High concentrations of ozone (O3) is a major air problem in urban areas, which creates serious threat to human health. Urban street canyon morphology plays key role pollutant dispersion and photochemical reaction rate. In this study, one-year observation at three height levels was performed investigate the O3 distribution vertically Shenyang. Then, field investigation ENVI-met modelling were co...

Hong Kong is a typical high-density city in subtropical climate region, and deep street canyons are among the main features of its urban planning. How geometry influences thermal environment this has become hot topic these days. The height-to-width ratio (H/W) sky view factor (SVF) commonly used to indicate outdoor performance, while previous studies rarely analysed importance bias two influenc...

This study aimed to evaluate the wind environment in step-up and step-down urban canyons through a computational numerical experiment using fluid dynamics (CFD) model. Spatial structural conditions were considered according location of high-rise buildings, changing patterns inside compared analyzed by varying building heights. Under condition, velocity canyon weakened, vertical vortex formed, a...

Stay points are important for recognizing significant places from a mobile user’s GPS trajectory. Such places are often located indoors and in urban canyons, where GPS is unreliable. Consequently, mapping a user’s stay point to a Place of Interest (POI) using only GPS data is particularly challenging. Our novel algorithm employs both spatio-temporal density estimation and line count inference t...

Accurate and continuous position calculation is a key task for vehicle navigation and telematics applications. In most portable car navigation and telematics devices, the position is calculated based only on GPS data. However, in urban canyons stand-alone GPS suffers signal masking and reflections of the signal from buildings, large vehicles, and other reflective surfaces. Driving tests in such...

In this study we investigate ultrafine particle (UFP) fluxes using a first order eddy viscosity turbulence closure Computational Fluid Dynamics (CFD) model and determine the different factors that influence emissions of UFP into the urban boundary layer. Both vertical turbulent fluxes as well as the fluxes due to mean circulatory flow are shown to contribute to the overall ventilation character...

We present a method for navigation of a small unmanned rotorcraft through an unsurveyed environment consisting of forest and urban canyons. Optical flow measurements obtained from a vision system are fused with measurements of vehicle velocity to compute estimates of range to obstacles. These estimates are used to populate a local occupancy grid which is fixed to the vehicle. This local occupan...

In recent past, significant efforts have been made to improve the scientific understanding of exhaust dispersion phenomenon in urban street canyons/intersection. The amount of turbulence generated by natural winds within the street canyon might be smaller than that of traffic induced turbulence. Therefore, the influence of traffic-induced turbulence on exhaust dispersion has to be quantified. I...

Autonomous flight in confined or cluttered environments such as houses or urban canyons requires high manoeuvrability, fast mapping from sensors to actuators and very limited overall system weight. Although flying animals are well capable of solving this problem, roboticists have difficulties at reproducing such capabilities. This paper describes why and how we took inspiration from flying inse...