was introduced by Has- san. Similarly, LDHCM (Linearly Decayed) and LGDHCM (LoGarithmically decayed), have their contributions reduced over time in a respectively linear and logarithmic fashion. Both are novel. The definition of the variants follow: EDHCM{a,..,b} (j) = P i2{a,..,b} HCP Fi(j) e 1⇥(|{a,..,b}| i) (5) LDHCM{a,..,b} (j) = P i2{a,..,b} HCP Fi(j) 2⇤(|{a,..,b}|+1 i) (6) LGDHCM{a,..,b} (j) = P i2{a,..,b} HCP Fi(j) 3⇤ln(|{a,..,b}|+1.01 i) (7) where 1, 2 and 3 are the decay factors. earlier periods of time, i.e., earlier modifications, have the contribution reduced exponentially over time, modelling a exponential decay model. EDHCM was introduced by Ha san. Similarly, LDHCM (Linearly Decayed) and LGDHC (LoGarithmically decayed), have their contributions reduce over time in a respectively linear and logarithmic fashion Both are novel. The definition of the variants follow: EDHCM{a,..,b} (j) = P i2{a,..,b} HCP Fi(j) e 1⇥(|{a,..,b}| i) (5 LDHCM{a,..,b} (j) = P i2{a,..,b} HCP Fi(j) 2⇤(|{a,..,b}|+1 i) (6 LGDHCM{a,..,b} (j) = P i2{a,..,b} HCP Fi(j) 3⇤ln(|{a,..,b}|+1.01 i) (7 where 1, 2 and 3 are the decay factors. Variants. We define three further variants based on HCM, with an additional weight for periods in the past. In EDHCM (Exponentially Decayed HCM) , entropies for earlier periods of time, i.e., earlier modifications, have their contribution reduced exponentially over time, modelling an exponential decay model. EDHCM was introduced by Has- san. Similarly, LDHCM (Linearly Decayed) and LGDHCM (LoGarithmically decayed), have their contributions reduced over time in a respectively linear and logarithmic fashion. Both are novel. The definition of the variants follow: EDHCM{a,..,b} (j) = P i2{a,..,b} HCP Fi(j) e 1⇥(|{a,..,b}| i) (5) LDHCM{a,..,b} (j) = P i2{a,..,b} HCP Fi(j) 2⇤(|{a,..,b}|+1 i) (6) LGDHCM{a,..,b} (j) = P i2{a,..,b} HCP Fi(j) 3⇤ln(|{a,..,b}|+1.01 i) (7) where 1, 2 and 3 are the decay factors.