Accession Number : AD0667789

Title :   THE NEGATIVE EXPONENTIAL WITH CUMULATIVE ERROR.

Descriptive Note : Rept. for Jan-Aug 67,

Corporate Author : SCHOOL OF AEROSPACE MEDICINE BROOKS AFB TEX

Personal Author(s) : Danford,M. Bryan ; Hughes,Harry M.

Report Date : MAR 1968

Pagination or Media Count : 28

Abstract : In certain tracer experiments, a biologist may inject a tagged substance in an animal and, among other things, measure the fraction of material excreted in the urine each day. Assuming the true value to be a negative exponential in time, two error models (homoscedastic vs. proportional error) and two methods of analysis (incremental vs. cumulative) are compared. The general conclusion is that one should be fairly sure which model is appropriate and should have a reasonable notion of the size of the rate constant beta relative to the length of the experimental run before attempting to estimate beta from a logarithmic transformation of the periodic increments or of the cumulative amount remaining. (Author)

Descriptors :   (*BIOMETRY, MATHEMATICAL MODELS), (*TRACER STUDIES, REGRESSION ANALYSIS), LABELED SUBSTANCES, URINE, EXCRETION, STATISTICAL ANALYSIS, APPROXIMATION(MATHEMATICS), TRANSCENDENTAL FUNCTIONS, DECISION MAKING

Subject Categories : Anatomy and Physiology
      Radiation and Nuclear Chemistry

Distribution Statement : APPROVED FOR PUBLIC RELEASE