Weekly Update for October 30

Hamby-44 Re-scan

• Hamby set 44: two test fires each from ten consecutive barrels, 15 questioned bullets
• Hamby set 44 is part of NIST ballistics dataset
• all 35 bullets are now re-scanned with higher resolution CLM

Hamby-44: Questioned versus known bullets

• for which bullets would you request re-scans?

Intervals for Random Forest Predictions

• Intervals constructed from predicted probabilities from many random forest classifiers.
• Widths increase as probabilities approach 0.5.
• Similar results to modeling individual tree classifications as binomial and making intervals for each p.

Previous

• Adjusted Chumbley Algorithm proposed by Hadler et al. applied to bullet signatures on all pairwise land-to-land comparisons of the Hamby scans ( a total of 85491 comparisons)
• Identified the window of optimization and window of validation for the chumbley algorithm for Bullet Signatures for the Hamby-44 and Hamby-252.

Profiles

• Trying to see how the chumbley algo works when profiles are used instead of signatures
• Chumbley algo uses a LOwEss smoothing with a default coarseness as 0.25, the idea is to first identify what coarseness would give us best results in terms of type I and type II errors.
• Window of optimization and validation used is the same as identified for signatures.

3D Scans

• Computed: Root Mean Squared
• Software: Cloud Compare
• Algorithm: Iterative Closest Point
• URL: Cloud Compare Wiki

Cloud Compare

Cloud Compare

Adidas

Nike

Worn Nike 10

Worn Nike 10.5

Grapheme Separation for London

South Dakota

• Clark, South Dakota is home to the world famous Mashed Potato Wrestling Contest.
• Mitchell is the home of the world’s only Corn Palace, which is made of 3500 bushels of corn.
• Pierre, South Dakota is the only combination of state and capital in the U.S. that doesn’t share any letters.
• Mount Rushmore took 14 years and only 1 million dollars to build.
• In Deadwood a permit is required to mix one alcoholic beverage with another. But you can mix all the beer you want.
• It is also illegal there for casinos to hang a sign saying “Casino”.