Detailed computational simulations of turbulent flows and pollution dispersion in city canyons have been carried out using the computational fluid dynamics package CFX-5, which is capable of using unstructured meshes and a variety of turbulence closure schemes. The simulations have been done for city canyons with simple to complex structures. As a validation of CFX-5, a roof garden test is cond...

Wind tunnel experiments have been carried out at the EnFlo laboratory to measure mean and turbulent tracer fluxes in geometries of real street canyon intersections. The work was part of the major DAPPLE project, focussing on the area surrounding the intersection between Marylebone Road and Gloucester Place in Central London, UK. Understanding flow and dispersion in urban streets is a very impor...

Flow and traffic-originated pollutant dispersion in an urban street canyon with avenue-like tree planting have been studied by means of wind tunnel and CFD investigations. The study comprises tree planting of different crown porosity, planted in two rows within a canyon of street width to building height ratio W/H = 2 and street length to building height ratio L/H = 10 exposed to a perpendicula...

A general proecological urban road traffic control idea for the street canyon is proposed with emphasis placed on development of advanced continuum field gasdynamical (hydrodynamical) control model of the street canyon. The continuum field model of optimal control of street canyon is studied. The mathematical physics approach (Eulerian approach) to vehicular movement, to pollutants’ emission an...

In this paper we discuss a pilot study where we have mapped urban air pollution using mobile carbon monoxide (CO) sensors. Our objective is to use inexpensive Global Positioning System (GPS) receivers to track the sensors and explore CO variations at a fine geographic scale. The critical issue in data processing is the treatment of the imprecise logs from the GPS. By using knowledge about the r...

This study investigates theoretical signal control algorithms based solely on probe vehicle data. Through development of a simulation system that can model urban signalised junction control using localisation probe data from all vehicles in the local area, improvements in junction operational efficiency that result from the improved input data are demonstrated for both isolated and coordinated ...

We address the problem of navigating unmanned vehicles safely through urban canyons in two dimensions using only vision-based techniques. Two commonly used vision-based obstacle avoidance techniques (namely stereo vision and optic flow) are implemented on an aerial and a ground-based robotic platform and evaluated for urban canyon navigation. Optic flow is evaluated for its ability to produce a...

Editorial comment

with the wind permanent flow in the cities, obtaining the minimal pollution in the environment is accessible. different policies have been considered for optimization of cities such as attachment and or reduction of building parts like air-traps, ceiling forms and so on. due to population growth in cities and the increasing need for resettlement these people in the cities, inevitably, to the hi...

Abstract Factor graph optimization (FGO) recently has attracted attention as an alternative to the extended Kalman filter (EKF) for GNSS-INS integration. This study evaluates both loosely and tightly coupled integrations of GNSS code pseudorange INS measurements real-time positioning, using conventional EKF FGO with a dataset collected in urban canyon Hong Kong. The strength is analyze...