Search results
Results from the WOW.Com Content Network
Population density (in agriculture: standing stock or plant density) is a measurement of population per unit land area. It is mostly applied to humans , but sometimes to other living organisms too. It is a key geographical term.
The half-life of a population is the time taken for the population to decline to half its size. We can calculate the half-life of a geometric population using the equation: N t = λ t N 0 by exploiting our knowledge of the fact that the population (N) is half its size (0.5N) after a half-life. [20]
Scrope's 1833 map of world population density, possibly the first dasymetric map. The earliest maps using this kind of approach include an 1833 map of world population density by George Julius Poulett Scrope [4] and an 1838 map of population density in Ireland by Henry Drury Harness, although the methods used to create these maps were never documented.
The density estimates are kernel density estimates using a Gaussian kernel. That is, a Gaussian density function is placed at each data point, and the sum of the density functions is computed over the range of the data. From the density of "glu" conditional on diabetes, we can obtain the probability of diabetes conditional on "glu" via Bayes ...
Population models are used to determine maximum harvest for agriculturists, to understand the dynamics of biological invasions, and for environmental conservation. Population models are also used to understand the spread of parasites, viruses, and disease. [2] Another way populations models are useful are when species become endangered.
The number density (symbol: n or ρ N) is an intensive quantity used to describe the degree of concentration of countable objects (particles, molecules, phonons, cells, galaxies, etc.) in physical space: three-dimensional volumetric number density, two-dimensional areal number density, or one-dimensional linear number density. Population ...
In probability theory and statistics, the beta distribution is a family of continuous probability distributions defined on the interval [0, 1] or (0, 1) in terms of two positive parameters, denoted by alpha (α) and beta (β), that appear as exponents of the variable and its complement to 1, respectively, and control the shape of the distribution.
A census choropleth map calculating population density using state boundaries will yield radically different results than a map that calculates density based on county boundaries. Furthermore, census district boundaries are also subject to change over time, [6] meaning the MAUP must be considered when comparing past data to current data.