Hybrid Topological Derivative-Gradient Based Methods for Nondestructive Testing

Figure 5

Reconstruction of objects when 𝑘_𝑖=1 is known, with the monotone algorithm (18). (a) Topological derivative when Ω=∅. (b)–(d) Approximate domains Ω_𝑚 superimposed to the topological derivative for Ω=Ω_𝑚. (e) Evolution of the cost functional.

(a)

(b)

(c)

(d)

(e)