A new driver behavior model to create realistic urban traffic environment

This thesis assesses the use of a group of small, low-altitude, low-power (in terms of communication equipment), ?xed-wing unmanned aerial vehicles (UAVs) as a mobile communication relay nodes to facilitate reliable communication between ground nodes in urban environments. This work focuses on enhancing existing models for optimal trajectory planning and enabling UAV relay implementation in realistic urban scenarios. The performance of the proposed UAV relay algorithms was demonstrated and proved through an indoor simulated urban environment, the ?rst experiment of its kind.The objective of enabling UAV relay deployment in realistic urban environments is addressed through relaxing the constraints on the assumptions of communication prediction models assumptions, reducing knowledge requirements and improving prediction efficiency. This thesis explores assumptions for urban environment knowledge at three different levels: (i) full knowledge about the urban environment, (ii) partially known urban environments, and (iii) no knowledge about the urban environment. The work starts with exploring models that assume the city size, layout and its effects on wireless communication strength are known, representing full knowledge about the urban environment. [Continues.]

This paper addresses intention and trajectory prediction of exo-vehicles in an urban driving environment. Urban environments pose challenging scenarios for self-driving cars, specifically pertaining to traffic light detection, negotiating paths at the intersections and sometimes even overtaking illegally parked cars in narrow streets. This complex task of autonomously driving while considering anomalous situations make urban driving conditions unique when compared to highway driving. In order to overcome these challenges, we propose to use road contextual information to predict driving intentions and trajectories of surrounding vehicles. The intention prediction is obtained using a recurrent neural network and the trajectory is predicted using a polynomial model fitting of the past lateral and longitudinal components of the vehicle poses and road contextual information. The integrated process of intention and trajectory prediction is performed in real-time by deploying and testing on a self-driving car in a real urban environment.

The movie — The Matrix (1999) — boosted our imagination about how further we can be immersed within the cyber world, i.e., how further the cyber world can be indistinguishable from the real world. Nobody, including the creators, had expected that the aspirational fictional virtual worlds such as “ActiveWorlds (1995)” and “Second Life (2003)” would impact the way of experiencing our real urban environments with many urban experiences embedded into a rich featured 3D environment. Are we going to stay as ourselves while existing in a mirror world? Are the fabricated, created imaginary worlds becoming a part of real worlds or vice versa? The recent once-in-a-lifetime pandemic has confirmed the importance of location and time-independent Digital Twins (DTs) (i.e., virtual scale models) of cities and their automated services which can provide everybody with equity and accessibility. This study analyses how the metaverse (3D elevation of linear Internet), that aims to build high-fidelity virtual worlds with which to interact with, can be engaged within the Smart City (SC) ecosystem with high immersive Quality of Experiences (QoE) leading to increased Quality of Life (QoL). An urban metaverse ecosystem framework — MetaOmniCity — is designed to demonstrate a variety of insights and orchestrational directions for policymakers, city planners and all other stakeholders about how to transform data-driven SCs with DTs into virtually inhabitable cities with a network of shared urban experiences from a metaverse point of view. MetaOmniCity, allowing the metaversification of cities with granular virtual societies, i.e., MetaSocieties, and eliminating the boundaries between the real world and their virtual counterparts can be shaped to the particular requirements and features of cities. Urban metaverse shared worlds, an extension of residents and urban society, where the virtual and the physically real blend and are more organically integrated, would impact urban ways of living significantly with many practical implementations. This would open doors for potential businesses with tremendous global economic value by democratising skills/assets within an urban environment, paving the way for immersive globalisation with the bigger and richer metaverse of Country (MoC) and metaverse of World (MoW) being an immersive DT of the broader universe with tangibly connected cities. MetaOmniCity is expected to accelerate the building, deployment, and adoption of immersive urban metaverse networks for citizens to interface with as an extension of real social and individual experiences.

Measuring oppressiveness of streetscapes

The paper explores the technical limits and possibilities to transmit live audiovisual contents in the uplink mode by means of IP networks based on WiMAX broadband system using a professional camera. A previous evaluation of the WiMAX link performances in real urban environments is tackled, and then, obtained results used to implement an Automatic Video Coding Rate Adjustment (AVCRA) algorithm that adaptively adjusts the video codec parameters to the experienced wireless channel capacity. The experimental network also contains a designed antenna small enough to be incorporated in the camera. Special considerations regarding the radiation diagram have been taken into account for not affecting the head of the proper cameraman. Obtained experimental WiMAX throughput in function of the signal to noise ratio, and the Peak signal to noise ratio (PSNR) levels demonstrated the feasibility of live video links over WiMAX networks in urban environment.

The modeling of a new generation of agent-based simulation systems supporting pedestrian and crowd management taking into account affective states represents a new research frontier. Pedestrian behaviour involves human perception processes, based on subjective and psychological aspects. Following the concept of pedestrian environmental awareness, each walker adapts his/her crossing behaviour according to environmental conditions and his/her perception of safety. Different pedestrian behaviours can be related to subjective mobility and readiness to respond, and these factors are strongly dependent on the subjective interaction with the environment. Having additional inputs about pedestrian behaviour related to their perception processes could be useful in order to develop a more representative pedestrian dynamic model. In particular, the subjective perception of the safeness of crossing should be taken into consideration. In order to focus on the pedestrians’ perception of safe road crossing and walking, an experiment in an uncontrolled urban scenario has been carried out. Besides more conventional self-assessment questionnaires, physiological responses have been considered to evaluate the affective state of pedestrians during the interaction with the urban environment. Results from the analysis of the collected data show that physiological responses are reliable indicators of safety perception while road crossing and interacting with real urban environment, suggesting the design of agent-based models for pedestrian dynamics simulations taking in account the representation of affective states.

ABSTRACTA wide range of portable and wearable electronic travel aids have been developed to enable visually impaired people to move around public spaces without a sighted guide. However, few of them have gone beyond the prototype stage and the long cane and guide dog are still the main mobility aids. Despite the importance of evaluation to determine, for instance, effective functioning and end-user satisfaction, a standard approach has not yet been developed for mobility aids. The paper reports the evaluation of a low-cost electronic long cane, developed by the authors and colleagues in Brazil. It used a two-part methodology involving an experimental investigation of performance of the electronic long cane and a questionnaire to explore user satisfaction. The results of the experiments and questionnaire demonstrated both the cane’s usefulness and the need for modifications to improve its functioning. This work is also important for the development of methodologies for effective evaluation, as this is the first evaluation of a mobility device developed and carried out in Brazil. In addition, it is one of only a small number of evaluations in real locations with real obstacles. Finally, a series of recommendations for evaluating mobility devices is presented.What this paper adds?A standard approach to evaluating electronic travel for visually impaired people has not yet been developed and the most appropriate approach may depend on the objectives of the evaluation. Existing approaches generally use participants with no previous experience of using the device being evaluated and is carried out indoors with artificial obstacles. The training or device familiarisation period usually provided might be insufficient for participants to obtain optimal device performance or an effective comparison to be made of different devices. The approach to evaluating an electronic long cane reported in this paper has three main advantages over previous methods. The participants were experienced users of the electronic long cane who had been using it to support their daily mobility for at least a month. The evaluation was carried out in two different real urban environments with real obstacles. This has the advantages of being close to real-life cane use and participants being able to make informed comments and suggestions for improvements as a result of their experience. A questionnaire included questions on user satisfaction with and evaluation of a number of different cane features based on their experiences of cane use over a period. The work is also significant as the first detailed mobility device evaluation carried out in Brazil and in the presentation of a series of recommendations divided into themes for effective evaluation of mobility devices.

Objectives Sunlight pollution caused by glass curtain walls of buildings in urban environment has brought great threats to traffic safety, fire control and residents?? health. At present, most researches on architecture sunlight pollution traditionally focus a local small range at specific construction based on simula-tion or measurement methods. We keep the way of three-dimensional (3D) computation, dissimilarly inte-grates geographic resources to expand the perception range of city sunlight pollution brought by building glasses. Methods The calculation technique of sunlight pollution builds 3D spatial relationship among road, building facade and sunlight in real urban environment, using deep-learning image segmentation to extract glass curtain walls. Then, combined with glare evaluation model, we develop an innovative sunlight pollu-tion model from perspective of drivers to evaluate the suitability for people. Results Taking Shenzhen Fu-tian Center as an example, the multi-level analyses of sunlight pollution are implemented by means of calcu-lation under real time and real location, and path selection based on evaluation. Through these instances, the time sequence regularity, the spatial distribution characteristics and the path estimation of architecture sunlight pollution are revealed. Conclusions The analyses retain space computation mode with innova-tions, fully utilize street view resources, and provide people the macroscopic concept, which indicates rela-tive strength of building sunlight pollution. Additionally, the method ensures instantaneity of urban sunlight pollution acquisition and computation, to a certain extent covers shortages of current researches, and is fur-ther capable of reference evaluation in environment protection, accurate warnings and predictions of glare intensity for pedestrians and drivers.

A modified adaptive division beam tracing (MADBT) technique based on the localized kd-tree and the OpenMP–MPI parallel techniques is presented for the simulation of radio propagation in large-scale urban environments. Beams launched from a transmitter are recursively traced by applying the MADBT method and beam trees recorded the propagation path info are generated. By traversing the beam trees, all the valid propagation (transmitted, reflected and diffracted) paths are efficiently determined. Then the receiver power strength can be calculated based on geometrical optics (GO) and uniform theory of diffraction along the arrival paths. By tracing the continuous beams instead of a number of rays, the proposed method performs higher efficiency than the widely used ray tracing method. During the beam tracing procedure, several techniques are adopted to accelerate the calculation. Firstly, a localized kd-tree is built according to the coverage area of the transmitter, which is more efficient than the global kd-tree to do the beam-triangle intersection during the tracing procedure. Secondly, a virtual simulation face is generated to speed up the searching for ray paths. Lastly, the OpenMP and the MPI parallel technique are implemented to further enhance efficiency of the proposed method. As expected, the simulated results for the realistic Malaysia urban environment show good agreement with measured results and performance high efficiency.

This paper presents a study to design and analysis of an RF link budget analysis model with a primary focus on the real urban propagation microcell environment to analyze the mobile signal loss factors during the propagation and to calculate the transmitting signal power at the transmitter end. The link budget analysis prediction system utilizes a combined model that demonstrates appropriateness to reliable link design in order to develop a flexible RF link budget analysis prediction model for mobile communication systems cellular network link planning in urban propagation microcell environment.

Eco-driving control of connected and automated hybrid vehicles in mixed driving scenarios

Dynamic weighted aggregation for normality analysis in intelligent surveillance systems

The urban population, worldwide, is growing exponentially and with it the demand for information on pollution levels, vehicle traffic, or available parking, giving rise to citizens connected to their environment. This article presents an experimental long range (LoRa) and low power consumption network, with a combination of static and mobile wireless sensors (hybrid architecture) to tune and validate concentrator placement, to obtain a large coverage in an urban environment. A mobile node has been used, carrying a gateway and various sensors. The Activation By Personalization (ABP) mode has been used, justified for urban applications requiring multicasting. This allows to compare the coverage of each static gateway, being able to make practical decisions about its location. With this methodology, it has been possible to provide service to the city of Malaga, through a single concentrator node. The information acquired is synchronized in an external database, to monitor the data in real time, being able to geolocate the dataframes through web mapping services. This work presents the development and implementation of a hybrid wireless sensor network of long range and low power, configured and tuned to achieve efficient performance in a mid-size city, and tested in experiments in a real urban environment.

Along with the fast developments in VANET, a large number of attractive applications have emerged, which make routing of data in VANETs a great challenging task, especially in the complex urban traffic environment. The urban environment place restrictions on the packets that they should better be relayed along the road. Moreover, the increasing number of applications intensifies the traffic load condition of the whole network. However, most of the current routing protocols do not take into account the geographic information and traffic load together. In this article, we present a novel routing strategy based on using Geographic and Traffic Load information for VANET in urban traffic environment, GTLR (Geographic and Traffic Load Based Routing). In addition, we compare this new strategy with GPSR and GSR by means of delivering simulation in realistic environment, and the simulation results prove that GTLR outperforms them in terms of packet delivery ratio, and average packet end-to-end delay.

The effects of high-rise buildings on satellite propagation in the vicinity of urban canyons are investigated. A comparison between a conventional canyon model and the two modified canyon models, which take into account the presence of high-rise buildings, is presented for both narrow-band and wideband signal cases. The narrow band is developed using ray tracing (RT) and includes the direct wave, the specular reflection from building walls and ground, and the diffracted waves. In addition, multiple shadow boundaries are defined and used to carry out the uniform theory of diffraction calculations. The incident shadow boundary is the dominant boundary and is used to determine the line-of-sight region for all cases, while wall and ground reflection shadow boundaries are used to obtain higher precision due to multiple reflections. The wideband model is developed by applying a channel transfer function to the data obtained from the RT method. The proposed models are used to predict the received signal in a realistic urban environment from satellites. The models are applicable to any satellite link application, such as global navigation satellite systems, low Earth-orbiting, and high-altitude platform systems, and the results are obtained for a satellite transmitting two linearly polarized signals at a frequency of 1.625 GHz. It is found that the presence of high-rise buildings next to a street canyon can significantly alter the visibility of satellites, which, in turn, lead to an increase in path loss. Consequently, ignoring high-rise buildings in the proximity of a street canyon can lead to a path loss difference of as much as 30 dB.