Environmental Engineering Reference
In-Depth Information
The function q
i
=q
i
(xi) may be treated as a particular membership function
-
th criterion's view. The quality level (degree of preferability) of the 'j'-th object
is estimated by the value q
i
(j) = q
i
(x
i
(j)) of function q
i
(x
i
) from the point of
'i'-th criterion's view.
c) The process of normalization of specific quality
Normalization of specific criteria is done on the basis of the initial values
of indices. Sustainability indices are not suitable for the use because they have
different dimensions and interval of range ($/kWh, kg/kWh, kWh/$,...), so
they could not be compared.
d) Introducing the weight coefficient and choosing the vectors of weight
coefficients
The weight-coefficient w
i
(i= 1,.....m) shows which importance is given to
the particular criterion q
i
when the General Index Q(q;w) is formed. The
weight-coefficients 0>w
i
<1, for each i=1,.....m, is called the relative ''weight''
of specific criteria qi. Specific quality q
i
have more influence on the value of
General Index Q(q) at increasing of value of w
i
. Varying of coefficient w
i
, (
w
i
=1; w
i
=0), the influence of q
i
=q
i
(x
i
) on General Index Q(q;w) is changed,
respectively the importance which is given to specific quality q
i
is changed at
General Index forming.
General Index method comprise formation of an aggregative function with
the weightedarithmetic mean as the synthesizing function defined as
ik
Q
w q
(5)
i
1
where
w
i
- weight-coefficients elements of vector w
q
i
- indicators of specific criteria
Based on the presented procedure the Sustainability Index is defined as the
General Index in form of an aggregative function with weighted arithmetic
means as the synthesizing function.
