Need explanation of Segmentation (FCN + UNET) papers

I need explanation of those 2 segmentation algorithms:
1. Fully Convolutional Network (FCN)
2. U-Net

explain the architectures , mathmatics , strong and limitations , etc.

I need to explain them through zoom , number of sessions needed will be decided later.

An academic person is needed with CS speciality – Computer vision and deep leaning.
Thank you