Shock absorbers for integration into protective structures generally take the form of hollow, compressible cells. The apparatus includes a fiber mount assembly having a body portion with an opening provided therein to receive the optical fiber, and two leg portions integrally connecting to and extending from the body portion. Usage data is collected more frequently as the probability increases. This can lead to increased nitrogen oxide emission both during the regeneration itself and after the engine has been switched back to lean-burn mode.