FLAIR: VLAD and FISHER VECTOR descriptor in Matlab

i've to model the MATLAB of VLAD and FISHER VECTOR descriptors but i've not understood what is the FLAIR scheme and how it links these two descriptors.

How can i find ispiration to model these FLAIR? I've no idea. I cannot find anything on the internet, only one paper (<http://isis-data.science.uva.nl/cgmsnoek/pub/sande-flair-cvpr2014.pdf>) that i cannot understand.

Thank you