It uses GIS to calculate door-to-door travel times by public transport to a grid of points around the point of interest, resulting in a set of isochrone maps journey time contours within which the number of workplaces, households or residents can be calculated using census data.
22.
Isochrones are drawn on maps showing the dates of onset of a given phenomenon ( for example, the first frost and appearance or disappearance of the snow cover ) or the date of a particular value of a meteorological element in the course of a year ( for example, passing of the mean daily air temperature through zero ).
23.
Modelling stars as polytropes with index 3 / 2-- in other words, assuming they follow a pressure-density relationship of P = K \ rho ^ { 5 / 3 } he found that E = 45 is the maximum for a isochrones ( luminosity-temperature distributions of stars at a given age ) for a variety of stellar masses and noted that NGC2264, a very young star cluster, fits the isochrones well.
24.
Modelling stars as polytropes with index 3 / 2-- in other words, assuming they follow a pressure-density relationship of P = K \ rho ^ { 5 / 3 } he found that E = 45 is the maximum for a isochrones ( luminosity-temperature distributions of stars at a given age ) for a variety of stellar masses and noted that NGC2264, a very young star cluster, fits the isochrones well.
