Page 273 - Practical Design Ships and Floating Structures

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is the comprehensive fizzy assessment index which means the membership degree ofjth element in the
selected set.

6) The method of dealing with assessment index b,
a. the maximum membership degree method
Taking the selected element VL corresponding to the maximum assessment index max bj as the results
of assessment, i.e.
I

b. the weighted-average method
Taking b, as weighting value, the a single selected element v, is operated with weighted-average
procedure, its results are:

n
If xb, = I or the normalizing procedure is completed, the formula is simplified as follows:
,=I
V=Cb,v, (16)
,=I
For non-digital nature factors (e.g. working capacity of staff), then the selected set will be:
V = {excellent, good, medium, poor) (17)
The selected element should be equivalent to digital factors while the weighted-average method is still
adopted.

2.2 Multi-Level Comprehensive Fuuy Assessment
1) In case of existing multi-factors
a. It is very difficult to distribute the weighting value on the basis of actual cases. Sometimes, the
weighting value mainly depends on the experience of the experts.
b. Non-meaningful assessment results (See Fig. 2).

2) Mathematical model
The above (right) gives an example of three level assessments

2.3 All Kinds of Mathematics Model for Comprehensive Fuq Assessment
m
1) Model one: M (n, v), bj = A rii) (j - 1,2, ..., n)
2) Model two: M( * , v ) , in which, " * " means a common multiplication, we have:
01
b, =z( wt, ) (j=I, 2, ..., n)
3) Model three: M(A,@ ) , in which, " (3 " means an operation of sum limited, i.e.
m m
w@y=min(l,x+y), inthemodel,b,=~(u,~r,, ) (j=1,2 ,..., n),thesymbolx isasumofm
I *I ,=I
m
numbers under c8 operation. Therefore, the above formula can be written as: b, = min{l,~(u, A r,, )}
,=I
(p1, ..., n)
2,