Search for content and authors
 

The probability distributions and the fluctuation scalings of the time series of key-word counts in nation-wide blog data.

Hayafumi Watanabe 1Yukie Sano 6Hideki Takayasu 2,3,4Misako Takayasu 5

1. The institute of Statistical Mathematics, Tokyo 190-8562, Japan
2. Sony Computer Science Laboratories (SONYCSL), 3-14-13 Higashigotanda Shinagawa, Tokyo 141-0022, Japan
3. Tokyo Institute of Technology, Yokohama 226-8502, Japan
4. Meiji University, 4-21-1 Nakano, Tokyo 164-8525, Japan
5. Tokyo Institute of Technology, Nagatsuda-Cho 4259,Midori-ku, Yokohama, Yokohama 226-8502, Japan
6. Tsukuba Univ., Tsukuba 305-8577, Japan

Abstract

 In analyses of social media data, one of the most important basic objects is the time series representing the appearance of considered keywords. We aim to describe this fluctuation precisely, whereas the majority of previous research has focused on “trends” in the time series (i.e., nonrandom parts of the time series) for practical reasons.

To elucidate the nontrivial empirical statistical properties of fluctuations of a typical nonsteady time series representing the appearance of words in blogs, we investigated approximately 3 billion Japanese blog articles over a period of six years and analyse some corresponding mathematical models.

First, we introduce a solvable nonsteady extension of the random diffusion model, which can be deduced by modeling the behavior of heterogeneous random bloggers. Next, we deduce theoretical expressions for both the temporal and ensemble fluctuation scalings of this model, and demonstrate that these expressions can reproduce all empirical scalings over eight orders of magnitude. Furthermore, we show that the model can reproduce other statistical properties of time series representing the appearance of words in blogs, such as functional forms of the probability density and correlations in the total number of blogs. As an application, we quantify the abnormality of special nationwide events by measuring the fluctuation scalings of 1771 basic adjectives.

[1] Phys. Rev. E 94, 052317 (2016)

 

Legal notice
  • Legal notice:
 

Related papers

Presentation: Oral at Econophysics Colloquium 2017, Symposium C, by Hayafumi Watanabe
See On-line Journal of Econophysics Colloquium 2017

Submitted: 2017-03-20 03:01
Revised:   2017-03-20 03:44