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Search Results (175)

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Keywords = outdoor usage

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27 pages, 24951 KB  
Article
How Urban Activities Respond to Air Pollution: A Multi-Source Geospatial Data Analysis Records
by Taoran Liu, Guangxia Yu, Shuanghua Ye, Jin Qi, Xingru Huang, Zhiwen Zheng, Jin Liu, Stefan Poslad, Xiaoshuai Zhang and Guangyuan Zhang
Geosciences 2026, 16(2), 79; https://doi.org/10.3390/geosciences16020079 - 11 Feb 2026
Viewed by 157
Abstract
Conventional wisdom posits that smog suppresses outdoor activity while shifting peoples’ activities indoors. Using anonymized Mobile Phone Data Provider Records fused with Point-of-Interest (POI) data sourced from the Gaode (Amap) open database for Beijing (2–22 February 2015), we test this substitution hypothesis at [...] Read more.
Conventional wisdom posits that smog suppresses outdoor activity while shifting peoples’ activities indoors. Using anonymized Mobile Phone Data Provider Records fused with Point-of-Interest (POI) data sourced from the Gaode (Amap) open database for Beijing (2–22 February 2015), we test this substitution hypothesis at an hourly resolution across 12 POI-defined activity categories. We estimate the adjusted population density (APD) from mobile phone data via usage-bias calibration, interpolate city-wide AQI (Air Quality Index) and PM2.5 fields, and identify associations with a two-way fixed-effects design (Voronoi polygon (VP), day × hour model. We also handle time-invariant POI activities, while factoring in weather and day types. We find a dual suppression of both outdoor and indoor physical activities: worsening air quality is associated with lower participation in most outdoor and indoor activities. Effects are heterogeneous across categories and hours; shopping shows all-day negative marginal effects, whereas a few categories (e.g., sightseeing) display positive correlations in select afternoon hours consistent with congestion-avoidance rather than health-driven indoor substitution. Quantitatively, a 100-point AQI increase is associated with an order of 1–5 persons/km2 decline at peak hours for most activities. A Comprehensive Impact Index (CII) summarizes the spatial heterogeneity across the city. POI venue operators should anticipate city-wide activity reduction both indoors and outdoors under heavy pollution, rather than plan solely for outdoor-to-indoor activity shifts. Full article
(This article belongs to the Section Climate and Environment)
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28 pages, 20498 KB  
Article
Unveiling Paradoxes: A Multi-Source Data-Driven Spatial Pathology Diagnosis of Outdoor Activity Spaces for Aging in Place in Beijing’s “Frozen Fabric” Communities
by Linyuan Hui, Bo Zhang and Chuanwen Luo
Land 2026, 15(1), 20; https://doi.org/10.3390/land15010020 - 22 Dec 2025
Viewed by 526
Abstract
Against the dual backdrop of rapid population aging and legacy neighborhood renewal, morphologically planning-locked legacy neighborhoods in high-density cities face persistent imbalances in outdoor activity spaces that undermine aging-in-place participation and health equity. This study advances a Spatial Pathology framework. Using nine representative [...] Read more.
Against the dual backdrop of rapid population aging and legacy neighborhood renewal, morphologically planning-locked legacy neighborhoods in high-density cities face persistent imbalances in outdoor activity spaces that undermine aging-in-place participation and health equity. This study advances a Spatial Pathology framework. Using nine representative communities in Longtan Subdistrict, Dongcheng District, Beijing, we develop a GIS-assisted spatial audit, a systematic behavioral observation protocol with temporal-intensity metrics, and a validated perception instrument. These tools form a closed evidentiary loop with explicit indicator definitions, formulas, and decision thresholds, alongside a reproducible analytic and visualization pipeline. Tri-dimensional baselines revealed substantial inter-community disparities: Spatial Quality Index (SQI) ranged from 43.3 to 77.0; activity intensity varied from 1.5 to 15.7 persons/100 m2·hour; and overall satisfaction scores spanned 3.88–4.49. It quantifies and identifies three core paradoxes in outdoor activity spaces within this context: (1) the Functional Failure Paradox with FFI exceeding +0.5 and ELR surpassing 60% in dormant communities; (2) the Value Misalignment Paradox where Facilities & Equipment showed the strongest satisfaction impact (β = 0.344) yet the largest unmet-need gap (VQGI > +8); (3) the Practice–Perception Decoupling Paradox evidenced by a negative correlation (r = −0.38) between usage intensity and satisfaction. These paradoxes reveal the spatial roots of planning-locked legacy neighborhoods—compound mechanisms of planning inertia, decision–demand information gaps, and elderly adaptability masking environmental deficits. We translate the diagnosis into typology-specific prescriptions—reactivating dormant spaces via “route–node–plane” continuity and proximal micro-spaces; decongesting peak periods through elastic zoning and equipment redistribution; and precision calibration of facilities and walking loops—implemented through co-creation and light-touch stewardship. This provides evidence-based, precision-targeted intervention pathways for micro-renewal of aging neighborhoods, supporting localized implementation of UN Sustainable Development Goals (SDG 11 Sustainable Cities; SDG 10 Reduced Inequalities). This methodological framework is transferable to other high-density aging cities, offering theoretical scaffolding and empirical reference for multi-source geographic data-driven urban spatial analysis and equity-oriented age-friendly retrofitting. Full article
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27 pages, 10793 KB  
Article
Thermal Characteristics of Pocket Parks in Hot–Humid Cities Based on Usage Patterns
by Ya Zou, Shuxian Liang, Nan Mo, Feng Shi, Wenjing Liu, Junsong Wang and Qinglin Meng
Buildings 2026, 16(1), 32; https://doi.org/10.3390/buildings16010032 - 21 Dec 2025
Viewed by 270
Abstract
Pocket parks serve as vital everyday green spaces in high-density cities, yet many remain underused, especially in hot–humid regions where thermal discomfort restricts outdoor activities. Traditional pocket-park classification approaches overlook actual usage patterns of pocket parks, and existing studies have not examined whether [...] Read more.
Pocket parks serve as vital everyday green spaces in high-density cities, yet many remain underused, especially in hot–humid regions where thermal discomfort restricts outdoor activities. Traditional pocket-park classification approaches overlook actual usage patterns of pocket parks, and existing studies have not examined whether thermal environments influence pocket park use, nor have they adequately addressed thermal comfort from the perspective of user needs. To address these gaps, this study investigates usage behavior, thermal environments, and thermal comfort demands in pocket parks in Guangzhou, a representative hot–humid city in southern China. Through a preliminary reconnaissance survey, this study selected three typical pocket parks for detailed case-study investigation, and the corresponding usage characteristics were systematically identified. Thermal environments and thermal comfort demands were collected separately through on-site thermal measurements and questionnaire surveys. Correlation and comparative analyses were then conducted to examine the relationships among usage characteristics, thermal environmental conditions, and thermal comfort. The findings reveal that (1) the usage rate of residential pocket parks showed the most sensitivity to WBGT, followed by business pocket parks, while the usage rate of traffic pocket parks showed no significant correlation with WBGT; and (2) business parks had the highest thermal sensitivity with PET, followed by residential and traffic types. A one-unit decrease in TSV corresponds to PET reductions of 11.1 °C, 12.5 °C, and 16.6 °C for business, residential, and traffic parks, respectively; (3) among thermal environmental parameters, wind speed exerted the greatest influence on the subjective thermal responses of users in both residential and business pocket parks. As for usage characteristics, activity type was the most significant factor affecting the thermal sensation of users in the traffic pocket park, while short-term thermal experience played the dominant role for users in the business pocket park. The results of this study offer a scientific basis for user-centered, climate-responsive design strategies for pocket parks in hot–humid regions. Full article
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21 pages, 1358 KB  
Article
Case Study on Shifts in Human Skin Microbiome During Antarctica Expeditions
by Kyu-Chan Lee, Hanbyul Lee, Ok-Sun Kim, Woo Jun Sul, Hyeonah Lee and Hye-Jin Kim
Microorganisms 2025, 13(11), 2491; https://doi.org/10.3390/microorganisms13112491 - 30 Oct 2025
Viewed by 922
Abstract
The human skin microbiome plays a crucial role in maintaining skin health by acting as a barrier against pathogens and modulating immune regulation. This case study investigates the skin microbiome of two healthy Korean male individuals in their 20s during Antarctic expeditions, focusing [...] Read more.
The human skin microbiome plays a crucial role in maintaining skin health by acting as a barrier against pathogens and modulating immune regulation. This case study investigates the skin microbiome of two healthy Korean male individuals in their 20s during Antarctic expeditions, focusing on microbial changes, reversion to pre-expedition states, and the influence of environmental and lifestyle factors. Notable microbial alterations were observed, including increases in Pseudomonadota and decreases in Actinomycetota, indicating pronounced microbial shifts in response to harsh environmental factors such as low temperature and humidity. Post-expedition revealed incomplete recovery to pre-expedition states, with Host A showing a higher resilience index, suggesting faster microbial recovery. Correlation analyses revealed associations between microbial changes and environmental factors (e.g., temperature, humidity, atmospheric pressure) as well as lifestyle factors (e.g., sunblock usage, outdoor activities), highlighting complex interactions between host behaviors and microbiome dynamics. Despite the study’s limited sample size, these findings offer insights into the adaptability and resilience of the skin microbiome under extreme environments, with potential implications for health management and skincare strategies during isolated and prolonged expeditions. Full article
(This article belongs to the Section Microbiomes)
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29 pages, 7146 KB  
Article
Spatial Usage Rate Model and Foot Vote Method for Thermal Comfort and Crowd Behaviour Analysis in Severe Cold Climate City Design
by Siqi Liu and Hong Jin
Buildings 2025, 15(21), 3812; https://doi.org/10.3390/buildings15213812 - 22 Oct 2025
Viewed by 664
Abstract
Understanding the thermal environment of outdoor public spaces is critical for climate-responsive architectural design, evidence-based urban science, and data-driven smart city planning. Thermal comfort shapes both individual decision-making and collective behavioural patterns, offering valuable insights for designing spaces that support year-round vitality. This [...] Read more.
Understanding the thermal environment of outdoor public spaces is critical for climate-responsive architectural design, evidence-based urban science, and data-driven smart city planning. Thermal comfort shapes both individual decision-making and collective behavioural patterns, offering valuable insights for designing spaces that support year-round vitality. This study investigates the relationship between thermal conditions and crowd behaviour in severe cold regions by combining behavioural mapping with on-site environmental measurements. Results show that in high-temperature conditions, spatial distribution is primarily influenced by sunlight and shade, whereas at low temperatures, sunlight has minimal effect on space use. Attendance, duration of stay, and activity intensity follow quadratic relationships with the Universal Thermal Climate Index (UTCI), with optimal values at 29 °C, 26 °C, and 27 °C, respectively. Walking speed is inversely correlated with UTCI, with the fastest speeds observed under cold discomfort, reflecting rapid departure from space. Sitting behaviour peaks at 21 °C UTCI and declines to nearly zero when UTCI is below 10 °C. A comparative analysis between Harbin and other regions reveals significant deviations from temperate zone patterns and greater similarity to subtropical behavioural responses. A key contribution of this study is the introduction of the spatial usage rate model and the foot vote method, two novel, observation-based tools that allow for the objective estimation of thermal comfort without relying solely on subjective surveys. These methods offer architects, planners, and smart city practitioners a powerful evidence-based framework to evaluate and optimise outdoor thermal performance, ultimately enhancing usability, adaptability, and public engagement in cold-climate cities. Full article
(This article belongs to the Section Architectural Design, Urban Science, and Real Estate)
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14 pages, 2520 KB  
Article
Distribution of Airborne Fungi in Vehicles and Its Association with Usage Patterns
by Raúl Asael Rodríguez-Villarreal, Mariana Elizondo-Zertuche, Nydia Orué-Arreola, Juan Adame-Rodríguez, Larissa E. Gordillo-Mata, Miguel González-Enríquez, Brandon Ortega-Castillo, Patricio Adrián Zapata-Morín and Efrén Robledo-Leal
J. Fungi 2025, 11(10), 725; https://doi.org/10.3390/jof11100725 - 10 Oct 2025
Viewed by 783
Abstract
Airborne fungal exposure in confined indoor environments is a growing public health concern, however the microbial composition of air inside private vehicles remains underexplored. This study aimed to characterize culturable airborne fungi in vehicle cabins and evaluate their association with environmental and behavioral [...] Read more.
Airborne fungal exposure in confined indoor environments is a growing public health concern, however the microbial composition of air inside private vehicles remains underexplored. This study aimed to characterize culturable airborne fungi in vehicle cabins and evaluate their association with environmental and behavioral variables. Air samples (100 L) were collected from 69 vehicles using a standardized culture-based method. Simultaneously, a detailed survey was administered to vehicle owners to document usage patterns, maintenance habits, and odor perception. Results revealed a total culturable fungal load of 31,901 CFU/m3, with Cladosporium, Aspergillus, and Penicillium as the most frequently isolated genera. Statistical analysis showed that fungal abundance and community composition were significantly associated with vehicle usage factors such as air disturbance, parking environment, air filter maintenance, and perception of musty odors. Vehicles parked outdoors had significantly higher Bipolaris levels, while lack of regular filter replacement was strongly associated with elevated Alternaria abundance. The presence of musty or moldy odors correlated with a 2.5-fold increase in Aspergillus levels. Redundancy analysis confirmed that odor perception and parking behavior were the strongest predictors of fungal community structure, with specific genera displaying distinct ecological preferences across usage conditions. Usage patterns and maintenance habits significantly influence in-cabin fungal communities, with implications for respiratory health, particularly due to the presence of allergenic and opportunistic genera like Aspergillus, Alternaria, and Bipolaris. Regular air filter maintenance and attention to odor cues may help reduce fungal load and associated health risks. Full article
(This article belongs to the Special Issue Mycological Research in Mexico)
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32 pages, 4634 KB  
Article
Dynamic Energy-Aware Anchor Optimization for Contact-Based Indoor Localization in MANETs
by Manuel Jesús-Azabal, Meichun Zheng and Vasco N. G. J. Soares
Information 2025, 16(10), 855; https://doi.org/10.3390/info16100855 - 3 Oct 2025
Viewed by 758
Abstract
Indoor positioning remains a recurrent and significant challenge in research. Unlike outdoor environments, where the Global Positioning System (GPS) provides reliable location information, indoor scenarios lack direct line-of-sight to satellites or cellular towers, rendering GPS inoperative and requiring alternative positioning techniques. Despite numerous [...] Read more.
Indoor positioning remains a recurrent and significant challenge in research. Unlike outdoor environments, where the Global Positioning System (GPS) provides reliable location information, indoor scenarios lack direct line-of-sight to satellites or cellular towers, rendering GPS inoperative and requiring alternative positioning techniques. Despite numerous approaches, indoor contexts with resource limitations, energy constraints, or physical restrictions continue to suffer from unreliable localization. Many existing methods employ a fixed number of reference anchors, which sets a hard balance between localization accuracy and energy consumption, forcing designers to choose between precise location data and battery life. As a response to this challenge, this paper proposes an energy-aware indoor positioning strategy based on Mobile Ad Hoc Networks (MANETs). The core principle is a self-adaptive control loop that continuously monitors the network’s positioning accuracy. Based on this real-time feedback, the system dynamically adjusts the number of active anchors, increasing them only when accuracy degrades and reducing them to save energy once stability is achieved. The method dynamically estimates relative coordinates by analyzing node encounters and contact durations, from which relative distances are inferred. Generalized Multidimensional Scaling (GMDS) is applied to construct a relative spatial map of the network, which is then transformed into absolute coordinates using reference nodes, known as anchors. The proposal is evaluated in a realistic simulated indoor MANET, assessing positioning accuracy, adaptation dynamics, anchor sensitivity, and energy usage. Results show that the adaptive mechanism achieves higher accuracy than fixed-anchor configurations in most cases, while significantly reducing the average number of required anchors and their associated energy footprint. This makes it suitable for infrastructure-poor, resource-constrained indoor environments where both accuracy and energy efficiency are critical. Full article
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16 pages, 3952 KB  
Article
Analysis of Modifications to an Outdoor Field-Scale Rotating Algal Biofilm Reactor with a Focus on Biomass Productivity and Power Usage
by Davis R. Haag, Phillip E. Heck and Ronald C. Sims
Bioresour. Bioprod. 2025, 1(1), 4; https://doi.org/10.3390/bioresourbioprod1010004 - 19 Sep 2025
Cited by 1 | Viewed by 1149
Abstract
Filtrate from dewatering anaerobically digested biosolids is a side-stream of wastewater treatment that contains high concentrations of nitrogen and phosphorus compounds that can serve as nutrients for cultivating microalgae biomass as biofilms for bioproduct production at Water Resource Recovery Facilities (WRRFs). One system [...] Read more.
Filtrate from dewatering anaerobically digested biosolids is a side-stream of wastewater treatment that contains high concentrations of nitrogen and phosphorus compounds that can serve as nutrients for cultivating microalgae biomass as biofilms for bioproduct production at Water Resource Recovery Facilities (WRRFs). One system used to cultivate attached microalgae biofilms is the rotating algal biofilm reactor (RABR). A pilot RABR with 72 m2 growth surface area, 11.5 m2 footprint area, and a liquid volume of 11,500 L was operated in an outdoor environment at the largest WRRF in Utah, U.S.A, the Central Valley Water Reclamation Facility (CVWRF). The configuration of the RABR was altered from the previous configuration with regard to temperature and duty cycle with the goal to maximize biomass productivity. Results included an increase in dry biomass productivity on a footprint basis from 8.8 g/m2/day to 26.8 g/m2/day (205%) while power requirements changed from 28.3 W to 91 W. The increase in biomass productivity has direct benefits for bioproducts including bioplastic, biofertilizer, and the extraction of lipids for conversion to biofuels. Full article
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28 pages, 2457 KB  
Article
Comparative Analysis of Design Solutions in Terms of Heat and Electricity Demand with Actual Consumption in a Selected Swimming Pool Facility
by Anna Mika, Joanna Wyczarska-Kokot and Anna Lempart-Rapacewicz
Energies 2025, 18(18), 4939; https://doi.org/10.3390/en18184939 - 17 Sep 2025
Viewed by 2368
Abstract
Facilities with high energy demands, such as swimming pools, face escalating costs in electricity and heating, exacerbated by economic instability and fluctuating energy prices. These facilities are often overdesigned to meet extreme peak demands, resulting in higher than necessary energy usage. Therefore, to [...] Read more.
Facilities with high energy demands, such as swimming pools, face escalating costs in electricity and heating, exacerbated by economic instability and fluctuating energy prices. These facilities are often overdesigned to meet extreme peak demands, resulting in higher than necessary energy usage. Therefore, to reduce costs, diversification of heat sources and tailoring their efficiency to meet real-time needs is required. This study analyzes a swimming pool complex in Poland with a sports pool, a recreational pool, an outdoor pool, and a spa bath, comparing the initial design assumptions for the use of heat and electricity with actual consumption data. By incorporating a mix of energy sources, including cogeneration (combined heat and power), gas boilers, district heating, heat pumps, and photovoltaic panels, the system can flexibly adjust to market energy prices. An automated monitoring system continuously monitors energy use, identifies deviations, and helps pinpoint errors, allowing more precise and economical energy management. Detailed reports generated from meter readings enable comparisons with previous usage periods and guide future planning. A balance of energy production with consumption, adjustment of production to match demand, and configuration of equipment operation with defined parameters all contribute to an effective and cost-effective approach to facility energy management. Full article
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30 pages, 11205 KB  
Article
Retiplus: Augmented Reality Rehabilitation System to Enhance Autonomy and Quality of Life in Individuals with Low Vision
by Jonathan José Jiménez, Juan Bayón, María Guijarro, Ricardo Bernárdez-Vilaboa, Rafael Cámara and Joaquín Recas
Electronics 2025, 14(18), 3589; https://doi.org/10.3390/electronics14183589 - 10 Sep 2025
Viewed by 1470
Abstract
Augmented reality features, such as overlaying information in real time, modifying the projected scene, or dynamically adjusting parameters like contrast, zoom, and brightness, show promise in addressing the specific challenges faced by people with low vision. These tailored solutions enhance their visual experiences. [...] Read more.
Augmented reality features, such as overlaying information in real time, modifying the projected scene, or dynamically adjusting parameters like contrast, zoom, and brightness, show promise in addressing the specific challenges faced by people with low vision. These tailored solutions enhance their visual experiences. When combined with mobile technology, these features significantly improve the personalization of visual aids and the monitoring of patients with low vision. Retiplus emerges as a personalized visual aid and rehabilitation system, utilizing smart glasses and augmented reality technology for visual aid functions, along with a mobile app for visual assessment, aid customization, and usage monitoring. This wearable system quickly assesses visual conditions, providing deep insights into the visual perception of patients with low vision. Designed to enhance autonomy and quality of life, Retiplus seamlessly integrates into indoor and outdoor environments, enabling the programming of rehabilitation exercises for both static and ambulatory activities at home. In collaboration with specialists, the system meticulously records patient interaction data for subsequent evaluation and feedback. A clinical study involving 30 patients with low vision assessed the effect of Retiplus, analyzing its impact on visual acuity, contrast sensitivity, visual field, and ambulation. The most notable finding was an average increase of 61% in visual field without compromising ambulation safety. Retiplus introduces a new user-centered approach that emphasizes collaboration among a multidisciplinary team for the customization of visual aids, thereby minimizing the gap between the perceptions of low vision specialists and technologists regarding user needs and the actual requirements of users. Full article
(This article belongs to the Special Issue Applications of Virtual, Augmented and Mixed Reality)
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27 pages, 7467 KB  
Article
Bluetooth Protocol for Opportunistic Sensor Data Collection on IoT Telemetry Applications
by Pablo García-Rivada, Ángel Niebla-Montero, Paula Fraga-Lamas and Tiago M. Fernández-Caramés
Electronics 2025, 14(16), 3281; https://doi.org/10.3390/electronics14163281 - 18 Aug 2025
Viewed by 1577
Abstract
With the exponential growth of Internet of Things (IoT) and wearable devices for home automation and industrial applications, vast volumes of data are continuously generated, requiring efficient data collection methods. IoT devices, being resource-constrained and typically battery-dependent, require lightweight protocols that optimize resource [...] Read more.
With the exponential growth of Internet of Things (IoT) and wearable devices for home automation and industrial applications, vast volumes of data are continuously generated, requiring efficient data collection methods. IoT devices, being resource-constrained and typically battery-dependent, require lightweight protocols that optimize resource usage and energy consumption. Among such IoT devices, this article focuses on Bluetooth-based beacons due to their low latency and the advantage of not requiring pairing for communications. Specifically, to tackle the limitations of beacons in terms of bandwidth and transmission frequency, this article proposes a protocol that modifies beacon frames to include up to three parameters per frame and that allows for making use of configurable beaconing intervals based on the specific requirements of the communications scenario. Moreover, the use of the proposed protocol leads to increased data rates for beaconing transmissions, providing a low latency and a flexible configuration that permits adjusting different parameters. The proposed solution enables end-to-end interoperability in Opportunistic Edge Computing (OEC) networks by integrating a lightweight bridge module to transparently manage BLE advertisement segments. To demonstrate the performance of the devised opportunistic protocol, it is evaluated across multiple scenarios (i.e., in a short-distance reference scenario, inside a home with diverse obstacles, inside a building, outdoors and in an industrial scenario), showing its flexibility and ability to collect substantial data volumes from heterogeneous IoT devices. Full article
(This article belongs to the Special Issue Applications of Sensor Networks and Wireless Communications)
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17 pages, 4705 KB  
Article
Impact of Teachers’ Decisions and Other Factors on Air Quality in Classrooms: A Case Study Using Low-Cost Air Quality Sensors
by Zhong-Min Wang, Wenhao Chen, David Putney, Jeff Wagner and Kazukiyo Kumagai
Environments 2025, 12(8), 253; https://doi.org/10.3390/environments12080253 - 24 Jul 2025
Viewed by 2888
Abstract
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 [...] Read more.
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 PM2.5 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 article belongs to the Special Issue Air Pollution in Urban and Industrial Areas III)
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24 pages, 76230 KB  
Article
Secure and Efficient Video Management: A Novel Framework for CCTV Surveillance Systems
by Swarnalatha Camalapuram Subramanyam, Ansuman Bhattacharya and Koushik Sinha
IoT 2025, 6(3), 38; https://doi.org/10.3390/iot6030038 - 4 Jul 2025
Viewed by 1866
Abstract
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 [...] Read more.
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
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30 pages, 6790 KB  
Article
Exploring the Spatiotemporal Associations Between Ride-Hailing Demand, Visual Walkability, and the Built Environment: Evidence from Chengdu, China
by Rui Si and Yaoyu Lin
Sustainability 2025, 17(12), 5441; https://doi.org/10.3390/su17125441 - 12 Jun 2025
Cited by 3 | Viewed by 2127
Abstract
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 [...] Read more.
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
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20 pages, 781 KB  
Article
Going Green for Sustainability in Outdoor Sport Brands: Consumer Preferences for Eco-Friendly Practices
by Won-Yong Jang and Eui-Yul Choi
Sustainability 2025, 17(10), 4320; https://doi.org/10.3390/su17104320 - 9 May 2025
Cited by 3 | Viewed by 5302 | Correction
Abstract
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 [...] Read more.
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
(This article belongs to the Special Issue Pro-environmental and Sustainable Consumer Behavior)
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