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Research on path loss in indoor stairwells for 5G networks is currently insufficient. However, the study of path loss in indoor staircases is essential for managing network traffic quality under typical and emergency conditions and for localization purpose. This study investigated radio propagation on a staircase where a wall separated the stairs from free space. A horn and an omnidirectional antenna were used to determine path loss. The measured path loss evaluated the close-in-free-space reference distance, alpha-beta model, close-in-free-space reference distance with frequency weighting, and alpha-beta-gamma model. These four models exhibited good compatibility with the measured average path loss. However, comparing the path loss distributions of the projected models revealed that the alpha-beta model exhibited 1.29 dB and 6.48 dB for respectively, at 3.7 GHz and 28 GHz bands. Furthermore, the path loss standard deviations obtained in this study were smaller than those reported in previous studies.

In this study, a set of experiments were carried out in a 21-story full-scale building varying stairwell ventilation state to investigate the fire behavior and smoke temperature distribution in the stairwell. Results demonstrate that the ventilation state of top vents has a great influence on the fire behavior and smoke temperature distribution than the bottom vents. The flame inclines to the stairwell with top vents open during the steady stage, while with top vents closed, it just tilts slightly to the side wall. The mass loss rates and temperature attenuations with top vents closed are larger than those with top vents open. In addition, the open of bottom vents can cause a reduction in the smoke temperature. These unique full-scale experiments provide crucial experimental data that help the design of safer smoke ventilation systems for stairwells in a high-rise building.

The article deals with the issues of ensuring fire safety of multifunctional high-rise buildings and structures. Measures are given to ensure fire safety of multifunctional high-rise buildings and structures. Effective modern methods of improving the safety of using constructive solutions that prevent the spread of fire and the evacuation of people from places covered in flames and smoke by combustion products and blocking access to stairwells are reflected. Since in some cases it is not possible to save people from a burning building in traditional ways, structural solutions are additionally presented that contribute to the safe evacuation of residents of the house. When reviewing existing designs, their shortcomings were identified. The authors proposed a new design of an effective, non-traumatic and safe device for saving people, especially those with low physical fitness and limited physical abilities. It allows you to simplify the design, provide the necessary speed, ensure the availability of evacuation of people with physical disabilities, avoid the presence of auxiliary equipment on a stationary ground object, ensure manufacturability in use, which does not allow, if necessary, to save people from windows and balconies, increase productivity in the “descent-ascent” mode.

Fire in buildings pose a significant threat to occupants, first responders as well as the structural system. Rapid spread of fire and smoke in buildings can hinder the process of evacuation resulting in loss of human life. Such situations call for a reliable egress system that provides safe evacuation of occupants in minimal time. Updating the occupants and first responders with much-needed situational awareness such as accessible stairwells and exits during the disaster can not only lead to efficient evacuation but also shorten the duration of evacuation in some scenarios. This paper examines occupant evacuation scenarios in fire exposed high-rise buildings. A parametric study is carried out on evacuation strategies in a 32-story typical office building during different fire exposure scenarios. The movement of occupants with and without situational awareness is simulated. The effect of critical parameters such as number of stories, width of the egress paths, location and number of exits on the evacuation process is evaluated. The time required for occupants to evacuate the building is estimated under normal conditions (to simulate fire evacuation drill) and under realistic fire exposure. Results from the study indicate that the two most significant factors that influence evacuation time are the location of stairway within the building and the floors at which fire starts. When fire starts at the lower levels of the building, the evacuation time is the highest. More importantly, if situational awareness is incorporated in emergency evacuation procedure, it can improve the evacuation efficiency in a fire exposed high-rise building; wherein up to 24% reduction in evacuation time is achieved.

This paper presents an experimental study of the movements of both ascent and descent in a high occupant density 20-level building in order to exploit the characteristics of occupant movement on long stairwells. The movement processes of the participants are recorded in order to estimate both overall and local movement speeds, as well as flow rate and occupant density in the stairwell. When a merging flow is presented, the average movement time from one floor to the next is 35.8 s ± 15.6 s, and 37.3 s ± 10.6 s for ascent and descent movement, respectively. When a merging flow is not presented, the average movement time per floor is 15.1 s ± 0.8 s and 11.9 s ± 0.8 s for the ascent and descent movement. Under congested conditions, the average speeds on long stairwells maintains a relatively constant value of approximately 0.50 m/s ± 0.17 m/s, and 0.61 m/s ± 0.14 m/s for respective ascent and descent movement, while the traveling distance has no obvious impact on speed. Furthermore, the relationship between velocity and density in our observations is in line with linear functions and equations are accordingly proposed.

This paper documents autonomous multi-floor stairwell ascent by a legged robot. This is made possible through empirically deployed sequential composition of several reactive controllers, with perceptually triggered transitions. This composition relies on simplified assumptions regarding the robot’s sensory capabilities, its level of mobility, and the environment it operates in. The discrepancies between these assumptions and the physical reality are capably handled by the intrinsic motor competence of the robot. This behavior is implemented on the legged RHex platform and experiments spanning 10 different stairwells with various challenges are conducted.

This paper analyzes smoke control strategies in high-rise building stairwells, with particular focus on their application to existing buildings without smoke exhaust openings at the top of the stairwell. This study is necessary to support the optimization of fire safety in a wide range of existing high-rise buildings in Bucharest, Romania, where stairwells operate without upper smoke vents. The scientific challenge addressed is the comparative evaluation of natural ventilation and mechanical pressurization applied at the lower part of the stairwell in order to assess their influence on smoke and heat propagation. The motivation of this work is related to emergency response, as firefighters require a clear understanding of smoke movement and evacuation conditions depending on the fire location and ventilation mode. Three-dimensional CFD simulations were performed, using a fire source validated against experimental data, to analyze temperature, pressure, airflow velocity, visibility, and toxic gas concentration for different fire-floor locations. The results show that natural ventilation alone is ineffective, while single-point mechanical pressurization improves conditions only during the early fire stage. The findings contribute to better-informed firefighter decision-making by clarifying stairwell conditions during intervention in existing high-rise buildings.

Huso discusses Arizona State University's construction of the Rob and Melani Walton Center for Planetary Health, a flagship sustainable research facility in Tempe, AZ. Designed to reflect the harsh desert environment and ASU's goal of carbon neutrality by 2035, the building integrates passive cooling strategies, advanced materials, and site-responsive architecture. Key innovations include glass fiber-reinforced concrete panels modeled after the self-shading saguaro cactus, and voided concrete slabs that reduce material use and structural load. The open-air courtyard, inspired by desert slot canyons, supports airflow and natural cooling, while native plants and a restored canal enhance the microclimate. Fly ash replaced 40% of cement in the concrete mix, further reducing carbon emissions. The design eliminated enclosed stairwells to reduce energy consumption, contributing to a 50% drop in energy use intensity. Completed in 2021, the $156 million project earned LEED-NC Platinum certification and exemplifies holistic, climate-responsive design.

Campus stairwells, characterized by their crowded nature during certain short periods of time, present a high risk for falls that can lead to dangerous stampedes. Accurate fall detection is crucial for preventing such accidents. However, existing research lacks a detection model that balances high precision with lightweight design and lacks on-site experimental validation to assess practical feasibility. This study addresses these gaps by proposing an enhanced fall recognition model based on YOLOv7, validated through on-site experiments. A dataset on campus stairwell falls was established, capturing diverse stairwell personnel behaviors. Four YOLOv7 improvement schemes were proposed, and numerical comparison experiments identified the best-performing model, combining DO-DConv and Slim-Neck modules. This model achieved an average precision (mAP) of 88.1%, 2.41% higher than the traditional YOLOv7, while reducing GFLOPs from 105.2 to 38.2 and cutting training time by 4 h. A field experiment conducted with 22 groups of participants under small-scale populations and varying lighting conditions preliminarily confirmed that the model's accuracy is within an acceptable range. The experimental results also analyzed the changes in detection confidence across different population sizes and lighting conditions, offering valuable insights for further model improvement and its practical applications.