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The result converges with the physician’s own
judgment. For each pair (x,y) we can arrange new
actions of the fuzzy control algorithm to estimate the
patient’s period of surviving.
4 CONCLUSIONS
Fuzzy control system is a powerful method, which
mostly is applied to technologies controlling
complex processes by means of human experience.
In this work we have proved that the expected values
of patients’ survival lengths can be estimated even if
the mathematical formalization between independent
and dependent variables is unknown. For each x and
each y belonging to continuous spaces X and Y
respectively, we can repeat the control algorithm in
order to cover the space of pairs over the Cartesian
product of X and Y with a continuous surface.
We should emphasize that the Mamdani control
system does not need any special assumptions such
as distributions of variables, regularity and others,
which are necessary to be fulfilled in statistical
survival tests (see discussion in Section 1).
The authors’ special contribution is the
mathematically formalized design of membership
functions assisting variable levels.
ACKNOWLEDGEMENTS
The authors thank Blekinge Research Board for the
grant funding the accomplishment of the current
research.
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