In order to alleviate the potential congestion problem caused by the sharp increase in evacuation demand on a single shortest path, the multi-path combined evacuation planning scheme considering congestion factors was studied by using Geographic Information System (GIS), Dijkstra algorithm and Yen algorithm. Firstly, the Dijkstra algorithm and the Yen algorithm were used to calculate k shortest evacuation paths from multiple starting points to multiple endpoints. Then, the k shortest paths in each path set are combined with each other to form different evacuation path combination schemes. Finally, the traffic flow of the overlapping sections in the combined route was diverted to reduce congestion, and the optimal combination scheme of evacuation paths was identified. The simulation results show that through calculation, the number of the shortest evacuation paths between each starting and ending point and the total number of evacuation path combination schemes can be obtained. Considering the impact of overlapping sections on evacuation is more in line with the actual situation and can form the optimal combination scheme of evacuation paths.

To enhance the operational stability of urban rail transit stations during rainstorms and waterlogging for safe resident travel, a method for evaluating the importance of resilience influencing factors was proposed based on complex networks. Based on the definition and connotation of resilience, 23 influencing factors of rainstorm waterlogging resilience were extracted from four aspects of stability, robustness, resilience and adaptability. The complex network of influencing factors of resilience was constructed according to the influence relationship between influencing factors. The evaluation index system for the importance of these factors was established, including degree centrality (DC), closeness centrality (CC), betweenness centrality (BC), and clustering coefficient. The order relation analysis method(G1)-Coefficient of Variation (CV) combination weighting method was used to weight the index, and the VlseKriterijumska Optimizacija I Kompromisno Resenje (VIKOR)method was used to identify the key influencing factors. The results show that risk monitoring and early warning system, mobile communication equipment, water retaining capacity of stations, maintenance and repair frequency of flood control equipment, emergency power supply equipment, professional level of flood control staff, drainage capacity of stations, and frequency of flood control training and drilling are the key factors influencing the resilience of urban rail transit stations. The research results can provide new ideas and targeted suggestions for the emergency waterlogging prevention strategies of urban rail transit stations in the rainstorm waterlogging scenario.

In order to optimize the airport security screening channel, the comparison of traditional security channel equipment configuration and new security channel equipment configuration, the cost of the two types of channels was analyzed under the requirements of saving security resources and security. The response value of security screening equipment was simulated by normal distribution, and the false alarm rate and false clear rate were controlled by equipment threshold. The binary decision tree model was used to characterize two types of error probability formulas. For the two types of channel equipment configuration, a nonlinear programming model was established to minimize the security screening cost with the probability of two types of errors as the constraint condition, and the Monte Carlo simulation algorithm was used to solve the problem. The results show that when the new channel is not sampled, the security screening cost of using the new channel can be saved by about 24% compared with the traditional method. When the new channel is sampled at the traditional channel ratio, the cost of using the new channel security screening can be saved by about 18% compared with the traditional one. When the average number of daily single-channel passengers N₁ is between 1 000 and 2 000, the traditional security screening channel equipment can be replaced by a new type of security screening channel equipment, as the per capita security cost is lower than that of the traditional channel. when N₁ is between 500 and 1000, considering the previous fixed cost input problem, the use of traditional channel equipment can be maintained.

In order to comprehensively assess the risk of urban UAVs falling onto ground transportation, a systematic risk assessment method combining theoretical derivation and simulation experiments was proposed. Firstly, the urban air-ground traffic network structure was constructed. Considering the dynamics of UAVs and ground vehicles, as well as the traffic flow characteristics of the air-ground traffic network, theoretical derivation was used to determine the possible ground traffic risk interval. Secondly, Monte Carlo simulation was carried out to obtain the ground traffic risk value based on the statistical results of the test. Then, the theoretical analysis and simulation test analysis were combined to comprehensively evaluate the risk of UAVs falling to ground traffic. Finally, a simulation case study was carried out in Tianjin. The results show that the risk of UAVs falling on ground traffic is affected by several factors such as crash probability, ground traffic density, and the structure of the air road network. The statistical risk value of the simulation test is consistent with the theoretical analysis of the risk interval, which preliminarily verifies the reasonableness of the proposed method.

In order to improve the coordination performance of multi-agents in emergency rescue, the network relationship and internal correlation of four agents were sorted out for urban flood disaster events. Combined with the multi-agent theory, the multi-agent interaction and cooperation framework was built. The multi-agent cooperative simulation model for urban flood disaster emergency rescue was designed. The changes in the number of rescued victims, average rescue time and total rescue time under different disaster scenarios were studied. Results show that the extent of the disaster, the scope of search, the ability of the dominant rescuer and the number of main rescuer are important factors influencing the level of rescue collaboration. Enhancing the scope of search, improving the ability of the dominant rescuer and increasing the investment of the main rescuer contribute to the improvement of the synergistic capacity of disaster emergency response, and the proportion of those affected by disasters who are rescued rises. The robustness analysis shows that the scope of cooperation has a small effect on the number of rescued victims, and the scope of search has a significant effect on the number of rescued victims and the total rescue time. The sensitivity analysis shows that the ability of the dominant rescuer and the number of main rescuer both have a critical value. Once these the critical values are exceeded, the rescue effect will tend to be stabilized.

To investigate the influence mechanisms of smoke environments on pedestrian's evacuation route choice behavior during fires and toxic gas leakages, and to overcome the research challenges posed by ethical constraints that make real-life human experiments difficult to conduct, in this paper, a virtual evacuation experiment platform was constructed. In order to study the influence of smoke level and route length on evacuees' route choice behavior, a single-player route choice experiment was designed and carried out under the influence of smoke, taking into account the pedestrian's speed difference under different smoke scenes in real life. Results indicate that both smoke level and route length have significant influence on evacuees' evacuation route choice behavior. The evacuees prefer to choose the route with lower smoke levels and shorter length. The results of the binary logistic regression model show that compared with the route length (Odds Ratio, OR=15.516), the smoke level (OR=45.475) has a greater influence on the route choice of evacuees. However, a small number of evacuees took a risk, that is, choosing a route with higher smoke levels for evacuation. The post-experiment questionnaire results demonstrated that participants could experience a reasonably authentic evacuation process in smoke-filled environments within the virtual reality scenarios, indicating high levels of validity and reliability for the study.

In order to investigate the impact differences of inter-layer and intra-layer passenger flow transfer proportions after stations failure on the invulnerability of the metro network, a multi-layer directed weighted metro network model was constructed, considering the train running time between stations, station dwell time, passenger transfer walking time, and waiting time. Station initial loads were determined by the actual passenger flow, and the station capacity was calculated using a nonlinear load-capacity model. Stations were sequentially targeted based on their relative importance. The maximum connected subgraph ratio and passenger travel efficiency ratio were selected as the metrics to measure the invulnerability of the metro network. An empirical analysis using the 2021 Xi'an metro network was conducted to study the effects of different inter-layer and intra-layer passenger flow transfer ratios and different capacity adjustment coefficients on the network's invulnerability. The results show that when the inter-layer passenger flow transfer ratio is 0.7, the impact on the invulnerability of the multi-layer metro network is minimal. When the capacity adjustment coefficients are set at b = 0.6 and c = 0.8, appropriately improving station service levels can enhance the network's invulnerability. As the number of attacked stations increases, the invulnerability of the metro network gradually decreases. Under the same attack conditions, the multi-layer directed weighted metro network demonstrates stronger invulnerability compared to the single-layer network, and the network's invulnerability is further reduced when cascading failures are considered.

To clarify the role of the emergency organization in breaking the disaster chain during the execution of emergency tasks and describe the evolution process of the collaborative network, taking the Shulan rainstorm in 2023 as an example, emergency task was regarded as the bridge connecting the disaster event and the emergency organization. The topological structure of the rainstorm disaster chain network and emergency organization network was analyzed. The effect of collaborative network was measured by taking the total amount of vulnerability reduction at the edges of the disaster network controlled by emergency organizations at each stage during the execution of tasks as the standard. The results indicate that disaster events caused by heavy rain exhibit high clustering effects, significant mutual influence, and short disaster paths. In the emergency organization network, most highly centralized organizations are government entities, which have strong capabilities to directly interact with other nodes. By contrast, organizations with low centrality, primarily enterprises and social organizations, tend to be more independent from other nodes. Each emergency organization can coordinate and control critical disaster events and disaster chains with greater vulnerability. In the stage of clearing and resettlement, the number of emergency tasks, disaster-response organizations, and broken chains is the highest, and the total amount of edge vulnerability reduction is also the greatest. By contrast, during the stages of emergency rescue, recovery and reconstruction, early warning and response phases, edge vulnerability reduction decreases sequentially.

The urban lifeline Natech event is a multi-risk and multi-subject coupling system. To qualitatively and quantitatively identify the risk conduction chain of urban lifeline Natech events, first, the risk conduction mechanism was analyzed. Urban lifeline Natech events have both natural disaster chains and domino effects. Then, the complexity and dynamic characteristics of the risk conduction chain were analyzed, and a CN-SD model for the risk conduction chain of the urban lifeline Natech event was constructed. Finally, using the text data of "Top Ten Natural Disasters in China" and their reports, CN indicators such as risk path, risk aggregation, and risk conduction were quantified, and SD indicators such as risk correlation and urban lifeline vulnerability were quantified to numerically simulate the risk conduction rate and degree of urban lifeline Natech event. The results show that the model can qualitatively and quantitatively analyze the risk conduction chain of urban lifeline Natech event, and can visualize the dynamic curves of the domino effect risk conduction rate and degree of technical accidents in transportation, electricity, communication, water supply under natural disaster chain scenarios.

To improve the emergency evacuation ability of miners, simulation models of roadway bifurcation angles (45, 60, 90, 135, 180°) were constructed for horizontal roadway and inclined roadway, respectively. Based on social force theory, the changing characteristics and main forces of roadway bifurcation angles with evacuation time were analyzed, and a relationship model between roadway bifurcation angles and evacuation parameters was established. The orthogonal test was used to investigate the influence of the length, width and position of obstacles on the evacuation efficiency of miners. The results showed that the evacuation process of roadway could be divided into queue passage stage, competitive balance stage and social force effect stage, and the evacuation time decreased with the increase of roadway bifurcation angle, which followed with the cubic polynomial relationship. The optimum bifurcation angle was determined to be 135°. The order of the influence of obstacles on evacuation efficiency is the width of the obstacle> the length of the obstacle > the position of the obstacle, and the width of the obstacle has an exponential relationship with the evacuation time. Taking the roadway bifurcation angle, slope and obstacle width as the static influence coefficients, the calculation shows that under the optimal bifurcation angle, the equivalent length of the roadway is significantly affected by the obstacle width when the obstacle width is greater than 2 m.