Show relation of birth and death rate over time, creating the elements of the demographic transition. This one is for Ghana. You can clone this insight for other nations, just plug in the new crude birth and death rates and find the starting population in 1960.
Show relation of birth and death rate over time, creating the elements of the demographic transition. This one is for Ghana. You can clone this insight for other nations, just plug in the new crude birth and death rates and find the starting population in 1960.
Simulation of how tiger population and anti poaching efforts effect the black market value of tiger organs.
Simulation of how tiger population and anti poaching efforts effect the black market value of tiger organs.
Show relation of birth and death rate over time, creating the elements of the demographic transition. This one is for Australia. You can clone this insight for other nations, just plug in the new crude birth and death rates and find the starting population in 1960.
Show relation of birth and death rate over time, creating the elements of the demographic transition. This one is for Australia. You can clone this insight for other nations, just plug in the new crude birth and death rates and find the starting population in 1960.
Adapted from Hartmut Bossel's "System Zoo 3 Simulation Models, Economy, Society, Development."  ​Population model where the population is summarized in four age groups (children, parents, older people, old people). Used as a base population model for dealing with issues such as employment, care for
Adapted from Hartmut Bossel's "System Zoo 3 Simulation Models, Economy, Society, Development."

​Population model where the population is summarized in four age groups (children, parents, older people, old people). Used as a base population model for dealing with issues such as employment, care for the elderly, pensions dynamics, etc.
WIP Clone of IM-9085 for multiscale frameworks based on ecography  article . Vital Signs From NAP Toward Quality Measures for Population Health and the Leading Health Indicators  Report   WHO NCD Framework picture and IHI Whole system measures 2.0 (Added Nov 2016)
WIP Clone of IM-9085 for multiscale frameworks based on ecography article. Vital Signs From NAP Toward Quality Measures for Population Health and the Leading Health Indicators Report  WHO NCD Framework picture and IHI Whole system measures 2.0 (Added Nov 2016)
Show relation of birth and death rate over time, creating the elements of the demographic transition. This one is for Italy. You can clone this insight for other nations, just plug in the new crude birth and death rates and find the starting population in 1960.
Show relation of birth and death rate over time, creating the elements of the demographic transition. This one is for Italy. You can clone this insight for other nations, just plug in the new crude birth and death rates and find the starting population in 1960.
 ​Physical meaning of the equations  The Lotka–Volterra model makes a number of assumptions about the environment and evolution of the predator and prey populations:        1. The prey population finds ample food at all times.    2. The food supply of the predator population depends entirely on the
​Physical meaning of the equations
The Lotka–Volterra model makes a number of assumptions about the environment and evolution of the predator and prey populations:

1. The prey population finds ample food at all times.
2. The food supply of the predator population depends entirely on the size of the prey population.
3. The rate of change of population is proportional to its size.
4. During the process, the environment does not change in favour of one species and genetic adaptation is inconsequential.
5. Predators have limitless appetite.
As differential equations are used, the solution is deterministic and continuous. This, in turn, implies that the generations of both the predator and prey are continually overlapping.[23]

Prey
When multiplied out, the prey equation becomes
dx/dtαx - βxy
 The prey are assumed to have an unlimited food supply, and to reproduce exponentially unless subject to predation; this exponential growth is represented in the equation above by the term αx. The rate of predation upon the prey is assumed to be proportional to the rate at which the predators and the prey meet; this is represented above by βxy. If either x or y is zero then there can be no predation.

With these two terms the equation above can be interpreted as: the change in the prey's numbers is given by its own growth minus the rate at which it is preyed upon.

Predators

The predator equation becomes

dy/dt =  - 

In this equation, {\displaystyle \displaystyle \delta xy} represents the growth of the predator population. (Note the similarity to the predation rate; however, a different constant is used as the rate at which the predator population grows is not necessarily equal to the rate at which it consumes the prey). {\displaystyle \displaystyle \gamma y} represents the loss rate of the predators due to either natural death or emigration; it leads to an exponential decay in the absence of prey.

Hence the equation expresses the change in the predator population as growth fueled by the food supply, minus natural death.


This simulation examines the linkages between cultural, material, spatial demographic, and hierarchical dynamics.
This simulation examines the linkages between cultural, material, spatial demographic, and hierarchical dynamics.
Unconstrained exponential model to simulate population growth. There are three scenarios (Main, Big Population, High Growth) and four charts (Population, Growth, Population & Growth, Population vs Growth)
Unconstrained exponential model to simulate population growth. There are three scenarios (Main, Big Population, High Growth) and four charts (Population, Growth, Population & Growth, Population vs Growth)
Simulation of how tiger population and anti poaching efforts effect the black market value of tiger organs.
Simulation of how tiger population and anti poaching efforts effect the black market value of tiger organs.
This is a basic population estimator. Default values approximate recent data for the United States(North America).
This is a basic population estimator. Default values approximate recent data for the United States(North America).
 Exploring the conditions of permanent coexistence, rather than gradual disappearance of disadvantaged competitors. ​Z506 p32-35 System Zoo 3 by Hartmut Bossel.

Exploring the conditions of permanent coexistence, rather than gradual disappearance of disadvantaged competitors. ​Z506 p32-35 System Zoo 3 by Hartmut Bossel.

Adapted from Hartmut Bossel's "System Zoo 3 Simulation Models, Economy, Society, Development."  ​Population model where the population is summarized in four age groups (children, parents, older people, old people). Used as a base population model for dealing with issues such as employment, care for
Adapted from Hartmut Bossel's "System Zoo 3 Simulation Models, Economy, Society, Development."

​Population model where the population is summarized in four age groups (children, parents, older people, old people). Used as a base population model for dealing with issues such as employment, care for the elderly, pensions dynamics, etc.
Show prediction of birth and death rate over time, creating the elements of the demographic transition. This one is for Morocco.
Show prediction of birth and death rate over time, creating the elements of the demographic transition. This one is for Morocco.
    Dynamic simulation modelers are particularly interested in understanding and being able to distinguish between the behavior of stocks and flows that result from internal interactions and those that result from external forces acting on a system.  For some time modelers have been particularly int

Dynamic simulation modelers are particularly interested in understanding and being able to distinguish between the behavior of stocks and flows that result from internal interactions and those that result from external forces acting on a system.  For some time modelers have been particularly interested in internal interactions that result in stable oscillations in the absence of any external forces acting on a system.  The model in this last scenario was independently developed by Alfred Lotka (1924) and Vito Volterra (1926).  Lotka was interested in understanding internal dynamics that might explain oscillations in moth and butterfly populations and the parasitoids that attack them.  Volterra was interested in explaining an increase in coastal populations of predatory fish and a decrease in their prey that was observed during World War I when human fishing pressures on the predator species declined.  Both discovered that a relatively simple model is capable of producing the cyclical behaviors they observed.  Since that time, several researchers have been able to reproduce the modeling dynamics in simple experimental systems consisting of only predators and prey.  It is now generally recognized that the model world that Lotka and Volterra produced is too simple to explain the complexity of most and predator-prey dynamics in nature.  And yet, the model significantly advanced our understanding of the critical role of feedback in predator-prey interactions and in feeding relationships that result in community dynamics.The Lotka–Volterra model makes a number of assumptions about the environment and evolution of the predator and prey populations:

1. The prey population finds ample food at all times.
2. The food supply of the predator population depends entirely on the size of the prey population.
3. The rate of change of population is proportional to its size.
4. During the process, the environment does not change in favour of one species and genetic adaptation is inconsequential.
5. Predators have limitless appetite.
As differential equations are used, the solution is deterministic and continuous. This, in turn, implies that the generations of both the predator and prey are continually overlapping.[23]

Prey
When multiplied out, the prey equation becomes
dx/dtαx - βxy
 The prey are assumed to have an unlimited food supply, and to reproduce exponentially unless subject to predation; this exponential growth is represented in the equation above by the term αx. The rate of predation upon the prey is assumed to be proportional to the rate at which the predators and the prey meet; this is represented above by βxy. If either x or y is zero then there can be no predation.

With these two terms the equation above can be interpreted as: the change in the prey's numbers is given by its own growth minus the rate at which it is preyed upon.

Predators

The predator equation becomes

dy/dt =  - 

In this equation, {\displaystyle \displaystyle \delta xy} represents the growth of the predator population. (Note the similarity to the predation rate; however, a different constant is used as the rate at which the predator population grows is not necessarily equal to the rate at which it consumes the prey). {\displaystyle \displaystyle \gamma y} represents the loss rate of the predators due to either natural death or emigration; it leads to an exponential decay in the absence of prey.

Hence the equation expresses the change in the predator population as growth fueled by the food supply, minus natural death.


 Prey    dx / dt  =  αx  -  βxy   The prey reproduces exponentially ( αx ) unless subject to predation. The rate of predation is the chance  (  βxy)  with which the predators meet and kill the prey.   Predator    dy/dt =    δxy  -   γy   The predator population growth    δxy    depends on successful
Prey
dx/dtαx - βxy
The prey reproduces exponentially (αx) unless subject to predation. The rate of predation is the chance (βxy) with which the predators meet and kill the prey.

Predator

dy/dt = δxy - γy

The predator population growth δxy depends on successful kills and the reproduction rate; however, delta is likely be different from beta. The loss rate, an exponential decay, of the predators {\displaystyle \displaystyle \gamma y}γy represents either natural death or emigration

Simple one stock model of population increase
Simple one stock model of population increase