Interests (Research)

Page | Last updated at 2010/02/21 21:43

I like reading, traveling and thinking. Thus I'm living as a researcher. These are simple description about research topics what I'm working on.

(Visit Publications page for detailed information.)

Heterogeneous complex network (a.k.a. multi-layer network) analyses

Complex network theory is one of a useful tools to study complex systems. Network theory treats elements and their connections as nodes and links , which helps us study systems as a structural point of view.

It needs an assumption that every nodes (and links) belong to the same tribe to apply complex network theory to empirical systems. By the way, many systems does not match this assumption. For instance, telecommunication network is usually considered as one network. However the network is also 'networks' of many telecommunications companies. In reality many systems can be treated not only as a network, but as a group of heterogeneous networks.

I'm interested in suggesting proper measurement indexes for complex networks, studying the properties of heterogeneous networks.

Ultrafast analysis of big data

Since 2006, I am focusing on big scale data treatment in a proper time. I'm focusing on ultra-fast analysis of big data, including bio-time series (specially, brain wave), agent-model simulation log, human activities and communication log between devices. Currently, I am making data research platform by combining nonlinear time series analytics (my major) and data science field experience.

Opinion formation dynamics on complex systems

My main interest is the process of creating and changing opinions. Literally 'opinion' is an example of opinion formation process of complex system. People make their own opinion about specific issue by communicating each other.We can define 'opinion' on many systems even if the meaning is a little bit different from common sense. For example, atoms have spin, and spin is decided by neighbors' spins and external magnetic field. In this case we can tell the spin value of atom as its opinion. Brain 'thinks' by exchanging information streams between brain components. In the different point of view, we can translate this procedure differently. Each brain component has opinion and they dynamically change their opinions.

The reason why we can study these physics, sociology, biology examples as a same frame is that they share the common properties. An element decide its opinion by neighbors' and external environment. People create their own opinion not only with the conversation between his friends, but with the information from mass-media. Opinion formation dynamics is mainly affected by local and global information. By the reason that local information is real-time changing opinions of neighborhood, opinion formation has a strong feedback routine inside. Thus it's a very complex process.

I'm studying about the opinion formation dynamics, starting from the simple model based on complex network, to various empirical systems.

  • Common opinion formation procedure found at different systems
  • Ingredients to make opinion formation procedure different from many systems.