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Population dynamics is the type of mathematics used to model and study the size and age composition of populations as dynamical systems.Population dynamics is a branch of mathematical biology, and uses mathematical techniques such as differential equations to model behaviour.
A fishery population is affected by three dynamic rate functions: Birth rate or recruitment. Recruitment means reaching a certain size or reproductive stage. With fisheries, recruitment usually refers to the age a fish can be caught and counted in nets. Growth rate. This measures the growth of individuals in size and length.
In compressible fluid dynamics, impact pressure (dynamic pressure) is the difference between total pressure (also known as pitot pressure or stagnation pressure) and static pressure. [ 1 ] [ 2 ] In aerodynamics notation, this quantity is denoted as q c {\displaystyle q_{c}} or Q c {\displaystyle Q_{c}} .
For example, with an annual growth rate of 4.8% the doubling time is 14.78 years, and a doubling time of 10 years corresponds to a growth rate between 7% and 7.5% (actually about 7.18%). When applied to the constant growth in consumption of a resource, the total amount consumed in one doubling period equals the total amount consumed in all ...
I = (PAT) is the mathematical notation of a formula put forward to describe the impact of human activity on the environment. I = P × A × T The expression equates human impact on the environment to a function of three factors : population (P), affluence (A) and technology (T). [ 1 ]
When calculating or discussing relative growth rate, it is important to pay attention to the units of time being considered. [ 2 ] For example, if an initial population of S 0 bacteria doubles every twenty minutes, then at time interval t {\displaystyle t} it is given by solving the equation:
In econometrics, a dynamic factor (also known as a diffusion index) is a series which measures the co-movement of many time series. It is used in certain macroeconomic models. A diffusion index is intended to indicate the changes of the fraction of economic data time series which increase or decrease over the selected time interval,
Theoretically, it is easy to calculate ecological efficiency using the mathematical relationships above. It is often difficult, however, to obtain accurate measurements of the values involved in the calculation. Assessing ingestion, for example, requires knowledge of the gross amount of food consumed in an ecosystem as well as its caloric ...