Not Korean - but Chinese. The symbols are from I Ching (Book of Changes). Going clockwise from the hole, the English names, attributes, images and family relationships are:
Keeping still, resting, mountain, 3rd son
Arousing, inciting movement, thunder, 1st son
Gentle, penetrating, wind/wood, 1st daughter
Clinging, light giving, fire, 2nd daughter
Receptive, devoted/yielding, earth, Mother
Joyous, joyful, lake, 3rd daughter
Creative, strong, heaven, Father
Abysmal, dangerous, water, 2nd son
That's enough for now. I stuck my notes in the bag along with the TB. Someone else can tackle the other side once the weather clears up and I drop it in another cache.