| 1. |
- Anderson, Johan, et al.
(author)
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Investigating machine learning for fire sciences : literature review and examples
- 2021
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Reports (other academic/artistic)abstract
- In this work, a review of current literature on artificial intelligence (AI) and more specifically machine learning (ML) is presented. ML is illustrated by two case studies where artificial neural networks are used for regression analysis of 110 spalling experiments and 81 Fire Dynamics Simulator (FDS) models of tunnel fires. Tunnel fires are often assessed by fire safety engineers using time-consuming simulation tools where a trained model has the potential to significantly reduce time and cost of these assessments.A regression model based on a neural net is used to study small scale spalling experiments and similar accuracy compared to least-square fits are obtained. The result is a function based on 14 determining experimental parameters of spalling and result in, spalling times and depths. It is a relatively small effort to get started and set up models, comparably to regular curve fitting. In this first case study the training times are short, it is thus possible to establish how the model performs on average.The 81 tunnel fire simulations are trained using a similar neural net however it takes considerable time to organize data, creating input, target data of the desired format and training. Here, it is also crucial to normalize the data in order to have it in a suitable format when training. It should be noted that ML is often an iterative process in such a way that it may be difficult to know what settings will work before starting the process. It is equally important to illustrate and get to know the data, e.g., if there are large differences or orders of magnitude differences in the data. A normalization procedure is most often practical and will give better predictions.
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| 2. |
- Arias, Silvia, et al.
(author)
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A Study on Evacuation Behavior in Physical and Virtual Reality Experiments
- 2022
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In: Fire Technology. - : Springer Science and Business Media LLC. - 0015-2684 .- 1572-8099. ; 58:2, s. 817-849
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Journal article (peer-reviewed)abstract
- Comparing results obtained in Virtual Reality to those obtained in physical experiments is key for validation of Virtual Reality as a research method in the field of Human Behavior in Fire. A series of experiments based on similar evacuation scenarios in a high-rise building with evacuation elevators was conducted. The experiments consisted of a physical experiment in a building, and two Virtual Reality experiments in a virtual representation of the same building: one using a Cave Automatic Virtual Environment (CAVE), and one using a head-mounted display (HMD). The data obtained in the HMD experiment is compared to data obtained in the CAVE and physical experiment. The three datasets were compared in terms of pre-evacuation time, noticing escape routes, walking paths, exit choice, waiting times for the elevators and eye-tracking data related to emergency signage. The HMD experiment was able to reproduce the data obtained in the physical experiment in terms of pre-evacuation time and exit choice, but there were large differences with the results from the CAVE experiment. Possible factors affecting the data produced using Virtual Reality are identified, such as spatial orientation and movement in the virtual environment.
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| 3. |
- Forssberg, Martin, et al.
(author)
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The Variation of Pre-movement Time in Building Evacuation
- 2019
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In: Fire Technology. - : Springer Science and Business Media LLC. - 0015-2684 .- 1572-8099. ; 55:6, s. 2491-2513
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Journal article (peer-reviewed)abstract
- In order to provide a reliable evacuation design assessment, data showing the variation in pre-movement time is of vital importance. The pre-movement time is in many cases regarded as the main time period during an evacuation assessment. Therefore, forty unannounced evacuation experiments for six different occupancies were analysed to quantify pre-movement time during building evacuation, i.e., the time taken between receiving the first cue and initiation of movement towards an exit during evacuation. The occupancies were office, cinema theatres, restaurants, department stores and night clubs. The occupancies were equipped with different types of evacuation alarm systems. The study resulted in 2486 data points for the pre-movement time. The pre-movement times were matched to statistical distributions to describe the variation. It was found that the pre-movement times in most cases could be represented with a lognormal or loglogistic distribution typically having a rapid initial increase representing the phase when people start reacting, which is followed by a less steep decrease representing the phase when some people linger before evacuating. Most reliable data are provided for the cinema theatre experiments which included 1954 data points from 30 experiments. The paper also presents a structure for performing an assessment of video recorded evacuation experiment determining actions, relevant time data and fitting a statistical distribution to the data. The new information provided in the paper can help fire safety professionals to more accurately predict the time to evacuate different premises.
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| 4. |
- McNamee, Margaret, et al.
(author)
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Challenges and opportunities for reuse of products and materials with fire safety requirements – A Swedish perspective
- 2023
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In: Fire safety journal. - : Elsevier Ltd. - 0379-7112 .- 1873-7226. ; 140
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Journal article (peer-reviewed)abstract
- The construction sector is of great importance to the Swedish economy, but its impact on the climate is significant and the sector accounts for about 40% of Sweden's total energy consumption. The sector also generates a significant share of the total material flows and waste quantities in the society. Thus, due to the large impact of the construction sector, there are great opportunities to contribute positively by reducing the climate impact through change and modernization. There are many activities focused on reducing construction waste in various ways and the issue of material and product reuse has received increasing attention in recent years. However, very little work has focused on products associated with fire safety requirements. This paper provides an overview of research on the reuse of materials and products with a focus on products with fire safety requirements. In addition, it provides a review of the Swedish building legislation and its impact on the possibility of reusing materials and products with fire safety requirements. Finally, possible paths are explored for introducing more large-scale reuse of such materials and products. © 2023 The Authors
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| 5. |
- Mossberg, Axel
(author)
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Elevator evacuation : Exploring behavioural aspects
- 2022
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Doctoral thesis (other academic/artistic)abstract
- As tall buildings and deep underground structures around the world increase in both numbers and complexity, the issues with evacuation of such structures, e.g., fatigue during evacuation or difficulties for people with functional limitations to evacuate, become more prominent. Elevator evacuation could be a possible solution to these matters but in order for such elevators to be an effective solution for evacuation, they have to be used by the evacuees. Thus, the human behaviour aspects of elevator evacuation, such as willingness to use the elevators and accepted waiting times, are crucial for their effectiveness. The current research aims to increase the knowledge of these aspects in order to improve the possibility to utilise elevator evacuation in buildings and other structures. To achieve this, three different experiments were conducted using different experimental methods and performed in different settings (i.e., high-rise buildings and a virtual underground metro station) to collect human behaviour data on elevator evacuation. The results show that even though there is a general reluctancy towards the use of elevators in a hypothetical evacuation scenario, most people tried to use an elevator to exit in a unnannounced evacuation scenario in a high-rise hotel building. In experiments performed in a virtual underground metro station, the willingness to use evacuation elevators was significantly increased by technical systems, such as information and guidance systems. In a similar manner, longer waiting times were accepted when count-down timers were present above the elevators, showing how long the evacuees had to wait before an elevator would arrive. To help designers consider the uncertainties associated with the behavioural aspects of elevator evacuation, a design strategy is proposed. This strategy can be used when incorporating evacuation elevators in the evacuation design of a building, or other facility.
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| 6. |
- Mossberg, Axel, et al.
(author)
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Evacuation elevators in an underground metro station : A Virtual Reality evacuation experiment
- 2021
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In: Fire Safety Journal. - : Elsevier BV. - 0379-7112. ; 120
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Journal article (peer-reviewed)abstract
- The number of underground metro stations around the world is steadily increasing and deep stations are becoming more common. Evacuation elevators can be a way to mitigate many of the evacuation problems of deep stations, e.g., fatigue. However, the elevators need to be used by evacuees to be effective. In order to study the influence of evacuation measures on elevator usage, experiments were performed in a Virtual Reality (VR) model of a deep underground metro station. Four scenarios with different evacuation measures were studied and compared. These scenarios consisted of a base-line scenario, a scenario with enhanced guidance systems e.g., a more informative voice alarm message and flashing green lights to guide people, a scenario with smartphone guidance and a scenario with timers showing a countdown timer above the elevators. The results show that the use of evacuation elevators is affected by the evacuation system design and that a more informative guidance system can increase evacuation elevator usage. Also, smartphone guidance was shown to increase the elevator usage, but results suggest people stop looking at the smartphone after initiating evacuation. The study also suggests that accepted waiting times for elevators can potentially be increased if countdown timers are installed above elevators.
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| 7. |
- Mossberg, Axel, et al.
(author)
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Evaluating new evacuation systems related to human behaviour using a situational awareness approach – A study of the implementation of evacuation elevators in an underground facility
- 2022
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In: Fire Safety Journal. - : Elsevier BV. - 0379-7112. ; 134
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Journal article (peer-reviewed)abstract
- Elevator evacuation is associated with several safety benefits and can be a cost-efficient evacuation strategy in many buildings or facilities. Despite the advantages, elevator evacuation is not yet a common strategy in the built environment. In this paper, a design strategy that allows the designer to consider information needs of evacuees when designing the information and guidance measures for evacuation elevators is presented. The strategy is based on human behaviour theories and the Theory of Affordance. The use of the design strategy is also illustrated for a case study, i.e., an underground metro station with evacuation elevators. This case study identifies several important measures, which accommodate the information needs of the evacuees, e.g., (1) voice alarm containing information that elevators can be used for evacuation, and (2) a system in the elevator lobby indicating that the elevators are operational. The paper also highlights future research areas where the current level of knowledge related to elevator evacuation needs to increase.
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| 8. |
- Mossberg, Axel, et al.
(author)
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Unannounced Evacuation Experiment in a High-Rise Hotel Building with Evacuation Elevators : A Study of Evacuation Behaviour Using Eye-Tracking
- 2021
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In: Fire Technology. - : Springer Science and Business Media LLC. - 0015-2684 .- 1572-8099. ; 57:3, s. 1259-1281
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Journal article (peer-reviewed)abstract
- Past studies suggest that people are often reluctant to use occupant evacuation elevators in case of fire. However, existing research is scarce and current knowledge is based on questionnaire studies and laboratory experiments. An unannounced evacuation experiment was therefore performed on the 16th floor of a 35-floor high-rise hotel building. Sixty-seven participants took part and eye-tracking glasses were used to collect data on exit choice and eye fixations. Three different scenarios were studied, including two different hotel room locations on the floor and a variation of guidance system for one of these locations, i.e., flashing green lights next to the evacuation sign at the elevators. Results suggest that people typically choose the elevator for evacuation, even if their hotel room was located closer to the evacuation stair. Flashing green lights next to an evacuation sign made people look more at this sign. However, in spite of looking more at the sign, the flashing light was not shown to significantly improve compliance with the sign. Also, the results suggest that a detector activated self-closing fire door without vision panels to the elevator lobby made it more difficult to find the evacuation elevators in an emergency.
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| 9. |
- Mossberg, Axel, et al.
(author)
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Utformning av utrymningssystem i en tunnelbanestation med utrymningshissar : Försök i Virtual Reality-miljö
- 2018
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Reports (other academic/artistic)abstract
- This report summarizes evacuation experiments performed in a Virtual Reality environment. The experiments are performed in a subway station equipped with evacuation elevators. This study is the second step in the process of ensuring the function of new evacuation solutions. The purpose of the study is to investigate if the exit choice in the subway station can be affected by technical way-finding systems. The results of the study show that evacuation elevators are generally avoided in a subway environment. However, with enhancements of way-finding systems the exit choice was affected and the majority of participants in the study attempted to use an evacuation elevator. The results of the study imply that evacuation elevators can be successfully incorporated in a subway environment. However, to ensure a proper implementation, further studies need to be performed.
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| 10. |
- Mossberg, Axel, et al.
(author)
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Utvärdering av informationssystem för utrymning i hotellmiljö - Fältförsök med utrymningshissar
- 2018
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Reports (other academic/artistic)abstract
- This report summarizes unannounced evacuation experiments in a hotel building with evacuation elevators as one of the escape routes. The participants in the experiments were wearing an eye tracking device. The results of the experiments show that there is a high acceptance for using evacuation elevators as an escape route in the evaluated type of high-rise building. The results also show that most evacuees do not see the evacuation signage and when the signage is seen the information conveyed is, in most cases, not perceived. Blinking green lights can be used to improve the probability of seeing the evacuation signage. However, it is not certain that this increases the perception of the information conveyed by the signage.
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