Exit Location Research Articles

Optimizing crowd evacuation: evaluation of strategies for safety and efficiency

Predicting and controlling crowd dynamics in emergencies is one of the main objectives of simulated emergency exercises. However, during emergency exercises, there is often a lack of sense of danger by the actors involved and concerns about exposing real people to potentially dangerous environments. These problems impose limitations in running an emergency drill, harming the collection of valuable information for posterior analysis and decision-making. This work aims to mitigate these problems by using Agent Based Modelling (ABM) simulator to deepen the comprehension of human actions when exposed to a sudden variation in extensive crowded environmental conditions and how evacuation strategies affect evacuation performance. To assess the impact of the evacuation strategy employed, we propose a modified informed leader-flowing approach and compare it with common evacuation strategies in a simulated environment, replicating stadium benches with narrow corridors leading to different exit points. The objective is to determine the impact of each set of configurations and evacuation strategies and compare them against other established ones. Our experiments determined that agents following the crowd generally lead to a higher number of victims due to the rise of herding phenomena near the exits, which was significantly reduced when agents were guided towards the exit via knowing the exit beforehand or following leader agent with real-time information regarding exit location and exit current state, proving that relevant and controlled information in combination with Follow Leader strategies can be crucial in an emergency evacuation scenario with limited evacuation exit capabi and distribution.

The Impact of Dependent Behavior on the Design of Classroom Evacuation Exits for Intellectually Disabled Students

The increasing demand for special education in architectural design highlights the urgent need to ensure the safe evacuation of students with intellectual disabilities. However, current research on classroom evacuation for these students remains limited, particularly concerning critical factors, such as the number, location, and distance of exits. This study investigated the impact of dependent behavior on classroom exit design for students with intellectual disabilities by developing a Cellular Automaton (CA) model based on their behavioral characteristics. Simulated evacuation scenarios, considering and disregarding dependent behaviors, were analyzed to assess their effects on the number and positioning of exits, and a predictive model was implemented to establish the relationship between exit spacing and evacuation time. The results indicated that the dependent behavior significantly reduced evacuation efficiency and substantially affected classroom exit design. Considering the dependent behavior, this study demonstrated that setting two exits reduced the average evacuation time for students with intellectual disabilities by 12.99%, with further reductions achieved by placing the exits at the rear rather than at the sides or front of the classroom. The research also revealed that under the influence of dependent behavior, the average evacuation time initially decreased and then increased as the distance between exits increased. As one of the few studies addressing evacuation issues for students and the first to incorporate dependent behavior into the evacuation model, this study provides valuable recommendations for classroom designs that balance evacuation safety and daily usability. It offers essential data to inform architectural designs for classrooms serving students with intellectual disabilities and serves as a reference for future educational building design standards and regulations.

Radiographic acceptable zone of endobutton placement in ACL reconstruction: A prospective study.

During the transportal technique of anterior cruciate ligament (ACL) reconstruction, tunnel outlet location can be varied depending on certain anatomical and technical characteristics. Therefore, we aimed to find out the acceptable zone of endobutton location by introducing several radiographic values. Postoperative lateral radiographs of 72 patients were assessed to measure the distances from the centre of the button to the posterior femoral cortex (D1) and to the most distal point of the lateral condyle (D2). Furthermore, based on the anteroposterior (AP) radiographs, the distances from the centre of the button to the lateral femoral cortex (D3) and from the centre of the button to the line connecting the most distal points of the medial and lateral femoral condyles (D4) were assessed. To measure the sensitivity and specificity of each radiographic value (D1, D2, D3 and D4), the area under the receiver operating characteristic curve was calculated. The alpha angle and femoral tunnel length values were considered as gold standards. Analyses showed that the mean values for D1, D2, D3 and D4 were 13.20 ± 0.54, 39.44 ± 0.31, 1.65 ± 0.15 and 42.66 ± 0.47 mm, respectively. The mean angle was found to be 38.6 ± 0.3°, and the mean femoral tunnel length was 38.6 ± 0.2 mm. Age was significantly related to D2 and the diameter of the femur in AP X-ray, while body mass index had a significant relation with D3 (p < 0.05). In this study, a new method was proposed to evaluate the accuracy of anatomical tunnel placement in ACL reconstruction surgery postoperatively. The statistical analysis of the measured variables showed that the mean ratios were 21.79 ± 0.87 for D1, 65.65 ± 0.63 for D2 and 51.90 ± 0.73 for D4. The results indicated that if the tunnel exit location and endobutton placement in the postoperative radiological images fall within the suggested areas, it can be meaningfully concluded that the tunnel is correctly positioned intraarticularly and the ligament reconstruction is anatomical. Level III.

Comparative Study of SFPE and Steering Modes in Pathfinder to Optimise Evacuation Routes

This paper investigates the possibilities of using an agent-based evacuation model to analyse the formation of queues at the exits of enclosed spaces and the evacuation process of people. The aim is to investigate how the density of people in a crowd affects the safe movement of people and how the width, number, and location of exits affect evacuation time. The analysis was carried out using the Pathfinder evacuation model, which provides two modes to simulate the movement of people: steering and SFPE. An enclosed space of 20 m × 30 m was investigated. First, the differences between the modes of the evacuation model to simulate the movement of people were compared. Then, the steering mode with limited door flow was set and the effect of the width, number, and location of the exits with a total width of 4 m on the evacuation time was investigated. The results of this study highlight differences in the simulation of the movement of people according to the different modes and provide valuable information for the design of safe escape routes. Proper design of escape routes can prevent an adverse situation that could arise when evacuating a large number of people.

Observational study on the identification of left atrial tachycardia circuits using Local Activation Time Histogram.

Mapping of atypical atrial arrythmias arising in the left atrium is often challenging. The Local Activation Time (LAT) Histogram, a new function of the 3D color mapping system CARTO version 7, may help improve identification of atrial tachycardia circuits. We aimed to assess the effectiveness of the LAT Histogram for identification of left atrial tachycardia circuits. This retrospective study compared 25 consecutive cases of left atrial tachycardia that were treated before use of LAT Histogram (unused group) and 25consecutive cases that were treated after introduction of LAT Histogram (used group) at Nagano Chuo Hospital. We evaluated whether we could identify the circuit of left atrial tachycardia from the electrophysiology lab data during ablation and the CARTO system data and whether we could perform effective ablation. Door-to-door time, skin-to-skin time, and fluoroscopy time (p≤.011) were all shorter in the LAT Histogram used group versus unused group, while mapping analysis times were longer in the used group (p ≤.019). A significantly greater number of cases in the LAT Histogram used compared with the unused group had ablation for entrance or exit points (19vs. 10 cases; p=.001 for first map). Ablation resulted in a return to sinus rhythm and changed cycle length at the first mapping in 20 cases (80%) in the LAT Histogram unused group and in 24 cases (96%) in the used group. LAT Histogram may provide a simple and effective method to identify entrance and exit locations in left atrial tachycardia.

Optimal time interval of information update using by exit-choice system to improve pedestrian evacuation efficiency

In the case of emergency evacuation of large places, the rapid evacuation of pedestrians has always been a matter of great concern. However, research on pre-movement behavior and decision-making fatigue behavior of pedestrians in emergency evacuation situations is limited. In order to study how to improve evacuation efficiency under the introduction of exit-choice system, this paper uses the cellular automata model to simulate different exit arrangements and exit numbers at different time intervals of information update by the system. It is found that there is an optimal time interval of information update when three exits of a room have different widths, and the evacuation time significantly reduces compared to real-time update. The potential mechanism of the optimal time interval of information update is that the evacuees can be reasonably allocated to each exit, so that the passage capacity of each exit can be maximized, and the evacuation time is significantly reduced. Sensitivity analysis shows that the change of exit location has an important influence on the evacuation time. The different pre-movement times of pedestrians have a certain degree of influence on the evacuation time of real-time update. The different distance parameters and flow parameters had a significant impact on the evacuation time in the real-time update case.

Computed Tomography Evaluation of Frontal Sinus Volume in Migraine Patients.

This study aimed to assess the frontal sinus volume (FSV) on computed tomography (CT) scans in migraine patients. Cranial and paranasal CT images from 75 migraine patients (mean age: 39.14±13.63y) and 23 control cases (mean age: 38.78±13.32y) were analyzed retrospectively. Three-dimensionally reconstructed images of frontal sinuses were generated. Total FSV, anterolateral, and transverse diameters of the head were measured. The presence/absence and nature of supraorbital foramen and notches were evaluated. The total FSV was 8.02±5.97cm 3 in the migraine group and 8.38±4.83cm 3 in the control group, with no significant differences between them. Mean FSV values showed no statistically significant difference between females (7.79±5.85cm 3 ) and males (9.12±6.66cm 3 ) within and between the groups. Single notch was the most observed structure in both groups, with bilateral presence being the most common. Double foramen and notch were observed only in the migraine group, and the coexistence of both structures was higher in the migraine patients than in controls. There was no statistical difference in FSV between migraine and control groups, nor based on sex. Overall, the frontal region anatomy, particularly the exit locations of the supraorbital or supratrochlear foramen/notches, may be influenced by hyperplasia/hypoplasia of FSV. Therefore, assessing FSV using CT may be crucial for surgical planning in migraine patients undergoing open or endoscopic approaches to the frontal region.

A numerical simulation-based solution for enhancing the safety evacuation of the high-rise complex in geriatric hospital

Due to the vulnerability of the elderly population and the specificity of the treatment environment, geriatric hospitals face more serious fire safety issues than ordinary medical buildings. Existing conclusions are mostly one-sided as researchers have mainly ignored the diversity of geriatric patients and the types of functional rooms in the buildings. To make the findings in this field completer and more adequate, a geriatric hospital high-rise was employed as a case study and simulated in Pathfinder software. This model evaluated the efficacy of hierarchical organization of evacuating crowds, modification of vertical functional zoning, and specific congestion mitigation measures. The synthesized outcomes from these evaluations informed the development of an integrated evacuation strategy. Output parameters were used in place of control variables to verify repeatability. Crowd prioritization improve evacuation efficiency by optimizing the evacuation sequence and reducing the crossing of people; vertical functional zoning modification avoid congestion by locating high-risk departments near the bottom, for example; and blockage point evacuation enhance evacuation speed by adjusting the location of exits and improving the design of staircases. This comprehensive strategy successfully reduces evacuation time by 28.8 % and can be used as a guideline for a generic evacuation optimization system for similar buildings.

Development of a time pressure-based model for the simulation of an evacuation in a fire emergency

The study of pedestrian behaviour in a fire emergency is essential for effectively reducing the number of casualties. However, most studies only consider the effect of fire on pedestrian behaviour and ignore the effect of a fire emergency on pedestrian psychology. In this study, we introduce a method of assessing the pedestrian time pressure within a cellular automaton model using the available safe egress time and required safe egress time in fire evacuations. Moreover, a more realistic reflection of the evacuation process in a fire emergency is obtained by introducing Pyrosim to compute the fire floor field and by proposing a sequential update method based on time pressure. To assess the model, we conduct sensitivity analyses on model parameters across various environmental configurations. Numerical simulation results show that fire accelerates the evacuation rate and radiated heat transfer and temperature have the greatest effects on the time pressure of pedestrians in a fire evacuation. The distribution of pedestrians is U-shaped owing to fire avoidance behaviour and in the later stage of evacuation, pedestrians keeping away from heated walls. The trend of time pressure over time has a bimodal distribution as pedestrians initially pass the fire and the environment then becomes untenable as the fire fully develops. In addition, the exit location affects the evacuation process, with a symmetrical positioning improving the evacuation efficiency. We verify the model in a series of physical experiments. The agreement between the numerical simulation results and experimental results demonstrates that the time pressure-based model is suitable for simulating the route choice behaviour and evacuation process in fire emergencies.

COST PERFORMANCE ANALYSIS USING EARNED VALUE METHOD ON PRESERVATION OF EXIT TOLL ROAD SECTION 5 PANDAAN MALANG

The development of road or toll road infrastructure in a country can be used as a benchmark to determine the level of economic progress of a country, both macro and micro. The location of toll exits has a significant effect in absorbing labor and creating new business activities. Projects are dynamic, so contractors must be responsive to changes in situations and conditions on the project, if they want to succeed in reaping optimum profits. Aspects of planning a highly competitive construction at this time are very demanding on accuracy, effectiveness, efficiency, and economy in analyzing a project. In the world of construction projects, there are many things that can be done, one of which is cost control. In controlling costs, efforts can be made so that the realization of costs that occur is in accordance with the needs of implementation and is not excessive, such as cost suppression efforts, namely making savings without reducing quantity or quality. The Earned Value Method is used to determine project performance in terms of costs at one time, determine project performance in terms of schedule/time at one time, estimate costs to complete the project after the evaluation time and estimate the time to complete the project after the evaluation. In this research the author carried out a cost analysis using the Earned Value Method on the preservation of the Section 5 Pandaan Malang Toll Exit Road.

Numerical study on thermal hydraulics characteristics during steam submerged jet condensation from rectangular CD nozzle

The phenomenon of steam-water direct contact condensation (DCC) has significant importance in nuclear industry due to its rapid and efficient heat and mass transfer rates. In this numerical study, three dimensional simulations of steam submerged jet condensation from rectangular converging-diverging (CD) nozzle into subcooled water has been investigated. The steam condensation phenomenon has been captured from thermal phase change model as user defined function (UDF) in ANSYS Fluent software. The computational results were validated using experimental results as well as previously published numerical study. The effects of steam pressure and water temperature on distributions of various thermal hydraulics parameters including velocity, pressure, temperature, heat and mass transfer characteristics have been studied. The steam pressure and water temperature have been kept in the range of 200–500 kPa and 20–60 °C, respectively. The maximum value of jet velocity and heat transfer coefficient have been found as 803 m/s and 2.73 MW/m2K respectively. The peak velocity value increases with steam pressure. After maximum expansion point, the velocity profile curve is shifted downstream with steam pressure. The axial pressure distribution first decreases and then increases from expansion-compression waves. The axial temperature profile followed the similar trend as observed for axial steam pressure distribution. At constant steam pressure, the maximum rate of heat transfer coefficient decreases with the increase in water temperature. The maximum mass transfer rate under prescribed flow conditions has been found as 2789.8 kg/m3s. The peak mass transfer rate decreases with steam pressure and water temperature. The peak rates for heat and mass transfer have been observed in the nearby vicinity of nozzle exit location.

Moment-SOS hierarchy and exit location of stochastic processes

Moment-SOS hierarchy and exit location of stochastic processes

Computing exit location distribution of stochastic dynamical systems with noncharacteristic boundary based on deep learning

Rare events induced by random perturbations are ubiquitous phenomena in natural systems, where the exit location distribution is a significant quantity, and its computation is challenging. In this study, we compute the exit location distribution of stochastic dynamical systems with weak Gaussian noise for a noncharacteristic boundary based on deep learning and large deviation theory. First, we introduce the perturbation expressions of the prefactor and exit location distribution via Wentzel–Kramers–Brillouin approximation. We then design a deep learning method to compute the quasipotential, the prefactor, and the exit location distribution. Two examples are described to verify the effectiveness of the proposed algorithm. The findings of this study are expected to provide valuable insights into exploring the mechanisms of rare events triggered by random fluctuations.

Central retinal vessel trunk exit location: An important factor while evaluating the neuroretinal rim.

Optic nerve head (ONH) evaluation plays a key role in differentiating normal from glaucomatous disk. Thinning of the inferior neuroretinal rim (NRR) has been noted in early glaucoma. However, NRR thickness in different quadrants appears to depend on various factors including central retinal vessel trunk exit (CRVT) position. We evaluated ocular parameters that determined the NRR thickness in the different quadrants of normal eyes. Retrospective review of demographic and ocular data from 773 eyes of 388 subjects with normal ONH over one year was undertaken. Nearly 54% were males, and the mean age was 43.2 years. The CRVT exit was central in 50% (773). The common site for noncentral CRVT was superotemporal (ST) [37%, 141/384] followed by inferotemporal (IT) [35%, 135/384]. With noncentral CRVT, the probability that the inferior, superior, nasal and temporal (ISNT) rule was not followed was 1.42 times ( P < 0.001). The thinnest rim quadrant (TRQ) was mostly ST (69%) irrespective of CRVT location. The TRQ was IT in 40% when CRVT was noncentral and 82% with IT CRVT exit. With noncentral CRVT, round disks favored noncompliance [132 (54.1%), odds ratio (OR) 2.56] with the ISNT rule. The OR of noncompliance with the ISNT rule increases 1.89 times with inferonasal CRVT and 1.22 times with a unit increase in the axial length. TRQ was IT in IT CRVT, and noncompliance with the ISNT rule was observed with large disks, longer axial length, and noncentral CRVT. This implies that despite the ISNT rule being violated these eyes do not have optic nerve pathology and should not be subjected to unnecessary diagnostic tests.

Architecture and Authority: A Spatial Analysis of Power and Control at Three Spanish Colonial Silver Refineries (Puno, Peru)

This paper examines the spatial layout of three Spanish colonial silver refineries from the western Lake Titicaca Basin of southern Peru. These sites, located approximately 15 km from the city of Puno, Peru, were operated by Indigenous laborers throughout the Middle Colonial period (AD 1600–1800). Space syntax analysis is employed to evaluate the degree of control and access across these sites, examining the location of dormitories, storage buildings, administrative patios, work areas, entrances, and exits. Using both intra- and inter-site comparisons, results indicate the presence of restricted and segregated areas at all three refineries. However, inter-site comparisons highlight the integrated nature of the smaller, more rural refineries, revealing how control of labor manifested in diverse ways at the local scale.

Effect of anteromedial portal location on femoral tunnel inclination, length, and location in hamstring autograft-based single-bundle anterior cruciate ligament reconstruction: a prospective study

BackgroundPortal positioning in arthroscopic anterior cruciate ligament reconstruction is critical in facilitating the drilling of the femoral tunnel. However, the traditional approach has limitations. A modified inferior anteromedial portal was developed. Therefore, this study aims to compare the modified and conventional far anteromedial portals for femoral tunnel drilling, assessing factors such as tunnel length, inclination, iatrogenic chondral injury risk, and blowout.Material and methodsPatients scheduled for hamstring autograft-based anatomical single-bundle arthroscopic anterior cruciate ligament reconstruction were divided into two groups: modified and far anteromedial groups. Primary outcomes include differences in femoral tunnel length intraoperatively, tunnel inclination on anteroposterior radiographs, and exit location on lateral radiographs. Secondary outcomes encompass tunnel-related complications and reconstruction failures. To identify potential risk factors for shorter tunnel lengths and posterior exits, regression analysis was conducted.ResultsTunnel parameters of 234 patients were analyzed. In the modified portal group, femoral tunnel length and inclination were significantly higher, with tunnels exhibiting a more anterior exit position (p < 0.05). A higher body mass index exerted a negative influence on tunnel length and inclination. However, obese patients in the modified portal group had longer tunnels, increased inclination, and a lower risk of posterior exit. Only a few tunnel-related complications were observed in the far anteromedial group.ConclusionThe modified portal allowed better control of tunnel length and inclination, ensuring a nonposterior femoral tunnel exit, making it beneficial for obese patients.

Emergency exit layout planning using optimization and agent-based simulation

Evacuation preparedness includes ensuring proper infrastructure, resources and planning for moving people from a dangerous area to safety. This is especially important and challenging during mass gatherings, such as large concerts. In this paper, we present the Emergency Exit Layout Problem (EELP) which is the problem of locating a given number of emergency exits and deciding their width such that the time it takes to evacuate the crowd from an arena is minimized. The EELP takes into account the geography of the arena and its surroundings, as well as the number of pedestrians in the crowd and the distribution of these within the arena. The EELP is formulated as a two-stage stochastic mixed integer linear program to handle the uncertainty related to the location of the possible incidents and the distribution of the pedestrians. Two cases are studied, a large concert planned at the Leangen trotting track in Trondheim and a smaller indoor arena. For each case, the EELP is solved for different scenarios, and the suggested layouts are evaluated using an agent-based simulation model. In particular, the potential of incorporating detailed assessment regarding the location and probability of specific incidents and the distribution of pedestrians are investigated. The computational study shows that making a more detailed risk assessment has little effect on the large concert, but a significant impact on the location of the emergency exits for the smaller indoor case. The results also indicate that it is more important to consider the location and probability of specific incidents rather than the pedestrian distribution.

Design Optimization of Building Exit Locations Based on Building Information Model and Ontology

There are usually multiple functional spaces that meet different usage needs on each building floor. The number of people in different functional spaces varies, resulting in an uneven distribution of people on each floors. When the building is subject to hazards, users inside buildings usually evacuate to safe areas through safety exits. Obviously, when the exit location is close to the crowded area, more people can be evacuated as quickly as possible. However, existing methods for optimizing exit locations of buildings mainly by shortening evacuation paths with limited considerations of the dynamic distributions of evacuees. Since the ontology has semantic description capability and reasonability. Therefore, the ontology is used to organize the design information related to the optimization of exit locations. The rules are further set to reason about the distribution of evacuees and the optimal exit location. Therefore, a design optimization method for exit locations based on BIM and ontology is proposed. Firstly, the ontology is developed to describe the information needed for design optimization. Then, the plan layout information is extracted from BIM as ontology instances. Next, based on the evacuation simulations, the exit location optimization strategies were created for the different distribution of evacuees, and the strategies were translated into SWRL rules. Finally, the ontology instance and SWRL rules are combined to reason about the exit location optimization strategies for specific projects. Therefore, this study provided the exit location optimization strategies to make the evacuation time shorter by considering the distribution of evacuees. The automation of exit location reasoning is further enhanced by using the constructed ontology to organize the design information and by transforming the optimization strategies into SWRL rules. The feasibility of the method was verified using several cases. By comparing the evacuation time of people under the exit location recommended by this method and the exit location designed by the shortest evacuation path, it is concluded that the method proposed in this paper takes into account the distribution of people in the plane and the evacuation time is shorter.

Agent-Based Model of Mass Campus Shooting: Comparing Hiding and Moving of Civilians

The follow-up impact of the campus shooting incident is enormous. Due to a large number of minors (vulnerable groups) and complex building environments, the school is one of the main targets of terrorists. The Sandy Hook Elementary School shooting in 2012 poses a challenge to social and public security. Considering the dichotomous characteristics of the people shot and the impact of the refuge area on the crowd movement in the shooting incident, we use an agent-based model to restore the real target case. Based on the optimal solution, we explore the effects of the number and location of building exits, the scale of the shooter's attack, and the time to find shelter on the shooting results. For building exits, we found that for the environment in the case, the exit location has little impact on the number of casualties, but the increase in the number of exits provides more evacuation routes for the crowd and reduces the number of casualties. Panic will increase the probability of collision and injury. Hiding in a refuge area away from the shooter is effective to avoid shooting injury. At the same time, we propose the critical point of hiding probability. When it is greater than 40%, the faster the escape speed is, the higher the safety is; escape is more likely to replace avoidance in hiding probability less than 40% of environments. These findings are helpful to guide the building evacuation channel construction and emergency evacuation training.

居室避難における火源位置を考慮した出口選択推定モデルに基づく出口配置評価

To evaluate the influence of exit arrangement on room evacuation safety, evacuation risk was estimated based on exit choice according to the relative location of fire source and exits to evacuees.