This is the 1033rd most frequent Korean word.
연구원은
"Researcher" or "research institute staff."
In this sentence, '연구원은' is used as the subject, indicating the person performing the action, namely the researcher who developed something.
연구원은 새로운 치료법을 개발했습니다.
The researcher developed a new treatment method.
Here, '연구원은' refers to the team of researchers who are collectively the subject performing the completion of the project.
연구원은 프로젝트를 성공적으로 마쳤습니다.
The researchers successfully completed the project.
In this sentence, '연구원은' acts as the subject emphasizing the individual's role in the ongoing contribution to their field.