Cooperative Intersection with Misperception in Partially Connected and Automated Traffic

The emerging connected and automated vehicle (CAV) has the potential to improve traffic efficiency and safety. With the cooperation between vehicles and intersection, CAVs can adjust speed and form platoons to pass the intersection faster. However, perceptual errors may occur due to external conditions of vehicle sensors. Meanwhile, CAVs and conventional vehicles will coexist in the near future and imprecise perception needs to be tolerated in exchange for mobility. In this paper, we present a simulation model to capture the effect of vehicle perceptual error and time headway to the traffic performance at cooperative intersection, where the intelligent driver model (IDM) is extended by the Ornstein–Uhlenbeck process to describe the perceptual error dynamically. Then, we introduce the longitudinal control model to determine vehicle dynamics and role switching to form platoons and reduce frequent deceleration. Furthermore, to realize accurate perception and improve safety, we propose a data fusion scheme in which the Differential Global Positioning system (DGPS) data interpolates sensor data by the Kalman filter. Finally, a comprehensive study is presented on how the perceptual error and time headway affect crash, energy consumption as well as congestion at cooperative intersections in partially connected and automated traffic. The simulation results show the trade-off between the traffic efficiency and safety for which the number of accidents is reduced with larger vehicle intervals, but excessive time headway may result in low traffic efficiency and energy conversion. In addition, compared with an on-board sensor independently perception scheme, our proposed data fusion scheme improves the overall traffic flow, congestion time, and passenger comfort as well as energy efficiency under various CAV penetration rates.

Even if it might not be true, evidence cannot be false

Wordly internalists claim that while internal duplicates always share the same evidence, our evidence includes non-trivial propositions about our environment. It follows that some evidence is false. Worldly internalism is thought to provide a more satisfying answer to scepticism than classical internalist views that deny that these propositions about our environment might belong to our evidence and to provide a generally more attractive account of rationality and reasons for belief. We argue that worldly internalism faces serious difficulties and that its apparent advantages are illusory. First, it cannot adequately handle some not terribly strange cases of perceptual error. Second, it cannot explain why one should plan to use their evidence to update their beliefs. The second issue allows us to explain why cases of misplaced certainty do not require us to introduce false evidence into our views and that why the alleged advantage of worldly internalism in resisting sceptical pressures is illusory.

The Back Alleys and Dark Corners of Abdomen and Pelvis Computed Tomography: The Most Frequent Sites of Missed Findings in the Multiplanar Era

Objectives: Radiologists reading multiplanar abdominal/pelvic computed tomography (CT) are vulnerable to oversight of specific anatomic areas, leading to perceptual errors (misses). The aims of this study are to identify common sites of major perceptual error at our institution and then to put these in context with earlier studies to produce a comprehensive overview. Material and Methods: We reviewed our quality assurance database over an 8-year period for cases of major perceptual error on CT examinations of the abdomen and pelvis. A major perceptual error was defined as a missed finding that had altered management in a way potentially detrimental to the patient. Record was made of patient age, gender, study indication, study priority (stat/routine), and use of IV and/or oral contrast. Anatomic locations were subdivided as lung bases, liver, pancreas, kidneys, spleen, mesentery, peritoneum, retroperitoneum, small bowel, colon, appendix, vasculature, body wall, and bones. Results: A total of 216 missed findings were identified in 201 patients. The most common indication for the study was cancer follow-up (71%) followed by infection (11%) and abdominal pain (6%). The most common anatomic regions of error were the liver (15%), peritoneum (10%), body wall (9%), retroperitoneum (8%), and mesentery (6%). Data from other studies were reorganized into congruent categories for comparison. Conclusion: This study demonstrates that the most common sites of significant missed findings on multiplanar abdominal/pelvic CT included the mesentery, peritoneum, body wall, bowel, vasculature, and the liver in the arterial phase. Data from other similar studies were reorganized into congruent categories to provide a comprehensive overview.

Epistemology

This chapter presents Epicurus’s theory of knowledge as a response to the epistemological pessimism of Democritus. The first section discusses the three “criteria of truth”—sense impressions, preconceptions, and the feelings of pleasure and pain; and also Epicurus’s account of perceptual error, by which he tried to show that the senses do after all offer true and consistent, if sometimes fragmentary, information. The second section deals with Epicurus’s scientific method, i.e. the confirmation and refutation of beliefs or theoretical hypotheses. In a final section, I briefly discuss the role of the feelings as criteria in ethics, and the kind of reasoning Epicurus used to call ἐπιλογισμός.

Teleoperation of an ankle-foot prosthesis with a wrist exoskeleton

ObjectiveWe aimed to develop a system for people with amputation that non-invasively restores missing control and sensory information for an ankle-foot prosthesis.MethodsIn our approach, a wrist exoskeleton allows people with amputation to control and receive feedback from their prosthetic ankle via teleoperation. We implemented two control schemes: position control with haptic feedback of ankle torque at the wrist; and torque control that allows the user to modify a baseline torque profile by moving their wrist against a virtual spring. We measured tracking error and frequency response for the ankle-foot prosthesis and the wrist exoskeleton. To demonstrate feasibility and evaluate system performance, we conducted an experiment in which one participant with a transtibial amputation tracked desired wrist trajectories during walking, while we measured wrist and ankle response.ResultsBenchtop testing demonstrated that for relevant walking frequencies, system error was below human perceptual error. During the walking experiment, the participant was able to voluntarily follow different wrist trajectories with an average RMS error of 1.55° after training. The ankle was also able to track desired trajectories below human perceptual error for both position control (RMSE = 0.8°) and torque control (RMSE = 8.4%).ConclusionWe present a system that allows a user with amputation to control an ankle-foot prosthesis and receive feedback about its state using a wrist exoskeleton, with accuracy comparable to biological neuromotor control.SignificanceThis bilateral teleoperation system enables novel prosthesis control and feedback strategies that could improve prosthesis control and aid motor learning.

150 years of research on Vierordt’s law - Fechner’s fault?

Abstract150 years ago, the physiologist Karl Vierordt discovered one type of systematic errors in time perception – an overestimation of long durations and underestimation of short durations, now known as Vierordt’s law. Here we review the original study in its historical context and ask whether Vierordt’s law is a result of an unnatural experimental randomization protocol. Using iterative Bayesian updating, we simulated the original results with astonishing accuracy. To validate whether the experimental protocol matters, we compared duration reproduction from two sequences with the same sampled distribution and found that trial-wise variation determines the reproduction error. We conclude that Vierordt’s law is caused by an unnatural yet widely used experimental protocol.One Sentence SummaryProbabilistic modeling reveals that a classical perceptual error - Vierordt’s law - is caused by an unnatural yet widely used experimental protocol.

Direct Realism and Illusion

The supposed problem of perceptual error, including illusion and hallucination, has led most theories of perception to deny formulations of direct realism. The standard response to this apparent problem adopts the mistaken presupposition that perception is indeed liable to error. However, the prevailing conditions of observation are themselves elements of perceptual representation, functioning in the manner of predicate modifiers. They ensure that the predicates applied in perceptual representations do indeed correctly attribute properties that perceived physical objects actually instantiate. Thus, perceptual representations are immune to misrepresentation of the sort misguidedly supposed by the spurious problem of perceptual misrepresentation. Granted the possibility that perceptual attribution admits of predicate modification, it is quite possible that perceptual experience permits both rudimentary and sophisticated conceptualization. Moreover, such treatment of perceptual predication rewards by providing an account of aspect alteration exemplified by perception of ambiguous stimuli.