Fast flow algorithm prioritizing the most time-consuming source point by using a multi-source evacuation model

2021 ◽  
Author(s):  
Jianfang Yang ◽  
Hao Lin ◽  
Junbiao Guan
Keyword(s):  
Optimal Solution ◽  
Single Source ◽  
Shopping Malls ◽  
Evacuation Time ◽  
Source Point ◽  
The People ◽  
Flow Algorithm ◽  
Evacuation Model ◽  
Fast Flow ◽  
Capacity Constrained

In many public spaces (e.g. colleges and shopping malls), people are frequently distributed discretely, and thus, single-source evacuation, which means there’s only one point of origin, is not always a feasible solution. Hence, this paper discusses a multi-source evacuation model and algorithm, which are intended to evacuate all the people that are trapped within the minimum possible time. This study presents a fast flow algorithm to prioritize the most time-consuming source point under the constraint of route and exit capacity to reduce the evacuation time. This fast flow algorithm overcomes the deficiencies in the existing global optimization fast flow algorithm and capacity constrained route planner (CCRP) algorithm. For the fast flow algorithm, the first step is to determine the optimal solution to single-source evacuation and use the evacuation time of the most time-consuming source and exit gate set as the initial solution. The second step is to determine a multi-source evacuation solution by updating the lower limit of the current evacuation time and the exit gate set continually. The final step is to verify the effectiveness and feasibility of the algorithm through comparison.

scholarly journals Analysis of the Evacuation Capacity of Parallel Double Running Stairs in Different Merging Form Based on Simulation

2018 ◽  
Vol 2018 ◽  
pp. 1-14 ◽  
Author(s):  
Xia-zhong Zheng ◽  
Xue-ling Xie ◽  
Dan Tian ◽  
Jian-lan Zhou ◽  
Ming Zhang
Keyword(s):  
Computer Simulation ◽  
Evaluation Model ◽  
Pedestrian Flow ◽  
Agent Based Model ◽  
Evacuation Time ◽  
Agent Based ◽  
Positive Correlation ◽  
Model Based ◽  
Evacuation Model ◽  
Merging Behavior

In order to analyze the evacuation capacity of parallel double running stairs, a dozen stairs merging forms are set by investigation and statistics, and the improved agent-based evacuation model that considers the merging behavior is used to simulate the process of merging and evacuation in the stairs. The stairs evacuation capacity is related to the evacuation time and the robustness of stairs, and the evacuation time can be calculated by using the improved agent-based model based on computer simulation. The robustness of each merging form can be obtained according to the fluctuation degree of evacuation time under the different pedestrian flow. The evaluation model of stairs evacuation capacity is established by fusing the evacuation time and the robustness of stairs. Combined with the specific example to calculate the evacuation capacity of each stairs form, it is found that every merging form has different evacuation time and different robustness, and the evacuation time has not positive correlation with the robustness for the same form stairs. Meanwhile, the evacuation capacity of stairs is not related to the number of the floor entrances. Finally, the results show that the evacuation capacity of stairs is optimal when the floor entrances are close to out stairs in parallel double running stairs and suitable to the case where pedestrian flow and the change of pedestrian flow are large.

scholarly journals A Multistory Building Evacuation Model Based on Multiple-Factor Analysis

2019 ◽  
Vol 2019 ◽  
pp. 1-14
Author(s):  
Yang Zhou ◽  
Tanghong Wu ◽  
Gaofan Zhang ◽  
Zichuan Fan
Keyword(s):  
Functional Relationship ◽  
Emergency Evacuation ◽  
Multiple Factor Analysis ◽  
Time Step ◽  
Evacuation Time ◽  
Building Evacuation ◽  
Access Path ◽  
Multistory Building ◽  
Evacuation Model ◽  
Evacuation Routes

Emergency evacuation is an important issue in public security. To make a considerate plan, various situations are presented including blocking the accident area and letting the emergency access path available. In order to offer dynamic evacuation routes due to different circumstances, a multistory building evacuation model is proposed. Firstly, to analyse the patency of the building, an evacuation formula is applied after binary processing. The function of evacuation time and some other parameters is given by means of regression analysis. Secondly, the cellular automata (CA) algorithm was applied to illustrate the effect of the bottleneck. The response of evacuation time could be approximately optimized through calculating time step of the CA simulation. Finally, the value of maximum evacuation population density could be determined according to the analysis of CA simulation results, which was related to the switch state of the emergency channel. The emergency evacuation model was simulated by using the Louvre museum as an example. The results of the simulation presented some feasible evacuation routes in all kinds of situations. Furthermore, the functional relationship would also be given among evacuation time with the diversity of tourists, pedestrian density, and width of exits. It can give a different perspective that the multistory building evacuation model shows excellent adaptability to different circumstances.

The Influence of Evacuation Signs on Evacuation for Bad Visibility

2014 ◽  
Vol 472 ◽  
pp. 574-578 ◽  
Author(s):  
Hai Tao Chen ◽  
Peng Yang ◽  
Run Cang Yu
Keyword(s):  
Programming Language ◽  
The Novel ◽  
Evacuation Time ◽  
Time Ratio ◽  
Pedestrian Evacuation ◽  
Calculation Results ◽  
Evacuation Model ◽  
Theoretical Results

In emergencies such as fire, pedestrian evacuation for bad visibility is significantly different to the evacuation for normal visibility. In the novel evacuation model, the strategies of pedestrian evacuation and the moving rules are proposed. Then the formulas of the evacuation time are achieved and the time ratio is 0.63. More, using the programming language, pedestrian evacuation is simulated and reproduced. The studies shows that the proposed evacuation model can well reflect the process of pedestrian evacuation; and the evacuation signs of reasonable design can significantly optimize the process. The calculation results also show that the ratio of evacuation time between considering evacuation signs and no evacuation signs is close to 0.63 that is the theoretical results.

Effects of Smoke on Evacuation

2014 ◽  
Vol 899 ◽  
pp. 539-542
Author(s):  
Martin Lopušniak
Keyword(s):  
National Standards ◽  
Evacuation Time ◽  
Evacuation Model

Smoke is often presents during a fire. It affects efficiency of evacuations in buildings. Slovakian national standards do not consider any fire products in evacuation calculations. The paper presents results of evacuation calculations with considerations of smoke. Calculations are done with the evacuation model buildingEXODUS on a hotel building. Results show that prolongation of evacuation time is up to 162%. Results show that the prolongation of evacuation time is up to 162 %, and also show the prolongation of evacuation time do not necessary depend on size, but on position of smoke.

scholarly journals Robust Suspicious Action Recognition Approach Using Pose Descriptor

2021 ◽  
Vol 2021 ◽  
pp. 1-12
Author(s):  
Waqas Ahmed ◽  
Muhammad Haroon Yousaf ◽  
Amanullah Yasin
Keyword(s):  
Technological Development ◽  
The Body ◽  
Support Vector ◽  
Body Parts ◽  
Shopping Malls ◽  
Public Places ◽  
Video Frames ◽  
The People ◽  
Moving Body ◽  
Benchmark Datasets

In the current era of technological development, human actions can be recorded in public places like airports, shopping malls, and educational institutes, etc., to monitor suspicious activities like terrorism, fighting, theft, and vandalism. Surveillance videos contain adequate visual and motion information for events that occur within a camera’s view. Our study focuses on the concept that actions are a sequence of moving body parts. In this paper, a new descriptor is proposed that formulates human poses and tracks the relative motion of human body parts along with the video frames, and extracts the position and orientation of body parts. We used Part Affinity Fields (PAFs) to acquire the associated body parts of the people present in the frame. The architecture jointly learns the body parts and their associations with other body parts in a sequential process, such that a pose can be formulated step by step. We can obtain the complete pose with a limited number of points as it moves along the video and we can conclude with a defined action. Later, these feature points are classified with a Support Vector Machine (SVM). The proposed work was evaluated on the benchmark datasets, namely, UT-interaction, UCF11, CASIA, and HCA datasets. Our proposed scheme was evaluated on the aforementioned datasets, which contained criminal/suspicious actions, such as kick, punch, push, gun shooting, and sword-fighting, and achieved an accuracy of 96.4% on UT-interaction, 99% on UCF11, 98% on CASIA and 88.72% on HCA.

The Judge and His Hangman: Judicial Selection and the Accountability of Judges in the US

ICL Journal ◽  
2018 ◽  
Vol 12 (3) ◽  
pp. 239-256
Author(s):  
Bertrand Lemennicier ◽  
Nikolai Wenzel
Keyword(s):  
Optimal Solution ◽  
The United States ◽  
Rent Seeking ◽  
Judicial Selection ◽  
The Public ◽  
The People ◽  
Self Interest ◽  
The Us ◽  
Easy Answer ◽  
The Impact

Abstract Who gets to determine rights and justice? Which mechanism of judicial selection and accountability is optimal? There is no easy answer. If judges are independent experts, nominated and evaluated by their peers, they will be immune from the pressures of electoral rent-seeking, but unaccountable to the people. If judges are elected, they will be democratically accountable, but subject to the redistributive pressures of the ballot box. If judges are nominated and controlled by politicians, they will face the temptations of bureaucratic self-interest and will not be democratically accountable, but they will be shielded from the Public Choice problems of elections. This paper uses the death penalty in the United States to measure and compare the impact of different methods of judicial selection. In the end, there is no optimal solution – at least not within a state judicial monopoly.

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