“…which is the least square method for the measured result yi,j and the calculated result fi,j; NS and ND are the numbers of the sources and detection fibers used in measurements, respectively; Hi,j = 1 except for seven source-detection combinations that were excluded due to insufficient SNR. For the excluded pairs (i, j) = (2, 1), (2,6), (3,3), (3,8), (5,1), (5,6), and (7,6), Hij = 0. We used Tikhonov regularization, and τ is the hyper parameter; NR is the number of points of the reconstructed grid used to solve the inverse problem.…”