43 research outputs found
Weighted lattice polynomials
We define the concept of weighted lattice polynomial functions as lattice
polynomial functions constructed from both variables and parameters. We provide
equivalent forms of these functions in an arbitrary bounded distributive
lattice. We also show that these functions include the class of discrete Sugeno
integrals and that they are characterized by a median based decomposition
formula.Comment: Revised version (minor changes
System reliability and weighted lattice polynomials
The lifetime of a system of connected units under some natural assumptions
can be represented as a random variable Y defined as a weighted lattice
polynomial of random lifetimes of its components. As such, the concept of a
random variable Y defined by a weighted lattice polynomial of (lattice-valued)
random variables is considered in general and in some special cases. The
central object of interest is the cumulative distribution function of Y. In
particular, numerous results are obtained for lattice polynomials and weighted
lattice polynomials in case of independent arguments and in general. For the
general case, the technique consists in considering the joint probability
generating function of "indicator" variables. A connection is studied between Y
and order statistics of the set of arguments.Comment: Revised version (minor changes
Weighted lattice polynomials of independent random variables
We give the cumulative distribution functions, the expected values, and the
moments of weighted lattice polynomials when regarded as real functions of
independent random variables. Since weighted lattice polynomial functions
include ordinary lattice polynomial functions and, particularly, order
statistics, our results encompass the corresponding formulas for these
particular functions. We also provide an application to the reliability
analysis of coherent systems.Comment: 14 page
Cumulative distribution functions and moments of weighted lattice polynomials
We give the cumulative distribution functions, the expected values, and the moments of weighted lattice polynomials when regarded as real functions. Since weighted lattice polynomial functions include Sugeno integrals, lattice polynomial functions, and order statistics, our results encompass the corresponding formulas for these particular functions
Reliability of systems with dependent components based on lattice polynomial description
Reliability of a system is considered where the components' random lifetimes
may be dependent. The structure of the system is described by an associated
"lattice polynomial" function. Based on that descriptor, general framework
formulas are developed and used to obtain direct results for the cases where a)
the lifetimes are "Bayes-dependent", that is, their interdependence is due to
external factors (in particular, where the factor is the "preliminary phase"
duration) and b) where the lifetimes' dependence is implied by upper or lower
bounds on lifetimes of components in some subsets of the system. (The bounds
may be imposed externally based, say, on the connections environment.) Several
special cases are investigated in detail
Characterizations of discrete Sugeno integrals as polynomial functions over distributive lattices
We give several characterizations of discrete Sugeno integrals over bounded
distributive lattices, as particular cases of lattice polynomial functions,
that is, functions which can be represented in the language of bounded lattices
using variables and constants. We also consider the subclass of term functions
as well as the classes of symmetric polynomial functions and weighted minimum
and maximum functions, and present their characterizations, accordingly.
Moreover, we discuss normal form representations of these functions
Associative polynomial functions over bounded distributive lattices
The associativity property, usually defined for binary functions, can be
generalized to functions of a given fixed arity n>=1 as well as to functions of
multiple arities. In this paper, we investigate these two generalizations in
the case of polynomial functions over bounded distributive lattices and present
explicit descriptions of the corresponding associative functions. We also show
that, in this case, both generalizations of associativity are essentially the
same.Comment: Final versio
Multivariate integration of functions depending explicitly on the minimum and the maximum of the variables
By using some basic calculus of multiple integration, we provide an
alternative expression of the integral in which the minimum and the maximum are replaced
with two single variables. We demonstrate the usefulness of that expression in
the computation of orness and andness average values of certain aggregation
functions. By generalizing our result to Riemann-Stieltjes integrals, we also
provide a method for the calculation of certain expected values and
distribution functions.Comment: 15 page