36 research outputs found
AMoDSim: An Efficient and Modular Simulation Framework for Autonomous Mobility on Demand
Urban transportation of next decade is expected to be disrupted by Autonomous
Mobility on Demand (AMoD): AMoD providers will collect ride requests from users
and will dispatch a fleet of autonomous vehicles to satisfy requests in the
most efficient way. Differently from current ride sharing systems, in which
driver behavior has a clear impact on the system, AMoD systems will be
exclusively determined by the dispatching logic. As a consequence, a recent
interest in the Operations Research and Computer Science communities has
focused on this control logic. The new propositions and methodologies are
generally evaluated via simulation. Unfortunately, there is no simulation
platform that has emerged as reference, with the consequence that each author
uses her own custom-made simulator, applicable only in her specific study, with
no aim of generalization and without public release. This slows down the
progress in the area as researchers cannot build on each other's work and
cannot share, reproduce and verify the results. The goal of this paper is to
present AMoDSim, an open-source simulation platform aimed to fill this gap and
accelerate research in future ride sharing systems
New Behaviours and Digitalisation for Sustainable Mobility, Mobility as a Service (MaaS)
This chapter will deal with changes in the behaviour of city dwellers and digital technologies which can facilitate such behaviour. Mass transportation must certainly remain the backbone of local public transport, both in terms of travel within cities and for that towards cities. However, this chapter will focus on the transformations which are taking place and which will have to be favoured in order to reduce and optimise private transport, a real scourge in large towns and cities. The final part of the chapter covers the concept of mobility as a service, being the evolution of the concept of ownership towards that of service
The recognition of diagnosable psychiatric disorders in suicide cases’ last medical contacts.
This chapter is a collection of techniques, warnings, facts and ideas that are sometimes regarded as theoretical curiosities in high-energy physics but have important consequences in condensed matter physics. In particular, we describe theories that have the property of having finite but undetermined radiative corrections that also happen to describe topological semi-metallic phases in condensed matter. In the process, we describe typical methods in high-energy physics that illustrate the working principles to describe a given phase of matter and its response to external fields
Topological nodal-line fermions in spin-orbit metal PbTaSe2
[[abstract]]Topological semimetals can support one-dimensional Fermi lines or zero-dimensional Weyl points in momentum space, where the valence and conduction bands touch. While the degeneracy points in Weyl semimetals are robust against any perturbation that preserves translational symmetry, nodal lines require protection by additional crystalline symmetries such as mirror reflection. Here we report, based on a systematic theoretical study and a detailed experimental characterization, the existence of topological nodal-line states in the non-centrosymmetric compound PbTaSe2 with strong spin-orbit coupling. Remarkably, the spin-orbit nodal lines in PbTaSe2 are not only protected by the reflection symmetry but also characterized by an integer topological invariant. Our detailed angle-resolved photoemission measurements, first-principles simulations and theoretical topological analysis illustrate the physical mechanism underlying the formation of the topological nodal-line states and associated surface states for the first time, thus paving the way towards exploring the exotic properties of the topological nodal-line fermions in condensed matter systems.[[notice]]補正完