There are various uses of the word "shim". As can be seen from the wikipedia article:
https://en.wikipedia.org/wiki/Shim
Here, we are concerned with the surname Shim.
In terms of syntax, there are 2 major groups using the surname Shim:
Here, we are concerned with the Chinese Shim.
The Chinese root word for shim is: 沈
However, it is pronounced differently depending on the Chinese dialect. Therefore the corresponding English transliteration of the Chinese character are:
Here, we are concerned with the Chinese Hakka Shim.