Military teams - A demand for resilience.

BACKGROUND: The Royal Norwegian Naval Academy (RNoNA) has an interest in enhancing military teams' knowledge, skills and abilities to deal with complex situations and environments. OBJECTIVE: The objective is to document the need for resilience in military teams and to expand the understanding of how such behavior can be meaningfully instilled through team training interventions. METHOD: Norwegian military subject matter experts (SMEs) assessed the performance of military teams participating in complex military training exercises. Eight cadet teams at the RNoNA were assessed during two separate 4-hour simulator training exercises and a 48-hour live training exercise. RESULTS: Positive Spearman rank correlation coefficients between resilience assessments in the simulator training exercises and the live training exercise were strongest when the simulator scenario emphasized resilience factors inherent in the live exercise, and weakest when the simulator scenario did not facilitate the task demands in the live exercise. CONCLUSION: The study showed that resilience assessed in teams during simulator training exercises predicted their resilient behavior in a subsequent live training exercise and that the proper design of scenario-based simulator training can realistically and effectively represent resilience stressors found in live operations.

Assessing contextual factors that influence acceptance of pedestrian alerts by a night vision system.

OBJECTIVE: We investigated five contextual variables that we hypothesized would influence driver acceptance of alerts to pedestrians issued by a night vision active safety system to inform the specification of the system's alerting strategies. BACKGROUND: Driver acceptance of automotive active safety systems is a key factor to promote their use and implies a need to assess factors influencing driver acceptance. METHOD: In a field operational test, 10 drivers drove instrumented vehicles equipped with a preproduction night vision system with pedestrian detection software. In a follow-up experiment, the 10 drivers and 25 additional volunteers without experience with the system watched 57 clips with pedestrian encounters gathered during the field operational test. They rated the acceptance of an alert to each pedestrian encounter. RESULTS: Levels of rating concordance were significant between drivers who experienced the encounters and participants who did not. Two contextual variables, pedestrian location and motion, were found to influence ratings. Alerts were more accepted when pedestrians were close to or moving toward the vehicle's path. CONCLUSION: The study demonstrates the utility of using subjective driver acceptance ratings to inform the design of active safety systems and to leverage expensive field operational test data within the confines of the laboratory. APPLICATION: The design of alerting strategies for active safety systems needs to heed the driver's contextual sensitivity to issued alerts.

Driver acceptance of false alarms to simulated encroachment.

OBJECTIVE: We investigated driver acceptance of alerts to left-turn encroachment incidents that do not produce a crash. If an event that produces a crash is the criterion for a "true" alert, all the alerts we studied are technically false alarms. Our aim was to inform the design of intersection-assist active safety systems. BACKGROUND: The premise of this study is that it may be possible to overcome driver resistance to alerts that are false alarms by designing systems to issue alerts when and only when drivers would expect and accept them. METHOD: Participants were passengers in a driving simulator that presented left-turn encroachment incidents. Participant point of view, the direction of encroachment, and postencroachment time (PET) were manipulated to produce 36 near-crash incidents. After viewing each incident, the participant rated the relative acceptability of a hypothetical alert to it. RESULTS: Repeated-measures ANOVA and logistic regression indicate that acceptability varies inversely with PET. At PET intervals less than 2.2 s, driver point of view and encroachment direction interact. At PET intervals more than 2.2 s, alerts to lateral encroachments are more acceptable than alerts to oncoming encroachments. CONCLUSION: Driver acceptance of alerts by active safety systems will be sensitive to context. APPLICATION: This study demonstrates the utility of eliciting subjective criteria to inform system design to match driver (user) expectations. Intersection-assist active safety systems will need to be designed to adapt to the interaction of driver point of view, the direction of encroachment, and PET.

Pedestrian injury mitigation by autonomous braking.

The objective of this study was to calculate the potential effectiveness of a pedestrian injury mitigation system that autonomously brakes the car prior to impact. The effectiveness was measured by the reduction of fatally and severely injured pedestrians. The database from the German In-Depth Accident Study (GIDAS) was queried for pedestrians hit by the front of cars from 1999 to 2007. Case by case information on vehicle and pedestrian velocities and trajectories were analysed to estimate the field of view needed for a vehicle-based sensor to detect the pedestrians one second prior to the crash. The pre-impact braking system was assumed to activate the brakes one second prior to crash and to provide a braking deceleration up to the limit of the road surface conditions, but never to exceed 0.6 g. New impact speeds were then calculated for pedestrians that would have been detected by the sensor. These calculations assumed that all pedestrians who were within a given field of view but not obstructed by surrounding objects would be detected. The changes in fatality and severe injury risks were quantified using risk curves derived by logistic regression of the accident data. Summing the risks for all pedestrians, relationships between mitigation effectiveness, sensor field of view, braking initiation time, and deceleration were established. The study documents that the effectiveness at reducing fatally (severely) injured pedestrians in frontal collisions with cars reached 40% (27%) at a field of view of 40 degrees. Increasing the field of view further led to only marginal improvements in effectiveness.

The impact of the certainty context on the process of choice.

In this study we examine how the introduction of a reference lottery with nonrandom outcomes alters the way in which choices among pairs of lotteries are made, even if it does not alter the choices. We use different domains (some of the lotteries produce gains, other losses) and different contexts (one member of the pair, the reference lottery, may be either risky or certain). In our experiment, the change from gain to loss domain affects choices: subjects are risk averse in the gain domain, but not in the loss domain. On the contrary, the context effect of the certain lottery does not affect choices. However, the introduction of the certainty reference lottery affects two behavioral variables, response time and brain activation, in a dramatic way. This result suggests that the certainty lottery promotes a different process through which preferences are revealed, even if the differences among lotteries may not be large enough to induce different choices.