Official websites use .gov
A
.gov website belongs to an official
government organization in the United States.
Secure .gov websites use HTTPS
A lock (
) or https:// means you've safely
connected to the .gov website. Share sensitive
information only on official, secure websites.
The scientific cooperation network. A: Country cooperation, B: Institution cooperation, C: Author cooperation, i: Author clustering as represented by DUKWOO PARK; ii: Author clustering as represented by MYEONGKI HONG; iii: Author clustering as represented by RON WAKSMAN; iv: Author clustering as represented by ANTONIO COLOMBO. Number: frequency of co-occurrence.
