Review of Department of Defense Test Protocols for Combat Helmets (2014) / Chapter Skim
Currently Skimming:
7 Test Protocols for Backface Deformation: Statistical Considerations and Assessment
7 Test Protocols for Backface Deformation: Statistical Considerations and Assessment
Pages 48-53
The Chapter Skim interface presents what we've algorithmically identified as the most significant single chunk of text within every page in the chapter.
Select key terms on the right to highlight them within pages of the chapter.
From page 48... ...
, the Army has modified it exceeded its threshold. This original plan was based on the DOT&E protocol for application to the lightweight 20 shots; if no BFD measurements exceeded their limit, the Advanced Combat Helmet, so the effect of that modification demonstration was successful.
|
From page 49... ...
UTL is a 90 percent upper confidence bound for the and (2) black solid line corresponds to right, left, and crown. 90th percentile, so one can say with 90 percent confidence At the right side of Figure 7-1, the green line shows that, that at least 90 percent of the distribution is smaller than the if the underlying probability of a BFD "failure" is 0.10 for UTL (or at most 10 percent of the distribution exceeds the either location group, there is only a 10 percent chance of UTL)
|
From page 50... ...
Figure 7-3 overlays 0.4 the OC curve for that plan on the OC curves in Figure 7-2. 0.3 To have at least a 90 percent chance of passing the legacy 0.2 plan, the underlying BFD failure probability had to be 0.005 0.1 0.1 or less.
|
From page 51... ...
Figure 7-5 shows the OC curves for the situation in which the protocol is applied to a single group Army's Modified DOT&E Protocol for the Lightweight of 48 shots, and the combined curve is for the situation of all Advanced Combat Helmet five groups passing their individual margin tests. Figure 7-5 shows that for a manufacturer to have a 90 This protocol changed the grouping of the shots in the percent chance of passing all five acceptance tests by locasubsection above as follows: (1)
|
From page 52... ...
this assumption. A natural concern in converting continuous measurements • The graphical diagnostics that were shown to the to binary data is the loss of statistical efficiency. However, committee indicate that the normality assumption is recall that the goal of the test protocols is to determine if the not unreasonable for the limited data sets that have BFD measurements exceed their corresponding thresholds.
|
From page 53... ...
Available backface deformation converting the continuous BFD measurements to 0-1 out- (BFD) data should be used to develop data-based limits comes.
|
Key Terms
This material may be derived from roughly machine-read images, and so is provided only to facilitate research.
More
information on Chapter Skim is available.