3D imaging of metal grains Bragg-edge imaging Debye-Waller factor History of engineering & technology Levenberg-Marquardt method Rayleigh-Sommerfeld integral (RSI) SA106 carbon steel Shim stock films Technology: general issues UWB-OOK UWB-PPM acoustic nonlinearity parameter adaptive fusion attention mechanism austenite-to-martensite transformation austenitic stainless steel buried objects circulating fluidized bed combustion boiler coded-aperture imaging composite materials composites computer vision convolution neural network (CNN) convolutional neural network deep learning eddy current nondestructive testing embedded damage fast image reconstruction finite-width plate flexible ultrasonic probe