Time-dependent Lotkaian informetrics incorporating growth of sources and items

✍ Scribed by L. Egghe

• Publisher: Elsevier Science
• Year: 2009
• Tongue: English
• Weight: 441 KB
• Volume: 49
• Category: Article
• ISSN: 0895-7177
• DOI: 10.1016/j.mcm.2008.01.011

✦ Synopsis

In a previous article, static Lotkaian theory was extended by introducing a growth function for the items. In this article, a second general growth function -this time for the sources -is introduced. Hence this theory now comprises real growth situations, where items and sources grow, starting from zero, and at possibly different paces. The time-dependent size-and rank-frequency functions are determined and, based on this, we calculate the general, time-dependent, expressions for the h-and g-index. As in the previous article we can prove that both indices increase concavely with a horizontal asymptote, but the proof is more complicated: we need the result that the generalized geometric average of concavely increasing functions is concavely increasing.