Buildings In Urban Environment Research Articles

Rapid data collection and processing in dense urban edge computing networks with drone assistance

In the edge computing network systems for the Internet of Things (IoT), there is growing attention to utilizing drones for collecting data and maintaining the freshness of data processing. This study focuses on analyzing the problems related to trajectory planning and task scheduling in a single drone-assisted edge computing network within a dense, three-dimensional urban environment. We first design an edge computing network architecture and establish an air-to-ground channel model between the drone and ground mobile devices to address the blockage caused by buildings in urban environments. Subsequently, to provide effective edge computing services, we structure the problem as a Partially Observable Markov Decision Process (POMDP) and introduce an optimization framework based on reinforcement learning. This improves data timeliness and reduces energy consumption.

Assessment of Societal Health Risks: Spatial Distribution and Potential Hazards of Toxic Metals in Street Dust Across Diverse Communities

On a global scale, the urban design of city centers is a topic of discussion concerning various aspects such development and its impact on public health. This research examines the health effects of urban agglomeration in city centers with compact, close development. In this work, the potentially toxic metals in street dust were studied by collecting and measuring street dust samples, measuring trace metal concentrations, and using index assessment, spatial analysis, correlation analysis, and health risk assessment models. Eskişehir, located in the part of Central Anatolia close to the Aegean region, west Türkiye, has been widely recognized as one of the most popular, known for having many narrow and old buildings in urban environments. The present paper investigates the atmospheric dust-related chemical speciation, urban environmental pollution, and human health risks in Eskişehir City by studying 66 dust samples collected at 11 points in the selected streets in August 2023. the study found that the concentrations of trace elements followed the order Cr > Ni > Pb > Cd > Cu. The primary source of these high levels is believed to be traffic-related contamination involving Cd, Pb, and Ni. The assessment of non-carcinogenic health risks has shown that the significant sources of potential toxic metals exposure for both children and adults are i) through ingestion and ii) dermal contact. The Hazard index (HI) for selected metals decreased in the order Cr > Pb > Ni > Cd > Cu for both children and adults without imposing possible non-carcinogenic risk (HI<1). On the contrary, Cr posed cancer risks above the safety threshold (> 10-4) through ingestion. Based on the available findings, Eskişehir still suffers from considerable environmental and ecological degradation and severe health risks due to street dust contamination. However, while high pollution was detected in the city center, where there is commercial land use, low values were observed in the region, rich with the water surface, bicycle paths, landscape design, and where traffic is slowed down.

The Features of Creation of an Urban Building Environment with Completion of Underground Infrastructure Areas of the City of Yerevan

Underground areas are those parts of the city that can become the best way to overcome the expansion of the surrounding areas of the city, thanks to which new ideas can be created and developed, achieving eco-economic success, creating new opportunities to ensure people's livelihood and security. Underground areas can include transportation structures, passageways, industrial buildings, and public service infrastructure. Basically, the underground areas, developing vertically on several levels, extend under the crowded zones of the city center, in the areas adjacent to the transport hubs. The unloading of above-ground urban areas can lead to the positive process that freed areas will be used to create green zones, improving the sanitary and hygienic condition of the city. It will allow maintaining the existing urban environment, creating favorable conditions for improving people's living activities.

Evaluation of solar energy potential for residential buildings in urban environments based on a parametric approach

Building integrated photovoltaics is an important measure to promote low-carbon urban growth. The residential buildings, which play an important role in cities, have a great development potential to utilize solar resources. However, the solar utilization performance of buildings in a block is influenced by the shadings from surrounding buildings with diverse layouts and heights. Therefore, this study proposes a parametric approach to evaluate the solar energy potential of residential buildings by randomly generating 6730 block environments. We quantify and prioritize how block parameters influence the solar energy potential, and provide photovoltaics (PV) utilization strategies for the roof and façades of the building in diverse urban environments. The average photovoltaic installation ratio of roof, south and west façade can reach 98%, 46.3% and 38.5% when the target building height is higher than 24 m. Among all the block parameters, the target building height and its interactions with other parameters can collectively contribute more than 80% to the solar potential of building surfaces. Correspondingly, the two most influential parameters on the PV generation and installation are obtained for PV utilization strategies of building roof, south and west façade. The proposed framework and findings are expected to offer inspirations for solar design in urban buildings.

On the cooling energy impacts of combined urban heat mitigation strategies in subtropical urban building environment

Regional climate change leads to more extreme urban heat in desert cities. This affects the building's performance negatively through an increase in cooling energy consumption. To our knowledge, this is the first study investigating the impacts of implementing combined urban heat mitigation strategies of cool materials and increased vegetation on the cooling load demands of 40-various types of buildings in Dubai downtown. Four urban heat mitigation scenarios have been conducted in combination with a base case scenario to examine the effectiveness of the combined strategies in reducing the cooling load demand by using the climatic data from weather research and forecasting model coupled with single layer urban canopy model (WRF/SLUCM) in CitySim. Results revealed that for non-insulated buildings there was an estimated 17.2% to 36.4% reduction in cooling energy demand whereas insulated buildings have an average reduction in energy demand ranging between 15.5% and 29.1%. This reduction in cooling energy consumption is higher when compared with other mitigation techniques like additional urban vegetation and modified cool materials.

HiMAQ: Hierarchical multi-agent Q-learning-based throughput and fairness improvement for UAV-Aided IoT networks

Recently, various types of Internet of Things (IoT) services have become wide spread, and new types of IoT devices are emerging. However, the significant number of high-rise buildings in urban environments renders it difficult to provide seamless and high-speed network connectivity consistently to these IoT devices via existing terrestrial IoT networks. Therefore, we herein consider unmanned aerial vehicle (UAV)-aided IoT networks, in which a ground base station (GBS) and a UAV base station (UBS) coexist. In this paper, a hierarchical multi-agent Q-learning (HiMAQ) framework is proposed to maximize the system throughput while minimizing device outage in UAV-aided IoT networks. The proposed HiMAQ adopts distributed multi-agent inner-loop reinforcement learning (RL) for determining the optimal transmission power of UBSs and GBSs, and distributed outer-loop RL to determine the optimal UBS deployment. This hierarchical RL architecture can reduce the computational complexity of the proposed RL approach compared with the centralized RL approach. The performance of HiMAQ in various network conditions is demonstrated considering the mobility of IoT devices and even/uneven spatial traffic distributions. Simulation results show that the proposed HiMAQ can maximize the system throughput and minimize the number of outage devices compared with various benchmark algorithms.

A Simplified Method for the Risk Analysis of Protection Against Lightning: Theory and a Case Study

Lightning strikes can cause physical harm to people and damage inside commercial, industrial, and residential structures. The risk of damage from lightning depends on the dimensional and environmental characteristics of the structure, the number of people and their permanence in the structure, their reaction to a possible fire, and the density of lightning strikes to the ground in the structure location. The assessment of the prospected risk determines the need for protective measures if it is higher than the tolerable value. The standard IEC/EN 62305-2 proposes a method to calculate the probable average annual loss in a structure due to lightning flashes. Since the standard is oriented toward analyzing the greatest number of types of structures, the analysis is complex and laborious because of the multitude of parameters to be used. The aim of this article is to facilitate an easy understanding of the basic parameters to consider and to introduce an analysis aimed at typical cases of buildings in urban environments to simplify the International Electrotechnical Commission (IEC)/EN method. We introduce an effective parameter: the per unit (p.u.) risk value related to the tolerable risk. The applications of the suggested simplified formulas to real cases have provided results that absolutely coincide with the values calculated by applying the IEC/EN formulas. Table 1 list the symbols used in this article.

A climate sensitive design approach to BIPV: Investigating the nexus between solar energy and thermal comfort in cities in Sweden and Cyprus

The research performed attempts to answer the question of how building integration of active solar systems may affect the thermal comfort in open areas and the interstitial space between buildings in urban environments. This is done by using computer simulation and in-situ observations at the extreme northern and southern geographies of Europe, namely in Luleå, Sweden and in Limassol, Cyprus. A typical example of the urban grid of each city is chosen and active solar systems are integrated on the facades of buildings, respectively foreach case. The thermal conditions at street level are then simulated, using Envi-MET, before and after systems integration, with the aim of assessing the differences between low and high insolation conditions, using the Physiological Equivalent Temperature (PET) indicator. Subsequently, the thermal conditions in the public space between buildings were once again assessed, with reduced emissivity values for the building integrated PV panels. The results point to the fact that the building integration of PVs lacking low emissivity coatings can have an impact in the thermal comfort of users in the locations specified, especially in the summer, wherein it is shown to be negligible in the southern case study but more significant in the northern one.

Seismic risk scenario for the historical centre of castelpoto in Southern Italy

AbstractThe study proposed a seismic vulnerability methodology applied to the historical centre of Castelpoto, located in the province of Benevento (Southern Italy). The seismic vulnerability of the examined aggregates was examined using an index‐based procedure specifically developed for structural masonry compounds. The structural details and specific characteristics of building aggregates are crucial in determining the seismic vulnerability of buildings in urban environments. Parameters such as the plan configuration, size, and layout of buildings, including the thickness, height of the masonry walls and the connections among different components of the construction, were appropriately considered, since all might have an impact on their seismic performance. Furthermore, the type of masonry, the strength and composition of the mortar, as well as the quality of constructions, can also contribute to the global seismic performance of buildings. These structural parameters, collected in the used form, were correlated to the Masonry Quality Index (MQI) to provide an exhaustive assessment of the capacity (in‐plane and out‐of‐plane mechanisms) of the bearing elements towards seismic loads. Secondly, the susceptibility to damage of the existing building stock was evaluated by applying a parametric simulation of damage scenarios adopting an appropriate Intensity Prediction Equation (IPE). To this purpose, fault models were acquired from the Database of Individual Seismogenic Sources (DISS) and the considered IPE was validated according to the Italian Macroseismic Database (DBMI). Thus, the proposed research aims to highlight how an accurate assessment of masonry strength is crucial during the inspection phase to optimise the prediction of the expected damage scenario allowing for effective risk mitigation in urbanised contexts.

Low-latency GNSS multipath simulation and building wall detection in urban environments

Precise navigation for fully autonomous driving—especially in dense urban areas—requires periodic precise position estimates. Global Navigation Satellite System (GNSS) technology has the potential to provide absolute positioning accuracy at a centimeter level. However, buildings in urban environments cause signal distortions and signal reflections—the so-called multipath—which are the most challenging parts in the GNSS error budget. Hence, we developed a scalable real-time multipath simulator for mitigating potential multipath receptions. The simulator uses three-dimensional (3D) building information, satellite, and user positions. The key drivers of latency are the calculation of reflection, diffraction, and line-of-sight, as well as the response time of the 3D building model database. The memory manager of the graphic processing units (GPUs) in combination with a dedicated load balancer enables fast and efficient multipath analysis. Selected case studies demonstrate the simulator’s potential to significantly improve the position accuracy of the processing engine. The use of the multipath simulator reduces the error in 61% of the error measurements in a stress test scenario to less than half of the non-multipath processing. The scalability of the simulator is demonstrated by combining the multipath simulator with a traffic simulator. Furthermore, we present a novel methodology for the detection of walls using GNSS signals to better account for incomplete or erroneous 3D building information in GNSS signal processing.

A Novel Performance-Based Evaluation of Built-Up Wide-Flange Steel Columns Subjected to Close-Range Detonations

Transportation facilities are crucial civil engineering structures, which are vulnerable to increasing risks of potential explosive loadings. The structural members of older facilities were typically made of steel and built up from angles and plates joined together with rivets, rather than directly rolled in steel mills. Most existing blast mitigation design approaches were made for military or petrochemical facilities in rural areas with significant stand-off distances. However, transportation facilities, which are located in congested major cities, with structural members exposed to pedestrians and passengers, are subject to the risks of potential close-range or near-contact detonations. Recently, new approaches were developed to address the potential progressive collapse of high-rise buildings in urban environment, but the approaches do not address the localized deformations or failures on column flange or web elements that are common in close-range or near-contact detonations. For this reason, the existing approaches are not appropriate to the blast mitigation design of the urban transportation structures. Instead, a high-fidelity, nonlinear, explicit finite element analysis is suggested. Typical practicing structural engineers do not have opportunities for education or training for such analysis due to technical challenges, cost, and time constraints. The main goal of the present research is to provide practical guides of the nonlinear, explicit finite element analyses for close-in or near-contact detonation problems that can be followed by practicing structural engineers and to provide simple design charts that can be used as a preliminary tool without performing the analyses. To accomplish the goal, more than 200 parametric study models were built for nonlinear, explicit finite element analysis of built-up steel columns subjected to close-in detonations. Characteristics of the steel materials for the built-up columns were investigated and incorporated in the numerical models. The models were determined so that they can cover practical ranges of columns, stand-off distances, and charge weights. The analysis results were presented on contour graphs using novel performance-based damage criteria. The graphs and design methodology presented in this study can be used as an efficient and practical tool to quickly assess blast resistance of built-up steel columns in transportation structures.

Real-time Wind Predictions for Safe Drone Flights in Toronto

Tall buildings in urban environments can negatively affect drone navigation, by creating turbulence and local regions of high-velocity winds. This jeopardizes the safety of the public in addition to the security of any items being transported by the drone such as medical equipment, packages, or expensive sensors. This study focuses on studying the effect of buildings located in the downtown area of the City of Toronto on the wind field. The City of Toronto was chosen due to the recent structures' development of and the increased usage of drones by hospitals and other businesses. The city geometry was divided into 20 zones and Computational Fluid Dynamics was utilized to study the effects of the local building geometry on the wind field. Wind velocities were extracted from the CFD data and coupled with historical meteorological data so that they could be compared to local weather station measurements. The coupled velocities and wind bearings from CFD were found to be within 12% and 8% RMSE respectively of the recorded data at the wind station for 85% of the sampled data. Wind velocities were then extracted at regular elevation intervals within the flight environment and coupled with meteorological weather data to generate historical, real-time, forecast, and statistical visualization of local wind fields. This study proposes a technique for obtaining real-time, historical, forecast, and statistical wind speeds and wind bearings in the drone flight environment or along a specified path. Visualization of flow fields is also presented to improve drone flight safety and efficiency.

Exclusive impacts of lifestyles on preference for interior public space of high-rise building apartment

PurposeWhile interior public space can be one of the most important criteria in designing high-rise residential buildings in urban environments in practitioners’ opinion, this study aims at investigating the importance of this criterion from consumers’ lifestyle standpoint. In particular, this study aims to examine the effects of different lifestyle orientations on consumers’ preference for this housing feature. Three relevant lifestyles are investigated including independence, family-orientation and homebody.Design/methodology/approachSurvey data were collected from 331 owners of high-rise apartments in three residential buildings in urban areas.FindingsThe research results revealed significant and positive effects of independence and homebody lifestyle orientations on consumers’ preference for interior public spaces. Interestingly, a family-oriented lifestyle was found to negatively moderate the effect of a homebody lifestyle on the preference, providing evidence for possible exclusive impacts of different lifestyle orientations on the preference.Originality/valueThis study emphasizes the exclusive impacts of different lifestyles on consumers’ preference for housing features that need to be considered by developers and marketers when designing consumer positions and marketing strategies.

Fast Seismic Assessment of Built Urban Areas with the Accuracy of Mechanical Methods Using a Feedforward Neural Network

Capacity curves obtained from nonlinear static analyses are widely used to perform seismic assessments of structures as an alternative to dynamic analysis. This paper presents a novel ‘en masse’ method to assess the seismic vulnerability of urban areas swiftly and with the accuracy of mechanical methods. At the core of this methodology is the calculation of the capacity curves of low-rise reinforced concrete buildings using neural networks, where no modeling of the building is required. The curves are predicted with minimal error, needing only basic geometric and material parameters of the structures to be specified. As a first implementation, a typology of prismatic buildings is defined and a training set of more than 7000 structures generated. The capacity curves are calculated through push-over analysis using SAP2000. The results feature the prediction of 100-point curves in a single run of the network while maintaining a very low mean absolute error. This paper proposes a method that improves current seismic assessment tools by providing a fast and accurate calculation of the vulnerability of large sets of buildings in urban environments.

Simulating the assembly size on seismic response of building clusters using PLAXIS

Behaviour of any building under the influence of earthquake depends on the flexibility of the foundation, free field ground motion and soil structure interaction. In currently adopted design methods, earthquake resistant structures are designed as isolated buildings. However, the effect of two adjacent buildings on each other cannot be totally neglected, given the fact that their foundation is in the same soil layer and in vicinity to each other especially in urban areas where buildings are arranged in clusters. The present aims at investigating the nature of interaction between soil and structure and its effect on seismic response of adjacent buildings in urban environment (building clusters) using numerical modelling technique (Plaxis 8.2). The proposed analysis model was studied for dynamic response due to harmonic excitation for building cluster. The response spectra for building cluster with variation in number of buildings and number of storeys in each building was studied. It was concluded that the seismic response was effected by the size of cluster and developed general conclusions for the dynamic responses for various cases.

Comprehensive Evaluation of Functional Diversity of Urban Commercial Complexes Based on Dissipative Structure Theory and Synergy Theory: A Case of SM City Plaza in Xiamen, China

Urban commercial complex is an architectural form formed in the high-density urban building environment based on the diversified concentration of human consumption behavior and the composite utilization of space. It can effectively cope with the problem of tight land resources and insufficient development capacity in urban centers and promote sustainable urban development. Additionally, the diversity of functions is the key to ensure its healthy operation. Based on the homogenization phenomenon of commercial complex development in some big cities in China in recent years, this study applies dissipative structure theory and synergistic effect theory to the study of functional diversity system of urban commercial complexes, and proposes a Shannon–Weiner biodiversity index model and calculation indexes based on the functional diversity measurement model. At the same time, correlation analysis and comparative analysis were conducted between the measurement results of spatial vitality and the calculation results of the diversity model to verify the scientificity and rationality of the proposed model. Finally, the SM City Plaza commercial complex in Xiamen was selected as a representative research object to measure the functional diversity of its weekdays and holidays and the coupling relationship between functional diversity and changes in spatial vitality. The calculation results show that although the comprehensive index of functional diversity of SM commercial complex is in a dynamic state of change, the overall level is high. The reasonable proportion of the six functional formats shows a high level of diversity, which effectively promotes the generation of commercial vitality and enhances the comprehensive benefits of the commercial complex; the change trends of functional diversity in time and space dimensions are in line with the actual situation, indicating that the proposed model has certain scientific and application values. On the basis of the completed empirical work, the scope of application and limitations of the calculation model and evaluation method, as well as the optimization of the index system are further pointed out.

Long-term study on wood degradation in urban soil-water systems - implications for service life of historic foundation piles

Many historic buildings in urban environments are raised on wooden foundations, and due to microbial degradation their service life varies greatly. This is one of the first field experiments in urban environments where wood decay is studied on proxy samples and related to ongoing processes in historic foundation piles. Here 90 proxy samples are exposed at 8 urban sites for 6, 12, and 18 months in the centre of Gothenburg. Development of microbial decay is followed in dipwells adjacent to well-studied historic piles. Analyses by light microscopy show that decay took place at all sites. Erosion bacteria were the sole degrader of wood at ¾ of the sites, both at groundwater level and at pile head level, indicating near anaerobic conditions in the soil pore water. At the two remaining sites, soft rot was also active. Decay increased over time and results demonstrate a significant correlation between depth of exposure below groundwater level and decrease in decay rates. Decay intensity varied between the sites, indicating that other site-specific conditions affect microbial activity. Redox and oxygen measurements did not show any correlation to observed decay intensity in proxy samples. Advise to stakeholders and for future studies are given.

Single‐station radar‐based UAV position estimation in complex urban environments

In the complex electromagnetic environment of cities, detection and positioning of slow and small unmanned aerial vehicles (UAVs) have always been a very challenging research topic. Usually, multiple radar observation stations are required to detect and track targets. Moreover, each radar observation station requires strict synchronisation, and the system is complex and costly. In view of this, under the condition of known prior information of urban geography, this study proposes a method to locate UAVs in complex electromagnetic environments, which use multiple virtual mirror synchronous radars constructed by multipaths and created by the complex buildings in urban environments. First, the simulation model is constructed, and the corresponding simulation parameters are given. Then, the algorithm for solving the single-station radar location is proposed, and the algorithm is verified by the simulation of a ray propagation model. Finally, the proposed algorithm is further verified based on the measured data captured by the radar system in Section 2. The results show that the proposed algorithm based on the single-station radar is able to locate the UAV in both line-of-sight and non-line-of-sight site, and its positioning accuracy is better than 1 m.

Sensitivity of near-surface meteorology to PBL schemes in WRF simulations in a port-industrial area with complex terrain

Parameterizations of the Planetary Boundary Layer (PBL) embedded in numerical weather prediction models are crucial in the simulation of local meteorology and require a special investigation. In this study we evaluate simulations at 1 km horizontal resolution using six PBL schemes of the Weather Research and Forecasting model (WRF) by comparison to observations performed in a coastal port-industrial area (Civitavecchia) on the Tyrrhenian coast of Central Italy. During the measurement campaign (April 2016) three types of atmospheric circulation regimes were identified: “breeze”, “jet” and “synoptic”. Some generalizations can be inferred from the results, despite the variety of settings analyzed (two sites, three regimes in both day and night conditions). Our results show that the temperature simulation is much more sensitive to the configuration at night than during the day, especially on breeze days, when the occurrence of stable boundary layer is favored. For wind speed, non-local schemes are very similar to each other, unlike the local closure schemes.The use of the urban Building Environment Parameterization (BEP) significantly improves the simulation of the 2 m temperature during the “jet” evenings and nights, while it entails a further overestimation of the temperature during the “breeze” days leading to a reduction of the bias.

Sunlight Pollution Analysis of Glass Curtain Wall in 3D City

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.