Evolutionary Biological Data Science Laboratory

dynamic discounted cumulated impact (sharp decay)

The dynamic discounted cumulated impact index (Järvelin and Pearson 2008; Ahlfren and Järvelin 2010) is an addendum to the discounted cumulated impact (sharp decay) which cumulates across different time intervals, rather than a single fixed interval. Formally, it is a vector defined as:

$$\text{dDCI}_Y\left[j\right]=DCI_j\left[j\right] ,$$

where DCI_j[j] is essentially the last item in the DCI vector for time interval j. When calculated for a career, where each subsequent interval is the length of the career up to that point, the values calculated for earlier career points are identical those same intervals for later career points, thus we just report the final value for each year, with all values up to that year actually representing the full dDCI vector.

Because DCI can be calculated with varying degrees of citation decay, dDCI is also dependent on this same decay. This version is calculated from the DCI index with a sharp decay of b = 2.

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