3 papers
physics.data-an2020
The statistical physics of discovering exogenous and endogenous factors in a chain of events
Shinsuke Koyama, Shigeru Shinomoto
Event occurrence is not only subject to the environmental changes, but is also facilitated by the events that have occurred in a system. Here, we develop a method for estimating su…
physics.soc-ph2018
Identifying exogenous and endogenous activity in social media
Kazuki Fujita, Alexey Medvedev, Shinsuke Koyama +2
The occurrence of new events in a system is typically driven by external causes and by previous events taking place inside the system. This is a general statement, applying to a ra…
stat.ME2018
Modeling event cascades using networks of additive count sequences
Shinsuke Koyama, Yoshi Fujiwara
We propose a statistical model for networks of event count sequences built on a cascade structure. We assume that each event triggers successor events, whose counts follow additive…