Probability Of AIS Research Articles

Response and Tolerance of Female and/or Elderly PMHS to Lateral Impact.

Eight whole fresh-frozen cadavers (6 female, 2 male) that were elderly and/or female were laterally impacted using UMTRI's dual-sled side-impact test facility. Cadavers were not excluded on the basis of old age or bone diseases that affect tolerance. A thinly padded, multi-segment impactor was used that independently measured force histories applied to the shoulder, thorax, abdomen, greater trochanter, iliac wing, and femur of each PMHS. Impactor plates were adjusted vertically and laterally toward the subject so that contact with body regions occurred simultaneously and so that each segment contacted the same region on every subject. This configuration minimized the effects of body shape on load sharing between regions. Prior to all tests, cadavers were CT scanned to check for pre-existing skeletal injuries. Cadavers were excluded if they had preexisting rib fractures or had undergone CPR. Cadavers were instrumented with strain gages at the posterolateral, lateral, and anterolateral portions of the struck-side ribs, and chestbands were positioned on the upper and lower thorax. Cadavers were first impacted at 3 m/s. If two or fewer rib fractures occurred, as determined using strain gage data and a post-test CT scan, a second impact was performed at 6 m/s on the contralateral side of the body. Five of the eight 3-m/s tests produced AIS 3+ level injuries. All three of the 6-m/s tests produced AIS 3+ injury. Response corridors were developed for each body region using the Maltese alignment method with impulse-momentum normalization. Corridors describing upper and lower thorax deflection were generated from chestband data. An injury risk curve developed from the deflections associated with AIS 3+ injury associates a 50% probability of AIS 3+ rib fracture with 25.6% half-thorax deflection for the population used in this study.

Development of head injury risk functions based on real-world accident reconstruction

The objective of this study is to assess head injury risks of adult pedestrians using computer reconstructions of the accidents. For this purpose, accident reconstructions were developed based on the real-world pedestrian accidents. The impact conditions, which were obtained from the previous study [Y. Peng, C. Deck, J.K. Yang, D. Otte, and R. Willinger, A study of adult pedestrian head impact conditions and injury risks in passenger car collisions based on real world accident data, Traffic Inj. Prev., doi: 10.1080/15389588.2012.733841] including head impact velocity, head position and head orientation, were defined as initial loading conditions in a simulation of the head striking to a windscreen by using a finite element (FE) Hybrid III head model. Logistic regression models were developed to study brain injury risk with respect to injury related variables: the head linear acceleration, HIC value, skull fracture correlate (SFC), resultant angular acceleration and head impact power (HIP). The results from Hybrid III head impact simulations indicated that the predicted head linear acceleration, HIC value, resultant angular acceleration and HIP for 50% probability of AIS 2+ and AIS 3+head injury risk are 116 g, 825, 11368 rad/s2, 37 kW and 162 g, 1442, 18775 rad/s2, 68 kW, respectively, and the predicted values of 50% probability of skull fracture is 135 g. The knowledge from this study could be a prerequisite for developing guidelines to improve pedestrian safety.

AVAILABILITY OF AIS BINARY DATA TRANSMISSION BASED ON DYNAMIC MEASUREMENTS PERFORMED ON THE SOUTHERN BALTIC AND THE DANISH STRAITS

ABSTRACT The problem of determining coordinates for the requirements of maritime navigation, considered only in terms of measurement error, seems to be solved on a global scale. In view of the above, the operational characteristics of radio navigation systems such as availability are equally important. This paper analyses the problem of AIS binary transmission availability. An attempt was made to assess the availability of the AIS service transmission channel based on dynamic measurements. For this purpose, the theory of Markov processes defined on a discrete state space was applied. The Criterion of state system availability was adopted, stochastic matrix of probabilities of transitions between the states of the availability and accessibility of states limit the probability of AIS. In this paper, the author proposed a model for the assessment of AIS Service availability. To meet the objective of the research, recorded data derived from the Southern Baltic and Danish Straits Base Stations were used.

Choice-Behavior and Distribution of Reinforcement among Response-Alternatives

According to the statistical associative model frequently applied to modified verbal-conditioning,1 each reinforcement of one of the k-possible responses results in a specifiable change in the probability of alternative Al. That is, there is added to the existing probability (Pi) and increment 0 (1 P), if Ai is reinforced, or a decrement, -OPi, if a response other than Ai is reinforced. This version of statistical associative theory, when applied to a situation in which there are more than two responses, incorporates the simplifying assumption that these changes depend only upon the probability of Ai and are invariant with the distribution of the remaining probability among the alternative responses. In contrast to this formulation, it may be proposed that in a situation involving more than two possible responses, the size of the decrement in the probability of Ai may depend upon which of the other alternatives is reinforced. Likewise, the incremental effects of a reinforcement of Ai may depend upon the distribution of values of the alternative responses. Such a position is suggested within the context of Hull-Spence theory when it is assumed that the probability of a given response is a function of the probability that the momentary strength of that response is greater than the momentary strength of any one of the alternatives.2 According to this view, concentrating reinforcements in order to build up a single strong alternative should be more effective in reducing the probability of Ai than distributing those reinforcements among several weaker alternatives. Two studies which have questioned the adequacy of the statistical associative model might be interpreted as supporting the latter suggestion. Both Gardner, and Cotton and Rechtshoffen have found that the asymptotic frequency of the most often reinforced response is greater if the