수소 신기술 주제를 국가적 수준 비교로 진행한 논문이다 https://www.sciencedirect.com/science/article/pii/S0306261922003245 Investigating emerging hydrogen technology topics and comparing national level technological focus: Patent analysis using a stru Hydrogen technology has recently attracted great attention as a new energy technology with a potential to transform existing energy systems. However, … www.sciencedirect...