ABSTRACT

Chapter 3

Some concepts of

dependence and aging

3.1 Introduction

In this chapter we study some concepts of stochastic orderings, dependence and

aging properties for vectors of random quantities.

Such notions provide the essential tools for obtaining inequalities on condi-

tional probability distributions of residual lifetimes, namely for the conditional

probabilities of the type

PfT

h+1

> s

h+1

; :::; T

n

> s

n

jT

= t

; :::; T

h

= t

h

; T

h+1

> r

h+1

; :::; T

n

> r

n

g

(3.1)

considered in the previous chapter.