Mathematical Problems of Collaborating Robotic Vehicle Traffic

Предложен подход для моделирования динамики транспортных потоков для взаимодействующих аппаратов на основе теории самосогласованного поля, основанного на уравнениях А.А. Власова. Сформулированы проблемы применимости таких моделей для описания коллективных явлений трафика в связи с задачами поведения «стаи» роботизированных однородных взаимодействующих аппаратов в фазовом пространстве на основе кинетического подхода. An approach to the simulation of time-dependent collaborating vehicle traffic flows based on the self-consistent field theory and A. Vlasov equations are proposed. The problems of the simulation model applicability to collaborative traffic processes such as the behavior of a swarm of identical collaborating vehicles in phase space using the kinetic approach are stated.

Influence of Vehicle Traffic Emissions on Spatial Variation of Ozone and its Precursors in Air of Port Harcourt City, Nigeria

This study aimed at assessing the influence of vehicle traffic on spatial variation of ozone (O3) and its vehicular emission precursors in the air of Port Harcourt city. Sampling was carried out in ten (10) sites, eight (8) located within the high traffic density area (study sites) and two (2) located within the very low traffic density area (reference sites). The precursor pollutants measured were nitrogen dioxide (NO2), carbon monoxide (CO) and volatile organic compounds (VOCSs). Ozone and the precursor pollutants were measured in situ using AeroQUAL 500 series portable ambient air analyzer while traffic flow survey was achieved by direct counting. Measurements were carried out at morning, evening and off-peak traffic periods respectively. The mean concentrations of ozone and the precursor pollutants were significantly higher (p = 0.05) in the study sites than in the reference sites. Mean concentrations were higher at peak traffic periods than at off-peak traffic periods except for ozone that was higher at off-peak than at morning peak. There was significant correlation between traffic density and each of the pollutants including ozone. The spatial variability in concentration of pollutants was influenced by vehicular traffic. VOCs and NO2 levels were higher than the National Ambient Air Quality Standard (NAAQS) limit of 0.05 ppm and 0.04 – 0.06 ppm respectively, O3 concentration was below the standard limit (0.06 ppm) but was at the verge of exceeding. Traffic emission within the city was significant and could be mitigated through regular monitoring and control.

A Distributed Mix-Context-Based Method for Location Privacy in Road Networks

Preserving location privacy is increasingly an essential concern in Vehicular Adhoc Networks (VANETs). Vehicles broadcast beacon messages in an open form that contains information including vehicle identity, speed, location, and other headings. An adversary may track the various locations visited by a vehicle using sensitive information transmitted in beacons such as vehicle identity and location. By matching the vehicle identity used in beacon messages at various locations, an adversary learns the location history of a vehicle. This compromises the privacy of the vehicle driver. In existing research work, pseudonyms are used in place of the actual vehicle identity in the beacons. Pseudonyms should be changed regularly to safeguard the location privacy of vehicles. However, applying simple change in pseudonyms does not always provide location privacy. Existing schemes based on mix zones operate efficiently in higher traffic environments but fail to provide privacy in lower vehicle traffic densities. In this paper, we take the problem of location privacy in diverse vehicle traffic densities. We propose a new Crowd-based Mix Context (CMC) privacy scheme that provides location privacy as well as identity protection in various vehicle traffic densities. The pseudonym changing process utilizes context information of road such as speed, direction and the number of neighbors in transmission range for the anonymisation of vehicles, adaptively updating pseudonyms based on the number of a vehicle neighbors in the vicinity. We conduct formal modeling and specification of the proposed scheme using High-Level Petri Nets (HPLN). Simulation results validate the effectiveness of CMC in terms of location anonymisation, the probability of vehicle traceability, computation time (cost) and effect on vehicular applications.

ASSESSMENT OF THE ENVIRONMENTAL SAFETY FACTORS OF PLAY-GROUNDS USING THE RANK CORRELATION METHOD

The process of rapid development in modern cities has led to a significant number of playgrounds being located in confined areas, near roads with heavy vehicle traffic (including tram tracks), next to short-term parking spaces and refuse containers. Particular attention is paid to unauthorised parking which is caused by a lack of designated parking spaces. In addition, in residential areas of modern megacities there is a lot of infill development, which is an additional source of noise and dust. Thus, a significant number of playgrounds are located in areas with excessive anthropogenic load. The materials presented in the article describe the current condition of playgrounds in most big cities of Ukraine. Particular importance is attached to the factors which are connected with vehicle traffic, for example noise pollution, air dustiness and pollutant emissions. At the first stage, a list of factors affecting the environmental safety of children's playgrounds in urbanised areas was compiled and analysed. The next stage involves the development of a questionnaire and the direct assessment of the influencing factors by the experts involved. The article considers the factors that are rarely considered in the study of the impact of individual anthropogenic factors of the environment on public health, however, in modern conditions they cannot be neglected. The final stage consists of data processing and formation of conclusions. Using the method of rank correlation, the main factors of influence on the objects of research are identified. The results of the research stated in the article can be used in further study of the subject and in the development of methods to eliminate the influence of the most significant factors affecting the ecological safety of children's playgrounds.

Variable-Drift Diffusion Models of Pedestrian Road-Crossing Decisions

Human behavior and interaction in road traffic is highly complex, with many open scientific questions of high applied importance, not least in relation to recent development efforts toward automated vehicles. In parallel, recent decades have seen major advances in cognitive neuroscience models of human decision-making, but these models have mainly been applied to simplified laboratory tasks. Here, we demonstrate how variable-drift extensions of drift diffusion (or evidence accumulation) models of decision-making can be adapted to the mundane yet non-trivial scenario of a pedestrian deciding if and when to cross a road with oncoming vehicle traffic. Our variable-drift diffusion models provide a mechanistic account of pedestrian road-crossing decisions, and how these are impacted by a variety of sensory cues: time and distance gaps in oncoming vehicle traffic, vehicle deceleration implicitly signaling intent to yield, as well as explicit communication of such yielding intentions. We conclude that variable-drift diffusion models not only hold great promise as mechanistic models of complex real-world decisions, but that they can also serve as applied tools for improving road traffic safety and efficiency.