This paper proposes that horizontal competition exists between telecommunications carriers and data center interconnection (DCI) operators in DC-DC interconnections, and vertical competition exists between telecommunications carriers and DCI operators in end-user-DC interconnections. We build a new hybrid model using the Lotka-Volterra model and discuss the conditions to establish long-term equilibrium relationships.

We find that in equilibrium, multiple patterns, such as that either telecommunications carriers or DCI operators disappear and that telecommunications carriers and DCI operators coexist, exist in DC-DC interconnections as well as in end-user-DC interconnections. We also discuss the relationships between parameters for telecommunication carriers to maintain their share in DCI networks and policy proposals to realize these relationships. Two cases are observed: 1) DCI operators disappear in DC-DC interconnections. To realize this, regulations promoting the growth of telecommunication carriers’ data traffic while suppressing that of DCI operators’ data traffic are effective. 2) Telecommunication carriers and DCI operators coexist in DC-DC interconnections. To realize this, regulations promoting the saturation of both telecommunications carriers’ and DCI operators’ data traffic and differentiation that prevents from preying on each other's data traffic are effective.

In recent years, outreach activities, in which researchers in science and technology directly communicate their achievements to the public, have been attracting attention. In contrast to conventional public relations, which is a one-way communication, outreach is required to be interactive. Twitter, which is widely used, has the characteristics of openness, mass media functions, and interactivity, making it suitable for outreach. Moreover, it can be done by individuals. The purpose of this research is to show the conditions for effective outreach using the example of an astronaut with a large number of followers on Twitter. In order for information to be widely disseminated, it needs to be retweeted repeatedly. Therefore, I investigated what kind of tweets made by the astronaut were often retweeted. Specifically, I examined whether the results of advertising research and other studies could be applied, and I also added new elements. I also confirmed the phenomenon that when a very large number of retweets were made, the number of followers increased.

This paper researches and analyzes the recent developments of Section 230 of the U.S. Communications Decency Act, focusing on the EARN IT Act in the 116th Congress, and compares the contents of the bill with the recent EU and UK bills on intermediary liability, thereby clarifying the underlying issues and suggestions in the legal policy of this area. First, while imposing certain obligations on providers to deter illegal and harmful information may raise issues on competition law, the EUʼs asymmetric regulation may be a solution for it. Second, government involvement in the determination of such obligations may raise privacy and freedom of expression issues that, on the other hand, may be overcome by making such government involvement indirect. Third, securing transparency and accountability may be the main objective of legal policy rather than mandating certain decision variables.