3 research outputs found
Real-time Control of Electric Autonomous Mobility-on-Demand Systems via Graph Reinforcement Learning
Operators of Electric Autonomous Mobility-on-Demand (E-AMoD) fleets need to
make several real-time decisions such as matching available cars to ride
requests, rebalancing idle cars to areas of high demand, and charging vehicles
to ensure sufficient range. While this problem can be posed as a linear program
that optimizes flows over a space-charge-time graph, the size of the resulting
optimization problem does not allow for real-time implementation in realistic
settings. In this work, we present the E-AMoD control problem through the lens
of reinforcement learning and propose a graph network-based framework to
achieve drastically improved scalability and superior performance over
heuristics. Specifically, we adopt a bi-level formulation where we (1) leverage
a graph network-based RL agent to specify a desired next state in the
space-charge graph, and (2) solve more tractable linear programs to best
achieve the desired state while ensuring feasibility. Experiments using
real-world data from San Francisco and New York City show that our approach
achieves up to 89% of the profits of the theoretically-optimal solution while
achieving more than a 100x speedup in computational time. Furthermore, our
approach outperforms the best domain-specific heuristics with comparable
runtimes, with an increase in profits by up to 3x. Finally, we highlight
promising zero-shot transfer capabilities of our learned policy on tasks such
as inter-city generalization and service area expansion, thus showing the
utility, scalability, and flexibility of our framework.Comment: 9 page
A randomised multicentre trial of acupuncture in patients with seasonal allergic rhinitis – trial intervention including physician and treatment characteristics
Background In a large randomised trial in patients with seasonal allergic rhinitis (SAR), acupuncture was superior compared to sham acupuncture and rescue medication. The aim of this paper is to describe the characteristics of the trial’s participating physicians and to describe the trial intervention in accordance with the STRICTA (Standards for Reporting Interventions in Controlled Trials of Acupuncture) guidelines, to make details of the trial intervention more transparent to researchers and physicians. Methods ACUSAR (ACUpuncture in Seasonal Allergic Rhinitis) was a three-armed, randomised, controlled multicentre trial. 422 SAR patients were randomised to semi-standardised acupuncture plus rescue medication (RM, cetirizine), sham acupuncture plus RM or RM alone. We sent a questionnaire to trial physicians in order to evaluate their characteristics regarding their education about and experience in providing acupuncture. During the trial, acupuncturists were asked to diagnose all of their patients according to Chinese Medicine (CM) as a basis for the semi-standardised, individualized intervention in the acupuncture group. Every acupuncture point used in this trial had to be documented after each session Results Acupuncture was administered in outpatient clinics by 46 (mean age 47 ± 10 years; 24 female/ 22 male) conventionally-trained medical doctors (67% with postgraduate specialization such as internal or family medicine) with additional extensive acupuncture training (median 500 hours (1st quartile 350, 3rd quartile 1000 hours with 73% presenting a B-diploma in acupuncture training (350 hours)) and experience (mean 14 years in practice). The most reported traditional CM diagnosis was ‘wind-cold invading the lung’ (37%) and ‘wind-heat invading the lung’ (37%), followed by ‘lung and spleen qi deficiency’ (9%). The total number of needles used was higher in the acupuncture group compared to the sham acupuncture group (15.7 ± 2.5 vs. 10.0 ± 1.6). Conclusions The trial interventions were provided by well educated and experienced acupuncturists. The different number of needles in both intervention groups could be possibly a reason for the better clinical effect in SAR patients. For future trials it might be more appropriate to ensure that acupuncture and sham acupuncture groups should each be treated by a similar number of needles