Approximately orchestrated routing and transportation analyzer: City-scale traffic simulation and control schemes

Along with other intelligent traffi c control schemes, autonomous vehicles present new opportunities for addressing traffi c congestion. Traffi c simulators enable researchers to explore these possibilities be- fore such vehicles are widespread. This thesis describes a new open source, agent-based simulator: the Approximately Orchestrated Routing and Transportation Analyzer, or AORTA. AORTA is designed to provide reasonably realistic simulation of any city in the world with zero con figuration, to run on cheap machines, and with an emphasis on easy use and simple code. Experiments described in this thesis can be set up on a new city in about five minutes. Two applications are built on AORTA by creating new intersection control policies and specifying new strategies for routing drivers. The first application, intersection auctions, allows humans to instruct their autonomous vehicle to bid on their behalf at intersections, granting them entry before other drivers who desire conflicting movements. The second, externality pricing, learns the travel time of a variety of di fferent routes and defi nes a localized notion of cost imposed on other drivers by following the route. This information is used to tax drivers who choose to improve their own trip by inconveniencing others. These two systems demonstrate AORTA's utility for simulating control of the traffi c of the near future.http://www.aorta-traffic.orgComputer Science

Synthetic Population Catalyst : a micro-simulated population of England with circadian activities

Funding: This work was supported by Wave 1 of The UKRI Strategic Priorities Fund under the EPSRC Grant EP/W006022/1, particularly the “Ecosystem of Digital Twin” and “Shocks and Resilience” themes within that grant & The Alan Turing Institute.The Synthetic Population Catalyst (SPC) is an open-source tool for the simulation of populations. Building on previous efforts, synthetic populations can be created for any area in England, from a small geographical unit to the entire country, and linked to geolocalised daily activities. In contrast to most transport models, the output is focussed on the population itself and the way people socially interact together, rather than on a precise modelling of the volume of transport trips from one area to another. SPC is therefore particularly well suited, for example, to study the spread of a pandemic within a population. Other applications include identifying segregation patterns and potential causes of inequality of opportunity amongst individuals. It is fast, thanks to its Rust codebase. The outputs for each lieutenancy area in England are directly available without having to run the code.PostprintPeer reviewe

Search for dark matter produced in association with bottom or top quarks in √s = 13 TeV pp collisions with the ATLAS detector

A search for weakly interacting massive particle dark matter produced in association with bottom or top quarks is presented. Final states containing third-generation quarks and miss- ing transverse momentum are considered. The analysis uses 36.1 fb−1 of proton–proton collision data recorded by the ATLAS experiment at √s = 13 TeV in 2015 and 2016. No significant excess of events above the estimated backgrounds is observed. The results are in- terpreted in the framework of simplified models of spin-0 dark-matter mediators. For colour- neutral spin-0 mediators produced in association with top quarks and decaying into a pair of dark-matter particles, mediator masses below 50 GeV are excluded assuming a dark-matter candidate mass of 1 GeV and unitary couplings. For scalar and pseudoscalar mediators produced in association with bottom quarks, the search sets limits on the production cross- section of 300 times the predicted rate for mediators with masses between 10 and 50 GeV and assuming a dark-matter mass of 1 GeV and unitary coupling. Constraints on colour- charged scalar simplified models are also presented. Assuming a dark-matter particle mass of 35 GeV, mediator particles with mass below 1.1 TeV are excluded for couplings yielding a dark-matter relic density consistent with measurements