Safe Exit Research Articles

Public perceptions of building seismic safety following the Canterbury earthquakes: A qualitative analysis using Twitter and focus groups

Following the 2010 and 2011 Canterbury earthquakes, the subject of building safety has had a high profile in New Zealand, with building seismic standards coming under scrutiny. Greater public interest in commercial building safety, and policy aims of increasing investment in seismic improvements for disaster risk reduction requires better methods of communicating building risk, and the elements that affect structural damage. Two qualitative analyses were conducted; an analysis of Twitter postings in the immediate wake of the February 2011 event, followed by focus group analyses of perceptions almost two years later. Life-preservation was found to be more important than functionality of buildings, and experience was found to affect the features the public look for to identify “safe” buildings. The most important feature was found to be the provision of safe exits from buildings, rather than design features such as height and materials. Recommendations for better communication of the meaning, benefits and limitations of building seismic standards are made.

Managing Crowds in Hazards With Dynamic Grouping

Emergency navigation algorithms for evacuees in confined spaces typically treat all evacuees in a homogeneous manner, using a common metric to select the best exit paths. In this paper, we present a quality of service (QoS) driven routing algorithm to cater to the needs of different types of evacuees based on age, mobility, and level of resistance to fatigue and hazard. Spatial information regarding the location and the spread of hazards is also integrated into the routing metrics to avoid situations where evacuees may be directed toward hazardous zones. Furthermore, rather than persisting with a single decision algorithm during an entire evacuation process, we suggest that evacuees may adapt their course of action with regard to their ongoing physical condition and environment. A widely tested routing protocol known as the cognitive packet network with random neural networks and reinforcement learning are employed to collect information and provide advice to evacuees, and is beneficial in emergency navigation owing to its low computational complexity and its ability to handle multiple QoS metrics in its search for safe exit paths. The simulation results indicate that the proposed algorithm, which is sensitive to the needs of evacuees, produces better results than the use of a single metric. Simulations also show that the use of dynamic grouping to adjust the evacuees' category, and routing algorithms that have regard for their on-going health conditions and mobility, can achieve higher survival rates.

Modeling the Strategic Behavior of Drivers for Multi-Lane Highway Driving

Current state-of-the-art highway traffic flow simulators rely extensively on models using formulas similar to those describing physical phenomena, such as forces, viscosity, or potential fields. These models have been carefully calibrated to represent the overall flow of traffic and they can also be extended to account for the cognitive limitations of the driver, such as reaction times. However, there are some aspects of driver behavior, such as strategic planning, that are difficult to formulate mathematically. In this article, we describe the YAES-DSIM highway simulator, which integrates virtual physics models with an agent-based model. The virtual physics component models the physical vehicle and the subconscious aspects of the driver behavior, while the agent component is responsible for the strategic and tactical decisions, which are difficult to model using virtual physics. We focus on the lane change decisions of the drivers, with special attention to the optimal lane positioning for a safe exit. We have used the model to simulate the flow of traffic on Highway 408 in Orlando, Florida, and to study the impact of various tactical and strategic decisions on the efficiency and safety of the traffic.

Efficient computation of evacuation routes on a three-dimensional geometric network

We consider a real-time emergency evacuation problem that seeks to compute a set of rapid evacuation routes in a building. Given a three-dimensional geometric structure of the evacuation network, an emergency evacuation route is a sequence of movements of people away from the threat or actual occurrence of a hazard (such as a fire, a hidden bomb) to a safe exit in the network. In such a network each room/crossing/exit in the building is designated as a node and the corridors/staircases/links between the rooms are edges. The evacuation times assigned to the edges are normally distributed random variables. This stochastic routing problem subject to deadline constraints is NP-hard. We provide a new pseudo-polynomial-time dynamic programming algorithm to solve this problem. Based on this algorithm, we construct two types of approximation algorithm, namely a fully polynomial-time approximation scheme providing “almost-optimal” solutions and a fully polynomial-time approximately feasible scheme yielding a best “almost feasible” solution. We present a case study and results of computational experiments to illustrate the working and efficacy of the proposed solution methods, respectively.

Domestic Minor Sex Trafficking: Assessing and Reducing Risk

This exploratory study represents one of the preliminary phases in a larger study conducted in efforts to develop the Domestic Minor Sex Trafficking (DMST) Risk and Resiliency Assessment. The purpose of this study was to examine the factors that may put youth at risk for DMST. Because of Social Works ethical responsibility to marginalized populations, the promotion of protective factors through a 10-session group intervention to counteract against such risks was also explored. Thus, over a three-month period, 10 psychoeducational group interventions were facilitated with 23 runaway, homeless, and street youth (RHSY) at an urban drop-in center with the primary goals of: (a) increasing awareness of healthy versus unhealthy relationship patterns, (b) increasing knowledge on how to set healthy relationship boundaries, (c) increasing the desire and expectation of mental, physical, and sexual respect, and (d) assisting in safe exits from abusive and/or exploitive relationships. Results of the pre-test post-test design indicate a myriad of risk factors for DMST. Findings also support that when provided a psychoeducational intervention within a safe, encouraging, and youth friendly environment, RHSY are able to define and develop protective factors against sex trafficking. Implications are relevant to practitioners and researchers in the field.

An efficient algorithm for computing safe exit points of moving range queries in directed road networks

In this paper, we investigate the problem of computing the safe exit points of moving range queries in directed road networks where each road segment has a particular orientation. The safe exit point of query object q indicates the point at which the safe region and non-safe region of q meet. A safe region indicates a region where the query result remains unchanged provided q remains inside this region. Unfortunately, the existing state-of-the-art algorithm focuses on computing the safe exit points of moving range queries in undirected road networks where every road segment is undirected. What is worse, far too little attention has been paid to moving range queries in dynamic road networks where the network distance changes depending on the traffic conditions. In this paper, we address these problems by proposing an efficient algorithm called CRUISE for computing the safe exit points of moving range queries in directed road networks. Our experimental results demonstrate that CRUISE significantly outperforms a conventional solution in terms of both computational and communication costs.

Experimental Research of the Intelligent Evacuation Inducible System in Building Fire

When a fire or other emergency situation occurs, the intelligent evacuation inducible system is an important means for crowd to evacuate or escape. The factors, such as correct choice of escape routes, to overcome the fear psychology and reasonably avoiding obstacles, have big effects on reaching a safe exit for crowd evacuation. In order to verify the effectiveness of the intelligent evacuation inducible system, a "black house" experiment platform is established in this paper. The time of the fire to reach a dangerous moment is obtained by setting different fire scenarios and using the CFAST method. The actual safe evacuation time is also obtained by several evacuation experiments with different groups of people. According to the time criterion, the interaction mechanism of intelligent evacuation inducible system and crowd evacuation behaviors is analyzed.

Assessing the effectiveness of rip current swimmer escape strategies, Shelly Beach, NSW, Australia

McCarroll, R.J., Brander, R.W., MacMahan, J.H., Turner, I.L., Reniers, A.J.H.M., Brown, J.A. and Bradstreet, A., 2013. Assessing the effectiveness of rip current swimmer escape strategies, Shelly Beach, NSW, Australia .Rip flow dynamics have important implications for swimmer escape strategies, with recent field studies indicating flow is often contained within the surf zone, re-circulating onto shallow bars. Combining physical measurements in a variety of conditions with various escape strategies allows insights into the safest response by individuals caught in a rip. A three day experiment was conducted at Shelly Beach, NSW in December, 2011. Lagrangian measurements of rip flow using GPS drifters were obtained. Participants with attached GPS were deployed in groups of 3 to 5 in rip currents to simulate various escape actions such as floating with the rip current, and swimming in a parallel direction at varying distances from shore. Day 1 and 2 measurements captured an open beach rip current and an adjacent topographic rip current in moderate energy conditions. Day 3 measurements were obtained on an open beach rip current at a more exposed section of the beach under higher energy conditions. Results were analysed by duration and assessed as being either (i) positive outcome (high chance of safe exit); or (ii) negative outcome (greater potential for hazard). Mean durations were Float (4 min), and Swim (2 min). Of the eight escape scenarios tested, half had potential negative outcomes, including 2 of 3 Float options and 2 of 5 Swim options. Negative outcomes for Floats were related to surf zone exits, and multiple circulations. Negative outcomes for Swims related to swimming against longshore directed circulation. Neither strategy was clearly more likely to result in a successful outcome across all scenarios. Further investigations are currently being conducted in a greater range of hydrodynamic and morphological conditions.

A safe exit algorithm for continuous nearest neighbor monitoring in road networks

Query processing in road networks has been studied extensively in recent years. However, the processing of moving queries in road networks has received little attention. In this paper, we introduce a new algorithm called the Safe Exit Algorithm SEA, which can efficiently compute the safe exit points of a moving nearest neighbor NN query on road networks. The safe region of a query is an area where the query result remains unchanged, provided that the query remains inside the safe region At each safe exit point, the safe region of a query and its non-safe region meet so that a set of safe exit points represents the border of the safe region. Before reaching a safe exit point, the client query object does not have to request the server to re-evaluate the query This significantly reduces the server processing costs and the communication costs between the server and moving clients. Extensive experimental results show that SEA outperforms a conventional algorithm by up to two orders of magnitude in terms of communication costs and computation costs

A Safe Exit Algorithm for Continuous Nearest Neighbor Monitoring in Road Networks

Query processing in road networks has been studied extensively in recent years. However, the processing of moving queries in road networks has received little attention. In this paper, we introduce a new algorithm called the Safe Exit Algorithm (SEA), which can efficiently compute the safe exit points of a moving nearest neighbor (NN) query on road networks. The safe region of a query is an area where the query result remains unchanged, provided that the query remains inside the safe region At each safe exit point, the safe region of a query and its non-safe region meet so that a set of safe exit points represents the border of the safe region. Before reaching a safe exit point, the client (query object) does not have to request the server to re-evaluate the query This significantly reduces the server processing costs and the communication costs between the server and moving clients. Extensive experimental results show that SEA outperforms a conventional algorithm by up to two orders of magnitude in terms of communication costs and computation costs.

The Questionnaire of Influence Factors in the Commercial Building Evacuation

Abstract Characteristics of different personnel have different reactions when faced fire. As large passenger flow and rich personnel types within commercial building, this paper adopt single factor variable analysis method, through the way of questionnaire analysis of social role, type, whether or not accept the training and other single factor of passengers in the commercial buildings variation on evacuation behavior. The survey results show that: the role of passengers on evacuation behavior is more worker selection confirmation of fire or try to put out the fire, while more customers choose escape. The types of passengers on evacuation behavior is more adult women, the elderly and children choose escape immediately, while adult men try to extinguish the fire; when the exit is crowed, the elderly and children choose waiting for in situ, while adult men and women choose to ease crowd evacuation for a much higher percentage than other types of passengers. Training and exercises on evacuation behavior is received fire drill or training passengers choose the nearest safe exit evacuation and active guidance of crowd evacuation in a significantly higher than the proportion of did not received.

A safe exit algorithm for continuous nearest neighbor monitoring in road networks

Query processing in road networks has been studied extensively in recent years. However, the processing of moving queries in road networks has received little attention. In this paper, we introduce...

A novel method for planning a staged evacuation

This paper presents an innovative method to facilitate making such a plan. Using an algorithm to schedule the starting time of each evacuation group, the method guarantees that the time of completing a large-scale evacuation is very close to its theoretically shortest evacuation time. Meanwhile, unlike a simultaneous evacuation, during a staged evacuation planned with the proposed method, all evacuees can take the shortest path to a safe exit. Once evacuees start off, they will not suffer any traffic congestion. The above advantages of this innovative method are achieved by using an algorithm with three nested loops. Experiments have been conducted, and their results have validated the proposed method.

Crowd Evacuation for Indoor Public Spaces Using Coulomb’s Law

This paper focuses on designing a tool for guiding a group of people out of a public building when they are faced with dangerous situations that require immediate evacuation. Despite architectural attempts to produce safe floor plans and exit door placements, people will still commit to fatal route decisions. Since they have access to global views, we believe supervisory people in the control room can use our simulation tools to determine the best courses of action for people. Accordingly, supervisors can guide people to safety. In this paper, we combine Coulomb’s electrical law, graph theory, and convex and centroid concepts to demonstrate a computer-generated evacuation scenario that divides the environment into different safe boundaries around the locations of each exit door in order to guide people through exit doors safely and in the most expedient time frame. Our mechanism continually updates the safe boundaries at each moment based on the latest location of individuals who are present inside the environment. Guiding people toward exit doors depends on the momentary situations in the environment, which in turn rely on the specifications of each exit door. Our mechanism rapidly adapts to changes in the environment in terms of moving agents and changes in the environmental layout that might be caused by explosions or falling walls.

Uncertainty Characterization in the Design of FlowDiversion Structure Profiles Using Genetic Algorithm and Fuzzy Logic

Flow diversion head works are constructed across rivers to divert flow into irrigation, navigation, or power generation channels. Hydraulic structures, such as weirs or barrages, are integral parts of these diversion head works. The optimal design of these hydraulic structures is generally obtained by considering the deterministic values of hydrogeological parameters. However, there is a high degree of local soil variability and imprecision in the determination of soil parameters, such as the safe exit gradient. The seepage head also exhibits a high degree of variability, depending on complex hydrological and metrological factors. This work considers the hydrogeological parameters safe exit gradient and seepage head as imprecise or uncertain. An optimization-based methodology is presented to incorporate uncertainty in the safe exit gradient and seepage head in the optimization formulation and obtain the optimum structural dimensions that minimize the total cost. The subsurface flow consideration is embedded in the optimization formulation. The nonlinear optimization formulation (NLOF) solution procedure using a genetic algorithm (GA) is implemented to demonstrate the characterization of uncertainty in design and hence, overall cost from the uncertain safe exit gradient and seepage head. The limited evaluation shows the potential applicability of the proposed methodology.

Spatial Computers for Emergency Support

We present two spatially distributed computing systems that operate in a building and provide intelligent navigation services to people for evacuation purposes. These systems adapt to changing conditions by monitoring the building and using local communication and computation for determining the best evacuation paths. The first system, called distributed evacuation system (DES), comprises a network of decision nodes (DNs) positioned at specific locations inside the building. DNs provide people with directions regarding the best available exit. The second system, called opportunistic emergency support system (OESS), consists of mobile communication nodes (CNs) carried by people. CNs form an opportunistic network in order to exchange information regarding the hazard and to direct the evacuees towards the safest exit. BothDESandOESSemploy sensor nodes deployed at fixed locations for monitoring the hazard.We evaluate the spatial systems using simulation experiments with a purpose-built emergency simulator called DBES.We show how parameters such as the frequency of information exchange and communication range affect the system performance and evacuation outcome.

Life Safety Evacuation for Cross Interchange Subway Station fire

Fire accidents in a cross interchange subway are analyzed. At present, the primary focus of subway evacuation behavior analysis is mainly concern on normal state; evacuations in case of fire have rarely been under research. The relationship of soot density and extinction coefficient of fire smoke with average walking speed of occupants is linearly dependent. In this paper, FDS+Evac program is used to simulate the evacuation in a fire scenario. It has been found that not only some occupants’ evacuation routes become longer, but also the utilization of some of the exits is reduced, therefore congestion is caused at other safe exits in a cross subway station fire.

Sky compass orientation in diurnal and nocturnal dung beetles

Event Abstract Back to Event Sky compass orientation in diurnal and nocturnal dung beetles Basil El Jundi1*, Jochen Smolka1, Emily Baird1, Marcus Byrne2, Marie Dacke1 and Eric Warrant1 1 University of Lund, Department of Biology, Sweden 2 University of Witwatersrand, Department of Biology, South Africa To escape from the intense competition at the dung pile, ball-rolling dung beetles have developed a unique and simple orientation behavior in which they roll a dung ball away from the dung pile in a straight line. To keep this straight path, dung beetles use celestial compass cues such as the sun, the moon and the pattern of polarized light formed around these sources (Dacke et al., 2003, Nature, 424: 33). These sky compass cues provide all the precision these insects need to ensure a safe exit from the dung pile. However, whether the relevance of individual sky compass signals varies between diurnal and nocturnal dung beetle is still an open question. Furthermore, nothing is known concerning the neural substrate that allows nocturnal dung beetles to orientate at light levels a million times dimmer than those that allow orientation in their diurnal relatives. To investigate these questions, we analyzed the orientation performance in a diurnal (Scarabaeus nigroaeneus) and a nocturnal (S. satyrus) beetle species to celestial compass signals, both in the laboratory and in their natural habitat in South Africa. We tested whether a change in the orientation of polarized light in the laboratory or a shift of the plane of skylight polarization in the field affects the rolling bearing of the beetles. In addition, we studied how beetles change their bearing in response to a 180° reflection of the sun. Finally, we used a combination of immunohistochemistry, confocal microscopy and 3D reconstruction of different brain areas to show how nocturnality affects the neuroanatomy of the dung beetle brain. Our data show that both diurnal and nocturnal dung beetle species use patterns of polarized light (either artificial or from the sun/moon) and the sun/moon in a similar way for straight line orientation. While brain areas in the optic lobes are remarkably larger in the nocturnal species compared to the diurnal species, our preliminary data suggest that, in the central brain, the relative volumes of brain areas dedicated to visual processing are similar. These results indicate that sky compass signals in the brain of nocturnal beetles converge more strongly towards late processing stages and thus, could lead to a greater sensitivity in dim light conditions. Keywords: Anatomy, Behavior, dung beetle, Insect brain, insect navigation, Orientation, polarized light, sky compass signals Conference: Tenth International Congress of Neuroethology, College Park. Maryland USA, United States, 5 Aug - 10 Aug, 2012. Presentation Type: Poster (but consider for student poster award) Topic: Orientation and Navigation Citation: El Jundi B, Smolka J, Baird E, Byrne M, Dacke M and Warrant E (2012). Sky compass orientation in diurnal and nocturnal dung beetles. Conference Abstract: Tenth International Congress of Neuroethology. doi: 10.3389/conf.fnbeh.2012.27.00231 Copyright: The abstracts in this collection have not been subject to any Frontiers peer review or checks, and are not endorsed by Frontiers. They are made available through the Frontiers publishing platform as a service to conference organizers and presenters. The copyright in the individual abstracts is owned by the author of each abstract or his/her employer unless otherwise stated. Each abstract, as well as the collection of abstracts, are published under a Creative Commons CC-BY 4.0 (attribution) licence (https://creativecommons.org/licenses/by/4.0/) and may thus be reproduced, translated, adapted and be the subject of derivative works provided the authors and Frontiers are attributed. For Frontiers’ terms and conditions please see https://www.frontiersin.org/legal/terms-and-conditions. Received: 30 Apr 2012; Published Online: 07 Jul 2012. * Correspondence: Dr. Basil El Jundi, University of Lund, Department of Biology, Lund, Sweden, basil.el.jundi@ntnu.no Login Required This action requires you to be registered with Frontiers and logged in. To register or login click here. Abstract Info Abstract The Authors in Frontiers Basil El Jundi Jochen Smolka Emily Baird Marcus Byrne Marie Dacke Eric Warrant Google Basil El Jundi Jochen Smolka Emily Baird Marcus Byrne Marie Dacke Eric Warrant Google Scholar Basil El Jundi Jochen Smolka Emily Baird Marcus Byrne Marie Dacke Eric Warrant PubMed Basil El Jundi Jochen Smolka Emily Baird Marcus Byrne Marie Dacke Eric Warrant Related Article in Frontiers Google Scholar PubMed Abstract Close Back to top Javascript is disabled. Please enable Javascript in your browser settings in order to see all the content on this page.

Seasons of Change: Arab Spring and Political Opportunities

Seasons of Change: Arab Spring and Political Opportunities

A safe-exit approach for efficient network-based moving range queries

Query processing on road networks has been extensively studied in recent years. However, the processing of moving queries on road networks has received little attention. This paper studies the efficient processing of moving range queries on road networks. We formulate a network-based concept called safe exits that guarantee the query result of the client remains unchanged before the client reaches any exit. This significantly reduces the communication overhead between moving clients and the server. We then develop an efficient algorithm for computing safe exits for a client on-demand. We evaluate the proposed techniques using real road network data. Experimental results show that our algorithm constructs safe exits efficiently and they effectively reduce the communication cost.