I searched everywhere but couldn't find a site that provide detailed clothes worn by the people of Korea in ancient time. I would like to search the changes in fashion and costume over time. Here are some examples that may be useful, but I'm really looking for a more detailed timeline:
One possible source is
Given that the authors are listed by their affiliation with Ewha's Women's University, I'm willing to bet that they have additional academic papers availble, and are probably willing to correspond on the topic and suggest other resources. I searched for the first author's name on the Ewha University site and got back results, but was unable to translate the Korean, even with the assistance of Google.
Cathy Raymond who is one of my go-to authorities on fashion disclaims any particular knowledge of Korean fashion, but recommended Hanbok: The Art of Korean Clothing which is apparently out of print, but may be available from a library. She also drew my attention to Chosun. She offered the following comment:
Moreover, historical costume research isn't that systematized. We have what we have on costume history in the West largely because we have had a lot of talented amateurs who've done and published research. Costume and textile study is still a bit of a ghetto for historians and archaeologists though that's finally changing, thank heaven.
Both that second source and a third source recommended wikipedia as a surprisingly good source.
Hope that is of some help.