Many studies have tried to describe patterns of research collaboration through observing coauthorship networks. Those studies mainly analyze static networks, and most of them do not consider the development of networks. In this study, we turn our attention to the development of personal collaboration networks. On the basis of an analysis from two viewpoints, i.e., growth in the number of collaborating partners and change in the relationship strength with partners, we describe and compare the characteristics of four different domains, i.e., electrical engineering, information processing, polymer science, and biochemistry.
Authors:Fuyuki Yoshikane, Yutaka Suzuki and Keita Tsuji
Conventional patent citation analyses have focused mainly on the presence of citation relationships, the number of patents cited by the subject patent, and the number of times the subject patent is cited by others (i.e., the numbers of backward and forward citations of the subject patent). However, most of them have not focused on patent classifications. Assuming that a patent based on a variety of technological bases tends to be an important patent that is cited more often, this study examines and clarifies the relationship between the diversity of classifications assigned to backward citations and the number of forward citations for Japanese patents. The results show notable differences in the number of classifications assigned to backward citations between the often cited and less frequently cited groups. It is considered that the diversity of backward citations can be utilized in the evaluation criteria for grouping that roughly identifies the often cited patents or eliminates a large part of less frequently cited patents.
Authors:Fuyuki Yoshikane, Takayuki Nozawa and Keita Tsuji
Many studies have analyzed “direct” partnerships in co-authorship networks. On the other hand, the global network structure,
including “indirect” links between researchers, has not yet been sufficiently studied. This study analyzes researchers' activities
from the viewpoints considering their roles in the global structures of co-authorship networks, and compares the co-authorship
networks between the theoretical and application areas in computer science. The modified HITS algorithm is used to calculate
the two types of importance of researchers in co-authorship networks, i.e., the importance as the leader and that as the follower.
Authors:Fuyuki Yoshikane, Takayuki Nozawa, Susumu Shibui and Takafumi Suzuki
Although many studies have analyzed the “synchronic” correlation of properties between authors and their co-authors, the “diachronic”
correlation of properties, i.e., the correlation between their subsequent and precedent activity, has not yet been sufficiently
studied using quantitative methods. This study pays attention not only to productivity but also the importance in the collaboration
network as a measure of the researcher’s activity, and clarifies whether there is any connection between (i) the researcher’s
activity subsequent to a collaboration and (ii) the collaborator’s precedent activity, aiming at deriving knowledge about
the diachronic effect of collaborators.