We conducted a time-series analysis to clarify the sustainability for adding scholarly bibliographic references to English Wikipedia (enwiki). The results are summarized as follows: The characteristics of the trends between the edits in enwiki as a whole and the adding the references are different in the point that the latter keeps a certain scale at recent years. The number of editors adding the references has seasonal growth trends in April and November every year since 2011. The majority of new editors for adding the references contribute for single month only, but the scale of the editors remains flat in recent years. These characteristics in the editors adding the references seem to be affected by the participants of Wiki Education, so adding the references would be sustainable as long as these activities continue.

　More than 800 institutional repositories exist in Japan, but only a few institutions are active in registering journal articles. In this study, we analyzed the causal relation between the number of journal articles and librarians’ open access promotion activities to provide good practice guidelines to the institutional repository community. Quantitative analysis results using data from 87 domestic institutions showed “request for journal articles”, a direct approach to researchers, was estimated particularly influential in increasing the number of journal articles. On the other hand, activities, for instance, in developing an “open access policy” or implementing “self-archiving” were found less influential. Additional collected data from 4 institutions regarding the “request for journal articles” to understand the details of the causal relation revealed an annual success rate averaged 36.32%. Furthermore, the data showed the annual success rate of an institution implementing it most effectively averaged 55.82%, reaching a peak of 73.20%.

　This article investigates the state of Open Access (OA) in Japan and the world using a dataset provided by Unpaywall. The analysis covers two million articles for Japan and 80 million articles for the world. We find that the percentages of OA articles in Japan and the world are 41.83% and 29.77%, respectively. A reason for the high percentage in Japan is that many articles published a long time ago belong to the bronze category. As a trend in recent years, the analysis reveals the percentage of articles in the gold category has increased. Regarding the contribution of institutional repositories (IRs) to OA, we observe the percentage of articles available in IRs increased from 2000 to 2010. However, the percentage has been flat, at 5%, since 2010. The percentage of articles that are OA only in IRs is 1.5%. To promote green OA efficiently, it is necessary to enable each institution to grasp its state of OA by e.g., developing a system that continuously monitors levels for each institution.

　The Revised Law for the Protection of Cultural Properties in Japan came into force in April, 2019. In this revision, cultural heritages are expected to be utilized in local community. However, it is difficult to access such local cultural heritage information. In this research, we proposed metadata models and functions which suitable for aggregation cultural property lists published by local public bodies on the Web and linking to other resources with Linked Data in order to improve discoverability of local cultural heritage information. Based on this, we developed a system and evaluated it. The result showed that the system improved discoverability of reliable local cultural heritage information including books and web pages over local public bodies.

　Since the homogenized bipartite graph was proposed as a structure that can represent the knowledge information structure, there has been little discussion on its formal description and parser implementation. In this paper, we show that the representation of the structure is difficult in a conventional language, and propose a new language to represent a homogenized bipartite graph structure and its parser implementation. In addition, we describe some applications using the proposed mechanism and the perspectives on structuring knowledge and interpreting structured (formalized) knowledge. We also describe the tools implemented for the proof of concept. This tool is the first language that can formally describe a homogenized bipartite graph structure. This paper uses a style in which facts and considerations are mixed.