Real Event Data Research Articles

Methodology for evaluation of impact injury criteria using real crash injury outcomes and event data recorders

The objective of the present study is to synthesize and investigate using the same set of sixty-one real-world accidents the human head injury prediction capability of the head injury criterion (HIC) and the head impact power (HIP) based criterion as well as the injury mechanisms related criteria provided by the simulated injury monitor (SIMon) and the Louis Pasteur University (ULP) finite element head models. Each accident has been classified according to whether neurological injuries, subdural haematoma and skull fractures were reported. Furthermore, the accidents were reconstructed experimentally or numerically in order to provide loading conditions such as acceleration fields of the head or initial head impact conditions. Finally, thanks to this large statistical population of head trauma cases, injury risk curves were computed and the corresponding regression quality estimators permitted to check the correlation of the injury criteria with the injury occurrences. As different kinds of accidents were used, i.e. footballer, motorcyclist and pedestrian cases, the case-independency could also be checked. As a result, FE head modeling provides essential information on the intracranial mechanical behavior and, therefore, better injury criteria can be computed. It is clearly shown that moderate and severe neurological injuries can only be distinguished with a criterion that is computed using intracranial variables and not with the sole global head acceleration.

Analysing event data from a repairable machine subject to imperfect preventive maintenance

A machine is minimally repaired on failure and imperfect preventive maintenance (PM) is also carried out from time to time, not necessarily at regular intervals. A simple point process model is proposed for the sequence of corresponding failure times, and estimates of the machine lifetime parameters and the degree of age rejuvenation at PMs are obtained using maximum likelihood techniques. These results are then applied to real event data. © 1997 John Wiley & Sons, Ltd.

Parallel processor trigger with distributed real-time kernel

A second-level trigger system, based on 40 microprocessors working in parallel, has been designed and is being installed in the VENUS experiment. The purpose of the system is to find particle tracks in the central drift chamber online during analog-to-digital conversion, in about 10 ms. The hardware is designed to be easily modified by software to obtain the optimum configuration for the task at hand. To realize sufficient computing power for the task, the task must be divided and distributed to processors as evenly as possible, and a good balance between computation and communication load must be achieved. To be able to manage such a complicated system, several software tools have been developed. The software for the system has been entirely written in high-level language. Sufficient performance for the trigger operation has been obtained in tests with real event data. >