Research Article

Rule Extraction for Screening of COVID-19 Disease Using Granular Computing Approach

Algorithm 1

Granular network construction algorithm [30].
Result: a granule network
initialization;
(1) Construct the clan of basic concept with respect to atomic formulas
BC (U) = {(a = v, m (a = v))| a∈F, v ∈Va}.
(2) Set the unused basic concepts to the set of basic concepts
UBC (U) = BC (U).
(3) Set the granule network to GN = ({U}, ∅), which is a graph consists of only one node and no arc
(4) While the set of smallest granules in GN is not a covering solution of the classification problem do the following
  (4.1) compute the fitness of each unused basic concept.
  (4.2) Select the basic concept C = (a = v, m (a = v)) with maximum value of fitness.
  (4.3) Set UBC (U) = UBC (U) − {C}.
  (4.4) Modify the granule network GN by adding new nodes which are the intersection of m (a = v) and the original nodes of GN; connect the new nodes by arcs labelled by a = v.
  End