Per-year citation cycle time (renewal pace) along each flow trajectory

Recomputes the Citation Cycle Time (Kayal, 1999) from the documents in each sniff_trajectory_braid() trajectory's own group-year nodes, one value per year of the trajectory's life: per node-year, the median over its documents of each document's median cited-reference age. A low or falling series marks a fast-renewing knowledge stock, a diagnostic signal of emergence.

Usage

sniff_trajectory_cct(flow, references)

Arguments

flow

A sniff_trajectory_braid() object.

references

A long data frame with columns document_id and ref_age, one row per document-cited-reference, ref_age the reference's age in years (citing_year - cited_year). Build it from the corpus CR field joined to the cited works' publication years (e.g. the tracked_cr_py of sniff_cct()).

Value

A tibble, one row per trajectory: traj_id, type, group, and cct, a list-column whose each cell is a tibble with columns year and cct (the median citation age over that node-year's documents; NA when none of them carry references).

Details

This is the faithful, per-document counterpart of sniff_cct() (which scores a static sniff_groups() partition by group-year): it follows the trajectory's actual membership, so an absorbed tributary is scored on its own documents rather than its destination group's.

References

Kayal AA, Waters RC (1999). An empirical evaluation of the technology cycle time indicator. IEEE Trans. Eng. Manag. 46(2):127-31.

See also

sniff_cct(), sniff_trajectory_entropy(), sniff_trajectory_dynamics(), sniff_trajectory_braid()

Other trajectory analysis: sniff_trajectory_community(), sniff_trajectory_confluence(), sniff_trajectory_contribution(), sniff_trajectory_destination(), sniff_trajectory_dynamics(), sniff_trajectory_emergence_owners(), sniff_trajectory_entropy(), sniff_trajectory_formation(), sniff_trajectory_hubs(), sniff_trajectory_self_sufficiency()