# Michael S. Rosenberg’s Laboratory

Computational Evolutionary Biology & Bioinformatics

E-mail: msr@asu.edu
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## dynamic discounted cumulated impact (mild decay)

The dynamic discounted cumulated impact index (Järvelin and Pearson 2008; Ahlfren and Järvelin 2010) is an addendum to the discounted cumulated impact index 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 DCIj[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 mild decay of b = 10.

### History

YeardDCI (b = 10)
19972.0000
199813.0000
199936.0000
200067.0000
2001133.0000
2002240.0000
2003367.0000
2004585.0000
2005845.0000
20061176.0000
20071509.0000
20081889.9205
20092315.4160
20102785.0741
20113212.7001
20123594.0476
20134028.8151
20144459.7149
20154863.6499
20165250.9203
20175524.7233

## References

• Ahlgren, P., and K. Järvelin (2010) Measuring impact of 12 information scientists using the DCI-index. Journal of the American Society for Information Science and Technology 67:1424–1439.
• Järvelin, K., and O. Pearson (2008) The DCI-index: Discounted impact-based research evaluation. Journal of the American Society for Information Science and Technology 59:1433–1440.