Search Results (164)

This study investigates the impact of teacher decisions and other contextual factors on indoor air quality (IAQ) in mechanically ventilated elementary school classrooms using low-cost air quality sensors. Four classrooms at a K–8 school in San Jose, California, were monitored for airborne particulate matter (PM), carbon dioxide (CO₂), temperature, and humidity over seven weeks. Each classroom was equipped with an HVAC system and a portable air cleaner (PAC), with teachers having full autonomy over PAC usage and ventilation practices. Results revealed that teacher behaviors, such as the frequency of door/window opening and PAC operation, significantly influenced both PM and CO₂ levels. Classrooms with more active ventilation had lower CO₂ but occasionally higher PM_2.5 due to outdoor air exchange, while classrooms with minimal ventilation showed the opposite pattern. An analysis of PAC filter material and PM morphology indicated distinct differences between indoor and outdoor particle sources, with indoor air showing higher fiber content from clothing and carpets. This study highlights the critical role of teacher behavior in shaping IAQ, even in mechanically ventilated environments, and underscores the potential of low-cost sensors to support informed decision-making for healthier classroom environments. Full article

This paper presents a novel video encoding and decoding method aimed at enhancing security and reducing storage requirements, particularly for CCTV systems. The technique merges two video streams of matching frame dimensions into a single stream, optimizing disk space usage without compromising video quality. The combined video is secured using an advanced encryption standard (AES)-based shift algorithm that rearranges pixel positions, preventing unauthorized access. During decoding, the AES shift is reversed, enabling precise reconstruction of the original videos. This approach provides a space-efficient and secure solution for managing multiple video feeds while ensuring accurate recovery of the original content. The experimental results demonstrate that the transmission time for the encoded video is consistently shorter compared to transmitting the video streams separately. This, in turn, leads to about $54\%$ reduction in energy consumption across diverse outdoor and indoor video datasets, highlighting significant improvements in both transmission efficiency and energy savings by our proposed scheme. Full article

Ride-hailing services have reshaped urban commuting patterns, yet the spatiotemporal mechanisms linking built environment features to ride-hailing demand remain underexplored. Existing studies often overlook the joint effects of origin–destination visual walkability. This study integrates ride-hailing GPS trajectories and geospatial data to quantify mobility patterns and built-environment indicators in Chengdu, China. A dual analytical framework combining global regression and localized modeling was applied to disentangle spatial–temporal influences of urban form and socioeconomic factors. The results reveal that population density, floor–area ratio, and housing prices positively correlate with demand, while road density and distance to city center exhibit negative associations. Visual walkability metrics show divergent effects: psychological greenery and pavement visibility reduce ride-hailing usage, whereas outdoor enclosure enhances it. Temporal analysis identifies time-dependent impacts of built environment variables on main urban area travel. Housing price effects demonstrate spatial globality, while population density and city-center proximity exhibit geographically bounded correlations. Notably, improved visual walkability in specific zones reduces reliance on ride-hailing by facilitating sustainable alternatives. These findings provide empirical support for optimizing urban infrastructure and land-use policies to promote equitable mobility systems. The proposed methodology offers a replicable framework for assessing transportation–land-use interactions, informing targeted interventions to achieve metropolitan sustainability goals through coordinated spatial planning and pedestrian-centric design. Full article

The present study investigates consumer preferences for eco-friendly practices implemented by outdoor sport brands, identifying which practices are perceived as most significant among the overall consumer group and within consumer segments differentiated by ecological consciousness. This study targeted consumers who had purchased outdoor sport brand products within the past one to two years. The results indicated that overall consumers regarded ‘Materials usage’, particularly ‘100% organic materials’, as the most critical eco-friendly attribute. The second most significant attribute identified was the ‘Type of campaign’, specifically ‘Consumer behavioral engagement campaigns’. ‘Carbon footprint reduction’, notably ‘Reducing 50% by 2030’, ranked third, while ‘Implementation of donations’ was considered the least important. Segment-specific analysis revealed that high-ecological-conscious consumers prioritized carbon footprint reduction more than other groups. Furthermore, the optimal combination of eco-friendly practices identified for overall and low-ecological-consciousness consumers consisted of using 100% organic materials, implementing consumer behavioral engagement campaigns, reducing carbon footprint by 50%, and actively participating in environmental conservation donations. Highly ecological-conscious consumers preferred a slightly adjusted combination, emphasizing 100% organic materials, followed by reducing carbon footprint by 50%, implementing consumer behavioral engagement campaigns, and actively participating in environmental conservation donations. These findings suggest that outdoor sport brands can strengthen their competitive advantage and sustainability by aligning eco-friendly practices with consumer preferences segmented by ecological consciousness. Full article

In addition to cheap track-etch and expensive research-grade radon monitors, for several years, a new generation of affordable consumer-grade active monitors has been available. Their performance raises the question of whether they could also be used for certain objectives in a scientific context. This requires particular QA/QC as well as understanding their behavior and their limitations. This paper reports experiences with the RadonEye acquired over approximately two years, mainly for recording time series of radon concentration indoors and outdoors. Specific topics include calibration uncertainty, assessed by recording parallel time series; response to thoron by exposing the monitor to thorium-bearing material; and some unresolved questions related to measurement statistics to date. The main results are that factory calibration is quite uncertain and that sensitivity to thoron has to be considered in practical usage. Some identified statistical issues regarding the occurrence of anomalies and possible non-Poisson uncertainty remain unresolved. Full article

The outdoor climate is expected to undergo significant and extreme changes. These changes may lead to increased building requirements depending on their location. This is critical, as human beings tend to spend a large part of their time inside buildings. Accordingly, it is crucial to take future conditions into account to ensure an adequate indoor climate, simultaneously meeting the current drive for decarbonization of the built environment. One avenue is opting for thermally efficient building products and technologies with a lower carbon footprint to guarantee a comfortable indoor climate while minimizing energy consumption. This study focuses on the Northeast region of Brazil, specifically its nine states, given the usage of specific passive thermal strategies in new buildings that have high compensatory energy consumption. This is achieved through developing computational thermal models of a housing unit in a multi-family building, commonly constructed in several cities in this region. This thermal model was employed to analyze indoor thermal comfort, energy consumption, and carbon footprint. To account for future climate projections, the analysis includes scenarios based on Representative Concentration Pathways 4.5 and 8.5. The efficiency of certain sustainable passive rehabilitation is demonstrated in this region, highlighting the importance of adopting passive and efficient thermal measures appropriate to the region’s climate. Full article

The escalating summer heat in the Middle East and Northern Africa (MENA) region, particularly in Bahrain, poses a significant threat to human health, prompting the use of water mist systems for immediate heat stress relief and heat stroke treatment. Although these systems are known for their rapid cooling effects, the impact of varying water temperatures on their efficiency is not well understood. This research addressed this gap by investigating the effects of different water temperatures on cooling performance and user comfort in a semi-outdoor environment in Bahrain. Field experiments, comparing mist fan system (MFS) zones with non-misted areas, were conducted alongside user surveys to assess perceived thermal comfort. The findings revealed that lower water temperatures significantly enhanced cooling, with a 7.7 °C water temperature achieving a 4 °C temperature reduction and improving perceived comfort. The MFS effectively shifted participant perceptions from “Hot” or “Slightly Warm” to “Natural” or “Slightly Cool”, confirming its rapid heat mitigation capabilities. Notably, 54.5% of participants preferred the system using the coldest water, citing immediate relief. Despite the substantial cooling benefits, achieving standard thermal comfort during peak heat remained challenging. Future research should explore nozzle optimization, wind effects, water usage, solar-powered system efficiency, and the impact of clothing on thermal comfort. Full article

In the context of global climate warming, the issue of building energy consumption has become increasingly prominent, with a particular focus on energy management in educational buildings. This study investigates the impact of window usage behaviors in primary school classrooms on building energy consumption, aiming to reveal the dynamic relationship between window-opening behaviors and energy consumption, as well as to propose optimization strategies. A case study was conducted at a primary school, where data on door and window behaviors were collected using wireless smart sensors. Combined with indoor and outdoor environmental monitoring and CFD simulations, this study quantified the impact of window-opening behaviors on building energy consumption. The findings revealed that, in summer, window-opening behaviors exhibited a negative correlation with both indoor and outdoor temperature and humidity. Under high-temperature conditions, individuals tend to close windows to reduce heat entry. In contrast, winter window-opening behaviors showed a positive correlation with indoor and outdoor temperatures, although the probability of opening windows decreased once the temperature exceeded a certain threshold. This study also found that during the winter heating period, energy losses caused by opening external windows were substantial, with daily energy losses amounting to 12.83 kWh. Based on the PMV model, this study proposed an optimization strategy for opening specific windows during winter to maintain thermal comfort. This research provides a scientific basis for the energy-saving design of primary school buildings, helping to reduce energy waste while ensuring indoor comfort and promoting the development of low-carbon campuses. Full article

Heat recovery systems are increasingly recognized as key energy conservation measures in residential buildings. But their effectiveness is highly sensitive to operational conditions. This study used a calibrated OpenStudio simulation, which is validated against monthly utility data, to investigate the feasibility of implementing a heat recovery ventilator in an existing single-detached house in Vancouver under two scenarios: existing passive ventilation without a heat recovery ventilator versus the proposed balanced mechanical ventilation with a heat recovery ventilator. The findings indicate that employing an HRV in an existing house lacking balanced ventilation would lead to higher annual space heating energy consumption (75.49 GJ electricity and 56.70 GJ natural gas with HRV compared to 73.64 GJ and 52.70 GJ, respectively, without an HRV). Therefore, for existing houses without balanced ventilation, improving the existing building envelope’s airtightness through retrofits should always be carried out before installing a heat recovery ventilator. Additionally, the heat recovery ventilator should be appropriately sized to compensate for any shortfall in natural infiltration to ensure the sufficient indoor air quality while minimizing the outdoor air-induced space heating energy usage. Furthermore, the recommended break-even point of the infiltration rate for the house studied in this work to avoid increased space heating energy use due to the retrofit with a heat recovery ventilator is 0.281 air change per hour. Full article

Outdoor thermal environments significantly influence residents’ outdoor activities, yet current urban design often lacks sufficient attention to thermal comfort, and existing design methods remain inadequate. This study addresses these gaps by first demonstrating the crucial impact of outdoor thermal environments on human activity through a combination of field measurements and resident surveys. Using the Yangtze River Delta region as a case study, we propose a set of design optimization strategies based on local residents’ thermal perception characteristics. By conducting a quantitative analysis of local residents’ thermal perception, this study identifies their seasonal thermal comfort needs and translates these insights into refined outdoor space optimization strategies. The results highlight significant seasonal variations in outdoor thermal preferences, with autumn providing the highest satisfaction, followed by winter and summer. Based on these findings, we propose precision-driven design optimizations that align outdoor spatial configurations with residents’ comfort thresholds. Strategies such as dynamic shading arrangements for summer cooling and wind-shielding structures for winter warmth were tailored to actual usage patterns, enhancing the functionality and livability of outdoor spaces. This research offers a data-driven approach to climate-responsive and human-centered residential outdoor space design, providing valuable guidance for urban planners and designers. Full article

Split air conditioning units are crucial for ensuring the thermal comfort of buildings. Conventional scheduling or pre-timed system activities result in high consumption and wasted energy. This study proposes an intelligent control system for automatic setpoint adjustment in an educational building based on real-time indoor and outdoor environmental and room occupancy data. Principal component analysis was used to identify energy consumption components in ramp-up and steady-state power usage scenarios. K-means clustering was then used to categorize environmental scenarios and occupancy patterns to identify operational states, predict power consumption and environmental variables, and generate fuzzy inference system rules. The application of rough set theory eliminated rule redundancy by at least 99.27% and enhanced computational speed by 96.40%. After testing using real historical data from an uncontrolled environment and occupant thermal comfort satisfaction surveys reflecting a range of ACU setpoints, the enhanced inference system achieved daily average power savings of 25.56% and a steady-state power period at 63.24% of the ACU operating time, as compared to conventional and variable setpoint operations. The proposed technique provides a basis for dynamic and data-driven decision-making, enabling sustainable energy management in smart building applications. Full article

Background: West Nile virus (WNV) is a mosquito-borne RNA virus, with birds as reservoirs and humans as incidental hosts. WNV often causes asymptomatic infections, but severe neuroinvasive disease occurs in fewer than 1% of human cases. Recent climatic changes and occupational exposure have increased its spread, particularly in Southern Italy. This study aimed to assess WNV seroprevalence and occupational risks among outdoor workers to guide targeted public health interventions. Methods: This cross-sectional study was conducted in the Apulia region, southeastern Italy, from November 2023 to April 2024. Participants completed a detailed questionnaire on socio-demographics, occupational exposure, travel history, and health symptoms. Blood samples were analyzed using enzyme-linked immunosorbent assay (ELISA) and neutralization assays to detect WNV-specific antibodies. Results: 250 outdoor workers in southeastern Italy were recruited, including agricultural workers, veterinarians, forestry workers, and livestock breeders. The latter showed the highest WNV prevalence at 6.5%. Protective measures such as repellent use (β = −0.145, OR = 0.95, p = 0.019) and personal protective equipment (PPE) usage (β = −0.12, OR = 0.94, p = 0.04) significantly reduced the likelihood of WNV infection. Conclusions: The study highlights the significant occupational risk posed by WNV to outdoor workers involved in livestock breeding in Southern Italy, likely due to their frequent exposure to mosquito-prone environments. Tailored public health strategies and education programs are needed to protect high-risk outdoor workers from WNV, amidst the backdrop of changing climatic conditions that favor increased transmission. Full article

The overarching goal of this research is to evaluate the energy demands and performance of multi-storey cross-laminated timber (CLT) buildings. The research examines the various energy demands influencing the performance of multi-storey CLT buildings. The study addresses the following research question: Can different energy demands influence the performance of CLT buildings? The investigation explores building modeling and simulation under two different weather scenarios to assess these issues. The study considers London Islington and St Albans (Test Reference Year—TRY), due to the proximity of the actual case studies to the reference locations of the weather files. The investigation captures energy demands and performance in the warm season (i.e., May–August). The findings show that the Stadt building (STB) temperatures under the two weather scenarios are warmer by 1.2 °C and 1.6 °C than those of Brid building (BDH) under the same weather conditions. Outdoor dry-bulb temperatures have a lesser impact on radiant temperatures than indoor air temperatures and operative temperatures in the buildings. Solar gains for external windows are influenced by design variables (e.g., building shapes, heights, floor areas, orientations, opening sizes, etc.). The indoor environmental conditions of the buildings under different weather conditions are comfortable, except for BDH St Albans TRY. Occupancy is a major driver influencing domestic hot water (DHW) usage profiles, regardless of the energy sources in the buildings. DHW is a significant parameter determining the overall energy usage in buildings. Other energy usage profiles, such as room electricity, computers and equipment, general lighting, and lighting, can also impact energy usage in buildings. The research outcomes can enhance our understanding of energy usage profiles and possible improvements to enhance the overall performance of CLT buildings. Full article

In this study, we investigate whether differences in sociodemographic and housing characteristics may lead to heterogenous reactions on water demand across households in the event of an unexpected shock. In this sense, we estimate a switching regression model for residential water usage in Gijón, Spain, between 2017 and 2021, exploiting the exogenous impact of the COVID-19 pandemic and various movement restriction phases. A rich dataset that integrates real data on water consumption and pricing, alongside reported household and housing characteristics, allows us to effectively control the heterogeneity of water consumers and test changes in marginal effects over time. Our findings reveal a significant increase in average water consumption coinciding with the onset of the pandemic. This increase in water usage was particularly pronounced among households with more members and those residing in older houses that also owned outdoor amenities such as gardens or swimming pools, among other socioeconomic and housing characteristics. Additionally, our study indicates that the price elasticity of water demand did not significantly differ from zero during the periods of the State of Alarm and the New Normal. This suggests that the implementation of movement restrictions and teleworking may have amplified households’ preferences and dependence on water, thus fostering increased water consumption. Furthermore, our results point towards unchanged residential information or knowledge of the expense of water services despite the time spent at home. Full article

This study proposes an eXtended Reality (XR) glasses-based walking assistance system to support independent and safe outdoor walking for visually impaired people. The system leverages the YOLOv8n deep learning model to recognize walkable areas, public transport facilities, and obstacles in real time and provide appropriate guidance to the user. The core components of the system are Xreal Light Smart Glasses and an Android-based smartphone, which are operated through a mobile application developed using the Unity game engine. The system divides the user’s field of vision into nine zones, assesses the level of danger in each zone, and guides the user along a safe walking path. The YOLOv8n model was trained to recognize sidewalks, pedestrian crossings, bus stops, subway exits, and various obstacles on a smartphone connected to XR glasses and demonstrated an average processing time of 583 ms and an average memory usage of 80 MB, making it suitable for real-time use. The experiments were conducted on a 3.3 km route around Bokjeong Station in South Korea and confirmed that the system works effectively in a variety of walking environments, but recognized the need to improve performance in low-light environments and further testing with visually impaired people. By proposing an innovative walking assistance system that combines XR technology and artificial intelligence, this study is expected to contribute to improving the independent mobility of visually impaired people. Future research will further validate the effectiveness of the system by integrating it with real-time public transport information and conducting extensive experiments with users with varying degrees of visual impairment. Full article