In order to promote open citation of scholarly publications, I4OC (Initiative for Open Citations) has been launched by academic institutions and publishers. Open citation refers to citation data, which are structured, separable, and open. In this article, we analyze the citation data, which have been made available by I4OC, in order to understand the current status of open citation in Japan. The analysis reveals that while the percentage of publications with open citation data in the world is 24.22%, it is 18.86% in Japanese scholarly publications. In order to further promote open citation, it is necessary to support organizing and structuring citation data of past publications and publications in humanities.

We aimed at clarifying the characteristics of the Wikipedia editors who had added Digital Object Identifier (DOI) links to English Wikipedia as scholarly bibliographic references. The results are summarized as follows: (1) Approximately 930 thousand items classifiable into 22 research fields based on the Essential Science Indicators are identified by using DOI links. These items were added by 34,062 users, 31 bots, and 16,349 IP users. (2) Concentration in the number of DOI links on English Wikipedia added by Wikipedia editors is high as a whole (Gini coefficient 0.93), and most research fields’values are also high in common, due to the editors who added DOI links systematically to the existing references on a large scale.

　In recent years, many administrative organizations and local governments are engaged in opening and utilizing open data but until the data utilization has not reached where the government promotes "Open data can be secondarily used without much manpower being machine-readable". In this research, we propose a predicate vector method that measures the similarity of data by vectorizing item names and item values of CSV data disclosed to explore the possibility of open data of a local government. In addition, using the predicate vector method, we experimented on the possibility of cooperation between each data, and compared the degree of cooperation of each item name and the degree of cooperation of each column data among open data. As a result, it was shown that open data with a high degree of cooperation calculated from column data has a high degree of similarity of a specific column, making it easy to establish data cooperation.

A career development of the author is stated, mainly on the experiences related to the 'MLA Collaboration' and he outlined that 'MLA Collaboration' have made subtle changes in the exhibition spaces of art museums in Japan.

The digital archive system ADEAC (A System of Digitalization and Exhibition for Archive Collection) is operated as a cloud system at TRC-ADEAC Corporation. This system is currently used as a linkage system with Japan-search and EBSCO Discovery Service too. In this article, the purpose of ADEAC, usage status as of October 2019, and the system provision menu are reported, and the author mainly considers various uses about digital archives (digital content).