Annals of the Institute of Statistical Mathematics

, Volume 34, Issue 1, pp 591–597

Storage capacity of a dam with gamma type inputs

  • A. M. Mathai

DOI: 10.1007/BF02481056

Cite this article as:
Mathai, A.M. Ann Inst Stat Math (1982) 34: 591. doi:10.1007/BF02481056


Consider mutually independent inputsX1,...,Xn onn different occasions into a dam or storage facility. The total input isY=X1+...+Xn. This sum is a basic quantity in many types of stochastic process problems. The distribution ofY and other aspects connected withY are studied by different authors when the inputs are independently and identically distributed exponential or gamma random variables. In this article explicit exact expressions for the density ofY are given whenX1,...,Xn are independent gamma distributed variables with different parameters. The exact density is written as a finite sum, in terms of zonal polynomials and in terms of confluent hypergeometric functions. Approximations whenn is large and asymptotic results are also given.

Key words and phrases

Random inputsstorage capacitydistribution of partial sumsexact densitiescomputable representationconfluent hypergeometric function of many variables

Copyright information

© Kluwer Academic Publishers 1982

Authors and Affiliations

  • A. M. Mathai
    • 1
  1. 1.McGill UniversityMontrealCanada