Academic landscape of innovation research was analyzed by citation network analysis, which was divided into three main clusters; with "technological innovation" as the central core together with "innovation fundamentals" and "innovation management". Historically, research on innovation started...

The nature of the dynamics of opinion formation or zero-temperature Ising models modeled as a decision-by-majority process in complex networks is investigated using eigenmode analysis. The Hamiltonian of the system is defined and estimated by eigenvectors of the adjacency matrix constructed from...

In this study, we analyze the network effect in a model of a personal communication market, by using a multi-agent based simulation approach. We introduce into the simulation model complex network structures as the interaction patterns of agents. With complex network models, we investigate the...

Social phenomena are affected by the structure of networks consisting of personal relationships. In the present paper, the diffusion of information among people is examined. In particular, the relationship between the network structure and the dynamics is studied. First, several networks are...

We study how initial network structure affects the evolution of cooperation in a spatial prisoner’s dilemma game. The network structure is characterized by various statistical properties. Among those properties, we focus on the variance of the degree distribution, and inquire how it affects...

After the Fukushima nuclear disaster, a reassessment of the energy system is needed in order to include such aspects as human security and resilience. More open and careful discussions are needed concerning the various risks and uncertainties of future energy options, both in Japan and globally....

The decision-making process that precedes the introduction of a new energy system should strive for a balance among human security, environmental safeguards, energy security, proliferation risk, economic risks, etc. For nuclear energy, the Fukushima Daiichi nuclear disaster (Fukushima disaster)...