Biomedical subjects

A J Masalonis

Publications and source records attributed to A J Masalonis.

3 recordsLinked to original sources

PubMed2000

The immediate effects of glare and electrochromic glare-reducing mirrors in simulated truck driving.

In this experiment 12 experienced truck drivers drove a fixed-base driving simulator for three 8-h sessions under simulated nighttime driving conditions. Sessions included (a) no glare, (b) intermittent glare presented in the exterior rearview mirrors to simulate following vehicles, and (c) intermittent glare with electrochromic glare reduction. The driving task combined vehicle control on straight and curved road segments with detection of pedestrians appearing alongside the road and targets appearing in the rearview mirrors. The presence of glare slowed detection of pedestrians and, to a lesser extent, slowed the detection of targets appearing in mirrors. Glare was also associated with increased lane position variability, reduced speed on curves, and, most consistently, increased steering variability. We found only meager evidence that electrochromic glare reduction improved target detection performance and no evidence that glare reduction improved vehicle control, despite the fact that participants consistently voiced positive preferences for glare reduction. The results will aid decision making that requires incorporation of the benefits of electrochromic glare-reducing mirrors.

Adult↗

PubMed2000

Fuzzy signal detection theory: basic postulates and formulas for analyzing human and machine performance.

Signal detection theory (SDT) assumes a division of objective truths or "states of the world" into the nonoverlapping categories of signal and noise. The definition of a signal in many real settings, however, varies with context and over time. In the terminology of fuzzy logic, a real-world signal has a value that falls in a range between unequivocal presence and unequivocal absence. The definition of a response can also be nonbinary. Accordingly the methods of fuzzy logic can be combined with SDT, yielding fuzzy SDT. We describe the basic postulates of fuzzy SDT and provide formulas for fuzzy analysis of detection performance, based on four steps: (a) selection of mapping functions for signal and response; (b) use of mixed-implication functions to assign degrees of membership in hits, false alarms, misses, and correct rejections; (c) computation of fuzzy hit, false alarm, miss, and correct rejection rates; and (d) computation of fuzzy sensitivity and bias measures. Fuzzy SDT can considerably extend the range and utility of SDT by handling the contextual and temporal variability of most real-world signals. Actual or potential applications of fuzzy SDT include evaluation of the performance of human, machine, and human-machine detectors in real systems.

Fuzzy Logic↗

PubMed1999

Prolonged exposure to glare and driving time: effects on performance in a driving simulator.

Twelve experienced truck drivers drove a fixed-base driving simulator for two 8 h sessions, including: (1) no glare and (2) intermittent glare presented in the exterior rear-view mirrors to simulate headlights from following vehicles. The driving task combined vehicle control on straight and curved road segments with detection of pedestrians appearing alongside the road and targets appearing in the rear-view mirrors. The results provided no evidence to support the hypothesis that prolonged exposure to glare impairs driving performance. However, we found time-related changes in target-detection and critical tracking performance, some of which were consistent with established patterns of diurnal variation. Subjective sleepiness ratings also increased over time. The results were interpreted within a model according to which drivers are able to maintain effective performance at early levels of impairment, thus compensating for increasing feelings of subjective tiredness.

Adult↗