Question
A form of this technique measures neutron absorbance with arrays of scintillators to determine the densities and fissile masses of layers of the test object. For 10 points each:
[10m] Name this class of imaging techniques used to study the internal structure of objects by “stacking” 2D transmission cross sections.
ANSWER: tomography (“tuh-MAH-grah-fee”) [accept any form of tomography, such as computed tomography scans, computed axial tomography scans, positron emission tomography, neutron tomography, X-ray tomography, or electron tomography; prompt on PET or CT or CAT scan by asking “what does that stand for?”; prompt on scans or scanning]
[10e] Tomographic reconstruction is an inverse problem that tries to find a 2D image given the results of performing this operation on the image many times. This operation maps an object to one less dimension, such as representing a 3D object on a flat surface.
ANSWER: projection [or projecting or other word forms of project]
[10h] This term is used for any image used to test tomographic reconstruction algorithms, such as the image of 10 overlayed ellipses introduced by Lawrence Shepp and Benjamin Logan.
ANSWER: phantom [accept Shepp–Logan phantom]
Data
| Team | Opponent | Part 1 | Part 2 | Part 3 | Total |
|---|---|---|---|---|---|
| Brown A | WUSTL A | 10 | 0 | 0 | 10 |
| Chicago A | Ohio State A | 0 | 10 | 10 | 20 |
| Chicago B | Duke A | 0 | 10 | 0 | 10 |
| Chicago C | North Carolina A | 10 | 10 | 0 | 20 |
| Claremont A | Iowa State A | 0 | 10 | 0 | 10 |
| Cornell A | Stanford A | 10 | 10 | 0 | 20 |
| Cornell B | Toronto A | 10 | 10 | 0 | 20 |
| Harvard A | Columbia A | 0 | 10 | 0 | 10 |
| Illinois A | Penn A | 0 | 10 | 0 | 10 |
| Johns Hopkins A | Florida B | 0 | 10 | 0 | 10 |
| Maryland A | Georgia Tech A | 0 | 10 | 0 | 10 |
| Michigan A | Houston A | 0 | 10 | 0 | 10 |
| Minnesota A | MIT A | 0 | 10 | 0 | 10 |
| NYU A | Imperial A | 0 | 10 | 0 | 10 |
| Purdue A | Minnesota B | 0 | 10 | 0 | 10 |
| Rutgers A | WUSTL B | 0 | 0 | 0 | 0 |
| Rutgers B | Columbia B | 0 | 10 | 0 | 10 |
| Texas A | Indiana A | 10 | 10 | 0 | 20 |
| UC Berkeley A | Northwestern A | 10 | 10 | 0 | 20 |
| UC Berkeley B | Vanderbilt A | 0 | 10 | 0 | 10 |
| Virginia A | Penn State A | 0 | 10 | 0 | 10 |
| Yale A | Florida A | 10 | 10 | 0 | 20 |
| Yale B | Georgia Tech B | 0 | 10 | 0 | 10 |