The authors and G-Search Limited are collaborating to develop a search engine "JDream Expert Finder" (JDEF) as an outcome of the project-8 in the Life Intelligence Consortium (LINC). JDEF has a function to find young promising researchers, who, so far, have only a little publication in the literature database of Japan Science and Technology Agency (JST). Using conventional citation indicators such as h-Index, it is inadequate to measuring young researchers' performances. Therefore, we have focused on the betweenness centrality in co-authorship networks as an alternative indicator. As JDEF has utilized a growth model of Japan Society for the Promotion of Science (JSPS) research fellows, thus, it is able to search the other young promising researchers from the JST database.