Browsing by Author "Chen, Jing"
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Item Boring But Demanding: Using Secondary Tasks to Counter the Driver Vigilance Decrement for Partially Automated Driving(Sage, 2024) Mishler, Scott; Chen, JingObjective We investigated secondary–task–based countermeasures to the vigilance decrement during a simulated partially automated driving (PAD) task, with the goal of understanding the underlying mechanism of the vigilance decrement and maintaining driver vigilance in PAD. Background Partial driving automation requires a human driver to monitor the roadway, but humans are notoriously bad at monitoring tasks over long periods of time, demonstrating the vigilance decrement in such tasks. The overload explanations of the vigilance decrement predict the decrement to be worse with added secondary tasks due to increased task demands and depleted attentional resources, whereas the underload explanations predict the vigilance decrement to be alleviated with secondary tasks due to increased task engagement. Method Participants watched a driving video simulating PAD and were required to identify hazardous vehicles throughout the 45-min drive. A total of 117 participants were assigned to three different vigilance-intervention conditions including a driving-related secondary task (DR) condition, a non-driving-related secondary task (NDR) condition, and a control condition with no secondary tasks. Results Overall, the vigilance decrement was shown over time, reflected in increased response times, reduced hazard detection rates, reduced response sensitivity, shifted response criterion, and subjective reports on task-induced stress. Compared to the DR and the control conditions, the NDR displayed a mitigated vigilance decrement. Conclusion This study provided convergent evidence for both resource depletion and disengagement as sources of the vigilance decrement. Application The practical implication is that infrequent and intermittent breaks using a non-driving related task may help alleviate the vigilance decrement in PAD systems.Item Effect of automation failure type on trust development in driving automation systems(Elsevier, 2023) Mishler, Scott; Chen, JingThe performance of a driving automation system (DAS) can influence the human drivers' trust in the system. This driving-simulator study examined how different types of DAS failures affected drivers' trust. The automation-failure type (no-failure, takeover-request, system-malfunction) was manipulated among 122 participants, when a critical hazard event occurred. The dependent measures included participants’ trust ratings after each of seven drives and their takeover performance following the hazard. Results showed that trust improved before any automation failure occurred, demonstrating proper trust calibration toward the errorless system. In the takeover-request and system-malfunction conditions, trust decreased similarly in response to the automation failures, although the takeover-request condition had better takeover performance. For the drives after the automation failure, trust was gradually repaired but did not recover to the original level. This study demonstrated how trust develops and responds to DAS failures, informing future research for trust repair interventions in designing DASs.Item Electrical and switching characteristics of lithium niobate thin films(1996) Chen, Jing; Rabson, Thomas A.C-V and I-V measurements combined with pulse application were employed to study the electrical characteristics of lithium niobate thin film samples. Though the C-V measurements showed some classical features, a lithium drifted n-i-p junction model was postulated to explain the low nominal dielectric constant in C-V characteristics. The I-V characteristics were analyzed and the field dependence was determined to be Frenkel-Poole emission at low field and possibly Fowler-Nordheim at high field. A four-pulse dual-polarity pulse train was then used to study the switching kinetics of these thin films. The resulting transient current was captured and unstable switching was found in some samples. The polarization reversal was found to be dominated by forward domain growth with virtually no sideways motion. Finally, some important time constants such as nucleation time and domain wall growth time were determined and analyzed.Item Free energy landscape for the binding process of Huperzine A to acetylcholinesterase(National Academy of Sciences, 2012) Bai, Fang; Xu, Yechun; Chen, Jing; Liu, Qiufeng; Gu, Junfeng; Wang, Xicheng; Ma, Jianpeng; Li, Honglin; Onuchic, José N.; Jiang, Hualiang; Center for Theoretical Biological PhysicsDrug-target residence time (t = 1/koff, where koff is the dissociation rate constant) has become an important index in discovering betteror best-in-class drugs. However, little effort has been dedicated to developing computational methods that can accurately predict this kinetic parameter or related parameters, koff and activation free energy of dissociation (ΔG≠ off). In this paper, energy landscape theory that has been developed to understand protein folding and function is extended to develop a generally applicable computational framework that is able to construct a complete ligand-target binding free energy landscape. This enables both the binding affinity and the binding kinetics to be accurately estimated.We applied this method to simulate the binding event of the anti-Alzheimer’s disease drug (−)−Huperzine A to its target acetylcholinesterase (AChE). The computational results are in excellent agreement with our concurrent experimental measurements. All of the predicted values of binding free energy and activation free energies of association and dissociation deviate from the experimental data only by less than 1 kcal/ mol. The method also provides atomic resolution information for the (−)−Huperzine A binding pathway, which may be useful in designing more potent AChE inhibitors. We expect thismethodology to be widely applicable to drug discovery and development.Item The Simon Effect Asymmetry for Left- and Right-Dominant Persons(Ubiquity Press, 2023) Proctor, Robert W.; Zhong, Qi; Chen, JingWhen participants respond to a task-relevant stimulus attribute by pressing a left or right key with the respective index finger, reaction time is shorter if task-irrelevant left-right stimulus location corresponds to that of the response key than if it does not. For right-handers, this Simon effect is larger for right-located than left-located stimuli; for left-handers this Simon-effect asymmetry is reversed. A similar asymmetry has been found for right-footers pressing pedals with their feet. For analyses that separate stimulus- and response-location factors, these asymmetries appear as a main effect of response location, with responses being faster with the dominant effector. If the Simon-effect asymmetry is strictly a function of effector dominance, it should reverse for left-footers responding with their feet. In Experiment 1, left-dominant persons showed faster responses with the left than right hand but with the right than left foot, a finding consistent with prior research on tapping actions. Right-dominant persons also showed the right-foot asymmetry but, unexpectedly, not the typical asymmetry with hand responses. To evaluate whether hand-presses yield results distinct from finger-presses, in Experiment 2 participants performed the Simon task with finger-presses and hand-presses. The opposing asymmetries for right- and left-dominant persons were evident for both response modes. Our results are consistent with the view that the Simon effect asymmetry is primarily due to differences in effector efficiency, usually but not always favoring the dominant effector.