Comparison of two simulation methods for testing of algorithms to detect cyclist and pedestrian accidents in naturalistic data

Naturalistic studies can potentially be used to detect accidents of vulnerable road users and thus overcome the large degree of under-reporting in the official accident records. In this study, simulated cycling and walking accidents were performed by a stuntman and with a crash test dummy to test how they differ from each other and the potential implications of using simulated accidents as an alternative to real accidents. The study consisted of simulations of common accident types for cyclists and pedestrians, such as tripping over a curb or falling of the bike after hitting an obstacle. Motion data in terms of acceleration and rotation as well as the state of the screen (turned on/off) was collected via an Android smartphone to use as indicators for the motion patterns during accidents. The results show that dummy data have a distinct peak at the moment of the fall as a result of not being able to break the fall. As opposed to this, the stuntman arranges himself in a way to reduce the impact when hitting the ground. In real accidents, motion patterns will probably lie in-between these two types

Mobile Application for Naturalistic Walking/Cycling Data Collection

Two smartphone applications were developed with the aim of harvesting insights of vulnerable road user accidents. The apps require a backend database with software tools for generating and managing questionnaires, etc. Such a system was developed using a MySQL database where a user-friendly platform has been developed in CakePHP. The backend system has been successfully developed and been used to handle more than 11,000 participants. The original idea was to monitor VRU via apps to detect when they may have been involved in an accident as pedestrian or cyclist based on the motion patterns from the smartphone’s motion sensors (accelerometer, gyroscope) and collect as much information as possible regarding the accident automatically (e.g. time and location of the accident). If an accident was detected, the road user should receive a questionnaire to provide detailed information of the accident (e.g. road surface conditions, lighting conditions, other road users involved). This app was used by more than 400 participants resulting in a large amount of data

Where Brain, Body and World Collide

The production cross section of electrons from semileptonic decays of beauty hadrons was measured at mid-rapidity (|y| < 0.8) in the transverse momentum range 1 < pt < 8 Gev/c with the ALICE experiment at the CERN LHC in pp collisions at a center of mass energy sqrt{s} = 7 TeV using an integrated luminosity of 2.2 nb^{-1}. Electrons from beauty hadron decays were selected based on the displacement of the decay vertex from the collision vertex. A perturbative QCD calculation agrees with the measurement within uncertainties. The data were extrapolated to the full phase space to determine the total cross section for the production of beauty quark-antiquark pairs

Energy Dependence of the Transverse Momentum Distributions of Charged Particles in pp Collisions Measured by ALICE

Differential cross sections of charged particles in inelastic pp collisions as a function of p_T have been measured at $\sqrt{s}$ = 0.9, 2.76 and 7 TeV at the LHC. The $p_T$ spectra are compared to NLO-pQCD calculations. Though the differential cross section for an individual $\sqrt{s}$ cannot be described by NLO-pQCD, the relative increase of cross section with sqrt(s) is in agreement with NLO-pQCD. Based on these measurements and observations, procedures are discussed to construct pp reference spectra at $\sqrt{s}$ = 2.76 and 5.02 TeV up to $p_T$ = 50 GeV/c as required for the calculation of the nuclear modification factor in nucleus-nucleus and proton-nucleus collisions

Multiplicity dependence of the average transverse momentum in pp, p-Pb, and Pb-Pb collisions at the LHC

The average transverse momentum versus the charged-particle multiplicity $N_{ch}$ was measured in p-Pb collisions at a collision energy per nucleon-nucleon pair $\sqrt{s_{NN}}$ = 5.02 TeV and in pp collisions at collision energies of $\sqrt{s}$ = 0.9, 2.76, and 7 Tev in the kinematic range 0.15 with $N_{ch}$ is observed, which is much stronger than that measured in Pb-Pb collisions. For pp collisions, this could be attributed, within a model of hadronizing strings, to multiple-parton interactions and to a final-state color reconnection mechanism. The data in p-Pb and Pb-Pb collisions cannot be described by an incoherent superposition of nucleon-nucleon collisions and pose a challenge to most of the event generators