Inferring conductivity from temperature measurements using ODIL and PINN. Temperature field (A) and conductivity function (B) inferred by PINN with Adam , ODIL with Adam , and ODIL with Newton compared to reference . The reference solution is from forward problem solved using ODIL on a finer grid. The temperature measurements in 200 points (black dots) are taken from the reference solution. History of root-mean-square error in temperature (C) and conductivity (D).