Yeah the first one translate into Korean (w/ Chinese Characters) with "Joong", or "Middle".. and the second one is I believe is "Shim", Which translates into Heart, as suggested above. "Joong Shim" together in Korean means Center, Focus, or Concentration.. All are acceptable definitions.
Hi there. No offence but you do know that although "中" and "心" are both Chinese characters, "忠" alone is a also character meaning loyal, right? To me, it makes more sense that it is a "忠" meaning loyal than "中" "心" meaning middle heart or center.
