The Lord of the Ring Road: A Review and Evaluation of Autonomous Control Policies for Traffic in a Ring Road

This study focuses on the comprehensive investigation of stop-and-go waves appearing in closed-circuit ring road traffic wherein we evaluate various longitudinal dynamical models for vehicles. It is known that the behavior of human-driven vehicles, with other traffic elements such as density held constant, could stimulate stop-and-go waves, which do not dissipate on the circuit ring road. Stop-and-go waves can be dissipated by adding automated vehicles (AVs) to the ring. Thorough investigations of the performance of AV longitudinal control algorithms were carried out in Flow, which is an integrated platform for reinforcement learning on traffic control. Ten AV algorithms presented in the literature are evaluated. For each AV algorithm, experiments are carried out by varying distributions and penetration rates of AVs. Two different distributions of AVs are studied. For the first distribution scenario, AVs are placed consecutively. Penetration rates are varied from 1 AV (5%) to all AVs (100%). For the second distribution scenario, AVs are placed with even distribution of human-driven vehicles in between any two AVs. In this scenario, penetration rates are varied from 2 AVs (10%) to 11 AVs (50%). Multiple runs (10 runs) are simulated to average out the randomness in the results. From more than 3,000 simulation experiments, we investigated how AV algorithms perform differently with varying distributions and penetration rates while all AV algorithms remained fixed under all distributions and penetration rates. Time to stabilize, maximum headway, vehicle miles traveled, and fuel economy are used to evaluate their performance. Using these metrics, we find that the traffic condition improvement is not necessarily dependent on the distribution for most of the AV controllers, particularly when no cooperation among AVs is considered. Traffic condition is generally improved with a higher AV penetration rate with only one of the AV algorithms showing a contrary trend. Among all AV algorithms in this study, the reinforcement learning controller shows the most consistent improvement under all distributions and penetration rates.

Automated Conflict Management Framework Development for Autonomous Aerial and Ground Vehicles

The number of aerial- and ground-based unmanned vehicles and operations is expected to significantly expand in the near future. While aviation traditionally has an excellent safety record in managing conflicts, the current approaches will not be able to provide safe and efficient operations in the future. This paper presents the development of a novel framework integrating autonomous aerial and ground vehicles to facilitate short- and mid-term tactical conflict management. The methodology presents the development of a modular web service framework to develop new conflict management algorithms. This new framework is aimed at managing urban and peri-urban traffic of unmanned ground vehicles and assisting the introduction of urban air mobility into the same framework. A set of high-level system requirements is defined. The incremental development of two versions of the system prototype is presented. The discussions highlight the lessons learnt while implementing and testing the conflict management system and the introduced version of the stop-and-go resolution algorithm and defines the identified future development directions. Operation of the system was successfully demonstrated using real hardware. The developed framework implements short- and mid-term conflict management methodologies in a safe, resource efficient and scalable manner and can be used for the further development and the evaluation of various methods integrating aerial- and ground-based autonomous vehicles.

Spatiotemporal Stop-and-go Dynamics of the Mitochondrial TOM Core Complex Correlates With Three-state Channel Activity

Single-molecule studies can reveal phenomena that remain hidden in ensemble measurements. Here, we show the correlation between lateral protein diffusion and channel activity of the general protein import pore of mitochondria (TOM-CC) in membranes resting on ultrathin hydrogel films. Using electrode-free optical recordings of ion flux, we find that TOM-CC switches reversibly between three states of ion permeability associated with protein diffusion. Freely diffusing TOM-CC molecules are observed in a high permeability state, while non-moving molecules are in an intermediate and a low permeability state. We explain this behavior by the mechanical binding of the two protruding Tom22 subunits to the hydrogel and a concomitant combinatorial opening and closing of the two β-barrel pores of TOM-CC. TOM-CC could thus be the first β-barrel protein channel to exhibit membrane state-dependent mechanosensitive properties.

Adherence and sustainability of interventions informing optimal control against the COVID-19 pandemic

Background After one year of stop-and-go COVID-19 mitigation, in the spring of 2021 European countries still experienced sustained viral circulation due to the Alpha variant. As the prospect of entering a new pandemic phase through vaccination was drawing closer, a key challenge remained on how to balance the efficacy of long-lasting interventions and their impact on the quality of life. Methods Focusing on the third wave in France during spring 2021, we simulate intervention scenarios of varying intensity and duration, with potential waning of adherence over time, based on past mobility data and modeling estimates. We identify optimal strategies by balancing efficacy of interventions with a data-driven “distress” index, integrating intensity and duration of social distancing. Results We show that moderate interventions would require a much longer time to achieve the same result as high intensity lockdowns, with the additional risk of deteriorating control as adherence wanes. Shorter strict lockdowns are largely more effective than longer moderate lockdowns, for similar intermediate distress and infringement on individual freedom. Conclusions Our study shows that favoring milder interventions over more stringent short approaches on the basis of perceived acceptability could be detrimental in the long term, especially with waning adherence.

Konfigurasi baterai lead acid pada sistem pengaturan motor BLDC untuk aplikasi mobil listrik

Kendaraan listrik merupakan salah satu solusi teknologi yang saat ini dikembangkan untuk mengatasi permasalahan lingkungan akibat polusi udara. Jenis kendaraan ini menggunakan baterai sebagai sumber daya penggeraknya. Umumnya kendaraan listrik menggunakan baterai tunggal yang memiliki daya yang besar, seperti sepeda listrik. Namun, untuk mobil listrik sebuah baterai saja tidak mencukupi sebab dibutuhkan daya yang lebih besar dan siklus hidup yang lebih panjang. Oleh karena itu, perlu digunakan beberapa baterai sekaligus yang disusun dengan konfigurasi tertentu. Penelitian ini bertujuan melakukan studi terhadap konfigurasi baterai lead acid pada sistem pengaturan motor brushless direct current (BLDC) yang digunakan sebagai penggerak mobil listrik. Studi dilakukan secara eksperimen perangkat keras dengan membandingkan konfigurasi baterai secara paralel dan seri. Kemudian setiap konfigurasi diuji untuk beberapa jenis skenario perjalanan kendaraan untuk melihat performansinya. Hasil pengujian secara eksperimen menunjukkan bahwa baterai dengan konfigurasi paralel lebih efektif digunakan untuk skenario perjalanan dalam kota yang memiliki karakteristik stop and go, dengan daya maksimal yang dapat dikeluarkan oleh baterai adalah 7,68 W, sedangkan baterai dengan konfigurasi seri dapat digunakan untuk perjalanan yang lebih jauh dengan kondisi lintasan lurus dan datar, dengan daya maksimal 4,32 W.

Konfigurasi baterai lead acid pada sistem pengaturan motor BLDC untuk aplikasi mobil listrik

Kendaraan listrik merupakan salah satu solusi teknologi yang saat ini dikembangkan untuk mengatasi permasalahan lingkungan akibat polusi udara. Jenis kendaraan ini menggunakan baterai sebagai sumber daya penggeraknya. Umumnya kendaraan listrik menggunakan baterai tunggal yang memiliki daya yang besar, seperti sepeda listrik. Namun, untuk mobil listrik sebuah baterai saja tidak mencukupi sebab dibutuhkan daya yang lebih besar dan siklus hidup yang lebih panjang. Oleh karena itu, perlu digunakan beberapa baterai sekaligus yang disusun dengan konfigurasi tertentu. Penelitian ini bertujuan melakukan studi terhadap konfigurasi baterai lead acid pada sistem pengaturan motor brushless direct current (BLDC) yang digunakan sebagai penggerak mobil listrik. Studi dilakukan secara eksperimen perangkat keras dengan membandingkan konfigurasi baterai secara paralel dan seri. Kemudian setiap konfigurasi diuji untuk beberapa jenis skenario perjalanan kendaraan untuk melihat performansinya. Hasil pengujian secara eksperimen menunjukkan bahwa baterai dengan konfigurasi paralel lebih efektif digunakan untuk skenario perjalanan dalam kota yang memiliki karakteristik stop and go, dengan daya maksimal yang dapat dikeluarkan oleh baterai adalah 7,68 W, sedangkan baterai dengan konfigurasi seri dapat digunakan untuk perjalanan yang lebih jauh dengan kondisi lintasan lurus dan datar, dengan daya maksimal 4,32 W.

Correlation of mitochondrial TOM core complex stop-and-go and open-closed channel dynamics

The role of lateral diffusion of proteins in the membrane in the context of function has not been examined extensively. Here, we explore the relationship between protein lateral diffusion and channel activity of the general protein import pore of mitochondria (TOM-CC). Optical ion flux sensing through single TOM-CC molecules shows that TOM-CC can occupy three ion permeability states. Whereas freely diffusing TOM-CC molecules are preferentially found in a high permeability state, physical tethering to an agarose support causes the channels to transition to intermediate and low permeability states. This data shows that combinatorial opening and closing of the two pores of TOM-CC correlates with lateral protein diffusion in the membrane plane, and that the complex has mechanosensitive-like properties. This is the first demonstration of β-barrel protein mechanosensitivity, and has direct conceptual consequences for the understanding of the process of mitochondrial protein import. Our approach provides a novel tool to simultaneously study the interplay of membrane protein diffusion and channel dynamics.