A second study by researchers at Yonsei University in Seoul , South Korea , and Johns Hopkins University looked at 1.2 million Koreans ages 30 to 95 and followed them for 12 years .
South Korea /location/location/contains Seoul
Seoul /location/administrative_division/country South Korea
South Korea /location/country/administrative_divisions Seoul
South Korea /location/country/capital Seoul
DT JJ NN IN NNS IN NNP NNP IN NNP , NNP NNP , CC NNP NNP NNP VBD IN CD CD NNPS NNS CD TO CD CC VBD PRP IN CD NNS .