객체 추적 시, 폐색에 관한 논문 http://www.google.co.kr/url?sa=t&rct=j&q=appearance%20models%20for%20occlusion%20handling&source=web&cd=1&ved=0CDMQFjAA&url=http%3A%2F%2Fciteseerx.ist.psu.edu%2Fviewdoc%2Fdownload%3Fdoi%3D10.1.1.140.6058%26rep%3Drep1%26type%3Dpdf&ei=f5YfUfvOG4bomAWR1oCgDA&usg=AFQjCNH2zwp511Jg41vtpHwKNO5oRYaCAQ&bvm=bv.42553238,d.aGc&cad=rjt 볼만한 가치가 있어서 일단 정리함.