modelExponentialDecline
Exponential decline of connected stock
Extends from Interfaces.Basics.GenericSourceOrSink (SinkOrSource template with one flow port), Icons.Sink (General icon for sinks).
Information
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ExponentialDecline will drain the connected stock into a sink with infinite capacity at a rate that is determined at any time as the product of the current amount in the connected stock and the fractional rate given. The rate can either be given as a constant parameter fractionalRate or as a real input u, making it variable in time.
Notes
- By default it is assumed, that the rate given is a continously compounding rate (
isCCR = true). If this is not case, the rate will be converted using the →ForceOfInterest converter. - The effective rate of decline(e.g the product of the rate and amount in stock) must never be negative, as filling the connected stock is prohibited. Should the rate of outflow from the stock become negative, it will be set to zero.
- Exponential decline processes have a constant half-life (e.g., the time it takes to to shrink by 50%) which can be found by dividing log(2) ≈ 0.69 by the continuously compounding fractional rate (or by log(1+rate) if the rate is not a continuously compounding rate).
See also
Parameters
| Type | Name | Default | Description |
|---|---|---|---|
| Rate | fractionalRate | unspecified | Constant fractional rate to be used if chosen |
| Structural Parameters | |||
| Boolean | isCCR | true | = true, if the factional rate given is assumed to be a continuously compounding rate else the rate will be converted |
| Boolean | hasConstantRate | false | = true, if the constant fractional rate is used instead of the real input u |
Connectors
| Type | Name | Default | Description |
|---|---|---|---|
| Connectors.FlowPort | massPort (from GenericSourceOrSink) | Inflow to or outflow from connected stock | |
| Interfaces.Connectors.RealInput | u | Fractional rate given as exogenous input |
Components
| Type | Name | Default | Description |
|---|---|---|---|
| RealOutput | y (from ThreeSO_rate) | Rate information | |
| RealOutput | y1 (from ThreeSO_rate) | Rate information | |
| RealOutput | y2 (from ThreeSO_rate) | Rate information |
Revisions
- Value for parameter set to
unspecifiedin v2.1.0.