I saw this in the floor of a subway station. These are the four cardinal directions, N, E, S, W, in that order as you would expect to find in a compass. The outer characters are Hangul(Korean), the inner ones are Iching.
You also see I Ching in the Korean flag.
The white background symbolizes “cleanliness of the people”. The Taegeuk represents the origin of all things in the universe, holding the two principles of yin and yang in perfect balance—the former being the negative aspect rendered in blue, and the latter as the positive aspect rendered in red. Together, they represent a continuous movement within infinity, the two merging as one.
The I Ching here stands for (starting top-left): Justice, Fruition, Wisdom, Vitality.
The earliest Korean flag (pre-1800, Joseon Dynasty) looked quite a but different.