In Fig 4, the credibility of node Zij belongs to community Ck is mainly decided by parameter Uik, αijk, and dij. According to the definition of NG, we have Uik=∑h=1Hαihk. Therefore, the clustering credibility of node Zij is only determined by αijk and dij. However, constrained by the number of RFID companies in real life, adequate samples cannot be collected. So αijk and dij obtained by the finite samples are not representative and only according to these two parameters, it is difficult to get the accurate clustering credibility of a node. Thus, we add offset εijk and βij to αijk and dij, respectively.