  The h-index, introduced by Hirsch, is based on the mutual variation between
the number of cited and source items. The temporally continuous nature of the
citation accretion process causes a shift of cited items from the h-core zone
to the adjacent citation-asymmetric zones, viz. h-excess zone, or h-tail zone.
The name given to this shifting phenomenon is the Diffusion of Cited Items
(DCI). In this paper, two new variables are introduced, i.e., the Fold of
Excess citation over Total citations (FET), denoted by $\epsilon^2$ and the
Fold of h-core citation over Excess citations (FHE), denoted by $\theta^2$. On
the basis of $\theta$ and $\epsilon$, another indicator is introduced, i.e.,
the Citation Swing Factor (CSF), defined as $d\theta/d\epsilon$, which
indicates the differential coefficient of $\theta$ with respect to $\epsilon$.
The time dependence of FET and FHE is also discussed. The possible solutions of
are derived here. The functionality of CSF ($d\theta/d\epsilon$) to measure the
diffusion process quantitatively will be tested later on for journals, authors
and institutions.
