Page 222 - Data Science Algorithms in a Week

206 Abdulrahman Albar, Ahmad Elshennawy, Mohammed Basingab et al.

Defuzzification Process

After the fuzzifier converts numerical inputs into fuzzy values, and the fuzzy
inference engine is fed by the knowledge base to logically link the inputs to the output,
last step remaining in the fuzzy system occurs in the defuzzifier. Defuzzification is the
process where the fuzzy values are converted into crisp values. The defuzzifier is fed by
the database, and its importance lies in the fact that its crisp output is the desired product
of the entire system. Seven defuzzification methods are identified (Sivanandam, Sumathi,
& Deepa, 2007): centroid method, max-membership method, mean-max membership,
weighted average method, center of sums, first of maxima or last of maxima, and center
of largest area. This research adapts the centroid method for the defuzzification process,
and its formula is defined as following: = ∫( ) / ( ) .
∗

FUZZY SYSTEM PREPAREDNESS

In this section, the protocol was provided for eliciting expert knowledge to obtain
membership intervals, rule assessments and consensus rates, along with other data. Then,
a preparatory step must be taken to obtain results for the proposed model. In this step,
data will be prepared before it is added to the knowledge base, interval values will be
used to construct membership functions, and data from expert rule assessments will
contribute to the rule base.
Expert knowledge was sought from ten experts, designated with HCE expert codes.
The occupation and qualifications of these experts are described as follows:

 HCE-01: An experienced healthcare administrator in the Saudi public healthcare
sector
 HCE-02: A physician, professor, and consultant of emergency medicine in
several healthcare organizations in Saudi Arabia
 HCE-03: An academic researcher specializing in operations management
 HCE-04: An emergency room physician working in a Saudi private healthcare
sector
 HCE-05: An experienced emergency room nurse
 HCE-06: An academic researcher with experience in healthcare studies
 HCE-07: A researcher with vast experience in emergency room operations
management
 HCE-08: A physician from the ICU department who oversees emergency
department transfers to the ICU
 HCE-09: An emergency room physician
 HCE-10: A general physician who work closely with ED staff