Combination Of Assumptions Research Articles

Spectral Band Absorptance for Atmospheric Slant Paths

A number of equations are derived for the absorptance along a slant path. The absorptances of slant and homogeneous paths are compared. Various combinations of assumptions are made in the derivation of these equations as to the variation of the temperature and absorber concentration along the path, the extent and nature of the overlapping of the spectral lines, the variation of the intensity and half-width from line to line, the shape of the spectral lines, and the extent of the frequency interval considered. The particular assumptions applicable to each result are clearly stated. A general method is developed for obtaining slant path absorptances from homogeneous path data when either the weak or strong line approximation is valid. A combination of the weak and strong line results gives new general expressions for the relationship of slant and homogeneous path absorptance. These results are correct in both of the weak and strong line limits and in addition provide a good approximation for all values of the parameters.

An Estimate of the Future Population of England and Wales

In 1944 the Royal Commission on Population was set up in order to determine the probable consequences of population trends then current. In order to do this they prepared a range of sixteen separate population projections for Great Britain based on various combinations of assumptions as to mortality, fertility (and marriage), and migration. The method used, in which each component of population change i.e. birth, death and migration receives separate treatment, is generally known as the component method. This distinguishes it from cruder methods based on the assumption that the total numbers in a population follow some mathematical formula.Since the Royal Commission reported, this method has continued to be used in preparing what may perhaps be described as the ‘official’ projections of the population of England and Wales.

Forecasts of the Population of the United States 1945–1975

Abstract : I transmit herewith a report on the future population of the United States. Forecasts of the population, by color, nativity, age, and sex, are presented, by 5 year time intervals, up to 1975, according to various combinations of assumptions as to the future trends of fertility and mortality. The present report is a revision of all earlier report, Estimates of Future Population of the United States, 1940-2000, which was prepared for the National Resources Planning Board by Warren S. Thompson and P. K. Whelpton of the Scripps Foundation for Research in Population Problems and published in August, 1943. The increasing interest in matters relating to population growth in the future led to an unexpected demand for this earlier report, which soon exhausted the supply. On May 18, 1945, the Census Committee on Demography recommended that the Bureau publish revised estimates of future population, utilizing not only the results of the 1940 census as did the previous report, but also current estimates of population embodying the changes of the war years.