Inverse Scattering from a Sound-Hard Crack via   Two-Step  Method

<table class="table-group" width="800px"><tr class="fig-image" id="a"><td><img alt="810676.fig.004a" src="https://static.hindawi.com/articles/aaa/volume-2012/810676/figures/810676.fig.004a.jpg"/></td></tr><tr class="fig-caption"><td align="center"><table><tr><td><b>(a) </b>Exact data, <svg height="11.3125" id="M140" style="vertical-align:-0.1092pt" version="1.1" viewbox="0 0 50.724998 11.3125" width="50.724998" xmlns="http://www.w3.org/2000/svg" xmlns:xlink="http://www.w3.org/1999/xlink">
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l350 -516h5l48 257q25 131 25 171q0 34 -17.5 45t-77.5 15l7 28h240z" id="x1D441"></path></g><g transform="matrix(.017,0,0,-.017,19.628,11.113)"><path d="M535 323h-483v50h483v-50zM535 138h-483v50h483v-50z" id="x3D"></path></g><g transform="matrix(.017,0,0,-.017,34.332,11.113)"><path d="M412 140l28 -9q0 -2 -35 -131h-373v23q112 112 161 170q59 70 92 127t33 115q0 63 -31 98t-86 35q-75 0 -137 -93l-22 20l57 81q55 59 135 59q69 0 118.5 -46.5t49.5 -122.5q0 -62 -29.5 -114t-102.5 -130l-141 -149h186q42 0 58.5 10.5t38.5 56.5z" id="x32"></path></g><g transform="matrix(.017,0,0,-.017,42.491,11.113)"><path d="M456 178h-96v-72q0 -51 12.5 -62.5t72.5 -16.5v-27h-256v27q65 5 78 17t13 62v72h-260v28q182 271 300 426h40v-407h96v-47zM280 225v295h-2q-107 -148 -196 -295h198z" id="x34"></path></g>
</svg></td></tr></table></td></tr><tr class="fig-image" id="b"><td><img alt="810676.fig.004b" src="https://static.hindawi.com/articles/aaa/volume-2012/810676/figures/810676.fig.004b.jpg"/></td></tr><tr class="fig-caption"><td align="center"><table><tr><td><b>(b) </b>3% error, <svg height="11.375" id="M141" style="vertical-align:-0.1638pt" version="1.1" viewbox="0 0 50.724998 11.375" width="50.724998" xmlns="http://www.w3.org/2000/svg" xmlns:xlink="http://www.w3.org/1999/xlink">
<g transform="matrix(.017,0,0,-.017,.062,11.113)"><path d="M857 650l-6 -28q-44 -4 -61.5 -16.5t-29.5 -48.5q-11 -32 -37 -166l-78 -399h-29l-351 537h-4l-56 -276q-24 -120 -24 -164q0 -35 17.5 -46t75.5 -15l-6 -28h-245l7 28q41 2 62 14t31 44q10 30 41 171l53 245q8 44 6.5 60.5t-14.5 33.5q-10 15 -27 19.5t-64 6.5l6 28h153
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</svg></td></tr></table></td></tr></table>

Abstract and Applied Analysis

Inverse Scattering from a Sound-Hard Crack via Two-Step Method

Figure 4