Noise event measures for road traffic

How should noise events in road traffic noise be measured? This paper reports the performance of a set of algorithms that detect noise events in time histories of road traffic noise in the population of acoustic conditions found near roadways. The latter was obtained through simulation of 500 different road traffic noise time histories using a comprehensive range of traffic flow, traffic composition, and propagation distance, conditions in unshielded locations near roadways. The initial set of algorithms tested was developed by systematically expanding on threshold-based algorithms described in the literature, then excluding those that were unreliable. The finding was that the NA50 and NA55 (detecting when road traffic noise exceeded 50 dB and 55 dB respectively), and the NAL50E10 (detecting when the traffic levels exceeded L50 + 10 dB) can all be considered for practical application as event detection indicators. All apply to measurement of indoor events with the windows of the dwelling open. The primary criterion for selection as supplementary indicators (and others in the same clusters that could substitute for them) was their non-monotonic relationship with the LAeq, The traffic and distance conditions under which these event-based measures could potentially be useful supplementary indicators is identified.Griffith Sciences, Griffith School of EnvironmentFull Tex

Measurement of noise events in road traffic streams: initial results from a simulation study

A key question for road traffic noise management is whether prediction of human response to noise, including sleep quality, could be improved over the use of conventional energy equivalent, or percentile, measures, by accounting for noise events in road traffic streams. This paper reports initial results from a noise-events investigation into event-based indicators over an exhaustive set of traffic flow, traffic composition, and propagation distance, conditions in unshielded locations in proximity to roadways. We simulate the time-varying noise level histories at various distances from roadways using a dynamic micro-traffic model and a distribution of sound power levels of individual vehicles. We then develop a comprehensive set of noise event indicators, extrapolated from those suggested in the literature, and use them to count noise events in these simulated time histories. We report the noise-event algorithms that produce realistic, and reliable, counts of noise events for one-hour measurement periods, then reduce redundancy in the indicator set by suggesting a small number of representative event indicators. Later work will report the traffic composition and distance conditions under which noise event measures provide information uncorrelated with conventional road traffic noise indicators — and which thus may prove useful as supplementary indicators to energy-equivalent measures for road traffic noise

Processual models of radicalization into terrorism : a best fit framework synthesis

The pre-emptive turn in the criminal justice system, and more in particular in the counterterrorism context, has brought legislators to intervene as early as possible and to target remote risks. However, when drafting far-reaching legislation, hardly any attention is given to the underlying phenomena. This article therefore aims to review existing processual models of radicalization that provide insight into the sequence of the trajectory towards terrorism. These models are often isolated and comparative reviews have been scarce and partial in scope. Through a best fit framework synthesis, this contribution systematically identifies existing models and frameworks in the literature and analyses them thematically. As a result, a meta-framework, represented by an eight-phased horizontal funnel, embodies the current state of research on phase models of radicalization. The eight phases cover the entire process from pre-radicalization, to five radicalization phases sensu stricto, to implementation and post-implementation. In these phases, multiple concepts that relate to grievances, cognitions, groups and violence are identified. The meta-framework, or integrated funnel model, evidences the pre-crime hypothesis and shows that far-reaching criminal law provisions intervene at too early stages of the radicalization process