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Every day railcars are setout for repair based on wayside detector absolute alarm limits. These alarms successfully identify most of the cars capable of causing derailments. There would be thousands of additional cars set out if these absolute alarms were lowered to the levels required to remediate the remaining cars capable of causing derailments. The rail industry cannot tolerate this level of setouts, nor can it tolerate derailments. A more focused approach is required. BNSF has developed a Composite Rules Engine (CRE), which combines and evaluates the data currently gathered by each individual wayside detection system. It is capable of pin-pointing the worst of the worst among the remaining cars exhibiting elevated detector readings. CRE provides BNSF the means of bridging its stand alone detection systems to provide one centralized alarming system. The CRE is able to combine the separate rule flows of: Acoustic Bearing Detectors (ABD), Machine Vision Systems (MVS), Truck Hunting Detectors (THD), Truck Performance Detectors (TPD), Hot Bearing Detectors (HBD), a Warm Bearing Detection System (WBDS), Hot / Cold Wheel Detectors (HW) and Wheel Impact Load Detectors (WILD). In summary, CRE targets cars with multiple low level indications that, individually, are of little concern, but collectively have the potential to cause derailments.

Head-related transfer functions (HRTFs) play a significant role in modern acoustic experiment designs in the auralization of 3-dimensional virtual acoustic environments. This technique enables us to create close to real-life situations including room-acoustic effects, background noise and multiple sources in a controlled laboratory environment. While adult HRTF databases are widely available to the research community, datasets of children are not. To fill this gap, children aged 5–10 years old were recruited among 1st and 2nd year primary school children in Aachen, Germany. Their HRTFs were measured in the hemi-anechoic chamber with a 5-degree × 5-degree resolution. Special care was taken to reduce artifacts from motion during the measurements by means of fast measurement routines. To complement the HRTF measurements with the anthropometric data needed for individualization methods, a high-resolution 3D-scan of the head and upper torso of each participant was recorded. The HRTF measurement took around 3 min. The children’s head movement during that time was larger compared to adult participants in comparable experiments but was generally kept within 5 degrees of rotary and 1 cm of translatory motion. Adult participants only exhibit this range of motion in longer duration measurements. A comparison of the HRTF measurements to the KEMAR artificial head shows that it is not representative of an average child HRTF. Difference can be seen in both the spectrum and in the interaural time delay (ITD) with differences of 70 μs on average and a maximum difference of 138 μs. For both spectrum and ITD, the KEMAR more closely resembles the 95th percentile of range of children’s data. This warrants a closer look at using child specific HRTFs in the binaural presentation of virtual acoustic environments in the future.

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