Table of Content

30 June 2023, Volume 33 Issue S1

Previous Issue    Next Issue

Safety science theory and safety system science Safety social science and safety management Safety engineering technology Public safety Emergency technology and management

Safety science theory and safety system science

Research on training mechanism of power emergency management talents

QIAN Jiaqing

2023, 33(S1):  1-6.  doi:10.16265/j.cnki.issn1003-3033.2023.S1.0359

Asbtract ( 157 )   HTML ( 6)   PDF (1574KB) ( 208 )  

References | Related Articles | Metrics

In order to address the serious shortage of strategic management talents and technological leaders urgently needed in the field of emergency management, a comprehensive analysis of the demand for emergency talents was required. In other words, the talents should master both production skills and professional management literacy, and the analysis should focus on aspects such as a relatively small number of existing emergency management talents, a lagging training system, and the scarcity of high-quality and diversified professional academic leaders. On this basis, it was necessary to further explore and improve the emergency expert talent evaluation system, including the training objectives of emergency talents, the qualities that emergency talents should possess, and the establishment of a sound talent evaluation mechanism. Taking the power emergency commander as an example, this study explored ways to expand talent training and supply channels from several aspects such as the responsibilities of the power emergency commander, certified employment, and ability requirements. The results show that the training of emergency management talents should be based on quality and take scientific evaluation as the standard. It shall be supported by professional certification and aims at training high-quality and versatile emergency expert talents, so as to continuously improve the yield and quality of emergency expert talents and enhance the training level of high-level expert talents.

Exploration and application of security management mode based on ″grid & matrix″

TU Xian, YANG Jianping

2023, 33(S1):  7-11.  doi:10.16265/j.cnki.issn1003-3033.2023.S1.0125

Asbtract ( 200 )   HTML ( 3)   PDF (2157KB) ( 201 )  

Figures and Tables | References | Related Articles | Metrics

In order to solve the problem of security management separation and conceptual inconsistency between the design unit and the construction unit under the EPC consortium model, the EPC project for the construction of a new factory of Three Gorges Cigarette Factory, Hubei Tobacco Industry Co., Ltd., was taken as an example, and the experience of community epidemic prevention and control grid management was fully learned. A relatively mature matrix management model in the field of engineering project management was introduced, so as to expand the professional advantages of horizontal project management and vertical functional management system architecture and construct a project security management organizational architecture based on ″grid & matrix″. By combining unmanned aerial vehicle cruising, monitoring networking, and BIM simulation exercises, the prevention capacity and monitoring and early warning capacity were improved. The results indicate that the application of project security management organizational architecture based on ″grid & matrix″ and multiple information technology means can help solve the problems of unclear responsibilities and weak supervision of various participating units in conventional project construction security management, improve enterprises' safety benefits, and reduce the probability of accidents.

Present situation and development countermeasure of emergency industry in Fujian province

SUN Xiaowan, LONG Shengyi, YANG Fuqiang, HONG Yidu

2023, 33(S1):  12-19.  doi:10.16265/j.cnki.issn1003-3033.2023.S1.0160

Asbtract ( 161 )   HTML ( 5)   PDF (5835KB) ( 405 )  

Figures and Tables | References | Related Articles | Metrics

In order to improve its social governance ability and safety guarantee capacity and support high-quality economic development, an analysis was conducted on the development status of the emergency industry in Fujian Province. Based on the regional characteristics of Fujian Province, four industrial clusters focusing on safety protection, monitoring and early warning, emergency rescue and disposal, and safety and emergency services were proposed by using system analysis and other methods. The current industrial status was examined from these four aspects, and new countermeasures for the development and optimization of the emergency industry were suggested. The results show that the development of the emergency industry in Fujian Province is relatively slow, and there are few demonstration bases for the emergency industry. The output value of the emergency industry is not high. The emergency industry in Fujian Province has some problems, such as a low technical level of emergency products, weak and immature independent innovation ability, low scientific and technological content, and a lack of emergency personnel. Countermeasures are put forward from the aspects of emergency industry development guidance, policy implementation, scientific and technological innovation, training of professionals, and international exchanges and cooperation.

Safety social science and safety management

Practice research on enterprise safety culture construction in Daqing oilfield

ZHOU Peng, ZHANG Tingting, WANG Yu

2023, 33(S1):  20-24.  doi:10.16265/j.cnki.issn1003-3033.2023.S1.0328

Asbtract ( 188 )   HTML ( 5)   PDF (1550KB) ( 163 )  

References | Related Articles | Metrics

In order to reduce the probability of safety accidents, improve the level of enterprise safety construction and the safety quality of employees, and build a long-term mechanism for enterprise safety production, Daqing Oilfield was taken as an example to sort out the course of safety culture construction practice. By summarizing the typical features and practices of Daqing Oilfield in the traditional safety management stage, HSE system management stage, and safety culture consolidation and enhancement stage, the focuses of culture construction under different management systems were analyzed, and the mechanism of enterprise safety management was explored. The process of safety culture evolution was sorted out. The results have indicated that traditional safety management can effectively protect personnel, equipment, and other property safety and reduce the occurrence of accidents, but employee participation is insufficient. The HSE system audits, inspections, and daily supervision have not eliminated the hidden accidents, and the on-site risks are relatively still high. The major problem lies in the negligence of safety culture construction. Enterprises should pay attention to safety culture construction to maintain the continuity of safety culture construction and improve the level of enterprise safety management.

Analysis of effect of colored pavement and sidewall design on driving behavior in tunnels

WAN Li, ZHANG Chang'an, LI Jing, ZHANG Yu, SUN Changhai, YAN Ying

2023, 33(S1):  25-34.  doi:10.16265/j.cnki.issn1003-3033.2023.S1.0051

Asbtract ( 113 )   HTML ( 1)   PDF (9779KB) ( 55 )  

Figures and Tables | References | Related Articles | Metrics

In order to explore the driving performance and the physical and psychological change characteristics of drivers under different tunnel environment designs, three-dimensional Max software was used to construct a simulation experiment scene. 15 drivers were selected to participate in driving simulation experiments of different tunnel environment design scenarios, and the physical and psychological data of the drivers and the vehicle operation status data were collected. The representative vehicle operation indicators and driver state indicators were selected, and the driving behavior trend surface model was constructed. The relative sensitivity between the indicators was analyzed. The results show that colored pavements can prompt the driver to decelerate appropriately. The comprehensive effects of gradient yellow pavements and colored pavements with longitudinal deceleration marking are better, which are more conducive to safe driving; the decorated sidewalls in the tunnel can alleviate the phenomenon of monotonous visual information of drivers in the tunnel. In view of the driving safety and traffic efficiency in the tunnel, it is recommended to use blue-white decorated sidewalls.

Research on subway operation safety risk management based on ontology technology

DENG Yongliang, ZHANG Ying, LUO Li, LI Yang, LIN Lingna

2023, 33(S1):  35-41.  doi:10.16265/j.cnki.issn1003-3033.2023.S1.2536

Asbtract ( 124 )   HTML ( 2)   PDF (4453KB) ( 190 )  

Figures and Tables | References | Related Articles | Metrics

In order to promote the sharing and practice of subway operation safety risk knowledge and improve the level of subway operation safety management, this study proposed the construction and application methods of subway operation safety risk ontology. Firstly, this paper introduced the ontology technology and analyzed its advantages in the field of safety risk management. Then, the safety accidents during subway operations in China and abroad were collected, and the domain ontology model of subway operation safety risks was constructed from five aspects: causes, accident types, accident consequences, accident grades, and countermeasures. Finally, association rule analysis and rule construction were carried out based on ontology technology, and the fire accident was taken as an example to carry out the rule-based reasoning research on the fire risk during the subway operation. The results show that the systematic analysis and structured storage of subway operation safety risk knowledge can be achieved based on ontology technology, and rule-based reasoning can be used to determine the level of safety accidents and match response measures, so as to assist emergency decision-making.

Classification and gradation of hidden dangers of offshore oil in China

CAO Yang

2023, 33(S1):  42-47.  doi:10.16265/j.cnki.issn1003-3033.2023.S1.1623

Asbtract ( 296 )   HTML ( 3)   PDF (1568KB) ( 255 )  

Figures and Tables | References | Related Articles | Metrics

In order to further improve the classification and grading of hidden dangers of offshore oil in China, relevant laws and regulations, as well as departmental rules and standards were collected. Based on the characteristics of the offshore oil industry, the hidden danger was defined, and its classification principles were elaborated. The classification standards of hidden dangers issued by administrative departments, different industries, and oil companies were compared, and the classification method of hidden danger of offshore oil in China was given. The grading standards of hidden dangers issued by administrative departments, different industries, and oil companies were also compared. On the basis of the classification of hidden dangers in the department of emergency management, the grading method for hidden dangers of offshore oil in China was proposed. The results show that the proposed classification method of hidden dangers of offshore oil can be further extended to seven major categories such as operators, designs, equipment and facilities, materials, environmental conditions, management, and compliance, as well as 43 subcategories. The hidden dangers of offshore oil are classified into six grades: ″one vote veto″, particularly significant, major, comparatively major, general, and minor.

Application of five-dimensional analysis method in safety hazard investigation and governance

MENG Fanhua, LU Hong, XIAO Yujun, LIU Wenze

2023, 33(S1):  48-51.  doi:10.16265/j.cnki.issn1003-3033.2023.S1.0127

Asbtract ( 188 )   HTML ( 3)   PDF (1495KB) ( 166 )  

References | Related Articles | Metrics

In order to effectively manage safety hazards and reduce the likelihood of accidents, a five-dimensional analysis method was used to establish a safety hazard investigation and governance model. Through the analysis from five dimensions: scale, awareness, grid, behavior, and exposure, the characteristics and influencing factors of safety hazards were comprehensively sorted out, and scientific and effective safety control measures and management strategies were formulated. Research has shown that the implementation of the five-dimensional analysis method to address safety hazards involves systematic governance, comprehensive governance, source governance, and legal governance from all aspects of safety hazard investigation and governance. The five dimensions are interconnected to form a comprehensive and effective safety hazard governance model, ensuring workplace safety and personnel health and improving safety management levels.

Risk assessment of coal and gas outburst based on combination weighting and grey clustering

SHI Hongkai, QI Yun, ZHANG Guoen, JIANG Xiaoyu, HE Xiang, SUN Yuanhang

2023, 33(S1):  52-57.  doi:10.16265/j.cnki.issn1003-3033.2023.S1.0593

Asbtract ( 133 )   HTML ( 3)   PDF (1738KB) ( 163 )  

Figures and Tables | References | Related Articles | Metrics

In order to effectively prevent coal and gas outburst accidents in coal mines, a combined weighting grey clustering risk assessment model for coal and gas outburst is proposed. Firstly, based on trajectory crossover theory, prediction indicators are selected from three aspects: coal seam physical properties, gas indicators, and coal seam occurrence conditions, and a risk assessment index system is constructed. Then, the Improved Analytic Hierarchy Process (IAHP) and Entropy Weight Method (EWM) are used to determine the weights of each indicator, and a grey fuzzy evaluation standardized level judgment matrix for each indicator is constructed based on the grey clustering principle. The coal and gas outburst level is predicted based on the principle of maximum membership degree. Finally, taking the 12407 fully mechanized top coal caving face of Ulan Mulun Coal Mine as an application example, the effectiveness of the combination weighting grey clustering evaluation model was verified. The results show that the danger level of coal and gas outburst in this working face is Ⅴ. The model calculation results are basically consistent with the actual situation on site. The physical properties of coal seams are the main inducing factors. The evaluation results are consistent with the actual situation. It is proved that the model is scientific and effective.

Resilience assessment of chemical industry parks based on comprehensive weighting-RSR method

YUE Wenjing, YUAN Bihe, SU Shuyan, YANG Man, YANG Jiaqi, WEN Xueli

2023, 33(S1):  58-63.  doi:10.16265/j.cnki.issn1003-3033.2023.S1.2454

Asbtract ( 148 )   HTML ( 2)   PDF (1613KB) ( 178 )  

Figures and Tables | References | Related Articles | Metrics

In order to accurately improve the resilience, recovery, and adaptability of a chemical industry park in the face of uncertainties, a chemical industry park was taken as an example to build a resilience assessment model. Firstly, based on the public safety triangle theory, an assessment system based on the risk of disaster disturbance factors, the vulnerability of disaster-bearing bodies, and the ability of disaster prevention and mitigation was established. The index weight was given by the subjective and objective combination of fuzzy interval scoring and CRITIC method, and the RSR method was introduced to rank the weighted index elements, so as to explore the resilience and weak points of the park in the face of disaster impact. Finally, the overall resilience was graded according to the RSR method. The results show that the overall resilience level of the park is in the third grade. The resilience level is high, and the safety state is good. The proposed method is effective, accurate, and scientific, and it is helpful to improve the resilience level of chemical industry parks and strengthen the construction of disaster prevention and reduction of chemical industry parks.

Safety engineering technology

Study on relationship between dual prevention mechanisms of safety production

WEI Shanfeng

2023, 33(S1):  64-68.  doi:10.16265/j.cnki.issn1003-3033.2023.S1.0130

Asbtract ( 314 )   HTML ( 13)   PDF (2428KB) ( 221 )  

Figures and Tables | References | Related Articles | Metrics

In order to make enterprises correctly construct and scientifically use the dual prevention mechanism, it is necessary to understand the concepts and meanings of hazards, risks, and hidden dangers in the dual prevention mechanism and clarify the contents and methods of hazard identification and risk assessment. The two-point theory and the key theory in the law of the unity of opposites of dialectics should be used to analyze the relationship and function between grading management and control of safety risks and investigation and governance of hidden dangers. This study analyzed the whole process and its dialectical relationship from hazard identification to risk assessment and from investigation and governance of hidden dangers to management and control of risks. It clarified the relationship between dual prevention mechanisms and drew the relationship diagram of the dual prevention mechanism. The results show that the dual prevention mechanism is two kinds of working methods that are related but separated from each other. It is a working mechanism that focuses on grading management and control of safety risks, supplemented by investigation and governance of hidden dangers. It is a dual prevention system that combines primary and secondary prevention of accidents.

Risk propensity discrimination of construction accidents under coupling of human-management-environment factors

XIONG Jian, PENG Yiming, CHEN Yao, SONG Zhike, CAI Jing

2023, 33(S1):  69-75.  doi:10.16265/j.cnki.issn1003-3033.2023.S1.1485

Asbtract ( 149 )   HTML ( 4)   PDF (2523KB) ( 176 )  

Figures and Tables | References | Related Articles | Metrics

In order to prevent and reduce construction accidents, a machine learning algorithm was used to identify the risk propensity of accidents from the perspectives of humans, management, and external environments. Firstly, according to the three factors of humans, management, and environments, the scales for measuring the overconfidence of construction personnel, organizational management atmosphere, and construction environment risk levels were designed and tested respectively. Secondly, according to the score of the scale, the K-means algorithm was used to classify different types of accident risk propensity, and comprehensive risk factors were proposed to judge the clustering results. Finally, principal component analysis, Borderline-Smote, and LightGBM algorithms were used to establish the risk propensity discrimination model of construction accidents, and the stability of the model was evaluated by the k-fold cross-validation method. The results show that the prediction accuracy rate of the model is 90.83%. Therefore, the model can effectively identify the risk level of construction accidents, and the accident risks can be divided into three types: low-risk propensity, medium-risk propensity, and high-risk propensity.

Research on anti-overstep of downhole power supply system based on signal injection and decentralized detection

WANG Yongjun, LIU Xin

2023, 33(S1):  76-80.  doi:10.16265/j.cnki.issn1003-3033.2023.S1.0531

Asbtract ( 121 )   HTML ( 1)   PDF (2139KB) ( 143 )  

Figures and Tables | References | Related Articles | Metrics

In order to effectively solve the problem of overstep tripping caused by short circuit of the power supply system in coal mines, according to the principle of decentralized detection of single-phase grounding fault of injected signal, the single-phase grounding fault line selection theory was proposed based on the combination of signal injection and decentralized detection, and zero sequence current was added to the fault circuit to provide the ideal zero sequence current to the fault system. In addition, analog components were used to build a test system to test the injected signal detection part, and a test model was built to realize the single-phase grounding fault of the power grid system. Digital optical fiber communication protector of the underground distribution network was used to ensure rapid and accurate actions and fault isolation after the failure of the underground power supply system. The results show that by injecting a signal with a main frequency of 80 Hz and an amplitude of 40 mA, the signal filtering algorithm can filter out the interference of power frequency and harmonic signal. When the frequency of the injected signal is offset in a small range, the device can accurately detect and extract the injected signal to judge the fault.

Video detection algorithm based on semantic segmentation for conveyor belt deviation

ZHAO Guanghui, ZHAO Peng, HU Jinliang

2023, 33(S1):  81-84.  doi:10.16265/j.cnki.issn1003-3033.2023.S1.5006

Asbtract ( 193 )   HTML ( 7)   PDF (1978KB) ( 109 )  

Figures and Tables | References | Related Articles | Metrics

In order to avoid the problem of serious production accidents caused by the conveyor belt running off the mine road during the sorting operation in the coal processing plant, a video detection algorithm fusing Gaussian edge projection based on semantic segmentation was proposed, which monitored the conveyor belt deviation in real time. First, the algorithm was preprocessed by Gaussian filtering to reduce the influence of video image noise on the neural network. Then, a radial basis neural network structure with fused Gaussian projection was constructed to enhance the edge information of the image, and the Gaussian projection was fused into the network to realize semantic segmentation, which ensured the recognition and detection effect while reducing the computational consumption of the network as much as possible. The results show that the algorithm can accurately recognize and detect the conveyor belt and then realize the conveyor belt deviation warning through the experimental scene verification and analysis of the working video of the mine road in the coal processing plant. Meanwhile, the algorithm consumes fewer computational resources and has higher computational efficiency than the typical deep learning model of semantic segmentation while realizing the effective function.

Intelligent inspection research based on belt conveyor

HU Jinliang

2023, 33(S1):  85-90.  doi:10.16265/j.cnki.issn1003-3033.2023.S1.5001

Asbtract ( 146 )   HTML ( 0)   PDF (3901KB) ( 404 )  

Figures and Tables | References | Related Articles | Metrics

M14 and M33, two kinds of long-distance coal belt conveyors in Harwusu Coal Preparation Plant of Zhunneng Group, fail due to equipment quality and human factors, which affect the smooth operation of the coal mine. In order to solve this problem, the present situation of intelligent inspection of belt conveyors was analyzed, and the demand for intelligent inspection of belt conveyors was clarified. Then, the inspection robot was selected, and the system management analysis and the characteristic function design were carried out. The main inspection contents of the inspection robot were defined. The real-time monitoring interface shows that the inspection robot can provide high-resolution and infrared video information in real time, including micrometeorological information, inspection tasks, and inspection results. The inspection plan interface shows that the inspection robot can edit inspection tasks, make inspection plans, and deliver routine inspection tasks. The inspection report interface shows that the inspection robot can provide the device statistical map, device defects, statistical data, and task calendar.

Design and application of drilling and well control simulation experimental platform

WU Song, WANG Yanfu, CHEN Wentao, MA Weikai

2023, 33(S1):  91-96.  doi:10.16265/j.cnki.issn1003-3033.2023.S1.0838

Asbtract ( 117 )   HTML ( 0)   PDF (5758KB) ( 214 )  

Figures and Tables | References | Related Articles | Metrics

In order to enable students to master the methods and steps of well shut-in after overflow occurs under different working conditions, a drilling and well control simulation experiment platform was designed and applied, so as to carry out vivid and intuitive drilling and well control simulation experiments for undergraduates. By integrating simulation with practical operations, the students learned the correct operation steps in the process of well control operations. The results show that the simulation experimental platform can effectively combine theoretical learning and practical training, make students understand the process and safe operation requirements of well control operations, and improve students' ability to deal with overflow, blowout, and other accidents. It not only improves the teaching level but also lays a solid foundation for students to adapt to drilling site work as soon as possible after graduation. It is expected to become an essential link in the process of well control safety technology training and emergency operation training.

Research progress and prospect of multi-phase synergistic explosion suppression of coal mine gas

ZHANG Licong, LI Siman, ZHOU Zhenxing

2023, 33(S1):  97-104.  doi:10.16265/j.cnki.issn1003-3033.2023.S1.0016

Asbtract ( 145 )   HTML ( 1)   PDF (1709KB) ( 191 )  

Figures and Tables | References | Related Articles | Metrics

In order to deeply study the explosion suppression process, parameter change, and practical application of various kinds of coal mine gas explosion suppressants, the types, action mechanism, and research methods of gas explosion suppressants in China and abroad were analyzed, and it is concluded that there are five kinds of explosion suppressants: inert gas, water mist, powder, porous medium, and halogenated hydrocarbon. The mechanism includes physical effects such as dilution of reactant concentration, decomposition and heat absorption of explosion suppressant, absorption of free radicals, and wave absorption and vibration reduction, as well as chemical effects such as consumption of key free radicals including hydrogen radical and hydroxyl radical. The synergistic suppression effect of N₂-water mist on flame propagation is better than that of CO₂-water mist, but the explosion suppression effect of CO₂ is better than that of N₂ under the same conditions in terms of overpressure peak and pressure time history. On the basis of experiments, numerical simulation can show the development process of explosion suppression in real coal mine environments and make the turbulent disturbance and the quantity change of each free radical in the process of explosion suppression more detailed and specific. Finally, in the development of gas explosion suppressants, it is necessary to start with the elementary reaction of active free radicals such as hydrogen radical and hydroxyl radical, reduce its content, and delay the gas explosion process, so as to achieve the purpose of explosion suppression.

Study on damage influence of explosion caused by molten aluminum leakage in deep well casting with water

LIU Jie, WANG Ren

2023, 33(S1):  105-111.  doi:10.16265/j.cnki.issn1003-3033.2023.S1.0082

Asbtract ( 190 )   HTML ( 13)   PDF (1632KB) ( 175 )  

Figures and Tables | References | Related Articles | Metrics

In order to deeply understand the mechanism of the explosion of molten aluminum liquid in contact with water and quantify the damage influence caused by the explosion, data models and calculation analysis were established in terms of the overpressure damage caused by physical steam explosion and chemical oxidation reaction explosion and the flight distance of explosion fragments. The damage to personnel and buildings caused by the overpressure damage due to the explosion of molten aluminum liquid in contact with water under different calculated amounts was described in detail, and the influence range related to the flight distance of explosion fragments under different ejection angles was discussed, so as to more intuitively understand the damage influence caused by the explosion. The results show that the chemical explosion is the most destructive, followed by the physical explosion and the fragment ejection caused by the explosion during the explosion of molten aluminum in contact with water. At the same initial velocity of the ejection, the farthest horizontal distance of the fragment is achieved at the ejection angle of 30°.

High-resilience safety assessment method of underground coal mining using AdaBoost

XU Xiaobin, SHI Fan, FENG Jing, XU Xiaojian, CHANG Leilei

2023, 33(S1):  112-118.  doi:10.16265/j.cnki.issn1003-3033.2023.S1.1304

Asbtract ( 113 )   HTML ( 0)   PDF (3652KB) ( 105 )  

Figures and Tables | References | Related Articles | Metrics

In order to ensure the safety of coal mining engineering, a high-resilience safety assessment method based on AdaBoost was proposed. Firstly, the tunnel design parameters, geological condition parameters, and construction parameters were taken as the input of the model, and the mine settlement value was taken as the output. The input parameter data collected at the construction site were divided into a training data set and a test data set. Secondly, multiple data sets were extracted from the data set to establish multiple sub-models respectively. Then, the errors and weights of the sub-models were calculated respectively, and the neural network was used as the benchmark model. All the training data sets were divided into normal data and abnormal data, and the weights were updated. Finally, according to the weighted data set, the AdaBoost prediction model was built, and case analysis was carried out. The effectiveness of the method was verified. The results show that the high-resilience safety assessment method using AdaBoost established based on normal data and abnormal data has higher accuracy than the results obtained by directly using the AdaBoost algorithm, which proves that the proposed method is scientific and effective.

Prediction method of saturation line of tailings dam based on CNN-aGRU fusion model

RUAN Shunling, HAN Simiao, ZHANG Ningning, GU Qinghua, LU Caiwu

2023, 33(S1):  119-127.  doi:10.16265/j.cnki.issn1003-3033.2023.S1.2481

Asbtract ( 171 )   HTML ( 4)   PDF (6772KB) ( 261 )  

Figures and Tables | References | Related Articles | Metrics

In order to prevent the safety accident caused by tailings dam breaks, correlation analysis was conducted on the depth of online monitoring data. A safety situation prediction method of the saturation line of the tailings dam was proposed, which integrated CNN and GRU, so as to grasp the stability and safety development trend of the dam. By comprehensively considering the complex nonlinear and time-series correlation characteristics of monitoring data of the tailings dam, a one-dimensional CNN network was introduced to obtain the local correlation characteristics and spatial characteristics among the multi-source data. Then the GRU model was used to extract the time-series characteristics of the saturation line data. AdamW was used to optimize the adaptability of the model gradient, so as to improve the generalization ability and prediction accuracy of the prediction model. The method was tested and verified in the tailings dam of a metal open-pit molybdenum mine in Luoyang, Henan Province. The results show that compared with the traditional back propagation (BP) neural network, long short-term memory (LSTM) network, GRU, and other prediction models, the proposed prediction model reaches 0.013 915 62, 0.005 432, 0.000 045, 0.006 702, and 0.998 334 for the key indices of mean absolute percentage error (MAPE), mean absolute error (MAE), mean squared error (MSE), root mean squared error (RMSE), and R², respectively. The method thus can rapidly and accurately predict saturation line changes.

Study on risk classification and critical value of key indexes of potassium nitrate by granulation

MA Yanping, SUN Huaibo, FAN Bin

2023, 33(S1):  128-133.  doi:10.16265/j.cnki.issn1003-3033.2023.S1.0177

Asbtract ( 160 )   HTML ( 1)   PDF (1713KB) ( 91 )  

Figures and Tables | References | Related Articles | Metrics

In order to clarify the influence of granulation on the classification results of the oxidation test of potassium nitrate and analyze the critical conditions for the exemption of granulated potassium nitrate from oxidant transport classification, this study selected granulated potassium nitrate products from representative enterprises in the industry. The study also carried out vibration and impact tests on samples with different particle sizes to simulate extreme conditions in the transport process. The crushing resistance and oxidation index of the samples before and after vibration and impact were evaluated. The results show that particle size is an important factor affecting the oxidation strength of granulated potassium nitrate. The particle size of granulated potassium nitrate with a high tower is above 2.8 mm; the particle size of granulated potassium nitrate with a high tower and inert material coating is above 2.5 mm, and that of compressed granulated potassium nitrate is above 3.0 mm. Therefore, the particle size can meet the classification standard of non-5.1 items in the national standard Classification and code of Dangerous Goods (GB 6944-2012), and there is the possibility for the exemption of oxidant transport classification.

Video detection algorithm based on small sample for foreign objects in conveyor belt

JIA Shangfeng, WANG Zhiqiang, HAO Xinyu

2023, 33(S1):  134-137.  doi:10.16265/j.cnki.issn1003-3033.2023.S1.5005

Asbtract ( 181 )   HTML ( 17)   PDF (1800KB) ( 95 )  

Figures and Tables | References | Related Articles | Metrics

Since the data sets of foreign objects in the conveyor belt collected by the video detection algorithm based on deep learning for foreign objects in the conveyor belt were fewer, this paper proposed a detection algorithm based on YOLOX for foreign objects in the conveyor belt. First, MobileNet V3 was used to replace the backbone feature extraction network CSPDarknet in YOLOX to reduce the calculation time of the backbone features, and then the convolutional network in the enhanced feature extraction network in YOLOX was replaced with a deep separable convolutional neural network to reduce the calculation time of the enhanced feature extraction network. Finally, a convolutional block attention module (CBAM) was added before the deep separable convolutional neural network in the enhanced feature extraction network to improve detection accuracy. Experiments have verified that the algorithm used in this paper can complete the training and achieve a recognition accuracy of 96.5% when using a small number of samples. At the same time, the average time of this algorithm is only 0.019 s, and the recognition frame rate can reach 40 FPS.

Research on 3D real scene reconstruction for road traffic accidents

ZHENG Jinzi, YANG Qi, LIU Jun, LI Liang, CHAI Yanan, XU Pengfei

2023, 33(S1):  138-144.  doi:10.16265/j.cnki.issn1003-3033.2023.S1.0132

Asbtract ( 228 )   HTML ( 3)   PDF (3440KB) ( 306 )  

Figures and Tables | References | Related Articles | Metrics

In response to the shortcomings of traditional methods for scene investigation of road traffic accidents, such as long time consumption, difficulty in re-exploration, and low accuracy, the technology of three-dimensional (3D) real scene reconstruction for road traffic accidents was explored. Combined with the application experience of 3D real scene reconstruction in relevant fields, the following research work including field image acquisition and internal model construction was carried out. In response to the diverse geological forms, uncertain scale, and short duration of traces at road traffic accident scenes, a series of UAV tilt photography was proposed for different types of accident scenes. The algorithm of 3D real scene reconstruction for traffic accident scene modeling was designed, and the precision inspection method of accident scene survey based on 3D real scene model was developed. A single vehicle rollover accident on Shanxi highway was selected as a case study to construct a 3D real scene model of this accident and to verify its accuracy. Research has shown that the survey method for road traffic accidents based on a 3D real scene model can reduce the survey time by more than half and facilitate re-survey after traffic recovery. Besides, the constructed 3D model of the accident scene has an accuracy of centimeter level, and the measurement error meets the industry standard of Investigation of Road Traffic Accident Traces and Evidence issued by the Ministry of Public Security.

Online monitoring of hydraulic brake of mine hoist based on LabVIEW

LIU Xin, WANG Yajun, YAO Meichang, SU Lei, WANG Peng

2023, 33(S1):  145-149.  doi:10.16265/j.cnki.issn1003-3033.2023.S1.0513

Asbtract ( 111 )   HTML ( 2)   PDF (1646KB) ( 131 )  

Figures and Tables | References | Related Articles | Metrics

In order to ensure the reliability and safety of the hydraulic brake system of the mine hoist during operation, an online monitoring device for the hydraulic brake system of the mine hoist based on LabVIEW was designed. LabVIEW and programmable logic controller (PLC) were combined, and the powerful data processing capability of LabVIEW was fully utilized to detect the state parameters of the hydraulic brake system and then analyze and evaluate the device's working condition. A new type of disc spring seat sensor was used to establish the mathematical model of brake positive pressure and strain. By analyzing the fault parameters of the hydraulic station and brake, the fault diagnosis expert system was adopted to diagnose the fault of the hydraulic brake and realize the safety early warning of the hydraulic brake system of the mine hoist. The results show that the online monitoring device of the hydraulic brake system of the mine hoist monitors eight functional modules in real time and uses a hydraulic system fault tree to make real-time fault diagnosis of the system, which is of great significance to ensure the safety and reliability of the mine hoist, extend the service life, improve the mine production efficiency, and reduce maintenance cost.

Research on security risk of obstacle shielding based on CRM model

ZHAO Leitong, LIU Xin, YAN Huanhuan

2023, 33(S1):  150-155.  doi:10.16265/j.cnki.issn1003-3033.2023.S1.0568

Asbtract ( 137 )   HTML ( 1)   PDF (2686KB) ( 213 )  

Figures and Tables | References | Related Articles | Metrics

In order to study the application rules of shielding and prevent super-high obstacles from affecting the safe operation of airports. First,investigate and analyze the application of shading in many countries such as the United States,the United Kingdom,and India; secondly, aiming at different shading areas in the obstacle restriction plane around the airport, use the collision risk model (CRM) to simulate the collision risk value of the obstacle shading point,and propose different Area shielding rules. Finally,combined with the actual situation, the methods and requirements for different areas within the obstacle limitation surfaces are proposed. The results showed that the shielding areas in the take-off climbing surface and the approach plane are designed according to a certain diffusion rate; the principle of shielding is not recommended in the transitional plane; the inner horizontal plane and the conical plane are divided into areas.

Fuzzy comprehensive evaluation of urban bridge reliability based on combination weighting method

ZHOU Haiyi, BAO Quangui, YE Mao, ZHU Shengwen, LIN Yingdian

2023, 33(S1):  156-161.  doi:10.16265/j.cnki.issn1003-3033.2023.S1.2494

Asbtract ( 136 )   HTML ( 3)   PDF (1683KB) ( 175 )  

Figures and Tables | References | Related Articles | Metrics

In order to evaluate the reliability of urban bridges and prevent safety accidents of bridges, the multi-standard and multi-factor requirements of urban bridge evaluation and the complexity and fuzziness of the evaluation system were considered. A comprehensive evaluation index system for bridge structure reliability was established according to the structural characteristics and code requirements of urban bridges. An improved AHP was adopted to construct a judgment matrix through the 1-9 scale method and the natural index scale method, so as to determine the subjective weights of indexes at all levels of the evaluation system. The objective weights of indexes at all levels were determined through the EWM, and the indexes were empowered by combining the above two methods. The fuzzy theory was introduced, and the Cauchy distribution membership function was selected and corrected based on the characteristics of bridge structure engineering. Then the membership matrix values of the indexes at all levels were calculated. The index system and calculation method were validated in real bridge structure engineering. The results show that combining industry codes and expert experience to establish an evaluation index system, using an improved AHP based on the existing research, and introducing fuzzy theory can enhance the objectivity and accuracy of bridge reliability evaluation.

Optimization of integrated operation process of unmanned aerial vehicles in hill fire inspection and extinguishing of transmission lines

WANG Qifei, HOU Chenghao, LI Cong, CHENG Haitao, ZHOU Biao

2023, 33(S1):  162-168.  doi:10.16265/j.cnki.issn1003-3033.2023.S1.4001

Asbtract ( 112 )   HTML ( 1)   PDF (4003KB) ( 145 )  

Figures and Tables | References | Related Articles | Metrics

Unmanned aerial vehicles (UAVs) face long time consumption and low work efficiency in inspecting fire hazards around transmission lines in mountainous areas and performing early fire extinguishing operations. In order to solve these problems, the existing UAV inspection and fire extinguishing processes were merged and reorganized. Firstly, based on the existing research on UAV inspection and fire extinguishing processes, process program analysis and Petri net model method were adopted, and the processes of UAV inspection and fire extinguishing were analyzed to obtain the corresponding operation process. The correlation matrix and invariant analysis method were used to test the model to ensure its applicability. Then, the two independent steps were unified, and the repeated steps were merged based on the principle of eliminate, combine, rearrange, and simplify (ECRS). The final optimized process scheme was thus obtained. Finally, through the simulation of the same case, the difference between the model before and after the integration optimization was analyzed and calculated. The results show that the optimized scheme based on Petri net can greatly improve the rapid response ability of UAVs for fire extinguishing after receiving the fire source coordinate position information and reduce the repeated operation process and unnecessary time consumption. Compared with that of the traditional operation scheme, the operation time of the optimized process scheme is reduced by 39.1%, and the handling distance is reduced by 50%.

Research on technical system of UAV and manual cooperative inspection

CHENG Haitao, LIU Junnan, WU Zhuoqi, LI Cong, ZHANG Weihao

2023, 33(S1):  169-173.  doi:10.16265/j.cnki.issn1003-3033.2023.S1.4007

Asbtract ( 115 )   HTML ( 1)   PDF (1513KB) ( 128 )  

Figures and Tables | References | Related Articles | Metrics

In order to further study the technical system of the unmanned aerial vehicle (UAV) and manual cooperative inspection and improve the application value of the system, the influencing factors and indicator systems of manual inspection and UAV inspection were systematically analyzed. Feature analysis and effect evaluation of UAV and manual cooperative inspection technology were conducted. The results show that manual inspection is influenced by five major factors including terrain conditions, weather conditions, road conditions, fire conditions, and inspection objects, while UAV inspection is influenced by terrain conditions, weather conditions, road conditions, and fire conditions. An evaluation system consisting of 18 four-level indicators for manual inspection, as well as that consisting of 25 four-level indicators for UAV inspection were constructed. UAV and manual cooperative inspections have received the highest scores in terms of quality, efficiency, and safety, and it is significantly superior to a single inspection method, which can further improve the efficiency and precision of fire extinguishing work.

Characteristic analysis and prevention and control countermeasures of emergencies along high-speed railways

WANG Meng, SUN Le, SUN Zhen, DANG Zhiyuan, DENG Xiuquan

2023, 33(S1):  174-179.  doi:10.16265/j.cnki.issn1003-3033.2023.S1.0980

Asbtract ( 152 )   HTML ( 4)   PDF (2397KB) ( 220 )  

Figures and Tables | References | Related Articles | Metrics

In order to study the characteristics of emergencies along high-speed railways and put forward corresponding prevention and control countermeasures, the analogy analysis method, case analysis method, and classification analysis method were used to study the typical emergencies along the high-speed railways in China and abroad. The fishbone diagram analysis method was used to study three kinds of typical illegal construction emergencies along high-speed railways. The causes of emergencies along high-speed railways were summarized, including natural factors, foreign invasion, human factors, and animal factors, and the cause analysis chart and root cause analysis table of illegal construction along high-speed railways were obtained by fishbone diagram. The results show that the emergencies along the high-speed railway have the characteristics of abruptness, multi-factor coupling, repetition, sociality, and difficulty in prevention. In combination with the above characteristics, the safety of high-speed railway operations should be guaranteed from three aspects: strengthening safety publicity and education, strengthening technology research, development, and application, and coordinating road and local planning.

Investigation into risk assessment of bolt corrosion failure in deep mines

WU Saisai, ZHANG Zengrui, JIN Tao, ZHANG Xin, GUO Jinping

2023, 33(S1):  180-184.  doi:10.16265/j.cnki.issn1003-3033.2023.S1.0374

Asbtract ( 122 )   HTML ( 2)   PDF (1695KB) ( 100 )  

Figures and Tables | References | Related Articles | Metrics

In order to solve the bolt corrosion failure in underground mines, a mathematical model based on predicting the bolt corrosion failure rate was proposed. By collecting the relevant data of mine corrosion failure bolts, the principal component analysis (PCA) method and gradient boosting tree (GTB) method were used to extract useful information from the original data. Combined with the SVM model, the corrosion failure probability of bolts in complex mine environments was predicted, and the model was tested by using datasets with continuous features and spatial data. The impact weight of various environmental factors on corrosion failure was analyzed and compared with SVM and GTB-SVM models. The research results indicate that feature transformation based on PCA is a reliable risk prediction method. The PCA-SVM model performs superior in terms of prediction accuracy and robustness of results, with AUC values reaching 0.84 in the training set and 0.83 in the test set. This model will serve as a useful online tool to support the security and digitization of process systems. The PCA-SVM model proposed in the article can accurately predict the corrosion failure probability of bolts.

Study on spreading characteristics and fire extinguishing efficiency of water mist based on UAV-borne fire extinguishing bombs

LI Cong, JIN Yanke, XU Wenbo, LI Chengwu, ZOU Biao

2023, 33(S1):  185-191.  doi:10.16265/j.cnki.issn1003-3033.2023.S1.4006

Asbtract ( 167 )   HTML ( 6)   PDF (5317KB) ( 279 )  

Figures and Tables | References | Related Articles | Metrics

In order to verify the feasibility and efficiency of UAV-borne fire extinguishing bombs for extinguishing fire, the structure of UAV-borne fire extinguishing bombs was designed and optimized. The extinguishing fire process of the fire extinguishing bombs was formulated; field tests and full-scale tests of fire extinguishing by UAV-borne fire extinguishing bombs were developed; a high-definition camera was used to record the entire process, including UAV-borne fire extinguishing bomb release, burst, spreading of water mist, and fire extinguishing action; statistical analysis was performed on various parameters, such as spreading area and real burst height, and the influence of different technical parameters on the fire extinguishing efficiency of the fire extinguishing bombs was studied. The results show that: the error in release height of the fire extinguishing bombs is less than 3.5 m, and the error in burst height is less than 2 m; the dispersion intensity distribution of water mist shows a decreasing trend from the center; the spreading area of water mist is positively correlated with the release height but negatively correlated with burst height; the preset technical parameters are a release height of 35 m and a burst height of 8-10 m to achieve the best fire extinguishing efficiency.

Detection algorithm of slime water overflow based on convolutional neural network

ZHANG Qi, JIRGEL

2023, 33(S1):  192-195.  doi:10.16265/j.cnki.issn1003-3033.2023.S1.5004

Asbtract ( 127 )   HTML ( 3)   PDF (2070KB) ( 73 )  

Figures and Tables | References | Related Articles | Metrics

In order to solve the problem of slime water overflow in the factory, a solution of real-time monitoring of slime water overflow was put forward. First, CNN was used to extract features from the slime water monitoring images, and then the extracted features were sent into the model for training. The accuracy rate was continuously improved through fine tuning. Finally, relevant evaluation indicators were used to evaluate the performance of the model. The results show that compared with the traditional detection algorithm, the slime water overflow detection model based on the CNN has an improvement of 15% in terms of evaluation indicators. Accurate judgment can also be made on the severity of slime water overflow, and all evaluation indicators exceed 90%, which is helpful to reduce the occurrence of slime water overflow.

Study on combustion mechanism of micron-sized aluminum powder in hydrogen/water vapor atmosphere

ZHANG Shulin, YAN Xiang, LONG Ruiji, LU Yi, SHI Shiliang

2023, 33(S1):  196-202.  doi:10.16265/j.cnki.issn1003-3033.2023.S1.2479

Asbtract ( 182 )   HTML ( 6)   PDF (3030KB) ( 140 )  

Figures and Tables | References | Related Articles | Metrics

In order to study the explosion risk of the gas-powder two-phase system contained in the production and processing of aluminum products, the combustion mechanism of aluminum powder in humid environments was revealed. The microscopic reaction process of micron-sized aluminum powder in a hydrogen/water vapor atmosphere was simulated based on Chemkin software. According to the gas phase combustion mechanism of aluminum powder, a kinetic model of a chemical reaction containing 28 components (Al, O, AlO, AlO₂, AlH, etc.,) and 68-step elementary reactions was constructed. By varying the mole ratio of water vapor to air, the effects of water vapor content on the sensitivity of combustion temperature, as well as the mole fraction and maximum rate of production of key free radicals were analyzed. The results show that according to the temperature sensitivity analysis, the increase in water vapor content will reduce the combustion temperature of micron-sized aluminum powder when reaching equilibrium. Specifically, the key elementary reaction R32 (Al + H₂O = AlOH + H), which affects the combustion temperature at equilibrium, changes from promoting the temperature rise at the beginning and then suppressing the temperature rise to completely suppressing the temperature rise. According to the analysis of the rate of production, the increase in water vapor content reduces the mole fraction of O and AlO free radicals when reaching equilibrium. According to the reaction path analysis, the key reaction path of micron-sized aluminum powder during combustion in a hydrogen/water vapor atmosphere is obtained, among which Al→O, Al→AlO, Al₂O₂→AlO, and other elementary reactions are strong.

Study on energy change of gas-containing coal during triaxial compression under low pressure

MENG Wei, GAO Xia, ZHANG Baoyong, WU Qiang

2023, 33(S1):  203-208.  doi:10.16265/j.cnki.issn1003-3033.2023.S1.1942

Asbtract ( 103 )   HTML ( 2)   PDF (3244KB) ( 90 )  

Figures and Tables | References | Related Articles | Metrics

To explore the energy characteristics of coal under pressure and the law of energy change of critical destruction point, based on the stress-strain curve of gas-containing coal during conventional triaxial compression, the law of elastic strain energy and dissipation energy change with strain in the process of gas-containing coal destruction was studied. The energy explanation for the deformation of gas-containing coal under different moisture contents and different pressures was given. The results show that the effective energy ratio increases first and then decreases with the increasing moisture content under the same pressure, indicating that the increase in moisture content decreases the strength of coal samples. A multi-linear regression equation of the total energy coupling relationship between the critical destruction point during the triaxial compression deformation of gas-containing coal and pressure and moisture content was established, with a better fitting effect.

Research on early warning technology of surge fault of micro-turbojet engine

MA Haoyi, CAI Jing, YANG Tiance

2023, 33(S1):  209-214.  doi:10.16265/j.cnki.issn1003-3033.2023.S1.4004

Asbtract ( 145 )   HTML ( 3)   PDF (2922KB) ( 157 )  

Figures and Tables | References | Related Articles | Metrics

In order to effectively warn of the compressor surge fault of an MTE, the relevant engine parameters corresponding to the surge fault were determined by fault injection in the engine simulation model. Sensors corresponding to the monitoring parameters were installed in the MTE bench test, and data were collected and transmitted through the acquisition card. Multiple test runs were conducted. Then six characteristic speed points were selected in the speed range of 0-140 000 r/min, and the simulation model and MTE test run data were combined to calculate the fault threshold of the parameters at the characteristic speed points. Finally, an early warning program for the surge fault based on LabVIEW was designed, and the feasibility of the early warning program was verified by designing a surge fault test on the MTE test bench. The results show that the two parameters most affected by the compressor surge fault are the outlet pressure of the compressor and the outlet temperature of the combustion chamber. When MTE surges, the outlet pressure of the compressor drops, and the outlet temperature of the combustion chamber rises sharply. The early warning program can not only monitor the parameter changes in real time and issue an alarm but also stop the engine in time to ensure the safety of the test personnel.

Appearance design of LHDs based on lattice topology optimization method and EWM

WANG Zhenyu, XIANG Zerui, ZOU Rui, DING Tiecheng, ZHI Jinyi

2023, 33(S1):  215-221.  doi:10.16265/j.cnki.issn1003-3033.2023.S1.2537

Asbtract ( 117 )   HTML ( 0)   PDF (4465KB) ( 232 )  

Figures and Tables | References | Related Articles | Metrics

To facilitate the innovative design of large-scale mining machinery, the external characteristics of LHDs were summarized. Additionally, a lattice topology optimization method and EWM were proposed for designing and evaluating the appearance of LHDs. The lattice topology optimization method was used to refine the appearance of the LHD. Subsequently, the analytic hierarchy process-EWM (AHP-EWM) was employed to assign weights to the evaluation indicators and construct the hierarchical criterion model. Five indicators, namely creativity, aesthetics, functionality, economic viability, and technical ability, were identified to constitute the evaluation system. The AHP was used to assign subjective weights to first-level indicators, and the objective weights of second-level indicators were analyzed by EWM. According to python, the weights of five methods, namely grey relational degree, multi-attribute decision analysis weight (CRITIC), independence weight, fuzzy comprehensive evaluation method, approximate ideal solution sorting method, and ideal point method (TOPSIS), were calculated. The feasibility of the AHP-EWM method was demonstrated. Finally, alternative designs were optimized based on the indicator weights and their corresponding scores, and the least squares support vector machine (LSSVM) was used to validate the model. The results show that the LSSVM model achieves a coefficient of determination above 0.93 and a mean square error below 0.01 in regression analysis. It outperforms traditional models with higher accuracy, confirming the effectiveness of the optimization decision model combining the lattice topology optimization method and EWM.

Public safety

Research on the construction of civil airport safety management system based on digital twin technology

SUN Diange

2023, 33(S1):  222-227.  doi:10.16265/j.cnki.issn1003-3033.2023.S1.0257

Asbtract ( 140 )   HTML ( 5)   PDF (4018KB) ( 212 )  

Figures and Tables | References | Related Articles | Metrics

In view of the characteristics of numerous civil airport safety operation departments, complex accident causes, diversity of safety risk sources, and the difficulties in improving the safety management level of existing civil airports with traditional technical methods, the feasibility of using digital twin technology to build a civil airport safety management system was analysed, and gives the design framework. The research results indicate that the use of digital twin technology can achieve spatial annotation and display of civil airport safety management information, facilitating the entry, inspection, query, and monitoring of safety information such as hazards and equipment facilities; During emergency rescue, the digital twin model, combined with accident rescue plans and expert systems, can bring greater convenience to airports in simulating emergency rescue training and emergency command and dispatch work.

Prediction model for demand for subway security inspectors under public health emergencies

LI Delong, CHENG Yu, LI Youdong

2023, 33(S1):  228-234.  doi:10.16265/j.cnki.issn1003-3033.2023.S1.0084

Asbtract ( 123 )   HTML ( 1)   PDF (1792KB) ( 130 )  

Figures and Tables | References | Related Articles | Metrics

In order to accurately predict the demand for temporary subway security inspectors during public health emergencies, a prediction model for the demand for temporary subway security inspectors during public health emergencies was proposed from the perspective of graded response to emergencies. The model was based on fatigue prediction and virus susceptibility models. In addition, the Beijing Jishuitan subway station was taken as an example. The results show that the original subway security inspectors are significantly insufficient in responding to public health emergencies, and it is thus difficult to efficiently prevent and control public health emergencies; in terms of predicting the demand for security inspectors, the demand for temporary security inspectors has significantly decreased when calculated based on cumulative fatigue scores, but there is a risk of insufficient emergency response capacity; the demand for temporary security inspectors is high when calculated based on working hours, but the daily cumulative fatigue score of security inspectors is low and ensures the ability to efficiently respond to emergencies.

Research on urban emergencies based on butterfly catastrophe theory

YANG Chao

2023, 33(S1):  235-242.  doi:10.16265/j.cnki.issn1003-3033.2023.S1.0091

Asbtract ( 116 )   HTML ( 1)   PDF (2910KB) ( 167 )  

Figures and Tables | References | Related Articles | Metrics

In order to prevent the occurrence of urban emergencies, the butterfly mutation theory was used to analyze the occurrence process of various urban emergencies, a mechanism model for the occurrence process of urban emergencies was constructed, and the main reasons for the occurrence of urban emergencies were analyzed. Then, a prevention model for urban emergencies was constructed, and preventive measures for urban emergencies were proposed from the government, units, individuals, and legal levels. The results show that the mechanism model of the occurrence process can reveal the entire process of urban emergencies. The occurrence of urban emergencies is composed of four processes: initial factor changes, continuous initial factor changes, system state transition, and urban emergencies. Based on the occurrence process, the main causes of urban emergencies can be analyzed. The prevention model provides scientific and effective ways and theoretical support for preventing the occurrence of urban emergencies.

Anti-icing retrofit design of PSS system of LEAP-1A engine

YANG Tiance, WU Chaokang, CAI Jing, WANG Siyuan, YANG Dacheng

2023, 33(S1):  243-248.  doi:10.16265/j.cnki.issn1003-3033.2023.S1.4005

Asbtract ( 190 )   HTML ( 1)   PDF (2801KB) ( 212 )  

Figures and Tables | References | Related Articles | Metrics

In order to prevent possible errors in the pressure-sensing element signals caused by water vapor condensation inside the PSS of the LEAP-1A engine, which will affect engine control and flight safety, an anti-icing retrofit study of the PSS was conducted by simulation. By establishing the finite element model of the PSS and combining the real flight data, the icing conditions inside the casing under different operating conditions were explored. Failure modes and severity caused by system icing were analyzed, and failure warning modes for the PSS were studied. On this basis, the anti-icing retrofit scheme of the PSS was designed, and the anti-icing simulation and verification methods were proposed. The test results were used to verify the criterion. The results show that the retrofit scheme based on pressure manifold differential pressure-controlled heating will effectively avoid the failure caused by icing in the PSS, and the value of pressure difference provides a criterion for prototype tests.

Research on assessment system of urban community safety development

WU Zhenzhen, YANG Wentao, WANG Xi, REN Xia

2023, 33(S1):  249-255.  doi:10.16265/j.cnki.issn1003-3033.2023.S1.2549

Asbtract ( 153 )   HTML ( 0)   PDF (1625KB) ( 169 )  

Figures and Tables | References | Related Articles | Metrics

In order to ensure high-quality urban development, standardized construction of community safety management was carried out. The current safety risks faced by urban communities and the countermeasures were systematically analyzed, and the key tasks of safety supervision were considered. The assessment system of community safety development was proposed based on 19 elements from six aspects of organizational guarantee, risk prevention and control, monitoring and early warning, emergency management, safety culture, and continuous improvement. The assessment conditions of the elements were explained, and the weight coefficients were determined through the analytic hierarchy process. In addition, a rating evaluation model and evaluation criteria were established. On this basis, a community in Liangxi District, Wuxi City, Jiangsu Province was taken as an example for assessing community safety development. The results show that the assessment system can be used to guide the actual work of community safety development, and it can reflect the actual situation of community safety development in a more prepared and objective way. The shortcomings of community safety development can be identified, and targeted improvements can be made.

Crowd monitoring and analysis technology for large-scale events based on multi-source data fusion

YAN Song, ZHANG Yi, WANG Zezhong, HAN Shaocong, LI Linfeng

2023, 33(S1):  256-262.  doi:10.16265/j.cnki.issn1003-3033.2023.S1.2545

Asbtract ( 257 )   HTML ( 8)   PDF (2829KB) ( 255 )  

Figures and Tables | References | Related Articles | Metrics

Relying on only a single data source for trajectory analysis has problems such as insufficient accuracy, insufficient coverage, and limited functionality in multiple scenes when large-scale events are held. In view of the application of multi-source heterogeneous data fusion in crowd monitoring and analysis of large-scale events, system design and key technologies were studied in this paper. At the system design level, the overall framework of multi-source heterogeneous data fusion was proposed, and the crowd monitoring and analysis system scheme was designed. At the key technology level, according to the sparsity and diversity of signaling data, a technical scheme of signaling data processing based on pyramid matching was proposed. Due to the difficulties of cross-scene video fusion analysis, a technical scheme of human behavior recognition based on deep learning and spatio-temporal correlation was given. In view of the low accuracy of human trajectory analysis, a trajectory recovery and analysis technical scheme based on multi-source data fusion of signaling, video, and ticket was provided. The application of the technology in the 2022 Beijing Winter Olympics and Winter Paralympics shows that the monitoring accuracy of the crowd flow direction distribution is more than 90%, and the positioning accuracy is less than 100 m, which realizes the accurate perception and prediction of the crowd trajectory.

Research on safety sign classification based on CNN

WANG Yaohan, SONG Zeyang, ZHANG Lidong

2023, 33(S1):  263-269.  doi:10.16265/j.cnki.issn1003-3033.2023.S1.0070

Asbtract ( 123 )   HTML ( 2)   PDF (6859KB) ( 54 )  

Figures and Tables | References | Related Articles | Metrics

In order to solve the problems of lack of safety sign data sets, special safety sign graphics, and complex backgrounds, CNN was used to extract the characteristics of safety signs. Based on the VGG-16 network structure and CNN, a VGG16-17 model that could identify 17 kinds of safety signs was constructed. There were 816 original data, and 4 708 images were obtained by expanding the data set through data augmentation. The data set was divided into a training set and a validation set according to the ratio of 4∶1. By adjusting some parameters in the model, the influence of epoch times and batch size on the recognition and classification effect of the model was analyzed. The results show that when the epoch is 20, and the batch size is 32, the model results are the best, and the recognition accuracy is 97.92%. Compared with the improved model based on the data set with no data augmentation, the accuracy is increased by 19.39%. Meanwhile, compared with the traditional VGG16 model, the recognition accuracy of the improved model is improved by 4.3%. This demonstrates that model improvement and data augmentation contribute to the improvement of image recognition.

Emergency technology and management

Study on ability of airport emergency commanders under emergency drills

WANG Lei, DING Keyuan, LI Mingyu

2023, 33(S1):  270-276.  doi:10.16265/j.cnki.issn1003-3033.2023.S1.0071

Asbtract ( 144 )   HTML ( 1)   PDF (2225KB) ( 160 )  

Figures and Tables | References | Related Articles | Metrics

In order to enhance the ability of emergency commanders and improve the efficiency of airport emergency responses, the ability of airport emergency commanders in the context of emergency drills was studied. By refining the main tasks and corresponding capabilities of each stage of the drill, the summary table of capability elements of airport emergency commanders was established, which was composed of four levels including process control, management skills, knowledge acquisition and application, and personality traits and 17 elements. The expert scoring method was applied to score the influence relationship between the elements, and then the DEMATEL method was combined with the ISM method to identify the key elements that affected emergency commanders under emergency drills and analyze the logical relationship between the elements in the system. The results show that process control is the core of airport emergency drills; communication and situation analysis capabilities are the core capabilities of commanders; resource overall planning and management supervision capabilities in the management skill dimension are more important; personality trait level requires emergency commanders to have better organizational and coordination capabilities, and emergency practical experience is the most important in the knowledge and experience dimension.