Global Journal of Pure and Applied Mathematics • ISSN 0973-1768 • Volume 12, Number 3 (2016)
© Research India Publications • http://www.ripublication.com/gjpam.htm
875
A New
α β
γ δ
-cuts in Trapezoidal Fuzzy Number and
its Approach in Decomposition Theorem
M. Clement Joe Anand
Assistant Professor (S.G.)
Department of Mathematics
Hindustan University, Chennai-603103
mclementj@hindustanuniv.ac.in
Janani Bharatraj
Ph.D. Research Scholar (Full-Time)
Department of Mathematics
Hindustan University, Chennai-603103
jananichari@gmail.com
Abstract— In this paper we are introducing a new cut called
the matrix cut in Trapezoidal Fuzzy Number based on α -cuts.
We have proposed the properties of the matrix cut and applied
the same in the Decomposition theorems.
Keywords—Fuzzy Number, Trapezoidal Fuzzy Number, α -
cuts, Decomposition theorem.
I. INTRODUCTION
The original formulation of the theory of fuzzy sets contains
the concept of a fuzzy number as a convex fuzzy subset of the
real line. It started gaining momentum with the publication of
seminal papers by A. Kaufmann, H. Dubois and D. Parade,
and others. Zadeh [13] introduced the concept of α -cut or
α -level set to bridge the concepts of fuzzy set theory and
traditional set theory. Let X be an universe and let F(X)
denote the set of all fuzzy sets of X. Let A F X and
[0,1] α . Then the crisp set / ()
A
A x X x
α
μ α is
called the α -cut or α -level set of A [8, 13]. Any fuzzy set
can be formed from a family of nested strong α -cut satisfying
the following equation. / ()
A
A x X x
α
μ α .
The decision making problems in the context of fuzzy sets can
be solved by transforming these sets into their families of
nested α -cuts. The solutions to each can be found using
traditional methods and then all the partial results are merged
to reconstruct a solution to the problem. The similarity
relations and fuzzy orderings have been discussed by Zadeh
using α -cut sets [13]. But the following question has to be
answered while introducing α -cuts. Is a single cut enough to
resolve a particular real-world problem? We now present a
real-world problem to stress on the importance of having two
or more cuts. Let us consider Bharat Stage emission
standards. In order to regulate the output of air-pollutants from
internal combustion engine equipment these emission
standards are instituted by the Government of India.
The emission standards for diesel truck and bus engines under
EuroIV are given below.
EuroIV
Test CO HC NOx PM
ESC 1.6 0.46 3.5 0.02
ETC 4.0 0.55 3.5 0.03
Here CO, HC, NOx and PM are considered as our proposed
α β
γ δ
-cuts for a trapezoidal fuzzy number.
II. PRELIMINARIES:
In this section the basic properties and decomposition
theorems for α -cuts have been presented.
A. Properties
Let , AB F X . Then the following properties holds for all
, [0,1] αβ .
i. ; A A
α α
ii. and A A A A
α β α β
α β
iii. ( ) A B A B
α α α
and
( ) A B A B
α α α
;
iv. ( ) A B A B
α α α
and
( ) A B A B
α α α
;
v.
(1 )
A A
α α
.
Figure 2.1 Trapezoidal Fuzzy Number with α -cut