robert J. Scott
This model incorporates several options in examining fisheries dynamics and fisheries employment. The two most important aspects are the choice between I)managing based on setting fixed quota versus setting fixed effort , and ii) using the 'scientific advice' for quota setting  versus allowing 'political influence' on quota setting (the assumption here is that you have good estimates of recruitment and stock assessments that form the basis of 'scientific advice' and then 'political influnce' that desires increased quota beyond the scientific advice).

Fishery Management Population Sustainability

  • 10 months 1 week ago

Learning and Learn Level

Jo Fisch
Learning is one section of the of the holistic 4 L (Learning, Loving, Living and Life-work) Dimension. With the learning the cognitive-spiritual dimension is meant, by increase of the level, from beginner to legend. From ability over implementation to economic relevance is a need of consistent further developement for each individual person.From values there originates a vision and from a vision aims.SIMULATION is not finished

Holistic Learning Living Loving Life-work Growth Entrepreneurship Management

  • 5 years 6 months ago


Models the behaviour of a enterprise production and selling activities.
Under construction!!


  • 5 years 1 month ago

Clone of Story of nitrogen dynamics in a shallow lake

Duncan Golicher

This story presents a conceptual model of nitrogen cycling in a dune-lake system in the Northland region of New Zealand. It is based on the concept of a stock and flow diagram. Each orange ellipse represents an input, while each blue box represents a stock. Each arrow represents a flow. A flow involves a loss from the stock at which it starts and an addition to the stock at which it ends.

Environment Lake Nutrient Cycling Management Leaching

  • 1 year 4 months ago

Private Utility's Objective: Provision of a Public Good or Profit?

Hanns-Jürgen Hodann

Public utilities do not need to make a profit. They can concentrate on providing a quality service, a public good. By contrast, the primary objective of private utilities is not to provide a public good, but profit and profitability. This simple CLD tries to show the conflict that can arise from this and a hidden dynamic, a reinforcing feedback loop, that can lead to disaster. Unfortunately, there are examples where failure in infrastructure maintenance has led to disaster. On the 9th of July 2009, the German newspaper 'Welt Online' reported that the authorities in Berlin had to intervene and force the company that was running Berlin's S-Bahn (suburban rail service) to withdraw half of all the city's trains from service because they were considered unsafe! Something similar happened in the UK where failure to maintain rail tracks led to serious accidents. 

Economics Policy Management Services Transportation

  • 3 years 10 months ago